Imaging module and imaging device

Abstract

This technology suppresses the adhesion of foreign matter to the light-receiving surface of the image sensor while also suppressing image blurring caused by the light-receiving surface being out of focus of the lens. [Solution] The imaging module comprises an image sensor having a light-receiving surface for receiving light, and a cover member that covers the light-receiving surface of the image sensor. The cover member is curved such that the surface facing the light-receiving surface protrudes toward the image sensor, and the image sensor is laminated on the opposing surface with an adhesive layer in between, and is curved such that the light-receiving surface is recessed toward the opposite side from the cover member.

Description

Technical Field

[0001] The present invention relates to an imaging module and an imaging apparatus.

Background Art

[0002] Patent Document 1 discloses an imaging element including an imaging chip in which a recess is formed on the back surface, which is a surface different from the light receiving surface that receives light from a subject. In this imaging element, the imaging chip is curved by a curve forming portion disposed on the back surface side of the imaging chip to form the recess.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] When the light receiving surface of the imaging element is flat, deviation from the focal point of the lens occurs at the outer peripheral portion of the light receiving surface, which may cause blurring in the image acquired by the imaging element. On the other hand, when the light receiving surface is supported and curved from the back surface side in order to suppress blurring of the image, if the light receiving surface is exposed, foreign matter such as dust may adhere to the light receiving surface. An object of the present invention is to suppress blurring of an image caused by deviation of the light receiving surface from the focal point of a lens, while suppressing adhesion of foreign matter to the light receiving surface of an imaging element.

Means for Solving the Problem

[0005] [1] An imaging module comprising an image sensor having a light-receiving surface for receiving light, and a cover member covering the light-receiving surface of the image sensor, wherein the cover member is curved such that the surface facing the light-receiving surface protrudes toward the image sensor, and the image sensor is laminated on the facing surface with an adhesive layer in between, and the light-receiving surface is curved such that it is recessed toward the side opposite to the cover member. [2] The imaging module according to [1], wherein the image sensor has a light-receiving surface that is curved along the opposing surface of the cover member. [3] The imaging module according to [1], wherein the image sensor has electrode pads around the light-receiving surface, and the cover member has wiring connected to the electrode pads around the opposing surface. [4] The imaging module according to [3], further comprising an interposer substrate connected to the wiring of the cover member, wherein a space is formed in the center on which at least the light-receiving surface of the image sensor is arranged. [5] The imaging module according to [3], wherein the electrode pads of the image sensor and the wiring of the cover member are connected by at least one of an anisotropic conductive film or bumps. [6] The imaging module according to [3], having a protective portion arranged on the outer circumference of the image sensor to protect the electrode pads. [7] The imaging module according to [1], wherein the difference between the refractive index of the cover member and the refractive index of the adhesive layer is 0.2 or less. [8] The imaging module according to [7], wherein the image sensor includes a microlens on the light-receiving surface, and the refractive index of the adhesive layer is smaller than the refractive index of the microlens. [9] The imaging module according to [1], further comprising a heat dissipation member on the side of the image sensor opposite to the light-receiving surface for dissipating heat from the image sensor.

[10] The imaging module according to [1], wherein the cover member has a curved surface on the side opposite to the opposing surface.

[11] The imaging module according to [1], wherein the curved surfaces formed on the light-receiving surface of the image sensor and the opposing surface of the cover member have curvature in two orthogonal directions and the curvatures are different.

[12] The imaging module according to [1], wherein the curved surfaces formed on the light-receiving surface of the image sensor and the opposing surface of the cover member have curvature in only one of two orthogonal directions. An imaging device comprising an imaging module described in any one of

[13] [1] to

[12] , a lens that focuses light onto the light-receiving surface of the image sensor, and a holding member that holds the lens.

[14] The imaging apparatus according to

[13] , wherein the holding member is attached to the cover member. [Effects of the Invention]

[0006] According to the present invention, it is possible to suppress the adhesion of foreign matter to the light-receiving surface of the image sensor while suppressing image blurring caused by the light-receiving surface being out of focus of the lens. [Brief explanation of the drawing]

[0007] [Figure 1] This figure shows an example of the configuration of an imaging device to which this embodiment is applied. [Figure 2] This figure shows an example of the configuration of an imaging module to which this embodiment is applied. [Figure 3] This is a cross-sectional view of the imaging module taken at section III in Figure 2. [Figure 4] This is an enlarged view of section IV in Figure 3. [Figure 5] This diagram shows an example of the relationship between light incident on a lens and the light-receiving surface in an image sensor where the light-receiving surface is flat. [Figure 6] Figures (a) and (b) show an example of a manufacturing method for an imaging module to which this embodiment is applied. [Figure 7] Figures (a) to (c) show an example of the configuration of an imaging module to which Embodiment 2 is applied. [Figure 8] Figures (a) to (c) show an example of the configuration of an imaging module to which Embodiment 3 is applied. [Figure 9] Figures (a) and (b) show the first and second modified versions of the imaging module, respectively. [Figure 10] Respective (a) to (b) are diagrams showing the third modified example and the fourth modified example of the imaging module. [Modes for Carrying Out the Invention]

[0008] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the following embodiments. In addition, the present invention can be implemented with various modifications within the scope of its gist. Furthermore, the drawings used below are for describing the embodiments of the present invention, and do not represent actual dimensions.

[0009] [Embodiment 1] (Imaging Apparatus 1) Figure 1 is a diagram showing an example of the configuration of the imaging apparatus 1 to which the present embodiment is applied. Figure 1 is a cross-sectional view taken along the optical axis (indicated by the one-dot chain line in Figure 1) of the imaging apparatus 1. In Figure 1, the direction from the left to the right of the paper surface is defined as the x direction, the direction from the near side to the far side of the paper surface is defined as the y direction, and the direction from the bottom to the top of the paper surface is defined as the z direction. The z direction corresponds to the optical axis direction of the imaging apparatus 1. The imaging apparatus 1 includes a lens unit 2 that forms an image of light from a subject, a lens holder 3 that holds the lens unit 2, and an imaging module 4 that receives light transmitted through the lens unit 2 to acquire an image.

[0010] The lens unit 2 includes a plurality of lenses 21 arranged in the z direction, and a barrel 22 that accommodates the plurality of lenses 21 inside. The barrel 22 is formed with an opening 22A through which light enters. The plurality of lenses 21 are held inside the barrel 22 such that light incident from the opening 22A forms an image on a light receiving surface 5A (see Figure 2 described later) of an imaging element 5 of the imaging module 4 to be described later by the plurality of lenses 21.

[0011] The lens holder 3 has the lens unit 2 mounted therein, and holds the lens unit 2 such that the lens 21 included in the lens unit 2 and an image sensor 5, which will be described later, of the imaging module 4 have a predetermined positional relationship. More specifically, the lens holder 3 holds the lens unit 2 such that the optical axis of the lens unit 2 and the optical axis of the image sensor 5 coincide with each other, and the distance between the lens unit 2 and the image sensor 5 is a predetermined distance. The lens holder 3 is an example of a holding member.

[0012] In this example, the lens holder 3 is attached to a cover member 6, which will be described later, of the imaging module 4. More specifically, the lens holder 3 is attached to the light-receiving surface side of the cover member 6. Further, as will be described later, the cover member 6 is integrated with the image sensor 5. This suppresses misalignment between the optical axis of the lens unit 2 and the optical axis of the image sensor 5, and improves the tilt accuracy between the lens unit 2 and the image sensor 5. In the description of the present embodiment, regarding the image sensor 5, the cover member 6, and the like, the surface on which the light passing through the lens unit 2 is incident (the upper surface in FIG. 1) may be referred to as a light-receiving surface. In addition, the surface opposite to the light-receiving surface (the lower surface in FIG. 1) may be referred to as a lower surface.

[0013] (Imaging Module 4) FIG. 2 is a diagram illustrating an example of the configuration of the imaging module 4 to which the present embodiment is applied. FIG. 2 corresponds to a view of the imaging module 4 as seen along the z direction from the lens unit 2 (see FIG. 1) side. In FIG. 2, the cover member 6 present on the near side of the drawing sheet is indicated by a broken line, and the structure in which the image sensor 5 is present on the far side of the drawing sheet relative to the cover member 6 is indicated by a solid line. FIG. 3 is a cross-sectional view of the imaging module 4 taken at section III in FIG. 2. FIG. 4 is an enlarged view of section IV in FIG. 3. Note that in FIG. 2 to FIG. 4, an interposer substrate 9 (see FIG. 1), which will be described later, of the imaging module 4 is omitted.

[0014] The imaging module 4 includes an image sensor 5 that converts light received on a light-receiving surface 5A (described later) into an electrical signal. The imaging module 4 also includes a cover member 6 that covers the light-receiving surface 5A of the image sensor 5. The imaging module 4 also includes an adhesive layer 7 provided between the light-receiving surface 5A and the cover member 6. The imaging module 4 also includes a plurality of conductive parts 8 that electrically connect the image sensor 5 and the cover member 6. The imaging module 4 also includes an interposer substrate 9 that is electrically connected to the image sensor 5 via the cover member 6 and the conductive parts 8. An imaging module 4 is connected to a control device (not shown) via an interposer board 9, and the operation of the image sensor 5 is controlled based on the control provided by the control device.

[0015] (Image sensor 5) The image sensor 5 has a rectangular and thin plate-like shape when viewed along the z-direction. The image sensor 5 includes a pixel array section 51 in which multiple pixels 50 are arranged in two dimensions. The image sensor 5 also includes a wiring section 52 that transmits electrical signals between the pixel array section 51 and the wiring of the cover member 6, which will be described later.

[0016] The pixel array section 51 is located on the light-receiving surface side of the image sensor 5. Furthermore, the pixel array section 51 is located in the center of the image sensor 5 when viewed along the z-direction. Additionally, the pixel array section 51 is positioned so that its center coincides with the optical axis of the lens unit 2. The pixel array section 51 has a rectangular shape when viewed along the z-direction, with the x-direction as the major axis and the y-direction as the minor axis. In the pixel array section 51, multiple pixels 50 are arranged in a grid pattern along the x-direction and the y-direction.

[0017] Each pixel 50 of the pixel array 51 has a photoelectric conversion element 511, a color filter 512, and a microlens 513. The photoelectric conversion element 511 is composed of an image sensor such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor). The photoelectric conversion element 511 converts the light received through the microlens 513 and color filter 512 into an electrical signal and outputs it.

[0018] The color filter 512 is provided on the photoelectric conversion element 511. The color filter 512 has the function of transmitting light in a specific wavelength range. The color filter 512 includes an R color filter that transmits light in the red (R) wavelength range, a G color filter that transmits light in the green (G) wavelength range, and a B color filter that transmits light in the blue (B) wavelength range.

[0019] The microlenses 513 are provided on each color filter 512. The microlenses 513 are also provided on the light-receiving surface side of the color filter 512 in the pixel array section 51. In this embodiment, the light-receiving surface of the microlenses 513 in the pixel array section 51 is defined as the light-receiving surface 5A of the image sensor 5. In this example, when viewed from the z direction in a plan view, the light-receiving surface 5A has a rectangular shape with the x direction as the major axis and the y direction as the minor axis. The microlens 513 is a plano-convex spherical lens that focuses the incident light onto the photoelectric conversion element 511 via the color filter 512. The microlens 513 is formed from a material with a higher refractive index than the cover member 6 and the adhesive layer 7.

[0020] The wiring section 52 is provided continuously around the pixel array section 51 and in the area on the same plane as the light-receiving surface 5A of the pixel array section 51. When viewed along the z-direction, the wiring section 52 has a rectangular shape. The wiring section 52 has wiring that is electrically connected to each photoelectric conversion element 511 of the pixel array section 51 and transmits electrical signals. The wiring section 52 is formed on the surface or inside a substrate made of, for example, Si.

[0021] Furthermore, the wiring section 52 has a plurality of electrode pads 521 to which the conductive section 8 is connected. The plurality of electrode pads 521 are provided on the surface of the wiring section 52 facing the cover member 6, and on the light-receiving surface side of the image sensor 5. The wiring of the wiring section 52 is electrically connected to the wiring of the cover member 6 via the electrode pads 521 and the conductive section 8. In this example, the multiple electrode pads 521 are arranged along the outer circumference of the rectangular wiring section 52. Furthermore, the multiple electrode pads 521 are arranged around the light-receiving surface 5A.

[0022] In this embodiment, the image sensor 5 has a light-receiving surface 5A that is curved so as to be concave toward the opposite side of the cover member 6, that is, toward the opposite side of the light-receiving surface. In addition, the image sensor 5 has a light-receiving surface 5A that is curved along the opposing surface 62A of the cover member 6, which will be described later. Furthermore, at least the light-receiving surface 5A of the image sensor 5 is positioned inside the space 9A formed in the center of the interposer substrate 9. The shape of the light-receiving surface 5A of the image sensor 5, the relationship between the image sensor 5 and the cover member 6, and the effects of the curvature of the image sensor 5 will be explained in detail later.

[0023] (Cover member 6) The cover member 6 is provided on the light-receiving surface side of the image sensor 5 in the imaging module 4 and covers the light-receiving surface 5A. The cover member 6 is made of a material that can transmit visible light. Glass can be used as an example of a material that makes up the cover member 6. The cover member 6 has a flat base portion 61. The cover member 6 is also molded integrally with the base portion 61 and has a projection portion 62 that protrudes from the base portion 61 toward the downward side (opposite side from the light-receiving surface).

[0024] The base portion 61 has a rectangular shape when viewed along the z-direction. The area of ​​the base portion 61 when viewed along the z-direction is larger than the wiring portion 52 of the image sensor 5. As a result, the outer periphery of the base portion 61 is exposed to the outside of the wiring portion 52. The base portion 61 has wiring 611 formed on it, which is connected to the electrode pad 521 via a conductive portion 8 and transmits electrical signals. The wiring 611 is formed on the lower surface of the base portion 61. Furthermore, the wiring 611 is formed on the outer circumference of the base portion 61 that is exposed outside the wiring portion 52 of the image sensor 5. In addition, the wiring 611 is provided around the opposing surface 62A of the protruding portion 62, which will be described later. The wiring 611 can be formed, for example, on the base 61 of the cover member 6, which is made of glass, by metallization.

[0025] The wiring 611 has terminals located on the inner circumference side of the base portion 61 that are connected to the electrode pads 521 of the image sensor 5 via the conductive portion 8. Furthermore, the terminals of the wiring 611 located on the outer circumference of the base 61 are connected to the interposer substrate 9 via electrodes 65. The electrodes 65 are composed of bumps made of, for example, gold.

[0026] The protruding portion 62 is located in the center of the base portion 61 when viewed along the z-direction. The protruding portion 62 has a curved shape such that the opposing surface 62A facing the light-receiving surface 5A of the image sensor 5 protrudes toward the image sensor 5. In this example, the shape of the protrusion 62 when viewed along the z-direction is a circular shape centered on the optical axis of the imaging device 1 (see Figure 1). The opposing surface 62A is a spherical shape that protrudes toward the image sensor 5 with respect to the optical axis. Furthermore, the opposing surface 62A is a curved surface in which the curvature in the x-direction and the curvature in the y-direction are equal.

[0027] (adhesive layer 7) The adhesive layer 7 is provided between the light-receiving surface 5A of the image sensor 5 and the opposing surface 62A of the cover member 6. The adhesive layer 7 adheres the light-receiving surface 5A and the opposing surface 62A, integrating the image sensor 5 and the cover member 6. The adhesive layer 7 is made of a material that can transmit visible light.

[0028] In the imaging device 1, if the image sensor 5 and the cover member 6 are directly laminated without an adhesive layer 7 in between, a gap may form between the light-receiving surface 5A and the opposing surface 62A. As described above, since the image sensor 5 is equipped with a microlens 513 on the light-receiving surface 5A, a gap is likely to form between the light-receiving surface 5A and the opposing surface 62A due to the unevenness of the microlens 513. In contrast, the imaging device 1 of this embodiment includes an adhesive layer 7, which suppresses the formation of a gap between the light-receiving surface 5A of the image sensor 5 and the opposing surface 62A of the cover member 6. Furthermore, by including an adhesive layer 7, the imaging device 1 suppresses the load on the microlens 513 when the light-receiving surface 5A and the opposing surface 62A come into contact.

[0029] The adhesive layer 7 is preferably formed from a material with a refractive index close to that of the cover member 6. The difference between the refractive index of the adhesive layer 7 and the refractive index of the cover member 6 is preferably 0.2 or less, and more preferably they are equal. A difference of 0.2 or less in refractive index between the adhesive layer 7 and the cover member 6 makes it easier to suppress the reflectance at the interface between the adhesive layer 7 and the cover member 6, which is caused by the difference in refractive index, to less than 1%. Furthermore, it is preferable that the adhesive layer 7 is formed of a material with a refractive index lower than that of the microlens 513 of the image sensor 5. The refractive indices of the adhesive layer 7, the cover member 6, and the microlens 513 satisfy this relationship, making it easier for light incident on the cover member 6 to pass through the adhesive layer 7 and the microlens 513 and be focused onto the photoelectric conversion element 511 of the image sensor 5.

[0030] Acrylic can be used as an example of a material that constitutes the adhesive layer 7.

[0031] (Conductive section 8) The conductive portion 8 electrically connects the electrode pad 521 provided on the wiring portion 52 of the image sensor 5 with the wiring 611 provided on the base portion 61 of the cover member 6. The conductive portion 8 is preferably composed of a film having anisotropic conductivity (hereinafter referred to as anisotropic conductive film), or a bump made of metal or an alloy. An anisotropic conductive film is conductive in the z-direction (thickness direction) and insulating in the x-direction and y-direction (plane directions). Furthermore, the bumps are made of materials such as gold, silver, copper, nickel, and solder, and are preferably made of gold.

[0032] (Interposer substrate 9) The interposer substrate 9 includes electrodes 65, wiring 611, and a rewiring layer connected to the image sensor 5 via conductive portions 8 provided on the cover member 6. The interposer substrate 9 has a space 9A formed in the center that penetrates the interposer substrate 9 in the thickness direction (z direction). In this embodiment, the imaging module 4 has the light-receiving surface 5A of the image sensor 5 positioned in the space 9A of the interposer substrate 9. This makes the imaging module 4 thinner compared to, for example, the case where the interposer substrate 9 does not have a space 9A and the light-receiving surface 5A of the image sensor 5 is positioned offset from the interposer substrate 9 in the thickness direction (z direction).

[0033] (Relationship between image sensor 5 and cover member 6) In the imaging module 4 of this embodiment, as described above, the light-receiving surface 5A of the image sensor 5 has a curved shape along the opposing surface 62A of the cover member 6. In this example, the light-receiving surface 5A of the image sensor 5 is spherical in shape, concave along the opposing surface 62A on the side opposite to the cover member 6. In addition, the light-receiving surface 5A is a curved surface in which the curvature in the x direction and the curvature in the y direction are equal.

[0034] In this case, if the light-receiving surface of the image sensor 5 is flat, the focal point of the light incident on the lens may shift from the light-receiving surface, which can cause blurring in the image acquired by the image sensor 5. Figure 5 shows an example of the relationship between light incident on the lens 29 and the light-receiving surface 5E in an image sensor 5 where the light-receiving surface 5E is a plane. Generally, the focal point of light incident on lens 29 is closer to lens 29 the further it is from the optical axis of lens 29. Therefore, as shown in Figure 5, if lens 29 and image sensor 5 are positioned so that the focal point of light incident on lens 29 coincides with the center of the light-receiving surface 5E, the focal point may be shifted from the light-receiving surface 5E at its outer edge. In this case, blurring may occur at the outer edge of the image acquired by image sensor 5.

[0035] One way to suppress blurring at the edges of the image acquired by the image sensor 5 is to increase the number of lenses 21 (see Figure 1) in the lens unit 2 (see Figure 1) and correct the focal point. However, increasing the number of lenses 21 in lens unit 2 would increase the size of the imaging device 1 (see Figure 1). In particular, when the imaging device 1 is used as a camera for a smartphone, there is a great need to make the imaging device 1 smaller and lighter, so increasing the size of the imaging device 1 is undesirable.

[0036] In contrast, in this embodiment, the light-receiving surface 5A of the image sensor 5 is curved so as to be recessed along the opposing surface 62A of the cover member 6, on the side opposite to the cover member 6. As a result, the outer edge of the light-receiving surface 5A of the image sensor 5, which is further away from the optical axis of the lens unit 2, is closer to the lens unit 2. This suppresses the shift in the focal point of light incident on the lens unit 2 from the light-receiving surface 5A at the outer edge of the light-receiving surface 5A. As a result, blurring at the outer edge of the image acquired by the image sensor 5 can be suppressed.

[0037] In particular, in this embodiment, the light-receiving surface 5A of the image sensor 5 is curved along the opposing surface 62A of the cover member 6. In other words, the light-receiving surface 5A and the opposing surface 62A are curved surfaces with equal curvature. As a result, the distance between the light-receiving surface 5A and the opposing surface 62A, and the thickness of the adhesive layer 7, are equal across the entire surface of the light-receiving surface 5A. With this configuration, for example, compared to the case where the light-receiving surface 5A is not aligned with the opposing surface 62A, the light incident on the cover member 6 is more easily focused onto the photoelectric conversion element 511 of the image sensor 5 over the entire area of ​​the light-receiving surface 5A.

[0038] Furthermore, in the imaging module 4 of this embodiment, the light-receiving surface 5A of the image sensor 5 is covered by a cover member 6 with an adhesive layer 7 in between. In the imaging module 4, there is no gap between the light-receiving surface 5A of the image sensor 5 and the cover member 6. As a result, for example, compared to the case where the light-receiving surface 5A of the image sensor 5 is exposed, the adhesion of foreign matter such as dust to the light-receiving surface 5A is suppressed.

[0039] Furthermore, the image sensor 5 is positioned around the light-receiving surface 5A, and the outer periphery of the wiring section 52, on which the electrode pads 521 are formed, faces the base 61 of the cover member 6. The outer periphery of the wiring section 52 is planar, following the flat base 61. As a result, in the imaging module 4, it becomes easier to connect the conductive portion 8 to the electrode pad 521 compared to when the outer circumference of the wiring portion 52 is curved, and poor contact between the electrode pad 521 and the conductive portion 8 is suppressed.

[0040] In the imaging module 4 of this embodiment, the image sensor 5 has an electrode pad 521 as an example of a first conductive part electrically connected to the cover member 6. In addition, in the imaging module 4 of this embodiment, the cover member 6 has wiring 611 as an example of a second conductive part electrically connected to the image sensor 5. The shapes of the first conductive part of the image sensor 5 and the second conductive part of the cover member 6 described above are examples, and their shapes are not particularly limited as long as they can electrically connect the image sensor 5 and the cover member 6. For example, the image sensor 5 may have wiring as an example of a first conductive part, and the cover member 6 may have an electrode pad as an example of a second conductive part.

[0041] (Manufacturing method for imaging module 4) Figures 6(a) and 6(b) show an example of a manufacturing method for the imaging module 4 to which this embodiment is applied. A flat image sensor 5 is used in the manufacture of the imaging module 4. First, as shown in Figure 6(a), an anisotropic conductive film or metal material, which is the material for the conductive portion 8, is loaded onto the electrode pad 521 of the image sensor 5. In this case, an anisotropic conductive film 81 is loaded onto the electrode pad 521. Furthermore, an adhesive 71, which is the material for the adhesive layer 7, is applied to the light-receiving surface 5A of the image sensor 5. Then, the image sensor 5, on which the anisotropic conductive film 81 is loaded and adhesive 71 is applied, is placed on a stage provided in the manufacturing apparatus for the imaging module 4.

[0042] Next, the cover member 6, on which electrodes 65 are provided on the wiring 611, is stacked onto the image sensor 5 on the stage using a collet provided in the manufacturing apparatus for the imaging module 4. At this time, the image sensor 5 and the cover member 6 are stacked so that the terminals of the wiring 611 and the anisotropic conductive film 81 overlap. Furthermore, the image sensor 5 and the cover member 6 are stacked so that the light-receiving surface 5A faces the protruding portion 62 with the adhesive 71 in between.

[0043] Then, the cover member 6 is pressed towards the image sensor 5 via the collet, and the manufacturing apparatus is evacuated. As a result, the image sensor 5 deforms to conform to the cover member 6. More specifically, the light-receiving surface 5A of the image sensor 5 deforms into a curved shape along the opposing surface 62A of the cover member 6.

[0044] Next, the manufacturing apparatus is heated to cure the anisotropic conductive film 81 and the adhesive 71. As a result, a conductive portion 8 is formed as shown in Figure 6(b), and the electrode pads 521 of the image sensor 5 and the wiring 611 of the cover member 6 are connected by the conductive portion 8. In addition, an adhesive layer 7 is formed, and the image sensor 5 and the cover member 6 are integrated by the adhesive layer 7. Based on the above, the imaging module 4 shown in Figure 3, etc., is obtained. Next, the interposer substrate 9 is attached to the cover member 6 via the electrode 65, and the lens unit 2 holding the lens unit 2 is attached, thereby obtaining the imaging device 1 shown in Figure 1.

[0045] [Embodiment 2] Next, Embodiment 2 of the present invention will be described. Note that the same reference numerals are used for components similar to those in Embodiment 1, and detailed explanations are omitted here. Figures 7(a) to 7(c) show an example of the configuration of the imaging module 4 to which Embodiment 2 is applied. Figure 7(a) is a view of the imaging module 4 along the z-direction from the lens unit 2 (see Figure 1) side. Figure 7(b) is a cross-sectional view of the imaging module 4 cut at section VIIB in Figure 7(a), and Figure 7(c) is a cross-sectional view of the imaging module 4 cut at section VIIC in Figure 7(a). Note that the interposer substrate 9 is omitted in Figures 7(a) to (c).

[0046] The imaging module 4 of Embodiment 2 differs from Embodiment 1 in the shape of the protruding portion 62 and the opposing surface 62B of the cover member 6, and the shape of the light-receiving surface 5B of the image sensor 5. In the cover member 6 of Embodiment 2, the shape of the protruding portion 62 when viewed along the z-direction follows the rectangular light-receiving surface 5B, and is a rounded rectangle with the x-direction as the major axis and the y-direction as the minor axis. Similarly, the cross-sectional shape of the protruding portion 62 when cut in the xy-plane is a rounded rectangle with the x-direction as the major axis and the y-direction as the minor axis. Furthermore, the cross-sectional area of ​​the protruding portion 62 when cut in the xy-plane gradually decreases towards the light-receiving surface 5B side.

[0047] As a result, the opposing surface 62B of the protruding portion 62 has a curved shape that protrudes toward the image sensor 5 side. Furthermore, the opposing surface 62B is a curved surface in which the curvature in the x-direction and the curvature in the y-direction are different. More specifically, the opposing surface 62B is a curved surface in which the curvature in the x-direction is smaller than the curvature in the y-direction. In this embodiment, the x and y directions are examples of two orthogonal directions.

[0048] Furthermore, the light-receiving surface 5B of the image sensor 5 is spherical in shape, concave along the opposing surface 62B on the side opposite to the cover member 6. It should also be noted that the light-receiving surface 5B is a curved surface with curvature in the x-direction being smaller than curvature in the y-direction. With this configuration, in the imaging module 4 of this embodiment, the position of the focal point of light incident on the lens unit 2 is suppressed to shift from the light-receiving surface 5B at the outer periphery of the light-receiving surface 5B. As a result, blurring at the outer periphery of the image acquired by the image sensor 5 can be suppressed.

[0049] In this embodiment, the imaging module 4 has a rounded rectangular shape when viewed from the z-direction of the protruding portion 62 of the cover member 6, which conforms to the shape of the light-receiving surface 5B of the image sensor 5. As a result, the width of the cover member 6 in the y-direction is smaller compared to Embodiment 1. This makes it possible to miniaturize the imaging module 4 and the imaging device 1 compared to the imaging module 4 of Embodiment 1, in which the shape of the protruding portion 62 of the cover member 6 when viewed from the z direction is circular.

[0050] [Embodiment 3] Next, Embodiment 3 of the present invention will be described. Note that the same reference numerals are used for components similar to those in Embodiments 1 and 2, and detailed explanations are omitted here. Figures 8(a) to 8(c) show an example of the configuration of the imaging module 4 to which Embodiment 3 is applied. Figure 8(a) is a view of the imaging module 4 along the z-direction from the lens unit 2 (see Figure 1) side. Figure 8(b) is a cross-sectional view of the imaging module 4 cut at section VIIIB in Figure 8(a), and Figure 8(c) is a cross-sectional view of the imaging module 4 cut at section VIIIC in Figure 8(a). Note that the interposer substrate 9 is omitted in Figures 8(a) to (c).

[0051] The imaging module 4 of Embodiment 3 differs from Embodiments 1 and 2 in the shape of the protruding portion 62 and the opposing surface 62C of the cover member 6, and in the shape of the light-receiving surface 5C of the image sensor 5. In the cover member 6 of Embodiment 3, the shape of the protruding portion 62 when viewed along the z direction is rectangular, following the rectangular light-receiving surface 5C, with the x direction being the major axis and the y direction being the minor axis. Furthermore, in the third embodiment, the cover member 6 has a cylindrical surface 62C on the opposing surface 62C that has curvature in the x direction but not in the y direction.

[0052] Furthermore, the light-receiving surface 5C of the image sensor 5 is curved along the opposing surface 62C so as to be concave on the side opposite to the cover member 6. In addition, the light-receiving surface 5C is a cylindrical surface that has curvature in the x direction but no curvature in the y direction. With this configuration, the imaging module 4 of this embodiment suppresses the shift in the focal position of light incident on the lens unit 2 from the light-receiving surface 5C at both ends in the x-direction of the light-receiving surface 5C. This makes it possible to suppress blurring at both ends in the x-direction of the image acquired by the image sensor 5.

[0053] Here, in the image sensor 5, the greater the distance from the optical axis, the more the focal point of the light incident from the lens unit 2 tends to shift towards the lens unit 2. In this embodiment, the light-receiving surface 5C has curvature in the x-direction, which is the long axis of the rectangular shape. This suppresses the shift of the focal point of light incident from the lens unit 2 from the light-receiving surface 5C at both ends of the light-receiving surface 5C in the x-direction, where the distance from the optical axis is large.

[0054] Furthermore, in this embodiment, the cover member 6 has a cylindrical surface shape where the opposing surface 62C has curvature in the x direction but not in the y direction. This makes it easier to mold the cover member 6 compared to the case where it has curvature in both the x and y directions. Furthermore, in the manufacturing of the imaging module 4, when the protruding portion 62 of the cover member 6 is pressed against the light-receiving surface 5C to deform the image sensor 5, the image sensor 5 can be deformed with a smaller pressing force compared to the case where the opposing surface 62C has curvature in both the x and y directions. This makes it easier to manufacture the imaging module 4.

[0055] [Differentiation] Next, we will describe modified versions of the imaging module 4. In the following, we will use the imaging module 4 of Embodiment 1 as an example to describe the modified versions, but each modified version is also applicable to the imaging module 4 of Embodiments 2 and 3. Figures 9(a) and 9(b) show the first and second modified versions of the imaging module 4, respectively.

[0056] As shown in Figures 9(a) to (b), the imaging module 4 may have a curved surface on the side of the cover member 6 opposite to the opposing surface 62A. In other words, the imaging module 4 may have a curved surface on the side of the cover member 6 that is located on the light incidence side and faces the lens 21 (see Figure 1) of the lens unit 2 (see Figure 1). In the first modified example shown in Figure 9(a), the cover member 6 has a curved surface on the opposite side 67, which is the surface opposite to the opposing surface 62A, that protrudes toward the light incident side (light receiving side). Furthermore, in the second modified example of the cover member 6 shown in Figure 9(b), the opposite surface 68, which is the surface opposite to the opposing surface 62A, has a curved surface that is concave downwards.

[0057] The imaging module 4 has curved opposite surfaces 67 and 68 of the cover member 6, and these opposite surfaces 67 and 68 function as lenses that focus the light that passes through the lens unit 2 and enters the cover member 6 onto the photoelectric conversion element 511. This makes it possible to reduce the number of lenses 21 in the lens unit 2, and thus make the imaging device 1 (see Figure 1) smaller and lighter. The shapes of the opposite surfaces 67 and 68 of the cover member 6 can be determined according to the optical characteristics of the lens 21 of the lens unit 2.

[0058] Figures 10(a) and 10(b) show a third and fourth modified example of the imaging module 4, respectively. As shown in Figure 10(a), the imaging module 4 may have a resin layer 11 on the outer circumference of the image sensor 5 to protect the electrode pads 521 arranged along the outer circumference of the image sensor 5. The resin layer 11 is an example of a protective part. The presence of a resin layer 11 in the imaging module 4 suppresses the load on the electrode pads 521 and the electrodes 65 and wiring 611 of the cover member 6 connected to the electrode pads 521. This makes it less likely for disconnections to occur between the image sensor 5 and the cover member 6. For example, epoxy can be used as the resin layer 11.

[0059] Furthermore, as shown in Figure 10(b), the imaging module 4 may further include a heat dissipation member 12 for dissipating heat from the image sensor 5. The heat dissipation member 12 is provided so as to be in contact with the surface of the image sensor 5 opposite to the light-receiving surface 5A. From the viewpoint of heat dissipation efficiency by the heat dissipation member 12, the area of ​​the heat dissipation member 12 is preferably larger than the pixel array portion 51 of the image sensor 5. The imaging module 4, equipped with a heat dissipation member 12, facilitates the dissipation of heat generated by the photoelectric conversion element 511 of the image sensor 5. This suppresses the degradation of image quality acquired by the image sensor 5 due to the temperature rise of the photoelectric conversion element 511. The heat dissipation member 12 is not particularly limited, but can be a metal with high thermal conductivity such as aluminum or copper, a graphite sheet, a Peltier element, etc.

[0060] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above. Various modifications and combinations are permitted as long as they do not contradict the spirit of the present invention. [Explanation of symbols]

[0061] 1...Imaging device, 2...Lens unit, 3...Lens holder, 4...Imaging module, 5...Image sensor, 5A...Light-receiving surface, 6...Cover member, 7...Adhesive layer, 8...Conductive part, 9...Interposer substrate, 11...Resin layer, 12...Heat dissipation member, 21...Lens, 50...Pixel, 51...Pixel array part, 52...Wiring part, 511...Photoelectric conversion element, 512...Color filter, 513...Microlens

Claims

1. An image sensor having a light-receiving surface that receives light, The image sensor comprises a cover member that covers the light-receiving surface, The cover member is curved such that the surface facing the light-receiving surface protrudes toward the image sensor. The image sensor is laminated on the opposing surfaces with an adhesive layer in between, and the light-receiving surface is curved so as to be recessed on the side opposite to the cover member. Imaging module.

2. The imaging module according to claim 1, wherein the image sensor has a light-receiving surface that is curved along the opposing surface of the cover member.

3. The image sensor has electrode pads around the light-receiving surface, The cover member has wiring connected to the electrode pads around the periphery of the opposing surface. The imaging module according to claim 1.

4. The imaging module according to claim 3, further comprising an interposer substrate connected to the wiring of the cover member, wherein a space is formed in the center on which at least the light-receiving surface of the image sensor is arranged.

5. The imaging module according to claim 3, wherein the electrode pads of the image sensor and the wiring of the cover member are connected by at least one of an anisotropic conductive film or bumps.

6. The imaging module according to claim 3, having a protective portion arranged on the outer periphery of the image sensor to protect the electrode pads.

7. The imaging module according to claim 1, wherein the difference between the refractive index of the cover member and the refractive index of the adhesive layer is 0.2 or less.

8. The image sensor includes the microlenses on the light-receiving surface, The refractive index of the adhesive layer is smaller than the refractive index of the microlens. The imaging module according to claim 7.

9. The imaging module according to claim 1, further comprising a heat dissipation member on the side of the image sensor opposite to the light-receiving surface for dissipating heat from the image sensor.

10. The imaging module according to claim 1, wherein the cover member has a curved surface on the side opposite to the opposing surface.

11. The imaging module according to claim 1, wherein the curved surfaces formed on the light-receiving surface of the image sensor and the opposing surface of the cover member have curvature in two orthogonal directions, and the curvatures are different.

12. The imaging module according to claim 1, wherein the curved surfaces formed on the light-receiving surface of the image sensor and the opposing surface of the cover member have curvature in only one of two orthogonal directions.

13. An imaging module according to any one of claims 1 to 12, The image sensor has a light-gathering lens on the light-receiving surface, A retaining member that holds the lens and An imaging device equipped with the following features.

14. The imaging apparatus according to claim 13, wherein the holding member is attached to the cover member.

Images