We have a line using the DEK Pump Print process. We use a 3mm plastic stencil and print adhesive through it. The adhesive we use is Heraeus 955. We've struggled with adhesive contaminating the pads of our smaller components. The deposit isn't on the pad, and there is no visible squeeze out, but in changing the stencil to move the glue as far away as possible, the problem goes away. Recent constraints have put me back into this again.
Can anyone recommend a good adhesive for this process? Has anyone experienced anything similar? It seems like a layer of "stuff" may be squeezing out from the holes, but it isn't easy to detect.
Not to put Heraeus down - but we experienced the same thing from time to time. We finally found out it was the humidity in building. The higher humidity would cause the bleed out of this adhesive. We switched to Loctite and the problem went away.