JPH0324079B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a method for mounting electronic components onto a printed circuit board and an apparatus used to carry out the method.

Conventional technology Equipment for mounting electronic components onto printed circuit boards includes
As described in the specification of Japanese Patent Application No. 60-281596 filed by the applicant of the present invention, this device is configured to include an electronic component holding device and a printed circuit board supporting device; The component holding device includes a suction nozzle that suctions the electronic component with a vacuum, and the suction nozzle is positioned directly above the electronic component mounting location on the printed circuit board and is lowered to mount the electronic component on the printed circuit board. The printed circuit board supporting device supports the printed circuit board using a table that is moved by a moving device, and by moving the table, the printed circuit board is placed in a predetermined position, that is, the place where the electronic component is mounted is placed in the suction nozzle. It is supposed to be positioned directly below.

In addition, the printed circuit board supporting device supports the printed circuit board at a predetermined position on a table, and the electronic component holding device supports the electronic component holding device by moving the suction nozzle in a direction parallel to the board surface of the printed circuit board. An electronic component mounting device or an electronic component holding device configured to be positioned directly above a component mounting location is moved toward an electronic component mounting location on a printed circuit board with a suction nozzle suctioning an electronic component. There is also an electronic component mounting device that is lowered while mounting the electronic component onto a printed circuit board.

Conventionally, in this type of electronic component mounting equipment,
The distance in the vertical direction between the descending start position of the suction nozzle and the printed circuit board is constant, and the downward stroke of the suction nozzle is constant, and these are not adjusted.

Problems to be Solved by the Invention As a result, various problems have arisen as described below.

For example, if the electronic component is tall and the distance between the suction nozzle and the printed circuit board is small, a problem arises in that the tall electronic component cannot be mounted. In this case, it is possible to mount tall electronic components by increasing the distance between the suction nozzle and the printed circuit board, but in this case, even when mounting low-height electronic components, the suction nozzle must be moved with a large stroke. The mounting efficiency deteriorates as the mounting surface has to be lowered.

In addition, in the electronic component holding device, in order to securely mount the electronic component on the printed circuit board, the downward stroke of the suction nozzle is made larger than the distance between the electronic component and the printed circuit board that are attracted by the suction nozzle, and the distance between the suction nozzle and the printed circuit board is In many cases, an elastic member is provided between the suction nozzle and the suction nozzle holding member, or between the tip of the suction nozzle and the main body, and the excess downward stroke is absorbed by the flexure of the elastic member. In that case, when mounting multiple types of electronic components with different heights on a printed circuit board, the downward stroke of the suction nozzle must be set to match the electronic components with small heights. If the height is high, the stroke absorbed by the elastic member will be large. The descending distance of the suction nozzle is smaller than the descending distance when the electronic component is short, and the amount of deflection of the elastic member increases to absorb this difference, which increases the pressing force applied to the electronic component. This may cause damage to the electronic components, and when the electronic components are mounted on the printed circuit board, the printed circuit board will be deflected, resulting in increased vibration, which may cause the electronic components to be misaligned after mounting. .

Furthermore, if the suction nozzle is moved up and down by a push-down device equipped with a cam, and the descending speed is fast at the beginning of the descent, but the descending speed is slow when the electronic component comes into contact with the printed circuit board, If the component is tall, the electronic component will collide with the printed circuit board at high speed, and the impact generated upon contact will be large, increasing the risk of damage to the electronic component, printed circuit board, etc.

Means for Solving the Problems The present invention has been made to solve the various problems mentioned above, and the first method invention is to lower a suction nozzle that has suctioned an electronic component at its lower end, and to remove the electronic component. When mounting electronic components on the top surface of a printed circuit board, if the electronic components are high, move the table supporting the printed circuit board to a lower position than when the electronic components are low. By moving, the descending distance of the suction nozzle for mounting the electronic component on the printed circuit board is made almost constant regardless of changes in the height of the electronic component.

In addition, in the second method invention, when the height of the electronic component is high, the nozzle holding member that holds the suction nozzle so that it can be raised and lowered is moved to a higher position than when the height of the electronic component is low. By doing so, the descending distance of the suction nozzle for mounting the electronic component on the printed circuit board is made substantially constant regardless of changes in the height of the electronic component.

The invention of the device includes: (a) an electronic component holding device including a suction nozzle that is lowered with the electronic component suctioned at the lower end and attaches the electronic component to the electronic component attachment location on the top surface of the printed circuit board; b) In an electronic component mounting apparatus equipped with a printed circuit board support device that supports a printed circuit board with a table, the table is supported by the table support member in a manner that is immovable in the horizontal direction and movable in the vertical direction; By providing an actuator between the table support member and the table support member to raise and lower the table relative to the table support member, and by controlling the actuator, the height of the electronic component to be mounted is higher than that of the lower height. The present invention is characterized in that a height control device for moving the table to a lower position is provided.

Functions and Effects As in the method according to the present invention, if the descending distance of the suction nozzle is kept almost constant regardless of changes in the height of the electronic component, the height can be increased while avoiding a decrease in the mounting efficiency of electronic components with low height. This makes it possible to mount electronic components with a high level of performance.

In addition, if the extra downward stroke of the suction nozzle is absorbed by the elastic member, the downward stroke of the suction nozzle is kept almost constant, so the amount of deflection of the elastic member becomes almost constant, and the electronic parts are printed. Since the printed circuit board is not pressed with an excessive pressing force, there is no risk of damage or the like, and the printed circuit board is less bent, resulting in less vibration, and there is no risk of misalignment of electronic components. By reducing the deflection of the printed circuit board, it is possible to obtain the effect that the supporting device for the printed circuit board can be simple.

Furthermore, when the suction nozzle is moved up and down by a push-down device equipped with a cam, the impact when tall electronic components come into contact with the printed circuit board is small, and there is no risk of damage to the electronic components. do not have.

In particular, according to the first method invention and apparatus invention, the effect that the distance between the printed circuit board and the suction nozzle can be easily changed is obtained compared to the case where the height of the suction nozzle is adjusted. Since the electronic component holding device including the suction nozzle usually has many moving parts, it is difficult to adjust the height of the suction nozzle in a manner that does not interfere with the operation of these moving parts. However, when adjusting the height of the table that supports the printed circuit board, there are fewer such problems.

Further, according to the second method invention, there is an advantage that not only problems when mounting electronic components on a printed circuit board but also problems when receiving electronic components from an electronic component supply device can be solved at the same time. If the electronic components are of different heights, the same problems may occur when receiving the electronic components as when installing them.
By changing the height of the suction nozzle by changing the height of the nozzle support member, the descending distance of the suction nozzle relative to both the printed circuit board and the electronic component supply device can be made almost constant, and the problem can be solved at the same time.

Embodiments Hereinafter, embodiments of the method and apparatus according to the present invention will be described in detail based on the drawings.

1 and 2 show a printed circuit board support device 2 constituting an electronic component mounting device which is an embodiment of the device according to the present invention. This support device 2 supports the printed circuit board 4 and positions it at a predetermined position.Although not shown, a printed circuit board loading device and a printed circuit board unloading device are provided on both left and right sides in the figure. These loading devices and unloading devices are
It has the same configuration as the loading device and unloading device described in Publication No. 61-168299, and the width (dimension in the direction perpendicular to the printed circuit board feeding direction) is adjustable, and it can handle multiple types of prints of different sizes. It is designed to be able to transport substrates.

Electronic components are mounted on the printed circuit board 4 by an electronic component holding device 8 shown in FIG. This holding device 8 is based on the Utility Application filed in 1983 by the present applicant.
It has almost the same configuration as the holding device according to No. 51512, and will be briefly explained based on the drawings.

In the figure, 10 is a rotating body, and this rotating body 1
0 is rotatably attached to a frame (not shown) around a vertical axis, and by its rotation, a suction nozzle (described later) can be moved to an electronic component suction position, an electronic component mounting position, etc. Further, the rotating body 10 is provided with a linear slide 12 that is moved in the vertical direction by a drive device (not shown), and a suction tube holder 14 is fixed to this linear slide 12. Adsorption tube holder 1
A suction nozzle 18 is rotatably supported around a vertical axis via a sleeve 20 on an arm portion 16 extending horizontally from the lower end of the suction nozzle 16 .

The suction nozzle 18 includes a main body 22 fitted into the sleeve 20 so as to be non-rotatable and movable in the axial direction, and a suction tube 24 fitted integrally with the main body 22. The suction tube 24 is fixed to the main body 22 with a nut 32, and an air passage 34 is formed in the center thereof. This air passage 34 is
The vacuum hose 38 is connected to the nut 32 in the fitting 4
0, it is connected to a vacuum source (not shown), and as the electromagnetic directional switching valve provided in the vacuum source is switched, the suction tube 24 is connected to the electronic component at the suction section 42 at the tip. Adsorbs and releases 44.

Further, a compression coil spring 46 is disposed between the sleeve 20 and the lower end of the main body 22, so that the large diameter portion 48 of the main body 22 is brought into contact with the upper surface of the sleeve 20. This results in
The electronic component 44 is reliably mounted on the printed circuit board 4 with an appropriate pressing force, and the electronic component 44,
Damage to the suction nozzle 24 and the like is avoided. The downward stroke of the suction nozzle 18 is set so that the electronic component 44 descends slightly below the position where it contacts the printed circuit board 4, but the suction nozzle 18 compresses the spring 46 and presses the electronic component 44 against the sleeve 20. By moving the electronic components 44 and the suction tube 24, damage to the electronic components 44 and the suction tube 24 can be avoided.

In addition, the suction nozzle 18 is rotated by a servo motor 60 through a small diameter gear 52, a medium diameter gear 54, and a drive gear 58, so that a large diameter gear 50 provided on the sleeve 20 is rotated by a servo motor 60.
It is designed so that it can be rotated as well.

Further, a projector 66 is attached to the lower surface of the arm portion 16 by a plurality of brackets 64. The floodlight 66 consists of a diffuser plate 70 fixed to a light emitter 68 in which a plurality of light emitting elements 67 are buried at regular intervals, and the suction tube 24 is formed in the center of the light emitter 68. through hole 7
8 so as to be slidably inserted through the projector 66 so that the suction portion 42 is located in front of the projector 66. The light projector 66 emits light when an imaging device (not shown) takes an image of the posture of the electronic component 44 sucked by the nozzle 18. Based on the image taken by the imaging device, the control device
4, the attitude error Δθ and center position errors ΔX and ΔY are calculated. The attitude error Δθ is corrected by rotating the suction nozzle 18.

The printed circuit board support device 2 includes a table 80 that supports the printed circuit board 4, as shown in FIGS. 1 and 2. This table 8
0 is equipped with an upper frame 82 and a lower frame 84 stacked in the vertical direction, and is moved by an NC slide 88 in the X-axis direction parallel to the movement direction of the printed circuit board and in the Y-axis direction perpendicular to the X-axis direction. I am made to do so. The NC slide 88 includes an X-axis slide 90 that is moved in the X-axis direction and a Y-axis slide 92 that is moved in the Y-axis direction.
By moving 92, table 80 is positioned at a predetermined position within a horizontal plane. The NC slide 88 constitutes a moving device.

A pair of guide rods 9 are attached to the upper frame 82.
4 is fixed. These guide rods 94
is slidably fitted into the Y-axis slide 92 through an opening 96 provided in the lower frame 84, and is slidably fitted into the Y-axis slide 92 through an opening 98 provided in the X-axis slide 90.
It is forced to extend inside. Upper frame 82
is engaged with the Y-axis slide 92 by a guide rod 94, and as the guide rod 94 is raised and lowered by a cylinder 99, it is moved toward and away from the lower frame 84 and slides 90 and 92. Upper frame 82
2, which is spaced apart from the lower frame 84 and located at the same height as the printed circuit board loading device and the printed circuit board unloading device, and a raised position where printed circuit boards are delivered, and a certain distance below the raised position, as shown in FIG. It is moved between the lower frame 84 and the lowered position where electronic components can be mounted without interfering with the loading and unloading devices.

As shown in FIG. 2, the upper frame 82 also includes a fixed support member 100 that supports the printed circuit board 4 at both edges parallel to the feeding direction, a movable support member 102, and a fixed support member 102 for accurately positioning the printed circuit board 4. A main positioning member 104 and a sub-positioning member 106 are provided. These fixed support members 1
00, movable support member 102, main positioning member 10
4. The sub-positioning member 106 is the
It has the same configuration as that described in Publication No. 168299, and will be briefly explained here.

The fixed support member 100 includes a bracket 110 fixed at both ends of one of the two sides parallel to the printed circuit board feeding direction of the upper frame 82 and a fixed guide 11 supported by the bracket 110.
It is equipped with 2. Moreover, the movable support member 102 is
A slide 114 is attached to both ends of the other side of the upper frame 82 and is movable in the Y-axis direction.
and a movable guide 116 supported by these slides 114. Both slides 11
4 are each immovably engaged with the upper frame 82 by a clamp mechanism (not shown), while being disengaged by a clamp release mechanism and allowed to move in the Y-axis direction. , the moving guide 116 and the fixed guide 11 are moved as the widths of the loading device and the unloading device are adjusted.
2 is adjusted according to the width of the printed circuit board 4.

Moreover, the main positioning member 104 and the sub-positioning member 106 each include a positioning pin 120 that fits into a positioning hole provided in the printed circuit board 4,
122, the main positioning member 104 is fixedly provided to the upper frame 82, while the sub-positioning member 106 is provided movably. The sub-positioning member 106 is fitted into a guide rail 124 provided on the Y-axis slide 92, and is usually secured to the guide rail 124 by a clamp member (not shown).
4, while the clamp by the clamp member is released by a clamp release member (not shown) provided on a fixing member separate from the printed circuit board support device, and is held in a fixed position. The upper frame 82 is held by the clamp release member.
By moving it in the X-axis direction, its position can be changed to match the position of the positioning hole of the printed circuit board 4. In addition, 126 is a positioning pin, and the printed circuit board 4 whose both ends are supported by the fixed support member 100 and the movable support member 102
This is provided for positioning a support jig that supports the central portion of the frame from below.

The lower frame 84 is provided to be movable in the vertical direction relative to the Y-axis slide 92, and a height adjustment device 128 for adjusting the height of the table 80 is provided between the lower frame 84 and the Y-axis slide 92. It is provided.

As shown in FIG. 1, a pair of guide rods 130 are fixed to the lower frame 84 so as to extend downward.
is fitted to the Y-axis slide 92 so as to be slidable in the axial direction. The lower frame 84 has the guide rod 1
30 and is engaged with the Y-axis slide 92. The lower frame 84 is also provided with four through holes 132 (see FIG. 2) that extend in the vertical direction, and each through hole 132 has four screw members 134 erected on the Y-axis slide 92.
is inserted. A large diameter flange portion 136 provided at the upper end of the screw member 134 and the lower frame 8
A compression coil spring 140 is disposed between the lower surface of the lower frame 84 and a fixed spring receiver 138, and the lower frame 84 is biased toward the Y-axis slide 92.

The lower frame 84 is further provided with bottomed holes 144 that open downward at positions adjacent to the four locations where the compression coil springs 140 are disposed, as shown in FIG.
4, a piston 146 is fitted airtightly and slidably in the axial direction. A piston rod 148 of this piston 146 is connected to a through hole 15 provided in a guide member 150 fixed to the lower surface of the lower frame 84.
2 so as to be slidable in the axial direction. This guide member 150 is loosely fitted into a bottomed hole 154 provided in the Y-axis slide 92 with an upward opening, and the lower end of the piston rod 148 is supported by a plate 156 fixed to the bottom surface of the bottomed hole 154. .

The lower frame 84 is provided with four passages 160 that communicate the air chamber 158 formed between the bottom of each of the four bottomed holes 144 and the piston 146 with the outer surface of the lower frame 84. An air supply device (not shown) is connected to each passage 160. The air supply device is equipped with an electromagnetic directional switching valve, and the computer that controls the entire electronic component mounting device switches and controls the electromagnetic directional switching valve according to the type of electronic component to be mounted. The air chambers 158 are all connected to an air supply or to the atmosphere. When the air chamber 158 is in communication with the atmosphere, the lower frame 84 is biased by the spring 140 and is positioned in the lowered position where the spring receiver 138 abuts the Y-axis slide 92. In addition, air chamber 15
8, when air is supplied, the lower frame 84 is raised against the biasing force of the spring 140. This rise is caused by the guide member 150 and the piston 14
It is regulated by contacting with 6.

As the lower frame 84 is raised and lowered, the upper frame 82 placed thereon is raised and lowered, and the vertical position of the table 80 with respect to the Y-axis slide 92 is adjusted, so that the table 80 is supported by the upper frame 82. The vertical position of the printed circuit board 4 is changed. 4 compression coil springs 140, piston 146, air chamber 15
8 etc. and the air supply device constitute the height adjustment device 128, and in this embodiment, the adjustment distance, that is, the distance between the raised position and the lowered position, is 3.
mm.

Incidentally, as shown in FIG. 1, adjustment bolts 162 are screwed onto the upper frame 82 at four corners so that the vertical position of the table 80 can be finely adjusted. If the table 80 is tilted in the horizontal plane or if the height of the table 80 is inappropriate, an appropriate lock nut 164 can be used.
After loosening, adjust the table 80 by rotating the adjustment bolt 162 so that the table 80 is horizontal.

Furthermore, in this embodiment, the electronic component supply device is
The carrier tape holding the electronic components is fed one pitch at a time along the length, and the electronic components are supplied to the electronic component holding device with the top surface of the device kept at a nearly constant position regardless of the height. ing.

In the electronic component mounting apparatus configured as described above, the height of the table 80 is adjusted in advance according to the height of the electronic component 44 to be mounted. When mounting low-height electronic components, for example, 0.4 to 1.2 mm, on the printed circuit board 4, the table 80 is positioned in the raised position, and the high-height electronic components,
For example, when mounting a 6 mm electronic component on the printed circuit board 4, it is placed in the lowered position.

Then, the electronic component holding device 8 receives the electronic component 44 from a component supply device (not shown), and mounts the electronic component 44 on the printed circuit board 4 after the position of the electronic component 44 is detected by the imaging device. After the imaging device takes an image, the attitude error Δθ is corrected before the image is moved onto the printed circuit board 4, and the NC slide 88 is moved in the printed circuit board support device 2, so that the center position errors ΔX, ΔY are corrected. In the corrected state, the printed circuit board 4 is positioned so that the electronic component mounting location is located directly below the suction nozzle 18.

The suction nozzle 18 is positioned directly above the electronic component mounting location on the printed circuit board 4 and is lowered to mount the electronic component 44 on the printed circuit board 4.
At this time, the position of the table 80 is adjusted according to the height of the electronic component 44, and if the electronic component 44 is small in height, it is in the raised position and the position between the printed circuit board 4 and the suction nozzle 18 is adjusted. If the distance is small and the electronic component 44 is tall, the above-mentioned distance becomes large in the lowered position, so the downward stroke of the suction nozzle 18 is equal to the height of the electronic component 44 It remains almost constant regardless of height. Therefore, when the electronic component 44 is mounted on the printed circuit board 4, the spring 46 is compressed and a pressing force is applied to the electronic component 44, but even if the electronic component 44 is tall, The pressing force does not become excessive, and damage to the electronic components 44 and the like and misalignment of the electronic components 44 due to vibration of the printed circuit board 4 are avoided.

As is clear from the above description, in this embodiment, the Y-axis slide 92 functions as a table support member, and the screw member 134, spring receiver 138,
A compression coil spring 140, a bottomed hole 144, a piston 146, a guide member 150, etc. are attached to the table 8.
0 relative to the Y-axis slide 92. Further, a passage 160 for supplying compressed air to the air chamber 158 formed by the bottomed hole 144 and the piston 146 and the air supply device work together with a computer that controls the electromagnetic directional control valve of the air supply device to operate the actuator. It constitutes a control device that controls the

Note that in the above embodiment, the table 80 can be adjusted to two positions, the raised position and the lowered position, but it may be made to be able to be adjusted more finely in multiple stages, or it can be adjusted steplessly. You can do it like this.

Furthermore, in carrying out the method according to the present invention,
Instead of adjusting the height of the printed circuit board, the height (lowering start position) of the suction nozzle may be adjusted. In this way, for example, when the suction nozzle suctions electronic components of different heights that are placed on a pallet and supplied, damage to the electronic components can be avoided. By adjusting the height of the suction nozzle, the distance between the suction nozzle and both the pallet and the printed circuit board can be changed at once, and damage to electronic components can be avoided. Further, the heights of both the printed circuit board and the suction nozzle may be adjusted.

Further, in the device and method according to the present invention, the printed circuit board supporting device supports the printed circuit board at a fixed position without moving the table in the X-axis direction or the Y-axis direction, and the electronic component holding device However, an electronic component mounting device or an electronic component holding device configured so that the suction nozzle is moved in a direction parallel to the board surface of the printed circuit board and positioned directly above the electronic component mounting location is not suitable for electronic component mounting. An electronic component mounting device other than the above-mentioned embodiments, such as an electronic component mounting device in which a suction nozzle that has sucked up electronic components is moved to an electronic component mounting location and lowered to mount the electronic component on a printed circuit board, and electronic component mounting using the device It can be applied to

In addition, although not illustrated individually, the present invention can be implemented with various modifications and improvements made to the height adjustment device and the like based on the knowledge of those skilled in the art.

[Brief explanation of drawings]

FIG. 1 is a front view (partially in section) showing a printed circuit board support device of an electronic component mounting apparatus which is an embodiment of the device according to the present invention, and FIG. 2 is a plan view. FIG. 3 is a front view (partially in section) showing the electronic component holding device of the electronic component mounting device. 2: Printed circuit board support device, 4: Printed circuit board, 8: Electronic component holding device, 18: Suction nozzle,
44: Electronic parts, 46: Compression coil spring,
80: table, 82: upper frame, 84: lower frame, 128: height adjustment device, 140: compression coil spring, 146: piston, 15
8: Air chamber.

Claims (1)

[Claims] 1. A method of lowering a suction nozzle that has suctioned an electronic component at its lower end to mount the electronic component at an electronic component mounting location on the top surface of a printed circuit board, when the height of the electronic component is high. By moving the table supporting the printed circuit board to a lower position than when the height of the electronic component is low, the lowering distance of the suction nozzle for mounting the electronic component on the printed circuit board can be reduced. An electronic component mounting method characterized in that the height of the electronic component is almost constant regardless of changes in height. 2. A method of lowering a suction nozzle that has suctioned an electronic component at its lower end to mount the electronic component on an electronic component mounting location on the top surface of a printed circuit board, and when the electronic component is high, the suction nozzle is lowered. By moving the nozzle holding member that can be raised and lowered to a higher position than when the height of the electronic component is low, the lowering distance of the suction nozzle for mounting the electronic component on the printed circuit board can be reduced. An electronic component mounting method characterized by keeping the height almost constant regardless of height changes. 3. An electronic component holding device equipped with a suction nozzle that lowers the electronic component while sucking it and attaches the electronic component to the electronic component mounting location on the top surface of the printed circuit board; and a printed circuit board support that supports the printed circuit board with a table. In the electronic component mounting apparatus, the table is supported by a table support member so as to be relatively immovable in the horizontal direction and relatively movable in the vertical direction, and the table is supported between the table and the table support member. By providing an actuator that moves up and down relative to the member and controlling the actuator,
An electronic component mounting apparatus comprising a height control device that moves the table to a lower position when the height of the electronic component to be mounted is higher than when the height of the electronic component is low.