JP2002253486A - Method of soldering optical member of endoscope and metallic frame, soldered structure and endoscope having this soldered structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soldered structure of an optical member of an endoscope and a metallic frame which is capable of surely sealing the inside of an optical system to the outside and is capable of assuring a good visual field in spite of repetition of autoclave sterilization. SOLUTION: The soldered structure of the optical member 14 disposed on the endoscope and deposited with a metallic film on at least its outer peripheral surface and the metallic frame 15 for holding the optical member 14 is formed with a brazing filler metal engaging groove S into which a brazing filler metal 19 prior to melting used for soldering can be fitted between the optical member 14 and the metallic frame 15 in the state of combining both.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for soldering an optical member and a metal frame in an endoscope, and an endoscope having this structure.

[0002]

2. Description of the Related Art Endoscopes are currently used in various fields in the medical and industrial fields. In particular, in the medical field, in recent years, multifunctional endoscopes that can be inserted into a body cavity to observe a deep part in the body cavity or perform a medical treatment using a treatment tool as necessary have been widely used. Is being used. Such medical endoscopes must be disinfected and sterilized each time they are used in order to prevent infectious diseases and the like.

As a method for sterilizing an endoscope, recently, autoclave sterilization (high-pressure steam sterilization) which can be used immediately after sterilization without complicated work and has low running cost is used.
Is becoming mainstream. The autoclave sterilization method is a method in which steam of high temperature (about 120 ° C. to 135 ° C.) is infiltrated into an object to be sterilized under high pressure, and sterilization is performed. It is necessary to prevent water vapor from entering the optical system of the mirror. In particular, the joining between the optical member and the metal member holding the optical member must be performed so as to obtain sufficient sealing performance and durability. In this sense, it is difficult to say that a resin-based adhesive that has been conventionally used for the above-described joining easily permeates water vapor, and thus a seal structure suitable for autoclave sterilization can be obtained.

For this reason, Japanese Patent Application Laid-Open No. 8-122601 discloses a technique for hermetically joining a structure of an optical system and an optical member with low-melting glass. In addition, Japanese Unexamined Patent Publication No.
Japanese Patent No. 209898 discloses a technique in which a stainless steel member for a stainless steel insertion portion is plated with gold for soldering, and an optical member and the stainless steel member for a stainless steel insertion portion are soldered. Japanese Patent Application Laid-Open No. 6-82724 discloses a structure in which a frame and an optical member are fixed to each other by soldering or using low-melting glass. A technique of filling with solder and fixing by heating has been disclosed.

[0005]

However, as disclosed in Japanese Patent Application Laid-Open No. 8-122601, even when the structure of the optical system and the optical member are hermetically bonded with low-melting glass, autoclave sterilization is repeated. If it is performed, the low melting point glass may be deteriorated and airtightness may not be secured. In this case, water vapor may enter the optical system, causing fogging inside the optical system, or deteriorating the optical member to cause poor visual field.

On the other hand, in the technique disclosed in Japanese Patent Application Laid-Open No. 6-209898, a specific method of soldering is not shown, and skill is required when heating with a conventional soldering iron. .

Further, in the technique disclosed in Japanese Patent Application Laid-Open No. 6-82724, the work of setting a spherical solder in a groove is complicated, and it is difficult to perform stable soldering.

The present invention has been made in view of the above circumstances, and an object thereof is to reliably seal the inside of an optical system to the outside, and to secure a good visual field even after repeated autoclave sterilization. An object of the present invention is to provide a method of soldering an optical member of an endoscope to a metal frame, a soldering structure, and an endoscope provided with the structure, which are easy to perform.

[0009]

According to one aspect of the present invention, there is provided an optical member provided on an endoscope and having a metal film formed on at least an outer peripheral surface thereof.
In a method of soldering a metal frame holding the optical member, the optical member and the metal frame are used for soldering in a brazing material engaging groove formed between the metal member and the metal member in a combined state. Fitting the brazing material before melting, heating the optical member and the metal frame together with the brazing material in the fitted state to melt the brazing material, thereby soldering the optical member and the metal frame. It is characterized by.

According to a second aspect of the present invention, there is provided a soldering structure of an optical member provided on an endoscope and having a metal film formed on at least an outer peripheral surface thereof, and a metal frame holding the optical member. In the above, in a state where the optical member and the metal frame are combined, a brazing material engaging groove into which a brazing material before melting used for soldering can be fitted is formed therebetween. It is characterized by.

According to a third aspect of the present invention, there is provided an optical system having an optical member having a metal film formed on at least an outer peripheral surface thereof, and a metal frame for holding the optical member. In the endoscope in which the metal member and the metal member are hermetically joined by soldering, the unfused brazing material used for soldering is fitted between the optical member and the metal frame. A brazing material engaging groove is formed.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 6 show a first embodiment of the present invention. FIG. 1 shows a medical or industrial endoscope. As shown in the figure, the endoscope main body 1 includes an insertion portion 2 to be inserted into a body, for example. The insertion section 2 has a distal end 3 into which an optical system is incorporated, and a bending section 4 that is operated to bend. An operation section 5 is provided at a base end of the insertion section 2, and an angle lever 6 for remotely operating the bending section 4 is provided on the operation section 5.

A flexible cord 8 is connected to the operation unit 5, and a connector 7 is provided at an end of the flexible cord 8, which is detachably connected to a light source device (not shown). The connector 7 is provided with a base 9 that can communicate with the internal space of the endoscope main body 1. The endoscope body 1 has a watertight structure, and the base 9 can communicate with the internal space of the endoscope body 1 by attaching an adapter (not shown). The base 9 may have a check valve structure that communicates with the internal space of the endoscope main body 1 when the pressure in the internal space of the endoscope main body 1 becomes higher than the external pressure by a predetermined amount or more. good. In this case, it is not necessary to use an adapter.

FIG. 2 shows a cross section of the imaging unit 10 assembled inside the distal end portion 3. In the figure, reference numeral 11 denotes a solid-state imaging device. On the front surface of the solid-state imaging device 11,
A cover glass 12 as an optical member is adhered and fixed. Further, a metal coating such as chromium, nickel, or gold is formed on the outer peripheral side surface 12a of the cover glass 12. The cover glass 12 is made of sapphire,
It is soldered (soft brazed) to a metal frame 13 formed of stainless steel in an airtight and watertight manner (hereinafter referred to as “in a sealed state”).

A cover glass 14 as an optical member exposed on the outer surface of the endoscope main body 1 is provided on the distal end side of the imaging unit 10. On the outer peripheral side surface 14a of the cover glass 14, a metal film such as chromium, nickel, and gold is formed. The cover glass 14 is made of sapphire and is soldered (soft brazed) to a metal frame 15 made of stainless steel in a sealed state.

A lens frame C supporting a plurality of lenses L between the cover glasses 12 and 14 is held by an insulating member 16. The insulating member 16 is formed of, for example, an electric insulating material such as ceramics. In addition, both ends 16a and 16b of the insulating member 16 are metallized (metal film).

The insulating member 16 includes a metal frame 17 and a metal frame 18.
Are fitted. Each of the metal frames 17 and 18 is soldered (soft brazed) to the end surfaces 16a and 16b of the insulating member 16 in a sealed state. The metal frame 13 and the metal frame 18 and the metal frame 15 and the metal frame 17 are respectively joined in a sealed state by welding. Therefore, the space between the cover glass 12 and the cover glass 14 is completely sealed from the outside by the above soldering and welding.

FIG. 3 is a sectional view showing a state before the cover glass 14 and the metal frame 15 are joined together.
4 shows a soldering structure between the metal frame 4 and the metal frame 15. As shown, the metal frame 15 is made of a first jig 2 made of a heat-resistant material such as carbon, PTFE, or alumina.
5 and assembled. Specifically, the metal frame 15 is fitted to the outer periphery of the cylindrical portion 25a in a state where the step 15b formed on the inner surface of the distal end portion is applied to the end surface of the cylindrical portion 25a of the jig 25. . Also, the metal frame 15
Has a cover glass 14 dropped therein. Specifically, the cover glass 14 is fitted and positioned in the distal end portion of the metal frame 15 with the peripheral edge of the rear surface 14b abutting against the abutting surface 15a of the metal frame 15.
At this time, the surface side of the cover glass 14 forms a groove-shaped gap (a brazing material engaging groove) S with which a metal ring 19 described later can be engaged with the tapered surface 15 d at the tip of the metal frame 15. Protrudes from the tip of the metal frame 15 by a predetermined amount. That is, the abutting surface 15a of the metal frame 15
From the surface of the cover glass 14 is defined,
Thereby, a gap S where the metal ring 19 is engaged is formed between the tapered surface 15d of the metal frame 15 and the outer peripheral side surface 14a of the cover glass 14.

A second jig 26 is fitted on the outer peripheral surface of the distal end portion of the metal frame 15. The jig 26 can support the metal ring 19 engaging with the gap S between the metal frame 15 and the cover glass 14 from the outside, and can also support the metal frame 1.
5 protrudes from the tip of the metal frame 15 by a predetermined amount so that the wax does not flow out to the outer peripheral portion. In this case, the amount of protrusion of the jig 26 from the tip of the metal frame 15 is defined by a step 15 c formed on the outer peripheral surface of the metal frame 15. It is desirable that the gap between the metal frame 15 and the jig 26 is small.
For example, if the metal frame 15 and the jig 26 are tightened and fitted using an elastic body having heat resistance such as fluoro rubber, a gap between the metal frame 15 and the jig 26 can be eliminated. The jig 26 is formed of a material having no wettability to the brazing material.

The fitting portion of the metal frame 15 with the cover glass 14, the tapered surface 15d, and the tip surface 15e are plated with good solder wettability (nickel plating, gold plating, etc.).
Is given.

In this manner, the cover glass 14 is dropped into the metal frame 15, and the jigs 25 and 2 are respectively placed on these.
After assembling, as shown in FIG.
Specifically, in the gap S between the tapered surface 15d of the metal frame 15 and the outer peripheral side surface 14a of the portion of the cover glass 14 protruding from the metal frame 15, the metal ring 1
9 is placed in the engaged state. In this case, the metal ring 19
Is held from the outside by the second jig 26,
It does not fall out of the gap S.

The metal ring 19 is made of a solder material such as a gold-tin alloy and has a circular cross-sectional shape. Further, the diameter of the metal ring 19 is such that the metal ring 19 has a tapered surface 15 d of the metal frame 15 and the chamfered portion 7 of the outer peripheral side surface 14 a of the cover glass 14 provided with the metal film.
The size is set to be in contact with 0.

The assembled body in the state shown in FIG. 3 in which the metal ring 19 is set in the gap S between the metal frame 15 and the cover glass 14 is then put into a hydrogen furnace (not shown), and at a predetermined temperature for a predetermined time. Heated. Thereby, the metal ring 19 is melted. At this time, the metal surface is activated in a hydrogen furnace atmosphere, and since the metal ring 19 is in contact with the outer peripheral side surface 14a of the cover glass 14 and the surface of the plated metal frame 15, the molten metal ring 19 It can flow with wettability to the outer peripheral side surface 14 a of the cover glass 14 and the surface of the plated metal frame 15. On the other hand, since the metal ring 19 has no wettability to the jig 26, the jig 26 is not soldered to the metal frame 15. Further, since the jig 26 is fastened and fitted to the outer periphery of the metal frame 15, the solder does not flow out to the outer periphery of the metal frame 15.

The melting temperature of the metal ring 19 is 400
It is desirable that the temperature is not more than the degree. If the melting temperature is 1000 ° C. or higher, the cover glass 14 may be broken by the stress from the metal frame 15 when cooled after soldering due to the difference in the coefficient of thermal expansion between the metal frame 15 and the cover glass 14.

FIG. 4 is a sectional view showing a state after the metal frame 15 and the cover glass 14 are soldered. The metal ring 19 is completely melted, enters the fitting portion between the metal frame 15 and the cover glass 14 and is fixed. The volume of the metal ring 19 is the same as the metal frame 15 and the cover glass 14.
And their chamfers are filled. The same soldering is performed between the cover glass 12 and the metal frame 1.

As described above, in the present embodiment, the cover glass 12 as an optical member provided on the endoscope main body 1 and having a metal film formed on at least the outer peripheral surface thereof is provided.
14 and metal frame 1 for holding cover glasses 12 and 14
The cover glass 12 and the solid-state imaging device 11 are bonded together, and the insulating member 16, the metal frame 17, and the metal frame 18 are sealed. Soldered in
Metal frame 13 and metal frame 18 and metal frame 15 and metal frame 17
Are joined in a sealed state by welding. Therefore, the cover glass 12 and the cover glass 14
Can completely seal the space between the outside and the outside, preventing the invasion of water vapor into the optical system even after repeated autoclave sterilization.
A good visual field can be maintained by preventing the adhesive from deteriorating and peeling.

In this embodiment, as shown in FIG. 3, the metal ring 19 is easily provided in the gap S between the tip end face 15d of the metal frame 15 and the portion of the cover glass 14 protruding from the metal frame 15. Since it can be mounted, and soldering can be performed simply by mounting and putting it into the hydrogen furnace in this way, skill is not required for work, and stable quality can always be ensured. Therefore, suitable for mass production,
You can also lower the price. Further, since the setting of the metal ring 19 is easy, the metal frame 1
Even if the parts 3 and 15 and the cover glasses 12 and 14 are very small parts, they can be handled well and the processing time can be shortened.

In this embodiment, for example, a metal foil or a paste of the same material can be used instead of the metal ring 19. Further, even when soldering (soft brazing) by heating in a vacuum atmosphere or an inert gas atmosphere without using a hydrogen furnace, the same operation and effect (such as the antireflection film does not deteriorate) can be obtained. it can. In this embodiment, since the metal frames 13 and 15 are made of stainless steel, the melting point of the metal ring 19 is set to 400 ° C. or less.
If it is made of a material (cobal, tungsten, amber, etc.) similar to the coefficient of thermal expansion of No. 4, a similar technique using a metal ring of a hard solder having a high melting point (eg, gold braze, silver braze, silver alloy, etc.) Can be used (40
The cover glass will not be damaged even if the bonding is performed at a melting temperature of 0 ° C. or more).

The metal ring 19 is not limited to a circular cross section, but may be of various shapes depending on the situation. For example, as shown in FIG. 5, a metal ring 20 having a triangular cross section along the tapered shape of the tapered surface 15d of the metal frame 15 can be used. In this case, the metal ring 20 can be attached so that the tapered surface 15d of the metal frame 15 and the outer peripheral side surface 14a of the cover glass 14 on which the metal film is formed are in contact with almost no gap.

As shown in FIG. 6, a metal ring 21 having a wedge-shaped lower side and a pentagonal cross section can also be used. In this case, the metal ring 21 has two tapered surfaces forming a pentagon and the tapered surface 15 d of the metal frame 15.
And the chamfered portion 70 of the outer peripheral side surface 14 a of the cover glass 14. In this case, FIG.
As shown in FIG. 3, the metal ring 21 in contact with the tapered surface 15 d of the metal frame 15 and the chamfer 70 of the cover glass 14.
From the intersection of the two tapered surfaces to the thin portion 21a
May be extended. By doing so, the thin portion 22a can be inserted into the gap between the metal frame 15 and the cover glass 14. According to this method, the metal frame 1 having a small thickness at the joint with the cover glass 14 and having a large chamfer cannot be obtained.
5 is useful for the design.

FIGS. 8 and 9 show a second embodiment of the present invention. Note that, in this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 8, the cover glass 14
Are fitted to the metal frame 15 and are positioned so as to abut against the end face of the abutting portion 24 projecting from the abutting surface 15a of the metal frame 15. Therefore, an annular groove 25 is formed on the outer peripheral portion of the butting portion 24 of the metal frame 15. Further, the metal ring 19 has a circular cross section, and is provided in the gap S so as to be in contact with the tapered surface 15d of the metal frame 15 and the chamfered portion 70 of the outer peripheral side surface 14a of the cover glass 14 provided with the metal film. Are located.

FIG. 8 shows a state after the metal frame 15 and the cover glass 14 have been brazed by the metal ring 19. As shown in the figure, a fillet is formed on the outer peripheral portion of the groove 25, and the brazing material does not flow into the abutting portion 24.

As described above, according to the present embodiment, the same operation and effect as those of the first embodiment can be obtained, and since the groove 25 is formed in the metal frame 15, the brazing material is melted. Sometimes, the brazing material does not flow between the abutting portion 24 of the metal frame 15 and the cover glass 14. Thus, the cover glass 14 does not float due to the flow of the brazing material, and the cover glass 14 does not tilt with respect to the metal frame 15. Therefore, no image defect occurs.

According to the technical contents described above, various configurations as described below can be obtained.

1. In an endoscope having at least an optical member having a metal film formed on an outer peripheral surface thereof and a metal frame for holding the optical member, the brazing material is a ring in the endoscope in which the optical member and the metal member are hermetically joined by brazing. An endoscope device having a shape, wherein a brazing material installation groove is provided in a part of a brazing portion.

2. 2. The endoscope apparatus according to claim 1, wherein the brazing material installation groove is formed by chamfering a metal frame.

3. The endoscope apparatus according to claim 1, wherein the brazing material installation groove is formed by chamfering an optical member.

4. The endoscope apparatus according to claim 1, wherein the brazing is performed in a hydrogen atmosphere or a non-oxidizing atmosphere.

5. 2. The endoscope apparatus according to claim 1, wherein a soft brazing material or a hard brazing material is used.

[0042]

As described above, according to the present invention,
Provides a soldering structure between an optical member of an endoscope and a metal frame that can securely seal the inside of the optical system to the outside and ensure a good field of view even after repeated autoclave sterilization. can do.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an endoscope according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of an imaging unit provided in the endoscope of FIG.

FIG. 3A is a cross-sectional view showing a state before soldering a cover glass and a metal frame constituting the imaging unit in FIG. 2;
(B) is a principal part enlarged view of (a).

FIG. 4 is a cross-sectional view showing a state after soldering a cover glass and a metal frame constituting the imaging unit of FIG. 2;

FIG. 5 is a sectional view showing a state before soldering a cover glass including a metal ring and a metal frame according to a first modification;

FIG. 6 is a cross-sectional view showing a state before soldering a cover glass including a metal ring and a metal frame according to a second modified example.

FIG. 7A is a cross-sectional view showing a state before soldering a cover glass including a metal ring and a metal frame according to a third modified example, and FIG. 7B is an enlarged view of a main part of FIG. .

FIG. 8 is a cross-sectional view showing a state before soldering a cover glass and a metal frame constituting the imaging unit of FIG. 2 according to the second embodiment of the present invention.

9 is a cross-sectional view illustrating a state after soldering a cover glass and a metal frame constituting the imaging unit of FIG. 2 according to the second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Endoscope main body 12, 14 ... Cover glass (optical member) 13, 15 ... Metal frame 19 ... Metal ring S ... Gap (brazing material engagement groove)

Claims (3)

[Claims] 1. A method of soldering an optical member provided on an endoscope and having a metal film formed on at least an outer peripheral surface thereof, and a metal frame holding the optical member, wherein the optical member and the metal frame are soldered. In the brazing material engaging groove formed between them in a state where they are combined with each other, a ring-shaped brazing material before melting used for soldering is fitted, and in the fitted state, the optical member and the metal frame are Is heated together with the brazing material to melt the brazing material, whereby the optical member and the metal frame are soldered. 2. A soldering structure of an optical member provided on an endoscope and having a metal film formed on at least an outer peripheral surface thereof, and a metal frame holding the optical member, wherein the optical member, the metal frame, A brazing material engaging groove, into which a ring-shaped brazing material before melting used for soldering can be fitted, is formed therebetween. . 3. An optical system having an optical member having a metal film formed on at least an outer peripheral surface thereof and a metal frame for holding the optical member, wherein the optical member and the metal member are hermetically sealed by soldering. In the joined endoscope, a brazing material engaging groove into which a ring-shaped brazing material before melting used for soldering can be fitted between the optical member and the metal frame. An endoscope, characterized in that an endoscope is formed.