Electronics Forum | Fri Nov 12 10:20:53 EST 1999 | Wolfgang Busko
Now an than I hear, read about the same thing but without mentioning specific frequencies. It�s something that worries me in the back of my mind but not in actual daily workflow. Our boards go up to 50Mhz with digital bus systems and are made with no
Electronics Forum | Wed Nov 10 02:20:07 EST 1999 | Marc
The padsfor large heat sinks are being designed on our boards with large copper ground planes surrounding them by our engineers. I am having great difficulty keeping the reflow temperature below 230 degrees in order for the temperature of the copper
Electronics Forum | Tue Nov 09 05:14:49 EST 1999 | Wolfgang Busko
Hi all, our problem we face is the mismatch of conductor width on the delivered PCB and the nominal width given by CAD-data. With CAD we are improving pads and conductors to match the specific needs for soldering and the board houses counteract our i
Electronics Forum | Sat Nov 06 10:00:11 EST 1999 | Robert Oertner
If you are talking about reflowing surfacemount on the solder side of the assembly, that is accomplished by gluing the smt components to the bottom of the board. I recomend that you use a chip wave in conjuction with the normal wave to get the best r
Electronics Forum | Wed Nov 03 22:14:03 EST 1999 | Dave F
Anthony: John's points are well taken. All SMT components float to some degree. Fly shit floats more than multi-lead. Well duh!!! I know of no formula. The most cogent discussion is in THE BOOK (Klein Wassink's "Soldering In Electronics), but i
Electronics Forum | Fri Oct 29 13:45:03 EDT 1999 | David Vulcano
We are placing several axial components that have STEEL leads. Have noticed that the steel components do not get good flow thru(we manufacture to IPC-A-610 Class II Standards which reqires 75% flow thru) We are using Seho Wave Machines with Nitroge
Electronics Forum | Thu Oct 28 18:14:51 EDT 1999 | John Thorup
Try looking for paste contamination somewhere. Dirty stencil, printer table or fixtures. Placement table/fixtures. Reflow belt/conveyer. Reuseable finger covers, if used. Try covering the fingers with Kapton tape during different stages of the proc
Electronics Forum | Wed Oct 27 17:59:54 EDT 1999 | John Thorup
How about some of the more rigid materials like the commercial fixture manufacturers use to machine solder/assembly fixtures from? Glastic, an anti-static version of Delmat and proprietary materials from MB manufacturing come to mind. Search the arc
Electronics Forum | Tue Oct 26 08:17:54 EDT 1999 | William
Dave, Last question(s). What do I do about a gold porosity problem? Dave: How would I approach the board house to check for this? They use a very well known chemistry, but is that where the pblm lies? Or would it be in their process, cycle times
Electronics Forum | Fri Oct 22 21:23:59 EDT 1999 | se
Tombstoning is usually oven profiling, see October 14 thread below. Aperture rules are misleading. Component mix, stencil thickness, paste factors, all contribute. Also, are you making the stencil from a paste or pad layer or from a soldermask layer?
