阅读说明：本技术 一种pcb板自动化曝光设备及方法 (Automatic exposure equipment and method for PCB (printed circuit board) ) 是由 王�华 陈志特 黄海浩 于 2021-11-01 设计创作，主要内容包括：本发明涉及一种PCB板自动化曝光设备及方法,其中一种PCB板自动化曝光设备及方法,包括机架、曝光架、往复直线运动装置、CCD相机、紫外线灯、上料机构和控制箱,所述机架的两侧内壁均设有滑轨,所述曝光架滑动连接在滑轨内,往复直线运动装置安装在机架上用于驱动曝光架沿着滑轨往复运动,CCD相机安装在机架上,所述CCD相机正对曝光架设置所述机架内设有曝光室,所述紫外线灯安装在曝光室内,上料机构设置在机架的一侧,所述上料机构包括料架和安装在料架底部的调节对位装置以及安装在料架上的机械手,该PCB板自动化曝光设备,使刮板自动化对菲林片与PCB基板刮平,避免菲林片与PCB基板之间存在气泡,与人工上料和刮平处理,曝光效率更高。(The invention relates to an automatic exposure device and a method for a PCB (printed circuit board), wherein the automatic exposure device and the method for the PCB comprise a rack, an exposure frame, a reciprocating linear motion device, a CCD (charge coupled device) camera, an ultraviolet lamp, a feeding mechanism and a control box, slide rails are arranged on the inner walls of two sides of the rack, the exposure frame is slidably connected in the slide rails, the reciprocating linear motion device is arranged on the rack and is used for driving the exposure frame to reciprocate along the slide rails, the CCD camera is arranged on the rack, the CCD camera is arranged in the rack opposite to the exposure frame, an exposure chamber is arranged in the exposure chamber, the feeding mechanism is arranged on one side of the rack, the feeding mechanism comprises a material rack, an adjusting and aligning device arranged at the bottom of the material rack and a manipulator arranged on the material rack, the automatic exposure device for the PCB enables a scraper to automatically scrape a film sheet and a PCB substrate, avoid having the bubble between film and the PCB base plate, with artifical material loading and strickle processing, exposure efficiency is higher.)

1. An automatic exposure equipment of PCB board characterized in that includes:

a frame (1);

the exposure frame (2), the inner walls of the two sides of the frame (1) are provided with slide rails (11), and the exposure frame (2) is connected in the slide rails (11) in a sliding manner;

the reciprocating linear motion device (3) is arranged on the rack (1) and is used for driving the exposure frame (2) to reciprocate along the slide rail (11);

the CCD camera (4) is arranged on the machine frame (1), and the CCD camera (4) is arranged right opposite to the exposure frame (2);

the ultraviolet lamp (5), the said framework (1) is equipped with the exposure room (12), the said ultraviolet lamp (5) is installed in exposure room (12);

the feeding mechanism (6) is arranged on one side of the rack (1), and the feeding mechanism (6) comprises a material rack (61), an adjusting and aligning device (62) arranged at the bottom of the material rack (61) and a manipulator (63) arranged on the material rack (61);

control box (7), install at frame (1) top, internally mounted circuit board (71) of control box (7), CCD camera (4) electric connection circuit board (71), install controller (72) on circuit board (71).

2. The automatic exposure equipment for the PCB according to claim 1, wherein the exposure frame (2) comprises a lower frame (21) slidably connected in a sliding rail (11), an acrylic plate (22) is installed at the center of the top of the lower frame (21), four corners of the bottom of the lower frame (21) are respectively provided with a lifting cylinder (23), an output shaft of the lifting cylinder (23) is fixedly connected with an upper frame (24) matched with the lower frame (21), a vacuum chamber is formed after the upper frame (24) and the lower frame (21) are matched, the acrylic plate (22) is located in the vacuum chamber, a vacuum pump (25) for vacuumizing the vacuum chamber is installed in the lower frame (21), a Mylar film (26) is installed in the upper frame (24), and a bidirectional film scraping device (27) for scraping the Mylar film (26) is installed at the top of the upper frame (24), the bidirectional film scraping device (27) comprises a mounting plate (271) fixed on an upper frame (24), film scraping cylinders (272) are symmetrically mounted at two ends of the mounting plate (271), a mounting seat (273) is fixed on an output shaft of each film scraping cylinder (272), a rotating shaft (274) is rotatably connected between the two mounting seats (273), a stepping motor (275) is fixed on one side of one mounting seat (273), an output shaft of the stepping motor (275) is fixedly connected with one end of the rotating shaft (274), a scraping plate (276) is rotatably connected to the outer side of the rotating shaft (274), a bidirectional torsion spring (277) is sleeved on the outer side of the rotating shaft (274), two ends of the bidirectional torsion spring (277) are respectively clamped with the scraping plate (276) and the rotating shaft (274), a baffle plate (2761) is fixed at one end of the scraping plate (276), and an arc-shaped plate (2741) is fixed on the outer side of the rotating shaft (274), and arc (2741) and baffle (2761) cooperate, arc (2741) include first contact surface (27411) and second contact surface (27412), contact switch (277) are all installed to the top both ends of going up frame (24), contact switch (277), step motor (275) and knifing cylinder (272) all with controller (72) electric connection.

3. The automatic exposure equipment of PCB board as stated in claim 1, wherein the adjusting and aligning device (62) includes an X-axis linear motor (621), a Y-axis linear motor (622) is fixed at the output end of the X-axis linear motor (621), a rotating motor (623) is fixed on an output shaft of the Y-axis linear motor (622), the X-axis linear motor (621), the Y-axis linear motor (622) and the rotating motor (623) are electrically connected with the circuit board (71), four corners of the material rack (61) are provided with coamings (611) with L-shaped sections, and a PCB placing groove (A) is formed among the four enclosing plates (611), a bearing disc (612) is connected in the PCB placing groove (A) in a sliding way, the bottom of the bearing plate (612) is provided with a bearing spring (613), and the bottom end of the bearing spring (613) is fixedly connected with the bottom of the material rack (61).

4. The automatic exposure equipment for the PCB board as claimed in claim 1, wherein the manipulator (63) comprises an L-shaped mounting frame (631) fixed at one side of the material frame (61), a feeding cylinder (632) is fixed at one end of the L-shaped mounting frame (631), a connecting plate (633) is fixed at an output shaft of the feeding cylinder (632), a taking and placing cylinder (634) is fixed at the top of the connecting plate (633), a bottom plate (635) is fixed at an output shaft of the taking and placing cylinder (634), and electric vacuum chucks (636) are uniformly installed at the bottom of the bottom plate (635).

5. The automatic exposure equipment for PCB boards as claimed in claim 2, wherein the reciprocating linear motion device (3) comprises a rack (31) fixed on the inner wall of the frame (1), a motor (32) is fixed at the bottom of the lower frame (21), a gear (33) is fixed at the output shaft of the motor (32), and the gear (33) is engaged with the rack (31).

6. The automatic exposure equipment of PCB board according to claim 2, characterized in that the acrylic plate (22) protrudes out of the lower frame (21).

7. The automatic exposure apparatus for PCB of claim 4, wherein the four corners of the top of the base plate (635) are fixed with vertical bars (6351), and the vertical bars (6351) pass through the connection plate (633) and are connected with the connection plate in a sliding manner.

8. The automatic exposure equipment of the PCB board as claimed in claim 2, wherein the end of the scraper (276) far away from the rotating shaft (274) is in a symmetrical structure.

9. The automated exposure apparatus for PCB board according to claim 2, wherein the width of the squeegee (276) is smaller than the width of the mylar film (26).

10. An automatic exposure method for a PCB, using the automatic exposure apparatus for a PCB according to any one of claims 1 to 9, comprising the steps of:

s1, adding a PCB substrate to the PCB placing groove;

s2, adhering and fixing the film sheet on the inner side of the Mylar film (26) through a transparent adhesive tape;

s3: based on a CCD camera (4), a film on the Mylar film (26) is positioned, and an X-axis linear motor (621), a Y-axis linear motor (622) and a rotating motor (623) are controlled through a controller (72) so that a material rack (61) corresponds to the film in position;

s4: controlling the stretching of the feeding cylinder (632), the stretching of the taking and placing cylinder (634) and the matching of an electric vacuum chuck (636), and placing the PCB substrate on the top layer of the rack (61) on the acrylic plate (22);

s5: the lifting cylinder (23) is controlled to drive the upper frame (24) to be combined with the lower frame (21);

s6: controlling a vacuum pump (25) to vacuumize the vacuum chamber, and enabling a mylar film (26) to extrude the film so that the film is in close contact with the PCB substrate to be exposed;

s7: the mylar film (26) and the film sheet are scraped and pressed through a bidirectional film scraping device (27), and air between the film sheet and the PCB substrate is exhausted;

s8: the exposure frame (2) is driven by the reciprocating linear motion device (3) to move in the exposure chamber (12), and the film is irradiated by the ultraviolet lamp (5) so as to complete the exposure of the PCB substrate.

Technical Field

The invention relates to the technical field of PCB exposure, in particular to automatic exposure equipment and method for a PCB.

Background

Current PCB board exposure device adopts artifically to scrape the film with the scraper blade to it with the film, the manual work most, makes the fine contact of film and PCB base plate, avoids having the bubble to produce of film and PCB base plate, and artifical material loading is with scraping off efficiency ratio lowly.

Therefore, it is necessary to provide a new automatic exposure apparatus and method for PCB board to solve the above technical problems.

Disclosure of Invention

In order to solve the technical problems, the invention provides automatic exposure equipment and method for a PCB.

The invention provides an automatic exposure device of a PCB, comprising:

a frame;

the exposure frame is provided with slide rails on the inner walls of two sides of the rack and is connected in the slide rails in a sliding manner;

the reciprocating linear motion device is arranged on the rack and used for driving the exposure rack to reciprocate along the slide rail;

the CCD camera is arranged on the frame and is right opposite to the exposure frame;

the ultraviolet lamp is arranged in the exposure chamber, and the ultraviolet lamp is arranged in the exposure chamber;

the feeding mechanism is arranged on one side of the rack and comprises a material rack, an adjusting and aligning device arranged at the bottom of the material rack and a manipulator arranged on the material rack;

the control box is mounted at the top of the rack, a circuit board is mounted inside the control box, the CCD camera is electrically connected with the circuit board, and a controller is mounted on the circuit board;

the exposure frame comprises a lower frame which is connected in a sliding rail in a sliding mode, an acrylic plate is installed in the center of the top of the lower frame, lifting cylinders are installed at four corners of the bottom of the lower frame, an output shaft of each lifting cylinder is fixedly connected with an upper frame which is matched with the lower frame, a vacuum chamber is formed after the upper frame and the lower frame are matched, the acrylic plate is located in the vacuum chamber, a vacuum pump for vacuumizing the vacuum chamber is installed inside the lower frame, a Mylar film is installed inside the upper frame, and a bidirectional film scraping device for scraping the Mylar film is installed at the top of the upper frame;

the bidirectional film scraping device comprises a mounting plate fixed on the upper frame, film scraping cylinders are symmetrically mounted at two ends of the mounting plate, the output shaft of the film scraping cylinder is fixed with a mounting seat, a rotating shaft is rotatably connected between the two mounting seats, one side of one of the mounting seats is fixed with a stepping motor, an output shaft of the stepping motor is fixedly connected with one end of the rotating shaft, the outer side of the rotating shaft is rotatably connected with a scraper, the outer side of the rotating shaft is sleeved with a bidirectional torsion spring, two ends of the bidirectional torsion spring are respectively clamped with the scraper and the rotating shaft, one end of the scraper is fixed with a baffle, the outer side of the rotating shaft is fixed with an arc-shaped plate, and the arc matches with the baffle, the arc includes first contact surface and second contact surface, contact switch is all installed at the top both ends of upper frame, contact switch, step motor and wiped film cylinder all with controller electric connection.

Preferably, the adjusting and aligning device comprises an X-axis linear motor, a Y-axis linear motor is fixed at the output end of the X-axis linear motor, a rotating motor is fixed at the output shaft of the Y-axis linear motor, and the X-axis linear motor, the Y-axis linear motor and the rotating motor are electrically connected with a circuit board.

Preferably, four corners of the material rack are provided with enclosing plates with L-shaped cross sections, a PCB placing groove is formed between the four enclosing plates, a bearing disc is connected inside the PCB placing groove in a sliding mode, a bearing spring is installed at the bottom of the bearing disc, and the bottom end of the bearing spring is fixedly connected with the bottom of the material rack.

Preferably, the manipulator is including fixing the L shape mounting bracket in work or material rest one side, the one end of L shape mounting bracket is fixed with the material loading cylinder, the output shaft of material loading cylinder is fixed with the connecting plate, the top of connecting plate is fixed with gets puts the cylinder, the output shaft of getting to put the cylinder is fixed with the bottom plate, electronic vacuum chuck is evenly installed to the bottom of bottom plate.

Preferably, the reciprocating linear motion device comprises a rack fixed on the inner wall of the rack, a motor is fixed at the bottom of the lower frame, a gear is fixed on an output shaft of the motor, and the gear is meshed with the rack.

Preferably, the acrylic plate protrudes out of the lower frame.

Preferably, the four corners of the top of the bottom plate are fixed with vertical rods, and the vertical rods penetrate through the connecting plate and are in sliding connection with the connecting plate.

Preferably, one end of the scraper far away from the rotating shaft is of a symmetrical structure.

Preferably, the width of the scraper is smaller than the width of the mylar film.

The invention also provides an automatic exposure method of the PCB, and the method comprises the following steps:

s1, adding a PCB substrate to the PCB placing groove;

s2, adhering and fixing the film sheet on the inner side of the Mylar film through a transparent adhesive tape;

s3: based on a CCD camera, positioning a film on a Mylar film, and controlling an X-axis linear motor, a Y-axis linear motor and a rotating motor through a controller to enable a material rack to correspond to the position of the film;

s4: controlling the stretching of the feeding cylinder and the stretching of the picking and placing cylinder and the matching of the electric vacuum chuck, and placing the PCB substrate on the top layer of the material rack on the acrylic plate;

s5: controlling the lifting cylinder to drive the upper frame and the lower frame to be combined;

s6: controlling a vacuum pump to vacuumize the vacuum chamber, and enabling the mylar film to extrude the film so that the film is in close contact with the PCB substrate to be exposed;

s7: scraping and pressing the Mylar film and the film sheet through a bidirectional film scraping device, and discharging air between the film sheet and the PCB substrate;

s8: the exposure frame is driven by the reciprocating linear motion device to move in the exposure chamber, and the film is irradiated by the ultraviolet lamp, so that the exposure of the PCB substrate is completed.

Has the advantages that: according to the invention, the PCB substrate is automatically fed through the arrangement of the feeding mechanism, particularly, the position of the PCB substrate on the uppermost layer is kept unchanged through the arrangement of the bearing spring, so that the structure of the manipulator is simple, the structure and the cost are reduced, the film and the PCB substrate are automatically scraped by the scraper through the arrangement of the bidirectional film scraping device, bubbles are prevented from existing between the film and the PCB substrate, and the exposure efficiency is higher compared with manual feeding and scraping treatment.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic structural view of the reciprocating linear motion device of the present invention;

FIG. 3 is a schematic view of the position of the slide rail according to the present invention;

FIG. 4 is a schematic structural view of a bidirectional knifing device of the invention;

FIG. 5 is a schematic structural view of a loading mechanism of the present invention;

FIG. 6 is a right side view of the loading mechanism of the present invention;

fig. 7 is a schematic view of the squeegee configuration of the invention.

Reference numbers in the figures: 1. a frame; 11. a slide rail; 12. an exposure chamber; 2. an exposure frame; 21. a lower frame; 22. acrylic plates; 23. a lifting cylinder; 24. an upper frame; 25. a vacuum pump; 26. a Mylar film; 27. a bidirectional film scraping device; 271. mounting a plate; 272. a film scraping cylinder; 273. a mounting seat; 274. a rotating shaft; 2741. an arc-shaped plate; 27411. a first contact surface; 27412. a second contact surface; 275. a stepping motor; 276. a squeegee; 2761. a baffle plate; 277. a bi-directional torsion spring; 3. a reciprocating linear motion device; 31. a rack; 32. an electric motor; 33. a gear; 4. a CCD camera; 5. an ultraviolet lamp; 6. a feeding mechanism; 61. a material rack; 611. enclosing plates; 612. a carrier tray; 613. a load bearing spring; 62. adjusting the alignment device; 621. an X-axis linear motor; 622. a Y-axis linear motor; 623. a rotating electric machine; 63. a manipulator; 631. an L-shaped mounting bracket; 632. a feeding cylinder; 633. a connecting plate; 634. a picking and placing cylinder; 635. a base plate; 6351. erecting a rod; 636. an electric vacuum chuck; 7. a control box; 71. a circuit board; 72. a controller; A. PCB board standing groove.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Specific implementations of the present invention are described in detail below with reference to specific embodiments.

Referring to fig. 1 to 7, an automatic exposure apparatus for PCB board according to an embodiment of the present invention includes a frame 1, an exposure frame 2, a reciprocating linear motion device 3, a CCD camera 4, an ultraviolet lamp 5, a feeding mechanism 6 and a control box 7,

the inner walls of the two sides of the rack 1 are respectively provided with a slide rail 11, and the exposure frame 2 is connected in the slide rails 11 in a sliding manner;

the reciprocating linear motion device 3 is arranged on the frame 1 and is used for driving the exposure frame 2 to reciprocate along the slide rail 11;

the CCD camera 4 is arranged on the frame 1, and the CCD camera 4 is arranged right opposite to the exposure frame 2;

an exposure chamber 12 is arranged in the machine frame 1, and the ultraviolet lamp 5 is arranged in the exposure chamber 12;

the feeding mechanism 6 is arranged at one side of the rack 1, and the feeding mechanism 6 comprises a material rack 61, an adjusting and aligning device 62 arranged at the bottom of the material rack 61 and a manipulator 63 arranged on the material rack 61;

it should be noted that, through the setting of feed mechanism 6, carry out automatic material loading to the PCB base plate, and then compare with manual feeding, exposure efficiency is higher.

The control box 7 is installed at the top of the rack 1, a circuit board 71 is installed inside the control box 7, the CCD camera 4 is electrically connected with the circuit board 71, and a controller 72 is installed on the circuit board 71;

the exposure frame 2 comprises a lower frame 21 connected in a sliding rail 11 in a sliding manner, an acrylic plate 22 is installed at the center of the top of the lower frame 21, lifting cylinders 23 are installed at four corners of the bottom of the lower frame 21, an output shaft of each lifting cylinder 23 is fixedly connected with an upper frame 24 matched with the lower frame 21, a vacuum chamber is formed after the upper frame 24 is matched with the lower frame 21, the acrylic plate 22 is located in the vacuum chamber, a vacuum pump 25 for vacuumizing the vacuum chamber is installed inside the lower frame 21, a mylar film 26 is installed inside the upper frame 24, and a bidirectional film scraping device 27 for scraping the mylar film 26 is installed at the top of the upper frame 24;

the bidirectional film scraping device 27 comprises a mounting plate 271 fixed on the upper frame 24, film scraping cylinders 272 are symmetrically mounted at two ends of the mounting plate 271, a mounting seat 273 is fixed on an output shaft of the film scraping cylinders 272, a rotating shaft 274 is rotatably connected between the two mounting seats 273, a stepping motor 275 is fixed on one side of one mounting seat 273, an output shaft of the stepping motor 275 is fixedly connected with one end of the rotating shaft 274, a scraping plate 276 is rotatably connected to the outer side of the rotating shaft 274, a bidirectional torsion spring 277 is sleeved on the outer side of the rotating shaft 274, two ends of the bidirectional torsion spring 277 are respectively clamped with the scraping plate 276 and the rotating shaft 274, a baffle 2761 is fixed at one end of the scraping plate 276, an arc plate 2741 is fixed on the outer side of the rotating shaft 274, the arc plate 2741 is matched with the baffle 2761, the arc plate 2741 comprises a first contact surface 27411 and a second contact surface 27412, and contact switches 277 are mounted at two ends of the top of the upper frame 24, the contact switch 277, the stepping motor 275 and the film scraping cylinder 272 are all electrically connected to the controller 72.

It should be noted that, through the setting of two-way knifing device 27, make the scraper blade automatic strickle off film and PCB base plate, avoid having the bubble between film and the PCB base plate, compare with artifical material loading and strickle off processing, the exposure efficiency is higher.

Adjust aligning device 62 and include X axle linear electric motor 621, X axle linear electric motor 621's output is fixed with Y axle linear electric motor 622, Y axle linear electric motor 622's output shaft is fixed with rotating electrical machines 623, and X axle linear electric motor 621, Y axle linear electric motor 622 and the equal electric connection circuit board 71 of rotating electrical machines 623.

The four corners of the material rack 61 are provided with enclosing plates 611 with L-shaped cross sections, a PCB placing groove A is formed between the four enclosing plates 611, a bearing plate 612 is connected inside the PCB placing groove A in a sliding mode, a bearing spring 613 is installed at the bottom of the bearing plate 612, and the bottom end of the bearing spring 613 is fixedly connected with the bottom of the material rack 61.

By providing the support spring 613, the position of the uppermost PCB substrate is maintained, the robot structure is simplified, and the structure and cost are reduced

The manipulator 63 comprises an L-shaped mounting frame 631 fixed on one side of the material frame 61, a feeding cylinder 632 is fixed at one end of the L-shaped mounting frame 631, a connecting plate 633 is fixed at an output shaft of the feeding cylinder 632, a taking and placing cylinder 634 is fixed at the top of the connecting plate 633, a bottom plate 635 is fixed at an output shaft of the taking and placing cylinder 634, and electric vacuum chucks 636 are uniformly installed at the bottom of the bottom plate 635.

The reciprocating linear motion device 3 comprises a rack 31 fixed on the inner wall of the frame 1, a motor 32 is fixed at the bottom of the lower frame 21, a gear 33 is fixed at the output shaft of the motor 32, the gear 33 is meshed with the rack 31, the gear 33 is driven by the motor 32 to rotate, and the exposure frame 2 can slide along the slide rail 11 as the gear 33 is meshed with the rack 31.

The acrylic plate 22 protrudes out of the lower frame 21, so that dust on the surface of the acrylic plate 22 can be cleaned conveniently.

Upright posts 6351 are fixed at four corners of the top of the bottom plate 635, and the upright posts 6351 penetrate through the connecting plate 633 and are slidably connected with the connecting plate, so that the bottom plate 635 can move up and down more stably.

The end of the scraper 276 far away from the rotating shaft 274 is of a symmetrical structure, so that the front and back scraping force of the scraper 276 is the same.

The width of the scraper 276 is less than the width of the mylar film 26.

An automatic exposure method for a PCB board comprises the following steps:

s1, adding a PCB substrate to the PCB placing groove;

it is to be emphasized that: since the load spring 613 satisfies hooke's law Δ F = k · Δ x, k =Δf/Δ x is obtained, k is the elastic coefficient of the load spring 613, the mass m of one PCB substrate, Δ F is the gravity of one PCB substrate, i.e., Δ F = mg, Δ x is the thickness of one PCB substrate, the elastic coefficient of the load spring 613 is determined according to the mass m and the thickness of the PCB substrate, and it is ensured that the position of the uppermost PCB substrate remains unchanged (within the deformation of the load spring 613 and the limitation of the fence 611 is satisfied) no matter how many PCB substrates are placed on the load tray 612;

s2, adhering and fixing the film sheet on the inner side of the Mylar film 26 through a transparent adhesive tape;

s3: based on the CCD camera 4, the film on the Mylar film 26 is positioned, the controller 72 controls the X-axis linear motor 621, the Y-axis linear motor 622 and the rotating motor 623, so that the material frame 61 corresponds to the position of the film, and the CCD camera 4 photographs the film to identify the position;

s4: controlling the stretching of the feeding cylinder 632, the stretching of the picking and placing cylinder 634 and the matching of the electric vacuum chuck 636, placing the PCB substrate on the top layer of the rack 61 on the acrylic plate 22, when the feeding cylinder 632 is stretched to the shortest position, the bottom plate 635 is opposite to the rack 61, the picking and placing cylinder 634 moves up and down to suck the PCB substrate to be exposed in combination with the electric vacuum chuck 636, and when the picking and placing cylinder 634 is stretched to the maximum position, the picking and placing cylinder 634 moves up and down to place the PCB substrate to be exposed in combination with the electric vacuum chuck 636 on the acrylic plate 22;

s5: controlling the lifting cylinder 23 to drive the upper frame 24 to be combined with the lower frame 21, so as to seal the vacuum chamber;

s6: controlling a vacuum pump 25 to vacuumize the vacuum chamber, and enabling the mylar film 26 to extrude the film so that the film is in close contact with the PCB substrate to be exposed;

s7: the mylar film 26 and the film are scraped and pressed through the bidirectional film scraping device 27, air between the film and the PCB substrate is exhausted, when the film scraping cylinder 272 extends, the stepping motor 275 rotates in the forward direction, the baffle 2761 is in contact with the first contact surface 27411, the bidirectional torsion spring 277 stores energy in the forward direction, when the film scraping cylinder 272 contracts, the stepping motor 275 rotates in the reverse direction, the baffle 2761 is in contact with the second contact surface 27412, the bidirectional torsion spring 277 stores energy in the reverse direction, and the forward and reverse rotation of the stepping motor 275 is controlled by the contact switch 277;

s8: the exposure frame 2 is driven by the reciprocating linear motion device 3 to move in the exposure chamber 12, and the film is irradiated by the ultraviolet lamp 5, so that the exposure of the PCB substrate is completed.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.