ZESTRON, the global leading provider of high precision cleaning products, services, and training solutions in the electronics manufacturing and semiconductor industries, is pleased to release the whitepaper “Impact of high reflow temperature on flux removal with high Pb solder paste”

Whitepaper Abstract:

High power discrete package commonly uses high lead (Pb) solder paste as die attach and interconnect material. High lead (Pb) solder paste is an ideal material and unreplaceable until present because of its low resistance, high thermal conductivity, and high melting point to sustain multiple reflow cycles. The alloy composition of the most commonly used solder paste are Pb92.5Sn5Ag2.5 and Pb95Sn5 which having a liquidus temperature of >300°C.

Voiding in solder joint is an on-going problem especially for power electronics. Void, caused by lack of solder or poor wetting in the solder bonds, will slow down or limit the heat dissipation of the power discrete packages, which can lead to thermal failure. By increasing the soldering profile peak temperature or prolong the soldering time, voids reduction can be achieved. However, this leads to an increase in the flux activity during reflow soldering process and resulted flux hardening condition. Proper cleaning of the discrete packages is essential after reflow soldering to remove the flux residue generated from die attach and clip attached (DACA).

To find out the impact of cleaning effectiveness against the different peak reflow temperatures on the discrete packages, the authors had developed a series of test plan to evaluate the cleaning effectiveness for the discrete packages soldered with the common high lead solder pastes that available in the market. For more information or to request for this free whitepaper, please email us at infoasia@zestron.com

ZESTRON is founded in Ingolstadt, Germany and operates in more than 35 countries. With eight technical centers worldwide and the industry’s most knowledgeable team of engineers focused on high precision cleaning, ZESTRON’s commitment to ensuring that its customers surpass even the most stringent cleaning requirements.

For additional information or to tour one of our technical centers, please visit zestron.com