JP7365650B2 - screen printing machine - Google Patents

Description

The present disclosure relates to a screen printing machine that prints paste such as solder on a substrate by sliding a print head over a stencil sheet.

Conventionally, there is a screen printing machine that screen prints a conductive paste such as solder on the electrodes of a substrate. A stencil (mask) is brought into contact with the substrate, and a squeegee of a print head is slid over the stencil, thereby transferring the paste supplied on the stencil to the substrate. A stencil consists of a stencil sheet (mask body) provided with patterned holes corresponding to electrodes on a substrate, and a stencil frame (mask frame) that supports the periphery of the stencil sheet.

For example, Patent Document 1 describes a stencil that includes a stencil frame that further attaches a sheet-like member made of resin to the outer edge of the stencil sheet and supports the outer edge of the sheet-like member. The operator attaches the stencil frame to the stencil holder and performs screen printing.

Further, Patent Document 2 describes a screen printing machine in which an operator attaches a stencil sheet to a stencil holder.

JP2013-159022A Japanese Patent Application Publication No. 2013-111847

Screen printing machines use a stencil sheet that matches the substrate to be printed, and it is necessary to replace the stencil sheet each time the model of the substrate to be printed changes. As shown in Patent Document 1, in conventional screen printing machines, the operator replaces the stencil by attaching and detaching the stencil frame to the stencil holder, which places a heavy workload on the operator. Patent Document 2 discloses a screen printing machine in which a frameless stencil sheet can be attached and detached, but the stencil sheet had to be replaced by an operator.

Therefore, an object of the present disclosure is to provide a screen printing machine that can automatically replace the stencil sheet in order to solve the above-mentioned conventional problems.

The screen printing machine of the present disclosure includes:
a magazine that stores a stencil sheet having openings corresponding to the electrodes on the substrate;
a sheet holder that removably holds the edge of the stencil sheet;
a conveyance device that conveys the stencil sheet between the magazine and the sheet holder;
a print head that fills the opening with paste placed on the stencil sheet held by the sheet holder;
Equipped with.

According to the present disclosure, it is possible to provide a screen printing machine that can automatically replace a stencil sheet.

A plan view of essential parts of a screen printing machine according to an embodiment of the present disclosure A perspective view of main parts of a screen printing machine according to an embodiment of the present disclosure A side view of main parts of a screen printing machine according to an embodiment of the present disclosure Top view of stencil sheet Perspective view of moving body Perspective view from below of the stencil holder (a) is a plan view of the stencil holder, and (b) is a side view of the connecting member. Explanatory diagram explaining the pneumatic control system Explanatory diagram explaining the conveyance of the stencil sheet Explanatory diagram explaining the conveyance of the stencil sheet Explanatory diagram explaining the conveyance of the stencil sheet Explanatory diagram explaining the procedure for conveying the stencil sheet Explanatory diagram explaining the procedure for conveying the stencil sheet Explanatory diagram explaining the procedure for conveying the stencil sheet Explanatory diagram explaining the procedure for conveying the stencil sheet Explanatory diagram explaining the procedure for conveying the stencil sheet Explanatory diagram explaining the procedure for conveying the stencil sheet Explanatory diagram explaining the procedure for conveying the stencil sheet Plan view of the stencil sheet being conveyed to the attachment/detachment position Pa Explanatory diagram explaining the procedure for attaching the stencil sheet to the sheet holder Explanatory diagram explaining the procedure for attaching the stencil sheet to the sheet holder Explanatory diagram explaining the procedure for attaching the stencil sheet to the sheet holder Explanatory diagram explaining the procedure for attaching the stencil sheet to the sheet holder Explanatory diagram explaining the operation of screen printing work Explanatory diagram explaining the operation of screen printing work Explanatory diagram explaining the operation of screen printing work Front view of magazine Top view of the magazine with the top wall removed FIG. 18(a) is a perspective view of the main parts inside the magazine, and FIG. 18(b) is a side view of the magazine as seen from a longitudinal section. Perspective view of the front main parts inside the magazine

According to a first aspect of the present disclosure, there is provided a magazine that stores a stencil sheet having an opening corresponding to an electrode on a substrate, a sheet holder that removably holds an edge of the stencil sheet, and the magazine and the sheet holder. A screen printing machine is provided, which includes a conveyance device that conveys the stencil sheet between the spaces, and a print head that fills the opening with paste placed on the stencil sheet held by the sheet holder.

According to a second aspect of the present disclosure, the conveyance device conveys the stencil sheet below the sheet holder, and the sheet holder attaches and detaches the stencil sheet to a lower part of the sheet holder. Provides a screen printing machine as described in.

According to a third aspect of the present disclosure, there is provided the screen printing machine according to the first aspect or the second aspect, wherein the sheet holder clamps the stencil sheet by applying tension in a surface direction.

According to a fourth aspect of the present disclosure, the screen printing according to the second or third aspect includes a lift that moves the sheet holder to a lower clamp position for clamping the stencil sheet and an upper standby position. provide a machine.

According to a fifth aspect of the present disclosure, the stencil sheet has a plurality of holes formed along an outer edge, the sheet holder includes a plurality of protrusions projecting downward, and the stencil sheet The screen printing machine according to the fourth aspect is provided, wherein the plurality of protrusions are inserted into the plurality of holes of the stencil sheet by moving the holder to the clamping position.

According to a sixth aspect of the present disclosure, the sheet holder includes an actuator that applies tension to the stencil sheet by moving the plurality of protrusions outward in a surface direction. The screen printing machine described above is provided.

According to a seventh aspect of the present disclosure, there is provided the screen printing machine according to the sixth aspect, wherein the actuator is an air cylinder operated by pneumatic pressure.

According to the eighth aspect of the present disclosure, the actuator is a first air cylinder that moves the projections inserted into the holes formed in the parallel outer edges of the stencil sheet outward in the surface direction. and a second air cylinder that moves a protrusion inserted into a hole formed in another set of outer edges outward in a plane direction perpendicular to the direction of movement by the first air cylinder; There is provided a screen printing machine according to the sixth aspect, comprising:

According to a ninth aspect of the present disclosure, the eighth aspect includes a seat holder drive unit that separately adjusts the air pressure supplied to the first air cylinder and the air pressure supplied to the second air cylinder. The screen printing machine described above is provided.

According to a tenth aspect of the present disclosure, the conveyance device includes a holding part that holds the stencil sheet intersecting with the conveyance direction, and includes a moving body that conveys the stencil sheet in the conveyance direction, and a moving body that conveys the stencil sheet in the conveyance direction; Provided is a screen printing machine according to any one of the first to ninth aspects, comprising a pair of guide rails that are arranged along the conveyance direction and support the stencil sheet conveyed by the movable body from below. do.

According to an eleventh aspect of the present disclosure, there is provided the screen printing machine according to the tenth aspect, wherein the holding section has a suction section that suctions the stencil sheet.

According to the twelfth aspect of the present disclosure, the holding section holds the portion of the stencil sheet exposed between the pair of guide rails from below, and the movable body moves the holding section up and down. There is provided a screen printing machine according to the eleventh aspect, having a directional drive.

According to a thirteenth aspect of the present disclosure, the holding section has an upper surface that contacts the lower surface of the stencil sheet, and a pin that projects upward from the upper surface, and the suction section has an opening on the upper surface. There is provided a screen printing machine according to the twelfth aspect, wherein the lower surface of the stencil sheet is held by suction.

According to a fourteenth aspect of the present disclosure, in the thirteenth aspect, in the holding section, at least two suction portions are provided at intervals in the transport direction, and the pin is arranged between the two suction portions. The screen printing machine described above is provided.

According to a fifteenth aspect of the present disclosure, the guide rail according to any one of the tenth to fourteenth aspects has a relief part for avoiding interference with a projection protruding downward from the seat holder. Provides a screen printing machine as described in.

Hereinafter, exemplary embodiments of a screen printing machine according to the present disclosure will be described with reference to the accompanying drawings. The present disclosure is not limited to the specific configurations of the embodiments below, and includes configurations based on similar technical ideas.

(Embodiment)
An embodiment of the present disclosure will be described below with reference to FIGS. 1 to 4. FIG. 1 is a plan view of the main parts of a screen printing machine 1. As shown in FIG. FIG. 2 is a perspective view of the main parts of the screen printing machine 1. FIG. 3 is a side view of the main parts of the screen printing machine 1. FIG. 4 is a plan view of the stencil sheet 15. The screen printing machine 1 transports the stencil sheet 15 stored in the magazine 81 to the attachment/detachment position Pa of the sheet holder 14, and attaches the stencil sheet 15 to the sheet holder 14 at the attachment/detachment position Pa. The screen printing machine 1 further brings the stencil sheet 15 into contact with the substrate 2, and screen prints a paste such as solder on each of the many electrodes 3 provided on the substrate 2.

Hereinafter, the conveying direction of the stencil sheet 15 will be referred to as the X-axis direction (back-and-forth direction), the moving direction of the substrate 2 will be referred to as the Y-axis direction (left-right direction), and the up-down direction will be referred to as the Z-axis direction. The X-axis direction, Y-axis direction, and Z-axis direction are perpendicular to each other. The operator who operates the screen printing machine 1 is usually located on the side in which the stencil sheet 15 is pulled out from the magazine 81 (X-axis direction). The side where the magazine 81 is arranged on the opposite side is the rear side of the screen printing machine 1.

The screen printing machine 1 includes a base 10, a unit moving mechanism 12A, a substrate holding unit 12, a magazine 81, a sheet holder 14, a transport device 51, a print head 16, and a control section 19. The magazine 81 stores a plurality of sheet-shaped stencil sheets 15. The sheet holder 14 is arranged above the substrate holding unit 12. The conveyance device 51 conveys the stencil sheet 15 in a section from the magazine 81 to the attachment/detachment position Pa. The print head 16 is provided above the sheet holder 14. The control unit 19 controls the operation of each part of the screen printing machine 1 . The screen printing machine 1 also includes a substrate carrying-in conveyor 11, a substrate holding unit 12, and a substrate carrying-out conveyor 13 provided on the base 10. The screen printing machine 1 includes a cover 10a that covers the upper part of the base 10, and the main components such as the unit moving mechanism 12A, the substrate holding unit 12, the sheet holder 14, the transport device 51, and the print head 16 are covered by the cover 10a. located within an enclosed space. The control unit 19 is housed inside the base 10.

The substrate carrying-in conveyor 11 carries in the substrate 2 inputted from the outside of the screen printing machine 1 through the carrying-in port 8 of the cover 10a (arrow R1 shown in FIGS. 1, 2, and 3), and delivers it to the substrate holding unit 12. The substrate carrying-out conveyor 13 carries out the substrate 2 received from the substrate holding unit 12 to the outside of the screen printing machine 1 through the carrying-out port 9 of the cover 10a (arrow R2 shown in FIGS. 1, 2, and 3). The substrate 2 is conveyed in the order of a substrate carry-in conveyor 11, a substrate holding unit 12, and a substrate carry-out conveyor 13.

The substrate holding unit 12 includes a unit base 21 , a pair of conveyors 22 , a lower receiving part 24 , and a pair of substrate holders 25 . The unit base 21 is supported by the unit moving mechanism 12A. The unit moving mechanism 12A is an XYZθ table, which moves the substrate holding unit 12 in a horizontal plane (in the XY plane) and in the Z-axis direction, and rotates it in the θ direction (around the Z-axis). A pair of conveyors 22 are attached to the unit base 21. The lower receiving part 24 is raised and lowered by a lifting cylinder 23 provided on the unit base 21, and both ends of the substrate 2, which has been transported and positioned at a predetermined working position (the position shown in FIG. 2) by the conveyor 22, are raised upward from the conveyor 22. The substrate 2 is lifted and supported from below so as to be spaced apart. The pair of substrate holders 25 are provided to be openable and closable in the X-axis direction, and are opened and closed by an actuator (not shown). The pair of substrate holders 25 sandwich (clamp) both sides of the substrate 2 lifted and supported by the lower receiving part 24 from the X-axis direction. The lower receiving part 24 lifts the substrate 2 so that the upper surface of the substrate 2 is at the same height as the upper surface of the substrate holder 25. The lifting cylinder 23, the conveyor 22, and the substrate holder 25 operate according to commands from the control unit 19.

The stencil sheet 15 is a mask for screen printing the paste onto the electrodes of the substrate 2. The stencil sheet 15 is made of metal, for example, and is made of SUS in the first embodiment, but may be made of resin. The stencil sheet 15 has a rectangular or square shape, for example, and is stored in the magazine 81 without being held in a frame. 2 and 4, a large number of openings 15a are provided in the central region of the stencil sheet 15, corresponding to the arrangement pattern of the electrodes 3 on the substrate 2. As shown in FIGS. A plurality of holes 15b are provided along each of the four sides at the edge of the stencil sheet 15, penetrating the stencil sheet 15 in the thickness direction. Each hole 15b is formed into a long hole extending in a direction parallel to the neighboring sides. Further, 15 m of marks for alignment are formed on the stencil sheet 15.

The print head 16 prints the paste on the electrodes of the substrate 2 by moving the paste placed on the stencil sheet 15. 1 and 2, the print head 16 includes a base member 41 that moves in the X direction, two squeegee elevating sections 42, a squeegee holder 43, and two squeegees 44. The base member 41 is provided so as to be movable in the X-axis direction in an area above the stencil sheet 15 held by the sheet holder 14. The squeegee elevating section 42 is attached to the base member 41 and has its output shaft 42a protruding below the base member 41. The squeegee holder 43 is attached to the lower end of the output shaft 42a of each squeegee elevating section 42 and extends in the Y-axis direction. The squeegee 44 is a thin plate member whose upper end is held by each squeegee holder 43 and extends obliquely downward. The base member 41 is connected to a print head moving mechanism 41a. The print head moving mechanism 41a moves the base member 41 in the X direction, and operates based on a command from the control unit 19. This causes the print head 16 to move relative to the stencil sheet 15.

Transport of the substrate 2 by the conveyor 22 of the substrate holding unit 12 and positioning operation to the working position, lower receiving operation by the lower receiving part 24 for the substrate 2 located at the working position, clamping operation by the pair of substrate holders 25, and substrate holding. Movement of the unit 12 in the horizontal plane and in the vertical direction is performed according to commands from the control section 19. That is, the control unit 19 controls these to execute various operations.

The control section 19 includes an image recognition section 19a, a mechanism control section 19b, a tension control section 19c, and a storage section 19d. The control unit 19 includes, for example, a processor, an FPGA, and the like. The image recognition section 19a, the mechanism control section 19b, and the tension control section 19c may each be composed of a plurality of processors or the like, or may be composed of one processor.

The storage unit 19d stores various production data necessary for screen printing paste such as solder on the substrate 2. The storage unit 19d is a storage device including at least one of a memory, a hard disk, an SSD, etc., and stores processing programs for the image recognition unit 19a, mechanism control unit 19b, and tension control unit 19c.

The mechanism control section 19b operates the substrate holding unit 12, unit movement mechanism 12A, print head 16, conveyance device 51, magazine elevator 91, print head movement mechanism 41a, sheet holder drive section 36 (details will be described later), etc. , carry out substrate conveyance and positioning operations, printing operations, stencil sheet exchange operations, etc.

In FIG. 1, the reciprocating movement of the print head 16 in the X-axis direction is performed by the mechanism control section 19b controlling the operation of the print head movement mechanism 41a. The movement of each squeegee 44 up and down with respect to the base member 41 is performed by the mechanism control section 19b controlling the operation of the squeegee elevating section 42 corresponding to the squeegee 44 to move the squeegee holder 43 up and down.

Next, the conveying device 51 that conveys the stencil sheet 15 will be described with reference to FIGS. 1, 3, and 5. The conveyance device 51 conveys the stencil sheet 15 between the magazine 81 and the attachment/detachment position Pa where the stencil sheet 15 is attached to and detached from the sheet holder 14 . The conveyance device 51 includes a holding section 53 that conveys the stencil sheet 15 in the conveyance direction (X-axis direction) by holding it in a hole 15b formed in an edge of the stencil sheet 15 substantially perpendicular to the conveyance direction, and a holding section 53 that conveys the stencil sheet 15 in the conveyance direction (X-axis direction). A pair of guide rails 55 arranged along the direction, a Y-axis beam 59 (moving body) to which the holding section 53 is attached, and a Y-axis beam moving section 59a that drives the Y-axis beam 59 in the transport direction. Be prepared. The conveying device 51 conveys the stencil sheet 15 by sliding both sides of the stencil sheet 15 parallel to the conveying direction onto the guide rails 55 . The Y-axis beam moving section 59a includes mechanical parts such as a motor and a feed screw (not shown), and moves the Y-axis beam moving section 59a in the X-axis direction. As a result, the holding portion 53 is moved between the pair of guide rails 55 in the transport direction (X-axis direction).

The guide rail 55 is a guide member that guides the stencil sheet 15 between the magazine 81 and the attachment/detachment position Pa. The guide rail 55 has, for example, an L-shaped vertical cross section, and includes a horizontal portion 55a that supports the stencil sheet 15 from below, and a wall portion 55b that extends upward from the horizontal portion 55a. The respective tip ends of the guide rails 55 on the seat holder 14 side are connected to each other by a support plate 56. The support plate 56 supports the front edge of the stencil sheet 15 transported to the attachment/detachment position Pa.

The holding section 53 holds the stencil sheet 15 and conveys it between the magazine 81 and the attachment/detachment position Pa directly below the sheet holder 14 . The holding portion 53 has, for example, a rectangular shape in plan view. The holding portion 53 has an upper surface 53s that contacts the lower surface of the stencil sheet 15. The upper surface 53s includes a pin 58 that engages with the stencil sheet 15 and a recess 57 that serves as a suction portion that suctions the stencil sheet 15.

Specifically, as shown in FIG. 5, a set of recesses 57 are formed in the upper surface 53s of the holding part 53 as adsorption parts, which are arranged side by side at intervals in the transport direction. A pin 58 is arranged on the upper surface 53s between the respective recesses 57 arranged side by side in the conveyance direction. Therefore, recesses 57 are formed at the front and rear of the pin 58, respectively. At least two recesses 57 may be provided at positions sandwiching the pin 58, but a plurality of recesses 57 may be arranged in the holding portion 53 in a direction orthogonal to the conveying direction. For example, two recesses 57 are arranged along the side of the holding portion 53 on the magazine 81 side. A suction hole 57a is formed in the bottom surface of each recess 57. Each suction hole 57a is connected to a suction device 61, and when the suction device 61 is activated, the recess 57 attracts the stencil sheet 15 located above it. The suction device 61 is, for example, a vacuum pump or a vacuum ejector. The holding portion 53 holds the portion exposed downward from between the pair of guide rails 55 from below.

The holding part 53 is movable in the vertical direction by a holding part elevating mechanism 54a. The holding part elevating mechanism 54a is, for example, a cylinder. The holding part elevating mechanism 54a is attached to, for example, a Y-axis beam 59 that is movable along the wall part 55b of the guide rail 55. The Y-axis beam 59 moves in a space between the guide rail 55 and the substrate holding unit 12. The holding part elevating mechanism 54a is mounted on the rear side of the Y-axis beam 59. The Y-axis beam 59 is connected to a Y-axis beam moving section 59a, and is moved in the transport direction (X-axis direction) by the Y-axis beam moving section 59a. Thereby, the holding part 53 is movable in the X-axis direction together with the holding part elevating mechanism 54a.

At the front side of the Y-axis beam 59, a lower imaging camera 17a with an imaging field of view facing downward and an upper imaging camera 17b with an imaging field of view facing upward are attached. The lower imaging camera 17a and the upper imaging camera 17b are moved in the Y direction by a camera movement mechanism (not shown) built into the Y-axis beam 59. The lower imaging camera 17a images the positioning mark 2m on the substrate 2. The upper imaging camera 17b images the alignment mark 15m on the stencil sheet 15.

In FIG. 3, the movement of the lower imaging camera 17a and the upper imaging camera 17b in the horizontal plane is performed by the mechanism control section 19b controlling the operation of the Y-axis beam moving section 59a and the camera movement mechanism. The control unit 19 controls the imaging operation by the lower imaging camera 17a and the imaging operation by the upper imaging camera 17b. The image data thus obtained are each transmitted to the control section 19 and subjected to image recognition processing in the image recognition section 19a of the control section 19. As a result, the position of the stencil sheet 15 held by the sheet holder 14 is recognized, and the position of the substrate 2 held by the substrate holding unit 12 is recognized.

The sheet holder 14 connects with the transported stencil sheet 15 and holds the stencil sheet 15. The sheet holder 14 includes a holder frame 14a having a rectangular opening in the center, and a connecting member 30 connected to the outer peripheral edge of the stencil sheet 15 within the holder frame 14a.

The connecting member 30 includes two first connecting members 31 extending in the X-axis direction and connected to both edges (vertical sides of the stencil sheet 15) of the stencil sheet 15 facing each other in the Y-axis direction; The stencil sheet 15 includes two second connecting members 32 connected to both edges (horizontal sides of the stencil sheet 15) facing each other in the Y-axis direction of the stencil sheet 15. The two first connecting members 31 are movable within the seat holder 14 in a direction (X-axis direction) perpendicular to these two first connecting members 31, and the two second connecting members 32 are It is movable within the seat holder 14 in a direction perpendicular to the two connecting members 32 (Y-axis direction).

From the bottom surface of each of the connecting members 30 (the two first connecting members 31 and the two second connecting members 32), in the direction in which the holes 15b extend (the stencil sheet 15 A connecting protrusion 30a having a small dimension in the direction (direction along the side) protrudes. A hole 14b is formed in the holder frame 14a so that the protrusion 30a projects from the inside of the holder frame 14a to the outside.

The seat holder 14 is movable to two positions: an upper standby position Pw and a lower clamp position Pc. The sheet holder 14 is moved between the two positions by a lift 71 provided on the screen printing machine 1. The lifts 71 are respectively attached to the wall portions 55b of the pair of guide rails 55. The lift 71 is connected to the upper surface of the holder frame 14a of the seat holder 14. The lift 71 is, for example, an air cylinder. At the clamp position Pc, each protrusion 30a of the sheet holder 14 is inserted into each hole 15b provided at the edge of the stencil sheet 15, and further, each protrusion 30a moves outward in the surface direction of the stencil sheet 15, so that the stencil sheet 15 to the seat holder 14. At the clamp position Pc, a hole 55c is formed in the horizontal portion 55a of the guide rail 55 (see also FIG. 12C). The purpose of this hole 55c is to avoid interference between the protrusion 30a of the sheet holder 14 that has moved to the clamp position Pc and the horizontal portion 55a, and to ensure that the lower end of the protrusion 30a that has passed through the hole 15b of the stencil sheet 15 is located on the lower surface of the stencil sheet 15. It is formed for the purpose of ensuring that it protrudes downward. That is, the hole 55c serves as a relief part for avoiding interference between the guide rail 55 and the protrusion 30a projecting downward from the seat holder 14. Note that a similar relief portion is also formed in the support plate 56.

The seat holder 14 is provided with a drive cylinder 35. The drive cylinder 35 includes two first air cylinders 35a and two second air cylinders 35b. As shown in FIG. 12C, the first air cylinder 35a has a piston rod 35e extending in the Y-axis direction connected to the first connecting member 31, and by moving the piston rod back and forth, the pair of first connecting members 31 are connected. move in opposite directions in the Y-axis direction. Similarly, the second air cylinder 35b has a piston rod extending in the Y-axis direction connected to the second connecting member 32, and by moving the piston rod back and forth, the pair of second connecting members 32 are moved in opposite directions to each other in the X-axis direction. move in the direction. The sheet holder driving section 36 operates the first air cylinder 35a and the second air cylinder 35b to apply tension to the stencil sheet 15.

The screen printing machine 1 includes a sheet holder drive section 36. In FIG. 8, the seat holder drive section 36 is connected to a pipe 39 connected to an external pressure source 40. As shown in FIG. The piping 39 branches into three systems within the seat holder drive section 36. The first system piping 37 is connected to two first air cylinders 35a. The seat holder drive section 36 includes a valve 37a and a first pressure adjustment section 37b connected in series to the first system of piping 37. The second system piping 38 is connected to two second air cylinders 35b. The seat holder drive section 36 includes a valve 38a and a second pressure adjustment section 38b connected in series to the second system of piping 38. The third system piping 72 is connected to two lifts 71. The seat holder drive section 36 includes a valve 72a and a third pressure adjustment section 72b connected in series to a third system of piping 72. The valve 37a, the valve 38a, and the valve 72a are controlled by the mechanism control section 19b of the control section 19, and supply and cut off air pressure to the first air cylinder 35a, the second air cylinder 35b, and the lift 71. When the valves 37a and 38a are opened and air pressure is supplied to the first air cylinder 35a and the second air cylinder 35b, four air Tension can be applied to the stencil sheet 15 by activating the cylinders 35a and 35b, moving the opposing connecting members 30 in a direction away from each other, and pulling the entire stencil sheet 15 in the horizontal direction. Further, when the valve 72a is activated and the lift 71 is operated downward, the seat holder 14 can be moved from the standby position Pw to the clamp position Pc. Furthermore, when the valve 72a operates in the opposite direction, the seat holder 14 can be moved to the standby position Pw.

The first pressure adjustment section 37b and the second pressure adjustment section 38b individually adjust the air pressure supplied to the first air cylinder 35a and the second air cylinder 35b. That is, the seat holder driving section 36 can separately adjust the air pressure supplied to the first air cylinder and the air pressure supplied to the second air cylinder. Thereby, the tension of the stencil sheet 15 can be managed by appropriately adjusting the air pressure. Furthermore, in this embodiment, since the air pressure can be adjusted in two systems, one in the X direction and the other in the Y direction, the tension of the stencil sheet can be adjusted separately in the X direction and the Y direction. Electropneumatic regulators can be used for the first pressure adjustment section 37b and the second pressure adjustment section 38b. When an electropneumatic regulator is used, the pressure is adjusted by input from the tension control section 19c (see FIG. 3) of the control section 19. As a result, information regarding the optimal air pressure for the stencil sheets stocked in the magazine 81 is stored in the storage section 19d in advance, and when the stencil sheet is replaced, the tension control section 19c reads the corresponding data from the storage section 19d. automatically set to the first pressure adjustment section 37b and the second pressure adjustment section 38b. That is, the adjustment of the tension accompanying the replacement of the stencil sheet 15 can also be automated. In this embodiment, the first air cylinder 35a and the second air cylinder 35b are driven by separate pneumatic circuits, but they may be driven by one system.

Next, the general operation of the screen printing machine 1 will be described with reference to FIGS. 9A to 9C and 10A to 10G. 9A to 9C are schematic explanatory diagrams illustrating the process from when the stencil sheet 15 of the screen printing machine 1 is conveyed from the magazine 81 until it is attached to the sheet holder 14. As shown in FIG. 9A, the stencil sheet 15 carried out from the magazine 81 is conveyed to the attachment/detachment position Pa below the sheet holder 14, as shown in FIG. 9B. The mechanism control unit 19b drives and controls the lift 71 to move the sheet holder 14 downward toward the stencil sheet 15 located at the attachment/detachment position Pa, thereby clamping the stencil sheet 15, as shown in FIG. 9C. First, the operation of the conveyance device 51 to convey the stencil sheet 15 housed in the magazine 81 to the attachment/detachment position Pa below the sheet holder 14 will be described.

As shown in FIG. 9A, the screen printing machine 1 includes a magazine elevator 91 that adjusts the height of the magazine 81. The magazine elevator 91 moves the magazine 81 according to instructions from the control unit 19 so that the storage height of the stencil sheet 15 to be used matches the height of the upper surface of the horizontal portion 55a of the guide rail 55.

As shown in FIG. 10A, the Y-axis beam moving unit 59a directs the holding unit 53 toward the back of the magazine 81 and below the stencil sheets 15 to be conveyed between the stencil sheets 15 stored in the magazine 81. The holding part 53 is moved so that the pin 58 of the holding part 53 is located directly below the hole 15b formed along the front edge of the stencil sheet 15.

Next, as shown in FIG. 10B, the holding part elevating mechanism 54a moves the holding part 53 upward from the avoidance position to the transport position. As a result, the pin 58 of the holding portion 53 is inserted into the hole 15b formed along the front edge of the stencil sheet 15. At the same time, the suction device 61 is activated to introduce negative pressure into the recess 57 behind the pin 58 (to the right in the drawing) to suction and hold the stencil sheet 15.

Next, as shown in FIG. 10C, the Y-axis beam moving section 59a moves the holding section 53 toward the attachment/detachment position Pa below the seat holder 14. As a result, the pin 58 of the holding portion 53 hits the inner edge of the hole 15b of the stencil sheet 15, and the stencil sheet 15 is carried out from the magazine 81. The stencil sheet 15 is conveyed while sliding on the horizontal portion 55a of the guide rail 55, with opposing edges parallel to the conveyance direction being supported by the horizontal portion 55a of the guide rail 55. Further, since the recess 57 of the holding part 53 attracts the lower surface of the stencil sheet 15, the holding part 53 can stably hold the stencil sheet 15.

Note that when the conveyance stroke of the holding section 53 is short, the holding section 53 moves from the magazine 81 to the attachment/detachment position Pa below the sheet holder 14 in two steps. At an intermediate position Pm between the magazine 81 and the attachment/detachment position Pa, the holding unit 53 reinsertes the pin 58 from the front hole 15b of the stencil sheet 15 to the rear hole 15b.

As shown in FIG. 10D, the Y-axis beam moving section 59a moves the holding section 53 to the intermediate position Pm. At the intermediate position Pm, the holding part elevating mechanism 54a moves the holding part 53 downward from the transport position to the avoidance position according to instructions from the mechanism control section 19b. As a result, the pin 58 of the holding portion 53 is pulled out from the hole 15b formed along the front edge of the stencil sheet 15.

As shown in FIG. 10E, in response to an instruction from the mechanism control unit 19b, the Y-axis beam moving unit 59a moves the holding unit 53 toward the magazine 81 to open a hole formed along the rear edge of the stencil sheet 15. The holding part 53 is moved so that the pin 58 of the holding part 53 is located directly below the pin 15b.

Next, as shown in FIG. 10F, the holding part elevating mechanism 54a moves the holding part 53 upward from the avoidance position to the conveyance position according to instructions from the mechanism control section 19b. As a result, the pin 58 of the holding portion 53 is inserted into the hole 15b formed along the rear edge of the stencil sheet 15.

Next, as shown in FIGS. 10G and 11, the Y-axis beam moving section 59a moves the holding section 53 toward the attachment/detachment position Pa below the seat holder 14 in response to an instruction from the mechanism control section 19b. As a result, the pin 58 of the holding portion 53 hits the inner edge of the hole 15b formed along the rear edge of the stencil sheet 15, and conveys the stencil sheet 15 from the intermediate position Pm toward the attachment/detachment position Pa.

When the stencil sheet 15 is further conveyed forward from the intermediate position Pm, the front part of the stencil sheet 15 eventually rides on the support plate 56, and the front part of the stencil sheet 15 is supported by the support plate 56. Thereafter, the suction by the suction device 61 is stopped according to an instruction from the mechanism control section 19b, and the holding section elevating mechanism 54a moves the holding section 53 downward from the conveying position to the avoidance position, so that the holding section 53 holds the stencil sheet 15. Release. Then, the Y-axis beam moving section 59a is moved to retract the Y-axis beam 59 to a position where it will not interfere with the substrate holding unit 12, which will subsequently rise to the attachment/detachment position Pa.

As described above, the stencil sheet 15 is moved from the magazine 81 toward the attachment/detachment position Pa below the sheet holder 14. Note that the storage process of transporting and storing from the attachment/detachment position Pa to the magazine 81 is performed in a reverse process to the above-mentioned transport process. In the conveyance process and the storage process, the stencil sheet 15 and the holding part 53 are engaged at the same point, but the conveyance direction is opposite.

Next, with reference to FIGS. 12A to 12D, a schematic operation for attaching the stencil sheet 15 located at the attachment/detachment position Pa to the sheet holder 14 will be described.

FIG. 12A illustrates a state in which the stencil sheet 15 has arrived at the attachment/detachment position Pa. From this state, the mechanism control unit 19b operates the unit moving mechanism 12A to raise the substrate holding unit 12, and the substrate holder 25 rises (see arrow Z2 in FIG. 12B). As shown in FIG. 12B, the substrate holder 25 lifts a portion of the stencil sheet 15 and stops at the height at which the stencil sheet 15 is attached or removed. Thereby, the stencil sheet 15, which is bent downward, can be supported horizontally between the pair of guide rails 55.

Next, the mechanism control unit 19b sends a drive instruction to the lift 71. The lift 71 moves the seat holder 14 from the upper standby position Pw to the lower clamp position Pc (arrow Z3 in FIG. 12B). The sheet holder 14 inserts the protrusions 30a protruding from the bottom into the holes 15b of the stencil sheet 15, respectively. Thereby, the protrusion 30a of the sheet holder 14 is inserted into the hole 15b of the stencil sheet 15, as shown in FIG. 12B.

Next, the mechanism control section 19b sends a command to the seat holder driving section 36 to open the valves 37a and 38a. As a result, air at the pressure adjusted by the first pressure adjustment section 37b is supplied to the first air cylinder 35a through the piping 37 of the first system, and air at the pressure adjusted by the second pressure adjustment section 38b is supplied to the first air cylinder 35a. The air is supplied to the second air cylinder 35b through two lines of piping 38, and the first air cylinder 35a and the second air cylinder 35b drive the four connecting members 30 to move outside the seat holder 14. As the coupling member 30 moves outward, each protrusion 30a of the coupling member 30 pushes the hole 15b of the stencil sheet 15 outward (see also arrow G1 in FIG. 12C). This applies tension to the stencil sheet 15 and holds the stencil sheet 15 horizontally. In FIG. 12C, the first connecting member 31 and the protrusion 30a before movement are shown by broken lines, and after movement is shown by solid lines.

Next, the mechanism control section 19b operates the unit moving mechanism 12A to lower the substrate holding unit 12 (arrow Z4 in FIG. 12D). This completes the attachment of the stencil sheet 15 to the sheet holder 14. Note that the removal of the stencil sheet 15 from the sheet holder 14 can be achieved by performing the reverse process of the above-mentioned process. When the attachment of the stencil sheet 15 to the sheet holder 14 is completed, the upper imaging camera 17b is moved below the stencil sheet 15 as shown in FIG. 12D, and the alignment mark 15m provided on the stencil sheet 15 (see FIG. ). Then, the image is recognized by the image recognition section 19a, and the position of the stencil sheet 15 is recognized (stencil recognition). The position of the stencil sheet 15 recognized by the stencil recognition is stored in the storage unit 19d as information used when positioning the substrate 2.

Next, with reference to FIGS. 13 to 15, the operation of the screen printing machine 1 in performing screen printing work will be described. First, when the mechanism control unit 19b detects that the substrate 2 has been sent from another device on the upstream process side, it operates the substrate carry-in conveyor 11 and the conveyor 22 of the substrate holding unit 12 to carry it into the substrate holding unit 12. (See Figure 13). Next, the mechanism control section 19b operates the substrate holding unit 12 to hold the substrate 2. Specifically, the substrate 2 is held by pushing up the lower receiving part 24 with the lifting cylinder 23 to align the heights of the upper surface of the substrate 2 and the upper surface of the substrate holder 25, and driving the pair of substrate holders 25 in the closing direction. This is done by sandwiching both ends of the substrate 2 (see FIG. 14).

After holding the substrate 2, the mechanism control section 19b operates the Y-axis beam moving section 59a and the camera movement mechanism (not shown) to move the downward imaging camera 17a to the alignment mark 2m ( 2), and the lower imaging camera 17a is caused to image the mark 2m (see arrow H1 in FIG. 14). Then, the image recognition unit 19a processes the obtained image data of the mark 2m to determine the position of the mark 2m on the substrate holding unit 12, and recognizes the position of the substrate from the determined position of the mark 2m (substrate recognition). The control unit 19 calculates the horizontal movement distance and rotation angle for aligning the substrate 2 with the stencil sheet 15 from the position of the stencil sheet 15 read from the storage unit 19d and the position of the substrate 2 determined by substrate recognition. do. Based on this calculation result, the mechanism control section 19b operates the unit moving mechanism 12A to move the substrate holding unit 12 to align the substrate 2 and the stencil sheet 15.

As shown in FIG. 15, when the alignment of the stencil sheet 15 and the substrate 2 is completed, the control section 19 controls the operation of the unit moving mechanism 12A to raise the substrate holding unit 12, and the pair of substrates 2 holding the substrate 2 are moved up. By pressing the substrate holder 25 relatively against the lower surface of the stencil sheet 15 from below, the upper surfaces of the pair of substrate holders 25 and the substrate 2 are brought into contact with the lower surface of the stencil sheet 15 (see arrow Z1). As a result, the electrode 3 on the substrate 2 and the pattern opening 15a of the stencil sheet 15 are brought into alignment.

After bringing the substrate 2 into contact with the stencil sheet 15, the control section 19 performs squeezing with the squeegee 44 to transfer the paste on the stencil sheet 15 to the substrate 2.

Specifically, this squeegeeing involves lowering one of the two squeegees 44 from the print head 16 and moving the base member 41 in the Y-axis direction while keeping it in contact with the upper surface of the stencil sheet 15. It is done by letting. As a result, the squeegee 44 slides on the stencil sheet 15, and the paste on the stencil sheet 15 is pushed into the pattern opening 15a of the stencil sheet 15 by the squeegee 44, and is transferred onto the electrode 3 of the substrate 2. Note that when performing squeegeeing by moving the print head 16 from the front to the rear, the control unit 19 brings the rear squeegee 44 into contact with the stencil sheet 15, and moves the print head 16 from the rear to the front to perform squeegeeing. When performing squeegeeing, the front squeegee 44 is brought into contact with the stencil sheet 15.

After the paste is transferred to the substrate 2 by squeezing, the control section 19 operates the unit moving mechanism 12A to lower the substrate holding unit 12 and separate the substrate 2 and the pair of substrate holders 25 from the stencil sheet 15. to separate the plates. As a result, the paste remains on the electrodes 3 of the substrate 2, and the paste is printed on the substrate 2.

When the separation of the plates is completed, the control unit 19 releases the holding of the substrate 2 by the substrate holding unit 12. Specifically, the holding of the substrate 2 is released by the mechanism control section 19b opening the pair of substrate holders 25, lowering the lower receiving section 24, and placing both ends of the substrate 2 onto the pair of conveyors 22. This is done by lowering it.

After releasing the holding of the substrate 2, the mechanism control section 19b operates the unit moving mechanism 12A to move the substrate holding unit 12 in a horizontal plane, adjusts the direction of the conveyor 22, and then operates the conveyor 22 and the substrate unloading conveyor 13. Then, the substrate 2 is carried out to the outside of the screen printing machine 1.

Next, the magazine 81 that stores a plurality of stencil sheets 15 will be described with reference to FIGS. 16 to 18. FIG. 16 is a front view of the magazine, and FIG. 17 is a plan view of the magazine with the top wall removed. 18(a) is a perspective view of the main parts inside the magazine as seen from a cross section taken in the direction of arrow XIV in FIG. 16, and FIG. 18(b) is a side view of the magazine as seen from a longitudinal section. The magazine 81 includes a guide section 82 that guides the stencil sheet 15 in the loading/unloading direction, and a fixing section 83 that fixes the stencil sheet 15 to the guide section 82. The magazine 81 also includes an upper wall 81a, side walls 81b and 81c, a lower wall 81d, a back wall 81e, and a loading/unloading port 81f for loading and unloading stencil sheets. The back wall 81e is perpendicular to the direction in which the stencil sheet 15 is taken out.

The guide portion 82 includes a first guide plate 82a that is disposed on one side (left side) in a direction perpendicular to the loading/unloading direction and directly supports one edge of the opposing edges of the stencil sheet 15. Further, the guide section 82 includes a second guide plate 82b that is disposed on the other side (right side) in the direction perpendicular to the loading/unloading direction and directly supports the other side of the opposing edges of the stencil sheet 15. The first guide plate 82a and the second guide plate 82b extend along the loading/unloading direction of the stencil sheet 15. The guide portions 82, which constitute a pair of left and right guide plates with the first guide plate 82a and the second guide plate 82b, are arranged in the vertical direction in a number corresponding to the number of stencil sheets 15 stored. The first guide plate 82a and the second guide plate 82b are respectively fixed to the side walls 81b and 81c. An edge parallel to the direction in which the stencil sheet 15 inserted into the magazine 81 is taken out is placed on the guide portion 82 . A pair of shelf boards 85 extending in the loading/unloading direction are attached to each of the first guide plate 82a and the second guide plate 82b. The shelf board 85 supports the bottom surface of the stencil sheet 15.

The fixing portion 83 includes a rectangular plate portion 83a extending in the direction of taking out the stencil sheet 15, and a V-shaped bent portion 83b extending downward from the rear end of the plate portion 83a and further bent upward. . The bent portion 83b is an elastic member, for example, a plate spring. The plate portion 83a of the fixing portion 83 is attached to the side wall 81b or 81c with, for example, bolts.

When the stencil sheet 15 is carried into the magazine 81 along the guide portion 82 and the back side of the stencil sheet 15 comes into contact with the back wall 81e of the magazine 81, the stencil sheet 15 is carried in along the carrying-in/out direction of the stencil sheet 15. The bent portion 83b of the fixing portion 83 is inserted into the hole 15b formed in the fixing portion 15 by elastic force. As a result, the stencil sheet 15 is held between the bent portion 83b inserted into the hole 15b and the back wall 81e, and the stencil sheet 15 is positioned within the magazine 81. The bent portion 83b may have a shape that simply extends downward from the rear end of the plate portion 83a, other than the V-shape, as long as it is an elastic member.

Next, refer to FIG. 19. FIG. 19 is a perspective view of the main parts of the front part inside the magazine. A distal end portion 82c of the guide portion 82 on the opposite side of the back wall 81e has an inclined surface that slopes downward. Further, the tip end 85a of the shelf board 85 on the opposite side of the back wall 81e also has an inclined surface that slopes downward. Thereby, when carrying the stencil sheet 15 into the magazine 81 and when carrying it out of the magazine 81, it is possible to prevent the stencil sheet 15 from getting caught with the tip of the guide part 82 and the tip of the shelf board 85.

The magazine 81 includes a protrusion 86 along the side of the upper wall 81a of the magazine 81, and a recess 87 corresponding to the protrusion 86 along the side of the lower wall 81d of the magazine 81. Therefore, when the user inserts the projection 86 of one magazine 81 into the recess 87 of the other magazine 81, the other magazine is fixed on top of one magazine 81. In this way, since it is possible to combine and connect a plurality of magazines 81 to each other, the weight of each magazine 81 can be reduced, and the burden of transporting the magazines 81 can be reduced.

According to the screen printing machine 1 of this embodiment, there is a magazine 81 that stores a plurality of stencil sheets 15 and has an opening 15a corresponding to the electrode 3 on the substrate 2, and a sheet that removably holds the edges of the stencil sheets 15. A transport device 51 that transports the stencil sheet 15 between the holder 14, the magazine 81, and the sheet holder 14, and a print head 16 that slides the solder paste placed on the stencil sheet 15 held by the sheet holder 14. and. With this configuration, the stencil sheet 15 with no frame attached is stored in the magazine 81, so the number of magazines 81 stored can be increased and the size of the magazine 81 can be reduced. The thickness of the conventional stencil frame is about 30 mm, and the thickness of the stencil sheet 15 is about 150 μm, so this is a significant improvement. In addition, since the conveyance device 51 conveys the frameless stencil sheet 15 from the magazine 81 and the sheet holder 14 detachably holds the frameless stencil sheet 15, the effort required to replace the stencil sheet 15 is reduced and space is saved. A screen printing machine 1 can be provided.

Further, the conveying device 51 may convey the stencil sheet 15 below the sheet holder 14 , and the sheet holder 14 may attach and detach the stencil sheet 15 to the lower part of the sheet holder 14 . Conventionally, the stencil sheet was attached to the print head side of the sheet holder, but the stencil sheet 15 is conveyed below the sheet holder 14, and the attachment and detachment of the sheet holder 14 and the stencil sheet 15 is performed below the sheet holder 14. Therefore, interference with the print head above the sheet holder 14 can be avoided, making it suitable for automation of attachment and detachment.

Further, the sheet holder 14 may clamp the stencil sheet 15 by applying tension in the surface direction. According to this configuration, since tension is applied to the stencil sheet 15 in the plane direction, misalignment between the electrode 3 of the substrate 2 and the opening 15a of the stencil sheet 15 can be prevented.

Further, a lift 71 may be provided to move the sheet holder 14 between a lower clamp position Pc for clamping the stencil sheet 15 and an upper standby position Pw. Since the sheet holder 14 can be moved between the clamp position Pc and the standby position Pw, the stencil sheet 15 can be smoothly conveyed to the clamp position Pc without interfering with the sheet holder 14.

Further, the stencil sheet 15 has a plurality of holes 15b formed along the outer edge, and the sheet holder 14 has a plurality of protrusions 30a projecting downward from the lower surface, and the clamp position Pc of the sheet holder 14 by the lift 71 The plurality of protrusions 30a may be inserted into the plurality of holes 15b of the stencil sheet 15 by the movement. Thereby, the sheet holder 14 can be appropriately engaged with the stencil sheet 15.

Further, the sheet holder 14 may include an actuator that applies tension to the stencil sheet 15 by moving the plurality of protrusions 30a outward in the surface direction. Thereby, the sheet holder 14 can appropriately clamp the stencil sheet.

Further, the actuator may be an air cylinder operated by pneumatic pressure.

The actuator includes a first air cylinder 35a that moves protrusions 30a inserted into holes 15b formed in a pair of parallel outer edges of the stencil sheet 15 outward in the surface direction, and a first air cylinder 35a that moves the protrusions 30a that are inserted into holes 15b formed in a pair of parallel outer edges of the stencil sheet 15, and another pair of outer edges of the stencil sheet 15. The second air cylinder 35b may also include a second air cylinder 35b that moves the protrusion 30a inserted into the hole 15b formed in the hole 15b outward in a plane direction perpendicular to the direction of movement by the first air cylinder 35a.

The screen printing machine 1 also includes a sheet holder drive unit 36 that separately adjusts the air pressure supplied to the first air cylinder 35a and the air pressure supplied to the second air cylinder 35b. Since the air pressures of the first air cylinder 35a and the second air cylinder 35b are adjusted separately, the sheet holder 14 can appropriately clamp the stencil sheet 15.

Further, according to the conveying device 51 of the present embodiment, the holding part 53 that holds the stencil sheet 15 intersecting with the conveying direction is provided, and the Y-axis beam 59 that conveys the stencil sheet 15 in the conveying direction and the Y-axis beam 59 that conveys the stencil sheet 15 in the conveying direction. A pair of guide rails 55 are arranged along the conveyance direction and support the stencil sheet 15 conveyed by the Y-axis beam 59 from below. Thereby, the frameless stencil sheet 15 can be automatically replaced.

Further, the holding portion 53 has a recess 57 that attracts the stencil sheet 15. Thereby, the holding portion 53 can grip the stencil sheet 15 more reliably.

Further, the holding section 53 holds the portion of the stencil sheet 15 exposed between the pair of guide rails 55 from below, and the Y-axis beam 59 has a holding section elevating mechanism 54a that moves the holding section 53 in the vertical direction.

Further, the holding portion 53 has an upper surface 53s that contacts the lower surface of the stencil sheet 15, and a pin 58 that protrudes upward from the upper surface. do.

Further, in the holding portion 53, at least two recesses 57 are provided at intervals in the conveyance direction, and the pin 58 is arranged between the two recesses 57.

Further, a support plate 56 is provided that connects the respective tips of the pair of guide rails 55 on the attachment/detachment position Pa side, and the front edge of the stencil sheet 15 is supported on the support plate 56 at the attachment/detachment position Pa. By connecting the tips of the guide rails 55 to each other by the support plate 56, the front part of the stencil sheet 15 that has arrived at the attachment/detachment position Pa can ride on the support plate 56 and be supported. Thereby, the stencil sheet 15 and the sheet holder 14 can be stably attached and detached.

Further, the guide rail 55 may have a hole 55c to avoid interference with the downwardly protruding protrusion 30a of the seat holder 14. As a result, the protrusion 30a of the sheet holder 14 can pass through the hole 15b of the stencil sheet 15 and reach the hole 55c of the guide rail 55, so that the protrusion 30a of the sheet holder 14 can pass through the hole 15b of the stencil sheet 15. can be prevented.

Further, according to the magazine 81 of the present embodiment, the magazine 81 stores a plurality of stencil sheets 15, and includes a guide section 82 that guides the stencil sheets 15 in the loading/unloading direction, and a stencil sheet 15 fixed to the guide section 82. A fixing part 83 is provided. Thereby, even if the stencil sheet 15 has no frame, the fixing section 83 fixes the stencil sheet 15 to the guide section 82, so that the stencil sheet 15 can be prevented from moving within the magazine 81.

Further, the fixing portion 83 may be fixed by pressing the stencil sheet 15 against the first guide plate 82a and the second guide plate 82b. Since the fixing part 83 presses the stencil sheet 15 against the guide part 82, it is possible to prevent the stencil sheet 15 from moving within the magazine 81.

The fixing portion 83 also includes a loading/unloading port 81f for loading/unloading the stencil sheet 15, and a back wall 81e disposed at the back of the loading/unloading port 81f. It has a bent part 83b which is an elastic member inserted into the formed hole 15b, and the stencil sheet 15 is fixed by the fixing part 83 inserted into the hole 15b, the back wall 81e, and the bent part 83b. This positions the stencil sheet 15 housed in the magazine 81, making it suitable as a magazine for automatic replacement of the stencil sheet 15.

Further, the tip portion 82c of the guide portion 82 on the opposite side to the back wall 81e may have an inclined surface that slopes downward. This can prevent the stencil sheet 15 from getting caught on the tip end 82c of the guide section 82 when the stencil sheet 15 is taken in and out.

Further, a plurality of magazines 81 may be connectable. Thereby, the weight of each magazine 81 can be reduced, and the effort required by the operator to carry the magazine 81 can be reduced.

The magazine 81 also has a protrusion 86 along the side of the upper wall 81a, and a recess 87 corresponding to the protrusion 86 along the side of the lower wall 81d of the magazine 81. is inserted into the recess 87 of the other magazine 81, and the other magazine 81 is fixed on top of one magazine 81. This allows multiple magazines to be stably assembled vertically.

In the above-described embodiment, the driving unit that applies tension to the stencil sheet 15 by driving the four connecting members 30 such that the opposing ones of the four connecting members 30 move relative to each other in a direction away from each other. Although a cylinder (drive cylinder 35) is shown, it does not necessarily have to be a cylinder.

Furthermore, in the embodiment described above, the means for connecting the edges along the four sides of the stencil sheet 15 and the four connecting members 30 are connected to the connecting holes 15b provided at the edges of the stencil sheet 15 and each connecting member 30. Although the connecting protrusion 30a is provided and fitted into the connecting hole 15b, the present invention is not limited thereto. The edges of the stencil sheet 15 and the four connecting members 30 may be connected by other means. For example, the stencil sheet 15 may have a bent portion in which the four sides are bent inward, and the sheet holder 14 may have a claw that removably engages with the bent portion of the stencil sheet 15. Note that, as described above, the connection members 30 and the stencil sheet 15 are connected by fitting the connection protrusions 30a provided on each connection member 30 into the holes 15b provided on the edge of the stencil sheet 15. Thus, the connection member 30 and the stencil sheet 15 can be connected with an extremely simple structure, and the cost of the screen printing machine 1 can be reduced.

Although this disclosure has been fully described with reference to preferred embodiments and with reference to the accompanying drawings, various variations and modifications will become apparent to those skilled in the art. It is to be understood that such variations and modifications are included insofar as they do not depart from the scope of the disclosure as defined by the appended claims. Furthermore, changes in the combination and order of elements in each embodiment can be realized without departing from the scope and spirit of the present disclosure.

Note that by appropriately combining any of the various embodiments and modifications described above, the effects of each of them can be achieved.

The screen printing machine according to the present disclosure is applicable to a screen printing machine that uses a frameless stencil sheet.

1 Screen printer 2 Substrate 3 Electrode 8 Carrying-in port 9 Carrying-out port 10 Base 11 Board carrying-in conveyor 12 Board holding unit 13 Board carrying-out conveyor 14 Sheet holder 14a Holder frame 14b Hole 15 Stencil sheet 15a Opening 15b Hole 16 Print head 17a Lower imaging Camera 17b Upper imaging camera 19 Control section 19a Image recognition section 19b Mechanism control section 19c Tension control section 19d Storage section 21 Unit base 22 Conveyor 23 Lifting cylinder 25 Board holder 30 Connection member 30a Projection 31 First connection member 32 Second connection member 35a First air cylinder 35b Second air cylinder 44 Squeegee 51 Conveying device 53 Holding part 54a Holding part elevating mechanism 55 Guide rail 55a Horizontal part 55b Wall part 55c Hole (relief part)
56 Support plate 57 Recess 57a Suction hole 58 Pin 59 Y-axis beam 61 Suction device 71 Lift 81 Magazine 81a Upper wall 81b, 81c Side wall 81d Lower wall 81e Back wall 82 Guide part 82a First guide plate 82b Second guide plate 82c Tip part 83 Fixed part 83a Plate part 83b Bend part 85 Shelf plate 85a Tip part 86 Projection part 87 Recessed part 91 Magazine elevator Pa Attachment/detaching position Pc Clamp position Pw Standby position

Claims (14)

a magazine that stores a stencil sheet having openings corresponding to the electrodes on the substrate;
a sheet holder that removably holds the edge of the stencil sheet;
a conveyance device that conveys the stencil sheet between the magazine and the sheet holder;
a print head that fills the opening with paste placed on the stencil sheet held by the sheet holder;
Equipped with
The transport device is
a moving body that has a holding part that holds the stencil sheet and transports the stencil sheet in a transport direction;
a pair of guide rails arranged along the conveyance direction of the stencil sheet and supporting the stencil sheet conveyed by the movable body from below;
A screen printing machine equipped with The conveyance device conveys the stencil sheet below the sheet holder,
The sheet holder is configured to attach and detach the stencil sheet to a lower part of the sheet holder.
A screen printing machine according to claim 1. The sheet holder clamps the stencil sheet by applying tension in a surface direction.
A screen printing machine according to claim 1 or 2. a lift that moves the sheet holder between a lower clamp position for clamping the stencil sheet and an upper standby position;
A screen printing machine according to claim 2 or 3. The stencil sheet has a plurality of holes formed along the outer edge,
The seat holder includes a plurality of protrusions projecting downward,
When the sheet holder is moved to the clamp position by the lift, the plurality of protrusions are inserted into the plurality of holes of the stencil sheet.
A screen printing machine according to claim 4. The sheet holder includes an actuator that applies tension to the stencil sheet by moving the plurality of projections outward in a surface direction.
A screen printing machine according to claim 5. The actuator is an air cylinder operated by pneumatic pressure.
A screen printing machine according to claim 6. The actuator includes a first air cylinder that moves protrusions inserted into holes formed on a pair of parallel outer edges of the stencil sheet outward in a surface direction, and a first air cylinder formed on the other outer edge of the stencil sheet. a second air cylinder that moves a protrusion inserted into the hole outward in a plane direction perpendicular to the direction of movement by the first air cylinder;
A screen printing machine according to claim 6. comprising a seat holder drive unit that separately adjusts air pressure supplied to the first air cylinder and air pressure supplied to the second air cylinder;
A screen printing machine according to claim 8. The holding section has a suction section that suctions the stencil sheet.
A screen printing machine according to claim 1. The holding portion holds a portion of the stencil sheet exposed between the pair of guide rails from below,
The movable body has a vertical drive unit that moves the holding unit in the vertical direction.
A screen printing machine according to claim 10. The holding part is
an upper surface that contacts the lower surface of the stencil sheet;
a pin protruding upward from the top surface;
The suction part has an opening on the upper surface and suctions and holds the lower surface of the stencil sheet.
A screen printing machine according to claim 11. In the holding part, at least two suction parts are provided at intervals in the conveying direction, and the pin is arranged between the two suction parts.
A screen printing machine according to claim 12 . The guide rail has a relief part for avoiding interference with a projection protruding downward from the seat holder.
Screen printing machine according to any one of claims 1, 10 to 13.

Images