KR100673392B1 - Automatic optical inspection system for printed circuit board of film, tape type and method for processing of the same - Google Patents

Abstract

 The present invention relates to a system for preventing overdetection of a printed circuit board in the form of film and tape using optical and a test method thereof. The automatic optical inspection system of the present invention determines whether the pattern is defective by using the image data obtained by using transmitted light and / or reflected light from the printed circuit board as the first reference value of the brightness illuminometer. Then, the units determined to be defective determine whether the defect is actually a pattern defect or a defect caused by a good quality foreign material using the second brightness illuminometer reference value. Therefore, according to the present invention, by using the subdivided reference values to discriminate the unit over-detected as defective by the non-defective foreign matter, rather than the defective unit, the over-detection is prevented to improve the inspection efficiency in the inspection process.

 Semiconductor manufacturing equipment, automatic optical inspection system (AOI), film, tape type printed circuit board, overdetection, binarization value

Description

 AUTOMATIC OPTICAL INSPECTION SYSTEM FOR PRINTED CIRCUIT BOARD OF FILM, TAPE TYPE AND METHOD FOR PROCESSING OF THE SAME}

1A to 1D are diagrams showing projections, short circuits, or foreign matter determined from image data obtained by using transmitted light of a printed circuit board in the form of a film and a tape;

2A to 2B are diagrams showing protrusions or foreign matters determined from image data obtained by using reflected light of a printed circuit board;

3 is a block diagram showing a configuration of an automatic optical inspection system according to an embodiment of the present invention;

4 is a block diagram showing the configuration of the computer system shown in FIG.

5 is a flowchart showing an operation procedure of an automatic optical inspection system according to an embodiment of the present invention; And

6 to 8 are diagrams showing a state for determining a defect of a pattern by applying a histogram method according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

100: inspection system 102: AOI

110: unwinding unit 120: vision inspection unit

130: poor processing unit 140: winding unit

150: AOI controller 170: computer system

The present invention relates to an automated optical inspection system (AOI system), and more specifically, when inspecting the appearance of a printed circuit board (PCB) in the form of a film and a tape, a good product is detected as a defective product. The present invention relates to a system for preventing overdetection and processing method thereof.

Semiconductor Devices For example, printed circuit boards, which are one of the main materials used in the manufacture of various semiconductor integrated circuits such as LCD driver ICs and memories of liquid crystal display devices, include film and tape. ) And the like.

Such printed circuit boards in the form of films and tapes are, for example, tape automatic bonding (TAB) or chip on film (COF) substrates. In a printed circuit board, fine patterns are formed through a manufacturing process such as exposure and development in the form of a film and a tape substrate, and the quantity and defect determination of the pattern shape are very important factors for the productivity of the printed circuit board.

In addition, in the inspection of the appearance of printed circuit boards in the form of films and tapes automatically by using optics, overdetection, which is a good product in accordance with standards but is determined to be defective by foreign substances such as dust, may affect the reliability of the product and the automatic optical inspection system. It is an important factor that has an absolute impact.

In the industry that manufactures semiconductor integrated circuit film and tape printed circuit board, various problems such as short circuit, short circuit, protrusion, and dent in micro pattern of the product occur, causing big problems. And the situation is a key to quality control.

Inspection by manpower, which is one of the inspection methods for this, is increasingly difficult and impossible to inspect effectively because the printed circuit boards in the form of films and tapes are manufactured in ultra-fine patterns. Accordingly, the demand for the automatic inspection device by the optical image acquisition is exploding and it is becoming an essential facility.

However, a general automatic inspection apparatus acquires an optical image and processes the image by an image processing apparatus, a computer, etc., to determine whether the pattern is good. This automatically determines the poorly manufactured products as defective, and discards them, greatly reducing productivity. This leads directly to deteriorating profitability of manufacturing companies.

1A to 1D are diagrams showing protrusions, short circuits, or foreign matter determined from image data obtained by using transmitted light of a printed circuit board in the form of a film and a tape. 2A to 2B are diagrams illustrating protrusions or foreign matters determined from image data obtained by using reflected light of a printed circuit board in the form of a film and a tape.

1A and 1B, image data 2 of a printed circuit board in the form of a film and a tape obtained using transmitted light in a general automatic optical inspection system (not shown) are respectively projections of actual leads 4. The image data 2 for the case of (8) and the short circuit 10 and the case of the projection 12 and the short circuit 14 due to the foreign matter or dust in FIGS. 1C and 2B and the like differ in the illuminometer, respectively. In the transmission image, the lead 4 of the printed circuit board is displayed in black, and the space 6 is displayed in white.

However, the projections 8 and the short circuit 10 due to the actual manufacturing defects of FIGS. 1A and 1B and the dust and foreign matters of FIG. The projections 12 and the short circuit 14 are identified by the automatic optical inspection system as projections and short circuits protruding from the lid 4 in the same manner, and both are treated as pattern defects.

In addition, referring to FIG. 2A, the image data obtained by using the reflected light is a projection 16 caused by an actual manufacturing defect, which is the same as the quality projection 18 that looks like an actual projection by dust or foreign matter in FIG. 2B. All of them are determined and treated as defective.

As described above, the optical automatic inspection system introduced to a conventional film or tape type printed circuit board manufacturer acquires an image through transmitted light or reflected light, and through this, the pattern area and the spatial area are classified to determine the quantity and defect of the pattern. The judgment was made. In this way, when a good foreign material, dust, etc. exist in a circuit, the image as shown to FIG. 1C, FIG. 1D, and FIG. 2B is obtained, and it causes overdetection. Therefore, the overdetection phenomenon generated during the inspection process of the printed circuit board in the form of film and tape is a factor of lowering productivity and cost.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to provide an inspection system and method for preventing overdetection of discriminating good quality due to foreign matter and dust in the inspection target pattern of a printed circuit board in the form of film and tape. To provide.

Another object of the present invention is to solve the above problems, an inspection system and an inspection system for preventing the over-detection phenomenon generated during the appearance inspection of the printed circuit board in the form of film and tape using the characteristics of the optical brightness meter To provide a method.

Another object of the present invention is to solve the above-mentioned problems, an apparatus and method for improving productivity by preventing over-detection to determine good quality in the automatic optical inspection system of a printed circuit board in the form of film and tape To implement.

According to an aspect of the present invention for achieving the above object, an automatic optical inspection system for inspecting whether a circuit pattern of a plurality of printed circuit boards having a circuit pattern and a space is defective: the respective printing using a light source; An automatic optical inspector for obtaining image data corresponding to circuit boards; A control unit which receives the image data from the automatic optical inspector and determines each of the image data by a brightness illuminometer in units of pixels at a first brightness level identifying the circuit pattern and the space Including; If the circuit pattern of the printed circuit board is determined to be defective by the first brightness level, the controller is further configured to determine that the circuit pattern determined to be defective by using a second brightness level corresponding to a predetermined actual failure pattern is actual. Secondarily, it is determined whether or not it is defective.

In this aspect, the control unit; If the light source is transmitted light, the second brightness level is smaller than the first brightness level, and if the brightness level of the circuit pattern determined as the defect is between the first and second brightness levels, The defect of the pattern is determined to be due to good foreign matter, and the defective circuit board is discriminated as good quality. Wherein the control unit; When the brightness level of the circuit pattern determined as the defect is less than or equal to the second brightness level, the circuit pattern is determined as an actual defect, and the printed circuit board with the defect discriminated is determined as a defect.

In this aspect, the control unit; If the light source is reflected light, the second brightness level is greater than the first brightness level, and if the brightness level of the circuit pattern determined to be defective is between the first and second brightness levels, the circuit The defect of the pattern is judged to be due to a good foreign matter, and the printed circuit board which is determined as the defect is discriminated as good quality. Wherein the control unit; When the brightness level of the circuit pattern determined as the defect is equal to or greater than the second brightness level, it is preferable to determine the circuit pattern as the actual defect and determine the printed circuit board determined as the defect as the defect.

In this aspect, the control unit is provided with a computer system, the computer system mutually transmits the image data and the secondary discrimination information through the automatic optical inspector and a computer network.

In this aspect, the control unit; And a program for extracting brightness levels in pixel units of the image data.

 According to another aspect of the present invention for achieving the above object, an automatic optical inspection system for inspecting whether or not a circuit pattern of a plurality of printed circuit boards is defective: corresponding to each of the printed circuit boards by generating the transmitted light from the light source An automatic optical inspector for acquiring image data; A control unit which receives the image data from the automatic optical inspector and determines whether each of the image data is a good value of the printed circuit board as a first reference value according to a brightness illuminometer in units of pixels; The control unit secondly determines whether the printed circuit board determined as defective is actually defective using the second reference value of the brightness illuminometer smaller than the first reference value for the printed circuit board determined as defective by the first reference value. .

In this aspect, the control unit; If the brightness level of the circuit pattern of the printed circuit board determined as the defect is between the first and the second reference value, it is determined that the defect of the circuit pattern is due to a good quality foreign object, and the quality of the printed circuit board determined as the defect is good. Determine with. Wherein the control unit; When the brightness level of the circuit pattern determined as the defect is less than or equal to the second reference value, it is preferable to determine the circuit pattern as the actual defect and determine the printed circuit board determined as the defect as the actual defect.

 According to another aspect of the present invention for achieving the above object, an automatic optical inspection system for inspecting whether a plurality of printed circuit boards of the circuit pattern is defective, by generating reflected light from the light source to the respective printed circuit boards An automatic optical inspector for acquiring corresponding image data; A control unit which receives the image data from the automatic optical inspector and determines whether each of the image data is a good value of the printed circuit board as a first reference value according to a brightness illuminometer in units of pixels; The control unit secondly determines whether the printed circuit board determined as defective is actually defective using the second reference value of the brightness illuminometer greater than the first reference value for the printed circuit board determined as defective by the first reference value. .

In this aspect, the control unit; If the brightness level of the circuit pattern of the printed circuit board determined as the defect is between the first and the second reference value, it is determined that the defect of the circuit pattern is due to a good quality foreign object, and the quality of the printed circuit board determined as the defect is good. Determine with. Wherein the control unit; When the brightness level of the circuit pattern determined as the defect is equal to or greater than the second reference value, it is preferable to determine the circuit pattern as the actual defect and determine the printed circuit board determined as the defect as the actual defect.

 According to another aspect of the present invention for achieving the above object, an inspection method for preventing over-detection to determine the good quality in the automatic optical inspection system for inspecting the circuit pattern of the printed circuit board in the form of film and tape Silver: imaging the printed circuit board using a light source; Acquiring image data corresponding to the printed circuit board; Determining whether the printed circuit board is positive or negative based on a first reference value for identifying the circuit pattern according to the brightness level of the pixel unit; And determining the actual defective state of the printed circuit board determined by the first reference value as the second reference value of the brightness level corresponding to the actual defective pattern, thereby preventing overdetection.

In this aspect, the step of determining the defective state; When the light source is transmitted light, the second reference value is provided with a brightness level smaller than the first reference value, and when the brightness level of the circuit pattern determined as the failure is between the first and the second reference value, the second reference value is determined as the failure. The printed circuit board is judged to be good products due to good foreign matter. The determining of the defective state may include; If the brightness level of the circuit pattern of the printed circuit board determined as defective by the first reference value is less than the second reference value, the printed circuit board determined as the defective is determined as the actual defect.

In this aspect, the step of determining the defective state; When the light source is reflected light, the second reference value has a brightness level greater than the first reference value, and if the brightness level of the circuit pattern determined as the failure is between the first and the second reference value, the failure is determined as the failure. The printed circuit board is judged to be good products due to good foreign matter. The determining of the defective state may include; If the brightness level of the circuit pattern of the printed circuit board which is determined to be defective by the first reference value is greater than the second reference value, it is preferable to determine the printed circuit board that is determined to be defective as an actual defect.

Therefore, according to the present invention, by over-determining by using the subdivided reference values, the unit over-detected due to the defect by the foreign matter rather than the defective unit as a good product, to prevent over-detection.

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

First, in order to prevent over-detection when inspecting the appearance of a flexible printed circuit board, the flexible printed circuit board of Patent No. 2003-41230 (filed date: June 24, 2003) filed by the present applicant Optical inspection system and method for preventing overdetection. The optical inspection system inspects the appearance of a flexible printed circuit board in the form of a film and a tape using transmitted light and / or reflected light over a second stage. However, this too lacks efficiency to prevent overdetection. Accordingly, the optical inspection system of the present invention is directed to an improved invention of the aforementioned patent for further improving efficiency.

Specifically, the configuration of the automatic optical inspection system according to the present invention is shown in FIG. 3.

Referring to FIG. 3, the automatic optical inspection system 100 includes an automatic optical inspector (AOI) 102 and a computer system 170 capable of data communication with the AOI 102.

The automatic optical inspector (AOI) 102 includes a vision inspector 120 and a defect processor 130 between the winding unit 110 and the winding unit 140, and performs all the operations of these components. AOI control unit 150 to control.

The unwinding unit 110 provides the vision inspection unit 120 with a printed circuit board in which a printed circuit board in the form of a film or a tape is continuously connected in a reel or roll form.

The vision inspection unit 120 photographs the printed circuit boards provided from the unwinding unit 110 and provides them to the AOI control unit 150. For example, image data regarding the fine circuit pattern of the printed circuit board unit is obtained by using a transmission light source or a reflection light source and at least one CCD camera, and the obtained image data is output to the AOI controller 150.

The defect processing unit 130 is punched or marked to display the defective printed circuit board finally determined as defective as a result of the inspection, and is output to the winding unit 140.

The winding unit 140 receives and rewinds the inspected printed circuit boards from the vision inspection unit 120 through the defect processing unit 150.

The AOI controller 150 controls overall operations of the AOI 102, receives image data captured by the vision inspection unit 120, and provides an interface (eg, LAN, RS-232C, etc.) for data communication. It is provided to the computer system 170, and receives the inspection information according to the good or bad judgment from the computer system 170 to drive the operation of the components (110, 120, 130 or 140) of the AOI (102).

The computer system 170 is a main control unit for controlling all operations of the inspection process according to the present invention. As shown in FIG. 4, the computer system 170 includes components of a typical computer system. The computer system 170 includes a control unit 172, a display unit 174, an input unit 176, an interface unit 178, and a storage unit 180. In addition, the computer system 170 is provided independently of the AOI 102, as shown in the figure, but may be provided in a batch type provided integrally with the AOI 102.

The controller 172 is provided with, for example, a central processing unit, a control program, and the like. The controller 172 receives image data captured by the AOI 102, converts the image data into histogram-type data, and displays the image data 182. And monitor the illuminometer brightness level according to the histogram. That is, the controller 172 processes the operation procedure shown in FIG. 5 to improve the yield of the optical inspection.

The display unit 174 displays the image data 182 and displays a histogram type brightness illuminometer in units of pixels.

The input unit 176 outputs an input signal for selecting, inspecting, editing, and confirming the image data 182 in units of pixels.

The interface unit 178 is a device for mutual data communication with the AOI 102. For example, the interface unit 178 receives image data captured from the AOI 102 using a communication protocol such as a LAN or RS-232, and inspects the data. Information according to the result is output to the AOI 102.

The storage unit 180 stores the histogram analysis program 186, the image data 182, and the editing program 184 according to the present invention. The histogram analysis program 186 receives the image data 182 and converts the data in a histogram manner, and outputs a brightness illuminometer of each pixel for determining whether the pattern is valid from the obtained image data. In addition, the histogram analysis program 186 may be configured such that the control unit 172 corresponds to a first reference value corresponding to a threshold value according to the illuminometer brightness level, that is, a first reference value and a light source, that is, transmitted or reflected light. The reference value is used to determine whether the pattern is valid from the image data. At this time, the operator can check the illuminometer brightness level for a specific part of the displayed printed circuit board unit.

Therefore, the computer system 170 acquires an image using transmitted light or reflected light in an automatic optical inspection system that inspects a printed circuit board in the form of a film or tape using an optical camera, and determines whether it is in conformity with a standard defined as good quality. do. At this time, the pattern component is recognized based on a specific threshold value (eg, illuminometer level 120) that divides the pattern into a space due to defects in the actual pattern or between good and foreign objects and dust. Will be.

However, as in the case of FIGS. 1C and 1D, defects due to non-defective foreign matters are classified into pattern areas by specific binarization values which are divided into patterns and spaces, but are relatively close to binarization values on an optical illuminometer. Is represented by an optical illuminometer (eg, 70 or more levels). 1A and 1B, when the actual pattern is defective, it can be seen that the optical illuminometer (for example, 70 levels or less) is relatively different from the binarization value.

Accordingly, the present invention further distinguishes the region divided by the pattern region based on a specific binarization value that distinguishes the pattern and the space, as a reference value. That is, although it was recognized as a pattern area because it is lower than the binarization value, it is determined that a certain area where the optical illuminometer is relatively close is detected by good quality foreign matter and dust. Will be considered.

It is obvious that this part can be applied to the same principle even when using reflected light. For example, the presence or absence of a defective pattern is determined using the first reference value of the illuminometer 120 level, and if the defective discriminated unit is again determined to be equal to or greater than the second reference value illuminometer 200 level or more, and if it is more than that, in fact, projections, short circuits, etc. It is determined that the defective unit of. And when it is below a 2nd reference value illuminometer 200 level, it determines with the good goods resulting from a good foreign material.

As a result, by detecting only the defect of the actual pattern through the image data obtained by using the transmitted light and / or the reflected light, the productivity is improved by preventing overdetection of determining the actual good as a defect.

5 is a flowchart showing the operation procedure of the automatic optical inspection system according to an embodiment of the present invention. This procedure is a program processed by the computer system 170, which is stored in the storage unit 180.

Referring to the drawing, the computer system 170 acquires image data 182 by an image processing process in step S202 when the flexible printed circuit board is imaged from the AOI 102 in step S200. The image data acquired in step S204 is analyzed to determine whether the unit is good or not using the first reference value. That is, it is determined whether a defect has occurred in the pattern of the unit on the basis of the first reference value of the specific binarization value using a histogram type illuminometer.

Here, the histogram is a method of representing a distribution of contrast values for pixels in image data. Normally, the X-axis of the histogram shows the contrast, and the Y-axis shows the frequency. In the histogram, the value on the X-axis that represents the contrast value is usually divided between 0 and 255 levels. For example, if the histogram graph is near level 0, the brightness is low, and level 255 is high. Hereinafter, the present invention analyzes and describes image data obtained through a histogram using transmitted light.

Accordingly, in step S206, the first reference value is, for example, a reference value of the illuminometer 120 level, and determines a failure of the primary pattern.

Subsequently, in step S208, the image data determined to be defective by the first reference value determines whether the unit determined to be defective actually has a defective pattern or is overdetected by a foreign matter or the like.

As a result of the determination, if it is determined that the level is equal to or less than the second reference value, the procedure proceeds to step S210 to determine the actual defective pattern such as short circuit and / or projection. Subsequently, the unit is determined to be defective in step S212.

If the illuminometer level exceeds the second reference value in step S208, the procedure goes to step S214 to determine that it is a good foreign material, and in step S216 the corresponding unit is determined as good quality.

As described above, the automatic optical inspection system of the present invention secondly determines whether the first defective unit is determined by using different reference values of the brightness illuminometer.

Subsequently, analysis screens using the histogram method according to an embodiment of the present invention are shown in FIGS. 6 to 8. These screens are output to the display device 174 of the computer system 170 and are driven by the histogram analysis program 186 for analysis according to the illuminometer level.

Referring to FIG. 6, the screen 400 is a diagram illustrating a part of the image data 182 captured by the automatic optical inspector 102. The screen 400 is divided into a lead 420 and a space 422, and includes a protrusion or a short circuit. The actual defective pattern 404 and the inspection result by the foreign matter 406 are output. In addition, on one side, a distribution chart 410 of the illuminometer is shown using a histogram method.

Referring to FIG. 7, a binarization screen is shown in pixel units of image data according to binarization values to determine whether a pattern is determined from the screen of FIG. 6. The lead 420 and the space 422 are divided and displayed by the binarization value, and represent the inspection results of the projections, the short circuits 404 'and the foreign matter 406'. In this case, when a pixel of a specific position is selected, the illuminometer level of the region 412 including the corresponding pixel of the protrusion, the short circuit, or the foreign material is output through the auxiliary window 430, as shown in FIG. You can check the brightness illuminance level on the image.

As described above, according to the present invention, by using the subdivided binarization reference values, the unit which is over-detected as the defect by the foreign matter, rather than the defective unit is discriminated as good quality, thereby preventing over-detection and thus inspecting efficiency and productivity in the inspection process. To improve.

Claims (18)

delete An automatic optical inspection system for inspecting whether a plurality of printed circuit boards having a circuit pattern and a space is defective in the circuit pattern: An automatic optical inspector for obtaining image data corresponding to each of the printed circuit boards by using the transmitted light; Accepting the image data from the automatic optical inspector, and determining each of the image data by a brightness illuminometer in units of pixels at a first brightness level identifying the circuit pattern and the space, If the circuit pattern of the printed circuit board is determined to be defective by the first brightness level, the defect is determined by using a second brightness level that is smaller than the first brightness level and corresponds to an actual defective pattern. A control unit for secondaryly determining whether the circuit pattern is actually defective; If the brightness level of the circuit pattern determined as the defect is between the first and the second brightness level, the controller determines that the defect of the circuit pattern is due to a good quality foreign material, and determines the defective printed circuit board. Automatic optical inspection system, characterized in that discriminated by good quality. The method of claim 2, The control unit; And if the brightness level of the circuit pattern determined as the defect is less than or equal to the second brightness level, determining the circuit pattern as an actual defect and determining the defective printed circuit board as a defect. An automatic optical inspection system for inspecting whether a plurality of printed circuit boards having a circuit pattern and a space is defective in the circuit pattern: An automatic optical inspector for obtaining image data corresponding to each of the printed circuit boards by using reflected light; Accepting the image data from the automatic optical inspector, and determining each of the image data by a brightness illuminometer in units of pixels at a first brightness level identifying the circuit pattern and the space, If the circuit pattern of the printed circuit board is determined to be defective by the first brightness level, the defect is determined by using a second brightness level that is larger than the first brightness level and corresponds to an actual defective pattern. A control unit for secondaryly determining whether the circuit pattern is actually defective; If the brightness level of the circuit pattern determined as the defect is between the first and the second brightness level, the controller determines that the defect of the circuit pattern is due to a good quality foreign material, and determines the defective printed circuit board. Automatic optical inspection system, characterized in that discriminated by good quality. The method of claim 4, wherein The control unit; And if the brightness level of the circuit pattern determined as the defect is greater than or equal to the second brightness level, the circuit pattern is discriminated as an actual defect and the printed circuit board determined as the defect is discriminated as a defect. . The method according to claim 2 or 4, The control unit is provided with a computer system, And the computer system mutually transmits the image data and the secondary discrimination information through the automatic optical inspector and a computer network. The method of claim 6, The control unit; And a program for extracting brightness levels in pixel units of the image data. delete delete delete delete delete delete delete In the inspection method for preventing overdetection of discriminating a good product as defective in an automatic optical inspection system for inspecting a circuit pattern of a printed circuit board in the form of a film and a tape: Imaging the printed circuit board using a light source; Acquiring image data corresponding to the printed circuit board; Determining whether the printed circuit board is positive or negative based on a first reference value for identifying the circuit pattern according to the brightness level of the pixel unit; Determining an actual failure state of the printed circuit board determined by the first reference value as a second reference value of a brightness level corresponding to an actual failure pattern; In the determining of the defective state when the light source is transmitted light, the second reference value is provided at a brightness level smaller than the first reference value, and the brightness levels of the circuit pattern determined as the defective value are the first and the second values. If it is between the reference values, the inspection method of the automatic optical inspection system, characterized in that it is determined that the printed circuit board is determined as good quality by the good foreign matter. The method of claim 15, The determining of the defective state may include; And if the brightness level of the circuit pattern of the printed circuit board that is determined to be defective by the first reference value is less than the second reference value, the printed circuit board that is determined to be defective is determined as an actual failure. How to check the system. In the inspection method for preventing overdetection of discriminating a good product as defective in an automatic optical inspection system for inspecting a circuit pattern of a printed circuit board in the form of a film and a tape: Imaging the printed circuit board using a light source; Acquiring image data corresponding to the printed circuit board; Determining whether the printed circuit board is positive or negative based on a first reference value for identifying the circuit pattern according to the brightness level of the pixel unit; Determining an actual failure state of the printed circuit board determined by the first reference value as a second reference value of a brightness level corresponding to an actual failure pattern; The determining of the defective state may include the second reference value having a brightness level greater than the first reference value when the light source is reflected light, and the brightness levels of the circuit pattern determined as the defective value being the first and the second reference values. If it is between the reference value, the inspection method of the automatic optical inspection system, characterized in that it is determined that the printed circuit board is determined as good quality by the good foreign matter. The method of claim 17, The determining of the defective state may include; The inspection of the automatic optical inspection system, characterized in that the printed circuit board, which is determined to be defective, is determined to be an actual failure when the brightness level of the circuit pattern of the printed circuit board that is determined to be defective by the first reference Way.

Images