Electronic component and manufacturing method for electronic component

• US 9,355,987 B2
• Filed: 09/10/2014
• Issued: 05/31/2016
• Est. Priority Date: 08/17/2012
• Status: Active Grant

• Current Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Original Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Inventors: Saito, Takashi, Kinoshita, Yoshito, Nishizawa, Tatsuo, Nashida, Norihiro
• Primary Examiner(s): Lee, Hsien Ming
• Application Number:
  US14/482,830
• Publication Number:
  US 20140374775A1
• Time in Patent Office: 629 Days
• Field of Search: 438/625, 438/652, 438/654, 438686-688, 257/750, 257/753, 257762-766
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/0346 Plating
• CPC Class Codes: H01L 2224/04026 Bonding areas specifically adapted for layer connectors
• CPC Class Codes: H01L 2224/05023 the whole internal layer protruding from the surface
• CPC Class Codes: H01L 2224/05073 Single internal layer
• CPC Class Codes: H01L 2224/05124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05147 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05564 Only on the bonding interface of the bonding area
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05639 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/05644 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/27332 using a powder
• 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 2224/29339 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/32014 the layer connector being smaller than the bonding area, e.g. bond pad
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32238 the layer connector connecting to a bonding area protruding from the surface of the item
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/33181 On opposite sides of the body
• CPC Class Codes: H01L 2224/33505 Layer connectors having different materials
• CPC Class Codes: H01L 2224/371 : with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/37147 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/40091 : Arched
• CPC Class Codes: H01L 2224/40225 : the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48227 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48229 : the bond pad protruding from the surface of the item
• CPC Class Codes: H01L 2224/73221 : Strap and wire connectors
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2224/83191 : wherein the layer connectors are disposed only on the semiconductor or solid-state body
• 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 2224/83203 : Thermocompression bonding, e.g. diffusion bonding, pressure joining, thermocompression welding or solid-state welding
• CPC Class Codes: H01L 2224/83205 : Ultrasonic bonding
• CPC Class Codes: H01L 2224/83439 : Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/83801 : Soldering or alloying
• CPC Class Codes: H01L 2224/8384 : Sintering
• CPC Class Codes: H01L 2224/8385 : using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 2224/84801 : Soldering or alloying
• CPC Class Codes: H01L 2224/8485 : using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 2224/85205 : Ultrasonic bonding
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• 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 24/33 : of a plurality of layer connectors
• CPC Class Codes: H01L 24/37 : of an individual strap connector
• CPC Class Codes: H01L 24/40 : of an individual strap connector
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00011 : Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/00015 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]

Abstract

A first metal film, of which major component is copper, is formed on a surface of a conductive portion which becomes a front surface electrode of a semiconductor element. A second metal film of which major component is silver is formed on a surface of the first metal film. A metal plate, which electrically connects the conductive portion and the other members (e.g. a circuit pattern of an insulated substrate) is bonded with a surface of the second metal film via a bonding layer containing silver particles. The second metal film does not contain nickel which decreases the bonding strength between the second metal film and the bonding layer containing silver particles. With the above configuration, an electronic component having a high bonding strength, excellent heat resistance and radiation performance, and a manufacturing method for the electronic component can be provided.

Claims

1. An electronic component, comprising:

a conductive portion which is disposed on a surface of a semiconductor element;

a first metal film, which is disposed on a surface of the conductive portion, and is formed of a material of which major component is copper;

a second metal film, which is disposed on a surface of the first metal film, and is formed of a material of which major component is a metal having a less ionization tendency than the first metal film;

a bonding layer, which is disposed on a surface of the second metal film, and contains silver particles; and

a metal plate of which one end is bonded with the bonding layer and an other end is bonded with a circuit pattern provided on a surface of an insulating substrate on which the semiconductor element is mounted.

2. The electronic component according to claim 1, wherein

the semiconductor element is formed of silicon or silicon carbide, and

the conductive portion is formed of a material of which major component is at least copper or aluminum.

3. The electronic component according to claim 1, wherein

the second metal film is formed of a material of which major component is silver.

4. The electronic component according to claim 1, wherein

the first metal film is a plating film or a deposition film.

5. The electronic component according to claim 1, wherein

the second metal film is a plating film or a deposition film.

6. The electronic component according to claim 1, wherein

the bonding layer is a sintered body formed by being heated at a temperature in the range of 200°

C. to 350°

C. and pressurized at a pressure in the range of 0.25 MPa to 30 MPa.

7. The electronic component according to claim 1, wherein

the second metal film does not contain nickel precipitates which decrease a bonding strength between the bonding layer and the second metal film.

8. A manufacturing method for an electronic component, comprising the steps of:

forming a first metal film formed of a material of which major component is copper, on a surface of a conductive portion disposed on a surface of a semiconductor wafer;

forming a second metal film formed of a material of which major component is a metal having a less ionization tendency than the first metal film, on a surface of the first metal film;

coating a conductive material containing silver particles on a surface of the second metal film;

placing, on the conductive material, one end of a metal plate of which an other end is bonded with a circuit pattern provided on a surface of a insulating substrate on which the semiconductor element is mounted; and

sintering the conductive material by heat treatment.

9. The manufacturing method for an electronic component according to claim 8, wherein

the conductive portion, formed of a material of which major component is at least copper or aluminum, is formed on the surface of the semiconductor wafer formed of silicon or silicon carbide.

10. The manufacturing method for an electronic component according to claim 8, wherein

the second metal film is formed of a material of which major component is silver.

11. The manufacturing method for an electronic component according to claim 8, wherein

the first metal film is formed by a plating method, a sputtering method or a deposition method.

12. The manufacturing method for an electronic component according to claim 8, wherein

the second metal film is formed by a plating method, a sputtering method or a deposition method.

13. The manufacturing method for an electronic component according to claim 8, wherein

the conductive material is sintered by being pressurized at a pressure in the ranges of 0.25 MPa to 30 MPa while being heated at a temperature in the range of 200°

C. to 350°

C. in the heat treatment.

14. The manufacturing method for an electronic component according to claim 8, wherein

nickel that decreases a bonding strength between a bonding layer, which is a sintered body of the conductive material, and the second metal film, does not particulate in the second metal film in the heat treatment.