Electronics Forum | Fri Mar 27 12:59:22 EDT 2015 | ppcbs
That is a strange task. I must ask what is the purpose? When performing BGA Rework the goal is to recreate the manufacturing process of using the reflow oven. It is important to have even heat of the BGA and PCB from top to bottom. Using top heat o
Electronics Forum | Thu Sep 15 11:16:20 EDT 2005 | pjc
Thanks Steve, good point about warped boards, which are common with doube-sided reflow. Centerboard support helps minimize on reflow. We did do modification to the workboard holders to ensure boards are secured. The boards where small enough that war
Electronics Forum | Fri Jan 19 14:32:35 EST 2007 | Mike Hunt
What pitch IC? Perhaps a nickel stencil will work. Are your board FR4? Warping the board could play a major factor in solder shorting.
Electronics Forum | Mon Nov 28 09:46:24 EST 2005 | pjc
I have waved gold (ENIG) boards. That's a pretty hot pot at 260C, wow. I have used 245C with good results. All other parameters look OK a glance. Well, PCB temp looks a little hot too at 130C before pot. 90-100C is typical for most No-Clean flux. At
Electronics Forum | Fri Jun 28 11:25:01 EDT 2002 | dason_c
You need to check your pot temperature and the board surface temperature. You know the melting point of the 63/37 at 183C. If your top side surface temperature is above this point and second reflow may happen. Also, the board will warp and may cau
Electronics Forum | Fri Jul 28 14:34:13 EDT 2000 | Gary Simbulan
Belive it or not, these boards were run through a Centech batch mode Vapor Phase machine. Single stage top side IR preheat. Vapor temp 218 C. Solder paste is an SN62 RMA.The boards were FR4 8 layer w/ solder mask, fairly conventional as might be e
Electronics Forum | Fri Aug 28 15:39:14 EDT 1998 | smd
Does anyone know about the ANSI/IPC PCB warpage standard? What is the best way to determine weather boards are warped or not? What equipment works best? Or, is there a general rule of thumb that is also compliant with the standard? I would like to he
Electronics Forum | Fri Aug 28 16:24:56 EDT 1998 | Dave F
| Does anyone know about the ANSI/IPC PCB warpage standard? What is the best way to determine weather boards are warped or not? What equipment works best? Or, is there a general rule of thumb that is also compliant with the standard? I would like to
Electronics Forum | Wed Aug 10 10:41:23 EDT 2005 | patrickbruneel
Bob, Great theory if you're selling SN100C, but I have to disagree that an alloy being 4�C off eutectic will cause cracks. When a solder joint exits the solder wave, there is an immediate drop in temperature of 100�C. so being off 4�C is irrelevant.
Electronics Forum | Mon Oct 29 18:21:43 EST 2001 | slthomas
We recently have received a lot of warped (bowed and/or twisted behond IPC 600 specs.) bare boards (some our fabricator's fault, some ours by design) and I can't help but figure that long term reliability will suffer when building product with them.
