Electronics Forum | Tue Aug 24 21:52:06 EDT 2004 | rose
recently I met one very interesting issue with my board and connector. substrate of the board is copper with immersion silver, pad size is about 3x1mm. we print lead-free paste on the pad, then put the connector on the paste. The board was reflowed u
Electronics Forum | Wed Aug 25 20:48:17 EDT 2004 | rose
Hello recently I met one very interesting issue with my board and connector. substrate of the board is copper with immersion silver, pad size is about 3x1mm. we print lead-free paste on the pad, then put the connector on the paste. The board was refl
Electronics Forum | Wed Aug 25 21:25:28 EDT 2004 | davef
First as a nit, your �substrate� is probably NOT copper. It�s probably FR4 fiberglass/epoxy. Substrate. Base Material. A supporting insulating material upon which parts, components, and elements are attached. Second, enough of that, on to your i
Electronics Forum | Tue Oct 27 05:51:28 EST 1998 | jacqueline coia
Could you please tell what are the current avaliable standards, if any (BSI/IPC) for a measurement value on the mechanical pull strength on SMT IC leads after reflow. Thanks in advance, Jack.
Electronics Forum | Wed Dec 09 10:45:56 EST 2015 | huske
I've put down a SOT223, close enough to your 3pin transistor, in the same situation you have. The large pin was to be soldered on a large exposed ground plane in the corner of a board, over 2"x2" exposed area. We left the paste file as is, so where
Electronics Forum | Mon Oct 18 22:15:11 EDT 2004 | KEN
I have two industry leading customers that have specific requirements for components to survive 30 seconds above 230C. In one case I have a custom ASIC that is heat sinked on the die (to the PCB). The sink pulls heat out of the lead frame very effi
Electronics Forum | Sat Jan 19 10:58:23 EST 2008 | slthomas
That's a good idea. We did pull the bridge piece off of one just to see what happens with the receptacles only, so no flux blockage. They flowed great with no blowholes, but also filled with solder. :/
Electronics Forum | Tue Sep 18 10:29:21 EDT 2012 | davef
Sorry. I don't see any solder balls. To me, it looks like the solder wetted the pad and then pulled back. It's called dewetting. It's a defect. Ask your supplier for a SEM analysis. I'm interested to know what he / she says.
Electronics Forum | Tue Sep 18 21:48:26 EDT 2012 | vergara1
Sorry. I don't see any solder balls. > > To me, it > looks like the solder wetted the pad and then > pulled back. It's called dewetting. It's a > defect. Ask your supplier for a SEM analysis. I'm > interested to know what he / she says. I see
Electronics Forum | Thu Dec 09 17:45:27 EST 2004 | davef
You're correct. There is no criteria for no-lead, but there none for SnPb, either. Solder joint strength in pull/shear will vary with lead geometry, solder volume, lead metal/metallization, the way the test is done.
