Electronics Forum | Tue Sep 14 14:22:11 EDT 2010 | grahamcooper22
If the HASL was poor quality and very thin you would find this defect....but you would expect to see it on more pads also. Also, you'd expect to see your solder from your solder paste either dewetted on the pad or reflowed onto the BGA sphere making
Electronics Forum | Mon Jun 19 21:40:52 EDT 2006 | davef
While underfilling BGA "mounted" on blacked pad boards could improve the reliability by attaching the BGA to the board, you should believe that all components soldered to the board will be affected by the black pad, not only BGA.
Electronics Forum | Tue Sep 26 08:41:27 EDT 2000 | greg
I am processing PCB's that have an n-tech osp coating and am finding huge inconsistencies in wetting. Some boards process clean with good wetting and the next has terrible wetting. The boards are stored and handled properly. Has anyone had this
Electronics Forum | Tue Oct 10 04:10:43 EDT 2000 | Tanu
Hi, Jacko is right!BGA ispection equipment like Xrays are extream expensive if you want a good system. There is some xrays that you can have low cost but if you are planning to do superBGA�s or want better image you need atleast 80-100Kv with good r
Electronics Forum | Wed Apr 03 10:50:06 EST 2002 | BTaylor
Any time Dave I can tell from your responses you have been around this block as many times as I have.Your right automotive is tough nowadays not only from the quality standpoint, now they want everything for free.
Electronics Forum | Thu Dec 04 14:31:59 EST 2003 | irun
Hallo We are going to clean PCb after assembly (SMD and THT) due to conformal coating. It is small value production with elements on PCB like BGA, QFP. What you recommend or suggest to use : ultrasonic? , spray wash? or something like dish wash???.
Electronics Forum | Wed Oct 30 12:32:10 EST 2002 | dragonslayr
Have you tried doing a reflow of the BGA with the connectors removed? This should solve the question of connector proximity giving you a problem. Also, try rotating the board 90 deg in your rework station before reflowing a BGA. Be sure to rotate th
Electronics Forum | Wed Sep 21 16:25:43 EDT 2005 | GS
IPC-7525 tells you how to make stencil apertures for BGA IPC-7095 tells you how much should be the paste volume in order to get a reliable BGA solder joint. How are your PCB finisced? (HASL, ENIG, OSP, etc?) In case of not HASL, it could be necessa
Electronics Forum | Tue Sep 14 14:07:45 EDT 2010 | grahamcooper22
Hi Gani, HASL is normally very good for solderability providing there is a good consistent coating of HASL on the pcb pad. But it is not unusual to have a very thin coating of HASL on the pad and this is poor for solderability. You then have tin/copp
Electronics Forum | Tue Sep 14 02:46:17 EDT 2010 | grahamcooper22
Hi Gani, Looking at the pictures in the report it looks as if there is a thin coating of solder on the pcb pad....but it looks like the BGA sphere was barely in contact with the pad. This could be caused by insufficient solder paste on this pad...may
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