JP2006350012A - Exposure apparatus, exposure method, inspection system, and inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent degradation in inspection accuracy even when an exposure object is distorted. <P>SOLUTION: This exposure apparatus 14 receives Gerber data 36 of a wiring pattern to be transferred by exposure onto an exposure object from a CAD/CAM system 12. An image processing unit 18 detects a position of a reference mark formed on a substrate based on the image data of an image on the substrate captured by a camera 22, determines magnifications in an X direction and a Y direction, corrects the Gerber data 36, and processes the data by an RIP to generate corrected raster data 38. An exposure unit 26 exposes the substrate based on the corrected raster data 38. The image processing unit 18 outputs the corrected raster data 38 to an inspection device 16. The inspection device 16 carries out pattern matching based on scan data obtained by scanning a substrate with the wiring pattern formed thereon by a scanner 28 and based on the corrected raster data, and inspects a defect in the wiring pattern formed on the substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an exposure apparatus, an exposure method, an inspection system, and an inspection method, and more particularly to an exposure apparatus and an exposure method for exposing a circuit pattern to a printed object to be printed, a printed object to be printed on which a circuit pattern is formed, and the like. The present invention relates to an inspection system and an inspection method for inspection.

  Conventionally, in the production of printed circuit boards, circuit pattern data is created using an editing device such as CAD (Computer Aided Design), CAM (Computer Aided Manufacturing), etc., and the printed circuit board is created by an exposure device based on the circuit pattern data. Exposure.

  The printed circuit board on which the circuit pattern has been exposed is chemically processed by a so-called photolithography technique or the like in a process step. In the case of a multilayer substrate, the substrate of each layer is pressed by a pressing process.

  Since dust may be attached or scratched during the production of such a printed circuit board, a circuit pattern formed on the printed circuit board is inspected by a circuit pattern inspection apparatus such as AOI (Automated Optical Inspection). Is common.

  Usually, in a circuit pattern inspection apparatus, circuit pattern data used for exposure in an exposure apparatus, that is, circuit pattern data created by CAD, CAM, etc., and image data obtained by reading a circuit pattern formed on a printed circuit board with a scanner or the like However, if the completed printed circuit board is distorted, it may be judged as a defective product even if the distortion is originally within the allowable range.

For this reason, Patent Document 1 discloses an inspection apparatus that can prevent a determination as a defective product even if the distortion is originally within an allowable range by detecting and correcting the local distortion. Yes.
JP-A-8-35936

  However, for example, when the printed board is a multilayer board, the board may be distorted in a pressing process or the like, and the board may already be distorted before the circuit pattern is exposed on the surface of the printed board. In this case, when exposure is performed using original circuit pattern data created by CAD, CAM or the like as in the prior art, the circuit pattern formed on the printed circuit board is relatively shifted.

  For this reason, in the exposure process, there is a case where circuit pattern data of a circuit pattern obtained by deforming original circuit pattern data created by CAD, CAM, etc. according to the distortion of the printed circuit board is created, and exposure is performed based on this circuit pattern data. is there.

  In such a case, since the circuit pattern actually formed on the printed circuit board is slightly deformed, pattern errors frequently occur when inspection is performed by pattern matching with the original circuit pattern data. For this reason, conventionally, there has been a problem that the inspection standard has to be set loosely and the inspection accuracy is deteriorated.

  In view of the above-described facts, the present invention provides an exposure apparatus, an exposure method, an inspection system, and an inspection method that can prevent deterioration in inspection accuracy even when the object to be exposed is distorted and deformed. Is an issue.

  In order to achieve the above object, the exposure apparatus according to claim 1 includes an input means for inputting pattern data of a predetermined pattern to be exposed on the object to be exposed, and a detecting means for detecting the degree of deformation of the object to be exposed. And generating means for generating correction pattern data based on the pattern data and the degree of deformation, exposure means for exposing the exposure object based on the correction pattern data, and formed on the exposure object. Output means for outputting the correction pattern data or the degree of deformation to an inspection apparatus for inspecting the predetermined pattern.

  According to the present invention, the degree of deformation of the object to be exposed is detected, correction pattern data is generated based on this and the original pattern data, and exposure is performed based on the correction pattern data. The predetermined pattern is also deformed, and the relative deviation between the substrate and the predetermined pattern can be eliminated.

  Since the correction pattern data or the detected degree of deformation is output to the inspection apparatus, the inspection apparatus outputs the predetermined pattern formed on the substrate based on these and an image obtained by imaging the predetermined pattern formed on the substrate. Can be inspected. Accordingly, it is possible to prevent frequent inconsistencies with the original predetermined pattern, and it is possible to prevent the inspection accuracy from deteriorating even when the exposure object is deformed.

  According to a second aspect of the present invention, the detection means includes a reference mark detection means for detecting a plurality of reference marks provided on the object to be exposed, and the object to be detected based on the detected positions of the plurality of reference marks. And a calculating means for calculating the degree of deformation of the exposed object.

  According to a third aspect of the present invention, the degree of deformation includes a magnification of a predetermined length of the object to be exposed, a magnification of a length of the object to be orthogonal to the predetermined direction, It may include at least one of a movement amount of the exposure object in the predetermined direction, a movement amount of the exposure object in the orthogonal direction, and a rotation angle of the exposure object.

  According to a fourth aspect of the present invention, the object to be exposed is a printed circuit board, and the predetermined pattern can be a wiring pattern of a circuit mounted on the printed circuit board.

  The exposure method according to claim 5, wherein pattern data of a predetermined pattern to be exposed is input to the object to be exposed, the degree of deformation of the object to be exposed is detected, and correction is performed based on the pattern data and the degree of deformation. Pattern data is generated, the object to be exposed is exposed based on the correction pattern data, and the correction pattern data or the deformation degree is output to an inspection apparatus that inspects a predetermined pattern formed on the object to be exposed. It is characterized by that.

  According to the present invention, it is possible to prevent the inspection accuracy from deteriorating even when the object to be exposed is deformed.

  7. The inspection system according to claim 6, wherein input means for inputting pattern data of a predetermined pattern to be exposed on the exposure object, detection means for detecting a deformation degree of the exposure object to be exposed, the pattern data and the deformation A generation unit that generates correction pattern data based on the degree, an exposure unit that exposes the object to be exposed based on the correction pattern data, and an imaging unit that images a predetermined pattern formed on the object to be exposed And inspection means for inspecting the predetermined pattern formed on the object to be exposed based on the imaged image data of the predetermined pattern and one of the correction pattern data and the degree of deformation. It is characterized by that.

  According to the present invention, the inspection means images a predetermined pattern formed on the object to be exposed, and on the object to be exposed based on the image data, one of the correction pattern data and the degree of deformation. The formed predetermined pattern is inspected. The inspection can be performed, for example, by pattern matching based on both raster data. Thereby, it is possible to prevent the inspection accuracy from deteriorating even when the exposure object is deformed.

  The inspection method according to claim 7, wherein pattern data of a predetermined pattern to be exposed is input to the object to be exposed, the degree of deformation of the object to be exposed is detected, and correction is performed based on the pattern data and the degree of deformation. Generating pattern data, exposing the object to be exposed based on the correction pattern data, capturing a predetermined pattern formed on the object to be exposed, image data of the captured predetermined pattern, and the correction pattern A predetermined pattern formed on the object to be exposed is inspected based on one of the data and the degree of deformation.

  According to the present invention, it is possible to prevent the inspection accuracy from deteriorating even when the object to be exposed is deformed.

  According to the present invention, there is an effect that it is possible to prevent deterioration in inspection accuracy even when distortion is generated in an object to be exposed.

  Hereinafter, embodiments of the present invention will be described. FIG. 1 shows a schematic configuration of an inspection system 10 according to the present embodiment.

  The inspection system 10 includes a CAD / CAM system 12, an exposure apparatus 14, and an inspection apparatus 16.

  The exposure apparatus 14 includes an image processing unit 18, a correction information input unit 20, a camera 22, a memory 24, and an exposure unit 26.

  The inspection device 16 includes a scanner 28, a comparison unit 30, a memory 32, and a result output unit 34.

  The CAD / CAM system 12 includes a general-purpose personal computer (PC) including a CPU, memory, HDD (hard disk drive), display, keyboard, mouse, and the like.

  Among the CAD / CAM systems 12, the CAD system performs steps such as designing an electronic circuit to be mounted on a printed wiring board, designing a wiring pattern to be formed on the printed wiring board, and the like. Generate.

  Of the CAD / CAM systems 12, the CAM system determines how to arrange (layout) the wiring pattern represented by the data describing the wiring pattern during exposure (drawing) on the substrate, and the substrate in the drilling process. An editing process is performed, such as determining where the hole is to be punched and adding a comment to be drawn together with the wiring pattern. Then, the entire wiring pattern to be drawn on the board in one drawing is drawn in vector format (images such as the coordinates of points such as the start point and end point and the parameters of lines and planes connecting them, fills, special effects, etc.) Image data (hereinafter referred to as Gerber data 36) described in a data format expressed as a set of information is generated, and this Gerber data is transferred to the image processing unit 18 of the exposure apparatus 14. The drilling position on the substrate determined in the editing process is output as drill hole data to a drilling machine (not shown) that drills the substrate.

  In the present embodiment, in order to calculate the degree of deformation of the substrate, perforations as reference marks are provided by a drilling machine (not shown) at a plurality of predetermined positions on the substrate. The reference mark is not limited to perforation, and may be a groove, a printed symbol, a character, a figure, or the like.

  The image processing unit 18 of the exposure apparatus 14 stores the Gerber data 36 input from the CAD / CAM system 12 in the memory 24.

  A camera 22 is connected to the image processing unit 18. The camera 22 is configured to include an image sensor such as a CCD, and images the surface of the substrate provided with a plurality of reference marks and outputs the image to the image processing unit 18.

  The image processing unit 18 detects the position of the reference mark based on the image data of the image taken by the camera 22. For this detection, for example, information indicating the position of the reference mark on a standard substrate without deformation is stored in advance in a memory (not shown), and information indicating the position of the reference mark in the image data input from the camera 22 is used. It can be detected by extracting an image having a reference mark shape (for example, a circle) from image data corresponding to a region within a predetermined range including the indicated position. For the detection of the reference mark, for example, a method described in JP-A-2005-37911 can be used.

  The position of the reference mark thus obtained may be deviated from the position where no deformation has occurred due to deformation of the substrate due to, for example, a pressing process.

  When a wiring pattern is formed by exposing the deformed board based on the original Gerber data 36, the resulting printed wiring board has a shift in the relative position of the wiring pattern with respect to the board. become.

  Therefore, the image processing unit 18 corrects the Gerber data 36 in accordance with the degree of deformation of the substrate, and further generates corrected raster data 38 obtained by performing RIP (Raster Image Processor) processing and stores the corrected raster data 38 in the memory 24.

  Further, a correction information input unit 20 is connected to the image processing unit 18 and, for example, parameters to be corrected for the wiring pattern, for example, correction information such as the line width of the wiring pattern can be input by a user operation or the like. Thereby, the line width of the wiring pattern can be easily changed without redesigning with the CAD / CAM system 12.

  When the correction information is input by the correction information input unit 20, the image processing unit 18 corrects the original Gerber data 36 based on the correction information and the degree of deformation of the substrate, and the corrected raster data 38 obtained by RIP processing is corrected. Generate.

  The exposure unit 26 exposes the substrate based on the corrected raster data 38. The generated corrected raster data 38 is output to the inspection device 16. The inspection device 16 stores the corrected raster data 38 input from the exposure device 14 in the memory 32.

  The exposure unit 26 directly draws the wiring pattern represented by the corrected raster data 38 input from the image processing unit 18 on a substrate having a surface coated with a photosensitive material.

  The exposure unit 26 draws a wiring pattern on the substrate by irradiating the substrate with a light beam modulated according to the drawing raster data using a spatial light modulator such as a digital micromirror device (DMD). An exposure apparatus having such a configuration can be used.

  A substrate on which a wiring pattern is drawn by the exposure unit 26 is a printed wiring board on which a circuit element can be mounted by forming a wiring pattern through a known process such as development, etching, cleaning, cutting, and drilling by a so-called photolithography technique. (PWB) is formed. As the exposure unit 26, for example, an exposure apparatus described in JP-A-2005-37911 can be used.

  The produced printed wiring board is inspected for its wiring pattern by the inspection device 16.

  First, in the inspection process, the scanner 28 images a wiring pattern on the printed wiring board. Scan data of the scanned image is output to the comparison unit 30 as, for example, raster data.

  The comparison unit 30 performs pattern matching between the corrected raster data 38 input from the exposure apparatus 14 and stored in the memory 32 and the scan data input from the scanner 28, and is formed on the printed circuit board. It is inspected whether the defect of the wiring pattern is within an allowable range.

  The inspection result is output by the result output unit 34. The result output unit 34 is configured by, for example, a display, a printer, or the like, and outputs the inspection result by displaying it on the display or printing it on a sheet by the printer.

  Next, as operations of the present embodiment, control executed by the exposure apparatus 14 and control executed by the inspection apparatus 16 will be described with reference to flowcharts shown in FIGS.

  First, the control executed by the image processing unit 18 of the exposure apparatus 14 will be described with reference to the flowchart shown in FIG. This process is executed when, for example, an exposure start is instructed from an upstream process apparatus or when an exposure process is instructed by an operation unit (not shown).

  In step 100, correction information input processing is performed. For example, a screen that prompts input of correction information is displayed on a display unit (not shown) of the exposure apparatus 14. When the user inputs correction information, the correction information is stored in the memory 24. The correction information includes, for example, information on the line width of the wiring pattern, but is not limited thereto.

  In step 102, the camera 22 is instructed to image the substrate to be exposed, the captured image data is captured, and the position of the reference mark formed on the substrate is detected based on this image data. As described above, this can be detected by, for example, extracting an image having a reference mark shape.

  In step 104, the degree of deformation of the substrate is calculated based on the detected position of the reference mark. The degree of deformation includes a magnification in a predetermined direction of the substrate.

  For example, as shown in FIG. 4A, when four reference marks A to D are provided at the four corners of the substrate 40, the substrate 40 is deformed, and the position of each reference mark is changed as shown in FIG. For example, a case where the reference marks A ′ to D ′ are shifted to the positions will be described.

  In this case, the distance between the reference mark B before deformation and the reference mark D is X1, the distance between the reference mark B ′ after deformation and the reference mark D ′ is X2, and the reference mark A ′ after deformation and the reference mark C ′ are The distance (X3) in the X direction (expansion / contraction ratio) XA is obtained by the following equation, for example.

XA = ((X2 + X3) / 2) / X1 (1)
Further, the distance between the reference mark A before deformation and the reference mark B is Y1, the distance between the reference mark A ′ after deformation and the reference mark B ′ is Y2, and the distance between the reference mark C ′ after deformation and the reference mark D ′ is With the distance as Y3, the magnification YA in the Y direction is obtained by the following equation, for example.

YA = ((Y2 + Y3) / 2) / Y1 (2)
Not only the magnification in the X and Y directions, but also the amount of movement in the X direction of the area surrounded by each reference mark based on the position of each reference mark before deformation and the position of each reference mark after deformation, Y The amount of movement in the direction and the amount of rotation (rotation angle) may be calculated as the degree of deformation.

  In step 106, the Gerber data 36 is corrected based on the input correction information, the X-direction magnification XA and the Y-direction magnification YA calculated in step 104. That is, if the input correction information is line width information, the line width of the wiring pattern is corrected in accordance with the input line width information. Further, the length in the X direction of each wiring pattern is multiplied by XA, and the length in the Y direction is multiplied by YA. Thereby, the wiring pattern is also deformed in accordance with the deformation of the substrate, and the displacement of the relative position between the substrate and the wiring pattern can be almost eliminated.

  The corrected Gerber data is RIP processed to generate corrected raster data 38 and stored in the memory 24. Further, the generated corrected raster data 38 is output to the inspection device 16 and also output to the exposure unit 26.

  As a result, the exposure unit 26 exposes the substrate based on the corrected raster data 38. The exposed substrate is then subjected to development processing, etching processing, and the like in a process step, and is formed as a printed wiring board.

  In the inspection device 16, for example, when a printed wiring board on which a wiring pattern is formed is set and an inspection start is instructed from an upstream process device, or an inspection process is instructed by an operation unit (not shown), FIG. The processing shown is executed.

  First, in step 200, the wiring pattern on the printed wiring board is imaged by the scanner 28, and scan data of the captured image is output to the comparison unit 30 as raster data.

  In step 202, the comparison unit 30 performs pattern matching processing based on the corrected raster data 38 input from the exposure apparatus 14 and the scan data input from the scanner 28. For example, it is determined whether or not the pixel data matches for each of the corresponding pixels of both, and an area where the pixel data does not match is obtained. Then, it is determined whether or not the number and size of the regions are within a predetermined allowable range. If the number is within the allowable range, the inspection is determined to be acceptable, and if the number is not within the allowable range, the inspection is determined to be unacceptable. The inspection method is not limited to the above, and a mismatch between the wiring pattern formed on the substrate represented by the image data scanned by the scanner 28 and the wiring pattern represented by the corrected raster data is detected. Any method can be used as long as it can be determined whether or not it is within the allowable range.

  In step 204, the test result is output by the result output unit 34. As a result, the operator can easily check the inspection result.

  The generation of the corrected raster data 38 by the exposure device 14 and the output to the inspection device 16 may be performed for each substrate. In this case, for example, identification IDs indicating individual substrates are attached to the substrates in advance by numbers, symbols, etc., or by barcodes, etc., which are read by the exposure device 14 and output to the inspection device 16 together with the corrected raster data. Then, the inspection device 16 reads the identification ID attached to the substrate and performs pattern matching based on the corrected raster data corresponding to the read identification ID. Thereby, it can test | inspect precisely for every board | substrate.

  As described above, in the present embodiment, the exposure apparatus 14 obtains the degree of deformation of the substrate, corrects the original Gerber data 36 based on the degree of deformation and correction information input by the user, and performs a RIP process on the corrected raster. Data is generated and output to the inspection device 16. The inspection device 16 inspects the defect of the wiring pattern by performing pattern matching based on the scan data obtained by scanning the corrected raster data and the substrate on which the wiring pattern is formed. Even if it is not loosened, frequent occurrence of pattern errors can be prevented, and deterioration of inspection accuracy can be prevented.

  In the above description, the reference marks are provided at the four corners of the substrate. However, the present invention is not limited to this, and the reference marks may be provided in a lattice shape as shown in FIG. In this case, the position of each reference mark is detected, and each grid area, that is, a region surrounded by the reference marks A, B, E, and D, a region surrounded by the reference marks B, C, F, and E, the reference mark The magnification in the X direction and the magnification in the Y direction are calculated for each of the regions surrounded by D, E, H, and G and the regions surrounded by the reference marks E, F, I, and H, and the wiring pattern magnification in each region is corrected. do it. Further, corrected raster data may be generated by correcting (converting) the wiring pattern of each region using the method described in Japanese Patent Application Laid-Open No. 2005-37911.

  In the present embodiment, the exposure device 14 generates corrected raster data and outputs the corrected raster data to the inspection device 16. However, instead of the corrected raster data, the Gerber data 36 and the calculated deformation degree information are inspected. You may make it output to. The Gerber data 36 may be directly output from the CAD / CAM system 12 to the inspection device 16. In this case, the inspection apparatus 16 may be provided with a RIP processing unit, and the Gerber data 36 may be corrected based on the input information on the degree of deformation, and the RIP processing unit may perform RIP processing to generate corrected raster data.

It is a block diagram which shows schematic structure of a test | inspection system. It is a flowchart of control performed by the image processing unit of the exposure apparatus. It is a flowchart of the control performed with an inspection apparatus. It is a top view of the board | substrate which shows the example of arrangement | positioning of a reference mark. It is a figure for demonstrating calculation of a magnification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inspection system 12 CAD / CAM system 14 Exposure apparatus 16 Inspection apparatus 18 Image processing part (detection means, production | generation means, output means)
20 Correction information input unit 22 Camera (detection means)
24 memory 26 exposure part (exposure means)
28 Scanner 30 Comparison unit 32 Memory 34 Result output unit 36 Gerber data 38 Correction raster data (correction pattern data)
40 Substrate (object to be exposed)

Claims (7)

An input means for inputting pattern data of a predetermined pattern to be exposed on the object to be exposed;
Detecting means for detecting the degree of deformation of the object to be exposed;
Generating means for generating correction pattern data based on the pattern data and the degree of deformation;
Exposure means for exposing the object to be exposed based on the correction pattern data;
Output means for outputting the correction pattern data or the degree of deformation to an inspection apparatus for inspecting a predetermined pattern formed on the object to be exposed;
An exposure apparatus comprising: The detection means includes a reference mark detection means for detecting a plurality of reference marks provided on the object to be exposed;
Calculating means for calculating the degree of deformation of the object to be exposed based on the detected positions of the plurality of reference marks;
The exposure apparatus according to claim 1, further comprising:   The degree of deformation includes a magnification of a predetermined length of the object to be exposed, a magnification of a length of the object to be orthogonal to the predetermined direction, and an amount of movement of the object to be exposed in the predetermined direction. The exposure apparatus according to claim 1, wherein the exposure apparatus includes at least one of a movement amount of the object to be exposed in the orthogonal direction and a rotation angle of the object to be exposed.   4. The exposure according to claim 1, wherein the object to be exposed is a printed circuit board, and the predetermined pattern is a wiring pattern of a circuit mounted on the printed circuit board. apparatus. Input pattern data of a predetermined pattern to be exposed on the object to be exposed,
Detect the degree of deformation of the object to be exposed,
Based on the pattern data and the degree of deformation, generate correction pattern data,
Based on the correction pattern data, the object to be exposed is exposed,
Outputting the correction pattern data or the degree of deformation to an inspection apparatus for inspecting a predetermined pattern formed on the object to be exposed;
Exposure method. An input means for inputting pattern data of a predetermined pattern to be exposed on the object to be exposed;
Detecting means for detecting the degree of deformation of the object to be exposed;
Generating means for generating correction pattern data based on the pattern data and the degree of deformation;
Exposure means for exposing the object to be exposed based on the correction pattern data;
Imaging means for imaging a predetermined pattern formed on the object to be exposed;
Inspection means for inspecting a predetermined pattern formed on the object to be exposed based on the image data of the captured predetermined pattern, and either one of the correction pattern data and the degree of deformation;
Inspection system equipped with. Input pattern data of a predetermined pattern to be exposed on the object to be exposed,
Detect the degree of deformation of the object to be exposed,
Based on the pattern data and the degree of deformation, generate correction pattern data,
Based on the correction pattern data, the object to be exposed is exposed,
Image a predetermined pattern formed on the object to be exposed,
Inspecting the predetermined pattern formed on the object to be exposed based on the image data of the captured predetermined pattern and either the correction pattern data or the degree of deformation.
Inspection method.

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