Electronics Forum | Fri Jan 24 08:14:24 EST 2014 | davem
m_imtiaz, Over the last 15 years or so I've found that using the stencil foil thickness +2mils/-0mils has worked very well. For example, if you have a 5mil stencil thickness your upper control limit would be 7mils and your lower control limit would
Electronics Forum | Fri Jan 28 04:03:51 EST 2011 | grahamcooper22
Print then dispense in the areas you need extra paste. Why can you not use a stencil which has areas etched away around component patterns to thin the stencil down....for example a 150 micron thick stencil etched to 120 or 100 microns in specific are
Electronics Forum | Thu Apr 29 17:35:17 EDT 2004 | Shinmoto
Hi there, We place FBGA packages on a lot of our memory modules. Our stencils have .013" square apertures and a .005" foil thickness. We are using a type 4 paste from Senju Comtek. The price difference is not that significant and readily available
Electronics Forum | Tue Sep 22 10:29:18 EDT 2009 | stepheniii
To how many decimal places? Do you want to have a factor for different screen printer operators? There is no such formula and I doubt there ever will be one with any real accuracy. The stencil house might be able to tell you the total area of the
Electronics Forum | Mon Apr 12 15:52:12 EDT 2004 | wgaffubar
I am using Indium 92J type 4 solder paste due to a BGA site with .008" pads and stencil opening of .009" square and .005" stencil thickness. When I try the type 3 we get insuffecient print. The aspect ratio tells me that I should be using a type 4. T
Electronics Forum | Fri May 21 15:50:41 EDT 1999 | John Thorup
We are running a number of boards with 8-10 25 mil PQFPs on board. Our process is mature with at least 3 years experiance and statistically few opens on the QFPs. Our beloved purchasing department has chased the almighty $ and changed FAB vendors
Electronics Forum | Wed Sep 19 11:50:02 EDT 2007 | stepheniii
nevermind misread the post. But if the silkscreen is too thick, can you switch to another PCB manufacturer?
Electronics Forum | Wed Apr 10 11:45:08 EDT 2002 | mwoodall
We measure the thickness of solder paste printed onto PCBs as a control of the printing process. Generally 6 thou stencils are used and give between 6.2 and 6.8 thou. What thicknesses do other users get? Cheers! Mark
Electronics Forum | Fri Oct 27 11:34:30 EDT 2000 | Steve A
Wister, I agree with the other comments as far as challenging the customer, and minding proper height/width or better yet area aspect ratios. Let's assume you need to go with a .012" stencil for arguments sake. Talk to your stencil supplier about h
Electronics Forum | Wed Nov 01 11:31:39 EST 2000 | Fraser
Is it possible you could simply over print to achieve the same paste volume? Supply me the numbers and I will do the calculation for you. Cheers
