transistor isolation pads / washers

[Kenneth Li]

Hi, there,

I was wondering if anyone know where I can some isolation pads and
associated washers / caps to mount transistors and large power chips to
heatsinks. I know that digikey sells them but their offerings are limited
for the most part to to220. I have some irregular shapes to deal with
(multiwatt 11, 15, to3p, and gbpc bridges for example).

Thanks in advance.