We seem to be having a lot of trouble successfully manufacturing PCB assemblies on which the LMZ12008 is a component. The assembly is being manufacturing in a lead free process that we have successfully used for other similar assemblies. Our normal lead free process for this type of comtrol (size, # of components, types of components, etc.) has a peak reflow temperature of 250 - 255 C. When running at this peak temperature, we have experienced approximately a 50% failure rate of the LMZ12008 prior to applying power, by just measuring 12V to 5V shorts at the appropriate pins. In reversing our process of running at a peak of 240 C, we find that we have numerous other problems in the assembly, due to poor solder joints, but the LMZ12008 survives and performs well when powered. We have also tried putting these on by hand in a post process (after the board has run through the smt oven), but the success rate has been low, because of the temperature required to melt the solder underneath the bottom of the part.
Who has been successfule with processing this part in a lead free process, and can the details of the process be shared with us?
Thanks!
Lou Filo
Owner, APD&M, Inc.
(610) 380-9140
