Electronics Forum | Sat Feb 10 20:08:25 EST 2007 | colormaker
I just started a design where I will be placeing smt parts on both side of PCB. 50 parts on top side ranging from 0602 to SOIC8 and 4 SOIC LED's on bottom. How can I assemble with parts on both sides ? I have P&P,stensil printer, relfow and solder w
Electronics Forum | Tue Jul 07 15:02:48 EDT 2009 | snsmt
Hello everyone, I have a question regarding rework. How do you guys rework QFPs (lead free)? The only method that we are currently doing is using a heat gun. We are heating up the bottom of the PCB (approx. 2") away from the bottom of the
Electronics Forum | Wed May 22 12:00:13 EDT 2019 | gregoireg
Thanks. It starts to make sense. There is a formula at the bottom of this page: http://www.circuitinsight.com/programs/50456.html It says: Stencil Thickness = 2.64mil + 0.0831 * pitch of component in mil. for 1.13mm, that gives exactly 0.16mm. So,
Electronics Forum | Thu Mar 01 13:42:01 EST 2001 | slthomas
Let's see how this works.... http://www.freedrive.com/GetMain.asp?affiliate=10406&menuset=explorer&menuid=explorer&us=ACTIVE Click on the Sn_Pb tsunami folder (not the camera lookin' thingy) Too bad they'd already started cleanup. The slosh hit t
Electronics Forum | Wed Jun 09 12:20:26 EDT 1999 | Gang Pan
I am starting a new project which involve 3 oz copper layer with 20 mil components on the top of the board and 0.040" thick copper with D2Pak on the bottom of the board. There is anybody has experience on metal-based PCB reflow process? I guess pre
Electronics Forum | Tue Mar 16 15:34:14 EST 1999 | CHUCK B
My engineering Dept. has informed me that they want to start using pins, on an aluminum substrate in the smt process. Pins are interconnect for daughter bds. Dia. of pins 0.020" 0.040" 0.080" flat bottoms 1) Does any one know how to hold pins
Electronics Forum | Tue Oct 22 13:11:07 EDT 2002 | slthomas
After considerable hemming and hawing, we decided to drop the bomb on 'em....give us ORL0 (which we use here) AND no bottom side solder balls or belly up to the bar with some favorable Appendix B test results on their preferred flux. As usual, Mr. F
Electronics Forum | Fri Apr 08 17:23:34 EDT 2005 | KEN
Warpage factors can cause: 1. Boards can not transfer down conveyor belts or wedge at transitions. 2. May not enter into machinery due to interferences (like board clamps) 3. May fall off conveyor chain in furnace. Especially true of thin (PCMCI
Electronics Forum | Thu May 25 18:41:15 EDT 2006 | russ
How accurate is your placement machine? if it is accurate I would eval up to 25% off pad. the problem I might think you will have is errant paste or balls causing shorts if it doesn't coalesce completely. Bottom line is, if the board is good at th
Electronics Forum | Sat May 24 08:47:57 EDT 2008 | davef
Bill Our suggestion removing small QFN is: * Heat the board be from the bottom side using a convective heater. * Use a hot gas or air on the top side of the component. A good starting point is air velocity of 15 to 20 liters per minute. * Select a no
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