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 | 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 | 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 | 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 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 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
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 | 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 | Mon Nov 23 19:20:18 EST 1998 | Kevin
A buddy of mine has problems after depaneling double sided pre-scored PCB's. Resistors near the edge, after put into the slice and dice machine contain micro cracks. He's checked for them before and after depaneling. We figure it is the sectioning
Electronics Forum | Mon Nov 18 20:30:39 EST 2019 | alanyang
The chip resistors are placed on the edge of the board, but the board has no or enough waste tabs. When de-panelizing, the bits may contact and break them. You can use a smt carrier, or add waste tabs in your next assembly manufacturing.
