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I'm interested to know if there are real-world measurement values available for the resistance contribution of vias (or plated through holes).

Sure - there is no widespread definition of what a standard PCB actually is.

To make the an answer useful not just for me imagine your preferred PCB manufacturer with it's default design parameters would provide the PCB (one of mine would be multi-cb for instance).

Anyway, let's make the following assumptions:

  • standard FR4 2-layer PCB with 35µm of copper (1 ounce per square foot), maybe 1 square inch in size
  • the via in question connects the two copper planes in the centre so the resistance of the plane is low compared to the via
  • by depth of via I understand the thickness of the base material, which such as (1.5, 0.8, 0.5) mm
  • the diameter of the via varies such as (0.2, 0.25, 0.3, 0.4, 0.5, 0.7, 1.0, 1.5, 2.0) mm

The question came up while pondering more and more often about optimization possibilities of space-sensitive PCBs in the environment of charging and protection circuits of Li-ion batteries, especially when considering how many stitching vias with which diameter would be the best choice in terms of lowest resistance and also lowest board area.

If a universal answer can be found, it could certainly be useful to many aspiring PCB designers.

Although my question is primarily about DC resistance, I'm not sad if the answer happens to describe the impedance contribution of vias.

Edit: replaced "PTH" with "via" everywhere

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  • \$\begingroup\$ This is a DC question, correct? You have everything you need, current, copper, temp-rise, dimensions & math. Get to it... If it's a high frequency (or fast rise-time) question, then more specs are needed. \$\endgroup\$
    – Chris Knudsen
    Commented Dec 23, 2022 at 20:13
  • \$\begingroup\$ Yes, it's more a DC question, maybe extendet for inductance. I know how to calculate it in principle with more or less inaccurate simplifications. But I suspect real-world PCB will have more influences as I know and therefore ask for messured data. We could compare those with calculated values later... \$\endgroup\$
    – datenheim
    Commented Dec 23, 2022 at 20:44
  • \$\begingroup\$ In his answer @Bruce Abbott contributed rough measured values for 0.33mm via of 0.5 mΩ and 1.0mm via of 0.1 mΩ on a 1.6mm 1oz board. \$\endgroup\$
    – datenheim
    Commented Dec 24, 2022 at 12:12
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    \$\begingroup\$ I suspect a more detailed answer (beyond copper plating weight vs via length) is going to depend on intricate details of how your specific factory plates through holes and how uniform that copper layer ends up. \$\endgroup\$
    – user1850479
    Commented Dec 24, 2022 at 15:53
  • \$\begingroup\$ I hope to collect enough responses to finally assemble a table of via resistance vs. via diameter and via depth, each with calculated and reported min-average-max values from multiple manufacturers to gain wider understanding of via resistance in general. \$\endgroup\$
    – datenheim
    Commented Dec 25, 2022 at 11:10

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