New-Tech Europe Magazine | Q1 2023

Practical Guidelines To Achieve Quality Connector Solder Joints

By Danny Boesing, Samtec

Part One Many factors affect the quality and performance of a connector: pin material, the quality of the stamping, the quality of and choice of surface finish, and the tolerances on the plastic insulator, just to name a few. Beyond the connector, another factor that is crucial to the performance of the connector on the printed circuit board is the quality of the solder joints. This is the first in a series of three blogs, which are interviews with David Decker, the Manager of Samtec Interconnect Processing Group (IPG). In these blogs, David answers some of the most frequently asked questions about connector solder joints. The goal in answering these questions is to provide a short answer that addresses the main issue; we don’t want to present a “mini whitepaper” for each question. Of course, please

contact the IPG if you have questions, need more information, etc. At what peak temperature are most SMT ovens run? DD: This is probably the most commonly asked question we receive in IPG. The answer is always the same: the peak temperature is the derivative of the solder paste that you use. Our SMT and SMT compatible through hole connectors can handle 260° C with no problems. Having said that, most of our customers run their ovens at significantly lower temperatures, usually between 235° and 245° C, for a lead-free profile. The reason most of them moderate their temperature is to make sure they are not damaging other heat sensitive components. So when we are asked that question – what is the peak temperature for SMT oven processing — our answer is to usually

consult the solder paste manufacturer and see what they recommend for their specific paste. Will my solder paste work with Samtec connectors? DD: The answer is probably yes. Our connectors are widely used, and there are many solder paste manufacturers. We use Alpha solder pastes, which are ubiquitous. Specifically, Samtec uses the following Alpha solder pastes: 1. SAC (lead-free)

a. WS-820 (Water Soluble) b. OM-338 PT (No Clean) 2. Tin-Lead a. WS-809 (Water Soluble) b. OM-5100 (No Clean)

We have many customers using many different pastes, and we try to make all of our connector devices as robust as possible, so that the connector is not the gating item in your processing endeavors. So again, the answer is

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