Heat management structure with graphene and copper, and a formation method thereof

Abstract

The invention relates to a heat management structure with graphene and copper, and a formation method thereof, comprising a copper foil layer provided, then forming a graphene layer on the copper foil layer surface, and forming an electroplating copper layer on the graphene layer surface, and eventually forming an electroplating copper layer-graphene layer-copper foil layer sandwich heat management structure.

Claims

1. A method for forming a heat management structure with graphene and copper, comprising: providing a first electrochemical system, the first electrochemical system comprising a first potentiostat connected to a first cathode provided with a graphite rod, a first anode provided with a graphite rod, and a saturated calomel electrode as a first reference electrode, the first cathode, the first anode and the reference electrode being immersed in an electrolyte solution of potassium hydroxide; applying a potential to the first anode to perform an electrochemical water decomposition reaction, wherein a graphene of said graphite rod undergoes a delamination reaction; performing a centrifuge process for said electrolyte solution of potassium hydroxide, wherein a deionized water is used for washing to obtain washed graphene; dispersing the washed graphene in alcohol to obtain a graphene dispersion solution; spraying said graphene dispersion solution on a copper foil surface, and drying the graphene dispersion on the copper foil surface to form a a double-layer structure comprised of a graphene layer and a copper foil layer; providing a second electrochemical system, the second electrochemical system comprising said double-layer structure as a second cathode, a platinum as a second anode, and a saturated calomel electrode as a second reference electrode, the second cathode, the second anode and the second reference electrode being immersed in a copper sulfate solution, an electroplating copper layer being deposited by electrodeposition on said double-layer structure; and washing and drying said double-layer structure to obtain a three-layered structure comprising said electroplating copper layer, said graphene layer and said copper foil as a sandwich-style heat management structure.

2. The method according to claim 1, wherein said second electrolyte solution in said second electrochemical system comprises 1 M sulfuric acid containing 50 mM copper sulfate.

3. The method according to claim 1, wherein said second electrochemical system comprises a current setting of 10 mA.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

(2) FIG. 1 illustrates a first electrochemical system of the invention.

(3) FIG. 2 illustrates the flow diagram for a method of forming a heat management structure with the graphene and the copper according to the invention.

(4) FIG. 3A illustrates a layered structure of the electroplating copper, graphene and copper foil sandwich heat management structure of the invention.

(5) FIG. 3B illustrates a layered structure of the electroplating copper, graphene and copper foil sandwich continuous heat management structure of the invention.

(6) FIG. 4 illustrates a second electrochemical system of the invention.

(7) FIG. 5 illustrates a heat management test diagram of the invention.

(8) FIG. 6 illustrates a heat management temperature-time diagram of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

(9) Please refer to the accompanying figures below for instruction and description, in order to describe the embodiments of the invention according to the schematic diagrams. In the schematic diagrams, the same element symbol represents the same element, and the size or thickness of element may be exaggerated for clarity.

(10) The invention relates to a method for forming a heat management structure with graphene and copper. As shown in in FIG. 1, a first electrochemical system 100 with a first potentiostat 120 is provided, which can be connected to a first cathode 101 provided with a graphite rod, and a first anode 102 provided with a graphite rod, and a saturated calomel electrode 103 is used as the first reference electrode 103. In here, the function of the first reference electrode is to measure the potential of test piece in the current environment, wherein the reference electrode is not affected by the external environment and is maintained at a fixed potential.

(11) Still referring to FIG. 1, in the first electrochemical system 100, a first electrolyte solution 160 of potassium hydroxide (KOH) with a concentration of 1 N is added to form the first electrochemical system 100.

(12) Turning to FIG. 2, an anodic potential of 2 V is applied in Step 201 to perform an electrochemical water decomposition reaction.

(13) At the same time, the graphene of graphite rod will undergo a delamination reaction and gradually darken the color of the first potassium hydroxide electrolyte solution 160 as graphene is dispersed into the electrolyte solution 160.

(14) At Step 202, a centrifuge process of graphene in the potassium hydroxide first electrolyte 160 is performed, and deionized water is used for washing the precipitated graphene to remove potassium hydroxide. The centrifuge and wash processes are repeated several times for purifying the graphene

(15) In Step 203, the graphene precipitate is dispersed in alcohol to become a graphene dispersion solution.

(16) In step 204, the graphene dispersion solution is sprayed on the copper (Cu) foil surface of about 1 cm4 cm in size, and dried to become a double-layer structure having a graphene 302 layer and a copper foil 301 layer as shown in FIG. 3A.

(17) In step 205, in the second electrochemical system 400 of FIG. 4, a second potentiostat 420 is provided, and the graphene 302 and copper foil 301 double-layer structure is used as a second cathode 401, platinum (Pt) is used as a second anode 402, and the second reference electrode 403 is again a saturated calomel electrode. In the second electrolyte solution 460, at a concentration of 1 M sulfuric acid containing 50 mM copper sulfate, the electroplating copper is deposited by electrodeposition. At this time, the current can be set to 10 mA, and the deposition is carried out for several minutes to form the electroplating copper layer 303 on the graphene layer 302, and then the reaction is stopped.

(18) Finally, in step 206, the cathode is washed and dried to obtain the three layered arrangement of the copper foil layer 301, the graphene layer 302 and the electroplating copper layer 303, as a sandwich-style heat management structure as shown in FIG. 3B.

(19) In other embodiments of the three-layered heat management structure shown in FIG. 3B, the copper foil layer 301 can be replaced by other metals, including but not limited to gold, silver, aluminum, and various metals and related alloys.

(20) Also, in other embodiments of the three-layered heat management structure shown in FIG. 3B, the graphene layer 302 can be replaced by natural graphite flakes, artificial graphite flakes, nanocarbon, graphene derivatives, and nanocarbon derivatives.

(21) Further, in other embodiments of the three-layered heat management structure shown in FIG. 3B, the electroplating copper layer 303 can be replaced by other metals, which may include but are not limited to gold, silver, aluminum, and various metals and related alloys.

(22) In the heat management structure, preferably, the thickness of copper foil layer 301 is 200 m to 5000 m, the thickness of graphene layer 302 is 1 nm to 100 nm, and the thickness of electroplating copper layer 303 is 200 nm to 1000 nm.

(23) The heat management test is performed by pumping current to the resistor covered by a heat dissipation structure. Due to Joule heating, the temperature of the resistor will increase. However, this heat will be dissipated and a steady state temperature will be achieved. In FIGS. 5 and 6, results of heat management tests comparing five different heat management structures are shown. The tests consist of determining a maximum temperature, temperature rise time and cooling or fall time for each of the tested structures. FIG. 5 shows the temperature of the resistor under constant current within 0 to 3500 frames and with turning off current after 3500 frames. If the heat dissipation structure can effectively remove the heat, the steady state temperature of the resistor will be lower. If the heat dissipation structure can channel the heat fast, the time to reach steady state temperature and the flow of the temperature when current is turned off will be faster. FIG. 5 and FIG. 6 show a comparison of various heat dissipation structures. After introducing thermal management of Cu-Gr and Cu-Gr-foam, it can significantly reduce the temperature of the resistor under the current supply, and it can quickly return to room temperature after power off. This result shows that our invented structure is the best. The x-axis is shows time in frames (1000 means 1000 frames). In the tests, one frame is 1/50 seconds, and hence 1000 frames is equivalent to 20 seconds.

(24) The heat measurement structures tested include 1) no heat management structure (no base) 501; 2) a copper foil (Cu) heat management structure 502 alone; 3) an electroplating copper (labeled Cu foam in the drawing) heat management structure 503, a copper foil (Cu) and graphene (Gr) layered heat management structure 504; and 5) the copper foil layer 301, graphene layer 302 and electroplating copper layer 303 three-layered heat management structure 505 of the invention. From the diagram, it can be seen that it only takes 3 seconds for the temperature to drop to room temperature for the electroplating copper layer (Cu foam)-graphene layer (Gr)-copper foil layer (Cu) as a sandwich-style heat management structure 505 of the invention, indicating that the proposed heat management device has the best heat management effect. It is understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth herein, but rather that the claims be construed as encompassing all the features of patentable novelty that reside in the present invention, including all features that would be treated as equivalents thereof by those skilled in the art to which this invention pertains.