Electronics Forum | Mon Feb 21 11:22:21 EST 2000 | K. Ckak
Hi Kurt, I agree with Dave F. I had exact same problem with PBGA placement. We requested our PCB vendor to plug/tent via (button printing) after HASL with SR1000 which worked well in the long run. There are couple of failure modes associated wit
Electronics Forum | Mon Apr 02 20:47:22 EDT 2001 | davef
Cuppla questions for ya ... Where are the shorts [above the mask or between the mask and the laminate]? On the board, what material is between the copper traces and the mask? What type of solder mask(s) used by your suppliers? What are they using
Electronics Forum | Fri Nov 14 17:21:17 EST 2008 | cisridn
Plugging the holes with temporary solder mask helped some, but once the solder starts to reflow, the fumes from the flux pushed the solder mask out. What I ended up doing in addition to using the temporary solder mask was covering the areas of pcb w
Electronics Forum | Mon Jun 29 16:53:02 EDT 2009 | Geo
I need some help in setting straight QA which owns our ESD Procedures. 1. Is the limmiting resistor for personel safety or to slow down ESD discharge? Everything I have read indicates it is for personnel safety. 2. Is it an ESD violation to have
Electronics Forum | Wed Aug 09 22:11:46 EDT 2000 | Dave F
Mark: The best routing of test vias for BGAs is to keep them far away from the device. We route test pads for the outer two rows of balls and use vias as test pads for the inner rows of balls. Your bottom-side layout is fine. Yes, on the top-side
Electronics Forum | Tue Nov 30 16:50:20 EST 1999 | Dave F
Greg: It depends on the specifics of the flux you are using. You didn�t say. Generally, using a: � "No-clean flux" should create no flux entrapment problems for most applications. � RMA with 25% or more solids as a "no-clean" should create no flu
Electronics Forum | Fri Aug 16 10:00:03 EDT 2002 | davef
You have a very bad situation. It�s tough for the gas, flux material, er whatever to escape when the BGA is sitting on top of it and the blind via is blocking it from the other side. Obviously the vias should have been: * Placed on the edge of the
Electronics Forum | Sat Jun 28 22:52:34 EDT 2003 | ramanandkini
We have an Electromechanical assembly (clock) that has a step motor on the board. This electromechanical assembly is assembled in a screw less plastic moulded casing. The plastic casing is neither air tight nor water proof. The board is with SMOBC+ H
Electronics Forum | Fri Oct 08 09:43:27 EDT 2004 | davef
First, don't get too excited about the thermal capabilities of conductive epoxy. An epoxy like DuPont CB-100 increases the amount of heat conducted through the barrel, but many over estimate what it can do. Calculations show for a 0.020" drilled
Electronics Forum | Sun Feb 04 15:06:20 EST 2007 | Scotty
Profile should have a longer cool soak. Verify as was mentioned all pin/fixture support through out the entire process. Print, Place, pre reflow hand load, post reflow, carriers, ICT, Depanel and FCT. Conformal Coated or Potted? Mylars work well for
