A keyboard FR4 material positioning plate structure

Abstract

This application relates to the field of keyboard structure technology, specifically a keyboard FR4 material positioning plate structure, including: an FR4 material positioning plate with screw post mounting positions; a solder pad located at the screw post mounting positions, the solder pad being integrally formed with the FR4 material positioning plate; and a screw post, which is fixed to the solder pad by welding from the bottom. The bottom welding surface of the screw post has a pre-plated tin layer and a micro-hole array, which allows solder to penetrate into the micro-hole array during welding to form a mechanical anchoring structure. This application uses an FR4 material positioning plate combined with a welded screw post to form a gapless connection structure, which can effectively reduce vibration dispersion caused by material deformation or screw post loosening, making the key press sound more concentrated. This solves the problem of dispersed key press sound in the prior art, better meeting the sound quality requirements of high-end customized keyboards and satisfying consumers' diverse keyboard needs.

Description

Technical Field

[0001] This application relates to the field of keyboard structure technology, and in particular to a keyboard FR4 material positioning plate structure. Background Technology

[0002] The keyboard mounting plate is a core load-bearing component in the keyboard structure. Its main function is to provide a mounting reference for the switches and transmit the pressing force, directly affecting the keyboard's feel, sound, and overall structural stability. In current technology, the choice of mounting plate material and the method of fixing the screw posts are two key technical directions: common mounting plate materials include aluminum alloy and PC (polycarbonate). Aluminum alloy mounting plates are widely used due to their ease of processing, and their screw posts are mostly fixed by riveting, that is, pressing the screw posts into the pre-set riveting holes of the mounting plate through mechanical pressure, utilizing the plastic deformation of the material to achieve a fastening. PC material mounting plates, on the other hand, often use an injection molding process to form a one-piece structure with the screw posts, simplifying the assembly process. These technical solutions have mature applications in different types of keyboard products and constitute the mainstream implementation of current keyboard mounting plate structures.

[0003] However, existing technologies still have the following limitations: using riveting or injection-molded screws to fix the positioning plate to the PCB results in a scattered sound when the keyboard switches are inserted, and there is a risk of poor anodizing or increased deformation of the positioning plate, making it difficult to meet the requirements of high-end custom keyboards. This project aims to develop a keyboard positioning plate structure made of FR4 material to solve these problems. Utility Model Content

[0004] In view of at least one of the above technical problems, this application provides a keyboard FR4 material positioning plate structure, which solves the problem by adopting the following technical solution.

[0005] According to one aspect of this application, a keyboard FR4 material positioning plate structure is provided, comprising:

[0006] The FR4 material positioning plate has screw post mounting positions on it;

[0007] The pads are located at the screw post mounting positions and are integrally formed with the FR4 material positioning plate.

[0008] The screw post is fixed to the pad by welding from the bottom.

[0009] Preferably, the bottom welding surface of the screw post is provided with a pre-plated tin layer.

[0010] Preferably, the bottom welding surface of the screw post is provided with a micropore array, which is used for the solder to penetrate into the micropore array during welding to form a mechanical anchoring structure.

[0011] Preferably, the bottom welding surface of the screw post is provided with a concentric annular groove, and during welding, the molten solder fills the concentric annular groove to form a mechanical interlocking structure.

[0012] Preferably, the screw post mounting area of ​​the FR4 material positioning plate is provided with a reinforcing rib structure, and the reinforcing ribs are distributed radially around the solder pad.

[0013] Preferably, a reinforcing bonding layer is provided between the solder pads and the FR4 material positioning plate.

[0014] Preferably, the pad has a stepped composite structure, including a lower bonding layer that bonds to the FR4 material positioning plate and an upper thickened layer facing the screw post.

[0015] Preferably, the edge of the upper thickened layer extends to form an annular flange, and the welding surface of the screw post covers the annular flange.

[0016] Preferably, a thermal isolation groove is provided around the pad, and the thermal isolation groove is arranged around the outer edge of the pad.

[0017] Preferably, there is an eccentricity between the axial centerline of the screw post and the center of the pad, and the eccentricity direction of the axial centerline of the screw post is opposite to the direction of the stress concentration area of ​​the FR4 material positioning plate.

[0018] This application has the following technical effects:

[0019] This application uses an FR4 material positioning plate with high rigidity and low damping characteristics. Combined with the welded and fixed screw posts to form a gapless connection structure, it can effectively reduce the vibration dispersion caused by material deformation or loose screw posts, making the key press sound more concentrated. This solves the problem of dispersed key press sound in the prior art, improves the acoustic experience of the keyboard, and better meets the sound quality requirements of high-end customized keyboards. Through the structure of this patented application, it can meet the diverse needs of consumers for keyboards. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a front view of this application;

[0022] Figure 2 This is a diagram of the pad structure in this application;

[0023] Figure 3 This is a perspective view from this application.

[0024] Figure label:

[0025] 1. FR4 material positioning plate; 2. Solder pads; 3. Shaft mounting holes; 4. Screw posts. Detailed Implementation

[0026] Please see Figures 1 to 3 It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the technical terms used in this specification are merely for clarity and are not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0027] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings. Numerous specific details are set forth in the following description to provide a thorough understanding of this application.

[0028] In this embodiment of the application, as Figures 1-3 As shown, a keyboard FR4 material positioning plate structure is provided, including:

[0029] The FR4 material positioning plate 1 has screw post mounting positions and shaft mounting holes 3.

[0030] The solder pad 2 is located at the screw post mounting position and is integrally formed with the FR4 material positioning plate 1.

[0031] Screw post 4 is fixed to pad 2 by welding at the bottom.

[0032] It should be noted that, in order to solve the problems of easy deformation of existing aluminum alloy positioning plates due to riveting and easy loosening of PC positioning plates due to injection molding, and to meet the market's demand for diverse positioning plate materials, this application's structure includes an FR4 material positioning plate 1, a solder pad 2 integrally formed with the positioning plate 1, and a screw post 4 fixed to the solder pad 2 by bottom welding. The positioning plate 1 also has a shaft mounting hole 3. This design can achieve multiple effects: the high rigidity of FR4 material (elastic modulus ≥18GPa) can reduce the deformation of the positioning plate; the integrally formed solder pad 2 can ensure uniform heat conduction during welding; and the welding fixing method, compared with riveting or injection molding, can avoid connection failure caused by mechanical stress or air bubbles, making the sound of pressing the shaft more concentrated (frequency fluctuation within ±20Hz). The principle behind this is that the rigidity of the FR4 material itself provides stable support for the overall structure; the solder pad 2, as a welding intermediary, not only ensures a firm connection with the positioning plate 1, but also provides a reliable welding base for the screw post 4; and the fusion effect during the welding process can form a gapless connection, reducing vibration dispersion. In practice, the shaft mounting hole 3 is first punched out on the FR4 plate, then the pad 2 and the positioning plate 1 are integrally formed by pressing and etching process, and finally the bottom of the screw post 4 is fixed to the pad 2 by laser welding.

[0033] In one embodiment of this application, the bottom welding surface of the screw post 4 is provided with a pre-plated tin layer.

[0034] It should be noted that the above design addresses the problem of insufficient solder wettability leading to cold solder joints during the welding process. The tin layer reduces the surface tension of the welding surface, making it easier for molten solder to diffuse between the bottom of the screw post 4 and the pad 2, thereby improving the uniformity and strength of the weld. In practice, the pre-plated tin layer can increase the weld strength to over 60N (tensile test), far exceeding the 30-40N of existing PC injection molded screw posts. The principle is that tin has a low melting point (approximately 232℃), which allows it to melt rapidly at the high temperature of laser welding and form an alloy layer with the copper foil of the pad 2, enhancing the interfacial bonding force. In specific implementation, a uniform tin layer with a thickness of 5-10μm is formed on the bottom welding surface of the screw post 4 through an electrolytic tin plating process, ensuring that the tin layer reacts fully with the copper foil of the pad 2 during welding, avoiding solder accumulation or missed solder joints.

[0035] In one embodiment of this application, the bottom welding surface of the screw post 4 is provided with a micropore array, which is used for the solder to penetrate into the micropore array during welding to form a mechanical anchoring structure.

[0036] It should be noted that mechanical interlocking enhances the connection between the screw post 4 and the pad 2, preventing detachment due to insufficient bonding force at the welding interface alone. During welding, molten solder penetrates the micropore array and solidifies, forming an anchor-like structure. This upgrades the connection strength from a simple chemical bond to a chemical bond plus mechanical interlocking, significantly improving torsional and tensile strength. This structure also enhances the shear resistance of the screw post 4. The principle is that the micropore array increases the specific surface area of ​​the welding surface, and the solidified solder physically interlocks with the micropores, reducing the possibility of the screw post 4 sliding along the welding surface. Specifically, micropores with a diameter of 0.1-0.3 mm and a depth of 0.2-0.4 mm are machined at the bottom of the screw post 4 by laser drilling or chemical etching. The micropores are distributed in an array to ensure uniform stress distribution, and the solder naturally fills the micropores during welding to complete the anchoring.

[0037] In one embodiment of this application, the bottom welding surface of the screw post 4 is provided with a concentric annular groove, and during welding, the molten solder fills the concentric annular groove to form a mechanical interlocking structure.

[0038] It should be noted that, to further enhance the mechanical interlocking effect after welding, especially addressing the potential loosening of the screw post 4 due to vibration during long-term use, the molten solder fills and solidifies the groove during welding, forming an annular protrusion that matches the groove. This structure acts like a clamp, tightly locking the screw post 4 to the pad 2, improving shear and torsional resistance. The principle is that the annular groove adds a concave-convex structure to the welding surface, changing the connection between the screw post 4 and the pad 2 from planar contact to a three-dimensional interlocking, thus dispersing localized stress. Specifically, this can be achieved by machining on a lathe or laser engraving concentric annular grooves with a depth of 0.1-0.3 mm and a width of 0.2-0.5 mm at the bottom of the screw post 4. The number of grooves can be multiple rings depending on the diameter of the screw post 4, ensuring a continuous annular interlocking structure after the solder fills the groove.

[0039] In one embodiment of this application, the screw post mounting area of ​​the FR4 material positioning plate 1 is provided with a reinforcing rib structure, and the reinforcing ribs are radially distributed around the solder pad 2.

[0040] It should be noted that, regarding the deformation of the positioning plate caused by localized heating during welding and stress concentration during long-term use, the radial reinforcing ribs can increase the rigidity of the FR4 material positioning plate 1 at the screw post mounting position by increasing the local thickness, reducing warping caused by welding heat, and dispersing the stress transmitted to the screw post 4 when the shaft is pressed, ensuring the flatness of the shaft installation. The principle is that the radial structure can distribute stress along multiple directions to the entire positioning plate 1, avoiding deformation caused by excessive localized stress. Specifically, on the back of the screw post mounting position of the FR4 material positioning plate 1, ribs radiating outward from the edge of the solder pad 2 are formed through etching or injection molding processes. For example, the rib width is 0.5-1mm and the height is 0.3-0.5mm, integrally molded with the positioning plate 1.

[0041] In one embodiment of this application, a reinforcing bonding layer is provided between the solder pad 2 and the FR4 material positioning plate 1, and the reinforcing bonding layer is a glass fiber woven mesh embedded layer.

[0042] It should be noted that this design addresses potential peeling issues between pad 2 and FR4 due to material differences. FR4 is an epoxy resin substrate, while pad 2 is primarily copper foil, resulting in weak interfacial bonding. The embedded fiberglass mesh layer, with its three-dimensional mesh structure, provides mechanical anchoring, increasing the bonding area and interlocking force between pad 2 and positioning plate 1. In practice, this structure enhances the peel strength of pad 2, exceeding that without a reinforcement layer. The principle is that the mesh openings of the fiberglass mesh allow the FR4 substrate to penetrate and solidify during molding, forming a composite structure similar to reinforced concrete, thus strengthening the interfacial connection. Specifically, during FR4 lamination, a 60-100 mesh fiberglass mesh is pre-embedded in the corresponding area of ​​pad 2, and then copper foil pad 2 is formed through etching, allowing the mesh to bond simultaneously to both the FR4 substrate and pad 2.

[0043] In one embodiment of this application, the pad 2 has a stepped composite structure, including a lower bonding layer that is bonded to the FR4 material positioning plate 1 and an upper thickened layer facing the screw post 4.

[0044] It should be noted that the purpose of the above structure is to balance the bonding strength between the solder pad 2 and the FR4 material positioning plate 1, as well as the heat-bearing capacity during welding. The lower bonding layer is thinner, allowing for a tight bond with the positioning plate 1 through etching, avoiding weak bonding caused by excessive thickness; the upper thicker layer provides sufficient conductive and thermally conductive material for welding, reducing thermal deformation during welding. This design ensures that the solder pad 2 is not easily peeled off from the positioning plate 1, while also guaranteeing the stability of the screw post 4 welding. The principle is that the layered structure optimizes the bonding strength and welding performance respectively: the thin lower bonding layer reduces the difference in thermal expansion with FR4, while the thick upper thicker layer improves the heat distribution efficiency during welding. In specific implementation, the solder pad 2 is processed through two electroplating or etching processes. First, a lower bonding layer (copper layer) is formed to bond with the positioning plate 1, and then an upper thicker layer (copper layer) facing the screw post 4 is processed on top of it, forming a stepped structure.

[0045] In one embodiment of this application, the edge of the upper thickened layer extends to form an annular flange, and the welding surface of the screw post 4 covers the annular flange.

[0046] It should be noted that the design of extending the edge of the upper thickened layer to form an annular flange, with the welding surface of the screw post 4 covering the flange, is primarily to improve the positioning accuracy and weld strength. The annular flange provides a physical positioning reference for the screw post 4, preventing it from shifting during welding. Simultaneously, the flange increases the peripheral contact area of ​​the weld, allowing welding stress to be more evenly distributed between the pad 2 and the positioning plate 1. In effect, this structure can control the welding offset of the screw post 4 within a smaller range and improve the tensile strength of the weld. The principle is that the "step" formed by the annular flange restricts the radial movement of the screw post 4, while the increased contact area reduces the stress load per unit area. Specifically, during the processing of the upper thickened layer of the pad 2, for example, an etching process is used to extend its edge outward by 0.2-0.3 mm to form an annular flange. The flange height is consistent with the upper thickened layer, and the diameter of the bottom welding surface of the screw post 4 is slightly larger than the outer diameter of the flange, ensuring complete coverage of the flange during welding.

[0047] In one embodiment of this application, a thermal isolation groove is provided around the pad 2, and the thermal isolation groove is arranged around the outer edge of the pad 2.

[0048] It should be noted that, to reduce the impact of high temperatures during welding on the FR4 material positioning plate 1, although FR4 material has a temperature resistance of ≥130℃, localized high temperatures can still cause carbonization or delamination of its epoxy resin substrate. The thermal isolation groove can block heat conduction to other areas of the positioning plate 1 through air gaps, reducing the heat-affected zone. This structure can lower the temperature of FR4 outside the welding area, preventing warping of the positioning plate 1. The principle is that the thermal conductivity of air inside the thermal isolation groove is much lower than that of FR4, forming a thermal barrier so that the heat generated during welding is mainly concentrated in the areas of the solder pad 2 and the screw post 4. Specifically, an annular thermal isolation groove is processed on the outer edge of the solder pad 2 using laser cutting. For example, the groove width is 0.5-1mm, the depth is 1 / 3-1 / 2 of the thickness of the positioning plate 1, and the distance between the groove and the edge of the solder pad 2 is 0.3-0.5mm, ensuring that heat is isolated without affecting the stability of the solder pad 2.

[0049] In one embodiment of this application, the axial centerline of the screw post 4 is offset from the center of the pad 2, and the offset direction of the axial centerline of the screw post 4 is opposite to the direction of the stress concentration area of ​​the FR4 material positioning plate 1.

[0050] It should be noted that the purpose of the above structure is to counteract the stress concentration of the positioning plate 1 through mechanical optimization, thereby improving the fatigue resistance of the overall structure. During keyboard use, the edges or corners of the FR4 material positioning plate 1 are prone to stress concentration due to the pressure of the switch. If the screw post 4 is centrally located, it may exacerbate local deformation; however, the eccentrically positioned screw post 4 can generate a reverse torque, balancing the stress distribution. This structure can control the long-term deformation rate of the FR4 material positioning plate 1 within a lower range, extending its service life. The principle is that the eccentric setting utilizes the asymmetrical connection between the screw post 4 and the pad 2 to guide some of the stress to the low-stress area of ​​the FR4 material positioning plate 1, achieving overall force balance. In specific implementation, for example, the stress concentration area of ​​the FR4 material positioning plate 1 (such as the mounting position near the frame) is first determined through finite element analysis, and then the axial centerline of the screw post 4 is offset in the opposite direction of the stress concentration area by 0.1-0.5mm to ensure that the eccentricity matches the stress magnitude.

[0051] The above are merely preferred embodiments of this application and do not constitute any limitation on this application. Any person skilled in the art can make many possible variations and modifications to the technical solution of this application, or modify it into equivalent embodiments, without departing from the scope of the technical solution of this application. Therefore, all equivalent changes made based on the shape, structure, and principle of this application without departing from the content of the technical solution of this application should be covered within the protection scope of this application.

Claims

1. A keyboard FR4 material positioning plate structure, characterized in that, include: FR4 material positioning plate (1), which has screw post mounting positions; The pad (2) is provided at the screw post mounting position, and the pad (2) is integrally formed with the FR4 material positioning plate (1); Screw post (4), which is fixed to the pad (2) by welding at the bottom.

2. The keyboard FR4 material positioning plate structure according to claim 1, characterized in that: The bottom welding surface of the screw post (4) is provided with a pre-plated tin layer.

3. The keyboard FR4 material positioning plate structure according to claim 1, characterized in that: The bottom welding surface of the screw post (4) is provided with a micro-hole array, which is used for the solder to penetrate into the micro-hole array during welding to form a mechanical anchoring structure.

4. The keyboard FR4 material positioning plate structure according to claim 1, characterized in that: The bottom welding surface of the screw post (4) is provided with a concentric annular groove. During welding, the molten solder fills the concentric annular groove to form a mechanical interlocking structure.

5. The keyboard FR4 material positioning plate structure according to claim 1, characterized in that: The screw post mounting area of ​​the FR4 material positioning plate (1) is provided with a reinforcing rib structure, and the reinforcing ribs are radially distributed around the solder pad (2).

6. The keyboard FR4 material locating plate structure according to claim 1, characterized in that: An enhanced bonding layer is provided between the solder pad (2) and the FR4 material positioning plate (1).

7. The keyboard FR4 material locating plate structure according to claim 1, characterized in that: The pad (2) has a stepped composite structure, including a lower bonding layer that is bonded to the FR4 material positioning plate (1) and an upper thickened layer facing the screw post (4).

8. The keyboard FR4 material positioning plate structure according to claim 7, characterized in that: The edge of the upper thickened layer extends to form an annular flange, and the welding surface of the screw post (4) covers the annular flange.

9. The keyboard FR4 material positioning plate structure according to claim 1, characterized in that: The pad (2) is provided with a thermal isolation groove around its periphery, and the thermal isolation groove is arranged around the outer edge of the pad (2).

10. The keyboard FR4 material positioning plate structure according to claim 1, characterized in that: The axial centerline of the screw post (4) is offset from the center of the pad (2), and the eccentric direction of the axial centerline of the screw post (4) is opposite to the direction of the stress concentration area of ​​the FR4 material positioning plate (1).

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