Sensor device

Abstract

Sensor device (1) comprising: an insulating base material (10) having meandering ribbon-shaped parts (BX, BY) and island-shaped parts (I) connected to the ribbon-shaped parts (BX, BY), a first inorganic insulating film (11) arranged over the island-shaped parts (I), a first wiring layer (21) arranged over the first inorganic insulating film (11), a second inorganic insulating film (12) arranged over the first wiring layer (21), a second wiring layer (22) arranged over the second inorganic insulating film (12), an organic insulating film (13) arranged over the second wiring layer (22), a barrier film (14) consisting of an inorganic insulating material and covering the organic insulating film (13), a sensor element (SD) arranged over the barrier film (14), and a sealing film (15).which consists of an inorganic insulating material and covers the sensor element (SD), wherein the sensor element (SD) is an organic photodiode, the barrier film (14) covers a side surface (13S) of the organic insulating film (13), the sealing film (15) is outside the sensor element (SD) in contact with the barrier film (14) and the second inorganic insulating film (12), the sensor element (SD) comprising: a lower electrode (E1) arranged above the barrier film (14), an organic photoelectric conversion layer (OL) arranged above the lower electrode (E1) and outside the lower electrode (E1) in contact with the barrier film (14), and an upper electrode (E2) arranged above the organic photoelectric conversion layer (OL), wherein the sealing film (15) covers the upper electrode (E2) and is in contact with the side surface (OLS) of the organic photoelectric conversion layer (OL) stands,the first inorganic insulating film (11), the second inorganic insulating film (12), the organic insulating film (13), the barrier film (14) and the sealing film (15) extend over the ribbon-shaped part (BX,BY), the organic photoelectric conversion layer (OL) and the upper electrode (E2) extend over the barrier film (14) that overlays the ribbon-shaped part (BX,BY), the lower electrode (E1) is not located directly over the ribbon-shaped part (BX,BY), and the sealing film (15) covers the upper electrode (E2) that overlays the ribbon-shaped part (BX,BY) and is in contact with the side surface (OLS) of the organic photoelectric conversion layer (OL).

Description

Field of InterestThe embodiment of the present invention relates to a sensor device.BackgroundIn recent years, the use of flexible substrates having flexibility and extensibility in various fields is contemplated. As an example, it is conceivable to apply a flexible substrate on which electric elements are arrayed in a matrix manner to a curved surface such as a case of an electronic device or a human body. As electrical elements, for example, various sensors such as touch sensors or temperature sensors and display elements can be used.In the case of a flexible substrate, it is necessary to take a measure so that the wiring is not damaged by bending and stretching stress. As a countermeasure, it is proposed, for example, to design the line in a meandering shape (meandering).Patent Literature 1 discloses an electronic device having a control circuit coupled to input-output devices such as a display. A flexible input-output device is formed from an elastomeric substrate layer. The substrate layer has signal paths to which components are attached.Patent Literature 2 discloses a sensing device including: a substrate; a plurality of first optical sensors provided in a sensing area of the substrate and including an organic material layer having a photovoltaic effect; and at least one or more second optical sensors provided on the substrate and including an inorganic material layer having a photovoltaic effect.PTL 1: US 2017 / 0 003 440 A1PTL2: WO 2021 / 049 262 A1Brief Explanation of the DrawingsFIG. 1 shows a schematic plan view of a sensor device 1 according to an embodiment; FIG. 2 is a plan view showing an example of a flexible substrate 2; FIG. 3 is a sectional view showing an example of the flexible substrate 2 having an island-shaped part I; FIG. 4 is a sectional view showing an example of the flexible substrate 2 having a band-shaped part BX; FIG. 5 is an enlarged plan view of a part of an insulating base material 10 and a sealing film 15; FIG. 6 is a view illustrating a manufacturing method of the flexible substrate 2; FIG. 7 is a view illustrating the manufacturing method of the flexible substrate 2; FIG. 8 is a view illustrating the manufacturing method of the flexible substrate 2; FIG. 9 is a view illustrating the manufacturing method of the flexible substrate 2.DETAILED DESCRIPTIONThe purpose of the embodiment is to provide a sensor device that can suppress a decrease in reliability.As a solution, a sensor device according to the main claim is proposed.According to the embodiment, it is possible to provide a sensor device that can suppress a decrease in reliability.Hereinafter, the present embodiment will be explained with reference to the drawings. The disclosure is merely an example, and the subject matter that is readily apparent to those skilled in the art in view of appropriate modification while retaining the essential content of the invention will be included, of course, within the scope of the present invention. Further, in order to make the explanation more clear, the drawings may schematically show the width, thickness, shape, etc. of the individual parts as compared with the actual shape, but this is merely an example and does not limit the interpretation of the present invention.In the present specification and the respective drawings, constituent elements that exhibit the same or similar functions as those with reference to the already mentioned drawings are denoted by the same reference numerals, and overlapping detailed explanations may be omitted as appropriate.FIG. 1 shows a schematic plan view of a sensor device 1 of the present embodiment. In the present embodiment, the first direction X, the second direction Y, and the third direction Z are defined as shown in the drawing.The first direction X, the second direction Y, and the third direction Z are orthogonal to each other, but they may cross each other at an angle other than 90 degrees. The first direction X and the second direction Y correspond, for example. Directions parallel to the main surface of the sensor device 1 and the third direction Z corresponds to the thickness direction of the sensor device 1.The sensor device 1 is provided with a flexible substrate 2, a circuit board 3, and a regulator 4. The circuit board 3 is, for example, a flexible circuit board electrically connected to each terminal in the terminal area TA of the flexible substrate 2. The regulator 4 is mounted on the circuit board 3, but may be mounted on the flexible substrate 2.The flexible substrate 2 is formed to be flexible and stretchable as a whole. The flexible substrate 2 is provided with a first driver DR 1, a second driver DR 2, X lines WX, Y lines WY, sensor elements SD, and so on.The first driver DR 1 and the second driver DR 2 are arranged on the flexible substrate 2, for example, but may also be arranged on the circuit board 3, the regulator 4, or on another substrate. The X line WX is a general term for lines extending generally along the first direction X, and at least some of the X lines WX are electrically connected to the first driver DR 1. A plurality of X lines WX are aligned in the second direction Y. The Y line WY is a general term for lines extending generally along the second direction Y, and at least some of the Y lines WY are electrically connected to the second driver DR 2. A plurality of Y lines WY are aligned in the first direction X. These X lines WX and Y lines WY include plural kinds of lines such as scan lines, signal lines, power lines and various control lines.A plurality of sensor elements SD are arranged in the form of a matrix in the valid range AA in the first direction X and the second direction Y and are electrically connected to the X lines WX and Y lines WY.The flexible substrate 2 is provided with an insulating base material 10 which will be described later. In an example, the first driver DR 1, the second driver DR 2, the X line WX, the Y line WY, and the sensor elements SD are all disposed over the insulating base material 10.FIG. 2 is a plan view showing an example of the flexible substrate 2.The insulating base material 10 is stretchable. The term "extensible" as used herein refers to the ability to expand and contract, i.e., to expand from a normal unstretched condition and retract upon departure from that stretched condition. The non-stretched state is the state in which no tension is applied.The insulating base material 10 is formed in the shape of a net, for example. That is, the insulating base material 10 includes a plurality of band-shaped parts BX formed generally along the first direction X, a plurality of band-shaped parts BY formed generally along the second direction Y, and a plurality of island-shaped parts I. The plurality of band-shaped parts BX are aligned in the second direction Y and the plurality of band-shaped parts BY are aligned in the first direction X. Each of the band-shaped members BX and BY is stretchable. In one example, the band-shaped parts BX and BY run in meandering fashion. The island-shaped part I corresponds to the intersection point between the band-shaped part BX and the band-shaped part BY.The plurality of island-shaped parts I are arranged in a matrix shape in the first direction X and the second direction Y. The island-shaped parts I adjacent in the first direction X are connected by the band-shaped part BX, and the island-shaped parts I adjacent in the second direction Y are connected by the band-shaped part BY. The island-shaped part I may be quadrangular shapes such as square, rectangular, or rhombic shapes, other polygonal shapes, or other shapes such as circular or oval shapes. The band-shaped parts BX and BY may be connected to the corners of the island-shaped part I or to the sides of the island-shaped part I.In other words, the insulating base material 10 has a plurality of first openings (through holes) OP 1. The plurality of first openings OP 1 are arranged in a matrix shape in the first direction X and the second direction Y. One of the first openings OP 1 is surrounded by the outer edge 10E of the insulating base material 10 in plan view. Alternatively, one of the first openings OP 1 is surrounded by two band-shaped parts BX adjacent in the second direction Y and two band-shaped parts BY adjacent in the first direction X.The band-shaped parts BY are positioned between the two first openings OP 1 adjacent in the first direction X. The band-shaped parts BX are positioned between the two first openings OP 1 adjacent in the second direction Y. The shape of each of the first openings OP 1 is substantially the same.The band-shaped parts BX and BY have one or more curvatures C. Such a shape is possibly referred to as a meandering pattern. However, the shape of the band-shaped parts BX and BY is not limited to the example of FIG. 2. The shapes of the band-shaped parts BX and BY may be identical to each other or different from each other.Such an insulating base material 10 is made of, for example, polyimide. The material of the insulating base material 10 is not limited to polyimide, but other resin materials may be used.The X line WX is disposed over the band-shaped part BX and runs meanderingly like the band-shaped part BX. The Y line WY is disposed over the band-shaped part BY and runs meanderingly like the band-shaped part BY.The sensor element SD is disposed over the island-shaped part I and electrically connected to the X lines WX and Y lines WY. For example, a single sensor element SD is disposed on a single island-shaped part I, but a plurality of sensor elements SD may be disposed. The sensor element SD is a photoelectric conversion element or an optical sensor that receives light and outputs an electric signal. In the present embodiment, the sensor element SD is an organic photodiode having an organic photoelectric conversion layer in one example. The sensor element SD may also be other elements such as an inorganic photodiode.FIG. 3 is a sectional view showing an example of the flexible substrate 2 having the island-shaped part I.The flexible substrate 2 is provided with the insulating base material 10, a first inorganic insulating film 11, a first wiring layer 21, a second inorganic insulating film 12, a second wiring layer 22, an organic insulating film 13, a barrier film 14, the sensor elements SD, and a sealing film 15. The insulating base material 10 shown in the drawing corresponds to the island-shaped part I shown in FIG. 2.The whole of the flexible substrate 2 may be covered with a stretchable protective film. Although the illustration of the protective film is omitted, the back surface of the insulating base material 10 and the surface of the sealing film 15 may be covered with the protective film.The first inorganic insulating film 11 is disposed over the insulating base material 10 or the island-shaped part I. The first wiring layer 21 is disposed over the first inorganic insulating film 11. The second inorganic insulating film 12 is disposed over the first wiring layer 21. The second wiring layer 22 is disposed over the second inorganic insulating film 12.The first inorganic insulating film 11 and the second inorganic insulating film 12 are each formed as a multilayer body having a plurality of stacked insulating layers. In an example, the first inorganic insulating film 11 and the second inorganic insulating film 12 each include a silicon nitride layer and a silicon oxide layer. The first inorganic insulating film 11 and the second inorganic insulating film 12 may also be single-layered bodies.The first wiring layer 21 is electrically connected to one of the X lines WX and Y lines WY shown in FIG. 2. The second wiring layer 22 is electrically connected to the other of the X line WX and the Y line WY. In an example, the first wiring layer 21 is electrically connected to the X line WX and includes a gate electrode of a switching element. The second wiring layer 22 includes a source and drain electrodes of the switching element, the source electrode being electrically connected to the Y line WY, and the drain electrode being electrically connected to the sensor element SD. The second wiring layer 22 corresponds to the drain electrode DE in the drawing.The organic insulating film 13 is disposed over the second inorganic insulating film 12 and the second wiring layer 22, and has a contact hole CH 1 penetrating to the drain electrode DE. The barrier film 14 covers the entire organic insulating film 13. That is, the barrier film 14 covers not only the upper surface 13T of the organic insulating film 13 but also the side surface 13S. The barrier film 14 has a contact hole CH2 penetrating to the drain electrode DE in the contact hole CH1.The barrier film 14 is an inorganic insulating film made of, for example, an inorganic insulating material such as silicon nitride or aluminum oxide. Since the barrier film 14 covers the entire organic insulating film 13, the penetration of water into the organic insulating film 13 or the diffusion of water contained in the organic insulating film 13 is suppressed.The sensor element SD is disposed over the barrier film 14. The sensor element SD is provided with a lower electrode E 1, an upper electrode E 2, and an organic photoelectric conversion layer OL. Either the lower electrode E 1 or the upper electrode E 2 functions as an anode of the sensor element SD, and the other as a cathode of the sensor element SD.The lower electrode E1 is positioned directly above the upper surface 13T, disposed above the barrier film 14, and in contact with the barrier film 14, and the lower electrode E1 is further in contact with the drain electrode DE in the contact holes CH1 and CH2. The lower electrode E 1 is patterned for each sensor element SD (or island-shaped part I).The lower electrode E1 is made of, for example, a transparent conductive material such as indium tin oxide, indium zinc oxide, or a metallic material such as silver, titanium, or aluminum. The lower electrode E1 may be a single-layered body of transparent conductive material, a single-layered body of metallic material, or a multi-layered body of a layer of transparent conductive material and a layer of metallic material.The organic photoelectric conversion layer OL is disposed above the lower electrode E 1 and is in contact with the lower electrode E 1. The organic photoelectric conversion layer OL extends outward of the lower electrode E 1 directly over the upper surface 13T and is in contact with the barrier film 14.The upper electrode E 2 is disposed above the organic photoelectric conversion layer OL and is in contact with the organic photoelectric conversion layer OL. The upper electrode E 2 extends over not only the island-shaped part I but also the band-shaped part as described below, and is integrally formed with the upper electrode of the adjacent sensor element SD. That is, the upper electrode E 2 is a common electrode disposed via the plurality of sensor elements SD. Such an upper electrode E2 is made of, for example, a transparent conductive material such as indium tin oxide or indium zinc oxide.The seal film 15 covers the sensor element SD. That is, the sealing film 15 covers the upper electrode E 2 and is in contact with the side surface OLS of the organic photoelectric conversion layer OL. The seal film 15 is also in contact with the barrier film 14 outside the sensor element SD. That is, the seal film 15 covers a part of the barrier film 14 that is in contact with the side surface 13S, and further covers the end 14E of the barrier film 14. The sealing film 15 is further in contact with the second inorganic insulating film 12 exposed from the barrier film 14. In the example shown, the sealing film 15 is not in contact with the insulating base material 10, the first inorganic insulating film 11, and the first wiring layer 21.Moreover, the sealing film 15 has second openings (through holes) OP 2 overlying the first opening OP 1 of the insulating base material 10. The second opening OP 2 is surrounded by the outer edge 15E of the seal film 15.The seal film 15 is an inorganic insulating film and is made of, for example, an inorganic insulating material such as silicon nitride or aluminum oxide. In one example, the seal film 15 is made of the same material as the barrier film 14. therefore, the barrier film 14 and the seal film 15 have a high degree of adhesion, and thus high sealing performance can be achieved.As explained above, the sensor element SD is an organic photodiode and is provided with the organic photoelectric conversion layer OL. The barrier film 14 formed as a base of the sensor element SD covers the entire organic insulating film 13, so that the intrusion of water from the organic insulating film 13 to the sensor element SD is suppressed. In addition, the sensor element SD is sealed by the sealing film 15. Therefore, the sensor element SD is not exposed to the outside air, and the intrusion of water into the sensor element SD is also suppressed. Consequently, deterioration of the sensor element SD, particularly the organic photoelectric conversion layer OL by outside air and water is suppressed. Consequently, the decrease in reliability is suppressed.FIG. 4 is a sectional view showing an example of the flexible substrate 2 having the band-shaped part BX. Although the section with the band-shaped part BX is explained in FIG. 4, the section with the band-shaped part BY is designed the same as the section with the band-shaped part BX, so the explanation is omitted.The first inorganic insulating film 11, the second inorganic insulating film 12, the organic insulating film 13, the barrier film 14, and the sealing film 15 extend over the band-shaped part BX of the insulating base material 10.That is, the first inorganic insulating film 11 is disposed over the band-shaped part BX of the insulating base material 10, the first wiring layer 21 is disposed over the first inorganic insulating film 11, the second inorganic insulating film 12 is disposed over the first wiring layer 21, the second wiring layer 22 is disposed over the second inorganic insulating film 12, and the organic insulating film 13 is disposed over the second inorganic insulating film 12 and the second wiring layer 22. In addition, the barrier film 14 covers almost the entire organic insulating film 13 including the upper surface 13T and the side surface 13S.The lower electrode E 1 or a conductive layer of the same layer as the lower electrode E 1 is not disposed directly over the band-shaped part BX.The organic photoelectric conversion layer OL and the upper electrode E 2 directly extend over the band-shaped part BX. That is, the organic photoelectric conversion layer OL and the upper electrode E 2 extend over the barrier film 14 that overlies the belt-shaped part BX. The organic photoelectric conversion layer OL is in contact with the almost entire upper surface 14T of the barrier film 14. the upper electrode E 2 overlies almost the entire organic photoelectric conversion layer OL.The sealing film 15 covers the upper electrode E 2 and is in contact with the side surface OLS of the organic photoelectric conversion layer OL. The sealing film 15 is also in contact with the barrier film 14 outside the organic photoelectric conversion layer OL. The sealing film 15 is also in contact with the second inorganic insulating film 12 exposed from the barrier film 14.In the section of the band-shaped part BX illustrated in FIG. 4, one of the first wiring layer 21 and the second wiring layer 22 may be omitted. At least one of these first wiring layer 21 and second wiring layer 22 forms the X line WX disposed in the band-shaped part BX. Although not illustrated, at least one of the first wiring layer 21 and the second wiring layer 22 forms the Y line WY disposed in the band-shaped part BY in section with the band-shaped part BY.FIG. 5 is an enlarged plan view of a part of the insulating base material 10 and the sealing film 15.In plan view, the second opening OP 2 surrounded by the outer edge 15E of the sealing film 15 overlaps the first opening OP 1 surrounded by the outer edge 10E of the insulating base material 10. The seal film 15 is further formed wider than the insulating base material 10, and the area of the second opening OP 2 is smaller than the area of the first opening OP 1. In other words, in the plan view, the outer edge 10E overlaps the sealing film 15 and the outer edge 15E overlaps the first opening OP 1. The width WE from the outer edge 10E to the outer edge 15E is smaller than the width W 10 of the insulating base material 10, and is, for example, 2.5 μm or more. The width WE is substantially equal on both sides across the insulating base material 10.Next, the method of manufacturing the above flexible substrate 2 will be explained with reference to Figs. 6 to 9.First, as shown in the upper stage in FIG. 6, after the first inorganic insulating film 11 is formed over the insulating base material 10 made of, for example, polyimide, the first wiring layer 21 patterned in a predetermined shape is formed over the first inorganic insulating film 11, and after the second inorganic insulating film 12 is formed, the second wiring layer 22 patterned in a predetermined shape is formed over the second inorganic insulating film 12. The structuring of the first inorganic insulating film 11 and the second inorganic insulating film 12 may be performed together or individually.Thereafter, as shown in the middle stage, the organic insulating film 13 is formed over the entire area. Here, the organic insulating film 13 is also formed between the adjacent inorganic insulating films 11 and is in contact with the insulating base material 10.Thereafter, as shown in the lower stage, the organic insulating film 13 patterned in a predetermined shape is formed. In patterning the organic insulating film 13, the contact hole CH 1 penetrating to the second wiring layer 22 (or drain electrode) is formed. Here, a part of the organic insulating film 13A remains between the adjacent inorganic insulating films 11.Subsequently, as shown in the upper stage in FIG. 7, the barrier film 14 patterned in a predetermined shape is formed. The barrier film 14 is formed so as to cover the entire organic insulating film 13 including the upper surface 13T and the side surface 13S. In patterning the barrier film 14, the contact hole CH 2 penetrating to the second wiring layer 22 is formed. Here, the organic insulating film 13A is exposed from the barrier film 14.Thereafter, as shown in the middle stage, the lower electrode E1 patterned in a predetermined shape is formed. The lower electrode E 1 is formed so as to be in contact with the second wiring layer 22 in the contact hole CH 2.Thereafter, the organic photoelectric conversion layer OL is formed over the entire area as shown in the lower stage.Subsequently, as shown in the upper stage in FIG. 8, after forming the upper electrode E 2 over the entire surface of the organic photoelectric conversion layer OL, a resist R 1 patterned in a predetermined shape is formed over the upper electrode E 2.Then, as shown in the middle stage, the upper electrode E 2 exposed from the resist R 1 is removed by etching with the resist R 1 serving as a mask, and moreover, the organic photoelectric conversion layer OL exposed from the upper electrode E 2 is removed by an oxygen plasma treatment or an ashing treatment. Here, the surface layer of the organic insulating film 13A serving as a base of the organic photovoltaic conversion layer OL between the adjacent first inorganic insulating films 11 is also removed. By this reduction of the organic insulating film 13A, the side surface 12S of the second inorganic insulating film 12 is exposed.Thereafter, as shown in the lower stage, after removing the resist R1, the seal film 15 is formed over the entire area, and then a resist R2 patterned in a predetermined shape is formed over the seal film 15. The sealing film 15 is formed so as to cover the sensor element SD and the barrier film 14, and is in contact with the side surface 12S of the second inorganic insulating film 12.Subsequently, as shown in the upper stage in FIG. 9, the sealing film 15 exposed from the resist R 2 is removed using the resist R 2 as a mask, the organic insulating film 13A exposed from the sealing film 15 is removed, and moreover, the insulating base material 10 exposed from the organic insulating film 13A is also removed. As shown in FIG. 5, the first opening OP 1 defined by the outer edge 10E of the insulating base material 10 and the second opening OP 2 defined by the outer edge 15E of the sealing film 15 are formed.Thereafter, as shown in the lower stage, the resist R2 is removed and the flexible substrate 2 is prepared.As explained above, according to the present embodiment, it is possible to provide a sensor device that can suppress a decrease in reliability.

Claims

A sensor device (1) comprising: an insulating base material (10) having meandering belt-shaped parts (BX,BY) and island-shaped parts (I) connected to the belt-shaped parts (BX,BY), a first inorganic insulating film (11) disposed over the island-shaped parts (I), a first wiring layer (21) disposed over the first inorganic insulating film (11), a second inorganic insulating film (12) disposed over the first wiring layer (21), a second wiring layer (22) disposed over the second inorganic insulating film (12), an organic insulating film (13) disposed over the second wiring layer (22), a barrier film (14) made of an inorganic insulating material and covering the organic insulating film (13), a sensor element (SD) disposed over the barrier film (14), and a sealing film (15) made of an inorganic insulating material and covering the sensor element (SD), wherein the sensor element (SD) is an organic photodiode, the barrier film (14) covers a side surface (13S) of the organic insulating film (13), the sealing film (15) outside the sensor element (SD) is in contact with the barrier film (14) and the second inorganic insulating film (12), the sensor element (SD) comprising: a lower electrode (E1) disposed above the barrier film (14), an organic photoelectric conversion layer (OL) disposed above the lower electrode (E1) and in contact with the barrier film (14) outside the lower electrode (E1), and an upper electrode (E2), which is disposed over the organic photoelectric conversion layer (OL), wherein the sealing film (15) covers the upper electrode (E2) and is in contact with the side surface (OLS) of the organic photoelectric conversion layer (OL), the first inorganic insulating film (11), the second inorganic insulating film (12), the organic insulating film (13), the barrier film (14) and the sealing film (15) extend over the belt-shaped part (BX,BY), the organic photoelectric conversion layer (OL) and the upper electrode (E2) extend over the barrier film (14) which overlies the belt-shaped part (BX,BY), the lower electrode (E1) is not disposed directly over the belt-shaped part (BX,BY), and the sealing film (15) covers the upper electrode (E2) which is superposed on the belt-shaped portion (BX,BY) and in contact with the side surface (OLS) of the organic photoelectric conversion layer (OL).The sensor device (1) according to claim 1, wherein the insulating base material (10) has first openings (OP1) surrounded by the band-shaped parts (BX, BY), the sealing film (15) has second openings (OP2) overlying the first openings (OP1) in plan view, and the area of the second opening (OP2) is smaller than the area of the first opening (OP1).The sensor device (1) according to claim 2, wherein in the plan view, the outer edge (15E) of the sealing film (15) overlies the first opening (OP1), and the width (WE) from the outer edge (10E) of the insulating base material (10) to the outer edge (15E) of the sealing film (15) is 2.5 μm or more.The sensor device (1) according to claim 1, wherein the barrier film (14) and the sealing film (15) are made of silicon nitride or aluminum oxide.

Images