JP4561682B2 - Screen printing device - Google Patents

Description

  The present invention relates to a screen printing apparatus that prints paste such as cream solder or conductive paste on a substrate.

  In an electronic component mounting process, screen printing is used as a method for printing paste such as cream solder or conductive paste on a substrate. In this method, a mask plate provided with a pattern hole according to a printing target part is brought into contact with the substrate, a paste is supplied onto the mask plate, and a squeegee is slid on the substrate through the pattern hole. The paste is printed.

  During the printing operation, cream solder that protrudes from the printed area on the substrate adheres to the lower surface of the mask plate, or cream solder that has not been completely transferred onto the substrate remains in the opening of the mask plate. Pollution occurs. Such contamination by cream solder hinders normal printing on the subsequent substrate, and therefore it is necessary to perform cleaning to remove these cream solders.

For this reason, conventionally, a screen printing apparatus having a cleaning mechanism for removing residual cream solder by wiping the mask plate from the lower surface side using a dedicated cleaning paper is known (for example, see Patent Document 1). In this cleaning mechanism, the cleaning paper drawn from the paper roll is guided to the mask pressing surface of the cleaning head. In this state, the cleaning head is raised to press the cleaning paper against the lower surface of the mask plate, and then the cleaning head is moved horizontally to clean the lower surface of the mask plate with the cleaning paper.
JP 2001-287345 A

  By the way, in the cleaning operation in which the cleaning head in a state where the cleaning paper is pressed against the mask plate as described above is moved horizontally, the cleaning head and the mask plate do not move completely together due to friction between the cleaning paper and the mask plate. Paper may be slack. When such slack occurs, the dirt on the mask plate cannot be wiped off normally. Therefore, the cleaning mechanism is provided with a paper fixing mechanism that fixes the horizontal movement of the cleaning paper and prevents slack.

  As this paper fixing mechanism, there is a method of mechanically fixing a supply shaft / collection shaft connected to a paper tube of a paper roll in a cleaning paper supply / recovery mechanism by a detachable rotation prevention mechanism such as an electromagnetic brake. It was used. This complicates the structure of the paper supply / recovery mechanism and increases the equipment cost.

  SUMMARY An advantage of some aspects of the invention is that it provides a screen printing apparatus capable of simplifying the structure of a paper supply / recovery mechanism that supplies and recovers cleaning paper.

The screen printing apparatus of the present invention is a screen printing for printing a paste on a substrate through the pattern hole by bringing the substrate into contact with a mask plate provided with a pattern hole and sliding a squeegee on the mask plate. And a cleaning mechanism for cleaning the mask plate from the lower surface side by pressing and wiping the cleaning paper against the lower surface of the mask plate by a cleaning head, wherein the cleaning mechanism Paper supply / collection means for supplying cleaning paper to the cleaning head and collecting cleaning paper after use; head lifting / lowering means for raising and lowering the cleaning head in an oblique direction having a predetermined elevation angle with respect to the horizontal direction; The cleaning head The cleaning head moving means that horizontally moves together with the paper supply / collection means and the head elevating means, and the cleaning head that moves integrally with the cleaning head and the first clamp surface provided on the cleaning head. A clamp member provided with a second clamp surface that sandwiches the paper, and the cleaning head is lowered in the direction to separate the first clamp surface from the second clamp surface in the elevation direction The cleaning paper is set on the cleaning head, and when the cleaning paper is set on the cleaning head, the cleaning head is lifted in the direction so that the first clamping surface and the second clamping surface Insert the cleaning paper in between A constant.

  According to the present invention, the cleaning head includes the clamp member provided with the second clamp surface that moves integrally with the cleaning head and sandwiches the cleaning paper with the first clamp surface provided on the cleaning head. The cleaning paper is set on the cleaning head in a state where the first clamping surface is separated from the second clamping surface in the oblique direction by lowering in a diagonal direction, and the cleaning head is set in the state where the cleaning paper is set on the cleaning head. A paper supply / recovery mechanism that supplies and recovers cleaning paper by adopting a configuration in which the cleaning paper is sandwiched and fixed between the first clamp surface and the second clamp surface by raising the angle in a slanting direction. Simplifies the structure and cleans the cleaning paper. It is possible to improve the workability in setting the training head.

  Next, embodiments of the present invention will be described with reference to the drawings. 1 is a side view of a screen printing apparatus according to an embodiment of the present invention, FIG. 2 is a front view of the screen printing apparatus according to an embodiment of the present invention, and FIG. 3 is a screen printing apparatus according to an embodiment of the present invention. FIG. 4 is a diagram illustrating the operation of the screen printing apparatus according to the embodiment of the present invention. FIG. 5 is a diagram illustrating the structure of the cleaning unit of the screen printing apparatus according to the embodiment of the present invention. FIG. 7 is an explanatory view of the operation state of the cleaning unit of the screen printing apparatus according to the embodiment, FIG. 7 is an explanatory view of the tape mounting state in the cleaning unit of the screen printing apparatus according to the embodiment of the invention, and FIG. It is shape explanatory drawing of the clamp surface in the cleaning unit of the screen printing apparatus of the form.

  First, the structure of the screen printing apparatus will be described with reference to FIG. 1, FIG. 2, and FIG. In FIG. 1, the screen printing apparatus is configured by disposing a screen printing mechanism above a substrate positioning unit 1. The substrate positioning unit 1 is configured by stacking a Y-axis table 2, an X-axis table 3, and a θ-axis table 4, and further combining a first Z-axis table 5 and a second Z-axis table 6 thereon. Yes.

  The configuration of the first Z-axis table 5 will be described. Similarly, on the upper surface side of the horizontal base plate 4 a provided on the upper surface of the θ-axis table 4, the horizontal base plate 5 a is held up and down by an elevating guide mechanism (not shown). The base plate 5a is moved up and down by a Z-axis lifting mechanism configured to rotationally drive a plurality of feed screws 5c through a belt 5d by a motor 5b.

  A vertical frame 5e is erected on the base plate 5a, and a substrate transport mechanism 8 is held at the upper end of the vertical frame 5e. The substrate transport mechanism 8 includes two transport rails arranged in parallel to the substrate transport direction (X direction—the direction perpendicular to the paper surface in FIG. 1), and both end portions of the substrate 10 to be printed by these transport rails. It supports and conveys. By driving the first Z-axis table 5, the substrate 10 held by the substrate transport mechanism 8 can be lifted and lowered with respect to the screen printing mechanism described later together with the transport rail 8. As shown in FIGS. 2 and 3, the substrate transport mechanism 8 extends to the upstream side (left side in FIGS. 2 and 3) and the downstream side, and the substrate 10 carried from the upstream side is transported by the substrate transport mechanism 8. Further, the substrate is positioned by the substrate positioning unit 1. Then, the substrate 10 after being printed by a screen printing mechanism described later is carried out downstream by the transport rail 8.

  The configuration of the second Z-axis table 6 will be described. A horizontal base plate 6a is disposed between the substrate transport mechanism 8 and the base plate 5a so as to be movable up and down along a lifting guide mechanism (not shown). The base plate 6a is moved up and down by a Z-axis lifting mechanism configured to rotationally drive a plurality of feed screws 6c through a belt 6d by a motor 6b. On the upper surface of the base plate 6a, there is disposed a substrate lower receiving portion 7 having a lower receiving surface for holding the substrate 10 on the upper surface.

  By driving the second Z-axis table 6, the substrate receiving unit 7 moves up and down with respect to the substrate 10 held by the substrate transport mechanism 8. The substrate receiving portion 7 supports the substrate 10 from the lower surface side when the lower receiving surface of the substrate lower receiving portion 7 contacts the lower surface of the substrate 10. A clamp mechanism 9 is disposed on the upper surface of the substrate transport mechanism 8. The clamp mechanism 9 includes two clamp members 9a that are arranged opposite to each other on the left and right sides, and the substrate 10 is clamped and fixed from both sides by moving the clamp member 9a on one side forward and backward by the drive mechanism 9b.

  Next, the screen printing mechanism disposed above the substrate positioning unit 1 will be described. 1 and 2, a mask plate 12 is extended on the mask frame 11, and the mask plate 12 corresponds to the shape and position of the electrode 10a to be printed on the substrate 10 (see FIG. 3). Pattern holes 12a are provided. A squeegee head 13 is disposed on the mask plate 12. The squeegee head 13 has a configuration in which a squeegee raising / lowering mechanism 15 for raising and lowering the squeegee 16 is disposed on a horizontal plate 14. By driving the squeegee lifting mechanism 15, the squeegee 16 moves up and down and comes into contact with the upper surface of the mask plate 12.

  As shown in FIG. 2, a guide rail 27 is disposed in the Y direction on a bracket 26 disposed on the vertical frame 25, and a slider 28 slidably fitted on the guide rail 27 is provided on the plate 14. Connected to both ends. Thereby, the squeegee head 13 is slidable in the Y direction. The plate 14 is horizontally moved in the Y direction by a squeegee moving means comprising a nut 30, a feed screw 29, and a squeegee moving motor (not shown) that rotationally drives the feed screw 29.

  Next, a cleaning mechanism for cleaning the lower surface of the mask plate 12 will be described. As shown in FIG. 1, in the present embodiment, the cleaning head unit 18 is configured to move integrally with the camera head unit 17 that images the substrate 10 and the mask plate 12. The camera head unit 17 includes a substrate recognition camera 17a for imaging the substrate 10 from above and a mask recognition camera 17b for imaging the mask plate 12 from the lower surface side, and moves the camera head unit 17. Thus, the recognition of the substrate 10 and the recognition of the mask plate 12 can be performed simultaneously.

As shown in FIG. 3, the cleaning head unit 18 includes a paper roll 22A in which unused cleaning paper is wound around a horizontal unit base 18a, a paper roll 22B in which used cleaning paper is wound, and a cleaning head 21. The cleaning paper drawn from the paper roll 22 </ b> A is collected by the paper roll 22 </ b> B via the cleaning head 21. The camera head unit 17 and the cleaning head unit 18 are mounted on the head X-axis table 19 and move integrally in the Y direction.

  In FIG. 2, a guide rail 31 is disposed on the vertical frame 25 in the Y direction, and a slider 32 slidably fitted to the guide rail 31 is coupled to the head X-axis table 19 via a bracket 19a. Yes. As a result, the head X-axis table 19 is slidable in the Y direction. The head X-axis table 19 is horizontally moved in the Y direction by a head Y-axis moving mechanism 20 including a nut 34, a feed screw 33, and a head moving motor (not shown) that rotationally drives the feed screw 33. The head X-axis table 19 and the head Y-axis moving mechanism 20 constitute a head moving unit that horizontally moves the camera head unit 17 and the cleaning head unit 18 integrally.

  When the substrate 10 and the mask plate 12 are not recognized by the camera head unit 17 and the mask cleaning by the cleaning head unit 18 is not performed, the camera head unit 17 and the cleaning head unit 18 are as shown in FIG. Both are retracted from the upper side of the substrate positioning unit 1 to the side. Then, when performing mask cleaning, the cleaning head unit 18 is moved downward together with the camera head unit 17 below the mask plate 12, and then the cleaning head 21 is raised. Then, with the cleaning paper 21 pressed against the lower surface of the mask plate 12 by the cleaning head 21, the cleaning head unit 18 is moved horizontally to wipe off the lower surface of the cleaning head 21 for cleaning.

  Accordingly, the cleaning head unit 18 and the head moving means for moving the cleaning head unit 18 press the cleaning paper 23 supplied in a paper roll wound around the paper tube against the lower surface of the mask plate 12 by the cleaning head 21. A cleaning mechanism for cleaning the mask plate 12 from the lower surface side is formed by wiping.

  Next, the printing operation by the screen printing mechanism will be described. First, when the substrate 10 is carried into the printing position by the substrate transport mechanism 8, the second Z-axis table 6 is driven to raise the substrate receiving portion 7 and receive the lower surface of the substrate 10. In this state, the substrate positioning unit 1 is driven to align the substrate 10 with the mask plate 12. Thereafter, the first Z-axis table 5 is driven to raise the substrate 10 together with the substrate transport mechanism 8 to contact the lower surface of the mask plate 12, and then the substrate 10 is clamped by the clamp mechanism 9. Thereby, the horizontal position of the board | substrate 10 is fixed in the squeegeeing by the squeegee unit 13. In this state, the squeegee 16 is slid on the mask plate 12 to which the cream solder as paste is supplied, whereby the cream solder is printed on the substrate 10 through the pattern holes 12a.

  Next, the structure of the cleaning head unit 18 will be described with reference to FIGS. FIG. 5B shows a cross section in the Y direction of the cleaning head unit 18 shown in FIG. Roll support shafts 40A and 40B penetrating the paper rolls 22A and 22B are supported on the support brackets 18b and 18c provided upright on the unit base 18a. An elongate cleaning head 21 is disposed on the side of the paper roll 22B. A clamp member 38 is provided on the side of the cleaning head 21 along the longitudinal direction of the cleaning head 21.

  A motor 41 is disposed on the support bracket 18c at a position coaxial with the roll support shaft 40B. A rotation shaft of the motor 41 is coupled to the roll support shaft 40B via a coupling member 42. By driving the motor 41, the roll support shaft 40B rotates in the winding direction, and the cleaning paper 23 is wound around the paper roll 22B. As a result, the cleaning paper 23 is pulled out from the paper roll 22A, and the pulled-out cleaning paper 23 is guided by the guide roller 37, circulates around the cleaning head 21, and is collected by the paper roll 22B.

  As shown in FIG. 5B, a coupling block 36 is coupled to the lower surface of the cleaning head 21, and the coupling block 36 is coupled to a lifting rod 35a of a head lifting mechanism 35 (head lifting means). . The head elevating mechanism 35 is disposed in the oblique direction (arrow a) that forms a predetermined elevation angle θ (about 45 ° in this case) with respect to the horizontal direction, and the head elevating mechanism 35 is driven to drive the head elevating mechanism 35. The cleaning head 21 moves up and down in an oblique direction indicated by an arrow a. That is, the head elevating mechanism 35 is a head elevating unit that elevates and lowers the cleaning head 21 in an oblique direction having a predetermined elevation angle with respect to the horizontal direction. The predetermined elevation angle θ described above is not limited to 45 °, and an appropriate angle may be selected as appropriate on the component layout in the cleaning head unit 18.

  In the normal state shown in FIG. 5B, the cleaning head 21 is in the lowered state. At the time of mask cleaning for cleaning the lower surface of the mask plate 12, as shown in FIG. 6, the head lifting mechanism 35 is driven to raise the cleaning head 21 in the above-described oblique direction, so that the cleaning paper 23 is placed on the lower surface of the mask plate 12. Press.

  The cleaning head 21 has a shape having an upper portion 21a provided with a pressing surface and a base portion 21b having a larger lateral dimension than the upper portion 21a and coupled to the coupling block 36. The upper surface of the base 21b functions as a first clamping surface 21c that sandwiches and clamps the cleaning paper 23 as described below. The cross section of the clamp member 38 has an inverted L shape having an extending portion 38a extending above the first clamp surface 21c, and faces the first clamp surface 21c when the cleaning head 21 is raised. The lower surface of the extending portion 38a is a second clamp surface 38b that sandwiches the cleaning paper 23 with the first clamp surface 21c.

  As shown in FIG. 6, in a state where the head elevating mechanism 35 is driven to raise the elevating rod 35 a together with the cleaning head 21 and the cleaning paper 23 is pressed against the lower surface of the mask plate 12, the cleaning paper 23 circulates around the cleaning head 21. Is sandwiched between the first clamping surface 21c and the second clamping surface 38b, and the position in the paper feed direction is fixed. At this time, the rotation of the paper roll 22B that winds up the cleaning paper 23 is locked by the position holding action of the motor 41. Therefore, the cleaning paper 23 is locked from moving in the direction opposite to the winding direction by the paper roll 22B. Is in a state.

  Accordingly, in the cleaning operation in which the cleaning head 21 is moved relative to the mask plate 12 while pressing the cleaning paper 23 against the mask plate 12, the cleaning paper 23 moves completely integrally with the cleaning head 21. That is, when the cleaning head unit 18 moves in the direction of the arrow b, the cleaning paper 23 is sandwiched between the first clamp surface 21c and the second clamp surface 38b, and the cleaning head unit 18 is moved to the arrow b direction. When moving in the direction c, the rotation of the paper roll 22B is locked, so that the cleaning paper 23 moves relative to the cleaning head 21 due to the frictional force with the mask plate 12. The slack does not occur.

  In the above configuration, the roll support shaft 40A that is pivotally supported by the support brackets 18b and 18c is a first roll mounting portion on which the unused paper roll 22A is rotatably mounted around the paper tube axis. The roll support shaft 40B pivotally supported by the support brackets 18b and 18c has a second paper roll 22B on which the used cleaning paper 23 is wound around the paper tube and collected so as to be rotatable around the paper tube shaft. It is a roll mounting part.

  The first roll mounting portion, the second roll mounting portion, and the motor 41 constitute a paper supply / recovery unit that supplies unused cleaning paper 23 to the cleaning head 21 and collects cleaning paper after use. . Further, the head moving means for horizontally moving the camera head unit 17 and the cleaning head unit 18 integrally is configured to horizontally move the cleaning head 21 together with the paper supply / recovery means and the head lifting / lowering means.

  That is, the screen printing apparatus shown in the present embodiment moves together with the cleaning head 21, and the second clamping surface sandwiches the cleaning paper 23 between the first clamping surface 21 c provided on the cleaning head 21. The clamp member 38 provided with 38b is provided. Then, in a state where the cleaning paper 23 is set on the cleaning head 21, the cleaning head 21 is lifted in an oblique direction (arrow a) shown in FIG. The cleaning paper 23 is sandwiched between the surface 38b and fixed.

  FIG. 7A shows a state in which a new paper roll 22 </ b> A is attached and the leading end of the cleaning paper 23 is set on the cleaning head 21 in the cleaning head unit 18 described above. FIG. 7B also shows an example of a cleaning head unit 18A of the type in which the cleaning head 21 is lifted and lowered in the vertical direction (arrow d) in the configuration in which the cleaning paper 23 is sandwiched and fixed by the cleaning head 21 and the clamp member 38. Is shown for comparison.

  As shown in FIG. 7A, when the cleaning paper 23 is set, the head lifting mechanism 35 is driven to lower the cleaning head 21 in the above-described oblique direction, so that the first clamping surface 21c is moved to the second clamping surface. The cleaning paper 23 is set on the cleaning head 21 in a state in which the clearance C1 for guiding the cleaning paper 23 is provided between the upper portion 21a and the clamp member 38 in an oblique direction away from 38b.

  At this time, since the cleaning head 21 moves in a downwardly inclined direction from the clamp member 38 in the lowered state, the allowable clearance C1 for setting the cleaning paper 23 is an example shown in FIG. That is, it is larger than the clearance C2 allowed when the head lifting mechanism 35 for raising and lowering the cleaning head 21 is arranged in the vertical direction, and the cleaning paper 23 can be easily set.

  As a result, the paper fixing mechanism used in the conventional device, that is, the cleaning paper supply / recovery mechanism, mechanically fixes the supply shaft / collection shaft coupled to the paper roll paper tube by a rotation prevention mechanism such as an electromagnetic brake. The cleaning paper can be fixed with an extremely simple mechanism compared to the method to do this, and the equipment cost can be reduced, and the workability when setting the cleaning paper on the cleaning head is improved. Can do.

In the above-described example, the first clamping surface 21c and the second clamping surface 38b are both horizontal surfaces, and when clamping the cleaning paper 23, the clamping surfaces are opposed to each other up and down. The shape and the sandwiching direction of the cleaning paper 23 are not limited to this. For example, the cleaning head 121 and the clamp member 138 as shown in FIG. 8 may be combined.

  The cleaning head 121 shown in FIG. 8A cuts the corner portion on the upper left side at the base 121b corresponding to the base 21b of the cleaning head 21, and moves up and down the cleaning head 121 (as in FIG. 5B). The first clamp surface 121c is provided in a direction orthogonal to the oblique direction (arrow a). In addition, the clamp member 138 cuts a corner portion on the right lower end side in the extended portion 138a corresponding to the extended portion 38a of the clamp member 38, and the second clamp surface in a direction facing the first clamp surface 121c. 138b is provided. As shown in FIG. 8B, when the cleaning paper 121 is set and the cleaning head 121 is raised in an oblique direction, the cleaning paper 23 is moved by the first clamp surface 121c and the second clamp surface 138b. It is caught.

  The screen printing apparatus of the present invention has an effect of simplifying the structure of a paper supply / recovery mechanism that supplies and recovers cleaning paper, and prints paste such as cream solder and conductive paste on a substrate. Useful in the field of screen printing.

The side view of the screen printing apparatus of one embodiment of this invention 1 is a front view of a screen printing apparatus according to an embodiment of the present invention. The top view of the screen printing apparatus of one embodiment of this invention Operation explanatory diagram of a screen printing apparatus according to an embodiment of the present invention Structure explanatory drawing of the cleaning unit of the screen printing apparatus of one embodiment of the present invention Explanatory drawing of operation | movement of the cleaning unit of the screen printing apparatus of one embodiment of this invention Explanatory drawing of the tape mounting state in the cleaning unit of the screen printing apparatus of one embodiment of this invention Shape explanatory drawing of the clamp surface in the cleaning unit of the screen printing apparatus of one embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate positioning part 10 Substrate 12 Mask plate 12a Pattern hole 13 Squeegee unit 16 Squeegee 18 Cleaning head unit 19 Head X axis table 20 Head Y axis moving mechanism 21 Cleaning head 21c First clamp surface 22A, 22B Paper roll 23 Cleaning paper 35 Head lifting mechanism 38 Clamp member 38b Second clamp surface 40A, 40B Roll support shaft 41 Motor

Claims (1)

A screen printing unit that prints paste on the substrate through the pattern hole by bringing the substrate into contact with the mask plate provided with the pattern hole and sliding a squeegee on the mask plate, and a cleaning head with the cleaning paper A screen printing apparatus having a cleaning mechanism for cleaning the mask plate from the lower surface side by wiping it against the lower surface of the mask plate by
The cleaning mechanism includes a paper supply / collection means for supplying the unused cleaning paper to the cleaning head and recovering the used cleaning paper, and an oblique angle that forms a predetermined elevation angle with respect to the horizontal direction of the cleaning head. A head raising / lowering means for raising and lowering in the direction, a cleaning head moving means for moving the cleaning head horizontally together with the paper supply / recovery means and the head raising / lowering means, and a cleaning head moving means that moves integrally with the cleaning head. A clamp member provided with a second clamp surface for sandwiching the cleaning paper between the first clamp surface and the first clamp surface,
The cleaning paper is set on the cleaning head in a state where the cleaning head is lowered in the oblique direction and the first clamping surface is separated from the second clamping surface in the oblique direction,
The cleaning paper is sandwiched and fixed between the first clamp surface and the second clamp surface by raising the cleaning head in the oblique direction with the cleaning paper set on the cleaning head. A screen printing device.

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