Electronics Forum | Sun Nov 04 01:04:04 EST 2007 | omidjuve
we are manufacturing some rf boards that works on a high frequency margins now our boards doesn't pass in impedance test and we concluded that the problem might cause by the solder paste that we are using . our solder alloy is sn62/pb36/ag2 and we t
Electronics Forum | Tue Nov 06 07:16:36 EST 2007 | hussman
Run a board with regular solder paste and put your worries to rest. Total cost about $0.50 American. Total Time about 3 minutes placement - 6 minutes oven. Looks like it might be worth a cup of coffe and 9 minutes of your time to try.
Electronics Forum | Thu Nov 08 13:12:02 EST 2007 | russ
Annular rings are too big, it is acceptable to have shorts on the common conductors. I would be willing to say the "other" supplier may have modified the artwork as well. Good fluxing, preheat and proper immersion depth are key to eliminating short
Electronics Forum | Mon Nov 05 02:51:48 EST 2007 | omidjuve
our boards have many smd pads that has vias under them so when the screen printer wants to print the solder paste on it , it will penetrate through the via to the bottom side of the board and cause many problem for us . i want to know that is it sta
Electronics Forum | Fri Nov 09 10:15:27 EST 2007 | devajj
Of course if you are an OEM you could go back to your design engineers and tell them via's in SMD pads is unacceptable. Put that in your DFM design guidelines. If you are an EMS provider you can also influence your customer by explaining the impa
Electronics Forum | Tue Nov 06 16:20:52 EST 2007 | jmelson
Mostly, you don't want to do that. Whoever designed the PCB should be able to produce a "pick and place report" or similar file that lists components by designator (R123) component value/type (100 Ohm 0805) and XY and rotation. If there's absolutel
Electronics Forum | Tue Nov 06 11:46:38 EST 2007 | aj
Hi Tony, You should search the archives as there is a lot of threads on this topic. A couple of quick checks - 1 - Are you running a Leadfree Process ( if you are not Leadfree maybe the BGA is ? ) 2 - Check your reflow profile is hitting all the
Electronics Forum | Wed Nov 07 09:19:16 EST 2007 | pjc
Could be not enough peak temp. Do you have a profiler? I'd measure at the BGA joints- drill under board to get access to BGA solder joints and embed a couple of thermocouples with hi-temp solder, then run your profile to see max. temps. and that prof
Electronics Forum | Wed Nov 07 01:55:43 EST 2007 | Michael Konrad
Hi Rafael, You just missed three shows (two in Chicago and one in Orlando). Next major US show is APEX (April 1 - 3) in Las Vegas. If you want to see all the players sooner, Productronica is next week in Munich Germany. Mike Konrad Aqueous Techno
Electronics Forum | Wed Nov 07 18:11:44 EST 2007 | jmelson
I can't answer for wave, but we tried some Sn100 paste for reflow, and couldn't get it to work worth a darn. I then got some SAC305, and was relieved to see it work almost as well as SnPb at its best! Much better wetting and flowing to the various
