Electronics Forum | Thu Mar 27 12:25:14 EST 2003 | kenlchin
additonally, minimizing the rising rate aroud 183'c and decrease the droping rate(near 0.8'c/s) is also a good way .
Electronics Forum | Thu May 01 17:49:33 EDT 2003 | jym2000
Did you check board orientation into the reflow oven? (The Layout components are the same products A & B?) Regards Jesus
Electronics Forum | Mon May 05 02:37:11 EDT 2003 | gaoliangcheng
Maybe you can check the thickness of the solder mask between the pads. If the highest of the solder mask exceed the pad,then the component which was placed will be unbalanced.
Electronics Forum | Mon May 05 03:53:41 EDT 2003 | praveen
Do not 'ON" the nitrogen during reflow. If the pad of the chip is bigger then reduce the pad width from out side. Reduce the ramp rate at any point of the profile below 1 deg c/sec.
Electronics Forum | Mon May 05 03:53:47 EDT 2003 | praveen
Do not 'ON" the nitrogen during reflow. If the pad of the chip is bigger then reduce the pad width from out side. Reduce the ramp rate at any point of the profile below 1 deg c/sec.
Electronics Forum | Mon May 05 09:53:13 EDT 2003 | k_h
Stencil thickness = 175 microns? If my math is correct, 175u=0.175mil, and if that is english units then it is inches. I'm not understanding this correctly, please clarify for my sake please, are you saying the stencil thickness is 0.000175 inches th
Electronics Forum | Mon May 05 12:16:07 EDT 2003 | russ
A micron is 1 millionth of a meter, this term is no longer used according to my dictionary. I would have to agree with the dictionary. Anyway, 175 microns is a little more than 6.8 mils. Russ
Electronics Forum | Tue May 06 05:02:42 EDT 2003 | Grant
Hi, Ok, thanks for the reply, and this is really interesting. I wonder if there are any good articles about this to read somewhere. Regards, Grant
Electronics Forum | Tue May 06 06:29:06 EDT 2003 | yukim
Hi, No, the layout is different, but both have chips located arallel and perpendicularly to the flow direction. And we do have defects in both orientation. What about the PCB warpage? Sometimes we find warped PCBs. Could this affect? Thanks, Yu.
Electronics Forum | Tue May 06 22:31:52 EDT 2003 | yukim
Yes, we did try: built a lot of 200 PCBs with Sn62Ag2 solder paste (we have been using Sn63) and it helped, but not eliminated the problem.
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