A method of processing greensheets for use as microelectronic substrates comprises providing a greensheet having a width, a length and a thickness, bonding to the greensheet, within the greensheet width and length, a frame adapted to constrain movement of the greensheet within the frame, processing the greensheet and bonded frame, and removing the frame from the processed greensheet. The processing of the greensheet and bonded frame may include punching vias in the greensheet, filling the vias in the greensheet with conductive material, patterning the greensheet by applying conductive paste to the vias and greensheet surface, stacking the patterned greensheet and bonded frame with at least one other patterned greensheet and bonded frame, and laminating the greensheets. The frame is preferably removed from the processed greensheet after laminating the greensheets, and before the laminated greensheets are subsequently sintered. The bonding of the frame to the greensheet may be by lamination or by an adhesive, or by other means. Preferably, the frame has a thickness less than the greensheet thickness. The frame preferably has a plurality of members subdividing the greensheet into a plurality of areas, with each area being completely surrounded by frame members. The frame may be applied to one side of the greensheet, and pressed into the greensheet side such that that the frame and greensheet side are substantially coplanar.