Electronics Forum | Wed Sep 19 21:10:16 EDT 2007 | wailiang81
Yupe, if condition keep worst, most probably will re-allocate the PCB manufacturer.
Electronics Forum | Wed Sep 19 21:13:24 EDT 2007 | wailiang81
By vision. Could you elaborate the meaning for "the advertised repeatability for your machine"?
Electronics Forum | Mon Sep 23 22:31:48 EDT 2002 | davef
Comments are: * It�s interesting, but not surprising that your time above liquidous varies around the sides of this component. * You are correct in thinking that it is better to reduce than to increase the temperature differences around the component
Electronics Forum | Thu Apr 06 00:27:42 EDT 2000 | Dean
I would check their data sheet for the particular product. Thats the range I have for Some Kester products I use... Are you seeing any slumping prior to pick-and-place? Is the bridge in the same place every time? How is your pick-and-place mounting
Electronics Forum | Wed Sep 19 21:04:57 EDT 2007 | wailiang81
Hi,davef, thanks for your concern. The condition was the pasted printed off with around 0.8~0.9mm from the land pattern. This will easy observe at QFP area. At fiducial, the stencil seens aligned accurately. Once solder bridge happend, its easy to
Electronics Forum | Tue Sep 18 19:32:49 EDT 2007 | davef
Welcome Jimmy Let's mince words to help focus on the issues. When you say "QFP area solder paste shifted," do you mean: * Paste printed on land pattern perfectly, but moves after printing. * Paste printed off the land pattern, even though the stenci
Electronics Forum | Wed Aug 09 04:16:25 EDT 2000 | Jarno Py�ri�
And little more... If you use chip components, then that 80% from pads is good stencils apertures size. But if you use fine pitch components, example QFP, then you can use apertures, 90% from pads. I hoping that you understand something abou
Electronics Forum | Wed Jan 16 15:22:29 EST 2002 | Terry Burnette
In his book titled "Manufacturing Techniques for Surface Mount Assemblies" author R.J. Klein Wassink describes the relationship between solder land dimensions, component lead coplanarity, board warpage, solder volumes, and solder paste flux wetting b
Electronics Forum | Thu Apr 06 08:31:13 EDT 2000 | D Scott
Angela Do you see this problem on other .5mm pitch devices or is it only on the QFP? Check placement height, too low or to high can cause you problems Pad co-planarity, are your boards HASL? Is your board sagging during placement(board supports) An
Electronics Forum | Wed Sep 19 09:48:38 EDT 2007 | slthomas
In addition to what DaveF said, I'd like to know if there are other parts on this pcb, and if the paste for those parts was printed accurately or not.
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