# US 2022/0045026 A1 · Conductive paste

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- Number: US 2022/0045026 A1
- Document ID: US20220045026A1
- Status: Published application
- Kind: A1
- Application number: 17/280,256
- Filed: 2019-09-24
- Published: 2022-02-10
- Earliest claimed: 2018-09-28
- Assignees: Namics Corporation
- Applicants: Namics Corporation
- Inventors: Masashi KAJITA; Masahiro KITAMURA; Takayuki HIGUCHI; Noritsuka MIZUMURA
- Web page: https://patentgrep.com/patent/US20220045026A1

## CPC

- H10W 42/121: {protecting against mechanical damage (H10W76/00, H10W74/00 take precedence)}
- B22F 1/052: characterised by a mixture of particles of different sizes or by the particle size distribution
- B22F 1/054: Nanosized particles
- B22F 1/056: {Submicron particles having a size above 100 nm up to 300 nm}
- B22F 1/107: containing organic material comprising solvents, e.g. for slip casting
- H01B 1/22: the conductive material comprising metals or alloys
- B22F 9/24: starting from liquid metal compounds, e.g. solutions
- B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy
- H10W 72/073: {of die-attach connectors}
- H10W 72/07331: {Connecting techniques}
- H10W 72/07341: {Controlling the bonding environment, e.g. atmosphere composition or temperature}
- H10W 72/075: {of bond wires}
- H10W 72/325: {Die-attach connectors having a filler embedded in a matrix}
- H10W 72/352: {comprising metals or metalloids, e.g. solders}
- H10W 72/353: {not comprising solid metals or solid metalloids, e.g. ceramics}
- H10W 72/354: {comprising polymers}
- H10W 72/884: {Die-attach connectors and bond wires}
- H10W 72/952: {comprising metals or metalloids, e.g. PbSn, Ag or Cu}
- H10W 74/00: Encapsulations, e.g. protective coatings
- H10W 90/734: {between a chip and a stacked insulating package substrate, interposer or RDL}
- H10W 90/736: {between a chip and a stacked lead frame, conducting package substrate or heat sink}
- H10W 90/754: {between a chip and a stacked insulating package substrate, interposer or RDL}
- H10W 90/756: {between a chip and a stacked lead frame, conducting package substrate or heat sink}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K})

## Abstract

The present invention addresses the problem of providing a conductive paste that achieves both low resistance and high adhesion strength (die shear strength) of the resulting conductive body after firing. The present invention provides a conductive paste comprising: (A) copper fine particles having an average particle diameter of 50 nm to 400 nm and a crystallite diameter of 20 nm to 50 nm; (B) copper particles having an average particle diameter of 0.8 μm to 5 μm and a ratio of a crystallite diameter to the crystallite diameter of the copper particles (A) of 1.0 to 2.0; and (C) a solvent.

## Claims

### Claim 1

A conductive paste comprising:
(A) copper fine particles having an average particle diameter of 50 nm to 400 nm and a crystallite diameter of 20 nm to 50 nm;
(B) copper particles having an average particle diameter of 0.8 μm to 5 μm and a ratio of a crystallite diameter to the crystallite diameter of the (A) copper fine particles of 1.0 to 2.0; and
(C) a solvent.

### Claim 2 (depends on 1)

The conductive paste according to claim 1, wherein the (B) copper particles have an aspect ratio of 1.0 to 2.0.

### Claim 3 (depends on 1)

The conductive paste according to claim 1, further comprising (D) an amine compound.

### Claim 4 (depends on 1)

The conductive paste according to claim 1, wherein a content of the (B) copper particles is 20 parts by mass to 80 parts by mass based on a total 100 parts by mass of the (A) copper fine particles and the (B) copper particles.

### Claim 5 (depends on 1)

A die attach agent comprising the conductive paste according to claim 1.

### Claim 6 (depends on 5)

A semiconductor device fabricated using the die attach agent according to claim 5.

### Claim 7 (depends on 6)

The semiconductor device according to claim 6, wherein a surface to which the die attach agent is applied is copper.