Optical devices and their manufacturing methods

Abstract

The objective is to provide a technology that minimizes damage to optical elements during the removal of a color filter layer in the manufacture of an optical device. The solution is an optical device OD comprising: a silicon substrate 1 on one of its main surfaces having a plurality of optical elements disposed thereon; an inorganic sealing layer 8 disposed on the main surface; a color filter layer 11 disposed on the inorganic sealing layer 8; and a light-transmitting functional layer 9 disposed between the inorganic sealing layer 8 and the color filter layer 11, comprising at least one of an inorganic material and silicone resin.

Description

Technical Field

[0001] This invention relates to optical devices. Prior Technology

[0002] In recent years, there has been a growing demand for thinner / lighter or curved displays for electronic devices such as mobile phones and portable information terminals. Current mainstream LCD displays struggle to meet these demands. To address this need, the development and mass production of display devices using organic light-emitting diodes (EL) or light-emitting diodes (LEDs) as self-emissive elements are underway.

[0003] In electronic devices, the thinness and lightweight design of display devices are particularly important for high-resolution, small-sized displays (around 0.5 inches in diameter), such as head-mounted displays and electronic viewfinders (hereinafter referred to as microdisplays). Therefore, the application of display devices using self-emissive elements in microdisplays is highly anticipated.

[0004] For organic EL display devices that can be applied to microdisplays, either of the following two display methods can be used.

[0005] One display method involves forming white-light-emitting organic EL elements on a silicon substrate where transistors are formed, and then forming a color filter layer with three or more colors, such as red, green, and cyan, on top of these elements to display colors. Furthermore, this type of color filter layer is generally referred to as an on-chip color filter (OCF).

[0006] The other method of display is to form organic EL elements that emit different colors of light, such as red, green and cyan, to display colors.

[0007] To form well-shaped micropixels using the latter display method, it is necessary to, for example, impart photosensitivity to the light-emitting material. However, this is difficult. Moreover, microdisplays have extremely small pixels, with pixel sizes ranging from several μm to 30 μm. Therefore, microdisplays using the latter display method have not yet achieved formal mass production.

[0008] In addition, medium to large-sized organic EL display devices also employ a display method that uses an array substrate containing white-emitting organic EL elements to bond colors to a color filter substrate containing a color filter layer. However, in cases like microdisplays where pixels are extremely small, it is extremely difficult to bond these substrates with high precision to prevent color shift.

[0009] For the reasons mentioned above, currently many microdisplays containing organic EL elements use a display method that forms a color filter layer on top of the white-emitting organic EL element and uses the color filter layer for color separation, which is the OCF method.

[0010] In terms of the formation method of OCF, photolithography is the mainstream method, which uses photoresist formed by dispersing pigments in photosensitive resin. By using photolithography, it is possible to form micro-pixels with a size of about 1μm.

[0011] However, if pixel miniaturization is carried out, the probability of defects such as foreign matter in the color filter layer increases, and the decline in yield becomes more severe. Therefore, in cases where the yield does not reach the predetermined value, it is desirable to perform a reprocessing step: removing the color filter layer from the intermediate product and reforming the color filter layer (see Patent Document 1). [Previous Technical Documents] [Patent Literature]

[0012] [Patent Document 1] Japanese Patent Application Publication No. 2015-103788 Summary of the Invention

[0013] [The problem the invention aims to solve]

[0014] The present invention aims to provide a technology that makes it less likely for damage to optical elements to occur during the manufacturing of optical devices, which is accompanied by the removal of color filter layers. [Methods used to solve problems]

[0015] According to one aspect of the present invention, an optical device is provided, comprising: a silicon substrate on one of its main surfaces having a plurality of optical elements disposed thereon; an inorganic sealing layer disposed on the main surface; a color filter layer disposed on the inorganic sealing layer; and a light-transmitting functional layer disposed between the inorganic sealing layer and the color filter layer, comprising at least one of an inorganic material and a silicone resin.

[0016] According to other embodiments of the present invention, an optical device relating to the above-described embodiments is provided, wherein the aforementioned light-transmitting functional layer further comprises a resin, and comprises at least one of the aforementioned inorganic material and the aforementioned silicone resin as a filler dispersed in the aforementioned resin.

[0017] According to another embodiment of the present invention, an optical device relating to the above embodiment is provided, wherein the proportion of the aforementioned filler in the aforementioned light-transmitting functional layer is in the range of 5% to 90% by mass.

[0018] According to another aspect of the present invention, an optical device for any of the above aspects is provided, wherein the aforementioned resin is an acrylic resin.

[0019] According to another embodiment of the present invention, an optical device is provided for any of the above embodiments, wherein the aforementioned light-transmitting functional layer has a Vickers hardness of 45 kgf / mm² or higher.

[0020] According to another aspect of the present invention, an optical device for any of the above aspects is provided, wherein the aforementioned light-transmitting functional layer comprises an inorganic oxide as the aforementioned inorganic material.

[0021] According to another aspect of the present invention, an optical device for any of the above aspects is provided, wherein the aforementioned light-transmitting functional layer comprises silica.

[0022] According to another embodiment of the present invention, an optical device is provided for any of the above embodiments, wherein the thickness of the aforementioned light-transmitting functional layer is in the range of 0.1 μm to 5.0 μm.

[0023] According to another embodiment of the present invention, an optical device for any of the above embodiments is provided, which further comprises: a light-transmitting layer containing organic matter, located between the aforementioned light-transmitting functional layer and the aforementioned color filter layer.

[0024] According to another aspect of the present invention, an optical device for any of the above aspects is provided, wherein each of the aforementioned plurality of optical elements is an organic electroluminescent element.

[0025] According to another embodiment of the present invention, a method for manufacturing an optical device is provided, comprising: preparing a structure having a silicon substrate having a plurality of optical elements disposed on a main surface of one side, and an inorganic sealing layer disposed on the main surface; forming a light-transmitting functional layer comprising at least one of an inorganic material and a silicone resin on the inorganic sealing layer to obtain a first product; forming a color filter layer on the light-transmitting functional layer to obtain a second product; inspecting the color filter layer for defects, selecting products with defects in the color filter layer from the second product as products requiring repair; and removing the color filter layer from the products requiring repair to obtain a recycled product having the same structure as the first product. [Effects of the Invention]

[0026] According to the present invention, a technique can be provided that makes it less likely for damage to optical elements to occur during the manufacture of optical devices, which is accompanied by the removal of color filter layers. Simple Explanation of the Diagram

[0027] Figure 1 is a schematic cross-sectional view of an optical device according to one embodiment of the present invention. Figure 2 is a simplified cross-sectional view of the item requiring repair. Figure 3 is a schematic cross-sectional view showing the structure obtained by removing the protective film layer from the product to be repaired. Figure 4 is a schematic cross-sectional view of the structure obtained by further removing the color filter layer and the light-transmitting layer from the structure in Figure 4. Implementation

[0028] [The form in which the invention is carried out]

[0029] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are further elaborations of any of the above embodiments. The matters described below may be individually or in combination and incorporated into each of the above embodiments.

[0030] Furthermore, the embodiments shown below are merely examples illustrating the configurations used to embody the technical concept of the present invention. The technical concept of the present invention is not limited by the material, shape, and structure of the constituent components described below. Various modifications can be made to the technical concept of the present invention within the technical scope defined by the claims described in the scope of the claims.

[0031] Furthermore, elements with the same or similar functions are indicated by the same reference symbols in the following diagrams, omitting repeated explanations. Also, the diagrams are illustrative, and the relationship between dimensions in one direction and dimensions in other directions, and the relationship between the dimensions of one component and the dimensions of other components, may differ from the actual object.

[0032] Figure 1 is a schematic cross-sectional view of an optical device according to one embodiment of the present invention. The optical device OD shown in Figure 1 is an organic EL microdisplay. This microdisplay includes an array substrate 3, an insulating layer 16, a partition layer 4, a cathode 5, an organic light-emitting layer (organic EL layer) 6, an anode 7, an inorganic sealing layer 8, a light-transmitting functional layer 9, a light-transmitting layer 10, a color filter layer 11, a protective film layer 12, a sealing layer 13, and a protective glass 14.

[0033] The array substrate 3 includes a silicon substrate 1 and an array section 2. The array section 2 includes pixel circuits and wiring that supplies signals and power to the pixel circuits. The pixel circuits include driving elements, transistors as switches, capacitors, and wiring connecting them to each other. The transistors, for example, are field-effect transistors that include a portion of the surface area of ​​the silicon substrate 1 as a source region, a channel region, and a drain region.

[0034] An insulating layer 16 is disposed on the array section 2. The insulating layer 16 may have a single-layer structure or a multi-layer structure. The insulating layer 16 may be, for example, at least one of a passivation film and a planarization layer.

[0035] The partition layer 4 is disposed on the insulating layer 16. Through holes are provided in the partition layer 4 at the positions corresponding to pixels. At least its surface comprises an insulator.

[0036] The cathode 5 is attached to the insulating layer 16 and positioned at the location of a through-hole provided in the partition layer 4. The cathode 5 is connected to the pixel circuit through the through-hole provided in the insulating layer 16. According to one example, the cathode 5 comprises a metal or alloy such as aluminum.

[0037] The organic light-emitting layer 6 is disposed on the cathode 5. If the organic light-emitting layer 6 is one that emits white light by charge injection, it can be a generally known object, such as those disclosed in Japanese Patent Application Publication No. 4-284395 (paragraphs 0015 to 0016) or Japanese Patent Application Publication No. 2005-150078 (paragraphs 0017 to 0018).

[0038] The anode 7 covers the exposed portion of the partition layer 4 and the organic light-emitting layer 6. The anode 7 is connected to the feed line provided in the array section. The cathode 5, the organic light-emitting layer 6 disposed thereon, and the portion of the anode 7 that is separated from the cathode 5 by the organic light-emitting layer 6 constitute an organic EL element as an optical element.

[0039] An inorganic sealing layer 8 is disposed on the anode 7. The inorganic sealing layer 8 is generally provided to address the problem of organic EL elements being extremely susceptible to moisture. The inorganic sealing layer 8 is, for example, composed of inorganic compounds such as inorganic oxides and inorganic nitrides. The inorganic sealing layer 8 can have a single-layer structure or a multi-layer structure. Examples of inorganic sealing layers 8 include those disclosed in Japanese Patent Application Publication No. 2014-175296 (paragraphs 0010 to 0028).

[0040] The light-transmitting functional layer 9 is disposed on the inorganic sealing layer 8. The light-transmitting functional layer 9 allows white light emitted by the organic EL element to pass through.

[0041] The light-transmitting functional layer 9 is formed by etching and other processes during the remanufacturing process of removing the color filter layer 11 to form a new color filter layer 11, thereby preventing severe deterioration or damage to the inorganic sealing layer 8. In this way, the light-transmitting functional layer 9 prevents the inorganic sealing layer 8, which is supposed to protect organic EL elements from moisture, from being completely lost due to the aforementioned etching and other processes.

[0042] The light-transmitting functional layer 9 comprises at least one of an inorganic material and a silicone resin. Inorganic compounds, such as: silicon oxide (SiO₂), zirconium oxide (ZrO₂), titanium oxide (TiO₂), aluminum oxide (Al₂O₃), iron oxide (Fe₂O₃, FeO, Fe₃O₄), copper oxide (CuO, Cu₂O), zinc oxide (ZnO), yttrium oxide (Y₂O₃), niobium oxide (Nb₂O₅), molybdenum oxide (MoO₃), indium oxide (In₂O₃, In₂O), tin oxide (SnO₂), tantalum oxide (Ta₂O₅), tungsten oxide (WO₃, W₂O₅), lead oxide (PbO, PbO₂), bismuth oxide (Bi₂O₃), cerium oxide (CeO₂, Ce₂O₃), antimony oxide (Sb₂O₅, Sb₂O₅), germanium oxide (GeO₂). 2. Inorganic oxides such as GeO; inorganic nitrides such as silicon nitride and boron nitride; titanates such as barium titanate; or composite oxides composed of two or more metallic elements such as titanium / silicon composite oxides and yttrium-stabilized zirconium oxide. The light-transmitting functional layer 9 preferably contains at least one of inorganic oxides and composite oxides, and more preferably contains silica.

[0043] The light-transmitting functional layer 9 may also be a layer containing only at least one of the aforementioned inorganic material and silicone resin. However, it is preferable that the light-transmitting functional layer 9 further contains resin, and includes at least one of the aforementioned inorganic material and silicone resin as a filler dispersed in the resin. That is, the light-transmitting functional layer 9 is preferably a filler containing a light-transmitting layer. When the light-transmitting functional layer 9 is composed of a mixture of filler and resin, stress-induced cracking is less likely to occur.

[0044] The filler may be particles containing the aforementioned inorganic materials, particles containing the aforementioned silicone resin, or a mixture thereof. The filler is preferably silica particles, silicone resin particles, or a mixture thereof, and more preferably silica particles. The filler is preferably spherical amorphous particles.

[0045] The filler preferably has an average particle size in the range of 1 nm to 200 nm, more preferably in the range of 5 nm to 30 nm. If the average particle size of the filler is increased, the smoothness of the surface of the light-transmitting functional layer 9 will decrease. If the average particle size of the filler is decreased, the viscosity of the coating liquid used to form the light-transmitting functional layer 9 will increase. Furthermore, when the refractive index of the filler is significantly different from that of the resin, if the average particle size of the filler is decreased, there is a possibility that the light scattering property of the light-transmitting functional layer 9 will become excessively high.

[0046] Here, the "average particle size" is determined by directly measuring the size of primary particles in electron microscope images obtained using a transmission electron microscope (TEM). Specifically, the minor axis diameter and major axis diameter of each primary particle in the electron microscope image are measured, and the average of the minor axis diameter and major axis diameter is taken as the particle size of that primary particle. Next, for approximately 20 primary particles, the volume of each particle is approximated by the volume of a cube with one side length as the particle size obtained as described above, and the volume-average particle size is taken as the average particle size.

[0047] Regarding the resin, it is desirable to have high visible light transmittance and sufficient resistance to heat treatment or chemical treatment in the formation steps of the color filter layer. The uncured resin can be a photosensitive and developable resin such as an ultraviolet-curing resin, or a thermosetting resin. Examples of resins include acrylic resins and epoxy resins. Acrylic resins are preferred.

[0048] The filler content in the light-transmitting functional layer 9 is preferably 5% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more. This content is preferably 90% by mass or less, preferably 75% by mass or less, and even more preferably 50% by mass or less. According to one example, this content is in the range of 5% to 90% by mass; according to other examples, it is in the range of 25% to 75% by mass; and according to yet another example, it is in the range of 30% to 50% by mass. Increasing this content enhances the effect of suppressing the deterioration or damage of the inorganic sealing layer 8 caused by etching or cleaning during the remanufacturing process. However, if the above content is excessively increased, the viscosity of the coating liquid used to form the light-transmitting functional layer 9 will increase, or the filler will become more prone to detachment from the light-transmitting functional layer 9.

[0049] The absolute value of the difference between the refractive index of the resin at a wavelength of 550 nm and the refractive index of the filler at the same wavelength is preferably 0.3 or less, and more preferably 0.1 or less. If this value is reduced, light scattering in the light-transmitting functional layer 9 will decrease. The absolute value of this refractive index difference should be zero or more. For a combination of representative materials, the absolute value of this refractive index difference is 0.1 or less.

[0050] The light-transmitting functional layer 9 preferably has a Vickers hardness of 45 kgf / mm² or higher. A high Vickers hardness in the light-transmitting functional layer 9 provides particularly excellent resistance to the degradation or damage of the inorganic sealing layer 8 caused by etching or cleaning during the remanufacturing process. There is no upper limit to the Vickers hardness of the light-transmitting functional layer 9, but in one example, it is 300 kgf / mm² or lower.

[0051] The thickness of the light-transmitting functional layer 9 is preferably in the range of 0.1 μm to 5.0 μm, and more preferably in the range of 0.2 μm to 0.5 μm. In one example, the thickness of the light-transmitting functional layer 9 may decrease by approximately 0.05 μm due to a single remanufacturing process. If the thickness of the light-transmitting functional layer 9 is above the aforementioned lower limit before and after the remanufacturing process, the ability to suppress the deterioration or damage of the inorganic sealing layer 8 can be reliably prevented from being lost from the light-transmitting functional layer 9 during the remanufacturing process. If the light-transmitting functional layer 9 is excessively thickened, light scattering within the light-transmitting functional layer 9 will increase.

[0052] A light-transmitting layer 10 is disposed on the light-transmitting functional layer 9. The light-transmitting layer 10 allows white light emitted by the organic EL element to pass through the inorganic sealing layer 8 and the light-transmitting functional layer 9. The light-transmitting layer 10 serves as a planarization layer. The light-transmitting layer 10 contains an organic material such as resin. For this resin, for example, the resin contained in the light-transmitting functional layer 9, as described above, can be used. Alternatively, the resin disclosed in Japanese Patent No. 5044893 (paragraphs 0039 to 0040) can also be used. Preferably, the resin contained in the light-transmitting layer 10 is the same as the resin contained in the light-transmitting functional layer 9. The light-transmitting layer 10 can be omitted.

[0053] A color filter layer 11 is disposed on the light-transmitting layer 10. The color filter layer 11 includes a first colored portion 11A, a second colored portion 11B, and a third colored portion 11C. For example, the first colored portion 11A, the second colored portion 11B, and the third colored portion 11C are respectively a cyan colored layer, a green colored layer, and a red colored layer. If white light is incident on the cyan colored layer, the green colored layer, and the red colored layer, they will allow cyan light, green light, and red light to pass through, respectively.

[0054] The first colored portion 11A, the second colored portion 11B, and the third colored portion 11C form a strip array. Each of the first colored portion 11A, the second colored portion 11B, and the third colored portion 11C is separated from a plurality of organic EL elements arranged in a row by an inorganic sealing layer 8, a light-transmitting functional layer 9, and a light-transmitting layer 10. The first colored portion 11A, the second colored portion 11B, and the third colored portion 11C may also form a delta array or a mosaic array.

[0055] The first colored portion 11A, the second colored portion 11B, and the third colored portion 11C can be formed by photolithography using a colored photosensitive resin composition. The colored photosensitive resin composition can include, for example, pigments, transparent resins, photopolymerizable monomers, photoinitiators, and solvents.

[0056] The protective film layer 12 is disposed on the color filter layer 11. The protective film layer 12 allows colored light that has passed through the color filter layer 11 to pass through. The protective film layer 12 serves as a planarization layer. The protective film layer 12 contains organic materials such as resin.

[0057] A bonding layer 13 is disposed on the protective film layer 12. The bonding layer 13 allows colored light that has passed through the color filter layer 11 and the protective film layer 12 to pass through. The bonding layer 13 is, for example, made of an adhesive.

[0058] The protective glass 14 is disposed on the sealing layer 13. The protective glass 14 allows colored light that has passed through the color filter layer 11, the protective film layer 12, and the sealing layer 13 to pass through. The protective glass 14 protects the organic EL element or the color filter layer 11 from damage.

[0059] In the organic EL microdisplay constructed as described above, the color filter layer 11 converts the white light emitted by the organic EL element into colored light. This microdisplay can thus display color images with high color reproduction. Furthermore, this microdisplay is suitable for use in applications such as head-mounted displays or electronic viewfinders.

[0060] Furthermore, since the color filter layer 11 is re-fabricated during the manufacturing process of this microdisplay, the inorganic sealing layer 8 is less prone to deterioration or damage. Therefore, it can be manufactured with a high yield.

[0061] The manufacturing method including the reprocessing process will be described below with reference to Figures 2 to 4.

[0062] Figure 2 is a schematic cross-sectional view of the workpiece requiring repair. Figure 3 is a schematic cross-sectional view of the structure obtained by removing the protective film layer from the workpiece requiring repair. Figure 4 is a schematic cross-sectional view of the structure obtained by further removing the color filter layer and the light-transmitting layer from the structure of Figure 4. Furthermore, the substrate 100 shown in Figures 2 to 4 is the structure shown in Figure 1, which includes the array substrate 3, the insulating layer 16, the partition layer 4, the cathode 5, the organic light-emitting layer 6, and the anode 7.

[0063] First, a structure is prepared comprising a silicon substrate having a plurality of optical elements disposed on one of its main surfaces, and an inorganic sealing layer disposed on the aforementioned main surface. That is, a structure comprising a substrate 100 and an inorganic sealing layer 8 disposed thereon is prepared here.

[0064] Next, a light-transmitting functional layer 9 is formed on the inorganic sealing layer 8 to obtain the first product. Next, a color filter layer 11 is formed on the light-transmitting functional layer 9 to obtain the second product. Here, a light-transmitting layer 10 is formed on the light-transmitting functional layer 9 before the color filter layer 11 is formed, and a protective film layer 12 is further formed on the color filter layer 11.

[0065] Then, the color filter layer 11 is inspected for defects, and those with defects in the color filter layer 11 from the second product are selected as products requiring repair. Products requiring repair, for example, have the structure shown in FIG2.

[0066] For good products, the protective glass 14 is bonded together through the sealing layer 13. Then, as needed, the optical device OD organic EL type microdisplay shown in FIG1 is obtained by cutting or other means.

[0067] Furthermore, from the product requiring repair, the color filter layer 11 is removed to obtain a recycled product having the same structure as the first product. The removal of the color filter layer 11 is performed by dry etching and cleaning in the following order: Dry etching is ashing, i.e., O2 plasma etching. Cleaning, for example, is two-fluid cleaning using water as the cleaning solution.

[0068] Since the protective film layer 12 contains organic matter, it is removed from the substrate 100, etc., by ashing. As a result, the structure shown in Figure 3 can be obtained.

[0069] If the ashing process continues further, the organic matter will be removed from the color filter layer 11. The pigment contained in the color filter layer 11 contains metal. The metal can be oxidized by dry etching, but dry etching alone may not remove it from the substrate 100, etc. The residual metal is removed from the substrate 100, etc. by subsequent cleaning. In addition, the light-transmitting layer 10 also contains organic matter, so it is removed from the substrate 100, etc. by dry etching.

[0070] As described above, the light-transmitting functional layer 9 comprises at least one of inorganic matter and silicone resin. The inorganic matter cannot be removed by ashing. Furthermore, the silicone resin oxide includes silica, which also cannot be removed by ashing. In addition, if the light-transmitting functional layer 9 contains organic matter, this organic matter can be removed by ashing. However, since the light-transmitting functional layer 9 comprises at least one of inorganic matter and silicone resin, the removal of organic matter cannot be carried out quickly. Therefore, while the surface area of ​​the light-transmitting functional layer 9 can be removed by ashing and cleaning, residues will remain in other areas.

[0071] Therefore, as shown in Figure 4, a recycled product containing a substrate 100, an inorganic sealing layer 8, and a light-transmitting functional layer 9 can be obtained.

[0072] To remove the color filter layer 11, the cycle including dry etching and cleaning can be repeated two or more times. As mentioned above, the metal contained in the color filter layer 11 cannot be removed from the substrate 100 by dry etching alone, and there is a possibility that it will remain as metal oxide. The residual metal oxide will hinder the removal of organic matter by dry etching. If the cycle including dry etching and cleaning is repeated two or more times, and the removal of the color filter layer 11 is performed in multiple times, the amount of metal oxide generated in each dry etching can be reduced. Therefore, the removal of organic matter due to residual metal oxide can be prevented.

[0073] Next, for the aforementioned recycled material, the light-transmitting layer 10, the color filter layer 11, and the protective film layer 12 are formed in that order. Then, the protective glass 14 is bonded to this structure via the sealing layer 13. Finally, as needed, by cutting or other methods, the optical device OD shown in FIG1 is obtained as an organic EL type microdisplay.

[0074] This method involves manufacturing optical devices (ODs) from the aforementioned good products, producing recycled products from the products requiring repair, and then using these recycled products to manufacture optical devices (ODs). Therefore, a high yield can be achieved by following this method.

[0075] Furthermore, the inventors have discovered that when the transparent functional layer 9 is omitted, the inorganic sealing layer 8 is exposed to O2 plasma during the ashing process in the above-mentioned remanufacturing process, resulting in significant deterioration or damage, and consequently, a significant decrease in the function of protecting the organic EL element. Moreover, the inventors have discovered that when the transparent functional layer 9 is omitted, and a strong alkaline solution is used instead of ashing to peel off the color filter layer 11 during the above-mentioned remanufacturing process, in addition to the inorganic sealing layer 8 and the organic EL element, the circuitry contained in the array section 2 is also damaged.

[0076] Referring to Figures 2 to 4, the above method does not use strong alkaline solutions. Instead, it removes the color filter layer 11 and the like through ashing and cleaning. Furthermore, by providing a light-transmitting functional layer 9, the inorganic sealing layer 8 is prevented from being exposed to the O2 plasma. Therefore, this method can also achieve a high yield in the reprocessing stage.

[0077] Furthermore, as mentioned above, the thickness of the light-transmitting functional layer 9 is slightly reduced due to the ashing process used to remove the color filter layer 11 and subsequent cleaning. However, the function of protecting the inorganic sealing layer 8 is not lost from the light-transmitting functional layer 9 due to these processes, and the optical properties of the light-transmitting functional layer 9 do not change significantly. In particular, when the light-transmitting functional layer 9 contains a mixture of fillers and resin, the new surface formed by the removal of the surface area due to ashing and subsequent cleaning has surface properties almost identical to the surface of the light-transmitting functional layer 9 immediately after its formation. Therefore, when the light-transmitting functional layer 9 contains a mixture of fillers and resin, the change in the optical properties of the light-transmitting functional layer 9 caused by the above-mentioned processes is particularly small.

[0078] The aforementioned optical device OD is an organic EL-type microdisplay, but the technology described herein can be applied to other optical devices and their manufacturing. For example, the optical device can also be a miniature LED display that includes a light-emitting diode as an optical element, or a camera device that includes a light-emitting diode as an optical element. [Example]

[0079] The following describes the experiments conducted in connection with the present invention.

[0080] <1> Experiment 1 (Example 1) First, prepare the structure shown in Figure 2. The light-transmitting functional layer 9 is formed by dispersing inorganic fillers in a resin. The resin used is acrylic resin. The inorganic filler consists of amorphous spherical particles containing silica with an average particle size of 12 nm. The filler accounts for 40% by mass of the light-transmitting functional layer 9. The thickness of the light-transmitting functional layer 9 is 0.2 μm.

[0081] The light-transmitting layer 10 is a resin layer made of acrylic resin with a thickness of 0.3 μm. The color filter layer 11 is formed with a thickness of 1.2 μm. The protective film layer 12 is a resin layer made of acrylic resin with a thickness of 2.0 μm.

[0082] Next, for this structure, in order to remove the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10, plasma etching using oxygen and two-liquid cleaning are performed in the following order. The plasma etching is performed for 1 minute under the conditions of antenna power of 500W and bias power of 50W. The two-liquid cleaning is performed for 30 seconds.

[0083] A single cycle involving plasma etching and two-component cleaning is insufficient to remove all the layers, so this cycle is performed twice in total. As a result, the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10 can be removed without residue, yielding the recycled product shown in Figure 4. Furthermore, there was no peeling of the layers contained in the recycled product, or deterioration or damage to the light-transmitting functional layer 9 and the inorganic sealing layer 8, which occurred during this process.

[0084] (Example 2) First, prepare the structure shown in Figure 2. The structure and composition of this structure are assumed to be the same as the structure prepared in Example 1.

[0085] Next, for this structure, in order to remove the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10, plasma etching using oxygen and two-liquid cleaning are performed in the following order. The plasma etching is performed for 1 minute under the conditions of antenna power of 500W and bias power of 25W. The two-liquid cleaning is performed for 30 seconds. The cycle including plasma etching and two-liquid cleaning is performed a total of 3 times.

[0086] As a result, the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10 can be removed without residue, yielding the recycled product shown in Figure 4. Furthermore, there was no peeling of the layers contained in the recycled product, or deterioration or damage to the light-transmitting functional layer 9 and the inorganic sealing layer 8, which occurred as a result of this treatment.

[0087] (Example 3) First, prepare the structure shown in Figure 2. The structure and composition of this structure are assumed to be the same as the structure prepared in Example 1.

[0088] Next, for this structure, in order to protect the film layer 12, the color filter layer 11, and the light-transmitting layer 10, plasma etching using oxygen and two-liquid cleaning are performed in the following order. The plasma etching is performed for 1.5 minutes under the conditions of antenna power of 500W and bias power of 100W. The two-liquid cleaning is performed for 30 seconds.

[0089] In this example, a small amount of residue may remain after a single plasma etching, but all residue is removed by subsequent two-liquid cleaning. Furthermore, there was no peeling of the layers contained in the recycled product, or deterioration or damage to the light-transmitting functional layer 9 and the inorganic sealing layer 8, which occurred as a result of this treatment.

[0090] (Example 4) First, prepare the structure shown in Figure 2. The structure and composition of this structure are assumed to be the same as the structure prepared in Example 1.

[0091] Next, for this structure, in order to remove the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10, plasma etching using oxygen and two-liquid cleaning are performed in the following order. The plasma etching is performed for 2 minutes under the conditions of antenna power of 250W and bias power of 50W. The two-liquid cleaning is performed for 30 seconds. The cycle including plasma etching and two-liquid cleaning is performed a total of 2 times.

[0092] As a result, the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10 can be removed without residue, yielding the recycled product shown in Figure 4. Furthermore, there is no peeling of the layers contained in the recycled product, or deterioration or damage to the light-transmitting functional layer 9 and the inorganic sealing layer 8, which occurs with this treatment.

[0093] (Comparative Example 1) First, except for omitting the light-transmitting functional layer 9, the same structure as that described with reference to Figure 2 is prepared. The structure and composition of each layer contained in this structure are assumed to be the same as the structure prepared in Example 1.

[0094] Secondly, for this structure, in order to remove the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10, plasma etching using oxygen and two-liquid cleaning are performed in the following order. The conditions for plasma etching and two-liquid cleaning are set to be the same as in Example 1.

[0095] A single cycle, including plasma etching and two-component cleaning, was insufficient to remove all residues, so the cycle was performed twice. As a result, although the residues were completely removed in the second cycle, a significant degree of damage, such as cracking, occurred in the inorganic sealing layer 8.

[0096] (Comparative Example 2) First, except for omitting the light-transmitting functional layer 9, the same structure as that described with reference to Figure 2 is prepared. The structure and composition of each layer contained in this structure are assumed to be the same as the structure prepared in Example 1.

[0097] Secondly, for this structure, in order to remove the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10, plasma etching using oxygen and two-liquid cleaning are performed in the following order. The conditions for plasma etching and two-liquid cleaning are set to be the same as in Example 2.

[0098] Two cycles, including plasma etching and two-liquid cleaning, were insufficient to remove all residues, so a total of three cycles were performed. As a result, although all residues were removed in the third cycle, damage such as cracking occurred in the inorganic sealing layer 8 to a degree that could not be ignored.

[0099] (Comparative Example 3) First, except for omitting the light-transmitting functional layer 9, the same structure as that described with reference to Figure 2 is prepared. The structure and composition of each layer contained in this structure are assumed to be the same as the structure prepared in Example 1.

[0100] Next, for this structure, in order to remove the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10, plasma etching using oxygen and two-liquid cleaning are performed in the following order. The conditions for plasma etching and two-liquid cleaning are set to be the same as in Example 3.

[0101] As a result, although all the residue was removed, the inorganic sealing layer 8 suffered damage such as cracking that could not be ignored.

[0102] (Comparative Example 4) First, except for omitting the light-transmitting functional layer 9, the same structure as that described with reference to Figure 2 is prepared. The structure and composition of each layer contained in this structure are assumed to be the same as the structure prepared in Example 1.

[0103] Secondly, for this structure, in order to remove the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10, plasma etching using oxygen and two-liquid cleaning are performed in the following order. The conditions for plasma etching and two-liquid cleaning are set to be the same as in Example 4.

[0104] A single cycle, including plasma etching and two-component cleaning, was insufficient to remove all residues, so the cycle was performed twice. As a result, although the residues were completely removed in the second cycle, a significant degree of damage, such as cracking, occurred in the inorganic sealing layer 8.

[0105] The results obtained from Examples 1 to 4 and Comparative Examples 1 to 4 are summarized in Table 1 below.

[0106] [Table 1] Translucent functional layer Antenna power (W) Bias power (W) Processing time (minute) Cycle number determination Example 1 have 500 50 1 2 A Example 2 have 500 25 1 3 A Example 3 have 500 100 1.5 1 A Example 4 have 250 50 2 2 A Comparative Example 1 none 500 50 1 2 B Comparative Example 2 none 500 25 1 3 B Comparative Example 3 none 500 100 1.5 1 B Comparative Example 4 none 250 50 2 2 B

[0107] In Table 1, "Processing Time" represents the processing time for plasma etching, and "Number of Cycles" represents the number of cycles including plasma etching and two-component cleaning. Furthermore, in Table 1, "A" indicates that the protective film layer 12 and the color filter layer 11 can be removed without residue, and there is no peeling of the layers contained in the recycled product, or deterioration or damage to the light-transmitting functional layer 9 and the inorganic sealing layer 8. Moreover, in Table 1, "B" indicates damage such as cracking to a degree that cannot be ignored in the inorganic sealing layer 8.

[0108] As shown in Comparative Examples 1 to 4 in Table 1, when the transparent functional layer 9 is omitted, damage such as cracking occurs in the inorganic sealing layer 8 to a considerable degree, regardless of changes in antenna power, bias power, processing time, and number of cycles. In contrast, as shown in Examples 1 to 4 in Table 1, when the transparent functional layer 9 is provided, even with different antenna power, bias power, and processing time, the protective film layer 12, color filter layer 11, and transparent layer 10 can be removed without residue by appropriately setting the number of cycles. Furthermore, it prevents the peeling of layers contained in the recycled product, or the deterioration or damage of the transparent functional layer 9 and the inorganic sealing layer 8.

[0109] <2> Experiment 2 (Example 5) First, prepare the structure shown in Figure 2. However, in this example, in order to make it easy to confirm the protective ability of the light-transmitting functional layer 9, the colored resin layer is placed between the inorganic sealing layer 8 and the light-transmitting functional layer 9.

[0110] The light-transmitting functional layer 9 is formed by dispersing inorganic fillers in a resin. The resin used is acrylic resin. The inorganic filler consists of amorphous spherical particles containing silica with an average particle size of 12 nm. The filler constitutes 5% by mass of the light-transmitting functional layer 9. The thickness of the light-transmitting functional layer 9 is 0.2 μm.

[0111] The light-transmitting layer 10 is a resin layer made of acrylic resin with a thickness of 0.2 μm. The color filter layer 11 is formed with a thickness of 1.2 μm. The protective film layer 12 is a resin layer made of acrylic resin with a thickness of 2.0 μm.

[0112] Next, for the above structure, in order to remove the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10, plasma etching using oxygen and two-liquid cleaning were performed in the following order. The plasma etching was performed for 1 minute under conditions of 500W antenna power and 50W bias power. The two-liquid cleaning was performed for 30 seconds. The cycle including plasma etching and two-liquid cleaning was performed a total of 2 times. By performing the above steps, the recycled product shown in Figure 4 was obtained.

[0113] The recycled product was then observed using an optical microscope. The results showed that the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10 were removed without residue. Furthermore, while some damage occurred to the colored resin layer, no serious deterioration or breakage occurred in the inorganic sealing layer 8.

[0114] Furthermore, the hardness of the light-transmitting functional layer 9 was investigated using the following method. First, a sample was prepared by forming a layer with the same composition as the aforementioned light-transmitting functional layer 9 at a thickness of 3.0 μm on a glass substrate with a thickness of 0.7 mm. Next, the Vickers hardness of this sample was measured. The Vickers hardness was measured using a FISCHERSCOPE (registered trademark) HM-2000 manufactured by Helmut Fischer. During the measurement, the loading speed was set to 0.4 mN / s, and the indenter was pressed into the aforementioned layer to a maximum load of 2 mN, held at this state for 10 seconds, and then the indenter was pulled out under the same conditions as when it was pressed. The change in substrate distortion during this process was used to determine the nano-indentation hardness, which was then converted to Vickers hardness. The result was a Vickers hardness of 41.2 kgf / mm².

[0115] (Example 6) Except that the proportion of filler in the light-transmitting functional layer 9 was set to 10% by mass, the same test as in Example 5 was conducted.

[0116] The recycled product was then observed using an optical microscope. The results showed that the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10 were removed without residue. Furthermore, while some damage occurred to the colored resin layer, no serious deterioration or breakage occurred in the inorganic sealing layer 8.

[0117] Furthermore, in this example, the hardness of the translucent functional layer 9 was investigated using the same method as in Example 5. The result showed a Vickers hardness of 40.8 kgf / mm².

[0118] (Example 7) Except that the proportion of filler in the light-transmitting functional layer 9 was set to 20% by mass, the same test as in Example 5 was conducted.

[0119] The recycled product was then observed using an optical microscope. The results showed that the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10 were removed without residue. Furthermore, while some damage occurred to the colored resin layer, no serious deterioration or breakage occurred in the inorganic sealing layer 8.

[0120] Furthermore, in this example, the hardness of the translucent functional layer 9 was investigated using the same method as in Example 5. The result showed a Vickers hardness of 44.2 kgf / mm².

[0121] (Example 8) Except that the proportion of filler in the light-transmitting functional layer 9 was set to 30% by mass, the same test as in Example 5 was performed. In this example, the Vickers hardness of the light-transmitting functional layer 9 was 49.7 kgf / mm².

[0122] The recycled product was then observed using an optical microscope. The results showed that the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10 were removed without residue. Furthermore, no damage was found to the coloring resin layer.

[0123] (Example 9) Except that the proportion of filler in the light-transmitting functional layer 9 was set to 40% by mass, the same test as in Example 5 was conducted.

[0124] The recycled product was then observed using an optical microscope. The results showed that the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10 were removed without residue. Furthermore, no damage was found to the coloring resin layer.

[0125] Furthermore, in this example, the hardness of the translucent functional layer 9 was investigated using the same method as in Example 5. The result showed a Vickers hardness of 59.5 kgf / mm².

[0126] (Example 10) Except that the proportion of filler in the light-transmitting functional layer 9 was set to 50% by mass, the same test as in Example 5 was conducted.

[0127] The recycled product was then observed using an optical microscope. The results showed that the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10 were removed without residue. Furthermore, no damage was found to the coloring resin layer.

[0128] Furthermore, in this example, the hardness of the translucent functional layer 9 was investigated using the same method as in Example 5. The result showed a Vickers hardness of 69.5 kgf / mm².

[0129] (Comparative Example 5) Except for replacing the light-transmitting functional layer 9 with a resin layer, the same test as in Example 5 was conducted. As for the resin layer, it was formed by using the resin used in the formation of the light-transmitting functional layer 9 in Example 5, and had the same thickness as the light-transmitting functional layer 9 in Example 5.

[0130] The recycled product was then observed using an optical microscope. The results showed that the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10 were removed without residue. However, the coloring resin layer was significantly damaged.

[0131] Furthermore, except for the sample used below, the hardness of the resin layer was investigated using the same method as in Example 5. That is, in this example, a sample was used, which was formed on a glass substrate with a thickness of 0.7 mm with a layer of the same composition as the resin layer described above, at a thickness of 3.0 μm. As a result, the Vickers hardness was 41.5 kgf / mm².

[0132] The results obtained from Examples 5 to 10 and Comparative Example 5 are summarized in Table 2 below.

[0133] [Table 2] Translucent functional layer packing amount (quality%) Vickers hardness (kgf / mm²) determination Example 5 have 5 41.2 A Example 6 have 10 40.8 A Example 7 have 20 44.2 A Example 8 have 30 49.7 AA Example 9 have 40 59.5 AA Example 10 have 50 69.5 AA Comparative Example 5 none 0 41.5 B

[0134] In Table 2, "filler quantity" indicates the proportion of filler in the light-transmitting functional layer 9. Furthermore, "AA" indicates that the protective film layer 12, color filter layer 11, and light-transmitting layer 10 can be removed without residue, and no damage occurs to the colored resin layer. "A" indicates that the protective film layer 12 and color filter layer 11 are removed without residue, but damage occurs to the colored resin layer to a degree not as severe as that causing serious deterioration or breakage in the inorganic sealing layer 8. Moreover, "B" indicates significant damage to the colored resin layer.

[0135] As shown in Comparative Example 5 of Table 2, when a resin layer containing resin is used to replace the light-transmitting functional layer 9, significant damage occurs to the colored resin layer. In contrast, as shown in Examples 5 to 10 of Table 2, when a resin layer light-transmitting functional layer 9 is used, the protective film layer 12, the color filter layer 11, and the light-transmitting layer 10 can be removed without residue, and no damage occurs to the colored resin layer, or even if damage occurs to the colored resin layer, it is not to the extent that severe deterioration or breakage occurs in the inorganic sealing layer 8.

[0136] 1: Silicon substrate 2: Array section 3: Array substrate 4: Adjoining layer 5: Cathode 6: Organic light-emitting layer 7: Anode 8: Inorganic sealing layer 9: Translucent Functional Layer 10: Translucent layer 11: Color Filter Layer 11A: First shaded part 11B: Second Colored Section 11C: Third shaded part 12: Protective film layer 13: Close-fitting layer 14: Protective Glass 16: Insulation layer 100:Substrate OD: Optical Device

Claims

1. An optical device comprising: a silicon substrate having a plurality of optical elements disposed on a main surface of one side; an inorganic sealing layer disposed on the main surface; a color filter layer disposed on the inorganic sealing layer; and a light-transmitting functional layer disposed between the inorganic sealing layer and the color filter layer, comprising at least one of an inorganic material and a silicone resin, the light-transmitting functional layer further comprising a resin, and comprising at least one of the inorganic material and the silicone resin as a filler dispersed in the resin.

2. The optical device of claim 1, wherein the filler comprises in the light-transmitting functional layer in the range of 5% by mass to 90% by mass.

3. The optical device of claim 1, wherein the resin is an acrylic resin.

4. An optical device comprising: a silicon substrate having a plurality of optical elements disposed on a main surface of one side; an inorganic sealing layer disposed on the main surface; a color filter layer disposed on the inorganic sealing layer; and a light-transmitting functional layer disposed between the inorganic sealing layer and the color filter layer, comprising at least one of an inorganic material and a silicone resin, wherein the light-transmitting functional layer has a Vickers hardness of 45 kgf / mm² or higher.

5. An optical device as claimed in any one of claims 1 to 4, wherein the light-transmitting functional layer comprises an inorganic oxide as the inorganic material.

6. The optical device of any one of claims 1 to 4, wherein the light-transmitting functional layer comprises silica.

7. The optical device of any one of claims 1 to 4, wherein the thickness of the light-transmitting functional layer is in the range of 0.1 μm to 5.0 μm.

8. The optical device according to any one of claims 1 to 4, further comprising: a light-transmitting layer containing an organic material, located between the light-transmitting functional layer and the color filter layer.

9. An optical device as claimed in any of claims 1 to 4, wherein each of the plurality of optical elements is an organic electroluminescent element.

10. A method for manufacturing an optical device, comprising: preparing a structure having a silicon substrate having a plurality of optical elements disposed on a main surface of one side, and an inorganic sealing layer disposed on the main surface; forming a light-transmitting functional layer comprising at least one of an inorganic material and a silicone resin on the inorganic sealing layer to obtain a first product; forming a color filter layer on the light-transmitting functional layer to obtain a second product; inspecting the color filter layer for defects, selecting products with defects in the color filter layer from the second product as products requiring repair; and removing the color filter layer from the products requiring repair to obtain a recycled product having the same structure as the first product.

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