Electronics Forum | Fri Dec 20 11:32:51 EST 2002 | D. Adams
Check your stencil apertures making sure they are trapazoidal and smooth. I have hadjobs where the laser stencil was improperly cut (poor laser settings leaving a rough hole even after electropolish. Be sure to specify a .0005 trapazoid in your ste
Electronics Forum | Wed Dec 18 15:38:59 EST 2002 | swagner
I have had a similar problem in the past, since I have never worked with a semiautomatic printer there could be a few things I recommend that will not work for you. 1. Make absolutly sure that you have proper support under all of the BGA's. 2. Print
Electronics Forum | Thu Dec 19 14:29:03 EST 2002 | mark
It sounds like the stencil wasn't polished. Most stencil sources that only offer laser cut stencils do not have the electro polishing chemistry because they don't want to deal with the waste treatment issues. I suggest you verify that the stencil is
Electronics Forum | Thu Dec 19 14:29:06 EST 2002 | mark
It sounds like the stencil wasn't polished. Most stencil sources that only offer laser cut stencils do not have the electro polishing chemistry because they don't want to deal with the waste treatment issues. I suggest you verify that the stencil is
Electronics Forum | Fri Dec 20 04:07:25 EST 2002 | Roger
Although everything that has been said earlier is sound advice for achieving good printing results, I strongly believe your problem is your manual printer and its inability to accurately control the speed at which the PCB separates from the stencil a
Electronics Forum | Sun Dec 22 11:02:44 EST 2002 | valuems
I am breaking a cardinal rule with this reply, but here goes. I believe almost every one is missing this one. Roger has hit the nail on the head. The gentleman is useing a clam shell printer and when the stencil lifts (too fast) and at the angle o
Electronics Forum | Tue Dec 17 20:25:13 EST 2002 | iman
Check : 1) design aspect ratio / are ratio required to fabricate the stencil you r using. 2) check if the stencil maker is using your checked aspect ratio / area ratio? if not the same, what are they using? any QA report confirming actual dimension
Electronics Forum | Sat Nov 27 10:16:38 EST 1999 | Steve Thomas
The new design resulted in much better release characteristics. We are quite satisfied. By the way, he says he can cut dead nuts 90 degree walls on the apertures, or traps. I didn't ask what the wall angle was, nor have I seen any recommendations,
Electronics Forum | Sun Nov 21 13:48:16 EST 1999 | Steve Thomas
We're going to 5 mil foil from 6 mil, with a 10 mil aperture, radiused corners. Supposedly going to traps. from right angles, but who knows? We've got temp. controlled at ~73F, but no RH control. We are going to also try out a more humidity toleran
Electronics Forum | Sun Nov 07 10:54:21 EST 1999 | Steve Thomas
We're looking at redesigning our stencils to facilitate better (well, it's pretty much non-existant, so any improvement is a big leap) release from fine pitch apertures. Currently we have perpendicular walled laser cut apertures. We'll be having
