High thermal conductivity materials for high power applications 08 April 2021

Henkel has developed the patent-pending LOCTITE® ABLESTIK® ABP 8068T portfolio, which includes high thermal, semi-sintering die attach pastes that offer simplified processing, as well as ‘best in class’ thermal and electrical performance – with robust reliability for today’s high power density devices.

The expanded functionality and shrinking dimensions of devices within mobile, datacom/telecom, consumer and automotive applications are driving increased power densities and resulting in the need to manage heat dissipation more effectively. The use of thermal interface materials provides this relief at the board and component level, but more capable solutions at the die level are an important piece of the holistic thermal management equation.

“Historically, solder has been the predominant solution for high thermal and electrical performance,” explains Raj Peddi, Henkel market segment head for Wirebond IC Packaging. “However its impending phase out, due to environmental legislation, is driving the need for alternative materials. Other approaches such as conventional high thermal die attach adhesives and pure silver sintering products are also less than ideal because of interfacial contact limitations and processability challenges. For these reasons, Henkel developed the LOCTITE® ABLESTIK®  ABP 8068T series of semi-sintering die attach materials, which combine high thermal conductivity, robust reliability and simplified manufacturing processes.”

Henkel’s new adhesives provide a lead-free alternative for die attach within high power density semiconductor packages. The materials can be implemented using standard processes without the need for high pressure and temperature, as is the case with conventional silver sintering materials. Because the novel die attach pastes form an interpenetrating network of sintered silver (Ag) and resin, they establish excellent contact with the interface for void-free bond lines. This achieves outstanding thermal conductivity and results in good thermal cycling performance. LOCTITE ABLESTIK ABP 8068T series materials are a drop-in replacement solution for standard die attach applications; can be cured with nitrogen or air; and have robust adhesion on a variety of surface finishes including silver, copper, nickel-palladium-gold and gold.

Other attributes of this new series of materials include applicability on a wide range of die sizes up to 5mm x 5mm; excellent thermal performance with bulk thermal conductivity up to 110 W/m-K; low in-package resistance of about 0.5kW for silver, copper and nickel-palladium-gold lead frames; as well as broad workability that includes consistent dispensing up to 24 continuous hours, open time of two hours and stage time of as long as four hours.

“For packaging specialists that want a lead-free replacement for solder that doesn’t require expensive or complicated processing, yet ensures equal or better performance as compared to conventional materials, the LOCTITE ABLESTIK ABP 8068T portfolio delivers,” comments Raj. 

Claire Aldridge Deputy Editor t: +44 (0) 1727 743 889

Having joined the magazine in 2012, Claire developed her knowledge of the industry through the numerous company visits, exhibitions and conferences she attended both in the UK and abroad.

Claire prides herself on keeping readers well informed and up to date with the latest industry news.