Electronics Forum | Wed Sep 29 11:32:02 EDT 2010 | asksmt
Hi, i have designed Double sided PCB all SMT Parts are mounted on bottom side and TH on Top Side. with recent testing we found that the decap needs to be placed closer to IC VDD-GND Pins. as i can't place TH Parts since i don;t have space on botto
Electronics Forum | Wed Feb 23 00:45:49 EST 2011 | tsvetan
Does someone with technical knowledge knows what exactly happend with the solder paste after the shelf life pass? What we have seen is sometimes flux separation which disapear after a good mix, and change of viscosity i.e. drying. The tin, silver and
Electronics Forum | Tue Nov 06 22:37:35 EST 2012 | davef
Ryan ... "As for bismuth-based lead-free alloys, a lower melting temperature than that of tin-lead is offered together with a cost similar to that of tin [in the area of $3/lb]. Unfortunately, bismuth in soldering alloys tends to create embrittlemen
Electronics Forum | Thu Dec 29 09:03:03 EST 2016 | sumote
I would cut a piece of cardboard to the same dimensions as your circuit card. Run that through the fluxer of your machine and pull it out before the pre-heater. Take a look at the cardboard and verify that flux has been sprayed on it. That board look
Electronics Forum | Tue Nov 05 10:55:41 EST 2019 | engmagana
Hi Ameen, Did you fix it? I had the exact same problem with the same type of coil , check the images , LF solder SAC305, we have adjusted the solder apertures to the minimum solder required to have a strong joint enough to break the pad from the bo
Electronics Forum | Thu Sep 30 13:37:08 EDT 1999 | Dave F
| | I am having problems processing immersion gold boards. The achieved solder joints appear acceptable a la IPC-A-610, but the resultant joint does not fully cover the land, i.e. you can still see an outline of gold pad. | | What is the best way to
Electronics Forum | Thu Aug 06 12:49:41 EDT 1998 | justin medernach
| I am looking for advice or information from anyone about the possible reliability problems associated with epoxy on solder pads of discrete devices. Will the epoxy expand and lift over time, Will there be adverse reaction between the solder and the
Electronics Forum | Wed Apr 08 13:46:22 EDT 1998 | Scott Cook
| Sylvia, | I believe you will find that contrary to Scott Cooks submission, that the work carried out by Robert Clark of Hughes Missile Systems at (then) Tuscon Arizona formed the basis of the MIL-F-14256 spec which "Qualified?" or at least "Approve
Electronics Forum | Fri Apr 04 09:28:59 EST 2003 | davef
Q1: Anyone has any ideas on how this post-SMT reflow solder joint could have changed to whitish joint? A1: Dunno. You need to tell us more. For instance: * What is the appearance of this white residue? [eg, glassy / coarse, milky colored / opaque,
Electronics Forum | Fri Jul 29 19:12:30 EDT 2005 | Jason Fullerton
In the true sense of the term, tombstoning can only occur during reflow. Now, if your solder joints are cracking during thermal cycling and opening on one end you still have a problem - it just isn't "tombstoning". What laminate are you using on yo
