New-Tech Europe Magazine | Q1 2023

yes, your solder paste will work with Samtec connectors, with very few exceptions. Are there any new soldering materials that are gaining interest? DD: We see a lot of interest in low-temperature solder paste. Of course, lead-free technology requires higher temperature processing. The melting point of most SAC lead-free solder pastes is about 217° C, and that’s up from approximately 183° C for tin-lead solder paste. That’s a significant jump in paste melting temperature. With that delta, from tin-lead temperatures to lead-free, many customers are concerned about component warpage, and potential discoloration of heat-sensitive devices and platings. Solder paste manufacturers are working on other chemistries and technologies to lower the processing temperature. The ones we see the most with regard to lowering that melting temperature contain bismuth or indium. These new pastes can lower the melting temperature to 140° C. And we know that every benefit has a disadvantage, and the primary disadvantage with these low temperature pastes is brittle, less robust solder joints. In my opinion, there’s still some work to be done by these solder paste manufacturers. Shou l d I p r e - b a k e my components prior to soldering? DD: Samtec connectors, and SMT connectors in particular, do not require pre-baking. Per IPC/JEDEC J-STD 020E, our connectors do not require pre-baking because the moisture sensitivity level of our connectors is 1. Some customers do decide to pre bake, and it’s not going to hurt the connectors. The need for pre-baking is because of entrapped water in the

Credit: Samtec

If a connector coplanarity spec is .006”, what stencil thickness should I use for the best solder joints? DD: This is another question that we are asked just about every day. A connector coplanarity specification

device or component; pre-baking evaporates any trapped water content in that device/component. Pre-baking might be more of a concern if your inventory or manufacturing facility is located in a place with higher humidity levels.

Credit: Samtec

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