JPH10307005A - Length measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a length measuring apparatus which can be miniaturized and which shortens the inspection time of an object, to be measured, by a method wherein a measuring base, an illumination means, an image capture means, a movement means and an output means are used in common in a pattern inspection unit and a length measuring unit. SOLUTION: An object W to be measured is placed on a measuring base 1, and it is illuminated with an illumination means. An image capture means 7 and the object W to be measured are moved relatively by a movement means 11, and the image of the object W to be measured is fetched. A pattern is inspected by a pattern inspection unit, and a result is output to an output means 53. In addition, while the object W to be measured is placed on the measuring base 1, the image capture means 7 and the object W to be measured are moved relatively, the image of the object W to be measured is fetched, the dimensions and the coordinates of the object W to be measured are measured by a length measuring unit, and a result is output to the output means 53. The measuring base 1, the illumination means, the image capture means 7, the movement means 11 and the output means 53 are used in common in the pattern inspection unit and the length measuring unit, a length measuring apparatus can be miniaturized, and it is not required to replace the setup of the object W to be measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an original plate for producing a printed wiring board, an original plate for producing a glass mask for printing a predetermined pattern on a liquid crystal display device or a semiconductor wafer, a printed material requiring high precision, and the like. The present invention relates to a length measuring device used for measuring dimensions, coordinate positions, and the like of a figure.

[0002]

2. Description of the Related Art Conventionally, an original plate for forming a printed wiring board for forming a predetermined pattern on a printed wiring board is inspected using a separate pattern inspection apparatus and a length measuring apparatus, for example, as follows. ing.

First, an original plate to be measured is set on a measuring table of a "pattern inspection apparatus", and an image capturing unit such as a CCD camera and a measuring table are relatively moved by a moving unit, and a pattern inspection is performed based on the captured image. Pinholes, bridges, cuts, and patterns formed on the original plate by the unit
Inspect for defects such as chips, scratches, dirt, and dust. If there is a defect as described above, the coordinates are stored and a marker is used to mark the location. If the defect can be corrected, the pattern is corrected and the pattern inspection is performed again. If the defect cannot be corrected, the original plate is discarded.

[0004] Then, only the original plate which has become a non-defective product by the above pattern inspection is set on a measuring table of a "length measuring device", and C
The image capturing unit such as a CD camera and the measuring table are relatively moved by the moving unit, and based on the captured image, the dimensions and pattern coordinates of the pattern formed on the original plate are measured by the length measuring unit, and the design value is allowed. It checks whether it is within the error.

[0005] Then, a predetermined pattern is formed on a substrate by using only a non-defective original plate to produce a printed wiring board.

[0006]

However, in the case of such a conventional example, there are the following problems. That is, since it is necessary to use separate “pattern inspection devices” and “length measurement devices” for pattern inspection and length measurement, respectively, an installation space for two devices is required,
Inspection requires the purchase cost of two devices, and the initial investment is large.

Further, since the work of setting the original plate in the apparatus needs to be performed twice, there is a problem that the work until the series of inspections is completed becomes complicated and the inspection time becomes long.

The present invention has been made in view of such circumstances, and by providing the functions of pattern inspection and length measurement, installation space and initial investment can be reduced.
It is an object of the present invention to provide a length measuring device that can simplify inspection work and shorten inspection time.

[0009]

The present invention has the following configuration in order to achieve the above object. That is, the length measuring device according to claim 1 captures an image of the measurement object, a measurement table on which the measurement object is mounted, illumination means for illuminating the measurement object mounted on the measurement table. Image capturing means, moving means for relatively moving the object to be measured and the image capturing means in a plane parallel to the measuring table,
A relative position of the object to be measured by the moving unit, and a pattern inspection unit that inspects a pattern of the object to be measured based on an image captured through the image capturing unit; Move,
A length measuring unit that measures dimensions and coordinates of the object to be measured based on an image captured through the image capturing unit; a result of inspecting the object to be measured by the pattern inspection unit; And output means for outputting a result of measuring the length of the measurement object.

According to a second aspect of the present invention, in the length measuring apparatus according to the first aspect, the illuminating means includes an intermittent light emitting means for pattern inspection, a constant light emitting means for length measuring, An optical fiber for guiding light to the object to be measured, and a light selecting means for selectively guiding one of the intermittent light emitting means and the steady light emitting means to the optical fiber.

According to a third aspect of the present invention, in the length measuring device according to the first or second aspect, the image capturing means is disposed above the measuring table, and the illuminating means is provided. It is characterized by being arranged below the measuring table.

According to a fourth aspect of the present invention, in the length measuring apparatus according to any one of the first to third aspects, based on an inspection result by the pattern inspection unit, a defective portion on the workpiece is measured. The apparatus further comprises a marking mechanism for performing marking.

[0013]

The operation of the first aspect of the invention is as follows. The object to be measured is placed on the measuring table, the object to be measured is illuminated by the illuminating means, and the image capturing means and the object to be measured are relatively moved by the moving means to capture the image of the object to be measured. The pattern is inspected by the pattern inspection unit based on the captured image, and the result is output to the output means. Also,
The image capturing means and the object to be measured are relatively moved by relative movement while the object to be measured is mounted on the measuring table, the image of the object to be measured is captured, and the dimensions and coordinates of the object to be measured are measured by the length measuring unit. And outputs the result to the output means. As described above, since the measuring table, the illuminating means, the image capturing means, the moving means, and the output means are shared by the pattern inspection unit and the length measuring unit, the size of the apparatus can be reduced and the cost can be reduced. In addition, the setting of the object to be measured on the measuring table only needs to be performed once, so that there is no need to change the setup of the object to be measured.

According to the second aspect of the present invention, the illuminating means is configured so that the intermittent light emitting means for pattern inspection and the steady light emitting means for length measurement are selectively guided to the optical fiber by the light selecting means. Therefore, an appropriate illumination can be selected during the pattern inspection processing and the length measurement processing.

According to the third aspect of the present invention, since the image capturing means is provided above the measuring table and the illuminating means is provided below the measuring table, light such as a film original for producing a printed circuit board is provided. The transparent object to be measured can be appropriately inspected.

According to the fourth aspect of the present invention, the defect is marked by the marking mechanism.
The presence or absence and size of a defect can be easily known only by looking at the test object after inspection.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an external perspective view showing a schematic configuration of a length measuring device according to an embodiment, FIG. 2 is a perspective view showing a schematic configuration of a moving unit, and FIG. 3 is a perspective view showing a schematic configuration of an image capturing unit. is there. FIG. 4 shows a block diagram of the apparatus. In the following description, an original plate or a printed material for producing a printed wiring board is referred to as an object to be measured.

A measuring table 1 made of a light-transmitting material such as glass and having a plate-like shape on which an object to be measured W is placed has an operation panel 3 including various switches for operating the apparatus. It is arranged on the upper surface of the body 5 in a horizontal posture. Above the measuring table 1, an image capturing means 7 is mounted via an X-direction driving base 9, and is moved in the X direction by an image capturing means driving loop 10 as shown in FIG. . The X-direction drive base 9 is moved in the Y-direction together with the image capturing means 7 by a Y-direction drive unit 11 built in the upper surface of the apparatus housing 5. The image capturing means 7 is moved within the Y plane. Note that the above-described image capturing unit driving loop 10 and Y-direction driving unit 11 correspond to the moving unit of the present invention.

Below the measuring table 1, a light projecting unit 13 having a reflecting mirror 13a at a position facing the image capturing means 7 is provided.
Are arranged. As shown in FIG. 4, the light projecting section 13 has a two-branch light guide 1 via an optical fiber 15.
7 is connected to the two-branch light guide 17,
Halogen lamp 19 that emits steady light for length measurement, and Xe lamp (xenon lamp) 2 that emits light intermittently for pattern inspection
1 are connected. The intermittent light emission operation of the Xe lamp 21 is controlled by the Xe lamp controller 23. Note that the light projecting unit 13 corresponds to the illuminating means of the present invention, the halogen lamp 19 corresponds to the steady light emitting means, and the Xe lamp 21 and the Xe lamp controller 23 correspond to the intermittent light emitting means.

As shown in FIG. 2, the light projecting unit 13 is operatively connected to a lower part of a light projecting unit driving loop 25 which forms a loop so as to surround the measuring table 1. An upper part of the drive loop 25 is operatively connected to a lower side of the image capturing means drive loop 10 by an engagement fitting 26. Therefore, when the image capturing means 7 moves in the direction of arrow A, the light projecting section driving loop 2 engaged with the lower side of the image capturing means driving loop 10 by the engagement fitting 26.
5 moves in the opposite direction.
3 moves by the same distance in the same direction as the arrow A, and the image capturing means 7 and the light projecting unit 13 are always
Will move in a state of facing each other.

As shown in FIG. 3, the image capturing means 7 has a CCD camera 29 at an upper portion of a lens barrel 27 including an objective lens, and has a ring-shaped reflection illuminator 31 at a lower portion thereof. The reflection illuminator 31 is connected to a light source (not shown) via an optical fiber 31a (FIG. 1). Further, at two positions on the outer peripheral portion of the reflection illumination section 31, there are provided marking mechanisms 33 in which the markers M are stored so as to be able to advance and retreat in the vertical direction. The marking mechanism 33 is controlled by a marker controller 35, and the lower end of one of the markers M is brought into contact with the workpiece W as indicated by a two-dot chain line in FIG. In addition, marking is applied to a defective portion.

An image signal from the CCD camera 29 is output to a distributor 37 and separated into two signals. One is output to an image capturing unit 39 of the length measuring unit U1, and the other is an image inspecting unit of the pattern inspection unit U2. It is output to 41. The control unit 43 constituting the length measuring unit U1 controls each unit described later, and also controls the pattern inspection unit U2.
(Xe lamp controller 23, marker controller 35, image inspection unit 41) are also controlled.

The length measuring unit U1 drives the above-mentioned light projecting unit drive loop 25 in addition to the above-mentioned operation panel 3 and image take-in unit 39, and drives the image take-in unit 7 through the image take-up unit drive loop 10 to X. X-axis servo motor 45a for moving in the X-direction and Y-axis servo motor 4 for driving the Y-direction drive unit 11 to move the X-direction drive base 9 in the Y direction.
5b is controlled based on a control signal from the controller 43, an encoder 49 for detecting a moving distance corresponding to the rotation amount of the X-axis / Y-axis servomotors 45a and 45b, and an encoder 49 for detecting A coordinate reading unit 51 that reads the coordinates of a specific position in the visual field captured by the image capturing unit 7 based on the moving distance, and outputs an image within the visual field of the image capturing unit 7;
And a CRT 53 that outputs the results of the pattern inspection process and the length measurement process.

The constant light emission for length measurement by the halogen lamp 19 and the intermittent light emission by the Xe lamp 21 and the Xe lamp controller 23 are controlled by the control unit 43 in accordance with the inspection processing contents instructed by the operator from the operation panel 3. Selected by. In other words, when the length measurement process is instructed, the halogen lamp 19 is controlled to illuminate the object to be measured W by steady light emission, and when the pattern inspection process is instructed, the Xe is transmitted through the image inspection unit 41. By controlling the lamp controller 23, the device under test W is illuminated by intermittent light emission. Therefore, the light incident on the two-branch light guide 17 is selected by the control unit 43,
The control unit 43 corresponds to the light selection unit of the present invention.

The control unit 43 controls only the illumination from below by the halogen lamp 19 and the light projecting unit 13 based on the instruction from the operation panel 3 by the operator only when the inspection content is the length measurement process. It is possible to switch between illumination only from above by the reflective illumination unit 31 and illumination from above and below by combining them.

Next, a series of processing by pattern inspection processing and length measurement processing by the above-described apparatus will be described with reference to the flowchart of FIG. In the following description, a case where the pattern inspection process is performed first and then the length measurement process is performed will be described as an example, but the order of the inspection process may be reversed. In the following description, measurement is automatically performed according to a program. However, even if a manual method in which an operator sequentially designates measurement points without using a program is used, inspection and measurement can be performed with this apparatus. Needless to say, there is.

Step S1 (setting of the object to be measured) The object to be measured W is set on the upper surface of the measuring table 1. For example, the device under test W is placed along a reference line drawn at a specific location on the measuring table 1.

Step S2 (Instruction of Pattern Inspection Method) Next, the operator selects a program created and stored in advance through the operation panel 3 in accordance with the pattern inspection processing of the workpiece W, or if necessary. For example, the user designates parameters such as the type of image to be captured (negative / positive) and its white / black threshold value. Alternatively, the user instructs an inspection method such as newly creating / partially changing the pattern inspection processing program or designating the inspection start position while moving the image capturing means 7 to an appropriate position via the operation panel 3.

Step S3 (Pattern Inspection Processing) When the operator instructs the start of the pattern inspection processing via the operation panel 3, the control unit 43 performs the pattern inspection based on the pattern inspection method including the program instructed in step S2. The unit U2 is instructed to start processing. The control unit 43 controls the X-axis / Y-axis servo motors 45a and 45b via the servo motor controller 47 described above, and reads the coordinates from the coordinate reading unit 51 while moving the image capturing unit 7 to a position corresponding to the program. Move automatically. The image capturing means 7 includes a light emitting unit 13
It captures the pattern image of the device under test W illuminated by the intermittent irradiation light of the Xe lamp 21 radiated from the Xe lamp 21, and outputs an image signal to the image inspection unit 41. The image inspection unit 41 performs image processing according to the program on the image signal of the pattern, and automatically determines the quality of the pattern based on the image. As a result of the pattern inspection, the coordinates of the specific portion determined to be defective are stored in a memory (not shown) built in the image inspection unit 41, and the marker mechanism 33 marks the position.

Step S4 (Result Display) When the pattern inspection process is completed, the result is output from the image inspection unit 41 to the control unit 43, and is output from the control unit 43 to the CRT 53 in a predetermined format. The operator looks at the result display, or looks at the marking on the DUT W, and determines whether or not to perform the length measurement process. Here, the description will be made on the assumption that there is no defect in the pattern of the object to be measured W and the length measurement processing is continuously performed.

Step S5 (Instruction of Length Measurement Method) Next, the operator does not remove the object W from the
A program created and stored in advance is selected in accordance with the length measurement processing, and if necessary, a lower-only / upper-only / upper / lower illumination method is designated. Is moved to an appropriate position, a new measurement position is specified, and an inspection method such as specifying an inspection start position is specified. At this point, the Xe lamp 2
The power supply to 1 is shut off, and power is supplied to the halogen lamp 19 instead.

Step S6 (Length measurement processing) In accordance with the length measurement method instructed, the control unit 43 moves the image capturing means 7 and illuminates the object to be measured illuminated by the light projecting unit 13 and / or the reflection irradiating unit 31. The dimensions and coordinates of the pattern formed at a specific portion of W are automatically measured.

Step S7 (Result Display) The measurement result is formed into a predetermined format by the control unit 43 and output to the CRT 53. The operator determines whether or not the measured object W is defective by looking at the result display. Note that, depending on the program, it is possible to output only good / bad data to the CRT 53 by comparing with a preset normal value.

As described above, by incorporating the pattern inspection unit in the length measuring apparatus, the measuring table 1, the image taking means 7, the moving means including the X-axis / Y-axis servo motors 45a and 45b, and the CRT 53 are combined with the length measuring unit. Since U1 and the pattern inspection unit U2 can be shared, the size of the apparatus can be reduced and the cost can be reduced. Therefore, the installation space for the device can be reduced, and the purchase cost of the device can be significantly reduced.

Further, since the pattern inspection and the length measurement can be performed by the same apparatus, the workpiece W can be set on the measuring table 1 only once, and the setup of the workpiece W is not required. Therefore, the labor of the inspection can be simplified, and the inspection time can be shortened. Furthermore, since the inconvenience that the position of the workpiece W is slightly shifted due to the setup change can be prevented, improvement in inspection accuracy can be expected.

In the above description, the length measurement is performed after the pattern inspection. However, after the pattern inspection of a certain location is performed, the length measurement of the location is performed, and after moving to another location, the pattern is similarly measured. It is also possible to execute the pattern inspection and the length measurement simultaneously in parallel, as in the case of performing the inspection / length measurement. If the two processes are performed in parallel in this way, it is expected that the inspection time will be further reduced.

Further, as described above, the image capturing means 7
Measuring table 1 on which workpiece W is placed without moving
May be moved. Measurement table 1
Does not need to be horizontal, and may be inclined or arranged upright.

Although the light projecting section 13 illuminates only the position facing the image capturing means 7, the entire surface of the measuring table 1 may be illuminated. In this case, since the above-described light projecting unit driving loop 25 becomes unnecessary,
The drive system can be simplified.

In the above configuration, the marking mechanism 3
According to 3, the marking is performed on the defect location of the object to be measured based on the result of the pattern inspection processing. However, when the marking of the defect location is only required and the marking is unnecessary, the marking mechanism 33 needs to be provided. There is no.

[0040]

As is apparent from the above description, according to the first aspect of the present invention, the measuring table, the illuminating means, the image capturing means, the moving means and the output means are shared by the pattern inspection unit and the length measuring unit. Therefore, the size of the apparatus can be reduced and the cost can be reduced. Therefore, the installation space of the device can be reduced, and the purchase cost of the device can be reduced.

Further, only one setting of the object to be measured on the measuring table is required, and it is not necessary to change the setup of the object to be measured. Therefore, the labor of the inspection can be simplified, and the inspection time can be shortened. Further, it is possible to prevent the inconvenience that the position of the object to be measured is slightly shifted due to the setup change, so that the inspection accuracy can be improved.

Further, since the pattern inspection and the length measurement can be performed simultaneously in parallel, it is expected that the inspection time can be further reduced.

According to the second aspect of the present invention, an appropriate illumination can be selected at the time of the pattern inspection processing and the length measurement processing, so that each processing can be suitably performed.

According to the third aspect of the present invention, since an object to be measured is illuminated from below and an image is taken in from above, an optically transmissible object to be measured, such as a film base plate for producing a printed circuit board, is used. Objects can be inspected appropriately.

According to the fourth aspect of the present invention, the presence or absence and the size of a defect can be easily known only by looking at the object to be measured after the marking is performed.

[Brief description of the drawings]

FIG. 1 is an external perspective view illustrating a schematic configuration of a length measuring device according to an embodiment.

FIG. 2 is a perspective view showing a schematic configuration of a moving unit.

FIG. 3 is a diagram showing a schematic configuration of an image capturing unit.

FIG. 4 is a block diagram of the device.

FIG. 5 is a flowchart illustrating an example of an operation of the embodiment device.

[Explanation of symbols]

 W: object to be measured 1: measuring table 7: image capturing means 9: X-direction driving gantry 10: image capturing means driving loop (moving means) 11: Y-direction driving section (moving means) 13: light emitting section (illuminating means) 19 ... Halogen lamp (steady light emitting means) 21 ... Xe lamp (intermittent light emitting means) 23 ... Xe lamp controller (intermittent light emitting means) 33 ... marking mechanism 43 ... control unit (light selecting means) U1 ... length measuring unit U2 ... pattern inspection unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Hiroshi Yamashita, Inventor Hiroshi Yamashita 322, Fushimi-ku, Kyoto, Kyoto Prefecture Nippon Screen Manufacturing Co., Ltd. 322 Dai Nippon Screen Manufacturing Co., Ltd.

Claims (4)

[Claims] A measuring table on which the object to be measured is mounted; an illumination unit for illuminating the object to be measured mounted on the measuring table; an image capturing unit for capturing an image of the object to be measured; Moving means for relatively moving the object to be measured and the image capturing means in a plane parallel to and moving the object to be measured relative to the moving means, based on an image captured via the image capturing means. A pattern inspection unit for inspecting a pattern of the object to be measured, and a relative movement of the object to be measured by the moving unit, and measuring a size and coordinates of the object to be measured based on an image captured through the image capturing unit. An output unit for outputting a result of inspecting the object to be measured by the pattern inspection unit and a result of measuring the object to be measured by the length measuring unit. A length measuring device comprising: a step; 2. The length measuring device according to claim 1, wherein the illuminating means includes an intermittent light emitting means for pattern inspection, a steady light emitting means for length measurement, and an optical fiber for guiding light to the object to be measured. A length measuring device comprising: a light selecting means for selectively guiding one of the intermittent light emitting means and the steady light emitting means to the optical fiber. 3. The length measuring device according to claim 1, wherein said image capturing means is arranged above said measuring table, and said illuminating means is arranged below said measuring table. Characteristic length measuring device. 4. The length measuring device according to claim 1, further comprising a marking mechanism for marking a defect location on the measured object based on an inspection result by the pattern inspection unit. A length measuring device characterized by the above-mentioned.