Electronics Forum | Sun Mar 26 19:02:05 EST 2006 | ms
Hi We are running automatic stencil printers, open squeegees, stainless stencil, stainless blades, print speed 25-30mm/sec. We have a frustrating consistency issue printing .37x.3mm apertures on a 45pin LGA (11 pads each side, 1 large ground in mid
Electronics Forum | Thu Oct 31 11:08:12 EST 2002 | soupatech
Being very new to SMT I won't assume I know what the problem is but.... I had lots of air pockets in solder joints, 95% of the boards. Everyone I spoke to thought it was a problem with my process but when one board was sent to our supplier they admi
Electronics Forum | Thu May 09 17:28:33 EDT 2002 | davef
There is no IPC specification, nor should there be. * There are just too many peculiarities in the design and fabrication of PWB. * The issue is not defining how to store boards. The issue setting expectation for reliable products and allowing you th
Electronics Forum | Sat Jun 28 22:52:34 EDT 2003 | ramanandkini
We have an Electromechanical assembly (clock) that has a step motor on the board. This electromechanical assembly is assembled in a screw less plastic moulded casing. The plastic casing is neither air tight nor water proof. The board is with SMOBC+ H
Electronics Forum | Mon Mar 30 16:02:44 EST 1998 | Michael Allen
| We have successfully put .016" vias in .030" pads. | There is no issue with .030" solder balls, since | the actual volume of the .002" via in pad is small | compared to the ball+solder paste volume. | We did notice random bubbles where, apparentl
Electronics Forum | Mon Mar 27 15:10:48 EST 2006 | ms
Hi Steve Thanks for your reply. Your comments make it sound like it may be the nature of this paste. Any one else agree? Paste control is fairly good. Paste is put in fridge straight after it arrives at inwards goods, (4deg). Removed from fridge
Electronics Forum | Wed Mar 25 16:38:21 EST 1998 | Steve Joy
We have successfully put .016" vias in .030" pads. There is no issue with .030" solder balls, since the actual volume of the .002" via in pad is small compared to the ball+solder paste volume. We did notice random bubbles where, apparently, the sol
Electronics Forum | Wed Mar 25 16:36:10 EST 1998 | Steve Joy
We have successfully put .016" vias in .030" pads. There is no drain off with .030" solder balls, since the actual volume in the .002" depression is low. We did notice random bubbles where, apparently, the solder reflowed and trapped the air in the
Electronics Forum | Wed Mar 25 19:41:01 EST 1998 | Earl Moon
| We have successfully put .016" vias in .030" pads. | There is no drain off with .030" solder balls, since | the actual volume in the .002" depression is low. | We did notice random bubbles where, apparently, the | solder reflowed and trapped the a
Electronics Forum | Thu Jan 31 15:13:20 EST 2008 | chef
You will need to develop your reflow profile which includes drilling a hole through the fab and into the ball for accurate temp measure. During profile/process development you will probably want 3D x-ray (consider contracting that out). Once in prod
