Electronics Manufacturing Technical Articles

Papers and articles related to SMT, PCB & EMS industry.

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1907 SMT / PCB Assembly Related Technical Articles

How to Manage Material Outgassing in Reflow Oven

Nov 24, 2020 | Gerjan Diepstraten

In a lead-free reflow process, temperatures are higher, and materials use outgasses more than in a leaded reflow process. The trends toward higher density populated boards and more pin-in-paste technology also increase solder paste use. More components and more solder paste result in more outgassing of chemistry during the reflow process. Some assemblies report condensation of vapors when the cold printed circuit board enters the oven. Little is known about the interaction between these condensed materials in terms of the interaction between these condensed materials and the reliability of the assembly. Apart from the question of reliability, a printed circuit board contaminated with a small film of residues after reflow soldering is not desirable....

Publisher: Vitronics Soltec

Vitronics Soltec

Global manufacturer of XPM Reflow Ovens, ZEVA Selective Soldering and Delta Wave Soldering Equipment.

Camdenton, Missouri, USA

Manufacturer

The Risk And Solution For No-Clean Flux Not Fully Dried Under Component Terminations the Risk And Solution For No-Clean Flux Not Fully Dried Under Component Terminations

Nov 24, 2020 | Fen Chen and Ning Cheng Lee, Ph.D.

The miniaturization trend is driving industry to adopting low standoff components or components in cavity. The cost reduction pressure is pushing telecommunication industry to combine assembly of components and electromagnetic shield in one single reflow process. As a result, the flux outgassing/drying is getting very difficult for devices due to poor venting channel. This resulted in insufficiently dried/burnt-off flux residue. For a properly formulated flux, the remaining flux activity posed no issue in a dried flux residue for no-clean process. However, when venting channel is blocked, not only solvents remain, but also activators could not be burnt off. The presence of solvents allows mobility of active ingredients and the associated corrosion, thus poses a major threat to the reliability. In this work, a new halogen-free no-clean SnAgCu solder paste, 33-76-1, has been developed. This solder paste exhibited SIR value above the IPC spec 100 MΩ without any dendrite formation, even with a wet flux residue on the comb pattern. The wet flux residue was caused by covering the comb pattern with 10 mm × 10 mm glass slide during reflow and SIR testing in order to mimic the poorly vented low standoff components. The paste 33-76-1 also showed very good SMT assembly performance, including voiding of QFN and HIP resistance. The wetting ability of paste 33-76-1 was very good under nitrogen. For air reflow, 33-76-1 still matched paste C which is widely accepted by industry for air reflow process. The above good performance on both non-corrosivity with wet flux residue and robust SMT process can only be accomplished through a breakthrough in flux technology....

Publisher: Indium Corporation

Indium Corporation

Solder pastes, solder preforms, solder spheres, soldering fluxes, electrically-conductive adhesives. All alloys: tin-lead, lead-free, indium alloys, and more.

Utica, New York, USA

Manufacturer

What is an analog signature analyzer and how does it work?

Nov 19, 2020 | Irina Slobodyanyuk

Simultaneously with the first complex electronic circuits, the task of creating effective means of diagnosing and repairing them appeared. In previous decades, specialized programmable stands were used for diagnostics of serial electronic products, as well as various testers and probes for troubleshooting during their operation. But the dramatic increase in the density / cost factor, in parallel with the very rapid modification of electronic products, made programmable stands economically ineffective even in mass production. The use of traditional laboratory equipment (oscilloscopes, multimeters, etc.) requires power supply to the defective modules, which is often impossible and unsafe, since it can lead to failure of the working modules of the module. In addition, the use of this equipment requires documentation and highly qualified personnel. More automated and sophisticated signature analysis systems came to the rescue in solving this problem. A feature of these devices is that they allow you to test digital and analog assemblies without dismantling components and without supplying voltage....

Publisher: Engineering Physics Center of MSU

Engineering Physics Center of MSU

We're engaged in the development and sale of complex electronics, automation of experimental installations in laser physics, creation of automatic testing systems and diagnostics of printed circuit boards and electronic components

Moscow, Russia

Manufacturer

Troubleshooting the STM32F429 board and restoring its operation

Nov 19, 2020 | Igor Degtyarev

How to repair boards if they have been produced for a long time, and the documentation is lost? In this case, intelligent recognition systems can help, which will allow you to identify component pins without documentation for the board. In this article, we will find the STM32F429 board malfunctions without any documentation and in the least amount of time....

Publisher: Engineering Physics Center of MSU

Engineering Physics Center of MSU

Moscow, Russia

Manufacturer

Designing a High Performance Electroless Nickel and Immersion Gold to Maximize Highest Reliability

Nov 15, 2020 | Robert Spreemann, Rick Nichols, Sandra Nelle

The latest highest reliability requirements demand a high performance electroless nickel and immersion gold (HP ENIG). The new IPC specification 4552A has refocused the industry with reference to nickel corrosion. The interpretation of the existing specification, that judges corrosion on 3 levels, is complex and if misinterpreted can lead to phantom failures. An obvious way to avoid any potential misinterpretation is to eradicate any evidence of corrosion completely....

Publisher: Atotech

Atotech

One of the world's leading suppliers of integrated production systems, chemistry, equipment, know-how and service for electroplating, semiconductor and printed circuit board manufacturing.

Berlin, Germany

Manufacturer

Comparing Soldering Results of ENIG and EPIG Post Steam Exposure

Nov 15, 2020 | J. Bengston and R. DePoto Uyemura International

ENIG, electroless nickel immersion gold is now a well-regarded finish used to enhance and preserve the solder-ability of copper circuits. EPIG, electroless palladium immersion gold, is a new surface finish also for enhancing and preserving solder-ability but with the advantage of eliminating Electroless Nickel from the deposit layer. This feature has become increasingly important with the increasing use of high frequeny PWB designs whereby nickel's magnetic properties are detrimental. We examine these two finishes and their respective soldering characteristics as plated and after steam aging and offer an explanation for the performance deviation....

Publisher: Uyemura International Corporation

Uyemura International Corporation

Ontario, , California, USA

Printed Electronics for Medical Devices

Nov 10, 2020 | Jeff Grover

As is the case with many other markets where faster, highly capable technologies have resulted in more intelligent processes and products, the medical device sector is also undergoing a "smart" transformation. This has driven the development of medical devices that provide greater access to in-home care and monitoring and faster results for medical professionals, with the overarching benefit of better patient outcomes. Devices applied to the human body that commonly sense...

Publisher: Henkel Electronic Materials

Henkel Electronic Materials

Henkel is a manufacturer of materials for PCB and component assembly. The materials include Loctite adhesives, Multicore soldering products, Hysol encaps and underfills, and Power Devices thermal phase change pads.

Irvine, California, USA

Manufacturer

Reliability Challenges in Fabrication of Flexible Hybrid Electronics for Human Performance Monitors: A System Level Study

Nov 10, 2020 | Varun Soman, Student Member, IEEE, Yasser Khan, Madina Zabran, Mark Schadt, Member, IEEE, Paul Hart, Member, IEEE, Michael Shay, Member, IEEE, Frank Egitto, Member, IEEE, Konstantinos Papathomas, Member, IEEE, Natasha A. D. Yamamoto, Donggeon Han, Ana C.

Flexible hybrid electronics (FHE) interface rigid electronic components with flexible sensors, circuits, and substrates. This paper reports the reliability improvement of a FHE Human Performance Monitor (HPM), designed to monitor electrocardiography (ECG) signals....

Publisher: Stanford University

Stanford University

Life. Energy. Environment. This triad of engineering priorities is perhaps unmatched in its potential for improving the quality of life for all inhabitants of planet Earth. And at the heart of all three is chemical engineering.

Stanford, California, USA

Research Institute / Laboratory / School

Ball Grid Array (BGA) Voiding Affecting Functionality

Nov 09, 2020 | ACI Technologies, Inc.

A customer contacted ACI Technologies regarding a high failure rate of their assemblies. They provided assemblies to be X-rayed and inspected for the purpose of identifying any process related issues such as (but not limited to) solder and assembly workmanship and evidence of damage due to moisture related problems during reflow (a.k.a. "popcorning"). Moisture damage usually appears as physical damage to the component. The first indication of moisture damage would be externally observable changes to the package in the form of bulging or fractures to the outer surface of the component, an example of which is shown in Figure 1. Internally observable indicators of moisture damage typically include fractures to the die inside the package and lifted or fractured wire bonds. These conditions would be apparent during transmissive X-ray inspection. Another symptom of moisture related damage would be inconsistent solder joint sizes that result from package deformation during the liquidus phase of the reflow process. None of these indicators of moisture related damage were present on the customer samples....

Publisher: ACI Technologies, Inc.

ACI Technologies, Inc.

ACI, an authorized IPC Training Center operating the National Electronics Manufacturing Center of Excellence providing analytical testing, manufacturing and repair services to the electronics industry.

Philadelphia, Pennsylvania, USA

Consultant / Service Provider, Standards Setting / Certification, Training Provider

WHY CLEAN A NO-CLEAN FLUX

Nov 04, 2020 | Mike Bixenman, DBA [Kyzen Corporation] Mark McMeen, [STI Corporation] Bruno Tolla, Ph.D. [Kester Corporation]

Residues present on circuit boards can cause leakage currents if not controlled and monitored. How "Clean is Clean" is neither easy nor cheap to determine. Most OEMs use analytical methods to assess the risk of harmful residues. The levels that can be associated with clean or dirty are typically determined based on the exposed environment where the part will be deployed. What is acceptably clean for one segment of the industry may be unacceptable for more demanding segments. As circuit assemblies increase in density, understanding cleanliness data becomes more challenging. The risk of premature failure or improper function is typically site specific. The problem is that most do not know how to measure or define cleanliness nor can they recognize process problems related to residues. A new site specific method has been designed to run performance qualifications on boards built with specific soldering materials, reflow settings and cleaning methods. High impedance measurements are performed on break off coupons designed with components geometries used to build the assembly. The test method provides a gauge of potential contamination sources coming from the assembly process that can contribute to electrochemical migration....

Publisher: KYZEN Corporation

KYZEN Corporation

A leading supplier of precision cleaning chemistries to the worldwide electronics, metal finishing, medical, semiconductor, and optical industries.

Nashville, Tennessee, USA

Manufacturer

Higher Defluxing Temperature and Low Standoff Component Cleaning - A Connection?

Nov 04, 2020 | Jigar Patel and Umut Tosun

OEMs and CMs designing and building electronic assemblies for high reliability applications are typically faced with a decision to clean or not to clean the assembly. If ionic residues remain on the substrate surface, potential failure mechanisms, including dendritic growth by electrochemical migration reaction and leakage current, may result. These failures have been well documented. If a decision to clean substrates is made, there are numerous cleaning process options available. For defluxing applications, the most common systems are spray-in-air, employing either batch or inline cleaning equipment and an engineered aqueous based cleaning agent. Regardless of the type of cleaning process adopted, effective cleaning of post solder residue requires chemical, thermal and mechanical energies. The chemical energy is derived from the engineered cleaning agent; the thermal energy from the increased temperature of the cleaning agent, and the mechanical energy from the pump system employed within the cleaning equipment. The pump system, which includes spray pressure, spray bar configuration and nozzle selection, is optimized for the specific process to create an efficient cleaning system. As board density has increased and component standoff heights have decreased, cleaning processes are steadily challenged. Over time, cleaning agent formulations have advanced to match new solder paste developments, spray system configurations have improved, and wash temperatures (thermal energy) have been limited to a maximum of 160ºF. In most cases, this is due to thermal limitations of the materials used to build the polymer-based cleaning equipment. Building equipment out of stainless steel is an option, but one that may be cost prohibitive. Given the maximum allowable wash temperature, difficult cleaning applications are met by increasing the wash exposure time; including reducing the conveyor speed of inline cleaners or extending wash time in batch cleaners. Although this yields effective cleaning results, process productivity may be compromised. However, high temperature resistant polymer materials, capable of withstanding a 180°F wash temperature, are now available and can be used in cleaning equipment builds. For this study, the authors explored the potential for increasing cleaning process efficiency as a result of an increase in thermal energy due to the use of higher wash temperature. The cleaning equipment selected was an inline cleaner built with high temperature resistant polymer material. For the analysis, standard substrates were used. These were populated with numerous low standoff chip cap components and soldered with both no-clean tin-lead and lead-free solder pastes. Two aqueous based cleaning agents were selected, and multiple wash temperatures and wash exposure times were evaluated. Cleanliness assessments were made through visual analysis of under-component inspection, as well as localized extraction and Ion Chromatography in accordance with current IPC standards....

Publisher: ZESTRON Americas

ZESTRON Americas

The globally leading provider of high precision cleaning products, services and training solutions in the electronics and semiconductor manufacturing industries.

Manassas, Virginia, USA

Consultant / Service Provider, Manufacturer, Training Provider

Orbotech Trion 2340 Manual

Oct 30, 2020 | Aneryn

Preview of the Complete Aneryn's Orbotech Trion 2340 Manual. It explains how to programme the AOI machine, how to train new components (shapes), how to connect it to your network, among other processes. Following the Guide, you will minimize false alarms and escapes rates easily. Full Manual available at <a href="https://aneryn.com/creation/trion-2340-manual/">https://aneryn.com/creation/trion-2340-manual/</a> <a href="https://sinfoniadigital.es/en/web-design-seo-barcelona/">Digital development by Sinfonía Digital</a>...

Publisher: Aneryn

Aneryn

We provide custom software for industry. We develop engineering projects as well. Our electronic, control and mechanical engineers are at your service. Based in Barcelona.

Terrassa, Spain

Consultant / Service Provider, Manufacturer

Solder Joint Reliability of Pb-free Sn-Ag-Cu Ball Grid Array (BGA) Components in Sn-Pb Assembly Process

Oct 27, 2020 | Robert Kinyanjui, Ph.D., Quyen Chu, Polina Snugovsky, Ph.D., Richard Coyle, Ph.D.

For companies that choose to take the Pb-free exemption under the European Union's RoHS Directive and continue to manufacture tin-lead (Sn-Pb) electronic products, there is a growing concern about the lack of Sn-Pb ball grid array (BGA) components. Many companies are compelled to use the Pb-free Sn-Ag-Cu (SAC) BGA components in a Sn-Pb process, for which the assembly process and solder joint reliability have not yet been fully characterized. A careful experimental investigation was undertaken to evaluate the reliability of solder joints of SAC BGA components formed using Sn-Pb solder paste. This evaluation specifically looked at the impact of package size, solder ball volume, printed circuit board (PCB) surface finish, time above liquidus and peak temperature on reliability. Four different BGA package sizes (ranging from 8 to 45 mm2) were selected with ball-to-ball pitch size ranging from 0.5mm to 1.27mm. Two different PCB finishes were used: electroless nickel immersion gold (ENIG) and organic solderability preservative (OSP) on copper. Four different profiles were developed with the maximum peak temperatures of 210oC and 215oC and time above liquidus ranging from 60 to 120 seconds using Sn-Pb paste. One profile was generated for a lead-free control. A total of 60 boards were assembled. Some of the boards were subjected to an as assembled analysis while others were subjected to an accelerated thermal cycling (ATC) test in the temperature range of -40oC to 125oC for a maximum of 3500 cycles in accordance with IPC 9701A standard. Weibull plots were created and failure analysis performed. Analysis of as-assembled solder joints revealed that for a time above liquidus of 120 seconds and below, the degree of mixing between the BGA SAC ball alloy and the Sn-Pb solder paste was less than 100 percent for packages with a ball pitch of 0.8mm or greater. Depending on package size, the peak reflow temperature was observed to have a significant impact on the solder joint microstructural homogeneity. The influence of reflow process parameters on solder joint reliability was clearly manifested in the Weibull plots. This paper provides a discussion of the impact of various profiles' characteristics on the extent of mixing between SAC and Sn-Pb solder alloys and the associated thermal cyclic fatigue performance....

Publisher: Sanmina-SCI

Sanmina-SCI

Sanmina-SCI is a tier 1 provider of EMS and PWB along with vertically integrated capabilities from design through qualification.

San Jose, California, USA

Manufacturer

Size Matters - The Effects of Solder Powder Size on Solder Paste Performance

Oct 27, 2020 | Tony Lentz

Solder powder size is a popular topic in the electronics industry due to the continuing trend of miniaturization of electronics. The question commonly asked is "when should we switch from Type 3 to a smaller solder powder?" Solder powder size is usually chosen based on the printing requirements for the solder paste. It is common practice to use IPC Type 4 or 5 solder powders for stencil designs that include area ratios below the recommended IPC limit of 0.66. The effects of solder powder size on printability of solder paste have been well documented. The size of the solder powder affects the performance of the solder paste in other ways. Shelf life, stencil life, reflow performance, voiding behavior, and reactivity / stability are all affected by solder powder size. Testing was conducted to measure each of these solder paste performance attributes for IPC Type 3, Type 4, Type 5 and Type 6 SAC305 solder powders in both water soluble and no clean solder pastes. The performance data for each size of solder powder in each solder paste flux was quantified and summarized. Guidance for choosing the optimal size of solder powder is given based on the results of this study....

Publisher: FCT ASSEMBLY, INC.

FCT ASSEMBLY, INC.

With numerous facilities in the United States, we are one of the electronics industry's leading manufacturers of lead-free solder products, superior quality stencils, and precision cut parts.

Greeley, Colorado, USA

Manufacturer

Interconnect Reliability Correlation with System Design and Transportation Stress

Oct 18, 2020 | Dr. Paul Wang, Vincent Weng, and Dr. Kim Sang Chim

Interconnect reliability especially in BGA solder joints and compliant pins are subjected to design parameters which are very critical to ensure product performance at pre-defined shipping condition and user environment. Plating thickness of compliant pin and damping mechanism of electronic system design are key successful factors for this purpose. In additional transportation and material handling process of a computer server system will be affected by shock under certain conditions. Many accessories devices in the server computer system tend to become loose resulting in poor contact or solder intermittent interconnect problems due to the shock load from the transportation and material handling processes....

Publisher: MiTAC International Corporation

MiTAC International Corporation

MiTAC Holdings Group has been developing into a multinational organization of JDM / ODM / OEM / OPM (Original Product Manufacture), design and R&D, manufacturing, testing, assembling, marketing, and servicing in around four decade

Taoyuan City, Taiwan

Manufacturer

Realization of a New Concept for Power Chip Embedding

Oct 18, 2020 | H. Stahr, M. Morianz, I. Salkovic

Embedded components technology has launched its implementation in volume products demanding high levels of miniaturization. Small modules with embedded dies and passive components on the top side are mounted in hand held devices. Smartphones have been the enablers for this new technology using the capabilities of embedded components. With this technological background another business field became interesting for embedded components – the embedded power electronics. The roadmap of the automotive industry shows a clear demand for miniaturized power electronic applications. Drivers are the regulations for the international fleet emissions which are focusing on three major trends....

Publisher: AT & S Austria Technologie & Systemtechnik Aktiengesellschaft

AT & S Austria Technologie & Systemtechnik Aktiengesellschaft

Mission: First choice for advanced applications Mission: We set the highest quality standards in our industry. We industrialize leading-edge technology. We care about people. We reduce our ecological footprint. We create value.

Leoben, Austria

Manufacturer

Effect of Morphology of Calcium Carbonate on Toughness Behavior and Thermal Stability of Epoxy-Based Composites

Oct 14, 2020 | Guijun Yang, Young-Jung Heo and Soo-Jin Park

In this study, the modification of an epoxy matrix with different amounts of cube-like and rod-like CaCO3 nanoparticles was investigated. The effects of variations in the morphology of CaCO3 on the mechanical properties and thermal stability of the CaCO3/epoxy composites were studied. The rod-like CaCO3/epoxy composites (EP-rod) showed a higher degradation temperature (4.5 _C) than neat epoxy. The results showed that the mechanical properties, such as the flexural strength, flexural modulus, and fracture toughness of the epoxy composites with CaCO3 were enhanced by the addition of cube-like and rod-like CaCO3 nanoparticles. Moreover, the mechanical properties of the composites were enhanced by increasing the amount of CaCO3 added but decreased when the filler content reached 2%. The fracture toughness Kic and fracture energy release rate Gic of cube-like and rod-like CaCO3/epoxy composites (0.85/0.74 MPa m1/2 and 318.7/229.5 J m...

Publisher: Inha University

Inha University

Development of Character, Search for the Truth, and Service to Society Founded in 1954 to fulfill the dearest wish of empowering and bringing prosperity to the nation, Inha University stands for the Ideals of building students'

Incheon, South Korea

Research Institute / Laboratory / School

ADVANCED BORON NITRIDE EPOXY FORMULATIONS EXCEL IN THERMAL MANAGEMENT APPLICATIONS

Oct 14, 2020 | Michael J. Hodgin and Richard H. Estes

Epoxy based adhesives are prevalent interface materials for all levels of electronic packaging. One reason for their widespread success is their ability to accept fillers. Fillers allow the adhesive formulator to tailor the electrical and thermal properties of a given epoxy. Silver flake allow the adhesive to be both electrically conductive and thermally conductive. For potting applications, heat sinking, and general encapsulation where high electrical isolation is required, aluminum oxide has been the filler of choice. Today, advanced Boron Nitride filled epoxies challenge alternative thermal interface materials like silicones, greases, tapes, or pads. The paper discusses key attributes for designing and formulating advanced thermally conductive epoxies. Comparisons to other common fillers used in packaging are made. The filler size, shape and distribution, as well as concentration in the resin, will determine the adhesive viscosity and rheology. Correlation's between Thermal Resistance calculations and adhesive viscosity are made. Examples are shown that determination of thermal conductivity values in "bulk" form, do not translate into actual package thermal resistance. Four commercially available thermally conductive adhesives were obtained for the study. Adhesives were screened by shear strength measurements, Thermal Cycling ( -55 °C to 125 °C ) Resistance, and damp heat ( 85 °C / 85 %RH ) resistance. The results indicate that low modulus Boron Nitride filled epoxies are superior in formulation and design. Careful selection of stress relief agents, filler morphology, and concentration levels are critical choices the skilled formulator must make. The advantages and limitations of each are discussed and demonstrated....

Publisher: Epoxy Technology, Inc.

Epoxy Technology, Inc.

Epoxy Technology, Inc., founded in 1966, is a pioneer in the development and manufacture of Specialty Epoxy, UV & UV Hybrid adhesives to meet key performance standards needed in high-tech applications.

Billerica, Massachusetts, USA

Manufacturer

FRACTURE TOUGHNESS OF THERMALLY CONDUCTIVE ADHESIVES

Oct 14, 2020 | John Timmerman, Maria Salamon

Thermally conductive adhesives provide many advantages over traditional mechanical fastening techniques. Specifically, they use less material and space and are more amenable to automation than existing solutions. The thermal and mechanical properties of these materials are well understood but little work has been done to characterize and understand their toughness and fracture behavior. This paper presents the effects of filler loading as well as matrix composition on the fracture toughness of thermally conductive silicone adhesives. It was observed that the fracture toughness of these materials increased significantly with initial filler loading, and that the mechanical properties and fracture toughness depended on the molecular architecture of the matrix used....

Publisher: Henkel Electronic Materials

Henkel Electronic Materials

Irvine, California, USA

Manufacturer

Keep Your Business Going Even In the Lockdown Through A CRM Solution

Oct 08, 2020 | Anchal Solanki

You are afraid of losing your business during this global COVID-19 crisis. But now, you got a ray of light to bring back your firm on track without breaking the bank. You must be thinking that how CRM software can provide you the juices that you require to sustain your business....

Publisher: FinCRM Technologies

FinCRM Technologies

FinCRM holds expertise in providing Customer Relationship Management (CRM) software and Full Stack Office Management solutions.

Pune, India

Consultant / Service Provider

Optimized Stress Testing for Flexible Hybrid Electronics Designs

Oct 08, 2020 | Hang Gao, Ganapati Bhat, Umit Y. Ogras, and Sule Ozev

Flexible hybrid electronics (FHE) is emerging as a promising solution to combine the benefits of printed electronics and silicon technology. FHE has many high-impact potential areas, such as wearable applications, health monitoring, and soft robotics, due to its physical advantages, which include light weight, low cost and the ability conform to different shapes. However, physical deformations in the field can lead to significant testing and validation challenges. For example, designers must ensure that FHE devices continue to meet their specs even when the components experience stress due to bending. Hence, physical deformation, which is hard to emulate, has to be part of the test procedures for FHE devices. This paper is the first to analyze stress experience at different parts of FHE devices under different bending conditions. We develop a novel methodology to maximize the test coverage with minimum number of text vectors with the help of a mixed integer linear programming formulation. We validate the proposed approach using an FHE prototype and COMSOL Multiphysics simulations...

Publisher: Arizona State University

Arizona State University

Continued strength Our faculty, students and staff have redoubled their collaborative efforts to strengthen, grow and broaden the programs in the School of Electrical, Computer and Energy Engineering. The school's continued streng

Tempe, Arizona, USA

Research Institute / Laboratory / School

Design and Integration of aWireless Stretchable Multimodal Sensor Network in a Composite Wing

Oct 08, 2020 | Xiyuan Chen, Loic Maxwell, Franklin Li , Amrita Kumar, Elliot Ransom, Tanay Topac, Sera Lee, Mohammad Faisal Haider , Sameh Dardona and Fu-Kuo Chang

This article presents the development of a stretchable sensor network with high signal-to-noise ratio and measurement accuracy for real-time distributed sensing and remote monitoring. The described sensor network was designed as an island-and-serpentine type network comprising a grid of sensor "islands" connected by interconnecting "serpentines." A novel high-yield manufacturing process was developed to fabricate networks on recyclable 4-inch wafers at a low cost. The resulting stretched sensor network has 17 distributed and functionalized sensing nodes with low tolerance and high resolution. The sensor network includes Piezoelectric (PZT), Strain Gauge(SG), and Resistive Temperature Detector (RTD) sensors. The design and development of a flexible frame with signal conditioning, data acquisition, and wireless data transmission electronics for the stretchable sensor network are also presented. The primary purpose of the frame subsystem is to convert sensor signals into meaningful data, which are displayed in real-time for an end-user to view and analyze. The challenges and demonstrated successes in developing this new system are demonstrated, including (a) developing separate signal conditioning circuitry and components for all three sensor types (b) enabling simultaneous sampling for PZT sensors for impact detection and (c)configuration of firmware/software for correct system operation. The network was expanded with an in-house developed automated stretch machine to expand it to cover the desired area. The released and stretched network was laminated into an aerospace composite wing with edge-mount electronics for signal conditioning, processing, power, and wireless communication....

Publisher: Stanford University

Stanford University

Stanford, California, USA

Research Institute / Laboratory / School

Silicone Thermally Conductive Grease: Improving Thermal Management of Electronic Assemblies

Sep 30, 2020 | Carlos Montemayor

Introduction •Market trend: Smaller, more efficient, more powerful, run faster •ICs and other sophisticated electronic components typically operate efficiently only under a certain range of temperatures •Operational temperatures must be kept within a suitable range • Excessive heat can damage performance and can even cause system failure...

Publisher: Dow Electronic Materials

Dow Electronic Materials

DEM develops and markets highly sophisticated materials used in the electronic materials segment of the global electronics value chain.

Marlborough, Massachusetts, USA

Manufacturer

High and Matched Refractive Index Liquid Adhesives for Optical Device Assembly

Sep 30, 2020 | Taro Kenmochi

There is an increase in the number of optical sensors and cameras being integrated into electronics devices. These go beyond cell phone cameras into automotive sensors, wearables, and other smart devices. The applications can be lens bonding, waveguide imprinting, or other applications where the adhesive is in the optical pathway. To support these various optical applications, new materials with tailorable optical properties are required. There is often a mismatched refractive index between plastic lenses such as PC (Poly Carbonate), COP (Cyclo Olefin Polymer), COC (Cyclo Olefin Copolymer), PMMA (Poly Methyl Methacrylate), and UV curable liquid adhesive. A UV curable liquid adhesive is needed where you can alter the refractive index from 1.470 to 1.730, and maintain high optical performance as yellowness index, haze, and transmittance. This wide range of refractive index possibilities provides optimized optical design. Using particular plastic lens must consider how chemical attack is occurring during the process. Another consideration is that before the UV curable liquid adhesive is cured, chemical raw component can attack the plastic lens which then cracks and delaminates. We will also show engineering and reliability data which defined root cause and provided how optical performance is maintained under different reliability conditions....

Publisher: Kyoritsu Chemical & Co., Ltd

Kyoritsu Chemical & Co., Ltd

Research, development, manufacturing and marketing of sophisticated chemical products developed by applying fine chemicals and nano-technologies in cutting-edge fields such as home information appliances, IT, semiconductors, batte

Tokyo, Japan

Manufacturer

Optimising Solder Paste Volume for Low Temperature Reflow of BGA Packages

Sep 23, 2020 | Keith Sweatman

The need to minimise thermal damage to components and laminates, to reduce warpage-induced defects to BGA packages, and to save energy, is driving the electronics industry towards lower process temperatures. For soldering processes the only way that temperatures can be substantially reduced is by using solders with lower melting points. Because of constraints of toxicity, cost and performance, the number of alloys that can be used for electronics assembly is limited and the best prospects appear to be those based around the eutectic in the Bi-Sn system, which has a melting point of about 139°C. Experience so far indicates that such Bi-Sn alloys do not have the mechanical properties and microstructural stability necessary to deliver the reliability required for the mounting of BGA packages. Options for improving mechanical properties with alloying additions that do not also push the process temperature back over 200°C are limited. An alternative approach that maintains a low process temperature is to form a hybrid joint with a conventional solder ball reflowed with a Bi-Sn alloy paste. During reflow there is mixing of the ball and paste alloys but it has been found that to achieve the best reliability a proportion of the ball alloy has to be retained in the joint, particular in the part of the joint that is subjected to maximum shear stress in service, which is usually the area near the component side. The challenge is then to find a reproducible method for controlling the fraction of the joint thickness that remains as the original solder ball alloy. Empirical evidence indicates that for a particular combination of ball and paste alloys and reflow temperature the extent to which the ball alloy is consumed by mixing with the paste alloy is dependent on the volume of paste deposited on the pad. If this promising method of achieving lower process temperatures is to be implemented in mass production without compromising reliability it would be necessary to have a method of ensuring the optimum proportion of ball alloy left in the joint after reflow can be consistently maintained. In this paper the author explains how the volume of low melting point alloy paste that delivers the optimum proportion of retained ball alloy for a particular reflow temperature can be determined by reference to the phase diagrams of the ball and paste alloys. The example presented is based on the equilibrium phase diagram of the binary Bi-Sn system but the method could be applied to any combination of ball and paste alloys for which at least a partial phase diagram is available or could be easily determined....

Publisher: Nihon Superior Co. Ltd

Nihon Superior Co. Ltd

Production and distribution of metal jointing materials for electronics (solder, flux, brazing alloys, etc) Sales of nonferrous metal Export-import business

Osaka, Japan

Manufacturer

Low Temperature SMT Solder Evaluation

Sep 23, 2020 | Howard "Rusty" Osgood, David Geiger, Robert Pennings, Christian Biederman, Jie Jiang, Jon Bernal

The electronics industry could benefit greatly from using a reliable, manufacturable, reduced temperature, SMT solder material (alloy-composition) which is cost competitive with traditional Sn3Ag0.5Cu (SAC305) solder. The many possible advantages and some disadvantages / challenges are discussed. Until recently, the use of Sn/Bi based materials has been investigated with negative consequences for high strain rate (drop-shock) applications and thus, these alloys have been avoided. Recent advances in alloy "doping" have opened the door to revisit Sn/Bi alloys as a possible alternative to SAC-305 for many applications. We tested the manufacturability and reliability of three low-temperature and one SAC-305 (used as a control) solder paste materials. Two of these materials are doped Sn/Bi/Ag and one is just Sn/Bi/Ag1%. We will discuss the tests and related results. And lastly, we will discuss the prospects, applications and possible implications (based on this evaluation) of these materials together with future actions....

Publisher: Flextronics International

Flextronics International

Flex Ltd. is an American Singaporean-domiciled multinational electronics contract manufacturer. It is the third-largest global electronics manufacturing services, original design manufacturer company by revenue, behind only ...

Milpitas, California, USA

Manufacturer

Approaches for additive manufacturing of 3D electronic applications

Sep 16, 2020 | Hoerber, J.; Glasschroeder, J.; Pfeffer, M.; Schilp, J.; Zaeh, M.; Franke, J.

Additive manufacturing processes typically used for mechanical parts can be combined with enhanced technologies for electronics production to enable a highly flexible manufacturing of personalized 3D electronic devices. To illustrate different approaches for implementing electrical and electronic functionality, conductive paths and electronic components were embedded in a powder bed printed substrate using an enhanced 3D printer. In addition, a modified Aerosol Jet printing process and assembly technologies adapted from the technology of Molded Interconnect Devices were applied to print circuit patterns and to electrically interconnect components on the surface of the 3D substrates....

Publisher: Institute for Factory Automation and Production Systems (FAPS)

Institute for Factory Automation and Production Systems (FAPS)

At the Technical Faculty (TF) of the Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) more than 20 engineering and computer science courses are offered. The TF has an excellent reputation in science and business.

Nuremberg, Germany

Research Institute / Laboratory / School

Additive manufacturing frontier: 3D printing electronics

Sep 16, 2020 | Bingheng Lu, Hongbo Lan and Hongzhong Liu

3D printing is disrupting the design and manufacture of electronic products. 3D printing electronics offers great potential to build complex object with multiple functionalities. Particularly, it has shown the unique ability to make embedded electronics, 3D structural electronics, conformal electronics, stretchable electronics, etc. 3D printing electronics has been considered as the next frontier in additive manufacturing and printed electronics. Over the past five years, a large number of studies and efforts regarding 3D printing electronics have been carried out by both academia and industries. In this paper, a comprehensive review of recent advances and significant achievements in 3D printing electronics is provided. Furthermore, the prospects, challenges and trends of 3D printing electronics are discussed. Finally, some promising solutions for producing electronics with 3D printing are presented....

Publisher: Xian Jiaotong University

Xian Jiaotong University

Xi'an Jiaotong University is a C9 League university with strengths in engineering, technology, management, and life sciences located in Xi'an, Shaanxi, China. It is a Chinese Ministry of Education Class A Double First Class Univ.

Xi'an, Shaanxi, China

Research Institute / Laboratory / School

New development of atomic layer deposition: processes, methods and applications

Sep 08, 2020 | Peter Ozaveshe Oviroh, Rokhsareh Akbarzadeh, Dongqing Pan, Rigardt Alfred Maarten Coetzee and Tien-Chien Jen

Atomic layer deposition (ALD) is an ultra-thin film deposition technique that has found many applications owing to its distinct abilities. They include uniform deposition of conformal films with controllable thickness, even on complex three-dimensional surfaces, and can improve the efficiency of electronic devices. This technology has attracted significant interest both for fundamental understanding how the new functional materials can be synthesized by ALD and for numerous practical applications, particularly in advanced nanopatterning for microelectronics, energy storage systems, desalinations, catalysis and medical fields. This review introduces the progress made in ALD, both for computational and experimental methodologies, and provides an outlook of this emerging technology in comparison with other film deposition methods. It discusses experimental approaches and factors that affect the deposition and presents simulation methods, such as molecular dynamics and computational fluid dynamics, which help determine and predict effective ways to optimize ALD processes, hence enabling the reduction in cost, energy waste and adverse environmental impacts. Specific examples are chosen to illustrate the progress in ALD processes and applications that showed a considerable impact on other technologies....

Publisher: University of Johannesburg

University of Johannesburg

The Faculty of Engineering and the Built Environment (FEBE) is one of the seven faculties in the University of Johannesburg. It offers both Engineering Technology and Engineering Science undergraduate and postgraduate programmes..

Johannesburg, South Africa

Research Institute / Laboratory / School

Semi-Additive Process (SAP) Utilizing Very Uniform Ultrathin Copper by A Novel Catalyst

Sep 02, 2020 | Steve Iketani, Mike Vinson

The demand for miniaturization and higher density electronic products has continued steadily for years, and this trend is expected to continue, according to various semiconductor technology and applications roadmaps. The printed circuit board (PCB) must support this trend as the central interconnection of the system. There are several options for fine line circuitry. A typical fine line circuit PCB product using copper foil technology, such as the modified semi-additive process (mSAP), uses a thin base copper layer made by pre-etching. The ultrathin copper foil process (SAP with ultrathin copper foil) is facing a technology limit for the miniaturization due to copper roughness and thickness control. The SAP process using sputtered copper is a solution, but the sputtering process is expensive and has issues with via plating. SAP using electroless copper deposition is another solution, but the process involved is challenged to achieve adequate adhesion and insulation between fine-pitch circuitries. A novel catalyst system--liquid metal ink (LMI)--has been developed that avoids these concerns and promotes a very controlled copper thickness over the substrate, targeting next generation high density interconnect (HDI) to wafer-level packaging substrates and enabling 5-micron level feature sizes. This novel catalyst has a unique feature, high density, and atomic-level deposition. Whereas conventional tin-palladium catalyst systems provide sporadic coverage over the substrate surface, the deposited catalyst covers the entire substrate surface. As a result, the catalyst enables improved uniformity of the copper deposition starting from the initial stage while providing higher adhesion and higher insulation resistance compared to the traditional catalysts used in SAP processes. This article discusses this new catalyst process, which both proposes a typical SAP process using the new catalyst and demonstrates the reliability improvements through a comparison between a new SAP PCB process and a conventional SAP PCB process....

Publisher: Averatek Corporation

Averatek Corporation

Averatek Corporation is a high tech company based in Santa Clara, CA that provides custom design services and patterned circuit board materials manufactured through the use of an innovative, proprietary process.

Santa Clara, California, USA

Manufacturer

Developments in Electroless Copper Processes to Improve Performance in amSAP Mobile Applications

Sep 02, 2020 | Stefanie Bremmert, Laurence Gregoriades, Kay Wurdinger, Thomas Vágó, Tobias Bernhard, Frank Bruning, Roger Massey

With the adoption of Wafer Level Packages (WLP) in the latest generation mobile handsets, the Printed Circuit Board (PCB) industry has also seen the initial steps of High Density Interconnect (HDI) products migrating away from the current subtractive processes towards a more technically adept technique, based on an advanced modified Semi Additive Process (amSAP). This pattern plate process enables line and space features in the region of 20um to be produced, in combination with fully filled, laser formed microvias. However, in order to achieve these process demands, a step change in the performance of the chemical processes used for metallization of the microvia is essential. In the electroless Copper process, the critical activator step often risks cross contamination by the preceding chemistries. Such events can lead to uncontrolled buildup of Palladium rich residues on the panel surface, which can subsequently inhibit etching and lead to short circuits between the final traces. In addition, with more demands being placed on the microvia, the need for a high uniformity Copper layer has become paramount, unfortunately, as microvia shape is often far from ideal, the deposition or "throw" characteristics of the Copper bath itself are also of critical importance. This "high throwing power" is influential elsewhere in the amSAP technique, as it leads to a thinner surface Copper layer, which aids the etching process and enables the ultra-fine features being demanded by today's high end PCB applications. This paper discusses the performance of an electroless Copper plating process that has been developed to satisfy the needs of challenging amSAP applications. Through the use of a radical predip chemistry, the formation, build up and deposition of uncontrolled Pd residues arising from activator contamination has been virtually eradicated. With the adoption of a high throwing power Copper bath, sub 30um features are enabled and microvia coverage is shown to be greatly improved, even in complex via shapes which would otherwise suffer from uneven coverage and risk premature failure in service. Through a mixture of development and production data, this paper aims to highlight the benefits and robust performance of the new electroless Copper process for amSAP applications...

Publisher: Atotech

Atotech

One of the world's leading suppliers of integrated production systems, chemistry, equipment, know-how and service for electroplating, semiconductor and printed circuit board manufacturing.

Berlin, Germany

Manufacturer

Reworking ALD Coatings

Sep 02, 2020 | ACI Technologies, Inc.

Atomic layer deposition (ALD) is a process of creating coatings on a molecular layer by layer basis. Using an iterated sequence of self-saturating deposition cycles that are self-terminating, a single layer can be deposited at a time, allowing for highly uniform films with complete conformality. The composition of the film typically used for coating printed wiring boards (PWBs) is a high alumina (Al2O3) sequential deposition of alumina and titania capped with a corrosion protective titanium aluminate layer, most notably ALD-Cap from Sundew Technologies, LLC. Rework is a process of restoring an electronics assembly to full functionality to prolong equipment life and reduce the amount of scrap. The process typically involves:...

Publisher: ACI Technologies, Inc.

ACI Technologies, Inc.

Philadelphia, Pennsylvania, USA

Consultant / Service Provider, Standards Setting / Certification, Training Provider

Approaches to Overcome Nodules and Scratches on Wire Bondable Plating on PCBs

Aug 27, 2020 | Young K. Song and Vanja Bukva and Ryan Wong

Initially adopted internal specifications for acceptance of printed circuit boards (PCBs) used for wire bonding was that there were no nodules or scratches allowed on the wirebond pads when inspected under 20X magnification. The nodules and scratches were not defined by measurable dimensions and were considered to be unacceptable if there was any sign of a visual blemish on wire-bondable features. Analysis of the yield at a PCB manufacturer monitored monthly for over two years indicated that the target yield could not be achieved, and the main reasons for yield loss were due to nodules and scratches on the wirebonding pads. The PCB manufacturer attempted to eliminate nodules and scratches. First, a light-scrubbing step was added after electroless copper plating to remove any co-deposited fine particles that acted as a seed for nodules at the time of copper plating. Then, the electrolytic copper plating tank was emptied, fully cleaned, and filtered to eliminate the possibility of co-deposited particles in the electroplating process. Both actions greatly reduced the density of the nodules but did not fully eliminate them. Even though there was only one nodule on any wire-bonding pad, the board was still considered a reject. To reduce scratches on wirebonding pads, the PCB manufacturer utilized foam trays after routing the boards so that they did not make direct contact with other boards. This action significantly reduced the scratches on wire-bonding pads, even though some isolated scratches still appeared from time to time, which caused the boards to be rejected. Even with these significant improvements, the target yield remained unachievable. Another approach was then taken to consider if wire bonding could be successfully performed over nodules and scratches and if there was a dimensional threshold where wire bonding could be successful. A gold ball bonding process called either stand-off-stitch bonding (SSB) or ball-stitch-on-ball bonding (BSOB) was used to determine the effects of nodules and scratches on wire bonds. The dimension of nodules, including height, and the size of scratches, including width, were measured before wire bonding. Wire bonding was then performed directly on various sizes of nodules and scratches on the bonding pad, and the evaluation of wire bonds was conducted using wire pull tests before and after reliability testing. Based on the results of the wire-bonding evaluation, the internal specification for nodules and scratches for wirebondable PCBs was modified to allow nodules and scratches with a certain height and a width limitation compared to initially adopted internal specifications of no nodules and no scratches. Such an approach resulted in improved yield at the PCB manufacturer....

Publisher: Teledyne DALSA

Teledyne DALSA

Established in 1980 and acquired by Teledyne Technologies in 2011, Teledyne DALSA designs, develops, manufactures, and markets digital imaging products and solutions, in addition to providing semiconductor products and services.

Waterloo, Ontario, Canada

Other

An Automatic Surface Defect Inspection System for Automobiles Using Machine Vision Methods

Aug 27, 2020 | Qinbang Zhou , Renwen Chen, Bin Huang, Chuan Liu, Jie Yu and Xiaoqing Yu

Automobile surface defects like scratches or dents occur during the process of manufacturing and cross-border transportation. This will affect consumers' first impression and the service life of the car itself. In most worldwide automobile industries, the inspection process is mainly performed by human vision, which is unstable and insufficient. The combination of artificial intelligence and the automobile industry shows promise nowadays. However, it is a challenge to inspect such defects in a computer system because of imbalanced illumination, specular highlight reflection, various reflection modes and limited defect features. This paper presents the design and implementation of a novel automatic inspection system (AIS) for automobile surface defects which are the located in or close to style lines, edges and handles. The system consists of image acquisition and image processing devices, operating in a closed environment and noncontact way with four LED light sources. Specifically, we use five plane-array Charge Coupled Device (CCD) cameras to collect images of the five sides of the automobile synchronously. Then the AIS extracts candidate defect regions from the vehicle body image by a multi-scale Hessian matrix fusion method. Finally, candidate defect regions are classified into pseudo-defects, dents and scratches by feature extraction (shape, size, statistics and divergence features) and a support vector machine algorithm. Experimental results demonstrate that automatic inspection system can effectively reduce false detection of pseudo-defects produced by image noise and achieve accuracies of 95.6% in dent defects and 97.1% in scratch defects, which is suitable for customs inspection of imported vehicles....

Publisher: Nanjing University

Nanjing University

Located in the ancient capital of Nanjing, Nanjing University and its predecessors have taken responsibility for the country and the nation during its development of over 100 years. Committed to the prosperity of the nation ...

Nanjing, Jiangsu, China

Research Institute / Laboratory / School

All-in-One, Wireless, Stretchable Hybrid Electronics for Smart, Connected, and Ambulatory Physiological Monitoring

Aug 19, 2020 | Yun-Soung Kim, Musa Mahmood, Yongkuk Lee, Nam Kyun Kim, Shinjae Kwon, Robert Herbert, Donghyun Kim, Hee Cheol Cho,* and Woon-Hong Yeo*

Commercially available health monitors rely on rigid electronic housing coupled with aggressive adhesives and conductive gels, causing discomfort and inducing skin damage. Also, research-level skin-wearable devices, while excelling in some aspects, fall short as concept-only presentations due to the fundamental challenges of active wireless communication and integration as a single device platform. Here, an all-in-one, wireless, stretchable hybrid electronics with key capabilities for real-time physiological monitoring, automatic detection of signal abnormality via deep-learning, and a long-range wireless connectivity (up to 15 m) is introduced. The strategic integration of thin-film electronic layers with hyperelastic elastomers allows the overall device to adhere and deform naturally with the human body while maintaining the functionalities of the on-board electronics. The stretchable electrodes with optimized structures for intimate skin contact are capable of generating clinical-grade electrocardiograms and accurate analysis of heart and respiratory rates while the motion sensor assesses physical activities. Implementation of convolutional neural networks for real-time physiological classifications demonstrates the feasibility of multifaceted analysis with a high clinical relevance. Finally, in vivo demonstrations with animals and human subjects in various scenarios reveal the versatility of the device as both a health monitor and a viable research tool....

Publisher: Georgia Institute of Technology

Georgia Institute of Technology

Center for Board Assembly Research CBAR- advanced research on board assembly processes and systems

Atlanta, Georgia, USA

Research Institute / Laboratory / School

An Engineer's Guide to Testing and Evaluating The Performance of Desiccant Bags for the Protection of Critical Moisture Sensitive Devices

Aug 16, 2020 | Dan Jenkins

Not all desiccant bags are created or perform equally. Performance measures include: a) How long does desiccant last? b) How much are can be desiccated in a given area? c) How much moisture is retained, and or released back into the atmosphere? This article walks engineers through various test they can perform to determine efficacy. Additionally, the article highlight between adsorption vs adsorption....

Publisher: Steel Camel

Steel Camel

Super powerful expanding desiccant to keep boards & microelectronics moisture free.... Much different than Silica Sand Beads. Also supplier of corrosion prevention treatments that are alternatives to Conformal coatings.

Tampa, Florida, USA

Other

Best Practices in Selecting Coatings and Pottings for Solar Panel Systems; Junction Boxes and Inverters

Aug 13, 2020 | Greg Caswell [DfR], Matt Perry [H.B. Fuller], Haichuan Zhao [H.B. Fuller], Ralph Velazquez [H.B. Fuller]

The solar industry has driven solutions that result in electronics systems that are required to perform in outside environments for over 25 years. This industry expectation has resulted in solutions to protect the electronics from failure that can result from interaction with moisture, and various chemicals leading to corrosion and shorting of the systems. Potting and encapsulation compounds can impart the very high level of protection from environmental, thermal, chemical, mechanical, and electrical conditions that the solar applications demand....

Publisher: DfR Solutions (acquired by ANSYS Inc)

DfR Solutions (acquired by ANSYS Inc)

DfR Solutions has world-renowned expertise in applying the science of Reliability Physics to electrical and electronics technologies, and is a leading provider of quality, reliability, and durability (QRD) research and consulting

College Park,

Consultant / Service Provider

Additive Manufacturing for Next Generation Microwave Electronics and Antennas

Aug 13, 2020 | Xuanke He, Bijan K. Tehrani, Ryan A. Bahr, Manos Tentzeris

The paper will discuss the integration of 3D printing and inkjet printing fabrication technologies for microwave and millimeter-wave applications. With the recent advancements in 3D and inkjet printing technology, achieving resolution down to 50 um, it is feasible to fabricate electronic components and antennas operating in the millimeter-wave regime. The nature of additive manufacturing allows designers to create custom components and devices for specialized applications and provides an excellent and inexpensive way of prototyping electronic designs. The combination of multiple printable materials enables the vertical integration of conductive, dielectric, and semi-conductive materials which are the fundamental components of passive and active circuit elements such as inductors, capacitors, diodes, and transistors. Also, the on-demand manner of printing can eliminate the use of subtractive fabrication processes, which are necessary for conventional microfabrication processes such as photolithography, and drastically reduce the cost and material waste of fabrication....

Publisher: Georgia Institute of Technology

Georgia Institute of Technology

Center for Board Assembly Research CBAR- advanced research on board assembly processes and systems

Atlanta, Georgia, USA

Research Institute / Laboratory / School

Selection of PCB Materials for 5G

Aug 05, 2020 | John Coonrod

With the first 5G NR standard recently approved by the 3GPP at the end of 2017, many companies are racing to design 5G radio products that will demand wider bandwidths, higher frequencies, enhanced carrier aggregation and support of massive MIMO. AT&T and Samsung plan to launch 5G mobile services and Verizon plans to launch 5G Fixed Wireless Access in the US this year while South Korea will be demonstrating 5G at the upcoming Winter Olympics....

Publisher: Rogers Corporation

Rogers Corporation

Rogers' high performance laminates and bondplies are engineered to meet stringent customer requirements for 5G wireless communication, wired infrastructure, automotive radar sensors, aerospace, satellites and more.

Chandler, Arizona, USA

Manufacturer

ALD of Alumina Ceramic Films for Hermetic Protection

Aug 05, 2020 | ACI Technologies, Inc.

A primary issue in electronics reliability for military applications is the ability to ensure long term operability in harsh, extreme environments. This requires more rigid standards, such as the MIL-STD-883 (Department of Defense Test Method Standard for Microcircuits), which commercial grade electronics typically do not satisfy. A solution commonly employed is to package the critical electronic components in hermetically sealed metal or ceramic enclosures which are costly and labor intensive. Not only are the components more expensive, but the assembly process is more difficult to automate, resulting in a substantial cost premium for military grade electronics....

Publisher: ACI Technologies, Inc.

ACI Technologies, Inc.

Philadelphia, Pennsylvania, USA

Consultant / Service Provider, Standards Setting / Certification, Training Provider

Aluminum Soldering - Product Guide

Jul 29, 2020 | Superior Flux and Mfg. Co.

Aluminum is a metal that it is hard to solder due to the high surface tension difference between it and molten solder alloy. This occurs because aluminum rapidly forms a tenacious oxide layer whenever it is exposed to oxygen in the air. The oxide layer is responsible for the high surface tension difference between the aluminum and the solder and impedes the solder from spreading evenly on an aluminum surface. There are hundreds of aluminum alloys available in the marketplace; it is important to identify the form of aluminum that is being soldered. Once this is done, an appropriate soldering technique can be chosen for soldering the specific aluminum alloy under consideration. Direct aluminum soldering eliminates using expensive plating techniques to prepare the aluminum surface for soldering....

Publisher: Superior Flux & Mfg. Co.

Superior Flux & Mfg. Co.

Manufactures environmentally friendly fluxes.

Cleveland, OH,

Manufacturer

Surface Treatment Enabling Low Temperature Soldering to Aluminum

Jul 29, 2020 | Divyakant Kadiwala

The majority of flexible circuits are made by patterning copper metal that is laminated to a flexible substrate, which is usually polyimide film of varying thickness. An increasingly popular method to meet the need for lower cost circuitry is the use of aluminum on Polyester (Al-PET) substrates. This material is gaining popularity and has found wide use in RFID tags, low cost LED lighting and other single-layer circuits. However, both aluminum and PET have their own constraints and require special processing to make finished circuits. Aluminum is not easy to solder components to at low temperatures and PET cannot withstand high temperatures. Soldering to these materials requires either an additional surface treatment or the use of conductive epoxy to attach components. Surface treatment of aluminum includes the likes of Electroless Nickel Immersion Gold plating (ENIG), which is extensive wet-chemistry and cost-prohibitive for mass adoption. Conductive adhesives, including Anisotropic Conductive Paste (ACP), are another alternate to soldering components. These result in component substrate interfaces that are inferior to conventional solders in terms of performance and reliability. An advanced surface treatment technology will be presented that addresses all these constraints. Once applied on Aluminum surfaces using conventional printing techniques such as screen, stencil, etc., it is cured thermally in a convection oven at low temperatures. This surface treatment is non-conductive. To attach a component, a solder bump on the component or solder printed on the treated pad is needed before placing the component. The Aluminum circuit will pass through a reflow oven, as is commonly done in PCB manufacturing. This allows for the formation of a true metal to metal bond between the solder and the aluminum on the pads. This process paves the way for large scale, low cost manufacturing of Al-PET circuits. We will also discuss details of the process used to make functional aluminum circuits, study the resultant solder-aluminum bond, shear results and SEM/ EDS analysis....

Publisher: Averatek Corporation

Averatek Corporation

Santa Clara, California, USA

Manufacturer

Impact of Assembly Cycles on Copper Wrap Plating

Jul 22, 2020 | Hardeep Heer, Ryan Wong, et al

The PWB industry needs to complete reliability testing in order to define the minimum copper wrap plating thickness requirement for confirming the reliability of PTH structures. Predicting reliability must ensure that the failure mechanism is demonstrated as a wear-out failure mode because a plating wrap failure is unpredictable. The purpose of this study was to quantify the effects of various copper wrap plating thicknesses through IST testing followed by micro sectioning to determine the failure mechanism and identify the minimum copper wrap thickness required for a reliable PWB. Minimum copper wrap plating thickness has become an even a bigger concern since designers started designing HDI products with buried vias, microvias and through filled vias all in one design. PWBs go through multiple plating cycles requiring planarization after each plating cycle to keep the surface copper to a manageable thickness for etching. The companies started a project to study the relationship between Copper wrap plating thickness and via reliability. The project had two phases. This paper will present findings from both Phase 1 and Phase 2....

Publisher: Firan Technology Group

Firan Technology Group

FTG is a leading North American manufacturer of high technology printed circuit boards and precision illuminated display systems.

Toronto, Ontario, Canada

Consultant / Service Provider, Manufacturer

Soft, Wireless Periocular Wearable Electronics For Real-Time Detection Of Eye Vergence In A Virtual Reality Toward Mobile Eye Therapies

Jul 22, 2020 | Saswat Mishra et al

Recent advancements in electronic packaging and image processing techniques have opened the possibility for optics-based portable eye tracking approaches, but technical and safety hurdles limit safe implementation toward wearable applications. Here, we introduce a fully wearable, wireless soft electronic system that offers a portable, highly sensitive tracking of eye movements (vergence) via the combination of skin-conformal sensors and a virtual reality system. Advancement of material processing and printing technologies based on aerosol jet printing enables reliable manufacturing of skin-like sensors, while the flexible hybrid circuit based on elastomer and chip integration allows comfortable integration with a user's head. Analytical and computational study of a data classification algorithm provides a highly accurate tool for real-time detection and classification of ocular motions. In vivo demonstration with 14 human subjects captures the potential of the wearable electronics as a portable therapy system, whose minimized form factor facilitates seamless interplay with traditional wearable hardware....

Publisher: Georgia Institute of Technology

Georgia Institute of Technology

Center for Board Assembly Research CBAR- advanced research on board assembly processes and systems

Atlanta, Georgia, USA

Research Institute / Laboratory / School

Via Filling Applications in Practice

Jul 15, 2020 | Stefan Keller

Via Filling • Through Hole Vias - IPC-4761 – Plugging – Filling – Filled & Capped • MicroviaFilling and Stacked Vias...

Publisher: Würth Elektronik GmbH & Co. KG

Würth Elektronik GmbH & Co. KG

We produce circuit boards from your specifications in various designs.

Niedernhall, Germany

Consultant / Service Provider, Manufacturer

Via In Pad - Conductive Fill or Non-Conductive Fill?

Jul 15, 2020 | Tech Talk for Techies

In the early 2000s the first fine-pitch ball grid array devices became popular with designers looking to pack as much horsepower into as small a space as possible. "Smaller is better" became the rule and with that the mechanical drilling world became severely impacted by available drill bit sizes, aspect ratios, and plating methodologies. First of all, the diameter of the drill needed to be in the 0.006" or smaller range due to the reduction of pad size and spacing pitch. Secondly, the aspect ratio (depth to diameter) became limited by drill flute length, positional accuracy, rigidity of the tools (to prevent breakage), and the throwing power of acid copper plating systems. And lastly, the plating needed to close up the hole as much as possible, which led to problems with voiding, incomplete fill, and gas/solution entrapment....

Publisher: Advanced Circuits

Advanced Circuits

One-Stop Solution for PCB & Prototype Assembly Expanded PCB manufacturing capabilities to support advanced designs with demanding requirements including laser-drilled microvias, cavity boards, heavy copper up to 20 oz., via-in-pad

Aurora, Colorado, USA

Manufacturer

Creating Reusable Manufacturing Tests for High-Speed I/O with Synthetic Instruments

Jul 08, 2020 | Louis Y. Ungar, Neil G. Jacobson, T.M. Mak

There is a compelling need for functional testing of high-speed input/output signals on circuit boards ranging from 1 gigabit per second (Gbps) to several hundred Gbps. While manufacturing tests such as Automatic Optical Inspection (AOI) and In-Circuit Test (ICT) are useful in identifying catastrophic defects, most high-speed signals require more scrutiny for failure modes that arise due to high-speed conditions, such as jitter. Functional ATE is seldom fast enough to measure high-speed signals and interpret results automatically. Additionally, to measure these adverse effects it is necessary to have the tester connections very close to the unit under test (UUT) as lead wires connecting the instruments can distort the signal. The solution we describe here involves the use of a field programmable gate array (FPGA) to implement the test instrument called a synthetic instrument (SI). SIs can be designed using VHDL or Verilog descriptions and "synthesized" into an FPGA. A variety of general-purpose instruments, such as signal generators, voltmeters, waveform analyzers can thus be synthesized, but the FPGA approach need not be limited to instruments with traditional instrument equivalents. Rather, more complex and peculiar test functions that pertain to high-speed I/O applications, such as bit error rate tests, SerDes tests, even USB 3.0 (running at 5 Gbps) protocol tests can be programmed and synthesized within an FPGA. By using specific-purpose test mechanisms for high-speed I/O the test engineer can reduce test development time. The synthetic instruments as well as the tests themselves can find applications in several UUTs. In some cases, the same test can be reused without any alteration. For example, a USB 3.0 bus is ubiquitous, and a test aimed at fault detection and diagnoses can be used as part of the test of any UUT that uses this bus. Additionally, parts of the test set may be reused for testing another high-speed I/O. It is reasonable to utilize some of the test routines used in a USB 3.0 test, in the development of a USB 3.1 (running at 10 Gbps), even if the latter has substantial differences in protocol. Many of the SI developed for one protocol can be reused as is, while other SIs may need to undergo modifications before reuse. The modifications will likely take less time and effort than starting from scratch. This paper illustrates an example of high-speed I/O testing, generalizes failure modes that are likely to occur in high-speed I/O, and offers a strategy for testing them with SIs within FPGAs. This strategy offers several advantages besides reusability, including tester proximity to the UUT, test modularization, standardization approaching an ATE-agnostic test development process, overcoming physical limitations of general-purpose test instruments, and utilization of specific-purpose test instruments. Additionally, test instrument obsolescence can be overcome by upgrading to ever-faster and larger FPGAs without losing any previously developed design effort. With SIs and tests scalable and upward compatible, the test engineer need not start test development for high-speed I/O from scratch, which will substantially reduce time and effort....

Publisher: A.T.E. Solutions, Inc.

A.T.E. Solutions, Inc.

The leading Test, ATE and Testability consulting and educational firm, offering various test related courses. Maintains the BestTest Directory, a test community knowledge base. Publishes The BestTest eNewsletter.

Los Angeles, California, USA

Consultant / Service Provider, Manufacturer, Training Provider

Using Rheology Measurement As A Potentially Predictive Tool For Solder Paste Transfer Efficiency And Print Volume Consistency

Jul 02, 2020 | Mitch Holtzer, Karen Tellefsen and Westin Bent

Industry standards such as J-STD-005 and JIS Z 3284-1994 call for the use of viscosity measurement(s) as a quality assurance test method for solder paste. Almost all solder paste produced and sold use a viscosity range at a single shear rate as part of the pass-fail criteria for shipment and customer acceptance respectively. As had been reported many times, an estimated 80% of the defects associated with the surface mount technology process involve defects created during the printing process. Viscosity at a single shear rate could predict a fatal flaw in the printability of a solder paste sample. However, false positive single shear rate viscosity readings are not unknown....

Publisher: Alpha Assembly Solutions

Alpha Assembly Solutions

Alpha Assembly Solutions is a world leader in the development, manufacturing, and sales of innovative materials used in the assembly electronics, industrial joining and Photo Voltaic market places.

South Plainfield, New Jersey, USA

Manufacturer

101 EMI Shielding Tips and Tricks

Jul 02, 2020 | Holland Shielding Systems BV

Principle of shielding 1 The principle of shielding is creating a conductive layer completely surrounding the object you want to shield. This was invented by Michael Faraday and this system is known as a Faraday Cage. 2 Ideally, the shielding layer will be made up of conductive sheets or layers of metal that are connected by means of welding or soldering, without any interruptions. The shielding is perfect when there is no difference in conductivity between the used materials. When dealing with frequencies below 30 MHz, the metal thickness affects shielding effectiveness. We also offer a range of shielding methods for plastic enclosures. A complete absence of interruptions is not a realistic goal since the Faraday cage will have to be opened from time to time so electronics, equipment or people can be moved in or out. Openings are also needed for displays, ventilation, cooling, power supply, signals etc. 3 Shielding works in both directions, items inside the shielded room are shielded from outside influences. (Fig. 3.1)...

Publisher: Holland Shielding Systems BV

Holland Shielding Systems BV

Worldwide leading manufacturer of EMC (electromagnetic compatibility), EMI (electromagnetic interference), RFI (radio frequency interference), & EMP (electromagnetic pulse) shielding solutions. Our EMC experts will work ...

Dordrecht, Netherlands

Other

A PROCEDURE TO DETERMINE HEAD-IN-PILLOW DEFECT AND ANALYSIS OF CONTRIBUTING FACTORS

Jul 02, 2020 | Ranjit Pandher, Rahul Raut, Michael Liberatore, Navendra Jodhan, and Karen Tellefsen

Head-in-Pillow (HIP) defects are a growing concern in the electronics industry. These defects are usually believed to be the result of several factors, individually or in combination. Some of the major contributing factors include: surface quality of the BGA spheres, activity of the paste flux, improper placement / misalignment of the components, a non-optimal reflow profile, and warpage of the components. To understand the role of each of these factors in producing head-in-pillow defects and to find ways to mitigate them, we have developed two in-house tests....

Publisher: Cookson Electronics

Cookson Electronics

Leading materials science company that provides high performance materials, chemistry and technology solutions to the electronics and surface finishing industries worldwide.

Lakeville, Minnesota, USA

Manufacturer

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