Electronics Forum | Wed Jul 30 00:05:05 EDT 2003 | praveen
Hi, I am observing warpage in the PBGA during reflow in rework machine.Reflow profile is std. (Peak temp is 214 deg C using 63/37 paste). Please advise what should be the gap between the nozzle and the BGA body during reflow process in SRT BGA rework
Electronics Forum | Thu Jul 31 09:03:36 EDT 2003 | russ
Are you baking the parts prior to installation? I have found that this will help in some cases. Russ
Electronics Forum | Thu Jul 31 12:08:12 EDT 2003 | Kris
Hi, Are you printing the paste uniformly ?
Electronics Forum | Thu Jul 31 21:22:57 EDT 2003 | praveen
Yes the paste printing is uniform. I have not tried out paste flux yet.
Electronics Forum | Wed Jul 30 23:16:01 EDT 2003 | praveen
The profile is enclosed.The PBGA is 37x37 mm.I am keeping the gap about 4-5 mm.The profile meets the solder paste spec.Peak temp is 211 deg C,Above melting point 77 sec. rate of heating
Electronics Forum | Thu Jul 31 21:21:54 EDT 2003 | praveen
Yes we are baking the boards and the BGA. Using a CDM material pallet to hold the PCB as clamping is a problem without that.
Electronics Forum | Thu Jul 31 15:29:25 EDT 2003 | bcceng
A couple of things you can look into 1. The proper bottom pre-heat of board. If you are applying only direct hot air to BGA without preheating can cause BGA's to warp and collapse un-even. 2. Moisture on you BGA's. If BGA's were not properly packa
Electronics Forum | Mon Aug 04 17:35:08 EDT 2003 | Dean
If you lay a flat edge on the PBGA, it is visibly warped? How much of a warp? 0.001, 0.010, 0.050 what? What is your pcb temperature just prior to entering the spike process (zone or step or what ever you call it)? Is it between 165 and 175 C?
Electronics Forum | Wed Jul 30 22:37:15 EDT 2003 | Dean
I have been using a srt-1000 since 98. My guess is your heating up the part too fast. What is your heating rate (deg. C per second)? PBGA's do warp. Your profile should mimic your smt process (assuming you have no warping there). Also, check wit
Electronics Forum | Tue Jul 11 02:58:22 EDT 2000 | RAIN
Hi, Does anyone can teach me how to choice x-ray system & rework station? Help will highly appreciated. Sincerely, Rain
