KR20180132597A - IR absorptive glass plate, manufacturing method thereof, and solid-state image pickup device - Google Patents

Abstract

Provided is an infrared absorbing glass plate capable of reducing the size of a solid-state imaging device. An infrared absorbing glass plate 1 having first and second main faces 1a and 1b facing each other and a side face 1c connecting the first and second main faces 1a and 1b, , And the thickness is 0.2 mm or less and microcracks do not exist on the side surface (1c).

Description

IR absorptive glass plate, manufacturing method thereof, and solid-state image pickup device

The present invention relates to an infrared ray absorbing glass plate, a manufacturing method thereof, and a solid-state image sensor device using the infrared ray absorbing glass plate.

In digital cameras and the like, solid-state imaging devices such as CCDs and CMOSs are used. Since these solid-state imaging device devices have a wide range of light receiving sensitivity, it is necessary to remove the light in the infrared region in order to match with the human feeling. The following Patent Document 1 discloses an infrared ray absorbing glass plate made of a fluorophosphate-based glass as a near-infrared ray cut filter for removing light in an infrared region. In Patent Document 1, the thickness of the glass plate is reduced by physical polishing using a double-side polishing machine.

Japanese Patent Application Laid-Open No. 2010-168262

In recent years, further miniaturization of solid-state imaging device devices is required. For this reason, the infrared absorbing glass plate constituting the solid-state imaging device device is required to be further thinned. However, in the method of thinning by physical polishing as in Patent Document 1, if the thickness of the glass plate is made too thin, cracks may occur in the glass plate. Therefore, the glass plate can not be made sufficiently thin, and the solid-state image pickup device can not be sufficiently miniaturized in some cases.

It is an object of the present invention to provide an infrared absorbing glass plate, a manufacturing method of the infrared absorbing glass plate, and a solid-state image sensing device which enable miniaturization of the solid-state imaging device device.

An infrared ray absorbing glass plate according to the present invention is an infrared ray absorbing glass plate having first and second main surfaces opposed to each other and side surfaces connecting the first and second main surfaces, 0.2 mm or less, and micro cracks do not exist on the side surface.

The infrared absorbing glass plate according to the present invention is preferably such that the phosphate glass contains 25 to 60% of P ₂ O ₅ , 2 to 19% of Al ₂ O ₃ , RO (R is at least one selected from the group consisting of Mg, Ca, 5 to 45% of at least one selected from Sr and Ba, 0 to 13% of ZnO, 8 to 20% of K ₂ O, 0 to 12% of Na ₂ O and 0.3 to 20% of CuO, It does not substantially contain it.

The infrared absorption glass sheet according to the present invention preferably has no abrasive marks on the first and second main surfaces.

The infrared absorption glass sheet according to the present invention preferably has an area of the first main surface of 100 mm 2 or more and 25000 mm 2 or less.

The infrared absorption glass sheet according to the present invention preferably has an area of the first main surface of not less than 1000 mm 2 and not more than 25000 mm 2.

Preferably, the infrared absorption glass sheet according to the present invention has a three-point bending strength at a distance of 2.5 mm between fulcrums of 35 N / mm 2 or more.

The infrared absorption glass sheet according to the present invention preferably has an area of the first main surface of 1 mm 2 or more and less than 1,000 mm 2.

The infrared ray absorbing glass plate according to the present invention is preferably used in a solid-state image pickup device.

The infrared absorption glass sheet according to the present invention preferably has an optical film formed on at least one of the first main surface and the second main surface.

The optical film is preferably a dielectric multilayer film.

An array of infrared absorption glass sheets according to the present invention comprises a support and a plurality of infrared absorption glass plates of the present invention arranged in a matrix on the support.

A manufacturing method of an infrared ray absorbing glass plate according to the present invention is a manufacturing method of an infrared ray absorbing glass plate constructed in accordance with the present invention which comprises a polishing step of physically polishing a plate glass base material constituted by a phosphate glass, And an etching step of etching the glass base material by immersing the glass base material in an alkaline detergent.

The infrared absorbing glass plate manufacturing method according to the present invention is preferably such that, in the polishing step, the thickness of the glass base material is set to 0.23 mm or more and 0.3 mm or less by physical polishing.

The infrared absorbing glass plate manufacturing method according to the present invention is preferably such that in the etching step, the physically polished glass base material is etched by immersing it in an alkaline detergent having a pH of 7.1 or more.

The alkali detergent preferably contains an alkali salt of an aminopolycarboxylic acid.

The method of manufacturing an infrared absorbing glass plate in which the optical film is formed further comprises a step of forming the optical film on at least one of the first main surface and the second main surface of the glass base material after etching.

The method of manufacturing an array of infrared absorbing glass plates according to the present invention comprises the steps of: fabricating the etched glass base material by the method of the present invention; placing the glass base material on the support; A step of dicing the glass base material on the supporting substrate and dividing the glass base material into the plurality of infrared absorbing glass plates arranged in a matrix form and an etching step of etching the infrared absorbing glass plate by immersing the infrared absorbing glass plate in the alkali detergent.

It is preferable that the support is a UV tape whose bonding strength is lowered by ultraviolet irradiation.

A solid-state imaging device device according to the present invention comprises an infrared ray absorbing glass plate constructed in accordance with the present invention.

According to the present invention, it is possible to provide an infrared absorbing glass plate capable of reducing the size of the solid-state imaging device device.

1 is a schematic perspective view showing an infrared ray absorbing glass plate according to an embodiment of the present invention.
2 is a schematic cross-sectional view showing a modified example of an infrared ray absorbing glass plate according to an embodiment of the present invention.
3 is a schematic sectional view showing a solid-state image pickup device using an infrared ray absorbing glass plate according to an embodiment of the present invention.
4 is a schematic cross-sectional view for explaining a manufacturing process of an infrared absorbing glass plate array according to another embodiment of the present invention.
5 is a schematic plan view for explaining a manufacturing process of an infrared absorbing glass plate array according to another embodiment of the present invention.
6 is a schematic plan view showing an array of infrared ray absorbing glass plates according to another embodiment of the present invention.

Hereinafter, preferred embodiments will be described. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. In the drawings, members having substantially the same function may be referred to by the same reference numerals.

(Infrared absorption glass plate)

1 is a schematic perspective view showing an infrared ray absorbing glass plate according to an embodiment of the present invention. As shown in Fig. 1, the infrared absorption glass sheet 1 has a square planar shape. The corners of the infrared ray absorbing glass plate 1 may be chamfered.

The infrared ray absorbing glass plate 1 has first and second main faces 1a and 1b and a side face 1c. The first and second main faces 1a and 1b face each other. In the infrared ray absorbing glass plate 1, the first and second main faces 1a and 1b are all optical surfaces. The side surface 1c connects the first and second main surfaces 1a and 1b.

The infrared ray absorbing glass plate 1 is composed of a phosphate glass containing CuO. Therefore, the infrared ray absorbing glass plate 1 is excellent in the infrared ray absorbing function.

The thickness of the infrared ray absorbing glass plate 1 is 0.2 mm or less. Preferably 0.19 mm or less, and more preferably 0.15 mm or less. Since the infrared absorbing glass plate 1 has a thickness as small as 0.2 mm or less, the solid-state imaging device device can be miniaturized when used in a solid-state imaging device device. In addition, if the thickness is too thin, the infrared absorbing glass sheet 1 may be easily cracked when it is lifted in the conveying step. Therefore, the thickness is preferably 0.05 mm or more, and more preferably 0.08 mm or more .

As described above, the infrared ray absorbing glass plate 1 is excellent in infrared ray absorbing function and can be used for a solid-state image sensor device because the solid-state image sensor device can be miniaturized.

In general, the phosphate glass tends to be cracked due to its low strength and thinness. In the present invention, since microcracks do not exist on the side surface 1c of the infrared ray absorbing glass plate 1, The cracks do not occur well. The microcrack is a crack having a length of 1 탆 to 15 탆. Micro cracks may be a starting point of cracking when the infrared absorbing glass plate 1 is bent. Particularly, when microcracks are present on the side surface 1c, it is likely to become a starting point of cracks. Therefore, when the microcracks do not exist on the side surface 1c, the infrared absorption glass sheet 1 can be prevented from cracking more easily. The presence or absence of micro cracks can be confirmed by an optical microscope.

In addition, not only the side surface 1c but also the micro cracks existing on the first and second main surfaces 1a and 1b may be a starting point of cracking. Therefore, from the viewpoint of preventing the infrared absorption glass sheet 1 from generating cracks more easily, it is preferable that the first and second main faces 1a and 1b do not have micro cracks in addition to the side face 1c desirable.

It is preferable that the first and second main faces 1a and 1b of the infrared ray absorbing glass plate 1 do not have polishing marks at the time of manufacturing. In this case, the infrared absorption glass sheet 1 can be prevented from cracking more easily. From the viewpoint of preventing the infrared absorption glass sheet 1 from generating more cracks, it is more preferable that there is no polishing marks on the side surface 1c in addition to the first and second main surfaces 1a and 1b. In addition, polishing marks can be confirmed by an atomic force microscope.

The three-point bending strength at the point-to-point distance 2.5 mm of the infrared ray absorbing glass plate 1 is preferably 35 N / mm 2 or more, and more preferably 50 N / mm 2 or more. When the three-point bending strength is equal to or more than the lower limit described above, the infrared absorption glass sheet 1 can be prevented from cracking more easily. The upper limit of the three-point bending strength of the infrared ray absorbing glass plate 1 is not particularly limited, but is about 450 N / mm 2 in terms of the material properties.

Hereinafter, the materials constituting the infrared ray absorbing glass plate 1 will be described in more detail.

Details of material;

The infrared absorbing glass plate 1 is made of a phosphate glass. It is preferable that the phosphate glass does not substantially contain F (fluorine). The term " substantially not containing " means that fluorine may be contained in an amount of 0.1% or less by mass%.

Examples of such phosphate-based glass include: 25 to 60% of P ₂ O ₅ , 2 to 19% of Al ₂ O ₃ , RO (wherein R is at least one selected from Mg, Ca, Sr and Ba, 5 to 45% of ZnO, 0 to 13% of ZnO, 8 to 20% of K ₂ O, 0 to 12% of Na ₂ O, and 0.3 to 20% of CuO, Can be used.

P ₂ O ₅ is a component forming a glass skeleton. The content of P ₂ O ₅ is preferably 25 to 60%, more preferably 30 to 55%, and still more preferably 40 to 50% in mass%. If the content of P ₂ O ₅ is too small, vitrification may become unstable. On the other hand, if the content of P ₂ O ₅ is excessively large, the weatherability tends to be lowered.

Al ₂ O ₃ is a component that further improves weather resistance. The content of Al ₂ O ₃ is preferably 2 to 19%, more preferably 2 to 15%, further preferably 2.8 to 14.5%, and particularly preferably 3.5 to 14.0% in mass% . If the content of Al ₂ O ₃ is too small, the weather resistance may not be sufficient. On the other hand, when the content of Al ₂ O ₃ is excessively large, the melting property is lowered and the melting temperature is sometimes increased. Further, when the melting temperature is elevated, Cu ions are easily reduced and are easily shifted from Cu ²⁺ to Cu ⁺ , so that desired optical characteristics may not be obtained in some cases. Specifically, there are cases where the light transmittance in the near-to-visible range is lowered or the infrared absorption property is likely to be lowered.

RO (wherein R is at least one member selected from Mg, Ca, Sr and Ba) is a component that improves weatherability and improves the meltability. The content of RO is preferably 5 to 45%, more preferably 7 to 40%, and still more preferably 10 to 35% in mass%. If the content of RO is too small, the weatherability and the melting property may not be sufficient. On the other hand, if the content of RO is too large, the stability of the glass tends to be lowered, and crystals resulting from the RO component may be easily precipitated.

The preferable range of the content of each component of RO is as follows.

MgO is a component for improving weather resistance. The content of MgO is preferably 0 to 15% by mass, more preferably 0 to 7% by mass. If the content of MgO is too large, the stability of the glass tends to be lowered.

CaO is a component that improves weatherability as well as MgO. The content of CaO is preferably 0 to 15% by mass, more preferably 0 to 7% by mass. If the content of CaO is too large, the stability of the glass tends to be lowered.

SrO is a component for improving weather resistance as well as MgO. The content of SrO is preferably 0 to 12% by mass, more preferably 0 to 5% by mass. If the content of SrO is too large, the stability of the glass tends to be lowered.

BaO is a component that stabilizes glass and improves weather resistance. The content of BaO is preferably 1 to 30% by mass, more preferably 2 to 27%, and further preferably 3 to 25% by mass. If the content of BaO is too small, the glass can not be sufficiently stabilized or the weatherability can not be sufficiently improved. On the other hand, if the content of BaO is too large, crystals due to BaO may easily precipitate during molding.

ZnO is a component that improves the stability and weatherability of glass. The content of ZnO is preferably 0 to 13%, more preferably 0 to 12%, and even more preferably 0 to 10% in mass%. If the content of ZnO is excessively large, the melting property is lowered and the melting temperature is increased, resulting in a case where desired optical characteristics are not obtained in some cases. In addition, the stability of the glass is deteriorated, and crystals due to the ZnO component tend to precipitate.

As described above, RO and ZnO have an effect of improving stabilization of the glass, and particularly when P ₂ O ₅ is small, the effect is easily exhibited.

Incidentally, the ratio (P ₂ O ₅ / RO) of the content of P ₂ O ₅ for the RO is preferably 1.0 ~ 1.9, more preferably 1.2 to 1.8. If the ratio (P ₂ O ₅ / RO) is too small, the liquidus temperature becomes high, and devitrification due to RO may be easily precipitated. On the other hand, if P ₂ O ₅ / RO is too large, the weatherability tends to decrease.

K ₂ O is a component that lowers the melting temperature. The content of K ₂ O is preferably 8 to 20% by mass, and more preferably 12.5 to 19.5% by mass. If the content of K ₂ O is too small, the melting temperature is increased, and desired optical characteristics may not be obtained in some cases. On the other hand, if the content of K ₂ O is excessively large, crystals originating from K ₂ O tend to be precipitated during molding, and vitrification may become unstable.

Na ₂ O is a component that lowers the melting temperature just like K ₂ O. The content of Na ₂ O is preferably 0 to 12%, more preferably 0 to 7%. If the content of Na ₂ O is excessively large, vitrification may become unstable.

CuO is a component for absorbing near-infrared rays. The content of CuO is preferably 0.3 to 20%, more preferably 0.3 to 15%, and still more preferably 0.4 to 13% by mass. If the content of CuO is too small, desired near infrared ray absorption characteristics may not be obtained. On the other hand, if the content of CuO is too large, the light transmittance of the ultraviolet to visible region may be easily lowered. In addition, vitrification may become unstable. Further, in order to obtain desired optical characteristics, the content of CuO is preferably adjusted appropriately according to the thickness of the plate.

In addition to the above-mentioned components, other additives such as B ₂ O ₃ , Nb ₂ O ₅ , Y ₂ O ₃ , La ₂ O ₃ , Ta ₂ O ₅ , CeO ₂ or Sb ₂ O ₃ , . Specifically, the content of each of these components is preferably 0 to 3% by mass, and more preferably 0 to 2% by mass.

By having the above composition, it becomes possible to achieve both a higher light transmittance in the visible region and a better light absorption property in the infrared region. Concretely, the light transmittance at a wavelength of 400 nm is preferably 78% or more, more preferably 80% or more, and the light transmittance at a wavelength of 500 nm is preferably 83% or more, Is 85% or more. On the other hand, the light transmittance at a wavelength of 700 nm is preferably 12% or less, more preferably 9% or less, and the light transmittance at 800 nm is preferably 5% or less, more preferably 3 % Or less.

In addition, by having the above composition, it is possible to lower the liquidus temperature. Specifically, the liquidus temperature is preferably 770 占 폚 or lower, and more preferably 750 占 폚 or lower. If the liquidus temperature is excessively high, the liquidus temperature tends to be easily disintegrated at the time of molding.

Modifications;

2 is a schematic cross-sectional view showing a modified example of an infrared ray absorbing glass plate according to an embodiment of the present invention.

As shown in Fig. 2, in the modified example, the antireflection film 2 is formed on the first main surface 1a of the infrared ray absorbing glass plate 1. As shown in Fig. An infrared reflecting film 3 is formed on the second main surface 1b of the infrared ray absorbing glass plate 1. [

The antireflection film 2 is a film having a function of reducing the reflectance. The antireflection film 2 may be a film having a lower reflectance in the case of forming the antireflection film 2 than in the case of not forming the antireflection film 2 and is not necessarily a film having a reflectance of zero. Above all, in the present invention, the antireflection film 2 may not be formed.

The antireflection film 2 can be constituted by, for example, a dielectric multilayer film in which a low refractive index film having a relatively low refractive index and a high refractive index film having a relatively high refractive index are alternately laminated. The number of laminated dielectric multilayer films is not particularly limited, but is usually about 3 to 5 layers. The antireflection film 2 may be composed of a low refractive index film having a refractive index lower than that of the infrared ray absorbing glass plate 1. [

The infrared reflective film 3 is a film having a function of reflecting infrared rays. The infrared reflecting film 3 may be composed of, for example, SiO ₂ , Nb ₂ O ₅ or TiO ₂ .

Also in this modified example, since the thickness of the infrared absorbing glass plate 1 is thin, the solid-state imaging device device can be miniaturized when used in the solid-state imaging device.

Hereinafter, a method of manufacturing the infrared ray absorbing glass plate of the present invention such as the infrared ray absorbing glass plate 1 will be described.

(Manufacturing Method of Infrared Absorption Glass Sheet)

The infrared absorption glass sheet of the present invention can be produced, for example, as follows.

First, a plate-shaped glass base material constituted by a phosphate-based glass is prepared.

The glass base material can be produced by melting raw material powder batches of phosphate-based glass prepared so as to have a desired composition and shaping into a plate. As the phosphate-based glass, for example, a glass having the above-described composition can be used.

The melting temperature is preferably 900 to 1200 占 폚, more preferably 900 to 1000 占 폚. If the melting temperature is too low, homogeneous glass may not be obtained well. On the other hand, if the melting temperature is excessively high, Cu ions may be reduced and easily shifted from Cu ²⁺ to Cu ⁺ in some cases, and desired optical properties may not be obtained in some cases.

The forming method is not particularly limited, and for example, a forming method such as an injection method, a roll-out method, a down-draw method, or a lead-free method can be used.

Subsequently, the plate-shaped glass base material prepared as described above is polished by physical polishing (polishing step). In the polishing step, it is preferable that the thickness of the glass base material is 0.23 mm or more and 0.3 mm or less by physical polishing. If the thickness of the glass base material is excessively thinned by physical polishing, the glass base material may be cracked. If the thickness of the glass base material is excessively large, the thickness of the glass plate may not be sufficiently thinned in an etching process to be described later.

In the polishing step, the glass base material is polished to a thickness of 0.3 mm by, for example, lapping, and then polished to a thickness of 0.23 mm or more and 0.3 mm by optical polishing to obtain a polished glass base material .

Next, the physically polished glass base material is etched by immersing it in an alkaline detergent in a vertically standing state (etching step). Thereby, the infrared absorption glass sheet of the present invention having a thickness of 0.2 mm or less can be obtained.

As described above, in the method of manufacturing an infrared ray absorbing glass plate according to the present invention, an infrared ray absorbing glass plate having a thickness of 0.2 mm or less, which is difficult to obtain conventionally, can be easily manufactured. This reason can be explained as follows.

In the conventional method of reducing the thickness of the infrared ray absorbing glass plate by physical polishing, if the thickness of the carrier is made thinner for the purpose of thinning the thickness of the glass plate to 0.2 mm or less, cracks may occur in the carrier. Further, even when the thickness of the glass plate could be made thin, cracks were generated in the glass plate when the glass plate was taken out from the carrier. Further, even when a glass sheet having a large area was produced, cracking occurred at the time of cutting.

On the other hand, the inventors of the present invention have found that when a phosphate glass base material having a certain thickness reduced by physical polishing as described above is immersed in an alkali detergent, a glass plate having a thickness of 0.2 mm or less and having less cracking is obtained I found out. This reason is considered as follows.

Phosphate-based glass has a low alkali resistance, as compared with other glasses such as a fluorophosphate-based glass. Therefore, in the etching step with the alkali detergent, it is thought that polishing marks or micro cracks of the glass base material are melted and there are no marks or micro cracks on the first and second major surfaces and side surfaces of the obtained infrared ray absorbing glass plate do. It is considered that the infrared absorption glass sheet is not cracked even if the thickness of the infrared absorption glass sheet is increased because there is no starting point of cracking of the infrared absorption glass sheet by eliminating polishing marks or micro cracks.

The alkali detergent is not particularly limited, but for example, it is possible to use an alkaline component such as Na, K, a surfactant such as triethanolamine, benzyl alcohol or glycol, or an alkaline detergent containing water or alcohol or the like.

As the alkali component contained in the alkaline detergent, it is preferable that an alkali salt of a chelating agent such as aminopolycarboxylic acid is contained. Examples of the alkali salts of aminopolycarboxylic acids include sodium salts and potassium salts such as diethylenetriamine acetic acid, ethylenediamine acetic acid, triethylenetetraamine hexacetic acid and nitrilo triacetic acid. Among these, sodium diethylenetriamine acetic acid, sodium disodium ethylenediamineacetate, triethylenetetramine and sodium triacetinone nitrate and sodium nitrilotriacetate are preferably used, and especially diethylenetriamine acetoacetate is preferably used do.

The immersion temperature in the alkaline detergent is not particularly limited, but may be, for example, 20 ° C to 40 ° C.

The immersion time in the alkaline detergent is not particularly limited, but may be, for example, from 1 hour to 3 hours. Further, it is preferable that the physically polished glass base material is immersed in an alkaline detergent for 1 hour to 3 hours in a vertically standing state, then turned upside down and dipped for the same time. In this case, an infrared absorbing glass sheet having a uniform thickness distribution can be obtained.

The pH of the alkali detergent is preferably at least 7.1 and more preferably at least 8.0 from the viewpoint of preventing further micro cracks from occurring and preventing further cracking of the obtained infrared ray absorbing glass plate.

Further, in the obtained infrared ray absorbing glass plate, the area of the first and second main surfaces can be increased because cracks hardly occur. For example, the area of the first main surface may be 100 mm 2 or more and 25000 mm 2 or less. A more preferable range of the area of the first main surface is not less than 400 mm 2 and not more than 25000 mm 2, more preferably not less than 1000 mm 2 and not more than 25000 mm 2, still more preferably not less than 2500 mm 2, not more than 25000 mm 2, , And 25000 mm2 or less. Even in an infrared absorbing glass sheet having a large area of the first and second main surfaces, cracks do not occur well, so that they can be cut to a desired size and used. In this case, the infrared absorbing glass sheet can be manufactured more efficiently.

(Solid-state image pickup device)

3 is a schematic sectional view showing a solid-state image pickup device using an infrared ray absorbing glass plate according to an embodiment of the present invention. 3, the solid-state imaging device 10 includes an infrared-ray absorbing glass plate 1, a solid-state imaging element 11, a package 12, and an adhesive layer 13.

The package 12 is made of ceramic. The solid-state image pickup device 11 is housed inside the package 12. [ An infrared absorbing glass plate 1 is formed in the opening of the package 12. The package 12 and the infrared ray absorbing glass plate 1 are bonded to each other by an adhesive layer 13. The adhesive layer 13 may be composed of a suitable ultraviolet curable resin or a thermosetting resin.

The solid-state image sensing device 10 according to the present embodiment has the infrared absorbing glass plate 1 formed on the light incident side of the solid-state image sensing device 11 so that the solid-state image sensing device 11 The light can be incident on the light guide plate. As described above, since the infrared absorption glass plate 1 constituting the solid-state imaging element device 10 has a thickness as small as 0.2 mm or less, the solid-state imaging device 10 is miniaturized.

Hereinafter, the present invention will be clarified by taking a concrete example of the present invention. The present invention is not limited to the following examples.

(Example 1)

Based glass raw materials prepared so as to have a composition of 46% P ₂ O ₅ , 7% Al ₂ O ₃ , 3% MgO, 4% CaO, 20% BaO, 16% K ₂ O and 4% CuO The powder was melted at a temperature of 850 to 1300 占 폚 and molded into a plate by a roll-out method to obtain a plate-shaped glass base material.

The obtained glass base material was cut into a size of 125.1 mm in length and 100 mm using a dicer, and the cut glass base material was placed on the hole portion of the carrier set in the lower half of the double-side grinder, ) Was pressed down, and both surfaces were polished while flowing a polishing liquid containing Al ₂ O ₃ while rotating the assumed half, the lower half, and the carrier, and the thickness of the glass base material was 0.30 mm. Subsequently, the glass base material was further polished with CeO ₂ to make the thickness of the glass base material 0.25 mm.

Next, the polished glass base material was immersed in an alkali detergent having a composition of 37% by weight of Na component, 20% by weight of triethanolamine and 43% by weight of water, at a temperature of 30 DEG C for 120 minutes, Mm to obtain an infrared absorbing glass plate having a thickness of 0.15 mm.

The alkali detergent contains sodium diethylene triaminomethylacetate as a component of Na.

The obtained infrared absorbing glass plates (30 sheets) were grasped at both ends and lifted horizontally. As a result, no cracks were observed, and side surfaces were observed with an optical microscope, and as a result, microcracks did not exist.

For the obtained infrared absorbing glass plate (30 sheets), the three-point bending strength at a point-to-point distance of 2.5 mm was measured. As a result, it was 35 to 350 N / mm 2. Though the thickness was as small as 0.15 mm, .

(Comparative Example 1)

Instead of placing the raw material powder of the phosphate-based glass, in _{mass%, Al 2 O 3 10%} , AlF 3 10%, MgF 2 6%, CaF 2 15%, SrF 2 24%, SrF 2 18%, BaO 3%, An infrared absorption glass plate was obtained in the same manner as in Example 1 except that the raw material powder arrangement of fluorophosphate glass prepared so as to have a composition of LiF 9%, Li ₂ O 1%, and CuO 4% was used.

However, in Comparative Example 1, since the fluorophosphate glass has a high alkali resistance and is not etched in the etching process using an alkali detergent, the thickness of the infrared absorption glass plate is 0.25 mm and the infrared absorption A glass plate could not be obtained.

The infrared absorption glass sheet (30 sheets) made of the fluorophosphate-based glass produced as described above was held at both ends and lifted horizontally, and as a result, no crack occurred. However, when the side was observed with an optical microscope, microcracks of about 1 占 퐉 to 10 占 퐉 were present.

Further, for the obtained infrared absorbing glass plate (30 sheets), the three-point bending strength at a point-to-point distance of 2.5 mm was measured and found to be 30 to 60 N / mm 2.

An array of infrared absorbing glass plates;

4 is a schematic cross-sectional view for explaining a manufacturing process of an infrared absorbing glass plate array according to another embodiment of the present invention. 5 is a schematic plan view for explaining a manufacturing process of an infrared absorbing glass plate array according to another embodiment of the present invention. The infrared absorbing glass plate used for a camera or the like of a smart phone is generally small in size. Therefore, an infrared absorbing glass plate of a large size may be manufactured and then divided by dicing or the like to produce an array of infrared absorbing glass plates of a small size, and an infrared absorbing glass plate of a small size may be taken out from the array. Hereinafter, a method for manufacturing an array of infrared absorbing glass plates will be described.

First, as the glass base material, an alkali-washed large-size infrared absorbing glass plate 21 is prepared. Optical films 22 and 23 such as an antireflection film and an infrared ray reflection film are formed on the first main surface 21a and the second main surface 21b of the infrared ray absorbing glass plate 21 as necessary. In the present embodiment, the optical films 22 and 23 are composed of a dielectric multilayer film.

The infrared absorbing glass plate 21 on which the optical films 22 and 23 are formed is adhered onto the support 30. As the support 30, for example, a UV tape whose bonding strength is lowered by ultraviolet irradiation can be used.

Next, along the cutting line A, the infrared absorbing glass plate 21 on the support 30 is cut by a dicing saw or the like, and is divided into a plurality of infrared absorbing glass plates arranged in a matrix.

Next, a plurality of infrared absorption glass plates adhered to the support 30 are dipped in the alkali detergent together with the support 30 to etch the side surfaces of the infrared absorption glass plate. As a result, micro cracks and the like generated on the side surface can be removed by dicing. For this reason, an infrared absorbing glass sheet which does not generate cracks well can be obtained.

As described above, an infrared absorbing glass plate array according to another embodiment of the present invention can be manufactured.

6 is a schematic plan view showing an array of infrared ray absorbing glass plates according to another embodiment of the present invention. The array 40 of infrared absorbing glass plates according to the present embodiment includes a support 30 and a plurality of infrared absorbing glass plates 31 arranged in a matrix on the support 30. In this embodiment, since the support 30 is made of UV tape, the bonding strength can be lowered by irradiating ultraviolet rays, so that the infrared ray absorbing glass plate 31 can be easily removed from the supporting body 30. [

In the above embodiment, the infrared ray absorbing glass plate 21 is cut by dicing, but it may be cut by laser irradiation instead of cutting by dicing. In the case of cutting by laser irradiation, microcracks or the like do not occur on the cut surface, and hence the subsequent etching step may be omitted.

1: infrared absorption glass plate
1a and 1b: first and second main faces
1c: Side
2: antireflection film
3: Infrared ray reflective film
10: Solid-state imaging device
11: Solid-state image pickup device
12: Package
13: Adhesive layer
21: infrared absorption glass plate
21a, 21b: first and second main faces
22, 23: optical film
30: Support
31: infrared absorption glass plate
40: Array of infrared absorption glass plates

Claims (19)

1. An infrared absorbing glass plate having first and second main surfaces facing each other and side surfaces connecting the first and second main surfaces,
It is composed of phosphate glass,
A thickness of 0.2 mm or less,
Wherein no microcracks exist on the side surface. The method according to claim 1,
Wherein said phosphate glass comprises 25 to 60% of P ₂ O ₅ , 2 to 19% of Al ₂ O _3, 5 to 20% of RO (provided that R is at least one kind selected from Mg, Ca, Sr and Ba) 45%, 0 to 13% of ZnO, 8 to 20% of K ₂ O, 0 to 12% of Na ₂ O and 0.3 to 20% of CuO, and substantially no fluorine. 3. The method according to claim 1 or 2,
Wherein no abrasive marks are present on the first and second main surfaces. 4. The method according to any one of claims 1 to 3,
Wherein an area of the first main surface is 100 mm 2 or more and 25000 mm 2 or less. 5. The method of claim 4,
Wherein an area of the first main surface is not less than 1000 mm 2 and not more than 25000 mm 2. 6. The method according to any one of claims 1 to 5,
Point bending strength at a point-to-point distance of 2.5 mm is not less than 35 N / mm < 2 >. 4. The method according to any one of claims 1 to 3,
Wherein an area of the first main surface is at least 1 mm 2 and less than 1000 mm 2. 8. The method according to any one of claims 1 to 7,
An infrared absorption glass sheet used in a solid-state imaging device. 9. The method according to any one of claims 1 to 8,
Wherein an optical film is formed on at least one of the first main surface and the second main surface. 10. The method of claim 9,
Wherein the optical film is a dielectric multilayer film. An array of infrared absorbing glass plates comprising a support and a plurality of infrared absorbing glass plates according to any one of claims 1 to 10 arranged in a matrix on the support. 9. A manufacturing method of an infrared absorbing glass plate according to any one of claims 1 to 8,
A polishing step of physically polishing a plate-shaped glass base material constituted by a phosphate-based glass,
And an etching step of etching the physically polished glass base material by immersing the glass base material in an alkali detergent. 13. The method of claim 12,
Wherein the thickness of the glass base material is 0.23 mm or more and 0.3 mm or less by the physical polishing in the polishing step. The method according to claim 12 or 13,
Wherein the etching is performed by immersing the physically polished glass base material in an alkali detergent having a pH of 7.1 or more. 15. The method according to any one of claims 12 to 14,
Wherein the alkali detergent contains an alkali salt of an aminopolycarboxylic acid. 16. The method according to any one of claims 12 to 15,
The infrared absorbing glass plate manufacturing method according to claim 9 or 10,
Further comprising the step of forming the optical film on at least one of the first main surface and the second main surface of the glass base material after etching. A method for producing an array of infrared absorption glass plates according to claim 11,
A method for manufacturing a glass base material, comprising the steps of: preparing the etched glass base material by the method according to any one of claims 12 to 16;
Placing the glass base material on the support;
A step of dicing the glass base material on the support and dividing the glass base material into the plurality of infrared absorbing glass plates arranged in a matrix;
And an etching step of etching the infrared absorbing glass plate on the support by immersing the infrared absorbing glass plate in the alkali detergent. 18. The method of claim 17,
Wherein the support is a UV tape whose bonding strength is lowered by irradiation with ultraviolet rays. A solid-state image pickup device comprising the infrared absorbing glass plate according to any one of claims 1 to 10.

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