Abstract: A substrate is provided for a probe card assembly. The substrate includes an interconnection layer including a first surface having a first electrode set and a second surface having a second electrode set electrically connected to the first electrode set. The substrate further includes a base layer including a first surface having a third electrode set electrically connected to the second electrode set and a second surface having a plurality of contact terminals electrically connected to the third electrode set. And the substrate further includes a resin layer including a plurality of sublayers made of different materials. The resin layer is attached to the first surface of the base layer and the second surface of the interconnection layer.

Abstract: A method of manufacturing a substrate for a probe card assembly comprises preparing an interconnection layer, preparing a resin layer and preparing a base layer. The method comprises attaching the resin layer to the interconnection layer by a first thermal process at a first temperature. The method comprises attaching the resin layer attached to the interconnection layer to the base layer by a second thermal process at a second temperature higher than the first temperature.

Abstract: A balancing apparatus includes a frame body (1), a first weight (2) and a second weight (3) separated from each other vertically in the frame body (1). The first weight (2) is connected to the frame body (1) through elastic bodies (41, 42). The elastic bodies (41, 42) are always subjected to compression load. The first and second weights (2, 3) are accommodated together in the frame body (1). Since tensional load is not applied to the elastic bodies (41, 42), the durability of the balancing apparatus can be ensured.