3D printed copper circuit board radiator based on TPMS structure and preparation method thereof

Abstract

The present invention discloses a 3D printed copper circuit board radiator based on a TPMS structure and a preparation method thereof, which comprises a TPMS porous structure, and the relative density of the TPMS unit cell structure is adjusted based on the unit cell structure formula of the TPMS lattice material, and the above formula is input into the K3DSurf software to obtain the unit cell structure surface of the TPMS lattice material, and the CAD file in the obj format is exported, converted into the stl format and Boolean operation is implemented in the UG software to obtain a three-dimensional TPMS porous structure, which intersects with the block as a single-channel circuit board radiator model, and is obtained by green laser 3D printing using pure copper as a 3D printing material. The present invention uses TPMS as a porous structure of the radiator, and the average curvature of each point is zero, the specific surface area is large, and the pore diameter is relatively uniform, which is conducive to improving the heat dissipation efficiency of the radiator, and at the same time overcomes the problems of low laser energy absorption rate and printing difficulty of 3D printing pure copper materials.

Description

Technical Field

[0001] The present invention belongs to the field of 3D printing, and in particular relates to a 3D printed copper circuit board radiator based on a TPMS structure and a preparation method thereof. Background Art

[0002] In recent years, researchers have tried to design and manufacture porous structures using triperiodic minimal surfaces (TPMS). TPMS is a periodic smooth implicit surface with a mean curvature of zero. Compared with other types of porous structures, TPMS porous structures have two obvious advantages: (1) The overall TPMS porous structure can be accurately described using mathematical expressions, and basic properties such as porosity and specific surface area can be directly controlled using function expression parameters; (2) The TPMS surface is very smooth, without sharp turns or connection points of the lattice porous structure, and the overall structure is interconnected. However, there are still many problems that need to be solved in the key links of design, manufacturing and application of TPMS porous structures.

[0003] Additive manufacturing technology is an ideal method for manufacturing intricate TPMS porous structures. Currently, various processes are available for manufacturing TPMS porous structures, including selective laser melting (SLM), selective laser sintering (SLS), photo-curing (SLA), digital light processing (DLP), fused deposition modeling (FDM), etc. By selecting appropriate materials and processing techniques, various high-precision TPMS porous structures can be manufactured, such as TPMS porous structure energy buffer devices, TPMS tissue engineering scaffolds, medical implants, TPMS porous structure absorbers, etc. Most of the traditional radiator porous structures are mainly herringbone plates, convex plates, plate-fin plates and topological plates, with small specific surface areas and low heat dissipation efficiency. Usually, in order to take into account certain mechanical properties, a certain porosity needs to be sacrificed. Among them, the circuit board radiator is the medium for heat exchange between the heat source and the air. Unlike the dual-channel radiator that requires heat exchange between two solvents, the circuit board radiator only needs one channel. Existing 3D printed heat sinks have not yet adopted a TPMS structure with a large specific surface area. The TPMS structure is currently used for structural material design and implant design, and has not yet been used to prepare circuit board heat sinks. Summary of the invention

[0004] The main purpose of the present invention is to provide a 3D printed copper circuit board heat sink based on the TPMS structure, using pure copper as the 3D printing material and adopting the TPMS porous structure design.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned 3D printed copper circuit board heat sink based on the TPMS structure.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] The 3D printed copper circuit board heat sink based on the TPMS structure provided by the present invention comprises a TPMS porous structure and uses pure copper as a substrate.

[0008] Preferably, the TPMS porous structure is a Fischer Koch structure.

[0009] The present invention also provides a method for preparing the above-mentioned 3D printed copper circuit board heat sink based on the TPMS structure, comprising the following steps:

[0010] Step 1: The unit cell structure of the TPMS lattice material satisfies the formula shown in the following table, and the relative density of the TPMS unit cell structure is adjusted based on the formula;

[0011]

[0012]

[0013] Step 2: Input the formula shown in step 1 into the K3DSurf software to obtain the surface of the unit cell structure of the TPMS lattice material, and export the CAD file in obj format;

[0014] Step 3: Convert the CAD file in obj format described in step 2 into a CAD file in stl format, implement Boolean operation in UG software, obtain a three-dimensional TPMS porous structure, and convert it into stl format;

[0015] Step 4, the three-dimensional TPMS porous structure and the block intersect to form a single-channel circuit board heat sink model;

[0016] Step 5: Use pure copper as the 3D printing material and use a green laser printer to 3D print the single-channel circuit board heat sink model.

[0017] Preferably, the process parameters of the green laser 3D printing are shown in the following table:

[0018]

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The present invention uses TPMS as the porous structure of the radiator. The average curvature of each point of the structure is zero, and the specific surface area is much higher than that of the porous structure of the traditional radiator, which can improve the heat dissipation efficiency.

[0021] (2) In the 3D printed copper circuit board heat sink based on the TPMS structure of the present invention, a Fischer Koch porous structure can be used, which has a large specific surface area and a relatively uniform pore diameter, which is beneficial to improving the heat dissipation efficiency of the heat sink.

[0022] (3) The present invention uses green laser 3D printing of pure copper materials to prepare a heat sink based on a TPMS structure, which can effectively improve the energy absorption of copper powder and overcome the problems of low laser energy absorption rate and printing difficulty of pure copper during 3D printing.

[0023] (4) The present invention adopts green laser 3D printing with the characteristics of rapid cooling, large temperature gradient and thermal cycle. The prepared pure copper heat sink has smaller grains and larger yield strength, which is conducive to providing self-support. It can also increase the porosity while ensuring the strength, further improving the heat dissipation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of a typical TPMS unit cell microstructure.

[0025] Figure 2 It is a schematic structural diagram of a circuit board heat sink model in which a three-dimensional TPMS porous structure and a block (A side or B side) intersect as a single channel in an embodiment.

[0026] Figure 3 Schematic diagram of the structure of the TPMS radiator prepared in the embodiment and the traditional radiator.

[0027] Figure 4 Surface area comparison of the six structures of the heat sink in the embodiment.

[0028] Figure 5 This is a physical picture of the heat sink printed by infrared laser 3D printing in the embodiment.

[0029] Figure 6 This is a real picture of the heat sink printed by green laser 3D printing in the embodiment.

[0030] Figure 7 This is a physical picture of the Fischer Koch structure heat sink in the embodiment assembled on the circuit board. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention is clearly and completely described below. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] This embodiment provides a method for preparing a 3D printed copper circuit board heat sink based on a TPMS structure, which includes a TPMS porous structure and uses pure copper as a substrate, and the steps are as follows:

[0034] Step 1: The unit cell structure of the TPMS lattice material satisfies the formula shown in Table 1, and the relative density of the TPMS unit cell structure is adjusted based on the formula;

[0035] Table 1: Unit cell structure formula of TPMS lattice materials

[0036]

[0037]

[0038] Step 2: Input the formula shown in step 1 into the K3DSurf software to obtain the surface of the unit cell structure of the TPMS lattice material, and export the CAD file in obj format;

[0039] Step 3: Convert the CAD file in obj format described in step 2 into a CAD file in stl format, implement Boolean operation in UG software, obtain a three-dimensional TPMS porous structure, and convert it into stl format;

[0040] Step 4, the above three-dimensional TPMS porous structure and the block are intersected to form a single-channel circuit board heat sink model;

[0041] Step 5: Using pure copper as the 3D printing material, the single-channel circuit board heat sink model is 3D printed using a green laser printer. The process parameters are shown in Table 2:

[0042]

[0043] like Figure 1 As shown, the typical TPMS unit cell microstructure includes a single channel (almost rod-like) and a double channel (almost plate-like), and the average curvature of the TPMS is zero.

[0044] like Figure 2 As shown, the circuit board heat sink is the medium for heat exchange between the heat source and the air. Different from the dual-channel heat sink required for heat exchange between two solvents, the circuit board heat sink only needs one channel. Figure 1 Both rod-type and plate-type TPMS can be used as circuit board heat sinks. Taking the rod-type TPMS as an example, by intersecting the TPMS and the block, the block on the A side or the B side can be used as a single-channel heat sink ( Figure 2 ).

[0045] like Figure 3As shown, the TPMS radiator and the traditional radiator have the same base structure, and the porosity of the porous structure is about 61.5%, that is, the porosity of these structures is consistent. The gradient Gyroid structure is designed with three layers of Gyroid structures with different densities, but its final porosity is consistent with other designs. This gradient design can balance the contact between the structure and the air and the conductivity of the structure itself.

[0046] like Figure 4 As shown in the figure, the surface areas of the six designed radiators are compared. Because the porosity is consistent, that is, the volume is consistent, their surface areas can be directly compared. It can be seen that the surface area of ​​the TPMS radiator has a great advantage over the traditional radiator.

[0047] Figure 5 and Figure 6 These are the actual pictures of the radiator printed using infrared laser and green laser 3D printing respectively.

[0048] Figure 7 This is a physical picture of assembling a Fischer Koch structure copper heat sink on a circuit board.

[0049] The above description of the embodiments is to facilitate the understanding and use of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without having to go through creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the principles of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A 3D printed copper circuit board heat sink based on the TPMS structure, characterized in that: It contains a TPMS porous structure, which is obtained by green laser 3D printing using pure copper as the 3D printing material; The TPMS porous structure is a Fischer Koch structure; The method for preparing the 3D printed copper circuit board radiator based on the TPMS structure comprises the following steps: Step 1: The unit cell structure of the TPMS lattice material satisfies the formula shown in the following table, and the relative density of the TPMS unit cell structure is adjusted based on the formula; Step 2: Enter the formula shown in step 1 in the K3DSurf software to obtain the surface of the unit cell structure of the TPMS lattice material and export obj CAD files in . Step 3, as described in step 2 obj CAD files in . stl Format CAD file, perform Boolean operation in UG software, obtain the three-dimensional TPMS porous structure, and export it as stl Format; Step 4, the three-dimensional TPMS porous structure and the block intersect to form a single-channel circuit board heat sink model; Step 5: Using pure copper as the 3D printing material, a green laser printer is used to perform 3D printing on the single-channel circuit board heat sink model; the process parameters of the green laser 3D printing are shown in the following table: 。

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