PCB signal line manufacturing method and device and printed circuit board

Abstract

The invention relates to a PCB signal line manufacturing method and device and a printed circuit board, through the steps of through hole drilling, first-time depth-controlled drilling, electroplating and second-time depth-controlled drilling, multiple sets of signals can pass through one hole in the PCB, on the premise that the performance of an existing PCB is met, the machining technological process is optimized, and the production efficiency is improved. According to the utility model, the wiring density of the signal lines can be increased under the condition that the traditional through hole PCB ensures that the original signal requirement is met, the HDI structure of the product is avoided, and the cost of the product is greatly reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of PCB manufacturing, and in particular to a PCB signal line manufacturing method, device and printed circuit board. Background Art

[0002] With the rapid development of communication technology, the diversification and iterative upgrading of terminal application scenarios have been accelerated. The technology of AI and artificial intelligence has continued to evolve, and terminal products have shown a trend of intelligence, lightness, high frequency and high speed, which has promoted the upgrading of PCB towards high density, high precision, high performance and high efficiency.

[0003] ‌In order to meet the needs of miniaturization, lightness and diversified functions of electronic devices, that is, to accommodate more components in the same size, the PCB processing technology is pushed towards higher layers, denser wiring, smaller line width, and more high-speed signal lines. However, in the existing technology, each signal hole can only carry one set of signals. In order to interconnect multi-layer boards, only as many signal holes as possible can be made on the PCB board. Due to the increase in signal holes, not only the complexity of PCB board manufacturing and the low yield rate caused by the complexity are increased; but also too many signal holes in the PCB board affect the design space of the PCB board, which is contrary to the existing development trend of PCB intelligence, thinness, high frequency and high speed. Summary of the invention

[0004] In view of the above problems, the embodiments of the present invention provide a PCB signal line manufacturing method, device and printed circuit board, which are used to solve the problem that each signal hole in the prior art can only pass one group of signals. In order to interconnect the multi-layer boards, only as many signal holes as possible can be made on the PCB board. Due to the increase in signal holes, not only the complexity of PCB board manufacturing and the low yield rate caused by the complexity are increased; but also too many signal holes designed on the PCB board affect the design space of the PCB board, which is contrary to the existing development trend of PCB intelligence, lightness, thinness, high frequency and high speed.

[0005] According to one aspect of an embodiment of the present invention, a method for manufacturing a PCB signal line is provided, the method comprising: Pretreatment: Forming PCB multilayer boards through cutting, inner layer circuits, and lamination in sequence; Drilling through holes: drilling along a preset area of ​​the PCB multilayer board to form a first through hole; First controlled depth drilling: drilling a first controlled depth hole of a first preset depth at the position of the first through hole through controlled depth drilling to form a second through hole, wherein the diameter of the first controlled depth hole is greater than the diameter of the through hole; Electroplating: forming a conductive layer on the inner wall of the second through hole by electroplating; Second controlled depth drilling: drilling a second controlled depth hole of a second preset depth at the position of the second through hole through controlled depth drilling to form a third through hole, wherein the diameter of the first controlled depth hole is greater than the diameter of the second controlled depth hole, which is greater than the diameter of the first through hole; Resin plugging: Fill the third through hole with resin.

[0006] In some optional embodiments, the second depth-controlled hole is located between the first through hole and the first depth-controlled hole, and the conductive layer located at the position of the second depth-controlled hole is removed through a second depth-controlled drilling step.

[0007] In some optional embodiments, after the first controlled depth drilling step and before the electroplating step, a first high-pressure water washing step is further included, and the first high-pressure water washing specifically includes: The second through hole is flushed along the position of the second through hole by a high-pressure water gun to remove debris in the second through hole.

[0008] In some optional embodiments, after the second controlled depth drilling step and before the resin plugging step, a second high-pressure water washing is further included, and the second high-pressure water washing specifically includes: The third through hole is flushed along the position by a high-pressure water gun to remove debris in the third through hole.

[0009] In some optional embodiments, in the step of drilling through holes, the preset area of ​​the PCB multilayer board is a Z-direction conductive area, and after the target layer board of the PCB multilayer board completes drilling through holes, the copper foil of the target layer board is exposed in the inner wall of the first through hole.

[0010] In some optional embodiments, the drilling of through holes, the first depth-controlled drilling and the second depth-controlled drilling are mechanical drilling or laser drilling.

[0011] In some optional embodiments, in the pretreatment step, forming a PCB multilayer board by cutting, inner layer circuits, and lamination in sequence specifically includes: Cutting: Cut the substrate by a board splitter to form a single-layer substrate; Inner layer circuit: making inner layer circuit on the single-layer substrate; Lamination: Lamination of multiple single-layer substrates with completed inner-layer circuits to form a PCB multi-layer board.

[0012] In some optional embodiments, after the resin plugging step, the following steps are also included in sequence: outer layer circuit, solder mask, surface treatment, molding, testing, FQC, and packaging.

[0013] According to another aspect of an embodiment of the present invention, a PCB signal line manufacturing device is provided, characterized in that the device is used to execute the above-mentioned PCB signal line manufacturing method to manufacture a printed circuit board.

[0014] According to another aspect of an embodiment of the present invention, a printed circuit board is provided. The printed circuit board is manufactured by executing the above-mentioned PCB signal line manufacturing method by the above-mentioned PCB signal line manufacturing device.

[0015] The PCB signal line manufacturing method, device and printed circuit board of the present invention have the following beneficial effects: through the steps of drilling through holes, first controlled depth drilling, electroplating and second controlled depth drilling, drilling along the preset area of ​​the PCB multilayer board is completed to form a first through hole; through controlled depth drilling, a first controlled depth hole of a first preset depth is drilled at the position of the first through hole to form a second through hole; a conductive layer is formed on the inner wall of the second through hole by electroplating; through controlled depth drilling, a second controlled depth hole of a second preset depth is drilled at the position of the second through hole to form a third through hole, wherein the diameter of the first controlled depth hole is greater than the diameter of the second controlled depth hole and greater than the diameter of the first through hole. The present invention realizes that multiple groups of signals are routed through one hole on the PCB board. Under the premise of meeting the performance of the existing PCB, by optimizing the processing process, the traditional through-hole PCB can achieve an increase in the signal line wiring density while ensuring the original signal requirements, avoiding the product from using the HDI structure, and greatly reducing the cost of the product.

[0016] The above description is only an overview of the technical solution of the embodiment of the present invention. In order to more clearly understand the technical means of the embodiment of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings. In the accompanying drawings: Figure 1 A schematic flow chart of a method for manufacturing a PCB signal line according to Embodiment 1 of the present invention is shown; Figure 2 A schematic diagram of the pretreatment process of Example 1 provided by the present invention is shown; Figure 3 The schematic diagram of the process after the resin plugging of the hole in Example 1 provided by the present invention is shown; Figure 4 A schematic structural diagram of a PCB multilayer board in the step of drilling a through hole according to Embodiment 1 of the present invention is shown; Figure 5 A schematic diagram showing the structure of a PCB multilayer board in the first controlled depth drilling step of Example 1 provided by the present invention is shown; Figure 6 A schematic structural diagram of a PCB multilayer board in the electroplating step of Example 1 provided by the present invention is shown; Figure 7 A schematic diagram showing the structure of a PCB multilayer board in the second controlled depth drilling step of Example 1 provided by the present invention is shown; Figure 8 A schematic structural diagram of a PCB multilayer board in the resin plugging step of Example 1 provided by the present invention is shown; DETAILED DESCRIPTION Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0018] Embodiment 1, See also Figure 1 According to one aspect of an embodiment of the present invention, a method for manufacturing PCB signal lines is provided, which can increase the signal line wiring density of a traditional through-hole PCB while ensuring that the original signal requirements are met, avoid the product using an HDI structure, and greatly reduce the cost of the product. The method includes: 110, pretreatment: forming a PCB multilayer board by cutting, inner layer circuit, and pressing in sequence; in step 110, forming a PCB multilayer board by cutting, inner layer circuit, and pressing in sequence, specifically including: cutting: cutting the substrate by a board splitter to form a single-layer substrate; inner layer circuit: making an inner layer circuit on the single-layer substrate; pressing: pressing multiple single-layer substrates with completed inner layer circuits to form a PCB multilayer board.

[0019] 120, drilling through holes: drilling along a preset area of ​​the PCB multilayer board to form a first through hole; in step 120, a channel is formed at a position where the PCB needs to be conductive by mechanical drilling or laser drilling, exposing the copper foil of the conductive layer.

[0020] 130, first controlled depth drilling: by controlled depth drilling, a first controlled depth hole of a first preset depth is drilled at the position of the first through hole to form a second through hole, wherein the diameter of the first controlled depth hole is larger than the diameter of the through hole; in step 130, by controlled depth drilling, a first controlled depth hole for controlling the drilling depth is drilled at the position of drilling the through hole, so that the hole forms a second through hole structure with one end wide and the other end narrow.

[0021] 140, electroplating: forming a conductive layer on the inner wall of the second through hole by electroplating; In step 140, a conductive layer is formed on the inner wall of the second through hole by electroplating, so that the conductive layer is connected to the PCB board and the exposed copper foil of the target layer to form a complete conductive network.

[0022] 150, second controlled depth drilling: through controlled depth drilling, a second controlled depth hole of a second preset depth is drilled at the position of the second through hole to form a third through hole, wherein the diameter of the first controlled depth hole is larger than the diameter of the second controlled depth hole, which is larger than the diameter of the first through hole; in step 150, through controlled depth drilling, at the combination position of drilling the through hole and the first controlled depth drilling, a controlled depth drilling method is adopted to remove the copper at the connection between the first through hole and the first controlled depth hole, so that they form two independent networks, thereby realizing one hole with multiple networks.

[0023] 160, resin plugging: fill the third through hole with resin. In step 160, the joints between different networks after multiple drillings are protected to avoid oxidation and corrosion in subsequent long-term use, so as to obtain more stable quality.

[0024] In a specific embodiment, the PCB multilayer board has 10 single-layer substrates L1-L10. Figure 4 , through step 120, drilling a through hole; drilling a first through hole 2 on the PCB multilayer board 1. Figure 5 , through step 130, the first depth-controlled drilling is performed to drill a first depth-controlled hole 3 at one end of the first through hole 2. Figure 6 , through step 140, electroplating, a conductive layer 4 is formed on the outer layer of the first through hole and the first depth control hole, wherein the conductive material of the conductive layer can be copper. Figure 7 , through step 150, the second depth-controlled drilling is performed; a second depth-controlled hole 5 is drilled at the connection between the first through hole and the first depth-controlled hole. Figure 8 , through step 160, resin plugging is performed to fill the third through hole with resin 6 to protect the circuit in the third through hole.

[0025] The present invention completes drilling along the preset area of ​​the PCB multilayer board by drilling through holes, first controlled depth drilling, electroplating, and second controlled depth drilling steps to form a first through hole; a first controlled depth hole of a first preset depth is drilled at the position of the first through hole by controlled depth drilling to form a second through hole; a conductive layer is formed on the inner wall of the second through hole by electroplating; a second controlled depth hole of a second preset depth is drilled at the position of the second through hole by controlled depth drilling to form a third through hole, wherein the diameter of the first controlled depth hole is greater than the diameter of the second controlled depth hole and greater than the diameter of the first through hole. The present invention realizes that multiple groups of signals are routed through one hole on the PCB board. Under the premise of meeting the performance of the existing PCB, by optimizing the processing process, the traditional through-hole PCB can achieve an increase in the signal line wiring density while ensuring the original signal requirements are met, avoiding the product from using an HDI structure, and greatly reducing the cost of the product.

[0026] In some optional embodiments, the second depth-controlled hole is located between the first through hole and the first depth-controlled hole, and the conductive layer located at the second depth-controlled hole is removed by the second depth-controlled drilling step. In this embodiment, by depth-controlled drilling, at the combination of drilling the through hole and the first depth-controlled drilling, the copper at the connection between the first through hole and the first depth-controlled hole is removed by a depth-controlled drilling method, so that two independent networks are formed, thereby realizing one hole with multiple networks.

[0027] In some optional embodiments, after the first controlled depth drilling step and before the electroplating step, a first high-pressure water washing is further included, and the first high-pressure water washing specifically includes: flushing along the second through hole position by a high-pressure water gun to remove debris in the second through hole. In this step, the purpose of adding high-pressure water washing is mainly to remove the poor chip removal of the controlled depth hole by the controlled depth drilling equipment after the controlled depth drilling, and to use the impact of high-pressure water to remove the debris that has not been cleaned out in the controlled depth hole.

[0028] In some optional embodiments, after the second controlled depth drilling step and before the resin plugging step, a second high-pressure water washing is further included, and the second high-pressure water washing specifically includes: flushing along the position of the third through hole with a high-pressure water gun to remove debris in the third through hole. In this step, the purpose of adding high-pressure water washing is mainly to remove the poor chip removal of the controlled depth hole by the controlled depth drilling equipment after the controlled depth drilling, and to use the impact of high-pressure water to remove the debris that has not been removed cleanly in the controlled depth hole.

[0029] In some optional embodiments, in the step of drilling through holes, the preset area of ​​the PCB multilayer board is the Z-direction conductive area, and after the target layer board of the PCB multilayer board is completed with drilling through holes, the copper foil of the target layer board is exposed in the inner wall of the first through hole. In this step, a channel is formed at the position where the PCB needs to be conductive by mechanical drilling or laser drilling, and the copper foil of the conductive layer is exposed. A conductive layer is formed on the inner wall of the second through hole by electroplating, so that the conductive layer is connected to the PCB board and the exposed copper foil of the target layer board to form a completed conductive network.

[0030] In some optional embodiments, the through hole drilling, the first controlled depth drilling and the second controlled depth drilling are mechanical drilling or laser drilling. In this step, a suitable drilling method can be selected according to the precision requirements of the PCB board production. Mechanical drilling has lower cost and laser drilling has higher precision.

[0031] In some optional embodiments, see Figure 2In the pretreatment step, a PCB multilayer board is formed in sequence through cutting, inner layer circuit, and pressing, which specifically includes: 210, cutting: cutting the substrate by a board splitter to form a single-layer substrate; in step 210, cutting is to use an automatic slitting machine to cut the substrate material into a core board. 220, inner layer circuit: make an inner layer circuit on the single-layer substrate; in step 220, stick a dry film on the surface of the single-layer substrate to prepare for subsequent image transfer; use an exposure device to expose the coated substrate with ultraviolet light, so as to transfer the image of the substrate to the dry film; develop, etch, and remove the exposed substrate to complete the production of the inner layer board. 230, pressing: press multiple single-layer substrates with completed inner layer circuits to form a PCB multilayer board; in step 230, press multiple single-layer substrates once or multiple times to form a PCB multilayer board.

[0032] In some optional embodiments, see Figure 3 After the resin plugging step, the following steps are also included: 310, outer layer circuit; in step 310, the board surface is cleaned by pickling, brushing and drying to increase the adhesion of the dry film; the dry film is attached to the surface of the PCB substrate to prepare for the subsequent image transfer; UV light is irradiated to make the dry film on the board form a polymerized and unpolymerized state; the dry film that is not polymerized during the exposure process is dissolved to leave a gap. 320, solder mask; in step 320, the surface of the PCB multilayer board is treated with solder mask to prevent oxidation and other phenomena. 330, surface treatment; in step 330, the side of the bare copper plate to be welded is coated to form an organic film to prevent rust and oxidation, including pickling, ultrasonic water washing and other processes to remove the board oxide and increase the roughness of the copper surface; the solder mask ink is covered where the PCB multilayer board does not need to be welded, which plays a role of protection and insulation; the solvent in the solder mask ink is dried and the ink is hardened for exposure; the solder mask ink is cured by UV light and a high molecular polymer is formed by photosensitive polymerization; the sodium carbonate solution in the unpolymerized ink is removed; the ink is completely hardened. 340, molding; the board shape required by the customer is produced to facilitate the customer to carry out patch and assembly. 350, testing; in step 350, the board circuit is tested to avoid the outflow of defective boards with short circuits. 360, FQC; in step 360, the final inspection is carried out, and a full sampling inspection is carried out after all processes are completed. 370, packaging; in step 370, the finished PCB multilayer board is vacuum packed, packaged and shipped, and the delivery is completed.

[0033] Embodiment 2: According to another aspect of an embodiment of the present invention, a PCB signal line manufacturing device is provided, and the device is used to execute the above-mentioned PCB signal line manufacturing method to manufacture a printed circuit board. In this embodiment, the following steps are performed by the PCB signal line manufacturing device: 110, pretreatment: forming a PCB multilayer board through cutting, inner layer circuit, and lamination in sequence; 120, drilling through holes: drilling along a preset area of ​​the PCB multilayer board to form a first through hole; 130, first controlled depth drilling: drilling a first controlled depth hole of a first preset depth at the position of the first through hole through controlled depth drilling to form a second through hole, wherein the diameter of the first controlled depth hole is greater than the diameter of the through hole; 140, electroplating: forming a conductive layer on the inner wall of the second through hole by electroplating; 150, second depth-controlled drilling: drilling a second depth-controlled hole of a second preset depth at the position of the second through hole through depth-controlled drilling to form a third through hole, wherein the diameter of the first depth-controlled hole is greater than the diameter of the second depth-controlled hole, which is greater than the diameter of the first through hole; 160 , resin plugging hole: filling the third through hole with resin.

[0034] The present invention completes drilling along the preset area of ​​the PCB multilayer board by drilling through holes, first controlled depth drilling, electroplating, and second controlled depth drilling steps to form a first through hole; a first controlled depth hole of a first preset depth is drilled at the position of the first through hole by controlled depth drilling to form a second through hole; a conductive layer is formed on the inner wall of the second through hole by electroplating; a second controlled depth hole of a second preset depth is drilled at the position of the second through hole by controlled depth drilling to form a third through hole, wherein the diameter of the first controlled depth hole is greater than the diameter of the second controlled depth hole and greater than the diameter of the first through hole. The present invention realizes that multiple groups of signals are routed through one hole on the PCB board. Under the premise of meeting the performance of the existing PCB, by optimizing the processing process, the traditional through-hole PCB can achieve an increase in the signal line wiring density while ensuring the original signal requirements are met, avoiding the product from using an HDI structure, and greatly reducing the cost of the product.

[0035] Embodiment 3: According to another aspect of an embodiment of the present invention, a printed circuit board is provided, and the printed circuit board is manufactured by executing the above-mentioned PCB signal line manufacturing method through the above-mentioned PCB signal line manufacturing device. The present invention completes drilling along the preset area of ​​the PCB multilayer board to form a first through hole by drilling a through hole, first depth-controlled drilling, electroplating, and second depth-controlled drilling steps; a first controlled depth hole of a first preset depth is drilled at the position of the first through hole to form a second through hole; a conductive layer is formed on the inner wall of the second through hole by electroplating; a second controlled depth hole of a second preset depth is drilled at the position of the second through hole by depth-controlled drilling to form a third through hole, wherein the diameter of the first controlled depth hole is greater than the diameter of the second controlled depth hole and greater than the diameter of the first through hole. The present invention realizes that multiple groups of signals are routed through one hole on the PCB board. Under the premise of meeting the performance of the existing PCB, by optimizing the processing process, the traditional through-hole PCB can achieve an increase in the signal line wiring density while ensuring the original signal requirements, avoiding the product from using the HDI structure, and greatly reducing the cost of the product.

[0036] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. Similarly, in order to simplify the present invention and help understand one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, the various features of the embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. Wherein, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself is a separate embodiment of the present invention.

[0037] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and further may be divided into a plurality of submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive.

[0038] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of multiple such elements. The present invention may be implemented with the aid of hardware comprising several different elements and with the aid of appropriately programmed computers. In a unit claim that lists several systems, several of these systems may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be understood as limitations on the order of execution.

Claims

1. A method for manufacturing a PCB signal line, characterized in that: The method comprises: Pretreatment: Forming PCB multilayer boards through cutting, inner layer circuits, and lamination in sequence; Drilling through holes: drilling along a preset area of ​​the PCB multilayer board to form a first through hole; First controlled depth drilling: drilling a first controlled depth hole of a first preset depth at the position of the first through hole through controlled depth drilling to form a second through hole, wherein the diameter of the first controlled depth hole is greater than the diameter of the through hole; Electroplating: forming a conductive layer on the inner wall of the second through hole by electroplating; Second controlled depth drilling: drilling a second controlled depth hole of a second preset depth at the position of the second through hole through controlled depth drilling to form a third through hole, wherein the diameter of the first controlled depth hole is greater than the diameter of the second controlled depth hole, which is greater than the diameter of the first through hole; Resin plugging: Fill the third through hole with resin.

2. The PCB signal line manufacturing method according to claim 1, characterized in that: The second depth-controlled hole is located between the first through hole and the first depth-controlled hole, and the conductive layer located at the position of the second depth-controlled hole is removed through the second depth-controlled drilling step.

3. The PCB signal line manufacturing method according to claim 2, characterized in that: After the first controlled depth drilling step and before the electroplating step, a first high-pressure water washing step is also included, and the first high-pressure water washing specifically includes: The second through hole is flushed along the position of the second through hole by a high-pressure water gun to remove debris in the second through hole.

4. The method for manufacturing a PCB signal line according to claim 3, characterized in that: After the second controlled depth drilling step and before the resin plugging step, a second high-pressure water washing is also included, and the second high-pressure water washing specifically includes: The third through hole is flushed along the position by a high-pressure water gun to remove debris in the third through hole.

5. The method for manufacturing a PCB signal line according to claim 1, characterized in that: In the step of drilling through holes, the preset area of ​​the PCB multilayer board is a Z-direction conductive area, and after the target layer board of the PCB multilayer board is drilled through, the copper foil of the target layer board is exposed in the inner wall of the first through hole.

6. The method for manufacturing a PCB signal line according to claim 1, characterized in that: The through-hole drilling, the first depth-controlled drilling and the second depth-controlled drilling are mechanical drilling or laser drilling.

7. The method for manufacturing a PCB signal line according to claim 1, characterized in that: In the pretreatment step, the PCB multilayer board is formed by cutting, inner layer circuit, and pressing in sequence, which specifically includes: Cutting: Cut the substrate by a board splitter to form a single-layer substrate; Inner layer circuit: making inner layer circuit on the single-layer substrate; Lamination: Lamination of multiple single-layer substrates with completed inner-layer circuits to form a PCB multi-layer board.

8. The method for manufacturing a PCB signal line according to claim 1, characterized in that: After the resin plugging step, the following steps are also included in sequence: outer layer circuit, solder mask, surface treatment, molding, testing, FQC, and packaging.

9. A PCB signal line manufacturing device, characterized in that: The device is used to execute the PCB signal line manufacturing method described in any one of claims 1 to 8 to manufacture a printed circuit board.

10. A printed circuit board, characterized in that: The printed circuit board is manufactured by using the PCB signal line manufacturing device described in claim 9 to execute the PCB signal line manufacturing method described in any one of claims 1 to 8.

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