Processing method of copper paste sintered buried copper block printed circuit board and its PCB bonding board

Abstract

The present invention provides a processing method for a copper paste sintered buried copper block printed circuit board and its PCB bonding board, comprising the following steps: S1. Upper layer material preparation, drilling buried copper holes corresponding to the buried copper blocks on the front plug-in layer board CS and the inner layer boards corresponding to each layer of the upper layer respectively; S2. Upper layer prepreg treatment, milling holes corresponding to the buried copper blocks on all upper layer prepregs; S3. Upper layer lamination to form an upper layer laminate; S4. Lower layer material preparation, S5. Lower layer prepreg treatment, S6. Lower layer lamination to form a lower layer laminate; S7. Intermediate prepreg material preparation: Stack intermediate prepregs corresponding between the upper layer laminate and the lower layer laminate, and drill a plurality of holes for plugging copper paste for sintering processing in the intermediate prepreg area corresponding to the bottom side of the buried copper block; S8. Upper and lower layer lamination to form a multilayer circuit board; the buried copper blocks achieve interconnection and conduction between any inner layers through sintering of the copper paste in the holes.

Description

Technical Field

[0001] The present invention relates to PCB board processing technology, in particular to a processing method for a copper paste sintered buried copper block printed circuit board and its PCB combined board. Background Art

[0002] With the rapid development of electronic technology, electronic products are developing towards being thinner, lighter, shorter and smaller, and the application and popularization of high-power electronic components have resulted in an increasingly smaller effective heat dissipation area for electronic products, while the heat dissipation demand is increasing. Moreover, the performance requirements of electronic products for printed circuit boards are getting higher and higher. Therefore, how to seek the best method for heat dissipation and structural design has become a major challenge in current electronic design.

[0003] Common heat dissipation designs for PCB circuit boards generally include high-density heat dissipation holes, metal-based circuit boards or soldering metal substrates on the surface of the circuit board. However, the heat dissipation effect of high-density heat dissipation holes is limited, and it also wastes drilling space; while the designs of metal-based circuit boards or soldering metal substrates on the surface of the circuit board have disadvantages such as large consumption of metal materials, bulky volume, limited structural design, and high cost.

[0004] The heat dissipation methods of traditional printed circuit boards have been difficult to meet the requirements of modern electronic products. With the rapid development of new-generation information technology, energy-saving and new energy vehicles, power equipment, aerospace and other fields, the solution of the heat dissipation problem has become extremely urgent. Against this background, buried copper block PCBs have emerged as the times require. The so-called buried copper block means that copper blocks are buried or embedded locally in the PCB, and heat-generating electronic components are directly installed on the copper blocks, and the heat is quickly dissipated by using the high thermal conductivity of the copper blocks. The buried copper block PCB board has high thermal conductivity and high heat dissipation performance, and can effectively solve the heat dissipation problem of high-power electronic components in special application fields. The buried copper block PCB board not only has good heat dissipation effect, but also can save board surface space, and has been increasingly applied to 5G communication equipment in recent years, with broad application prospects.

[0005] As a new type of printed circuit board, the copper paste sintered buried copper block and inner layer interconnected printed circuit board has the following advantages: a. High reliability. By sintering copper paste to bury copper blocks in the inner layer of the printed board, good electrical connection and mechanical connection can be achieved, improving the reliability of the printed circuit board; b. High-density wiring. More wiring can be realized in a limited space, improving the integration of the printed circuit board; c. Good heat dissipation performance. The copper block has good thermal conductivity and can effectively dissipate the heat generated by electronic components, improving the stability and reliability of electronic products.

[0006] However, there are still some problems with the current processing methods for copper paste sintered buried copper blocks and inner layer interconnected printed circuit boards, mainly including the following aspects: a. The processing technology is complex. The processing technology for copper paste sintered buried copper block inner layer interconnected printed circuit boards is relatively complex and requires multiple steps to complete, including the preparation of copper blocks, the preparation of copper paste, the printing of copper paste, the sintering of copper paste, etc.; b. High processing accuracy requirements. Due to the relatively complex structure of copper paste sintered buried copper block inner layer interconnected printed circuit boards, the requirements for processing accuracy are also relatively high, and high-precision processing equipment and technology are required to ensure the processing quality; c. High cost. The processing cost of copper paste sintered buried copper block inner layer interconnected printed circuit boards is relatively high, mainly due to the complex processing technology, high processing accuracy requirements, and the need to use some special materials and equipment, etc.

[0007] In summary, there are still some problems with the current processing methods for copper paste sintered buried copper block inner layer interconnected printed circuit boards, and further research and improvement are needed to improve processing efficiency, reduce processing costs, and improve processing quality. Summary of the Invention

[0008] The embodiments of the present invention provide a processing method for a copper paste sintered buried copper block printed circuit board and its PCB bonding board, which realizes the interconnection of buried copper blocks and inner layer circuits. The printed circuit board passes through semi-buried copper blocks, drills holes at the positions of the buried copper blocks and inserts copper paste, and realizes the interconnection of the copper paste and the inner layer core board circuit layer. Through the optimization of design and process, the problem of the interconnection of buried copper blocks and any layer of the inner layer pattern is solved, and the processing efficiency and processing quality are effectively improved through process improvement, while reducing the processing cost.

[0009] The technical solution adopted by the present invention to solve its technical problems is:

[0010] The technical solution adopted by at least one embodiment of the present invention is as follows:

[0011] In a first aspect, the present invention provides a processing method for a copper paste sintered buried copper block printed circuit board, and the processing method includes the following steps:

[0012] S1. Preparation of upper layer materials:

[0013] Prepare the front plug-in layer board CS, the inner layer boards corresponding to each layer of the upper layer, and the buried copper blocks required for burying copper. Perform milling hole processing on the front plug-in layer board CS and the inner layer boards corresponding to each layer of the upper layer respectively, and also wash and drill the buried copper holes corresponding to the buried copper blocks.

[0014] S2. Treatment of upper layer prepregs: When milling holes on all upper layer prepregs, wash and drill the buried copper holes corresponding to the buried copper blocks respectively.

[0015] S3. Upper layer lamination: Align the slot holes on the front plug-in layer board CS, the inner layer boards corresponding to each layer of the upper layer, and all the upper layer prepregs, embed buried copper blocks in the slot holes, and then laminate to form the upper layer laminate;

[0016] S4. Lower layer material preparation: Prepare the back welding layer board SS and the inner layer boards corresponding to each layer of the lower layer, and perform punching processing;

[0017] S5. Lower layer prepreg treatment;

[0018] S6. Lower layer lamination: Align the slots or holes on the back welding layer board SS, the inner layer boards corresponding to each layer of the lower layer, and all the lower layer prepregs, and laminate to form the lower layer laminate;

[0019] S7. Intermediate prepreg material preparation between the upper and lower layers: Intermediate prepregs are stacked corresponding to the upper layer laminate and the lower layer laminate, and multiple drilling holes for plugging buried copper paste for sintering processing are drilled in the area of the intermediate prepreg corresponding to the bottom side of the buried copper block;

[0020] S8. Upper and lower layer lamination: Stack the upper layer laminate, the intermediate prepreg, and the lower layer laminate in sequence, and finally obtain a complete PCB board through lamination; The buried copper blocks are conductively connected to the inner layer through sintering of the copper paste in the drilling holes, and the buried copper blocks are interconnected with any layer of the inner layer by sintering connection with the copper paste.

[0021] Further, step S1 specifically further includes: performing blanking → inner light imaging → inner layer etching inspection → punching → milling → matching center → brownification processing on the front plug-in layer board CS and the inner layer boards corresponding to each layer of the upper layer respectively.

[0022] Further, step S2 specifically further includes: performing blanking → milling → auxiliary material matching processing on all the upper layer prepregs corresponding to the upper layer in sequence.

[0023] Further, step S3 specifically further includes: aligning the slot holes on the front plug-in layer board CS, the inner layer boards corresponding to each layer of the upper layer, and all the upper layer prepregs, embedding buried copper blocks in the slot holes, and then performing lamination → copper reduction → drilling → copper deposition / plating → resin plugging → post-soldermask baking → ceramic grinding → tool matching → inner light imaging → inner layer etching inspection → punching → matching center → brownification processing in sequence to form the upper layer laminate.

[0024] Further, step S4 specifically further includes: performing blanking → inner light imaging → inner layer etching inspection → punching → matching center → brownification processing on the back welding layer board SS and the inner layer boards corresponding to each layer of the lower layer respectively.

[0025] Further, step S6 specifically further includes: aligning the slots or holes on the back soldering layer board SS, the inner layer boards corresponding to each layer of the lower layer, and all the lower layer prepregs, and then successively performing lamination → copper reduction → drilling → copper deposition / plating → resin plugging → post-soldermask baking → ceramic grinding → tool matching → inner light imaging → inner layer etching inspection → punching → matching center → brownification processing to form the lower layer laminate.

[0026] Further, step S8 specifically further includes: successively stacking the upper layer laminate, the intermediate prepreg, and the lower layer laminate, and then performing lamination → drilling → copper deposition / plating → resin plugging → post-soldermask baking → ceramic grinding → copper reduction → drilling → copper deposition / plating → and finally obtaining the complete PCB according to the normal process.

[0027] Further, in steps S1, S2, and S3, it specifically further includes:

[0028] S1. Preparation of upper layer materials:

[0029] Prepare the front plug-in layer board CS, the first inner layer board L1, the second inner layer board L2, the third inner layer board L3, and the buried copper blocks required for buried copper;

[0030] Perform blanking → inner light imaging → inner layer etching inspection → punching → milling → matching center → brownification processing on the front plug-in layer board CS, the first inner layer board L1, the second inner layer board L2, and the third inner layer board L3 respectively;

[0031] Among them, in the milling process, milling the buried copper holes corresponding to the buried copper blocks on the front plug-in layer board CS, the first inner layer board L1, the second inner layer board L2, and the third inner layer board L3 respectively;

[0032] S2. Treatment of upper layer prepregs:

[0033] Perform blanking → milling → auxiliary material matching processing on the upper layer prepreg PP1 stacked correspondingly on the upper layer in sequence;

[0034] When milling holes on the upper layer prepreg PP1, milling the buried copper holes corresponding to the buried copper blocks respectively;

[0035] S3. Upper layer lamination:

[0036] Align the slot holes on the front plug-in layer board CS, the first inner layer board L1, the second inner layer board L2, the third inner layer board L3, and the upper layer prepreg PP1, embed the buried copper blocks in the slot holes, and then successively perform lamination → copper reduction → drilling → copper deposition / plating → resin plugging → post-soldermask baking → ceramic grinding → tool matching → inner light imaging → inner layer etching inspection → punching → matching center → brownification processing to form the upper layer laminate.

[0037] Further, in steps S4, S5, S6, and S7, it specifically further includes:

[0038] S4. Lower layer material preparation:

[0039] Prepare the back - welding layer board SS, the fourth inner layer board L4, the fifth inner layer board L5, and the sixth inner layer board L6;

[0040] Respectively perform blanking → inner - light imaging → inner - layer etching inspection → punching → matching center → brownification processing on the back - welding layer board SS, the fourth inner layer board L4, the fifth inner layer board L5, and the sixth inner layer board L6;

[0041] S5. Lower layer prepreg treatment:

[0042] Stack the corresponding lower - layer prepreg PP3 and perform blanking → auxiliary material matching processing in sequence;

[0043] S6. Lower layer lamination:

[0044] Align the holes on the back - welding layer board SS, the fourth inner layer board L4, the fifth inner layer board L5, the sixth inner layer board L6, and the lower - layer prepreg PP3, and perform lamination → copper reduction → drilling → copper deposition / plating on the board → resin plugging of holes → post - solder baking → ceramic grinding of the board → tool matching → inner - light imaging → inner - layer etching inspection → punching → matching center → brownification processing in sequence to form the lower - layer laminated part;

[0045] S7. Intermediate prepreg material preparation between the upper and lower layers:

[0046] There is an intermediate prepreg PP2 for bonding between the upper and lower layers, which is stacked corresponding to the upper - layer laminated part and the lower - layer laminated part. A plurality of uniformly distributed drill holes for plugging buried copper paste for sintering processing are drilled in the area of the intermediate prepreg PP2 corresponding to the bottom side of the buried copper block;

[0047] The intermediate prepreg PP2 is subjected to blanking → taping → drilling → copper paste plugging of holes → auxiliary material matching processing in sequence.

[0048] Furthermore, the number of layers of the printed circuit board is 4 - 20 layers.

[0049] In the second aspect, the present invention provides a PCB bonding board, which is made by using the processing method of the copper - paste - sintered buried copper - block printed circuit board described above.

[0050] The beneficial effects of the present invention are:

[0051] In the present invention, the buried copper blocks of the circuit board are processed by a three-time pressing method. First, the upper-layer materials are prepared. On the front plug-in layer board CS and the inner layer boards corresponding to each layer of the upper layer, buried copper holes corresponding to the buried copper blocks are respectively drilled; and the upper-layer prepregs are processed. On all the upper-layer prepregs, holes corresponding to the buried copper blocks are milled. Then, the upper layer is pressed to form an upper-layer pressed part. Then, the lower-layer materials are prepared, the lower-layer prepregs are processed, and then the lower layer is pressed to form a lower-layer pressed part; and the intermediate prepreg materials are prepared. Intermediate prepregs are stacked corresponding to the upper-layer pressed part and the lower-layer pressed part. A plurality of drilling holes for plugging buried copper paste for sintering processing are drilled in the intermediate prepreg area corresponding to the bottom side of the buried copper block. Finally, the upper and lower layers are pressed to form a multilayer circuit board, and the buried copper blocks are interconnected and conducted to any inner layer through sintering of the copper paste in the drilling holes.

[0052] The overall processing method is simple to operate, realizes the interconnection of the buried copper block board with any layer of the inner-layer pattern. The flatness of the buried copper block board is ensured by semi-burying the copper block, and the buried copper block is conducted with the inner-layer pattern through copper paste sintering, which can achieve good electrical connection and mechanical connection, and improve the reliability of the printed circuit board. More wirings can be realized in a limited space, improving the integration of the printed circuit board. Moreover, the buried copper block has good heat conduction performance, which can effectively dissipate the heat generated by electronic components, improving the stability and reliability of electronic products.

[0053] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. Description of the Drawings

[0054] Figure 1 It is a schematic enlarged structure diagram of the board body for buried copper processing of the six-layer circuit board corresponding to the present invention;

[0055] Figure 2 It is an electron microscopic enlarged schematic diagram of the partial cross-sectional structure of the buried copper block corresponding to the inner-layer interconnection during copper paste sintering in the buried copper block printed circuit board of the present invention. Specific Embodiments

[0056] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0057] In the description of the present invention, "several" means one or more, "multiple" means two or more, and understandings such as "greater than", "less than", "exceeding", etc. do not include the base number, while understandings such as "above", "below", "within", etc. include the base number. When terms such as "center", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings, and it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present invention.

[0058] In addition, if descriptions such as "first", "second", etc. are used only for the purpose of distinguishing technical features, they cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0059] In addition, in the description of the present invention, unless otherwise clearly defined, terms such as "set", "install", "connect", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be reasonably determined in combination with the specific content of the technical solution.

[0060] A processing method for a copper paste sintered buried copper block printed circuit board, as Figure 1 and Figure 2 shown, the processing method for the copper paste sintered buried copper block printed circuit board includes the following steps:

[0061] S1. Preparation of upper-layer materials:

[0062] Prepare the front plug-in layer board CS, the first inner layer board L1, the second inner layer board L2, the third inner layer board L3, and the buried copper blocks M required for buried copper;

[0063] Respectively perform blanking → inner light imaging → inner layer etching inspection → punching → milling → matching center → brownification processing on the front plug-in layer board CS, the first inner layer board L1, the second inner layer board L2, and the third inner layer board L3;

[0064] Among them, in the milling process, milling holes corresponding to the buried copper blocks are also respectively milled on the front plug-in layer board CS, the first inner layer board L1, the second inner layer board L2, and the third inner layer board L3;

[0065] S2. Treatment of upper-layer prepregs:

[0066] The upper corresponding prepreg PP1 is successively subjected to blanking → milling holes → auxiliary material matching processing;

[0067] When milling holes on the upper prepreg PP1, the buried copper holes corresponding to the buried copper blocks are respectively milled;

[0068] S3. Upper layer lamination:

[0069] Align the slot holes on the front plug-in layer board CS, the first inner layer board L1, the second inner layer board L2, the third inner layer board L3 and the upper prepreg PP1, embed the buried copper blocks M in the slot holes, and then successively perform lamination → copper reduction → drilling → copper deposition / plating → resin plugging → post-soldermask baking → ceramic grinding → tool matching → inner light imaging → inner layer etching inspection → punching → matching center → brownification processing to form the upper layer laminate;

[0070] S4. Lower layer material preparation:

[0071] Prepare the back welding layer board SS, the fourth inner layer board L4, the fifth inner layer board L5 and the sixth inner layer board L6;

[0072] The back welding layer board SS, the fourth inner layer board L4, the fifth inner layer board L5 and the sixth inner layer board L6 are respectively subjected to blanking → inner light imaging → inner layer etching inspection → punching → matching center → brownification processing;

[0073] S5. Lower layer prepreg treatment:

[0074] The lower corresponding prepreg PP3 is successively subjected to blanking → auxiliary material matching processing;

[0075] S6. Lower layer lamination:

[0076] Align the holes on the back welding layer board SS, the fourth inner layer board L4, the fifth inner layer board L5, the sixth inner layer board L6 and the lower prepreg PP3, and successively perform lamination → copper reduction → drilling → copper deposition / plating → resin plugging → post-soldermask baking → ceramic grinding → tool matching → inner light imaging → inner layer etching inspection → punching → matching center → brownification processing to form the lower layer laminate;

[0077] S7. Intermediate prepreg material preparation between the upper and lower layers:

[0078] A middle prepreg PP2 for bonding between the upper and lower layers is superimposed between the upper layer laminate and the lower layer laminate. A plurality of uniformly distributed drilling holes Z for plugging and sintering buried copper paste are drilled in the area of the middle prepreg PP2 corresponding to the bottom side of the buried copper block M;

[0079] The middle prepreg PP2 is successively subjected to blanking → taping → drilling → copper paste plugging → auxiliary material matching processing;

[0080] S8. Upper and lower layer lamination:

[0081] Stack the upper lamination component, the intermediate prepreg, and the lower lamination component in sequence. Through lamination → drilling → electroless copper plating / plating on the board → resin plugging of holes → post-baking of solder mask → ceramic grinding of the board → copper reduction → drilling → electroless copper plating / plating on the board → and then follow the normal process to finally obtain a complete PCB. A multi-layer circuit board is formed through lamination;

[0082] In this embodiment, through three lamination methods, the buried copper blocks of the circuit board are processed. Copper paste is stuffed into the holes drilled in the intermediate prepreg, and the buried copper blocks are conductively connected to the inner layer through sintering of the copper paste in the holes. The overall processing method is simple to operate, realizing the interconnection of any layer between the buried copper block board and the inner layer pattern. The flatness of the buried copper block board is ensured by semi-burying the copper blocks, and the buried copper blocks are conductively connected to the inner layer pattern through copper paste sintering, which can achieve good electrical and mechanical connections, improving the reliability of the printed circuit board. More wiring can be achieved within a limited space, improving the integration of the printed circuit board. Moreover, the buried copper blocks have good heat conduction performance, which can effectively dissipate the heat generated by electronic components, improving the stability and reliability of electronic products.

[0083] The above-described embodiments are only preferred embodiments of the present invention, and do not limit the scope of implementation of the present invention. Except for the situations listed in the specific embodiments; all equivalent changes made according to the method and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A processing method for a printed circuit board with copper blocks sintered by copper paste, characterized in that The processing method includes the following steps: S1. Preparation of upper-layer materials: Prepare the front plug-in layer board CS, the inner layer boards corresponding to each layer of the upper layer, and the buried copper blocks required for buried copper. Milling holes are respectively performed on the front plug-in layer board CS and the inner layer boards corresponding to each layer of the upper layer, and the buried copper holes corresponding to the buried copper blocks are also respectively milled; S2. Treatment of upper-layer prepregs: When milling holes on all upper-layer prepregs, the buried copper holes corresponding to the buried copper blocks are respectively milled; S3. Upper-layer lamination: Align the holes on the front plug-in layer board CS, the inner layer boards corresponding to each layer of the upper layer, and all upper-layer prepregs, and insert the buried copper blocks into the holes and then laminate to form an upper-layer laminate; S4. Preparation of lower-layer materials: Prepare the back welding layer board SS, the inner layer boards corresponding to each layer of the lower layer, and perform punching processing; S5. Treatment of lower-layer prepregs; S6. Lower-layer lamination: Align the holes on the back welding layer board SS, the inner layer boards corresponding to each layer of the lower layer, and all lower-layer prepregs, and perform lamination to form a lower-layer laminate; S7. Preparation of intermediate prepreg materials between the upper and lower layers: Intermediate prepregs are stacked corresponding to between the upper-layer laminate and the lower-layer laminate. Multiple drilling holes for plugging and sintering buried copper paste are drilled in the area of the intermediate prepreg corresponding to the bottom side of the buried copper block; S8. Upper and lower-layer lamination: Stack the upper-layer laminate, the intermediate prepreg, and the lower-layer laminate in sequence, and finally obtain a complete PCB board through lamination; The buried copper blocks are conductively connected to the inner layers through sintering of the copper paste in the drilling holes, and the buried copper blocks are interconnected with any layer of the inner layers by using copper paste sintering connection.

2. The processing method of a copper paste sintered buried copper block printed circuit board according to claim 1, characterized in that Specifically, step S1 further includes: respectively performing blanking → inner light imaging → inner layer etching inspection → punching → milling holes → matching center → brownification processing on the front plug-in layer board CS and the inner layer boards corresponding to each layer of the upper layer.

3. The processing method of a copper paste sintered buried copper block printed circuit board according to claim 1, wherein, Specifically, step S2 further includes: respectively performing blanking → milling holes → auxiliary material matching processing on all upper-layer prepregs stacked corresponding to the upper layer in sequence.

4. The processing method of a copper paste sintered buried copper block printed circuit board according to claim 1, characterized in that, Specifically, step S3 further includes: aligning the holes on the front plug-in layer board CS, the inner layer boards corresponding to each layer of the upper layer, and all upper-layer prepregs, inserting the buried copper blocks into the holes, and then performing lamination → copper reduction → drilling → copper deposition / plating → resin plugging of holes → post-soldermask baking → ceramic grinding of the board → tool matching → inner light imaging → inner layer etching inspection → punching → matching center → brownification processing in sequence to form an upper-layer laminate.

5. The processing method of a copper paste sintered buried copper block printed circuit board according to claim 1, characterized in that, Specifically, step S4 further includes: respectively performing blanking → inner light imaging → inner layer etching inspection → punching → matching center → brownification processing on the back welding layer board SS and the inner layer boards corresponding to each layer of the lower layer.

6. The processing method of a copper paste sintered buried copper block printed circuit board according to claim 1, characterized in that Specifically, step S6 further includes: aligning the holes on the back welding layer board SS, the inner layer boards corresponding to each layer of the lower layer, and all lower-layer prepregs, and performing lamination → copper reduction → drilling → copper deposition / plating → resin plugging of holes → post-soldermask baking → ceramic grinding of the board → tool matching → inner light imaging → inner layer etching inspection → punching → matching center → brownification processing in sequence to form a lower-layer laminate.

7. The processing method of a copper paste sintered buried copper block printed circuit board according to claim 1, wherein, Specifically, step S8 further includes: sequentially stacking the upper laminating part, the intermediate prepreg, and the lower laminating part, and finally obtaining a complete PCB through lamination → drilling → electroless copper plating / plating → resin plugging → post-soldermask baking → ceramic grinding → copper reduction → drilling → electroless copper plating / plating → subsequent normal processes.

8. The processing method of a copper paste sintered buried copper block printed circuit board according to claim 1, wherein, In steps S1, S2, and S3, specifically, it further includes: S1. Upper material preparation: Prepare the front plug-in layer board CS, the first inner layer board L1, the second inner layer board L2, the third inner layer board L3, and the buried copper blocks required for buried copper. Perform blanking → inner light imaging → inner layer etching inspection → punching → milling → matching center → brownification processing on the front plug-in layer board CS, the first inner layer board L1, the second inner layer board L2, and the third inner layer board L3 respectively. Among them, in the milling process, milling holes corresponding to the buried copper blocks are also respectively made on the front plug-in layer board CS, the first inner layer board L1, the second inner layer board L2, and the third inner layer board L3. S2. Upper prepreg processing: Perform blanking → milling → auxiliary material matching processing on the upper corresponding stacked upper prepreg PP1 in sequence. When milling holes on the upper prepreg PP1, milling holes corresponding to the buried copper blocks are respectively made. S3. Upper lamination: Align the holes on the front plug-in layer board CS, the first inner layer board L1, the second inner layer board L2, the third inner layer board L3, and the upper prepreg PP1, embed the buried copper blocks in the holes, and then perform lamination → copper reduction → drilling → electroless copper plating / plating → resin plugging → post-soldermask baking → ceramic grinding → tool matching → inner light imaging → inner layer etching inspection → punching → matching center → brownification processing in sequence to form the upper laminating part.

9. The processing method of a copper paste sintered buried copper block printed circuit board according to claim 1, characterized in that In steps S4, S5, S6, and S7, specifically, it further includes: S4. Lower material preparation: Prepare the back welding layer board SS, the fourth inner layer board L4, the fifth inner layer board L5, and the sixth inner layer board L6. Perform blanking → inner light imaging → inner layer etching inspection → punching → matching center → brownification processing on the back welding layer board SS, the fourth inner layer board L4, the fifth inner layer board L5, and the sixth inner layer board L6 respectively. S5. Lower prepreg processing: Perform blanking → auxiliary material matching processing on the lower corresponding stacked lower prepreg PP3 in sequence. S6. Lower lamination: Align the holes on the back welding layer board SS, the fourth inner layer board L4, the fifth inner layer board L5, the sixth inner layer board L6, and the lower prepreg PP3, and perform lamination → copper reduction → drilling → electroless copper plating / plating → resin plugging → post-soldermask baking → ceramic grinding → tool matching → inner light imaging → inner layer etching inspection → punching → matching center → brownification processing in sequence to form the lower laminating part. S7. Intermediate prepreg material preparation between the upper and lower layers: An intermediate prepreg PP2 for bonding between the upper and lower layers is stacked corresponding to the upper and lower laminating parts. A plurality of uniformly distributed drilling holes for plugging buried copper paste for sintering processing are drilled in the area of the intermediate prepreg PP2 corresponding to the bottom side of the buried copper blocks. The intermediate prepreg PP2 is sequentially subjected to blanking → taping → drilling → copper paste plugging → auxiliary material matching processing.

10. A processing method for a copper paste sintered buried copper block printed circuit board according to claim 1, characterized in that, The number of layers of the printed circuit board is 4 - 20 layers.

11. A PCB combined board, characterized in that, The PCB bonding board is made by using the processing method of a copper paste sintered buried copper block printed circuit board described in any one of claims 1 to 10.

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