Electronics Forum | Mon Nov 12 13:04:35 EST 2001 | slthomas
We've got a problem with a fine pitch board that has about .005" registration error at each end (towards the center of the board) when it's printed. Apparently we've got a case of board stretch generated at the fab shop. I still have to do some mea
Electronics Forum | Mon Jun 08 14:19:30 EDT 1998 | Gary Simbulan
Earl, et al, Boy things get old and cold around here fast. I promised more detail on my capactior problem and I thought I could drop something completely different in the same message and tell a tale of solder balls. First the caps. We still have
Electronics Forum | Mon Aug 14 05:45:16 EDT 2023 | dimamalin
First, this is the result of bad printer setup. Adjust knife pressure, PCB gap, separation speed, tooling, and stencil cleaning. Pay attention to the coating of contacts pad and height of solder mask of PCB.
Electronics Forum | Wed Sep 18 19:43:12 EDT 2002 | dragonslayr
One more variable I've remembered - pad height with respect to solder mask height. Pads being too low can cause stencil "gasketing" problems that in turn allow more paste to be deposited than needed. Are your fabs HASL or some other media?
Electronics Forum | Wed Sep 18 12:35:56 EDT 2002 | stepheno
Fourth - > back to design of PCB. Are there solder dams of > mask between the pads? If yes, that helps. If > not, pay close attention to stencil aperture > width and be sure that the aperture deposits less > paste by 1-2 mils per pad, centered o
Electronics Forum | Wed Sep 18 12:31:16 EDT 2002 | dragonslayr
My suggestion is to conduct a Design For Manufacturing (DFM)study on the assembly in question. Pay particular attention to the pad sizes, component lead dimensions and satisfy yourself that those two factors are correct. Given that pads match compone
Electronics Forum | Wed May 27 13:42:08 EDT 1998 | Chrys
| R&D is currently designing a board with smt components on both sides of the board. They are adding a 16 pin IC Gull wing. on the bottom side of the board. I have asked for only caps and resistors to be placed on the bottom side. Is there a recommen
Electronics Forum | Wed May 27 14:35:52 EDT 1998 | Justin Medernach
| | R&D is currently designing a board with smt components on both sides of the board. They are adding a 16 pin IC Gull wing. on the bottom side of the board. I have asked for only caps and resistors to be placed on the bottom side. Is there a recomm