Glass substrate

Abstract

Provided is a glass substrate that suppresses cracks during laser processing. Marks (100) are provided on the surface of the glass substrate (10), and a parameter (y) defined by formula (1) is less than 1.4.

Description

Technical Field

[0001] The invention relates to a glass substrate. Background Art

[0002] In the manufacturing process of semiconductor devices, glass substrates are sometimes used as components for supporting semiconductor devices. For example, as shown in Patent Documents 1 and 2, a mark is sometimes formed on the surface of such a glass substrate by irradiating the surface with a laser. Glass is increasingly used as a substrate for semiconductor devices and a cover glass for image sensors. For glass used in semiconductor processes, a mark for identification is generally required on the surface of the glass.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2018 / 150759

[0006] Patent Document 2: Japanese Patent Application Publication No. 2019-131462 Summary of the invention

[0007] However, since the glass substrate is sometimes highly brittle, cracks may be generated due to stress concentration, residual stress, and microcracks around the marks formed on the surface. Therefore, it is necessary to suppress cracks in the glass substrate.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a glass substrate capable of suppressing cracking.

[0009] In order to solve the above problems and achieve the purpose, the glass substrate of the present disclosure is a glass substrate having a mark provided on the surface thereof, wherein the parameter y defined by the following formula (1) is less than 1.4.

[0010] y=0.021·C-0.0034·Tg-0.012·ρ+0.020·E-2.814·λ-0.433·Ra+4.372···(1)

[0011] Here, C is the average thermal expansion coefficient of the glass substrate at 50°C to 200°C (ppm / °C), Tg is the glass transition temperature of the glass substrate (°C), and ρ is the density of the glass substrate (g / cm 3 ), E is the Young's modulus of the above-mentioned glass substrate (GPa), λ is the thermal conductivity of the above-mentioned glass substrate (W / m·℃), and Ra is the arithmetic mean roughness (nm) of the above-mentioned surface of the above-mentioned glass substrate as specified in JISB 0601:2001.

[0012] According to the present invention, cracks starting from the glass mark and the periphery of the mark can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the glass substrate of this embodiment.

[0014] Figure 2 is a schematic diagram of an example of labeling.

[0015] Figure 3 This is a schematic enlarged view of a portion of a glass substrate where dots are formed.

[0016] Figure 4 yes Figure 3 A-A cross-section diagram. DETAILED DESCRIPTION

[0017] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. It should be noted that the present invention is not limited to the embodiments, and when there are multiple embodiments, the embodiments are also combined to form a solution. In addition, the numerical values ​​include the range of rounding.

[0018] (Glass Substrate)

[0019] Figure 1 : is a schematic diagram of the glass substrate of the present embodiment. The glass substrate 10 of the present embodiment is used as a glass substrate for manufacturing semiconductor packages, and can be said to be a glass substrate for supporting semiconductor devices. More specifically, the glass substrate 10 is a supporting glass substrate for manufacturing using the fan-out wafer level package (FOWLP) technology. For example, when the glass substrate 10 is rectangular, it is a supporting glass substrate for manufacturing the fan-out panel level package (FOPLP). However, the use of the glass substrate 10 is not limited to the support of semiconductor devices, the manufacture of FOWLP and FOPLP, and is arbitrary, and can be a glass substrate for supporting any component. In addition, it can also be glass or crystallized glass processed into any product such as cover glass for image sensors, substrates for semiconductor devices, etc.

[0020] like Figure 1As shown, the glass substrate 10 is a plate-shaped component having a main surface, i.e., a surface 10A (a surface) and a main surface, i.e., a surface 10B (another surface), on the side opposite to the surface 10A. The glass substrate 10 is a circular plate shape that is circular when viewed from a top view, i.e., from a direction orthogonal to the surface 10A. In other words, the glass substrate 10 is in the shape of a wafer. In addition, the glass substrate 10 can be a shape in which a notch N is formed on the outer peripheral surface and a part of the circular outer periphery is cut off. However, the shape of the glass substrate 10 is not limited to a circular plate shape, and can be any shape, for example, a polygonal plate such as a rectangular plate. In addition, the notch N is not necessarily constituted, and the notch N may not be formed in the glass substrate 10. For example, in the case where the glass substrate 10 is a circular plate as described later, it is preferred to form the notch N. Below, the direction orthogonal to the surface 10A is recorded as the Z direction. The Z direction can also be said to be the thickness direction of the glass substrate 10.

[0021] (Diameter of glass substrate)

[0022] The diameter D0 of the glass substrate 10 is preferably 150 mm to 1000 mm, preferably 150 mm to 700 mm, more preferably 150 mm to 600 mm, and more preferably 150 mm to 450 mm. When the diameter D0 is in this range, components such as semiconductor devices can be properly supported. It should be noted that the diameter D0 refers to the diameter when the glass substrate 10 is circular, and can refer to the maximum value of the distance between any two points on the outer periphery of the glass substrate 10 when the glass substrate 10 is not circular.

[0023] When the glass substrate 10 is a disk, the diameter D0 is preferably 450 mm or less, more preferably 300 mm or less. When the glass substrate 10 is a rectangular plate, the diameter D0 (i.e., the maximum value of the distance between any two points on the outer circumference) is preferably 300 mm to 1000 mm.

[0024] (Thickness of glass substrate)

[0025] The thickness of the glass substrate 10, i.e., the length in the Z direction between the surface 10A and the surface 10B, is preferably 2 mm or less, more preferably 0.3 mm to 2.0 mm, further preferably 0.5 mm to 2.0 mm, further preferably 0.5 mm to 1.8 mm, further preferably 0.6 mm to 1.5 mm. When the thickness of the glass substrate 10 is 2 mm or less, the difficulty of operation due to the increase in weight can be suppressed. In addition, when the thickness is greater than 0.3 mm, the rigidity when used as a supporting member is increased, and the warping of glass and semiconductor devices can be suppressed.

[0026] In addition, when the glass substrate 10 is in a circular plate shape, the thickness is preferably 0.3 mm to 2.0 mm, and when the glass substrate 10 is in a rectangular plate shape, the thickness is preferably 0.5 mm to 2.0 mm.

[0027] The deviation of the thickness of the glass substrate 10 is preferably less than 10 μm, more preferably less than 5 μm, further preferably less than 3 μm, and further preferably less than 1 μm. By making the thickness deviation within this range, the thickness of the glass substrate 10 is close to uniform, semiconductor devices can be appropriately manufactured, and stable processing can be performed in the formation of marks. It should be noted that the thickness deviation refers to the difference between the maximum and minimum values ​​of the thickness at each position (each coordinate) on the plane along the surface of the glass substrate 10. For example, the thickness of each position (coordinate) on the plane along the surface of the glass substrate 10 can be calculated at the position, and the difference between the maximum and minimum values ​​of the thickness at each position is taken as the thickness deviation.

[0028] In addition, the LTV (Local Thickness Variation) of the glass substrate 10 of 50 mm×50 mm is preferably 1 μm or less, and more preferably 0.5 μm or less. The LTV of 50 mm×50 mm refers to the difference between the maximum value and the minimum value of the thickness in a unit area of ​​50 mm×50 mm at any position of the glass substrate 10. In other words, the thickness variation refers to the difference between the maximum value and the minimum value of the thickness of the entire region of the glass substrate 10, while LTV refers to the difference between the maximum value and the minimum value of the thickness of a unit area of ​​the glass substrate 10.

[0029] (mark)

[0030] The surface 10A of the glass substrate 10 is formed with a mark 100. The mark 100 may be, for example, an identifier consisting of at least one of a number, a character, a two-dimensional code, and a graphic. The number, the character, the two-dimensional code, and the graphic may be one or more. The mark 100 as an identifier may be said to be a mark for identifying the glass substrate 10. The mark 100 as an identifier may be used, for example, for identification and management of the glass substrate 10.

[0031] The mark 100 is not limited to being an identifier for identifying the glass substrate 10, and may be, for example, an alignment mark. The alignment mark is, for example, a mark for positioning the glass substrate 10, and may be used for aligning the position and direction of the glass substrate 10 during processing such as handling, cutting, chamfering, and bonding. In addition, the alignment mark may be a mark for determining the direction of the glass. That is, when stacking devices on the glass substrate, the alignment mark may be formed on the opposite side of the surface on which the devices are stacked to match the variation in warpage during the manufacture of the devices.

[0032] It should be noted that, hereinafter, one number, character, or graphic constituting the mark 100 is referred to as a mark element 102. That is, the mark 100 is constituted by a plurality of mark elements 102. However, the mark 100 may be constituted by one mark element 102.

[0033] Figure 2 is a schematic diagram of an example of labeling. Figure 2 In the example, the mark 100 is represented as an identifier composed of 12 marking elements 102 arranged in a straight line. However, the mark 100 is not limited to this method. For example, the mark 100 may be composed of the marking elements 102 arranged in a non-linear shape. In addition, the mark 100 may also be composed of the marking elements 102 arranged in more than two rows in a straight line or a non-linear shape.

[0034] The overall size of the marker 100 is not particularly limited, and can be, for example, Figure 2 In the case of the linear arrangement of the marking elements 102 shown, the interval L1 of the characters is in the range of 1.420±0.025 mm, and the longitudinal length L2 can be 1.624±0.025 mm. It should be noted that when the mark 100 is composed of a non-linear arrangement of the marking elements 102, the interval L1 of the characters and the longitudinal length L2 of the mark 100 are respectively defined as the length of the first side and the length of the second side of the smallest rectangle when the smallest rectangle containing the mark 100 is assumed. It should be noted that the interval L1 of the characters refers to the distance between the center of the marking element 102 and the center of the marking element 102 adjacent to the marking element 102 in the horizontal direction, and the longitudinal length L2 refers to the longitudinal distance between the center of the point 104 closest to one side of the marking element 102 in the longitudinal direction and the center of the point 104 closest to the other side in the longitudinal direction.

[0035] The marking element 102 (marker 100) is composed of a plurality of dots 104. In other words, a marking element 102 and a mark 100 are formed by a plurality of dots 104. It should be noted that in the present embodiment, the dots 104 are formed separately without overlapping each other. The spacing P between adjacent dots 104 is specified by SEMI AUX015-1106 SEMIOCR CHARACTER OUTLINES and SEMI-T7-0303, and is specified by the type of font or two-dimensional code. It should be noted that the spacing P refers to the distance between the center of a dot 104 and the center of a dot 104 adjacent to the dot 104 in the direction along the surface 10A.

[0036] The dots 104 are formed by laser processing, mechanical processing such as sandblasting, chemical etching, printing, etc. In particular, when formed by laser processing, the marking element 102 can be composed of a plurality of laser irradiation marks. The size of the laser irradiation marks and the spacing of the irradiation marks are determined by the configuration of the optical system of the laser processing machine.

[0037] (point)

[0038] Figure 3 This is a schematic enlarged view of a portion of a glass substrate where dots are formed. Figure 4 yes Figure 3 A-A cross-section diagram. Figure 4 It can be said that it is a cross-sectional view of the glass substrate 10 when the plane PL passing through the center of the point 104 and along the Z direction is taken as a cross section. The point 104 refers to a depression formed on the surface 10A of the glass substrate 10. However, the shape of the point may not necessarily be a depression shape, that is, a concave shape. For example, when it is formed by printing, it is a convex shape. When the point is formed by sandblasting, the surface roughness of the part becomes larger and the visibility as a mark is improved. In the present embodiment, the point 104 is formed by irradiating the surface 10A with a laser. That is, the point 104 of the present embodiment can be said to be a laser irradiation mark (laser irradiation mark). One point 104 can be formed by multiple laser irradiation marks or by one laser irradiation mark. The laser can irradiate the same position multiple times to make the depth of the processed point easy to read, or it can irradiate while offsetting at a certain pitch to form a point. One laser irradiation mark refers to an irradiation mark formed by a laser triggered once. That is, the point 104 can be formed by a laser irradiated in one cycle from laser output to stop, or it can be formed by multiple laser irradiation marks. That is, the spot 104 can be formed by intermittently irradiating the laser light in a plurality of cycles.

[0039] (Shape of the point)

[0040] Hereinafter, an example of the shape of the dot 104 will be described, but the shape of the dot 104 is not limited to the following description, and may be any shape.

[0041] like Figure 3 As shown, point 104 is in the shape of a double circle when viewed from the Z direction. Figure 3 In the figure, for the sake of convenience, the concave area in the point 104 is marked with oblique lines. However, the shape of the point 104 when viewed from the Z direction is not limited to a double circle. For example, the point 104 may be a circle when viewed from the Z direction. In addition, a plurality of laser irradiation marks may be combined to form an incomplete circle such as a ring, a rectangle, or a letter "C", or a spiral shape.

[0042] like Figure 4As shown in FIG. 1 , the point 104 includes a first depression 104a which is a portion depressed from the surface 10A of the glass substrate 10, and a second depression 104b which is a portion depressed from the surface 10A of the glass substrate 10 radially outwardly relative to the first depression 104a. The first depression 104a and the second depression 104b are annular when viewed from the Z direction. In other words, the first depression 104a and the second depression 104b have a region which is more protruding than the first depression 104a and the second depression 104b on the radial inner side of the first depression 104a and the second depression 104b. The first depression 104a and the second depression 104b have a bottom surface 104A and a side surface 104B. The bottom surface 104A refers to the bottom portion of the first depression 104a and the second depression 104b, and the side surface 104B refers to the side surface portion connecting the bottom surface 104A of the first depression 104a and the second depression 104b to the surface 10A of the glass substrate 10. The side surface 104B includes a side surface portion 104B1, a connection portion 104B2, and a connection portion 104B3. The side surface portion 104B1 is a portion forming the side surface of the first recess 104a and the second recess 104b. The connection portion 104B2 is a portion formed at the end portion of the side surface portion 104B1 on the side opposite to the Z direction, and is in an R shape connecting the bottom surface 104A and the side surface portion 104B1. The connection portion 104B3 is a portion formed at the end portion of the side surface portion 104B1 on the Z direction side, and is in an R shape connecting the side surface portion 104B1 and the surface 10A of the glass substrate 10. However, the side surface 104B is not limited to the connection portions 104B2 and 104B3 which are in an R shape, and the connection portion between the bottom surface 104A and the side surface portion 104B1 and the connection portion between the side surface portion 104B1 and the surface 10A of the glass substrate 10 may be an edge shape (horn shape).

[0043] (Diameter of a point)

[0044] The diameter D of the dot 104 is preferably 50 μm to 200 μm, more preferably 80 μm to 150 μm, and further preferably 90 μm to 120 μm. When the diameter of the dot 104 is within this range, one dot 104 can be made larger, so that the mark 100 can be appropriately recognized. Figure 4 As shown in FIG. 1 , the diameter D of the point 104 may refer to the diameter of an imaginary circle formed by the intersection of the curved surface (corresponding to the side surface of the truncated cone) of the side surface portion 104B1 of the second recess 104b along the radial outer side and the plane along the surface 10A. In addition, when the point 104 is not circular, the longest distance between two points on the outer periphery of the imaginary region formed by the intersection of the surface of the side surface portion 104B1 of the second recess 104b along the radial outer side and the plane along the surface 10A may be used as the diameter D.

[0045] (Depth of point)

[0046] The depth H of the point 104 is preferably 0.5 μm to 7.0 μm, more preferably 0.5 μm to 5.0 μm, and further preferably 0.5 μm to 3.0 μm. When the depth H is within this range, cracks in the glass substrate 10 starting from the point 104 can be suppressed, and ease of reading can be ensured. It should be noted that the depth H refers to the distance between the surface 10A and the bottom surface 104A in the Z direction.

[0047] The depth H of the point 104 is measured by the following method. For the marked point, the cross-sectional shape of any point is measured using a laser microscope. Then, the lowest point of the cross section is set as S, and the difference in the Z direction between the main surface of the glass, that is, the surface 10A, and the lowest point S is set as the depth H. However, in the case where the periphery of the point has a concave shape as shown in FIG. 5, the depression of the periphery of the point may not be counted as the lowest point. The depth H can be measured using OLS4000 manufactured by OLYMPUS.

[0048] Furthermore, when the variation in the depth of the bottom surface portion excluding the depression generated on the radially inner side of the bottom surface is denoted as ΔH, ΔH is preferably 50% or less of the depth H, and more preferably 25% or less.

[0049] (parameter y)

[0050] The parameter y of the glass substrate 10 defined by the following formula (1) is less than 1.4, more preferably less than 0.8, and further preferably less than 0.5. When the parameter y is within this range, the formation of a crack starting from the mark 100 (point 104) is suppressed, and cracks in the glass substrate 10 starting from the crack can be suppressed.

[0051] y=0.021·C-0.0034·Tg-0.012·ρ+0.020·E-2.814·λ-0.433·Ra+4.372···(1)

[0052] In formula (1), C is the average thermal expansion coefficient of the glass substrate 10 at 50°C to 200°C (ppm / °C), Tg is the glass transition temperature of the glass substrate 10 (°C), and ρ is the density of the glass substrate 10 (g / cm 3 ), E is the Young's modulus of the glass substrate 10 (GPa), λ is the thermal conductivity of the glass substrate 10 (W / m·°C), and Ra is the arithmetic mean roughness (nm) of the surface 10A of the glass substrate as specified in JIS B 0601:2001.

[0053] (Average thermal expansion coefficient C)

[0054] The average thermal expansion coefficient C of the glass substrate 10 at 50° C. to 200° C. is preferably 3 ppm / ° C. or more and less than 12.1 ppm / ° C., more preferably 3.0 ppm / ° C. or more and less than 8.7 ppm / ° C., and further preferably 3.0 ppm / ° C. or more and less than 5.8 ppm / ° C. When the average thermal expansion coefficient C is within this range, the generation of cracks due to local expansion of the glass substrate 10 caused by heat absorption during processing of the point 104 can be suppressed.

[0055] The average thermal expansion coefficient C can be measured according to the method specified in JIS R3102 (1995). Specifically, the sample is measured in the range of 30°C to 300°C using DIL 402 manufactured by NETZSCH as a differential thermal dilatometer, and the average thermal expansion coefficient in the range of 50°C to 200°C is taken as the average thermal expansion coefficient C. It should be noted that the numerical range represented by "to" refers to a numerical range including the numerical values ​​before and after to as the lower limit and the upper limit, and the following use of "to" also means the same meaning.

[0056] (Average thermal expansion coefficient C cal )

[0057] The average thermal expansion coefficient C described above is a measured value of the average thermal expansion coefficient of the glass substrate 10. On the other hand, the calculated value of the average thermal expansion coefficient calculated from the composition of the glass substrate 10 is referred to as the average thermal expansion coefficient C. cal When the average thermal expansion coefficient C cal It is preferably 3.0 ppm / °C or more and less than 12.2 ppm / °C, more preferably 3.0 ppm / °C or more and less than 8.7 ppm / °C, and still more preferably 3.0 ppm / °C or more and less than 5.8 ppm / °C. cal When the thickness is within this range, the occurrence of cracks due to local expansion of the glass substrate 10 caused by heat absorption during processing of the dots 104 can be suppressed.

[0058] Average thermal expansion coefficient C cal Hereinafter, the content of the oxide XOn of the element X contained in the glass substrate 10 expressed as mol% based on the oxide is represented as [XOn]. In this case, the average thermal expansion coefficient C cal is a value calculated by the following formula (2).

[0059] C cal=-0.303·[SiO2]-0.338·[Al2O3]-0.303·[B2O3]-0.208·[P2O5]-0.198·[MgO]-0.2 25·[CaO]-0.133·[SrO]-0.104·[BaO]+0.071·[Na2O]+0.077·[K2O]+32.548···(2)

[0060] It should be noted that the glass substrate 10 is not limited to contain all the oxides listed in formula (2). In this case, the value on the right side of formula (2) for the oxides listed in formula (2) but not contained in the glass substrate 10 is recorded as zero. That is, for example, when the glass substrate 10 does not contain SrO, [SrO] in formula (2) is recorded as zero and the average thermal expansion coefficient C is calculated. cal The same is true for the following formula.

[0061] (Glass transition temperature Tg)

[0062] The glass transition temperature Tg of the glass substrate 10 is preferably 500° C. to 800° C., more preferably greater than 560° C. and less than 800° C., and further preferably greater than 714° C. and less than 750° C. When the average thermal expansion coefficient C is within this range, a structure that is stable against impact during processing of the point 104 is obtained, and the generation of cracks can be suppressed.

[0063] The glass transition temperature Tg can be measured according to the method specified in JIS R3103-3 (2001).

[0064] (Glass transition temperature Tg cal )

[0065] The glass transition temperature Tg described above is a measured value of the glass transition temperature of the glass substrate 10. On the other hand, if the calculated value of the glass transition temperature calculated from the composition of the glass substrate 10 is taken as the glass transition temperature Tg cal , then the glass transition temperature Tg cal It is preferably 500°C to 800°C, more preferably higher than 561°C and 800°C, and even more preferably higher than 712°C and lower than 741°C. cal By being within this range, the structure becomes stable against the impact during machining of the point 104, and the generation of cracks can be suppressed.

[0066] Glass transition temperature Tg cal It is calculated by the following formula (3).

[0067] Tg cal=-38.218·[SiO2]-24.844·[Al2O3]-49.133·[B2O3]-40.1·[MgO]-40.809·[CaO] -37.105·[SrO]-39.031·[BaO]-46.125·[Na2O]-52.247·[K2O]+4489.419···(3)

[0068] (density ρ)

[0069] The density ρ of the glass substrate 10 is preferably 2.4 g / cm 3 ~3.5g / cm 3 , more preferably 2.4 g / cm 3 Above and less than 3.5g / cm 3 , more preferably 2.4 g / cm 3 Above and less than 2.8g / cm 3 When the density ρ is within this range, it is not necessary to apply excessive energy to the glass substrate 10 at the processing point 104 , and the generation of cracks can be suppressed.

[0070] The density ρ can be measured by the Archimedean method.

[0071] (density ρ cal )

[0072] The density ρ described above is a measured value of the density of the glass substrate 10. On the other hand, if the calculated value of the density calculated from the composition of the glass substrate 10 is taken as the density ρ cal , then the density ρ cal Preferably 2.4 g / cm 3 ~3.5g / cm 3 , more preferably 2.4 g / cm 3 Above and less than 3.5g / cm 3 , more preferably 2.4 g / cm 3 Above and less than 2.8g / cm 3 Through the density ρ cal By setting the value within this range, it is not necessary to increase the energy applied to the glass substrate 10 at the processing point 104 excessively, and the generation of cracks can be suppressed.

[0073] Density ρ cal It is calculated by the following formula (4).

[0074] ρ cal=-0.007·[SiO2]-0.01·[Al2O3]-0.006·[B2O3]+0.006·[MgO]+0.008·[Ca O]+0.021·[SrO]+0.038·[BaO]-0.003·[Na2O]+0.001·[K2O]+2.931···(4)

[0075] (Young's modulus E)

[0076] The Young's modulus E of the glass substrate 10 is preferably greater than 70 GPa, and more preferably greater than 78 GPa. When the Young's modulus E is within this range, the generation of cracks can be suppressed.

[0077] The Young's modulus E can be measured by an ultrasonic pulse method using 38DL PLUS manufactured by OLYMPUS.

[0078] (Young's modulus E cal )

[0079] The Young's modulus E described above is a measured value of the Young's modulus of the glass substrate 10. On the other hand, if the calculated value of the Young's modulus calculated from the composition of the glass substrate 10 is taken as the Young's modulus E cal , then Young's modulus E cal It is preferably greater than 70 GPa, and more preferably greater than 78 GPa. cal Within this range, the occurrence of cracks can be suppressed.

[0080] Young's modulus E cal It can be calculated according to the following formula (5).

[0081] E cal =1.635·[SiO2]+2.428·[Al2O3]+0.924·[B2O3]+2.227·[MgO]+2.311·[CaO ]+1.359·[SrO]+1.861·[BaO]+1.127·[Na2O]+1.646·[K2O]-94.916···(5)

[0082] (Thermal conductivity λ)

[0083] The thermal conductivity λ of the glass substrate 10 is preferably greater than 0.8 W / m·°C, preferably greater than 0.8 W / m·°C and less than 1.4 W / m·°C, more preferably greater than 0.9 W / m·°C and less than 1.1 W / m·°C, and more preferably greater than 1.0 W / m·°C and less than 1.1 W / m·°C. When the thermal conductivity λ is within this range, the heat generated during the processing of the point 104 is appropriately transferred to the surroundings, and the generation of cracks due to local heating can be suppressed.

[0084] The thermal conductivity λ can be measured by the method specified in JIS R3102 (1995). Specifically, the thermal conductivity λ can be measured using a differential thermal dilatometer at a temperature of 30°C to 300°C, and the average value of the thermal conductivity at a temperature of 50°C to 200°C is recorded as the thermal conductivity λ.

[0085] (Thermal conductivity λ cal )

[0086] The thermal conductivity λ described above is a measured value of the thermal conductivity of the glass substrate 10. On the other hand, if the calculated value of the thermal conductivity calculated from the composition of the glass substrate 10 is taken as the thermal conductivity λ, cal , then the thermal conductivity λ cal It is preferably greater than 0.8 W / m·℃, preferably greater than 0.8 W / m·℃ and less than 1.4 W / m·℃, more preferably greater than 0.8 W / m·℃ and less than 1.1 W / m·℃, and further preferably greater than 0.8 W / m·℃ and less than 1.0 W / m·℃. cal When the temperature is within this range, the heat generated during processing of the point 104 is appropriately transferred to the surroundings, and the occurrence of cracks due to local heating can be suppressed.

[0087] Thermal conductivity λ cal It can be calculated according to the following formula (6).

[0088] λ cal =-0.026·[SiO2]-0.03·[Al2O3]-0.032·[B2O3]-0.016·[MgO]-0.008·[Ca O]+0.011·[SrO]-0.057·[BaO]-0.022·[Na2O]-0.044·[K2O]+3.502···(6)

[0089] (Arithmetic mean roughness Ra)

[0090] The arithmetic mean roughness Ra of the surface 10A of the glass substrate 10 described above may refer to the arithmetic mean roughness Ra at any position of the surface 10A. For example, the arithmetic mean roughness Ra of the surface 10A of the glass substrate 10 may be the arithmetic mean roughness Ra of the area (peripheral area) surrounding the mark 100 (point 104) in the area where the point 104 is not formed (in this example, the area where the first recess 104a and the second recess 104b are not formed). The area (peripheral area) surrounding the mark 100 (point 104) may be an area (peripheral area) within 5 mm from the point 104 in the area where the point 104 is not formed on the surface 10A. The arithmetic mean roughness Ra of the peripheral area is preferably 0.3 nm or more and less than 1.7 nm, more preferably greater than 0.5 nm and less than 1.7 nm, further preferably greater than 0.6 nm and less than 1.7 nm, and further preferably greater than 0.6 nm and less than 0.9 nm. The arithmetic mean roughness Ra of the periphery of the point 104 in the surface 10A is within this range, so that the energy during the processing of the point 104 is appropriately absorbed by the surface 10A, and the generation of cracks can be suppressed. It should be noted that the arithmetic mean roughness Ra is measured according to the provisions of JIS B0601:2001. The arithmetic mean roughness Ra can be measured by using OLYMPUS OLS4000 with the magnification of the objective lens set to 50 times.

[0091] The arithmetic mean roughness Ra of the surface 10A described above may be the arithmetic mean roughness Ra of the region where the dots 104 are formed (in this example, the region where the first recesses 104 a and the second recesses 104 b are formed).

[0092] The arithmetic mean roughness Ra of the area on the surface 10A of the glass substrate 10 that is further outward (radially further outward than the peripheral area) than the peripheral area of ​​the point 104 may be greater than or less than the above-mentioned preferred range of the arithmetic mean roughness Ra of the peripheral area. For example, in order to be used for high-precision devices, the arithmetic mean roughness Ra of the surface 10A of the glass substrate 10 that is further outward than the peripheral area is preferably 0.5 nm or less, more preferably less than 0.5 nm, further preferably less than 0.3 nm, and further preferably less than 0.3 nm, and the arithmetic mean roughness Ra of the peripheral area is within the above-mentioned preferred range. Specifically, in the use of a glass substrate for an image sensor, by making the arithmetic mean roughness Ra of the area on the surface 10A that is further outward than the peripheral area 0.3 nm and making the Ra of the peripheral area 1.0 nm, laser processing can be easily performed and the Ra of the area used as a substrate can be well maintained.

[0093] (composition)

[0094] The glass substrate 10 may have any composition in which the parameter y is within the above range. Examples of the composition of the glass substrate 10 will be described below.

[0095] The glass substrate 10 may contain the following compounds, for example, in terms of mass % (wt %) based on oxides.

[0096] SiO2: preferably 40% to 70%, preferably 50% to 65%.

[0097] Al2O3: preferably 0wt% to 25wt%, more preferably 5wt% to 25wt%.

[0098] B2O3: preferably 0wt% to 20wt%, more preferably 0wt% to 15wt%.

[0099] MgO: preferably 0 wt% to 20 wt%, more preferably 0 wt% to 15 wt%.

[0100] CaO: preferably 0 wt% to 25 wt%, more preferably 1 wt% to 15 wt%.

[0101] SrO: preferably 0 wt% to 25 wt%, more preferably 0 wt% to 15 wt%.

[0102] BaO: preferably 0 wt% to 40 wt%, more preferably 0 wt% to 30 wt%.

[0103] Na2O: preferably 0wt% to 20wt%, more preferably 0wt% to 15wt%.

[0104] K2O: preferably 0 wt% to 15 wt%.

[0105] (Method for manufacturing glass substrate)

[0106] The manufacturing method of the glass substrate 10 in the present embodiment includes: a preparation step of preparing a glass plate as a glass substrate before forming the mark 100, and an irradiation step of manufacturing the glass substrate 10 by irradiating the surface of the glass plate with a laser to form the mark 100. In the preparation step, after melting the glass raw material, the glass raw material is made into a glass state by using any glass forming technology such as a float method, a melting method, and an ingot molding to manufacture a glass plate, and then processed into the shape of a glass substrate. In the example of the present embodiment, since the glass substrate is in the shape of a circular plate, the glass is cut into a circle by any method such as cutting and circular cutting to form a circular glass plate. The glass plate cut into a circle is subjected to chamfering of the end face and grinding and polishing of the surface. Here, when the Ra near the area where the point is formed deviates from the preferred range, the target area can be additionally processed. That is, after the grinding and polishing of the surface, the target area can be subjected to additional surface treatment such as local grinding, liquid processing, etc. at any time before the processing using the laser. For example, local grinding includes: additional grinding of the area near the imprint using a grinding pad with a smaller head, and surface micro-processing using a liquid such as hydrofluoric acid, laser, or plasma. By performing such local treatment, it is possible to form dots 104 using laser processing even on a glass substrate that is not easy to process with a laser. The glass plate that has undergone the designed process is further subjected to a cleaning and inspection process to achieve the desired Ra, completing the preparation step. In the irradiation step, the surface of the glass plate is repeatedly irradiated with a laser to form dots 104, and a mark 100 consisting of a plurality of dots 104 is formed on the surface of the glass plate. When irradiating with a laser, a metal film or a resin film with a high absorption coefficient may also be applied to facilitate processing with a laser or to prevent the adhesion of scattered objects.

[0107] In the irradiation step, the glass surface is irradiated with laser to form a spot 104. The laser uses, for example, a light source with a wavelength of 532 nm, and is irradiated to the glass surface by the light source through various optical instruments. The spot diameter can be adjusted by an optical system to a spot diameter of about 100 μm. The glass surface can be moved in the xy direction using a scanner, or an xy stage or the like.

[0108] (Effect)

[0109] As described above, in the glass substrate 10 according to the first aspect of the present disclosure, the mark 100 is provided on the surface 10A, and the parameter y defined by the formula (1) is smaller than 1.4.

[0110] Here, when a mark is formed on the glass substrate, cracks may be generated starting from the mark and break at the crack starting point. In this regard, the inventors conducted in-depth research and found that the generation of cracks is related to the average thermal expansion coefficient C, glass transition temperature Tg, density ρ, Young's modulus E, thermal conductivity λ and arithmetic mean roughness Ra (surface roughness) of the surface 10A, and cracks can be suppressed by making the parameter y within a specified range. That is, the glass substrate 10 of this embodiment suppresses the generation of cracks starting from the mark by making the parameter y less than 1.4, and as a result, cracks can be suppressed.

[0111] The glass substrate 10 of the second embodiment of the present disclosure is the glass substrate 10 of the first embodiment, and the arithmetic mean roughness Ra prescribed by JIS B0601:2001 around the marking of the surface 10A of the glass substrate 10 is preferably 0.3 nm or more and less than 1.7 nm. By setting the arithmetic mean roughness Ra within this range, the generation of cracks can be more appropriately suppressed.

[0112] The glass substrate 10 of the third embodiment of the present disclosure is the glass substrate 10 of the first or second embodiment, and the average thermal expansion coefficient of the glass substrate 10 at 50° C. to 200° C. is preferably 3 ppm / ° C. or more and less than 12.1 ppm / ° C. By setting the average thermal expansion coefficient to be within this range, the occurrence of cracks can be more appropriately suppressed.

[0113] The glass substrate 10 of the fourth aspect of the present disclosure is any one of the glass substrates 10 of the first to third aspects, and the glass transition temperature of the glass substrate 10 is preferably 500° C. to 800° C. By setting the glass transition temperature to this range, the generation of cracks can be more appropriately suppressed.

[0114] The glass substrate 10 of the fifth aspect of the present disclosure is any one of the glass substrates 10 of the first to fourth aspects, and the density of the glass substrate 10 is preferably 2.4 g / cm 3 ~3.5g / cm 3 By setting the density to be within this range, the occurrence of cracks can be more appropriately suppressed.

[0115] The glass substrate 10 of the sixth aspect of the present disclosure is any one of the glass substrates 10 of the first to fifth aspects, and the Young's modulus of the glass substrate 10 is preferably 71 GPa or more. By setting the Young's modulus to be within this range, the occurrence of cracks can be more appropriately suppressed.

[0116] The glass substrate 10 of the seventh aspect of the present disclosure is any one of the glass substrates 10 of the first to sixth aspects, and the thermal conductivity of the glass substrate 10 is preferably greater than 0.8 W / m·° C. When the thermal conductivity is within this range, the occurrence of cracks can be more appropriately suppressed.

[0117] The glass substrate 10 of the eighth aspect of the present disclosure is any one of the glass substrates 10 of the first to seventh aspects, and preferably has a thickness variation of 3 μm or less. When the thickness variation is within this range, a device or the like can be appropriately supported.

[0118] The glass substrate 10 of the ninth aspect of the present disclosure is any one of the glass substrates 10 of the first to eighth aspects and is disk-shaped with a diameter of 300 mm or less and a thickness of 0.3 mm to 2.0 mm, and may have a notch N formed on the outer peripheral surface.

[0119] In addition, the glass substrate 10 of the 10th embodiment of the present disclosure is any glass substrate 10 of the 1st to 8th embodiments and can be a rectangular plate with a maximum value of 300 mm to 1000 mm in distance between any two points on the outer periphery and a thickness of 0.5 mm to 2.0 mm. The glass substrate 10 can appropriately support devices and the like by being in such a shape.

[0120] Here, the area between the position deviating 1mm from the periphery to the radial inside and 5mm from the periphery to the radial inside in the entire domain of the glass substrate 10 is regarded as the outer area. In addition, the area surrounded by a square with a center point O of the glass substrate 10 as the center and one side of 100mm in the entire domain of the glass substrate 10 is regarded as the central side area. In this case, the average value of the thickness D of the glass substrate 10 in the outer area can be greater than the average value of the thickness D of the glass substrate 10 in the central side area (that is, the center can be thicker). In addition, on the contrary, the average value of the thickness D of the glass substrate 10 in the outer area can be less than the average value of the thickness D of the glass substrate 10 in the central side area (that is, the center can be thinner). In addition, the deviation of the thickness D of the entire domain of the glass substrate 10 is preferably less than 1μm, and more preferably less than 0.5μm.

[0121] In addition, the thickness deviation of only the outer region of the glass substrate 10 is preferably 1 μm, more preferably 0.5 μm or less. In addition, the thickness deviation of only the inner region of the glass substrate 10 is preferably 1 μm, more preferably 0.5 μm or less. By using the glass substrate 10 with small thickness deviations in the outer region and the inner region, each process can be stably performed. In addition, by using a glass substrate 10 with a thin central portion, processes such as adsorption and film formation can be stably performed.

[0122] As a method for realizing such a shape with a thin or thick center, for example, in physical processing such as grinding, it is conceivable to increase the pressure at the center of the glass substrate 10 or to increase the relative speed of the grinding cloth. In addition, for example, in HF (hydrofluoric acid) etching, in order to selectively etch the center of the glass substrate 10, it is conceivable to shield the peripheral part, heat the center of the glass substrate 10, and adjust the liquid flow path in such a way that fresh liquid always contacts the center of the glass substrate 10.

[0123] When the glass substrate 10 is supported at three points, the sizes of WARP and BOW are preferably 200 μm or less, and more preferably 100 μm or less. When the glass substrate 10 is used in a semiconductor process, the directions of WARP and BOW are preferably aligned.

[0124] The glass substrate 10 may have a mark for direction identification. Only one mark is applied to the outer periphery of the glass substrate 10, but for direction management, there may be more than two marks, or they may be located in the central part of the glass substrate 10. In the case of a rectangular substrate, there may be more than one mark at an asymmetric position within the surface. In the case of a wafer shape but without a notch, or a square in a rectangular shape, the direction within the xy plane is unclear. By applying a mark having the function of an alignment mark to the glass substrate 10, the direction of the BOW and the direction within the xy plane can be managed. In the case of a rectangular substrate, for direction management, the corners are sometimes asymmetrically cut into acute angles or obtuse angles, but there is a risk of breakage of glass that has a vertex and is cut. By applying more than one alignment mark to the glass substrate 10, the shape of each corner can be formed into a symmetrical shape of the corner R. The R of the corner is preferably 0 mm to 20 mm, and more preferably 5 mm to 15 mm.

[0125] The glass substrate 10 is preferably chamfered at the periphery. The periphery is preferably further mirror-finished. The arithmetic mean roughness Ra of the periphery is preferably 0.1 μm or less, and more preferably 0.05 μm or less. The periphery is an end face, a chamfered portion, a notch in the case of a circular substrate, and all corners in the case of a rectangular substrate are processed to the same surface roughness. In order to adjust the film forming conditions and improve the accuracy of the end face detection, it can also be processed so that only a part of the periphery, only the notch portion, and only the corner portion have a larger surface roughness.

[0126] The glass substrate 10 of the eleventh aspect of the present disclosure is any of the glass substrates 10 of the first to tenth aspects and is preferably used as a glass substrate for supporting a semiconductor device. The glass substrate 10 of this embodiment can appropriately support a semiconductor device.

[0127] The glass substrate 10 of the 12th aspect of the present disclosure is any one of the glass substrates 10 of the 1st aspect to the 11th aspect, and the arithmetic mean roughness Ra specified in JIS B0601:2001 on the outer side of the periphery of the mark of the surface 10A of the glass substrate 10 is preferably 0.3 nm or less. By making the surface roughness on the outer side of the periphery of the mark smaller, breakage can be appropriately suppressed.

[0128] (Example)

[0129] Next, examples are described. Table 1 is a table showing various examples.

[0130] [Table 1]

[0131] (Table 1)

[0132]

[0133] In each example, glass plates having different physical properties and surface roughness were prepared as shown in Table 1, and glass substrates having a diameter of 300 mm and a thickness of 1.0 mm were prepared. It should be noted that samples polished under different polishing conditions (polishing condition 1, polishing condition 2) were prepared for glass substrates having the same physical properties.

[0134] For each glass substrate, the average thermal expansion coefficient C, glass transition temperature Tg, density ρ, Young's modulus E, thermal conductivity λ and arithmetic mean roughness Ra of the surface were measured. The measurement conditions used the method described in the above embodiment. The measurement results of each example are shown in Table 1. The arithmetic mean roughness Ra is a measured value of the peripheral area within a range of 5 mm from the point deviation.

[0135] In addition, for each glass substrate of each example, the average thermal expansion coefficient C cal , glass transition temperature Tg cal , density ρ cal , Young's modulus E cal , thermal conductivity λ cal The calculation conditions used the method described in the above embodiment. Table 1 shows the calculation results of each example.

[0136] In addition, for each glass substrate, the parameter y was calculated based on the measured average thermal expansion coefficient C, glass transition temperature Tg, density ρ, Young's modulus E, thermal conductivity λ and arithmetic mean roughness Ra of the surface. The values ​​of the parameter y of each example are shown in Table 1. It should be noted that the arithmetic mean roughness Ra is a different value under each polishing condition, so the arithmetic mean roughness Ra and the parameter y were measured and calculated under each polishing condition.

[0137] (evaluate)

[0138] The glass substrates of each example were irradiated with laser light having a wavelength of 532 nm multiple times to form double circular dots. The number of dots formed on one glass substrate was 1,300 to 2,500.

[0139] During the evaluation, it was observed whether cracks were generated starting from each point. Specifically, when the surface of the glass substrate 10 of each example was visually observed at a magnification of 50 times using a microscope (Keyence laser microscope), if there were cracks with a length of more than 10 μm starting from the point, it was judged to be cracked, and if there were no cracks with a length of more than 10 μm starting from the point, it was judged to be crack-free. Each point formed in the glass substrate 10 of each example was observed for the presence or absence of cracks, and for each glass substrate 10 of each example, the ratio of the number of points judged to have cracks to the total number of points was calculated as the crack generation rate. The crack generation rate is shown in Table 1.

[0140] As shown in Table 1, it can be seen that when the parameter y is 1.4 or more, for example, as shown in Example 9 as a comparative example, a sample with a crack generation rate exceeding 5% appears, but as shown in Examples 1 to 8 and 10 as embodiments, in all samples with parameter y less than 1.4, the crack generation rate is less than 5%. Thus, it can be seen that by making the parameter y less than 1.4, the crack generation rate is less than 5%, and the generation of cracks can be suppressed. In addition, as shown in each example, when the arithmetic mean roughness Ra is less than 0.3nm and is greater than 1.7nm, there is a tendency for the crack generation rate to increase. It can be seen that by making the arithmetic mean roughness Ra greater than 0.3nm and less than 1.7nm, the crack generation rate is kept low, which is more preferable.

[0141] The above describes the embodiments of the present invention, but the embodiments are not limited by the contents of the embodiments. In addition, the above-mentioned constituent elements include constituent elements that can be easily assumed by those skilled in the art, that are substantially the same, and that are so-called equivalent scopes. Furthermore, the above-mentioned constituent elements can be appropriately combined. In addition, various omissions, substitutions or changes of constituent elements can be made within the scope of the gist of the above-mentioned embodiments.

[0142] Explanation of symbols

[0143] 10 Glass Substrate

[0144] 10A Surface

[0145] 100 Marks

Claims

1. A glass substrate having a mark on its surface. The parameter y specified by the following formula (1) is less than 1.4, y=0.021·C-0.0034·Tg-0.012·ρ+0.020·E-2.814·λ-0.433·Ra+4.372···(1) in, C is the average thermal expansion coefficient of the glass substrate at 50°C to 200°C, in ppm / °C, Tg is the glass transition temperature of the glass substrate, in °C, ρ is the density of the glass substrate, in g / cm 3 , E is the Young's modulus of the glass substrate, in GPa, λ is the thermal conductivity of the glass substrate, in W / m·℃, Ra is the arithmetic mean roughness of the surface of the glass substrate as specified in JIS B 0601:2001, and the unit is nm.

2. The glass substrate according to claim 1, wherein The arithmetic mean roughness Ra of the periphery of the mark on the surface of the glass substrate as specified in JIS B 0601:2001 is 0.3 nm or more and less than 1.7 nm.

3. The glass substrate according to claim 1 or 2, wherein: The average thermal expansion coefficient of the glass substrate at 50° C. to 200° C. is greater than or equal to 3 ppm / ° C. and less than 12.1 ppm / ° C.

4. The glass substrate according to claim 1 or 2, wherein: The glass transition temperature of the glass substrate is 500°C to 800°C.

5. The glass substrate according to claim 1 or 2, wherein: The density of the glass substrate is 2.4 g / cm 3 ~3.5g / cm 3 .

6. The glass substrate according to claim 1 or 2, wherein: The glass substrate has a Young's modulus of 71 GPa or more.

7. The glass substrate according to claim 1 or 2, wherein: The thermal conductivity of the glass substrate is greater than 0.8 W / m·°C.

8. The glass substrate according to claim 1 or 2, wherein: The thickness variation was 3 μm or less. 9 . The glass substrate according to claim 1 , which is in the shape of a disk having a diameter of 300 mm or less and a thickness of 0.3 mm to 2.0 mm, and has a notch formed on the outer peripheral surface. 10 . The glass substrate according to claim 1 , which is in the shape of a rectangular plate, the maximum value of the distance between any two points on the outer periphery being 300 mm to 1000 mm, and the thickness being 0.5 mm to 2.0 mm.

11. The glass substrate according to claim 1 or 2, which is used as a glass substrate for supporting a semiconductor device.

12. The glass substrate according to claim 1 or 2, wherein: The arithmetic mean roughness Ra prescribed in JIS B 0601:2001 on the outer side of the periphery of the mark of the surface of the glass substrate is 0.5 nm or less.

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