If capacitors are just two conductive components sandwiching an insulator, then why aren't all PC board, or at least their traces, considered capacitors?
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2See Parasitic Capacitance (Wikipedia). Also related questions: http://electronics.stackexchange.com/q/56574/2028, http://electronics.stackexchange.com/q/98372/2028 – JYelton Feb 05 '14 at 04:24
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who said PCBs weren't like caps? they simply exhibit a very low non-uniform capacitances – hassan789 Feb 05 '14 at 04:29
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They are, but only noticeable in very high frequencies (microwave wavelength or GHz).
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That depends on applications, some smaller frequency circuits, in boards that have high length traces should consider the capacitance of the traces. – Diego C Nascimento Feb 05 '14 at 04:04
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3If by very high frequencies you mean a few hundred kilohertz. High Trace/Bus capacitance can cause issues in even low speed 100khz i2c for example. – Passerby Feb 05 '14 at 04:32
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On a multi-layer board, I think internal power and ground planes can have useful values of capacitance. – Peter Bennett Feb 05 '14 at 07:17