A positioning fixture device for a high-power laser bar encapsulation vacuum reflow oven

Abstract

This invention relates to the field of ultra-precision electronic product processing technology, specifically a positioning fixture device for a high-power laser bar packaging vacuum reflow oven. The device includes: a base with a right-angle clamping portion on its top for clamping an etched silicon wafer; an etched silicon wafer positioning groove module installed on the right-angle clamping portion, used to clamp a chip assembly to be welded and to abut the etched silicon wafer; and an adjustment assembly module for positioning the etched silicon wafer positioning groove module. The advantages of this invention are: it clamps the workpiece in several parts on the base and the etched silicon wafer positioning groove module, and then positions each part by adjusting the assembly module; it ensures a high degree of positional freedom for the probe fixture, enabling rapid response to changes in workpiece position and accurate workpiece clamping; it ensures relatively independent welding between components, preventing movement of the previous component due to the placement of the next component, thus improving the quality of the finished package.

Description

Technical Field

[0001] This invention relates to the field of ultra-precision electronic product processing technology, specifically a positioning fixture device for a high-power laser bar packaging vacuum reflow oven. Background Technology

[0002] High-power laser bar packaging has strict technical requirements. Due to the very small size of the product, some areas cannot be touched, and the assembly process must be carried out under a microscope. The chip positioning accuracy and the heat sink positioning accuracy for direct soldering must be within a few micrometers. Furthermore, the packaging process must be carried out in a vacuum environment, and a certain pressure must be applied to the workpiece to ensure good coplanarity.

[0003] Furthermore, since multiple components need to be assembled and positioned step by step to complete vacuum reflow welding during the laser vacuum welding process, each component must be precisely positioned. At the same time, it is necessary to ensure that the welding between components is relatively independent and that the placement of the next component does not cause the movement of the previous component. This undoubtedly places higher technical requirements on the high-power laser bar packaging vacuum reflow oven fixture device.

[0004] Most existing positioning fixtures for high-power laser bar packaging vacuum reflow ovens use a combination of a mounting base and a positioning clamp. When the position and jaw opening need to be adjusted, the corresponding operation is achieved by rotating the corresponding nut with a wrench. This method cannot quickly respond to changes in the workpiece's position and has low positioning accuracy. Summary of the Invention

[0005] The purpose of this invention is to provide a positioning fixture device for a high-power laser bar packaging vacuum reflow oven, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A positioning fixture device for a high-power laser bar packaging vacuum reflow oven includes:

[0008] A base, the top of which has a right-angle clamping portion for clamping an etched silicon wafer;

[0009] An etched silicon wafer positioning groove module installed in a right-angle clamping part is used to clamp the chip group to be welded and make the chip group to be welded abut against the etched silicon wafer.

[0010] The adjustment assembly module is partially installed on the top of the base away from the right-angle clamping part, and the other two adjustment assembly modules are installed opposite each other on both sides of the etched silicon wafer positioning groove module, both used to position the etched silicon wafer positioning groove module.

[0011] As a further embodiment of the present invention: the top of the base is provided with a worktable and a boss, the top surface of the worktable is perpendicular to the surface of the boss near the side of the etched silicon wafer positioning groove module, and a clamping plate is installed on the top surface of the worktable to form a right-angle clamping part with the boss.

[0012] As a further embodiment of the present invention: the tilt angle of the worktable is 30°, the tilt angle of the boss is 120°, and the included angle between the contact surfaces of the worktable and the boss is 90°.

[0013] As a further embodiment of the present invention: the silicon wafer positioning groove module includes a limiting boss, a pressure plate and fasteners. The two limiting bosses are installed on the worktable at intervals by fasteners to form a positioning part. The pressure plate constrains the chip group to be soldered in the positioning part by fasteners. The adjustment assembly module adjusts the constraint state between the pressure plate and the positioning part by fasteners.

[0014] As a further embodiment of the present invention: the chip assembly to be soldered includes an etched silicon wafer, a heat sink, and a chip disposed on the heat sink. The heat sink is mounted on a positioning part through a substrate. A ceramic sheet is also disposed on the substrate. Copper foil is disposed on the top of the ceramic sheet and the chip. A ceramic pressure plate for pressing the chip is disposed on the chip. A pressure plate connected to the positioning part is disposed on the copper foil. The etched silicon wafer is used to position the relative positions of the heat sink and the chip.

[0015] As a further embodiment of the present invention: the adjustment assembly module includes a probe fixture, a first adjustment assembly mechanism, and a second adjustment assembly mechanism. One of the second adjustment assembly mechanisms is installed on the top of the base away from the right-angle clamping part, and the second adjustment assembly mechanism drives the probe fixture installed at its output end to rotate. A plurality of the first adjustment assembly mechanisms are installed in pairs opposite to each other on both sides of the etching silicon wafer positioning slot module. The first adjustment assembly mechanism drives the probe fixture installed at its output end to rotate to position the etching silicon wafer positioning slot module.

[0016] As a further embodiment of the present invention: both the first adjustment assembly mechanism and the second adjustment assembly mechanism include a worm, a turbine, a turbine pin, and a bracket. The worm and the turbine pin are mounted perpendicularly to each other on the bracket. The turbine and the probe clamp, which mesh with the worm, are coaxially mounted on the turbine pin. The worm drives the probe clamp to rotate through the turbine.

[0017] As a further embodiment of the present invention: the first adjustment assembly mechanism or the second adjustment assembly mechanism further includes a worm gear handle, which is mounted on the top of the worm gear.

[0018] As a further aspect of the present invention: each of the first adjustment assembly mechanisms is connected to a rotary assembly mechanism via an intermediate transmission group, and the rotary assembly mechanism drives the bracket to rotate via the intermediate transmission group.

[0019] As a further embodiment of the present invention: the intermediate transmission assembly includes a driven wheel shaft and a driven wheel. The driven wheel is mounted on the bottom of the bracket via the driven wheel shaft, and the bracket is rotatably mounted on the base via the driven wheel shaft. The driven wheel is connected to a rotary assembly mechanism, and the rotary assembly mechanism drives the bracket to rotate via the driven wheel.

[0020] As a further embodiment of the present invention: the rotary assembly mechanism includes a drive gear shaft, a spur gear handle and a drive wheel. The spur gear handle and the drive wheel are coaxially mounted on the base via the drive gear shaft. The drive wheel meshes with the intermediate transmission group. The rotation of the spur gear handle drives the drive wheel to rotate, and the rotation of the drive wheel drives the intermediate transmission group to rotate.

[0021] Compared with existing technologies, the advantages of this invention are as follows: the workpiece is clamped in several parts on the base and the etched silicon wafer positioning groove module, and each part is independently positioned by adjusting the assembly module; the structural design of the base provides a good workpiece assembly and chip welding environment, making the workpiece assembly process more efficient and the chip welding quality more reliable; the structural design of the etched silicon wafer positioning groove module enables the chip and heat sink to obtain better positional accuracy, which facilitates the positioning of the chip protrusion and controls the protrusion distance of the chip's light-emitting surface within 5um, effectively preventing the solder from blocking the light-emitting point after welding, causing the laser to burn out, and improving the yield of laser packaging; the adjustment assembly module can ensure that the probe fixture has a high degree of positional freedom, can quickly respond to changes in the position of the workpiece, and accurately clamp the workpiece; it ensures that the welding between components is relatively independent, and the placement of the next component will not cause the movement of the previous component, thus improving the quality of the finished laser packaging. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the assembly of the positioning fixture device for the high-power laser bar packaging vacuum reflow oven in an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the base structure in an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of the silicon wafer positioning groove module in an embodiment of the present invention.

[0025] Figure 4 for Figure 3 Enlarged diagram of point A in the middle.

[0026] Figure 5 This is a schematic diagram of the structure of the first adjustment assembly mechanism in an embodiment of the present invention.

[0027] Figure 6 This is a schematic diagram of the structure of the second adjustment assembly mechanism in an embodiment of the present invention.

[0028] Figure 7 This is a schematic diagram of the rotating assembly mechanism in an embodiment of the present invention.

[0029] In the attached diagram: 1. Base; 2. Etched silicon wafer positioning groove module; 3. First adjustment assembly mechanism; 4. Second adjustment assembly mechanism; 5. Rotary assembly mechanism; 11. Worktable; 12. Boss; 13. Clamping plate; 14. Socket head screw I; 15. Limiting boss; 21. Pressure plate; 22. Ceramic pressing sheet; 23. Substrate; 24. Heat sink; 25. Chip; 26. Ceramic sheet; 27. Copper foil; 28. Etched silicon wafer; 31. Worm handle I; 32. Worm I; 33. Turbine I; 34. Turbine pin I; 35. Support I; 36. Probe clamp I; 37. Driven wheel; 38. Driven wheel shaft. 39. Socket head cap set screw I; 310. Socket head cap screw II; 311. Cross-head countersunk screw I; 312. Cross-head pan head screw I; 41. L-shaped bracket; 42. Worm gear handle II; 43. Worm gear II; 44. Turbine II; 45. Turbine pin II; 46. Bracket II; 47. Probe clamp II; 48. Socket head cap set screw II; 49. Socket head cap screw III; 410. Cross-head countersunk screw II; 411. Cross-head pan head screw II; 51. Spur gear handle; 52. Drive wheel; 53. Socket head cap set screw III. Detailed Implementation

[0030] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects disclosed in this embodiment as detailed in the appended claims.

[0031] Please see Figure 1-4 In this embodiment of the invention, a positioning fixture device for a high-power laser bar packaging vacuum reflow oven includes: a base 1, the top of which has a right-angle clamping portion for clamping an etched silicon wafer; an etched silicon wafer positioning groove module 2 installed on the right-angle clamping portion, the etched silicon wafer positioning groove module 2 being used to clamp a chip assembly to be soldered and to make the chip assembly to be soldered abut against the etched silicon wafer; and an adjustment assembly module, part of which is installed on one end of the top of the base 1 away from the right-angle clamping portion, and the other part of which is installed in pairs opposite to each other on both sides of the etched silicon wafer positioning groove module, both being used to position the etched silicon wafer positioning groove module 2.

[0032] Specifically, the right-angle clamping part is configured as follows: a worktable 11 and a boss 12 are provided on the top of the base. The top surface of the worktable 11 is perpendicular to the surface of the boss 12 near the silicon wafer positioning groove module. A clamping plate 13 is installed on the top surface of the worktable 11 to form a right-angle clamping part with the boss 12. Furthermore, the clamping plate 13 is installed on the worktable by a hexagonal head screw I14 to fix the silicon wafer 28. The degree of fixation of the clamping plate 13 to the silicon wafer 28 is adjusted by adjusting the hexagonal head screw I14.

[0033] The etched silicon wafer positioning groove module 2 includes limiting bosses 15, pressure plates 21, and fasteners. Two limiting bosses 15 are spaced apart on the worktable by fasteners to form a positioning part. The pressure plate 21, through fasteners, constrains the chip assembly to be soldered within the positioning part. The adjustment and assembly module adjusts the constraint state between the pressure plate and the positioning part using fasteners to ensure a tight fit between the chip assembly to be soldered and the etched silicon wafer. The fasteners include screws; the pressure plate 21 uses screws to fix the chip assembly to be soldered to the positioning part and forms a tight fit with the etched silicon wafer 28. This assembly ensures accurate positioning of the chip 25 and heat sink 24 within the chip assembly. The base's structural design provides a good environment for workpiece assembly and chip soldering, making the workpiece assembly process more efficient and the chip soldering quality more reliable.

[0034] The chip assembly to be soldered includes an etched silicon wafer 28, a heat sink 24, and a chip 25 disposed on the heat sink 24. The heat sink 24 is mounted on a positioning part via a substrate 23. A ceramic sheet 26 is also disposed on the substrate 23. Copper foil 27 is disposed on the top of the ceramic sheet 26 and the chip 25. A ceramic pressure plate 22 for pressing the chip is disposed on the chip 25. A pressure plate 21 connected to the positioning part is disposed on the copper foil 27. The etched silicon wafer 28 is used to position the relative positions of the heat sink 24 and the chip 25.

[0035] The specific assembly process steps are as follows: Place the chip 25 to be soldered on the heat sink 24, and assemble the heat sink 24, ceramic sheet 26, copper foil 27, and pressure plate 21 to form the chip assembly to be soldered. Then, fix the chip assembly to be soldered to the positioning part on the limiting boss 15 with screws. Then, adjust the internal hexagonal head screw I14 to complete the disassembly of the clamping plate 13. Place the etched silicon wafer 28 on the boss 12 and adjust its position. Then, adjust the internal hexagonal head screw I14 to complete the installation of the clamping plate 13. The etched silicon wafer 28 is fixed and tightly assembled with the chip 25 and the heat sink 24. Finally, wait for soldering.

[0036] In summary, the structural design of the silicon wafer positioning groove module enables the chip and heat sink to achieve better positional accuracy, facilitating chip protrusion positioning and controlling the protrusion distance of the chip's emitting surface within 5µm. This effectively prevents solder from blocking the emitting point after soldering, thus avoiding laser burnout and improving the yield of laser packaging. The adjustment assembly module ensures that the probe fixture has a high degree of positional freedom, enabling it to quickly respond to changes in workpiece position and accurately clamp the workpiece. It also ensures that the soldering between components is relatively independent, preventing the placement of the next component from affecting the movement of the previous component, thereby improving the quality of the finished laser packaging.

[0037] In another embodiment of the present invention, the tilt angle of the worktable is 30°, the tilt angle of the boss is 120°, and the included angle between the contact surfaces of the worktable and the boss is 90°.

[0038] Please see Figure 1-7 In another embodiment of the present invention, the adjustment assembly module includes a probe clamp, a first adjustment assembly mechanism 3, and a second adjustment assembly mechanism 4. One of the second adjustment assembly mechanisms 4 is installed on the top of the base away from the right-angle clamping part, and the second adjustment assembly mechanism 4 drives the probe clamp installed at its output end to rotate. A plurality of the first adjustment assembly mechanisms 3 are installed in pairs opposite to each other on both sides of the etching silicon wafer positioning groove module. The first adjustment assembly mechanism 3 drives the probe clamp installed at its output end to rotate to position the etching silicon wafer positioning groove module 2.

[0039] There are four first adjustment and assembly mechanisms 3, which are installed in pairs on both sides of the etched silicon wafer positioning groove module 2. The probe clamps installed at the output ends of the first adjustment and assembly mechanism 3 and the second adjustment and assembly mechanism 4 are probe clamp I36 and probe clamp II47, respectively. The parts of the chip group to be soldered are arranged in sequence and clamped by the probe clamps 36 on both sides of the etched silicon wafer positioning groove module. By rotating the first adjustment and assembly mechanism 3, the probe clamp I36 is displaced, thereby controlling the positional accuracy of the corresponding chip group parts to be soldered, so that each part of the chip group to be soldered is quickly and accurately fixed in the soldering position. After the clamping plate is unloaded and the etched silicon wafer 28 is clamped, the clamping plate is installed to fix the etched silicon wafer 28. The etched silicon wafer 28 is used to position the chip and heat sink of the chip group to be soldered. By rotating the second adjustment and assembly mechanism 4, the probe clamp II47 is displaced, so that the etched silicon wafer 28 is quickly and accurately positioned to position the chip and heat sink of the chip group to be soldered. Wait for the soldering to begin.

[0040] It should be noted that the number of the first adjustment assembly mechanism 3 in this invention is not limited to four, but can also be five or six. Its installation method and working principle are as described above. This embodiment has given relevant technical instructions. Those skilled in the art can achieve the desired function based on the relevant description, or achieve the required technical characteristics through similar technologies. It will not be described in detail here.

[0041] Please see Figure 5-7 In another embodiment of the present invention, both the first adjustment assembly mechanism 3 and the second adjustment assembly mechanism 4 include a worm, a turbine, a turbine pin, and a bracket. The worm and the turbine pin are mounted perpendicularly to each other on the bracket. The turbine and the probe clamp, which mesh with the worm, are coaxially mounted on the turbine pin. The worm drives the probe clamp to rotate through the turbine. The first adjustment assembly mechanism 3 or the second adjustment assembly mechanism 4 also includes a worm handle, which is mounted on the top of the worm.

[0042] Specifically, the first adjustment and assembly mechanism 3 includes a worm gear, a turbine, a turbine pin, a bracket, and a worm handle, which are respectively designated as worm gear I32, turbine I33, turbine pin I34, bracket I35, and worm handle I31. The probe holder I36 and the bracket I35 are mounted together by the turbine pin I34 and an internal hexagon socket head cap screw II310. The turbine I33 is mounted on the turbine pin I34. The worm handle I31 is mounted inside the worm gear I32 by an internal hexagon socket head cap set screw I39. The worm gear I32 is fixed on the bracket I35. The position movement of the probe holder I36 is achieved by the transmission of the worm gear I32 and the turbine I33 driven by the worm handle I31, ensuring that the probe holder I36 has a high degree of positional freedom and realizing the precise clamping of each component of the chip assembly to be soldered. It can quickly respond to changes in the position of the workpiece and accurately clamp the workpiece.

[0043] Furthermore, each of the first adjustment assembly mechanisms is connected to a rotary assembly mechanism 5 via an intermediate transmission group. The rotary assembly mechanism 5 drives the bracket I35 to rotate via the intermediate transmission group. The intermediate transmission group includes a driven wheel shaft 38 and a driven wheel 37. The driven wheel 37 is mounted on the bottom of the bracket I35 via the driven wheel shaft 38, and the bracket I35 is rotatably mounted on the base via the driven wheel shaft 38. The bracket I35 and the driven wheel shaft 38 are fixedly connected by cross-slot countersunk screws I311 and cross-slot pan head screws I312. The driven wheel 37 is driven by the rotary assembly mechanism 5. Mechanism 5 drives the bracket I35 to rotate via the driven wheel 37; the rotating assembly mechanism includes a drive wheel shaft, a spur gear handle 51, and a drive wheel 52. The spur gear handle 51 and the drive wheel 52 are coaxially mounted on the base via the drive wheel shaft. The spur gear handle 51 and the drive wheel 52 are connected and fixed by an internal hexagonal flat-end set screw III53. The drive wheel 52 meshes with the intermediate transmission group; the rotation of the spur gear handle 51 drives the drive wheel 52 to rotate, the rotation of the drive wheel 52 drives the intermediate transmission group to rotate, and the rotation of the intermediate transmission group drives the bracket I35 to rotate; thus ensuring a high degree of freedom of movement for the probe holder I36.

[0044] The second adjustment assembly mechanism 4 includes a worm gear, a turbine, a turbine pin, a bracket, and a worm gear handle, which are respectively designated as worm gear II43, turbine II44, turbine pin II45, bracket II46, and worm gear handle II42. The probe clamp II47 and the bracket II46 are mounted together by the turbine pin II45 and an internal hexagon socket head cap screw III49. The turbine II44 is mounted on the turbine pin II45, and the worm gear handle II42 is installed inside the worm gear II43 by an internal hexagon socket head cap set screw II48. The worm gear II43 is fixed on the bracket II46, and the bracket II46 is mounted on the base via an L-shaped bracket 41. The L-shaped bracket 41 is connected to the bracket II46 via a cross-slot countersunk screw II410 and a cross-slot pan head screw II411. The worm gear handle II42 drives the worm gear II43 and the worm wheel II44 to move the probe clamp II47, ensuring that the probe clamp II47 has a high degree of positional freedom and achieves precise clamping. It can quickly respond to changes in the position of the workpiece and accurately clamp the workpiece.

[0045] The working principle of this invention is as follows: The top of the base is provided with a worktable 11 and a boss 12. The top surface of the worktable 11 is perpendicular to the surface of the boss 12 near the etching silicon wafer positioning groove module. A clamping plate 13 is installed on the top surface of the worktable 11, forming a right-angle clamping part with the boss 12. Further, the clamping plate 13 is installed on the worktable by a hexagonal head screw I14 to fix the etching silicon wafer 28. The degree of fixation of the clamping plate 13 on the etching silicon wafer 28 is adjusted by adjusting the hexagonal head screw I14. The etching silicon wafer positioning groove module 2 includes a limiting boss 15, a pressure plate 21, and fasteners. The two limiting bosses 15 are installed on the worktable at intervals by fasteners to form a positioning part. The pressure plate 21 constrains the chip group to be soldered in the positioning part by fasteners. The adjustment assembly module adjusts the constraint state between the pressure plate and the positioning part by fasteners to make the chip group to be soldered and the etching silicon wafer form a tight assembly.

[0046] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the disclosure in the specification and embodiments. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the claims.

[0047] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A high-power laser bar package vacuum reflow furnace positioning clamp device, characterized in that, The utility model relates to a kind of silicon wafer welding device, including: Base, the top of the base has a right-angle clamping part for clamping etching silicon wafer; Etching silicon wafer positioning slot module mounted in right-angle clamping part, for clamping chip group to be welded and making chip group to be welded abut etching silicon wafer; And adjustment assembly module is used for positioning etching silicon wafer positioning slot module; Wherein the adjustment assembly module includes: Probe clamp; First adjustment assembly mechanism; Second adjustment assembly mechanism, one of the second adjustment assembly mechanism is mounted in the top of base away from the end of right-angle clamping part, the second adjustment assembly mechanism drives the rotation of probe clamp mounted in its output end;Multiple first adjustment assembly mechanisms are oppositely mounted on both sides of etching silicon wafer positioning slot module, and the first adjustment assembly mechanism drives the rotation of probe clamp mounted in its output end to position etching silicon wafer positioning slot module;Wherein: The first adjustment assembly mechanism, second adjustment assembly mechanism all include worm, turbine, turbine pin shaft and support, the worm and turbine pin shaft are perpendicularly mounted on the support, the turbine meshing with the worm, probe clamp is coaxially mounted on turbine pin shaft, the worm drives the rotation of probe clamp through turbine; The top of the base is provided with workbench and boss, the top surface of the workbench and the surface of boss close to the side of etching silicon wafer positioning slot module are at right angles, the top surface of the workbench is provided with clamping plate to form right-angle clamping part with boss; The etching silicon wafer positioning slot module includes limiting boss, pressing plate and fastener, two limiting bosses are spaced apart and mounted on workbench to form positioning part by fastener, the pressing plate constrains chip group to be welded in positioning part by fastener, and the adjustment assembly module adjusts the constraint state of pressing plate and positioning part by fastener; The chip group to be welded includes etching silicon wafer, heat sink, chip arranged on heat sink, the heat sink is mounted on positioning part through substrate, and ceramic sheet is further arranged on the substrate, copper foil is arranged on the top of ceramic sheet and chip, ceramic pressing sheet for pressing chip is arranged on chip, pressing plate connected with positioning part is arranged on copper foil, and the etching silicon wafer is used for positioning the relative position of heat sink and chip.

2. The positioning fixture device for high-power laser bar package vacuum reflow furnace according to claim 1, characterized in that, The inclination angle of the workbench is 30°, the inclination angle of the boss is 120°, and the included angle of the contact surface of the workbench and the boss is 90°.

3. The positioning fixture device for high-power laser bar package vacuum reflow oven according to claim 1, wherein, The first adjustment assembly mechanism or the second adjustment assembly mechanism further includes worm handle, and the worm handle is mounted at the top end of the worm.

4. The positioning fixture device for high-power laser bar package vacuum reflow furnace according to claim 3, characterized in that, Each first adjustment assembly mechanism is connected with a rotating assembly through an intermediate transmission group, and the rotating assembly drives the support to rotate through the intermediate transmission group.

5. The high power laser bar package vacuum reflow oven positioning fixture apparatus according to claim 4, wherein, The rotating assembly includes a driving shaft, a spur gear handle and a driving wheel, the spur gear handle and the driving wheel are coaxially mounted on the base through the driving shaft, and the driving wheel is engaged with the intermediate transmission group;The spur gear handle drives the driving wheel to rotate, and the driving wheel drives the intermediate transmission group to rotate.

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