Imaging unit, endoscope, and method for manufacturing imaging unit

Abstract

To provide an imaging unit capable of suppressing occurrence of flare by reducing surface scattered light.SOLUTION: An imaging unit 1 includes: a three-dimensional wiring board 10 including a recessed portion having a side surface and a bottom surface; a camera module 30 disposed in the recessed portion; and a light-shielding resin 20 filled in a gap formed between the side surface and the bottom surface, and the camera module 30; wherein the resin 20 has a transmissivity of 0.5% or less and a light reflectivity of 5% or less with respect to light having wavelengths from 380 to 780nm, and when a polar angle in an incident direction is θi, an azimuth angle from an incident surface is Φr, and a value of a bi-directional reflectivity distribution function in a direction of the polar angle θr is BRDF (θi, Φr, θr), the value of the bi-directional reflectivity distribution function is 0.1 or less of incident light in a case where θi is 45 to 75 degrees, Φr is - 60 to 60 degrees, and θr is -85 to 85 degrees, where Φr≠0 and θi≠θr.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an imaging unit containing a light-shielding resin, an endoscope, and a method for manufacturing the imaging unit.

Background Art

[0002] Conventionally, an imaging unit is disposed at the tip of an endoscope. The imaging unit includes a camera unit in a recess provided in a three-dimensional wiring board. A light-shielding resin is filled between the recess and the camera unit for the purpose of improving bonding strength, water tightness, and light-shielding properties.

[0003] For example, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2012-189788) discloses a camera module in which a light-shielding resin formed in black by adding a black pigment of carbon black is filled in a gap between a camera module body and a shield.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, even when a light-shielding resin is filled in the gap between the camera module body and the shield, it has been impossible to reduce surface scattered light, and flare may occur.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide an imaging unit, an endoscope, and a method for manufacturing the imaging unit that can reduce surface scattered light and suppress the occurrence of flare.

Means for Solving the Problems

[0007] The imaging unit according to one aspect of the present invention includes a three-dimensional wiring board having a recess with a side surface and a bottom surface, a camera module disposed in the recess, a light-shielding resin filled in a gap formed between the side surface and the bottom surface and the camera module, wherein the resin has a transmittance of 0.5% or less and a light reflectance of 5% or less for light with a wavelength of 380 to 780 nm. When the value of the bidirectional reflectance distribution function in the direction with an azimuth angle Φr from the incident surface and a polar angle θr when the polar angle of the incident direction is θi is defined as BRDF(θi, Φr, θr), the value of the bidirectional reflectance distribution function is 0.1 or less of the incident light when θi is 45 to 75 degrees, Φr is -60 to 60 degrees, and θr is -85 to 85 degrees. (However, Φr ≠ 0 and θi ≠ θr)

[0008] Also, an endoscope according to one aspect of the present invention has an imaging unit at the tip of an insertion portion inserted into a subject. The imaging unit includes a three-dimensional wiring board having a recess with a side surface and a bottom surface, a camera module disposed in the recess, a light-shielding resin filled in a gap formed between the side surface and the bottom surface and the camera module, wherein the resin has a transmittance of 0.5% or less and a light reflectance of 5% or less for light with a wavelength of 380 to 780 nm. When the value of the bidirectional reflectance distribution function in the direction with an azimuth angle Φr from the incident surface and a polar angle θr when the polar angle of the incident direction is θi is defined as BRDF(θi, Φr, θr), the value of the bidirectional reflectance distribution function is 0.1 or less of the incident light when θi is 45 to 75 degrees, Φr is -60 to 60 degrees, and θr is -85 to 85 degrees. (However, Φr ≠ 0 and θi ≠ θr)

[0009] Also, a method for manufacturing an imaging unit according to an aspect of the present invention includes a step of housing a camera module in a recess of a three-dimensional wiring board and connecting the wiring of the three-dimensional wiring board and the camera module with an external electrode, and filling a gap between the recess of the three-dimensional wiring board and the camera module with a first resin from the bottom surface of the recess to the position of the aperture of the camera module, and filling a gap between the recess of the three-dimensional wiring board and the camera module with a second resin from the aperture to the outermost surface of the laminated lens of the camera module. The first resin has a higher dielectric breakdown resistance value and a lower viscosity than the second resin.

Advantages of the Invention

[0010] According to the imaging unit, endoscope, and method for manufacturing an imaging unit of the present invention, surface scattered light can be reduced and the occurrence of flare can be suppressed.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0012] Hereinafter, embodiments will be described in detail with reference to the drawings. Note that the drawings based on the embodiments are schematic, and the relationships between the thickness and width of each part, the ratio of the thickness of each part, and the relative angles are different from the actual ones. There are also parts where the dimensional relationships and ratios are different between the drawings. The direction in which light enters is referred to as "up".

[0013] (First Embodiment) FIG. 1 is an overall configuration diagram showing an example of the overall configuration of an endoscope according to the first embodiment. As shown in FIG. 1, the endoscope 100 includes an insertion portion 101, an operation portion 102, a universal cord 103, and an endoscope connector 104.

[0014] The insertion portion 101 having an elongated tube shape is inserted into the body cavity of a living body. The insertion portion 101 is successively provided with a distal end portion 101A, a bending portion 101B, and a flexible tube 101C from the distal end side, and is flexible as a whole.

[0015] The distal end portion 101A includes an imaging unit 1 for acquiring image information of a subject inside. In addition to the imaging unit 1, the distal end portion 101A also includes a treatment instrument insertion channel, an illumination unit, and the like inside.

[0016] The bending portion 101B bends in the vertical and horizontal directions in response to the rotation operation of the bending knob of the operation portion 102 for performing a bending operation.

[0017] The flexible tube 101C is a tubular member having flexibility that can be flexibly moved passively. Inside the flexible tube 101C, a treatment instrument insertion channel, various electric signal lines, a light guide fiber bundle, and the like are inserted. The electric signal lines extend from the imaging unit 1 built in the distal end portion 101A, pass through the operation portion 102, and extend to the universal cord 103. The light guide fiber bundle guides the light from a light source device, which is an external device, to the distal end surface of the distal end portion 101A.

[0018] The operation portion 102 is connected to the proximal end portion of the insertion portion 101 and has a plurality of operation members and the like. The operation portion 102 is provided with a bending knob for bending the bending portion 101B rotatably, and a suction button, an air supply / water supply button, switches for various endoscope functions, and the like.

[0019] The universal code 103 is a flexible tubular member extending from the operation unit 102. The endoscope connector 104 is a connecting member for connecting the universal code 103 and external devices such as a video processor and a light source device.

[0020] The endoscope may be a flexible endoscope with a flexible insertion portion or a rigid endoscope with a rigid insertion portion. Also, the application of the endoscope may be for medical use or industrial use.

[0021] Next, the configuration of the imaging unit 1 provided inside the distal end portion 101A will be described. FIG. 2 is a perspective view showing the configuration of the imaging unit of the first embodiment. FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2.

[0022] As shown in FIGS. 2 and 3, the imaging unit 1 includes a three-dimensional wiring board 10, a resin 20, and a camera module 30.

[0023] The three-dimensional wiring board 10 is a wiring board that is not flat, for example, a molded interconnect device (MID), and has a bottomed recess (cavity) H10 with an opening on the upper surface 10SA. The camera module 30 is housed in the recess H10.

[0024] The base material of the three-dimensional wiring board 10 is a non-conductive resin, particularly an engineering plastic that can be injection-molded. The base material is made of, for example, PA (polyamide), PC (polycarbonate), LCP (liquid crystal polymer), PEEK (polyetheretherketone), nylon, PPA (polyphthalamide), ABS (acrylonitrile / butadiene / styrene), or a composite resin in which an inorganic filler is blended with these resins.

[0025] The resin 20 is filled in the gap formed between the concave portion H10 and the camera module 30. More specifically, the resin 20 is filled in the gap formed between the side surface and the bottom surface of the concave portion H10 and the camera module 30. The resin 20 is, for example, an epoxy resin added with a black carbon slurry and has light-shielding properties. Note that the black material added to the resin 20 is not limited to the carbon slurry and may be carbon powder.

[0026] Preferably, the resin 20 is filled in the range of 95% to 100% of the total length D1 of the imaging unit 1 from the bottom surface of the concave portion H10.

[0027] The camera module 30 includes a laminated lens 31 having a plurality of lenses 33 and 34 and a diaphragm 35, and an image sensor 32. In the cross-sectional view, the plurality of lenses 33 and 34 are illustrated as flat plates. In addition, the configuration of the optical system, that is, the configuration (thickness, shape), type, number, and stacking order of the plurality of lenses 33 and 34 and the diaphragm 35 can be variously modified according to the specifications.

[0028] Preferably, the distance D2 from the outermost surface (front surface) of the laminated lens 31 to the diaphragm 35 in the direction along the optical axis O of the imaging unit 1 is 30% to 60% of the total length D1 of the imaging unit 1. Also, preferably, the aperture diameter W1 of the diaphragm 35 is 6% to 9% of the maximum dimension W2 of the laminated lens 31 in the direction perpendicular to the optical axis O of the imaging unit 1.

[0029] The image sensor 32 has a light-receiving portion made of a CCD or the like. The image sensor 32 is connected to the wiring 19 of the three-dimensional wiring board 10 via an external electrode 36 such as a solder ball. The image sensor 32 receives a drive signal from the outside and transmits an imaging signal to the outside via the external electrode 36 and the wiring 19.

[0030] Note that a semiconductor element for processing an imaging signal may be laminated on the lower surface of the image sensor 32 in the camera module 30, or a cover glass may be disposed on the upper surface of the image sensor 32.

[0031] The resin 20 of this embodiment contains 0.2 g to 0.4 g of carbon slurry per 100 g of epoxy resin, and thus has the following optical properties. As a result, the resin 20 can reduce surface scattered light and suppress flare.

[0032] Figure 4 is a diagram for explaining the relationship between incident light and reflected light. As shown in Figure 4, let the polar angle of the light (incident light) emitted from the light source 41 to the surface S1 of an object be θi. Also, let the azimuth angle from the incident plane S2 of the light (reflected light) reflected by the surface S1 be Φr. Further, let the polar angle of the light (reflected light) reflected by the surface S1 be θr.

[0033] The resin 20 contains 0.2 to 0.4 g of carbon slurry per 100 g of epoxy resin, and thus has the properties that the transmittance of light (visible light) with a wavelength of 380 to 780 nm is 0.5% or less and the reflectance is 5% or less.

[0034] Furthermore, when θi is 45 to 75 degrees, Φr is -60 to 60 degrees, and θr is -85 to 85 degrees, the resin 20 has the property that the value of the bidirectional reflectance distribution function (BRDF) of the reflected light detected by the detector 42 is 0.1 or less of the incident light. However, Φr ≠ 0 and θi ≠ θr.

[0035] The reason for setting the polar angle θi of the incident direction to 45 to 75 degrees is that light outside the range does not affect flare. For example, when the polar angle θi of the incident direction is 75 degrees or more, multiple reflections are required and it will not be detected as flare. Also, the reason for setting the azimuth angle Φr from the incident plane to -60 to 60 degrees is that light outside the range is blocked by the aperture 35. Further, the reason for setting the polar angle θr from the incident plane to -85 to 85 degrees is that light outside the range does not affect flare. Also, the reason for setting Φr ≠ 0 and θi ≠ θr is to exclude specular reflection.

[0036] The imaging unit 1 of this embodiment fills the resin 20 having the above optical characteristics between the three-dimensional wiring board 10 and the camera module 30. Thereby, the imaging unit 1 of this embodiment can reduce surface scattered light and suppress flare as compared with the case where only a light-shielding resin is filled.

[0037] (Second Embodiment) Next, the second embodiment will be described. FIG. 5 is a cross-sectional view showing the configuration of the imaging unit of the second embodiment. In FIG. 5, the same components as those in FIG. 3 are denoted by the same reference numerals and the description thereof is omitted.

[0038] As shown in FIG. 5, the imaging unit 1A is filled with a first resin 20A and a second resin 20B in a gap formed between the concave portion H10 of the three-dimensional wiring board 10 and the camera module 30.

[0039] The first resin 20A is filled from the bottom surface of the concave portion H10 to the aperture 35 or the lower surface side of the aperture 35. The first resin 20A is a resin having a higher dielectric breakdown resistance value and a lower viscosity than the second resin 20B.

[0040] The second resin 20B has a dielectric breakdown voltage of less than 15 kV per 100 μm. On the other hand, the first resin 20A has a dielectric breakdown voltage of 15 kV or more per 100 μm. In this way, by increasing the dielectric breakdown resistance value of the first resin 20A filled in the gaps between the plurality of external electrodes 36, the electrostatic resistance can be improved.

[0041] In addition, the first resin 20A has a lower viscosity than the second resin 20B, so that it is easier to fill the gaps between the plurality of external electrodes 36 disposed between the concave portion H10 and the bottom surface of the camera unit 30.

[0042] The second resin 20B is the same resin as the resin 20 of the first embodiment, that is, it contains 0.2 to 0.4 g of carbon slurry per 100 g of epoxy resin. The second resin 20B is filled from the aperture 35 or the lower surface side of the aperture 35 to the outermost surface of the laminated lens 31, more specifically, in the range of 95% to 100% of the total length D1 of the imaging unit 1. Since the second resin 20B is the same resin as the resin 20 of the first embodiment, it can reduce surface scattered light and suppress flare.

[0043] The imaging unit 1A of this embodiment houses the camera module 30 in the recess H10 of the three-dimensional wiring board 10, and connects the wiring 19 of the three-dimensional wiring board 10 and the camera module 30 by the external electrode 36.

[0044] Thereafter, the first resin 20A is filled in the gap between the recess H10 of the three-dimensional wiring board 10 and the camera module 30 from the bottom surface of the recess H10 to the position of the aperture 35 (or the lower surface side of the aperture 35).

[0045] Finally, the imaging unit 1A can be assembled by filling the second resin 20B in the gap between the recess H10 of the three-dimensional wiring board 10 and the camera module 30 from the aperture 35 (or the lower surface side of the aperture 35) to the outermost surface of the laminated lens 31.

[0046] The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the gist of the present invention.

Explanation of Reference Numerals

[0047] 1, 1A... Imaging unit, 10... Three-dimensional wiring board, 20... Resin, 20A... First resin, 20B... Second resin, 30... Camera module, 31... Laminated lens, 32... Image sensor, 33, 34... Lenses, 35... Aperture, 36... External electrode, 41... Light source, 42... Detector, 100... Endoscope, 101... Insertion portion, 101A... Tip portion, 101B... Curved portion, 101C... Flexible tube, 102... Operation portion, 103... Universal cord, 104... Endoscope connector.

Claims

1. A three-dimensional wiring board having a recess having a side surface and a bottom surface; A camera module disposed in the recess; a light-shielding resin filled in gaps formed between the side and bottom surfaces and the camera module; Equipped with The resin has a wavelength of 380 to 780 nm. The transmittance is 0.5% or less, The light reflectance is 5% or less, When the polar angle of the incident direction is θi, the azimuth angle from the incident surface is Φr, and the value of the bidirectional reflectance distribution function in the direction of the polar angle θr is BRDF(θi, Φr, θr), The value of the bidirectional reflectance distribution function is θi is 45 to 75 degrees Φr is -60 to 60 degrees θr is -85 to 85 degrees is equal to or less than 0.1 of the incident light when (where Φr≠0 and θi≠θr).

2. the camera module includes a laminated lens having a plurality of lenses and an aperture, and an image sensor; 2. The imaging unit according to claim 1, wherein a distance from an outermost surface of the laminated lens to the aperture in a direction along an optical axis of the camera module is 0.3 to 0.7 of a total length of the camera module.

3. 3. The imaging unit according to claim 2, wherein the aperture diameter of the diaphragm is 0.06 to 0.09 of the maximum dimension of the laminated lens in a direction perpendicular to the optical axis of the camera module.

4. 2. The image pickup unit according to claim 1, wherein the resin is an epoxy resin to which a black carbon slurry is added.

5. the resin includes a first resin filled on a bottom side of the recess and a second resin filled on an opening side of the recess, the first resin is filled from a bottom surface of the recess to a position where the restriction is provided, and has a higher dielectric breakdown resistance value than the second resin; 3. The imaging unit according to claim 2, wherein the second resin is filled from the diaphragm to a position of the outermost surface of the laminated lens.

6. The imaging unit is provided at the tip of an insertion part that is inserted into a subject. The imaging unit includes: A three-dimensional wiring board having a recess having a side surface and a bottom surface; A camera module disposed in the recess; a light-shielding resin filled in gaps formed between the side and bottom surfaces and the camera module; Equipped with The resin has a wavelength of 380 to 780 nm. The transmittance is 0.5% or less, The light reflectance is 5% or less, When the polar angle of the incident direction is θi, the azimuth angle from the incident surface is Φr, and the value of the bidirectional reflectance distribution function in the direction of the polar angle θr is BRDF(θi, Φr, θr), The value of the bidirectional reflectance distribution function is θi is 45 to 75 degrees Φr is -60 to 60 degrees θr is -85 to 85 degrees is 0.1 or less of the incident light when (where Φr≠0 and θi≠θr).

7. the camera module includes a laminated lens having a plurality of lenses and an aperture, and an image sensor; The endoscope according to claim 6, characterized in that the distance from the outermost surface of the laminated lens to the aperture in a direction along the optical axis of the camera module is 0.3 to 0.7 of the total length of the camera module.

8. 8. The endoscope according to claim 7, wherein the aperture diameter of the diaphragm is 0.06 to 0.09 of the maximum dimension of the laminated lens in a direction perpendicular to the optical axis of the camera module.

9. 7. The endoscope according to claim 6, wherein the resin is an epoxy resin to which a black carbon slurry is added.

10. the resin includes a first resin filled on a bottom side of the recess and a second resin filled on an opening side of the recess, the first resin is filled from a bottom surface of the recess to a position where the restriction is provided, and has a higher dielectric breakdown resistance value than the second resin; 8. The endoscope according to claim 7, wherein the second resin is filled from the aperture to a position of the outermost surface of the laminated lens.

11. a step of accommodating a camera module in a recess of the three-dimensional wiring board and connecting the wiring of the three-dimensional wiring board and the camera module by an external electrode; filling a gap between the recess of the three-dimensional wiring board and the camera module with a first resin from a bottom surface of the recess to a position of an aperture of the camera module; filling a gap between the recess of the three-dimensional wiring board and the camera module with a second resin from the diaphragm to an outermost surface of the laminated lens of the camera module; having A method for manufacturing an imaging unit, wherein the first resin has a higher dielectric breakdown resistance and a lower viscosity than the second resin.

Images