Cofiring manufacturing method for lower copper plate and capillary structure of vapor chamber

Abstract

The invention discloses a cofiring manufacturing method for a lower copper plate and a capillary structure of a vapor chamber. The cofiring manufacturing method comprises the following steps: preparing first copper powder and second copper powder; forming the first copper powder at high pressure to generate a lower plate primary blank, wherein the lower plate primary blank is provided with an upper surface; laying second copper powder on the upper surface of the lower plate primary blank; and sintering the lower plate primary blank provided with the second copper powder at a high temperature to generate a high-compactness lower copper plate with a porous capillary structure. Compared with the prior art, the method has the advantages that the capillary structure is formed while the lower copper plate of the uniform-temperature plate is manufactured through the powder metallurgy process, the lower copper plate and the capillary structure of the uniform-temperature plate can be completed at the same time only through one-time sintering, the process time is shortened, the production efficiency is improved, and the cost is reduced.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a copper bottom plate and a capillary structure of a heat spreader, in particular to a method for co-firing a high-density copper bottom plate and a multi-porous capillary structure of a heat spreader by using a powder metallurgy process. Background Art

[0002] The demand for current electronic products is increasing day by day. To meet the needs of consumers and in response to the trend of big data, the performance requirements of the chips applied in electronic devices are also getting higher and higher. Regarding the heat energy on the main heat sources such as AI chips, CPUs or GPUs, the power of a single chip has reached 500W or 700W, and even in the future, there will be a design requirement for high-computing-power chip products with a power exceeding 2,000W. Generally, the faster the computing speed of the chip, the more powerful its performance is, but at the same time, the thermal design power and heat generation of the chip also increase greatly. If the heat of the chip cannot be effectively dissipated, it may cause the chip to overheat, resulting in the chip operating at a reduced frequency or even burning out.

[0003] The commonly known current heat dissipation technologies are divided into air-cooled heat dissipation technologies and liquid-cooled heat dissipation technologies. In the air-cooled heat dissipation technology, the commonly used ones in the industry are mostly heat pipes and vapor chamber heat spreaders (VC) plus heat dissipation fins. However, as the power of a single chip increases day by day, the heat pipe has almost reached its heat dissipation limit. The vapor chamber heat spreader is generally a flat plate shape and can be used to solve two-dimensional heat diffusion problems. But as the power of the chip gets larger and larger, the flat-plate vapor chamber heat spreader component can no longer meet the heat dissipation requirements, and thus a structure of a three-dimensional vapor chamber heat spreader component plus heat dissipation fins appears. By separating the heat absorption area and the condensation area of the two-phase flow cycle on different planes and adding forced convection of a fan to increase the three-dimensional heat dissipation function.

[0004] However, in the manufacturing process of the commonly known three-dimensional vapor chamber heat spreader component, a layer of copper powder is laid on the upper surface of a copper bottom plate and then sintered to obtain a bottom plate with a porous capillary structure. It is also possible to sinter a copper bottom plate by using the powder metallurgy method, and then lay a layer of copper powder on its upper surface and then sinter it to obtain a bottom plate with a porous capillary structure. In the prior art, if the powder metallurgy method is used, a total of two sintering processes are required to obtain the bottom plate and the capillary structure of the heat spreader, and this process requires a large amount of time and energy for the sintering procedure.

[0005] Therefore, it is necessary to provide a method for manufacturing the bottom plate and the capillary structure of a heat spreader that can save processing procedures, reduce time costs, and also reduce the cost of wasting metal raw materials. Summary of the Invention

[0006] In view of this, the object of the present invention is to provide a method for co-firing a copper lower plate and a capillary structure of a heat pipe, which can overcome the defects of the prior art, save processing procedures, reduce time costs, and reduce the cost of wasting metal raw materials.

[0007] To achieve the above object, the present invention discloses a method for co-firing a copper lower plate and a capillary structure of a heat pipe, which is characterized by comprising the following steps:

[0008] (S1) Prepare a first copper powder and a second copper powder;

[0009] (S2) High-pressure form the first copper powder to produce a lower plate blank, wherein the lower plate blank has an upper surface;

[0010] (S3) Lay the second copper powder on the upper surface of the lower plate blank; and

[0011] (S4) High-temperature sinter the lower plate blank provided with the second copper powder to produce a highly dense copper lower plate with a multi-porous capillary structure.

[0012] Among them, in step (S2), the first copper powder is high-pressure formed to produce the lower plate blank, wherein the lower plate blank has the upper surface, the upper surface of the lower plate blank has a groove, and the groove has a groove surface.

[0013] Among them, in step (S3), the second copper powder is laid on the upper surface and the groove surface of the lower plate blank.

[0014] Among them, in step (S4), the lower plate blank provided with the second copper powder is high-temperature sintered to produce the highly dense copper lower plate with the multi-porous capillary structure, so that the multi-porous capillary structure is continuously formed on the upper surface and the groove surface of the highly dense copper lower plate.

[0015] Among them, in step (S2), the first copper powder is high-pressure formed to produce the lower plate blank, wherein the lower plate blank has the upper surface, the upper surface has a plurality of grooves, each groove has a groove surface, there is a groove rib wall between adjacent grooves, and the groove rib wall has a rib wall surface.

[0016] Among them, in step (S3), the second copper powder is laid on the upper surface, the groove surface and the rib wall surface of the lower plate blank.

[0017] Among them, in step (S4), the lower plate blank provided with the second copper powder is high-temperature sintered to produce the highly dense copper lower plate with the multi-porous capillary structure, so that the multi-porous capillary structure is continuously formed on the upper surface, the groove surface and the rib wall surface of the highly dense copper lower plate.

[0018] Among them, step (S2) is to produce the lower plate blank by high-pressure forming the first copper powder, where the lower plate blank has the upper surface and a lower surface, and the lower surface has a downward convex structure.

[0019] Among them, step (S2) is to produce the lower plate blank by high-pressure forming the first copper powder, where the lower plate blank has the upper surface and the lower surface, the lower surface has the downward convex structure, the upper surface of the lower plate blank relative to the downward convex structure has a plurality of grooves, each groove has a groove surface, there is a groove rib wall between adjacent grooves, and the groove rib wall has a rib wall surface.

[0020] Among them, step (S4) is to sinter the lower plate blank provided with the second copper powder using a nitrogen-hydrogen mixed gas at a temperature between 900 and 1,000 degrees Celsius, thereby producing the highly dense copper lower plate with the porous capillary structure, and the highly dense copper lower plate with the porous capillary structure can also be a highly dense copper upper cover with a porous capillary structure.

[0021] In summary, the present invention provides a method for co-firing a copper lower plate and a capillary structure of a heat pipe. After producing the lower plate blank by high-pressure forming the first copper powder, the second copper powder is laid on the upper surface of the lower plate blank. At this time, the lower plate blank provided with the second copper powder is sintered to obtain a highly dense copper lower plate with a porous capillary structure. Compared with the prior art that requires two sintering processes to form the lower plate and the capillary structure of the heat pipe, through the method of the present invention, only one sintering is required to obtain the lower plate and the capillary structure of the heat pipe, so as to greatly reduce the time cost of manufacturing the lower plate of the heat pipe and further improve the production efficiency. In addition, the present invention also provides other aspects of highly dense copper lower plates to meet the requirements of different chip size specifications and designs. Further, the method for co-firing a copper lower plate and a capillary structure of a heat pipe provided by the present invention can also sinter a highly dense copper upper cover with a porous capillary structure, thereby reducing the manufacturing time and cost of the heat pipe components. Description of the Drawings

[0022] Figure 1 The flowchart shows the steps of the method for co-firing a copper lower plate and a capillary structure of a heat pipe according to a specific embodiment of the present invention.

[0023] Figure 2 Shows according to Figure 1 Schematic diagram of the method for co-firing a copper lower plate and a capillary structure of a heat pipe.

[0024] Figure 3 The flowchart shows the steps of the method for co-firing a copper lower plate and a capillary structure of a heat pipe according to another specific embodiment of the present invention.

[0025] Figure 4Shows the flowchart of the steps of the co-firing method of the copper bottom plate and the capillary structure of the heat pipe in another specific embodiment of the present invention.

[0026] Figure 5 Shows the flowchart of the steps of the co-firing method of the copper bottom plate and the capillary structure of the heat pipe in another specific embodiment of the present invention.

[0027] Figure 6 Shows according to Figure 5 Schematic diagram of the co-firing method of the copper bottom plate and the capillary structure of the heat pipe.

[0028] Figure 7A Shows according to Figure 6 Partial top view of the bottom plate blank.

[0029] Figure 7B Shows according to Figure 6 Partial top view of the bottom plate blank.

[0030] Figure 8 Shows the flowchart of the steps of the co-firing method of the copper bottom plate and the capillary structure of the heat pipe in another specific embodiment of the present invention.

[0031] Figure 9 Shows according to Figure 8 Schematic diagram of the co-firing method of the copper bottom plate and the capillary structure of the heat pipe. Detailed Description of the Invention

[0032] In order to make the advantages, spirit and features of the present invention easier and clearer to understand, the following will be described in detail and discussed with reference to specific embodiments and the accompanying drawings. It should be noted that these specific embodiments are only representative specific embodiments of the present invention, and the specific methods, devices, conditions, materials, etc. exemplified therein are not intended to limit the present invention or the corresponding specific embodiments. Also, the elements in the drawings are only used to express their relative positions and are not drawn according to their actual proportions. The step numbers of the present invention are only used to distinguish different steps and do not represent the order of the steps. This is stated first for clarification.

[0033] Please refer to Figure 1 and Figure 2 , Figure 1 Shows the flowchart of the steps of the co-firing method of the copper bottom plate and the capillary structure of the heat pipe in a specific embodiment of the present invention. Figure 2 Shows according to Figure 1 Schematic diagram of the co-firing method of the copper bottom plate and the capillary structure of the heat pipe. As Figure 1 and Figure 2 shown, the co-firing method of the copper bottom plate and the capillary structure of the heat pipe of the present invention includes the following steps:

[0034] Step (S1): Prepare the first copper powder 10 and the second copper powder 20;

[0035] Step (S2): High-pressure mold the first copper powder 10 to produce a lower plate blank 30, wherein the lower plate blank 30 has an upper surface 301;

[0036] Step (S3): Lay the second copper powder 20 on the upper surface 301 of the lower plate blank 30; and

[0037] Step (S4): High-temperature sinter the lower plate blank 300 provided with the second copper powder 20 to produce a highly dense copper lower plate 40 having a multi-porous capillary structure 50.

[0038] Among them, in this specific embodiment, during the high-temperature sintering process, the contact surfaces of the first copper powder 10 and the second copper powder 20 will be further joined together, that is, the contact surface between the second copper powder 20 and the upper surface 301 of the lower plate blank 30. Therefore, when the sintering is completed, the second copper powder 20 is integrally formed into a multi-porous capillary structure 50; the lower plate blank 300 is formed into a highly dense copper lower plate 40. And, since the second copper powder forms a multi-porous capillary structure after sintering, the particle size of the copper powder of the second copper powder in the present invention is larger than the particle size of the copper powder of the first copper powder. The larger-sized powder can become a capillary structure with larger pores, so that the working fluid inside the heat pipe can easily flow back to the bottom inside the heat pipe after the heat pipe is made. The method for co-sintering the copper lower plate and the capillary structure of the heat pipe in the present invention directly performs high-temperature sintering on the lower plate blank 300 provided with the second copper powder 300 at the same time. Compared with the prior art that requires two sintering procedures to form the lower plate of the heat pipe, the method of the present invention only needs to be sintered once to obtain the lower plate of the heat pipe, so as to greatly reduce the time cost of manufacturing the lower plate of the heat pipe and thus improve the production efficiency.

[0039] Furthermore, the present invention provides another method for co-sintering the copper lower plate and the capillary structure of the heat pipe, which increases the limit of the sintering temperature, so as to further improve the overall production yield. Please refer to Figure 2 and Figure 3 , Figure 3 which shows a flowchart of the steps of the method for co-sintering the copper lower plate and the capillary structure of the heat pipe according to another specific embodiment of the present invention. As Figure 3 shown, the method for co-sintering the copper lower plate and the capillary structure of the heat pipe in this specific embodiment includes the following steps:

[0040] Step (S1): Prepare the first copper powder 10 and the second copper powder 20;

[0041] Step (S2): High-pressure mold the first copper powder 10 to produce a lower plate blank 30, wherein the lower plate blank 30 has an upper surface 301;

[0042] Step (S3): Lay the second copper powder 20 on the upper surface 301 of the lower plate blank 30; and

[0043] Step (S40): Sinter the lower plate blank 300 provided with the second copper powder 20 by using a nitrogen-hydrogen mixed gas at a temperature between 900 and 1,000 degrees Celsius, thereby generating a highly dense copper lower plate 40 having a porous capillary structure 50.

[0044] Furthermore, from the above-mentioned sintering of the blank structure provided with the second copper powder by using a nitrogen-hydrogen mixed gas at a temperature between 900 and 1,000 degrees Celsius, a highly dense copper upper cover with a porous capillary structure can also be further sintered and formed. For example, after the first copper powder is formed by high-pressure molding to generate a blank structure, then the second copper powder is laid on the inner surface of the blank structure, and a highly dense copper upper cover with a porous capillary structure can be obtained after high-temperature sintering. When the highly dense copper upper cover with a porous capillary structure and the highly dense copper lower plate with a porous capillary structure are further coupled, evacuated, and injected with a working fluid, a heat pipe is formed. For another example, after the first copper powder is formed by high-pressure molding to generate a blank structure, the blank structure further has a substrate cavity structure and a hollow tube structure at this time. Then the second copper powder is laid on the inner surfaces of the substrate cavity structure and the hollow tube structure of the blank structure. After high-temperature sintering, a porous capillary structure will be continuously formed on the inner surface of the highly dense copper upper cover. Then, when the highly dense copper upper cover in this state and the highly dense copper lower plate with a porous capillary structure are further coupled, evacuated, and injected with a working fluid, it is a three-dimensional heat pipe element (three-dimensional vapor chamber, 3D VC).

[0045] Furthermore, the copper lower plate of the present invention can be further adjusted to different forms according to actual design requirements. Please refer to Figure 4 , Figure 4 which shows a flowchart of the steps of the method for co-firing the copper lower plate and the capillary structure of the heat pipe according to another specific embodiment of the present invention. As Figure 4 shown, the method for co-firing the copper lower plate and the capillary structure of the heat pipe in this specific embodiment includes the following steps:

[0046] Step (S1): Prepare the first copper powder and the second copper powder;

[0047] Step (S21): High-pressure mold the first copper powder to generate a lower plate blank, wherein the lower plate blank has an upper surface, the upper surface of the lower plate blank has a groove, and the groove has a groove surface;

[0048] Step (S31): Lay the second copper powder on the upper surface and the groove surface of the lower plate blank; and

[0049] Step (S41): Sinter the lower plate blank with the second copper powder at a high temperature to produce a highly dense copper lower plate with a porous capillary structure, so that the porous capillary structure is continuously formed on the upper surface and the groove surface of the highly dense copper lower plate.

[0050] In practice, the first copper powder can be placed in a mold with a bump structure. After being tightly pressed under high pressure, a lower plate blank with a groove structure can be obtained. Then, the second copper powder is laid on the upper surface and the groove surface of the lower plate blank. After sintering, a highly dense copper lower plate with a porous capillary structure is obtained. The highly dense copper lower plate with a porous capillary structure in this specific embodiment is then joined to the corresponding upper plate, injected with a working fluid, and evacuated to form a heat pipe. This heat pipe has a large cavity inside. When actually attached to a wafer (i.e., a heat source), it can provide better heat dissipation efficiency.

[0051] In the above embodiment, the lower plate blank has only one groove. However, the number of grooves is not limited to this. The present invention also provides another specific embodiment of the copper lower plate and the capillary structure of the heat pipe. Please refer to Figure 5 、 Figure 6 、 Figure 7A And Figure 7B , Figure 5 which shows a flowchart of the steps of the co-firing method of the copper lower plate and the capillary structure of the heat pipe according to another specific embodiment of the present invention, Figure 6 shows according to Figure 5 a schematic diagram of the co-firing method of the copper lower plate and the capillary structure of the heat pipe, Figure 7A shows according to Figure 6 a partial top view of the lower plate blank 31, Figure 7B shows according to Figure 6 a partial top view of the lower plate blank 310. As Figure 5 、 Figure 6 shown, the co-firing method of the copper lower plate and the capillary structure of the heat pipe in this specific embodiment includes the following steps:

[0052] Step (S1): Prepare the first copper powder 10 and the second copper powder 20;

[0053] Step (S22): High-pressure form the first copper powder 10 to produce a lower plate blank 31, where the lower plate blank 31 has an upper surface 301, the upper surface 301 has a plurality of grooves 3011, each groove 3011 has a groove surface 3012, there are groove rib walls 3013 between adjacent grooves 3011, and the groove rib walls 3013 have rib wall surfaces 3014;

[0054] Step (S32): Lay the second copper powder 20 on the upper surface 301, the groove surface 3012, and the rib wall surface 3014 of the lower plate blank 31; and

[0055] Step (S42): High-temperature sintering of the lower plate green body 310 provided with the second copper powder 20 to produce a highly dense copper lower plate 41 having a porous capillary structure 51, so that the porous capillary structure 51 is continuously formed on the upper surface 301, the groove surface 3012, and the rib wall surface 3014 of the highly dense copper lower plate 41.

[0056] Next, please refer to Figure 6 , Figure 7A and Figure 7B . Figure 6 All the figures shown in Figure 6 are represented in the front view, and Figure 7A the line A-A in Figure 7B corresponds to the range of the partial longitudinal section of Figure 7A and Figure 7B , that is, the partial range when viewed from above. Please refer to Figure 6 and Figure 7A together. After the first copper powder 10 is hot-pressed into the lower plate green body 31, the upper surface 301 of the lower plate green body 31 has 9 grooves 3011, and each groove 3011 has a groove rib wall 3013 adjacent to the groove 3011, which includes the rib wall surface 3014. Next, please refer to Figure 6 and Figure 7B together. Then, the second copper powder 20 is laid on the upper surface 301, the groove surface 3012, and the rib wall surface 3014 of the lower plate green body 31. Figure 7B is a schematic diagram after laying the second copper powder 20, that is, a partial top view of the lower plate green body 310 provided with the second copper powder 20. The number of grooves in this specific embodiment is 9, but the number, size, shape, and position of the grooves are not limited thereto.

[0057] Furthermore, when the entire heat pipe is disposed on the wafer (i.e., the heat source), however, the height of the components around the wafer is relatively high, resulting in a limitation on the structural size of the entire heat pipe. The present invention also provides the states of the copper lower plate and the capillary structure of the heat pipe in other specific embodiments. Please refer to Figure 8 and Figure 9 . Figure 8 shows a flowchart of the steps of the co-firing method of the copper lower plate and the capillary structure of the heat pipe according to another specific embodiment of the present invention. Figure 9 shows Figure 8 a schematic diagram of the co-firing method of the copper lower plate and the capillary structure of the heat pipe according to Figure 8 and Figure 9 shown. As

[0058] Step (S1): Prepare the first copper powder 10 and the second copper powder 20;

[0059] Step (S231): High-pressure mold the first copper powder 10 to produce a lower plate blank 32, wherein the lower plate blank 32 has an upper surface 301 and a lower surface 302, and the lower surface 302 has a lower convex structure 303;

[0060] Step (S232): High-pressure mold the first copper powder 10 to produce a lower plate blank 32. The lower plate blank 32 has an upper surface 301 and a lower surface 302, the lower surface 302 has a lower convex structure 303, the lower plate blank 32 has a plurality of grooves 3011 on the upper surface 301 relative to the lower convex structure 303, each groove 3011 has a groove surface 3012, there are groove rib walls 3013 between adjacent grooves 3011, and the groove rib walls 3013 have rib wall surfaces 3014;

[0061] Step (S32): Lay the second copper powder 20 on the upper surface 301, the groove surface 3012 and the rib wall surface 3014 of the lower plate blank 32; and

[0062] Step (S42): High-temperature sinter the lower plate blank 320 provided with the second copper powder 20 to produce a highly dense copper lower plate 42 with a porous capillary structure 52, so that the porous capillary structure 52 is continuously formed on the upper surface 301, the groove surface 3012 and the rib wall surface 3014 of the highly dense copper lower plate 42.

[0063] Wherein, in this specific embodiment, an upper mold and a lower mold each having a convex structure can be prepared, the first copper powder is respectively laid in the upper mold and the lower mold, and after high-pressure close pressing, a lower plate blank 32 with 9 groove structures 3011 and 1 lower convex structure 303 can be obtained. Note that the number of grooves, the size and the size of the lower convex structure (i.e., length, width, height) in this specific embodiment are not limited thereto.

[0064] In summary, the present invention provides a method for co-firing a copper lower plate and a capillary structure of a heat pipe. After generating a lower plate embryo by high-pressure forming of the first copper powder, the second copper powder is laid on the upper surface of the lower plate embryo. At this time, the lower plate embryo provided with the second copper powder is sintered to obtain a highly dense copper lower plate with a multi-porous capillary structure. Compared with the prior art that requires two sintering processes to form the lower plate and the capillary structure of the heat pipe, through the method of the present invention, only one sintering is required to obtain the lower plate and the capillary structure of the heat pipe, so as to greatly reduce the time cost of manufacturing the lower plate of the heat pipe and further improve the production efficiency. In addition, the present invention also provides other aspects of highly dense copper lower plates to meet the requirements of different chip size specifications and designs. Further, the method for co-firing a copper lower plate and a capillary structure of a heat pipe provided by the present invention can also sinter a highly dense copper upper cover with a multi-porous capillary structure, thereby reducing the manufacturing time and cost of the heat pipe components.

[0065] From the detailed description of the above preferred specific embodiments, it is hoped that the features and spirit of the present invention can be more clearly described, rather than limiting the scope of the present invention by the above-disclosed preferred specific embodiments. On the contrary, the purpose is to hope to cover various changes and equivalent arrangements within the scope of the patent application of the present invention. Therefore, the scope of the patent application of the present invention should be interpreted as broadly as possible according to the above description, so as to cover all possible changes and equivalent arrangements.

Claims

1. A method for co-firing a copper bottom plate and a capillary structure of a heat pipe, characterized in that It includes the following steps: (S1) Prepare a first copper powder and a second copper powder; (S2) High-pressure form the first copper powder to generate a lower plate blank, wherein the lower plate blank has an upper surface; (S3) Lay the second copper powder on the upper surface of the lower plate blank; and (S4) High-temperature sinter the lower plate blank provided with the second copper powder to generate a highly dense copper lower plate having a porous capillary structure.

2. The method for co-firing a copper bottom plate and a capillary structure of a heat pipe according to claim 1, characterized in that, Step (S2) is to high-pressure form the first copper powder to generate the lower plate blank, wherein the lower plate blank has the upper surface, the upper surface of the lower plate blank has a groove, and the groove has a groove surface.

3. The method for co-firing a copper bottom plate and a capillary structure of a heat pipe according to claim 2, characterized in that, Step (S3) is to lay the second copper powder on the upper surface and the groove surface of the lower plate blank.

4. The method for co-firing a copper bottom plate and a capillary structure of a heat pipe according to claim 3, characterized in that, Step (S4) is to high-temperature sinter the lower plate blank provided with the second copper powder to generate the highly dense copper lower plate having the porous capillary structure, so that the porous capillary structure is continuously formed on the upper surface and the groove surface of the highly dense copper lower plate.

5. The method for co-firing a copper bottom plate and a capillary structure of a heat pipe according to claim 1, characterized in that, Step (S2) is to high-pressure form the first copper powder to generate the lower plate blank, wherein the lower plate blank has the upper surface, the upper surface has a plurality of grooves, each groove has a groove surface, there is a groove rib wall between adjacent grooves, and the groove rib wall has a rib wall surface.

6. The method for co-firing a copper bottom plate and a capillary structure of a heat pipe according to claim 5, characterized in that, Step (S3) is to lay the second copper powder on the upper surface, the groove surface and the rib wall surface of the lower plate blank.

7. The method for co-firing a copper bottom plate and a capillary structure of a heat pipe according to claim 6, characterized in that, Step (S4) is to high-temperature sinter the lower plate blank provided with the second copper powder to generate the highly dense copper lower plate having the porous capillary structure, so that the porous capillary structure is continuously formed on the upper surface, the groove surface and the rib wall surface of the highly dense copper lower plate.

8. The method for co-firing a copper bottom plate and a capillary structure of a heat pipe according to claim 1, characterized in that, Step (S2) is to high-pressure form the first copper powder to generate the lower plate blank, wherein the lower plate blank has the upper surface and a lower surface, and the lower surface has a downward convex structure.

9. The method for co-firing a copper bottom plate and a capillary structure of a heat pipe according to claim 8, characterized in that, Step (S2) is to high-pressure form the first copper powder to generate the lower plate blank, wherein the lower plate blank has the upper surface and the lower surface, the lower surface has the downward convex structure, the upper surface of the lower plate blank relative to the downward convex structure has a plurality of grooves, each groove has a groove surface, there is a groove rib wall between adjacent grooves, and the groove rib wall has a rib wall surface.

10. The method for co-firing a copper bottom plate and a capillary structure of a heat pipe according to claim 1, characterized in that, Step (S4) is to sinter the lower plate blank provided with the second copper powder with a nitrogen-hydrogen mixed gas at a temperature between 900 and 1,000 degrees Celsius, thereby generating the highly dense copper lower plate having the porous capillary structure, and the highly dense copper lower plate with the porous capillary structure can also be a highly dense copper upper cover with a porous capillary structure.

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