Camera unit, imaging module, and endoscope

Abstract

To provide a camera unit or the like capable of preventing cracks from occurring in an adhesive due to stress of a resin caused by a change in at least one of temperature and humidity.SOLUTION: The camera unit 20 includes an image sensor 22 including an optical device 21, a cover glass 24, a solid-state image sensing device 23, and a first adhesive 25 located between the cover glass 24 and the solid-state image sensing device 23 and bonding the cover glass 24 and the solid-state image sensing device 23, a second adhesive 26 bonding the optical device 21 and the cover glass 24, a first adhesive 28 covering at least a part of an 21s of a side surface of the optical device 21, and a second adhesive 29 covering a side surface of the first adhesive 26. The tensile elastic modulus of the second resin 29 is smaller than that of the first resin 28.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a camera unit configured by bonding an optical element and an image sensor, an imaging module including the camera unit, and an endoscope including the imaging module. [Background technology]

[0002] Conventionally, imaging modules including a camera unit have been used in endoscopes. The camera unit includes, for example, an optical element and an image sensor. The image sensor is configured by, for example, bonding a cover glass and a solid-state imaging element with an adhesive.

[0003] For example, Japanese Patent Application Laid-Open Publication No. 2012-189788 describes a camera module in which a camera module main body including a solid-state imaging device and WLO (Wafer Level Optics) is covered with a light-shielding resin and a first shield that blocks electromagnetic waves. The first shield is made of a metal tube with a bottom. The camera module main body is housed within the first shield with a gap. The light-shielding resin fills the gap between the camera module main body and the first shield. The publication further describes that the light-shielding resin is made of an upper layer resin (thermosetting resin) and a lower layer resin (ultraviolet-curing resin). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2012-189788 Summary of the Invention [Problem to be solved by the invention]

[0005] During the manufacturing process, when connecting the camera unit to the wiring board of the imaging module, solder bumps are reflowed at high temperatures in a reflow oven, for example. Furthermore, endoscopes equipped with imaging modules may be used at high temperatures, low temperatures, or high humidity. When the camera unit experiences changes in temperature or humidity, the resin covering the sides of the camera unit may deform, causing stress on the image sensor. This can lead to cracks in the adhesive layer between the cover glass and the solid-state imaging element, extending from the outer periphery of the image sensor to its interior, degrading image quality.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a camera unit, an imaging module, and an endoscope that can prevent cracks from occurring in the adhesive due to stress in the resin caused by changes in at least one of the temperature and humidity. [Means for solving the problem]

[0007] A camera unit according to one embodiment of the present invention comprises an image sensor having an optical element, a cover glass, a solid-state imaging element, and a first adhesive located between the cover glass and the solid-state imaging element and bonding the cover glass and the solid-state imaging element together, a second adhesive bonding the optical element and the cover glass together, a first resin covering at least a portion of the side surface of the optical element, and a second resin covering the side surface of the first adhesive, wherein the tensile modulus of elasticity of the second resin is smaller than the tensile modulus of elasticity of the first resin.

[0008] An imaging module according to one embodiment of the present invention comprises an image sensor comprising an optical element, a cover glass, a solid-state imaging element, and a first adhesive located between the cover glass and the solid-state imaging element and bonding the cover glass and the solid-state imaging element together; a second adhesive bonding the optical element and the cover glass together; a first resin covering at least a portion of a side surface of the optical element; and a second resin covering a side surface of the first adhesive, wherein the tensile modulus of the second resin is smaller than that of the first resin; a three-dimensional wiring board having a cavity formed by a side wall surrounding the camera unit with a distance between it and the side surface of the camera unit; and a bottom floor to which the camera unit is connected; and a third resin located between the side surface of the camera unit and the side wall.

[0009] An endoscope according to one aspect of the present invention comprises: an image sensor including an optical element, a cover glass, a solid-state imaging element, and a first adhesive located between the cover glass and the solid-state imaging element and bonding the cover glass and the solid-state imaging element together; a second adhesive that bonds the optical element and the cover glass together; a first resin that covers at least a portion of a side surface of the optical element; and a second resin that covers a side surface of the first adhesive, wherein the tensile modulus of the second resin is smaller than that of the first resin; a three-dimensional wiring board having a cavity formed by: a side wall that surrounds the camera unit with a distance between it and the side surface of the camera unit; and a bottom floor to which the camera unit is connected; an imaging module including: a camera unit having a cavity formed by: a side wall that surrounds the camera unit with a distance between it and the side surface of the camera unit; and a third resin located between the side surface of the camera unit and the side wall; and an insertion section to be inserted into a subject, wherein the imaging module is provided at the tip of the insertion section. [Effects of the Invention]

[0010] The camera unit, imaging module, and endoscope of the present invention can prevent cracks from occurring in the adhesive due to stress in the resin caused by changes in at least one of temperature and humidity. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view showing the appearance of an endoscope according to a first embodiment of the present invention. [Figure 2] 1 is a perspective view showing an overview of an imaging module according to a first embodiment. [Figure 3] 3 is a diagram showing an example of a cross section of the imaging module of the first embodiment taken along line III-III in FIG. 2. FIG. [Figure 4] 3 is a diagram showing another example of the cross section of the imaging module of the first embodiment taken along line III-III in FIG. 2. FIG. [Figure 5] 4 is a table showing an example of physical properties of a first resin, a second resin, a third resin, and a first adhesive in the first embodiment. [Figure 6] 4 is a flowchart showing a manufacturing process of the camera unit according to the first embodiment. [Figure 7] 4 is a diagram for explaining a manufacturing process of the camera unit according to the first embodiment. [Figure 8] FIG. 10 is a diagram showing an example of a cross section of an imaging module according to a modified example. [Figure 9] 10 is a cross-sectional view illustrating the boundary between the first resin and the second resin of the imaging module according to the modified example. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments described below.

[0013] In the drawings, the same or corresponding elements are appropriately designated by the same reference numerals. It should be noted that the drawings are schematic, and that the length relationships, length ratios, and quantities of elements within a single drawing may differ from reality in order to simplify the explanation. Furthermore, there may be parts in which the length relationships, ratios, quantities, etc. differ between multiple drawings. [First embodiment]

[0014] 1 to 7 show a first embodiment of the present invention. Fig. 1 is a perspective view showing the appearance of an endoscope 1 of the first embodiment.

[0015] The endoscope 1 includes an insertion section 2, an operation section 3, and a universal cable 4. The endoscope 1 is configured as, for example, a side-viewing electronic endoscope. However, the endoscope 1 may also be a direct-viewing type.

[0016] The insertion section 2 is configured to be inserted into a subject. The subject may be a living body such as a human or animal, or a non-living body such as a machine or building. The insertion section 2 includes, in order from the distal end to the proximal end, a distal end section 2a, a bending section 2b, and a flexible tube section 2c.

[0017] The distal end portion 2a is provided with an imaging module 10 (see FIG. 2, etc.), a lighting unit 6, a raising base 7, etc. Although an example in which the endoscope 1 includes the raising base 7 has been given here, the endoscope 1 does not necessarily need to include the raising base 7.

[0018] The bending portion 2b is a portion that can be bent in two directions or in four directions, ie, up, down, left, and right, for example.

[0019] The flexible tube section 2c is a tube section that has flexibility. Note that, here, an example is given in which the endoscope 1 is a flexible endoscope having the flexible tube section 2c. However, the endoscope 1 may be a rigid endoscope in which the portion corresponding to the flexible tube section 2c is rigid.

[0020] The operation unit 3 is disposed on the proximal end side of the insertion section 2. The operation unit 3 is a portion where the user operates the endoscope 1. The operation unit 3 includes a grip portion 3a, a bending operation knob 3b, a plurality of operation buttons 3c, a treatment tool insertion port 3d, and a treatment tool raising lever 3e.

[0021] The grip portion 3a is a portion where the user grips the endoscope 1 in the palm of his / her hand.

[0022] The treatment tool insertion port 3d is an opening on the proximal end side of the treatment tool channel. A treatment tool such as forceps is inserted into the treatment tool channel from the treatment tool insertion port 3d. The tip of the treatment tool is guided from the treatment tool channel to the elevator 7 and protrudes into the subject. Various treatments are performed on the subject using the protruding tip of the treatment tool.

[0023] The bending operation knob 3b is an operation device for operating the bending of the bending portion 2b. The bending operation knob 3b is operated, for example, with the thumb of the hand holding the grip portion 3a. When the bending operation knob 3b is operated, a bending operation wire (not shown) is pulled, and the bending portion 2b is bent.

[0024] When the bending portion 2b is bent, the direction of the tip portion 2a changes, which changes the imaging direction of the imaging module 10 and the irradiation direction of the illumination light from the illumination unit 6. The bending portion 2b is also bent to improve the insertability of the insertion portion 2 inside the subject.

[0025] The plurality of operation buttons 3c include, for example, an air / water supply button, a suction button, and buttons related to imaging.

[0026] The air and water supply button is a button for operating the air and water supply to the observation window provided on the distal end surface of the imaging module 10 at the distal end portion 2a. The observation window is cleaned by the liquid supply, and the cleaned liquid is blown away by the air supply. The air and water supply are performed via the air and water supply channels.

[0027] The suction button is a button for operating the suction from the distal end portion 2a to the inside of the subject. The suction from the inside of the subject is performed, for example, via the treatment tool channel that also serves as the suction channel. When the suction operation is performed, for example, liquid or mucous membrane is suctioned from the inside of the subject.

[0028] The buttons related to image capture are, for example, button switches such as a freeze button for temporarily stopping the monitor screen and a release button for capturing a still image.

[0029] The treatment tool raising lever 3e is a lever for operating the raising and lowering of the raising base 7 in the distal end portion 2a.

[0030] The universal cable 4 extends from, for example, the side surface of the base end of the operation unit 3. A connector 4a is provided at the extending end of the universal cable 4. The connector 4a connects the endoscope 1 to an endoscope processor (video processor), a light source device, a suction pump, a water tank, etc.

[0031] FIG. 2 is a perspective view showing an overview of the imaging module 10 of the first embodiment.

[0032] The imaging module 10 includes a three-dimensional wiring board 11 and a camera unit 20.

[0033] Three-dimensional wiring board 11 is configured as a three-dimensional (three-dimensional) molded circuit device (MID: Molded Interconnect Device). Three-dimensional wiring board 11 has a plurality of conductor patterns, electrodes, etc. three-dimensionally formed on the curved surface, uneven surface, through holes, etc. of an injection-molded three-dimensional substrate, for example.

[0034] Three-dimensional wiring board 11 includes assembly member 12 and protruding member 13 protruding from assembly member 12.

[0035] The protruding member 13 is, for example, a rectangular cylinder with a bottom and surrounded by a rectangular side wall. Inside the protruding member 13 is a cavity 13c in which the camera unit 20 is housed.

[0036] FIG. 3 is a diagram showing an example of a cross section of the imaging module 10 of the first embodiment taken along line III-III in FIG.

[0037] The camera unit 20 includes an optical element 21, an image sensor 22, a second adhesive 26, a first resin 28, and a second resin 29.

[0038] Although the specific configuration of the optical element 21 is not shown, it is, for example, a laminated lens including a plurality of optical lenses. The optical element 21 is, for example, configured as a WLO (Wafer Level Optics) manufactured on a wafer using a semiconductor manufacturing process. The optical element 21 forms an optical image of incident light.

[0039] Fig. 4 is a diagram showing another example of the cross section of the imaging module 10 of the first embodiment taken along line III-III in Fig. 2. As shown in Fig. 4, the optical element 21 includes, for example, an optical diaphragm 21a for cutting out unnecessary light. The optical diaphragm 21a may be configured as, for example, a light-blocking film (a specific example is a chromium film) with an opening in the center.

[0040] The image sensor 22 includes a cover glass 24 , a solid-state imaging element 23 , and a first adhesive 25 .

[0041] The solid-state imaging element 23 has an imaging surface on which a plurality of pixels are arranged, each pixel generating an electrical signal by photoelectrically converting incident light. The solid-state imaging element 23 converts the optical image of the subject formed by the optical element 21 into an imaging signal composed of an electrical signal for each pixel. Examples of the solid-state imaging element 23 include a CCD (Charge-coupled device) and a CMOS (Complementary Metal Oxide Semiconductor).

[0042] The solid-state imaging element 23 has a plurality of solder bumps 23a arranged on the surface opposite to the imaging surface, forming a ball grid array.

[0043] The first adhesive 25 is a transparent optical adhesive. The first adhesive 25 is located between the cover glass 24 and the solid-state imaging element 23. The first adhesive 25 contacts the cover glass 24 and the solid-state imaging element 23. The first adhesive 25 bonds the cover glass 24 to the imaging surface of the solid-state imaging element 23. The first adhesive 25 is provided in the entire area between the cover glass 24 and the imaging surface of the solid-state imaging element 23. The cover glass 24 and the solid-state imaging element 23 are bonded together by the first adhesive 25, thereby forming the image sensor 22.

[0044] The second adhesive 26 is a transparent optical adhesive. The second adhesive 26 bonds the optical element 21 and the cover glass 24 together. In this way, the optical element 21 is bonded to the image sensor 22.

[0045] The first resin 28 has light-blocking properties and covers at least a portion of the side surface 21s of the optical element 21. Note that a method of adding a black pigment such as carbon black to the resin may be used as a method of imparting light-blocking properties to the resin. However, the color of the first resin 28 is not limited to black as long as it has light-blocking properties. The first resin 28 may also be a resin that does not have light-blocking properties.

[0046] 3 and 4, the first resin 28 covers the entire periphery of the side surface 21s of the optical element 21, up to a point slightly above (on the incident light side of) the second adhesive 26. In the optical element 21, the surface bonded to the second adhesive 26 is the emission surface, and the surface opposite to the emission surface is the incidence surface.

[0047] In the example shown in FIG. 4, which illustrates the optical diaphragm 21a, the first resin 28 covers the entire periphery of the side surface 21s of the optical element 21 from the incident light side to the area between the optical diaphragm 21a and the second adhesive 26.

[0048] The second resin 29 covers the side surface 25s of the first adhesive 25. The second resin 29 further covers at least a part of the side surface 26s of the second adhesive 26. The second resin 29 contacts the side surface of the first adhesive 25.

[0049] In the example shown in Figures 3 and 4, the second resin 29 covers the entire circumference of the side surface 23s of the solid-state imaging element 23, the entire circumference of the side surface 25s of the first adhesive 25, the entire circumference of the side surface 24s of the cover glass 24, the entire circumference of the side surface 26s of the second adhesive 26, and the entire circumference of the lower end side (solid-state imaging element 23 side) of the side surface 21s of the optical element 21.

[0050] The first resin 28 and the second resin 29 are connected to each other on the side surface 21s of the optical element 21, and the entire periphery of the side surface 21s is covered with the first resin 28 and the second resin 29 without any gaps.

[0051] Camera unit 20 is disposed in cavity 13c of convex member 13 of three-dimensional wiring board 11.

[0052] Cavity 13c is a space defined by sidewall 13w and bottom floor 13b, and is surrounded by the inner surfaces of sidewall 13w and bottom floor 13b. Sidewall 13w surrounds camera unit 20 with a distance between it and side surface 20s of camera unit 20.

[0053] Camera unit 20 is connected by solder bumps 23a to electrodes (not shown) provided on the inner surface of bottom floor 13b of cavity 13c of three-dimensional wiring board 11. In other words, the inner surface of bottom floor 13b is the bottom surface of cavity 13c to which camera unit 20 is connected.

[0054] The solder bumps 23a are connected by, for example, reflow, which is a well-known process in which cream solder, a mixture of granular solder and flux, is heated in a reflow furnace to vaporize the flux and join the granular solder together for soldering.

[0055] The imaging module 10 includes a third resin 31 filled between the camera unit 20 and the cavity 13c. The third resin 31 has light-blocking properties. The third resin 31 is located between the side surface 20s of the camera unit 20 and the inner surface of the side wall 13w, and between the bottom surface 20b of the camera unit 20 and the inner surface of the bottom floor 13b. The third resin 31 may also be a resin that does not have light-blocking properties.

[0056] Fig. 5 is a diagram showing an example of the physical properties of the first resin 28, the second resin 29, the third resin 31, and the first adhesive 25 in the first embodiment. In the diagram of Fig. 5, the symbol "-" indicates that the value has not been obtained.

[0057] 5, the tensile modulus of elasticity of the first resin 28 is 6.4 (Gpa), and the tensile modulus of elasticity of the second resin 29 is 4.1 (Gpa). Therefore, the tensile modulus of elasticity of the second resin 29 is smaller than the tensile modulus of elasticity of the first resin 28.

[0058] 5, the third resin 31 has a tensile modulus of 6.4 (Gpa), which is the same as the tensile modulus of the first resin 28. The third resin 31 is made of, for example, the same material as the first resin 28. However, the third resin 31 may be made of a different material (a different resin) from the first resin 28, as long as the material has light-blocking properties.

[0059] For example, if the third resin 31 is made of a material having a tensile modulus equal to or greater than that of the first resin 28, the rigidity of the entire imaging module 10 can be increased.

[0060] Furthermore, if the third resin 31 is made of a material having a tensile modulus equal to or less than that of the second resin 29, the stress applied to the cover glass 24 from the third resin 31 when a change in at least one of the temperature and humidity occurs can be alleviated.

[0061] Generally, when a resin is at a temperature below the glass transition point Tg (or below the glass transition point Tg), the movement of the molecules is restricted and the resin becomes a hard glassy state, and when the temperature is above the glass transition point Tg (or above the glass transition point Tg), the molecules become more mobile and the resin becomes a soft rubbery state.

[0062] Therefore, the linear expansion coefficient of the resin at a temperature below the glass transition point Tg (or below the glass transition point Tg) is denoted as α1, and the linear expansion coefficient of the resin at a temperature above the glass transition point Tg (or higher than the glass transition point Tg) is denoted as α2.

[0063] The linear expansion coefficient α1 of the first resin 28 is 45 (ppm / °C), that of the second resin 29 is 67 (ppm / °C), that of the third resin 31 is 45 (ppm / °C), and that of the first adhesive 25 is 140 (ppm / °C).

[0064] The linear expansion coefficient α2 of the first resin 28 is 130 (ppm / ° C.), that of the second resin 29 is 170 (ppm / ° C.), and that of the third resin 31 is 130 (ppm / ° C.).

[0065] The glass transition temperatures Tg of the first resin 28 are 90° C., the second resin 29 is 3° C., the third resin 31 is 90° C., and the first adhesive 25 is 80° C.

[0066] First, consider the case where the temperature is less than (or equal to or less than) 3° C. In this temperature range, the linear expansion coefficients of first resin 28, second resin 29, third resin 31, and first adhesive 25 are all α1.

[0067] In this case, the difference (absolute value of the difference, the same applies below) between the linear expansion coefficient α1 of the second resin 29 (67 (ppm / °C)) and the linear expansion coefficient α1 of the first adhesive 25 (140 (ppm / °C)) is 73 (ppm / °C).

[0068] The difference between the linear expansion coefficient α1 of the first resin 28 (=45 (ppm / °C)) and the linear expansion coefficient α1 of the first adhesive 25 (=140 (ppm / °C)) is 95 (ppm / °C).

[0069] Therefore, at temperatures below (or equal to or lower than) 3°C, the difference of 73 (ppm / °C) between the linear expansion coefficient α1 of the second resin 29 and the linear expansion coefficient α1 of the first adhesive 25 is smaller than the difference of 95 (ppm / °C) between the linear expansion coefficient α1 of the first resin 28 and the linear expansion coefficient α1 of the first adhesive 25.

[0070] Next, consider the case where the temperature is equal to or higher than 3°C and lower than 80°C. In this temperature range, the linear expansion coefficients of the first resin 28, the third resin 31, and the first adhesive 25 are α1, and the linear expansion coefficient of the second resin 29 is α2.

[0071] At this time, the difference between the linear expansion coefficient α2 of the second resin 29 (=170 (ppm / °C)) and the linear expansion coefficient α1 of the first adhesive 25 (=140 (ppm / °C)) is 30 (ppm / °C).

[0072] The difference between the linear expansion coefficient α1 of the first resin 28 (=45 (ppm / °C)) and the linear expansion coefficient α1 of the first adhesive 25 (=140 (ppm / °C)) is 95 (ppm / °C).

[0073] Therefore, at temperatures above (or higher than) 3°C and below (or equal to) 80°C, the difference of 30 (ppm / °C) between the linear expansion coefficient α2 of the second resin 29 and the linear expansion coefficient α1 of the first adhesive 25 is smaller than the difference of 95 (ppm / °C) between the linear expansion coefficient α1 of the first resin 28 and the linear expansion coefficient α1 of the first adhesive 25.

[0074] Thus, at temperatures below (or equal to or lower than) 80°C, the difference between the linear expansion coefficient of the second resin 29 and the linear expansion coefficient of the first adhesive 25 is smaller than the difference between the linear expansion coefficient of the first resin 28 and the linear expansion coefficient of the first adhesive 25.

[0075] As an example of a material that satisfies the physical properties shown in FIG. 5, the first resin 28 and the third resin 31 may be epoxy resin, the second resin 29 may be acrylic resin, and the first adhesive 25 may be epoxy resin.

[0076] However, without being limited to this example, the first resin 28 and the third resin 31 may be made of an acrylic resin or a silicone resin. The second resin 29 may be made of an epoxy resin or a silicone resin. The first adhesive 25 may be made of an acrylic resin or a silicone resin.

[0077] Fig. 6 is a flowchart showing the manufacturing process (manufacturing method) of the camera unit 20 in the first embodiment. Fig. 7 is a diagram for explaining the manufacturing process of the camera unit 20 in the first embodiment.

[0078] The naked camera unit 20 manufactured by the semiconductor manufacturing process and not yet coated with the first resin 28 and the second resin 29 will be referred to as a wafer-level camera 20A. The wafer-level camera 20A includes an optical element 21, an image sensor 22, and a second adhesive 26.

[0079] 6 and 7 show the process of manufacturing the camera unit 20 using an already manufactured wafer-level camera 20A.

[0080] 6 begins, wafer-level cameras 20A are arranged at intervals on a support substrate 41 as shown in column A of FIG. 7 (step S1). The support substrate 41 is made of, for example, a glass substrate. The incident light side of the wafer-level camera 20A is temporarily adhered to the support substrate 41 (upside down from the state shown in FIG. 3).

[0081] A first resin 28 is supplied between the wafer-level cameras 20A arranged on the support substrate 41 (and outside the wafer-level cameras 20A arranged on both ends, and the same applies below) and filled up to the height described with reference to FIG. 3 (in FIG. 7, a height slightly below (on the incident light side) than the second adhesive 26) (step S2).

[0082] Furthermore, second resin 29 is supplied onto first resin 28 and filled up to the height described with reference to FIG. 3 (the height covering the entire periphery of side surface 23s of solid-state imaging element 23 of image sensor 22) (step S3).

[0083] When the processing of step S3 is completed, the entire periphery of the side surface of the wafer-level camera 20A is covered with the first resin 28 and the second resin 29, as shown in section B of Fig. 7. In the state shown in section B of Fig. 7, multiple wafer-level cameras 20A are integrated with the first resin 28 and the second resin 29.

[0084] In this state, the support substrate 41 is removed from the integrated wafer-level cameras 20A and replaced with a dicing tape 42 (step S4).

[0085] The wafer-level camera 20A is cut (diced) so that a predetermined thickness of the first resin 28 and the second resin 29 remains on the side surface of each wafer-level camera 20A (step S5). As a result, the diced camera units 20 are adhered to the dicing tape 42, as shown in column C of FIG.

[0086] Thereafter, each camera unit 20 is peeled off from the dicing tape 42 and picked up (step S6), and the process shown in FIG. 6 is completed.

[0087] As described above, the picked-up camera unit 20 is connected to the three-dimensional wiring board 11 by reflow soldering.

[0088] According to the first embodiment, the tensile modulus of elasticity of the second resin 29 covering the side surface 25s of the first adhesive 25 is set to be smaller than the tensile modulus of elasticity of the first resin 28. Therefore, the stress that the second resin 29 applies to the first adhesive 25 due to a change in at least one of the temperature and humidity can be made smaller than when the side surface 25s is covered with the first resin 28. This makes it possible to prevent cracks from occurring in the first adhesive 25 due to stress caused by a change in at least one of the temperature and humidity in the resin covering the side surface of the wafer-level camera 20A.

[0089] Specifically, during manufacturing when the camera unit 20 is connected to the three-dimensional wiring board 11 by high-temperature reflow, and during use when the endoscope 1 is placed in a high-temperature, low-temperature, or high-humidity environment, the stress applied to the first adhesive 25 can be reduced, and cracks can be prevented from occurring in the first adhesive 25.

[0090] Furthermore, the difference between the linear expansion coefficient of the second resin 29 and the linear expansion coefficient of the first adhesive 25 is set smaller than the difference between the linear expansion coefficient of the first resin 28 and the linear expansion coefficient of the first adhesive 25. As a result, the difference in the rate of change in length between the second resin 29 and the first adhesive 25 due to temperature change is smaller than the difference in the rate of change in length between the first resin 28 and the first adhesive 25. Therefore, by covering the side surface 25s of the first adhesive 25 with the second resin 29, it is possible to prevent cracks from occurring in the first adhesive 25.

[0091] Furthermore, the second resin 29 further covers at least a portion of the side surface 26s of the second adhesive 26. This reduces the stress applied to the second adhesive 26 during manufacturing and use, and prevents cracks from occurring in the second adhesive 26.

[0092] Since the side surface of the optical element 21 on the light incident side is covered with the first resin 28 having light blocking properties, it is possible to prevent unwanted light from being incident on the optical element 21.

[0093] According to the manufacturing method of the camera unit 20 described with reference to Figures 6 and 7, it is possible to manufacture a plurality of camera units 20 in a batch. Therefore, it is not necessary to perform a process of sealing each individual camera unit 20 with resin. This allows a plurality of camera units 20 to be manufactured using an automated and mechanized process, thereby reducing manufacturing costs.

[0094] As described above, in the camera unit of the first embodiment, the boundary BL between the first resin 28 and the second resin 29 is located on the side surface 21s of the optical element 21. In other words, the interface between the first resin 28 and the second resin 29 is located between the incident surface and the exit surface of the optical element 21.

[0095] That is, the camera unit: an optical element; an image sensor including a cover glass, a solid-state imaging element, and a first adhesive that bonds the cover glass and the solid-state imaging element; a second adhesive that bonds the optical element and the cover glass; a first resin having a light-blocking property that covers a part of a side surface of the optical element; a second resin that covers a side surface of the optical element that is not covered with the first resin, a side surface of the first adhesive, and a side surface of the solid-state imaging element, and does not cover the first resin; The second resin has a lower tensile modulus of elasticity than the first resin.

[0096] [Modification of the first embodiment] The camera unit, imaging module, and endoscope (camera unit, etc.) of the modified example are similar to the camera unit, etc. of the first embodiment and have the same effects. Therefore, in the following description, the same reference numerals are used to designate configurations with the same functions, and descriptions thereof will be omitted.

[0097] For example, as shown in FIG. 8, in the camera unit of this modified example, the boundary BL between the first resin 28 and the second resin 29 is located on the side surface of the cover glass 24 (D).

[0098] 9, the boundary BL between the first resin 28 and the second resin 29 may be located at any of (A) the interface between the optical element 21 and the second adhesive 26, (B) a side surface of the second adhesive 26, (C) the interface between the second adhesive 26 and the cover glass 24, (D) a side surface of the cover glass 24, or (E) the interface between the cover glass 24 and the first adhesive 25. In FIG. 9, (X) indicates the position of the boundary BL (side surface 21s of the optical element 21) in the camera unit of the first embodiment.

[0099] That is, the camera unit of this modified example is an optical element; an image sensor including a cover glass, a solid-state imaging element, and a first adhesive that bonds the cover glass and the solid-state imaging element; a second adhesive that bonds the optical element and the cover glass; a first resin having a light-blocking property that covers at least all side surfaces of the optical element; a second resin that covers a side surface of the solid-state imaging element from a side surface of the second adhesive that is not covered by the first resin and does not cover the first resin; an interface between the first resin and the second resin is located between a position of an interface between the optical element and the second adhesive and a position of an interface between the cover glass and the first adhesive, The second resin has a lower tensile modulus of elasticity than the first resin.

[0100] It should be noted that the present invention is not limited to the above-described embodiments. In the implementation stage, the components can be modified and embodied without departing from the spirit of the invention. Furthermore, various aspects of the invention can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be deleted from all the components disclosed in the embodiments. Furthermore, components from different embodiments may be appropriately combined. In this way, it goes without saying that various modifications and applications are possible within the scope of the gist of the invention. [Explanation of symbols]

[0101] 1. Endoscope 2...Insertion section 2a...Tip 2b...Bend 2c...Flexible tube section 3...Operation unit 3a...Gripping part 3b...Bending control knob 3c...Operation buttons 3d...Treatment tool insertion port 3e...Treatment tool lift lever 4...Universal cable 4a...Connector 6...Lighting unit 7...Elevating platform 10...Image capture module 11...Three-dimensional wiring board 12...Assembly parts 13...Convex member 13b...Substrate 13c...cavity 13w…side wall 20...Camera unit 20A...Wafer-level camera 20b...Bottom of camera unit 20s...Side of camera unit 21...Optical element 21a...Optical aperture 21s...Side of the optical element 22...Image sensor 23...Solid-state image sensor 23a...Solder bump 23s...Side of the solid-state image sensor 24...Cover glass 24s...side of cover glass 25...First adhesive 25s...first adhesive side 26...Cover glass 26s...Second adhesive side 28...First resin 29...Second resin 31...Third resin 41...Support board 42...Dicing tape

Claims

1. an optical element; an image sensor including a cover glass, a solid-state imaging element, and a first adhesive positioned between the cover glass and the solid-state imaging element and bonding the cover glass and the solid-state imaging element; a second adhesive that bonds the optical element and the cover glass; a first resin covering at least a portion of a side surface of the optical element; a second resin covering a side surface of the first adhesive; A camera unit, wherein the second resin has a lower tensile modulus of elasticity than the first resin.

2. 2. The camera unit according to claim 1, wherein the first adhesive is in contact with the cover glass and the solid-state image sensor.

3. 3. The camera unit according to claim 2, wherein the first adhesive is provided over the entire area between the cover glass and the imaging surface of the solid-state imaging device.

4. 2. The camera unit according to claim 1, wherein the second resin is in contact with a side surface of the first adhesive.

5. the first resin has a light-blocking property, the second resin is not covered by the first resin, covers a side surface of the solid-state imaging element from a side surface of the second adhesive, and does not cover the first resin; The interface between the first resin and the second resin is located between a position between the incident surface and the exit surface of the optical element and a position of the interface between the cover glass and the first adhesive.

2. The camera unit according to claim 1.

6. 2. The camera unit according to claim 1, wherein the difference between the linear expansion coefficient of the second resin and the linear expansion coefficient of the first adhesive is smaller than the difference between the linear expansion coefficient of the first resin and the linear expansion coefficient of the first adhesive.

7. an optical element; an image sensor including a cover glass, a solid-state imaging element, and a first adhesive positioned between the cover glass and the solid-state imaging element and bonding the cover glass and the solid-state imaging element; a second adhesive that bonds the optical element and the cover glass; a first resin covering at least a portion of a side surface of the optical element; a second resin covering a side surface of the first adhesive; a camera unit in which the second resin has a lower tensile modulus of elasticity than the first resin; a three-dimensional wiring board having a cavity formed by a side wall surrounding the camera unit with a distance between the side wall and the camera unit, and a bottom floor to which the camera unit is connected; a third resin positioned between a side surface of the camera unit and the side wall.

8. 8. The imaging module according to claim 7, wherein the first adhesive is in contact with the cover glass and the solid-state imaging element.

9. 9. The imaging module according to claim 8, wherein the first adhesive is provided over the entire area between the cover glass and the imaging surface of the solid-state imaging element.

10. The imaging module according to claim 7 , wherein the second resin is in contact with a side surface of the first adhesive.

11. the first resin has a light-blocking property, the second resin is not covered by the first resin, covers a side surface of the solid-state imaging element from a side surface of the second adhesive, and does not cover the first resin; 8. The imaging module according to claim 7, wherein the interface between the first resin and the second resin is located between a position between the incident surface and the exit surface of the optical element and a position of the interface between the cover glass and the first adhesive.

12. 8. The imaging module according to claim 7, wherein a difference between the linear expansion coefficient of the second resin and the linear expansion coefficient of the first adhesive is smaller than a difference between the linear expansion coefficient of the first resin and the linear expansion coefficient of the first adhesive.

13. 8. The imaging module according to claim 7, wherein the third resin has a tensile modulus of elasticity equal to that of the first resin.

14. an optical element; an image sensor including a cover glass, a solid-state imaging element, and a first adhesive positioned between the cover glass and the solid-state imaging element and bonding the cover glass and the solid-state imaging element; a second adhesive that bonds the optical element and the cover glass; a first resin covering at least a portion of a side surface of the optical element; a second resin covering a side surface of the first adhesive; a camera unit in which the second resin has a lower tensile modulus of elasticity than the first resin; a three-dimensional wiring board having a cavity formed by a side wall surrounding the camera unit with a distance between the side wall and the camera unit, and a bottom floor to which the camera unit is connected; an imaging module including a third resin positioned between a side surface of the camera unit and the side wall; an insertion section to be inserted into a subject; and the imaging module is provided at a tip of the insertion section.

15. 15. The endoscope according to claim 14, wherein the first adhesive contacts the cover glass and the solid-state image sensor.

16. 16. The endoscope according to claim 15, wherein the first adhesive is provided over the entire area between the cover glass and the imaging surface of the solid-state imaging device.

17. The endoscope according to claim 14, wherein the second resin is in contact with a side surface of the first adhesive.

18. the first resin has a light-blocking property, the second resin is not covered by the first resin, covers a side surface of the solid-state imaging element from a side surface of the second adhesive, and does not cover the first resin; 15. The endoscope according to claim 14, wherein the interface between the first resin and the second resin is located between a position between the incident surface and the exit surface of the optical element and a position of the interface between the cover glass and the first adhesive.

19. 15. The endoscope according to claim 14, wherein a difference between the linear expansion coefficient of the second resin and the linear expansion coefficient of the first adhesive is smaller than a difference between the linear expansion coefficient of the first resin and the linear expansion coefficient of the first adhesive.

20. 15. The endoscope according to claim 14, wherein the third resin has a tensile modulus of elasticity equal to that of the first resin.

Images