Universal clamping fixture to maintain laminate flatness during chip join
A clamping apparatus and method for maintaining a workpiece flatness during processing includes a base having a planar surface for receiving a first workpiece. Two sets of opposing clamping mechanisms are mounted to the base and include a clamp head at a distal end of a rod extending from a housing in removable overlapping relation to the first workpiece. Each set of the clamp heads are in opposing spaced relationship to each other defining a second workpiece area, and the clamp heads are configured to mate with a top surface of the first workpiece. A biasing member is coupled to each of the housings and apply a downward vertical force to the housings, rods, and the clamp heads for applying a downward vertical pressure to the first workpiece. The first workpiece is thereby discouraged from thermally expanding in a vertical direction and is thermally expandable horizontally along the planar surface.
1. A method for maintaining a workpiece flatness during processing, comprising:
receiving a first workpiece on a base having a planar surface;
positioning a second workpiece between two clamping mechanisms mounted to the base and each clamping mechanism including a clamp head at a distal end of a rod extending from a housing configured to be in overlapping relation to the first workpiece, wherein the second workpiece comprises a die, each of the clamp heads extending below the rod, and being in spaced relationship to each other defining a second workpiece area for receiving the second workpiece, and the clamp heads being configured to mate with a top surface of the first workpiece and wherein each clamp head is located along an edge of the die; and
applying a downward vertical pressure to the first workpiece using a biasing member including a spring washer coupled to each of the housings, the biasing member communicating with the rods via the housings wherein the downward vertical pressure is transmitted only by the clamp heads via the housings and rods such that the first workpiece is discouraged to thermally expand in a vertical direction with respect to a horizontal plane defined by the planar surface and is thermally expandable along the horizontal plane.