A printed circuit board
By filling the shielding holes with copper paste and baking it to cure, the problems of high production costs and reduced bending capacity in the existing technology are solved, achieving the effects of simplified operation and reduced costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DONGGUAN SHENGYI ELECTRONICS
- Filing Date
- 2025-03-20
- Publication Date
- 2026-05-26
AI Technical Summary
Existing technologies require drilling, copper plating, and electroplating processes to create shielding holes, resulting in high production costs, complex processing, and reduced bending capacity of printed circuit boards.
The copper paste is filled into the shielding holes by screen printing, avoiding the copper plating and electroplating processes. The copper paste is then cured by baking to form a shielding effect, simplifying the operation and reducing costs.
This technology ensures the bending performance of printed circuit boards without increasing the thickness of the copper surface, and simplifies the production process, reducing operational difficulty and cost.
Smart Images
Figure CN224290140U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of communication product technology, and in particular to a printed circuit board. Background Technology
[0002] In high-speed communication products, high-speed multilayer flexible circuit boards are used instead of cables for connection in order to reduce wiring area and solve connector bandwidth issues.
[0003] To ensure that multilayer flexible printed circuit boards (FPCBs) meet signal requirements during transmission, the signal line structure needs to be specially designed. For example, to prevent interference with high-speed signals, shielding holes need to be designed on both sides of the product's signal line structure.
[0004] Currently, the production of such products requires drilling, copper plating, and electroplating to create shielding holes, resulting in high production costs. Furthermore, the electroplating parameters must be strictly controlled during production, making the process complex. Additionally, copper plating and electroplating processes increase the thickness of the copper layer on the product surface, leading to a decrease in the product's bending capacity. Utility Model Content
[0005] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a printed circuit board that can reduce the thickness of the copper on the surface of the printed circuit board product, thereby ensuring the product's bending capability.
[0006] According to a first aspect embodiment of the present application, the printed circuit board includes a substrate, a signal line structure is provided inside the substrate, shielding holes are provided on both sides of the signal line structure, and copper paste is filled inside the shielding holes by screen printing, and the copper paste is cured by baking.
[0007] The printed circuit board according to the embodiments of this application has at least the following beneficial effects: shielding holes are provided on both sides of the signal line structure to avoid interference with high-speed signals. The shielding holes are filled with copper paste. The cured copper paste can ensure the shielding effect of the shielding holes and avoid copper plating and electroplating processes during the processing of the shielding holes. This prevents the copper thickness of the product surface caused by copper plating and electroplating processes, ensures the bending ability of the printed circuit board, and reduces costs and operating difficulties.
[0008] According to some embodiments of this application, the substrate includes a first high-speed core board and a second high-speed core board stacked together, and the signal line structure is located between the first high-speed core board and the second high-speed core board.
[0009] According to some embodiments of this application, the first high-speed core board is provided with a first hole, and the second high-speed core board is provided with a second hole. The first hole and the second hole are connected to each other to form the shielding hole that penetrates the substrate.
[0010] According to some embodiments of this application, an adhesive layer is provided between the first high-speed core board and the second high-speed core board, and the first high-speed core board and the second high-speed core board are bonded together by the adhesive layer.
[0011] According to some embodiments of this application, the substrate further includes a plurality of gold finger structures electrically connected to the signal line structure, and each of the gold finger structures is fixedly disposed on opposite sides of the surface of the second high-speed core board facing the first core board.
[0012] According to some embodiments of this application, the size of the first high-speed core board is smaller than the size of the second high-speed core board, and each of the gold finger structures is exposed on the outside of the substrate.
[0013] According to some embodiments of this application, the first high-speed core board is sized by cutting at the edges.
[0014] According to some embodiments of this application, the surface of the first high-speed core board facing away from the second high-speed core board is provided with an upper shielding layer, and the surface of the second high-speed core board facing away from the first high-speed core board is provided with a lower shielding layer, both the upper shielding layer and the lower shielding layer being made of copper.
[0015] According to some embodiments of this application, the shape of the signal line structure is formed on the first high-speed core board and the second high-speed core board by etching.
[0016] According to some embodiments of this application, the edge of the second high-speed core board is provided with a reinforcing structure, and the thickness of the substrate is adjusted by the reinforcing structure.
[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0018] The present application will be further illustrated below with reference to the accompanying drawings and embodiments. It should be noted that the embodiments illustrated in the following drawings are exemplary and are only used to explain the present application, and should not be construed as limiting the present application.
[0019] Figure 1 This is a top view of the printed circuit board according to an embodiment of this application;
[0020] Figure 2 This is a printed circuit board according to an embodiment of this application. Figure 1 Schematic diagram of the structure in the AA direction;
[0021] Figure 3 This is a top view of the printed circuit board manufacturing process of this application embodiment, where the shielding holes have not yet been filled with copper paste;
[0022] Figure 4 This is a printed circuit board according to an embodiment of this application. Figure 3 Schematic diagram of the structure in the middle BB direction;
[0023] Figure 5 This is a top view of the shielding holes after copper paste has been filled during the printing circuit board manufacturing process according to an embodiment of this application.
[0024] Figure 6 This is a printed circuit board according to an embodiment of this application. Figure 5 A schematic diagram of the CC-axis structure.
[0025] Figure label:
[0026] Signal line structure 101; shielding hole 102; copper paste 103;
[0027] First high-speed core board 201; Second high-speed core board 202; Adhesive layer 203; Gold finger structure 204; Adhesive tape 205;
[0028] Upper shielding layer 301; lower shielding layer 302; reinforcing structure 303. Detailed Implementation
[0029] The embodiments of this application are described in detail below with reference to the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0030] In the description of this application, it should be understood that the terms "center", "middle", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0031] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0032] In the description of this application, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0033] In the description of this application, the use of terms such as "one embodiment," "some embodiments," "an example," "some instances," "some embodiments," "illustrative embodiment," "example," "specific example," and "some examples" indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0034] like Figure 1 and Figure 2 As shown in the figure, this application provides a printed circuit board, which includes a substrate. The content of this application is described in detail below with reference to specific embodiments. It should be noted that the following description is merely illustrative and not intended to limit the scope of this application.
[0035] The substrate has a signal line structure 101 inside, which is used for communication and is a stripline structure.
[0036] Furthermore, shielding holes 102 are provided on both sides of the signal line structure 101, and the shielding holes 102 on both sides of the signal line structure 101 are symmetrically arranged about the signal line. In addition, several shielding holes 102 are provided on each side of the signal line.
[0037] Specifically, the shielding hole 102 is a metallized circular hole. The shielding hole 102 utilizes the reflection and absorption of electromagnetic waves by the metal conductor to achieve the shielding effect. When an electromagnetic wave comes into contact with the metal hole, it will be reflected. Most of the electromagnetic wave energy is reflected back to its original direction, and a small amount of electromagnetic wave energy is absorbed by the metal hole.
[0038] It is worth noting that the radius of the shielding hole 102 needs to be less than 1 / 4 of the wavelength of the electromagnetic wave to prevent electromagnetic waves from penetrating the shielding hole 102, thereby achieving shielding of electromagnetic waves of a specific frequency. To ensure the electrical continuity shielding effectiveness of the shielding hole 102, the spacing between adjacent shielding holes 102 shall not exceed 1 / 100 of the wavelength of the maximum operating frequency of the circuit.
[0039] In the traditional fabrication of shielding vias (102), drilling is performed first, followed by complex processes such as copper plating and plating. Understandably, these processes are costly. If a polytetrafluoroethylene (PTFE) substrate is used, strict control of plating parameters is required to avoid poor copper connection, further complicating the process. Simultaneously, plating increases the copper thickness on the substrate, increasing the overall rigidity of the printed circuit board and reducing its bending performance.
[0040] This application eliminates processes such as copper plating and electroplating, which can significantly impact the performance of printed circuit boards. After drilling, this application fills the shielding holes 102 with copper paste 103 to prevent copper from adhering to the outer surface of the substrate, thus avoiding an increase in the surface copper thickness and ensuring the bending performance of the printed circuit board. Simultaneously, filling with copper paste 103 also eliminates the need for parameter control during electroplating, simplifying the operation and reducing costs.
[0041] Specifically, this application uses screen printing to fill the shielding holes 102 with copper paste 103. The copper paste 103 is mainly composed of copper powder, binder, and flux. Copper powder accounts for a large proportion of the copper paste 103 and is the key component that provides conductivity. The binder's role is to bind the copper powder together. The paste-like state of the copper paste 103 allows it to pass smoothly through the stencil holes under the pressure of the printing equipment and fill the shielding holes 102 of the substrate.
[0042] Understandably, after the copper paste 103 is filled into the shielding hole 102, it needs to be baked to cure the copper paste 103 and make the copper paste 103 and the substrate form a whole.
[0043] In some examples, the substrate includes a first high-speed core board 201 and a second high-speed core board 202 stacked together. The high-speed core board is suitable for applications with demanding signal transmission requirements, such as high-speed digital circuits.
[0044] The signal line structure 101 is located between the first high-speed core board 201 and the second high-speed core board 202. Before the first high-speed core board 201 and the second high-speed core board 202 are combined, the first high-speed core board 201 and the second high-speed core board 202 are etched to ensure that the signal line structure 101 can be formed after the two are stacked together.
[0045] In some examples, structurally, the first high-speed core board 201 is provided with a number of first holes, and the second high-speed core board 202 is provided with a number of second holes. Each first hole and each second hole corresponds one-to-one, ensuring that each first hole and each second hole are connected when the first high-speed core board 201 and the second high-speed core board 202 are stacked together. The interconnected first holes and second holes can penetrate the substrate, thereby forming a shielding hole 102 together.
[0046] In the actual processing, the first high-speed core board 201 and the second high-speed core board 202 are first stacked together, and then the shielding hole 102 that penetrates the substrate can be formed by drilling.
[0047] Specifically, both the first high-speed core board 201 and the second high-speed core board 202 are made of polytetrafluoroethylene.
[0048] In some examples, an adhesive layer 203 is provided between the first high-speed core board 201 and the second high-speed core board 202. The adhesive layer 203 is used to bond the first high-speed core board 201 and the second high-speed core board 202, so that the first high-speed core board 201 and the second high-speed core board 202 form a whole. Since the signal line structure 101 is also located between the first high-speed core board 201 and the second high-speed core board 202, the signal line structure 101 is located inside the adhesive layer 203.
[0049] In some examples, the substrate also includes several gold finger structures 204, which are typically gold-plated on the edges of the printed circuit board. Gold is chemically stable, does not easily oxidize, and ensures good conductivity. The gold finger structures 204 appear as rows of neat, finger-shaped metal pieces. In electronic devices, gold fingers are responsible for high-speed signal transmission. In high-speed digital circuits, the gold finger structures 204 can accurately transmit signals.
[0050] The gold finger structure 204 is fixedly disposed on the opposite sides of the second high-speed core board 202, and the signal line structure 101 also extends to the opposite sides of the second high-speed core board 202, so that the two ends of the signal line structure 101 can be electrically connected to the gold finger structure 204 on both sides of the second high-speed core board 202 respectively.
[0051] Specifically, the gold finger structure 204 includes several strip-shaped metal pieces, which are arranged side by side with a certain interval between adjacent metal pieces.
[0052] In some examples, when the first high-speed core plate 201 and the second high-speed core plate 202 are bonded together, the dimensions of the first high-speed core plate 201 and the second high-speed core plate 202 are the same. At this time, the gold finger structure 204 is also sandwiched between the first high-speed core plate 201 and the second high-speed core plate 202. In order to expose the gold finger structure 204 to the outside of the substrate, the dimensions of the first high-speed core plate 201 need to be adjusted.
[0053] Specifically, the size of the first high-speed core board 201 is adjusted to be smaller than the size of the second high-speed core board 202, so that each gold finger structure 204 is exposed to the outside of the substrate.
[0054] In some examples, the edge of the first high-speed core board 201 is cut so that the size of the first high-speed core board 201 is smaller than the size of the second high-speed core board 202, thereby exposing each gold finger structure 204.
[0055] In the cutting process, laser depth control is employed. When the laser irradiates the surface of the first high-speed core plate 201, the first high-speed core plate 201 absorbs laser energy. By controlling parameters such as the laser energy density and pulse frequency, the energy absorbed by the first high-speed core plate 201 can be adjusted. When the absorbed energy reaches a certain level, the first high-speed core plate 201 undergoes physical or chemical changes. During processing, sufficient energy will cause the first high-speed core plate 201 to melt, vaporize, or undergo plasmaization, thereby achieving material removal.
[0056] Specifically, the depth parameter of the laser depth control needs to be less than the sum of the thicknesses of the first high-speed core board 201 and the adhesive layer to avoid laser irradiation onto the gold finger structure 204, which could damage the gold finger structure 204. For example, when the theoretical value of the sum of the thicknesses of the first high-speed core board 201 and the adhesive layer is H, the depth parameter of the laser depth control is set to be between H-0.05mm and H-0.075mm.
[0057] In some examples, an upper shielding layer 301 and a lower shielding layer 302 are provided on the outer side of the substrate. Both the upper shielding layer 301 and the lower shielding layer 302 are made of metal, specifically, both are made of copper. The upper shielding layer 301 and the lower shielding layer 302 help reduce interference from electrical radiation, making them suitable for the transmission of high-frequency signal lines.
[0058] The upper shielding layer 301 is disposed on the surface of the first high-speed core board 201 facing away from the second high-speed core board 202, and the lower shielding layer 302 is disposed on the surface of the second high-speed core board 202 facing away from the first high-speed core board 201.
[0059] In some examples, the edge of the second high-speed core board 202 is provided with a reinforcing structure 303. The reinforcing structure 303 and the gold finger structure 204 are located at opposite ends of the second high-speed core board 202, thereby adjusting the thickness of the printed circuit board plug-in side to facilitate the plug-in connection of the printed circuit board product.
[0060] In the actual implementation process, firstly, the first high-speed core board 201 and the second high-speed core board 202 are exposed and etched to form the pattern of the signal line structure 101.
[0061] Then, adhesive tape 205 is attached to the position of the gold finger structure 204 of the second high-speed core board 202. Considering the alignment tolerance of the attachment, the tape 205 is 0.1mm to 0.15mm larger on one side than the effective area of the gold finger.
[0062] like Figure 3 and Figure 4 As shown, the first high-speed core board 201 and the second high-speed core board 202 are pressed together to form a matrix, and shielding holes 102 are formed by drilling.
[0063] like Figure 5 and Figure 6 As shown, since the shielding holes 102 on the substrate serve only as shielding and do not require reliability testing, to save production time, this application uses copper paste 103 to plug the holes and then metallize them. The copper paste 103 is used to fill the shielding holes 102 using a screen printing method before baking. After baking, the board is ground to remove any excess copper paste near the shielding holes 102. This copper paste plugging method for metallizing the shielding holes 102 avoids the processes of copper plating and electroplating, speeds up the production cycle, and does not increase the thickness of the original base copper, thus improving the bending performance of the substrate.
[0064] like Figure 1 and Figure 2 As shown, laser depth control is performed on the position of the gold finger structure 204, where H is the theoretical thickness of the first high-speed core board 201 plus the thickness of the adhesive layer 203. Considering the uniformity of the medium thickness and the accuracy of laser depth control, the depth of laser depth control is from H-0.05mm to H-0.075mm.
[0065] Finally, by applying immersion gold plating and shaping to the multilayer printed circuit board, a multilayer printed circuit board that can replace the connector can be obtained. The printed circuit board can be laminated and reinforced according to the product specifications to facilitate the insertion and removal of the printed circuit board product.
[0066] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.
Claims
1. A printed circuit board, characterized in that, include: The substrate has a signal line structure inside, and shielding holes are provided on both sides of the signal line structure. The shielding holes are filled with copper paste by screen printing, and the copper paste is cured by baking. The substrate includes a first high-speed core board and a second high-speed core board stacked together, and the signal line structure is located between the first high-speed core board and the second high-speed core board.
2. The printed circuit board according to claim 1, characterized in that, The first high-speed core board has a first hole, and the second high-speed core board has a second hole. The first hole and the second hole are connected to each other to form the shielding hole that penetrates the substrate.
3. The printed circuit board according to claim 1, characterized in that, An adhesive layer is provided between the first high-speed core board and the second high-speed core board, and the first high-speed core board and the second high-speed core board are bonded together by the adhesive layer.
4. The printed circuit board according to claim 3, characterized in that, The substrate also includes a plurality of gold finger structures electrically connected to the signal line structure, and each gold finger structure is fixedly disposed on opposite sides of the surface of the second high-speed core board facing the first high-speed core board.
5. The printed circuit board according to claim 4, characterized in that, The size of the first high-speed core board is smaller than that of the second high-speed core board, and each of the gold finger structures is exposed on the outside of the substrate.
6. The printed circuit board according to claim 5, characterized in that, The first high-speed core board is sized by cutting at the edges.
7. The printed circuit board according to claim 3, characterized in that, The first high-speed core board has an upper shielding layer on the side facing away from the second high-speed core board, and the second high-speed core board has a lower shielding layer on the side facing away from the first high-speed core board. Both the upper shielding layer and the lower shielding layer are made of copper.
8. The printed circuit board according to claim 1, characterized in that, The shape of the signal line structure is formed on the first high-speed core board and the second high-speed core board by etching.
9. The printed circuit board according to claim 1, characterized in that, The edge of the second high-speed core board is provided with a reinforcing structure, and the thickness of the substrate is adjusted by the reinforcing structure.