JPH08195600A - Polarity inspection for electronic component - Google Patents

Abstract

PURPOSE: To surely and accurately detect a polarity indication of an electronic component such as an electrolytic capacitor mounted on a printed board. CONSTITUTION: A normal polarity indication M is discriminated by tilting a reflecting type optical sensors 3a... and radiating the laser-light E to the side face Hs of an electronic component H from an oblique direction, and at the same time, carrying out detection of at least two or more positions on the side face Hs, e.g. a position Zm where the normal polarity indication M exists and a position Zn which is on the opposite side of and at 180 deg. from this position Zm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarity inspection of an electronic component mounted on a printed circuit board when the polarity of the electronic component is detected by a detection head section having a reflection type optical sensor arranged facing the printed circuit board. Regarding the method.

[0002]

2. Description of the Related Art Conventionally, as a method of detecting the polarity display of an electronic component such as an electrolytic capacitor, a method of reading the polarity display by a reflection type optical sensor is known (Japanese Patent Laid-Open No. Sho 60).
-34100 gazette etc.).

A device for inspecting the appearance of a printed circuit board emits light in a direction perpendicular to the printed circuit board and emits light from a reflective optical sensor provided in a detection head section facing the printed circuit board. 2. Description of the Related Art There is known an appearance inspection device that detects the appearance state of a printed circuit board by receiving reflected light from the board.

[0004]

By the way, since the above-described conventional visual inspection apparatus detects the outer surface of the electronic component by scanning with light, the polarity may be reversed depending on the type of the electronic component. Nevertheless, since there is a display of characters, figures, patterns, etc. other than the polarity display, there is a risk of misidentifying these as the polarity display and detecting them.
When the polarity indication of the electronic component mounted on the printed circuit board is present on the side surface of the electronic component, there is a problem that detection is practically difficult.

The present invention has solved the problems existing in such conventional techniques, and is capable of reliably and accurately detecting the polarity indication of an electronic component such as an electrolytic capacitor mounted on a printed circuit board. The purpose is to provide a method.

[0006]

According to a method of inspecting a polarity of an electronic component according to the present invention, a polarity display M of an electronic component H such as an electrolytic capacitor Hc mounted on a printed circuit board P is arranged facing the printed circuit board P. The reflective optical sensor 3a ..., more specifically, the detection having the reflective optical sensor 3a ... Equipped with the light emitting section 3at ... which emits the laser light E and the light receiving section 3ar ... which receives the reflected light Er of the laser light E. Head 2a
When detecting with ..., Especially, the reflection type optical sensor 3a
By inclining the ..., The laser light E is emitted from the oblique direction to the side surface Hs of the electronic component H, and at least two or more different positions on the side surface Hs, for example, the position Zm where the regular polarity display M exists. The normal polarity display M is discriminated by detecting the position Zn on the opposite side of 180 ° to the position Zm.

[0007]

According to the polarity inspection method for an electronic component according to the present invention, first, since the reflection type optical sensors 3a ... Are arranged so as to face the electronic component H, the polarity display M existing on the side surface Hs of the electronic component H is indicated. The reflective optical sensor 3a
It is done by tilting. Thereby, the reflective optical sensor 3
Laser light E emitted from the light emitting section 3at ...
Hits the side surface Hs of the electronic component H from an oblique direction,
The polarity display M on the side surface Hs of the electronic component H can be detected.

Further, at least two or more different positions on the side surface Hs, specifically, a position Zm where the normal polarity display M exists and a position Zn opposite to this position Zm by 180 ° are detected. To do this, for example, the electronic component H
Depending on the type, there is a display other than the polarity display, a figure or a pattern, etc., and even if the display other than the polarity is detected for the electronic component H mounted with the opposite polarity, no misidentification occurs, The regular polarity display M can be identified.

[0009]

Next, preferred embodiments according to the present invention will be described in detail with reference to the drawings.

First, a configuration of an appearance inspection apparatus 1 capable of implementing the polarity inspection method for electronic parts according to this embodiment will be described with reference to FIG.
~ It demonstrates with reference to FIG.

The appearance inspection apparatus 1 is roughly divided into a substrate transfer mechanism section 10, detection head sections 2a and 2b, a head movement mechanism section 6, a control section 7, and an inspection function section 8.

As shown in FIG. 4, the substrate transfer mechanism section 10 includes a conveyor belt 11 spanning between a front pulley 21f and a rear pulley 21r, and a conveyor belt 12 spanning between a front pulley 22f and a rear pulley 22r. The transport belts 11 and 12 are arranged separately in the Y direction. In this case, the conveyor belts 11 and 12 are endless timing belts and pulleys 21.
Reference characters f, 22f, 21r, 22r are gears. Further, as shown in FIG. 3, the front pulleys 21f and 22f are rotated by a drive unit 25 having a servo motor 23 and a transmission mechanism 24, and the respective conveyor belts 11 and 12 are transported in the front-rear direction, that is, the X direction. .

On the other hand, 13 is a substrate loading table supported by the conveyor belts 11 and 12. Board loading table 13
As shown in FIGS. 5 and 6, the conveyor belts 11 and 12
L-shaped supported frames 26, 2 to be placed on
7, a pair of left and right substrate loading frames 28 and 29 fixed to the inner end surfaces of the supported frames 26 and 27, and a front coupling frame 30a for coupling the respective substrate loading frames 28 and 29,
30c and the rear connecting frames 30b and 30d form a rectangular frame shape. Further, the substrate loading table 13 is guided in the X direction by the guide channel 14 provided with a U-shaped guide channel 14 which is open upward as viewed from the front. The guide channel 14 is formed of a highly rigid material to provide vibration damping. As a result, the supported frames 26 and 27 are positionally regulated in the left-right direction (Y direction) by the guide channel 14, and the substrate loading frames 28 and 29 are positionally regulated downward by the guide channel 14. In addition, each of the pulleys 21f, 22f,
21r and 22r are also supported by the guide channel 14.
The substrate loading table 13 may be fixed to or detachable from the conveyor belts 11 and 12.

Accordingly, as shown in FIG. 5, the left and right ends of the printed circuit board P are supported by the supported frames 26, 27 and the substrate loading frames 28, 29. In this case, the substrate loading table 13 includes a pair of spaced conveyor belts 11,
Since it is supported by 12, the surface P of the printed circuit board P is
Obstacles at the time of inspection above f and below the back surface Pr are eliminated, and the overall weight is reduced. Further, since the board loading table 13 is guided in the X direction by the guide channel 14, the supporting rigidity for the printed board P is enhanced, and in combination with the weight reduction of the mechanism side that supports the printed board P, the printed board P is also supported. Responsiveness (following property) during transfer of is improved, and accurate position control becomes possible.

On the other hand, the head moving mechanism portion 6 is provided with the endless belt 5 which moves in a direction orthogonal to the X direction. The endless belt 5 is provided with a pair of endless belt portions (timing belts) 5a and 5b that are separated in the X direction. As shown in FIGS. 3 and 4, one endless belt portion 5a is arranged at four positions in the vertical and horizontal directions. Guide pulleys (gears) 31a, 32a, 33
a and 34a, and the other endless belt portion 5b is also bridged over the guide pulleys (gears) 31b, 32b, 33b, ...
Is configured so that the printed circuit board P can pass therethrough. As a result, the endless belt portions 5a and 5b have a belt upper surface portion 5a which is parallel to the surfaces Pf and Pr of the printed circuit board P.
Since u and 5bu and the belt lower surface portions 5ad and 5bd are provided, the support plate 38 is installed between the belt upper surface portions 5au and 5bu, and the belt lower surface portions 5ad and 5b are provided.
A support plate 39 is installed between d. As shown in FIG. 3, the front and rear sets of guide pulleys 34a are rotated by a drive unit 37 having a servomotor 35 and a transmission mechanism 36, and the endless belt 5 is moved in the Y direction (left and right direction).

Further, the detection head portions 2a and 2b are attached to the support plates 38 and 39, respectively. The detection head unit 2a (same for 2b) includes a reflective optical sensor 3a as shown in FIG. The optical sensor 3a includes a light emitting unit 3at that emits a laser beam E to the printed circuit board P and a light receiving unit 3ar that receives the reflected light Er of the laser beam E reflected from the printed circuit board P. Such an optical sensor 3
By providing a, the distance to the printed circuit board P or the amount of light can be measured, and the degree of unevenness or the degree of lightness and darkness of the front surface Pf and back surface Pr of the printed circuit board P can be detected.
Further, the optical sensor 3 a is supported by the sensor support mechanism 16. In this case, the optical sensor 3a is rotatably supported with the horizontal axis K as a fulcrum, rotatably supported with a vertical axis (not shown) as a fulcrum, and further supported so as to be vertically movable. Thereby, the optical sensor 3a can change the angle and / or the height. Note that 3b (see FIG. 2) indicates a reflective optical sensor provided in the detection head unit 2b.

On the other hand, the control unit 7 is provided with a motor control unit 51, which drives and controls the servomotors 23 and 35. Further, the motor control unit 51 is connected to the printed circuit board design CAD system 15. Printed circuit board design CAD system 1
5 is the CA of the print pattern on the printed circuit board P.
Since the D data is stored, the motor control unit 51, based on the CAD data, controls the servomotors 23 and 35.
Control pattern for controlling, that is, each detection head unit 2a,
Set the movement pattern for 2b. As a result, each of the detection head units 2a and 2b moves on the printed circuit board P by X
It is possible to move relatively in the Y-direction and the Y-direction and pass a predetermined inspection position D1 ... (See FIG. 2) on the front surface Pf and the back surface Pr of the printed circuit board P. On the other hand, the inspection function unit 8
Determines whether or not the detection result obtained from the reflective optical sensor 3a at each inspection position D1 based on the movement pattern is good, and at the time of detecting the polarity display, the electronic component H
Detection is performed on two or more different positions on the side surface Hs of the (electrolytic capacitor Hc), specifically, a position Zm where the normal polarity display M exists and a position Zn opposite to the position Zm by 180 °. Regular polarity display M when performing
Equipped with a function to determine.

Next, the operation of the visual inspection apparatus 1 including the polarity inspection method according to the present invention will be described with reference to FIGS.

First, the printed board P is loaded on the board loading table 13. Then, the servo motor 23 is operated by the motor control unit 51, and the printed circuit board P is transferred in the X direction (front-back direction) at the set predetermined speed. In this case, as shown in FIGS. 1 to 3, the printed circuit board P has the electronic components H (electrolytic capacitor Hc) ... Mounted on its front surface Pf, and the soldering portions J ... on its back surface Pr.

On the other hand, the servo motor 35 is also operated by the motor control section 51, and the detection head sections 2a and 2b are moved in the Y direction (left and right direction) according to the movement pattern set in the motor control section 51. As a result, the respective detection head units 2a and 2b move relative to the printed circuit board P in the X direction and the Y direction as shown in FIG. 2, and according to the movement pattern, the front surface Pf and the back surface of the printed circuit board P. Predetermined inspection positions D1, D2 in Pr
Pass through D3, D4, D5, D6 .... In this case, the inspection positions D1 ... Are sequentially set in the X direction from both the front surface Pf and the back surface Pr of the printed circuit board P. That is, in FIG. 2, the component mounting state of the front surface Pf at the inspection position D1 is first detected by the detection head unit 2a, and then the soldering state of the back surface Pr at the detection position D2 is detected by the detection head unit 2b. And each inspection position D
When passing through 1 ..., the degree of unevenness or the degree of brightness of the printed circuit board P at each inspection position D1 ... Is detected by each reflective optical sensor 3a, 3b. The detection result is provided to the inspection function unit 8 and inspected for defects such as mounting defects in which no components are loaded and soldering defects in which soldering is not performed. The reflective optical sensor 3a
Is moved up and down by the sensor support mechanism 16 according to the height of the component H mounted on the printed circuit board P, for example.

On the other hand, as shown in FIG.
When the vertical electrolytic capacitor Hc is mounted on the substrate, the polarity of the electrolytic capacitor Hc is inspected as follows. The vertical electrolytic capacitor Hc has a polarity display M on the side surface Hs.

First, the position Z where the regular polarity display M exists
Perform the detection at m. In this case, since the optical sensor 3a is disposed above the electrolytic capacitor Hc, the sensor support mechanism 16 tilts the reflective optical sensor 3a and moves it up and down as necessary. The reflective optical sensor 3a at this position is indicated by 3ax. As a result, the laser light E emitted from the light emitting portion 3at in the reflective optical sensor 3a strikes the side surface Hs of the electrolytic capacitor Hc obliquely from above, and the reflected light Er is received by the light receiving portion 3ar. At this time, if the optical sensor 3a is rotated about the vertical axis as a fulcrum, the laser light E scans the polarity display M in the horizontal direction at a predetermined speed, so that the detection signal shown in FIG. 6A is obtained. In FIG. 6A, V1 indicates a detection voltage when the side surface of the electrolytic capacitor Hc other than the polarity display M is detected, V2 indicates a detection voltage when the polarity display M is detected, and a circle indicates a detection point. Show. Further, since the detection result is given to the inspection function unit 8, the inspection function unit 8 determines the presence or absence of the polarity display M based on the light amount of the reflected light Er and the detection range. In order to minimize the influence on the inclination of the electrolytic capacitor Hc,
It is desirable to emit the laser light E to the lower part of the electrolytic capacitor Hc.

Next, detection is performed at the position Zn on the opposite side of 180 ° to the position Zm. In this case, the motor control unit 51 controls the X-direction transfer mechanism unit 10 and the Y-direction movement mechanism unit 6 to move the optical sensor 3a, and further controls the sensor support mechanism 16 to move the optical sensor 3a. , 180 ° about the vertical axis as a fulcrum and tilted, and thereafter, detection is performed in the same manner as the detection for the position Zm. The optical sensor 3a at this position is indicated by 3ay. Since the optical sensor 3a includes the light emitting unit 3at and the light receiving unit 3ar which are separated from each other, when the optical sensor 3a is moved to the position of 3ay by rotating the optical sensor 3a by 180 ° about the vertical axis as a fulcrum, the optical sensor 3a has the structure shown in FIG. As shown, the laser light E can be emitted at a more nearly right angle with respect to the side surface of the electrolytic capacitor Hc.
FIG. 6B shows the detection signal obtained at this time.

Therefore, in the inspection function unit 8, the position Zm where the normal polarity display M exists in the electrolytic capacitor Hc.
Then, since the inspection results of both the positions Zn on the opposite side to the position Zm by 180 ° are obtained, the regular polarity display M can be reliably detected. In particular, depending on the type of the electrolytic capacitor Hc (electronic component H), there are other indications other than the polarity indication, figures or patterns, etc., and although the polarities are mounted opposite to each other, the electrolytic capacitor Hc has a polarity other than the polarity. Even when a display or the like is detected, the normal polarity display M can be reliably and accurately discriminated without causing misjudgment by selecting or comparing and analyzing a detection result closer to the determination value for the polarity display M.

On the other hand, FIG. 8 shows a modified embodiment of the control unit 7. In the modified embodiment, a movement pattern is set based on teaching data for a predetermined inspection position D1 ... In FIG. 8, reference numeral 17 is a teaching machine including a signal processing unit and a storage unit, and 18 is an input device connected to the teaching machine 17. As a result, the actual inspection position D1 on the printed circuit board P from the input device 18 ...
, The teaching machine 17 stores the teaching data for the inspection position D1, ... At the time of inspection, the detection head units 3a and 3b move in the X direction with respect to the printed circuit board P in accordance with the movement pattern based on the teaching data. And relatively move in the Y direction.

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment,
The detailed configuration, shape, arrangement, quantity and the like can be arbitrarily changed without departing from the scope of the present invention.

[0027]

As described above, in the method of inspecting the polarity of an electronic component according to the present invention, by tilting the reflection type optical sensor, light is emitted obliquely to the side surface of the electronic component for detection. Since the normal polarity display is determined by detecting at least two or more different positions on the side surface of the electronic component, the polarity display of the electronic component such as the electrolytic capacitor mounted on the printed circuit board can be reliably performed. It has a remarkable effect that it can be accurately detected.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an inspection head unit in an appearance inspection apparatus capable of implementing a polarity inspection method according to the present invention,

FIG. 2 is a plan view of a printed circuit board showing a movement locus of an inspection head unit in the appearance inspection apparatus;

FIG. 3 is a block diagram of the appearance inspection device,

FIG. 4 is a perspective view showing a schematic configuration of a main part of the appearance inspection apparatus,

FIG. 5 is a partial cross-sectional front view of a substrate transfer mechanism section in the appearance inspection apparatus,

FIG. 6 is a partial plan view of a substrate transfer mechanism section in the appearance inspection apparatus,

FIG. 7 is a detection signal diagram by an inspection head unit in the appearance inspection apparatus,

FIG. 8 is a block configuration diagram showing a modified embodiment of a control unit in the appearance inspection apparatus,

[Explanation of symbols]

1 Appearance inspection device 2a ... Detection head part 3a ... Reflective optical sensor 3at Light emitting part 3ar Light receiving part P Printed circuit board Hc Electrolytic capacitor M Polarity display M H Electronic component E Laser light Er Reflected light Hs Side surface Zm There is a normal polarity display. Position Zn 180 with respect to the position where the regular polarity display exists
° Opposite position

Claims (4)

[Claims] 1. A method of inspecting the polarity of an electronic component mounted on a printed circuit board by a detection head unit having a reflective optical sensor disposed facing the printed circuit board, wherein the reflective optical sensor is used. By inclining, the light is emitted obliquely to the side surface of the electronic component for detection, and at the same time, at least two or more different positions on the side surface of the electronic component are detected for normal polarity display. A method for inspecting the polarity of an electronic component, which comprises: 2. The method for inspecting the polarity of an electronic component according to claim 1, wherein the electronic component is an electrolytic capacitor. 3. The method for inspecting the polarity of an electronic component according to claim 1, wherein the reflective optical sensor includes a light emitting portion that emits laser light and a light receiving portion that receives reflected light of the laser light. 4. The position on the side surface of the electronic component to be detected is a position where the normal polarity display is present and a position opposite to this position by 180 °, or 3. The method for inspecting the polarity of an electronic component as described in 3.