Chemically strengthened glass and glass-ceramics and methods for producing the same

Abstract

The present invention relates to chemically strengthened glass and glass-ceramics, and methods for producing them. The present invention aims to provide glass-ceramics that exhibit excellent transparency and chemical strengthening properties and can be produced at relatively low temperatures, as well as chemically strengthened glass exhibiting excellent transparency and strength. The present invention relates to chemically strengthened glass, etc., wherein the chemically strengthened glass has a haze value of 0.5% or less (converted to a thickness of 0.7 mm), a surface compressive stress value of 400 MPa or greater, a compressive stress layer depth of 70 μm or greater, and an ST limit of 18,000 MPa·μm to 30,000 MPa·μm. The chemically strengthened glass is glass-ceramics containing at least one of Li₃PO₄ crystals and Li₄SiO₄ crystals, or a solid solution of either Li₃PO₄ or Li₄SiO₄, or a solid solution of both.

Description

[0001] This application is a divisional application of the Chinese patent application with application date of August 10, 2021 and application number 202180006588.X. Technical Field

[0002] The present invention relates to glass-ceramics and chemically strengthened glass, and methods for producing the same. Background Art

[0003] Chemically strengthened glass is used, for example, as cover glass for portable devices. Chemically strengthened glass is glass that has been exposed to a molten salt containing alkali metal ions, for example. This causes ion exchange between the alkali metal ions in the glass and the alkali metal ions in the molten salt, resulting in a compressive stress layer on the glass surface.

[0004] Glass-ceramics is glass with crystals precipitated within it. Compared to amorphous glass, which lacks crystals, glass-ceramics is harder and less susceptible to damage. Furthermore, chemically strengthened glass-ceramics has a higher CT limit than amorphous glass, making it both resistant to breakage and possessing high strength. However, conventional glass-ceramics often suffer from insufficient transparency compared to amorphous glass.

[0005] Chemically strengthened glass exhibits increased strength as surface compressive stress increases. However, tensile stress (CT) builds up within the glass to offset this compressive stress. Excessively high CT can cause the glass to shatter violently. The critical tensile stress that prevents shattering is called the CT limit.

[0006] Patent Document 1 describes an example in which glass-ceramics is chemically strengthened by subjecting it to an ion exchange treatment.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: International Publication No. 2019 / 022035 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] The glass-ceramics described in Patent Document 1 has excellent transparency and chemical strengthening properties, but sometimes has insufficient transparency. In addition, the high heat treatment temperature required for melting and crystallizing the glass raw materials raises concerns about productivity.

[0012] The present invention provides amorphous glass with excellent transparency and strength and a large thermal expansion coefficient; microcrystalline glass with excellent transparency and chemical strengthening properties, a large thermal expansion coefficient and can be manufactured at a relatively low temperature; and chemically strengthened glass with excellent transparency and strength and a large thermal expansion coefficient.

[0013] Means used to solve problems

[0014] The present invention relates to chemically strengthened glass, wherein the haze value of the chemically strengthened glass converted to a thickness of 0.7 mm is 0.5% or less, the surface compressive stress value of the chemically strengthened glass is 400 MPa or more, the depth of the compressive stress layer of the chemically strengthened glass is 70 μm or more, and the ST limit determined by the following test method is 18,000 MPa·μm to 30,000 MPa·μm. The chemically strengthened glass is microcrystalline glass containing at least one of Li3PO4 crystals and Li4SiO4 crystals, or containing solid solution crystals of either Li3PO4 and Li4SiO4, or a solid solution of both.

[0015] (Test method)

[0016] As test glass plates, a plurality of test glass plates having different tensile stress integral values, i.e., ST values, were prepared by chemically strengthening a 15 mm square glass plate having a thickness of 0.7 mm and a mirror-finished surface under various conditions.

[0017] Using a Vickers testing machine, a diamond indenter with a 90° tip angle is driven into the center of a test glass plate, causing it to fracture. The number of fragments produced is counted as the number of broken pieces. The test is started with a diamond indenter load of 1 kgf. If the glass plate does not crack, the load is increased by 1 kgf at a time. This test is repeated until the glass plate breaks. The number of fragments produced at the initial break is counted.

[0018] The number of broken pieces was plotted against the ST value of the test glass plate, and the ST value when the number of broken pieces reached 10 was read as the ST limit.

[0019] The present invention relates to a microcrystalline glass, which is a microcrystalline glass containing at least one of Li3PO4 crystals and Li4SiO4 crystals, or a solid solution crystal of either Li3PO4 and Li4SiO4 or a solid solution of the two. The haze value of the microcrystalline glass converted to a thickness of 0.7 mm is less than 0.5%, and the tensile stress integral value ST limit is greater than 18000 MPa·μm.

[0020] The present invention relates to a glass-ceramic, wherein the glass-ceramic comprises, in terms of mol % based on oxides:

[0021] 40% to 70% SiO2,

[0022] 10% to 35% Li2O,

[0023] 1% to 15% Al2O3,

[0024] 0.5% to 5% P2O5,

[0025] 0.5% to 5% ZrO2,

[0026] 0-10% B2O3,

[0027] 0-3% Na2O,

[0028] 0~1% K2O, and

[0029] 0~4% SnO2, and

[0030] The total amount of SiO2, Al2O3, P2O5 and B2O3 is 60% to 80%, and

[0031] The ratio of the total amount of Li2O, Na2O and K2O to the total amount of SiO2, Al2O3, P2O5 and B2O3 is 0.20-0.60, and Li3PO4 or Li4SiO4 is used as the main crystal.

[0032] The present invention relates to a method for producing glass-ceramics, wherein a heat treatment is performed to keep the glass at a temperature of 450° C. or higher and 800° C. or lower.

[0033] Measured in mole % on an oxide basis, the glass contains:

[0034] 40% to 70% SiO2,

[0035] 10% to 35% Li2O,

[0036] 1% to 15% Al2O3,

[0037] 0.5% to 5% P2O5,

[0038] 0.5% to 5% ZrO2,

[0039] 0-10% B2O3,

[0040] 0-3% Na2O,

[0041] 0~1% K2O, and

[0042] 0~4% SnO2, and

[0043] The total amount of SiO2, Al2O3, P2O5 and B2O3 is 60% to 80%, and

[0044] The ratio of the total amount of Li2O, Na2O and K2O to the total amount of SiO2, Al2O3, P2O5 and B2O3 is 0.20 to 0.60.

[0045] In addition, the present invention provides a semiconductor support substrate, wherein the semiconductor support substrate comprises the above-mentioned amorphous glass, microcrystalline glass or chemically strengthened glass.

[0046] Effects of the Invention

[0047] The present invention provides amorphous glass with excellent transparency and strength, as well as a large thermal expansion coefficient. Furthermore, the present invention provides glass-ceramics with excellent transparency and chemical strengthening properties, and a large thermal expansion coefficient. Furthermore, the present invention provides chemically strengthened glass with excellent transparency and strength, and a large thermal expansion coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A diagram showing the results of X-ray diffraction of glass-ceramics.

[0049] Figure 2 A diagram showing the stress distribution of chemically strengthened glass.

[0050] Figure 3 This figure shows a cross-sectional FE-SEM image of glass-ceramics. In the figure, white arrows indicate examples of precipitated crystals.

[0051] Figure 4 This is an explanatory diagram of a sample used for measuring the fracture toughness value K1c obtained by the DCDC method.

[0052] Figure 5 The stress expansion coefficient K1 (unit: MPa·m 1 / 2 ) and the crack growth rate v (unit: m / s).

[0053] Figure 6 (A) and Figure 6 (B) shows a supporting glass according to one embodiment of the present invention bonded to a semiconductor substrate, Figure 6 (A) shows a cross-sectional view before bonding, Figure 6 (B) shows a cross-sectional view after bonding.

[0054] Figure 7 A cross-sectional view showing a laminate substrate according to one embodiment of the present invention. DETAILED DESCRIPTION

[0055] In this specification, unless otherwise specified, "to" indicating a numerical range is used to mean that the numerical values ​​described before and after it are included as the lower limit and the upper limit.

[0056] In this specification, "amorphous glass" refers to glass in which no diffraction peak indicating crystals is observed by the powder X-ray diffraction method described later. "Microcrystalline glass" is glass obtained by heat-treating "amorphous glass" to precipitate crystals, and it contains crystals. In this specification, "amorphous glass" and "microcrystalline glass" are sometimes collectively referred to as "glass". In addition, amorphous glass that becomes microcrystalline glass by heat treatment is sometimes referred to as "matrix glass of microcrystalline glass".

[0057] In this specification, for powder X-ray diffraction measurement, for example, CuKα radiation is used to measure 2θ in the range of 10° to 80°. When a diffraction peak appears, the precipitated crystal is identified by the Hanawalt method. In addition, the crystal identified by the peak group containing the peak with the highest integrated intensity among the crystals identified by this method is regarded as the main crystal. As a measuring device, for example, Smart Lab manufactured by Rigaku Corporation of Japan can be used.

[0058] Hereinafter, “chemically strengthened glass” refers to glass subjected to a chemical strengthening treatment, and “glass for chemical strengthening” refers to glass before a chemical strengthening treatment.

[0059] In this specification, unless otherwise specified, the glass composition is expressed in mol % based on oxides, and mol % is simply referred to as "%".

[0060] In this specification, "substantially free of" means that the level is lower than the level of impurities contained in raw materials, etc., that is, it is not intentionally added. Specifically, for example, it is less than 0.1%.

[0061] In this specification, "stress distribution" refers to the distribution of compressive stress values ​​expressed as a variable of depth from the glass surface. In the stress distribution, tensile stress is expressed as negative compressive stress.

[0062] Compressive stress (CS) can be measured by thinning a cross section of glass and analyzing the thinned sample using a birefringence imaging system. A birefringence imaging system, such as the Abrio-IM birefringence imaging system manufactured by CRi, uses a polarizing microscope and a liquid crystal compensator to measure the magnitude of retardation caused by stress.

[0063] Alternatively, scattered light photoelasticity can be used for measurement. In this method, light is incident on the glass surface and the polarized scattered light is analyzed to measure CS. An example of a stress measuring instrument using scattered light photoelasticity is the SLP-2000 Scattered Light Photoelasticity Stress Meter manufactured by Orihara Seisakusho.

[0064] In this specification, the "depth of compressive stress layer (DOL)" is the depth at which the compressive stress value is zero. Hereinafter, the surface compressive stress value is sometimes described as CS0, and the compressive stress value at a depth of 50 μm is sometimes described as CS 50 In addition, "internal tensile stress (CT)" refers to the tensile stress value at a depth of 1 / 2 the plate thickness t.

[0065] The "tensile stress integral value (ST value)" is the area integral of tensile stress (negative compressive stress) relative to the sample depth from the DOL to a depth of half the thickness t. In chemically strengthened glass, when the ST value in the glass exceeds a certain threshold, the number of fractures increases dramatically during fracture. This threshold is called the "ST limit."

[0066] In this specification, "ST limit" is measured by the following method.

[0067] (ST limit measurement method)

[0068] As the test glass plates, a plurality of test glass plates having different ST values ​​were prepared by subjecting a 15 mm square, 0.7 mm thick glass plate having a mirror-finished surface to chemical strengthening treatment under various conditions.

[0069] Using a Vickers testing machine, a diamond indenter with a 90° tip angle is driven into the center of a test glass plate, causing it to fracture. The number of fragments produced is counted as the number of broken pieces. The test is started with a diamond indenter load of 1 kgf. If the glass plate does not crack, the load is increased by 1 kgf at a time. This test is repeated until the glass plate breaks. The number of fragments produced at the initial break is counted.

[0070] The number of broken pieces was plotted against the ST value of the test glass plate, and the ST value when the number of broken pieces reached 10 was read as the ST limit.

[0071] In this specification, "light transmittance" refers to the average transmittance of light with a wavelength of 380 nm to 780 nm. In addition, "haze value" is measured using a halogen lamp C light source in accordance with JIS K7136:2000.

[0072] In this specification, the "fracture toughness value Kc" is a value obtained by the IF method specified in JIS R1607:2015.

[0073] In this specification, the "fracture toughness value K1c" is measured by the DCDC method [reference: MY He, MR Turner and A.G. Evans, Acta Metall. Mater. 43 (1995) 3453.]. Specifically, Figure 4 The sample of the shape shown and SHIMADZU Autograph AGS-X5KN were measured as Figure 5 The stress expansion coefficient K1 (unit: MPa·m 1 / 2 ) and the crack growth rate v (unit: m / s) are plotted in the K1-v curve. The data of Region III obtained are regressed and extrapolated using a first-order equation, and the stress expansion coefficient K1 at 0.1 m / s is taken as the fracture toughness value K1c.

[0074] In this specification, the term "semiconductor" may refer not only to a semiconductor wafer or semiconductor chip made of silicon or the like but also to a composite body including a chip, a wiring layer, and an encapsulating resin.

[0075] In this specification, the crack initiation load (CIL) refers to the indentation load of the Vickers indenter at which the crack initiation rate is 50% when an indentation is made on a mirror-finished surface having a thickness of 0.7 mm or greater using a Vickers indenter having a tip angle of 136°.

[0076] (CIL Measurement Method)

[0077] Prepare a plate of glass with a thickness of 0.7 mm and mirror-polished on both sides. Use a Vickers hardness tester to press the Vickers indenter for 15 seconds, then remove the Vickers indenter and observe how many cracks are generated from the corners of the indentation after 15 seconds. Measure the indentation load of the Vickers indenter at 10 gf, 25 gf, 50 gf, 100 gf, 200 gf, 300 gf, and 500 gf on 10 pieces of glass, and calculate the average number of cracks generated at each load. Use the S-type function to regress the relationship between the load and the number of cracks, and take the load with 2 cracks as CIL (gf). It should be noted that the atmospheric conditions for the measurement are an air temperature of 25°C and a dew point of -40°C.

[0078] Chemically strengthened glass

[0079] The chemically strengthened glass of the present invention (hereinafter also referred to as the present strengthened glass) is typically a plate-shaped glass article, which may be flat or curved. Furthermore, it may have portions of varying thicknesses. Furthermore, the chemically strengthened glass of the present invention is a glass-ceramic containing at least one of Li3PO4 crystals and Li4SiO4 crystals, or a solid solution of either Li3PO4 or Li4SiO4, or a solid solution of both. Glass-ceramics containing at least one of Li3PO4 crystals and Li4SiO4 crystals, or a solid solution of either Li3PO4 or Li4SiO4, or a solid solution of both will be described later.

[0080] When the chemically strengthened glass is in the form of a plate, its thickness (t) is preferably 3 mm or less, more preferably 2 mm or less, 1.6 mm or less, 1.1 mm or less, 0.9 mm or less, 0.8 mm or less, and 0.7 mm or less, as follows. Furthermore, to obtain sufficient strength through chemical strengthening, the thickness (t) is preferably 0.3 mm or more, more preferably 0.4 mm or more, and even more preferably 0.5 mm or more.

[0081] The haze value of the present strengthened glass converted to a thickness of 0.7 mm is preferably 0.5% or less. The haze value and light transmittance of the present chemically strengthened glass are substantially the same as those of the glass-ceramics before chemical strengthening, and therefore are described in the section of the glass-ceramics.

[0082] When the surface compressive stress value (CSO) of the present tempered glass is 400 MPa or higher, it is less likely to break due to deformation such as warping, and is therefore preferred. The CSO is more preferably 500 MPa or higher, and even more preferably 600 MPa or higher. The higher the CSO, the higher the strength. However, if the CSO is too high, it may cause severe fracture in the event of breakage. Therefore, the CSO is preferably 1200 MPa or lower, and more preferably 1000 MPa or lower.

[0083] When the DOL of this tempered glass is 70 μm or greater, it is less likely to break even if surface damage occurs, so it is preferred. A DOL of 80 μm or greater is more preferred, 90 μm or greater is even more preferred, and 100 μm or greater is particularly preferred. The larger the DOL, the less likely it is to break even if damage occurs. However, in chemically tempered glass, tensile stresses corresponding to the compressive stresses formed near the surface are generated internally, so it cannot be increased extremely. For a thickness of t, the DOL is preferably less than t / 4, more preferably less than t / 5. To shorten the time required for chemical strengthening, the DOL is preferably less than 200 μm, more preferably less than 180 μm.

[0084] When the CT of the present tempered glass is 110 MPa or less, the scattering of fragments when the chemically strengthened glass breaks is suppressed, which is preferable. The CT is more preferably 100 MPa or less, and even more preferably 90 MPa or less. On the other hand, decreasing the CT decreases the surface compressive stress, making it difficult to achieve sufficient strength. Therefore, the CT is preferably 50 MPa or more, more preferably 55 MPa or more, and even more preferably 60 MPa or more.

[0085] To improve drop resistance, the ST value of the present tempered glass is preferably 18,000 MPa·μm or higher, more preferably 20,000 MPa·μm or higher, even more preferably 22,000 MPa·μm or higher, and most preferably 24,000 MPa·μm or higher. On the other hand, if the ST value is too high, glass fragments will scatter upon breakage. Therefore, the ST value is preferably 30,000 MPa·μm or lower, more preferably 29,000 MPa·μm or lower, even more preferably 28,000 MPa·μm or lower, and most preferably 27,000 MPa·μm or lower.

[0086] The basic composition of the tempered glass preferably contains, in terms of mol% based on oxides:

[0087] 40% to 70% SiO2,

[0088] 10% to 35% Li2O, and

[0089] 1% to 15% Al2O3.

[0090] Furthermore, the basic composition of the present tempered glass more preferably contains, in terms of mol% based on oxides:

[0091] 40% to 70% SiO2,

[0092] 10% to 35% Li2O,

[0093] 1% to 15% Al2O3,

[0094] 0.5% to 5% P2O5,

[0095] 0.5% to 5% ZrO2,

[0096] 0-10% B2O3,

[0097] 0-3% Na2O,

[0098] 0~1% K2O, and

[0099] 0~4% SnO2, and

[0100] The total amount of SiO2, Al2O3, P2O5 and B2O3 is 60% to 80%.

[0101] Alternatively, the basic composition of the present tempered glass more preferably contains, in terms of mol% based on oxides:

[0102] 50% to 70% SiO2,

[0103] 15% to 30% Li2O,

[0104] 1% to 10% Al2O3,

[0105] 0.5% to 5% P2O5,

[0106] 0.5% to 8% ZrO2,

[0107] 0.1% to 10% MgO,

[0108] 0-5% Y2O3,

[0109] 0-10% B2O3,

[0110] 0-3% Na2O,

[0111] 0~1% K2O, and

[0112] 0~2% SnO2.

[0113] Here, the "basic composition of chemically strengthened glass" refers to the composition of the glass-ceramics before chemical strengthening. This composition will be described later. The composition of this strengthened glass is generally similar to that of the glass-ceramics before strengthening, except when subjected to extreme ion exchange treatment. In particular, except when subjected to extreme ion exchange treatment, the composition of the deepest portion from the glass surface is identical to that of the glass-ceramics before strengthening.

[0114] Except the semiconductor support substrate described later, this tempered glass is also useful as the protection glass used in the electronic equipment such as mobile devices such as mobile phones and smart phones.In addition, it is also useful for the protection glass of the electronic equipment such as television sets, computers, touch panels that are not easy to carry for the purpose, the wall surface (full screen display) of the buildings such as elevator walls, houses or buildings.In addition, it is also useful for the interior decoration of the building materials, desktops, cars or airplanes etc. of window glass etc. or their protection glass and the housing with curved surface shape etc. In addition, the glass-ceramics before strengthening and the amorphous glass before crystallization are also useful as semiconductor support substrate purposes.

[0115] This semiconductor support substrate is used in the field of semiconductor packaging. In the field of semiconductor packaging, wafer-level packaging (WLP) and panel-level packaging (PLP) technologies are attracting attention in manufacturing (see Asahi Glass Research Report 67 (2017)). For example, these technologies involve placing a silicon chip on a glass substrate and sealing it with a molding resin.

[0116] In this case, the supporting substrate is sometimes peeled off midway through the manufacturing process. Glass substrates are widely used as supporting substrates. Because glass substrates are transparent, they can be peeled off by irradiating them with a laser beam. Glass substrates used as supporting substrates are required to minimize warping by matching the thermal expansion of the semiconductor. Furthermore, they must be resistant to breakage during the packaging process and prevent fragments from scattering if they do break.

[0117] <Glass-ceramic>

[0118] The present glass-ceramics preferably contains at least one of Li3PO4 crystals and Li4SiO4 crystals. By using these crystals as the main crystals, the light transmittance is improved and the haze is reduced.

[0119] The present glass-ceramics may contain both Li3PO4 crystals and Li4SiO4 crystals. Either one may be contained as the main crystal. A solid solution crystal of Li3PO4 and Li4SiO4 may be used as the main crystal. Alternatively, a solid solution crystal of either Li3PO4 or Li4SiO4 may be used as the main crystal.

[0120] It should be noted that Li2SiO3 crystals do not have excellent chemical resistance, so it is preferable not to contain Li2SiO3 crystals.

[0121] Since the crystal structures of Li3PO4 crystals and Li4SiO4 crystals are similar, it is sometimes difficult to distinguish them by powder X-ray diffraction measurement. That is, when measuring powder X-ray diffraction, diffraction peaks appear near 2θ=16.9°, 22.3°, 23.1°, and 33.9°. Due to the fact that there are also cases where the amount of crystals is small or orientation occurs, it is sometimes impossible to confirm peaks with low intensity or peaks of specific crystal planes. In addition, when the two crystals are in solid solution, the peak position of 2θ sometimes shifts by about 1°.

[0122] When X-ray diffraction is measured within the range of 2θ=10° to 80°, the strongest diffraction peak of the present glass-ceramics preferably appears at 22.3°±0.2° or 23.1°±0.2°.

[0123] To improve mechanical strength, the crystallization rate of the present glass-ceramics is preferably 5% or higher, more preferably 10% or higher, even more preferably 15% or higher, and particularly preferably 20% or higher. To improve transparency, the crystallization rate is preferably 70% or lower, more preferably 60% or lower, and even more preferably 50% or lower. A lower crystallization rate is also advantageous for ease of heat bending and other molding processes.

[0124] To improve strength, the average particle size of the precipitated crystals of the present glass-ceramics is preferably 5 nm or more, particularly preferably 10 nm or more. To improve transparency, the average particle size is preferably 80 nm or less, more preferably 60 nm or less, further preferably 50 nm or less, particularly preferably 40 nm or less, and most preferably 30 nm or less. The average particle size of the precipitated crystals can be determined from transmission electron microscopy (TEM) images or FE-SEM images.

[0125] When the glass-ceramics is in plate form, the thickness (t) is preferably 3 mm or less, more preferably 2 mm or less, 1.6 mm or less, 1.1 mm or less, 0.9 mm or less, 0.8 mm or less, and 0.7 mm or less. Furthermore, in order to obtain sufficient strength due to chemical strengthening treatment, the thickness (t) is preferably 0.3 mm or more, more preferably 0.4 mm or more, and even more preferably 0.5 mm or more.

[0126] At a thickness of 0.7 mm, this glass-ceramic has a light transmittance of 85% or higher. This makes it easy to see images on a portable display when used as cover glass. The light transmittance is preferably 88% or higher, and more preferably 90% or higher. While higher light transmittance is preferred, it is typically 91% or lower. At a thickness of 0.7 mm, a light transmittance of 90% is comparable to that of ordinary amorphous glass.

[0127] It should be noted that if the actual thickness is not 0.7 mm, the light transmittance at 0.7 mm can be calculated based on the measured value using the Lambert-Beer law. Furthermore, if the plate thickness t is greater than 0.7 mm, the plate thickness can be adjusted to 0.7 mm by grinding, etching, etc., and then measured.

[0128] Furthermore, at a thickness of 0.7 mm, the haze value is 0.5% or less, preferably 0.3% or less, more preferably 0.2% or less, even more preferably 0.15% or less, particularly preferably 0.1% or less, most preferably 0.08% or less, and extremely preferably 0.05% or less. The lower the haze value, the better, but it is typically 0.01% or more. At a thickness of 0.7 mm, a haze value of 0.02% is comparable to that of ordinary amorphous glass.

[0129] It should be noted that, when the total visible light transmittance of a glass-ceramic with a thickness of t [mm] is 100 × T [%] and the haze value is 100 × H [%], by citing the Lambert-Beer law and using the constant α, it can be expressed as T = (1-R) 2 × exp(-αt). Using this constant α, dH / dt∝exp(-αt)×(1-H) is obtained.

[0130] That is, since it is considered that the haze value increases in proportion to the internal linear transmittance as the plate thickness increases, the haze value H in the case of 0.7 mm is 0.7 It can be calculated using the following formula.

[0131]

[0132] When the plate thickness t is larger than 0.7 mm, the plate thickness may be adjusted to 0.7 mm by grinding, etching, or the like and then measured.

[0133] The ST limit of this glass-ceramic is preferably 18,000 MPa·μm or greater. To improve drop resistance through chemical strengthening, the ST limit is more preferably 19,000 MPa·μm or greater, and even more preferably 20,000 MPa·μm or greater. Because this glass-ceramic has a large ST limit, chemical strengthening makes it high-strength and resistant to breakage. A larger ST limit is more preferred, but is typically 30,000 MPa·μm or less.

[0134] The present glass-ceramics is obtained by crystallizing amorphous glass, which will be described later, by heating it.

[0135] The present glass-ceramics preferably contains, in terms of mol% based on oxides:

[0136] 40% to 70% SiO2,

[0137] 10% to 35% Li2O,

[0138] 1% to 15% Al2O3,

[0139] 0.5% to 5% P2O5,

[0140] 0.5% to 5% ZrO2,

[0141] 0-10% B2O3,

[0142] 0-3% Na2O,

[0143] 0~1% K2O, and

[0144] 0 to 4% SnO 2. In this specification, the glass-ceramics having the above composition is also referred to as "the present glass-ceramics A."

[0145] Alternatively, the present glass-ceramics preferably contains, in terms of mol% based on oxides:

[0146] 50% to 70% SiO2,

[0147] 15% to 30% Li2O,

[0148] 1% to 10% Al2O3,

[0149] 0.5% to 5% P2O5,

[0150] 0.5% to 8% ZrO2,

[0151] 0.1% to 10% MgO,

[0152] 0-5% Y2O3,

[0153] 0-10% B2O3,

[0154] 0-3% Na2O,

[0155] 0~1% K2O, and

[0156] 0 to 2% SnO 2. In this specification, the glass-ceramics having the above composition is also referred to as "the present glass-ceramics B."

[0157] In addition, in terms of molar percentage based on oxides, the total amount of SiO2, Al2O3, P2O5 and B2O3 in the present glass-ceramics is preferably 60% to 80%. SiO2, Al2O3, P2O5 and B2O3 are network-forming components of the glass (hereinafter also referred to as NWF). Since the total amount of these NWFs is large, the strength of the glass is improved. This increases the fracture toughness value of the glass-ceramics, so the total amount of NWF is preferably 60% or more, more preferably 63% or more, and particularly preferably 65% ​​or more. However, glass with too much NWF becomes difficult to manufacture due to increased melting temperature, so it is preferably 80% or less, more preferably 75%, and more preferably 70% or less.

[0158] The ratio of the total amount of Li2O, Na2O and K2O in the present glass-ceramics to the total amount of NWF, that is, SiO2, Al2O3, P2O5 and B2O3 is preferably 0.20 to 0.60. For use as a semiconductor support substrate, if the ratio of the content of Al2O3 to Li2O, Al2O3 / Li2O, is 0.0029 to 0.0075 relative to the total amount of NWF, it is possible to increase the Young's modulus while maintaining the thermal expansion coefficient suitable as a support substrate for semiconductor packages with a large resin component, and to reduce warping during the packaging process. As a lower limit, it is preferably 0.0031 or more, more preferably 0.0032 or more, and as an upper limit, it is preferably 0.0064 or less, more preferably 0.0051 or less. As a component for increasing the Young's modulus, Al2O3 is the most effective, but in addition to these, MgO, ZrO2, Y2O3, Ga2O3, BeO, TiO2, and Ta2O5 can also be listed.

[0159] Li2O, Na2O, and KO are network-modifying components. Reducing their ratio relative to the NWF increases the gaps in the network, thereby improving impact resistance. Therefore, the ratio of the total amount of Li2O, Na2O, and KO to the total amount of NWF (i.e., SiO2, Al2O3, P2O5, and B2O3) is preferably 0.60 or less, more preferably 0.55 or less, and particularly preferably 0.50 or less. Furthermore, these components are essential for chemical strengthening. Therefore, to enhance chemical strengthening properties, the ratio of the total amount of Li2O, Na2O, and KO to the total amount of NWF (i.e., SiO2, Al2O3, P2O5, and B2O3) is preferably 0.20 or greater, more preferably 0.25 or greater, and particularly preferably 0.30 or greater.

[0160] Hereinafter, the glass composition will be described.

[0161] In this amorphous glass, SiO2 is a component that forms the network structure of the glass. Furthermore, SiO2 improves chemical durability, and the SiO2 content is preferably 40% or greater. The SiO2 content is more preferably 45% or greater, further preferably 50% or greater, particularly preferably 52% or greater, and extremely preferably 54% or greater. On the other hand, to improve meltability, the SiO2 content is preferably 70% or less, more preferably 68% or less, further preferably 66% or less, and particularly preferably 64% or less.

[0162] Al2O3 is an essential component for increasing the surface compressive stress generated by chemical strengthening. The Al2O3 content is preferably 1% or more, more preferably 2% or more, further preferably 3% or more, 5% or more, 5.5% or more, 6% or more, particularly preferably 6.5% or more, and most preferably 7% or more. On the other hand, to prevent the devitrification temperature of the glass from becoming too high, the Al2O3 content is preferably 15% or less, more preferably 12% or less, further preferably 10% or less, particularly preferably 9% or less, and most preferably 8% or less.

[0163] Li2O is a component that generates surface compressive stress through ion exchange and is essential for the main crystal. The Li2O content is preferably 10% or greater, more preferably 14% or greater, even more preferably 15% or greater, further preferably 18% or greater, particularly preferably 20% or greater, and most preferably 22% or greater. On the other hand, to stabilize the glass, the Li2O content is preferably 35% or less, more preferably 32% or less, further preferably 30% or less, particularly preferably 28% or less, and most preferably 26% or less.

[0164] Na2O is a component that improves the meltability of glass. While not essential, if present, its content is preferably 0.5% or greater, more preferably 1% or greater, and particularly preferably 2% or greater. Excessive Na2O content makes crystal precipitation difficult or reduces chemical strengthening properties. Therefore, the Na2O content is preferably 3% or less, more preferably 2.5% or less, even more preferably 2% or less, and particularly preferably 1.5% or less.

[0165] Like Na2O, K2O is a component that lowers the melting temperature of glass, and may be contained. When K2O is contained, the content is preferably 0.5% or more, more preferably 0.8% or more, and even more preferably 1% or more. Excessive K2O content reduces chemical strengthening properties and chemical durability, so the K2O content is preferably 1% or less, more preferably 0.8% or less, even more preferably 0.6% or less, particularly preferably 0.5% or less, and most preferably 0.4% or less.

[0166] In order to improve the solubility of glass raw materials, the total content of Na2O and K2O (Na2O+K2O) is preferably 1% or more, more preferably 2% or more.

[0167] Furthermore, when the ratio of the K2O content to the total content of Li2O, Na2O, and K2O (hereinafter referred to as R2O) K2O / R2O is 0.2 or less, chemical strengthening properties can be improved and chemical durability can be improved, which is preferred. K2O / R2O is more preferably 0.15 or less, and even more preferably 0.10 or less.

[0168] It should be noted that R2O is preferably 10% or more, more preferably 15% or more, and even more preferably 20% or more. Furthermore, R2O is preferably 29% or less, and more preferably 26% or less.

[0169] P2O5 is an essential component of Li3PO4 crystals. To promote crystallization, the P2O5 content is preferably 0.5% or greater, more preferably 1% or greater, even more preferably 1.5% or greater, particularly preferably 2% or greater, and extremely preferably 2.5% or greater. On the other hand, excessive P2O5 content can lead to phase separation during melting and significantly reduce acid resistance. Therefore, the P2O5 content is preferably 5% or less, more preferably 4.8% or less, even more preferably 4.5% or less, and particularly preferably 4.2% or less.

[0170] ZrO2 is a component that improves mechanical strength and chemical durability. To significantly improve CS, it is preferably contained. The ZrO2 content is preferably 0.5% or more, more preferably 1% or more, even more preferably 1.5% or more, particularly preferably 2% or more, and most preferably 2.5% or more. On the other hand, to suppress devitrification during melting, the ZrO2 content is preferably 8% or less, more preferably 7.5% or less, even more preferably 7% or less, and particularly preferably 6% or less. Excessive ZrO2 content increases the devitrification temperature and reduces viscosity. To suppress deterioration in formability due to this reduced viscosity, when the forming viscosity is low, the ZrO2 content is preferably 5% or less, more preferably 4.5% or less, and even more preferably 3.5% or less.

[0171] Furthermore, to improve chemical durability, the ZrO2 / R2O ratio is preferably 0.02 or greater, more preferably 0.03 or greater, further preferably 0.04 or greater, particularly preferably 0.1 or greater, and most preferably 0.15 or greater. To improve transparency after crystallization, the ZrO2 / R2O ratio is preferably 0.6 or less, more preferably 0.5 or less, further preferably 0.4 or less, and particularly preferably 0.3 or less.

[0172] MgO stabilizes glass and improves mechanical strength and chemical resistance. Therefore, it is preferable to include MgO when the Al₂O₃ content is relatively low. The MgO content is preferably 1% or higher, more preferably 2% or higher, even more preferably 3% or higher, and particularly preferably 4% or higher. On the other hand, excessive addition of MgO reduces the viscosity of the glass, making devitrification and phase separation more likely to occur. Therefore, the MgO content is preferably 10% or lower, more preferably 9% or lower, even more preferably 8% or lower, and particularly preferably 7% or lower.

[0173] TiO2 is a component that promotes crystallization and may be contained. TiO2 is not essential, but when contained, the TiO2 content is preferably 0.2% or greater, more preferably 0.5% or greater. On the other hand, to suppress devitrification during melting, the TiO2 content is preferably 4% or less, more preferably 2% or less, and even more preferably 1% or less.

[0174] SnO2 promotes crystal nucleation and may be contained. SnO2 is not essential, but when it is present, the SnO2 content is preferably 0.5% or more, more preferably 1% or more, even more preferably 1.5% or more, and particularly preferably 2% or more. On the other hand, to suppress devitrification during melting, the SnO2 content is preferably 4% or less, more preferably 3.5% or less, even more preferably 3% or less, and particularly preferably 2.5% or less.

[0175] Y2O3 is a component that has the effect of reducing the scattering of fragments when chemically strengthened glass breaks, and may be contained. The Y2O3 content is preferably 1% or more, more preferably 1.5% or more, even more preferably 2% or more, particularly preferably 2.5% or more, and extremely preferably 3% or more. On the other hand, to suppress devitrification during melting, the Y2O3 content is preferably 5% or less, more preferably 4% or less.

[0176] B2O3 is a component that improves the chipping resistance and meltability of chemically strengthened glass or chemically tempered glass, and may be contained. To improve meltability, when B2O3 is contained, the B2O3 content is preferably 0.5% or greater, more preferably 1% or greater, and even more preferably 2% or greater. On the other hand, excessive B2O3 content can cause striae during melting or facilitate phase separation, which can reduce the quality of the chemically tempered glass. Therefore, the B2O3 content is preferably 10% or less. The B2O3 content is more preferably 8% or less, even more preferably 6% or less, and particularly preferably 4% or less.

[0177] BaO, SrO, MgO, CaO, and ZnO are all components that improve the meltability of glass and may be contained. When these components are contained, the combined content of BaO, SrO, MgO, CaO, and ZnO (hereinafter referred to as BaO+SrO+MgO+CaO+ZnO) is preferably 0.5% or greater, more preferably 1% or greater, even more preferably 1.5% or greater, and particularly preferably 2% or greater. On the other hand, to reduce the ion exchange rate, the content of BaO+SrO+MgO+CaO+ZnO is preferably 8% or less, more preferably 6% or less, even more preferably 5% or less, and particularly preferably 4% or less.

[0178] Among them, in order to increase the refractive index of the residual glass and approach the precipitated crystal phase to increase the light transmittance of the microcrystalline glass and reduce the haze value, BaO, SrO, and ZnO may be contained. In this case, the total content of BaO, SrO, and ZnO (hereinafter referred to as BaO+SrO+ZnO) is preferably 0.3% or more, more preferably 0.5% or more, further preferably 0.7% or more, and particularly preferably 1% or more. On the other hand, these components sometimes reduce the ion exchange rate. In order to improve the chemical strengthening properties, BaO+SrO+ZnO is preferably 2.5% or less, more preferably 2% or less, further preferably 1.7% or less, and particularly preferably 1.5% or less.

[0179] La2O3, Nb2O5, and Ta2O5 are all components that prevent fragments from scattering when chemically strengthened glass breaks. They may be included to increase the refractive index. When these components are included, the combined content of La2O3, Nb2O5, and Ta2O5 (hereinafter referred to as La2O3+Nb2O5+Ta2O5) is preferably 0.5% or greater, more preferably 1% or greater, even more preferably 1.5% or greater, and particularly preferably 2% or greater. Furthermore, to prevent devitrification of the glass during melting, the combined content of La2O3+Nb2O5+Ta2O5 is preferably 4% or less, more preferably 3% or less, even more preferably 2% or less, and particularly preferably 1% or less.

[0180] CeO2 may also be included. CeO2 may suppress coloration by oxidizing the glass. When CeO2 is included, the CeO2 content is preferably 0.03% or more, more preferably 0.05% or more, and even more preferably 0.07% or more. To improve transparency, the CeO2 content is preferably 1.5% or less, more preferably 1.0% or less.

[0181] When tempered glass is colored for use, coloring components may be added within a range that does not hinder the desired chemical strengthening properties. Examples of coloring components include Co3O4, MnO2, Fe2O3, NiO, CuO, Cr2O3, V2O5, Bi2O3, SeO2, Er2O3, and Nd2O3.

[0182] The content of the coloring components is preferably within a range of 1% or less in total. In order to further increase the visible light transmittance of the glass, it is preferred that these components are substantially not contained.

[0183] To improve weather resistance to ultraviolet light, HfO2, Nb2O5, and Ti2O3 may be added. When added to improve weather resistance to ultraviolet light, the combined content of HfO2, Nb2O5, and Ti2O3 is preferably 1% or less, more preferably 0.5% or less, and even more preferably 0.1% or less to minimize the effects on other properties.

[0184] In addition, SO₃, chlorides, and fluorides may be appropriately contained as clarifiers during glass melting. Excessive addition of the total content of components functioning as clarifiers can affect strengthening properties and crystallization behavior. Therefore, the total content, calculated as % by mass based on oxides, is preferably 2% or less, more preferably 1% or less, and even more preferably 0.5% or less. While there is no particular lower limit, typically, the total content, calculated as % by mass based on oxides, is preferably 0.05% or more.

[0185] When SO₃ is used as a clarifier, if the SO₃ content is too low, no effect is observed. Therefore, the SO₃ content, calculated as mass % based on oxides, is preferably 0.01% or more, more preferably 0.05% or more, and even more preferably 0.1% or more. Furthermore, when SO₃ is used as a clarifier, the SO₃ content, calculated as mass % based on oxides, is preferably 1% or less, more preferably 0.8% or less, and even more preferably 0.6% or less.

[0186] When Cl is used as a fining agent, excessive addition of Cl can affect physical properties such as strengthening characteristics. Therefore, the Cl content, expressed as mass % based on oxides, is preferably 1% or less, more preferably 0.8% or less, and even more preferably 0.6% or less. Furthermore, when Cl is used as a fining agent, if the Cl content is too low, no effect is observed. Therefore, the Cl content, expressed as mass % based on oxides, is preferably 0.05% or more, more preferably 0.1% or more, and even more preferably 0.2% or more.

[0187] When SnO2 is used as a clarifier, excessive addition of SnO2 affects crystallization behavior. Therefore, the SnO2 content, calculated as mass % based on the oxide, is preferably 1% or less, more preferably 0.5% or less, and even more preferably 0.3% or less. Furthermore, when SnO2 is used as a clarifier, if the SnO2 content is too low, no effect is observed. Therefore, the SnO2 content, calculated as mass % based on the oxide, is preferably 0.02% or more, more preferably 0.05% or more, and even more preferably 0.1% or more.

[0188] It is preferable that As2O3 is not contained. When Sb2O3 is contained, it is preferably 0.3% or less, more preferably 0.1% or less, and most preferably not contained.

[0189] The fracture toughness value of the present glass-ceramics is high, and even if a large compressive stress is formed by chemical strengthening, it is not easy to cause severe fracture. When the fracture toughness value of the present glass-ceramics is preferably 0.81 MPa·m 1 / 2 More preferably, 0.83 MPa·m 1 / 2 More preferably, 0.85 MPa·m 1 / 2 When the above values ​​are met, glass with high impact resistance can be obtained. The upper limit of the fracture toughness value of the present glass-ceramics is not particularly limited, but is typically 1.5 MPa·m 1 / 2 the following.

[0190] In order to suppress the warping during chemical strengthening treatment, the Young's modulus of the present glass-ceramics is preferably 80 GPa or more, more preferably 85 GPa or more, further preferably 90 GPa or more, and particularly preferably 95 GPa or more. The present glass-ceramics is sometimes used after grinding. In order to easily grind, the Young's modulus is preferably 130 GPa or less, more preferably 120 GPa or less, and further preferably 110 GPa or less.

[0191] In addition, if the Young's modulus of the amorphous glass is 80 GPa or more, warping can be suppressed even in the state of amorphous glass, and therefore it is suitable for use as a semiconductor support substrate. Preferably it is 85 GPa or more, more preferably 90 GPa or more, and further preferably 95 GPa or more. In order to facilitate grinding, the Young's modulus is preferably 130 GPa or less, more preferably 120 GPa or less, and further preferably 110 GPa or less.

[0192] From the perspective of suppressing the generation of cracks during dropping, the indentation load value (CIL) of the present glass-ceramics with 2 cracks is preferably 50 gf or more, more preferably 100 gf or more, further preferably 150 gf or more, and most preferably 200 gf or more.

[0193] Amorphous glass

[0194] The present glass-ceramics can be obtained by heat-treating the amorphous glass (the amorphous glass of the present invention) described below. The composition of the amorphous glass of the present invention is the same as the composition of the present glass-ceramics described above.

[0195] The amorphous glass of the present invention (hereinafter also referred to as the present amorphous glass) preferably contains 40% to 70% of SiO2, 10% to 35% of Li2O and 1% to 15% of Al2O3, in terms of mol% based on oxides.

[0196] As the preferred composition of the present amorphous glass, for example, the following composition can be listed: calculated on a molar basis on the oxide basis, it contains 40% to 70% SiO2, 10% to 35% Li2O, 1% to 15% Al2O3, 0.5% to 5% P2O5, 0.5% to 5% ZrO2, 0 to 10% B2O3, 0 to 3% Na2O, 0 to 1% K2O and 0 to 4% SnO2.

[0197] Alternatively, as a preferred composition of the present amorphous glass, for example, the following composition can be listed: calculated as a molar percentage based on oxides, it contains 50% to 70% SiO2, 15% to 30% Li2O, 1% to 10% Al2O3, 0.5% to 5% P2O5, 0.5% to 8% ZrO2, 0.1% to 10% MgO, 0 to 5% Y2O3, 0 to 10% B2O3, 0 to 3% Na2O, 0 to 1% K2O and 0 to 2% SnO2.

[0198] The total amount of SiO2, Al2O3, P2O5 and B2O3 in the present amorphous glass is preferably 60% to 80%. In addition, the ratio of the total amount of Li2O, Na2O and K2O to the total amount of SiO2, Al2O3, P2O5 and B2O3 is preferably 0.20 to 0.60.

[0199] In order to prevent structural relaxation during chemical strengthening, the glass transition temperature Tg of the present amorphous glass is preferably 400°C or higher, more preferably 450°C or higher, and even more preferably 500°C or higher. Furthermore, the glass transition temperature Tg of the present amorphous glass is preferably 650°C or lower, more preferably 600°C or lower.

[0200] The difference (Tx-Tg) between the glass transition temperature (Tg) obtained by crushing the present amorphous glass and obtaining a DSC curve using a differential scanning calorimeter and the crystallization onset temperature (Tx) appearing in the lowest temperature region of the DSC curve is preferably 50°C or higher, more preferably 60°C or higher, further preferably 70°C or higher, and particularly preferably 80°C or higher. When (Tx-Tg) is large, the microcrystalline glass can be easily reheated for bending, etc.

[0201] The average thermal expansion coefficient of the amorphous glass at 50°C to 350°C is preferably 70×10 -7 / ℃ or more, more preferably 75×10 -7 / ℃ or above, most preferably 80×10 -7 / ℃ or above.

[0202] When the thermal expansion coefficient is too large, cracks may occur during the chemical strengthening process due to the thermal expansion difference. Therefore, it is preferably 120×10 -7 / ℃ or less, more preferably 110×10-7 / °C or less, more preferably 100×10 -7 / ℃ below.

[0203] Furthermore, when the thermal expansion coefficient is such, it is suitable as a support substrate for a semiconductor package having a high resin component.

[0204] <Method for producing chemically strengthened glass>

[0205] The chemically strengthened glass of the present invention is produced by chemically strengthening glass-ceramics. The glass-ceramics is produced by crystallizing the aforementioned amorphous glass by heating the amorphous glass.

[0206] (Manufacturing of amorphous glass)

[0207] Amorphous glass can be produced, for example, by the following method. The production method described below is an example of producing a plate-shaped chemically strengthened glass.

[0208] Glass raw materials are mixed to obtain a glass of preferred composition and then heated and melted in a glass melting furnace. The molten glass is then homogenized by bubbling, stirring, and the addition of clarifiers. The molten glass is then formed into a glass sheet of a specified thickness using known forming methods and slowly cooled. Alternatively, the molten glass can be formed into a sheet by forming the molten glass into a block, slowly cooling it, and then cutting it.

[0209] (Crystallization treatment)

[0210] The amorphous glass obtained through the above-described operation steps is subjected to a heat treatment (for example, preferably at 450° C. or higher and 800° C. or lower) to obtain crystallized glass.

[0211] The heat treatment may be performed in a two-step heating process, wherein the temperature is raised from room temperature to a first treatment temperature and held for a predetermined time, followed by holding for a predetermined time at a second treatment temperature higher than the first treatment temperature. Alternatively, the heat treatment may be performed in a one-step heating process, wherein the temperature is held at a specific treatment temperature and then cooled to room temperature.

[0212] When using a two-step heating process, the first treatment temperature is preferably within a temperature range that increases the crystal nucleation rate for the glass composition, and the second treatment temperature is preferably within a temperature range that increases the crystal growth rate for the glass composition. Furthermore, the first treatment temperature is preferably maintained for a long period of time to generate a sufficient number of crystal nuclei. By generating a large number of crystal nuclei, the size of each crystal is reduced, resulting in highly transparent glass-ceramics.

[0213] In the case of a two-step treatment, for example, a first treatment temperature of 450°C to 700°C is maintained for 1 to 6 hours, and then a second treatment temperature of 600°C to 800°C is maintained for 1 to 6 hours. In the case of a one-step treatment, for example, a temperature of 500°C to 800°C is maintained for 1 to 6 hours.

[0214] The molten glass can be homogenized and formed into a glass plate of a predetermined thickness, or the molten glass can be formed into a block and then continuously crystallized.

[0215] When heat treating a glass plate, examples of the support plate include silicon carbide plates, silicon nitride plates, SiN plates, alumina plates, mullite / cordierite plates, mullite plates, and glass-ceramics plates. Furthermore, to reduce temperature variations during heat treatment, a material with high thermal conductivity is preferred. The thermal conductivity of the support plate is preferably 2 W / (m·K) or higher, more preferably 20 W / (m·K) or higher, and even more preferably 40 W / (m·K) or higher.

[0216] To prevent adhesion between the glass and the support plate, a release agent can be used. Examples of release agents include alumina cloth and glass cloth. Other examples include powdered boron nitride, aluminum oxide, and minerals. Powdered release agents can be mixed with a solvent and applied by spraying, for example. When using a granular release agent, the average particle size is preferably 80 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less.

[0217] When heat treating the glass, the glass may be laminated to improve the efficiency of the operation. When laminating, a release agent is preferably used between the glass and the glass. In addition, a support plate may be placed between the glass and the glass.

[0218] The glass-ceramics obtained by the above-mentioned operation steps are ground and polished as needed to form a glass-ceramics plate. When the glass-ceramics plate is cut into a specified shape and size or is chamfered, it is preferred to cut or chamfer the plate before chemical strengthening because a compressive stress layer is also formed on the end face by the subsequent chemical strengthening treatment.

[0219] (Chemical strengthening treatment)

[0220] Chemical strengthening treatment is a treatment in which the glass is brought into contact with the metal salt by immersing the glass in a molten solution of a metal salt (e.g., potassium nitrate) containing metal ions with a large ionic radius (typically Na ions or K ions), thereby replacing the metal ions with a small ionic radius (typically Na ions or Li ions) in the glass with metal ions with a large ionic radius (typically, Na ions or K ions for Li ions, and K ions for Na ions).

[0221] To accelerate the chemical strengthening process, it is preferable to utilize "Li-Na exchange," which exchanges Li ions in the glass for Na ions. Furthermore, to generate high compressive stress through ion exchange, it is preferable to utilize "Na-K exchange," which exchanges Na ions in the glass for K ions.

[0222] Examples of molten salts used for chemical strengthening treatment include nitrates, sulfates, carbonates, and chlorides. Examples of nitrates include lithium nitrate, sodium nitrate, potassium nitrate, cesium nitrate, and silver nitrate. Examples of sulfates include lithium sulfate, sodium sulfate, potassium sulfate, cesium sulfate, and silver sulfate. Examples of carbonates include lithium carbonate, sodium carbonate, and potassium carbonate. Examples of chlorides include lithium chloride, sodium chloride, potassium chloride, cesium chloride, and silver chloride. These molten salts may be used alone or in combination.

[0223] Regarding the treatment conditions of the chemical strengthening treatment, the time and temperature can be selected in consideration of the glass composition, the type of molten salt, etc. For example, it can be mentioned that the present glass-ceramics is preferably subjected to a chemical strengthening treatment at a temperature of 450° C. or less for a period of preferably 1 hour or less. Specifically, for example, it can be mentioned that the glass-ceramics is preferably immersed in a molten salt containing 0.3% by mass of Li and 99.7% by mass of Na (for example, a mixed salt of lithium nitrate and sodium nitrate) at a temperature of 450° C. for preferably about 0.5 hours.

[0224] Chemical strengthening treatment can utilize a two-step ion exchange process, for example, as follows. First, the glass-ceramics is preferably immersed in a metal salt containing Na ions (e.g., sodium nitrate) at a temperature of about 350°C to about 500°C for about 0.1 to about 10 hours. This allows for ion exchange between the Li ions in the glass-ceramics and the Na ions in the metal salt, thereby forming a relatively deep compressive stress layer.

[0225] Next, the material is immersed in a metal salt containing K ions (e.g., potassium nitrate) at a temperature of approximately 350°C to 500°C for approximately 0.1 to 10 hours. This generates a high compressive stress within the compressive stress layer formed by the previous treatment, for example, within a depth of approximately 10 μm. This two-step treatment easily produces a stress distribution with high surface compressive stress values.

[0226] <Semiconductor support substrate>

[0227] The semiconductor support substrate of the present invention (hereinafter sometimes referred to as support glass) is described below. The semiconductor support substrate of the present invention comprises the amorphous glass or microcrystalline glass of the present invention. To increase strength, it preferably comprises the tempered glass of the present invention.

[0228] This amorphous glass, glass-ceramic, or tempered glass has a high coefficient of thermal expansion, making it suitable for use as a support substrate in fan-out packages. In fan-out packages, packages with various average coefficients of thermal expansion are formed depending on the ratio of the semiconductor chip to the resin component. However, in recent years, there has been a demand for improving the fluidity of the molding resin and reducing filling defects, resulting in the widespread use of packages with a high resin content and a high average coefficient of thermal expansion.

[0229] Figure 6 (A) and Figure 6 (B) is an example of a cross-sectional view of a support glass bonded to a semiconductor substrate. Figure 6 The supporting glass G1 shown in (A) is bonded to the conductive substrate 10 at a temperature of 200°C to 400°C via a peeling layer 20 (which may also function as a bonding layer), thereby obtaining Figure 6 (B) shows a laminated substrate 30. Semiconductor substrate 10 may be, for example, a full-size semiconductor wafer, a semiconductor chip, a substrate obtained by molding a semiconductor chip with resin, or a wafer with components formed thereon. The release layer 20 may be made of, for example, a resin that can withstand temperatures of 200°C to 400°C.

[0230] This support substrate is bonded to a semiconductor substrate for use. For example, it can be used as support glass for fan-out wafer-level packaging, support glass for image sensors such as MEMS, CMOS, and CIS, which utilize wafer-level packaging to effectively miniaturize components, support glass with through-holes (glass interposer; GIP), and support glass for semiconductor backside grinding. This support glass is particularly suitable as support glass for fan-out wafer-level and panel-level packaging.

[0231] Figure 7 This is an example of a cross-sectional view of a laminate substrate in which the present supporting glass is used as a supporting substrate for fan-out wafer-level packaging.

[0232] In fan-out chip-level packaging, for example, at a temperature of 200°C to 400°C, the support glass G2 and the semiconductor substrate 40 are stacked via a peeling layer 50 (which may also serve as a bonding layer) such as a resin. In addition, a stacked substrate 70 is obtained by embedding the semiconductor substrate 40 with a resin 60. Then, for example, ultraviolet rays are passed through the support glass G2 to irradiate the peeling layer 50 with a laser, thereby peeling the support glass G2 and the semiconductor substrate 40 embedded with the resin 60. The support glass G2 can be reused. The semiconductor substrate 40 embedded with the resin 60 is wired by copper wires, etc. In addition, wiring of copper wires, etc. may also be performed in advance on the peeling layer. It should be noted that a substrate obtained by embedding a semiconductor chip with a resin 60 may also be used as a semiconductor substrate.

[0233] Since the present supporting substrate has high light transmittance, visible light laser and ultraviolet laser having high energy can be effectively utilized as the laser used for the lift-off.

[0234] [Example]

[0235] Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited thereto.

[0236] [Experimental Example 1]

[0237] <Production and Evaluation of Amorphous Glass>

[0238] Glass raw materials were prepared to obtain the glass compositions shown in Tables 1 and 2 in terms of mol % based on oxides, and weighed to yield 800 g of glass. The mixed glass raw materials were then placed in a platinum crucible and placed in a 1600°C electric furnace for melting for approximately 5 hours, followed by degassing and homogenization.

[0239] The resulting molten glass was poured into a mold, held at the glass transition temperature for 1 hour, and then cooled to room temperature at a rate of 0.5°C / minute to obtain a glass block. A portion of the resulting block was used to evaluate the glass transition temperature, specific gravity, Young's modulus, fracture toughness, and thermal expansion coefficient of the amorphous glass. The results are shown in Tables 1 and 2.

[0240] Blank columns in the table indicate no evaluation. R2O in the table represents the total content of Li2O, Na2O, and K2O, and NWF represents the total content of SiO2, Al2O3, P2O5, and B2O3.

[0241] G3 to G8, G11, G13, and G14 are examples of the amorphous glass of the present invention, and G1, G2, G9, G10, G12, G15, and G16 are comparative examples.

[0242] (Specific gravity ρ)

[0243] The measurement was performed using the Archimedes method.

[0244] (Glass transition temperature Tg)

[0245] The glass was crushed using an agate mortar, and about 80 mg of the powder was placed in a platinum pool. The temperature was raised from room temperature to 1100°C at a heating rate of 10 / min. A differential scanning calorimeter (manufactured by Bruker; DSC3300SA) was used to measure the DSC curve and determine the glass transition temperature Tg.

[0246] Alternatively, a thermal expansion curve was obtained using a thermal dilatometer (manufactured by Bruker AXS; TD5000SA) in accordance with JIS R1618:2002 at a heating rate of 10°C / min. The glass transition temperature Tg [unit: °C] and the thermal expansion coefficient [unit: 1 / K] were determined from the obtained thermal expansion curve.

[0247] (Haze value)

[0248] The haze value [unit: %] under a halogen lamp C light source was measured using a haze meter (manufactured by Suga Test Instruments; HZ-V3).

[0249] (Young's modulus E)

[0250] The measurement was performed by an ultrasonic pulse method (JIS R1602).

[0251] (Fracture toughness value Kc)

[0252] The measurement was conducted by the IF method in accordance with JIS R1607:2015.

[0253]

[0254]

[0255] <Crystallization Treatment and Evaluation of Glass-Ceramics>

[0256] The resulting glass block was processed into a size of 50 mm × 50 mm × 1.5 mm and then heat treated under the conditions listed in Tables 3 and 4 to produce glass-ceramics. In the crystallization conditions column of the table, the upper row indicates the nucleation treatment conditions, and the lower row indicates the crystal growth treatment conditions. For example, if the upper row indicates 550°C for 2 hours and the lower row indicates 730°C for 2 hours, this means the conditions were maintained at 550°C for 2 hours and then at 730°C for 2 hours.

[0257] The effectiveness of release agents was confirmed during the crystallization process. When G13 glass was heat-treated on an alumina support plate without a release agent, the glass adhered to the plate. When boron nitride was used as a release agent, the glass and the support plate did not adhere, resulting in glass-ceramics. Using alumina cloth, alumina flakes, alumina particles, glass cloth, and talc as release agents, no adhesion occurred, and glass-ceramics were obtained.

[0258] Glass-ceramics were obtained by heat-treating G13 glass using an alumina sheet as a release agent and using a SiC plate, an alumina plate, a mullite-cordierite plate, and a mullite plate as support plates.

[0259] Examples 4, 5, 7, 9, 12 to 14 are embodiments, and Examples 1 to 3, 6, 8, 10, and 11 are comparative examples.

[0260] The obtained glass-ceramics were processed and mirror-polished to obtain glass-ceramics plates with a thickness t of 0.7 mm. In addition, rod-shaped samples were prepared for measuring the thermal expansion coefficient. A portion of the remaining glass-ceramics was crushed and used for analysis of precipitated crystals. The evaluation results of the glass-ceramics are shown in Tables 3 and 4. Blank columns indicate no evaluation.

[0261] (X-ray diffraction: precipitated crystals)

[0262] Powder X-ray diffraction was measured under the following conditions to identify the precipitated crystals.

[0263] Measuring device: Smart Lab, manufactured by Rigaku Corporation, Japan

[0264] X-rays used: CuKα rays

[0265] Measuring range: 2θ = 10° to 80°

[0266] Speed: 1° / min

[0267] Step distance: 0.01°

[0268] The main crystals detected are shown in the crystal column of Tables 3 and 4. Since it is difficult to distinguish between Li3PO4 and Li4SiO4 by powder X-ray diffraction, both are recorded. Figure 1 2 shows the results of measuring the glass-ceramics of Example 4 by X-ray diffraction.

[0269] (Haze value)

[0270] The haze value [unit: %] under a halogen lamp C light source was measured using a haze meter (manufactured by Suga Test Instruments; HZ-V3).

[0271] (CIL)

[0272] Prepare a plate of glass with a thickness of 0.7 mm and mirror-polished on both sides. Use a Vickers hardness tester to press the Vickers indenter (the angle of the front end is 136°) for 15 seconds, then remove the Vickers indenter and observe the vicinity of the indentation after 15 seconds. During the observation, it was studied how many cracks were generated from the corners of the indentation. The indentation load of the Vickers indenter of 10gf, 25gf, 50gf, 100gf, 200gf, 300gf, and 500gf was measured on 10 pieces of glass respectively. The average value of the number of cracks generated was calculated according to each load. The relationship between the load and the number of cracks was regressed using the S-type function. According to the regression calculation results, the load with 2 cracks was used as the above-mentioned indentation load value (gf). It should be noted that the atmospheric conditions for the measurement were an air temperature of 25°C and a dew point of -40°C.

[0273] (ST Limit)

[0274] As the test glass plates, a plurality of test glass plates having different ST values ​​were prepared by subjecting a 15 mm square, 0.7 mm thick glass plate having a mirror-finished surface to chemical strengthening treatment under various conditions.

[0275] Using a Vickers testing machine, a diamond indenter with a 90° tip angle is driven into the center of a test glass plate, causing it to fracture. The number of fragments produced is counted as the number of broken pieces. The test is started with a diamond indenter load of 1 kgf. If the glass plate does not crack, the load is increased by 1 kgf at a time. This test is repeated until the glass plate breaks. The number of broken pieces at the initial break is counted.

[0276] The number of broken pieces was plotted against the ST value of the test glass plate, and the ST value when the number of broken pieces reached 10 was read as the ST limit.

[0277]

[0278] Table 4

[0279]

[0280] The heat treatment conditions for G5 in Examples 5 and 6, as shown in Tables 3 and 4, differ, while the heat treatment conditions for G6 in Examples 7 and 8 differ. Comparisons of Examples 5 and 6, and 7 and 8, show that even with identical compositions, the glass-ceramics of the present invention exhibit varying haze levels due to changes in the heat treatment temperature. The glass-ceramics of the present invention exhibit excellent transparency, exhibiting reduced haze levels due to the precipitation of Li₃PO₄ or Li₄SiO₄.

[0281] Chemical Strengthening Treatment and Evaluation of Strengthened Glass

[0282] The glass-ceramics of Examples 4 and 14 were chemically strengthened by the following method, and designated as Examples 15 and 16, respectively. Examples 15 and 16 are examples. A molten salt containing 0.3% by mass of lithium nitrate and 99.7% by mass of sodium nitrate was used as a strengthening salt, and an ion exchange treatment was performed by maintaining the mixture at 450°C for 30 minutes, thereby obtaining a chemically strengthened glass. The stress distribution of the obtained chemically strengthened glass was measured using a scattered light photoelastic stress meter SLP-2000 manufactured by Orihara Manufacturing Co., Ltd. The results are shown in Table 5. In Table 5, the glass-ceramics of glass G4 is indicated as GC4, and the glass-ceramics of glass G14 is indicated as GC14. In addition, in Figure 2 9 shows the stress distribution of chemically strengthened glass S1 obtained by chemically strengthening the glass-ceramics of Example 4.

[0283] Table 5

[0284]

[0285] As shown in Table 5, the chemically strengthened glass of the present invention is excellent in transparency and strength.

[0286] [Experimental Example 2]

[0287] <Production and Evaluation of Amorphous Glass>

[0288] Amorphous glass having the glass composition shown in Table 6 in terms of mol% based on oxides was prepared in the same manner as in Experimental Example 1, and its properties were evaluated. The fracture toughness value K1c was evaluated by the following method. The results are shown in Table 6.

[0289] (Fracture toughness value K1c)

[0290] The fracture toughness value K1c (unit: MPa·m) was measured by DCDC method. 1 / 2 ). With reference to the method described in MYHe, MRTurner and AGEvans, Acta Metall. Mater. 43 (1995) 3453., the DCDC method was used. Figure 4 The sample of the shape shown and SHIMADZU Autograph AGS-X5KN were measured as follows Figure 5 The stress expansion coefficient K1 (unit: MPa·m 1 / 2 ) and the crack growth rate v (unit: m / s) are plotted in the K1-v curve. The data of Region III obtained are regressed and extrapolated using a first-order equation, and the stress expansion coefficient K1 at 0.1 m / s is taken as the fracture toughness value K1c.

[0291]

[0292] <Crystallization Treatment and Evaluation of Glass-Ceramics>

[0293] Glass-ceramics were obtained and their properties were evaluated in the same manner as in Experimental Example 1. However, X-ray diffraction was evaluated under the following conditions.

[0294] (X-ray diffraction: precipitated crystals)

[0295] Powder X-ray diffraction was measured under the following conditions to identify the precipitated crystals.

[0296] Measuring device: Smart Lab, manufactured by Rigaku Corporation, Japan

[0297] X-rays used: CuKα rays

[0298] Measuring range: 2θ = 10° to 80°

[0299] Speed: 10° / min

[0300] Step distance: 0.02°

[0301] The results are shown in Table 7. In Table 7, Examples 18 to 27 are Examples, and Example 17 is a Comparative Example.

[0302]

[0303] As shown in Table 7, the glass of the present invention has a small haze value and excellent transparency.

[0304] The chemical resistance of Example 2 in Table 3 and Example 21 in Table 7 was evaluated. The samples were immersed in pH 1 HCl at room temperature for 1 minute, followed by immersion in pH 12.5 NaOH at 65°C for 6 minutes. The haze and transmittance were then measured. The haze of Example 2 increased to 0.73%, while the transmittance at 550 nm decreased by 4.8%. On the other hand, the haze of Example 21 remained almost unchanged at 0.03%, while the transmittance at 550 nm decreased by only 0.7%. This indicates that Example 21, which precipitated Li₃PO₄ crystals, exhibited superior chemical resistance compared to Example 2, which precipitated Li₂SiO₃ crystals.

[0305] [Experimental Example 3]

[0306] <Production and Evaluation of Amorphous Glass>

[0307] Amorphous glass having the glass composition shown in Table 8 (in mol % based on oxides) was produced in the same manner as in Example 1, and its properties were evaluated. However, SO₃, Cl, and SnO₂ added as clarifiers were expressed in mass %. The results are shown in Table 8.

[0308] Table 8

[0309] mol% G29 G30 G31 G32 G33 G34 <![CDATA[SiO2]]> 61 61 61 61 61 61 <![CDATA[Al2O3]]> 5 5 5 5 5 5 <![CDATA[Li2O]]> 21 21 21 21 21 21 <![CDATA[Na2O]]> 2 2 2 2 2 2 <![CDATA[K2O]]> 0 0 0 0 0 0 CaO 0 0 0 0 0 0 <![CDATA[P2O5]]> 2 2 2 2 2 2 <![CDATA[B2O3]]> 0 0 0 0 0 0 MgO 5 5 5 5 5 5 <![CDATA[ZrO2]]> 3 3 3 3 3 3 <![CDATA[Y2O3]]> 1 1 1 1 1 1 <![CDATA[SO3 (% by weight)]]> 0.3 0.3 0 0 0 0 Cl (wt%) 0 0 1 1 0.5 1 <![CDATA[SnO2 (wt%)]]> 0.05 0.1 0.05 0.1 0 0 <![CDATA[ρ(g / cm 3 )]]> 2.56 2.56 2.56 2.56 2.56 2.56 Tg(℃) 513 Haze (%) 0.02 0.02 0.02 0.02 0.02 0.02 E(GPa) 90 90 90 90 90 90 <![CDATA[Kc(MPa·m 1 / 2 )]]> 0.95 0.95 0.95 0.95 0.95 0.95 <![CDATA[K1c(MPa·m 1 / 2 )]]> 0.85 0.85 0.85 0.85 0.85 0.85

[0310] <Crystallization Treatment and Evaluation of Glass-Ceramics>

[0311] Glass-ceramics were obtained in the same manner as in Example 1, and their properties were evaluated. The results are shown in Table 9. In Table 9, Examples 28 to 33 are all Examples.

[0312] Table 9

[0313]

[0314] As shown in Table 9, it can be seen that the optical and mechanical properties of the glass of the present invention are not affected even when the clarifiers SO 3 , Cl, and SnO 2 are added alone or in combination.

[0315] The polishing rates of amorphous glass and the glass of the present invention are shown in Table 10. Example 34 is a comparative example, and Examples 4 and 21 are examples.

[0316] Table 10

[0317]

[0318] As shown in Table 10, it can be seen that the glass of the present invention has a higher polishing rate after crystallization than ordinary amorphous glass and is excellent in processability.

[0319] Figure 3 The cross-sectional FE-SEM image of Example 21 is shown. Figure 3 In the figure, white arrows indicate examples of precipitated crystals. The size of the precipitated crystals measured under the following conditions was found to be 20 nm to 50 nm. Due to their small size, they are less susceptible to scattering and exhibit excellent optical properties.

[0320] Apparatus: Measurement was performed using JSM-7800F Prime manufactured by JEOL.

[0321] Measurement conditions:

[0322] Vacc: 5kV, Coating: W, UED image

[0323] In the Rydberg analysis, the precipitated crystals are Li 6.5 In the case of (Si,P)O8, the crystallinity is 18.2% and the crystal grain size is 15 nm.

[0324] Although the present invention is described in detail with reference to specific embodiments, various changes and corrections can be made without departing from the spirit and scope of the present invention, which will be apparent to those skilled in the art. It should be noted that this application is based on Japanese patent applications (Japanese patent application 2020-140347) filed on August 21, 2020 and Japanese patent applications (Japanese patent application 2021-090475) filed on May 28, 2021, and the full text of these applications is incorporated herein by reference. In addition, all references cited herein are incorporated herein in their entirety.

Claims

1. A glass substrate, wherein: The glass substrate contains, in terms of mol% based on oxides: 54% to 64% SiO2, 3% to 8% Al2O3, 0.5% to 4.2% P2O5, 4% to 7% MgO, 10% to 26% Li2O, 1% to 2.5% Na2O, 1% to 3.5% ZrO2, 0% to 4% Y2O3, The total amount of SiO2, Al2O3, P2O5 and B2O3 in the glass substrate is 60% to 80% in terms of mole % of oxide basis. The ratio of the total amount of Li2O, Na2O and K2O in the glass substrate to the total amount of SiO2, Al2O3, P2O5 and B2O3 is 0.20 to 0.60, calculated as mol% on an oxide basis. The Young's modulus of the glass substrate is 90 GPa to 110 GPa, The average thermal expansion coefficient of the glass substrate at 50°C to 350°C is 80×10 -7 / ℃~110×10 -7 / ℃.

2. The glass substrate according to claim 1, wherein (Al2O3 / Li2O) / NWF is 0.0032~0.0051, and NWF represents the total content of SiO2, Al2O3, P2O5 and B2O3.

3. A semiconductor support substrate, wherein: The semiconductor support substrate includes the glass substrate according to claim 1 .

4. A laminate substrate suitable for fan-out wafer-level packaging, wherein: The glass substrate according to claim 1 is laminated with a semiconductor substrate via a peeling layer, wherein the semiconductor substrate is a substrate obtained by molding a semiconductor chip with a resin.

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