US 6,686,993 B1 · Probe card for testing optical micro electromechanical system devices at wafer level

Abstract

A probe card characterizes optical structures formed on a MEMS wafer. The probe includes a substrate having a circuit thereon. The substrate has an opening wherein a plurality of metal probes, electrically coupled to the circuit, pass through the opening. The probe card further includes an optical test device electrically coupled to the circuit. The optical test device includes a light source and a photosensitive area. The photosensitive area receives directly light reflected from the optical structures. The optical test device can be positioned directly over the opening, or the optical test device can be positioned on a periphery of the opening. Furthermore, the optical test device can be positioned so as to provide a test light beam that is parallel to the wafer to test pop-up optical MEMS components. The optical test device also may be positioned between the probe card and the MEMS wafer.

Claims43

Dependent claims

A probe card for characterizing optical structures formed on a wafer, comprising:

a substrate having a circuit thereon, said substrate having an opening therethrough;
a plurality of metal probes being electrically coupled to said circuit and passing through said opening;
and
an optical test device being electrically coupled to said circuit;
said optical test device including a light source and a photosensitive area;
said photosensitive area receiving directly light reflected from the optical structures.

3 more elements

A probe card for characterizing optical micro electromechanical system devices, having a plurality of mirrors, formed on a wafer at the wafer level, comprising:

a substrate having a circuit thereon, said substrate having an opening therethrough;
a plurality of metal probes being electrically coupled to said circuit and passing through said opening;
and
an optical test device being electrically coupled to said circuit;
said optical test device including a light source and a photosensitive area;
said photosensitive area receiving directly light reflected from the optical structures;
said circuit activating individual mirrors through said metal probes;
said metal probes being electrically coupled to pads on a die having the optical micro electromechanical system devices located on the wafer;
said circuit causing individual mirrors to be positioned at different predetermined angles;
said optical test device measuring light from the light source reflected from the angled mirror with the photosensitive area;
said circuit characterizing a functionality of each individual mirror based upon a measured output of the photosensitive area.

8 more elements

A method for characterizing an integrated circuit having optical micro electromechanical system devices, including a plurality of mirrors, formed on a wafer at the wafer level, comprising:

(a) testing an integrated circuit with a probe card, the probe card making electrical contact with the integrated circuit to test electrical functionality, the probe card including a substrate having a circuit thereon, the substrate having an opening therethrough and a plurality of metal probes being electrically coupled to the circuit and passing through the opening;
(b) testing the optical micro electromechanical system devices with the probe card, the probe card further including an optical test device being electrically coupled to the circuit, the optical test device including a light source and a photosensitive area, the photosensitive area receiving directly light reflected from the optical structures;
said testing the optical micro electromechanical system devices with the probe card including:
(b1) activating individual mirrors to be positioned at different predetermined angles, and
(b2) measuring light from the light source reflected from the angled mirror with the photosensitive area;
and
(c) characterizing an optical functionality of each individual mirror based upon a measured output of the photosensitive area.

4 more elements