Electronics Forum | Fri Nov 22 08:57:56 EST 2002 | davef
Q1: What do you mean by "if the board is manufactured properly"? A2: If the epoxy is noy cured prooperly, for instance, the copper will not be well attached to the glass. So, peel strength will be lower. Q2: I don't believe that the peel off/or lif
Electronics Forum | Fri Dec 13 18:35:48 EST 2002 | successmani
Thank you friends for your discussion Regarding the reason behind using Solid disk or donut fiducials.Still I am understanding clearly the reson behind using Solid disk or donut fiducial shape. In all the above discussions we had we did not discuss a
Electronics Forum | Fri Dec 13 12:56:57 EST 2002 | kmcneeley
I've seen this type of problem before. You need to get on your bare board vendors. It's a process problem for them. When you add the heat in reflow or wave solder the vias open. I'd get the vendor involved and reject the bare boards. There is still a
Electronics Forum | Mon Dec 16 10:54:48 EST 2002 | davef
Knee of barrel and pad crack: Caused by thermal stress during soldering, because epoxy expands in the "z" 3X more than "x" or "y" which are restricted by the fiber. Related to: * Design of pads too large relative to hole diameter * Temperature at o
Electronics Forum | Mon Dec 16 15:10:56 EST 2002 | Randy Villeneuve
We do not bake any of our boards prior to wave solder. If we did we would have one heck of a large oven. I would assume you are concerned about moisture sensitive components. In most cases your top side parts should only get to 80 degrees centigarde
Electronics Forum | Tue Dec 17 09:48:44 EST 2002 | russ
Temps are related to the components/PCBs being soldered. I am not aware of any Industry standard. If you are soldering flex circuits, .020" boards etc.. We use 500 deg tips a little thicker PCB/lead we go to 600, and so on. We never exceed 800 in a
Electronics Forum | Mon Dec 23 17:36:23 EST 2002 | davef
Periodically, we get ahead of ourselves and find that we have fabricated boards that require jumpers and other modications. Alternatives are: * Add 'white wire' jumpers and mod the components as third ops * Print, cure, and seal 'jumpers' of epoxy i
Electronics Forum | Wed Jan 15 11:42:57 EST 2003 | burb1999
we have recently been trying silver composition on our pads with our PCB boards. I am wondering what if any characteristics are different from tin etc... I have found with profiling the board it to be about the same temps. but getting granular looki
Electronics Forum | Mon Feb 03 05:02:49 EST 2003 | Eugene
Hi all. One of our customers recently asked us during an audit of our PCBA rework line if we have a limit for the total number of reworks/repairs that can be done on one PCBA. We specify 3x maximum on one location of a major part (LSI for example). B
Electronics Forum | Tue Feb 04 15:45:16 EST 2003 | adlsmt
If you are physically breaking the boards apart and not using a depanelizer you will always have this problem. I have a machine shop that can make you one for about $3,000.00. You can buy one for around $5K new. Cab,FKN and some others make them. Be
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