JP6606874B2 - Optical member and optical member manufacturing method - Google Patents

Description

  The present invention provides a front surface of a display device such as a transmissive liquid crystal display (LCD) or an organic EL (Electro Luminescence) display, which is equipped with a backlight device having a light emitting diode (LED) as a light source. The present invention relates to an optical member such as glass used in the above and a light transmission window of a solid-state imaging device.

  In a transmissive liquid crystal display, a backlight is disposed on the back side, and an image is displayed by illuminating the back surface of the liquid crystal display with the backlight. Moreover, in an organic EL display, an image is displayed using a self-luminous element.

  In these display devices, a light-shielding film is provided on the peripheral edge of the display device in order to prevent leakage of illumination light or the like from the periphery of the display device (see, for example, Patent Document 1).

  In addition, many mobile phone devices include a solid-state imaging device (digital still camera) on the back side of the display device. The solid-state imaging device has a circular transparent window on the outermost surface of the device so that a solid-state imaging device (typically, CMOS or CCD) provided inside the device can receive light, and the periphery of the transparent window is unnecessary. A light-shielding film is provided so that no light enters.

JP 2008-145655 A

  The light shielding film around the light transmission window of the solid-state imaging device described above may be provided on the subject side. When the light shielding film is provided on the subject side, the light shielding film may be located on the outermost surface side of the solid-state imaging device, and there is a concern that the light shielding film may be peeled off due to contact with other objects when the device is used. Further, even when the light shielding film is provided on the solid-state imaging device side of the light transmission window, when another functional film is formed on the light shielding film, the light shielding film is caused by the film stress of the functional film. There is a concern about the peeling. The concern about peeling of the light shielding film may occur in the display device as well.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical member in which the light shielding film is not easily peeled in an optical member provided with a light shielding film, and a method for manufacturing the optical member.

  As a result of intensive studies, the present inventors have found that an optical member in which the light shielding film is difficult to peel off can be obtained by providing a thin film portion on the opening side of the light shielding film.

That is, the optical member of the present invention is an optical device including a base material that transmits light having a wavelength in the visible region, a light shielding film provided on the surface of the base material, and an opening in which a part of the light shielding film is missing. The light-shielding film includes a thin film portion on the opening side, and the thin film portion has an average physical film thickness of 50 nm or less and a width of 1 μm or more .

  In the optical member of the present invention, the light shielding film has a maximum reflectance of 20% or less of light having a wavelength of 380 nm to 780 nm measured from the side of the substrate on which the light shielding film is not formed. Is preferred.

  In the optical member of the present invention, the light-shielding film has a three-layer structure in which a metal nitride film, a metal film, and a metal nitride film are sequentially formed from the base material side, or a metal oxide film from the base material side Any of a three-layer structure in which a metal film and a metal oxide film are sequentially formed, or a three-layer structure in which a metal oxynitride film, a metal film, and a metal oxynitride film are sequentially formed from the substrate side It is preferable to have. In the light-shielding film, the metal, metal nitride, metal oxide, or metal oxynitride that constitutes each of the three-layered films is preferably chromium.

In the optical element of the present invention, the light-shielding film, the difference in average thermal expansion coefficient between the base material (the temperature range of 0 to 300 ° C.) is preferably at 100 × 10 -7 ^/ ℃ or less.

  Moreover, the optical member of this invention WHEREIN: The said light shielding film may be provided with the transition area | region part from which a film thickness reduces gradually in the boundary with the said opening part.

  The method for producing an optical member of the present invention includes a step of forming an adhesive layer on a substrate that transmits light having a wavelength in the visible region, and a mask layer having the same or larger size as the adhesive layer is formed on the adhesive layer. A step of forming a light-shielding film on a substrate on which the adhesive layer and the mask layer are disposed, and a step of removing the adhesive layer and the mask layer to form an opening. To do.

  In the method for producing an optical member of the present invention, it is preferable that a distance from the outer periphery of the mask layer to the outer periphery of the adhesive layer is 25 to 250 μm.

  According to the present invention, an optical member in which the light shielding film is hardly peeled off can be obtained.

It is sectional drawing which shows schematically the structure of the optical member of the 1st Embodiment of this invention. It is sectional drawing which shows schematically the structure of the optical member which is not provided with a thin film part. It is sectional drawing which shows schematically the structure of the optical member of the 2nd Embodiment of this invention. It is a flowchart for demonstrating the manufacturing method of the optical member of this invention. It is sectional drawing in order to demonstrate the manufacturing method of the optical member of this invention. In the optical member (Example 1) of this invention, it is an electron micrograph which shows the cross section before peeling an adhesion layer and a mask layer. It is a graph which shows the reflectance measured from the light shielding film formation surface (film-forming surface) and the opposite surface (substrate surface) of the optical member (Example 1) of this invention. It is an electron micrograph of the cross section of the optical member (Example 1) of this invention. It is an electron micrograph of the cross section of the optical member (Example 2) of this invention. It is a graph which shows the film thickness of the light shielding film of the optical member (Example 2) of this invention.

  Hereinafter, preferred embodiments of the optical member according to the present invention will be described. In addition, the optical member which concerns on each following embodiment is a typical illustration, Comprising: This invention is not limited to these.

[First Embodiment]
FIG. 1 is a cross-sectional view schematically showing the configuration of the optical member according to the first embodiment of the present invention.

  As shown in FIG. 1, the optical member 1 of the first embodiment includes a base material 11 and a light shielding film 12 provided on the surface of the base material 11. The light shielding film 12 is provided on the surface of the base material 11 other than the opening 15, and is continuously provided at the boundary with the opening 15 from the main body of the light shielding film 12 (other than the boundary with the opening 15). The thin film portion 13 and the transition region portion 14 where the physical film thickness gradually decreases toward the opening 15 are included.

The base material 11 transmits light having a wavelength in the visible region, and is made of glass or resin. As the glass, those having an appropriate composition such as soda lime glass, borosilicate glass, aluminosilicate glass, alkali-free glass, fluorophosphate glass, phosphate glass, and transparent crystallized glass can be used. In applications where the optical member 1 is used, when high strength is required, tempered glass obtained by subjecting glass to tempering treatment (physical tempering treatment or chemical tempering treatment) may be used. As the resin, an appropriate one such as polycarbonate, acrylic resin, PET (polyethylene terephthalate) resin, COP (cycloolefin polymer) resin, or the like can be used.
Moreover, although the base material 11 is typically plate-shaped, a curved surface shape or a surface may be provided with unevenness.

  The light shielding film 12 is provided on the surface of the substrate 11. When the base material 11 is plate-shaped, for example, the light shielding film 12 is provided on one surface (main surface) or both surfaces. The opening 15 is a part of the light-shielding film 12 that is lost, and thereby transmits light having a wavelength in the visible region. The light shielding film 12 and the opening 15 are provided on the same surface of the substrate 11.

  The light-shielding film 12 is a layer that suppresses transmission of visible light at a portion where the light-shielding film 12 is formed. Therefore, the light-shielding film 12 preferably has an average transmittance of light having a wavelength of 380 nm to 780 nm of 5% or less, and more preferably 1% or less. Note that the transmittance of the light shielding film 12 refers to a linear transmittance measured from the side of the substrate 11 on which the light shielding film 12 is formed.

  When the optical member 1 is used on the outermost surface of the apparatus, the light shielding film 12 is preferably so-called jet black that does not exhibit a specific color. Therefore, the light-shielding film 12 preferably has a maximum reflectance of light having a wavelength of 380 nm to 780 nm measured from the side of the substrate 11 where the light-shielding film 12 is not formed, being 20% or less, and preferably 10% or less. More preferably.

  The light shielding film 12 has a three-layer structure (hereinafter referred to as a first structure) in which a metal nitride film, a metal film, and a metal nitride film are formed in this order from the substrate 11 side, or a metal from the substrate 11 side. A three-layer structure in which an oxide film, a metal film, and a metal oxide film are formed in this order (hereinafter referred to as a second structure), or a metal oxynitride film, a metal film, and a metal oxynitride from the substrate side It is preferable that the film has any of a three-layer structure (hereinafter referred to as a third structure) formed in this order. Further, in the metal, metal nitride, metal oxide, and metal oxynitride that are the materials constituting each film of these three-layer structures, the metal is preferably chromium. That is, the first structure is a three-layer structure in which a chromium nitride film, a chromium film, and a chromium nitride film are sequentially formed, and the second structure is formed by sequentially forming a chromium oxide film, a chromium film, and a chromium oxide film. It is a three-layer structure, and the third structure is preferably a three-layer structure in which a chromium oxynitride film, a chromium film, and a chromium oxynitride film are sequentially formed. By setting it as such a film structure, the light shielding film 12 with a thin physical film thickness and high visible light shielding property can be obtained.

  As a method for forming the light shielding film 12, a known film forming method such as a heat evaporation method, a sputtering method, or an ion assist evaporation method can be used. A preferred method for forming the light shielding film 12 will be described later.

The light shielding film 12 includes a thin film portion 13 having an average physical film thickness of 50 nm or less and a width of 1 μm or more on the side of the opening 15 where a part of the light shielding film 12 is missing. Here, the physical film thickness changes abruptly at the boundary between the light shielding film 12 and the opening 15 (for example, as shown in FIG. 2, the shape of the light shielding film 12 stands perpendicular to the base material 11). If the light shielding film 12 receives an external force when the optical member 1 is used, the light shielding film 12 may be peeled off from the boundary portion with the opening 15.
On the other hand, by providing the thin film portion 13 continuous with the main body portion of the light shielding film 12 on the opening 15 side, the contact area between the light shielding film 12 and the base material 11 is increased, and stress is generated in the light shielding film 12. Even in this case, the light shielding film 12 can be prevented from being peeled off from the boundary portion with the opening 15.

  The thin film portion 13 is located at a boundary portion between the light shielding film 12 and the opening 15. Since the thin film portion 13 has an average physical film thickness of 50 nm or less, the transmittance of the film itself is high, and the transmittance of visible light in the opening 15 is not greatly reduced. The physical film thickness of the thin film portion 13 is preferably 50 nm or less, and more preferably 20 nm or less. Moreover, since the thin film portion 13 has a width of 1 μm or more and a certain amount of area that is in close contact with the base material 11 is ensured, peeling from the base material 11 can be suppressed. Peeling of the light shielding film 12 (main body part) from the base material 11 can be suppressed. The width of the thin film portion 13 is preferably 20 μm or less, and more preferably 10 μm or less. Moreover, it is preferable that it is 3 micrometers or more.

  The light shielding film 12 may include a transition region portion 14 in which the film thickness gradually decreases at the boundary with the opening 15. The transition region portion 14 is a boundary portion between the light shielding film 12 and the opening 15 and a portion where the film thickness other than the thin film portion 13 gradually decreases. If the light shielding film 12 does not include the transition region portion 14 at the boundary with the opening 15, side lobes may occur in an image formed by light transmitted through the opening 15 due to diffraction. The side lobe is a phenomenon in which the density on the concentric circle is recognized in the transmitted image when the opening 15 is a circular through hole. By providing the transition region portion 14, side lobes can be suppressed.

The light-shielding film 12 preferably has a difference in average thermal expansion coefficient (temperature range of 0 to 300 ° C.) from the base material 11 of 100 × 10 ⁻⁷ / ° C. or less. When the difference in average thermal expansion coefficient between the light shielding film 12 and the base material 11 exceeds 100 × 10 ⁻⁷ / ° C., the optical member 1 is shielded from light due to the difference in thermal expansion coefficient when exposed to a high temperature. Stress may be generated at the interface between the film 12 and the substrate 11, and the light shielding film 12 may be peeled off from the substrate 11. Even if the optical member 1 is exposed to a high temperature in the manufacturing process by setting the difference in average thermal expansion coefficient from the base material 11 to 100 × 10 ⁻⁷ / ° C. or less, the light shielding film 12 is a base material. It is possible to prevent the light shielding film 12 from being peeled off from 11. The difference in average thermal expansion coefficient between the light shielding film 12 and the substrate 11 is more preferably 50 × 10 ⁻⁷ / ° C. or less.

[Second Embodiment]
An optical member 2 according to a second embodiment of the present invention will be described with reference to FIG.
FIG. 3 is a cross-sectional view schematically showing the configuration of the optical member 2 according to the second embodiment of the present invention. In addition, this embodiment is a modification of 1st Embodiment, Comprising: The same code | symbol is attached | subjected to the same part or similar part as 1st Embodiment, and duplication description is abbreviate | omitted.

  The second embodiment is different from the first embodiment in that the light shielding film 12 does not include a transition region portion. Also in this embodiment, since the light shielding film 12 includes the thin film portion 13 on the opening 15 side, even if an external force is applied to the light shielding film 12, the light shielding film 12 can be prevented from peeling off from the base material 11. .

  Next, the manufacturing method of the optical member of this invention is demonstrated.

  As shown in FIG. 4, the method for producing an optical member of the present invention includes a step of forming an adhesive layer for forming an opening on a substrate, a step of forming a mask layer on the adhesive layer, A step of forming a light-shielding film including a thin film portion on a substrate on which the layer and the mask layer are disposed, and a step of removing the adhesive layer and the mask layer. By this manufacturing method, an optical member in which the light shielding film is hardly peeled off from the substrate can be obtained.

  In the step of creating the adhesive layer for forming the opening, as shown in FIG. 5A, an adhesive layer 21 having substantially the same shape as the desired opening is formed on the surface of the base material 11. As the adhesive layer 21, a known material can be used as long as adhesion with the substrate 11 is obtained. Further, the pressure-sensitive adhesive layer 21 may be affixed by punching a pressure-sensitive adhesive sheet into a desired shape, or a plurality of adhesives may be applied by applying the pressure-sensitive adhesive on the substrate 11 using a printing means, and then solidifying. The adhesive layer 21 may be provided simultaneously. As a material constituting the adhesive layer 21, silicone, acrylic resin, or the like can be used. The thickness of the adhesive layer 21 is appropriately adjusted according to the thickness of the light shielding film. The pressure-sensitive adhesive layer 21 created in a predetermined shape may be attached to the base material 11 alone, or may be attached to the base material 11 after being integrated with a mask layer described later.

  In the step of forming the mask layer, as shown in FIG. 5B, a mask layer 22 having the same size as or larger than the pressure-sensitive adhesive layer 21 is formed on the pressure-sensitive adhesive layer 21. This step includes a step of creating a mask layer 22 having a desired shape and size and integrating it with the adhesive layer 21. When the mask layer 22 having the same size as the adhesive layer 21 is provided on the adhesive layer 21, the outer periphery of the adhesive layer 21 is turned up as shown in FIG. A space 23 is formed between the two. When a mask layer 22 having a size larger than that of the adhesive layer 21 is provided on the adhesive layer 21, as shown in FIG. 5B, a part (outer peripheral portion) of the mask layer 22 is an adhesive layer. Accordingly, a space 23 without the adhesive layer 21 is formed between the mask layer 22 and the substrate 11.

  As the mask layer 22, a sheet-like resin, metal, or the like can be used. Moreover, it is preferable that the mask layer 22 is a layer in which the portion protruding from the adhesive layer 21 is not deformed in the next step of forming the light shielding film 12. The mask layer 22 formed in a predetermined shape may be affixed on the adhesive layer 21 provided on the substrate 11, and as described above, the mask layer 22 and the adhesive layer 21 are integrated. You may affix on the base material 11. FIG.

  The distance from the outer periphery of the mask layer 22 to the outer periphery of the adhesive layer 21 (the outer periphery of the mask layer 22) in the space 23 without the adhesive layer 21 formed when the mask layer 22 having a size larger than the adhesive layer 21 is provided. Part of the part from the adhesive layer 21) is preferably 25 to 250 μm. If this distance is less than 25 μm, the area of the thin film portion obtained in the next step of forming the light shielding film is small, and the effect of suppressing peeling of the light shielding film is small. In addition, when the distance is more than 250 μm, the area of the obtained thin film portion is large and the effect of suppressing the peeling of the light shielding film is great, but the portion protruding from the adhesive layer 21 of the mask layer 22 forms the light shielding film. There is a possibility that the desired thin film portion cannot be obtained. As for the distance from the outer periphery of the mask layer 22 to the outer periphery of the adhesion layer 21, it is more preferable that it is 30-200 micrometers.

  Next, in the step of forming the light-shielding film, as shown in FIG. 5C, on the base material 11 on which the adhesive layer 21 and the mask layer 22 are formed, a heating vapor deposition method, a sputtering method, an ion-assisted vapor deposition method, etc. The light shielding film 12 is formed using a known film forming method. In this step, the film substance constituting the light-shielding film 12 also enters the space 23 where the adhesive layer 21 between the mask layer 22 and the substrate 11 is not present. Therefore, the thin film portion 13 having a very thin physical film thickness is formed on the base material 11 immediately below the space 23 where the adhesive layer 21 between the mask layer 22 and the base material 11 is not present, as compared with the portion where the mask layer 22 is not provided. The light shielding film 12 is formed continuously. Since the thin film portion 13 has a very thin physical film thickness, it has a limited influence on the transmission of visible light through the opening, and can prevent the light shielding film 12 from peeling off.

  Next, in the step of removing the adhesive layer 21 and the mask layer 22, the adhesive layer 21 and the mask layer 22 are removed from the base material 11 on which the light shielding film 12 is formed, and the optical member 1 shown in FIG. 5 (d) is obtained. . In this way, the optical member 1 in which peeling of the light shielding film 12 is suppressed can be obtained.

  The optical member of the present invention can be suitably used as a cover member on the subject side of a solid-state imaging device. Such a cover member is used by being fitted into a part of a casing of a portable electronic device. Examples of portable electronic devices include mobile phones, PHS (Personal Handy-phone System), smartphones, PDAs (Personal Data Assistance), PNDs (Portable Navigation Device, portable car navigation systems), and the like.

  Moreover, the optical member of this invention can also be used as a front member of the display apparatus of the apparatus with a display apparatus. As a device with a display device, in addition to the above-mentioned portable electronic device, portable radio, portable TV, one-segment receiver, digital camera, video camera, portable music player, sound recorder, portable DVD player, portable game machine, laptop computer, Examples include a tablet PC, an electronic dictionary, an electronic notebook, an electronic book reader, a portable printer, and a portable scanner. Further, it can be used for stationary electronic devices and electronic devices installed in automobiles. Note that the device with a display device is not limited to these exemplary devices.

  Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. The configuration can be changed as appropriate within the limits not departing from the spirit of the present invention.

  Hereinafter, the present invention will be described based on examples.

Example 1
First, a glass substrate (soda lime glass, plate thickness: 5 mm) was prepared. A circular mask seal (adhesive) comprising a PET film (mask layer, diameter: 5 mm, thickness: 0.1 mm) and an adhesive (adhesive layer, diameter: 5 mm, thickness: 0.03 mm) on this glass substrate. A mask sticker is attached.
Next, chromium oxynitride (45 nm), chromium (130 nm), and chromium oxynitride (55 nm) are formed in this order from the glass substrate side on which the mask seal is affixed to the thickness shown in parentheses by sputtering. A film was formed. When the cross section of the glass substrate on which the light-shielding film was thus formed was observed with an electron microscope, a space 23 having a height of 16 μm and a width of 66 μm was formed under the adhesive layer 21 as shown in FIG. In FIG. 6, reference numeral 11 denotes a base material (glass substrate), reference numeral 12 denotes a light shielding film, and reference numeral 22 denotes a mask layer.

  Next, the mask seal was removed from the glass substrate. Then, the reflectance was measured from the light shielding film forming surface (also referred to as a film forming surface) and the surface opposite to the light shielding film forming surface (also referred to as the substrate surface) of the glass substrate. The measurement results are shown in FIG. Further, when the cross section of the light shielding film on the glass substrate was observed with an electron microscope, a transition region portion 14 and a thin film portion 13 having a width of 1 μm or more were observed as shown in FIG.

(Example 2)
A glass substrate (manufactured by Asahi Glass Co., Ltd., trade name: EN-A1, plate thickness: 0.2 mm) was prepared. On this glass substrate, a resin body in which a mask layer and an adhesive layer were integrated was formed.
Next, the mask layer and the adhesive layer are formed from the glass substrate side in the order of chromium oxynitride (45 nm), chromium (130 nm) and chromium oxynitride (55 nm) in the order shown in parentheses by sputtering. A light shielding film was formed on the glass substrate.

Next, the adhesive layer and the mask layer were removed from the glass substrate.
Next, when the cross section of the light shielding film on the glass substrate was observed with an electron microscope, a transition region portion 14 and a thin film portion 13 having a width of 1 μm or more were observed as shown in FIG. Moreover, when the film thickness of the light shielding film was calculated | required from this electron micrograph, the graph shown in FIG. 10 was obtained. The width of the thin film portion obtained from the graph of FIG. 10 was 3 μm or more.

Next, the film | membrane adhesiveness of the glass substrate with a light shielding film obtained in Example 1 and Example 2 was evaluated with the following method.
<Light-shielding film adhesion test>
An adhesive tape (adhesive tape with a width of 18 mm defined in JIS Z1522) is attached to the surface of the glass substrate on which the light-shielding film is formed so as to include an opening. Pulled strongly in the vertical direction and peeled off instantaneously. And the presence or absence of peeling of the light shielding film was confirmed.

About the glass substrate with a light shielding film obtained in Example 1 and Example 2, the film adhesion test was performed, but peeling of the light shielding film was not observed.
From these evaluation results, it can be seen that the light-shielding films of Examples 1 and 2 have high film adhesion to the glass substrate, and film peeling hardly occurs at the boundary with the opening.

  According to the present invention, an optical member in which the light shielding film is hardly peeled off can be obtained.

  DESCRIPTION OF SYMBOLS 1, 2 ... Optical member, 11 ... Base material, 12 ... Light-shielding film, 13 ... Thin film part, 14 ... Transition area part, 15 ... Opening part, 21 ... Adhesive layer, 22 ... Mask layer, 23 ... Space.

Claims (7)

A base material that transmits light having a wavelength in the visible region;
A light-shielding film provided on the surface of the substrate;
An optical member having an opening in which a part of the light shielding film is missing,
The light shielding film includes a thin film portion on the opening side,
The thin film portion has an average physical thickness is at 50nm or less, and Ri der is 1μm or more widths,
The light shielding film has a three-layer structure in which a metal nitride film, a metal film, and a metal nitride film are sequentially formed from the base material side, or a metal oxide film, a metal film, and a metal oxide film from the base material side. 3-layer structure was formed in this order or a metal oxynitride film from the substrate side, a metal film, a metal oxynitride film is characterized Rukoto to have a structure of any of three-layer structure formed in this order Optical member.   2. The optical member according to claim 1, wherein the light shielding film has a maximum reflectance of 20% or less of light having a wavelength of 380 nm to 780 nm measured from a side of the base material on which the light shielding film is not formed. The light-shielding film, each film metal constituting the metal nitride of the three-layer structure, metal oxides, metal is chromium in the metal oxynitride, the optical member according to claim 1 or 2. The light-shielding film, the difference in average thermal expansion coefficient between the base material (the temperature range of 0 to 300 ° C.) is a 100 × 10 -7 ^/ ℃ below, according to any one of claims 1 to 3 Optical member. The light shielding film is provided with a transition region portion where the film thickness is gradually decreased at the boundary between the opening portion, the optical member according to any one of claims 1 to 4. Forming an adhesive layer on a substrate that transmits light in the visible wavelength range;
Forming a mask layer having the same or larger size as the adhesive layer on the adhesive layer;
Forming a light shielding film on a substrate on which the adhesive layer and the mask layer are disposed;
A method for producing an optical member, comprising: removing the adhesive layer and the mask layer and forming an opening. The manufacturing method of the optical member of Claim 6 whose distance from the outer periphery of the said mask layer to the outer periphery of the said adhesion layer is 25-250 micrometers.

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