Micromachined semiconductor probe card

A method of manufacturing a probe head for semiconductor integrated circuit (IC) test equipment wherein the probe head contacts an array of electrode pads formed on a semiconductor IC to transmit an electric signal to external test circuitry, the method comprising the steps of:

• providing a semiconductor substrate;
• forming a plurality of probe tips on a top surface of the substrate, wherein the probe tips are arranged in an array matching that of the electrode pads;
• forming a conductive interconnect on the semiconductor substrate for coupling each of the probe tips to external test circuitry;
• thinning a portion of the semiconductor substrate surrounding each probe tip so that the thinned portion becomes flexible;
• and forming a well over each probe tip, wherein the well has sloped sidewalls and the probe tip is recessed within the well.

A method of testing an unencapsulated integrated circuit comprising the steps of:

• providing an integrated circuit having an array of electrode pads for communicating with a tester;
• forming an self-aligning semiconductor probe card having an array of spring mounted probes, wherein the array of probes corresponds to the array of electrode pads;
• placing the integrated circuit on the semiconductor probe card so that the electrode pads are in rough alignment with the spring mounted probes;
• vibrating the semiconductor probe card to fine-align the array electrode pads with the array of probes, thereby contacting the array of electrode pads with the array of probes;
• pressing the integrated circuit and the semiconductor probe card together, thereby deforming some of the spring mounted probes to compensate for dimensional variations in the electrode pads, integrated circuit, and semiconductor probe card;
• and electrically testing the circuit.

A probe fixture for testing an unencapsulated integrated circuit comprising:

• a semiconductor substrate;
• a plurality of cavities etched int he semiconductor substrate;
• a plurality of flexible beams formed from said substrate, each beam having a first end attached to the substrate at an upper portion of each cavity, and a second end extending over a portion of each of the cavities;
• a plurality of conductive probe tips, each probe tip is formed on one of said beams and a conductive interconnect formed on the substrate for coupling each probe tip to an external circuit tester.