Flexible wiring board structure for single tube servo driving circuit

Abstract

The utility model discloses a kind of flexible circuit board structures of single-tube servo drive circuit, including circuit board, heat-conducting pad and radiator, circuit board is fixedly connected with radiator, heat-conducting pad is located between radiator and circuit board to fill the gap between radiator and circuit board, circuit board is equipped with stress sensitive device, slot is opened in the circumferential side of stress sensitive device to form cantilever structure between stress sensitive device and circuit board.The utility model can reduce or eliminate the stress deformation of cantilever structure where stress sensitive device is located caused by heat-conducting pad extrusion, thereby reduce the failure rate of stress sensitive device, improve the assembly quality of circuit board.

Description

Technical Field

[0001] This utility model belongs to the field of servo driver technology, and in particular relates to a flexible circuit board structure for a single-tube servo drive circuit. Background Technology

[0002] A servo driver is a device used to control servo motors, precisely controlling their speed, position, and acceleration. The transistor drive circuit is the core module in a single-transistor servo driver that amplifies power. Each transistor generates heat loss during operation, which is dissipated by filling the gap between the circuit board and the heatsink with an insulating thermal pad while maintaining basic insulation. During assembly, the single-transistor drive circuit board deforms due to the compression of the insulating thermal pad, causing stress-sensitive components such as ceramic capacitors to crack. In previous solutions, ceramic resistors near the single-transistor area were easily damaged during assembly, or their performance deteriorated after a period of driver use due to stress release. Utility Model Content

[0003] The purpose of this invention is to solve the above-mentioned technical problems in the prior art and provide a flexible circuit board structure for a single-tube servo drive circuit, which can reduce or eliminate the stress deformation of the cantilever structure where the stress-sensitive device is located due to the compression of the heat-conducting pad, thereby reducing the defect rate of the stress-sensitive device and improving the assembly quality of the circuit board.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A flexible circuit board structure for a single-tube servo drive circuit is characterized by comprising a circuit board, a thermal pad, and a heat sink. The circuit board is fixedly connected to the heat sink. The thermal pad is disposed between the heat sink and the circuit board to fill the gap between the heat sink and the circuit board. The circuit board is provided with a stress-sensitive device. A slot is opened on the periphery of the stress-sensitive device to form a cantilever structure between the stress-sensitive device and the circuit board.

[0006] Furthermore, the stress-sensitive device is located at the edge of the circuit board, and the slot is L-shaped.

[0007] Furthermore, the stress-sensitive device is located at the edge of the circuit board, and there are two slots, one on each side of the stress-sensitive device.

[0008] Furthermore, the stress-sensitive device is located at a non-edge location on the circuit board, and the slot is U-shaped.

[0009] Furthermore, the heat sink is provided with a receiving groove, the position of which corresponds vertically to the position of the stress-sensitive device.

[0010] Furthermore, the horizontal projected area of ​​the receiving groove is larger than the horizontal projected area of ​​the cantilever structure.

[0011] Furthermore, stress-sensitive devices include resistors and capacitors made of brittle materials, chips with densely packed solder pins, and semiconductor piezoresistive elements.

[0012] This utility model also discloses a flexible circuit board structure for a single-tube servo drive circuit, characterized in that it includes a circuit board, a thermal pad, a fixing plate, and a heat sink. The circuit board is connected to the fixing plate, and the heat sink is fixedly connected to the circuit board. The fixing plate is provided with a stress-sensitive device. The thermal pad is provided between the heat sink and the circuit board to guide the heat of the electronic components and the stress-sensitive device on the circuit board to the heat sink for heat dissipation.

[0013] Furthermore, a connection is provided between the fixing plate and the circuit board.

[0014] This utility model, by adopting the above-mentioned technical solution, has the following beneficial effects:

[0015] This invention creates a slot on the circuit board around the stress-sensitive device, forming a cantilever structure between the circuit board and the main body of the circuit board. When the circuit board is fixed, the stress-sensitive device is subjected to pressure from the thermal pad, causing the cantilever structure to bend, thereby reducing the pressure on the stress-sensitive device. This ensures that the cantilever structure does not deform or the deformation is much smaller than the allowable value of the stress-sensitive device, reducing the defect rate of the stress-sensitive device and improving the assembly quality of the circuit board. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings:

[0017] Figure 1 This is a schematic diagram of the flexible circuit board structure of a single-tube servo drive circuit according to this utility model.

[0018] Figure 2 This is an exploded view of the flexible circuit board structure in this utility model;

[0019] Figure 3 This is a schematic diagram of the structure of Embodiment 1 of this utility model;

[0020] Figure 4 This is a schematic diagram of the structure of Embodiment 2 of this utility model;

[0021] Figure 5 This is a schematic diagram of the structure of Embodiment 3 of this utility model;

[0022] Figure 6 This is a schematic diagram of the structure of Embodiment 1 of the present invention, which uses a fixing plate to connect the circuit board;

[0023] Figure 7This is a schematic diagram of the structure of Embodiment 2 of the present invention, which uses a fixed plate to connect the circuit board.

[0024] In the diagram, 1-Circuit board; 2-Thermal pad; 3-Heat sink; 4-Stress-sensitive device; 5-Slot; 6-Cantilever structure; 7-Receiving slot; 8-Fixing plate; 9-Connecting part. Detailed Implementation

[0025] like Figures 1 to 5 As shown, this utility model discloses a flexible circuit board structure for a single-tube servo drive circuit, including a circuit board 1, a thermal pad 2, and a heat sink 3. The circuit board 1 is used to connect and fix electronic components and a stress-sensitive device 4. The thermal pad 2 is used to conduct heat from the circuit board 1 and the electronic components on the circuit board 1 to the heat sink 3. The heat sink 3 is used for heat dissipation. The circuit board 1 is fixedly connected to the heat sink 3. The thermal pad 2 is placed between the heat sink 3 and the circuit board 1 to fill the gap between them. The circuit board 1 is equipped with a stress-sensitive device 4, and a slot 5 is formed on the periphery of the stress-sensitive device 4 to form a cantilever structure 6 between the stress-sensitive device 4 and the circuit board 1. The circuit board 1 is generally fixed to the heat sink 3 with fastening screws. As the fastening screws are tightened, the circuit board 1 compresses the thermal pad 2, causing the thermal pad 2 to deform. Simultaneously, the circuit board 1 is subjected to a rebound force and deforms. With the above settings, during the fastening process of the circuit board 1, the rebound force of the thermal pad 2 pressing the stress-sensitive device 4 can be applied to the cantilever structure 6 and cause the cantilever structure 6 to bend, thereby reducing the stress deformation of the cantilever structure 6 where the stress-sensitive device 4 is located, reducing the defect rate of the stress-sensitive device 4, and thus improving the assembly quality of the circuit board 1.

[0026] like Figure 3 As shown, in one implementation, the stress-sensitive device 4 is located at the edge of the circuit board 1, and the slot 5 is "L"-shaped. When the stress-sensitive device 4 is located at the edge of the circuit board 1, the "L"-shaped slot 5 can form a cantilever structure 6, and can reduce the slot length, ensuring the overall strength of the circuit board 1. Moreover, only one slot 5 needs to be opened, making the slotting convenient and allowing for one-time molding.

[0027] like Figure 4 As shown, in another implementation, the stress-sensitive device 4 is located at the edge of the circuit board 1, and there are two slots 5, one on each side of the stress-sensitive device 4. In this slotting method, the connection of the cantilever structure 6 is closer to the center of the circuit board 1 than the connection of the cantilever structure 6 with the "L"-shaped slot 5, making wiring more convenient.

[0028] like Figure 5As shown, in the third implementation method, the stress-sensitive device 4 is located at a non-edge location of the circuit board 1, and the slot 5 is U-shaped. This type of slotting is generally located at the center of the circuit board 1, and the opening direction of the U-shaped slot is adapted to the routing of the stress-sensitive device 4.

[0029] As one implementation method, anti-crack holes or arc transitions are provided at the ends of the slot 5 to prevent the circuit board 1 from cracking when the cantilever structure 6 is bent significantly, thereby improving the service life of the circuit board 1.

[0030] like Figure 2 As shown, in one implementation, the heat sink 3 is provided with a receiving groove 7, the position of which corresponds vertically to the position of the stress-sensitive device 4. This arrangement allows the receiving groove 7 to accommodate a portion of the thermal pad 2, thus reducing the degree of compression of the thermal pad 2 at the receiving groove 7 when the circuit board 1 is fixed to the heat sink 3. This results in less deformation of the thermal pad 2 corresponding to the position of the stress-sensitive device 4, thereby reducing the pressure on the stress-sensitive device 4 caused by the compression of the thermal pad 2, reducing stress deformation at the cantilever structure 6, making the stress-sensitive device 4 less prone to damage, and extending its service life.

[0031] Specifically, the horizontal projected area of ​​the receiving groove 7 is larger than the horizontal projected area of ​​the cantilever structure 6. This arrangement ensures that the receiving groove 7 completely accommodates the heat-conducting pad 2 located at the stress-sensitive device 4, preventing the heat-conducting pad 2 from squeezing the stress-sensitive device 4. This eliminates the pressure on the stress-sensitive device 4 caused by the heat-conducting pad 2 squeezing, thus making the stress-sensitive device 4 less prone to damage and extending its service life.

[0032] As one implementation method, the stress-sensitive device 4 includes resistors and capacitors made of brittle materials, chips with densely packed welded pins, semiconductor piezoresistive elements, etc.

[0033] This invention creates a slot 5 on the circuit board 1 surrounding the stress-sensitive device 4, forming a cantilever structure 6 between the circuit board 1 where the stress-sensitive device 4 is located and the main body of the circuit board 1. When the circuit board 1 is fixed, the stress-sensitive device 4 is subjected to the pressure of the heat-conducting pad 2, causing the cantilever structure 6 to bend, thereby reducing the pressure on the stress-sensitive device 4. This ensures that the area of ​​the circuit board 1 where the stress-sensitive device 4 is located does not deform or the amount of deformation is much smaller than the allowable value of the stress-sensitive device 4, reducing the defect rate of the stress-sensitive device 4 and improving the assembly quality of the circuit board 1.

[0034] like Figure 6 and Figure 7As shown, this utility model also discloses a flexible circuit board 1 structure for a single-tube servo drive circuit, including a circuit board 1, a thermal pad 2, a fixing plate 8, and a heat sink 3. The circuit board 1 is used to connect and fix electronic components; the thermal pad 2 is used to conduct heat from the circuit board 1 and the electronic components on the circuit board 1 to the heat sink 3; the heat sink 3 is used for heat dissipation. The circuit board 1 is connected to the fixing plate 8, and the heat sink 3 is fixedly connected to the circuit board 1. The fixing plate 8 is provided with a stress-sensitive device 4. The thermal pad 2 is provided between the heat sink 3 and the circuit board 1 to guide the heat from the electronic components on the circuit board 1 and the stress-sensitive device 4 to the heat sink 3 for heat dissipation. Through the above arrangement, the stress-sensitive device 4 is fixed on the fixing plate 8. The fixing plate 8 is generally protruding from the body of the circuit board 1, which can reduce the compression deformation of the thermal pad 2 caused by the circuit board 1 pressing the thermal pad 2 in the area of ​​the fixing plate 8 when the heat sink 3 and the circuit board 1 are fixed, thereby reducing the deformation of the fixing plate 8 under pressure, which could lead to the stress-sensitive device 4 tearing and reduce the defect rate of the stress-sensitive device 4.

[0035] As one implementation, a connecting portion 9 is provided between the fixing plate 8 and the circuit board 1. This arrangement facilitates the connection between the fixing plate 8 and the circuit board 1. The connecting portion 9 can be adaptively adjusted according to usage requirements: when the connection between the fixing plate 8 and the circuit board 1 needs to be strengthened, the connecting portion 9 can be a trapezoidal structure, with the short side length equal to the width of the fixing plate 8 and the long side connected to the circuit board 1; when the fixing plate 8 needs to achieve a larger bending angle, the width of the connecting portion 9 can be less than the width of the fixing plate 8. The number of connecting portions 9 can also be adjusted according to requirements, such as using one, two, or more.

[0036] This invention provides a fixing plate 8 outside the circuit board 1 for separately mounting stress-sensitive devices 4. This reduces the pressure of the thermal pad 2 on the stress-sensitive devices 4 on the fixing plate 8 when the circuit board 1 is fixed, so that the fixing plate 8 does not deform or the amount of deformation is much smaller than the allowable value of the stress-sensitive devices 4, thereby reducing the defect rate of the stress-sensitive devices 4 and improving the assembly quality of the circuit board 1.

[0037] The above are merely specific embodiments of this utility model, but the technical features of this utility model are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on this utility model to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of this utility model.

Claims

1. A flexible circuit board structure for a single-tube servo drive circuit, characterized in that: The device includes a circuit board, a thermal pad, and a heat sink. The circuit board is fixedly connected to the heat sink. The thermal pad is disposed between the heat sink and the circuit board to fill the gap between them. The circuit board is provided with a stress-sensitive device. The stress-sensitive device has a slot on its periphery to form a cantilever structure between the stress-sensitive device and the circuit board.

2. The flexible circuit board structure of a single-tube servo drive circuit according to claim 1, characterized in that: The stress-sensitive device is located at the edge of the circuit board, and the slot is "L" shaped.

3. The flexible circuit board structure of a single-tube servo drive circuit according to claim 1, characterized in that: The stress-sensitive device is located at the edge of the circuit board, and there are two slots, which are respectively located on both sides of the stress-sensitive device.

4. The flexible circuit board structure of a single-tube servo drive circuit according to claim 1, characterized in that: The stress-sensitive device is located at a non-edge location on the circuit board, and the slot is U-shaped.

5. The flexible circuit board structure of a single-tube servo drive circuit according to claim 1, characterized in that: The heat sink is provided with a receiving groove, and the position of the receiving groove corresponds vertically to the position of the stress-sensitive device.

6. The flexible circuit board structure of a single-tube servo drive circuit according to claim 5, characterized in that: The horizontal projected area of ​​the receiving groove is greater than the horizontal projected area of ​​the cantilever structure.

7. The flexible circuit board structure of a single-tube servo drive circuit according to claim 1, characterized in that: The stress-sensitive device includes resistors and capacitors made of brittle materials, chips with densely packed solder pins, and semiconductor piezoresistive elements.

8. A flexible circuit board structure for a single-tube servo drive circuit, characterized in that: The device includes a circuit board, a thermal pad, a mounting plate, and a heat sink. The circuit board is connected to the mounting plate, and the heat sink is fixedly connected to the circuit board. The mounting plate is equipped with a stress-sensitive device. The thermal pad is located between the heat sink and the circuit board to conduct heat from the electronic components on the circuit board and the stress-sensitive device to the heat sink for heat dissipation.

9. The flexible circuit board structure of a single-tube servo drive circuit according to claim 8, characterized in that: A connection is provided between the fixing plate and the circuit board.

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