Composite photosensitive structure and method for manufacturing the same

Abstract

A composite photosensitive structure and a method for preparing the same, the composite photosensitive structure comprising a photosensitive element and a near-infrared absorbing layer formed on the photosensitive element, wherein the near-infrared absorbing layer comprises a copper complex formed by a copper compound for providing copper ions, a phosphonic acid as shown in formula 1 herein, and at least one phosphorus-containing compound as shown in formula 2 to 4 herein, and the OD value of the near-infrared absorbing layer to the wavelength of 930 nm to 950 nm incident light is greater than 4. The present application replaces the traditional filter assembly by directly forming a filter film on the photosensitive element, thereby reducing the size of the finished product after assembly; the filter film can also be further processed and shaped to have a microlens function.

Description

Technical Field

[0001] This invention relates to a composite photosensitive structure, and more particularly to a composite photosensitive structure comprising a photosensitive element and a near-infrared absorbing layer formed thereon. Background Technology

[0002] A typical photosensitive element generally comprises components such as microlenses, a color filter layer, a photoelectric conversion layer, and driving circuitry. It can be fabricated on a wafer as a photosensitive element array through multiple photolithography processes, followed by dicing to form the photosensitive element. The photoelectric conversion layer is sensitive not only to visible light but also to a portion of near-infrared light; that is, it detects a broad wavelength range including both visible light and some near-infrared radiation. However, the electrical signal generated by detecting near-infrared light is considered interference, interfering with the display of normal images. Therefore, it is desirable to effectively filter out infrared light from entering the photoelectric conversion layer. Historically, this was typically achieved by placing a separate external near-infrared filter on the light-incident side when assembling the photosensitive element into an optical lens.

[0003] However, with increasingly higher demands for image quality, the problems of using external filters to filter out near-infrared light have gradually emerged. Besides the insufficient visible light transmittance of external near-infrared filters, which reduces the amount of incident light to the photoelectric conversion layer, there is also the issue of excessively large optical lenses resulting from the space required to install external filters. This leads to the prevalent outward protrusion of lenses in current mobile phones, even high-end models, increasing the risk of bumps and damage. In the trend towards miniaturization and thinning of components, the well-known optical lenses with external near-infrared filters have limited significant progress due to the aforementioned limitations.

[0004] Furthermore, in the near-infrared absorption filter process, the near-infrared absorption layer is usually formed first and then the anti-reflective coating is deposited. However, the current coating process for forming the anti-reflective layer operates at temperatures as high as 200℃-300℃, which makes the organic dyes in the near-infrared absorption layer prone to decomposition or loss of activity due to high temperatures. Therefore, there are significant limitations in the selection of organic dyes and the adjustment and control of coating process parameters. Summary of the Invention

[0005] To address the aforementioned problems, the present invention provides a composite photosensitive structure comprising:

[0006] Photosensitive element; and

[0007] A near-infrared absorbing layer is formed on a photosensitive element, wherein the near-infrared absorbing layer comprises a copper complex, the copper complex being formed by a copper compound for providing copper ions, a phosphonic acid as shown in Formula 1, and at least one phosphorus-containing compound as shown in Formulas 2 to 4.

[0008]

[0009] Wherein, R, R1, R2, and R3 are each independently substituted or unsubstituted C1 to C2. 12 Alkyl or C6 to C 12 Aryl,

[0010] Among them, the near-infrared absorption layer has an OD value greater than 4 for incident light wavelengths from 930nm to 950nm.

[0011] In one embodiment, the photosensitive element is a charged-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) sensor.

[0012] In one embodiment, substituted or unsubstituted C1 to C 12 The alkyl group is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, and tert-butyl; substituted or unsubstituted C6 to C6 alkyl groups. 12 The aryl group is selected from the group consisting of phenyl, naphthyl, and chlorophenyl.

[0013] In one embodiment, the near-infrared absorbing layer has a haze of less than 0.4%.

[0014] In one embodiment, the X-ray photoelectron spectrum of the near-infrared absorbing layer has at least one main peak at a binding energy of 930 eV to 940 eV. In another embodiment, the counts per second of at least one main peak in the X-ray photoelectron spectrum of the near-infrared absorbing layer is 4500 or more.

[0015] In one embodiment, the thickness of the near-infrared absorption layer is 25 μm to 150 μm.

[0016] In one embodiment, the near-infrared absorbing layer further comprises an optical resin, which is a thermoplastic resin and / or a photocurable resin. In another embodiment, the optical resin is selected from polycarbonates, polyesters, polycyclic olefins, polyacrylic acids, silicone resins, and polyimides. In yet another embodiment, the optical resin is methyl methacrylate.

[0017] In one embodiment, a copper compound, a phosphonic acid as shown in Formula 1, and at least one phosphorus-containing compound as shown in Formulas 2 to 4 are mixed with a solvent to form a dispersion containing a copper complex, and the dispersion is mixed with an optical resin in a weight ratio of 5:1 to 1:1 to form a near-infrared absorbing layer.

[0018] In one embodiment, the photosensitive element includes a plurality of photosensitive areas, and a near-infrared absorption layer is formed on each photosensitive area, wherein the boundary of the near-infrared absorption layer is flush with or extends beyond the boundary of the photosensitive area.

[0019] In one embodiment, the near-infrared absorbing layer has a first surface and a second surface opposite to each other, wherein the second surface contacts the surface of the photosensitive area, and the first surface is planar, convex or concave.

[0020] In one embodiment, the near-infrared absorption layer serves as a microlens.

[0021] The present invention further provides a method for preparing a composite photosensitive structure, comprising:

[0022] Prepare a copper compound for providing copper ions, a phosphonic acid as shown in Formula 1, at least one phosphorus-containing compound as shown in Formulas 2 to 4, and form a coating solution containing a copper complex.

[0023]

[0024] Among them, R, R1, R2, and R3 are each independently substituted or unsubstituted C1 to C3. 12 Alkyl or C6 to C 12 Aryl;

[0025] The coating solution is applied to a wafer containing a photosensitive element array and cured to form a near-infrared absorption layer; and

[0026] The wafer is cut to obtain a composite photosensitive structure.

[0027] Among them, the near-infrared absorption layer has an absorbance OD value greater than 4 for incident light wavelengths from 930nm to 950nm.

[0028] In one embodiment, the photosensitive element is a photocoupler or a complementary metal-oxide-semiconductor sensor.

[0029] In one embodiment, substituted or unsubstituted C1 to C 12 The alkyl group is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, and tert-butyl; substituted or unsubstituted C6 to C6 alkyl groups. 12 The aryl group is selected from the group consisting of phenyl, naphthyl, and chlorophenyl.

[0030] In one embodiment, the near-infrared absorbing layer has a haze of less than 0.4%.

[0031] In one embodiment, the X-ray photoelectron spectrum of the near-infrared absorbing layer has at least one main peak at a binding energy of 930 eV to 940 eV. In another embodiment, the count value per second of at least one main peak in the X-ray photoelectron spectrum of the near-infrared absorbing layer is 4500 or more.

[0032] In one embodiment, the thickness of the near-infrared absorption layer is 25 μm to 150 μm.

[0033] In one embodiment, the step of forming a coating solution containing a copper complex includes adding a copper compound, phosphonic acid, and a phosphorus-containing compound to a solvent and mixing to form a dispersion. In another embodiment, the weight ratio of the total amount of the copper compound, phosphonic acid, and phosphorus-containing compound to the solvent is 1:5 to 1:1. In yet another embodiment, the step of forming a coating solution containing a copper complex further includes mixing the dispersion with an optical resin to form a coating solution. In yet another embodiment, the weight ratio of the dispersion to the optical resin is 5:1 to 1:1.

[0034] In one embodiment, the optical resin is a thermoplastic resin and / or a photocurable resin. In another embodiment, the optical resin is selected from polycarbonates, polyesters, polycyclic olefins, polyacrylic acids, silicone resins, and polyimides. In yet another embodiment, the optical resin is methyl methacrylate.

[0035] In one embodiment, the curing step uses light curing, and the coating liquid is dried to remove solvent before curing.

[0036] In one embodiment, the method for preparing the composite photosensitive structure of the present invention further includes patterning a near-infrared absorption layer using a photolithography process.

[0037] This invention first prepares a coating liquid capable of forming a near-infrared absorbing layer that efficiently absorbs incident light with wavelengths from 800 nm to 1100 nm, and more particularly, excellently absorbs incident light with a wavelength of 940 nm, while exhibiting high transmittance for visible light. This liquid is then directly coated onto a photosensitive element to form the near-infrared absorbing layer, thereby creating a composite photosensitive structure. Optical lenses using this composite photosensitive structure can achieve excellent near-infrared cutoff without the need for a separate external near-infrared filter, and the thickness of the optical lens can be significantly reduced. Furthermore, by introducing a photolithography process during the formation of the near-infrared absorbing layer, the near-infrared absorbing layer can be given a specific shape, such as a convex lens or a concave lens. Therefore, the near-infrared absorbing layer can also function as a microlens, further reducing the thickness of the optical lens. Attached Figure Description

[0038] Figures 1 to 4 This is a schematic diagram of the process for preparing the composite photosensitive structure according to the present invention.

[0039] Figures 5 to 7 This is a schematic diagram of another method for preparing the composite photosensitive structure according to the present invention.

[0040] Figure 8 X-ray photoelectron spectroscopy was used to prepare the near-infrared absorbing layer in Example 1.

[0041] Explanation of main component symbols

[0042] 1,1' composite photosensitive structure

[0043] 10 wafers

[0044] 11 Photosensitive Area

[0045] 12 Photosensitive elements

[0046] 20 Coating liquid

[0047] 21,21',21” Near-infrared absorption layer

[0048] C Cutting tools

[0049] L light source

[0050] M-mask. Detailed Implementation

[0051] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand the scope and effects of the present invention based on the content described herein.

[0052] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying diagrams are only for the purpose of assisting those skilled in the art in understanding and reading the content described herein, and are not intended to limit the conditions under which the art can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, as long as they do not affect the resulting effects and the objectives achieved, should still fall within the scope of the described technical content. Similarly, terms such as "above," "first," and "second" used in this specification are only for clarity and are not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of implementation.

[0053] When the terms "including," "comprise," or "have" a specific element are used in this document, unless otherwise stated, they may include other elements, components, structures, regions, locations, devices, systems, steps, or connections, rather than excluding such other elements.

[0054] Unless otherwise expressly stated herein, the singular forms “a” and “the” used herein also include the plural forms, and the terms “or” and “and / or” used herein are interchangeable.

[0055] The numerical ranges described herein are inclusive and can be combined. Any value falling within the numerical ranges described herein can be used as the maximum or minimum value to derive its sub-ranges. For example, the numerical range of "25 to 200" should be understood to include any sub-range between the endpoint 25 and the endpoint 200, such as 25 to 150, 30 to 200, 30 to 150, etc. Furthermore, if a value falls within any of the ranges described herein (such as between the maximum and minimum values), it should be considered to be included within the scope of this invention.

[0056] A first aspect of the present invention is a composite photosensitive structure comprising: a photosensitive element; and a near-infrared absorbing layer formed on the photosensitive element.

[0057] For photosensitive elements, any element that can interact with incident light and generate a signal is included within the scope of this invention, including but not limited to photocoupler CCD or complementary metal-oxide-semiconductor sensor CMOS.

[0058] Formed on the photosensitive element, specifically, the near-infrared absorption layer directly contacts the photosensitive element. That is, any method that enables direct contact between the two is covered within the scope of this invention. For example, a near-infrared absorption layer precursor is formed on the surface of the photosensitive element, and the near-infrared absorption layer precursor is further processed to become a near-infrared absorption layer; the near-infrared absorption layer is attached to the surface of the photosensitive element with or without adhesive, etc.

[0059] The near-infrared absorbing layer of the present invention comprises: a copper complex formed by a copper compound for providing copper ions, a phosphonic acid as shown in Formula 1, and at least one phosphorus-containing compound as shown in Formulas 2 to 4.

[0060]

[0061] Among them, R, R1, R2, and R3 are each independently substituted or unsubstituted C1 to C3. 12 Alkyl or C6 to C 12 Aryl.

[0062] Copper complexes can be chemically formulated as Cu 2+ X represents, where Cu 2+ X is provided by copper compounds; X is contributed by phosphonic acids and / or phosphorus-containing compounds.

[0063] Alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl, etc., and substituted alkyl groups include, but are not limited to, haloalkyl, hydroxyalkyl, nitroalkyl, alkoxyalkyl, etc. Aryl groups include, but are not limited to, phenyl, naphthyl, etc., and substituted aryl groups include, but are not limited to, haloaryl (e.g., chlorophenyl), nitroaryl, hydroxyaryl, alkoxyaryl, alkylaryl, haloalkylaryl, nitroalkylaryl, hydroxyalkylaryl.

[0064] In one embodiment, the phosphonic acid is butylphosphonic acid.

[0065] The copper compound used to provide copper ions primarily serves as a source of copper ions. Known copper compounds that provide copper ions can be used, such as copper salts, including copper acetate or copper acetate hydrate, as well as copper chloride, copper formate, copper stearate, copper benzoate, copper pyrophosphate, copper naphthenate, and anhydrides or hydrates of copper citrate. In one embodiment, the copper compound used to provide copper ions is copper acetate.

[0066] Phosphorus-containing compounds can have a dispersing function, preventing the components in the composition (including the formed copper complex) from agglomerating and achieving uniform dispersion. One benefit of this function is that it can result in crystallite sizes below 100 nm, more specifically between 5 nm and 80 nm, or between 20 nm and 60 nm, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, and 100 nm. When the crystallite size is above 5 nm, it exhibits sufficient near-infrared absorption characteristics; while when the crystallite size is below 100 nm, the particles are all agglomerated and have small particle sizes, resulting in products with low haze.

[0067] The copper complex of the present invention can be prepared from a near-infrared absorbing composition. The near-infrared absorbing composition includes the aforementioned copper compound, phosphonic acid, and a phosphorus-containing compound. The components interact and react with each other to form a copper complex. In this invention, the proportions of each component can be adjusted as needed. For example, in the near-infrared absorbing composition, the copper compound used to provide copper ions can be 150 parts by weight, and examples include 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, or 150 parts by weight; the phosphonic acid can be 100... The parts by weight may be listed as 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 parts by weight; and the total amount of phosphorus-containing compounds may be from 1 to 90 parts by weight, listed as 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 parts by weight.

[0068] In one embodiment, the near-infrared absorbing composition also includes phosphorus-containing compounds represented by Formulas 2 to 4, which can be adjusted in proportion as needed. For example, in the near-infrared absorbing composition, the phosphorus-containing compound represented by Formula 2 can be 1 to 90 parts by weight, the phosphorus-containing compound represented by Formula 3 can be 1 to 90 parts by weight, and the phosphorus-containing compound represented by Formula 4 can be 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 parts by weight. In another embodiment, the ratio of the phosphorus-containing compound represented by Formula 2: the phosphorus-containing compound represented by Formula 3: the phosphorus-containing compound represented by Formula 4 is 20:20:50.

[0069] In one embodiment, the near-infrared absorbing composition may be in the form of a dispersion, that is, in addition to the copper compound, phosphonic acid, and phosphorus-containing compound, it further includes a solvent. During formulation, the copper compound, phosphonic acid, and phosphorus-containing compound may be added to and mixed with the solvent, and the ratio of these components to the solvent may be from 1:5 to 1:1, for example, 1:3, but is not limited thereto.

[0070] Solvents may be selected from known solvents, including but not limited to water, alcohols, ketones, ethers, esters, aromatic hydrocarbons, halogenated hydrocarbons, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, sulfolane, etc. Specifically, alcohols include, for example, methanol, ethanol, propanol, etc. Esters include, for example, alkyl formate esters, alkyl acetate esters, alkyl propionate esters, alkyl butyrate esters, alkyl lactate esters, alkyl alkoxyacetic acid esters, alkyl 3-alkoxypropionate esters, alkyl 2-alkoxypropionate esters, alkyl 2-alkoxy-2-methylpropionate esters, alkyl pyruvate esters, alkyl acetoacetate esters, alkyl 2-oxobutyrate esters, etc. Ethers, such as diethylene glycol dimethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, etc. Ketones, such as methyl ethyl ketone, cyclohexanone, cyclopentanone, 2-heptanone, 3-heptanone, etc. Aromatic hydrocarbons, such as toluene, xylene, etc.

[0071] Mix, for example, at room temperature (e.g., 25°C), for example, for more than 4 hours, more than 6 hours, more than 8 hours, but not limited to this.

[0072] In this invention, the near-infrared absorbing composition in the form of a dispersion can be mixed with an optical resin to form a near-infrared absorbing composition in the form of a coating liquid, for subsequent formation of a near-infrared absorbing layer. The ratio of the dispersion to the optical resin can be 5:1 to 1:1 or 3:1 to 1:1, for example 0.65:0.35, but is not limited thereto. When using the near-infrared absorbing composition in the form of a coating liquid, it is formed on a substrate and dried and cured to form a near-infrared absorbing layer.

[0073] The optical resin can be a thermoplastic resin and / or a photocurable resin. In one embodiment, the optical resin is selected from polycarbonates, polyesters, polycyclic olefins, polyacrylic acids, silicone resins, and polyimides. In another embodiment, the optical resin is a silicone resin. In yet another embodiment, the optical resin is methyl methacrylate.

[0074] In one embodiment, the near-infrared absorbing composition may be further supplemented with a polymerization initiator, such as a photopolymerization initiator, so that the optical resin can be polymerized by light irradiation. Known polymerization initiators, including but not limited to azobisisobutyronitrile (AIBN), may be used. In one embodiment, a solvent may also be added to facilitate uniform mixing; those known to the public, including but not limited to those mentioned herein, may be used. In one embodiment, to facilitate the curing process, a curing agent, such as a photocuring agent, may be further added, so that the film can be cured by light irradiation.

[0075] In one embodiment, to further improve the optical performance of the near-infrared absorption layer, for example, to further enhance the cutoff of near-infrared and ultraviolet rays, it may also include an absorbing dye. In one embodiment, the absorbing dye includes a near-infrared absorbing dye and / or an ultraviolet absorbing dye.

[0076] Near-infrared absorbing dyes, such as azo compounds, diimide compounds, dithiophenol metal complexes, squaraine compounds, cyanine compounds, and phthalocyanine compounds, can have their maximum absorption wavelength tuned to between 650 and 1100 nm, or more specifically, between 650 and 750 nm. Ultraviolet absorbing dyes include azomethine compounds, indole compounds, ketone compounds, benzimidazole compounds, and triazine compounds.

[0077] In one embodiment, to maintain better light transmittance, the near-infrared absorption layer has a haze of less than 0.4%, 0.3%, or 0.2%, for example, 0.4%, 0.35%, 0.3%, 0.25%, 0.2%, 0.19%, 0.18%, 0.17%, 0.16%, 0.15%, 0.14%, 0.13%, 0.12%, 0.11%, or 0.1%.

[0078] The thickness of the near-infrared absorption layer also affects the near-infrared absorption characteristics. Generally speaking, increasing the thickness of the near-infrared absorption layer increases the near-infrared cutoff capability, but this does not meet the requirements for thinner designs. Conversely, decreasing the thickness of the near-infrared absorption layer reduces the near-infrared cutoff capability. In one embodiment, the near-infrared absorbing layer of the present invention can achieve excellent near-infrared cutoff capability even when it is very thin. Specifically, the thickness of the near-infrared absorbing layer is between 25 μm and 150 μm, between 50 μm and 150 μm, or between 100 μm and 150 μm, for example, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm, 146 μm, 147 μm, or 150 μm.

[0079] In one embodiment, the X-ray photoelectron spectrum of the near-infrared absorption layer of the present invention has at least one main peak when the binding energy is between 930 electron volts and 940 electron volts. In one embodiment, the count value per second of the at least one main peak is 4500 or more, 4600 or more, 4700 or more, 4800 or more, 4900 or more, or 5000 or more.

[0080] In one embodiment, the maximum transmittance of the near-infrared absorption layer of the present invention for incident light wavelengths in the range of 930 nm to 950 nm (including incident light at 940 nm) is less than 0.1%, less than 0.1%, less than 0.05%, less than 0.05%, less than 0.01%, less than 0.01%, less than 0.0005%, or less than 0.005%, for example, 0.1%, 0.09%, 0.08%, 0.07%, 0.06%, 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, 0.009%, 0.008%, 0.007%, etc. 0.006%, 0.005%, 0.004%, 0.003%, 0.002%, 0.001%; ​​on the other hand, the OD value for the incident light wavelength range of 930nm to 950nm (including incident light at 940nm) is 3 or more, greater than 3, 3.5 or more, greater than 3.5, 4 or more, greater than 4, 4.5 or more, or greater than 4.5, for example, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9. In one embodiment, the near-infrared absorption layer of the present invention has a minimum transmittance of 80% or more or 85% or more for the incident light wavelength range of 460nm to 560nm, for example 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89% or 90%.

[0081] In one embodiment, the near-infrared absorbing layer has a passband that overlaps with wavelength ranges of 300 nm to 850 nm, 300 nm to 800 nm, or 350 nm to 750 nm, and the center wavelength of the passband lies within the wavelength ranges of 300 nm to 850 nm, 300 nm to 800 nm, 350 nm to 750 nm, 400 nm to 700 nm, 450 nm to 650 nm, 500 nm to 600 nm, or 500 nm to 550 nm. Herein, a "passband" refers to a segment where the transmittance of incident light within the wavelength range is 50% or higher, and the "center wavelength of the passband" is the average of the two incident light wavelengths corresponding to an incident light transmittance of 50%.

[0082] In one embodiment, when incident light irradiates the near-infrared absorption layer of the present invention at incident angles of 0 degrees and 30 degrees, respectively, the center wavelength of the passband is shifted by an amount less than 1.4 nm, such as 1.4 nm, 1.3 nm, 1.2 nm, or 1.1 nm. In another embodiment, when incident light irradiates the near-infrared absorption layer of the present invention at incident angles of 0 degrees and 35 degrees, respectively, the center wavelength of the passband is shifted by an amount less than 1.9 nm, such as 1.9 nm, 1.8 nm, or 1.7 nm.

[0083] In the composite photosensitive structure of the present invention, the photosensitive element may include multiple photosensitive regions, and a near-infrared absorption layer is formed on each photosensitive region. For example, the photosensitive element is an uncuttered wafer having multiple photosensitive units, where each photosensitive unit is the photosensitive region referred to herein. The near-infrared absorption layer is formed on the entire wafer and may undergo further processing. More specifically, the near-infrared absorption layer may contact one or more photosensitive units. In one embodiment, the boundary of the near-infrared absorption layer is flush with or extends beyond the boundary of the photosensitive region to ensure that infrared light is blocked by the near-infrared absorption layer and does not leak into the photosensitive region below.

[0084] In one embodiment, the near-infrared absorption layer of the composite photosensitive structure of the present invention has a first surface and a second surface, wherein the second surface of the near-infrared absorption layer contacts the surface of the photosensitive area, and the first surface of the near-infrared absorption layer is planar, convex, or concave. Here, the near-infrared absorption layer can be processed to make the first surface planar, convex, or concave, for example, through etching, laser cutting, grinding, photolithography, etc., and the processing can be performed before, simultaneously with, or after the near-infrared absorption layer is formed on the photosensitive area. A convex surface refers to the first surface protruding outward relative to the second surface; a concave surface refers to the first surface recessed inward relative to the second surface. In one embodiment, the first surface of the near-infrared absorption layer serves as the light incident surface, causing the light to converge or diverge due to the first surface, thereby making the near-infrared absorption layer a microlens.

[0085] A second aspect of the present invention is a method for preparing a composite photosensitive structure, comprising:

[0086] Prepare a copper compound for providing copper ions, a phosphonic acid as shown in Formula 1, at least one phosphorus-containing compound as shown in Formulas 2 to 4, and form a coating solution containing a copper complex.

[0087]

[0088] Wherein, R, R1, R2, and R3 are each independently substituted or unsubstituted C1 to C2. 12 Alkyl or C6 to C 12 Aryl;

[0089] The coating solution is applied to a wafer containing a photosensitive element array and cured to form a near-infrared absorption layer; and

[0090] The wafer is cut to obtain a composite photosensitive structure.

[0091] Specific implementation methods are as follows Figures 1 to 4As illustrated, a copper compound, phosphonic acid, and a phosphorus-containing compound are first prepared to provide copper ions, and then mixed with a solvent to form a dispersion. This mixing can be achieved, for example, by first mixing the copper compound and the solvent to form a first mixture, and then mixing the phosphorus-containing compound and the solvent to form a second mixture. The first and second mixtures are then mixed with the phosphonic acid to form the dispersion. Here, due to the reactions and interactions of the components, a copper complex is formed in the dispersion.

[0092] To form the coating solution, the dispersion is further mixed with optical resins, namely those described in the first aspect of this document.

[0093] In one embodiment, the dispersion is first dried into a powder, then the powder is added to a second solvent to form a dispersion, which is then mixed with an optical resin. The second solvent may be selected from the solvents described in the first aspect herein.

[0094] In the case of adding an absorbent dye, the absorbent dye may also be optionally added to the dispersion / coating solution, for example, added to the dispersion before mixing with the optical resin, mixed with the optical resin together with the dispersion, or added to the coating solution after the dispersion is mixed with the optical resin.

[0095] like Figure 1 As shown, the coating solution 20 is applied to a wafer 10 containing an array of photosensitive elements (including multiple photosensitive areas 11). Optionally, before or after coating, the coating solution is degassed, for example by ultrasonic vibration, placing it in a negative pressure environment, or both. The coating process is not limited to specific embodiments; for example, it can be applied by spin coating, spray coating, blade coating, roller coating, dip coating, etc.

[0096] Then, the coating liquid is cured to form a near-infrared absorbing layer. For example... Figure 2 As illustrated, curing can be achieved by light curing, where a near-infrared absorption layer 21 is formed on the entire wafer 10 by irradiating the coating liquid with a light source L.

[0097] For example Figure 3 and Figure 4 As shown, a cutting tool C, such as a laser or diamond cutter, is used to cut the wafer 10 to obtain a composite photosensitive structure 1, which has a photosensitive element 12 and a near-infrared absorption layer 21 formed thereon.

[0098] Figures 5 to 7 To illustrate another specific embodiment of the method for preparing a composite photosensitive structure, compared to Figures 1 to 4 A step of adding a patterned near-infrared absorption layer was added. Figures 5 to 7 The process shown follows the Figure 1 Then and respectively corresponding Figures 2 to 4 The difference lies in, relative to Figure 2 , Figure 5Further, a photolithography process is introduced, specifically involving setting a photomask M, such as a grayscale photomask, so that the underlying coating liquid is selectively exposed to obtain a near-infrared absorption layer 21', 21' with a specific pattern or shape. The specific pattern or shape is as follows: Figure 6 and Figure 7 As illustrated, the first surface of the near-infrared absorbing layer can be made to protrude upwards or be recessed downwards.

[0099] In one embodiment, the coating liquid on the entire wafer forms an independent patterned near-infrared absorption layer above the corresponding photosensitive area 11, such as... Figure 6 and Figure 7 The near-infrared absorption layers 21' and 21' shown here are independent, specifically meaning that there is no contact between any two adjacent infrared absorption layers, which can be achieved through the photolithography process described above.

[0100] In one embodiment, the coating liquid is dried (e.g., at 120°C) before curing to remove the solvent.

[0101] The present invention will be described in further detail with reference to the following specific embodiments; however, these specific embodiments are by no means intended to limit the scope of the invention.

[0102] Preparation Example 1 – Near-infrared absorption layer

[0103] 150 parts by weight of copper acetate and 15,000 parts by weight of ethanol were mixed and stirred at room temperature for 1.5 hours to form a first mixture. Separately, 20 parts by weight of the phosphorus-containing compound of Formula 2 (plysurf A242G, purchased from Daiichi Kogyo Pharmaceutical Co., Ltd.), 20 parts by weight of the phosphorus-containing compound of Formula 3 (plysurf W542C, purchased from Daiichi Kogyo Pharmaceutical Co., Ltd.), and 50 parts by weight of the phosphorus-containing compound of Formula 4 (plysurf A285C, purchased from Daiichi Kogyo Pharmaceutical Co., Ltd.) were mixed with 1,500 parts by weight of ethanol to form a second mixture. The first and second mixtures were then mixed and stirred at room temperature for 1 hour. Next, 100 parts by weight of butylphosphonic acid were added, and the mixture was stirred at room temperature for 3 hours. Finally, the mixture was placed in an oven at 85°C for 12 hours to obtain a powder. The powder and xylene were mixed in a weight ratio of 1:3 to form a dispersion. The dispersion was then mixed with methyl methacrylate (MMA) in a weight ratio of 0.65:0.35 to form a coating liquid. The coating liquid was then applied to a substrate and baked at 70°C for 30 minutes to obtain a near-infrared absorption layer.

[0104] X-ray photoelectron (ESCA / XPS) analysis was performed on the aforementioned near-infrared absorbing layer, and its X-ray photoelectron energy spectrum is as follows: Figure 5As shown, characteristic peaks associated with copper complexes (Cu(PO4)2) can be observed at binding energies from 930 eV to 940 eV. x ) y (CuO, Cu2O, Cu(OH)2). Additionally, peaks appearing at binding energies above 940 eV are satellite peaks.

[0105] Example 1

[0106] The dispersion and coating solution were prepared according to the method of Preparation Example 1, but 0.5 g of azobisisobutyronitrile (AIBN) as a photopolymerization initiator and an appropriate amount of propylene glycol monomethyl ether (PGME) solvent were additionally added to the coating solution. Bubbles were then removed by ultrasonic vibration under negative pressure, and the solution was spin-coated onto a wafer with a pre-formed photosensitive element array. The solvent was removed by baking at 120°C, and the coating layer was then irradiated with ultraviolet light to form a near-infrared absorption layer on the surface of the photosensitive element array. Finally, the wafer was laser-cut to obtain a composite photosensitive structure.

[0107] Example 2

[0108] According to Example 1, a near-infrared absorption layer is formed on a wafer with a completed photosensitive element array. The difference lies in that a grayscale photomask is placed above the wafer after the spin coating step and before ultraviolet irradiation, allowing the coating layer to be selectively exposed. Thus, a patterned near-infrared absorption layer is formed on the surface of the photosensitive element array, resulting in a composite photosensitive structure.

[0109] The above-described embodiments and specific examples are not intended to limit the present invention. The listed technical features or solutions can be combined with each other. The present invention can also be implemented or applied through other different embodiments. The details described herein can also be given different changes or modifications according to different viewpoints and applications without departing from the present invention.

Claims

1. A composite photosensitive structure, characterized in that, include: Photosensitive element; as well as A near-infrared absorbing layer is formed on the photosensitive element, wherein the near-infrared absorbing layer comprises a copper complex, the copper complex being formed by a copper compound for providing copper ions, a phosphonic acid as shown in [Formula 1], and at least one phosphorus-containing compound as shown in [Formula 2] to [Formula 4]. Wherein, R, R1, R2, and R3 are each independently substituted or unsubstituted C1 to C2. 12 Alkyl or C6 to C 12 Aryl, The near-infrared absorption layer has an OD value greater than 4 for incident light wavelengths from 930nm to 950nm.

2. The composite photosensitive structure according to claim 1, characterized in that, The photosensitive element is a photocoupler or a complementary metal-oxide-semiconductor sensor.

3. The composite photosensitive structure according to claim 1, characterized in that, The substituted or unsubstituted C1 to C 12 The alkyl group is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, and tert-butyl; the substituted or unsubstituted C6 to C6 alkyl group is also included. 12 The aryl group is selected from the group consisting of phenyl, naphthyl, and chlorophenyl.

4. The composite photosensitive structure according to claim 1, characterized in that, The near-infrared absorption layer has a haze of less than 0.4%.

5. The composite photosensitive structure according to claim 1, characterized in that, The X-ray photoelectron spectrum of the near-infrared absorption layer has at least one main peak when the binding energy is between 930 eV and 940 eV.

6. The composite photosensitive structure according to claim 5, characterized in that, The count value per second of at least one main peak is above 4500.

7. The composite photosensitive structure according to claim 1, characterized in that, The thickness of the near-infrared absorption layer is 25 μm to 150 μm.

8. The composite photosensitive structure according to claim 1, characterized in that, The photosensitive element includes multiple photosensitive areas, and the near-infrared absorption layer is formed on each of the photosensitive areas, with the boundary of the near-infrared absorption layer flush with or extending beyond the boundary of the photosensitive area.

9. The composite photosensitive structure according to claim 8, characterized in that, The near-infrared absorption layer has a first surface and a second surface opposite to each other, the second surface being in contact with the surface of the photosensitive area, and the first surface being a plane, a convex surface, or a concave surface.

10. The composite photosensitive structure according to claim 9, characterized in that, The near-infrared absorption layer serves as a microlens.

11. A method for preparing a composite photosensitive structure, characterized in that, include: Prepare a copper compound for providing copper ions, a phosphonic acid as shown in [Formula 1], and at least one phosphorus-containing compound as shown in [Formula 2] to [Formula 4], and form a coating solution containing a copper complex. Among them, R, R1, R2, and R3 are each independently substituted or unsubstituted C1 to C3. 12 Alkyl or C6 to C 12 Aryl; The coating liquid is applied to a wafer containing a photosensitive element array and cured to form a near-infrared absorption layer; and The wafer is cut to obtain a composite photosensitive structure. The near-infrared absorption layer has an absorbance OD value greater than 4 for incident light wavelengths from 930nm to 950nm.

12. The method according to claim 11, characterized in that, The photosensitive element is a photocoupler or a complementary metal-oxide-semiconductor sensor.

13. The method according to claim 11, characterized in that, The substituted or unsubstituted C1 to C 12 The alkyl group is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, and tert-butyl; the substituted or unsubstituted C6 to C6 alkyl group is also included. 12 The aryl group is selected from the group consisting of phenyl, naphthyl, and chlorophenyl.

14. The method according to claim 11, characterized in that, The near-infrared absorption layer has a haze of less than 0.4%.

15. The method according to claim 11, characterized in that, The X-ray photoelectron spectrum of the near-infrared absorption layer has at least one main peak when the binding energy is between 930 eV and 940 eV.

16. The method according to claim 15, characterized in that, The count value per second of at least one main peak is above 4500.

17. The method according to claim 16, characterized in that, The thickness of the near-infrared absorption layer is 25 μm to 150 μm.

18. The method according to claim 11, characterized in that, The curing process is photocuring, and the coating liquid is dried before curing to remove the solvent.

19. The method according to claim 11, characterized in that, It also includes patterning the near-infrared absorption layer using a photolithography process.

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