Electronics Forum | Wed Aug 24 12:37:38 EDT 2011 | hussman
Hello all, We just got some board back from thermal shock and we found that several of the 2512 resistors opened up. Actaully the solder joint cracked away from the board. All other coponents look great. Boards were good before test. 10 layer bo
Electronics Forum | Tue Jun 16 09:15:56 EDT 1998 | Justin Medernach
| We are very concerned about microcracking in SMT P&P process. I want to know something about: | What is microcracking? | When did it occur? What are the causes? | How can avuid this phenomena? Toni, Micro cracks can be caused by a ton of conditions
Electronics Forum | Fri Apr 11 11:26:09 EDT 2003 | Brian W.
Cracked capacitors usually are not found at ICT. Unless the cap is completely cracked, the capacitance may not change much, and the usual failure mode is a leakage current. This is usually only seen in ESS type testing, when temperature and humidit
Electronics Forum | Thu Jun 25 09:37:48 EDT 1998 | Russ Miculich
The real causes of microcracking are not normally due to pick and place - particularly if you are using a piece of equipment with vacuum pick up and release. The real cause of microcracking is due to thermal stresses on the die and the choice of the
Electronics Forum | Thu Aug 18 09:41:05 EDT 2016 | jbuckley
Typically on my company's Mirtec systems, any anomalies, such as cracks, chips, etc. on chip capacitors and chip resistors are going to be detected with just a basic mounting inspector. We have a full image of the part (solder joint not included) as
Electronics Forum | Thu Sep 11 15:23:31 EDT 2003 | Peter L.
I have come across a rash of failed assemblies that have 0805 capacitors and resistors, bottom side glued, wave soldered and washed. Trouble shooter reported touching up the solder joints on a few areas and the boards would pass test. I had a look a
Electronics Forum | Tue Aug 30 09:49:24 EDT 2011 | blnorman
Guess the better question is why are the resistors and FETs heating to the degree that they discolored the coating? If the coating is discolored, I'd be concerned with the possibility of cracking as dave mentioned. Cracks defeat the purpose of the
Electronics Forum | Fri Jan 26 16:24:10 EST 2007 | Bob R.
Whether there's a fillet or not depends on the component type. Most have a fillet but some, such as QFN's, don't necessarily have one. Have a look at IPC-610D Workmanship Standards to understand when you should expect one and when you shouldn't. T
Electronics Forum | Wed Jul 29 21:16:17 EDT 2020 | SMTA-64387706
Hi, I have a PCB that works fine when tested before conformal coating with HumiSeal 1B73. It seems like the CC is causing electrical issues. We brush it on, so it is a bit thick. After curing we are getting QFNs that do not seem to connect well and a
Electronics Forum | Wed Feb 10 21:41:54 EST 2010 | plaiming
We experiences some failures on PCB assemblies from the field when a methacrylate epoxy adhesive was used to secure some through-hole components to pcb board as reinforcement against vibration. During application, the epoxy covered some smaller SMT c
