Electronics Forum | Mon Sep 13 04:37:22 EDT 1999 | Brian
| I noticed that some of our pcb's component legend/designation are unreadable as they are placed under smt pads. Is this correct and according to standard? Although we don't have any problems with them as of now, I would like to know the effects on
Electronics Forum | Tue Sep 07 06:14:27 EDT 1999 | Earl Moon
| | I have a zevatech 570 and 560 my boss want to place bga.s with these machines, Ive told him he needs to ugrade to newer machines. Zevatech say "no problem our machine are number 1". | | these machines dont even offer bga selections. These machine
Electronics Forum | Tue Sep 07 22:07:56 EDT 1999 | NAZEEH CHAUDRY
| | | I have a zevatech 570 and 560 my boss want to place bga.s with these machines, Ive told him he needs to ugrade to newer machines. Zevatech say "no problem our machine are number 1". | | | these machines dont even offer bga selections. These mac
Electronics Forum | Tue Aug 31 19:16:59 EDT 1999 | Steve Surtees
| I am looking for a rule of thumb regarding the maximum ramp standard components (chip capacitors) can tolerate without failure during the reflow process. The standard seems to be 3C\second, but this figure is generally derived from the average ram
Electronics Forum | Wed Aug 18 11:52:35 EDT 1999 | Brian
| WE ARE CURRENTLY HAVING PROBLEMS REFLOWING BOARDS WITH WHITE TIN PLATING. WE ARE NOT GETTING GOOD WETTING ON THE PADS. | WE HAVE CHECKED THE REFLOW PROFILE AND TRIED DIFFERENT PASTE'S. | WE THINK THERE MAY BE CONTAMINATION OR OXIDATION ON THE PADS.
Electronics Forum | Thu Aug 12 22:38:44 EDT 1999 | Dave F
| Hello | | Having a problem with bridging on 20mil pitch qfp, only on the lead groups where squeegee goes over width of apertures. Using MPM sp-200 semi-auto, chem-etch stencil, 9-10mil width opening | 100 durometer blade. Getting "tails" on deposi
Electronics Forum | Wed Aug 04 21:52:54 EDT 1999 | Dave F
| We're getting field failures in a high impedance portion of the circuit. Think the unpopulated pc card has contaminates because we were able to grow dendrites by applying a 9 volt battery across the suspected pad, placed a drop of de-ionized water
Electronics Forum | Thu Jul 15 14:09:23 EDT 1999 | MMurphy
| | I use a Transition Automation Semi- Automatic stencil printer with laser cut frameless stencils. My solder paste is an SN63/PB37 RMA 291. I do not operate with in a controlled humidity enviroment. The room temp generally runs around 70 deg's but
Electronics Forum | Tue Jul 20 07:56:38 EDT 1999 | Mark Quealy
| | | I use a Transition Automation Semi- Automatic stencil printer with laser cut frameless stencils. My solder paste is an SN63/PB37 RMA 291. I do not operate with in a controlled humidity enviroment. The room temp generally runs around 70 deg's bu
Electronics Forum | Fri Jun 25 09:51:35 EDT 1999 | C.K.
| Dear John/Earl | | Thanks for your clarifications. To me also the problem does not seem to be linked with the PCB. The Pre heater temp. is set at | 450 degree C. We are using Alpha Aq. cleanable flux. Can you elaborate on the Desired profilin
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