JP2013190659A - Double eye camera device, range finder, and method for manufacturing the double eye camera device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double eye camera device capable of suppressing variation in manufacturing accuracy.SOLUTION: A double eye camera device comprises: an imaging lens array 11 formed with a plurality of imaging lenses on a singular lens material; an image taking element array 14 formed with a plurality of image taking areas, on a singular semiconductor wafer, that respectively receive imaging luminous fluxes emitted from the respective imaging lenses; and a spacer 13 for holding a space between the imaging lenses 11a, 11b and the image taking areas 14a, 14b. An imaging surface side of the image taking element array 14 is directly connected to one side of the spacer 13 and a light emitting surface side of the imaging lens array 11 is directly connected to the other side of the spacer 13.

Description

  The present invention is used for various purposes such as in-vehicle use, monitoring use, medical use, surveying use, robot use, and game use, and uses a compound eye camera device and compound eye camera device used when measuring the distance to an object. The present invention relates to a distance measuring apparatus and a compound eye camera apparatus manufacturing method.

2. Description of the Related Art Conventionally, distance measuring devices that measure the distance to an object (subject) based on triangulation have been proposed.
A distance measuring device that measures the distance to a subject based on triangulation arranges an imaging optical system that forms an image of a subject on two light receiving elements so that the respective light receiving optical axes are parallel, The detected images are compared, and the distance to the subject is measured by detecting the deviation of the same subject.

FIG. 8 is a diagram showing the basic principle of triangulation by the distance measuring device.
In FIG. 8, a case is considered in which light from the subject 101 is photographed by arranging two cameras (first camera 102a and second camera 102b) having the same optical system.
The first camera 102a and the second camera 102b are fixed on the base substrate 106, for example, and are arranged so that their optical axes are parallel to each other.
In the first camera 102a, the subject image 107a acquired through the first lens 103a is projected onto the image sensor 104a with the same point on the subject image shifted from the optical axis by Δ1, and there are many in the image area on the image sensor 104a. The light receiving element (pixel) receives the light and converts it into an electrical signal.
Similarly, in the second camera 102b, the subject image 107b acquired through the second lens 103b is projected onto the image sensor 104b with the same point on the subject image shifted from the optical axis by Δ2, and the image area on the image sensor 104b is projected. Are received by a number of light receiving elements (pixels) and converted into electrical signals.
The parallax δ occurs as a shift in a direction perpendicular to the two optical axes in a plane including the two optical axes. Therefore, when the arrow direction of the subject 101 is a plus coordinate and the opposite direction is a minus coordinate, the subject image 107a is displaced by δ1 in the plus direction and the subject image 107b is displaced by δ2 in the minus direction, so that δ = δ1-(− δ2).

Here, the distance between the optical axes of the lenses 103a and 103b is called a base line length, which is D, where L is the distance from the subject to the lens, f is the focal length of the lens, and L >> f. L is
L = D × f / δ (1)
It becomes.
Since the base line length D and the focal length f of the lens are known design values and are known, the distance L to the subject 101 can be calculated by detecting the parallax Δ.

In addition, the technique which ensures the ranging accuracy of a ranging apparatus is disclosed by patent document 1, 2, etc., for example.
Patent Document 1 describes the purpose of maintaining the desired distance measurement accuracy even when the ambient environment of temperature and humidity changes and the distance measurement lens, which is a resin molded product, and the housing that holds them expand and contract. A housing for holding a pair of distance measuring lenses and a distance measuring circuit board having a sensor surface disposed on an image forming surface of each of the lenses at a predetermined interval. A configuration for molding with a thermosetting resin is disclosed.
In Patent Document 2, a plurality of subject images by a plurality of lenses having different optical axes are provided for the purpose of providing a compound eye type camera module capable of measuring a stable distance with respect to a change with time and ambient temperature with a simple initial correction. Is imaged in a plurality of imaging areas corresponding to each of the plurality of lenses on a one-to-one basis, and distance information of the subject is obtained by comparing electric signals output from the plurality of imaging areas, respectively. The plurality of lenses are integrated with an arrangement in which optical axes are substantially parallel to each other, and a configuration in which the plurality of imaging regions are formed on a single semiconductor wafer is disclosed. Yes.

However, in Patent Document 1, since a pair of lenses are attached as independent components, variations in accuracy occur between the lenses during manufacturing. Moreover, in patent document 1, dispersion | variation arises in the parallelism of the optical axis of the lens attached to the housing. For this reason, Patent Document 1 has a problem in that the distance measurement accuracy is lowered.
In Patent Document 2, a pair of lenses are formed by an integrated part to prevent variations in accuracy between the lenses during manufacturing. As a result, the following problems have been encountered. That is, in Cited Document 2, the lens is attached to the bottom surface of the lens barrel, and the solid-state imaging device is attached to the bottom surface of the lens barrel via the substrate including the DSP. However, the substrate has a problem that the accuracy is poor in terms of the flatness of the substrate surface and the parallelism of the front and back surfaces of the substrate. Further, when the solid-state imaging device is attached to the bottom surface of the lens barrel via the substrate, there is a problem that the perpendicularity between the optical axis of the lens and the imaging surface of the solid-state imaging device is deteriorated.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a compound eye camera device that can suppress variations during manufacturing.

  In order to achieve the above object, the invention according to claim 1 includes an imaging lens array having a plurality of imaging lenses and a plurality of imaging regions formed on a semiconductor wafer, and emitted from each imaging lens. An imaging element array that receives the imaging light flux in each of the imaging areas, and a spacing holding member that holds a spacing between the imaging lens and the imaging area, and the imaging area surface side of the imaging element array is the spacing A compound-eye camera device that is directly connected to one of the holding members and in which the exit surface side of the imaging lens array is directly connected to the other of the spacing members.

  According to the present invention, the imaging element array is directly connected to one of the interval holding members, and the imaging lens array is directly connected to the other of the interval holding members, so that the optical axes are parallel between the imaging lenses. And variation in perpendicularity between the optical axis of the imaging lens and the imaging region can be suppressed.

It is sectional drawing which shows schematic structure of the ranging device which concerns on the 1st Embodiment of this invention. It is the figure which showed the other structural example of the solid-state image sensor. It is explanatory drawing of the semiconductor wafer of a general purpose goods, and the semiconductor wafer of a custom goods. It is the figure which showed the manufacturing process of the compound eye camera apparatus in the distance measuring device which concerns on 1st Embodiment. It is the schematic explanatory drawing which showed the relationship between the distance (pitch) between the imaging regions of a solid-state image sensor, and a base line length. It is sectional drawing which showed the structure of the spacer used for the ranging apparatus which concerns on the 2nd Embodiment of this invention. It is sectional drawing which showed the structure of the spacer used for the ranging apparatus which concerns on the 3rd Embodiment of this invention. It is a figure which shows the basic principle of the triangulation by a distance measuring device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a cross-sectional view showing a schematic configuration of a distance measuring apparatus according to a first embodiment of the present invention.
A distance measuring device 1 shown in FIG. 1 includes a compound eye camera device 10 and an image sensor substrate 16. The compound-eye camera device 10 includes an imaging lens array 11, an aperture (light-shielding member) 12, a spacer (interval holding member) 13, a solid-state imaging device 14, and a cover glass (protective member) 15.
In the imaging lens array 11, two imaging lenses 11a and 11b are formed on the same imaging lens material. The imaging lenses 11a and 11b are, for example, aspheric lenses.
The optical axes c1 and c2 of the two imaging lenses 11a and 11b are parallel to the normal line N of the plane on which the two imaging lenses 11a and 11b are arranged.

The aperture 12 is provided on the upper surface side (subject side) of the imaging lens array 11 and shields light so that the apertures of the imaging lenses 11a and 11b formed in the imaging lens array 11 are substantially equal.
The spacer 13 is an interval holding member that is provided on the lower surface side (the side opposite to the subject) of the imaging lens array 11 and secures an imaging distance from the imaging lens array 11 to the solid-state imaging device 14. The spacer 13 has openings (through holes) 13a and 13b having optical axes c1 and c2 as centers. The insides of the openings 13a and 13b are cavities (air layers), and the inner wall surfaces of the openings 13a and 13b are subjected to a light reflection preventing process. Examples of the antireflection processing include black coating processing, rough surface processing, matting processing, and the like. When antireflection processing is performed on the inner wall surfaces of the openings 13a and 13b, stray light reflected by the inner wall surfaces of the openings 13a and 13b can be prevented from entering a solid-state imaging device 14 described later.

Further, when antireflection treatment is applied to the inner wall surfaces of the openings 13a and 13b, light transmission can be suppressed even if the base material of the spacer 13 is transparent to visible light. Crosstalk of light to the imaging regions 14a and 14b adjacent to the imaging element 14 can be suppressed.
A solid-state imaging device 14 is attached to the lower surface of the spacer 13 (the surface opposite to the attachment surface of the imaging lens array 11).

In the solid-state imaging device 14, for example, three imaging regions 14a, 14b, and 14c are arranged in a line, and the centers of the imaging regions 14a and 14b at both ends thereof are the lights of the two imaging lenses 11a and 11b of the imaging lens array 11. It is arranged to be on the axis. That is, the distance between the imaging regions 14a and 14b of the solid-state imaging device 14 is configured to be the baseline length of the distance measuring device. The baseline length may be determined according to the distance to the object to be measured and the measurement accuracy.
In the present embodiment, the distance between the imaging regions 14a and 14b at both ends of the three imaging regions 14a to 14c is configured to be the baseline length of the distance measuring device. As shown in FIG. 2A, a solid-state imaging device is configured using two imaging regions 14a and 14b, or the four imaging regions 14a to 14d arranged in a row are arranged at both ends thereof. You may make it comprise the solid-state image sensor 14 using 14a, 14b.
Although details will be described later, the solid-state image sensor 14 of the compound-eye camera device used for the distance measuring device using the imaging regions 14a and 14b at both ends of the image sensor array in which a plurality of image sensors are arranged in a line is used. If comprised, the cost reduction of a solid-state image sensor can be achieved.

The cover glass 15 is provided on the light receiving surface side of the solid-state imaging device 14 in order to protect the imaging regions 14a and 14b of the solid-state imaging device 14 from scratches and dust.
Although not shown, a TSV (Through Silicon Via) is formed in the solid-state imaging device 14, and an extraction electrode for drawing out the output of each imaging region 14 a, 14 b, 14 c is provided on the lower surface side (light receiving surface) of the solid-state imaging device 14. Is formed on the opposite side.
The image pickup device substrate 16 includes an electrical component such as a digital signal processor (DSP) as a calculation means for executing calculation processing for calculating the distance from the output signal of the solid-state image pickup device 14 to the subject. A lead electrode (not shown) of the solid-state image sensor 14 is mounted (SMT (Surface Mount Technology) on the electrode pad 17 of the image sensor substrate 16 via a BGA (Ball Grid Array).

Here, the solid-state imaging device 14 of the present embodiment will be described.
In the present embodiment, the solid-state imaging device 14 is formed using a general-purpose product in which a large number of imaging regions 32 are formed in a matrix on a single semiconductor wafer 31 as shown in FIG. Yes. If the solid-state imaging device 14 is formed using a general-purpose semiconductor wafer 31, the cost of a distance measuring device including a compound eye camera device can be reduced.
This is because the solid-state imaging device 14 used in the compound-eye camera device has the same base line length and the wafer size cut out from the semiconductor wafer 31 is almost the same, so that it can be taken out from a single semiconductor wafer. 14 is the same for the general-purpose semiconductor wafer 31 shown in FIG. 3A and the custom-made semiconductor wafer 41 shown in FIG. Therefore, when the solid-state imaging device 14 is taken out as shown in FIG. 3C from the inexpensive general-purpose semiconductor wafer 31 shown in FIG. 3A, and the expensive custom-made semiconductor shown in FIG. When the solid-state imaging device 14 is taken out from the wafer 41 as shown in FIG. 3D, the imaging region is wasted when the solid-state imaging device 14 is taken out from the general-purpose semiconductor wafer 31 shown in FIG. The solid-state image sensor 14 can be manufactured at a lower cost than when the solid-state image sensor is taken out from the expensive custom-made semiconductor wafer 41 shown in FIG.

Further, in consideration of the yield in the wafer plane, in the case of the custom-made semiconductor wafer 41 as in the comparative example, the yield decreases by the number of defects in the element region, but the general-purpose semiconductor wafer 31 was used. In such a case, it is possible to suppress a decrease in yield by cutting out a defective imaging region so that it becomes a position not used for sensing (regions 14c and 14d in FIG. 3D). Can be achieved.
In Cited Reference 2, a solid-state imaging device is formed by dicing so as to include two imaging areas out of imaging areas formed in a matrix on a single semiconductor wafer. Since it is necessary to change the photomask according to the length, the semiconductor wafer of the cited document 2 becomes the custom-made semiconductor wafer 41 as described above. Therefore, in Cited Document 2, it is impossible to realize a cost reduction of the most expensive solid-state imaging device among the members.

Next, a method for manufacturing the distance measuring device according to the present embodiment will be described.
FIG. 4 is a diagram illustrating a manufacturing process of the distance measuring apparatus according to the first embodiment. In addition, the same code | symbol is attached | subjected to the same site | part as FIG. 1, and description is abbreviate | omitted.
First, in the step shown in FIG. 4A, the solid-state imaging device 14 is prepared.
The solid-state imaging device 14 shown in FIG. 4A is configured by a triple CMOS sensor array in which three imaging regions 14a, 14b, and 14c are arranged in a straight line. In such a solid-state imaging device 14, a plurality of imaging regions 14a, 14b, 14c,... Are formed on the upper surface (front surface) of a 6-inch or 12-inch silicon wafer, and a cover glass 15 is attached to the upper surface. It has been. Further, although not shown in the figure, the silicon wafer is subjected to TSV processing so that the output of each imaging region 14a, 14b, 14c can be extracted from the extraction electrode provided on the lower surface of the silicon wafer. A BGA 18 is formed on the lead electrode on the lower surface of the silicon wafer. Further, in the solid-state imaging device 14, the silicon wafer is cut according to the baseline length.

The cover glass 15 is made of, for example, AF45 manufactured by shot, which has a linear expansion coefficient close to that of the silicon wafer that is the material of the solid-state imaging device 14.
The BGA 18 can be mainly made of a tin (Sn), silver (Ag), or copper (Cu) based alloy that does not contain lead. Sn-30% Ag-0.5% Cu is the mainstream, but a high silver content leads to an increase in cost, so Sn-10% Ag-0.7% Cu, Sn-0. 3% Ag-0.7% Cu, Sn-0.1% Ag-0.7% Cu, or the like may be used.

FIG. 5 is a diagram showing the relationship between the distance (pitch) between the imaging regions of the solid-state imaging device 14 and the baseline length.
The solid-state imaging device 14 according to the present embodiment includes three imaging regions 14a, 14b, and 14c having a distance P between the imaging regions of 3.3 mm, and the distance between the centers of the imaging regions 14a and 14b at both ends thereof is the baseline. It becomes the length D. Therefore, in the present embodiment, the base line length D of the solid-state imaging device 14 is 6.6 mm. The distance between the two imaging lenses 11a and 11b was set to 6.6 mm according to the baseline length D.
The solid-state imaging device 14 of the present embodiment uses a general-purpose semiconductor wafer used in a monocular camera module that has been put on the market in large quantities such as mobile phones by cutting it to a required baseline length. Therefore, there is an advantage that it can be manufactured at low cost.

Next, in the step shown in FIG. 4B, the spacer 13 is directly attached to the upper surface (front surface) of the cover glass 15 attached to the upper surface of the solid-state imaging device 14. The centers of the openings (through holes) 13a and 13b of the spacer 13 are pasted with their positions aligned so as to be the centers of the imaging regions 14a and 14b located at both ends of the solid-state imaging device 14, respectively.
For the spacer 13, for example, a glass material is used as a base material. The glass material used as the base material of the spacer 13 was selected from materials having a linear expansion coefficient higher than that of the solid-state imaging device 14 and lower than that of the imaging lens array 11. In particular, it is preferable to select a material having a linear expansion coefficient intermediate between the linear expansion coefficients of the solid-state imaging device 14 and the imaging lens array 11.
As an example of the glass material of the base material, for example, BK7 manufactured by shot was used. Although details will be described later, in addition to BK7 made by shot, B270 made by shot generally called white glass is also a preferable material because of the relationship of the linear expansion coefficient.
The glass material employed in the spacer 13 can be polished to ensure a flat and smooth joint surface in a wide range, and when optical glass is used, by satisfying the required linear expansion coefficient of the spacer 13, There is an effect that it is easy to secure the bonding strength of the imaging lens array 11 and the solid-state imaging device 14 and the spacer 13.

Next, in the step shown in FIG. 4C, the imaging lens array 11 is directly attached to the surface of the spacer 13. At this time, the imaging lenses 11a and 11b are pasted with their positions aligned so that the centers of the imaging lenses 11a and 11b become the centers of the imaging regions 14a and 14b located at both ends of the solid-state imaging device 14, respectively.
The imaging lens array 11 is formed by heating a mold of an optical glass material with an infrared lamp and pressing it with vacuum. Since the imaging lenses 11a and 11b are simultaneously formed using a single optical glass material as a base material, the characteristics of the two imaging lenses 11a and 11b can be made uniform, which is suitable for a distance measuring device.
As the optical glass material, for example, K-PG375 (Vidron) manufactured by Sumita Optical Co., Ltd. is used. However, a material that can be molded at a low temperature, such as K-PG325 (Super Vidron), or other optical materials may be used. However, Sumida Optical's K-PG375 and K-PG325 are suitable as materials that can be molded at a low temperature, and can be said to be suitable optical glass materials for producing the imaging lens array 11 of this structure.

  Moreover, a glass lens and a plastic lens can be selected as the imaging lenses 11a and 11b. However, since the imaging lens array 11 formed monolithically has a length corresponding to the parallax as compared with a single-lens lens, it is better to use a glass lens having a smaller linear expansion coefficient difference from the solid-state imaging device 14. There is an effect that it becomes easy to secure the bonding strength between the imaging lens array 11 and the spacer 13. A glass lens is also advantageous in terms of heat resistance, and is a more preferable material in the present configuration in which reflow is performed after the lens is assembled.

Next, in the step shown in FIG. 4D, the aperture 12 is directly attached to the surface of the imaging lens array 11. At this time, the two aperture centers of the aperture 12 are pasted with their positions aligned with the centers of the imaging lenses 11a and 11b.
As the aperture 12, for example, a SUS430 material having a thickness of 0.25 mm was processed by etching. The aperture 12 may be a metal material other than the SUS430 material. Also, other materials and construction methods may be used. Of the light incident on the distance measuring device, light incident on the distance measuring device from other than the lens is cut to improve the S / N of the imaging regions 14a and 14b. You may make it show.
Thereby, the compound eye camera apparatus 20 of this embodiment is producible.
In addition, it is preferable to use the adhesive which can endure the lead free reflow of about 270 degreeC, and the process shown to the said FIG.4 (b)-FIG.4 (d), such as a heat resistant epoxy adhesive, a modified | denatured silicon adhesive, etc. Is suitable.

Here, Alemco Bond 570 (developed by Alemco Products, USA), which is a high heat-resistant epoxy adhesive, was used. Alemcobond 570 is a one-component adhesive having a heat resistant upper limit of 316 ° C. It is a highly productive material that can withstand lead-free reflow and is easy to handle due to its one-part nature. The thickness of the adhesive was adjusted to 0.2 mm, for example.
Next, in the step shown in FIG. 4E, the position of the BGA 18 of the compound-eye camera device manufactured in FIG. 4D is aligned with the electrode pad 18 on the image sensor substrate 16 and is passed through a reflow furnace. Mechanically and mechanically. Further, in order to improve the reliability of the joint between the image pickup device substrate 16 and the compound eye camera device, the underfill agent 20 is filled.
In this way, the distance measuring device according to this embodiment can be manufactured.

According to the manufacturing method described above, since the two imaging lenses 11a and 11b are integrally formed with the imaging lens array 11, the parallelism of the optical axes of the two imaging lenses 11a and 11b can be kept high.
Further, since the cover glass 15, the spacer 13, and the imaging lens array 11 are sequentially laminated on the basis of the upper surface of the solid-state imaging device 14, the imaging lenses 11a and 11b formed on the imaging lens array 11 and the solid image An error in the distance of the image sensor 14 can be reduced.
Furthermore, the spacer 13 can be polished to ensure a flat and smooth joint surface over a wide range, and the error in the distance between the imaging lenses 11a and 11b and the solid-state imaging device 14 can be reduced.
Further, since the members cut out into individual pieces are laminated, there is an advantage that they can be mounted on the image pickup device substrate 16 by reflow even after the members containing different materials are assembled.

Next, the difference in linear expansion coefficient of each member will be described. In addition, the value of the linear expansion coefficient demonstrated below is an example of the value in a manufacturing environment.
In the present embodiment, the imaging lens array 11, the spacer 13, and the solid-state imaging device 14 have a thickness of 2.3 mm, 1.4 mm, and 0.67 mm, respectively, and a bonding outer peripheral dimension is 10 mm × 3.3 mm. did.
The linear expansion coefficient of the solid-state imaging device (silicon semiconductor) 14 is 2 to 3 ppm / k, and the linear expansion coefficient of the cover glass (AF45 manufactured by shott) 15 is 4.5 ppm / k.
The linear expansion coefficient of the imaging lens 11 is, for example, 16.9 ppm / k if the material is K-PG375 (Vidron) and 16.5 ppm / k if the material is K-PG325 (Supervidron).
The linear expansion coefficient of BK7 manufactured by shot which is the spacer 13 is 8.3 ppm / k.

In the present embodiment, the material is selected so that the linear expansion coefficient of the spacer 13 is approximately halfway between the linear expansion coefficient of the cover glass 15 and the linear expansion coefficient of the imaging lens 11.
In this case, manufacture of the spacer 13 with silicon having a smaller linear expansion coefficient was attempted, but in this case, the difference in linear expansion coefficient with the imaging lens array 11 increased, and a problem of peeling occurred in the reflow process.
For this reason, in the present embodiment, the material is selected so that the linear expansion coefficient of the spacer 13 becomes a value approximately halfway between the linear expansion coefficients of the cover glass 15 and the imaging lens 11. Thereby, the problem of an above-mentioned reflow process can be solved.
In addition to the BK7 made of shot having a linear expansion coefficient of 8.3 ppm / k, B270 made of shot having a linear expansion coefficient of 9.4 ppm / k can also use the material of the spacer 13.

Further, since the linear expansion coefficient is different between the imaging lens 11 and the solid-state imaging device 14, the imaging lens array 11 having a large linear expansion coefficient with respect to the environmental temperature has a disadvantage that expansion and contraction becomes relatively large. Therefore, in this embodiment, although not shown, temperature measurement means such as a thermistor or a thermocouple may be provided, and the measurement accuracy may be ensured by correcting the measurement data.
<Second Embodiment>
Next, a distance measuring apparatus according to the second embodiment of the present invention will be described. Since the distance measuring device according to the second embodiment is different from the distance measuring device according to the first embodiment only in the structure of the spacer, only the structure of the spacer will be described here.
FIG. 6 is a cross-sectional view showing the configuration of the spacer used in the distance measuring apparatus according to the second embodiment of the present invention.
In the second embodiment, as in the first embodiment, BK7 made of shot, which is a kind of glass, is used for the base material 51 of the spacer 13. The spacer base material 51 is a member that is transparent to the visible light region, such as glass, and suppresses crosstalk that affects the distance measurement due to light leaking to the imaging regions 14a and 14b located at both ends of the solid-state imaging device 14. A light shielding member is required as a suppression means.
Therefore, in the second embodiment, the crosstalk is suppressed by forming the light shielding film 52 on the glass material which is the base material 51 of the spacer 13. The light shielding film 52 is formed by forming a chromium or nickel metal film. As a film forming method, a vacuum deposition method, a sputtering method, a plating method, or the like is effective. In particular, the plating method is more practical in securing the adhesion of the film.

As described in the first embodiment, the glass material used as the base material 51 of the spacer used in the second embodiment has a linear expansion coefficient higher than the linear expansion coefficient of the solid-state imaging device 14 and has the imaging lens array 11. It is selected from glasses having a linear expansion coefficient lower than the linear expansion coefficient.
In particular, it is preferable to select a material having a linear expansion coefficient that is intermediate between the linear expansion coefficients of the solid-state imaging device 14 and the imaging lens array 11.
As described above, in the second embodiment, the spacer 13 is formed of a glass member, and the metal film of chromium or nickel is formed on the glass member as a light shielding member. .
Further, when a glass material is used for the base material of the spacer 13, the glass material can be obtained over a wide range by optical polishing, so that a flat and smooth joint surface can be secured, and there is an advantage that ranging accuracy is improved.

<Third Embodiment>
Next, a distance measuring apparatus according to the third embodiment of the present invention will be described. Note that the distance measuring device according to the third embodiment differs from the distance measuring device according to the first embodiment only in the structure of the spacer, as in the distance measuring device according to the second embodiment. Now, only the structure of the spacer will be described.
FIG. 7 is a cross-sectional view showing the configuration of the spacer used in the distance measuring apparatus according to the third embodiment of the present invention.
The third embodiment is characterized in that the spacer 13 is formed of ceramics 61. The material of the ceramic 61 is preferably alumina, zirconia or the like. These materials are opaque to the visible light region, and the materials themselves have a light shielding effect, and it is not necessary to newly provide a light shielding member.

Here, the material of the ceramic 61 to be selected is selected from materials having a linear expansion coefficient higher than the linear expansion coefficient of the solid-state imaging device 14 and a linear expansion coefficient lower than that of the imaging lens array 11. In particular, it is preferable to select a material having a linear expansion coefficient that is intermediate between the linear expansion coefficients of the solid-state imaging device 14 and the imaging lens array 11, and is preferably 7 to 13 ppm / k, for example.
Many alumina ceramic materials having a linear expansion coefficient of 7 to 8 ppm / k and zirconia ceramic materials having a linear expansion coefficient of 10 to 11 ppm / k have been commercialized and are preferable materials.
As described above, in the third embodiment, when the spacer 13 is formed of a ceramic material, the ceramic material covers a wide range, and a flat and smooth joint surface can be ensured by polishing, so that the ranging accuracy is improved.
Further, since the ceramic material is opaque, there is an advantage that the crosstalk of the imaging light beam can be prevented without separately providing a light shielding member as in the second embodiment.
In the present embodiment, the compound eye camera apparatus provided with two imaging lenses and two imaging elements has been described as an example. However, this is merely an example, and two or more imaging lenses and imaging elements are provided. It is also applicable to a compound eye camera device.

  DESCRIPTION OF SYMBOLS 11 Imaging lens array, 11a 11b Imaging lens, 12 Aperture, 13 Spacer, 14 Solid-state image sensor, 14a 14b Imaging area, 15 Cover glass, 16 Image sensor board | substrate, 17 Electrode pad, 18 BGA, 20 Underfill agent

JP 09-318867 A JP 2007-322128 A

Claims (10)

An imaging lens array comprising a plurality of imaging lenses;
A plurality of imaging regions are formed on the semiconductor wafer, and an imaging element array that receives the imaging light flux emitted from each imaging lens in each of the imaging regions, and
An interval holding member that holds an interval between the imaging lens and the imaging region,
The compound eye camera device, wherein an imaging region surface side of the imaging element array is directly connected to one of the interval holding members, and an emission surface side of the imaging lens array is directly connected to the other of the interval holding members.   2. The compound eye camera according to claim 1, wherein a linear expansion coefficient value of the spacing member is within a range between a linear expansion coefficient value of the imaging element array and a linear expansion coefficient value of the imaging lens array. apparatus.   The compound-eye camera device according to claim 1, wherein the imaging element array includes a protection member that protects a surface of the imaging region.   The compound-eye camera device according to any one of claims 1 to 3, wherein the imaging lens array is made of an optical glass material.   The compound eye camera device according to claim 1, wherein the spacing member is made of a glass material.   The compound eye camera device according to claim 1, wherein the spacing member is made of a ceramic material.   The through-hole is formed in the optical path between the imaging lens and the imaging region, and the interval holding member includes a light shielding member on an inner wall surface of the through-hole. The compound eye camera apparatus as described in any one of 6.   The compound-eye camera device according to claim 1, further comprising a light shielding member that makes the effective diameters of the plurality of imaging lenses substantially equal.   9. A distance measuring device comprising: the compound eye camera device according to claim 1; and a calculation unit that calculates a distance from an output signal of the compound eye camera device. Preparing an imaging element array in which a plurality of imaging regions are formed on a single semiconductor wafer and a protective member is formed on the upper surface of the imaging region;
Bonding a spacing member to the upper surface of the protective member;
Bonding an imaging lens array in which a plurality of imaging lenses are formed on a single lens material on the upper surface of the spacing member;
The manufacturing method of the compound eye camera apparatus characterized by including.

Images