JP2013199072A - Screen printing machine and mask cleaning method in screen printing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screen printing machine which prevents a new substrate from being screen printed in the state that a part of residual solder on the lower surface of a mask is projected inside an opening part of the mask, to improve a quality pass ratio of a product substrate, and to provide a mask cleaning method in the screen printing machine.SOLUTION: An image G5 of a mask 14 after releasing a printing plate is obtained while an image G1 of the mask 14 before contacted to a substrate 2 is obtained. Then, the images G1, G5 of these both masks 14 are overlapped to form an overlapped image G6 and it is detected based on the overlapped image G6 whether there is a solder Sd projecting inside an opening part 14h of the mask 14 after releasing a printing plate. Then, when it is detected that there is the solder Sd projecting inside the opening part 14h of the mask 14, cleaning of the mask 14 is carried out by a cleaning unit 18.

Description

  The present invention relates to a screen printing machine for transferring solder to an electrode on a substrate using a mask and a squeegee, and a mask cleaning method in the screen printing machine.

  In a component mounting system for mounting components on a substrate, a screen printer for applying solder to the electrodes is provided on the upstream process side of the component mounting machine for mounting components on the electrodes of the substrate. In this screen printing machine, the squeegee is slid on the upper surface of the mask in a state where the mask in which the opening corresponding to the arrangement of the electrode of the substrate is formed is in contact with the substrate, and the solder supplied on the mask is opened to the mask. The solder is transferred to the electrodes of the board by being pushed into the part. After transferring the solder to the electrodes of the substrate, the substrate is separated from the mask and separated from the plate, and after the separation of the plate, the cleaning unit is slid on the lower surface of the mask to clean the mask. (For example, Patent Document 1). In this mask cleaning, the remaining solder residue on the lower surface of the mask can be wiped off and removed, so that in the next screen printing, the remaining solder used in the previous screen printing is applied to the electrodes on the new board. It is possible to prevent a situation in which wrinkles adhere and a printing error occurs.

JP 2004-66832 A

  However, the cleaning of the mask by the cleaning unit is insufficient, and a part of the solder remaining on the lower surface of the mask still protrudes into the mask opening even after the mask cleaning. However, there is a problem that solder is likely to adhere to the electrodes of the new substrate, which may cause a printing mistake and reduce the yield rate of the production substrate.

  Therefore, the present invention improves the yield of non-defective products on the production board by preventing screen printing of a new board from being performed with a part of the solder remaining on the lower surface of the mask protruding inside the opening of the mask. It is an object of the present invention to provide a screen printer that can be used and a mask cleaning method in the screen printer.

  The screen printing machine according to claim 1, wherein the mask is formed with an opening corresponding to the arrangement of the electrode portion of the substrate, and the upper surface of the mask is slid while the mask is in contact with the substrate. A squeegee that pushes the solder supplied onto the mask into the opening of the mask and transfers it to the electrode portion of the substrate, and the substrate on which the solder is transferred to the electrode portion by sliding the squeegee on the mask Screen printing on a substrate, comprising: a plate separating mechanism for separating the plate from the mask and separating the plate by the plate separating mechanism; and a cleaning unit for sliding the lower surface of the mask after the plate separation to clean the mask. A pre-printing machine that performs imaging of the mask before being used for the screen printing and obtains an image of the mask. Acquired by a mask image acquisition unit, a mask image acquisition unit after printing that acquires the image of the mask by imaging the mask after the plate separation, and a mask image acquisition unit before execution of printing The mask image and the mask image acquired by the post-printing mask image acquisition unit are overlapped to generate a superimposed image, and based on the generated superimposed image, the mask is released after the plate separation. The protruding solder detection means for detecting whether or not there is solder protruding inside the opening of the mask, and the presence of solder protruding inside the opening of the mask was detected by the protruding solder detection means A cleaning execution means for causing the cleaning unit to clean the mask.

  The mask cleaning method for a screen printing machine according to claim 2, wherein the mask is formed by sliding an upper surface of the mask in a state in which the mask is in contact with the substrate, the mask having an opening corresponding to the arrangement of the electrode portions of the substrate. The squeegee that moves and pushes the solder supplied onto the mask into the opening of the mask and transfers the squeegee to the electrode part of the substrate, and the solder is transferred to the electrode part by sliding the squeegee on the mask. A plate separation mechanism that separates the substrate by separating the substrate from the mask, and a cleaning unit that slides on the lower surface of the mask after the plate separation by the plate separation mechanism to clean the mask. A mask cleaning method in a screen printer for performing screen printing on a substrate, before being used for the screen printing A pre-printing mask image acquisition step of acquiring an image of the mask by performing imaging of the mask, and a post-printing mask image of acquiring the image of the mask by performing imaging of the mask after the plate separation has been performed An overlay image is generated by superimposing the mask image acquired in the acquisition step and the mask image acquired in the pre-printing mask image acquisition step and the mask image acquired in the post-print execution mask image acquisition step. Based on a superimposed image, an overhang solder detection step for detecting whether or not there is solder protruding inside the opening of the mask after the plate separation, and the opening of the mask in the overhang solder detection step Cleaning that causes the cleaning unit to clean the mask when it is detected that there is solder protruding inside And a degree.

  In the present invention, a mask image before being used for screen printing and a mask image after separation of the mask are superimposed to generate a superimposed image, and the separation of the plate is performed based on the generated superimposed image. After that, when it is detected that there is solder protruding inside the mask opening, the cleaning unit is made to clean the mask, and the solder protruding inside the mask opening is used. Since the cleaning of the mask is performed repeatedly while the mask is present, screen printing of a new board is performed with a part of the solder remaining on the lower surface of the mask protruding inside the opening of the mask. This can prevent the occurrence rate of printing errors and improve the yield rate of production substrates.

The principal part perspective view of the screen printer in one embodiment of this invention The principal part side view of the screen printer in one embodiment of this invention The block diagram which shows the control system of the screen printer in one embodiment of this invention The flowchart which shows the execution procedure of the preparation work which the screen printer in one embodiment of this invention performs The figure which shows the state which superimposes the image of a mask and the image of a board | substrate acquired in the preparatory work which the screen printing work in one embodiment of this invention performs (A) (b) The figure which shows in the preparation work which the screen printing work in one embodiment of this invention performs (a) The figure which shows an example of a superimposed image The figure which shows an example of a colored substrate image The flowchart which shows the execution procedure of the screen operation | work which the screen printer in one embodiment of this invention performs (A) (b) The figure which shows the state in which the screen printer in one embodiment of this invention is performing screen printing work (A) (b) The figure which shows the state in which the screen printer in one embodiment of this invention is performing screen printing work The figure which shows the state which the screen printer in one embodiment of this invention is cleaning the mask The figure which shows the state which the screen printer in one embodiment of this invention superimposes the mask image acquired in the preparatory work, and the mask image acquired in the screen printing work. The figure which shows an example of the overlay image which the screen printer in one embodiment of this invention acquired in screen printing work

  Embodiments of the present invention will be described below with reference to the drawings. A screen printing machine 1 shown in FIGS. 1 and 2 is incorporated in a component mounting system for mounting components on a substrate 2 and performs a screen printing operation (screen printing operation) on the electrode portion 2a of the substrate 2. A substrate holding unit moving mechanism 11 provided on the base 10, a substrate holding unit 12 moved by the substrate holding unit moving mechanism 11, a mask holder 13 set above the substrate holding unit 12, and a mask holder 13 Of the mask 14 held in a horizontal position by the lens, the camera unit 15 provided movably below the mask 14, the squeegee unit 16 provided movably above the mask 14, the inspection camera 17, and the mask 14. A cleaning unit 18 is provided below. In the following description, the transport direction of the substrate 2 is the X-axis direction (the left-right direction viewed from the operator OP), and the horizontal plane direction orthogonal to the X-axis is the Y-axis direction (the front-back direction viewed from the operator OP). . The vertical direction is the Z axis.

  In FIG. 1, the mask holder 13 includes a pair of left and right mask mounting members 13a extending in the Y-axis direction and facing the X-axis direction and having a “L” cross section. The mask 14 is a mask main body 14a made of a thin metal and made of a rectangular plate-like member, a sheet member 14b made of resin (for example, polyester) attached to the outer edge of the mask main body 14a, and a rectangle that supports the outer edge of the sheet member 14b. The mask main body 14a is provided with a large number of openings 14h corresponding to the electrode portions 2a of the substrate 2.

  In FIG. 1, two substrate side marks 2m are provided at one diagonal position on the substrate 2, and two mask side marks 14m corresponding to these two substrate side marks 2m are provided on the mask body 14a. Is provided. When the substrate 2 is raised with the two substrate-side marks 2m and the two mask-side marks 14m facing each other and the substrate 2 is brought into contact with the mask 14, the electrodes 2a of the substrate 2 and the mask body 14a are provided. The open portion 14h matches.

  1 and 2, the substrate holding unit 12 includes a base portion 12a provided so as to be movable up and down with respect to the base 10, a substrate transport conveyor 12b attached to the base portion 12a and transporting the substrate 2 in the X-axis direction. A substrate lifting cylinder 12d that lifts and lowers the substrate 2 that has been transported by the substrate transporting conveyor 12b and positioned at a predetermined substrate holding position by the receiving member 12c, and the substrate 2 pushed up by the substrate lifting cylinder 12d It has a pair of clamp members 12e clamped and held from the direction.

  In FIG. 3, the operation control of the conveyor drive mechanism 12A composed of an actuator (not shown) for driving the substrate transport conveyor 12b, the operation control of the substrate lifting cylinder 12d, and the clamp member drive composed of an actuator (not shown) for driving the pair of clamp members 12e. The control of the clamping operation of the substrate 2 by the mechanism 12B is performed by the control device 20 provided in the screen printer 1.

  The substrate holding unit moving mechanism 11 is composed of an XYZ robot and is controlled by the control device 20 to move the substrate holding unit 12 in the horizontal plane (including rotation) and to move the substrate holding unit 12 in the vertical direction (Z-axis direction). Move (FIG. 3).

  1 and 2, the camera unit 15 includes a lower imaging camera 15 a with an imaging field of view directed downward, and an upper imaging camera 15 b with an imaging field of view directed upward, and the camera unit that is operated and controlled by the control device 20. It moves in the horizontal plane below the mask 14 held by the mask holder 13 by the moving mechanism 15M (FIG. 3).

  The imaging operation of the lower imaging camera 15a and the imaging operation of the upper imaging camera 15b are controlled by the control device 20, and image data obtained by the imaging operation of the lower imaging camera 15a and image data obtained by the imaging operation of the upper imaging camera 15b. Is sent to the control device 20 (FIG. 3).

  1 and 2, the squeegee unit 16 is disposed below the base portion 16a that is movable in the Y-axis direction above the mask 14 by the operation of a squeegee unit moving mechanism 16A (FIG. 3) comprising a rectangular coordinate robot (not shown). The squeegee 16b has a configuration including two squeegees 16b provided to face each other in the Y-axis direction, and each squeegee 16b is independently formed by two pneumatic cylinders 16c attached to the base portion 16a. It is designed to be moved up and down. Operation control of the squeegee unit moving mechanism 16A and elevation control of the squeegee 16b by operation of each pneumatic cylinder 16c are performed by the control device 20 (FIG. 3).

  1 and 2, the base portion 16a of the squeegee unit 16 is provided with a solder supply syringe 16d for discharging the solder Sd from the discharge port directed downward. The supply control of the solder Sd by the solder supply syringe 16d is performed when the control device 20 controls the operation of the solder discharge mechanism 16B including an actuator (not shown) (FIG. 3).

  1 and 2, the inspection camera 17 is provided so as to be movable in the horizontal plane direction and the vertical direction with the imaging field of view facing downward. The movement operation of the inspection camera 17 is performed when the control device 20 controls the operation of the inspection camera moving mechanism 17M from an actuator or the like (not shown) (FIG. 3). The imaging operation by the inspection camera 17 is controlled by the control device 20, and image data obtained by the imaging operation of the inspection camera 17 is transmitted to the control device 20 (FIG. 3).

  1 and 2, the cleaning unit 18 spans between two rotating bodies 21a and 21b (a feeding-side rotating body 21a and a winding-side rotating body 21b) that are rotatably provided around the X axis. The paper member 22 is pushed upward by a nozzle 23 provided extending in the X-axis direction, and the two rotating bodies 21a and 21b are driven in the same direction to move the paper member 22 in the Y-axis direction. By proceeding, the cleaning part located on the upper surface of the nozzle 23 of the paper member 22 is updated. A vacuum suction port is provided at the upper end of the nozzle 23 so as to be in contact with the lower surface of the mask 14 through the paper member 22 from below.

  The cleaning unit 18 can be moved up and down with respect to the mask 14 below the mask 14 by a cleaning unit moving mechanism 18A (FIG. 3) composed of a Cartesian coordinate robot (not shown) and is movable in the Y-axis direction. The operation of the cleaning unit moving mechanism 18A is controlled by the control device 20 (FIG. 3). Further, the operation of causing the paper member 22 to advance and updating the cleaning portion of the paper member 22 stretched over the upper surface of the nozzle 23 is performed by a rotating body drive motor in which the control device 20 drives the two rotating bodies 21a and 21b described above. This is done by actuating 21A (FIG. 3). Further, the vacuum suction operation through the vacuum suction port of the nozzle 23 is performed when the control device 20 controls the operation of a suction mechanism 18B (FIG. 3) including an actuator (not shown).

  Before the screen printer 1 having such a configuration performs a screen printing operation, a preparatory operation shown in the flowchart of FIG. 4 is performed. In the preparatory work, the control device 20 first loads the substrate 2 loaded from the outside of the screen printer 1 by the substrate transport conveyor 12b and positions it at a predetermined work position. Then, the substrate 2 is pushed up by the substrate lifting cylinder 12d, the operation of the clamp member driving mechanism 12B is controlled, and the substrate 2 is held by the clamp member 12e (substrate loading and holding step; step ST1 shown in FIG. 4).

  After carrying in and holding the substrate 2, the control device 20 controls the operation of the camera unit moving mechanism 15M to move the camera unit 15, and before being used for screen printing by the upper imaging camera 15b (contacted with the substrate 2). The image of the mask 14 (before scanning) is taken (scanned), and an image G1 (FIG. 5) of the mask 14 is acquired (mask image acquisition step before printing, step ST2 shown in FIG. 4).

  As described above, the upper imaging camera 15b functions as a pre-printing mask image acquisition unit that acquires the image G1 of the mask 14 by imaging the mask 14 before being used for screen printing (before being contacted with the substrate 2). .

  When acquiring the image G1 of the mask 14, the control device 20 controls the operation of the camera unit moving mechanism 15M to move the camera unit 15, and acquires the image G2 (FIG. 5) of the substrate 2 by the lower imaging camera 15a ( Substrate image acquisition step (step ST3 shown in FIG. 4).

  Thus, the lower imaging camera 15a functions as a substrate image acquisition unit that acquires an image of the substrate 2 by imaging the substrate 2 before screen printing.

  When the image of the substrate 2 is acquired, the control device 20 superimposes the image G1 of the mask 14 acquired in step ST2 and the image G2 of the substrate 2 acquired in step ST3 on the colored substrate image creation unit 20a (FIG. 3). Thus, a superimposed image G3 (FIG. 6A) is generated (pre-printed superimposed image generation step; step ST4 shown in FIG. 4). Then, a colored substrate image G4 (FIG. 6B) in which the color of the substrate 2 and a color that can be identified in image recognition are colored in the region corresponding to the opening 14h of the mask 14 in the generated superimposed image G3. Create (colored substrate image creation step. Step ST5 shown in FIG. 4).

  The region corresponding to the opening 14h of the mask 14 in the colored substrate image G4 obtained here represents the solder Sd to be printed on the electrode portion 2a of the substrate 2 by the screen printer 1, and the region in the colored substrate image G4 The printing state (position, shape, area, etc.) of each solder Sd on the substrate 2 represents the state (position, shape, area, etc.) of each solder Sd to be printed on the substrate 2 by the screen printer 1. For example, when the color of the substrate 2 is a dark color such as black or dark green, the color of the substrate 2 and the color that can be clearly distinguished from the dark color such as white are used. means.

  After creating the colored substrate image G4 in step ST5, the control device 20 performs image recognition based on the created colored substrate image G4 in the reference image data creation unit 20b (FIG. 3) to create inspection reference image data. (Reference image data creation step. Step ST6 shown in FIG. 4). In the image recognition performed here, since the color of the substrate 2 and the color colored in the area corresponding to the opening 14h of the mask 14 can be distinguished, the inspection OP can be performed without performing visual or manual input work by the operator OP. Reference image data is obtained.

  As described above, the colored substrate image creation unit 20a of the control device 20 acquires the image G1 of the mask 14 acquired by the upper imaging camera 15b that is the pre-printing mask image acquisition unit and the lower imaging camera 15a that is the substrate image acquisition unit. A superimposed image G3 is generated by superimposing the image G2 of the substrate 2 thus formed, and the region corresponding to the opening 14h of the mask 14 in the generated superimposed image G3 is identified in the color and image recognition of the substrate 2. It functions as a colored substrate image creating means for creating a colored substrate image G4 colored with a color. In addition, the reference image data creation unit 20b of the control device 20 creates the reference image data for inspection by performing image recognition based on the colored substrate image G4 created by the colored substrate image creation unit 20a which is a colored substrate image creation unit. It functions as a reference image data creation means.

  After creating the inspection reference image data in step ST6, the control device 20 sums the area of the opening 14h of the mask 14 from the image G1 of the mask 14 acquired in step ST2 in the solder amount calculation unit 20c (FIG. 3). Is calculated. Then, the total area of the calculated opening 14h and the thickness of the mask 14 given in advance and stored in the storage unit 20d (storage unit) (for details, the thickness t of the mask main body 14a; see FIG. 2). Based on the information, the amount of solder Sd required for each of the screen-printed substrates 2 performed using the mask 14 is calculated (solder amount calculation step, step ST7 shown in FIG. 4), and the value is stored in the storage unit. Store in 20d.

  Here, when the area of each opening 14h of the mask 14 is, for example, a rectangle as shown in the enlarged view of FIG. 5, the lengths Lm and Ln of two orthogonal sides (inner edge 14f) are obtained. The product Lm × Ln is defined as the area of the opening 14h. If the total area of the openings 14h is Sw, the amount S0 of solder Sd required for one substrate 2 is calculated as S0 = Sw × t.

  As described above, in the present embodiment, the solder amount calculation unit 20c of the control device 20 uses the image G1 of the mask 14 acquired by the upper imaging camera 15b, which is a mask image acquisition unit before printing, to the opening 14h of the mask 14. The total area Sw is calculated, and screen printing performed using the mask 14 based on the calculated total area Sw of the openings 14h of the mask 14 and the information about the thickness t of the mask 14 given in advance. It functions as a solder amount calculating means for calculating the amount of solder Sd required for one board 2.

  When the amount of solder Sd necessary for one screen-printed substrate 2 is calculated in the solder amount calculation unit 20c, the control device 20 releases the holding of the substrate 2 by the clamp member 12e, and the substrate is conveyed by the substrate transfer conveyor 12b. 2 is carried out of the screen printing machine 1 (substrate carrying-out process, step ST8 shown in FIG. 4). This completes the preparation work.

  When the preparatory work is completed, the control device 20 performs the screen printing work shown in the flowchart of FIG. In the screen printing operation, the control device 20 first loads the substrate 2 loaded from the outside of the screen printing machine 1 by the substrate transfer conveyor 12b and positions it at the predetermined work position. Then, the substrate 2 is pushed up by the substrate elevating cylinder 12d (arrow A shown in FIG. 8A) and the substrate 2 is clamped by the clamp member 12e (arrow B shown in FIG. 8A). Hold (substrate loading and holding step; step ST11 shown in FIG. 7; FIG. 8A).

  After holding the substrate 2 as described above, the control device 20 controls the operation of the camera unit moving mechanism 15M and positions the lower imaging camera 15a immediately above the substrate-side mark 2m provided on the substrate 2. The lower imaging camera 15a picks up the substrate side mark 2m and grasps the position of the substrate 2 from the image data, and the upper imaging camera 15b is positioned directly below the mask side mark 14m provided on the mask main body 14a. In addition, the upper imaging camera 15b captures the mask side mark 14m and grasps the position of the mask 14 from the image data. Then, the substrate holding unit 12 is moved in the horizontal plane direction so that the substrate side mark 2m and the mask side mark 14m face each other in the vertical direction so that the substrate 2 is aligned with the mask 14 in the horizontal plane direction (position alignment). Process, step ST12 shown in FIG.

  When the alignment of the substrate 2 with respect to the mask 14 is completed, the control device 20 controls the operation of the substrate holding unit moving mechanism 11 to raise the substrate holding unit 12 with respect to the base 10 (in FIG. 8B). Arrow C1), the substrate 2 is brought into contact with the mask 14 by bringing the upper surface of the substrate 2 held by the pair of clamp members 12e into contact with the lower surface of the mask 14 (contact process; step ST13 shown in FIG. 7; FIG. b)). Thereby, the electrode part 2a on the substrate 2 and the opening part 14h of the mask 14 are brought into a matched state.

  When the control device 20 brings the substrate 2 into contact with the mask 14, the solder supply control unit 20e (FIG. 3) determines whether or not the solder Sd needs to be supplied onto the mask 14 (solder supply execution determination step). Step ST14 in Fig. 7) As a result, when it is determined that the solder Sd needs to be supplied onto the mask 14, the operation of the squeegee unit moving mechanism 16A is controlled so that the solder supply syringe 16d is placed above the mask 14 in advance. Then, the solder discharge mechanism 16B is controlled to discharge and supply the solder Sd from the solder supply syringe 16d onto the mask 14 (solder supply step; step ST15 shown in FIG. 7).

  Here, the solder supply control unit 20e of the control device 20 determines whether or not it is necessary to supply the solder Sd onto the mask 14 for each substrate 2 calculated in step ST7 in the preparation work. This is performed based on the amount of solder Sd. For example, assuming that the amount of solder Sd required for one substrate 2 is “S0” as described above, an amount of “S0 × n” of solder Sd is obtained every time n substrates are screen printed. Before n screen printing is performed, the solder is supplied onto the mask 14 by the solder supply syringe 16d. In this case, in step ST14 in FIG. 7, it is determined that it is necessary to provide the solder Sd at a rate of once every n times.

  As described above, the total area Sw of the openings 14h of the mask 14 calculated from the image G1 of the mask 14 before being used for screen printing (before being brought into contact with the substrate 2) and the thickness of the mask 14 given in advance. Based on the information of t, the amount of solder Sd required per one board 2 of screen printing performed using the mask 14 is calculated, and the required solder Sd per one board 2 is calculated. Since the solder Sd is supplied onto the mask 14 based on the amount, an accurate amount of solder Sd without excess or deficiency can be supplied onto the mask 14.

  As described above, in the present embodiment, the solder supply syringe 16d and the solder supply control unit 20e of the control device 20 per one board 2 calculated by the solder amount calculation unit 20c of the control device 20 which is a solder amount calculation means. It functions as a solder supply means for supplying the solder Sd onto the mask 14 on the basis of the amount of solder Sd required.

  When the controller 20 supplies the solder Sd onto the mask 14 at step ST15 or determines that it is not necessary to supply the solder Sd onto the mask 14 at step ST14, the controller 20 performs squeegeeing with the squeegee 16b to obtain the mask in advance. The solder Sd supplied onto 14 is transferred to the electrode portion 2a of the substrate 2 (squeezing step; step ST16 shown in FIG. 7). Specifically, this squeezing is a state in which one of the two squeegees 16b included in the squeegee unit 16 is moved downward (arrow D1 shown in FIG. 9A) and brought into contact with the upper surface of the mask 14. This is performed by moving the base portion 16a in the horizontal direction (arrow E shown in FIG. 9A) while maintaining the above. As a result, the squeegee 16b slides on the mask 14, and the solder Sd on the mask 14 is scraped by the squeegee 16b and pushed into the opening 14h of the mask 14 and transferred onto the electrode portion 2a of each substrate 2. .

  That is, in this embodiment, the squeegee 16b slides on the upper surface of the mask 14 while the mask 14 is in contact with the substrate 2, and pushes the solder Sd supplied onto the mask 14 into the opening 14h of the mask 14. Thus, the image is transferred to the electrode portion 2a of the substrate 2.

  After transferring the solder Sd to the electrode portion 2a of the substrate 2, the control device 20 moves up the squeegee 16b that is in contact with the mask 14 (arrow D2 shown in FIG. 9B), and then the substrate. By operating the holding unit moving mechanism 11 and lowering the substrate holding unit 12, the substrate 2 is separated from the mask 14 (arrow C <b> 2 shown in FIG. 9B), and plate separation is performed (plate separation step, FIG. 7). Step ST17 shown in Fig. 9B). As a result, the solder Sd remains on the electrode portion 2 a of the substrate 2, and the solder Sd is printed on the substrate 2.

  As described above, the substrate holding unit moving mechanism 11 is a plate separation mechanism that separates the substrate 2 on which the solder Sd is transferred to the electrode portion 2a by sliding on the mask 14 of the squeegee 16b away from the mask 14. Function.

  After the separation of the plate, the control device 20 performs a post-print inspection of the substrate 2 in the post-print inspection execution unit 20f (FIG. 3) (post-print inspection step; step ST18 shown in FIG. 7). In this post-printing inspection, the control device 20 first controls the operation of the substrate holding unit moving mechanism 11 to move the substrate holding unit 12 in the horizontal direction so that the printed substrate 2 is out of the area below the mask 14. Then, the operation of the inspection camera moving mechanism 17M is controlled to move the inspection camera 17 over the printed substrate 2, and the inspection camera 17 images the various places on the printed substrate 2 so that the entire upper surface of the substrate 2 is captured. Image data of the substrate 2 after printing is created by performing image recognition of the acquired image. Then, the image data of the printed board 2 after printing is compared with the reference image data for inspection acquired in the above-described preparatory work, and whether the printing state of the solder Sd on the board 2 subjected to screen printing is normal. An inspection for negative (that is, an inspection after printing) is performed.

  After performing the post-printing inspection as described above, the control device 20 controls the operation of the substrate holding unit 12 so that the substrate 2 after printing is placed in the region below the mask 14 in the horizontal direction. To release the holding of the substrate 2 by the substrate holding unit 12 (holding release step, step ST19 shown in FIG. 7). Specifically, the release of the holding of the substrate 2 is performed by the control device 20 controlling the operation of the clamp member drive mechanism 12B to open the clamp member 12e and then operating the substrate lifting cylinder 12d to move the substrate 2 to the position. This is done by lowering and lowering both ends of the substrate 2 onto the pair of substrate transfer conveyors 12b (see FIG. 2).

  When the holding of the substrate 2 is released, the control device 20 operates the substrate conveying conveyor 12b to carry the substrate 2 out of the screen printing machine 1 (substrate carrying step, step ST20 shown in FIG. 7).

  When the control device 20 carries out the substrate 2, the cleaning execution unit 20g (FIG. 3) cleans the lower surface of the mask 14 by the cleaning unit 18 (cleaning execution step; step ST21 shown in FIG. 7).

  Specifically, the cleaning of the mask 14 is performed after the cleaning execution unit 20g of the control device 20 controls the operation of the cleaning unit moving mechanism 18A to bring the cleaning portion of the paper member 22 into contact with the lower surface of the mask 14. The cleaning unit 18 is moved in the Y-axis direction (arrow F shown in FIG. 10) while controlling the operation of the suction mechanism 18B to cause the nozzle 23 to perform vacuum suction. As a result, the solder Sd (the remaining residue of the solder Sd) adhering to the lower surface of the mask 14 is wiped off by the paper member 22.

  Here, the control device 20 determines whether or not the mask 14 needs to be cleaned based on, for example, how many times the screen printing operation for the substrate 2 has been performed continuously. Specifically, when it is determined that the mask 14 is to be cleaned every time N (for example, 10) screen printing operations are performed on the substrate 2, every time N screen printing operations are performed on the substrate 2. It is determined that the mask 14 needs to be cleaned.

  After cleaning the mask 14 in step ST21, the control device 20 images the mask 14 (the mask 14 after the plate separation is performed) with the upper imaging camera 15b, and the image G5 of the mask 14 (FIG. 11). (A mask image acquisition step after printing. Step ST22 shown in FIG. 7). Then, in the protruding solder detection unit 20h (FIG. 3) of the control device 20, the image G1 of the mask 14 acquired in step ST2 and the image G5 of the mask 14 acquired in step ST22 are overlaid to superimpose an image G6 (FIG. 12). (Post-printing superimposed image generating step; step ST23 shown in FIG. 7), and based on the generated superimposed image G6, is there any solder Sd protruding inward of the opening 14h of the mask 14? (Excess solder detection step. Step ST24 shown in FIG. 7).

  As described above, the upper imaging camera 15b functions as a post-printing mask image acquisition unit that acquires an image of the mask 14 by imaging the mask 14 after the plate separation is performed.

  As shown in the enlarged view of FIG. 12, in the image G1 of the mask 14 acquired in step ST2 and the image G5 of the mask 14 acquired in step ST22, a region corresponding to the opening 14h of each mask 14 is a perforated portion. However, in the image G1 of the mask 14 acquired in step ST2, the shape of the outer edge of the hole portion corresponding to the opening 14h is the shape of the inner edge 14f of the opening 14h, whereas the mask 14 acquired in step ST22. In the image G5, the shape of the outer edge of the hole corresponding to the opening 14h is surrounded by the inner edge 14f of the opening 14h where the solder Sd does not protrude and the outer edge Sdf of the solder Sd where the solder Sd protrudes. It becomes a shape. For this reason, when the image G1 of the mask 14 acquired in step ST2 and the image G5 of the mask 14 acquired in step ST22 are overlapped, and there are non-overlapping areas of the images G1 and G5 of both masks 14, The area is an area where the solder Sd protrudes inward of the opening 14h (the area of the solder Sd shown in the enlarged view of FIG. 12). By detecting this area, the area inside the opening 14h of the mask 14 is detected. It is possible to detect whether or not there is solder Sd that protrudes toward the surface.

  Then, as a result of detecting whether or not there is solder Sd protruding inward of the opening 14h of the mask 14 in step ST24, the control device 20 has solder Sd protruding inward of the opening 14h. If this is detected, the process returns to step ST21, and the cleaning execution unit 20g causes the cleaning unit 18 to clean the mask 14 (cleaning execution step). For this reason, the cleaning of the mask 14 is repeatedly performed while the solder Sd protruding inside the opening 14h of the mask 14 exists.

  On the other hand, when the control device 20 does not detect the presence of the solder Sd protruding inward of the opening 14h in step ST24, the series of screen printing operations is terminated.

  In the above description, the steps ST21 to ST24 are executed after the steps ST18 to ST20, but may be executed in parallel with the steps ST18 to ST20. Good.

  As described above, the protruding solder detection unit 20h of the control device 20 includes the image G1 of the mask 14 acquired by the upper imaging camera 15b that is the pre-printing mask image acquisition unit and the upper imaging camera that is the post-printing mask image acquisition unit. The superimposed image G6 is generated by superimposing the image G5 of the mask 14 acquired by 15b, and protrudes inward of the opening 14h of the mask 14 after separation of the plate based on the generated superimposed image. It functions as a protruding solder detection means for detecting whether or not there is solder Sd.

  Further, the cleaning execution unit 20g of the control device 20 performs cleaning when the protruding solder detection unit 20h, which is a protruding solder detection means, detects that there is solder Sd protruding inward of the opening 14h of the mask 14. It functions as a cleaning execution means for causing the unit 18 to clean the mask 14.

  As described above, the mask cleaning method performed by the screen printer 1 according to the present embodiment is a pre-printing mask image acquisition step of acquiring the image G1 of the mask 14 by imaging the mask 14 before being used for screen printing ( Step ST2), a mask image acquisition step after printing (step ST22) in which an image G5 of the mask 14 is acquired by imaging the mask 14 after the plate separation is performed, and a mask acquired in the mask image acquisition step before printing execution The image G1 of 14 and the image G5 of the mask 14 acquired in the post-printing mask image acquisition step are superimposed to generate a superimposed image G6. Based on the generated superimposed image G6, the mask 14 is released after the separation. A protruding solder detection step (step ST) for detecting whether or not there is a protruding solder Sd inside the opening 14h 4) and a cleaning execution step (step ST21) for causing the cleaning unit 18 to clean the mask 14 when it is detected in the protruding solder detection step that there is solder Sd protruding inside the opening 14h of the mask 14. Is included.

  As described above, in the screen printing machine 1 and the mask cleaning method using the screen printing machine 1 according to the present embodiment, the image G1 of the mask 14 before being brought into contact with the substrate 2 and the mask 14 after being separated from the plate. A superimposed image G6 is generated by superimposing the image G5, and based on the generated superimposed image G6, it is confirmed that there is solder Sd protruding inward of the opening 14h of the mask 14 after the separation of the plate. If detected, the cleaning unit 18 is made to clean the mask 14, and the mask 14 is repeatedly cleaned while the solder Sd protruding inside the opening 14h of the mask 14 is present. Therefore, the screen of the new substrate 2 is left in a state where the solder Sd protruding to the inside of the opening 14h of the mask 14 remains. It is possible to prevent the printing mistakes caused by printing is executed.

  A screen that can prevent the screen printing of a new board from being executed while a part of the solder remaining on the lower surface of the mask protrudes inward of the opening of the mask, thereby improving the yield rate of the production board. A mask cleaning method in a printing press and a screen printing press is provided.

DESCRIPTION OF SYMBOLS 1 Screen printer 2 Substrate 2a Electrode part 11 Substrate holding unit moving mechanism (plate separation mechanism)
14 Mask 14h Opening 15b Upper imaging camera (mask image acquisition means before printing execution, mask image acquisition means after printing execution)
16b Squeegee 18 Cleaning unit 20g Cleaning execution part (cleaning execution means)
20h Protruding solder detection unit (extruding solder detecting means)
Sd solder

Claims (2)

A mask in which an opening corresponding to the arrangement of the electrode portion of the substrate is formed, and the solder supplied on the mask by sliding the upper surface of the mask while the mask is in contact with the substrate. A squeegee that is pushed into the opening and transferred to the electrode portion of the substrate, and a plate that separates the plate from which the solder is transferred to the electrode portion by sliding the squeegee on the mask away from the mask. A screen printing machine for performing screen printing on a substrate, comprising: a separation mechanism; and a cleaning unit that slides on a lower surface of the mask after the plate separation by the plate separation mechanism to clean the mask,
A pre-printing mask image acquisition means for acquiring an image of the mask by imaging the mask before being used for the screen printing;
A post-printing mask image obtaining means for obtaining an image of the mask by taking an image of the mask after the plate separation has been performed;
The mask image acquired by the pre-printing mask image acquisition unit and the mask image acquired by the post-printing mask image acquisition unit are superimposed to generate a superimposed image, and the generated overlay Based on the image, a protruding solder detection means for detecting whether or not there is solder protruding inward of the opening of the mask after the plate separation,
And a cleaning execution means for causing the cleaning unit to clean the mask when the protruding solder detection means detects that there is solder protruding inside the opening of the mask. Screen printing machine. A mask in which an opening corresponding to the arrangement of the electrode portion of the substrate is formed, and the upper surface of the mask is slid in a state where the mask is in contact with the substrate, and the solder supplied on the mask is transferred to the mask. A squeegee that is pushed into the opening and transferred to the electrode portion of the substrate, and a plate that separates the plate from which the solder is transferred to the electrode portion by sliding the squeegee on the mask away from the mask. A mask cleaning method in a screen printing machine, comprising: a separation mechanism; and a cleaning unit that slides on a lower surface of the mask after the plate separation by the plate separation mechanism to clean the mask. And
A pre-printing mask image acquisition step of acquiring an image of the mask by imaging the mask before being used for the screen printing;
A post-printing mask image obtaining step of obtaining an image of the mask by taking an image of the mask after the release of the plate; and
The mask image acquired in the pre-printing mask image acquisition step and the mask image acquired in the post-printing mask image acquisition step are superimposed to generate a superimposed image, and the generated superimposed image On the basis of the protruding solder detection step of detecting whether or not there is solder protruding inward of the opening of the mask after the plate separation,
A cleaning execution step of causing the cleaning unit to clean the mask when it is detected in the protruding solder detection step that there is solder protruding inside the opening of the mask. A mask cleaning method in a screen printing machine.

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