Electronics Forum | Mon Dec 18 13:00:34 EST 2006 | realchunks
Hi John, Depending on your board, it could make a difference. Copper finishes might leave that part of the pad exposed, which is a no-no in most places. Where as a HASL board prolly won't care if you pulled the print back. On the other end, over
Electronics Forum | Wed Jan 17 18:08:51 EST 2007 | John S.
We use a fairly simple system. IPC put out standards 7912A and 9261A to define opportunities. Basicly the "number of components" + "number of solder joints" = "number of opportunities." Some six sigma benchmarking studies indicated "Sigma Level" =
Electronics Forum | Tue Jan 23 14:26:12 EST 2007 | CL
Hello AR, Yes we are inspecting SMT that has been wave soldered. We are not inspecting solder on through hole components. We have actually found the solder inspector works better for wave solder SMT joints than reflowed. The system is great at ident
Electronics Forum | Fri Feb 16 06:47:38 EST 2007 | CL
vshan, We were using pallets (delmat with cavities for the flex) We put stips of double sided Kapton tape in the critical areas. The tape held up to the heat and kept the circuit flat for the QFP's and BGA's. We based our assembly process for this c
Electronics Forum | Thu Mar 01 22:21:06 EST 2007 | davef
From our notes ... An intense evaluation was completed in 1992 that involved testing of three board types [6 layer FR4, 6 layer ceramic copper thick film, and a 4 layer copper-invar-copper board] by the Navy Surface Warfare Center, Crane, IN. [Obvio
Electronics Forum | Fri Mar 16 12:48:12 EDT 2007 | Cmiller
Thats interesting, I was told by people at Assembleon that the Lightning head from Universal does not work as advertised and that they have a lot of problems in the field. I went to New York to look at it, looked great. Talked to everyone I could fin
Electronics Forum | Thu Mar 15 07:04:59 EDT 2007 | chrissieneale
Hello Just wondering if anyone has done trials on how long you can leave paste (tin-lead or pb free) on a board after you have printed it before it starts going 'off'? Thanks Chrissie FYI - have searched and found the 'pasting ahead' thread - jus
Electronics Forum | Thu Apr 05 09:17:40 EDT 2007 | itaig1
I have seen a method used where the pins on the connector are of the same materials as the thermocouple and the connector is connected via single strand wires of the same material to the PCB however the wires were spot welded to bare copper pads to r
Electronics Forum | Mon Apr 02 09:42:51 EDT 2007 | chrissieneale
Quick question for anyone - With this whole pasting and waiting thing - i've found out that the board is pasted, it sits around for a bit, then the components get placed on it. Then i thought it went into the oven BUT, it doesn't. It sits for a few
Electronics Forum | Mon Apr 23 09:37:20 EDT 2007 | davepick
Assuming you are going to build using a Leaded part on a Lead Free Process - beware of Weak Joints. I saw this at a large Multinational company - They had secondary reflow on a Top Side QFP when the PCB went over the wave. We did pull strength tests
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