Electronics Forum | Fri Mar 02 16:26:57 EST 2007 | Steve
1- Thickness 0.005" 2- I usually reduce 50% of the thermal pad, but it also depend on original size of thermal pad somehow I have to either create window panel or crosshatch otherwise component wil get wimming during reflow. Hope this will help. Reg
Electronics Forum | Fri Apr 25 12:36:52 EDT 2008 | fsw
All, Does anyone on the forum have experience with underfill? We have a component with QFN pkg on one of the new products. It has a thermal pad in the centre. Customer wants this component to have an underfill. Questions - 1) Does one normally req
Electronics Forum | Tue Mar 28 08:29:04 EST 2006 | davef
Pad design - Standard IPC 20 pitch QFP Thermal pad design - Layout the thermal pad 0mm to 0.15mm larger per side (0mm to 0.30mm larger overall) than the exposed die pad on the package. �Larger than�, as opposed to the same size, is preferred. Obvio
Electronics Forum | Thu Sep 16 17:56:48 EDT 2010 | asksmt
Ok Thanks, i have reduced thermal pad size by 4.5 mils on top and bottom part of this footprint where the problem was occuring, so now the clearance between thermal pad and lead pads are 12 mils instead of 7.5 mils on two sides. (i kept the signal pa
Electronics Forum | Tue Nov 26 09:05:48 EST 2019 | scotceltic
Thank you for the response. Nothing in the datasheet referring to a percentage of thermal pad coverage. I am thinking along the same lines. We are not failing any thermal or functional testing as is so am thinking there is no problem here except m
Electronics Forum | Tue Sep 14 17:06:25 EDT 2010 | asksmt
Hi All, I have designed 4 Layer PCB with one 28 pin QFN PKG. I have got complaint from Production that the pads which connected to thermal pads (gnd) thru trace is bridging with solder and because of this bridge, pins are not getting soldered prope
Electronics Forum | Tue Nov 09 04:21:11 EST 2010 | bising
Hi SMT World, I am facing a technical challenge related to an SOIC 14lds with thermal pad on it's belly that needs to be soldered onto PCB, together with leads. It is a 50 per board, expected 80% solder load on every one. We have some units without
Electronics Forum | Fri May 09 08:27:35 EDT 2014 | emeto
REduction of center pad is the key as well as the stencil thickness. Having too big opening on your stencil will sometimes lift the part from the pads. Always try to make windowpane and shoot for about 60% of the thermal pad to be covered as start p
Electronics Forum | Fri Jun 21 02:11:27 EDT 2019 | alanyang
Many aspects cause such problem, stencil windows and thickness, thermal pad and crowded PTH vias on PCB, the castellated pad size and pcb pad size. Do you have picture for reference?
Electronics Forum | Sat May 18 10:21:09 EDT 2013 | davef
isd.jww: Comments are: * Current thinking has flux volatiles being the major contributor to voiding, not scavanging by via * I have no reason to think that 0.3mm via won't gladly accept solder. Plug them, if that's a concern. * If your concern is ina
