PROCESS AND PASTE FOR CONTACTING METAL SURFACES
For production of an electrically conductive or thermally conductive connection for contacting two elements, an elemental metal, in particular silver, is formed from a metal compound, in particular a silver compound, between the contact surfaces. In this production, the processing temperature for the use of a silver solder can be decreased below 240° C. and the processing pressure can be reduced to normal pressure. A contacting paste for this purpose contains a metal compound, in particular a silver compound, which decomposes below 400° C. while forming elemental silver. As a result, a metal is generated in situ from a chemical compound for producing a contact, which is usable above the temperature necessary for its production.
1 . A process for producing an electrically conductive or thermally conductive connection for contacting two elements, comprising forming elemental silver in situ from a silver compound between contact surfaces of the two elements standing one over another.
2 . The process according to claim 1 , wherein the silver compound is selected from an organic silver compound or silver carbonate.
3 . The process according to claim 1 , wherein at least one of the contact surfaces has a non-precious metal in its surface.
4 . The process according to claim 1 , wherein the contacting process is carried out at a temperature below 400° C.
5 . The process according claim 1 , wherein the silver compound is present in a paste, which is deposited on one of the contact surfaces.
6 . The process according to claim 1 , wherein the contacting of the two elements comprises fastening:
a) of cooling bodies or LEDs or DCBs or solar cells; or
b) Si semiconductors on a Cu substrate; or
c) for a flip chip or Package on Package (PoP).
7 . A process for producing a full-surface metal contact between a metallic connection surface of an electronic component and a metallic connection surface of another component for fixing the components to each other at a temperature below 400° C., the process comprising applying to a contact surface of one of the components a material comprising a compound of metal or a component thereof, wherein the material decomposes below 400° C. into the metal or a component thereof, and wherein the metal or component thereof is one that melts just above 400° C., such that the metal contact is produced in situ by decomposition of the material below 400° C.
8 . The process according to claim 7 , wherein the process comprises forming elemental silver in situ from a silver compound between contact surfaces of one of the electrical components and the other component standing over one another.
9 . The process according to claim 7 , wherein at least one of the contact surfaces has a non-precious metal in its surface.
10 . The process according to claim 7 , wherein the contacting process is carried out at a temperature below 400° C.
11 . The process according to claim 7 , wherein the silver compound is present in a paste, which is deposited on one of the contact surfaces.
12 . The process according to claim 7 , wherein the contacting of the two components comprises fastening:
(a) of cooling bodies or LEDs or DCBs or solar cells; or
(b) Si semiconductors on a Cu substrate; or
(c) for a flip chip or Package on Package (PoP).
13 . The process according to claim 7 , wherein the material comprises a paste
containing a solid in an organic mass, wherein the organic mass is a gel and the solid comprises a silver compound which decomposes below 400° C. with formation of elemental silver, and wherein the contacting paste contains silver or copper particles.
14 . The process according to claim 7 , wherein the contacted surfaces form an electrically conducting or thermally conducting connection, and wherein the process takes place at pressures up to 5 bar or at a processing temperature below 240° C. or at pressures up to 5 bar and a processing temperature below 240° C.
15 . A process for connecting surfaces of electronic components using a contacting paste containing a solid in an organic mass, wherein the organic mass is a gel and the solid comprises a silver compound which decomposes below 400° C. with formation of elemental silver, and wherein at least one of the surfaces to be connected is made of a non-precious metal.
16 . The process according to claim 15 , wherein the contacted surfaces form an electrically conducting or thermally conducting connection, and wherein the process takes place at pressures up to 5 bar or at a processing temperature below 240° C. or at pressures up to 5 bar and a processing temperature below 240° C.
17 . The process according to claim 15 , wherein the process comprises low-pressure contacting in a field of power electronics or opto-electronics or for fastening LEDs or cooling bodies.
18 . The process according to claim 15 , wherein the paste comprises a mixture of copper powder and a metal compound decomposable below 400° C.
19 . The process according to claim 15 , wherein the surfaces comprise metallic surfaces of two respective objects, and wherein the process comprises forming a metal contact by generating metal from a chemical compound below a maximum use temperature of the contact generated.
20 . The process according to claim 15 , wherein the electronic components loose electrical components, and wherein the method provides for full-surface fastening of the loose components.