Electronics Forum | Wed Feb 05 21:24:35 EST 2003 | davef
Stephen's correct. Radiased outer corners on 0402 pads really do seem to improve things. We aim to try "squared-up semicircles".
Electronics Forum | Tue Apr 10 10:21:06 EDT 2018 | slthomas
Dave, that's a cool idea and sounds like something that would actually work. I'd be tempted to go with oversized pads to increase the holding force. Unfortunately as an EMS we would have to work that through the customer approval system and as usual
Electronics Forum | Wed Feb 22 10:00:58 EST 2006 | dougs
We've just set up a couple of products with 0.5mm pitch uBGA devices on them, i went for 5thou thick, laser cut nickel (to aid paste release) square pads same size as the diameter of the uBGA pads. Or you could go to a 4 thou nickel stencil, better
Electronics Forum | Mon Mar 20 10:54:36 EST 2000 | Glenn Robertson
Jack - The last time I checked IBM was specifying a minimum of 4800 cubic mils of paste for each pad. This is required for acceptable reliability, not just to make the connection. There is no way you are getting that volume with a 5 mil stencil
Electronics Forum | Tue Feb 04 09:03:45 EST 2003 | Russ Roberts
Greetings, I am pretty new to SMT production, and have learned much from this forum. I am getting ready to build a CCA with many 0402 parts that are really close together. I consider these fine pitch. The board also has two QFPS, so my stencil design
Electronics Forum | Tue Feb 04 22:28:16 EST 2003 | davef
You could reduce the paste by about 70%. Solder balling and tombstoning will be the issues to fight. The drivers to these don't change with the component size. Use the fine SMTnet Archives for background. Aperture Size and Thickness of Solder Pas
Electronics Forum | Fri Dec 27 14:11:18 EST 2002 | cnotebaert
We have placed these parts. I have not had problems with them but when I designed the stencil we reduced the app for the large thermal by 20% to reduce the chance of problems like your having. If the balls are close (.040-.050" or
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 | Mon Oct 21 23:48:13 EDT 2002 | harris
Hi: If anyone have the experience with the PCB pad design and stencil design for the uBGA? We meet the problem for it. The component data is 0.3mm diameter and 0.5 pitch. Could anyone tell me the PCB pad dimension, the stencil type and aperture dimes
Electronics Forum | Tue Feb 01 04:11:58 EST 2000 | emmanuel
I am to assembly a power SO on the top side of a double side board. My designer has implemented a lot of thermal vias in the heat sink pad of this component. The problem is that i need to prevent the solder cream from polluting the bottom side of the
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