## Electronics Forum: plugged and aperture (Page 1 of 14)

### 0402 pad and stencil aperture design

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/

### 0402 pad and stencil aperture design

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

### 0402 pad and stencil aperture design

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

### 0402 pad and stencil aperture design

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

### CCGA and overprinting?

Electronics Forum | Mon Oct 15 12:42:36 EDT 2001 | davef

I hate getting "roped" into math stuff, but here I go again ... Area of aperture = volume of paste / stencil thickness = {[5000 mil^3] / 5 mil} = 1000 mil^2 Side of the square aperture = Sqrt of the area = [1000 mil^2]^1/2 = 32 mil Diameter of ape

### Stencil cleanliness and inspection

Electronics Forum | Tue Jun 05 14:38:55 EDT 2001 | pteerink

You would be better served to check your print quality as you run. Any problems caused by dirty stencils ( plugged aps etc ) would show up right away as a defect. Search the forum for more on this subject. I seem to recall the same subject coming up

### via tenting and pluging

Electronics Forum | Fri Nov 03 07:28:27 EST 2006 | davef

Via filling methods are: * Tenting * Plugging * Capping * Flooding Tented Via. A via covered with dry film soldermask; the via is not filled. When tenting from both sides there may be issues with trapped air that expands during mass soldering. Plug

### CCGA and overprinting?

Electronics Forum | Fri Oct 12 09:17:12 EDT 2001 | mikecampbell

Hello, I need some advice. I want to create apertures in my stencil for a IBM CCGA. I've heard the standard is 4800 cubic mils of paste per aperture. I usually use a 5mil stencil for this type of product. There is no way I'll get enough paste wit

### Stencil cleanliness and inspection

Electronics Forum | Tue Jun 05 16:40:46 EDT 2001 | kerryn

Thanks Phil. However, my objective is to identify stencils that are not 100% clean prior to sending to inventory. I want to catch it before the solder paste has a chance to dry and harden in the apertures. Kerry