Slice hole filling method of printed circuit board, printed circuit board and patch circuit board
By fitting the daughter board on the printed circuit board and closing the slice holes with a cover film, the problem of high scrap rate of the printed circuit board after slice sampling is solved, and the effect of reducing deformation and pollution is achieved.
Patent Information
- Application Number
- CN202510483032.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-16
- Publication Date
- 2025-07-11
AI Technical Summary
The scrap rate of printed circuit boards is high due to structural damage and exposure of slice holes after slice sampling, especially during wet process and pressing process, the problem of infiltration of the potion or depression deformation is prone to occur.
After sampling the slices, the pre-cut daughter plate is fitted into the slice hole and covered with a covering film to prevent the daughter plate from falling off and the infiltration of the potion, and fill the slice hole through the daughter plate to avoid pressing depressions.
It reduces the scrap rate of printed circuit boards after slice sampling, avoids deformation and pollution of printed circuit boards, and improves product quality control.
Smart Images
Figure CN120302533A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of printed circuit board processing, and particularly to a method for filling slice holes of a printed circuit board, a printed circuit board, and a chip-on-board (COB) circuit board. Background Art
[0002] During the production process of a printed circuit board (PCB), due to the complex manufacturing process and the need for repeated build-up manufacturing, various quality problems are inevitable. If there is a lack of effective detection means during the production process, it will be difficult to accurately control the quality of the final product, resulting in an increase in the product rejection rate or the outflow of defective products, significantly increasing the manufacturing cost. Currently, most of the process quality problems in printed circuit board production are difficult to directly observe through conventional planar detection methods, and in-depth observation and detection of the internal structure of the printed circuit board are required. In this context, the metallographic sectioning technique, as a key detection means, can efficiently locate the problem process and accurately reveal the cause of quality defects with its fast and accurate characteristics.
[0003] However, the application of the metallographic sectioning technique has certain limitations. Specifically, this technique requires cutting out a slice with a specific size on the printed circuit board, and this operation will damage the structure of the printed circuit board at the position where the slice is located, making it unable to be put into normal use again. Therefore, each slice sampling will result in the scrapping of a certain number of printed circuit boards. On this basis, the gap left on the board surface after slice sampling is relatively large, which may further increase the rejection rate of the printed circuit board after slice sampling.
[0004] For example, in the wet process stage, if several films are not tightly adhered or are broken by the chemical solution, the chemical solution may penetrate into the slice hole and contaminate the printed circuit board, resulting in abnormal rejection. For another example, during the lamination process, if the printed circuit board has a large thickness and the fluidity of the prepreg resin (PP) is insufficient and cannot completely fill the slice hole, the printed circuit board may be deformed due to filling depressions after the lamination steel plate is pressurized, which will also lead to abnormal rejection. Therefore, how to reduce the rejection rate of the printed circuit board after slice sampling is an urgent problem to be solved in this application. Summary of the Invention
[0005] This application provides a method for filling slice holes of a printed circuit board, a printed circuit board, and a chip-on-board (COB) circuit board, which reduces the rejection rate of the printed circuit board after slice sampling.
[0006] The first aspect of this application provides a method for filling slice holes of a printed circuit board, and the method includes:
[0007] Cut out a metallographic slice with a first preset size on the printed circuit board, so that a slice hole is formed on the printed circuit board after slice sampling;
[0008] Insert the pre-cut sub-board into the slicing hole; wherein, in the length direction and width direction of the printed circuit board, the size of the sub-board is smaller than that of the slicing hole;
[0009] After the sub-board is inserted, attach the pre-cut cover film to both sides of the printed circuit board and cover the two through surfaces of the slicing hole; wherein, the cover film bonds the printed circuit board and the sub-board, and the cover film is used to prevent the sub-board from falling out of the slicing hole; in the length direction and width direction of the printed circuit board, the size of the cover film is larger than that of the slicing hole.
[0010] In a possible design, cutting a metallographic slice with a first preset size on the printed circuit board includes:
[0011] Attach a reinforcement plate under the printed circuit board;
[0012] Cut the printed circuit board and the reinforcement plate synchronously according to the first preset size; wherein, the metallographic slice is cut from the printed circuit board, and the sub-board is cut from the reinforcement plate.
[0013] In a possible design, the synchronous cutting of the printed circuit board and the reinforcement plate is carried out along the direction parallel to the thickness direction of the printed circuit board;
[0014] Then, in the length direction and width direction of the printed circuit board, the size of the sub-board is equal to that of the metallographic slice.
[0015] In a possible design, in the thickness direction of the printed circuit board, the size of the reinforcement plate is equal to that of the printed circuit board.
[0016] In a possible design, in the thickness direction of the printed circuit board, the size of the reinforcement plate is larger than that of the printed circuit board; after the sub-board is inserted, the first end face of the sub-board is flush with the first through surface of the slicing hole;
[0017] Attaching the pre-cut cover film to both sides of the printed circuit board and covering the two through surfaces of the slicing hole includes:
[0018] Attach the cover film to one side of the printed circuit board and cover the first through surface of the slicing hole;
[0019] Grind the second end face of the sub-board until the second end face of the sub-board is flush with the second through surface of the slicing hole;
[0020] Attach the cover film to the other side of the printed circuit board and cover the second through surface of the slicing hole.
[0021] In a possible design, after cutting the printed circuit board and the reinforcement plate synchronously according to the first preset size, the method further includes:
[0022] With the axis in the depth direction of the slicing hole as the center, the printed circuit board and the reinforcing plate are synchronously cut according to a second preset size; wherein, the second preset size is larger than the first preset size.
[0023] In a possible design, before the second end face of the daughter board is polished until it is flush with the second through surface of the slicing hole, the method further includes:
[0024] Inject a filling liquid into the daughter board gap and let it stand until the filling liquid solidifies; wherein, the daughter board gap refers to the gap between the side surface of the daughter board and the side surface of the slicing hole.
[0025] In a possible design, in the length direction and width direction of the printed circuit board, the size of the reinforcing plate is greater than or equal to the size of the printed circuit board;
[0026] Then when cutting the printed circuit board, the reinforcing plate is also used to provide structural support for the printed circuit board.
[0027] The second aspect of the present application provides a printed circuit board, which is processed by using the slicing hole filling method of the printed circuit board in the first aspect.
[0028] The third aspect of the present application provides a patch circuit board, which includes:
[0029] Electronic components, and a printed circuit board as in the second aspect, on which the electronic components are mounted by surface mount technology.
[0030] The fourth aspect of the present application provides an electronic device, which includes:
[0031] Electronic components, and a patch circuit board as in the third aspect, which is communicatively connected to the electronic components.
[0032] A method for filling sliced holes of a printed circuit board, a printed circuit board, and a chip-on-board circuit board provided by this application. The method includes: cutting a metallographic slice with a first preset size on the printed circuit board, so that a sliced hole is formed on the printed circuit board after sampling; fitting a pre-cut sub-board into the sliced hole; wherein, in the length direction and width direction of the printed circuit board, the size of the sub-board is smaller than that of the sliced hole; after the sub-board is fitted, attaching a pre-cut cover film to both sides of the printed circuit board and covering the two through surfaces of the sliced hole; wherein, the cover film bonds the printed circuit board and the sub-board, and the cover film is used to prevent the sub-board from falling out of the sliced hole; in the length direction and width direction of the printed circuit board, the size of the cover film is larger than that of the sliced hole. The following technical effects are achieved: after sampling the printed circuit board slice, fitting the sub-board into the sliced hole, and filling the sliced hole with the sub-board to avoid the pressing depression during pressing, thereby avoiding the deformation of the printed circuit board and reducing the scrap rate of the printed circuit board after sampling; after the sub-board is fitted, covering the sliced hole with the cover film to avoid the infiltration of the chemical solution, thereby avoiding the contamination of the printed circuit board and reducing the scrap rate of the printed circuit board after sampling; bonding the printed circuit board and the sub-board through the cover film to avoid the falling off of the sub-board, and reducing the scrap rate of the printed circuit board after sampling. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] In order to more clearly illustrate the technical solutions in this application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0034] Figure 1 Schematic diagram of the principle of abnormal scrapping of printed circuit boards in the prior art Figure 1 ;
[0035] Figure 2 Schematic diagram of the principle of abnormal scrapping of printed circuit boards in the prior art Figure 2 ;
[0036] Figure 3 Flow schematic diagram of the method for filling sliced holes of the printed circuit board provided by the embodiment of this application Figure 1 ;
[0037] Figure 4 Planar comparison schematic diagram of the printed circuit board before and after cutting provided by the embodiment of this application;
[0038] Figure 5 Sliced comparison schematic diagram of the printed circuit board before and after cutting provided by the embodiment of this application;
[0039] Figure 6Schematic plan view of daughter board fitting provided by an embodiment of the present application;
[0040] Figure 7 Schematic sectional view of daughter board fitting provided by an embodiment of the present application;
[0041] Figure 8 Schematic plan view of cover film bonding provided by an embodiment of the present application;
[0042] Figure 9 Schematic sectional view of cover film bonding provided by an embodiment of the present application;
[0043] Figure 10 Flow schematic of the slice hole filling method for a printed circuit board provided by an embodiment of the present application Figure 2 。
[0044] Reference numerals:
[0045] 110 - dry film;
[0046] 120 - printed circuit board; 121 - slice hole; 122 - daughter board; 123 - cover film;
[0047] 130 - chemical solution;
[0048] 210 - prepreg glue;
[0049] 220 - press plate. Detailed implementation manners
[0050] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.
[0051] In the present application, terms such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and roles. Those skilled in the art can understand that the terms "first" and "second" do not limit the quantity and execution order, and the terms "first" and "second" do not necessarily mean different. It should be noted that in the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly speaking, using words such as "exemplary" or "for example" aims to present relevant concepts in a specific manner. In the present application, "at least one" means one or more, and "a plurality" means two or more.
[0052] It should be noted that the phrase "when... " in this application can refer to the instant when a certain situation occurs or a period of time after a certain situation occurs. This application does not make specific limitations in this regard. In addition, a method for filling sliced holes of a printed circuit board provided in this application is only used as an example, and the method for filling sliced holes of a printed circuit board may also include more or less content. The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in one or more embodiments of this application are all information and data that have been authorized by the user or fully authorized by all parties. And the collection, use, and processing of relevant data need to comply with relevant laws, regulations, and standards, and corresponding operation entrances are provided for users to choose to authorize or refuse.
[0053] For the convenience of clearly describing the technical solutions of this application, the following briefly introduces some terms and technologies involved in this application:
[0054] Printed circuit board: It refers to a board-like structure used to connect and support electronic components in an electronic device. Conductive lines and patterns are printed on an insulating substrate of the printed circuit board to achieve electrical connections between electronic components.
[0055] Build-up manufacturing: In the process of manufacturing a printed circuit board, new conductive layers and insulating layers are added to the original circuit board through a series of process steps to achieve more complex circuit designs and functions.
[0056] Product scrap rate: It refers to the proportion of the number of printed circuit boards that need to be scrapped due to various reasons and cannot meet the quality standards in the total production quantity.
[0057] Flatness detection method: It refers to a method for detecting the surface of a printed circuit board by direct observation or using simple tools, usually used to detect defects such as flatness, scratches, and cracks on the surface of the printed circuit board.
[0058] Wet process stage: It refers to the process stage in the production of a printed circuit board that involves liquid processing such as chemical solution immersion and cleaning. In this stage, the printed circuit board undergoes a series of chemical treatments to achieve specific circuit pattern transfer or surface treatment.
[0059] Dry film: It refers to a photosensitive material used for circuit pattern transfer. The dry film is covered on the surface of the printed circuit board, and through process steps such as exposure and development, the circuit pattern is transferred to the surface of the printed circuit board.
[0060] Lamination process: It refers to the process of combining multiple layers of circuit boards and prepreg adhesives together by means of hot lamination. During the lamination process, the prepreg adhesive will flow and fill the gaps between the circuit boards to form a solid connection.
[0061] Prepreg adhesive: It refers to a semi-cured sheet material used in printed circuit boards, usually composed of resin and reinforcing materials (such as fiberglass cloth).
[0062] To clearly understand the technical solution of this application, the solutions of the prior art will be introduced in detail first.
[0063] During the production process of printed circuit boards, due to the complex manufacturing process and the need for repeated build-up manufacturing, various quality problems are inevitable. If there is a lack of effective detection means during the production process, it will be difficult to accurately control the quality of the final product, resulting in an increase in the product scrap rate or the outflow of defective products, significantly increasing the manufacturing cost. Currently, most of the process quality problems in the production of printed circuit boards are difficult to directly observe through conventional planar detection methods, and it is necessary to conduct in-depth observation and detection of the internal structure of the printed circuit board. In this context, the metallographic sectioning technology, as a key detection means, with its fast and accurate characteristics, can efficiently locate the problem process and accurately reveal the causes of quality defects.
[0064] However, the application of the metallographic sectioning technology has certain limitations. Specifically, this technology requires cutting out slices of specific sizes on the printed circuit board, and this operation will damage the structure of the printed circuit board at the location of the slice, making it unable to be put into normal use again. Therefore, each slice sampling will cause a certain number of printed circuit boards to be scrapped. On this basis, the voids left on the board surface after slice sampling are relatively large, which may further increase the scrap rate of the printed circuit board after slice sampling.
[0065] Figure 1 Schematic diagram of the principle of abnormal scrapping of printed circuit boards in the prior art Figure 1 . As Figure 1 shown, in the wet process stage, several films 110 are not closely attached to the printed circuit board 120 or are broken through by the chemical solution 130. The chemical solution 130 may penetrate into the slice holes 121 of the printed circuit board 120 and contaminate the printed circuit board 120, resulting in abnormal scrapping of the printed circuit board 120.
[0066] Figure 2 Schematic diagram of the principle of abnormal scrapping of printed circuit boards in the prior art Figure 2 . As Figure 2As shown, during the lamination process, if the printed circuit board 120 has a relatively large board thickness and the prepreg glue 210 has insufficient fluidity and cannot completely fill the sliced holes 121, the printed circuit board 120 may have depressions due to the filling of the sliced holes 121 by the prepreg glue 210 after the pressure of the lamination steel plate 220, which may further cause deformation and abnormal scrapping of the printed circuit board 120. It should be noted that during the lamination process, the lamination steel plate 220 presses multiple printed circuit boards 120 together through the prepreg glue 210, Figure 2 Only one of the printed circuit boards 120 is shown therein.
[0067] Therefore, how to reduce the scrapping rate of the printed circuit board after slicing sampling is an urgent problem to be solved in this application.
[0068] Therefore, in view of the above technical problems, it is found in the research that to solve this problem, after the slicing sampling of the printed circuit board is completed, the daughter board is inserted into the sliced holes, and the sliced holes are filled by the daughter board to avoid the lamination depression during lamination, thereby avoiding the deformation of the printed circuit board; at the same time, the sliced holes are covered with a cover film, and the printed circuit board is bonded to the daughter board, which not only avoids the contamination of the printed circuit board caused by the penetration of the chemical solution, but also avoids the detachment of the daughter board.
[0069] Based on the above creative discovery, the technical solution of this application is proposed.
[0070] The technical solution of this application will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below in conjunction with the accompanying drawings of the specification.
[0071] Figure 3 It is a schematic flow chart of the method for filling the sliced holes of the printed circuit board provided by the embodiment of this application Figure 1 As Figure 3 shown, the method for filling the sliced holes of the printed circuit board provided by the embodiment of this application includes the following steps:
[0072] S301. Cut out a metallographic slice with a first preset size on the printed circuit board, so that sliced holes are formed on the printed circuit board after slicing sampling.
[0073] Specifically, a metallographic section refers to a microscopic structure sample obtained from a printed circuit board through laser or mechanical cutting, which is used to detect quality parameters such as interlayer alignment, copper thickness, and resin filling. Then, according to the quality inspection requirements, a first preset size of the metallographic section is determined. For example, a rectangular metallographic section needs to be cut out, with a size of 5mm×8mm, and functional areas such as pads need to be avoided. When cutting the metallographic section, the non-functional area of the printed circuit board is located through Automated Optical Inspection (AOI), the cutting path is planned to avoid differential pairs and power planes, and the metallographic section is cut out by means of ultraviolet laser cutting or the like.
[0074] Furthermore, the metallographic section can be cut by mechanical cutting. To provide sufficient structural support to the printed circuit board, a reinforcing plate can be attached under the printed circuit board.
[0075] Figure 4 FIG. is a schematic plan view of the printed circuit board before and after cutting provided by the embodiment of the present application. Figure 5 FIG. is a schematic section view of the printed circuit board before and after cutting provided by the embodiment of the present application. As Figure 4 and Figure 5 shown, it shows the difference between the printed circuit board 120 before and after section sampling. The hollowed-out area remaining after cutting the metallographic section (i.e., the Figure 4 and Figure 5 dashed box areas in) is the section hole 121.
[0076] It can be understood that from the start of production of the printed circuit board to before section sampling, it can be produced according to the ordinary printed circuit board manufacturing process, for example, including stages such as laser, electroplating, and etching of circuits. The embodiments of the present application will not be elaborated herein.
[0077] S302. Fit the pre-cut sub-board into the section hole.
[0078] Specifically, the sub-board can be cut out separately. Then, the mother board is cut according to the first preset size to obtain the sub-board; the sub-board can also be cut synchronously with the printed circuit board. Then, a mother board, such as a reinforcing plate, is attached under the printed circuit board. When cutting the printed circuit board, the sub-board is cut from the mother board. The material of the mother board can be FR-4 substrate. FR-4 is the code for the flame-resistant material grade of the substrate, indicating the characteristic that the substrate can self-extinguish in the burning state. This material can withstand the lamination temperature of the printed circuit board; its material can also be polytetrafluoroethylene (PTFE). PTFE has excellent chemical stability, corrosion resistance, high and low temperature resistance, low friction coefficient, and non-stickiness, and it can also withstand the lamination temperature of the printed circuit board.
[0079] Figure 6 A schematic plan view of the daughter board fitting provided by the embodiment of the present application Figure 7 A schematic sectional view of the daughter board fitting provided by the embodiment of the present application. As Figure 6 and Figure 7 shown, in the length direction and width direction of the printed circuit board 120, the size of the daughter board 122 is smaller than the size of the slice hole 121, so that the daughter board 122 and the slice hole 121 are in clearance fit, which is convenient for fitting the daughter board 122 into the slice hole 121. In the thickness direction of the printed circuit board 120, the size of the daughter board 122 can be smaller than, equal to or larger than the size of the slice hole 121. When the former is smaller than the latter, the depression caused by the size difference between the two can be filled with a filling liquid to make the sizes of the two the same; when the former is larger than the latter, one side end face of the daughter board 122 can be polished to make the sizes of the two the same.
[0080] Furthermore, the printed circuit board adopts a multi-layer and multi-stage structure, and the thickness of the mother board is determined according to the thickness of the printed circuit board.
[0081] It can be understood that after slicing and sampling, the printed circuit board itself cannot be used normally due to the slice hole. Therefore, filling the slice hole with the daughter board will not increase the scrap rate of the printed circuit board.
[0082] S303. After the daughter board fitting is completed, the pre-cut cover film is attached to both sides of the printed circuit board and covers the two through surfaces of the slice hole.
[0083] Specifically, the cover film bonds the printed circuit board and the daughter board, and the cover film is used to prevent the daughter board from falling off from the slice hole. The material of the cover film can be polyimide (PI) or epoxy resin substrate, etc., which has a certain elongation rate and high temperature resistance. For example, the elongation rate is greater than 50% to ensure no wrinkles during fitting; for another example, it needs to pass the environmental test at 120 °C to ensure that it can withstand the lamination temperature of the printed circuit board.
[0084] Figure 8 A schematic plan view of the cover film attachment provided by the embodiment of the present application Figure 9 A schematic sectional view of the cover film attachment provided by the embodiment of the present application. As Figure 8 and Figure 9 shown, in the length direction and width direction of the printed circuit board 120, the size of the cover film 123 is larger than the size of the slice hole 121 to achieve the sealing of the slice hole 121 and prevent the penetration of the chemical solution. For example, the cover film 123 needs to cover 2 mm outside the edge of the slice hole 121.
[0085] It can be understood that after the cover film is attached to the printed circuit board until the end of production, it can be produced according to the ordinary printed circuit board manufacturing process, such as including lamination, laser and electroplating and other stages, which will not be elaborated in the embodiment of the present application.
[0086] A method for filling sliced holes of a printed circuit board provided by an embodiment of the present application, the method comprising: cutting a metallographic slice with a first preset size on the printed circuit board so that a sliced hole is formed on the printed circuit board after sampling; fitting a pre-cut sub-board into the sliced hole; wherein, in the length direction and width direction of the printed circuit board, the size of the sub-board is smaller than the size of the sliced hole; after the sub-board is fitted, attaching a pre-cut cover film to both sides of the printed circuit board and covering two through surfaces of the sliced hole; wherein, the cover film bonds the printed circuit board and the sub-board, and the cover film is used to prevent the sub-board from falling off from the sliced hole; in the length direction and width direction of the printed circuit board, the size of the cover film is larger than the size of the sliced hole. The following technical effects are achieved: after sampling of the printed circuit board is completed, the sub-board is fitted into the sliced hole, and the sliced hole is filled by the sub-board to avoid press-fitting depression during press-fitting, thereby avoiding deformation of the printed circuit board and reducing the scrap rate of the printed circuit board after sampling; after the sub-board is fitted, the sliced hole is covered by the cover film to avoid penetration of the chemical solution, thereby avoiding contamination of the printed circuit board and reducing the scrap rate of the printed circuit board after sampling; the printed circuit board and the sub-board are bonded by the cover film to avoid the sub-board from falling off, thereby reducing the scrap rate of the printed circuit board after sampling.
[0087] Figure 10 It is a flow schematic of the method for filling sliced holes of the printed circuit board provided by an embodiment of the present application Figure 2 As Figure 10 shown, the method for filling sliced holes of the printed circuit board provided by an embodiment of the present application is a further refinement on the basis of the method for filling sliced holes of the printed circuit board provided by the Figure 3 embodiment. Then the method for filling sliced holes of the printed circuit board provided by this embodiment of the application includes the following steps.
[0088] S101. Attach a reinforcing plate under the printed circuit board.
[0089] Specifically, according to the material and thickness of the printed circuit board, select a suitable reinforcing plate material, such as FR-4 substrate, PTFE or polyimide board, etc., to ensure that the reinforcing plate can be attached under the printed circuit board. Then, through an adhesive, hot melt adhesive or vacuum adsorption, the reinforcing plate is flatly attached under the printed circuit board to ensure that the reinforcing plate is closely attached to the printed circuit board without bubbles or voids.
[0090] In a possible design, in the length direction and width direction of the printed circuit board, the size of the reinforcing plate is greater than or equal to the size of the printed circuit board;
[0091] Then when cutting the printed circuit board, the reinforcing plate is also used to provide structural support for the printed circuit board.
[0092] Specifically, when cutting a metallographic section by mechanical cutting, the cutting stress may cause microcracks and delamination at the edge of the printed circuit board, and the tool impact may cause the copper foil inside the printed circuit board to break or the insulating layer to be damaged. To provide sufficient structural support for the printed circuit board, a reinforcing plate can be attached under the printed circuit board.
[0093] The technical effect of the embodiment of the present application is that the reinforcing plate is closely attached under the printed circuit board. During the cutting process, the reinforcing plate offsets the external force through its own strength and rigidity, increases the support of the printed circuit board, and prevents the printed circuit board from deforming or being damaged during the mechanical cutting process.
[0094] S102. Synchronously cut the printed circuit board and the reinforcing plate according to a first preset size.
[0095] Specifically, according to the first preset size, a cutting method with a synchronous cutting function, such as reciprocating synchronous dynamic cutting or rotary synchronous dynamic cutting, is used to synchronously cut the printed circuit board and the reinforcing plate to obtain a metallographic section and a sub-board with accurate sizes. Among them, the metallographic section is cut from the printed circuit board, and the sub-board is cut from the reinforcing plate.
[0096] During the cutting process, the cutting direction can be parallel to the thickness direction of the printed circuit board, that is, vertical cutting, or at a certain angle to this thickness direction, that is, inclined cutting. When cutting obliquely, the obtained metallographic section is mainly used to expose specific microstructures and reveal the deformation characteristics of the grains of the printed circuit board in different directions; in addition, inclined cutting can also reduce the interlayer stress of the printed circuit board and avoid interlayer separation or peeling that may be caused by vertical cutting.
[0097] In a possible design, the synchronous cutting of the printed circuit board and the reinforcing plate is performed along the direction parallel to the thickness direction of the printed circuit board;
[0098] Then, in the length direction and width direction of the printed circuit board, the size of the sub-board is equal to the size of the metallographic section.
[0099] Specifically, the metallographic section is cut from the printed circuit board. Due to cutting loss, in the length direction and width direction of the printed circuit board, the size of the metallographic section is smaller than the size of the cutting hole, so the metallographic section can be in clearance fit with the cutting hole. When the metallographic section and the sub-board are obtained by vertical cutting, in the length direction and width direction of the printed circuit board, the size of the sub-board is equal to the size of the metallographic section, so the sub-board can also be in clearance fit with the cutting hole.
[0100] The technical effect of the embodiment of the present application is that through horizontal cutting, it is ensured that the sub-board can be in clearance fit with the cutting hole.
[0101] S104. Fit the pre-cut sub-board into the slicing hole.
[0102] After the sub-board is fitted, attach the pre-cut cover film to both sides of the printed circuit board and cover the two through-surfaces of the slicing hole.
[0103] In a possible design, in the thickness direction of the printed circuit board, the size of the reinforcement board is equal to the size of the printed circuit board.
[0104] If their thicknesses are equal, after the sub-board is fitted into the slicing hole, the cover film can be directly attached. At this time, the slicing hole of the printed circuit board is filled.
[0105] In a possible design, in the thickness direction of the printed circuit board, the size of the reinforcement board is larger than the size of the printed circuit board; after the sub-board is fitted, the first end face of the sub-board is flush with the first through-surface of the slicing hole. Among them, the first through-surface of the slicing hole is flush with one of the top end face and the bottom end face of the printed circuit board, and the second through-surface of the slicing hole is flush with the other of the top end face and the bottom end face of the printed circuit board. The second end face of the sub-board refers to the other end face of the sub-board that is parallel to its first end face.
[0106] At this time, in the thickness direction of the printed circuit board, the size of the sub-board is larger than the size of the slicing hole, and the second end face of the sub-board is outside the area between the first through-surface and the second through-surface of the slicing hole, which makes it difficult to ensure the surface flatness of the printed circuit board. Furthermore, during the subsequent lamination process, the printed circuit board is easily affected by stress and deformed, resulting in abnormal scrapping of the printed circuit board. Then attaching the pre-cut cover film to both sides of the printed circuit board and covering the two through-surfaces of the slicing hole includes:
[0107] S105. Attach the cover film to one side of the printed circuit board and cover the first through-surface of the slicing hole.
[0108] Specifically, align the cover film with one side of the printed circuit board and attach it, ensuring that the cover film completely covers the first through-surface of the slicing hole. During the attachment process, tools such as a pressure roller or a squeegee can be used to ensure that the cover film is closely attached to the surface of the printed circuit board. After the attachment is completed, the cover film bonds the printed circuit board and the sub-board, preventing the sub-board from falling out of the slicing hole.
[0109] S107. Grind the second end face of the sub-board until the second end face of the sub-board is flush with the second through-surface of the slicing hole.
[0110] Specifically, use sandpaper, grinding wheels, diamond polishing agents or other grinding tools to polish the second end face of the daughter board. During the polishing process, pressure should be applied evenly to ensure that the polished surface is flat. Polish until the second end face of the daughter board is flush with the second through surface of the slicing hole. After the second end face of the daughter board is polished, it is flush with the second through surface of the slicing hole, ensuring the flatness of the surface of the printed circuit board.
[0111] S108. Attach the cover film to the other side of the printed circuit board and cover the second through surface of the slicing hole.
[0112] Specifically, align the cover film with the other side of the printed circuit board and attach it, ensuring that the cover film completely covers the second through surface of the slicing hole, and bond the printed circuit board and the daughter board to prevent the daughter board from falling out of the slicing hole. This is similar to S105, and the embodiments of the present application will not be elaborated herein.
[0113] In the length and width directions of the printed circuit board, although the size of the daughter board is smaller than the size of the slicing hole cut in one pass to achieve a clearance fit between the two, the two sizes may be too close. When the daughter board is inserted into the slicing hole, it may be difficult to ensure the flatness of the surface of the printed circuit board. Based on this, the following technical solution is proposed.
[0114] In a possible design, after S102, the method further includes:
[0115] S103. Synchronously cut the printed circuit board and the reinforcement board around the axis in the depth direction of the slicing hole according to a second preset size.
[0116] Specifically, in the length and width directions of the printed circuit board, although the size of the daughter board is smaller than the size of the slicing hole cut in one pass to achieve a clearance fit between the two, the two sizes are too close. When the daughter board is inserted into the slicing hole, it may be difficult to ensure the flatness of the surface of the printed circuit board.
[0117] To effectively avoid the above problems, by precisely adjusting the cutting parameters, that is, the second preset size, on the basis of the one-time cutting, the printed circuit board and the reinforcement board are cut synchronously again; wherein, the second preset size is greater than the first preset size. After cutting, the size of the daughter board remains unchanged, and the size of the slicing hole increases. This step further expands the reasonable clearance between the size of the daughter board and the size of the slicing hole, ensuring that the daughter board can be smoothly and stably inserted into the slicing hole while maintaining the high flatness of the surface of the printed circuit board.
[0118] The technical effect of the embodiments of the present application is: The printed circuit board is cut twice according to the second preset size, ensuring that the daughter board can be smoothly and stably inserted into the slicing hole, and avoiding the abnormal scrapping of the printed circuit board.
[0119] In a possible design, after the daughter board is fitted into the printed circuit board that has been secondarily cut, it may wobble in the slicing holes, affecting the overall performance of the printed circuit board. Before S107, the method further includes:
[0120] S106. Inject a filling liquid into the void of the daughter board and let it stand still until the filling liquid solidifies.
[0121] Specifically, the filling liquid should have good fluidity, viscosity, and solidification properties. For example, the filling liquid can be epoxy resin or silica gel, etc. Before the second end face of the daughter board is polished, tools such as a syringe or a dropper are used to uniformly inject the filling liquid into the void of the daughter board. During the injection process, it should be ensured that the filling liquid fills the entire void of the daughter board without bubbles or voids. Herein, the void of the daughter board refers to the void between the side surface of the daughter board and the side surface of the slicing hole; the side surface of the daughter board refers to the surface adjacent to the first end face and the second end face of the daughter board, and the side surface of the slicing hole refers to the surface adjacent to the first through surface and the second through surface of the slicing hole.
[0122] After injecting the filling liquid, let the printed circuit board stand still for a period of time to allow the filling liquid to solidify at room temperature or under heating conditions. The solidification time depends on factors such as the type of the filling liquid and the ambient temperature.
[0123] The technical effect of the embodiment of the present application is that after the filling liquid solidifies, the void of the daughter board is filled, the bonding strength between the daughter board and the slicing hole is enhanced, and the overall performance of the printed circuit board is improved; in addition, the filling liquid also plays a role in fixing and supporting, and cooperates with the cover film to prevent the movement or detachment of the daughter board.
[0124] In a possible design, the synchronous cutting of the printed circuit board and the reinforcement board is performed along a direction inclined to the thickness direction of the printed circuit board; wherein, the surface area of the top end face of the metallographic slice is larger than the surface area of its bottom end face;
[0125] Then, in the length direction and the width direction of the printed circuit board, the size of the daughter board is larger than the size of the metallographic slice.
[0126] The technical effect of the embodiment of the present application is that through the inclined cutting, it is ensured that the daughter board can be in clearance fit with the slicing hole.
[0127] Furthermore, the void of the daughter board corresponding to the inclined cutting is larger than the void of the daughter board corresponding to the vertical cutting, so the surface flatness of the printed circuit board can be guaranteed. Therefore, it is not necessary to synchronously cut the printed circuit board and the reinforcement board again according to the second preset size.
[0128] Furthermore, after the inclined cutting, inject a filling liquid into the void of the daughter board and let it stand still until the filling liquid solidifies. It is similar to S106, and the embodiment of the present application will not elaborate herein.
[0129] In a possible design, in the thickness direction of the printed circuit board, the size of the reinforcing plate is smaller than that of the printed circuit board. Then, the filling liquid can be directly injected into the sub-board gap and left standing until the filling liquid solidifies; alternatively, the printed circuit board and the reinforcing plate can be synchronously cut again according to the second preset size, and then the filling liquid can be injected into the sub-board gap and left standing until the filling liquid solidifies.
[0130] The embodiment of the present application also provides a printed circuit board, and the bare board is processed by using the slice hole filling method of the printed circuit board in the above embodiment.
[0131] It should be noted here that the implementation principle and technical effect of the printed circuit board provided by the embodiment of the present application are similar to those of the slice hole filling method of the printed circuit board in the above embodiment, and the same parts and beneficial effects as those in the method embodiment will not be specifically described herein.
[0132] The embodiment of the present application also provides a patch circuit board, and the patch circuit board includes:
[0133] Electronic components, and a patch circuit board through surface mount technology for mounting the electronic components, such as the patch circuit board in the above device embodiment.
[0134] Specifically, through surface mount technology (SMT), electronic components without pins or short leads, such as resistors, capacitors, integrated circuits (ICs), diodes, and triodes, are mounted on the surface of the printed circuit board, and welding assembly is achieved through methods such as reflow soldering or dip soldering to obtain a patch circuit board. The basic process flow of SMT includes screen printing, component placement, reflow soldering, cleaning, inspection, and repair. These electronic components are precisely mounted on the surface of the printed circuit board through SMT technology, thereby achieving high-density and high-reliability circuit assembly.
[0135] It should be noted here that the implementation principle and technical effect of the patch circuit board provided by the embodiment of the present application are similar to those of the slice hole filling method of the printed circuit board and the printed circuit board in the above embodiment, and the same parts and beneficial effects as those in the method embodiment and the device embodiment will not be specifically described herein.
[0136] The embodiment of the present application also provides an electronic device, and the electronic device includes:
[0137] Electronic components, and a patch circuit board that is communicatively connected to the electronic components, such as the patch circuit board in the above device embodiment.
[0138] Specifically, an electronic component usually refers to a component with relatively independent functions. It can be a complete module or a subsystem in an electronic device, capable of completing specific tasks or functions and communicating or collaborating with other electronic components or devices. Electronic components can be power modules, communication modules, sensor modules, display modules, etc.
[0139] The electronic component is communicatively connected to the surface-mount circuit board to form an electronic device. An electronic device refers to a device composed of electronic components, a surface-mount circuit board, and other mechanical, electrical, and other components, capable of realizing specific functions using electronic technology. An electronic device can be an independent product or a part of a large system, usually having a complex circuit structure and diverse functions, and is widely used in various fields. Electronic devices can be smartphones, laptop computers, smartwatches, smart home devices, industrial control devices, or artificial intelligence (AI) servers, etc.
[0140] It should be noted here that for the electronic device provided in the embodiment of the present application, its implementation principle and technical effects are similar to those of the conductive layer alignment method, the bare board, and the surface-mount circuit board in the above embodiments. Therefore, the parts and beneficial effects that are the same as those in the method embodiment and the device embodiment in this embodiment will not be specifically described herein.
Claims
1. A method for filling sliced holes of a printed circuit board, characterized in that The method includes: Cut a metallographic slice with a first preset size on the printed circuit board, so that a slice hole is formed on the printed circuit board after sampling; Fit the pre-cut daughter board into the slice hole; wherein, in the length direction and width direction of the printed circuit board, the size of the daughter board is smaller than the size of the slice hole; After the daughter board is fitted, attach the pre-cut cover film to both sides of the printed circuit board and cover the two through surfaces of the slice hole; wherein, the cover film bonds the printed circuit board and the daughter board, and the cover film is used to prevent the daughter board from falling off from the slice hole; in the length direction and width direction of the printed circuit board, the size of the cover film is larger than the size of the slice hole.
2. The method for filling a sliced hole of a printed circuit board according to claim 1, wherein, The cutting of the metallographic slice with a first preset size on the printed circuit board includes: Attach a reinforcement plate under the printed circuit board; Cut the printed circuit board and the reinforcement plate synchronously according to the first preset size; wherein, the metallographic slice is cut from the printed circuit board, and the daughter board is cut from the reinforcement plate.
3. The method for filling a sliced hole of a printed circuit board according to claim 2, wherein The synchronous cutting of the printed circuit board and the reinforcement plate is carried out along a direction parallel to the thickness direction of the printed circuit board; Then in the length direction and width direction of the printed circuit board, the size of the daughter board is equal to the size of the metallographic slice.
4. The method for filling the sliced holes of the printed circuit board according to claim 3, wherein, In the thickness direction of the printed circuit board, the size of the reinforcement plate is equal to the size of the printed circuit board.
5. The method for filling a sliced hole of a printed circuit board according to claim 3, wherein In the thickness direction of the printed circuit board, the size of the reinforcement plate is larger than the size of the printed circuit board; after the daughter board is fitted, the first end face of the daughter board is flush with the first through surface of the slice hole; The attaching the pre-cut cover film to both sides of the printed circuit board and covering the two through surfaces of the slice hole includes: Attach the cover film to one side of the printed circuit board and cover the first through surface of the slice hole; Grind the second end face of the daughter board until the second end face of the daughter board is flush with the second through surface of the slice hole; Attach the cover film to the other side of the printed circuit board and cover the second through surface of the slice hole.
6. The method for filling sliced holes of a printed circuit board according to claim 5, characterized in that, After the synchronous cutting of the printed circuit board and the reinforcement plate according to the first preset size, the method further includes: Centering on the axis in the depth direction of the slice hole, cut the printed circuit board and the reinforcement plate synchronously according to a second preset size; wherein, the second preset size is larger than the first preset size.
7. The method for filling the sliced holes of the printed circuit board according to claim 6, characterized in that, Before the grinding treatment of the second end face of the daughter board until the second end face of the daughter board is flush with the second through surface of the slice hole, the method further includes: Inject a filling liquid into the daughter board gap and let it stand until the filling liquid solidifies; wherein, the daughter board gap refers to the gap between the side surface of the daughter board and the side surface of the slice hole.
8. The method for filling a sliced hole of a printed circuit board according to any one of claims 2 to 7, characterized in that, In the length direction and width direction of the printed circuit board, the size of the reinforcement plate is larger than or equal to the size of the printed circuit board; When cutting the printed circuit board, the reinforcing plate is further configured to provide structural support for the printed circuit board.
9. A printed circuit board, characterized in that, The printed circuit board is processed by using the method for filling the slice holes of the printed circuit board according to any one of claims 1 to 8.
10. A patch circuit board, characterized in that, The patch circuit board includes: electronic components, and a printed circuit board as claimed in claim 9, on which the electronic components are mounted by surface mount technology.