JP5906386B2 - Screen printing machine and screen printing method - Google Patents

Description

  The present invention relates to a screen printer and a screen printer method for transferring a paste to a substrate by sliding a squeegee on the mask in contact with the substrate and scraping the paste on the mask.

  The screen printing machine makes the squeegee contact the mask that is in contact with the substrate and moves it horizontally, and slides the squeegee on the mask to scrape the paste on the mask, thereby opening the opening provided in the mask. The paste is filled with paste to transfer the paste to the substrate. In such a screen printing machine, the squeegee that has finished transferring the paste is normally stopped moving in the horizontal direction while being in contact with the mask, and then lifted and separated from the mask. However, since the paste has a characteristic that the viscosity is low during rolling but becomes high during non-rolling, if the squeegee is raised after stopping the horizontal movement, the squeegee will finish rolling and increase in viscosity. Part of the paste is pulled up, and the paste is tapered upward and falls down in the moving direction of the squeegee at the next sliding of the squeegee, and air is entrained. Then, bubbles are included in the paste being rolled, and the filling state of the paste in the opening of the mask is deteriorated, and printing failure is likely to occur. Conventionally, the squeegee that has stopped moving in the horizontal direction has been conventionally used. 2. Description of the Related Art A screen printing machine is known that regulates the movement speed (separation speed) of a squeegee when raising the squeegee with respect to the mask, and prevents the paste from collapsing to prevent air entrainment (for example, Patent Documents) 1).

JP 2008-119851 A

  However, even in the above-described conventional screen printing machine, the squeegee is lifted after stopping on the mask, so that the amount of paste that is attached to the squeegee and pulled up is large, and air entrainment occurs due to the collapse of the paste. As a result, there is a problem that printing accuracy may be lowered.

  Therefore, the present invention provides a screen printing machine and a screen printing method in which it is difficult for the paste pulled up when the squeegee is separated from the mask to collapse when the squeegee slides and the air is trapped. Objective.

  The screen printing machine according to claim 1, wherein a squeegee is brought into contact with the mask in contact with the substrate, the squeegee is brought into contact with the mask and moved in the horizontal direction, and the squeegee is slid on the mask. And a squeegee movement control unit for transferring the paste to the substrate by filling the opening in the mask with the paste by scraping the paste on the mask. The squeegee is lifted with respect to the mask during the horizontal movement of the squeegee relative to the mask, and the horizontal movement of the squeegee is stopped while being separated from the mask.

  The screen printing machine according to claim 2 is the screen printing machine according to claim 1, wherein the squeegee movement control unit moves the squeegee horizontally until it stops immediately after the horizontal movement of the squeegee is stopped. The squeegee is moved in a direction opposite to the direction in which it has been moved.

  The screen printing method according to claim 3, wherein a mask contact step of bringing a mask into contact with a substrate, a squeegee is brought into contact with the mask in contact with the substrate and moved in a horizontal direction, and the squeegee is moved on the mask. A paste transfer step of transferring the paste to the substrate by filling the opening provided in the mask by sliding and scraping the paste on the mask, and in the paste transfer step The squeegee is raised with respect to the mask during the horizontal movement of the squeegee with respect to the mask, and the horizontal movement of the squeegee is stopped while being separated from the mask.

  The screen printing method according to claim 4 is the screen printing method according to claim 3, wherein in the paste transfer step, the horizontal movement of the squeegee is continued until immediately after the horizontal movement of the squeegee is stopped. The squeegee is moved in a direction opposite to the direction.

  In the present invention, the squeegee is lifted with respect to the mask during the horizontal movement of the squeegee with respect to the mask, and the horizontal movement of the squeegee is stopped while being separated from the mask, so that the viscosity of the paste is low. Since the squeegee is lifted with respect to the mask during rolling, the amount of paste pulled up when the squeegee is separated from the mask can be reduced. For this reason, it is difficult for the paste pulled up when the squeegee is separated from the mask to fall down when the squeegee slides and the air is trapped, thereby preventing the printing accuracy from being lowered.

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 screen operation | work which the screen printer in one embodiment of this invention performs (A) (b) Operation | movement explanatory drawing of the screen printer in one embodiment of this invention (A) (b) Operation | movement explanatory drawing of the screen printer in one embodiment of this invention (A) (b) Operation | movement explanatory drawing of the screen printer in one embodiment of this invention The enlarged view of the squeegee in the state in which the screen printer in one embodiment of this invention is performing screen printing work The enlarged view of the squeegee in the state in which the screen printer in one embodiment of this invention is performing screen printing work (A) (b) Operation | movement explanatory drawing of the screen printer in one embodiment of this invention

  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 installed in a component mounting system for mounting components on a substrate 2 and screen-prints a paste Ps such as solder on an electrode portion 2a of the substrate 2 (screen printing operation). ), 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 installed above the substrate holding unit 12, A mask 14 held in a horizontal posture by a mask holder 13, a camera unit 15 provided movably below the mask 14, and a squeegee unit 16 provided movably above the area above the mask 14 are provided. In the following description, the transport direction of the substrate 2 is defined as the X-axis direction (left-right direction viewed from the operator OP), and the horizontal plane direction orthogonal to the X-axis is defined as the Y-axis direction (front-rear 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 made of a thin plate made of a thin metal and has a large number of openings 14 h corresponding to the electrode portions 2 a of the substrate 2, and a rectangular mask frame 14 w provided on the outer edge is a mask holder 13. Is supported by.

  In FIG. 1, two substrate side marks 2m are provided at one diagonal position on the substrate 2, and the mask 14 is provided with two mask side marks 14m corresponding to the two substrate side marks 2m. It has been. When the substrate 2 is raised with the two substrate-side marks 2m and the two mask-side marks 14m opposed to each other and the substrate 2 is brought into contact with the mask 14, the electrodes 2a of the substrate 2 and the mask 14 are provided. The opening 14h is in a matched state.

  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 receiving conveyor 12b and a substrate receiving cylinder 12d and a substrate lifting cylinder 12d for raising and lowering the substrate 2 by raising and lowering the lower receiving member 12c positioned below the substrate 2 positioned at a predetermined substrate holding position. And a pair of clamp members 12e for clamping and holding the substrate 2 pushed up by the Y-axis 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.

  1 and 2, the camera unit 15 includes a lower imaging camera 15a whose imaging field of view is directed downward, and an upper imaging camera 15b whose imaging field of view is directed upward, and is controlled by the control device 20 (not shown). It moves in the horizontal plane below the mask 14 held by the mask holder 13 by the operation of the camera unit moving mechanism 15M (FIG. 3) comprising a Cartesian coordinate robot.

  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 includes a base portion 16a and a base portion 16a that are movable in the Y-axis direction above the mask 14 by operation of a squeegee unit moving mechanism 16A (FIG. 3) that is an unillustrated rectangular coordinate robot. Are provided with two squeegees 16b provided facing each other in the Y-axis direction, and each squeegee 16b is independently below the base portion 16a by two pneumatic cylinders 16c attached to the base portion 16a. Is to be lifted and lowered. 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, a paste supply syringe 16 d that discharges the paste Ps from a discharge port directed downward is provided at the rear end of the base portion 16 a of the squeegee unit 16. The supply control of the paste Ps by the paste supply syringe 16d is performed when the control device 20 controls the operation of the paste discharge mechanism 16B including an actuator (not shown) (FIG. 3).

  The control device 20 lowers the squeegee 16b on the rear side from the state positioned above the clamp member 12e on the rear side and brings it into contact with the mask 14, and then moves the base portion 16a from the rear toward the front. In this manner, the squeegee 16b on the rear side is moved to the upper side of the clamp member 12e on the front side while sliding the squeegee 16b on the rear side to the upper side of the clamp member 12e on the front side. After being lowered from the state positioned above 12e and brought into contact with the mask 14, the squeegee 16b on the front side is slid on the mask 14 by moving the base portion 16a from the front toward the rear. "Squeezing by the front squeegee 16b" for moving the upper side of the clamp member 12e on the rear side is executed alternately.

  Next, the execution procedure of the screen printing operation (screen printing method) performed by the screen printer 1 will be described with reference to the flowchart of FIG. 4 and the explanatory diagrams of FIGS. 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 A1 shown in FIG. 5A) and the substrate 2 is clamped by the clamp member 12e (arrow B1 shown in FIG. 5A). Hold (step ST1 shown in FIG. 4; FIG. 5A).

  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 above the substrate-side mark 2m provided on the substrate 2. The lower imaging camera 15a captures the substrate-side mark 2m to grasp the position of the substrate 2 from the image data, and the upper imaging camera 15b is positioned below the mask-side mark 14m provided on the mask 14. Then, the upper imaging camera 15b captures the mask side mark 14m, and the position of the mask 14 is grasped from the image data. Then, the substrate holding unit 12 is moved in the horizontal plane direction, and the substrate 2 is aligned with the mask 14 in the horizontal plane direction so that the substrate side mark 2m and the mask side mark 14m face each other vertically (step ST2). ).

  When the positioning of the substrate 2 with respect to the mask 14 is finished, 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. 5B). As shown by 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 (step ST3, FIG. 5B). 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, it determines whether or not the paste Ps needs to be supplied onto the mask 14 (step ST4). As a result, the paste Ps is supplied onto the mask 14. When it is determined that it is necessary, the operation of the squeegee unit moving mechanism 16A is controlled to move the paste supply syringe 16d to a predetermined position above the mask 14, and the operation of the paste discharge mechanism 16B is controlled to perform the paste supply syringe. From 16d, the paste Ps is discharged and supplied onto the mask 14 (step ST5, FIG. 5B).

  When the control device 20 determines that it is not necessary to supply the paste Ps onto the mask 14 at step ST5 or to supply the paste Ps onto the mask 14 at step ST4, the control device 20 performs squeegeeing with the squeegee 16b and performs masking in advance. The paste Ps supplied onto 14 is transferred to the electrode portion 2a of the substrate 2 (step ST6).

  In step ST <b> 6, the control device 20 executes one of the squeegeeing by the rear squeegee 16 b and the squeezing by the front squeegee 16 b once per substrate 2. When squeezing with the squeegee 16b on the rear side, the controller 20 moves the entire squeegee unit 16 so that the squeegee 16b on the rear side is positioned above the clamp member 12e on the rear side, and then the rear side. The squeegee 16b is moved downward (arrow D1 shown in FIG. 6A), and the base portion 16a is moved forward while maintaining the state in which the rear squeegee 16b is in contact with the upper surface of the mask 14 (FIG. 6). (B) is performed by the arrow E).

  When the rear squeegee 16b reaches the upper region of the front clamp member 12e (FIG. 7A), the control device 20 raises the rear squeegee 16b and returns it to the initial position (height) ( Fig. 7B, an arrow D2 shown in the figure. By the squeegeeing (sliding on the mask 14) by the squeegee 16b on the rear side, the paste Ps is scraped from the rear side to the front side of the mask 14, and the paste Ps is filled in the opening 14h of the mask 14 in the meantime. Then, it is transferred onto the electrode portion 2a of the substrate 2.

  In the squeegeeing by the rear squeegee 16b, the squeegee 16b moves in the horizontal direction with respect to the mask 14 (however, the rear squeegee 16b passes above all the openings 14h provided in the mask 14). Thereafter, the squeegee 16b is raised with respect to the mask 14 (arrow F shown in FIG. 8), and the horizontal movement of the squeegee 16b is stopped while being separated from the mask 14 (FIG. 8). In this way, the squeegee 16b is lifted with respect to the mask 14 during rolling when the viscosity of the paste Ps is low, so that the amount of paste pulled up when the squeegee 16b is separated from the mask 14 is reduced, and the paste Ps tapers upward. Therefore, when the squeegeeing is performed by the next front squeegee 16b, it is difficult for air to be caught due to the fall of the paste Ps.

  Further, immediately after stopping the movement of the squeegee 16b in the horizontal direction, the control device 20 moves the squeegee 16b in a direction opposite to the direction in which the squeegee 16b has been moved in the horizontal direction (rearward here) (FIG. 9). The arrow G) shown in FIG. 9 makes it easy for the squeegee 16b to separate from the paste Ps on the mask 14 (FIG. 9).

  When the paste Ps is transferred to the electrode portion 2a of the substrate 2, the control device 20 operates the substrate holding unit moving mechanism 11 to lower the substrate holding unit 12 to separate the substrate 2 from the mask 14 (FIG. 10 ( The arrow C2) shown in a) is separated (step ST7, FIG. 10A). As a result, the paste Ps remains on the electrode portion 2a of the substrate 2, and the paste Ps is printed on the substrate 2.

  When the controller 20 releases the plate, the control unit 20 releases the holding of the substrate 2 by the substrate holding unit 12 (step ST8). Specifically, the release of the holding of the substrate 2 is performed after the control device 20 controls the operation of the clamp member drive mechanism 12B to open the clamp member 12e (arrow B2 shown in FIG. 10B). ), The substrate raising / lowering cylinder 12d is operated to lower the substrate 2 (arrow A2 shown in FIG. 10B), and both ends of the substrate 2 are lowered onto the pair of substrate transfer conveyors 12b (FIG. 10B). )).

  When the holding of the substrate 2 is released, the control device 20 operates the substrate transport conveyor 12b to carry the substrate 2 out of the screen printer 1 (step ST9).

  When screen printing per substrate 2 is completed in this way, the above-described steps ST1 to ST9 are executed in the same procedure for the substrate 2 that has been input next. However, this time, the paste transfer process of step ST6 is performed by squeezing with the front squeegee 16b. Thereafter, each time a new substrate 2 is inserted, squeezing with the rear squeegee 16b and front squeegee 16b are performed. Perform squeezing alternately.

  In the squeegeeing by the front squeegee 16b, as in the case of the squeegeeing by the rear squeegee 16b, the squeegee 16b on the front side is in the middle of the horizontal movement of the squeegee 16b with respect to the mask 14 (however, 14) after passing over all of the openings 14h provided in 14), the squeegee 16b is lifted with respect to the mask 14, and the horizontal movement of the squeegee 16b is stopped while being separated from the mask 14. Immediately after stopping the movement of the squeegee 16b in the horizontal direction, the squeegee 16b is moved in a direction opposite to the direction in which the squeegee 16b has been moved in the horizontal direction (here, in the front direction). The squeegee 16b is separated.

  Thus, in the present embodiment, the squeegee unit moving mechanism 16A and the control device 20 that controls the operation of the squeegee unit move the squeegee 16b in the horizontal direction by bringing the squeegee 16b into contact with the mask 14 that is in contact with the substrate 2. Then, by sliding the squeegee 16b on the mask 14 and scraping the paste Ps on the mask 14, the opening 14h provided in the mask 14 is filled with the paste Ps to transfer the paste Ps to the substrate 2. The squeegee movement control unit is configured such that the squeegee movement control unit raises the squeegee 16b with respect to the mask 14 during the horizontal movement of the squeegee 16b with respect to the mask 14 and separates the squeegee from the mask 14. The horizontal movement of 16b is stopped.

  Further, in the screen printing method by the screen printer 1 in the present embodiment, the mask contact step (step ST3) for bringing the mask 14 into contact with the substrate 2, and the squeegee 16b is brought into contact with the mask 14 brought into contact with the substrate 2. 16b is moved in the horizontal direction, and the squeegee 16b is slid on the mask 14 to scrape the paste Ps on the mask 14, thereby filling the opening 14h provided in the mask 14 with the paste Ps to the substrate 2. In the paste transfer process, the squeegee 16b is raised relative to the mask 14 in the middle of the horizontal movement of the squeegee 16b relative to the mask 14 in the paste transfer process. The horizontal movement of the squeegee 16b is stopped in a state separated from .

  In the screen printing machine 1 (screen printing method) according to the present embodiment, the squeegee 16b is lifted with respect to the mask 14 during the horizontal movement of the squeegee 16b with respect to the mask 14, and is separated from the mask 14. The horizontal movement of 16b is stopped, and the squeegee 16b is lifted with respect to the mask 14 during rolling when the viscosity of the paste Ps is low. Therefore, the amount of the paste Ps pulled up when the squeegee 16b is separated from the mask 14 is reduced. can do. For this reason, it is difficult for the paste Ps pulled up when the squeegee 16b is separated from the mask 14 to collapse when the squeegee 16b slides and entrains air, thereby preventing a decrease in printing accuracy. .

  Provided are a screen printing machine and a screen printing method in which it is difficult for the paste pulled up when the squeegee is separated from the mask to fall when the squeegee slides and the air is trapped.

DESCRIPTION OF SYMBOLS 1 Screen printer 2 Board | substrate 14 Mask 14h Opening part 16b Squeegee 16A Squeegee unit moving mechanism (squeegee movement control part)
20 Control device (squeegee movement control unit)
Ps paste

Claims (4)

A mask in contact with the substrate;
An opening provided in the mask by bringing a squeegee into contact with the mask in contact with the substrate and moving the squeegee in a horizontal direction and sliding the squeegee on the mask to scrape the paste on the mask. A squeegee movement control unit for filling the part with paste and transferring the paste to the substrate,
The squeegee movement control unit
After filling all the openings with the paste, the squeegee with respect to the mask and the squeegee are raised with respect to the mask during the horizontal movement of the paste , and in a state of being separated from the mask A screen printing machine characterized by stopping horizontal movement of a squeegee.   2. The squeegee movement control unit moves the squeegee in a direction opposite to the direction in which the squeegee has been moved in the horizontal direction immediately after the horizontal movement of the squeegee is stopped. Screen printing machine. A mask contact process for bringing the mask into contact with the substrate;
An opening provided in the mask by bringing a squeegee into contact with the mask in contact with the substrate and moving the squeegee horizontally, and sliding the squeegee on the mask to scrape the paste on the mask. Paste transfer step of filling the part with paste and transferring the paste to the substrate,
In the paste transfer step, after all the openings are filled with paste , the squeegee with respect to the mask and the squeegee are raised with respect to the mask during the horizontal movement of the paste , and separated from the mask. A screen printing method, wherein the horizontal movement of the squeegee is stopped in a state where the squeegee is moved.   4. The screen according to claim 3, wherein in the paste transfer step, immediately after the horizontal movement of the squeegee is stopped, the squeegee is moved in a direction opposite to the direction in which the squeegee has been moved in the horizontal direction. Printing method.

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