Advancing technology frequently requires an accompanying advancement in materials technology. Recently,these advances are also driven by changes in environmental legislation as well. Specifically,the RoHS legislation has mandated a move away from lower-temperature Sn/Pb solders to higher reflow temperature SAC alloys on the PCB assembly. This change in reflow temperature drives changes to materials used inside packages as well. In addition to material composition changes,component geometry,spacing,and design drive new process capability. In this paper we will discuss the testing
and evaluation of a new die attach solder paste material,the design considerations for both process and alloys. We will discuss the requirements for these materials used in high power packages and the material properties needed to deliver on these requirements.

As margins on electronics technology have continued to erode,an increasing number of organizations have implemented design for reliability practices to ensure device performance while meeting tight product development guidelines. There are numerous aspects of DfR principles,including specification development,part selection and derating,design review by failure mod (DRBFM),and physics of failure (Pof). Often overlooked by the "science of success," Pof will play a crucial role in future design activities as an increasing number of technologies are designed with limited lifetimes. Components of concern have broadened from the traditional LEDs and electrolytic capacitors into sub-90nm integrated circuits and solder joint fatigue. This presentation will provide a history and overview of PoF and where it fits into the overall scheme of DfR. Of critical importance will be a discussion on which organizations and standards bodies will start to require PoF and how to implement PoF into your design activities to ensure product success and compliance with the next generation of industry specifications.

High reliability applications in the military and aerospace industry require reliable solder finish
identification on components within the supply system of DoD,NASA,and many other organizations. Consumer products and military/aerospace industry commonly share the same suppliers of electronic components. The RoHS regulation has forced those suppliers to provide lead free solder solutions. As a result,components with many different solder finishes are now available. Compatibility issues,among
those various solder finishes such as melting temperatures,tin whisker formation,stress fracturing etc. create a serious reliability problem the military/aerospace industry is trying to overcome. A new technique has been developed to reliably identify unknown samples or materials utilizing XRF instrumentation. The technique will help in identifying quickly and reliably bulk and surface finish solders of individual components as well as populated boards. This new identification tool can be used for any application and is particularly helpful if suitable standards are unavailable. Fischer Technology will present practical examples for solder analyses. The method will also assist the user to identify the correct measurement application which can then be used to make a full quantitative analysis if desired.

BGA’s,ceramic capacitors,and similar strain sensitive components are used extensively throughout the automotive and consumer electronics industries. Unfortunately these components can be easily damaged when exposed to excessive board strain and flex and induce microscopic defects within the components that typically are undetectable. Additional thermal and mechanical cycling can cause these defects to propagate over time and ultimately lead to component failure,product failure,and customer dissatisfaction. Since defect detection is ineffective,defect prevention is the key to success.
This paper will review in depth the various failure modes,identify high risk assembly processes,and outline the critical prevention strategies that need to be implemented to produce a defect-free quality product. Topics will cover product design,process design,and verification strategies.

Like many other electronics industries,the automotive electronics industry has long been concerned about ESD. As dramatically seen in the news today,quality recalls can detrimentally affect the faith and loyalty that a customer has for a company’s products. Automotive collision avoidance radar systems,Telematics and some audio products are currently made with parts that are extremely sensitive to ESD. Robust ESD controls at the vehicle electronic system suppliers are needed to protect their customers from ESD. This in most cases can be done by complying with the ESD control industry’s standards ANSI/ESD S20.20 and IEC 61340-5-1. The ESD controls built around these standards have been successfully used for over the past 20+ years,but will need improved upon for more sensitive future devices. In addition,ESD control issues at the assembly plant will also be discussed as current guidelines may need to be improved given the growing trend for more sensitive electronics in vehicles and at the same time,the explosion of even more vehicle parts made from static generative plastics.

• Genesis in December 2008
• Follow-up discussions APEX 2009
• Input received from SMEs
• Conference Call July 22,2009
• Discussions IPC Midwest 2009
• First white paper issued by IPC SPVC June 2010

Using X-ray imaging,solder corrosion,resembling metal migration,had been observed under QFN (Quad Flat No-Lead package) devices and chip resistors on circuit boards that were processed with two SAC 305 alloy solder pastes after 500 hours of exposure to 85ºC and 85% R.H. with no applied voltage. Analysis of the material under QFN’s by SEM (scanning electron microscopy) and energy-dispersive X-ray spectroscopy showed it was primarily a tin compound. This phenomenon was only observed for components that had a relatively large quantity of flux residue trapped underneath them. Further investigation was made using six different SAC305 alloy solder pastes and solder paste test coupons with copper OSP and NiAu metal surface finishes. The test coupons were examined with X-ray imaging before exposure to 85ºC and 85% R.H. and then after 250,500,750 and 1000 hours of exposure. On the NiAu boards,tin corrosion was observed for five of the six pastes after 250 hours exposure,and after 750 hours exposure for the sixth paste. For OSP boards,three pastes showed corrosion after 250 hours,an additional paste after 750 hours,and two pastes showed no corrosion after 1000 hours exposure. The corrosion is dependent on solder paste flux chemistry,solder alloy and the board’s metal finish. The investigation discussed here concerns three solder paste flux chemistries,SAC305 and 63 Sn 37 Pb alloys and 3 reflow conditions. Flux chemistry had the greatest effect on tin corrosion under QFN components; however SAC305 corroded faster than 63 Sn 37 Pb. Reflow conditions had almost no effect.

The effects of nano-TiO particle additives on the microstructure and microhardness of the 2 Sn3.5Ag0.5Cu composite solder were studied. Results show that alloying with nano-TiO 2 particles dramatically reduced the formation of primary ß-Sn phase,the average size of Ag3Sn phase,and the spacing lamellae in the Sn3.5Ag0.5Cu composite solder. This is attributed to the adsorption of nano-TiO2 particles with high surface free energy on the grain surface during solidification. Microhardness improved with the addition of nano-TiO 2 particles,which refinded Ag Sn INCs. The refined IMCs acted as a strengthening phase in the 3 solder matrix and enhanced the Vicker’s microhardness of the Sn3.5Ag0.5Cu composite solders,which corresponds well with the prediction of the classic dispersion strengthening theory.

In globally competitive markets,managing product quality,reliability and risk is not an option. However,it also brings its own unique set of challenges to complex organizations:
- Product design teams need to gain early insight into product reliability - A systematic process is needed to plan for quality,and to identify and mitigate risks - The product design must be more closely aligned with customer requirements - Reliability and quality must be balanced with lifecycle costs and profitability - A centralized system is required to enable guided corrective actions and prevent repeat issues Today,many companies struggle with these demands,creating fragmented tools and processes that delay analysis and prevent communication,the consequences of which range from undesirable to catastrophic,including: Escalated costs,undetected risks,product recalls,decreased consumer confidence,and loss of market share. Customer demands and government oversight have never been greater,which is further amplified with 24 hour access to consumer blogs and media coverage. Every corporate boardroom is forced to consider the
impacts of quality,reliability and risk on their business.

- Regulations are driving increasing IPC-1752 use
- More restricted substances and product categories in scope
- The business challenge is much bigger than “regulatory compliance”
- Teams increasingly manage multiple,evolving standards
- Business goal: Early visibility
- How? Systematically acquire,validate,and maintain environmental data
- Progressive disclosure
- Required: Data Management and Systems Integration
- Enabling continuous data acquisition & analysis
- Compliance Summary: Key Business Needs
- Product Environmental Performance is the next wave
- Driver: Product environmental footprint
- Life Cycle Environmental Impact
- Extended BOM for LCA Modeling and Regulatory Compliance