Electronics Forum | Mon Jan 15 11:21:48 EST 2007 | davef
Contractor mantra: * Profile is good * Boards are bad On profiles, the key question is: where did you take the profile? We�d guess cracked connections are giving the intermittent test results when pressing on the components. You use acoustic micro
Electronics Forum | Wed Mar 14 00:34:46 EDT 2007 | pyramus
Hi Muhammad thanks for the reply. However, this is my current situation. We are currently using some BGA's with this kind of packaging BGA over BGA. I have verified solderability of the main BGA (below Bga the one w/c will be soldered to PCB) using
Electronics Forum | Tue Apr 22 03:46:19 EDT 2008 | fowlerchang
It is CSP reliability issue, which is the mobile CPU from Spreadtrum. All the tests passed and shipped to customer. They assembly them and tested but failed. After they reflow this CSP with hot air gun, some of the boards passed. We got some board
Electronics Forum | Wed Jul 07 11:02:07 EDT 2010 | davef
Rob gave you very good analysis and suggestions for troubleshooting your non-wetting issue. We agree with his sequence of troubleshooting. The following comments are meant to be a line to supplement Rob's plan of attack. This adds to Rob's comment
Electronics Forum | Mon Apr 29 13:56:19 EDT 2013 | williamaxler
We have a Versaflow 40/50 and ours is setup like this. We have out nozzle test position set so that in the Z axis you are 3.8mm away from the pin. Used feeler gauge Then you can set your gradient per nozzle. Start with a number then do a wave offs
Electronics Forum | Wed Dec 04 08:00:57 EST 2019 | kylehunter
Thank you both. We are using EP256 Solder Paste Sn63Pb37 no clean from Kester. I attached our profile as well as Kester's target profile. We used a populated demo board for the profile. We tested along the width, and was less than a 2c difference.
Electronics Forum | Fri Feb 11 18:09:11 EST 2000 | Glenn Robertson
Russ - I agree with the other guys that the problem could be black pad or some intermetallic problem, possibly related to the "conversion" to HASL finish. But my first guess is still partial reflow at wave soldering. You won't catch it by push
Electronics Forum | Mon Apr 19 14:38:01 EDT 1999 | Chrys Shea
25 PPM)! | | 1. Is there a better process to solder the leads of QFP's with lifted "minute" lifted leads still having a realiable solder joints? | | 2. Or has anybody tried modifying solder pads and use thicker solder paste deposit to compensate fo
Electronics Forum | Fri Apr 24 20:33:06 EDT 1998 | D.Lange
| Looking for anyone who has experience with high temperature soldering. Need to determine why solder joints are failing. Thermocycling of unit is -40C to +140C, 30 minute dwell time, 10 sec. transition time | Your help is appreciated | Ed Holton |
Electronics Forum | Fri Mar 07 05:36:21 EST 2003 | O' Connor
Hi Again, In answer to DaveF - Yes solder is fine where the solder paste is deposited , but the part of the pad visible after pasting is still visible after reflow. Previously the solder paste & all the gold diffused & flowed giving a complete silve
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