JPH0661695A - Floating lead detecting method for component and component mounting machine employing the method - Google Patents

Abstract

PURPOSE:To detect a floating lead of a component accurately and to control component mounting operation based on the detection results. CONSTITUTION:A reference reflector 24 is disposed above the component sucking face of a suction nozzle and a slit beam is projected at a predetermined inclination angle toward the reference reflector and a lead of a component Q obliquely from below. Individual slit beam images RS reflected on the reflector while passing through the gap of the leads and individual slit beam images Rn reflected on the leads are then recognized. The center of gravity is then calculated for each optical image reflected on the reference reflector and the leads, and the center of gravity data of the optical images reflected on the reference reflector is subjected to least square calculation thus determining a height reference line S0. Furthermore, a lead standard line S1 passing through the average value of the center of gravity data of optical images reflected on the leads and extending in parallel with the height standard line is calculated. The distance from the lead standard line S1 to the center of gravity of the optical image reflected on a lead is then compared with a preset allowance of lead floating thus detecting the floating of lead.

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 lead floating of a component held by suction and a component mounting apparatus for transferring the component held by suction and automatically mounting it on a predetermined position on a substrate.

[0002]

2. Description of the Related Art Conventionally, various methods have been proposed as a method for inspecting the leads of a suction-held component and mounting them on a substrate. As an example thereof, Japanese Patent Laid-Open No. 1-32000.
In the gazette, a camera for picking up an image of a part gripped by a robot from below and a laser slit light source having a certain angle with respect to the optical axis of this camera are provided, and a laser slit light is projected onto a part lead to identify the part. The position deviation amount of the reflected light from the lead at the position (standard setting position) and other leads is visually recognized as the lead floating amount. Then, as a result of the recognition inspection, only non-defective products are mounted on the substrate.

[0003]

In such a lead inspection method, the lead at a specific position is set as a standard setting position. Therefore, the recognition error of the lead at the standard position directly affects the lead floating amount, and the lead is erroneously read. The case where it is determined to be a floating defect is conceivable. In consideration of this point, the present invention intends to improve the lead floating judgment accuracy by calculating the standard position of the lead so that the recognition error does not affect as much as possible.

[0004]

According to the present invention, a horizontal reference surface is provided above the component suction surface of the suction nozzle, and slit light is emitted obliquely downward from the reference surface and the leads of the component at a constant inclination angle. Then, the individual slit light image reflected from the reference surface after passing through the gap between the leads and the individual slit light image reflected from the lead are recognized. Then, the barycentric position of each slit light reflection image from the reference surface and the barycentric position of each slit light reflection image from the lead are calculated,
The height reference line is calculated using the least squares method based on the gravity center position data of each slit light reflection image from the reference surface. Furthermore, the average value of the barycentric position data of each slit light reflection image from the lead is passed to calculate a lead standard line parallel to the height reference line, and from this lead standard line, each slit light reflection image of the lead is obtained. The distance to the center of gravity is used as the lead floating amount, and lead floating is detected by comparing with the preset lead floating allowance.

Further, in the present invention, slit light is radiated obliquely from below toward a lead of a component at a constant inclination angle, each slit light image reflected from the lead is recognized, and each slit light reflection from the lead is recognized. The center of gravity of the image is calculated. Then, the lead standard line is calculated using the least squares method from each center-of-gravity position data, and the distance from the lead standard line to the center-of-gravity position of each slit light reflection image from the lead is set as the lead floating amount, which is set in advance. The lead float is detected by comparing with the lead float allowance.

Each of these lead floating detection methods is used in a component mounting apparatus to detect the lead floating of a component while the component held by suction is transferred and mounted at a predetermined position on the board.
The mounting operation is controlled based on the recognition result.

[0007]

[Function] The average value of the barycentric position data of each slit light reflection image from the component lead is set as the lead standard position, and the lead of the part is determined by the displacement amount between the lead standard position and the barycentric position of the slit light reflection image from each lead. Determine floating.
The component determined to have the lead floating is not mounted on the substrate.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a lead floating detection method and a component mounting apparatus using the same according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic plan view showing the main configuration of the component mounting apparatus in this embodiment. The component mounting apparatus 1 includes a plurality of component mounting heads 2 provided at equal intervals on the periphery of an index table that rotates intermittently around a drive shaft 21.
Rotary head part 2 consisting of 3 and component mounting head 2
Component supply unit 3 for supplying components to the component 3, component mounting head 23
X which supports horizontally the substrate P on which the component is to be mounted
It is composed of a Y table portion 4, a loader 5 for feeding the substrate P to the XY table portion 4, and an unloader 6 for receiving the substrate P from the XY table portion 4 and feeding it to the next process. The component supply unit 3 is a component mounting table 30 that horizontally moves to the left and right in the drawing.
And a plurality of component supply cassettes 31 arranged and mounted on this. Then, the component mounting head 23 sucks and holds the component of the component supply unit 3, and the substrate P on the XY table unit 4 is held.
An image pickup unit 7 for picking up an image of a component from below is provided at any intermittent stop position (hereinafter, referred to as a station) during mounting of the component.

Here, the lead floating detection portion, which is the gist of the present invention, will be described in detail. FIG. 2 is a schematic explanatory view showing a slit light imaging state of the imaging unit 7, and FIG. 3 is a schematic explanatory view showing another slit light imaging state of the imaging unit 7.
Comprises a camera 71 and a slit light source 72 arranged on the XY table 70. In this embodiment, the XY table 70 is arranged so that the camera 71 is located directly below the station C as shown in FIG. The camera 71 is fixed vertically on the XY table 70, and the slit light source 72 is fixed to a fixed inclination angle by a support block 73 toward the imaging center of the camera 71 as illustrated.
The slit light is emitted obliquely upward at this inclination angle. Two
Reference numeral 4 denotes a reference reflecting plate detachably attached near the tip of the suction nozzle of the component mounting head 23, and its reflecting surface is horizontal. 8 drives the XY table 70 to drive the camera 7
A control unit for moving 1 and the slit light source 72 to a position corresponding to the size of the component Q sucked and held by the component mounting head in the station C, and 9 is an image recognition unit for recognizing an image captured by the camera 71. Further, the control unit 8 controls the mounting operation based on the recognition result of the image recognition unit 9 such as releasing the suction at the station I and discarding the component without mounting the component in which lead floating is detected. .

The operation of this embodiment will be described with reference to the drawings. The control unit 8 is located at the station A of the rotary head unit 2 and causes the component mounting head 23 to which the reference reflection plate 24 is attached to suck the component Q from a predetermined component supply cassette 31 and pick up the component Q while holding the suction. The table 22 is rotated intermittently to transfer the component mounting head 23 to the station C. Before the component Q arrives at the station C, the control unit 8 sets the XY table 70,
The camera 71 is moved to the slit light imaging position below the component mounting head 23 located at the station C. FIG. 4 shows the slit light imaging state of the camera 71. When the slit light source 72 irradiates the slit light obliquely from below, the camera 71 has two types of slit light reflected light as shown in the upper side of FIG. Capture an image. That is, there are two types: a slit light image group Rn reflected from each lead of the component Q and a slit light image group Rs reflected from the reference reflection plate 24 after passing through the lead gap of the component Q.

When these two types of reflected light image groups of the slit light are input to the image recognition unit 9, the image recognition unit 9 first calculates the center of gravity of each reflected light image, and the reflected light image from the reference reflection plate. From the center-of-gravity position data relating to the group Rs, a linear equation of the height reference line S0 is obtained by the least square method. Then, the average value is calculated from the barycentric position data relating to the reflected light image group Rn from the lead, and the linear equation of the lead standard line S1 parallel to the height reference line S0 is obtained through this average value. When calculating the average value, the average of all the center-of-gravity position data relating to the reflected light image group Rn is once obtained, and the average is calculated again by excluding the data largely deviated from this value and calculating the average again. be able to. The distance from the calculated lead standard line S1 to the barycentric position of each reflected light image from the lead is the floating amount of the lead (in the case of the reflected light image R1,
The lead floating amount is set to h1), and the lead floating amount is judged by comparing with the lead floating allowable amount which is input in advance.

Next, the lead floating detection when the reference reflecting plate 24 is not attached to the component mounting head 23 shown in FIG. 3 will be described. Similarly to the above, the control unit 8 causes the component mounting head 23 located at the station A of the rotary head unit 2 to adsorb and pick up the component Q to transfer the component Q to the station C, and the component Q is transferred to the station C.
XY table 70 is moved before arriving at, and the camera 71 is positioned at the slit light imaging position below the component mounting head 23 located at station C. When the slit light source 72 irradiates the slit light obliquely from below, the camera 7
1 captures the slit light reflected light image as shown in the lower side of FIG. That is, it is the slit light image group Rm reflected from each lead of the component Q.

When the reflected light image group Rm of the slit light is input to the image recognition unit 9, the image recognition unit 9 first calculates the center of gravity of each reflected light image, and reads it from the center of gravity position data by the least square method. The linear equation of the standard line S2 is calculated.
The distance from the calculated lead standard line S2 to the barycentric position of each reflected light image from the lead is taken as the lead floating amount (in the case of the reflected light image R2, the lead floating amount is h2), and the lead floating amount entered in advance The lead floating is judged by comparing with the allowable amount.

In any of the above lead detection methods, the control unit 8 rotates the component mounting head 23 by 90 ° after the image of the lead protruding from one side of the component Q is completed, and similarly performs image recognition. The unit 9 recognizes the position of each slit light reflection image, detects the lead floating amount on the four sides of the component Q, and transmits the detection result to the control unit 8.

Based on the lead floating detection information relating to the component Q received from the image recognition means 9, the control unit 8 moves the XY table unit 4 at the station F to move the component mounting head 23 to the substrate when the lead floating does not occur. It is lowered to a predetermined position on P and the suction of the component Q is released and the component Q is mounted. When the lead floats, the component Q is transferred to the component disposal station I without moving the XY table unit 4, where it is sucked and released and the component Q is dropped into a receiving box (not shown).

In the present embodiment, an example in which the lead floating detection method is applied to a rotary head type component mounting apparatus has been described, but an image pickup unit is also provided in a one-by-one type component mounting apparatus in which the component mounting head 23 moves XY. It can be easily applied as a fixed position.

[0017]

As described above, by averaging the barycentric position data of the reflected light images from the component leads, the lead standard position is obtained in a manner that absorbs the recognition error of each reflected light image, and from each lead position. Since the lead floating of the component is determined by the amount of displacement of the reflected light image up to the position of the center of gravity, the determination accuracy is improved.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a main configuration of a component mounting apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic front view of an image pickup unit in the present embodiment.

FIG. 3 is a schematic front view showing a different operation state of the image pickup unit in the present embodiment.

FIG. 4 is an explanatory diagram of component images captured by an image pickup unit according to the present exemplary embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Component mounting device 2 Rotary head part 23 Component mounting head 24 Reference reflector 3 Component supply part 4 XY table part 7 Imaging unit 70 XY table 71 Camera 72 Slit light source 8 Control part 9 Image recognition part

Claims (4)

[Claims] 1. When a lead of a component sucked and held by a suction nozzle is image-recognized to detect the floating of the lead, a horizontal reference surface is provided above the component suction surface of the suction nozzle. Slit light is radiated from a diagonally downward direction toward the leads of the component at a constant inclination angle, and individual slit light images that are reflected from the reference surface by passing through the gap between the leads and individual slit light reflected from the leads. Recognize the image, the center of gravity of each slit light reflection image from the reference surface,
The barycentric position of each slit light reflection image from the lead is calculated respectively, and the barycentric position data of each slit light reflection image from the reference plane is used to calculate the height reference line using the least squares method, and from the lead The average value of the barycentric position data of each slit light reflection image of, the lead standard line parallel to the height reference line is calculated, from the lead standard line to the barycentric position of each slit light reflection image from the lead A lead floating detection method for a component, wherein the lead floating amount is detected by comparing a lead floating amount with a distance and a preset lead floating allowable amount. 2. A component mounting apparatus for recognizing an image of a lead of a component while transferring the suction-held component and mounting it at a predetermined position on a substrate, and controlling the mounting operation based on the recognition result. A component mounting apparatus characterized by using the lead floating detection method for a component according to claim 1. 3. When the lead of the component sucked and held by the suction nozzle is image-recognized and the floating of the lead is detected, slit light is radiated from a diagonally lower direction toward the lead of the component at a constant inclination angle, Recognize the individual slit light image reflected from the lead, calculate the barycentric position of each slit light reflected image from the lead, to calculate the lead standard line using the least squares method with each barycentric position data, The distance from the lead standard line to the barycentric position of each slit light reflection image from the lead is set as the lead floating amount, and the lead floating is detected by comparing with a preset lead floating allowance. Lead float detection method for parts. 4. A component mounting apparatus for recognizing an image of a lead of a component while transferring the suction-held component and mounting it at a predetermined position on a substrate, and controlling the mounting operation based on the recognition result. A component mounting apparatus characterized by using the lead floating detection method for a component according to claim 1.