Electronics Forum | Fri Nov 20 14:50:13 EST 2009 | davef
One of our instruments has a high impedance front-end. We: * Passed functional test in the environmentally controlled shop. * Failed test, on the same unit, while carrying it to burn-in chambers in an uncontrolled part of the plant. Solder flux resi
Electronics Forum | Mon May 14 17:12:20 EDT 2001 | davef
Continuing along the path that Brian took ... IPC-7525 gives design guideline for stepped stencils. It goes something like: * Stepped area SB GT 25 thou from pads located on the greatest thickness of the stencil * Pads in stepped area SB GT 35 tho
Electronics Forum | Mon Sep 20 16:27:58 EDT 2004 | blnorman
Besides the processing tests (different print speeds, print delay times, etc.) one test we've had to use is humidity exposure. Solderballing due to high outside humidity is a problem in our plant. So we expose paste to 85% humidity for various time
Electronics Forum | Sun Nov 21 21:40:13 EST 2004 | John
I'm experiencing an impedance breakdown on an 0805 ceramic cap. In the application, the cap is at a 16V bias at all times. The unit failed in an extremely high humidity condition. We are using a NC flux and have determined there was flux underneat
Electronics Forum | Tue Jun 03 13:01:16 EDT 2003 | Ramanandkini
We have some experience in manual application of conformal coating using a brush that too for small circuits espceially on the soldered pads. We use Chase corporation's Humuseal 2A64. This passes high humidity tests. I am also in touch with Lackwere
Electronics Forum | Wed Feb 14 15:01:59 EST 2007 | davef
Latex is not a conductor. It's an insulator. So, it will not conduct a charge to the metal wire rack. You can test this hypothesis by charging a latex tube in the shop and measuring its conductivity to ground. We believe that you should not have
Electronics Forum | Sun Sep 07 20:51:52 EDT 2014 | natashakt
1. Is the high RH environment consistently at 72% RH and 21.4 degrees Celsius? No, over the past 2 weeks I have recorded the highest at the moment: 67% RH at 22.6 degrees C and lowest (it is Spring not summer yet): 31.9% RH at 19.0 degrees C. Or d
Electronics Forum | Mon Jan 04 21:03:22 EST 2010 | cman
1) I'm not familiar with the acronym CAF. Could you spell that one out for me? 2)Why do you feel they need to be baked? Are they in a high humidity enviornment? the only time we bake is when we are dealing with moisture sensitive components. Do you b
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 | Wed Jan 04 13:47:11 EST 2006 | russ
To answer your question it was mentioned that allowing the boards to cool slightly between reflow and wash may help this case to eliminate thermal shock from immediately going into colder water straight out of the oven with no cooling. In looking at
