JP2012252183A - Manufacturing method for microlens substrate, image pickup device including microlens substrate manufactured using manufacturing method for microlens substrate, and electronic apparatus including image pickup device - Google Patents

Abstract

A method of manufacturing a microlens substrate capable of increasing the degree of freedom of lens formation, an imaging device including a microlens substrate manufactured using the method of manufacturing a microlens substrate, and an electronic device including the imaging device Provide equipment.
A step of forming a base pattern 17 having a reflective film 18 around a region 522 where a microlens 14 is formed, and a photosensitive layer made of a positive photosensitive material on a substrate 12 on which the base pattern 17 is formed. 52, a step of exposing the photosensitive layer 52 other than the region corresponding to the microlens 14 from the opposite side of the substrate 12 with the photosensitive layer 52 interposed therebetween, and developing the exposed photosensitive material And a step of forming the microlens 14 by deforming the surface of the photosensitive material into a curved surface by heating.
[Selection] Figure 4

Description

  The present invention relates to a manufacturing method of a microlens substrate, an imaging device including a microlens substrate manufactured using the manufacturing method of the microlens substrate, and an electronic apparatus including the imaging device.

  A microlens substrate in which a plurality of microlenses are formed on a substrate is used for various electronic devices such as an imaging device and a display device. For example, Patent Document 1 discloses a configuration in which a microlens substrate is installed in an imaging device used as a biometric authentication device (vein sensor).

  In addition, in the method for manufacturing a microlens described in Patent Document 2, there is a technique for forming a microlens by heating a pattern of a photosensitive material formed by using a photolithography technique to deform the surface into a curved surface. It is disclosed.

JP 2008-36058 A JP 2006-235084 A

  However, in the microlens manufacturing methods described in Patent Document 1 and Patent Document 2, in order to obtain a desired radius of curvature of the microlens, it is necessary to finely manage the film thickness or select an optimal material. There is a problem of not becoming. Therefore, there is a problem that it is difficult to expand the use range of the microlens (the manufacturing range of the curvature radius) only by the method described in the above-mentioned patent document.

  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 of manufacturing a microlens substrate according to this application example includes a reflective film forming step of forming a reflective film with a reflective material around a region where a microlens is formed in the substrate, and the reflective film includes: A photosensitive layer forming step of forming a photosensitive layer with a positive photosensitive material on the formed substrate, and a region of the photosensitive layer other than the region corresponding to the microlens with the photosensitive layer interposed therebetween. An exposure step of exposing from the opposite side, a development step of developing the exposed photosensitive material, and a heating step of forming the microlens by deforming the surface of the photosensitive material into a curved shape by heating. , Including.

  According to this method, since the reflective film is formed around the region where the microlens is formed on the substrate, the substantially edge of the reflective film is made an outer shape by irradiation of light reflected by the surface of the reflective film in the exposure process. The photosensitive layer can be exposed in an inverted trapezoidal shape. Therefore, the height of the photosensitive layer in the heating process can be increased and the radius of curvature of the microlens can be reduced as compared with the case where no reflective film is formed. As a result, the range of the radius of curvature of the microlens can be expanded without adjusting the film thickness or selecting a material.

  Application Example 2 In the method for manufacturing a microlens substrate according to the application example, it is preferable that the reflection film forming step forms the reflection film on the antireflection film on the substrate.

  According to this method, since the reflection film is formed on the antireflection film, it is possible to suppress irregular reflection of light on the substrate side of the antireflection film. Therefore, variation in the curvature of the microlens can be suppressed.

  Application Example 3 In the method of manufacturing a microlens substrate according to the application example, it is preferable that the reflection film forming step forms the reflection film in a closed shape surrounding a region where the microlens is formed.

  According to this method, since the reflective film is formed in a closed shape, the light reflected from the surface of the reflective film is uniformly irradiated on the periphery of the region corresponding to the microlens in the photosensitive layer in the exposure process. Therefore, for example, a microlens precursor having an appropriate cross-sectional shape can be formed as compared with a case where the reflective film is composed of a plurality of separated films.

  Application Example 4 In the method for manufacturing a microlens substrate according to the application example, it is preferable that the reflection film is formed in an annular shape in the reflection film formation step.

  According to this method, since it is formed in an annular shape, reflected light from the surface of the reflective film is uniformly applied to the periphery of the region corresponding to the microlens in the photosensitive layer in the exposure step. Therefore, a microlens precursor having a more appropriate cross-sectional shape can be formed.

  Application Example 5 In the method for manufacturing a microlens substrate according to the application example, the exposure step uses a mask in which a light shielding portion overlaps a region corresponding to the microlens, and the periphery of the light shielding portion is formed on the reflective film. It is preferable to be located between the inner periphery and the outer periphery.

  According to this method, since the periphery of the light-shielding portion is located between the inner periphery and the outer periphery of the reflection film, in the exposure step, the periphery of the region corresponding to the microlens in the photosensitive layer is exposed from the surface of the reflection film. It is possible to sufficiently irradiate the reflected light.

  Application Example 6 In the method of manufacturing a microlens substrate according to the application example, the reflective film forming step selectively forms the light reflective reflective film that covers the substrate, and the reflective film is selectively removed. Thus, it is preferable to include a step of collectively forming the reflective film and alignment marks used for alignment of the microlens substrate.

  According to this method, since the reflective film and the alignment mark are formed in a common process, the manufacturing process of the microlens substrate is simplified as compared with the case where the reflective film and the alignment mark are formed in separate processes. There is an advantage.

  Application Example 7 An imaging apparatus according to this application example includes a microlens substrate manufactured by using the microlens substrate manufacturing method described above.

  According to this configuration, since the microlens substrate manufacturing method described above is used, the range of the radius of curvature of the microlens can be expanded. For example, when the radius of curvature is small, the focal length is shortened. As a result, a thin imaging device can be provided. In addition, an imaging apparatus including microlenses with different depths of focus on one substrate can be provided.

  Application Example 8 An electronic apparatus according to this application example includes the imaging device described above.

  According to this configuration, since the above-described imaging device is provided, a thin electronic device can be provided, or an electronic device capable of imaging a wide range of distances can be provided.

FIG. 2 is a schematic cross-sectional view illustrating a structure of a microlens substrate and an imaging device including the microlens substrate. The top view of the opposing surface with the light-shielding board | substrate in a micro lens board | substrate. The schematic cross section which follows the AA 'line of the micro lens board | substrate in FIG. The schematic cross section which shows the manufacturing method of a micro lens board | substrate in order of a process. The top view which shows the positional relationship of a base pattern and the light-shielding part of a mask. FIG. 5 is a schematic cross-sectional view showing some steps in the method for manufacturing a microlens substrate. FIG. 5 is a schematic cross-sectional view showing some steps in the method for manufacturing a microlens substrate. The graph which shows the relationship between the radius of a micro lens, and the height of a micro lens. The block diagram which shows the structure of a biometrics apparatus. (A) is a perspective view showing a portable telephone as an electronic device, (b) is a schematic diagram showing a personal computer as an electronic device. The schematic plan view which shows the structure of the microlens board | substrate of a modification. The schematic plan view which shows the structure of the microlens board | substrate of a modification.

  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.

<Configuration of microlens substrate, imaging device, and electronic device>
FIG. 1 is a schematic cross-sectional view illustrating the structure of a microlens substrate and an imaging apparatus including the microlens substrate. FIG. 2 is a plan view of the surface of the microlens substrate that faces the light-shielding substrate. FIG. 3 is a cross-sectional view taken along line AA ′ of the microlens substrate in FIG. Hereinafter, the structure of the microlens substrate and the imaging device (and electronic apparatus) including the microlens substrate will be described with reference to FIGS.

  As shown in FIG. 1, the imaging apparatus 100 is used in, for example, a biometric authentication apparatus (vein sensor) as an electronic device that captures a vein image of a living body (for example, a finger) 200 for authentication processing. And a microlens substrate 10, a light shielding substrate 20, and a light receiving substrate 30. The microlens substrate 10 is interposed between the light receiving substrate 30 and the living body 200, and the light shielding substrate 20 is interposed between the microlens substrate 10 and the light receiving substrate 30.

  As shown in FIGS. 1 to 3, the microlens substrate 10 includes a substrate 12, a plurality of microlenses 14, and a plurality of base patterns 17. The substrate 12 is a light-transmitting plate member such as a glass substrate.

  Each of the plurality of microlenses 14 is a convex lens that condenses incident light, and is arranged in an array on the surface 13 of the substrate 12 as shown in FIG. Each of the plurality of base patterns 17 is disposed on the surface 13 of the substrate 12 for each microlens 14.

  As shown in FIG. 2, each base pattern 17 is an annular pattern surrounding the microlens 14 in plan view, and includes a reflective film 18 having light reflectivity and an antireflection film 19 for suppressing light reflection. Are stacked. The antireflection film 19 is disposed on the living body 200 side and prevents noise from being generated by the reflected light from the reflection film 18.

  The light shielding substrate 20 shown in FIG. 1 includes a light transmissive substrate 22 and a light shielding layer 24 formed on the surface of the substrate 22. The light shielding layer 24 is formed of a light shielding material. An opening 26 is formed at a location corresponding to the optical axis of each microlens 14 in the light shielding layer 24.

  The microlens substrate 10 and the light shielding substrate 20 are disposed to face each other via a spacer (not shown). Therefore, the microlenses 14 are disposed to face the surface 23 of the substrate 22 with a space therebetween.

  The light receiving substrate 30 shown in FIG. 1 includes a substrate 32 and a plurality of light receiving elements 34 formed on the surface of the substrate 32. In addition, the light receiving substrate 30 faces the light shielding substrate 20 with a space therebetween. Each light receiving element 34 is formed at a position corresponding to the optical axis of the microlens 14 and generates a detection signal corresponding to the amount of incident light.

  In the above configuration, as indicated by an arrow α in FIG. 1, the light emitted from a light source (not shown) disposed at a predetermined position (for example, on the side opposite to the microlens substrate 10 across the living body 200) is irradiated with the living body 200. Then, the light is transmitted or reflected by a vein inside the substrate 12 and enters the substrate 12. The irradiation light is collected by each microlens 14, passes through the opening 26 of the light shielding layer 24, and reaches the light receiving element 34. That is, a vein image of the living body 200 is captured.

<Method of manufacturing microlens substrate>
FIG. 4 is a schematic cross-sectional view showing a method of manufacturing a microlens substrate in the order of steps. FIG. 5 is a schematic plan view showing a planar positional relationship between the base pattern and the light shielding portion of the mask. 6 and 7 are schematic cross-sectional views showing some steps in the manufacturing method. Hereinafter, a method for manufacturing the microlens substrate will be described with reference to FIGS.

  First, in the step shown in FIG. 4A, a reflective film 18a (reflective film precursor film) and an antireflective film 19a, which will later become the base pattern 17, are formed on the substrate 12. Specifically, an antireflection film 19a that suppresses reflection of light is formed on the surface 13 of the substrate 12, and a light reflective reflection film 18a is formed on the antireflection film 19a.

  As the material of the reflective film 18a, for example, a highly reflective metal material such as aluminum (Al), silver (Ag), or gold (Au) is suitable. Examples of the material of the antireflection film 19a include titanium (Ti), molybdenum (Mo), an organic material (for example, an acrylic resin in an organic solvent containing 30% acrylic resin), and the like.

  In addition, as a method for forming the reflection film 18a and the antireflection film 19a, a known film formation technique such as a sputtering method, a vacuum evaporation method, or a CVD (Chemical Vapor Deposition) method is arbitrarily employed.

  Next, in a step (reflection film forming step) shown in FIG. 4B, a base pattern 17 is formed on the substrate 12. Specifically, an annular base pattern 17 having a reflection film 18 and an antireflection film 19 is formed so as to surround a region where the microlenses 14 are to be formed on the surface 13 of the substrate 12. As a method for forming the base pattern 17, for example, a known patterning technique such as a photolithography technique can be used. It is also possible to form a plurality of base patterns 17 directly on the surface 13 of the substrate 12 by a method such as mask vapor deposition.

  Next, in the step shown in FIG. 4C (photosensitive layer forming step), the photosensitive layer 52 is formed on the substrate 12. Specifically, the photosensitive layer 52 is formed so as to cover the entire surface 13 of the substrate 12 on which the base pattern 17 is formed. For the photosensitive layer 52, a positive photosensitive material from which an exposed portion is removed is used. Specifically, a polymer resin material such as acrylic or polyimide is suitable as the material for the photosensitive layer 52. As a method for forming the photosensitive layer 52, for example, a known film forming technique such as a spin coating method or a roll coating method can be used.

  Next, in the step (exposure step) shown in FIG. 4D, the photosensitive layer 52 is exposed. Specifically, the photosensitive layer 52 is selectively exposed from the side opposite to the substrate 12 with the photosensitive layer 52 interposed therebetween. For exposure of the photosensitive layer 52, for example, a mask 60 having a light shielding portion 62 is used. The light shielding portion 62 is disposed in a portion of the photosensitive layer 52 that overlaps each region (region where the microlens 14 is to be formed) 522 corresponding to the microlens 14. That is, an area of the photosensitive layer 52 excluding the area 522 is exposed.

  As shown in FIG. 5, the light shielding portion 62 is formed in a circular shape having a diameter Db and is arranged concentrically with the annular base pattern 17. The diameter Db is selected to be a dimension that is equal to or larger than the inner diameter (substantially the diameter of the region 522 corresponding to the microlens 14) Di of the base pattern 17 and smaller than the outer diameter Do of the base pattern 17. Therefore, the periphery of the light shielding part 62 is located between the inner periphery and the outer periphery of the base pattern 17 in plan view.

  Since the periphery of the light shielding part 62 is located between the inner periphery and the outer periphery of the reflective film 18, in the exposure process, the periphery of the region corresponding to the microlens 14 in the photosensitive layer 52 is exposed from the surface of the reflective film 18. It is possible to sufficiently irradiate the reflected light.

  Next, in the step (development step) shown in FIG. 4E, the photosensitive layer 52 is developed (patterned). Specifically, the region exposed in the step shown in FIG. 4D is removed from the photosensitive layer 52. As a result, a plurality of microlens precursors 72 corresponding to the region 522 shielded by the light shielding part 62 is formed on the substrate 12.

  Specifically, as shown in FIG. 6, the light that has passed through the mask 60 (light-shielding portion 62) and entered the region 524 in the photosensitive layer 52 travels straight through the photosensitive layer 52 and then the underlying pattern 17. , And is reflected (scattered) by the surface of the reflective film 18 constituting the base pattern 17.

  The reflected light from the surface of the base pattern 17 is irradiated to the peripheral portion of the region 524 in the photosensitive layer 52. Therefore, as shown in FIG. 7, the side surface 722 of the microlens precursor 72 is inclined with respect to the surface 13 such that the diameter (cross-sectional area) of the microlens precursor 72 increases as the position is farther from the surface 13. To do.

  That is, the area Am1 of the top surface of the microlens precursor 72 exceeds the area of the bottom surface (that is, the area inside the base pattern 17) Am2. Schematically, the cross-sectional shape of the microlens precursor 72 in a cross section perpendicular to the surface 13 is an inverted trapezoid whose upper base is higher than the lower base.

  Next, in the process (heating process) shown in FIG. 4F, the microlens 14 is completed on the substrate 12. Specifically, the microlens precursor 72 is softened (melted) by heating (reflow treatment). The microlens precursor 72 flows by heating, and the surface is deformed into a curved surface by the action of surface tension. At this time, the area Am2 (see FIG. 7) of the bottom surface hardly changes. Thereafter, the microlens precursor 72 is cooled to complete the microlens 14.

  The temperature of heat processing is 150 degreeC-250 degreeC, for example. The microlens substrate 10 manufactured by the above steps and the separately manufactured light-shielding substrate 20 are arranged to face each other as shown in FIG.

  As described with reference to FIGS. 6 and 7, when the reflow process (heating) is performed, the area Am <b> 2 of the bottom surface of the microlens 14 can be substantially fixed by the base pattern 17. The curvature of the surface can be reduced as compared with the conventional one. As a result, the design range of the microlens 14 can be expanded.

  FIG. 8 is a graph showing the relationship between the radius of the microlens and the height of the microlens according to the thickness of the microlens precursor. Hereinafter, the relationship between the radius of the microlens and the height of the microlens will be described with reference to FIG.

  As shown in FIG. 8, the horizontal axis of the graph indicates the radius value of the microlens 14, and indicates that the radius value increases toward the right side of the figure. The vertical axis of the graph indicates the height of the microlens 14 and indicates that the height increases as it goes upward in the drawing. The relationship between the radius value and the height of the microlens 14 is shown for each film thickness of the microlens precursor 72.

  Graph A is a measurement of the microlens when the thickness of the microlens precursor 72 is 5.0 μm and the base pattern 17 is not formed. Graph B is obtained by measuring the microlens 14 when the thickness of the microlens precursor 72 is 5.0 μm and the base pattern 17 is formed.

  Graph C is a measurement of the microlens when the thickness of the microlens precursor 72 is 3.5 μm and the base pattern 17 is not formed. Graph D is a measurement of the microlens 14 when the thickness of the microlens precursor 72 is 3.5 μm and the base pattern 17 is formed.

  As described above, when the thickness of the microlens precursor 72 is 5.0 μm, the case where the reflective film 18 and the antireflection film 19 constituting the base pattern 17 are provided is compared with the radius value of the conventional microlens. Thus, a micro lens having a small radius value (curvature) can be formed. Thereby, compared with the design range of the conventional microlens, a design range can be expanded.

  On the other hand, when the thickness of the microlens precursor 72 is 3.5 μm, similarly, the case where the reflective film 18 and the antireflection film 19 constituting the base pattern 17 are provided is compared with the radius value of the conventional microlens. Thus, a micro lens having a small radius value (curvature) can be formed. Thereby, compared with the design range of the conventional microlens, a design range can be expanded.

  In addition, since the microlens 14 having a desired curvature can be formed by forming the base pattern 17, the film thickness (film thickness of the microlens precursor 72) is finely managed or the material is selected. This can be omitted, and the manufacturing process of the microlens substrate 10 can be simplified.

<Biometric authentication device>
Next, an example of a biometric authentication device including the imaging device of the above embodiment will be described with reference to FIG. FIG. 9 is a block diagram showing the configuration of the biometric authentication apparatus.

  As illustrated in FIG. 9, the biometric authentication device 80 of the present embodiment includes a storage unit 81, an imaging unit 82, a light emitting unit 83, an authentication execution unit 84, and a control unit 85 that controls these units. The imaging unit 82 and the light emitting unit 83 correspond to the imaging device 100. The imaging unit 82 includes the microlens substrate 10, the light shielding substrate 20, and the light receiving substrate 30, and the light emitting unit 83 corresponds to a light source.

  The light emitting unit 83 emits light (near infrared light) toward the finger based on the signal transmitted from the control unit 85. The imaging unit 82 starts an imaging operation based on the control signal transmitted from the control unit 85, and outputs the captured vein pattern to the control unit 85.

  The control unit 85 executes various processes such as signal calculation processing and signal transmission based on the program stored in the storage unit 81, and transmits the vein pattern output from the imaging unit 82 to the authentication execution unit 84.

  The storage unit 81 is a storage device such as a hard disk, a semiconductor memory (DRAM (Dynamic Random Access Memory), or SRAM (Static Random Access Memory)). The storage unit 81 stores information such as a program for realizing biometric authentication, a program for realizing an image configuration, a pre-registered vein pattern used for authentication, and an authentication history.

  The authentication execution unit 84 collates the vein pattern (image information) imaged and output by the imaging unit 82 with the previously registered vein pattern (image information) of the living body, and the living body in which the captured vein pattern is registered Judge whether or not. The vein authentication method depends on various methods for determining the similarity of vein patterns.

  Since the biometric authentication device 80 includes the imaging device 100 of the above-described embodiment, the vein pattern (biometric information) inside the finger can be obtained in a clear state. Therefore, the authentication execution unit 84 can determine similarity between each vein pattern registered in advance and the captured vein pattern, thereby realizing high authentication accuracy. In addition, higher authentication accuracy can be realized and fraud can be prevented.

<Electronic equipment>
Next, the electronic apparatus of this embodiment will be described with reference to FIG. FIG. 10A is a perspective view showing a mobile phone as an electronic device, and FIG. 10B is a schematic view showing a personal computer as an electronic device.

  As shown in FIG. 10A, a mobile phone 300 as an electronic apparatus according to this embodiment includes a display unit 301, operation buttons 302, and a biometric authentication device 80. The biometric authentication device 80 uses the vein pattern acquired by touching the imaging device 100 mounted on the main body of the mobile phone 300 with a finger, for example, to release the locked state of the mobile phone 300, or Personal authentication at the time of settlement can be performed.

  As shown in FIG. 10B, a notebook personal computer 400 as an electronic apparatus according to this embodiment includes a display unit 411, an input button 412, and a biometric authentication device 80. The biometric authentication device 80 uses a vein pattern acquired by touching the imaging device 100 incorporated in the main body of the personal computer 400 with a finger, for example, logs into the personal computer 400 or performs personal authentication at the time of financial settlement. It can be performed.

  Since the mobile phone 300 and the personal computer 400 include the biometric authentication device 80 having the imaging device 100 that can capture a vein pattern regardless of whether indoors or outdoors, personal authentication can be performed with high accuracy in any environment. Can do. Therefore, unauthorized use can be prevented.

  As described above in detail, the manufacturing method of the microlens substrate 10 of the present embodiment, the imaging device 100 including the microlens substrate 10 manufactured using the manufacturing method of the microlens substrate 10, and the imaging device 100 are provided. According to the electronic apparatus, the following effects can be obtained.

  (1) According to the method for manufacturing the microlens substrate 10 of the present embodiment, the base pattern 17 having the reflective film 18 is formed around the region 522 where the microlenses 14 are formed. By irradiating the light reflected from the surface, the photosensitive layer 52 can be exposed in an inverted trapezoidal shape with the substantial edge of the reflective film 18 as an outer shape. Therefore, compared with the case where the reflective film 18 is not formed, the height of the photosensitive layer 52 in the heating process can be increased, and the radius of curvature of the microlens 14 can be reduced. As a result, the radius of curvature (design range) of the microlens 14 can be expanded without adjusting the film thickness of the microlens precursor 72 or selecting the material of the photosensitive layer 52. In addition, by changing the size of the base pattern 17 or not forming the reflective film 18, the microlenses 14 having different in-plane curvatures can be easily formed even in the same process. it can.

  (2) According to the manufacturing method of the microlens substrate 10 of the present embodiment, since the reflection film 18 is formed on the antireflection film 19, light on the substrate side of the antireflection film 19 is irregularly reflected in the exposure process. Can be suppressed. Therefore, variations in the curvature of the microlens 14 can be suppressed.

  (3) According to the imaging apparatus 100 including the microlens 14 of the present embodiment, the range of the radius of curvature of the microlens 14 can be expanded. For example, when the radius of curvature is small, the focal length is shortened. As a result, the thin imaging device 100 can be provided. In addition, it is possible to provide the imaging apparatus 100 including the microlenses 14 having different focal depths on one substrate.

  (4) According to the electronic apparatus of the present embodiment, since the above-described imaging device 100 is provided, a thin electronic apparatus can be provided or an electronic apparatus capable of imaging a wide range of distances can be provided. can do.

  In addition, embodiment is not limited above, It can also implement with the following forms.

(Modification 1)
As described above, the base pattern 17 is not limited to an annular pattern surrounding the region where the microlenses 14 are formed. For example, as shown in FIG. 11, the region where the microlenses 14 are formed. It may be formed in all regions except for.

  FIG. 11 is a schematic plan view showing the structure of the microlens substrate (underlying pattern). In the base pattern 117 of the microlens substrate 110 shown in FIG. 11, an antireflection film 119 is formed on the substrate 112, and a reflection film 118 is formed on the antireflection film 119. That is, the base pattern 117 is not formed only in the region where the microlenses 14 are formed.

  According to this, in addition to the effect of the above-described embodiment, the same effect as when the BM is arranged can be obtained without separately arranging the BM between the microlenses 14. Further, since many materials having high light reflectivity are used and heat transfer is fast and there is a heat storage action, the shape of the microlens can be made uniform during heating (reflow treatment).

(Modification 2)
As described above, the base pattern 17 is not limited to being formed in a planar continuous annular shape, and may have a shape as shown in FIG. 12, for example. FIG. 12 is a schematic plan view showing the structure of a modification of the base pattern.

  In the base pattern 17 shown in FIG. 12A, a region where the microlenses 14 are formed is formed in a polygonal (for example, hexagonal) ring shape. Further, the base pattern 17 shown in FIG. 12B is not formed in a closed annular shape, but is formed in an annular shape separated into a plurality.

  From the viewpoint of uniformly irradiating the periphery of the region 524 (see FIG. 6) of the photosensitive layer 52 with the reflected light from the base pattern 17, the base pattern 17 is closed (for example, a circular or polygonal ring). The structure formed in (1) is preferred.

(Modification 3)
As described above, the base pattern 17 is not limited to the laminated configuration of the reflective film 18 and the antireflection film 19, and may be a configuration of only the reflective film 18, for example. According to this structure, it becomes possible to apply when there are comparatively few irregular reflections, and a manufacturing process can be simplified.

(Modification 4)
As described above, the method of forming the base pattern 17 is not limited to the method of stacking and patterning the antireflection film 19a and the reflective film 18a for the base pattern 17, and for example, for forming a mark at the time of bonding. The used formation layer may be applied as the base pattern 17. According to this method, since the base pattern 17 and the alignment mark are formed in a common process, the manufacturing process of the microlens substrate 10 is simplified as compared with the case where the base pattern 17 and the alignment mark are formed in separate processes. Can be

  DESCRIPTION OF SYMBOLS 10,110 ... Microlens board | substrate, 12, 22, 112 ... Board | substrate, 13 ... Surface, 14 ... Microlens, 17,117 ... Base pattern, 18, 18a, 118 ... Reflective film, 19, 19a, 119 ... Antireflection film , 20 ... light shielding substrate, 23 ... surface, 24 ... light shielding layer, 26 ... opening, 30 ... light receiving substrate, 32 ... substrate, 34 ... light receiving element, 52 ... photosensitive layer, 60 ... mask, 62 ... light shielding portion, 72 ... Microlens precursor, 80 ... biometric authentication device, 81 ... storage unit, 82 ... imaging unit, 83 ... light emitting unit, 84 ... authentication execution unit, 85 ... control unit, 100 ... imaging device, 112 ... substrate, 200 ... biological body, 300 ... mobile phone, 301,411 ... display unit, 302 ... operation button, 400 ... personal computer, 412 ... input button, 522,524 ... area, 722 ... side.

Claims (8)

A reflective film forming step of forming a reflective film with a reflective material around a region of the substrate where the microlens is formed;
A photosensitive layer forming step of forming a photosensitive layer with a positive photosensitive material on the substrate on which the reflective film is formed;
An exposure step of exposing a region other than the region corresponding to the microlens in the photosensitive layer from the opposite side of the substrate with the photosensitive layer interposed therebetween;
A development step of developing the exposed photosensitive material;
A heating step of forming the microlens by deforming the surface of the photosensitive material into a curved surface by heating;
A method for manufacturing a microlens substrate, comprising: A method of manufacturing a microlens substrate according to claim 1,
The method of manufacturing a microlens substrate, wherein the reflecting film forming step forms the reflecting film on an antireflection film on the substrate. A method of manufacturing a microlens substrate according to claim 1 or 2,
The method of manufacturing a microlens substrate, wherein the reflecting film forming step forms the reflecting film in a closed shape surrounding a region where the microlens is formed. A method of manufacturing a microlens substrate according to claim 3,
In the reflective film forming step, the reflective film is formed in an annular shape. A method of manufacturing a microlens substrate according to any one of claims 1 to 4,
The exposure step uses a mask in which a light shielding portion overlaps an area corresponding to the microlens,
The manufacturing method of a microlens substrate, wherein a peripheral edge of the light shielding portion is located between an inner peripheral edge and an outer peripheral edge of the reflective film. A method of manufacturing a microlens substrate according to any one of claims 1 to 5,
The reflective film forming step includes a step of forming a light reflective reflective film precursor film covering the substrate;
And a step of collectively forming the reflective film and an alignment mark used for alignment of the microlens substrate by selectively removing the reflective film precursor film. A method for manufacturing a lens substrate.   An imaging apparatus comprising a microlens substrate manufactured using the method for manufacturing a microlens substrate according to claim 1.   An electronic apparatus comprising the imaging device according to claim 7.

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