JP2012018074A - Radiation detector and manufacturing method thereof - Google Patents

Abstract

Provided is an X-ray detector which suppresses interface peeling of a protective layer and ensures various characteristics and reliability.
The solid-state imaging device 12 includes a light receiving portion 14 in which a plurality of photoelectric conversion elements 13 are arranged on the surface side, and an electrode pad 16 electrically connected to the photoelectric conversion elements 13. It has a scintillator layer 26 that opposes the light receiving portion 14 of the solid-state imaging device 12 and converts X-rays 24 incident from the outside into light. An external connection electrode pad 18 and an electrode terminal 19 electrically connected to the external connection electrode pad 18 are provided, and a base 17 for fixing the solid-state imaging device 12 is provided. A wiring 20 is provided for electrically connecting the electrode pads 16 and 18. An intermediate layer 22 is formed of an organic silicon compound on the solid-state imaging device 12, the electrode pad 16, the external connection electrode pad 18, and the wiring 20. A protective layer 28 is formed on the intermediate layer 22 with an organic material.
[Selection] Figure 1

Description

  Embodiments described herein relate generally to a radiation detector including a solid-state imaging device and a method for manufacturing the same.

  As a new-generation X-ray diagnostic image detector, an X-ray detector, which is a planar radiation detector using an active matrix or a solid-state imaging device such as a CCD or CMOS, has been attracting attention. By irradiating the planar X-ray detector with X-rays, an X-ray image or a real-time X-ray image is output as a digital signal. Since this X-ray detector is a solid state detector, it is highly expected in terms of image quality performance and stability, and a lot of research and development is being conducted.

  Main applications of X-ray detectors using an active matrix have been developed for general radiography for chests that collect still images with a relatively large dose, and have recently been commercialized. Commercialization is also progressing for applications in the fields of circulatory organs and digestive organs that need to realize higher-performance, real-time moving images of 30 frames per second or more under fluoroscopic dose. For this video application, improvement of S / N ratio, real-time processing technology of minute signals, and the like are important development items.

  In addition, X-ray detectors using solid-state imaging devices such as CCD and CMOS are mainly used for industrial non-destructive inspection that collects still images with a large dose, and to collect still images by insertion into the oral cavity. Dental products have been commercialized in recent years. In this X-ray detector, including development for video applications, improvement of S / N ratio, real-time processing of minute signals, miniaturization of X-ray detector, improvement of reliability, etc. are important development items. Yes.

  By the way, X-ray detectors are roughly classified into two methods, a direct method and an indirect method.

  The direct method is a method in which X-rays are directly converted into a charge signal by a photoconductive film such as a-Se and led to a charge storage capacitor. Since this direct X-ray detector guides photoconductive charges generated by X-rays directly to a charge storage capacitor by a high electric field, a resolution characteristic substantially defined by the pixel electrode pitch of the active matrix can be obtained.

  On the other hand, the indirect method is a method in which X-rays are once converted into visible light by the scintillator layer, and the visible light is converted into signal charges by an a-Si photodiode, CCD, CMOS or the like and led to the charge storage capacitor. For this reason, in the indirect X-ray detector, resolution characteristics are degraded due to optical diffusion and scattering until the visible light from the scintillator layer reaches the photodiode, CCD, and CMOS.

  In general, an indirect X-ray detector using a solid-state image sensor has a light-receiving unit in which a plurality of photoelectric conversion elements are arranged on a solid-state image sensor that is a detector unit, and is located outside the light-receiving unit. An electrode pad electrically connected to the photoelectric conversion element is formed. A scintillator layer is formed on the light-receiving portion of the solid-state image sensor, and the solid-state image sensor has an electrode pad for external connection and an electrode terminal electrically connected to the electrode pad for external connection. It is fixed to. Furthermore, the electrode pad on the solid-state image sensor and the electrode pad for external connection on the base are electrically connected by wiring.

  As another configuration, a detector unit in which a scintillator panel having a scintillator layer on a support substrate that transmits radiation is formed on a light-receiving unit of a solid-state image sensor via a bonding layer is provided as an electrode pad for external connection. And there exists the structure fixed on the base which has an electrode terminal electrically connected with this electrode pad for external connection.

  Then, visible light converted by the scintillator layer by incident X-rays is converted into electric charges by reaching a photoelectric conversion element formed on the solid-state imaging element, and this electric charge is accumulated in the photoconductive conversion element for a certain period of time. Accumulated charges from the signal line corresponding to each photoelectric conversion element, the electrode pad on the solid-state image sensor corresponding to each photoelectric conversion element, the electrode pad on the solid-state image sensor corresponding to each photoelectric conversion element, wiring, and Then, via the external connection electrode pad on the base, it is sequentially read out as an output signal from each electrode terminal formed on the base, and converted into a digital image signal by a predetermined signal processing circuit or the like.

  Further, in the X-ray detector as described above, in order to increase the utilization efficiency of visible light converted by the scintillator layer, a reflective layer is formed on the scintillator layer or a support substrate constituting the scintillator panel, and the reliability is improved. Protective cover through a protective layer and a bonding layer mainly made of a resin material for electrode pads on the solid-state image sensor, electrode pads for external connection on the base, and wiring for electrically connecting these pads to improve the performance. May form. In the case of such a configuration, absorption of incident X-rays in the support substrate (deterioration of output signal intensity with respect to incident X-rays), expansion of the X-ray detector size by introduction of the support substrate, the number of parts (support substrate) and the number of processes ( There are effects such as productivity deterioration due to an increase in bonding layer formation), optical diffusion and scattering (degradation of image characteristics) in the bonding layer, and the like.

  Therefore, in the X-ray detector as described above, the characteristics of the scintillator layer are important in terms of structure in order to achieve higher performance, smaller size, improved reliability, and improved productivity. In order to improve the strength, for example, a scintillator layer is often made of a high-intensity fluorescent material composed of a halogen compound such as CsI or an oxide compound such as GOS. In particular, a halogen compound such as CsI is used. When used in a scintillator layer, resolution characteristics may be improved by forming a scintillator layer having a strip-like columnar crystal structure using a vacuum deposition method.

  Furthermore, when a halogen compound such as CsI is used for the scintillator layer, the X-ray detector can be trusted by forming a scintillator protective layer on the scintillator layer so that the scintillator layer does not deliquefy by reacting with moisture in the atmosphere. Sometimes it is possible to ensure sex.

JP 2007-303875 A

  However, when halogen compounds such as CsI are used for the scintillator layer, the reactivity of halogen elements such as iodine is high, so the photoelectric conversion element that comes into contact with the scintillator layer, the electrode pad on the solid-state image sensor, and the external connection on the base There is a risk that corrosion will occur due to reaction with positive electrode in the electrode pads for wiring and wirings electrically connecting these pads. For this reason, there are problems in that various characteristics and reliability of the X-ray detector are deteriorated, productivity is lowered, and production cost is increased.

  Furthermore, in order to ensure reliability, the electrode pad on the solid-state image sensor, the electrode pad for external connection on the base, the electrode pad on the solid-state image sensor, and the wiring that electrically connects these pads are mainly made of a resin material. It is essential to form a protective layer composed of However, in this case, since it is necessary to secure a clearance associated with the formation of the protective layer between the light receiving unit of the solid-state imaging device and the electrode pad on the solid-state imaging device, the X-ray detector can be downsized or the light receiving unit In addition, since the protective layer is mainly composed of a resin material, the X-ray absorptance is lower than that of the scintillator layer, resulting in a problem that leads to a decrease in reliability associated with X-ray resistance.

  Therefore, when a halogen compound such as CsI is used for the scintillator layer, as described in Patent Document 1, for example, at least a solid-state imaging device, an electrode pad on the solid-state imaging device, and an external connection electrode on the base The pad and the wiring that electrically connects these pads are made of the same organic material or inorganic material that has insulating properties, water vapor barrier properties, permeability of the scintillator layer to light emission, and corrosion resistance to the material constituting the scintillator layer. A solid-state imaging device having a structure continuously covered with a protective layer formed thereon, and an electrode pad on the solid-state imaging device, an electrode pad for external connection on the base, and these pads electrically By forming a scintillator layer on the wiring to be connected, the performance of the radiation detector is improved, the size is reduced, and the reliability is improved. Production improvement and production cost reduction can be achieved.

  For this reason, in this configuration, the physical properties and functions of the protective layer are important. Particularly, as the protective layer, the corrosion resistance, the insulating property, the water vapor blocking property, the optical transparency are high, and the film thickness is increased. It is most effective when an organic film (for example, polyparaxylylene) that is easy and hardly causes film defects (such as pinholes) is formed by a vapor phase growth method such as a CVD method having high conformity and uniformity.

  However, in such a configuration of the X-ray detector, when an organic film is formed as a protective layer by a vapor deposition method such as CVD, generally, the organic film is firmly bonded to a metal surface or an oxide surface. In many cases, a solid-state imaging device composed of a protective layer, a metal and an oxide, an electrode pad on the solid-state imaging device, an electrode pad for external connection on the base, and these pads are electrically connected. Since the coupling strength with the wiring to be connected is very weak, the interface layer may be peeled off when the thermal stress or external force is applied to the X-ray detector. Leads to deterioration of various characteristics and reliability.

  This invention is made | formed in view of such a point, and it aims at providing the radiation detector which suppressed the interface peeling of the protective layer, and ensured various characteristics and reliability, and its manufacturing method.

  The radiation detector according to the embodiment includes a solid-state imaging device including a light receiving unit in which a plurality of photoelectric conversion elements are arranged on the surface side, and an electrode pad electrically connected to the photoelectric conversion elements. The radiation detector has a scintillator layer that converts X-rays incident from the outside facing the light receiving portion of the solid-state imaging device into light. Further, the radiation detector includes an external connection electrode pad and an electrode terminal electrically connected to the external connection electrode pad, and has a base for fixing the solid-state imaging device. Further, the radiation detector has wiring for electrically connecting the electrode pad on the solid-state imaging device and the external connection electrode pad on the base. Furthermore, the radiation detector has an intermediate layer formed of an organic silicon compound on at least a solid-state imaging device, an electrode pad on the solid-state imaging device, an external connection electrode pad on a base, and a wiring. The radiation detector has a protective layer at least partially formed of an organic substance on the intermediate layer.

  In addition, the radiation detector manufacturing method of the embodiment includes at least a solid-state imaging device, an electrode pad on the solid-state imaging device, an electrode pad for external connection on the base, an electrode pad on the solid-state imaging device, and a wiring. An intermediate layer forming step of forming an intermediate layer by a physical vapor deposition method using a silicon compound; Furthermore, the manufacturing method of a radiation detector has a protective layer formation process which forms at least one part of a protective layer by vapor phase epitaxy using this organic substance on this intermediate layer after forming an intermediate layer.

It is sectional drawing which shows the radiation detector of 1st Embodiment. It is explanatory drawing which shows the chemical structure of the organosilicon compound used for the intermediate | middle layer of a radiation detector same as the above. It is explanatory drawing which shows the effect | action image of an organosilicon compound same as the above. It is explanatory drawing which shows the reaction mechanism (a hydrolysis reaction and a condensation reaction are included) of an organosilicon compound and an inorganic surface same as the above. It is explanatory drawing which shows the surface activation process of the manufacturing method of a radiation detector same as the above. It is explanatory drawing which shows the film formation process by the physical vapor deposition of the manufacturing method of a radiation detector same as the above. It is explanatory drawing which shows the drying process of the manufacturing method of a radiation detector same as the above. It is sectional drawing which shows the radiation detector of 2nd Embodiment. It is sectional drawing which shows the radiation detector of a prior art example. It is sectional drawing which shows the radiation detector of another prior art example. It is a table | surface which shows the result of the comparison experiment of the image characteristic of each conventional example and each Example. It is a table | surface which shows the residual rate of the protective layer after the crosscut test of each conventional example and each Example. It is a table | surface which shows the result of the comparative experiment of the image characteristic after the thermal shock test of each conventional example and each comparative example.

  The configuration of the embodiment will be described below with reference to the drawings.

  FIG. 1 shows a first embodiment.

  11 is an X-ray detector as a radiation detector, and this X-ray detector 11 is an indirect X-ray plane image detector. The X-ray detector 11 includes a solid-state imaging device 12 that is a photoelectric conversion substrate that converts visible light L into an electrical signal.

  In the central area of the surface of the solid-state imaging device 12, a light receiving section 14 is formed in which at least a plurality of photoelectric conversion elements 13 such as photodiodes that convert visible light L into electric signals are arranged one-dimensionally or two-dimensionally. Has been. In addition, a plurality of electrode pads 16 that are electrically connected to the respective photoelectric conversion elements 13 and extract electric signals converted by the respective photoelectric conversion elements 13 are arranged in the peripheral area of the surface of the solid-state imaging element 12. The solid-state image sensor 12 is fixed to the base 17. A plurality of external connection electrode pads 18 that are electrically connected to the electrode pads 16 on the solid-state imaging device 12 are arranged on the front surface side of the base 17, and the external surfaces are arranged on the back side of the base 17. A plurality of external connection electrode terminals 19 that are electrically connected to the connection electrode pads 18 are arranged.

  Each electrode pad 16 of the solid-state imaging device 12 and each external connection electrode pad 18 of the base 17 are electrically connected by a plurality of wires 20 such as wires. Further, the entire surface of the base 17 including the light receiving portion 14 and the electrode pad 16 of the solid-state imaging device 12 disposed on the surface side of the base 17, the external connection electrode pad 18 and the wiring 20 forms the intermediate layer 22. The first protective layer 23 is continuously and integrally protected.

  Further, on the base 17 including the surface side of the first protective layer 23 on the solid-state imaging device 12, a scintillator layer 26 that converts X-rays 24 as radiation incident from the outside into visible light L is provided in the light receiving unit 14. It is formed in the position which opposes. For this scintillator layer 26, a phosphor such as a halogen compound such as cesium iodide (CsI) or an oxide compound such as gadolinium sulfate (GOS), which is a high-intensity fluorescent material, is used. Or a vapor phase growth method such as a CVD method. Further, the second protective layer 27 is formed integrally with the first protective layer 23 by covering the scintillator layer 26 with the same material as the first protective layer 23 and by the same formation method. The first protective layer 23 and the second protective layer 27 constitute a protective layer 28.

  Here, the protective layer 28 is made of an organic material having an insulating property, a water vapor blocking property, a light-transmitting property of the scintillator layer 26, and a corrosion resistance to a material constituting the scintillator layer 26. The electrode pad 16 on the solid-state image pickup device 12, the external connection electrode pad 18 on the base 17, and the wiring 20 are continuously covered, and the scintillator layer 26 is sealed. In addition, as a process for forming the protective layer 28 (protective layer forming step), it is preferable to use a vapor phase growth method such as a CVD method in consideration of shape matching and uniformity.

  A bonding layer 31 is formed at the end of the base 17, and a protective cover 32 for protecting the solid-state imaging device 12 and the scintillator layer 26 is formed through the bonding layer 31.

  The intermediate layer 22 includes at least an organic functional group of amino group, epoxy group, sulfado group, vinyl group, allyl group, methacryl group, mercapto group, ketimino group, methoxy group, ethoxy group, acetoxy group, isopropoxy group. These are formed from an organosilicon compound having any hydrolyzable group. The intermediate layer 22 is formed on at least the solid-state image sensor 12, the electrode pad 16 on the solid-state image sensor 12, the external connection electrode pad 18 on the base 17, and the wiring 20, for example, by physical vapor deposition, Formed by hydrolysis and condensation reactions.

  Next, the chemical structure and action image of the organosilicon compound forming the intermediate layer 22, the reaction mechanism between the organosilicon compound and the inorganic surface, and the outline of the formation process of the intermediate layer 22 are shown in FIGS.

  As shown in FIGS. 2 to 4, the organosilicon compound forming the intermediate layer 22 is composed of an organic functional group (A) that causes a reaction or interaction with an organic substance as a chemical structure, and an inorganic substance by a hydrolysis reaction and a condensation reaction. And a hydrolyzable group (OB) that forms a covalent bond. For this reason, the hydrolyzable group (OB) of the organosilicon compound is hydrolyzed by moisture to form a silanol group, then transferred to the inorganic surface through hydroxyl groups and hydrogen bonds present on the inorganic surface, and further through a dehydration condensation reaction. Organic functional group (A) that forms a strong covalent bond with the inorganic surface and causes reaction or interaction with the organic material (reaction with a functional group in the organic material, graft reaction, copolymerization, compatibilization, etc.) Therefore, even in the order of several atomic layers (several tens to several tens of centimeters), it becomes possible to firmly bond organic substances and inorganic substances having different chemical properties.

  Further, as shown in FIG. 2 and FIG. 4, from the chemical structure of the organosilicon compound forming the intermediate layer 22 and the reaction mechanism with the inorganic surface, the optical influence (deterioration factor of image characteristics) due to the formation of the intermediate layer 22 In order to avoid this, an organic silicon compound is uniformly thinned on at least the solid-state image sensor 12, the electrode pad 16 on the solid-state image sensor 12, the external connection electrode pad 18 on the base 17, and the wiring 20. Need to form. Therefore, as a process for forming the intermediate layer 22 (intermediate layer forming step), a dipping method using a solution containing an organosilicon compound, a spray method, a spin coating method, and the like are possible. For example, FIG. 5 to FIG. It is preferable to form by the method shown.

That is, first, as shown in FIG. 5, at least a solid-state image sensor of the intermediate body M in which the solid-state image sensor 12 and the wiring 20 are formed on the base 17 disposed on the support jig J1 in the cleaning processing chamber C1. 12. Generation of ozone O from oxygen in the atmosphere by ultraviolet UV from the ultraviolet lamp UL for the electrode pad 16 on the solid-state imaging device 12, the electrode pad 18 for external connection on the base 17, and the wiring 20 And surface activation (UV-O ₃ cleaning treatment, etc.) by causing a decomposition process. Next, masking MA is applied to the non-formation area of the intermediate layer 22 of the intermediate M, and as shown in FIG. 6, the intermediate M arranged on the support jig J2 in the closed processing chamber C2 is sealed in the closed processing chamber. A film ME serving as the intermediate layer 22 is formed by exposure (vapor deposition method) in a saturated atmosphere A1 of the solution S containing the organosilicon compound in C2. Then, after removing the masking MA, as shown in FIG. 7, an intermediate M is placed on the support jig J3 in the drying processing chamber C3, and the atmosphere A2 containing moisture H in the drying processing chamber C3 is disposed. The method in which the coating ME is made into the intermediate layer 22 by performing a drying treatment with infrared IR from the lamp heater LH has a high shape conformity and uniformity of the intermediate layer 22 and is thin (about several atomic layers). It is most effective because it is easy. Thereafter, a first protective layer 23 (protective layer 28) is formed on the intermediate layer 22 by vapor deposition.

  For this reason, as shown in FIG. 1, at least the solid-state imaging device 12, the electrode pad 16 on the solid-state imaging device 12, the external connection electrode pad 18 on the base 17, and the wiring 20 are at least an amino group, an epoxy Group, sulfado group, vinyl group, allyl group, methacryl group, mercapto group, ketimino group and any functional group of methoxy group, ethoxy group, acetoxy group, isopropoxy group Through the intermediate layer 22 formed from an organosilicon compound, a protective layer made of an organic material having insulating properties, water vapor blocking properties, permeability to the light emitted from the scintillator layer 26, and corrosion resistance to the substances constituting the scintillator layer 26 When the structure is continuously covered with 28, even when thermal stress or external force is applied to the X-ray planar image detector, the interface peeling of the protective layer 28 (first protective layer 23) is performed. It is possible to prevent a, it is possible to improve the characteristics and reliability.

  Furthermore, the intermediate layer 22 is capable of firmly bonding an organic substance and an inorganic substance having different chemical properties even with a thickness of several atomic layers (several tens to several tens of centimeters) which is a film thickness that does not cause an optical influence from the chemical structure. Therefore, even if the intermediate layer 22 is formed on the solid-state image sensor 12, there is no effect on the image characteristics. Therefore, the X-ray detector 11 has higher performance, smaller size, improved reliability, and productivity. Improvement and production cost reduction are possible.

  Next, a second embodiment will be described with reference to FIG.

  In the second embodiment, a reflective layer 35 is formed on the surface of the scintillator layer 26 of the first embodiment except that a reflective layer 35 for increasing the utilization efficiency of the visible light L converted by the scintillator layer 26 is formed. The configuration is the same as that of the X-ray detector 11 of the first embodiment.

  In the second embodiment, in addition to the same effects as those of the first embodiment, the use efficiency of the visible light L converted by the scintillator layer 26 can be further increased by the reflective layer 35. .

  That is, according to each of the embodiments described above, the solid-state imaging device 12, the electrode pad 16 on the solid-state imaging device 12, the external connection electrode pad 18 on the base 17 and the wiring 20 are interleaved with an organic silicon compound. The layer 22 is formed, and the protective layer 28 (first protective layer 23) is formed on the intermediate layer 22 with an organic material, whereby the intermediate layer 22 forms a protective layer 28 that is an organic material, a solid-state imaging device 12 that is an inorganic material, and an electrode Since the pad 16, the external connection electrode pad 18 and the wiring 20 can be firmly bonded, the interface peeling of the protective layer 28 can be suppressed, and various characteristics and reliability can be secured.

  Although the X-ray detector 11 for detecting the X-rays 24 has been described, the present invention can be similarly applied to a radiation detector for detecting other radiation.

  Next, examples will be described.

  Considering Comparative Example 1 shown in FIG. 9 corresponding to the prior art, Comparative Example 2 shown in FIG. 10, and Example 1 and Example 2 corresponding to the first and second embodiments. About a comparative example, the same code | symbol shall be used for the structure of the same name as the said 1st Embodiment.

  In the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. 8, for example, the solid-state imaging device 12 is CMOS, the electrode pad 16 is made of Al, the base 17 is made of ceramic, the external connection electrode pad 18 is made of The wiring 20 is made of Au, the organic silicon compound constituting the intermediate layer 22 is vinyltrimethoxysilane, the formation process of the intermediate layer 22 is shown in FIGS. 5 to 7, and the constituent material of the protective layer 28 is polyparaxylline. The protective layer 28 has a film thickness of 5 μm, the scintillator layer 26 has a high-luminance fluorescent material CsI (Tl doped), the protective cover 32 is made of Al, and the bonding layer 31 is made of an epoxy resin.

  In Comparative Example 1 shown in FIG. 9 and Comparative Example 2 shown in FIG. 10, for example, the solid-state imaging device 12 is CMOS, the electrode pad 16 is made of Al, the base 17 is made of ceramic, the external connection electrode pads 18 and The material of the wiring 20 is Au, the constituent material of the protective layer 28 is polyparaxylylene, the thickness of the protective layer 28 is 5 μm, the high brightness fluorescent material of the scintillator layer 26 is CsI (Tl doped), and the material of the protective cover 32 is Al. The constituent material of the bonding layer 31 is an epoxy resin.

  At this time, in each embodiment, at least the solid-state imaging device 12, the electrode pad 16 on the solid-state imaging device 12, the external connection electrode pad 18 on the base 17, and the wiring 20 are formed from the organosilicon compound. Since the structure is continuously covered with a protective layer 28 (first protective layer 23) made of an organic substance through the intermediate layer 22, the solid-state imaging device 12 made of the protective layer 28 and a metal and an oxide, Since the bond strength between the electrode pad 16 on the solid-state imaging device 12, the electrode pad 18 for external connection on the base 17, and the wiring 20 is strengthened, thermal stress or external force is applied to the X-ray detector 11. Even in such a case, since the interface peeling of the protective layer 28 can be prevented, various characteristics and reliability can be improved.

  Furthermore, the intermediate layer 22 is capable of firmly bonding an organic substance and an inorganic substance having different chemical properties even with a thickness of several atomic layers (several tens to several tens of centimeters) which is a film thickness that does not cause an optical influence from the chemical structure. Therefore, even if the intermediate layer 22 is formed on the solid-state imaging device 12, the image characteristics are not affected. For this reason, the X-ray detector 11 can be improved in performance, reduced in size, improved in reliability, improved in productivity, and reduced in production cost.

  Moreover, the result of having implemented the characteristic comparison (an image characteristic, a crosscut test, a thermal shock test) with each Example and each comparative example is shown in FIG. 11 thru | or FIG.

  First, sensitivity and resolution (MTF) were measured under the same conditions (tube voltage: 60 kV, tube current: 0.4 mA, SID: 300 mm, X-ray irradiation time: 0.1 s). FIG. 11 shows the result of obtaining the ratio in the case of the above.

  From the results of FIG. 11, it was found that the image characteristics of the X-ray detector 11 of each example were equivalent to the image characteristics of the X-ray detector 11a of each comparative example.

  In addition, the cross-cut test of each example and each comparative example is performed under the same conditions (test condition A: using a 5 N / 25 mm adhesive tape, test condition B: using a 10 N / 25 mm adhesive tape). went. The test method conformed to JIS K5600, and the test site was a protective layer 28 (first protective layer 23) formed on the solid-state imaging device 12. The ratio of the protective layer 28 (first protective layer 23) remaining on the solid-state imaging device 12 after this cross-cut test was taken as the film remaining rate.

  As shown in FIG. 12, in the X-ray detector 11 of each example, 100% of the protective layer 28 remained even after the cross-cut test, whereas in the X-ray detector 11a of each comparative example, the cross-cut After the test, the remaining rate of the film decreased in each of the test conditions A and B. From this result, it was found that the X-ray detector 11 of each example can effectively prevent the interface peeling of the protective layer 28 (first protective layer 23) compared to the X-ray detector 11a of each comparative example. did.

  Furthermore, the thermal shock test of each Example and each comparative example was done. As a test method, a temperature cycle (no RT holding) between a low temperature part (temperature condition: −30 ° C. (holding time: 30 min)) and a high temperature part (temperature condition: 70 ° C. (holding time: 30 min)). Applied to the protective layer 28 (first protective layer 23) under the same conditions (tube voltage: 60 kV, tube current: 0.4 mA, SID: 300 mm, X-ray irradiation time: 0.1 s) The presence or absence of deterioration (sensitivity / resolution) was evaluated.

  As shown in FIG. 13, in the X-ray detector 11 of each example, the image was not affected even after 50 cycles and after 100 cycles, whereas in the X-ray detector 11a of each comparative example, The effect on the image was also observed after 50 cycles, and after 100 cycles, the effect on the image increased more than at 50 cycles. From this result, the X-ray detector 11 of each example is less likely to cause interface peeling of the protective layer 28 (first protective layer 23) against thermal shock as compared to the X-ray detector 11a of each comparative example. It has been found.

  From these comparative experiments, in each example corresponding to each of the above-described embodiments, improvement in characteristics is observed with respect to each conventional example corresponding to each conventional technique. Therefore, various characteristics and reliability of the X-ray detector 11 are observed. It can be said that the effect on improvement is clear.

  For example, in the configuration of the embodiment shown in FIG. 1, the constituent material of the protective layer 28 (first protective layer 23) is polyparaxylylene, and the organosilicon compound constituting the intermediate layer 22 is vinyltriethoxysilane, Vinyltriacetoxysilane, vinyltriisopropoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3- Glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, allyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3 -Mercaptopropyl Even triethoxysilane, etc., the same effect as the case where the organosilicon compound constituting the intermediate layer 22 was vinyltrimethoxysilane is obtained.

11 X-ray detectors as radiation detectors
12 Solid-state image sensor
13 Photoelectric conversion element
14 Receiver
16 electrode pads
17 base
18 External connection electrode pads
19 Electrode terminal
20 Wiring
22 Middle layer
24 X-rays as radiation
26 Scintillator layer
28 Protective layer

Claims (8)

A light receiving unit in which a plurality of photoelectric conversion elements are arranged on the surface side, and a solid-state imaging device including an electrode pad electrically connected to the photoelectric conversion element;
A scintillator layer that converts the radiation incident from the outside facing the light receiving portion of the solid-state imaging device into light;
An external connection electrode pad and an electrode terminal electrically connected to the external connection electrode pad, and a base for fixing the solid-state imaging device;
Wiring for electrically connecting the electrode pads on the solid-state imaging device and the external connection electrode pads on the base;
At least the solid-state imaging device, the electrode pad on the solid-state imaging device, the external connection electrode pad on the base and the wiring, and an intermediate layer formed of an organosilicon compound;
A radiation detector comprising: a protective layer formed of an organic material on at least a part of the intermediate layer. The organosilicon compound forming the intermediate layer is
At least an organic functional group of any one of amino group, epoxy group, sulfado group, vinyl group, allyl group, methacryl group, mercapto group and ketimino group,
The radiation detector according to claim 1, further comprising a hydrolyzable group of any one of a methoxy group, an ethoxy group, an acetoxy group, and an isopropoxy group. The radiation according to claim 1 or 2, wherein the protective layer has insulating properties, water vapor barrier properties, transparency to light emission of the scintillator layer, and corrosion resistance to a substance constituting the scintillator layer. Detector. The radiation detector according to any one of claims 1 to 3, wherein the protective layer is formed of an organic substance mainly composed of polyparaxylylene. The radiation detector according to any one of claims 1 to 4, wherein the scintillator layer is made of a high-intensity fluorescent material containing at least a halogen compound. The radiation detector according to any one of claims 1 to 5, wherein the scintillator layer is continuously covered with a protective layer and sealed with the protective layer. A light receiving unit in which a plurality of photoelectric conversion elements are arranged on the front surface side, a solid-state imaging device including an electrode pad electrically connected to the photoelectric conversion element, and the light receiving unit of the solid-state imaging element. A scintillator layer for converting radiation incident from the outside into light, an electrode pad for external connection and an electrode terminal electrically connected to the electrode pad for external connection, and a base for fixing the solid-state imaging device; A method of manufacturing a radiation detector comprising: the electrode pad on the solid-state imaging device; and the wiring for electrically connecting the electrode pad for external connection on the base,
At least the solid-state imaging device, the electrode pad on the solid-state imaging device, the external connection electrode pad on the base, the electrode pad on the solid-state imaging device, and the wiring are formed with an intermediate layer using an organosilicon compound. An intermediate layer forming step formed by physical vapor deposition;
And a protective layer forming step of forming at least a part of the protective layer on the intermediate layer by vapor phase epitaxy using an organic substance after the intermediate layer is formed. Production method. The intermediate layer forming step includes at least an organic functional group of amino group, epoxy group, sulfado group, vinyl group, allyl group, methacryl group, mercapto group and ketimino group, and methoxy group, ethoxy group, acetoxy group, After forming an organosilicon compound having a hydrolyzable group of propoxy group on at least a solid-state imaging device, an electrode pad on the solid-state imaging device, an external connection electrode pad on the base and a wiring by physical vapor deposition, The method for producing a radiation detector according to claim 7, further comprising a step of forming an intermediate layer of the organosilicon compound by a hydrolysis reaction and a condensation reaction.

Images