Hot air drying tunnel furnace for preventing PCB (Printed Circuit Board) from warping and deforming

Abstract

The invention relates to the technical field of drying tunnel furnaces, and discloses a hot air drying tunnel furnace capable of preventing PCB (Printed Circuit Board) warping deformation, which comprises a rack and a mesh conveying belt, a drying furnace is arranged on the rack, a slow cooling bin is arranged at an outlet of the drying furnace, a preheating mechanism is arranged at a hot air exhaust port of the drying furnace, and the mesh conveying belt is arranged on the rack. The slow cooling bin is provided with a heat preservation assembly and a driving assembly. According to the invention, through the use of the preheating mechanism, high-temperature hot air discharged by the drying furnace enters the heat exchange assembly through the discharge pipe, heat exchange is completed between the high-temperature hot air and cold air introduced by the air inlet pipe in the heat exchange pipe, a spiral sheet rotates to enhance the heat exchange efficiency, and a filter screen intercepts impurities to avoid PCB pollution; the first pump body and the second pump body convey preheated gradient temperature air to the two sets of spraying cavities of the slow cooling bin through hoses, then the preheated gradient temperature air is sprayed to the surface of the PCB, slow cooling of the PCB is achieved, the situation of edge warping in the PCB drying process is reduced, and the drying effect on the PCB is improved.

Description

Technical Field

[0001] This invention relates to the field of drying tunnel oven technology, and in particular to a hot air drying tunnel oven for preventing PCB board warping. Background Technology

[0002] PCB boards are widely used in the field of communication electronics. During the production process of PCB boards, hot air drying tunnel ovens are used to dry the PCB boards to remove surface moisture, cure solder resist / conformal coating, and pre-bake solder paste, ensuring the electrical insulation, solder joint reliability, and dimensional stability of the PCB boards. It is a key piece of equipment connecting the PCB board printing, coating, welding, and assembly processes.

[0003] Currently, existing hot air drying tunnel ovens lack a gradual temperature control design at the outlet, relying solely on simple protective baffles to isolate the internal and external environments. After drying, the PCB board is directly exposed to room temperature from a high temperature, resulting in a drastic temperature change and strong thermal shock. The rapid cooling of the PCB board exacerbates the asynchronous shrinkage of the substrate and copper foil, leading to edge warping during the PCB board drying process. Therefore, a hot air drying tunnel oven designed to prevent PCB board warping is proposed to address these issues. Summary of the Invention

[0004] To overcome the above shortcomings, the present invention provides a hot air drying tunnel oven for preventing PCB board warping, which aims to improve the problem of edge warping caused by the lack of gradual temperature control design at the outlet of the hot air drying tunnel oven in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a hot air drying tunnel oven for preventing PCB board warping, comprising a frame and a mesh conveyor belt, a drying oven mounted on the frame, a slow cooling chamber located at the outlet of the drying oven, a preheating mechanism located at the hot air outlet of the drying oven, and a heat preservation component and a driving component mounted on the slow cooling chamber, wherein the preheating mechanism includes: A heat exchange assembly, which is mounted on a drying oven via a support member; A first connecting pipe is connected to a heat exchange component. A second connecting pipe is connected to the heat exchange component. The first connecting pipe is connected to a first pump body, and the second connecting pipe is connected to a second pump body.

[0006] As a further description of the above technical solution: The heat exchange assembly includes a discharge pipe, a heat exchange tube, a spiral blade, and an air inlet pipe. The discharge pipe is connected to the hot air outlet of the drying oven. The heat exchange tube is installed in the discharge pipe and is rotatably connected to the spiral blade. The air inlet pipe is connected to the heat exchange tube. Both the first connecting pipe and the second connecting pipe are connected to the heat exchange tube.

[0007] As a further description of the above technical solution: A filter screen is installed at the end of the air inlet pipe away from the heat exchanger tube.

[0008] As a further description of the above technical solution: A spray chamber is slidably connected to the inner wall of the top of the slow cooling chamber. A flexible hose is connected to the outer wall of the spray chamber. Two sets of spray chambers and flexible hoses are provided, and the two sets of flexible hoses are respectively connected to pump body one and pump body two. A guide is fixedly connected to the inner wall of the slow cooling chamber.

[0009] As a further description of the above technical solution: A detection sensor is fixedly installed in the inner wall of the slow cooling chamber to detect whether the PCB board has been transported into the slow cooling chamber.

[0010] As a further description of the above technical solution: The guide component includes a guide rod and a guide sleeve. The guide rod is fixedly connected in the slow cooling chamber, and the guide sleeve is slidably connected to the guide rod. The guide sleeve is fixedly connected to the outer wall of the spray chamber.

[0011] As a further description of the above technical solution: The heat preservation component includes a baffle, a connecting shaft, a fixing block, a worm gear, a wear-resistant ring, and a worm. The baffle is fixedly connected to the connecting shaft, the fixing block is fixedly connected to the top of the slow cooling chamber, the connecting shaft passes through the fixing block and is rotatably connected to the fixing block, the worm gear is rotatably connected to the end of the connecting shaft, the wear-resistant ring is slidably connected to the connecting shaft, the fixing block and the wear-resistant ring are elastically connected by a compression spring, and the worm gear meshes with the worm.

[0012] As a further description of the above technical solution: A limit block is fixedly connected to the top of the slow cooling chamber to limit the rotation angle of the baffle.

[0013] As a further description of the above technical solution: The drive assembly includes a rotating shaft, a drive module, a hinge rod, and a connecting rod. The rotating shaft is fixedly connected to a worm gear and is driven by the drive module. The rotating shaft has a curved section that is hinged to the hinge rod. The end of the hinge rod away from the curved section is hinged to the connecting rod. The connecting rod is hinged to the outer wall of the spray chamber and passes through the outer wall of the slow cooling chamber and is sealed to the outer wall of the slow cooling chamber.

[0014] As a further description of the above technical solution: The drive module consists of a motor and a reducer. The reducer is fixedly installed on the outer wall of the slow cooling chamber. The output end of the reducer is fixedly connected to the rotating shaft. The motor is used to drive the reducer.

[0015] The present invention has the following beneficial effects: 1. In this invention, through the use of a preheating mechanism, the high-temperature hot air discharged from the drying oven enters the heat exchange component through the discharge pipe, and completes heat exchange with the cold air introduced by the air inlet pipe in the heat exchange tube. The rotation of the spiral blades enhances the heat exchange efficiency, and the filter screen intercepts impurities to avoid PCB board contamination. Pump body one and pump body two deliver the preheated gradient temperature air through hoses to two sets of spray chambers in the slow cooling chamber, and then spray it onto the surface of the PCB board to achieve slow cooling of the PCB board. Since the connecting pipe one and the connecting pipe two are set at different positions in the heat exchange tube, the hot air sprayed from the two sets of spray chambers has different temperatures, which achieves gradual slow cooling of the PCB board, reduces the occurrence of edge warping during the PCB board drying process, and improves the drying effect of the PCB board.

[0016] 2. In this invention, by using the heat preservation component, when the detection sensor detects that the PCB board is being transported to the slow cooling chamber, the drive module drives the rotating shaft to rotate. On one hand, this drives the worm gear to mesh with the worm wheel, causing the connecting shaft to rotate and open the baffle. The limit block restricts the rotation angle of the baffle to avoid excessive opening and closing. In this way, heat loss is reduced when the PCB board is not being transported out of the slow cooling chamber, the temperature stability inside the drying oven is improved, and the PCB board can be stably dried with hot air. This further reduces the possibility of edge warping during the PCB board drying process and improves the drying effect of the PCB board.

[0017] 3. In this invention, by using the heat preservation component and the driving component, after the baffle abuts against the limiting block, the worm continues to drive the worm wheel to rotate, and the worm wheel will rotate relative to the wear-resistant ring. During this process, the rotating shaft continues to rotate, and its curved part drives the hinge rod to move, so that the connecting rod drives the spray cavity to slide back and forth, so that the preheated air evenly covers the surface of the PCB board and improves the gradual cooling effect of the PCB board. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of a hot air drying tunnel oven for preventing PCB board warping proposed in this invention. Figure 2 This is a partial cross-sectional view of a hot air drying tunnel oven for preventing PCB board warping proposed in this invention. Figure 3 This invention proposes a hot air drying tunnel oven for preventing PCB board warping. Figure 2 Schematic diagram of structure A in the middle; Figure 4 This is a partial three-dimensional structural diagram of a hot air drying tunnel oven for preventing PCB board warping proposed in this invention. Figure 1 ; Figure 5 This is a partial three-dimensional structural diagram of a hot air drying tunnel oven for preventing PCB board warping proposed in this invention. Figure 2 ; Figure 6 This invention proposes a hot air drying tunnel oven for preventing PCB board warping. Figure 5 Schematic diagram of structure B in the middle; Figure 7 This is a partial three-dimensional structural diagram of a hot air drying tunnel oven for preventing PCB board warping proposed in this invention. Figure 3 ; Figure 8 This invention proposes a hot air drying tunnel oven for preventing PCB board warping. Figure 7 Schematic diagram of the C-structure.

[0019] Legend: 1. Frame; 2. Mesh conveyor belt; 3. Drying oven; 4. Slow cooling chamber; 5. Preheating mechanism; 6. Heat preservation components; 7. Drive components; 41. Spray chamber; 42. Hose; 43. Guide component; 44. Detection sensor; 45. Limiting block; 431. Guide rod; 432. Guide sleeve; 51. Heat exchanger assembly; 52. Support component; 53. Connecting pipe one; 54. Connecting pipe two; 55. Pump body one; 56. Pump body two; 511. Discharge pipe; 512. Heat exchanger tube; 513. Spiral blade; 514. Inlet pipe; 61. Baffle; 62. Connecting shaft; 63. Fixing block; 64. Worm gear; 65. Wear ring; 66. Worm; 71. Shaft; 72. Reducer; 73. Motor; 74. Bending section; 75. Hinge rod; 76. Connecting rod. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Reference Figures 1-3 The present invention provides an embodiment of a hot air drying tunnel oven for preventing PCB board warping, comprising a frame 1 and a mesh conveyor belt 2. A drying oven 3 is provided on the frame 1. By placing the PCB board on the mesh conveyor belt 2, the mesh conveyor belt 2 can transport the PCB board to the drying oven 3, thereby achieving heating and drying in the drying oven 3. A slow cooling chamber 4 is provided at the outlet of the drying oven 3, and a preheating mechanism 5 is provided at the hot air outlet of the drying oven 3. A heat preservation component 6 and a drive component 7 are provided on the slow cooling chamber 4.

[0022] The preheating mechanism 5 includes a heat exchange component 51 and a connecting pipe 53. The heat exchange component 51 is mounted on the drying oven 3 via a support 52. The connecting pipe 53 is connected to the heat exchange component 51. A connecting pipe 54 is connected to the heat exchange component 51. The connecting pipe 53 is connected to a pump body 55, and the connecting pipe 54 is connected to a pump body 56. By activating the pump body 55 and the pump body 56, the air that is being heated by the heat exchange component 51 can be drawn into the connecting pipe 53 and the connecting pipe 54.

[0023] The heat exchange assembly 51 includes an exhaust pipe 511, a heat exchange tube 512, a spiral blade 513, and an inlet pipe 514. The exhaust pipe 511 is connected to the hot air outlet of the drying oven 3. The heat exchange tube 512 is installed in the exhaust pipe 511 and is rotatably connected to the spiral blade 513. The inlet pipe 514 is connected to the heat exchange tube 512. A filter screen is installed at the end of the inlet pipe 514 away from the heat exchange tube 512. The connecting pipe 1 53 and the connecting pipe 2 54 are both connected to the heat exchange tube 512. When hot air and water vapor are discharged from the exhaust pipe 511, the outside air can be filtered by the filter screen before being added to the heat exchange tube 512 through the inlet pipe 514. It can exchange heat with the cold air in the heat exchange tube 512. Under the action of the spiral blade 513, the flow rate of the hot air is slowed down, the heat exchange effect is improved, and the outside cold air is preheated.

[0024] Reference Figures 2-4 The top inner wall of the slow cooling chamber 4 is slidably connected to a spray chamber 41, and a hose 42 is connected to the outer wall of the spray chamber 41. There are two sets of spray chamber 41 and hose 42, and the two sets of hose 42 are respectively connected to pump body 1 55 and pump body 2 56. A guide 43 is fixedly connected to the inner wall of the slow cooling chamber 4. Pump body 1 55 and pump body 2 56 deliver preheated gradient temperature air to the two sets of spray chambers 41 in the slow cooling chamber 4 through the hose 42, and then spray it onto the surface of the PCB board to achieve slow cooling of the PCB board. Since the connecting pipe 1 53 and the connecting pipe 2 54 are set at different positions on the heat exchange pipe 512, the hot air sprayed from the two sets of spray chambers 41 has a different temperature, which achieves gradual slow cooling of the PCB board, reduces the occurrence of edge warping during the PCB board drying process, and improves the drying effect of the PCB board.

[0025] Reference Figures 4-6A detection sensor 44 is fixedly installed in the inner wall of the slow cooling chamber 4 to detect whether the PCB board has been conveyed into the slow cooling chamber 4. A limit block 45 is fixedly connected to the top of the slow cooling chamber 4 to limit the rotation angle of the baffle 61. The heat preservation component 6 includes a baffle 61, a connecting shaft 62, a fixing block 63, a worm gear 64, a wear-resistant ring 65, and a worm 66. The baffle 61 is fixedly connected to the connecting shaft 62, the fixing block 63 is fixedly connected to the top of the slow cooling chamber 4, the connecting shaft 62 passes through the fixing block 63 and is rotatably connected to the fixing block 63, the worm gear 64 is rotatably connected to the end of the connecting shaft 62, the wear-resistant ring 65 is slidably connected to the connecting shaft 62, and the fixing block 63 is rotatably connected to the worm gear 64. The grinding ring 65 is elastically connected by a compression spring, and the worm wheel 64 meshes with the worm 66. When the detection sensor 44 detects that the PCB board is being transported to the slow cooling chamber 4, the drive assembly 7 drives the worm 66 to rotate, which in turn drives the worm wheel 64 to rotate, causing the connecting shaft 62 to rotate and open the baffle 61. The limit block 45 limits the rotation angle of the baffle 61 to prevent excessive opening and closing. In this way, heat loss is reduced when the PCB board is not being transported out of the slow cooling chamber 4, the temperature stability inside the drying oven 3 is improved, and the PCB board can be stably dried with hot air. This further reduces the possibility of edge warping during the PCB board drying process and improves the drying effect of the PCB board.

[0026] Reference Figures 7-8 The guide component 43 includes a guide rod 431 and a guide sleeve 432. The guide rod 431 is fixedly connected in the slow cooling chamber 4, and the guide sleeve 432 is slidably connected to the guide rod 431. The guide sleeve 432 is fixedly connected to the outer wall of the spray chamber 41. The drive assembly 7 includes a rotating shaft 71, a drive module, a hinge rod 75, and a connecting rod 76. The rotating shaft 71 is fixedly connected to the worm gear 66. The rotating shaft 71 is driven by the drive module. The rotating shaft 71 is provided with a bent portion 74, and the bent portion 74 is hinged to the hinge rod 75. The end of the hinge rod 75 away from the bent portion 74 is hinged to the connecting rod 76. The connecting rod 76 is hinged to the outer wall of the spray chamber 41 and passes through the outer wall of the slow cooling chamber 4 and is sealed to the outer wall of the slow cooling chamber 4. The module consists of a motor 73 and a reducer 72. The reducer 72 is fixedly installed on the outer wall of the slow cooling chamber 4. The output end of the reducer 72 is fixedly connected to the rotating shaft 71. The motor 73 is used to drive the reducer 72. By starting the motor 73 to drive the reducer 72, the rotating shaft 71 rotates, which drives the worm gear 66 to rotate. After the baffle 61 abuts against the limit block 45, the worm gear 66 continues to drive the worm wheel 64 to rotate. During this process, the worm wheel 64 will rotate relative to the wear-resistant ring 65. During this process, the rotating shaft 71 continues to rotate, and its bent part 74 drives the hinge rod 75 to move, so that the connecting rod 76 drives the spray chamber 41 to slide back and forth, so that the preheated air evenly covers the surface of the PCB board and improves the gradual slow cooling effect of the PCB board.

[0027] It should be noted that the above electrical components are all existing technology products. Those skilled in the art should select, install, and complete the circuit debugging work according to the needs of use to ensure that all electrical appliances can work normally. The components are all general standard parts or parts known to those skilled in the art. Their structure and principle can be learned by those skilled in the art through technical manuals or conventional experimental methods. No specific restrictions are made here. The standard parts used in this application can all be purchased from the market. The specific connection methods of each part are all connected by conventional means such as riveting and welding that are mature in the prior art. The standard parts are all conventional models in the prior art. In addition, the circuit connection adopts conventional connection methods in the prior art.

[0028] Working principle: When in use, the equipment is first started for preheating. The drying oven 3 begins to heat up to the preset drying temperature. At the same time, pump body 1 55 and pump body 2 56 are started, and the preheating mechanism 5 enters the working state. The hot air and water vapor generated by the drying oven 3 enter the discharge pipe 511 of the heat exchange component 51 through the hot air outlet. The outside cold air enters the heat exchange tube 512 after being filtered by the filter screen of the air inlet pipe 514. The spiral blades 513 inside the heat exchange tube 512 rotate to slow down the flow rate of the hot air and increase the contact area for heat exchange, thereby realizing the preheating of the cold air. Since the connecting pipe 1 53 and the connecting pipe 2 54 are connected at different positions on the heat exchange tube 512, the preheated air collected by the two sets of pipes forms a temperature gradient.

[0029] The PCB board to be dried is placed steadily on the perforated conveyor belt 2. The perforated conveyor belt 2 starts and conveys the PCB board to the drying oven 3 at a uniform speed. The drying oven 3 dries the PCB board with hot air, completing the removal of moisture, curing of solder resist / conformal coating or pre-baking of solder paste. When the PCB board is dried and conveyed to the inlet of the slow cooling chamber 4, the detection sensor 44 on the inner wall of the slow cooling chamber 4 detects the PCB board signal and immediately triggers the start of the drive assembly 7: the motor 73 drives the reducer 72 to run, the output end of the reducer 72 drives the rotating shaft 71 to rotate, and the worm gear 66 fixedly connected to the rotating shaft 71 rotates synchronously. The worm gear 66 meshes with and drives the worm wheel 64, which in turn drives the connecting shaft 62 to rotate around the fixed block 63. The connecting shaft 62 drives the baffle 61 to open until the baffle 61 abuts against the limit block 45 at the top of the slow cooling chamber 4 to prevent excessive opening and closing.

[0030] The rotating shaft 71 rotates continuously, and the curved part 74 of its outer wall drives the hinge rod 75 to reciprocate. The hinge rod 75 pulls the connecting rod 76 to slide along the outer wall of the slow cooling chamber 4. The connecting rod 76 drives the spray chamber 41 to slide smoothly back and forth along the guide rod 431 and guide sleeve 432 of the guide member 43, so that the spraying range of the spray chamber 41 fully covers the surface of the PCB board. At the same time, pump body 1 55 and pump body 2 56 deliver two sets of preheated air with different temperature gradients to the two sets of spray chambers 41 through the corresponding hoses 42. The spray chambers 41 spray the preheated air evenly onto the surface of the PCB board, realizing a gradual slow cooling from high temperature to room temperature.

[0031] During the slow cooling process of the PCB board, the baffle 61 of the heat preservation component 6 remains open, working in conjunction with the sealed structure of the slow cooling chamber 4 to maintain a stable temperature environment inside the chamber and prevent the influx of ambient air from disrupting the gradual temperature control effect. When the PCB board has completely passed through the slow cooling chamber 4 and the detection sensor 44 has not detected the PCB board, the drive component 7 drives the rotating shaft 71 to reverse, causing the baffle 61 to close, reducing heat loss from the slow cooling chamber 4, and simultaneously the spray chamber 41 returns to its initial position. The perforated conveyor belt 2 uniformly conveys the slow-cooled PCB board out of the slow cooling chamber 4, completing one drying-slow cooling process. For batch processing, simply continue placing PCB boards to be processed onto the perforated conveyor belt 2, and the equipment will automatically repeat the above process to achieve continuous production.

[0032] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hot air drying tunnel oven for preventing PCB board warping, comprising a frame (1) and a mesh conveyor belt (2), characterized in that: A drying oven (3) is provided on the frame (1), a slow cooling chamber (4) is provided at the outlet of the drying oven (3), a preheating mechanism (5) is provided at the hot air outlet of the drying oven (3), and a heat preservation component (6) and a drive component (7) are provided on the slow cooling chamber (4). The preheating mechanism (5) includes: A heat exchange assembly (51) is mounted on the drying oven (3) via a support member (52); Connecting pipe one (53) is connected to heat exchange component (51). Connecting pipe two (54) is connected to heat exchange component (51). Connecting pipe one (53) is connected to pump body one (55). Connecting pipe two (54) is connected to pump body two (56).

2. The hot air drying tunnel oven for preventing PCB board warping and deformation according to claim 1, characterized in that: The heat exchange assembly (51) includes an exhaust pipe (511), a heat exchange tube (512), a spiral blade (513), and an air inlet pipe (514). The exhaust pipe (511) is connected to the hot air outlet of the drying oven (3). The heat exchange tube (512) is installed in the exhaust pipe (511) and is rotatably connected to the spiral blade (513). The air inlet pipe (514) is connected to the heat exchange tube (512). The first connecting pipe (53) and the second connecting pipe (54) are both connected to the heat exchange tube (512).

3. A hot air drying tunnel oven for preventing PCB board warping and deformation according to claim 2, characterized in that: A filter screen is provided at the end of the air inlet pipe (514) away from the heat exchange pipe (512).

4. The hot air drying tunnel oven for preventing PCB board warping and deformation according to claim 1, characterized in that: The top inner wall of the slow cooling chamber (4) is slidably connected to a spray chamber (41), and a hose (42) is connected to the outer wall of the spray chamber (41). The spray chamber (41) and the hose (42) are each provided with two sets, and the two sets of hoses (42) are respectively connected to pump body one (55) and pump body two (56). A guide (43) is fixedly connected to the inner wall of the slow cooling chamber (4).

5. A hot air drying tunnel oven for preventing PCB board warping and deformation according to claim 1, characterized in that: A detection sensor (44) is fixedly installed in the inner wall of the slow cooling chamber (4) to detect whether the PCB board is transported into the slow cooling chamber (4).

6. A hot air drying tunnel oven for preventing PCB board warping and deformation according to claim 4, characterized in that: The guide (43) includes a guide rod (431) and a guide sleeve (432). The guide rod (431) is fixedly connected in the slow cooling chamber (4), and the guide sleeve (432) is slidably connected to the guide rod (431). The guide sleeve (432) is fixedly connected to the outer wall of the spray chamber (41).

7. A hot air drying tunnel oven for preventing PCB board warping and deformation according to claim 4, characterized in that: The heat preservation component (6) includes a baffle (61), a connecting shaft (62), a fixing block (63), a worm gear (64), a wear-resistant ring (65), and a worm (66). The baffle (61) is fixedly connected to the connecting shaft (62). The fixing block (63) is fixedly connected to the top of the slow cooling chamber (4). The connecting shaft (62) passes through the fixing block (63) and is rotatably connected to the fixing block (63). The worm gear (64) is rotatably connected to the end of the connecting shaft (62). The wear-resistant ring (65) is slidably connected to the connecting shaft (62). The fixing block (63) and the wear-resistant ring (65) are elastically connected by a compression spring. The worm gear (64) meshes with the worm (66).

8. A hot air drying tunnel oven for preventing PCB board warping and deformation according to claim 7, characterized in that: The top of the slow cooling chamber (4) is fixedly connected to a limiting block (45) to limit the rotation angle of the baffle (61).

9. A hot air drying tunnel oven for preventing PCB board warping and deformation according to claim 7, characterized in that: The drive assembly (7) includes a rotating shaft (71), a drive module, a hinge rod (75), and a connecting rod (76). The rotating shaft (71) is fixedly connected to the worm gear (66). The rotating shaft (71) is driven by the drive module. The rotating shaft (71) is provided with a bent part (74), and the bent part (74) is hinged to the hinge rod (75). The end of the hinge rod (75) away from the bent part (74) is hinged to the connecting rod (76). The connecting rod (76) is hinged to the outer wall of the spray chamber (41). The connecting rod (76) penetrates the outer wall of the slow cooling chamber (4) and is sealed to the outer wall of the slow cooling chamber (4).

10. A hot air drying tunnel oven for preventing PCB board warping and deformation according to claim 9, characterized in that: The drive module consists of a motor (73) and a reducer (72). The reducer (72) is fixedly installed on the outer wall of the slow cooling chamber (4). The output end of the reducer (72) is fixedly connected to the rotating shaft (71). The motor (73) is used to drive the reducer (72).

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