JPH0566040B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to detecting the holding position of an electronic component in an electronic component holding device that holds the electronic component by suction with a vacuum, gripping with gripping claws, or the like.

2. Description of the Related Art Electronic component holding devices as described above are widely used in devices that automatically mount electronic components onto printed circuit boards.

Japanese Patent Application Laid-Open No. 58-213496 discloses that an electronic component held by this type of electronic component holding device is imaged by an imaging device, and when the holding position of the electronic component deviates from the normal position, rotates the component holding head itself that holds the electronic components,
It has been proposed to substantially eliminate this problem by correcting the position of the printed circuit board on which the electronic component is to be attached.

Problems to be Solved by the Invention However, in the device described in the above-mentioned publication, since the imaging device images the electronic component using reflected light from the electronic component, the surface roughness of the electronic component is It was difficult to detect the position of some electronic components because they were easily affected by the color of the pod. In particular, when a single imaging device images many types of electronic components, there is a problem in that it is difficult to accurately detect the positions of all the electronic components.

Means for Solving the Problem In order to solve this problem, the present invention provides a suction head that includes a suction head main body and a suction tube extending from the suction head body and sucking the electronic component with a vacuum at the tip surface. In an electronic component holding device that holds an electronic component by suction, at least a portion of the suction head body around the suction tube is made of a transparent material, and the electronic component suctioned by the suction tube is illuminated through the portion made of the transparent material. The device is equipped with a light projector, and an imaging device that captures a projected image of the electronic component by light emitted from the projector and passed through a portion made of a transparent material and the periphery of the electronic component.

The simplest arrangement of the above-mentioned projector and imaging device is to coaxially face each other, but it is not essential that they are arranged in this way. By changing the direction of the light by providing a reflecting means such as a prism in the path through which the light passes, it is possible to appropriately change the arrangement of the projector and the imaging device according to the surrounding situation.

Furthermore, in a particularly desirable embodiment, the suction head main body is fixed to a cylindrical member with two transparent plates spaced apart from each other in the axial direction and parallel to each other to form a substantially airtight space inside the cylindrical member. A connecting passage is formed in the cylindrical member to connect the space to the vacuum source, and a through hole is formed in one of the two transparent plates to pass through it in the thickness direction. A suction tube may be inserted into the through hole and fixed.

Operation and Effect When the holding position of an electronic component is detected by detecting the position of a projected image of the electronic component as in the present invention, the position of all kinds of electronic components can be accurately detected. This is because the projected image is not affected by the surface roughness or color of the electronic component. Of course, when using a projected image, it is not possible to know the inner structure surrounded by the outline of the electronic component, but in order to detect the holding position of the electronic component, it is sufficient to accurately detect the outline. Yes, there is no problem.

Furthermore, if at least the part around the suction tube of the suction head main body is made of a transparent material, the electronic components can be illuminated through the transparent material, making it easier to detect the accurate position of the electronic components. , it is possible to obtain a complete projected image of the electronic component without any obstruction. Moreover, since the present invention directly captures the projected image of the electronic component with the imaging device, the structure of the device is simplified and the position detection accuracy can be easily improved.

Furthermore, when changing the direction of light from the projector to the imaging device using a reflecting means such as a prism as described above, the relative positional relationship between the projector and the imaging device can be changed arbitrarily, and the design This has the unique effect of increasing the degree of freedom.

Further, as mentioned above, the suction head main body is composed of a cylindrical member and two transparent plates fixed to the cylindrical member parallel to each other at a distance in the axial direction. The space for connecting the suction tube to the vacuum source is connected to the vacuum source through a connection passage formed in the cylindrical member, and the suction tube is inserted and fixed into the through hole formed on one side of the transparent plate, thereby creating a passage for connecting the suction tube to the vacuum source. An advantage is obtained that the projected image of the image is not captured by the imaging device. In other words, even if a passage connecting the adsorption tube to the vacuum source is formed inside the transparent body, the light will pass through the passage to some extent, so the purpose can be achieved, but the light passing through the transparent body will not pass through the passage. Although it is difficult to completely prevent the projected image of the passage from being captured by the imaging device without avoiding reflection on the circumferential surface, as described above, it is difficult to completely prevent the projected image of the passage from being captured by the imaging device. If you use the space surrounded by as a passageway, you can completely avoid such problems.

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

FIG. 1 is a front sectional view showing the main parts of a mounting device that automatically mounts electronic components onto a printed circuit board. This mounting device is held rotatably around a vertical axis by a main body frame 40. The rotating shaft 50 is provided with a rotating shaft 50. A rotating plate 52 is fixed to the upper end of this rotating shaft 50, and 12 cam followers 54 are attached to the outer circumference of this rotating plate 52 at equal angular intervals, and these cam followers 54 rotate around a horizontal axis. It is adapted to engage with a cam 56. As a result, the rotary plate 52 and the rotary shaft 50 are intermittently rotated by 30 degrees each time the cam 56 rotates once.

An intermittent rotary disk 58 is fixed to the lower end of the rotating shaft 50, and twelve sets of suction head units 60, which are component holding devices, are attached to the intermittent rotary disk 58 at equal angular intervals. All of these adsorption head units 60 have the structure shown in FIGS. 2 and 3. As is clear from Figure 2,
Two pairs of rods 62 are attached to the outer periphery of the intermittent rotary disk 58 in a vertical position and movable in the axial direction, and both ends of the rods 62 are connected to each other by connecting members 63 and 64. There is. A cam follower 65 is attached to the upper connecting member 63, and this cam follower 65 is engaged with a cam 66 shown in FIG. The cam 66 is fixed to the main body frame 40, and has an annular cam groove 6 formed on the outer peripheral surface at an angle with respect to the horizontal plane.
7, the rod 62 is raised and lowered as the intermittent rotary disk 58 rotates. An arm 69 serving as a head holder is fixed to the lower connecting member 64 by a shaft member 68, and a suction head 70 serving as a component holding head is attached to this arm 69.
is installed.

As shown most clearly in FIG. 3, each suction head 70 has a head main body 86 which is made up of a metal cylindrical member 80 and transparent plates 82 and 84 made of glass or synthetic resin fixed to both ends thereof. We are prepared. A substantially airtight space is formed inside the head main body 86, and a vertical through hole communicating with this space is formed in the lower transparent plate 84, and a suction tube 88 is press-fitted into this through hole. has been done. The head main body 86 is fitted into the outer cylinder 90 so as to be non-rotatable and slidable in the axial direction, and is normally held at the lower end position where it abuts against the stopper 94 by a spring 92. The outer cylinder 90 is rotatably and axially slidably fitted into a through hole formed in the vertical direction of the arm 69, and is normally fitted with a spring 9.
6 keeps the flange 98 at the rising end position in contact with the arm 69, and the upper end of the outer cylinder 90 has a
A driven rotating body 102 having an inner circumferential friction surface 100 centered on the center line of the suction head 70, that is, the center line of the suction tube 88, is fixed by screwing.
This driven rotating body 102 and the spring 96 are covered by a cover 104.

The arm 69 is provided with a brake device 110 for preventing rotation of the suction head 70, specifically the outer cylinder 90 and the head body 86. The brake device 110 includes a friction member 112, a lever 114,
It is equipped with a spring 115 and the like. Lever 114
is rotatably attached to the arm 69 by a pin 116 at its intermediate portion, a friction member 112 is fixed to one end, and a spring 115 is installed between the other end and the arm 69. The friction member 112 is fitted into a through hole formed in the arm 69, and its tip is pressed against the outer peripheral surface of the outer cylinder 90 by the biasing force of the spring 115 to prevent the suction head 70 from rotating. There is.

The suction tube 88 is connected to a space formed in the head main body 86 and a connection passage 1 formed in the cylindrical member 80.
17, a connecting passage 118 formed in the outer cylinder 90, a passage 11 formed in the arm 69 and the shaft member 68;
9 and 120, passages 122 and 12 formed in the intermittent rotating disk 58 and rotating shaft 50.
4, and is further connected to a vacuum device (not shown) at a port 128 via a joint 126. A switching valve 130 is provided at the connection between the passages 120 and 122, and when switched by a valve operating device (not shown), the adsorption pipe 88 can be selectively communicated with the vacuum device and the atmosphere. ing.

Each suction head 70 is stopped at 12 positions A to L shown in FIG. 4 as the intermittent rotary disk 58 rotates intermittently. Then, at position A, an electronic component is received from a component supply device (not shown), and at position G, it is mounted on a printed circuit board. Position A is the parts receiving position, and position G is the parts mounting position. Also, position C and position E
A component position detection device 140 and a head rotation device 142 are respectively provided at the positions C and E, respectively, so that position C is a component position detection position and position E is a component position change position. Further, at position D, if the electronic component detected at position C has a different shape from the expected one, the switching valve 130 is switched so that the erroneous electronic component is released from the suction head 70. It's summery. Since the component position detection device 140 detects the outline of the electronic component, it can detect not only the position but also the type of the electronic component.

As is clear from FIG. 5, the component position detection device 140 includes a light projector 146, a prism device 148, and an imaging device 150 assembled to an auxiliary frame 144 fixed to the main body frame 40. The projector 146 is fixed to the auxiliary frame 144 by a bracket 152, and is positioned directly above the suction head 70 stopped at the component position detection position C. The light projected from the light projector 146 passes through the suction head 70 and then passes through the prism device 1.
The direction of the light is changed by 90 degrees by the two prisms 154 of 48, and the light enters the imaging device 150. The imaging device 150 includes a lens 156, and this lens 1
A photographed image of the electronic component W formed on the surface of a solid-state image sensor (not shown) by 56 is converted into a binary signal. The imaging device 150 includes a bracket 160
The bracket 160 is attached to the auxiliary frame 144 by the adjusting screw 162.
By adjusting the focal length, the focal length can be adjusted. Note that 164 is the imaging device 15
0 power unit.

The head rotation device 142 includes a rotary drive body that frictionally engages with the driven rotary body 102 shown in FIG. 3 to rotate it. The rotary driving body has an expanded portion that is expanded radially outward mechanically or by fluid pressure, and this expanded portion is inserted into the driven rotary body 102 and expanded, thereby reducing the frictional force. The suction head 70 is rotated around the center line of the suction tube 88 as the driving rotor rotates. However, since this head rotating device 142 is not essential to understanding the present invention, a detailed description thereof will be omitted.

Next, the overall operation of this electronic component mounting apparatus will be explained. While the suction head 70 stopped at position A (component receiving position) in FIG. The component position including the rotational posture around the center line of the suction head 70 of W is detected, and at position E (component position change head), the head rotation device 142
The suction head 70 is rotated, the rotational posture of the electronic component W around the center line of the suction head is changed, and furthermore, the electronic component W is mounted on the printed circuit board at position G (component mounting position). . Note that if the component position detected at position C includes a deviation between the center line of electronic component W and the center line of suction head 70, immediately before the suction head 70 is stopped at position G, The position of the printed circuit board is corrected by the board positioning device by an amount necessary to eliminate the centerline deviation. Although the operations at each of the above positions are performed simultaneously and in parallel on different suction heads 70, the operations at each position will be described in detail below, focusing on one suction head 70.

When the suction head 70 is stopped at position A, a selected one of the many component supply units of the component supply device is positioned directly below the suction head 70, and the electronic components held in the component supply unit are positioned directly below the suction head 70. The cover tape is peeled off from the holding tape, and the electronic component W can now be taken out. Therefore, in FIG. 3, when the head pressing device driven by a cam device (not shown) comes into contact with the driven rotating body 102 and pushes it down against the biasing force of the spring 96, the head body 86 and The adsorption tube 88 also descends accordingly,
The lower end surface of the suction tube 88 comes into contact with the upper surface of the electronic component W. Although the driven rotating body 102 and the outer cylinder 90 are pushed down thereafter, the head main body 8
6 and suction tube 88 are allowed to remain stationary by compression of spring 92. In this state, the suction tube 88 is communicated with the vacuum device, so the electronic component W is suctioned by the suction tube 88. Next, when the action of the head pressing device is released and the suction head 70 rises, the electronic component W is also sucked. It rises accordingly, and the mounting device finishes receiving the electronic component W from the component supply device.

If the suction head 70 that has received the electronic component W is stopped at the position C in this way, the suction head 7
0 is located between the projector 146 and the prism device 148 as shown in FIG. Therefore, a projected image of the electronic component W is formed on the solid-state imaging device surface of the imaging device 150 by the light projected from the light projector 146. The imaging device 150 converts this projected image into a binary signal and outputs it to a control device (not shown). The control device compares the binary signal with a binary signal indicating the position of the regular electronic component W stored in advance in its own memory, and determines the attitude error Δθ with respect to the regular position of the electronic component W. and center position errors ΔX and ΔY.

After the component position is detected as described above, when the suction head 70 stops at position E, the suction head 70 is located directly below the drive rotary body of the head rotation device 142. Therefore, this driving rotating body is connected to the inner circumferential friction surface 100 of the driven rotating body 102.
By rotating the drive rotor by the servo motor, the suction head 70 is rotated by an angle necessary to eliminate the attitude error Δθ.

After the posture error is removed as described above, when the suction head 70 stops at position G, the printed circuit board is positioned by the printed circuit board positioning device at a position corrected by the center position errors ΔX and ΔY. has been done. Therefore, when the suction head 70 is pressed down by a head pressing device (not shown), the electronic component W held by the suction tube 88 is pressed against a predetermined position on the printed circuit board and fixed by adhesive or the like. In this state, the electronic component W is released from the suction head 70 by switching the switching valve 130 and communicating the suction tube 88 with the atmosphere. After that, when the suction head 70 is raised, the electronic component W can be mounted on the printed circuit board. Complete.

As is clear from the above description, in this electronic component mounting apparatus, the suction head 70 receives the electronic component W, detects the position, changes the position (changes in posture), and mounts the electronic component onto the printed circuit board simultaneously at multiple positions. This reduces cycle time and improves the efficiency of electronic component mounting work.

In addition, since the suction head 70 is made of a transparent material around the center line of the suction tube 88, the light from the projector 146 is transmitted in a direction parallel to the center line of the suction head 70, that is, the center line of the suction tube 88. By doing so, a complete projected image of the electronic component W that is not obstructed by anything can be focused on the solid-state image sensor surface of the imaging device 150, and the position of the electronic component W can be accurately detected. I can do it.

Although one embodiment of the present invention has been described in detail above,
This is literally just an example, and the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing the main parts of an electronic component mounting apparatus equipped with a component holding device (suction head unit) according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of FIG. 1. Figure 3 is the first
FIG. 3 is a front cross-sectional view of the component holding device shown in the figure. FIG. 4 is an explanatory diagram showing the relative positional relationship between each of the component holding devices, the component position detection device, and the head rotation device, and is a sectional view taken along the line 5 in FIG. FIG. 5 is a front view of a component position detecting device which together with the component holding device shown in FIG. 3 constitutes an electronic component holding device with a component position detecting device which is an embodiment of the present invention. 58: Head holder, 60: Adsorption head unit (component holding device), 62: Rod, 63, 6
4: Connecting member, 68: Shaft member, 69: Arm, 7
0: Suction head, 80: Cylindrical member, 82, 84: Transparent plate, 86: Head main body, 88: Suction tube, 9
0: Outer cylinder, 100: Inner peripheral friction surface, 102: Driven rotating body, 110: Brake device, 140: Component position detection device, 142: Head rotation device, 146:
Light projector, 148: prism device, 150: imaging device.

Claims (1)

[Scope of Claims] 1. An electronic component holding device that suctions and holds electronic components using a suction head that includes a suction head main body and a suction tube that extends from the suction head body and that vacuum suctions electronic components at its distal end surface, comprising the steps of: At least a portion of the head body around the suction tube is made of a transparent material, and a floodlight illuminates the electronic components sucked into the suction tube through the portion made of the transparent material; An electronic component holding device equipped with a component holding position detection device, comprising an imaging device that captures a projected image of the electronic component using light that has passed through a material portion and the periphery of the electronic component. 2. The device according to claim 1, wherein a reflecting means for changing the direction of the light is provided on a passage path of the light from the projector to the imaging device, and the projector and the imaging device are disposed non-coaxially. Electronic component holding device. 3. The suction head main body includes a cylindrical member, and two transparent plates fixed to the cylindrical member parallel to each other at an axial distance and forming a substantially airtight space inside the cylindrical member. , including a connection passage formed in the cylindrical member to connect the space to the vacuum source, and a through hole formed in one of the two transparent plates by penetrating it in the thickness direction. The electronic component holding device according to claim 1 or 2, wherein the base end portion of the suction tube is inserted into the through hole and fixed.