JP2003042971A - Pattern inspection device and inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pattern inspection device and an inspection method, capable of acquiring reflected light having imageable brightness, even from a copper plated pattern which hardly has gloss being polished chemically. SOLUTION: This device is provided with a light source part 12 having three lamp units 31, 31, 31, a linear light guide 11 for irradiating linear lights by mixing at random light inputted from the three lamp units 31, 31, 31 at an irradiation end, a cylindrical lens 14 for converging the light irradiated from the linear light guide 11, and a glass-based diffusion plate 15 for diffusing the irradiated light which is converged by the cylindrical leans 14. Each lamp unit 31 is provided with a lamp 32 and a color filter 33 for cutting a shorter wavelength component, having the reflectance from a base material of irradiated light from the lamp 32, which is shorter than the reflectance from the pattern.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern inspection apparatus and an inspection method for inspecting the quality of a pattern formed on the surface of a printed wiring board, an IC package or the like. More specifically, the present invention relates to a pattern inspection apparatus and an inspection method capable of capturing an image of a copper plating pattern that has been chemically polished.

[0002]

2. Description of the Related Art Printed wiring boards, IC packages, etc.
As one of methods for forming a fine pattern (copper foil or the like) on the surface, there is a tenting method, for example. This tenting method is a method of forming a pattern by attaching a resist film to the surface of a copper foil, exposing it, and then etching it. For this reason, if the adhesiveness of the resist film is poor, the etching solution will also penetrate into the pattern portion. If this happens, pattern formation may not be performed well, and there is a risk of pattern breakage or line breakage. Therefore, it is necessary to improve the adhesion of the resist film to the copper foil surface.

Therefore, the surface of the copper foil is subjected to a jet scrub treatment to roughen the surface to enhance the adhesiveness of the resist film. This jet scrub treatment was effective on the copper foil surface, but was not so effective on the copper plated surface. That is, even if a jet scrub treatment was applied to the copper-plated surface similarly to the copper foil surface, the surface could not be roughened well. Therefore,
The copper-plated surface is roughened by chemical polishing.

Then, an appearance inspection using image processing is performed to inspect the quality of the formed pattern.
This pattern quality inspection usually utilizes the fact that the light reflectance differs between the pattern (copper foil, etc.) and the non-pattern area, and the light is radiated to the object to be inspected and the intensity of the reflected light is detected by the light receiving element. It is done by detecting. That is, the defective portion is detected by performing image processing on the information detected by the light receiving element to visually recognize the pattern and comparing it with the reference pattern.

In such an appearance inspection, a transmission light (hereinafter referred to as "rod lighting device") as an illuminating device and an illuminating device using a line type light guide (hereinafter referred to as "line type light guide illuminating device") are used. , Etc.) are commonly used. Therefore, the two lighting devices illustrated here will be briefly described.

First, the rod illuminator will be described with reference to FIG. As shown in FIG. 7, the rod lighting device includes a light source unit 101 and a rod unit 104. The light source unit 101 is provided with a halogen lamp 102 which is a light source, and a mirror 103 for condensing the light projected from the halogen lamp 102. On the other hand, the rod unit 104 is provided with a solid quartz rod 105 having a diameter of about 10 mm and an aluminum casing 106 that supports it. A reflecting film 107 is processed on one end surface of the quartz rod 105, and a white stripe 108 is applied on a part of the back surface.

In the rod illuminator having such a structure, the light projected from the light source unit 101 is used for the quartz rod 10.
When the light is made incident on the end face of No. 5, the light is totally reflected and transmitted in the quartz rod 105. At this time, the light striking the white stripe 108 applied to the quartz rod 105 is diffused.
As a result, the diffused light is emitted linearly with a certain width with directivity due to the lens action of the quartz rod 105 (FIG. 8). And, in the point that rod lighting has a moderate diffused light (having a certain width) and the illuminance distribution is uniform,
Better than other line lighting.

Next, the line type light guide lighting device will be described with reference to FIG. The line-type light guide illuminating device includes a light source (not shown) such as a halogen lamp and a light guide 110 shown in FIG. In the light guide 110, an entrance end 111 formed by bundling one end of a plurality of optical fibers and the other end of the optical fiber are arranged in a straight line for several lines so that light can be irradiated in a line, and fixed by a mold. Irradiation end 112, incidence end 111 and irradiation end 112
A cable portion 11 formed by bundling optical fibers that connect with
3 and 3.

With such a structure, in the line type light guide illuminator, the light projected from the light source is incident on the incident end 1.
When it is incident on 11, the light is transmitted to the irradiation end 112 by each optical fiber. Then, since the emission ends of the optical fibers are arranged in a straight line at the irradiation end 112, linear light is emitted.

[0010]

However, in the conventional rod illuminator, since the light striking the white stripe 108 applied to the quartz rod 105 is diffused and irradiated, the illuminance of the irradiated light is low. turn into. Moreover, since the light source is a single light, the absolute brightness is low. On the other hand, in the conventional line-type light guide illuminator, it is difficult to make the illuminance distribution uniform because the diffusion processing is not performed on the exit side and the arrangement of the optical fibers varies. Moreover, since the light source is also a single light, the absolute brightness is low.

For this reason, the conventional inspection device using the illuminating device has a problem that it is not possible to capture an image of the copper plating pattern which has been almost completely lost in gloss as a result of chemical polishing. This is because reflected light having sufficient brightness cannot be obtained from the pattern, and contrast between the base material and the pattern cannot be obtained. That is, the contrast (100
It is impossible to obtain more than gradation. In fact, when the chemically polished product was measured using a conventional illumination device, as shown in FIG. 10, the contrast between the substrate and the pattern was only about 40 gradations.

The reason why the brightness of the reflected light from the chemically-polished copper plating pattern becomes low is that the surface of the chemically-polished copper plating has fine irregularities as shown in FIG. Conceivable. That is, the irradiated light is attenuated each time it enters the concave portion and is repeatedly reflected inside the concave portion. As a result, the irradiated light is absorbed without being reflected. Therefore, in the inspection device using the conventional illumination device having a low absolute brightness, reflected light that can be imaged from the pattern could not be obtained.

Therefore, the present invention has been made in order to solve the above-mentioned problems, and it is possible to obtain reflected light having an imageable brightness even from a copper plating pattern which is chemically polished and has almost no gloss. An object is to provide a pattern inspection device and an inspection method.

[0014]

A pattern inspection apparatus according to the present invention, which has been made to solve the above-mentioned problems, has an irradiation end for irradiating an inspection surface of an object to be inspected with line-shaped light and an irradiation from the irradiation end. Having a light receiving element that receives the light reflected by the inspection surface, in a pattern inspection device that inspects the quality of the pattern on the inspection surface based on the detection information of the light receiving element, a light source that supplies light to the irradiation end, A spectral filter that cuts light having a short wavelength component whose reflectance due to the pattern is smaller than that due to the base, among the light supplied from the light source.

The term "base" used in the present specification means
It is a non-patterned portion on the inspection surface, and is a base material portion in the case of a wiring board, for example. And as the irradiation end,
A light guide in which the emitting ends of a plurality of optical fibers are arranged on a straight line for several rows may be used. Moreover, examples of the light source include a metal halide light source, a halogen light source, and an LED light source.

In this pattern inspection apparatus, light is first supplied from the light source to the irradiation end. Then, line-shaped light is irradiated from the irradiation end to the inspection surface of the inspection object.
Then, the light reflected by the inspection surface is received by the light receiving element. Here, in the light received by the light receiving element, a short wavelength component whose reflectance due to the pattern is smaller than that due to the base is cut by the spectral filter. Therefore, only the reflected light from the pattern can be selectively received by the light receiving element. As a result, a sufficient contrast is obtained between the inspection surface and the pattern. That is, even a copper-plated pattern that has been chemically polished and has almost no luster provides sufficient contrast. Therefore, even with a copper-plated pattern that has been chemically polished and has little gloss, reflected light having sufficient brightness can be obtained, and an image can be captured. If the spectral filter is on the optical path from the light source to the light receiving element,
You can place it anywhere.

Here, in the pattern inspection apparatus according to the present invention, the spectral filter preferably has a hue of yellow to orange. This is because by using such a spectral filter, reflected light having sufficient brightness can be obtained and an image can be taken even with a copper plating pattern that has been chemically polished and has almost no gloss. In particular, it is effective when the base is white.

Further, in the pattern inspection apparatus according to the present invention, the irradiation end is arranged so as to emit light at a predetermined angle with respect to the normal line of the inspection surface, and the light receiving element is irradiated from the irradiation end. It is preferably arranged so as to receive specularly reflected light with respect to light. This is because, with such a layout, the irradiation efficiency is about four times as high as when the irradiation light is vertically reflected by using a half mirror. The predetermined angle may be in the range of about 10 to 30 degrees.

Here, in the pattern inspection apparatus according to the present invention, the light source is provided with a plurality of lamps, and the irradiation end preferably randomly mixes the light supplied from the light source and irradiates the light.

By using multiple light sources in this way,
The illuminance of light emitted from the irradiation end can be increased.
On the other hand, if the number of light sources is increased, it becomes difficult to make the illuminance distribution of the light emitted from the irradiation end uniform. This is because it is difficult to make the amount of light of each lamp the same. In addition,
The cause of the difference in the light amount of each lamp is considered to be a product error of each lamp itself, a difference in the skill of an operator who adjusts the output of the lamp, and the like. Therefore, in this pattern inspection illumination device, light supplied from multiple light sources is randomly mixed at the irradiation end. Thereby, even if the light quantity of each lamp varies, the illuminance distribution of the light emitted from the irradiation end can be made uniform. That is, the illuminance can be increased while keeping the illuminance distribution of the irradiation light uniform.

In the pattern inspection apparatus according to the present invention, it is desirable that a diffusing member that diffuses the light emitted from the irradiation end is arranged between the irradiation end and the object to be inspected. In particular, the diffusing member is preferably arranged closer to the object to be inspected than the center between the irradiation end and the object to be inspected.

The pattern on the inspection surface of the object to be inspected is generally formed in a direction parallel to and intersecting with the linear light emitted from the irradiation end. Therefore, the pattern formed in the direction parallel to the linear irradiation light is
The image is slightly darker and thinner than the pattern formed in the direction intersecting the linear irradiation light. This is because the deflection angle of the light irradiated from the irradiation end is narrow with respect to the pattern formed in the direction parallel to the linear irradiation light.

Therefore, in this pattern inspection apparatus, a diffusion member is arranged between the irradiation end and the object to be inspected. This diffusing member causes variations in the deflection angle of the irradiation light, so that line-shaped light having a certain width (elongated surface illumination) is formed. When a light guide is used as the irradiation end, the intensity of light emitted from each optical fiber is not always the same, and the irradiation directions are not always the same. That is, the illuminance distribution may be non-uniform. However, since the intensity of light emitted from each optical fiber can be made uniform by using the diffusing member, the illuminance distribution of the light emitted from the irradiation end can be made more uniform.

Then, an elongated surface illumination having a uniform illuminance distribution is applied to the pattern. Therefore, the pattern formed in the direction parallel to the linear irradiation light is prevented from being captured in a dark and thin pattern. That is, the pattern formed in the direction parallel to the linear irradiation light can be imaged in the same manner as the pattern formed in the direction intersecting the linear irradiation light.

It is desirable that the diffusing member is made of glass fibers formed into a sheet and hardened with a resin. By arranging the diffusing member, the light radiated on the inspection object is attenuated. Then, the brightness of the reflected light also decreases. Therefore, it is necessary to prevent the irradiation light from being attenuated by the diffusion member. Therefore, it is decided to use a sheet made of glass fiber and solidified with a resin as the diffusing member. Thereby, the transmission efficiency of the irradiation light with respect to the diffusion member is improved. As a result, the attenuation of the irradiation light by the diffusion member is suppressed as much as possible. Therefore, even if the diffusing member is arranged, it is possible to obtain the reflected light having the brightness capable of capturing an image.

Further, in the pattern inspection apparatus according to the present invention, it is preferable to have a condenser lens for condensing the light emitted from the irradiation end. This is because the irradiation loss of the light emitted from the irradiation end can be reduced. A cylindrical lens may be used as the condenser lens. When a light guide is used as the irradiation end, the same effect can be obtained without using a condensing lens by subjecting the exit end of each optical fiber to converging processing (the tip is processed into a hemispherical shape). You can

Further, in the pattern inspection apparatus according to the present invention, the above-mentioned constituent elements are combined, that is, a light source having a plurality of lamps, an irradiation end for randomly mixing light supplied from the plurality of lamps, and a light source. By combining the spectral filter that cuts the short-wavelength component in which the brightness of the reflected light from the pattern of the light that becomes smaller than the brightness of the reflected light from the inspection surface, a diffusing member, and a condenser lens, The contrast between the inspection surface and the pattern becomes clearer. Therefore, even a copper-plated pattern that has been chemically polished and has almost no gloss can be imaged more accurately.

Further, the pattern inspection method according to the present invention is
In the pattern inspection method, in which the inspection surface of the inspection object is irradiated with light, the reflected light is detected by the light receiving element, and the quality of the pattern on the inspection surface is inspected based on the detection information, the reflectance by the pattern on the inspection surface Is characterized in that the light receiving element receives light in which a short wavelength component smaller than the reflectance due to the base is cut.

Further, in the inspection method according to the present invention, it is preferable that the specularly reflected light of the light irradiated on the inspection surface is received by the light receiving element. At this time, it is desirable to randomly mix the lights supplied from the plurality of lamps and then irradiate the inspection surface. Further, it is more desirable to collect the light to be irradiated on the inspection surface and diffuse the collected light in the vicinity of the inspection object. Even with such a method, it is possible to obtain the same effect as that of the above-described lighting device.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION The most preferred embodiment of a pattern inspection apparatus according to the present invention will be described in detail below with reference to the drawings. In the present embodiment, a case will be described where the present invention is applied to a pattern inspection device for a printed wiring board.

First, FIG. 1 shows a schematic structure of a pattern inspection apparatus to which the present invention is applied. The pattern inspection apparatus includes a line-type light guide 11 that is an irradiation end, a light source unit 12 that supplies light to the line-type light guide 11, and an optical fiber bundle 13 that connects the line-type light guide 11 and the light source unit 12.
Cylindrical lens 14, diffuser plate 15, lens 1
6, a CCD line sensor camera 18 having a one-dimensional CCD element 17, and a table 20 on which a wiring substrate 19 having a pattern formed on a white base material is placed.

The line type light guide 11 and CC
Each of the D line sensor cameras 18 has a table 2
It is arranged at an angle of 11.5 degrees with respect to the normal line H of 0. That is, the regular reflection light from the wiring board 19 due to the light emitted from the line-type light guide 11 is C
The line type light guide 11 and the CCD line sensor camera 18 are arranged so that the CD line sensor camera 18 receives the light.
And are arranged. With such an arrangement, the irradiation efficiency can be significantly improved as compared with the case where the irradiation light is vertically reflected by using the half mirror.

In this pattern inspection apparatus, the image pickup system is movable in the X-axis direction (front-back direction of the paper in FIG. 1) and the table 20 is movable in the Y-axis direction (left-right direction of the paper in FIG. 1). Has become. This allows the pattern inspection apparatus to capture an image of the entire surface of the wiring board 19.

Here, the above-mentioned line type light guide 1
1, the light source unit 12, the cylindrical lens 14, and the diffusion plate 15 constitute an irradiation device. Therefore,
This lighting device will be described in detail with reference to FIG. The light source unit 12 includes a power source 30 and three lamp units 31,
31 and 31 are provided. The power supply 30 and each lamp unit 31, 31, 31 are connected by a cable.

Each lamp unit 31 comprises a lamp 32 for supplying light to the line type light guide 11 and a color filter 33. In this embodiment, a halogen lamp is used as the lamp 32. In addition to the halogen lamp, a metal halide lamp, an LED, or the like can be used. These selections may be made in consideration of brightness and proper wavelength.

The color filter 33 includes a lamp 32.
The short wavelength component shown in FIG. Specifically, a filter having a hue of yellow to orange may be used. As a result, the wiring board 1
At 9, the short wavelength component of the irradiation light from the lamp 32 is cut so that the brightness of the reflected light from the base material becomes smaller than the brightness of the reflected light from the pattern.

Particularly, in the pattern inspection apparatus according to the present embodiment, the light source section 12 has three lamp units 31, 31,
31 is provided to increase the brightness of the irradiation light from the line-type light guide 11. Further, the base material of the wiring board 19 is white. For these reasons, the reflection level from the base material becomes high. For this reason, in the wiring board 19, it is difficult to obtain contrast between the base material and the pattern. Therefore, the reflection from the base material can be suppressed by using the color filter 33 to cut a predetermined short wavelength component of the irradiation light from the lamp 32. As a result, the contrast between the substrate and the pattern can be easily obtained.

Returning to FIG. 2, the line-type light guide 11
Can input light from the three lamp units 31, 31, 31 via the optical fiber bundles 13, 13, 13. Then, the input light is randomly mixed at the irradiation end as shown in FIG. Thereby, even if the light amount of each of the lamps 32, 32, 32 varies to some extent, the illuminance distribution in the linear light emitted from the line-type light guide 11 becomes uniform. That is, by configuring the line type light guide 11 as described above, the illuminance can be increased and the illuminance distribution can be made uniform.

Returning to FIG. 2 again, the cylindrical lens 14 attached to the tip of the line type light guide 11.
Has an elongated rectangular parallelepiped shape, and its lower portion is processed into an arc shape (see FIG. 1). The reason why the cylindrical lens 14 is attached to the tip of the line type light guide 11 is to prevent the light emitted from the line type light guide 11 from spreading too much.

Diffusion plate 1 arranged near wiring board 19
Reference numeral 5 is for diffusing the irradiation light condensed by the cylindrical lens 14, which is made by forming glass fibers into a sheet and hardening it with resin. The reason why the light condensed by the cylindrical lens 14 is diffused by the diffusion plate 15 is as follows. That is, on the wiring board 19, a pattern (hereinafter, “vertical pattern”) formed in a direction orthogonal to the linear light emitted from the line-type light guide 11 is formed.
And a pattern formed in a direction parallel to the linear light emitted from the line-type light guide 11 (hereinafter, referred to as “horizontal pattern”). Then, the light emitted from the line-type light guide 11 is condensed by the cylindrical lens 14.

From these facts, as shown in FIG. 5, the deflection angle of the irradiation light is different between the vertical pattern and the horizontal pattern.
That is, the deflection angle of the irradiation light is wide in the vertical pattern (FIG. 5A), whereas the deflection angle of the irradiation light is narrow in the horizontal pattern (FIG. 5B). Further, the cylindrical lens 14 also collects light in the direction in which the horizontal pattern is formed. Therefore, the horizontal pattern is slightly darker and thinner than the vertical pattern. When imaged in this way,
The quality of the pattern cannot be accurately inspected. Therefore, the diffusion plate 15 is provided in order to avoid a situation in which the lateral pattern is imaged finely.

By providing the diffusion plate 15,
Variations can be made in the deflection angle of the irradiation light in the direction in which the horizontal pattern is formed (see FIG. 1).
As a result, the light finally applied to the wiring board 19 becomes elongated surface illumination. Therefore, the horizontal pattern can be accurately imaged without thinning. Further, by providing the diffusing plate 15, the illuminance and the direction of the light emitted from each optical fiber arranged on the emission surface of the line-type light guide 11 can be made uniform. As a result, the wiring board 1
It is possible to make the illuminance distribution of the light with which 9 is irradiated even more uniform.

Further, the diffuser plate 15 is arranged in the vicinity of the wiring board 19 in order to irradiate the wiring board 19 with high-intensity elongated surface illumination. That is, this is to effectively utilize the light collection effect (increased illuminance) by the cylindrical lens 14. In other words, the cylindrical lens 14
This is because if the diffusion plate 15 is arranged in the vicinity of, the effect of condensing light (increased illuminance) cannot be obtained. further,
Since the diffuser plate 15 is not made of an acrylic material that is generally used but a glass-based one, the diffuser plate 1
It is possible to suppress the attenuation of light due to the passage of 5 as much as possible. This is because glass has good transmission efficiency.

Next, the inspection method in the pattern inspection apparatus configured as described above will be briefly described. First, the wiring board 19 to be inspected is set at a predetermined position on the table 20. When the wiring board 19 is installed on the table 20, the wiring board 19 is removed from the line-type light guide 11.
Light is applied to the pattern formed above. Then, in this state, the imaging system of the inspection device and the table 20 are moved to scan the entire surface of the wiring board 19. The image pickup system includes a light source unit 12 excluding a power source, a line-type light guide 11, a cylindrical lens 14,
It is composed of a diffusion plate 15, a lens 16, and a CCD line sensor camera 18.

At this time, the light reflected from the wiring board 19 is received by the one-dimensional CCD element 17. Then C
In the CD line sensor camera 18, image processing is performed based on the detection data of the one-dimensional CCD element 17. By this image processing, a binarized image of the pattern on the wiring board 19, that is, an inspection image is obtained. Then, the quality of the pattern formation is determined by comparing the obtained inspection image with the reference data.

FIG. 6 shows the result of measuring the contrast between the chemically-polished copper plating pattern and the substrate using the pattern inspection apparatus according to the present embodiment. The chemical polishing treatment was performed using CPE-900 manufactured by Mitsubishi Gas Chemical Company. As is clear from FIG. 6, there is a contrast of about 100 gradations between the base material and the pattern. That is, the contrast of the number of gradations required for capturing an image is secured. As described above, by using the pattern inspection apparatus to which the present invention is applied, even a chemically-polished copper plating pattern can be reliably imaged and the quality of the pattern can be inspected with high accuracy.

As described in detail above, the pattern inspection apparatus according to this embodiment includes three lamp units 3.
A light source unit 12 having 1, 31, 31 is provided, a line type light guide 11 for irradiating linear light, a cylindrical lens 14, and a glass type diffusion plate 15. Each of the lamp units 31 includes a lamp 32 and a color that cuts a short wavelength component of the irradiation light from the lamp 32 such that the brightness of the reflected light from the base material is smaller than the brightness of the reflected light from the pattern. And a filter 33. Thereby, the illuminance of the light emitted from the line-type light guide 11 can be increased while suppressing the reflection from the base material.

In the line type light guide 11, 3
The light input from the one lamp unit 31, 31, 31 is randomly mixed and emitted. Therefore, the illuminance distribution of the light emitted from the line-type light guide 11 is made uniform. Further, the cylindrical lens 14 reduces irradiation loss from the line-type light guide 11. Then, the diffuser plate 15 forms an elongated surface illumination. Further, since the diffusion plate 15 is made of glass, the transmission efficiency is high. Therefore, the attenuation of the irradiation light due to the passage of the diffusion plate 15 can be suppressed to the minimum.

As a result of these, in this pattern inspection apparatus, the high-intensity irradiation light in which the short-wavelength component is cut so that the brightness of the reflected light from the base material becomes smaller than the brightness of the reflected light from the pattern is wired. The substrate 19 is irradiated. As a result, even if the pattern is chemically polished to have almost no gloss, reflected light having a brightness sufficient to provide contrast with the substrate can be obtained. Therefore, it is possible to perform an accurate inspection even on a pattern that has been chemically polished and has almost no gloss.

The present embodiment is merely an example and does not limit the present invention. Therefore, the present invention naturally has various improvements within a range not departing from its gist,
Deformation is possible. For example, in the above embodiment, the color filter 33 is arranged in the lamp unit 31, but it may be arranged anywhere on the optical path from the lamp 32 to the one-dimensional CCD element 17. Also, although the one-dimensional CCD element 17 is used as the light receiving element, of course, the two-dimensional CC element is used.
A D element can also be used. Further, the line type light guide 11 and the CCD line sensor camera 18 are arranged so as to form an angle of 11.5 degrees with respect to the normal line H of the table 20, but the angle is not limited to this angle and is about 10 to 30 degrees. The same effect can be obtained by arranging within the range. Furthermore, although cases have been described with the above embodiments where the present invention is applied to a wiring board pattern inspection apparatus, the present invention is not limited to inspections of wiring boards and can be widely applied to visual inspections.

[0051]

As is apparent from the above description, according to the pattern inspection apparatus and the inspection method of the present invention, the reflected light having the brightness capable of capturing an image even from the copper-plated pattern that has been chemically polished and has little gloss Is obtained. As a result, even a copper-plated pattern that has been chemically polished and has almost no gloss can be accurately imaged.

[Brief description of drawings]

FIG. 1 is a side view showing a schematic configuration of a pattern inspection apparatus according to an embodiment.

FIG. 2 is a front view showing a schematic configuration of the lighting device in FIG.

FIG. 3 is a diagram showing spectral characteristics of reflected light from a base material and a pattern on a wiring board.

FIG. 4 is a diagram schematically showing an internal configuration of a line type light guide.

FIG. 5 is a vertical pattern without a diffuser plate (see FIG.
It is a figure for demonstrating the shape of irradiation light with respect to (a)) and a horizontal pattern (FIG.5 (b)).

FIG. 6 is a diagram showing the results of measuring the contrast between a chemically-polished copper plating pattern and a substrate.

FIG. 7 is a diagram showing a schematic configuration of a rod lighting device.

FIG. 8 is a diagram showing a shape of light emitted from the rod lighting device.

FIG. 9 is a perspective view of a light guide.

FIG. 10 shows the results of measuring the contrast between a copper plating pattern chemically polished and a substrate using a conventional lighting device.

FIG. 11 is an enlarged view in which a part of the chemically polished copper-plated surface is enlarged.

[Explanation of symbols]

11 Line type light guide 12 Light source 14 Cylindrical lens 15 Diffuser 17 One-dimensional CCD device 18 CCD line sensor camera 19 wiring board 30 power 31 lamp unit 32 lamps 33 color filters H table normal

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2F065 AA49 CC01 DD03 DD09 FF42                       GG02 GG21 JJ25 LL00 LL03                       LL08 LL21 LL49 MM03 PP12                       QQ31 SS04                 2G051 AA65 AB03 BB07 BB09 BB17                       CA03 CB01 CD07 EA11 EA12                       EB01

Claims (8)

[Claims] 1. A light receiving element for irradiating an inspection surface of an object to be inspected with linear light, and a light receiving element for receiving the light emitted from the irradiation end and reflected by the inspection surface. In a pattern inspection device that inspects the quality of a pattern on an inspection surface based on detection information, a light source that supplies light to the irradiation end, and a light source that supplies light from the light source, the reflectance by the pattern is lower than the reflectance by the base. A pattern inspection apparatus comprising: a spectral filter that cuts a small short wavelength component. 2. The pattern inspection apparatus according to claim 1, wherein the spectral filter has a hue of yellow to orange. 3. The pattern inspection apparatus according to claim 1, wherein the irradiation end is arranged so as to irradiate light at a predetermined angle with respect to a normal line of the inspection surface, and the light receiving element includes the irradiation end. A pattern inspection apparatus, which is arranged so as to receive specularly reflected light with respect to the light emitted from the device. 4. The pattern inspection apparatus according to claim 3, wherein the light source is provided with a plurality of lamps, and the irradiation end randomly mixes and irradiates the light supplied from the light source. Characteristic pattern inspection device. 5. The pattern inspection apparatus according to claim 3 or 4, wherein a diffusion member that diffuses the light emitted from the irradiation end is arranged between the irradiation end and the object to be inspected. A pattern inspection device characterized by. 6. The pattern inspection apparatus according to claim 5, wherein the diffusing member is formed by forming glass fibers into a sheet and hardening the resin with a resin. 7. The pattern inspection apparatus according to any one of claims 3 to 6, further comprising a condenser lens that condenses light emitted from the irradiation end. 8. A pattern inspection method for irradiating light on an inspection surface of an object to be inspected, detecting the reflected light by a light receiving element, and inspecting the quality of a pattern on the inspection surface based on the detection information. 2. The pattern inspection method, wherein the light receiving element receives light in which a short-wavelength component whose reflectance due to the pattern is smaller than that due to the base is cut.