Semi-mechanical

Semi-mechanical is an imprecise term used to describe switch technology that is a hybrid between "mechanical" (as in, discrete metal contact switch modules) and all-plastic membrane arrangements.

The two best-known types are Tai-Hao APC semi-mechanical (where "semi-mechanical" is the term that Tai-Hao themselves use) and the Acer switch. The Acer switch does have discrete modules in a manner similar to most foam and foil switches, where the modules are still dependent on an external component for sensing. APC semi-mechanical is non-discrete: the top case of the keyboard holds the switch components.

The fact that IBM membrane buckling spring falls under this classification but is widely considered to be fully mechanical demonstrates how poorly defined these terms are.