Radiation sensor element and method

Abstract

A radiation sensor element (100) includes a support plate (160) having a front face (161) that extends substantially along a base plane (120) defining a lateral extent of the radiation sensor element (100); a substrate (110) having a base face (111), an interconnect face (112) opposite the base face (111), and an edge face (113) connecting the base face (111) and the interconnect face (112); a sensor block (130) having a back face (136) facing the interconnect face (112); a copper pillar interconnect element (140) between the interconnect face (112) and the back face (136); and a non-conductive film (150) extending between the interconnect face (112) and the back face (136). The front face (161) includes a recess (162) that laterally extends beyond the edge face (113) and extends in a thickness direction perpendicular to the base plane (120), and the non-conductive film (150) includes an edge protruding portion (151) extending in the recess (162).

Description

Technical Field

[0001] The present invention relates to radiation detector technology. In particular, the present invention relates to the back-end processing of radiation detectors.

[0002] Background

[0003] Radiation detectors are widely used to detect ionizing radiation in experimental and applied particle and nuclear physics, as well as in medical and environmental fields. For example, radiation detectors can also be used in various security and military applications.

[0004] One of the most advantageous types of radiation detectors is the so-called solid-state detector, i.e., a semiconductor detector. Compared to other types of radiation sensors, such detectors generally offer improved ease of use, longer lifetime, smaller size, as well as higher resolution and sensitivity.

[0005] However, back-end processing can be challenging for solid-state sensor elements. For example, these challenges may be related to the high-resolution and layout density levels required by modern devices. In view of this, it may be desirable to develop new solutions related to the back-end processing of solid-state sensor elements.

[0006] Overview

[0007] This overview is provided to introduce a series of concepts in a simplified form that are further described below in the detailed description. This overview is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0008] According to a first aspect, a radiation sensor element is provided. The radiation sensor element includes a support plate having a front face that extends substantially along a base plane that defines a lateral extent of the radiation sensor element; a substrate having a basal face facing the front face, an interconnect face opposite the basal face, and an edge face connecting the basal face and the interconnect face; a sensor tile that includes an active material layer and has a back face facing the interconnect face; copper pillar interconnect elements between the interconnect face and the back face; and a non-conductive film that extends between the interconnect face and the back face and laterally surrounds the copper pillar interconnect elements.

[0009] The front face includes a depression that extends in a thickness direction perpendicular to the base plane and laterally extends beyond the edge face; and the non-conductive film includes an edge protrusion that extends in the depression and laterally extends beyond the edge face.

[0010] According to a second aspect, a method for manufacturing a radiation sensor element is provided. The method includes providing a support plate having a front face that extends substantially along a base plane, the base plane defining a lateral extent of the radiation sensor element, the front face including a recess extending in a thickness direction perpendicular to the base plane; providing a substrate having a base face, an interconnect face opposite the base face, and an edge face connecting the base face and the interconnect face; providing a sensor block including an active material layer and having a back face; providing copper pillar interconnect elements; providing a non-conductive film; arranging the support plate and the substrate such that the base face faces the front face and the recess is arranged to laterally extend beyond the edge face; and coupling the sensor block to the substrate such that the back face faces the interconnect face, the non-conductive film extends between the interconnect face and the back face, the copper pillar interconnect elements are arranged between the interconnect face and the back face, and the non-conductive film laterally surrounds the copper pillar interconnect elements, thereby forming an edge protruding portion of the non-conductive film extending in the recess. Brief Description of the Drawings

[0012] The present disclosure will be better understood from the following detailed description read in conjunction with the accompanying drawings, in which:

[0013] Figure 1 A schematic isometric view of a radiation sensor element is depicted,

[0014] Figure 2 A schematic cross-sectional view of the same radiation sensor element along a cross-section extending along the Figure 1 dash-dotted line II-II, and

[0015] Figure 3 A flowchart of a method for manufacturing a radiation sensor element is shown.

[0016] Unless otherwise specifically stated to the contrary, any of the above drawings may not be drawn to scale such that any element in the drawings may be drawn in an inaccurate proportion relative to other elements in the drawings in order to emphasize certain structural aspects of the embodiments of the drawings.

[0017] In addition, in order to emphasize certain structural aspects of the embodiments of the two drawings, corresponding elements in the embodiments of any two of the foregoing drawings may not be commensurate with each other in the two drawings.

[0018] Detailed Description

[0019] Regarding the radiation sensor element and method discussed in this detailed description, the following points should be noted.

[0020] In this context, "radiation" should be understood broadly to include, for example, electromagnetic radiation and particle radiation. Radiation can generally correspond to ionizing radiation or non-ionizing radiation.

[0021] In this specification, "ionizing" radiation can refer to radiation where the particle or photon energy is less than 10 electron volts (eV), while "non-ionizing" radiation can refer to radiation where the particle or photon energy is at least 10 eV.

[0022] Throughout the specification, a "radiation detector" can refer to a complete, operable radiation detector. A radiation detector typically can include at least one radiation sensor. A radiation detector can also include other elements, units, and / or structures.

[0023] In this disclosure, a "radiation sensor" can refer to an operable unit, module, or device configured to detect and / or measure radiation and record, indicate, and / or respond to the radiation.

[0024] In addition, a "radiation sensor element" can refer to an element that also forms a radiation sensor. Alternatively, a radiation sensor element can be used as an element of a radiation sensor that also includes other elements and / or structures. A radiation sensor element can include an active material, the physical properties of which are used for the radiation sensor element to record, indicate, and / or respond to radiation incident on the active material. A radiation sensor element can correspond to an indirect conversion radiation sensor element or a direct conversion radiation sensor element.

[0025] Throughout this disclosure, an "indirect conversion radiation sensor element" can refer to a radiation sensor element that includes a scintillator material for converting ionizing radiation into non-ionizing electromagnetic radiation and a semiconductor material as the active material for detecting the electromagnetic radiation emitted by the scintillator.

[0026] In this context, a "semiconductor" material can refer to a material having a conductivity intermediate between that of a conductive material such as a metal and that of an insulating material such as many plastics and glasses. A semiconductor material typically can have a doping level, which can be adjusted to controllably regulate the properties of the semiconductor material.

[0027] In contrast, a "direct conversion radiation sensor element" can refer to a radiation sensor element that does not require the use of a scintillator to convert ionizing radiation into non-ionizing electromagnetic radiation to detect the ionizing radiation. Such a direct conversion radiation sensor element can be based on detecting free charge carriers generated within the active material by incident radiation (e.g., ionizing radiation). A direct conversion radiation sensor element typically can include a compound semiconductor material as the active material.

[0028] In this document, "compound semiconductor" may refer to a semiconductor compound comprising at least two different chemical elements. Compound semiconductor materials may correspond to, for example, binary, ternary or quaternary compounds. Some compound semiconductor materials or material systems may exhibit highly tunable properties based on their elemental composition. An example of such a tunable compound semiconductor material system is an alloy of cadmium zinc telluride (CdZnTe), cadmium telluride (CdTe) and zinc telluride (ZnTe).

[0029] Figure 1 and Figure 2 depicts a radiation sensor element 100 according to an embodiment. Specifically, Figure 2 depicts a cross-sectional view of the radiation sensor element 100 along a cross-section that extends along the Figure 1 dash-dotted line II-II. Since Figure 2 depicts a cross-section of the radiation sensor element 100, Figure 2 it does not limit Figure 1 and Figure 2 the shape of the embodiment or any part thereof in any direction that forms an angle with the cross-section extending along the Figure 1 line II-II.

[0030] In Figure 1 and Figure 2 's embodiments, the radiation sensor element 100 includes a support plate 160. Although only a single support plate 160 is depicted in Figure 1 and Figure 2 , the radiation sensor element may generally include any suitable number of support plates.

[0031] In the present disclosure, a "support plate" may refer to a generally plate-shaped body adapted or configured to mechanically strengthen an element or device. Additionally or alternatively, the support plate may act as a frame to which other elements and / or structures may be mounted or fixed. The support plate may generally include metal. A support plate including metal may generally be used as a heat sink and / or radiation shield for other elements and / or structures.

[0032] In Figure 1 and Figure 2 's embodiments, the support plate 160 includes a front face 161 that extends substantially along a base plane 120 that defines the lateral extent of the radiation sensor element 100. In other embodiments, the support plate may generally include such a front face.

[0033] In this document, a "face" may refer to a part of the surface of a body or element. A face may specifically refer to a part or a portion of the surface of a body or element that is visible from a particular viewing direction. A face of a body or element may or may not have a predefined function in the operation of the body or the element.

[0034] Figure 1 and Figure 2 The base plane 120 of the embodiment of [and] is planar. In other embodiments, the support plate may be planar or curved and have a front face that extends substantially along the curved base plane.

[0035] Figure 1 and Figure 2 The support plate 160 of the embodiment of [and] also has a rear face 163 opposite the front face 161. In other embodiments, the support plate 160 may or may not have such a rear face.

[0036] In Figure 1 and Figure 2 In the embodiments of [and], the projection of the support plate 160 on the base plane 120 has a substantially square shape. Generally, such a shape of the support plate can help arrange a plurality of sensor blocks closely adjacent to each other. In other embodiments, the projection of the support plate on the base plane may have any suitable shape, such as a square, rectangle, or other polygon, or a curved shape, such as a circle or an ellipse.

[0037] In Figure 1 and Figure 2 In the embodiments of [and], the radiation sensor element 100 includes a substrate 110. Although only a single substrate 110 is depicted in [and], the radiation sensor element may generally include any suitable number of substrates. Figure 1 and Figure 2 Throughout the specification, a "substrate" may refer to a layer or other element or structure adapted or configured to provide a surface on which other layers or other elements or structures may be bonded, mounted, arranged, deposited, laminated, and / or fabricated. The substrate may include, for example, a semiconductor wafer or die and / or a circuit board.

[0038] In the embodiments of [and], the substrate 110 includes a base surface 111 facing the front face 161. In other embodiments, the substrate may generally have such a base surface.

[0039] In Figure 1 and Figure 2 In the embodiments of [and], the base surface 111 extends substantially along the base plane 120. Further, the base surface is directly connected to the front face 161 of the support plate 160. In other embodiments, the base surface may or may not extend substantially along the base plane. In said other embodiments, the base surface may or may not be directly connected to the front face of the support plate.

[0040] Figure 1 and Figure 2 In the embodiments of [and], the base surface 111 extends substantially along the base plane 120. Additionally, the base surface is directly connected to the front face 161 of the support plate 160. In other embodiments, the base surface may or may not extend substantially along the base plane. In the other embodiments, the base surface may or may not be directly connected to the front face of the support plate.

[0041] Figure 1 andFigure 2 The substrate 110 of the embodiment has an interconnecting surface 112 opposite to the base surface 111. In other embodiments, the substrate generally may have such an interconnecting surface.

[0042] Throughout the specification, an "interconnecting surface" may refer to a surface of a body or element that is configured or adapted to electrically couple the body or element to another body or element. Specifically, the interconnecting surface of the substrate of a radiation sensor element may refer to the surface of the substrate that is configured or adapted to electrically couple the substrate to the active material of the radiation sensor element.

[0043] Figure 1 and Figure 2 The substrate 110 of the embodiment also has an edge surface 113 connecting the base surface 111 and the interconnecting surface 112. In other embodiments, the substrate generally may have such an edge surface.

[0044] As used herein, an "edge surface" may refer to a surface of the substrate that connects the base surface and the interconnecting surface of the substrate. Thus, the edge surface generally may extend from the base surface to the interconnecting surface.

[0045] In Figure 1 and Figure 2 's embodiment, the substrate 110 includes a flexible circuit. Generally, a substrate including a flexible circuit may provide adaptability to height and / or flatness variations during the manufacturing process of a radiation sensor element. Additionally or alternatively, a substrate including a flexible circuit may enable or facilitate increasing the distance between the active material of a radiation sensor element and a circuit adapted or configured to process signals originating from the active material. In other embodiments, the substrate may or may not include a flexible circuit.

[0046] As used herein, a "flexible circuit" may refer to a circuit board that is at least partially flexible, foldable, bendable, pliable, and / or rollable. The flexible circuit may or may not have electrical components attached thereto. The flexible circuit may include, for example, a flat base film, one or more conductor patterns (such as metal patterns) bonded to a surface of the base film, and optionally a thin coating on the conductor patterns for mechanical protection and / or electrical isolation. The flexible circuit may correspond to, for example, a single-sided flexible circuit, a double-sided flexible circuit, a dual-path flexible circuit, a multi-layer flexible circuit, a sculpted flexible circuit, a rigid-flexible circuit, or a polymer thick film flexible circuit.

[0047] Figure 1 and Figure 2 The flexible circuit of the embodiment includes a plurality of conductor traces 114. In other embodiments, where the substrate includes a flexible circuit, the flexible circuit may include one or more conductor traces and / or other types of conductor patterns.

[0048] AlthoughFigure 1 and Figure 2 In the embodiments of Figure 2 , no part of the substrate 110 other than the flexible circuit is depicted in Figure 1 or Figure 2 However, the substrate of the radiation sensor element typically may include any suitable elements in addition to or instead of the flexible circuit.

[0049] In Figure 1 and Figure 2 's embodiments, the radiation sensor element 100 includes a sensor block 130. Although only a single sensor block 130 is depicted in Figure 1 and Figure 2 , the radiation sensor element typically may include any suitable number of sensor blocks.

[0050] As used herein, a "sensor block" may refer to a part of a radiation sensor element that includes an active material. The sensor block may or may not additionally include electronic devices configured to record, process, and / or transmit electrical signals from the active material. The sensor block may or may not have a generally sheet-like form.

[0051] Figure 1 and Figure 2 The sensor block 130 of the embodiments of Figure 2 is arranged on the radiation receiving side of the base plane 120. In other embodiments, the sensor block may or may not be arranged on the radiation receiving side of the base plane.

[0052] Throughout the specification, a "radiation receiving side" may refer to a side of a radiation sensor element or its base plane from which radiation detected by the radiation sensor element may be incident on the radiation sensor element. Additionally or alternatively, the radiation sensor element typically may be configured to detect radiation incident on the radiation sensor element from its radiation receiving side. Additionally or alternatively, the radiation receiving side of the base plane may refer to the side of the base plane on which the sensor block is arranged.

[0053] In Figure 1 and Figure 2 's embodiments, the projection of the sensor block 130 on the base plane 120 has a generally square shape. Generally, multiple sensor blocks having such a shape may be arranged in a four-side dockable manner. In other embodiments, the projection of the sensor block on the base plane may have any suitable shape, such as a square, rectangle, or other polygonal shape, or a curved shape, such as a circular or oval shape.

[0054] As Figure 2 schematically shown, Figure 1 and Figure 2The sensor block 130 of the embodiment includes an active material layer 131. In other embodiments, the sensor block may generally include an active material layer.

[0055] In the present disclosure, a "layer" may refer to a generally sheet-like element disposed on a surface or a body. Additionally or alternatively, a layer may refer to one of a series of superimposed, overlapping, or stacked generally sheet-like elements. A layer may generally include multiple sub-layers of different materials or material compositions. Some layers may be path-connected, while other layers may be locally path-connected and disconnected.

[0056] Thus, an "active material layer" may refer to a layer including the active material of a radiation sensor element. The active material layer may generally include any suitable active material, such as semiconductor materials, such as CdTe, CdZnTe, cadmium manganese telluride (CdMnTe), silicon (Si), germanium (Ge), and / or diamond.

[0057] Figure 1 and Figure 2 The active material layer 131 of the embodiment includes Si as the active material. In other embodiments, the active material layer may include Si and / or any other suitable active material.

[0058] Although omitted from Figure 1 or Figure 2 the active material layer (such as Figure 1 and Figure 2 the active material layer 131 of the embodiment) may be provided with a bias voltage for collecting and / or detecting charges brought by incident radiation. Additionally, some radiation sensor elements may include a scintillator coupled to the active material layer for converting the energy of incident radiation into electromagnetic radiation detectable using the active material layer. In the case of a direct conversion sensor element, such a scintillator may be unnecessary.

[0059] In Figure 1 and Figure 2 the embodiment, the sensor block 130 has a back surface 136 facing the interconnect surface 112 of the substrate 110. In other embodiments, the sensor block may generally have a back surface facing the interconnect surface.

[0060] Throughout the specification, the "back surface" may refer to the surface of the sensor block facing the interconnect surface of the substrate. Additionally or alternatively, the back surface may refer to the surface of the sensor block on the side opposite to the radiation receiving side of the sensor block. Generally, the back surface may or may not include any suitable additional structural features, such as interconnect pads, for implementing or facilitating providing an electrical connection between the sensor block and the substrate.

[0061] In Figure 1 and Figure 2In an embodiment, the sensor block 130 further has a lateral face 137 that extends substantially along the thickness direction from the back face 136. In particular, the lateral face 137 extends from the back face 136 towards the radiation receiving side of the radiation sensor element 100. In other embodiments, the sensor block may or may not include such a lateral face. In embodiments where the sensor block has such a lateral face, the lateral face may extend from the back face towards the radiation receiving side of the radiation sensor element or may not extend from the back face towards the radiation receiving side of the radiation sensor element.

[0062] In the present disclosure, a "lateral face" may refer to a face of the sensor block that extends substantially along the thickness direction of the radiation sensor element from the back face of the sensor block. Additionally or alternatively, a lateral face may refer to a face of the sensor block that extends from its back face towards the radiation receiving side of the radiation sensor element and / or the sensor block.

[0063] Although Figure 1 and Figure 2 the lateral face 137 of the embodiment is depicted as a single surface extending perpendicular to the base plane 120, the lateral face may generally include one or more surfaces, which may be planar, substantially planar, and / or curved.

[0064] Figure 1 and Figure 2 The radiation sensor element 100 of the embodiment includes a plurality of copper pillar interconnect elements 140 between the interconnect face 112 and the back face 136. Such copper pillar interconnect elements may have increased mechanical stiffness, facilitating the penetration of the copper pillar interconnect elements through a viscous material during the manufacturing process of the radiation sensor element. Additionally or alternatively, such increased mechanical stiffness may help control material overflow during the manufacturing process by restricting the advancement of the sensor block towards the substrate during the manufacturing process of the radiation sensor element. In other embodiments, the radiation sensor element may include one or more copper pillar interconnect elements between the interconnect face and the back face.

[0065] As used herein, a "copper pillar interconnect element" may refer to an interconnect element that includes (metallic) copper (Cu) and has a generally cylindrical and / or protruding form. Generally, a copper pillar interconnect element may or may not have a rotationally symmetric shape. Specifically, a copper pillar interconnect element may or may not have a cylindrical shape. A copper pillar interconnect element may have any suitable height in the height direction perpendicular to the interconnect face and / or the back face, for example, a height in the range of a few micrometers to dozens of micrometers. A copper pillar interconnect element may also have any suitable width (e.g., diameter) in the lateral direction perpendicular to the height direction, for example, a width in the range of a few micrometers to dozens of micrometers.

[0066] Copper pillar interconnect elements can generally be provided by any suitable means or process. Thus, the process for providing copper pillar interconnect elements can include, for example, a photolithography step, an electroplating step, and / or an electroless plating step.

[0067] Figure 1 and Figure 2 In embodiments of Figure 2 , the copper pillar interconnect element 140 extends from the back side 136 towards the interconnect surface 112. In particular, the copper pillar interconnect element 140 is in direct electrical contact with both the sensor block 130 and the substrate 110. In other embodiments, the copper pillar interconnect element can extend between the interconnect surface and the back side in any suitable manner, e.g., from the interconnect surface towards the back side and / or from the back side towards the interconnect surface.

[0068] In these other embodiments, an intermediate layer and / or other elements may or may not be present between the copper pillar interconnect element and the interconnect surface and / or between the copper pillar interconnect element and the back side. Thus, the copper pillar interconnect element can be in direct or indirect electrical contact with the substrate and / or the sensor block. Such an intermediate layer and / or other elements can be configured to improve adhesion, prevent diffusion-related effects, and / or reduce the resistance between the copper pillar interconnect element and the interconnect surface and / or between the copper pillar interconnect element and the back side.

[0069] In Figure 1 and Figure 2 In embodiments of Figure 2 , each copper pillar interconnect element 140 includes a solder tip 141. Such a solder tip can generally provide adaptability to height variations of the copper pillar interconnect element and / or flatness variations of the sensor block and / or the readout integrated circuit. Additionally or alternatively, such a solder tip can help to adjust manufacturing parameters (e.g., temperature and / or compressive pressure) to appropriate levels during the manufacture of the radiation sensor element. In other embodiments, the copper pillar interconnect element may or may not include a solder tip.

[0070] Throughout the specification, "solder" can refer to a fusible metal suitable for coupling or bonding metal elements by melting and solidifying the solder. The solder can include any suitable material, such as indium (In), tin (Sn), bismuth (Bi), silver (Ag), lead (Pb), and / or zinc (Zn).

[0071] Thus, "solder tip" can refer to a structure or portion disposed at the end of an object and containing solder. Specifically, the solder tip of the copper pillar interconnect element can refer to such a structure or portion disposed at the end of the copper pillar interconnect element.

[0072] The solder tip of a copper pillar interconnect element can generally be provided by any suitable means or process. Thus, the process of providing a copper pillar interconnect element can include the process of providing a solder tip for the copper pillar interconnect element, which can include, for example, an electroplating step.

[0073] Figure 1 and Figure 2 In embodiments of Figure 2 , the solder tip 141 of the copper pillar interconnect element 140 is disposed at an end of the copper pillar interconnect element that is closer to the interconnect face 112 than to the back face 136. In other embodiments, the solder tip can be disposed at either end of the copper pillar interconnect element, e.g., at an end closer to the interconnect face than to the back face.

[0074] Figure 1 and Figure 2 The solder tip 141 of embodiments of Figure 2 includes a low-temperature solder. Such a solder tip including a low-temperature solder can help to use a lower process temperature during the manufacturing process of the radiation sensor element, which can help to control material overflow during the manufacturing process by increasing the dynamic viscosity of the relevant materials. Additionally or alternatively, such a solder tip including a low-temperature solder can help to manufacture a radiation sensor element that includes a sensor block having a temperature-sensitive active material (such as a compound semiconductor material). In other embodiments where the copper pillar interconnect element includes a solder tip, the solder tip can include any suitable solder, such as a low-temperature solder.

[0075] As used herein, "low-temperature solder" can refer to a solder having a liquidus temperature and / or a solidus temperature of less than 200 °C, or less than 170 °C, or less than 140 °C.

[0076] Figure 1 and Figure 2 Each solder tip 141 of embodiments of Figure 2 forms part of an electrical conduction path connecting the substrate 110 and the sensor block 130. In other words, multiple current connections passing through the copper pillar interconnect element 140 exist between the substrate 110 and the sensor block 130. Although the radiation sensor element may or may not include a current connection between the substrate and the sensor block, such a current connection is generally provided in an operable radiation detector.

[0077] Throughout this disclosure, "current connection" can refer to an electrical connection between elements that enables a direct current (i.e., unidirectional) current to flow constantly between the elements. Current contact can refer to an electrical connection between two solid elements that provides a direct current path only through solid substances.

[0078] In Figure 1 and Figure 2In an embodiment, the radiation sensor element 100 includes a non-conductive film 150 that extends between the interconnect surface 112 and the back surface 136. Such a non-conductive film can generally improve the mechanical stability of the radiation sensor element and / or reduce the likelihood of electrical breakdown (i.e., arcing) during operation of the radiation sensor element. In other embodiments, the radiation sensor element can generally include such a non-conductive film.

[0079] In this specification, a "non-conductive film" can refer to a layer disposed between the interconnect surface and the back surface. The non-conductive film can generally exhibit a low average electrical conductivity, e.g., at 20 °C, an average electrical conductivity of less than 10 S / m, or less than 1 S / m, or less than 0.1 S / m, or less than 0.01 S / m. The non-conductive film can include any suitable electrically insulating adhesive material, such as varnish, resin, and / or silicone resin. The non-conductive film can include or not include a thermoplastic electrically insulating adhesive material and / or a thermosetting electrically insulating adhesive material, such as epoxy resin. The electrically insulating adhesive can or can not further include sheets of insulating material embedded in the electrically insulating adhesive material, such as ceramic and / or silica particles. The non-conductive film can be disposed on the surface at least in part by a lamination process or can not be disposed on the surface at least in part by a lamination process.

[0080] Although Figure 1 and Figure 2 the non-conductive film 150 of the embodiment of Figure 2 is depicted as a plurality of separate portions in a cross-sectional view of

[0081] Figure 1 and Figure 2 the non-conductive film 150 forms a single continuous (e.g., path-connected) element. In other embodiments, the radiation sensor element can include any suitable number of non-conductive films, such as one, two, three, or more.

[0082] Figure 1 and Figure 2 the non-conductive film 150 of the embodiment of

[0083] In Figure 1 and Figure 2 the front surface 161 of the support plate 160 includes a recess 162 that laterally extends beyond the edge surface 113 of the substrate 110, and the recess 162 extends in a thickness direction perpendicular to the base plane 120. In other embodiments, the front surface of the support plate can generally include such a recess.

[0084] Throughout the specification, "recess" may refer to a sunken or depressed portion of a face or surface. A recess may typically include, for example, a pit, a groove, and / or an edge profile, such as a bevel, a chamfer, or a step. Specifically, the recess on the front face of the support plate may have a depth that is perpendicular to the base plane and measured starting from the base plane.

[0085] In Figure 1 and Figure 2 embodiments, the recess 162 includes a stepped edge profile. Specifically, the recess 162 includes a single-step edge profile. In other embodiments, the recess may include any suitable feature that may have a depth perpendicular to the base plane and measurable starting from the base plane.

[0086] Figure 2 The single-step edge profile of the recess 162 in the embodiments of Figure 2 has a trapezoidal cross-section along the Figure 1 cross-section of

[0087] In Figure 2 embodiments, the front face 161 of the support plate 160 includes a single recess 162. In other embodiments, the front face of the support plate may include any suitable number of recesses, such as one, two, three, or more.

[0088] In Figure 1 and Figure 2 embodiments, the non-conductive film 150 includes an edge protruding portion 151 that laterally extends beyond the edge face 113. Such an edge protruding portion may be formed, for example, due to the flow of an electrically insulating adhesive material in the non-conductive film during the manufacturing process of the radiation sensor element. In some cases, certain types of edge protruding portions may prevent multiple sensor blocks from being arranged closely adjacent to each other. In other embodiments, the non-conductive film may generally include an edge protruding portion.

[0089] Although Figure 1 and Figure 2 the edge protruding portion 151 in the embodiments of Figure 2 is depicted as two separate portions in the cross-sectional view of

[0090] In this document, an "edge protrusion" may refer to a portion of a non-conductive film that laterally extends beyond the edge plane of a substrate. Additionally or alternatively, an edge protrusion may refer to a portion of a non-conductive film that extends at and / or along its lateral edge. Additionally or alternatively, an edge protrusion may refer to a portion of a non-conductive film whose projection on a base plane does not intersect (i.e., does not overlap) the intersection of the projection of an interconnect plane on the base plane and the projection of a back plane on the base plane and is outside of this intersection.

[0091] Figure 1 and Figure 2 The edge protrusion 151 of the embodiment of Figure 1 and Figure 2 has a projection on the base plane 120 that does not intersect the intersection of the projections of the interconnect plane 112 and the back plane 136 on the base plane 120 and is outside of this intersection. In other embodiments, the edge protrusion may or may not have a projection on the base plane that does not intersect the intersection (optional union) of the projections of the interconnect plane and the back plane on the base plane and is outside of this intersection (optional union).

[0092] Figure 1 and Figure 2 The edge protrusion 151 of the embodiment of Figure 1 and Figure 2 extends in the recess 162. An edge protrusion of a non-conductive film that extends in a recess in front of a support plate can generally reduce the lateral diffusion of the non-conductive film during the manufacturing process of a radiation sensor element, which in turn can enable multiple sensor blocks to be arranged closer to each other. In other embodiments, a radiation sensor element may generally include a non-conductive film that includes an edge protrusion that extends in a recess in front of a support plate of the radiation sensor element.

[0093] Figure 1 and Figure 2 The recess 162 of the embodiment of Figure 1 and Figure 2 has a maximum depth d max , and the interconnect plane 112 and the back plane 136 have an average distance d ave from each other. In Figure 1 and Figure 2 the embodiment of Figure 1 and Figure 2 , the ratio between d max and d ave is at least 0.5. Such a ratio can generally significantly reduce the lateral diffusion of a non-conductive film during the manufacturing process of a radiation sensor element. In other embodiments, any suitable ratio may exist between the maximum depth of the recess and the average distance between the interconnect plane and the back plane, such as a ratio of at least 0.5 or at least 1 or at least 1.5.

[0094] As Figure 2 shown using dashed lines and dashed shaded lines in Figure 2 , Figure 1 and Figure 2The radiation sensor element 100 of an embodiment may further include a readout integrated circuit 170. Such a readout integrated circuit can generally assist in detecting radiation in a pixel-by-pixel manner. Additionally or alternatively, such a readout integrated circuit can improve the signal-to-noise ratio of the electrical signals detected using the radiation sensor element. In other embodiments, the radiation sensor element may or may not include such a readout integrated circuit.

[0095] In the present disclosure, an "integrated circuit" may refer to a body or element of a circuit formed on a piece of semiconductor material such as Si.

[0096] Thus, a "readout integrated circuit" may refer to an integrated circuit configured to accumulate charges generated by incident radiation within the active material of a radiation sensor element. Additionally or alternatively, a readout integrated circuit may refer to an integrated circuit configured to move such charges away from the active material for further processing. A readout integrated circuit can generally be configured to operate in a pixel-by-pixel manner.

[0097] In practical applications, a readout integrated circuit may include various technical features related to, for example, the design of individual semiconductor devices, the isolation of individual devices, and / or the internal electrical connections between individual devices. However, for the sake of brevity and clarity, these features are omitted.

[0098] Figure 1 and Figure 2 The readout integrated circuit 170 of an embodiment may be coupled to the substrate 110. In other embodiments, the readout integrated circuit may or may not be coupled to the substrate.

[0099] In Figure 1 and Figure 2 's embodiments, the radiation sensor element 100 may further include an interconnect layer 180 between the substrate 110 and the readout integrated circuit 170. In other embodiments, the radiation sensor element may or may not include such an interconnect layer.

[0100] In the present disclosure, an "interconnect layer" may refer to a layer configured to conduct electric current between two structures or elements. Thus, the interconnect layer between the substrate and the readout integrated circuit may refer to a layer specifically configured to conduct electric current between the substrate and the readout integrated circuit. The interconnect layer may or may not include one or more interconnect elements.

[0101] In this context, an "interconnect element" may refer to an element through which electric current can pass between two structures or elements.

[0102] Figure 1 and Figure 2 's embodiments, the readout integrated circuit 170 may be electrically connected to the active material layer 131 of the sensor block 130. InFigure 1 and Figure 2 In embodiments of and , such current connections can be formed at least in part via the interconnect layer 180, the substrate 110, and the copper pillar interconnect elements 140. Although the radiation sensor element may or may not include a current connection between the readout integrated circuit and the active material layer, such current connections are typically provided in an operable radiation detector.

[0103] Figure 1 and Figure 2 The readout integrated circuit 170 of embodiments of and can have a first face 171 facing the back 163 of the support plate 160. This arrangement of the readout integrated circuit can reduce the radiation exposure of the readout integrated circuit during operation of the radiation detector. In other embodiments in which the radiation sensor element includes a readout integrated circuit that can be coupled to the substrate, the readout integrated circuit may or may not have a first face facing the back of the support plate.

[0104] In Figure 1 and Figure 2 In embodiments of and , the first face 171 of the readout integrated circuit 170 corresponds to the face of the readout integrated circuit 170 through which the readout integrated circuit 170 is electrically connected to the active material layer 131. In other embodiments, the first face of the readout integrated circuit can correspond to any of its faces.

[0105] In Figure 1 and Figure 2 In embodiments of and , the substrate 110 extends between the support plate 160 and the readout integrated circuit 170. In other embodiments, the substrate may or may not extend between the support plate and the readout integrated circuit. For example, in some embodiments, the readout integrated circuit can be arranged between the support plate and the substrate.

[0106] In an embodiment, where the readout integrated circuit coupled to a substrate that may include a flexible circuit and electrically connected to the active material layer has a first face facing the back of the support plate, the lateral extent of the support plate can be limited in at least one lateral direction to facilitate arranging a plurality of sensor blocks closer to each other.

[0107] It should be understood that any of the foregoing embodiments of the first aspect can be used in combination with each other. In other words, several embodiments can be combined together to form another embodiment of the first aspect.

[0108] Above, the structures and materials related to the radiation sensor element have been mainly discussed. In the following, aspects related to the method of manufacturing the radiation sensor element will be emphasized more. The above descriptions of the embodiments, definitions, details, and advantages related to the structures and materials are applicable, with necessary modifications, to the method aspects discussed below. The same applies vice versa.

[0109] It should be particularly understood that the method according to the second aspect can be used to provide a radiation sensor element according to the first aspect and any number of embodiments described in relation to the first aspect. Accordingly, any radiation sensor element according to any embodiment of the first aspect can be manufactured using the method according to the second aspect.

[0110] Figure 3 A method 300 for manufacturing a radiation sensor element according to an embodiment is shown.

[0111] Figure 3 The method 300 of an embodiment of the invention comprises, in process 301, providing a support plate having a front face extending substantially along a base plane defining a lateral extension of a radiation sensor element. The front face of the support plate comprises a recess extending in a thickness direction perpendicular to the base plane.

[0112] In process 302, a substrate is provided, the substrate having a base surface, an interconnect surface opposite to the base surface, and an edge surface connecting the base surface and the interconnect surface.

[0113] In process 303, a sensor block is provided, the sensor block including an active material layer and having a backside.

[0114] In process 304 , a copper pillar interconnect element is provided, and in process 305 , a non-conductive film is provided.

[0115] Any steps to implement one or more of the aforementioned processes 301, 302, 303, 304, 305 may generally be formed in a variety of different orders. Figure 3 This is illustrated by a horizontal arrangement of rectangular symbols representing the process.

[0116] In process 306, the support plate and the substrate are arranged so that the base face of the substrate faces the front of the support plate and the recess of the latter is arranged to extend laterally beyond the edge face. The process 306 of arranging the support plate and the substrate naturally requires first providing these elements. In other embodiments, the implementation corresponding to Figure 3 The steps of the process 306 of the embodiment of the process can generally be completed corresponding to Figure 3 The process 301 of the embodiment is performed after the process 302 .

[0117] In process 307, the sensor block is coupled to the substrate so that the back side of the sensor block faces the interconnection side, the non-conductive film extends between the interconnection side and the back side, the copper pillar interconnection element is arranged between the interconnection side and the back side, and the non-conductive film laterally surrounds the copper pillar interconnection element. Thus, an edge protrusion of the non-conductive film extending in the recess is formed.

[0118] Thus, the process 307 of coupling the sensor block to the substrate represents the actual formation of the stack structure of the radiation sensor elements. The correct execution of the process 307 of coupling the sensor block to the substrate requires the completion of processes 301, 302, 303, 304, 305, and 306. In other embodiments, the process steps of the process 307 that implements the embodiment corresponding to Figure 3 can generally be performed after the processes of the processes 301, 302, 303, 304, 305, and 306 corresponding to the embodiment of Figure 3 are completed.

[0119] In other embodiments, the method for manufacturing the radiation sensor elements may include the steps of the processes 301, 302, 303, 304, 305, 306, and 307 that implement the method 300 corresponding to the embodiment of Figure 3 .

[0120] Generally, the method for manufacturing the radiation sensor elements may include incorporating Figure 3 any number of processes or steps not disclosed herein for the method 300 corresponding to the embodiment of

[0121] For example, in one embodiment, the process of coupling the sensor block to the substrate includes a thermocompression bonding step. In such a thermocompression step, the non-conductive film may flow or diffuse laterally, forming an edge protrusion.

[0122] As used herein, "thermocompression bonding" may refer to a process or process step in which a first metal element (e.g., a solder tip) is pressed onto a second metal element (e.g., a conductor pattern), and at least one of the first metal element and the second metal element is maintained at a temperature significantly higher than 20 °C, such as at least 100 °C or at least 150 °C or at least 200 °C.

[0123] In another embodiment that may be in accordance with the foregoing embodiments, the process of providing the non-conductive film includes laminating the non-conductive film onto the sensor block and / or the substrate. Laminating the non-conductive film can generally simplify the manufacture of the radiation sensor elements. In the embodiment, the process of laminating the non-conductive film onto the sensor block and / or the substrate may or may not include a vacuum lamination step. Laminating the non-conductive film by vacuum lamination can generally increase the manufacturing yield and / or facilitate the lamination of thin layers and / or the lamination on fine features, such as copper pillar interconnect elements. Thus, in the embodiment, the non-conductive film may be laminated onto the copper pillar interconnect elements.

[0124] Throughout the specification, "laminating" may refer to a process or process step in which an element is formed by joining at least two generally sheet-like elements or parts together. Laminating can be achieved, for example, by applying heat, pressure, and / or an adhesive.

[0125] Thus, "vacuum lamination" may refer to a specific type of lamination that is at least partially affected by a fluid pressure differential. Additionally or alternatively, vacuum lamination may refer to a lamination process or step in which bonding is at least partially achieved in a vacuum environment. Such a vacuum environment may have a pressure of less than 1000 Pascals (Pa), or less than 100 Pa, or less than 10 Pa.

[0126] In another embodiment that may be in accordance with the first of the two aforementioned embodiments, the process of providing the non-conductive film includes dispensing the non-conductive film onto the sensor block and / or substrate in the form of a fluid, such as a liquid. Dispensing the non-conductive film in the form of a fluid generally facilitates the manufacture of the radiation sensor element. Such a dispensing process may include, for example, a syringe dispensing step, a spraying step, a spin coating step, and / or a dip coating step. Furthermore, in the described embodiments, the non-conductive film may or may not be dispensed in the form of a fluid between the interconnection face of the substrate and the back face of the sensor block.

[0127] Throughout the disclosure, "providing" may refer to arranging available, the element or part in question. It may include at least partially forming, producing or manufacturing the element or part in question. Additionally or alternatively, providing may include arranging available, ready-made or pre-produced or manufactured elements or parts. For example, when lamination is utilized in process 307 of coupling the sensor block to the substrate, a ready-made non-conductive film may be provided in process 305 and then positioned on the substrate and / or sensor block prior to the coupling process. Alternatively, when providing the non-conductive film includes dispensing the non-conductive film in fluid form, the providing actually constitutes forming, producing or manufacturing the film.

[0128] As used herein, a "step" may refer to a measure taken to achieve a predefined end result. Furthermore, a "process" may refer to a series of one or more steps leading to the end result. Thus, a process may be a single-step process or a multi-step process. Furthermore, a process may be divided into a plurality of sub-processes, wherein each of such a plurality of sub-processes may or may not share common steps.

[0129] The term "comprising" is used in this specification to indicate including the features or actions that follow, without excluding the existence of one or more additional features or actions. It will also be understood that reference to "an" term may refer to one or more of those terms.

[0130] It is obvious to a person skilled in the art that, as technology advances, the basic idea of ​​the invention can be implemented in various ways. Therefore, the invention and its embodiments are not limited to the examples described above, but may vary within the scope of the claims.

[0131] It will be understood that any of the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. Embodiments are not limited to those embodiments that solve any or all of the stated problems or have any or all of the stated benefits and advantages.

[0132] This application also relates to the following aspects:

[0133] Item 1). A radiation sensor element, comprising:

[0134] - A support plate having a front face that extends substantially along a base plane that defines the lateral extent of the radiation sensor element;

[0135] - A substrate having a base face facing the front face, an interconnect face opposite the base face, and an edge face connecting the base face and the interconnect face;

[0136] - A sensor block including an active material layer and having a back face facing the interconnect face;

[0137] - A copper pillar interconnect element between the interconnect face and the back face; and

[0138] - A non-conductive film extending between the interconnect face and the back face and laterally surrounding the copper pillar interconnect element;

[0139] wherein the front face includes a recess that extends laterally beyond the edge face in a thickness direction perpendicular to the base plane, and the non-conductive film includes an edge protruding portion that extends laterally beyond the edge face and extends in the recess.

[0140] Item 2). The radiation sensor element according to item 1), wherein the recess includes a pit, a groove, and / or an edge profile, such as a bevel, a chamfer, or a step.

[0141] Item 3). The radiation sensor element according to item 1) or 2), wherein the substrate includes a flexible circuit.

[0142] Item 4). The radiation sensor element according to any one of the preceding items, wherein the copper pillar interconnect element includes a solder tip.

[0143] Item 5). The radiation sensor element according to item 4), wherein the solder tip includes a low-temperature solder.

[0144] Item 6). The radiation sensor element according to any one of the preceding items, further comprising a readout integrated circuit that is coupled to the substrate and is electrically connected to the active material layer.

[0145] Item 7). The radiation sensor element according to item 6), wherein the support plate has a rear surface opposite to the front surface, and the readout integrated circuit has a first surface facing the rear surface.

[0146] Item 8). The radiation sensor element according to item 7), wherein the support plate comprises metal.

[0147] Item 9). The radiation sensor element according to any one of the preceding items, wherein the ratio between the maximum depth d max of the recess and the average distance d ave between the interconnecting surface and the back surface is at least 0.5 or at least 1 or at least 1.5, the maximum depth being measured perpendicular to the base plane and starting from the base plane.

[0148] Item 10). A method for manufacturing a radiation sensor element, the method comprising:

[0149] - providing a support plate having a front surface extending substantially along a base plane that defines a lateral extent of the radiation sensor element, the front surface comprising a recess that extends in a thickness direction perpendicular to the base plane;

[0150] - providing a substrate having a base surface, an interconnecting surface opposite the base surface, and an edge surface connecting the base surface and the interconnecting surface;

[0151] - providing a sensor block comprising an active material layer and having a back surface;

[0152] - providing copper pillar interconnect elements;

[0153] - providing a non-conductive film;

[0154] - arranging the support plate and the substrate such that the base surface faces the front surface and the recess is arranged to laterally extend beyond the edge surface; and

[0155] - coupling the sensor block to the substrate such that the back surface faces the interconnecting surface, the non-conductive film extends between the interconnecting surface and the back surface, the copper pillar interconnect elements are arranged between the interconnecting surface and the back surface, and the non-conductive film laterally surrounds the copper pillar interconnect elements, thereby forming an edge protruding portion of the non-conductive film extending in the recess.

[0156] Item 11). The method according to item 10), wherein the process of coupling the sensor block to the substrate comprises a thermocompression bonding step.

[0157] Item 12). The method according to item 10) or 11), wherein the process of providing the non-conductive film includes laminating the non-conductive film onto the sensor block and / or the substrate.

[0158] Item 13). The method according to item 12), wherein the process of laminating the non-conductive film onto the sensor block and / or the substrate includes a vacuum lamination step.

[0159] Item 14). The method according to item 10) or 11), wherein the process of providing the non-conductive film includes dispensing the non-conductive film in a fluid form onto the sensor block and / or the substrate.

[0160] Item 15). The method according to any one of items 10) to 14), wherein the radiation sensor element is the radiation sensor element according to any one of items 1) to 9).

[0161] Reference Signs

[0162] 100 Radiation sensor element

[0163] 110 Substrate

[0164] 111 Base surface

[0165] 112 Interconnection surface

[0166] 113 Edge surface

[0167] 114 Conductor trace

[0168] 120 Base plane

[0169] 130 Sensor block

[0170] 131 Active material layer

[0171] 136 Back surface

[0172] 137 Side surface

[0173] 140 Copper pillar interconnection element

[0174] 141 Solder tip

[0175] 150 Non-conductive film

[0176] 151 Edge protrusion

[0177] 160 Support plate

[0178] 161 Front surface

[0179] 162 Recess

[0180] 163 Rear surface

[0181] 170 Readout integrated circuit

[0182] 171 First side

[0183] 180 Interconnection layer

[0184] 300 Method

[0185] 301 Provide a support plate

[0186] 302 Provide a substrate

[0187] 303 Provide a sensor block

[0188] 304 Provide copper pillar interconnect components

[0189] 305 Provide a non-conductive film

[0190] 306 Arrange the support plate and the substrate

[0191] 307 Couple the sensor block to the substrate.

Claims

1. A radiation sensor element (100), comprising: - A support plate (160) having a front surface (161) that extends substantially along a base plane (120), the base plane defining a lateral extent of the radiation sensor element (100); - A substrate (110) having a base surface (111) facing the front surface (161), an interconnect surface (112) opposite the base surface (111), and an edge surface (113) connecting the base surface (111) and the interconnect surface (112); - A sensor block (130) including an active material layer (131) and having a back surface (136) facing the interconnect surface (112); - A copper pillar interconnect element (140) between the interconnect surface (112) and the back surface (136); and - A non-conductive film (150) extending between the interconnect surface (112) and the back surface (136) and laterally surrounding the copper pillar interconnect element (140); wherein the front surface (161) includes a recess (162) that extends laterally beyond the edge surface (113), the recess extending in a thickness direction perpendicular to the base plane (120), and the non-conductive film (150) includes an edge protrusion (151) that extends laterally beyond the edge surface (113) and extends in the recess (162).

2. The radiation sensor element (100) according to claim 1, wherein, The recess (162) includes a pit or a groove.

3. The radiation sensor element (100) according to claim 1, wherein, The recess (162) includes an edge profile.

4. The radiation sensor element (100) according to claim 2 or 3, wherein, The recess (162) includes a bevel, a chamfer, or a step.

5. The radiation sensor element (100) according to any one of claims 1 to 4, wherein, The substrate (110) includes a flexible circuit.

6. The radiation sensor element (100) according to any one of the preceding claims, wherein, The copper pillar interconnect element (140) includes a solder tip (141).

7. The radiation sensor element (100) according to claim 6, wherein, The solder tip (141) includes a low-temperature solder.

8. The radiation sensor element (100) according to any one of the preceding claims, further comprising a readout integrated circuit (170) coupled to the substrate (110) and electrically connected to the active material layer (131).

9. The radiation sensor element (100) according to claim 8, wherein, The support plate (160) has a back surface (163) opposite the front surface (161), and the readout integrated circuit (170) has a first surface (171) facing the back surface (163).

10. The radiation sensor element (100) according to claim 9, wherein, The support plate (160) includes a metal.

11. The radiation sensor element (100) according to any one of the preceding claims, wherein, At the maximum depth d of the recess (162) max and the average distance d between the interconnecting surface (112) and the back surface (136) ave has a ratio of at least 0.5 or at least 1 or at least 1.5, where the maximum depth is measured perpendicular to the base plane (120) and starting from the base plane (120).

12. A method (300) for manufacturing a radiation sensor element, the method (300) comprising: - Providing a support plate (301) having a front surface that extends substantially along a base plane, the base plane defining a lateral extent of the radiation sensor element, the front surface including a recess that extends in a thickness direction perpendicular to the base plane; - Providing a substrate (302) having a base surface, an interconnect surface opposite the base surface, and an edge surface connecting the base surface and the interconnect surface; - Providing a sensor block (303) including an active material layer and having a back surface; - Providing a copper pillar interconnect element (304); - Providing a non-conductive film (305); - Arrange the support plate and the substrate (306) such that the base surface faces the front surface, and the recess is arranged to laterally extend beyond the edge surface; and - Couple the sensor block to the substrate (307) such that the back surface faces the interconnect surface, the non-conductive film extends between the interconnect surface and the back surface, the copper pillar interconnect elements are arranged between the interconnect surface and the back surface, and the non-conductive film laterally surrounds the copper pillar interconnect elements, thereby forming an edge protruding portion of the non-conductive film extending in the recess.

13. The method (300) according to claim 12, wherein, The process of coupling the sensor block to the substrate includes a thermocompression bonding step.

14. The method (300) according to claim 12 or 13, wherein, The process (305) of providing the non-conductive film includes laminating the non-conductive film onto the sensor block and / or the substrate.

15. The method (300) according to claim 14, wherein, The process of laminating the non-conductive film onto the sensor block and / or the substrate includes a vacuum lamination step.

16. The method (300) according to claim 12 or 13, wherein The process (305) of providing the non-conductive film includes dispensing the non-conductive film in a fluid form onto the sensor block and / or the substrate.

17. The method (300) according to any one of claims 12 to 16, wherein The radiation sensor element is the radiation sensor element (100) according to any one of claims 1 to 10.

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