Electronics Forum | Wed Sep 18 10:06:30 EDT 2002 | Bob M
I place 15-20 mil a lot. You need to look at your pad to apature reduction. Your stencil thickness. The type of paste your using. We use 2-5 mil reduction on each side as a general rule on fine pitch. This varies depending on pad width. We also use 5
Electronics Forum | Wed Sep 18 12:31:16 EDT 2002 | dragonslayr
My suggestion is to conduct a Design For Manufacturing (DFM)study on the assembly in question. Pay particular attention to the pad sizes, component lead dimensions and satisfy yourself that those two factors are correct. Given that pads match compone
Electronics Forum | Wed Nov 06 16:31:59 EST 2002 | slthomas
I would also consider paste control (don't take it personally...I always have to get after people about this one), time on the stencil, time between print and reflow, solderability of the component leads, paste volume (that one really got us once....
Electronics Forum | Thu Sep 07 09:08:57 EDT 2006 | Bubba
OK, part touching paste before reflow? Check part. Maybe bad plating. Check reflow profile by slowing conveyor.
Electronics Forum | Thu Sep 07 18:32:51 EDT 2006 | vicknesh28
Yes the part is reworked. It solders when it's reworked.
Electronics Forum | Tue Apr 17 09:19:11 EDT 2001 | Terry Burnette
Dave, I use Dexter Hysol epoxy 9340 gray. It's a two part epoxy kit. Thermally conductive and electrically insulative. Cures in about 10 minutes at 100C. Terry
Electronics Forum | Thu Sep 07 14:43:33 EDT 2006 | davef
Questions are: * So after you spot one of these leads sitting on a nice pillow of solder, what happens? * Do you rework the part? * Does it take solder? * What do you do to make it take solder, if it does take solder?
Electronics Forum | Thu Sep 07 07:41:06 EDT 2006 | Bubba
Check for coplaner leads if this just exists at reflow process, i.e. look at part before oven, turn on 3D at placement machine. If you see after wave solder, the wave could cause coplanarity issues on top as well if you are going slow enough to refl
Electronics Forum | Tue Sep 17 15:47:42 EDT 2002 | stepheno
Where I worked previously we had some boards with a couple 15 mil pitch parts. The first batch we got all had undersized pads. We had lots of bridging. We had less bridging with bigger pads. The ball size in the paste makes a bigger diffence regar
Electronics Forum | Wed Apr 11 14:05:30 EDT 2001 | davef
No, there's not a really great epoxy product for attaching thermocouples in reflow. Specifically, what's your problem? From Sanders Temprobe verbage ... Adhesives There are two general classes of material commonly used to adhesive bond thermoc
