Glass article and electronic device

Abstract

A glass article according to the present invention comprises a glass plate that has a hole in a surface and a glass block that fills the hole of the glass plate. The glass plate is constituted by a first glass material, and the glass block is constituted by a second glass material that is different in composition from the first glass material. The glass transition point (Tg1) of the first glass material is higher than the glass transition point (Tg2) of the second glass material. The absolute value (ΔCTE=|CTE1-CTE2|) of the difference between the average linear expansion coefficient (CTE1) of the first glass material and the average linear expansion coefficient (CTE2) of the second glass material is less than 35.8×10-7 / °C.

Description

Glass articles and electronic devices

[0001] The present disclosure relates to glass articles and electronic devices.

[0002] Patent Documents 1 and 2 describe molding methods for integrating first and second glasses that differ in at least one of composition and color tone. In Patent Document 1, the first glass is placed in a mold so as to surround the second glass, and then the first and second glasses are heated to a temperature equal to or higher than their softening points to be integrated. In Patent Document 2, the molten first glass and the solidified second glass are gradually cooled in contact with each other to be integrated. In Patent Documents 1 and 2, the first glass is a black colored glass, and the second glass is a transparent glass.

[0003] Japanese Patent Publication No. 2013-060336 Japanese Patent Publication No. 2012-254898

[0004] The glass article may include a glass plate and a glass block for filling a hole in the glass plate. The glass plate is made of a first glass material, and the glass block is made of a second glass material having a different composition from the first glass material. Conventionally, when the glass plate and the glass block are integrated, the hole in the glass plate may be distorted or may be cracked.

[0005] One aspect of the present disclosure provides a technique for reducing distortion of holes in a glass plate and suppressing the occurrence of cracks.

[0006] A glass article according to one aspect of the present disclosure includes a glass plate having a hole in its surface and a glass block filling the hole in the glass plate. The glass plate is made of a first glass material, and the glass block is made of a second glass material having a different composition from the first glass material. The first glass material has a glass transition point (Tg1) higher than a glass transition point (Tg2) of the second glass material. The absolute value of the difference (ΔCTE=|CTE1-CTE2|) between the average linear expansion coefficient (CTE1) of the first glass material and the average linear expansion coefficient (CTE2) of the second glass material is 35.8×10 －７ / °C.

[0007] According to one aspect of the present disclosure, Tg1 is higher than Tg2, and the glass plate is less likely to deform due to heat than the glass block. Therefore, when the glass plate and the glass block are integrated while being heated, the glass block can be deformed so as to fill the hole in the glass plate while suppressing deformation of the hole, thereby reducing distortion of the hole in the glass plate. In addition, ΔCTE is 35.8 × 10 －７ / °C, the stress caused by the difference in thermal expansion is small, and therefore, the occurrence of cracks can be suppressed.

[0008] FIG. 1(A) is a plan view of a glass article according to one embodiment, and FIG. 1(B) is a cross-sectional view of the glass article according to one embodiment. A cross-sectional view showing an example of visible light transmission through the glass article shown in FIG. 1(B). FIG. 3 is a flowchart showing an example of a method for manufacturing a glass article. FIG. 4(A) is a cross-sectional view showing an example of S101, FIG. 4(B) is a cross-sectional view showing an example of S102, and FIG. 4(C) is a cross-sectional view showing an example of S103. FIG. 5(A) is a plan view of a glass article according to a first modified example, and FIG. 5(B) is a cross-sectional view of the glass article according to the first modified example. FIG. 6(A) is a plan view of a glass article according to a second modified example, FIG. 6(B) is a plan view of a glass article according to a third modified example, and FIG. 6(C) is a plan view of a glass article according to a fourth modified example.

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and their description may be omitted. In the specification, the symbol "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits. The range of values ​​includes the range rounded up or down.

[0010] A glass article 2 according to one embodiment will be described with reference to Figures 1(A) and 1(B). In Figure 1(A), the dotted areas indicate areas made of a first glass material, and the white areas indicate areas made of a second glass material. The first glass material is, for example, black glass, and the second glass material is, for example, transparent glass. In Figures 5(A), 6(A), 6(B), and 6(C), which will be described later, the dotted areas indicate areas made of the first glass material, and the white areas indicate areas made of the second glass material.

[0011] The glass article 2 includes a glass plate 10 and a glass block 20. The glass plate 10 has a hole 13 on a surface 11. The glass block 20 fills the hole 13 in the glass plate 10. The glass plate 10 is made of a first glass material, and the glass block 20 is made of a second glass material having a different composition from the first glass material. The composition of the glass is measured by X-ray fluorescence analysis (XRF). If the glass plate 10 and the glass block 20 have a chemically strengthened layer (described later), the chemically strengthened layer is removed before measuring the composition of the glass.

[0012] The first and second glass materials are not particularly limited, but may be, for example, soda-lime glass, alkali-free glass, chemically strengthened glass, borosilicate glass, or lanthanum borate glass. The first and second glass materials may be partially crystallized. When the first and second glass materials are chemically strengthened glass, Al ２ O ３ 1 mol% to 30 mol%, Na ２ It is preferable that the O content is 1 mol % to 20 mol %.

[0013] The chemically strengthened glass has a chemically strengthened layer on its surface. The chemically strengthened layer is a layer in which compressive stress is introduced by exchanging alkali metal ions (e.g., Na ions) contained in the glass with alkali metal ions (e.g., K ions) having a larger ionic radius at a temperature below the glass transition point. The ion exchange is performed after the glass plate 10 and the glass block 20 are thermally integrated.

[0014] Chemically strengthened glass is expressed in mole percent based on oxides, for example, SiO ２ 45% to 75% Al ２ O ３ 1% to 30%, Li ２ 1% to 20% O, Y ２ O ３ 0% to 5%, ZrO ２ 0% to 5% and TiO ２ and 0% to 1% of one or more of MgO, CaO, SrO, BaO and ZnO in total of 1% to 20%, Na ２ O and K ２ O is 0% to 10% in total, B ２O ３ and P ２ O ５ The total content is 0% to 10%.

[0015] From the viewpoint of recyclability, it is preferable that the absolute value of the difference between the (K content / Na content) of the entire chemically strengthened glass and the (K content / Na content) of the central portion of the chemically strengthened glass is 1% or less of the (K content / Na content) of the central portion of the chemically strengthened glass. Here, the entire chemically strengthened glass includes a chemically strengthened layer, and the central portion of the chemically strengthened glass does not include a chemically strengthened layer. The K content and Na content are in mol%. If the absolute value of the difference is 1% or less, the composition change due to chemical strengthening is small and recyclability is good.

[0016] The first glass material may be black glass, and the second glass material may be ordinary transparent glass. Transparent glass transmits visible light, whereas black glass blocks it by absorbing it. In this embodiment, the black glass is obtained by molding black molten glass, and the glass itself is colored black. In this case, the black glass contains, as a coloring component, metal ions that form a solid solution in the black glass. The black glass contains, as a coloring component, ions of at least one element selected from, for example, Fe, Cr, Mn, Co, Ni, Ti, V, and Cu.

[0017] Black glass is glass that is colored black by, for example, SiO ２ 50% to 75% Al ２ O ３ 0% to 15%, Na ２ O: 0% to 20%, K: ２ O 0% to 20%, MgO 0% to 15%, CaO 0% to 20%, B ２ O ３ 10% to 20%, ΣRO (R is Mg, Ca, Sr, Ba, Zn) 0% to 20%, ZrO ２ 0% to 5%, Fe ２ O ３ 1.0% to 10%, CoO 0% to 1%, SO ３ ΣRO is the total content of MgO, CaO, SrO, BaO and ZnO.

[0018] When coloring the glass itself black, V is used within the range that does not impair the coloring. ２ O ５ , CrO, MnO, CuO, MoO ３ and CeO ２ It may contain at least one selected from the following. ２ O ５ , CrO, MnO, CuO, MoO ３ , CeO ２ The total content of is preferably 0% to 3%, more preferably 0% to 1%, expressed in mass % on the oxide basis.

[0019] When coloring the glass itself black, black glass can be made by using SO as a fining agent within the range that does not impair the coloring. ３ , Sb ２ O ３ , SnO, Cl, and F. ３ , Sb ２ O ３ The total content of SnO, Cl and F is preferably 0% to 1%, and more preferably 0% to 0.5%.

[0020] In this embodiment, the black glass is a block body in which the glass itself is colored black, but it may also be a sintered body obtained by firing a paste containing transparent glass powder and a black pigment. The black pigment is dispersed in the transparent glass without forming a solid solution therein. The black pigment is composed of, for example, a metal or metal compound containing at least one element selected from Fe, Cr, Mn, Co, Ni, Ti, and Cu. The metal compound is, for example, an oxide. The paste may contain additives other than the glass frit and the black pigment, such as ceramic powder.

[0021] When the first glass material is black glass, and the black glass is a sintered body obtained by firing a paste containing a transparent glass powder and a black pigment, Tg1 and CTE1 (described later) may be measured using either a test piece in which the black pigment is dispersed in the transparent glass or a test piece consisting of only the transparent glass. Regardless of the test piece, Tg1 and CTE1 will have approximately the same values. The composition of the transparent glass contained in the black glass can be measured while avoiding the black pigment.

[0022] The glass transition temperature (Tg1) of the first glass material is higher than the glass transition temperature (Tg2) of the second glass material. The glass transition temperatures (Tg1 and Tg2) are measured using a differential thermal analysis (DTA). If the glass plate 10 and the glass block 20 have chemically strengthened layers, the chemically strengthened layers are removed to prepare a test powder for the glass transition temperature.

[0023] If Tg1 is higher than Tg2, the glass plate 10 is less likely to deform due to heat than the glass block 20. Therefore, when the glass plate 10 and the glass block 20 are integrated while being heated, the glass block 20 can be deformed so as to fill the hole 13 in the glass plate 10 while suppressing deformation of the hole 13, and distortion of the hole 13 in the glass plate 10 can be reduced.

[0024] It is preferable that the ratio (Tg1 / Tg2) of the glass transition temperature (Tg1) of the first glass material to the glass transition temperature (Tg2) of the second glass material is 1.04 or more. If the ratio (Tg1 / Tg2) is 1.04 or more, the glass block 20 can be deformed while suppressing deformation of the hole 13 in the glass plate 10. The ratio (Tg1 / Tg2) is more preferably 1.07 or more. The larger the ratio (Tg1 / Tg2), the more preferable it is. However, the ratio (Tg1 / Tg2) may be 1.20 or less.

[0025] The absolute value of the difference between the average linear expansion coefficient (CTE1) of the first glass material and the average linear expansion coefficient (CTE2) of the second glass material (ΔCTE=|CTE1−CTE2|) is 35.8×10 －７ / °C. ΔCTE is preferably less than 35.8 × 10 －７If ΔCTE is less than 23.0×10 / °C, the stress generated by temperature change is small and the glass is less likely to break. －７ / °C or less, and particularly preferably 16.0 × 10 －７ / °C or less. The smaller ΔCTE is, the more preferable, and it may be zero. When ΔCTE is not zero, either CTE1 or CTE2 may be larger.

[0026] The average linear expansion coefficients (CTE1 and CTE2) are the average linear expansion coefficients at 50°C to 350°C. The average linear expansion coefficients are measured using a thermal mechanical analysis (TMA). If the glass plate 10 and the glass block 20 have chemically strengthened layers, the chemically strengthened layers are removed to prepare test specimens. The size of the test specimen is, for example, 5 mm in length, 5 mm in width, and 20 mm in height. If it is difficult to cut out test specimens from a single glass article 2, the test specimens may be prepared by melting materials cut out from multiple glass articles 2.

[0027] The thickness of the glass plate 10 is, for example, 0.2 mm to 5 mm. The thickness of the glass plate 10 is preferably 0.8 mm or less. When the thickness of the glass plate 10 is 0.8 mm or less, ΔCTE is 5.0×10 －７ / °C, the stress generated by temperature changes is small, and the glass is less likely to break. The glass plate 10 is, for example, a flat plate. The glass plate 10 may also be a curved plate. The curved plate only needs to have curved surfaces on at least a portion of the front surface 11 and the back surface 12, and may also have flat surfaces on the other portions.

[0028] Holes 13 are formed in the front surface 11 of the glass plate 10. The method for forming the holes 13 is not particularly limited, but may be, for example, cutting, etching, laser processing, electrical discharge processing, or blasting. Areas where the holes 13 are not to be formed may be protected with a mask. The holes 13 may penetrate the glass plate 10 in the thickness direction and reach the rear surface 12 of the glass plate 10. Note that, although the holes 13 are through holes in this embodiment, they may also be blind holes (i.e., bottomed holes).

[0029] When the surface 11 of the glass plate 10 is viewed from the front, the shape of the surface 11 is, for example, rectangular as shown in Fig. 1(A). The length of one side of the rectangle is, for example, 10 mm to 100 mm. Note that the shape of the surface 11 is not limited to a rectangle and may be, for example, circular as shown in Fig. 6(C).

[0030] When the surface 11 of the glass plate 10 is viewed from the front, the shape of the hole 13 is, for example, circular, as shown in Fig. 1(A). The diameter of the hole 13 is, for example, 10 mm to 100 mm. The shape of the hole 13 is not limited to a circle and may be polygonal. For example, the shape of the hole 13 may be rectangular as shown in Fig. 5(A), cross as shown in Fig. 6(A), star as shown in Fig. 6(B), or the like.

[0031] The combination of the shape of the surface 11 and the shape of the holes 13 is not particularly limited. The number of holes 13 may be one, or may be multiple as shown in FIG. 6(C), or may be three or more. The sizes of the multiple holes 13 may be different as shown in FIG. 6(C), or may be the same. The arrangement of the multiple holes 13 is not particularly limited. Although not shown, the multiple holes 13 may be arranged in a ring shape or in a matrix shape. The arrangement is not particularly limited. For example, the multiple holes 13 may be arranged in a triangular lattice shape.

[0032] As shown in Fig. 2, the glass article 2 may be an optical member that transmits visible light LB. For example, the hole 13 in the glass plate 10 is a through-hole, and the transmittance of the glass plate 10 for visible light LB is 0.1% or less, and the transmittance of the glass block 20 for visible light LB is 50% or more. The glass article 2 adjusts the cross-sectional shape of the visible light LB. The cross-sectional shape of the visible light LB that has passed through the glass article 2 matches the cross-sectional shape of the glass block 20. The glass article 2 is used, for example, in the optical system of an imaging device or an optical sensor.

[0033] The reflectance of visible light LB at the interface between the glass block 20 and the glass plate 10 is preferably 5% or less. The interface between the glass block 20 and the glass plate 10 is the inner surface of the hole 13, which is the interface between the second glass material and the first glass material. The reflectance at this interface depends on the refractive index difference between the second glass material and the first glass material, etc. The smaller the refractive index difference, the lower the reflectance. A test piece for measuring the above reflectance is prepared, for example, by cutting the glass article 2 so as to divide the glass block 20 in two. Visible light LB is irradiated perpendicularly to the interface between the glass block 20 and the glass plate 10 through the glass block 20, and the reflectance is measured.

[0034] If the reflectance of visible light LB at the interface between the glass block 20 and the glass plate 10 is 5% or less, visible light LB propagating inside the glass block 20 that is inclined with respect to the thickness direction of the glass plate 10 can be absorbed inside the glass plate 10. As a result, the generation of stray light can be suppressed. The reflectance is preferably 5% or less, more preferably 3% or less, and even more preferably 1% or less. The smaller the reflectance, the better, and it may even be 0%.

[0035] The transmission wavefront aberration of the visible light LB through the glass block 20 is preferably 10 times or less the wavelength λ of the visible light LB. The wavelength λ of the visible light LB is, for example, 400 nm to 800 nm. The transmission wavefront aberration is caused by variations in the thickness of the glass block 20 or variations in the refractive index of the glass block 20. The variations in the refractive index are caused by variations in residual stress, for example.

[0036] If the transmission wavefront aberration of the visible light LB through the glass block 20 is 10 times or less than λ, the optical characteristics are good. The transmission wavefront aberration is preferably 10 times or less than λ, more preferably 5 times or less than λ, and even more preferably 1 time or less than λ. The smaller the transmission wavefront aberration, the better, and it may even be zero.

[0037] The difference in height between the surface 11 of the glass plate 10 and the surface 21 of the glass block 20 is preferably 10 μm or less. The height of the surface 11 of the glass plate 10 is the average height in a range of 0.5 mm to 1.0 mm from the inner circumferential surface of the hole 13. On the other hand, the height of the surface 21 of the glass block 20 is the average height in the entire range excluding the range within 0.5 mm from the inner circumferential surface of the hole 13.

[0038] If the difference in height between the surface 11 of the glass plate 10 and the surface 21 of the glass block 20 is 10 μm or less, distortion during chemical strengthening can be suppressed. The difference in height is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 1 μm or less. The smaller the difference in height, the better, and it may even be 0 μm.

[0039] The difference in height between the rear surface 12 of the glass plate 10 and the rear surface 22 of the glass block 20 is preferably 10 μm or less. The height of the rear surface 12 of the glass plate 10 is the average height in a range of 0.5 mm to 1.0 mm from the inner circumferential surface of the hole 13. On the other hand, the height of the rear surface 22 of the glass block 20 is the average height in the entire range excluding the range within 0.5 mm from the inner circumferential surface of the hole 13.

[0040] If the difference in height between the rear surface 12 of the glass plate 10 and the rear surface 22 of the glass block 20 is 10 μm or less, distortion during chemical strengthening can be suppressed. The difference in height is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 1 μm or less. The smaller the difference in height, the better, and it may even be 0 μm.

[0041] The glass article 2 is composed of a first glass material and a second glass material different from the first glass material. The uses of the glass article 2 are not particularly limited, and in addition to optical systems, the glass can be applied to various electronic devices that require design, such as the housings of information terminals such as smartphones and monitors such as LCDs, devices incorporating imaging elements such as CCD image sensors or CMOS image sensors or infrared receiving elements for remote controls, and cover glass for devices equipped with displays (display devices).

[0042] An example of a method for manufacturing the glass article 2 will be described with reference to Figures 3 and 4. As shown in Figure 3, the manufacturing method includes, for example, steps S101 to S103. Note that the manufacturing method may include steps not shown. For example, the manufacturing method may include chemically strengthening the glass article 2 after step S103.

[0043] Step S101 includes preparing a glass plate 10 and a glass block 20, as shown in FIG. 4A, for example. The glass plate 10 and the glass block 20 are placed on the lower plate 51 of a press machine 50 with their respective surfaces 11 and 21 facing upward. The glass block 20 is placed inside the hole 13 in the glass plate 10. The glass block 20 is narrower than the hole 13 and taller (thicker) than the depth of the hole 13. The glass block 20 protrudes upward from the hole 13. The volume of the glass block 20 is larger than the volume of the hole 13. Note that the volume of the glass block 20 only needs to be equal to or larger than the volume of the hole 13.

[0044] Step S102 includes, for example, as shown in FIG. 4B , sandwiching and pressing the glass sheet 10 and the glass block 20 between a lower platen 51 and an upper platen 52 of a press 50. The press 50 has a heater (not shown) that heats and integrates the glass sheet 10 and the glass block 20. The heater is provided, for example, on at least one of the lower platen 51 and the upper platen 52. The temperature of the heater is at least higher than Tg2, and more preferably higher than Tg1.

[0045] According to this embodiment, Tg1 is higher than Tg2, and the glass plate 10 is less susceptible to thermal deformation than the glass block 20. Therefore, when the glass plate 10 and the glass block 20 are integrated while being heated, the glass block 20 can be deformed so as to fill the hole 13 in the glass plate 10 while suppressing deformation of the hole 13, thereby reducing distortion of the hole 13 in the glass plate 10.

[0046] Step S103 includes polishing the glass article 2 with a polishing machine 60, as shown in FIG. 4C , for example. The polishing machine 60 has a lower platen 61 and an upper platen 62. The lower platen 61 holds the lower surface of the glass article 2, and the upper platen 62 polishes the upper surface of the glass article 2. This reduces the height difference between the surface 11 of the glass plate 10 and the surface 21 of the glass block 20. The polishing machine 60 may polish both the upper and lower surfaces of the glass article 2 simultaneously. The polishing machine 60 makes the surface 11 of the glass plate 10 and the surface 21 of the glass block 20 flush with each other.

[0047] In Examples 1 to 8 below, glass articles 2 were prepared under the same conditions except for those shown in Table 1, and the presence or absence of cracks and distortion of the hole 13 were confirmed. Examples 2 to 6 and 7 are working examples, and Examples 1, 4, 5, and 8 are comparative examples. In Examples 1 to 8, a glass plate measuring 15 mm in length, 15 mm in width, and 0.8 mm in thickness was prepared as the glass plate 10. A single circular hole with a diameter of 4.5 mm was drilled through the center of the glass plate 10 to form the hole 13. Then, as shown in FIG. 4(A), a glass block 20 was placed in the hole 13 of the glass plate 10, and the glass plate 10 and glass block 20 were sandwiched between the lower platen 51 and upper platen 52 of a press 50 and pressed as shown in FIG. 4(B). The pressing temperature Tp at this time is shown in Table 1. After pressing, the glass article 2 was cooled to room temperature, and the presence or absence of cracks and distortion of the hole 13 were confirmed. The experimental results of Examples 1 to 8, along with the experimental conditions, are shown in Table 1.

[0048]

[0049] In Table 1, a crack evaluation of "good" means that no cracks were observed after pressing, and a crack evaluation of "poor" means that cracks were observed after pressing. Also, in Table 1, a distortion evaluation of "good" means that the change in roundness before and after pressing was 10 times or less, and a distortion evaluation of "poor" means that the change in roundness before and after pressing was more than 10 times. The roundness was measured using a length measuring microscope.

[0050] As shown in Table 1, in Examples 2 to 3 and 6, Tg1 was higher than Tg2, unlike Example 8. Therefore, in Examples 2 to 3 and 6, the change in roundness before and after pressing was 10 times or less, unlike Example 8. Note that in Examples 1, 4 to 5 and 7, cracks occurred during pressing, so the change in roundness could not be measured.

[0051] Furthermore, as shown in Table 1, in Examples 2 to 3, 6 and 8, unlike Example 1, Examples 4 to 5 and Example 7, ΔCTE was 35.8 × 10 －７ / ° C. Therefore, in Examples 2 to 3, 6 and 8, unlike Example 1, Example 4 to Example 5 and Example 7, no cracks were observed after pressing.

[0052] The glass article and electronic device according to the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present disclosure.

[0053] This application claims priority based on Japanese Patent Application No. 2023-169969 filed with the Japan Patent Office on September 29, 2023, the entire contents of which are incorporated herein by reference.

[0054] 2 Glass article 10 Glass plate 11 Surface 13 Hole 20 Glass block

Claims

1. A method for manufacturing a glass block comprising: a glass plate having a hole on a surface; and a glass block filling the hole in the glass plate, wherein the glass plate is made of a first glass material, and the glass block is made of a second glass material having a composition different from that of the first glass material, the glass transition point (Tg1) of the first glass material is higher than the glass transition point (Tg2) of the second glass material, and an absolute value of a difference (ΔCTE=|CTE1-CTE2|) between an average linear expansion coefficient (CTE1) of the first glass material and an average linear expansion coefficient (CTE2) of the second glass material is 35.8×10 －７ / °C or less.

2. The glass article according to claim 1, wherein the ratio (Tg1 / Tg2) of the glass transition point (Tg1) of the first glass material to the glass transition point (Tg2) of the second glass material is 1.04 or more.

3. The absolute value of the difference between the average linear expansion coefficient (CTE1) of the first glass material and the average linear expansion coefficient (CTE2) of the second glass material (ΔCTE=|CTE1-CTE2|) is 23.0×10 －７ 3. The glass article according to claim 1 or 2, wherein the temperature is 0.15 to 1.5° C. or less.

4. The glass article according to claim 1 or 2, wherein the glass plate has a thickness of 0.8 mm or less.

5. The glass article according to claim 1 or 2, wherein the hole is a through hole, the glass plate has a visible light transmittance of 0.1% or less, the glass block has a visible light transmittance of 50% or more, and the glass article is an optical component that transmits the visible light.

6. The glass article according to claim 5, wherein the reflectance of the visible light at the interface between the glass block and the glass plate is 5% or less.

7. The glass article according to claim 5, wherein the transmitted wavefront aberration of the visible light of the glass block is 10 times or less the wavelength of the visible light.

8. The glass article according to claim 1 or 2, wherein the difference in height between the surface of the glass plate and the surface of the glass block is 10 μm or less.

9. The first glass material and the second glass material are each Al ２ O ３ 1 mol% to 30 mol%, Na ２ The glass article according to claim 1 or 2, containing 1 mol % to 20 mol % of O.

10. The glass article according to claim 1 or 2, wherein the glass plate and the glass block each have a chemically strengthened layer.

11. An electronic device comprising the glass article according to claim 1 or 2.

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