JP4566810B2 - Screen printing device - Google Patents

Description

  The present invention relates to a screen printing apparatus that applies paste such as cream solder to a substrate such as a printed circuit board.

  Conventionally, a mask sheet is overlaid on a substrate set on a stage, and a paste such as cream solder or conductive paste supplied on the mask sheet is expanded with a squeegee, thereby allowing the substrate to pass through an opening formed in the mask sheet. A screen printing apparatus configured to apply (print) a paste at a predetermined position above is generally known.

  Conventionally, such a screen printing apparatus is provided with a head that supports a pair of squeegees having different inclination directions so that the squeegee can be moved up and down individually, and the pair of squeegees are alternately moved while reciprocating along the mask sheet. The device that expands the paste by using it was the mainstream, but in this conventional device, in order to raise and lower each squeegee separately, the printing load during forward movement and the printing load during backward movement are kept uniform. And the degree of freedom of the contact angle of the squeegee with respect to the mask sheet is small.

Therefore, in recent years, as disclosed in Patent Document 1, for example, a squeegee holder that holds a pair of squeegees is provided to be rotatable (swingable) about an axis perpendicular to the moving direction of the squeegee with respect to the head. Screen printing devices have been proposed. According to this apparatus, the contact angle with respect to the mask sheet can be arbitrarily set within a predetermined range (generally about 40 ° to about 75 °) simply by driving the squeegee around the axis. Since the mechanism can drive the squeegee up and down, it is easy to keep the printing load during forward movement and the printing load during backward movement uniform.
JP-A-10-323964

  The screen printing apparatus disclosed in Patent Document 1 is advantageous in terms of the degree of freedom in setting the angle of the squeegee with respect to the mask sheet or the printing load, but has the following problems to be solved.

  That is, since the contact angle of the squeegee with respect to the mask sheet can be set within a predetermined range (about 40 ° to about 75 °), the work surface for pressing the paste of the squeegee always faces downward. Thereby, since it is difficult for an operator to visually recognize the work surface of the squeegee, it may be difficult to exchange the squeegee with respect to the head.

  Further, in the screen printing apparatus as described above, in order to avoid the paste adhering to the work surface of the squeegee from deteriorating due to contact with air for a long time when printing is interrupted, The paste needs to be removed, but since the work surface of the squeegee is always facing downward, it is difficult for the operator to visually recognize the work surface of the squeegee and it may be difficult to remove the paste on the work surface of the squeegee .

  The present invention has been made in view of the above circumstances, and in a screen printing apparatus that supports a squeegee so as to be rotatable (swingable) with respect to a head, it improves workability other than during printing, such as when changing a squeegee. The purpose is to let you.

To achieve the above object, a screen printing apparatus according to claim 1 of the present invention includes a head that supports a squeegee and relatively reciprocates the squeegee along a mask sheet superimposed on a substrate. In the screen printing apparatus in which the squeegee is provided to be rotatable about an axis perpendicular to the moving direction of the squeegee with respect to the head, the squeegee has one side as a work surface for pressing the paste, The shaft is positioned on the opposite side of the working surface with respect to the squeegee, and the working surface is inclined to one side and to the opposite side from the state facing the mask sheet in parallel to the mask sheet. Squeegee rotating means for rotating about the axis, and in the state of one edge portion of the work surface abutting the mask sheet during forward printing Also in the state at the time of backward movement of the printing the other edge portion of the work surface is brought into contact with the mask sheet is configured such that each said squeegee performing coating paste by moving the squeegee pivot means, said the angle between the mask sheet and the squeegee, with equal to or less than a predetermined value during printing, so as to exceed the predetermined value other than during printing, and wherein the benzalkonium rotates the squeegee relative to the head .

According to this screen printing apparatus, the squeegee can be rotated with respect to the head so that the angle formed between the squeegee and the mask sheet is larger than the angle at the time of printing at an appropriate time other than printing. Therefore, the work surface on which the operator presses the paste of the squeegee can be easily visually recognized other than during printing. Further, in this screen printing apparatus, printing can be performed at the time of forward movement and backward movement by one squeegee having one side as a work surface.

In the screen printing apparatus, preferably, the head is provided with a squeegee assembling portion that can be rotated about an axis orthogonal to the moving direction of the squeegee, and the squeegee is held on the rotating tip side of the squeegee assembling portion The squeegee holder is detachably assembled, and as a squeegee rotating means, the rotation drive mechanism for rotating the squeegee assembly part around the axis and the angle formed between the squeegee and the mask sheet are below a predetermined value during printing. And a control means for rotating the squeegee assembly portion with respect to the head by a rotation drive mechanism so as to exceed a predetermined value except during printing, and the rotation drive mechanism is provided on one side of the movement direction of the shaft. The squeegee is located on the other side in the movement direction except for the time of printing .

  If comprised in this way, the squeegee assembling part will be set by the rotation drive mechanism so that the angle formed between the squeegee and the mask sheet is less than or equal to a predetermined value during printing and exceeds a predetermined value other than during printing. Since it can be rotated with respect to the head, the squeegee assembling portion can be rotated with respect to the head both at the time of printing and at the time other than printing by using a single rotation driving mechanism.

  In the screen printing apparatus, preferably, the angle formed between the squeegee and the mask sheet is not more than a predetermined value smaller than 90 ° during printing and is not less than 90 ° other than during printing.

  According to this configuration, the squeegee can be rotated with respect to the head by the squeegee rotating means so that the angle formed between the squeegee and the mask sheet is 90 ° or more other than during printing. In addition, the work surface of the squeegee can be oriented more than the vertical surface.

  According to the screen printing apparatus of the present invention, since the operator can easily visually recognize the work surface of the squeegee other than during printing, the squeegee can be exchanged with respect to the head, or the paste on the work surface of the squeegee can be removed. The workability at the time of performing can be improved.

  Hereinafter, embodiments of the present invention will be described based on the drawings.

  1 and 2 are diagrams showing the overall configuration of a screen printing apparatus according to an embodiment of the present invention, and FIGS. 3 to 5 show the configuration of the head portion of the screen printing apparatus shown in FIG. FIG. 6 to 9 are schematic views showing the positional relationship between the squeegee and the mask sheet in a series of operations of the screen printing apparatus shown in FIG. First, an overall configuration of a screen printing apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  As shown in FIGS. 1 and 2, on the base 1 of the screen printing apparatus, a carry-in conveyor 2 a and a carry-out conveyor 2 b are disposed with a print stage 3 interposed therebetween, and a printed circuit board W (hereinafter referred to as “print board W”). Substrate W is abbreviated as “W” and is carried into the printing stage 3 by the carry-in conveyor 2a, and after being subjected to the printing process, it is carried out by the carry-out conveyor 2b.

  In the following description, the conveyance direction of the substrate W by these conveyors 2a and 2b is the Y-axis direction, the direction orthogonal to this on the horizontal plane is the X-axis direction, and the direction orthogonal to both the X-axis and Y-axis directions is Z. The description will proceed as an axial direction. That is, since a printed board inspection apparatus (not shown), one or a plurality of mounting machines, a mounting board inspection apparatus, and a reflow furnace are connected by a conveyor in the left direction in FIG. 2, a single mounting line is formed. An operator maintenance inspection path is formed along the mounting line on the right side of the screen printing apparatus. In the screen printing apparatus, operation switches and a monitor are arranged on the front side shown in FIG. Further, the right side in FIG. 1 is the home position (operator standing position) of the screen printing apparatus.

  A four-axis unit 10 is disposed on the printing stage 3.

  The 4-axis unit 10 supports the substrate W and positions it from below with respect to a mask sheet M to be described later. The substrate W loaded by the carry-in conveyor 2a is horizontally aligned with the X axis, Y axis. The shaft, the Z-axis, and the R-axis (rotation around the Z-axis) are supported to be displaceable.

  That is, the four-axis unit 10 includes a fixed table 11 fixed on the base 1 and an X driven by a servo motor supported relative to the fixed table 11 so as to be movable in the X-axis direction. Axis table 12, a Y axis table 13 provided so as to be movable in the Y axis direction relative to the X axis table 12, and driven by a servo motor, and relatively to the Y axis table 13 An R-axis table 14 that is rotatably provided and driven by a servo motor, and a lift table 15 that is provided so as to be movable up and down with respect to the R-axis table 14 and is driven by a servo motor are hierarchically provided. Then, by supporting the substrate W by the support unit 16 provided on the lifting table 15, the substrate W can be moved in the X axis, Y axis, Z axis, and R axis according to the driving of the tables 12, 13, 14, and 15. It can be moved to any position in the (rotation around the Z axis) direction.

  The support unit 16 includes a plurality of support pins that can be projected and retracted in the Z-axis direction, is attached to the lift table 15 so as to be lifted and lowered, and is attached to the lift table 15 and a substrate support mechanism 17 that directly supports the substrate W. The clamp mechanism 18 clamps the substrate W from both sides in the X-axis direction. The clamp mechanism 18 includes a fixed portion 18a that is connected and fixed to the lifting table 15, and a movable portion 18b that is movable in the X-axis direction with respect to the fixed portion 18a. The upper ends of the fixed portion 18a and the movable portion 18b A conveyor belt for carrying in and out the substrate W as a pair is attached to each part. The position of the movable portion 18b is adjusted corresponding to the size of the substrate W in the X-axis direction. When the substrate W is loaded from the carry-in conveyor 2a onto the conveyor belt of the clamp mechanism 18, the support pins of the substrate support mechanism 17 project to support the substrate W from the lower side (back side) and the clamp mechanism 18 to support the substrate. W is clamped from both sides in the X-axis direction, whereby the substrate W is fixed to the support unit 16 in a positioned state.

  A mask sheet M is stretched above the printing stage 3, and printing is provided above the mask sheet M with a squeegee 41 that extends paste such as cream solder or conductive paste supplied onto the sheet M. A head 6 is provided.

  The head 6 is supported so as to be movable in the X-axis direction and the Z-axis direction, and is driven by a servo motor. That is, a pair of fixed rails 7 extending in the Y-axis direction are provided above the mask sheet M, and the head support member 5 is horizontally mounted on the fixed rails 7 and is driven by a servo motor (see FIG. This support member 5 is connected to a not shown). The head 6 is connected to a ball screw 24 that is mounted on a Z-axis fixed rail 22 provided on the support member 5 and is driven to rotate by a servo motor 23. As a result, the head 6 moves integrally with the support member 5 in the X-axis direction by driving the servo motor 23 and the like, and the head 6 moves in the Z-axis direction with respect to the support member 5.

  3 to 5 show a specific configuration of the head 6. FIG. 3 is a side view, FIG. 4 is a perspective view, and FIG. 5 is an exploded perspective view of FIG. .

  As shown in these drawings, the head 6 has a plate-like main frame 20 (see FIGS. 1 and 2), and is supported by the fixed rail 22 and the like via the main frame 20. An arm member 20c having an inverted L-shaped cross section is fixed to the main frame 20, and a support portion 20b in which a pressure sensor 20a such as a load cell is interposed is suspended from the arm member 20c. A subframe 26 is swingably supported by 20b. Specifically, as shown in FIG. 4, a first support shaft 25 extending in the X-axis direction protrudes from the support portion 20 b, and the sub-frame 26 is attached to the first support shaft 25 via a bearing or the like. Thus, the sub-frame 26 is swingably supported around the first support shaft 25.

  Here, in the present embodiment, as shown in FIG. 3, a unit assembling member 28 (squeegee assembling portion) is rotatably supported on the subframe 26, and the unit assembling member 28 is driven. A rotating drive mechanism is mounted. Further, the screen printing apparatus is provided with a control means 60 for rotating the unit assembling member 28 with respect to the head 6 by a rotation driving mechanism.

  As shown in FIG. 5, the unit assembly member 28 is a rectangular plate-like member that is elongated in the Y-axis direction, and rotates to the subframe 26 via a support portion 28a erected in the middle in the longitudinal direction. Supported as possible. Specifically, a second support shaft 27 extending in the Y-axis direction is supported by the subframe 26 in a state where the second support shaft 27 can rotate about the axis, and the unit assembly member 28 is supported by the second support shaft 27 on a support portion 28a. The unit assembly member 28 is swingably supported with respect to the subframe 26.

  As shown in FIG. 3, the unit assembly member 28 is attached to the subframe 26 via a second support shaft 27 provided on the home position side below the subframe 26. 27 is disposed above the side opposite to the home position (the left side in FIG. 3), and a rotary drive mechanism such as a sub-frame 26 and a servo motor 32 supported by the sub-frame 26 is disposed. The rotation of the attaching member 28 to the opposite side to the home position is restricted by the subframe 26 and the rotation drive mechanism. On the other hand, since no member that restricts the rotational movement of the unit assembly member 28 is disposed on the home position side of the second support shaft 27, the unit assembly member 28 is attached to the subframe 26. It is possible to make a large rotation to the home position side. The second support shaft 27 is an axis in a direction orthogonal to the moving direction of the squeegee. The support portion 28a is attached and fixed to the portion where the second support shaft 27 protrudes from the subframe 26 by key connection.

  The second support shaft 27 that supports the unit assembling member 28 protrudes through the subframe 26 to the opposite side, and a pulley 34 is attached and fixed to the protruding portion by key coupling. A servo motor 32 as a drive source is fixed to the sub-frame 26, and a drive belt 36 is attached across the pulley 33 attached to the output shaft of the servo motor 32 and the pulley 34. Further, the drive belt The drive belt 36 is stretched by the tension pulley 38 being in pressure contact with the outer periphery 36. That is, the servo motor 32, the pulleys 33 and 34, the tension pulley 38, and the drive belt 36 constitute the “rotation drive mechanism” of the present invention, and the servo motor 32 is operated by the control means 60. As a result, the unit assembly member 28 is driven to rotate forward and backward around the second support shaft 27. The origin position of the unit assembly member 28 with respect to the subframe 26 is detected, and a reference position used for controlling the rotation angle of the servo motor 32 is obtained.

  At the time of printing, the control means 60 rotates the unit assembly member 28 within a set range so that the angle formed by the squeegee 41 and the mask sheet M is less than a predetermined angle (for example, 70 °) smaller than 90 °, and printing is performed. At other times, the rotation drive mechanism is controlled so that the unit assembling member 28 is largely rotated toward the home position until the angle becomes 90 ° or more.

  A squeegee unit 40 is detachably attached to the rotating front end side of the unit assembly member 28. As shown in FIGS. 3 to 5, the squeegee unit 40 includes a squeegee 41 and a squeegee holder 42 that holds the squeegee 41. The squeegee 41 has a second support on the lower side of the second support shaft 27. It rotates on a circumference around the shaft 27.

  The squeegee holder 42 is a plate-like member elongated in the Y-axis direction and made of a light alloy such as an aluminum alloy. On the other hand, the squeegee 41 is a rectangular plate-like member made of, for example, hard urethane or stainless steel and elongated in the Y-axis direction, and is held by the squeegee holder 42 in a state of being superimposed on the squeegee holder 42 as shown in FIG. Has been.

  The squeegee holder 42 has an assembly surface 42 a for assembling the squeegee holder 42 to the unit assembly member 28 on the opposite side of the surface on which the squeegee 41 is held. A pair of screw shafts 46 project integrally from the assembly surface 42a at a predetermined interval in the Y-axis direction, and a fixing nut 47 provided with a knob portion at the tip of these screw shafts 46. Is screwed on.

  At both ends in the longitudinal direction of the squeegee holder 42, a side leakage prevention plate 44 is assembled in a freely rotatable (swinging) manner by a fixing bolt 50, and a substantially V-shaped biasing member 48 ( (See FIG. 3) and is elastically held at a predetermined neutral position. These lateral leakage prevention plates 44 are members for preventing the paste from flowing and leaking (escaping) to the side of the squeegee 41 (outside in the Y-axis direction) during printing operations.

  The squeegee unit 40 as described above is assembled and fixed to the unit assembly member 28 by the fixing nut 47 in a state where the squeegee unit 40 is superimposed on the unit assembly member 28. Specifically, as shown in FIG. 5, a pair of notches 30 corresponding to the screw shafts 46 of the squeegee unit 40 are formed at both ends of the unit assembly member 28 in the Y-axis direction. The squeegee unit 40 is overlaid on the lower surface of the unit assembly member 28 via the assembly surface 42a in a state where the screw shafts 46 are inserted from the side with respect to the notch 30, and further, in this state, the fixing nut 47 As a result, the squeegee unit 40 is retracted and fixed to the lower surface of the unit assembly member 28. That is, the squeegee unit 40 is fixed to the unit assembly member 28 by sandwiching the unit assembly member 28 between the fixing nut 47 and the squeegee unit 40.

  Next, with reference to FIGS. 6-9, the printing operation and effect of the screen printing apparatus as described above will be described.

  First, after the substrate W in a state of being superimposed on the mask sheet M is positioned at a predetermined reference position, the operation start instruction input operation by the operator is performed, or in the case of automatic operation, the substrate W is masked. After rising to a position overlapping the sheet M from below, as soon as the next step, the head 6 is actuated to start a printing operation in the screen printing apparatus.

  Specifically, the head 6 moves along a pair of fixed rails 7 by the operation of a servo motor (not shown), and as shown in FIG. 6, the squeegee 41 is disposed on the upper left side of a predetermined work start position. When the squeegee 41 moves (forwards) to the right home position side (see FIGS. 1 and 3), for example, the servo motor 32 is driven by the control means 60 as shown in FIG. As a result, the unit assembling member 28 is rotated and displaced counterclockwise, and the work surface 41a of the squeegee 41 is set in a direction toward the traveling direction. At this time, the unit assembling member 28 is rotated so that the attack angle of the squeegee 41 is 55 ° to 65 °. The attack angle is a contact angle of the squeegee 41 with respect to the mask sheet M, that is, an inclination angle of the squeegee 41 with respect to the mask sheet M when the squeegee 41 is brought into contact with the mask sheet M to perform paste expansion work. It is substantially equal to the angle α formed by the center line L1 of 41 and the perpendicular line L2 with respect to the mask sheet M. Thereby, in this embodiment, the unit assembly member 28 is rotated so that the angle α formed by the center line L1 and the perpendicular line L2 during the printing operation is 55 ° to 65 °.

  Next, the head 6 moves down along the pair of fixed rails 22 by the operation of the servo motor 23, and the squeegee 41 is set at a height position where the edge portion contacts the contact point on the mask sheet M. At this time, the squeegee 41 is pressed against the mask sheet M at a preset pressure by driving and controlling the head 6 based on the detection value by the pressure sensor 20a. When the squeegee 41 is set at a height position where the squeegee 41 contacts the mask sheet M in this way, the side leakage prevention plate 44 comes into contact with the mask sheet M.

  When the squeegee 41 is pressed against a predetermined contact point, that is, a printing work start position, paste is supplied onto the mask sheet M by a supply device (not shown), and the squeegee 41 is moved in the X-axis direction by the operation of the head 6. The paste on the mask sheet M is expanded by the squeegee 41 by this movement (forward movement), and the paste is applied to the substrate W through the opening formed in the mask sheet M. (Printed).

  When the squeegee 41 reaches the end position on the home position side, the head 6 is raised, and printing is still performed instead of the processed substrate W on which printing has been performed by the movement (forward movement) of the squeegee 41 described above. An unprocessed substrate W that has not been placed is positioned at a predetermined reference position in a state of being superimposed on the mask sheet M. Then, when the servo motor 32 is driven by the control means 60, the unit assembly member 28 is rotationally displaced (reversely driven) in the clockwise direction, and the work surface 41a of the squeegee 41 moves in the traveling direction as shown in FIG. Set to the state toward At this time, the position of the contact point of the squeegee 41 on the mask sheet M with respect to the second support shaft 27 changes from the right to the left by the rotation of the unit assembly member 28, so the position of this contact point is moved to the left. At the same time as the reverse movement, the head 6 is additionally moved in the right (forward) direction simultaneously with the reverse driving of the second support shaft 27 so as to be on the right side of the paste. Also at this time, the unit assembly member 28 is rotated so that the angle α (attack angle of the squeegee 41) formed by the center line L1 and the perpendicular line L2 during the printing operation is 55 ° to 65 °. Then, after the squeegee 41 is set at a height position that contacts the contact point on the mask sheet M as described above, the squeegee 41 moves away from the home position along the X-axis direction. The paste on the mask sheet M is expanded by the squeegee 41.

  After that, the squeegee 31 reciprocates along the mask sheet M while reversing the direction of the squeegee 41 and the support member 5 is additionally moved in this manner, whereby the paste is sequentially printed on each substrate W fed into the printing apparatus. Will be.

  When the reciprocating operation is repeated a predetermined number of times, the printing operation for one lot of the substrates W is completed, the squeegee 41 is reset to a predetermined home position (right side in FIG. 1), and a series of operations by the screen printing apparatus is performed. The printing operation ends.

  Here, in this embodiment, after the printing work is completed, the squeegee unit 40 is replaced with a unit corresponding to the next production (next lot), that is, a unit holding the squeegee 41 corresponding to the next production as necessary. This squeegee replacement work is an operator's work. In this case, when the operator performs an instruction input operation such as squeegee replacement, the servo motor 32 is operated by the control means 60, and as shown in FIG. The unit assembling member 28 is greatly displaced in the counterclockwise direction. Then, the work surface 41a of the squeegee 41 is set so as to face upward on the home position side (upper right in FIG. 9). The angle β formed between the center line L1 of the squeegee 41 and the vertical line L2 with respect to the mask sheet M during the squeegee exchange is larger than the angle α formed between the center line L1 and the vertical line L2 during the printing operation described above. In the embodiment, the unit assembly member 28 is rotated so as to be 90 ° to 110 °.

  In this state, the operator loosens the fixing nut 47 of the squeegee unit 40 to release the fixed state with respect to the unit assembly member 28, and then moves the squeegee unit 40 from the unit assembly member 28 along the notch 30. The squeegee unit 40 is removed from the head 6 by pulling apart.

  Then, the squeegee unit 40 holding the squeegee 41 corresponding to the next production is assembled to the unit assembling member 28 of the head 6. That is, the operator superimposes the squeegee unit 40 on the unit assembly member 28 while inserting each screw shaft 46 of the squeegee unit 40 into the notch 30 of the unit assembly member 28, and then tightens the fixing nut 47 to tighten the squeegee. The squeegee unit 40 is assembled to the head 6 by fixing the unit 40 to the unit assembling member 28.

  Further, in the screen printing apparatus as described above, when printing is interrupted such as setup change for replacing the mask sheet M, the paste adhered to the work surface 41a of the squeegee 41 deteriorates due to contact with air for a long time. In order to avoid this, it is necessary to remove the paste adhering to the work surface 41a of the squeegee 41. At the time of maintenance such as this paste removal operation, an instruction input operation such as maintenance by the operator is performed as described above. As a result, the servo motor 32 is operated by the control means 60 and the unit assembly member 28 is driven to rotate counterclockwise. And as shown in FIG. 9, the work surface 41a of the squeegee 41 is set to the state which goes to the upper direction of a home position side. Also during the maintenance, the unit assembling member 28 is rotated so that the angle β formed by the center line L1 and the perpendicular line L2 is 90 ° to 110 °, as in the squeegee replacement.

  As described above, in this screen printing apparatus, while the squeegee 41 is rotatably provided on the head 6, the angle formed by the center line L1 of the squeegee 41 and the perpendicular line L2 with respect to the mask sheet M is set as described above. The control means 60 for rotating the unit assembling member 28 with respect to the head 6 by the servo motor 32 is provided so that the angle α sometimes becomes the angle α that exceeds the angle α at the time of squeegee replacement and maintenance. Therefore, the operator can easily visually recognize the work surface 41a on which the operator presses the paste of the squeegee 41 during squeegee replacement and maintenance.

  Therefore, while maintaining the advantages of this type of screen printing apparatus such as the degree of freedom in setting the angle of the squeegee 41, there is an effect that the workability at the time of squeegee replacement and maintenance can be improved. When the operator works from the home position side, it is turned counterclockwise as shown in FIG. 9, but when the operator works from the anti-home position side, the unit is turned clockwise as shown in FIG. The assembly member 28 and the squeegee 41 may be rotated by more than 70 ° within a range that does not interfere with other parts of the head 6. In this case, the head 6 is preferably moved to the end (position close to the operator) in the movable range in the X direction.

  In particular, in this screen printing apparatus, the angle formed by the center line L1 of the squeegee 41 and the perpendicular L2 with respect to the mask sheet M is an angle α (55 ° to 65 °) smaller than 90 ° during printing, and at the time of squeegee replacement and Since the control means 60 for rotating the unit assembly member 28 with respect to the head 6 by the servo motor 32 is provided so that the angle β (90 ° to 110 °) is 90 ° or more during maintenance, the squeegee is replaced. At the time of maintenance and maintenance, the work surface 41a of the squeegee 41 can be directed to a vertical surface or more. Thereby, since the operator can visually recognize the work surface 41a of the squeegee 41 more easily, the workability at the time of squeegee replacement and maintenance can be further improved.

  In this screen printing apparatus, the control means 60 uses the single rotational drive mechanism to place the unit assembly member 28 on the head 6 both during printing and at times other than printing (during squeegee replacement and maintenance). Since it can be made to rotate with respect to it, it can suppress that an apparatus enlarges.

  The above-described screen printing apparatus is an example of the screen printing apparatus according to the present invention, and the specific configuration thereof can be appropriately changed without departing from the gist of the present invention.

  For example, in the above embodiment, the work surface 41a of the squeegee 41, that is, the surface for pressing the paste is a flat surface. However, the present invention is not limited to this, and the work surface 41a of the squeegee 41 is a convex surface or a concave surface. It doesn't matter.

  In the above embodiment, the angle α as the attack angle is set to 55 ° to 65 °. However, the present invention is not limited to this, and the angle α can be set to any angle smaller than 90 °. , 40 ° to 75 ° is preferable. Further, although the angle β at the time of squeegee replacement and maintenance is set to 90 ° to 110 °, the present invention is not limited to this, and the angle β may be set to a value smaller than 90 ° if the angle β is larger than the angle α. , A value larger than 110 ° may be set.

  In the above-described embodiment, the configuration in which the unit assembling member 28 is rotated with respect to the head 6 using a belt-driven rotational drive mechanism has been described. However, the present invention is not limited thereto, and a plurality of gears are combined. Alternatively, the unit assembly member 28 may be rotated with respect to the head 6 using a gear drive type rotational drive mechanism that transmits the drive.

1 is a front view showing an overall configuration of a screen printing apparatus according to an embodiment of the present invention. FIG. 2 is a side view of the screen printing apparatus according to the embodiment shown in FIG. 1. It is the enlarged view which showed the structure of the head of the screen printing apparatus by one Embodiment shown in FIG. It is the perspective view which showed the structure of the raising / lowering unit of the screen printing apparatus by one Embodiment shown in FIG. It is the perspective view which showed the state which removed the squeegee unit from the unit assembly member of the raising / lowering unit shown in FIG. FIG. 2 is a schematic diagram showing a positional relationship between a squeegee and a mask sheet in an initial state of a printing operation of the screen printing apparatus according to the embodiment shown in FIG. 1. It is the schematic diagram which showed the positional relationship of the squeegee and mask sheet at the time of the printing operation of the screen printing apparatus by one Embodiment shown in FIG. It is the schematic diagram which showed the positional relationship of the squeegee and mask sheet at the time of the printing operation of the screen printing apparatus by one Embodiment shown in FIG. It is the schematic diagram which showed the positional relationship of the squeegee and mask sheet at the time of squeegee exchange of the screen printing apparatus by one Embodiment shown in FIG.

Explanation of symbols

6 Head 27 Second support shaft 28 Unit assembly member (squeegee assembly part)
32 Servo motor (rotary drive mechanism, squeegee rotating means)
33, 34 pulley (rotary drive mechanism, squeegee rotating means)
36 Drive belt (rotary drive mechanism, squeegee rotating means)
38 Tension pulley (rotary drive mechanism, squeegee rotating means)
41 Squeegee 42 Squeegee holder 60 Control means (squeegee rotating means)
L1 Center line M Mask sheet W Printed circuit board (board)

Claims (3)

A head that supports the squeegee and relatively reciprocally moves the squeegee along a mask sheet superimposed on a substrate, the squeegee rotating about an axis perpendicular to the moving direction of the squeegee with respect to the head; In the screen printing apparatus provided movably,
The squeegee has one side as a work surface for paste pressing, and the shaft is located on the opposite side of the work surface with respect to the squeegee,
Squeegee rotating means for rotating the squeegee around the axis over a state inclined to one side and a state inclined to the opposite side from a state where the work surface faces in parallel with the mask sheet;
The squeegee is in a state where one edge portion of the work surface is in contact with the mask sheet during forward printing, and the other edge portion of the work surface is in contact with the mask sheet during backward printing. Is configured to apply paste by moving,
The squeegee rotating means rotates the squeegee with respect to the head so that an angle formed by the squeegee and the mask sheet is equal to or less than a predetermined value during printing and exceeds the predetermined value except during printing. It characterized the Turkey is, the screen printing apparatus. The screen printing apparatus according to claim 1,
The head is provided with a squeegee assembling portion that can rotate around the shaft,
A squeegee holder that holds the squeegee is detachably assembled to the rotation tip side of the squeegee assembly part,
As the squeegee rotating means,
A rotational drive mechanism for rotationally driving the squeegee assembly part around the axis;
The rotation drive mechanism rotates the squeegee assembly portion with respect to the head so that the angle formed by the squeegee and the mask sheet is less than or equal to a predetermined value during printing and exceeds the predetermined value except during printing. Control means to be moved ,
The screen printing apparatus, wherein the rotary drive mechanism is provided on the head above one side in the moving direction of the shaft, and the squeegee is located on the other side in the moving direction except during printing. The screen printing apparatus according to claim 1 or 2,
The screen printing apparatus, wherein an angle formed by the squeegee and the mask sheet is equal to or smaller than a predetermined value smaller than 90 ° during printing and is equal to or larger than 90 ° except during printing.

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