Electronics Forum | Sun Mar 20 15:05:28 EDT 2011 | floydf
We are preparing to run a 2-sided board with BGAs on one side and passives on the other side. We have two schools of thought on which side we should run first. One school says run the passive side first, then run the BGA side and the surface tensio
Electronics Forum | Fri Nov 30 08:35:51 EST 2007 | stepheniii
We put glue on the bottom of the board that already has the topside SMT mounted. We populate the board. We put it through a cure profile. At this stage the topside components are soldered on. The bottom side components are glued on with NO solder on
Electronics Forum | Wed Nov 28 01:28:32 EST 2007 | shy
Q1:What is the relation between component standoff and drop missing? A1:component standoff will identify either solder paste at SMT side can form the fillet at component terminal or not. Drop/missing component is totally out of the topics since i jus
Electronics Forum | Tue Oct 03 09:25:44 EDT 2006 | Brian
You might need to use a pallet that provides some shielding for the BGA that is hanging on the bottom of the board.
Electronics Forum | Tue Oct 03 13:08:39 EDT 2006 | Moby
This is an issue that we are seeing a lot! It used to be that the primary-side (component-side...top-side) had most of the active components. It was simple: reflow bottom first. Now, we are seeing both sides of the assembly having the same amount of
Electronics Forum | Thu Mar 29 15:50:35 EST 2001 | tomgervascio
We've think that with seen solder shorts under BGAs after wave soldering the boards. In addition, it seems to be related to a certain soldermask configuration over the topside BGA vias.. THere is one vendor,A, that is applying soldermask after HASL,
Electronics Forum | Wed Oct 06 09:40:49 EDT 1999 | Mark Quealy
I have an adhesive dispenser in my workcenter but I rarely use it. I've replaced this process with wavesolder pallets for bottom side PTH soldering, ocassionally gluing parts left exposed by the pallet. So I was thinking of selling the dispensing equ
Electronics Forum | Fri Aug 10 04:19:05 EDT 2001 | wister
There are lots of voids at solder joint of chips,the thickness of multilayer pcb is 3.2mm,top side have lots of chip component and bottom side has several BGA and QFPs.For top side profile,the preheat time is about 100s,soak time is about 75s,time ov
Electronics Forum | Mon Sep 21 20:45:55 EDT 2009 | davef
10.4. Pre-Cure Examination. Immediately after material application, the uncured conformal coating shall be examined for: a. Bubbles and Air Entrapments. These defects shall be broken by vacuum, with a sharp probe, or other appropriate tools. b. Bridg
Electronics Forum | Mon Jun 14 09:16:58 EDT 1999 | Adam Pratt
| | | | | Hello all! | | | | | Recently we got a problem about the Funtional test. Some boards passed tests by using the auto-fixture(vacuum), but failed by using manual test fixture(need to plug CPU, DIMM etc.). The error symptom is no picture. We d
