In response to your questions: * Will a polyurethane squeegee blade help? NO * Will a Pro-Flow head help? NO, but it might be a cool excuse to buy one. Unfortunately, you will look like a jerk, if you talk your boss into buying one and then he /she finds out that it doesn�t work.
Wister there�s too much surface area on the walls of your apertures and that prevents proper release of the solder paste. The approach you take to squeegee work will do nothing to affect that problem.
The problem you have is that your stencil is twice as thick as you normally would make it. So in order to deposit the same amount of paste as you would with a thinner stencil, you need to pinch your apertures to maintain the same volume relationship on the inside of your aperture. When you do that, you ruin the aspect and area ratios [check the SMTnet Archives] necessary for good paste release. As you have noticed that these numbers are so blanked-up by using a thick stencil that polishing doesn�t do blank.
Here�s some things to try: 1 Try a Type 5 paste. This is a dumb idea, but it just may allow you to avoid doing what you should do, which is #3 below. 2 Increase your printer separation speed. This is a dumb idea, but it just may allow you to avoid doing what you should do, which is #3 below. 3 Sit down with your customer, explain the problem, and request that they either * Pay for the additional cost of using the thick stencil ... OR * Get the blank otta the way and let you do yer blankin� job!!!
Your important customer is a jerk!!! [And unfortunately you have to deal with it] Your customer should describe to you the quality and performance of the product that they expect your to deliver and not interfere with your ability to deliver product. It took many years for the US military to realize that by prescribing both process and quality requirements, they were creating an untenable situation for their suppliers [but then again that appears to be the purpose of rule making bureaucracies]
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