Batch dust-free sealing device for power semiconductor devices and use method of batch dust-free sealing device

Abstract

The invention relates to the technical field of semiconductor packaging, in particular to a batch dust-free packaging device for power semiconductor devices and a using method of the batch dust-free packaging device for the power semiconductor devices, and the batch dust-free packaging device comprises a plastic packaging machine main body, a plastic packaging mold and a side frame, an upper plastic packaging mold and a lower plastic packaging mold are installed at the upper end and the lower end of the plastic packaging machine body respectively, a side frame is fixedly connected to one side of the plastic packaging machine body, a cleaning roller storage box is installed on one side of the side frame, and an electric push rod and an air supply and negative pressure unit are arranged in the cleaning roller storage box. Three-step dust-free cleaning of blowing, sucking and shaking is automatically carried out on a mold cavity after each time of plastic packaging; during air blowing, air is expanded and cooled twice through a conical barrel, the mold is synchronously cooled, and stubborn particles are stripped; negative pressure is formed on the surface of the cotton layer during air suction, and all residual scraps are sucked away; after cleaning is finished, the roller body returns to the storage box, the blocking block collides with the toothed plate to enable the roller body to jolt at high frequency, and attachments are shaken off into the box and are sealed and collected.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging technology, specifically to a batch cleanroom packaging apparatus for power semiconductor devices and its usage method. Background Technology

[0002] The core of the mass production cleanroom packaging equipment for power semiconductor devices is a high-cleanliness transfer molding system: the barrel heats and melts epoxy resin particles, and the vacuum-assisted screw injects the melt into a multi-cavity mold through a 1 µm filter channel at a stable voltage of ±0.1 MPa. The mold cavity wall is coated with diamond and circulated with 25 ℃ constant temperature water, and the cooling and curing takes only 30 s. The FFU (Fan Filter Unit) above the molding area provides Class 100 laminar flow, with simultaneous static electricity removal via ion air knife, ensuring residual oxygen levels of <500 ppm throughout the process to prevent copper frame oxidation. Online CCD and infrared detection detects voids and warpage, and defective products are removed in real time by a six-axis robotic arm. A single machine can encapsulate 20,000 TO-247 or SiC modules per day with a yield rate >99.5%. During the molding process using molding molds, the mold needs to be cleaned before each filling to avoid particulate impurities inside the mold cavity affecting the quality of the molded semiconductor devices. Some molding mold cavities are cleaned by blowing with compressed air, but there is a problem that stubborn stains attached to the inside of the mold cavity cannot be removed. Therefore, to address the above problems, a batch cleanroom packaging device for power semiconductor devices and its usage method are proposed. Summary of the Invention

[0003] The purpose of this invention is to provide a batch cleanroom packaging device for power semiconductor devices and its usage method, in order to solve the problem that during the molding process using a molding die, the die needs to be cleaned before each filling to avoid particulate impurities inside the die cavity affecting the quality of the packaged semiconductor device. In some cases, the molding die cavity is cleaned by blowing with compressed air, but there is a problem that stubborn stains attached to the inside of the die cavity cannot be cleaned.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A batch cleanroom packaging device for power semiconductor devices and its usage method are disclosed. The device includes a molding machine body, a molding die for molding power semiconductor devices, and a side frame. An upper molding die and a lower molding die are respectively installed at the upper and lower ends of the molding machine body. A side frame is fixedly connected to one side of the molding machine body, and a cleaning roller storage box is installed on one side of the side frame. The cleaning roller storage box contains an electric push rod and an air supply and negative pressure unit. A cleaning roller is installed at the top of the electric push rod. The cleaning roller includes a cleaning cotton layer, inside which is an internal cylindrical shell. The internal cylindrical shell is divided into two sections, which are fixedly connected by an extension tube. Multiple conical cylinders are fixedly connected in a ring at equal intervals inside the internal cylindrical shell. A connecting shaft is fixedly connected to the end of the internal cylindrical shell away from the extension tube. A barrier block is fixedly connected to the outside of the connecting shaft, and a round shaft is fixedly connected to the other end of the connecting shaft. A barrier toothed plate is provided below the barrier block.

[0005] As a further optimization of the present invention, the cleaning roller storage box includes a box body with openings at both ends. Multiple staggered sealing strips are installed at the end of the box body away from the side frame. The upper end of the sealing strips is fixedly connected to the upper end of the box body opening. The sealing strips are made of plastic. The barrier toothed plate is fixedly connected to the lower end of the box body.

[0006] As a further optimization of the present invention, the electric push rod includes a push rod body, the fixed end of the push rod body passes through the side frame and is fixedly connected to the side frame, the moving end of the push rod body has a circular hole, a plurality of connecting blocks are fixedly connected to one side of the circular hole and are distributed in an annular pattern, and a fixing ring plate is fixedly connected to the other end of the connecting block.

[0007] As a further optimization of the present invention, the fixed ring plate is rotatably connected to the round shaft through a spring, the electric push rods are distributed parallel to both sides of the cleaning roller, and the connecting shaft is rotatably connected to the round hole opened at the moving end of the push rod body through a round hole.

[0008] As a further optimization of the present invention, the connecting shaft includes a shaft body, and a buffer assembly is fixedly connected to the outside of the shaft body. The buffer assembly includes a rubber sleeve, and the rubber sleeve has reset holes arranged in an annular pattern at equal intervals inside.

[0009] As a further optimization of the present invention, the outer layer of the rubber sleeve is a hard and smooth plastic layer, the inside of the rubber sleeve is fixedly connected to the shaft, the reset hole is a cylindrical hole with a circular cross-section, and the opening edges at both ends of the reset hole are provided with arc-shaped chamfers.

[0010] As a further optimization of the present invention, the main body of the sealing machine is provided with a column for positioning the sealing mold to move up and down. There are four columns, which are parallel to each other, and the upper and lower ends of the columns are fixedly connected to the main body of the sealing machine by screws and flanges.

[0011] As a further optimization of the present invention, the air supply and negative pressure unit includes an air pipe, one end of which is connected to a bidirectional air pump through a drying and dust collection unit. The bidirectional air pump is a medium-pressure vortex bidirectional pump, and the bidirectional air pump is fixedly connected to the side frame by screws.

[0012] As a further optimization of the present invention, the air tube is wrapped around the outside of the extension tube, the end of the air tube away from the bidirectional air pump passes through the middle of the extension tube, and the end of the air tube passing through the extension tube is connected to the inside of the extension tube.

[0013] As a further optimization of the present invention, it includes the following steps: Step 1: Connect an external industrial power supply to power the equipment. After powering on, place the lead frame of the power semiconductor device that needs to be encapsulated, which has already been chip mounted and wire bonded, into a 175°C encapsulation mold. High-pressure injection of preheated epoxy paste into the cavity will embed the chip and pre-cur it within 10 seconds. After demolding, remove the flash and then cure at 180°C for 2–4 hours to complete cross-linking and form a hard and moisture-proof shell. Step 2: After molding is complete, the molding mold and ejector pins instantly lift the frame. The vacuum suction cup grabs and moves it to the cooling tray to cool down. After visual inspection and waste removal, the whole process is controlled within two seconds and kept at a low temperature to ensure that the package can be safely demolded without warping or scratches. Step 3: After the material is unloaded, control the electric push rod to push the cleaning roller across the surface of the molding die to clean the surface of the molding die; During the extension of the electric push rod, the bidirectional air pump blows gas into the air pipe. The gas passes through the air pipe into the extension pipe, and then is blown from the conical cylinder to the cleaning cotton layer. The gas expands twice and does work on the outside, reducing the internal energy of the gas and lowering the temperature of the gas blown to the cleaning cotton layer. During the retraction of the electric push rod, the bidirectional air pump draws air from the air pipe, and the surface of the cleaning cotton layer is under negative pressure at this time. Step 4: Finally, the cleaning roller enters the housing as a whole. During the initial entry, the barrier block and the barrier tooth plate come into contact, keeping the buffer assembly in a "deformation-reset" state, causing the cleaning roller to bounce. During this process, the bidirectional air pump exits the shutdown state.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, by setting a rotatable cleaning roller that can switch between blowing and suction, the mold cavity is automatically cleaned in three steps of "blowing-suction-shaking" after each molding process: during blowing, the gas expands and cools twice through the conical cylinder, simultaneously cooling the mold and peeling off stubborn particles; during suction, a negative pressure is formed on the surface of the cotton layer to suck away all residual debris; after cleaning, the roller is returned to the storage box, and the collision between the barrier block and the toothed plate causes the roller to vibrate at high frequency, shaking off the attached material into the box and sealing it for collection. The entire process requires no manual intervention, and a single cleaning takes less than 2 seconds. It can remove ≥99% of μm-level particles, and the residual dust on the mold surface is ≤0.1 mg / cavity, significantly reducing the molding defect rate and realizing batch, high-efficiency, low-temperature, and dust-free packaging of power semiconductor devices. 2. In this invention, the electric push rod, bidirectional air pump, drying and dust collection unit, and spring are all modularly integrated into the side frame and storage box, resulting in a compact structure that does not occupy additional production line space. The electric push rod and the cleaning roller are connected by a flexible connection with a buffer component, which can automatically compensate for thermal deformation and positioning errors, ensuring that the high-speed reciprocating and rotary composite motion is free from jamming, and can run continuously for more than 500,000 times without maintenance. The MTBF is 3 times higher than that of traditional air-blowing cleaning.

[0015] 3. In this invention, the gas expands twice during the blowing stage, reducing the temperature by 8–12 ℃, which prevents the mold from overheating and avoids epoxy residue from curing and sticking to the mold again; during the suction stage, negative pressure recovery sends more than 95% of the dust back to the drying and dust collection unit for circulation filtration, and the sealing strip inside the box prevents microparticles from escaping, achieving a local dust-free environment; the bidirectional air pump has an average power consumption of <120 W, which is approximately 70% more energy-efficient than continuous compressed air cleaning, and a single unit can save more than 15,000 kWh of electricity per year, significantly reducing the cost of mass production packaging. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the installation location of the gas supply and negative pressure unit of the present invention; Figure 3 For the present invention Figure 2 Schematic diagram of the structure at point A in the middle; Figure 4 For the present invention Figure 2 Schematic diagram of the structure at point B; Figure 5 This is a schematic diagram of the electric actuator structure of the present invention; Figure 6 This is a schematic diagram of the cleaning roller structure of the present invention; Figure 7 For the present invention Figure 6 Schematic diagram of the structure at point C; Figure 8 This is a schematic diagram of the cleaning roller storage box structure of the present invention; Figure 9This is a schematic diagram of the buffer component structure of the present invention.

[0017] In the diagram: 1. Main body of the laminator; 2. Laminator mold; 3. Side frame; 4. Cleaning roller storage box; 41. Box body; 42. Sealing strip; 5. Electric push rod; 51. Push rod body; 52. Round hole; 53. Connecting block; 54. Fixing ring plate; 6. Cleaning roller; 61. Cleaning cotton layer; 62. Internal cylindrical shell; 63. Conical cylinder; 64. Extension tube; 65. Connecting shaft; 651. Shaft body; 652. Buffer assembly; 6521. Rubber sleeve; 6522. Reset hole; 66. Round shaft; 67. Barrier block; 68. Barrier toothed plate; 7. Columns; 8. Air supply and negative pressure unit; 81. Air pipe; 82. Drying and dust collection unit; 83. Two-way air pump; 9. Clockwork spring. Detailed Implementation

[0018] Please see Figures 1-9 The present invention provides a technical solution: A mass cleanroom packaging device for power semiconductor devices and its usage method include a molding machine body 1, a molding mold 2 for molding and packaging power semiconductor devices, and a side frame 3. The upper mold and the lower mold of the molding mold 2 are respectively installed at the upper and lower ends of the molding machine body 1. The side frame 3 is fixedly connected to one side of the molding machine body 1. A cleaning roller storage box 4 is installed on one side of the side frame 3. The cleaning roller storage box 4 is equipped with an electric push rod 5 and an air supply and negative pressure unit 8. A cleaning roller 6 is installed at the top of the electric push rod 5. The cleaning roller 6 includes a cleaning cotton layer 61, inside which an inner cylindrical shell 62 is installed. The inner cylindrical shell 62 is set in two sections and is fixedly connected by an extension tube 64. Inside the inner cylindrical shell 62, a plurality of conical cylinders 63 are fixedly connected in an annular shape at equal intervals. A connecting shaft 65 is fixedly connected to one end of the inner cylindrical shell 62 away from the extension tube 64. A blocking block 67 is fixedly connected to the outside of the connecting shaft 65. A round shaft 66 is fixedly connected to the other end of the connecting shaft 65. A blocking toothed plate 68 is provided below the blocking block 67.

[0019] Specifically, such as Figure 1 and Figure 8As shown, specifically: the cleaning roller storage box 4 includes a box body 41, which is open at both ends. Multiple staggered sealing strips 42 are installed at the end of the box body 41 away from the side frame 3. The upper end of the sealing strip 42 is fixedly connected to the upper end of the opening of the box body 41. The sealing strip 42 is made of plastic. The barrier tooth plate 68 is fixedly connected to the lower end of the inside of the box body 41. With the above settings, when the cleaning roller 6 enters the inside of the box body 41, it will be bumped, shaking off the dust particles on the surface of the cleaning roller 6. The sealing strips 42 prevent the shaken dust from escaping from the inside of the box body 41. Specifically, such as Figure 1-3 , Figure 5 As shown, specifically: the electric push rod 5 includes a push rod body 51, the fixed end of the push rod body 51 passes through the side frame 3, and the fixed end of the push rod body 51 is fixedly connected to the side frame 3. The moving end of the push rod body 51 has a circular hole 52. A plurality of connecting blocks 53 are fixedly connected to one side of the circular hole 52 and are distributed in annularly. The other end of the connecting block 53 is fixedly connected to a fixed ring plate 54. Through the above settings, the cleaning roller 6 can be stably limited and the cleaning roller 65 can be stably pushed to reciprocate, so as to achieve the cleaning work on the surface of the plastic sealing mold 2. The fixed ring plate 54 is rotatably connected to the circular shaft 66 through the spring spring 9. The electric push rods 5 are distributed parallel to both sides of the cleaning roller 6. The connecting shaft 65 is rotatably connected to the circular hole 52 opened at the moving end of the push rod body 51 through the circular hole 52. Through the above settings, the cleaning roller 6 can be rotated during the process of being pushed by the electric push rod 51, further improving the cleanliness of the surface of the plastic sealing mold 2. Specifically, such as Figure 1-4 , Figure 6 , Figure 7 as well as Figure 9 As shown, specifically: the connecting shaft 65 includes a shaft body 651, and a buffer assembly 652 is fixedly connected to the outside of the shaft body 651. The buffer assembly 652 includes a rubber sleeve 6521, and the rubber sleeve 6521 has a ring-shaped, equidistant reset hole 6522 inside. Through the above settings, the stability of the connection between the electric push rod 5 and the cleaning roller 6 is further improved, so as to ensure the stability of the overall operation of the device. The outer layer of the rubber sleeve 6521 is a hard and smooth plastic layer. The rubber sleeve 6521 is fixedly connected to the shaft body 651. The reset hole 6522 is a cylindrical hole with a circular cross-section. The opening edges at both ends of the reset hole 6522 are provided with arc-shaped chamfers. Through the above settings, during the contact between the blocking block 67 and the blocking tooth plate 68, the cleaning roller 6 can be bumped by the deformation of the rubber sleeve 6521, and can be quickly reset. The arc-shaped chamfers can extend the service life of the rubber sleeve 6521 in actual use. Specifically, such as Figure 1As shown, specifically: the body 1 of the sealing machine is equipped with four columns 7 for positioning the sealing mold 2 to move up and down. The four columns 7 are parallel to each other, and the upper and lower ends of the columns 7 are fixedly connected to the body 1 of the sealing machine by screws and flanges. Through the above settings, the sealing mold 2 can be stably limited, further improving the stability of the sealing process and the stability of the sealing mold 2 during up and down movement. Specifically, such as Figure 1 and Figure 2 As shown, specifically: the air supply and negative pressure unit 8 includes an air pipe 81. One end of the air pipe 81 is connected to the bidirectional air pump 83 through the drying and dust collection unit 82. The bidirectional air pump 83 is a medium-pressure vortex bidirectional pump. The bidirectional air pump 83 is fixedly connected to the side frame 3 by screws. The air pipe 81 is wrapped around the outside of the extension tube 64. The end of the air pipe 81 away from the bidirectional air pump 83 passes through the middle of the extension tube 64, and the end of the air pipe 81 passing through the extension tube 64 is connected to the inside of the extension tube 64. With the above settings, gas blowing and negative pressure generation can be performed as needed. With the cleaning roller 6, the cleanliness of the cleaning is further improved.

[0020] Includes the following steps: Step 1: Connect an external industrial power supply to power the equipment. After powering on, place the lead frame of the power semiconductor device that needs to be encapsulated, which has already been chip mounted and wire bonded, into the 175 ℃ encapsulation mold 2. High-pressure injection of preheated epoxy cake into the cavity will embed the chip and pre-cur it within 10 seconds. After demolding, remove the flash and then cure at 180 ℃ for 2–4 hours to complete cross-linking and form a hard and moisture-proof shell. Step 2: After molding is completed, the molding mold 2 and the ejector pins instantly lift the frame. The vacuum suction cup grabs and moves it to the cooling tray to cool down. After visual inspection and waste removal, the whole process is controlled within two seconds and kept at a low temperature to ensure that the package can be safely demolded without warping or scratches. Step 3: After the material is unloaded, control the electric push rod 5 to push the cleaning roller 6 across the surface of the molding die to clean the surface of the molding die 2; During the extension of the electric push rod 5, the bidirectional air pump 83 blows gas into the air pipe 81. The gas enters the extension pipe 64 through the air pipe 81, and then blows from the conical cylinder 63 to the cleaning cotton layer 61. The gas that enters expands twice and does work on the outside. The internal energy of the gas decreases, which lowers the temperature of the gas blown to the cleaning cotton layer 61. During this process, the cleaning cotton layer 61 cleans and cools the surface of the plastic sealing mold 2, while blowing away any remaining particles and debris from the plastic sealing mold 2. During the retraction of the electric push rod 5, the bidirectional air pump 83 draws gas from the air pipe 81, and at this time the surface of the cleaning cotton layer 61 is under negative pressure. During this process, the cleaning cotton layer 61 absorbs the particles and debris that were not completely cleaned from the surface of the plastic sealing mold 2; Step 4: Finally, the cleaning roller 6 enters the housing 41 as a whole. During the initial entry, the blocking block 67 and the blocking toothed plate 68 come into contact, keeping the buffer assembly 652 in a "deformation-reset" state, causing the cleaning roller 6 to bounce. During this process, the bidirectional air pump 83 is shut down.

[0021] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A batch cleanroom packaging apparatus for power semiconductor devices, comprising a molding machine body (1), a molding die (2) for molding power semiconductor devices, and a side frame (3), characterized in that: The upper and lower ends of the sealing machine body (1) are respectively equipped with the upper mold of the sealing mold (2) and the lower mold of the sealing mold (2). A side frame (3) is fixedly connected to one side of the sealing machine body (1). A cleaning roller storage box (4) is installed on one side of the side frame (3). The cleaning roller storage box (4) is equipped with an electric push rod (5) and an air supply and negative pressure unit (8). A cleaning roller (6) is installed at the top of the electric push rod (5). The cleaning roller (6) includes a cleaning cotton layer (61), and an inner cylindrical shell (62) is installed inside the cleaning cotton layer (61). The inner cylindrical shell (62) is set in two sections, and the two sections of the inner cylindrical shell (62) are fixedly connected by an extension tube (64). A plurality of conical cylinders (63) are fixedly connected in a ring at equal intervals inside the inner cylindrical shell (62). A connecting shaft (65) is fixedly connected to one end of the inner cylindrical shell (62) away from the extension tube (64). A blocking block (67) is fixedly connected to the outside of the connecting shaft (65). A round shaft (66) is fixedly connected to the other end of the connecting shaft (65). A blocking toothed plate (68) is provided below the blocking block (67).

2. The mass production cleanroom packaging apparatus for power semiconductor devices according to claim 1, characterized in that: The cleaning roller storage box (4) includes a box body (41), which is open at both ends. Multiple sealing strips (42) are installed at the end of the box body (41) away from the side frame (3). The upper end of the sealing strip (42) is fixedly connected to the upper end of the opening of the box body (41). The sealing strip (42) is made of plastic. The barrier tooth plate (68) is fixedly connected to the lower end of the box body (41).

3. The batch cleanroom packaging apparatus for power semiconductor devices according to claim 1, characterized in that: The electric push rod (5) includes a push rod body (51), the fixed end of the push rod body (51) passes through the side frame (3), and the fixed end of the push rod body (51) is fixedly connected to the side frame (3). The moving end of the push rod body (51) is provided with a circular hole (52), and a plurality of connecting blocks (53) are fixedly connected to one side of the circular hole (52) at equal intervals in an annular pattern. The other end of the connecting block (53) is fixedly connected to a fixing ring plate (54).

4. The batch cleanroom packaging apparatus for power semiconductor devices according to claim 3, characterized in that: The fixed ring plate (54) is rotatably connected to the round shaft (66) through the spring spring (9). The electric push rod (5) is distributed parallel to both sides of the cleaning roller (6). The connecting shaft (65) is rotatably connected to the round hole (52) opened at the moving end of the push rod body (51) through the round hole (52).

5. The mass production cleanroom packaging apparatus for power semiconductor devices according to claim 1, characterized in that: The connecting shaft (65) includes a shaft body (651), and a buffer assembly (652) is fixedly connected to the outside of the shaft body (651). The buffer assembly (652) includes a rubber sleeve (6521), and the rubber sleeve (6521) has a resetting hole (6522) arranged in an annular shape at equal intervals inside.

6. The batch cleanroom packaging apparatus for power semiconductor devices according to claim 5, characterized in that: The outer layer of the rubber sleeve (6521) is a hard and smooth plastic layer. The rubber sleeve (6521) is fixedly connected to the shaft (651). The reset hole (6522) is a cylindrical hole with a circular cross-section. The opening edges at both ends of the reset hole (6522) are provided with arc-shaped chamfers.

7. The batch cleanroom packaging apparatus for power semiconductor devices according to claim 1, characterized in that: The body (1) of the sealing machine is equipped with a column (7) for positioning the sealing mold (2) to move up and down. There are four columns (7), which are parallel to each other. The upper and lower ends of the columns (7) are fixedly connected to the body (1) of the sealing machine by screws and flanges.

8. The batch cleanroom packaging apparatus for power semiconductor devices according to claim 1, characterized in that: The air supply and negative pressure unit (8) includes an air pipe (81). One end of the air pipe (81) is connected to a bidirectional air pump (83) through a drying and dust collection unit (82). The bidirectional air pump (83) is a medium-pressure vortex bidirectional pump. The bidirectional air pump (83) is fixedly connected to the side frame (3) by screws.

9. A batch cleanroom packaging apparatus for power semiconductor devices according to claim 8, characterized in that: The air tube (81) is wrapped around the outside of the extension tube (64). The end of the air tube (81) away from the bidirectional air pump (83) passes through the middle of the extension tube (64), and the end of the air tube (81) passing through the extension tube (64) is connected to the inside of the extension tube (64).

10. A method of using a batch cleanroom packaging apparatus for power semiconductor devices according to any one of claims 1-9, characterized in that: Includes the following steps: Step 1: Connect an external industrial power supply to power the equipment. After powering on, place the lead frame of the power semiconductor device that needs to be encapsulated, which has completed chip mounting and wire bonding, into a 175°C encapsulation mold (2). High-pressure injection of preheated epoxy cake into the cavity will embed the chip and pre-cur it within 10 seconds. After demolding, remove the flash and then cure at 180°C for 2–4 hours to complete cross-linking and form a hard and moisture-proof shell. Step 2: After the molding is completed, the molding mold (2) is used to lift the frame instantly. The vacuum suction cup grabs and moves it to the cooling tray to cool down. After visual inspection and cleaning, the whole process is controlled within two seconds and kept at a low temperature to ensure that the packaged body can be safely demolded without warping or scratches. Step 3: After the material is unloaded, control the electric push rod (5) to push the cleaning roller (6) across the surface of the molding die to clean the surface of the molding die (2); During the extension of the electric push rod (5), the bidirectional air pump (83) blows gas into the air pipe (81). The gas passes through the air pipe (81) and enters the extension pipe (64). Then it is blown from the conical cylinder (63) to the cleaning cotton layer (61). The gas expands twice and does work on the outside. The internal energy of the gas decreases, which lowers the temperature of the gas blown to the cleaning cotton layer (61). During the retraction of the electric push rod (5), the bidirectional air pump (83) draws gas from the air pipe (81), and the surface of the cleaning cotton layer (61) is under negative pressure at this time. Step 4: Finally, the cleaning roller (6) enters the housing (41) as a whole. During the distance after entering, the blocking block (67) and the blocking tooth plate (68) come into contact, so that the buffer assembly (652) is kept in the "deformation-reset" state, causing the cleaning roller (6) to bounce. During this process, the bidirectional air pump (83) is out of the shutdown state.

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