JPH0413915A - Apparatus and method for fluoroscopy - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Table of contents] Overview Industrial field of application Prior art (Fig. 15) Problem to be solved by the invention (Fig. 16) Means for solving the problem (Figs. 1 and 2) Figure) Working example (i) Explanation of the first example (3rd to 8th) (ii)
Description of the second embodiment (Figures 9 and 10) (iii)
Explanation of the third embodiment (FIG. 11) (iv) Explanation of the fourth embodiment (FIGS. 12 to 14) Effects of the invention [Summary] Regarding a device that inspects the internal state of an electrically conductive hole (hereinafter referred to as a via hole) using a thickness image generated based on fluorescence from an optical fiber plate, it is determined based on the emission spectrum of one type of fluorescent material sealed in the optical fiber plate. The purpose is to improve the X-ray detection range by using the emission spectra of various types of fluorescent materials without depending on the X-ray detection range, and to obtain high-resolution thickness images, and the first device is:
an X-ray irradiation means for irradiating the object to be inspected with X-rays; a first moving means for moving the object to be inspected; an X-ray detection means for detecting the X-rays that have passed through the object to be inspected; A second moving means for moving the detection means, and an X-ray fluoroscopic image generation means for creating a fluoroscopic image of the object to be inspected based on the detection signal from the X-ray detection means, and the X-ray detection means , an optical fiber plate encapsulating two or more fluorescent materials having different X-ray absorption characteristics, an optical filter provided in the fluorescence generating part of the optical fiber plate, and a light detection means for detecting the light passing through the optical filter. the second device is the first device,
The X-ray detection means includes an optical fiber plate in which two or more fluorescent materials having different X-ray absorption characteristics are enclosed, a first optical filter provided on one of the fluorescence generating parts of the optical fiber plate, and the optical fiber. a second optical filter provided on the other side of the fluorescence generating section of the plate; Second
The first one detects the light that has passed through the optical filter. the third device comprises a second light detection means; A second device, the X
The fourth device includes a stack of two or more optical fiber plates encapsulating two or more fluorescent materials with different radiation absorption characteristics, and the fourth device includes a plurality of optical fiber plates that irradiate the object to be inspected with two or more X-rays. an X-ray irradiation means, a first moving means for moving the object to be inspected, and two or more X-rays that have passed through the object to be inspected;
an X-ray detection means for detecting X-rays, a second moving means for moving the X-ray detection means, and an a fluoroscopic image generating means, and a plurality of X-ray filters are provided between the X-ray irradiation means and the object to be inspected,
The X-ray detection means comprises an optical fiber plate in which two or more fluorescent materials having different X-ray absorption characteristics are enclosed, a plurality of optical filters provided in the fluorescence generating part of the optical fiber plate, and light passing through the optical filters. The optical fiber plate is composed of a plurality of light detection means for detecting the light, and includes two or more of the optical fiber plates stacked one on top of the other.

[Industrial application field]

The present invention relates to an X-ray fluoroscopic inspection device and an X-ray fluoroscopic inspection method, and more specifically, the present invention relates to an X-ray fluoroscopic inspection apparatus and an X-ray fluoroscopic inspection method. The present invention relates to an apparatus for inspecting thickness images.

BACKGROUND ART In recent years, with the demand for higher functionality and performance of electronic computers and the like, there has been a demand for improved reliability of electronic components.

Accordingly, there is a need for an apparatus and method that can widely and efficiently inspect thickness images of via holes in multilayer wiring boards and the like on which various electronic components are mounted.

[Conventional technology]

FIGS. 15 and 16 are explanatory diagrams related to the conventional example.

FIG. 15 is a configuration diagram of a conventional X-ray fluoroscopic inspection apparatus, which the present inventors previously filed (Japanese Patent Application No. 1-335703).
) l, shows an X-ray fluoroscopic inspection device.

In the figure, the inspection device includes an X-ray irradiation device 1, a manipulator 2, and a manipulator 2. X-ray detector 3. It consists of a sensor drive device 4 and an X-ray fluoroscopic image creation device 5.

Moreover, the X-ray detector 3 consists of an optical fiber plate 3A in which one type of fluorescent material 3B is enclosed in a core part 3E surrounded by a cladding part 3D, and detects the X-rays transmitted through the object to be inspected 6. It is.

The function of the inspection device is to first irradiate the printed circuit board 7, which is the object 6 to be inspected, with X-rays. Next, manipulator 2
and the X-ray detector 3 are moved at a constant speed. Next, by image processing the detection signal S from the X-ray detector 3, a thickness image and the like of the printed circuit board 7 are created.

This makes it possible to inspect the voids 7d of the via holes 7a and their pattern short circuit portions 7c, which cannot be visually inspected on the printed circuit board 7 on which the intermediate layer wiring 7b is formed as shown in FIG.

[Problem to be solved by the invention]

By the way, the present inventors filed an application earlier (Japanese Patent Application No. 1-3357).
03) According to the X-ray fluoroscopic inspection apparatus, the cost can be reduced by simplifying the X-ray detector, and the internal state of an object can be inspected non-contact, non-destructively, and with high reliability.

However, in the X-ray detector 3 made of the optical fiber plate 3A in which one kind of fluorescent material 3B is sealed, a problem as shown in FIG. 16 may occur.

That is, in the emission spectrum of the same figure (a), for example, the fluorescent material 3B such as LazOz S : Tb3+ has a K absorption edge of 38.92[Kevl] and a peak of the dominant wavelength of the emission spectrum of 545[nml].

Generally, the X-ray absorption rate of a substance changes nonlinearly depending on the wavelength of the X-ray. For example, X-rays with short wavelengths have high energy, so when a substance is irradiated with X-rays, if the X-rays have passed through a portion with a high X-ray absorption rate, they are converted into fluorescence and used for photodetection. By performing image processing, a high-resolution thickness image can be obtained.

However, in the case of X-rays that have passed through a portion with a low X-ray absorption rate, it is not possible to obtain a high-resolution thickness image even if the X-rays are subjected to photodetection/image processing.

Also, for X-rays with long wavelengths, the situation is opposite to the previous case.

In other words, since X-rays with long wavelengths have low energy, in the case of X-rays that have passed through areas with a high X-ray absorption rate, it is difficult to obtain a high-resolution thickness image even if the X-rays are subjected to photodetection/image processing. However, in the case of X-rays that have passed through areas with low X-ray absorption, a high-resolution thickness image can be obtained by converting them into fluorescence and performing photodetection/image processing. be able to.

As a result, as shown in the same figure (), due to the difference in the X-ray absorption rate of the materials constituting the printed circuit board 7, for example, a contrast difference may occur between the thickness images of the pattern short-circuit portion 7C and the void 7d. .

This is because the X-ray detection range of the X-ray detector 3, which is composed of the optical fiber plate 3A in which one type of fluorescent material 3B is sealed, is narrow.

The present invention was created in view of the problems of the conventional example, and can detect many types of fluorescent materials without depending on the X-ray detection range based on the emission spectrum of one type of fluorescent material sealed in an optical fiber plate. The object of the present invention is to provide an X-ray fluoroscopic inspection device and an X-ray fluoroscopic inspection method that improve the X-ray detection range based on the emission spectrum and make it possible to acquire high-resolution thickness images.

[Means to solve the problem]

FIGS. 1(a) to (d) are diagrams of the principle of the X-ray fluoroscopic inspection apparatus according to the present invention, and FIGS. 2(a) and () are diagrams of the principle of the X-ray fluoroscopic inspection method according to the present invention. A flowchart is shown for each.

As shown in FIG. 1(a), the first device includes: , an X-ray detection means 13 for detecting the X-ray L1 transmitted through the object to be inspected 16, a second moving means 14 for moving the X-ray detection means 13, - detection from the X-ray detection means 13; an X-ray fluoroscopic image generating means 15 that creates a fluoroscopic image of the object to be inspected 16 based on the signal Si, and the X-ray detecting means 13 includes two or more fluorescent materials 13 having different X-ray absorption characteristics.
B (Bl, B2...Bi) sealed therein, an optical fiber plate 13A, an optical filter 13C provided in the fluorescence generating part of the optical fiber plate 13A, and a light that detects the light L2 that has passed through the optical filter 13C. Detection means 1
The first method is characterized by consisting of 3D, and the second method is
As shown in Figure (a), first, in Step P1, the object to be inspected 16 is irradiated with X-rays L1, and then in Step P2, the X-rays L1 that have passed through the object to be inspected 16 are irradiated with two or more wavelengths λ1.゜λ2...λn fluorescence L21. L22...
L2n, and then, in step P3, the converted fluorescence L21. L22...L2n is selectively detected, and then, in step P4, the target to be inspected 1 is detected based on the specific fluorescence L2i subjected to the selectively detecting process.
The second device is the first device, and as shown in FIG. 1 ( ), the X-ray detection means 13 has Two or more different fluorescent materials 13B (BI B2...B
i), a first optical filter CI provided on one of the fluorescence generating parts of the optical fiber plate 13A, and the optical fiber plate 1
The light L21 . The first step detects L22. It is characterized in that it consists of second light detection means D1, D2, the third device being the first or second device,
As shown in Figure (C), the fluorescent material 13B CB1. on the two sides having different X-ray absorption characteristics. It is characterized in that two or more optical fiber plates 13A encapsulating B2...Bi) are laminated, and the fourth device is, as shown in FIG. 1(d), ．． L32...L3n is the object to be inspected 1
A plurality of X-ray irradiation means A1, A2...An
and %1 moving means 12 for moving the object to be inspected 16.
and X-rays L31 on the two sides that passed through the object to be inspected 16.
, L32...X-ray detection means 17 for detecting L3n
and a second moving means 1 for moving the X-ray detection means 17.
4 and the detection signal S on the two sides from the X-ray detection means 17
1, S2...Sn, and an X-ray fluoroscopic image generation means 18 for creating a fluoroscopic image of the object to be inspected 16 based on the X-ray irradiation means AlA2...An and the object to be inspected 16. is provided with a plurality of X-ray filters F1, F2...Fn, and the X-ray detection means (7) encapsulates fluorescent materials 13B (Bl, B2...Bi) on two sides having different X-ray absorption characteristics. an optical fiber plate 13A, a plurality of optical filters C1, C2, .
C2...Light L41. which passed through Cn. L42...
A plurality of light detection means D1, D2...D detecting L4n
The second method is as shown in FIG.
In step P1, X-rays L31. with different wavelengths. L32・
...L3n is irradiated onto the object to be inspected 16 from multiple directions, and then, in step P2, the X-rays L31. L32...L3n with multiple wavelengths λ
1. λ2...Fluorescence of An L41. L42...L
Furthermore, in step P3, the fluorescent lights L41, L42, . . . The present invention is characterized in that the internal inspection process of the object to be inspected 16 is carried out based on the above-mentioned object, thereby achieving the above object.

[For production]

According to the first device of the present invention, the optical fiber plate 13A encapsulates fluorescent materials 13B (Bl, B2...Bi) on two sides having different X-ray absorption characteristics, and the fluorescence of the optical fiber plate eye 3A. Optical filter 13C provided in the generating section
An X-ray detection means 13 is provided, which includes a light detection means 13D that detects the light L2 that has passed through the optical filter 13C.

For example, if X-rays with high energy and short wavelengths are irradiated onto the inspection object 16, the X-rays L1 that have passed through the portion with high X-ray absorption rate are converted to fluorescence L2 based on the emission spectrum of the fluorescent material B1, The fluorescence L2 is detected via the optical filter 13C, and then the light detection means 13
By performing image processing from D based on the detection signal Si, a high-resolution thickness image of the object to be inspected 1G can be obtained.

In addition, the X-ray L1 transmitted through the part with low X-ray absorption rate is
The fluorescence L2 is converted into fluorescence L2 based on the emission spectrum of the fluorescent material B2, and the fluorescence L2 is detected via the optical filter 13C. Thereafter, image processing is performed based on the detection signal St from the light detection means 13D. Similarly to the above case, a high-resolution thickness image of the object to be inspected 16 can be acquired.

Furthermore, if X-rays with low energy and long wavelengths are irradiated onto the object to be inspected 16, the X-rays L1 that have passed through the portion with a high X-ray absorption rate are converted to fluorescence L2 based on the emission spectrum of the fluorescent material B3. , the fluorescence L2 is detected via the optical filter 13C, and then the light detection means 1
By performing image processing based on the 3D detection signal Si, a high-resolution thickness image of the object to be inspected 16 can be obtained as in the previous case.

In addition, the X-ray L1 that passed through the part with low X-ray absorption rate also
The fluorescence L2 is converted into fluorescence L2 based on the emission spectrum of the fluorescent material B4, and the fluorescence L2 is detected via the optical filter 13C. Thereafter, image processing is performed based on the detection signal Si from the photodetection means I3D, so that the above-mentioned Similarly, a high-resolution thickness image of the object to be inspected 16 can be acquired.

Therefore, it is possible to expand the X-ray detection range of the Xis detection means 13, making it possible to observe a plurality of X-ray fluoroscopic images having different wavelengths over a wide range.

As a result, if the X-ray absorption rate of a substance changes non-linearly depending on the wavelength of the X-ray, for example, as in the conventional example shown in FIG. Even in this case, it is possible to suppress as much as possible the occurrence of a contrast difference between the thickness image of the pattern short circuit portion 7C and the void 7d.

According to the first method of the present invention, in step P2, the X-ray L1 transmitted through the object to be inspected 16 is transmitted to the wavelength λ1 on two sides.
λ2...An fluorescence L21. L22...L2n are converted, and in step P4, an internal inspection process of the object to be inspected 16 is performed based on the specific fluorescence L2i that has been selectively detected.

Therefore, since many types of thickness images of the object to be inspected 16 are obtained, selection and extraction processing can be performed to select a high-resolution thickness image requested by the observer from among them.

As a result, the inventors filed an application earlier (Japanese Patent Application No. 1-335
Similar to the X-ray fluoroscopic inspection apparatus described in 703), the internal state of an object can be inspected non-contact, non-destructively, and with high reliability.

Further, according to the second device of the present invention, the optical fiber plate 13A of the first device and the optical fiber plate 13A
A first optical filter C provided on one side of the fluorescence generating section of
I, the second optical filter C2 provided on the other side of the fluorescence generating section of the optical fiber plate 13A, and the first optical filter C2. Second optical filter CI.

Light L21. that passed through C2. The first step detects L22.
X-ray detection means 13 consisting of second photodetection means D1 and D2
is provided.

For example, if X-rays Ll are irradiated onto the object to be inspected 16, the X-rays L1 that have passed through a portion with a high X-ray absorption rate are converted to fluorescence L2 based on the emission spectrum of fluorescent material B"1, and the fluorescence L2 is detected via the first optical filter CI, and then subjected to image processing based on the detection signal Si from the first light detection means DI, thereby obtaining a high-resolution thickness image of the workpiece to be inspected 6. can be obtained.

Also, at the same time,
l is the fluorescence L2 based on the emission spectrum of the fluorescent material B2
The fluorescence L2 is detected via the second optical filter C2, and then image processing is performed based on the detection signal Si from the second light detection means D2, as in the previous case. In addition, a high-resolution thickness image of the object to be inspected 16 can be acquired.

Therefore, the X-ray detection function of the X-ray detection means 3 can be expanded compared to the first device.

This makes it possible to simultaneously detect multiple X-ray fluoroscopic images with different wavelengths.

Furthermore, according to the third device of the present invention, the fluorescent materials 13B (B1, B2...
・The optical fiber plate 13A sealed with Bi) is constructed by stacking the above.

Therefore, the thickness image of the rainy surface of the object to be inspected 16 can be acquired at the same time. In addition, fluorescent material 13B CB
1. B2...Bi) emission colors are red and blue.

By selecting green, it is also possible to perform color image processing in a simulated manner.

As a result, the first. X-ray detection means 1 compared to the second device
The X-ray detection function of No. 3 can be further expanded. This makes it possible to simultaneously observe multiple X-ray fluoroscopic images with different wavelengths.

Moreover, according to the fourth apparatus of the present invention, the plurality of X-ray irradiation means A1, A2...An and the plurality of X-ray filters F1
, F2...Fn, and a plurality of optical filters C1, C2...
. . Cn and a plurality of light detection means D1, D2 . . . Dn are provided.

For example, X-rays L31, . L32...L3
When the inspected object 16 is irradiated with X-rays L31 . L32...L3n
is detected by the X-ray detection means 17 which is moved and scanned.

At this time, the X-ray detection means 17 detects the X-ray L31. L
32...L3n is subjected to fluorescence treatment by the fluorescent materials 13B [B1, B2...Bi] on the two sides having different X-ray absorption characteristics. Further, an optical filter C1 provided in the fluorescence generating part of the optical fiber plate 13A formed by laminating two or more
, C2・Cn, the light L41. L42...
L4n is detected by a plurality of photodetecting means D1, D2...Dn. As a result, a fluoroscopic image of the object to be inspected 16 is created by the X-ray fluoroscopic image generating means 18 based on the detection signals SL, S2, . . . , Sn on the two sides from the X-ray detecting means 17.

Therefore, simultaneous multidirectional fluoroscopic inspection of the object 16 to be inspected can be performed.

As a result, the present inventors were the first to publish [(Patent Application Hei 1-335
703) It becomes possible to improve the functionality of the X-ray fluoroscopic inspection apparatus.

Further, according to the second method of the present invention, the object to be inspected 16 is irradiated with X-rays L31, L32...L3n having different wavelengths from multiple directions, and the object to be inspected 16 is
X-ray L31. L32...L3n at multiple wavelengths λ1. λ2...λn fluorescence L41. L42...
The object to be inspected 1 is detected based on the fluorescence L4i of a plurality of specific wavelengths which are converted into L4n and selectively detected in step P4.
6 internal inspection processing has been performed.

Therefore, the depth image of the object to be inspected 16 can be reconstructed based on the fluorescence L4i of a plurality of specific wavelengths that have been irradiated onto the object to be inspected 16 from multiple directions.

This makes it possible to further improve the functionality compared to the functionality of the X-ray fluoroscopic inspection device of the first device.

〔Example〕

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

3 to 14 are diagrams for explaining an X-ray fluoroscopic inspection apparatus and an X-ray fluoroscopic inspection method according to an embodiment of the present invention.

(i) Description of the first embodiment FIG. 3 shows a configuration diagram of an X-ray visual inspection apparatus according to the first embodiment of the present invention.

In the figure, reference numeral 21 denotes an X-ray source that is an embodiment of the X-ray irradiation means 11, and irradiates an object to be inspected 26 held by a manipulator 22 with X-rays L1.

Reference numeral 22 denotes a manipulator 22, which is an embodiment of the first moving means 12, and is used to move and scan the object to be inspected 26 in the XYZ directions. This is similar to the X-ray fluoroscopic inspection apparatus previously filed by the present inventors (Japanese Patent Application No. 1-335703).

An X-ray detector 23 is an embodiment of the X-ray detection means 13, and converts the X-ray L1 from the object to be inspected 26 into fluorescence L2, which is detected by a CCD (photoelectric imaging device) 23D. It is something. Note that the X-ray detector 23 will be described in detail in FIGS. 4 to 6.

A stage rotation device 24 is an embodiment of the second moving means 14, and is used to hold the X-ray detector 23 and move and scan it in the X, Y, and Z directions.

Reference numeral 25 denotes an X-ray fluoroscopic image generation device which is an embodiment of the X-ray fluoroscopic image generation means 15, and creates a thickness image of the object to be inspected 26 based on the detection signal S from the X-ray detector 23. It is something. The X-ray fluoroscopic image generation device 25 is I1
0 circuit 25A, grayscale image input circuit 25B1 image memory 2
5C2 image transfer circuit 25D1 display circuit 25E and CPU
(Central processing unit) Consists of 25F.

Reference numeral 26 indicates an object to be inspected, such as a printed circuit board that requires internal inspection as shown in FIG.

A display 30 displays a thickness image of a printed circuit board or the like.

FIGS. 4(a) and 4(a) are configuration diagrams of an X-ray detector according to a first embodiment of the present invention, and FIG. 4(a) shows a perspective view thereof.

In the same figure (a), the X-ray detector 23 is
It is composed of an optical fiber plate 23A made up of a plurality of optical fibers disposed on E, and a CCD 23D connected via an optical filter 13 (not shown).

The same figure (]) is a cross-sectional view of the X-ray detector 23, and 23C
shows a thin film filter which is an example of the optical filter 13.

The thin film filter 23C is provided at one end of the light emitting part of the optical fiber plate 23A, and allows light of a specific wavelength) 4 to pass therethrough, and guides it to the CCD 23D.

FIGS. 5(a) and () are diagrams explaining the functions of the X-ray detector according to each embodiment of the present invention, and FIG. 5(a) shows a partial perspective view of the optical fiber plate. There is.

In the same figure (a), the optical fiber plate 23A consists of a core part 23F surrounded by a cladding part 23G, and in the cross-sectional view of the shaded part, two or more fluorescent materials 23B with different X-ray absorption characteristics are present in the core part 23F. is enclosed in.

The fluorescent material 23B includes, for example, Gdz02S:Tb"
10, LazOzS: Tb3+, Y202s: Tb3
+ and LaOBr: Tb3+, etc. are used (see the emission spectrum characteristic diagram in Figure 6).

The figure () shows the core part 23 of the optical fiber plate 23A.
It is a perspective view of F, and 81-B3 have shown the fluorescent material.

For example, the fluorescent material B1 has an X-ray absorption coefficient of AI,
It emits fluorescence L2 exhibiting an emission spectrum with a dominant wavelength λ1 in response to X-rays L1 from the object 26 to be inspected.

Further, the fluorescent material B2 has, for example, an X-ray absorption coefficient of Δ2, and a main wavelength λ with respect to the X-ray L1 from the object to be inspected 26.
This device emits fluorescence L2 having an emission spectrum of No. 2.

Similarly, the fluorescent material B3 has an X-ray absorption coefficient of Δ3, for example.
It emits fluorescence L2 exhibiting an emission spectrum with a dominant wavelength λ3 in response to X-rays L1 from the object to be inspected 26.

Thereby, based on the wavelength of the X-ray L1 from the object to be inspected 26, it is possible to guide the fluorescence L2 showing the emission spectrum on two sides to the thin film filter 23C.

FIG. 6 is an emission spectrum characteristic diagram of the rare earth X-ray phosphor according to each example of the present invention.

In the figure, the vertical axis is the relative intensity C% of each phosphor,
The horizontal axis indicates the wavelength (nm).

Sl'l is the emission spectrum characteristic of the phosphor G d z O7S:Tb', and the dominant wavelength is 550 [nm]. SF3 is the emission spectrum characteristic of the phosphor L a 20□S:Tb3+, and the dominant wavelength is 400 [nml]. SF3 is the emission spectrum characteristic of the phosphor Y20□S:Tb3+, and the dominant wavelength is 550 Enml,! ! l-
Become. SF3 has an emission spectrum characteristic of the phosphor La0Br:Tb', and has a dominant wavelength of 430 [nm].

FIG. 7 is a diagram for explaining the CT processing according to each embodiment of the present invention, and shows a supplementary explanatory diagram of the image generation function of the X-ray fluoroscopic imaging device 25 of the apparatus.

In the figure, CT (Computed Tomogr
aphty) processing is similar to the X-ray fluoroscopic inspection device OCT processing previously published by the present inventors in IJ (Japanese Patent Application No. 1-335703). Here, the processing will be briefly explained.

For example, an X-ray L
1 is irradiated, if there is a location that absorbs laLl at a certain point, move the X-ray detector 23 to an angle θ1 and measure the light intensity (ray amount corresponding to the integral value) and the X-ray detector 23 at an angle θ
2, a certain point (f (xo,
yo) ) is specified, and a thickness image of the object to be inspected 26 can be obtained by processing to generate a grayscale image at this position.

In this way, according to the apparatus of the first embodiment of the present invention, the fluorescent material 23B (B
1, B2...Bi] is enclosed in an optical fiber plate 2
3A, an optical filter 23C provided in the fluorescence generating part of the optical fiber plate 23A, and the optical filter 23C.
X &
'i! A detector 23 is provided.

For example, if X-rays L1 with high energy and short wavelengths are irradiated onto the object to be inspected 26, the X-rays L1 that have passed through a portion with a high X-ray absorption rate are converted into fluorescence L2 based on the emission spectrum of the fluorescent material Bl. , the fluorescence L2 is detected via the optical filter 23C, and then the CCD 23
By performing image processing based on the detection signal S from D, a high-resolution thickness image of the object to be inspected 26 can be obtained.

In addition, the X-ray L1 transmitted through the part with low X-ray absorption rate is
The fluorescence L2 is converted into fluorescence L2 based on the emission spectrum of the fluorescent material B2, and the fluorescence L2 is detected via the optical filter 23C. Then, image processing is performed based on the detection signal S from the CCD 23D, as in the previous case. In addition, a high-resolution thickness image of the object to be inspected 26 can be acquired.

Furthermore, if X-rays with low energy and long wavelengths are irradiated onto the inspection target 26, the X-rays L1 that have passed through the portion with high X-ray absorption rate are converted to fluorescence L2 based on the emission spectrum of the fluorescent material B3, The fluorescence L2 is detected via the optical filter 23C, and then image processing is performed based on the detection signal S from the CCD 23D, thereby obtaining a high-resolution thickness image of the object to be inspected 26, as in the previous case. can do.

In addition, the X-ray Ll transmitted through the part with low X-ray absorption rate is
The fluorescence L2 is converted into fluorescence L2 based on the emission spectrum of the fluorescent material B4, and the fluorescence L2 is detected via the optical filter 23C. Then, image processing is performed based on the detection signal S from the CCD 23D, as in the previous case. In addition, a high-resolution thickness image of the object to be inspected 26 can be acquired.

For this reason, the X-ray detection range of the X-ray detector 23 is expanded compared to the X-ray detector of the X-ray fluoroscopic inspection device that the present inventors previously filed (Patent Application No. 1-335703). can be achieved. From this, multiple Xs with different wavelengths
It becomes possible to observe line perspective images over a wide range.

As a result, when the X-ray absorption rate of a substance changes non-linearly depending on the wavelength of the X-ray, for example, when the X-ray absorption rate of the substance constituting the printed circuit board 7 etc. differs as in the conventional example, Also, it becomes possible to suppress as much as possible the occurrence of contrast differences in the thickness image such as the pattern short-circuit portion 7C and the void 7d.

Next, the X-ray fluoroscopic inspection method according to the first embodiment of the present invention will be explained while supplementing the operation of the apparatus.

FIG. 8 shows a flowchart of the X-ray fluoroscopic inspection method according to the first embodiment of the present invention.

In the figure, for example, when inspecting the inside of a printed circuit board or the like as shown in FIG. 16, first, in step P1, the printed circuit board or the like is irradiated with X-rays L1. At this time, set the printed circuit board etc. on the manipulator 22 and
X-rays L1 are generated from a radiation source 21.

Next, in step P2, the X-ray L transmitted through the printed circuit board, etc.
1 to three dominant wavelengths λ1. λ2.・Fluorescence of λ3 L21.
L22. Conversion processing is performed in L23. Here, for example, when the X-ray L1 acts on the three types of fluorescent materials B1 to B3 sealed in the core part 23F of the optical fiber plate 23A, the three dominant wavelengths λ1°λ2. Fluorescence L of λ3
21. L22. L23 undergoes total reflection and reaches the thin film filter 23C of the light emitting section.

Next, the fluorescence L21 converted in step P3,
L22. The selection detection process of L23 is performed. At this time, by changing the filter characteristics of the thin film filter 23C,
The light L2 with the highest light intensity can be selected and detected.

Thereafter, an internal inspection process of the printed circuit board, etc. is performed based on the specific fluorescence L21 that has been selectively detected in step P4. For example, if the fluorescence L21 passes through the thin film filter 23C and is detected by the CCD 23D, then the CCD 23D
The X-ray fluoroscopic image generation device 25 based on the detection signal S from
By performing CT processing, a grayscale image of a printed circuit board or the like is generated.

Thereby, a thickness image of a printed circuit board, etc. can be obtained.

In this way, according to the inspection method according to the embodiment of the present invention, the X-rays L1 transmitted through the printed circuit board in step P2 are divided into three dominant wavelengths λ1. λ2. Fluorescence of λ3 L21. L2
2. In step P4, the internal inspection of the substrate is performed based on the specific fluorescence L21 that has been selectively detected.

Therefore, since many types of thickness images of the printed circuit board can be obtained, it is possible to perform selection and extraction processing to select a high-resolution thickness image desired by the observer from among them.

As a result, the present inventors filed an application earlier (Patent Application No. 1-335).
703) Similar to other X-ray fluoroscopic inspection devices, the internal state of objects can be inspected non-contact, non-destructively, and with high reliability.

(11) Description of Second Embodiment FIG. 9 shows a configuration diagram of an X-ray fluoroscopic inspection apparatus according to a second embodiment of the present invention.

In the figure, the difference from the first embodiment is that in the second embodiment, two types of detection signals S1,
S2 is what is output.

Components having the same names as those in the first embodiment have the same functions, so description thereof will be omitted.

Further, the X-ray detector 33 will be explained with reference to FIG. Here, the grayscale image input circuit 35B in the X-ray fluoroscopic image generation device 35 receives two types of detection signals 31. Input S2 at the same time. Thereby, a thickness image of the object to be inspected 26 is generated and processed via the CPU 35F and the image transfer circuit 135D based on the two types of detection signals S1 and S2.

FIG. 10(a), () is a configuration diagram of an X-ray detector according to a second embodiment of the present invention, and FIG. 10(a) shows a perspective view thereof.

In the same figure (a), the X-ray detector 33 is
An optical fiber plate 33A on which a plurality of optical fibers are arranged, and a first and second CCD 3 connected to both ends thereof.
It consists of 31,332 pieces.

In addition, the same figure () is a cross-sectional view of the X-ray detector 33,
C1 and C2 are the first. A second thin film filter is shown, respectively.

In the figure (), an optical fiber plate 33A is filled with fluorescent materials B1, B2, . . . , Bi on two sides having different X-ray absorption characteristics, as in the first embodiment. Also, C
Reference numeral 1 denotes a first thin film filter, which is an embodiment of the first optical filter, and is provided on one side of the fluorescence generating section of the optical fiber plate 33A. Its function is to use a specific wavelength λ1
The light L21 is transmitted through the light L21.

C2 is a second thin film filter which is an example of the second optical filter, and is provided on the other side of the fluorescence generating section of the optical fiber plate 33A. Its function is to use a specific wavelength λ
The second light L22 is allowed to pass therethrough.

331 is a first CCD and a first thin film filter C
1 and outputs a detection signal S1. Similarly, 332 is a second CCD,
It detects the light L22 that has passed through the second thin film filter C2 and outputs a detection signal S2.

In this way, according to the device of the second embodiment of the present invention, the optical fiber plate 33A like the first device and the first fluorescent light generating portion provided on one of the fluorescence generating portions of the optical fiber plate 33A are provided. A thin film filter CI, a second thin film filter C2 provided on the other side of the fluorescence generating section of the optical fiber plate 33A, and a first thin film filter C2. The first filter detects the light L21°L that has passed through the second thin film filters C1 and C2. 2nd CCD3
An X-ray detector 33 consisting of 31 and 332 is provided.

For example, if X-rays L1 are irradiated onto the object to be inspected 26, the X-rays L1 that have passed through a portion with a high X-ray absorption rate are converted to fluorescence L2 based on the emission spectrum of the fluorescent material Bl, and the fluorescence L2 is 1 thin film filter CI, and then the detection signal S from the first CCD 331
By performing image processing based on 1, a high-resolution thickness image of the object to be inspected 26 can be obtained.

At the same time, the XML transmitted through the part with low X-ray absorption rate
I is the fluorescence L2 based on the emission spectrum of the fluorescent material B2
The fluorescence L2 is detected via the second thin film filter C2, and then image processing is performed based on the detection signal S2 from the second CCD 332.
As in the previous case, a high-resolution thickness image of the object to be inspected 26 can be acquired.

Therefore, the X-ray detection function of the X-ray detector 33 can be expanded compared to the first device.

This makes it possible to simultaneously detect multiple X-ray fluoroscopic images with different wavelengths.

(iii) Description of the third embodiment FIGS. 11(a) and () are block diagrams of an X-ray detector according to the third embodiment of the present invention, and FIG. A perspective view is shown.

In the same figure (a), the first. The X-ray detector 4 of the third embodiment is different from the X-ray detectors 23 and 33 of the second embodiment.
3, optical fiber plates 23A are stacked.

This allows the X-ray detector 43 to simultaneously output many types of detection signals S1, S2, . . . Sn.

That is, the X-ray detector 43 has a three-layer stack of optical fiber plates 43A in which a plurality of optical fibers are arranged on an X-ray shielding plate 43E, and the first to third CCDs 431 to
433 are connected.

Moreover, the same figure () is a cross-sectional view of the X-ray detector 43,
01 to C3 indicate first to third thin film filters, respectively.

In the same figure (]), the optical fiber plate 43A is connected to the first. As in the second embodiment, the fluorescent materials B1, B2 . B3 is included. Also,
The first thin film filter C1 is the optical fiber plate 43A.
is provided on one side of the fluorescence generating section. Its function is to pass light L21 having a specific wavelength λ1.

The second thin film filter C2 is provided on one side of the fluorescence generating section of the optical fiber plate 43A, similarly to the first thin film filter C1. Its function is to use light L2 with a specific wavelength λ2.
2 is allowed to pass through.

The third thin film filter C3 is provided on one of the fluorescence generating portions of the optical fiber plate 43A similarly to the first and second thin film filters C1 and C2. Its function is to pass light L23 having a specific wavelength λ3.

431 is a first CCD and a first thin film filter C
1 and outputs a detection signal S1. Similarly, 432 and 433 are the second. Third
, and the second CCD. Third thin film filter C2, C3
The light L22. L23 is detected and the detection signal S2. It outputs S3.

According to the apparatus of the third embodiment of the present invention, fluorescent materials Bl, B2 .
The optical fiber plate 43A encapsulating B3 is constructed by laminating three layers.

Therefore, at least three thickness images of the object to be inspected 26 can be acquired at the same time.

With this, the fluorescent materials B1, B2. Change the emission color of B3 to red,
By selecting blue and green, color image processing can be performed in a simulated manner.

As a result, the first. X-ray detector 43 compared to the second device
The X-ray detection function of the X-ray detection function can be further expanded.

This makes it possible to simultaneously observe multiple X-ray fluoroscopic images with different wavelengths.

(iv) Explanation of the fourth embodiment FIG. 12 is a configuration diagram of an X-ray fluoroscopic inspection apparatus according to the fourth embodiment of the present invention, and FIG. A configuration diagram of such an X-ray detector is shown.

In FIG. 12, the difference from the first embodiment is that the fourth embodiment has three X, vi! L31~L3
In order to irradiate the object to be inspected 26 with the
X-ray filters F1 to F3 are used every 513 times. Furthermore, the X-ray detector 43 as in the third embodiment is used as the X-ray detector 53 (see FIG. 13).

Thereby, the depth image of the object to be inspected 26 can be reconstructed.

That is, 511 to 513 are a plurality of X-ray irradiation means A1,
A2...Three X-ray sources serving as an example of An,
The object to be inspected 26 is irradiated with X-rays L31 to L33.

F1 to F3 are multiple X-ray filters F1, F2...F
Three X-ray filters are one example of n, and are provided between the X-ray sources 511 to 513 and the object to be inspected 26. Its function is to select the wavelength of X-rays L31 to L33.

Note that the manipulator 52. Stage drive device 54.
An X-ray detector 53, which is an embodiment of the X-ray detection means 17. X
Regarding the X-ray fluoroscopic image generation device 55, which is an example of the fluoroscopic image generation means 18, the operational functions of the first to third embodiments have been explained, so the explanation will be omitted (see FIG. 3).

Thus, according to the apparatus of the fourth embodiment of the present invention, three X-ray sources 511-513 and three X-ray filters F1, F2 . F3, three thin film filters C1, C2, C3 as shown in FIG. 13, and three CCDs 531 to 5.
33 are provided.

For example, three X-rays emitted from the X-ray sources 511 to 513
Lines L31, L32. L33 has three X-ray filters F1, F2 . When the object to be inspected 26 is irradiated through the F3, three X-rays L31.
X-ray detector 53 where L32 and L33 are moved and scanned
Detected by At this time, the X-ray detector 53
Lines L31, L32. L33 is three fluorescent materials B1. with different X-ray absorption characteristics. B2. Fluorescence treatment is performed by B3. In addition, an optical fiber plate 5 formed by laminating three layers
Thin film filters C1 and C2 provided in the fluorescence generating section of 3A
, C3, the light L41. L42...L43 are detected by three CCDs 53] to 533. As a result, the three detection signals S1 and S from the X-ray detector 53
2. Based on S3, a fluoroscopic image of the object to be inspected 26 is created by the X-ray fluoroscopic image generation device 55.

Therefore, simultaneous multidirectional fluoroscopic inspection of the object 26 to be inspected can be performed.

As a result, the inventors were the first to issue a patent application (Patent Application No. 1-33
5703) It becomes possible to improve the functionality of the X-ray fluoroscopic inspection apparatus.

Next, the second X-ray fluoroscopic inspection method of the present invention will be explained while supplementing the operation of the apparatus according to the fourth embodiment.

FIG. 14 shows a flowchart of an X-ray fluoroscopic inspection method according to a second embodiment of the present invention.

In the figure, for example, when performing an internal inspection of a printed circuit board or the like as shown in FIG. 16 as in the first embodiment, first, in step P1, X-rays L31 and L3 having different wavelengths are
2. Irradiate L33 onto printed circuit boards, etc. from three directions. At this time, a printed circuit board or the like is set on the manipulator 22, and the X! aL31, L32.
Irradiate L33 onto a printed circuit board, etc.

Next, in step P2, the X-ray L transmitted through the printed circuit board, etc.
31. L32. L33 with three dominant wavelengths λ1. λ
2, λ3 fluorescence L41. L42. Conversion processing is performed in L43. Here, for example, the optical fiber plate 53
Three types of fluorescent materials B1~ sealed in the core part 53F of A
X-ray L31. L32. By the action of L33, the three dominant wavelengths λ1. λ2. Fluorescence L of λ3
41°L42. The light L43 undergoes total reflection and reaches the thin film filters 01 to C3 of the light emitting section.

Next, the fluorescence L4'l converted in step P3,
L42. The selection detection process of L43 is performed. At this time, by matching the filter characteristics of the thin film filters 01 to C3 in advance, the light L of the wavelength with the highest light intensity is
41. L42. L43 can be detected.

After that, the specific fluorescence L41. which was selectively detected in step P4. L42. Internal inspection processing of printed circuit boards, etc. is performed based on L43. For example, fluorescent L41L42
L43 passes through thin film filters 01 to C3 and enters the CCD
531 to 533, each CCD5
The X-ray fluoroscopic image generation device 55 performs CT processing based on the detection signals 81 to S3 from 31 to 533, thereby generating a grayscale image of a printed circuit board or the like.

Thereby, a depth image of a printed circuit board, etc. can be acquired.

In this way, according to the X-ray fluoroscopic inspection method according to the second embodiment of the present invention, X-rays L31 and L3 having different wavelengths are
2. The object to be inspected 26 is irradiated with L33 from three directions, and in step P2, the object to be inspected 26 is irradiated with X&? ! L
31. L32. L33 with three dominant wavelengths λ1. λ
2. λ3 fluorescence L41, L42. The three specific wavelengths of fluorescence L41, L42 . Internal inspection processing of the inspection target 26 is being performed based on L43.

For this reason, three specific wavelengths of fluorescence L41. L42. L43
Based on this, the depth image of the object to be inspected 26 can be reconstructed.

This makes it possible to further improve the functionality compared to the functionality of the X-ray fluoroscopic inspection device of the first device.

〔Effect of the invention〕

As explained above, according to each device of the present invention, the optical fiber plate encapsulates fluorescent materials on two sides with different X-ray absorption characteristics, and the light that passes through the optical filter of the fluorescence generating part is detected. An X-ray detection means comprising a detection means is provided.

Therefore, even if the object to be inspected is irradiated with X-rays of different energy wavelengths, the fluorescence from the object to be inspected can be detected based on the emission spectrum of the fluorescent material. This makes it possible to expand the X-ray detection range of the X-ray detection means, making it possible to observe a plurality of X-ray fluoroscopic images having different wavelengths over a wide range.

Furthermore, according to each inspection method of the present invention, X-rays that have passed through the object to be inspected are converted into fluorescence of wavelengths on two sides, and internal inspection of the object is performed based on the specific fluorescence that has been selectively detected. processed.

Therefore, since many types of thickness images of the object to be inspected can be obtained, it is possible to perform selection and extraction processing to select a high-resolution thickness image desired by the observer from among them.

As a result, the inventors filed an application earlier (Japanese Patent Application No. 1-335
703), the internal state of an object can be inspected non-contact, non-destructively, and with high reliability. In addition, it is possible to improve X-ray fluoroscopic inspection functions such as multidirectional simultaneous inspection processing and depth images.

[Brief explanation of drawings]

FIG. 1 is a principle diagram of the X-ray fluoroscopic inspection apparatus according to the present invention, FIG. 2 is a principle flowchart of the X-ray fluoroscopic inspection method according to the present invention, and FIG. 3 is a diagram showing the principle of the X-ray fluoroscopic inspection method according to the present invention. FIG. 4 is a configuration diagram of an X-ray detector according to the first example of the first actual titf of the present invention; FIG. 5 is a configuration diagram of an X-ray detection apparatus according to each embodiment of the present invention. 6 is a diagram explaining the emission spectrum characteristics of the rare earth X-ray phosphor according to each embodiment of the present invention. FIG. 7 is a diagram explaining the CT processing according to each embodiment of the present invention. 8 is a flowchart of the X-ray fluoroscopic inspection method according to the first embodiment of the present invention, FIG. 9 is a configuration diagram of the X-ray fluoroscopic inspection apparatus according to the second embodiment of the present invention, FIG. 10 is a block diagram of an X-ray detector according to a second embodiment of the present invention, FIG. 11 is a block diagram of an X-ray detector according to a third embodiment of the present invention, and FIG. 12 is a block diagram of an X-ray detector according to a third embodiment of the present invention. , a configuration diagram of an X-ray fluoroscopic inspection apparatus according to a fourth embodiment of the present invention, FIG. 13 is a configuration diagram of an X-ray detector according to a fourth embodiment of the present invention, and FIG. Flowchart of the X-ray fluoroscopic inspection method according to the second embodiment, FIG. 15 is a configuration diagram of the X-ray fluoroscopic inspection apparatus according to the conventional example, and FIG. 16 is a diagram illustrating problems related to the conventional example. be. (Explanation of symbols) 1], AI~An...X-ray irradiation means, 12...first
13.17... X-ray detection means, 14... Second moving means, 15.18... X-ray fluoroscopic image generation means, 13A...
Optical fiber plate, 13B, B i, B I ~ Bn - fluorescent material, L I, L
31~L3n-X-ray, L2. L21 to L2n, L41 to L4n - fluorescence (light passed through an optical filter), F1 to Fn... X-ray filter, 13C, C1 to Cn... optical filter, 13D, Dl
~Dn...Photodetection means, Si, Sl-Sn...Detection signal.

Claims (6)

[Claims] (1) X that irradiates the object to be inspected (16) with X-rays (L1)
A radiation irradiation means (11), a first moving means (12) for moving the object to be inspected (16), and a first moving means (12) for moving the object to be inspected (16).
) for detecting the X-rays (L1) transmitted through the
3), a second moving means (14) for moving the X-ray detection means (13), and a second moving means (14) for moving the X-ray detection means (13); The X-ray detection means (13) includes two or more fluorescent materials (13B [B1, B2...Bi 〕)
an optical fiber plate (13A) enclosing an optical fiber plate (13A), an optical filter (13C) provided in the fluorescence generating part of the optical fiber plate (13A), and the optical filter (13C).
A light detection means (13D) that detects the light (L2) that has passed through the
An X-ray fluoroscopic inspection device comprising: (2) The object to be inspected (16) is irradiated with X-rays (L1), and the X-rays (L1) that have passed through the object to be inspected (16) have two or more wavelengths (λ1, λ2...λn). Fluorescence (L21
, L22 .
An X-ray fluoroscopic inspection method, characterized in that an internal inspection process of the object to be inspected (16) is performed based on. (3) The X-ray fluoroscopic inspection apparatus according to claim 1, wherein the X-ray detection means (13) comprises two or more fluorescent materials (13B [B1, B2...Bi]) having different X-ray absorption characteristics. an optical fiber plate (13A) enclosing a first optical filter (C1) provided on one of the fluorescence generating parts of the optical fiber plate (13A); a second optical filter (C2) provided on the other side, and the first and second optical filters (
An X-ray fluoroscopic inspection apparatus comprising first and second light detection means (D1, D2) that detect light (L21, L22) that has passed through C1, C2). (4) The X-ray fluoroscopic inspection apparatus according to claim 1 or 3, wherein the two or more fluorescent materials (13B [
An X-ray fluoroscopic inspection device characterized in that two or more optical fiber plates (13A) encapsulating optical fibers (B1, B2...Bi]) are stacked. (5) A plurality of X-ray irradiation means (A
1, A2...An), a first moving means (12) for moving the object to be inspected (16), and a first moving means (12) for moving the object to be inspected (16);
6) Two or more X-rays (L31, L32...L
3n); a second moving means (14) for moving the X-ray detecting means (17);
Two or more detection signals (S
an X-ray fluoroscopic image generation means (18) for creating a fluoroscopic image of the object to be inspected (16) based on the X-ray irradiation means (A1, A2...An); ) and the object to be inspected (16), there are multiple X-ray filters (F1, F2
...Fn), and the X-ray detection means (17) encapsulates two or more fluorescent materials (13B [B1, B2...Bi]) having different X-ray absorption characteristics (13A). , a plurality of optical filters (C1, C2...Cn) provided in the fluorescence generating part of the optical fiber plate (13A), and light (L41) that has passed through the optical filters (C1, C2...Cn).
, L42...L4n).
D1, D2...Dn), and is characterized in that two or more of the optical fiber plates (13A) are laminated. (6) X-rays with different wavelengths (L31, L32...L3n
) is irradiated onto the object to be inspected (16) from multiple directions, and the X-rays (L31, L32) that have passed through the object to be inspected (16) are
...L3n) at multiple wavelengths (λ1, λ2...λn)
Conversion processing into fluorescence (L41, L42...L4n),
The converted fluorescence (L41, L42...L4n
), and the target to be inspected (
16) An X-ray fluoroscopic inspection method characterized by carrying out the internal inspection process.