Patent ID: 8004296

Claim:
A probe head for contacting microelectronic devices substantially lying in a test plane, the probe head comprising: one or more substrate tiles having one or more probe tips disposed on a top surface thereof; and a registration-alignment apparatus that holds the one or more substrate tiles: (a) in position so that the one or more probe tips are held in registration in the test plane, and (b) aligned so that the one or more probe tips are substantially coplanar to the test plane, which registration-alignment apparatus comprises: one or more capture elements affixed, directly or indirectly, to a frame and the substrate tiles to provide the registration in the test plane; three or more posts mechanically supporting at least one of the one or more substrate tiles; and alignment actuators affixed, directly or indirectly, to the frame and the posts, which alignment actuators may be actuated to enable the posts to move and align in response to forces applied thereto from the one or more substrate tiles, and may be actuated to prevent the posts from moving; wherein: the alignment actuators for the three or more posts comprise hydraulic reservoirs connected by fluid channels; and the probe head further comprises a valve apparatus that can be opened or closed to fluid flow in the fluid channels from any hydraulic reservoir to any other hydraulic reservoir.