CN117631114A

CN117631114A - Method for manufacturing optical filter unit and optical filter unit

Info

Publication number: CN117631114A
Application number: CN202410107513.6A
Authority: CN
Inventors: 萧玉焜; 李政哲; 刘佳府; 陈永昌; 黄丞铵
Original assignee: Yijin Optical Technology Nantong Co ltd
Current assignee: Yijin Optical Technology Nantong Co ltd
Priority date: 2024-01-26
Filing date: 2024-01-26
Publication date: 2024-03-01

Abstract

The invention relates to a manufacturing method of a light filtering unit and the light filtering unit. The manufacturing method of the optical filter unit comprises a cutting step and a separating step. The cutting step and the separating step are to cut the filter to be processed by using different cutting modes. In the cutting step, a plurality of grooves are formed on the filter to be processed, and the substrate of the filter to be processed is not cut off. In the separating step, the substrate is cut along the grooves, so that the filter to be processed is formed into a plurality of filter units. At least a portion of the side wall of the organic dye layer of the filter to be treated is covered by a protective structure prior to the separation step.

Description

Method for manufacturing optical filter unit and optical filter unit

Technical Field

The present invention relates to an optical element, and more particularly, to a method for manufacturing a filter unit and a filter unit.

Background

Conventional filters, such as those used in cameras to filter out non-visible light, have substantially completely exposed sidewalls of the organic dye layer during manufacturing, and therefore, the exposed organic dye layer is susceptible to damage or breakage during manufacturing, such as environmental testing of the filter unit (e.g., placing the filter unit in a high temperature, high pressure environment, etc.).

Disclosure of Invention

The invention aims to solve the technical problem of providing a manufacturing method of a light filtering unit, which overcomes the defects of the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

the method for manufacturing the optical filter unit is used for cutting an optical filter to be processed into a plurality of optical filter units, the optical filter to be processed at least comprises a substrate, an organic dye layer and an inorganic optical composite layer, the thickness of the organic dye layer and the thickness of the substrate are respectively defined as a first thickness D1, a second thickness D2 and a third thickness D3, the substrate and the inorganic optical composite layer are respectively arranged on two sides of the organic dye layer, and the method for manufacturing the optical filter unit comprises the following steps: and a cutting step: cutting the optical filter to be processed by utilizing a first cutting mode to form a plurality of grooves on one side of the optical filter to be processed, wherein the depth of each groove is defined as a preset depth Q; the preset depth Q, the first thickness D1, the second thickness D2 and the third thickness D3 conform to: d1+d2+ (d3×15%) gtoreq is greater than or equal to d1+ (d2×50%); a separation step: cutting the optical filter to be processed along the grooves by utilizing a second cutting mode so as to cut off the substrate, and cutting the optical filter to be processed into a plurality of optical filter units; the second cutting mode is different from the first cutting mode, wherein at least one part of the side wall of the organic dye layer is covered by a protective structure before the separation step is carried out; when viewed from the cross section direction, the upper side and the lower side of the light filtering unit are respectively provided with a first width W1 and a second width W2, and the first width W1 is smaller than the second width W2; the substrate is positioned at the lower side of the light filtering unit.

In an embodiment, each of the grooves included in the filter to be processed after the cutting step includes a first section and a second section, the first section is adjacent to the inorganic optical composite layer, and the second section is adjacent to the substrate; a width of the groove gradually expands from a position close to the substrate to a direction far away from the substrate in the second section.

In an embodiment, the first cutting mode is to use a cutter, the second cutting mode is to use laser to irradiate the positions of the substrate corresponding to the grooves so as to destroy the structure of the positions of the substrate corresponding to the grooves, and then stretch the filter to be processed.

In one embodiment, between the cutting step and the separating step, further comprising:

an inorganic protective layer forming step: forming an inorganic protective layer on one side of the filter to be treated, on which a plurality of grooves are formed, to cover the inner wall of each groove, wherein the inorganic protective layer is used as the protective structure; the thickness of the inorganic protective layer is 0.2% -20% of the width of each groove; wherein at least a portion of an organic dye layer side surface of the organic dye layer included in each of the filter units formed by the separating step is covered with the inorganic protective layer.

In one embodiment, after the cutting step, a portion of the substrate is exposed in the trench; the side surface of the inorganic optical composite layer ring of the inorganic optical composite layer contained in each filter unit is covered by the inorganic protective layer; a part of the substrate included in each of the filter units is covered with the inorganic protective layer included in the filter unit.

In an embodiment, the laser with different wavelengths is used in the cutting step and the separating step, and after the cutting step, at least a part of the organic dye layer in the trench is formed into an organic coking structure, and the organic coking structure is used as the protection structure; and after the filter to be treated is cut into a plurality of filter units, at least one part of the side surface of the organic dye layer ring of the organic dye layer contained in each filter unit is covered by the organic coking structure.

In an embodiment, a plurality of rugged notches are formed on an edge of the filter unit, a path cut by the second cutting mode at the edge is defined as a separation path, a straight line parallel to the separation path, which is extended from a point closest to an inner side of the filter unit in the edge, is defined as a notch inner edge line, a straight line parallel to the separation path, which is extended from a point closest to an outer side of the filter unit in the edge, is defined as a notch outer edge line, a distance between the notch inner edge line and the notch outer edge line is defined as a notch width, and the notch width is less than 50 micrometers.

In one embodiment, the method is characterized by: the second thickness (D2) is 20 micrometers or more.

Another object of the present invention is to provide a light filtering unit.

a filter unit, characterized by: comprising: a substrate; an organic dye layer arranged on one side of the substrate, wherein the thickness of the organic dye layer is more than 20 micrometers; a protective structure covering at least a portion of a sidewall of the organic dye layer; an inorganic optical composite layer disposed on a side of the organic dye layer opposite to the substrate; wherein, when viewed from the cross section direction, the upper side and the lower side of the light filtering unit are respectively provided with a first width (W1) and a second width (W2), and the first width (W1) is smaller than the second width (W2); the substrate is positioned at the lower side of the light filtering unit.

In an embodiment, the side wall of the filtering unit has a step portion, and the step portion is located on the side wall of the organic dye layer, or the step portion is located on the side wall of the substrate, or the step portion is located at the junction between the organic dye layer and the substrate.

In one embodiment, the difference between the first width (W1) and the second width (W2) is 5-150 microns.

In an embodiment, a filter to be processed is separated into a plurality of filter units by a separation step, the separation step cuts and separates the substrate, a plurality of rugged notches are formed at an edge of the filter units, a path cut by the separation step at the edge is defined as a separation path, a straight line parallel to the separation path, which extends at a point closest to an inner side of the filter units in the edge, is defined as a notch inner edge line, a straight line parallel to the separation path, which extends at a point closest to an outer side of the filter units in the edge, is defined as a notch outer edge line, a distance between the notch inner edge line and the notch outer edge line is defined as a notch width, and the notch width is less than 50 micrometers.

In an embodiment, the filtering unit further comprises: an inorganic protective layer which completely covers a top surface of the inorganic optical composite layer and an inorganic optical composite layer ring side surface and covers at least a portion of an organic dye layer ring side surface of the organic dye layer, the inorganic protective layer being used as the protective structure; wherein the thickness of the inorganic optical composite layer, the thickness of the organic dye layer and the thickness of the substrate are respectively defined as a first thickness (D1), a second thickness (D2) and a third thickness (D3); the total height of the inorganic protective layer covering the side surface of the ring of the light filtering unit is defined as a preset height (q); the first thickness (D1), the second thickness (D2), the third thickness (D3) and the preset height (q) correspond to: d1+d2+ (d3×15%) gtoreq.gtoreq.gtoreq.gtoreq.1+ (d2×50%) relational expression.

In an embodiment, the filter unit is divided into a first portion, a second portion and a third portion from a side with the inorganic optical composite layer to a side of the substrate in sequence by widths, wherein the width of the first portion is equal to the minimum width of the second portion, and the width of the third portion is equal to the maximum width of the second portion; the width of the second part of the optical filter unit gradually increases from one side close to the inorganic optical composite layer to one side of the substrate; the first portion comprises a portion of the inorganic optical composite layer and the organic dye layer; the second portion comprises a further portion of the organic dye layer; the third portion includes the remainder of the organic dye layer and the substrate; wherein a thickness of an unexposed portion of the organic dye layer ring side of the organic dye layer is not less than 50% of the second thickness (D2) of the organic dye layer; wherein the first thickness (D1), the second thickness (D2), the third thickness (D3) and the preset height (q) correspond to: D1+D2 > q.gtoreq.gtoreq.D1+ (D2.times.50%) relationship.

In an embodiment, the filter unit is divided into a first portion, a second portion and a third portion from a side with the inorganic optical composite layer to a side of the substrate in sequence by widths, wherein the width of the first portion is equal to the minimum width of the second portion, and the width of the third portion is equal to the maximum width of the second portion; the width of the second part of the optical filter unit gradually increases from one side close to the inorganic optical composite layer to one side of the substrate; the first portion comprises the inorganic optical composite layer and the organic dye layer; the second portion comprises a portion of the substrate; the third portion comprises another portion of the substrate; wherein the first thickness (D1), the second thickness (D2), the third thickness (D3) and the preset height (q) correspond to: d1+d2+ (d3×15%) gtoreq > d1+d2.

In an embodiment, the filter unit is divided into a first portion, a second portion and a third portion from a side with the inorganic optical composite layer to a side of the substrate in sequence by widths, wherein the width of the first portion is equal to the minimum width of the second portion, and the width of the third portion is equal to the maximum width of the second portion; the width of the second part of the optical filter unit gradually increases from one side close to the inorganic optical composite layer to one side of the substrate; the first portion comprises a portion of the inorganic optical composite layer and the organic dye layer; the second portion comprises another portion of the organic dye layer; the third portion comprises the substrate; wherein the first thickness (D1), the second thickness (D2), the third thickness (D3) and the preset height (q) correspond to: q=d1+d2.

In an embodiment, the inorganic optical composite layer includes a plurality of first refractive layers and a plurality of second refractive layers, and a refractive index of any one of the first refractive layers is higher than a refractive index of any one of the second refractive layers; the inorganic protection layer and one of the first refraction layers are made of the same material, or the inorganic protection layer and one of the second refraction layers are made of the same material.

In an embodiment, the filtering unit further comprises: an organic coking structure covering at least a portion of an organic dye layer ring side of the organic dye layer; the organic coking structure is a structure formed by the organic dye layer after laser irradiation, and is used as the protection structure; wherein the total height of the organic coking structure covering the organic dye layer is more than 50% of the thickness of the organic dye layer.

In one embodiment, the oxygen-carbon ratio of the organic coking structure is 2.46-6.92 times that of the organic dye layer which is not irradiated by laser.

In one embodiment, the organic coking structure has an oxygen to carbon ratio of from 1.18 to 1.66.

In one embodiment, the organic coking structure exhibits an L-shape when viewed in cross-section.

In one embodiment, the organic coking structure exhibits an I-shape when viewed in cross-section.

In summary, in the method for manufacturing a filter unit and the filter unit of the present invention, the protection structure is formed to completely or partially cover the sidewall of the organic dye layer, thereby protecting the organic dye layer. Therefore, the organic dye layer is not easily damaged in the subsequent process of the optical filter unit, and the production yield of the optical filter unit can be effectively improved.

For a further understanding of the features and technical aspects of the present invention, reference should be made to the following detailed description of the invention and the accompanying drawings, which are included to illustrate and not to limit the scope of the invention.

Drawings

FIG. 1 is a flow chart of a first embodiment of a method for manufacturing a filter unit;

fig. 2 is a top view of the filter to be processed after the cutting step of the first embodiment;

FIG. 3 is a schematic partial cross-sectional view of the filter to be processed after passing through the cutting step of the first embodiment;

fig. 4 is a schematic partial cross-sectional view of the filter to be treated after passing through the inorganic protective layer forming step of the first embodiment;

FIG. 5 is a schematic cross-sectional view of a first embodiment of a filter unit;

FIG. 6 is a schematic top view of a single filter unit after performing a dicing process;

fig. 7 is a schematic partial cross-sectional view of the filter to be treated after passing through the inorganic protective layer forming step of the second embodiment;

FIG. 8 is a schematic cross-sectional view of a second embodiment of a filter unit;

fig. 9 is a schematic partial cross-sectional view of a filter to be treated after passing through an inorganic protective layer forming step of the third embodiment;

FIG. 10 is a schematic cross-sectional view of a third embodiment of a filter unit;

Fig. 11 to 13 are schematic partial cross-sectional views of a filter to be processed after cutting steps of three different embodiments of a method for manufacturing a filter unit;

fig. 14 is a schematic partial cross-sectional view of a filter to be treated after passing through an inorganic protective layer forming step of the fourth embodiment;

FIG. 15 is a schematic cross-sectional view of a fourth embodiment of a filter unit;

fig. 16 is a schematic partial cross-sectional view of a filter to be treated after passing through an inorganic protective layer forming step of the fifth embodiment;

FIG. 17 is a schematic cross-sectional view of a fifth embodiment of a filter unit;

FIG. 18 is a flowchart of a sixth embodiment of a method for manufacturing a filter unit;

fig. 19 is a schematic cross-sectional view through a cutting step of the sixth embodiment;

FIG. 20 is a schematic cross-sectional view of a sixth embodiment of a filter unit;

fig. 21 is a schematic cross-sectional view through a cutting step of the seventh embodiment;

FIG. 22 is a schematic cross-sectional view of a seventh embodiment of a filter unit;

FIG. 23 is a schematic cross-sectional view through the eighth embodiment after a cutting step;

fig. 24 is a schematic cross-sectional view of an eighth embodiment of a filter unit.

Wherein reference numerals are as follows:

1: a filter to be treated; 11: a substrate; 12: an organic dye layer; 12A: an organic coking structure; 13: an inorganic optical composite layer; 131: a top surface; 14: a groove; 141: a first section; 142: a second section; 143: an inclined surface; 14W: a width; 15: an inorganic protective layer; 15D: thickness; d21: the thickness of the unexposed part; 16: an auxiliary inorganic optical composite layer; 17: a light shielding structure; 18: an auxiliary inorganic protective layer; 19: an auxiliary organic dye layer; 20: an insulating layer; 5A: a first filter unit; 5B: a second filter unit; 5C: a third filter unit; 5D: a fourth filtering unit; 5E: a fifth filtering unit; 5F: a sixth filtering unit; 5G: a seventh filtering unit; 5H: an eighth filter unit; 5AX: a step part; 521: an organic dye ring side; 532: an inorganic optical composite layer ring side; 5A1: a first portion; 5A2: second portion 5A3: a third section; q: presetting depth; q: presetting a height; t: the total height; d1: a first thickness; d2: a second thickness; d3: a third thickness; w1: a first width; w2: a second width; Δw: a width difference; 6E: edges; 6I: a notch inner edge line; 6O: a notch outer edge line; CW: the width of the notch; s11: a cutting step; s12: an inorganic protective layer forming step; s13: and (3) a separation step.

Detailed Description

In the following description, reference is made to or as illustrated in the accompanying drawings, which are for the purpose of highlighting the relevant details of the description that follows, and in no way limit the description to the specific drawings, but should be read in light of the specific drawings.

It should be noted that the thicknesses of the layers of the filter to be processed and the proportional relationship therebetween, and the thicknesses of the layers of the filter unit and the proportional relationship therebetween are shown in the drawings for convenience of description, and are not intended to limit the proportional relationship of the structures of the layers of the filter to be processed. In addition, cross-sectional lines are omitted from the cross-sectional views for clarity of presentation.

Fig. 1 to 5 are schematic flow diagrams of a first embodiment of a method for manufacturing a filter unit, a top view of a filter to be processed after a cutting step, a schematic partial cross-sectional view of the filter to be processed after the cutting step, a schematic partial cross-sectional view of the filter to be processed after an inorganic protective layer forming step, and a schematic partial cross-sectional view of a single filter unit formed after a separating step, respectively; FIG. 5 is a schematic cross-sectional view of a first embodiment of the filter unit.

As shown in fig. 1 to 3, the method for manufacturing a filter unit according to the present embodiment is used for cutting a filter 1 to be processed (as shown in fig. 2) into a plurality of first filter units 5A (as shown in fig. 5). The filter 1 to be processed at least comprises a substrate 11, an organic dye layer 12 and an inorganic optical composite layer 13, wherein the substrate 11 and the inorganic optical composite layer 13 are respectively arranged on the upper side and the lower side of the organic dye layer 12.

The to-be-processed filter 1 refers to a filter which is not cut, and after the to-be-processed filter 1 is cut into a plurality of first filter units 5A, the size of each first filter unit 5A may be close to the size of the final product to be applied. For example, assuming that the first filter units 5A are finally mounted in the camera after the subsequent processing, the size of each first filter unit 5A formed by cutting the filter 1 to be processed is substantially the same as the size when finally mounted in the camera.

In practical applications, the substrate 11, the organic dye layer 12 and the inorganic optical composite layer 13 included in the filter 1 to be processed may be specifically included in each of them, and may be selected according to the final product of the first filter unit 5A, which is not limited herein. In practical applications, the substrate 11 may be an organic substrate, an inorganic substrate, or a multi-layer composite substrate (e.g., including a plurality of organic layers and a plurality of inorganic layers). The substrate 11 serves as a main support structure for the first filter unit 5A. The organic dye layer 12 is used to absorb the light beam in a specific wavelength range so that it cannot pass through the first filter unit 5A. The inorganic optical composite layer 13 is used to determine which specific wavelength range of light beams can pass through the first filter unit 5A.

For example, assuming that the first filter unit 5A is finally applied to a camera lens, glasses, front windshield of an automobile, etc., for filtering the invisible light, the substrate 11 may be an inorganic substrate such as blue glass, white glass, etc.; the organic dye layer 12 may be a dye (ultraviolet light absorber, infrared light absorber), an adhesive agent, a leveling agent, or the like containing an optical band that absorbs specific non-visible light; the inorganic optical composite layer 13 may be a structure including a plurality of first refractive layers H and a plurality of second refractive layers L stacked alternately, wherein the refractive index of any one of the first refractive layers is higher than that of any one of the second refractive layers, i.e., hlhlhl … HL is stacked as such. Regarding the design of the total number of the first refractive layers, the thickness of each first refractive layer, the total number of the second refractive layers, the thickness of each second refractive layer, and the like included in the inorganic optical composite layer 13, the refractive index, the transparent region, and the thickness of the organic dye layer 12 should be considered together, and the entire organic dye layer 12 is considered as a third refractive layer n in consideration of the spectral design. Therefore, the design of the final film layer is nHLHL … HL, and is designed according to the situation of the practical first filter unit 5A and the wavelength range of the light beam to be filtered. The specific materials of the first refractive layer and the second refractive layer are not particularly limited as long as they meet the desired optical characteristics (for example, refractive index, extinction coefficient). For example, the first refractive layer and the second refractive layer may each include an oxide, a nitride, an oxynitride, a carbide, other suitable optical coating materials, or a combination thereof, and specifically may include, but not limited to, silicon hydride, silicon oxynitride, silicon dioxide, aluminum oxide, titanium dioxide, niobium pentoxide, tantalum pentoxide, silicon nitride, silicon oxynitride, silicon carbide, magnesium fluoride, zirconium dioxide, and the like.

The manufacturing method of the optical filter unit comprises the following steps: a cutting step S11 and a separating step S13. At least a portion of the sidewalls of the organic dye layer is covered by a protective structure prior to the separating step S13. In the present embodiment, an inorganic protective layer forming step S12 is further included between the dicing step S11 and the separating step S13, and an inorganic protective layer 15 (described in detail later) formed in this step may be used as the above-described protective structure.

As shown in fig. 1, 2 and 3, the cutting step S11 is: the filter 1 to be processed is cut by a first cutting method, so as to form a plurality of grooves 14 on one side of the filter 1 to be processed. As shown in fig. 2, after the cutting step S11, the plurality of grooves 14 may communicate with each other, and the plurality of grooves 14 communicating with each other may substantially take the form of mesh grooves in the top view of the filter 1 to be processed. Of course, the relative relationship of the plurality of grooves 14 is not limited to fig. 2, and in other embodiments, only a portion of the grooves 14 may be in communication with each other, and a portion of the grooves 14 may not be in communication with each other.

In the dicing step S11, the thickness of the inorganic optical composite layer 13, the thickness of the organic dye layer 12 and the thickness of the substrate 11 are respectively defined as a first thickness D1, a second thickness D2 and a third thickness D3, and the depth of each trench 14 is defined as a predetermined depth Q. In the first embodiment, the preset depth Q, the first thickness D1, the second thickness D2, and the third thickness D3 conform to: d1+d2+ (d3×15%) gtoreq > d1+d2. Wherein Q > d1+d2 is represented by: after the dicing step S11, the inorganic optical composite layer 13 and the organic dye layer 12 are completely cut off at the positions of the grooves 14; d1+d2+ (d3×15%) Σq represents: after the dicing step S11, the substrate 11 is not cut at the position of the groove 14, but is cut up to 15% of the third thickness D3 of the substrate 11.

As shown in fig. 3, in the present embodiment, the sum of the preset depth Q, which is approximately equal to the sum of the first thickness D1, the second thickness D2 and the third thickness D3 of 15%, that is, d1+d2+ (d3×15%) Σq is taken as an example, but the preset depth Q is not limited to this, and all the preset depth Q is within the practical range as long as it meets the above relation. When the substrate 11 includes an inorganic material (e.g., glass), if the preset depth Q is too large, the degree of abrasion of the tool is easily increased, the lifetime of the tool is reduced, and the edges of the filter unit are easily insufficiently aligned, reducing the yield of the product. In other embodiments, the predetermined depth Q is not greater than d1+d2+ (d3×10%). In other embodiments, the preset depth Q is not greater than d1+d2+ (d3×5%).

In the embodiment where the first filter unit 5A is finally applied to the camera lens, the first thickness D1, the second thickness D2 and the third thickness D3 may be 0.2 to 5 microns, 0.1 to 200 microns and 80 to 240 microns, respectively. The second thickness D2 may be a different thickness range depending on the specific dye composition and method of formation included in the organic dye layer 12, for example, in some embodiments, the organic dye layer 12 is formed using spin coating (spin on), and the second thickness D2 may be 0.1 to 2 microns, preferably 0.2 to 1 micron; in other embodiments, where the organic dye layer 12 is formed using a screen printing process, the second thickness D2 may be 2 to 10 microns, preferably 3 to 8 microns; in still other embodiments, the organic dye layer 12 is formed by dispersing a light absorbing dye in a binder polymer and coating the binder polymer on the substrate 11, and the second thickness D2 may be 10 to 200 micrometers, preferably 20 to 180 micrometers, more preferably 40 to 160 micrometers, and even more preferably 60 to 140 micrometers. The method for manufacturing the filter unit disclosed in the present specification is not particularly limited, and may be applied to a case where the organic dye layer has an arbitrary thickness.

As shown in fig. 1, 3 and 4, the inorganic protective layer forming step S12 is: on the side of the filter 1 to be treated (i.e., the side where the grooves 14 are formed), an inorganic protective layer 15 is formed so as to cover the inner walls of the respective grooves 14 and to cover the top surface 131 of the inorganic optical composite layer 13 located between the two grooves 14. In practical applications, in the inorganic protective layer forming step S12, the inorganic protective layer 15 may be formed by physical vapor deposition, sputtering, or the like.

The inorganic protective layer 15 is mainly used to shield at least a portion of the organic dye layer 12 exposed in the trench 14. In practical applications, the thickness 15D of the inorganic protective layer 15 is approximately 0.2% to 20% of the width 14W of each trench 14, and the inorganic protective layer 15 does not substantially fill the trench 14. In particular applications, the inorganic protective layer 15 may also fill the trench 14. In some practical applications, the thickness 15D of the inorganic protective layer 15 may be 10-1000 nm, and the width of each trench 14 may be 6-100 microns, preferably 10-60 microns, and more preferably 20-40 microns.

As shown in fig. 3, in a specific application of the present embodiment, each trench 14 included in the filter 1 to be processed after the cutting step S11 includes a first section 141 and a second section 142. The first section 141 is adjacent to the organic dye layer 12 and the inorganic optical composite layer 13, and the second section 142 is adjacent to the substrate 11. The width 14W of the groove 14 gradually increases from a position close to the substrate 11 to a position away from the substrate 11 in the second section 142. So designed, the inorganic protective layer 15 can be formed in the trench 14 more easily and entirely covering the inner surface of the trench 14 at the inorganic protective layer forming step S12. In the case where the first cutting method is cutting with a cutter, the wide portion of each groove 14 formed by the cutting step S11 may be made to have the above-described design by selecting the shape of the cutter.

As shown in fig. 1, 4 and 5, the separation step S13 is: the filter 1 to be processed is cut along the plurality of grooves 14 by the second cutting method to cut the substrate 11 (in the embodiment shown in fig. 9 and 10, the inorganic protective layer 15, part of the organic dye layer 12 and the substrate 11 are cut), and the filter 1 to be processed is cut into a plurality of first filter units 5A. The second cutting mode is different from the first cutting mode. In one specific application of the present embodiment, the first cutting method may be cutting the optical filter 1 to be processed by using a cutter (such as a diamond cutter, but not limited to this), and the second cutting method may be cutting by using a visible light laser, that is, the second cutting method may be using a stealth laser wafer dicing (Laser Stealth Dicing) technology in combination with a dicing process to separate the optical filter 1 to be processed into a plurality of first filter units 5A. More specifically, the separation step may be: firstly, irradiating the positions of the substrate 11 corresponding to the grooves 14 by utilizing laser so as to destroy the structure of the positions of the substrate 11 corresponding to the grooves 14; the filter 1 to be processed is stretched again to separate the filter 1 to be processed into a plurality of first filter units 5A.

Fig. 6 is a schematic top view of a single filter unit formed by performing a diffusion process in a separation step. The expanding process stretches the filter 1 to be processed by applying mechanical stress to separate the portions of the filter 1 to be processed that have not been separated by laser irradiation, so that the portions (e.g., the substrate 11, or the substrate 11 and the organic dye layer 12) to be separated by laser irradiation will be torn during the expanding process. After the dicing process, the edge 6E of the single first filter unit 5A will form a plurality of rugged gaps (chipping), and the path cut by the second dicing method at the edge 6E of the filter unit is defined as a separation path (not shown in the figure). If a straight line parallel to the separation path extending at a point closest to the inner side of the first filter unit 5A in one of the edges 6E of the first filter unit 5A is defined as a notch inner edge line 6I, a straight line parallel to the separation path extending at a point closest to the outer side of the first filter unit 5A in the one of the edges 6E is defined as a notch outer edge line 6O, and a distance between the notch inner edge line 6I and the notch outer edge line 6O is defined as a notch width CW, the smaller the notch width CW, the better the collimation representing the edge of the first filter unit 5A.

As described above, the dicing process easily leaves a tear trace on the edge of the organic dye layer 12 or the substrate 11, which results in poor edge alignment of the first filter unit 5A, thereby reducing the yield of the product. This technical problem becomes more serious in the case of thicker layers of organic dye (e.g., 20 microns or more). For example, in embodiments where the organic dye layer comprises a binder, because the organic dye layer 12 is thicker (e.g., 20 microns or more), if the organic dye layer 12 is not cut prior to the dicing process, a problem of too large a notch width CW after the dicing process, i.e., poor collimation, may occur, which may result in material edge chipping due to mechanical impact during subsequent processing. In some embodiments, the notch width CW is less than 50 microns, preferably the notch width CW is less than 40 microns, more preferably the notch width CW is less than 30 microns. If the notch width CW is less than 50 microns, the effects of minimizing the cross-sectional area and avoiding material edge chipping are well achieved. Referring to fig. 3, 4 and 6, in the first embodiment, the organic dye layer 12 is completely cut before the dicing process is performed, so that the collimation degree of the first filter unit 5A is excellent, and specifically, the notch width CW may be less than 15 microns, preferably less than 10 microns, and more preferably less than 5 microns.

In practice, regarding the calculation mode of the notch width CW, a high-magnification microscope is used to capture the top view image of the cut single first filter unit 5A, and then a measurement software is used to define the notch inner edge line 6I and the notch outer edge line 6O, so as to calculate the notch width CW.

It should be noted that, through repeated experiments by the applicant, it was found that when the thickness of the organic dye layer 12 of the filter 1 to be processed is more than 10 micrometers (μm), if the visible laser (especially the green laser with the wavelength range of 510-550 nm) is used as the first cutting mode, the laser energy is insufficient to completely separate the organic dye layers 12 at both sides of the cut. As such, the notch width CW cannot be less than 50 microns, and the effects of minimizing the cross-sectional area and avoiding material edge chipping cannot be achieved. Therefore, in practical applications where the thickness of the organic dye layer 12 of the filter 1 to be processed is 20 μm or more, in the cutting step S11, the notch width CW is advantageously smaller than 50 μm by using the cutter as the first cutting method.

As shown in fig. 5, each of the first filter units 5A formed by the separation step sequentially includes a substrate 11, an organic dye layer 12, an inorganic optical composite layer 13, and an inorganic protective layer 15. The organic dye layer ring side 521 of the organic dye layer 12, the top surface 131 of the inorganic optical composite layer 13, and the inorganic optical composite layer ring side 532 are all completely covered with the inorganic protective layer 15, and a part of the substrate 11 is also covered with the inorganic protective layer 15. In practical applications, the single first filter unit 5A may be a substantially rectangular sheet, but not limited thereto, and the specific shape of the first filter unit 5A may be changed according to the requirements. Wherein the inorganic protective layer 15 of the first filter unit 5A is used as a protective structure to protect the organic dye layer 12.

In the embodiment where the inorganic optical composite layer 13 includes a plurality of first refractive layers and a plurality of second refractive layers, the main material of the inorganic protective layer 15 may be the same or substantially the same as the main material of one of the first refractive layers or the main material of one of the second refractive layers. The specific materials of the first refractive layer and the second refractive layer can be referred to the above description, and will not be repeated. In some embodiments, the material and the forming method of the inorganic protection layer 15 are the same as those of the first refractive layer or the second refractive layer, so that the inorganic protection layer 15 can be regarded as a part of the inorganic optical composite layer 13 to perform optical design, which can help the first optical filter unit 5A to exert the expected optical characteristics, and the inorganic protection layer 15 can be formed without using additional equipment or process, which has no obvious influence on the complexity and cost of the process.

The method for manufacturing the filter unit of the first embodiment can completely cover the organic dye layer ring side 521 of the organic dye layer 12 included in each of the finally formed first filter units 5A with the inorganic protective layer 15 by designing the cutting step S11, the inorganic protective layer forming step S12, and the separating step S13. This effectively reduces the risk of damaging or destroying the organic dye layer 12 during subsequent processing (e.g., high temperature, high pressure environmental testing). In the prior art, the side wall of the organic dye layer of the optical filter unit has no protection structure, so that the organic dye layer of the optical filter unit is easily damaged or destroyed in the subsequent processing process (especially high-temperature and high-pressure environment test), thereby reducing the yield of the optical filter unit.

For the known filter unit, the above technical problems of filter failure caused by exposure of the organic dye layer and poor edge alignment caused by the process of expanding the film are more serious in the case of thicker organic dye layer. Therefore, the method of manufacturing the filter unit of the present specification is applied to an embodiment in which the organic dye layer is thicker (for example, 20 μm or more), and the resulting advantageous technical effects will be more remarkable. Of course, in practice, as long as D1, D2, D3, Q correspond to: on the premise of the relational expression that D1+D2+ (D3×15%) is greater than or equal to Q is greater than or equal to D1+ (D2×50%), the relevant technical personnel can determine the specific numerical values of D1, D2, D3 and Q according to different situations of the wavelength range actually required to be filtered by the first optical filtering unit 5A, the main material of the inorganic optical composite layer 13, the main material of the organic dye layer 12, the main material of the substrate 11, the finally applied scene of the first optical filtering unit 5A and the like.

Referring to fig. 5, the first filter unit 5A of the present embodiment may be manufactured by the manufacturing method of the filter unit, but is not limited thereto. For the substrate 11, the organic dye layer 12, the inorganic optical composite layer 13 and the inorganic protective layer 15 of the first filter unit 5A, please refer to the above description, and the detailed description is omitted. The thickness of the inorganic optical composite layer 13, the thickness of the organic dye layer 12, and the thickness of the substrate 11 are defined as a first thickness D1, a second thickness D2, and a third thickness D3, respectively; the total height of the inorganic protective layer 15 covering the ring side of the first filter unit 5A is defined as a preset height q. In the first embodiment, the first thickness D1, the second thickness D2, the third thickness D3 and the preset height q conform to: d1+d2+ (d3×15%) gtoreq > d1+d2, wherein the preset height Q is the same as the preset depth Q, and the relationship is the same as the relationship, so that no further description is given.

The first filter unit 5A shown in fig. 5 can be divided into a first portion 5A1, a second portion 5A2 and a third portion 5A3 according to the width. The widths of the first portions 5A1 of the first filter units 5A are substantially the same, the widths of the second portions 5A2 of the first filter units 5A gradually increase from the first portions 5A1 to the third portions 5A3, and the widths of the third portions 5A3 of the first filter units 5A are substantially the same. The first portion 5A1 includes an inorganic optical composite layer 13 and an organic dye layer 12, and the second portion 5A2 includes a part of the substrate 11. The third portion 5A3 comprises another portion of the substrate 11. It should be noted that, in practice, if the first filter unit 5A is manufactured by the manufacturing method of the filter unit of the present invention, since the filter 1 to be processed is cut twice (the cutting step and the separating step) and then finally forms the plurality of first filter units 5A, the first filter units 5A can be used to distinguish the first portion 5A1, the second portion 5A2 and the third portion 5A3 according to the width. That is, if a filter unit can be distinguished according to the width to match the relative relationship of the first portion 5A1, the second portion 5A2 and the third portion 5A3, it can be reasonably estimated that the filter unit is manufactured by the manufacturing method of the present embodiment.

As shown in fig. 5, since the two-stage dicing step (dicing step S11 and separating step S13) is performed, the upper and lower sides of the first filter unit 5A have the first width W1 and the second width W2, respectively, when viewed in the cross-section direction, and W1 is smaller than W2, and the substrate 11 of the first filter unit 5A is positioned at the lower side. In addition, the two side walls of the first filter unit 5A each have a step portion 5AX, and the step portion 5AX is located on the side wall of the substrate 11. In the present embodiment, there is a width difference Δw on the left and right sides of the first filter unit 5A, and the difference between the first width W1 and the second width W2 is determined by the cutting width of the first cutting mode, and the difference is about twice the width difference Δw. In the embodiment where the cutting step is performed by using a cutter, the difference (2 times Δw) between the first width W1 and the second width W2 may be 30 to 150 micrometers, preferably 50 to 100 micrometers, and more preferably 80 to 120 micrometers.

Referring to fig. 1, fig. 7 and fig. 8 together, fig. 7 and fig. 8 are a schematic partial cross-sectional view of a filter to be processed after passing through the inorganic passivation layer forming step of the second embodiment, and a schematic partial cross-sectional view of a second embodiment of the filter unit, respectively. As shown in fig. 7, the difference between the present embodiment and the first embodiment is that the predetermined depth of the trench is different. Specifically, the preset depth Q, the first thickness D1 and the second thickness D2 of each trench 14 in the present embodiment conform to: q=d1+d2. That is, in the dicing step S11, the inorganic optical composite layer 13 and the organic dye layer 12 are substantially completely cut at the positions where the grooves 14 are to be formed, and the substrate 11 is hardly diced at all.

As shown in fig. 8, in the second filter unit 5B of the present embodiment, the side 521 of the organic dye layer 12 is also completely covered by the inorganic protective layer 15, so that the risk of damage to the organic dye layer 12 can be avoided or greatly reduced during the subsequent processing. In the second embodiment, if the dicing step S11 is performed by using a cutter, the cutter will hardly cut the substrate 11 because the predetermined depth q=d1+d2. Therefore, the abrasion degree of the cutter can be effectively reduced, and the service life of the cutter is further prolonged.

Referring to fig. 8, the second filter unit 5B of the present embodiment can be divided into a first portion 5A1, a second portion 5A2 and a third portion 5A3 according to the width sequence. The widths of the first portions 5A1 of the second filter units 5B are substantially the same, the widths of the second portions 5A2 of the second filter units 5B gradually increase from the first portions 5A1 to the third portions 5A3, and the widths of the third portions 5A3 of the second filter units 5B are substantially the same. The first portion 5A1 includes a part of the inorganic optical composite layer 13 and the organic dye layer 12, and the second portion 5A2 includes another part of the organic dye layer 12. The third portion 5A3 includes a substrate 11. That is, if the filter unit can distinguish the relative relationship between the first portion 5A1, the second portion 5A2 and the third portion 5A3 according to the width, it can be reasonably estimated that the filter unit is manufactured by the manufacturing method of the present embodiment. The thickness of the inorganic optical composite layer 13, the thickness of the organic dye layer 12 and the thickness of the substrate 11 of the second filter unit 5B of the present embodiment are respectively defined as a first thickness D1, a second thickness D2 and a third thickness D3, and the total height of the inorganic protective layer 15 covering the ring side surface of the second filter unit 5B is defined as a predetermined height q, in the present embodiment, q=d1+d2. As shown in fig. 8, since the two-stage cutting step is adopted, the upper and lower sides of the second filter unit 5B have a first width W1 and a second width W2, respectively, when viewed in the cross-section direction, and W1 is smaller than W2; in addition, the two side walls of the second filter unit 5B have a step portion 5AX, and the step portion 5AX is located at the boundary between the substrate 111 and the organic dye layer 12. In this embodiment, the second filter unit 5B has a width difference Δw on the left and right sides, and the application range or the preferred range of the width difference Δw can be referred to the above description, and the description is omitted.

Referring to fig. 1, fig. 9 and fig. 10 together, fig. 9 and fig. 10 are a schematic partial cross-sectional view of a filter to be processed after passing through the inorganic protective layer forming step of the third embodiment and a schematic partial cross-sectional view of a third embodiment of a filter unit, respectively. As shown in fig. 9, the present embodiment is different from the first embodiment in that the preset depth of the groove is different. Specifically, the preset depth Q, the first thickness D1, and the second thickness D2 of each trench 14 correspond to: D1+D2> Q is equal to or greater than D1+ (D2 is 50%). In other words, in the dicing step S11, at the position where the trench 14 is to be formed, the substrate 11 is not diced at all, the inorganic optical composite layer 13 is completely cut, the organic dye layer 12 is partially diced, and at least 50% of the second thickness D2 of the organic dye layer 12 is diced.

As shown in fig. 10, in the third filter unit 5C of the present embodiment, at least 50% of the organic dye layer ring side 521 of the organic dye layer 12 is covered with the inorganic protective layer 15. That is, the unexposed portion thickness D21 of the organic dye layer ring side 521 of the organic dye layer 12 is not less than 50% of the second thickness D2 of the organic dye layer 12, and conforms to: d21 And (3) a relational expression of equal to or more than 50% of D2. So designed, the risk of damage to the organic dye layer 52 during subsequent processing can still be effectively reduced. In practical applications, if the thickness D21 of the unexposed portion of the ring side 521 of the organic dye layer 12 corresponds to that of the inorganic protective layer 15: d21 The relation ≡d2 by 50% significantly reduces the risk of damage to the organic dye layer 12. In order to reduce the risk of damaging the organic dye layer 12 even further, in some applications of the third embodiment, the unexposed portion thickness D21 of the organic dye layer ring side 521 may correspond to: d21 Relational expression of more than or equal to 65% of D2; in other applications, the unexposed portion thickness D21 of the organic dye layer collar side 521 may correspond to: d21 And (3) a relational expression of equal to or more than 80% of D2.

Referring to fig. 10, the third filter unit 5C of the present embodiment can be divided into a first portion 5A1, a second portion 5A2 and a third portion 5A3 according to the width sequence. The widths of the first portions 5A1 of the third filter units 5C are substantially the same, the widths of the second portions 5A2 of the third filter units 5C gradually increase from the first portions 5A1 to the third portions 5A3, and the widths of the third portions 5A3 of the third filter units 5C are substantially the same. The first portion 5A1 comprises a part of the inorganic optical composite layer 53 and the organic dye layer 52, the second portion 5A2 comprises a further part of the organic dye layer 52, and the third portion 5A3 comprises the rest of the substrate 11 and the organic dye layer 12. That is, if the filter unit can distinguish the relative relationship between the first portion 5A1, the second portion 5A2 and the third portion 5A3 according to the width, it can be reasonably estimated that the filter unit is manufactured by the manufacturing method of the present embodiment.

The thickness of the inorganic optical composite layer 13, the thickness of the organic dye layer 12 and the thickness of the substrate 11 of the third filter unit 5C of the present embodiment are defined as a first thickness D1, a second thickness D2 and a third thickness D3, respectively, and the total height of the inorganic protective layer 15 covering the ring side surface of the third filter unit 5C is defined as a preset height q, and d1+d2> q. As shown in fig. 10, since the two-stage cutting step is adopted, the upper and lower sides of the third filter unit 5C have a first width W1 and a second width W2, respectively, when viewed in the cross-section direction, and W1 is smaller than W2; in addition, the side walls of the third filter unit 5C have a step portion 5AX, respectively, and the step portion 5AX is located on the side wall of the organic dye layer 12. In this embodiment, the third filter unit 5C has a width difference Δw on the left and right sides, and the application range or the preferred range of the width difference Δw can be referred to the above description, which is not repeated herein.

In summary, in the method for manufacturing a filter unit according to the embodiment of the present invention, the design of the cutting step S11, the inorganic protective layer forming step S12, the separating step S13, and the like is matched to match the preset depth Q, the first thickness D1, the second thickness D2, and the third thickness D3: d1+d2+ (d3×15%) gtoreq is greater than or equal to d1+ (d2×50%) so that the organic dye layer ring side 521 of the organic dye layer of each filter unit can be completely or partially covered by a protective structure (for example, inorganic protective layer 15), thereby effectively reducing the risk of damaging or damaging the organic dye layer in the subsequent processing process and improving the yield of the filter unit.

Fig. 11 to 13 are schematic partial cross-sectional views of a filter to be processed after cutting steps of three different embodiments of a method for manufacturing a filter unit. In the cutting step S11, a cutter may be used to cut, and the shape of the trench 14 formed in the cutting step S11 will be different in the cross-sectional view of the filter 1 to be processed according to the shape of the cutter.

For example, as shown in fig. 11, the difference between the present embodiment and the foregoing embodiment is that: after the dicing step, each trench 14 includes a first section 141 and a second section 142, the first section 141 being adjacent to the inorganic optical composite layer 13, the second section 142 being adjacent to the substrate 11. In the second section 142, the width of the trench 14 gradually increases from a position close to the substrate 11 to a direction away from the substrate 11. The second section 142 of each groove 14 includes an inclined surface 143, and the inclined surface 143 has an inclination angle θ of 30 to 88 degrees. In the present embodiment, the cutting step may be cutting with a cutter corresponding to the shape of the groove shown in fig. 11, thereby forming the inclined surface 143.

In the embodiment shown in fig. 12, in the cross-sectional view of the filter 1 to be processed, the shape of each trench 14 may be substantially inverted triangle. In the embodiment shown in fig. 13, which shows a cross-section of the filter 1 to be processed, the shape of each trench 14 may be a parabolic line with a substantially upward opening. The shape of the trench 14 shown in fig. 12 or 13 is merely illustrative, and in practical applications, the cross-sectional profile of the trench 14 is within the acceptable range of the present specification as long as it has a uniform shape from top to bottom or gradually narrows from top to bottom.

It should be noted that, the preset depth of each trench 14 shown in fig. 11 to 13 may be changed according to the foregoing embodiments, and the shape of each trench 14 shown in fig. 11 to 13 and the preset depth Q corresponding to the shape of each trench are not particularly limited.

Fig. 14 and 15 are schematic partial cross-sectional views of a filter to be processed after passing through the inorganic passivation layer forming step of the fourth embodiment and a schematic partial cross-sectional view of a fourth embodiment of a filter unit, respectively.

As shown in fig. 14 and 15, the difference between the present embodiment and the first embodiment is that: before the separation step S11, a light shielding structure forming step may be further included: on the opposite side of the substrate 11 from the side where the organic dye layer 12 is formed, an auxiliary inorganic optical composite layer 16, a light shielding structure 17, and an auxiliary inorganic protective layer 18 are sequentially formed, and the light shielding structure 17 is covered with the auxiliary inorganic protective layer 18. After the separation step S11, each of the fourth filter units 5D sequentially includes an auxiliary inorganic optical composite layer 16, a light shielding structure 17 and an auxiliary inorganic protection layer 18 on a side of the substrate 11 opposite to the side on which the organic dye layer 12 is formed, and the light shielding structure 17 is completely covered by the auxiliary inorganic optical composite layer 18. The sequence of the cutting step S11, the inorganic passivation layer forming step S12, and the light shielding structure forming step may be designed according to the actual requirements, and is not limited herein. For example, in one practical application, the light shielding structure forming step, the cutting step S11, and the inorganic protection layer forming step S12 may be sequentially performed.

The auxiliary inorganic optical composite layer 16, the inorganic optical composite layer 13, the organic dye layer 12 and the substrate 11 are used together to determine which wavelength range of light beams are allowed to pass through the fourth filter unit 5D. Therefore, the structures, the number of layers, etc. specifically included in the auxiliary inorganic optical composite layer 16, the inorganic optical composite layer 13, the organic dye layer 12, and the substrate 11 can be designed according to the optical conditions required by the product of the final desired application of the fourth filter unit 5D. The auxiliary inorganic protection layer 18 is used to protect the light shielding structure 17 from being damaged during the subsequent manufacturing process (e.g., cleaning process, etc.). In an embodiment, the auxiliary inorganic optical composite layer 16 may include a plurality of first refractive layers and a plurality of second refractive layers, wherein the refractive index of each first refractive layer is higher than that of each second refractive layer, and the auxiliary inorganic protective layer 18 may be substantially the same material as one of the first refractive layers or one of the second refractive layers included in the auxiliary inorganic optical composite layer 16, but not limited thereto. The specific materials of the first refraction layer and the second refraction layer can be referred to the above description, and will not be repeated.

In an actual application, the auxiliary inorganic optical composite layer 16 may include multiple first refractive layers and multiple second refractive layers similar to the inorganic optical composite layer 13, but the number, thickness, refractive index, stacking manner, etc. of the first refractive layers and the second refractive layers included in the auxiliary inorganic optical composite layer 16 are not limited to the same as those of the inorganic optical composite layer 13. In a particular application, the auxiliary inorganic optical composite layer 16 and the inorganic optical composite layer 13 may also have substantially the same composition (including the number of layers of the first and second refractive layers, thickness, refractive index, stacking, etc.).

In practical applications, when the fourth filter unit 5D is installed in the application product, after the light beam passes through the fourth filter unit 5D, part of the light beam will be reflected to the side of the fourth filter unit 5D where the light shielding structure 17 is formed, and the light shielding structure 17 is used to absorb the reflected light beams. For example, when the fourth filter unit 5D is applied to a camera to filter non-visible light, a portion of the visible light passing through the fourth filter unit 5D may be reflected by the photosensitive member to the side of the fourth filter unit 5D where the light shielding structure 17 is formed. In this application scenario, if the light shielding structure 17 is not provided in the fourth optical filtering unit 5D, the light beam reflected by the photosensitive assembly may enter the photosensitive area of the photosensitive assembly, and finally, a similar ghost condition may occur in the photo; that is, by providing the light shielding structure 17, the above-described ghost can be effectively reduced.

As shown in fig. 15, the thickness of the inorganic optical composite layer 13, the thickness of the organic dye layer 12, and the thickness of the substrate 11 are defined as a first thickness D1, a second thickness D2, and a third thickness D3, respectively, and the total height of the inorganic protective layer 15 covering the ring side surface of the fourth filter unit 5D is defined as a preset height q. In this embodiment, q > d1+d2 is taken as an example, but the relationships among D1, D2, D3, and q may be the relationships described in any of the foregoing embodiments, as long as they conform to the following requirements: d1+d2+ (d3×15%) gtoreq is greater than or equal to d1+ (d2×50%) and the above-mentioned formula. As shown in fig. 15, since the two-stage cutting step is adopted, the upper and lower sides of the fourth filter unit 5D have a first width W1 and a second width W2, respectively, when viewed in the cross-section direction, and W1 is smaller than W2; in addition, the side walls of the fourth filter unit 5D have a step portion 5AX, respectively, and the step portion 5AX is located on the side wall of the substrate 11. In other different embodiments, the step portion may be located on a sidewall of the organic dye layer or a boundary between the organic dye layer and the substrate according to the relationship between D1, D2, D3, and q. In this embodiment, the fourth filter unit 5D has a width difference Δw on the left and right sides, and the application range or the preferred range of the width difference Δw can be referred to the above description, which is not repeated herein.

Fig. 16 and 17 are schematic partial cross-sectional views of a filter to be processed after an inorganic passivation layer forming step according to a fifth embodiment of a method for manufacturing a filter unit and a fifth embodiment of a filter unit, respectively.

As shown in fig. 16, the difference between the present embodiment and the first embodiment is that: before the separation step S11, the method further includes a light shielding structure forming step: on the opposite side of the substrate 11 from the side where the organic dye layer 12 is formed, an auxiliary organic dye layer 19, an isolation layer 20, a light shielding structure 17 and an auxiliary inorganic optical composite layer 16 are sequentially formed, and the light shielding structure 17 is completely covered by the auxiliary inorganic optical composite layer 16.

The isolation layer 20 is mainly used for isolating the auxiliary organic dye layer 19 from the light shielding structure 17, so that the interaction between a part of materials of the light shielding structure 17 and a part of materials of the auxiliary organic dye layer 19 in the process of forming the light shielding structure 17 is avoided. In order to avoid adversely affecting the optical performance of the filter unit, a material having excellent transmittance in the wavelength range of light (e.g., visible light) to be passed may be selected as the material of the insulating layer 20, or the thickness of the insulating layer 20 may be controlled to be very thin. In some practical applications, the material and the forming method of the isolation layer 20 may be the same as the material and the forming method of the first refraction layer or the second refraction layer, so that the isolation layer 20 can be regarded as a part of the auxiliary inorganic optical composite layer 16 to perform optical design at the position not covered by the isolation layer 20, which is helpful for the optical filter unit to perform the expected optical characteristics, and the isolation layer 20 can be formed without using additional equipment or process, which has no obvious influence on the complexity and cost of the process.

As shown in fig. 17, the fifth filtering unit 5E sequentially includes an auxiliary organic dye layer 19, an isolation layer 20, a light shielding structure 17, and an auxiliary inorganic optical composite layer 16 on a side of the substrate 11 opposite to the side including the organic dye layer 12. The light shielding structure 17 is completely covered by the auxiliary inorganic optical composite layer 16, so that the light shielding structure 17 will not be damaged during the subsequent cleaning process (wet or dry cleaning process). In other words, if the light shielding structure 17 is not completely covered by the auxiliary inorganic optical composite layer 16, the risk of damaging the light shielding structure 17 during the cleaning process is high, which results in a reduced yield.

The substrate 11, the organic dye layer 12, the inorganic optical composite layer 13, the auxiliary organic dye layer 19 and the auxiliary inorganic optical composite layer 16 of the fifth filter unit 5E are commonly used to determine which wavelength range of the light beam passes through the fifth filter unit 5E, so the main materials contained in the above layers of the fifth filter unit 5E can be determined according to the product to which the fifth filter unit 5E is applied, and the invention is not limited thereto. The specific materials of the above layers of the fifth filtering unit 5E can be referred to the above description, and will not be repeated.

As shown in fig. 17, the thickness of the inorganic optical composite layer 13, the thickness of the organic dye layer 12, and the thickness of the substrate 11 are defined as a first thickness D1, a second thickness D2, and a third thickness D3, respectively, and the total height of the inorganic protective layer 15 covering the ring side surface of the fifth filter unit 5E is defined as a preset height q. In the present embodiment, q > d1+d2 is taken as an example, but the relationship among D1, D2, D3, q may be selected according to the requirement, so long as the following is satisfied: d1+d2+ (d3×15%) gtoreq is greater than or equal to d1+ (d2×50%) and the above-mentioned formula. As shown in fig. 17, since the two-stage cutting step is adopted, the upper and lower sides of the fifth filter unit 5E have a first width W1 and a second width W2, respectively, when viewed in the cross-section direction, and W1 is smaller than W2; in addition, the side walls of the fifth filter unit 5E have a step portion 5AX, respectively, and the step portion 5AX is located on the side wall of the substrate 11. In other embodiments, the step portion 5AX may be located on the side wall of the organic dye layer 12 or at the boundary between the organic dye layer 12 and the substrate 11 according to the relationship between D1, D2, D3, q. In this embodiment, the fifth filter unit 5E has a width difference Δw on the left and right sides, and the application range or the preferred range of the width difference Δw can be referred to the above description, which is not repeated herein.

Fig. 18 to 20 are schematic flow diagrams of a sixth embodiment of a method for manufacturing a filtering unit, schematic partial cross-sectional diagrams of a to-be-processed filter formed after a cutting step, and schematic partial cross-sectional diagrams of a sixth embodiment of a filtering unit, respectively.

The manufacturing method of the filter unit of the present embodiment is used for cutting a filter 1 to be processed into a plurality of sixth filter units 5F, wherein the filter 1 to be processed at least comprises a substrate 11, an organic dye layer 12 and an inorganic optical composite layer 13, and the substrate 11 and the inorganic optical composite layer 13 are respectively disposed on two sides of the organic dye layer 12. The thickness of the inorganic optical composite layer 13, the thickness of the organic dye layer 12, and the thickness of the substrate 11 are defined as a first thickness D1, a second thickness D2, and a third thickness D3, respectively. The manufacturing method of the optical filter unit comprises the following steps: a cutting step S11 and a separating step S12. At least a portion of the sidewalls of the organic dye layer 12 is covered by a protective structure prior to the separating step S12.

In the sixth to eighth embodiments, the cutting step S11 is: cutting the optical filter 1 to be processed by utilizing a first cutting mode to form a plurality of grooves 14 on one side of the optical filter 1 to be processed, wherein the depth of each groove 14 is defined as a preset depth Q; the preset depth Q, the first thickness D1, the second thickness D2 and the third thickness D3 conform to: d1+d2+ (d3×15%) gtoreq is greater than or equal to d1+ (d2×50%); wherein after the cutting step S11, at least a portion of the organic dye layer 12 located in the trench 14 will form an organic coking structure 12A that is used as the protective structure. As shown in fig. 19, in the sixth embodiment, the preset depth Q, the first thickness D1, the second thickness D2, and the third thickness D3 conform to: d1+d2+ (d3×15%) gtoreq > d1+d2. In the sixth to eighth embodiments, the separation step S12 is: cutting the filter 1 to be processed along the plurality of grooves 14 by a second cutting means to cut the substrate 11, thereby cutting the filter 1 to be processed into a plurality of sixth filter units 5F, or a plurality of seventh filter units 5G, or a plurality of eighth filter units 5H; the second cutting mode is different from the first cutting mode. In an actual application, the first cutting mode and the second cutting mode may utilize lasers in different wavelength ranges (energy), for example, the first cutting mode may utilize ultraviolet lasers with higher energy, and the second cutting mode may utilize visible lasers with lower energy. More specifically, in one embodiment, the first cutting mode is cutting with Sup>A UV-A laser, for example, having Sup>A wavelength of 315-400 nm, and the second cutting mode is cutting with Sup>A green laser, for example, having Sup>A wavelength of 510-550 nm. In such an embodiment, the organic dye layer 12 includes light-absorbing dyes (e.g., infrared light and ultraviolet light absorbing dyes, but not limited thereto), binders, and optionally primer(s), and when the ultraviolet laser cuts through the organic dye layer 12, the light-absorbing dyes and binders in the organic dye layer 12 become organic coked structures 12A upon contact with the ultraviolet laser.

As described above, the manufacturing method of the filter unit of the present embodiment can make the outer sides (i.e. the sides of the organic dye layer) of the sixth filter unit 5F, the seventh filter unit 5G and the eighth filter unit 5H covered and protected by the protection structure (the organic coking structure 12A) by designing the cutting step S11 and the separating step S12, so as to avoid or greatly reduce the risk of damaging the organic dye layer 12 in the subsequent processing procedure. In this embodiment, the total height t of the organic coking structure 12A and the second thickness D2 of the organic dye layer 12 conform to: t=d2. In this embodiment and the seventh and eighth embodiments, the application range or the preferred range of the second thickness D2 can be referred to the above description, and the description is omitted herein. It should be noted that in the practical application of the thickness of the organic dye layer being 20 micrometers or more, in the cutting step S11, the notch width is advantageously smaller than 50 micrometers by using high-energy ultraviolet laser for cutting. In this way, the effects of minimizing the cross-sectional area and avoiding material edge chipping due to mechanical collision during subsequent processing can be achieved.

In different variations, the present embodiment and the following seventh and eighth embodiments may be added to the fourth embodiment or the fifth embodiment according to actual needs during the manufacturing process, and the auxiliary inorganic optical composite layer 16, the light shielding structure 17, and the auxiliary inorganic protective layer 18 may have corresponding structures.

In this embodiment, the organic coking structure 12A and the inorganic protective layer are both protective structures capable of protecting the organic dye layer, so that the risk of damaging the organic dye layer in the subsequent processing process can be reduced. Compared with the previous embodiments, the method for manufacturing the optical filter unit of the present embodiment can omit the step of forming the inorganic protective layer, so that the method has the technical effects of relatively simple manufacturing process, relatively fast manufacturing process, etc.

As shown in fig. 20, in the present embodiment, the total height t of the organic coking structure 12A is the same as the second thickness D2. As shown in fig. 20, since the two-stage cutting step is adopted, the upper and lower sides of the sixth filter unit 5F have a first width W1 and a second width W2, respectively, when viewed in the cross-section direction, and W1 is smaller than W2; in addition, the side walls of the sixth filter unit 5F have a step portion 5AX, respectively, and the step portion 5AX is located on the side wall of the substrate 11. In the present embodiment, there is a width difference Δw on the left and right sides of the sixth filter unit 5F, and the difference between the first width W1 and the second width W2 is determined by the cutting width of the first cutting method, which is about twice the width difference Δw. In embodiments where the dicing step is performed using a laser, the difference between the first width W1 and the second width W2 may be 5 to 30 microns, preferably 10 to 25 microns, and more preferably 15 to 20 microns.

Fig. 21 to 22 are schematic cross-sectional views of a seventh embodiment of a method for manufacturing a filter unit after a cutting step and schematic partial cross-sectional views of the seventh embodiment of the filter unit. The difference between this embodiment and the sixth embodiment is that: the predetermined depths of the grooves are different. Specifically, the preset depth Q, the first thickness and the second thickness of the cutting step are as follows: Q.apprxeq.D1+D2. That is, in the dicing step, the inorganic optical composite layer 13 and almost most of the organic dye layer 12 are completely cut off at the position where the trench 14 is to be formed, and the substrate 11 is not diced. In particular, the organic dye layer 12 at the bottom of the trench 14 may not be completely cut, so that the organic coking structure 12A is continuously formed at the bottom of the trench 14 and the lower portion of the inner sidewall. As such, the outer sides of the organic dye layers 12 (i.e., the organic dye layer ring sides) of the seventh filter units 5G of the present embodiment are covered by the organic coking structures 12A. That is, in the present embodiment, the total height t of the organic coking structure 12A and the second thickness D2 of the organic dye layer 12 conform to: t.apprxeq.D2. In particular, the organic coking structure 12A at the lower portion of the organic dye layer 12 is thicker, which can exert better protection effect, and can further reduce the risk of damaging the organic dye layer during subsequent processing.

As shown in fig. 22, in the present embodiment, the total height t of the organic coking structure 12A is substantially the same as the second thickness D2. As shown in fig. 22, since the two-stage cutting step is adopted, the upper and lower sides of the seventh filter unit 5G have a first width W1 and a second width W2, respectively, when viewed in the cross-section direction, and W1 is smaller than W2; in addition, each of the side walls of the seventh filter unit 5G has a step portion 5AX, and the step portion 5AX is located at the boundary between the substrate 11 and the organic dye layer 12. In this embodiment, the left and right sides of the seventh filtering unit 5G have a width difference Δw, and the application range or the preferred range of the width difference Δw cutting step can be referred to the description of the sixth embodiment, which is not repeated.

Fig. 23 to 24 are schematic partial cross-sectional views of an eighth embodiment of a method for manufacturing a filter unit after a cutting step and a schematic partial cross-sectional view of an eighth embodiment of a filter unit, respectively. The difference between this embodiment and the sixth embodiment is that: the predetermined depths of the grooves are different. Specifically, the preset depth Q, the first thickness D1 and the second thickness D2 of the cutting step are as follows: D1+D2> Q is equal to or greater than D1+ (D2 is 50%). That is, in the dicing step, at the position where the trench 14 is to be formed, the inorganic optical composite layer 13 is completely cut and the organic dye layer 12 is partially cut, at least 50% of the second thickness D2 of the organic dye layer 12 is cut, and the substrate 11 is not cut. At least a part of the outside (i.e., at least 50% of the second thickness D2) of the organic dye layer 12 (i.e., the organic dye layer annular side surface) of each of the seventh filter units 5G of the present embodiment is covered with the organic coking structure 12A. That is, in the present embodiment, the total height t of the organic coking structure 12A and the second thickness D2 of the organic dye layer 12 conform to: d2> t is greater than or equal to 50% of the relationship of D2. As described above, if the area of the organic dye layer ring side surface of the organic dye layer of the filter unit covered by the organic coking structure is greater than or equal to 50% than when the organic coking structure is not formed, the risk of damaging the organic dye layer during the subsequent processing can be significantly reduced. To reduce the risk of damaging the organic dye layer even further, in some applications the overall height t of the organic coking structure 12A may be in accordance with: a relation of t being greater than or equal to 65% of D2; in other applications, the overall height t of the organocoking structure 12A can be in accordance with: and t is equal to or greater than 80% of D2.

As shown in fig. 24, since the two-stage cutting step is adopted, the eighth filter unit 5H has a first width W1 and a second width W2 on the upper and lower sides thereof, respectively, when viewed in the cross-section direction, and W1 is smaller than W2; further, both side walls of the eighth filter unit 5H each have a step portion 5AX, and the position of this step portion 5AX is on the side wall of the organic dye layer 52. In this embodiment, the eighth filter unit 5H has a width difference Δw on the left and right sides, and the application range or the preferred range of the width difference Δw can be referred to the description of the sixth embodiment, which is not repeated herein.

In one specific application, the oxygen-to-carbon ratio (O/C ratio) of the organic coking structure in any of the above embodiments may be 1.18 to 1.66, so that the organic coking structure can be ensured to perform well in protecting the organic dye layer. In one specific application, the oxygen-to-carbon ratio of the organocoking structure may be 2.46 to 6.92 times that of the organic dye layer not irradiated by the laser. In practice, energy-Dispersive X-ray spectroscopy (EDX) can be used to perform elemental analysis of the organic coking structure to confirm the oxygen-carbon ratio of the organic dye layer and the organic coking structure.

Referring to fig. 20 and 22, the difference between the sixth filter unit 5F and the seventh filter unit 5G is that: the organocoking structure 12A is shaped differently in cross-section. As shown in fig. 19 and 20, in the sixth embodiment, Q > d1+d2, and therefore, in the cross-sectional view, the organic coking structure 12A of the sixth filter unit 5F appears nearly I-shaped. In contrast, in the seventh and eighth embodiments, d1+d2≡q+.gtoreq+.d1+ (d2+.50%) as shown in fig. 21 and 23, therefore, in the cross-sectional view, the organic coking structure 12A which has not undergone the separation step is substantially in a U shape, and as shown in fig. 22 and 24, the organic coking structure 12A in the seventh filter unit 5G and the eighth filter unit 5H is substantially in an L shape.

As is apparent from fig. 20, 22, 24 and the above description, if at least a portion of the side wall of the organic dye layer 12 in the filter unit is covered by the organic coking structure 12A (i.e., the total height t of the organic coking structure 12A and the second thickness D2 of the organic dye layer 12 satisfy the relationship that t is equal to or greater than d2×50%) as described above, it is reasonably assumed that the filter unit is manufactured by the manufacturing method according to any one of the sixth to eighth embodiments of the present disclosure.

It should be noted that, in the embodiments of the present invention, the first filter unit 5A, the second filter unit 5B, the third filter unit 5C, the fourth filter unit 5D, the fifth filter unit 5E, the sixth filter unit 5F, the seventh filter unit 5G, and the eighth filter unit 5H all belong to the filter units to be protected by the present invention, and the prefixes of "first", "second", and the like are only used to distinguish the filter units of different embodiments, and are not used to indicate the ranking of importance.

In summary, according to the method for manufacturing the optical filter unit and the optical filter unit in the embodiments of the present invention, the protection structure (inorganic protection layer or organic coking structure) can effectively prevent the organic dye layer from being damaged in the subsequent processing process, so that the manufacturing yield of the optical filter unit can be greatly improved.

The foregoing description is only of the preferred embodiments of the invention and is not intended to limit the scope of the invention, so that all changes which come within the meaning and range of equivalency of the description and drawings are intended to be embraced therein.

Claims

1. A manufacturing method of a light filtering unit is used for cutting a light filtering piece to be processed into a plurality of light filtering units, and is characterized in that: the filter to be treated at least comprises a substrate, an organic dye layer and an inorganic optical composite layer, wherein the thickness of the inorganic optical composite layer, the thickness of the organic dye layer and the thickness of the substrate are respectively defined as a first thickness (D1), a second thickness (D2) and a third thickness (D3), the substrate and the inorganic optical composite layer are respectively arranged on two sides of the organic dye layer, and the manufacturing method of the filter unit comprises the following steps:

And a cutting step: cutting the filter to be processed by utilizing a first cutting mode to form a plurality of grooves on one side of the filter to be processed, wherein the depth of each groove is defined as a preset depth (Q); the preset depth (Q), the first thickness (D1), the second thickness (D2) and the third thickness (D3) correspond to: d1+d2+ (d3×15%) gtoreq is greater than or equal to d1+ (d2×50%);

a separation step: cutting the filter to be processed along the grooves by utilizing a second cutting mode so as to cut off the substrate, and cutting the filter to be processed into a plurality of filter units; the second cutting mode is different from the first cutting mode, wherein at least a part of the side wall of the organic dye layer is covered by a protective structure before the separation step is carried out;

wherein, when viewed from the cross section direction, the upper side and the lower side of the light filtering unit are respectively provided with a first width (W1) and a second width (W2), and the first width (W1) is smaller than the second width (W2); the substrate is positioned at the lower side of the light filtering unit.

2. The method of manufacturing a filter unit of claim 1, wherein: each groove of the filter to be processed after the cutting step comprises a first section and a second section, wherein the first section is adjacent to the inorganic optical composite layer, and the second section is adjacent to the substrate; a width of the groove gradually expands from a position close to the substrate to a direction far away from the substrate in the second section.

3. The method of manufacturing a filter unit of claim 1, wherein: the first cutting mode is to use a cutter, the second cutting mode is to use laser to irradiate the positions of the substrate corresponding to the grooves so as to destroy the structure of the positions of the substrate corresponding to the grooves, and then stretch the filter to be processed.

4. The method of manufacturing a filter unit of claim 1, wherein: between the cutting step and the separating step, further comprising:

an inorganic protective layer forming step: forming an inorganic protective layer on one side of the filter to be treated, on which a plurality of grooves are formed, to cover the inner wall of each groove, wherein the inorganic protective layer is used as the protective structure; the thickness of the inorganic protective layer is 0.2% -20% of the width of each groove;

wherein at least a portion of an organic dye layer side surface of the organic dye layer included in each of the filter units formed by the separating step is covered with the inorganic protective layer.

5. The method of manufacturing a filter unit according to claim 4, wherein: after the cutting step, a portion of the substrate is exposed in the trench; the side surface of the inorganic optical composite layer ring of the inorganic optical composite layer contained in each filter unit is covered by the inorganic protective layer; a part of the substrate included in each of the filter units is covered with the inorganic protective layer included in the filter unit.

6. The method of manufacturing a filter unit of claim 1, wherein: utilizing lasers with different wavelengths in the cutting step and the separating step respectively, wherein after the cutting step, at least one part of the organic dye layer in the groove is formed into an organic coking structure, and the organic coking structure is used as the protection structure; and after the filter to be treated is cut into a plurality of filter units, at least one part of the side surface of the organic dye layer ring of the organic dye layer contained in each filter unit is covered by the organic coking structure.

7. The method of manufacturing a filter unit of claim 1, wherein: a plurality of rugged notches are formed on one edge of the filter unit, a path cut by the second cutting mode at the edge is defined as a separation path, a straight line which is parallel to the separation path and extends from a point closest to the inner side of the filter unit in the edge is defined as a notch inner edge line, a straight line which is parallel to the separation path and extends from a point closest to the outer side of the filter unit in the edge is defined as a notch outer edge line, a distance between the notch inner edge line and the notch outer edge line is defined as a notch width, and the notch width is smaller than 50 microns.

8. A method of manufacturing a filter unit according to any one of claims 1 to 7, wherein: the second thickness (D2) is 20 micrometers or more.

9. A filter unit, characterized by: comprising:

a substrate;

an organic dye layer arranged on one side of the substrate, wherein the thickness of the organic dye layer is more than 20 micrometers;

a protective structure covering at least a portion of a sidewall of the organic dye layer;

an inorganic optical composite layer disposed on a side of the organic dye layer opposite to the substrate;

10. The filter unit of claim 9, wherein: the side wall of the light filtering unit is provided with a step part, the position of the step part is positioned on the side wall of the organic dye layer, or the position of the step part is positioned on the side wall of the substrate, or the position of the step part is positioned at the junction of the organic dye layer and the substrate.

11. The filter unit of claim 9, wherein: the difference between the first width (W1) and the second width (W2) is 5-150 micrometers.

12. The filter unit of claim 9, wherein: the filter to be processed is separated into a plurality of filter units by a separation step, the separation step cuts and separates the substrate, a plurality of rugged gaps are formed at one edge of the filter units, a path cut by the separation step at the edge is defined as a separation path, a straight line parallel to the separation path, which extends at a point closest to the inner side of the filter units in one edge, is defined as a gap inner edge line, a straight line parallel to the separation path, which extends at a point closest to the outer side of the filter units in the edge, is defined as a gap outer edge line, a distance between the gap inner edge line and the gap outer edge line is defined as a gap width, and the gap width is smaller than 50 microns.

13. The filter unit of claim 9, wherein: the filter unit further comprises:

an inorganic protective layer which completely covers a top surface of the inorganic optical composite layer and an inorganic optical composite layer ring side surface and covers at least a portion of an organic dye layer ring side surface of the organic dye layer, the inorganic protective layer being used as the protective structure;

Wherein the thickness of the inorganic optical composite layer, the thickness of the organic dye layer and the thickness of the substrate are respectively defined as a first thickness (D1), a second thickness (D2) and a third thickness (D3); the total height of the inorganic protective layer covering the side surface of the ring of the light filtering unit is defined as a preset height (q); the first thickness (D1), the second thickness (D2), the third thickness (D3) and the preset height (q) correspond to: d1+d2+ (d3×15%) gtoreq.gtoreq.gtoreq.gtoreq.1+ (d2×50%) relational expression.

14. The filter unit of claim 13, wherein: the filter unit is divided into a first part, a second part and a third part by a width from one side with the inorganic optical composite layer to one side of the substrate in sequence, wherein the width of the first part is equal to the minimum width of the second part, and the width of the third part is equal to the maximum width of the second part; the width of the second part of the optical filter unit gradually increases from one side close to the inorganic optical composite layer to one side of the substrate; the first portion comprises a portion of the inorganic optical composite layer and the organic dye layer; the second portion comprises a further portion of the organic dye layer; the third portion includes the remainder of the organic dye layer and the substrate; wherein a thickness of an unexposed portion of the organic dye layer ring side of the organic dye layer is not less than 50% of the second thickness (D2) of the organic dye layer; wherein the first thickness (D1), the second thickness (D2), the third thickness (D3) and the preset height (q) correspond to: D1+D2 > q.gtoreq.gtoreq.D1+ (D2.times.50%) relationship.

15. The filter unit of claim 13, wherein: the filter unit is divided into a first part, a second part and a third part by a width from one side with the inorganic optical composite layer to one side of the substrate in sequence, wherein the width of the first part is equal to the minimum width of the second part, and the width of the third part is equal to the maximum width of the second part; the width of the second part of the optical filter unit gradually increases from one side close to the inorganic optical composite layer to one side of the substrate; the first portion comprises the inorganic optical composite layer and the organic dye layer; the second portion comprises a portion of the substrate; the third portion comprises another portion of the substrate; wherein the first thickness (D1), the second thickness (D2), the third thickness (D3) and the preset height (q) correspond to: d1+d2+ (d3×15%) gtoreq > d1+d2.

16. The filter unit of claim 13, wherein: the filter unit is divided into a first part, a second part and a third part by a width from one side with the inorganic optical composite layer to one side of the substrate in sequence, wherein the width of the first part is equal to the minimum width of the second part, and the width of the third part is equal to the maximum width of the second part; the width of the second part of the optical filter unit gradually increases from one side close to the inorganic optical composite layer to one side of the substrate; the first portion comprises a portion of the inorganic optical composite layer and the organic dye layer; the second portion comprises another portion of the organic dye layer; the third portion comprises the substrate; wherein the first thickness (D1), the second thickness (D2), the third thickness (D3) and the preset height (q) correspond to: q=d1+d2.

17. The filter unit of claim 13, wherein: the inorganic optical composite layer comprises a plurality of first refraction layers and a plurality of second refraction layers, wherein the refractive index of any one of the first refraction layers is higher than that of any one of the second refraction layers; the inorganic protection layer and one of the first refraction layers are made of the same material, or the inorganic protection layer and one of the second refraction layers are made of the same material.

18. The filter unit of claim 9, wherein: the filter unit further comprises:

an organic coking structure covering at least a portion of an organic dye layer ring side of the organic dye layer; the organic coking structure is a structure formed by the organic dye layer after laser irradiation, and is used as the protection structure;

wherein the total height of the organic coking structure covering the organic dye layer is more than 50% of the thickness of the organic dye layer.

19. The filter unit of claim 18, wherein: the oxygen-carbon ratio of the organic coking structure is 2.46-6.92 times of that of the organic dye layer which is not irradiated by laser.

20. The filter unit of claim 18, wherein: the oxygen-carbon ratio of the organic coking structure is 1.18-1.66.

21. The filter unit of claim 18, wherein: the organocoking structure exhibits an L-shape when viewed in cross-section.

22. The filter unit of claim 18, wherein: the organocoking structure exhibits an I-shape when viewed in cross-section.