Process for producing micro-heat exchangers

• US 6,230,408 B1
• Filed: 09/03/1998
• Issued: 05/15/2001
• Est. Priority Date: 03/07/1996
• Status: Expired due to Fees

• Current Assignee: Institute für Mikrotechnik Mainz GmbH
• Original Assignee: Institute für Mikrotechnik Mainz GmbH
• Inventors: Weber, Lutz, Michel, Frank, Ehrfeld, Wolfgang, Richter, Thomas
• Primary Examiner(s): Rosenbaum, I Cuda
• Assistant Examiner(s): NGUYEN, TRINH T
• Application Number:
  US09/142,303
• Time in Patent Office: 985 Days
• Field of Search: 298/900.39, 295/275, 295/276, 264/219, 264/293, 219/69.17, 205/640
• US Class Current: 29/890.039
• CPC Class Codes: B23P 15/24 dies B21C3/18, B21C25/10, B21D37/20 take precedence
• CPC Class Codes: B23P 15/26 heat exchangers or the like making heat exchangers by methods covered by other subclasses B21D53/02
• CPC Class Codes: F28D 9/005 the plates having openings therein for both heat-exchange media
• CPC Class Codes: F28F 2255/18 sintered
• CPC Class Codes: F28F 2260/02 having microchannels
• CPC Class Codes: F28F 3/048 in the form of ribs integral with the element or local variations in thickness of the element, e.g. grooves, microchannels
• CPC Class Codes: Y10T 29/49366 Sheet joined to sheet

Abstract

A method for fabrication of micro heat exchangers, which enable an efficient heat transfer between two flowing media. In a first processing step, a plastic layer is structurized by means of photolithography, x-ray deep lithography, or laser ablation. This plastic structure is galvanically molded in a second processing step, preserving the structural properties. The resulting metallic microstructure, which is the inverse of the original structure, is used as a shaping insert to produce the individual layers from which the micro heat exchanger is assembled. The method according to the invention makes it possible to cheaply produce large numbers of micro heat exchangers.

Claims

1. A method for fabrication of heat exchangers, in which individual metal layers have structured surfaces and the structured metal layers are stacked and joined together to form a microstructure body with channel like passageways comprising the steps of:

a) incorporating a structured image in a surface of a body so as to form a structurized body, wherein said body has a surface structure inverse to said structure of said individual metal layers to be formed;

b) forming a metallic galvanic layer on the surface of the structurized body, said metallic galvanic layer having a surface structure which is inverse to said surface structure of said body,

c) electroeroding a metallic mold insert by utilizing said metallic galvanic layer as an electrode, said metallic mold insert after being electroeroded having a surface with a structure which is inverse to said surface of the metallic galvanic layer used as an electrode; and

d) forming said individual metal layers of said heat exchanger using said metallic mold insert.

2. A method according to claim 1, wherein said individual metal layers are formed by metal powder injection molding utilizing said metallic mold insert.

3. A method according to claim 1, wherein said individual metal layers are formed by embossing said individual metal layers with said metallic mold insert.

4. A method according to claim 1, wherein said individual metal layers are formed by pressing said metallic mold insert into an embossing material consisting of a metal powder embedded in a polymer matrix.

5. A method according to claim 1, wherein said individual metal layers comprise metal foil which are plastically deformed between two complementary metallic mold inserts.

6. A method according to claim 1, further comprising the step of assembling the individual layers to form a heat exchanger.

7. A method according to claim 1, wherein said body is plastic, and wherein a surface of said plastic body is metallized before said metallic galvanic layer is formed thereon.