Method for electrically testing a semiconductor die using a test apparatus having an independent conductive plane

A method for adjusting a characteristic impedance, comprising the steps of:

• providing a tape carrier for a semiconductor die, the tape carrier comprising a film having a first major surface, a second major surface, a region for receiving the semiconductor die, and a plurality of conductors on the first major surface, each of the plurality of conductors having a first end projecting to the region for receiving the semiconductor die, a central portion, and a second end projecting away from the region for receiving the semiconductor die;
• providing the semiconductor die, the semiconductor die having a first major surface and a plurality of bonding pads on the first major surface;
• bonding the first end of each of the plurality of conductors to at least one of the plurality of bonding pads;
• providing an independent conductive plane, the independent conductive plane having a first major surface and a second major surface wherein the independent conductive plane is separate from the tape carrier and is a removable portion of a test apparatus;
• coupling the independent conductive plane with the central portion of the plurality of conductors;
• electrically testing the semiconductor die;
• and
• de-coupling the independent conductive plane from the central portion of the plurality of conductors wherein the independent conductive plane remains with the test apparatus.