CN114951947A - Preparation and packaging method of graphene reinforced tin-based composite solder - Google Patents
Preparation and packaging method of graphene reinforced tin-based composite solder Download PDFInfo
- Publication number
- CN114951947A CN114951947A CN202210825923.5A CN202210825923A CN114951947A CN 114951947 A CN114951947 A CN 114951947A CN 202210825923 A CN202210825923 A CN 202210825923A CN 114951947 A CN114951947 A CN 114951947A
- Authority
- CN
- China
- Prior art keywords
- tin
- graphene
- copper
- based composite
- composite solder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- 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
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/02—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating by means of a press ; Diffusion bonding
- B23K20/023—Thermo-compression bonding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- 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
- B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
- B23K20/26—Auxiliary equipment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- 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
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/40—Making wire or rods for soldering or welding
Abstract
The invention relates to the field of electronic packaging, in particular to a preparation method and a packaging method of graphene reinforced tin-based composite solder. The method comprises the following steps: s1: mechanically grinding copper powder and solid carbon source powder to obtain mixed powder; s2: heating the mixed powder in a reaction chamber, and introducing reducing gas to obtain a graphene-copper composite material; s3: and mixing the graphene-copper composite material, the tin-based metal particles and the organic carrier to obtain the graphene reinforced tin-based composite solder. The method can uniformly introduce a large amount of graphene into the tin-based composite solder; the interface bonding strength of graphene and copper is improved in a chemical vapor reduction mode; the heat conduction performance of the composite solder is improved; the toughness of the composite solder is improved, and the mechanical reliability of the service of the welding spot is enhanced.
Description
Technical Field
The invention relates to the field of electronic packaging, in particular to a preparation method and a packaging method of graphene reinforced tin-based composite solder.
Background
Power electronic devices, which are key components of industrial equipment, need to be stably serviced at high voltage, high frequency and high temperature for a long time. In application scenes of power electronic devices represented by new energy automobiles and rail traction, requirements on voltage grade, service temperature and mechanical reliability are increasingly strict, and the traditional tin-based solder is limited by low melting point and limited heat conduction and electric conduction performance and cannot meet the packaging requirements of emerging power electronic devices. In recent years, researchers have proposed a tin-based bonding material based on the instant liquid phase diffusion soldering technique, in which metallic tin is melted during reflow and metallurgically reacts with a high melting point metal (such as copper, nickel, silver, etc.) in the solder to form an intermetallic compound having a high melting point. Compared with the traditional tin-based brazing, the method has the advantages that the welding spot has a higher melting point and better heat-conducting property. However, the intermetallic compound has the characteristics of hardness and brittleness, is difficult to resist the thermomechanical stress and deformation in the service process of the welding spot, and is easy to generate the defects of cracks, holes and the like, so that the reliability of the welding spot is greatly reduced.
The current technical scheme is to mechanically mix high-melting-point metal particles (such as copper, nickel, silver and the like), metallic tin particles and organic carriers (such as soldering flux, high-boiling-point solvent and the like) to obtain the tin-based composite solder. In the packaging process, the composite solder is printed on a substrate, then the substrate is pasted, and a reflow heating or hot-press welding process is carried out to obtain a high-melting-point welding structure taking the intermetallic compound as a main body.
The intermetallic compound can stimulate atoms to directionally diffuse due to the temperature rise in the service process of the welding spot to form a Kerkinjel cavity; part of intermetallic compounds such as Cu6Sn5 have phase change behavior, and the volume is shrunk due to phase change to generate holes; the intermetallic compound is a hard and brittle phase and is easy to crack under the action of thermo-mechanical stress when the welding spot is in service, so that the welding spot fails; although the thermal conductivity of the intermetallic compound is higher than that of the traditional tin-based solder, the thermal conductivity is lower than that of materials such as sintered silver and sintered copper (more than 200W/mK), and is only 50-70W/mK.
Disclosure of Invention
In view of the problems in the prior art, the invention realizes the compounding of the graphene with high volume fraction and the copper by a chemical vapor deposition mode, and reduces the contact resistance and the contact thermal resistance of the graphene and the copper; the graphene is introduced into the tin-based composite solder, so that the toughness and the breaking strength of a welding spot are enhanced, and the service reliability of the welding spot is improved; the heat-conducting property of the welding spot is enhanced.
The invention aims to provide a preparation and packaging method of a graphene reinforced tin-based composite solder, aiming at improving the toughness, the heat-conducting property and the mechanical reliability of the tin-based composite solder after a welding spot is formed.
The invention is realized by the following technical scheme:
the invention firstly provides a preparation method of a graphene reinforced tin-based composite solder, which comprises the following steps:
s1: mechanically grinding copper powder and solid carbon source powder to obtain mixed powder;
s2: placing the mixed powder in a reaction chamber for heating, and introducing reducing gas to obtain a graphene-copper composite material;
s3: and mixing the graphene-copper composite material, the tin-based metal particles and the organic carrier to obtain the graphene reinforced tin-based composite solder.
According to the invention, researches show that graphene is directly added into the composite solder in a mechanical mixing mode, but the method has several problems: 1. the addition amount is limited; 2. the graphene and the solder have poor bonding force, and the effects of enhancing heat conduction and toughness are not ideal.
In a preferred embodiment of the present invention, the size of the copper powder in step S1 is 0.5 to 10 μm. The solid carbon source powder can be one of polymethyl methacrylate, polystyrene, polytetrafluoroethylene, polyimide, etc., and has a size of 0.1-1 μm.
In a preferred embodiment of the present invention, the ratio of the copper powder and the solid carbon source powder in step S1 is 100:1-10: 1.
In a preferred embodiment of the present invention, the mechanical milling in step S1 may be one of ball milling, roller milling and rod milling, and is preferably ball milling.
In a preferred embodiment of the present invention, the mixed powder in step S1 has a diameter of 1-20 μm and a thickness of 0.1-1 μm.
For the tin-based composite solder, copper powder with smaller size (1-20 mu m after ball milling) is used to accelerate the welding reaction process, shorten the reaction time and improve the welding efficiency. For solid carbon source powder, if the powder thickness is too large (greater than 1 μm), the organic matter coated on the surface of the mixed powder is too thick, and is difficult to be completely reduced into graphene in reducing gas, and if the powder thickness is too small (less than 0.1 μm), the organic matter coated on the surface of the mixed powder is too thin, and the uniform coating of copper by graphene cannot be ensured.
As a preferred technical scheme of the invention, the heating temperature in the step S2 is 600-900 ℃, the reducing gas is one of hydrogen, a mixed gas of hydrogen and argon, and a mixed gas of hydrogen and nitrogen, and the volume fraction of hydrogen in the mixed gas is not less than 90%. The amount of the mixed powder is 1-10kg, the heating time is 1-5h, and the flow rate of the reducing gas in the reaction process is 1-10L/min.
As a preferable technical solution of the present invention, in the step S3, the mass fraction of the graphene-copper composite material is 40 to 70 wt%, the mass fraction of the tin-based metal particles is 20 to 50 wt%, the mass fraction of the organic vehicle is 10 to 15 wt%, and the sum of the proportions of the respective substances is 100%.
In a preferred embodiment of the present invention, in step S3, the tin-based metal particles are one of tin, tin-silver-copper 305 alloy, tin-silver alloy, tin-copper alloy, tin-bismuth alloy, and tin-indium alloy, the size of the tin-based metal particles is 2 to 30 μm, and the organic vehicle is a mixture of hydrogenated rosin resin, glutaric acid, adipic acid, ethylene glycol, propylene glycol, polyethylene glycol, terpineol, and the like.
The invention further provides a packaging method of the graphene reinforced tin-based composite solder, which comprises the following steps:
s1: printing the graphene reinforced tin-based composite solder prepared by the method on a substrate;
s2: baking the substrate coated with the solder, and then pasting to form a packaging structure;
s3: and carrying out hot-press welding on the packaging structure to obtain a welding spot.
In a preferred embodiment of the present invention, in step S1, the solder paste printing thickness is 20-200 μm, and the surface of the substrate is one of copper, gold, silver, nickel, palladium, and platinum.
As a preferable technical scheme of the invention, in the step S2, the baking temperature is 80-120 ℃, the baking time is 10-30min, and an air-blast drying oven or a hot plate is used for baking.
As a preferred technical scheme of the invention, the hot-press welding in the step S3 is carried out by using a hot-press welding device, the temperature is 150-.
The beneficial effects of the invention compared with the prior art comprise:
(1) the method can uniformly introduce a large amount of graphene into the tin-based composite solder;
(2) according to the invention, the interface bonding strength of graphene and copper is improved in a chemical vapor reduction mode;
(3) the invention improves the heat-conducting property of the composite solder;
(4) the invention improves the toughness of the composite solder and enhances the mechanical reliability of the service of the welding spot.
Detailed Description
The present invention will be further illustrated with reference to the following examples, but the present invention is not limited thereto.
Example 1:
mechanically ball-milling 10 mu m copper powder and solid carbon source powder (the ball-milling rotation speed is 200RPM, the ball-milling time is 8 hours), wherein the solid carbon source powder is 0.5 mu m polymethyl methacrylate, and the mass ratio of the copper powder to the solid carbon source powder is 50:1, so as to obtain mixed powder, wherein the diameter of the mixed powder is 20 mu m, and the thickness of the mixed powder is 0.8 mu m;
placing the mixed powder (2kg) powder in a reaction chamber, heating at 800 ℃, introducing hydrogen for 3h, and obtaining the graphene-copper composite material, wherein the flow rate of reducing gas in the reaction process is 5L/min;
mixing the graphene-copper composite material, the tin-based metal particles and the organic carrier, wherein the mass fraction of the graphene-copper composite material is 50 wt%, so as to obtain graphene reinforced tin-based composite solder; the tin-based metal particles are tin-silver-copper 305 alloy, the size is 5-15 mu m, and the mass fraction is 35 wt%; the mass fraction of the organic carrier is 15 wt%, the organic carrier is a mixture of hydrogenated rosin resin, adipic acid and ethylene glycol, and the mass ratio is 5:1: 5.
Printing the graphene reinforced tin-based composite solder on a copper substrate, wherein the printing thickness of the solder paste is 100 mu m; baking the substrate coated with the solder at 100 ℃, and then pasting to form a packaging structure; and carrying out hot-press welding on the packaging structure at the temperature of 230 ℃ and the pressure of 2MPa for 3min to obtain the welding spot.
The welding spot is tested, the shear strength is 90MPa, and the thermal conductivity is 150W/mK. And (3) performing cold and hot impact test on the welding spot, wherein the low temperature is-40 ℃, the high temperature is 125 ℃, the high and low temperature retention time is 15min, the conversion time is less than 3min, and the welding spot still maintains the shear strength of 70MPa after 1000 cycles.
Example 2:
carrying out mechanical ball milling on 0.5 mu m copper powder and solid carbon source powder (the ball milling rotation speed is 200RPM, the ball milling time is 8 hours), wherein the solid carbon source powder is 0.1 mu m polymethyl methacrylate, the mass ratio of the copper powder to the solid carbon source powder is 10:1, and mixed powder is obtained, the diameter of the mixed powder is 2 mu m, and the thickness of the mixed powder is 0.2 mu m;
placing the mixed powder (1kg) in a reaction chamber, heating at 800 ℃, introducing hydrogen for 1h, and obtaining the graphene-copper composite material, wherein the flow rate of reducing gas in the reaction process is 2L/min;
mixing the graphene-copper composite material, the tin-based metal particles and the organic carrier, wherein the mass fraction of the graphene-copper composite material is 45 wt%, so as to obtain graphene reinforced tin-based composite solder; the tin-based metal particles are tin-silver-copper 305 alloy, the size is 5-15 mu m, and the mass fraction is 40 wt%; the mass fraction of the organic carrier is 15 wt%, the organic carrier is a mixture of hydrogenated rosin resin, adipic acid and ethylene glycol, and the mass ratio is 5:1: 5.
Printing the graphene reinforced tin-based composite solder on a copper substrate, wherein the printing thickness of the solder paste is 100 mu m; baking the substrate coated with the solder at 100 ℃, and then pasting to form a packaging structure; and carrying out hot-press welding on the packaging structure at the temperature of 230 ℃ and the pressure of 2MPa for 3min to obtain the welding spot.
The welding point is tested, the shearing strength is 103MPa, and the thermal conductivity is 135W/mK. And (3) performing cold and hot impact test on the welding spot, wherein the low temperature is-40 ℃, the high temperature is 125 ℃, the high and low temperature retention time is 15min, the conversion time is less than 3min, and after 1000 cycles, the welding spot still retains the shear strength of 86 MPa.
Comparative example 1:
carrying out mechanical ball milling on 10-micron copper powder to obtain powder, wherein the diameter of the powder is 18 microns, and the thickness of the powder is 0.9 micron; mixing copper powder, tin-based metal particles and an organic carrier, wherein the mass fraction of copper is 50 wt%; the tin-based metal particles are tin-silver-copper 305 alloy, the size is 5-15 mu m, and the mass fraction is 35 wt%; the mass fraction of the organic carrier is 15 wt%, and the organic carrier is a mixture of hydrogenated rosin resin, adipic acid and ethylene glycol in a ratio of 5:1: 5. Printing the composite solder on a copper substrate, wherein the printing thickness of the solder paste is 100 mu m; baking the substrate coated with the solder at 100 ℃, and then pasting to form a packaging structure; and carrying out hot-press welding on the packaging structure at the temperature of 230 ℃ and the pressure of 2MPa for 3min to obtain a welding spot.
The welding spot is tested, the shear strength is 40MPa, and the thermal conductivity is 35W/mK. And (3) performing a cold and hot impact test on the welding spot, wherein the low temperature is-40 ℃, the high temperature is 125 ℃, the high and low temperature retention time is 15min, the conversion time is less than 3min, and after 1000 cycles, the strength of the welding spot is reduced to 20 MPa.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.
Claims (10)
1. A preparation method of graphene reinforced tin-based composite solder is characterized by comprising the following steps:
s1: mechanically grinding the copper powder and the solid carbon source powder to obtain mixed powder;
s2: heating the mixed powder in a reaction chamber, and introducing reducing gas to obtain a graphene-copper composite material;
s3: and mixing the graphene-copper composite material, the tin-based metal particles and the organic carrier to obtain the graphene reinforced tin-based composite solder.
2. The preparation method of the graphene-reinforced tin-based composite solder according to claim 1, characterized by comprising the following steps: the size of the copper powder in the step S1 is 0.5-10 μm; the solid carbon source powder can be one of polymethyl methacrylate, polystyrene, polytetrafluoroethylene, polyimide, etc., and has a size of 0.1-1 μm.
3. The preparation method of the graphene-reinforced tin-based composite solder according to claim 1, characterized by comprising the following steps: and the mass ratio of the copper powder to the solid carbon source powder in the step S1 is 100:1-10: 1.
4. The preparation method of the graphene-reinforced tin-based composite solder according to claim 1, characterized by comprising the following steps: the mechanical milling in the step S1 may be one of ball milling, roller milling and rod milling, and is preferably ball milling.
5. The preparation method of the graphene-reinforced tin-based composite solder according to claim 1, characterized by comprising the following steps: the mixed powder in the step S1 has a diameter of 1-20 μm and a thickness of 0.1-1 μm.
6. The preparation method of the graphene-reinforced tin-based composite solder according to claim 1, characterized by comprising the following steps: in the step S2, the heating temperature is 600-900 ℃, the reducing gas is one of hydrogen, a mixed gas of hydrogen and argon, and a mixed gas of hydrogen and nitrogen, the volume fraction of hydrogen in the mixed gas is not less than 90%, the use amount of the mixed powder is 1-10kg, the heating time is 1-5h, and the flow rate of the reducing gas in the reaction process is 1-10L/min.
7. The preparation method of the graphene-reinforced tin-based composite solder according to claim 1, characterized by comprising the following steps: in the step S3, the mass fraction of the graphene-copper composite material is 40-70 wt%, the mass fraction of the tin-based metal particles is 20-50 wt%, the mass fraction of the organic carrier is 10-15 wt%, and the sum of the proportions of the substances is 100%.
8. The preparation method of the graphene-reinforced tin-based composite solder according to claim 1, characterized by comprising the following steps: in the step S3, the tin-based metal particles are one of tin, tin-silver-copper 305 alloy, tin-silver alloy, tin-copper alloy, tin-bismuth alloy and tin-indium alloy, the size of the tin-based metal particles is 2-30 μm, and the organic carrier is a mixture of hydrogenated rosin resin, glutaric acid, adipic acid, ethylene glycol, propylene glycol, polyethylene glycol, terpineol and the like.
9. A packaging method of graphene reinforced tin-based composite solder is characterized by comprising the following steps:
s1: printing the graphene reinforced tin-based composite solder prepared by the method of any one of the preceding claims 1 to 8 on a substrate;
s2: baking the substrate coated with the solder, and then pasting to form a packaging structure;
s3: and carrying out hot-press welding on the packaging structure to obtain a welding spot.
10. The packaging method of graphene reinforced tin-based composite solder according to claim 9,
in the step S1, the printing thickness of the soldering paste is 20-200 μm, and the surface of the substrate is one of copper, gold, silver, nickel, palladium and platinum;
in the step S2, baking is carried out at the temperature of 80-120 ℃ for 10-30min by using a blast drying oven or a hot plate;
the hot-press welding in the step S3 is carried out by using a hot-press welding device, the temperature is 150-280 ℃, the pressure is 1-10MPa, and the time is 2-10 min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210825923.5A CN114951947A (en) | 2022-07-14 | 2022-07-14 | Preparation and packaging method of graphene reinforced tin-based composite solder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210825923.5A CN114951947A (en) | 2022-07-14 | 2022-07-14 | Preparation and packaging method of graphene reinforced tin-based composite solder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114951947A true CN114951947A (en) | 2022-08-30 |
Family
ID=82968994
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210825923.5A Pending CN114951947A (en) | 2022-07-14 | 2022-07-14 | Preparation and packaging method of graphene reinforced tin-based composite solder |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114951947A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116810210A (en) * | 2023-05-26 | 2023-09-29 | 齐齐哈尔大学 | Composite brazing filler metal and preparation method and application thereof |
-
2022
- 2022-07-14 CN CN202210825923.5A patent/CN114951947A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116810210A (en) * | 2023-05-26 | 2023-09-29 | 齐齐哈尔大学 | Composite brazing filler metal and preparation method and application thereof |
| CN116810210B (en) * | 2023-05-26 | 2024-04-09 | 齐齐哈尔大学 | Method for preparing composite solder |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11699632B2 (en) | Methods for attachment and devices produced using the methods | |
| Suganuma et al. | Low-temperature low-pressure die attach with hybrid silver particle paste | |
| JP4342176B2 (en) | Functional alloy particles | |
| CN104759725B (en) | A kind of method using micro/nano level metallic particles filling Sn parent metal to realize electronic building brick High-temperature Packaging | |
| CN109797392B (en) | Aluminum alloy surface modified sintered lead-free low-temperature silver paste thickness membrane method | |
| Jung et al. | Pressureless die attach by transient liquid phase sintering of Cu nanoparticles and Sn-58Bi particles assisted by polyvinylpyrrolidone dispersant | |
| Nguyen et al. | Enhancement of bonding strength in BiTe-based thermoelectric modules by electroless nickel, electroless palladium, and immersion gold surface modification | |
| CN114951947A (en) | Preparation and packaging method of graphene reinforced tin-based composite solder | |
| Liu et al. | Microstructural evolution, fracture behavior and bonding mechanisms study of copper sintering on bare DBC substrate for SiC power electronics packaging | |
| CN114643435A (en) | Low-temperature sintered nano-copper soldering paste, and preparation method and application method thereof | |
| Wu et al. | Rapid and low temperature sintering bonding using Cu nanoparticle film for power electronic packaging | |
| CN114391169A (en) | Silver sintered preparation and use thereof for connecting electronic components | |
| CN112961633A (en) | Low-temperature cured conductive adhesive and preparation method thereof | |
| Zhang et al. | Low temperature die attach based on sub-micron ag particles and the high temperature reliability of sintered joints | |
| CN108161270B (en) | Particle-reinforced Sn-Zn nano solder for low-temperature packaging of aluminum alloy and LED chip and preparation method thereof | |
| CN112809241B (en) | Aluminum soldering paste and preparation method thereof | |
| Zhang et al. | Exploration of Key Factors for the Sintering of Micro-Nano Silver Paste | |
| Jang et al. | Effects of Ag Flake Addition in Sn-3.0 Ag-0.5 Cu on Microstructure and Mechanical Properties with High-Temperature Storage Test | |
| Wernicki et al. | Preparation and characterization of nano-solder paste with high nanoparticle loading and their thermal and printing properties | |
| Suganuma | WBG power semiconductor packaging with advanced interconnection technologies | |
| Li et al. | Nano-Ag filled anisotropic conductive adhesives (ACA) with self-assembled monolayer and sintering behavior for high | |
| CN116890181A (en) | Tin-based composite solder based on Cu@Sn@Ag core-shell structure, and preparation method and packaging method thereof | |
| CN115894064B (en) | AMB slurry for low-silver ceramic-containing metallization and preparation method thereof | |
| CN114833494B (en) | Process reactive solder for realizing low-temperature welding high-temperature service and joint preparation method | |
| Zeng et al. | Review of Copper-Silver Core-Shell Sintering Pastes: Technology and Future Trends |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |