JPH0743320A - X-ray inspection method and its system, and inspection method for prepreg and production of multi-layer wiring board - Google Patents

Abstract

PURPOSE:To provide an X-ray inspection method and its system by which a clear transmissive X-ray picture can be obtained from an object to be inspected. CONSTITUTION:The system is provided with an X-ray source 101, an XY positioning stage 103 which positions a mounting table for a sample to be inspected 102 by moving it in X and Y directions, an X-ray optical conversion means 108 which detects a transmissive X-ray picture transmitted from the sample by applying an X-ray emitted from the source 101 onto the sample and converts it into an optical picture, and a photoelectric conversion means 110 which receives the detected optical picture and detects it as a transmission density X-ray picture signal. Further, the system is also provided with a noise removal means for removing noise elements from the transmission density X-ray picture signal, a level conversion means which converts the transmission density X-ray picture signal with any noise removed into a signal level corresponding to the sample thickness, and a level correction means for correcting changes in the detected signal level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to transmission X from an inspection object.
Related to an X-ray inspection method and an apparatus for inspecting the inspection object from the X-ray image, particularly by irradiating the inspection object with X-rays containing many wavelengths for which the X-ray absorptance of the inspection object is large, The present invention relates to an X-ray inspection method and apparatus for obtaining a clear transmitted X-ray image and then inspecting the inspection object with high accuracy.

[0002]

2. Description of the Related Art As an X-ray generator according to the prior art,
For example, JP-A-1-204648 and JP-A-55-4
The one described in Japanese Patent No. 2640 is known. In this case, X-rays are emitted to the inspection target (subject or the like), while transmitted X-rays passing through the inspection target are detected by the X-ray detector.

[0003]

However, in the case of the above publication, it is particularly considered that the X-ray having a specific wavelength is desirably generated according to the inspection object and then the X-ray is irradiated to the inspection object. Has not become. That is, in the past, continuous X-rays were generated by bremsstrahlung by irradiation of an electron beam on a target, but the continuous X-rays were simply expressed as a spectral distribution having a certain width. It is being generated.

Generally, the X-ray absorptivity of the inspection object differs depending on the wavelength of the X-ray, and also depends on the material of the inspection object.
The X-ray absorptances for specific wavelengths of X-rays are different. In other words, in order to obtain a clear transmitted X-ray image from the inspection target, it is desirable that the X-rays irradiated on the inspection target be made of a material having a wavelength with a high X-ray absorption rate.

An object of the present invention is to provide an X-ray inspection method and an apparatus therefor capable of obtaining a clear transmitted X-ray image from an inspection object.

Another object of the present invention is to provide an X-ray inspection capable of highly reliably inspecting conductive foreign matter mixed in or adhering to the inside and the surface of an insulating sheet called a prepreg used for manufacturing a multilayer wiring board. To provide a device.

Another object of the present invention is to provide a method for inspecting a prepreg and a method for manufacturing a multi-layer wiring board for manufacturing a high-quality multi-layer wiring board that does not cause a short circuit or a state close to a short circuit between wiring patterns. .

[0008]

In order to achieve the above object, the present invention irradiates an X-ray containing at least a wavelength for which the X-ray absorptance of the inspection target is large, to the inspection target, and the inspection is performed. An X-ray inspection method is characterized in that a transmission X-ray image transmitted through an object is detected, and the inspection object is inspected based on the transmission X-ray image. Further, the present invention irradiates the inspection object with a characteristic X-ray containing two or more kinds of wavelengths having a high X-ray absorption rate in the inspection object, and detects a transmitted X-ray image transmitted through the inspection object, The X-ray inspection method is characterized by inspecting the inspection object based on the transmitted X-ray image.

The present invention also provides C in a printed circuit board.
The printed circuit board is irradiated with a characteristic X-ray having a wavelength of 0.4 nm to 1.5 nm, which has a high X-ray absorption coefficient with respect to a wiring pattern such as u or Au, and is transmitted through the printed circuit board. An X-ray inspection method comprising detecting an X-ray image and inspecting the printed circuit board based on the transmitted X-ray image. Further, the present invention uses a focused electron beam as Mo or C.
0.4 nm to 1.5 nm generated by irradiating a target made of u or Au or an alloy thereof
Is irradiated onto a printed circuit board having a wiring pattern such as Cu or Au, a transmitted X-ray image transmitted through the printed circuit board is detected, and the printed circuit is based on the transmitted X-ray image. X characterized by inspecting the board
It is a line inspection method. The present invention also provides a characteristic X including a wavelength of 0.4 nm to 1.5 nm generated from a minute region of 20 μm or less by irradiating a target made of Mo, Cu, Au, or an alloy thereof with a focused electron beam.
A transparent X which irradiates a printed circuit board having a wiring pattern such as Cr or Au with a wire and is transmitted through the printed circuit board.
An X-ray inspection method comprising detecting a line image and inspecting the printed circuit board based on the transmitted X-ray image.
Further, the present invention uses a focused electron beam as Mo, Cu, or Au.
Alternatively, a characteristic X-ray including a wavelength of 0.4 nm to 1.5 nm generated by irradiating a target made of these alloys is irradiated to the insulating member, and a transmitted X-ray image transmitted through the insulating member is detected, The X-ray inspection method is characterized by inspecting a minute conductive metal foreign substance existing on the surface or inside of the insulating member based on the transmitted X-ray image. Further, according to the present invention, by irradiating a target made of Mo, Cu, Au, or an alloy thereof with a focused electron beam, 0.4 nm to be generated from a minute region of 20 μm or less.
A characteristic X-ray including a wavelength of 1.5 nm is applied to an insulating member, a transmitted X-ray image transmitted through the insulating member is detected, and a minute amount existing on the surface or inside of the insulating member based on the transmitted X-ray image. X characterized by inspecting conductive metallic foreign matter
It is a line inspection method.

Further, according to the present invention, a stage means for mounting and positioning an inspection object and an inspection in which X-rays containing a large number of wavelengths having a large X-ray absorption rate in the inspection object are positioned by the stage means. An X-ray source for irradiating an object, an optical image conversion means for detecting a transmitted X-ray image transmitted through the inspection object and converting it into an optical image, and an optical image by the optical image conversion means into a transmitted X-ray image signal. A photoelectric conversion unit for converting, an image processing unit for inspecting the inspection target based on a transmission X-ray image signal image obtained from the photoelectric conversion unit, and a stage control unit for controlling movement of the stage unit are provided. It is a characteristic X-ray inspection apparatus. Further, the present invention is characterized in that, in the X-ray inspection apparatus, the X-ray source is an X-ray tube capable of controlling a tube voltage and a tube current. The present invention is also the X-ray inspection apparatus, wherein the X-ray tube is
It is characterized by having a target made of the same material as the inspection target. Further, the present invention is characterized in that, in the X-ray inspection apparatus, the X-ray tube includes a target made of an alloy of two or more kinds of metals.

According to the present invention, the X-ray source, an XY positioning stage for moving and positioning the mounting table on which the sample to be inspected is mounted in the X- and Y-axis directions, and the X-ray emitted from the X-ray source are described above. X-ray light converting means for irradiating the sample to be inspected positioned by the XY positioning stage to detect a transmitted X-ray image transmitted through the sample to be inspected and converting it into an optical image.
The optical image detected by the line-light conversion means is received to transmit the light and shade X
A photoelectric conversion unit that detects a line image signal, a noise removal unit that removes a noise component from a transmission grayscale X-ray image signal obtained from the photoelectric conversion unit, and a transmission grayscale X-ray image from which noise has been removed by the noise removal unit. A level converting means for converting the signal into a signal level corresponding to the thickness of the sample to be inspected, and a level for correcting fluctuations in the detection signal level of the transmission gray-scale X-ray image signal converted by the level converting means. A foreign matter mixed in the sample to be inspected and a foreign matter adhering to the surface based on the transmission gray-scale X-ray image signal corrected by the level correcting means. It is an X-ray inspection device. Further, according to the present invention, in the X-ray inspection apparatus, the X-ray source converges an electron beam or the like into a minute area and irradiates a target material with the X-ray source to generate an X-ray from the minute area. It is characterized by being configured. Further, the present invention is characterized in that the X-ray inspection apparatus further comprises an imaging magnification control means for controlling an imaging magnification of the transmitted X-ray image detected by the X-ray light converting means. According to the present invention, in the X-ray inspection apparatus, an auxiliary stage is further provided outside the protective cabin, and the mounting table is provided in the protective cabin between the auxiliary stage and the XY positioning stage to be opened and closed. It is characterized in that it is provided with a carrying means for carrying in and out through a window. Further, the present invention is the X-ray inspection apparatus, further comprising an X-ray measuring unit for measuring the intensity of X-rays emitted from the X-ray source.
A line measuring means is provided, and the level correcting means corrects the detection signal level according to the intensity of the X-ray measured by the X-ray measuring means. Further, the present invention provides the X-ray inspection apparatus, further comprising an X-ray measuring unit for measuring the intensity of X-rays emitted from the X-ray source, and an X-ray intensity measured by the X-ray measuring unit. And a control means for controlling the X-rays emitted from the X-ray source. The present invention is also the above-mentioned X-ray inspection apparatus, further comprising the transmission gray-scale X corrected by the level correction means.
It is characterized by comprising display means for displaying the line image signal. Further, the present invention provides an auxiliary stage provided outside a protective cabin, an XY positioning stage for moving and positioning a mounting table on which a sample to be inspected is mounted in the X and Y axis directions, and the mounting table described above as the auxiliary stage. And a transfer means for carrying in and out through a window provided in the protective cabin between the XY positioning stage and the XY positioning stage, and an electron beam or the like is converged on a minute area to irradiate the target material. An X-ray source configured to generate X-rays from a very small area, and the X-rays emitted from the X-ray source are irradiated to the inspected sample positioned by the XY positioning stage to And a photosensing unit for obtaining an X-ray transmission image by sensitizing the transmitted X-ray image on a film, and inspecting the foreign substance mixed in the sample to be inspected and the foreign substance adhering to the surface by the photosensitive unit. An X-ray examination apparatus, characterized in that the sea urchin configuration.

Further, according to the present invention, the prepreg is irradiated with X-rays, and it is inspected based on the transmitted X-ray gray-scale image whether or not the conductive foreign matter defined inside and on the surface of the prepreg is mixed or attached. This is a method for inspecting a prepreg, which is characterized in that

Further, according to the present invention, the prepreg is irradiated with X-rays, and it is inspected based on the transmitted X-ray gray-scale image whether or not the conductive foreign matter defined inside and on the surface of the prepreg is mixed or attached. A prepreg in which conductive foreign substances specified on the inside and on the surface are not mixed or attached, and the prepared prepreg and a wiring board having a wiring pattern formed on an insulating material are laminated and heated to form a multilayer wiring board. Is a method of manufacturing a multilayer wiring board.

[0014]

When the inspection object is inspected with X-rays, when the inspection object is irradiated with X-rays containing a large number of wavelengths for which the material of the inspection object has a large X-ray absorption rate. In addition, it is possible to obtain a clear transmitted X-ray image from the inspection object, and as a result, it is possible to inspect the inspection object with high accuracy by performing image processing after detecting the transmission X-ray image. .

On the other hand, in a multilayer wiring board or the like used for manufacturing an electric circuit, a cloth-like sheet obtained by weaving glass fibers into a mesh shape is impregnated with an insulating material such as polyimide. A wiring pattern substrate on which a wiring pattern (circuit pattern) is formed of the conductive material is prepared, and a large number of the wiring pattern substrates are stacked via an insulating sheet called the prepreg. However, if a conductive metallic foreign substance is mixed or adhered to the inside and the surface of the insulating sheet, the wiring pattern becomes a short circuit or a state close to a short circuit, and it is necessary to inspect this to eliminate defects. . In this way, the target conductive metal foreign matter is to ensure long-term reliability after manufacturing the multilayer wiring board,
Even if it is several tens of μm or less, it is necessary to detect this and prevent the deterioration of the insulation characteristics due to the migration of the wiring pattern such as copper. Therefore, in the present invention, an insulating sheet called a prepreg is made of a material having a relatively low molecular weight, and has a high X-ray transmittance, while a metal that is a problem as a conductive foreign metal is Fe, Mo, W or the like. , And the relatively low X-ray transmissivity, it is possible to obtain a high reliability based on an X-ray transmission image of minute conductive metal foreign substances that are mixed or adhered inside and on the surface of an insulating sheet called a prepreg. Since it is possible to inspect each minute, the minute conductive metal foreign matter is present only within the specified value on the inside and the surface of the insulating sheet, and the wiring pattern substrate is insulated from the minute conductive metal foreign matter. When a multi-layer wiring board is manufactured by stacking a large number of sheets while interposing sheets, it is possible to secure the reliability of the insulation characteristics for a long time as the multi-layer wiring board.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS.

First, the X-ray inspection apparatus according to the present invention will be described. FIG. 1 shows a schematic structure of an example thereof. In this case, in the present example, it is assumed that the inspection target 6 has a circuit pattern 6a formed on the surface thereof, for example, a printed wiring board, and the X-ray tube 1 is attached to the inspection target 6.
X-rays are emitted from above. In this case, the X-ray tube 1 uses a target 3 made of a material capable of generating a characteristic X-ray having a wavelength with a large X-ray absorption rate in the circuit pattern 6a, and the target 3 has a value not less than a value determined by the material of the target 3. By irradiating the target 3 with the electron beam 4 having the tube voltage, the target 3 generates X-rays having a wavelength peculiar to the material, that is, characteristic X-rays. The inspection object 6 is irradiated. The intensity of the characteristic X-ray is several times as high as that of the continuous X-ray, and the width of the wavelength distribution is very narrow. At that time, the tube voltage and the tube current in the X-ray tube 1 are the same as those in the cabin 21. It is optimally set by an external X-ray generation controller 26. The tube voltage and the tube current are optimal so that the tube voltage value is maintained at a value equal to or higher than the value for generating the characteristic X-ray from the target 3 and the characteristic X-ray having the intensity suitable for the detection of the tube current value is generated. When set to, specific X-rays can be generated from the X-ray tube 1 with desired intensity.

As described above, the specific X-ray generated by the X-ray tube 1 is applied to the inspection object 6, as shown in FIG.
Shows a printed wiring board as the inspection object 6. As shown in the figure, the printed wiring board 9 is formed by forming various circuit patterns 11 on the surface of the base material 10. The circuit pattern 11 is generally made of metal, and the base material 10 is also formed. Most of them are constructed as organic materials. Here, assuming that the materials of the circuit pattern 11 (6a) and the base material 10 are copper and organic material, respectively, and returning to FIG. 1 again and continuing the description, the characteristic X-rays from the X-ray tube 1 are printed wiring board 9 The circuit pattern 11 absorbs part of the characteristic X-rays and the rest is transmitted through the circuit pattern 11, while the base material 10 has a characteristic X-ray transmittance of copper. Therefore, most of the characteristic X-rays applied to the base material 10 are directly transmitted through the base material 10. In this way, the X-rays are transmitted from the printed wiring board 9, and the transmitted X-rays 7 are converted into an optical image by the image intensifier 8 and further the lens 16 and the mirror 1 are provided.
The image is detected as an image by the camera 20 through the lens 8, the lens 17, and the shutter 19, and the detected image is subjected to predetermined image processing by the image processing device 27, so that various defects on the circuit pattern 11 (short circuit, disconnection, etc.). The presence or absence of is checked. In the image intensifier 8, the image portion corresponding to the circuit pattern 11 is dark, and
Assuming that the image portion corresponding to the base material portion 10 is bright,
An optical image is obtained from the transmitted X-ray 7. In this example, the printed wiring board 9 as the inspection target 6 is
Is positioned and placed on the X stage 22 and the Y stage 23, and is moved in the X and Y directions as desired.
The device itself is moved in the Z direction 24 as desired by a Z stage (not shown). However, in addition to fixing the 24 position in the Z direction of the X-ray tube 1 itself, the inspection target 6 is used instead.
May be moved in the Z direction by the Z stage. The XYZ stage controller 25 is provided to control the movement of the X, Y, and Z stages.

Here, the X-ray absorptivity of copper Cu, which is the material of the circuit pattern 11, will be described. The X-ray absorptivity varies depending on the wavelength of the irradiation X-ray.
FIG. 3 shows the mass attenuation coefficient with respect to the irradiation X-ray wavelength of copper Cu. However, the characteristic X-ray having a wavelength at which a large mass attenuation coefficient is obtained, that is, a wavelength having a large X-ray absorption rate is generated. By using the obtained material as the target 3, the image for the circuit pattern 11 can be detected more clearly. As is well known, the mechanism of generation of characteristic X-rays is that the inner shell electron of an atom, for example, the electron of the K shell becomes vacant, and when the shell electron drops from the outer shell (L shell etc.) to that vacancy, X-rays are generated by using the energy difference of 2 as energy. By the way, the wavelength of the characteristic X-ray in the K series of copper Cu is about 0.16 μm. This is because the wavelength of the characteristic X-ray is at the absorption edge, that is, when a large X-ray absorption rate is obtained. It is also the X-ray wavelength. In other words, the peak of the X-ray absorptivity of copper Cu appears at the wavelength of about 0.16 μm, and the X-ray absorptance decreases as the wavelength becomes shorter. Incidentally, the wavelength of the characteristic X-rays for metals other than copper Cu, for example, the wavelength of the characteristic X-rays in the K series of tungsten W is about 0.02 μm, and molybdenum M
The wavelength of the characteristic X-ray in the K series of o is about 0.07 μm.

Now, in FIG. 4, the tube voltage of the X-ray tube is 60 kV.
The wavelength-X-ray generation intensity characteristics are shown for molybdenum Mo and tungsten W when set to 1. From this, it can be seen that when the material of the circuit pattern 11 is copper Cu, the target 3 As for tungsten W, its characteristic X
The wire does not exist in the range where the X-ray absorption rate of copper Cu is large, whereas when molybdenum Mo is used, copper C
It can be seen that characteristic X-rays having a wavelength having a large X-ray absorption rate in u can be generated. In other words, when the material of the circuit pattern 11 is copper Cu, the target 3 made of molybdenum Mo is used rather than the target 3 made of tungsten W so that the image for the circuit pattern 11 is more This is desirable for detecting as a clear one. Here, the case where molybdenum Mo is used for the target 3 will be described in detail. The tube voltage at that time is K
It has to be set to 28 kV or more, which is a value for generating the characteristic X-ray in the series. Further, neither the tube current required to generate an X-ray having an intensity suitable for image detection, that is, the image intensifier 8 used for detecting a transmitted X-ray, has a sufficient light amount or an excessive light amount. The tube current required to obtain a transmitted X-ray having an appropriate intensity is required to be optimally set. Specifically, for example, the tube voltage is set to 60 kV, the tube current is set to 20 mA, and the wavelength is about 0.07 μ.
The characteristic X-ray of m should be generated. The tube voltage and the tube current set as described above may be reset to optimum values each time the conditions of the inspection target 6, the stage, etc. change. In particular, the tube current value can be optimally updated and set by feedback control based on the image detection signal level or the transmission X-ray detection signal level from a transmission X-ray detection sensor that is separately provided.

The outline of the present invention has been described above. By the way, in the above example, the material of the circuit pattern 11 is copper C.
In the case of u, molybdenum Mo was used for the target 3, but the wavelength of the X-ray for the large absorptivity of copper Cu is also the wavelength at the absorption edge of copper Cu, which is the characteristic X-ray of copper Cu. Equal to the wavelength. Therefore, copper C is added to the target 3.
When the printed wiring board 9 is irradiated with the X-rays 5 including the characteristic X-rays of copper Cu in addition to u, the amount of X-rays absorbed by the copper Cu increases, resulting in the image intensifier 8
In the optical image obtained from the above, the image portion corresponding to the circuit pattern 11 is obtained as a darker image and is more clearly obtained. By inspecting a clear image of the circuit pattern 11, finer defects on the circuit pattern 11 can be detected. Further, in the above example, copper Cu is assumed as the material of the circuit pattern 11, but when gold Au is used as the material of 11 like the wiring in the LSI package, the target is targeted. If gold is used for 3, the same effect as when the material of the circuit pattern 11 is copper is obtained. Further, in the above example, the inspection target is the circuit pattern 11 exclusively,
It is also possible to detect a metal as a foreign matter contained in the base material 10. Since the foreign metal particles have a higher X-ray absorptivity than the base material 10, a large amount of X in the foreign metal particles to be detected is detected.
Base material 1 is X-ray 5 including characteristic X-ray of wavelength with respect to linear absorption rate.
When 0 is irradiated, the metallic foreign matter can be detected as a dark image portion. Furthermore, in the above examples, the target 3 was composed of one kind of metal, but in some cases, the target 3 may be an alloy or mixture of two or more kinds of metals. For example, when copper Cu and molybdenum Mo are used as the material of the circuit pattern 11, a clear X-ray transmission image can be selected by using an alloy of molybdenum Mo and copper Cu for the target 3. The inspection target 6 may be, for example, a soldered portion of an electronic circuit component other than the printed wiring board 9.

By the way, in the above example, the X-ray 5 from the X-ray tube 1 was directly radiated to the inspection object 6 as it is.
As shown in FIG. 5, the X-rays 5 from the X-ray tube 1 are filtered by the filter 1
The inspection target 6 is irradiated with X-rays through the filter 2 as filter-transmitted X-rays 13. The X-ray having the wavelength corresponding to the small X-ray absorptivity of the inspection target 6 corresponds to the X-ray having the wavelength corresponding to the large X-ray absorptivity of the filter 12, and therefore, the inspection target 6 is the Since X-rays with a wavelength corresponding to a large X-ray absorption rate of are mainly irradiated,
A clearer X-ray transmission image can be obtained.

In the above example, the inspection object support base 14 represented by an XYZ stage or the like is not particularly considered, but the inspection object 6 is supported by the inspection object support base 14 as shown in FIG. In this state, when the X-ray 5 from the X-ray tube 1 is applied to the inspection target 6, the inspection target 6 and the inspection target support transmitted X-rays 15 from the inspection target support 14 are the image intensifier 8 However, in consideration of the X-ray absorptance of the whole other than the inspection object 6 such as the inspection object support base 14 and the like, the optimum wavelength X
When irradiating with a ray, a clearer transmitted X-ray image can be obtained.

Next, another embodiment of the present invention will be described with reference to the drawings.

FIG. 7 is a block diagram showing the arrangement of a foreign matter inspection apparatus according to an embodiment of the present invention. Here, a conductive F that is mixed or attached to the inside and the surface of an insulating sheet called a prepreg used for a multilayer wiring board is present.
A case of inspecting a metal such as e, Mo, W or the like for a minute foreign substance having a size of several tens of μm or less will be described.

In FIG. 7, 101 is an X-ray source that can be regarded as a point source that focuses an electron beam or the like on a minute area and irradiates a target material to generate X-rays, 102 is an inspected sample such as an insulating sheet, and 103. X holds the sample 102 to be inspected and is moved and positioned in at least the X and Y axis directions.
Y positioning stage mechanism, 104 is a motor for driving the XY positioning stage mechanism 103, 115 is the X-ray source 101
A motor for driving the Z stage for moving the
Reference numeral 105 denotes a stage control means for measuring displacement (coordinates) by a displacement measuring device and controlling movement of the XY positioning stage mechanism 103 and the Z stage at arbitrary timing.
06 is a stage control signal, 107 is coordinate data measured by a displacement measuring device, 108 is an X-ray optical converter such as an image intensifier, 109 is a detection optical system, 110 is a photoelectric converter such as a television camera, and 111 is Signal processing circuit, 1
12 is an inspection result, 113 is a protective cabin, 116 is the X-ray control data 117, and controls the X-ray source 101 based on the X-ray irradiation intensity from the X-ray source measured by the X-ray measuring device 118, and performs signal processing. It is an X-ray control means for correcting the light amount variation in the circuit 111.

The X-ray control means 116 shown in FIG.
The voltage and the current applied to the radiation source 101 are adjusted, and X is transferred only when the X-ray protection window 114 described later is closed after the sample 102 such as the insulating sheet is conveyed into the protection cabin 113. X-ray source 101 for irradiating X-rays
To control. Further, the applied voltage and current to the X-ray source 101 are adjusted by the X-ray dose control data 117 so that the X-rays irradiated on the sample 102 to be inspected are optimized.
At this time, if the X-ray dose measuring device 118 is installed in the vicinity of the X-ray optical converter 108 and the current is adjusted so that the X-ray dose detected by the X-ray dose measuring device 118 becomes a predetermined value, the inspection target The X-ray irradiated on the sample 102 has a desired value, a constant X-ray transmission image is obtained from the sample to be inspected, and stable inspection can be performed.

The motor 115 shown in FIG.
By moving the Z stage equipped with the radiation source 101 in the Z-axis direction, the magnification determined by the distance between the X-ray source and the sample to be inspected and the distance between the X-ray source and the X-ray optical converter can be arbitrarily changed. You can Thereby, for example, the magnification can be changed according to the sample 102 to be inspected, or after completion of the inspection, the magnification can be visually confirmed on the monitor 120 based on the X-ray transmission image signal obtained from the photoelectric converter 110. Further, the X-ray light converter 108 can usually change the magnification of the input surface and the output surface of the X-ray light converter 108 by changing the condensing condition of the internal electron lens.
The optimum detection magnification can be set in combination with the movement of 1 in the Z-axis direction. In FIG. 7, the motor 115 moves the X-ray source 101 in the Z-axis direction, but the ratio of the distance between the X-ray source and the sample to be inspected and the distance between the X-ray source and the X-ray optical converter is a magnification. Since it is specified, the position of the sample 102 to be inspected in the Z-axis direction, or the X-ray optical converter 108, not the X-ray source 101.
It goes without saying that the magnification may be changed by the position in the Z-axis direction and the composite movement thereof.

FIG. 8 shows the XY positioning stage mechanism 1 described above.
An example of No. 03 is shown. XY positioning stage mechanism 10
Numeral 3 designates a sample mount through an XY stage 201 which is provided in the protective cabin 113 and moves in the XY axis directions, a sample mount 202 on which the sample 102 to be inspected is mounted, and an X-ray protection window 114 which is opened and closed from outside the protective cabin 113. Conveyor belt 2 that guides 202 by a conveyance guide 205 to carry in / out.
06, the sample mounting table 20 loaded by the transport belt 206
Positioning pin 2 for positioning 2 on the XY stage 201
03, 204, an auxiliary stage 207 provided outside the protective cabin 113 for placing the sample placing table 202, a transport guide 205 provided on the auxiliary stage 207 for guiding the sample placing table 202, and provided on the auxiliary stage 207. It is composed of a transport belt 206 for loading / unloading the sample mounting table 202 into / from the protective cabin 113 through the X-ray protection window 114 which is opened and closed. X-ray defense window 114
It is a window provided with a protective cabin 113 and having a movable plate that shields X-rays. FIG. 9 shows an embodiment showing the structure of the sample mounting table 202. In FIG. 9, the sample mounting base 202 is a frame 3 having a groove in which the holding plate 303 is placed.
02, the holding plate 303, a guide pin 304 for positioning by engaging with a reference hole or a reference surface formed in the sample 102 to be inspected, and positioning pins 203 and 204 installed on the XY stage 201, and mounting the sample The table 202 is formed of positioning holes 305 for positioning. Sample mounting table 20
2 moves between the XY stage 201 and the auxiliary stage 207 along the conveyance guide 205 by the conveyance belt 206 through the opened / closed X-ray protection window 114. The sample 102 to be inspected is positioned by the guide pins 304 on the auxiliary stage 207 and mounted on the holding plate 303, and the transport belt 205 and the sample mounting base 202 together with the XY stage 20.
1 and is positioned on the XY stage 201 by the positioning holes 305 provided on the frame 302 of the sample mounting table 202 and the positioning pins 203 and 204 provided on the XY stage 201. Here, the positioning pins 204 are movable, and the sample mounting table 202 is moved up to a predetermined position after the completion of loading on the XY stage 201 to position the sample mounting table 202. When the sample mounting base 202 is carried out from the XY stage 201, the positioning pin 204 is removed so as to descend and retract.

By dividing the frame 302 and the holding plate 303, it is possible to select and use a material having a low X-ray transmittance for the holding plate 303 and a material having a high rigidity for the frame 302. The optimum stage for inspection can be configured. Further, according to this configuration, positioning of the stage (sample mounting table) 202 and the like are performed by the frame 302.
The holding plate 3 which is likely to affect the inspection results
It is possible to easily recover the scratches, damages, etc. of 03 by replacing only the holding plate 303, and it is possible to make maintenance extremely easy. Further, when there are a plurality of types of inspected samples 102,
Optimal holding plate 303 depending on the material of the sample 102 to be inspected
Can be selected and exchanged.

Here, it goes without saying that the holding plate 303 is not necessary when the rigidity of the sample 102 to be inspected is high. It is possible to reduce unnecessary attenuation of.

By providing the auxiliary stage 207 so that the sample 102 to be inspected can be set outside the protective cabin 113, the operability is improved and the X-ray protection window 11 is provided at the time of inspection.
By closing 4 and irradiating X-rays, X that is harmful to the human body
It is easy to protect workers from lines.

The sample 102 to be inspected is a protective cabin 113.
And is positioned on the sample mounting base 202 by being positioned by the guide pin 304 outside. The sample 102 to be inspected is shown in FIG.
The example of is illustrated. FIG. 10A is an example in which a guide hole 401 for positioning is provided in the sample 102 to be inspected, and FIG. 10B is an example in which no guide hole is provided. In the example of FIG. 10A, since the guide hole 401 is used as a consistent reference position throughout the manufacturing process, it is possible to consistently and accurately manage the coordinates of the foreign matter detected by the X-ray transmission image, and other For example, it is possible to unify the defect coordinate management and the repair process integrated with the wiring pattern inspection result after the wiring pattern is formed. In addition, FIG.
In the example of (b), the pretreatment for making the guide hole is unnecessary.

In each example, the sample 102 to be inspected
May inspect one or more simultaneously. The inspection time can be shortened in the inspection of a plurality of sheets.

As shown in FIG. 11 (a), a protective bag 501 is provided with one or more prepreg samples 102 to be inspected.
It is also possible to inspect it while putting it in etc. In this case,
There is an effect that it is possible to remove the influence of adhered foreign matter in transportation, storage work, etc. after the test sample 102 is created. In addition, FIG.
As shown in (b), it is possible to provide a sample box 502 and inspect for powder or liquid. In FIG. 11 (b),
An example in which the guide hole 504 is provided is shown in FIG. 10B.
It is also possible to use the outer wall of the sample box 502 for positioning, as in the example shown in FIG. According to the example shown in FIG. 11B, it is possible to inspect a powder or a liquid with accurate coordinates. Of course, the sample box 502 may have any structure as long as it can hold the sample 102 to be inspected. The lid 503 may be provided or not provided, and may be properly used depending on the sample 102 to be inspected.
The sample 102 to be inspected may be a so-called copper-clad laminate in which a conductive material 506 such as homogeneous copper is added to the surface of an insulating material 505 as shown in FIG. 11C used for manufacturing a wiring pattern. Alternatively, as shown in FIG. 11D, the sample 102 to be inspected may be a material wound in a roll.

As shown in FIG. 7, the sample 102 to be inspected set in the protective cabin 113 is irradiated with X-rays, and the X-ray transmission image thereof is converted into an optical gray-scale image by the X-ray light converter 108. . The optical grayscale image is appropriately converted in magnification by the detection optical system 109, converted into an electric signal by the photoelectric conversion element 110, and then, by the signal processing circuit 111, the sample 102 to be inspected from the change in the electric signal. Detects minute foreign particles of conductive metal inside and on the surface. At this time, the coordinate detected from the stage control unit 105 is referred to, and the detected coordinate of the conductive metallic fine foreign matter is managed. If an X-ray source that generates cone-beam-shaped X-rays is used, the X-ray transmission image of the sample 102 to be inspected obtained by the X-ray optical converter 108 is the X-ray source-inspected sample distance and X-ray. Since the magnification is expanded to the magnification determined by the distance between the X-ray light converter and the X-ray light converter, it is possible to perform an inspection independent of the coordinate resolution of the X-ray light converter 108 and thereafter. Further, the X-ray source 101 ideally has a projected image on the pattern to be inspected by the radiation source, but an electron beam or the like, which is smaller than the minimum detected defect size, is most preferably 10 μm or less. If the method is such that the target material is irradiated with the light by converging it in a minute area (preferably 20 μm or less), the size of the radiation source can be regarded as a point, and FIG. As shown in FIG. 12B, a signal with less deformation such as 601 deterioration of a detection signal generated at the edge portion of a fine metal foreign substance of several tens of μm or less of metal such as Fe, Mo, W is obtained. That is, it is possible to detect metallic fine foreign matters existing in the prepreg with high sensitivity by a signal with little deterioration. That is, when the X-ray detection signal of the minute foreign matter cannot be made into a point by the radiation source, the contrast determined by the ratio between the brightness of the background level and the detection level of the foreign matter deteriorates due to the deterioration of 601. Is impossible under the predetermined conditions.

FIG. 13 shows a concrete example of the signal processing circuit 111. The motor 104 shown in FIG.
The positioning stage mechanism 103 is moved stepwise or continuously, and at this time, as shown in FIG. 13, the stage control signal 106 can be generated based on the design information 701. The design information 701 describes, for example, wiring information of a wiring (circuit) pattern substrate, and includes information indicating which part of the inspected sample 102 is actually effective as a circuit. Therefore,
By moving the stage based on the design information 701 so as to scan only a portion that is truly a problem in manufacturing a product, it is possible to shorten the inspection time and improve the product yield. Further, the design information 701 includes size and thickness information of the inspected sample 102 such as a prepreg,
It is used for designating the inspection area or setting the imaging magnification.

As shown in an example in FIG.
If 02 is composed of a wiring pattern forming area 801 and a non-wiring pattern forming area 802, the coordinate values that define these areas are in the design information 701, and based on this, the prepreg and other objects are covered. It is sufficient to move the XY stage 201 so as to inspect only the wiring pattern formation region (it is obvious that the wiring pattern may be divided) with respect to the inspection sample 102.

A specific embodiment of the signal processing circuit 111 will be described with reference to FIG. The electric signal obtained by the photoelectric converter 110 according to the X-ray transmittance of the sample 102 to be inspected is a noise removal circuit 7 configured by an image frame integration, an average value filter, a median filter, or the like.
After the signal quality is improved by 04, the level converter 705 converts the signal level, and the light amount fluctuation correction circuit 706 corrects the level fluctuation in a short cycle of about the photoelectric conversion storage time. Next, the shading correction circuit 707 corrects the shading generated in the X-ray light converter 108, the detection optical system 109, and the like. The correction data 709 is reference data for shading correction that is preset before the start of inspection. The determination circuit 708 detects the metallic micro foreign matter based on the signal corrected by the circuit. At this time, the inspection output 710 is generated by simultaneously referring to the coordinate data 703 obtained from the coordinate management and signal control circuit 702. In this way, the coordinate data of the metallic microscopic foreign matter can be displayed on the monitor (display) 120.

FIG. 15 shows a specific embodiment of the light quantity variation correction circuit 706. The signal v (x) input from the level converter 705 is input and stored in the frame memory 906 and the peak detection circuit 902, and the maximum value in the detected frame is stored. When the scanning of one frame is completed, the output Vp of the peak detection circuit 902
Is V0 set to the reference level 901 and the comparator 903.
As a result, a gain G904 (0 <G <x, x is an arbitrary numerical value) is given to the amplifier 905 as a gain with respect to the reference value. Next, the detection signal v (x) temporarily stored in the frame memory 906 is sent to the amplifier 905.
Is converted into a signal v ′ (x) having an appropriate amplitude level and sent to the shading correction circuit 707 at the next stage.

FIG. 16A shows a light amount variation correction circuit 706.
An example of the input signal v (x) of is shown. In FIG. 16, v
(x) is an input signal whose level is reduced as a whole, v '(x) is a normal state input signal (correction target value), and x is a coordinate value. It is considered that the fluctuation of v ′ (x) occurs due to a change in the generation efficiency of the X-ray due to the disturbance of the electron beam when the X-ray is generated. Assuming that the input signal is v (x) and its peak value is Vp, a reference level V0 given in advance is given.
The gain G is given by, for example, the following equation (Equation 1).

G = V0 / Vp (Equation 1) Therefore, the signal v '(x) after the light amount variation correction is obtained by the following equation (Equation 2).

V ′ (x) = G × v (x) (Equation 2) A judgment circuit 708 is used to extract a pattern in the inspection of a circuit pattern and a metallic foreign substance of an insulating member such as a prepreg.
In the above, signal processing such as binarization processing is performed on the detection signal. However, according to the present embodiment, there is an unavoidable fluctuation in the detection signal level as shown in FIG. 16A when using X-rays. Since the correction can be performed and the signal processing such as the binarization processing can be made constant under a predetermined condition, the inspection can be stabilized.

Further, the gain G does not depend on the peak signal Vp obtained from the detection signal v (x), but instead, for example, another X-ray detection sensor provided near the X-ray optical converter 108, for example, an X-ray measuring instrument. Obviously, it may be based on the X-ray intensity measured from 118. That is, as an example,
The measurement result of the X-ray dose by the X-ray measuring device 118 shown in FIG. 7 can also be used. At this time, an appropriate delay circuit is used for the X
It goes without saying that the detection signals are synchronized between the line measuring device 118 and the amplifier 905. According to this embodiment, since the gain G is controlled based on the peak detection Vp, it is possible to reduce an error due to noise at the time of peak detection.

Here, in general, the detection signal level A by X-ray should decrease in proportion to the material and thickness index of the sample to be inspected (object to be inspected) 102 based on the following equation (Equation 3). It has been known. In the level converter 705, for example,
The signal is logarithmically converted according to the following equation (Equation 4), and the signal level is corrected so as to be proportional to the thickness t of the sample 102 to be inspected. According to the present embodiment, the sample to be inspected (object to be inspected)
There is an effect that the sensitivity does not vary depending on the thickness t of the.
Further, by preparing a plurality of logarithmic transformation bases (log α) and switching them, the sensitivity to the thickness t of the sample to be inspected can be changed.

A = A3exp (−μt) (Equation 3) logαA = logαA3 + logα (−μt) = logαA3 + (loge (−μt)) / (logeα) = logαA3 + (− μt) / (logeα) (Formula 4) A3 is the intensity of X-rays irradiated on the sample to be inspected, μ is a constant determined by the material of the sample to be inspected, and t is the thickness of the sample to be inspected.

The level converter 705 may be composed of, for example, a lookup table or the like. In this case, not only logarithmic conversion but also arbitrary conversion is possible. Therefore,
For example, a change in the sensitivity characteristic of the system, which occurs when the X-ray optical converter 108 is replaced, can be absorbed by changing the look-up table. In the case of the present embodiment, maintenance of the device and adjustment when manufacturing a plurality of devices can be easily performed.

The shading correction circuit 707 corrects a change in the detection signal level in the detection visual field, which is generated by the X-ray light converter 108, the detection optical system 109 and the like. Reference data is required for correction, and a specific embodiment for realizing the data will be described here. As shown in FIG. 9, a plurality of reference samples 3 having different thicknesses serving as the reference of the detection level or a plurality of reference samples 3 according to the type of the sample to be inspected
01 is installed. For example, the plurality of reference samples 30
For example, the same material as that of the sample 102 to be inspected may be set as a reference for the light level, and a material having a lower X-ray transmittance than that of the sample 102 to be inspected may be set as the reference value of the dark level.
Further, a plurality of reference samples 301 may be provided depending on the thickness of the sample to be inspected. As shown in FIG. 17B, it is assumed that the bright level Vw (x) and the dark level Vb (x) are obtained. Here, x is a coordinate. In the shading correction circuit 707, for example, the following calculation is performed for each pixel, that is, for each x coordinate, and FIG.
A correction signal v ″ (x) shown in the following equation (5) is obtained as shown in FIG.

V ″ (x) = (v ′ (x) −vb (x)) × V0 / (vw (x) −vb (x)) (Equation 5) According to the present embodiment, the operating time of the device Even if the sensitivity of each component fluctuates with the passage of time, it is possible to always correct this.The reference sample 301 may be only one kind or a plurality of pieces may be installed. hand,
The effect is that the optimum correction is possible.

Next, an embodiment of the judgment circuit 708 will be shown.
The X-ray transmission image of the inspected sample 102 is
It is given as shown in FIG. The inspected sample 102 corresponding to FIG. 16C is shown in FIG. The transmitted image signal level of the inspected sample 102 is high, and the transmitted signal level of the conductive metallic microscopic foreign matter 100 to be detected is low. Therefore, the detection signal v ″ (x) is binarized with an appropriate threshold value Vth,
The defect output 710 may be obtained by detecting a detection level lower than Vth, that is, a dark portion of the detection signal.

The defect output 710 may be detected by using an operator as shown in FIG. FIG. 17
(A) shows an example of an operator in the x-axis direction. Reference pixels t1, t2, and t3 are provided, and t1 and t2, and t2 and t
The distance between 3 is a. As shown in FIG. 17B, the condition of the following equation (Equation 6) is satisfied with k as an arbitrary determination value in the foreign matter portion, and therefore the foreign matter can be detected by detecting this.

| T1-t2 |> k, and | t2-t3 |> k (Equation 6) Here, the number of the reference pixels and the determination values are not limited to those in the above-described embodiment, and a plurality of them may be used as necessary. May be provided. Also, a plurality of operators having different a may be prepared. For example, as shown in FIG. 17C, by using five reference pixels t1 to t5, an output corresponding to the size of the foreign matter can be obtained from the output of each operator. At this time, if an identifier indicating the detected operator type is added to the defect output 710, the detection result can be classified and output according to the type of foreign matter. As shown in FIG. 13, if coordinate data 703 obtained from the coordinate management and signal control circuit 702 is referred to and added to the inspection output, confirmation and removal work after the inspection can be easily performed. The data to be added to the inspection output may be the coordinate data 703 itself, or may be the coordinate value obtained by correcting the coordinate data 703 with the coordinate data within the detection field of view clearly obtained by the determination circuit 708. According to the latter, it is possible to accurately detect the detected foreign matter during confirmation and removal work.

As described above, X by the point X-ray with respect to the sample 102 to be inspected detected from the photoelectric converter 110.
The noise removal circuit 704 removes noise from the line-transmission image signal, and the level conversion circuit 705 performs logarithmic conversion to obtain an X-ray transmission image signal approximately proportional to the thickness of the sample to be inspected. The light amount fluctuation correction circuit 706 and the shading correction circuit 707 correct the fluctuations in the inspection region and the fluctuations due to the test sample due to the test sample exchange, so that conductive metal fine foreign matters mixed in the test sample such as a prepreg are removed. From the inspection output 710, the inspection result 112 of the conductive metallic fine foreign matter adhering to the surface of the sample to be inspected
Can be inspected with high reliability.

The inspection output 710 is not only output to the outside as the inspection result 112, but can be reused in this apparatus. As shown in FIG. 13, based on the inspection output 710, the coordinate management and signal control circuit 702 again
If the XY stage 201 is moved to the coordinates where the conductive metal fine foreign matter is present, the visual reconfirmation by the X-ray can be easily performed on the monitor 120. At this time, by using the coordinate values obtained by correcting the coordinate data 703 with the coordinate data in the detection field of view, for example, even a foreign matter detected in the peripheral portion of the screen is displayed in the center of the screen, or a detection site is indicated by a circle or an arrow. For example, if a pointed display is superimposed on the detected image, the inspected sample (inspected object) 1
The foreign substance can be easily identified while capturing the entire image of 02.

As shown in FIG. 18, the foreign substance detection image signal changes depending on the position of the foreign substance in the X-ray irradiation direction. Now, assuming that the distance between the X-ray source 101 and the X-ray photodetector 108 is constant, the distance z between the X-ray source 101 and the inspected sample 102 is as shown in FIGS. 18 (a) and 18 (b). ,
If the images are different, such as Za and Zb, the images obtained by the X-ray optical converter 108 have the magnitude x of xa, x as indicated by va, vb in the detection signals 1201, 1202 in FIG.
It is observed differently as shown by b, respectively, or the size w of the rising portion of the waveform is observed differently as shown by wa and wb. Therefore, when the size of the foreign material 100 to be inspected (object to be inspected) is known in advance, the distance z, that is, Za, Zb in FIG. 18 can be determined by measuring the size of x. I can know. Here, if the distance Z0 between the X-ray source 101 and the stage 201 on which the sample 102 to be inspected is mounted is constant, the X of the detected foreign substance 100 can be calculated from z and Z0.
The position in the line irradiation direction can be specified. Similarly, the position of the detected foreign substance in the X-ray irradiation direction can be specified from the value of w.

According to this embodiment, the position of the detected foreign matter 100 in the X-ray irradiation direction can be specified. Alternatively, the size of the foreign matter 100 can be estimated from the position and the thickness t of the sample to be inspected.

When the sample 102 to be inspected is a multilayer wiring board or the like, a specific pattern such as an identification number or an alignment mark, which is usually provided for each layer, can be used together. That is, the specific pattern for each layer is measured, the length w0 of the rising portion thereof is measured, and the layer in which the foreign matter 100 exists may be determined from the value of w of the detected foreign matter while referring to this value. According to this embodiment, it is possible to specify the layer in which the foreign matter exists even if the position of the stage in the X-ray irradiation direction is unknown.

By adding a detection optical system other than the X-ray to the embodiment shown in FIG. 7, it is possible to recognize the site where the conductive metallic fine foreign matter is present. An example of this
FIG. 19 shows only the relevant portions of FIG. 7 in addition. Figure 1
In FIG. 9, 1301 and 1302 are TV cameras,
The photoelectric converter 110 is linked with the photoelectric converter 110.
The same field of view as is to be detected. Reference numeral 1303 denotes a determination circuit such as a binarization circuit, which is used for the TV cameras 1301 and 1
An image of the foreign matter is extracted from 302. The delay circuit 1304 is for synchronizing the inspection output 701 and the detection signal. The output of the determination circuit 708 is 13 in the OR circuit 130.
It is ORed with the foreign matter detected by 01 or the foreign matter detected by 1302. As a result, output A1307, output B
1308 and an output C1309 are obtained. If the output A is present, it can be determined that the surface A is present, if the output B is present, the surface B is present, and when the output C is present, it is possible to determine that there is a foreign substance inside the sample 102 to be inspected. According to the present embodiment, it is possible to perform a stable inspection without generating false reports that may occur in a foreign substance inspection using only a TV camera, and to inspect the inside of the sample 102 to be inspected. This has the effect of identifying the site where the is present.

20 and 21 show another embodiment of the present invention. In FIG. 20, an X-ray source 101 and a sample 10 to be inspected
21, the film 1401, and the XY positioning stage mechanism 1501, the motor 1502, the stage control circuit 1503, the detection optical system 1504, the photoelectric converter 1505, the signal processing circuit 1506, and the light source 1507 in FIG. In FIG. 20, the sample 102 to be inspected has its transmission image picked up on the film 1401 by X-rays. After this film 1401 is developed, it is mounted on the positioning stage mechanism 1501 of FIG. 21, is transilluminated by the light source 1507, and the developed optical image is formed on the film 1401 by the detection optical system 1504, and the image is formed. Optical image to photoelectric converter 150
In step 5, the signal is converted into an image signal, and the signal processing circuit 1506 extracts metallic fine foreign matter. The stage control 1503, the signal processing circuit 1506 and the like are almost the same as those in FIG. 13 already described. Note that the film 1401 may be any one that is sensitive to X-rays, such as an imaging plate, and the transmission illumination optical system has been described with reference to FIG. 21, but other suitable film, imaging plate, or other detection medium may be used. Of course, an illumination system, for example, an epi-illumination optical system may be used. The magnification of the detection optical system 1504 may be set appropriately so that the target foreign matter can be detected. According to the present embodiment, since imaging of a film or the like can be performed in a short time, it is possible to improve the operating rate of an expensive X-ray device and reduce the inspection cost.

Further, a second stage and a detection system interlocking with the XY positioning stage mechanism 1501 of FIG. 21 are provided in the X-ray apparatus shown in FIG. 20 as shown in FIG. 7, and the sample 102 to be inspected is mounted on the second stage. Since the sample 102 to be inspected can be moved in association with the inspection by mounting, the foreign substance can be confirmed by X-rays in the actual sample 102 to be inspected when a foreign substance is detected.

Even if the X-ray source 101 in the embodiment of the present invention shown in FIGS. 7 and 20 is a general bremsstrahlung type, the X-ray is generated by converging an electron beam or the like into a minute area. Of course, it may also be one that utilizes synchrotron radiation.

Generally, when X-rays are used, blurring w as shown in FIG. 22 occurs as described with reference to FIG. 12, which is caused by the size s of the X-ray source 101, the X-ray source-coverage. Inspection sample distance ya, X-ray source-X-ray optical converter distance yb, and 15
It is determined by the heights yda, ydb, etc. of the foreign substances shown by 1, 152. In particular, when the distance between the X-ray source and the sample is large with respect to s, a case as shown in FIG. 22B occurs in which the region x having a sufficient concentration change for detection cannot be obtained. Therefore, the determination circuit 708 shown in FIG.
An image processing circuit as shown by 3 can be added to improve the signal quality. In FIG. 23, the input signal 160
1 is input to the secondary differentiation circuit 1602. At this time, the signal waveform corresponding to FIG.
The signal waveform corresponding to FIG.
The waveforms before and after the process 2 are shown. Feature extraction circuit 1603
Then, an operator 16 composed of reference pixels of t1, t2, and t3 arranged at a distance a as shown in 1603.
14 and the following equations (Equation 7), where k1 and k2 are arbitrary constants
When the expression (7) is satisfied, the true control signal 1604 of "1" is output, and when the expression (7) is not satisfied, the control signal 1604 of "0" is output.

T1 <k1 and t2> k2 and t3 <k1 (Equation 7) The shape of the operator, the values of k1 and k2, etc. may be determined from the detection signals measured in advance. The input signal 1601 is
On the other hand, after being synchronized by the delay circuit 1609, for example, the switch 16 controlled by the control signal 1604.
07, 1608 (switched to the lower side when "1",
When it is "0", it is switched to the upper side. ), And the level is changed by the signal converters 1605 and 1606 configured by a look-up table or the like. The input / output characteristics of the signal converters 1605 and 1606 are shown in FIG.
If it is as described in 1605 and 1606 of
The signal waveform indicated by 1612 is 1613 like 1613.
The signal waveform shown by is converted like 1611 and output 16
At 15, it is delivered as an improved signal waveform. According to this embodiment, it is possible to stably detect a signal from a minute foreign matter that is difficult to detect, and improve inspection accuracy.

In FIG. 7, when an image intensifier (hereinafter abbreviated as II) or the like is used as the X-ray optical converter 108, it is usually I.I. I. Since the input surface of 1 has a spherical shape, pincushion distortion occurs in the detected image. Specific examples of the present invention for reducing such distortion will be described below.

As is well known, when a plano-convex lens is arranged with a convex surface on the object side and a flat surface on the image surface side, barrel distortion occurs. Therefore, an optical system such as a plano-convex lens having barrel distortion for correcting the pincushion distortion can be added to the detection optical system 109 of FIG. 7 to cancel the pincushion distortion. In addition, I. I. Converts an X-ray into an electron on the input surface, converges the electron by an electromagnetic electron lens, and performs electron-to-light conversion on the output surface. Therefore, the electron lens may be configured to have barrel distortion. Alternatively, I. I. The input section may be provided with a mechanism for generating magnetism that causes barrel distortion in the electron lens, and the pincushion distortion may be canceled.

As another embodiment, the photoelectric converter 1 shown in FIG.
By configuring the pixel array of 10 according to the pincushion distortion, the pincushion distortion can be removed. Figure 2
4, the photoelectric converter 1801 is a CCD sensor or the like. Usually, the pixel array has a square lattice shape, but as shown in a pixel 1803 in the enlarged view 1802, the peripheral pixel is made larger than the central pixel. If the reading speed of each pixel is constant, the photoelectric converter 1 of FIG.
801 has barrel distortion. Therefore,
If the pixel 1803 is configured to cancel the pincushion distortion, an image without distortion can be obtained as a result.

When the photoelectric converter 110 of FIG. 7 is an image pickup tube or the like, the pincushion distortion can be removed by non-linearly scanning the image pickup tube. FIG. 25A shows a normal scanning method. The horizontal axis of the figure represents time, and the vertical axis represents the scanning voltage applied to the image pickup tube. Depending on the magnitude of the voltage, photoelectric conversion is performed on an arbitrary place within the surface of the image pickup tube. Figure 25
The upper part of (a) shows the scanning in the horizontal direction, and the lower part shows the scanning in the vertical direction. Generally, since a square lattice photoelectric conversion is performed, a sawtooth waveform in which the voltage changes linearly with respect to time t is shown. It is used. When this is changed to use a sawtooth voltage which is changed so that the time derivative of the voltage becomes large in the peripheral portion of the image as shown in FIG. 25B, the imaged image has barrel distortion. Will be things. Therefore, if the waveform of FIG. 25B is set so as to cancel the pincushion distortion and photoelectric conversion is performed by the image pickup tube using this, an image without distortion can be obtained as a result.

As another means for removing the pincushion distortion, as shown in FIG.
It is also possible to inspect along a part having a phase as shown in 001 and deform its shape so as to cancel the pincushion distortion. Alternatively, the signal processing circuit 111 of FIG. 13 may perform image coordinate conversion and level conversion by image processing so as to remove the pincushion distortion.

Here, in the case of a device using an electromagnetic electron lens such as the X-ray optical converter 108, the detected image is deformed under the influence of an external magnetic field or the like. In general, devices often use an iron frame to increase the rigidity of the frame, but the iron frame is easily magnetized,
There is a problem that the detected image is deformed under the influence of this magnetism. Therefore, if the X-ray optical converter is shielded with a material having a high magnetic permeability such as permalloy, the influence can be removed. On the input surface of the detector, for example, by installing a cylindrical high-permeability component like the shield portion 2101 of FIG. 27, it is possible to remove the influence of the external magnetic field flowing from the input surface.

Further, by changing the magnification of the electron lens, X
In the case where the magnification of the linear light converter 108 can be changed,
The input surface stop 2102 shown in FIG. 27, which is made of a material having a low X-ray transmittance, may be provided to remove unnecessary X-ray input. This is because when the magnification is increased, that is, when a part of the input surface of the X-ray optical converter is projected onto the entire output surface, unnecessary electrons due to the X-rays input to the outside of the effective input surface are X-rays. This is because it reflects inside the light converter 108, reaches the output surface of the X-ray light converter 108, and acts like stray light in optics. According to the present embodiment, there is an effect that the deterioration of the detected image due to the magnetic field outside the X-ray light converter 108 and unnecessary electrons in the X-ray light converter can be removed, and accurate detection can be performed.
In principle, a mechanism for absorbing the unwanted electrons may be provided in the X-ray optical converter 108 instead of the input surface stop 2102.

In the above embodiment, the inspection of the insulating sheet 221 called prepreg used for the multilayer wiring substrate 220 manufactured as shown in FIG. 28 has been described as an example.
For inspection of multi-layer boards, ceramic circuit boards, display devices such as liquid crystal, etc.
Needless to say, it is possible to inspect in the same manner for glass fibers, powders, liquids, etc., which are materials, and it is possible to inspect all appropriate objects in view of the inspection principle.

After inspection with the apparatus according to the present invention,
When a product such as a circuit board is manufactured, defects can be removed or corrected during the manufacturing process, so that the yield of the product can be improved and the cost can be reduced.

By the way, the multilayer wiring board 220 is shown in FIG.
It is manufactured as shown in. That is, the resist 235 is applied to the insulating material 231 on which the wiring material 234 is formed, a predetermined wiring pattern is exposed and developed, and then the resist is removed by etching the substrate 222 having the wiring pattern. Is manufactured. Further, a predetermined resist pattern 235 is formed on the insulating material 231 by exposure or printing, a wiring pattern 232 is formed on the resist pattern 235 by plating, and then the resist 235 is removed to form a substrate 222 having a wiring pattern. Manufactured. With respect to the insulating sheet such as the substrate 222 and the prepreg on which the wiring pattern thus formed is formed, it is inspected by the X-ray inspection apparatus described above as to whether or not the conductive metal fine foreign matter is present on the surface and inside. There is prepared a conductive metal fine foreign substance which does not exist above a specified value. The thus-prepared substrate 222 and the insulating sheet 221 are stacked and heated / pressurized to manufacture a multilayer wiring substrate. After that, through holes 224 are formed if necessary, and the inside is plated to connect the layers. A product is manufactured by mounting electronic components and the like on the surface of the multilayer wiring board.

As described above, the multilayer wiring board or the like used in the production of electric circuits is manufactured by impregnating a cloth-like sheet made of glass fibers in a mesh shape with an insulating material such as polyimide. A wiring pattern substrate 222 having a wiring pattern (circuit pattern) formed of a conductive material such as is prepared, and a large number of the wiring pattern substrates 222 are stacked via the insulating sheet 221 called the prepreg. However, if a conductive metallic foreign substance is mixed or adhered to the inside and the surface of the insulating sheet 221, the wiring pattern 232 becomes a short circuit or a state close to a short circuit, and it is necessary to inspect this to eliminate defects. Becomes In this way, the target conductive metal foreign substance is after manufacturing the multilayer wiring board,
In order to secure the reliability for a long period of time, it is necessary to detect this even if it is several tens of μm or less and prevent the deterioration of the insulation characteristics due to the migration of the wiring pattern such as copper. Therefore, in the present invention, the insulating sheet 221 called a prepreg is made of a material having a relatively low molecular weight and has a high X-ray transmittance, while the metal which becomes a problem as a conductive foreign metal is F
Focusing on the fact that the molecular weight of e, Mo, W, etc. is large and the X-ray transmissivity is relatively low, X is used to remove minute conductive metallic foreign substances that are mixed or adhered inside and on the surface of an insulating sheet called a prepreg. Since the inspection can be performed with high reliability based on the line transmission image, the minute conductive metal foreign matter is present only inside the insulating sheet 221 below the specified value, and the wiring pattern substrate 222 is When a multi-layer wiring board is manufactured by stacking a large number of sheets while interposing the insulating sheets 221 in which minute conductive metal foreign matters do not exist, it is possible to secure the reliability of the insulation characteristics for a long time as the multi-layer wiring board.

At the manufacturing site, it is often necessary to manage the occurrence of a specific foreign matter to ensure the quality of the product and identify the occurrence of defects in the manufacturing apparatus at an early stage. For example, in the manufacturing process of the multilayer wiring board, the metallic foreign matter causes a pattern short circuit, so that it must be controlled.
Therefore, as shown in FIG. 29, the adhesive sheet 251 is appropriately arranged and installed in each part of the manufacturing process in the room 260, and this is periodically inspected by the inspection device. Appropriate measures can be taken, such as repairing or improving the device A if there is a large amount of foreign substances from the adhesive sheet in the vicinity of the device A256 according to the foreign substance condition of each adhesive sheet. Alternatively, if the dust collecting mat 252 installed near the door 253 of the entrance / exit in a clean room or the like is inspected by the apparatus of this embodiment, it is possible to easily grasp the foreign matter status in the clean room, the type of foreign matter present, etc. You can manage the site accurately. In this embodiment, the same effect can be obtained with the air filter 254, the liquid filter 255, and the like. According to this embodiment, there is an effect that a stable and highly reliable manufacturing system can be supplied.

[0076]

According to the present invention, a clear transmitted X-ray image can be obtained from an object to be inspected. As a result, for example, assuming a printed wiring board as the object to be inspected, it corresponds to a circuit pattern portion. By inspecting a clear image, finer defects (such as insufficient thickness and excess) existing on the circuit pattern can be detected, as represented by disconnection, etc., and the printed wiring board can be detected. As a result, it is possible to improve the reliability.

Further, according to the present invention, minute conductive metallic foreign matters existing inside or adhering to the inside and the surface of an insulating sheet or the like called a prepreg used for a multilayer wiring board or the like are detected based on an X-ray transmission image. Since the inspection can be performed with reliability, the effect that the reliability of the insulation characteristics can be ensured for a long time as a multilayer wiring board is obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an example of an X-ray inspection apparatus according to the present invention.

FIG. 2 is a diagram showing a printed wiring board as an inspection target.

FIG. 3 is a diagram showing a mass attenuation coefficient with respect to an irradiation X-ray wavelength of copper.

FIG. 4 is a diagram showing wavelength-X-ray generation intensity characteristics of molybdenum Mo and tungsten W when the tube voltage of the X-ray tube is set to 60 kV.

FIG. 5 is a diagram showing a principle configuration of an X-ray inspection apparatus in the case of irradiating an inspection object after extracting only X-rays of a specific wavelength by a filter.

FIG. 6 is a diagram showing a principle configuration of an X-ray inspection apparatus in the case of irradiating an inspection target with X-rays in consideration of an inspection target support base and the like.

FIG. 7 is a block diagram showing a configuration of an X-ray inspection apparatus according to an embodiment of the present invention.

FIG. 8 is a diagram showing a structure of a stage according to an embodiment of the present invention.

FIG. 9 is a diagram for explaining a holding mechanism for a sample to be inspected according to an embodiment of the present invention.

FIG. 10 is a diagram for explaining a positioning mechanism according to an embodiment of the present invention.

FIG. 11 is a diagram for explaining a sample to be inspected.

FIG. 12 is a diagram for explaining the occurrence of blur when X-rays are used.

FIG. 13 is a block diagram showing a configuration of a signal processing circuit according to an embodiment of the present invention.

FIG. 14 is a diagram for explaining an inspection area according to an embodiment of the present invention.

FIG. 15 is a block diagram showing a configuration of a light amount variation correction circuit according to an embodiment of the present invention.

FIG. 16 is a diagram for explaining the function of the signal processing circuit according to the embodiment of the present invention.

FIG. 17 is a diagram for explaining the function of the determination circuit according to the embodiment of the present invention.

FIG. 18 is a diagram for explaining determination processing according to an embodiment of the present invention.

FIG. 19 is a diagram for explaining an example in which a second detection system other than X-rays is added.

FIG. 20 is a diagram for explaining an X-ray apparatus according to another embodiment of the present invention.

21 is a diagram for explaining a detection device used together with the X-ray device in FIG. 20.

FIG. 22 is a diagram for explaining a detection signal when X-rays are used.

FIG. 23 is a diagram for explaining a signal processing method according to an embodiment of the present invention.

FIG. 24 is a diagram for explaining a photoelectric converter according to an embodiment of the present invention.

FIG. 25 is a diagram for explaining a driving method of a photoelectric converter according to an embodiment of the present invention.

FIG. 26 is a diagram for explaining a method for holding a sample to be inspected according to an example of the present invention.

FIG. 27 is a diagram for explaining an image improving method according to an embodiment of the present invention.

FIG. 28 is a diagram showing a method for manufacturing a multilayer wiring board according to the present invention.

FIG. 29 is a diagram showing a manufacturing system according to the present invention.

[Explanation of symbols]

1 ... X-ray tube, 3 ... Target, 4 ... Electron beam, 5 ... X-ray,
6 ... Inspected object, 6a ... Circuit pattern, 7 ... Transmission X-ray, 8
… Image intensifier, 12… Filter, 13
... filter transmitted X-ray, 14 ... inspection target support, 15 ... inspection target support transmission X-ray, 16, 17 ... lens, 18 ... mirror, 19 ... shutter, 20 ... camera, 21 ... cabin, 22 ... X stage, 23 ... Y stage, 25 ... XY
Z stage control device, 26 ... X-ray generation control device, 27 ...
Image processing apparatus, 101 ... X-ray source, 102 ... Inspected sample,
103 ... XY positioning stage mechanism, 104 ... Motor,
105 ... Stage control, 106 ... Stage control signal, 1
07 ... Coordinate data, 108 ... X-ray light converter, 109 ... Detection optical system, 110 ... Photoelectric converter, 111 ... Signal processing circuit, 112 ... Inspection result, 113 ... Protective cabin, 114
... X-ray protection window, 115 ... Motor, 116 ... X-ray control unit,
117 ... X dose control data, 118 ... X dose measuring device, 1
20 ... Monitor, 201 ... XY stage, 202 ... Sample mounting base, 203, 204 ... Positioning pin, 205 ... Conveying guide, 206 ... Conveying belt, 303 ... Holding plate, 702 ...
Coordinate management and signal control circuit, 703 ... Coordinate data, 70
4 ... Noise removal circuit, 705 ... Level conversion circuit, 706
... light intensity fluctuation correction circuit, 707 ... shading correction circuit, 708 ... determination circuit, 709 ... correction data, 710 ...
Inspection output

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koichi Karazaki 1 Horiyamashita, Hadano-shi, Kanagawa Hitachi, Ltd. General-purpose computer division (72) Inventor Tadashi Iida 1 Horiyamashita, Hadano-shi, Kanagawa Hitate Manufacturing Co., Ltd. General-purpose computer division

Claims (34)

[Claims] 1. An inspection object is irradiated with a characteristic X-ray containing at least a wavelength having a large X-ray absorption coefficient in the inspection object, and a transmitted X-ray image transmitted through the inspection object is detected to detect the transmitted X-ray. X characterized by inspecting the inspection object based on a line image
Line inspection method. 2. An object to be inspected is irradiated with a characteristic X-ray containing two or more kinds of wavelengths for which an X-ray absorptance in the object to be inspected is large,
An X-ray inspection method comprising detecting a transmission X-ray image transmitted through the inspection target and inspecting the inspection target based on the transmission X-ray image. 3. An X-ray absorptivity of 0.4 for a wiring pattern such as Cu or Au on a printed circuit board.
The printed circuit board is irradiated with a characteristic X-ray including a wavelength of nm to 1.5 nm, a transmitted X-ray image transmitted through the printed circuit board is detected, and the printed circuit board is inspected based on the transmitted X-ray image. An X-ray inspection method characterized in that 4. A characteristic X-ray including a wavelength of 0.4 nm to 1.5 nm generated by irradiating a target made of Mo, Cu, Au, or an alloy thereof with a focused electron beam is used for wiring of Cr, Au, or the like. An X-ray inspection method comprising irradiating a printed circuit board having a pattern, detecting a transmitted X-ray image transmitted through the printed circuit board, and inspecting the printed circuit board based on the transmitted X-ray image. 5. 0.4 nm generated from a minute region of 20 μm or less by irradiating a target made of Mo, Cu, Au or an alloy thereof with a focused electron beam.
Characteristic X-rays containing a wavelength of ˜1.5 nm are converted to Cr or Au.
An X-ray inspection characterized by irradiating a printed circuit board having a wiring pattern such as the above, detecting a transmitted X-ray image transmitted through the printed circuit board, and inspecting the printed circuit board based on the transmitted X-ray image. Method. 6. An insulating member is irradiated with a characteristic X-ray containing a wavelength of 0.4 nm to 1.5 nm generated by irradiating a target made of Mo, Cu, Au, or an alloy thereof with a focused electron beam. An X-ray inspection method comprising detecting a transmitted X-ray image transmitted through the insulating member, and inspecting a minute conductive metallic foreign substance existing on the surface or inside of the insulating member based on the transmitted X-ray image. 7. 0.4 nm generated from a minute region of 20 μm or less by irradiating a target made of Mo, Cu, Au or an alloy thereof with a focused electron beam.
The insulating member is irradiated with a characteristic X-ray containing a wavelength of ˜1.5 nm, a transmitted X-ray image transmitted through the insulating member is detected, and the present X-ray image exists on the surface or inside of the insulating member based on the transmitted X-ray image. X characterized by inspecting minute conductive metal foreign matter
Line inspection method. 8. A stage means for mounting and positioning an inspection object, and irradiating the inspection object positioned by the stage means with X-rays containing many wavelengths for which the X-ray absorptance of the inspection object is large. X-ray source, an optical image conversion means for detecting a transmitted X-ray image transmitted through the inspection object and converting it into an optical image, and a photoelectric device for converting an optical image by the optical image conversion means into a transmitted X-ray image signal. It is characterized by comprising: a conversion means, an image processing means for inspecting the inspection object based on a transmission X-ray image signal image obtained from the photoelectric conversion means, and a stage control means for controlling the movement of the stage means. X-ray inspection device. 9. The X-ray inspection apparatus according to claim 8, wherein the X-ray source is an X-ray tube whose tube voltage and tube current are controllable. 10. The X-ray tube according to claim 9, wherein the X-ray tube includes a target made of the same material as the inspection target.
Line inspection equipment. 11. The X-ray inspection apparatus according to claim 9, wherein the X-ray tube includes a target made of an alloy of two or more kinds of metals. 12. An X-ray source, an XY positioning stage for moving and positioning a mounting base for mounting a sample to be inspected in X and Y axis directions, and X-rays emitted from the X-ray source for the X-ray.
X-ray light converting means for irradiating the sample to be inspected positioned by the Y positioning stage, detecting a transmitted X-ray image transmitted through the sample to be inspected, and converting it into an optical image, and detected by the X-ray light converting means. A photoelectric conversion unit that receives the received optical image and detects it as a transmission grayscale X-ray image signal, a noise removal unit that removes a noise component from the transmission grayscale X-ray image signal obtained from the photoelectric conversion unit, and the noise removal unit. Level conversion means for converting the transmission gray-scale X-ray image signal from which noise is removed into a signal level corresponding to the thickness of the sample to be inspected, and the transmission gray-scale X-ray image signal converted by the level conversion means. And a level correction means for correcting the fluctuation of the detection signal level, and based on the transmission gray-scale X-ray image signal corrected by the level correction means, the foreign matter mixed in the sample to be inspected and the foreign matter adhering to the surface are detected. X-ray inspection apparatus characterized by being configured to inspect. 13. The X-ray source is configured so that an electron beam or the like is converged on a minute region and the target material is irradiated with the X-ray to generate X-rays from the minute region. The X-ray inspection apparatus according to claim 12. 14. An X-ray inspection apparatus according to claim 12, further comprising an imaging magnification control means for controlling an imaging magnification of a transmitted X-ray image detected by said X-ray light converting means. . 15. An auxiliary stage is further provided outside the protective cabin, and the mounting table is carried in and out through a window provided in the protective cabin and opened and closed between the auxiliary stage and the XY positioning stage. 13. The X-ray inspection apparatus according to claim 12, further comprising a conveying unit. 16. An X-ray measuring means for measuring the intensity of X-rays emitted from said X-ray source is further provided, and said level correcting means is provided according to the intensity of X-rays measured by said X-ray measuring means. The X-ray inspection apparatus according to claim 12, wherein the X-ray inspection apparatus is configured to correct the detection signal level. 17. X-ray measuring means for measuring the intensity of X-rays emitted from said X-ray source, and the X-ray source emitting said radiation according to the intensity of the X-rays measured by said X-ray measuring means. Control means for controlling the X-rays according to claim 1.
The X-ray inspection apparatus described in 2. 18. The X-ray inspection apparatus according to claim 12, further comprising display means for displaying the transmission gray-scale X-ray image signal corrected by the level correcting means. 19. A second detection means other than one or a plurality of X-rays is used together, and the second detection means is based on the detection coordinates by the X-rays.
The part in which the detected foreign substance is present is identified by referring to the detection result of the detecting means of claim 1.
The X-ray inspection apparatus described in 2. 20. The photoelectric conversion means comprises a detection optical system and a photoelectric converter, and the detection optical system is configured to correct the distortion generated in the X-ray light conversion means. Item 12. The X-ray inspection apparatus according to item 12. 21. An X-ray inspection apparatus according to claim 20, wherein the X-ray inspection apparatus is configured to provide a read scanning signal of the photoelectric converter so as to correct the distortion generated in the X-ray light converting means. 22. The photoelectric conversion device according to claim 12, wherein the pixel size is sequentially increased toward the peripheral part with respect to the pixel size in the central part of the detection visual field.
The X-ray inspection apparatus described. 23. By providing a plurality of level correction means and providing a mechanism for switching between them, or by providing a mechanism capable of rewriting the correction value of the level correction means, the X
13. The X-ray inspection apparatus according to claim 12, wherein variations in detection sensitivity due to a change in the sensitivity characteristics of the line-light conversion means and the type of sample to be inspected are corrected to a predetermined reference characteristic. 24. A signal processing circuit for detecting a degree of change of a detected signal change in a transmission X-ray image is provided, and a portion where a foreign substance exists is identified from the degree of change.
The X-ray inspection apparatus described. 25. A second processing means according to claim 21, further comprising a signal processing circuit for detecting the degree of change of the detection signal change in the transmitted X-ray image, classifying the type of foreign matter based on the degree of change. 13. The X-ray inspection apparatus according to claim 12, wherein the type of foreign matter is classified and output together with the detection results corresponding to the coordinate positions obtained by. 26. An auxiliary stage provided outside the protective cabin, and an XY positioning stage for moving and positioning a mounting table on which a sample to be inspected is mounted in the X and Y axis directions.
Conveying means for loading and unloading the mounting table through a window provided in the protective cabin and opened and closed between the auxiliary stage and the XY positioning stage, and an electronic beam etc. are converged on a minute area. An X-ray source configured to irradiate a target material with X-rays to generate X-rays from a minute area, and X-rays emitted from the X-ray source to an inspected sample positioned by the XY positioning stage. A transparent X-ray image that has passed through the sample to be inspected and is exposed to light to obtain an X-ray transmission image, and the foreign matter and the surface mixed in the sample to be inspected by the photosensitive unit. An X-ray inspection apparatus characterized in that it is configured to inspect foreign matter adhering to the. 27. The prepreg is irradiated with X-rays, and it is inspected on the basis of a transmission X-ray gray-scale image whether or not conductive foreign substances defined in the inside and the surface of the prepreg are mixed or attached. Inspection method for prepreg. 28. The prepreg is irradiated with X-rays, and based on a transmission X-ray gray-scale image, it is inspected whether or not conductive foreign matter defined on the inside and the surface of the prepreg is mixed or attached. Prepare a prepreg that does not have mixed or adhered conductive foreign substances specified on the surface,
A method for manufacturing a multilayer wiring board, comprising: stacking and heating the prepared prepreg and a wiring board having a wiring pattern formed on an insulating material to manufacture a multilayer wiring board. 29. Based on the design information of the wiring board in contact with an arbitrary prepreg, only the portion where the wiring pattern exists on the wiring board is extracted, and only the relevant portion of the prepreg or the wiring board is inspected for defects. 29. The method for manufacturing a multilayer wiring board according to claim 28, characterized in that the multilayer wiring board is manufactured by removing it. 30. An X-ray sample mounting base for mounting an X-ray sample, which supports only a holding portion for a sample to be inspected, which is made of a material having a low transmittance for X-rays, and a peripheral portion of the holding portion. An X-ray sample mounting base comprising a frame portion that supports the holding portion so as not to interfere with detection. 31. An X-ray sample according to claim 30, wherein the sample to be inspected is formed into a convex shape so as to correct the pincushion distortion generated in the X-ray light converting means. Mounting base. 32. A standard sample having a known X-ray transmission amount is prepared in advance, and the reference value of the detection signal level is determined by detecting the X-ray transmission amount of the standard sample before the inspection of the sample to be inspected. Then, based on the reference value, the level correction means corrects the detection signal level, or
X emitted from the X-ray source by the control means for controlling the X-ray
An X-ray inspection apparatus characterized by controlling X-rays. 33. In an XY positioning stage for positioning an X-ray sample in the XY axis directions, a passage for passing X-rays is provided in the frame portion, and the X-ray transmission amount is previously clarified on the passage. A standard sample is installed, a reference value of the detection signal level is obtained by detecting the X-ray transmission amount of the standard sample before the inspection of the sample to be inspected, and the level correction means detects the reference value based on the reference value. An XY positioning stage, which is capable of correcting a signal level or controlling an X-ray emitted from an X-ray source by a control means for controlling the X-ray. 34. A system for managing a dust generation state by appropriately disposing a dust collecting filter, an adhesive sheet or the like, and inspecting the dust collecting filter, the adhesive sheet or the like using X-rays.