After the part was sandblasted down to bare metal, [Thomas] masked off all the holes and threads of the part with polyimide tape. Any tape that’s capable of withstanding high temperatures will ...

Apparently [kbjunky] used polyimide tape to keep the solder from making blobs. It’s all there in the nice build guide.

by first attaching them to a polyimide film. The film is moved to the target location, and the leads are cut and soldered to the board. Also called a "tape carrier package" (TCP), the bare chip is ...