Electronics Forum | Tue May 13 08:59:13 EDT 2014 | gazelle
Hello davef - could it be you are confusing low thermal emf (Seebeck coefficient) with low temperature solder ? I am looking after solder wire and paste with low Seebeck coefficient - cadmium based alloy was OK but banned in europe due to RoHs direct
Electronics Forum | Mon Feb 15 14:30:00 EST 1999 | Dave Turner
| Any info on the pros and cons of FR4 or Polyamide ref the use of soldering PGAs would be helpful. ie. temp co-efficient diffs, baking, wave soldering, Convection reflow etc
Electronics Forum | Mon Feb 15 14:28:09 EST 1999 | Andy Bellworthy
Any info on the pros and cons of FR4 or Polyamide ref the use of soldering PGAs would be helpful. ie. temp co-efficient diffs, baking, wave soldering, Convection reflow etc
Electronics Forum | Tue Feb 16 12:26:07 EST 1999 | S. Rose
| Any info on the pros and cons of FR4 or Polyamide ref the use of soldering PGAs would be helpful. ie. temp co-efficient diffs, baking, wave soldering, Convection reflow etc |
Electronics Forum | Tue May 05 17:01:25 EDT 1998 | bob
I hear that there is a problem with using ceramic parts that are sizeable. Apparently, there is a mismatch in the Temperature Coefficient of Expansion between the FR4 and ceramic materials which causes the soldered erminations to weaken and eventuall
Electronics Forum | Thu Aug 16 10:52:47 EDT 2001 | vickij
Hi all! I am looking at some precision SMT resistors, and am confused by what they mean by Temperature Coefficient (TCR) of whatever % ppm. Are they talking about from room temperature? Any info would be appreciated. Thanks!
Electronics Forum | Thu Aug 16 19:54:12 EDT 2001 | davef
Understanding Temperature Coefficient of Resistance * http://www.riedon.com/temp_coeff_nt.htm * http://hyperphysics.phy-astr.gsu.edu/hbase/electric/restmp.html * http://www.rit.edu/~674www/programs/phys273/temp_coeff.html
Electronics Forum | Mon Oct 02 20:17:38 EDT 2006 | davef
The different coefficient of expansion of materials used in some BGA can cause warping issues. We've talked about this previously on SMTnet. Search the fine SMTnet Archives. For instance: http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=2
Electronics Forum | Fri Sep 28 16:49:48 EDT 2007 | davef
good * No IMC => bad Intermetallic growths are diffusion limited, and therefore the thickness of the intermetallic is given by: z^2 = (Do)(t)exp[-Q/RT] Where Do (m^2 s-1) is the diffusion coefficient, T(�K) is the temperature, Q (J mol-1) is the act
Electronics Forum | Mon Nov 27 08:05:50 EST 2006 | davef
There is no standard for a strain gage measurement of allowable deflection of a board or a fixture. It's possible that your fixture is causing the BGA cracking that you see. What protion of the BGA is cracking? If it is the solder connection, sear
