Imaging element unit and camera device

Abstract

The present invention provides an imaging element unit capable of preventing warping of an imaging element and improving the quality of image pickup, and an imaging device having the imaging element unit. A packaging body (2) comprises: a flat portion (2a) on which an imaging element chip (1) is fixed; a wall portion (2b) surrounding a fixing surface (2d) of the imaging element chip (1) in the flat portion (2a); and a plurality of first terminals electrically connected to the imaging element chip (1). A protective cover (3) seals the imaging element chip (1) in a state overlapping with the wall portion (2b). A conductive component (7) is provided between a first terminal exposed from the back side (2e) of the packaging body (2) and a second terminal formed on a circuit board (52) arranged opposite to the back side (2e) of the packaging body (2). The conductive component (7) is used to fix the packaging body (2) and the circuit board (52) and to electrically connect the first terminal and the second terminal. The protective cover (3) and the wall portion (2b) are fixed by an adhesive (4) having a Young's modulus of 500 MPa or more.

Description

Technical Field

[0001] The present invention relates to an imaging element unit and a camera device. Background Art

[0002] With the increasing resolution of imaging elements such as CCD (Charge Coupled Device) image sensors and CMOS (Complementary Metal Oxide Semiconductor) image sensors, the demand for information devices with imaging capabilities, such as digital cameras, digital video cameras, mobile phones such as smartphones, tablet computers, and endoscopes, is rapidly increasing. These electronic devices with imaging capabilities are referred to as imaging devices.

[0003] The imaging device includes an imaging unit including an imaging element chip as a semiconductor chip, a package that accommodates the imaging element chip, and a circuit board on which the package is mounted.

[0004] Patent Documents 1 to 3 disclose the structure of a unit including an electronic component, a package for accommodating the electronic component, and a circuit board to which the package is mounted.

[0005] Previous technical literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2009-176961

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2011-071422

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 2015-038996 Summary of the Invention

[0010] Technical issues to be solved by the invention

[0011] When mounting a package containing a semiconductor chip on a circuit board, the unit is exposed to high temperatures during the process of electrically connecting the package and the circuit board using solder. After this process, if the unit temperature drops, warping due to the bimetallic effect may occur due to differences in the linear expansion coefficients of the unit's components.

[0012] When the semiconductor chip is an imaging element chip, warping caused by the bimetallic effect can prevent the flatness of the imaging element chip's light-receiving surface. This warping can cause focal length to deviate around the periphery of the light-receiving surface, impacting image quality. Countermeasures against warping caused by the bimetallic effect become particularly important when the imaging element chip is large. Patent Documents 1-3 do not address this issue of warping in imaging element chips.

[0013] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an imaging element unit capable of preventing warping of an imaging element chip and improving image quality, and an imaging device including the imaging element unit.

[0014] Means for solving technical problems

[0015] The imaging element unit of the present invention is fixed to a circuit board via a conductive component, and the imaging element unit comprises: a fixing component having a flat portion to which an imaging element chip is fixed, a wall portion surrounding the fixing surface of the imaging element chip in the flat portion, and a plurality of first terminals electrically connected to the imaging element chip, and having a linear expansion coefficient smaller than the linear expansion coefficient of the circuit board to which the imaging element unit is fixed; and a sealing component for sealing the imaging element chip in a state overlapping with the wall portion, the sealing component and the wall portion being fixed by an adhesive with a Young's modulus of 500 MPa or more.

[0016] Alternatively, the imaging element unit of the present invention is fixed to a circuit board via a conductive component, and the imaging element unit comprises: a fixing component having a flat portion to which an imaging element chip is fixed, a wall portion surrounding the fixing surface of the imaging element chip in the flat portion, and a plurality of first terminals electrically connected to the imaging element chip, and the linear expansion coefficient is smaller than the linear expansion coefficient of the circuit board to which the imaging element unit is fixed; and a sealing component for sealing the imaging element chip in a state overlapping with the wall portion, the sealing component and the wall portion being fixed by an adhesive having a Young's modulus of less than 500 MPa and a thickness of less than 15 μm.

[0017] The camera device of the present invention comprises: the above-mentioned imaging element unit; the above-mentioned circuit board; and a conductive component, which is arranged between the above-mentioned first terminal and the second terminal, and fixes the above-mentioned fixing component to the above-mentioned circuit board and electrically connects the above-mentioned first terminal to the above-mentioned second terminal. The above-mentioned first terminal is exposed from the surface of the above-mentioned fixing component on the side opposite to the above-mentioned fixing surface, and the above-mentioned second terminal is formed on the above-mentioned circuit board and is arranged opposite to the surface of the above-mentioned fixing component on the side opposite to the above-mentioned fixing surface.

[0018] Effects of the Invention

[0019] According to the present invention, there are provided an imaging element unit capable of preventing warping of an imaging element and improving the quality of captured images, and an imaging apparatus including the imaging element unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 1 is a diagram showing a schematic configuration of a digital camera 100 as one embodiment of an imaging device according to the present invention.

[0021] Figure 2 is viewed from the circuit board 52 side Figure 1 FIG. 1 is a rear view of the image pickup unit 50 in the digital camera 100 shown.

[0022] Figure 3 yes Figure 2 FIG. 5 is a schematic cross-sectional view of the imaging unit 50 taken along line AA.

[0023] Figure 4 is viewed from the imaging element unit 51 side along the direction Z Figure 2 A front view of the camera unit 50 is shown.

[0024] Figure 5 Graphs showing the results of simulating the warpage of the imaging element chip 1 in the image pickup unit 50 for each combination of the thickness of the adhesive 4 and the Young's modulus (500 MPa and 5000 MPa).

[0025] Figure 6 Graphs showing the results of simulating the warpage of the imaging element chip 1 in the image pickup unit 50 for each combination of the thickness of the adhesive 4 and the Young's modulus (50 MPa).

[0026] Figure 7 1 is a diagram showing the results of simulating the warping amount of the imaging element chip 1 in the image pickup unit 50 for each bonding width of the adhesive 4 (thickness = 15 μm, Young's modulus = 5000 MPa).

[0027] Figure 8 1 is a diagram showing the results of simulating the warpage of the imaging element chip 1 in the image pickup unit 50 for each bonding width of the adhesive 4 (thickness = 60 μm, Young's modulus = 500 MPa).

[0028] Figure 9 1 is a diagram showing the results of simulating the warping amount of the imaging element chip 1 in the imaging unit 50 for each overlap ratio. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0030] Figure 11 is a diagram showing a schematic configuration of a digital camera 100 as one embodiment of an imaging device according to the present invention.

[0031] Figure 1 The illustrated digital camera 100 includes a lens apparatus 40 having an imaging lens 41 , an aperture 42 , a lens driving section 43 , an aperture driving section 44 , and a lens control section 45 .

[0032] The lens device 40 may be detachable from the main body of the digital camera 100 or may be integrated with the main body of the digital camera 100 .

[0033] The imaging lens 41 includes a focus lens or a zoom lens that is movable in the optical axis direction, etc. The imaging lens 41 and the aperture 42 constitute an imaging optical system.

[0034] The lens control unit 45 of the lens apparatus 40 is configured to be able to communicate with the system control unit 11 of the digital camera 100 in a wired or wireless manner.

[0035] The lens control unit 45 drives the focus lens included in the imaging lens 41 via the lens driving unit 43 to change the position of the principal point of the focus lens according to a command from the system control unit 11 , or controls the opening amount of the diaphragm 42 via the diaphragm driving unit 44 .

[0036] The digital camera 100 further includes an imaging unit 50 for capturing an image of a subject using an imaging optical system, a system control unit 11 , and an operation unit 14 .

[0037] The imaging unit 50 includes an imaging element unit 51 such as a CCD image sensor or a CMOS image sensor, and a circuit board 52. The imaging element unit 51 is fixed to the circuit board 52 via a conductive member 7 to be described later.

[0038] The imaging element unit 51 has a light receiving surface (described later) on which a plurality of pixels are arranged two-dimensionally. Figure 3 The light receiving surface 10) is formed by the imaging optical system and the subject image is converted into an electrical signal (pixel signal) by the plurality of pixels and outputted.

[0039] The system control section 11 drives the imaging element unit 51 and outputs a subject image captured by the imaging optical system of the lens apparatus 40 as a captured image signal.

[0040] An instruction signal from the user is input to the system control unit 11 through the operation unit 14 .

[0041] The system control unit 11 comprehensively controls the entire digital camera 100 , and its hardware configuration includes various processors that execute programs to perform processing.

[0042] Various processors include general-purpose processors such as CPUs (Central Processing Units) that execute programs to perform various processes, FPGAs (Field Programmable Gate Arrays) and other processors whose circuit structures can be changed after manufacturing, such as programmable logic devices (PLDs) or ASICs (Application Specific Integrated Circuits), which are processors with circuit structures specifically designed to perform specific processes, such as dedicated circuits.

[0043] More specifically, the various processors are configured as circuits formed by combining circuit elements such as semiconductor elements.

[0044] The system control unit 11 may be configured by one of various processors, or may be configured by a combination of two or more processors of the same or different types (for example, a combination of a plurality of FPGAs or a combination of a CPU and an FPGA).

[0045] In addition, the electronic control system of the digital camera 100 includes a main memory 16 composed of RAM (Random Access Memory), a memory control unit 15 that controls data storage in the main memory 16 and data reading from the main memory 16, a digital signal processing unit 17 that performs digital signal processing on the camera image signal output from the camera unit 50 to generate camera image data in various formats such as the JPEG (Joint Photographic Experts Group) format, an external memory control unit 20 that controls data storage in a storage medium 21 and data reading from the storage medium 21, a display unit 23 composed of an organic EL (electroluminescence) display or a liquid crystal display, and a display control unit 22 that controls the display of the display unit 23.

[0046] Figure 2 is viewed from the circuit board 52 side Figure 1 FIG. 1 is a rear view of the image pickup unit 50 in the digital camera 100 shown. Figure 3 yes Figure 2 FIG. 5 is a schematic cross-sectional view of the imaging unit 50 taken along line AA.

[0047] like Figure 3 As shown, the imaging unit 50 includes an imaging element unit 51 and a circuit board 52 fixedly mounted on the back surface of the imaging element unit 51 .

[0048] The imaging element unit 51 includes a package 2 having a flat portion 2a, such as a rectangular plate or a circular plate, and a frame-shaped wall portion 2b, such as a rectangular frame or a circular frame, perpendicularly disposed at the end of the flat portion 2a. The package 2 has a structure in which a recess 2c is formed by the flat portion 2a and the wall portion 2b.

[0049] The imaging element unit 51 further includes an imaging element chip 1 fixed to the fixing surface 2d of the flat portion 2a of the package 2, and a protective cover 3 made of a light-transmitting member such as resin or glass. The protective cover 3 is fixed to the upper surface of the wall portion 2b of the package 2 with an adhesive 4, sealing the recessed portion 2c of the package 2 and thereby encapsulating the imaging element chip 1. The package 2 constitutes the fixing member, and the protective cover 3 constitutes the sealing member. The wall portion 2b is configured to surround the fixing surface 2d of the imaging element chip 1 in the flat portion 2a.

[0050] The imaging element chip 1 is a semiconductor chip including a photoelectric conversion element such as a photodiode and a light receiving surface 10. The light receiving surface 10 is provided with a readout circuit for converting the charge accumulated in the photoelectric conversion element into a signal and reading it out. Figure 2 As shown, the imaging element chip 1 has a rectangular planar shape and is fixed to the fixing surface 2d of the package 2 by an adhesive member 5 such as a resin serving as a die bond material. The imaging element chip 1 is, for example, a medium format sensor (43.8 mm x 32.9 mm, for example).

[0051] exist Figure 3 , a direction Z perpendicular to the light receiving surface 10 of the imaging element chip 1 and a direction X as the longitudinal direction of the imaging element chip 1 are shown. Figure 2 , a direction Y as the short side direction of the imaging element chip 1 is shown. Figure 2 This is a diagram of the imaging unit 50 as viewed from the circuit board 52 side in the direction Z. The direction X and the direction Y are directions parallel to the light receiving surface 10 .

[0052] The package 2 may be made of an insulating material such as alumina ceramics (ceramics) or a multilayered package having a conductive layer made of a conductive member such as tungsten and an insulating layer made of an insulating material such as alumina ceramics.

[0053] A plurality of terminals (not shown) are formed on the fixing surface 2d of the recessed portion 2c of the package body 2. These terminals are electrically connected to electrode pads formed on the imaging element chip 1 via conductive wires (not shown). Furthermore, first terminals (not shown) electrically connected to the terminals formed on the fixing surface 2d of the recessed portion 2c of the package body 2 are exposed on the back surface 2e of the package body 2, opposite to the side to which the protective cover 3 is fixed.

[0054] The circuit board 52 is connected to the circuit board 52 by a plurality of conductive components 7 (refer to Figure 3 ) is bonded and fixed to the back surface 2e of the package body 2. The conductive member 7 is in contact with the plurality of first terminals exposed on the back surface 2e of the package body 2, respectively.

[0055] exist Figure 2 In the illustrated example, the circuit board 52 is a frame-shaped, plate-like component with an opening 52k in the center. Circuits for driving the imaging element chip 1 and processing signals output from the imaging element chip 1 are formed on the circuit board 52. Terminals for these circuits (second terminals (not shown)) are formed on the surface 52a of the circuit board 52, which is fixed to the package 2, at locations in contact with the conductive member 7.

[0056] Therefore, the second terminal of the circuit included in the circuit board 52 and the first terminal formed on the back surface of the package 2 are electrically connected via the conductive member 7 .

[0057] Circuit board 52 includes an insulating layer made of glass epoxy resin, a conductive layer made of copper, and a solder resist layer, but other well-known circuit boards can also be used. Circuit board 52 uses a circuit board with a linear expansion coefficient greater than that of package 2.

[0058] like Figure 2 As shown, the conductive member 7 is arranged in the region 7A indicated by the dotted line in a frame-like planar shape. The conductive member 7 can be made of any conductive material having an adhesive function, such as solder composed of an alloy of lead and tin or solder composed of an alloy of tin and copper.

[0059] Figure 4 is viewed from the imaging element unit 51 side along the direction Z Figure 2 The front view of the camera unit 50 is shown. Figure 4 Omitted Figure 3 An illustration of the protective cover 3 is shown.

[0060] like Figure 4 As shown, the outer edge of the region 7A where the conductive member 7 for fixing and electrically connecting the circuit board 52 and the package 2 is formed overlaps with the wall portion 2 b of the package 2 .

[0061] Specifically, the outer edge of region 7A is formed by edge EX1 on one side of region 7A in direction X, edge EX2 on the other side of region 7A in direction X, edge EY1 on one side of region 7A in direction Y, and edge EY2 on the other side of region 7A in direction Y. Furthermore, these edges EX1, EX2, EY1, and EY2 are all located at positions overlapping with wall 2b of package 2. The linear expansion coefficients of circuit board 52 and package 2 can be calculated, for example, by measuring the dimensional changes of each circuit board 52 and package 2 when the external temperature changes, and converting these dimensional changes into dimensional change rates per unit temperature.

[0062] In the camera unit 50, the linear expansion coefficient of the package 2 bonded to the circuit board 52 is smaller than that of the circuit board 52. Therefore, stress is applied to the package 2 due to the bimetallic effect after the circuit board 52 and the package 2 are bonded via the conductive member 7.

[0063] like Figure 4 As shown, if the outer edge of region 7A overlaps wall 2b, stress applied from circuit board 52 to package 2 is dispersed through wall 2b to protective cover 3. As a result, warping of package 2 is reduced, thereby reducing warping of imaging element chip 1.

[0064] like Figure 4 As shown, the distance between the edge EX1 of region 7A and the end EX3 of the wall 2b portion overlapping with the edge EX1 in the direction X on the side of the recess 2c (imaging element chip 1 side) is set to L1, and the width of the wall 2b portion overlapping with the edge EX1 in the direction X is set to XD1. L1 = α1 × (XD1).

[0065] like Figure 4 As shown, the distance between the edge EX2 of the region 7A and the end EX4 of the wall 2b portion overlapping with the edge EX2 in the direction X on the side of the recess 2c is set to L2, and the width of the wall 2b portion overlapping with the edge EX2 in the direction X is set to XD2. Let L2 = α2 × (XD2).

[0066] like Figure 4 As shown, the distance between edge EY1 of region 7A and end EY3 of the portion of wall 2b overlapping edge EY1 on the concave portion 2c side in direction Y is defined as L3, and the width of the portion of wall 2b overlapping edge EY1 in direction Y is defined as YD1. L3 = α3 × (YD1).

[0067] like Figure 4As shown, the distance between edge EY2 of region 7A and end EY4 of the portion of wall 2b overlapping edge EY2 on the concave portion 2c side in direction Y is defined as L4, and the width of the portion of wall 2b overlapping edge EY2 in direction Y is defined as YD2. L4 = α4 × (YD2).

[0068] Furthermore, the distances L1 and L2 may be the same value or different values. Furthermore, the distances L3 and L4 may be the same value or different values. Furthermore, the distances L1 to L4 may be different values.

[0069] α1, α2, α3, and α4 are ratios (overlapping ratios) of the distance between the position of the wall portion 2b overlapping with the outer edge of the region 7A and the end of the wall portion 2b on the recessed portion 2c side, relative to the width of the wall portion 2b.

[0070] The inventors found that, for example, when α1, α2, α3 and α4 are respectively set to 0.6 (overlap rate = 60%), by using an adhesive with a Young's modulus (longitudinal elastic modulus) of 500 MPa (megapascals) or more as the adhesive 4 for fixing the packaging body 2 and the protective cover 3 to each other, the warping of the imaging element chip 1 can be reduced to a practically acceptable level.

[0071] Figure 5 Graphs showing the results of simulating the warpage of the imaging element chip 1 in the image pickup unit 50 for each combination of the thickness of the adhesive 4 and the Young's modulus (500 MPa and 5000 MPa). Figure 5 The simulation results are obtained when α1, α2, α3, and α4 are each set to 0.6 (overlap ratio = 60%) and the bonding width of the adhesive 4 is set to 4 mm.

[0072] Here, the adhesive is arranged with a width of X mm along the portion where the wall portion 2 b overlaps the protective cover 3 when viewed from the direction Z perpendicular to the light receiving surface 10 of the imaging element chip 1 . This is expressed as setting the adhesive width of the adhesive 4 to X mm.

[0073] exist Figure 5 The vertical axis shows the warpage (μm) of the light receiving surface 10 of the imaging element chip 1. This warpage is a value when the optical axis center of the light receiving surface 10 of the imaging element chip 1 intersecting the optical axis of the imaging lens 41 is set as a reference position.

[0074] exist Figure 5 The horizontal axis shows the distance from the optical axis center of the light-receiving surface 10 in image height (%) when the imaging element chip is a medium format (43.8 mm × 32.9 mm). The optical axis center of the light-receiving surface 10 is defined as image height = 0%, and the position on the light-receiving surface 10 farthest from the optical axis center is defined as image height = 100%.

[0075] Figure 5 The graph of “joining thickness 15 μm_E500 MPa” shows the simulation results in a state where the thickness of the adhesive 4 is set to 15 μm and the Young's modulus of the adhesive 4 is set to 500 MPa.

[0076] Figure 5 The graph of “joining thickness 15 μm_E5000 MPa” shows the simulation results in a state where the thickness of the adhesive 4 is set to 15 μm and the Young's modulus of the adhesive 4 is set to 5000 MPa.

[0077] Figure 5 The graph of “joining thickness 30 μm_E500 MPa” shows the simulation results in a state where the thickness of the adhesive 4 is set to 30 μm and the Young's modulus of the adhesive 4 is set to 500 MPa.

[0078] Figure 5 The curve of “joining thickness 30 μm_E5000 MPa” shows the simulation results in a state where the thickness of the adhesive 4 is set to 30 μm and the Young's modulus of the adhesive 4 is set to 5000 MPa.

[0079] Figure 5 The graph of “joining thickness 60 μm_E500 MPa” shows the simulation results in a state where the thickness of the adhesive 4 is set to 60 μm and the Young's modulus of the adhesive 4 is set to 500 MPa.

[0080] Figure 5 The graph of “joining thickness 60 μm_E5000 MPa” shows the simulation results in a state where the thickness of the adhesive 4 is set to 60 μm and the Young's modulus of the adhesive 4 is set to 5000 MPa.

[0081] Figure 5 The curve of “joining thickness 120 μm_E500 MPa” shows the simulation results in a state where the thickness of the adhesive 4 is set to 120 μm and the Young's modulus of the adhesive 4 is set to 500 MPa.

[0082] Figure 5 The curve of “joining thickness 120 μm_E5000 MPa” shows the simulation results in a state where the thickness of the adhesive 4 is set to 120 μm and the Young's modulus of the adhesive 4 is set to 5000 MPa.

[0083] Figure 5 Graphs showing the results of simulating the warpage of the imaging element chip 1 in the image pickup unit 50 for each combination of the thickness of the adhesive 4 and the Young's modulus (50 MPa). Figure 5The simulation results are obtained when α1, α2, α3, and α4 are each set to 0.6 (overlap ratio = 60%) and the bonding width of the adhesive 4 is set to 4 mm. Figure 6 The vertical and horizontal axes are shown with Figure 5 The vertical and horizontal axes shown are the same.

[0084] Figure 6 The graph of “joining thickness 15 μm_E50 MPa” shows the simulation results in a state where the thickness of the adhesive 4 is set to 15 μm and the Young's modulus of the adhesive 4 is set to 50 MPa.

[0085] Figure 6 The graph of “joining thickness 30 μm_E50 MPa” shows the simulation results in a state where the thickness of the adhesive 4 is set to 30 μm and the Young's modulus of the adhesive 4 is set to 50 MPa.

[0086] Figure 6 The graph of “joining thickness 60 μm_E50 MPa” shows the simulation results in a state where the thickness of the adhesive 4 is set to 60 μm and the Young's modulus of the adhesive 4 is set to 50 MPa.

[0087] Figure 6 The graph of “joining thickness 120 μm_E50 MPa” shows the simulation results in a state where the thickness of the adhesive 4 is set to 120 μm and the Young's modulus of the adhesive 4 is set to 50 MPa.

[0088] Depend on Figure 5 and Figure 6 The simulation results show that by setting the Young's modulus of the adhesive 4 to 500 MPa or 5000 MPa, the warpage of the imaging element chip 1 can be suppressed to 60 μm or less at an image height of 80%, regardless of the thickness of the adhesive 4. This warpage allows image quality to be maintained even for large sensors such as medium format sensors.

[0089] And, by Figure 5 and Figure 6 The simulation results shown show that, when the thickness of the adhesive 4 and the bonding width of the adhesive 4 are the same, the higher the Young's modulus of the adhesive 4 is, the more the warping of the imaging element chip 1 can be suppressed.

[0090] Therefore, by setting the Young's modulus of adhesive 4 to 500 MPa or higher, the warpage of the imaging element chip 1 can be suppressed to less than 60 μm at an image height of 80%. This allows image quality to be maintained even when the imaging element chip 1 is a large sensor such as a medium format sensor. Thus, by using a highly rigid adhesive as adhesive 4, warpage of the imaging element chip 1 can be suppressed. For example, Cemedine EP171 can be used as a highly rigid adhesive with a Young's modulus of 500 MPa or higher, while a general adhesive such as Cemedine EP811 (Cemedine is a registered trademark) can be used as a highly rigid adhesive with a Young's modulus of 5000 MPa or higher.

[0091] And, in Figure 5 In the simulation results shown, when the thickness of the adhesive 4 is 120 μm, the warpage of the imaging element chip 1 is suppressed to 60 μm or less at an image height of 80%. Figure 5 The simulation results show that, when the Young's modulus of adhesive 4 and the bonding width of adhesive 4 are the same, the smaller the thickness of adhesive 4, the more the warping of imaging element chip 1 can be suppressed. Therefore, when the Young's modulus of adhesive 4 is set to 500 MPa or higher, the thickness of adhesive 4 is preferably set to 120 μm or less.

[0092] And, as mentioned above, Figure 5 The simulation results shown are those when the bonding width of the adhesive 4 is 4 mm. Figure 7 and Figure 8 The simulation results show that, when the Young's modulus of adhesive 4 and the thickness of adhesive 4 are the same, the greater the bonding width of adhesive 4, the more the warping of imaging element chip 1 can be suppressed. Therefore, when the Young's modulus of adhesive 4 is set to 500 MPa or greater, the bonding width of adhesive 4 is preferably set to 4 mm or greater.

[0093] And, by Figure 6 The simulation results shown in FIG. 4 show that even if the Young's modulus of the adhesive 4 is 50 MPa, which is less than 500 MPa, the warpage of the imaging element chip 1 can be suppressed to 60 μm or less at an image height of 80% if the thickness of the adhesive 4 is 15 μm. Figure 6 The simulation results shown show that the smaller the thickness of the adhesive 4 is, the more the warping of the imaging element chip 1 can be suppressed.

[0094] Therefore, even if the Young's modulus of the adhesive 4 is less than 500 MPa, by setting the thickness of the adhesive 4 to 15 μm or less, the warpage of the imaging element chip 1 can be suppressed to 60 μm or less at an image height of 80%. This allows image quality to be maintained even for large sensors such as medium format imaging element chip 1. In this way, when the adhesive 4 is a low-rigidity adhesive (such as a UV (Ultra Violet) adhesive), the warpage of the imaging element chip 1 can be suppressed by reducing the thickness of the adhesive 4.

[0095] And, as mentioned above, Figure 6 The simulation results shown are for a 4 mm bonding width of the adhesive 4. As mentioned above, a larger bonding width of the adhesive 4 can suppress warping of the imaging element chip 1. Therefore, when the Young's modulus of the adhesive 4 is set to less than 500 MPa and the thickness of the adhesive 4 is set to 15 μm or less, the bonding width of the adhesive 4 is preferably set to 4 mm or greater.

[0096] Figure 7 1 is a diagram showing the results of simulating the warping amount of the imaging element chip 1 in the image pickup unit 50 for each bonding width of the adhesive 4 (thickness = 15 μm, Young's modulus = 5000 MPa). Figure 7 The simulation results are the simulation results when the above-mentioned α1, α2, α3 and α4 are each set to 0.6 (overlap ratio = 60%). Figure 7 The vertical and horizontal axes are shown with Figure 5 The vertical and horizontal axes shown are the same.

[0097] Figure 7 The graph of “joining thickness 15 μm_E 5000 MPa_bonding width 4 mm” shows simulation results when the thickness of the adhesive 4 is set to 15 μm, the Young's modulus of the adhesive 4 is set to 5000 MPa, and the bonding width of the adhesive 4 is set to 4 mm.

[0098] Figure 7 The graph of “joining thickness 15 μm_E 5000 MPa_bonding width 3 mm” shows simulation results when the thickness of the adhesive 4 is set to 15 μm, the Young's modulus of the adhesive 4 is set to 5000 MPa, and the bonding width of the adhesive 4 is set to 3 mm.

[0099] Figure 7 The graph of “joining thickness 15 μm_E 5000 MPa_bonding width 2 mm” shows simulation results when the thickness of the adhesive 4 is set to 15 μm, the Young's modulus of the adhesive 4 is set to 5000 MPa, and the bonding width of the adhesive 4 is set to 2 mm.

[0100] Figure 7The graph of “joining thickness 15 μm_E 5000 MPa_bonding width 1 mm” shows simulation results when the thickness of the adhesive 4 is 15 μm, the Young's modulus of the adhesive 4 is 5000 MPa, and the bonding width of the adhesive 4 is 1 mm.

[0101] Depend on Figure 7 The simulation results show that if the Young's modulus of the adhesive 4 is 5000 MPa, the warpage of the imaging element chip 1 can be suppressed to 60 μm or less at an image height of 80%, regardless of the bonding width of the adhesive 4. Furthermore, as described above, the higher the Young's modulus of the adhesive 4, the more the warpage of the imaging element chip 1 can be suppressed.

[0102] Therefore, by setting the Young's modulus of the adhesive 4 to 5000 MPa or more, the warping of the imaging element chip 1 can be suppressed to 60 μm or less at an image height of 80%, thereby maintaining image quality even when the imaging element chip 1 is a large sensor such as a medium format sensor.

[0103] And, in Figure 7 The simulation results shown show that when the adhesive 4 has a bonding width of 1 mm, the warpage of the imaging element chip 1 is suppressed to 60 μm or less at an image height of 80%. Furthermore, as mentioned above, the larger the bonding width of the adhesive 4, the more the warpage of the imaging element chip 1 is suppressed. Therefore, when the Young's modulus of the adhesive 4 is set to 5000 MPa or higher, it is preferable to set the bonding width of the adhesive 4 to 1 mm or more. However, it is generally difficult to reduce the bonding width of the adhesive 4 to less than 1 mm.

[0104] And, in Figure 7 The simulation results shown show that when the adhesive 4 has a thickness of 15 μm, the warpage of the imaging element chip 1 is suppressed to 60 μm or less at an image height of 80%, regardless of the adhesive 4's bonding width. Furthermore, as mentioned above, the smaller the thickness of the adhesive 4, the more the warpage of the imaging element chip 1 can be suppressed. Therefore, when the Young's modulus of the adhesive 4 is set to 5000 MPa or higher, the thickness of the adhesive 4 is preferably set to 15 μm or less.

[0105] Figure 8 1 is a diagram showing the results of simulating the warpage of the imaging element chip 1 in the image pickup unit 50 for each bonding width of the adhesive 4 (thickness = 60 μm, Young's modulus = 500 MPa). Figure 8 The simulation results are the simulation results when the above-mentioned α1, α2, α3 and α4 are each set to 0.6 (overlap ratio = 60%). Figure 8 The vertical and horizontal axes are shown with Figure 5 The vertical and horizontal axes shown are the same.

[0106] Figure 8 The graph of “joining thickness 60 μm_E 500 MPa_bonding width 4 mm” shows simulation results when the thickness of the adhesive 4 is 60 μm, the Young's modulus of the adhesive 4 is 500 MPa, and the bonding width of the adhesive 4 is 4 mm.

[0107] Figure 8 The graph of “joining thickness 60 μm_E 500 MPa_bonding width 3 mm” shows simulation results when the thickness of the adhesive 4 is set to 60 μm, the Young's modulus of the adhesive 4 is set to 500 MPa, and the bonding width of the adhesive 4 is set to 3 mm.

[0108] Figure 8 The graph of “joining thickness 60 μm_E 500 MPa_bonding width 2 mm” shows simulation results when the thickness of the adhesive 4 is set to 60 μm, the Young's modulus of the adhesive 4 is set to 500 MPa, and the bonding width of the adhesive 4 is set to 2 mm.

[0109] Figure 8 The graph of “joining thickness 60 μm_E 500 MPa_bonding width 1 mm” shows simulation results when the thickness of the adhesive 4 is 60 μm, the Young's modulus of the adhesive 4 is 500 MPa, and the bonding width of the adhesive 4 is 1 mm.

[0110] Depend on Figure 8 The simulation results show that when the Young's modulus of the adhesive 4 is 500 MPa, which is less than 5000 MPa, and the adhesive 4 has a bonding width of 3 mm or 4 mm, the warpage of the imaging element chip 1 can be suppressed to 60 μm or less at an image height of 80%. Furthermore, as mentioned above, the larger the bonding width of the adhesive 4, the more the warpage of the imaging element chip 1 can be suppressed.

[0111] Therefore, when the Young's modulus of the adhesive 4 is less than 5000 MPa, by setting the bonding width of the adhesive 4 to more than 3 mm, the warping of the imaging element chip 1 can be suppressed to less than 60 μm at image height = 80%, and the image quality can be maintained even if the imaging element chip 1 is a large sensor such as a medium format size.

[0112] And, in Figure 8The simulation results shown show that when the adhesive 4 has a thickness of 60 μm, the warpage of the imaging element chip 1 is suppressed to 60 μm or less at an image height of 80% for bonding widths of 3 mm and 4 mm. Furthermore, as mentioned above, the smaller the thickness of the adhesive 4, the more the warpage of the imaging element chip 1 is suppressed. Therefore, when the Young's modulus of the adhesive 4 is set to less than 5000 MPa and the bonding width of the adhesive 4 is set to 3 mm or more, the thickness of the adhesive 4 is preferably set to 60 μm or less.

[0113] The above conditions related to the adhesive 4 are described when α1, α2, α3, and α4 are 0.6, that is, the overlap rate is 60%. However, even when the overlap rate is not 60%, the above conditions related to the adhesive 4 can be used. Figure 9 Provide explanation.

[0114] Figure 9 1 is a diagram showing the results of simulating the warping amount of the imaging element chip 1 in the imaging unit 50 for each overlap ratio. Figure 9 The vertical and horizontal axes are shown with Figure 5 The vertical and horizontal axes shown are the same.

[0115] Figure 9 The curve “No Overlap 1” shown shows the simulation result in a state where the outer edge portion of the region 7A overlaps with the fixing surface 2 d rather than with the wall portion 2 b .

[0116] Figure 9 The curve of "No Overlap 2" shown shows the simulation result in a state where the outer edge of region 7A overlaps with the fixing surface 2d instead of the wall 2b, and the outer edge of region 7A is located closer to the wall 2b compared to the case of "No Overlap 1".

[0117] Figure 9 The “overlap 0%” curve shows simulation results in a state where the outer edge of the region 7A overlaps the end of the wall 2b on the recess 2c side (a state where α1, α2, α3, and α4 are all 0).

[0118] Figure 9 The curve of "10% overlap" shows the simulation results in a state where the outer edge of the region 7A overlaps with the wall portion 2b and the above-mentioned α1, α2, α3, and α4 are all 0.1.

[0119] Figure 9 The curve of "20% overlap" shows the simulation results in a state where the outer edge of the region 7A overlaps with the wall portion 2b and the above-mentioned α1, α2, α3, and α4 are all 0.2.

[0120] Figure 9The curve of "60% overlap" shows the simulation result in a state where the outer edge of the region 7A overlaps with the wall portion 2b and the above-mentioned α1, α2, α3 and α4 are all 0.6.

[0121] Figure 9 The curve of "80% overlap" shows the simulation result in a state where the outer edge of the region 7A overlaps with the wall portion 2b and the above-mentioned α1, α2, α3 and α4 are all 0.8.

[0122] Figure 9 The "overlap 100%" curve shows the simulation results in a state where the outer edge of region 7A overlaps the end of wall 2b on the opposite side to recess 2c (a state where α1, α2, α3, and α4 are all 1.0).

[0123] according to Figure 9 The simulation results shown show that the warping amount of the imaging element chip 1 can be reduced by overlapping the outer edge portion of the region 7A with the wall portion 2 b .

[0124] And, by Figure 9 The results shown here show that the warpage of the imaging element chip 1 is not limited to the case where α1, α2, α3, and α4 are each 0.6 (overlap ratio = 60%). If α1, α2, α3, and α4 are each 0.2 or greater and 1.0 or less, the warpage of the imaging element chip 1 can be reduced to approximately 60 μm at an image height of 80%. Furthermore, it is found that if α1, α2, α3, and α4 are each within the range of 0.2 or greater and 0.6 or less, the warpage of the imaging element chip 1 can be further reduced. Therefore, α1, α2, α3, and α4 are each set to, for example, 0.2 or greater and 1.0 or less, preferably 0.2 or greater and 0.6 or less.

[0125] Thus, according to the imaging unit 50, the outer edge of the region 7A overlaps with the wall portion 2b, and the adhesive 4 satisfies the above-mentioned conditions, thereby efficiently dissipating stress in the protective cover 3, reducing warping of the imaging element chip 1 caused by the bimetallic effect, and improving imaging quality.

[0126] In the above-described imaging unit 50, the circuit board 52 has the opening 52k, so the region 7A is frame-shaped. However, if the circuit board 52 is a flat plate without the opening 52k, the region 7A may also be rectangular in plan view.

[0127] As described above, the present specification discloses the following matters. (1)

[0129] An imaging element unit is fixed to a circuit board via a conductive member, the imaging element unit comprising:

[0130] a fixing component having a flat portion to which an imaging element chip is fixed, a wall portion surrounding a fixing surface of the imaging element chip in the flat portion, and a plurality of first terminals electrically connected to the imaging element chip, wherein the fixing component has a linear expansion coefficient smaller than a linear expansion coefficient of a circuit board to which the imaging element unit is fixed; and

[0131] a sealing member that seals the imaging element chip in a state of overlapping with the wall portion;

[0132] The sealing member and the wall portion are fixed to each other by an adhesive having a Young's modulus of 500 MPa or more. (2)

[0134] The imaging element unit according to (1), wherein

[0135] The adhesive is disposed with a width of 3 mm or more along a portion where the wall portion overlaps the sealing member when viewed from a direction perpendicular to the light receiving surface of the imaging element chip. (3)

[0137] The imaging element unit according to (2), wherein

[0138] The Young's modulus of the adhesive is less than 5000 MPa. (4)

[0140] The imaging element unit according to (2) or (3), wherein

[0141] The thickness of the adhesive is 60 μm or less. (5)

[0143] The imaging element unit according to (1), wherein

[0144] The Young's modulus of the adhesive is 5000 MPa or more. (6)

[0146] The imaging element unit according to (5), wherein

[0147] The adhesive is disposed with a width of 1 mm or more along a portion where the wall portion overlaps the sealing member when viewed from a direction perpendicular to the light-receiving surface of the imaging element chip. (7)

[0149] The imaging element unit according to (5) or (6), wherein

[0150] The thickness of the adhesive is 15 μm or less. (8)

[0152] An imaging element unit is fixed to a circuit board via a conductive member, the imaging element unit comprising:

[0153] a fixing component having a flat portion to which an imaging element chip is fixed, a wall portion surrounding a fixing surface of the imaging element chip in the flat portion, and a plurality of first terminals electrically connected to the imaging element chip, wherein the fixing component has a linear expansion coefficient smaller than a linear expansion coefficient of a circuit board to which the imaging element unit is fixed; and

[0154] a sealing member that seals the imaging element chip in a state of overlapping with the wall portion;

[0155] The sealing member and the wall portion are fixed to each other by an adhesive having a Young's modulus of less than 500 MPa and a thickness of 15 μm or less. (9)

[0157] The imaging element unit according to any one of (1) to (8), wherein

[0158] The conductive component is provided between the first terminal and the second terminal to fix the fixing component to the circuit board and to electrically connect the first terminal and the second terminal. The first terminal is exposed from a surface of the fixing component opposite to the fixing surface. The second terminal is formed on the circuit board arranged opposite to the surface of the fixing component opposite to the fixing surface.

[0159] When viewed from a direction perpendicular to the light-receiving surface of the imaging element chip, an outer edge portion of a region where the conductive member is disposed overlaps with the wall portion of the fixing member. (10)

[0161] The imaging element unit according to (9), wherein

[0162] A distance between a position of the wall portion overlapping the outer edge portion and an end portion of the wall portion on the imaging element chip side is not less than 20% and not more than 60% of a width of the wall portion in a direction parallel to the light receiving surface. (11)

[0164] The imaging element unit according to (9), wherein

[0165] The distance between a position of the wall portion overlapping the outer edge portion and an end portion of the wall portion on the imaging element chip side is 60% of a width of the wall portion in a direction parallel to the light receiving surface. (12)

[0167] The imaging element unit according to any one of (1) to (11), wherein

[0168] The flat portion and the wall portion are made of ceramics.

[0169] The sealing member is made of glass. (13)

[0171] A camera device comprising:

[0172] The imaging element unit according to any one of (1) to (12);

[0173] the aforementioned circuit board; and

[0174] A conductive component is arranged between the first terminal and the second terminal to fix the fixing component to the circuit board and electrically connect the first terminal to the second terminal. The first terminal is exposed from the surface of the fixing component on the side opposite to the fixing surface, and the second terminal is formed on the circuit board arranged opposite to the surface of the fixing component on the side opposite to the fixing surface.

[0175] Industrial applicability

[0176] The present invention is highly convenient and effective when applied to electronic devices having an imaging function, such as digital cameras, smartphones, tablet terminals, personal computers, robots, and endoscopes.

[0177] Explanation of symbols

[0178] 100-digital camera, 11-system control unit, 14-operation unit, 40-lens device, 41-camera lens, 42-aperture, 43-lens drive unit, 44-aperture drive unit, 45-lens control unit, 50-camera unit, 51-imaging element unit, 52-circuit board, 15-memory control unit, 16-main memory, 17-digital signal processing unit, 20-external memory control unit, 21-storage medium, 22-display control unit, 23-display unit, 1-imaging Component chip, 2-packaging body, 2a-flat portion, 2b-wall portion, 2c-recessed portion, 2d-fixing surface, 2e-back surface, 3-protective cover, 4-adhesive, 5-adhesive component, 7-conductive component, 7A-area, 10-light receiving surface, 52a-surface, 52k-opening, EX1, EX2, EY1, EY2-edge portion, EX3, EX4, EY3, EY4-end portion, L1, L2, L3, L4-distance, XD1, XD2, YD1, YD2-width.

Claims

1. An imaging element unit fixed to a circuit board via a conductive member, the imaging element unit comprising: a fixing component having a flat portion to which an imaging element chip is fixed, a wall portion surrounding a fixing surface of the imaging element chip in the flat portion, and a plurality of first terminals electrically connected to the imaging element chip, wherein a linear expansion coefficient of the fixing component is smaller than a linear expansion coefficient of a circuit board to which the imaging element unit is fixed; and a sealing member that seals the imaging element chip in a state overlapping with the wall portion when viewed from a direction perpendicular to the light receiving surface of the imaging element chip, The sealing member and the wall portion are fixed by an adhesive having a Young's modulus of 500 MPa or more and less than 5000 MPa. The adhesive has a thickness of 120 μm or less and is arranged with a width of 4 mm or more along a portion where the wall portion overlaps the sealing member when viewed from a direction perpendicular to the light-receiving surface of the imaging element chip.

2. An imaging element unit fixed to a circuit board via a conductive member, the imaging element unit comprising: a fixing component having a flat portion to which an imaging element chip is fixed, a wall portion surrounding a fixing surface of the imaging element chip in the flat portion, and a plurality of first terminals electrically connected to the imaging element chip, wherein a linear expansion coefficient of the fixing component is smaller than a linear expansion coefficient of a circuit board to which the imaging element unit is fixed; and a sealing member that seals the imaging element chip in a state overlapping with the wall portion when viewed from a direction perpendicular to the light receiving surface of the imaging element chip, The sealing member and the wall portion are fixed by an adhesive having a Young's modulus of 500 MPa or more and less than 5000 MPa. The adhesive has a thickness of 60 μm or less and is arranged with a width of 3 mm or more along a portion where the wall portion overlaps the sealing member when viewed from a direction perpendicular to the light-receiving surface of the imaging element chip.

3. An imaging element unit fixed to a circuit board via a conductive member, the imaging element unit comprising: a fixing component having a flat portion to which an imaging element chip is fixed, a wall portion surrounding a fixing surface of the imaging element chip in the flat portion, and a plurality of first terminals electrically connected to the imaging element chip, wherein a linear expansion coefficient of the fixing component is smaller than a linear expansion coefficient of a circuit board to which the imaging element unit is fixed; and a sealing member that seals the imaging element chip in a state overlapping with the wall portion when viewed from a direction perpendicular to the light receiving surface of the imaging element chip, The sealing member and the wall portion are fixed by an adhesive having a Young's modulus of 5000 MPa or more. The adhesive has a thickness of 15 μm or less and is arranged with a width of 1 mm or more along a portion where the wall portion overlaps the sealing member when viewed from a direction perpendicular to the light-receiving surface of the imaging element chip.

4. An imaging element unit fixed to a circuit board via a conductive member, the imaging element unit comprising: a fixing component having a flat portion to which an imaging element chip is fixed, a wall portion surrounding a fixing surface of the imaging element chip in the flat portion, and a plurality of first terminals electrically connected to the imaging element chip, wherein a linear expansion coefficient of the fixing component is smaller than a linear expansion coefficient of a circuit board to which the imaging element unit is fixed; and a sealing member that seals the imaging element chip in a state overlapping with the wall portion when viewed from a direction perpendicular to the light receiving surface of the imaging element chip, The sealing component and the wall portion are fixed by an adhesive having a Young's modulus of less than 500 MPa and a thickness of less than 15 μm, and the adhesive is arranged with a width of more than 4 mm along the portion where the wall portion overlaps with the sealing component when viewed from a direction perpendicular to the light-receiving surface of the imaging element chip. 5 . The imaging element unit according to claim 1 , wherein: The conductive component is provided between the first terminal and the second terminal, and fixes the fixing component to the circuit board and electrically connects the first terminal and the second terminal. The first terminal is exposed from the surface of the fixing component opposite to the fixing surface, and the second terminal is formed on the circuit board arranged to face the surface of the fixing component opposite to the fixing surface. When viewed from a direction perpendicular to the light-receiving surface of the imaging element chip, an outer edge portion of a region where the conductive member is disposed overlaps with the wall portion of the fixing member.

6. The imaging element unit according to claim 5, wherein A distance between a position of the wall portion overlapping the outer edge portion and an end portion of the wall portion on the imaging element chip side is not less than 20% and not more than 60% of a width of the wall portion in a direction parallel to the light receiving surface.

7. The imaging element unit according to claim 5, wherein The distance between a position of the wall portion overlapping the outer edge portion and an end portion of the wall portion on the imaging element chip side is 60% of a width of the wall portion in a direction parallel to the light receiving surface.

8. The imaging element unit according to any one of claims 1 to 4, wherein The flat portion and the wall portion are made of ceramics, The sealing component is glass.

9. A camera device comprising: The imaging element unit according to any one of claims 1 to 8; the circuit board; and A conductive component is arranged between the first terminal and the second terminal to fix the fixing component to the circuit board and electrically connect the first terminal and the second terminal. The first terminal is exposed from the surface of the fixing component opposite to the fixing surface, and the second terminal is formed on the circuit board arranged opposite to the surface of the fixing component opposite to the fixing surface.

Images