Electronics Manufacturing Technical Articles

PCB Surface Finishes & Cost Effective Pb Free Assembly Materials

Mar 27, 2014 | Richard Puthota Director – Business Development & CTS India & Africa, Cookson Electronics

The surface finish you select will have a large influence on quality, reliability and cost. It is a complex decision that impacts many areas of the business. Select a finish that optimal for the business (and not just one function). Know that there are engineering tricks to improve on weak areas of each finish. Stay current in this field because new developments continue to be made....

Publisher: Cookson Electronics

Data Bus Components - The Communication System that Helps in Transferring Data

Mar 27, 2014 | Joe Faruqui

Data bus in computer terminology is a communication system that helps in transferring data between components within a computer, or between separate computers. Know more about data bus components and advancements in data bus technology by reading this article....

Publisher: Just Connectors

Today's Vapor Phase Soldering An Optimized Reflow Technology for Lead Free Soldering

Mar 20, 2014 | Dipl.-Ing. Helmut Leicht; Andreas Thumm - IBL-Löttechnik GmbH.

In the beginning of SMT, Vapor Phase Soldering was the preferred reflow soldering technology because of its excellent heat transfer capabilities. There were also some disadvantages like fast temperature rise, nearly no influence on the temperature profiles and high costs. So the use of Vapor Phase Soldering was reduced to special applications with high mass or complex boards in low numbers (e.g. for military or aerospace use)....

Publisher: IBL - Löttechnik GmbH

Stencil Design Guidelines for Electronics Assembly Technologies.

Mar 13, 2014 | Budapest University of Technology and Economics Department of Electronics Technology

A student competition paper at Budapest University of Technology And Economics, Department of Electronics Technology gives background, covers stencil design and discusses stencils intended for pin in paste application. The stencil applied for depositing the solder paste is a thin, 75–200 µm thick metal foil, on which apertures are formed according to the solder pads on the printed circuit board. Stencil printing provides a fast, mass solder paste deposition process; relatively expensive, appropriate and recommended for mass production....

Publisher: Budapest University of Technology and Economics

Investigation and Development of Tin-Lead and Lead-Free Solder Pastes to Reduce the Head-In-Pillow Component Soldering Defect.

Mar 06, 2014 | Jasbir Bath, Roberto Garcia - Christopher Associates Inc. Noriyoshi Uchida, Hajime Takahashi, Gordon Clark, Manabu Itoh - Koki Solder

Over the last few years, there has been an increase in the rate of Head-in-Pillow component soldering defects which interrupts the merger of the BGA/CSP component solder spheres with the molten solder paste during reflow. The issue has occurred across a broad segment of industries including consumer, telecom and military. There are many reasons for this issue such as warpage issues of the component or board, ball co-planarity issues for BGA/CSP components and non-wetting of the component based on contamination or excessive oxidation of the component coating. The issue has been found to occur not only on lead-free soldered assemblies where the increased soldering temperatures may give rise to increase component/board warpage but also on tin-lead soldered assemblies....

Publisher: Christopher Associates Inc.

A Novel High Thermal Conductive Underfill For Flip Chip Appliation

Feb 27, 2014 | Dr. Mary Liu and Dr. Wusheng Yin

Silicon dioxide is normally used as filler in underfill. The thermal conductivity of underfill is less than 1 w/mk, which is not able to meet the current flip chip application requirements such as 3D stacked multi-chips packaging. No matter which direction the heat will be dissipated through PCB or chip, the heat has to pass through the underfill in 3D stacked chips. Therefore the increase of thermal conductivity of underfill can significantly enhance the reliability of electronic devices, particularly in 3D package devices...

Publisher: YINCAE Advanced Materials, LLC.

Screening for Counterfeit Electronic Parts

Feb 20, 2014 | Bhanu Sood and Diganta Das

In this chapter, we discuss the type of parts used to create counterfeits and the defects/degradations inherent in these parts due to the nature of the sources they come from, proposed inspection standards, and limitations of these standards. The processes used to modify the packaging of these parts to create counterfeits are then discussed along with the traces left behind from each of the processes. We then present a systematic methodology for detecting signs of possible part modifications to determine the risk of a part or part lot being counterfeit....

Publisher: CALCE Center for Advanced Life Cycle Engineering

Why Signal Always Be Loss in a High Speed, High Frequency Transmission Line

Feb 13, 2014 | Albert Chen.

The high speed transmission applications in the electronic product become inevitable developing trend. The signal integrity becomes the most important issue in the electronics industry. The material suppliers, PCB manufacturers, OEM designers commonly face the serious issue "how to keep signal integrity operated in the high speed transmission" for the modern electronic application nowadays...

Publisher: Elite Material Co., Ltd.

Understanding SIR

Feb 06, 2014 | Chris Nash, Technical Support Engineer, Eric Bastow, Senior Technical Support Engineer; Indium Corporation.

Many electronics manufacturers perform SIR testing to evaluate solder materials and sometimes the results they obtain differ significantly from those stated by the solder material provider. The difference in the results is typically the result of SIR coupon preparation. This paper will discuss the issue of SIR coupon preparation, board cleaning techniques, and how board cleanliness directly affects SIR results....

Publisher: Indium Corporation

Going Lead Free With Vapor Phase Soldering - Lead Free Is Still a Challenge For Major Industries.

Jan 30, 2014 | Andreas Thumm

As of today, the electronic industry is aware of the requirements for their products to be lead free. All components are typically available in lead free quality. This comprises packages like BGAs with BGA solder balls to PCB board finishes like HASL. The suppliers are providing everything that is needed. It is harder to get the old tin leaded (SnPb) components for new applications today, than lead free ones.

So why has not everybody changed over fully yet and how can the challenges be overcome?

A big concern in this transition process is reflow soldering. The process temperatures for lead free applications became much higher. Related with this is more stress for all the components. It affects the quality and reliability of the electronic units and products......

Publisher: IBL - Löttechnik GmbH

Testing Intermetallic Fragility on Enig upon Addition of Limitless Cu

Jan 23, 2014 | Martin K. Anselm, Ph.D. and Brian Roggeman Universal Instruments Corp.

As reliability requirements increase, especially for defense and aerospace applications, the need to characterize components used in electronic assembly also increases. OEM and EMS companies look to perform characterizations as early as possible in the process to be able to limit quality related issues and improve both assembly yields and ultimate device reliability. In terms of BGA devices, higher stress conditions, RoHS compatible materials and increased package densities tend to cause premature failures in intermetallic layers. Therefore it is necessary to have a quantitative and qualitative test methodology to address these interfaces....

Publisher: Universal Instruments Corporation

Advanced Rework Technology and Processes for Next Generation Large Area Arrays, 01005, PoP and QFN Devices.

Jan 16, 2014 | Brian Czaplicki, Director, Technical Marketing Programs, Air Vac Engineering Co., Inc.

BGA Rework is now largely mature, although new supplemental processes that provide improved process control such as Solder Paste Dipping and Non-Contact Site Cleaning can now be integrated into existing processes if the rework technology that is used allows. So what are the next set of challenges that will need to be addressed in regard to Area Array and SMT Rework? The International Electronics Manufacturing Initiative or iNEMI has recently published its 2013 Technology Roadmap for the global electronics industry which includes a section dedicated specifically to rework and repair. Of particular interest and importance is iNEMI’s gap analysis which identifies future specific gaps and challenges that will result from such factors as government regulations, disruptive technologies and new product requirements....

Publisher: Air-Vac Engineering Co., Inc.

Embedded Passive Technology

Jan 09, 2014 | Hikmat Chammas

Embedded Passive Technology is a viable technology that has been reliably used in the defense and aerospace industry for over 20 years. Embedded Passive (Resistors and Capacitors) Technology have a great potential for high frequency and high density applications. It also provides better signal performance, reduced parasitic and cross talk. This paper summarizes the selection of resistor embedded materials, evaluations of resistive material (Phase 1) and duplication of a complex digital design (Phase 2). Phase 1 –resistive materials (Foil 25Ω/sq NiCr and 1kΩ/sq CrSiO) and resistive-Ply materials (25Ω/sq and 250Ω/sq NiP) were chosen for evaluation....

Publisher: Honeywell International

Thermal Shock and Drop Test Performance of Lead-free Assemblies with No-Underfill and Corner-Underfill

Jan 02, 2014 | Bankeem Chheda and S. Manian Ramkumar, Ph.D.; Rochester Institute of Technology-CEMA, Reza Ghaffarian; Ph.D. Jet Propulsion Laboratory.

With ROHS compliance the transition to lead-free is inevitable. Several lead-free alloys are available in the market and its reliability has been the main concern. The results from this experimental research aims at making a comparison of different lead-free alloy combinations. Thermal shock and drop tests are a part of this experimental study....

Publisher: Jet Propulsion Laboratory

Addressing the Challenge of Head-In-Pillow Defects in Electronics Assembly

Dec 27, 2013 | Mario Scalzo Senior Technical Support Engineer CSMTPE, Six-Sigma Black Belt

The head-in-pillow defect has become a relatively common failure mode in the industry since the implementation of Pb-free technologies, generating much concern. A head-in-pillow defect is the incomplete wetting of the entire solder joint of a Ball-Grid Array (BGA), Chip-Scale Package (CSP), or even a Package-On-Package (PoP) and is characterized as a process anomaly, where the solder paste and BGA ball both reflow but do not coalesce. When looking at a cross-section, it actually looks like a head has pressed into a soft pillow. There are two main sources of head-in-pillow defects: poor wetting and PWB or package warpage. Poor wetting can result from a variety of sources, such as solder ball oxidation, an inappropriate thermal reflow profile or poor fluxing action. This paper addresses the three sources or contributing issues (supply, process & material) of the head-in-pillow defects. It will thoroughly review these three issues and how they relate to result in head-in pillow defects. In addition, a head-in-pillow elimination plan will be presented with real life examples will be to illustrate these head-in-pillow solutions....

Publisher: Indium Corporation

Mixed Metals Impact on Reliability

Dec 19, 2013 | Rick Gunn, Vice President of Engineering / Chief Technology Officer, Nextek Incorporated.

With the adoption of RoHS and implementation of Lead Free solders a major concern is how this will impact reliability. Both commercial and military hardware are impacted by this change even though military hardware is considered exempt from the requirements of RoHS. As the supply chain has moved to the new lead free alloys both markets are being forced to understand these impacts and form risk mitigation strategies to deal with the change. This paper documents the effect of mixing Leaded and Lead Free alloys on BGA devices and how this impacts reliability. Three of the most common pitch BGA packages are included in the study to determine if the risk is the same as pitches decrease...

Publisher: Nextek

Using Physics of Failure to Predict System Level Reliability for Avionic Electronics

Dec 11, 2013 | Greg Caswell, Sr. Member of the Technical Staff, DfR Solutions

Today's analyses of electronics reliability at the system level typically use a "black box approach", with relatively poor understanding of the behaviors and performances of such "black boxes" and how they physically and electrically interact (...) The incorporation of more rigorous and more informative approaches and techniques needs to better understand (...) Understanding the Physics of Failure (PoF) is imperative. It is a formalized and structured approach to Failure Analysis/Forensics Engineering that focuses on total learning and not only fixing a particular current problem (...) In this paper we will present an explanation of various physical models that could be deployed through this method, namely, wire bond failures; thermo-mechanical fatigue; and vibration....

Publisher: DfR Solutions

Impact of FPC Fabrication Process on SMT Reliability

Dec 05, 2013 | Susie Krzmarzick, John Dzarnoski, Yangjun Xing.

The functionality of electronic devices continues to increase at an extraordinary rate. Simultaneously consumers are expecting even more and in ever smaller packages. One enabler for shrinking electronics has been the flexible circuit board that allows the circuit board to fit a wide variety of shapes. Flexible printed circuits (FPC) have the capability to be very thin and can have unpackaged components directly attached using surface mount technology (SMT) and flip chip on flex technologies. Bare die can also be thinned and attached very close to the circuit board. However one caveat of high density flexible circuit boards with thin die is that they can be very fragile. The use of back side films and underfill can protect the die making circuits more robust. For underfill to work well it requires good adhesion to the circuit board which can mean that flux residues under the die normally must be removed prior to underfilling. ...

Publisher: Starkey Hearing Technologies

Improving Density in Microwave Multilayer Printed Circuit Boards for Space Applications

Nov 27, 2013 | Olivier Vendier, Jean-Louis Cazaux, Jean-Luc Lortal; Thales Alenia Space.

The need in complexity for microwave space products such as active BFNs (Beam Forming Networks) is increasing, with a significantly growing number of amplitude / phase control points (number of beams * numbers of radiating elements). As a consequence, the RF component’s package topology is evolving (larger number of I/Os, interconnections densification ...) which directly affect the routing and architecture of the multilayer boards they are mounted on. It then becomes necessary to improve the density of these boards (...) This paper will present the work performed to achieve LCP-based high density multilayer structures, describing the different electrical and technological breadboards manufactured and tested and presenting the results obtained....

Publisher: THALES

Fine Tuning The Stencil Manufacturing Process and Other Stencil Printing Experiments

Nov 21, 2013 | Chrys Shea, Shea Engineering Services; Ray Whittier, Vicor Corporation

Previous experimentation on a highly miniaturized and densely populated SMT assembly revealed the optimum stencil alloy and flux-repellent coating for its stencil printing process. Production implementation of the materials that were identified in the study resulted in approximately 5% print yield improvement across all assemblies throughout the operation, validating the results of the initial tests. A new set of studies was launched to focus on the materials themselves, with the purpose of optimizing their performance on the assembly line (...) Results of the prior tests are reviewed, and the new test vehicle, experimental setup and results are presented and discussed....

Publisher: Shea Engineering Services

Making Sense of Accuracy, Repeatability and Specification for Automated Fluid Dispensing Systems

Nov 14, 2013 | Nordson Asymtek

Understanding accuracy and repeatability is an important step to analyze fluid dispensing system performance. They can also be prone to misinterpretation when reviewing a product specification. A dispensing motion system can be made to perform better or worse under different operating conditions. This article will explain accuracy and repeatability, and how they can be applied to different specifications. It will also discuss key considerations when interpreting accuracy and repeatability for decision making....

Publisher: ASYMTEK Products | Nordson Electronics Solutions

Keeping Pace With Constantly Changing Electronics World.

Nov 07, 2013 | Jorge Maornla.

Today’s customers are more enlightened and aware demanding quality and compact electronics products at competitive prices. Today when a single word spreads out so quickly, no company can afford to put their reputation at stake by manufacturing substandard products....

Publisher: American Progressive Circuits,Inc,

Setting Up a Conformal Coating Facility

Nov 06, 2013 | Dr Lee Hitchens

The set up of a turnkey conformal coating production line or facility, whether it is a batch or inline process, has many similar characteristics. Whether the coating application is based around a high volume selective coating robot, a batch dip coating system or a spray booth, the process requirements tend to be the same. This bulletin reviews the potential needs of the facility, including the process controls, environmental needs and health and safety issues and provides some starting points for a new facility....

Publisher: SCH Technologies

High Performance Multilayer PCBs Design and Manufacturability

Oct 31, 2013 | Judy Warner, Chris Savalia; Transline Technology, Michael Ingham; Spectrum Integrity

Multilayer printed circuit boards (PCBs) that utilize high performance materials are inherently far more challenging for a fabricator to build, due to significant material property differences over standard epoxy glass FR4. These unique material characteristics often require higher processing temperatures, special surface treatments (to aid in hole and surface plating), they possess different expansion properties, making layer-to-layer registration more difficult to control, and require many other unique considerations....

Publisher: Spectrum Integrity, Inc.

Why companies prefer to outsource designing of PCBs?

Oct 30, 2013 | Jorge Maornla

While putting the product in the final market and on store shelves, it is not wise to go for the first idea. Especially in the electronics industry, there is always a scope of improving a product and making it better, more precise and functional....

Publisher: American Progressive Circuits,Inc,

Effect of Reflow Profile on Intermetallic Compound Formation

Oct 24, 2013 | I. Siti Rabiatull Aisha, A. Ourdjini, M. A. Azmah Hanim, O. Saliza

Reflow soldering in a nitrogen atmosphere is a common process consideration in surface mount technology assembly. This is because the use of nitrogen in reflow equipment may benefit the process as well as the quality of the end product, where it can increase the reliability of the solder joint. (...) The present study investigated thoroughly the effect of different reflow soldering atmosphere, which is air and nitrogen on IMC formation and growth...

Publisher: Universiti Teknologi Malaysia

Successful Conformal Coating Masking

Oct 22, 2013 | Dr Lee Hitchens

In conformal coating many components and printed circuit board locations must remain uncoated due to the insulating nature of the coating. The purpose of the conformal coating masking materials is to prevent migration of the conformal coatings into components that need to clear and designated keep out areas. This applies to both liquid conformal coating and Parylene processing. Get this basic process wrong and it can be a big problem, leading to the next stage of either repairing the conformal coating leak, stripping the conformal coating off the circuit board, removing a component to replace it or scrapping the board. This paper reviews typical masking application methods in conformal coating and provides advice on minimising problems. ...

Publisher: SCH Technologies

Looking Forward - The Benefits of Networking your Wire Processing Equipment

Oct 21, 2013 | Pete Doyon, VP Product Management

Having been in the wire processing business for 30 years, I have seen a lot of changes and improvements made possible, primarily by advances in electronics and software. Looking ahead, I see continued improvements in efficiency through networking technology. ...

Publisher: Schleuniger, Inc.

Corrosion Resistance of Pb-Free and Novel Nano-Composite Solders in Electronic Packaging

Oct 17, 2013 | L.C. Tsao

Although several commercial and experimental Pb-free solder alloys are available as replacements for Sn-Pb solders, the following families of solders are of particular interest and are the prevailing choices of industry: eutectic Sn-Ag, eutectic Sn-Cu, eutectic Sn-Zn, eutectic Bi-Sn, and Sn–In. Since the properties of the binary Pb-free solders cannot fully meet the requirements for applications in electronic packaging, additional alloying elements are added to improve the performance of these alloys. Thus, ternary and even quaternary Pb-free solders have been developed, such as Sn-Ag-Cu, Sn-Ag-Bi, and Sn-Zn-Bi solder......

Publisher: National Pingtung University of Science & Technology

Conformal Coating Thickness Measurement

Oct 13, 2013 | Dr Lee Hitchens

The measurement of the conformal coating thickness on a printed circuit board (PCB) to ensure internal and international standards are met is now a critical factor in conformal coating process control. There are several methods for measurement of conformal coating thickness and they fall into two categories. These categories are wet film measurements applied during coating application and dry film measurements made after the coating is dried enough not to damage the coating....

Publisher: SCH Technologies

Designing Circuit Boards for Selective Robotic Coating Application

Oct 13, 2013 | Dr Lee Hitchens

Designing circuit boards for selective robotic spraying of conformal coating can be straightforward if you follow some design rules. Follow them and you can save money and time in your application process. However, if the rules are not followed, the resultant circuit board design can challenge even the most sophisticated conformal coating system and its operator to achieve the finish desired. ...

Publisher: SCH Technologies

Choosing the Right Valve for a Selective Robotic Conformal Coating Application Process

Oct 13, 2013 | Dr Lee Hitchens

When investigating the option of a selective conformal coating process it is crucial to consider the right robotic system and valve combination for the material and circuit board that you wish to coat. To fail to do this can lead to difficult process problems in the production line. This article reviews the various valves available and how they can be used with the typical conformal coating materials in the market and highlights some of the key considerations....

Publisher: SCH Technologies

The Importance of Viscosity in Conformal Coating Process Control

Oct 13, 2013 | Dr Lee Hitchens

There are numerous factors which directly affect the conformal coating process to greater or lesser degrees. Those which have major impacts irrespective of the substrate / PCB and assemblies include choice of coating material and method of application. Whether conformal coating boards by dip, robot, batch spray or brush methods the viscosity of the coating is a critical factor in the overall process control....

Publisher: SCH Technologies

Printed Circuit Board Technology Inspired Stretchable Circuits

Oct 10, 2013 | J. Vanfl eteren , M. Gonzalez , F. Bossuyt , Y.-Y. Hsu , T. Vervust , I. De Wolf , and M. Jablonski

In the past 15 years, stretchable electronic circuits have emerged as a new technology in the domain of assembly, interconnections, and sensor circuit technologies. In the meantime, a wide variety of processes using many different materials have been explored in this new field. In the current contribution, we present an approach inspired by conventional rigid and flexible printed circuit board (PCB) technology....

Publisher: Centre for Microsystems Technology - Ghent University

Pyrolysis of Printed Circuit Boards

Oct 03, 2013 | T. R. Mankhand, K. K. Singh, Sumit Kumar Gupta, Somnath Das

Printed Circuit Board (PCB) is an essential component of almost all electrical and electronic equipments. The rapid growth of the use of such equipments has contributed enormously to the generation of large quantity of waste PCBs. The WPCBs not only contain valuable metals but also a large variety of hazardous materials. Conventional treatments of such WPCBs have their own limitations. By pyrolysis of WPCBs, it is not only possible to obtain the organic part of it as a fuel or useful chemical but can make further processing to recover metals much easier and efficient. In the present work, a kinetic study on the low temperature pyrolysis of WPCBs using a thermogravimetric analyser has been attempted......

Publisher: Indian Institute of Technology ( Banaras Hindu University )

Conformal Coating Process Characterization Considerations

Sep 25, 2013 | Brad Perkins, Nordson ASYMTEK

Conformal coating is an enabling process that allows for the ruggedizing of electronic devices and modules. As the process increases the durability of electronics that are subjected to various end-use environmental conditions, it adds value to the product. While it does add value, consumers and manufacturers expect the electronics to work when subjected to dirt, humidity, moisture, corrosive materials, and various other contaminants. This expectation results in a drive to minimize the cost of the process. The lowest cost of ownership for a conformal coating process occurs by utilizing automated selective conformal coating equipment....

Publisher: ASYMTEK Products | Nordson Electronics Solutions

First Article – First Time

Sep 22, 2013 | Alexei Shkolnik

The PCB-assembly industry in constantly changing. Smaller footprints, new types of components and larger and more complex designs are accompanied by constant competitive pressures. As a result, electronics manufacturers need to continuously adapt their processes and make sure they exploit every opportunity for efficiency gains. This is the only way to improve quality and time to market and to increase profitability....

Publisher: Proventus Technologies

Reliability Performance of Very Thin Printed Circuit Boards with regard to Different any Layer Manufacturing Technologies.

Sep 19, 2013 | Gerhard Schmid, Martin Fischeneder, Gerhard Stoiber

The next generation of smart phones will demand very thin multi-layer boards to reduce the product thickness again. This paper shows three different manufacturing approaches, which can be used for very thin any-layer build-ups. The technological approaches are compared on reliability level – the any-layer copper filled micro-via technology which is to be considered as state of the art technology for high end phones and the ALIVH-C/G technology that is well established in Japan. A test vehicle design featuring test coupons for comprehensive reliability test series has been defined as target application for investigation......

Publisher: AT&S

Improving Product Reliability through HALT and HASS Testing

Sep 09, 2013 | Mark R. Chrusciel, Cincinnati Sub Zero

HALT & HASS technology uses a combination of accelerated stresses to expose product flaws early in the design and manufacturing stages, which improves product reliability and customer confidence. HALT & HASS is used to uncover many of the weak links inherent to the design and fabrication process of a new product as well as during the production phase to find manufacturing defects that could cause product failures in the field....

Publisher: Cincinnati Sub-Zero Products, Inc.

Conformal Surface Plasmons Propagating on Ultrathin and Flexible Films

Sep 05, 2013 | Xiaopeng Shen,Tie Jun Cui,Diego Martin-Cano, Francisco J. Garcia-Vidal

Surface plasmon polaritons (SPPs) are localized surface electromagnetic waves that propagate along the interface between a metal and a dielectric. Owing to their inherent subwavelength confinement, SPPs have a strong potential to become building blocks of a type of photonic circuitry built up on 2D metal surfaces; however, SPPs are difficult to control on curved surfaces conformably and flexibly to produce advanced functional devices. Here we propose the concept of conformal surface plasmons (CSPs), surface plasmon waves that can propagate on ultrathin and flexible films to long distances in a wide broadband range from microwave to mid-infrared frequencies....

Publisher: Southeast University (SEU)

Effect of Gold Content on the Microstructural Evolution of SAC305 Solder Joints Under Isothermal Aging

Aug 29, 2013 | Mike Powers, Jianbiao Pan, Julie Silk, Patrick Hyland

Au over Ni on Cu is a widely used printed circuit board (PCB) surface finish, under bump metallization (UBM), and component lead metallization. It is generally accepted that less than 3 wt.% Au in Sn-Pb solder joints inhibits formation of detrimental intermetallic compounds (IMC). However, the critical limit for Au content in Pb-free solder joints is not well established. Three surface-mount package platforms, one with a matte Sn surface finish and the others with Ni/Au finish, were soldered to Ni/Au-finished PCB using Sn-3.0Ag 0.5Cu (SAC305) solder, in a realistic manufacturing setting. The assembled boards were divided into three groups: one without any thermal treatment, one subjected to isothermal aging at 125°C for 30 days, and the third group aged at 125°C for 56 days... ...

Publisher: Agilent Technologies, Inc.

Whisker Growth In Tin Alloys On Glass-Epoxy Laminate Studied By Scanning ION Microscopy and Energy-Dispersive X-Ray Spectroscopy

Aug 22, 2013 | A. Czerwinski, A. Skwarek, M. Płuska, J. Ratajczak, K. Witek

Tin-rich solders are widely applied in the electronic industry in the majority of modern printed circuit boards (PCBs). Because the use of lead-tin solders has been banned in the European Union since 2006, the problem of the bridging of adjacent conductors due to tin whisker growth (limited before by the addition of Pb) has been reborn. In this study tin alloys soldered on glass-epoxy laminate (typically used for PCBs) are considered. Scanning ion microscopy with Focused Ion Beam (FIB) system and energy-dispersive X-ray spectroscopy (EDXS) were used to determine correlations between spatial non-uniformities of the glass-epoxy laminate, the distribution of intermetallic compounds and whisker growth....

Publisher: The Institute of Electron Technology (ITE)

A Printed Circuit Board Inspection System With Defect Classification Capability

Aug 15, 2013 | I. Ibrahim, S. Bakar, M. Mokji, J. Mukred, Z. Yusof, Z. Ibrahim, K. Khalil, M. Mohamad

An automated visual PCB inspection is an approach used to counter difficulties occurred in human’s manual inspection that can eliminates subjective aspects and then provides fast, quantitative, and dimensional assessments. In this study, referential approach has been implemented on template and defective PCB images to detect numerous defects on bare PCBs before etching process, since etching usually contributes most destructive defects found on PCBs. The PCB inspection system is then improved by incorporating a geometrical image registration, minimum thresholding technique and median filtering in order to solve alignment and uneven illumination problem. Finally, defect classification operation is employed in order to identify the source for six types of defects namely, missing hole, pin hole, underetch, short-circuit, mousebite, and open-circuit....

Publisher: Universiti Teknologi Malaysia

Profiling for Successful BGA/CSP Rework

Aug 14, 2013 | Metcal

This paper discusses how to successfully profile a printed circuit board when reworking Ball Grid Array and Chip Scale Packages....

Publisher: Metcal

Crimp Force Monitoring – The Recipe for Success

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.

Automatic PCB Defect Detection Using Image Substraction Method

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......

Publisher: Al-Falah School of Engineering and Technology

Return of Investment: AOI vs No-AOI

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?”...

Publisher:

Comparing Costs and ROI of AOI and AXI

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......

Publisher: Teradyne

Essentials of SMT - Practical Know How

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....

Publisher:

A Review of Corrosion and Environmental Effects on Electronics

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