WO2019138463A1

WO2019138463A1 - Method for manufacturing optical unit, optical unit, and endoscope

Info

Publication number: WO2019138463A1
Application number: PCT/JP2018/000286
Authority: WO
Inventors: 健介須賀; 紀幸藤森; 和也前江田
Original assignee: オリンパス株式会社
Priority date: 2018-01-10
Filing date: 2018-01-10
Publication date: 2019-07-18

Abstract

This method for manufacturing an optical unit 1 is provided with: a step for preparing a plurality of element wafers 11W to 14W; a step for stacking the plurality of element wafers 11W to 14W to prepare a joint wafer 10W; a step for cutting the joint wafer 10W to prepare a laminate lens 10 in which a plurality of optical elements 11 to 14 that include a first optical element 11 having a first primary surface 11SA, are laminated; a step for preparing a lens frame 40 having a through-hole H40; and an assembly step for inserting the laminate lens 10 into the through-hole H40. The first element wafer 11W including the first optical element 11 prepared in the element wafer step is prepared through a molding method, a stepped part S10 is present around the first primary surface 11SA of the first optical element 11, and a front opening 40SA of the lens frame 40 is fitted to the stepped part S10 in the assembly step.

Description

Optical unit manufacturing method, optical unit, and endoscope

The present invention relates to a method of manufacturing an optical unit in which a plurality of optical elements are stacked, an optical unit in which a plurality of optical elements are stacked, and an endoscope having an optical unit in which a plurality of optical elements are stacked.

It is important to miniaturize the optical unit disposed at the tip of the endoscope for reducing the invasiveness, in particular, to reduce the diameter.

Japanese Patent Laid-Open Publication No. 2012-18993 discloses an optical unit made of a wafer level laminate as a method of efficiently manufacturing a small-sized optical unit. A wafer level laminate is manufactured by cutting and singulating a bonded wafer in which a plurality of element wafers each including a plurality of elements are stacked and adhered.

The wafer level laminate has a risk of breakage particularly when the aspect ratio (dimension in the optical axis direction / dimension in the optical axis orthogonal direction) is high because mechanical strength is not high.

WO 2017/73440 discloses an imaging unit in which a wafer level optical unit is accommodated in a housing and a gap is filled with a sealing resin. In order to prevent the wafer level optical unit from protruding from the front surface of the housing, there is a step portion on the outer peripheral portion of the forefront optical member, and the step portion is filled with the sealing resin.

In order to form the stepped portion, two-step dicing (step dicing) is performed in the bonded wafer cutting process. For example, a groove is first formed on the top wafer along the cutting line using a first dicing plate. Next, the bonded wafer is cut along the cutting lines using a second dicing plate that is narrower than the first dicing plate, and separated into optical units.

However, in the formation of the step portion by dicing, chipping may occur and the optical characteristics may be degraded. Also, step dicing using two types of dicing plates is a complicated process.

International Publication No. 2017/73440

An embodiment of the present invention is an endoscope having a method of manufacturing an optical unit which is easy to manufacture and good in optical characteristics, an optical unit which is easy to manufacture and good in optical characteristics, and an optical unit which is easy to manufacture and good in optical characteristics. Intended to be provided.

A method of manufacturing an optical unit according to an embodiment is a method of manufacturing an optical unit disposed at a tip end portion of an endoscope, which includes the steps of: manufacturing a plurality of element wafers including the respective optical elements; A step of laminating the wafer and manufacturing a bonded wafer, cutting the bonded wafer, and having a front surface and a back surface opposite to the front surface, the first main surface being the front surface and the first main surface Manufacturing a laminated lens in which a plurality of optical elements including a first optical element having an opposing second main surface are laminated, and manufacturing a lens frame having a through hole with a front opening and a rear opening Manufacturing the element wafer, comprising the steps of: assembling and inserting the laminated lens into the through hole from the rear opening and fixing the laminated lens to the lens frame; The first element wafer containing Produced by law, the there is a step portion around the first main surface of the first optical element, in the assembly process, the front opening of the lens frame, wherein the stepped portion is fitted.

The optical unit according to the embodiment is an optical unit disposed at the tip of an endoscope, and the method of manufacturing the optical unit includes the steps of: producing a plurality of element wafers including the respective optical elements; And laminating a front surface and a rear surface facing the front surface, wherein the first main surface which is the front surface and the first main surface are stacked. Manufacturing a laminated lens in which a plurality of optical elements including a first optical element having a surface and a second principal surface facing each other are laminated, and a lens frame having a through hole with a front opening and a rear opening Manufacturing the element wafer, comprising the steps of: manufacturing; assembling the laminated lens inserted into the through hole from the rear opening; and fixing the lens to the lens frame; The first element wafer including the optical element is Produced by Rudo molding, wherein there is a step portion around the first main surface of the first optical element, in the assembly process, the front opening of the lens frame, wherein the stepped portion is fitted.

The endoscope according to the embodiment includes an optical unit disposed at the tip, and a method of manufacturing the optical unit includes the steps of producing a plurality of element wafers including the respective optical elements, and the plurality of element wafers And laminating the bonded wafer, cutting the bonded wafer, and having a front surface and a back surface facing the front surface, the first main surface being the front surface facing the first main surface. Manufacturing a laminated lens in which a plurality of optical elements including a first optical element having a second main surface to be laminated are laminated, and manufacturing a lens frame having a through hole with a front opening and a rear opening And an assembling step of inserting the laminated lens into the through hole from the rear opening and fixing it to the lens frame, and the first optical element manufactured in the step of manufacturing the element wafer The first element wafer containing is molded by a molding method More the produced, the there is a step portion around the first main surface of the first optical element, in the assembly process, the front opening of the lens frame, wherein the stepped portion is fitted.

It is a perspective view of the endoscope of an embodiment. It is a front view of the optical unit of an embodiment. FIG. 3 is a cross-sectional view of the optical unit of the embodiment taken along the line III-III of FIG. 2; It is a flowchart for demonstrating the manufacturing method of the optical unit of embodiment. It is sectional drawing for demonstrating the manufacturing method of the optical unit of embodiment. It is sectional drawing for demonstrating the manufacturing method of the optical unit of embodiment. It is a cross-sectional perspective view for demonstrating the manufacturing method of the optical unit of embodiment. It is sectional drawing for demonstrating the manufacturing method of the optical unit of embodiment. It is sectional drawing for demonstrating the manufacturing method of the optical unit of embodiment. It is a perspective view for demonstrating the manufacturing method of the optical unit of embodiment. It is sectional drawing for demonstrating the manufacturing method of the optical unit of the modification 1 of embodiment. It is a front view of the optical unit of the modification 2 of embodiment. FIG. 11 is a cross-sectional view of the optical unit of the modified example 2 of the embodiment along the line XI-XI in FIG. 10;

As shown in FIG. 1, the endoscope 9 of the embodiment constitutes an endoscope system 6 with a processor 5A and a monitor 5B. The endoscope 9 has an optical unit 1 at the distal end 3A of the insertion portion 3. The light collected by the optical unit 1 of the embodiment is, for example, incident on an imaging unit and converted into an imaging signal.

The endoscope 9 includes an elongated insertion portion 3, a grip portion 4 disposed at a proximal end of the insertion portion 3, a universal cord 4B extended from the grip portion 4, and a proximal end portion of the universal cord 4B. And a connector 4C disposed. The insertion portion 3 includes a distal end portion 3A in which the optical unit 1 is disposed, a bendable portion 3B extending at the proximal end of the distal end portion 3A, and a bendable portion 3B for changing the direction of the distal end portion 3A And a flexible portion 3C extended to the proximal end of 3B. The grip portion 4 is provided with a pivoting angle knob 4A which is an operation portion for a surgeon to operate the bending portion 3B.

A connector 4C disposed at the proximal end of the universal cord 4B is connected to the processor 5A. The processor 5A controls the entire endoscope system 6, performs signal processing on an imaging signal output from the imaging unit, and outputs an image signal. The monitor 5B displays the image signal output by the processor 5A as an endoscopic image. Although the endoscope 9 is a flexible endoscope, the endoscope of the present invention may be a rigid endoscope, and its use may be medical or industrial.

As described later, the compact optical unit 1 is easy to manufacture and has good optical characteristics. For this reason, the endoscope 9 is easy to manufacture and the endoscope image which can be displayed is excellent.

<Configuration of Optical Unit>
As shown in FIGS. 2 and 3, the optical unit 1 of the present embodiment includes a laminated lens 10 and a lens frame 40 in which the laminated lens 10 is inserted.

Note that the drawings based on each embodiment are schematic, and it is noted that the relationship between the thickness and width of each part, the thickness ratio of each part, the relative angle, etc. are different from the actual ones. There should be cases where parts of the drawings may differ in their dimensional relationships and proportions. In addition, illustration of some components and assignment of symbols may be omitted.

The laminated lens 10 having the optical axis O, in which the plurality of optical elements 11 to 14 and 31 to 33 are laminated, is a wafer level laminated body manufactured by cutting the bonded wafer 10W (see FIG. 6). For this reason, the laminated lens 10 of the present embodiment is a substantially rectangular parallelepiped having the front surface 10SA and the rear surface 10SB facing the front surface 10SA, and the four side surfaces 10SS are cut surfaces. The optical elements 11 to 14 and the like each have a rectangular cross-sectional shape in the direction orthogonal to the optical axis and the same outer size. The optical elements 11 to 14 each having an optical axis O are stacked such that the optical axes O coincide with each other. In addition, in order to reduce the invasiveness of the endoscope 9, the outer dimension of the multilayer lens 10 in the direction orthogonal to the optical axis is extremely thin, for example, 5 mm or less. On the other hand, the multilayer lens 10 has a high aspect ratio structure in which the outer dimension in the optical axis direction is twice or more the outer dimension in the optical axis orthogonal direction.

The optical element 11, which is the first optical element disposed at the front of the multilayer lens 10, has a second main surface 11SA constituting the front surface 10SA and a second main surface 11SA facing the first main surface 11SA. The principal surface 11SB is a plano-concave lens element having a concave surface. The optical element 12 is an infrared cut filter element, the optical element 13 is a biconvex lens element, and the optical element 14 is a protective glass element. The

optical elements

31 and 32 are optical stop elements, and the optical element 33 is a spacer element. That is, the optical element of the multilayer lens 10 includes not only the lens element but also the spacer element and the like.

The laminated lens 10 may further have an optical member. That is, the configuration of the multilayer lens is not limited to the configuration of the multilayer lens 10, and the configurations of the optical element, the spacer element, the optical diaphragm element, and the like are set in accordance with the specifications. The optical stop may be a film coated on one side of another optical element. The adhesive layer 20 is disposed between the plurality of optical elements.

The lens frame 40 is made of, for example, a metal such as stainless steel. The laminated lens 10 is accommodated in the through hole H <b> 40 of the lens frame 40. Although not shown, an adhesive is disposed in the gap between the multilayer lens 10 and the through hole H40, and the multilayer lens 10 is fixed to the lens frame 40.

In the optical unit 1, there is a frame-like step S10 on the outer periphery of the rectangular first main surface 11SA of the first optical element (optical element 11). As will be described later, the step portion S10 of the first main surface 11SA is produced by a molding method together with the concave surface of the second main surface 11SB.

On the other hand, in the through hole H40 of the lens frame 40, the front opening 40SA is smaller than the rear opening 40SB. In other words, at the front of the through hole H40, there is an extending portion (convex portion) C40 extending from the inner surface toward the optical axis.

The front opening 40SA of the lens frame 40 has substantially the same shape as the front surface 10SA (the first major surface 11SA of the multilayer lens 10), and the outer size is slightly larger than the front surface 10SA. The rear opening 40SB has substantially the same shape as the rear surface 10SB, and the outer size is slightly larger than the rear surface 10SB. Further, the length in the optical axis direction of the extended portion C40 of the lens frame 40, that is, the length of the side surface is substantially the same as the length of the side surface of the step portion S10. Furthermore, the length in the optical axis orthogonal direction of the extended portion C40 is substantially the same as the length of the bottom surface of the step portion S10.

For this reason, in the optical unit 1, the multilayer lens 10 inserted into the through hole H40 from the rear opening 40SB is fitted with the through hole H40. If at least the step portion S10 of the laminated lens 10 is engaged with the front opening 40SA of the lens frame 40, alignment of the lens frame 40 with the laminated lens 10 in the optical axis direction and positioning in the optical axis direction is easy. And the laminated lens 10 does not protrude from the front opening 40SA. Further, since the laminated lens 10 is accommodated in the lens frame 40, there is no risk of breakage during handling.

There is no problem if the length of the side of the extended portion C40 of the lens frame 40 is slightly shorter than the length of the side of the step S10, but if it is longer, foreign matter is likely to adhere to the outer periphery of the front surface 10SA. Unfavorable.

And since step part S10 is produced by the molding method so that it may mention later, unlike the step part produced by dicing method, there is no possibility that the optical characteristic by chipping may deteriorate. Further, the step portion S10 has higher dimensional accuracy than the step portion manufactured by the dicing method. For this reason, the precision of the optical axis alignment of the lens frame 40 and the multilayer lens 10 and the positioning in the optical axis direction are high.

As described above, the optical unit 1 disposed at the distal end portion 3A of the endoscope 9 has the front surface 10SA and the rear surface 10SB facing the front surface 10SA, and the first main surface 11SA which is the front surface 10SA The laminated lens 10 is inserted in the through hole H40 having the front opening 40SA and the rear opening 40SB, and the laminated lens 10 in which the plurality of optical elements 11 to 14 and 31 to 33 including the first optical element 11 are laminated There is a step S10 around the first main surface 11SA of the first optical element 11 manufactured by a molding method, and the front opening 40SA of the lens frame 40 has a step S10. Is fitted.

The side surface and the bottom surface of the step portion S10 manufactured by the molding method are smooth unlike the side surface 10SS which is a cut surface. However, it is not possible to find out from the structure or characteristics of the finished product that the step portion S10 has been produced by a molding method, and the structure or characteristics are analyzed based on measurement of surface roughness etc. Even, it is not possible to specify the manufacturing method.

The endoscope 9 having the laminated lens 10 has a small diameter, is easy to manufacture, and is excellent in optical characteristics.

<Method of Manufacturing Optical Unit>
Next, the method of manufacturing the optical unit will be described according to the flowchart shown in FIG. As described above, the laminated lens 10 is manufactured by a wafer level method in which the bonded wafer 10W (see FIG. 6) is cut and separated into pieces.

The

optical diaphragm wafers

31W and 32W (optical diaphragm elements 31 and 32) also have the function of a spacer.

<Step S11> Element Wafer Manufacturing Step A first element wafer 11W including a plurality of optical elements 11 is manufactured by a molding method. Each of the plurality of optical elements 11 has an optical axis.

For example, as shown in FIG. 5A, the resin sheet 11S is disposed between the two molds 11K1 and 11K2. Then, as shown in FIGS. 5B and 5C, the first element wafer 11W including the plurality of optical elements 11 is manufactured by the press molding method. The first element wafer 11W may be manufactured by an injection molding method or the like as long as it is a molding method in which the shape of a mold is transferred to a resin.

Then, on the outer periphery of the optical path region of the first main surface 11SA of the first element wafer 11W including the plurality of optical elements 11, a groove L10 wider than the cutting margin is formed.

In addition, an element wafer 12 W or the like including the optical element 12 is manufactured. The element wafers other than the first element wafer 11W may be manufactured by a method other than the molding method.

The first element wafer 11 W and the like are made of an optical resin such as polycarbonate which is transparent in the wavelength band of light of the specification. The first element wafer 11W or the like may be a hybrid element wafer or the like in which an optical path portion or the like made of resin is disposed on a parallel flat plate glass.

The element wafer 12W (see FIG. 6), which is a filter wafer, is a flat plate made of an infrared cut material that removes infrared rays (for example, light having a wavelength of 700 nm or more). The filter wafer may be a flat glass wafer or the like on which a band pass filter that transmits only light of a predetermined wavelength and cuts light of an unnecessary wavelength is disposed on the surface.

The parallel flat element wafer 14W (see FIG. 6) is a glass wafer or a transparent resin wafer.

<Step S12> Bonding Wafer Preparation Step As shown in FIG. 6, a plurality of element wafers 11W to 14W and 31W to 33W are stacked with the adhesive layer 20 interposed therebetween so that the optical axes O of the respective optical elements coincide. Thus, a bonded wafer 10W is produced.

For example, an adhesive material made of photosensitive epoxy resin, photosensitive polyimide or the like is applied to the element wafer, then solidified by hot plate drying at 120 ° C., and the adhesive layer 20 is provided by patterning by photolithography. Ru. As the adhesive layer 20, a film resist which is a photosensitive resin sheet may be used, or a liquid resin may be used. In the case of using a liquid resin, if a recess for containing an excess resin is formed around the optical path region, the liquid resin does not intrude into the optical path region.

The configuration of the plurality of element wafers, that is, the material, the shape, the number, the arrangement, the outer shape, and the like of the arranged optical elements are designed according to the specifications. However, it is preferable that the number of elements and the arrangement of elements included in a plurality of element wafers be the same.

<Step S13> Cutting Process In the optical unit manufacturing process, the bonded wafer 10W is cut, and a plurality of laminated lenses 10 are manufactured.

That is, as shown in FIG. 6, the bonded wafer 10W is cut by the dicing blade 50 whose cutting allowance is smaller than the width of the groove L10, and is separated into a plurality of laminated lenses 10 shown in FIG. It may cut using laser dicing or plasma dicing.

A laminated lens 10 in which a plurality of optical elements 11 to 14 and 31 to 33 are laminated has a front surface 10SA and a rear surface 10SB facing the front surface 10SA. The multilayer lens 10 includes a first optical element 11 having a first major surface 11SA which is a front surface 10SA. Then, there is a step portion S10 surrounding the optical path around the first main surface 11SA.

In addition, although the laminated lens 10 is a substantially rectangular parallelepiped, it is good also as a polygonal pillar or a cylinder by the process after separating into pieces. That is, the shape of the multilayer lens 10 is not limited to a substantially rectangular parallelepiped. Similarly, the "rectangle" in the present specification includes "a substantially rectangular shape" in which the corner is chamfered or curved.

<Step S14> Lens Frame Manufacturing Step A lens frame 40 having a through hole H40 is manufactured. The lens frame 40 is made of metal such as ceramic, Si, glass or stainless steel. The front opening 40SA of the lens frame 40 has an extending portion C40 which is a convex portion extended toward the optical axis, and the front opening 40SA is smaller than the rear opening 40S.

Further, the inner dimension of the rectangular rear opening 40SB in the direction orthogonal to the optical axis is slightly larger than the outer dimension of the rectangular rear surface 10SB of the multilayer lens 10. On the other hand, the inner dimension of the rectangular front opening 40SA in the direction orthogonal to the optical axis is slightly larger than the outer dimension of the rectangular front surface 10SA (11SA) of the multilayer lens 10.

The lens frame production process of step S14 may be performed before the optical unit production process of steps S11 to S13.

<Step S15> Assembling Step As shown in FIG. 8, the multilayer lens 10 is inserted into the through hole H40 from the rear opening 40SB of the lens frame 40 and fixed by an adhesive (not shown).

In addition, since the rear surface 10SB of the multilayer lens 10 is larger than the front opening 40SA of the lens frame 40, the multilayer lens 10 can not be inserted into the lens frame 40 from the front opening 40SA.

In the multilayer lens 10 inserted into the through hole H40 from the rear opening 40SB of the lens frame 40, the step portion S10 fits in the front opening 40SA of the lens frame 40. Therefore, the central axis of the lens frame 40 and the optical axis of the multilayer lens 10 are positioned, and at the same time, the position of the multilayer lens 10 in the optical axis direction with respect to the lens frame 40 is also positioned.

Since the groove L10 to be the step portion S10 transfers the shape of the mold 11K1, it is accurately formed at a predetermined position with an accurate shape. For this reason, the multilayer lens 10 is accurately positioned. Further, since no defect due to chipping occurs when forming the step portion S10, the optical unit 1 having the multilayer lens 10 has excellent optical characteristics. Further, since the step portion S10 is formed when the element wafer 11W is manufactured, the optical unit 1 is easy to manufacture.

<Modification of Embodiment>
The

optical units

1A and 1B, the manufacturing method of the

optical units

1A and 1B, and the

endoscopes

9A and 9B of the modification examples 1 and 2 of the embodiment are similar to the optical unit 1, the manufacturing method of the optical unit 1, and the endoscope 9 Since the same effect is obtained, the same reference numerals are given to the components having the same functions, and the description is omitted.

<Modification 1 of Embodiment>
As shown in FIG. 9, in the optical unit 1A of the first modification, the front opening 40SA of the through hole H40A of the lens frame 40A is circular. In addition, the first main surface 11SA (front surface 10SA) of the first optical element 11A surrounded by the step portion S10A is also circular.

When the stepped portion (notch) is formed in the first major surface 11SA of the first optical element by the two-step dicing method, the first major surface 11SA is limited to a rectangular shape. However, since the light path is circular, an unnecessary area is generated around the light path.

On the other hand, in the optical unit 1A, the first main surface 11SA of the first optical element 11A manufactured by the molding method is circular, there is no unnecessary area around the optical path, and the outer side in the optical axis orthogonal direction Small size and small diameter.

The shape of the first main surface 11SA of the optical unit manufactured by the molding method can be freely designed according to the shape of the front opening of the lens frame. For example, the shape of the first major surface 11SA may be hexagonal.

The endoscope 9A having the optical unit 1A has the effect of the endoscope 9 and further has the effect of the optical unit 1A so that the tip 3A has a small diameter.

<Modification 2 of Embodiment>
As shown in FIGS. 10 and 11, the imaging light collected by the optical unit 1B of the endoscope 9B of the modification 2 is received by the imaging unit 60 disposed on the rear surface 10SB of the optical unit 1B.

The imaging unit 60 includes a cover glass 72, an imaging element 71, and a stacked element 70 in which a plurality of

semiconductor elements

73, 74, and 75 are stacked. The laminated element 70 is a wafer level laminated body manufactured by cutting a bonded wafer in which a plurality of semiconductor wafers are laminated.

The imaging device 71 has a light receiving unit formed of a CCD or a CMOS imaging unit. The imaging device 71 may be any of a front side illumination type image sensor and a rear side illumination type image sensor. The stacked element 70 performs primary processing of an imaging signal output from the imaging element 71, and processes a control signal for controlling the imaging element 71. For example, the

semiconductor elements

73, 74, and 75 include an AD conversion circuit, a memory, a transmission output circuit, a filter circuit, a thin film capacitor, a thin film inductor, and the like. The number of elements included in the stacked element 70 is, for example, 3 or more and 10 or less, including the imaging element 71.

Note that the outer dimension in the optical axis orthogonal direction of the laminated element 70 is smaller than the outer dimension of the optical unit 1. A sealing resin 79 is filled between the laminated element 70 and the lens frame 40B. The sealing resin 79 may be the same resin as the adhesive fixing the optical unit 1 to the lens frame 40B. Further, the optical unit 1 and the laminated element 70 may be manufactured by a wafer level method by cutting a bonded wafer of the optical element wafer and the semiconductor element wafer.

In the imaging unit 60, the wiring board 61 is joined to the laminated element 70, and the signal cable 62 is joined to the wiring board 61.

Like the optical unit 1, the laminated element 70 manufactured by the wafer level method does not have high mechanical strength. However, the entire imaging unit 60 including the laminated element 70 is inserted into the lens frame 40 and protected.

The signal cable 62 may be joined to the imaging unit 60. When the imaging unit 60 joins the wiring board 61 or the signal cable 62 to the laminated element 70, there is no possibility that the laminated element 70 is damaged.

As shown in FIG. 10, the lens frame 40B is cylindrical. That is, the outer shape of the lens frame is not limited to a rectangular parallelepiped, and may be a cylinder or a polygonal prism. The front opening 40SA of the lens frame 40B has the same circular shape as the optical unit 1A, but may have the same rectangular shape as the optical unit 1.

As described above, the endoscope 9B has the optical unit 1B as an imaging optical system. In the endoscope which emits illumination light, the optical unit may constitute an illumination optical system. Further, the endoscope may have an illumination optical unit such as the optical unit 1 and an imaging optical unit.

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

DESCRIPTION OF

SYMBOLS

1, 1A, 1B ... Optical unit 3 ... Insertion part 3A ...

Tip part

9, 9A, 9B ... Endoscope 10 ... Laminated lens 10SA ... Front surface 10SB ... Rear surface 10SS ... Side surface 10W ... Bonded wafer 11 ... First

optical element

11, 12, 13, 14 ... Optical element 11K1, 11K2 ... Mold 11S ... Resin sheet 11SA ... First Second

main surfaces

11W, 12W, 13W, 14W ...

element wafers

12, 13, 14, 31, 32, 33 ... optical elements 20 ... adhesive layers 40 ... Lens frame 40SA: front opening 40SB: rear opening 50: dicing blade 60: imaging unit 61: wiring board 62: signal cable 70: lamination element 71: imaging element 72 · · ·

cover glass

73, 74, 5 ... semiconductor element 79 ... sealing resin

Claims

A method of manufacturing an optical unit disposed at a distal end portion of an endoscope, comprising:
Producing a plurality of element wafers including the respective optical elements;
Laminating the plurality of element wafers to produce a bonded wafer;
First optical system having a front surface and a rear surface facing the front surface, and having a first main surface which is the front surface and a second main surface facing the first main surface. Producing a laminated lens in which a plurality of optical elements including the element are laminated;
Manufacturing a lens frame having a through hole with a front opening and a rear opening;
Assembling the laminated lens from the rear opening into the through hole and fixing the laminated lens to the lens frame;
The first element wafer including the first optical element, which is produced in the step of producing the element wafer, is produced by a molding method.
There is a stepped portion around the first main surface of the first optical element,
A method of manufacturing an optical unit, wherein the step portion is fitted in the front opening of the lens frame in the assembling step.
The front opening and the rear opening of the lens frame are rectangular;
The method of manufacturing an optical unit according to claim 1, wherein the first main surface and the second main surface of the first optical element are rectangular.
The front opening of the lens frame is circular and the rear opening is rectangular;
The method of manufacturing an optical unit according to claim 1, wherein the first main surface of the first optical element is circular, and the second main surface is rectangular.
An optical unit manufactured by the method of manufacturing an optical unit according to any one of claims 1 to 3.
An optical unit disposed at a distal end portion of an endoscope, the optical unit comprising:
A laminated lens in which a plurality of optical elements including a front surface and a first optical element having a front surface and a rear surface facing the front surface and having a first main surface which is the front surface;
And a lens frame in which the laminated lens is inserted in a through hole having a front opening and a rear opening,
There is a stepped portion around the first main surface of the first optical element manufactured by a molding method,
An optical unit characterized in that the stepped portion is fitted to the front opening of the lens frame.
An endoscope comprising the optical unit according to claim 4 or 5.
It further comprises an imaging unit for receiving imaging light collected by the optical unit,
The endoscope according to claim 6, wherein the imaging unit is inserted into the lens frame.