Pad Sizes for 0402 Resistors and Resistors Are Much Larger than Actual Component
hoilett opened this issue · comments
I noticed the pad sizes for the 0402 SMD resistors and capacitors appear to be much larger than the components themselves and are much larger than recommended pad sizes provided in the datasheets. I was wondering why SparkFun decided to design them that way. I notice that I get quite a few components tombstoning or simply not connecting to the other pad because the designed SMD pad is so large. I figured it may have to do with some pick and place tolerance, but just curious. Anyone have any thoughts on this? Thank you.
Example 0402 SMD resistor: https://search.murata.co.jp/Ceramy/image/img/A01X/G101/ENG/GJM1555C1H8R2WB01-01.pdf
Thanks for noticing! As you may know we assemble quite a few of our products ourselves allowing direct feedback from our operators and assembly techs. In the case of the 0402 package types we found that we were getting consistent tombstones with industry-standard pad sizes. After attempting to troubleshoot the issues in the operations of our machines, trials were attempted with larger pads. With the larger pads we were able to consistently get better reflow on our line, and have started to use the larger pads on products where we see those issues occur.