Electronics Forum | Tue Aug 23 09:53:05 EDT 2005 | davef
There's some good background information on SIR [surface insulation resistance] on the web. Here's an example: http://www.tracelabs.com/TechLibraryDoc.aspx?id=4 Look to IPC-9201 - Surface Insulation Resistance Handbook SIR readings vary with: * C
Electronics Forum | Tue Jul 04 02:31:55 EDT 2006 | Mustang
Calling for an input from the Experts our there. Our customer is questioning the cleanliness of the no-clean product that we produced for them. We were asked to clean the board (localised cleaning) after rework (IC need to be changed due to an up re
Electronics Forum | Mon May 26 04:02:13 EDT 2003 | Franky
Dear sir, I think so with every idea , everyone is correct , paste , pattern of pad design ,profiling or solder mask on PCB ,and one of the cause of tombstone that I found is alignment of machine placing and solder printing , from my experience many
Electronics Forum | Sat Feb 14 19:35:51 EST 1998 | C. Lao
Mr Lao We have some specialist knowledge on this subject and offer both equipment and services for these tests. My first recommendation is that take coupons manufactured by your PC Fabricator and then samples at each manufacturing stage: Bare coupon
Electronics Forum | Thu Jul 06 16:00:11 EDT 2006 | samir
Ionic Cleanliness Testing: IPC-TM-650, Test Method 2.3.25, Section 5, "Dynamic Extraction Method", is the most commonplace method in the industry to test YOUR PCBA's for cleanliness. Run it through your process as normal, and send it out for testin
Electronics Forum | Mon Oct 21 22:15:36 EDT 2002 | davef
First, SIR data is heavily dependant on the test pattern selected. Be very careful when comparing the results of resistance readings taken from different geometric patterns. Second, if yer talkin': * Bare boards, yupper. * Finished assemblies impor
Electronics Forum | Tue Jul 04 08:04:37 EDT 2006 | davef
The heat from a soldering iron will push raw flux across the surface of the board and into surprising places. It's bad practice to squirt liquid low residue flux on the board during rework, because the portion of the flux that does not get heated pr
Electronics Forum | Wed Aug 21 17:44:32 EDT 2002 | davef
Splitting hairs, I expect SIR of all solderability protection, including OSP, to decrease after reflow. What�s more, I expect the SIR of all solderability protection to pretty much decrease over time. The �comb pattern� test specimens meet requirem
Electronics Forum | Tue Oct 13 04:34:53 EDT 1998 | Sanjay Bhatikar
Sir, I have been thinking about your problem. I have a suggestion that may work, although it has not been tried before. How about using two stencils? First print the the whole board with a stencil for 150 micron thickness. Next, place a ste
Electronics Forum | Tue Mar 21 20:33:09 EST 2000 | Dave F
Shane: We don�t dispense, but we have thought about it. Several points about peelable solder masks in a no-clean (low residue) process: � Beware of latex peelable solder mask with a low res process without extensive testing. The problem is usuall
