JPH08271637A - Manufacture of radiation detector array - Google Patents

Abstract

PURPOSE: To easily control the interval between respective channels in a radiation detector array, to enhance the arrangement accuracy of the respective channels and to use a scintillator crystal without a waste when the radiation detector array is manufactured. CONSTITUTION: A rectangular parallelepiped-shaped scintillator crystal 1 is bonded onto a substrate 3 by an optical adhesive 2, the scintillator crystal 1 is cut in a prescribed width, and grooves 4 are formed. Thereby, a scintillator element 1A which has been divided at a prescribed pitch is formed. A shielding material and a reflecting material are inserted into, and fixed to, the grooves, and a photodiode array 5 is fixed and bonded onto the scintillator crystal 1 via an optical adhesive 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a radiation detector array used in a radiation imaging apparatus or the like.

[0002]

2. Description of the Related Art For example, in an X-ray tomography apparatus, an X-ray tube that rotates around the body axis of the subject and a detector that detects X-rays transmitted through the subject. Which is provided with at least the X-ray tube while rotating the X-ray tube by a predetermined angle about the body axis of the subject, and the X-ray is emitted to the subject, and the X-ray transmitted through the subject is output from the detector. The image reconstruction processing is performed based on the data obtained to obtain a tomographic image.

High quality images are required in this type of device in order to enable accurate medical judgment, and for this purpose, improvement in the performance of the detector is extremely important.

Conventionally, a radiation detector array is constructed as shown in FIG. A large number of radiation detectors each including a scintillator element 41 and a photoelectric conversion element 43 such as a photodiode adhered to the lower surface of the scintillator element 41 via an adhesive 42 having a high light transmittance are arrayed through a shielding plate 45 to prevent radiation. Forming a detector array.

When the radiation is incident on the upper surface of the scintillator element 41, the radiation is converted into light in the scintillator element 41, and the emitted light is detected by the photoelectric conversion element 43, converted into an electric signal, and proportional to the incident radiation dose. The extracted signal is extracted.

In order to construct such a radiation detector array, after cutting out from each scintillator element 41 from a rectangular parallelepiped scintillator crystal, a photoelectric conversion element 43 is adhered with an adhesive 42, and then a shielding plate 45 is inserted. Thus, the radiation detectors are precisely arranged on the support member 44. However, it is difficult to form each scintillator element to the same size in this process, and the radiation detectors are precisely arranged. It was not easy to do, and there was a problem in assembly accuracy.

Therefore, in order to easily form each scintillator element in the same size and improve workability and arrangement accuracy, a radiation detector array as shown in FIG. 7 has been considered. The rectangular parallelepiped scintillator crystal 51 is cut so that a part of the scintillator crystal 51 remains connected, and a plurality of grooves 5 are formed at equal intervals.
2 is formed to form the scintillator element 51A. Next, the photoelectric conversion unit 54 is bonded via the adhesive 53, and the groove 5
Insert the shielding plate into 2 and fix it.

In the radiation detector array constructed in this manner, the size of the scintillator element is determined by the formation of the first groove 52, and the assembling work proceeds with a part of the scintillator crystal 51 connected. Workability and arrangement accuracy are improved.

This radiation detector array is used as it is, or a method of cutting off the connected portion of the scintillator crystal, removing it by polishing, and coating the portion with a reflecting agent is considered.

[0010]

However, in the detector array of FIG. 7, although the workability of the detector assembly and the arrangement accuracy can be improved as compared with the method of FIG. 6, some scintillator crystals are connected. If left unchecked, crosstalk will occur between scintillator elements and performance will deteriorate.

Further, in order to prevent crosstalk, in the method of cutting off the connected portion of the scintillator crystal, removing it by polishing, and coating the portion with a reflecting agent, the removed portion or the coated portion is detected by the detector. As it does not play a role as, there was a great waste.

The present invention was devised to solve the above-mentioned problems. It is possible to easily control the spacing between the channels of the detector array, improve the alignment accuracy, and use the scintillator crystal without waste. The present invention provides a method of manufacturing a radiation detector array that can be used.

[0013]

In order to achieve the above object, a method of manufacturing a radiation detector array according to the present invention comprises a phosphor element which is arranged in an array and emits light by radiation, and a fluorescent element. When manufacturing a detector array having a photoelectric conversion element to detect, after fixing the block-shaped phosphor on the radiation-transmissive substrate, cut a number of grooves parallel to the block-shaped phosphor. To form a phosphor element array divided into an array, and thereafter, a photoelectric conversion element is bonded and fixed to the surface of each phosphor element array on the side opposite to the substrate.

[0014]

After the block-shaped phosphor is fixed to the radiation-transmissive substrate, a large number of grooves are cut in this phosphor to divide it into phosphor elements having a predetermined shape. Are arranged on the radiation-transmissive substrate while being fixed and not separated, and the photoelectric conversion elements are provided in this state, so that workability and arrangement accuracy are improved. Since all the phosphor crystals can be used as detectors, there is no waste and efficiency is high.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a method for manufacturing a radiation detector array according to the present invention, and FIG. 2 shows a detailed sectional view of the completed radiation detector array.

Reference numeral 1 is a block-shaped scintillator crystal as a phosphor for converting incident radiation into light, 2 and 6 are optical adhesives capable of transmitting radiation and light, and 3 is radiation made of ceramics such as alumina or crystals. Transparent substrate, 4
Is a cut groove, 5 is a photodiode array as a photoelectric conversion element for converting fluorescence in the scintillator crystal 1 into an electric signal, 7 is a shielding material, and 8 is a reflecting material.

First, as shown in (a), a rectangular parallelepiped scintillator crystal 1 is bonded onto a substrate 3 with an optical adhesive 2.

Next, as shown in (b), a large number of grooves 4 are cut in parallel with the scintillator crystal 1 using a multi-wire saw, a diamond cutter or the like to form each scintillator element 1A having a predetermined shape. At this time, the groove 4 to be cut is at the lower end of the scintillator crystal 1 or the depth of the optical adhesive 2,
Make no further cuts. In this way, scintillator element rows that are completely divided into an array at a predetermined pitch are formed.

Here, the shielding material 7 is centered, and both sides of the shielding material 7 are sandwiched by the reflecting material 8. Then, the shielding material 7 is inserted into and fixed to the groove 4. Then, as shown in FIG. A radiation detector array is completed by adhering and fixing the photodiode array 5 with an optical adhesive 6.

As can be seen from the detailed sectional view of FIG. 2, the scintillator crystal 1 is completely separated into each channel, and the shielding material 7 and the reflecting material 8 are inserted between each scintillator element 1A. The light emitted in the element 1A can be prevented from entering the adjacent scintillator element, and crosstalk can be prevented.

In the above embodiment, when the groove 4 is formed in FIG. 1B, the depth is set to the lower end of the scintillator crystal 1 or the depth of the optical adhesive 2. However, as shown in FIG. It is also possible to cut to the depth of, and to insert the shielding material 7 and the reflecting material 8 deeper by that much, and to make it longer than the length of the scintillator element in the depth direction.

With this arrangement, incident radiation can be prevented from entering the unrelated scintillator element, and the resolution can be improved.

FIG. 4 shows another embodiment.

Reference numeral 21 denotes a block-shaped scintillator crystal as a phosphor for converting incident radiation into light, and 22, 24, 2
8 is an optical adhesive that transmits radiation and light, 23 is a reflective film such as a white mylar film (mylar containing a pigment of titanium oxide), and 25 is a ceramic such as alumina having a thickness of about 0.3 mm. Alternatively, a radiation transmissive substrate made of crystal or the like, 26 is a cut groove, 27 is a shielding material,
Reference numeral 29 is a reflection film as a reflection material, and 29 is a photodiode array as a photoelectric conversion element for converting fluorescence in the scintillator crystal 21 into an electric signal.

First, as shown in (a), a rectangular parallelepiped scintillator crystal 21 is bonded onto the reflection film 23 with an optical adhesive,
Further, these are adhered onto the substrate 25 with an optical adhesive 24. Next, as shown in (b), a large number of grooves 26 are cut in parallel with the scintillator crystal 21 with a multi-wire saw, a diamond cutter, or the like, and each scintillator element 21 having a predetermined shape.
Form A. At this time, the groove 26 to be cut is formed at the lower end of the scintillator crystal 21 or the depth of the optical adhesive 22, and no further cut is made. In this way, scintillator element rows that are completely divided into an array at a predetermined pitch are formed.

Then, as shown in (c), the reflection film 27 is inserted into each groove 26 and fixed. Finally, as shown in (d), the photodiode array 29 is further adhered and fixed on the scintillator crystal 21 via the optical adhesive 28 to complete the radiation detector array.

In this way, the light emitted from the scintillator element 21A due to the incidence of radiation can be prevented from leaking to the substrate 25 due to the presence of the reflecting film 23 and can be taken into the photodiode array 29, so that the sensitivity is improved. improves.

Further, it is desirable that the reflection film 23 is formed of an aluminum film or a vapor deposition film in order to enhance the light shielding effect.

In the above embodiment, when the groove 26 is formed in FIG. 4B, the depth is set to the lower end of the scintillator crystal 21 or the depth of the optical adhesive 22.
Similarly to the above, as shown in FIG. 5, the substrate 3 may be cut to a predetermined depth, and the reflection film 27 may be inserted deeper by that amount to make it longer than the length of the scintillator element in the depth direction. This reduces crosstalk between adjacent scintillator elements and improves resolution.

As the radiation-transmissive substrate in each of the above embodiments, Be, Al, AlN, BN, CF may be used.
It may be RP, Si or the like.

As described above, the radiation-transmissive substrate arranged in the radiation incident direction is used as a dummy, and the scintillator crystal is fixed on the dummy substrate. The scintillator crystal is completely formed into a scintillator element having a predetermined shape without dividing the substrate itself. Since this substrate acts as a connecting material for each scintillator element and does not disturb the array of each scintillator element, the spacing between each channel of the detector array can be easily controlled and the array accuracy is improved. It is possible to use the scintillator crystal without waste, because it is not necessary to remove a part of the scintillator crystal unlike the conventional case.

[0033]

As described above, according to the method of manufacturing the radiation detector array of the present invention, the block-shaped phosphors are arranged on the radiation-transmissive substrate arranged in the radiation incident direction opposite to the radiation incident direction. After being adhered to the surface, the phosphor crystal is separated into phosphor elements of a predetermined shape.
The spacing between the channels can be easily controlled, the alignment accuracy can be improved, and the phosphor crystal can be used without waste.

[Brief description of drawings]

FIG. 1 is a diagram showing a method of manufacturing a radiation detector array according to an embodiment of the present invention.

FIG. 2 shows a cross section of a radiation detector array according to the invention.

FIG. 3 is a diagram showing another construction method of the radiation detector array according to the present invention.

FIG. 4 is a diagram showing a method of manufacturing a radiation detector array according to another embodiment of the present invention.

5 is a diagram showing another configuration method of the radiation detector array shown in FIG.

FIG. 6 is a diagram showing a conventional radiation detector array.

FIG. 7 is a diagram showing a conventional radiation detector array.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryoichi Sawada 1 Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto City Stock Company Shimadzu Sanjo Factory

Claims (2)

[Claims] 1. A method of manufacturing a detector array comprising phosphor elements arranged in an array and emitting light by radiation, and a photoelectric conversion element for detecting fluorescence from the phosphor elements, wherein the block is provided on a radiation transparent substrate. After fixing the strip-shaped phosphor, a plurality of grooves are cut in parallel with the block-shaped phosphor to form a phosphor element array divided into an array, and then each phosphor element on the opposite side of the substrate is formed. A method of manufacturing a radiation detector array, which comprises fixing photoelectric conversion elements to the surface of a row. 2. A reflective film is formed between the radiation transparent substrate and the block-shaped phosphor.
A method for manufacturing the radiation detector array described.