Dave,
Thanks for the interest.
Basically, we looked at this project as a straight swap, i.e. printing the glue on the PCB using a Dek screen printer instead of our current method of dispensing glue using a Camalot dispensing machine. For the PCB we trialled, there was no solder paste, only glued bottom side SMD components and thru-hole top side components; the PCB was wave soldered when all of these parts had been fitted.
We currently run our glue dispenser (a Camalot 3800) at about 12000 dots per hour. The board we trialled had 1100 individual glue dots, so it would take 5� mins to process on the Camalot. We reduced this cycle time to 30 secs by printing.
For virtually all of our boards which go through the Camalot machine, the glue cycle time currently exceeds the SMD placement cycle time by about 10 - 20%. Therefore, by printing glue we would see a significant improvement in placement efficiency.
Set up times for the two processes are roughly the same, although the glue stencil is notoriously difficult to clean afterwards. We are soon to invest in a stencil spray cleaner which will make this task a lot easier.
Dek Precision Screen Division in the UK have been instrumental in driving this technology. Let me know if you require any further information.
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