PCB Layout for Package Variants

Discussion in 'The Projects Forum' started by moneymcr, Feb 21, 2014.

  1. moneymcr

    Thread Starter New Member

    Mar 8, 2013
    3
    0
    I'm designing a PCB where I'm using a TE 40 pin FPC connector. Just in case this part becomes hard to find and buy, I want to design the PCB to accept an alternate part. However, finding a part that exactly fits the land pattern has been challenging. I have found several others that are close, but all of them have slightly different hold downs requiring slightly different land patterns.

    I'm sure this isn't a new question by any stretch, but how could I design the pattern to accommodate either part? Is it possible to simple make one pattern that is oversized to fit two slightly different connectors? Does this present a problem during assembly? Are multiple soldermask screens necessary?

    Thanks
     
  2. tracecom

    AAC Fanatic!

    Apr 16, 2010
    3,869
    1,393
    It is possible to combine two different part footprints into one. I have done it with a combination of a coaxial power input jack and a two connection terminal block. I created one of the part footprints and then the other; then, I created a third footprint that included both parts. The silk screen shows the outline of both parts, but only one is installed on the PCB.

    The degree of difficulty in doing this, of course, depends on the two parts involved.
     
    moneymcr likes this.
  3. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    If I was unsure of the future availability of a particular part I would try not to use it in the first place.

    Multiple solder paste screens are probably a good idea.
     
  4. moneymcr

    Thread Starter New Member

    Mar 8, 2013
    3
    0
    Thanks for the reply.

    The reason for the two sources is simply to make sure I have options down the road. If one ends up having a long leadtime, I'd like to swap it for the other.
     
Loading...