Method for manufacturing stepped golden finger circuit board and stepped golden finger circuit board

Abstract

The embodiment of the invention provides a method for manufacturing a stepped golden finger circuit board and the stepped golden finger circuit board. The method comprises the following steps: manufacturing a golden finger on at least one side of a substrate; bonding a protective film on the substrate by using an adhesive substance so as to cover the golden fingers; laminating and pressing the prepreg and the copper foil on one side, where the protective film is attached, of the substrate; wherein the viscous substance loses viscosity in the pressing process; removing a part of the prepreg and a part of the copper foil to form a stepped groove so as to expose the protective film; and removing the protective film to obtain the stepped golden finger circuit board. The method is used for achieving the effects of reducing pollution to the golden fingers and ensuring the performance of the stepped golden finger circuit board.

Description

Technical Field

[0001] This application relates to the field of circuit board manufacturing technology, and in particular to a method for manufacturing a stepped gold finger circuit board and a stepped gold finger circuit board. Background Technology

[0002] Gold fingers are a series of gold-plated contacts arranged along the edge of a circuit board, used to establish an electrical connection with the connector. With the development of 5G communication technology and the demand for multi-functionality, communication equipment and networks are evolving towards high speed and high capacity. Components on circuit boards are becoming increasingly complex, and their heights may vary. To accommodate these height differences and ensure accurate contact between the gold fingers and the connector, even on uneven surfaces, grooves or steps are typically created at specific locations on the circuit board—a process known as stepped grooves.

[0003] Existing technology typically involves creating stepped gold fingers in subsequent processes using controlled-depth milling to open the cover. However, as the thickness of high-end communication printed circuit boards increases, the thickness variation of the printed circuit boards also increases, making controlled-depth milling of the stepped gold finger area more difficult. If the controlled-depth milling is too deep, it is easy to mill the gold fingers; if the controlled-depth milling is too shallow, too much residual adhesive will remain on the gold fingers, causing contamination and resulting in poor circuit board performance. Summary of the Invention

[0004] This application provides a method for manufacturing a stepped gold finger circuit board and a stepped gold finger circuit board, in order to reduce contamination of the gold finger.

[0005] In a first aspect, embodiments of this application provide a method for manufacturing a stepped gold finger circuit board, comprising:

[0006] Gold fingers are formed on at least one side of the substrate;

[0007] A protective film is adhered to the substrate using an adhesive substance to cover the gold fingers;

[0008] A prepreg and copper foil are laminated on the side of the substrate where a protective film is attached; wherein the adhesive material loses its adhesiveness during the lamination process.

[0009] Remove a portion of the prepreg and a portion of the copper foil to form a stepped groove, thereby exposing the protective film;

[0010] Remove the protective film to obtain the stepped gold finger circuit board.

[0011] In one possible implementation, the method of using an adhesive material to bond the protective film onto the substrate to cover the gold fingers includes:

[0012] The adhesive substance is coated on one side of the protective film;

[0013] The side of the protective film coated with the adhesive substance is bonded to the side of the substrate on which the gold fingers are provided.

[0014] In one possible implementation, the protective film is located within the stepped groove, and the shortest distance from the boundary of the protective film to the wall of the stepped groove is 0.01 mm to 0.02 mm.

[0015] In one possible implementation, the thickness of the protective film is greater than or equal to 0.05 mm.

[0016] In one possible implementation, the protective film is a PI film.

[0017] In one possible implementation, the degradation temperature of the protective film is greater than or equal to a first preset temperature.

[0018] In one possible implementation, the viscous substance is viscous in an environment with a temperature lower than a second preset temperature, and loses its viscousness in an environment with a temperature greater than or equal to the second preset temperature, wherein the second preset temperature is lower than the first preset temperature.

[0019] In one possible implementation, the prepreg and copper foil are laminated on the side of the substrate where the protective film is attached, including:

[0020] The prepreg and the copper foil are laminated to the side of the substrate with the protective film attached at a third preset temperature, wherein the third preset temperature is less than the first preset temperature and greater than or equal to the second preset temperature.

[0021] In one possible implementation, the prepreg and copper foil are laminated on the side of the substrate where the protective film is attached, including:

[0022] At least two layers of the copper foil and two layers of the prepreg are laminated together on the side of the substrate to which the protective film is attached.

[0023] In one possible implementation, removing a portion of the prepreg and a portion of the copper foil to form a stepped groove includes:

[0024] The prepreg and the copper foil are subjected to controlled-depth milling to form the stepped groove.

[0025] Determine the boundary location of the first region; the first region is the area where the copper foil and the protective film overlap in the vertical direction;

[0026] The boundary position of the first region is expanded according to a preset increment to obtain the boundary position of the second region;

[0027] The prepreg and copper foil are milled at controlled depth along the boundary of the second region until the substrate is exposed, forming a stepped groove.

[0028] Secondly, embodiments of this application provide a stepped gold finger circuit board, which is manufactured by the first aspect and / or various possible implementations of the first aspect.

[0029] The method and circuit for manufacturing stepped gold finger circuit boards provided in this application involve bonding a protective film to a substrate to cover the gold fingers on the substrate. Then, a prepreg and copper foil are laminated and pressed together on the side of the substrate with the protective film attached. Since the adhesive between the protective film and the substrate loses its adhesiveness during the pressing process, when removing the protective film, the adhesive material may only adhere to a small amount or even not adhere to the gold fingers. Because the adhesive material loses its adhesiveness during the pressing process, the adhesiveness of the adhesive material will become very little or even non-existent after the pressing process. Therefore, even if a small amount of adhesive material adheres to the gold fingers, it can be easily removed from the gold fingers, thereby reducing contamination of the gold fingers and ensuring the performance of the stepped gold finger circuit board. Attached Figure Description

[0030] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0031] Figure 1 A flowchart illustrating the fabrication of a stepped gold finger circuit provided in this application;

[0032] Figure 2(a) is a schematic diagram of the structure obtained after gold fingers are fabricated on one side of the substrate according to this application;

[0033] Figure 2(b) is a schematic diagram of the structure obtained by attaching a protective film to one side of the substrate to cover the gold fingers, as provided in this application.

[0034] Figure 2(c) is a schematic diagram of the structure obtained by laminating and pressing copper foil and prepreg on the side of the substrate with a protective film attached, as provided in this application.

[0035] Figure 2(d) is a schematic diagram of the structure obtained after partially removing the copper foil and prepreg on one side of the substrate according to this application.

[0036] Figure 2(e) is a schematic diagram of the structure obtained after a stepped gold finger is fabricated on one side of the substrate according to this application;

[0037] Figure 3(a) is a schematic diagram of the structure obtained after gold fingers are fabricated on both sides of the substrate according to this application;

[0038] Figure 3(b) is a schematic diagram of the structure obtained by attaching protective films to both sides of the substrate to cover the gold fingers, as provided in this application.

[0039] Figure 3(c) is a schematic diagram of the structure obtained by laminating copper foil and prepreg on both sides of the substrate according to this application.

[0040] Figure 3(d) is a schematic diagram of the structure obtained after partially removing the copper foil and the prepreg on both sides of the substrate according to this application.

[0041] Figure 3(e) is a schematic diagram of the structure obtained after step-shaped gold fingers are fabricated on both sides of the substrate according to this application.

[0042] Figure descriptions: 1. Substrate; 2. Copper foil; 3. Gold fingers; 4. Protective film; 5. Prepreg; 6. Substrate.

[0043] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0044] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0045] Existing technologies include methods for creating stepped gold fingers in subsequent processes by controlling the depth of milling to open the cap, as well as pressing low-flow prepreg and controlling the depth of milling grooves, and placing gaskets in the grooves.

[0046] The method of creating stepped gold fingers in the subsequent process by controlling the depth of milling requires controlling the depth of milling the entire copper foil and prepreg above the gold finger projection. However, as the thickness of high-end communication printed circuit boards increases, the thickness difference of the printed circuit boards also increases, which brings greater processing difficulty to the controlling the depth of milling in the stepped gold finger area. If the controlling depth of milling is too deep, it is easy to mill the gold fingers; if the controlling depth of milling is too shallow, there will be too much residual adhesive on the gold fingers, causing contamination of the gold fingers and resulting in poor circuit board performance.

[0047] The method of creating stepped gold fingers by laminating low-flow prepreg and milling grooves with controlled depth, and then placing spacers within the grooves, requires first milling controlled depth on the substrate to form stepped grooves, then placing spacers at the bottom of the stepped grooves, and finally laminating again on the substrate with the spacers. Gold fingers are then fabricated on top of the spacers, forming a stepped gold finger circuit board. However, this method requires high precision in the position and dimensions of the grooves, as well as high positioning accuracy of the spacers. Large deviations in the position and dimensions of the grooves will result in poor performance of the final stepped gold finger circuit board. The positioning accuracy of the spacers directly affects the height of the stepped grooves; significant differences in positioning accuracy between spacers will lead to inconsistent heights of the stepped gold fingers, affecting the connection between the gold fingers and other electronic components, thus directly impacting the normal use of the stepped gold finger circuit board. Furthermore, the groove-making process can easily cause substrate breakage, affecting the performance of the stepped gold finger circuit board. Also, this method of placing spacers cannot produce double-sided stepped gold fingers, only single-sided ones.

[0048] To address the aforementioned issues, this embodiment provides a method for fabricating a stepped gold finger circuit board and the stepped gold fingers themselves. First, gold fingers are fabricated on a substrate, and then a protective film is applied to cover the gold fingers. The protective film is adhered to the substrate with adhesive, achieving the effect of covering the gold fingers. Simultaneously, the adhesive strength of this adhesive is lost during the high-temperature, high-pressure pressing process. Then, copper foil and a prepreg are laminated onto the substrate. This not only allows the copper foil to adhere to the substrate but also causes the adhesive between the protective film and the substrate to lose its stickiness. At this point, deep milling is performed on the copper foil surrounding the protective film, allowing for easy removal of both the copper foil above the protective film and the protective film itself. Therefore, the method for fabricating a stepped gold finger circuit board provided in this embodiment eliminates the need for pre-grooving and placing gaskets in the stepped gold finger area, thus reducing the difficulty of manufacturing stepped gold fingers. Meanwhile, the method for manufacturing stepped gold finger circuit boards provided in this application only requires controlled-depth milling around the protective film to easily remove unwanted copper foil and prepreg from the stepped gold fingers. This ensures that even if the controlled-depth milling is too deep, the gold fingers will not be damaged. Furthermore, because the adhesive between the bonding substrate and the protective film loses its stickiness under the high temperature and pressure of the pressing process, the protective film can easily separate from the gold fingers, and adhesive residue is less likely to remain on the gold fingers. This reduces the possibility of gold finger contamination and improves the performance of the circuit board.

[0049] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are 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 now be described with reference to the accompanying drawings.

[0050] Figure 1 A flowchart illustrating the method for fabricating a stepped gold finger circuit board provided in this application is shown below. Figure 1 As shown, the method includes:

[0051] Step S101: Gold fingers are formed on at least one side of the substrate.

[0052] Specifically, gold fingers are made on one or both sides of the substrate by immersion gold or gold plating.

[0053] The substrate includes a substrate and copper foil bonded to at least one side of the substrate. That is, the substrate may include a substrate and copper foil bonded to one side of the substrate. The substrate may also include a substrate and copper foil bonded to both sides of the substrate respectively.

[0054] Gold fingers are formed on at least one side of the substrate, that is, gold fingers are formed on copper foil in the substrate.

[0055] Step S102: Use an adhesive material to bond the protective film to the substrate to cover the gold fingers.

[0056] The protective film, for example, is a PI film with a thickness greater than or equal to 0.05 mm. This protects the gold fingers and the area around them during subsequent removal of the prepreg and copper foil. Thus, even if a process malfunction causes an increase in removal height, the protective film is damaged first, not the gold fingers or the area around them, allowing time for machine repair and minimizing damage to the gold fingers and the area around them. The degradation temperature of the protective film is greater than or equal to a first preset temperature. The degradation pressure is greater than or equal to a preset pressure. The first preset temperature is, for example, 220 degrees Celsius. The preset pressure is, for example, 480 psi. This means the protective film will not degrade or rupture if the temperature is below the first preset temperature and the pressing pressure is less than 480 psi. This allows for the determination of the pressing temperature and pressure for the prepreg and copper foil based on the first preset temperature and preset pressure, ensuring that the prepreg and copper foil are pressed onto the side of the substrate with the protective film attached without causing the protective film to rupture.

[0057] Here, there is no limitation on the specific size of the protective film; the size of the protective film only needs to be within the range that can cover the size of the gold fingers to the total size of the substrate.

[0058] An adhesive material can be applied to the substrate around the gold fingers, and then a protective film can be bonded to the substrate to cover the gold fingers. In this way, even if the adhesive material still adheres to the substrate after lamination, it will not contaminate the gold fingers.

[0059] Alternatively, an adhesive substance can be applied to the perimeter or the entire area of ​​one side of the protective film, and then the protective film can be bonded to the substrate to achieve the purpose of using the adhesive substance to bond the protective film to the substrate and cover the gold fingers.

[0060] Adhesive substances are materials with adhesive or viscous properties used to bond two or more objects together. In this embodiment, the adhesive substance is used to bond the protective film to the substrate. Examples of adhesive substances include glue and adhesives.

[0061] The adhesive material is sticky in environments with temperatures below a second preset temperature, but loses its stickiness in environments with temperatures above or equal to the second preset temperature, which is lower than the first preset temperature. Therefore, in environments below the second preset temperature, the adhesive material can be used to bond the protective film and the substrate. In environments with temperatures above or equal to the second preset temperature, the bonded protective film and substrate can be peeled off. Thus, the temperature for pressing the prepreg and copper foil can be determined based on the second preset temperature, thereby achieving peeling of the protective film from the substrate while pressing the prepreg and copper foil onto the side of the substrate where the protective film is attached. Specifically, the second preset temperature is, for example, 125 degrees Celsius.

[0062] In step S103, the prepreg and copper foil are laminated on the side of the substrate where the protective film is attached. During the lamination process, the adhesive material loses its adhesiveness.

[0063] Prepreg is an important material in printed circuit board (PCB) manufacturing, typically used for interlayer bonding of multilayer PCBs. Prepreg is composed of resin-impregnated nonwoven or woven fabric, which cures under heat and pressure, thereby bonding the multilayer PCB together. In this embodiment, the prepreg is used for bonding copper foils to each other and between copper foils and a substrate.

[0064] Specifically, in this embodiment, the prepreg and copper foil can be laminated onto the side of the substrate with the protective film attached at a third preset temperature. The third preset temperature is lower than the first preset temperature and greater than or equal to the second preset temperature. Since the third preset temperature is lower than the first preset temperature, the protective film will not rupture during the lamination process of the prepreg and copper foil. Therefore, the prepreg located between the copper foil and the substrate will only adhere to the protective film and will not adhere to the gold fingers, thereby preventing the prepreg from contaminating the gold fingers. At the same time, since the third preset temperature is higher than the second preset temperature, and adhesive substances lose their adhesiveness in an environment with a temperature higher than the second preset temperature, using the third preset temperature to laminate the prepreg and copper foil not only laminates the prepreg and copper foil onto the side of the substrate with the protective film attached, but also allows the protective film to be separated from the substrate.

[0065] On one side of the substrate, there are at least two layers of prepreg and at least two layers of copper foil. The prepreg is placed between pairs of copper foils and between the copper foils and the substrate. By heating and pressurizing, the prepreg cures, thereby bonding the copper foils together and to the substrate.

[0066] Since the thickness of a single layer of copper foil is very low, if there is only one layer of copper foil on one side of the substrate, the depth of the stepped groove will be very low, and the stepped effect cannot be achieved. Therefore, the number of copper foil layers on one side of the substrate is limited to at least two layers to achieve the effect of forming a stepped groove.

[0067] Step S104: Remove part of the prepreg and part of the copper foil to form a stepped groove to expose the protective film.

[0068] The protective film is located within the stepped groove, with the shortest distance from the edge of the protective film to the groove wall being 0.01 mm to 0.02 mm. Since the protective film has already peeled off from the substrate during the lamination process of the prepreg and copper foil, removing a portion of the prepreg and copper foil creates the stepped groove. Because the shortest distance from the edge of the protective film to the groove wall is 0.01 mm to 0.02 mm, there is a gap between the edge of the protective film and the groove wall. This allows the protective film to be easily removed from the substrate, exposing the gold fingers and obtaining a stepped gold finger circuit board.

[0069] Specifically, the prepreg and copper foil can be milled in controlled depth to form stepped grooves.

[0070] Alternatively, the area where the copper foil and the protective film overlap vertically can be defined as the first region. The boundary position of the first region can be determined, and this boundary position can be expanded according to a preset increment to obtain the boundary position of the second region. The prepreg and copper foil are then milled with controlled depth along the boundary position of the second region until the substrate is exposed, forming a stepped groove. In this way, by only milling the prepreg and copper foil along the boundary position of the second region—that is, along the perimeter of the protective film—the overlapping area of ​​the prepreg and copper foil can be removed to form a stepped groove, without needing to mill the entire overlapping area. This speeds up the manufacturing of stepped grooves and allows for faster production of stepped gold finger circuit boards.

[0071] In some embodiments, the first region is, for example, a rectangle, and the boundary position of the first region includes the vertex coordinates of four vertices. The vertex coordinates of the four vertices of the first region are, for example, A(x1, y1), B(x2, y2), C(x3, y3), and D(x4, y4). The boundary position of the first region is expanded according to a preset increment. If the preset increment is d, then the vertex coordinates of the four vertices of the second region are: A'(x1 - d, y1 - d), B'(x2 + d, y2 - d), C'(x3 + d, y3 + d), and D'(x4 - d, y4 + d).

[0072] For example, if the first region is circular, then the boundary position of the first region includes the coordinates of the center and the radius. The center coordinates of the first region are, for example, O(x5, y6), and the radius of the first region is r1. The boundary position of the first region is expanded according to a preset increment. If the preset increment is d, then the center coordinates of the second region are O(x5, y6), and the radius of the second region is r2 = r1 + r1 / 2.

[0073] Step S105: Remove the protective film to obtain the stepped gold finger circuit board.

[0074] The method for manufacturing a stepped gold finger circuit board provided in this application involves bonding a protective film to a substrate to cover the gold fingers on the substrate. Then, a prepreg and copper foil are laminated and pressed together on the side of the substrate with the protective film attached. Since the adhesive between the protective film and the substrate loses its adhesiveness during the pressing process, when removing the protective film, the adhesive material may only adhere to a small amount or even not adhere to the gold fingers. Because the adhesive material loses its adhesiveness during the pressing process, the adhesiveness of the adhesive material will become very little or even non-existent after the pressing process. Therefore, even if a small amount of adhesive material adheres to the gold fingers, it can be easily removed from the gold fingers, thereby reducing the contamination of the gold fingers by the adhesive material and ensuring the performance of the stepped gold finger circuit board.

[0075] Referring to Figures 2(a) to 2(e), this embodiment provides a structural schematic diagram of a stepped gold finger fabricated on one side of a substrate using the above method. As shown in Figure 2(a), the substrate 6 includes a substrate 1 and a copper foil 2 bonded to one side of the substrate. Gold fingers 3 are fabricated on the side of the substrate 6 where the copper foil 2 is located by immersion gold or gold plating. The structural schematic diagram shown in Figure 2(a) is obtained. An adhesive material is coated around or entirely on one side of the protective film 4 to bond the protective film 4 to the side of the substrate 6 where the gold fingers 3 are fabricated, thereby covering the gold fingers 3, and the structural schematic diagram after the protective film is adhered is obtained as shown in Figure 2(b). Two layers of copper foil 2 and two layers of prepreg 5 are then laminated onto the side of the substrate 6 where the protective film 4 is attached, and the structural schematic diagram after lamination and lamination is obtained as shown in Figure 2(c). Then, the prepreg 5 and copper foil 2 laminated on the substrate 6 are deep-milled to expose the protective film 4, and the structural schematic diagram shown in Figure 2(d) is obtained. Finally, the protective film 4 is removed to obtain the structural schematic diagram of the single-sided stepped gold finger circuit board shown in Figure 2(e); the single-sided stepped gold finger circuit board is the stepped gold finger circuit board obtained by making stepped gold fingers on one side of the substrate.

[0076] Referring to Figures 3(a) to 3(e), this embodiment provides a schematic diagram of the steps for fabricating stepped gold fingers on both sides of a substrate using the above method. As shown in Figure 3(a), the substrate 6 includes a substrate 1 and copper foils 2 bonded to both sides of the substrate 1. Gold fingers 3 are fabricated on both sides of the substrate 6 by immersion gold or gold plating. The structural schematic diagram shown in Figure 3(a) is obtained. An adhesive material is coated on two protective films 4, and the two protective films 4 are bonded to one side of the substrate 6 to cover the gold fingers 3, resulting in the structural schematic diagram after the protective film is adhered, as shown in Figure 3(b). Then, two layers of copper foil 2 and two layers of prepreg 5 are laminated and pressed on the side of the substrate where the protective film 4 is attached, resulting in the structural schematic diagram after lamination and pressing, as shown in Figure 3(c). Then, the prepreg 5 and copper foil 2 pressed on both sides of the substrate 6 are partially removed until the protective film 4 on both sides of the substrate 6 is exposed, resulting in the structural schematic diagram shown in Figure 3(d). Finally, the protective films 4 on both sides of the substrate 6 are removed to obtain the structural schematic diagram of the double-sided stepped gold finger circuit board shown in Figure 3(e). The double-sided stepped gold finger circuit board is a stepped gold finger circuit board obtained by fabricating stepped gold fingers on both sides of the substrate.

[0077] The substrate material is, for example, epoxy glass fiber cloth-based copper clad laminate, polyimide, or ceramic.

[0078] Existing methods for fabricating stepped gold finger circuit boards involve pre-grooving the stepped gold finger area and placing spacers. The position and size of these grooves must be extremely precise, otherwise the quality and performance of the final product will be affected. Furthermore, the positioning of the spacers also requires extremely high precision; otherwise, inconsistent heights of the stepped gold fingers will result. However, the method for fabricating stepped gold finger circuit boards provided in this application eliminates the need for pre-grooving and placing spacers in the stepped gold finger area, thus reducing the difficulty of stepped gold finger production. Simultaneously, traditional grooving methods often require the use of a low-flow prepreg to ensure good adhesion between the spacer and the surrounding material, preventing delamination or air bubbles during subsequent processing. However, since the method for fabricating stepped gold finger circuit boards provided in this application does not require pre-grooving and placing spacers in the stepped gold finger area, the method does not have special requirements for the prepreg; that is, copper foil can be laminated onto the substrate without using a low-flow prepreg. Meanwhile, the method for manufacturing stepped gold finger circuit boards provided in this application does not require deep milling of the entire stepped gold finger area. Therefore, the high temperature and pressure of the lamination will cause the PI film attached to the stepped gold fingers to lose its adhesiveness. Thus, when performing deep milling on the copper foil and prepreg, only the perimeter of the PI film needs to be milled to easily remove unwanted copper foil and prepreg from the stepped gold fingers, resulting in a double-sided stepped gold finger printed circuit board. Even if the depth of the deep milling is too deep, it will not damage the gold fingers. In addition, since the adhesive on the bonding substrate and the protective film loses its adhesiveness under the high temperature and pressure of lamination, the protective film can easily separate from the gold fingers, and it is not easy for adhesive residue to remain on the gold fingers, thereby reducing the possibility of gold finger contamination and improving the performance of the circuit board.

[0079] In the description of the embodiments of this application, it should be understood that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, the connection of internal structures of two components, or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0080] The terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used 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. Therefore, they should not be construed as limitations on this application. In the description of this application, "multiple" means two or more, unless otherwise precisely specified.

[0081] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0082] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. 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.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to the structural or full structural technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for manufacturing a stepped gold finger circuit board, characterized in that, include: Gold fingers (3) are formed on at least one side of the substrate (6); A protective film (4) is adhered to the substrate (6) using an adhesive material to cover the gold fingers (3). On the side of the substrate (6) where the protective film (4) is attached, the prepreg (5) and the copper foil (2) are laminated and pressed together; wherein the adhesive material loses its adhesiveness during the pressing process; Remove part of the prepreg (5) and part of the copper foil (2) to form a stepped groove to expose the protective film (4). Remove the protective film (4) to obtain the stepped gold finger circuit board.

2. The method according to claim 1, characterized in that, The method of using an adhesive material to bond the protective film (4) to the substrate (6) to cover the gold finger (3) includes: The adhesive substance is coated on one side of the protective film (4); The protective film (4) with the adhesive substance coated on one side is attached to the side of the substrate (6) where the gold finger (3) is provided.

3. The method according to claim 1, characterized in that, include: The protective film (4) is located in the stepped groove, and the shortest distance from the boundary of the protective film (4) to the wall of the stepped groove is 0.01 mm to 0.02 mm.

4. The method according to claim 1, characterized in that, The thickness of the protective film (4) is greater than or equal to 0.05 mm.

5. The method according to claim 1, characterized in that, The degradation temperature of the protective film (4) is greater than or equal to the first preset temperature.

6. The method according to claim 5, characterized in that, The viscous substance is viscous in an environment with a temperature lower than the second preset temperature, and loses its viscousness in an environment with a temperature greater than or equal to the second preset temperature, wherein the second preset temperature is lower than the first preset temperature.

7. The method according to claim 6, characterized in that, On the side of the substrate (6) where the protective film (4) is attached, a prepreg (5) and a copper foil (2) are laminated together, including: The prepreg (5) and the copper foil (2) are laminated together on the side of the substrate (6) where the protective film (4) is attached, according to the third preset temperature. The third preset temperature is less than the first preset temperature and greater than or equal to the second preset temperature.

8. The method according to any one of claims 1 to 7, characterized in that, On the side of the substrate (6) where the protective film (4) is attached, a prepreg (5) and a copper foil (2) are laminated together, including: At least two layers of the copper foil (2) and two layers of the prepreg (5) are laminated and pressed onto the side of the substrate (6) where the protective film (4) is attached.

9. The method according to any one of claims 1 to 7, characterized in that, Removing a portion of the prepreg (5) and a portion of the copper foil (2) to form a stepped groove, including: Determine the boundary position of the first region; the first region is the area where the copper foil (2) and the protective film (4) overlap in the vertical direction; The boundary position of the first region is expanded according to a preset increment to obtain the boundary position of the second region; The prepreg (5) and copper foil (2) are milled at controlled depth along the boundary of the second region until the substrate (6) is exposed, forming a stepped groove.

10. A stepped gold finger circuit board, characterized in that, The stepped gold finger circuit board is manufactured by the method described in any one of claims 1 to 9.

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