JPH05299891A - Method for detecting pickup mistake of electronic component - Google Patents

Abstract

PURPOSE:To sense whether there are pickup mistakes at high speed by optical clamping with the light emitter waiting by driving the elevating mechanism during rotation of a transfer head according to data of the thickness of an electronic component registered in a computer memory to adjust the height of a sensor. CONSTITUTION:A transfer head 7 vacuum-chucks and picks up an electronic component in a component supplier 12 during index rotation to transfer it onto a board 6 on an XY table 3. Data of model of electronic component C1 and its thickness W1 are registered on computer program, so that the bottom level L1 is known as well. Then, during driving a motor to adjust the height of a bracket 90 during index rotation of a transfer head 7 makes the light emitter 91 and the light receiver 92 vacuum-chucked in the lower end of a nozzle 8 and waiting in a vicinity of the bottom level L1 of a next approaching electronic component C1; when the electronic component C1 stops, optical sensing is conducted immediately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a pick-up error of an electronic component, and more specifically, to a light-emitting portion and a light-receiving portion provided in a moving path of a transfer head for vacuum-adsorbing an electronic component to a nozzle and transferring it to a substrate. The present invention relates to a method for detecting a pick-up error of an electronic component for detecting the presence or absence of a pick-up error at high speed.

[0002]

2. Description of the Related Art As a transfer head rotates, an electronic component (hereinafter also referred to as a "chip") in an electronic component supply unit is vacuum-sucked by a nozzle to be picked up and mounted on a substrate provided on an XY table. The rotary head type electronic component mounting apparatus has an advantage that chip type electronic components can be mounted on a substrate at a high speed, and is widely used today.

However, since the nozzle picks up an electronic component in the electronic component supply section by vacuum suction at a high speed, a pick-up error is likely to occur. The categories of pick-up mistakes are (a) no chip (when the nozzle cannot vacuum-adsorb electronic components), (b) chip standing (nozzle cannot properly adsorb the upper surface of the electronic component, and the chip is erected and tilted). Case), (c) erroneous chips (when the nozzle picks up an electronic component of a different type mainly due to a misplacement of a parts feeder provided in the electronic component supply unit).

As a means for detecting such a pickup error, the means disclosed in FIGS. 3 and 4 of Japanese Patent Publication No. 3-45919 is known. In this device, two or more optical sensors are vertically arranged in the moving path of the nozzle, and the presence or absence of a pickup error is detected by the presence or absence of light reception by the light receiving portions of these optical sensors.

[0005]

The thickness of electronic parts varies considerably depending on the type (generally 0.5 mm to 10 mm).
mm or more). Therefore, in order to detect the pick-up error of the electronic component by the means disclosed in the above publication, it is necessary to provide an elevating mechanism for the optical sensor and adjust the height of the optical sensor according to the thickness of the electronic component. When the lifting mechanism is configured in this way, it takes time for the optical sensor to move up and down.

On the other hand, as for this type of rotary head type electronic component mounting apparatus, in recent years, an ever-increasing speed has been demanded, and an ultra-high speed one having a cycle time of 0.15 seconds or less has already been proposed. When the elevating mechanism is applied to such an ultra-high speed device, the time for elevating and lowering becomes a dead time, and it becomes difficult to implement the ultra-high speed mounting.

By the way, the chip data such as the type of electronic components to be sequentially mounted on the board and the thickness thereof are known from the computer program, and these chip data are registered in advance in the memory of the computer.

Therefore, the present invention has been made in view of the above circumstances, and a method capable of detecting the presence or absence of a pick-up error of an electronic component at high speed by optical means while coping with the variation in the thickness of the electronic component. The purpose is to provide.

[0009]

To this end, according to the present invention, according to the thickness data of electronic components registered in the memory of a computer, the lifting mechanism is driven during the rotating operation of the transfer head to raise the height of the detection device. By adjusting the height, the light emitting unit and the light receiving unit are made to stand by in the vicinity of the lower surface level of the next electronic component, and the electronic component vacuum-adsorbed by the nozzle arrives and moves between the light emitting unit and the light receiving unit. During the timing when the rotation operation of the mounting head is stopped, it is detected whether the light emitted from the light emitting unit toward the light receiving unit is shielded by the lower part of the electronic component and the presence or absence of light shielding immediately below the electronic component, and the detection is performed. According to the result, it is determined whether or not there is a pickup error in the electronic component.

[0010]

According to the above construction, during the rotating operation of the transfer head, the elevating mechanism is operated so that the heights of the light emitting portion and the light receiving portion are vacuum-sucked by the nozzles to be close to the lower surface level of the next electronic component. Since it is adjusted in advance and put on standby, if electronic parts come between the light emitting part and the light receiving part and the rotation of the transfer head is stopped, the presence or absence of light shielding near the lower part of the electronic parts is immediately detected, It is possible to determine whether or not there is a pickup error. Therefore, the time required for moving the light emitting unit and the light receiving unit up and down according to the thickness of the electronic component does not substantially become the dead time, and high-speed mounting of the electronic component on the substrate can be realized.

[0011]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a perspective view of a rotary head type electronic component mounting apparatus. The configuration of this rotary head type electronic component mounting apparatus has been previously proposed by the applicant of the present application.
This is the same as that disclosed in Japanese Patent No. 61899, and
The structure will be briefly described.

Reference numeral 1 is a main body box, 2 is a rotary head mounted on the bottom of the main body box 1, and 3 is an X table 4.
Is an XY table including a Y table 5 and a Y table 5. 6 is XY
The board 6 is set on the table 3 by the clamp portion 10. The board 6 slides on the XY table 3 in an arbitrary direction J.
It is slid and positioned. On the lower surface of the rotary head 2, a large number of transfer heads 7 are arranged in parallel along the circumferential direction, and each transfer head 7 is provided with a nozzle 8 projecting downward. These transfer heads 7 are index-rotated in the arrow N direction driven by the rotary head 2.

Reference numeral 20 is a drive unit box disposed directly above the rotary head 2 in the box 1, 21 is a drive unit of the drive unit box 20, and 22 is a support frame. The rotary head 2 is index-rotated by the drive of the drive unit 21. The drive unit 21 is a pulse motor, the power of which is transmitted to the transfer head 7 via a transmission path described below, and the transfer head 7 moves up and down with a predetermined stroke. Two
5a is a pulley attached to the output shaft of the drive unit box 20, 25b is another pulley, and 26 is a pulley 25.
The timing belt is tuned to a and 25b, and 27 is the rotating shaft of the pulley 25b. At both ends of the rotary shaft 27, the transfer head 7 is provided at two positions on the supply unit 12 and the XY table 3.
A cam 30 is mounted to raise and lower the. 33
Is a key-shaped lever and swings in the direction of the arrow when the cam 30 rotates. 40 is a tie rod, 50 is a tie rod 4
0 is a pulse motor provided above 0, 51 is a support bracket thereof, 54 and 55 are guides that guide the vertical movement of the tie rod 40, and 56 is a guide that reciprocates in the horizontal direction.

FIG. 2 is a plan view of the rotary head 2. Reference numeral 12 is an electronic component supply section arranged on the opposite side of the XY table 3, and as will be described later, index rotation of the rotary head 2 in the N direction. By the operation and the lifting operation of the transfer head 7 nozzle 8, the electronic component C of the supply unit 12 is transferred to and mounted on the substrate 6. 13 is a supply unit 12 and XY
A recognition device arranged between the tables 3 is composed of an optical system, and detects the rotation angle of the electronic component C vacuum-sucked at the lower end of the nozzle 8 with respect to the axis of the nozzle 8 and A motor (not shown) is driven by the detection signal to rotate the transfer head 7 in the H direction around the axis of the transfer head 7 to correct the rotation angle of the electronic component C sucked by the nozzle 8. Reference numeral 80 denotes an optical detection device arranged on the moving path of the transfer head 7 from the supply unit 12 to the XY table 3. The details will be described with reference to FIGS. 3 and 4.

Reference numeral 81 is a mounting bracket, 82 is a pulse motor mounted on the back surface of the bracket 81, 83 is a cam driven by the pulse motor 82, and 84 is a cam follower that abuts the peripheral surface of the cam 83. Reference numeral 85 is an elevating plate connected to the cam follower 84 via a connecting member 86. The elevating plate 85 is connected to the bracket 81 via a spring member 87 that urges the elevating plate 85 downward. When the cam 83 is rotated by driving the motor 82, the elevating plate 85 moves up and down in the vertical direction P. 60 is a computer, and its memory 6
Chip data is registered in 1 and the rotation of the motor 82 is controlled according to the thickness of the electronic component C. Reference numeral 88 is a guide rail mounted on the front surface of the bracket 81, and 89.
Is a slider mounted on the back surface of the lifting plate 85, and when the motor 82 is driven, the slider 89 moves the guide rail 88.
Go up and down along. The above-described components 82 to 84 form an elevating mechanism of the detection device 80. Reference numeral 90 denotes a support portion attached to the lower end portion of the elevating plate 85, which horizontally protrudes forward, and a light emitting portion 91 and a light receiving portion 92 are provided at the tip portion thereof. In addition, the nozzle 8 that sucks the electronic component
Is passed between the light emitting portion 91 and the light receiving portion 92 by the rotation of the transfer head 7 in the direction of the arrow N. Na is the locus of the nozzle 8.

This apparatus has the above-mentioned structure, and its operation will be described below. In FIGS. 1 and 2, the transfer head 7 is index-rotated in the direction of the arrow N, and the electronic component of the electronic component supply unit 12 is vacuum-sucked and picked up by the nozzle 8 and transferred to the substrate 6 on the XY table 3. .. As shown in FIG. 5, the nozzle 8 that adsorbs the electronic component C1 is attached to the light emitting unit 9
1 and the light receiving section 92, and during the timing when the index rotation operation of the transfer head 7 is stopped, the light emitting section 91
The light is irradiated onto the light receiving section 92 from.

Here, according to the program of the computer 60, the data of the type of the electronic component C1 and its thickness W1 are registered in the memory 61 of the computer 60 and are known. Therefore, the lower surface level L1 of this electronic component C1 is also known. is there. Therefore, by driving the motor 82 and adjusting the height of the bracket 90 during the index rotation operation of the transfer head 7, the light emitting portion 91 and the light receiving portion 92 are vacuum-sucked to the lower end portion of the nozzle 8 and then Optical standby is performed in advance near the lower surface level L1 of the incoming electronic component C1, and when the electronic component C1 stops between the light emitting unit 91 and the light receiving unit 92, optical detection is immediately performed. In this case, the motor 82 is driven to slightly irradiate the light emitting section 91 and the light receiving section 92 in order to irradiate the light a radiated to the lower part of the electronic component C1 and the light b radiated directly below the electronic component C1 twice. Move up and down. This vertical movement distance d
Is a short distance of about 0.5 mm to 1.0 mm, and therefore the time required for this vertical movement is very short, and there is practically no dead time. The light emission from the light emitting unit 91 to the light receiving unit 92 may be performed only when the electronic component arrives, or the light emitting unit 91 may receive the light receiving unit 92.
Alternatively, the reading timing of the light receiving unit 92 may be controlled by previously irradiating the same with light.

As shown in FIG. 5, when the upper light a is shielded by the electronic component C1 and the lower light b is received by the light receiving portion 92, the chip C1 is normally adsorbed and there is no pickup error. It is judged as a thing. Also, as shown in FIG.
If neither of the lights a and b is shielded by the chip C1 and received by the light receiving section 92, it is determined that the chip is standing. Further, although not shown, when both the lights a and b are received by the light receiving section 92, it is determined that there is no chip.

Next, as shown in FIG. 7, when a thick electronic component C2 having a thickness W2 arrives, the motor 82 is driven to lower the light emitting portion 91 and the light receiving portion 92 in advance to near the lower surface level L2. Then, it is made to stand by and the presence / absence of a pickup error is determined by the same method as that shown in FIGS. As described above, this method focuses on the fact that the lower surface level L of the electronic component C is known in the program of the computer 60, and the light emitting unit 91 and the light receiving unit 92 come next during the index rotation operation of the transfer head 7. Electronic component C
Since it is made to stand by in the vicinity of the lower surface level L in advance, the time required for the lifting operation of the light emitting section 91 and the light receiving section 92 does not become a dead time, and the electronic component C can be mounted on the substrate 6 at a high speed. Become. Needless to say, it takes time to move the distance d up and down, but since the distance d is extremely short as described above, it has little or no effect on the cycle time.

8 and 9 show another embodiment of the present invention. In this structure, a supporting portion 90 is provided with two upper and lower light emitting portions 91 and a light receiving portion 92 with a narrow vertical distance d of about 1 mm. Similar to the one shown in FIG. 5 to FIG. 7, this one also drives the motor 82 during the index rotation operation of the transfer head 7 so that the light emitting portion 91 and the light receiving portion 92 come to the lower surface of the electronic component C. Although it is made to stand by in the vicinity of the level L in advance, there is an advantage that the vertical movement of the distance d becomes unnecessary by providing the light emitting portion 91 and the light receiving portion 92 in the upper and lower portions.

[0022]

As described above, according to the present invention, the lifting mechanism is driven during the index rotation operation of the transfer head,
The light emitting part and the light receiving part are preliminarily waited in the vicinity of the lower surface level of the electronic component coming next by being adsorbed by the nozzle, and the electronic part comes between this light emitting part and the light receiving part and the rotation operation of the transfer head is stopped. By irradiating light from the light emitting unit to the light receiving unit during the timing, the presence or absence of light shielding by the lower part of the electronic component and the presence or absence of light shielding immediately below the electronic component are detected,
Since the presence or absence of a pick-up error of the electronic component is determined according to the detection result, the time required for the lifting operation of the light emitting unit and the light receiving unit does not become a dead time,
It is possible to detect the presence or absence of a pick-up error at a high speed while coping with the variation in the thickness of the electronic component, and it is possible to realize a higher mounting speed of the rotary head type electronic component mounting device.

[Brief description of drawings]

FIG. 1 is a perspective view of a rotary head type electronic component mounting apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a rotary head type electronic component mounting apparatus according to an embodiment of the present invention.

FIG. 3 is a perspective view of a detection device according to an embodiment of the present invention.

FIG. 4 is a side view of the detection device according to the embodiment of the present invention.

FIG. 5 is a front view during detection of a pickup error according to the embodiment of the present invention.

FIG. 6 is a front view during detection of a pickup error according to the embodiment of the present invention.

FIG. 7 is a front view during detection of a pickup error according to the embodiment of the present invention.

FIG. 8 is a front view during detection of a pickup error according to another embodiment of the present invention.

FIG. 9 is a front view during detection of a pickup error according to another embodiment of the present invention.

[Explanation of symbols]

 3 XY table 6 substrate 7 transfer head 8 nozzle 12 electronic component supply unit 60 computer 61 memory 82 lifting mechanism (motor) 83 lifting mechanism (cam) 84 lifting mechanism (cam follower) 90 detection device 91 light emitting unit 92 light receiving unit C electronic component L Bottom level W Electronic component thickness

Claims (1)

[Claims] 1. A transfer head is rotated, and an electronic component of an electronic component supply unit is vacuum-sucked and picked up by a lower end portion of a nozzle, and a light emitting unit and a light receiving unit provided in a moving path of the transfer head are attached. In the mounting method of an electronic component, the electronic device is mounted on a substrate provided on an XY table after the electronic component is detected by a detection device provided therein, and the thickness of the electronic component registered in a memory of a computer. By adjusting the height of the detecting device by driving the elevating mechanism during the rotating operation of the transfer head according to the data of 1., the light emitting part and the light receiving part are vacuum-adsorbed to the lower end part of the nozzle, During the timing at which the electronic component vacuum-adsorbed by the nozzle arrives between the light-emitting part and the light-receiving part and the rotation operation of the transfer head is stopped by waiting in advance near the lower surface level of the incoming electronic part. , The presence or absence of shading due to the lower portion of the electronic part of the light emitted toward the light receiving unit from the light emitting portion,
A method for detecting a pick-up error of an electronic component, comprising detecting the presence or absence of light shielding immediately below the electronic component and determining whether or not there is a pick-up error of the electronic component according to the detection result.