A method for manufacturing a multi-layer thermoelectric separation copper-embedded plate

Abstract

The application discloses a kind of multilayer thermoelectric separation buried copper plate manufacturing method including preparation inner layer core plate, slot and bury copper block, rough drilling through hole, filling resin, making secondary outer layer pattern, preparation outer layer core plate, drill conductive hole and heat dissipation hole and the like steps, copper block is divided into heat dissipation area and conductive area, and heat is separated by independent through hole and blind hole design, copper block can increase the component needed to be conducted on the surface simultaneously with the component needed to be heat-conducted, simultaneously realize heat efficient conduction and signal stable transmission, do not interfere with each other;This partition design makes copper block not only be used for heat dissipation, but also be used for conduction, improve copper block utilization, reduce PCB design area, to meet the development needs of high-density, miniaturization electronic equipment.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board manufacturing technology, specifically a method for manufacturing a multilayer thermoelectrically separated embedded copper plate. Background Technology

[0002] With the rapid development of technologies such as 5G communication, artificial intelligence, new energy vehicles, LED lighting, and wearable devices, electronic devices are rapidly evolving towards high integration and miniaturization. These devices require printed circuit boards (PCBs) to accommodate more components within a limited space, while simultaneously meeting the dual requirements of high-speed signal transmission and efficient heat dissipation. In traditional PCB design, heat dissipation modules and conductive lines are often laid out independently. Embedded copper blocks typically serve only as a single-function carrier. When used solely for heat dissipation, the copper blocks cannot simultaneously meet conductivity requirements, necessitating additional conductive lines and increasing PCB layer count and complexity. When used solely for conductivity, heat dissipation capacity is insufficient, especially for power devices (such as power modules and RF chips), where heat accumulation can easily lead to localized overheating, affecting signal stability. Furthermore, the lack of effective separation of thermoelectric paths in traditional designs can cause thermoelectric coupling interference, such as temperature changes affecting conductivity or current loss exacerbating heat generation. It is difficult to achieve coordinated optimization of heat dissipation and conductivity in high-density scenarios. This separation of heat dissipation and conductivity design often results in low copper resource utilization and redundant PCB area, making it difficult to adapt to the development trend of miniaturization and multi-functionality. Summary of the Invention

[0003] To address the aforementioned technical challenges, this invention provides a method for manufacturing a multilayer thermoelectric separation embedded copper plate, comprising the following steps:

[0004] Preparation of inner core board: Cut the insulating substrate into the target size according to the design requirements, and cover the surface of the insulating substrate with the first copper foil to obtain the copper-clad board. Then, set the cursor points at the router position of the copper-clad board, and use a laser to drill anti-fool holes to obtain the inner core board.

[0005] Grooving and embedding copper blocks: According to the size of the copper blocks, grooves are cut at the specified positions of the inner core board. The groove depth is slightly greater than the thickness of the copper blocks. After embedding the copper blocks in the grooves, the first semi-cured sheet is applied, with the edges aligned with the cursor points. The layers are then pressed together in one go to form the second outer core board.

[0006] Rough drilling through hole: Drill an initial through hole in the copper block with a pre-larged diameter, the initial through hole penetrating the copper block;

[0007] Resin filling: Inject the resin into the pre-enlarged initial through-hole and heat to cure;

[0008] Fabrication of the secondary outer layer pattern: A dry film is coated on the surface of the secondary outer layer core board, and after exposure and development, the first copper foil is etched to form the secondary outer layer conductive line. The distance between the secondary outer layer conductive line and the edge of the copper block is ≥0.5mm.

[0009] Preparation of outer core board: A second prepreg and a second copper foil are laminated onto the surface of the outer core board, the edges are aligned with the cursor points, and the outer core board is obtained by a second lamination.

[0010] Drilling conductive and heat dissipation holes: Drill blind holes on one side of the outer core board, with the depth controlled to penetrate to the surface of the copper block to form heat conduction holes. At the same time, drill conductive holes in the resin-filled area, fill the heat conduction holes with copper material, plate the inner wall of the conductive holes with copper, and then brown or gold plate the surface of the outer core board to obtain the finished product.

[0011] Preferably, the initial through-hole diameter is 0.2~0.3mm.

[0012] Preferably, the pre-larged aperture is 0.3~0.7mm.

[0013] Preferably, the resin is polypropylene resin or epoxy resin.

[0014] Preferably, the diameter of the conductive hole is 0.1~0.2mm.

[0015] Preferably, the diameter of the blind hole is 0.5~1mm.

[0016] Preferably, the heating curing method involves raising the temperature to 150-160℃ at a rate of 2-4℃ / min and holding it at that temperature for 40-60 minutes.

[0017] Preferably, the insulating substrate is prepared using an epoxy glass fiber cloth substrate FR-4 or a composite epoxy resin glass fiber cloth substrate CEM-3.

[0018] Preferably, the pressure during both the first and second pressing is 7~9 tons / m³. 2 The temperature was 130~170℃ and the duration was 30~60min.

[0019] Preferably, the thickness of the first copper foil and the second copper foil is 18~35μm.

[0020] The beneficial effects of this application are as follows: the copper block is divided into heat dissipation area and conductive area, and thermal and electrical separation is achieved through independent through-hole and blind hole design. Components that need to conduct electricity can be added to the copper block at the same time as components that need to conduct heat, achieving efficient heat conduction and stable signal transmission without interference. This partitioned design allows the copper block to be used not only for heat dissipation but also for conduction, improving the utilization rate of the copper block and reducing the PCB design area to meet the development needs of high-density and miniaturized electronic devices. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 A schematic diagram of a multi-layer thermoelectric separation embedded copper plate structure;

[0023] In the picture:

[0024] 1. Inner core board;

[0025] 2. Copper block;

[0026] 3. Initial through hole; 31. Conductive hole;

[0027] 4. Heat conduction holes. Detailed Implementation

[0028] The following drawings disclose several embodiments of the present invention. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not essential. Furthermore, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.

[0029] Furthermore, in this invention, the use of terms such as "first," "second," etc., is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0030] The present invention will now be described in further detail with reference to specific embodiments, so that those skilled in the art can more clearly understand the present invention.

[0031] The following embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. All other embodiments obtained by those skilled in the art based on the specific embodiments of the invention without inventive effort are within the protection scope of the invention.

[0032] In the embodiments of the present invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art; in the embodiments of the present invention, unless specifically specified, the technical means used are conventional means well known to those skilled in the art.

[0033] Raw material source:

[0034] Epoxy fiberglass cloth substrate FR-4, purchased from Dongguan Xingteng Plastic Products Co., Ltd.;

[0035] The CEM-3 composite epoxy resin fiberglass cloth substrate was purchased from Shanghai Weifen Industrial Co., Ltd.

[0036] Two-component epoxy adhesive AB glue, Jiudian brand JD-8112, purchased from Hangoda Trading (Shenzhen) Co., Ltd.

[0037] Polyurethane adhesive, Lankel Road L-8460, purchased from Guangdong Canqi New Materials Co., Ltd.

[0038] Acrylic adhesive, Humiseal UV40, purchased from Shenzhen Shiyun Materials Co., Ltd.

[0039] Polypropylene resin, S2040, purchased from Shanghai Qiaowei Chemical Technology Co., Ltd.

[0040] Epoxy resin, ER2188, purchased from Dongguan Bei-Electronic Materials Co., Ltd.

[0041] All other reagents were commercially available.

[0042] Example

[0043] Please see Figure 1 , Figure 1 This is a schematic diagram of a multi-layer thermoelectric separation embedded copper plate structure. This embodiment provides a multi-layer thermoelectric separation embedded copper plate, including an inner core plate with an installation groove, a copper block embedded in the installation groove, an initial through hole in the conductive area of ​​the copper block, resin injected into the initial through hole, a through conductive hole in the resin, and a heat-conducting hole in the heat dissipation area of ​​the copper block, which is filled with copper material.

[0044] The above-mentioned method for manufacturing multilayer thermoelectric separation embedded copper plates includes the following steps:

[0045] Fabrication of the inner core board: An insulating substrate with a thickness of 2-3 mm is cut to the target size according to design requirements, and a first copper foil with a thickness of 18-35 μm is laminated on the surface of the insulating substrate to obtain a copper-clad laminate. Then, cursor points are set at the milling positions of the copper-clad laminate, and anti-fool holes are drilled using a laser. After deburring, degreasing, electroplating, and etching, the inner core board is obtained. The insulating substrate is made of epoxy fiberglass cloth substrate FR-4 or composite epoxy resin fiberglass cloth substrate CEM-3. The laser drilling of anti-fool holes and the setting of cursor points can achieve high-precision alignment, ensuring the accuracy of the copper block embedding position and the hole positions of conductive and heat-conducting holes, and avoiding the failure of the thermoelectric channel due to misalignment.

[0046] Grooving and embedding copper blocks: Based on the size of the copper blocks, grooves are cut at designated positions on the inner core board using a CNC milling machine or laser cutting. The groove depth is slightly greater than the thickness of the copper blocks. In this embodiment, the groove depth is 1.3~1.5mm, the copper block thickness is 0.8~1.1mm, and the epoxy adhesive coating thickness is 10~15μm. After embedding the copper blocks in the grooves, the first prepreg is applied, with the edges aligned with the marked points. The boards are then pressed together in one operation at a pressure of 7~9 tons / m². 2 The temperature is 130~170℃, and the duration is 30~60min, forming the outermost core board. The epoxy adhesive can be any of two-component epoxy adhesive, polyurethane adhesive, or acrylic adhesive. The epoxy adhesive can firmly bond the copper block in the groove. By slotting and embedding the copper block at the designated position of the inner core board, the high thermal conductivity of copper can quickly conduct the heat generated by the electronic components during operation to the copper block, and then the copper block diffuses the heat to the entire board, thereby achieving efficient heat conduction and reducing the temperature of the electronic components.

[0047] Rough drilling through hole: Use a CNC drilling machine to drill an initial through hole and pre-enlarge the hole diameter on the copper block. The initial through hole diameter is 0.2~0.3mm, and the pre-enlarged hole diameter is 0.3~0.7mm. The initial through hole penetrates the copper block.

[0048] Resin filling: Use a pressure pump to inject resin into the pre-enlarged initial through-holes, and heat to 150-160℃ at a heating rate of 2-4℃ / min, and hold for 40-60 minutes for curing; either polypropylene resin or epoxy resin can be used; after filling with resin, an insulating support is formed to prevent the copper block from conducting electricity directly, providing conditions for the functional separation of the subsequent conductive holes and heat-conducting holes, while making the heat conduction path clearer and more efficient, preventing the disorderly diffusion of heat through the conductive path, and further improving the heat conduction efficiency;

[0049] Fabrication of the secondary outer layer pattern: A dry film is coated on the surface of the secondary outer layer core board. After exposure and development, the first copper foil is etched to form the secondary outer layer conductive circuit. The distance between the secondary outer layer conductive circuit and the edge of the copper block is ≥0.5mm to avoid the etching solution from eroding the edge of the copper block, ensuring the integrity and stability of the secondary outer layer conductive circuit, providing a reliable path for signal transmission, and preventing short circuits.

[0050] Preparation of the outer core board: A second prepreg and a second copper foil with a thickness of 18~35μm are laminated onto the surface of the outer core board, with the edges aligned with the marked points, and then laminated again at a pressure of 7~9 tons / m. 2 The temperature is 130~170℃ and the duration is 30~60min to obtain the outer core board; a two-stage pressing process is used to ensure a tight bond between the copper block and the insulating substrate and prepreg, reducing interlayer gaps and contact resistance while reducing thermal interface resistance.

[0051] Drilling conductive and heat dissipation holes: Using a laser drill or a depth-controlled drill, blind holes with a diameter of 0.5~1mm are drilled on one side of the outer core board, with the depth controlled to penetrate to the surface of the copper block to form heat-conducting holes. At the same time, CNC drilling machines are used to drill conductive holes with a diameter of 0.1~0.2mm in the resin-filled area, and copper material is filled into the heat-conducting holes. The resin-filled layer forms a thermal insulation barrier, avoiding lateral thermal crosstalk and blocking direct conduction between the copper block and the conductive holes. The copper filling of the heat-conducting holes realizes a dot matrix heat dissipation structure, providing a direct and efficient heat conduction channel, allowing heat to be transferred more quickly from the heat-generating element to the copper block, and then diffused out through the copper block, effectively reducing thermal resistance, improving heat dissipation efficiency, and enhancing thermal conductivity. Copper plating is applied to the inner wall of the conductive holes to achieve electrical connection, and then browning or gold plating is applied to the surface of the outer core board to obtain the finished product. The distribution density of conductive holes and heat-conducting holes can be designed independently, allowing for more flexible wiring.

[0052] The above are merely embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for manufacturing a multilayer thermoelectric separation embedded copper plate, characterized in that, Includes the following steps: Preparation of inner core board: Cut the insulating substrate into the target size according to the design requirements, and cover the surface of the insulating substrate with the first copper foil to obtain the copper-clad board. Then, set the cursor point at the router position of the copper-clad board, and use a laser to drill anti-fool holes to obtain the inner core board. Grooving and embedding copper blocks: According to the size of the copper blocks, grooves are cut at the designated positions on the inner core board. The groove depth is slightly greater than the thickness of the copper blocks. After embedding the copper blocks in the grooves, the first prepreg is applied, with the edges aligned with the cursor points. The boards are then pressed together in one go to form the outer core board. Rough drilling through hole: Drill an initial through hole in the copper block with a pre-larged diameter, the initial through hole penetrating the copper block; Resin filling: Inject the resin into the pre-enlarged initial through-hole and heat to cure; Fabrication of the secondary outer layer pattern: A dry film is coated on the surface of the secondary outer layer core board, and after exposure and development, the first copper foil is etched to form the secondary outer layer conductive line. The distance between the secondary outer layer conductive line and the edge of the copper block is ≥0.5mm. Preparation of outer core board: A second prepreg and a second copper foil are attached to the surface of the outer core board, the edges are aligned with the cursor points, and the outer core board is obtained by a second pressing. Drilling conductive and heat dissipation holes: Drill blind holes on one side of the outer core board, with the depth controlled to penetrate to the surface of the copper block to form heat conduction holes. At the same time, drill conductive holes in the resin-filled area, fill the heat conduction holes with copper material, plate the inner wall of the conductive holes with copper, and then brown or gold plate the surface of the outer core board to obtain the finished product.

2. The method for manufacturing a multilayer thermoelectric separation embedded copper plate according to claim 1, characterized in that, The initial through-hole diameter is 0.2~0.3mm.

3. The method for manufacturing a multilayer thermoelectric separation embedded copper plate according to claim 1, characterized in that, The pre-enlarged aperture is 0.3~0.7mm.

4. The method for manufacturing a multilayer thermoelectric separation embedded copper plate according to claim 1, characterized in that, The resin is either polypropylene resin or epoxy resin.

5. The method for manufacturing a multilayer thermoelectric separation embedded copper plate according to claim 1, characterized in that, The diameter of the conductive hole is 0.1~0.2mm.

6. The method for manufacturing a multilayer thermoelectric separation embedded copper plate according to claim 1, characterized in that, The diameter of the blind hole is 0.5~1mm.

7. The method for manufacturing a multilayer thermoelectric separation embedded copper plate according to claim 1, characterized in that, The heating and curing process involves raising the temperature to 150-160℃ at a rate of 2-4℃ / min and holding it at that temperature for 40-60 minutes.

8. The method for manufacturing a multilayer thermoelectric separation embedded copper plate according to claim 1, characterized in that, The insulating substrate is prepared using an epoxy glass fiber cloth substrate FR-4 or a composite epoxy resin glass fiber cloth substrate CEM-3.

9. The method for manufacturing a multilayer thermoelectric separation embedded copper plate according to claim 1, characterized in that, The pressure during both the primary and secondary pressing processes is 7~9 tons / m³. 2 The temperature was 130~170℃ and the duration was 30~60min.

10. The method for manufacturing a multilayer thermoelectric separation embedded copper plate according to claim 1, characterized in that, The thickness of the first copper foil and the second copper foil is 18~35μm.

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