JP2009040016A - Screen printing method and screen printing machine - Google Patents

Abstract

Provided is a screen printing method and a screen printing machine that can reliably hold even a thin circuit board, have high printing accuracy, and are less likely to cause “bleeding” in a solder printed portion of the circuit board. This is the issue.
A screen printing method includes a clamping step of clamping a circuit board B before printing from above and below by a board clamping device 5 having board pressing members 5a and 5b and a board support member 5c; A press-contacting process in which the screen mask 420c disposed above the circuit board B is press-contacted in the vertical direction to bring it into a press-contact state, and the substrate pressing members 5a and 5b are extracted from between the press-contact circuit board B and the screen mask 420c And a pressing step for releasing the press-contact state while keeping the circuit board B and the screen mask 420c in close contact with each other, and a printing step for printing the cream solder on the circuit board B through the screen mask 420c.
[Selection] Figure 1

Description

  The present invention relates to a screen printing method and a screen printing machine for printing cream solder on a circuit board through a screen mask.

  When printing cream solder on a circuit board, it is necessary to hold the circuit board and transport it to a predetermined printing position. For this reason, conventionally, the circuit board is held by sandwiching two opposite edges of the circuit board from the side. However, when the board thickness of the circuit board is thin, the rigidity of the circuit board cannot withstand the clamping force, and the circuit board may bend in the vertical direction. When the circuit board bends, it becomes difficult to convey the circuit board. In addition, if the circuit board is bent, it is difficult to focus the camera when imaging the circuit board, and the recognition accuracy may be reduced. In addition, production efficiency may be reduced due to an image recognition error.

Therefore, Patent Document 1 introduces a screen printer that holds a circuit board by pressing the four edges of the circuit board from the side. According to the screen printing machine described in the document, it is possible to suppress the circuit board from being bent as compared with the type of the screen printing machine that sandwiches two edges of the circuit board.
JP-A-10-119241 JP 2006-004973 A

  However, even the screen printing machine described in Patent Document 1 does not have sufficient circuit board retention. Therefore, Patent Document 2 introduces an up-and-down holding type screen printing machine that holds a circuit board by sandwiching two opposite edges of the circuit board from above and below.

  FIG. 27 shows a schematic diagram of a vertical holding type screen printing machine before the circuit board is clamped. FIG. 28 shows a schematic diagram of the screen printing machine while the circuit board is being clamped. FIG. 29 shows a schematic diagram of the screen printing machine during printing.

  27, 28, and 29, the screen printing machine 100 includes a pair of left and right belt conveyors 101a and 101b, a pair of left and right substrate pressing members 102a and 102b, and a pair of left and right cylinder devices 103a and 103b. And a screen mask 104.

  The circuit board B0 is placed between the belt conveyors 101a and 101b in a bridging manner. The substrate pressing member 102a can approach the belt conveyor 101a from above by the cylinder device 103a. Similarly, the substrate pressing member 102b can be approached from above with respect to the belt conveyor 101b by the cylinder device 103b.

  As shown in FIG. 27, the circuit board B0 is carried into a predetermined position by the belt conveyors 101a and 101b. As shown in FIG. 28, the carried circuit board B0 is sandwiched between the belt conveyors 101a and 101b and the board pressing members 102a and 102b. In this state, the position correction of the circuit board B0 is executed. As shown in FIG. 29, the circuit board B0 after the position correction is raised to the height of the screen mask 104 while being sandwiched between the belt conveyors 101a and 101b and the board pressing members 102a and 102b. In this state, cream solder is applied to the circuit board B0. That is, cream solder is placed on the upper surface of the screen mask 104. Further, above the screen mask 104, a squeegee device (not shown) that can slide on the upper surface of the screen mask 104 is disposed. The screen mask 104 is provided with printing holes (not shown). The cream solder on the upper surface of the screen mask 104 is pushed into the printing hole by the squeegee device. Cream solder is applied to a predetermined position of the circuit board B0 through the printing hole.

  However, as shown in FIG. 29, a gap C0 is interposed between the upper surface of the circuit board B0 and the lower surface of the screen mask 104. The gap C0 is caused by the plate thickness of the claw portions of the substrate pressing members 102a and 102b, and is inevitably generated. For this reason, at the time of printing, there is a possibility that a deviation occurs between the print target position of the circuit board B0 and the actual print position. That is, the conventional screen printing method and screen printing machine have low printing accuracy. Further, the cream solder wraps around the lower surface of the screen mask, so that “bleeding” may occur in the solder printed portion of the circuit board.

  The screen printing method and screen printing machine of the present invention have been completed in view of the above problems. Therefore, the present invention provides a screen printing method and screen that can reliably hold even a thin circuit board, have high printing accuracy, and are less likely to cause “bleeding” in a solder printed portion of the circuit board. An object is to provide a printing press.

  (1) In order to solve the above-described problem, the screen printing method of the present invention includes a sandwiching step of sandwiching a circuit board before printing from above and below by a substrate sandwiching device having a substrate pressing member and a substrate support member, A pressure-contacting process in which a circuit board and a screen mask disposed above the circuit board are pressure-contacted in a vertical direction to bring them into a pressure-contact state, and the substrate pressing member is extracted from between the circuit board and the screen mask in the pressure-contact state An extraction step, a pressure release step for releasing the pressure contact state while the circuit board and the screen mask are kept in close contact, and a printing step for printing cream solder on the circuit board through the screen mask. (Corresponding to claim 1).

  According to the screen printing method of the present invention, when the circuit board is transported to a predetermined printing position, the circuit board can be firmly held by the board holding device. When the cream solder is printed on the circuit board, the board pressing member of the board holding device can be removed from above the circuit board.

  Further, according to the screen printing method of the present invention, in the clamping step, the circuit board can be clamped from above and below by the board clamping device. For this reason, even a thin circuit board can be reliably held.

  Further, according to the screen printing method of the present invention, the pressure contact state can be released in the state where the circuit board and the screen mask are brought into close contact with each other in the pressure release process. For this reason, in a printing process, cream solder can be printed on a circuit board in the state where a circuit board and a screen mask were stuck. That is, the gap C0 as shown in FIG. 29 does not occur between the circuit board and the screen mask. For this reason, the screen printing method of the present invention has high printing accuracy. In addition, there is little risk of “bleeding” in the solder printed portion of the circuit board.

  In addition, according to the screen printing method of the present invention, the substrate pressing member is extracted in the extraction step while maintaining the pressure contact state created in the pressure contact step. That is, the substrate pressing member is extracted in a state where the pressure contact force is constantly applied to the circuit board. For this reason, even if a board | substrate holding | suppressing member is extracted, there is little possibility that a circuit board will bend. Also in this point, the screen printing method of the present invention has high printing accuracy. In addition, there is little risk of “bleeding” in the solder printed portion of the circuit board.

  (2) Preferably, in the configuration of the above (1), the circuit board and the screen mask after printing are again pressed against each other from above and below to bring them into the pressed state, and the circuit in the pressed state It is preferable to have a configuration including an insertion step of inserting the substrate pressing member between the substrate and the screen mask and a peeling step of peeling the screen mask from the circuit board (corresponding to claim 2).

  The printed circuit board is attached to the screen mask by the adhesive force of cream solder. For this reason, it is necessary to peel off the screen mask from the circuit board. In the screen printing machine of the above-mentioned patent document 1, the screen mask was peeled off from the circuit board with the holding claw. That is, first, the circuit board is fixed by bringing the pressing claw into contact with the side surface of the circuit board so as to be pierced. Next, the screen mask is relatively separated from the fixed circuit board. In this way, the screen mask was peeled off from the circuit board.

  However, according to the screen printing machine of patent document 1, it is necessary to abut the pressing claw accurately on the side surface of the circuit board. However, the area of the side surface of the circuit board is small. In particular, when the thickness of the circuit board is thin, the area of the side surface is further reduced. For this reason, the method of fixing the side surfaces with the holding claws lacks reliability.

  Further, at the time of peeling, the circuit board is pulled to the screen mask by the adhesive force of the cream solder. However, the contact direction of the pressing claw and the separation direction of the screen mask intersect each other in a substantially vertical direction. For this reason, if the circuit board is not fixed with a relatively large contact force, the circuit board may be pulled by the screen mask and come off from the holding claws. Also in this respect, the method of fixing the side surface with the pressing claws lacks reliability.

  On the other hand, according to this configuration, the substrate pressing member is inserted between the circuit board and the screen mask in the insertion step while maintaining the pressure contact state created in the re-pressure contact step. In the peeling step, the screen mask is peeled from the circuit board from this state. The substrate pressing member is pressing not the narrow side but the vast upper surface (printing surface). For this reason, this structure has high operation reliability when peeling a screen mask from a circuit board.

  Further, the pressure-contact direction of the substrate pressing member and the peeling direction are substantially parallel. Alternatively, it intersects in a direction other than substantially vertical. For this reason, there is little possibility that the circuit board and the board pressing member are disengaged in the peeling step. Also in this point, this configuration has high operation reliability when the screen mask is peeled from the circuit board.

  Further, if the substrate pressing member is inserted between the circuit board and the screen mask while maintaining the pressure contact state, it is possible to suppress the screen mask from being peeled off from the circuit board at once. Therefore, according to this configuration, the printing accuracy is increased. In addition, the possibility of “smearing” in the solder printed portion of the circuit board is reduced.

  (3) Preferably, in the configuration of (1) or (2) above, in the pressure contact step, a non-pressure contact region between the circuit board and the screen mask is not pressed between the circuit board and the screen mask. In the extraction step, the substrate pressing member is preferably extracted from the non-pressure contact region (corresponding to claim 3).

  According to this configuration, in the pressure-contacting process, a non-pressure-contacting region where the two members are not pressure-contacted (may be in close contact) is formed between the circuit board and the screen mask. The non-pressure contact region is not in the pressure contact state. For this reason, it is easy to ensure a gap between the circuit board and the screen mask in the non-pressure contact region. In the extraction process, the substrate pressing member is extracted using the non-pressure contact area. According to this configuration, the substrate pressing member can be more reliably extracted from between the circuit board and the screen mask in the extraction process.

  (4) Preferably, in the configuration of (2) or (3), non-pressure welding in which the circuit board and the screen mask are not in pressure contact between the circuit board and the screen mask in the re-pressure welding step. A region is formed, and the substrate pressing member is preferably inserted into the non-pressure contact region in the inserting step (corresponding to claim 4).

  According to this configuration, in the re-pressure contact process, a non-pressure contact region in which the two members are not in pressure contact (may be in close contact) is formed between the circuit board and the screen mask. The non-pressure contact region is not in the pressure contact state. For this reason, it is easy to ensure a gap between the circuit board and the screen mask in the non-pressure contact region. In the insertion step, the substrate pressing member is inserted using the non-pressure contact area. According to this configuration, the board pressing member can be more reliably inserted between the circuit board and the screen mask in the insertion step.

  (5) Preferably, in any one of the configurations (1) to (4), the press contact state is formed by a pressing device that presses the screen mask against the circuit board. 5). According to this configuration, the press contact state can be formed by the pressing force.

  (6) Preferably, in any one of the configurations (1) to (4), the pressure contact state is formed by a suction device that attracts the screen mask to the circuit board. 6). According to this configuration, the pressure contact state can be formed by the suction force.

  (7) Moreover, in order to solve the said subject, the screen printing machine of this invention has a board | substrate pressing member and a board | substrate support member, The board | substrate clamping apparatus which can clamp a circuit board from an up-down direction, and this circuit A screen printing machine comprising: a screen mask disposed above a substrate; and a pressure welding device capable of pressure-contacting the screen mask to the circuit board, wherein cream solder is applied to the circuit board via the screen mask. In the printing position for printing, the screen mask is set so as to be substantially planar in the horizontal direction, and the circuit sandwiched by the substrate clamping device by the pressing force supplied by the pressing device before printing. The lower surface of the screen mask is brought into pressure contact with the upper surface of the substrate, and the substrate holding member of the substrate clamping apparatus is removed from the upper surface of the circuit substrate as it is, and placed at the printing position. The piezoelectric contact force by removing from the screen mask, wherein the keep in close and circuit board top surface and the screen mask lower surface (corresponding to claim 7).

  According to the screen printing machine of the present invention, when the circuit board is conveyed to a predetermined printing position, the circuit board can be firmly held by the board holding device. When the cream solder is printed on the circuit board, the board pressing member of the board holding device can be removed from above the circuit board.

  Further, according to the screen printing machine of the present invention, the circuit board can be sandwiched from above and below by the substrate sandwiching device. For this reason, even a thin circuit board can be reliably held.

  Further, according to the screen printing machine of the present invention, the screen mask is set to be substantially planar in the horizontal direction at the printing position. For this reason, even if the pressure contact force of the pressure welding device is removed, it is possible to maintain a state in which the upper surface of the circuit board and the lower surface of the screen mask are in close contact. Therefore, cream solder can be printed on the circuit board in a state where the upper surface of the circuit board and the lower surface of the screen mask are in close contact with each other during printing. That is, the gap C0 as shown in FIG. 29 does not occur between the upper surface of the circuit board and the lower surface of the screen mask. For this reason, the screen printing machine of the present invention has high printing accuracy. In addition, there is little risk of “bleeding” in the solder printed portion of the circuit board.

  Further, according to the screen printing machine of the present invention, the substrate pressing member is extracted while the lower surface of the screen mask is pressed against the upper surface of the circuit board. That is, the substrate pressing member is extracted in a state where the pressure contact force is constantly applied to the circuit board. For this reason, even if a board | substrate holding | suppressing member is extracted, there is little possibility that a circuit board will bend. Also in this point, the screen printer of the present invention has high printing accuracy. In addition, there is little risk of “bleeding” in the solder printed portion of the circuit board.

  (8) Preferably, in the configuration of the above (7), the press contact device may be a pressing device that presses the screen mask against the circuit board (corresponding to claim 8). According to this configuration, the screen mask can be pressed against the circuit board by the pressing force.

  (9) Preferably, in the configuration of the above (7), the pressure contact device is a suction device that attracts the screen mask to the circuit board (corresponding to claim 9). According to this configuration, the pressure contact state can be formed by the suction force.

  According to the screen printing method and the screen printing machine of the present invention, even a circuit board having a thin plate thickness can be reliably held. Further, according to the screen printing method and the screen printing machine of the present invention, the printing accuracy is increased. In addition, the possibility of “smearing” in the solder printed portion of the circuit board is reduced.

  Embodiments of a screen printing method and a screen printing machine according to the present invention will be described below.

<First embodiment>
[Configuration of screen printer]
First, the configuration of the screen printing machine of this embodiment will be described. FIG. 1 shows a side view of the screen printing machine of the present embodiment. As shown in FIG. 1, the screen printing machine 1 according to the present embodiment includes a movable unit 8, a support unit 9, and a printing unit 10.

  The support unit 9 mainly includes a lifting table 90, a support column 91, and a lifting device 92. The support column 91 extends in the vertical direction. A guide rail 910 is disposed on the front surface of the column 91. The guide rail 910 extends in the vertical direction.

  The lifting table 90 includes a flat frame portion 900 and a guided column 901. The guided column 901 extends in the vertical direction. The guided column 901 includes a guided recess 902 and a nut portion 903. The guided recessed portion 902 is engaged with the guide rail 910. The guided recessed portion 902 is slidable in the vertical direction along the guide rail 910. The flat frame portion 900 is disposed above the guided column 901. The flat frame portion 900 extends in the horizontal direction.

  The lifting device 92 includes a motor 920 and a ball screw 921. The nut portion 903 of the guided column 901 is screwed into the ball screw 921. When the motor 920 moves, the ball screw 921 rotates. For this reason, the nut portion 903 is movable along the extending direction of the ball screw 921. Therefore, the elevating table 90 can move in the vertical direction while the guided recess 902 is guided by the guide rail 910 by the driving force transmitted to the nut portion 903.

  The movable portion 8 mainly includes the side clamp device 2, the positioning device 3, the substrate clamping device 5, the side clamp cylinder device 40, the substrate pressing member cylinder devices 41a and 41b, the first table 60, the second table 61, and the first table 61. Three tables 62 and a conveyor device 7 are provided. The movable part 8 is mounted on the lifting table 90. For this reason, the movable part 8 can move in the vertical direction together with the lifting table 90.

  The third table 62 has a rectangular plate shape. The third table 62 is mounted on the upper surface of the flat frame portion 900 via a ball bearing 620. For this reason, the third table 62 can move back and forth and right and left with respect to the flat frame portion 900. Moreover, it can rotate in the horizontal direction.

  A board pressing member guide rail 623 extending in the front-rear direction is embedded in the third table 62. In addition, a cam guide rail 621 extending in the front-rear direction is disposed on the upper surface of the third table 62. A pair of front and rear cam members 622 are engaged with the cam guide rail 621. The pair of cam members 622 can slide in the front-rear direction along the cam guide rails 621. The cam member 622 has a right triangular shape. The cam member 622 has an inclined surface that descends from the rear toward the front.

  The second table 61 has a rectangular plate shape. The second table 61 is disposed substantially at the center of the third table 62. The second table 61 is guided by a guide rod 605 described later, and can move only in the vertical direction. A pair of rollers 610 are disposed on the lower surface of the second table 61 so as to be separated from each other in the front-rear direction. The pair of rollers 610 can roll on the inclined surfaces of the pair of cam members 622. For this reason, the 2nd table 61 can be raised by moving the cam member 622 ahead. Conversely, the second table 61 can be lowered by moving the cam member 622 backward.

  The first table 60 includes an elevating member 601, a nut portion 602, a ball screw 603, a motor 604, and a guide rod 605. The elevating member 601 has a rectangular plate shape. The nut portion 602 is disposed on the lower surface of the elevating member 601. The motor 604 is housed inside the third table 62 and the flat frame portion 900. The ball screw 603 is disposed immediately above the motor 604. The ball screw 603 passes through the second table 61. A nut portion 602 is screwed onto the upper end of the ball screw 603. The guide rod 605 is disposed through the second table 61 between the lower surface of the elevating member 601 and the upper surface of the third table 62. The guide rod 605 can be expanded and contracted in the vertical direction. The guide rods 605 are disposed at the four corners on the lower surface of the elevating member 601. As described above, the guide rod 605 guides the vertical movement of the second table 61. When the motor 604 is driven, the ball screw 603 rotates. For this reason, the screwing amount of the nut part 602 with respect to the ball screw 603 changes. The elevating member 601 can move in the vertical direction by the change in the screwing amount.

  The substrate clamping device 5 includes a pair of substrate pressing members 5a and 5b and a substrate support member 5c. The substrate pressing member 5 a is disposed opposite to the rear edge of the third table 62, and the substrate pressing member 5 b is disposed opposite to the front edge of the third table 62. In FIG. 2, the perspective view of the upper part of the movable part 8 of the screen printer 1 of this embodiment is shown. FIG. 3 shows an exploded perspective view of the upper part of the movable part 8 of the screen printing machine 1. In FIG. 2, the substrate pressing member 5a is shown in a transparent manner for convenience of explanation.

  The substrate pressing member 5a includes a base portion 50a and a claw portion 51a. The base 50a has a prismatic shape. A lower end portion of the base portion 50 a is embedded in the third table 62. The lower end of the base 50a is engaged with the board pressing member guide rail 623. Therefore, the base 50a, that is, the substrate pressing member 5a is movable in the front-rear direction along the substrate pressing member guide rail 623. The claw portion 51a has a thin plate shape. The claw portion 51a protrudes forward from the upper edge of the base portion 50a.

  The configuration of the substrate pressing member 5b is the same as the configuration of the substrate pressing member 5a. That is, the substrate pressing member 5b includes a base portion 50b and a claw portion 51b. The base 50b, that is, the substrate pressing member 5b, is movable in the front-rear direction along the substrate pressing member guide rail 623. The claw portion 51b has a thin plate shape. The claw portion 51b protrudes rearward from the upper edge of the base portion 50b.

  The substrate support member 5c is pin-shaped and protrudes from the upper surface of the elevating member 601 by a predetermined number. For this reason, the board | substrate support member 5c is movable to an up-down direction with the raising / lowering member 601. As shown in FIG. The board support member 5c can support the lower surface of the circuit board B described later by moving up.

  The side clamp device 2 includes a slave clamp 2a and a reference clamp 2b. The slave clamp 2 a is disposed at the rear edge of the second table 61, and the reference clamp 2 b is disposed at the front edge of the second table 61. The dependent clamp 2a has a flat plate shape whose upper end protrudes forward. The reference clamp 2b has a flat plate shape whose upper end protrudes rearward.

  The conveyor device 7 includes a pair of belt conveyors 7a and 7b. The belt conveyor 7a is disposed in the vicinity of the upper edge of the front surface of the dependent clamp 2a. The belt conveyor 7a extends in the left-right direction (hereinafter, left and right are defined with reference to the case of looking from the front to the rear). The belt conveyor 7a includes an endless annular belt 70a. The belt conveyor 7b is disposed in the vicinity of the upper edge of the rear surface of the reference clamp 2b. The belt conveyor 7b extends in the left-right direction so as to face the belt conveyor 7a. The belt conveyor 7b includes an endless annular belt 70b. A rectangular plate-like circuit board B is placed on the pair of belt conveyors 7a and 7b in a bridging manner.

  The positioning device 3 includes a ball screw 30 and a nut portion 31. The ball screw 30 is embedded in the second table 61. The ball screw 30 extends in the front-rear direction. A pair of ball screws 30 are arranged in the left-right direction. The nut portion 31 includes a nut body 310 and a bracket 311. The bracket 311 has a flat plate shape. The bracket 311 is juxtaposed behind the dependent clamp 2a. A pair of nut main bodies 310 are disposed in the left-right direction at the lower edge of the rear surface of the bracket 311. The pair of nut main bodies 310 are respectively screwed into the pair of ball screws 30.

  The side clamp cylinder device 40 includes a cylinder body 400 and a piston rod 401. The cylinder body 400 has a cylindrical shape. A pair of left and right cylinder bodies 400 are arranged on the rear surface of the bracket 311. Air can be supplied and discharged into the cylinder body 400 from an air pipe (not shown). The piston rod 401 extends in the front-rear direction. The rear end of the piston rod 401 is accommodated in the cylinder body 400. The front end of the piston rod 401 passes through the bracket 311 and is connected to the rear surface of the dependent clamp 2a.

  The substrate pressing member cylinder device 41a includes a cylinder body 410a and a piston rod 411a. The cylinder body 410a has a cylindrical shape. A pair of left and right cylinder bodies 410a are arranged on the rear surface of the bracket 412a that protrudes from the vicinity of the rear edge of the third table 62. Air can be supplied and discharged from an air pipe (not shown) into the cylinder body 410a. The piston rod 411a extends in the front-rear direction. The rear end of the piston rod 411a is accommodated in the cylinder body 410a. The front end of the piston rod 411a is connected to the rear surface of the base 50a of the substrate pressing member 5a.

  The configuration of the substrate pressing member cylinder device 41b is the same as the configuration of the substrate pressing member cylinder device 41a. That is, the substrate pressing member cylinder device 41b includes a cylinder body 410b and a piston rod 411b. A pair of left and right cylinder bodies 410b are arranged on the front surface of a bracket 412b protruding from the vicinity of the front edge of the third table 62. Air can be supplied and discharged into the cylinder body 410b. The piston rod 411b extends in the front-rear direction. The front end of the piston rod 411b is accommodated in the cylinder body 410b. The rear end of the piston rod 411b is connected to the front surface of the base portion 50b of the substrate pressing member 5b.

  The printing unit 10 includes a screen device 42, a squeegee device 43, and a pressing device 44. The printing unit 10 is disposed on a gantry (not shown). The printing unit 10 is disposed above the movable unit 8.

  The screen device 42 is disposed above the substrate pressing members 5a and 5b. The screen device 42 includes a pair of front and rear frames 420a and 420b and a screen mask 420c. The screen mask 420c is installed between the pair of frames 420a and 420b.

  The squeegee device 43 is disposed above the screen device 42. The squeegee device 43 includes a squeegee cylinder device 432, a squeegee body 433, and a guide member 434. The guide member 434 is disposed on the gantry. The guide member 434 extends in the front-rear direction. The squeegee cylinder device 432 is disposed on the guide member 434. The squeegee cylinder device 432 is slidable in the front-rear direction with respect to the guide member 434. The squeegee body 433 has a flat plate shape that is long in the left-right direction. The squeegee body 433 is fixed to the piston rod of the squeegee cylinder device 432. The squeegee body 433 is driven in the vertical direction by the squeegee cylinder device 432.

  The pressing device 44 includes a pair of front and rear pressing plate cylinder devices 440a and 440b and a pair of front and rear pressing plates 441a and 441b. The pressing plate cylinder device 440 a is disposed on the guide member 434. The pressing plate cylinder device 440 a can slide in the front-rear direction with respect to the guide member 434. The pressing plate cylinder device 440 a is disposed behind the squeegee cylinder device 432. Similarly, the pressing plate cylinder device 440 b is disposed on the guide member 434. The pressing plate cylinder device 440b can slide in the front-rear direction with respect to the guide member 434. The pressing plate cylinder device 440 b is disposed in front of the squeegee cylinder device 432. The pressing plate 441a has a flat plate shape that is long in the left-right direction. The pressing plate 441a is fixed to the piston rod of the pressing plate cylinder device 440a. The pressing plate 441a is driven in the vertical direction by the pressing plate cylinder device 440a. The pressing plate 441b has a flat plate shape that is long in the left-right direction. The pressing plate 441b is fixed to the piston rod of the pressing plate cylinder device 440b. The pressing plate 441b is driven in the vertical direction by the pressing plate cylinder device 440b.

[Screen printing method]
Next, the screen printing method of this embodiment will be described. The screen printing method of the present embodiment includes a clamping process, a press-contacting process, a drawing-out process, a press-contact releasing process, a printing process, a re-pressing process, an inserting process, and a peeling process.

  First, the clamping process will be described. In FIG. 4, the schematic diagram of the 1st step of the clamping process of the screen printing method of this embodiment is shown. FIG. 5 shows a schematic diagram of the second stage of the process. FIG. 6 shows a schematic diagram of the third stage of the process. FIG. 7 shows a schematic diagram of the fourth stage of the process and the first stage of the pressure welding process.

  In this step, first, the circuit board B is placed on a pair of belt conveyors 7a and 7b from a stocker (not shown) as shown in FIG. Next, the pair of belt conveyors 7a and 7b are driven to convey the circuit board B to a predetermined position (just below a printing position described later). During transport, the front-rear direction interval between the sub-clamp 2a and the reference clamp 2b is smaller than the front-rear direction width of the circuit board B in order to suppress interference between the circuit board B, the sub-clamp 2a, and the reference clamp 2b. It is set slightly larger.

  Next, the substrate pressing member 5a is protruded by the substrate pressing member cylinder device 41a, and the substrate pressing member 5b is protruded by the substrate pressing member cylinder device 41b. Specifically, the board pressing member 5a is protruded forward to a position where the front edge of the claw 51a reaches the rear edge of the circuit board B. And the board | substrate holding | suppressing member 5b is protruded back to the position where the nail | claw part 51b rear edge approachs the circuit board B front edge upper part.

  Next, as shown in FIG. 5, the ball screw 30 is rotated and the nut portion 31 is moved forward. A slave clamp 2 a is connected to the nut portion 31 via a side clamp cylinder device 40. For this reason, the dependent clamp 2a also moves forward together with the nut portion 31. When the slave clamp 2a moves, the distance between the slave clamp 2a and the reference clamp 2b is reduced. For this reason, the circuit board B is pushed forward by the subordinate clamp 2a and moves forward, and is sandwiched between the subordinate clamp 2a and the reference clamp 2b. After clamping, the air of the side clamp cylinder device 40 is leaked, and the clamping force to the circuit board B is removed.

  Next, as shown in FIG. 6, the 1st table 60 is raised and the board | substrate support member 5c is raised. In addition, the second table 61 shown in FIG. 1 is raised, and the slave clamp 2a and the reference clamp 2b are raised. Then, as shown in FIG. 7, the upper surface of the subordinate clamp 2a and the upper surface of the rear edge of the circuit board B are abutted against the lower surface of the claw portion 51a of the substrate pressing member 5a. In addition, the upper surface of the reference clamp 2b and the upper surface of the front edge of the circuit board B are abutted against the lower surface of the claw portion 51b of the substrate pressing member 5b. That is, the circuit board B is sandwiched from above and below by the pair of board pressing members 5a and 5b and the board support member 5c. Then, air is supplied to the side clamp cylinder device 40, and the circuit board B is sandwiched between the slave clamp 2a and the reference clamp 2b from the front-rear direction. Thereafter, the horizontal position of the circuit board B is corrected. That is, an error in the horizontal direction of the circuit board B with respect to a printing position described later is corrected.

  Next, the pressure contact process will be described. FIG. 8 shows a schematic diagram of the second stage of the press-contact process of the screen printing method of the present embodiment and the first stage of the extraction process. As shown in FIGS. 7 and 8, in this step, the pressing plate cylinder devices 440a and 440b are driven to lower the pressing plates 441a and 441b. And the center part in the front-back direction of the lower surface of the screen mask 420c is pressed downward by the pressing plates 441a and 441b. Here, the rear edge of the screen mask 420c is fixed by a frame 420a, and the front edge of the screen mask 420c is fixed by a frame 420b. For this reason, only the center part in the front-rear direction of the screen mask 420c protrudes downward by the pressing force of the pressing plates 441a and 441b. The central portion of the screen mask 420c in the front-rear direction is pressed against the circuit board B. Then, as shown in FIG. 8, a pair of front and rear non-pressure contact areas A are defined between the circuit board B and the screen mask 420c. In the non-pressure contact area A, a gap is formed between the screen mask 420c and the circuit board B. The front edge of the claw portion 51a of the substrate pressing member 5a is disposed in the rear non-pressure contact area A. For this reason, the nail | claw part 51a is not contact | abutting to the screen mask 420c. In addition, the rear edge of the claw portion 51b of the substrate pressing member 5b is disposed in the front non-pressure contact area A. For this reason, the nail | claw part 51b is not contact | abutting to the screen mask 420c.

  Next, the extraction process will be described. FIG. 9 shows a schematic diagram of the second stage of the extraction process of the screen printing method of the present embodiment and the first stage of the pressure release process. As shown in FIG. 8 and FIG. 9, in this step, the substrate pressing member 5a is retracted by the substrate pressing member cylinder device 41a, and the substrate pressing member 5b is retracted by the substrate pressing member cylinder device 41b. Specifically, the substrate pressing member 5a is retracted backward to a position where the claw portion 51a does not interfere with the dependent clamp 2a. At the same time, the substrate pressing member 5b is retracted forward to a position where the claw portion 51b does not interfere with the reference clamp 2b. Thus, by retracting the board pressing members 5a and 5b, the circuit board B is sandwiched from above and below by the pressing plates 441a and 441b and the board support member 5c.

  Next, the pressure contact releasing process will be described. As shown in FIG. 9, in the first stage of this process, the first table 60 is raised and the substrate support member 5c is raised. At the same time, the second table 61 shown in FIG. 1 is raised, and the slave clamp 2a and the reference clamp 2b are raised. In addition, the pressing plate cylinder devices 440a and 440b are driven to raise the pressing plates 441a and 441b. The substrate support member 5c, the slave clamp 2a, the reference clamp 2b, and the pressing plates 441a and 441b are raised simultaneously. Therefore, the circuit board B and the screen mask 420c are held between the pressing plates 441a and 441b and the board support member 5c from the vertical direction. In addition, the circuit board B remains sandwiched by the slave clamp 2a and the reference clamp 2b from the front-rear direction.

  In FIG. 10, the schematic diagram of the 2nd step of the press-contact cancellation | release process of the screen printing method of this embodiment is shown. FIG. 11 is a schematic diagram of the printing process, which is the third stage of the process. As shown in FIG. 10, in the second stage, the substrate support member 5c, the slave clamp 2a, the reference clamp 2b, and the circuit board B are stopped at the printing position H1. In the printing position H1, the central portion in the front-rear direction that protrudes downward is moved back to a substantially flat shape. That is, at the printing position H1, the screen mask 420c is substantially flat in the horizontal direction across the pair of frames 420a and 420b. On the other hand, the upper surface of the circuit board B is also planar. For this reason, in the printing position H1, the upper surface of the circuit board B and the lower surface of the screen mask 420c can be brought into full surface contact. In other words, it can be in close contact. In the third stage, the pressing plates 441a and 441b are further raised from the printing position H1. Then, the pressing plates 441a and 441b are separated from the screen mask 420c. By the separation, the pressure contact state between the circuit board B and the screen mask 420c is released. That is, the circuit board B and the screen mask 420c are in close contact with each other, but are not in pressure contact with each other.

  Next, the printing process will be described. As shown in FIG. 11, the squeegee cylinder device 432 is driven and the squeegee main body 433 is lowered in this step. Then, the squeegee body 433 is brought into contact with the screen mask 420c. Then, the squeegee cylinder device 432, that is, the squeegee main body 433 is moved along the guide member 434. Here, cream solder is disposed on the upper surface of the screen mask 420c. The screen mask 420c has a printing hole (not shown). The cream solder on the upper surface of the screen mask 420c is pushed into the printing hole by the squeegee body 433. Cream solder is applied to a predetermined position of the circuit board B through the printing holes.

  Next, the re-pressure contact process will be described. In the first stage of the re-welding process, the state shown in FIG. That is, the pressing plates 441a and 441b are lowered again. Then, the circuit board B and the screen mask 420c are sandwiched from above and below by the pressing plates 441a and 441b and the board support member 5c. In the second stage of this process, the state shown in FIG. That is, the first table 60 is lowered and the substrate support member 5c is lowered. At the same time, the second table 61 shown in FIG. 1 is lowered, and the slave clamp 2a and the reference clamp 2b are lowered. In addition, the pressing plates 441a and 441b are further lowered. The substrate support member 5c, the subordinate clamp 2a, the reference clamp 2b, and the pressing plates 441a and 441b are lowered simultaneously. Therefore, the circuit board B and the screen mask 420c are held between the pressing plates 441a and 441b and the board support member 5c from the vertical direction. In addition, the circuit board B remains sandwiched by the slave clamp 2a and the reference clamp 2b from the front-rear direction. By this step, a pair of front and rear non-pressure contact areas A is again defined between the circuit board B and the screen mask 420c. In the non-pressure contact area A, a gap is formed between the screen mask 420c and the circuit board B.

  Next, the insertion process will be described. In FIG. 12, the schematic diagram of the 1st step of the insertion process of the screen printing method of this embodiment is shown. FIG. 13 shows a schematic diagram of the peeling process, which is the second stage of the insertion process. As shown in FIGS. 12 and 13, in this step, the substrate pressing member 5a is driven by the substrate pressing member cylinder device 41a. And the nail | claw part 51a of the board | substrate pressing member 5a is inserted in the back non-pressure-contact area | region A. FIG. The front edge of the claw portion 51a is inserted up to a position reaching the upper rear edge of the circuit board B. Similarly, the substrate pressing member 5b is driven by the substrate pressing member cylinder device 41b. Then, the claw portion 51b of the substrate pressing member 5b is inserted into the front non-pressure contact area A. The rear edge of the claw portion 51b is inserted to a position that reaches the upper front edge of the circuit board B. The circuit board B is sandwiched from above and below by the claw portions 51a and 51b and the board support member 5c.

  Next, the peeling process will be described. As shown in FIG. 13, in this step, the pressing plate cylinder devices 440a and 440b are driven to raise the pressing plates 441a and 441b. Then, the screen mask 420c is peeled from the circuit board B. At this time, the pressing plates 441a and 441b are raised at a predetermined speed. For this reason, the screen mask 420c can be separated from the circuit board B at a predetermined speed.

  After the pressing plates 441a and 441b and the screen mask 420c are lifted, the air in the side clamp cylinder device 40 leaks. And the clamping force from the circuit board B front-back direction by the subordinate clamp 2a and the reference | standard clamp 2b is removed (refer above-mentioned FIG. 7). Subsequently, the substrate support member 5c is lowered with respect to the claw portions 51a and 51b. At the same time, the slave clamp 2a and the reference clamp 2b are lowered (see FIG. 6). Then, the substrate pressing member 5a is retracted by the substrate pressing member cylinder device 41a, and the substrate pressing member 5b is retracted by the substrate pressing member cylinder device 41b (see FIGS. 5 and 4). Thereafter, the circuit board B is carried out by the pair of belt conveyors 7a and 7b, electronic components are mounted, and reflow soldering is performed.

[Function and effect]
Next, functions and effects of the screen printing method and the screen printer 1 according to the present embodiment will be described. According to the screen printing method and the screen printing machine 1 of the present embodiment, when the circuit board B is transported to the printing position H1, the circuit board B can be firmly held by the board holding device 5. When the cream solder is printed on the circuit board B, the board pressing members 5a and 5b of the board holding device 5 can be removed from above the circuit board B.

  Further, according to the screen printing method and the screen printer 1 of the present embodiment, as shown in FIG. 7, the circuit board B can be sandwiched from above and below by the substrate sandwiching device 5 in the sandwiching step. For this reason, even the circuit board B with a thin plate thickness can be reliably held.

  Further, according to the screen printing method and the screen printer 1 of the present embodiment, as shown in FIG. 10, the screen mask 420c is substantially flat in the horizontal direction between the pair of frames 420a and 420b at the printing position H1. It is set to become a shape. For this reason, as shown in FIG. 11, the state where the upper surface of the circuit board B and the lower surface of the screen mask 420c are kept in close contact with each other even if the pressing force of the pressing plates 441a and 441b is removed. Therefore, cream solder can be printed on the circuit board B in a state where the upper surface of the circuit board B and the lower surface of the screen mask 420c are in close contact with each other during printing. That is, the gap C0 as shown in FIG. 29 does not occur between the upper surface of the circuit board B and the lower surface of the screen mask 420c. For this reason, the screen printing method and the screen printing machine 1 of this embodiment have high printing accuracy. In addition, there is little risk of “bleeding” in the solder printed portion of the circuit board B.

  Further, according to the screen printing method and the screen printing machine 1 of the present embodiment, as shown in FIG. 8, the substrate pressing members 5a and 5b are extracted in the extraction step while maintaining the pressure contact state created in the pressure contact step. Yes. That is, the substrate pressing members 5a and 5b are extracted in a state where the pressure contact force is constantly applied to the circuit substrate B. For this reason, even if the board | substrate holding | suppressing members 5a and 5b are extracted, there is little possibility that the circuit board B will bend. Also in this point, the screen printing method and the screen printing machine 1 of this embodiment have high printing accuracy. In addition, there is little risk of “bleeding” in the solder printed portion of the circuit board B.

  Further, according to the screen printing method and the screen printing machine 1 of the present embodiment, as shown in FIG. 12, the circuit board B and the screen mask 420c are inserted in the insertion step while maintaining the pressure contact state created in the re-pressure contact step. The substrate pressing members 5a and 5b are inserted between them. Then, as shown in FIG. 13, the screen mask 420c is peeled from the circuit board B from this state in the peeling step. The board pressing members 5a and 5b hold the upper surface of the circuit board B, not the narrow side surface. For this reason, the screen printing method and the screen printing machine 1 of this embodiment have high operational reliability when the screen mask 420c is peeled from the circuit board B.

  The board pressing members 5a and 5b hold the circuit board B from above. On the other hand, the separation direction of the screen mask 420c is also upward. That is, the press-contact direction of the substrate pressing members 5a and 5b and the peeling direction are parallel. For this reason, there is little possibility that the circuit board B and the board pressing members 5a and 5b are disengaged in the peeling process. Also in this respect, the screen printing method and the screen printing machine 1 of the present embodiment have high operational reliability when the screen mask 420c is peeled from the circuit board B.

  Further, if the substrate pressing members 5a and 5b are inserted between the circuit board B and the screen mask 420c while maintaining the pressure contact state, it is possible to prevent the circuit board B from being peeled off from the screen mask 420c at a stretch. Therefore, according to the screen printing method and the screen printer 1 of the present embodiment, the printing accuracy is increased. In addition, the possibility of “smearing” in the solder printed portion of the circuit board B is reduced.

  Further, according to the screen printing method and the screen printing machine 1 of the present embodiment, as shown in FIG. 8, the non-pressure contact region A is formed between the circuit board B and the screen mask 420c in the pressure contact process. . In the non-pressure contact area A, a gap is secured between the circuit board B and the screen mask 420c. Further, the front edge of the claw portion 51a and the rear edge of the claw portion 51b are disposed in the non-pressure contact region A. For this reason, in the extraction process, the substrate pressing members 5a and 5b can be extracted more reliably.

  Further, according to the screen printing method and the screen printing machine 1 of the present embodiment, the non-pressure contact area A is formed between the circuit board B and the screen mask 420c in the re-pressure contact process. In the non-pressure contact area A, a gap is secured between the circuit board B and the screen mask 420c. For this reason, as shown in FIG. 12, it is easy to insert the substrate pressing members 5a and 5b in the insertion process.

<Second embodiment>
A difference between the screen printing method and the screen printing machine of the present embodiment and the screen printing method and the screen printing machine of the first embodiment is that a suction device is arranged instead of the pressing device. In addition, the board pressing member clamps and releases the circuit board by a rotational movement. Therefore, the differences will be mainly described here.

[Configuration of screen printer]
First, the configuration of the screen printing machine of this embodiment will be described. FIG. 14 shows a side view of the screen printing machine of this embodiment. In addition, about the site | part corresponding to previous FIG. 1, it shows with the same code | symbol. FIG. 15 is a perspective view of the upper part of the movable portion 8 of the screen printing machine 1 of the present embodiment. In addition, about the site | part corresponding to previous FIG. 2, it shows with the same code | symbol. FIG. 16 shows an enlarged view in a circle XVI in FIG. FIG. 17 shows a state where the substrate pressing member of FIG. 16 is rotated. As shown in FIGS. 14, 15, 16, and 17, the screen printing machine 1 according to the present embodiment includes a movable part 8, a support part 9, and a printing part 10.

  The substrate clamping device 5 of the movable part 8 includes substrate pressing members 5d and 5e. The substrate pressing member 5d is disposed on the upper edge of the dependent clamp 2a of the side clamp device 2. A plurality of substrate pressing members 5d are arranged along the longitudinal direction (left-right direction) of the subordinate clamp 2a. The substrate pressing member 5d includes a shaft portion 50d and a claw body 51d.

  The substrate pressing member 5d can be switched between a sandwiched state shown in FIG. 16 and a released state shown in FIG. The released state is a state in which the substrate pressing member 5d is rotated 180 ° with respect to the sandwiched state. Hereinafter, the substrate pressing member 5d will be described with reference to the clamping state shown in FIG.

  The shaft portion 50d has a short-axis prism shape extending in the left-right direction. The shaft portion 50d is accommodated in a notch 20a formed on the upper surface of the dependent clamp 2a. The lower surface of the shaft portion 50d in the sandwiched state has a curved surface shape. From both the left and right sides of the shaft portion 50d, convex portions 500d are projected. The convex portion 500d has a short-axis cylindrical shape. Each of the pair of convex portions 500d is rotatably accommodated by concave portions (not shown) provided in the left and right walls of the cutout portion 20a. The substrate pressing member 5d is rotationally driven by a stepping motor (not shown).

  The claw body 51d has an arc plate shape. That is, the upper surface of the claw body 51d has a curved surface shape with a small curvature. On the other hand, the lower surface of the claw body 51d has a planar shape. The claw body 51d protrudes forward from the upper surface of the shaft portion 50d. The front edge of the claw body 51d protrudes forward from the front edge of the dependent clamp 2a. In the released state shown in FIG. 17, the rear edge of the claw body 51d protrudes rearward from the rear edge of the dependent clamp 2a.

  A suction hole 450a is opened on the upper surface of the dependent clamp 2a. The suction hole 450a is connected to a vacuum pump (not shown). A plurality of suction holes 450a are arranged along the longitudinal direction of the dependent clamp 2a. The plurality of suction holes 450a and the plurality of substrate pressing members 5d are alternately arranged along the longitudinal direction of the dependent clamp 2a.

  The substrate pressing member 5e and the suction hole 450b are disposed on the upper edge of the reference clamp 2b of the side clamp device 2. The configurations of the substrate pressing member 5e and the suction hole 450b are the same as the configurations of the substrate pressing member 5d and the suction hole 450a. That is, the substrate pressing member 5e includes a shaft portion and a claw body 51e. The suction hole 450b is connected to a vacuum pump. The arrangement of the substrate pressing member 5e and the suction hole 450b is bilaterally symmetric with the arrangement of the substrate pressing member 5d and the suction hole 450a. Further, the rotation direction of the substrate pressing member 5e when switching between the sandwiched state and the released state is bilaterally symmetric with the rotation direction of the substrate pressing member 5d. The substrate pressing member 5e is rotationally driven by a stepping motor (not shown) in the same manner as the substrate pressing member 5d. The suction device 45 of the present embodiment includes the suction hole 450a of the slave clamp 2a and the suction hole 450b of the reference clamp 2b.

[Screen printing method]
Next, the screen printing method of this embodiment will be described. The screen printing method of the present embodiment includes a clamping process, a press-contacting process, a drawing-out process, a press-contact releasing process, a printing process, a re-pressing process, an inserting process, and a peeling process.

  First, the clamping process will be described. In FIG. 18, the schematic diagram of the 1st step of the clamping process of the screen printing method of this embodiment is shown. FIG. 19 shows a schematic diagram of the second stage of the process. FIG. 20 shows a schematic diagram of the third stage of the process and the first stage of the pressure welding process.

  In this step, first, the circuit board B is placed on a pair of belt conveyors 7a and 7b from a stocker (not shown) as shown in FIG. Next, the pair of belt conveyors 7a and 7b are driven to convey the circuit board B to a predetermined position (just below a printing position described later). During transport, the front-rear direction interval between the sub-clamp 2a and the reference clamp 2b is smaller than the front-rear direction width of the circuit board B in order to suppress interference between the circuit board B, the sub-clamp 2a, and the reference clamp 2b. It is set slightly larger. Further, the substrate pressing members 5d and 5e are in a sandwiched state.

  Next, as shown in FIG. 18, the ball screw 30 is rotated and the nut portion 31 is moved forward. A slave clamp 2 a is connected to the nut portion 31 via a side clamp cylinder device 40. For this reason, the dependent clamp 2a also moves forward together with the nut portion 31. When the slave clamp 2a moves, the distance between the slave clamp 2a and the reference clamp 2b is reduced. For this reason, the circuit board B is pushed forward by the subordinate clamp 2a and moves forward, and is sandwiched between the subordinate clamp 2a and the reference clamp 2b. After clamping, the air of the side clamp cylinder device 40 is leaked, and the clamping force to the circuit board B is removed.

  Next, as shown in FIG. 19, the 1st table 60 is raised and the board | substrate support member 5c is raised. In addition, the second table 61 shown in FIG. 14 is raised. Then, as shown in FIG. 20, the upper surface of the rear edge of the circuit board B is abutted against the lower surface of the claw body 51d of the substrate pressing member 5d. In addition, the upper surface of the front edge of the circuit board B is abutted against the lower surface of the claw body 51e of the substrate pressing member 5e. That is, the circuit board B is sandwiched from above and below by the pair of board pressing members 5d and 5e and the board support member 5c. Then, air is supplied to the side clamp cylinder device 40, and the circuit board B is sandwiched between the slave clamp 2a and the reference clamp 2b from the front-rear direction. Thereafter, the horizontal position of the circuit board B is corrected. That is, an error in the horizontal direction of the circuit board B with respect to a printing position to be described later is corrected.

  Next, the pressure contact process will be described. FIG. 21 shows a schematic diagram of the second stage of the press-contact process of the screen printing method of the present embodiment and the first stage of the extraction process. As shown in FIG. 20, in this step, the circuit board B is further raised to the printing position H1. The circuit board B remains sandwiched by the substrate clamping device 5 from the vertical direction and from the subordinate clamp 2a and the reference clamp 2b from the front-rear direction.

  As shown in FIG. 21, the circuit board B raised to the printing position H1 contacts the screen mask 420c. In this state, by driving the vacuum pump, the screen mask 420c is attracted to the suction holes 450a and 450b. Then, the lower surface of the screen mask 420c is brought into pressure contact with the upper surface of the circuit board B.

  FIG. 22 is an enlarged cross-sectional view of the vicinity of the rear edge of the circuit board B in the second stage of the press-contact process of the screen printing method of the present embodiment and in the first stage of the extraction process. As shown in FIG. 22, a nail body 51d is interposed between the circuit board B and the screen mask 420c. In addition, the suction hole 450a is not disposed in the claw body 51d disposed portion of the dependent clamp 2a (see FIG. 15 above). For this reason, the negative pressure of the suction hole 450a does not occur in the nail body 51d arrangement site. Therefore, the nail body 51d intervening portion between the circuit board B and the screen mask 420c corresponds to the non-pressure contact region A. The non-pressure contact areas A are dotted at predetermined intervals in the left-right direction (interval between a pair of adjacent nail main bodies 51d).

  Similarly, the suction hole 450b is not disposed in the portion of the reference clamp 2b where the claw body 51e is disposed (see FIG. 15 above). For this reason, the negative pressure of the suction hole 450b does not occur at the nail body 51e arrangement site. Therefore, the nail body 51e intervening portion between the circuit board B and the screen mask 420c corresponds to a non-pressure contact region. The non-pressure contact regions are scattered at a predetermined interval in the left-right direction (interval between a pair of adjacent nail main bodies 51e).

  Next, the extraction process will be described. FIG. 23 shows a schematic diagram of the second stage of the drawing process of the screen printing method of the present embodiment, the pressure contact releasing process, and the printing process. As shown in FIG. 21, in this step, the substrate holding members 5d and 5e in the sandwiched state are switched to the released state. Specifically, the nail body 51d is rotated 180 ° backward about the shaft portion 50d while negative pressure is applied to the screen mask 420c from the suction holes 450a and 450b. In addition, the claw body 51e is rotated forward 180 ° around the shaft portion 50e.

  Next, the pressure contact releasing process will be described. As shown in FIG. 23, the vacuum pump is stopped in this step. Then, supply of negative pressure from the suction holes 450a and 450b to the screen mask 420c is stopped. For this reason, the circuit board B and the screen mask 420c are in close contact, but are not in pressure contact.

  Next, the printing process will be described. As shown in FIG. 23, in this step, the squeegee cylinder device 432 is driven and the squeegee body 433 is lowered. Then, the squeegee body 433 is brought into contact with the screen mask 420c. Then, the squeegee cylinder device 432, that is, the squeegee main body 433 is moved along the guide member 434. And cream solder is apply | coated to the predetermined position of the circuit board B through the printing hole (not shown) of the screen mask 420c.

  Next, the re-pressure contact process will be described. FIG. 24 is a schematic diagram of the first stage of the insertion process, which is the re-pressing process of the screen printing method of the present embodiment. As shown in FIG. 24, in this step, the screen mask 420c is adsorbed to the suction holes 450a and 450b by driving the vacuum pump. Then, the lower surface of the screen mask 420c is brought into pressure contact with the upper surface of the circuit board B. By this step, similarly to the above-described pressure contact step, non-pressure contact regions are formed at predetermined intervals along the longitudinal direction of the subordinate clamps 2a and 2b (see FIG. 22 above).

  Next, the insertion process will be described. FIG. 25 is a schematic diagram of the peeling process, which is the second stage of the insertion process of the screen printing method of the present embodiment. As shown in FIGS. 24 and 25, in this step, the substrate holding members 5d and 5e in the released state are switched to the sandwiched state. Specifically, the nail body 51d is rotated forward 180 ° about the shaft portion 50d while negative pressure is applied to the screen mask 420c from the suction holes 450a and 450b. The nail body 51d is inserted into the non-pressure contact area. In addition, the claw body 51e is rotated 180 ° backward about the shaft portion 50e. The nail body 51e is inserted into the non-pressure contact area. Then, the circuit board B is sandwiched between the claw bodies 51d and 51e and the board support member 5c from the vertical direction.

  Next, the peeling process will be described. As shown in FIG. 25, the vacuum pump is stopped in this step. Then, supply of negative pressure from the suction holes 450a and 450b to the screen mask 420c is stopped. Then, the air of the side clamp cylinder device 40 is leaked, and the clamping force from the front and rear direction of the circuit board B by the subordinate clamp 2a and the reference clamp 2b is removed. Subsequently, the substrate support member 5c is lowered with respect to the claw bodies 51d and 51e. In addition, the slave clamp 2a and the reference clamp 2b are lowered. Thereafter, as shown in FIG. 18, the circuit board B is unloaded by a pair of belt conveyors 7a and 7b, mounted with electronic components, and reflow soldered.

[Function and effect]
Next, functions and effects of the screen printing method and the screen printer 1 according to the present embodiment will be described. The screen printing method and the screen printing machine 1 according to the present embodiment have the same operational effects as the screen printing method and the screen printing machine according to the first embodiment with respect to the parts having the same configuration.

  Further, according to the screen printing method and the screen printing machine 1 of the present embodiment, the circuit board B and the screen mask 420c can be brought into pressure contact by the negative pressure of the suction device 45. For this reason, there is little possibility of damaging the circuit board B and the screen mask 420c. Further, the suction holes 450 a and 450 b are incorporated in the side clamp device 2. For this reason, the structure of the printing unit 10 is simplified.

  Moreover, according to the screen printer 1 of this embodiment, the board | substrate holding | suppressing members 5d and 5e which rotate rather than reciprocate to the front-back direction are arrange | positioned. For this reason, the length of the screen printing machine 1 in the front-rear direction can be reduced.

  Further, according to the screen printing machine 1 of the present embodiment, as shown in FIG. 17, the shaft portion 50d does not protrude upward from the cutout portion 20a in the released state. For this reason, in the printing process, the circuit board B and the screen mask 420c are more easily brought into close contact with each other. Therefore, the screen printing machine of this embodiment has high printing accuracy. In addition, there is little risk of “bleeding” in the solder printed portion of the circuit board B.

<Third embodiment>
The difference between the screen printing method and screen printing machine of the present embodiment and the screen printing method and screen printing machine of the second embodiment is only the shape of the nail body of the substrate pressing member. Therefore, the differences will be mainly described here.

  FIG. 26 is an enlarged schematic view of the vicinity of the substrate pressing member of the screen printing machine according to the present embodiment. In addition, about the site | part corresponding to FIG. 18, it shows with the same code | symbol. FIG. 26 shows only the rear substrate pressing member 5d of the pair of substrate pressing members 5d and 5e (see FIG. 18). The shape of the front substrate pressing member 5e is the same as the shape of the rear substrate pressing member 5d. The following description also serves as an explanation for the front substrate pressing member 5e.

  In FIG. 26, the shape of the nail | claw main body of 2nd embodiment is shown with a dashed-dotted line. As shown in FIG. 26, the claw body 51d of the substrate pressing member 5d of this embodiment has a larger curvature of the leading edge portion X1 than the claw body of the second embodiment. In addition, the front end X2 is rounded in a chamfered shape.

  The screen printing method and the screen printer according to the present embodiment have the same functions and effects as those of the screen printing method and the screen printer according to the second embodiment with respect to parts having the same configuration.

  Further, according to the screen printing method and the screen printing machine of the present embodiment, the front edge portion X1 of the nail body 51d is smaller than that of the second embodiment. The front end X2 is rounded. For this reason, when rotating, there is little possibility that the nail body 51d will scrape the lower surface of the screen mask.

<Others>
The embodiments of the screen printing method and the screen printing machine according to the present invention have been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  For example, the fluid used for various cylinder devices is not particularly limited. Gases other than air, liquids such as water and oil, and the like can be used. Moreover, you may arrange | position a rod-shaped press member instead of the press plates 441a and 441b of 1st embodiment. In this case, a large number of pressing members may be arranged at predetermined intervals in the left-right direction. Moreover, you may rotate the some board | substrate holding | suppressing member 5d of 2nd embodiment and 3rd embodiment by the common rotating shaft extended in the left-right direction. Similarly, the plurality of substrate pressing members 5e may be rotated by a common rotating shaft extending in the left-right direction. This makes it easy to align the operations of the plurality of substrate pressing members 5d or the plurality of substrate pressing members 5e when switching between the sandwiched state and the released state. Further, the drive mechanism for the substrate pressing members 5d and 5e is not particularly limited. In addition to the stepping motor, the substrate pressing members 5d and 5e may be driven by, for example, a cylinder device. In addition, the screen mask 420c may be pressed against the circuit board B by using the pressing device 44 of the first embodiment together with the suction device 45 of the second embodiment and the third embodiment.

It is a side view of the screen printer of a first embodiment. It is a perspective view of the upper part of the movable part of the screen printing machine. It is a disassembled perspective view of the upper part of the movable part of the screen printing machine. It is a schematic diagram of the 1st step of the clamping process of the screen printing method of 1st embodiment. It is a schematic diagram of the 2nd step of the process. It is a schematic diagram of the 3rd step of the process. It is a schematic diagram of the 4th stage of the process and the 1st stage of a press-contact process. It is a 2nd step of the press-contact process of the screen printing method of 1st embodiment, and is a schematic diagram of the 1st step of an extraction process. It is a 2nd step of the extraction process of the same screen printing method, and is a schematic diagram of the 1st step of a pressure release process. It is a schematic diagram of the 2nd step of the press-contact cancellation | release process of the screen printing method. It is a 3rd step of the process, and is a schematic diagram of a printing process. It is a schematic diagram of the 1st step of the insertion process of the screen printing method. It is a 2nd step of the same insertion process, and is a schematic diagram of a peeling process. It is a side view of the screen printer of a second embodiment. It is a perspective view of the upper part of the movable part of the screen printing machine. FIG. 16 is an enlarged view in a circle XVI in FIG. 15 (clamping state). It is an enlarged view of the state which the board | substrate pressing member of FIG. 16 rotated (release state). It is a schematic diagram of the 1st step of the clamping process of the screen printing method of 2nd embodiment. It is a schematic diagram of the 2nd step of the process. It is a schematic diagram of the 3rd step of the process and the 1st step of a press-contact process. It is a schematic diagram of the 2nd step of the press-contact process of the screen printing method, and the 1st step of an extraction process. It is a 2nd step of the press-contact process of the screen printing method, and is an expanded sectional view of the circuit board rear edge vicinity in the 1st step of the extraction process. It is a schematic diagram of the 2nd step of the extraction process of the same screen printing method, a press-contact cancellation | release process, and a printing process. It is a re-pressure-welding process of the screen printing method, and is a schematic diagram of the first stage of the insertion process. It is a 2nd step of the insertion process of the screen printing method, and is a schematic diagram of a peeling process. It is an expansion schematic diagram near the board | substrate pressing member of the screen printer of 3rd embodiment. It is the schematic diagram before the circuit board clamping of the conventional screen printer. It is a schematic diagram in the middle of the circuit board clamping of the screen printing machine. It is a schematic diagram in the middle of printing of the screen printing machine.

Explanation of symbols

1: Screen printer.
2: side clamp device, 2a: slave clamp, 2b: reference clamp, 20a: notch.
3: positioning device, 30: ball screw, 31: nut portion, 310: nut body, 311: bracket.
40: side clamping cylinder device, 41a: substrate pressing member cylinder device, 41b: substrate pressing member cylinder device, 42: screen device, 43: squeegee device, 44: pressing device, 45: suction device, 400: cylinder body 401: piston rod, 410a: cylinder body, 410b: cylinder body, 411a: piston rod, 411b: piston rod, 412a: bracket, 412b: bracket, 420a: frame, 420b: frame, 420c: screen mask, 432: squeegee Cylinder device, 433: squeegee body, 434: guide member, 440a: pressure plate cylinder device, 440b: pressure plate cylinder device, 441a: pressure plate, 441b: pressure plate, 450a: suction hole, 450b: suction hole.
5: Substrate clamping device, 5a: Substrate pressing member, 5b: Substrate pressing member, 5c: Substrate holding member, 5d: Substrate pressing member, 50a: Base, 50b: Base, 50d: Shaft, 50e : Shaft part, 51a: Claw part, 51b: Claw part, 51d: Claw body, 51e: Claw body, 500d: Convex part.
60: First table, 61: Second table, 62: Third table, 601: Elevating member, 602: Nut, 604: Motor, 605: Guide rod, 610: Roller, 620: Ball bearing, 621: For cam Guide rail, 622: cam member, 623: member guide rail.
7: conveyor device, 7a: belt conveyor, 7b: belt conveyor, 70a: belt, 70b: belt.
8: Movable part.
9: support portion, 90: lifting table, 91: support, 92: lifting device, 900: flat frame portion, 901: guided column, 902: guided recess, 903: nut portion, 910: guide rail, 920: motor .
10: Print section.
A: Non-pressure contact area, B: Circuit board, H1: Printing position, X1: Front edge portion, X2: Front edge.

Claims (9)

A sandwiching step of sandwiching a circuit board before printing from above and below by a substrate sandwiching device having a substrate pressing member and a substrate support member;
A pressure-contacting process in which the sandwiched circuit board and a screen mask disposed above the circuit board are pressed from above and below to be in a pressure-contact state;
An extraction step of extracting the substrate pressing member from between the circuit board in the pressure contact state and the screen mask;
A pressure-contact releasing step for releasing the pressure-contact state while keeping the circuit board and the screen mask in close contact with each other;
A printing step of printing cream solder on the circuit board through the screen mask;
A screen printing method comprising: Furthermore, a re-pressing step in which the printed circuit board and the screen mask are pressed against each other again from above and below to be in the pressed state,
An insertion step of inserting the substrate pressing member between the circuit board in the pressure contact state and the screen mask;
A peeling step of peeling the screen mask from the circuit board;
The screen printing method according to claim 1, comprising: In the pressure contact step, a non-pressure contact region where the circuit board and the screen mask are not pressure-contacted is formed between the circuit board and the screen mask,
3. The screen printing method according to claim 1, wherein in the extracting step, the substrate pressing member is extracted from the non-pressure contact region. In the re-pressure contact process, a non-pressure contact region where the circuit board and the screen mask are not pressed together is formed between the circuit board and the screen mask.
4. The screen printing method according to claim 2, wherein in the inserting step, the substrate pressing member is inserted into the non-pressure contact region.   5. The screen printing method according to claim 1, wherein the press-contact state is formed by a pressing device that presses the screen mask against the circuit board.   5. The screen printing method according to claim 1, wherein the pressure contact state is formed by a suction device that attracts the screen mask to the circuit board. A board holding device having a board pressing member and a board supporting member, and capable of holding the circuit board from above and below;
A screen mask disposed above the circuit board;
A pressure-contacting device capable of pressure-contacting the screen mask to the circuit board;
A screen printing machine comprising:
In a printing position where cream solder is printed on the circuit board via the screen mask, the screen mask is set to be substantially planar in the horizontal direction,
Before printing, the lower surface of the screen mask is brought into pressure contact with the upper surface of the circuit board held by the substrate holding device by the pressing force supplied by the pressure welding device, and the substrate holding member of the substrate holding device is held in the state as it is. Removing from the top surface of the circuit board;
A screen printing machine characterized in that the upper surface of the circuit board and the lower surface of the screen mask are kept in close contact with each other by removing the pressure contact force from the screen mask at the printing position.   The screen printing machine according to claim 7, wherein the pressure welding device is a pressing device that presses the screen mask against the circuit board.   The screen printing machine according to claim 7, wherein the pressure contact device is a suction device that attracts the screen mask to the circuit board.

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