Electronics Forum | Fri Apr 18 09:45:42 EDT 2003 | k_h
Transistors? Are you referring to SOT-23 packages? Are the solder paste and part properly registered before reflow?
Electronics Forum | Tue Apr 22 11:02:42 EDT 2003 | k_h
I'll throw this out there also: http://picturecenter.kodak.com/share?invite=HE2r4mzhP5YLJkvkhU1o It shows void slots (purple) in the copper on the perimeter of the smaller transistors heat sink. Should keep the smaller transistor from moving while th
Electronics Forum | Fri Apr 18 08:24:49 EDT 2003 | tsongshe
Hello,all.these days I met many skewed transistors after reflow soldering.we 've tried many ways attemting solving it thoroughly...changing the aperture pattern,solder volume and even changing the size of pcb pad,but the results are not very good.eve
Electronics Forum | Fri Apr 18 10:45:34 EDT 2003 | tsongshe
I'm sure the parts and solder paste are well registered. these transistors are commonly to252 package,and sometimes to263 package.I 've a picture of these two diffrent kinds of pad patterns of to252,but i don't know how to post it here... Thanks ®ard
Electronics Forum | Fri Apr 18 10:28:57 EDT 2003 | davef
Here's how Kevin posted his pix http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=24067
Electronics Forum | Fri Apr 18 18:11:38 EDT 2003 | slthomas
"glue the floater in place with chip bonder before reflow" gets my vote. We have decals for DPAKs and TO-252's that don't match either specification, and chip bonder is the only answer if they won't spin the board for you.
Electronics Forum | Wed Apr 23 03:49:13 EDT 2003 | jedduan
I think it will make some progess if you modify the program and let the component shift towards the lead orientation as possible while P&P.
Electronics Forum | Sun Apr 20 07:20:09 EDT 2003 | tsongshe,Bryan
Thanks. *We use TO252 package,but sometimes the skewed components also happen on TO263 package. *we use TO252 package parts from different suppliers,and when we change the parts from one supplier to the others,few skewed transistors happen again. *
Electronics Forum | Sun Apr 20 07:34:42 EDT 2003 | tsongshe,Bryan
Hi,all, I'm very glad here this site to meet so many friends,and learned much from you.It's very lucky that oneday I found this website(forum),and so I come frequently to share many precious experience with you.Thank you very much. Bryan.c.x.she@
