# US 12,113,039 B2 · Low pressure sintering powder

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- Number: US 12,113,039 B2
- Document ID: US12113039B2
- Status: Granted
- Kind: B2
- Application number: 17/245,397
- Filed: 2021-04-30
- Published: 2021-08-12
- Granted: 2024-10-08
- Earliest claimed: 2014-04-11
- Assignees: Alpha Assembly Solutions Inc.
- Applicants: Alpha Assembly Solutions Inc.
- Inventors: Shamik Ghoshal; Nirmalya Kumar Chaki; Poulami Sengupta Roy; Siuli Sarkar; Anubhav Rustogi
- Web page: https://patentgrep.com/patent/US12113039B2

## CPC

- B23K 35/025: {Pastes, creams or slurries}
- B22F 1/052: characterised by a mixture of particles of different sizes or by the particle size distribution
- B22F 1/102: Metallic powder coated with organic material
- B22F 1/107: containing organic material comprising solvents, e.g. for slip casting
- B22F 1/17: Metallic particles coated with metal
- B22F 7/04: with one or more layers not made from powder, e.g. made from solid metal
- B22F 7/064: {using an intermediate powder layer}
- B23K 1/0016: {Soldering of electronic components}
- B23K 35/3006: {Ag as the principal constituent}
- B23K 35/3601: {with inorganic compounds as principal constituents}
- B23K 35/3613: {Polymers, e.g. resins}
- B23K 35/3618: {Carboxylic acids or salts}
- B23K 35/365: Selection of non-metallic compositions of coating materials either alone or conjoint with selection of soldering or welding materials
- H01B 1/22: the conductive material comprising metals or alloys
- B22F 2007/047: {non-pressurised baking of the paste or slurry containing metal powder}
- B22F 2301/255: Silver or gold
- B22F 2302/45: Others, including non-metals
- B23K 2101/40: Semiconductor devices
- B23K 2103/56: {being semiconducting}
- H05K 3/321: by conductive adhesives
- H10W 72/012: {of bump connectors, dummy bumps or thermal bumps}
- H10W 72/01204: {using temporary auxiliary members, e.g. using sacrificial coatings or handle substrates}
- H10W 72/01223: {in liquid form, e.g. by dispensing droplets or by screen printing}
- H10W 72/01225: {in solid form, e.g. by using a powder or by stud bumping}
- H10W 72/013: {of die-attach connectors}
- H10W 72/01304: {using temporary auxiliary members, e.g. using sacrificial coatings or handle substrates}
- H10W 72/01325: {in solid form}
- H10W 72/01336: {in solid form, e.g. by using a powder or by laminating a foil}
- H10W 72/01361: {Chemical or physical modification, e.g. by sintering or anodisation (patterning H10W72/01351)}
- H10W 72/01365: {Thermally treating (reflowing H10W72/01357)}
- H10W 72/016: {of strap connectors}
- H10W 72/0198: {batch processes}
- H10W 72/072: {of bump connectors}
- H10W 72/07232: {Compression bonding, e.g. thermocompression bonding}
- H10W 72/07234: {Using a reflow oven}
- H10W 72/073: {of die-attach connectors}
- H10W 72/07331: {Connecting techniques}
- H10W 72/07332: {Compression bonding, e.g. thermocompression bonding}
- H10W 72/07334: {Using a reflow oven}
- H10W 72/07341: {Controlling the bonding environment, e.g. atmosphere composition or temperature}
- H10W 72/075: {of bond wires}
- H10W 72/225: {Bumps having a filler embedded in a matrix}
- H10W 72/241: {Dispositions, e.g. layouts}
- H10W 72/252: {comprising solid metals or solid metalloids, e.g. PbSn, Ag or Cu}
- H10W 72/253: {not comprising solid metals or solid metalloids, e.g. polymers or ceramics}
- H10W 72/29: Bond pads specially adapted therefor
- H10W 72/325: {Die-attach connectors having a filler embedded in a matrix}
- H10W 72/351: {Materials of die-attach connectors}
- 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 72/59: Bond pads specially adapted therefor
- H10W 72/884: {Die-attach connectors and bond wires}
- H10W 72/923: {Bond pads having multiple stacked layers}
- H10W 72/952: {comprising metals or metalloids, e.g. PbSn, Ag or Cu}
- H10W 90/00: Package configurations
- H10W 90/724: {between a chip and a stacked insulating package substrate, interposer or RDL}
- H10W 90/732: {between stacked chips}
- 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}
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- 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})
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A sintering powder comprising: a first type of metal particles having a mean longest dimension of from 100 nm to 50 μm.

## Claims

### Claim 1

A sintering powder comprising:
a particulate, wherein the particulate comprises:
from 1 to 19 wt % of a first type of metal particles having a mean longest dimension of from 100 nm to 20 μm, wherein the first type of metal particles is at least partially coated with a first capping agent comprising oleic acid and has a D50 of from 1 to 3 μm;
from 81 to 99 wt % of a second type of metal particles having a mean longest dimension of from 5 to 75 nm, wherein the second type of metal particles is at least partially coated with a second capping agent comprising octylamine; and
a total capping agent concentration of up to 5 wt %.

### Claim 2 (depends on 1)

The sintering powder of claim 1, wherein the sintering powder has a total capping agent concentration of at least 0.1 wt %.

### Claim 3 (depends on 1)

The sintering powder of claim 1, wherein the sintering powder has a total capping agent concentration of from 0.1 to 3 wt % capping agent.

### Claim 4 (depends on 2)

The sintering powder of claim 2, wherein the concentration of the first type of metal particles in the particulate is from 1 to 10 wt % and the concentration of the second type of metal particles in the particulate is from 90 to 99 wt %.

### Claim 5 (depends on 2)

A sintering film comprising:
the sintering powder of claim 2; and
a binder.

### Claim 6 (depends on 2)

A sintering paste comprising:
the sintering powder of claim 2; and
a solvent.

### Claim 7 (depends on 6)

The sintering paste of claim 6, wherein the sintering paste further comprises at least one of a binder, a rheology modifier, an organosilver compound, an activator, a surfactant, a wetting agent, hydrogen peroxide, and organic peroxide.

### Claim 8 (depends on 6)

A method of manufacturing a sintered joint comprising:
printing the sintering paste of claim 6 onto a sheet;
heating the paste to at least partially remove the solvent and form a sintering film;
providing the sintering film in a vicinity of two or more work pieces to be joined; and
heating the sintering film to at least partially sinter the metal.

### Claim 9 (depends on 6)

A method of die attachment comprising:
printing the sintering paste of claim 6 onto a sheet;
heating the paste to at least partially remove the solvent and form a sintering film;
placing the sintering film between a die and a substrate to be joined; and
sintering the sintering film.

### Claim 10 (depends on 6)

A method of wafer bonding comprising:
printing the sintering paste of claim 6 onto a sheet;
heating the paste to at least partially remove the solvent and form a sintering film;
applying the sintering film to a substrate or the wafer to be bonded to form an assembly having a sintering film side and a substrate or the wafer side;
contacting the sintering film side of the assembly with a component or another wafer;
sintering the sintering film, wherein the sintering is carried out without the application of pressure or with an application of pressure in the range from 1-20 MPa and heating 150-400° C. for 1 to 60 minutes.

### Claim 11 (depends on 6)

A method of transferring a sintering film to a component, comprising:
printing the sintering paste of claim 6 onto a sheet;
heating the paste to at least partially remove the solvent and form a sintering film;
applying the sintering film to a substrate to form an assembly having a sintering film side and a substrate side;
contacting the sintering film side of the assembly with a component;
heating the assembly to a temperature of from 50 to 200° C.;
applying a pressure of from 1 to 5 MPa to the assembly for from 0.1 seconds to 60 minutes; and
separating the substrate from the sintering film.

### Claim 12

A sintering powder comprising:
a particulate, wherein the particulate comprises:
from 1 to 19 wt % of a first type of metal particles having a mean longest dimension of from 100 nm to 20 μm, wherein the first type of metal particles is at least partially coated with a first capping agent comprising oleic acid, has a tap density of from 3.5 to 5.5 g/cc, and has a D50 of from 1 to 3 μm; and
from 81 to 99 wt % of a second type of metal particles having a mean longest dimension of from 5 to 75 nm, wherein the second type of metal particles is at least partially coated with a second capping agent comprising octylamine.

### Claim 13 (depends on 12)

The sintering powder of claim 12, wherein the concentration of the first type of metal particles in the particulate is from 1 to 10 wt % and the concentration of the second type of metal particles in the particulate is from 90 to 99 wt %.

### Claim 14 (depends on 12)

A sintering film comprising:
the sintering powder of claim 12; and
a binder.

### Claim 15 (depends on 12)

A sintering paste comprising:
the sintering powder of claim 12; and
a solvent.

### Claim 16 (depends on 15)

The sintering paste of claim 15, wherein the sintering paste further comprises at least one of a binder, a rheology modifier, an organosilver compound, an activator, a surfactant, a wetting agent, hydrogen peroxide, and organic peroxide.

### Claim 17 (depends on 15)

A method of manufacturing a sintered joint comprising:
printing the sintering paste of claim 15 onto a sheet;
heating the paste to at least partially remove the solvent and form a sintering film;
providing the sintering film in a vicinity of two or more work pieces to be joined; and
heating the sintering film to at least partially sinter the metal.

### Claim 18 (depends on 15)

A method of die attachment comprising:
printing the sintering paste of claim 15 onto a sheet;
heating the paste to at least partially remove the solvent and form a sintering film;
placing the sintering film between a die and a substrate to be joined; and
sintering the sintering film.

### Claim 19 (depends on 15)

A method of wafer bonding comprising:
printing the sintering paste of claim 15 onto a sheet;
heating the paste to at least partially remove the solvent and form a sintering film;
applying the sintering film to a substrate or the wafer to be bonded to form an assembly having a sintering film side and a substrate or the wafer side;
contacting the sintering film side of the assembly with a component or another wafer;
sintering the sintering film, wherein the sintering is carried out without the application of pressure or with an application of pressure in the range from 1-20 MPa and heating 150-400° C. for 1 to 60 minutes.

### Claim 20 (depends on 15)

A method of transferring a sintering film to a component, comprising:
printing the sintering paste of claim 15 onto a sheet;
heating the paste to at least partially remove the solvent and form a sintering film;
applying the sintering film to a substrate to form an assembly having a sintering film side and a substrate side;
contacting the sintering film side of the assembly with a component;
heating the assembly to a temperature of from 50 to 200° C.;
applying a pressure of from 1 to 5 MPa to the assembly for from 0.1 seconds to 60 minutes; and
separating the substrate from the sintering film.

### Claim 21

A sintering powder comprising:
a particulate, wherein the particulate comprises:
from 1 to 19 wt % of a first type of metal particles having a mean longest dimension of from 100 nm to 20 μm, wherein the first type of metal particles is at least partially coated with a first capping agent comprising oleic acid and has a D50 of from 1 to 3 μm;
from 81 to 99 wt % of a second type of metal particles having a mean longest dimension of from 5 to 75 nm, wherein the second type of metal particles is at least partially coated with a second capping agent comprising octylamine; and
wherein the first type of metal particles and/or second type of metal particles comprises silver or an alloy or core-shell structures of silver coated particles thereof.

### Claim 22 (depends on 21)

The sintering powder of claim 21, wherein the concentration of the first type of metal particles in the particulate is from 1 to 10 wt % and the concentration of the second type of metal particles in the particulate is from 90 to 99 wt %.

### Claim 23 (depends on 21)

A sintering film comprising:
the sintering powder of claim 21; and
a binder.

### Claim 24 (depends on 21)

A sintering paste comprising:
the sintering powder of claim 21; and
a solvent.

### Claim 25 (depends on 24)

The sintering paste of claim 24, wherein the sintering paste further comprises at least one of a binder, a rheology modifier, an organosilver compound, an activator, a surfactant, a wetting agent, hydrogen peroxide, and organic peroxide.

### Claim 26 (depends on 24)

A method of manufacturing a sintered joint comprising:
printing the sintering paste of claim 24 onto a sheet;
heating the paste to at least partially remove the solvent and form a sintering film;
providing the sintering film in a vicinity of two or more work pieces to be joined; and
heating the sintering film to at least partially sinter the metal.

### Claim 27 (depends on 24)

A method of die attachment comprising:
printing the sintering paste of claim 24 onto a sheet;
heating the paste to at least partially remove the solvent and form a sintering film;
placing the sintering film between a die and a substrate to be joined; and
sintering the sintering film.

### Claim 28 (depends on 24)

A method of wafer bonding comprising:
printing the sintering paste of claim 24 onto a sheet;
heating the paste to at least partially remove the solvent and form a sintering film;
applying the sintering film to a substrate or the wafer to be bonded to form an assembly having a sintering film side and a substrate or the wafer side;
contacting the sintering film side of the assembly with a component or another wafer;
sintering the sintering film, wherein the sintering is carried out without the application of pressure or with an application of pressure in the range from 1-20 MPa and heating 150-400° ° C. for 1 to 60 minutes.

### Claim 29 (depends on 22)

A method of transferring a sintering film to a component, comprising:
printing the sintering paste of claim 22 onto a sheet;
heating the paste to at least partially remove the solvent and form a sintering film;
applying the sintering film to a substrate to form an assembly having a sintering film side and a substrate side;
contacting the sintering film side of the assembly with a component;
heating the assembly to a temperature of from 50 to 200° C.;
applying a pressure of from 1 to 5 MPa to the assembly for from 0.1 seconds to 60 minutes; and
separating the substrate from the sintering film.