JPH06224598A - Method for detecting height of mounting position in chip device mounting apparatus - Google Patents

Abstract

(57) [Summary] [Purpose] In a chip component mounting device that mounts a chip component by suction on a suction nozzle by vacuum negative pressure and moves it to the mounting position on the circuit board, the height of the mounting position can be adjusted with an inexpensive structure. A detection method that can accurately detect is provided. [Structure] Before executing the mounting of the chip component, the production data including the mounting position data on the circuit board is read (step S1), and the suction nozzle is moved to the mounting position based on the data while the chip component is not sucked. Yes (S2). Then, while lowering the suction nozzle, the degree of vacuum in the suction nozzle is detected and monitored by the air pressure sensor (S3, S4 to S4).
(7 loop), when the degree of vacuum rises, the height of the suction nozzle at that time is detected as the height of the mounting position of the circuit board and stored in the memory (S8). In this way, the height of the mounting position can be accurately detected by utilizing the air pressure sensor conventionally provided in the chip component mounting apparatus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip component mounting apparatus for adsorbing a chip component by a vacuum negative pressure to a suction nozzle and moving the chip component to a mounting position of the circuit substrate for mounting the height of the mounting position of the circuit substrate. The present invention relates to a method for detecting the height of a mounting position of a chip component mounting device to be detected.

[0002]

2. Description of the Related Art In the above-mentioned chip component mounting apparatus, so-called chip mounter, a suction mechanism 2 for sucking the chip component 1 by a vacuum negative pressure is provided in the head mechanism shown in FIG. The nozzle 2 is a θ motor (nozzle rotation motor) 4
Can be rotated at an arbitrary angle around the axis of the nozzle itself via the timing belt 5 by driving the pinion 7 by driving the Z-axis motor (nozzle lifting motor) 6.
The rack 8 and the linear guide 9 can be used to move up and down. Then, the head mechanism drives the X-axis motor and the Y-axis motor of an XY moving mechanism (not shown) in the X-axis direction and the Y direction.
The chip component 1 that is moved in the axial direction and supplied by a feeder (not shown) is adsorbed by the nozzle 2 and is moved to a predetermined position on a circuit board (not shown) and mounted.

By the way, the circuit board on which the chip parts are mounted has a height difference due to warpage and waviness, which becomes larger as the circuit board becomes larger. To cope with this, the conventional chip mounter employs a structure in which the tip of the suction nozzle is used as a damper to project from the nozzle body by an elastic force and can be pushed against the elastic force. For example, as shown in FIG.
When the allowable range of the height difference of 0 is ± 2 mm, the moving stroke of the tip end portion 2a of the suction nozzle 2 by the damper mechanism is 4 mm. The height of the main body of the suction nozzle 2 when mounting the chip component 1 on the circuit board 10 is
It is assumed that the nozzle tip 2a is pushed upward by 2 mm at the original height of 0 (center in FIG. 2), and the nozzle tip 2a is pushed (left side in FIG. 2) or projected (FIG. 2) from that height. (On the right side of FIG. 3), the circuit board 10 can be mounted according to the height difference.

[0004]

However, there are the following two problems in the above-mentioned method of dealing with the height difference of the circuit board by the damper mechanism of the suction nozzle.

(1) When the amount of push-in of the nozzle tip portion during mounting is large, the circuit board is also strongly pressed. Therefore, when the nozzle is raised after mounting the chip component, the circuit substrate acts as a spring to lift the chip component. It may end up.

(2) Similarly, when the amount of pushing of the nozzle tip portion at the time of mounting is large, the pressure on the chip component by the nozzle tip portion also becomes large, and especially when the pushing amount is maximized as shown on the left side of FIG. The pressure is also maximum, and the chip component may crack depending on the material.

To solve this problem, it is necessary to accurately detect the height of the mounting position of the circuit board and accurately control the height of the mounting position. However, there is a problem in that the provision of a new means for detecting the height of the mounting position on the chip mounter has a negative cost effect.

Therefore, an object of the present invention is to provide a mounting position height detecting method capable of accurately detecting the mounting position height of a chip component with a configuration that can be realized at low cost in this type of chip component mounting apparatus. is there.

[0009]

In order to solve the above-mentioned problems, according to the present invention, a suction nozzle for sucking a chip component by vacuum negative pressure and moving it to a mounting position on a circuit board,
In a chip component mounting apparatus having a detection means for detecting the degree of vacuum in the suction nozzle, a vacuum negative pressure is applied to the suction nozzle while the chip component is not suctioned to mount the suction nozzle on the circuit board. Moving to a position and detecting the degree of vacuum in the suction nozzle while lowering the suction nozzle by the detecting means, and monitoring the height of the suction nozzle when the degree of vacuum in the suction nozzle rises. The height of the mounting position is detected by detecting the height of the mounting position.

[0010]

According to such a method, the height of the mounting position of the circuit board can be accurately determined by the structure which can be realized at a low cost by utilizing the means for detecting the degree of vacuum in the suction nozzle conventionally provided in the chip component mounting apparatus. Can be detected.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a chip component mounting apparatus adopting the mounting position height detecting method according to the present invention will be described below with reference to the drawings.

First, FIG. 3 shows the configuration of the main part of the head mechanism of the chip component mounting apparatus according to the embodiment. This Figure 3
2, the head mechanism of this embodiment is provided with two suction nozzles. Of course, only one is sufficient, but two can mount at higher speed. The structure of the main body of the nozzles 2 and 2'is a simple structure in which the vent holes 2b and 2b 'are vertically penetrated as shown in FIG. 4, and the conventional damper mechanism is not provided, and the tip end is not provided. The parts 2a, 2a 'are fixed.

Further, in FIG. 3, the nozzles 2 and 2'can be rotated at arbitrary angles via the gear 11, the timing belt 5, and the gears 12 and 12 'by driving the .theta. Also, two Z-axis motors 6,
The nozzles 2 and 2'can be separately moved up and down via the pinions 7 and 7'and the racks 8 and 8'by driving of 6 '. Although not shown, the motor 4,
Encoders 6 and 6'are attached to detect the respective rotation amounts.

On the other hand, the nozzles 2 and 2'include a vacuum generator 1
The air tubes 13, 13 'connected to 5, 15' are connected. Solenoid valve 1 for vacuum generators 15 and 15 '
A strong pressure is applied from a pressure source (not shown) via 6, 16 '. When the solenoid valves 16 and 16 'are closed, the air tube 1 is generated by the vacuum generated by the vacuum generators 15 and 15'.
The air pressure in 3, 13 'is reduced, and the negative pressure allows the nozzles 2, 2'to inhale and adsorb chip components. In addition, the solenoid valves 16 and 1 in the state where the chip parts are adsorbed
When 6'is opened, the air pressure in the air tubes 13, 13 'is pressurized, and the chip parts are separated from the nozzles 2, 2'.

Further, the nozzles 2, 2'and the vacuum generator 15,
Air pressure sensors 14, 14 'for detecting the vacuum air pressure in the air tubes 13, 13' between 15 ', that is, for detecting the vacuum air pressure in the nozzles 2, 2'communication with the tubes 13, 13'. Are provided, and each output is guided to an A / D converter described later.

Next, FIG. 5 shows the configuration of the control system of the apparatus of this embodiment. In FIG. 5, reference numeral 17 is a CPU including a microprocessor for controlling the entire apparatus.
A memory 18 is connected to the CPU 17. Memory 1
Reference numeral 8 includes a ROM and a RAM. The ROM stores data such as a control program executed by the CPU 17, and RA
In M, as the production data, the data of the circuit board on which the chip component is mounted, the data of the chip component to be mounted, the X-axis and Y-axis coordinate data of the suction position and mounting position of the chip component, and the like are stored.

On the other hand, reference numeral 29 in FIG. 5 is a head mechanism having the structure of FIG. 3 described above, which is driven by the X-axis motor 23 and the Y-axis motor 24, respectively.
Moved along 1. X-axis motor 23 and Y-axis motor 2
The drive control of No. 4 is performed by the CPU 17 via the XY-axis pulse generator 21 and the XY-axis servo driver 22. That is, the CPU 17 outputs a signal for instructing the amount of movement in the X-axis direction and the Y-axis direction in which the head mechanism 29 should be moved, to the XY-axis pulse generator 21, and in response to this, X
The Y-axis pulse generator 21 outputs a drive pulse according to the amount of movement in the X-axis and Y-axis directions to the XY-axis servo driver 22, and the driver 22 controls the drive current of the X-axis motor 23 and the Y-axis motor 24 accordingly. Then, both motors 23 and 24 are driven. The rotation amounts of the encoders 23a and 24a attached to the two motors 23 and 24 are fed back to the driver 22.

The above-mentioned drive control of the Z-axis motors 6 and 6'of the head mechanism 29 is similarly performed by the CPU 17 via the Z-axis pulse generator 25 and the Z-axis servo drivers 27 and 27 ', and the .theta. Drive control is similarly performed via the stepping driver 26.

Further, the air pressure sensor 1 of the head mechanism 29
The analog output signals 4 and 14 'are A / D converted by the A / D converter 20, and the resulting digital signal is input to the CPU 17 via the input / output port 19. As a result, the CPU 17 can recognize the air pressure of the vacuum degree in the suction nozzles 2, 2 '.

Based on the above configuration, in the present embodiment, in the tri-run mode before the mounting of the chip component, in the state where the cream solder or the component adhesive is not attached to the circuit board to be mounted, The height of each mounting position of the circuit board is detected. This detection is performed by the air pressure sensor 1
4 and 14 'are used. The detected heights of the respective mounting positions are stored in the memory 18, and the heights of the respective mounting positions are controlled to the heights corresponding to the stored data when the mounting is executed.

The details of the operation for detecting the height of the mounting position will be described with reference to FIG. FIG. 6 shows a flow chart of the control of the CPU 17 for performing the detection operation.

To detect the height of the mounting position, first, the CPU 17 causes the above-mentioned data of the circuit board and the chip component, and the data of the suction position and the mounting position of the chip component (X
The production data including the axis and Y-axis coordinate data) is read into the RAM of the memory 18 from the outside (step S in FIG. 6).
1). The number of mounting positions per board is usually 100.
It is 10,000 points.

Next, the X-axis motor 23 and the Y-axis motor 24 are driven in accordance with the X-axis and Y-axis coordinate data of one of the mounting positions in the read production data, and the head mechanism 29 is moved. The suction nozzle 2 is moved to the above mounting position (step S2). Here, the suction nozzle 2 is moved in a state where no chip component is mounted. Further, the vacuum generator 15 is driven and the electromagnetic valve 16 is closed so that a negative vacuum pressure is applied to the nozzle 2.

Next, assuming that the allowable range of height difference due to warpage or undulation of the circuit board on which the chip parts are mounted is ± 2 mm, the suction nozzle 2 is driven by the Z-axis motor 6 to have a height of +2 mm above the circuit board (circuit board. If there is no warp or undulation, the distance between the tip of the suction nozzle 2 and the top surface of the circuit board is 2 mm.
It is lowered until the height becomes (step S3).
Here, the height of the mounting position of the circuit board may be 2 mm higher than it should be and the tip of the nozzle 2 may come into contact with the circuit board due to the warp or undulation of the circuit board.

Next, the air pressure sensor 14 detects the air pressure in the air tube 13, that is, the air pressure indicating the degree of vacuum in the ventilation hole 2b of the suction nozzle 2, and the detection result is A / D.
Sampling is performed via the converter 20 and the input / output port 19 (step S4).

Next, it is determined whether the degree of vacuum in the suction nozzle 2 has risen based on the sampled air pressure. Here, when the tip of the nozzle comes into contact with the substrate, the degree of vacuum in the suction nozzle 2 rises rapidly as shown in FIG. That is, FIG.
The solid line curve A and the broken line curve B are +0.7 mm and -1.2 mm, respectively, with respect to the original height when there is no waviness or warpage in the mounting position of the board. Shows the change in the degree of vacuum depending on the height of the nozzle tip (the height based on the original height of the substrate). In the case of A, the height of the nozzle tip is +0.7 mm, and when the nozzle tip comes into contact with the substrate, the vacuum level rises sharply. In the case of B, the height of the nozzle tip is -1.2 mm and the nozzle tip is The vacuum level rises sharply when it contacts the substrate. Therefore,
Here, determining whether the vacuum degree has risen means determining whether the nozzle tip has contacted the circuit board, and the height of the nozzle tip at the rising edge of the curve of the change in the vacuum degree is determined by mounting the circuit board. The height of the position.

When it is determined that the degree of vacuum has risen as described above and the degree of vacuum has not risen, that is, when the nozzle is not in contact with the substrate, the Z-axis motor 6 is driven by one step, and the nozzle 2 is moved by 1. It is lowered by a distance corresponding to a step (step S6). Of course, the distance for this one step is
The value is significantly smaller than the allowable range of height difference due to undulations and warpage of the board.

Next, the height of the nozzle tip is the upper surface of the substrate-2 m.
It is determined whether it is lower than m (step S7). This is a case where, for example, in the case where there is no substrate due to an operation error or the like, no matter how much the nozzle is lowered, the degree of vacuum does not rise, and for example, -2 mm is set as the limit value when lowering the nozzle. Then, if it is less than -2 mm, error processing such as notifying the operator that there is no substrate (step S12) is performed, and then the process ends, but if greater than -2 mm, return to step S4. , Steps S4 to S7
The process of is repeated.

By repeating steps S4 to S7, the nozzle 2 is sequentially lowered by one step until the rise of the degree of vacuum in the nozzle 2 is detected. And
When the rise of the degree of vacuum is detected, the height of the tip of the nozzle 2 at that time is taken as the height of the mounting position, and the Z-axis coordinate data is associated with the X-axis and Y-axis coordinate data of the mounting position. The data is stored in the RAM of the memory 18 (step S8).

Next, the X-axis and Y-axis coordinate data of the next mounting position in the production data is selected (step S9).

Subsequently, it is determined whether or not the next data to be selected has disappeared, that is, whether or not the height detection in steps S4 to S8 has been completed for all the mounting position data in the production data (step). S10), if not completed, the process returns to step S2, and the height of the next mounting position is detected by repeating steps S2 to S9.

When the height detection of all the mounting positions is completed, the production data including the detection data of the heights of all the mounting positions are saved in an external storage device such as a hard disk device or a floppy disk device.

As described above, according to this embodiment, the heights of all the mounting positions can be accurately detected and stored before the chip components are mounted. When the mounting is executed, the height of each mounting position can be accurately controlled by controlling the height of each mounting position to the memorized height described above, and it is possible to accurately control the height of the mounting position. No problems such as rising or cracking of chip parts occur, circuit board warpage,
It can be mounted without any problems in response to undulations. Moreover, since the air pressure sensor used for height detection is conventionally provided for controlling the operation of this type of chip mounter, the present embodiment does not increase the cost of hardware, and the structure shown in FIG. It can be easily realized only by changing the control program of the ROM for executing the control of the flowchart.

[0034]

As is apparent from the above description, according to the method for detecting the height of the mounting position of the chip component mounting apparatus of the present invention, the degree of vacuum in the suction nozzle conventionally provided in the chip component mounting apparatus is high. It is possible to accurately detect the height of the mounting position of the circuit board with a configuration that can be realized at low cost by using the detection means of
By accurately controlling the height of the mounting position of the circuit board based on this detection result in the chip component mounting device,
The excellent effect that the chip components can be mounted without any trouble in response to the height difference due to the warp or undulation of the circuit board is obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of a head mechanism of a chip mounter.

FIG. 2 is an explanatory diagram of the operation of the damper mechanism of the suction nozzle for dealing with the warp and undulation of the circuit board in the conventional chip mounter.

FIG. 3 is an explanatory diagram showing a configuration of a head mechanism of a chip mounter to which the method of the present invention is applied.

FIG. 4 is an enlarged perspective view of a suction nozzle in FIG.

FIG. 5 is a block diagram showing a configuration of a control system of a chip mounter to which the method of the present invention is applied.

FIG. 6 is a flowchart of a control for detecting the height of a mounting position by the CPU of the control system.

FIG. 7 is a diagram showing changes in the degree of vacuum in the suction nozzle with respect to the circuit board at the time of the detection, depending on the height of the suction nozzle.

[Explanation of symbols]

 1 chip parts 2, 2'suction nozzle 4 θ motor 6, 6'Z-axis motor 14, 14 'air pressure sensor 15, 15' vacuum generator 16, 16 'solenoid valve 17 CPU 18 memory 23 X-axis motor 24 Y-axis motor 29 head mechanism

Claims (1)

[Claims] 1. A chip component mounting apparatus comprising: a suction nozzle that sucks a chip component by vacuum negative pressure to move it to a mounting position on a circuit board; and a detection unit that detects a degree of vacuum in the suction nozzle. A vacuum negative pressure is applied to the suction nozzle to move the suction nozzle to the mounting position of the circuit board in a state where the chip component is not sucked, and the vacuum degree in the suction nozzle is reduced while lowering the suction nozzle. The mounting position of the chip component mounting device characterized in that the height of the suction nozzle when the degree of vacuum in the suction nozzle rises is detected as the height of the mounting position of the circuit board by detecting and monitoring by the detection means. Height detection method.