WO2014017610A1 - Glass for coating metal substrate and metal substrate having glass layer attached thereto - Google Patents

Abstract

Provided is a glass for coating a metal substrate. The glass exhibits high heat resistance, crystallization and metal substrate warpage are suppressed during the formation of the glass into a glass layer, and an extremely flat upper surface can be imparted to the glass layer that is obtained. Also provided is a metal substrate having a glass layer attached thereto, the metal substrate being provided with the glass layer that exhibits high heat resistance and is extremely flat, and the entire substrate body exhibiting no warpage. The glass for coating a metal substrate contains, expressed as a mass percentage in terms of the oxides, 15-60% of SiO₂, 0-35% of B₂O₃, 0-15% of R₂O (R represents at least one element selected from the group consisting of Li, Na, and K), 25-55% of R'O (R' represents at least one element selected from the group consisting of Mg, Ca, Sr, Ba and Zn), and 0.1-7% of AI₂O₃, and satisfies (ZnO+MgO+CaO)/(SrO+BaO)<̳0.3. The metal substrate having a glass layer attached thereto is formed using the glass for coating a metal substrate.

Description

Glass for metal substrate coating and metal substrate with glass layer

The present invention relates to a glass for coating a metal substrate and a metal substrate with a glass layer, and particularly to a glass for insulatingly coating the surface of a metal substrate used for an electronic component and a metal substrate with a glass layer formed using the glass.

As an electronic component having an electronic circuit on a substrate, an electronic film is formed on a metal substrate with an insulating film formed on the metal substrate, depending on the processing conditions at the time of manufacture, the usage environment such as high temperature use, and the application. Parts may be used.
In this case, the glass layer formed on the metal substrate is usually equipped with various elements on the glass layer and provided with a circuit, so that high flatness is required on the surface and the entire substrate with the glass layer is used. There is a demand for no warpage.

In order to form a glass layer on a metal substrate, a method in which a glass paste layer containing glass and a binder component is formed on a metal substrate and fired is generally used. At this time, it is known that when the thermal expansion coefficients of the metal and the glass are greatly different, warping and cracking occur due to stress strain. In particular, in the production of a multilayer electronic circuit board, the laminated structure of the metal substrate and the glass layer is sequentially formed from the lower layer, so that the lower layer portion is repeatedly exposed to the firing temperature. As a result, the problem of warping and cracking is further exacerbated, and the reliability of the electronic component is impaired. Furthermore, as the heat resistance, for example, when a specific semiconductor layer is formed on the glass layer of the metal substrate with a glass layer as in the solar cell described in Patent Document 1, the heat resistance is 500 ° C. or more. Sometimes it is required.

In Patent Document 1, a metal substrate having a glass layer that can obtain a high insulation resistance even after a heat treatment of 500 ° C. or more to form a specific semiconductor layer, and further, a thermal expansion coefficient is adjusted to configure the glass layer The composition of the finished glass is described. However, since the glass described in Patent Document 1 is easily devitrified (crystallized), it is difficult to obtain a glass layer having a flat surface, and it is difficult to form a thin line pattern on the glass layer.

Japanese Unexamined Patent Publication No. 2006-80370

The present invention has a high heat resistance, crystallization is suppressed during the formation of the glass layer, suppresses the occurrence of warpage of the metal substrate, and can impart high flatness to the surface of the obtained glass layer. It aims at providing glass for substrate covering. It is another object of the present invention to provide a metal substrate with a glass layer that includes a glass layer having high heat resistance and surface flatness and has almost no warpage as the entire substrate.

The present invention is expressed in terms of mass percentage on the basis of oxide, and SiO ₂ is 15 to 60%, B ₂ O ₃ is 0 to 35%, R ₂ O (R is at least one selected from the group consisting of Li, Na and K) 0-15%, R′O (R ′ is at least one selected from the group consisting of Mg, Ca, Sr, Ba, and Zn) 25-55%, and Al ₂ O ₃ 0.1-7. %, And a glass for coating a metal substrate satisfying (ZnO + MgO + CaO) / (SrO + BaO) ≦ 0.3.

In the present invention, among the glass for coating a metal substrate of the above composition, SiO ₂ is 30 to 50%, B ₂ O ₃ is 10 to 25%, R ₂ O (R is O A glass containing 0 to 13% of at least one selected from the group consisting of Li, Na and K is preferred.
The metal substrate covering glass of the present _invention, the ratio of content of _{R 2 O / (SiO 2 +} B 2 O 3) is preferably 0.3 or less.
Furthermore, the glass for coating a metal substrate of the present invention has a glass transition point of 520 to 670 ° C., a glass softening point of 650 to 800 ° C., and an average thermal expansion coefficient α at 50 to 350 ° C. of 80 × 10 ^−7. It is preferably ^˜110 × 10 ⁻⁷ / ° C.

The present invention also provides a metal substrate with a glass layer having a metal substrate and a glass layer formed on at least a part of the surface of the metal substrate using the glass for covering a metal substrate of the present invention. In the metal substrate with a glass layer of the present invention, the surface roughness of the glass layer is preferably 0.10 μm or less, and the difference in average thermal expansion coefficient α between the metal and the glass at 50 to 350 ° C. is 30. It is preferable that the temperature is 10 ⁻⁷ / ° C. or less.

The glass for coating a metal substrate of the present invention has high heat resistance, is an amorphous glass, and hardly crystallizes when a glass layer is formed on the metal substrate. In addition, according to the glass for coating a metal substrate of the present invention, when the glass layer is formed on the metal substrate, the metal substrate is hardly warped, and the surface of the obtained glass layer has high flatness. Have. Therefore, a delicate electrode pattern can be formed on the surface of the glass layer on the metal substrate. Furthermore, by using the glass for covering a metal substrate of the present invention, the metal substrate with a glass layer of the present invention can be provided which has a glass layer having high heat resistance and surface flatness and hardly warps as a whole substrate.

It is a figure which shows roughly the measuring method of the curvature of the metal substrate with a glass layer.

Embodiments of the present invention will be described below. In addition, this invention is limited to the following description and is not interpreted.
[Metal substrate coating glass]
The composition of the glass for coating a metal substrate of the present invention is expressed in terms of mass percentage on the basis of oxide, and SiO ₂ is 15 to 60%, B ₂ O ₃ is 0 to 35%, R ₂ O (R is Li, Na and K At least one selected from the group consisting of: 0 to 15% in the present specification, and R′O (R ′ is selected from the group consisting of Mg, Ca, Sr, Ba and Zn). In the present specification, the same shall apply hereinafter) 25 to 55%, Al ₂ O ₃ 0.1 to 7%, and (ZnO + MgO + CaO) / (SrO + BaO) ≦ 0.3. Satisfied.

The glass of the present invention is for forming a glass layer provided to cover at least a part of the surface of a metal substrate. By setting it as the said composition, while the glass of this invention has sufficient heat resistance, about the thermal expansion coefficient, the thermal expansion coefficient of the metal (It is as mentioning later about a specific metal.) Which comprises a metal substrate. Can be adjusted to reduce the difference between Furthermore, the glass of the present invention is an amorphous glass, and has good meltability of raw materials in the melting step at the time of glass production, and is hardly crystallized when a glass layer is formed on a metal substrate.

The glass of the present invention has a glass transition point (hereinafter referred to as “Tg”) of 520 ° C. or higher and a glass softening point (hereinafter referred to as “Ts”) of 650 ° C. or higher in terms of heat resistance. Preferably there is. Furthermore, from the viewpoint of the heat resistant temperature of the metal substrate, Tg is preferably 670 ° C. or less, and Ts is preferably 800 ° C. or less. Further, regarding the thermal expansion coefficient of the glass of the present invention, the average thermal expansion coefficient α at 50 to 350 ° C. is 80 × 10 ⁻⁷ to 110 × in consideration of suppressing the induction of warpage of the metal substrate as much as possible. It is preferably 10 ⁻⁷ / ° C.
Tg is a temperature at which the glass structure changes, and is a temperature at which the viscosity becomes 10 ^13.3 (dPa · s). Tg and Ts can be measured by a differential thermal analysis (DTA) apparatus. Further, in this specification, unless otherwise specified, the thermal expansion coefficient means an average thermal expansion coefficient at 50 to 350 ° C.

Hereinafter, each component of the glass of the present invention will be described. In the following description, the contents of glass components are all expressed in terms of oxide based mass percentage.
SiO ₂ is a component that stabilizes the glass and is an essential component. When the content of SiO ₂ is less than 15%, Ts becomes too low, and it becomes difficult to sufficiently increase the heat resistant temperature of the glass layer in the obtained metal substrate with a glass layer. If the heat resistance temperature of the glass layer is not at a sufficiently high level, it is difficult to form an electric circuit or the like on the glass layer. If the SiO ₂ content exceeds 60%, Ts becomes too high. If Ts is higher than necessary, the firing temperature at the time of forming the glass layer set to be equal to or higher than Ts may exceed the heat resistance temperature of the metal substrate, and the metal substrate may be deformed. The content of SiO ₂ is particularly preferably 30 to 50% in the above range.

The component represented by R′O, that is, at least one selected from the group consisting of ZnO, MgO, CaO, SrO, and BaO is an essential component as a component for adjusting the thermal expansion coefficient. If the total content of R′O is less than 25%, the thermal expansion coefficient is lowered and warpage is induced in the metal substrate with a glass layer. If the total content of R'O exceeds 55%, the glass becomes unstable and partially crystallizes and devitrifies. In addition, as a relationship of each component in the component represented by R′O, the content ratio of (ZnO + MgO + CaO) / (SrO + BaO) is preferably 0.3 or less. When this ratio exceeds 0.3, the thermal expansion coefficient is lowered. ZnO is preferably 0 to 3%. If ZnO exceeds 3%, the thermal expansion coefficient tends to decrease, and it becomes difficult to adjust the thermal expansion coefficient to a desired range as a whole R′O.

B ₂ O ₃ is a component that stabilizes the glass, and is an optional component that is preferably contained. When the content of B ₂ O ₃ exceeds 35%, the softening point becomes too high, and the problem that occurs due to the high Ts as described above is induced. The content of B ₂ O ₃ is preferably 10 to 25%.

The alkali metal oxide represented by R ₂ O is a component having a function of facilitating vitrification, a function of decreasing Ts, a function of increasing the thermal expansion coefficient, and the like, and is an optional component that is preferably contained. If the total content of R ₂ O exceeds 15%, Ts becomes too low, and a problem occurs when Ts is low as described above. The total content of R ₂ O is preferably 13% or less.
The ratio of the content of R ₂ O / (SiO ₂ + B ₂ O ₃ ) is preferably 0.3 or less. This is because if R ₂ O / (SiO ₂ + B ₂ O ₃ ) exceeds 0.3, Ts tends to be lowered, and the problem that occurs when Ts is low as described above is likely to be induced. Here, R ₂ O is the total content of R ₂ O.

Al ₂ O ₃ is a component that lowers the coefficient of thermal expansion and increases the stability and chemical durability of glass, and is essential. When the content of Al ₂ O ₃ exceeds 7%, the viscosity of the glass increases, and the problem that Al ₂ O ₃ remains as an unmelted material in the glass is induced. If it is less than 0.1%, the glass becomes unstable and partially devitrified.

The glass of the present invention basically preferably contains the above components, but can contain other components other than the above components as long as the effects of the present invention are not impaired. For _{example, TiO 2, ZrO 2, V} 2 O 5, CeO 2, La 2 O 3, SnO 2, CuO, NiO, MnO, CoO, Fe 2 O 3, Bi 2 O 3, Cr 2 O 3, In 2 O ₃ , at least one selected from the group consisting of Ag ₂ O, MoO ₃ , Nb ₂ O ₃ , Ta ₂ O ₅ , Ga ₂ O ₃ , Sb ₂ O _{3 and the} like. In that case, the total content of the other components is preferably 10% or less. Among these, TiO ₂ and ZrO ₂ are components that contribute to glass stabilization and are preferably used. However, if the content of TiO ₂ exceeds 4% or the content of ZrO ₂ exceeds 1.6%, it becomes unstable and becomes partially devitrified. Therefore, when TiO ₂ and / or ZrO ₂ is contained in the glass, the upper limit value is set.

The glass of the present invention contains substantially no lead compound such as PbO. This reduces the load on the environment. In addition, in this specification, the glass which does not contain a lead compound substantially refers to the glass whose content of lead compounds, such as PbO in a glass composition, is 1000 ppm (mass parts per million display) or less.

In the present invention, among the glasses having such a composition, SiO ₂ is 30 to 50%, B ₂ O ₃ is 10 to 25%, and R ₂ O is 0 to 13% in terms of mole percentage based on oxide. Further, a glass containing 25 to 55% of R′O, 0.1 to 7% of Al ₂ O ₃ and satisfying (ZnO + MgO + CaO) / (SrO + BaO) ≦ 0.3 is particularly preferable.

When the glass of the present invention has the above composition, the above-mentioned preferable characteristics, specifically, amorphous, Tg is 520 to 670 ° C., Ts is 650 to 800 ° C., and the thermal expansion coefficient is 80 ×. A characteristic of 10 ⁻⁷ to 110 × 10 ⁻⁷ / ° C. can be achieved.

The glass of the present invention can be produced by an ordinary glass production method, for example, a melting method. Specifically, it can be produced by mixing and mixing glass raw materials so as to have the above composition, melting at about 1300 to 1600 ° C., and then cooling and solidifying. Although the form of the glass of the present invention is not particularly limited, the glass obtained above is usually pulverized and used as a glass powder for coating a metal substrate. The pulverization can be performed using a pulverizer such as a roll mill, a ball mill, or a jet mill.

When the glass of the present invention is a powder, 50% particle diameter _{(hereinafter,} referred to as _{D 50.)} Is preferably from 0.1 ~ 100 [mu] m. If D ₅₀ of the glass is less than 0.1 [mu] m, industrially and difficult manufacture and made for easily aggregate, it is difficult to handle. _{D 50} of the glass is more preferably 0.3μm or more, and still more preferably 0.5μm or more. On the other hand, if D ₅₀ exceeds 100 [mu] m, the softening of the entire glass becomes insufficient, the uniformity of the glass layer in the glass layer coated metal substrate obtained may not be sufficient. Therefore, D ₅₀ of the glass powder is more preferably 10 μm or less, and further preferably 6 μm or less. The particle size can be adjusted, for example, by classification as necessary after pulverization. Incidentally, D ₅₀ in the present specification is a value measured by a laser diffraction scattering method.

The metal substrate on which the glass layer is formed on at least a part of the surface of the glass of the present invention is not particularly limited. For example, a metal substrate or the like that requires an insulating coating used for an electronic component can be used. The metal constituting the metal substrate is preferably a metal having a difference in thermal expansion coefficient between the metal and the glass of 30 × 10 ⁻⁷ / ° C. or less. More preferably, a metal having a thermal expansion coefficient equal to or lower than the thermal expansion coefficient of the glass of the present invention is preferable.

Specific examples of such metals include ferritic stainless steel (100 to 120), titanium alloy (84 to 88), nickel steel (94 to 100), carbon steel (100 to 130), and the like. The numbers in parentheses after each metal are the thermal expansion coefficient, and the unit is × 10 ^-7 / ° C.

[Metal substrate with glass layer]
The metal substrate with a glass layer of the present invention has a metal substrate and a glass layer formed on the surface of at least a part of the metal substrate using the glass for coating a metal substrate of the present invention.
Although it does not specifically limit as a metal substrate, The metal substrate similar to having demonstrated above is mentioned preferably. On the surface of the metal substrate, the region for forming the glass layer may be the whole of both main surfaces, the whole of one main surface, or a part of one main surface as necessary. May be. Moreover, all or a part of one main surface and a part of the other main surface may be sufficient. The shape of the glass layer forming region is not particularly limited.

The thickness of the glass layer of the metal substrate with a glass layer of the present invention is not particularly limited. It can set similarly to the thickness of the glass layer of the metal substrate with a glass layer normally used for an electronic component etc. Specifically, the thickness is about 10 to 100 μm. By setting the thickness of the glass layer within this range, it is possible to insulate the metal substrate from the electronic component and the like, which is preferable.

The surface roughness of the glass layer of the metal substrate with a glass layer of the present invention is preferably 0.10 μm or less. The surface roughness is arithmetic average roughness (Ra), and the value of Ra is represented by 3 “Definition and display of defined arithmetic average roughness” of JIS B0601 (1994). The surface of the glass layer may be, for example, at least Ra within the above-mentioned range in the mounting region of the element mounted on the metal substrate with the glass layer or the formation region of the circuit provided depending on the use. More preferably, Ra is within the above range.

In the metal substrate with a glass layer of the present invention, it is preferable that a shape difference due to warpage resulting from the formation of the glass layer does not occur with respect to the required shape. For example, the main surface is required to be horizontal over the entire metal substrate with a glass layer. In this case, although depending on the size of the metal substrate with a glass layer, there is no warp such that the difference between the maximum value and the minimum value of the main surface of the metal substrate with the glass layer from the horizontal plane is 400 μm or less. preferable.

The metal substrate with a glass layer of the present invention can be produced by a conventional method using the glass of the present invention. For example, by preparing a glass paste containing the glass of the present invention, applying the obtained glass paste to a predetermined region on the surface of a metal substrate to form a glass paste layer, and then firing this to form a glass layer Can be manufactured.

The glass paste is usually obtained by preparing the glass of the present invention as a glass powder as described above, and adding a vehicle composed of a binder resin and an organic solvent to the glass powder to prepare a paste. The glass paste is made into a glass paste layer on the metal substrate, and then becomes a glass layer by firing. A vehicle, ie, a mixture of a binder resin and an organic solvent, is a component for adjusting a viscosity suitable for supplying a glass paste in a layer form on a metal substrate. The type and blending amount are appropriately selected. The mixing ratio of the vehicle and the glass is also appropriately selected according to the method of supplying the glass paste onto the metal substrate, the supply device, and the like. In addition, the component which comprises a vehicle is a component which lose | disappears in manufacturing processes, such as temporary baking and baking, and does not remain | survive in a glass layer, after glass paste is supplied in a layer form on a metal substrate.

In addition, the component remaining after firing in the glass paste, that is, the component constituting the glass layer of the metal substrate with a glass layer of the present invention may be composed only of glass, and additives having various functions as other components. May be included. Examples of other components include inorganic oxide powder as an additive having a function of adjusting a thermal expansion coefficient. An inorganic oxide powder can be mix | blended in the ratio to 15 mass parts with respect to 100 mass parts of total amounts of the glass and inorganic oxide powder of this invention, for example.
Even when the glass layer of the metal substrate with a glass layer of the present invention contains an inorganic oxide powder, the thermal expansion coefficient of the entire material constituting the glass layer is the same as the range of the thermal expansion coefficient of the glass of the present invention. A range of 80 × 10 ⁻⁷ to 110 × 10 ⁻⁷ / ° C. is preferable.

Examples of the inorganic oxide powder include inorganic fillers and heat-resistant pigments. Examples of the inorganic filler include powders such as alumina, mullite, zircon, zirconia, cordierite, aluminum titanate, β-spodumene, α-quartz, quartz glass, β-quartz solid solution, β-eucryptite, and zirconium phosphate. Is mentioned. Examples of the heat-resistant pigment include white pigments such as titania, black pigments such as Fe—Mn complex oxide, Fe—Co—Cr complex oxide, and Fe—Mn—Al complex oxide.

The shape of the inorganic oxide powder is not particularly limited, and examples thereof include a spherical shape, a plate shape, a crushed shape, and a whisker shape. D ₅₀ of the inorganic oxide powder is preferably 0.3 to 20 μm, more preferably 0.5 to 10 μm. The D ₅₀ of the inorganic oxide powder is easy to handle if the above-mentioned range. Furthermore, it is excellent in operability and workability when it is made into a glass paste, and is also effective in dispersibility in glass.

The glass paste used for forming the glass layer may further contain known additives in ordinary glass pastes such as an antifoaming agent and a dispersing agent. These additives, like the vehicle, are usually components that disappear during the firing process. The glass paste can be adjusted by stirring and mixing a mixture of glass and vehicle (binder resin and organic solvent), which are essential components, and an appropriate amount of optional components such as inorganic oxide powder. Stirring and mixing are performed by a known method using a rotary mixer equipped with a stirring blade, a roll mill, a ball mill, or the like.

In order to form a glass paste layer on a metal substrate using a glass paste, for example, a printing method such as screen printing, gravure printing or metal mask printing is applied to the metal substrate, or a dispenser or the like is used. Methods such as a coating method and a blade coating method are applied. The thickness and shape of the glass paste layer are adjusted so that the glass layer finally obtained has a predetermined thickness and shape.

Next, heat treatment is performed in the glass baking temperature region contained in the glass paste, but before that, a step of drying the glass paste layer may be provided. This drying step is preferably performed in order to remove the organic solvent in the glass paste layer. If the organic solvent remains in the glass paste layer, there is a possibility that components to be eliminated such as the binder resin cannot be sufficiently removed in the heating process.

Next, heat treatment is performed in the baking temperature range of the glass contained in the glass paste. Here, the baking of the glass is required to be performed at a temperature equal to or higher than Ts of the glass. As the firing temperature region, a temperature region of Ts + 0 ° C. to Ts + 30 ° C. is preferable, and a temperature region of Ts + 10 ° C. to Ts + 20 ° C. is more preferable. In addition, heat processing are normally performed below the heat-resistant temperature of a metal substrate. The method for the heat treatment is not particularly limited as long as at least the temperature of the glass paste layer is the above temperature. Specific examples include thermal radiation heating, infrared heating, laser light irradiation, induction heating, and the like. Thermal radiation heating and laser light irradiation are preferably used from the viewpoint of temperature stability and manufacturing process costs.

When the heat treatment is performed by heat radiation heating using an electric furnace or the like, the heat treatment is mainly performed by removing the binder (such as pre-baking) to remove and remove components that should be lost, such as the binder resin, and glass. You may perform in two steps of the main baking for baking. By performing the heat treatment in two stages in this way, the amount of residual carbon is reduced and the growth of bubbles in the glass layer is suppressed, so that the smoothness of the glass layer surface is further improved. Heat treatment is more preferable.

The use of the glass substrate with a glass layer of the present invention is not particularly limited. Preferred examples include display elements such as (Field Emission Display), and electronic parts of piezoelectric vibrators such as MEMS (Micro Electro Mechanical Systems), IC packages, and quartz vibrators.

Hereinafter, examples of the present invention will be described. The present invention is not limited to these examples. Examples 1 to 15 are examples, and examples 16 to 18 are comparative examples.

[Examples 1 to 18]
(Manufacture of glass)
The glass raw materials were prepared and mixed so as to have the glass compositions shown in Table 1 (Examples 1 to 10) and Table 2 (Examples 11 to 18), and then used for 1 hour using a platinum crucible in an electric furnace at 1400 to 1500 ° C. melted, after forming the thin plate glass was pulverized by a ball _{mill, D 50} was obtained glass powder 1 to 18 1 ~ 3 [mu] m. For the obtained glass powders 1 to 18, Tg (glass transition point), Ts (glass softening point), glass crystallization peak temperature (hereinafter referred to as Tc) (unit: ° C.), and thermal expansion coefficient ( (Unit: 10 ⁻⁷ / ° C.) was measured as follows.

(Tg, Ts and Tc)
About Tg, Ts, and Tc, about 50 mg of glass powder is packed in a platinum cell, measured using a differential thermal analyzer at a temperature rising rate of 10 ° C./min up to 1000 ° C., and the first inflection point is determined. Tg and the fourth inflection point were Ts. Further, Tc was an exothermic peak observed in a temperature range higher than Ts. In Tables 1 and 2, “none” means that Tc does not exist up to 1000 ° C.

(Coefficient of thermal expansion)
Regarding the thermal expansion coefficient α, a fired body obtained by pressure-molding a glass powder and firing it at a temperature 30 ° C. higher than Ts for 10 minutes is processed into a cylindrical shape having a diameter of 5 mm and a length of 2 cm. The thermal expansion coefficient was measured.

(Production of metal substrate with glass layer)
60 g of each glass powder obtained above was added to and mixed with 20 g of a vehicle (a mixture of butyl carbitol acetate and ethyl cellulose resin in a mass ratio of 9: 1) to prepare a glass paste. This is blade coated with a stainless steel substrate (SUS430: 50 × 50 mm, thickness 0.3 mm, average linear expansion coefficient: 110 × 10 ⁻⁷ / ° C.) with a space of 5 mm from the edges of the four sides of the substrate. The film was applied to a thickness of 10 to 50 μm.
After applying the paste, this is dried, and further held in a heating furnace adjusted to a temperature of Ts + (0 to 30 ° C.) of the glass powder for 30 minutes, and then cooled to cool the metal substrates 1 to 18 with the glass layer. Obtained. The following evaluations were performed on the obtained metal substrates 1 to 18 with a glass layer.

[Evaluation]
(Glass layer thickness)
About the obtained metal substrate with a glass layer, the thickness of the glass layer was measured using the surface roughness shape measuring machine (The Tokyo Seimitsu Co., Ltd. make, Surfcom 1400D). In the measurement, the surface with the glass layer was scanned from the portion of the metal substrate without the glass layer by 10 mm toward the center of the substrate, and the difference between the maximum value and the minimum value was the thickness of the glass layer.
(Surface roughness, Ra)
In the central part (range of 30 × 30 mm) of the glass layer of the obtained metal substrate with a glass layer, as Ra, using a surface roughness shape measuring machine (manufactured by Tokyo Seimitsu Co., Ltd., Surfcom 1400D), JIS B0601 ( (1994), 3 "Definition and display of defined arithmetic mean roughness" Ra was measured.

(Warpage of metal substrate with glass layer)
A surface roughness shape measuring machine (Surfcom 1400D, manufactured by Tokyo Seimitsu Co., Ltd.) was used for measuring the warpage of the metal substrate with the glass layer in the region of the obtained metal substrate with the glass layer. . In determining the warpage, each of the two diagonal lines in the region with the glass layer is scanned, and the difference between the maximum value and the minimum value of the displacement amount is determined for each, and the warpage index of the metal substrate with the glass layer is calculated. did.
FIG. 1 shows a schematic diagram of a method for measuring warpage. Fig.1 (a) is a top view of the metal substrate with a glass layer obtained above. 1 is a metal substrate, 2 is a glass layer. FIG. 1B shows a cross-sectional view (XX cross-sectional view) taken along the diagonal line of the metal substrate with a glass layer shown in FIG. In the cross-sectional view shown in FIG. 1 (b), from one end s to the other end e of the formation region of the glass layer 2 is a scan region by a surface roughness shape measuring instrument, and the maximum and minimum displacements thereof. The difference in values is indicated by H in FIG.
In the measurement on the two diagonal lines, “◯” indicates that the difference between the displacement amounts (H in FIG. 1B) is within 400 μm, and the difference between the displacement amounts is either one or both is 400 μm. Those exceeding the value were evaluated as “x”.
The evaluation results are shown in Table 1 and Table 2 together with the glass composition.

As can be seen from Tables 1 and 2, the glasses 1 to 15 of Examples 1 to 15 corresponding to Examples are different from the glasses 16 to 18 of Examples 16 to 18 corresponding to Comparative Examples. Glasses 1 to 15 of Examples 1 to 15 have a glass transition point of 520 to 670 ° C., a glass softening point of 650 to 800 ° C., and a thermal expansion coefficient of 80 × 10 ⁻⁷ to 110 × 10 ⁻⁷ / ° C. All the conditions are met.
Further, in the metal substrates with glass layers 1 to 15, Ra on the surface of the glass layer is 0.10 μm or less, and there is almost no warpage.

According to the present invention, the glass layer is formed on the metal substrate with high heat resistance and is hardly crystallized when the glass layer is formed on the metal substrate. In this case, it is possible to provide a glass for coating a metal substrate that hardly induces the warp of the metal substrate and can obtain high flatness on the surface of the obtained glass layer, and the metal substrate of the present invention. By using the glass for coating, it is possible to provide a metal substrate with a glass layer of the present invention having a glass layer having high heat resistance and surface flatness and almost no warpage as the whole substrate, which is useful for various electronic components. is there.
The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2012-167387 filed on July 27, 2012 are incorporated herein as the disclosure of the present invention. .

1 ... Metal substrate, 2 ... Glass layer

Claims (7)

1. In terms of mass percentage based on oxide, SiO ₂ is 15 to 60%, B ₂ O ₃ is 0 to 35%, and R ₂ O (R is at least one selected from the group consisting of Li, Na and K) is 0. Containing 15 to 15%, R′O (R ′ is at least one selected from the group consisting of Mg, Ca, Sr, Ba and Zn), 25 to 55%, Al ₂ O ₃ 0.1 to 7%, A glass for coating a metal substrate that satisfies (ZnO + MgO + CaO) / (SrO + BaO) ≦ 0.3.
2. Oxide-based mass percentage display, SiO ₂ 30-50%, B ₂ O ₃ 10-25%, R ₂ O (R is at least one selected from the group consisting of Li, Na and K) 0 The glass for coating a metal substrate according to claim 1, which contains -13%.
3. The glass for coating a metal substrate according to claim 1 or 2, wherein the ratio of the content of R ₂ O / (SiO ₂ + B ₂ O ₃ ) is 0.3 or less.
4. 2. The glass transition point is 520 to 670 ° C., the glass softening point is 650 to 800 ° C., and the average thermal expansion coefficient at 50 to 350 ° C. is 80 × 10 ⁻⁷ to 110 × 10 ⁻⁷ / ° C. 4. The glass for coating a metal substrate according to any one of items 1 to 3.
5. A metal substrate with a glass layer, comprising a metal substrate and a glass layer formed on at least a part of the surface of the metal substrate using the glass for coating a metal substrate according to any one of claims 1 to 4.
6. The metal substrate with a glass layer according to claim 5, wherein the glass layer has a surface roughness (Ra) of 0.10 µm or less.
7. The metal substrate with a glass layer according to claim 5 or 6, wherein a difference in average thermal expansion coefficient between the metal and the glass at 50 to 350 ° C is 30 × 10 ^-7 / ° C or less.

Images