JP2000241142A - Circuit part-inspecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly detect failure such as the burnout of light-emitting equipment or the like for coping with the failure by providing a means for detecting the failure of the light-emitting equipment being included into a lighting means according to change in voltage in the conduction circuit of the light-emitting equipment. SOLUTION: Light emitting diodes 10A-10D are mutually connected in series, and are positioned between power supply transistors 91. The transistor 91 forms a current control circuit along with a differential amplifier 92 that is connected to the base, the collector is connected to the light-emitting diode 10D, and a current detection resistor 93 is connected between an emitter and the ground. When one of the light-emitting diodes 10A-10D is burned out, the collector current of the transistor 91 reaches 0. An output voltage Vo of the differential amplifier 92 is increased for returning a detection voltage Vr to an original state, and reaches a saturation voltage. When a reference voltage Vb is set to an appropriate value being smaller than the saturation voltage, a failure signal Sa is outputted from a voltage comparator 94 when the output voltage Vo exceeds the reference voltage Vb.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit component inspection apparatus for inspecting a soldering state of a circuit component, and more particularly to a circuit component inspection apparatus for inspecting the state of a circuit component based on an image obtained by illuminating the circuit component. About.

[0002]

2. Description of the Related Art For example, Japanese Patent Application Laid-Open No. 10-90191 discloses that
A soldering inspection device for inspecting a soldering state of a circuit component is disclosed. This involves illuminating the area including the lead of the circuit component on the circuit board with an illuminating device, obtaining the image with an imaging device, and tracing the outer periphery of a high-luminance continuous area in the obtained image. It detects a soldering failure such as "solder bridge" or "solder chipping" from the length of the solder. In such an inspection apparatus, an error occurs in the inspection result unless the circuit components are illuminated with a constant illuminance. Therefore, there is a method of controlling the light emission amount of a plurality of light emitters of a lighting device using an optical calibration plate or the like so that the illuminance on the circuit board is always constant (for example, Japanese Patent Application Laid-Open No. Hei 8-152311).

[0003]

However, if one of the light-emitting devices is short-circuited or disconnected, the light-emitting amount of the entire illuminating device is greatly reduced. It is not possible to illuminate with proper illuminance, and it is necessary to take measures such as stopping inspections.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a circuit component inspection apparatus capable of promptly responding by quickly detecting a defect such as disconnection of a light emitting device of a lighting device. Aim.

[0005]

In order to achieve the above object, according to the present invention, there is provided an illuminating means (5) for illuminating a circuit component (1), and an imaging means for obtaining an image of the illuminated circuit component (1). 8) and processing the obtained image to obtain a circuit component (1)
In the circuit component inspection apparatus including the image processing means (61) for inspecting the state of the light emitting devices (10A to 10D) included in the lighting means (5),
10D) A light emitting device failure detecting means (94) for detecting from a voltage change in the energizing circuit (9) is provided. Here, the voltage change is determined by a differential amplifier (9) in a current control circuit that feedback-controls the current of the light-emitting devices (10A to 10D).
The change in the output voltage in 2) or the change in the voltage at the connection points (P1 to P4) of the light-emitting devices (10A to 10D) connected in series can be obtained.

In the present invention, when the light emitting device is disconnected or short-circuited, a voltage change occurs in the energizing circuit. Therefore,
By detecting this voltage change, a defect such as a disconnection can be immediately known, and a response such as an inspection stop can be taken promptly.

[0007] The reference numerals in parentheses indicate the correspondence with specific means described in the embodiments described later.

[0008]

(First Embodiment) FIG. 1 shows the overall configuration of a soldering inspection device as an example of a circuit component inspection device. In the figure, a lead 11 of a circuit component 1 is inserted into a through hole 21 of a printed circuit board 2, and is connected and fixed to an electrode (not shown) on the printed circuit board 2 by a soldering portion 3. The printed board 2 is a moving table 4
Of the many circuit components 1 mounted on the printed circuit board 2 and soldered on the printed circuit board 2, an inspection target is transferred and positioned by the moving table 4 directly below the lighting device 5. The moving table 4 includes an X-axis stage 41 and a Y-axis
The printed board 2 can be positioned on a two-dimensional XY plane by being constituted by the axis stage 42. The X-axis stage 41 and the Y-axis stage 42 are servo-controlled by the output of the positioning circuit 72.

The illumination device 5 includes a plurality of annular illumination rings 51.
The illumination rings 51 to 54 are arranged concentrically at intervals in the vertical direction, and are directed upward. As the diameter becomes smaller. Each lighting ring 51-54
Is divided into four sections in the circumferential direction, and a large number (eg, 12
) Light emitting diodes. Lighting ring 5
1 to 54 are respectively connected to an illumination control circuit 71 which will be described in detail later.
The light emitting diode group can be energized to emit light for each of the sections.

The circuit component 1 to be inspected is the lead 1
1 (that is, through hole 21) is positioned on the central axis of lighting device 5, and illumination light L emitted from lighting rings 51 to 54 enters soldering portion 3 of lead 11. Above the illumination device 5, an imaging device 8 such as a CCD camera is provided on the center axis thereof, and the imaging device 8 obtains an image of the soldering section 3. The image obtained by the imaging device 8 is sent to the image processing unit 61 in response to a command from the information processing unit 62 of the data processing device 6, and the image processing unit 61 tracks, for example, the outer periphery of a high-luminance continuous area in the image. Then, the quality of the soldering is inspected from the length of the tracking locus. Data processing device 6
Is composed of a personal computer etc.
U, various memories including a video RAM, an I / O interface, and the like, and a monitor, a printer, and the like are connected. Image processing unit 61 and information processing unit 6
The information processing unit 62 controls the operations of the illumination control circuit 71 and the positioning circuit 72 described above, and the inspection result of each soldering unit 3 in the image processing unit 61 is displayed on a monitor. Display or print out.

FIG. 2 shows an energizing circuit 9 in an illumination control circuit 71 for energizing a group of light emitting diodes constituting one section of each of the illumination rings 51 to 54 to emit light.
The lighting control circuit 71 is provided with such an energizing circuit as the number of sections of the illumination rings 51 to 54 (28 sections in the present embodiment). Although the number of light emitting diodes in each section is actually 12 as described above, FIG. 2 shows only 4 light emitting diodes.

In FIG. 2, light emitting diodes 10A-1A
0D are connected in series with each other to
It is located between. The transistor 91 constitutes a current control circuit together with a differential amplifier 92 connected to the base thereof. The light emitting diode 10D is connected to the collector of the transistor 91, and a current detecting resistor 93 is provided between the emitter and the ground. It is connected. A detection voltage Vr proportional to the current I flowing through the light emitting diodes 10A to 10D is generated in the current detection resistor 93, and the detection voltage Vr is fed back to the "-" terminal of the differential amplifier 92. A predetermined current command value Cv for properly maintaining the illuminance on the printed circuit board 2 (FIG. 1) is input to the “+” terminal of the differential amplifier 92. Further, a voltage comparator 94 is provided. The output voltage Vo of the differential amplifier 92 is input to the voltage comparator 94 and compared with a predetermined reference voltage Vb.

In such a configuration, the current detection resistor 9
The conduction of the transistor 91 is controlled such that the detected voltage Vr of the third circuit 3 always matches the current command value Cv. As a result, a desired current I is supplied to the light emitting diodes 10A to 10D. When a disconnection occurs in any of the light emitting diodes 10A to 10D, the collector current of the transistor 91 becomes zero, and the detection voltage Vr decreases. Therefore, the differential amplifier 9
The output voltage Vo of No. 2 rises to restore the detection voltage Vr, and eventually reaches a saturation voltage. Therefore, the reference voltage Vb
Is set to an appropriate value lower than the saturation voltage, an abnormal signal Sa is output from the voltage comparator 94 when the output voltage Vo exceeds the reference voltage Vb. The abnormal signal Sa is sent to the information processing section 62 (FIG. 1), and the information processing section 62 forcibly ends the inspection and issues an alarm.

(Second Embodiment) FIG. 3 shows an illumination control circuit 7.
1 shows another example of the energizing circuit 9 in FIG. In the present embodiment, the first
Instead of the voltage comparator 94 of the embodiment, the light emitting diode 1
Voltages at connection points P1 to P3 between 0A to 10D and at connection point P4 between light emitting diode 10D and transistor 91 are high input impedance voltage detectors 95A to 95A, respectively.
95D, and voltage comparators 96A to 96D are provided at the subsequent stage of the voltage detectors 95A to 95D, respectively. From each of the voltage detectors 95A to 95D, each connection point P1
To P4 are respectively equal to the voltage comparator 96A.
To 96D. Each voltage comparator 96A-96
An upper limit reference voltage and a lower limit reference voltage are set for D, respectively. These upper and lower reference voltages are the voltages of the connection points P1 to P4 when a predetermined current I flows through the light emitting diodes 10A to 10D. Are set slightly above or below the range of possible values. Other configurations are the same as those of the first embodiment.

In such a configuration, for example, if a short circuit occurs in the light emitting diode 10B, the voltage drop at this portion is eliminated, and the voltage at each of the connection points P2 to P4 closer to the transistor 91 is increased. Each voltage comparator 9
6B to 96D, the voltage exceeds the upper limit reference value. As a result, the abnormal signals Sa2 to Sa2 are output from the voltage comparators 96B to 96D.
Sa4 is output to information processing section 62 (FIG. 1). on the other hand,
When a disconnection occurs in the light emitting diode 10B, the power is not supplied at the connection point P2, the voltage drops, and the voltage comparator 96B outputs the abnormal signal Sa2 to the information processing unit 62.

[0016]

As described above, according to the circuit component inspection apparatus of the present invention, it is possible to promptly respond to the stop of the inspection or the like by quickly detecting a defect such as disconnection of the light emitting device of the lighting device. Becomes

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a soldering inspection device according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram of an energizing circuit.

FIG. 3 is a circuit diagram of an energizing circuit according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Circuit components, 5 ... Lighting device, 6 ... Data processing device, 6
DESCRIPTION OF SYMBOLS 1 ... Image processing part, 8 ... Imaging device, 9 ... Electrification circuit, 92 ...
Differential amplifier, 94 ... voltage comparator, 10A, 10B, 10
C, 10D: light emitting diode, P1, P2, P3, P4
... connection points.

Continued on the front page F term (reference) 2F065 AA49 AA53 AA54 CC01 CC26 DD08 FF04 GG07 GG14 GG17 JJ03 JJ26 NN02 PP12 QQ25 QQ31 SS06 SS09 UU01 2G051 AA61 AA65 AB14 BA01 BA20 CA03 CA04 DA07 EA14 EB01 EB10

Claims (1)

[Claims] An illumination device for illuminating a circuit component, an imaging device for obtaining an image of the illuminated circuit component, and an image processing device for processing the obtained image to inspect the state of the circuit component. The circuit component inspection device according to claim 1, further comprising a light emitting device failure detecting unit configured to detect a failure of the light emitting device included in the lighting unit based on a voltage change in a current supply circuit of the light emitting unit.