Abstract: Reformation of a round tube to a tube with a selected polygonal segment is achieved by supporting the round tube on a mandrel having rounded corners that mate with the tube's inside diameter. The mandrel is otherwise provided in the resultant polygonal shape. The supported tube is subjected to the compressive force of a die having upper and lower die sections that define an elongated polygonal cavity. The planar sides of the cavity are offset relative to the parting line. Preferably, the corners of the cavity adjacent the parting line are wrapped by a leg of the die section. Upon closure of the die sections, the tube material is allocated to a particular quadrant by contact with the die section and the tube is reformed. Excess material that may result from tolerance permitted variations is delivered to the corners of the polygonal tube section maintaining uniform wall thickness across the flat sides of the reformed tube.

Abstract: A process for fabricating a semiconductor device is enhanced by providing a plasma etching process in which exposed metal surfaces within a plasma etching chamber (24) are protected by a ceramic layer (46). In the plasma etching process, a substrate (10) is placed on a platen (26) located within a plasma etching apparatus (22). A clamping device (40) secures the perimeter of the substrate (10) to the platen (26). The clamping device (40) includes a ceramic layer (46) overlying a metal base (44). When a plasma is ignited within the etching chamber (24), the ceramic layer (46) prevents physical contact of the plasma and the metal base (44) of the clamping device (40).