BESTProto has been retooling our look. The outside of our building now has some attractive signage identifying our business location right on the Route 53 corridor. Secondly, we now have a capabilities brochure which describes more fully the ways in which we can serve your manufacturing needs. A new look to our web presence is also forthcoming.

In this newsletter we learn about the “head on pillow” defect which can develop during the  building of lead free assemblies.

I also invite you to check out the review on the spy camera  in ourGadget Review corner.

“Head on Pillow” Defects

One specific type of defect that we have seen routinely on lead-free ball grid arrays (BGAs) is called “head-on-pillow”. Head-on-pillow is a defect where both the paste deposit and the solder ball reach a full state of melt but fail to coalesce. With head-on-pillow the soldering temperature is sufficient to fully melt the solder bump and paste deposit, but an impediment develops to the proper formation of a solder joint. One or both ends of the intermittent or failed interconnect will show evidence of displacement while it was melted, forming a shape that resembles that of a pillow with an indentation of your head. Intermittent opens are the result.

“Dye and pry” testing is used to identify the presence of head-on-pillow defect. The dye applied during this test can penetrate the gap formed between the two ends of the poorly connected solder joint and can be identified when the component is removed from the PCB.

Proper care in profiling, proper material and component selection will prevent these problems fro occurring. This is why you chose a professional assembler with lots of experience.
Wishing you a happy holiday season!