PCB (Printed Circuit Board) sintering tool

Abstract

The invention relates to the technical field of printed circuit board sintering, and discloses a PCB (printed circuit board) sintering tool, which comprises a pressing plate and a plurality of spring needles, the pressing plate is fixed on the base and comprises a plurality of first limiting through holes, and the first limiting through holes are in one-to-one correspondence with the spring needles; the spring needle comprises a main body, a spring, a pressure head and a flange; the spring is arranged at the head part of the main body, one end of the spring is fixed, and the other end of the spring is connected with the tail part of the pressure head; the flange is fixedly connected to the outer surface of the main body, and the diameter of the flange is larger than that of the first limiting through hole; the main body penetrates through the first limiting through hole, the head portion of the pressing head makes contact with the PCB, the flange makes contact with the lower surface of the pressing plate, and the spring is in a compressed state. According to the invention, the probability of voids after sintering caused by gaps generated by height reduction after tin sheet melting can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of printed circuit board sintering, and in particular to a PCB printed circuit board sintering tool. Background Art

[0002] With the development trend of miniaturization and high integration of microwave components, it is necessary to mix the RF strip lines in the microwave components into the PCB printed board, and then sinter the PCB printed board on the shell through a solder sheet with a thickness of 0.05mm-0.1mm. However, it is necessary to ensure that the reference ground of the PCB printed board is well welded with the shell, that is, it is necessary to control the void rate between the reference ground of the PCB printed board and the shell after sintering. After sintering according to the existing PCB printed board sintering method, the void rate between the reference ground of the PCB printed board and the shell is generally around 20%. In order to ensure that the PCB printed board is in close contact with the shell during the sintering process, thereby reducing the void rate, a flat metal plate is usually designed and processed, and the flat metal plate is fixed to the sintering tooling by screws to press the PCB printed board. However, this method cannot reduce the void rate and has poor consistency. The reasons are: first, the flat metal plate has been locked and fixed by screws before sintering, but as the tin sheet melts at high temperature during the sintering process and flows and diffuses around, the thickness of the tin sheet decreases, causing the PCB printed board to drop a small height, making it impossible for the flat metal plate to play a good pressing role on the PCB printing, resulting in voids between the reference ground of the PCB printed board and the shell after sintering; second, the flat metal plate will be slightly deformed during the sintering process due to high temperature or external force applied by screws, resulting in a small gap between the flat metal plate and the PCB printed board. The PCB printed board cannot be subjected to the pressing force provided by the flat metal plate in the gap, resulting in voids between the reference ground of the PCB printed board and the shell after sintering. The PCB printed board is usually mounted with components. In order to avoid the position of components, the flat metal plate needs to be hollowed out at the position corresponding to the components, resulting in a reduction in the contact and pressing surface between the PCB printed board and the flat metal plate, resulting in uneven pressure applied by the flat metal plate on the PCB printed board, causing the PCB printed board to tilt, which in turn causes a void between the reference ground of the PCB printed board and the shell after sintering.

[0003] In view of this, this application is hereby filed. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the existing PCB printed board sintering process easily leads to a large number of cavities between the reference ground of the PCB printed board and the shell after sintering.

[0005] In order to solve the above technical problems, the present invention is implemented by the following technical solutions:

[0006] A PCB printed board sintering tool is provided, comprising a pressing plate and a plurality of spring pins; the pressing plate is fixed, the pressing plate comprises a plurality of first limiting through holes, and the first limiting through holes correspond to the spring pins one by one; the spring pin comprises a main body, a spring, a pressing head and a flange; the spring is arranged at the head of the main body, one end of the spring is fixed, and the other end of the spring is connected to the tail of the pressing head; the flange is fixedly connected to the outer surface of the main body, and the diameter of the flange is greater than the diameter of the first limiting through holes; the main body passes through the first limiting through holes, the head of the pressing head contacts the PCB printed board, the flange contacts the lower surface of the pressing plate, and the spring is in a compressed state.

[0007] Furthermore, the main body includes a cavity; the cavity is located inside the main body, and the cavity is located at the head of the main body; the spring is located in the cavity, and one end of the spring is fixedly connected to the bottom of the cavity.

[0008] Furthermore, the height of the flange from the PCB printed board is equal to the height of the lower surface of the pressing plate from the PCB printed board.

[0009] Furthermore, a sleeve is provided at the tail of the pressure head, the sleeve is located in the cavity, the outer surface of the side wall of the sleeve is in contact with the inner surface of the side wall of the cavity, and the spring is located in the sleeve.

[0010] Furthermore, the PCB printed circuit board sintering tooling also includes: a limit plate; the limit plate includes a plurality of second limit through holes; the positions of the second limit through holes correspond one to one with the positions of the first limit through holes; the main body passes through the second limit through holes; the limit plate is fixedly connected to the shell; the limit plate is located below the pressure plate.

[0011] Compared with the prior art, the present invention has the following advantages and beneficial effects: through the mutual cooperation between the spring pin and the pressure plate, the surface contact pressing and fixing method adopted by the existing PCB printed board sintering tooling is optimized to a point contact pressing and fixing method, and the pressing force at different points is flexibly controlled by applying elastic force to the PCB printed board through the spring, so that different areas of the PCB printed board can be evenly subjected to pressure to ensure the tightness of the contact between the PCB printed board and the shell, and the probability of voids after sintering caused by the gap generated by the height reduction after the tin sheet is melted can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 A schematic diagram of the overall structure of a PCB printed board sintering tooling provided in an embodiment of the present invention;

[0014] Figure 2 A schematic structural diagram of a spring pin provided in an embodiment of the present invention.

[0015] Marks and corresponding parts names in the attached drawings:

[0016] 1-pressing plate, 2-spring needle, 3-housing, 4-PCB printed board, 5-limiting plate, 6-enclosing frame screw, 8-enclosing frame, 9-locating pin, 11-first limiting through hole, 21-main body, 22-spring, 23-pressing head, 24-flange, 211-cavity, 231-sleeve. DETAILED DESCRIPTION

[0017] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0018] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to one of ordinary skill in the art that these specific details are not necessarily employed to practice the present invention. In other embodiments, in order to avoid obscuring the present invention, well-known structures, circuits, materials, or methods are not specifically described.

[0019] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0020] In the description of the present invention, the directions or positional relationships indicated by terms such as “front”, “rear”, “left”, “right”, “up”, “down”, “vertical”, “horizontal”, “high”, “low”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the scope of protection of the present invention.

[0021] Example: Figure 1 A PCB printed board sintering tool provided in an embodiment of the present invention comprises a pressing plate 1, a plurality of spring pins 2, a shell 3, a limiting plate 5, a surrounding frame 8 and a positioning pin. The surrounding frame 8 is fixed to the shell 3 by a surrounding frame screw 6, and the PCB printed board 4 is installed in the shell 3. The pressing plate 1 is provided with a plurality of first limiting through holes 11, the number of the first limiting through holes 11 is the same as the number of the spring pins 2, and one first limiting through hole 11 corresponds to one spring pin 2. The limiting plate 5 is provided with a plurality of second limiting through holes, the number of the second limiting through holes is the same as the number of the first limiting through holes 11, and the positions of the second limiting through holes correspond one to one with the positions of the first limiting through holes 11. The first limiting through holes 11 of the pressing plate 1 and the second limiting through holes of the limiting plate 5 can ensure that the spring pins 2 are in a vertical state during operation.

[0022] like Figure 2 As shown, the spring needle 2 is a cylindrical structure as a whole, including a main body 21, a spring 22, a pressure head 23 and a flange 24. Among them, the head of the main body 21 is provided with a cavity 211 for installing the spring 22, and the cavity 211 is located inside the main body 21. The spring 22 is installed in the cavity 211, and one end of the spring 22 is fixedly connected to the bottom of the cavity 211. Further, the pressure head 23 is a conical structure, and a cylindrical sleeve 231 is provided at the tail of the pressure head 23, and the outer surface of the side wall of the sleeve 231 is smooth. Along the length direction, the sleeve 231 is nested in the cavity 211, and the outer surface of the side wall of the sleeve 231 contacts the inner surface of the side wall of the cavity 211. The spring 22 passes through the sleeve 231 and is fixedly connected to the tail of the pressure head 23. The contact between the side wall of the sleeve 231 and the side wall of the cavity 211 can ensure that the pressure head 23 always keeps moving along the length direction of the spring needle 2. The flange 24 is fixedly connected to the outer surface of the main body 21 , and the diameter of the flange 24 is greater than the diameter of the first limiting through hole 11 .

[0023] like Figure 1 and Figure 2As shown, during installation, first fix the limit plate 5 to the housing 3 through the positioning pin 9; then pass the head of the spring needle 2 through the second limit hole, so that the tip of the pressure head 23 contacts the surface of the PCB 4; next, pass the tail of the spring needle 2 through the first limit hole 11 of the pressure plate 1, and use the pressure plate screw to press and fix the pressure plate 1 and the limit plate 5, so that the spring 22 is in a compressed state. Since the height of the flange 24 from the PCB 4 is equal to the height of the lower surface of the pressure plate 1 from the PCB 4, under the interaction between the flange 24 and the bottom of the pressure plate 1, the tip of the pressure head 23 is in close contact with the surface of the PCB 4.

[0024] In summary, the PCB sintering tool provided in this embodiment optimizes the surface contact pressing and fixing method adopted by the existing PCB sintering tool into a point contact pressing and fixing method through the cooperation between the spring pin and the pressure plate. The spring applies elastic force to the PCB to flexibly control the pressing force at different points, so that different areas of the PCB can be evenly subjected to pressure to ensure the tightness of the contact between the PCB and the shell, and the probability of voids after sintering caused by the gap generated by the height reduction after the tin sheet is melted can be reduced.

[0025] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A PCB printed board sintering tool, characterized in that: The invention comprises a pressing plate (1) and a plurality of spring pins (2); the pressing plate (1) is fixed, the pressing plate (1) comprises a plurality of first limiting through holes (11), and the first limiting through holes (11) correspond to the spring pins (2) one by one; the spring pin (2) comprises a main body (21), a spring (22), a pressing head (23) and a flange (24); the spring (22) is arranged at the head of the main body (21), one end of the spring (22) is fixed, and the other end of the spring (22) is connected to the tail of the pressing head (23); the flange (24) is fixedly connected to the outer surface of the main body (21), and the diameter of the flange (24) is greater than the diameter of the first limiting through holes (11); the main body (21) passes through the first limiting through holes (11), the head of the pressing head (23) contacts with a PCB (4), the flange (24) contacts with the lower surface of the pressing plate (1), and the spring (22) is in a compressed state.

2. A PCB printed circuit board sintering tool according to claim 1, characterized in that: The main body (21) comprises a cavity (211); the cavity (211) is located inside the main body (21), and the cavity (211) is located at the head of the main body (21); the spring (22) is located in the cavity (211), and one end of the spring (22) is fixedly connected to the bottom of the cavity (211).

3. A PCB printed board sintering tool according to claim 1 or 2, characterized in that: The height of the flange (24) from the PCB (4) is equal to the height of the lower surface of the pressing plate (1) from the PCB (4).

4. A PCB printed board sintering tool according to claim 2, characterized in that: A sleeve is provided at the tail of the pressure head (23), the sleeve (231) is located in the cavity (211), the outer surface of the side wall of the sleeve (231) contacts the inner surface of the side wall of the cavity (211), and the spring (22) is located in the sleeve (231).

5. A PCB printed board sintering tool according to claim 1 or 2, characterized in that: Also includes: A limit plate (5); the limit plate (5) comprises a plurality of second limit through holes; the positions of the second limit through holes correspond one to one with the positions of the first limit through holes (11); the main body (21) passes through the second limit through holes; the limit plate (5) is fixedly connected to the shell (1); the limit plate (5) is located below the pressure plate (1).

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