A circuit board printing steel mesh demolding structure capable of preventing tin paste adhesion

Abstract

This utility model discloses a circuit board stencil release structure to prevent solder paste adhesion, comprising a stencil body and a mounting frame connected to the periphery of the stencil body. Its key feature is the inclusion of a multi-stage buffer release mechanism, which consists of a flexible support layer disposed between the stencil body and the circuit board, and micro-vibration release-promoting components distributed around the mesh openings of the stencil body. During release, the flexible support layer provides a gradual separation force through a deformation gradient, while the micro-vibration release-promoting components apply micro-vibrations at the moment of release. This utility model, through the combination of the gradual separation of the flexible support layer and the vibration of the micro-vibration release-promoting components, ensures that the solder paste smoothly detaches from the stencil during release, preventing adhesion and guaranteeing stable printing.

Description

Technical Field

[0001] This utility model belongs to the field of stencil release technology for circuit board solder paste printing, and particularly relates to a stencil release structure for circuit board printing that prevents solder paste adhesion. Background Technology

[0002] In the solder paste printing process of circuit boards, the adhesion and banding effect during stencil demolding is one of the main causes of printing defects. When traditional stencils are demolded, the strong adhesion between the solder paste and the sidewalls of the stencil openings easily leads to problems such as solder paste spikes, residues, or insufficient transfer, affecting the soldering quality. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the shortcomings of the existing technology, this utility model provides a circuit board printing stencil demolding structure that prevents solder paste adhesion. By combining the gradual separation of the flexible support layer with the vibration of the micro-vibration demolding component, the solder paste can be smoothly removed from the stencil without adhesion during demolding, thus ensuring stable printing.

[0004] Technical Solution: To achieve the above objectives, this utility model provides a circuit board stencil release structure for preventing solder paste adhesion, comprising a stencil body and an installation frame connected to the periphery of the stencil body, and further comprising a multi-stage buffer release mechanism. This multi-stage buffer release mechanism consists of a flexible support layer disposed between the stencil body and the circuit board, and micro-vibration release-promoting components distributed around the mesh openings of the stencil body. The flexible support layer provides a progressive separation force through a deformation gradient during release, and the micro-vibration release-promoting components apply micro-vibration at the moment of release.

[0005] Furthermore, the flexible support layer is evenly distributed on the bottom surface of the steel mesh body, avoiding the mesh openings.

[0006] Furthermore, the bottom surface of the steel mesh body is provided with a support layer mounting groove corresponding to the flexible support layer; the flexible support layer protrudes from the support layer mounting groove under normal conditions, and can be gradually compressed and embedded into the support layer mounting groove during printing pressure, and the lower surface of the steel mesh body contacts the solder pads of the circuit board.

[0007] Furthermore, the flexible support layer includes a high-hardness layer and a low-hardness layer stacked on top of each other to provide a progressive separation force through the material deformation gradient during demolding.

[0008] Furthermore, a vibration component mounting groove is provided on the bottom surface of the steel mesh body, and the micro-vibration detachment facilitator is embedded in the vibration component mounting groove.

[0009] Furthermore, the micro-vibration detachment facilitator includes a piezoelectric ceramic sheet and a vibration transmission rod, with a flexible conductive paste filling the space between the piezoelectric ceramic sheet and the vibration transmission rod, and the vibration transmission rod extending along the thickness direction of the steel mesh body.

[0010] Furthermore, the end of the vibration transmission rod is tapered.

[0011] Furthermore, the vibration transmission rod is inclined, wherein the axis forms an acute angle α with the sidewall of the mesh pointed to by the conical end.

[0012] Beneficial effects: The flexible support layer of this utility model provides a progressive separation force through deformation gradient during demolding, avoiding solder paste stretching and breakage caused by instantaneous separation of the stencil and the circuit board, reducing solder paste spikes and residues. The micro-vibration demolding component applies micro-vibration at the moment of demolding, effectively destroying the adhesion between the solder paste and the mesh sidewall of the stencil, ensuring that the solder paste completely detaches from the stencil and stably adheres to the pads of the circuit board. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0014] Figure 2 for Figure 1 A magnified schematic diagram of the structure of region A in the middle. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings.

[0016] like Figure 1 and Figure 2 As shown, a circuit board stencil release structure for preventing solder paste adhesion includes a stencil body 1 and a mounting frame 2 connected to the periphery of the stencil body 1. It also includes a multi-stage buffer release mechanism, which consists of a flexible support layer 4 disposed between the stencil body 1 and the circuit board 3, and micro-vibration release components 5 distributed around the mesh openings 10 of the stencil body 1. The flexible support layer 4 provides a gradual separation force through deformation gradient during release, preventing solder paste stretching and breakage caused by instantaneous separation of the stencil and the circuit board, reducing solder paste spikes and residue. The micro-vibration release components 5 apply micro-vibration at the moment of release, effectively disrupting the adhesion between the solder paste and the sidewalls of the mesh openings 10 of the stencil, ensuring the solder paste completely detaches from the stencil and stably adheres to the pads of the circuit board. Therefore, this invention, through the combination of the gradual separation of the flexible support layer 4 and the vibration of the micro-vibration release components 5, prevents solder paste adhesion during release and ensures stable printing.

[0017] It should be noted that the flexible support layer 4 is evenly distributed on the bottom surface of the stencil body 1, avoiding the mesh openings 10. Moreover, the flexible support layer 4 only covers the non-opening areas of the stencil, avoiding the squeezing of solder paste during the printing process, ensuring the precise shape of the solder paste, and maintaining the overall support stability of the stencil.

[0018] The bottom surface of the stencil body 1 has a support layer mounting groove 11 corresponding to the flexible support layer 4. Under normal conditions, the flexible support layer 4 protrudes from the support layer mounting groove 11 and can be gradually compressed and embedded into the support layer mounting groove 11 during printing pressure. The lower surface of the stencil body 1 contacts the pads of the circuit board 3. The support layer mounting groove 11 provides compression space for the flexible support layer 4. During printing pressure, the flexible support layer 4 is compressed and embedded into the groove, allowing the lower surface of the stencil body 1 to directly contact the pads of the circuit board 3, ensuring uniform printing pressure distribution and avoiding localized incomplete printing or overpressure.

[0019] like Figure 2 As shown, the flexible support layer 4 includes a high-hardness layer 41 and a low-hardness layer 42 stacked on top of each other to provide a gradual separation force through material deformation gradient during demolding. The high-hardness layer 41 provides initial support force, while the low-hardness layer 42 gradually rebounds during demolding, forming a separation force change from strong to weak, i.e., a non-linear separation force. This prevents the solder paste from being suddenly pulled, allowing it to detach smoothly from the stencil and avoiding structural damage caused by sudden separation.

[0020] The ratio of the elastic modulus of the high-hardness layer 41 to the low-hardness layer 42 is 1.5 to 3.0. The high-hardness layer 41 can be made of polyurethane, and the low-hardness layer 42 can be made of silicone rubber.

[0021] like Figure 1 and Figure 2 As shown, the bottom surface of the steel mesh body 1 is provided with a vibration component mounting groove 12. The micro-vibration detachment component 5 is embedded in the vibration component mounting groove 12 to avoid occupying the space on the bottom surface of the steel mesh body 1. At the same time, it ensures that the vibration energy is efficiently transmitted to the steel mesh body 1 and reduces energy loss.

[0022] like Figure 2 As shown, the micro-vibration separation assembly 5 includes a piezoelectric ceramic sheet 51 and a vibration transmission rod 52. A flexible conductive paste 53 is filled between the piezoelectric ceramic sheet 51 and the vibration transmission rod 52. The vibration transmission rod 52 extends along the thickness direction of the stencil body 1. The high-frequency vibration generated by the piezoelectric ceramic sheet 51 is coupled to the vibration transmission rod 52 through the flexible conductive paste 53. The flexible conductive paste 53 buffers thermal stress and optimizes vibration transmission efficiency, while the vibration transmission rod 52 conducts vibration energy, resulting in more thorough separation of the solder paste from the stencil.

[0023] The end of the vibration transmission rod 52 is tapered, which allows vibration energy to be focused at the tapered end.

[0024] The vibration transmission rod 52 is inclined, with its axis forming an acute angle α with the sidewall of the mesh 10 to which the tapered end points. The inclined arrangement of the vibration transmission rod 52 allows its vibration waves to propagate along the sidewall of the mesh 10, rather than impacting the solder paste perpendicularly, thus avoiding solder paste splashing or bridging and optimizing the distribution of vibration energy at the interface between the solder paste and the stencil. The preferred range of the acute angle α is 35° to 55°.

[0025] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A circuit board stencil release structure to prevent solder paste adhesion, comprising a stencil body (1) and a mounting frame (2) connected to the periphery of the stencil body (1), characterized in that: It also includes a multi-stage buffer demolding mechanism, which consists of a flexible support layer (4) disposed between the steel mesh body (1) and the circuit board (3) and a micro-vibration demolding component (5) distributed around the mesh (10) of the steel mesh body (1); the flexible support layer (4) provides a progressive separation force through deformation gradient during demolding, and the micro-vibration demolding component (5) applies micro-vibration at the moment of demolding.

2. The circuit board printing stencil release structure for preventing solder paste adhesion according to claim 1, characterized in that: The flexible support layer (4) is evenly distributed on the bottom surface of the steel mesh body (1), avoiding the mesh holes (10).

3. The circuit board printing stencil release structure for preventing solder paste adhesion according to claim 2, characterized in that: The bottom surface of the steel mesh body (1) is provided with a support layer mounting groove (11) corresponding to the flexible support layer (4); the flexible support layer (4) protrudes from the support layer mounting groove (11) under normal conditions, and can be gradually compressed and embedded into the support layer mounting groove (11) during printing pressure; the lower surface of the steel mesh body (1) contacts the solder pads of the circuit board (3).

4. A circuit board printing stencil release structure for preventing solder paste adhesion according to claim 1, 2, or 3, characterized in that: The flexible support layer (4) includes a high-hardness layer (41) and a low-hardness layer (42) stacked on top of each other to provide a progressive separation force through the material deformation gradient during demolding.

5. The circuit board printing stencil release structure for preventing solder paste adhesion according to claim 1, characterized in that: The bottom surface of the steel mesh body (1) is provided with a vibration component installation groove (12), and the micro-vibration detachment component (5) is embedded in the vibration component installation groove (12).

6. A circuit board stencil release structure for preventing solder paste adhesion according to claim 1 or 5, characterized in that: The micro-vibration detachment component (5) includes a piezoelectric ceramic sheet (51) and a vibration transmission rod (52), with a flexible conductive paste (53) filling the space between the piezoelectric ceramic sheet (51) and the vibration transmission rod (52), and the vibration transmission rod (52) extending along the thickness direction of the steel mesh body (1).

7. The circuit board printing stencil release structure for preventing solder paste adhesion according to claim 6, characterized in that: The end of the vibration transmission rod (52) is tapered.

8. The circuit board printing stencil release structure for preventing solder paste adhesion according to claim 7, characterized in that: The vibration transmission rod (52) is inclined, wherein the axis forms an acute angle α with the sidewall of the mesh (10) pointed to by the tapered end.

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