KR100684454B1 - System and method for automated optical inspection - Google Patents

Abstract

The present invention relates to an inspection system and method for automatically inspecting the appearance (upper and lower surface) of an inspection object (flexible printed circuit board unit) using an optical method. The automatic optical inspection system of the flexible printed circuit board unit of the present invention has a photographing member that can scan and inspect two or more lights while changing two or more lights with one camera according to the characteristics of each inspection item of the flexible printed circuit board unit. The photographing member includes a camera, an illumination unit for selectively irradiating two types of illumination with the flexible printed circuit board unit, and the camera and the illumination member so that the camera can continuously photograph the surface of the flexible printed circuit board unit in line units. It is provided with a mobile unit for moving back and forth together.

Printed Circuit Boards, Cameras

Description

SYSTEM AND METHOD FOR AUTOMATED OPTICAL INSPECTION}

1 is a view for explaining the configuration of an automatic optical inspection system according to an embodiment of the present invention;

2 is a view for explaining the configuration of the primary photographing member;

3 is a view showing another example of the primary photographing member;

4A to 4C are diagrams illustrating the inversion process of the flexible printed circuit board unit by the inversion unit;

5 shows another example of a rotary table;

6 is a flowchart of an inspection method by the automatic optical inspection system of the present invention;

 7A and 7B are views for explaining a primary photographing member having condensing light and coaxial falloff light;

8A and 8B are views for explaining an example in which the condensing light and the coaxial fall light are moved in a slide manner.

Explanation of symbols on the main parts of the drawings

110: loader

120: moving member

130: primary shooting member

140: inversion unit

150: secondary recording member

160: Unloader

The present invention relates to an automatic optical inspection system, and more particularly, to an inspection system and method for automatically inspecting the appearance (upper and lower surface) of an inspection object (flexible printed circuit board unit) using an optical method.

 Various printed circuit boards are rapidly changing from rigid rigid printed circuit boards to flexible printed circuit boards so that the line width of circuit board becomes thinner and applicable to various types of products due to slim and thinning of various electronic products. have. Therefore, as the line width becomes thinner, the inspection by the human eye becomes more and more difficult, and the problem of the productivity decrease due to the human eye is raised, and the introduction of the automatic optical inspection system becomes necessary to overcome this problem.

The present invention is to solve the above problems, the object is

 The present invention provides a new type of automatic optical inspection system and method for selectively irradiating and scanning different lights according to the characteristics of inspection items of inspection objects. Another object of the present invention is to provide a new type of automatic optical inspection system and method capable of inspecting both the upper and lower surfaces of an inspection object (flexible printed circuit board unit).

The automatic optical inspection system of the flexible printed circuit board unit of the present invention for achieving the above object is to scan and inspect while selectively irradiating two or more lights with one camera according to the characteristics of each inspection item of the flexible printed circuit board unit There are features that can be.

The automatic optical inspection system of the flexible printed circuit board unit of the present invention includes a photographing member for photographing the surface of the flexible printed circuit board unit. The automatic optical inspection system of the flexible printed circuit board unit of the present invention also includes a loader for supplying a flexible printed circuit board unit, a moving member having loading portions on which the flexible printed circuit board unit is placed by the loader, and And an unloader for unloading the inspected flexible printed circuit board unit from the moving member.

In one embodiment, the photographing member is a camera, an illumination unit for selectively irradiating two or more different lights to the flexible printed circuit board unit, and the camera is continuous line-by-line on the surface of the flexible printed circuit board unit It is provided with a mobile unit for moving back and forth together with the camera and the lighting member to be photographed.

In one embodiment, the illumination unit includes a reflection light for irradiating the reflected light to the upper surface of the flexible printed circuit board unit, and a transmission light for irradiating the transmitted light to the bottom surface of the flexible printed circuit board unit. The lighting unit may include condensed light and coaxial fall light.

In one embodiment, the moving member is a rotation having a rotating table in which the loading unit is disposed at an equal angle, and a motor for rotating the rotating table so that the rotating table rotates at the equal angle and stops the operation. With a unit.

In one embodiment, the loader and the unloader each have a transfer arm having suction plates by suctioning the flexible printed circuit board unit under vacuum.

The automatic optical inspection system of the flexible printed circuit board unit of the present invention may further include an inverting unit for absorbing and inverting the flexible printed circuit board unit placed in the loading unit.

In one embodiment, the inverting unit is a holder for holding the flexible printed circuit board unit, the suction plate for vacuum suction for lifting or lowering the flexible printed circuit board unit from the loading unit, the flexible printed circuit board unit lifted from the loading unit, the holder It is provided with a rotation cylinder for rotating the rotating shaft 180 degrees connected to.

The automatic optical inspection method of the flexible printed circuit board unit of the present invention for achieving the above object is the step of providing the flexible printed circuit board unit, the first vision inspection step of inspecting the upper surface of the flexible printed circuit board unit and And unloading the inspected flexible printed circuit board unit.

In an embodiment, the first vision inspection step may include: moving the line scan camera before and after the line scan camera so that the top surface of the flexible printed circuit board unit can be continuously photographed in line units; Selectively irradiating two or more different lights with the flexible printed circuit board unit while moving with the line scan camera; And receiving at least two images obtained from the line scan camera to determine a defective state.

The automatic optical inspection method of the flexible printed circuit board unit of the present invention includes the steps of inverting the flexible printed circuit board unit after the first vision inspection; And a secondary vision inspection step of inspecting a reverse side of the inverted flexible printed circuit board unit.

For example, embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. This embodiment is provided to more completely explain the present invention to those skilled in the art. Accordingly, the shape of the elements in the drawings and the like are exaggerated to emphasize a clearer description.

Exemplary embodiments of the present invention will be described in detail with reference to FIGS. 1 to 8B. In addition, in the drawings, the same reference numerals are denoted together for components that perform the same function.

1 is a view for explaining the configuration of the automatic optical inspection system according to an embodiment of the present invention, Figure 2 is a view for explaining the configuration of the primary photographing member.

1 and 2, the automatic optical inspection system 100 of the present invention is a system for automatically inspecting a test object object (hereinafter, a flexible printed circuit board unit) using a line scan camera and two or more lights.

The automatic optical inspection system 100 of the present invention includes a loader (110), a moving member (120), a primary photographing member (130), an inversion unit (140), a secondary photographing member (150), and an unloader. ; 160).

The loader 110 is a unit for supplying the flexible printed circuit board units 12 one by one to the loading unit of the moving member 120, and has an arm 112 having an adsorption plate 114 for vacuum sucking the flexible printed circuit board unit 12. ). Similarly, the unloader 160 is a unit for unloading the inspected flexible printed circuit board unit 12 from the loading unit to be included in the sorting board 180. The adsorption plate for vacuum adsorption of the flexible printed circuit board unit 12 is performed. An arm 162 having 164.

The moving member 120 includes a rotating table 122 and a rotating unit 126 in which eight loading parts 124 are disposed at equal angles (45 degrees), and the rotating table 122 extends radially from the center. It has two wings (limb) (122a), the loading portion 124 is disposed on each of the wings (122a). The loading unit 124 is sequentially moved along the eight positions 1-8. For example, the rotary table 122 may be manufactured in various shapes such as the circular table 122 ′ as shown in FIG. 5. The rotating unit 126 includes a motor 126a and a rotating shaft 126b. The motor 126a rotates the rotating table 122 at an equal angle of 45 degrees, and repeats an operation of stopping for a predetermined time. To be controlled. Here, operations (loading, inspection, reversal, and unloading) on the flexible printed circuit board unit 12 are performed during the time that the rotary table is stopped.

Briefly, referring to the movement path of the flexible printed circuit board unit 12, the flexible printed circuit board unit includes a loading position 1, a primary inspection position 2 at which an upper surface inspection of the flexible printed circuit board unit is performed, and a spare position ( 3), the unloading position (7) through the reverse position (4), the spare position (5) where the flexible printed circuit board unit is inverted, and the secondary inspection position (6) where the backside inspection of the flexible printed circuit board unit is performed. Is moved to). In addition, the flexible printed circuit board unit moved to the unloading position 7 is unloaded by the unloader 160 to be contained in the sorting board 180 according to good or bad quality. Reference numeral 8 is a spare position. For example, the spare position may be further provided with a photographing member according to the inspection conditions of the inspection object and the user's requirements later.

As shown in FIG. 2, the primary photographing member 130 inspects an upper surface of the flexible printed circuit board unit moved to the primary inspection position 2. The primary photographing member 130 includes a line scan camera 132, an illumination unit 134, and a moving unit 131, which are disposed in the primary inspection position 2.

The illumination unit 134 includes a reflection light 134a for irradiating the reflected light to the upper surface of the flexible printed circuit board unit and a transmission light 134b for irradiating the transmitted light to the bottom of the flexible printed circuit board unit. The line scan camera 132 and the lighting unit 134 are moved together by the moving unit 131 in the front-rear direction (the longitudinal direction of the flexible printed circuit board unit, the direction indicated by the arrow in the figure). Here, the mobile unit 131 may be a cylinder type using hydraulic pressure or various methods using a motor, a ball screw and a transfer nut.

In the primary photographing member 130, the line scan camera 132 obtains the reflected image by using the reflected light when moving forward, and the line scan camera 134 obtains the transmitted image by using the transmitted light when moving backward. The order in which the reflected light and the transmitted light are irradiated may be changed.

 As described above, the primary photographing member 130 obtains a reflection image and a transmission image by using two different types of illumination (transmission and reflection) when the line scan camera 132 is moved back and forth while being scanned for scanning. Because two reflection images can be obtained by using two different reflection lights or different reflections, there is a special effect that can be scanned and inspected by changing the reflected light and transmitted light according to the characteristics of each inspection item of the flexible printed circuit board unit. have.

7A and 7B illustrate a primary photographing member capable of obtaining two images using condensing light and coaxial falloff light.

7A and 7B, an illumination unit 134 having a condensing light 134c and a coaxial falloff light 134d is disposed between the line scan camera 132 and the flexible printed circuit board unit. When the line scan camera 132 moves forward by the moving unit, the coaxial falling light 134d is irradiated, and when the line scan camera 132 moves backward by the moving unit, the condensing light 134c is ancestored. As such, in the present invention, since one line scan camera 132 may sequentially obtain the condensed image and the coaxial fall-off image by moving back and forth, not only can the inspection time be shortened, but the space utilization of the equipment is also increased. Can be.

In particular, the illumination unit 134 having the coaxial falloff light 134d and the condensed light 134c is disposed in the vertical direction as shown in FIG. 7A, or the coaxial falloff light 134d and the condensed light as shown in FIGS. 8A and 8B. 134c may be disposed side by side. In the case of FIG. 8A, the lighting unit is slid so that the coaxial falloff light 134d is positioned under the camera when the line scan camera 132 moves forward, and when the line scan camera moves backward, as shown in FIG. The lighting unit is slid by a driver (not shown) such that 134c is positioned under the camera.

 For example, defect types such as bending of inner leads of the flexible printed circuit board unit, misalignment of solder resistor regions, tearing of pinholes, and conveyance reference holes, etc., can improve inspection quality by irradiating transmission light rather than reflection light. . On the contrary, defect types such as surface inspection (discoloration, scratch, foreign matter, etc.), solder resist surface inspection, and conveyance reference hole surface inspection of the inner lead / pattern plating region of the flexible printed circuit board unit are performed by reflecting illumination rather than through illumination. It can improve inspection quality.

 Below are the types of defects that can be most clearly distinguished by transmission and reflection lighting.

Transmitted light: Inner lead deflection test, solder resist area misalignment, pinhole

-Reflective light: Inspect the surface of inner lead and pattern plating area-Discoloration, SCRATCH, Foreign material on the surface of foreign material / solder resistor, Pinhole, etc.

As described above, the primary photographing member 130 alternately uses the reflection light and the transmission light to accurately determine various types of defects and thus has a special effect of increasing inspection quality.

 As in the present embodiment, one line scan camera, reflection light, and transmission light may be formed as one module, but as shown in FIGS. 3A and 3B, reflection light and transmission light may be installed and used in one line scan camera, respectively. You can think of a situation where you can, and in this case, you can use the spare position that is left.

On the other hand, the flexible printed circuit board unit in which the circuit is printed on both sides of the flexible printed circuit board unit must perform the double-sided inspection. For this reason, according to the present invention, the inspection reliability can be improved by installing the inverting unit and performing the bottom inspection of the inspection object (especially, a flexible printed circuit board unit in which circuits are printed on both sides) by installing an inverting unit. It became.

 4A to 4C, the inversion unit 140 includes an arm 142 having a suction plate 142a for lifting the flexible printed circuit board unit 12 from the loading unit 124, and a flexible printed circuit board unit. It comprises a holder 144 for holding the rotary cylinder 146 (or rotating motor) for rotating the rotating shaft 146a connected to the holder 180 degrees. The flexible printed circuit board unit 12 is inverted by the inversion unit 140 having these configurations.

 4A to 4C illustrate a process of inverting the flexible printed circuit board unit step by step. First, when the flexible printed circuit board unit 12 is adsorbed by the suction plate 142a and lifted from the loading unit 124, the holder 144 holds the flexible printed circuit board unit 12 in the lateral direction. . At this time, the suction plate 142a is separated from the flexible printed circuit board unit 12. In this state, the flexible printed circuit board unit 12 is rotated (inverted) by 180 degrees by the operation of the rotation cylinder 146. When the adsorption plate 142a again adsorbs the flexible printed circuit board unit, the holder 144 is detached from the flexible printed circuit board unit and the flexible printed circuit board unit is placed on the loading unit 124 by the lowering of the arm 142. .

Thus, the flexible printed circuit board unit 12 inverted by the inversion unit in the inversion position 4 is moved to the secondary inspection position 5. Then, the bottom surface inspection of the flexible printed circuit board unit is performed by the secondary photographing member 150. The secondary photographing member 150 includes a camera 152, an illumination unit 154, and a moving unit 151, and since the secondary photographing member 150 has the same function as the aforementioned primary photographing member, detailed description thereof will be omitted.

For example, the camera 152 of the secondary photographing member 150 may be changed to an area scan camera or a color camera, and the transmission light may be omitted when the camera is changed. In addition, the secondary photographing member 150 performs a final inspection function of finally capturing a portion (area) of the flexible printed circuit board unit that has been inspected by the primary photographing member 130 and determined as defective again to determine whether there is a defect. Have These are optional and can be added or omitted depending on the user's needs.

Images (reflected images, transmitted images) captured by the cameras of the first photographing member 130 and the second photographing member 140 are provided to the image processor 190. The image processor 190 is provided as a typical computer system (aka, microcomputer) to control and process various operations according to the automatic optical inspection. The image processor 190 receives images from the cameras and inspects various inspection items. The image processing unit 190 determines the quantity and the total of the flexible printed circuit board unit by integrating the inspection and the results of the inspection items with the images provided from the respective cameras.

In this way, the flexible printed circuit board unit, which is determined by the image processing unit 190 to be positive or not, is moved to the unloading position 7, and the flexible printed circuit board unit is unloaded by the unloader 160 to inspect the result of the inspection. And defective items) are contained in the classification board 180 according to the same.

On the other hand, the present invention can be variously modified and take various forms in the automatic optical inspection system consisting of the above configuration. It is to be understood, however, that the present invention is not limited to the specific forms referred to in the above description, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. It should be understood to do.

Next, the operation relationship of the present invention for inspecting the flexible printed circuit board unit will be described.

1, 2 and 6, the flexible printed circuit board unit 12 is supplied to the loading unit 124 of the rotary table 122 by the loader 110 (S110). As the rotary table 122 is rotated by 45 degrees, the flexible printed circuit board unit 12 is moved to the primary inspection position 2, where the upper surface inspection is performed by the primary photographing member 130 (s120). .

In the primary photographing member 130, the line scan camera 132 obtains the reflected image using the reflected light when the forward movement is performed, and the transmitted image is obtained by using the transmitted light when the line scan camera 132 moves backward to return. The obtained image is provided to the image processor 190.

The flexible printed circuit board unit 12 having the upper surface inspected at the primary inspection position 2 is moved to the reverse position 4 via the spare position 3. The flexible printed circuit board unit 12 moved to the inversion position 4 is inverted by the inversion unit 140 (S130). The inverted flexible printed circuit board unit is moved to the secondary inspection position 5, and the rear side inspection of the flexible printed circuit board unit is performed by the secondary photographing member 150 (S140). The flexible printed circuit board unit having the rear inspection at the secondary inspection position (5) is moved to the unloading position (7) via the spare position (6), and unloaded by the unloader 160 to inspect the inspection result (goods and According to the defective article) will be put in the classification board 180 according to (s150).

In the above, the configuration and operation of the automatic optical inspection system according to the present invention is shown in accordance with the above description and drawings, but this is only an example, and various changes and modifications can be made without departing from the technical spirit of the present invention. Of course.

As described above, the automatic optical inspection system of the present invention can obtain a plurality of reflection images and transmission images sequentially with one camera, thereby providing an optimal inspection for inspecting inspection objects containing various complex defects. It has a special effect to increase space utilization.

 The automatic optical inspection system of the present invention has a special effect of increasing the inspection speed and reliability by inspecting the bottom of the inspection object (flexible printed circuit board unit) that has completed the upper surface inspection by installing an inverting unit. Has

Claims (11)

delete In the automatic optical inspection system of a flexible printed circuit board unit: A loader for supplying the flexible printed circuit board unit; A moving member having loading portions on which the flexible printed circuit board unit is placed by the loader; A primary photographing member inspecting an upper surface of the flexible printed circuit board unit placed on the loading unit;  An unloader for unloading the inspected flexible printed circuit board unit from the moving member; The primary photographing member Line scan camera; A lighting unit for selectively irradiating two different lights to the flexible printed circuit board unit; And And a mobile unit which moves the line scan camera and the illumination unit back and forth together so that the line scan camera can continuously photograph the upper surface of the flexible printed circuit board unit in line units. The illumination unit irradiates any one of the two lights when the line scan camera is moved forward by the mobile unit, and irradiates the other one of the two lights when the line scan camera is moved backward by the mobile unit. Automatic optical inspection system, characterized in that. The method of claim 2, The illumination unit is an automatic optical inspection system, characterized in that it comprises a condensed light and coaxial falling illumination. The method of claim 2, The illumination unit includes a reflection light for irradiating the reflected light to the upper surface of the flexible printed circuit board unit and a transmission light for irradiating the transmitted light to the rear of the flexible printed circuit board unit, automatic Optical inspection system. The method of claim 2, The automatic optical inspection system And a reversing unit for absorbing and inverting the flexible printed circuit board unit placed in the loading unit, wherein the flexible printed circuit board unit is inverted for photographing one side and the reverse side of the flexible printed circuit board unit. Automatic optical inspection system of the unit. The method of claim 5, The reversal unit An adsorption plate for vacuum adsorption to lift or lower the flexible printed circuit board unit from the loading unit; And a holder for holding the flexible printed circuit board unit lifted from the loading unit and a rotating cylinder for rotating the rotating shaft connected to the holder by 180 degrees. The method according to claim 2 or 5, The mobile unit A rotating table in which the loading parts are arranged at equal angles; And a rotating unit having a motor for rotating the rotating table so that the rotating table rotates at the equal angle and stops.  The method according to claim 2 or 5, And the loader and the unloader each include a transfer arm having suction plates by suctioning the flexible printed circuit board unit with a vacuum. In the automatic optical inspection method of a flexible printed circuit board unit: Providing the flexible printed circuit board unit; A primary vision inspection step of inspecting an upper surface of the flexible printed circuit board unit; Comprising the step of unloading the flexible printed circuit board unit after the inspection; The first vision inspection step The line scan camera is moved forward and backward so that the line scan camera can continuously photograph the upper surface of the flexible printed circuit board unit in line units, and two different illuminations are selectively changed according to the movement of the line scan camera before and after. Investigating; And receiving two images obtained from the line scan camera to determine a defective state. The method of claim 9, The first vision inspection step is irradiated with any one of the two illuminations when the line scan camera moves forward, And the other one of the two illuminations is irradiated when the line scan camera is moved backward by the moving unit. The method of claim 9, In the automatic optical inspection method, Inverting the flexible printed circuit board unit after the first vision inspection; And And a second vision inspection step of inspecting the reverse side of the inverted flexible printed circuit board unit, wherein the flexible printed circuit board unit is inverted for backside photographing after the topside photographing.

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