Electronics Forum | Tue Dec 04 06:16:50 EST 2001 | Andy
For conventional QFP device, what is the optimun height between lead and pad? 50 microns or 100 microns? What is the factor affecting this height?
Electronics Forum | Wed Nov 12 04:34:17 EST 2008 | kywl
Hi all, Assuming that i were to design a PCB and there are multiple components, what is the minimum spacing required to ensure that i won't have problems in my SMT process later on? Also, is there a minimum component stand-off height spec as well?
Electronics Forum | Thu Nov 13 22:20:48 EST 2008 | davef
For your pad layout and spacing between components, look here: http://portal.ipc.org/Purchase/ProductDetail.aspx?Product_code=77b562c1-b8f8-db11-8a6a-005056875b22 For your standoff height in SMT, we do not concern ourselves with standoff height. It
Electronics Forum | Fri Nov 14 03:41:26 EST 2008 | kywl
For your pad layout and spacing between > components, look here: _a class=roll > href="http://portal.ipc.org/Purchase/ProductDetail > .aspx?Product_code=77b562c1-b8f8-db11-8a6a-0050568 > 75b22" > target="_blank"_http://portal.ipc.org/Purchase/Pr
Electronics Forum | Fri Apr 20 16:05:17 EDT 2001 | gcs
We always reduce side to side, EXAMPLE: 12 mil width reduced to .010". Do you guys check viscosity ? Also maybe your guys are appling to much pressure on the sqweegee blades.
Electronics Forum | Fri Nov 14 07:32:24 EST 2008 | davef
Yes, courtyard gives you the space requirement of a component. Sometimes, the working space of a rework tool takes precidence, though.
Electronics Forum | Fri Apr 20 11:05:23 EDT 2001 | gcs
Just a bullet! My results are, .005" stencil thickness should measure between .0055" - .006" if your pressure is correct, metal blades and snap-off is set up correctly. Do you have aperture reductions at the QFP locations "typicial industry standard
Electronics Forum | Tue Dec 04 09:48:43 EST 2001 | davef
Defining the thickness of solder between the lead and the pad, J-001 states "Properly wetted fillet shall be evident." J-001 is available from http://www.ipc.org. Factors that affect this are: * Amount and composition of solder * Amount and compo
Electronics Forum | Fri Apr 20 15:27:00 EDT 2001 | jimlew
We do some aperture reductions - but it's not the 10% i'm accustomed to. Looks like it should be more than we currently do (I think we do 10% of length, but no width). Don't think we have a slumping problem, and we're not doing snap-off, only contact
Electronics Forum | Fri Apr 20 08:41:56 EDT 2001 | jimlew
For those of you out there, like myself who are still using 2-d to measure paste ht, I have 2 questions. 1. Typically, what tolerance are you applying to your ht? +- 1 mil, or what? 2. Are you using metal squeegees, and if so, have you found that squ