Invention patents suit circuit architectures, manufacturing methods and process improvements that can be reverse-engineered from the product itself. Disclosure buys a 20-year exclusive right, and this remains the primary line of defense.
Layout design rights suit the specific three-dimensional configuration of a layout. They are cheap to obtain and need no substantive examination, and they fill the gap patents leave around the physical layout itself. Registration must be filed within two years of first commercial exploitation.
Trade secrets suit process parameters, yield-tuning know-how, test methods and design toolchains that are hard to reverse-engineer from the product. There is no time limit, but protection depends on maintaining reasonable confidentiality measures without interruption; once the information leaks and no such measures were in place, there is little remedy.
On timing: settle the patent filing strategy and the trade secret classification before tape-out; and complete the layout design registration within two years of tape-out and shipment; and put confidentiality agreements and IP ownership clauses in place before any external collaboration — foundry, packaging and testing, or IP licensing.
