JP2022139272A - Endoscope imaging device and endoscope - Google Patents

Abstract

To provide an endoscope imaging device and an endoscope high in reliability that can easily form an underfill layer.SOLUTION: An endoscope imaging device for acquiring an image of an observation object includes a lens barrel in which an imaging lens is provided, an image pick-up device that receives the light passing through the imaging lens, and subjects it to photoelectric conversion, a circuit board to which the image pick-up device is electrically connected through a bump having conductivity, and an underfill layer provided between the image pick-up device and the circuit board. The circuit board is bent, and has a bent part on the side opposite to the lens barrel. When a distance between a rear end on a bent part side of the circuit board of the image pick-up device and the bent part of the circuit board is represented as L1, and a distance between a front end on a lens barrel side of the image pick-up device and the front end on the lens barrel side of the circuit board is represented as L2, an inequality of L1<L2 is satisfied.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD The present invention relates to an endoscope imaging apparatus and an endoscope that acquire an image of an observation target.

2. Description of the Related Art In recent years, diagnosis using an endoscope system including an endoscope light source device, an endoscope (endoscope), and a processor has been widely performed.
It has an insertion section that is inserted into the body of the subject, and illumination light from the endoscope light source device is irradiated onto the observation target through the insertion section. 2. Description of the Related Art An endoscope uses an imaging device to capture an image of an observation target irradiated with illumination light to generate an image signal. The processor device processes the image signal generated by the endoscope to generate an observation image for display on the monitor. The imaging element is electrically connected to a signal cable via a flexible wiring board, and the signal cable is electrically connected to the processor device.

Since the physical burden on the subject is small, an endoscope is required to have a small insertion portion inserted into the body of the subject. Furthermore, endoscopes are required to be highly reliable because they are inserted into the body of a subject.
For example, the image pickup module of Patent Document 1 has an image pickup element, a chip size package in which a plurality of connection lands are arranged on the back side of a light receiving portion of the image pickup element, and a plurality of connection electrodes, the connection electrodes of which are provided on the chip. A circuit board and an underfill agent, comprising: a circuit board electrically and mechanically connected via connection lands and bumps of a size package; and an underfill agent filled in a gap between the chip size package and the circuit substrate. is sized to fit within the projection plane of the chip size package in the optical axis direction, and a notch opening at least to the connection surface is formed on the side surface of the circuit board perpendicular to the connection surface of the chip size package. .

Japanese Patent No. 6038424

In Patent Document 1 described above, a notch is provided for filling the underfill agent, but the underfill agent cannot always be supplied to a predetermined position.
SUMMARY OF THE INVENTION An object of the present invention is to provide an endoscope imaging apparatus and an endoscope that can easily form an underfill layer and have high reliability.

In order to achieve the above object, one aspect of the present invention is an endoscope imaging apparatus for acquiring an image of an observation target, comprising: a lens barrel having an imaging lens provided therein; an imaging element that receives light and photoelectrically converts it, a circuit board to which the imaging element is electrically connected via conductive bumps, and an underfill layer provided between the imaging element and the circuit board The circuit board is bent, and the circuit board has a bent portion on the opposite side of the lens barrel. L ₁ < L ₂ , where L ₁ is the distance between and L ₂ is the distance between the tip of the image sensor on the lens barrel side and the tip of the circuit board on the lens barrel side. It provides

At least one glass member arranged between the lens barrel and the imaging element, and a holding member connecting the glass member and the lens barrel, and the circuit board is a base portion of the holding member on the glass member side. The holding member has a flat surface on the portion facing the circuit board at the base on the glass member side, and the circuit board has a notch at the tip on the lens barrel side, and the notch is , preferably the plane of the holding member is exposed.
It is preferable that the circuit board has a concave portion on the surface to which the imaging device is connected, and the concave portion is provided at an end portion of the circuit board closer to the tip than the tip of the imaging device. It is preferable that a part of the concave portion is located below the imaging element.
It has an electronic component for driving the image pickup device, a signal cable electrically connected to the image pickup device, and a connecting member for holding the signal cable with respect to the holding member, and the electronic component and the signal cable are arranged on the circuit board. , the circuit board is preferably folded in a plurality of folding regions.
Moreover, one aspect of the present invention provides an endoscope having the endoscopic imaging device of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, an underfill layer can be easily formed and the endoscope imaging device and endoscope with high reliability can be provided.

It is a mimetic diagram showing an example of an endoscope system which has an endoscope of an embodiment of the present invention. 1 is a schematic perspective view showing a first example of an endoscope imaging device according to an embodiment of the present invention; FIG. 1 is a schematic perspective view showing a connecting member of a first example of an endoscope imaging device according to an embodiment of the present invention; FIG. 1 is a schematic side view showing a first example of an endoscope imaging device according to an embodiment of the present invention; FIG. 1 is a schematic diagram showing a holding member and a circuit board of a first example of an endoscope imaging device according to an embodiment of the present invention; FIG. 1 is a schematic diagram showing an imaging device and a concave portion of a circuit board of a first example of an endoscope imaging device according to an embodiment of the present invention; FIG. 1 is a schematic side view showing an example of a circuit board of a first example of an endoscope imaging device according to an embodiment of the present invention; FIG. FIG. 4 is a schematic side view showing another example of the circuit board of the first example of the endoscope imaging device according to the embodiment of the present invention; FIG. 4 is a schematic plan view showing another example of the circuit board of the first example of the endoscope imaging device according to the embodiment of the present invention; FIG. 4 is a schematic side view showing another example of the circuit board of the first example of the endoscope imaging device according to the embodiment of the present invention; FIG. 4 is a schematic perspective view showing a second example of an endoscope imaging device according to an embodiment of the present invention;

The endoscope imaging apparatus and endoscope of the present invention will be described in detail below based on preferred embodiments shown in the accompanying drawings.
It should be noted that the drawings described below are examples for explaining the present invention, and the present invention is not limited to the drawings shown below.
The terms orthogonal, parallel, etc. in the following description include the margin of error generally accepted in the relevant technical field. In addition, the numerical value of thermal conductivity includes the margin of error that is generally accepted in the relevant technical field.

[Endoscope system]
An endoscope system irradiates illumination light (not shown) to an observation site such as the body of a subject to be observed, captures an image of the observation site, and displays the observation site based on an image signal obtained by imaging. It generates an image and displays a display image.
FIG. 1 is a schematic diagram showing an example of an endoscope system having an endoscope according to an embodiment of the present invention.
The endoscope system 10 has an endoscope 12 , a light source device 14 and a processor device 16 . The endoscope system 10 has the same configuration as a general endoscope except for an endoscope imaging device (camera head) portion of the endoscope 12, which will be described later.

Endoscope 12 has an endoscopic imaging device. Although not shown in detail, the endoscope 12 has an insertion section to be inserted into the subject, an operation section connected to the insertion section, and a universal cord extending from the operation section. a curved portion connected to the distal end portion; and a flexible portion connecting the curved portion and the operating portion. The endoscope imaging device will be described later.

At the distal end of the endoscope 12, an endoscope imaging device 20 (Fig. 2 ) are provided. The bending section is configured to be bendable in a direction orthogonal to the longitudinal axis of the insertion section, and the bending operation of the bending section is operated by the operation section. Also, the flexible portion is configured to be relatively flexible so as to be deformable following the shape of the insertion path of the insertion portion.

The operation unit is provided with a button for operating the imaging operation of the endoscope imaging device 20 (see FIG. 2) at the distal end, a knob for operating the bending operation of the bending unit, or the like. In addition, the operating portion is provided with an introduction port into which a treatment tool such as an electric scalpel is introduced, and a treatment tool such as forceps is inserted into the insertion portion from the introduction port to the distal end. A fixture channel is provided.

A connector is provided at the end of the universal cord, and the endoscope 12 includes, via the connector, a light source device 14 that generates illumination light emitted from an illumination optical system at the distal end, and an endoscope imaging device at the distal end. 20 (see FIG. 2) is connected to a processor unit 16 for processing the video signals acquired.

The processor device 16 processes the input video signal to generate video data of the observation site, and displays the generated video data on a monitor (not shown) or records it in a storage medium such as a hard disk. Note that the processor device 16 may be configured by a processor such as a personal computer.

The light source device 14 captures an image of an observation target site in the body cavity with an endoscope imaging device 20 (see FIG. 2) of the endoscope 12, and emits red light (R), Illumination light such as white light or specific wavelength light composed of three primary colors such as green light (G) and blue light (B) is generated, supplied to the endoscope 12, and a light guide in the endoscope 12 and the like, and emitted from the illumination optical system at the distal end of the insertion portion of the endoscope 12 to illuminate the site to be observed within the body cavity.

A light guide or a group of electric wires (signal cables) are housed inside the insertion portion, the operation portion, and the universal cord. Illumination light generated by the light source device 14 is guided to the illumination optical system at the distal end via a light guide, and is also transmitted between the endoscope imaging device 20 (see FIG. 2) at the distal end and the processor device 16. At least one of signals and power is transmitted through the wires.

In addition, the endoscope system 10 may further include a water supply tank that stores wash water and the like, a suction pump that sucks aspirated substances (including the supplied wash water and the like) in the body cavity, and the like. Further, a supply pump or the like may be provided for supplying cleaning water in the water supply tank or gas such as external air to a conduit (not shown) in the endoscope.

[First example of endoscope imaging device]
FIG. 2 is a schematic perspective view showing the first example of the endoscopic imaging device according to the embodiment of the present invention, and FIG. 3 is a connecting member of the first example of the endoscopic imaging device according to the embodiment of the present invention. , and FIG. 4 is a schematic side view showing a first example of the endoscopic imaging apparatus according to the embodiment of the present invention. 4 shows a state in which the connecting member 30 of FIG. 3 is removed.
An endoscope imaging device 20 shown in FIG. 2 is mounted on the distal end portion of the endoscope 12 of the endoscope system 10 shown in FIG.
The endoscope imaging device 20 acquires an image of an object to be observed. For example, as shown in FIG. It has a circuit board 26 on which 36 , 36 a are arranged, and a connecting member 30 that holds a signal cable 28 against a holding member 24 . The imaging element 25 is electrically connected to the circuit board 26 via conductive bumps 42, as shown in FIG. It also has an underfill layer 44 provided between the imaging element 25 and the circuit board 26 . Also, the electronic components 36 and 36 a are electrically connected to the circuit board 26 .
The endoscope imaging apparatus 20 also has a holding member 24 and an engaging portion 32 that engages the connecting member 30 .

The signal cable 28 is electrically connected to the imaging element 25 , and the imaging element 25 is electrically connected to the processor unit 16 (see FIG. 1) via the circuit board 26 and the signal cable 28 . A signal cable 28 is arranged within the universal cord. Note that the configuration of the signal cable 28 is not particularly limited. For example, as shown in FIG. 4, the signal cable 28 is a multi-core cable in which a large number of signal lines 29 are bundled, a shield conductor is provided around the cable, and the cable is housed in a cylindrical jacket. A shield conductor of the signal cable 28 is called a shield 28a. For example, four signal lines 29 are provided. The number of signal lines is not particularly limited, and may be two, three, or five or more.

The lens barrel 22 is a cylindrical member, and an imaging lens 23 for imaging an observation target is provided inside. The configuration of the imaging lens 23 is not particularly limited, and may be a configuration having a plurality of lenses arranged side by side in the direction of the optical axis C, or a configuration having a single lens.
Here, as shown in FIGS. 2 and 4, the direction parallel to the optical axis C is defined as the X direction. Of the two directions perpendicular to the optical axis C, one is the Y direction and the other is the Z direction. The Y direction corresponds to the width direction of the endoscope imaging device 20 , and the Z direction corresponds to the height direction of the endoscope imaging device 20 .

The holding member 24 has a cylindrical attachment tube portion 24a fitted to the outer periphery of the lens barrel 22, and a base portion 24b that is integrally provided continuously with the attachment tube portion 24a. A prism 34 is provided on the rear surface 24e of the base 24b. The holding member 24 connects the glass member such as the prism 34 and the lens barrel 22 .
The prism 34 is, for example, a right-angle prism having an incident surface 34a and an exit surface 34b perpendicular to each other. The incident surface 34a is arranged to face the rear surface 24e of the base 24b. Thereby, the incident surface 34 a faces the imaging lens 23 .
A cover glass 33 is arranged on the imaging device 25 . A prism 34 is arranged on the cover glass 33, and the output surface 34b of the prism 34 and the imaging device 25 face each other.
The cover glass 33 protects the light receiving surface (not shown) of the imaging device 25 . The prism 34 guides the light that has passed through the imaging lens 23 to the light receiving surface of the imaging device 25 .

The imaging device 25 is provided, for example, on a surface 26a at one end of the circuit board 26 in parallel with the optical axis C of the imaging lens 23, and arranged below the base 24b of the holding member 24. As shown in FIG. On the back surface 26b of the circuit board 26 opposite to the light receiving surface of the image sensor 25, a plurality of connection terminals (not shown) for inputting/outputting signals or power to/from the image sensor 25 and the electronic components 36 and 36a are provided. ing.

The circuit board 26 is composed of, for example, a flexible board. A substrate having flexibility is, for example, a flexible wiring substrate. The circuit board 26 is, for example, bent at two points as shown in FIG. 4, and has a first curved portion 26c and a second curved portion 26d. Two electronic components 36, for example, are provided on the surface 26a of the circuit board 26 between the first curved portion 26c and the second curved portion 26d. For example, three electronic components 36 and two electronic components 36a are provided on the surface 26a of the circuit board 26 that is continuous with the second curved portion 26d.

By bending the circuit board 26 at two points and providing a first curved portion 26c and a second curved portion 26d, the size can be reduced in the X direction, and the endoscope imaging device 20 can be downsized in the X direction. can be done. That is, the endoscope imaging device 20 can be shortened. As shown in FIG. 4, a signal line 29 of a signal cable 28 is electrically connected to a connection terminal (not shown) provided on the back surface 26b of the other end of the circuit board 26. As shown in FIG.
The number of bends of the circuit board 26 is not limited to two.

The imaging device 25 receives light that has passed through the imaging lens 23 and photoelectrically converts the light. The imaging element 25 photoelectrically converts the optical image of the observation target to obtain an imaging signal. As described above, the imaging element 25 is electrically connected to the circuit board 26 via the conductive bumps 42, and the underfill layer 44 is filled between the imaging element 25 and the circuit board 26. ing.
The underfill layer 44 is formed using an underfill agent, and strengthens the connection between the imaging device 25 and the circuit board 26 . In addition, the underfill layer 44 relieves the stress generated in the junction between the image sensor 25 and the circuit board 26, for example, the bump 42, due to the difference in thermal expansion coefficient between the image sensor 25 and the circuit board 26. do. The underfill layer 44 firmly connects the imaging element 25 and the circuit board 26, increases the reliability of electrical connection, and provides the endoscope imaging apparatus 20 with high reliability.

The conductive bumps 42 are connected to electrodes provided on the connection surface of the imaging device 25 with the circuit board 26 . Bumps 42 are electrically connected to wiring layers of circuit board 26 .
The bumps 42 are made of metal or alloy. More specifically, the bumps 42 are made of solder. The bumps 42 formed of solder are also called solder balls. Note that the bumps 42 are not limited to solder or the like as long as they can electrically connect the imaging device 25 and the circuit board 26 . Also, the bumps 42 and the circuit board 26 may be directly electrically connected, or the bumps 42 and the circuit board 26 may be electrically connected via solder balls.

At least one glass member is arranged between the lens barrel 22 and the imaging element 25 in the endoscope imaging apparatus 20 . The at least one glass member is, for example, the cover glass 33 and the prism 34 described above, but the at least one glass member is not particularly limited to the cover glass 33 and the prism 34 described above.

The engaging portion 32 has at least one protrusion provided on the holding member 24 and a recess provided on the connecting member 30 that engages with the protrusion of the holding member 24 . At the engaging portion 32 , the holding member 24 and the connecting member 30 can be firmly fixed by engaging the convex portion of the holding member 24 and the concave portion of the connecting member 30 . In addition, the concave portion of the connecting member 30 also includes a penetrating opening portion, which will be described later.

The base 24b of the holding member 24 shown in FIGS. 2 and 4 is provided with two protrusions 24c facing each other with the prism 34 interposed therebetween. The two convex portions 24c cover a part of the side surface 34c of the prism 34, and the prism 34 is sandwiched between the two convex portions 24c to be fixed. The two projections 24c have the same shape and size, and the projections 24c are provided on both sides of the base 24b of the holding member 24. As shown in FIG. A side surface 34c of the prism 34 is a surface orthogonal to the entrance surface 34a and the exit surface 34b.
In the holding member 24, the convex portion 24c (see FIGS. 2 and 4) of the base portion 24b has, for example, a rectangular outer shape, but one corner is notched. Therefore, the convex portion 24c (see FIGS. 2 and 4) of the base portion 24b is substantially pentagonal.

The connecting member 30 holds the signal cable 28 with respect to the holding member 24 .
For example, as shown in FIG. 3, the connecting member 30 has a flat plate-like bottom portion 40f formed by bending one plate material, and a holding portion 40a having a flat plate-like base portion 40g continuous with the bottom portion 40f. . In the connecting member 30, the holding portion 40a side is the proximal end 41a. When the base portion 40 g is crimped so as to press the signal cable 28 , the base portion 40 g is bent along the outer skin of the signal cable 28 .
Arm portions 40b are provided on flat plate-like substrate portions 40g that face each other across an opening in the holding portion 40a. The connecting member 30 has a pair of arm portions 40b. The arm portion 40b is bent outward from the holding portion 40a at the proximal end 41a side, and then extends linearly. For this reason, the pair of arm portions 40b has a wider distance between the distal ends 41b than the proximal ends 41a, and this distance is appropriately determined according to the protrusions 24c of the holding member 24 shown in FIG. An opening 40c is provided at the tip 41b of each arm 40b.

The opening 40c of the arm portion 40b engages with the convex portion 24c of the holding member 24. As shown in FIG. The opening 40c is formed, for example, by cutting a part of the arm 40b into a rectangular shape.
The opening 40c may have the same size and shape as the external shape of the projection 24c. Here, the aforementioned shape of the opening 40c having the same size and shape as the external shape of the protrusion 24c includes an error range that is generally allowed in the relevant technical field. For this reason, the opening 40c and the protrusion 24c may be any of so-called clearance fit, intermediate fit, and interference fit.
It should be noted that, in the following description as well, "same size and shape" includes the error range that is generally allowed in the relevant technical field as described above.

As described above, due to the configuration having the engaging portion 32 that engages the opening 40c of the pair of arm portions 40b and the convex portion 24c of the holding member 24, the convex portion fits into the concave portion, so that endoscopic imaging is possible. The length of the device 20 in the Y direction orthogonal to the optical axis C can be shortened, and an increase in the size of the endoscope imaging device 20 can be suppressed. Moreover, strong fixation between the holding member 24 and the connecting member 30 can be achieved.
By matching the thickness of the arm portion 40b with the height of the convex portion 24c, when the opening portions 40c of the pair of arm portions 40b are engaged with the convex portions 24c of the holding member 24, respectively, the endoscopic image pickup apparatus The length in the Y direction orthogonal to the optical axis C of 20 can be made shorter, and with this configuration, the endoscope imaging device 20 can be made more compact.

In the connecting member 30, the pair of arm portions 40b are preferably bent so that the distal ends 41b of the arm portions 40b are closer to each other than the proximal ends 41a of the arm portions 40b. That is, it is preferable that the pair of arm portions 40b be bent in the closing direction. Accordingly, by spreading the arm portion 40b once, the opening 40c of the arm portion 40b can be fitted into the convex portion 24c of the holding member 24, thereby facilitating assembly.
As described above, the pair of arm portions 40b is preferably bent so that the distal ends 41b of the arm portions 40b are closer to each other than the proximal ends 41a of the arm portions 40b, but this is the state of the parts before assembly. good too.
Also, although the opening 40c is provided in the arm portion 40b, the present invention is not limited to this.
The connecting member 30 is held with the signal cable 28 attached to the inner side 40e of the holding portion 40a. The method of attaching the signal cable 28 is not particularly limited as long as the signal cable 28 does not come off from the holding portion 40a and the signal line 29 does not come off when the endoscope is used. It is attached to the connecting member 30 using an adhesive.

In addition, in the holding member 24, the two projections 24c have the same size and shape as described above, that is, are congruent, but may have different sizes and shapes.
In addition, in the holding member 24, the shape of the convex portion is not particularly limited to the quadrangle described above. It may be a finished shape. Furthermore, it is not limited to one shape, but may be a plurality of same shapes arranged or a specific pattern.
In the engaging portion 32, one convex portion and one concave portion are engaged at one portion, but the engaging portion is not limited to one, and one convex portion is engaged with a plurality of portions. A configuration having a part may be used.

It should be noted that the size of the convex portion of the holding member 24 is preferably, for example, a size that covers at least a portion of the side surface 34c of the prism 34 . By setting the size of the convex portion to cover at least a part of the side surface 34c of the prism 34, the prism 34 can be held and fixed more stably, and when assembled, the prism 34 can be attached to the holding member. can be used to position the prism in the Y direction.
The upper limit of the size of the convex portion of the holding member 24 can be a size that covers the entire side surface 34 c of the prism 34 .
Furthermore, by providing two convex portions 24c in the holding member 24 so as to face each other, the prism 34 and the circuit board 26 are surrounded by the arm portions 40b. Thereby, the engagement between the holding member 24 and the connecting member 30 is stabilized, and the prism 34 and the circuit board 26 can be protected.
Although the holding member 24 is configured to have two projections 24c, the present invention is not limited to this as long as the size is not increased, and three or more projections may be provided. That is, the number of engaging portions can be three or more.

The prism 34 guides the light from the imaging lens 23 to the imaging device 25, and is not limited to a rectangular prism. Note that the prism 34 is not necessarily required depending on the arrangement position of the imaging device 25 .

As the imaging element 25, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor can be used. For example, by using the prism 34 that bends the optical axis C of the imaging lens 23 at a right angle, the degree of freedom of the arrangement position of the imaging device 25 can be increased, and the size of the base 24b of the holding member 24 is not limited. A large imaging device 25 can be used.
After the holding member 24 and the prism 34 are adhesively fixed, they are sandwiched by the arm portion 40b from the side surface, and the arm portion 40b, the holding member 24 and the prism 34 are connected by adhesion. Bonding between the holding member 24 and the prism 34 is also strengthened by adhering the arm portion 40b from the side surface. Further, by bonding not only the side surface of the holding member 24 but also the side surface 34c of the prism 34 and the arm portion 40b, the fixing strength of the arm portion 40b is increased.
The connection strength between the holding member 24 and the arm portion 40b is determined by the fact that the convex portion 24c and the opening portion 40c (concave portion) have the same shape and the same size, and that the forces in the X and Z directions are applied to the cross section of the arm portion. , the mechanical strength of the endoscope imaging device 20 is increased.

FIG. 5 is a schematic diagram showing a holding member and a circuit board of the first example of the endoscopic imaging device according to the embodiment of the present invention, and FIG. 2 is a schematic diagram showing an imaging device and a concave portion of a circuit board in Example 1. FIG. 5 and 6, the same components as those of the endoscope imaging apparatus 20 shown in FIGS. 2 to 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the endoscope imaging apparatus 20, as shown in FIG. 4, the distance between the rear end 25b of the imaging device 25 on the bent portion 26e _side of the circuit board 26 and the bent portion 26e of the circuit board 26 is defined as L1. . The distance between the tip 25a of the imaging element 25 on the lens barrel 22 side and the tip 26f of the circuit board 26 on the lens barrel 22 _side is L2. At this time, L ₁ <L ₂ . By setting L ₁ <L ₂ in the circuit board 26 , the circuit board 26 can be mounted without increasing the length of the circuit board 26 below the imaging element 25 , that is, without increasing the size of the endoscope imaging apparatus 20 . An underfill agent (not shown) that forms the underfill layer 44 can be easily injected between the imaging device 25 and the circuit board 26 from the tip 26 f side of the tip 26 . Thereby, the underfill layer 44 can be easily formed between the imaging device 25 and the circuit board 26 .
Note that L1 is, for example, 0.35 _mm , and L2 is, for example, 0.7 _mm .

The underfill layer 44 is obtained by curing the underfill agent. However, the underfill layer 44 may contain an uncured underfill agent.
The underfill agent that constitutes the underfill layer 44 is not particularly limited. A resin that is used as a sealing resin between is appropriately usable. For example, a one-liquid heat-curable epoxy resin is used as the underfill agent. In this case, after supplying the underfill agent, the underfill layer 44 is formed by heating and holding at a predetermined temperature.
Although L ₁ <L ₂ , L ₁ is preferably as short as possible. As a result, the length of the circuit board 26 below the imaging device ₂₅ can be made longer without increasing the length of the circuit board 26 . That is, it is preferable because the endoscope imaging apparatus 20 can be miniaturized, the underfill agent can be easily injected, and the underfill layer 44 can be formed more easily.

The bent portion 26e is the end on the side of the first curved portion 26c, and is the beginning of the bending of the first curved portion 26c of the circuit board 26. As shown in FIG.
A cross-sectional image of the circuit board 26 is obtained by imaging the endoscope imaging device 20 using X-rays. In the cross-sectional image of the circuit board 26, the bending start position of the first curved portion 26c of the circuit board 26 can be identified, and the above-described bent portion 26e can be identified.
The bending start position is the connection position between the first curved portion 26 c and the circuit board 26 below the imaging device 25 . For this reason, it is possible to specify the connection position described above by specifying the first curved portion 26c and assuming that the circuit board 26 is flat.

FIG. 5 shows the endoscope imaging device 20 viewed from the rear surface 26b side of the circuit board 26. As shown in FIG.
As shown in FIG. 5, the circuit board 26 is arranged below the base portion 24b on the glass member side of the holding member 24, that is, below the base portion 24b on the prism 34 side. The holding member 24 has a flat surface 24f at a portion facing the circuit board 26 at the base portion 24b on the glass member side, that is, on the prism 34 side. The circuit board 26 has a notch 26h at the tip on the lens barrel 22 side. The notch 26h is formed from the Y-direction end of the circuit board 26 so as to leave the tip 26f of the circuit board 26, line-symmetrically with respect to the X-direction. The notch 26h has an arcuate corner on the center side of the circuit board 26 in the Y direction.
When viewed from the back surface 26 b side of the circuit board 26 , the notch 26 h exposes the flat surface 24 f of the holding member 24 . For example, the flat surface 24f of the base portion 24b of the holding member 24 is in contact with other members to restrict the rotation of the imaging device 20 for endoscopes. By exposing the flat surface 24f, it becomes easier to restrict the rotation.
Note that the shape of the notch portion 26h is not particularly limited to the arc-shaped corner portion shown in FIG. 5 as long as the flat surface 24f can be exposed.

Further, as shown in FIG. 6, the circuit board 26 has a concave portion 46 on the surface 26a to which the imaging device 25 is connected. It is preferably provided in the portion 26g. Further, for example, the entire area of the recess 46 is arranged at the end portion 26g closer to the tip 26f of the circuit board 26 than the tip 25a of the imaging element 25 is.
The recess 46 holds an underfill agent for forming the underfill layer 44 . The recessed portion 46 serves as a reservoir of the underfill agent, and the underfill agent does not flow out from the circuit board 26.例文帳に追加The concave portion 46 allows the underfill agent to be efficiently supplied between the imaging device 25 and the circuit board 26 .
After the underfill agent is supplied to the concave portion 46, the underfill agent is supplied between the imaging element 25 and the circuit board 26 by capillary action. Thereafter, for example, the underfill agent is held at a temperature corresponding to the underfill agent, and the underfill agent is cured to form the underfill layer 44 . By providing the concave portion 46 , it becomes easier to supply the underfill agent between the imaging element 25 and the circuit board 26 .

A part of the concave portion 46 is more preferably positioned below the imaging device 25 . That is, it is preferable that a part of the concave portion 46 is hidden under the imaging device 25 . Since a part of the recess 46 is positioned below the imaging element 25, when the underfill agent is supplied to the recess 46, the underfill agent is more easily supplied between the imaging element 25 and the circuit board 26. be able to.
If the recess 46 is entirely below the imaging device 25 , it is difficult to supply the underfill agent to the recess 46 . It is preferably arranged on the 26f side.
The recess 46 is formed by pressing the surface 26a of the circuit board 26 and physically recessing it. Also, a recess 46 is formed by removing part of the surface 26a of the circuit board 26 . If the surface 26a of the circuit board 26 is composed of a resist layer (not shown), the recesses 46 are formed by removing the resist layer in the regions where the recesses 46 are to be formed. The concave portion 46 has, for example, a circular shape when viewed from the surface 26a of the circuit board 26 as shown in FIG.
The concave portion 46 preferably has a circular shape when viewed from the surface 26a side of the circuit board 26, and preferably has a diameter of 0.5 mm and a depth of 0.02 mm. If the size of the concave portion 46 is 0.5 mm in diameter and 0.02 mm in depth, the underfill agent can be easily placed between the imaging device 25 and the circuit board 26 after the underfill agent is supplied to the concave portion 46 . can supply.
The size of recess 46 can be measured using an optical microscope or a laser microscope. Also, the shape of the concave portion 46 can be specified using an optical microscope or a laser microscope.

<Example of circuit board>
Next, the circuit board 26 will be explained.
FIG. 7 is a schematic side view showing an example of the circuit board of the first example of the endoscopic imaging device according to the embodiment of the present invention. The circuit board 26 shown in FIG. 7 shows a state before being bent into the form shown in FIG. 2, and shows a state in which the circuit board 26 is unfolded.
For example, as shown in FIG. 7, the circuit board 26 has an image sensor 25 and electronic components 36 arranged at predetermined positions on a surface 26a. A signal line 29 of the signal cable 28 is electrically connected to a connection terminal (not shown) provided on the rear surface 26b. When the circuit board 26 is unfolded, that is, when it is in a state before being bent, the signal cable 28 extends on the side opposite to where the imaging device 25 is arranged. This configuration improves workability in electrically connecting the signal cable 28 to the circuit board 26 by soldering or the like, and also improves assembly workability.

In FIG. 7, for example, the imaging device 25 and two electronic components 36 are provided on the surface 26a of the circuit board 26 with a first bending region 27a therebetween. are provided with a second bending region 27b therebetween. The first bending region 27a corresponds to the first curved portion 26c, and the second bending region 27b corresponds to the second curved portion 26d.
In the circuit board 26, the first bending area 27a is bent so that the imaging element 25 and the electronic component 36 face each other, and the second bending area 27b is bent so that the back surface 26b of the circuit board 26 faces each other. As a result, the circuit board 26 is configured to have a first curved portion 26c and a second curved portion 26d, as shown in FIG. When bending the first bending region 27a, it is bent based on the _first bending surface Lb1. When bending the second bending region 27b, it bends based on the _second bending surface Lb2. Thus, the circuit board 26 is folded at multiple folding regions. In FIG. 7, the _first bent surface Lb1 and the _second bent surface Lb2 are parallel, but are not limited to this and may not be parallel. Since the _first bent surface Lb1 is provided in the first bent area 27a and the _second bent surface Lb2 is provided in the second bent area 27b, the _first bent surface Lb1 and the second bent surface Lb1 It does not _intersect perpendicularly with the bent surface Lb2.
It is preferable that all the circuit boards 26 are bent in the same direction. As a result, there is no bending region in the Y direction of the endoscope imaging device 20 like the first bending portion 26c and the second bending portion 26d, and there is a bending region in the space inside the endoscope imaging device 20. You can reduce the proportion of

Although the imaging device 25 and the electronic components 36 and 36a are provided on the surface 26a of the circuit board 26, the present invention is not limited to this, and the imaging device 25 and the electronic components 36 and 36a are provided on separate surfaces. may be provided.
Moreover, it is preferable to provide the imaging device 25 and the electronic components 36 and 36a on one circuit board 26 as shown in FIG. By providing them on one circuit board 26, the number of parts can be reduced.
The electronic components 36 and 36a are for driving the imaging device 25, and although not particularly limited, include voltage regulators, resistors, and capacitors, for example. A voltage regulator is a device that stabilizes the voltage to the imaging element 25 and outputs a constant voltage to the imaging element 25 .
In the circuit board 26, for example, at the other end, the rear surface 26b of the circuit board 26 and the shield 28a of the signal cable 28 may be joined by soldering, for example. By joining the shield 28a of the signal cable 28 to the rear surface 26b, the heat generated from the imaging element 25 and the electronic components 36 can be discharged from the circuit board 26 to the outside of the endoscope imaging apparatus 20 via the signal cable 28. It is possible to improve the heat dissipation of the endoscope imaging device 20 .

<Other examples of circuit boards>
FIG. 8 is a schematic side view showing another example of the circuit board of the first example of the endoscopic imaging device according to the embodiment of the present invention, and FIG. FIG. 10 is a schematic plan view showing another example of the circuit board of the first example, and FIG. 10 is a schematic plan view showing another example of the circuit board of the first example of the endoscope imaging device according to the embodiment of the present invention; It is a side view. 8 to 10, the same components as those of the endoscope imaging device 20 shown in FIGS. 2 to 5 and the circuit board 26 shown in FIG. do.
FIG. 8 shows a state in which the circuit board 26 is folded at two points as in FIG. 4, and an underfill layer 44 is formed.
9 and 10 show the state before the circuit board 26 is folded, and show the state in which the circuit board 26 is unfolded. As with the circuit board 26 shown in FIG. 7, the circuit board 26 shown in FIG. 10 is bent based on the _first bending surface Lb1 when bending the first bending region 27a. When bending the second bending region 27b, it bends based on the _second bending surface Lb2.

As shown in FIG. 8, the circuit board 26 is bent at the first bending region 27a and the second bending region 27b in the same manner as in FIG. However, if it cannot be bent with a predetermined radius of curvature, for example, the circuit board 26 near the first curved portion 26c and near the second curved portion 36d will not be flat. In this case, the connection state of the electronic component 36b in the vicinity of the first curved portion 26c and the electronic component 36c in the vicinity of the second curved portion 26d are affected. There is also

As shown in FIGS. 9 and 10, in the circuit board 26, a thin portion 48 is provided in the first bent region 27a, and a thin portion 49 is provided in the second bent region 27b. By providing the above-described thin portions 48 and 49 on the circuit board 26, the first bending region 27a and the second bending region 27b are easily bent, and the first bending portion 26c and the second bending portion 26d are A predetermined radius of curvature can be obtained more reliably. As a result, the connection state of the electronic components 36b and 36c near the first curved portion 26c and the electronic component 36c near the second curved portion 26d are not affected, and the connection state of the electronic components 36b and 36c is improved. can be done.
The thin portions 48 and 49 described above are formed, for example, by thinning the circuit board 26 itself. More specifically, for example, if the circuit board 26 has a ground layer, the thin portions 48 and 49 are formed by removing the resist layer formed on the ground layer.
The sizes of the thin portions 48 and 49 are appropriately determined according to the sizes of the first bending region 27a and the second bending region 27b, respectively. The thin portion 48 may be formed in the entire area or a part of the first bending area 27a. The end of the thin portion 48 may be aligned with the bent portion 26e.
Also, the thin portion 49 may be formed in the entire area or a part of the second bending area 27b. The edge of the thin portion 49 may be aligned with the edge of the bent portion.

[Second example of endoscope imaging device]
The endoscope imaging device 20 is not limited to the configuration shown in FIG. A second example of the endoscope imaging apparatus will be described below.
FIG. 11 is a schematic perspective view showing a second example of the endoscopic imaging device according to the embodiment of the present invention. 11, the same components as those of the endoscope imaging apparatus 20 shown in FIGS. 2 and 4 and the connecting member 30 shown in FIG. 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The endoscopic imaging device 20a shown in FIG. 11 differs from the endoscopic imaging device 20 shown in FIG. It has the same configuration as the mirror imaging device 20 .
The endoscope imaging device 20a has a cover 50 that covers the electronic components 36, 36a. The cover 50 is preferably made of metal, for example. By providing the metal cover 50, the heat generated by the electronic components 36, 36a can be conducted to the cover 50, and the heat generated by the electronic components 36, 36a can be exhausted to the outside of the endoscope imaging device 20a. .
The cover 50 is made of stainless steel, copper alloy, graphite, or the like, for example.
Moreover, it is preferable that the cover 50 is joined to the connecting member 30 or that the cover 50 and the connecting member 30 are integrally constructed. As a result, the number of members through which the heat generated by the electronic components 36 and 36a is conducted increases, so that the heat that may be conducted to the imaging device 25 can be further reduced, and the heat can be efficiently discharged to the outside of the endoscope imaging device 20. can be heated.
Note that when the cover 50 and the connecting member 30 are integrally constructed, the cover 50 and the connecting member 30 are made of the same metal.
Also, the cover 50 and the connecting member 30 may be configured separately. In this case, the cover 50 preferably holds the arm portions 40b of the connecting member 30 so that the distal ends 41b are closer to each other than the proximal ends 41a. As a result, the opening 40c of the arm portion 40b and the convex portion 24c of the holding member 24 are less likely to come off, and the holding member 24 and the connecting member 30 are more securely fixed. becomes higher.

The present invention is basically configured as described above. Although the endoscopic imaging apparatus and endoscope of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the scope of the present invention. Of course you can.

REFERENCE SIGNS LIST 10 endoscope system 12 endoscope 14 light source device 16 processor device 20, 20a endoscope imaging device 22 lens barrel 23 imaging lens 24 holding member 24a mounting cylinder portion 24b base portion 24c convex portion 24e rear surface 24f plane 25 imaging element 25a , 26f front end 25b rear end 26 circuit board 26a front surface 26b rear surface 26c first curved portion 26d second curved portion 26e bent portion 26g end portion 26h notch portion 27a first bent region 27b second bent region 28 signal cable 28a Shield 29 Signal Line 30 Connecting Member 32 Engagement Part 33 Cover Glass 34 Prism 34a Entrance Surface 34b Output Surface 34c Sides 36, 36a Electronic Component 40a Holding Part 40b Arm 40c Opening 40e Inside 40f Bottom 40g Base 41a Base 41b tip 42 bump 44 underfill layer 46 recess 48, 49 thin portion 50 cover C optical axis Lb ₁ first bent surface Lb ₂ second bent surface

Claims (6)

An endoscope imaging device for acquiring an image of an observation target,
a lens barrel in which an imaging lens is provided;
an imaging device that receives light that has passed through the imaging lens and performs photoelectric conversion;
a circuit board to which the imaging element is electrically connected via conductive bumps;
An underfill layer provided between the imaging element and the circuit board,
the circuit board is bent, and the circuit board has a bent portion on the opposite side of the lens barrel;
The distance between the rear end of the circuit board of the imaging device on the side of the bent portion and the bent portion of the circuit board is set to L1, and the tip of the imaging device on the _side of the lens barrel and the circuit board , wherein L ₁ <L ₂ , where L ₂ is the distance from the tip of the lens barrel side. at least one glass member disposed between the lens barrel and the imaging element;
a holding member that connects the glass member and the lens barrel,
The circuit board is arranged below a base portion of the holding member on the glass member side,
the holding member has a flat surface in a portion facing the circuit board in the base portion on the glass member side;
2. The endoscopic imaging apparatus according to claim 1, wherein said circuit board has a notch at said tip on said lens barrel side, and said notch exposes said flat surface of said holding member. The circuit board has a concave portion on the surface to which the imaging element is connected,
3. The endoscopic imaging apparatus according to claim 1, wherein said recess is provided at an end portion of said circuit board closer to said tip than said tip of said imaging device. 4. The endoscopic imaging apparatus according to claim 3, wherein a portion of said recess is located below said imaging device. an electronic component that drives the imaging element;
a signal cable electrically connected to the imaging element;
a connecting member for holding the signal cable with respect to the holding member;
the electronic component and the signal cable are arranged on the circuit board;
The endoscopic imaging device according to any one of claims 2 to 4, wherein said circuit board is bent at a plurality of bending regions. An endoscope having the endoscopic imaging device according to any one of claims 1 to 5.

Images