JP2018079613A - Screen printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screen printer equipped with a rotation drive type edge clamp.SOLUTION: A screen printer comprises: a squeeze device for painting and extending a cream solder over a mask formed with a printing pattern; a transport device for transporting a substrate to below the mask; a lifting device for positioning the substrate in the vertical direction with respect to the mask; a clamp device for clamping the transported substrate in a width direction by a pair of clamp portions 35, and having a plurality of recesses 53 in each of the clamp portions 35 in each of which a clamp piece 52 fixed and rotationally supported on one rotation axis 56 is arrange; and a rotary drive mechanism 63 for applying rotations to the rotation shaft 56 thereby to switch into the storage state in which the clamp piece 52 is stored in the clamp portion 35, and a clamp state in which the tip part is protruded from the clamp portion 35.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a screen printing machine for printing cream solder on a substrate.

  In the screen printing machine, a mask having a printing pattern (through hole for printing) is attached to the inside of the machine body, and the substrate conveyed by the substrate conveying device is disposed below the mask. And the screen printing by cream solder is performed to the conveyed board | substrate. Such a screen printing machine is provided with a substrate holding device or the like for holding the conveyed substrate and positioning it at a printing location in addition to the substrate conveying device. The substrate holding device has an edge clamp that supports the substrate end from above so that the substrate can be clamped in a stable state while the substrate in a horizontal position is sandwiched from the lateral direction at the printing position under the mask. It is used. Patent Document 1 below discloses a screen printer provided with the edge clamp.

  In the screen printing machine described in this document, the conveyed substrate is sandwiched from the width direction by a pair of clamp units and held in a horizontal state. At that time, the substrate is lifted from below by the backup unit, and the width of the substrate is increased. The directional end is supported by hitting a positioning plate which is an edge clamp arranged on the upper side. The positioning plate is assembled to a drive mechanism that allows movement in the vertical direction and the horizontal direction, and moves between a retracted position outside the clamp unit and a clamp position above the clamp unit during clamping. After the substrate is clamped, the upper surface of the substrate is overlapped with the lower surface of the mask for printing, so that the positioning plate does not hinder printing.

JP-A-10-296948

  However, such a movement of the positioning plate is performed in two stages of the vertical direction and the horizontal direction, so that the time for clamping the substrate by the clamp unit becomes long, and the cycle time is extended. In addition, the positioning plate driving mechanism that switches the moving direction in two stages has problems such as an increase in the number of parts and a complicated and large structure, and an increase in cost.

  By the way, in the same patent document 1, there is a suggestion about an edge clamp in which the positioning plate is a long plate material having an L-shaped cross section, and is rocked by a motor. Such an edge clamp has an effect of narrowing the movable range of the positioning plate, and is considered to lead to the solution of the above problem. However, the positioning plate based on the suggestion has a length substantially the same as the length of the end surface in the width direction of the substrate, and it is considered that the positioning plate is rotatably incorporated in the clamp portion of the clamp unit. If such a positioning plate is simply incorporated in the clamp part, another problem arises that the original function of the clamp part is impaired due to a change in the shape of the clamp part.

  Accordingly, an object of the present invention is to provide a screen printer provided with a rotationally driven edge clamp in order to solve such a problem.

  A screen printing machine according to the present invention includes a squeegee device that spreads cream solder on a mask on which a printing pattern is formed, a transport device that transports the substrate under the mask, and the substrate in the vertical direction with respect to the mask. A lifting device for positioning and a substrate to be conveyed are sandwiched by a pair of clamp portions from the width direction. A plurality of concave portions are formed in each of the clamp portions, and fixed to one rotating shaft in each of the concave portions. A clamp device in which a rotation-supported clamp piece is arranged, a storage state in which the clamp piece is stored in the clamp portion by applying rotation to the rotation shaft, and a clamp in which a tip portion protrudes from the clamp portion And a rotation drive mechanism that switches to a state.

  According to the configuration disclosed above, when the transported substrate is sandwiched between the pair of clamp portions from the width direction, the clamp pieces in the plurality of recesses formed in the clamp portions are swung by the rotational drive mechanism and stored. Thus, the end portion of the substrate is supported from above by switching to the clamped state in which the tip portion protrudes from the clamp portion. Accordingly, the swinging clamp piece can be switched between the retracted state and the clamped state in a short time.

It is the figure which showed simply the internal structure of one Embodiment of a screen printer. It is the perspective view which showed the clamp part. It is the top view which showed the clamp part. It is sectional drawing of the clamp piece shown by the AA arrow of FIG. 3 about a clamp part in a retracted state. It is sectional drawing of the clamp piece which the clamp piece shown by the AA arrow of FIG. 3 about a clamp part is a clamp state.

  Next, an embodiment of a screen printer according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram simply showing the internal configuration of the screen printing machine according to the present embodiment. The screen printing machine 1 is configured as a pre-process of a component execution machine that mounts electronic components on a substrate. The screen printing machine 1 includes a substrate transport device 3, a squeegee device 4, a clamp device 5 that grips the substrate, and a lifting device 6 that positions the substrate in the vertical direction. And the control apparatus which controls the whole screen printing machine is mounted, and the predetermined control with respect to the drive part of each apparatus is performed.

  In the screen printing machine 1, the substrate 10 is carried in and out by the substrate conveying device 3, and the substrate conveying device 3 is constituted by a pair of conveyor belts 11 that support both sides of the substrate 10. The substrate 10 is fed in a direction penetrating through (machine body width direction). A clamp device 5 that holds the substrate transfer device 3 and the substrate 10 is assembled to the lifting device 6. Therefore, the substrate 10 carried into the screen printing machine 1 is held by the clamp device 5 and moved up to be positioned at a printing position immediately below the mask 8. The mask 8 is fitted in a rectangular frame member and fixed in a horizontal state.

  On the set mask 8, linear cream solder is supplied in the body width direction. The cream solder is pushed into the printing pattern while rolling on the mask 8 by the squeegee device 4, and is applied to the substrate 10 located under the mask 8. Such a squeegee device 4 is mounted on the traveling platform 12 in a state in which a pair of squeegee heads 401 and 402 having a squeegee can be moved up and down by a cylinder. The traveling table 12 is slidably assembled with respect to a guide rod 13 installed in the horizontal direction (the longitudinal direction of the machine body), and can move linearly in the horizontal direction. Further, a screw shaft 15 parallel to the guide rod 13 is installed in the screen printing machine 1 in a rotatable state, and is rotated by a drive motor. A ball screw mechanism is constituted by the fixing nut and the screw shaft 15 inside the carriage 12.

  Next, on the lower side of the set mask 8, a substrate transfer device 3, a clamp device 5, an elevating device 6 and the like for holding and positioning the substrate 10 are configured. The lifting device 6 is assembled with a lifting platform 22 so as to slide along a vertical guide rail 21, and the lifting platform 22 is connected to a lifting motor 23 via a ball screw mechanism 24. A substrate transfer device 3, a clamp device 5, and the like are mounted on the lift table 22 via a support table 25. Although not described in detail, the support base 25 is configured such that the position of the support base 25 can be adjusted in the X direction, the Y direction, and the θ direction on the XY plane.

  A pair of mask supports 26 are disposed on the support base 25 in the longitudinal direction of the machine body, and the clamp device 5 is disposed therebetween. A pair of mask supports 26 located at the front and rear are respectively provided with gate-shaped legs 261 in the body width direction, and a mask support plate 262 that contacts the mask 8 is fixed to the upper surface thereof. The movable mask support 26 located on the right side of the drawing is configured with a ball screw mechanism in which a fixing nut inside the leg 261 and one screw shaft 27 are screwed together. Therefore, the distance from the fixed side mask support 26 can be adjusted by controlling the drive motor that rotates the screw shaft 27.

  The clamp device 5 includes a pair of side frames 33 and 34 disposed in front of and behind the support base 31, and a screw shaft 36 is screwed into an internal fixing nut in the movable side frame 34 to form a ball screw mechanism. The distance from the fixed side frame 33 can be adjusted by the rotation of the clamping motor with respect to the screw shaft 36. And the clamp part 35 is formed in the upper end part of the side frames 33 and 34, and the board | substrate 10 can be hold | gripped now by mutual distance. The conveyor belt 11 is assembled to the side frames 33, 34 below the clamp portion 35, and the substrate transfer device 3 is configured to transfer the substrate 10 between the side frames 33, 34.

  A backup mechanism is also provided between the side frames 33 and 34. The backup mechanism is provided with a plurality of backup pins 38 arranged so as to avoid electronic components mounted on the substrate 10 with respect to the backup table 37. The support base 31 of the clamp device 5 is supported via a ball screw mechanism that converts the rotational output of the lifting motor 41 into a lifting motion. Further, the drive motor 42 is fixed to the support base 31, and the backup table 37 is supported via a ball screw mechanism that converts the rotation output of the elevating motor 42 into elevating motion.

  In the clamp device 5 of the present embodiment, a rotationally driven edge clamp is configured in the clamp portion 35. Here, FIGS. 2 to 5 are views showing the clamp portion 35. In particular, FIG. 2 is a perspective view, and FIG. 3 is a plan view. 4 and 5 are cross-sectional views taken along arrows AA shown in FIG. The clamp part 35 has a base block 51 fixed on the side frames 33, 34, and a plurality of clamp pieces 52 are assembled to the base block 51 in a rotatable state. The clamp piece 52 is an L-shaped block with a short width, and is inserted into a storage recess 53 formed in the base block 51 in a rotatable state.

  The base block 51 is a strip-like long block formed corresponding to the size of the substrate 10, and is provided with a clamp surface 54 that sandwiches the substrate 10 from the width direction. The base block 51 has a plurality of storage recesses 53 formed at predetermined intervals in the longitudinal direction. The base block 51 is formed with a plurality of suction holes 55 opened on the upper surface, and a vacuum device (not shown) is connected to the suction holes 55. That is, the mask 8 can be sucked and held with respect to the base block 51 in contact with the lower surface of the mask 8 during printing. Therefore, on the upper surface of the base block 51, notched portions by the plurality of storage recesses 53 and openings of the plurality of suction holes 55 so as to avoid the storage recesses 53 are arranged.

  The storage recess 53 is formed with a rectangular parallelepiped recess that opens to the opposite side of the clamp surface 54, and one clamp piece 52 is placed in each recess. Inside the base block 51, a rotation shaft 56 is inserted along the longitudinal direction so as to cross all the storage recesses 53. And the clamp piece 52 put into the storage recessed part 53 is formed in the rotating shaft 56 integrally. Accordingly, when the rotation is applied to the rotating shaft 56, all the clamp pieces 52 are simultaneously swung to be switched between the retracted state shown in FIG. 4 and the clamped state shown in FIG. In FIG. 3, the clamp piece 52 in the retracted state is indicated by a solid line, and the clamp piece 52 in the clamped state is indicated by a one-dot chain line.

  The rotating shaft 56 is rotatably supported in the base block 51, and one end portion side extends to the outside of the base block 51. A gear 61 is fixed to the end of the rotating shaft 56, and a gear 62 fixed to the output shaft of the rotary actuator 63 is engaged with the gear 61. The rotational drive mechanism including the gears 61 and 62 and the rotary actuator 63 is assembled to the side frames 33 and 34. Accordingly, the rotation output of the rotary actuator 63 causes the rotation of the rotating shaft 56 via the gears 61 and 62, and the state of the oscillating clamp piece 52 is switched.

  In the screen printing machine 1 configured as described above, the substrate 10 is carried in between the side frames 33 and 34 by the conveyor belt 11. Then, the backup table 37 is raised by driving the lifting motor 42 and the substrate 10 is lifted from the conveyor belt 11 so as to be pushed up by the backup pin 38. Further, the rotation of the screw shaft 36 causes the side frame 34 to move, and the substrate 10 is sandwiched between the clamp portions 35 of the side frames 33 and 34. At that time, in the clamp unit 35, the rotary shaft 63 is rotated by the drive of the rotary actuator 63, and the clamp piece 52 is switched from the retracted state shown in FIG. 4 to the clamped state shown in FIG.

  In the base block 51, the tip end portion of the clamp piece 52 protrudes from the upper surface thereof, and thus the lifted substrate 10 hits the tip end portion of the clamp piece 52 on the end portion in the width direction. Therefore, the substrate 10 is sandwiched between the pair of clamp portions 35 so that the width direction end portion is supported from above by the clamp piece 52 and is pushed up by the backup pin 38 from below and kept flat. It is. After the substrate 10 is clamped in this way, the rotary actuator 63 is driven again, the rotating shaft 56 rotates in the reverse direction, and the clamp piece 52 is returned from the clamped state shown in FIG. 5 to the retracted state shown in FIG.

  Subsequently, by driving the lifting / lowering motor 41, the entire clamping device 5 holding the substrate 10 is raised, the clamp portion 35 and the substrate 10 are aligned with the height of the mask support plate 262, and the height of the upper surface is aligned. It is done. The elevating table 22 is raised by driving the elevating motor 23, and stops at a printing position where the upper surfaces of the mask support plate 262, the clamp part 35, and the substrate 10 are in light contact with the lower surface of the mask 8.

  Thereafter, in the clamp portion 35, the mask 8 is evacuated through the suction holes 55 formed in the base block 51. In addition, a similar suction hole is formed in the mask support plate 262, and the mask 8 is similarly evacuated so that the clamped substrate 10 and the mask 8 are positioned in a stable state. Then, cream solder is supplied on the upper surface side of the mask 8 and is pushed into the print pattern while rolling by the squeegee device 4. Thereby, the cream solder is printed on the substrate 10 located under the mask 8 through the through hole of the print pattern.

  Therefore, in this embodiment, when the substrate 10 is clamped by the clamp portion 35, the clamp piece 52 is switched between the retracted state and the clamped state by swinging, but the movable range is narrow and the state is switched in a short time. It is done. Therefore, the time required for clamping the substrate 10 can be shortened, and the cycle time can be shortened. The clamp piece 52 is incorporated in the base block 51 of the clamp portion 35, and the driving means is also constituted by gears 61 and 62 and a rotary actuator 63. Therefore, the configuration of the edge clamp in the main body of the screen printing machine 1 is compact, and the number of parts is small, so that the cost can be suppressed.

  In the present embodiment, the plurality of clamp pieces 52 constitute an edge clamp of the substrate 10. That is, the area occupied by the storage recess 53 in which the clamp piece 52 is disposed is reduced with respect to the upper surface of the base block 51 that is in contact with the mask 8. On the other hand, when a long positioning plate that can be read from Patent Document 1 is used in place of the plurality of clamp pieces 52, the motor is enlarged to swing the heavy positioning plate. In that respect, since the plurality of clamp pieces 52 are light, the rotary actuator 63 can also be made small.

  Further, in the case of a long positioning plate, it is necessary to form a storage recess in the entire longitudinal direction of the base block 51, and the storage recess occupies more than half the area of the upper surface of the base block 51. Therefore, the shape of the clamp part (base block 51) changes, and the original function of the clamp part is impaired. That is, the number of suction holes 55 in the clamp part 35 is reduced, and the force for sucking and holding the mask 8 during printing is weakened. Further, when the area of the storage recess becomes large, a portion where the mask 8 cannot be supported is formed on the upper surface of the base block 51, and the mask 8 is bent by the printing pressure received from the squeegee, and cream solder remains there. Will end up.

  Since the cream solder remaining on the mask 8 is deteriorated, when it is repeatedly performed thereafter, the deteriorated solder is mixed into normal cream solder, and the quality is deteriorated. In this regard, in this embodiment, since the area occupied by the storage recess 53 is small on the upper surface of the base block 51, the reduction of the suction holes 55 can be suppressed and the mask 8 can be sucked and held in a stable state. Further, since one storage recess 53 has a small area on the upper surface of the base block 51 and there is a distance between the adjacent storage recesses 53, the mask 8 is supported by the base block 51 even in a range where the storage recesses 53 are arranged, and cream solder There will be no flexion that will leave behind.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to this, A various change is possible in the range which does not deviate from the meaning.
For example, in the above-described embodiment, the rotary drive mechanism including the gears 61 and 62 and the rotary actuator 63 is shown. However, a rack that linearly reciprocates with a pinion fixed to the rotary shaft 56 is engaged. There may be.

DESCRIPTION OF SYMBOLS 1 ... Screen printer 3 ... Board | substrate conveyance apparatus 4 ... Squeegee apparatus 5 ... Clamp apparatus 6 ... Elevating apparatus 8 ... Mask 10 ... Board | substrate 35 ... Clamp part 51 ... Base block 52 ... Clamp piece 53 ... Storage recessed part 54 ... Clamp surface 55 ... Suction hole 61, 62 ... Gear 63 ... Rotary actuator

Claims (4)

A squeegee device for spreading cream solder on a mask on which a printed pattern is formed;
A transfer device for transferring a substrate under the mask;
A lifting device for positioning the substrate in a vertical direction with respect to the mask;
A clamp piece that sandwiches a conveyed substrate from a width direction by a pair of clamp portions, each of which has a plurality of recesses, and is fixed to one rotation shaft in each recess and is rotatably supported. A clamping device,
A screen printing machine having a rotation drive mechanism that switches between a retracted state in which the clamp piece is stored in the clamp part and a clamped state in which a tip portion is protruded from the clamp part by rotating the rotating shaft.   The rotating shaft passes through the plurality of recesses and is incorporated into the clamp portion, and the clamp piece is an L-shaped block, and the long side of the L shape protrudes from the upper surface of the clamp portion in a clamped state. The screen printing machine according to claim 1, wherein a short side of the L-shape is fixed to the rotating shaft.   The screen printing machine according to claim 2, wherein an opening portion of a suction hole is formed on a top surface of the clamp portion in a range other than the concave portion. The screen printing machine according to any one of claims 1 to 3, wherein the rotation driving mechanism is configured to give an output of a rotary actuator to the rotation shaft through a gear.

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