Royalty rate stacking refers to the phenomenon that high technology product may require the paying of multiple royalties to multiple licensors; the result is that the royalties can ‘stack-up’ to a very significant total rate. Royalty rate stacking is, probably unwisely not one of the Georgia-Pacific Factors though an argument can be made that considering royalty rate staking penalizes later licensors over earlier licensors.
Stacking can also refer to the overall impact of license royalties once all the input manufacturers royalties are taken into account, for example manufacturers of machinery, purified silicon, etc. are taken into account, sometimes described as royalties “from sand-to-silicon.” Many such supplier-royalties are invisible to the final consumer product manufacturer.
In semiconductors stacking can refer to placing multiple semiconductor dies in a single package.