JP2002198700A - Mark detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mark detecting device capable of accurately detecting the presence or absence of a mark on a circuit board. SOLUTION: This mark detecting device (30) using an optical sensor is provided with a projecting means (31) for irradiating the surface of a circuit board (12) with a laser beam (L) and a light receiving means (32) for receiving reflected lights so that a mark(bad mark B) attached to the surface of the circuit board for indicating the validity/invalidity of the circuit board. Also, this mark detecting device is provided with an irradiation angle changing means (40) for changing the irradiation angle of lights by the projecting means according to the surface state of the circuit board. Therefore, it is possible to easily change the irradiation angle of the laser beam according to the surface state of the circuit board, and to improve the detecting precision of the bad mark.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mark detecting device capable of accurately detecting a mark attached to a circuit board for indicating the quality of the circuit board.

[0002]

2. Description of the Related Art Normally, when manufacturing a circuit board using an electronic component mounting apparatus for mounting an electronic component on a circuit board, before mounting the electronic component by the electronic component mounting apparatus is started, For example, an inspection is performed to determine whether the wiring pattern is correctly formed on the circuit board, whether the solder is correctly applied, and the like. If it is determined that the circuit board is defective, a mark (bad mark) indicating that the circuit board is defective is attached at a predetermined position on the circuit board. As the bad mark, for example, a seal or an oil paint is used. Then, the defective and non-defective circuit boards are conveyed together into the electronic component mounting apparatus without being separated.

In an electronic component mounting apparatus, a bad mark is detected on each circuit board by using an optical sensor or the like before starting the operation of mounting the electronic component on the circuit board. Then, the component mounting is not performed on the circuit board on which the bad mark is detected, and the component mounting is performed only on the circuit board on which the bad mark is not detected, that is, the circuit board determined to be non-defective. You.

As a method of detecting a bad mark using the above-described optical sensor, for example, the optical sensor has a so-called bundle fiber, and a circuit board is irradiated from a light-projecting optical fiber arranged at the center. The structure is such that the reflected light of the laser light is detected by a plurality of light receiving fibers (bundle fibers) arranged so as to surround the light projecting fiber. And, for example, if a black seal is affixed to the circuit board as a bad mark, since the reflectance of light is different between the circuit board surface and the bad mark, there is a case where laser light is directly irradiated on the circuit board surface. The amount of reflected light reaching the light-receiving optical fiber varies between the case where the light beam is radiated to the bad mark. By detecting the intensity of the light quantity, it is determined whether or not a bad mark is attached to the circuit board, that is, whether or not the circuit board is defective. In order to accurately perform a bad mark detection operation on a circuit board using the above-described optical sensor, it is necessary to irradiate a laser beam as vertically as possible to a portion where the bad mark is attached on the circuit board surface.

Here, since the circuit board is generally made of glass epoxy or ceramics, it is hard and has high strength. However, the circuit board is slightly bent or tilted due to the structure of the circuit board transfer device. May occur on the circuit board. And, since this bending or inclination occurs in a substantially constant direction regardless of the type of the circuit board, in the actual bad mark detection work, in order to irradiate the laser beam substantially perpendicularly to the bad mark attaching portion, usually, The laser light is emitted in a state where the laser light is slightly inclined with respect to the direction perpendicular to the circuit board transfer surface.

[0006]

By the way, in recent years, a flexible circuit board (FPC: Flexi
ble Printed Circuit) has been used. A flexible circuit board is made by attaching electronic components to a printed wiring board in which a circuit pattern is formed on the surface of a flexible polymer resin insulator, and has the property of being thin and easily bent. I have. In the manufacturing process of the flexible circuit board as well, the work of detecting the bad mark on the flexible circuit board is performed in the same manner as in the case of the ordinary circuit board made of ceramics or the like as described above. Due to the characteristics of the flexible circuit board, the bending and inclination of the portion where the bad mark is attached differ for each flexible circuit board. Therefore, if the laser light is irradiated while the laser light is slightly tilted with respect to the circuit board transfer surface, as in the case of a normal circuit board, it is difficult to detect the reflected light depending on the degree of inclination of the circuit board. There is a problem that mark detection cannot be performed.

An object of the present invention is to provide a mark detection device capable of accurately detecting the presence or absence of a mark on a circuit board in consideration of the above problems.

[0008]

According to a first aspect of the present invention, there is provided a mark detection device, comprising: a mark detecting device for determining whether a circuit board is good; Light emitting means (31) for irradiating light (laser light L) to a portion (bad mark attachment position X) on the surface of the circuit board where a mark is to be detected in order to detect a bad mark B)
And a light detecting means (32) for receiving light reflected from the circuit board, the mark detecting device using an optical sensor,
An illumination angle changing unit (40) capable of changing an irradiation angle of light by the light projecting unit according to a surface state of the circuit board is provided.

According to the mark detecting device of the first aspect,
Since the irradiation angle of the laser beam can be easily changed according to the surface condition of the circuit board, the accuracy of the quality judgment of the circuit board is improved. In addition, by improving the accuracy of the quality judgment of the circuit board, it is possible to prevent, for example, erroneous mounting of an electronic component or the like on the defective circuit board, so that the circuit board manufacturing cost can be reduced.

According to a second aspect of the present invention, there is provided the mark detecting apparatus according to the first aspect, wherein the light projecting axis of the light projecting means and the light receiving axis of the light receiving means are parallel. It is characterized by being arranged.

According to the mark detecting device of the second aspect,
The same effect as that of claim 1 can be obtained, and the space around the optical sensor is widened by using an optical sensor in which the light projecting axis of the light projecting means and the light receiving axis of the light receiving means are arranged in parallel. Further, the weight of the optical sensor can be reduced. Further, by arranging the light projecting axis of the light projecting means and the light receiving axis of the light receiving means in parallel, the reflection angle of light that can be received by the light receiving means is limited. Is provided, the mark can be detected regardless of the type of the circuit board.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a mark detecting device according to the present embodiment will be described with reference to the drawings. As shown in FIG. 1, the mark detection device 30 is provided in a general electronic component mounting device 10 for mounting electronic components on the circuit board 12. The electronic component mounting device 10 includes an electronic component supply unit 11 (for example, a tape feeder) that supplies an electronic component,
A suction nozzle 13 for vacuum-holding an electronic component and mounting it at a predetermined position on a circuit board 12, a circuit board transfer device 14 for transferring the circuit board 12, supporting the suction nozzle 13, and moving the suction nozzle 13 up and down. And an XY moving mechanism (not shown) for moving the head in the horizontal direction. The mark detection device 30 according to the present embodiment is attached to a support plate 15a provided on the head unit 15 side, and is movable with the head unit 15 to an arbitrary position on the circuit board 12. In addition, a driving unit 16 such as a motor and a timing belt used for transporting the circuit board 12 and moving the head unit 15 (FIG. 2)
), And a position detection unit 17 for detecting the position of the head unit 15.

The control means 20 (see FIG. 2) controls the driving of the driving means 16 so that the circuit board 12
Is transported into the electronic component mounting apparatus 10, the head unit 15 is moved to a predetermined position on the electronic component supply unit 11, and the electronic component is vacuum-sucked by the suction nozzle 13. Then, the head unit 15 is moved to a predetermined position on the circuit board 12, the vacuum suction state of the suction nozzle 13 is released at the predetermined position on the circuit board 12, and the electronic component is mounted on the circuit board 12. A component mounting operation is performed. Since the control method of the drive means 16 by the control means 20 is a known technique, its description is omitted, and the mark detection device 30 according to the present embodiment will be mainly described below.

As shown in FIG.
Is to irradiate a laser beam L to a position on the surface of the circuit board 12 where a bad mark B (see FIG. 4) is attached (hereinafter, referred to as a “bad mark attaching position X”) and detect the reflected light. This is a device provided for determining whether or not the bad mark B is attached to the circuit board 12, that is, for determining whether the circuit board 12 is good.

In this embodiment, as shown in FIG. 4, a black seal is used as the bad mark B.
The bad mark B is to be attached to the bad mark attaching position X of the circuit board 12 determined to be defective.
The circuit board 12 shown in FIG. 4 is a so-called collective circuit board 12, in which two circuit boards 12a before division are collectively arranged on a single plate. Then, in this state, the electronic components are mounted by the electronic component mounting apparatus 10, and in a subsequent process, the division work into two circuit boards is performed. In the case of such an integrated circuit board, a bad mark sticking position X is usually set for each of the two circuit boards 12a.

The mark detecting device 30 includes a light projecting means 31, a light receiving means 32, and an irradiation angle changing means 40 (see FIGS. 3, 5 to 9). It is assumed that the light sensor 31, the light receiver 32, the controller 20 and the like constitute an optical sensor. As shown in FIG. 9, the light projecting means 31 includes a light projecting optical fiber 31a, a light emitting element (not shown) such as a light emitting diode, and the like.
Is provided for irradiating a laser beam L to the laser beam. The laser light L generated from the light emitting element is transmitted to the light projecting optical fiber 31a.
And passes through the lens 34 to form a bright spot on the surface of the circuit board 12.

The light receiving means 32 includes a light receiving optical fiber 32a.
And a light amount detection device. Optical fiber for light reception 32
A is plurally arranged along the outer peripheral direction of the light projecting optical fiber 31a. Therefore, as shown in FIG. 9, the light projecting axis 31b of the light projecting means 31 and the light receiving axis 32b of the light receiving means 32 are arranged in parallel. The periphery of the plurality of light receiving optical fibers 32a is covered with a protective member 35 such as rubber. The laser light L reflected on the surface of the bad mark sticking position X passes through the lens 34 and the light receiving optical fiber 32a, and reaches the light amount detecting device. Then, the light amount detection device detects the light amount of the reflected light,
This data is output to the control means 20. In the following description, the light emitting optical fiber 31a provided integrally is provided.
A portion composed of the distal end of the light receiving optical fiber 32a, the lens 34, and the cylindrical body 36 accommodating them, is referred to as a light emitting / receiving section 37.

The irradiation angle changing means 40 is provided for adjusting the optical axis (the light projecting axis 31b and the light receiving axis 32b) of the light projecting / receiving section 37, and is provided on the head section 15 side as shown in FIG. It is joined to the support plate 15a and supports the light emitting and receiving unit 37 so as to be movable in the front-rear direction. The irradiation angle changing means 40 includes a fixed bracket 50 and a movable bracket 60 as shown in FIG. The fixed bracket 50 is a member that is joined to the head unit 15 via the support plate 15a and that supports the movable bracket 60 so that it can rotate and move along the front-rear direction. And a second bracket 52. The first bracket 51 is a plate body formed such that the side surface thereof is substantially L-shaped when viewed from the side, and includes a contact portion 51a and a joint portion 51b. The contact portion 51a is provided with an elongated hole 51c extending vertically. The contact portion 51a is joined to the support plate 15a at a portion of the elongated hole 51c by a well-known fastening means such as a bolt and a nut while being in contact with the support plate 15a. The elongated hole 51c allows the irradiation angle changing means 40 to be used.
The vertical mounting position can be adjusted. The joining portion 51b is a member provided to extend forward from an upper edge portion of the contact portion 51a, and is joined to a second bracket 52 described later on a left side portion thereof.

The second bracket 52 is a substantially L-shaped plate in a side view, and includes a joint 52a and a support 52b. The joining portion 52a is joined at its upper edge to the joining portion 51b of the first bracket 51, and is joined at its lower surface to the support portion 52b. Support 52
b has a slit 52c for supporting a movable bracket 60 to be described later so as to be able to rotate and move along the front-rear direction. The slit 52c is provided so as to rise rearward. Therefore, as will be described in detail later, the movable bracket 60 is slidably supported along the slit 52c via the angle adjusting screw 63.

The movable bracket 60 is a member provided for adjusting the optical axis of the optical sensor. The movable bracket 60 is joined to the light emitting and receiving unit 37 and is supported by the fixed bracket 50 so as to be movable and pivotable in the front-rear direction. ing. The movable bracket 60 has a side surface substantially L when viewed from the front.
It is a plate formed to have a character shape, and includes a support portion 61 and a joint portion 62. A screw receiving hole 61a is provided in an upper portion of the support portion 61. Then, the support portion 61
The slit 52c and the screw receiving hole 61a are in contact with the support portion 52b of the second bracket 52.
Is fixed by inserting an angle adjusting screw 63 therethrough. The joining portion 62 is a member provided to extend from the lower edge portion of the support portion 61 in the horizontal direction on the opposite side to the second bracket 52, and has a substantially semicircular cutout portion 62 a Is provided. Then, the cylindrical body 36 of the light emitting and receiving unit 37 is fitted into the cutout portion 62a, and is joined to the light emitting and receiving unit 37 by using a well-known joining means. The joining means is, for example, two nuts that are screwed into screws formed on the outer periphery of the light emitting and receiving unit 37, and is joined by sandwiching the joint 62 from above and below with these nuts. Therefore, by moving the movable bracket 60 along the slit 52c, it is possible to position the light emitting and receiving unit 37 in the front-rear direction and the up-down direction. The irradiation angle of the laser beam L by the section 37 can be adjusted.

The control means 20 (see FIG. 2) controls the driving of each of the driving means 16 provided in the electronic component mounting apparatus 10, and further, based on data relating to the amount of reflected light output from the light amount detecting apparatus. The circuit board 12 is provided to detect the presence or absence of the bad mark B on the circuit board 12 and determine the quality of the circuit board 12. The control means 20 includes a CPU 21 and a ROM 2
2, a control unit main body 26 composed of a RAM 23, an input interface 24, and an output interface 25
And an input unit 27 and a display unit 28.

The control means 20 usually includes, in addition to a program for controlling each driving means, circuit board data such as the type of electronic component mounted on each circuit board 12, the mounting position of the electronic component, and the like. Data relating to the material of the circuit board and the type of the circuit board (such as a collective circuit board and a flexible circuit board) are input in advance. Furthermore, the bad mark sticking position X differs depending on the shape of the circuit board,
In the case of a collective circuit board, data relating to the bad mark sticking position X for each type of the circuit board 12 is also input, corresponding to the fact that the bad mark B is stuck to each circuit board 12a before division. Have been. Control means 2
In addition to these data, data relating to the amount of reflected light (reference light amount) used to determine the quality of each circuit board 12 is input to 0.

The mark detecting device 30 according to the present embodiment
The method of determining whether the circuit board 12 is good or bad by using
2 is a flexible circuit board, the optical axis of the light emitting and receiving unit 37 is adjusted so that the irradiation direction of the laser beam L is perpendicular to the circuit board transport surface.
Is made of a hard material such as glass epoxy or ceramic, the irradiation direction of the laser light L is perpendicular to the circuit board transport surface so that the irradiation direction of the laser light L is substantially perpendicular to the inclination of the circuit board 12 generated in a certain direction. Adjust to a slightly inclined state.

When the circuit board 12 is transported from the circuit board transport device 14, the CPU 21 of the control means
From the circuit board data stored in the RAM 23, the type of the circuit board 12, for example, whether it is a collective circuit board or a flexible circuit board, etc., is recognized. Bad mark sticking position X
Read the data related to Then, at a predetermined bad mark sticking position X, a laser beam L is irradiated, and the light amount of the obtained reflected light is compared with a reference light amount.
Is determined. When it is determined that the circuit board 12 is a non-defective product, each driving unit 16 is driven to mount components on the circuit board 12. If it is determined that the circuit board 12 is defective, each driving unit 16 is controlled so that components are mounted on the circuit board 12.

The mark detection device 30 shown in the present embodiment
According to the method, the irradiation angle of the laser light L can be easily changed according to the surface condition of the circuit board 12, so that the accuracy of the quality judgment of the circuit board 12 is improved. In addition, accurate pass / fail judgment can be performed on the flexible circuit board 12.
Further, since the accuracy of the quality judgment of the circuit board 12 is improved, it is possible to prevent the electronic components from being erroneously mounted on the defective circuit board 12, so that the manufacturing cost of the circuit board 12 can be reduced. Further, a light projecting axis 31b of the light projecting means 31 is provided.
By using an optical sensor in which the light receiving shaft 32b of the light receiving means 32 is arranged in parallel with the light receiving means 32, the space around the head unit 15 is widened. Further, the weight of the optical sensor can be reduced, and the weight of the entire head 15 can be reduced, so that the positioning accuracy of the head 15 can be improved.

In the present embodiment, the mark detection device 30 is provided in the head portion 15 of the electronic component mounting device. However, the mark detection device 30 may be provided in a portion other than the head portion 15. Further, the bad mark B may be detected for the circuit board 12 on which the mounting of the electronic component is completed. Alternatively, the fixed bracket 50 and the movable bracket 60 may be integrally formed.

The shapes of the fixed bracket 50 and the movable bracket 60 are not limited to those shown in the present embodiment, but may be any shapes that can easily adjust the irradiation angle of the laser beam L. Further, the light projecting means 31 and the light receiving means 3
2 may be divided and arranged. Further, the switching of the irradiation angle of the light emitting / receiving unit 37 by the irradiation angle changing unit 40 may be performed not by manual operation as described in the present embodiment but by a driving unit such as a motor or an actuator. In this case, the control means 20
However, based on the circuit board data, the driving of the irradiation angle changing means 40 may be controlled so as to set the irradiation angle according to the type of each circuit board.

[0028]

According to the mark detecting device of the present invention, the irradiation angle of the laser beam can be easily changed according to the surface condition of the circuit board, so that the accuracy of the quality judgment of the circuit board is improved. In addition, by improving the accuracy of the quality judgment of the circuit board, it is possible to prevent, for example, erroneous mounting of an electronic component or the like on the defective circuit board, so that the circuit board manufacturing cost can be reduced.

According to the mark detecting device of the second aspect,
The same effect as that of claim 1 can be obtained, and the space around the optical sensor is widened by using an optical sensor in which the light projecting axis of the light projecting means and the light receiving axis of the light receiving means are arranged in parallel. Further, the weight of the optical sensor can be reduced. Further, by arranging the light projecting axis of the light projecting means and the light receiving axis of the light receiving means in parallel, the reflection angle of light that can be received by the light receiving means is limited. Is provided, the mark can be detected regardless of the type of the circuit board.

[Brief description of the drawings]

FIG. 1 is a front view showing an electronic component mounting apparatus according to an embodiment.

FIG. 2 is a block diagram illustrating a structure of an electronic component mounting device.

FIG. 3 is a front view (A) and a side view (B) showing a mark detection device.

FIG. 4 is a plan view showing a position where a bad mark is attached on a circuit board.

FIG. 5 is a perspective view showing an irradiation angle changing unit.

FIG. 6 is a side view (A), a plan view (B), and a front view (C) showing a movable bracket.

FIG. 7 is a front view (A), a side view (B), and a plan view (C) showing a fixing bracket.

FIG. 8 is a front view showing an irradiation angle changing unit.

FIG. 9 is a vertical sectional view showing a light emitting and receiving unit.

[Explanation of symbols]

 B mark (bad mark) L light (laser light) X bad mark sticking position 12 circuit board 30 mark detecting device 31 light emitting means 31b light emitting axis 32 light receiving means 32b light receiving axis 40 irradiation angle changing means

Claims (2)

[Claims] 1. A light projecting means for irradiating a mark on a surface of a circuit board with light to detect a mark on the surface of the circuit board to indicate the quality of the circuit board; And a light receiving means for receiving the reflected light of the mark detection device, comprising: an irradiation angle changing means capable of changing an irradiation angle of light by the light projecting means in accordance with a surface state of the circuit board. A mark detection device characterized by the above-mentioned. 2. The mark detecting apparatus according to claim 1, wherein a light projecting axis of said light projecting means and a light receiving axis of said light receiving means are arranged in parallel.