Technical Articles From Henkel Electronic Materials

Printed Electronics for Medical Devices

Nov 10, 2020 | Jeff Grover

As is the case with many other markets where faster, highly capable technologies have resulted in more intelligent processes and products, the medical device sector is also undergoing a "smart" transformation. This has driven the development of medical devices that provide greater access to in-home care and monitoring and faster results for medical professionals, with the overarching benefit of better patient outcomes. Devices applied to the human body that commonly sense...

FRACTURE TOUGHNESS OF THERMALLY CONDUCTIVE ADHESIVES

Oct 14, 2020 | John Timmerman, Maria Salamon

Thermally conductive adhesives provide many advantages over traditional mechanical fastening techniques. Specifically, they use less material and space and are more amenable to automation than existing solutions. The thermal and mechanical properties of these materials are well understood but little work has been done to characterize and understand their toughness and fracture behavior. This paper presents the effects of filler loading as well as matrix composition on the fracture toughness of thermally conductive silicone adhesives. It was observed that the fracture toughness of these materials increased significantly with initial filler loading, and that the mechanical properties and fracture toughness depended on the molecular architecture of the matrix used....

Understanding the Effect of Process Changes and Flux Chemistry on Mid-Chip Solder Balling

Nov 30, 2016 | Katherine Wilkerson, Ian J. Wilding, Michael Carter, Daniel Buckland

Mid-chip solder balling is a defect typically associated with solder paste exhibiting poor hot slump and/or insufficient wetting during the reflow soldering process, resulting in paste flowing under the component or onto the solder resist. Once molten, this solder is compressed and forced to the side of the component, causing mid-chip solder balling.

This paper documents the experimental work performed to further understand the impact on mid-chip solder balling from both the manufacturing process and the flux chemistry....

Solder Materials Science Gets Small as Miniaturization Challenges Old Rules

Mar 10, 2011 | Neil Poole, Ph.D. and Brian Toleno, Ph.D.

History shows that the electronics assembly industry is always up for a good challenge. This was proven with the successful move from through-hole to SMT assembly, the elimination of CFCs from the cleaning process and implementation of lead...

Next Best Thing to a Close Shave: Mitigating the Risks of Tin Whiskers

Sep 23, 2010 | Brian Toleno, Ph.D., Henkel Corporation

If you've been in electronics for any length of time, the phenomenon of tin whiskers is something you've likely heard discussed (maybe in scared whispered tones). Tin whiskers certainly aren't a new problem. In fact, some of the first published reports of the occurrence date back to the 1940’s and 1950's. But, over half a century later, we're still talking about it....

Advanced Thermal Interface Materials for Enhanced Flip Chip BGA

Jan 06, 2010 | Punit Kohli, Martin Sobczak, Jeff Bowin, Michael Matthews - Henkel / Ablestik Laboratories

Increased functionality and performance requirements for microprocessors and ASICs have resulted in a trend to package these devices in the flip-chip BGA form factor (FCBGA). Because these devices use in excess of 40-100 Watts of power, their packages must dissipate heat in an extremely efficient manner. Most semiconductor companies have developed some type of thermally enhanced FCBGA package that provides heat dissipation through the back of the die to a heat spreader....

Effect of Reflow Profile on SnPb and SnAgCu Solder Joint Shear Force

Mar 08, 2007 | Jianbiao Pan, Brian J. Toleno, Tzu-Chien Chou, Wesley J. Dee

Reflow profile has significant impact on solder joint performance because it influences wetting and microstructure of the solder joint. The degree of wetting, the microstructure (in particular the intermetallic layer), and the inherent strength of the solder all factor into the reliability of the solder joint. This paper presents experimental results on the effect of reflow profile on both 63%Sn 37%Pb (SnPb) and 96.5%Sn 3.0%Ag 0.5%Cu (SAC 305) solder joint shear force....

Thermal Management of Hybrid Electronic Devices

Jul 21, 1999 | Barry Ritchie, Jamie Serensen

Thermal management is a growing challenge in the electronics industry. As the overall size of electronic devices grows smaller, the enclosed electronic assemblies operate at higher frequencies and generate more heat....

The Effect of Solder Mask And Surface Mount Adhesive Types on a PCB Manufacturing Process.

Jul 21, 1999 | James A. Serenson Jr., Steven Marongelli

A high volume manufacturer of printed circuit boards (PCBs) had attempted for many years to locate an adhesive that was robust enough to meet their manufacturing needs. This proved to be a challenge because they needed the adhesive to accommodate a wide range of different dispensing equipment and board designs. The two key performance criteria required from the adhesive were dispensability and adhesion......

Reliability Considerations of Electrically Conductive Adhesives.

Jul 21, 1999 | Darryl J. Small

Isotropic conductive adhesives are typically silver filled epoxy resins. Electronics assemblers have evaluated these materials for a variety of unique interconnect applications. The goal is a conductive polymer that exhibits similar reliability and performance to traditional solder while offering the benefits of a polymer structure such as low temperature processing and good thermal stability as well as the ability to bond a variety of substrates....

Effects of Tg and CTE on Semiconductor Encapsulants

Jul 21, 1999 | Dr. Mark M. Konarski

As the role of direct-chip-attachment increases in the electronics industry, the reliability and performance of COB packaging materials becomes an increasing concern. Although many factors influence component reliability, the biggest determinants of performance are often the glass transition temperature (Tg) and the coefficient of thermal expansion (CTE) of the encapsulant or underfill. This paper discusses exactly what these properties are, how they are measured, and why they are important to device-reliability....