Electronics Forum | Mon Aug 07 10:22:13 EDT 2000 | genglish
Ramon, I have had experience in the problems you are witnessing. The problem can relate to a number of factors. Obviously the printing process is the first place to start your investigations, try looking at the stencil apertures for bleed under the
Electronics Forum | Mon Aug 07 14:02:54 EDT 2000 | Brian W.
If you are satisfied with the apertures, then you need to check placement pressure, plant humidity, and the reflow profile. If the placement pressure is too great, it will separate minute portions of the solder from the pad. When the solder reflo
Electronics Forum | Wed Aug 09 22:00:44 EDT 2000 | Dave F
Hey Charles!!! Where in earthly heaven did you get a TO263 with "large solderable tab (approx 8mm square) on the back and 5 leads"? All the TO263s that�ve reached-up and smacked me have been "TO220s" with a modified tab and three leads that are f
Electronics Forum | Thu Aug 10 12:14:12 EDT 2000 | Charles
It looks like a giant dpak device but with 5 leads. The problem is that on approx 3% of our boards one more pins are open circuit. It appears that the pins are not in contact with the pads. Board is HASL finish IR oven Paste Koki 953i. If you have a
Electronics Forum | Thu Jun 22 11:42:29 EDT 2000 | Chrys Shea
Sal, Silly question: Were the parts skewed before they went into the oven? I've chased down a few similar reflow problems in my lifetime, only to find out it was a pick and place problem. Wrong nozzle size, bad nozzle, feeder not advancing all
Electronics Forum | Thu Jun 15 21:51:17 EDT 2000 | Dave F
Jeff: You're correct �7.1.3 of ANSI J-STD-001C states " Drying / Degreasing states the assembly may be treated to remove moisture and other volitiles." We don't bake "FR4" for love nor money. The archive are littered with threads along this line.
Electronics Forum | Tue May 30 11:51:43 EDT 2000 | JAX
Sal, I have seen this problem placing SMT connectors which exceed 60mm in length. Although I did not use siemens equipment at the time I am not sure if they will place enought force to seat the entire connector flush to the board. They have a maximun
Electronics Forum | Mon Mar 27 20:48:25 EST 2000 | Dave F
Robert: Howya doin' bud? You say "BGA Shorting!!!" I say "Too Much Solder!!!" So, earlier comments about aperture design are appropriate, make good points, and I think we both agree that improvements could be made in your stencil design, but I'm
Electronics Forum | Thu Mar 23 14:17:47 EST 2000 | Finepitch Services
Stuart, My suggestion is a DFM meeting (most of the process people dream about a meeting like this, and luckily, I've been to a few) with: - project manager (if there's one) - customer service rep (annual volume, lot size, product life) - smt proce
Electronics Forum | Mon Feb 05 20:43:27 EST 2001 | davef
1 Solder on gold fingers comes from: 1a About 70 % of the time it's caused by poor cleaning of screen printer, staging area (table), conveyor, reflow oven chain or belt, and keeping boards separate from cleaning process 1b After loading paste onto
Reflow ovens for automated SMT PCB assembly, specializing in lead free processing and nitrogen reflow. The best convection reflow ovens on the market.
4 Vreeland Rd.
Florham Park, NJ USA
Phone: 973-377-6800
.gif)
