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 | 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 15:36:18 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 | Mon Nov 30 08:39:05 EST 2015 | spoiltforchoice
http://blog.screamingcircuits.com/2010/09/smd-vs-nsmd.html such as this? Which handily also tells you what you might want to google.
Electronics Forum | Tue Apr 10 08:37:36 EDT 2018 | davef
Hi Steve ... I found nothing in the manufacturers "paper" to help. Comments are: * I agree. No blobs. Solder on the thermal pad should me minimized. Too much solder will float the component. Old timers used to talk about 50-80% coverage. * If you'
Electronics Forum | Tue Feb 04 17:24:07 EST 2003 | jonfox
we have some pretty tight 0402 placements and our best fix was to reduce the pad (vertically speaking) from .030x.022 to .020x.022. Fewer tombstones and the paste flows out to the edge of the pads nicely. Only difference is that we have a 6mil sten
Electronics Forum | Wed Feb 05 14:20:45 EST 2003 | Stephen
One thing that worked for me was simply rounding off the pads, making square pads into circlesfor the stencil. It worked but did seem a little strange turning squares into circles for 0603's and 0402's and turning cirlces for BGA's into squares, (bu
Electronics Forum | Thu Jul 21 09:43:10 EDT 2005 | davef
We agree with Russ. The solderballs are probably the result of printing too much paste on the board. In designing your 5 thou thick stencil: * Aperatures for the pads should be identical to a IPC-7351 - SO8 [or worst case http://www.vishay.com/docs
Electronics Forum | Mon Apr 09 13:53:45 EDT 2018 | dleeper
I've never placed one of these before, but it looks like a poorly designed part. It has pads scattered asymmetrically around the body of the part. when it reflows this is going to apply uneven forces to the component, causing it to skew. I guess hav
