JP7170166B2 - Screen printing device and screen printing method - Google Patents

Description

The present invention relates to a screen printing apparatus and a screen printing method for printing paste on a substrate through a mask.

A screen printing apparatus brings a mask into contact with a substrate and prints paste onto the substrate through pattern holes formed in the mask. Such a screen printing apparatus is equipped with a cleaning device that periodically scrapes off the paste from the bottom surface of the mask for cleaning (see, for example, Patent Document 1). The cleaning device of Patent Document 1 includes a holding body that holds a plurality of scraping members that scrape off the paste adhering to the lower surface of the mask, and a suction means that sucks the paste scraped off by the scraping members. Then, the scraping member is brought into contact with the lower surface of the mask and slid while being sucked by the suction means, thereby cleaning the paste adhering to the mask.

Japanese Unexamined Patent Application Publication No. 2016-196101

However, in the cleaning device described in Patent Document 1, when the paste is removed while sliding, part of the paste sucked out from the pattern holes by suction is not removed and remains on the lower surface of the mask to print. There was a problem that quality deteriorated.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a screen printing apparatus and a screen printing method that can more reliably remove paste adhering to a mask.

The screen printing apparatus of the present invention prints a mask on which pattern holes are formed, and a paste supplied onto the mask by sliding on the mask onto a substrate positioned on the lower surface of the mask through the pattern holes. a squeegee, a mask cleaner for removing the paste adhering to the lower surface of the mask, a suction part for sucking the paste adhering to the mask when the mask cleaner removes the paste, and the mask cleaner being applied to the lower surface of the mask. a first cleaning operation in which the mask cleaner is brought into contact with the mask and moved along the lower surface of the mask while being sucked by the suction unit; and a state in which the mask cleaner is brought into contact with the lower surface of the mask and suction by the suction unit is stopped. a controller for executing a second cleaning operation of moving the mask along the lower surface of the mask, wherein the controller executes the second cleaning operation after executing the first cleaning operation. and the mask cleaner has a plurality of blades arranged side by side in the moving direction and extending in a horizontal direction intersecting the moving direction of the mask cleaner for scraping off the paste in contact with the lower surface of the mask, The suction part sucks the paste from a plurality of spaces sandwiched by the blades .

In the screen printing method of the present invention, a mask having pattern holes formed thereon and a paste supplied onto the mask by sliding on the mask are printed on a substrate positioned on the lower surface of the mask through the pattern holes. A screen printing method in a screen printing apparatus comprising a squeegee, a mask cleaner for removing paste adhered to the lower surface of the mask, and a suction unit for sucking the paste adhered to the mask when the mask cleaner removes the paste. a printing step of moving the squeegee on the mask to print the paste on the substrate through the pattern holes; a first cleaning step of removing paste adhering to the lower surface of the mask with the mask cleaner; and a second cleaning step of removing the paste adhering to the lower surface of the mask with a cleaner, and after performing the first cleaning step between the printing step and the next printing step, A second cleaning step is performed, and the mask cleaner includes a plurality of blades extending in a horizontal direction intersecting the moving direction of the mask cleaner for contacting the lower surface of the mask and scraping off the paste, arranged side by side in the moving direction. The suction unit sucks the paste from a plurality of spaces sandwiched by the blades .

ADVANTAGE OF THE INVENTION According to this invention, the paste adhering to the mask can be removed more reliably.

1 is a side view for explaining the configuration of a screen printing apparatus according to one embodiment of the present invention; FIG. 1 is a plan view for explaining the configuration of a screen printing apparatus according to an embodiment of the present invention; FIG. FIG. 1 is a structural explanatory diagram of a cleaning device included in a screen printing apparatus according to an embodiment of the present invention; 1 is a perspective view of a mask cleaner that constitutes a cleaning device included in a screen printing apparatus according to an embodiment of the present invention; FIG. FIG. 1 is a flowchart of a screen printing method in a screen printing apparatus according to an embodiment of the present invention; (a) (b) (c) Process explanatory diagrams of mask cleaning in screen printing apparatus according to one embodiment of the present invention

An embodiment of the present invention will be described in detail below with reference to the drawings. The configuration, shape, etc. described below are examples for explanation, and can be changed as appropriate according to the specifications of the screen printing apparatus and the cleaning apparatus. In the following, the same reference numerals are given to the corresponding elements in all the drawings, and redundant explanations are omitted. Hereinafter, the substrate transport direction (horizontal direction in FIG. 2) is the X direction, the direction orthogonal to the X direction in the horizontal plane (horizontal direction in FIG. 1) is the Y direction, and the direction orthogonal to the horizontal plane (vertical direction in FIG. 1) is Define the Z direction.

First, the structure of the screen printing apparatus 1 will be described with reference to FIGS. 1 and 2. FIG. In FIG. 1, a substrate positioning portion 3 is installed on a base 2. As shown in FIG. The substrate positioning unit 3 is provided with an XY table 4, a θ table 5, and a substrate lifting mechanism 6 in this order from below. The XY table 4 moves the θ table 5 in the horizontal plane (X direction, Y direction). The θ table 5 rotates the substrate lifting mechanism 6 by θ around the Z axis. A substrate holder 7 is installed above the substrate lifting mechanism 6 . The substrate elevating mechanism 6 supports the substrate holder 7 from below and elevates it.

In FIG. 2, a pair of conveyors 8 extending in the X direction are installed on the base 2. As shown in FIG. The transport conveyor 8 transports the substrate 9 received from the upstream side of the screen printing device 1 in the X direction and carries it out to the downstream side of the screen printing device 1 . The substrate holder 7 is installed near the center of the transport conveyor 8 in the X direction. The substrate holding unit 7 receives the substrate 9 conveyed by the transport conveyor 8 and clamps the side surfaces of the substrate 9 in the Y direction with a pair of clamp members 10 provided in the substrate holding unit 7 to hold the substrate 9 at the clamping position.

In FIG. 1, a controller C is installed on the base 2 . The controller C controls the transport conveyor 8 to load and unload the substrate 9 . The control unit C controls the substrate positioning unit 3 (XY table 4, θ table 5, substrate elevating mechanism 6) and the substrate holding unit 7, and the substrate 9 transported to the vicinity of the center in the X direction by the transport conveyor 8 is placed on the substrate. It is held by the holding portion 7 .

A mask 11 whose periphery is supported by a frame member 11w is arranged above the substrate holding part 7 . The mask 11 is formed with a plurality of pattern holes 11a for transferring (printing) a paste such as cream solder corresponding to the shape and position of the electrodes 9a (see FIG. 2) to be printed on the substrate 9. there is Paste is supplied onto the mask 11 by a paste supply mechanism (not shown).

In FIG. 1, above the mask 11, a print head 20 is installed that is moved in the Y direction (arrow a1) by a print head moving mechanism (not shown). The print head 20 has a movement base 21 that is moved in the Y direction by a print head movement mechanism. Two squeegee holding portions 22 are arranged side by side in the Y direction on the moving base 21 . The squeegee holding portions 22 each hold a squeegee 23 extending in the X direction at its lower end, and are raised and lowered by a squeegee lifting mechanism 24 provided on the moving base 21 (arrow a2). The print head moving mechanism and print head 20 are controlled by the controller C. FIG.

In FIG. 1, a camera head unit 25 and a cleaning device 30 are installed below the mask 11 . In the present embodiment, the camera head unit 25 and the cleaning device 30 are mounted on the X-axis table 26 and configured to move integrally in the Y direction (arrow a3). The camera head unit 25 includes a board recognition camera 25a for capturing an image of the board 9 from above, and a mask recognition camera 25b for capturing an image of the mask 11 from the bottom surface 11b side. The camera head unit 25 can simultaneously recognize the substrate 9 and the mask 11 by moving in the horizontal direction.

The board recognition camera 25a takes an image of a board-side mark 9m (see FIG. 2) for alignment formed on the board 9. As shown in FIG. The mask recognition camera 25 b captures an image of a mask-side mark (not shown) for alignment formed on the mask 11 . The results of imaging by the substrate recognition camera 25a and the mask recognition camera 25b are transmitted to the controller C. FIG.

In FIG. 2, the X-axis table 26 is coupled to a Y-axis table 27 extending in the Y direction so as to be slidable in the Y direction. The Y-axis table 27 has a Y-axis movement mechanism (not shown) that horizontally moves the X-axis table 26 in the Y direction. The Y-axis movement mechanism is controlled by the controller C. FIG. The controller C moves the camera head unit 25 and the cleaning device 30 in the Y direction by controlling the Y-axis movement mechanism. When the substrate 9 is brought into contact with the lower surface 11b of the mask 11 during screen printing, which will be described later, the camera head unit 25 and the cleaning device 30 move to the waiting position on the side of the substrate holder 7 (see FIG. 1). During mask cleaning, camera head unit 25 and cleaning device 30 move between mask 11 and substrate holder 7 .

Next, screen printing for transferring the paste to the substrate 9 through the pattern holes 11a of the mask 11 will be described. Screen printing is performed by the control section C controlling each section of the screen printing apparatus 1 . First, the substrate holding unit 7 clamps and holds the substrate 9 transported by the transport conveyor 8 . Next, the camera head unit 25 images the substrate side mark 9m and the mask side mark. Next, the substrate positioning unit 3 aligns the substrate 9 with respect to the mask 11 based on the imaging result.

Next, the substrate lifting mechanism 6 lifts the substrate 9 together with the substrate holding part 7 and brings it into contact with the lower surface 11 b of the mask 11 . Next, the squeegee lifting mechanism 24 lowers the squeegee 23 to contact the upper surface of the mask 11 . The print head moving mechanism then slides the squeegee 23 over the mask 11 to transfer the paste supplied on the mask 11 to the substrate 9 . In this manner, the screen printing apparatus 1 slides the squeegee 23 over the mask 11 to print the paste supplied onto the mask 11 through the pattern holes 11a onto the substrate 9 positioned on the lower surface 11b of the mask 11. Execute printing.

Next, the configuration and function of the cleaning device 30 will be described with reference to FIGS. 3, 4, and 6. FIG. In FIG. 3, the cleaning device 30 has a box-shaped cleaner mounting portion 31 mounted on an X-axis table 26 that moves in the Y direction. A cleaner elevating mechanism 32 is installed in the cleaner attachment portion 31 , and a mask cleaner 33 is attached to the upper portion of the cleaner elevating mechanism 32 . The cleaner elevating mechanism 32 is composed of an actuator driven by air or hydraulic pressure. The cleaner lifting mechanism 32 is controlled by the controller C, and the mask cleaner 33 is lifted by driving the cleaner lifting mechanism 32 (arrow b).

3 and 4, the mask cleaner 33 has a substantially rectangular parallelepiped main body 34 having a cavity therein and extending in the X direction. A plurality (here, seven blades) of blades 35 extending in the X direction are attached to the upper portion of the body portion 34 so as to be aligned in the Y direction. That is, the plurality of blades 35 are arranged side by side in parallel with the moving direction of the mask cleaner 33 . The blade 35 is a thin “spatula-like” flexible member made of metal such as SUS or plastic. Note that the blade 35 may be formed of an elastic material such as urethane rubber.

FIG. 6A shows a cross section of the mask cleaner 33 as seen from the X direction. For convenience, the number of blades 35 included in the mask cleaner 33 shown in FIG. 6A is simplified to four. The blade 35 is attached so as to protrude upward from the upper surface of the body portion 34 . With the blade 35 in contact with the lower surface 11b of the mask 11, the blade 35 has an angle of attack θ with respect to the horizontal lower surface 11b of the mask 11 (the angle between the lower surface 11b of the mask 11 and the paste scraping surface of the blade 35). angle) is less than 90°, ie, an acute angle. That is, the blade 35 is inclined in a direction opposite to the moving direction (cleaning direction) of the mask cleaner 33 .

A plurality of openings 36 are formed between the plurality of blades 35 on the upper surface of the body portion 34 so as to penetrate from the upper surface to a hollow portion 34 a formed inside the body portion 34 . A side surface of the body portion 34 is formed with a suction port 34b penetrating to the hollow portion 34a. One end of a tube 37 is connected to the suction port 34b. In FIG. 3 , the other end of tube 37 is connected to suction section 38 . The suction portion 38 is controlled by the control portion C, and the hollow portion 34 a of the main body portion 34 is sucked by operating the suction portion 38 .

In FIG. 6(a), when the suction unit 38 operates while the blade 35 is in contact with the lower surface 11b of the mask 11, the space S surrounded by the lower surface 11b of the mask 11 and the blade 35 becomes the opening 36 of the main body 34. aspirated through When the mask cleaner 33 is moved in the cleaning direction (to the right in FIG. 6) in this state, the paste P adhering to the mask 11 is sucked into the mask cleaner 33 and removed (see FIG. 6B).

In this way, the mask cleaner 33 has a plurality of blades 35 extending in the horizontal direction (X direction) intersecting the cleaning direction (moving direction of the mask cleaner 33) and contacting the lower surface 11b of the mask 11 to scrape off the paste P. are arranged side by side in the cleaning direction. When the mask cleaner 33 removes the paste P, the suction unit 38 sucks the paste P adhering to the mask 11 from the spaces S sandwiched between the blades 35 .

Next, along the flow of FIG. 5, the screen printing method in the screen printing apparatus 1 will be described with reference to FIG. In FIG. 5 , first, the controller C loads the substrate 9 to be printed, aligns it, and brings it into contact with the lower surface 11 b of the mask 11 . Next, the controller C moves the squeegee 23 on the mask 11 to print the paste P on the substrate 9 through the pattern holes 11a (ST1: printing step). Next, the controller C lowers the substrate 9 to separate it from the lower surface 11b of the mask 11, and carries out the printed substrate 9. FIG.

Next, the controller C moves the mask cleaner 33 from the standby position to the start position where mask cleaning is started (ST2: first start position movement step). Next, the controller C raises the mask cleaner 33 to bring the blade 35 (mask cleaner 33) into contact with the lower surface 11b of the mask 11 (arrow c in FIG. 6A). Next, the controller C activates the suction unit 38 to perform a first cleaning operation in which the mask cleaner 33 is moved along the lower surface 11b of the mask 11 while being sucked by the suction unit 38 (FIG. 6B). .

That is, the mask cleaner 33 removes the paste P adhering to the lower surface 11b of the mask 11 while being sucked by the suction unit 38 (ST3: first cleaning step). As a result, the paste P adhering to the pattern holes 11 a of the mask 11 is sucked out to the lower surface 11 b of the mask 11 and sucked into the mask cleaner 33 . In FIG. 6B, the paste P sucked out of the pattern hole 11a by suction is applied to the lower surface 11b of the mask 11 near the pattern hole 11a behind the moving mask cleaner 33 (the area indicated by the broken line d). The mask cleaner 33 cannot completely absorb it and some of it remains. This is because, during the first cleaning operation, the paste P in the pattern holes 11a of the mask 11 does not adhere to the back surface (lower surface 11b) of the mask 11 even after the blade 35 has passed through the pattern holes 11a of the mask 11 due to the negative pressure of the suction unit 38. It is presumed that this is due to the movement of

In FIG. 5, when the mask cleaner 33 moves to the stop position, the controller C lowers the mask cleaner 33 to separate the blade 35 from the lower surface 11b of the mask 11 and moves the mask cleaner 33 to the start position (ST4: second start position movement step). Next, the controller C raises the mask cleaner 33 to bring the blade 35 (mask cleaner 33 ) into contact with the lower surface 11 b of the mask 11 . Next, the controller C causes the mask cleaner 33 to move along the lower surface 11b of the mask 11 while stopping the suction by the suction unit 38 (FIG. 6(c)).

That is, the mask cleaner 33 removes the paste P adhering to the lower surface 11b of the mask 11 while stopping the suction by the suction unit 38 (ST5: second cleaning step). In FIG. 6C, the remaining paste P that could not be removed by the first cleaning operation is scraped off by the plurality of blades 35 by the second cleaning operation, thereby removing the mask 11 near the pattern hole 11a. It is removed from the lower surface 11b (area indicated by dashed line e). By performing the second cleaning operation after the first cleaning operation in this manner, the paste P can be removed from the lower surface 11b of the mask 11 more reliably.

In FIG. 5, when the mask cleaner 33 moves to the stop position, the controller C lowers the mask cleaner 33 to separate the blade 35 from the lower surface 11b of the mask 11 and move the mask cleaner 33 to the standby position (ST6: standby position). transfer process). This completes a series of mask cleaning (ST2 to ST6), and then returns to the printing step (ST1) to start screen printing on the next substrate 9. FIG.

Thus, between the printing step (ST1) and the next printing step (ST1) (between the printing steps), after the first cleaning step (ST3) is performed, the second cleaning step (ST5) is performed. executed. That is, the controller C causes the second cleaning operation to be executed after executing the first cleaning operation. In addition, the controller C controls the moving speed (first moving speed v1) of the mask cleaner 33 in the first cleaning operation (first cleaning process) so that the moving speed (first moving speed v1) of the mask cleaner 33 in the second cleaning operation (second cleaning process) It is controlled to be slower than the moving speed of the cleaner 33 (second moving speed v2).

As a result, the paste P adhering to the inside of the pattern hole 11a can be reliably sucked in the first cleaning operation. In the second cleaning operation, by increasing the moving speed of the mask cleaner 33, the mask cleaning execution time can be shortened. The first moving speed v1 and the second moving speed v2 can be freely set according to the shape of the pattern hole 11a, the state of the paste P, the degree of adhesion to the mask 11, and the like.

In the mask cleaning method described above, the first cleaning step (ST3) and the second cleaning step (ST5) are each performed once, but the number of cleaning steps is limited to this. no. For example, the second cleaning step (ST5) may be performed once after the first cleaning step (ST3) is performed twice. Alternatively, the first cleaning step (ST3), the second cleaning step (ST5), the first cleaning step (ST3), the second cleaning step (ST5), and the cleaning step may be performed four times.

In either method, the second cleaning step (ST5) is performed as the last cleaning step of mask cleaning, that is, the cleaning step immediately before proceeding to the next printing step (ST1). As a result, the paste P can be more reliably removed from the lower surface 11b of the mask 11, and the quality of screen printing can be improved.

As described above, the screen printing apparatus 1 of the present embodiment includes the mask 11 in which the pattern holes 11a are formed, and the paste P slid on the mask 11 and supplied onto the mask 11 through the pattern holes 11a. A squeegee 23 for printing on the substrate 9 positioned on the lower surface 11b of the mask 11, a mask cleaner 33 for removing the paste P adhering to the lower surface 11b of the mask 11, and a A suction unit 38 for sucking the adhered paste P and a mask cleaner 33 are brought into contact with the lower surface 11b of the mask 11, and the mask cleaner 33 is moved along the lower surface 11b of the mask 11 while being sucked by the suction unit 38. A cleaning operation and a second cleaning operation of moving the mask cleaner 33 along the lower surface 11b of the mask 11 while the mask cleaner 33 is brought into contact with the lower surface 11b of the mask 11 and the suction by the suction unit 38 is stopped are performed. and a control unit C for causing the

As a result, the paste P adhering to the inside of the pattern holes 11a of the mask 11 and the lower surface 11b of the mask 11 can be removed more reliably.

INDUSTRIAL APPLICABILITY The screen printing apparatus and screen printing method of the present invention have the effect of being able to more reliably remove paste adhering to a mask, and are useful in the field of mounting components on substrates.

REFERENCE SIGNS LIST 1 screen printer 9 substrate 11 mask 11a pattern hole 11b lower surface 23 squeegee 33 mask cleaner 35 blade 38 suction unit C control unit P paste S space v1 first moving speed (moving speed of mask cleaner in first cleaning operation)
v2 second moving speed (moving speed of mask cleaner in second cleaning operation)
θ Attack angle (the angle between the bottom surface of the mask and the surface of the blade that scrapes off the paste)

Claims (5)

a mask in which pattern holes are formed;
a squeegee that slides on the mask and prints the paste supplied on the mask onto a substrate positioned on the lower surface of the mask through the pattern holes;
a mask cleaner for removing paste adhered to the lower surface of the mask;
a suction unit for sucking the paste adhering to the mask when the mask cleaner removes the paste;
a first cleaning operation in which the mask cleaner is brought into contact with the lower surface of the mask and moved along the lower surface of the mask while being sucked by the suction unit; a control unit for executing a second cleaning operation in which the mask is moved along the lower surface of the mask while the suction by the suction unit is stopped;
The control unit causes the second cleaning operation to be executed after executing the first cleaning operation ,
The mask cleaner has a plurality of blades arranged side by side in the moving direction and extending in a horizontal direction intersecting the moving direction of the mask cleaner for scraping off the paste by contacting the lower surface of the mask,
The screen printing apparatus , wherein the suction unit sucks the paste from a plurality of spaces sandwiched by the blades . 2. The screen printing apparatus according to claim 1 , wherein the angle formed by the lower surface of the mask and the surface of the blade for scraping off the paste is an acute angle. 3. The screen printing apparatus according to claim 1, wherein the moving speed of said mask cleaner in said first cleaning operation is slower than the moving speed of said mask cleaner in said second cleaning operation. a mask in which pattern holes are formed; a squeegee that slides on the mask to print the paste supplied on the mask onto a substrate positioned on the lower surface of the mask through the pattern holes; A screen printing method in a screen printing apparatus comprising a mask cleaner for removing adhered paste and a suction unit for sucking the paste adhered to the mask when the mask cleaner removes the paste,
a printing step of moving the squeegee on the mask to print the paste on the substrate through the pattern holes;
a first cleaning step of bringing the mask cleaner into contact with the lower surface of the mask and removing the paste adhering to the lower surface of the mask with the mask cleaner while sucking with the suction unit;
a second cleaning step of bringing the mask cleaner into contact with the lower surface of the mask and removing paste adhering to the lower surface of the mask with the mask cleaner in a state in which suction by the suction unit is stopped;
Between the printing step and the next printing step, after performing the first cleaning step, the second cleaning step is performed ,
The mask cleaner has a plurality of blades arranged side by side in the moving direction and extending in a horizontal direction intersecting the moving direction of the mask cleaner for scraping off the paste by contacting the lower surface of the mask,
The screen printing method , wherein the suction unit sucks the paste from a plurality of spaces sandwiched by the blades . 5. The screen printing method according to claim 4 , wherein the moving speed of said mask cleaner in said first cleaning step is slower than the moving speed of said mask cleaner in said second cleaning step.

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