Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?
Excessive dielectric loss
Epoxy coating is conductive above 300 MHz
Excessive lead length✓Bonne réponse
Unsuitable for combining analog and digital signals
Explication
The pins and internal bond wires of a DIP are long enough to add series inductance and stray capacitance that become significant at UHF, detuning circuits and eating gain. The epoxy body remains an insulator at those frequencies, and DIPs are freely used for mixed analog and digital parts at lower frequencies.