Electronics Forum | Mon Jun 25 20:50:33 EDT 2001 | davef
If your solder paste has forsaken the pads and gone to all the work of climbing the leads, it�s because the leads are much warmer than the pads. Some like it hot!!! We talked about this on SMTnet within the past 6 months. Please check the archives
Electronics Forum | Sat Jul 21 09:27:45 EDT 2001 | davef
No. There's nothing fancy. You need enough solder on the exposed pad for a good thermal connection, but not so much to lift the comonent off the TSSOP pads. We reduce the aperture for the pad, dunno 85%, with four windows [but it doesn't matter ho
Electronics Forum | Wed Aug 01 11:11:38 EDT 2001 | JohnW
hi Folk's, Ok so I'm looking for some thoughts on Conductive Epoxy's. I'm trying to replace a material that i can place between a QFP and the PCB to transfer heat from the component to the PCB. The material has to be able to be injected thro' a hole
Electronics Forum | Wed Aug 01 17:17:15 EDT 2001 | mparker
Since you are restricting the outward flow of injected material to basically mimic the package dimensions that would force you to design some sort of coffer dam beneath the part to contain the injected material. One alternative to your quest could b
Electronics Forum | Mon Aug 06 16:08:57 EDT 2001 | seand
Hello Again John, Are you injecting a like material currently? How are you doing this with your current process? Is this material being used specifically because the customer identified it as such? If this is not a current process for you, how do
Electronics Forum | Thu Jan 20 15:11:26 EST 2000 | Russ
I tested out the OK unit and found it to be a "down and dirty" rework machine that will do BGAs if demeanding thermal requirements are not needed. My largest concern was the lack of bottom side preheat. I have recently purchased the Air-Vac DRS24 a
Electronics Forum | Wed Jan 05 14:21:27 EST 2000 | Glenn Burson
I have the opportunity to pick up a used 1998 Heller 1900WN reflow. I have no experience working with Heller reflows, nor have I heard much about them, so I don't know if they are good quality machines or not. I have concerns about issues such as z
Electronics Forum | Fri Dec 17 06:11:33 EST 1999 | Christopher Lampron
Henry, TNT makes some good points. I have also found that the use of a 2% silver solder paste (provided that it's allowable) can help reduce the occurance. You may want to run a thermal profile on the PCB is question. Is the board thermaly equalized
Electronics Forum | Fri Dec 17 08:45:26 EST 1999 | Wolfgang Busko
Hi Henry, amoung all things that cause this funny effect the most effective measures in my experience were good PCB design (pads and equal thermal conditions for both sides of the components), placement accuracy and profiling, profiling, profiling. L
Electronics Forum | Tue Nov 02 11:44:54 EST 1999 | Wolfgang Busko
Hi Pat, is the soldering Ok when you solder them by hand ? We use some larger ferrite beads with no problems in reflow but I must say that we use a vapour phase and only max 5 parts/PCB. They do have a high thermal capacity and you use a lot of them,
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