JP2017103347A - Assembly method for substrates - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an assembly method for a plurality of substrates of highly accurately aligning the plurality of substrates and bonding them to each other.SOLUTION: An assembly method for a plurality of substrates includes a step of causing an alignment mark surface 55b of a first substrate 50 having a first alignment mark 57 formed on the alignment mark surface 55b facing a functional surface having wiring or a functional layer and an alignment mark surface 45b of a second substrate 40 having a second alignment mark 47 formed on the alignment mark surface 45b facing the functional surface having the wiring or the functional layer to face each other, checking a relative position between the first alignment mark 57 and the second alignment mark 47, and bonding the first substrate 50 the second substrate 40 to each other.SELECTED DRAWING: Figure 12

Description

  The present invention relates to a method for assembling substrates.

  Generally, as a method of assembling or joining two substrates with their functional surfaces on which wirings or functional layers are formed facing each other, as disclosed in Patent Document 1 and Patent Document 2, two substrates are used. There is known a method of aligning and assembling or joining two substrates by imaging and aligning alignment marks formed on the respective functional surfaces with a camera.

JP 2004-163598 A JP-A-7-306007

  However, the two substrates joined with the functional surfaces on which the wirings or functional layers are formed facing each other and the two substrates joined with the functional surfaces on which the wirings or functional layers are formed facing each other are positioned accurately. When attempting to assemble or join together, the alignment marks in Patent Document 1 and Patent Document 2 are respectively formed on the functional surface of the substrate. Therefore, the alignment marks are separated from each other by the thickness of the substrate, the focal length of the camera is different, and there is a problem that the substrates to which the two substrates are bonded cannot be aligned with high accuracy.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A method for assembling substrates according to this application example includes the alignment mark surface of a first substrate having a first alignment mark formed on an alignment mark surface facing a functional surface having a wiring or a functional layer. The first alignment mark and the second alignment mark are opposed to the alignment mark surface of the second substrate having the second alignment mark formed on the alignment mark surface facing the functional surface having the wiring or the functional layer. And a step of bonding the first substrate and the second substrate.

  According to this application example, since the alignment mark surface on which the first alignment mark is formed and the alignment mark surface on which the second alignment mark is formed are opposed to each other, the first alignment mark and the second alignment mark are Can be brought close together. Therefore, the first alignment mark and the second alignment mark have substantially the same focal length of the camera to be aligned, and the relative position between the first alignment mark and the second alignment mark can be accurately confirmed. There is an effect that the substrate and the second substrate can be accurately aligned and bonded.

  Application Example 2 In the method for assembling the substrates according to the application example described above, it is preferable that a third substrate is bonded to the functional surface of the first substrate.

  According to this application example, the functional surface of the first substrate can be protected by the third substrate, and the characteristics can be stabilized.

  Application Example 3 In the method for assembling the substrates described in the application example, it is preferable that a fourth substrate is bonded to the functional surface of the second substrate.

  According to this application example, the functional surface of the second substrate can be protected by the fourth substrate, and the characteristics can be stabilized.

  Application Example 4 In the method for assembling the substrates according to the application example described above, a step of forming a pattern of the wiring or the functional layer on the functional surface of the first substrate, and the alignment mark of the first substrate Forming a first alignment mark on a surface, forming a pattern of the wiring or the functional layer on the functional surface of the second substrate, and forming the pattern on the alignment mark surface of the second substrate. Forming a second alignment mark.

  According to this application example, by separating the step of forming the wiring or functional layer and the step of forming the alignment mark, corresponding to the wiring or functional layer formed on the functional surface of the first substrate and the second substrate, The first alignment mark and the second alignment mark can be formed with high positional accuracy on the alignment mark surfaces of the first substrate and the second substrate.

  Application Example 5 In the method for assembling the substrates according to the application example, the step of exposing the functional surface of the first substrate, the step of exposing the alignment mark surface of the first substrate, and the first Preferably, the method includes an etching step of etching the substrate to form the wiring or the functional layer pattern and the first alignment mark.

  According to this application example, since the wiring of the first substrate or the pattern of the functional layer and the first alignment mark can be formed at the same time, the working efficiency can be improved and the manufacturing cost can be reduced.

  Application Example 6 In the method for assembling the substrates according to the application example, the step of exposing the functional surface of the second substrate, the step of exposing the alignment mark surface of the second substrate, and the second It is preferable to include an etching step of etching the substrate to form the wiring or the functional layer pattern and the second alignment mark.

  According to this application example, since the wiring of the second substrate or the pattern of the functional layer and the second alignment mark can be formed at the same time, the working efficiency can be improved and the manufacturing cost can be reduced.

1 is an exploded perspective view illustrating a configuration of an imaging apparatus according to the present embodiment. FIG. 2 is a schematic cross-sectional view of the imaging apparatus along the line A-A ′ in FIG. 1. The flowchart which shows the assembly method of the imaging device which concerns on this embodiment to process order. The schematic plan view which shows the structure of the 1st board | substrate which concerns on this embodiment. FIG. 4B is a schematic cross-sectional view of the first substrate along the line B-B ′ in FIG. 4A. The schematic plan view which shows the structure of the 3rd board | substrate which concerns on this embodiment. FIG. 5C is a schematic cross-sectional view of the third substrate along the line C-C ′ in FIG. 5A. The schematic sectional drawing explaining alignment with a 1st board | substrate and a 3rd board | substrate. The schematic plan view which shows the state which aligned the alignment mark of the 1st board | substrate, and the alignment mark of the 3rd board | substrate. The schematic plan view which shows the structure of the 2nd board | substrate which concerns on this embodiment. FIG. 8B is a schematic cross-sectional view of the second substrate along the line D-D ′ in FIG. 8A. The schematic plan view which shows the structure of the 4th board | substrate which concerns on this embodiment. FIG. 9B is a schematic cross-sectional view of the fourth substrate along the line E-E ′ of FIG. 9A. The schematic sectional drawing explaining alignment with a 2nd board | substrate and a 4th board | substrate. The schematic plan view which shows the state which aligned the alignment mark of the 2nd board | substrate, and the alignment mark of the 4th board | substrate. The schematic sectional drawing explaining alignment with the 1st board | substrate with which the 3rd board | substrate was joined, and the 2nd board | substrate with which the 4th board | substrate was joined. The schematic plan view which shows the state which aligned the 1st alignment mark of the 1st board | substrate, and the 2nd alignment mark of the 2nd board | substrate. The schematic sectional drawing which shows the imaging device which completed the assembly.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. Note that the drawings to be used are appropriately enlarged or reduced so that the part to be described can be recognized.

  In the following embodiments, for example, when “on the substrate” is described, the substrate is disposed so as to be in contact with the substrate, or is disposed on the substrate via another component, or the substrate. It is assumed that a part is arranged so as to be in contact with each other and a part is arranged via another component.

(Embodiment)
First, as an assembling method of substrates according to the present embodiment, the imaging apparatus 1 will be described as an example and will be described with reference to FIGS. 1 and 2.
FIG. 1 is an exploded perspective view showing the configuration of the imaging apparatus according to the present embodiment. FIG. 2 is a schematic cross-sectional view of the imaging apparatus along the line AA ′ in FIG.

<Outline of imaging device>
The imaging apparatus 1 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 device 1 includes a sensing region 5 in which a light emitting element 52 that illuminates an irradiated object, a photodiode 13 as a photoelectric conversion element that detects light (inspection light) reflected from the irradiated object, and the like are arranged. Have. The shape of the sensing region 5 is a square, and is illustrated by a broken line in FIGS.
Hereinafter, 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 the Y axis direction. The thickness direction of the imaging device 1 will be described as the Z-axis direction.

  As shown in FIGS. 1 and 2, the imaging apparatus 1 has a predetermined interval between the sensor substrate 10 as the fourth substrate and the sensor substrate 10 and the light-shielding substrate 40 as the second substrate in the Z-axis (+) direction. The members to be formed (the sealing material 20 and the translucent member 30), the light shielding substrate 40, the illumination substrate 50 as the first substrate, and the condensing substrate 60 as the third substrate are laminated in this order. Further, the light shielding substrate 40 and the illumination substrate 50, and the illumination substrate 50 and the light collecting substrate 60 are bonded to each other by a transparent adhesive 63 (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 body 11, a photodiode 13 formed on the surface of the sensor substrate body 11 on the Z axis (+) direction side, 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 an n-channel transistor and a p-channel transistor, for example. 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 sealing material 20 includes a gap material (not shown) that forms a predetermined interval (approximately 100 μm) between the sensor substrate 10 and the light shielding substrate 40, and is arranged in a frame shape so as to surround the sensing region 5. With the frame-shaped sealing material 20, the sensor substrate 10 and the light shielding substrate 40 are arranged at an interval of approximately 100 μm.

The translucent member 30 is configured by a pedestal 31 and a translucent resin 35, and is disposed between the sensor substrate 10 and the light shielding substrate 40 so as to cover the sensing region 5. The pedestal 31 is disposed on the sensor substrate 10 side, and the thickness (length in the Z-axis direction) of the pedestal 31 is approximately 70 μm. The pedestal 31 has a role of protecting the photodiode 13 disposed in the sensing region 5 of the sensor substrate 10 from mechanical shock. The translucent resin 35 is disposed on the light shielding substrate 40 side (between the base 31 and the light shielding substrate 40), and the thickness of the translucent resin 35 is approximately 30 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).
Further, a gap 39 (see FIG. 2) is formed between the sealing material 20 and the translucent member 30. The gap 39 is a storage space for storing the translucent resin 35 overflowing from the pedestal 31 in the manufacturing process described later, and has a role of suppressing the translucent resin 35 from protruding to the outside of the sealing material 20. ing.
The base 31 may be disposed on the light shielding substrate 40 side, and the translucent resin 35 may be disposed on the sensor substrate 10 side.

The light shielding substrate 40 includes a light shielding substrate body 41 and a light shielding film 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, and the inspection light 7 reflected from the irradiated object passes through the opening 43 and enters the photodiode 13. .
As described above, the translucent member 30 is disposed between the sensor substrate 10 and the light shielding substrate 40, and the inspection light 7 that has passed through the opening 43 passes through the translucent member 30 to the photodiode 13. Incident. 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, 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 attenuation of the inspection light 7 can be suppressed.

  The illumination substrate 50 includes an illumination substrate body 51 and a light emitting element 52 formed on the surface of the illumination substrate body 51 on the Z-axis (+) direction side. 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 condensing substrate 60 is an example of a “condensing substrate”, and has a function of condensing the light to be inspected reflected from the irradiated body and guiding it to the photodiode 13. The condensing substrate 60 includes a condensing substrate main body 61 and a microlens 62 formed on the surface of the condensing substrate main body 61 on the Z-axis (−) direction side. The condensing substrate main 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 (such as a method for detecting the inspection light 7) 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 62a 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 the inspection light 7 incident on one of the photodiodes 13 arranged in a plurality. The photodiode 13 corresponds to the microlens 62a. The arrow labeled 8 indicates light traveling on the optical path connecting the adjacent microlens 62b and the photodiode 13, that is, other than the inspection light 7 traveling toward the photodiode 13 from the adjacent microlens 62b. Light (hereinafter referred to as unnecessary light 8).

  The microlens 62 a, the opening 43, and the photodiode 13 are disposed on the optical axis 6, and 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 micro lens 62 a is not blocked 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 a and traveling along the optical axis 6 becomes the inspection light 7. That is, the inspection light 7 passes through the microlens 62 a of the condensing 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 the photodiode 13 of the sensor substrate 10. It is made to enter. In other words, light incident on the microlens 62 a from directly above the microlens 62 a (Z-axis direction) travels along the optical axis 6 and enters the photodiode 13. That is, in the sensing region 5, it is possible to capture image information of a subject that enters the microlens 62a from the Z-axis direction.

  The microlens 62 a is a so-called convex lens, and light (image information on the subject) collected by the microlens 62 a 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 minimum size that allows the inspection light 7 collected by the microlens 62 a to pass through the opening 43. Has been processed. As a result, unnecessary light 8 inserted from the adjacent microlenses 62 b 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 be incident on the photodiode 13, the light shielding substrate 40 and the sensor substrate 10 are arranged at an interval equal to or larger than the arrangement pitch of the photodiodes 13. It is important to arrange them in parallel.
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.

<Assembly method of imaging device>
Next, an assembling method of the imaging apparatus 1 that is an assembling method of the substrates according to the present embodiment will be described with reference to FIGS.
FIG. 3 is a flowchart illustrating the assembly method of the imaging apparatus according to the present embodiment in the order of steps.
As shown in FIG. 3, the assembly method of the imaging apparatus 1 includes a first substrate / third substrate bonding step (Step 4) for bonding an illumination substrate 50 as a first substrate and a light collecting substrate 60 as a third substrate. The second substrate / fourth substrate bonding step (Step 8) for bonding the light shielding substrate 40 as the second substrate and the sensor substrate 10 as the fourth substrate, and the first substrate and the fourth substrate to which the third substrate is bonded. The first substrate and the second substrate bonding step (Step 9) for bonding the second substrate bonded to each other.

First, steps up to the first substrate / third substrate bonding step (Step 4) for bonding the illumination substrate 50 and the light collecting substrate 60 will be described with reference to FIGS. 4A to 7.
FIG. 4A is a schematic plan view showing the configuration of the first substrate according to the present embodiment. FIG. 4B is a schematic cross-sectional view of the first substrate along the line BB ′ in FIG. 4A. FIG. 5A is a schematic plan view showing the configuration of the third substrate according to the present embodiment. FIG. 5B is a schematic cross-sectional view of the third substrate taken along the line CC ′ of FIG. 5A. FIG. 6 is a schematic cross-sectional view illustrating alignment between the first substrate and the third substrate. FIG. 7 is a schematic plan view showing a state in which the alignment mark on the first substrate and the alignment mark on the third substrate are aligned.

<First Substrate Functional Pattern Formation Step (Step 1)>
In the first substrate functional pattern forming step (Step 1), as shown in FIGS. 4A and 4B, near-infrared light is emitted in the Z-axis (+) direction onto the functional surface 55a of the illumination substrate 50 as the first substrate. The sensing region 5 includes a light emitting element 52 that is a functional pattern of a wiring or a functional layer, which is composed of an anode (not shown), a light emitting functional layer (not shown), and a cathode (not shown). The photolithographic technique is used to form a matrix. Further, a frame-shaped alignment mark 56 having a central portion penetrating diagonally outward from the sensing region 5 on the functional surface 55a is formed by photolithography.

<First Alignment Mark Formation Step (Step 2)>
In the first alignment mark formation step (Step 2), a metal film such as chrome is formed on the alignment mark surface 55b facing the functional surface 55a of the illumination substrate 50, and the pair in the direction opposite to the position where the alignment mark 56 is formed. A frame-shaped first alignment mark 57 having a central portion passing through the corner is formed by photolithography.

  In the first substrate functional pattern forming step (Step 1) and the first alignment mark forming step (Step 2), the step of exposing the functional surface 55a of the illumination substrate 50 and the step of exposing the alignment mark surface 55b of the illumination substrate 50. Then, the lighting substrate 50 may be etched to form a light emitting element 52 and a first alignment mark 57 that will be a functional pattern of a wiring or a functional layer. As a result, the light emitting element 52 and the first alignment mark 57, which are the wiring pattern of the illumination substrate 50 or the functional pattern of the functional layer, and the first alignment mark 57 can be formed at the same time, so that the working efficiency can be improved and the manufacturing cost can be reduced. .

<Third substrate functional pattern forming step (Step 3)>
In the third substrate functional pattern forming step (Step 3), as shown in FIG. 5A and FIG. 5B, the functional surface 65a that is the surface on the Z-axis (−) direction side of the condensing substrate 60 as the third substrate is wired or The microlenses 62 serving as the functional pattern of the functional layer are formed using a reflow method, an area gradation mask method, a microlens method, a molding method, or the like so as to be arranged in a matrix in the sensing region 5. Further, a rectangular alignment mark 66 is formed diagonally outside the sensing region 5 on the functional surface 65a by photolithography. Note that the size of the alignment mark 66 is preferably smaller than the inner edge of the frame-shaped alignment mark 56 formed on the illumination substrate 50.

<First substrate / third substrate bonding step (Step 4)>
In the first substrate / third substrate bonding step (Step 4), as shown in FIG. 6, the functional surface 65a of the condensing substrate 60 is disposed on the functional surface 55a of the illumination substrate 50 so as to face each other and close to each other. As seen from the direction of the arrow, as shown in FIG. 7, the alignment mark 66 formed on the functional surface 65a of the condensing substrate 60 is arranged at the center of the alignment mark 56 formed on the functional surface 55a of the illumination substrate 50. Adjust the position as required. Then, the space | interval of the illumination board | substrate 50 and the condensing board | substrate 60 is expanded, the transparent adhesive agent 63 (refer FIG. 12) is apply | coated to the substantially uniform thickness on the illuminating board 50, and the illumination board | substrate 50 and the condensing board | substrate 60 are again. , The position of the alignment mark 56 and the alignment mark 66 is adjusted, and pressure is applied from the light collecting substrate 60 side. Thereafter, the adhesive 63 is hardened by heat treatment, and the illumination substrate 50 and the light collecting substrate 60 are joined. The distance between the alignment mark 56 on the illumination board 50 and the alignment mark 66 on the light collection board 60 is very small due to the thickness of the adhesive 63, and the focal length of the camera is difficult to shift. The substrate 60 can be aligned and bonded with high accuracy.

Next, steps up to the second substrate / fourth substrate bonding step (Step 8) for bonding the light shielding substrate 40 and the sensor substrate 10 will be described with reference to FIGS. 8A to 11.
FIG. 8A is a schematic plan view showing the configuration of the second substrate according to the present embodiment. FIG. 8B is a schematic cross-sectional view of the second substrate along the line DD ′ of FIG. 8A. FIG. 9A is a schematic plan view showing the configuration of the fourth substrate according to the present embodiment. FIG. 9B is a schematic cross-sectional view of the fourth substrate along the line EE ′ of FIG. 9A. FIG. 10 is a schematic cross-sectional view for explaining alignment between the second substrate and the fourth substrate. FIG. 11 is a schematic plan view showing a state in which the alignment mark on the second substrate and the alignment mark on the fourth substrate are aligned.

<Second substrate functional pattern forming step (Step 5)>
In the second substrate functional pattern forming step (Step 5), as shown in FIGS. 8A and 8B, the functional surface 45a that is the surface on the Z-axis (−) direction side of the light shielding substrate 40 as the second substrate is made of Cr or the like. A metal film is formed, and a light shielding film 42 serving as a functional pattern of a wiring or functional layer having an opening 43 at a position corresponding to the photodiode 13 formed on the sensor substrate 10 described later is formed by a photolithography technique. Further, a frame-like alignment mark 46 having a central portion penetrating diagonally outward from the sensing region 5 on the functional surface 45a is formed by photolithography.

<Second Alignment Mark Forming Step (Step 6)>
In the second alignment mark formation step (Step 6), a metal film such as chrome is formed on the alignment mark surface 45b facing the functional surface 45a of the light shielding substrate 40, and the pair in the direction opposite to the position where the alignment mark 46 is formed. A second alignment mark 47 having a rectangular shape at the corner is formed by photolithography. The size of the second alignment mark 47 is preferably smaller than the inner edge of the frame-shaped first alignment mark 57 formed on the illumination substrate 50.

  In the second substrate functional pattern forming step (Step 5) and the second alignment mark forming step (Step 6), the step of exposing the functional surface 45a of the light shielding substrate 40 and the step of exposing the alignment mark surface 45b of the light shielding substrate 40. Then, the light shielding substrate 40 may be etched to form a light shielding film 42 and a second alignment mark 47 to be a functional pattern of a wiring or a functional layer. As a result, the light shielding film 42 and the second alignment mark 47 serving as the functional pattern of the wiring of the light shielding substrate 40 or the functional layer can be formed at the same time, so that the working efficiency can be improved and the manufacturing cost can be reduced. .

<Fourth Substrate Functional Pattern Formation Step (Step 7)>
In the fourth substrate functional pattern forming step (Step 7), as shown in FIGS. 9A and 9B, wiring or functions are provided on the functional surface 15a that is the surface on the Z-axis (+) direction side of the sensor substrate 10 as the fourth substrate. Photodiodes 13, circuit portions 12, and terminals 14 that are arranged at equal intervals in the X direction and the Y direction in the sensing region 5 that is the functional pattern of the layer are formed by photolithography. In addition, a rectangular alignment mark 16 is formed diagonally outside the sealing material 20 on the functional surface 15a by photolithography. Thereafter, a sealing material 20 is formed so as to surround the photodiode 13 and the circuit portion 12.

<Second substrate / fourth substrate bonding step (Step 8)>
In the second substrate / fourth substrate bonding step (Step 8), as shown in FIG. 10, after the pedestal 31 is formed inside the sealing material 20 on the functional surface 15a of the sensor substrate 10, the translucency is formed on the pedestal 31. The resin 35 is applied to a substantially uniform thickness to form the translucent member 30. Thereafter, the functional surface 45a of the light shielding substrate 40 is disposed on the functional surface 15a so as to face each other and approach each other, and is formed on the functional surface 15a of the sensor substrate 10 as shown in FIG. The position of the alignment mark 16 is adjusted so that the alignment mark 16 is arranged at the center of the alignment mark 46 formed on the functional surface 45 a of the light shielding substrate 40. Thereafter, pressure is applied from the light shielding substrate 40 side and heat treatment is performed, whereby an adhesive (not shown) provided on the sealing material 20 is solidified, and the sensor substrate 10 and the light shielding substrate 40 are bonded. The distance between the alignment mark 16 on the sensor substrate 10 and the alignment mark 46 on the light shielding substrate 40 is slightly different from the focal length of the camera because the sealing material 20 is interposed, but the sensor substrate 10 and the light shielding substrate 40 are accurately aligned. And can be joined.

Finally, a first substrate / second substrate bonding step (Step 9) for bonding the illumination substrate 50 to which the condensing substrate 60 is bonded and the light shielding substrate 40 to which the sensor substrate 10 is bonded is described with reference to FIGS. Will be described with reference to FIG.
FIG. 12 is a schematic cross-sectional view for explaining alignment between the first substrate to which the third substrate is bonded and the second substrate to which the fourth substrate is bonded. FIG. 13 is a schematic plan view showing a state in which the first alignment mark on the first substrate and the second alignment mark on the second substrate are aligned. FIG. 14 is a schematic cross-sectional view showing the imaging device that has been assembled.

<First substrate / second substrate bonding step (Step 9)>
In the first substrate / second substrate bonding step (Step 9), as shown in FIG. 12, the illumination substrate 50 in which the condensing substrate 60 is bonded onto the alignment mark surface 45b of the light shielding substrate 40 to which the sensor substrate 10 is bonded. The second alignment mark 47 formed on the alignment mark surface 45b of the light-shielding substrate 40 is illuminated as shown in FIG. 13 when viewed from the direction of the arrow. The position is adjusted so that the central portion of the first alignment mark 57 formed on the alignment mark surface 55b of the substrate 50 is disposed. Thereafter, the interval between the light shielding substrate 40 and the illumination substrate 50 is widened, and a transparent adhesive 63 (see FIG. 14) is applied on the light shielding substrate 40 to a substantially uniform thickness. The position of the second alignment mark 47 and the first alignment mark 57 is adjusted by narrowing the interval, and pressure is applied from the light collecting substrate 60 side. Thereafter, the adhesive 63 is solidified by heat treatment, and the light shielding substrate 40 to which the sensor substrate 10 is bonded and the illumination substrate 50 to which the light collecting substrate 60 is bonded are bonded.

  Note that the distance between the second alignment mark 47 of the light shielding substrate 40 and the first alignment mark 57 of the illumination substrate 50 is very small due to the thickness of the adhesive 63, and the focal length of the camera is difficult to shift. The light-shielding substrate 40 bonded to the light-emitting substrate 50 and the illumination substrate 50 bonded to the light collecting substrate 60 can be aligned and bonded with high accuracy.

  DESCRIPTION OF SYMBOLS 1 ... Imaging device, 5 ... Sensing area | region, 6 ... Optical axis, 7 ... Inspection light, 8 ... Unnecessary light, 10 ... Sensor board | substrate as 4th board | substrate, 11 ... Sensor board | substrate body, 12 ... Circuit part, 13 ... Photo Diode, 14 ... terminal, 15a ... functional surface, 16 ... alignment mark, 20 ... sealing material, 30 ... translucent member, 31 ... pedestal, 35 ... translucent resin, 39 ... air gap, 40 ... second substrate , 41 ... a light shielding substrate body, 42 ... a light shielding film, 43 ... an opening, 45a ... a functional surface, 45b ... an alignment mark surface, 46 ... an alignment mark, 47 ... a second alignment mark, 50 ... as a first substrate Illumination substrate, 51 ... illumination substrate body, 52 ... light emitting element, 55a ... functional surface, 55b ... alignment mark surface, 56 ... alignment mark, 57 ... first alignment mark, 60 ... third substrate And condensing substrates of, 61 ... light condensing substrate main body, 62 ... microlens, 63 ... adhesives, 65a ... functional, 66 ... alignment mark.

Claims (6)

The alignment mark surface of the first substrate having the first alignment mark formed on the alignment mark surface facing the functional surface having the wiring or functional layer;
The alignment mark surface of the second substrate having a second alignment mark formed on the alignment mark surface facing the functional surface having the wiring or functional layer;
Facing each other,
A method for assembling substrates, comprising the step of confirming a relative position between the first alignment mark and the second alignment mark and bonding the first substrate and the second substrate.   The method for assembling substrates according to claim 1, wherein a third substrate is bonded to the functional surface of the first substrate.   The method for assembling substrates according to claim 1, wherein a fourth substrate is bonded to the functional surface of the second substrate. Forming a pattern of the wiring or the functional layer on the functional surface of the first substrate;
Forming the first alignment mark on the alignment mark surface of the first substrate;
Forming a pattern of the wiring or the functional layer on the functional surface of the second substrate;
Forming the second alignment mark on the alignment mark surface of the second substrate;
4. The method for assembling substrates according to any one of claims 1 to 3, wherein: Exposing the functional surface of the first substrate;
Exposing the alignment mark surface of the first substrate;
An etching step of etching the first substrate to form a pattern of the wiring or the functional layer and the first alignment mark;
The method for assembling the substrates according to claim 4, wherein: Exposing the functional surface of the second substrate;
Exposing the alignment mark surface of the second substrate;
Etching the second substrate to form a pattern of the wiring or the functional layer and the second alignment mark;
6. The method for assembling substrates according to claim 4 or 5, wherein:

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