Electronics Forum | Wed May 25 15:40:27 EDT 2005 | james
Has anyone had good luck with the reflow on these extremely heavy bga's. This bga has 1517 balls and requires alot of heat because of the thickness of the part. Just wondering if anyone out there can help me.
Electronics Forum | Wed May 25 17:35:53 EDT 2005 | russ
What are the problems that you are seeing?
Electronics Forum | Fri May 27 11:37:13 EDT 2005 | james
But I think the customer is returning these because they are not working in the field due to soldering issues.
Electronics Forum | Thu Jun 02 09:58:35 EDT 2005 | james
Any other advice??
Electronics Forum | Thu May 26 10:47:28 EDT 2005 | james
What is the highest temperature set at in your oven and your belt speed. Also what type of oven do you have? Thanks much. Your right about alot of heat needed. We actually see the outside balls much flatter and soldered compared to the middle bal
Electronics Forum | Thu May 26 21:07:22 EDT 2005 | KEN
This is caused by cte mis-match. The balls in the corners are short and fat. The balls near the null point are tall and more normalized. I don't remember what the zone settings were... BTU VIP98 BS was probably 22-25 IPM
Electronics Forum | Wed May 25 22:36:17 EDT 2005 | KEN
...just placed 100 xilinx 1681. These have the integrated heat sinks and bubba these need a lot of heat. You end up with 0402's on the very end of the board that get very hot (225-230) just so you can get the xilinx up to 215C at the balls.
Electronics Forum | Thu Jun 02 11:01:28 EDT 2005 | davef
Xilinx recommended reflow ||Sn-Pb Eutetic||Sn-Pb Eutetic ||Pb-Free||Pb-Free Profile Feature||Large Body||Small Body||Large Body||Small Body Average ramp-up rate (TL-TP), *C/seconds max||3||3||3||3 Preheat - Temperature Min (Tsmin), *C||100||100||150|
Electronics Forum | Tue Jun 06 13:02:25 EDT 2000 | Keith Luke
In the Chapter 3 on "Thermal & Mechanical Stress," Harry Charles mentions a "homologous point" in 3.5. We are unfamiliar with this term. What is this point? What are the implications of solders in operating environments below their homologous poin
Electronics Forum | Tue Jun 06 15:01:10 EDT 2000 | Charles Harper
The homologous point is the temperature midway betweeen the melting temperature (of the solder) and absolute zero. Below this point the solders are harder, stronger, and more resistant to fatigue. As solders are exposed to higher temperatures above
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