JP2002051268A - Image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup device, with which focusing can be easily attained into no control by decreasing the number of components and reducing errors in production. SOLUTION: In the image pickup device provided with an image pickup element 1 for converting a formed optical image to an electric signal, a substrate 3A where the image pickup element 1 is flip chip mounted onto the lower surface and an optical image pickup system 2 for forming the optical image on the image pickup element 1, the optical image pickup system 2 is provided by integrally molding a lens 2a formed from a transparent member and a supporting means 2b formed from a member, which holds the lens 2, not to transmit light. In this case, integral molding is based on insert molding. Thus, the number of components can be decreased. Further, an error to affect the focusing performance of the image pickup device can be reduced by integral molding. Besides, by applying an adhesive agent 4 around the bonding part of the optical image pickup system 2 and the substrate 3A, the optical image pickup system 2 can be adhered to the substrate 3A while eliminating the thickness error of the adhesive agent 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CCD (Charge)
More particularly, the present invention relates to a small-sized image pickup apparatus in which an image pickup optical system and an image pickup element are integrated.

[0002]

2. Description of the Related Art FIG. 16 is a sectional view showing a conventional structure of an image pickup apparatus in which an image pickup optical system and an image pickup device are integrated.
In FIG. 16, reference numeral 20 denotes a lens, reference numeral 21 denotes a lens barrel holding the lens 20, reference numeral 21a denotes a threaded portion of the lens barrel 21, reference numeral 22 denotes a diaphragm on the rear surface of the lens 20, and reference numeral 23 denotes a lens that holds the lens barrel 21. Reference numeral 23a denotes a screw portion of the lens holder 23 and reference numeral 24a.
Is an infrared cut filter, 25 is an image sensor, 2
5a is an effective pixel area which is an area where incident light can be sensed in the image sensor 25, 25b is a bonding wire,
Reference numeral 25c indicates a lead, and reference numeral 26 indicates a substrate.

[0003] When manufacturing such an imaging device, various variations are likely to occur. Variations that occur during manufacturing include the following. Variation in mounting of the lens 20 and the lens barrel 21, variation in back focus due to variation in the shape of the lens 20, variation in the shape of the lens barrel 21, variation in the thickness of the infrared cut filter 24, variation in the shape of the lens holder 23, effective in the image sensor 25. This includes variations in the position of the pixel region 25a in the optical axis direction, variations in the attachment of the imaging element 25 to the substrate 26, and the like.

[0004] Because of these variations, an error occurs in the distance between the lens 20 and the imaging device 25, and the focusing performance of the manufactured imaging device differs for each product, and the focusing performance is not stabilized. Therefore, in the conventional imaging device shown in FIG. 16, the screw portion 21 a of the lens barrel 21 and the screw portion 23 a of the lens holder 23 are fitted, and the screw portion 21 a is rotated to move the lens barrel 21 up and down. The adjustment was performed so that the optical system was focused.

However, in such a conventional imaging apparatus, the number of parts is large, and at the time of mass production, one lens barrel 21 is mounted on the lens holder 23 to adjust the degree of focusing (hereinafter referred to as focus adjustment). There was a problem that had to be done.

FIG. 17 shows an example of an imaging apparatus in which focus adjustment can be omitted by increasing the mounting accuracy of each component. Note that the imaging apparatus shown in FIG.
This is a technique described in JP-A-48-48.

In FIG. 17, reference numeral 30 denotes an aperture plate, reference numeral 30a denotes an incident hole (aperture hole), reference numeral 31 denotes a filter, reference numeral 32 denotes a support member, reference numeral 32a denotes a positioning portion for the aperture plate,
Reference numeral 32b is a positioning portion for a lens, reference numeral 32c is a positioning portion for an imaging device, reference numeral 32d is a concave portion, reference numeral 33 is a lens, reference numeral 34 is an infrared cut filter, reference numeral 35 is an imaging device, and reference numeral 35a is an imaging device 35. Effective pixel area,
Reference numeral 35b is a bonding wire, reference numeral 36 is a lead,
Reference numeral 37 denotes an adhesive. Note that Japanese Patent Application Laid-Open No. 9-23254
Although the filter 31 is an infrared cut filter in the description of Japanese Patent Publication No. 8, placing an infrared cut filter in front of the lens 33 in a small-sized imaging device is likely to cause flare. Therefore, in FIG. 17, the infrared cut filter 34 is disposed after the lens 33.

According to this technique, in order to increase the mounting accuracy of each component, the positioning portion 3
2b is provided on the support member 32 to enhance the mounting accuracy of the lens 33. In addition, a positioning portion 32c is provided for the image sensor 35 to enhance the mounting accuracy of the image sensor 35. Further, the portion into which the adhesive 37 is injected is formed as a recess 32d.
In this way, the image pickup device 35 is prevented from being lifted by the adhesive 37. In addition, the focus adjustment mechanism of the lens 33 is omitted by increasing the mounting accuracy of each component, and the lens barrel 21 and the lens holder 23 of FIG. 16 are integrated as a support member 32 to reduce the number of components. ing.

[0009]

The problem to be solved by the present invention is disclosed in Japanese Patent Application Laid-Open No. Hei 9-232.
FIG. 18 shows an error considered to affect the focusing performance in the imaging device described in Japanese Patent Application Publication No. 548. First, there is a back focus error due to a shape error of the lens 33, and this error is represented by ΔG. Next, the distance error in air conversion due to the thickness error of the infrared cut filter 34 is ΔB
And Further, in order to reduce the size of the imaging device, the chip itself which is cut out of a semiconductor wafer without using a ceramic package or the like is used for the imaging device 35, and therefore, there is a thickness error of the wafer. Therefore, the thickness error of the wafer of the imaging device 35 is set to ΔC. The thickness error of the adhesive layer 40 between the lens 33 and the support member 32 is represented by ΔH, and the shape error of the support member 32 is represented by ΔJ.

Since all of these errors affect the focusing performance, the following conditions must be satisfied in order to realize an image pickup apparatus with the above-described configuration and without focus adjustment. That is, assuming that the error of the depth of focus allowed as the focusing performance is Δδ, the sum of the previous errors (ΔG + Δ
B + ΔC + ΔH + ΔJ) must be smaller than the value of the error Δδ. If the sum of the errors (ΔG + ΔB + ΔC
If (+ ΔH + ΔJ) is not smaller than the error Δδ, the object to be imaged will not be in focus and the image will be out of focus (out of focus).

[0011] Therefore, there is a problem that it is necessary to accurately manage the above-mentioned variation, and high accuracy is required for management and assembly of each member.

Japanese Patent Application Laid-Open No. 9-232548 describes that the support member 32 of the optical member and the lead 36 are integrally formed. Usually, the support member 32 is often formed of a synthetic resin such as acrylic, PC (polycarbonate), ABS (acrylonitrile-butadiene-styrene copolymer), PBT (polybutylene terephthalate), and the like, while the lead 36 is It is generally formed of a highly conductive metal. Therefore, the members such as the support member 32 and the lead 36 often have significantly different characteristics such as the coefficient of thermal expansion.

It is technically difficult to integrally mold both members having significantly different characteristics. Usually, the portion of the support member 32 below and above the lead 36 is often formed separately. Then, the upper and lower support members 32 formed in such a manner will be bonded later. In this case, a thickness error ΔK of the adhesive layer 39 between the upper and lower support members also occurs, which also causes deterioration of the focusing performance, and therefore, there has been a problem that higher accuracy is required.

That is, the above problems can be summarized as follows. In the conventional imaging apparatus, it is necessary to perform focus adjustment for each product at the time of mass production of the imaging apparatus. Further, there is a problem that the number of components of the imaging apparatus increases because the focus adjustment is performed.

In order to eliminate the need for focus adjustment,
There is a problem that the molding accuracy of the component parts is increased, and that high accuracy is required for assembling each member.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image pickup apparatus in which the number of constituent parts is reduced, and an error at the time of manufacturing is reduced so that focus adjustment can be easily performed.

[0017]

According to the first aspect of the present invention, there is provided an image pickup device for converting a formed optical image into an electric signal,
A substrate that holds the image sensor, held by the substrate,
An imaging optical system that forms the optical image on the imaging element, wherein the imaging optical system holds a lens portion formed of a transparent material and the lens portion, and is formed of a light-shielding material. An imaging device comprising a support member formed, wherein the lens unit and the support member are integrally formed.

According to a second aspect of the present invention, in the imaging apparatus according to the first aspect, the support member is formed by injecting the light-shielding material into a first mold, and The support member formed by the mold is inserted into a second mold, and thereafter, the lens portion and the lens portion are formed by insert molding in which the transparent material is injected into the second mold to form a lens portion. This is an imaging device in which a support member is integrally formed.

According to a third aspect of the present invention, in the imaging device according to the first aspect, the imaging element includes an effective pixel area, which is an area capable of sensing incident light of the optical image, on a main surface thereof. The substrate has an opening, a first main surface, and a second main surface opposite to the first main surface, and the substrate is provided in the effective pixel region of the imaging device through the opening. The incident light arrives, the main surface of the imaging device is adhered to the second main surface while exposing the effective pixel region to the opening, and the support member of the imaging optical system is configured to be the first member. Is an imaging device held on the main surface of the camera.

The invention according to claim 4 is the imaging device according to claim 1, wherein the substrate has a main surface, the support member of the imaging optical system has a bottom surface and side surfaces, The bottom surface of the support member is applied to the main surface of the substrate, and the side surface of the support member and a portion of the main surface of the substrate not covered by the bottom surface of the support member are bonded by an adhesive. Is an imaging device to be used.

According to a fifth aspect of the present invention, there is provided the imaging apparatus according to the fourth aspect, wherein the adhesive has a light shielding property.

The invention according to claim 6 is the imaging device according to claim 4, wherein the adhesive is a UV curing agent.

According to a seventh aspect of the present invention, there is provided the imaging apparatus according to the first aspect, further comprising an infrared cut filter, wherein the infrared cut filter is provided outside the imaging optical system. This is an imaging device arranged on the incident side.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <Embodiment 1> In this embodiment, a lens in an image pickup optical system and a supporting member are integrally molded to reduce the number of components and to achieve non-adjustment of focus. This realizes an imaging device that is easy to plan.

FIG. 1 is a sectional view showing an imaging apparatus according to the present embodiment. As shown in FIG. 1, the imaging device according to the present embodiment includes a CCD sensor and a CMOS (Complementarity).
an image sensor 1 such as a sensor, a substrate 3A having a part of the upper surface of the image sensor 1 bonded via an adhesive layer 6, and an infrared cut filter 5 bonded to the substrate 3A with an adhesive or the like. And the adhesive 4 on the substrate 3A.
And an imaging optical system 2 held by the camera.

FIG. 2 is an enlarged view of a joint between the image pickup device 1 and the substrate 3A. The imaging device 1 uses, for example, a chip cut out of a semiconductor wafer without encapsulation in a package. In FIG. 2, an effective pixel region 1a for converting a light image of a subject formed by the imaging optical system 2 into an electric signal and an electrode 1b for extracting a signal from the effective pixel region 1a are formed on an upper surface thereof. I have.

On the other hand, as the substrate 3A, for example, a flexible substrate capable of realizing a thin substrate is used. The flexible substrate refers to a two-layer polyimide substrate or the like in which the thickness of the substrate is thin and thin and can be bent, and a wiring pattern is formed in the substrate thin film. Such a flexible substrate is often used when manufacturing a small and thin imaging device.

FIG. 3 is a bottom view of the substrate 3A. Substrate 3A
A circuit pattern 3c through which an electric signal flows is provided on the lower surface (on the side where the image sensor 1 is adhered), and an electrode 3b connected to the electrode 1b of the image sensor 1 is provided at one end of the circuit pattern 3c. Have been. The other end of the circuit pattern 3c is provided with an electrode 3a for outputting an electric signal from the image sensor 1 to the outside. By connecting another device to the electrode 3a, signals can be exchanged between the imaging device and the other device. Note that an opening 3d is provided in the center of the substrate 3A, and incident light reaches the effective pixel area 1a of the imaging device 1 through the opening 3d.

Then, the electrode 1b of the image sensor 1 and the substrate 3A
Is bonded by a conductive bonding layer 6 such as a solder bump, so that the upper surface of the imaging device 1 is bonded to the lower surface of the substrate 3A. This is a so-called flip-chip mounting.

Next, the imaging optical system 2 will be described. The imaging optical system 2 is formed of a material that allows light to pass through, and a lens unit 2a that forms a subject image on the effective pixel area 1a of the imaging device 1; a lens unit 2a that is formed of a material that does not allow light to pass therethrough; And a supporting member 2b for holding the same.

Hereinafter, a method of forming the imaging optical system 2 will be described. In the present invention, in order to integrally mold the support member 2b and the lens portion 2a, first, the support member 2b is injection-molded, and then the lens portion 2a is formed by insert molding.

A first mold 7 for injection-molding a support member 2b other than the lens portion 2a of the image pickup optical system 2 is mounted on the first mold 7 in FIG.
6 to FIG. 4 and 5 are side views of the first mold 7, and FIG. 6 is a perspective view of the first mold 7. Note that the viewing direction differs between FIG. 4 and FIG. 5 by 90 degrees.

As shown in FIGS. 4 and 5, the first mold 7 is divided into upper and lower molds 7a and 7b. In addition,
The position where the upper and lower parts are split is an example, and is not limited to the positions shown in FIGS. 4 and 5.

The first mold 7 further includes a mold member 7c for forming an injection portion 2c on the support member 2b during injection molding. The lower mold 7
b has a concave portion 7d for fitting the mold member 7c and a gate portion 7e for injecting the material of the support member 2b. 4 to 6, the mold member 7c is shown in a columnar shape, and the gate portion 7e is shown in a prismatic shape. However, these shapes are merely examples, and are not limited to the above shapes.

The support member 2b is formed as follows. First, the upper and lower molds 7a and 7b are fitted together with the mold member 7c fitted in the recess 7d. Next, the material of the support member 2b is injected from the gate portion 7e, and injection molding is performed. here,
Examples of the material of the support member 2b include PC (polycarbonate), ABS (acrylonitrile-butadiene-styrene copolymer), and PBT (polybutylene terephthalate).
What is necessary is just to employ | adopt synthetic resins, such as. It is to be noted that a black synthetic resin may be used, and light may be shielded so that incident light from portions other than the lens portion 2a does not reach the effective pixel region 1a.

Then, by pulling out the mold member 7c after the injection molding, the support member 2b having the injection portion 2c is provided.
Is molded. FIG. 7 shows the support member 2b formed by injection molding. It can be seen from FIG. 7 that an injection portion 2c is formed on the support member 2b. In this injection part 2c, a hole is penetrated from the outer surface to the inner surface of the support member 2b.

Next, FIGS. 8 and 9 show a second mold 8 for integrally molding the lens portion 2a with the support member 2b. 8 and 9 are side views of the second mold 8.
Note that the viewing direction differs between FIG. 8 and FIG. 9 by 90 degrees.

As shown in FIGS. 8 and 9, the second mold 8 is also divided into two upper and lower molds 8a and 8b. In addition,
The position of dividing vertically is only an example, and is not limited to the positions shown in FIGS. 8 and 9. The lower mold 8b is provided with a gate portion 8c for injecting the material of the lens portion 2a when performing insert molding.

The formation of the lens portion 2a is performed as follows. First, as shown in FIG. 10, the support member 2b of FIG. 7 is fitted into the lower mold 8b, and the upper and lower molds 8a and 8b are fitted.
At this time, the positions of the injection portion 2c of the support member 2b and the gate portion 8c of the lower mold 8b are adjusted so as to conduct. In addition, the gate unit 8c and the injection unit 2
c and the first and second molds 7,
8 is designed.

Next, a valve 9 for injection molding is inserted into the gate portion 8c of the second mold 8 from the outside, and the material of the lens portion 2a is injected through the valve 9 to perform insert molding. Here, the material of the lens portion 2a is, for example, P
A transparent material such as an acrylic resin such as MMA (polymethyl methacrylate) may be used. In addition, P
C (polycarbonate) or the like may be used. Specific product names of such transparent materials include "ARTON" and "ZEONEX".

The injected transparent material passes through the gate portion 8c, flows into the space other than the portion occupied by the support member 2b in the second mold 8 via the injection portion 2c, and the lens portion 2c.
a is formed.

By such insert molding, the support member 2b formed of a light shielding material and the lens portion 2a formed of a transparent material can be integrally formed. By performing the integral molding, it is possible to form the imaging optical system 2 that does not cause an error in adhesion between the lens portion 2a and the support member 2b, as described later.

When molding an optical member such as the lens portion 2a, the molding should be performed by low-speed injection in order to avoid traces of flowing transparent material (flow marks) and burning (jetting). Is common. On the other hand, for other members, high-speed injection molding, which requires a relatively short time, is often performed in order to increase mass production efficiency. Also in the present invention, the lens portion 2a may be formed by low-speed injection, and the support member 2b may be formed by high-speed injection. By using the insert molding as described above, two members having different injection speed conditions can be integrally molded. If insert molding is used, it is also possible to integrally mold an imaging optical system in which members having different colors, such as the lens portion 2a and the support member 2b, and members having different characteristics such as the coefficient of thermal expansion are combined.

In this embodiment, the shape of the lens portion 2a is a concave portion on the incident side and a convex portion on the exit side.
It goes without saying that both the entrance side and the exit side may be constituted by convex lenses having convex portions.

Now, the imaging optical system 2 integrally formed as described above is mounted on the substrate 3A so that the optical image generated by the imaging optical system 2 is formed on the effective pixel area 1a of the imaging device 1.
Placed on top. Specifically, the bottom surface of the support member 2b is applied to the top surface of the substrate 3A, and the side surface of the support member 2b and the portion of the top surface of the substrate 3A that are not covered by the bottom surface of the support member 2B are bonded by the adhesive 4. As a result, the imaging optical system 2 is fixed to the substrate 3A. As a result, no adhesive layer is formed between the support member 2b and the substrate 3A, and ΔK in FIG.
Can eliminate the thickness error of the adhesive layer.

The adhesive 4 is made of, for example, black.
An adhesive having a light-shielding property may be used. that way,
Even if there is a slight gap between the support member 2b and the substrate 3A, light does not enter the imaging optical system 2 from there.

As the adhesive 4, a UV (Ultra Violet ray) curing agent which is cured by ultraviolet rays may be used.
In the case of bonding using a resin or the like, since the resin is melted and applied around the joint between the imaging optical system 2 and the substrate 3A,
The high-temperature resin adheres to the imaging optical system 2. Therefore, the imaging optical system 2 may be deformed by heat.
If a UV curing agent is used, bonding can be performed at a low temperature, and the problem of deformation does not occur. Further, since the shrinkage of the material itself during curing is small, displacement between the imaging optical system 2 and the substrate 3A hardly occurs. Further, since the UV curing agent has a small heat shrinkage after curing and is excellent in heat resistance, if an UV curing agent is used for the adhesive 4, it is possible to obtain an imaging device having a very small effect on heat.

The infrared cut filter 5 is provided between the lens unit 2a and the image pickup device 1. However, since the imaging condition does not change regardless of the position between the lens unit 2a and the imaging device 1, the fixing position and fixing method of the infrared cut filter 5 are not specified in the present embodiment. For example, as shown in FIG. 1, it may be adhered on the substrate 3A, or a protrusion may be provided on a part of the inner wall of the support member 2b for attachment, and may be adhered and fixed to the protrusion. .

By configuring the imaging device as described above, the number of components can be reduced.

FIG. 11 shows an error affecting the focusing performance in the image pickup apparatus according to the present embodiment.

First, it is assumed that a back focus error caused by a shape error of the imaging optical system 2 at the time of molding is ΔA.
In the imaging optical system 2, when the support member 2b is put into the second mold 8 and integrally formed with the lens portion 2a, the support member 2a
Is heated and re-annealed. Therefore, the support member 2b
Is absorbed by the back focus error of the integrally formed imaging optical system 2, and the shape error of the support member 2b and the shape error of the lens portion 2a that occur when both the support member 2b and the lens portion 2a are manufactured as a single unit. The value of the back focus error ΔA of the integrally formed imaging optical system 2 is smaller than the value obtained by adding. Also, because of the integral molding, there is no error in the adhesive layer of the attachment portion between the lens portion 2a and the support member 2b, such as the thickness error ΔH in FIG.

Next, considering the error of the infrared cut filter 5, since the imaging condition does not change regardless of the position between the lens unit 2a and the image pickup device 1 as described above, the position error due to adhesion Even if there is, there is no effect on the focusing performance. Therefore, only the variation in the thickness of the infrared cut filter 5 affects the focusing performance, and the error is defined as a value ΔB when converted into air in consideration of the refractive index.

Next, regarding the joint between the support member 2b of the imaging optical system 2 and the substrate 3A, the bottom surface of the support member 2b is
A, and the side surface of the support member 2b and the substrate 3A are bonded to each other with the adhesive 4, so that the support member 2b and the substrate 3
No error occurs in the thickness of the adhesive layer between A and A. Therefore, there is no error that affects the focusing performance of the lens unit 2a.

Next, the thickness error of the substrate 3A is ΔF, the thickness error of the imaging device 1 (error of the distance from the bottom surface to the surface of the effective pixel area 1a) is ΔC, and the adhesion between the imaging device 1 and the substrate 3A is Let ΔD be the thickness error of layer 6.

In the structure of the present invention, since the back focus is determined by the distance from the lens section 2a to the effective pixel area 1a, the thickness error ΔC of the image sensor 1 does not become an error factor. Therefore, it is possible to reduce a factor of an error affecting the focusing performance.

To summarize the above, the total value of the errors affecting the focusing performance is (ΔA + ΔB + ΔF + ΔD).
If this total value is smaller than the error Δδ of the depth of focus of the imaging optical system 2, it is not necessary to adjust the focus.

Here, the above-mentioned individual errors will be examined based on specific numerical examples. In order to configure a small and thin imaging device, for example, the angle of view of the imaging optical system 2 is set to a standard angle of view of 55 degrees, and the size of the effective pixel area 1a of the imaging element 2 is set to 1/4 inch optical system size , Support member 2b
Is about 5 to 10 mm, the back focus error ΔA is assumed to be about ± 30 μm.

Next, the thickness error ΔB caused by the infrared cut filter 5 is as follows. Infrared cut filter 5
Is often made of glass. The refractive index of glass is n
= 1.5. It is assumed that the thickness of the infrared cut filter 5 is 0.55 mm and the thickness variation is ± 50 μm.

Definition of refractive index n ₁₂ = v ₁ / v ₂ (n ₁₂ is the refractive index of medium 2 with respect to medium 1, v ₁ is the speed at which light travels through medium 1, and v ₂ is the speed at which light travels through medium 2 Speed) than air (n
= 1.0) If the distance that light travels in unit time in A is A,
The distance that light travels in the glass per unit time is A / 1.5. Therefore, if the moving distance of the light in the glass is converted into air, the error ΔB is ΔB = ± 50 μm × (1-1 / 1.
5) = ± 16.6 μm

Next, the thickness error ΔF of the substrate 3A is as follows. When configuring a thin imaging device, a flexible substrate is often used as the substrate 3A. A thin flexible substrate has a film thickness of 50 μm or less, and its variation error ΔF is about ± 3 to 4 μm (here, for example, ± 3.5 μm, and a flexible substrate having a film thickness of 28 μm actually exists. In this case, the thickness variation error is even smaller).

The thickness error ΔD of the adhesive layer 6 is as follows. When bonding the imaging device 1 and the substrate 3A,
If flip-chip mounting in which the electrode 1b of the imaging element 1 is directly connected to the electrode 3b of the substrate 3A is employed, and a connection method using solder bumps is used, the thickness error ΔD can be suppressed within a range of several μm (here. For example, ± 4μm
And).

Accordingly, as an example of the total value of the errors affecting the focusing performance of the imaging apparatus according to the present embodiment, (ΔA + ΔB + ΔF + ΔD) = ± 30 ± 1
6.6 ± 3.5 ± 4 = ± 54.1 μm.

When each error of the image pickup apparatus according to the present embodiment is individually compared with each error of the conventional image pickup apparatus shown in FIG. 18, first, the back focus error ΔG due to the shape error of the lens 33 in FIG. The back focus error ΔA due to the shape error of the imaging optical system 2 in FIG. 11 is smaller than the sum of the shape error ΔJ of the member 32 due to the integral molding. Furthermore, in the imaging device according to the present embodiment, since the support member 2b and the lens portion 2a are not joined by the adhesive layer, the adhesive layer 40 shown in FIG.
Does not occur.

Further, in the imaging device according to the present embodiment, since the upper surface of the imaging device 1 is bonded to the lower surface of the substrate 3A by flip-chip mounting, the thickness error ΔC of the imaging device 35 affects the focusing performance. It is not added to the given error factor.

In the conventional imaging apparatus, when it is difficult to integrally form the lead 36 and the support member 32, the use of the adhesive layer 39 can be considered, and the thickness error ΔK is further added to the error factor. On the other hand, according to the present embodiment, since the support member 2b is directly applied to the substrate 3A and the outside is surrounded by the adhesive 4, the support member 2b and the substrate 3A
No error occurs in the thickness of the adhesive layer.

In this embodiment, the thickness error ΔF of the substrate 3A and the adhesive layer 6
Are added, but the values of those errors are significantly smaller than the values of other errors as seen in the above numerical examples.

Here, individual errors of the conventional imaging apparatus will be examined based on specific numerical examples.

For example, the back focus error ΔG of the lens 33 in FIG. 18 is ± 10 μm, and the shape error ΔJ of the support member 32 is ± 30 μm. If the thickness of the image sensor 35 is, for example, 400 μm, the thickness error is ΔC = ± 4.
About 0 μm occurs. In addition, the infrared cut filter 34
Is the same as that in the case of the imaging apparatus according to the present embodiment, so that ΔB = ± 16.6 μm based on the above numerical example.
m. The thickness error ΔH of the adhesive layer 40 between the lens 33 and the support member 32 is several μm or less (for example, 4 μm
And).

Therefore, in the case of the conventional imaging apparatus, the value of the error (ΔG + ΔJ + ΔC + ΔB + ΔH) is (± 10 ±
30 ± 40 ± 16.6 ± 4) = 100.6 μm.
This value and the above (ΔA + ΔB + ΔF + ΔD) = ± 54.
As can be seen from a comparison with 1 μm, in the configuration of the imaging apparatus according to the present embodiment, the value of the error affecting the focusing performance is significantly reduced, and the accuracy in assembling the components can be improved. it can. Therefore, it is easy to achieve no focus adjustment.

When the image pickup apparatus according to the present embodiment is used, the image pickup optical system 2 is formed of a lens 2a formed of a transparent material and a material that holds the lens 2a and does not transmit light. Lens member 2
Since a and the support member 2b are integrally formed, the number of component parts can be reduced. Further, it is possible to reduce an error that occurs when assembling the components and manufacturing the imaging device and affects the focusing performance. Therefore, it is easy to achieve no focus adjustment.

Further, the supporting member 2b formed by the first mold 7 is inserted into the second mold 8, and thereafter, the transparent material is injected into the second mold 8, whereby the lens portion 2a is formed. Since the lens portion 2a and the support member 2b are integrally molded by insert molding, two members having different injection speed conditions can be integrally molded. Further, it is also possible to integrally mold an imaging optical system in which members having different colors and members having different characteristics such as a coefficient of thermal expansion are combined.

<Embodiment 2> The imaging apparatus according to the present embodiment is a modification of the imaging apparatus according to Embodiment 1.

In the present embodiment, as shown in FIG. 12, the infrared cut filter 5 is arranged outside the imaging optical system 2 on the incident side of the lens unit 2a. In such an arrangement, the thickness error ΔB caused by the infrared cut filter 5 can be eliminated from the error factors. In that case, in the numerical example shown above, (ΔA + ΔF + Δ
D) = ± 30 ± 3.5 ± 4 = ± 37.5 μm.

Therefore, in the configuration of the imaging apparatus according to the present embodiment, the value of the error that affects the focusing performance is further reduced, and it is easier to adjust the focus.

<Third Embodiment> An imaging device according to the present embodiment is also a modification of the imaging device according to the first embodiment.

In the present embodiment, as shown in FIG. 13, the image pickup device 1 is arranged on a substrate 3B. That is, the lower surface of the image sensor 1 is bonded to the upper surface of the substrate 3B via the bonding layer 10.

FIG. 14 is a view of the substrate 3B and the image pickup device 1 as viewed from above. The electrode 1b on the image sensor 1 and the electrode 3b on the substrate 3B are connected by a bonding wire 1c. A circuit pattern 3c for connecting the electrode 3b to another device is formed on the substrate 3B.

In the configuration of the imaging apparatus of the present embodiment,
FIG. 15 shows an error affecting the focusing performance. In this case, the back focus error ΔA caused by the shape error of the imaging optical system 2, the error ΔB caused by the thickness error of the infrared cut filter 5, the thickness error ΔC of the image sensor 1, the substrate 3
The thickness error ΔE of the adhesive layer 10 between the camera and the imaging device 1 is an error factor that affects the focusing performance.

Specific numerical examples of the errors ΔA, ΔB, and ΔC are as described above. In addition, the value of the thickness error ΔE of the adhesive layer 10 is an error of several μm when the thickness of the adhesive layer 10 is considered to be about 30 to 50 μm. Here, the back focus error ΔA is smaller than the sum of the back focus error ΔG and the shape error ΔJ, and the error ΔE
And the value of the error ΔH are substantially the same, the total value of the errors (ΔG + ΔJ +
From ΔC + ΔB + ΔH), the total value of errors (ΔA + ΔE + ΔC + Δ) generated in the configuration of the imaging apparatus according to the present embodiment is obtained.
Since B) is smaller, the variation error can be reduced even by the configuration of the imaging apparatus according to the present embodiment.

[0080]

According to the first aspect of the present invention, the imaging optical system has a lens portion formed of a transparent material, and a support member holding the lens portion and formed of a light-shielding material. Since the lens portion and the support member are integrally formed, the number of component parts can be reduced. In addition, the shape error of the support member is absorbed by the back focus error of the imaging optical system that is integrally formed, and the shape error of the support member and the shape error of the lens portion that occur when both the support member and the lens unit are manufactured as a single unit. The value of the back focus error of the integrally formed imaging optical system is smaller than the value obtained by adding. It is possible to reduce errors that affect focusing performance and occur when an imaging device is manufactured by assembling the components. Therefore, it is easy to achieve no focus adjustment.

According to the second aspect of the present invention, the support member formed by the first mold is inserted into the second mold,
Thereafter, the lens portion and the support member are integrally formed by insert molding in which the transparent material is injected into the second mold to form the lens portion.
The two members can be integrally formed. Further, it is also possible to integrally mold an imaging optical system in which members having different colors and members having different characteristics such as a coefficient of thermal expansion are combined.

According to the third aspect of the present invention, the main surface of the image pickup device has the second surface while exposing the effective pixel region to the opening.
And the supporting member of the imaging optical system is held on the first main surface. Therefore, the thickness error of the imaging device does not become an error factor, and the error factor affecting the focusing performance is reduced. can do.

According to the fourth aspect of the present invention, since the side surface of the support member and the portion of the main surface of the substrate which are not covered by the bottom surface of the support member are bonded by the adhesive, the support member and the substrate are bonded together. No adhesive layer is formed between the layers, and an error in the thickness of the adhesive layer can be eliminated. Therefore, it is possible to reduce a factor of an error affecting the focusing performance.

According to the fifth aspect of the present invention, since the adhesive has a light-shielding property, even if there is a slight gap between the support member and the substrate, light is transmitted therefrom to the inside of the imaging optical system. Do not invade.

According to the sixth aspect of the present invention, since the adhesive is a UV curing agent, bonding can be performed at a low temperature, and there is no problem that the imaging optical system is deformed at the time of bonding. In addition, since the material itself shrinks little during curing, misalignment is unlikely to occur between the imaging optical system and the substrate. Further, it is possible to obtain an imaging device having an extremely small effect on heat.

According to the seventh aspect of the present invention, since the infrared cut filter is disposed outside the imaging optical system and on the incident side of the lens unit, the thickness error caused by the infrared cut filter is excluded from the error factors. be able to. Therefore, it is possible to reduce a factor of an error affecting the focusing performance.

[Brief description of the drawings]

FIG. 1 is a diagram showing an imaging device according to a first embodiment.

FIG. 2 is an enlarged view showing a joint between an image sensor 1 and a substrate 3A of the image pickup apparatus according to Embodiment 1.

FIG. 3 is a bottom view of the substrate 3A of the imaging device according to the first embodiment;

FIG. 4 is a support member 2b of the imaging device according to the first embodiment;
FIG. 6 is a side view showing a first mold 7 for injection-molding a mold.

FIG. 5 is a support member 2b of the imaging device according to the first embodiment;
FIG. 6 is a side view showing a first mold 7 for injection-molding a mold.

FIG. 6 is a support member 2b of the imaging device according to the first embodiment.
FIG. 3 is a perspective view showing a first mold 7 for injection-molding a mold.

FIG. 7 is a perspective view showing a support member 2b formed by injection molding.

FIG. 8 illustrates a lens unit 2a of the imaging device according to the first embodiment.
Mold 8 for integrally molding the support member 2b and the support member 2b
FIG.

FIG. 9 illustrates a lens unit 2a of the imaging device according to the first embodiment.
Mold 8 for integrally molding the support member 2b and the support member 2b
FIG.

FIG. 10 illustrates a lens unit 2 of the imaging device according to the first embodiment.
FIG. 7 is a side view showing a state in which a second mold 8 for integrally molding the supporting member 2a and the support member 2b is vertically aligned.

FIG. 11 is a diagram illustrating an error affecting the focusing performance of the imaging device according to the first embodiment;

FIG. 12 is a diagram showing an imaging device according to a second embodiment.

FIG. 13 is a diagram showing an imaging device according to a third embodiment.

FIG. 14 is a top view showing a substrate 3B and an image sensor 1 of the image pickup apparatus according to Embodiment 3.

FIG. 15 is a diagram illustrating an error affecting the focusing performance of the imaging device according to the third embodiment;

FIG. 16 is a diagram illustrating a conventional imaging device.

FIG. 17 is a diagram illustrating a conventional imaging device.

FIG. 18 is a diagram illustrating an error affecting a focusing performance of a conventional imaging device.

[Explanation of symbols]

1 imaging device, 2 imaging optical system, 2a lens unit, 2b
Support member, 3A, 3B substrate, 4 adhesive, 5 infrared cut filter, 6 adhesive layer, 7 first die, 8
Second mold, 9 valves, 10 adhesive layers.

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[Procedure amendment]

[Submission date] November 22, 2000 (200.11.
22)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction contents]

When molding an optical member such as the lens portion 2a, the molding may be performed by low-speed injection in order to avoid traces of flowing transparent material (flow marks), burning and jetting. General. On the other hand, for other members, high-speed injection molding, which requires a relatively short time, is often performed in order to increase mass production efficiency. Also in the present invention, the lens portion 2a may be formed by low-speed injection, and the support member 2b may be formed by high-speed injection. By using the insert molding as described above, two members having different injection speed conditions can be integrally molded. If insert molding is used, it is also possible to integrally mold an imaging optical system in which members having different colors, such as the lens portion 2a and the support member 2b, and members having different characteristics such as the coefficient of thermal expansion are combined.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Explanation of sign

[Correction method] Change

[Correction contents]

[Description of Signs] 1 imaging device, 2 imaging optical system, 2a lens unit, 2b
Support member, 3A, 3B substrate, 4 adhesive, 5 infrared cut filter, 6 adhesive layer, 7 first die, 8
Second mold, 9 valves, 10 adhesive layers , 2c ink
Project department .

Continuing from the front page (72) Inventor Hiroaki Sugiura 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Takayuki Yamazaki 3000 Mita, Atsugi-shi, Kanagawa Prefecture Reference) 2H044 AB19 4M118 AA10 AB01 BA10 BA14 GC11 HA02 HA11 HA23 HA30 HA31 HA33 5C022 AB13 AC42 AC54 AC55 AC70 AC78 5C024 CY47 CY48 CY49 EX21 EX42 EX51 GY01 GY31

Claims (7)

[Claims] An imaging device that converts an optical image formed into an electric signal; a substrate that holds the imaging device; and an imaging optical system that is held by the substrate and forms the optical image on the imaging device. The imaging optical system includes: a lens unit formed of a transparent material; and a support member holding the lens unit and formed of a light-shielding material. An imaging device in which members are integrally formed. 2. The imaging device according to claim 1, wherein the light-shielding material is injected into a first mold to form the support member, and the light-shielding material is molded by the first mold. The lens part and the support member were integrally formed by insert molding in which the support member was inserted into a second mold, and then the transparent material was injected into the second mold to form a lens part. Imaging device. 3. The imaging device according to claim 1, wherein the imaging element has an effective pixel area on a main surface thereof, which is an area where incident light of the optical image can be sensed, and the substrate has an opening. A portion, a first main surface, and a second main surface opposite to the first main surface, wherein the incident light reaches the effective pixel region of the imaging device through the opening, The main surface of the imaging device is adhered to the second main surface while exposing the effective pixel region to the opening, and the support member of the imaging optical system is held on the first main surface. Imaging device. 4. The imaging device according to claim 1, wherein the substrate has a main surface, the support member of the imaging optical system has a bottom surface and a side surface, and the bottom surface of the support member is the bottom surface. An imaging device which is applied to the main surface of a substrate, wherein the side surface of the support member and a part of the main surface of the substrate which is not covered by the bottom surface of the support member are bonded with an adhesive. 5. The imaging device according to claim 4, wherein the adhesive has a light shielding property. 6. The imaging device according to claim 4, wherein the adhesive is a UV curing agent. 7. The imaging apparatus according to claim 1, further comprising an infrared cut filter, wherein the infrared cut filter is provided outside of the imaging optical system and arranged on an incident side of the lens unit. apparatus.