JP2007206033A - Radiation detection unit and radiographic inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation detection unit in which a plurality of detecting substrates are layered densely, and also to provide a radiographic inspection device using the same. <P>SOLUTION: A semiconductor detection unit 20 comprises a layered body layered with the plurality of detecting substrates 22 on a support block 21, and the each detecting substrate 22 is constituted of a wiring board 24, two semiconductor detecting elements 25, a connector 26, a spacer 28, a bias voltage impressing wiring part 29, and the like. The upper and lower detecting substrates 22 are layered to make the respective spacers contact each other. The bias voltage impressing wiring part 29 is constituted of a base film 30, and a wiring layer 31 comprising: pad electrodes 31a, 31c on an under face of the base film 30; and a wire 31b for connecting the pad electrode 31a to the pad electrode 31c. The bias voltage impressing wiring part 29 is arranged between the spacer 28 and the detecting substrate 22 in an upper side thereof, and is stored in a space formed with respect to an under face of the upper wiring board 24 on a stepped part 28b of the spacer 28. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radiation detection unit having a radiation semiconductor detection element and a radiation inspection apparatus using the same, and more particularly to a radiation detection unit and a radiation inspection apparatus for detecting gamma rays emitted from a radioisotope in a subject.

  In recent years, tomographic apparatuses have been widely used to obtain information inside a living body (subject). Examples of the tomography apparatus include an X-ray computed tomography (X-ray CT) apparatus, a magnetic resonance imaging apparatus, a SPECT (single photon emission CT) apparatus, and a positron tomography (PET) apparatus. An X-ray CT apparatus irradiates a cross section of a subject with a narrow X-ray beam from multiple directions, detects transmitted X-rays, and calculates a spatial distribution of the degree of X-ray absorption in the cross section. It is calculated and imaged. As described above, the X-ray CT apparatus can grasp a morphological abnormality inside the subject, for example, a bleeding lesion.

  On the other hand, the PET apparatus has been actively developed in recent years because the function information in the subject can be accurately obtained. In a diagnostic method using a PET apparatus, first, a test drug labeled with a positron nuclide is introduced into a subject by injection or inhalation. The test drug introduced into the subject is accumulated in a specific part having a function corresponding to the test drug. For example, when a saccharide test drug is used, it is selectively accumulated at sites with high metabolism such as cancer cells. At this time, positrons are emitted from the positron nuclide of the test agent, and when these positrons and surrounding electrons are combined and annihilated, two gamma rays (so-called annihilation gamma rays) are emitted in a direction of about 180 degrees. The two gamma rays are simultaneously detected by a radiation detector arranged around the subject, and the image of the radioisotope in the subject is acquired by regenerating an image with a computer or the like. As described above, since the function information in the body of the subject can be obtained with the PET apparatus, the pathology of various intractable diseases can be elucidated.

  The PET apparatus is arranged so that a large number of gamma ray detectors surround the subject 360 degrees. The gamma ray detector includes a semiconductor detector including a semiconductor detection element and a detection circuit for electrically detecting gamma rays incident on the semiconductor detection element. The PET apparatus identifies the generation position of the gamma ray based on the detection signal indicating that the gamma ray from the detection circuit has entered and the position information of the semiconductor detection element on which the gamma ray has entered. Then, the PET apparatus regenerates an image of the distribution of the test drug in the subject by detecting a large number of gamma rays.

  Since annihilation gamma rays are emitted from the subject in a random direction, a large number of semiconductor detection elements are arranged in the semiconductor detector to improve the detection efficiency (ratio of the number of detected gamma rays to the number of annihilation gamma rays generated). Is done. For example, as shown in FIG. 1, a semiconductor detection element 103 in which anodes and cathodes are alternately stacked on semiconductor crystals and semiconductor devices 104 and 105 that perform signal processing are mounted in a housing 101. A radiation detection unit 100 having a substrate 102 has been proposed (see Patent Document 1).

A bias voltage is applied to the semiconductor crystal to collect electron-hole pairs generated by the incidence of gamma rays at the anode and the cathode, respectively. The bias voltage is set to an extremely high voltage in order to efficiently collect electron-hole pairs in a short time. For example, in Patent Document 1, the bias voltage is set to 300V.
JP 2005-128000 A

  Incidentally, in order to supply a bias voltage to the semiconductor detection element, wire wiring or a metal plate is usually used. In these cases, in order to stack the detection substrates and arrange the semiconductor detection elements at a high density, it is necessary to provide an insulating member that electrically insulates the wire wiring and the metal plate from the wiring substrate. Since a space occupied by the insulating member in addition to the wire wiring and the metal plate is required, there is a problem that it is difficult to arrange the semiconductor detection elements at high density. If an excessive gap is generated between the semiconductor detection elements, the ratio of gamma rays that pass through the gap increases, and the detection efficiency decreases.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a radiation detection unit capable of stacking a plurality of detection substrates at high density, and a radiation inspection apparatus using the radiation detection unit. is there.

  According to one aspect of the present invention, a wiring board, a semiconductor detection element that detects radiation fixed to the upper surface of the wiring board, a spacer fixed to the upper surface of the wiring board, and a bias voltage applied to the semiconductor detection element A detection substrate having a bias voltage application wiring portion for supplying a plurality of the detection substrates, and a fixing means for fixing a stacked body in which a plurality of the detection substrates are stacked. The semiconductor detection element includes a semiconductor crystal and the semiconductor A first electrode portion for applying a bias voltage to the upper surface of the crystal body; and a second electrode portion for extracting a signal to the lower surface of the semiconductor crystal body. A flexible support member, and a wiring layer comprising a pad electrode and a wiring electrically connected to the first electrode portion on a lower surface of the flexible support member, the semiconductor detection element and an upper detection substrate Provided between the wiring board Is the radiation detector, characterized by comprising is provided.

  According to the present invention, the bias voltage applying wiring portion is composed of a wiring layer composed of a film-like flexible support member, a pad electrode formed on the lower surface thereof, and wiring. Therefore, the height occupied by the bias voltage application wiring portion can be reduced, and the detection substrates can be stacked with high density. As a result, the gap between the semiconductor detection elements is reduced, and the detection efficiency is improved. Furthermore, since the flexible support member also has a function of electrically insulating the wiring layer and the upper detection substrate, a new insulating member is not required. it can.

  In addition, the spacer has a step portion that is lower than the upper surface on the inner side in the lateral direction of the upper surface, and the detection substrates adjacent to each other are in contact with the upper surface of the lower spacer and the lower surface of the upper spacer. The bias voltage applying wiring portion may be housed between the stepped portion and the wiring substrate of the detection substrate on the upper side. As a result, the bias voltage applying wiring portion is accommodated in the space above the step portion of the spacer, so that the layers can be stacked with higher density.

  According to another aspect of the present invention, any one of the above radiation detection units for detecting radiation generated from a subject containing a radioisotope, a detection circuit unit connected to the radiation detection unit, and the detection circuit unit There is provided a radiation inspection apparatus comprising: information processing means for acquiring distribution information of the radioisotope in a subject based on detection information including an incident time and an incident position of radiation acquired from the above.

  According to the present invention, since the plurality of semiconductor detection elements of the radiation detection unit are arranged at high density with each other, the detection efficiency is improved, and a precise inspection can be performed in a short time.

  According to the present invention, it is possible to provide a radiation detection unit in which a plurality of detection substrates can be stacked at a high density, and a plurality of semiconductor detection elements are arranged at a high density, and a radiation inspection apparatus using the radiation detection unit.

  Hereinafter, embodiments will be described with reference to the drawings.

  FIG. 2 is a block diagram showing the configuration of the PET apparatus according to the embodiment of the present invention. Referring to FIG. 2, the PET apparatus 10 is disposed around the subject S, detects a gamma ray, and processes detection data from the detector 11. An information processing unit 12 that regenerates image data at the position of the positron nuclide RI, a display unit 13 that displays image data, a control unit 14 that controls movement of the subject S and the detector 11, and the information processing The input / output unit 15 includes a terminal that sends instructions to the unit 12 and the control unit 14, a printer that outputs image data, and the like.

The detectors 11 _{1 to} 11 ₈ are arranged around the subject S over 360 degrees. Here, the body axis direction of the subject S is defined as the Z-axis direction (Z and −Z directions). The detector 11 may be movable relative to the subject S in the Z-axis direction. In FIG. 2, the PET apparatus 10 shows eight detectors 11 _{1 to} 11 _8, but these numbers are merely an example, and the number of the detectors 11 _{1 to} 11 ₈ is appropriately selected.

  The detector 11 includes a semiconductor detection unit 20 and a detection circuit unit 16. A test agent labeled with a positron nuclide RI in advance is introduced into the subject S. The semiconductor detection unit 20 is arranged so that the incident surface of gamma rays faces the subject S.

When the positron generated from the positron nuclide RI disappears, two gamma rays γ _a and γ _b are generated simultaneously. Since the two gamma rays γ _a and γ _b are emitted at an angle of about 180 degrees, the semiconductor detection element (reference numeral 25 shown in FIG. 4) of the semiconductor detection unit 20 of the detector 11 facing the subject S is sandwiched. Is incident on. Each of the semiconductor detection unit 20 gamma gamma _a, is gamma _b incident sends gamma gamma _a, electrical signals generated by the incidence of the gamma _b (detection signal) to the detection circuit unit 16.

The detection circuit unit 16 includes a detection circuit (not shown), and determines the time (incident time) when the gamma rays γ _a and γ _b are incident on the detection element based on the detection signal supplied from the semiconductor detection unit 20. Furthermore, the detection circuit unit 16 sends detection data such as the incident time and incident position information (such as the identification number of the element that detected the gamma ray) to the information processing unit 12. The detection circuit of the detection circuit unit 16 includes a mixed circuit of an analog circuit and a digital circuit.

  The information processing unit 12 performs coincidence detection and image data regeneration using an image regeneration algorithm based on the detection data. In the coincidence detection, when there are two or more pieces of detection data whose incident times substantially coincide with each other, it is determined that these pieces of detection data are valid and used as coincidence information. In the coincidence detection, detection data whose gamma ray incident times do not match is determined to be invalid and discarded. Then, based on the coincidence information, the detection element number included in the coincidence information, the position information of the detection element corresponding to the coincidence information, and the like, based on a predetermined image regeneration algorithm (for example, expectation maximization (Expectation Maximization method)) Regenerate the image data. The display unit 13 displays the image data regenerated in response to a request from the input / output unit 15.

  With the above configuration and operation, the PET apparatus 10 detects gamma rays from the positron nuclide RI selectively located in the body of the subject S, and reconstructs image data of the distribution state of the positron nuclide RI.

  FIG. 3 is a perspective view of the semiconductor detection unit according to the embodiment of the present invention, and FIG. 4 is an exploded perspective view of the detection substrate of the first embodiment. FIG. 3 is a view as seen from the direction in which gamma rays are incident, that is, from the front side of the semiconductor detection unit.

  Referring to FIGS. 3 and 4, the semiconductor detection unit 20 is composed of a laminated body in which a plurality of detection substrates 22 are laminated on a support base 21, and the laminated body is a fixed body composed of four bolts 23a and nuts 23b. It is fixed by the member 23. FIG. 4 shows a case where there are 16 detection substrates 22 as an example. The detection board 22 includes a wiring board 24, two semiconductor detection elements 25, a connector 26, a spacer 28, a bias voltage application wiring portion 29, and the like. The detection substrate 22 is laminated such that the spacers 28 of the upper and lower detection substrates 22 are in contact with each other. That is, the upper surface 28 a of the lower spacer 28 and the lower surface 28 c of the upper spacer 28 are in contact with each other, and the position of the detection substrate 22 in the vertical direction is defined by the spacer 28.

  FIG. 5 is a plan view of the wiring board. Referring to FIG. 5 together with FIGS. 3 and 4, the wiring substrate 24 may be a glass epoxy substrate, a ceramic substrate such as a polyimide substrate, a glass substrate, and an alumina substrate. On the surface of the wiring substrate 24, a pad electrode 24b for taking out a detection signal and a wiring pattern 24a for connecting the pad electrode 24b and the connector 26 are formed. The pad electrode 24b is formed in the same number as the conductive film of the second electrode portion of the semiconductor detection element 25 described later. The wiring board 24 is a so-called multilayer laminated wiring board formed in the wiring board 24 in addition to the wiring pattern 24a formed on the surface thereof. The wiring board 24 may be a single layer wiring board.

  In addition, since the wiring for applying bias voltage is not formed on the wiring board 24, the wiring pattern 24a can be arranged substantially line-symmetrically from the center in the width direction (X-axis direction) of the wiring board 24, for example. For this reason, it is possible to reduce warping or bending of the wiring board 24 due to the asymmetrical arrangement of the wiring pattern 24a, and to prevent a serious obstacle such as peeling of the semiconductor crystal element 25 from the wiring board 24 caused by excessive warping or bending. Can be avoided.

  The type of the connector 26 is not particularly limited. For example, a flat cable connector to which a flexible printed wiring board (FPC) or the like can be connected can be used.

  FIG. 6 is a cross-sectional view of the semiconductor detection unit shown in FIG. 3 taken along the line AA, and is a cross-sectional view passing through the pad electrode 31 a of the wiring layer 31. FIG. 6 shows only a cross section of two detection boards, and the other detection boards are omitted.

  Referring to FIG. 6 together with FIG. 3 and FIG. 4, the semiconductor detection element 25 includes a substantially flat semiconductor crystal 33 having a groove 33 a formed on the lower surface, and a first electrode formed on the upper surface of the semiconductor crystal 33. Part 34 and a second electrode part 35 formed on the lower surface of the semiconductor crystal 33.

The material of the semiconductor crystal 33 is, for example, cadmium telluride (CdTe), Cd _1-x Zn _x Te (CZT), thallium bromide (TlBr), silicon, etc. sensitive to gamma rays with energy of 511 keV. Can be mentioned. Moreover, the dopant for controlling electroconductivity etc. may be contained in these materials. Silicon is preferable because it has a higher mechanical strength than CdTe, and crystal defects are less likely to occur during processing. The semiconductor crystal 33 is obtained by forming a semiconductor crystal using a Bridgeman method, which is a semiconductor crystal growth method, or a moving heating method, and cutting it into a flat plate shape with a predetermined crystal orientation.

  In addition, a plurality of groove portions 33a are formed on the lower surface of the semiconductor crystal 33 so as to be spaced apart at equal intervals in the width direction (X-axis direction) and extend in the depth direction (Y-axis direction). By dividing the semiconductor crystal body 33 in the width direction by the groove 33a, the incident position of the gamma ray in the width direction can be detected more accurately.

  The first electrode portion 34 is made of a conductive film that substantially covers the upper surface of the semiconductor crystal 33. A negative bias voltage Vb is applied to the first electrode portion 34 to serve as a cathode. In the case where the semiconductor crystal 33 is made of CdTe, for example, a Pt film is used for the first electrode portion 34. The first electrode portion 34 is electrically connected to the pad electrode 31 a of the wiring layer 31 of the bias voltage applying wiring portion 29 by the conductive adhesive layer 38. The bias voltage Vb is a DC voltage and is set to, for example, −60V to −1000V.

  The second electrode portion 35 is formed on the lower surface of the semiconductor crystal body 33, on the surface of the convex portion between the groove portion 33a and the groove portion 33a, with a predetermined width in the X-axis direction and separated from adjacent electrodes. It consists of a plurality of conductive films extending in the axial direction. When the semiconductor crystal 33 is made of CdTe, the second electrode portion 35 is made of, for example, an Au (gold) film, and In (indium) is implanted and diffused on the second electrode portion 35 side of the semiconductor crystal 33. As a result, a Schottky junction is formed between the second electrode portion 35 and CdTe. Each conductive film of the second electrode portion 35 is fixed to a pad electrode 24b provided on the wiring substrate 24 by a conductive adhesive layer 36 such as a conductive paste or an anisotropic conductive adhesive.

  The pad electrode 24b is connected to a detection circuit of a detection circuit unit (not shown) via a wiring pattern (reference numeral “24a” shown in FIG. 5) and the connector 26. In the detection circuit, since it is grounded via a resistor, the second electrode portion 35 becomes an anode. Note that only one circuit connected to the conductive film of the second electrode portion 35 is shown and the others are omitted.

  Next, the operation of the semiconductor detection element 25 will be described. When gamma rays are incident on the semiconductor crystal 33, electron-hole pairs are generated stochastically. Since an electric field is applied to the semiconductor crystal body 33 in the direction from the second electrode portion 35 to the first electrode portion 34, holes are attracted to the first electrode portion 34 and electrons are attracted to the second electrode portion 35. An output signal (detection signal) is sent to the detection circuit of the detection circuit unit.

  The spacer 28 includes a flat base portion 28A extending in the X-axis direction, and a pair of arm portions 28B extending on the front side in the Y-axis direction (the incidence direction of gamma rays) on both sides in the X-axis direction of the base portion 28A. Have The spacer 28 is surrounded by a base portion 28A and a pair of arm portions 28B to form a space where the gamma ray incident side is open. In this space, two semiconductor detection elements 25 having the spacers 28 fixed to the wiring board 24 are accommodated. Contact between the semiconductor detection element 25 and the spacer 28 is avoided. Thereby, it becomes easier to position each other than the case where the semiconductor detection element 25 and the spacer 28 contact each other.

  The spacer 28 has a flat bottom surface 28c. When the lower surface 28c is used as a reference, the spacer 28 is provided with an upper surface 28a which is the highest surface and a stepped portion 28b which is lower than the upper surface 28a. The upper surface 28a is flat, and the position of the detection substrate 22 in the vertical direction is defined by the upper surface 28a and the lower surface 28c. Further, the lower surface 28 c is bonded to the upper surface of the wiring board 24 through an adhesive layer 41. Since the lower surface 28c is flat, the vertical position of the upper surface of the wiring board 24 can be determined accurately.

  The stepped portion 28 b is provided on the inner side in the X-axis direction of the upper surface 28 a and extends in the Y-axis direction of the spacer 28. As shown in FIG. 6, the bias voltage applying wiring portion 29 is accommodated on the step portion 28 b, and the wiring substrate 24 of the detection substrate 22 stacked thereon is accommodated, and the bias voltage applying wiring portion 29 is accommodated. The contact with the upper wiring board 24 is avoided. As a result, since the position of the detection substrate 22 in the vertical direction (Z-axis direction) is determined only by the thickness of the spacer 28, the semiconductor detection element 25 can be easily positioned in the vertical direction. Can be placed.

  Further, the spacer 28 is provided with openings 28-1 to 28-3 penetrating in the thickness direction. Two openings 28-1 are provided on each side of the spacer 28 in the X-axis direction. In the opening 28-1, the shaft of the bolt 23a for fixing the semiconductor detection unit 20 is inserted, and the inner diameter (diameter) thereof is set larger than the diameter of the bolt shaft. Two openings 28-1 are formed on both sides in the X-axis direction, but may be one or three or more. The openings 28-2 and 28-3 are provided, for example, for introducing an adhesive for fixing the wiring board 24 and the spacer 28 shown in FIG. The number of the openings 28-2 and 28-3 is not particularly limited, and may not be provided in the first embodiment.

  The spacer 28 is not particularly limited as long as the spacer 28 is a material having a modulus of elasticity that does not deform due to a vertical tightening force when the semiconductor detection unit 20 is fixed. For example, the spacer 28 is made of metal (alloy), ceramic material, or the like. Selected. The spacer 28 is particularly preferably made of a ceramic material. When a ceramic material is used for the spacer 28, the spacer 28 is molded by a mold, and the upper surface 28a and the lower surface 28c are formed with high precision by polishing. Since the ceramic material has good flatness and extremely high dimensional accuracy by polishing, the spacer 28 has good dimensional accuracy. The step portion 28b is relatively harder to polish than the upper surface 28a and the lower surface 28c, but the flatness and dimensions of the step portion 28b may be less accurate than the upper surface 28a and the lower surface 28c. There is an advantage that it is easy.

  FIG. 7 is a plan view of the bias voltage applying wiring portion, and FIG. 8 is a cross-sectional view of the semiconductor detection unit shown in FIG. In FIG. 7, the wiring layer 31 is indicated by a solid line, but is formed below the base film 30. FIG. 8 is a cross-sectional view taken along the wiring layer 31 shown in FIG.

  Referring to FIGS. 7 and 8 together with FIGS. 4 and 6, the bias voltage applying wiring portion 29 includes a base film 30, pad electrodes 31a and 31c formed on the lower surface of the base film 30, and pad electrodes 31a and 31c. The wiring layer 31 includes a wiring 31b that connects the two.

  The base film 30 is made of a flexible resin material, for example, polyimide or polyester, and polyimide is preferable in terms of excellent heat resistance. The base film 30 may be either a single layer or a multilayer laminate.

  The pad electrode 31 a is formed on the lower surface of the base film 30 at a position corresponding to each of the first electrode portions 34 of the two semiconductor detection elements 25.

  The pad electrode 31c is electrically connected to the pad electrode 31a by the wiring 31b, and is formed at the other end of the pad electrode 31a together with the opening 31c-1. The pad electrode 31c is provided at a position extending outward from the wiring substrate 24, and a bias terminal 42 to which a bias voltage is supplied (for example, a penetrating terminal made of a metal material in an insulating material such as a rod-shaped steatite). Are connected). The screw terminal (for example, “male thread”) of the bias terminal 42 is inserted into the opening 31c-1 of the pad electrode 31c, and is screwed with the screw part (for example, “female thread”) of the bias terminal 42 thereon. Thus, the bias terminal 42 and the pad electrode 31c are pressed and electrically connected. By connecting the pad electrodes 31 c of the upper and lower detection substrates 22 with the bias terminal 42, all the pad electrodes 31 c of the semiconductor detection unit 20 are electrically connected with a single bias terminal 42. In this way, the bias voltage can be easily supplied to a large number of detection substrates 22 with a simple structure. Further, by separating the bias terminal 42 from the connector 26 to which the detection signal is transmitted, the withstand voltage design of the connector 26 is facilitated.

  The pad electrodes 31a and 31c and the wiring 31b are made of a Cu film by electroplating or electroless plating, and the pad electrodes 31a and 31c are further formed with an Au film covering the surface of the Cu film.

  In the wiring layer 31, an insulating layer 39 such as a resist material is formed on the surface other than the pad electrodes 31a and 31c, that is, on the surface of the wiring 31b. The insulating layer 39 prevents the bias voltage wiring layer 31 from being in electrical contact with the first electrode portion 34 and the spacer 28 at portions other than the pad electrode 31a.

  Further, as described above, a bias voltage of −60 V to −1000 V is applied to the wiring layer 31, but the upper wiring substrate 24 and the wiring layer 31 are electrically insulated by the base film 30. . That is, the base film 30 functions as a support member for the thin wiring layer 31 and also functions as an insulating member for the upper wiring substrate 24. Thereby, since the bias voltage applying wiring portion 29 can be provided in a small space, the detection substrate 22 can be stacked at a high density.

  The base film 30 has a thickness of, for example, 25 μm to 50 μm, the pad electrodes 31a and 31c and the wiring 31b have a thickness of, for example, 18 μm, and the insulating layer 39 has a thickness of, for example, 20 μm. Therefore, since the total thickness of the bias voltage applying wiring portion 29 is about 63 μm to 88 μm, the stepped portion 28 b of the spacer 28 can be sufficiently accommodated in the stepped portion 28 b by setting it to 0.3 mm, for example.

  Further, the wiring layer 31 is arranged separately from the wiring pattern 24 a formed on the wiring board 24. This facilitates insulation measures in the wiring board 24.

  When the semiconductor detection unit 20 is assembled, the bias voltage application wiring portion 29 is regulated by the side walls on both sides in the X-axis direction of the step portion 28b of the spacer 28 and positioned in the X-axis direction. Further, for positioning in the Y-axis direction, the base film 30 may be provided with positioning holes 30-1 having a diameter of 0.5 mm, for example. By previously forming a reference mark on the spacer 28 and aligning the position of the positioning hole 30-1 with the reference mark, positioning in the Y-axis direction becomes easy.

  As shown in FIG. 4, the detection substrate 22 is disposed and fixed so that the semiconductor detection element 25 and the spacer 28 are in a predetermined positional relationship. The predetermined positional relationship is, for example, the positional relationship between the outer shape of the semiconductor detection element 25 and the side surface of the arm portion 28B of the spacer 28. With this setting, the positional relationship between the semiconductor detection element 25 and the spacer 28 on the XY plane is determined.

  According to the first embodiment, the bias voltage applying wiring portion 29 is configured by the base film 30 and the wiring layer 31 including the pad electrodes 31a and 31c and the wiring 31b formed on the lower surface thereof. Since the bias voltage applying wiring portion 29 can be formed thinner than the conventional one, the height occupied by the bias voltage applying wiring portion 29 can be reduced, and the detection substrate 22 can be stacked at a high density. As a result, the gap between the semiconductor detection elements 25 is reduced, and the detection efficiency is improved. Furthermore, there is an advantage that the height of the semiconductor detection unit 20 can be reduced and the size can be reduced.

  In the semiconductor detecting element 25 shown in FIG. 6, the semiconductor crystal 33 has a groove 33a formed on the second electrode portion 35 side. The semiconductor crystal 33 is a flat surface, and the second electrode portion is formed on the surface thereof. 35 may be provided. Furthermore, instead of the semiconductor crystal 33, an aggregate in which a large number of needle-shaped rectangular semiconductor crystals are bonded together may be used. These semiconductor crystal bodies are the same in the second embodiment described below.

(Second Embodiment)
The PET apparatus according to the second embodiment of the present invention is a modification of the PET apparatus according to the first embodiment, except that the wiring structure for supplying the bias voltage of the semiconductor detection unit is different, such as FIG. It is comprised similarly to the semiconductor detection unit shown in FIG.

  FIG. 9 is a perspective view of a semiconductor detection unit according to the second embodiment of the present invention, FIG. 10 is an exploded perspective view of a detection substrate according to the second embodiment, and FIG. 11 is a semiconductor shown in FIG. It is CC sectional view taken on the line of a detection unit.

  Referring to FIGS. 9 to 11, the semiconductor detection unit 50 includes a bias voltage supply wiring structure 59, a bias voltage application wiring portion 59, a bias power connection electrode 55 formed on the wiring substrate 24, and It comprises a connection terminal 56 and the like provided in the opening 28-1 of the spacer 28, which electrically connects the bias voltage application wiring portion 59 and the bias power supply connection electrode 55.

  The bias voltage applying wiring portion 59 is configured in substantially the same manner as the bias voltage applying wiring portion 29 shown in FIG. 7, but the base film 30 is substantially rectangular, the pad electrode 51 c is the opening of the spacer 28. It is formed at a position corresponding to the portion 28-1.

  A bias power supply connection electrode 55 is formed on the surface of the wiring board 24 from the position corresponding to the opening 28-1 of the spacer 28 to the end in the depth direction (Y-axis direction). A bias voltage is supplied to the bias power connection electrode 55 from an external DC power source.

  The connection terminal 56 is made of, for example, a cylindrical metal material. The connection terminal 56 is inserted into the opening 28-1 of the spacer 28, and a conductive adhesive made of a conductive adhesive such as a silver paste is provided between the pad electrode 51c of the wiring layer 51 and the bias power connection electrode 55. Each is connected by a layer 38. With the bias voltage supply wiring structure described above, a bias voltage is supplied to the first electrode portion 34 of the semiconductor detection element 25.

  According to the second embodiment, it is possible to provide the semiconductor detection unit 50 that has substantially the same effect as the semiconductor detection element 25 with a wiring structure different from that of the first embodiment.

  The preferred embodiment of the present invention has been described in detail above, but the present invention is not limited to the specific embodiment, and various modifications can be made within the scope of the present invention described in the claims.・ Change is possible.

  For example, in the above-described embodiment, the PET apparatus has been described as an example, but the present invention can be applied to a SPECT (Single Photon Emission Computed Tomography) apparatus.

It is sectional drawing of the conventional radiation detection unit. It is a block diagram which shows the structure of the PET apparatus which concerns on the 1st Embodiment of this invention. It is a perspective view of the semiconductor detection unit which concerns on 1st Embodiment. It is a disassembled perspective view of the detection board of a 1st embodiment. It is a top view of a wiring board. It is the sectional view on the AA line of the semiconductor detection unit shown in FIG. It is a top view of the wiring part for bias voltage application. FIG. 4 is a cross-sectional view of the semiconductor detection unit shown in FIG. 3 taken along the line BB. It is a perspective view of the semiconductor detection unit which concerns on the 2nd Embodiment of this invention. It is a disassembled perspective view of the detection board concerning a 2nd embodiment. It is CC sectional view taken on the line of the semiconductor detection unit shown in FIG.

Explanation of symbols

10 PET device 11, 11 ₁ to 11 ₈ detector 12 information processing unit 13 display unit 14 control unit 15 input unit 16 detector unit 20, 50 semiconductor detection unit 21 supporting stand 22 and 52 detect the substrate 23 fixing member 24 wiring board 24a wiring pattern 24b, 31a, 31c, 51c pad electrode 25 semiconductor detection element 26 connector 28 spacer 28A base 28B arm part 28a upper surface 28b stepped part 28c lower surface 29, 59 bias voltage applying wiring part 30 base film 30-1 positioning hole 31, 51 Wiring layer 31b Wiring 33 Semiconductor crystal 34 First electrode part 35 Second electrode part 36, 38 Conductive adhesive layer 39 Insulating layer 41 Adhesive layer 42 Bias terminal 55 Bias power supply electrode 56 Connecting terminal

Claims (7)

A wiring board; a semiconductor detection element for detecting radiation fixed to the upper surface of the wiring board; a spacer fixed to the upper surface of the wiring board; and a bias voltage applying wiring section for supplying a bias voltage to the semiconductor detection element. And a detection substrate having,
Fixing means for fixing a laminate in which a plurality of the detection substrates are laminated, and
The semiconductor detection element includes a semiconductor crystal body, a first electrode portion that applies a bias voltage to the upper surface of the semiconductor crystal body, and a second electrode portion that extracts a signal on the lower surface of the semiconductor crystal body,
The bias voltage applying wiring portion includes a film-like flexible support member, and a wiring layer including a pad electrode and wiring electrically connected to the first electrode portion on a lower surface of the flexible support member. And a radiation detector, which is provided between the semiconductor detection element and a wiring board of a detection board above the semiconductor detection element. The spacer has a step portion that is lower than the upper surface on the inner side in the horizontal direction of the upper surface,
The detection substrates adjacent to each other vertically are laminated such that the upper surface of the lower spacer and the lower surface of the upper spacer are in contact with each other,
2. The radiation detector according to claim 1, wherein the bias voltage applying wiring portion is accommodated between the step portion and the wiring substrate of the detection substrate above the step portion.   The radiation detector according to claim 1, wherein the bias voltage applying wiring portion has a bias voltage supply side extending outward from the detection substrate. The wiring board is formed with a bias power connection pad electrode to which a bias voltage is supplied on an upper surface thereof,
The radiation detector according to claim 1, further comprising a connection terminal that connects a wiring layer of the bias voltage application wiring portion and a pad electrode for connecting a bias power source. The spacer has an opening that penetrates the stepped portion in the thickness direction and exposes the surface of the wiring board,
The radiation detector according to claim 4, wherein the connection terminal is made of a cylindrical metal member and disposed in the opening.   The radiation detection unit according to claim 1, wherein the spacer is made of a ceramic material. The radiation detection unit according to any one of claims 1 to 6, which detects radiation generated from a subject containing a radioisotope,
A detection circuit unit connected to the radiation detection unit;
A radiation examination apparatus comprising: information processing means for acquiring distribution information of the radioisotope in a subject based on detection information including an incident time and an incident position of radiation acquired from the detection circuit unit.

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