Hot embossing tooling with integrated heating/cooling fluid channels and method

Abstract

An electroformed tool has an integrated base with channels contacting the tool with heating and cooling fluids flowing through the channels during injection molding or hot embossing. A blank base is machined with a network of interconnected open channels on a top surface and end flow through passageways communicating with the channels. The tool is used as an electrode to erode the top surface of the blank base using plunge electro discharge machining by lowering the uneven deposit on the bottom of the electroformed tool down onto the top surface of the blank base in the electro discharge machining environment to form a top contoured surface to mate with the uneven deposit on the non-embossing side of the substrate. The tool and base are sealed together.

1 . An electroformed tooling device with integral heating and cooling fluid channels for use in injection molding and/or hot embossing, the device comprising:
 an electroform, an electroformed tool comprising electrodeposited metal which has been plated from a structured substrate on an embossing side to function as an embossing surface and an uneven contour on a non-embossing side of the electroform left as a by-product of electroforming;   a blank base comprising a smooth flat bottom surface, a top surface having a network of open channels in the top surface, and one or more surfaces having openings therein communicating with the network of open channels to allow fluid to flow into a first opening and flow through the network of open channels and flow out a second opening, the top surface further comprising a an electro discharge machined contoured surface to mate with the uneven deposit on the non-embossing side of the substrate;   wherein the electroformed tool and the blank base are interconnected by a means of securing the electroformed tool to the blank base with the non-embossing side of the electroform contacting and mating with the mating top contoured surface of the blank base to form an electroformed tool with integral heating and cooling channels so that hot and cold fluid flowing through the blank base network of open channels contacts the electrodeposit to alternately heat and cool the electroformed tool during use in injection molding and/or hot embossing processes.   
   
   
       2 . The device of  claim 1  wherein the means of securing the electroformed tool to the blank base comprises a liquid-tight structural adhesive. 
   
   
       3 . The device of  claim 1  wherein the means of securing the electroformed tool to the blank base comprises a threaded fastener and a sealant for a watertight device. 
   
   
       4 . The device of  claim 3  wherein the sealant comprises a silicon based adhesive sealant for use in high temperatures. 
   
   
       5 . The device of  claim 3  wherein the sealant comprises a ceramic-metallic-epoxy sealant for use in high temperatures. 
   
   
       6 . A method of making an electroformed tooling device with integral heating and cooling fluid channels for use in injection molding and/or hot embossing, the method comprising:
 a first step of fabricating an electroform, a tool by electroforming from a structured substrate to create an embossing side of the electroform to function as an embossing and molding surface while leaving an uneven deposit on a non-embossing side of the electroform left as a by-product of electroforming;   a second step of machining a metal blank base comprising a smooth flat bottom surface, a top surface having a network of open channels in the top surface, and one or more surfaces having an opening therein communicating with the network of open channels to allow fluid to flow into a first opening and flow through the network of open channels and flow out a second opening;   a third step of using the electroform as an electrode to erode the top surface of the machined blank base using plunge electro-discharge machining to form a contoured surface to mate with the uneven contour of the non-embossing side of the electroform by lowering the uneven contour of the non-embossing side of the electroform onto the top surface of the blank base in the electro discharge machining environment;   a fourth step of interconnecting the electroformed tool and the blank base by a means of securing the electroformed tool to the blank base with the non-embossing side of the electroform contacting the mating top contoured surface of the blank base to form an electroformed tool with integral heating and cooling channels so that hot and cold fluid flowing through the blank base network of open channels contacts the electroform to alternately heat and cool the electroformed tool during use in injection molding and hot embossing processes.   
   
   
       7 . The method of  claim 6  wherein the electroform is adhered to the blank base using a structural adhesive and the structural adhesive is cured. 
   
   
       8 . The method of  claim 6  wherein the electroform is screwed to the blank base by a threaded fastener and the electroform is adhered to the blank base using a sealant for a watertight device. 
   
   
       9 . The method of  claim 8  wherein the electroform is adhered to the blank base using a silicon-based adhesive sealant for use in high temperatures. 
   
   
       10 . The method of  claim 8  wherein the electroform is adhered to the blank base using a ceramic-metallic-epoxy sealant for use in high temperatures. 
   
   
       11 . The method of  claim 6  further comprising the step of planarizing the bottom surface of the blank base to parallel the top embossing surface of the electroformed tool. 
   
   
       12 . The method of  claim 6  wherein the machining of the blank base comprises milling, drilling, grinding and turning techniques.