Electronics Forum | Mon Jan 04 23:15:35 EST 1999 | Kris Ewen
Where I worked, we used 0.014" square aperatures (several mfgs. have proven the benefits of square & I've seen a better transfer efficiency myself). Some mfgs use smaller edge lengths & have had success. 0.005" thick stencils give better transfer e
Electronics Forum | Thu Oct 08 03:33:50 EDT 1998 | Thomas Blesinger
| | I am trying to find out, what possibilities I have, to print solder paste on a board, when the task is to have 120 Microns thickness for the biggest part of the board (85% of the real estate), and then have 250 Microns of thickness on the remain
Electronics Forum | Thu Oct 08 14:04:04 EDT 1998 | Kris Ewen
Manish, I've seen similar phenomenon when processing CSPs on our cards. In our case, we were placing the components over the opening to in-pad blind vias. Due to poor drilling and plating processes by our board suppliers, volatiles were outgassing
Electronics Forum | Tue Sep 22 12:58:18 EDT 1998 | Chyrs
| How can I solve the small solder ball in the N2 W/S ? | The Oxygen level is 10000~20000ppm & no-clean flux. Yuen, Sorry I an't got an answer, just more questions. 1-2% O2 in your wave solder - are you running membrane generated nitrogen? I don't
Electronics Forum | Mon Sep 14 11:56:38 EDT 1998 | Ben Salisbury
| Our company currently donesn't have any type of sonic wash to wash boards that have been "miss printed" Wanting to know the best way to go about this. So what we are having to do is spray down the boards with alcohol and wipeing the solder paste
Electronics Forum | Tue Sep 15 08:59:59 EDT 1998 | Chrys
| I am running composite fixtures on my wave solder machine and after about 500 passes each (1 month)they are showing serious signs of wear in that the composite surface is bubbling up and glass fibers are also starting to show. | The problem here
Electronics Forum | Fri Sep 11 09:45:39 EDT 1998 | Earl Moon
| I'm very familiar with the great board space savings of BGA and all the "claims to fame." However, can someone out there tell me if any concern exist in the inspection realm. Additionally, solder cracking, CTE/TCE mismatches, no leads for stress re
Electronics Forum | Tue Sep 08 15:11:26 EDT 1998 | Mike Demos
Rich: In my experience, I have seen three cases of SMT Capacitors cracking: 1. Due to thermal shock when entering the wave solder. Note that these were 1210 package sizes on the wave solder side of the boards. We were able to trace this back to th
Electronics Forum | Tue Sep 01 19:31:36 EDT 1998 | Kallol Chakraborty
| We are experiencing shorting on a BGA. The part has a 1mm pitch with a 196 I/O count. The problem seems to pop up without warning & disappear in the same manner. | Our pad design is .020" diameter pads with .025" solder resist diameter. The ce
Electronics Forum | Tue Aug 25 21:01:45 EDT 1998 | Peter
We use an Intermec 3240 Thermal transfer printer and print on polyimid label material that survives the reflow and wave solder (top side only) process without turning black. Labels run around 3-4 cents per depending on the size (We found Imtec label
winsouce.jpg)
.gif)
