Electronics Forum | Fri Oct 27 09:07:33 EDT 2006 | kingfish
I have an AP25 HiE, first time using metal blades. I have found that the paste is not releasing from the metal blades whether it is fresh or old. It is intermittent at times. Any suggestions? David
Electronics Forum | Thu Jun 29 10:38:04 EDT 2000 | John Thorup
Hello Christopher I don't know if there is any kind of official standard but I can tell you that the HADCO DFM manual specifies a nominal thickness of 50-1500u" with an option for 100-1000u" and the Merix DFM manual specifies 30-200u" Our boards (fro
Electronics Forum | Mon Jan 26 08:58:05 EST 1998 | Mike McMonagle
| I have the following questions with regards to the solder printing stencil design : | 1) Is the Electro-polish process recommended for laser cut stencil ? | 2) Should the aperture walls be slanted at an angle or straight wall, i.e. trapezoidal |
Electronics Forum | Fri Jan 17 09:38:20 EST 2003 | Grant Petty
Hi, We have a BGA that uses .4mm diameter PCB pads on the BGA itself, however we have decided to use .5mm pads on the PCB, to help paste release from the stencil. Is this a bad thing, having different size pads on the PCB compared to the BGA itself
Electronics Forum | Wed Apr 27 10:47:26 EDT 2005 | HOSS
A 1:1 pad to ball diameter will cause the balls to collapse more giving you less post solder component standoff. Depending on the application of this product and required reliability, you may want to stay with the padstack being used. You may try c
Electronics Forum | Wed Aug 31 11:02:28 EDT 2005 | Jason Fullerton
We are using one BGA that has 7 mil bumps on a 20 mil pitch. We use the manufacturer's recommended pad and aperature layout, which is an 11.8 mil square overprint on a 6 mil land. At 11.8 square, you need to use a 4 mil laser cut or a 5 mil e-form st
Electronics Forum | Wed May 10 08:41:19 EDT 2006 | russ
Yes, we added some soak, we also use a 5 zone oven. We utilize a .020" x .020" pad with center to center at .042". We only get tombstones on misplacement or bad paste release now. Registration of component is key with pbfree, the parts just don't s
Electronics Forum | Thu Apr 01 16:47:23 EST 1999 | AlexO
Dan, The rationale to use laser cut stencils in my experience is based on the benefits to paste release. Laser cut stencils are "supposed" to have a smoother inner aperture wall. That, combined with the trapezoidal shape (which can be emulated with
Electronics Forum | Sat Jan 06 11:39:56 EST 2001 | Steve Thomas
On a related note, I'm wondering if any of the newer devices have any way to factor in paste not releasing from the corners, or for that matter, radiused, oval, or round apertures. We have an LSMII, and all it does it let you draw a rectangle around
Electronics Forum | Tue Jul 14 10:23:42 EDT 1998 | justin medernach
| Hi all, | We are currently having problems with a laser-cut stencil that is | electropolished and nickel plated with 9-mil openings. The paste does | not release well from the apertures. We are having to wipe after every | print. The board is fixtu
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