ePIC pfRICH electronics mailing list

["Kiselev, Alexander" <ayk AT bnl.gov>]

  Hello colleagues,

  we received the interposers (see a tray picture attached), and also one Kyocera HRPPD anode for "evaluation". Trace resistivity inside of the ceramic stack is hard to measure with the available equipment, without damaging the pads, but it is ~1 Ohm, at most, so not inconsistent with the expectations. 

  Pad+trace capacitance to ground is 4-7 pF, depending on the trace length. This is a tick too high, compared to what was expected. One obvious reason is usage of a proprietary HTCC technology, with a ceramic dielectric constant ~10 as compared to 7-8 in case of LTCC with its DuPont 951 green sheets. But I recall also the pad to ground distance in Kyocera stackup is somewhat smaller than it used to be in the first plates built by Techtra. Anyway, we should be able to beat the number down to <5 pF in the second (and final) iteration of the anode design, but for now it is what it is.

  Capacitance between two neighboring pads is not really measurable with my DVM. It is of an order ~1pF or smaller. 

  Regards,

    Alexander.

 

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