Electronics Forum | Wed Jan 10 20:06:43 EST 2007 | SSS
I've been assembling thousands of boards for dozens of customers over the past 5 years with 0402 chip components. 85% can happen very easily even with newer equipment. Defect challanges with 0402 packages is almost always tombstoning. Capacitors abou
Electronics Forum | Thu Jun 13 11:27:25 EDT 2002 | davef
>*Changing paste >EricD: Yes we are considering that as a point. Because I believe the paste we are using are in syringe packaged and designed for dispensing. We are using an Indium SMQ75 paste and current application naturally is stencil printing.
Electronics Forum | Wed May 10 00:27:46 EDT 2006 | Chris
Russ, By a longer profile you mean a more even slope across the entire profile. Unfortunately I only have a 5 zone oven that is fairly short. How many heated zones are you using? Did you shrink the 0402 pad design and leave less pad exposed out a
Electronics Forum | Thu Jun 01 08:39:36 EDT 2006 | russ
IPC a 610 has this info. An 0402 however mat require more solder than what IPC states (basically evidence of wetted fillet for class2). more paste = more flux = better wetting. Why don't you tell us what pad sizes and layout you have and stencil t
Electronics Forum | Wed Apr 12 21:33:27 EDT 2000 | Micah Newcomb
Billy and Chris have a good point, pad size and geometry will affect proper aperture size and geometry and could result in tombstoning. Also I have seen chips which require special pastes but I have never found this to be the cause of tombstoning, in
Electronics Forum | Thu Apr 11 05:47:21 EDT 2002 | ianchan
Hi everyone, Does anyone have experience and applications knowledge, to help recommend a singulation machine? for depanelization process of a : 1) 0.65mm thickness PCBA, with 0603/0402 SMD, 2) with materials composition makeup of a 1.5oz copper,
Electronics Forum | Wed Feb 09 12:31:54 EST 2005 | russ
We are not doing this right at the moment but I have done it with great success. Of cource it depends on your pad layout we have a 20 mil gap in between pads, we printed at 10 mil wide with a 5mil stencil. I will try to find the glue we used, I kno
Electronics Forum | Tue Feb 22 10:44:12 EST 2005 | Dougs
when you talk about stencil design, what would you recommend for aperture size on fine pitch if the customer insists on hasl finish on fine pitch devices? i usually use a 10% reduction on everything we have been using ( 16mil pitch and upwards and 0
Electronics Forum | Fri Jan 16 07:06:47 EST 2004 | Mika
Component manufacturer often have recommendation for pad layout and process setup. This should be used as a guideline to help You to set up the process. Exactly what type of component is this, uBGA? We populate 64 I/O uBGA's on our pcb's with 0.3 mm
Electronics Forum | Thu Dec 24 01:38:36 EST 1998 | Chris Grendler
I need advice on a pad design which several other engineers whom I work with would like to try. I think it is an utterly crazy but I can't seem to convince them differently. My current 0402 chip pad sizes on alumina and FR4 substrates are .022"X.