Electronics Forum | Wed Oct 09 16:59:35 EDT 2002 | davef
Russ, as I told Eric the other day ... The steadfast rule of thumb is: In order to get reliable reflow, you need to be at or higher than [liquidus + 20�C] for about 5 to 10 seconds, rather than those old "60 seconds above 183�C" guideline. This prov
Electronics Forum | Wed Oct 09 20:52:27 EDT 2002 | davef
Russ, Be careful on how you determine your liquidous point. Sure 205-210�C is fine if your paste and the solderability protection on pads and component leads are near eutectic solder and things worked according to plan, but in real life it doesn't
Electronics Forum | Sat Oct 19 11:48:39 EDT 2002 | davef
Good points, John. Continuing to track on the voiding issue, why remove voids anyhow? * Voids are primarily process indicators. There is experimental evidence that voids retard crack propagation locally around the void on at least on a temporary bas
Electronics Forum | Wed Oct 23 14:45:00 EDT 2002 | Tom G
I haven't tried anything like that but had some experience with .8 mm pitch SSOPs. Immersion depth in wave was very critical- had to control Lambda pump speeds within 20 RPM and even then it would change as solder level dropped. Need thieving pads o
Electronics Forum | Tue Oct 01 16:33:33 EDT 2002 | slthomas
I know, I know. It's not a "solution", per se, because it's a bandaid for bad fabrication, packaging, and storage practices. Still, it's a reality with our overseas CM that has a plant in a very humid environment. Is 16 hours @ 105C the safe way to
Electronics Forum | Tue Oct 01 20:56:48 EDT 2002 | davef
Hey Steve, You shouldn't bake your boards, because it's a bandaid for bad fabrication, packaging, storage practices, and what not. You really should go back to the source of the problems and fix that so that you don't add non-value-added costs to
Electronics Forum | Wed Oct 02 11:29:05 EDT 2002 | slthomas
Yeah, like I haven't been hearing that for the last two months. Hey, Steve, got a passport? Hey, Steve, you like chinese food? Hey, Steve, let me know if Xiamen is really just like San Diego! :P I found some other stuff on Technet (courtesy of Jac
Electronics Forum | Wed Oct 02 12:06:59 EDT 2002 | dragonslayr
Scott - all sounds good. My primary concern is the residual flux left behind under the BGA. Will moisture entrapment become a concern over time? I believe that may be dependent on the flux formulation. I know that some no clean fluxes actually become
Electronics Forum | Wed Oct 09 08:56:42 EDT 2002 | pjc
If I understand your question: I've done this before by creating a spreadsheet in Excel. All the data you're looking for can be built into said spreadsheet. I don't think you'll find a "canned" package with the values without buying a bigg-ass prgram
Electronics Forum | Thu Oct 03 15:14:46 EDT 2002 | SMTGuy
Good Day Everyone, Can anyone offer any advice on 0201 aperture design? We are looking at an application that will require them. We would like to do some experimentation first. Also, assuming an OA flux, would we need a type 4 or 5 powder paste to p
