Effective thermal control for copper leadframe power semiconductor devices is one of the most challenging issues facing package designers and assemblers today. To address the obstacles that these high temperatures can pose, Henkel has developed Multicore® DA100, a robust and highly reliable dispensing grade die attach solder paste.

As power semiconductor devices such as rectifiers, power transistors, amplifiers, voltage regulators and countless other automotive and consumer packages become more demanding from a thermal point of view, new materials will be required at the die level to effectively dissipate the heat they produce. Traditionally, die attach adhesives have been used for these types of devices, but solder-based die attach materials deliver a more cost-effective and efficient thermal approach for certain applications. Multicore DA100 offers the thermal management required, while also providing several other key characteristics and benefits, including ease of removal during cleaning processes, low-voiding, ease of use and cost-efficiency.

Because these devices will travel through very high temperature processes during printed circuit board (PCB) assembly, the solder used must have an extremely high melt point to ensure no component degradation during subsequent assembly processes. Comprised of high lead solder with a liquidus/solidus range of 278°C to 305°C, Multicore DA100 has been optimized for higher temperature processes – typically those in excess of 350°C -- ensuring no adverse effects on the molded package. Another important characteristic of the material is the ease with which the flux residue can be cleaned. Multicore DA100 has been designed so that the flux residues are easily cleaned with various solvent systems and there are no incompatibility issues between the flux residues and the mold compound. In addition, Multicore DA100’s unique flux system maintains the integrity of the copper leadframe, with no copper degradation or corrosion post-cleaning.

Building on Henkel’s success with low-voiding lead-free solder paste systems, Multicore DA100 has also been developed to provide extremely low voids. Understanding how and why voids form and then engineering the flux components to minimize void formation is part of Henkel’s knowledge base and is expertise that has been formulated into Multicore DA100. In testing against other die-attach solder fluxes, Muticore DA 100 exhibited much lower void instances, averaging less than 5% voids – a level which is comparable to the performance of low-voiding assembly solder pastes.

With several competitive advantages including excellent wetting ability, low voiding, ease of die placement, simple and effective residue removal and six-month storage stability, Multicore DA100 is delivering a new level of manufacturing efficiency to packaging specialists worldwide. For more information, please call Henkel’s electronics group headquarters at 949-789-2500 or log onto www.henkel.com/electronics.