Electronics Forum | Wed Jan 17 15:13:24 EST 2007 | jaime39
When placing the part to be reflow try applying heat to the board from the secondary side until the primary side has a temperature of about 130 degrees celcius. Following this procedure it should minimize the heat exposure of the part being soldered.
Electronics Forum | Wed Feb 07 16:20:46 EST 2007 | davef
Bismuth is a low-melting metal with poor mechanical properties; if you melt the bismuth wire into a standard tin-lead solder joint, then the bismuth alloys with the solder, and forms a material that will crumble if you scrape it with your fingernail.
Electronics Forum | Thu Mar 01 23:15:28 EST 2007 | jmelson
You shouldn't be worrying about "impedance" on a DC relay. Just measure the resistance with a Voltmeter/Ohmmeter. If you need to know the current draw, it will be 24/resistance The impedance of an AC relay changes as the armature moves from the "off
Electronics Forum | Mon Mar 12 11:53:52 EDT 2007 | realchunks
Hi Coop, Sounds like you are having top side wetting issues. Generally this is flux related, but with a foam fluxer, I'd kinda doubt it's the fluxer. Could be heat related as well. Try slowing the conveyor speed to verify. Long leads - hmmmmm.
Electronics Forum | Thu Mar 29 13:29:08 EDT 2007 | JD
Ewwww metal mini stencils? Try http://www.circuitmedic.com/products/stencils.shtml We use their flextac stencils all the time and they work perfect. You can get a couple uses out of each of them if youre careful too. Just line it up under a scope and
Electronics Forum | Thu Apr 05 08:59:43 EDT 2007 | rgduval
Dave, I've seen some instances of solder as you mentioned "painted" over the joint. Almost looks like a seam between the added solder and the originally waved on solder. Typically, I've seen that in the past from an incomplete solder joint. One w
Electronics Forum | Thu Apr 05 09:18:14 EDT 2007 | pjc
Please note that pin holes and blow holes are not always defects. The latest IPC 610A Rev D workmanship standard has them as process indicators- depending on Class. I don't have the document handly while writing this. It would be good to look that up
Electronics Forum | Sat May 05 18:18:22 EDT 2007 | colormaker
I am using a Novastar 12S solder wave with Kester water soluable fux 22-2425. I have used this for years without problems on an old Hollis machine. Just started using the Novastar and after fine tuning I get itermitten bridging on the front of the P
Electronics Forum | Fri May 25 00:31:07 EDT 2007 | Mike Konrad
Never use a water softener for defluxing. They add sodium to the water which is bad for boards. The white residue may be flux. If that's the case, either the dishwasher is not powerful enough or the wash water is not hot enough. Another possibili
Electronics Forum | Tue May 29 15:10:30 EDT 2007 | realchunks
Hi Jerry, Sounds like the white stuff is flux. I doubt if 4 pcb mfgers could be undercuring all at once. Good point though. Since you changed washers and now have the problem - it's your new washer. Can you bring back the old one to make sure?
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