Electronics Forum | Mon Aug 29 22:48:09 EDT 2011 | davef
Rich Here's what Humiseal says: Thermal Properties The coating must be able to withstand localized thermal 'hot spots' generated by components. High temperatures can cause short-term changes in coating characteristics, such as softening and lowered e
Electronics Forum | Mon Apr 01 20:10:24 EST 2002 | davef
Oh. [Howabout if I smack you?] If ahma connectin� wif whut yer sayin�, you: * Don�t like the appearance of the glue slobberin� out from under the component even though there is no apparent glue on solderable surfaces. * Concerned about the hydrosco
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 | 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 | Fri Jan 20 08:55:31 EST 2006 | patrickbruneel
Steve, How do you measure the resistance is it by probing the surface? Concerning the alloy there is a straightforward linear correlation between the tin content and the electrical conductivity of the alloy. The higher the tin content in the alloy,
Electronics Forum | Tue Aug 13 20:58:06 EDT 2002 | davef
Peterson: Ionic flux residues when combined with moisture and a voltage differential can plate conductive �fingers� on the surface of a PCB, but that doesn�t sound like what�s going on here. Your NC flux should not be particularly conductive. For
Electronics Forum | Sat Jun 19 08:37:25 EDT 1999 | Dave F
| There is a PCB with SMD components glued on bottomside. When I make tests for checking the resistance of glue the result is a break in the surface of PCB. | | How can I measure the surface resistance of PCB surface? | How can I increase this resis
Electronics Forum | Wed Jun 16 14:14:07 EDT 1999 | Dave F
| Hello, | I am looking for the surface resistivity and volume resistivity of standard fr4 as a function of temperature and /or humidity . can any one help? | Frank: Sorry I'm so late getting back to you. 1 Use either ASTM D5109-94 or IPC-TM-6
Electronics Forum | Fri Jun 18 03:31:38 EDT 1999 | Frank
| | Hello, | | I am looking for the surface resistivity and volume resistivity of standard fr4 as a function of temperature and /or humidity . can any one help? | | | | Frank: Sorry I'm so late getting back to you. | | 1 Use either ASTM D5109-
Electronics Forum | Sun Aug 08 11:15:32 EDT 1999 | Earl Moon
| | Mike, | | | | Got your message and those of others concerning PCB fab supplier evaluation and qualification check lists, etc. I have a severe problem here in WI as I can hardly access the internet, and when I do it is cut off abruptly for no goo
