OSP: A Case Study

Q: Can I re-apply OSP if I strip it off the copper pads?

A: Yes of course you can. You need to make sure that there is no corrosion on the pad itself. The re application of OSP is a simple process and it attracts itself to the copper pad.

Q: I know I must wash my misprints; can I just have the thickness of OSP increased knowing this?

A: No, you cannot. What will happen is, you will put more OSP on your copper pad. It can harden, it can crack, and it could have some time of reaction with the reflow process and the solder paste that you place on top of the component.

Q: Is OSP easy to damage?

A: No, it is not, its integrity can be affected though. We always stress it is very important to wear gloves and maintain a clean working environment. Fingerprints, oils, sweat, cannot damage it but can affect the integrity.

Q: Do I need to be concerned with my solder paste and flux for compatibility with an OSP?

A: Absolutely. You should be running testing before you pick a specific OSP and before you pick a solder paste or flux, to make sure you have compatibility between those two products, and that you are getting the best bond that you can between the solder pad and component.