9 Replies Latest reply on Apr 18, 2018 12:07 AM by d_circuitt

    Solder Mask Defined pads or Non Solder Mask Defined Pads?

    d_circuitt

      Hi All

       

      I'm currently in the process of looking to update our symbol library and wondering if to use solder mask defined (SMD) pads or non solder mask defined (NSMD) pads. There is plenty of advice that sways towards NSMD for BGA's but when it comes to 0402 and 0201 chip packages there is little advice, so I'm asking what would you do and why?

       

      My concern with these smaller components and using NSMD pads is if on one end it was part of a copper area and a single track leaving the other, once the solder mask aperture is increased by the manufacturer then one pad is going to be a lot larger in terms of copper than the other; for larger components then this would cause little issue but the smaller packages mentioned then this increase could become an issue with reliability, etc.

       

      Any help or pointers would be a great help!

       

      Thanks

       

      Danny