Electronics Forum | Thu Dec 12 09:21:42 EST 2002 | blnorman
What we did: *Slump-dot diameter and height as a function of time *Print Speed-Vary speed, measure slump and missing/defects *Green Strength-We quantifiably measured tack vs time and we placed components and measure skew by SVS *Cure profile sensitiv
Electronics Forum | Wed Dec 18 12:49:04 EST 2002 | Mike F
I've used rice, too. The trick is to make the bag big enough to hold down the part or parts, but not so big it interferes with the top side heating of the parts around it. I've never actually used lead or steel shot, the heaviest fill material I ever
Electronics Forum | Wed Dec 18 15:38:59 EST 2002 | swagner
I have had a similar problem in the past, since I have never worked with a semiautomatic printer there could be a few things I recommend that will not work for you. 1. Make absolutly sure that you have proper support under all of the BGA's. 2. Print
Electronics Forum | Sun Dec 22 06:00:54 EST 2002 | Mark
Hi: Your stencil specs are good; Did you check the stencil thickness? It would be worth a ck since there may be an error from the stencil mfr If the paste is not releasing with good stencil specs, these are possible causes: 1 The paste isn't tou
Electronics Forum | Mon Jan 13 21:52:16 EST 2003 | davef
Haaaaaa!!!! You contractors get all the fun don't ya??? Consider: * Replacing the balls on the corners of the devices with balls composed of a "hard solder", yano something like 90/10. * Shimming to prevent excessive collapse of a heavy BGA during
Electronics Forum | Fri Jan 17 21:17:18 EST 2003 | Grant Petty
Hi, Our paste release problems have been solved, and we worked on the stencil, and things are working well now. However this board was designed before we knew what was going on, and we thought a little more size on the pads would be a big help. Is
Electronics Forum | Mon Jan 20 17:42:45 EST 2003 | jonfox
Double check the data sheets for your paste. Just as an example, ou Indium paste has a recommendation for the Heating, Liquidus, and Cooling stagees of reflow. They recommend a linear ramp up of 0.5 to 1.0 degree C. In the Liquidus stage, a peak t
Electronics Forum | Fri Jan 24 16:46:21 EST 2003 | MA/NY DDave
Hi, Distance Engineering is always difficult. I am guessing that the old machine and process ran wonderfully / acceptable. If you still have the old machine, how about running an empty board through it and then the new machine. Without flux observ
Electronics Forum | Sat Jan 25 20:17:40 EST 2003 | ramanandkini
We are soldering a 8 pin TTL chip on to a CEM1 board that has a hot air level soldering. We use no clean soler paste for the reflow process. Now the customer wants us to clean since he is afraid of flux attracting the dust. We have some SMT LEDs that
Electronics Forum | Mon Jan 27 12:27:03 EST 2003 | ksfacinelli
We have an assembly that requires a number of high density connectors to be placed after SMD. The process will not allow a normal wave solder setup due to the population of SMD comps. We cannot use a selective solder pallet due to profiles. We are