Electronics Manufacturing Technical Articles

Reliability of Embedded Planar Capacitors under Temperature and Voltage Stress

May 21, 2015 | Mohammed A. Alam, Michael H. Azarian, Michael Osterman and Michael Pecht

In this work the reliability of an embedded planar capacitor laminate under temperature and voltage stress is investigated. The capacitor laminate consisted of an epoxy-BaTiO3 composite sandwiched between two layers of copper. The test vehicle with the embedded capacitors was subjected to a temperature of 125oC and a voltage bias of 200 V for 1000 hours. Capacitance, dissipation factor, and insulation resistance were monitored in-situ. Failed capacitors exhibited a sharp drop in insulation resistance, indicating avalanche breakdown. The decrease in the capacitance after 1000 hours was no more than 8% for any of the devices monitored. The decrease in the capacitance was attributed to delamination in the embedded capacitor laminate and an increase in the spacing between the copper layers....

Publisher: CALCE Center for Advanced Life Cycle Engineering

Reliability of Stacked Microvia

May 14, 2015 | Hardeep Heer, Ryan Wong

The Printed Circuit Board industry has seen a steady reduction in pitch from 1.0mm to 0.4mm; a segment of the industry is even using or considering a 0.25mm pitch. This has increased the use of stacked microvias in these designs. The process of stacking microvias has been practiced for several years in handheld devices; however, the devices generally do not operate in harsh conditions. Type 1 and Type 2 microvias have been tested over the years and have been found to be very reliable. We do not have enough test data for 3 and 4 stack microvias when placed on and off buried via. The main objective of this study was to understand the reliability of 3 and 4 stack microvias placed on and off a buried via....

Publisher: Firan Technology Group

The Long-term Shaping of the JTAG/Boundary-scan Standards

May 11, 2015 | Peter van den Eijnden, MD JTAG Technologies.

Originating from the last millenium, almost three decades ago, the introduction of surface mount packaging triggered a wave of changes throughout many aspects of electronics production. A small number of talented, innovative test engineers from various big players of the industry started to attend meetings to discuss the impact of that change of technology on their future test concepts for modern assemblies. The Joint Test Action Group was born....

Publisher: JTAG Technologies B. V.

Signal Transmission Loss due to Copper Surface Roughness in High-Frequency Region

Apr 30, 2015 | Elaine Liew, Mitsui Copper Foil Malaysia, Shah Alam Malaysia Taka-aki Okubo, Toshio Sudo, Shibaura Institute of Technology, Tokyo Japan Toshihiro Hosoi, Hiroaki Tsuyoshi, Fujio Kuwako, Mitsui Kinzoku Co., Ltd, Japan.

Higher-speed signal transmission is increasingly required on a printed circuit board to handle massive data in electronic systems. So, signal transmission loss of copper wiring on a printed circuit board has been studied. First, total signal loss was divided into dielectric loss and conductor loss quantitatively based on electromagnetic theory. In particular, the scattering loss due to surface roughness of copper foil has been examined in detail. And the usefulness of the copper foil with low surface roughness has been demonstrated....

Publisher: Mitsui Kinzoku Group

True Height Measurement in Solder Paste Inspection

Apr 29, 2015 | Dr. Subodh Kulkarni

SPI equipment is routinely used in Printed Circuit Board (PCB) manufacturing to monitor and control one of the most crucial steps affecting the finished quality of circuit board. Solder paste deposition is the key process in board assembly operations using SMT techniques. Our LSM™ system was the industry's first popular method of manually inspecting solder paste; our SE systems revolutionized SMT production by offering an automated method for performing in-process 3D inspection on the assembly line. SPI systems measure the height and volume of the solder pads before the components are applied and the solder melted, and when used properly, can reduce the incidence of solder-related defects to statistically insignificant amounts. Critical to the SPI measurement is the accuracy of the height measurement because that has a direct correlation with solder volume and defects....

Publisher: CyberOptics Corporation

Advanced modelling technique achieves near to zero set up time and minimal tuning

Apr 29, 2015 | Sean Langbridge

Statistical Appearance Modelling technology enables an AOI system to “learn real world variation” based on operator interaction with inspection task results. This provides an accurate statistical description of normal variation in a product. With modelling technology, the user does not have to anticipate potential defects as the system will “flag” anything outside the “normal production range”. And, since the system is programmed with real production variation, it is sensitive to small subtle changes enabling reliable defect detection. Autonomous prediction of process variation enables an AOI system to be set up from a single PCB with production-ready performance. Setup time can be < 15 minutes from data input to first PCB inspection making it an ideal solution for NPI and first-off verification....

Publisher: CyberOptics Corporation

Rework Challenges for Smart Phones and Tablets

Apr 23, 2015 | Paul Wood Advanced Product Applications Manager APR/ BGA Products OK International / Metcal.

Smart phones are complex, costly devices and therefore need to be reworked correctly the first time. In order to meet the ever-growing demand for performance, the complexity of mobile devices has increased immensely, with more than a 70% greater number of packages now found inside of them than just a few years ago. For instance, 1080P HD camera and video capabilities are now available on most high end smart phones or tablet computers, making their production more elaborate and expensive.

The printed circuit boards for these devices are no longer considered disposable goods, and their bill of materials start from $150.00, with higher end smart phones going up to $238.00, and tablets well over $300.00....

Publisher: Metcal

Stereo Vision Based Automated Solder Ball Height Detection

Apr 16, 2015 | Jinjin Li, Lina J. Karam; School of Electrical, Computer, & Energy Engineering, Arizona State University, Bonnie L. Bennett, Jeff S. Pettinato;Intel Corporation.

Solder ball height inspection is essential to the detection of potential connectivity issues in semi-conductor units. Current ball height inspection tools such as laser profiling, fringe projection and confocal microscopy are expensive, require complicated setup and are slow, which makes them difficult to use in a real-time manufacturing setting. Therefore, a reliable, in-line ball height measurement method is needed for inspecting units undergoing assembly. (...)

In this paper, an automatic, stereo vision based, in-line ball height inspection method is presented. The proposed method includes an imaging setup together with a computer vision algorithm for reliable, in-line ball height measurement....

Publisher: Intel Corporation

Good Schematics Lead to GOOD LAYOUTS

Apr 08, 2015 | Advanced Assembly

An electronic schematic describes the electrical connectivity of a piece of equipment or an entire system. It is made up of symbols that represent individual components and contains electrical and mechanical information and their related connectivity, along with other important data. Information contained within the schematic is packaged into a printed circuit board (PCB) where the mechanical footprint is placed onto the board and connectivity information is graphically displayed. The more accurate the information contained in the schematic is and the clearer it is presented, the more it contributes to a robust printed circuit board....

Publisher: Advanced Assembly, LLC.

Fix The Process Not Just The Product

Apr 03, 2015 | Mary Elmallakh, M. Sc. and Paul Groome Digitaltest Inc. Andy Shelton Pulse Communications, Inc.

Understanding your process and how to minimize defects has always been important. Nowadays, its importance is increasing with the complexity of products and the customers demand for higher quality. Quality Management Solutions (QMS) that integrate real-time test and inspection results with engineering and production data, can allow the optimization of the entire manufacturing process. We will describe the cost and time benefits of a QMS system when integrated with engineering data and manufacturing processes. We will use real examples that can be derived from integrating this data. This paper also discusses the aspects of Quality Management Software that enables electronic manufacturers to efficiently deliver products while achieving higher quality, reduce manufacturing costs and cutting repair time. Key words: Quality Management Software, ICT, Repair workstations, First Pass Yield, Pareto analysis, Flying Probe, QMS. ...

Publisher: Digitaltest Inc.

Jetting Strategies for mBGAs a question of give and take...

Apr 02, 2015 | Gustaf Mårtensson; BioNano Systems Laboratory, MC2, Petter Svensson, Thomas Kurian; Micronic Mydata AB

The demands on volume delivery and positioning accuracy for solder paste deposits are increasing as the size and complexity of circuits continue to develop in the electronics industry. According to the iNEMI 2013 placement accuracy for these kinds of components will reach 6 sigma placement accuracy in X and Y of 30 um by 2023.

This study attempts to understand the dependencies on piezo actuation pulse profile on jetting deposit quality, especially focused on positioning, satellites and shape. The correlation of deposit diameter and positioning deviation as a function of piezo actuation profile shows that positioning error for deposits increase almost monotonically with decreasing droplet volume irrespective of the piezo-actuation profile. The trends for shape and satellite levels are not as clear and demand further study. ...

Publisher: Mycronic Technologies AB

How to process C4 (FLIPCHIP)

Mar 29, 2015 | Jason Wu

Application Notes – C4 (FLIPCHIP) Category Description of the category The C4 category is used to describe certain area array devices which have solder bumps (bumps) distributed over the surface of the device. The C4 category is also referred to by the name flipchip. In contrast to the BGA devices, C4 devices do not necessarily have the bumps arranged on a regular grid. The C4 algorithm was originally developed for very fine pitch devices. It has since been extended to find (center) larger components....

Publisher: Shenzhen Southern Machinery Sales and Service Co., Ltd

The best way to merger 2 SMT lines in one production line

Mar 28, 2015 | Jason Wu

Saving power consumption more then $30K per year, ROI less 6 months. please contact: jasonwu@smthelp.com or w25605@gmail.com if you are interested....

Publisher: Shenzhen Southern Machinery Sales and Service Co., Ltd

What is Procedure for Measuring the Airflow of the Auto Insertion machine - VCD

Mar 27, 2015 | Jason Wu

This procedure documents the method and apparatus for measuring the average air consumption and the peak air flow for Through Hole -- Axial Insertion Machine....

Publisher: Shenzhen Southern Machinery Sales and Service Co., Ltd

How to design Through Hole PCB

Mar 27, 2015 | Jason Wu

Equipment Throughput Calculation • Simplistic Throughput Calculation – Deduct a basic rule of thumb percentage from the maximum machine cycle rate. – The accuracy of this method is highly questionable. • Effective Throughput Calculation – Machine de-rate calculated using statistical data based on actual run data and component counts. Also considers PPM, Product Changeover, Board – Load/Unload Time, and Downtime....

Publisher: Shenzhen Southern Machinery Sales and Service Co., Ltd

Effectiveness of Conformal Coat to Prevent Corrosion of Nickel-palladium-gold-finished Terminals

Mar 26, 2015 | Michael Osterman

Nickel-palladium-gold-finished terminals are susceptible to creep corrosion. Excessive creep corrosion can result in device failure due to insulation resistance loss between adjacent terminals. The mixed flowing gas test has been demonstrated to produce creep corrosion on parts with nickel-palladium-gold finished terminals. Conformal coats are often used to protect printed wiring assemblies from failure due to moisture and corrosion. However, coating may not be sufficient to protect lead terminations from failure.

In this study, acrylic, silicone, urethane, parylene, and atomic layer deposit (ALD) coatings were examined for their effectiveness at preventing corrosion of nickel-palladium-gold-finished terminals....

Publisher: University of Maryland

Exceptional Optoelectronic Properties of Hydrogenated Bilayer Silicene

Mar 19, 2015 | Bing Huang, Hui-Xiong Deng, Hoonkyung Lee, Mina Yoon, Bobby G. Sumpter, Feng Liu, Sean C. Smith, Su-Huai Wei

Silicon is arguably the best electronic material, but it is not a good optoelectronic material. By employing first-principles calculations and the cluster-expansion approach, we discover that hydrogenated bilayer silicene (BS) shows promising potential as a new kind of optoelectronic material. Most significantly, hydrogenation converts the intrinsic BS, a strongly indirect semiconductor, into a direct-gap semiconductor with a widely tunable band gap. At low hydrogen concentrations, four ground states of single- and double sided hydrogenated BS are characterized by dipole-allowed direct (or quasidirect) band gaps in the desirable range from 1 to 1.5 eV, suitable for solar applications. At high hydrogen concentrations, three well-ordered double-sided hydrogenated BS structures exhibit direct (or quasidirect) band gaps in the color range of red, green, and blue, affording white light-emitting diodes. Our findings open opportunities to search for new silicon-based light-absorption and light-emitting materials for earth-abundant, high efficiency, optoelectronic applications.

Originally published by the American Physical Society...

Publisher: Oak Ridge National Laboratory

Miniaturization with Help of Reduced Component to Component Spacing

Mar 12, 2015 | Jonas Sjoberg, Ranilo Aranda, David Geiger, Anwar Mohammed, Murad Kurwa - Flextronics Advanced Engineering Group

Miniaturization and the integration of a growing number of functions in portable electronic devices require an extremely high packaging density for the active and passive components. There are many ways to increase the packaging density and a few examples would be to stack them with Package on Package (PoP), fine pitch CSP's, 01005 and last but not least reduced component to component spacing for active and passive components (...)

This paper will discuss different layouts, assembly and material selections to reduce component to component spacing down to 100-125um (4-5mil) from today’s mainstream of 150-200um (6-8mil) component to component spacing....

Publisher: Flex (Flextronics International)

Conformal Coating over No Clean Flux Residues

Mar 04, 2015 | K.Seelig, T.O'Neill

As the proliferation of modern day electronics continues to drive miniaturization and functionality, electronic designers/assemblers face the issue of environmental exposure and uncommon applications never previously contemplated. This reality, coupled with the goal of reducing the environmental and health implications of the production and disposal of these devices, has forced manufacturers to reconsider the materials used in production. Furthermore, the need to increase package density and reduce costs has led to the rapid deployment of leadless packages such as QFN, POP, LGA, and Micro-BGA. In many cases, the manufacturers of these devices will recommend the use of no clean fluxes due to concerns over the ability to consistently remove flux residues from under and around these devices. These concerns, along with the need to implement a tin whisker mitigation strategy and/or increase environmental tolerance, have led to the conundrum of applying conformal coating over no clean residues....

Publisher: AIM Solder

Position Accuracy Machines for Selective Soldering Fine Pitch Components

Feb 27, 2015 | Gerjan Diepstraten

The drive towards fine pitch technology also affects the soldering processes. Selective soldering is a reliable soldering process for THT (through hole) connectors and offers a wide process window for designers. THT connectors can be soldered on the top and bottom side of boards, board in board, PCBs to metal shields or housing out of plastic or aluminum are today's state of the art. The materials that are used to make the solder connections require higher temperatures. Due to the introduction of lead-free alloys, the boards need more heat to get the barrels filled with solder. This not only affects the properties of the flux and components, but the operation temperatures of solder machines become higher (...)

First the impact of temperature will be discussed for the separate process steps and for machine tooling. In the experimental part measurements are done to verify the accuracy that can be achieved using today's selective soldering machines. Dedicated tooling is designed to achieve special requirements with respect to component position accuracy....

Publisher: Vitronics Soltec

New Requirements for SIR Measurement

Feb 27, 2015 | Jörg Trodler; Heraeus Materials Technology GmbHo.KG, Mathias Nowottnick, Prof. University of Rostock.

During the last period of newly assembled electrical devices (pcbs), new component types like LGA and QFN were also qualified as well as smaller passive components with reliability requirements based on the automotive and industrial industry. In the narrow gaps under components, residues can accumulate more by the capillary forces. This is not that much a surface resistance than an interface issue. Also that the flux residues under such types of components creates interaction with the solder resists from the pcb, as well as the component body was not completely described in the standard SIR measurement. On the other hand also, electrical influence with higher voltage creates new terms and conditions, in particular the combination of power and logic in such devices. The standard SIR measurement cannot analyze those combinations.

The paper will discuss the requirements for a measurement process, and will give results. The influences of the pcb and component quality will also be discussed. Furthermore it will describe requirements for nc solder paste to increase the chemical/thermical/electrical reliability for whole devices...

Publisher: Heraeus

Numerical Study on New Pin Pull Test for Pad Cratering Of PCB

Feb 19, 2015 | Billy Hu, Jesus Tan

Pad cratering is an important failure mode besides crack of solder joint as it’ll pass the regular test but have impact on the long term reliability of the product. A new pin pull test method with solder ball attached and positioning the test board at an angle of 30º is employed to study the strength of pad cratering. This new method clearly reveals the failure mechanism. And a proper way to interpret the finite element analysis (FEA) result is discussed. Impact of pad dimension, width and angle of copper trace on the strength is included. Some findings not included in previous research could help to guide the design for better performance...

Publisher: Flex (Flextronics International)

Evaluating the Mechanical Reliability of Ball Grid Array (BGA) Flexible Surface-Mount Electronics Packaging under Isothermal Ageing

Feb 12, 2015 | Sabuj Mallik, Ahmed Z El Mehdawi

Electronic systems are known to be affected by the environmental and mechanical conditions, such as humidity, temperature, thermal shocks and vibration. These adverse environmental operating conditions, with time, could degrade the mechanical efficiency of the system and might lead to catastrophic failures.

The aim of this study is to investigate the mechanical integrity of lead-free ball grid array (BGA) solder joints subjected to isothermal ageing at 150°C for up to 1000 hours. Upon ageing at 150°C the Sn-3.5Ag solder alloy initially age-softened for up to 200 hours. This behaviour was linked to the coarsening of grains. When aged beyond 200 hours the shear strength was found to increase up to 400 hours. This age-hardening was correlated with precipitation of hard Ag3Sn particles in Sn matrix. Further ageing resulted in gradual decrease in shear strength. This can be explained as the combined effect of precipitation coarsening and growth of intermetallic layer. The fractured surfaces of the broken solder balls were also investigated under a Scanning Electron Microscope. The shear failures were generally due to ductile fractures in bulk solders irrespective of the ageing time....

Publisher: School of Engineering, University of Greenwich

Rework Stations: Meeting the Challenges of Lead-Free Solders

Feb 12, 2015 | Nigel Charig

Market forces, particularly legislation against the use of lead in electronics, have driven electronics manufacturers towards lead-free solders for PCB assembly and rework. This approach creates challenges because of the relatively high temperatures needed for lead-free soldering. Additionally, lead-free solder alloys typically do not wet or wick as easily as Sn63Pb37 leaded types. As PCBs often include both BGAs and simpler discrete devices, a lead-free rework capability should include a suitable soldering station and a BGA rework station. This article shows how such equipment can be adapted to overcome the lead-free issues and provide a successful reworking facility....

Publisher: Cupio Yestech Europe

Basics of Ball Grid Arrays (BGAs)

Feb 05, 2015 | Advanced Assembly

Ball grid arrays are the boon and bane of engineers and printed circuit board designers the world over. Their unparalleled pin density and low lead inductance are essential in today's high pin count, high frequency integrated circuits. However, that same pin density and unique interface create a challenge unique unto themselves. These challenges need to be faced head on since the ball grid array (BGA) is prevalent in modern PCBs. While there are entire textbooks that cover the topic of BGAs, their use and fanout techniques, the quick overview provided here offers an engineer a good starting point for improving BGA designs....

Publisher: Advanced Assembly, LLC.

An Alternative Solvent with Low Global Warming Potential

Feb 05, 2015 | R. Basu and R. Hulse

In the past 20 yrs the solvent industry has gone through a great deal of change. In the early 1990s, CFC-113 and 1,1,1-trichloroethane were the workhorses of the industry. The Montreal Protocol to phase-out substances that deplete the Earth's protective Ozone Layer was implemented in the mid 1990s. After phase-out of the CFC solvents, the solvent industry fragmented to a variety of cleaning solutions.

The electronics industry was a large user of CFC solvents and many of these applications changed to aqueous based cleaners (...) But those alternatives are now facing various problems: e.g. aqueous based cleaners use a lot of energy, require long drying times, use equipment that requires frequent maintenance, and require a large footprint; no-clean fluxes leave flux residues; and trichloroethylene and n-propyl bromide have toxicity issues. In response to these serious issues newer solvents and blends are being introduced in the marketplace...

Publisher: Honeywell International

BVA: Molded Cu Wire Contact Solution for Very High Density Package-on- Package (PoP) Applications

Jan 28, 2015 | Vern Solberg, Ilyas Mohammed

Stacking heterogeneous semiconductor die (memory and logic) within the same package outline can be considered for less complex applications but combining the memory and processor functions in a single package has compromised test efficiency and overall package assembly yield. Separation and packaging the semiconductor functions into sections, on the other hand, has proved to be more efficient and, even though two interposers are required, more economical. The separated logic and memory sections are configured with the same uniform outline for vertical stacking (package-on-package). The most common configuration places the logic section as the base with second tier memory section soldered to a mating contact pattern.

This paper addresses the primary technological challenges for reducing contact pitch and package-on-package interface technology....

Publisher: Invensas Corporation

Radar Control Terminal (RCT) units

Jan 26, 2015 | Ensil

In 2005 Raytheon Technical Services Company, now Raytheon Information, Intelligence and Services (Raytheon IIS), approached Ensil regarding the repair of their manufactured Radar Control Terminal (RCT) units. The RCT TRS P/N 13563090-2, a key component in the AN/MPQ-64 Sentinel System, consisted of outdated parts which caused minor to major unit failures. Ensil repaired the RCT's at every turn, correcting any component with the parts still in circulation (mother boards, displays, power supplies) to provide the client with the best available technology. These repairs were completed to military standards and kept the RCT effective, allowing for the Sentinel radar to remain operational. However, the supply of outdated parts was eventually no longer available. Ensil offered the best possible solution, utilizing the skills of their knowledgeable engineering staff, they would reverse engineer a new computer to replace the obsolete RCT while maintaining the same form, fit and function....

Publisher: Ensil

High Temperature Ceramic Capacitors for Deep Well Applications

Jan 22, 2015 | R. Phillips, J. Bultitude, A. Gurav, K. Park, S. Murillo, P. Flores, M. Laps.

Temperature requirements for ceramic capacitors have increased significantly with recent advances in deep-well drilling technology. Increasing demand for oil and natural gas has driven the technology to deeper and deeper deposits resulting in extreme temperature environments up to 200°C and above. A novel capacitor solution utilizing temperature-stable base-metal electrode capacitors in a molded and leaded package addresses the growing market high temperature demands of (1) capacitance stability, (2) long service life, and (3) mechanical durability. A range of high temperature C0G capacitors capable of meeting this 200°C and above high temperature environment has been developed.

This paper will review the electrical, reliability, and mechanical performance of this new capacitor solution...

Publisher: KEMET Electronics Corporation

Automotive Safety Systems Driving Growth in Automotive Sensor Cable Assemblies

Jan 12, 2015 | Pete Doyon, VP, Product Management, Schleuniger Inc.

V2V is a collision avoidance technology that transmits data between vehicles to help warn drivers of potential crashes. This technology would improve safety by allowing vehicles to communicate with each other and exchange basic safety data, such as position and speed and warn the driver of potentially dangerous situations....

Publisher: Schleuniger, Inc.

The Effect of Pb Mixing Levels on Solder Joint Reliability and Failure Mode of Backward Compatible, High Density Ball Grid Array Assemblies

Jan 08, 2015 | Richard Coyle, Richard Popowich, Debra Fleming, Peter Read - Alcatel Lucent, Raiyo Aspandiar, Vasu Vasudevan, Steve Tisdale - Intel Corporation, Iulia Muntele - Sanmina Corporation.

Regardless of the accelerating trend for design and conversion to Pb-free manufacturing, many high reliability electronic equipment producers continue to manufacture and support tin-lead (SnPb) electronic products. Certain high reliability electronic products from the telecommunication, military, and medical sectors manufacture using SnPb solder assembly and remain in compliance with the RoHS Directive (restriction on certain hazardous substances) by invoking the European Union Pb-in-solder exemption.

Sustaining SnPb manufacturing has become more challenging because the global component supply chain is converting rapidly to Pb-free offerings and has a decreasing motivation to continue producing SnPb product for the low-volume, high reliability end users. Availability of critical, larger SnPb BGA components is a growing concern...

Publisher: Sanmina-SCI

The Last Will And Testament of the BGA Void

Jan 05, 2015 | Dave Hillman, Dave Adams, Tim Pearson, Brad Williams, Brittany Petrick, Ross Wilcoxon - Rockwell Collins, Dr. David Bernard, John Travis, Dr. Evstatin Krastev, Vineeth Bastin - Nordson Dage.

The impact of voiding on the solder joint integrity of ball grid arrays (BGAs)/chip scale packages (CSPs) can be a topic of lengthy and energetic discussion. Detailed industry investigations have shown that voids have little effect on solder joint integrity unless they fall into specific location/geometry configurations. These investigations have focused on thermal cycle testing at 0°C-100°C, which is typically used to evaluate commercial electronic products.

This paper documents an investigation to determine the impact of voids in BGA and CSP components using thermal cycle testing (-55°C to +125°C) in accordance with the IPC-9701 specification for tin/lead solder alloys. This temperature range is more typical of military and other high performance product use environments. A proposed BGA void requirement revision for the IPC-JSTD-001 specification will be extracted from the results analysis....

Publisher: Rockwell Collins

Profiled Squeegee Blade: Rewrites the Rules for Angle of Attack

Dec 24, 2014 | Ricky Bennett, Rich Lieske - Lu-Con Technologies, Corey Beech - RiverBend Electronics

For centuries, the squeegee blade has been used throughout many applications for depositing viscous materials through screens and stencils to transfer images on to substrates, from cloth material to electronic circuit boards. One area of blade printing mechanics that have been reviewed many times is the angle of attack of the blade. Typically it has been tested from 45 degrees to 60 degrees to optimize the printing quality and efficiency. However, this typically ends up as a compromise, from fill characteristics (45 degrees) to print definition (60 degrees). This paper will present the revolutionary performance of the profiled squeegee blade, which has recently been developed to create a virtual multi angle of attack for unsurpassed process control for all types of stencil printing processes....

Publisher: Lu-Con Technologies

Head in Pillow X-ray Inspection at Flextronics

Dec 18, 2014 | Alejandro Castellanos, Adalberto Gutierrez, Gilberto Martin, Matthew Vandiver, Ranga Dematampitiya, Hung Le, Elliott Le, Phuong Chau, Hao Cui, An Qi Zhao, Wei Bing Qian, Fuqing Li, Jacky Yao, Jiyang Zhang, Leonard Brisan, Cristian Gurka, Shane Young

Manufacturing technology faces challenges with new packages/process when confronting the need for high yields. Identifying product defects associated with the manufacturing process is a critical part of electronics manufacturing. In this project, we focus on how to use AXI to identify BGA Head-in-Pillow (HIP), which is challenging for AXI testing. Our goal is to help us understand the capabilities of current AXI machines....

Publisher: Flex (Flextronics International)

Failure Modes in Wire bonded and Flip Chip Packages

Dec 11, 2014 | Mumtaz Y. Bora

The growth of portable and wireless products is driving the miniaturization of packages resulting in the development of many types of thin form factor packages and cost effective assembly processes. Wire bonded packages using conventional copper lead frame have been used in industry for quite some time. However, the demand for consumer electronics is driving the need for flip chip interconnects as these packages shorten the signals, reduce inductance and improve functionality as compared to the wire bonded packages. The flip chip packages have solder bumps as interconnects instead of wire bonds and typically use an interposer or organic substrate instead of a metal lead frame (...)

The paper provides a general overview of typical defects and failure modes seen in package assembly and reviews the efforts needed to understand new failure modes during package assembly. The root cause evaluations and lessons learned as the factory transitioned to thin form factor packages are shared...

Publisher: Peregrine Semiconductor

Metal-based Inkjet Inks for Printed Electronics

Dec 04, 2014 | Alexander Kamyshny, Joachim Steinke, Shlomo Magdassi

A review on applications of metal-based inkjet inks for printed electronics with a particular focus on inks containing metal nanoparticles, complexes and metallo-organic compounds. The review describes the preparation of such inks and obtaining conductive patterns by using various sintering methods: thermal, photonic, microwave, plasma, electrical, and chemically triggered. Various applications of metal-based inkjet inks (metallization of solar cell, RFID antennas, OLEDs, thin film transistors, electroluminescence devices) are reviewed....

Publisher: Hebrew University of Jerusalem

Preparation, Manufacturing Lead-Free Soldering Alloy

Nov 28, 2014 | Tarik Talib Issa, Asmaa Shawky Khalil

A soldering alloy composition Sn40-Bi60 has been manufactured by quenching method to achieve the both cast and wire shape. Differential scanning calorimetric (DSC) was done to study the melting behavior for a large portion of the alloy melts sharply at a approximately 136 C0 ,the melting point of Sn-Bi. X-Ray diffraction and optical microscopy were used to analyzed its microstructure characterization. The hardness of the alloys has been tested and find at a value 2 HRB as ductile form....

Publisher: University of Baghdad

Effects of Packaging Materials on the Lifetime of LED Modules Under High Temperature Test

Nov 18, 2014 | Lei Nie, Wenjing Xiang - Hubei University of Technology, Mingxiang Chen, Huajing Li, Quan Chen - Huazhong University of Science and Technology

Performance degradation of packaging material is an important reason for the lifetime reduction of LED. In order to understanding the failure behavior of packaging material, silicone and phosphor were chosen to fabricate LED samples within which an aging test at 125℃ was performed. The result of online luminance measurement showed that LED samples with both silicone and phosphor had the highest luminance decay rate among all test samples because the carbonization of silicone and the consequent outgassing reduced the luminance quickly. The result of the luminance variance with test time was analyzed and an exponential decay model was developed with which the lifetime of LED under high temperature could be estimated....

Publisher: Hubei University of Technology

Advanced Thermal Management Solutions on PCBs for High Power Applications

Nov 13, 2014 | Gregor Langer, Markus Leitgeb - Austria Technologie & Systemtechnik AG, Johann Nicolics, Michael Unger - Vienna University of Technology, Hans Hoschopf, Franz P. Wenzl - Joanneum Research Forschungsgesm.b.H.

With increasing power loss of electrical components, thermal performance of an assembled device becomes one of the most important quality factors in electronic packaging. Due to the rapid advances in semiconductor technology, particularly in the regime of high-power components, the temperature dependence of the long-term reliability is a critical parameter and has to be considered with highest possible care during the design phase (...)

The aim of this paper is to give a short overview about standard thermal solutions like thick copper, thermal vias, plugged vias or metal core based PCBs. Furthermore, attention will be turned on the development of copper filled thermal vias in thin board constructions......

Publisher: Tridonic GmbH & Co KG

Effect of Process Variations on Solder Joint Reliability for Nickel-based Surface Finishes

Nov 06, 2014 | Hugh Roberts, Sven Lamprecht, Gustavo Ramos, Christian Sebald

This paper summarizes the results of recent investigations to examine the effect of electroless nickel process variations with respect to Pb-free (Sn-3.0Ag-0.5Cu) solder connections. These investigations included both ENIG and NiPd as surface finishes intended for second level interconnects in BGA applications. Process variations that are suspected to weaken solder joint reliability, including treatment time and pH, were used to achieve differences in nickel layer composition. Immersion gold deposits were also varied, but were directly dependent upon the plated nickel characteristics. In contrast to gold, different electroless palladium thicknesses were independently achieved by treatment time adjustments....

Publisher: Atotech

Solder Joint Reliability Under Realistic Service Conditions

Oct 30, 2014 | P. Borgesen, S. Hamasha, M. Obaidat, V. Raghavan, X. Dai; Department of Systems Science & Industrial Engineering, Binghamton University, M. Meilunas, M. Anselm; Universal Instruments Corporation.

The ultimate life of a microelectronics component is often limited by failure of a solder joint due to crack growth through the laminate under a contact pad (cratering), through the intermetallic bond to the pad, or through the solder itself. Whatever the failure mode proper assessments or even relative comparisons of life in service are not possible based on accelerated testing with fixed amplitudes, or random vibration testing, alone. Effects of thermal cycling enhanced precipitate coarsening on the deformation properties can be accounted for by microstructurally adaptive constitutive relations, but separate effects on the rate of recrystallization lead to a break-down in common damage accumulation laws such as Miner's rule. Isothermal cycling of individual solder joints revealed additional effects of amplitude variations on the deformation properties that cannot currently be accounted for directly.

We propose a practical modification to Miner's rule for solder failure to circumvent this problem. Testing of individual solder pads, eliminating effects of the solder properties, still showed variations in cycling amplitude to systematically reduce subsequent acceleration factors for solder pad cratering. General trends, anticipated consequences and remaining research needs are discussed...

Publisher: Universal Instruments Corporation

5 Questions to Ask Before Choosing a New Cut and Strip Machine

Oct 27, 2014 | Pete Doyon, VP Product Management, Schleuniger, Inc.

A lot of time and effort often goes into finding the right equipment for your facility. Purchasing a new wire cut & strip machine is no different. With so many options, where does one start? Asking these five questions during the decision making process will help ensure you end up with equipment that fits all of your needs. ...

Publisher: Schleuniger, Inc.

Combination of Spray and Soak Improves Cleaning under Bottom Terminations

Oct 23, 2014 | Dr. Mike Bixenman; Kyzen Corporation, Julie Fields; Technical Devices Company, Eric Camden; Foresite.

The functional reliability of electronic circuits determines the overall reliability of the product in which the final products are used. Market forces including more functionality in smaller components, no-clean lead-free solder technologies, competitive forces and automated assembly create process challenges. Cleanliness under the bottom terminations must be maintained in harsh environments. Residues under components can attract moisture and lead to leakage currents and the potential for electrochemical migration (...)

The purpose of this research study is to evaluate innovative spray and soak methods for removing low residue flux residues and thoroughly rinsing under Bottom Termination and Leadless Components...

Publisher: KYZEN Corporation

Oxide Thickness and Solderability Methodology to Determine Long Term Storage of BGAs and QFPs

Oct 16, 2014 | Rama Hegde, senior member of technical staff; Freescale Semiconductor.

Key points are:

*Long-term storage of BGA & QFP products may be required due to:

• Fab and assembly factory transfers
• Product obsolescence requiring customers make lifetime/EOL purchases
• Providing extended service (10+ years) on vehicles
• Other program needs

* Integrity of EOL products in terms of solderability needs to be verified....

Publisher: Freescale Semiconductor Inc

Cleaning Of Assembled PCBs - A Crucial Way of Enhancing Product Reliability and Avoiding Problems in the Field

Oct 09, 2014 | Wilfried Clemens.

Over the last years more and more international newspapers reported in Europe / USA and Japan: "Tunnel train got stuck under the Channel – thousands of people stranded", "Recall of thousands of cars to workshops for control and repair", "Power Failures left households without energy for hours." Very often news like this relate to malfunctions of electric and electronic circuits under adverse conditions or sometimes even in normal operating environment (...)

The presentation will deal with all kinds of aspect of cleaning to ensure the reliability of electronic circuitry in ever changing operation conditions in the most important industrial areas....

Publisher: Kolb Cleaning Technology USA LLC

Assembly Process Feasibility of Low/No Silver Alloy Solder Paste Materials

Oct 02, 2014 | Jennifer Nguyen Ranilo Aranda, David Geiger, and Murad Kurwa

Sn3.0Ag0.5Cu (SAC305) is the most popular near eutectic lead-free alloy used in the manufacturing processes. Over the last several years, the price of silver has dramatically increased driving a desire for lower silver alloy alternatives. As the results, there is a significant increase in the number of alternative low/no silver lead-free solder alloys available in the industry recently.

In this paper, we'll present the performance and process capability of various low/no silver alloy solder pastes. Data from printability, wetting test, slump test, solder ball test, voiding, etc… will be discussed and compared with the control SAC305 solder paste. Benefits and concerns of using low/no silver alloy solder paste materials will also be addressed....

Publisher: Flex (Flextronics International)

Taking the LED Pick and Place Challenge

Sep 25, 2014 | Joshua J. Markle.

For the past few years there has been a shift in the Lighting Industry that has carried over to the surface mount technology assembly line. What is this shift you may ask? Well it is the LED revolution. This revolution or change in lighting has some very promising results already in practice and many more companies looking to implement the LED technology into their product portfolio's. With a number of companies looking to expand their portfolio to include LED fixtures there has been an increase in the number of companies that have started their own SMT lines, as well as a significant number of contract manufacturers to meet this new industries demands (...)

This presentation will discuss some issues in the pick and place process for LEDs and presents a method to troubleshoot and resolve these issues....

Publisher: Cree, Inc.

Predicting the Lifetime of the PCB - From Experiment to Simulation

Sep 18, 2014 | Markus Leitgeb, AT&S Peter Fuchs, PCCL.

Two major drivers in electronic industry are electrical and mechanical miniaturization. Both induce major changes in the material selection as well as in the design. Nevertheless, the mechanical and thermal reliability of a Printed Circuit Board (PCB) has to remain at the same high level or even increase (e.g. multiple lead-free soldering). To achieve these reliability targets, extensive testing has to be done with bare PCB as well as assembled PCB. These tests are time consuming and cost intensive. The PCBs have to be produced, assembled, tested and finally a detailed failure analysis is required to be performed.

This paper examines the development of our concept and has the potential to enable the prediction of the lifetime of the PCB using accelerated testing methods and finite element simulations....

Publisher: AT&S

Plastic vs Metal Stencils for Prototype Printing

Sep 11, 2014 | Bob Wettermann.

This article goes through the pluses and minuses of using plastic stencils for DIY prototypes. The release efficiency is measured and "rules of thumb" for using one type vs another is explained....

Publisher: BEST Inc.

Reliability of Reworked QFNs

Sep 11, 2014 | CRANE.

In this DOD study the reliability of reworked QFNs is studied with the outcome being that a stay in place stencil does not impact the reliability of a QFN reworked using this technique...

Publisher: BEST Inc.