JP2013012615A - Solid state imaging device, and manufacturing method thereof, and transparent conductive film for solid state imaging device used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a solid state imaging device in which a transparent conductive film for the solid state imaging device especially suitable for a wafer level imaging module is disposed at a predetermined position, and to provide the transparent conductive film manufactured using the method, and the solid state imaging device having the transparent conductive film.SOLUTION: Disclosed is a method for manufacturing a solid state imaging device having a transparent conductive film on the surface of an internal member. In the solid state imaging device, the transparent conductive film containing at least one of conductive metal particles, a conductive metal nanowire, conductive oxide particles and a conductive polymer is disposed in the internal member.

Description

  The present invention relates to a solid-state imaging device, a manufacturing method thereof, a transparent conductive film for the solid-state imaging device used therein, and the like.

  Mobile electronic devices equipped with an imaging module are becoming smaller and thinner and are rapidly spreading. In response to this, the demand for a small, light, and inexpensive imaging module is increasing. For example, mobile phones with built-in cameras are not only equipped with imaging modules but also modules for other digital electronic devices, and there is a need to develop imaging devices with stable quality and good processability. .

  The wafer level imaging module has been devised to satisfy the above requirements. The lens module (hereinafter referred to as a wafer level lens module or WLL) has a laminated structure of a transparent substrate and a polymer lens formed on the surface thereof. Such a wafer level lens module is manufactured by aligning and laminating a plurality of transparent wafers having polymer lenses in an array form formed using a replica method, and then cutting the wafers. Therefore, not only is the size small and light, but also mass production is possible and the production cost can be significantly reduced (see Patent Documents 1 and 2).

JP 2010-282179 A JP 2010-56170 A

  The structure and manufacturing technology of the wafer level imaging module are being developed as described above. However, the technology related to the material applied there has not been sufficiently studied. For example, it is desirable to prevent external radiation of electromagnetic waves in consideration of the effects on the human body, but there has been almost no full-scale research and development on such issues. Further, in the future, it is anticipated that the signal processing (data rate) will be faster due to the increase in the number of pixels, and the proximity of the RF circuit due to the reduction in the chip size, and further improvements in shielding performance will be required. In particular, there is a need to improve strong electromagnetic shielding properties in medical applications such as endoscopes and in-vehicle applications. Specifically, in the case of terrestrial digital / GSM / overseas 3G / wireless LAN, it is about 400 MHz to 2500 MHz, and it is required to provide electromagnetic shielding properties in this frequency region.

  Accordingly, the present invention provides a method for manufacturing a solid-state imaging device in which a transparent conductive film for a solid-state imaging device that is particularly suitable for a wafer level imaging module is disposed at a predetermined location, the transparent conductive film manufactured thereby, An object of the present invention is to provide a solid-state imaging device having the same. In particular, it has not only sufficient transparency but also good moldability and conductivity, suppresses external radiation such as electromagnetic waves, or exhibits electromagnetic shielding properties, and is excellent in terms of film formation temperature and heat resistance. It is an object of the present invention to provide a method for producing a solid-state imaging device having a transparent conductive film, the transparent conductive film produced thereby, and a solid-state imaging device having the same.

The above problem has been solved by the following means.
(1) A method for producing a solid-state imaging device having a transparent conductive film on the surface of an internal member, comprising at least one of conductive metal particles, conductive metal nanowires, conductive oxide particles, and a conductive polymer A method for manufacturing a solid-state imaging device, wherein a transparent conductive film is disposed on the internal member.
(2) The method for manufacturing a solid-state imaging element according to (1), including a step of dicing a member stack provided on the wafer after the step of disposing a transparent conductive film on the member.
(3) The manufacturing method of the solid-state image sensor as described in (1) or (2) by a wafer level process.
(4) The method for manufacturing a solid-state imaging element according to any one of (1) to (3), wherein the conductive metal particles are selected from the group consisting of Au, Ag, Cu, and a composite thereof.
(5) The method for manufacturing a solid-state imaging element according to any one of (1) to (4), wherein the conductive metal nanowire is selected from the group consisting of Au, Ag, and Cu.
(6) The manufacturing of the solid-state imaging element according to any one of (1) to (5), wherein the conductive oxide particles are selected from the group consisting of indium, tin, antimony, aluminum, titanium, and zinc. Method.
(7) The method for producing a solid-state imaging device according to any one of (1) to (6), wherein the conductive polymer is selected from the group consisting of polyaniline, polypyrrole, and PEDOT (polyethylenedioxythiophene).
(8) A method for manufacturing a camera module, comprising: a step of producing a solid-state imaging device by the production method according to any one of (1) to (7);
(9) A transparent conductive film formed on the surface of the internal member of the solid-state imaging device by the manufacturing method according to any one of (1) to (8),
A transparent conductive film containing at least one of conductive metal particles, conductive metal nanowires, conductive oxide particles, and a conductive polymer.
(10) A solid-state imaging device comprising the transparent conductive film according to (9).
(11) A camera module comprising the solid-state imaging device according to (10).
(12) Use of the transparent conductive film according to (9) as an electromagnetic wave shielding film.
(13) A transparent conductive coating disposed on the surface of an internal member of a solid-state imaging device to form a transparent conductive film, comprising conductive metal particles, conductive metal nanowires, conductive oxide particles, and a conductive polymer A transparent conductive paint for a solid-state imaging device containing at least any one of them.

  According to the present invention, a method of manufacturing a solid-state imaging device in which a transparent conductive film for a solid-state imaging device that is particularly suitable for a wafer level imaging module is disposed at a predetermined location, the transparent conductive film manufactured thereby, It is possible to provide a solid-state imaging device having In particular, it has sufficient moldability and conductivity as well as sufficient transparency, can effectively suppress external radiation such as electromagnetic waves, or exhibits electromagnetic wave shielding properties, It is possible to provide a method for manufacturing a solid-state imaging device in which a transparent conductive film excellent in heat resistance is bonded and fixed, the transparent conductive film manufactured thereby, and a solid-state imaging device having the same.

It is sectional drawing which showed typically one Embodiment of the solid-state image sensor manufactured with the manufacturing method of this invention. It is sectional drawing which shows typically one embodiment of the manufacture process of the solid-state image sensor shown in FIG. It is sectional drawing which showed typically another embodiment of the manufacturing method of this invention.

  In the manufacturing method of the present invention, in the manufacture of the solid-state imaging device in the wafer level imaging module, a specific transparent conductive film is disposed on the internal member of the solid-state imaging device to suppress external radiation such as electromagnetic waves, or External electromagnetic waves can be shielded. Hereinafter, the present invention will be described in detail.

[First Embodiment]
(Configuration example of solid-state image sensor)
FIG. 1 is a cross-sectional view schematically showing a solid-state imaging device in a wafer level imaging module according to an embodiment of the present invention. The solid-state imaging device of the present embodiment includes two layers of lens bodies 1a and 1b. Each lens body includes a lens and support plates 1a ′ and 1b ′ that support the lens, and is supported by the outer frame 2 and fixed inside the element. Further, a light receiving layer 3 is disposed in parallel to the lens body on the opposite side of the first lens body 1a across the second lens body 1b inside the element. The structure of the light receiving layer 3 is not particularly limited. However, in the case of a color imaging element, a structure having a cover glass and a color filter constituting R, G, B pixels and an image sensor 32 corresponding thereto is provided. Is mentioned.
A transparent conductive film, which is a main part of the present embodiment, is applied and formed on the surface on the second lens body side above the light receiving layer.

  Further below that, an element substrate 4 is provided at a location corresponding to the inner edge of the outer frame 2. The substrate 4 may be a glass substrate as described above, or may be a silicon wafer in a form normally used for this type of element. Furthermore, although not illustrated in the present embodiment, infrared molten solder is applied to the surface of the substrate 4 opposite to the side on which the lens body is disposed. As a result, it can be mounted on a semiconductor circuit and modularized.

  In the solid-state imaging device 10 of the present embodiment, the WLL light shielding material film B is provided outside the lens opening at the center of the lens body 1a on the outer frame side of the outer surface of the first lens body that captures light. This prevents stray light from the outside from entering the device. Furthermore, in this embodiment, the light-shielding coating film 9 formed by applying a light-shielding paint to the side surface of the outer peripheral member of the element is formed. Thereby, even when the outer frame 2 does not have a sufficient light shielding property, the light shielding property of the outer peripheral surface of the element can be maintained. In this specification, the term “member” refers to all members constituting the element, and the outer peripheral member refers to a member constituting the outer periphery or a part thereof. In the embodiment shown in FIG. 1, the outer frame 2 and a part of the lens body support constitute the outer peripheral member. Conversely, the internal member refers to a member other than the outer peripheral member, and in the embodiment shown in FIG. 1, the light receiving layer 3, the second lens body 1 b, and the like correspond thereto. In addition, the illustrated element is a schematic diagram greatly simplified for the description, and is premised on being appropriately set or changed to a practically required structure or form. This also applies to FIGS. 2 and 3.

(Example of manufacturing a solid-state image sensor)
Next, an embodiment of the method for manufacturing the solid-state imaging device of the above embodiment will be described with reference to FIG. In this embodiment, the first lens body 1a and its supporting plate 1a ′, the outer frame 2, the second lens body 1b and its supporting plate 1b ′, the outer frame 2, the light receiving layer 3, and the substrate 4 are assembled in this order. can do.
In FIG. 2, the continuous plates of the lens bodies 1 a and 1 b are laminated, and the outer frame 2 is supported at a predetermined interval, and is fixedly disposed on the base material 4 and the light receiving layer 3. As this base material 4, a wafer commonly used for semiconductor manufacturing can be applied. At this time, the cover glass 31 is provided on the lens body side surface of the light receiving layer 3, and the transparent conductive film 5 is formed on the lower surface thereof. It is preferable to form a transparent conductive film on the surface of the light receiving layer 3 because it is easy to effectively release the accumulated charges. The manufacturing method and each material of such a module can use a normal thing, for example, can refer to Unexamined-Japanese-Patent No. 2010-282179. Note that the exploded perspective view of FIG. 2 is for explaining the structure, and the manufacturing procedure is not limited to this.

(Transparent conductive film)
Here, formation of a transparent conductive film, which is an important feature in the present embodiment, will be described. This transparent conductive film is applied to the lower surface of the cover glass 31 above the light receiving layer 3 by spin coating.
This transparent conductive film is formed in advance before film formation. The material of the transparent conductive film will be described in detail later, and the film forming method includes the following. As the film forming method, for example, various methods such as a spin coating method, a spray method, a roll coating method, a die coating method, a doctor blade method, a bar coating method, and a screen printing method can be adopted. Among these, the spin coating method is preferable from the viewpoint of easily forming a uniform film. In the present specification, “above the module or element” means the light receiving side, that is, the first lens body side. Conversely, the lower side is the substrate 4 side.

  Furthermore, the form which arrange | positions a transparent conductive film using an adhesive agent is mentioned. In this case, a general adhesive is used, but a conductive adhesive may be used.

About this embodiment, although the example which applies the above-mentioned transparent conductive film to the cover glass side lower surface of a light reception layer was given, the surface and side opposite to the lens side of a light reception layer, the wafer substrate surface, It is preferable to apply to a lens body or the like.
Although the thickness of a transparent conductive film is not specifically limited, From a viewpoint of ensuring sufficient transparency and electroconductivity, it is preferable that it is 0.01-100 micrometers, and it is more preferable that it is 0.05-50 micrometers. In the present embodiment, the transparent conductive film is preferably formed as close as possible to the sensor that generates electromagnetic waves, and the film is disposed on the back surface (lower surface) of the cover glass. However, you may arrange | position on the surface (upper surface) of a cover glass as needed for the structure of a module. Lamination of the transparent conductive film as a sandwich structure with a transparent resin is preferable because it can be configured as a form in which electromagnetic wave shielding properties are further improved. Further, as the transparent resin described later, a high refractive index material having good transparency and low light loss is preferable.

[Second Embodiment]
In order to describe another embodiment of the present invention, the example shown in FIG. 3 based on a conventional method for manufacturing a wafer level lens module will be described. In this solid-state imaging device, a lens unit 11 having two lenses is disposed on a light receiving layer 13, and a wafer 14 is positioned below the lens unit 11. These members are initially manufactured as a laminate so as to form a continuous surface on the wafer including the transparent conductive film 5. At this time, the location of the transparent conductive film 5 is not particularly limited, and examples include the surface of the member shown in FIG. 3 or the position of the lower surface of the cover glass (not shown) facing the image sensor (not shown). It is done. Especially, it is preferable that it is the cover glass lower surface (back surface) of the light receiving layer 13 because it is easy to effectively release the accumulated electric charges or to effectively shield external electromagnetic waves.

  Thereafter, a dicing groove having a width w is formed at the cutting position C. The processing method may be a regular method. For example, the lens unit 11 and the light receiving layer 13 may be diced with a normal saw wire, and a cutting process may be performed with a depth that leaves a portion of the wafer 14. Further, a light shielding resin 19 is applied so as to flow into the formed groove of width w. Thereby, each element is isolated by the resin 19 to form a light shielding structure. At this time, an appropriate amount of the light shielding resin 19 is placed outside the upper surface of the lens unit 11 so that stray light from the incident direction of light can be blocked.

  For the structure and manufacturing method of the solid-state imaging device in the wafer level imaging module described above, for example, descriptions in JP 2010-282179 A and JP 2010-56170 A can be referred to. The transparent conductive paint of the present invention is particularly suitable for the production of the wafer level imaging module, but does not prevent application to imaging modules of other systems. For example, JP-A-50-56916 You may apply to the module as described in Unexamined-Japanese-Patent No. 2005-086100, Unexamined-Japanese-Patent No. 2010-251558, Unexamined-Japanese-Patent No. 2010-282179, etc.

[Transparent conductive paint]
In the present invention, the transparent conductive paint contains at least one of conductive metal particles, conductive metal nanowires, conductive oxide particles, and a conductive polymer, and an organic resin. Although the specific material will not be specifically limited if the objective of invention can be achieved, The thing of the embodiment shown below is preferable.
-As 1st Embodiment, what a conductive metal particle is selected from the group which consists of Au, Ag, Cu, and its composite is mentioned.
-As 2nd Embodiment, what a conductive metal nanowire is selected from the group which consists of Au, Ag, and Cu is mentioned.
-As 3rd Embodiment, what a conductive oxide particle is selected from the group which consists of indium, a tin, antimony, aluminum, titanium, and zinc is mentioned.
-As a 4th embodiment, what a conductive polymer is chosen from the group which consists of polyaniline, polypyrrole, and PEDOT (polyethylene dioxythiophene) is mentioned.
More specific embodiments of the metal particles and the like will be described in detail later.

(Organic resin)
The organic resin that can be applied to the transparent conductive paint of the present invention is generally used in paints as long as it is a binder component that can be dissolved in the solvent used, can disperse the conductive components, and can form a film. Any binder component can be used without particular limitation, and as the resin, a resin obtained by curing a photocurable compound, a thermosetting compound, an electron beam curable compound, or the like can be used. Here, the photocurable compound is an organic compound that is cured by light, the thermosetting compound is an organic compound that is cured by heat, and the electron beam curable compound is an electron beam that is a high energy beam. It is an organic compound that cures in Although it does not specifically limit, the following are mentioned. For example, alkyd resin, polyester resin, unsaturated polyester resin, polyurethane resin, acrylic resin, epoxy resin, phenol resin, vinyl resin, silicone resin, fluorine resin, phthalic acid resin, amino resin, polyamide resin, polyacryl silicone resin, polyvinyl Acetal resin, polyurethane resin, melamine resin, urea resin, or binder resin obtained by modifying these can be used alone or in combination of two or more.

  Further, the binder component may contain a cross-linking agent as necessary. For example, basic functional groups such as amino groups, neutral functional groups such as OH groups, acidic functional groups such as carboxyl groups, isocyanate groups Any cross-linking agent having two or more reactive functional groups in one molecule can be used.

  The binder component may be a radical polymerizable monomer, and may be a basic group such as an amino group as long as it is a monomer having a radical polymerizable unsaturated group (α, β-ethylenically unsaturated group). Any of those having a functional group, those having a neutral functional group such as an OH group, those having an acidic functional group such as a carboxyl group, or those not having such a functional group may be used.

  Furthermore, you may mix | blend various conventional additives in the composition for transparent conductive film formation of this invention in the range which does not impair the objective. Examples of such additives include a dispersant, a dispersion aid, a polymerization initiator, a polymerization inhibitor, a curing catalyst, an adhesion aid, an antioxidant, a UV absorber, and a leveling agent.

Below, the specific example of the electroconductive material which makes the transparent conductive paint which can be applied to this invention is given.
(Nanowire / Nanotube)
As used herein, “nanostructure” or “conductive nanostructure” refers to a nanosized structure, at least one dimension of which is less than 500 nm, more preferably 250 nm, 100 nm, 50 nm, or It is less than 25 nm. Nanostructures can be made from any conductive material including metals (eg, transition metals), metal alloys, metal compounds (eg, metal oxides), conductive polymers, conductive carbon nanotubes, and the like. . Typically, nanostructures are made from metallic materials. The metal material can be an elemental metal or a metal compound (eg, a metal oxide). The metal material can be a metal alloy containing two or more types of metals or a material made of two types of metals.

  Nanostructures can have any shape or geometric shape. In certain embodiments, the nanostructure is an isotropic shape (ie, aspect ratio = 1). Typical isotropic nanostructures include nanoparticles. In a preferred embodiment, the nanostructure is an anisotropic shape (ie, aspect ratio ≠ 1). As used herein, aspect ratio refers to the ratio of length and width (or diameter) of nanostructures. Typically, anisotropic nanostructures have a longitudinal axis along their length. Exemplary anisotropic nanostructures include nanowires and nanotubes, as defined herein.

  Nanostructures can be solid or hollow. Solid nanostructures include, for example, nanoparticles and nanowires. “Nanowire” refers to a solid anisotropic nanostructure, as defined herein. Typically, each nanowire has an aspect ratio (length: diameter) greater than 10, preferably greater than 50, more preferably greater than 100. Typically, nanowires have a length greater than 500 nm, or greater than 1 μm, or greater than 10 μm.

  Hollow nanostructures include, for example, nanotubes. “Nanotube” refers to a hollow anisotropic nanostructure, as defined herein. Typically, the nanotubes have an aspect ratio (length: diameter) of greater than 10, preferably greater than 50, more preferably greater than 100. Typically, nanowires have a length greater than 500 nm, or greater than 1 μm, or greater than 10 μm.

  As disclosed in co-pending US patent application Ser. No. 11 / 504,822, the higher the aspect ratio (length: diameter) of the nanostructure, the fewer nanostructures are required to form the conductive network. As used herein, a conductive network refers to a system of interconnected or crossed nanostructures. In this description, the conductive net has a surface resistivity (or “sheet resistance”) of 106 Ω / □ or less. Preferably, the conductive network has a resistivity of 105Ω / □, 104Ω / □, 3,000Ω / □, 1,000Ω / □, and 100Ω / □ or less, or from 100Ω / □ to 1000Ω / □ or 10Ω / □. It has a resistivity of 100Ω / □. In certain preferred embodiments, the conductive network is formed from anisotropic nanostructures such as nanowires, nanotubes, or mixtures thereof. Typically, the conductive net takes the form of a thin film and is also referred to as a “conductive film”. In various embodiments, the thin film has a thickness of about 100 nm to 200 nm, or a thickness of 50 nm to 100 nm, or a thickness of 150 nm to 200 nm.

  Accordingly, one embodiment provides a transparent conductor comprising a substrate and a conductive network on the substrate, the conductive network comprising a plurality of metal nanostructures, wherein the transparent conductor has a contrast ratio greater than 1000. Have In various embodiments, the contrast ratio can be higher than 750, 3000, or higher than 5000. In other embodiments, the transparent conductor has a surface resistivity of less than 1000Ω / □, less than 500Ω / □, less than 100Ω / □, or between 50Ω / □ and 400Ω / □. In other embodiments, the transparent conductor has a haze of less than 5% and a haze of less than 1%. In further embodiments, the transparent conductor has a light transmission greater than 85%, greater than 90%, or greater than 95%.

  Typically, the nanostructures include hollow nanostructures (eg, metal nanotubes), metal nanowires, or combinations thereof. As described herein, nanostructures have specific shapes, dimensions, and materials that can reduce light scattering compared to silver nanowires.

  Nanowires are shown as representative nanostructures and the process applies to nanostructures of all shapes and structures. As an example, nanowires of a first type of metal (for example, silver) are deposited on a substrate. Using a nanowire as a template, a thin coating of a second type of metal (eg, gold) is plated to form a gold-plated nanowire. A selective etch step is then performed to remove the template, i.e. the nanowire. Removal of the nanowire template creates cavities in the coating, thus converting the first type of metal nanowires into a second type of metal hollow nanostructure, ie, nanotubes.

  In general, the thickness of the coating can be in the range of 2-30 nm, or more typically in the range of 5-20 nm. In certain preferred embodiments, the silver nanowires (30-80 nm in diameter) can be plated with a thin layer of gold about 10-20 nm thick. The hollow nanostructure resulting from the etching has a wall thickness that is substantially equal to the coating thickness “d”. Since the coating is thinner than the template nanostructure, less light is scattered from the surface of the hollow nanostructure than the template nanostructure.

  The plating step can be performed, for example, by electroplating, electroless plating, or intermetal displacement. During electroplating, the template nanowires initially deposited on the substrate can be used as a working electrode (ie, cathode) on which the plating metal can be deposited electrochemically. Typically, the plating metal is in its ionic form in the plating bath, which contacts both the template nanowire and the counter electrode (eg, the anode). When current is applied, the plating metal ions move to the cathode and are reduced to elemental metal during deposition on the surface of the template nanowire. Alternatively, the plated metal can be a sacrificial electrode that dissolves in metal ions under current.

  In electroless plating, neither electrode nor current is required. Instead, a reducing agent is used to convert the plated metal (ion type) to its elemental form. For example, the template nanowire can be immersed in a plating solution, and the plating solution includes the ionic plating metal and a reducing agent. Suitable reducing agents for electroless plating are known in the art and include, but are not limited to, formaldehyde, organoboron agents (eg, sodium borohydride, dimethylamine borane), and the like. Plating solutions containing a suitable mix of ion plating metals, suitable reducing agents, and stabilizers are also available from Stapleton Technologies, Inc. (Long Beach, CA). For example, Stapleton® Micro 291 is a commercial gold plating solution suitable for plating metals such as silver, nickel, copper and the like.

  Depending on the relative activities of the metal forming the template nanostructure and the plating metal, direct or spontaneous intermetallic displacement provides yet another plating methodology. In the intermetal displacement reaction, a highly reactive metal can replace the ionic form of a less reactive metal. Thus, when the template nanowire is made from a highly reactive metal, when the template nanowire contacts a less reactive metal ion, the less reactive metal is converted to elemental metal, while the more reactive metal The metal is converted into ions. For example, when using silver nanowires as a template, a thin layer of gold combines a silver nanowire and a gold salt comprising a monovalent salt (eg, ammonium sulfite gold) and a trivalent salt (eg, tetrachloroauric acid). Thus, it is possible to plate on each template nanowire. A valent gold salt is typically preferred because it replaces silver atoms in a 1: 1 ratio, while a trivalent gold salt replaces three silver atoms per gold atom. The silver nanowires erode (ie convert to silver ions), but a gold coating is formed on the remaining silver nanowires. The evolution of the displacement response is controllable so that the silver nanowires can be partially or completely replaced by gold.

Selective etching removes the template nanostructure of the first type of metal without etching the metal coating of the second type of metal. Etching can be performed chemically with an etchant. The etching solution is not particularly limited as long as one metal is distinguished and etched, and the other metal is left. For example, the silver nanowire template can be removed with any silver etchant, which includes nitric acid (HNO ₃ ), ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ), and the like. However, it is not limited to these. Optionally, an oxidizing agent can also be presented to initially convert silver to silver oxide, which is further dissolved by nitric acid. An exemplary oxidizing agent is potassium permanganate (KMnO ₄ ).

  As an alternative to chemical etching, electrolytic nano-etching can be used to remove template nanostructures. During electrolytic etching, the template nanostructure is made an anode and contacts the electrolyte. The counter electrode (ie, the cathode) is also immersed in the electrolyte. Selective etching is achieved by controlling the voltage applied to the electrodes. The voltage must be higher than the oxidation potential of the first type metal (for template nanostructure) and lower than the oxidation potential of the second type metal (for plating metal). At such a voltage, the template nanostructure can be selectively etched as a sacrificial electrode, but the plated metal is not affected. For example, when etching silver from gold coated silver nanowires, the applied voltage is typically about 0.8 V, which is higher than the electrochemical potential to oxidize silver, but oxidizes gold. Lower than the electrochemical potential. As a result, only silver nanowires are etched.

  Based on the above description of the various methods of plating and etching, it should be recognized that any reasonable combination of plating and etching is feasible. For example, template nanostructures can be electroplated and chemically etched, electroplated and electrolytically etched, electrolessly plated and electrolytically etched, and the like.

  In certain embodiments, ink dispersion of nanostructures (eg, hollow nanostructures such as gold nanotubes, or metal nanowires such as silver nanowires or plated silver nanowires) can be added to control viscosity, adhesion, and nanowire dispersion. Agents and binders can be included. Examples of suitable additives and binders include carboxymethylcellulose (CMC), 2-hydroxyethylcellulose (HEC), hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), Propylene glycol (TPG) and xanthan gum (XG), and surfactants such as ethoxylates, alkoxylates, ethylene oxide, and propylene oxide, and copolymers thereof, and sulfonates, sulfates, disulfonates, sulfosuccinic acids Salts, phosphate esters, fluorosurfactants (eg, DuPont's Zonyl®), but are not limited to these.

  In one example, “ink” includes 0.0025 wt% to 0.1 wt% surfactant (eg, for Zonyl® FSO-100, a preferred range is 0.0025 wt% to 0.00 wt%. 05 weight percent), 0.02 weight percent to 4 weight percent viscosity modifier (eg, for HPMC, the preferred range is 0.02 weight percent to 0.5 weight percent), from 94.5 weight percent Up to 99.0% by weight of solvent and 0.05% to 1.4% by weight of metal nanostructures (eg hollow nanostructures such as gold nanotubes, or metal nanowires such as silver or plated silver nanowires) included. Representative examples of suitable surfactants include Zonyl (R) FSN, Zonyl (R) FSO, Zonyl (R) FSH, Zonyl (R) FFA, Triton (x100, x114, x5), Dynol (604, 607), n-dodecyl bD-maltoside, and Novec. Examples of suitable viscosity modifiers include hydroxypropyl methylcellulose (HPMC), methylcellulose, xanthan gum, polyvinyl alcohol, polyvinylpyrrolidone, carboxymethylcellulose, hydroxyethylcellulose. Examples of suitable solvents include water and isopropanol.

  When it is desired to change the concentration of the ink dispersion from the concentration disclosed above, the ratio of the solvent can be increased or decreased. However, in a preferred embodiment, the relative proportions of the remaining components can remain the same. Specifically, the ratio of surfactant to viscosity modifier is preferably in the range of about 80 to about 0.01, and the ratio of viscosity modifier to metal nanostructure is preferably about 5 To about 0.000625, and the ratio of metal nanostructure to surfactant is preferably in the range of about 560 to about 5. The ratio of the components of the dispersion may be modified depending on the substrate and the method of application used. A suitable viscosity for the nanostructure dispersion is between about 1 cP and 100 cP.

  Depending on the dimensions of the nanostructure and the load density, the conductive network can be optically transparent. Typically, the optical transparency and clarity of a transparent conductor can be quantitatively defined by parameters including light transmission and haze. “Light transmissive” refers to the fraction of incident light that is transmitted through the medium. Incident light refers to visible light having a wavelength between about 400 nm and 700 nm. In various embodiments, the light transmission of the transparent conductor is at least 50%, at least 60%, at least 70%, at least 80%, or at least 85%, at least 90%, or at least 95%. Haze is an indicator of light diffusion. This refers to the proportion of the amount of light that is separated from the incident light and scattered during transmission (ie, transmission haze). Unlike light transmission, which is primarily a property of the medium, haze is often related to production and is typically caused by surface roughness and embedded particles or component inhomogeneities in the medium. In various embodiments, the haze of the transparent conductor is 10% or less, 8% or less, 5% or less, or 1% or less. Typically, the higher the haze value, the lower the contrast ratio. In various embodiments, the contrast ratio of the transparent conductor is greater than 750, greater than 1,000, greater than 2,000, greater than 3,000, greater than 4,000, or greater than 5,000.

  The conductive film formed by the hollow nanostructure is chemically and thermally stable. As demonstrated in Example 12, the optical and electrical properties of the conductive film were substantially unchanged after prolonged exposure to heat and chemicals. When a conductive film is exposed to external factors such as heat or chemicals, its resistivity does not vary by more than 30%, or more than 5%, or more preferably, more than 1% In addition, the conductive film is considered to be stable. Thus, certain embodiments provide a transparent conductor film comprising a hollow nanostructure, the transparent conductor film having a light transmission higher than 85%, a haze lower than 1%, and a resistivity lower than 1500Ω / □. And resistivity does not change more than 1% upon exposure to heat or chemical agents.

(ITO film)
In the present invention, it is also preferable to use ITO particles as a material for forming the transparent conductive film. As the ITO (tin-doped indium oxide) particles, the same particles as those usually used in the technical field can be used without particular limitation. For example, ITO particles are precipitated by adding an alkaline aqueous solution to an acidic aqueous solution containing an indium salt and a tin salt to precipitate a coprecipitated hydroxide, washing, solid-liquid separation, and then in a slightly reducing atmosphere at 300 to 1000 ° C. It can be obtained by performing primary firing of the coprecipitated hydroxide, followed by secondary firing at 600 to 1000 ° C. in a slightly reducing atmosphere or inert atmosphere. The ITO particles produced by such a method have oxygen deficiency due to the production method. This oxygen deficiency contributes to increasing the conductivity of the ITO nanoparticles.
The ITO nanoparticles preferably have a primary average particle size of 100 nm or less. The average particle size of the ITO powder is 100 nm or less. When the ITO powder is dispersed in the film, most of the light scattered through the film is in the so-called Rayleigh scattering or Mie scattering mode, and the transparency of the object is extremely high. This is because the haze value also falls to 3% or less of the practical level. It is preferable to contain 1 to 15% by weight of ITO powder in the electric field shielding treatment liquid.
The polar solvent may be any one having an appropriate boiling point below the firing temperature and capable of efficiently dispersing the ITO particles. For example, N-methyl-2-pyrrolidinone and methanol, ethanol, isopropyl alcohol, dimethylform, and the like. Preferred examples include a mixed solution with amide (DMF), dimethylacetamide, methyl cellosolve, diacetone alcohol, acetone, tetrahydroxyfuran, propylene glycol monomethyl ether acetate and the like. N-methyl-2-pyrrolidinone is used for promoting dispersion of the ITO powder, and is preferably contained in the electric field shielding treatment liquid in an amount of 1 to 20% by weight.

  In the present invention, it is also preferable to use a conductive polymer as a material for forming the transparent conductive film. For example, a conjugated polymer such as polyacetylene polymer, polyphenylene polymer, heterocyclic polymer, and ionic polymer polymer can be used. Examples of the polyacetylene polymer include polyacetylene and polyphenylacetylene. Examples of the polyphenylene polymer include polyparaphenylene and polyphenylene vinylene. Examples of the heterocyclic polymer include polypyrrole, PEDOT (polyethylenedioxythiophene), and the like. Examples of the ionic polymer polymer include polyaniline.

  In the present invention, the transparent conductive film may be formed using a technique using a metal mesh having an opening. Materials and methods include conductive fiber, electroless plating mesh, etching mesh using photolithography method, conductive metal silver pattern using silver salt, mesh printed with silver paste, irregular mesh silver There are methods such as mesh.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not construed as being limited thereto.

Example 1
The material shown in Table 1 was applied to a glass wafer as a substrate (Corning 1737, manufactured by Corning) by a spin coating method to obtain a transparent conductive film. The transmittance | permeability measurement of the transparent pattern was performed for the obtained film | membrane using the spectrophotometer U-4100 (brand name, Hitachi Ltd. make). The surface resistance was measured by Loresta HP MCP-T410 (trade name, manufactured by Mitsubishi Chemical Analytech).
<Applicability evaluation>
The results of visual evaluation of the appearance of the transparent conductive film obtained above are shown in Table 1. The following was used as the evaluation score.
5: No film unevenness 4: Almost no film unevenness 3: There is film unevenness but can be evaluated 2: There is film unevenness and evaluation is difficult 1: There is film unevenness and cannot be evaluated

  Compared with the comparative example, it can be confirmed that a good film having both transparency and conductivity is obtained, and is a material suitable as an electromagnetic shielding material.

The following samples were used for each sample in the table.
ITO nanoparticles A: manufactured by SIGMA-Aldrich, trade name: 700460, primary particle size 100 nm
ITO nanoparticle B: primary particle size 25 nm, Sn doping ratio 10%
ITO nanoparticle C: primary particle size 5 nm, Sn doping ratio 10%
Silver (Ag) nanowires were synthesized by reduction of silver nitrate dissolved in ethylene glycol in the presence of polyvinylpyrrolidone (PVP). The average minor axis length was 30 nm, and the average major axis length was 10 μm. The amount (mass%) of each silver nanowire, PVP (polyvinylpyrrolidone), and IPA (isopropyl alcohol) is as follows.
Ag-NW PVP IPA
104 0.76% 0.76% 99.24%
105 0.30% 0.30% 99.39%
・
PEDOT / PSS: SIGMA-Aldrich, trade name: 483095,
PVP: Polyvinylpyrrolidone IPA: Isopropyl alcohol

(Example 2)
Table 2 shows the results of a heat resistance test performed on the transparent conductive film obtained above using a hot plate. The following was used as the evaluation score.

<Heat resistance evaluation>
4 With heat of 260 ° C, change in conductivity within 5% 3 With heat at 200 ° C, change in conductivity within 5% 2 With heat at 150 ° C, change in conductivity within 5% 1 Heat at 100 ° C And within 5% change in conductivity

  It was confirmed that a transparent conductive film excellent in practical heat resistance could be produced.

DESCRIPTION OF SYMBOLS 1a 1st lens body 1b 2nd lens body 2 Outer frame 3 Light receiving layer 4 Base material (wafer)
DESCRIPTION OF SYMBOLS 5 Transparent conductive film 9 Coating film 10 of light-shielding coating material Solid-state image sensor 10a Solid-state image sensor precursor 11 Lens unit (comparative example)
13 Light-receiving layer (Comparative example)
14 Wafer (Comparative example)
19 Shading resin (comparative example)
B WLL shading material w Dicing width (comparative example)

Claims (13)

  A method for producing a solid-state imaging device having a transparent conductive film on an inner member surface, the transparent conductive film containing at least one of conductive metal particles, conductive metal nanowires, conductive oxide particles, and conductive polymers A method for producing a solid-state imaging device, wherein a conductive film is disposed on the internal member.   The manufacturing method of the solid-state image sensor of Claim 1 including the process of dicing the member laminated body provided on the wafer after the process of arrange | positioning a transparent conductive film to the said member.   The manufacturing method of the solid-state image sensor of Claim 1 or 2 by a wafer level process.   The method for manufacturing a solid-state imaging device according to claim 1, wherein the conductive metal particles are selected from the group consisting of Au, Ag, Cu, and a composite thereof.   The manufacturing method of the solid-state image sensor of any one of Claims 1-4 in which the said electroconductive metal nanowire is selected from the group which consists of Au, Ag, and Cu.   The method for manufacturing a solid-state imaging element according to claim 1, wherein the conductive oxide particles are selected from the group consisting of indium, tin, antimony, aluminum, titanium, and zinc.   The method for manufacturing a solid-state imaging device according to claim 1, wherein the conductive polymer is selected from the group consisting of polyaniline, polypyrrole, and PEDOT (polyethylenedioxythiophene).   The manufacturing method of a camera module which has the process of producing a solid-state image sensor with the manufacturing method of any one of Claims 1-7, and the process of modularizing this. A transparent conductive film formed on the surface of the internal member of the solid-state imaging device by the manufacturing method according to claim 1,
A transparent conductive film containing at least one of conductive metal particles, conductive metal nanowires, conductive oxide particles, and a conductive polymer.   A solid-state imaging device comprising the transparent conductive film according to claim 9.   A camera module comprising the solid-state imaging device according to claim 10.   Use of the transparent conductive film according to claim 9 as an electromagnetic wave shielding film. A transparent conductive paint disposed on the surface of an internal member of a solid-state imaging device to form a transparent conductive film,
A transparent conductive paint for a solid-state imaging device, containing at least one of conductive metal particles, conductive metal nanowires, conductive oxide particles, and a conductive polymer.

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