KR20150018122A - Automatic optical inspector for the flexible printed circuit board - Google Patents

Abstract

The present invention relates to an automatic optical inspector for a flexible printed circuit board which can distinct defect of a plated part and an insulation layer by simultaneously examining not only a surface plated part of a material, but also a circuit pattern formed inside the insulation layer by sequentially arranging a VRS camera and a vision camera, and arranging lighting device under the vision camera in two lines. Provided in the present invention for achieving the purpose is an automatic optical inspector for a flexible printed circuit board which comprises a support including a movable caster; a stone plate; a work table performing a flattening adjustment; a VRS camera for obtaining video data of the surface of a material; a first moving robot adjusting Y-axial movement of the VRS camera; a first elevation adjustment robot; a pair of vision cameras; a second moving robot adjusting the X-axial movement of the vision cameras; a camera stage; and a lighting device.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an automatic optical inspection apparatus for a flexible printed circuit board,

The present invention simultaneously inspects whether or not a plating part pattern of a substrate (FPCB) capable of being refracted through an automatic optical inspection (AOI: Auto Optical Inspection) or a refractable substrate (RFPCB) The present invention relates to an automatic optical inspection apparatus for a flexible printed circuit board capable of simultaneously inspecting not only a plating pattern formed on a printed circuit board but also a pattern defect of an insulating layer below a plating layer, To an automatic optical inspection apparatus.

As the growth of the electronic parts industry in the IT field becomes prominent, the structure of the electronic parts becomes very complicated, and accordingly, there is a need for an inspection technology having excellent detection capability. Particularly, printed circuit boards (PCBs), which are important elements of electronic, information and communication devices, are becoming more and more miniaturized due to increasing density and miniaturization of electronic components. Accordingly, the importance of PCB pattern inspection technology is increasing have. At present, we are applying a pattern automatic optical inspection equipment (AOI: Auto Optical Inspection) which can inspect patterns formed on a PCB substrate to production equipment.

The above-mentioned automatic optical inspection equipment is capable of detecting defects that can occur in an inner layer image and an acid etching process, that is, open and short of an inner layer circuit which is an important defect occurring in a PCB production site, It is a device that inspects defects by image processing using a computer such as nicks, protrusions in which circuits are etched, slits, pinholes, copper foil residue, and foreign substances.

BACKGROUND ART As semiconductor devices become smaller and smaller, they are made of a tape substrate such as TAB (Tape Automatic Bonding) or a printed circuit board such as a COF (Chip On Film). In a film or tape type printed circuit board, fine patterns are formed by methods such as exposure and development. The automatic optical tester acquires image data of the printed circuit board using transmitted light or reflected light, and obtains an image with optimal focus at this time.

As a method for optically inspecting a printed circuit board in the form of a film or tape using a camera or the like in an automatic optical tester, there are a method using reflected light (see FIG. 1) and a method using transmitted light (see FIG. 2). The former AOI apparatus 100 implements a method of acquiring a reflected light image from the camera 112 to a printed circuit board 116, that is, an object to be inspected, as a reflected image by the upper illuminator 114 do. The latter AOI apparatus 120 implements a transmission light image acquisition method for inspecting a transmission image from the camera 122 by the lower illumination 124 of the object to be inspected 126, as shown in FIG.

AOI equipment (100 or 120) introduced into a conventional film or tape type printed circuit board manufacturer is inspected using only one of a reflected light image acquisition method or a transmitted light image acquisition method. However, there is a problem in that, in order to judge whether or not a defect is caused by only one method, an over-detection phenomenon which discriminates a good product as defective due to foreign matter and dust is increased. In other words, since foreign materials and dust do not affect the performance of the product itself, they should be distinguished as good products. However, in the automatic inspection method using only one of the reflection illumination or the transmission illumination, such minute foreign matter, dust, and the like are detected as defective items on the pattern inspection. Therefore, such detection has caused not only a rise in the cost of the product and a decrease in the productivity but also a major cause of doubt on the reliability of the automatic optical inspection apparatus for the customer. Particularly, in recent years, such a printed circuit board, for example, a film such as TAB or COF, or a tape-shaped substrate has a lead width becoming narrower and narrower.

In order to prevent an inspection error of the AOI apparatus, a 'method for preventing over detection of optical inspection and a system for performing the same' in Korean Patent Laid-Open Publication No. 2004-0011676 has been proposed.

In order to prevent undesired detection by foreign substances or the like generated in a method of inspecting using transmitted light or reflected light according to the related art, the system uses two types of light sources, that is, a printed circuit board in the form of a film or a tape Inspect. As a result, the detection and the detection are significantly reduced compared to the inspection according to the related art. However, when two types of light sources are used to pick up a printed circuit board in the form of a film or tape, the incident angle, the focal distance, and / It is necessary that the imaging focus position is not coincident with each other due to the refractive index or the like, and a more accurate focus is required.

As described above, the conventional automatic optical tester of the prior art inspects optically film and tape-shaped substrate patterns using various cameras. When inspecting the same object and / or the same area with the same camera, The optimum focal position in the transmitted light image using the transmission illumination and the optimum focal position in the reflected light image using the reflective illumination may be different depending on the type of the reflected light and the condition of the object to be inspected. This results in a result that the focal position of the reflected light image and that of the transmitted light image are inverted from the same camera, so that either the reflected light image or the transmitted light image deviates from the optimum focal position.

Conventionally, in order to overcome the above-mentioned problem, Japanese Patent No. 10-0589978 proposes an automatic focusing system of an automatic optical system using a plurality of light sources. The patent discloses that the light source 133 of each of the reflection light 130 and the transmission light 132 is irradiated on the printed circuit board 134 and the light signal of the light source 133 of the camera 136 The first and second focus information are detected and the first and second focus information are applied to the control unit 138 to control the driving unit 142 by the calculation of the autofocus algorithm 140, Is a technology for automatically checking the appearance of a printed circuit board by autofocusing. By acquiring accurate image data for a film or tape type printed circuit board using two kinds of light sources, it is possible to improve the accuracy and reliability of an automatic optical inspection system will be.

A method of automatically inspecting the appearance of a printed circuit board using various light sources as described above is to be applied to a dense substrate which is impossible to be inspected by the naked eye, that is, a dense wiring formed on a printed wiring board, a hole and a substrate on which components are arranged at a high density On the other hand, there is a technical limitation that it is difficult to confirm whether or not the pattern inside the insulating layer of the substrate is defective.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in order to solve all of the above problems, and it is an object of the present invention to provide a VRS camera and a vision camera in sequence, And an object of the present invention is to provide an automatic optical illumination device of a flexible printed circuit board capable of discriminating whether or not a plating portion and an insulating layer are defective by simultaneously inspecting a circuit pattern.

Also, the present invention can acquire accurate image data through alignment of a camera, can realize an accurate and fast inspection speed, can discriminate microscopic defects that can not be recognized by the naked eye, and can perform automatic optical inspection (AOI) Another object is to provide an automatic optical illumination device of a flexible printed circuit board capable of AVI (Automatic Visual Inspection) inspection.

According to an aspect of the present invention, A stepped seat which is seated on the upper end of the support and on which a linear motor mounting space is formed; A work table which is conveyed to the left and right on the stone tabletting tray and on which a suction pad is mounted to perform a flattening adjustment while fixing a pattern printed material by a vacuum suction force; A linear motor installed at one side of the stone quarry and driving the workbench so as to be linearly moved in the longitudinal direction; A VRS camera installed at an upper portion of the stone quarry and for acquiring image data of a work surface placed on a work table; A first mobile robot installed on one side of the VRS camera and adjusting its Y axis movement; A first lifting and lowering robot connected to the first mobile robot for adjusting the height of the VRS cage; A pair of vision cameras installed on the other end of the stone quartz panel and capturing image data of a metal pattern by picking up a material fixed to a workpiece; A second mobile robot installed on one side of the vision camera and adjusting its X axis movement; A second lift control robot installed on the other side of the vision camera to adjust its height; A camera stage installed at the lower end of the vision camera to adjust an interval therebetween; And an illuminating device installed at a lower end of the vision camera for irradiating the material of the vision camera with high efficiency so as to acquire a pattern image of the interior of the substrate plating part and the insulating layer. do.

As described above, according to the present invention, the following effects are realized.

First, by arranging the illumination devices mounted on the lower side of the stage for moving the vision camera in two rows, the vision camera can simultaneously inspect the plating part pattern on the substrate and the pattern inside the insulating layer.

Second, the work table on which the suction pads are mounted is moved by the driving of the linear motor on the stone tabletting surface, and the position of the workpiece is aligned with the position adjusting robot through the position adjusting robot so that the inspection speed is fast and the defect is accurately read .

Third, it is possible to inspect microscopic defects that can not be recognized by the naked eye, and it is possible to inspect both sides of the material.

1 is a schematic diagram of a general automatic optical inspection apparatus using reflected light,
2 is a schematic diagram of a general automatic optical inspection apparatus using transmitted light,
3 is a schematic configuration diagram of an automatic optical inspection apparatus equipped with a plurality of light sources according to the related art,
4A to 4C are a front view, a plan view, and a side view, respectively, showing a configuration of an automatic optical illumination device of a flexible printed circuit board according to the present invention;
5 is a detailed view showing a configuration of a VRS camera which is a main part of the present invention;
FIG. 6 is a detailed configuration diagram showing a state of arrangement of a vision camera and a lighting device, which are essential parts of the present invention;
7 is a photograph showing inspection items performed in the automatic optical inspection apparatus according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings of FIGS.

The automatic optical inspection apparatus of a flexible printed circuit board according to the present invention is a system for arranging reflection lights for illuminating a vision camera in two rows and performing accurate alignment of a camera to form a coating on a flexible printed circuit board (FPCB) It is possible to inspect not only the sub-pattern but also the defect of the circuit pattern in the insulating layer at a time, and to speed up the inspection speed.

FIGS. 4A to 4C are a front view, a plan view, and a left side view, respectively, showing a configuration of an automatic optical inspection apparatus of a flexible printed circuit board according to the present invention. FIG. 5 is a detailed view showing a configuration of a VRS camera, FIG. 6 is a detailed block diagram showing the arrangement of a vision camera and a lighting device, which are essential parts of the present invention.

As shown in the drawings, the present invention comprises a support base 2 on which a movable caster 2a is mounted; A stone pot (4) which is seated on the upper end of the support base (2) and in which a space portion (4a) for mounting a linear motor is formed at one side and a rail groove (4b) is formed at a central portion; A work table 6 mounted on a rail groove 4b of the stone stone table 4 to be conveyed to the right and left and equipped with a suction pad 6a at its upper end to perform flattening adjustment while fixing a pattern printed material by a vacuum suction force, Wow; A linear motor 10 installed in the space portion 4a of the stone stone table 4 to drive the work table 6 to be linearly moved in the longitudinal direction; A VRS (Verified Reworking System) camera 12 installed at the upper center of the stone block 4 to acquire image data of the position of the material placed on the worktable 6 and to perform a defect check after inspection; A first mobile robot 14 installed on one side of the VRS camera 12 and aligning the VRS camera 12 to move the VRS camera 12 in the Y axis so that the VRS camera 12 can focus on the exact position of the material, ; A first lifting and lowering robot 15 connected to the first mobile robot 14 for adjusting the height between the VRS camera 12 and the workpiece; A pair of vision cameras 16 installed above the other end of the stone block 4 for picking up a material fixed on the work table 6 to acquire image data of a metal pattern and an inner layer pattern of the insulating layer; A second mobile robot (18) installed at one side of the vision camera (16) and adjusting its X axis movement; A second lifting and lowering robot 20 installed on the other side of the vision camera 16 to adjust its height; A vision camera transfer stage 22 installed at a lower end of the vision camera 16 for transferring the vision camera 16 in the anteroposterior direction; And a lighting device (24) arranged in two rows at the lower end of the vision camera transfer stage (22) for enabling the vision camera (16) to irradiate the material with high efficiency to acquire pattern images in the substrate plating part and the insulating layer .

Here, as shown in Fig. 6, the illumination device 24 is arranged with two reflection lights on both sides thereof to acquire the surface of the material picked up by the vision camera 16 and the image of the insulating layer.

The first and second moving robots 14 and 18 are attached to the ends of the fixing screw 25 and the fixing screw 25 connected to the lower ends of the VSR camera 12 and the vision camera 16 respectively, And a stepping motor 26 for providing rotational force.

Reference numeral 28 denotes a control box for controlling the linear motor.

The operation state of the present invention configured as described above will be described as follows.

When a work is placed on the worktable 6, a vacuum attraction force is provided through the suction pad 4a to adjust the flatness while fixing the work. When the workpiece is fixed at the workpiece and the linear motor 10 is driven, the workbench 6 moves along the rail groove 4b of the stone block 4.

When the workbench 6 stops at a predetermined position, the VRS camera 12 is driven by the first mobile robot 14 to move to the Y-axis direction and to the Y- The surface of the material is photographed in a state in which the distance from the material is adjusted. A surface defect of the material exposed in the image photographed by the VRS camera 12 is displayed through a monitor (not shown), and the operator confirms this.

When the surface of the workpiece is confirmed to be defective by the VRS camera 12, the work table 6 is again moved toward the vision camera 16 by driving the linear motor 10 and stopped. Then, the second mobile robot 18 is driven so that the vision camera 16 is positioned above the work table 6. [ At the same time, the second lifting and lowering control robot 20 is driven to adjust the gap between the vision camera 16 and the work. When the positions of the vision camera 16 and the workpiece are aligned as described above, the vision camera transfer stage 22 is driven to adjust the interval of the vision camera 16 to photograph the workpiece in the optimal state. When the vision camera 16 photographs the material, images of the surface layer and the insulating layer of the material are obtained by the illumination device 24 arranged on both sides of the vision camera 16. [ Through the image thus obtained, it is possible to confirm not only the plating part pattern of the material but also the defect of the circuit pattern in the insulating layer.

As shown in FIG. 8, according to the present invention, various inspection items can be inspected at a time.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be clear to those who have knowledge.

2: support 4:
6: Work table 10: Linear motor
12: VRS camera 14: First mobile robot
15: First lift control robot 16: Vision camera
18: second mobile robot 20: second lift control robot
22: Vision camera feed stage 24: Lighting device
25: Fixing screw 26: Stepping motor
28: Control box

Claims (3)

A support table on which the movable casters are mounted;
A stepped seat which is seated on the upper end of the support and on which a linear motor mounting space is formed;
A work table which is conveyed to the left and right on the stone tabletting tray and on which a suction pad is mounted to perform a flattening adjustment while fixing a pattern printed material by a vacuum suction force;
A linear motor installed at one side of the stone quarry and driving the workbench so as to be linearly moved in the longitudinal direction;
A VRS camera installed at an upper portion of the stone quarry and for acquiring image data of a work surface placed on a work table;
A first mobile robot installed on one side of the VRS camera and adjusting its Y axis movement;
A first lifting and lowering robot connected to the first mobile robot for adjusting the height of the VRS cage;
A pair of vision cameras installed on the other end of the stone quartz panel and capturing image data of a metal pattern by picking up a material fixed to a workpiece;
A second mobile robot installed on one side of the vision camera and adjusting its X axis movement;
A second lift control robot installed on the other side of the vision camera to adjust its height;
A vision camera transfer stage installed at the lower end of the vision camera to adjust an interval therebetween; And
And a lighting device installed at the lower end of the vision camera to allow the vision camera to irradiate the material with high efficiency to acquire a pattern image of the interior of the substrate plating part and the insulating layer
And an automatic optical inspection apparatus for a flexible printed circuit board.
The method according to claim 1,
Wherein the lithotripsy is provided with a space for mounting the linear motor and a rail groove for guiding the work table to move.
The method according to claim 1,
Wherein the illumination device is arranged in two rows.

Images