A manufacturing method for a high multi-layer circuit board with local multi-frequency compatibility

Abstract

The present invention relates to a manufacturing method, which divides different frequency regions locally on the circuit board of the same motherboard according to different frequency requirements. For different frequency regions, each unit board is separately manufactured. For the manufacture of the motherboard, the motherboard is divided into an inner layer and an outer layer. The inner layer is regarded as a whole, and after the inner layer is prepared according to the manufacturing process of the inner layer of a common high-layer board, a controlled-depth forming corresponding to the corresponding unit board is carried out in the corresponding frequency region to form a board groove. Each unit board is respectively embedded into each corresponding board groove in the inner layer of the motherboard, and then the outer layers are respectively laminated on the top and bottom of the inner layer for laminated pressing, so as to realize the combination of each unit board and the motherboard to obtain a locally multi-frequency multi-layer circuit board. The manufacturing method of the locally multi-frequency compatible high multi-layer circuit board of the present invention has the advantages of simple process, low cost and high quality.

Description

Technical Field

[0001] The present invention relates to the technical field of PCB manufacturing, and specifically to a method for manufacturing high multi-layer circuit boards with local multi-frequency compatibility. Background Art

[0002] With the global popularization of the 5G era, under the condition of meeting the needs of the 5G market, there have been large-scale cross-era changes in electronic information. In terms of materials, all manufacturers are making every effort to improve the high-end performance of their own materials, especially in aspects such as high frequencies that can meet the 5G signal requirements, each having its own advantages. Considering the different application fields of products in the market, there will be materials with different characteristics and frequencies to match the needs of product characteristics at all levels. Similarly, for the circuit board, the mother body of electronic products, there will naturally be designs with different frequency requirements, including ordinary single types and high multi-layer material combinations. Circuit boards with a single material type are generally between 2-layer and 6-layer circuit boards, while those with a material combination type are basically above 8 layers, 20 layers, 32 layers, or even higher. For high multi-layer circuit boards with multi-frequency compatibility, specifically, the combination of the structures of conventional high multi-layer circuit boards is as follows Figure 1 , designed according to different frequency requirements. Different frequencies correspond to different materials, and their structural requirements are also different. For example, layers L2-L3 require material A that can meet a frequency of 200G, layers L6-7 require material B that can meet a frequency of 100G, layers L10-L11 require material C that can meet a frequency of 50G...; 2. For the overall circuit board, the specification data of different materials are all processed as a whole. That is to say, the processing dimensions of each material with different frequencies are the same. In this way, during the processing, the control points of the process must take into account the characteristics of each material. From a design perspective, too many alignment modules of different systems need to be considered to ensure that there are no alignment problems between each other and no scrapping due to deviation; 3. Due to the different material characteristics, especially when several materials are laminated and combined during the processing, a special lamination parameter and control method must be established. This method must take into account that the characteristic requirements of each material are not damaged. Therefore, this lamination condition needs to be tested multiple times to find a parameter between various materials, but it cannot fully meet the original frequency requirements of all materials, resulting in the frequency functional requirements of the processed products not being fully achieved as required by the design end, and only meeting the basic conditions. In summary, when considering different frequencies corresponding to different material combinations, a lot will be paid in terms of design and cost, and the processing technology of the circuit board is much more complex. When considering the processing of various different frequencies and different materials, the process compatibility and quality reliability are particularly complex. For example, the alignment deviation between high multi-layers, the different thermal expansions of materials, and the bonding performance between each other. Summary of the Invention

[0003] The present invention provides a method for manufacturing a high multi-layer circuit board with local multi-frequency compatibility, which has a simple process, low cost and high quality.

[0004] To achieve the above object, it is realized through the following technical solutions.

[0005] A method for manufacturing a high multi-layer circuit board with local multi-frequency compatibility, wherein the manufacturing method is to perform local structural division on different frequency regions on the circuit board of the same mother board according to different frequency requirements, and separately manufacture each unit board for different frequency regions; for the manufacture of the mother board, the mother board is divided into an inner layer and an outer layer. The inner layer is regarded as a whole, and after the inner layer is prepared according to the inner layer manufacturing process of an ordinary high-layer board, a depth control forming corresponding to the corresponding unit board is performed in the corresponding frequency region to form a board groove; each unit board is respectively embedded into each corresponding board groove in the inner layer of the mother board, and then the outer layers are respectively stacked on the top and bottom of the inner layer for stacked lamination, so as to realize the combination of each unit board and the mother board to obtain a multi-layer circuit board with local multi-frequency. The multi-layer circuit board is an n-layer board, where n is a natural number greater than 4.

[0006] Furthermore, each unit board is made of materials selected according to its own frequency requirements. The number of layers of each unit board is the same or different, and the board thickness of each unit board is less than the overall board thickness of the mother board.

[0007] Furthermore, the outer shape of each unit board is designed as a rabbit ear shape, which is composed of a rectangular buried board and arc-shaped rabbit ears respectively located at the four corners of the rectangular buried board.

[0008] Furthermore, the manufacturing process of each unit board includes blanking - inner layer - lamination - drilling - plasma degumming - outer layer - circuit etching - forming, where the outer layer is full-plate electroplating - outer layer pattern, or panel electroplating - outer layer pattern - pattern electroplating.

[0009] Furthermore, for the forming, first perform an arc-shaped rabbit ear forming design, and then use a milling cutter to mill the unit board according to the arc-shaped rabbit ear forming design data, so that arc-shaped rabbit ears are milled out at the four corner positions of the unit board.

[0010] Furthermore, the arc-shaped rabbit ear forming design includes the following steps:

[0011] S1: Select a milling cutter with a size specification that meets the requirements. Among them, the size specification of the milling cutter is: a millimeters;

[0012] S2: According to the size specification of the milling cutter, establish a square with a side length of a millimeters inward from the outermost point of the outer shape.

[0013] S3: Extend outward from the inner end point to the outer end point of the square until the extension line is equal in length to the diagonal of the square.

[0014] S4: Make a perpendicular line segment perpendicular to the extension line with the outer endpoint of the square as the center, and the length of the perpendicular line segment is the side length of the square;

[0015] S5: Construct a first semi-circular arc with the inner endpoint, outer endpoint of the square and one endpoint of the perpendicular line segment as three points, and then mirror the first semi-circular arc with the diagonal as the center to obtain a second semi-circular arc, or construct a second semi-circular arc with the inner endpoint, outer endpoint of the square and the other endpoint of the perpendicular line segment as three points;

[0016] S6: Delete the line segment part of the first semi-circular arc and the second semi-circular arc located inside the square, so that the first semi-circular arc and the second semi-circular arc located outside the square together form an arc-shaped rabbit ear;

[0017] S7: Repeat steps S2 to S6 to complete the design of the arc-shaped rabbit ears at the other three corner positions of the square.

[0018] Further, the manufacturing method includes the following steps,

[0019] S1: The inner layer is manufactured to form an inner layer whole board. After the inner layer whole board is manufactured, depth control forming is carried out on the corresponding frequency area of the inner layer whole board, and board grooves matching the corresponding unit boards are respectively manufactured at the corresponding positions on the inner layer whole board;

[0020] S2: Embed each unit board into the corresponding board groove, and then stack the inner layer whole board between the outer layer bottom board and the outer layer top board respectively, and realize the embedding of the unit board into the mother board through secondary lamination;

[0021] S3: Drill via holes in the whole board after secondary lamination by drilling or laser or depth control drilling, and then electroplate the via holes to metallize them to make the corresponding circuits conductive;

[0022] S4: Outer layer graphics, make circuit graphics on the outer layer for connection with external components;

[0023] S5: Post-process, perform post-processing on the circuit board after the outer layer graphics are made to obtain a complete high-multi-layer circuit board with local multi-frequency compatibility.

[0024] Further, the board grooves on the inner layer are 0.05 mm to 0.30 mm larger than the overall outer shape data of the unit boards at the corresponding positions.

[0025] Further, when the ratio of the thickness and aperture size between L1 and L2, Ln and Ln-1 of the multi-layer circuit board is less than 1, via holes smaller than 0.15 mm are required, and the via holes are burned out by laser operation.

[0026] Further, when the ratio of the thickness to the aperture size between L1 and L2, and between Ln and Ln-1 of the multi-layer circuit board is greater than 1, if a through-hole via is required, the via is drilled by mechanical drilling; if a via to the target layer is required, the via needs to be drilled by controlled-depth drilling operation.

[0027] Compared with the prior art, the method for manufacturing a high multi-layer circuit board with local multi-frequency compatibility of the present invention has the following beneficial effects:

[0028] In response to the requirements for circuit boards with different frequencies and numerous adverse factors in the prior art, the present invention provides a method for manufacturing a high multi-layer circuit board with local multi-frequency compatibility. Specifically, it proposes a requirement for local multi-frequency from the design end, that is, for circuit boards processed with different frequency material combinations as a whole in the early stage, a local different-frequency design is adopted, with local individual operations and then combination, so as to solve the difficulties in the processing technology. Thus, under the requirements of greatly reducing costs and improving quality, the processing technology is simplified, meeting the product requirements and the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is the basic structure diagram of the circuit board in the manufacturing method of a conventional different-frequency high multi-layer board;

[0030] Figure 2 It is the local division diagram of the mother board in the manufacturing method of the high multi-layer circuit board with local multi-frequency compatibility of the present invention;

[0031] Figure 3 It is the basic structure diagram of the circuit board in the manufacturing method of the high multi-layer circuit board with local multi-frequency compatibility of the present invention;

[0032] Figure 4 It is the external shape design diagram of the unit board in the manufacturing method of the high multi-layer circuit board with local multi-frequency compatibility of the present invention;

[0033] Figure 5 For Figure 4 The partial enlarged view of the corner position of the unit board in;

[0034] Figure 6 It is the overall structure diagram of the circuit board in the manufacturing method of the high multi-layer circuit board with local multi-frequency compatibility of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The following will further describe in detail the method for manufacturing a high multi-layer circuit board with local multi-frequency compatibility of the present invention in combination with specific embodiments and the accompanying drawings.

[0036] Refer to Figure 2 and Figure 3, a non-limiting embodiment of the present invention, a method for manufacturing a high multi-layer circuit board with local multi-frequency compatibility. The manufacturing method is to perform local structural division on different frequency regions on the circuit board of the same mother board according to different frequency requirements. For different frequency regions, each unit board is separately manufactured. In this embodiment, on the circuit board of the same mother board, from the perspective of the requirements of the functions after assembling parts, taking the local division of different frequency regions such as A, B, C, D, etc. for different frequency requirements as an example. In this embodiment, the A region part requires A material that meets a frequency of 200G, the B region part requires B material that meets a frequency of 100G, the C region part requires C material that meets a frequency of 50G, and the D region part…( Figure 2 ), after performing local division of different frequencies on the mother board, select corresponding materials according to the A, B, C, D different frequency regions divided locally to prepare each unit board respectively, and start the production of the mother board. The specific production of the mother board is as follows: divide the mother board into an inner layer and an outer layer. The inner layer is regarded as a whole, and after the inner layer is prepared according to the inner layer manufacturing process of an ordinary high-layer board, perform depth control forming corresponding to the corresponding unit board in the corresponding frequency region to form a board groove; embed each unit board into the corresponding board grooves in the inner layer of the mother board respectively, and then stack and press the outer layer on the top and bottom of the inner layer respectively to realize the combination of each unit board and the mother board to obtain a local multi-frequency multi-layer circuit board. The multi-layer circuit board is an n-layer board, where n is a natural number greater than 4. In this technical solution, according to the product performance and different requirements, perform local performance division on the mother board, that is, divide the mother board into different frequency regions, and separately manufacture each unit board required for each frequency region. The unit boards are separately manufactured according to the frequency requirements, and then each unit board is embedded into the corresponding frequency regions in the inner layer of the mother board, realizing the combination of different materials with multiple frequencies, and further realizing the manufacturing of a high multi-layer circuit board with local multi-frequency compatibility. Compared with the problems of high layout cost and difficult processing technology in the whole structure in the prior art, this technical solution performs local performance division on the overall mother board circuit board, that is, divides it into different cells, divides it according to the frequency levels of the corresponding units, processes independently according to their respective material characteristics, and finally combines them together in an ideal and appropriate way, not only realizing the compatibility between each other, but also greatly reducing the processing difficulty.

[0037] Refer to Figure 2 and Figure 3, in a non-limiting embodiment of the present invention, each unit board is made of selected materials according to its respective frequency requirements. The number of layers of each unit board can be the same or different, and the thickness of each unit board is less than the overall thickness of the mother board. Specifically, the number of layers of each unit board is made according to the frequency requirements of the corresponding frequency region. The number of layers of different unit boards can be the same or different. However, to ensure that the unit board can be embedded in the inner layer of the mother board, the thickness of the unit board needs to be less than the overall thickness of the mother board. After the unit board is embedded in the inner layer board, it is laminated and pressed with the outer layer board, providing a basic guarantee for the production of a local multi-frequency high-multi-layer circuit board.

[0038] Refer to Figure 4 and Figure 5 , in a non-limiting embodiment of the present invention, the outer shape of each unit board is designed as a rabbit ear shape, which is composed of a rectangular buried board and arc-shaped rabbit ears located at the four corners of the rectangular buried board respectively. In this embodiment, the unit board is designed in a rabbit ear shape. The rabbit ear part, as a connection point between the unit board and the mother board, is used as the connection part between the unit board and the mother board. On the one hand, it is used for connection, but at the same time, it cannot be too large to affect the divergence of the overall frequency signal. In this embodiment, the design of the rabbit ear-shaped unit board not only plays the role of connecting the unit board and the mother board, but also the connection point of the rabbit ear shape is not too large, which not only better meets the connection between the unit board and the mother board, but also ensures that the connection point will not affect the divergence of the overall frequency signal, ensuring the product quality.

[0039] Refer to Figure 4 and Figure 5 , in a non-limiting embodiment of the present invention, the manufacturing process of each unit board includes blanking - inner layer - lamination - drilling - plasma degumming - outer layer - circuit etching - forming, where the outer layer is full-panel electroplating - outer layer pattern, or panel electroplating - outer layer pattern - pattern electroplating. For the production of the unit board, according to the corresponding frequency requirements, the base material of the corresponding material is selected for the production of the unit board, that is, each unit board completes its respective functional requirements according to its own material characteristics and circuit layout, meeting the requirements of individual independent functionality. It is not only convenient and simple to manufacture, but also the product quality is guaranteed.

[0040] Refer to Figure 4 and Figure 5 , in a non-limiting embodiment of the present invention, for the forming, first, the arc-shaped rabbit ear forming design is carried out, and then the unit board is milled and formed by a milling cutter according to the arc-shaped rabbit ear forming design data, so that arc-shaped rabbit ears are milled at the four corner positions of the unit board. In this embodiment, a milling cutter with a specification of 1.0 mm is used to mill out the unit board with arc-shaped rabbit ears according to the design data.

[0041] Refer to Figure 4 and Figure 5 , in a non-limiting embodiment of the present invention, the arc-shaped rabbit ear forming design data includes

[0042] S1: Select a milling cutter with a size specification that meets the requirements. The size specification of the milling cutter is: a millimeters. In this embodiment, the milling cutter specification is 1.0 millimeters, that is, a is 1.0;

[0043] S2: According to the size specification of the milling cutter, establish a square with a side length of 1.0 millimeters from the outermost endpoints of the shape inward; the size of the side length of the established square is the same as the size of the milling cutter;

[0044] S3: Extend outward from the inner endpoints to the outer endpoints of the square until the extension line is equal in length to the diagonal of the square;

[0045] S4: Make a perpendicular line segment perpendicular to the extension line with the outer endpoint of the square as the center, and the length of the perpendicular line segment is the side length of the square;

[0046] S5: Construct a first semi-circular arc with the inner endpoint, outer endpoint of the square and one endpoint of the perpendicular line segment as three points, and then mirror the first semi-circular arc with the diagonal as the center to obtain a second semi-circular arc, or construct a second semi-circular arc with the inner endpoint, outer endpoint of the square and the other endpoint of the perpendicular line segment as three points;

[0047] S6: Delete the line segment part of the first semi-circular arc and the second semi-circular arc located inside the square, so that the first semi-circular arc and the second semi-circular arc located outside the square together form an arc-shaped rabbit ear;

[0048] S7: Loop through steps S2 to S6 to complete the design of the arc-shaped rabbit ears at the other three corner positions of the square.

[0049] Use the above arc-shaped rabbit ear forming design data to mill out the arc-shaped rabbit ears. The milled arc-shaped rabbit ears can not only serve as the connection points between the unit board and the mother board, making the embedding between the unit board and the mother board stable, but also ensure that the connection points are not too large and do not affect the overall board frequency layout, ensuring product quality.

[0050] Refer to Figures 2 to 6 , a non-limiting embodiment of the present invention, the manufacturing method includes the following steps,

[0051] S1: The inner layer is manufactured to form an inner layer whole board. After the inner layer whole board is manufactured, depth control forming is carried out on the corresponding frequency area of the inner layer whole board, and board grooves that cooperate with the corresponding unit boards are respectively manufactured at the corresponding positions on the inner layer whole board. In this embodiment, as Figure 3 shown, regard L2 to Ln-1 as a whole, that is, the inner layer whole board, and use the high-level ordinary board processing technology to process L2 to Ln-1 to make it a whole, and then perform corresponding depth control forming on the whole of L2 to Ln-1 according to the corresponding positions of the independent unit boards;

[0052] S2: Embed each unit board into the corresponding board slot, then stack the inner-layer whole board between the outer-layer bottom board Ln and the outer-layer top board L1 respectively, and realize the embedding of the unit board into the mother board through secondary lamination.

[0053] S3: Drill through holes in the whole board after secondary lamination by means of drilling, laser or depth-controlled drilling, and then electroplate the through holes to metallize them to conduct the corresponding circuits.

[0054] S4: Outer-layer pattern, make circuit patterns on the outer layer for connecting with external components.

[0055] S5: Post-process, perform post-processing on the circuit board after completing the outer-layer pattern production to obtain a complete high-multi-layer circuit board with local multi-frequency compatibility.

[0056] In this technical solution, according to the product performance and different requirements, local performance division is carried out on the mother board, that is, the mother board is divided into different frequency regions, and each unit board required for each frequency region is manufactured separately. The unit boards are manufactured separately according to the frequency requirements, and then each unit board is embedded into each frequency region of the inner layer of the mother board, realizing the combination of multi-frequencies and different materials, and further realizing the production of a high-multi-layer circuit board with local multi-frequency compatibility. Compared with the problems of high layout cost and difficult processing technology in the existing technology for the whole-block structure, this technical solution divides the overall mother-board circuit board into local performance, that is, divides it into different cells, divides them according to the frequency levels of their corresponding units, processes them independently according to their respective material characteristics, and finally combines them in an ideal way. This not only realizes the compatibility between them, but also greatly reduces the processing difficulty.

[0057] Refer to Figures 2 to 6 , in a non-limiting embodiment of the present invention, the board slot on the inner layer is increased by 0.05 mm to 0.30 mm as a whole compared with the outer shape data of the corresponding unit board, ensuring that the unit board can be smoothly embedded into the board slot on the mother board, and then the unit board is embedded into the inner layer of the mother board to ensure the functions of different frequency regions on the mother board.

[0058] Refer to Figure 6 , in a non-limiting embodiment of the present invention, when the ratio of the thickness and aperture size between L1 and L2, Ln and Ln-1 of the multi-layer circuit board is less than 1, through holes with a size less than 0.15 mm are required, and the through holes are burned out by laser operation.

[0059] Refer to Figure 6 , in a non-limiting embodiment of the present invention, when the ratio of the thickness and aperture size between L1 and L2, Ln and Ln-1 of the multi-layer circuit board is greater than 1, if through holes are required, the through holes are drilled by mechanical drilling; if through holes to the target layer are required, the through holes need to be drilled by depth-controlled drilling operation.

[0060] The above embodiments are only specific embodiments of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as limiting the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these obvious alternative forms all fall within the protection scope of the present invention.

Claims

1. A manufacturing method of a high multi-layer circuit board with local multi-frequency compatibility, characterized in that: The manufacturing method is to make a local structural division of different frequency regions on the circuit board of the same mother board according to different frequency requirements. For different frequency regions, each unit board is separately manufactured. For the manufacture of the mother board, the mother board is divided into an inner layer and an outer layer. The inner layer is regarded as a whole, and after the inner layer is prepared according to the manufacturing process of the inner layer of a common high-layer board, a depth-controlled forming corresponding to the corresponding unit board is carried out in the corresponding frequency region to form a board groove. Each unit board is respectively embedded into each corresponding board groove in the inner layer of the mother board, and then the outer layers are respectively stacked on the top and bottom of the inner layer for stacked lamination, so as to realize the combination of each unit board and the mother board to obtain a local multi-frequency multilayer circuit board. The multilayer circuit board is an n-layer board, where n is a natural number greater than 4. The outer shape of each unit board is designed as a rabbit ear shape. The rabbit ear shape is an arc-shaped rabbit ear composed of a rectangular buried board and arc-shaped rabbit ears respectively located at the four corners of the rectangular buried board. The forming design of the arc-shaped rabbit ear includes the following steps. S1: Select a milling cutter with a size specification that meets the requirements. Among them, the size specification of the milling cutter is: a millimeters. S2: According to the size specification of the milling cutter, establish a square with a side length of a millimeters inward from the outermost point of the outer shape. S3: Extend outward from the inner end point to the outer end point of the square until the extension line is equal in length to the diagonal of the square. S4: Make a perpendicular line segment perpendicular to the extension line with the outer end point of the square as the center. The length of the perpendicular line segment is the side length of the square. S5: Construct a first semi-circular arc with the inner end point, outer end point and one end point of the perpendicular line segment of the square, and then mirror the first semi-circular arc with the diagonal as the center to obtain a second semi-circular arc, or construct a second semi-circular arc with the inner end point, outer end point and the other end point of the perpendicular line segment of the square. S6: Delete the line segment parts of the first semi-circular arc and the second semi-circular arc located inside the square, so that the first semi-circular arc and the second semi-circular arc located outside the square together form an arc-shaped rabbit ear. S7: Repeat steps S2 to S6 to complete the design of the arc-shaped rabbit ears at the other three corner positions of the square.

2. The manufacturing method of the local multi-frequency compatible high-multi-layer circuit board according to claim 1, wherein Each unit board is made of materials according to its respective frequency requirements. The number of layers of each unit board is the same or different, and the board thickness of each unit board is less than the overall board thickness of the mother board.

3. According to the manufacturing method of the high-multilayer circuit board with local multi-frequency compatibility described in claim 2, the manufacturing process of each unit board includes blanking - inner layer - lamination - drilling - plasma degumming - outer layer - circuit etching - forming, where the outer layer is whole-board electroplating - outer layer pattern, or panel electroplating - outer layer pattern - pattern electroplating.

4. The manufacturing method of the local multi-frequency compatible high multi-layer circuit board according to claim 3, characterized in that For the forming, first carry out the forming design of the arc-shaped rabbit ear, and then use a milling cutter to mill the unit board according to the forming design data of the arc-shaped rabbit ear, so that arc-shaped rabbit ears are milled out at the four corner positions of the unit board.

5. According to the manufacturing method of the high-multilayer circuit board with local multi-frequency compatibility described in claim 1, it includes the following steps. S1: The inner layer is manufactured to form an inner-layer whole board. After the inner-layer whole board is manufactured, depth-controlled forming is carried out in the corresponding frequency region on the inner-layer whole board, and board grooves that match the corresponding unit boards are respectively manufactured at corresponding positions on the inner-layer whole board. S2: Insert each unit board into the corresponding board slot, then stack the inner whole board between the outer bottom board and the outer top board respectively, and embed the unit board into the mother board through secondary lamination; S3: Drill through holes in the whole board after secondary lamination by means of mechanical drilling, laser or depth-controlled drilling, and then electroplate the through holes to metallize them to make the corresponding circuits conductive; S4: Outer layer pattern, make circuit patterns on the outer layer for connection with external components; S5: Post-process, perform post-processing on the circuit board after the outer layer pattern is made to obtain a complete local multi-frequency compatible high-multi-layer circuit board.

6. The method for manufacturing a local multi-frequency compatible high multi-layer circuit board according to claim 5, wherein The board slot on the inner layer is increased by 0.05 mm to 0.30 mm as a whole compared with the outer shape data of the unit board at the corresponding position.

7. The method for manufacturing a local multi-frequency compatible high multi-layer circuit board according to any one of claims 1 to 6, characterized in that, When the ratio of the thickness and aperture size between L1 and L2, Ln and Ln-1 of the multi-layer circuit board is less than 1, through holes smaller than 0.15 mm are required, and the through holes are burned out by laser operation.

8. The method for manufacturing a local multi-frequency compatible high multi-layer circuit board according to any one of claims 1 to 6, characterized in that, When the ratio of the thickness and aperture size between L1 and L2, Ln and Ln-1 of the multi-layer circuit board is greater than 1, if through through holes are required, the through holes are drilled by mechanical drilling; if through holes to the target layer are required, the through holes need to be drilled by depth-controlled drilling operation.

Images