Stepped electroformed steel mesh

Abstract

This utility model discloses a stepped electroformed steel mesh, comprising a mesh frame and a tensioned wire mesh. An edge ring electroformed mesh plate is tensioned onto the mesh frame via the tensioned wire mesh. The inner periphery of the edge ring electroformed mesh plate is bonded to the outer periphery of the middle ring electroformed mesh plate via a height difference connecting strip. The inner periphery of the middle ring electroformed mesh plate is bonded to the core electroformed mesh plate via another height difference connecting strip. Electroformed mesh holes are provided on the edge ring, middle ring, and core electroformed mesh plates. The middle ring electroformed mesh plate is located below the edge ring and core electroformed mesh plates. The height difference connecting strip is a strip-shaped connecting strip made of silicone or soft rubber. The thickness of the height difference connecting strip is greater than the thickness of the edge ring, middle ring, and core electroformed mesh plates. This electroformed steel mesh has the advantages of high precision and high hardness, and can effectively solve the problem of multiple printing on surfaces with different heights, making it particularly suitable for the fabrication of sensor chips.

Description

Technical Field

[0001] This utility model relates to packaging printing templates in the chip manufacturing process, and more particularly to a special template structure capable of printing with height differences. Background Technology

[0002] Integrated circuits (ICs), as core components of modern electronic devices, are widely used in communications, automobiles, industrial automation, and intelligent control, providing a solid guarantee for the miniaturization and high performance of electronic devices. In the chip manufacturing process, the packaging stencil is a high-precision printing tool used in ball grid array (BGA) packaging technology. Its main function is to accurately apply solder paste and precisely position the solder balls on the pads of the printed circuit board, avoiding bridging or cold solder joints. Traditional packaging stencils suffer from low aperture precision and rough hole walls, leading to uneven control of solder amount and solder ball position, easily resulting in cold solder joints and bridging problems, with a solder joint yield of less than 90%.

[0003] Depending on the function and application scenario, chips actually have different design structures. For example, control and sensor chips are used to detect environmental parameters such as temperature, light, pressure, and speed. Therefore, printed circuit boards have devices at different heights and positions for solder paste and solder balls to be printed. Current printing methods require customizing two or more printing templates with different heights for multiple printings, which greatly affects printing efficiency and the accurate application of solder paste. Utility Model Content

[0004] In view of the above-mentioned shortcomings of the existing technology, the technical problem to be solved by this utility model is to provide a stepped electroformed steel mesh, which not only has the advantages of high precision and high hardness, but also solves the problem of multiple printings required for surfaces of different heights.

[0005] To solve the above-mentioned technical problems, the present invention provides a stepped electroformed steel mesh, comprising a mesh frame and a tensioned wire mesh. An edge ring electroformed mesh plate is tensioned onto the mesh frame via the tensioned wire mesh. The inner periphery of the edge ring electroformed mesh plate is bonded to the outer periphery of the middle ring electroformed mesh plate via a height difference connecting strip. The inner periphery of the middle ring electroformed mesh plate is bonded to the core electroformed mesh plate via another height difference connecting strip. Electroformed mesh holes are provided on the edge ring electroformed mesh plate, the middle ring electroformed mesh plate, and the core electroformed mesh plate. The middle ring electroformed mesh plate is located below the edge ring electroformed mesh plate and the core electroformed mesh plate.

[0006] With the above structure, the use of electroformed metal mesh for the encapsulation template significantly increases the frequency of physical contact with the lithography machine due to its high mechanical strength, and also significantly improves the positional and dimensional accuracy of the mesh openings. Furthermore, the use of a height-difference connecting strip structure, which bonds the edge ring, middle ring, and core electroformed mesh together, allows these meshes to be positioned at different heights, forming a stepped structure. This solves the problem of requiring multiple printing passes at different heights, greatly improving printing efficiency and reducing production costs. The height-difference connecting strip structure also allows for stable and uniform tension of the printing mesh, facilitating precise solder paste application and accurate solder ball placement.

[0007] Furthermore, the edge ring electroformed stencil and the middle ring electroformed stencil are rectangular ring-shaped metal sheets, while the core electroformed stencil is a rectangular metal sheet. The edge ring electroformed stencil, the middle ring electroformed stencil, and the core electroformed stencil are electroformed nickel plates. The use of rectangular rings and rectangular sheets ensures balanced tension on the printing stencil; the electroformed nickel plate has the advantages of high mechanical strength and corrosion resistance, significantly improving the service life of the printing template.

[0008] Furthermore, the elevation difference connecting strip is a strip-shaped connecting strip made of silicone or soft rubber. The elevation difference connecting strip, made of silicone or soft rubber, has the advantages of high elasticity and good tensile strength and tear resistance.

[0009] Furthermore, the thickness of the height difference connecting strip is greater than the thickness of the edge ring electroformed mesh plate, the middle ring electroformed mesh plate, and the core electroformed mesh plate. This not only ensures sufficient tensile strength for the steel mesh plate but also facilitates the adjustment of the height difference between the steel mesh plate surfaces.

[0010] Furthermore, the surfaces of the edge ring electroformed stencil, the middle ring electroformed stencil, and the core electroformed stencil are covered with a polymer film layer, the mesh positions of which correspond to the electroformed mesh positions of the edge ring electroformed stencil, the middle ring electroformed stencil, and the core electroformed stencil. Covering the surface of the electroformed stencil with a polymer film layer not only protects the electroformed substrate but also allows for the precise implantation of solder balls of different diameters and sizes. Attached Figure Description

[0011] The stepped electroformed steel mesh of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0012] Figure 1 This is a cross-sectional structural schematic diagram of a specific embodiment of the stepped electroformed steel mesh of this utility model;

[0013] Figure 2 yes Figure 1 A top-down view of the structure.

[0014] In the diagram, 1—mesh frame, 2—tensioned wire mesh, 3—edge ring electroformed mesh plate, 4—middle ring electroformed mesh plate, 5—elevation difference connecting strip, 6—core electroformed mesh plate, 7—electroformed mesh holes, 8—electroformed mold holes. Detailed Implementation

[0015] like Figure 1 , Figure 2 The stepped electroformed steel mesh shown is a specialized printing template used in sensor chip fabrication. It comprises a frame 1 and a tensioned wire mesh 2. The frame 1 is a rectangular frame made of aluminum alloy, and the tensioned wire mesh 2 is a U-shaped polyester wire mesh. Within the frame 1 are edge ring electroformed steel mesh plates 3, middle ring electroformed steel mesh plates 4, and core electroformed steel mesh plates 6. The edge ring electroformed steel mesh plates 3 and 4 are both rectangular U-shaped thin metal sheet structures, while the core electroformed steel mesh plate 6 is a rectangular thin metal sheet located within the rectangular frame of the middle ring electroformed steel mesh plate 4, which in turn is located within the rectangular frame of the edge ring electroformed steel mesh plate 3. The edge ring electroformed steel mesh plates 3, 4, and 6 are all electroformed nickel meshes manufactured using an electroforming process.

[0016] The outer periphery of the tensioned wire mesh 2 is glued to the bottom edge of the frame 1. The inner periphery of the tensioned wire mesh 2 is glued to the outer periphery of the edge ring electroformed wire mesh 3. The inner periphery of the edge ring electroformed wire mesh 3 is glued to the upper surface of the corresponding height difference connecting strip 5. The outer periphery of the middle ring electroformed wire mesh 4 is glued to the lower surface of the aforementioned height difference connecting strip 5. The inner periphery of the middle ring electroformed wire mesh 4 is glued to the lower surface of another height difference connecting strip 5. The core electroformed wire mesh 6 is glued to the upper surface of this height difference connecting strip 5, thereby creating a height difference between the edge ring electroformed wire mesh 3, the middle ring electroformed wire mesh 4, and the core electroformed wire mesh 6. By changing and adjusting the thickness of the height difference connecting strip 5, different wire mesh height differences can be obtained to meet the manufacturing requirements of chips for different applications.

[0017] Electroforming mesh 7 and electroforming mold hole 8 are provided on the edge ring electroforming mesh plate 3, the middle ring electroforming mesh plate 4 and the core electroforming mesh plate 6. The electroforming mesh 7 is used to insert solder balls, and the electroforming mold hole 8 is used to insert corresponding electronic components.

[0018] The height difference connecting strip 5 is a U-shaped strip made of soft rubber. Of course, the height difference connecting strip 5 can also be made of silicone. Furthermore, the thickness of the height difference connecting strip 5 is greater than the thickness of the edge ring electroformed mesh plate 3, the middle ring electroformed mesh plate 4, and the core electroformed mesh plate 6. Preferably, the thickness of the height difference connecting strip 5 is (2-6) times that of the edge ring electroformed mesh plate 3, the middle ring electroformed mesh plate 4, or the core electroformed mesh plate 6.

[0019] Another preferred embodiment differs from the above embodiments in that: the upper or lower surfaces of the edge ring electroforming stencil 3, the middle ring electroforming stencil 4, and the core electroforming stencil 6 are covered with a polymer film layer, such as a commonly used PI film. This polymer film layer also has mesh holes, which correspond to and match the positions of the electroforming mesh holes 7 on the electroforming stencil. Covering the electroforming stencil with a film layer not only effectively reduces the thickness of the electroforming substrate and lowers the cost of the printed packaging stencil, but also allows for the insertion of solder balls with different diameters by adjusting and replacing the two side film layers with different thicknesses, thereby increasing the applicability of the stencil. Covering the electroforming substrate with a film layer also provides effective protection for the electroforming substrate, extends its service life, and enhances the stencil's resistance to photolithography etching solution erosion and high-frequency use losses.

[0020] The preferred exemplary embodiments of the present invention have been described above by way of illustration only. However, those skilled in the art can make various modifications and improvements to the described embodiments without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A stepped electroformed steel mesh, comprising a mesh frame (1) and a tensioned wire mesh (2), characterized in that: The frame (1) is tensioned with a side ring electroformed mesh plate (3) by a tensioning wire mesh (2). The inner periphery of the side ring electroformed mesh plate (3) is bonded to the outer periphery of the middle ring electroformed mesh plate (4) by a height difference connecting strip (5). The inner periphery of the middle ring electroformed mesh plate (4) is bonded to the core electroformed mesh plate (6) by another height difference connecting strip (5). Electroformed mesh holes (7) are provided on the side ring electroformed mesh plate (3), the middle ring electroformed mesh plate (4) and the core electroformed mesh plate (6). The middle ring electroformed mesh plate (4) is located below the side ring electroformed mesh plate (3) and the core electroformed mesh plate (6).

2. The stepped electroformed steel mesh according to claim 1, characterized in that: The edge ring electroformed mesh plate (3) and the middle ring electroformed mesh plate (4) are rectangular ring-shaped metal sheets, and the core electroformed mesh plate (6) is a rectangular metal sheet.

3. The stepped electroformed steel mesh according to claim 1 or 2, characterized in that: The edge ring electroformed mesh plate (3), the middle ring electroformed mesh plate (4) and the core electroformed mesh plate (6) are electroformed nickel plates.

4. The stepped electroformed steel mesh according to claim 1, characterized in that: The elevation difference connecting strip (5) is a strip-shaped connecting strip made of silicone or soft rubber.

5. The stepped electroformed steel mesh according to claim 1 or 4, characterized in that: The thickness of the height difference connecting strip (5) is greater than the thickness of the edge ring electroformed mesh plate (3), the middle ring electroformed mesh plate (4) and the core electroformed mesh plate (6).

6. The stepped electroformed steel mesh according to claim 1, characterized in that: The surfaces of the edge ring electroformed mesh plate (3), the middle ring electroformed mesh plate (4) and the core electroformed mesh plate (6) are covered with a polymer film layer, and the mesh positions on the polymer film layer correspond to the electroformed mesh positions (7) of the edge ring electroformed mesh plate (3), the middle ring electroformed mesh plate (4) and the core electroformed mesh plate (6).

7. The stepped electroformed steel mesh according to claim 1, characterized in that: The frame (1) is an aluminum alloy rectangular frame, and the tensioned wire mesh (2) is a polyester wire mesh.

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