阅读说明：本技术 内窥镜用摄像装置的制造方法、内窥镜用摄像装置及内窥镜 (Method for manufacturing endoscope image pickup device, and endoscope ) 是由 前江田和也 于 2019-05-14 设计创作，主要内容包括：内窥镜用摄像装置(1)的制造方法具备如下工序：晶片制作工序(S10),制作第1光学晶片(10W)和具有间隔件(25)的第2光学晶片(20W)；第1树脂配设工序(S20),配设壁(60),该壁(60)由第1树脂构成,高度比间隔件(25)高,且无间隙地包围光路；密封工序(S30),将壁(60)夹在第1光学晶片(10W)和第2光学晶片(20W)之间来压接第1光学晶片(10W)和第2光学晶片(20W)；第2树脂配设工序(S40),在壁(60)的周围填充第2树脂(70)；固化工序(S50),对第2树脂(70)进行固化处理,由此所述第2树脂(70)收缩,第1光学晶片(10W)和第2光学晶片(20W)被固定为通过间隔件(25)规定了间隔的状态；单片化工序(S60),将接合晶片(5W)切断来制作光学部(5)；以及摄像部配设工序(S70),在光学部(5)配设摄像部(50)。(The method for manufacturing the endoscope imaging device (1) comprises the following steps: a wafer production step (S10) for producing a 1 st optical wafer (10W) and a 2 nd optical wafer (20W) having a spacer (25); a 1 st resin arrangement step (S20) of arranging a wall (60), wherein the wall (60) is made of the 1 st resin, has a height higher than that of the spacer (25), and surrounds the optical path without a gap; a sealing step (S30) for pressing and connecting the 1 st optical wafer (10W) and the 2 nd optical wafer (20W) by sandwiching the wall (60) between the 1 st optical wafer (10W) and the 2 nd optical wafer (20W); a 2 nd resin arrangement step (S40) for filling the periphery of the wall (60) with a 2 nd resin (70); a curing step (S50) in which the 2 nd resin (70) is shrunk by curing the 2 nd resin (70), and the 1 st optical wafer (10W) and the 2 nd optical wafer (20W) are fixed at a predetermined interval by a spacer (25); a singulation step (S60) for cutting the bonded wafer (5W) to produce an optical portion (5); and an image pickup unit arranging step (S70) for arranging the image pickup unit (50) on the optical unit (5).)

1. A method of manufacturing an imaging device for an endoscope,

the method for manufacturing the endoscope imaging device comprises the following steps:

a wafer production step of producing a 1 st optical wafer and a 2 nd optical wafer, the 1 st optical wafer having a 1 st main surface and a 2 nd main surface opposed to the 1 st main surface and including a plurality of 1 st optical elements, the 2 nd optical wafer including a plurality of 2 nd optical elements, the plurality of 2 nd optical elements having a 3 rd main surface and a 4 th main surface opposed to the 3 rd main surface, and each of the 3 rd main surfaces having a spacer;

a 1 st resin disposing step of disposing a plurality of walls made of the 1 st resin, having a height higher than that of the spacers, on the 2 nd main surface or the 3 rd main surface so as to surround the respective optical paths without a gap;

a sealing step of sealing the optical path by sandwiching the wall between the 2 nd main surface and the 3 rd main surface and pressing the 2 nd main surface and the 3 rd main surface;

a 2 nd resin disposing step of filling an uncured and liquid 2 nd resin between the 2 nd main surface and the 3 rd main surface around the wall;

a curing step of curing the 2 nd resin, thereby shrinking the 2 nd resin and fixing the 2 nd main surface and the 3 rd main surface in a state where a space is defined by the spacer;

a singulation step of cutting a bonded wafer in which the 1 st optical wafer and the 2 nd optical wafer are fixed by the 2 nd resin to produce an optical portion; and

and an image pickup unit disposing step of disposing an image pickup unit for receiving the subject image condensed by the optical unit on the optical unit.

2. The method of manufacturing an endoscopic imaging device according to claim 1,

the height of the wall when the spacer is disposed in the 1 st resin disposing step is 101% to 110% of the height of the spacer.

3. The method of manufacturing an endoscopic imaging device according to claim 2,

the plurality of walls are made using a film composed of the 1 st resin.

4. The method of manufacturing an endoscopic imaging device according to claim 3,

the wafer fabrication process is a mold forming process.

5. An imaging device for an endoscope, characterized in that,

the endoscope image pickup device comprises an optical unit and an image pickup unit for receiving an object image condensed by the optical unit,

the optical portion has:

a 1 st optical member having a 1 st main surface and a 2 nd main surface opposed to the 1 st main surface;

a 2 nd optical member having a 3 rd main surface and a 4 th main surface opposed to the 3 rd main surface, the 3 rd main surface being opposed to the 2 nd main surface, the 3 rd main surface around the optical path having a spacer that defines a distance between the 2 nd main surface and the 3 rd main surface;

a 1 st resin which constitutes a wall that seals the optical path between the 2 nd main surface and the 3 rd main surface, has the same height as the spacer, and surrounds the optical path without a gap; and

a 2 nd resin filled around the wall at the same height as the spacer,

the 1 st resin has a hardness smaller than that of the 2 nd resin.

6. The endoscopic imaging device according to claim 5,

the 2 nd resin is a curable resin.

7. The endoscopic imaging device according to claim 6,

the tensile stress of the 2 nd resin is greater than the compressive stress of the 1 st resin.

8. The imaging device for an endoscope according to any one of claims 5 to 7,

the 1 st optical member and the 2 nd optical member are each a molded article.

9. An endoscope, characterized in that,

the endoscope includes the imaging device for an endoscope according to any one of claims 5 to 8.

Technical Field

The present invention relates to a method of manufacturing an imaging device for an endoscope in which a plurality of optical elements are stacked, and an endoscope including the imaging device for an endoscope in which a plurality of optical elements are stacked.

Background

In order to reduce the invasion, it is important to reduce the size, particularly the diameter, of the imaging device for an endoscope disposed at the distal end portion of the endoscope.

International publication No. 2017-212520 discloses an image pickup device having an optical portion composed of a wafer-level laminate as a method for efficiently manufacturing the image pickup device. The wafer-level optical portion is manufactured by cutting and singulating a bonded wafer in which a plurality of optical wafers each including a plurality of optical elements are bonded. A solid 1 st adhesive material and a liquid 2 nd adhesive material for adjusting the optical path length are used for bonding an optical wafer.

The 2 nd adhesive material shrinks by a curing reaction. Due to the contraction force of the 2 nd adhesive material, the 1 st adhesive material may be compressed to shorten the optical path length or break the optical portion.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2017-212520

Disclosure of Invention

Problems to be solved by the invention

An object of an embodiment of the present invention is to provide a method for manufacturing an image pickup apparatus for an endoscope having excellent optical characteristics and high reliability, and an endoscope including the image pickup apparatus for an endoscope having excellent optical characteristics and high reliability.

Means for solving the problems

The method for manufacturing an imaging device for an endoscope according to an embodiment of the present invention includes: a wafer production step of producing a 1 st optical wafer and a 2 nd optical wafer, the 1 st optical wafer having a 1 st main surface and a 2 nd main surface opposed to the 1 st main surface and including a plurality of 1 st optical elements, the 2 nd optical wafer including a plurality of 2 nd optical elements, the plurality of 2 nd optical elements having a 3 rd main surface and a 4 th main surface opposed to the 3 rd main surface, and each of the 3 rd main surfaces having a spacer; a 1 st resin disposing step of disposing a plurality of walls made of the 1 st resin, having a height higher than that of the spacers, on the 2 nd main surface or the 3 rd main surface so as to surround the respective optical paths without a gap; a sealing step of sealing the optical path by sandwiching the wall between the 2 nd main surface and the 3 rd main surface and pressing the 2 nd main surface and the 3 rd main surface; a 2 nd resin disposing step of filling an uncured and liquid 2 nd resin between the 2 nd main surface and the 3 rd main surface around the wall; a curing step of curing the 2 nd resin, thereby shrinking the 2 nd resin and fixing the 2 nd main surface and the 3 rd main surface in a state where a space is defined by the spacer; a singulation step of cutting a bonded wafer in which the 1 st optical wafer and the 2 nd optical wafer are fixed by the 2 nd resin to produce an optical portion; and an image pickup unit disposing step of disposing an image pickup unit for receiving the subject image condensed by the optical unit on the optical unit.

An imaging device for an endoscope according to an embodiment includes an optical unit and an imaging unit that receives a subject image condensed by the optical unit, the optical unit including: a 1 st optical member having a 1 st main surface and a 2 nd main surface opposed to the 1 st main surface; a 2 nd optical member having a 3 rd main surface and a 4 th main surface opposed to the 3 rd main surface, the 3 rd main surface being opposed to the 2 nd main surface, the 3 rd main surface around the optical path having a spacer that defines a distance between the 2 nd main surface and the 3 rd main surface; a 1 st resin which constitutes a wall that seals the optical path between the 2 nd main surface and the 3 rd main surface, has the same height as the spacer, and surrounds the optical path without a gap; and a 2 nd resin filled around the wall, having the same height as the spacer, the 1 st resin having a hardness smaller than that of the 2 nd resin.

An endoscope according to an embodiment includes an endoscope image pickup device including an optical unit and an image pickup unit that receives an object image condensed by the optical unit, the optical unit including: a 1 st optical member having a 1 st main surface and a 2 nd main surface opposed to the 1 st main surface; a 2 nd optical member having a 3 rd main surface and a 4 th main surface opposed to the 3 rd main surface, the 3 rd main surface being opposed to the 2 nd main surface, the 3 rd main surface around the optical path having a spacer that defines a distance between the 2 nd main surface and the 3 rd main surface; a 1 st resin which constitutes a wall that seals the optical path between the 2 nd main surface and the 3 rd main surface, has the same height as the spacer, and surrounds the optical path without a gap; and a 2 nd resin filled around the wall, having the same height as the spacer, the 1 st resin having a hardness smaller than that of the 2 nd resin.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the embodiments of the present invention, it is possible to provide a method for manufacturing an image pickup apparatus for an endoscope having excellent optical characteristics and high reliability, and an endoscope including the image pickup apparatus for an endoscope having excellent optical characteristics and high reliability.

Drawings

Fig. 1 is a configuration diagram of an endoscope system including an endoscope according to an embodiment.

Fig. 2 is a perspective view of the imaging device according to the embodiment.

Fig. 3 is a sectional view taken along the line III-III of fig. 2.

Fig. 4 is a sectional view taken along line VI-VI of fig. 3.

Fig. 5 is an exploded view of the image pickup apparatus of the embodiment.

Fig. 6 is a flowchart of a method of manufacturing the imaging device according to the embodiment.

Fig. 7 is a sectional view for explaining a method of manufacturing the imaging device according to the embodiment.

Fig. 8 is a sectional view for explaining a method of manufacturing the imaging device according to the embodiment.

Fig. 9 is a perspective view for explaining a method of manufacturing the imaging device according to the embodiment.

Fig. 10 is a sectional view for explaining a method of manufacturing the imaging device according to the embodiment.

Fig. 11 is a sectional view for explaining a method of manufacturing the imaging device according to the embodiment.

Fig. 12 is a sectional view for explaining a method of manufacturing the imaging device according to the embodiment.

Fig. 13 is a sectional view for explaining a method of manufacturing the imaging device according to the embodiment.

Fig. 14 is a sectional view of an optical portion of the imaging device according to modification 1.

Fig. 15 is a sectional view of an optical portion of an imaging device according to modification 2.

Fig. 16 is a sectional view for explaining a method of manufacturing the imaging device according to modification 3.

Fig. 17 is a sectional view of an imaging device according to modification 4.

Detailed Description

< endoscope >

The endoscope 9 of the embodiment shown in fig. 1 constitutes an endoscope system 6 together with the processor 5A and the monitor 5B.

The endoscope 9 includes an insertion portion 3, a grip portion 4 disposed at a proximal end portion of the insertion portion 3, a universal cable 4B extending from the grip portion 4, and a connector 4C disposed at a proximal end portion of the universal cable 4B. The insertion portion 3 includes a distal end portion 3A, a bendable portion 3B extending from the distal end portion 3A and being bendable to change the direction of the distal end portion 3A, and a soft portion 3C extending from the bendable portion 3B. A rotatable angle knob 4A is disposed on the grip portion 4, and the angle knob 4A is an operation portion for the surgeon to operate the bending portion 3B.

The universal cable 4B is connected to the processor 5A through a connector 4C. The processor 5A controls the entire endoscope system 6, and performs signal processing on the image pickup signal and outputs the image pickup signal as an image signal. The monitor 5B displays the image signal output from the processor 5A as an endoscopic image. The endoscope 9 is a soft endoscope, but may be a hard endoscope. Further, the endoscope 9 can be used for medical use as well as industrial use.

As described later, the imaging device 1 for an endoscope (hereinafter, also referred to as "imaging device") disposed at the distal end portion 3A has excellent optical characteristics and high reliability. Therefore, the endoscope 9 has good optical characteristics and high reliability.

< image pickup device >

As shown in fig. 2 to 5, the imaging device 1 for an endoscope according to the embodiment includes an optical unit 5 and an imaging unit 50. The optical section 5 is a laminate in which a plurality of optical elements 10-40 are laminated.

In the following description, drawings based on the respective embodiments are schematic drawings, and the relationship between the thickness and the width of each portion, the ratio of the thicknesses of the respective portions, the relative angle, and the like are different from those in the actual case. There are cases where the drawings include portions having different dimensional relationships or ratios from each other. Some of the components may not be illustrated.

As described later, the optical portion 5 is an optical portion composed of a wafer level laminate manufactured by cutting a bonded wafer. Therefore, the optical portion 5 is a rectangular parallelepiped, and the cross-sectional shapes of the optical elements 10 to 40 in the direction orthogonal to the optical axis are all rectangular, and the outer dimensions are the same. The optical elements 10-40 are laminated such that the optical axes O thereof coincide with each other.

The optical element 10 as the 1 st optical member has a 1 st main surface 10SA and a 2 nd main surface 10SB opposed to the 1 st main surface 10 SA. In the optical element 10, the 1 st main surface 10SA is a flat surface, and the 2 nd main surface 10SB is a plano-concave lens which is a concave lens.

The optical element 20 as the 2 nd optical member has a 3 rd main surface 20SA and a 4 th main surface 20SB opposed to the 3 rd main surface 20 SA. In the optical element 20, the 3 rd main surface 20SA is a flat surface, but the 4 th main surface is a plano-convex lens which is a convex lens.

The optical element 30 as the 3 rd optical member has a 5 th main surface 30SA and a 6 th main surface 30SB opposed to the 5 th main surface 30 SA. The optical element 30 is a convex flat lens.

The optical element 40 as the 4 th optical member has a 7 th main surface 40SA and an 8 th main surface 40SB opposed to the 7 th main surface 40 SA. The optical element 40 is an infrared cut filter that removes infrared rays (for example, light having a wavelength of 700nm or more). The optical filter may be a glass filter having a surface provided with a band pass filter that transmits only light having a predetermined wavelength and cuts light having an unnecessary wavelength.

The optical element 20 has a spacer 25 as a column having a height H25 on the 3 rd main surface 20 SA. The optical element 30 has a spacer 35 as a column having a height H35 on the 5 th main surface 30 SA. The optical element 40 has spacers 45, which are pillars having a height H45, on the 7 th main surface 40 SA.

As shown in fig. 4, a 1 st resin 60A in a shape of a mirror frame surrounding the optical path OP without a gap and a 2 nd resin 70A filling the periphery of the 1 st resin 60A are disposed around the optical path OP between the 2 nd main surface 10SB and the 3 rd main surface 20SA facing the 2 nd main surface 10 SB.

Similarly, a 1 st resin 60B in a frame shape surrounding the optical path OP without a gap and a 2 nd resin 70B filled around the 1 st resin 60B are disposed between the 4 th main surface 20SB and the 5 th main surface 30 SA. Between the 6 th main surface 30SB and the 7 th main surface 40SA, a 1 st resin 60C in a frame shape surrounding the optical path OP without a gap and a 2 nd resin 70C filling the periphery of the 1 st resin 60C are arranged.

The distance between the 2 nd main surface 10SB and the 3 rd main surface 20SA is defined by the height H25 of the spacer 25. Therefore, the height H60A of the 1 st resin 60A and the height H70A of the 2 nd resin 70A are the same as the height H25 of the spacer 25.

Similarly, the height H60B of the 1 st resin 60B and the height H70B of the 2 nd resin 70B are the same as the height H35 of the spacer 35. The height H60C of the 1 st resin 60C and the height H70C of the 2 nd resin 70C are the same as the height H45 of the spacer 45.

The 1 st resins 60A to 60C are the same kind of resin, and the 2 nd resins 70A to 70C are the same kind of resin. Hereinafter, when referring to a plurality of similar components, the last 1 letter may be omitted. For example, the 1 st resins 60A to 60C are referred to as the 1 st resin 60, respectively.

The 1 st resin 60 is a soft resin having a hardness smaller than that of the 2 nd resin 70. For example, the Young's modulus of the 1 st resin 60 made of silicone resin is 0.1GPa, and the Young's modulus of the 2 nd resin 70 made of ultraviolet-curable epoxy resin is 2.0 GPa. Young's modulus (modulus of elasticity) was measured at 25 ℃ in accordance with ASTM-D638.

The optical portion 5 also includes other optical elements such as an flare stop and a brightness stop, which are not shown. Further, any optical element may be a spacer element having a through hole serving as an optical path in the center. That is, the configurations of the optical elements, the spacers, the number of diaphragms, and the like of the optical portion of the embodiment are set according to the specifications.

The imaging unit 50 includes an imaging element 51 and a cover glass 52. The image pickup device 51 has a light receiving unit 51A that receives the object image condensed by the optical unit 5.

As described later, the optical elements 20 to 40 are molded products. For example, the optical element 20 is a polycarbonate resin having the spacer 25 formed on the 3 rd main surface 20SA and the convex lens formed on the 4 th main surface 20 SB.

In the imaging device 1, in order to reduce the invasion of the endoscope 9, the cross section of the optical element 10 in the direction perpendicular to the optical axis O is, for example, 1mm square or less and is extremely thin, and therefore, it is difficult to bond the plurality of optical elements 10 to 40.

As described later, in the imaging device 1, the 2 nd resin 70 as a curable resin is cured and contracted, thereby applying tensile stress (force to stretch each main surface) to the 4 th main surface 20SB and the 5 th main surface 30 SA. Therefore, the distance between the 4 th main surface 20SB and the 5 th main surface 30SA is reduced, and the 4 th main surface 20SB abuts against the spacer 35. The tensile stress decreases as the 2 nd resin 70 is cured and shrunk until the 4 th main surface 20SB comes into contact with the spacer 35.

The residual stress (hereinafter referred to as "shrinkage force") of the cured 2 nd resin in the imaging device 1 is smaller than that in the imaging device of the conventional structure in which the 4 th main surface is brought into contact with the spacer before the 2 nd resin starts to cure and shrink and the gap between the 4 th main surface and the 5 th main surface is not reduced by the curing and shrinking.

In addition, in the present invention, since the 1 st resin 60 having the same thickness as the uncured 2 nd resin 70 is soft, when the 2 nd resin 70 is cured and shrunk, the 1 st resin 60 shrinks in cooperation with the shrinkage. Therefore, the 1 st resin 60 applies a compressive stress (a force pressing each main surface) to the 4 th main surface 20SB and the 5 th main surface 30SA, but the compressive stress of the 1 st resin 60 is smaller than the tensile stress of the 4 th resin.

In addition, it is not practical to analyze and confirm that the 2 nd resin 70 is a resin after curing shrinkage. That is, there is no appropriate means for measurement and analysis.

Further, the endoscope 9 including the imaging device 1 is small in diameter and thus less invasive, and the bonded interfaces of the optical elements 10 to 40 are less likely to peel off, so that the manufacturing is easy and the reliability is high.

< method for manufacturing image pickup device for endoscope >

A method for manufacturing the endoscopic imaging apparatus according to the present embodiment will be described with reference to a flowchart shown in fig. 6. In addition, the 1 st optical element 10 and the 2 nd optical element 20 will be described below. For example, the method of bonding the 2 nd optical element 20 and the 3 rd optical element 30 and the method of bonding the 3 rd optical element 30 and the 4 th optical element 40 are substantially the same as the method of bonding the 1 st optical element 10 and the 2 nd optical element 20.

< step S10 > wafer production Process

As shown in fig. 7, a 1 st optical wafer 10W is produced, and the 1 st optical wafer 10W includes a plurality of 1 st optical elements 10 having a 1 st main surface 10SA and a 2 nd main surface 10SB opposed to the 1 st main surface 10 SA. As shown in fig. 8, a 2 nd optical wafer 20W is produced, the 2 nd optical wafer 20W including a plurality of 2 nd optical elements 20, the plurality of 2 nd optical elements 20 having a 3 rd main surface 20SA and a 4 th main surface 20SB opposed to the 3 rd main surface 20SA, and spacers 25 provided on the 3 rd main surface 20SA, respectively.

The optical wafers 10W and 20W are made of a transparent hard resin. For example, optical wafers 10W and 20W including a plurality of optical elements 10 and 20 having a predetermined shape are manufactured by molding an optical resin by an injection molding method or a press molding method. The transparent hard resin is, for example, polycarbonate having a Young's modulus of 5 GPa.

A plurality of spacers 25 each having a height H25 and being a column are molded on the 3 rd main surface 20SA of the optical wafer 20W. The plurality of spacers 25 are arranged so as to surround the optical path. The height H25 of the spacer 25 manufactured by the molding is accurately managed to be a predetermined value due to the shape of the transfer molding.

The optical wafers 10W and 20W may be hybrid lens wafers in which lenses and spacers made of resin are disposed on glass wafers parallel to a flat plate.

The structure of the optical wafer, i.e., the material, the shape, number, arrangement, and outer shape of the optical elements to be arranged are designed according to specifications.

< step S20 > 1 st resin disposing step

As shown in fig. 9, on the 3 rd main surface 20SA of the 2 nd optical wafer 20W, a plurality of frame-shaped walls 60A made of the 1 st resin and surrounding the optical paths without gaps are disposed. The height H60A of wall 60A is greater than the height H25 of spacer 25.

The wall 60A may be disposed on the 2 nd main surface 10SB of the 1 st optical wafer 10W.

The wall 60A may be provided by a screen printing method or an ink-jet method, but it is preferable to provide the wall 60A using a film made of the 1 st resin. For example, the walls 60A of the 1 st resin, which are held by the holding film and patterned into a predetermined shape, are transferred to the optical wafer 10W or the optical wafer 20W.

< step S30 > sealing Process

As shown in fig. 10, the optical path is sealed by pressure-bonding the 2 nd main surface 10SB of the 1 st optical wafer 10W and the 3 rd main surface 20SA of the 2 nd optical wafer 20W with the plurality of walls 60A interposed therebetween. For example, when the 1 st optical wafer 10W and the 2 nd optical wafer 20W are pressed at 80 ℃. In the case where the 1 st resin is adhesive, the 1 st optical wafer 10W and the 2 nd optical wafer 20W are temporarily fixed only by pressure-bonding the 1 st optical wafer 10W and the 2 nd optical wafer 20W at room temperature.

Further, since the 1 st resin is soft, the upper surface of the spacer 25 of the 2 nd optical wafer 20W may temporarily abut on the 2 nd main surface 10SB when being pressure-bonded. However, when left after being pressure-bonded, the 1 st resin returns to the height H60A at the time of installation by a compressive stress intended to return to the original height. Therefore, a gap is generated between the spacer 25 and the 2 nd main surface 10 SB.

For example, when the height H60A of the wall 60A is 50 μm and the height H25 of the spacer 25 is 48 μm, a gap of 2 μm is generated between the spacer 25 and the 2 nd main surface 10 SB.

< step S40 > 2 nd resin disposing step

Uncured 2 nd resin 70A is filled between the 2 nd main surface 10SB and the 3 rd main surface 20SA around the wall 60A. Although the uncured 2 nd resin 70A is in a liquid state, the 2 nd resin 70A does not enter the optical path because the optical path is surrounded by the wall 60A made of the 1 st resin. When the liquid 2 nd resin 70A is disposed between the 2 nd main surface 10SB and the 3 rd main surface 20SA, the capillary phenomenon is preferably utilized.

< step S50 > 2 nd resin curing step

By curing the 2 nd resin 70A, the 2 nd resin 70A shrinks, the distance between the 2 nd main surface 10SB and the 3 rd main surface 20SA decreases, and the resin is fixed at a predetermined distance by the spacer 25.

When the 2 nd resin 70A is an ultraviolet curable resin, ultraviolet rays are irradiated, and when the 2 nd resin 70A is a thermosetting resin, heat treatment is performed. The 2 nd resin 70A becomes solid after being cured, and bonds the 1 st optical wafer 10W and the 2 nd optical wafer 20W.

That is, the 1 st resin constituting the wall 60A is a soft resin having a hardness smaller than that of the 2 nd resin 70A. Therefore, when the 2 nd resin 70A is shrunk by the curing process, the wall 60A is compressed and deformed by the tensile stress of the 2 nd resin 70A, and therefore, the 2 nd main surface 10SB is brought into contact with the spacer 25.

As described above, when the height H60A of the wall 60A is 50 μm and the height H25 of the spacer 25 is 48 μm, a gap of 2 μm is provided between the spacer 25 and the 2 nd main surface 10 SB. The thickness of the 2 nd resin 70A filled between the 2 nd main surface 10SB and the 3 rd main surface 20SA is 50 μm.

The height H60A of the wall 60A is set based on the curing shrinkage rate of the 2 nd resin 70A and the height H25 of the spacer 25. For example, when the shrinkage amount due to the curing reaction of the 2 nd resin 70A is 1% or more and 10% or less, the height H60A of the wall 60A disposed in the 1 st resin disposing step S20 is 101% or more and 110% or less of the height H25 of the spacer 25.

Preferably, the 1 st resin is a soft resin having a young's modulus of 1GPa or less, and the cured 2 nd resin 70A is a hard resin having a young's modulus of more than 1 GPa. More preferably, the Young's modulus of the 1 st resin is 0.5GPa or less, and the Young's modulus of the 2 nd resin 70A is 2GPa or more.

The spacer 25 is harder than the 2 nd resin 70A. The spacer 25 is made of, for example, a hard resin having a young's modulus of more than 2 GPa.

The 1 st resin is selected from soft silicone resin, rubber, and the like. The 2 nd resin 70A and the spacer 25 (the 2 nd optical element 20) are selected from epoxy resin, polystyrene resin, melamine resin, polycarbonate resin, and the like.

If the Young's modulus of the resin is in the above range, when the 2 nd resin 70A contracts, the wall 60A made of the 1 st resin is compressively deformed, and the optical path length is defined by the spacer 25.

The cured 2 nd resin 70A is restricted from shrinking by the spacers 25. Therefore, the 2 nd resin 70A applies a tensile stress, which is a force in a direction to bring the 2 nd main surface 10SB and the 3 rd main surface 20SA closer to each other. On the other hand, the compressed 1 st resin applies a compressive stress, which is a force in a direction separating the 2 nd main surface 10SB and the 3 rd main surface 20 SA.

The shrinkage force of the 2 nd resin 70A (tensile stress remaining in the 2 nd resin 70A) is smaller than that in the case where the 1 st resin is not required. Therefore, a large contraction force does not act on the bonding interface of the optical portion 5, and therefore, the bonding reliability is high.

In addition, the tensile stress of the 2 nd resin 70A is designed to be larger than the compressive stress of the 1 st resin. Therefore, when the 2 nd resin 70A is cured and shrunk, the distance between the 2 nd main surface 10SB and the 3 rd main surface 20SA becomes small.

< step S60 > singulation step

The optical portion 5 is produced by singulating the bonded wafer 5W in which the 1 st optical wafer 10W and the 2 nd optical wafer 20W are fixed by the 2 nd resin 70A.

As shown in fig. 13, the bonded wafer is cut along cutting lines CL by a dicing blade, and the plurality of optical portions 5 are singulated. As for the cutting, laser cutting or plasma cutting may also be used.

The optical portion 5 is a rectangular parallelepiped, but may be singulated into, for example, a hexagonal prism by arranging the cutting lines CL of the bonded wafer. The optical portion 5 may be formed into a cylindrical shape by processing after singulation. That is, the shape of the optical portion 5 is not limited to a rectangular parallelepiped.

< step S70 > image pickup section disposing step

The optical unit 5 is provided with an imaging unit 50 that receives the subject image collected by the optical unit 5. The imaging unit 50 is manufactured by forming the light receiving part 51A on an imaging element wafer made of a silicon wafer by a known semiconductor manufacturing technique, bonding a glass wafer for protecting the light receiving part 51A, and then cutting.

For example, the imaging unit 50 including the optical portion 5 may be produced by bonding an imaging device wafer to a bonding wafer including a plurality of optical portions 5 and then cutting the bonding wafer. Further, the plurality of imaging units 50 may be bonded to a bonding wafer including the plurality of optical units 5 and then cut. That is, the singulation step S60 and the imaging section disposing step S70 may be performed in reverse order or simultaneously.

The curing shrinkage of the 2 nd resin 70A varies depending on curing conditions, changes with time after curing, and the like. However, in the optical portion 5, the distance between the 2 nd main surface 10SB and the 3 rd main surface 20SA is defined by the height H25 of the spacer 25. In the imaging device 1, the optical path length of the optical unit 5 is stable, and thus the optical characteristics are good.

Further, the shrinkage force (tensile stress remaining in the 2 nd resin 70A) generated by curing of the 2 nd resin 70A is smaller than that in the case where the 1 st resin 60 is not required, and therefore, the adhesion reliability of the adhesion interface is high. Therefore, the imaging device 1 and the endoscope 9 including the imaging device 1 have high reliability.

The imaging device 1 further includes an optical unit 5 in which 4 optical elements 10 to 40 are laminated. However, if at least 2 optical elements are laminated in the same manner as the optical portion 5, it is apparent that the same effect as the image pickup device 1 is obtained.

That is, the endoscope image pickup device of the present invention includes an optical unit and an image pickup unit that receives an object image condensed by the optical unit, the optical unit including: a 1 st optical member having a 1 st main surface and a 2 nd main surface opposed to the 1 st main surface; a 2 nd optical member having a 3 rd main surface and a 4 th main surface opposed to the 3 rd main surface, the 3 rd main surface being opposed to the 2 nd main surface, the 3 rd main surface around the optical path having a spacer for defining a gap between the 2 nd main surface and the 3 rd main surface; a 1 st resin which constitutes a wall which seals the optical path between the 2 nd main surface and the 3 rd main surface, has the same height as the spacer, and surrounds the optical path without a gap; and a 2 nd resin filled around the wall, having the same height as the spacer, the 1 st resin having a hardness smaller than that of the 2 nd resin.

The method for manufacturing an imaging device for an endoscope according to the present invention includes the steps of: a wafer production step of producing a 1 st optical wafer and a 2 nd optical wafer, the 1 st optical wafer having a 1 st main surface and a 2 nd main surface opposed to the 1 st main surface and including a plurality of 1 st optical elements, the 2 nd optical wafer including a plurality of 2 nd optical elements, the plurality of 2 nd optical elements having a 3 rd main surface and a 4 th main surface opposed to the 3 rd main surface, and each of the 3 rd main surfaces having a spacer; a 1 st resin disposing step of disposing a plurality of walls made of the 1 st resin, having a height higher than that of the spacers, and surrounding the respective optical paths without a gap, on the 2 nd main surface or the 3 rd main surface; a sealing step of sealing the optical path by sandwiching the wall between the 2 nd main surface and the 3 rd main surface and pressing the 2 nd main surface and the 3 rd main surface; a 2 nd resin disposing step of filling an uncured and liquid 2 nd resin between the 2 nd main surface and the 3 rd main surface around the wall; a curing step of curing the 2 nd resin, thereby shrinking the 2 nd resin and fixing the 2 nd main surface and the 3 rd main surface in a state where a space is defined by the spacer; a singulation step of cutting a bonded wafer in which the 1 st optical wafer and the 2 nd optical wafer are fixed by the 2 nd resin to produce an optical portion; and an image pickup unit disposing step of disposing an image pickup unit for receiving the subject image condensed by the optical unit on the optical unit.

< modification example >

The imaging devices 1A to 1D and the imaging devices 1A to 1D of the modified examples are similar to the imaging device 1 and the imaging device 1 in the manufacturing method and have the same effects, and therefore, the same reference numerals are given to the structural elements having the same functions, and the description thereof is omitted.

< modification 1 >

As shown in fig. 14, in the imaging device 1A of modification 1, 2 prism spacers 25 are arranged at rotationally symmetric positions around the optical axis O. Further, the wall 60A made of the 1 st resin surrounding the optical path OP is annular.

< modification 2 >

As shown in fig. 15, in the imaging apparatus 1B of modification 2, 6 triangular-prism spacers 25 are arranged at rotationally symmetric positions around the optical axis O. Further, the wall 60A made of the 1 st resin surrounding the optical path OP is hexagonal.

That is, the spacers 25 may be provided so as to define the optical path length, which is the interval, and the shape and number thereof may be appropriately selected. Note that the shape of the wall 60A made of the 1 st resin may be appropriately selected as long as it surrounds the optical path OP without a gap.

< modification 3 >

As shown in fig. 16, a plurality of walls 60A made of the 1 st resin provided on the 2 nd optical wafer 20W used to manufacture the imaging device 1C of modification 3 are connected.

The wall 60A includes a main portion 61 surrounding the optical path OP and a connecting portion 62 connecting the plurality of main portions 61. Height H61 of main portion 61 is greater than height H25 of spacer 25. On the other hand, the height H62 of the connecting portion 62 is smaller than the height H25 of the spacer 25. Even if the optical path OP is sealed by the main portion 61, there is a gap between the connecting portion 62 and the 2 nd main surface 10SB of the 1 st optical wafer 10W. Therefore, the 2 nd resin 70A can be filled in the gap.

Since the walls 60A are connected, the imaging device 1C can be easily disposed on the 2 nd optical wafer 20W.

< modification 4 >

As shown in fig. 17, an imaging device 1D according to modification 4 is a so-called lateral type in which a light receiving unit 51A of an imaging element 51 is arranged parallel to an optical axis O of an optical unit 5.

The object image collected by the optical unit 5 is reflected by the prism 53 and enters the light receiving unit 21A of the image pickup device 51.

The endoscopes 9A to 9D provided with the imaging devices 1A to 1D have the effects of the endoscope 9 provided with the imaging device 1, and certainly have the effects of the imaging devices 1A to 1D.

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

Description of the reference symbols

1. 1A-1D … endoscope imaging device

1X … optical module

5 … optical part

5W … bonded wafer

6 … endoscope system

9 … endoscope

10 … optical element No. 1

10W, 20W, 30W … No. 1 optical wafer

20 … optical element 2

25 … spacer

30 st 30 … optical element 3

35 … spacer

40 … No. 4 optical element

45 … spacer

50 … image pickup part

51 … image pickup element

52 … glass cover

53 … prism

60 … wall (resin No. 1)

70 … resin 2.