Electronics Forum | Tue Dec 28 03:54:50 EST 2010 | riscy00
Hi Has anyone has thermal capacitance model for QFN (9x9) package with exposed pad 7 x 7 (or 6 x 6). Ideally between junction and case, junction case and board (JESD51-7 or similar). I wish to do transient with spice, to established how long it tak
Electronics Forum | Wed Jul 17 03:36:00 EDT 2002 | robbied
Answers are: *Mainly copper and potassium. *it looks like a soft growth. *customer will not accept this, hence the returns. These boards are either reworked or scrapped. *Flux is not an issue. *The cleaning process has been found to be the cause of t
Electronics Forum | Tue Oct 10 13:16:46 EDT 2006 | wondering
I have a schematic drawing on a board I've never seen before. It looks like a zener but has 2 arrows pointing toward the junction line. Anyone have any idea what type part this is. The part itself looks like a radial cap.
Electronics Forum | Wed Dec 31 09:10:48 EST 2014 | rgduval
If you suspect a short, check the resistance on a new board that hasn't been powered up. The data sheet should give you the junction resistances that you're looking for. Double check against a component not assembled on the board. If you measure a
Electronics Forum | Wed Mar 24 10:26:51 EST 2004 | mapell
Daniele The other repsonses have it right. The junction of the wires measures the temperature. If your poduct needs to be re-used I would suggest either kapton tape or aluminim tape(the better of the two). If this is your "golden board" I would
Electronics Forum | Mon Mar 22 05:39:36 EST 1999 | Bob Willis
Has any one seen failures of chip resistors after 1-2 years where the junction between the silver termination and the restive element on the top of the ceramic has corroded through. This results in a high resistance failure after this period of time.
Electronics Forum | Fri Jan 18 10:55:53 EST 2002 | cebukid
Okay here's what happened. We've got a "bonepile" of old obsolet profile boards with thermocouples attached. I asked the production Supervisor, could he have one of his people DE-SOLDER the T/C's, put them in a bag, and give them to me. So, what h
Electronics Forum | Mon Oct 28 21:56:56 EDT 2019 | sarason
I presume you mean at microwave frequencies. If not get it right in the CAD. Programs such as Microwave Office and VSS make it easy. Also Ansoft, Keysight Eagle etc. Having used MO and Eagle I would heartily recommend them. In the bad old days one tr
Electronics Forum | Tue Mar 23 02:32:23 EST 1999 | Bob Willis
| | Has any one seen failures of chip resistors after 1-2 years where the junction between the silver termination and the restive element on the top of the ceramic has corroded through. This results in a high resistance failure after this period of t
Electronics Forum | Wed Mar 24 02:23:14 EST 1999 | P.L. Sorenson - Technical Consultant
| | | Has any one seen failures of chip resistors after 1-2 years where the junction between the silver termination and the restive element on the top of the ceramic has corroded through. This results in a high resistance failure after this period of
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