A probe card assembly comprises multiple probe substrates attached to a mounting assembly. Each probe substrate includes a set of probes, and together, the sets of probes on each probe substrate compose an array of probes for contacting a device to be tested. Adjustment mechanisms are configured to impart forces to each probe substrate to move individually each substrate with respect to the mounting assembly. The adjustment mechanisms may translate each probe substrate in an “x,” “y,” and/or “z” direction and may further rotate each probe substrate about any one or more of the forgoing directions. The adjustment mechanisms may further change a shape of one or more of the probe substrates. The probes can thus be aligned and/or planarized with respect to contacts on the device to be tested.