Electronics Forum | Fri Jul 13 14:56:01 EDT 2001 | stevenamacdonald
One of our board vendors recently switched their stencil design to home plate apertures. Since the change the quality and yield of their PCB's has went south, Could this process change be the cause?
Electronics Forum | Sun Oct 28 08:32:47 EDT 2007 | davef
With a 7 thou stencil, we'd go 1 to 1. So for a more typical 6 thou stencil, we'd bump the aperture area by 1.15, maybe 1.2. We make no distinctions between 'innies' and 'outies'. Are you talking about castellations on land grid devices [ie, BCC�, L
Electronics Forum | Thu Apr 12 09:50:51 EDT 2007 | pjc
There have been many designs of apertures for 0402, round, home plate, inverted home plate and various reduction amounts for square or rectangular apertures. What works best for a given application depends on PCB design, solder land finish, stencil t
Electronics Forum | Thu Apr 12 10:01:43 EDT 2007 | realchunks
Hi aj, Pete is right, there are several variables that can affect your quality when it comes to stencil design. A good idea is to have a stencil made with various designs incorporated into it. A lot of engineers like the reverse homeplate design.
Electronics Forum | Sat Apr 14 04:33:44 EDT 2007 | aj
the footprint is IPC standard which I have found to be less forgiving than the Jedec one for tombstoning. Enig finish - 5 thou stencil. We have historically used homeplate design but I am leaning towards 1:1. Leadfree application. aj...
Electronics Forum | Tue Apr 17 17:30:09 EDT 2007 | jaimebc
Our experience with leaded paste and SAC305, for 0402's, has been positive with the following stencil designs: 1.- 5 mil thickness. 2.- Home plate design. Hope it helps.
Electronics Forum | Fri Jul 13 19:08:55 EDT 2001 | mparker
Home plate apertures are designed to reduce or eliminate solder balls that occur when placing a chip and reflow of the solder. This aperture type is usually desired when processing with a "no-clean" solder paste. The design of the aperture is usually
Electronics Forum | Thu Mar 06 10:57:28 EST 2003 | Mark
What are the recommended stencil apertures for a TSOP40. Lead pitch 0.48mm & lead width 0.21mm. And direction of squeegee print over the aperture? Recommended Stencil thickness? Recommended aperture reductions? Recommended pcb pad sizes? Recommended
Electronics Forum | Fri Mar 07 14:09:16 EST 2003 | davef
Q1: What are the recommended stencil apertures for a TSOP40. Lead pitch 0.48mm & lead width 0.21mm. A1: We've talked about this previously here on SMTnet, for instance check the fine SMTnet Archives: http://www.smtnet.com//forums/index.cfm?fuseactio
Electronics Forum | Fri Mar 07 21:02:21 EST 2003 | neil
When printing below .5mm pitch, the recommended stencil thickness is 5Thou, laser cut. Do not use any reduction and ensure wherever possible the pad to space ration is 1:1, the length of the pad is not as important as the gap between adjacent pads. T
.gif)
winsouce.jpg)
.gif)