TWI791530B - Infrared-absorbing glass plate, manufacturing method thereof, and solid-state imaging device - Google Patents

Abstract

The present invention provides an infrared-absorbing glass plate capable of downsizing a solid-state imaging device. The infrared-absorbing glass plate 1 of the present invention has first and second main surfaces 1a, 1b facing each other and a side surface 1c connecting the first and second main surfaces 1a, 1b, and contains P ⁵⁺ 10~70%, Al ³⁺ 7~50%, Cu ²⁺ 0.1~15%, and fluorophosphate glass containing F ^- 10~90%, O ^2- 10~90% in terms of anion % Composition, the thickness is 0.2 mm or less, and there are no microcracks on the side 1c.

Description

Infrared-absorbing glass plate, manufacturing method thereof, and solid-state imaging device

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

A solid-state imaging device such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) is used in a camera of a digital camera or a smart phone. These solid-state imaging device devices have a wide range of light-receiving sensitivity, so in order to conform to human vision, it is necessary to remove light in the infrared region. Patent Document 1 below discloses an infrared-absorbing glass plate made of fluorophosphate-based glass as a near-infrared cut filter for cutting light in the infrared region. In Patent Document 1, the thickness of the glass plate is reduced by physical grinding.

[Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2007-99604

In recent years, solid-state imaging device devices have been required to be further downsized. Therefore, further thinning is required also for the infrared-absorbing glass plate constituting the solid-state imaging device. However, in the thinning method by physical grinding like Patent Document 1, if the thickness of the glass plate is too thin, the glass plate may be broken. Therefore, the thickness of the glass plate cannot be sufficiently reduced, and the solid-state imaging device device may not be sufficiently miniaturized.

An object of the present invention is to provide an infrared-absorbing glass plate capable of downsizing a solid-state imaging device, a method of manufacturing the infrared-absorbing glass plate, and a solid-state imaging device.

The infrared-absorbing glass plate of the present invention is characterized in that it has first and second main surfaces facing each other, and a side surface connecting the first and second main surfaces, and contains P in terms of cation %. ⁵⁺ 10~70%, Al ³⁺ 7~50%, Cu ²⁺ 0.1~15%, and fluorophosphate glass containing F ^- 10~90%, O ^2- 10~90% in terms of anion % , the thickness is 0.2 mm or less, and there is no microcrack on the above-mentioned side.

In the conventional method of reducing the thickness of the infrared-absorbing glass plate by physical grinding, if the thickness of the carrier is reduced to reduce the thickness of the glass plate to 0.2 mm or less, the carrier may be broken. Also, even when the thickness of the glass plate can be reduced, the glass plate is cracked when taken out from the carrier. In addition, even if a glass plate with a large area is produced, it will be broken when cut.

In view of such a problem, the present inventors have found that if the fluorophosphate-based glass base material whose thickness has been reduced to some extent by physical polishing is immersed in an alkaline detergent, a thickness of 0.2 mm or less and A glass plate that is not prone to breakage. The reason for this is considered as follows.

Fluorophosphate-based glass usually has high alkali resistance, but the fluorophosphate-based glass of the present invention contains more than 7 cations of Al ³⁺ which lowers the alkali resistance, so the alkali resistance is relatively low. Therefore, it is considered that the microcracks of the glass base material were melted in the etching step by the alkaline detergent, and no microcracks existed on the side surface of the obtained infrared-absorbing glass plate. It is believed that the origin of cracking of the infrared-absorbing glass plate disappears due to the disappearance of microcracks, so that the strength of the infrared-absorbing glass plate increases, and it is difficult to break even if the thickness is thin.

In the infrared-absorbing glass plate of the present invention, it is preferable that there are no grinding marks on the first and second main surfaces.

In the infrared-absorbing glass plate of the present invention, it is preferable that the areas of the above-mentioned first and second main surfaces are not less than 100 mm ² and not more than 25000 mm ² .

The infrared-absorbing glass plate of the present invention preferably has a three-point flexural strength of 35 N/mm ² or more when the distance between fulcrums is 2.5 mm.

In the infrared-absorbing glass plate of the present invention, it is preferable that the areas of the first and second main surfaces are 1 mm ² or more and less than 1000 mm ² .

The infrared-absorbing glass plate of the present invention is preferably used for a solid-state imaging device.

The array of infrared-absorbing glass plates of the present invention includes: a support, and a plurality of the above-mentioned infrared-absorbing glass plates of the present invention arranged in a matrix on the support.

The manufacturing method of the infrared-absorbing glass plate of the present invention includes: a grinding step, which is to physically grind the plate-shaped glass base material, wherein the glass base material contains 10-70% of P ⁵⁺ and Al ³⁺ in terms of cation % 7~50%, Cu ²⁺ 0.1~15%, and fluorophosphate glass containing F ^- 10~90%, O ^2- 10~90% in terms of anion %; and the etching step, which will go through the above The physically ground glass base material is etched by immersing it in alkaline detergent.

In the manufacturing method of the infrared-absorbing glass plate of the present invention, it is preferable that in the grinding step, the thickness of the glass base material is adjusted to be more than 0.2 mm and not more than 0.3 mm by the physical grinding.

In the method of manufacturing an infrared-absorbing glass plate of the present invention, etching is preferably carried out by immersing the above-mentioned physically ground glass base material in an alkaline detergent with a pH value of 7.1 or higher in the above-mentioned etching step.

The above-mentioned alkaline detergent is preferably an alkaline salt containing amino polycarboxylic acid.

The solid-state imaging device device of the present invention includes an infrared-absorbing glass plate constructed according to the present invention.

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

1: Infrared absorbing glass plate

1a, 1b: the first and second main surfaces

1c: side

2: Anti-reflection film

3: Infrared reflective film

10: Solid-state imaging device

11: Solid-state imaging element

12: Encapsulation

13: Adhesive layer

21: Mother glass plate

21a, 21b: the first and second main surfaces

22, 23: Optical film

30: support body

31: Infrared absorbing glass plate

40: Array of infrared absorbing glass plates

A: cutting line

Fig. 1 is a schematic perspective view showing an infrared-absorbing glass plate of the present invention.

Fig. 2 is a schematic cross-sectional view showing a modified example of the infrared-absorbing glass plate of the present invention.

Fig. 3 is a schematic cross-sectional view showing a solid-state imaging device using the infrared-absorbing glass plate of the present invention.

Fig. 4 is a schematic cross-sectional view for explaining the manufacturing steps of the array of infrared-absorbing glass plates of the present invention.

Fig. 5 is a schematic plan view for explaining the manufacturing steps of the array of infrared-absorbing glass plates of the present invention.

Fig. 6 is a schematic plan view showing an array of infrared-absorbing glass plates of the present invention.

A preferred embodiment will be described below. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. In addition, in each drawing, members having substantially the same functions may be referred to by the same symbols.

(infrared absorbing glass plate)

Fig. 1 is a schematic perspective view showing an infrared-absorbing glass plate of the present invention. As shown in Figure 1 As shown, the planar shape of the infrared-absorbing glass plate 1 is a rectangle. The corners of the infrared-absorbing glass plate 1 may also be chamfered.

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

The infrared-absorbing glass plate 1 is made of CuO-containing fluorophosphate-based glass. Therefore, the infrared absorption function of the infrared absorption glass plate 1 is excellent.

The thickness of the infrared-absorbing glass plate 1 is 0.2 mm or less. Preferably it is 0.19 mm or less, more preferably 0.16 mm or less. Since the infrared-absorbing glass plate 1 is as thin as 0.2 mm or less, when used in a solid-state imaging device, the size of the solid-state imaging device can be reduced. Furthermore, if the thickness is too thin, cracks may easily occur when the infrared-absorbing glass plate 1 is lifted during the conveying step, so the thickness is preferably at least 0.05 mm, more preferably at least 0.08 mm.

In this way, the infrared-absorbing glass plate 1 is excellent in the infrared-absorbing function, and since the solid-state imaging device can be downsized, it can be suitably used for the solid-state imaging device.

Generally, fluorophosphate-based glass has low strength and is easily broken if it is thinned. However, in the present invention, there are no microcracks on the side surface 1c of the infrared-absorbing glass plate 1, so even if the thickness is set to 0.2mm or less, it is not easy. produce a rupture. The so-called microcracks refer to cracks with a length of 1 to 15 μm. Microcracks may become the starting point of cracks when the infrared-absorbing glass plate 1 is bent. especially on the side When microcracks exist on the surface 1c, they are likely to be the starting point of cracks. Therefore, when there are no microcracks on the side surface 1c, breakage of the infrared-absorbing glass plate 1 can hardly occur. Furthermore, the presence or absence of microcracks can be confirmed by an optical microscope.

In addition, not only the side surface 1c but also the first and second main surfaces 1a, 1b may be the origin of cracks when microcracks exist. Therefore, it is more preferable that there are no microcracks on the first and second main surfaces 1a, 1b other than the side surface 1c from the viewpoint of making the infrared-absorbing glass plate 1 less likely to be cracked.

In addition, it is preferable that the first and second main surfaces 1a, 1b of the infrared-absorbing glass plate 1 have no traces of polishing during manufacture. In this case, breakage of the infrared-absorbing glass plate 1 can be made less likely to occur. From the viewpoint of making the infrared-absorbing glass plate 1 less likely to be cracked, it is more preferable that there are no grinding traces on the side surface 1c other than the first and second main surfaces 1a, 1b. Furthermore, the grinding marks can be confirmed by an atomic force microscope.

The three-point flexural strength when the distance between the fulcrums of the infrared-absorbing glass plate 1 is 2.5 mm is preferably at least 35 N/mm ² , more preferably at least 50 N/mm ² . When the three-point flexural strength is more than the above lower limit, the infrared-absorbing glass plate 1 is less likely to be broken. Furthermore, the upper limit of the three-point flexural strength of the infrared-absorbing glass plate 1 is not particularly limited, but it is about 450 N/mm ² in terms of the nature of the material.

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

Details of materials:

Infrared-absorbing glass 1 contains 10-70% of P ⁵⁺ , 7-50% of Al ³⁺ , and 0.1-15% of Cu ²⁺ in terms of cation %. Hereinafter, the reasons for limiting the glass composition as described above will be described.

P ⁵⁺ is a component used to form a glass skeleton. The content of P ⁵⁺ is preferably 10-70%, more preferably 18-63%, and most preferably 25-55%. If the content of P ⁵⁺ is too small, vitrification tends to become unstable. On the other hand, when the content of P ⁵⁺ is too high, the devitrification resistance tends to decrease.

Al ³⁺ is a component that reduces alkali resistance. The content of Al ³⁺ is preferably 7-50%, more preferably 7-31%, and most preferably 7-16%. If the content of Al ³⁺ is too small, the alkali resistance is improved and it is difficult to etch with an alkaline detergent, so it is difficult to reduce the thickness of the infrared-absorbing glass plate. In addition, since microcracks on the side are difficult to disappear, the strength of the infrared-absorbing glass plate is weakened and easily broken. On the other hand, if the content of Al ³⁺ is too high, the meltability tends to decrease and the melting temperature tends to rise. Furthermore, if the melting temperature rises, Cu ions are easily reduced and converted from Cu ²⁺ to Cu ⁺ , so it is difficult to obtain desired optical properties. Specifically, the light transmittance in the near-ultraviolet to visible region decreases, or the near-infrared absorption property tends to decrease.

Cu ²⁺ is a component used to absorb near-infrared rays. The content of Cu ²⁺ is preferably 0.1-15%, more preferably 2-13%, and most preferably 4-10%. If the content of Cu ²⁺ is too small, it is difficult to obtain the above effects. On the other hand, if the content of Cu ²⁺ is too high, the light transmittance in the ultraviolet to visible light region is likely to decrease. Moreover, there exists a tendency for devitrification resistance to fall.

In addition to the above-mentioned components, various components shown below may be contained.

Li ⁺ is a component that lowers the melting temperature. The content of Li ⁺ is preferably 0-30%, especially 0.1-25%. When the content of Li ⁺ is too large, the devitrification resistance tends to decrease.

Na ⁺ is a component that lowers the melting temperature similarly to Li ⁺ . The content of Na ⁺ is preferably 0-30%, particularly preferably 0.1-20%. When the content of Na ⁺ is too large, the devitrification resistance tends to decrease.

K ⁺ is also a component that lowers the melting temperature similarly to Li ⁺ . The content of K ⁺ is preferably 0-30%, especially 0.1-20%. When the content of K ⁺ is too high, the devitrification resistance tends to decrease.

Mg ²⁺ is a component that improves devitrification resistance. The content of Mg ²⁺ is preferably 0-20%, especially 0.1-11%. If the content of Mg ²⁺ is too high, the stability of vitrification is likely to decrease.

Ca ²⁺ is a component that improves devitrification resistance similarly to Mg ²⁺ . The content of Ca ²⁺ is preferably 0-12%, especially 0.1-10%. If the content of Ca ²⁺ is too high, the stability of vitrification is likely to decrease.

Sr ²⁺ is also a component that improves devitrification resistance similarly to Mg ²⁺ . The content of Sr ²⁺ is preferably 0-20%, especially 0.1-10%. If the content of Sr ²⁺ is too high, the stability of vitrification is likely to decrease.

Ba ²⁺ is also a component that improves devitrification resistance similarly to Mg ²⁺ . The content of Ba ²⁺ is preferably 0-13%, particularly preferably 0.1-11%. If the content of Ba ²⁺ is too high, the stability of vitrification is likely to decrease.

Zn ²⁺ is also a component that improves devitrification resistance similarly to Mg ²⁺ . The content of Zn ²⁺ is preferably 0-10%, especially 0.1-5%. If the content of Zn ²⁺ is too high, the stability of vitrification is likely to decrease.

In addition, in the optical glass of the present invention, Bi ³⁺ , La ³⁺ , Y ³⁺ , Gd ³⁺ , Te ⁴⁺ , Si ⁴⁺ , Ta ⁵⁺ , Nb ⁵⁺ , Ti ⁴⁺ , Zr ⁴⁺ , or Sb ³⁺ are used as cationic components. Specifically, the contents of these ingredients are preferably 0-3%, more preferably 0-1%.

Since Pb components (Pb ²⁺ etc.) and As components (As ³⁺ etc.) are environmental load substances, it is preferable not to contain substantially in this invention. Here, the term "substantially not containing" means that these components are not intentionally added to the glass, and does not mean that inevitable impurities are completely excluded. More objectively, it means that the content of these ingredients including impurities does not reach 0.1%.

The composition of the anion component preferably contains F ^- 10-90%, and O ^2- 10-90%, and more preferably contains F ^- 10-70%, and O ^2- 30-90%. If the F ^- content is too small (the O ^{2 -} content is too high), the devitrification resistance tends to decrease. On the other hand, if the content of F ^- is too much (the content of O ^2- is too small), the stability of vitrification is likely to decrease.

By having the above composition, both higher light transmittance in the visible light region and more excellent light absorption characteristics in the infrared region can be achieved. Specifically, the light transmittance at a wavelength of 500nm Preferably it is 75% or more, more preferably 77% or more. On the other hand, the light transmittance at a wavelength of 700nm is preferably not more than 27%, more preferably not more than 25%, and the light transmittance at a wavelength of 1200nm is preferably not more than 38%, more preferably not more than 36%.

Variation example:

Fig. 2 is a schematic cross-sectional view showing a modified example of the infrared-absorbing glass plate of the present invention.

In the modified example shown in FIG. 2 , an antireflection film 2 is provided on the first main surface 1 a of the infrared absorbing glass plate 1 . In addition, an infrared reflective film 3 is provided on the second main surface 1b of the infrared absorbing glass plate 1 .

The anti-reflection film 2 is a film having a function of reducing reflectance. The antireflection film 2 may be a film whose reflectance is lowered when the antireflection film 2 is provided compared to the case where the antireflection film 2 is not provided, and is not necessarily a film whose reflectance becomes zero. Furthermore, in the present invention, the antireflection film 2 may not be provided.

The antireflection film 2 can be composed of, for example, a dielectric multilayer film in which a low-refractive-index film with a relatively relatively high refractive index and a high-refractive-index film with a relatively high refractive index are laminated alternately. The number of laminated layers of the above-mentioned dielectric multilayer film is not particularly limited, and is usually about 3 to 5 layers. Furthermore, the anti-reflection film 2 can also be made of a low-refractive-index film whose refractive index is lower than that of the infrared-absorbing glass plate 1 .

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

In this variation example, if the infrared-absorbing glass plate 1 is installed in a solid-state imaging device or the like so that the light-incident side becomes the anti-reflection film 2 and the light-emitting side becomes the infrared reflection film 3, visible light can be sufficiently suppressed. Penetrate and effectively cut off infrared rays. In addition, since the infrared-absorbing glass plate 1 is thin, when used in a solid-state imaging device, it is possible to reduce the size of the solid-state imaging device.

(Manufacturing method of infrared absorbing glass plate)

Hereinafter, the manufacturing method of the infrared-absorbing glass plate of this invention is demonstrated.

First, a raw material powder batch of fluorophosphate glass prepared so as to have a desired composition is melted and formed into a plate shape to obtain a glass base material.

The melting temperature is preferably from 700 to 900°C, more preferably from 700 to 850°C. If the melting temperature is too low, it may be difficult to obtain homogeneous glass. On the other hand, if the melting temperature is too high, Cu ions may be reduced to easily convert from Cu ²⁺ to Cu ⁺ , and it may be difficult to obtain desired optical properties.

In addition, it does not specifically limit as a forming method, For example, a forming method such as a slip casting method, a flattening method, a down-draw method, or a re-draw method can be used.

Next, the plate-shaped glass base material prepared in the above manner is ground by physical grinding (grinding step). In the grinding step, it is preferable to adjust the thickness of the glass base material by physical grinding. The whole is more than 0.2mm and less than 0.3mm. If the thickness of the glass base material is too thin by physical grinding, the glass base material may be broken. In addition, if the thickness of the glass base material is too thick, the thickness of the glass plate may not be sufficiently reduced in the following etching step.

In the grinding step, for example, the glass base material is ground to a thickness of about 0.3 mm by polishing and grinding, and then ground to a thickness of more than 0.2 mm and less than 0.3 mm by optical grinding, thereby obtaining a physically ground glass mother material.

Next, etching was performed by immersing the physically ground glass base material in an alkaline detergent in a vertically erected state (etching step). Thereby, the infrared-absorbing glass plate of this invention with a thickness of 0.2 mm or less can be obtained.

In this manner, in the method for producing an infrared-absorbing glass plate of the present invention, an infrared-absorbing glass plate having a thickness of 0.2 mm or less, which has been difficult to obtain until now, can be easily produced.

The alkaline detergent is not particularly limited, and for example, alkaline components such as Na and K, surfactants such as triethanolamine, benzyl alcohol, or ethylene glycol, or alkaline detergents containing water or alcohol can be used.

As the alkaline component contained in the alkaline detergent, an alkaline salt containing a chelating agent such as amino polycarboxylic acid is preferable. Examples of the basic salt of aminopolycarboxylic acid include sodium salts and potassium salts of diethylenetriaminepentaacetic acid, ethylenediaminetetraacetic acid, triethylenetetraminehexaacetic acid, and nitrilotriacetic acid. Among them, pentasodium diethylenetriaminepentaacetate, tetrasodium ethylenediaminetetraacetate, hexasodium triethylenetetraminehexaacetate, trisodium nitrilotriacetate can be preferably used, and diethyl Pentasodium triaminepentaacetate.

The immersion temperature in the alkaline detergent is not particularly limited, for example, it can be set at 20-40°C.

The immersion time in the alkaline detergent is not particularly limited, and may be, for example, 1 to 30 hours. Furthermore, it is ideal for the physically ground glass base material to be immersed in alkaline detergent for 1 to 30 hours in a vertical standing state, then reversed upside down and immersed for the same time. In this case, an infrared-absorbing glass plate with a more uniform thickness distribution can be obtained.

From the standpoint of being less likely to have microcracks and less prone to breakage of the obtained infrared-absorbing glass plate, the pH of the alkaline lotion is preferably 7.1 or higher, more preferably 8.0 or higher.

In addition, since the infrared-absorbing glass plate obtained by the above method is less likely to be cracked, the areas of the first and second main surfaces can be increased. For example, the areas of the first and second principal surfaces can be set to be not less than 100 mm ² and not more than 25000 mm ² . The area of the first and second main surfaces is more preferably in the range of 400 mm ² to 25000 mm ² , more preferably 1000 mm ² to 25000 mm ² , further preferably 2500 mm ² to 25000 mm ² , most preferably 5000 mm ² Above and below ^25000mm2 . Infrared-absorbing glass plates with relatively large first and second main surfaces are also less likely to be cracked, so they can be cut into desired sizes for use. In this case, an infrared-absorbing glass plate can be manufactured more efficiently. Furthermore, the areas of the first and second main surfaces after cutting are preferably not less than 1 mm ² and less than 1000 mm ² .

(solid-state imaging device)

Fig. 3 is a schematic diagram showing a solid-state imaging device using an infrared-absorbing glass plate of the present invention. Formal cross-section. As shown in FIG. 3 , the solid-state imaging device 10 includes an infrared-absorbing glass plate 1 , a solid-state imaging device 11 , a package 12 , and an adhesive layer 13 .

The package body 12 is made of ceramics. The solid-state imaging device 11 is housed inside the package 12 . In addition, an infrared-absorbing glass plate 1 is provided at the opening of the package 12 . Furthermore, the package body 12 and the infrared-absorbing glass plate 1 are bonded through the adhesive layer 13 . The adhesive layer 13 can be made of suitable ultraviolet curable resin or thermosetting resin.

The solid-state imaging device 10 is provided with an infrared-absorbing glass plate 1 on the light-incident side of the solid-state imaging device 11 , so that light in the infrared region can be sufficiently absorbed and incident on the solid-state imaging device 11 . In addition, since the thickness of the infrared-absorbing glass plate 1 constituting the solid-state imaging device 10 is as thin as 0.2 mm or less as described above, the solid-state imaging device 10 can be miniaturized. Furthermore, as the infrared-absorbing glass plate 1, an infrared-absorbing glass plate provided with an anti-reflection film and an infrared-reflecting film as shown in FIG. 2 can also be used.

(Array of Infrared Absorbing Glass Plates)

Fig. 4 is a schematic cross-sectional view for explaining the manufacturing steps of the array of infrared-absorbing glass plates of the present invention. 5 is a schematic plan view for explaining the manufacturing steps of the array of infrared-absorbing glass plates of the present invention. Infrared-absorbing glass plates used in cameras and the like for smartphones are generally of smaller size. Therefore, it is also possible to manufacture a mother glass plate including infrared-absorbing glass of a size that can take a plurality of glass plates, and divide it by cutting or the like to manufacture an array of individualized infrared-absorbing glass plates, and each infrared-absorbing The glass plate was removed from the array for use. Hereinafter, a method of manufacturing an array of infrared-absorbing glass plates will be described.

First, as a glass base material, a mother glass plate 21 composed of alkali-cleaned infrared-absorbing glass is prepared. On the first main surface 21 a and the second main surface 21 b of the mother glass plate 21 , optical films 22 and 23 such as an anti-reflection film or an infrared reflection film may be provided as needed.

The mother glass plate 21 provided with the optical films 22 and 23 is attached to the support 30 . As the support body 30, for example, a UV (Ultraviolet, ultraviolet) type in which the intensity is subsequently lowered by ultraviolet irradiation can be used.

Next, the mother glass plate 21 on the support body 30 is cut along the cutting line A with a wafer cutter or the like, and divided into a plurality of infrared-absorbing glass plates 31 arranged in a matrix.

Next, the plurality of infrared-absorbing glass plates 31 that were bonded to the support body 30 and separated into pieces were immersed together with the support body 30 in the above-mentioned alkaline detergent, and the side surfaces of the infrared-absorbing glass plates 31 were etched. Then, microcracks and the like generated on the side surface due to cutting can be removed. Therefore, the infrared-absorbing glass plate 31 that is less prone to breakage can be produced.

Furthermore, the mother glass plate 21 can also be cut by laser irradiation. In the case of cutting by laser irradiation, microcracks and the like are less likely to occur on the cut surface, so the etching step can also be omitted.

Fig. 6 is a schematic plan view showing an array of infrared-absorbing glass plates of the present invention produced as described above. The array 40 of infrared-absorbing glass plates of this embodiment includes a support 30 and a plurality of infrared-absorbing glass plates 31 arranged on the support 30 in a matrix. Again Or, when a UV band is used as the support body 30, the adhesion strength can be lowered by irradiating ultraviolet rays, and the infrared-absorbing glass plate 31 can be easily removed from the support body 30.

[Example]

Hereinafter, the present invention will be described based on examples. Furthermore, the present invention is not limited to the following examples.

Table 1 shows the examples (sample No.1-10) and comparative example (sample No.11) of the present invention.

The raw material powder batch prepared in such a way as to become the glass composition shown in Table 1 was melted at a temperature of 700~850°C, and formed into a plate by a flattening method to obtain a plate-shaped glass base material.

Use a slicer to cut the obtained glass base material into a size of 125.1mm square, and place the cut glass base material on the hole of the carrier that has been installed on the lower platen of the double-sided grinder, and place it on it Put down the upper platen and apply pressure, while rotating the upper platen, lower platen and the carrier, while flowing the polishing liquid containing Al ₂ O ₃ and grinding both sides, the thickness of the glass base material is adjusted to 0.3mm. Then, the glass base material was further ground with CeO ₂ to adjust the thickness of the glass base material to 0.25 mm.

Then, the ground glass base material is subjected to an alkaline washing process at a temperature of 30° C., in which the basic salt of an amino polycarboxylic acid is 37%, triethanolamine is 20%, and water is 43%. Infrared-absorbing glass plates (30 sheets each) having a size of 125 mm square and a thickness shown in Table 1 were obtained by immersing them in the solvent for 14 hours.

In the above-mentioned alkaline lotion, pentasodium diethylenetriaminepentaacetate is included as an alkaline salt of amino polycarboxylic acid.

The side surfaces of the obtained infrared-absorbing glass plates (30 pieces) were observed with an optical microscope to determine the presence or absence of microcracks.

Also, for the obtained infrared-absorbing glass plates (30 sheets), three-point flexural strengths at a distance between fulcrums of 2.5 mm were measured, and an average value was calculated.

As shown in Table 1, the samples of Nos. 1 to 10, which are examples of the present invention, had a thickness as thin as 0.16 mm or less, and were etched by alkaline detergent. Also, there are no microcracks on the side surface, and the three-point flexural strength is as high as 121N/mm ² or more despite its thin thickness.

On the other hand, the thickness of the sample of No. 11 which is a comparative example is the same as before etching, 0.25 mm, and it was not etched by alkaline lotion. Also, there are microcracks of about 1-10 μm on the side surface, and the three-point flexural strength is as low as 25N/mm ² .

1‧‧‧Infrared Absorbing Glass Plate

1a, 1b‧‧‧1st and 2nd main face

1c‧‧‧side

Claims (12)

An infrared-absorbing glass plate, characterized in that it has first and second main surfaces facing each other, and a side surface connecting the first and second main surfaces, and contains P ⁵⁺ in terms of cation % 10~70%, Al ³⁺ 7~50%, Cu ²⁺ 4.8~15%, Li ⁺ 0.1~30%, Mg ²⁺ 4.5~20%, Ba ²⁺ 0.1~13%, Ca ²⁺ 0~9.5 % and fluorophosphate glass containing F ^- 10~90% and O ^2- 10~90% in terms of anion %, the thickness is less than 0.2mm, and there is no microcrack on the above-mentioned side. The infrared-absorbing glass plate according to claim 1, wherein there are no grinding marks on the first and second main surfaces. The infrared-absorbing glass plate according to claim 1 or 2, wherein the areas of the first and second main surfaces are not less than 100 mm ² and not more than 25000 mm ² . For the infrared-absorbing glass plate of claim 1 or 2, the three-point flexural strength is 35 N/mm ² or more when the distance between fulcrums is 2.5 mm. The infrared-absorbing glass plate according to claim 1 or 2, wherein the areas of the first and second main surfaces are 1 mm ^{2 or} more and less than 1000 mm ² . The infrared-absorbing glass plate according to claim 1 or 2, which is used in a solid-state imaging device. An array of infrared-absorbing glass plates, characterized by comprising: a support, and a plurality of infrared-absorbing glass plates according to any one of Claims 1 to 6 arranged in a matrix on the support. A method for manufacturing an infrared-absorbing glass plate, characterized in that: it is the method for manufacturing an infrared-absorbing glass plate according to any one of Claims 1 to 6, and it is equipped with: a grinding step, which is for the plate-shaped glass base material Carry out physical grinding, wherein the glass base material is composed of P ⁵⁺ 10~70%, Al ³⁺ 7~50%, Cu ²⁺ 4.8~15%, Li ⁺ 0.1~30%, Mg ²⁺ 4.5% in terms of cation % ~20%, Ba ²⁺ 0.1~13%, Ca ²⁺ 0~9.5%, and fluorophosphate glass containing F ^- 10~90%, O ^2- 10~90% in terms of anion %; and etching step, which is to etch by immersing the above-mentioned physically ground glass base material in an alkaline detergent. The method of manufacturing an infrared-absorbing glass plate according to claim 8, wherein in the grinding step, the thickness of the glass base material is adjusted to be more than 0.2 mm and less than 0.3 mm by the physical grinding. The method of manufacturing an infrared-absorbing glass plate according to claim 8 or 9, wherein in the etching step, the etching is carried out by immersing the physically ground glass base material in an alkaline detergent with a pH value of 7.1 or higher. The method for manufacturing an infrared-absorbing glass plate as claimed in claim 8 or 9, wherein the above-mentioned alkaline detergent Contains basic salts of amino polycarboxylic acids. A solid-state imaging device, characterized by comprising the infrared-absorbing glass plate according to any one of Claims 1 to 6.

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