BONDING MATERIAL AND BONDING METHOD USING SAME

• US 20170252874A1
• Filed: 08/31/2015
• Published: 09/07/2017
• Est. Priority Date: 09/01/2014
• Status: Active Grant

• Current Assignee: Dowa Electronics Materials Co. Ltd. (DOWA Holdings Company Limited)
• Original Assignee: Dowa Electronics Materials Co. Ltd. (DOWA Holdings Company Limited)
• Inventors: Endoh, Keiichi, Miyoshi, Hiromasa, Motomura, Kimikazu, Kurita, Satoru
• Granted Patent: US 10,821,558 B2
• Time in Patent Office: Days
• CPC Class Codes: B22F 1/05 Metallic powder characterised by the size or surface area of the particles
• CPC Class Codes: B22F 1/10 Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
• CPC Class Codes: B22F 7/008 characterised by the composition
• CPC Class Codes: B22F 7/062 involving the connection or repairing of preformed parts
• CPC Class Codes: B22F 9/02 using physical processes
• CPC Class Codes: B22F 9/24 starting from liquid metal compounds, e.g. solutions
• CPC Class Codes: B23K 1/0016 Brazing of electronic components
• CPC Class Codes: B23K 1/008 Soldering within a furnace B23K1/012 takes precedence
• CPC Class Codes: B23K 1/19 taking account of the properties of the materials to be soldered
• CPC Class Codes: B23K 20/026 with diffusion of soldering material
• CPC Class Codes: B23K 20/16 with interposition of special material to facilitate connection of the parts, e.g. material for absorbing or producing gas
• CPC Class Codes: B23K 20/233 without ferrous layer
• CPC Class Codes: B23K 2101/42 Printed circuits
• CPC Class Codes: B23K 2103/12 Copper or alloys thereof
• CPC Class Codes: B23K 35/025 Pastes, creams, slurries
• CPC Class Codes: B23K 35/302 Cu as the principal constituent
• CPC Class Codes: B23K 35/36 Selection of non-metallic compositions, e.g. coatings, fluxes B23K35/34 takes precedence; Selection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest selection of soldering or welding materials proper B23K35/24
• CPC Class Codes: B23K 5/00 Gas flame welding
• CPC Class Codes: C22C 9/00 Alloys based on copper
• CPC Class Codes: H01B 1/22 the conductive material comprising metals or alloys
• CPC Class Codes: H01L 2224/27848 : Thermal treatments, e.g. annealing, controlled cooling
• CPC Class Codes: H01L 2224/29294 : with a principal constituent of the material being a liquid not provided for in groups H01L2224/292 - H01L2224/29291
• CPC Class Codes: H01L 2224/29347 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/32245 : the item being metallic
• CPC Class Codes: H01L 2224/83075 : being inert
• CPC Class Codes: H01L 2224/83192 : wherein the layer connectors are disposed only on another item or body to be connected to the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/83204 : with a graded temperature profile
• CPC Class Codes: H01L 2224/8384 : Sintering
• CPC Class Codes: H01L 24/27 : Manufacturing methods
• CPC Class Codes: H01L 24/29 : of an individual layer connector
• CPC Class Codes: H01L 24/32 : of an individual layer connector
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group

Abstract

There is provided an inexpensive bonding material, which can be easily printed on articles to be bonded to each other and which can suppress the generation of voids in the bonded portions of the articles to be bonded to each other, and a bonding method using the same. In a bonding material of a copper paste which contains a copper powder containing 0.3% by weight or less of carbon and having an average particle diameter of 0.1 to 1 μm, and an alcohol solvent, such as a monoalcohol, a diol, a triol or a terpene alcohol, the content of the copper powder is in the range of from 80% by weight to 95% by weight, and the content of the alcohol solvent is in the range of from 5% by weight to 20% by weight.

Claims

1. A bonding material of a copper paste comprising:

a copper powder having an average particle diameter of 0.1 to 1 μ

m; and

an alcohol solvent,

wherein the content of the copper powder is in the range of from 80% by weight to 95% by weight, and the content of the alcohol solvent is in the range of from 5% by weight to 20% by weight.

2. A bonding material as set forth in claim 1, wherein the content of carbon in said copper powder is not larger than 0.3% by weight.

3. A bonding material as set forth in claim 1, wherein said alcohol solvent is a monoalcohol, a diol or a terpene alcohol.

4. A bonding material as set forth in claim 3, wherein said alcohol solvent contains a triol.

5. A bonding material as set forth in claim 1, which has a viscosity of not greater than 150 Pa·

s when the viscosity of said bonding material is measured at 25°

C. and 5 rpm by means of a rheometer.

6. A bonding material as set forth in claims 1, wherein the percentage of an area occupied by voids with respect to the area of a bonded surface of a copper bonding layer is not larger than 10% when said bonding material arranged between articles is heated to sinter copper therein to bond the articles to each other via the copper bonding layer.

7. A bonding material as set forth in claim 1, wherein the shear strength is not less than 6 MPa when said bonding material arranged between articles is heated to sinter copper therein to bond the articles to each other via the copper bonding layer.

8. A bonding method comprising the steps of:

arranging a bonding material, as set forth claim 1, between articles; and

heating the bonding material to sinter copper therein to form a copper bonding layer to bond said articles to each other with the copper bonding layer.

9. A bonding method as set forth in claim 8, wherein said heating is carried out while pressure is applied between said articles.