Chemical microreactors and method for producing same

• US 6,409,072 B1
• Filed: 10/25/1999
• Issued: 06/25/2002
• Est. Priority Date: 02/20/1997
• Status: Expired due to Term

• Current Assignee: Atotech Deutschland GmbH (MKS Instruments Incorporated)
• Original Assignee: Atotech Deutschland GmbH (MKS Instruments Incorporated)
• Inventors: Breuer, Norbert, Meyer, Heinrich
• Primary Examiner(s): Drodge, Joseph W.
• Application Number:
  US09/380,055
• Time in Patent Office: 974 Days
• Field of Search: 422/68.1, 422/81, 422/99, 422/103, 422/104, 422/129, 422/130, 422/131, 422/138, 216/2, 216/56, 216/83, 216/96, 216/94, 216/95, 216/100, 156/60, 156/345, 228/101, 228/111.5, 228/164, 228/165, 228/199
• US Class Current: 228/111.5
• CPC Class Codes: B01J 19/0093 Microreactors, e.g. miniaturised or microfabricated reactors laboratory containers with capillary fluid transport in microfabricated channels or chambers B01L3/5027
• CPC Class Codes: B01J 2219/00783 Laminate assemblies, i.e. the reactor comprising a stack of plates
• CPC Class Codes: B01J 2219/00822 Metal
• CPC Class Codes: B01J 2219/00828 Silicon wafers or plates
• CPC Class Codes: B01J 2219/00831 Glass
• CPC Class Codes: B01J 2219/00835 Comprising catalytically active material
• CPC Class Codes: B01J 2219/00873 Heat exchange
• CPC Class Codes: B01J 2219/0097 Optical sensors
• CPC Class Codes: F28D 9/00 Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall F28F3/083, F28F3/086 take precedence
• 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: G03F 7/00 Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor using photoresist structures for special production processes, see the relevant places, e.g. B44C, H01L, e.g. H01L21/00, H05K
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor

Abstract

Chemical microreactors for chemical systhesis and their methods of manufacture are known, but have disadvantages such as extremely high manufacturing costs or poor flexibility for adaptation to various cases of application. These disadvantages are avoided by means of the microreactors and manufacturing methods according to the invention. The microreactors are characterized in that the reactors contain fluid ducts in at least one plane as well as feed and return lines for fluids, wherein the fluid ducts are defined by side walls of metal opposing each other and further side walls of metal or plastic extending between said side walls, and in which the planes are connected together and/or with a closure segment closing open fluid ducts by means of appropriate solder or adhesive layers. The manufacturing method is characterized by process sequences in which the individual reactor planes produced by means of electrolytic methods, are connected together by soldering or gluing.

Claims

1. Manufacturing process for chemical microreactors including at least one substrate with a metal coating on at least one side thereof, the process forming fluid ducts as well as feeding and drain ducts for fluids, without using plastic molding techniques comprising the following steps of:

a.) coating with a resist layer in a pattern forming fluid duct structures for forming fluid ducts on a metal surface located on each substrate by layering means selected from a group consisting of photoresist layering and screen-printed varnish layering, so that the metal surfaces are partly covered by the resist coating layer;

b.) removing metal from each uncoated metal surface of each substrate by a process selected from the group consisting of electroless and electrochemical etching;

c.) totally removing the resist coating layer;

d.) forming solder layers by depositing metals that can form eutectics;

e.) superimposing each substrate and a closure segment closing the fluid ducts, and interconnecting each substrate and the closure segment by soldering.

7. Method according to any one of claims 1 to 6 characterized in that in step a.) the metal surface on the substrate is coated with a photoresist layer, wherein the photoresist layer is exposed with an image being one of the group consisting of a positive image and a negative image of a pattern structure of the fluid ducts, and the photoresist layer is subsequently developed.

8. Method according to any one of the preceding claims 1 to 6 wherein the substrate metal surfaces consist of at least one metal selected from the group consisting of steel, stainless steel, copper, nickel and aluminum.

9. Method according to any one of the preceding claims 1 to 6, characterized in that passages are formed inside each substrate by performing steps a.) through c.).

10. Method according to any one of the preceding claims 1 to 6, characterized in that after superimposing and interconnecting each substrate surfaces of the fluid ducts are modified by a method, selected from the group consisting of metal deposition, metal etching and absorbing of chemical compounds.

11. Method according to claim 10, characterized in that the surfaces of the fluid ducts are modified by further deposition of at least one layer selected from the group of layers consisting of:

a.) a metallic layer selected from the group comprising palladium, platinum, rhodium, iridium, ruthenium and alloys of such metals; and

b.) a composite layer selected from the group consisting of a nickel/phosphorus alloy corrosion layer and a nickel/phosphorus alloy catalytic layer.

12. Method according to any one of the preceding claims 1 to 6, characterized in that actors are formed in the reactors by application of ferromagnetic metal layers wherein each actor is selected from the group consisting of valves and switches.

13. Method according to any one of the preceding claims 1 to 6, characterized in that sensors for measuring properties are formed in the reactors wherein each sensor is selected from the group consisting of sensors for measuring flowing fluids and sensors for measuring electrical line flow.

14. Method according to any one of the preceding claims 1 to 6, characterized also to include actors formed in the reactors selected from the group consisting of electrical resistive heating systems and cooling elements.

15. Method according to any one of the preceding claims 1 to 6, characterized in that for individual superimposed substrate layers of the microreactor, the metal is totally removed in defined areas of each substrate by etching-off in order to form translucent windows.

2. Manufacturing process for making chemical microreactors, which microreactors include at least one metal surfaced substrate with fluid ducts as well as feeding and drain conducts for fluids, without using plastic molding techniques, comprising the following steps of:

a.) forming a fluid duct pattern for forming fluid ducts on a metal surface located on the substrate by layering means selected from a group consisting of photoresist layering and screen-printed varnish layering, so that the substrate metal surfaces are partly covered by the layering;

b.) depositing of a further metal layer on the unlayered metal surfaces of the substrate by depositing means selected from the group of electroless and electrochemical deposition to form fluid duct structures thereon;

c.) totally removing the layering from the substrate metal surfaces;

d.) forming additional substrates according to steps a.) to c.);

e.) forming solder layers by depositing metals that can form eutectics on each substrate;

f.) superimposing the substrates and a closure segment closing the fluid ducts, and interconnecting the substrates and the closure segment by soldering.

3. Method according to claim 2 characterized in that in step b.) the deposited further metal layer is selected from the group consisting of tin, lead, nickel, cobalt, bismuth, silver, gold, and alloys of these metals.

4. Method according to claim 3, characterized in that the substrates are interconnected by the soldering connection of deposited further metal layers deposited on each metal sufaced substrate under the action of heat.

5. Method according to any one of claims 3 to 4, characterized in that in step b.) a tin layer is applied to a first side of each substrate and a bismuth layer is applied to a second side of each substrate, and in that plural substrates are placed upon one another such that tin and bismuth layers lie adjacent one another and are thereby subsequently soldered together during the soldering step f.).

6. Manufacturing method for chemical microreactors, including a least one metallic substrate, for providing a microreactor with fluid ducts as well as feeding and drain conducts for fluids, without using plastic molding techniques, comprising the following steps of:

a.) forming fluid duct structure patterns for forming fluid ducts on surfaces of the metallic substrate by resist layering means selected from the group of photoresist layering and screen-printed varnish layering, so that the substrate metallic surfaces are partly covered by the resist layer;

b.) depositing a metal layer on the non-resist layer covered surfaces of the metallic substrate;

c.) totally removing the resist layer;

d.) forming solder layers by depositing metal that can form eutectics;

e.) superimposing each substrate and a closure segment closing the fluid ducts and interconnecting each substrate and the closure segment by soldering.

16. A process for manufacturing a chemical microreactor, comprising the steps:

a. obtaining at least one substrate having a first and second opposite surfaces;

b. metal coating at least a first surface of each obtained substrate;

c. obtaining at least one closure segment;

d. selecting substrates and coating each selected substrate'"'"'s metal coated surface with a resist pattern defining fluid duct structures, and developing the coated resist pattern to provide a resist protective coating;

e. metal treating each selected substrate'"'"'s metal coated surface adjacent said resist layer protective coating on surface portions absent said resist protective coating;

f. removing, totally, each resist protective coating from each selected substrate;

g. superimposing each selected substrate and said closure segment; and

h. bonding each superimposed substrate and said closure segment with solder to from said microreactor.

17. The process of claim 16, wherein said solder bonding step includes:

a. after the step of removing the resist protective coating, a step of depositing solder on each selected substrate; and

b. wherein the step of bonding with solder includes melting said deposited solder to from said bonding.

18. The process of claim 17, wherein said metal treating step includes the step of removing metal from said substrate'"'"'s metal coated surface which is absent said resist protective coating.

19. The process of claim 18, wherein said depositing solder step includes depositing a metal on each of said superimposed substrate and closure segment adjacent surfaces which can form an eutectic solder with the metal deposited on an adjacent surface of said adjacent substrate and closure segment when melted.

20. The process of claim 17, wherein said metal treating step includes the step of depositing further metal on said substrate'"'"'s metal coated surface which is absent said resist protective coating.

21. The process of claim 20, wherein said depositing solder step includes depositing a metal on each of said superimposed substrate and closure segment adjacent surfaces which can form an eutectic solder with the metal deposited on the adjacent surface of said adjacent substrate and closure segment when melted.