JP5906398B2 - Screen printing apparatus and mask positioning method in screen printing apparatus - Google Patents

Description

  The present invention relates to a screen printing apparatus for printing a paste on a substrate by sliding a squeegee on a mask in contact with the substrate, and a mask positioning method in the screen printing apparatus.

  In the conventional screen printing apparatus, when the mask is positioned at a predetermined mounting position with respect to the mask holder, the front edge of the mask (the edge on the front side of the mask as viewed from the operator) is aligned with a predetermined mark vertically. It was. In this case, the mark is provided on the upper surface of the camera used when aligning the mask and the substrate, and the camera is moved to the operator side before positioning the mask (for example, Patent Document 1).

JP 2007-237647 A

  However, in the conventional mask positioning method described above, skill is required to position the mask at a predetermined mounting position by accurately matching the front edge of the mask and the mark vertically. In addition, the camera needs to be moved to the operator side beyond the range of normal use when aligning the mask and the substrate, which necessitates more space on the operator side, and the screen printing device becomes larger. There was also the problem of doing.

  Therefore, the present invention can perform accurate positioning of the mask with respect to the mask holder without requiring skill, and at the same time, can prevent enlargement of the apparatus and a mask positioning method in the screen printing apparatus. The purpose is to provide.

The screen printing apparatus of the present invention is a screen printing apparatus for contacting a substrate with a mask held by a mask holder and sliding a squeegee on the mask in contact with the substrate to print a paste on the substrate, An imaging means for performing imaging by being positioned at a predetermined position capable of projecting a rear edge of the mask positioned at a predetermined attachment position with respect to the mask holder; and provided at the mask holder and positioned at the predetermined position Further, a temporary positioning position indicating unit for indicating the temporary positioning position of the mask where the trailing edge of the mask enters the imaging field of view of the imaging means, a storage unit for storing information on the temporary positioning position of the mask, and the temporary The captured image of the imaging means is displayed in a state where the mask is positioned at the positioning position, and the mask is included in the captured image. And an image display means for displaying the edge position mark after indicating the trailing edge should position the position of the mask when positioned located at a fixed mounting position, the image display unit, the provisional positioning positional indicia The temporary positioning position information indicated by is read from the storage unit and displayed .

A mask positioning method in a screen printing apparatus according to the present invention is a screen printing apparatus in which a substrate is brought into contact with a mask held by a mask holder, and a paste is printed on the substrate by sliding a squeegee on the mask in contact with the substrate. The mask positioning method in claim 1, wherein the trailing edge of the mask is within an imaging field of imaging means positioned at a predetermined position capable of projecting the trailing edge of the mask positioned at a predetermined mounting position with respect to the mask holder. A temporary positioning step of positioning the mask at a temporary positioning position indicated by a temporary positioning position indicator provided on the mask holder, and the imaging means in a state where the mask is positioned at the temporary positioning position. The captured image is displayed on the image display means, and the mask is placed in front of the captured image. An image display step of displaying a trailing edge position mark indicating a position where the trailing edge of the mask is to be positioned when positioned at a predetermined mounting position; and viewing the captured image displayed on the image display means It said trailing edge of the mask is the on the mask holder by moving the mask to fit the trailing edge position mark saw including a present positioning step of positioning the mask, the at provisional positioning step, said image display means Information on the temporary positioning position indicated by the temporary positioning position indicator is displayed .

  In the present invention, the mask holder is provided in such a manner that the trailing edge of the mask enters the imaging field of the imaging means positioned at a predetermined position where the trailing edge of the mask positioned at a predetermined mounting position with respect to the mask holder can be projected. After the mask is positioned (temporary positioning) at the temporary positioning position indicated by the provisional positioning position indicator, the trailing edge of the mask is the trailing edge while viewing the captured image of the imaging means displayed on the image display means. Mask positioning (main positioning) is performed by moving the mask on the mask holder so that it matches the position mark, and there is little room for operator differences in positioning the mask, so skill is required. Therefore, accurate positioning of the mask with respect to the mask holder can be performed. In addition, when the imaging means that projects the rear edge of the mask is used as a camera for alignment when aligning the mask and the substrate, it is necessary to move the operator beyond the range required for alignment. Therefore, a space for that purpose is unnecessary, and an increase in the size of the screen printing apparatus can be prevented.

The side view of the screen printing apparatus in one embodiment of this invention The top view of a part of screen printer in one embodiment of the present invention The block diagram which shows the control system of the screen printing apparatus in one embodiment of this invention (A) (b) The figure explaining the positioning procedure of the mask with respect to the mask holder of the screen printing apparatus in one embodiment of this invention The figure which shows an example of the display screen displayed on the display apparatus with which the screen printing apparatus in one embodiment of this invention is provided. Operation explanatory diagram of a screen printing apparatus in an embodiment of the present invention

  Embodiments of the present invention will be described below with reference to the drawings. A screen printing apparatus 1 shown in FIG. 1 is an apparatus that repeatedly executes screen printing of a paste Pst such as solder paste on a substrate 2, and is provided on a base 3 to hold and move the substrate 2. The mask holder 5 provided above the substrate holding and moving unit 4, the mask 6 held in a horizontal posture by the mask holder 5, the squeegee unit 7 provided above the mask holder 5, and the mask holder 5 can be freely moved below. The camera unit 8 is provided.

  In FIG. 1, the substrate holding / moving unit 4 includes a first lifting table 13 and a second lifting table 13 above a base table 12 that can move in a horizontal plane and rotate around a vertical axis by an XYθ moving mechanism 11 provided on a base 3. The elevating table 14 has a configuration provided in this order from below.

  The XYθ moving mechanism 11 moves on the Y-axis table 11a and the Y-axis table 11a extending on the base 3 in the Y-axis direction (the front-rear direction as viewed from the operator OP shown in FIG. 2 and the left-right direction of the drawing in FIG. 1). The X-axis table 11b provided extending in the X-axis direction (the left-right direction as viewed from the operator OP and perpendicular to the paper surface of FIG. 1) and the θ table 11c provided on the X-axis table 11b are stacked. The X axis table 11b moves on the Y axis table 11a in the Y axis direction by driving the Y axis table 11a, and the θ table 11c moves on the X axis table 11b in the X axis direction by driving the X axis table 11b. Then, the base table 12 rotates about the vertical axis (referred to as the Z-axis direction) on the paper surface of FIG. 1 by driving the θ table 11c. That is, the base table 12 is moved in the horizontal plane by the XYθ moving mechanism 11. The first lift table 13 is lifted and lowered with respect to the base table 12 by a first lift table lift motor 13m, and the second lift table 14 is lifted and lowered with respect to the first lift table 13 by a second lift table lift motor 14m.

  A pair of conveyor support members 15 are provided from the first lift table 13 so as to penetrate the second lift table 14 and extend upward. The pair of conveyor support members 15 extend in the X-axis direction and in the Y-axis direction. A pair of transport conveyors 16 disposed opposite to each other are supported. The pair of conveyors 16 supports both ends of the substrate 2 from below and conveys them in the X-axis direction. A lower receiving member 17 is provided on the upper surface of the second lifting table 14.

  A pair of clamp members (clampers 18) extending in the Y-axis direction and arranged to face each other in the X-axis direction are provided above the pair of conveyors 16. The pair of clampers 18 is opened and closed in the Y-axis direction by the operation of the clamper opening / closing cylinder 18s, and is held (clamped) by sandwiching both ends of the substrate 2 on the transport conveyor 16.

  1 and 2, the mask holder 5 extends in the Y-axis direction and is arranged to face the X-axis direction, and has a pair of mask mounting members 5a having an L-shaped cross section, and each mask mounting member 5a. It has a plurality of mask fixing cylinders 5b arranged above.

  In FIG. 2, the mask 6 is composed of a flat plate-like plate portion 6a extending in the XY plane and a frame-like portion 6b holding the outer periphery of the plate portion 6a, and the rectangular shape of the plate portion 6a surrounded by the frame-like portion 6b. A pattern hole 6 h corresponding to the electrode 2 a on the substrate 2 is provided in the region. The mask 6 is supported in such a manner that both sides of the frame-like portion 6b facing in the X-axis direction are slidably supported in the Y-axis direction on the pair of mask mounting members 5a of the mask holder 5 and are positioned at a predetermined mounting position. Then, it is held by the mask holder 5 by being pressed against the mask mounting member 5a from above by the plurality of mask fixing cylinders 5b. The attachment position of the mask 6 with respect to the mask holder 5 is individually defined according to the type of the substrate 2 to be screen printed. The positioning procedure of the mask 6 to the prescribed mounting position with respect to the mask holder 5 will be described later.

  In FIG. 2, a pair of substrate-side marks 2m are provided at diagonal positions of the substrate 2, and a set of two disposed on the plate portion 6a of the mask 6 corresponding to the substrate-side marks 2m. The mask side mark 6m is provided (see also FIG. 4B). When the substrate 2 is brought into contact with the mask 6 in a state where the substrate-side mark 2m and the mask-side mark 6m coincide with each other in plan view, the electrode 2a of the substrate 2 and the pattern hole 6h of the mask 6 are brought into agreement.

  In FIG. 1, the squeegee unit 7 includes two squeegees 22 arranged opposite to each other in the Y-axis direction below the squeegee base 21, and is moved in the Y-axis direction by the squeegee unit moving mechanism 23. The squeegee unit moving mechanism 23 includes a squeegee unit moving ball screw 23a extending in the Y-axis direction above the mask holder 5 and a squeegee unit moving motor 23b for rotationally driving the squeegee unit moving ball screw 23a. Is threaded through the squeegee base 21. Therefore, when the squeegee unit moving ball screw 23a is rotated forward and backward by the squeegee unit moving motor 23b, the squeegee base 21 reciprocates in the Y-axis direction accordingly. The two squeegees 22 are individually raised and lowered with respect to the squeegee base 21 by a squeegee lifting cylinder 24 provided on the squeegee base 21.

  1 and 2, the camera unit 8 includes an upper imaging camera 31 whose imaging field is directed upward and a lower imaging camera 32 whose imaging field is directed downward. The camera unit 8 is moved by a camera unit moving mechanism 33. It can move freely in the horizontal plane. The camera unit moving mechanism 33 includes a Y-axis guide 34 that extends in the Y-axis direction below the mask holder 5, an X-axis guide 35 that has one end attached to the Y-axis guide 34 and extends in the X-axis direction, The camera unit 8 includes a Y-axis drive motor 34 m that moves the guide 35 along the Y-axis guide 34 and an X-axis drive motor 35 m that moves the camera unit 8 provided on the X-axis guide 35 along the X-axis guide 35. Is moved in the horizontal plane by a combination of movement of the X-axis guide 35 in the Y-axis direction by the Y-axis drive motor 34m and movement of the camera unit 8 itself in the X-axis direction by driving of the X-axis drive motor 35m. .

  An operation of transporting the substrate 2 in the X-axis direction by the transport conveyor 16 provided in the substrate holding and moving unit 4, a lifting operation of the second lifting table 14 by the second lifting table lifting motor 14 m (supporting operation of the lower surface of the substrate 2 described later), Substrate clamping operation of the clamper 18 by the clamper opening / closing cylinder 18s, movement operation of the substrate 2 in the horizontal plane by the XYθ moving mechanism 11, and raising / lowering operation of the first lifting table 13 by the first lifting table lifting motor 13m (a clamped substrate to be described later) 2 is performed by the control device 40 provided in the screen printing apparatus 1 (FIG. 3). Further, the control device 40 also performs control of the movement operation of the squeegee unit 7 in the Y-axis direction by the squeegee unit moving motor 23b and the movement of the squeegee 22 by the squeegee lifting cylinder 24 (FIG. 3). Further, the operation of fixing the mask 6 to the mask holder 5 by the plurality of mask fixing cylinders 5b is also performed by the controller 40 operating each mask fixing cylinder 5b (FIG. 3).

  The control device 40 controls each of the movement operation of the camera unit 8 in the horizontal plane by the Y-axis drive motor 34m and the X-axis drive motor 35m, the imaging operation of the upper imaging camera 31 and the imaging operation of the lower imaging camera 32 provided in the camera unit 8. Made by. The image data obtained by the imaging operation of the upper imaging camera 31 and the image data obtained by the imaging operation of the lower imaging camera 32 are respectively input to the control device 40 and subjected to image recognition processing by the image recognition unit 40a (FIG. 3). . The captured image of the upper imaging camera 31 is displayed on the display device 41 connected to the control device 40 through the display control unit 40b of the control device 40 (FIG. 3).

  2 and 4 (a) and 4 (b), a scale SC having a scale in the Y-axis direction is provided at the front position (position on the operator OP side) of one mask placing member 5a of the mask holder 5. It extends in the Y-axis direction (direction in which the mask 6 can slide relative to the mask holder 5).

  Next, an execution procedure (mask positioning method) for positioning the mask 6 with respect to the mask holder 5 performed prior to the screen printing operation by the screen printing apparatus 1 and a subsequent execution procedure for fixing the mask 6 to the mask holder 5. explain. In order to perform the positioning operation of the mask 6, first, the operator OP performs a mask positioning operation start operation specifying the type of the mask 6 to be attached from the input unit 42 (FIG. 3) connected to the control device 40.

  When receiving the operation input for starting the mask positioning operation by the operator OP, the control device 40 controls the operation of the Y-axis drive motor 34m and the X-axis drive motor 35m constituting the camera unit moving mechanism 33 to place the camera unit 8 in the horizontal plane. And a predetermined position at which the rear edge 6R of the mask 6 positioned at a predetermined mounting position with respect to the mask holder 5 (the rear edge of the frame 6b of the mask 6 as viewed from the operator OP) can be projected from below. After the upper imaging camera 31 is positioned (referred to as “imaging position”) (FIG. 4A), the captured image W (moving image) of the upper imaging camera 31 is displayed on the display screen 41a of the display device 41 (FIG. 5). To display. As described above, the upper imaging camera 31 is an imaging unit that performs imaging by being positioned at a predetermined position (imaging position) where the rear edge 6R of the mask 6 positioned at a predetermined mounting position with respect to the mask holder 5 can be projected. ing. Note that the imaging position where the upper imaging camera 31 is positioned differs depending on the type of the substrate 2 to be subjected to the screen printing work (and therefore the type of the mask 6), but the control device 40 has the mask 6 specified by the operator OP by the input operation. Select and set as appropriate according to the type.

  As shown in FIG. 5, in the captured image W of the upper imaging camera 31 displayed on the display device 41, a trailing edge position mark composed of a straight line parallel to the extending direction (X-axis direction) of the trailing edge 6 </ b> R of the mask 6. M is displayed. The trailing edge position mark M indicates a position where the trailing edge 6R of the mask 6 should be positioned when the mask 6 is positioned at a predetermined mounting position with respect to the mask holder 5.

  When the upper imaging camera 31 is moved to the imaging position under the control of the control device 40 and the captured image W that is an image within the imaging field of the upper imaging camera 31 is displayed on the display screen 41a of the display device 41, the operator The OP places the mask 6 on the mask holder 5 by sliding the left and right sides of the frame-like portion 6b of the mask 6 on the pair of mask placement members 5a of the mask holder 5. Then, the mask 6 is slid on the mask holder 5, and the mask is positioned at the temporary positioning position indicated by the scale SC so that the rear edge 6R of the mask 6 enters the imaging field of the upper imaging camera 31 located at the imaging position. 6 is positioned (temporary positioning) (FIG. 4B).

  Here, the temporary positioning position is defined by the position of the front edge 6F of the mask 6 with respect to the mask holder 5 (the edge on the near side of the frame 6b of the mask 6 as viewed from the operator OP). The temporary positioning position is predetermined according to the type of the substrate 2, and the operator OP reads the position from the scale SC. Then, the front edge 6F of the mask 6 is positioned at a temporary positioning position corresponding to the mask 6. As described above, in the present embodiment, the scale SC is provided in the mask holder 5, and the temporary positioning position of the mask 6 where the trailing edge 6R of the mask 6 enters the imaging field of view of the upper imaging camera 31 positioned at the imaging position. It is a temporary positioning position marking part for marking.

  Here, information on which position on the scale of the scale SC the temporary positioning position of the mask 6 corresponding to the type of the substrate 2 (the position of the front edge 6F of the mask 6) corresponds, as shown in FIG. An image is displayed on the temporary positioning position image display unit 41 b in the display screen 41 a of the display device 41. At this time, the control device 40 reads information on the temporary positioning position of the mask 6 corresponding to the type of the substrate 2 designated by the operator OP from the input unit 42 from the storage unit 40c (FIG. 3) and displays it on the display device 41. The scales shown in the temporary positioning position image display unit 41b correspond to the scales on the scale SC. For this reason, the operator OP looks at the display screen 41a of the display device 41 and temporarily displays the mask 6 during temporary positioning. The positioning position can be confirmed.

  The temporary positioning position of the mask 6 may be indicated by writing a mark or the like on the scale SC instead of displaying an image on the display screen 41a of the display device 41 as described above. Alternatively, a correspondence table describing the correspondence between the type of the substrate 2 and the scale position of the scale SC may be prepared and attached to a position that is easy for the operator OP to view. Alternatively, the temporary positioning position may be marked with a mark or the like on the upper surface position (position where the scale SC is attached) in front of the mask placing member 5a of the mask holder 5 without using the scale SC.

  When the operator OP performs the temporary positioning of the mask 6 as described above, the trailing edge 6R of the mask 6 enters the imaging field of the upper imaging camera 31, and the captured image W of the upper imaging camera 31 displayed on the display device 41. The trailing edge position mark M is projected together with the trailing edge 6R of the mask 6 (FIG. 5). That is, the control device 40 displays the captured image W of the upper imaging camera 31 on the display device 41 in a state where the mask 6 is positioned at the temporary positioning position (temporary positioning), and the mask 6 is included in the captured image W. A rear edge position mark M indicating the position where the rear edge 6R of the mask 6 should be positioned when positioned at a predetermined mounting position is displayed (image display step). At this time, the display device 41 displays the captured image W of the upper imaging camera 31 in a state where the mask 6 is positioned (temporarily positioned) at the temporary positioning position, and the mask 6 is in the specified mounting position in the captured image W. When the positioning position of the mask 6 is reached, it functions as an image display means for displaying the trailing edge position mark M indicating the position where the trailing edge 6R of the mask 6 should be positioned.

  When the trailing edge 6R of the mask 6 is projected together with the trailing edge position mark M in the captured image W of the upper imaging camera 31 displayed on the display device 41, the operator OP views the captured image W displayed on the display device 41. On the other hand, the mask 6 is moved on the mask holder 5 so that the trailing edge 6R of the mask 6 is aligned with the trailing edge position mark M to perform positioning (main positioning) of the mask 6 (main positioning step).

  When the positioning operation of the mask 6 with respect to the mask holder 5 is completed after the main positioning step is completed, the operator OP performs the fixing operation of the mask 6 with respect to the mask holder 5. The operator OP operates the execution button 41c (FIG. 5) displayed on the display screen 41a of the display device 41 to move to the fixing operation of the mask 6 as it is after the positioning operation of the mask 6 to fix the mask 6. If not, the interrupt button 41d (FIG. 5) displayed on the display screen 41a is operated. When receiving the operation input of the execution button 41 c, the control device 40 operates the mask fixing cylinder 5 b to fix the mask 6 to the mask holder 5. Thereby, the fixing operation of the mask 6 to the mask holder 5 is completed.

  When the work for fixing the mask 6 to the mask holder 5 is completed as described above, the operator OP performs a predetermined screen printing work start operation from the input unit 42. Upon receiving the screen printing operation start operation, the control device 40 receives the substrate 2 loaded from the outside of the screen printing device 1 by the transport conveyor 16 and transports the substrate 2 to a lower work position between the pair of clampers 18. Position. The second elevating table 14 is raised with respect to the first elevating table 13, and the lower surface of the substrate 2 is supported by the lower receiving member 17, and then the second elevating table 14 is raised to lift the substrate 2 from the transport conveyor 16. The both ends of the substrate 2 are clamped and held from the Y-axis direction by the pair of clampers 18.

  After clamping the substrate 2, the control device 40 moves the camera unit 8 into the lower region of the mask 6, and images the substrate side mark 2 m provided on the substrate 2 from above the substrate 2 by the lower imaging camera 32. Image data of the mark 2m is acquired, and then the mask side mark 6m provided on the mask 6 is imaged by the upper imaging camera 31 from below the mask 6 to acquire image data of the mask side mark 6m. Then, the position of the substrate 2 is calculated by performing image recognition based on the image data of the obtained substrate side mark 2m, and the position of the mask 6 is calculated by performing image recognition based on the image data of the mask side mark 6m.

  After calculating the position of the substrate 2 and the position of the mask 6, the control device 40 moves the camera unit 8 to a position outside the area below the mask 6. Then, the operation control of the XYθ moving mechanism 11 is performed to move the substrate 2 so that the substrate side mark 2m is positioned immediately below the mask side mark 6m. As a result, the substrate 2 is aligned with the mask 6.

  After positioning the substrate 2 with respect to the mask 6, the control device 40 raises the first lifting table 13 of the substrate holding and moving unit 4 with respect to the base table 12 (arrow A shown in FIG. 6), and the substrate 2. And the upper surface of the clamper 18 are brought into contact with the lower surface of the mask 6 (FIG. 6). As a result, the electrode 2a of the substrate 2 and the pattern hole 6h of the mask 6 are brought into alignment.

  When the control device 40 brings the substrate 2 into contact with the mask 6, one of the squeegees 22 is lowered with respect to the squeegee base 21, and the lower end of the squeegee 22 is brought into contact with the mask 6, so By doing so (arrow B shown in FIG. 6), the squeegee 22 is slid on the mask 6. As a result, the paste Pst previously supplied onto the mask 6 is scraped by the squeegee 22, and the paste Pst on the mask 6 is transferred to the electrode 2 a of the substrate 2.

  In the transfer process of the paste Pst, the control device 40 moves forward (left side of the paper in FIG. 6) when moving the squeegee base 21 from the front to the rear of the screen printing apparatus 1 (from left to right in FIG. 6). ) Squeegee 22 is brought into contact with the mask 6, and when the squeegee base 21 is moved from the rear to the front of the screen printing apparatus 1 (from right to left in FIG. 6), it is moved backward (to the paper of FIG. 6). The squeegee 22 located on the right side)) is brought into contact with the mask 6.

  When the transfer operation of the paste Pst is completed, the control device 40 lowers the first lifting table 13 and separates the substrate 2 from the mask 6, and further separates the plate 2. After releasing the holding (clamping), the second elevating table 14 is lowered and the substrate 2 is lowered onto the conveyor 16. Then, the conveyance conveyor 16 is operated to carry out the substrate 2 to the outside of the screen printing apparatus 1. As a result, the screen printing operation for one substrate 2 is completed.

  As described above, in the screen printing apparatus 1 and the mask positioning method in the screen printing apparatus 1 according to the present embodiment, the predetermined edge capable of projecting the rear edge 6 </ b> R of the mask 6 positioned at the specified mounting position with respect to the mask holder 5. Temporary positioning position marking section (scale SC) provided on the mask holder 5 so that the trailing edge 6R of the mask 6 enters the imaging field of view of the upper imaging camera 31 located at the position (imaging position). After positioning the mask 6 at the positioning position (temporary positioning), the rear edge 6R of the mask 6 is aligned with the rear edge position mark M while viewing the captured image W of the upper imaging camera 31 displayed on the display device 41. The mask 6 is moved on the mask holder 5 to position the mask 6 (main positioning). Since room is less individual difference of the operator OP occurs during positioning, skill without the need for, it is possible to perform accurate positioning of the mask 6 with respect to the mask holder 5. The upper imaging camera 31 that projects the rear edge 6R of the mask 6 is also used as an alignment camera when aligning the mask 6 and the substrate 2, but exceeds the range necessary for alignment. Since it is not necessary to move to the operator OP side, the space for that is unnecessary, and the enlargement of the screen printing apparatus 1 can be prevented.

  Provided are a screen printing apparatus and a mask positioning method in a screen printing apparatus that can accurately position a mask with respect to a mask holder without requiring skill and can prevent an increase in size of the apparatus.

DESCRIPTION OF SYMBOLS 1 Screen printer 2 Board | substrate 5 Mask holder 6 Mask 6F Front edge 6R Rear edge 22 Squeegee 31 Upper imaging camera (imaging means)
41 Display device (image display means)
SC scale (temporary positioning position marking part)
M Trailing edge position mark W Captured image Pst Paste

Claims (2)

A screen printing apparatus for bringing a substrate into contact with a mask held by a mask holder and sliding a squeegee on the mask in contact with the substrate to print a paste on the substrate,
An imaging means for performing imaging by being positioned at a predetermined position capable of projecting a rear edge of the mask positioned at a predetermined mounting position with respect to the mask holder;
A temporary positioning position indicating unit that is provided in the mask holder and indicates the temporary positioning position of the mask where the trailing edge of the mask enters the imaging field of the imaging means positioned at the predetermined position;
A storage unit for storing information on a temporary positioning position of the mask;
The captured image of the imaging means is displayed in a state where the mask is positioned at the temporary positioning position, and when the mask is positioned at the specified mounting position in the captured image, the rear of the mask is displayed. Image display means for displaying a trailing edge position mark indicating a position where the edge should be located ;
The screen printing apparatus , wherein the image display means reads out and displays information on a temporary positioning position indicated by the temporary positioning position indication unit from the storage unit . A mask positioning method in a screen printing apparatus for contacting a substrate to a mask held by a mask holder and sliding a squeegee on the mask in contact with the substrate to print a paste on the substrate,
The mask holder is placed on the mask holder so that the trailing edge of the mask enters the imaging field of the imaging means located at a predetermined position where the trailing edge of the mask positioned at a predetermined mounting position with respect to the mask holder can be projected. A temporary positioning step of positioning the mask at a temporary positioning position indicated by the provisional positioning position indicator provided;
When the mask is positioned at the temporary positioning position, the captured image of the imaging unit is displayed on the image display unit, and when the mask is positioned at the specified mounting position in the captured image, An image display step of displaying a trailing edge position mark indicating a position where the trailing edge is to be located;
A main positioning step of positioning the mask by moving the mask on the mask holder so that the trailing edge of the mask is aligned with the trailing edge position mark while viewing the captured image displayed on the image display means; only including,
The mask positioning method in a screen printing apparatus , wherein in the temporary positioning step, the image display means displays information on a temporary positioning position marked by the temporary positioning position marking unit .

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