A method for resin plug hole of a power board copper block

Abstract

This invention relates to a method for resin plugging of copper blocks in a power board, comprising the following steps: S1, providing a copper block substrate; S2, drilling positioning holes and through holes in the copper block substrate; S3, plugging the drilled copper block substrate with resin; S4, cutting the plugged and ground copper block substrate into multiple finished copper blocks; S5, placing the finished copper blocks into a PCB lamination structure. This invention avoids the traditional method of requiring individual fixtures for plugging each small copper block by first drilling and resin plugging the entire large copper block substrate, and then cutting and separating them into finished copper blocks. This solves the problems of difficult operation, high fixture cost, and low processing efficiency for plugging small copper blocks. Furthermore, the large copper block substrate is easier to clamp and distribute force evenly during grinding, significantly improving the quality stability of resin plugging and overall production efficiency.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board technology, and more specifically, to a method for resin plugging of copper blocks in power supply boards. Background Technology

[0002] With the rapid development of AI computing power, the power consumption of computing units has soared. Traditional thick copper core solutions can no longer meet the requirements for heat dissipation and current flow. New designs need to adopt buried copper block technology, which involves filling the copper blocks with resin and then pressing them into the PCB stack.

[0003] Currently, the industry standard is to first cut the copper blocks into small pieces and then fill them with resin. This method requires making a dedicated filling fixture for each small copper block, and then grinding each block individually after the resin filling and curing are completed. This method is costly and inefficient. In addition, the small copper blocks are difficult to clamp and experience uneven stress during grinding, making it difficult to guarantee the grinding quality. Furthermore, grinding each block individually is not suitable for mass production needs. Summary of the Invention

[0004] The purpose of this invention is to provide a method for resin plugging of copper blocks in power boards, which simplifies the process of resin plugging of copper blocks, reduces fixture costs, and improves processing efficiency and quality stability.

[0005] A method for resin plugging of copper blocks in a power supply board includes the following steps: S1. Provide a copper substrate; S2. Drill positioning holes and through holes on the copper substrate; S3. Resin plugging of the drilled copper substrate. S4. Cut the plugged and ground copper substrate into multiple finished copper blocks; S5. Place the finished copper block into the PCB lamination stack.

[0006] In the above technical solution, by first drilling and resin plugging the large copper block substrate, and then cutting and separating it to form finished copper blocks, the traditional method of making a separate fixture for each small copper block to plug the holes is avoided. This solves the problems of difficult operation, high fixture cost and low processing efficiency of plugging small copper blocks. At the same time, the large copper block substrate is easier to clamp and more uniformly stressed during grinding, which significantly improves the quality stability of resin plugging and overall production efficiency.

[0007] Furthermore, step S1 also includes laying out the layout on the copper block substrate, reserving a cutting gap between adjacent finished copper blocks, and setting a process edge on the outer periphery of the layout area of ​​the copper block substrate.

[0008] In the above technical solution, by pre-arranging the layout on the copper block substrate and reserving the cutting spacing, as well as setting the process edge, the structural strength and dimensional stability of the whole board can be maintained during subsequent drilling, hole plugging and grinding processes, ensuring the dimensional accuracy and quality of the finished copper block.

[0009] Furthermore, step S4 also includes cutting off the process edge.

[0010] In the above technical solution, the process edge cutting is integrated into the process of dividing the copper substrate into finished copper blocks. All cutting actions can be completed in one clamping, eliminating additional processing steps and ensuring that the finished copper blocks can be directly put into the subsequent pressing process. While ensuring a tight production cycle, it effectively avoids positioning errors that may occur due to multiple clamping.

[0011] Furthermore, in step S4, a milling cutter is used for cutting, the diameter of which is 2.0 mm and the cutting spacing is 0.2 mm.

[0012] In the above technical solution, by limiting the use of a milling cutter with a diameter of 2.0mm and reserving a cutting gap of 0.2mm, this specific combination of parameters can minimize material loss and control the burrs generated during cutting while ensuring cutting efficiency and tool life. This ensures the smoothness of the finished copper block edge and the consistency of dimensional tolerances, providing a reliable guarantee for subsequent precision lamination in PCB stacking.

[0013] Furthermore, step S2 also includes creating a foolproof hole, which is used to define the machining orientation.

[0014] In the above technical solution, anti-foolproof holes are made during drilling, and the structural features are used to forcibly limit the processing orientation, avoiding defects caused by incorrect placement of copper blocks, ensuring the processing accuracy on the fully automated production line, and reducing the risks brought about by manual identification and verification.

[0015] Furthermore, in step S2, the specific steps for drilling the through hole are as follows: Drill guide holes in the copper substrate; The guide hole is enlarged by milling along a circular trajectory using a milling cutter to form a through hole with the target diameter.

[0016] In the above technical solution, the through hole processing adopts a metal forming method of first drilling a guide hole and then milling and enlarging the hole. This avoids the wobble and vibration phenomenon caused by uneven force on the tool when directly drilling large holes, ensuring the relative positional accuracy between the through hole and the positioning hole. At the same time, the milling and enlarging process makes the hole wall quality better, providing a hole shape with accurate dimensions and smooth inner wall for subsequent resin plugging, and improving the fullness and bonding force of the plugging.

[0017] Furthermore, the diameter of the guide hole is 3.0 mm, the diameter of the milling cutter is 2.0 mm, the diameter of the circular trajectory is 6.0 mm, and the diameter of the through hole is 8.0 mm.

[0018] In the above technical solution, by specifically defining the dimensional parameters of the guide hole, the milling cutter diameter and the tool path, a through hole with a diameter of 8.0 mm can be precisely machined in one go. It can stably achieve high-precision hole enlargement on thick copper substrates and ensure the uniformity of hole quality.

[0019] Furthermore, step S3 also includes grinding the copper substrate after the resin filling is completed, so that the resin surface is flush with the surface of the copper substrate.

[0020] In the above technical solution, a grinding process is added after the resin plugging is completed, so that the surface of the cured resin is completely flush with the surface of the copper substrate. This eliminates stress concentration points and void defects caused by resin protrusions or depressions during subsequent pressing, ensuring tight bonding between power board stacks and excellent heat dissipation and conductivity.

[0021] Furthermore, the copper substrate has dimensions of 400mm × 600mm and a thickness of 3.0mm; the finished copper block has dimensions of 300mm × 30mm.

[0022] In the above technical solution, the enlarged processing scheme of large copper block layout design based on the size of finished copper blocks transforms the complex processing of multiple small-sized products into a single large-board process, making full use of the efficiency and operability of whole-board processing. After completing the plugging and grinding, it is then cut into the required finished products, solving the problems of low efficiency and difficulty in controlling precision when producing small copper blocks in batches.

[0023] Furthermore, in step S2, the positioning hole and through hole are drilled using a carbide tungsten carbide drill bit.

[0024] In the above technical solution, a cemented carbide tungsten carbide drill bit is used in the drilling of copper blocks. Its wear resistance and high-temperature hardness effectively resist the huge cutting force and heat generated during the processing of thick copper plates, reducing the occurrence of needle breakage and hole position displacement. Under long-term continuous processing operations, the consistency of the positioning hole and through hole diameter is guaranteed, thereby reducing the tool change frequency and increasing the production capacity.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: by first drilling and resin plugging the entire large copper block substrate, and then cutting and separating it to form finished copper blocks, the traditional method requires making a separate fixture for each small copper block to plug the holes, which solves the problems of difficult operation, high fixture cost and low processing efficiency of plugging small copper blocks. At the same time, the large copper block substrate is easier to clamp and more uniformly stressed during grinding, which significantly improves the quality stability of resin plugging and overall production efficiency. Attached Figure Description

[0026] Figure 1 This is a flowchart of a method for resin plugging of copper blocks in a power board according to an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0029] Please refer to Figure 1 In a preferred embodiment, the method for resin plugging of buried copper blocks in a power board according to the present invention includes the following steps: S1. Provide a copper substrate; S2. Drill positioning holes and through holes on the copper substrate; S3. Resin plugging of the drilled copper substrate. S4. Cut the plugged and ground copper substrate into multiple finished copper blocks; S5. Place the finished copper block into the PCB lamination stack.

[0030] As can be seen from the above technical solution, by first drilling and resin plugging the large copper block substrate, and then cutting and separating it into finished copper blocks, the traditional method of making a separate fixture for each small copper block to plug the holes is avoided. This solves the problems of difficult operation, high fixture cost and low processing efficiency of plugging small copper blocks. At the same time, the large copper block substrate is easier to clamp and more uniformly stressed during grinding, which significantly improves the quality stability of resin plugging and overall production efficiency.

[0031] In this embodiment, step S1 further includes laying out the copper block substrate, reserving a cutting gap between adjacent finished copper blocks, and setting a process edge on the outer periphery of the layout area of ​​the copper block substrate.

[0032] Specifically, first, the specifications of the finished copper block are confirmed. In this embodiment, the finished copper block is 300mm × 30mm in size and 3.0mm thick. Then, the copper block substrate is laid out, such as... Figure 1 As shown, the copper substrate size is 400mm × 600mm. One piece is arranged in the X direction, with a finished copper block size of 400mm. Fifteen pieces are arranged in the Y direction, each finished copper block being 30mm wide, with a total layout size of 450mm. A 2.2mm cutting gap is reserved between adjacent finished products, and the longitudinal layout size is 600mm. Additionally, a 5mm process edge is reserved around the layout area to ensure clamping stability during subsequent drilling, hole plugging, and grinding processes.

[0033] By pre-laying out the copper block substrate and reserving cutting gaps, as well as setting process edges, the structural strength and dimensional stability of the entire board can be maintained during subsequent drilling, hole plugging and grinding processes, ensuring the dimensional accuracy and quality of the finished copper block.

[0034] Step S4 also includes removing the process edge. Specifically, after cutting the copper substrate into multiple finished copper blocks, the pre-reserved 5mm process edge is milled away along the perimeter of the layout to ensure that the dimensions of all finished copper blocks fully meet the design requirements.

[0035] The process of cutting off the process edges is integrated into the process of dividing the copper substrate into finished copper blocks. All cutting actions can be completed in one clamping, eliminating additional processing steps and ensuring that the finished copper blocks can be directly put into the subsequent pressing process. While ensuring a tight production cycle, it effectively avoids positioning errors that may occur due to multiple clamping.

[0036] In step S4, a milling cutter with a diameter of 2.0 mm is used for cutting, and the cutting interval is 0.2 mm. Specifically, a 2.0 mm diameter milling cutter is selected for cutting, and the cutter moves along the slit line in the reserved cutting area between adjacent finished copper blocks. Since the reserved interval between adjacent finished copper blocks is 2.2 mm during layout, after cutting with a 2.0 mm milling cutter, a 0.1 mm allowance is left on each side, for a total cutting interval of 0.2 mm. The cutting sequence is to first mill the transverse slit line, then the longitudinal slit line, to avoid loose copper blocks causing vibration. The cutting method uses an oblique entry angle of 15° to avoid vertical cutting and reduce impact. When retracting the cutter, it is lifted 2 mm to avoid scratching the surface of the copper block.

[0037] By limiting the use of a 2.0mm diameter milling cutter and reserving a 0.2mm cutting gap, this specific combination of parameters can minimize material loss and control burrs generated during cutting while ensuring cutting efficiency and tool life. This ensures the smoothness of the finished copper block edges and the consistency of dimensional tolerances, providing a reliable guarantee for subsequent precision lamination in PCB stacking.

[0038] Step S2 also includes creating a foolproof hole, which is used to define the processing orientation. Specifically, when drilling the positioning holes, a total of three positioning holes are drilled, including two ordinary positioning holes and one foolproof hole. The position of the foolproof hole is asymmetrically arranged with the other two positioning holes, so that the copper substrate has only one correct placement orientation in subsequent processing.

[0039] During drilling, anti-foolproof holes are made simultaneously. The structural features are used to forcibly limit the processing orientation, avoiding defects caused by incorrect placement of copper blocks, ensuring the processing accuracy on the fully automated production line, and reducing the risks associated with manual identification and verification.

[0040] In step S2, the specific steps for drilling the through hole are as follows: drilling a guide hole on the copper substrate; milling the guide hole along a circular trajectory using a milling cutter to enlarge the hole, so as to form a through hole with the target diameter.

[0041] Specifically, six through holes need to be drilled in each finished copper block area. The drilling process begins with pre-drilling, using a 3.0mm diameter drill bit to create guide holes in the copper substrate. This provides positioning for the subsequent milling cutter, preventing deviation and vibration during milling. Then, the holes are enlarged using a 2.0mm diameter milling cutter. The cutter center is controlled to follow a circular path with a diameter of 6.0mm. After milling, an 8.0mm diameter through hole is formed.

[0042] The through-hole machining adopts a metal forming method of first drilling a guide hole and then milling and enlarging the hole. This avoids the wobble and vibration caused by uneven force on the tool when drilling large holes directly, ensuring the relative positional accuracy between the through hole and the positioning hole. At the same time, the milling and enlarging process improves the hole wall quality, providing a precise hole shape with a smooth inner wall for subsequent resin plugging, and improving the fullness and bonding force of the plugging.

[0043] Step S3 further includes grinding the copper substrate after resin plugging to make the resin surface flush with the surface of the copper substrate. Specifically, the resin plugging is performed using an aluminum sheet plugging process, fully filling all the through holes on the copper substrate with resin. After the resin has completely cured, the surface of the copper substrate is leveled using a grinding device until the resin-plugged surface is completely flush with the surface of the copper substrate, without any protrusions or depressions.

[0044] After the resin plugging is completed, a grinding process is added to make the surface of the cured resin completely flush with the surface of the copper substrate. This eliminates stress concentration points and void defects caused by resin protrusions or depressions during subsequent pressing, ensuring tight bonding between power board stacks and excellent heat dissipation and conductivity.

[0045] In step S2, the positioning hole and through hole are drilled using a carbide tungsten carbide drill bit. Using a carbide tungsten carbide drill bit in drilling copper blocks leverages its wear resistance and high-temperature hardness to effectively resist the enormous cutting forces and heat generated during the machining of thick copper plates, reducing needle breakage and hole misalignment. This ensures consistency in the diameter of the positioning hole and through hole during long-term continuous machining operations, thereby reducing tool change frequency and increasing productivity.

[0046] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for resin plug hole of a power board copper block, characterized in that, Includes the following steps: S1. Provide a copper substrate; S2. Drill positioning holes and through holes on the copper substrate; S3. Resin plugging of the drilled copper substrate. S4. Cut the plugged and ground copper substrate into multiple finished copper blocks; S5. Place the finished copper block into the PCB lamination stack.

2. The method of claim 1, wherein, Step S1 also includes laying out the layout on the copper block substrate, reserving a cutting gap between adjacent finished copper blocks, and setting a process edge on the outer periphery of the layout area of ​​the copper block substrate.

3. The method for resin plugging of embedded copper blocks in a power board according to claim 2, characterized in that, Step S4 also includes cutting off the process edge.

4. The method for resin plugging of embedded copper blocks in a power board according to claim 2, characterized in that, In step S4, a milling cutter with a diameter of 2.0 mm is used for cutting, and the cutting spacing is 0.2 mm.

5. The method of claim 1, wherein the method further comprises: Step S2 also includes creating a foolproof hole, which is used to define the machining orientation.

6. The method of claim 1, wherein, In step S2, the specific steps for drilling the through hole are as follows: Drill guide holes in the copper substrate; The guide hole is enlarged by milling along a circular trajectory using a milling cutter to form a through hole with the target diameter.

7. The method for resin plugging of embedded copper blocks in a power board according to claim 6, characterized in that, The diameter of the guide hole is 3.0 mm, the diameter of the milling cutter is 2.0 mm, the diameter of the circular trajectory is 6.0 mm, and the diameter of the through hole is 8.0 mm.

8. The method of claim 1, wherein the method further comprises: Step S3 also includes grinding the copper substrate after the resin filling is completed, so that the resin surface is flush with the surface of the copper substrate.

9. The method of claim 1, wherein the method further comprises: The copper substrate has a size of 400mm × 600mm and a thickness of 3.0mm; the finished copper block has a size of 300mm × 30mm.

10. The method of claim 1, wherein the method further comprises: In step S2, the positioning hole and through hole are drilled using a carbide tungsten carbide drill bit.

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