Photodetector and computer tomography system
The innovative photodetector design with staggered photodiode sections and scintillators addresses the inefficiencies in existing photodetectors, achieving a more compact and efficient integration with external components for improved computer tomography system performance.
Patent Information
- Application Number
- PCT/EP2024/088004
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-01-02
- Filing Date
- 2024-12-20
- Publication Date
- 2025-07-10
AI Technical Summary
Existing photodetectors and computer tomography systems lack an efficient and compact design that optimizes the arrangement of photodiode sections and scintillators, leading to suboptimal performance and integration with external components.
A photodetector design comprising multiple photodetector modules with staggered arrangements of photodiode sections and scintillators, where each module overlaps the peripheral portion of the previous one, and a holder with a gap to facilitate compact integration, allowing for uniform spacing and efficient signal processing.
The solution enables a more compact and efficient photodetector arrangement that enhances signal detection uniformity and integration with external components, improving the performance of computer tomography systems.
Smart Images
Figure EP2024088004_10072025_PF_FP_ABST
Abstract
Description
[0001] PHOTODETECTOR AND COMPUTER TOMOGRAPHY SYSTEM
[0002] Photodetectors , e . g . for use in a computer tomography system usually comprise a scintillator for converting incident electromagnetic radiation to electromagnetic radiation having a lower energy and a photodiode array for detecting the converted electromagnetic radiation .
[0003] Generally, ef forts are taken to provide an improved photodetector and an improved computer tomography system .
[0004] It is an obj ect of the present invention to provide an improved photodetector and an improved computer tomography system .
[0005] SUMMARY
[0006] According to embodiments , the above obj ect is achieved by the claimed matter according to the independent claims . Further developments are defined in the dependent claims .
[0007] According to embodiments , a photodetector comprises a carrier, a first photodetector module , and a second photodetector module . The first photodetector module comprises a first photodiode section and a first scintillator arranged over the first photodiode section, the first photodiode section comprising a first array of photodiodes and a first peripheral portion . The second photodetector module comprises a second photodiode section and a second scintillator arranged over the second photodiode section, the second photodiode section comprising a second array of photodiodes and a second peripheral portion . The first and the second photodetector modules are attached to the carrier so that a distance from a first main surface of the carrier to the second photodiode section is larger than the distance from the first main surface of the carrier to the first photodiode section and a portion of the second photodetector module overlaps the first peripheral portion .
[0008] For example , a portion of the second photodiode section may overlap the first peripheral portion .
[0009] According to embodiments , the first scintillator is arranged over the first array of photodiodes and the first scintillator is absent from the first peripheral portion .
[0010] For example , the second photodetector module may further comprises a holder arranged between the carrier and the second photodiode section .
[0011] According to embodiments , a gap may be formed in a surface of the holder remote from the second photodiode section .
[0012] By way of example , a surface of the holder supporting the second photodiode section may be inclined with respect to a plane parallel to the first main surface of the carrier .
[0013] According to embodiments , a pitch of first photodiodes of the first array of photodiodes may be di f ferent from the pitch of second photodiodes of the second array of photodiodes .
[0014] The photodetector may further comprise a third photodetector module comprising a third photodiode section and a third scintillator arranged over the third photodiode section . The third photodiode section may comprise a third array of photodiodes and a third peripheral portion . The third photodetector module may be attached to the carrier so that a distance from a first main surface of the carrier to the third photodiode section is larger than the distance from the first main surface of the carrier to the second photodiode section . Further, a portion of the third photodiode section may overlap the second peripheral portion . According to further embodiments , the photodetector may comprise even more than 3 photodetector modules which have been described above .
[0015] According to embodiments , a computer tomography system comprises a radiation source and the photodetector as described above .
[0016] BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this speci fication . The drawings illustrate the embodiments of the present invention and together with the description serve to explain the principles . Other embodiments of the invention and many of the intended advantages will be readily appreciated, as they become better understood by reference to the following detai led description . The elements of the drawings are not necessarily to scale relative to each other . Like reference numbers designate corresponding similar parts .
[0018] Fig . 1A shows a cross-sectional view of a photodetector according to embodiments .
[0019] Fig . IB shows a schematic top view of a photodiode section .
[0020] Fig . 2 shows a cross-sectional view of a photodetector according to further embodiments .
[0021] Fig . 3 shows a cross-sectional view of a photodetector according to further embodiments .
[0022] Fig . 4 is a schematic view of a computer tomography system according to embodiments . DETAILED DESCRIPTION
[0023] In the following detailed description reference is made to the accompanying drawings, which form a part hereof and in which are illustrated by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology such as "top", "bottom", "front", "back", "over", "on", "above", "leading", "trailing" etc. is used with reference to the orientation of the Figures being described. Since components of embodiments of the invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope defined by the claims.
[0024] The description of the embodiments is not limiting. In particular, elements of the embodiments described hereinafter may be combined with elements of different embodiments.
[0025] As employed in this specification, the terms "coupled" and / or "electrically coupled" are not meant to mean that the elements must be directly coupled together - intervening elements may be provided between the "coupled" or "electrically coupled" elements. The term "electrically connected" may describe a low- ohmic electric connection between the elements electrically connected together.
[0026] According to further embodiments and where appropriate, the term "electrically connected" may mean that the respective elements are "directly connected" or are "directly and permanently connected" . The terms " lateral" and "hori zontal" as used in this speci fication intends to describe an orientation parallel to a first surface of a substrate or semiconductor body . This can be for instance the surface of a wafer or a die .
[0027] The term "vertical" as used in this speci fication intends to describe an orientation which is arranged perpendicular to the first surface of a substrate or semiconductor body .
[0028] Fig . 1A is a cross-sectional view of a portion of a photodetector according to embodiments . A photodetector 10 comprises a carrier 100 which may e . g . be a PCB ("printed circuit board" ) . For example , contact elements may be formed in the carrier 100 and may extend from the first main surface 101 of the carrier to an opposing side thereof . The photodetector 10 further comprises a first photodetector module 110 and a second photodetector module 120 . For example , the photodetector modules 110 , 120 may be glued to the carrier 100 using an adhesive .
[0029] The first photodetector module 110 comprises a first photodiode section 112 and a first scintillator 114 arranged over the first photodiode section 112 . For example , the scintillator 114 may be configured to convert a wavelength of incident electromagnetic radiation to a larger wavelength . Moreover, a first anti-scatter element 118 may be arranged over the first scintillator 114 . As is illustrated in Fig . 1A, the scintillator 114 covers only a portion of the first photodiode section 112 .
[0030] As will be explained in more detail below, with reference to Fig . IB, the first photodiode section 112 may comprise a first array of photodiodes 115 and further a first peripheral portion 116 in which photodiodes are not arranged . The first scintil lator 114 may be arranged over the array of photodiodes 115 , whereas the first peripheral portion 116 is not covered by the first scintillator 114 .
[0031] The photodetector 10 further comprises a second photodetector module 120 having a similar structure as the first photodetector module 110 . In more detail , the second photodetector module 120 comprises a second photodiode section 122 . A second scintil lator 124 is arranged over a portion of the second photodiode section 122 . In a similar manner as has been described above , a second peripheral portion 126 is not covered by the second scintillator 124 . Moreover, an anti-scatter element 128 may be arranged over the second scintillator 124 . For example , the anti-scatter element 128 may comprise or may be composed of a tungsten-polymer composite .
[0032] The first photodiode section 112 may e . g . comprise more than 16 x 8 , e . g . more than 24 x 12 , e . g . more than 30 x 15 photodiodes 117 . The second photodiode section 122 may have the same si ze as the first photodiode section 112 . According to further embodiments , the second photodiode section 122 may comprise a smaller or a larger number of photodiodes 117 than the first photodiode section 112 . According to embodiments , a pitch of the photodiodes 117 of the first array 115 of photodiodes 117 may be di f ferent from the pitch of the photodiodes 117 of the second array 125 of photodiodes . According to further embodiments , the pitch of the photodiodes 117 of the first array 115 of photodiodes 117 may be equal to the pitch of the photodiodes 117 of the second array 125 of photodiodes .
[0033] The first and the second photodetector modules 110 , 120 may be attached to the carrier 100 , so that a distance d2 from a first main surface 101 of the carrier 100 to the second photodiode section 122 is larger than the distance dl from the first main surface 101 of the carrier 100 to the first photodiode section 112 . Moreover, as is illustrated in Fig . 1A, a portion of the second photodetector module 120 may overlap the first peri- opheral portion 116 of the first photodiode section 112 . For example , a portion of the second photodiode section 122 may overlap the first peripheral portion 116 of the first photodiode section 112 .
[0034] For example , as is illustrated in Fig . 1A, the second photodetector module 122 may further comprise a holder 127 which is arranged between the carrier 100 and the second photodiode section 122 . Due to the presence of the holder 127 , the distance d2 from a first main surface 101 of the carrier 100 to the second photodiode section 122 may be larger than the distance dl from the first main surface 101 of the carrier 100 to the first photodiode section 112 . As is further shown in Fig . 1A, a main surface 123 of the holder 127 adj acent to the second photodiode section 122 may be parallel to the first main surface 101 of the carrier 100 . For example , the holder 127 may be made of any suitable material , e . g . metal , plastic or resin .
[0035] For example , circuitry and processing elements , e . g . an ADC ("analog digital converter" ) may be arranged in the peripheral portion 116 , 126 . Elements of the first peripheral portion 116 may be electrically connected via a first wiring 119 to external components 105 . Further, elements of the second peripheral portion 126 may be electrically connected via a second wiring 129 to external components 105 . For example , the external components 105 may be arranged over the first main surface 101 of the carrier 100 . The external components 105 may further process signals detected by the first and second photodetector module 110 , 120 . The external components 105 may provide an electrical contact to the connector 102 . For example , the connector 102 may be configured to connect the external components 105 to further components of the computer tomography device 15 .
[0036] As is shown in Fig . 1A, a gap 121 may be formed in the holder 127 . In more detail , the gap 121 may refer to a recess formed in a surface of the holder 127 on a side remote from the second photodiode section 122 .
[0037] Since a portion of the first photodiode section 112 is not covered by the first scintillator 114 and, optionally, the first anti-scatter element 118 , and due to the presence of the gap 121 , the first photodetector module 110 and the second photodetector module 120 may be staggered . As a consequence , a portion of the second photodetector module 120 overlaps a portion of the first photodetector module 110 .
[0038] The first wiring 119 may be arranged in a portion of the gap 121 formed in the holder 127 . Moreover, the second photodetector module 120 may be arranged so that the external components 105 that may be electrically connected to the first photodiode section 112 are arranged within the gap 121 . In thi s way, the first photodetector module 110 and the second photodetector module 120 may be arranged in a compact manner .
[0039] In order to achieve a plane surface of the combined first and second photodetector modules 110 , 120 , a thickness of the second anti-scatter element 138 may be less than a thickness of the second anti-scatter element 128 .
[0040] Fig . IB shows a schematic top view of the first or the second photodiode section 112 , 122 . The first photodiode section 112 comprises a first array 115 of photodiodes 117 . Likewise , the second photodiode section 122 comprises a second array 125 of photodiodes 117 . Moreover, the first photodiode section 112 further comprises the peripheral portion 116 which may be arranged on one side of the array 115 of photodiodes 117 . The second peripheral portion 126 may be arranged in a corresponding manner . For example , a converter for converting charges into digital signals , e . g . an ADC may be arranged in the first peripheral portion 116 and the second peripheral portion 126 .
[0041] Fig . 2 shows a cross-sectional view of a photodetector 10 according to further embodiments . Di f fering from embodiments illustrated in Fig . 1A, a surface 123 of the holder 127 facing the second photodiode section 122 is not parallel to the first main surface 101 of the carrier 100 . In this way, a surface of the second photodiode section 122 may be tilted with respect to a hori zontal surface . Accordingly, in a computer tomography system comprising a radiation source , a distance to a point-shaped radiation source may be made more uni form . For example , a tilt angle a of the surface of the holder 127 may be in a range of 5 to 15 ° .
[0042] Fig . 3 shows a cross-sectional view of a photodetector 10 according to further embodiments . In addition to elements illustrated in Figs . 1A and 2 , the photodetector 10 of Fig . 3 comprises a third photodetector module 130 . The third photodetector module 130 may comprise a holder 127 for holding a third photodiode section 132 , a third scintillator 134 and a third antiscatter element 138 . The structure of the third photodetector module 130 may be similar or identical with the structure of the second photodetector module 120 . In order to achieve a plane surface of the combined first , second and third photodetector modules 110 , 120 , 130 , a thickness of the third anti-scatter element 138 may be less than a thickness of the second antiscatter element 128 . Elements of the third peripheral portion may be connected e.g. to external components 105 via a third wiring 139.
[0043] Moreover, a thickness of the holder 127 of the third photodetector module 130 measured in a vertical direction may be more than a thickness of the holder 127 of the second photodetector module 120. As is clearly to be understood, the photodetector 10 may comprise an arbitrary number of photodetector modules. This is indicated in Fig. 3 showing that the photodetector may comprise a plurality of further photodetector modules 140. The further photodetector module 140 may comprise a holder 127 for holding a further photodiode section 142, a further scintillator 144 and a further anti-scatter element 148. The structure of the further photodetector module 140 may be similar or identical with the structure of the second photodetector module 120. In order to achieve a plane surface of the combined first, second and further photodetector modules 110, 120, 140, a thickness of the further anti-scatter element 148 may be less than a thickness of the second anti-scatter element 128. Elements of the further peripheral portion may be connected e.g. to external components 105 via a further wiring 149.
[0044] Fig. 4 shows a schematic view of a computer tomography system 25 according to embodiments. The computer tomography system 25 comprises a photodetector 10 as has been described herein above. The photodetector 10 may be mounted to a computer tomography device 15, e.g. for evaluating the received signals. The computer tomography system 25 further comprises a radiation source 20 which may generate e.g. X-ray radiation for performing a measurement on a specimen 16, e.g. a human body or any kind of device to be inspected. When a holder 127 as e.g. illustrated in Fig. 2 is used, a detection surface of the photodetector 10 may be inclined with respect to a horizontal plane. According to the configuration described herein, it is possible to assemble a plurality of photodetector modules comprising a photodiode section to provide a large-si ze photodetector . The photodetector may be implemented using already used technology . Moreover, di f ferent si zes of photodiode sections 112 , 122 may be used for di f ferent photodetector modules 110 120 comprising integrated circuits for performing readout .
[0045] While embodiments of the invention have been described above , it is obvious that further embodiments may be implemented . For example , further embodiments may comprise any subcombination of features recited in the claims or any subcombination of elements described in the examples given above . Accordingly, this spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein .
[0046] LIST OF REFERENCES
[0047] 10 photodetector
[0048] 15 computer tomography device
[0049] 16 specimen
[0050] 20 radiation source
[0051] 25 computer tomography system
[0052] 100 carrier
[0053] 101 first main surface of carrier
[0054] 102 connector
[0055] 105 external components
[0056] 110 first photodetector module
[0057] 112 first photodiode section
[0058] 114 first scintillator
[0059] 115 first array of photodiodes
[0060] 116 first peripheral portion
[0061] 117 photodiode
[0062] 118 first anti-scatter element
[0063] 119 first wiring
[0064] 120 second photodetector module
[0065] 121 gap
[0066] 122 second photodiode section
[0067] 123 surface of the holder
[0068] 124 second scintillator
[0069] 125 second array of photodiodes
[0070] 126 second peripheral portion
[0071] 127 holder
[0072] 128 second anti-scatter element
[0073] 129 second wiring
[0074] 130 third photodetector module
[0075] 132 third photodiode section
[0076] 134 third scintillator
[0077] 138 third anti-scatter element
[0078] 139 third wiring 140 further photodetector module
[0079] 142 further photodiode section
[0080] 144 further scintillator
[0081] 148 further anti-scatter element 149 further wiring
Claims
CLAIMS1. A photodetector (10) comprising: a carrier (100) ; a first photodetector module (110) , and a second photodetector module (120) , the first photodetector module (110) comprising a first photodiode section (112) and a first scintillator (114) arranged over the first photodiode section (112) , the first photodiode section (112) comprising a first array (115) of photodiodes (117) and a first peripheral portion (116) , the second photodetector module (120) comprising a second photodiode section (122) and a second scintillator (124) arranged over the second photodiode section (122) , the second photodiode section (122) comprising a second array (125) of photodiodes (117) and a second peripheral portion (126) , wherein the first and the second photodetector modules (110, 120) are attached to the carrier (100) so that a distance from a first main surface (101) of the carrier (100) to the second photodiode section (122) is larger than the distance from the first main surface (101) of the carrier (100) to the first photodiode section (112) and a portion of the second photodetector module (120) overlaps the first peripheral portion (116) .
2. The photodetector (10) according to claim 1, wherein a portion of the second photodiode section (122) overlaps the first peripheral portion (116) .
3. The photodetector (10) according to claim 1 or 2, wherein the first scintillator (114) is arranged over the first array (115) of photodiodes (117) and the first scintillator (114) is absent from the first peripheral portion (116) .
4. The photodetector (10) according to any of the preceding claims, wherein the second photodetector module (120) further comprises a holder (127) arranged between the carrier (100) and the second photodiode section (122) .
5. The photodetector (10) according to claim 4, wherein a gap (121) is formed in a surface of the holder (127) remote from the second photodiode section (122) .
6. The photodetector (10) according to claim 4 or 5, wherein a surface of the holder (127) supporting the second photodiode section (122) is inclined with respect to a plane parallel to the first main surface (101) of the carrier (100) .
7. The photodetector (10) according to any of the preceding claims, wherein a pitch of first photodiodes (117) of the first array (115) of photodiodes (117) is different from the pitch of second photodiodes (117) of the second array (125) of photodiodes .
8. The photodetector (10) according to any of the preceding claims, further comprising a third photodetector module (130) comprising a third photodiode section (132) and a third scintillator (134) arranged over the third photodiode section (132) , the third photodiode section (132) comprising a third array of photodiodes and a third peripheral portion, wherein the third photodetector module (130) is attached to the carrier (100) so that a distance from a first main surface (101) of the carrier (100) to the third photodiode section (132) is larger than the distance from the first main surface (101) of the carrier (100) to the second photodiode section (122) and a portion of the third photodiode section (132) overlaps the second peripheral portion (126) .
9. A computer tomography system (25) comprising: a radiation source (20) ; and the photodetector (10) according to any of the preceding claims .
Citation Information
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