Electronics Forum | Tue Aug 22 16:13:08 EDT 2000 | Dr. Ning-Cheng Lee
FR-4 will be OK for small products such as cellular phones. Here the temperature gradient across the board may be 3-4C only, and the board temperature can be well controlled. At temperature above around 245C, the discoloration and delamination may be
Electronics Forum | Sat Jul 21 09:46:41 EDT 2001 | davef
I was reading something in the paper this morning where the police have found that having a witness look at six pictures of suspects laid-out on a table [the six pack method in their parlance] is more error prone than just looking through the stack o
Electronics Forum | Fri Feb 04 09:23:21 EST 2000 | Casimir Budzinski
If No-Clean flux does not need to be cleaned, then why do I get readings of up to 27(ug NaCl/sq in) on boards that are not washed, up to 23.4(ug NaCl/sq in) on boards washed with DI water only and from 1.2 to 10.1(ug NaCl/sq in) on boards washed with
Electronics Forum | Thu Jan 27 19:14:27 EST 2000 | Dennis
Thanks! It is right that solder paste is somewhat responsible for misssing components in our case. I took a look at the board after placement and I found that component hit the paste, but no where on the board. I guesss dry solder paste (operater pri
Electronics Forum | Thu Jan 27 20:36:13 EST 2000 | Dave F
HJ: Your best chance of running your boards with a single profile is with ovens from the established suppliers (ie, BTU, Conceptronics, Heller, Vitronics, etc). They are experienced in robust control system designs. Stepping aside from that, consi
Electronics Forum | Wed Jan 12 11:50:38 EST 2000 | Larry
I'm about to start building an ENTEK coated board for the first time. This board is a double sided board and I will be using Kester R598 water soluble paste. I searched the archives and read about watching my profile to ensure my flux doesn't burn of
Electronics Forum | Thu Oct 14 20:42:07 EDT 1999 | Jeff Ferry
Grace, As deifned in IPC 7721 Procedure 3.2 Bow and Twist Repair "Bow and twist after soldering shall not exceed 1.5% for through hole PC boards and .75% for surface mount PC boards. The bow and twist shall not be sufficient to cause difficulties d
Electronics Forum | Fri Oct 15 11:05:50 EDT 1999 | Mark Phinney
Earliar we had problems with board warpage, Much of our problem was due to imbalances in the copper on oppisite layers in brief on a 8 layer board the copper on layer 1 should = the copper on layer 8, 2=7, 3=6, 4 = 5. We added copper to some layers t
Electronics Forum | Thu Oct 07 14:40:31 EDT 1999 | Carol Zhang
I have a board, 4 spacers needed to be soldered on the board first with the normal 62Sn37Pb alloy. Then, capacitors are manually soldered on the boards. The density of the board is quite high. If we wave soldered capacitors first, there will be no p
Electronics Forum | Thu Oct 07 15:39:59 EDT 1999 | Carol Zhang
| I have a board, 4 spacers needed to be soldered on the board | first with the normal 62Sn37Pb alloy. Then, capacitors are manually soldered on the boards. The density of the board is quite high. If we wave soldered capacitors first, there will b
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