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AWR1642BOOST: Antenna processed thickness on EVM

ej99
Intellectual 640 points

Part Number: AWR1642BOOST

I am designing a PCB using the same antenna layout as the EVM, and I would like to know how thick the finished antenna needs to be in order to work properly.

The EVM documentation states that the base copper is 0.5oz (0.7mil). However, the processed thickness could be higher, due to the step to plate the via holes and the step to cover the vias with copper. Additionally, there is the silver immersion finish, but I don't think that would add very much thickness.

Can you tell me what the finished thickness for this antenna should be?

  • 0
    TI__Guru**** 153284 points
    Hi,

    The schematics are provided on the EVM product page.

    Is this information not sufficient?


    Thank you
    Cesar
  • 0 in reply to Cesar
    Intellectual 640 points

    The stackup description indicates 0.5 oz base copper thickness and 2.067mil processed thickness. I also read in the documentation somewhere that filled and plated-over vias were used.  I am looking for more details on the fabrication process. Specifically, what via plating  thickness was used and whether or not a via covering (or button plating) step was applied to the antenna region. Depending on whether the antennas are masked out in the covering step, the thickness could be different than 2.067mil.

    Since my original post, I measured the antenna copper thickness to be about 2.4mil. It would still be helpful to know the fabrication steps that were used on the EVM boards to confirm that my boards will end up with similar thickness for the antennas.

  • 0 in reply to ej99
    TI__Mastermind 18770 points

    Hi ej99,

    I can look into this for you. Please give me a few days. Also, what method did you use for measuring the L1 copper thickness?

    Thanks,
    Randy

  • 0 in reply to Randy Rosales
    TI__Mastermind 18770 points
    Hi ej99,

    There is no additional mask applied to the final plating step. So the quoted final applies to the entire L1 layer, including the RF sections.

    Thanks,
    Randy
  • 0 in reply to Randy Rosales
    Intellectual 640 points

    Thanks for checking on this. To answer your previous question, I measured the antenna thickness with a micrometer, comparing the thickness of a section of the board near the antennas with no copper to the board thickness at an antenna. Based on what you said and the stackup documentation, it seems that the extra thickness of about 0.3mil at the antennas is due to faster plating rate on the narrow antenna structures.