CN-114709324-B - High-reliability thermoelectric refrigeration sheet and packaging method thereof

CN114709324BCN 114709324 BCN114709324 BCN 114709324BCN-114709324-B

Abstract

The invention provides a high-reliability thermoelectric cooling sheet which comprises a PN type thermocouple pair, a packaging connecting layer, a copper-clad substrate and a copper-clad substrate, wherein a nickel layer is compounded on the surface of the PN type thermocouple pair, the packaging connecting layer is compounded on the PN type thermocouple pair, and the packaging connecting layer is made of porous graphene-metal composite materials. The invention connects the crystal grain and the copper-clad ceramic substrate through the packaging connecting layer to form a conductive path. According to the invention, a porous graphene-metal composite structure is utilized to replace the traditional alloy solder, on one hand, low-temperature metallurgical connection is realized between nanoneedle cones due to a nano effect, on the other hand, the porous graphene can effectively enhance the strength of a connecting layer, and simultaneously can be used as a flexible layer to absorb thermal stress, and meanwhile, the regulation and control of the thermal expansion coefficient of an interface layer can be realized by changing the geometric structure of the porous graphene, so that effective thermal matching is realized, the thermal stress in a service environment is reduced, the reliability of a device is improved, and the service life is prolonged.

Inventors

SONG XIAOHUI
ZHANG WEI
HAN YUHUI
WANG QIFU
WU SHUNLI
WANG JIANYE
LIANG NAN

Assignees

河南省科学院应用物理研究所有限公司
河南省科学院

Dates

Publication Date: 20260505
Application Date: 20220215

Claims (10)

1. A thermoelectric refrigeration piece is characterized by comprising a PN type thermocouple pair with a nickel layer compounded on the surface; the packaging connecting layer is compounded on the PN type thermocouple pair; A copper-clad substrate compounded on the packaging connection layer; the material of the packaging connecting layer comprises a porous graphene-metal composite material; The porous graphene-metal composite material comprises porous graphene and a metal needle cone; a nano metal needle cone connecting surface A is arranged on the nickel layer on the surface of the thermocouple pair; a nano metal needle cone connecting surface B is arranged on the copper layer on the surface of the copper-clad substrate; And the nano metal needle cone connecting surface A, the nano metal needle cone connecting surface B and the porous graphene are packaged by hot pressing to form the packaging connecting layer.
2. The thermoelectric cooling fin according to claim 1, wherein the number of the PN thermocouple pairs includes one or more groups; the PN type thermocouple pair comprises a P type bismuth antimonide cuboid grain thermocouple pair and an N type bismuth antimonide cuboid grain thermocouple pair; The thickness of the nickel layer is 1-3 mu m.
3. The thermoelectric cooling fin according to claim 1, wherein the copper-clad layer on the surface of the copper-clad substrate is a patterned copper structure layer; the copper-clad substrate comprises a copper-clad ceramic substrate; in the porous graphene-metal composite, the metal includes copper and/or nickel.
4. The thermoelectric cooling fin according to claim 1, wherein the pore diameter of the porous graphene is 100-300 nm; the porous graphene includes a monolayer of graphene.
5. The thermoelectric cooling fin according to claim 1, wherein the nano-metal pins comprise nano-nickel pins and/or nano-copper pins.
6. The thermoelectric cooling fin according to claim 5, wherein the diameter of the cone bottom of the nano metal needle cone is 100-200 nm; the length of the nanometer metal needle cone is 300-500 nm; And the thermocouple pair and the copper-clad substrate are connected through the packaging connecting layer, so that a conductive path is formed.
7. The thermoelectric cooling fin according to claim 5, wherein the thermoelectric cooling fin is obtained by hot-pressing and packaging a copper-clad substrate, a PN thermocouple pair and porous graphene; the pressure of the hot-pressing package is 1-5 MPa; the temperature of the hot-pressing package is 150-250 ℃; one or two sides of the PN type thermocouple pair are compounded with a packaging connecting layer and a copper-clad substrate.
8. The preparation method of the thermoelectric refrigeration sheet is characterized by comprising the following steps of: 1) Preparing a nano metal needle cone structure on the surface of a copper structure layer of the copper-clad substrate to obtain the copper-clad substrate with the nano metal needle cone on the surface; depositing a nickel metal barrier layer on the surface of the semiconductor material, and preparing a nano metal needle cone structure on the nickel metal barrier layer to form a packaging connection surface A; 2) The porous graphene is compounded on the nanometer metal needle cone of the copper-clad substrate with the nanometer metal needle cone on the surface, so as to form a packaging connection surface B; And after the packaging connection surface A and the packaging connection surface B are butted, forming a packaging connection layer through hot pressing packaging, and obtaining the thermoelectric cooling sheet.
9. The method of preparing according to claim 8, wherein the surface comprises two sides; after the packaging connection surface A, the method further comprises the step of cutting cuboid crystal grains; in the step 2), the specific steps of the composite porous graphene include: a) Transferring graphene onto a porous SiN x film by using a transfer medium, removing the transfer medium, and preparing porous graphene by using the porous SiN X film as a template and using a plasma etching method; b) And then transferring the porous graphene onto the copper-clad substrate by using a transfer medium, and removing the transfer medium to obtain the copper-clad substrate compounded with the porous graphene.
10. The preparation method of claim 9, wherein the preparation method of graphene comprises a CVD method; The preparation method of the porous SiN X film comprises photoetching and/or reactive particle etching; the pore diameter of the porous SiN X film is 100-400 nm; The transfer medium comprises PMMA.

Description

High-reliability thermoelectric refrigeration sheet and packaging method thereof Technical Field The invention relates to the technical field of semiconductor thermoelectric refrigeration, relates to a thermoelectric refrigeration sheet and a preparation method thereof, and in particular relates to a high-reliability thermoelectric refrigeration sheet and a packaging method thereof. Background The thermoelectric refrigerating sheet utilizes the Peltier effect of semiconductor materials, and when direct current passes through a couple formed by connecting two different semiconductor materials in series, heat can be respectively absorbed and released at two ends of the couple, so that the purpose of refrigeration is realized. The thermoelectric refrigerating system has no sliding parts, and can be applied to occasions with limited space, high reliability and no refrigerant pollution. Has wide application prospect in the fields of chip thermal management, high-frequency high-speed photoelectric devices, medical treatment, industrial precise temperature control and the like. The structure of the thermoelectric cooling piece mainly comprises a packaging substrate, a P-type thermocouple pair and an N-type thermocouple pair, and a device is formed by utilizing solder connection, but common alloy solder gradually becomes brittle along with the increase of service time, then cracks are formed under the action of thermal stress until the thermoelectric cooling piece fails, and meanwhile, frequent thermal shock also causes defects between the packaging substrate and the solder and between a thermoelectric material and a metallization layer due to thermal mismatch, so that thermoelectric transport performance is affected. Therefore, how to find a suitable way to solve the above-mentioned problems of the existing thermoelectric devices has been one of the focuses of a great deal of prospective researchers in the field. Disclosure of Invention In view of the above, the technical problem to be solved by the present invention is to provide a thermoelectric refrigeration sheet and a method for preparing the same, in particular, a high-reliability thermoelectric refrigeration sheet and a method for packaging the same. According to the invention, the nano needle cone structure layer is constructed on the packaging connection interface, and the porous graphene is used as the flexible layer, so that the solder-free low-temperature metallurgical connection is realized, the interface strength is enhanced, and meanwhile, the formed porous graphene-metal composite structure can effectively regulate and control the thermal stress of the interface, and the damage of the thermal stress to the interface in the service process of the thermoelectric device is reduced. The invention provides a thermoelectric refrigeration piece, which comprises a PN type thermocouple pair with a nickel layer compounded on the surface; the packaging connecting layer is compounded on the PN type thermocouple pair; A copper-clad substrate compounded on the packaging connection layer; The material of the packaging connection layer comprises a porous graphene-metal composite material. Preferably, the number of the PN type thermocouple pairs comprises one or more groups; the PN type thermocouple pair comprises a P type bismuth antimonide cuboid grain thermocouple pair and an N type bismuth antimonide cuboid grain thermocouple pair; The thickness of the nickel layer is 1-3 mu m. Preferably, the copper-clad layer on the surface of the copper-clad substrate is a copper structure layer with a pattern; the copper-clad substrate comprises a copper-clad ceramic substrate; in the porous graphene-metal composite, the metal includes copper and/or nickel. Preferably, the pore diameter of the porous graphene is 100-300 nm; The porous graphene comprises single-layer graphene; The porous graphene-metal composite material comprises porous graphene and a metal needle cone. Preferably, a nano metal needle cone connecting surface A is arranged on the nickel layer on the surface of the thermocouple pair; a nano metal needle cone connecting surface B is arranged on the copper layer on the surface of the copper-clad substrate; The nano metal needle cone connecting surface A, the nano metal needle cone connecting surface B and the porous graphene are packaged in a hot-pressing mode to form the packaging connecting layer; the nanometer metal needle cone comprises a nanometer nickel needle cone and/or a nanometer copper needle cone. Preferably, the diameter of the cone bottom of the nano metal needle cone is 100-200 nm; the length of the nanometer metal needle cone is 300-500 nm; And the thermocouple pair and the copper-clad substrate are connected through the packaging connecting layer, so that a conductive path is formed. Preferably, the thermoelectric cooling sheet is obtained by hot-pressing and packaging a copper-clad substrate, a PN thermocouple pair and porous graphene; the pre