Electronics Forum | Fri Oct 31 07:52:23 EDT 2008 | davef
For a better understanding of decoupling capacitors, look here: * http://en.wikipedia.org/wiki/Decoupling_capacitor * http://www.hottconsultants.com/techtips/decoupling.html * http://pcdandf.com/cms/content/view/3410/95/
Electronics Forum | Thu Oct 30 15:07:40 EDT 2008 | jemills
Hello I have a new 0402 pad design on a recent board were building in future. On closer look i thought the pad was a thru hole mount , but upon closer inspection the round pads are for 0402 comps. I had a discussion with the engineer and he said
Electronics Forum | Thu Oct 30 22:29:58 EDT 2008 | davef
For most applications, a nice square [or rectangle] pad works just fine. Assemblers ship boat loads of boards with these every day. It's reasonable for tight decoupling capacitor requirement applications to use round or radiused pads for components
Electronics Forum | Thu Oct 30 15:36:18 EDT 2008 | grantp
Hi, Sounds like your engineer does not know what he's doing. We have developed and built hundreds of thousands of boards with normal square pads for 0402, and we just use a 5 thou stencil with 5% reduction and it works well. Decoupling? What is tha
Electronics Forum | Thu Apr 12 09:13:41 EDT 2007 | aj
Hi all, What stencil aperture designs do you use for 0402 components? Thanks in advance for replies. aj...
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 | Tue Apr 24 02:56:12 EDT 2007 | chrispy1963
If the PCB you are using is a HASL pad finish and is a leaded assembly, we use homeplate pads with a 5 mil stencil. If the circuit has Enig finish and is PB-Free then we use 1:1 apertures with a 5 mil stencil Either method should provide no solde
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 | 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.
