Electronics Forum | Wed Apr 28 12:10:14 EDT 2004 | paul_bmc
Are your solder balls after reflow a perfect sphere or are they oblong, like chushed. I know a heavy bga or incorrect reflow profile could cause bridging. Also too much flux paste. Sometimes what we do is brush the flux paste onto the pcb pads inst
Electronics Forum | Wed Apr 28 15:08:10 EDT 2004 | russ
This could be a long shot but here goes. I have found that if flux is applied in excess that it will actually "move the solderballs" during reflow. I have actually seen where the balls are completely outside the package and oviously there are short
Electronics Forum | Fri May 07 20:08:39 EDT 2004 | Ken
...um also, don't forget that ther are planarity issues associated with BGA devices AND bow-and-twist issues with PCB materials. An example I have one BGA device that has a ball planarity of 7 mils!!! Ant that's the OEM specification! THis will re
Electronics Forum | Wed May 19 04:27:18 EDT 2004 | johnwnz
Also look at IPC 7095 which is all abotu BGA processes including rework. the profile will be 100% based on your board - how many layers, how many are ground & signal, how many of those are the BGA connected to directly or indirectly, the component we
Electronics Forum | Wed Jun 02 15:12:15 EDT 2004 | jdumont
Try checking out the AT-707 from Advanced Techniques. They are based in Philly. http://atco-us.com/rework707soft.html We've had our for about a year now with pretty much no problems. The website has a video of the operation. Contact Steven Pitkis
Electronics Forum | Mon May 24 14:44:21 EDT 2004 | ekcinieh
My snmall company out-sources all of it's SMT assemblies. We do through work and have dome rework experience with SMT. All of our assemblies are built to "IPC610 Class II". We currently have no one trained to inspect to this standard. What is a pract
Electronics Forum | Fri Jun 18 13:22:50 EDT 2004 | JD
Out of curiosity, what method did you use? I ask because I have used acetone on a Q-Tip to clean up boards after rework for some time and haven't noticed anything like that. Did you notice it right away? Or after some time went by? I may need to re-
Electronics Forum | Sun Jul 18 21:36:42 EDT 2004 | KEN
This is the least desirable method (mirroring). 1. X-ray inspection becomes difficult. I will repeat: x-ray inspection becomes difficult. False fails go up. True fail detection goes down. 2. Remove and replace becomes challenging. You really
Electronics Forum | Wed Aug 25 22:15:44 EDT 2004 | mmk
During BGA rework we are asked to protect adjacent compoennt from secondary and/or partial reflow. That is our normal process. However, the customer is asking that the peak temp of the joint at the adjacent component should not exceed 160C. Can you p
Electronics Forum | Tue Nov 02 08:01:13 EST 2004 | mattkehoe
Isn't that a good reason to use more paste? With just the paste from the balls, do you really get as good a solder joint as with a standard amount of solder paste added? What about voids? Do they go away by not using paste? I am talking about initial
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