Mini LED substrate vacuum pressing machine and control method

Abstract

The invention relates to the technical field of circuit board production equipment, and discloses a Mini LED substrate vacuum laminating machine and a control method.The Mini LED substrate vacuum laminating machine comprises a machine shell, a plurality of heating plates, a laminating supporting assembly and a controller, the heating plates are arranged in a laminating cavity at intervals in the vertical direction, and the laminating supporting assembly is arranged in the machine shell; a heat conduction oil pipeline and an electric heating part are arranged in the heating plate, at least two U-shaped bent channels are formed in the heat conduction oil pipeline, oil inlet is controlled through an electric control valve, the heating plate is connected with a plurality of temperature control probes, the press fit supporting assembly comprises a main hydraulic cylinder and an auxiliary pressure maintaining mechanism, and a base of the auxiliary pressure maintaining mechanism is fixed to the output end of the main hydraulic cylinder. A sliding groove is formed in the upper end face of the base, a sliding block is arranged on the bottom face of the supporting plate, a guide inclined face of the sliding block is attached to an inclined face of a wedge block, the wedge block is connected with an auxiliary hydraulic cylinder, and the main hydraulic cylinder and the auxiliary hydraulic cylinder are connected to a hydraulic station. The electric control valve, the electric heating part, the temperature control probe and the hydraulic station are all electrically connected to the controller.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board production equipment, and in particular to a Mini LED substrate vacuum pressing machine and a control method. Background Art

[0002] MiniLED, also known as sub-millimeter light-emitting diode, has a single miniLED chip size of about 100 microns. Compared with traditional LEDs, miniLED has a smaller chip size and a larger light-emitting angle. Using miniLED for backlight display can achieve higher brightness, color gamut, and contrast. Combined with partition display technology, it can achieve ultra-high-definition display. At present, miniLED backlight sources have gradually penetrated into various fields, such as large-size TVs, notebooks, tablets, etc. With the increase in application demand, the market potential of miniLED is huge.

[0003] In the related technology, Mini LED substrates are usually produced using a vacuum pressing machine to press the base plate and the copper plate together. Due to the small size of the miniLED chip, higher performance requirements are placed on the substrate. The thermal stability and pressing force stability of the existing vacuum pressing machine cannot meet production requirements and need to be improved. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a Mini LED substrate vacuum pressing machine that can accurately control the temperature and improve the stability of the pressure to meet the production requirements of the Mini LED substrate.

[0005] The present invention also proposes a control method applied to the above-mentioned Mini LED substrate vacuum pressing machine.

[0006] According to the first aspect of the present invention, a Mini LED substrate vacuum pressing machine includes a casing, a plurality of heating plates, a pressing support assembly and a controller, wherein a pressing cavity is formed inside the casing, a movable door body is provided on the front side of the casing to open or close the pressing cavity, and the pressing cavity is connected to a vacuum pump through a pipeline; a plurality of heating plates are arranged in the pressing cavity at intervals along the vertical direction, the heating plates are slidably connected to the casing, a heat transfer oil pipeline and an electric heating component are provided inside the heating plate, the heat transfer oil pipeline forms at least two U-shaped curved channels, the electric heating component fills the area outside the heat transfer oil pipeline, an electric control valve is provided at the inlet of the heat transfer oil pipeline, a plurality of temperature control probes are connected to the heating plate, and the plurality of temperature control probes are distributed at intervals along the circumference of the heating plate; the pressing support assembly is provided in the pressing cavity. The bottom surface of the closing cavity, the pressing support assembly includes a main hydraulic cylinder and an auxiliary pressure-maintaining mechanism, the main hydraulic cylinder is arranged vertically, and the auxiliary pressure-maintaining mechanism includes a base, a support plate and a wedge block, the base is fixed to the output end of the main hydraulic cylinder, the upper end surface of the base is provided with a slide groove, the bottom surface of the support plate is provided with a slider, the slider and the wedge block can both slide in the slide groove, the end of the slider is provided with a guide inclined surface, the inclined surface of the wedge block fits the guide inclined surface, the wedge block is connected with an auxiliary hydraulic cylinder, the auxiliary hydraulic cylinder is fixed to the base, the lowest heating plate is fixed to the top surface of the support plate, the main hydraulic cylinder and the auxiliary hydraulic cylinder are connected to the hydraulic station; the electric control valve, the electric heating component, the temperature control probe and the hydraulic station are all electrically connected to the controller.

[0007] The Mini LED substrate vacuum pressing machine according to the first aspect of the present invention has at least the following beneficial effects: A set of base plates and copper plates are placed on each heating plate, the door is closed and the pressing chamber is vacuumed by the vacuum pumping equipment. The controller controls the electric control valve to open, and the heat transfer oil enters the heat transfer oil pipeline of the heating plate to increase the temperature of the heating plate. The controller controls the electric heating component to start, raises the temperature of the heating plate to the set temperature and maintains it within the set temperature range. Then the controller controls the hydraulic station to move, and the main hydraulic cylinder pushes the auxiliary pressure holding mechanism and the bottom heating plate to rise, so that multiple heating plates are stacked and clamp multiple sets of base plates and copper plates. Then the auxiliary hydraulic cylinder pushes the wedge block to move, and uses the cooperation of the inclined surface to push the support plate up to increase the pressing force and pressure holding. The heating method using a combination of heat transfer oil and electric heating components is conducive to accurate temperature control, improves the pressing force and the stability of the pressing force through the auxiliary pressure holding mechanism, and improves the performance of the substrate after pressing to meet the production needs of Mini LED.

[0008] According to some embodiments of the first aspect of the present invention, the heating plate has two electric heating components, and the two electric heating components are distributed on both sides of the thermal oil pipeline.

[0009] According to some embodiments of the first aspect of the present invention, the electric heating component is provided with a U-shaped curved portion, and the curved portion is located in an inner area of ​​the curved channel.

[0010] According to some embodiments of the first aspect of the present invention, a plurality of pressure sensors are connected to the support plate, and the plurality of pressure sensors are distributed at intervals along the circumference of the support plate.

[0011] According to some embodiments of the first aspect of the present invention, the auxiliary pressure-maintaining mechanism has two wedge blocks, the two wedge blocks are distributed on both sides of the sliding block, and the sliding block is provided with two symmetrical guiding inclined surfaces.

[0012] According to some embodiments of the first aspect of the present invention, a support groove is provided on the upper end surface of the base, and the support groove is V-shaped. A support block is provided on the bottom surface of the support plate, and the shape of the support block matches the shape of the support groove, and the support block abuts against the inner wall of the support groove.

[0013] According to some embodiments of the first aspect of the present invention, a supporting portion is provided on the bottom surface of the support plate, the supporting portion includes a cylinder and a plurality of ribs evenly distributed circumferentially around the cylinder, the sliding block and the supporting block are an integral structure and are fixed to the supporting portion.

[0014] According to some embodiments of the first aspect of the present invention, a locking mechanism is connected to the outer wall of the casing, and the locking mechanism includes a locking seat and a wrench. The locking seat is detachably connected to the casing, and the locking seat is provided with a rotating shaft. A cam is provided at the end of the wrench, and the cam is rotatably connected to the rotating shaft. The cam can abut the side of the door body away from the casing.

[0015] According to the control method of the second aspect of the present invention, which is applied to the Mini LED substrate vacuum pressing machine described in the first aspect of the present invention, the control method comprises the following steps: S100, after the base plate and the copper plate are loaded, the controller controls the electric control valve to open, and the heat transfer oil enters the heat transfer oil pipeline of the heating plate to increase the temperature of the heating plate, and the controller controls the electric heating component to start, and the temperature of the heating plate is increased to a set temperature and maintained within a set temperature range; S200, the controller controls the hydraulic station to start, the hydraulic station drives the main hydraulic cylinder to start, and the main hydraulic cylinder pushes the auxiliary pressure-maintaining mechanism and the bottom heating plate to move upward, so that multiple heating plates are stacked and clamp multiple groups of bottom plates and copper plates; S300, the hydraulic station drives the auxiliary hydraulic cylinder of the auxiliary pressure-maintaining mechanism to start, and the auxiliary hydraulic cylinder pushes the wedge block to move in the slide groove, thereby pushing the slider and the support plate to rise, increasing the pressing force, and stabilizing the pressing force within a set range.

[0016] According to some embodiments of the second aspect of the present invention, in the step S100, the heat transfer oil raises the temperature of the heating plate to more than 95% of the set temperature, the electric heating component raises the temperature of the heating plate to the set temperature, the controller receives signals from multiple temperature control probes, and the controller accurately controls the temperature of the heating plate through an integrated PID controller.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments in conjunction with the accompanying drawings, in which: Figure 1 Schematic diagram of a Mini LED substrate vacuum pressing machine according to an embodiment of the first aspect of the present invention; Figure 2 This is an exploded schematic diagram of a Mini LED substrate vacuum pressing machine according to an embodiment of the first aspect of the present invention; Figure 3 It is a schematic diagram of an exploded view of an electric heating plate in some embodiments of the first aspect of the present invention; Figure 4 A schematic diagram of the distribution of the heat transfer oil pipeline and the electric heating components inside the electric heating plate in some embodiments of the first aspect of the present invention; Figure 5 Schematic diagram of the auxiliary pressure-maintaining mechanism in some embodiments of the first aspect of the present invention Figure 1 ; Figure 6 Schematic diagram of the auxiliary pressure-maintaining mechanism in some embodiments of the first aspect of the present invention Figure 2 ; Figure 7 is an exploded schematic diagram of a locking mechanism in some embodiments of the first aspect of the present invention; Figure 8 Schematic diagram of the sealing structure of the casing and the door body in some embodiments of the first aspect of the present invention.

[0019] The figures are as follows: Casing 100, pressing chamber 101, door body 110, sealing edge 111, locking mechanism 120, locking seat 121, wrench 122, rotating shaft 123, cam 124, sealing gasket 130; Heating plate 200, thermal oil pipeline 201, electric heating component 202; Pressing support assembly 300, main hydraulic cylinder 310, auxiliary pressure maintaining mechanism 320, base 321, support plate 322, wedge block 323, slide groove 324, slider 325, guide slope 3251, auxiliary hydraulic cylinder 326, support groove 327, support block 328, support part 329. DETAILED DESCRIPTION

[0020] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0021] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0022] In the description of the present invention, if there is a description of first and second, it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0023] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0024] It is understandable that, referring to Figures 1 to 6The embodiment of the first aspect of the present invention provides a Mini The LED substrate vacuum pressing machine includes a casing 100, a plurality of heating plates 200, a pressing support assembly 300 and a controller. A pressing chamber 101 is formed inside the casing 100. The pressing chamber 101 is a space for pressing the production substrate. In order to facilitate loading and unloading, a movable door body 110 is arranged on the front side of the casing 100 to open or close the pressing chamber 101. The pressing chamber 101 is connected to a vacuum pumping device through a pipeline. The pressing chamber 101 is vacuumed by the vacuum pumping device to obtain a set vacuum degree. It can be understood that the door body 110 usually adopts a sliding door, and a roller is arranged at the upper end of the casing 100. A slide rail is arranged at the upper end of the door body 110. The slide rail rolls on the roller to move the door body 110 to open or close the pressing chamber 101. A rack can be arranged on the side of the casing 100, and a plurality of rollers of corresponding heights are arranged on the rack. When the pressing chamber 101 is opened, the door body 110 can be moved to the rack for temporary storage.

[0025] like Figure 2 As shown, multiple heating plates 200 are arranged in the pressing cavity 101 at intervals along the vertical direction. The heating plates 200 are connected to the housing 100 in a sliding manner. A vertical slide rail may be provided on the inner wall of the housing 100. The heating plates 200 are connected to the slide rail through a sliding member. The sliding member can be maintained at any height of the slide rail. When subjected to thrust, it can move along the slide rail. A special snap member may also be provided to help the heating plates 200 to be positioned. Alternatively, a specially designed slide frame may be used. Multiple heating plates 200 are connected to the slide frame, and the slide frame is pushed into the pressing cavity 101 for use. A heat transfer oil pipeline 201 and an electric heating component 202 are provided inside the heating plate 200. The heat transfer oil pipeline 201 is used for the circulation of heat transfer oil. The heat transfer oil pipeline 201 is formed with at least two U-shaped curved channels, so that the flow path of the heat transfer oil is longer, which helps the heating plate 200 to heat up. The electric heating component 202 fills the area outside the heat transfer oil pipeline 201, which helps to balance the heating and increase the heating speed. An electric control valve is provided at the inlet of the heat transfer oil pipeline 201. The heating plate 200 is connected to a plurality of temperature control probes, and the plurality of temperature control probes are distributed at intervals along the circumference of the heating plate 200. The plurality of temperature control probes can be arranged in a circular ring, or in various shapes such as two circular rings, a rectangular ring, etc.

[0026] The pressing support assembly 300 is arranged on the bottom surface of the pressing chamber 101. The pressing support assembly 300 includes a main hydraulic cylinder 310 and an auxiliary pressure-maintaining mechanism 320. The main hydraulic cylinder 310 is arranged vertically. The auxiliary pressure-maintaining mechanism 320 includes a base 321, a support plate 322 and a wedge block 323. The base 321 is fixed to the output end of the main hydraulic cylinder 310. The upper end surface of the base 321 is provided with a slide groove 324. The bottom surface of the support plate 322 is provided with a slider 325. The slider 325 and the wedge block 323 are both It can slide in the slide groove 324, and a guide slope 3251 is provided at the end of the slider 325. The slope of the wedge block 323 fits the guide slope 3251. The wedge block 323 is connected to the auxiliary hydraulic cylinder 326, and the auxiliary hydraulic cylinder 326 is fixed to the base 321. The lowermost heating plate 200 is fixed to the top surface of the support plate 322. The main hydraulic cylinder 310 and the auxiliary hydraulic cylinder 326 are connected to the hydraulic station; the electric control valve, the electric heating component 202, the temperature control probe and the hydraulic station are all electrically connected to the controller.

[0027] The operation process of the Mini LED substrate vacuum pressing machine is as follows: a group of base plates and copper plates are placed on each heating plate 200, the door body 110 is closed and the pressing chamber 101 is evacuated by a vacuum pumping device, the controller controls the electric control valve to open, and the heat transfer oil enters the heat transfer oil pipeline 201 of the heating plate 200 to increase the temperature of the heating plate 200, and the controller controls the electric heating component 202 to start. Using the information fed back by multiple temperature control probes, the controller controls the heating power of the electric heating component 202 to accurately increase the temperature of the heating plate 200 to the set temperature and maintain it within the set temperature range (for example, within plus or minus 0.2°). During this process, the base plate and the copper plate are heated synchronously. Then the controller controls the hydraulic station to move. The main hydraulic cylinder 310 pushes the auxiliary pressure-maintaining mechanism 320 and the bottom heating plate 200 to rise, so that multiple heating plates 200 are stacked and clamp multiple groups of bottom plates and copper plates. At this time, the bottom plates and copper plates have been preliminarily clamped to prevent the bottom plates and copper plates from shifting. Then the auxiliary hydraulic cylinder 326 pushes the wedge block 323 to move, and uses the cooperation of the inclined surface to push the support plate 322 up to increase the pressing force and pressure. The controller accurately controls the output hydraulic oil pressure and accurately controls the pressing force. The hydraulic station is driven by a servo motor and can accurately control the output hydraulic oil pressure. The heating method of the combination of thermal oil and electric heating component 202, combined with the temperature control probe, can accurately control the temperature and stability of the heating plate. The auxiliary pressure-maintaining mechanism 320 is used to improve the pressing force and the stability of the pressing force, improve the performance of the substrate, and meet the production needs of MiniLED.

[0028] like Figure 4As shown, in some embodiments of the first aspect of the present invention, the heating plate 200 has two electric heating components 202, and the two electric heating components 202 are distributed on both sides of the thermal oil pipeline 201. This is mainly because after the thermal oil pipeline 201 is designed to be curved, there is still a lot of free space in the heating plate 200. The two electric heating components 202 are used to fill both sides of the thermal oil pipeline 201 to reduce the vacancy, which helps to improve the temperature uniformity and heating speed of the heating plate 200. The heating plate 200 can use electric heating wires, electric heating tubes, graphene heating elements, etc. Figure 3 As shown, for ease of processing, the heating plate 200 can be divided into two plates. After processing the receiving grooves of the thermal oil pipeline 201 and the electric heating component 202, the two plates are assembled into one, such as by welding or bolting.

[0029] Reference Figure 3 In some embodiments of the first aspect of the present invention, for the U-shaped curved channel of the thermal oil pipeline 201, the electric heating component 202 is also provided with a U-shaped curved portion, and the curved portion is located in the inner area of ​​the curved channel, further increasing the heating density and helping to improve the temperature uniformity and heating speed of the heating plate 200.

[0030] It can be understood that multiple pressure sensors are connected to the support plate 322, and the multiple pressure sensors are distributed at intervals along the circumference of the support plate 322. The multiple pressure sensors can be arranged in a circular ring, or in various shapes such as two circular rings, a rectangular ring, etc., and can be designed according to the shape and area size of the support plate 322.

[0031] Reference Figure 5 and Figure 6 In some embodiments of the first aspect of the present invention, the auxiliary pressure-maintaining mechanism 320 uses two wedge blocks 323, which are distributed on opposite sides of the slider 325. The corresponding slider 325 is provided with two symmetrical guide slopes 3251. The two wedge blocks 323 push the slider 325 to rise from both sides, and the force is relatively balanced and stable. In actual operation, the auxiliary hydraulic cylinder 326 pushes the wedge block 323 to move, and the slope of the wedge block 323 fits with the guide slope 3251, thereby pushing the slider 325 to rise. By controlling the output force of the auxiliary hydraulic cylinder 326, the rising distance of the slider 325 can be controlled, thereby adjusting the pressing force. The output force of the auxiliary hydraulic cylinder 326 is controlled by the hydraulic oil pressure output by the hydraulic station, so as to achieve the purpose of accurately controlling the pressing force and improving the stability of the pressing force. In addition, three wedge blocks 323 or more wedge blocks 323 may be used, or one wedge block 323 may be used, and the side of the slider 325 away from the guide slope 3251 is in sliding cooperation with the base 321, for example, connected by a linear module, connected by a slide rail, etc.

[0032] Reference Figure 5and Figure 6 In some embodiments of the first aspect of the present invention, a support groove 327 is further provided on the upper end surface of the base 321, and the support groove 327 is V-shaped. A support block 328 is provided on the bottom surface of the support plate 322, and the shape of the support block 328 matches the shape of the support groove 327. When the slider 325 is not pushed up by the wedge block 323, the support block 328 abuts against the inner wall of the support groove 327, so that the base 321 supports the slider 325 and the support plate 322, and when the auxiliary hydraulic cylinder 326 is in a retracted state, the wedge block 323 is disengaged from the slider 325, and the gravity of the slider 325 and the support plate 322 will not be transmitted to the auxiliary hydraulic cylinder 326, thereby avoiding crushing the auxiliary hydraulic cylinder 326.

[0033] like Figure 6 As shown, in some embodiments of the first aspect of the present invention, a support portion 329 is provided on the bottom surface of the support plate 322, and the support portion 329 includes a cylinder and a plurality of ribs uniformly distributed around the cylinder. Considering that the area of ​​the support plate 322 is large, the structural strength and rigidity of the support plate 322 can be greatly increased by providing a plurality of ribs, which is conducive to stably supporting the heating plate 200. The slider 325 and the support block 328 are an integrated structure and are fixed to the support portion 329, so as to improve the stable supporting force, push the heating plate 200 to rise and apply the pressing force.

[0034] Reference Figure 1 In some embodiments of the first aspect of the present invention, the outer wall of the housing 100 is connected with a locking mechanism 120. In view of the rectangular shape of the door body, two locking mechanisms 120 are usually arranged on both sides of the door body, and the two locking mechanisms 120 on the same side correspond to the upper and lower ends of the door body 110. The locking mechanism 120 includes a locking seat 121 and a wrench 122. The locking seat 121 is detachably connected to the housing 100. The locking seat 121 is provided with a rotating shaft 123. The end of the wrench 122 is provided with a cam 124. The cam 124 is rotatably connected to the rotating shaft 123. By rotating the wrench 122, the part with a larger radius of the cam 124 can be rotated to abut against the side of the door body 110 away from the housing 100, thereby pushing the door body 110 to press against the side of the housing 100, and the connection is tight, the sealing is improved, and it is helpful to evacuate the pressing chamber 101.

[0035] It is understandable that, in order to facilitate the movement of the door body 110, the locking mechanism 120 can be disassembled as a whole, and a positioning pin can be set on the outer wall of the housing 100, and the locking seat 121 is provided with a positioning hole that matches the positioning pin. After the door body 110 moves to the closed pressing cavity 101, the locking seat 121 is installed on the positioning pin, and then the wrench 122 is turned to lock. Since the force of the door body on the locking mechanism 120 is perpendicular to the positioning pin, the locking mechanism 120 can be fixed. Of course, a detachable structure such as a bolt or a buckle can also be set on the outer wall of the housing 100 to fix the locking mechanism 120. When moving the door body 110, the two locking mechanisms 120 on one side of the door body 110 can be removed, which is convenient for operation. In addition, the locking seat 121 can also be hinged to the outer wall of the housing 100. When the door body 110 moves, the locking seat 121 can be rotated to avoid the door body 110, which is convenient for operation.

[0036] like Figure 8 As shown, a labyrinth sealing structure is arranged between the housing 100 and the door body 110, and a sealing gasket 130 is fixed on the side of the housing 100. The two sides of the sealing gasket 130 are raised cylindrical ribs, and the door body 110 is provided with a plurality of sealing edges 111 arranged at intervals. The sealing edges 111 are inserted into the grooves of the sealing gasket 130, and the plurality of grooves are located between two cylindrical ribs, thereby forming a labyrinth seal. Under the push of the cam 124, the door body 110 and the sealing gasket 130 can be in close contact, and the sealing edges 111 extend into the grooves inserted in the sealing gasket 130 to improve the sealing performance, which is beneficial to the vacuuming of the pressing cavity 101, helps to improve the vacuum degree, reduces the influence of gas on pressing, and makes the bottom plate and the copper plate more tightly combined, which is beneficial to improving the performance of the produced Mini LED substrate.

[0037] The embodiment of the second aspect of the present invention provides a control method, which is applied to the MiniLED substrate vacuum pressing machine of the embodiment of the first aspect, and the control method includes the following steps: S100, after loading multiple sets of bottom plates and copper plates, move the closing door 110 to close the pressing chamber 101, obtain a high vacuum environment for the pressing chamber 101 through a vacuum pump, the controller controls the electric control valve to open, and the heat transfer oil enters the heat transfer oil pipeline 201 of the heating plate 200 to increase the temperature of the heating plate 200, and the controller controls the electric heating component 202 to start, and the temperature of the heating plate 200 is increased to a set temperature and maintained within a set temperature range (for example, plus or minus 0.2°); S200, the controller controls the hydraulic station to start, the hydraulic station outputs hydraulic oil, first drives the main hydraulic cylinder 310 to start, the main hydraulic cylinder 310 pushes the auxiliary pressure-maintaining mechanism 320 and the bottom heating plate 200 to move upward, so that multiple heating plates 200 are stacked and clamp multiple groups of bottom plates and copper plates. At this time, a small pressing force is applied to the multiple heating plates 200, and the inlet and outlet oil ports of the main hydraulic cylinder 310 can be closed to fix the position of the auxiliary pressure-maintaining mechanism 320; S300, the hydraulic station drives the auxiliary hydraulic cylinder 326 of the auxiliary pressure maintaining mechanism 320 to start, and the auxiliary hydraulic cylinder 326 pushes the wedge block 323 to move in the slide groove 324, thereby pushing the slider 325 and the support plate 322 to rise, increasing the pressing force, and stabilizing the pressing force within the set range. By controlling the output pressure of the hydraulic station, the output force of the auxiliary hydraulic cylinder 326 is stabilized within a certain range, thereby improving the stability of the pressing process.

[0038] In some embodiments of the second aspect of the present invention, in step S100, the thermal oil raises the temperature of the heating plate 200 to more than 95% of the set temperature, and then the electric heating component 202 is used to raise the temperature of the heating plate 200 to the set temperature.

[0039] Furthermore, in order to keep the temperature of the heating plate 200 within a set temperature range, the controller receives signals from multiple temperature control probes, and the controller accurately controls the temperature of the heating plate 200 through an integrated PID controller, so that the temperature of the heating plate 200 is kept within a set temperature range (for example, plus or minus 0.2°). The control equation used by the PID controller is: , where u(t) is the output of the controller, e(t) is the control error, i.e. the difference between the desired value and the actual value, , and are proportional coefficient, integral coefficient and differential coefficient respectively, which are determined according to the operating data of the system. In this equation, The proportional part responds immediately according to the current value of the deviation. The larger the deviation, the greater the output, which helps to quickly reduce the deviation. To integrate the deviation, the output is adjusted by accumulating the deviation, which helps to eliminate the steady-state error; Adjusting the output according to the rate of change of the deviation helps to reduce overshoot and speed up the system response. The algorithm of the PID controller is easy to implement and debug, has good stability and robustness, and has a certain adaptability to system parameter changes and measurement noise. The system has a fast response speed, high control accuracy, and more adjustable parameters, which can be adjusted according to actual needs.

[0040] In step S100, the heating stage is from the start of the electric heating component 202 to the temperature of the heating plate 200 reaching the set temperature range. In the heating stage, the power increase of the electric heating component 202 satisfies the equation: Y=K*arctanX, where Y is power, X is time (range 0 to 10, unit is second), K is the proportional coefficient, and K is determined according to different specifications of the bottom plate and copper plate. In the heating stage, the temperature of the heating plate 200 increases rapidly to close to the set temperature. After reaching the maximum time (10 seconds), it enters the insulation stage, and the temperature of the hot plate 200 is adjusted by the PID controller so that the temperature of the hot plate 200 is kept within the set temperature range.

[0041] In step S300, after the auxiliary hydraulic cylinder 326 is started, the value of the pressing force is detected by multiple pressure sensors on the support plate 322, and the pressing force is increased to exceed the set range, and then the pressing force is reduced to within the set range. The pressing force exceeds the upper limit of the set range by no more than 5%, and the time is 2 seconds. For example, if the setting range of the pressing force is 100-110kN, the pressing force is first increased to 113kN. After 2 seconds, the output force of the auxiliary hydraulic cylinder 326 decreases, and the pressing force drops to within the set range.

[0042] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. Mini LED substrate vacuum pressing machine, characterized in that: include: A casing, wherein a pressing cavity is formed inside the casing, a movable door body is provided on the front side of the casing to open or close the pressing cavity, and the pressing cavity is connected to a vacuum pumping device through a pipeline; A plurality of heating plates are arranged in the pressing cavity at intervals along the vertical direction, the heating plates are slidably connected to the housing, a heat transfer oil pipeline and an electric heating component are arranged inside the heating plates, the heat transfer oil pipeline forms at least two U-shaped curved channels, the electric heating component fills the area outside the heat transfer oil pipeline, an electric control valve is arranged at the inlet of the heat transfer oil pipeline, the heating plates are connected to a plurality of temperature control probes, and the plurality of temperature control probes are distributed at intervals along the circumference of the heating plates; A pressing support assembly is arranged on the bottom surface of the pressing cavity, the pressing support assembly comprises a main hydraulic cylinder and an auxiliary pressure-maintaining mechanism, the main hydraulic cylinder is arranged vertically, the auxiliary pressure-maintaining mechanism comprises a base, a support plate and a wedge block, the base is fixed to the output end of the main hydraulic cylinder, the upper end surface of the base is provided with a slide groove, the bottom surface of the support plate is provided with a slider, the slider and the wedge block can both slide in the slide groove, the end of the slider is provided with a guide inclined surface, the inclined surface of the wedge block can fit the guide inclined surface, the wedge block is connected with an auxiliary hydraulic cylinder, the auxiliary hydraulic cylinder is fixed to the base, the lowest heating plate is fixed to the top surface of the support plate, the main hydraulic cylinder and the auxiliary hydraulic cylinder are connected to the hydraulic station; A controller, wherein the electric control valve, the electric heating component, the temperature control probe and the hydraulic station are all electrically connected to the controller.

2. The Mini LED substrate vacuum pressing machine according to claim 1, characterized in that: The heating plate has two electric heating components, and the two electric heating components are distributed on both sides of the thermal oil pipeline.

3. The Mini LED substrate vacuum pressing machine according to claim 2, characterized in that: The electric heating component is provided with a U-shaped curved portion, and the curved portion is located in an inner area of ​​the curved channel.

4. The Mini LED substrate vacuum pressing machine according to claim 1, characterized in that: The support plate is connected to a plurality of pressure sensors, and the plurality of pressure sensors are distributed at intervals along the circumference of the support plate.

5. The Mini LED substrate vacuum pressing machine according to claim 1, characterized in that: The auxiliary pressure-maintaining mechanism has two wedge blocks, which are distributed on both sides of the sliding block, and the sliding block is provided with two symmetrical guiding inclined surfaces.

6. The Mini LED substrate vacuum pressing machine according to claim 5, characterized in that: The upper end surface of the base is provided with a support groove, and the support groove is V-shaped. The bottom surface of the support plate is provided with a support block, the shape of the support block matches the shape of the support groove, and the support block abuts against the inner wall of the support groove.

7. The Mini LED substrate vacuum pressing machine according to claim 5, characterized in that: The bottom surface of the support plate is provided with a support portion, the support portion comprises a cylinder and a plurality of ribs uniformly distributed circumferentially around the cylinder, the sliding block and the support block are an integral structure and are fixed to the support portion.

8. The Mini LED substrate vacuum pressing machine according to claim 1, characterized in that: The outer wall of the casing is connected to a locking mechanism, which includes a locking seat and a wrench. The locking seat is detachably connected to the casing, the locking seat is provided with a rotating shaft, and a cam is provided at the end of the wrench. The cam is rotatably connected to the rotating shaft, and the cam can abut the side of the door body away from the casing.

9. A control method, applied to a Mini LED substrate vacuum pressing machine as claimed in any one of claims 1 to 8, characterized in that: The control method comprises the following steps: S100, after the base plate and the copper plate are loaded, the controller controls the electric control valve to open, and the heat transfer oil enters the heat transfer oil pipeline of the heating plate to increase the temperature of the heating plate, and the controller controls the electric heating component to start, and the temperature of the heating plate is increased to a set temperature and maintained within a set temperature range; S200, the controller controls the hydraulic station to start, the hydraulic station drives the main hydraulic cylinder to start, and the main hydraulic cylinder pushes the auxiliary pressure-maintaining mechanism and the bottom heating plate to move upward, so that multiple heating plates are stacked and clamp multiple groups of bottom plates and copper plates; S300, the hydraulic station drives the auxiliary hydraulic cylinder of the auxiliary pressure-maintaining mechanism to start, and the auxiliary hydraulic cylinder pushes the wedge block to move in the slide groove, thereby pushing the slider and the support plate to rise, increasing the pressing force, and stabilizing the pressing force within a set range.

10. The control method according to claim 9, characterized in that: In the step S100, the heat transfer oil raises the temperature of the heating plate to more than 95% of the set temperature, the electric heating component raises the temperature of the heating plate to the set temperature, the controller receives signals from the multiple temperature control probes, and the controller accurately controls the temperature of the heating plate through an integrated PID controller.

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