System, method, and apparatus for dynamic electrical testing of workpieces by multiplexing test sites with shared electronics

A system for dynamic electrical testing of head gimbal assemblies (HGA), the system comprising:

• an array of modular spin stands for testing HGAs, each of the modular spin stands having a preamp, a piezo controller, and a spindle;
• a first read/write analyzer (RWA) that is shared by, multiplexes, and buffers between a first pair of the modular spin stands for simultaneously testing HGAs on both of the modular spin stands of said first pair;
• a second RWA that is shared by, multiplexes, and buffers between a second pair of the modular spin stands for simultaneously testing HGAs on both of the modular spin stands of said second pair;
• a plurality of processors for operating the array of modular spin stands and the first and second RWAs;
• and
• a controller for controlling all of the modular spin stands.

A method of dynamic electrical testing of workpieces, the method comprising:

• (a) providing fixtures for supporting workpieces, each of the fixtures having a preamp and a piezo controller;
• (b) sharing a single electronic analyzer with and buffering between all of the fixtures for simultaneously testing workpieces distributed among all of the fixtures;
• (c) multiplexing the fixtures by combining and sending several signals to the single electronic analyzer while testing the workpieces;
• and
• (d) demultiplexing the single electronic analyzer by separating multiplexed signals from the fixtures.