Electronics Manufacturing Technical Articles
Papers and articles related to SMT, PCB & EMS industry.
- Technical Library
1140 SMT / PCB Assembly Related Technical Articles
Aug 14, 2013 | Metcal
This paper discusses how to successfully profile a printed circuit board when reworking Ball Grid Array and Chip Scale Packages....
Manufacturer of high-performance precision rework systems for the electronics bench. Product lines include: Hand Soldering and Desoldering, Convection Rework products, Fume Extraction and Fluid Dispensing tools.
Cypress, California, USA
Aug 13, 2013 | Gustavo Garcia-Cota, Crimping Product Manager, Schleuniger, Inc.
One of the common issues I’ve noticed when visiting shops that use crimp force monitors (CFMs) is that the CFMs are usually turned off, regardless of the brand, because engineers and operators are not using them properly. Why, with all of their benefits, are CFMs not being used regularly by employees? One of the biggest problems is the lack of understanding of the variables affecting the CFM’s ability to detect variations. Crimp quality detection is similar to baking a cake. There are a lot of ingredients and if one ingredient is missing or of bad quality, you likely are not going to achieve your desired result. This article will go back through the basics of a crimp quality detection system and discuss what ingredients or variables you need to consider before switching off that CFM. ...
Publisher: Schleuniger, Inc.
Aug 08, 2013 | Sonal Kaushik, Javed Ashraf
In this project Machine Vision PCB Inspection System is applied at the first step of manufacturing, i.e., the making of bare PCB. We first compare a PCB standard image with a PCB image, using a simple subtraction algorithm that can highlight the main problem-regions. We have also seen the effect of noise in a PCB image that at what level this method is suitable to detect the faulty image. Our focus is to detect defects on printed circuit boards & to see the effect of noise. Typical defects that can be detected are over etchings (opens), under-etchings (shorts), holes etc......
Aug 07, 2013 | Titus T. Suck, Orbotech SA
Inspection and test equipment is expensive, produces nothing and does not contribute to the company’s bottom line! Such may be the thinking of many. But as today’s electronic assemblies use more and ever smaller components that are impossible to inspect manually, and components that are impossible to test electrically, the main question is “What costs are manufacturers absorbing because they do not have an Automated Optical Inspection system?”...
Aug 07, 2013 | Peter Edelstein, Teradyne
PCB architectures have continued their steep trend toward greater complexities and higher component densities. For quality control managers and test technicians, the consequence is significant. Their ability to electrically test these products is compounded with each new generation. Probe access to high density boards loaded with micro BGAs using a conventional in-circuit (bed-of-nails) test system is greatly reduced. The challenges and complexity of creating a comprehensive functional test program have all but assured that functional test will not fill the widening gap. This explains why sales of automated-optical and automated X-ray inspection (AOI and AXI) equipment have dramatically risen......
Aug 07, 2013 | Young Bong Kang
This is a practical technical book written by the author based on 24 years of experience. Almost all SMT books, due partially to a few SMT-related books, put weight on equipment, single process or part technology rather than deal with practical process. The book dealing with practical process know-how is rarely found and this is perhaps the first book in which overall SMT practical processes and standards are presented....
Aug 01, 2013 | Rajan Ambat
Electronic industry uses a number of metallic materials in various forms. Also new materials and technology are introduced all the time for increased performance. In recent years, corrosion of electronic systems has been a significant issue. Multiplicity of materials used is one reason limiting the corrosion reliability. However, the reduced spacing between components on a printed circuit board (PCB) due to miniaturization of device is another factor that has made easy for interaction of components in corrosive environments. Presently the knowledge on corrosion issues of electronics is very limited. This paper reviews briefly the materials used in electronic systems, factors influencing corrosion, types of corrosion observed in electronics, and testing methods....
Publisher: Technical University of Denmark
Jul 25, 2013 | Barbara Koczera, An Qi Zhao
Bottom-termination components (BTC), such as QFNs, are becoming more common in PCB assemblies. These components are characterized by hidden solder joints. How are defects on hidden DFN joints detected? Certainly, insufficient solder joints on BTCs cannot be detected by manual visual inspection. Nor can this type of defect be detected by automated optical inspection; the joint is hidden by the component body. Defects such as insufficients are often referred to as "marginal" defects because there is likely enough solder present to make contact between the termination on the bottom-side of the component and the board pad for the component to pass in-circuit and functional test. Should the board be subjected to shock or vibration, however, there is a good chance this solder connection will fracture, leading to an open connection....
Publisher: Flex (Flextronics International)
Jul 18, 2013 | Fan Gao, Karunaharan Rajathurai, Qingzhou Cui, Guangwen Zhou, Irene NkengforAcha, Zhiyong Gu
Lead-free nanosolders have shown promise in nanowire and nanoelectronics assembly. Among various important parameters, melting is the most fundamental property affecting the assembly process. Here we report that the melting behavior of tin and tin/silver nanowires and nanorods can be significantly affected by the surface oxide of nanosolders....
The Chemical Engineering Department boasts an accomplished faculty, a diverse range of programs and degrees and well-established ties to industrial and research institutions.
Lowell, Massachusetts, USA
Jul 11, 2013 | S. Manian Ramkumar Ph.D., Andrew J. Daya, Daniel B. Lewanda; Rochester Institute of Technology, Scott Rushia; MARTIN
This research paper will focus on the effect of various parameters that are used to reball a BGA and their effect on the overall shear strength. Factors that will be looked at include the type of BGA (SAC305 or 63Sn/37Pb), the alloy used to reball (SAC405 or 63Sn/37Pb), the type of flux used (Water Soluble or No Clean), and the environment in which reballing takes place (Nitrogen or Ambient)....
Publisher: MARTIN (a Finetech company)
Jul 11, 2013 | Y. B. Kang
The basic is essential to understand any technology. In SMT, PCB design is an important factor as the technology is fully automated and all the work is performed by machine. Machine is a sensor and it works by sensing the data given to it, so the data should be accurate for quality product. In the attached topic the basics of SMT designing is explained. In the book “Essentials of SMT: Practical Know-How” all the basics of SMT manufacturing is explained in very simple and easy to understand language. ...
Jul 03, 2013 | Bob Wettermann, Hung Hoang
It has been demonstrated in numerous pieces of work that stencil printing, one of the most complex PCB assembly processes, is one of the largest contributors to defects (Revelino et el). This complexity extends to prototype builds where a small number of boards need to be assembled quickly and reliably. Stencil printing is becoming increasingly challenging as packages shrink in size, increase in lead count and require closer lead spacing (finer pitch). Prototype SMT assembly can be further divided between industrial and commercial work and the DIYer, hobbyist or researcher groups. This second group is highly price sensitive when it comes to the materials used for the board assembly as their funds are sourced from personal or research monies as opposed to company funds. This has led to development of a lower cost SMT printing stencil made from plastic film as opposed to the more traditional stainless steel stencil used by industrial and commercial users.This study compares the performance of these two traditional materials and their respective impact on solder paste printing including efficiency and print quality....
Publisher: BEST Inc.
BEST offers professional rework, repair and prototype builds of PCBs. Our expertise is on BGA rework and QFN rework. Our experienced instructors teach professional soldering classes as we are an IPC certified training center
Rolling Meadows, Illinois, USA
Jul 02, 2013 | Don Miller, YesTech Inc.
AOI and AXI systems can address multiple tasks in various locations of the manufacturing process and have become the leading technologies in the quest to identify defects and improve process yields....
Publisher: Nordson YESTECH
Jun 27, 2013 | Industry Council on ESD Target Levels
While IC level ESD design and the necessary protection levels are well understood, system ESD protection strategy and design efficiency have only been dealt with in an ad hoc manner. This is most obvious when we realize that a consolidated approach to system level ESD design between system manufacturers and chip suppliers has been rare. This White Paper discusses these issues in the open for the first time, and offers new and relevant insight for the development of efficient system level ESD design....
Publisher: Industry Council on ESD Target Levels
Jun 20, 2013 | Ricky Bennett; Assembly Process Technologies, Eric Hanson; Aculon
With today's consumer technologies driving the need for denser and more compact devices, the assembly process for surface mounted devices has becoming increasingly more difficult. With the mixture of components requiring a broader range of print deposition volume, various techniques are in use in an attempt to ensure consistent and appropriate paste volume is achieved. Some of these techniques include step etching a stencil locally on a targeted device, promoting electroformed smooth wall nickel stencils, through to laser cutting newer grade stencil materials. This paper focuses on the relevant attributes that affect the properties of solder paste release and introduces the effects of surface free energy with respect to key elements that make up the stencil printing process....
Publisher: Assembly Process Technologies LLC
Jun 13, 2013 | Wei Yao, Cemal Basaran
Electromigration (EM) is a mass transportation mechanism driven by electron wind force, thermal gradient, chemical potential and stress gradient. According to Moore’s law, number of transistors on integrated circuits (ICs) doubles approximately every 2 years. Moore’s law holds true since its introduction in 1970s. This insatiable demand for smaller ICs size, larger integration and higher Input/Output (IO) count of microelectronics has made ball grid array (BGA) the most promising connection type in electronic packaging industry. This trend, however, renders EM reliability of solders joints a major bottleneck to hinder further development of electronics industry......
The purpose of this laboratory is to develop the computational and experimental tools needed to develop the next generation of nanoelectronics and nanophotonics devices.
Buffalo, New York, USA
Jun 05, 2013 | Ed Briggs and Ronald C. Lasky, Ph.D., PE.
The combination of higher lead-free process temperatures, smaller print deposits, and temperature restraints on electrical components has created difficult challenges in optimizing the reflow process. Not only are the electronic components and the PWB at risk, but the ability to achieve a robust solder joint becomes difficult, especially if the PCB is thermally massive. In addition, the constant miniaturization of electronic components, hence smaller solder paste deposits, may require the use of smaller particle-sized powders (...) This paper is a summary of best practices in optimizing the reflow process to meet these challenges of higher reflow temperatures, smaller print deposits, decreased powder particle size, and their affect on the reflow process....
Publisher: Indium Corporation
Jun 05, 2013 | Rob Boyd, Crimping Product Manager
Quality standards are getting tougher each year. In these difficult times, wire harness manufacturers are looking to expand business in their existing markets and are looking for new markets. The following article will compare and contrast the current quality standards that are most commonly used today. It will review proper measurement techniques, discuss some trends in crimp quality, and address methods to improve efficiency in quality data collection....
Publisher: Schleuniger, Inc.
Coating Thickness Measurement of Thin Gold and Palladium Coatings on Printed Circuit Boards using X-Ray Fluorescence
May 30, 2013 | Michael Haller, Volker Rößiger, Simone Dill
This paper covers the following topics: The Measurement Application, Measurement Requirements, Measurement Problems, Measurement Results, Reference Samples, Conclusions ...
Publisher: Fischer Technology, Inc.
As trends towards the miniaturization and increased functional integration of electronics, the demands on quality assurance are rising. FISCHER has many coating thickness measurement solutions for the electronics sector.
Windsor, Connecticut, USA
May 23, 2013 | Daniel Gamota
Printed Electronics is considered by many international technologists to be a platform for manufacturing innovation. Its rich portfolio of advanced multi-functional nano-designed materials, scalable ambient processes, and high volume manufacturing technologies lends itself to offer an opportunity for sustained manufacturing innovation. The success of introducing a new manufacturing technology is strongly dependent on the ability to achieve high final product yields at current or reduced cost. In the past, standards have been the critical vehicles to enable manufacturing success... First published in the 2012 IPC APEX EXPO technical conference proceedings....
Publisher: Printovate Technologies, Inc.
iNEMI HFR-Free PCB Materials Team Project: An Investigation to Identify Technology Limitations Involved in Transitioning to HFR-Free PCB Materials
May 16, 2013 | John Davignon, iNEMI Chair
In response to a growing concern within the Electronic Industry to the transition to Halogen-Free laminates (HFR-Free) within the Client Market space (Desktop and Notebook computers) iNEMI initiated a HFR-Free Leadership Workgroup to evaluate the readiness of the Industry to make this transition. The HFR-Free Leadership WG concluded that the electronic industry is ready for the transition and that the key electrical and thermo-mechanical properties of the new HFR-Free laminates can meet the required criteria. The HFR-Free Leadership WG verified that the laminate suppliers can meet the capacity demands for these new HFR-Free laminates and developed a "Test Suite Methodology" (TSM) that can facilitate the comparison and choice of the right laminate to replace brominated FR4 in the Client space... First published in the 2012 IPC APEX EXPO technical conference proceedings....
Publisher: Intel Corporation
May 10, 2013 | Paul Groome
In today’s manufacturing environments, optimizing manufacturing costs and, especially Test and Inspection costs are high on most company’s agendas. Resources are tight and many employees have multiple roles to fulfill across the whole manufacturing line so, time is limited. Test suppliers need to provide a suite of tools to ensure the highest level of quality for customer shipments. ...
Publisher: Digitaltest Inc.
Digitaltest is a Leading Test Equipment Supplier of; High Accuracy Flying Probe Systems. High Speed, Non-Multiplexed, In-Circiuit Test Solutions. Functional Test Solutions. CAD/CAE, SPC and CAD Translation Software.
Concord, California, USA
May 09, 2013 | Bo Song, Michael H. Azarian and Michael G. Pecht
Atmospheric dust consists of solids suspended in air. Dust is well known for its complex nature. It normally includes inorganic mineral materials, water soluble salts, organic materials, and a small amount of water. The impact of dust on the reliability of printed circuit board assemblies (PCBAs) is ever-growing, driven by the miniaturization of technology and the increasing un-controlled operating conditions with more dust exposure in telecom and information industries... First published in the 2012 IPC APEX EXPO technical conference proceedings....
The largest electronic products research center focused on electronics reliability, is dedicated to providing a knowledge and resource base to support the development of competitive electronic components, products and systems.
College Park, Maryland, USA
May 02, 2013 | Don Banfield
Summary of some new and existing technologies for printed electronics outside of traditional membrane switch manufacturing. Discussion of requirements for understanding the technology of these applications in order to capitalize on them... First published in the 2012 IPC APEX EXPO technical conference proceedings....
Publisher: Conductive Compounds, Inc.
Apr 25, 2013 | Scott Hinaga, Soumya De, Aleksandr Y. Gafarov, Marina Y. Koledintseva, James L. Drewniak
Specification and control of surface roughness of copper conductors within printed circuit boards (PCBs) are increasingly desirable in multi-GHz designs as a part of signal-integrity failure analysis on high-speed PCBs. The development of a quality-assurance method to verify the use of foils with specified roughness grade during the PCB manufacturing process is also important... First published in the 2012 IPC APEX EXPO technical conference proceedings....
Publisher: Cisco Systems, Inc.
Effect of Silicone Conformal Coating on Surface Insulation Resistance (SIR) For Printed Circuit Board Assemblies
Apr 18, 2013 | Carlos Montemayor
Conformal coatings are considered a method of providing corrosion protection to electrical assemblies used in high-humidity or harsh environments. They are applied to PCBs for various reasons: to protect from moisture and contamination, to minimize dendritic growth, to provide stress relief, and for insulation resistance. These contribute to more durable handling, enhanced device reliability, and reduced warranty costs. Increased miniaturization of new circuit board designs requires flexible, low stress coating material to protect delicate components and fine-pitch leads. Silicone conformal coatings offer many advantages that address the general trend of ongoing PCBs designs, such as: high flexibility and low modulus to reduce stress on delicate or small components... First published in the 2012 IPC APEX EXPO technical conference proceedings....
Publisher: Dow Corning Corporation
Apr 12, 2013 | John Mayes, Managing Director - The Paragon Electronics Group
There is much to read about the shifting sands of electronics manufacturing, including current moves by OEMs to alter their EMS relationships to better mitigate risk and cost, while EMS companies look for additional ways in which to adjust their business models in an attempt to improve their profitability. Electronics outsourcing over time evolved from a means to buffer manufacturing demand fluctuations into a wide scale shift in capabilities, in part in order to deal with vastly shorter product life cycles. Following the global economic crash of 2000, aka “the internet bubble,” more and more EMS providers responded by transferring their manufacturing to low cost labour regions, and in particular China. ...
Publisher: JJS Electronics LTD
We're an electronics manufacturing services (EMS) provider based in the UK and Czech Republic delivering reliable and cost-effective electronics assembly, including pcb assembly and test, in addition to electro-mechanical assembly
Lutterworth, United Kingdom
Apr 12, 2013 | Ben Farrer, Business Development Manager, Vigilant Components
As change is inevitable, therefore so is obsolescence. In the electronics sector, stocks of components used in subassemblies will eventually run out, no surprise there! However on many occasions, particularly in the often long product life cycles associated with the traditional UK OEM’s in the industrial, military and medical sectors, to name but three, component supply gets ‘difficult’ long before the customers products themselves reach their ‘end of life’. Component manufacturers work to a commercial agenda; when the popularity of a specific device wanes, or indeed when new features are demanded by the market, they will cease production and redeploy their manufacturing capacity to devices that are being demanded by their high volume customers; the global players....
Publisher: Vigilant Components
Apr 12, 2013 | Chris Johnson is Group Chief Executive of Paragon Electronics Ltd
Here Chris talks about the pitfalls, the paucity of safe options for manufacturers seeking rare components, and his exasperation with organisations that appear to shelve common sense at the first sign of a shortage. He shares his ‘no nonsense’ approach to getting things right first time, and explains his thinking in establishing an independent distributor focused exclusively on delivering 100% component integrity....
Publisher: Vigilant Components
Apr 11, 2013 | Eric Bastow
With the explosion of growth in handheld electronics devices, manufacturers have been forced to look for ways to reinforce their assemblies against the inevitable bumps and drops that their products experience in the field. One method of reinforcement has been the utilization of underfills to "glue" certain SMDs to the PCB. Bumped SMDs attached to the PCB with a no-clean soldering process offer the unavoidable scenario of the underfill coming in contact with a flux residue. This may or may not create a reliability issue... First published in the 2012 IPC APEX EXPO technical conference proceedings...
Publisher: Indium Corporation
Apr 04, 2013 | Todd L Kolmodin, VP Quality
This paper will outline and define what requirements must be adhered to for the OEM community to truly achieve the IPC class product from the Electrical Test standpoint. This will include the test point optimization matrix, Isolation (shorts) parameters and Continuity (opens) parameters. This paper will also address the IPC Class III/A additional requirements for Aerospace and Military Avionics. The disconnect exists between OEMs understanding the requirements of their specific IPC class design versus the signature that will be presented from their design. This results in many Class III builds failing at Electrical Test... First published in the 2012 IPC APEX EXPO technical conference proceedings...
Publisher: Gardien Services USA
Apr 03, 2013 | Don Fitchett
PLC vs PAC Difference & PAC Automation Controller Defined: This PLC vs PAC Difference article defines the PAC automation controller in relationship to the PLC. A PLC vs PAC comparison. Even more importantly, this article explains in great detail the need to differentiate when it comes to requesting and delivering PAC and/or PLC training....
Publisher: Business Industrial Network
A Designed Experiment for the Influence of Copper Foils on Impedance, DC Line Resistance and Insertion Loss
Mar 28, 2013 | Alexander Ippich
For the last couple of years, the main concerns regarding the electrical performance of blank PCB boards were impedance and ohmic resistance. Just recently, the need to reduce insertion loss came up in discussions with blank board customers (...) The paper describes the test vehicle and the testing methodology and discusses in detail the electrical performance characteristics. The influence of the independent variables on the performance characteristics is presented. Finally the thermal reliability of the boards built applying different copper foils and oxide replacements was investigated....
Publisher: Multek Inc.
Mar 27, 2013 | Allen Duck
Vapor phase, once cast to the annals’ of history is making a comeback. Why? Reflow technology is well developed and has served the industry for many years, it is simple and it is consistent. All points are true – when dealing with the centre section of the bell curve. Today’s PCB manufacturers are faced with many designs which no longer fall into that polite category but rather test the process engineering groups with heavier and larger panels, large ground planes located in tricky places, component mass densities which are poorly distributed, ever changing Pb Free alloys and higher process temperatures. All the time the costs for the panels increase, availability of “process trial” boards diminishes and yields are expected to be extremely high with zero scrap rates. The final process in the assembly line has the capacity to secure all the value of the assembly or destroy it. If a panel is poorly soldered due to poor Oven setup or incorrect programming of the profile the recovery of the panel is at best expensive, at worst a loss. For these challenges people are turning to Vapor Phase....
Publisher: A-Tek Systems Group LLC
Distributor of the highest quality SMT assembly equipment. Our 45 years of combined experience and commitment to excellence have earned us the reputation as the premier distributor in the Americas.
Longmont, Colorado, USA
Mar 21, 2013 | C.P. Hunt, O. Thomas, D. Di Maio, E. Kamara, H. Lu
This paper explores the behaviour of a copper test vehicle with multiple reflowed solder joints, which has direct relevance to ball grid arrays (BGA) and high density interconnect structures. The paper explores the relative stress conditions on the distributed joints and the sensitivity to ball joint shape... First published in the 2012 IPC APEX EXPO technical conference proceedings...
Publisher: National Physical Laboratory
Mar 14, 2013 | Reza Ghaffarian, Ph.D.
Commercial-off-the-shelf ball/column grid array packaging (COTS BGA/CGA) technologies in high reliability versions are now being considered for use in a number of National Aeronautics and Space Administration (NASA) electronic systems. Understanding the process and quality assurance (QA) indicators for reliability are important for low-risk insertion of these advanced electronic packages. This talk briefly discusses an overview of packaging trends for area array packages from wire bond to flip-chip ball grid array (FCBGA) as well as column grid array (CGA). It then presents test data including manufacturing and assembly board-level reliability for FCBGA packages with 1704 I/Os and 1-mm pitch, fine pitch BGA (FPBGA) with 432 I/Os and 0.4-mm pitch, and PBGA with 676 I/Os and 1.0-mm pitch packages. First published in the 2012 IPC APEX EXPO technical conference proceedings....
Publisher: Jet Propulsion Laboratory
Mar 12, 2013 | David Lober and Mike Bixenman, D.B.A.
High density and miniaturized circuit assemblies challenge the solder paste printing process. The use of small components such as 0201, 01005 and μBGA devices require good paste release to prevent solder paste bridging and misalignment. When placing these miniaturized components, taller paste deposits are often required. To improve solder paste deposition, a nano-coating is applied to laser cut stencils to improve transfer efficiency. One concern is the compatibility of the nano-coating with cleaning agents used in understencil wipe and stencil cleaning. The purpose of this research is to test the chemical compatibility of common cleaning agents used in understencil wipe and stencil cleaning processes.Compatibility of Cleaning Agents With Nano-Coated Stencils...
Publisher: KYZEN Corporation
Mar 07, 2013 | Michael Matthews, Ken Holcomb, Jim Haley, Catherine Shearer
The market for high-layer-count printed circuit boards (PCB) containing blind and buried vias was once relatively small, and focused on specialized applications in the military and high end computing. The demand for these types of PCBs today is being driven by an increasing number of commercial applications in the telecommunications and semiconductor test market segments. These applications typically require high-aspect-ratio plated-through-holes (PTHs) and blind and buried vias in order to meet the applications interconnect density requirements. Blind and buried vias and high aspect ratio PTHs continue to present manufacturing challenges and frequently are the limiting features to achieving high fabrication yield... First published in the 2012 IPC APEX EXPO technical conference proceedings...
Publisher: Ormet Circuits, Inc.
Manufacturer of sintering, electrically conductive materials. Applications include semiconductor die attach, component attach, via fill, z-axis interconnection, conductive lines and traces and plated-through hole fill.
San Diego, California, USA
Mar 07, 2013 | Pete Doyon, VP of Product Management
No one can deny that organizations across the country have been greatly affected by the decline in the economy. The manufacturing industry is no different. Even now as things seem to be looking up, companies are continually looking to cut costs and increase efficiencies. In addition, these companies must remain compliant with the strict quality and safety standards of the industry, adding even more pressure. Because of this, innovative, automated and easy to use products are needed more than ever before to help companies achieve their goals....
Publisher: Schleuniger, Inc.
Mar 04, 2013 | Anthony A. Primavera Ph.D.
Chip-scale (or chip-size) packages are rapidly becoming an important element in electronics due to their size, performance, and cost advantages [Hou, 1998]. The Chip Scale Package (CSP) is becoming a key semiconductor package type, particularly for consumer products. Due to their relatively smaller size, new challenges are presented in the rework and repair of CSPs. (...) The specific focus of this paper is the removal process for rework of CSPs and the site scavenging methods required to properly prepare the circuit board for a new component. Process factors such as the heating, fluxing and, atmosphere are discussed....
Publisher: Universal Instruments Corporation
Feb 28, 2013 | Keith Sweatman, Tetsuro Nishimura, Stuart D. McDonald, Kazuhiro Nogita
While it has long been known that the Cu6Sn5 intermetallic that plays a critical role in the reliability of solder joints made with tin-containing alloys on copper substrates exists in two different crystal forms over the temperature range to which electronics circuitry is exposed during assembly and service, it has only recently been recognized that the change from one form to the other has implications for solder joint reliability. (..) In this paper the authors report a study of the effect of cooling rates on Cu6Sn5 crystals. Cooling rates from 200°C ranged from 10°C/minute to 100°C/minute and the effect of isothermal ageing at intermediate temperatures was also studied. The extent of the phase transformation after each regime was determined using synchrotron X-ray diffraction. The findings have important implications for the manufacture of solder joints and their in-service performance... First published in the 2012 IPC APEX EXPO technical conference proceedings.......
Publisher: Nihon Superior Co., Ltd.
Nihon has been a leader in soldering and brazing since 1966. Nihon manufactures SMT solder joining materials e.g. lead-free solder (SN100C:Sn-Cu-Ni-Ge etc): solder paste, solder spheres, flux cored solder wire, solder bar, etc.
Feb 22, 2013 | LPKF
Productivity. Innovation. Time to market. Day to day, year over year, businesses are forced to make critical R.O.I.—related decisions that impact the future and the bottom line—some of them reactionary, some forecasted. For a growing number of electronics manufacturers, many of those decisions revolve around whether a function should be performed by an outside contractor or kept in-house. But for many companies in the RF/microwave industry, this decision is often concerned with continuing to employ an outside PCB fabricator for prototype PCBs, or to make a $10,000 to $100,000 investment in an inhouse, rapid PCB prototyping machine that may represent a key competitive advantage....
Publisher: LPKF Laser & Electronics
Feb 14, 2013 | Christopher Cain
Boundary-scan (1149.1) technology was originally developed to provide a far easier method to perform digital DC testing to detect intra-IC interconnect assembly faults, such as solder shorts and opens. Today's advanced IC technology now includes high-speed differential interfaces that include AC or DC coupling components loaded on the printed circuit assembly. Simple stuck-at-high/low test methods are not sufficient to detect all assembly fault conditions, which includes shorts, opens and missing components. Improved diagnostics requires detailed circuit analysis, predictive assembly fault simulation and more complex testing to isolate and accurately detect all possible assembly faults... First published in the 2012 IPC APEX EXPO technical conference proceedings...
Publisher: Agilent Technologies, Inc.
Feb 08, 2013 | Richard Lathrop
Solder voiding is present in the majority solder joints and is generally accepted when the voids are small and the total void content is minimal. X-ray methods are the predominate method for solder void analysis but this method can be quite subjective for non grid array components due to the two dimensional aspects of X-ray images and software limitations. A novel method of making a copper "sandwich" to simulate under lead and under component environs during reflow has been developed and is discussed in detail. This method has enabled quantitative solder paste void analysis for lead free and specialty paste development and process refinement. Profile and paste storage effects on voiding are discussed. Additionally an optimal design and material selection from a solder void standpoint for a heat spreader on a BCC (Bumpered Chip Carrier) has been developed and is discussed....
Feb 07, 2013 | John Meyer and Carlyn A. Smith, Ph.D.
Silicone contamination is known to have a negative impact on assembly processes such as soldering, adhesive bonding, coating, and wire bonding. In particular, silicone is known to cause de-wetting of materials from surfaces and can result in adhesive failures. There are many sources for silicone contamination with common sources being mold releases or lubricants on manufacturing tools, offgassing during cure of silicone paste adhesives, and residue from pressure sensitive tape. This effort addresses silicone contamination by quantifying adhesive effects under known silicone contaminations. The first step in this effort identified an FT-IR spectroscopic detection limit for surface silicone utilizing the area under the 1263 cm-1 (Si-CH3) absorbance peak as a function of concentration (µg/cm2). The next step was to pre-contaminate surfaces with known concentrations of silicone oil and assess the effects on surface wetting and adhesion. This information will be used to establish guidelines for silicone contamination in different manufacturing areas within Harris Corporation... First published in the 2012 IPC APEX EXPO technical conference proceedings....
Publisher: Harris Corporation
Jan 31, 2013 | Joe Thomas
There are three key industry trends that are driving the need for temperature-dependent warpage measurement: the trend toward finer-pitch devices, the emergence of lead-free processing, and changes in device form factors. Warpage measurement has become a key measurement for analysis; prevention and prediction of interconnect defects and has been employed in failure analysis labs and production sites worldwide. First published in the 2012 IPC APEX EXPO technical conference proceedings...
Publisher: ZN Technologies
Jan 30, 2013 | Pete Doyon, VP of Product Management
Many OEM’s require that individual wires and cables used in their products be clearly identified with a mark or label. For some, such as in the military and aerospace markets, wire and cable identification (or “wire ID”) is mandatory and the process is governed by stringent specifications, such as SAE AS50881 (formerly MIL5088L). For others, the decision to use wire ID is a voluntary one. This article will describe what type of information is typically identified on wire and cables, concepts for improved productivity, what types of systems are available and the pros and cons of each....
Publisher: Schleuniger, Inc.
Jan 29, 2013 | Pete Doyon, VP Product Management
Choosing a new wire Cutting and Stripping (C&S) machine can be like shopping for a new car. With so many choices, where does one start? A nice, little sports car might be fun to have, but how often will it just sit there because it can’t carry a car load of kids or some odd-sized goods from the local home improvement store? You just might be better off with a midsize SUV that does a pretty good job at doing everything you need it to do....
Publisher: Schleuniger, Inc.
Jan 24, 2013 | Roland Girouard
Being found in the search engines for a wide variety of terms directly related to my business would be my 1st priority......
An investigation into low temperature tin-bismuth and tin-bismuth-silver lead-free alloy solder pastes for electronics manufacturing applications
Jan 24, 2013 | Jasbir Bath, Manabu Itoh, Gordon Clark, Hajime Takahashi, Kyosuke Yokota, Kentaro Asai, Atsushi Irisawa, Kimiaki Mori, David Rund, Roberto Garcia
The electronics industry has mainly adopted the higher melting point Sn3Ag0.5Cu solder alloys for lead-free reflow soldering applications. For applications where temperature sensitive components and boards are used this has created a need to develop low melting point lead-free alloy solder pastes. Tin-bismuth and tin-bismuth-silver containing alloys were used to address the temperature issue with development done on Sn58Bi, Sn57.6Bi0.4Ag, Sn57Bi1Ag lead-free solder alloy pastes. Investigations included paste printing studies, reflow and wetting analysis on different substrates and board surface finishes and head-in-pillow paste performance in addition to paste-in-hole reflow tests. Voiding was also investigated on tin-bismuth and tin-bismuth-silver versus Sn3Ag0.5Cu soldered QFN/MLF/BTC components. Mechanical bond strength testing was also done comparing Sn58Bi, Sn37Pb and Sn3Ag0.5Cu soldered components. The results of the work are reported....
Publisher: Christopher Associates Inc.