I have a board that contains a WiFi module (2.4GHz). Does Tg have an effect on RF performance in any way ?

If the material can satisfy the other constraints, such as Dk, Df etc.. would the Tg be a factor in material selection for RF ?

I should note that this is a relatively high volume unit so it's extremely cost-sensitive.

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    \$\begingroup\$ is your application one in which the glass transition temperature seems relevant? \$\endgroup\$ – Marcus Müller Nov 17 '20 at 13:23
  • \$\begingroup\$ It def isn't but don't know if there are other parameters that would be associated with a higher Tg. My Asian cm says go with 130degc but North American shop uses isola 377hr which has a tg of 170 degC. \$\endgroup\$ – efox29 Nov 17 '20 at 13:33
  • \$\begingroup\$ well, that's not how specs work, luckily: You know which properties matter, and then you check the datasheet of the board substrate whether they are given for your operational range. All other parameters do not matter – whether they are Tg, or density, or color, or taste, or usability as cutting board for carrots ... ;) \$\endgroup\$ – Marcus Müller Nov 17 '20 at 13:35
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    \$\begingroup\$ I'd ask your Asian manufacturer to supply you with the datasheet of the substrate that they will guarantee to use. For RF stuff, you don't want them to switch to something with slightly differently epsilon (even just slightly different isotropicity in epsilon) between production runs. \$\endgroup\$ – Marcus Müller Nov 17 '20 at 13:45
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    \$\begingroup\$ well, you change the epsilon and suddenly your transmission lines have a different impedance. That changes what your board does. \$\endgroup\$ – Marcus Müller Nov 17 '20 at 13:49

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