Case Study Series

Stencil Printing Optimization.
– Debbie Carboni

Q: Why does a Vacuum always improve Yields?

A: We have done quite a bit of research in this area. When you end in a dry wipe, you push those solder balls to apertures, causing potential defects, lowering the number of prints you can achieve.

Q: Can Nano coating improve Yields without Engineered Solvents?

A: They can improve the yields, but they will not do away with them. By using Nano coating and an engineered solvent, you can take out some of the variation in your process and see more consistency in your wipes.

Q: Do you have to adjust the solvent volume for each solvent?

A: By optimizing and setting up your solvent, you can further optimize your whole process and maybe even improve and increase the number of prints between wipes.

Q: How come IPA cost is more than Engineered Solvents?

A: IPA evaporates at such a quick rate, and depending on how that fluid delivery system is, it may have an open trough, which allows that extra material to be exposed to the air, and it’s evaporating off and must maintain a certain level. Another way it adds to your cost is that it takes more material to get you even a somewhat acceptable wipe. You might find that the flux is often smeared on the bottom side of the Stencil itself.