Electronics Forum | Sat Feb 01 09:01:14 EST 2003 | davef
It sounds like your board is "dome shaped", some call it "cupped". If so, this is more of a twist than a bow. Before moving on, if we receive a board that is so torqued that we can't figure-out how to measure it, we reject it. Go back to your TM-
Electronics Forum | Fri Mar 14 04:42:24 EST 2003 | emeto
Hi, About Thombstone defects: 1.Placement accuracy-main reason 2.Soldering-should be right on pads.The print should have regular shape.The quontity of the solder on both pads on one component have to be equal. 3.Reflow: the profile have to be made v
Electronics Forum | Tue Mar 18 11:51:24 EST 2003 | slthomas
I like this answer! Part geometry, part mass, land pattern, print accuracy, reflow profile, placment accuracy, and aperture shape all play a role. If you use a homeplate to reduce solder balling, have high profile/low mass parts AND place more to
Electronics Forum | Tue Apr 01 11:18:47 EST 2003 | cyber_wolf
Is anyone out there successfully screen-printing SMD adhesive on an 0402 layout? We have successfully done 0603 and larger, but the deposition consistency on the 0402's is just not there. We don't always get enough epoxy on the board. We have tried a
Electronics Forum | Tue Apr 15 14:10:30 EDT 2003 | russ
here is how it is done. 1.Position the stencil in the machine. 2.Position the board onto the PCB tooling as close to being aligned with the stencil as you can. 3.Place mylar or some thin clear material over the board. your printer should have prov
Electronics Forum | Fri Apr 18 11:12:37 EDT 2003 | tsongshe
Thanks Dave.F. I 've carefully read what you recommended,but still can't get the answer.it's two different suppliers with diffrent pad patterns of each components.one of them can work well,while the other cant do.I think it must has something to do w
Electronics Forum | Fri May 09 11:09:47 EDT 2003 | k_h
Each machine has two feeder tables, one is fixed, the other interchangable. Parts on both sides of the machines does not create a kitting problem but can be inconvenient for feeder replenishment. I have found "U" shaped lines to be much more operator
Electronics Forum | Fri Sep 19 11:49:54 EDT 2003 | chrissieneale
OK, so is anyone qualifying CGA's yet? Our first batch of CGA qualification is not going too well. We stuck with the teardrop shaped pad but the solder fillet is not as big as expected. What size pads is anyone using, i'm getting conflicting informat
Electronics Forum | Fri Oct 24 18:07:50 EDT 2003 | russ
Flux is used with both lead and lead free. Lead free usually or always uses a no-clean chemistry while lead uses both no-clean and water soluble dependent upon the application. As far as temp profiling a standard way to go is melting point + 30 C. f
Electronics Forum | Mon Nov 24 10:41:29 EST 2003 | ilona
Hi, there is also a German company making odd-shaped component insertion equipment, actually very very suitable for LED placement and soldering in the same process cycle. LED's are held in position until soldering is complete, straight and in the s
