JP2016018798A - Method of manufacturing imaging device, and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an imaging device capable of easily keeping a spacing uniform between a light-shielding layer and a light receiving element.SOLUTION: Provided is a method of manufacturing an imaging device that comprises: a first substrate 10 comprising a light receiving element 13; a second substrate 40 comprising a light-shielding layer 42 provided with an opening; a light transmissive part 30 arranged in a predetermined region between the first substrate and the second substrate, and that transmits light via the opening. A step of forming the light transmissive part includes: a first step of performing a first surface treatment to periphery of the predetermined region of at least one of the first substrate and the second substrate so that a predetermined droplet makes a first contact angle; a second step of performing a second surface treatment to inside of the periphery of the predetermined region so that the predetermined droplet makes a second contact angle smaller than the first contact angle; and a third step of discharging a droplet with light transmissivity onto the predetermined region subjected to the first surface treatment and the second surface treatment.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an imaging device manufacturing method and an imaging device.

  Various techniques for capturing a vein image of a living body for biometric authentication have been proposed. For example, there is a finger authentication device in which a light source unit and an imaging unit are arranged so as to face each other with a subject (a finger of the person to be authenticated) interposed therebetween, and the imaging device captures light emitted from the light source unit and transmitted through the subject. It is disclosed. As a structure for realizing this type of imaging device, for example, as described in Patent Document 1, a pinhole (light transmission region) is interposed between the microlens and the light receiving element, and the microlens There has been known a downsized imaging device by arranging a plurality of light receiving elements and pinholes in a one-to-one correspondence. In the imaging apparatus described above, it is necessary to dispose the light shielding layer and the light receiving element so as to face each other at an appropriate interval in order to allow the inspection light to selectively enter the light receiving element. Specifically, when the distance between the light shielding layer and the light receiving element is set to be equal to or larger than the arrangement pitch of the light receiving elements, the inspection light can selectively enter the light receiving element.

  A spacer may be used to secure the above-mentioned distance. As an example, a spacer of about several μm to 20 μm is used in a liquid crystal panel or the like. Patent Document 2 discloses that a spacer having a maximum size of 50 μm is used. Moreover, as a technique for maintaining an appropriate interval, for example, Patent Document 3 discloses a technique for forming a resin layer in an area surrounded by a partition wall by an ink jet method.

Japanese Patent Laid-Open No. 5-100186 JP 2013-164494 A JP 2002-148429 A

  However, although the arrangement pitch of the light receiving elements is set to 50 μm to 100 μm or more, in the configuration described in Patent Document 2, since a spacer with a maximum of 50 μm is used, a technique using the spacer cannot be applied. The configuration described in Patent Document 2 also has a problem that it is difficult to match the refractive index between the spacer and the solvent. In addition, when the partition is used to appropriately maintain the distance between the light shielding layer and the light receiving element, it is difficult to form the resin layer without overflowing the partition, and the height of the region adjacent to the overflowed resin layer is difficult. It is difficult to maintain a uniform thickness when viewed as an entire layer.

  The present invention has been made in consideration of the above points, and can provide an imaging device manufacturing method and an imaging device capable of easily and uniformly holding the interval between the light shielding layer and the light receiving element. .

  One manufacturing method of an imaging device according to the present invention includes a first substrate including a light receiving element, a second substrate including a light-shielding layer provided with an opening, and between the first substrate and the second substrate. An imaging apparatus manufacturing method comprising: a light-transmitting portion that is disposed in a predetermined region and transmits light through the opening; and the step of forming the light-transmitting portion includes the first substrate and the second substrate. A first step of performing a first surface treatment in which a predetermined droplet has a first contact angle at an edge portion of the predetermined region in at least one of the predetermined region, and the predetermined droplet on the inner side of the edge portion in the predetermined region A second step of performing a second surface treatment having a second contact angle smaller than the first contact angle; and a droplet having translucency in the first surface treatment and the predetermined region subjected to the second surface treatment. And a third step of discharging.

  According to this configuration, the predetermined liquid droplets discharged to the edge in the predetermined area have the first contact angle that is held at the edge by the first surface treatment, so that the discharged liquid droplets are in the predetermined area. It is possible to suppress wetting and spreading outside. Further, according to the above configuration, the predetermined liquid droplets discharged to the inner side of the edge in the predetermined region are discharged by setting the second contact angle to be a second contact angle smaller than the first contact angle by the second surface treatment. Since the liquid droplets wet and spread inside the edge of the predetermined region, it is possible to form a light-transmitting portion having a predetermined thickness without forming large irregularities. Therefore, according to the above configuration, the distance between the first substrate and the second substrate, that is, the distance between the light shielding layer and the light receiving element, can be easily maintained uniformly.

  In the manufacturing method of one image pickup apparatus, the third step includes a fourth step of discharging the light-transmitting liquid droplets to form a pedestal portion having a predetermined thickness, and a step on the pedestal portion. It is preferable that the method includes a fifth step of discharging the light-transmitting liquid droplets to form an adjustment portion thinner than the predetermined thickness.

  According to this configuration, even when large unevenness is generated on the surface when the pedestal portion is formed, the adjustment portion is formed on the pedestal portion by forming the adjustment portion that is thinner than the pedestal portion. When forming, it becomes possible to fill the unevenness and planarize. In addition, according to this configuration, when the first substrate and the second substrate are aligned (aligned), the liquid substrate adjusting unit is interposed so that the first substrate and the second substrate can be easily aligned. can do.

In the one method for manufacturing an imaging device, it is preferable that the third step further includes a sixth step of curing the pedestal portion before the fifth step.
According to this configuration, even when droplets are ejected onto the pedestal portion when forming the adjustment portion, it is possible to suppress the formation of new irregularities on the surface of the pedestal portion, and the thickness of the pedestal portion varies Therefore, the thickness of the translucent part can be adjusted with high accuracy according to the thickness of the adjusting part.

It is preferable that the manufacturing method of one imaging apparatus includes a seventh step of setting the second substrate on the adjustment unit and curing the adjustment unit.
According to this configuration, it is possible to maintain the relative positional relationship between the first substrate and the second substrate after aligning the first substrate and the second substrate with the adjustment unit interposed therebetween. Become.

  In the manufacturing method of one imaging apparatus, it is preferable that the first contact angle is 35 ° or more and the second contact angle is 10 ° or less. According to this configuration, if the first contact angle is less than 35 °, it becomes difficult to hold the discharged liquid droplet at the edge, or if the second contact angle exceeds 10 °, the droplet is discharged inside the edge. It is possible to prevent the formed droplets from being partially connected or uneven.

  In the manufacturing method of one image pickup apparatus described above, it is preferable that the translucent part fixes the first substrate and the second substrate as an adhesive. According to this configuration, the interval between the light shielding layer and the light receiving element can be kept uniform.

  One imaging apparatus according to the present invention includes a first substrate including a light receiving element, a second substrate including a light shielding layer provided with an opening, and a predetermined region between the first substrate and the second substrate. A translucent part that transmits light through the opening, and the translucent part is between the first layer on the first substrate side, and between the first layer and the second substrate. The first layer is thicker than the second layer, and the refractive index of the first layer and the refractive index of the second layer are the same. It is characterized by.

  According to this configuration, after the first layer is formed on the first substrate side, the second layer having a smaller thickness than the first layer is formed, thereby having a constant refractive index with a predetermined thickness. Since the light transmitting portion can be formed, the distance between the first substrate and the second substrate, that is, the distance between the light shielding layer and the light receiving element can be easily maintained uniformly.

1 is an exploded perspective view of an imaging apparatus according to the present embodiment. FIG. 2 is a cross-sectional view taken along line A-A ′ of FIG. 1. 6 is a flowchart showing a method for manufacturing the imaging apparatus according to the present embodiment. The top view which showed typically the sensor substrate 10 in which the translucent member 30 is formed. FIG. 2 is a cross-sectional view taken along line A-A ′ of FIG. 1 for each main process. Schematic which shows the structure of an inspection apparatus.

  Hereinafter, an imaging device manufacturing method and an imaging device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6. FIG. 1 is an exploded perspective view of an imaging apparatus 2 to which the manufacturing method according to the present invention is applied. FIG. 2 is a cross-sectional view of the imaging apparatus along the line A-A ′ of FIG. 1. First, a schematic configuration of the imaging apparatus 2 according to the present embodiment will be described with reference to FIGS. 1 and 2.

  The embodiment described below shows one aspect of the present invention, does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each configuration easy to understand, the actual structure is different from the scale and number of each structure.

  The imaging device 2 according to the present embodiment is an image sensor that irradiates an irradiated body (not shown) with light and converts reflected light from the irradiated body into an electrical signal. The imaging apparatus 2 includes a light emitting element 52 that illuminates an irradiated body, a sensing device in which a photodiode 13 as a photoelectric conversion element (light receiving element) that detects light (inspection light) reflected from the irradiated body is disposed. It has area 5. The shape of the sensing region 5 is a square, and is illustrated by a broken line in FIGS.

  In the following description, the direction along one side of the sensing region 5 close to the terminal 14 is the X axis direction, and the directions along the other two sides that are orthogonal to the one side and face each other are the Y axis direction, the X axis direction, and A description will be given assuming that the thickness direction of the imaging device 2 is orthogonal to the Y-axis direction and the Z-axis direction.

  As shown in FIGS. 1 and 2, the imaging apparatus 2 includes a sensor substrate (first substrate) 10, a translucent member (translucent portion) 30, and a light shielding substrate (second substrate) in the Z-axis (+) direction. 40, an illumination substrate 50, and a microlens array (hereinafter referred to as MLA) substrate 60 are laminated in this order. The light shielding substrate 40 and the illumination substrate 50, and the illumination substrate 50 and the MLA substrate 60 are bonded to each other by a transparent adhesive 63 (see FIG. 2).

  The sensor substrate 10 has a role of converting reflected light from the irradiated body into an electrical signal. The sensor substrate 10 includes a sensor substrate main body 11, a photodiode 13 formed on the Z-axis (+) direction side surface of the sensor substrate main body 11, a circuit unit 12, a terminal 14, and the like. The sensor substrate body 11 may be an insulating substrate, and glass, quartz, resin, ceramic, or the like can be used. The photodiode 13 is composed of, for example, a photoelectric conversion element having a PIN type semiconductor layer as a photoelectric conversion layer, and can detect light in the near infrared region. In the sensing region 5, the photodiodes 13 are arranged at equal intervals in the X direction and the Y direction, and the interval (arrangement pitch) is approximately 100 μm. The circuit unit 12 is configured by a complementary transistor including, for example, an n-channel transistor and a P-channel transistor. The terminal 14 is connected to an external circuit (not shown) and supplies a control signal from the external circuit to the circuit unit 12.

  The light shielding substrate 40 includes a light shielding substrate body 41 and a light shielding film (light shielding layer) 42 disposed on the surface of the light shielding substrate body 41 on the Z-axis (−) direction side. The light shielding substrate body 41 is a translucent substrate, and glass, quartz, resin, or the like can be used. The light shielding film 42 may be a film having a light shielding property, and for example, a metal film such as Cr can be used. An opening 43 is formed in the light shielding film 42 at a position corresponding to the photodiode 13. The inspection light reflected from the irradiated body passes through the opening 43 and the translucent member 30 and enters the photodiode 13.

  The translucent member (translucent portion) 30 forms a predetermined interval between the sensor substrate 10 and the light shielding substrate 40. The translucent member 30 functions as an adhesive that fixes the sensor substrate 10 and the light shielding substrate 40 together. The translucent member 30 includes a pedestal part (first layer) 31 and an adjustment part (second layer) 35, both of which have translucency. The translucent member 30 is disposed between the sensor substrate 10 and the light-shielding substrate 40. The arrangement region (predetermined region) MA that covers the sensing region 5 and the circuit unit 12 and does not cover the terminals 14 (FIG. 2, FIG. 3).

  The pedestal portion 31 is disposed on the sensor substrate 10 side, and the thickness (length in the Z-axis direction) of the pedestal portion 31 is 80 μm as an example. The pedestal portion 31 has a role of protecting the photodiode 13 disposed in the sensing region 5 of the sensor substrate 10 from mechanical shock. The adjustment unit 35 is disposed on the light shielding substrate 40 side (between the pedestal unit 31 and the light shielding substrate 40), and the thickness of the adjustment unit 35 is, for example, 20 μm. As described above, since the light-transmitting member 30 having a thickness of 100 μm is disposed (filled) in the sensing region 5 between the sensor substrate 10 and the light shielding substrate 40, the sensor substrate 10 and the light shielding substrate in the sensing region 5 are arranged. 40 can be arranged at a uniform interval (approximately 100 μm). In addition, the structure which arrange | positions the base part 31 in the light shielding board | substrate 40 side, and arrange | positions the adjustment part 35 in the sensor board | substrate 10 side may be sufficient.

  As described above, the translucent member 30 is disposed between the sensor substrate 10 and the light shielding substrate 40, and the inspection light that has passed through the opening 43 passes through the translucent member 30 and enters the photodiode 13. It is supposed to be. The refractive index of the translucent member 30 is substantially equal to the refractive index of the light shielding substrate body 41. As a result, the interface reflection at the boundary between the light shielding substrate main body 41 and the translucent member 30 in the opening 43 is suppressed, so that the attenuation of the inspection light can be suppressed.

  The illumination board 50 includes an illumination board body 51, a light emitting element 52 formed on the surface of the illumination board body 51 on the Z-axis (+) direction side, and the like. The light emitting element 52 is an organic electroluminescence element that emits near-infrared light in the Z-axis (+) direction, and includes an anode (not shown), a light emitting function layer (not shown), and a cathode (not shown). ing. The light emitting elements 52 are arranged in a matrix in the sensing region 5 so as to illuminate the irradiated object uniformly.

  The MLA substrate 60 is an example of a “condensing substrate”, and has a role of condensing the light to be inspected reflected from the irradiated body and guiding it to the photodiode 13. The MLA substrate 60 includes an MLA substrate main body 61, a microlens 62 formed on the surface of the MLA substrate main body 61 on the Z-axis (−) direction side, and the like. The MLA substrate body 61 is a translucent substrate, and glass, quartz, resin, or the like can be used. The microlens 62 is a spherical lens or an aspherical lens formed of transparent resin or glass, and is arranged in a matrix in the sensing region 5. The microlens 62 can be formed using a reflow method, an area gradation mask method, a microlens method, a molding method, or the like.

“Overview of Sensing Area”
Next, an outline of the sensing area 5 (inspection light detection method and the like) will be described. In the sensing region 5, the photodiodes 13, the openings 43, the light emitting elements 52, the microlenses 62, and the like are arranged in a matrix and correspond to each other one to one. 1 and 2 is an imaginary line that connects the center of one of the plurality of microlenses 62 and the center of the opening 43, and is parallel to the Z-axis direction. It has become. In FIG. 2, an arrow with a reference numeral 7 indicates inspection light (hereinafter referred to as inspection light 7) incident on one of the photodiodes 13 arranged in a plurality. Note that the photodiode 13 corresponds to the microlens 62. An arrow labeled 8 indicates light traveling on the optical path connecting the adjacent microlens 62 and the photodiode 13, that is, other than the inspection light 7 traveling from the adjacent microlens 62 toward the photodiode 13. Light (hereinafter referred to as unnecessary light 8).

  The microlens 62, the opening 43, and the photodiode 13 are disposed on the optical axis 6. The light emitting element 52 is disposed at a position away from the optical axis 6. As a result, the inspection light 7 collected by the microlens 62 is not shielded by the light emitting element 52. Further, a region intersecting with the optical axis 6 of the illumination substrate 50 (a region through which the inspection light 7 passes) has translucency, and the inspection light 7 passes (transmits) through the illumination substrate 50. Yes.

  As shown in FIG. 2, the light condensed by the microlens 62 and traveling along the optical axis 6 becomes the inspection light 7. That is, the inspection light 7 passes through the microlens 62 of the MLA substrate 60, the translucent region of the illumination substrate 50, the opening 43 of the light shielding substrate 40, and the translucent member 30, and enters the photodiode 13 of the sensor substrate 10. Incident. In other words, light incident on the microlens 62 from directly above the microlens 62 (Z-axis direction) travels along the optical axis 6 and enters the photodiode 13. That is, in the sensing area 5, it is possible to capture the image information of the subject that enters the microlens 62 from the Z-axis direction.

  The microlens 62 is a so-called convex lens, and the light (image information of the subject) collected by the microlens 62 forms an image on the light receiving surface of the photodiode 13. Further, the light shielding substrate 40 is disposed approximately 100 μm away from the sensor substrate 10 by the translucent member 30. The distance between the light shielding substrate 40 and the sensor substrate 10 is equal to the arrangement pitch (approximately 100 μm) of the photodiodes 13 arranged in the sensing region 5 of the sensor substrate 10. With the sensor substrate 10 and the light-shielding substrate 40 facing each other at an interval of approximately 100 μm, the opening size of the opening 43 is the smallest size that allows the inspection light 7 collected by the microlens 62 to pass through the opening 43. Has been processed. As a result, unnecessary light 8 inserted from the adjacent microlenses 62 is reflected (light-shielded) by the light-shielding film 42 of the light-shielding substrate 40, and the incidence on the photodiode 13 is suppressed. In addition to the unnecessary light 8, light other than the inspection light 7 exists. All of the light other than the inspection light 7 travels in an oblique direction with respect to the optical axis 6 and is shielded from light by the light shielding film 42 of the light shielding substrate 40 and is prevented from entering the photodiode 13. Since light other than the inspection light 7 becomes detection noise of the photodiode 13, high-precision image information with small detection noise can be captured by the photodiode 13 by shielding light other than the inspection light 7.

  As described above, in order to shield the unnecessary light 8 and selectively allow the inspection light 7 to enter the photodiode 13, the light shielding substrate 40 and the sensor substrate 10 are parallel to each other at an interval equal to or larger than the arrangement pitch of the photodiodes 13. It is important to place in When a region in which the light shielding substrate 40 is disposed obliquely with respect to the sensor substrate 10 is generated due to warpage of the substrate, the photodiode 13 is not disposed on the optical axis 6 in the region, and the inspection light 7 is not incident. This problem occurs. In order to avoid such a problem, it is preferable to form the gap between the light shielding substrate 40 and the sensor substrate 10 with an accuracy of ± 5% or less. In the present embodiment, the arrangement pitch of the photodiodes 13 is approximately 100 μm, and the light shielding substrate 40 and the sensor substrate 10 are arranged in parallel at a uniform interval of approximately 100 μm. Since the present invention has a suitable manufacturing method for arranging the light shielding substrate 40 and the sensor substrate 10 at a uniform interval, an outline thereof will be described below.

"Outline of manufacturing method that arranges light-shielding substrate and sensor substrate at uniform intervals"
FIG. 3 is a flowchart showing a method of manufacturing the translucent member 30 in which the light shielding substrate 40 and the sensor substrate 10 are arranged at a uniform interval in the order of steps. FIG. 4 is a plan view schematically showing the sensor substrate 10 on which the translucent member 30 is formed. FIG. 5 is a cross-sectional view of each main process along the line AA ′ in FIG. In FIG. 5, the sensing region 5 is indicated by a broken line so that the positions of the components formed in each process can be seen. Hereinafter, the outline of the manufacturing method according to the present embodiment will be described with reference to FIGS. 3 to 5.

  In the step S1 (FIG. 3), as shown in FIG. 4A, the first surface is formed on the edge portion MA1 in the arrangement region MA of the sensor substrate body 11 of the sensor substrate 10 on which the translucent member 30 is formed. Process. The first surface treatment is a treatment in which the droplets of the light transmissive material constituting the light transmissive member 30 become the first contact angle. Specifically, the first surface treatment is a treatment for suppressing the wetting and spreading of the droplet (providing liquid repellency) when the first contact angle of the droplet is 35 ° or more. As an example of the first surface treatment, a method of forming a self-assembled film made of an organic molecular film or the like on the surface of the sensor substrate body 11 can be employed.

  The organic molecular film has a functional group that can bind to the sensor substrate body 11 and a functional group that modifies the surface properties of the sensor substrate body 11 such as a lyophilic group or a liquid repellent group on the opposite side (controls the surface energy). And a linear or partially branched carbon chain that connects these functional groups, and binds to the sensor substrate body 11 to self-assemble to form a molecular film, for example, a monomolecular film. The self-assembled film is composed of a binding functional group capable of reacting with constituent atoms such as the underlying layer of the sensor substrate body 11 and other linear molecules, and has extremely high orientation due to the interaction of the linear molecules. It is a film formed by orienting a compound. Since this self-assembled film is formed by orienting single molecules, the film thickness can be extremely reduced, and the film is uniform at the molecular level. That is, since the same molecule is located on the surface of the film, uniform and excellent liquid repellency and lyophilicity can be imparted to the surface of the film. By using, for example, fluoroalkylsilane (FAS) as the compound having high orientation, each compound is oriented so that the fluoroalkyl group is located on the surface of the film, and a self-assembled film is formed. Uniform liquid repellency is imparted to the surface.

  Moreover, the process which processes the surface of the sensor substrate main body 11 to liquid repellency sticks the film which has desired liquid repellency, for example, the polyimide film etc. which were processed with tetrafluoroethylene, to the surface of the sensor substrate main body 11 May also be performed.

  In step S2 (FIG. 3), the second surface treatment is performed on the inner side MA2 of the arrangement area MA from the edge MA1. The second surface treatment is a treatment in which the translucent material droplets constituting the translucent member 30 become the second contact angle. Specifically, the second surface treatment is performed so that the second contact angle of the droplet is 10 ° or less, which is smaller than the first contact angle, to improve the wettability of the droplet (providing lyophilicity). It is processing. As an example of the second surface treatment, an ashing treatment can be given. As the ashing treatment, photo-excited ashing that irradiates light such as ultraviolet rays in an ashing chamber into which gas such as ozone is introduced, plasma ashing that converts oxygen gas or the like into plasma at a high frequency and peels off foreign matters using the plasma, etc. You can choose. In the case of performing the second surface treatment, the edge portion MA1 subjected to the first surface treatment in step S1 is masked so that the influence of the second surface treatment does not reach the wettability.

  If the first contact angle of the edge portion MA1 is 35 ° or more in the pre-processing for the sensor substrate main body 11 (processing for forming the photolitho and the like, the circuit portion 12 and the terminal 14 and the like), the step You may abbreviate | omit the 1st surface treatment process of S1. In this case, as shown in FIG.4 (b), what is necessary is just to mask the whole outer side rather than inner side part MA2 containing edge part MA1.

  In the step S3 (FIG. 3), as shown in FIG. 5 (a), a droplet 32 of translucent resin as a translucent material (on the translucent material MA in the sensor substrate body 11 of the sensor substrate 10 is provided by a dispenser. In the following description, the translucent resin 32 is discharged (applied) to form the pedestal precursor 33 as shown in FIG. As the translucent resin 32, either a photocurable resin or a thermosetting resin can be used. However, since the resin can be quickly cured and the photodiode 13 is affected by heat, the photocurable resin 32 is used. As an example, it is preferable to use a UV curable resin. As an example, the translucent resin 32 of the present embodiment is formed of a UV curable epoxy resin having a viscosity of approximately 500 cP (mPa · s).

  Of the translucent resin 32 ejected on the surface of the sensor substrate body 11, the translucent resin 32 ejected to the edge MA1 spreads wet because the edge MA1 has liquid repellency. Is suppressed and held at the edge MA1. On the other hand, among the translucent resins 32 ejected to the surface of the sensor substrate body 11, the translucent resin 32 ejected to the inner part MA2 has an inner part MA2 because the inner part MA2 is lyophilic. Wet and spread with MA2.

  FIG. 5A shows a state immediately after the application of the translucent resin 32. As shown in FIG. 5A, immediately after the application of the translucent resin 32, a plurality of translucent resins 32 applied and formed in a line along the X-axis direction are arranged in the Y-axis direction. A precursor 33 is formed. For this reason, the surface (surface on the Z-axis (+) direction side) of the base precursor 33 has irregularities, and the thickness (length in the Z-axis direction) changes periodically.

  In the step S4 (FIG. 3), the applied translucent resin 32 is allowed to stand for a certain period of time, the translucent resin 32 is allowed to flow, and leveling is performed to make the pedestal precursor 33 uniform in thickness. The thickness of the base precursor 33 depends on the application amount of the translucent resin 32. In the step of curing the translucent resin 32 described later, the translucent resin 32 shrinks in volume. In consideration of this volume shrinkage, the pedestal precursor 33 is formed so as to be thicker than the thickness of the pedestal portion 31 (approximately 80 μm). Specifically, the thickness of the pedestal precursor 33 is, for example, 84 μm.

  FIG. 5B shows the state of the pedestal precursor 33 after being leveled. In step S4, the translucent resin 32 flows so that the surface area of the base precursor 33 is minimized by the surface tension and the own weight of the translucent resin 32. As a result, the surface unevenness of the pedestal precursor 33 is reduced, and the pedestal precursor 33 forms a smooth (flat) surface. The pedestal precursor 33 has a uniform thickness after leveling.

  In step S5 (FIG. 3), the base precursor 33 is irradiated with UV light, the translucent resin 32 is cured (solidified), and the base 31 is formed. As a result, the pedestal precursor 33 having the shape shown in FIG. As shown in FIG. 5B, the pedestal portion 31 has a trapezoidal cross section in which the side on the side in contact with the sensor substrate 10 is long. Moreover, the edge part of the base part 31 is a taper shape inclined with respect to the Z-axis (+) direction. The pedestal precursor 33 shrinks in volume at the time of curing with UV light, and the thickness of the pedestal portion 31 is, for example, 80 μm.

  As described above, the resin material forming the pedestal precursor 33 may be either a thermosetting resin or a resin having thermosetting and photocuring properties. Even in the case of using these resins, the same leveling treatment is performed, and the surface is made to flow so that the surface area is minimized by the surface tension and the own weight of the resin, thereby providing a pedestal having a smooth (flat) surface. The precursor 33 can be formed. Even in the case of using either a thermosetting resin or a resin having thermosetting and photocuring properties, the same volume shrinkage occurs at the time of curing, so that the thickness of the pedestal portion 31 has a predetermined dimension ( It is necessary to form the pedestal precursor 33 in anticipation of volume shrinkage so as to be approximately 80 μm).

  In step S6 (FIG. 3), the thermosetting translucent resin 36 is applied to the surface of the pedestal 31 (the surface on the light shielding substrate 40 side) by a dispenser. The translucent resin 36 is an example of a “translucent resin material”. As an example, the viscosity of the translucent resin 36 is approximately 300 cP (mPa · s). FIG. 5C is a diagram showing a state after application of the translucent resin 36. Since the translucent resin 36 has a low viscosity (approximately 300 cP), the translucent resin 36 flows (wet and spread) on the surface of the pedestal 31 by the surface tension and the own weight of the translucent resin 36. As a result, as shown in FIG. 5C, the translucent resin 36 is formed so as to cover the surface of the pedestal portion 31. The application amount (drop amount) of the translucent resin 36 will be described later.

  In step S7 (FIG. 3), the light shielding substrate 40 is overlaid (bonded) at a predetermined position on the sensor substrate 10 and pressed, and the distance between the light shielding substrate 40 and the sensor substrate 10 (the thickness of the translucent resin 36). Is approximately 22 μm. These steps are performed in a reduced pressure atmosphere. When the light shielding substrate 40 and the sensor substrate 10 are pressed, the translucent resin 36 protrudes from between the light shielding substrate 40 and the pedestal portion 31. When the translucent resin 36 protruding from between the light shielding substrate 40 and the pedestal 31 reaches the terminal 14, it becomes difficult to make an electrical connection with an external circuit (not shown). For this reason, it is necessary to adjust the application amount of the translucent resin 36 in the process of step S6 so as not to protrude to the terminals 14. By carrying out the step S6 in a reduced-pressure atmosphere, air bubbles can be prevented from being mixed into the thermosetting resin 36. Further, if the thermosetting resin 36 that has been sufficiently degassed is used, the step S6 may be performed in the atmospheric pressure.

  In step S8 (FIG. 3), heat treatment is performed to cure (solidify) the translucent resin 36, and the translucent adjusting unit 35 is formed between the pedestal 31 and the light shielding substrate 40. The refractive index of the adjusting unit 35 and the refractive index of the pedestal unit 31 are substantially equal to the refractive index of the light shielding substrate body 41. For this reason, interface reflection based on a difference in refractive index can be suppressed at the boundary (interface) between the light shielding substrate body 41 and the adjustment unit 35 and at the boundary between the adjustment unit 35 and the pedestal unit 31.

  As described above, volume shrinkage occurs during the solidification (curing) process of the translucent resin 36, so that the thermosetting resin 36 having a thickness of approximately 22 μm becomes the adjusting unit 35 having a thickness of approximately 20 μm. FIG. 5D is a diagram illustrating a state after the process of step S8 is performed. The adjustment unit 35 is formed between the light shielding substrate 40 and the pedestal portion 31 so as to cover the pedestal portion 31. The thickness of the translucent member 30 is approximately 100 μm. An interval (approximately 100 μm) between the light shielding substrate 40 and the sensor substrate 10 is formed by a pedestal portion 31 having a thickness of approximately 80 μm and an adjusting portion 35 having a thickness of approximately 20 μm.

  As described above, in the present embodiment, the wettability of the edge portion MA1 of the placement region MA is low and the wettability of the inside portion MA2 is high, so that the translucent resin 32 discharged to the placement region MA is edged. It is possible to easily suppress that the required thickness cannot be secured due to protruding from the portion MA1, and the translucent resin 32 discharged to the inner portion MA2 can be wetted and spread, and the droplets are not connected. It can prevent easily that an unevenness | corrugation arises. Therefore, in the present embodiment, even when the gap of about 100 μm is formed, the translucent member 30 can be formed with the required uniform thickness, and the gap between the sensor substrate 10 and the light shielding substrate 40 can be easily made. It is possible to keep it uniform. In particular, in the present embodiment, the first contact angle at the edge portion MA1 is set to 35 ° or more, and the second contact angle at the inside portion MA2 is set to 10 ° or less, so that a droplet protrudes from the edge portion MA1 or the inner portion. It is possible to surely avoid the occurrence of a problem that the droplets discharged to MA2 are not sufficiently wetted and spread.

  Further, in the present embodiment, since the translucent member 30 is formed by forming the adjustment portion 35 after the pedestal portion 31 is formed, when the sensor substrate 10 and the light shielding substrate 40 are aligned, Position adjustment can be performed using the adjustment section 35 having a small thickness, and workability can be improved. In particular, in this embodiment, since the adjustment part 35 is formed after hardening the base part 31, alignment adjustment can be performed in the state where the base was stabilized. Moreover, in this embodiment, since the translucent member 30 functions as an adhesive and can fix the sensor substrate 10 and the light-shielding substrate 40, it is not necessary to use an adhesive separately, which can contribute to cost reduction and work efficiency. .

[Inspection equipment]
Next, an example of an inspection apparatus in which the imaging apparatus according to the above-described embodiment is mounted will be described. FIG. 6 is a schematic diagram showing the configuration of the inspection apparatus.

  The inspection apparatus 100 is a biometric authentication apparatus that captures a vein image of the finger F and performs personal authentication. As illustrated in FIG. 6, the inspection apparatus 100 includes a detection unit 110, a storage unit 140, a control unit 150, an output unit 160, and the like.

  The detection unit 110 is the imaging device 2 according to the embodiment, and can irradiate the finger F with the irradiation light IL from the light emitting unit 120 and detect the reflected light RL from the finger F. The detection unit 110 includes a light emitting unit 120 (illumination substrate 50, see FIG. 1), an MLA substrate 60 (not shown), a light shielding substrate 40 (not shown), a light receiving unit 130 (sensor substrate 10, see FIG. 1), and the like. doing. The irradiation light IL is near-infrared light emitted from the light emitting unit 120, and has a wavelength of, for example, 750 to 3000 nm (more preferably 800 to 900 nm). When the irradiation light IL reaches the inside of the finger F, it is scattered, and a part thereof is directed to the light receiving unit 130 as reflected light RL.

  The light receiving unit 130 is provided with a photodiode 13 that detects light in the near infrared region. Reduced hemoglobin flowing through the vein has the property of absorbing light in the near infrared region. For this reason, when the finger F is imaged using the photodiode 13 that detects light in the near infrared region, the vein portion under the finger F appears darker than the surrounding tissue. The pattern due to this difference in brightness becomes a vein image. The reflected light RL from the finger F is converted by the light receiving unit 130 into an electric signal (light receiving signal) having a signal level corresponding to the amount of light.

  The storage unit 140 is a non-volatile memory such as a flash memory or a hard disk, and stores a vein image of a finger F registered in advance (for example, the index finger of the right hand) as a master vein image for personal authentication.

  The control unit 150 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), and the like, and controls turning on and off of the light emitting unit 120. In addition, the control unit 150 reads the light reception signal from the light reception unit 130 and generates a vein image of the finger F based on the read light reception signal for one frame (for the imaging region). Furthermore, the control unit 150 collates the generated vein image with the master vein image registered in the storage unit 140, and performs personal authentication.

  The output unit 160 is, for example, a display unit or a voice notification unit, and notifies the authentication result by display or voice.

  With the above configuration, the inspection apparatus 100 can capture the vein image of the finger F with high accuracy and perform personal authentication.

  The part of the living body that is the target of vein authentication may be the palm, the back of the hand, the eye, or the like. The detection unit 110 described above can be applied to a small biosensor that can be always worn in the medical and health fields. Furthermore, as an inspection apparatus equipped with the detection unit 110, for example, a pulse meter, a pulse oximeter, a blood glucose level measuring device, a fruit sugar content meter, etc. in fields such as medical care and health can be provided. Further, the detection unit 110 can provide a personal computer or a mobile phone having a biometric authentication function.

  The detection unit 110 can also be applied to an image reading apparatus such as an image scanner, a copying machine, a facsimile, or a barcode reader. When applied to an image reading apparatus, it is preferable to use visible light instead of near-infrared light as the irradiation light IL and the reflected light RL.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the said embodiment, although the translucent member 30 demonstrated as what was comprised by the two layers of the base part 31 and the adjustment part 35, it is not limited to this, You may comprise by one layer. . Moreover, in the said embodiment, although the structure in which the translucent member 30 was formed on the sensor board | substrate 10 was illustrated, the structure formed on the light shielding board | substrate 40 may be sufficient. Further, a part of the translucent member 30 (for example, the pedestal 31) is formed on the sensor substrate 10 and the other part (for example, the adjustment unit 35) is formed on the light shielding substrate 40. Good.

  In addition, the first surface treatment method and the second surface treatment method shown in the above embodiment are merely examples, and other methods are adopted if the contact angle of the light-transmitting material with respect to the droplets falls within the above range. May be.

  DESCRIPTION OF SYMBOLS 2 ... Imaging device, 10 ... Sensor board | substrate (1st board | substrate), 13 ... Photodiode (light receiving element, photoelectric conversion element), 30 ... Translucent member (translucent part), 31 ... Pedestal part (1st layer) 35 ... adjustment unit (second layer), 40 ... light shielding substrate (second substrate), 42 ... light shielding film (light shielding layer), 43 ... opening, MA ... arrangement region (predetermined region)

Claims (7)

A first substrate having a light receiving element; a second substrate having a light-shielding layer provided with an opening; and light passing through the opening disposed in a predetermined region between the first substrate and the second substrate. A manufacturing method of an imaging device including a light transmitting portion to transmit,
The step of forming the translucent part includes
A first step of performing a first surface treatment in which a predetermined droplet has a first contact angle at an edge of the predetermined region in at least one of the first substrate and the second substrate;
A second step of performing a second surface treatment in which the predetermined droplet has a second contact angle smaller than the first contact angle inside the edge in the predetermined region;
A third step of ejecting light-transmitting liquid droplets in the predetermined area subjected to the first surface treatment and the second surface treatment;
A method for manufacturing an imaging apparatus, comprising: The third step includes
A fourth step of discharging the light-transmitting liquid droplets to form a base portion having a predetermined thickness;
The imaging step according to claim 1, further comprising: a fifth step of forming an adjustment portion thinner than the predetermined thickness by discharging the light-transmitting liquid droplets on the pedestal portion. Device manufacturing method. The third step includes
The method for manufacturing an imaging device according to claim 2, further comprising a sixth step of curing the pedestal portion before the fifth step.   The manufacturing method of the imaging device according to claim 2, further comprising: a seventh step of installing the second substrate on the adjustment unit and curing the adjustment unit.   5. The method of manufacturing an imaging device according to claim 1, wherein the first contact angle is 35 ° or more and the second contact angle is 10 ° or less. 6.   6. The method of manufacturing an imaging apparatus according to claim 1, wherein the translucent portion fixes the first substrate and the second substrate as an adhesive. 7. A first substrate comprising a light receiving element;
A second substrate comprising a light shielding layer provided with an opening;
A translucent part that is disposed in a predetermined region between the first substrate and the second substrate and transmits light through the opening;
The transmissive portion includes a first layer on the first substrate side and a second layer between the first layer and the second substrate.
Composed of layers,
The imaging device is characterized in that the thickness of the first layer is thicker than the thickness of the second layer, and the refractive index of the first layer and the refractive index of the second layer are the same.

Images