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
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
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
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.
Air-Vac is committed to producing the highest quality rework/repair, selective soldering/desoldering and assembly systems designed with the capability and flexibility required to meet changing customer and industry requirements.
Seymour, Connecticut, United States
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
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
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
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...
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
DfR Solutions has world-renowned expertise in applying the science of Reliability Physics to electrical and electronics technologies, and is a leading provider of quality, reliability, and durability (QRD) research and consulting for the electronics industry.
College Park, Maryland, United States
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