screening adhesives

Hi There,

Could anyone please give me some pointers on screen printing non-conductive adhesives or where I could find the information avaliable. Aspects such as printing parameters, ideal stencil design and a general overview. Do already have a particular type on trial, but are open to suggestions. The adhesive is to be thermally cured with DFM in mind for future designed PCBs.

Cheers, Jack.

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| Hi There, | | Could anyone please give me some pointers on screen printing non-conductive adhesives or where I could find the information avaliable. Aspects such as printing parameters, ideal stencil design and a general overview. Do already have a particular type on trial, but are open to suggestions. The adhesive is to be thermally cured with DFM in mind for future designed PCBs. | | Cheers, Jack. | Jack,

We had some discussion's a while back with Earl Moon and co, so there should be some info in the back pages / archives. One of the best sources for this info is the glue manufacturer so use them as well. I've been doing gluse printing for a few year's now and it's a good robust process to use. Thing's I've found that are good are :- 1. Run the glue fast across the screen 35 - 40mm/sec should be the slowest, remember it's glue and sticky so your trying to shear the stuff inthe appetures from the rest of the glue. 2. USe slot's on all 0603/0805/1206 etc components , it give's you a far stronger adhesion and the glue will go slightly up the side of the component, that's good because it's strong enough not to get knocked off with out real effort. missing bottomside component's is a reall pain and is so easy to avoid. 3. When your setting up the stuff start on contact, if your stencil is designed right you should have load's of glue. 4. If your not already doing so, use metal blades in your printer, the rubber ones just wont work.

Hope this help's but if you need more info check the archives or drop me a mail and I'll see what info I have kicking around.

JohnW

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