Adhesive dispension

We have customer requested machine dispension on adhesive of solder side components, however we are currently using stencil printing for adhesive. Have anyone evaluated and compared on dispension and screen printing of adhesive before? Thanks!

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| We have customer requested machine dispension on adhesive of solder side components, however we are currently using stencil printing for adhesive. Have anyone evaluated and compared on dispension and screen printing of adhesive before? | Thanks! | Hey DS, give the customer what they want.

When we print adhesive on the second side, it's just to hold the components in-place during wave soldering and maybe PTH insetion. After waving, the solder holds them in-place and makes the electrical connection. Then the adhesive is about as useful as ... Not matter how it's put on the board. We can usually tell if a component is missing because there's big red blob of adhesive sitting there with no component trying to cover the blop up. So, I'm uncertain about the end item benefit of dispensing over printing adhesives. We print 'cause it cheaper, faster, and (we believe) produces an equivalent product.

Good luck

Dave F

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To me, customer always has a reason...

That reason may be the board requiring "smt primary" -> "DIP, VCD" -> "smt secondary" type of process flow. In that case, dispensing becomes a must. Dispensing needs less setup than printing, but takes longer. So, for a prototype manufacturer, dispensing becomes the best choice. Sometimes a machine dispenses glue and places the part simultaneously. Some people have a dedicated glue dispenser which is faster and more capable. When you have SOICs on the secondary side, you can dispense larger/higher glue dots while dispensing smaller ones for the chip resistors/caps. The last but not least; dispensing is a life saver during double sided reflow, if any top side parts need to be glued.

Good luck...

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