JP4363751B2 - Screen printing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a screen printer for printing cream solder on the surface of a circuit board.
[0002]
[Prior art]
FIG. 4 is a main part front view showing an example of this type of conventional screen printing machine. The screen printing machine includes an X-axis base 101, a Z-axis base 102 disposed above the X-axis base 101, a bearing 103 provided on the Z-axis base 102, and a Z-axis base 102. The θ-axis base 104, the three rotary shafts 105 (only two shown) that connect the X-axis base 101 and the Z-axis base 102, the pulleys 106 attached to the lower ends of the rotary shafts 105, and these A motor 107 coupled to the pulley 106, a substrate support mechanism 108 provided on the θ-axis base 104, and a plurality of θ-axis base support mechanisms 109 provided on the Z-axis base 102 are provided.
[0003]
The X-axis base 101 is supported by the housing H via a pair of guide members 110, and is movable in the direction of the X-axis extending in the substantially horizontal direction (direction perpendicular to the paper surface). To reciprocate in the same direction.
[0004]
The θ-axis base 104 is disposed substantially horizontally, and its central axis is supported by a bearing 103 so that it can rotate within a substantially horizontal plane. Three ball nuts 111 (only two are shown) are provided on the Z-axis base 102, and these are screwed into ball screws provided on the outer periphery of the rotary shaft 105, respectively.
[0005]
Each rotary shaft 105 is attached to the X-axis base 101 so as to be rotatable around the axis and not to move in the axial direction, and passes through the X-axis base 101 and the plate 112 disposed below the X-axis base 101. . Each rotary shaft 105 is rotatable about an axis with respect to the plate 112 and does not move in the axial direction.
[0006]
The motor 107 is attached to the upper surface of the plate 112 and is connected to each pulley 106 via a belt (not shown). When the motor 107 is driven, the Z-axis base 102 and the portion above it are in relation to the X-axis base 101. Move up and down.
[0007]
The substrate support mechanism 108 is placed on the backup base 113, a backup base 113 disposed above the θ-axis base 104, a plurality of rotating shafts 114 connecting the backup base 113 and the θ-axis base 104, and the backup base 113. The backup mechanism 115 includes a pair of substrate clamp mechanisms 116 disposed on both sides thereof.
[0008]
A plurality of ball nuts 117 are provided on the backup base 113, and these are screwed into ball screws provided on the outer periphery of the rotating shaft 114.
[0009]
Each rotary shaft 114 is attached to the θ-axis base 104 so as to be rotatable around the axis and not to move in the axial direction, penetrates the θ-axis base 104, and a pulley 118 is fixed to the lower end. Yes. These pulleys 118 are connected to a motor 119 attached to the lower surface of the θ-axis base 104 via a belt (not shown). When the motor 119 is driven, the backup base 113 moves up and down with respect to the θ-axis base 104. .
[0010]
The backup mechanism 115 includes a plate 120 having a large number of holes penetrating in the thickness direction, and a plurality of pins 121 inserted and mounted in any of these holes. The lower surface of the circuit board P is supported at the upper end.
[0011]
The board clamping mechanism 116 clamps the circuit board P by sandwiching the circuit board P conveyed from the direction orthogonal to the paper surface by the pair of conveyors 122 in the left-right direction in the drawing.
[0012]
Each θ-axis base support mechanism 109 provided on the Z-axis base 102 is provided so as to face the edge of the lower surface of the rectangular θ-axis base 104 and slidably receives the lower surface of the θ-axis base 104. I support it.
[0013]
In addition to the above, this screen printer includes a screen support frame 123 that supports the print screen S, a drive mechanism that moves the screen support frame 123 in the Y-axis direction extending in a substantially horizontal direction, the circuit board P, and the screen S. A camera (not shown) for photographing the alignment mark attached to the camera, a control device including a microcomputer, and the like are provided.
[0014]
In order to print on the circuit board P by the screen printer, first, the circuit board P conveyed by the conveyor 122 is clamped by the board clamping mechanism 116. Next, the camera photographs the alignment marks attached to the printing screen S and the circuit board P.
[0015]
Next, the control device calculates the amount of positional deviation between the circuit board P and the printing screen S based on the position information of these marks, the X-axis base 101 is in the X-axis direction, the printing screen S is in the Y-axis direction, and the θ-axis. The base 104 is driven in the θ direction to correct the positional deviation between the circuit board P and the printing screen S.
[0016]
Then, the motor 107 is driven to raise the Z-axis base 102 with respect to the X-axis base 101, and the motor 119 is further driven to raise the backup base 113 with respect to the θ-axis base 104. Pressed against the lower surface of the printing screen S. Then, cream solder is supplied onto the printing screen S, and a squeegee (not shown) slides on the upper surface of the printing screen S to print a pattern on the circuit board P.
[0017]
Since the circuit board P and the printing screen S are preferably as parallel as possible, the parallelism between the circuit board P and the printing screen S is adjusted in the following procedure at the time of shipment from the factory or maintenance. Yes.
[0018]
First, an operation for measuring the distance to the upper surface of the circuit board P with a distance measuring device installed on the screen support frame 123 is performed at a plurality of locations on the upper surface of the circuit board P, and printing of the circuit board P is performed based on the measurement result. The degree of inclination with respect to the screen S is detected.
[0019]
Then, based on the detection result, the amount of protrusion from the Z-axis base 102 of any one or two of the three rotating shafts 105 is adjusted, and the Z-axis base 102 is changed to the X-axis base 101. The circuit board P supported by the board support mechanism 108 and the printing screen S are made parallel by being slightly tilted with respect to the board. This operation is performed by releasing the fixing of the pulley 106 to the rotating shaft 105 and rotating only the rotating shaft 105 by hand. When the adjustment is completed, the pulley 106 is fixed to the rotating shaft 105 again.
[0020]
[Problems to be solved by the invention]
As described above, conventionally, when adjusting the parallelism of the circuit board P with respect to the printing screen S, it is necessary to release and re-fix the pulley 106 with respect to the rotating shaft 105, which is complicated. There was.
[0021]
Further, conventionally, by tilting the Z-axis base 102 with respect to the X-axis base 101, the frictional force between the thread provided on the outer peripheral surface of the rotating shaft 105 and the thread groove of the ball nut 111 is increased. There have been problems such as the vertical movement of the Z-axis base 102 not smoothly moving, and the screwed portion between the rotary shaft 105 and the ball nut 111 being broken.
[0022]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a screen printer capable of easily and without difficulty adjusting the parallelism between the circuit board and the printing screen. It is to provide.
[0023]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the invention of claim 1 rotates the central axis of the θ-axis base so that the θ-axis base arranged substantially horizontally and the θ-axis base rotate in a substantially horizontal plane. A bearing that supports the shaft, a plurality of θ-axis base support mechanisms that slidably support the edge of the lower surface of the θ-axis base, and a substrate support mechanism that is provided on the θ-axis base. In the screen printing machine, the bearing is formed to pivotally support the θ-axis base so that the θ-axis base can tilt, and each θ-axis base support mechanism adjusts an inclination angle of the θ-axis base with respect to a horizontal plane. It is characterized by being able to be formed.
[0024]
According to a second aspect of the present invention, the screen printing machine according to the first aspect includes an X-axis base disposed below the θ-axis base and movable in the X-axis direction extending in a substantially horizontal direction, and each θ-axis is provided. An operating member attached to the X-axis base so that the base support mechanism moves up and down by rotating around an axis, and is arranged between the operating member and the θ-axis base, and rotates with the operating member. And a support member for tilting the θ-axis base.
[0025]
The invention according to claim 3 is the screen printing machine according to claim 1 or 2, further comprising a Z-axis base disposed above the θ-axis base and supported so as to be vertically movable with respect to the θ-axis base, A substrate support mechanism is provided on the Z-axis base.
[0026]
According to a fourth aspect of the present invention, there is provided a screen printing machine according to the third aspect, wherein a screw is provided on an outer peripheral portion and a plurality of rotating shafts connecting the Z-axis base and the θ-axis base, and the rotating shafts are connected to the rotating shaft. A pulley attached to a portion projecting upward from the Z-axis base and a motor coupled to these pulleys are provided. When the motor is driven, the Z-axis base moves up and down with respect to the θ-axis base. It is characterized by being configured.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. 1 is a front view of a main part of a screen printing machine according to an embodiment of the present invention, FIG. 2 is a view taken along the line AA in FIG. 1, and FIG. 3 is a view taken along the line BB in FIG.
[0028]
The screen printing machine of this embodiment includes an X-axis base 1, a θ-axis base 2 disposed above the X-axis base 1, a bearing 3 provided on the X-axis base 1, and a θ-axis base 2. An upper Z-axis base 4, three rotary shafts 5 (only two are shown) connecting the Z-axis base 4 and the θ-axis base 2, and a pulley 6 attached to the upper end of each rotary shaft 5; A motor (not shown) connected to these pulleys 6, a substrate support mechanism 7 provided on the θ-axis base 2, and a plurality of θ-axis base support mechanisms 8 provided on the X-axis base 1. It has.
[0029]
The X-axis base 1 is supported by the housing H via a pair of guide members 9 and is movable in the X-axis direction (direction perpendicular to the paper surface) extending in a substantially horizontal direction. To reciprocate in the same direction.
[0030]
The θ-axis base 2 is disposed substantially horizontally, and a central axis hanging from the central portion thereof is supported by a bearing 3. The bearing 3 is composed of a self-aligning ball bearing, whereby the θ-axis base 2 is supported so as to be rotatable and tiltable within a substantially horizontal plane.
[0031]
Three ball nuts 10 (only two are shown) are provided on the θ-axis base 2, and these are screwed into ball screws provided on the outer periphery of the rotating shaft 5. Each rotary shaft 5 is attached to the Z-axis base 4 so as to be rotatable around the axis and not to move in the axial direction, and extends downward through the X-axis base 1.
[0032]
Each pulley 6 is connected to the motor via a belt (not shown), and when this motor is driven, each rotary shaft 5 rotates, and the Z-axis base 4 and the upper portion thereof are relative to the θ-axis base 2. Move up and down. The pulley 6 is screwed to the upper end portion of the rotating shaft 5 protruding above the Z-axis base 4 and can be screwed to the rotating shaft 5 with good workability while visually confirming the screw position from above.
[0033]
In the prior art shown in FIG. 4, the pulley 106 is screwed from below below the plate 112. Therefore, when screwing, the pulley 106 is supported by one hand while the tool is held by the other hand. It had to be used and screwed, and workability was not good. Further, since the pulley 106 is located near the floor surface, it is difficult to visually recognize the screwing position, and it has been necessary to work in such a posture as to lie on its back.
[0034]
In this embodiment, the pulley 6 can be attached to the rotating shaft 5 with good workability without taking such an unreasonable posture. Moreover, the operation | work which connects the pulley 6 to a motor is also easy.
[0035]
The substrate support mechanism 7 is placed on the backup base 13, a backup base 13 disposed above the Z-axis base 4, a plurality of rotating shafts 14 connecting the backup base 13 and the Z-axis base 4, and the backup base 13. The backup mechanism 15 includes a pair of substrate clamp mechanisms 16 disposed on both sides thereof.
[0036]
A plurality of ball nuts 17 are provided on the backup base 13, and these are screwed into ball screws provided on the outer periphery of the rotating shaft 14.
[0037]
Each rotary shaft 14 is attached to the Z-axis base 4 so as to be rotatable about the axis and not to move in the axial direction, passes through the Z-axis base 4, and a pulley 18 is fixed to the lower end. Yes. These pulleys 18 are connected to a motor 19 attached to the lower surface of the Z-axis base 4 via a belt (not shown). When the motor 19 is driven, each rotary shaft 14 rotates and the backup base 13 rotates to the Z-axis base. It moves up and down with respect to the base 4.
[0038]
The backup mechanism 15 includes a plate 20 in which a large number of holes penetrating in the thickness direction are formed, and a plurality of pins 21 inserted and mounted in any of these holes. The lower surface of the circuit board P is supported at the upper end.
[0039]
The board clamping mechanism 16 clamps the circuit board P by sandwiching the circuit board P conveyed from the direction orthogonal to the paper surface by the pair of conveyors 22 in the left-right direction in the drawing.
[0040]
As shown in FIG. 2, the θ-axis base support mechanism 8 is disposed so as to face the lower surfaces of the four corners of the rectangular θ-axis base 2, and as shown in FIG. And the support member 25 disposed between the operation member 24 and the θ-axis base 2.
[0041]
The operation member 24 includes a base portion 24 a formed in a columnar shape, a large diameter portion 24 b formed on the upper portion thereof, and a small diameter portion 24 c formed on the lower portion of the base portion 24 a, and is formed on the X-axis base 1. The large-diameter portion 24b is accommodated in the hole 1a having a circular cross section so as to protrude, and is rotatable about an axis AX extending in the vertical direction. A screw thread is provided on the outer peripheral portion of the small diameter portion 24 c, and this screw thread is screwed into a screw hole 26 a formed in the plate 26 attached to the lower surface of the X-axis base 1.
[0042]
The support member 25 is configured by an off-the-shelf cam follower, an angle 25a attached to the lower surface of the θ-axis base 2, and a holder 25b formed on the angle 25a and formed with a through hole extending in a substantially horizontal direction, A screw 25c passing through the through hole of the holder 25b and a roller 25e rotatably attached to the holder 25b via a nut 25d screwed to the tip of the screw 25c. The outer periphery of the roller 25e is the operation member 24. It is in contact with the top surface.
[0043]
In addition to the above, the screen printing machine includes a screen support frame 23 that supports the print screen S, a drive mechanism that moves the screen support frame 23 in the Y-axis direction extending in a substantially horizontal direction, the circuit board P, and the screen S. A camera (not shown) for photographing the alignment mark attached to the camera, a control device including a microcomputer, and the like are provided.
[0044]
In order to print on the circuit board P by this screen printer, first, the circuit board P conveyed by the conveyor 22 is clamped by the board clamping mechanism 16. Next, the camera photographs the alignment marks attached to the printing screen S and the circuit board P.
[0045]
Next, the control device calculates the amount of positional deviation between the circuit board P and the printing screen S based on the position information of these marks, the X axis base 1 is in the X axis direction, the printing screen S is in the Y axis direction, and the θ axis. The base 2 is driven in the θ direction to correct the positional deviation between the circuit board P and the printing screen S.
[0046]
Then, the Z-axis base 4 rises with respect to the θ-axis base 2, the backup base 13 rises with respect to the Z-axis base 4, and the upper surface of the circuit board P is pressed against the lower surface of the printing screen S. Then, cream solder is supplied onto the printing screen S, and a squeegee (not shown) slides on the upper surface of the printing screen S to print a pattern on the circuit board P.
[0047]
The parallelism between the circuit board P and the printing screen S is adjusted according to the following procedure.
[0048]
First, an operation for measuring the distance to the upper surface of the circuit board P with a distance measuring device installed on the screen support frame 23 is performed at a plurality of positions on the upper surface of the circuit board P, and the printing of the circuit board P is performed based on the measurement result. The degree of inclination with respect to the screen S is detected, and on the basis of the detection result, it is determined which corner of the θ-axis base 2 is to be lifted by how many mm.
[0049]
When the large-diameter portion 24b of the operation member 24 of the θ-axis base support mechanism 8 arranged at the corner is rotated with the finger in the upward direction, the operation member 24 is raised and the roller 25e is rotated, whereby the support member 25 Pushes up the corner of the θ-axis base 2. Since the bearing 3 that supports the central axis of the θ-axis base 2 supports the central axis in a tiltable manner, the θ-axis base 2 tilts due to a moment acting between the corner of the θ-axis base 2 and the central axis. .
[0050]
As the θ-axis base 2 is tilted, the Z-axis base 4 connected to the θ-axis base 2 and the substrate support mechanism 7 provided on the Z-axis base 4 are integrally tilted and supported by the substrate support mechanism 7. Since the parallelism between the circuit board P and the printing screen S changes, the rotation amount of the operation member 24 is adjusted so that the parallelism between the circuit board P and the printing screen S is within a specified value.
[0051]
As described above, in this embodiment, when adjusting the parallelism of the circuit board P and the printing screen S, it is not necessary to release and re-fix the pulley with respect to the rotation shaft as in the prior art. Workability is good because it only needs to be rotated.
[0052]
Further, since the bearing 3 is a self-aligning ball bearing, an excessive force is not applied to the bearing 3 even if the θ-axis base 2 is inclined, and there is no problem.
[0053]
In addition, this invention is not limited to embodiment mentioned above, A various deformation | transformation can be given to embodiment mentioned above in the range which does not deviate from the summary of this invention.
[0054]
【The invention's effect】
As described above, according to the present invention, the parallelism between the circuit board and the printing screen can be easily adjusted by adjusting the inclination angle of the θ-axis base with respect to the horizontal plane by the θ-axis base support mechanism. Further, since the bearing supports the central axis of the θ-axis base so as to be tiltable, an excessive force is not applied to the bearing, and no trouble occurs.
[0055]
According to the fourth aspect of the present invention, the operation of attaching the pulley to the rotating shaft that connects the Z-axis base and the θ-axis base and the operation of connecting the pulley to the motor can be easily performed.
[Brief description of the drawings]
FIG. 1 is a front view of a main part of a screen printing machine according to an embodiment of the present invention.
FIG. 2 is a view taken along the line AA in FIG.
FIG. 3 is a view taken along the line BB in FIG. 2;
FIG. 4 is a front view of main parts of a conventional screen printing machine.
[Explanation of symbols]
2 θ-axis base 3 Bearing 7 Substrate support mechanism 8 θ-axis base support mechanism P Circuit board S Printing screen

Claims (4)

A θ-axis base disposed substantially horizontally, a bearing that rotatably supports the central axis of the θ-axis base so that the θ-axis base rotates in a substantially horizontal plane, and an edge of the lower surface of the θ-axis base A screen printing machine comprising a plurality of θ-axis base support mechanisms that slidably support a portion and a substrate support mechanism provided on the θ-axis base, wherein the bearings support the θ-axis base. A screen printer, wherein the θ-axis base support mechanism is formed so as to be pivotally supported, and the θ-axis base support mechanism is formed so as to adjust an inclination angle of the θ-axis base with respect to a horizontal plane. An X-axis base disposed below the θ-axis base and movable in the X-axis direction extending in a substantially horizontal direction is provided, and each θ-axis base support mechanism moves up and down by rotating around an axis. An operation member attached to the X-axis base, and a support member that is disposed between the operation member and the θ-axis base and tilts the θ-axis base as the operation member rotates. The screen printer according to claim 1. The Z-axis base disposed above the θ-axis base and supported to be movable up and down with respect to the θ-axis base, and the substrate support mechanism is provided on the Z-axis base. The screen printer according to 1 or 2. A plurality of rotating shafts provided with screws on the outer peripheral portion to connect the Z-axis base and the θ-axis base; pulleys attached to portions of the rotating shafts protruding above the Z-axis base; and 4. A screen printing machine according to claim 3, further comprising: a motor coupled to a pulley, wherein when the motor is driven, the Z-axis base moves up and down with respect to the θ-axis base. .

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