Probably. But power transistor mask layout isn’t rocket science. At least for stuff this basic. If the process is different enough having the other maker’s mask set won’t do you any good either. Jellybean transistors and op amps, digital logic and such - if your process has a similar FLOW through the line, and makes devices which are good enough, then you could use the mask set. You still get different flavors of say the 5532 op amp from the different makers. Like the original Signetics beat everybody’s. But most were good enough to use industry wide.I know that with common ICs, mask exchange agreements became the norm but was that done at the single transistor level of did each manufacturer design their own version of the 2N3055 from the ground up?
Cheers
Ian
The MJL3281 does NOT use the same mask set as the 2SC3281. The die is about 25% larger. Don’t believe me? Crack them open and see. And the capacitances do measure more. They made it as big as the 15024, probably (speculation here) because their equipment was tooled up for it and they wanted it to handle as much power as they could. Their competition was Sanken, and you know what their LAPTs can take. It’s still the same shootout today (and I still think Sanken shot themselves in the foot by discontinuing the MT200 package giving the advantage back to ON). What they acquired from Toshiba was the recipe, or at least some of it. The die layout is trivial by comparison.