Low-transmission-loss copper-based composite material and preparation method thereof, PCB, and electronic component

1 . A low-transmission-loss copper-based composite material, wherein the low-transmission-loss copper-based composite material comprises: a plurality of lamination units repeatedly stacked in sequence along a preset direction, each of the lamination units comprising a conductor layer and an insulation layer covering a surface of the conductor layer along the preset direction, and wherein the conductor layer comprises a single-crystal copper layer; and

the low-transmission-loss copper-based composite material has a transmission loss of 0.4-0.9 dB/inch at 20 GHz, and the low-transmission-loss copper-based composite material has an impedance of 80-85 Ω.

2 . The low-transmission-loss copper-based composite material according to claim 1 , wherein in each of the lamination units, a thickness ratio of the conductor layer to the insulation layer along the preset direction is (90-95):(5-10).

3 . The low-transmission-loss copper-based composite material according to claim 2 , wherein the number of the lamination units is 5-8;

optionally, a material of the insulation layer comprises boron nitride; and

optionally, surface roughness Rz of the single-crystal copper layer is 0.2-1 μm.

4 . The low-transmission-loss copper-based composite material according to claim 1 , wherein the conductor layer further comprises a graphene layer, and the graphene layer and the single-crystal copper layer are stacked along the preset direction;

optionally, each of the conductor layers comprises one single-crystal copper layer and two graphene layers, and the two graphene layers are respectively located on two opposite sides of the single-crystal copper layer;

optionally, in each of the conductor layers, a thickness ratio of the single-crystal copper layer to the graphene layer along the preset direction is (90-95):(5-10); and

optionally, an electrical conducting rate of the conductor layer is 105-108% IACS.

5 . A PCB, wherein the PCB comprises a signal layer; the signal layer has a signal transmission line structure, and a material of the signal transmission line structure is the low-transmission-loss copper-based composite material according to claim 1 ; and a thickness direction of the signal layer is consistent with the preset direction;

optionally, the PCB further comprises a base and a first composite layer and a second composite layer respectively covering two opposite sides of the base in a thickness direction; the first composite layer and the second composite layer each comprise a first dielectric layer, the signal layer, a second dielectric layer, and a reference layer covering a surface of the base in sequence along the thickness direction of the base; and

optionally, along an extending direction of the signal transmission line structure, a distance between two opposite end points of the signal transmission line structure in the first composite layer and a distance between two opposite end points of the signal transmission line structure in the second composite layer are different.

6 . The PCB according to claim 5 , wherein the signal transmission line structure has a plurality of connected S-shaped transmission units.

7 . The PCB according to claim 6 , wherein a surface width of the signal transmission line structure close to the first dielectric layer is less than a surface width of the signal transmission line structure close to the second dielectric layer, and along a direction pointing from the first dielectric layer to the second dielectric layer, a section of the signal transmission line structure in a width direction is of trapezoid.

8 . The PCB according to claim 5 , wherein a surface width of the signal transmission line structure close to the first dielectric layer is less than a surface width of the signal transmission line structure close to the second dielectric layer, and along a direction pointing from the first dielectric layer to the second dielectric layer, a section of the signal transmission line structure in a width direction is of trapezoid.

9 . A preparation method of the low-transmission-loss copper-based composite material according to claim 1 , wherein the preparation method comprises: pressing together a plurality of conductor layers and a plurality of insulation layers that are stacked along the preset direction.

10 . The preparation method of the low-transmission-loss copper-based composite material according to claim 9 , wherein the step of pressing together comprises: hot-pressing the conductor layers and the insulation layers under a condition of an inert atmosphere, a temperature of 500-1000° C., and a pressure of 10-100 MPa.

11 . The preparation method of the low-transmission-loss copper-based composite material according to claim 10 , wherein a step of forming the conductor layers and the insulation layers stacked along the preset direction comprises: repeating in sequence a step of forming an insulation layer on a conductor layer by vapor deposition or coating; and a step of forming a conductor layer on an insulation layer by vapor deposition;

optionally, a preparation step of the single-crystal copper layer comprises: forming the single-crystal copper layer on a substrate having single-crystal graphene on a surface in an atmosphere of mixed gases of argon and hydrogen and under a temperature condition of 800-1065° C., and peeling the single-crystal copper layer from the substrate, wherein in the mixed gases, a volume ratio of the argon to the hydrogen is (10-20):1;

optionally, the preparation step of the single-crystal copper layer comprises: forming the single-crystal copper layer by atomic deposition on the substrate in the atmosphere of the mixed gases and under the temperature condition of 800-1065° C., and peeling the single-crystal copper layer from the substrate to obtain the single-crystal copper layer, wherein the substrate is a sapphire substrate having single-crystal graphene on a surface;

optionally, the preparation step of the single-crystal copper layer comprises: electroplating copper on the substrate to form an electroplated copper layer, then performing annealing in the atmosphere of the mixed gases and under the temperature condition of 800-1065° C., to make the electroplated copper layer to be converted into the single-crystal copper layer, and peeling the single-crystal copper layer from the substrate to obtain the single-crystal copper layer, wherein the substrate is a single-crystal copper substrate having single-crystal graphene on a surface; and

optionally, the conductor layer further comprises a graphene layer, and the graphene layer and the single-crystal copper layer are stacked along the preset direction; and a preparation method of the graphene layer comprises: growing the graphene layer on the single-crystal copper layer by chemical vapor deposition.

12 . The preparation method of the low-transmission-loss copper-based composite material according to claim 9 , wherein a step of forming the conductor layers and the insulation layers stacked along the preset direction comprises: repeating in sequence a step of forming an insulation layer on a conductor layer by vapor deposition or coating; and a step of forming a conductor layer on an insulation layer by vapor deposition;

optionally, a preparation step of the single-crystal copper layer comprises: forming the single-crystal copper layer on a substrate having single-crystal graphene on a surface in an atmosphere of mixed gases of argon and hydrogen and under a temperature condition of 800-1065° C., and peeling the single-crystal copper layer from the substrate, wherein in the mixed gases, a volume ratio of the argon to the hydrogen is (10-20):1;

optionally, the preparation step of the single-crystal copper layer comprises: forming the single-crystal copper layer by atomic deposition on the substrate in the atmosphere of the mixed gases and under the temperature condition of 800-1065° C., and peeling the single-crystal copper layer from the substrate to obtain the single-crystal copper layer, wherein the substrate is a sapphire substrate having single-crystal graphene on a surface;

optionally, the preparation step of the single-crystal copper layer comprises:

electroplating copper on the substrate to form an electroplated copper layer, then performing annealing in the atmosphere of the mixed gases and under the temperature condition of 800-1065° C., to make the electroplated copper layer to be converted into the single-crystal copper layer, and peeling the single-crystal copper layer from the substrate to obtain the single-crystal copper layer, wherein the substrate is a single-crystal copper substrate having single-crystal graphene on a surface; and

optionally, the conductor layer further comprises a graphene layer, and the graphene layer and the single-crystal copper layer are stacked along the preset direction; and a preparation method of the graphene layer comprises: growing the graphene layer on the single-crystal copper layer by chemical vapor deposition.