1 Reply Latest reply on Nov 11, 2010 11:43 PM by marc.england

    ODB++ output of solder and paste mask




      I´ve posted it here because I don´t know whether it is something like an enhancement and should be on Mentor Ideas or it is a bug or something in between. Maybe you can direct me to the right people.


      since PADS V9.1 there is an ODB++ output. Here some questions / issues on it:


      - in the ODB++ output there is no way to include solder and past mask that is calculated from the padstack. So if you don´t have defined solder and past mask within the padstack you can´t output a solder and past mask.

      - for PADS gerbers you have different ways to generate solder and paste masks. One of this ways is to define over and undersize for that layers by attributes. Is there a way to include that over- / undersize for solder and paste mask generation in the ODB++ file?

      - some parts needs a very special paste mask. So that past mask is drawn manually and added to the padstack on e.g. past mask top. All other decals don´t have a graphical paste mask definition. The past mask is defined by over- / undersize attributes. How can I bring both together into the ODB++ file to make a correct past mask file? In that special customer case all parts with a defined paste mask in the padstack gets paste all other parts didn´t get.


      In that special case the customer changed his whole library by deleting all padstack definitions for paste and soldermask and replaced them by over-/undersize attributes. Only special, not defineable past masks still are done graphically within the padstack - e.g. 4 little squares for a big pad. Now there is no way to get an ODB++ file that represents the wanted past mask.


      The question is

      - is it possible to include these things into ODB++

      - is ODB++ designed to support such things or is it made to only bring the data as it is into a CAM tool (like CAMCAD)  and then lets do all the oversize stuff in the CAM-Tool





        • 1. Re: ODB++ output of solder and paste mask

          Have a look at some of the IPC-7531 stuff and Prof Toms corner for more detail, but:

          These days it is reccomended and common npractice to output both the solder mask and solder paste appertures as 1:1, any oversizing done by the PCB manufacturer for the solder mask, any reduction done by your screen manufacturer for the solder paste. This allows your library to cover different levels of PCB design etc and different thickness of screens for solder paste. I would strongly recomend using the IPC-7351 procedures, especially as Mentor now owns PCB Libraries so you have access to all the tools and information.