Lead-free glass composition as well as glass composite material, glass paste and sealing structure bodies containing this glass composition

Abstract

A lead-free glass composition containing vanadium oxide, tellurium oxide, alkali metal oxide, iron oxide, barium oxide and tungsten oxide, but essentially no phosphorus oxide, wherein the lead-free glass composition further contains at least one of the following constituents: yttrium oxide, lanthanum oxide, cerium oxide, erbium oxide, ytterbium oxide, aluminium oxide and gallium oxide. wherein the proportion of tellurium oxide is 25 mol% or more and 43 mol% or less, expressed as the oxide TeO2; and wherein the proportion of alkali metal oxide is 4 mol% or more and 27 mol% or less, expressed as oxide R2O (R: alkali metal element), wherein the proportions (mol-%) of vanadium oxide, tellurium oxide, alkali metal oxide, iron oxide, barium oxide and tungsten oxide correspond to the following ratios, expressed as oxides: [V2O 5] < 2[R2O] + 6[Fe2O 3] + 2 [BaO] < 3.5 [V2O 5] ; [WHERE 3]< [BaO] < [R2O] + [Fe2O 3] < [V2O 5] < [TeO 2] + [R2O], und [R2O] < 6 [Fe2O3].

Description

Technical area

[0001] The present invention relates to a lead-free glass composition as well as a glass composite material, a glass paste and a sealing structural body containing this lead-free glass composition. Technical background

[0002] Heat-insulating multilayer vacuum glass panels used for window glass and the like, display panels such as plasma display panels, organic EL display panels, and fluorescent display tubes, as well as electrical / electronic components such as crystal resonators, ceramic IC packages, and semiconductor sensors, are formed by performing a sealing and bonding process using a glass composite material containing a low-melting-point glass composition and ceramic particles / beads. In most cases, the glass composite material is used in the form of a glass paste. The glass paste is applied to the substrate by a screen printing and spreading method, and after drying, is subjected to a heat treatment to achieve sealing and bonding.In such a sealing and bonding process, the low melting point glass composition, which has a softened fluidity state, is in close contact with the element to be sealed or bonded.

[0003] A low-melting-point PbO-B2O3-based glass composition with a high lead oxide content is widely used as a low-melting-point glass composition. The low-melting-point PbO-B2O3-based glass composition has a low softening point in the range of 350°C to 400°C, exhibits excellent softened fluidity in the temperature range of 400°C to 450°C, and exhibits relatively high chemical stability. However, recent trends toward "green procurement and design" are increasingly demanding materials that offer higher safety. In Europe, the RoHS (Reduction of Hazardous Substances) Directive applies to electrical / electronic components, and six substances containing lead are designated as prohibited substances.Thus, new types of lead-free glass compositions with a low melting point are being developed.

[0004] Japanese Unexamined Patent Application JP 2010-184852 A describes low-melting-point glass with a softening point of 380°C or below, containing oxides of vanadium, phosphorus, tellurium, and iron. The low-melting-point glass also contains any oxides of manganese, zinc, tungsten, molybdenum, and barium.

[0005] Japanese Unexamined Publication JP 2012 - 96 993 A describes a lead-free low melting point glass composition containing 25 to 50 mass% V2O5, 5 to 30 mass% BaO, 20 to 40 mass% TeO2, 1 to 25 mass% WO3 and 0 to 20 mass% P2O5, expressed as the oxide of the component.

[0006] JP 2011-241 138 A discloses a photocatalytic glass-ceramic containing a crystal of the formula AmB2(XO4)3, where A is selected from Li, Na, K, Cu, Ag, Mg, Ca, Sr, and Ba, B is selected from Zn, Al, Fe, Ti, Sn, Zr, Hf, V, Nb, and Ta, X is selected from Si, Ge, P, S, MO, and W, and m is from 0 to 3. The glass-ceramic may contain, for example, V2O5 and TeO2. All examples contain 25 or more mol% of P2O5 and do not contain V2O5 and TeO2.

[0007] DE 11 2016 004 340 T5 discloses glass compositions comprising vanadium oxide, silver oxide, and tellurium oxide, wherein the total content of V2O5, TeO2, and Ag2O is at least 75 mass%. Furthermore, BaO, WO3, and / or P2O5 may be additionally included as a first additional component, and Y2O3, La2O3, Al2O3, and / or Fe2O3 may be additionally included as a second additional component. Summary

[0008] Heat-insulating, multi-layer vacuum glass panes require a highly reliable, airtight seal or bonding portion. The adhesion properties, or the achievement of close contact, are evaluated by determining whether leakage and delamination occur in the seal or bonding portion using a highly accelerated stress test (HAST) in an unsaturated state under the following conditions: temperature set at 120°C, humidity set at 85%, and pressure set at 2 atm.In the bonded state and bonded to the glass substrate, for example, soda-lime glass and borosilicate glass, the ceramic substrate, for example, alumina, aluminum nitride and silicon nitride, as well as the silicon substrate, the glass composite material and the glass paste prepared using the lead-free, low-melting-point glass composition described in, for example, Japanese Unexamined Patent Application Nos. JP 2010 - 184 852 A and JP 2012 - 96 993 A, are likely to cause exfoliation from an adhesive interface during HAST, so that excellent bonding and close contact properties cannot be ensured.

[0009] The material described above is required to be applied to an air-quenched or chemically strengthened glass substrate. Therefore, there is a strong need to lower the sealing and bonding temperatures. It is advantageous to bond and seal at the lowest possible temperature, for example, 370°C or below.

[0010] An object of the present invention is to provide a lead-free glass composition that ensures excellent bonding and intimate contact with the substrate at 370°C or below. Furthermore, a glass composite material containing the lead-free glass composition, a glass paste, and a sealing structural body are to be provided.

[0011] The lead-free glass composition of the present invention contains vanadium oxide, tellurium oxide, alkali metal oxide, iron oxide, barium oxide, and tungsten oxide, while substantially containing no phosphorus oxide. It further contains at least one of the additional components yttrium oxide, lanthanum oxide, cerium oxide, erbium oxide, ytterbium oxide, aluminum oxide, and gallium oxide. The tellurium oxide content is 25 mol% or more and 43 mol% or less, expressed as TeO2. The alkali metal oxide content is 4 mol% or more and 27 mol% or less, expressed as oxide R2O (R: alkali metal element). Furthermore, the proportions (mol%) of vanadium oxide, tellurium oxide, alkali metal oxide, iron oxide, barium oxide, and tungsten oxide correspond to the following ratios, expressed as oxides: [V2O 5] < 2 [R2O] + 6 [Fe2O 3] + 2 [Ba0] < 3.5 [V2O5]; [WHERE 3] < [BaO] < [R2O] + [Fe2O 3] < [V2O 5] < [TeO 2] + [R2O] , and [R2O] < 6 [Fe2O3] ; and / or the proportions (mol%) of the additional components, expressed as oxides, correspond to the following relationship: 2 [R2O] + 6[Fe2O 3] + 2 [BaO] + 6 [Y2O3] + 6 [La2O 3] + 4 [CeO 2] + 6 [Er2O3 + 6 [Yb2O3] + 6 [Al2O3] + 6 [Ga2O3] < 3.5 [V2O5].

[0012] According to the invention, the lead-free glass composition is provided with excellent adhesion and close contact with the substrate, enabling bonding and sealing at 370°C or below. Further, a glass composite material containing the lead-free glass composition, a glass paste, and a sealing structural body are provided. Short description of the drawings Fig. Figure 1 shows an example of a representative differential thermal analysis (DTA) curve, which represents a special feature of the glass. Fig.Figure 2 shows a representative example of a thermal expansion curve of a lead-free, low melting point glass composition. Fig. 3A shows a schematic plan view of a sealing structural body according to a first embodiment. Fig. Figure 3B shows a cross section along line AA of Fig. 3A. Fig. 4 explains the method for manufacturing the sealing structural body according to the first embodiment. Fig. 5 explains the method for manufacturing the sealing structural body according to the first embodiment. Fig. 6A shows a schematic plan view of a heat-insulating multilayer vacuum glass pane according to a third embodiment. Fig. 6B is a cross section along the line AA of Fig. 6A. Fig.7A shows a part of the method for manufacturing the heat-insulating multi-layer vacuum glass panel according to the third embodiment. Fig. Figure 7B shows a cross section along line AA of Fig. 7A. Fig. Figure 8A shows a schematic top view of an air quenched strengthened soda-lime glass substrate. Fig. Figure 8B shows a cross section along line AA of Fig. 8A. Fig. 9 is a cross-sectional view showing a state in which the heat-insulating vacuum multi-layer glass panel is in the manufacturing process according to the third embodiment. Fig. 10 shows a sealing temperature profile obtained in the method for manufacturing the heat-insulating multilayer vacuum glass panel according to the third embodiment. Fig.11A shows a schematic plan view of an organic light-emitting diode (OLED) display according to a fourth embodiment. Fig. Figure 11B shows a cross section along line AA of Fig. 11A. Fig. 12A shows a schematic plan view of the OLED display according to the fourth embodiment. Fig. Figure 12B shows a cross section along line AA of Fig. 12A. Fig. 13A shows a schematic plan view of the OLED display according to the fourth embodiment. Fig. Figure 13B shows a cross section along line AA of Fig. 13A. Fig. 14 is a schematic cross-sectional view showing a part of the method for manufacturing the OLED display according to the fourth embodiment. The Fig.15A to 15F are schematic cross-sectional views each showing the method of manufacturing a crystal resonator package according to a fifth embodiment. Fig. 16 shows a schematic cross-sectional view of a crystal resonator package according to the fifth embodiment. Detailed description of the embodiments

[0013] Embodiments of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to the embodiments described below. Lead-free glass composition with low melting point

[0014] Generally, the lower the characteristic temperature values ​​of the glass contained in the glass composition, such as the transition temperature, yield strength, and softening temperature, the better the softening fluidity at low temperatures. If the characteristic temperature is excessively lowered, a higher degree of crystallization tendency results. This can easily lead to crystallization during the heating / firing process. Crystallization can impair the softening fluidity at low temperatures. In general, glass with a lower characteristic temperature tends to have impaired chemical stability, such as moisture resistance, water resistance, acid resistance, alkali resistance, and salt water resistance, which poses an increasing burden on the environment.

[0015] Based on extensive investigations, the inventors have discovered a lead-free low-melting point glass composition containing substantially no lead, which composition has better low-temperature softening fluidity than the conventionally used PbO-B2O3-based low-melting point glass composition, as well as excellent chemical stability, favorable adhesion properties, and close contact with an arbitrary substrate (sealed device, adhesion member, and the like).

[0016] The lead-free low-melting-point glass composition contains vanadium oxide (V2O5), tellurium oxide (TeO2), alkali metal oxide (R2O, where R represents an alkali metal element), iron oxide (Fe2O3), barium oxide (BaO), and tungsten oxide (WO3), as well as at least one of the following: yttrium oxide (Y2O3), lanthanum oxide (La2O3), cerium oxide (CeO2), erbium oxide (Er2O3), ytterbium oxide (Yb2O3), aluminum oxide (Al2O3), and gallium oxide (Ga2O3), while essentially containing no phosphorus oxide. The term "lead-free" as used herein refers to the condition that the amount of this prohibited substance is equal to or less than the value specified in the aforementioned RoHS Directive (effective date: July 1, 2006). In the case described above, lead (Pb) may be present in an amount of 1000 ppm or less.The expression “essentially free from phosphorus oxide” means that phosphorus oxide is not intentionally added to the glass composition.

[0017] The following describes the functions of the main components of the above-described lead-free low-melting-point glass composition, namely V2O5, TeO2, R2O, Fe2O3, BaO, and WO3. The glass structure composed of these main components includes a layered structure formed by V2O5 and TeO2. R2O, Fe2O3, and BaO are present between the layers, and WO3 is present in the layer. It is assumed that the components R2O, Fe2O3, and BaO are combined with V2O5 between the layers, which constitutes the layered structure. The component TeO2 is a vitrifying component for vitrification in the glassmaking process. Therefore, TeO2 is an indispensable component for glass formation. When the content of TeO2 is small, it is difficult to suppress the crystallization tendency. On the other hand, when the content of TeO2 is large, it is difficult to lower the characteristic temperature.Therefore, it is effective to set the TeO2 content to 25 mol% or more and 43 mol% or less. Preferably, the V2O5 content is 30.5 mol% or more and 45 mol% or less.

[0018] The R2O component present between the layers of the layered structure composed of V2O5 and TeO2 serves to reduce the interlayer force and also lower characteristic temperatures such as the transition temperature, yield strength, and softening temperature. As the content increases, the temperature can be reduced more effectively. This component also serves to improve adhesion and close contact with various substrates. As the content increases, the achieved effect can become greater. However, if the content becomes too large, the problem of deterioration of chemical stability may arise. This may also cause the thermal expansion coefficient to become so large that it cannot match the individual thermal expansion coefficients of the corresponding substrates (elements to be sealed and adhered).Therefore, the content of R2O is set to 4 mol% or more and 27 mol% or less, and preferably 12 mol% or more and 27 mol% or less. It is possible to use Li2O, Na2O, and K2O as the alkali metal oxide R2O. When the content is low, in the range of 4 mol% to 27 mol%, it is preferable to use K. + -ions (K2O) with a large ionic radius. If the proportion is high in the range described above, it is preferable to use Li + -ions (Li2O) with a small ionic radius, with regard to chemical stability, characteristic temperature and thermal expansion coefficient.

[0019] The Fe2O3 component present between the layers serves to improve adhesion and close contact with R2O and also serves to improve chemical stability. However, if the proportion is excessively high, the problem of an increase in the characteristic temperature may occur, unlike the case of R2O. It is essential to keep the ratio between R2O and Fe2O3 at [R2O] < 6[Fe2O]. 3]from the perspective of chemical stability. As in the above case, BaO present between the layers serves to prevent and suppress adhesion failure due to devitrification (crystallization) upon heating of the glass. However, if the content is excessively high, a problem of impaired adhesion and close contact with the respective substrates may occur. The WO3 component present in the layer serves to improve vitrification stability during glass production. However, if the content is too high, a problem of an increase in the characteristic temperature may occur. Specifically, it is preferable to set the Fe2O3 content to 2.5 mol% or more and 8 mol% or less. It is preferable to set the BaO content to 3 mol% or more and 10 mol% or less, and to set the WO3 content to 1 mol% or more and 6 mol% or less.

[0020] In order to produce a uniform glass, the proportions of the components (mol%) among the main components of the lead-free low melting point glass composition with respect to the following oxides are set as follows: [V2O5] < 2[R2O] + 6[Fe2O 3] + 2 [BaO] < 3. 5 [V2O5] , [WO 3] < [BaO] < [R2O] + [Fe2O 3] < [V2O 5] < [TeO2] + [R2O] and [R2O] < 6[Fe2O 3] (R: alkali metal element). The TeO2 content is adjusted to 25 mol% or more and 43 mol% or less, and the R2O content is adjusted to 4 mol% or more and 27 mol% or less.

[0021] The additional component serves to suppress the tendency to crystallize and contributes to an improvement in chemical stability. The inventors have found that the presence of phosphorus oxide poses a hindrance to the addition of these additional components as glass components to the glass structure. Generally, it is known that phosphorus oxide is a glass component likely to be vitrified with vanadium oxide. However, the lead-free low-melting-point glass composition of the present invention is characterized by not containing phosphorus oxide to allow the content of the above-described additional components.

[0022] With regard to the production of homogeneous glass, the following ratios are observed among the additional components: 2[R2O] + 6[Fe2O 3] + 2 [BaO] + 6 [Y2O 3] + 6 [La2O3] + 4 [CeO 2]+ 6 [Er2O3] + 6 [Yb2O3] + 6 [Al2O3] + 6 [Ga2O3] < 3.5 [V2O5], based on the oxides of Y2O3, La2O3, CeO2, Er2O3, Yb2O3, Al2O3, and Ga2O3. It is preferable to set the proportion of the additional component to 0.5 mol% or more and 4.5 mol% or less, expressed as the oxides of the components described above. Setting the proportion to 0.5 mol% or more ensures that sufficient effects are achieved, resulting in suppression of the tendency to crystallization and improvement of chemical stability. Setting the proportion to 4.5 mol% or less ensures that an increase in the characteristic temperature is suppressed. Among the additional components described above, the use of Y2O3, La2O3, and Al2O3 proves to be particularly effective. It is preferable to set the proportion to 1 mol% or more and to 3 mol% or less.

[0023] With the known lead-free low-melting-point glass composition based on V2O5-TeO2, it is difficult to achieve highly reliable sealing and adhesion at 370°C or lower. In contrast, the glass with the above-described composition was found to successfully lower characteristic temperatures such as the transition temperature, yield strength, and softening temperature, thereby improving chemical stability. Furthermore, an improvement in adhesion and close contact with various substrates (members to be sealed and bonded) was also observed. It was found that adjusting the above-described composition range made it possible to lower the second endothermic peak temperature (hereinafter referred to as the softening temperature) in differential thermal analysis to 350°C or lower.Therefore, it is possible to provide a lead-free low melting point glass composition having excellent softening fluidity at 370°C or below, in other words, enabling sealing and strong bonding to various substrates at a low temperature of 370°C or below.

[0024] The density of the glass is 4.1 g / cm 3 or less. In general, a glass with a higher density has a greater probability of decreasing its characteristic temperature. In contrast, the characteristic temperatures T g , M g and T s of the lead-free glass with a low melting point is determined by the glass viscosity. These temperatures T g , M g and T s correspond to the values ​​10 13·3 Poise, 10 11,0 Poise or 10 7,65 Poise. The tendency to crystallize is determined according to the temperature Tcry and the magnitude of the exothermic peak due to crystallization. Glass with an increased value of T cry , ie an increased temperature difference between T s and T cry , and a reduced value of the heat of crystallization can be considered as a glass in which crystallization is unlikely.

[0025] The heating temperature at which various components are sealed and bonded using the commonly used low-melting-point glass composition is influenced by the heating conditions, such as the ceramic particles contained in the composition, the type, proportion, and particle size of beads, the rate of temperature rise, the atmosphere, pressure, and the like. In most cases, the heating temperature is set at a temperature 30°C to 50°C higher than the softening point T sAt the heating temperature described above, the low-melting-point glass composition exhibits excellent softening fluidity without crystallizing. However, the characteristic temperatures of the lead-free low-melting-point glass composition according to an embodiment of the present invention, ie, the transition temperature T g that a lower density has a greater probability of lowering the characteristic temperature. The glass density is preferably 3.8 g / cm 3 or less, and the softening temperature of the glass composition is 330°C or below.

[0026] The characteristic temperature is explained below. In this specification, the characteristic temperature is measured by differential thermal analysis (DTA). The characteristic temperature is measured using glass particles with a particle size of several tens of µm, using high-purity alumina particles (α-Al2O3) as a reference sample, at a temperature rise rate of 5°C / minute in the atmosphere. Fig. Figure 1 shows an example of a representative DTA curve for the glass. As in Fig. 1, the starting temperature of the first endothermic peak corresponds to a transition temperature T g , the endothermic peak temperature corresponds to the yield strength M g , the second endothermic peak temperature corresponds to the softening temperature T s , and the starting temperature of the exothermic peak due to crystallization corresponds to the crystallization starting temperature T cry. In general, the individual characteristic temperatures are obtained by the tangential method. The yield strength M g and the softening temperature T s have low values ​​with a small temperature difference, ie there is a high viscosity gradient, resulting in excellent softening fluidity at a temperature that is 20°C to 40°C above the softening point T s In other words, since the softening temperature T sof the lead-free low-melting-point glass composition according to an embodiment of the present invention is 350°C or less, a heating process to 370°C or less can be performed. This makes it possible to reduce thermal damage to the sealing structural body (high functionality), improve productivity (cycle shortening), and improve the reliability of the sealing part and the bonded part while reducing environmental impact. Glass composite material and glass paste

[0027] The glass composite material includes the low melting point glass composition, ceramic particles and glass beads.

[0028] The following describes glass composite materials containing ceramic particles and glass beads. Glass beads are defined as glass particles with an average particle size of 50 µm or more.

[0029] Preferably, the glass composite material containing ceramic particles and beads contains the lead-free low-melting-point glass composition of the present invention (40 mol% or more and less than 100 vol%) and ceramic material (more than 0 vol% and 60 vol% or less). By setting the proportion of the lead-free low-melting-point glass composition to 40 vol% or more or the proportion of ceramic materials to 60 vol% or less, the lead-free low-melting-point glass composition is enabled to exhibit excellent softening fluidity and ensure highly reliable sealing and bonding.For the ceramic material, it is preferable to use at least one of the following components from the viewpoint of suppressing crystallization: zirconium phosphate tungstate (Zr2 (WO4) (PO4) 2), quartz glass (SiO2), borosilicate glass (SiO2-B2O3-based), soda-lime glass (SiO2-Na2O-CaO-based), β-eucryptite (Li2O·Al2O3·2SiO2), cordierite (2MgO·2Al2O3·5SiO2), zirconium silicate (ZrSiO4), alumina (Al2O3), mullite (3Al2O3·2SiO2) and niobium oxide (Nb2O3). Zirconium phosphate tungstate (Zr2(WO4) (PO4)2) or quartz glass (SiO2) may be the ceramic material that causes low-temperature expansion of the glass composite material, and its content is preferably 30 vol% or more and 60 vol% or less.

[0030] It is possible to use glass beads, for example made of soda-lime glass (glass based on SiO2-Na2O-CaO), borosilicate glass (glass based on SiO2-B2O3-Na2O) and quartz glass (SiO2).

[0031] The glass paste comprises the glass composite material containing the lead-free, low-melting-point glass composition, a binder, and a solvent. It is preferable to use polypropylene carbonate as the binder and dihydroterpineol as the solvent. The above-described combination of binder and solvent allows for virtually no crystallization of the lead-free, low-melting-point glass composition according to one embodiment of the present invention. This further enables the reduction of residual bubbles during the heating and firing process. It is possible to add a viscosity modifier and a lubricant as needed to ensure adjustment of the stability and application properties of the glass paste. Sealing structure body

[0032] The glass composite material and the glass paste are suitable for sealing and bonding the heat-insulating multilayer vacuum glass used for window glass or the like, a display panel such as a plasma display panel, an organic EL display panel, a fluorescent display tube, and a packaging device such as a crystal resonator, an IC package, and MEMS. The sealing structural body of one embodiment of the present invention is made of the glass composite material described above. It includes an internal space and a sealing part that insulates at least a part of the boundary between the internal space and the external space. Preferably, the proportion of the lead-free low-melting-point glass composition in the glass composite material for forming the sealing part is 40 vol% or more.

[0033] The present invention will be described in detail below with reference to specific embodiments. The present invention is not limited to these embodiments. First embodiment

[0034] In a first embodiment, the glass composition described in Tables 1 and 2 below is prepared to evaluate the influence of the glass composition on the properties of the glass. Production of lead-free glass composition of low melting point

[0035] The lead-free low-melting point glass compositions A-01 to A-38 (inventive embodiments) and the lead-free low-melting point glass compositions B-01 to B-18 and B-20 to B-28 (comparative examples) listed in Table 1 are prepared as described below. The individual glass compositions listed in Tables 1 and 2 represent formulations for glass production. The starting materials used for glass production are powdered V2O5 and TeO2 with a purity of > 99% (product of Shinko Chemical Co., Ltd.) and the powdered products Li2CO3, Na2CO3, K2CO3, Fe2O3, BaCO3, WO3, Y2O3, La2O3, CeO2, Er2O3, Yb2O3, Al2O3, Ga2O3, P2O5 and ZnO (products of KOJUNDO CHEMICAL LABORATORY CO., LTD.).

[0036] The respective powdered raw materials are weighed, combined, and mixed so that the mixture has a total weight of approximately 200 g. This mixture is then placed in a platinum crucible. The platinum crucible containing the powdered mixture is placed inside a glass melting furnace and heated to 750°C to 950°C at a temperature elevation rate of approximately 10°C / minute. The mixture is left in a molten state in the crucible for 1 hour while stirring with an alumina rod to obtain a uniform composition. The lead-free low-melting-point glass compositions A-01 to A-07 according to the present embodiment are melted at 850°C, the compositions A-08 to A-28 at 800°C, and the compositions A-29 to A-38 at 750°C.As comparative examples, lead-free low-melting-point glass compositions B-01 to B-06 were melted at 950°C, compositions B-07 to B-18 and B-20 to B-27 were melted at 900°C, and composition B-28 was melted at 750°C. The platinum crucible was then removed from the glass furnace, and the molten liquid was poured into a stainless steel mold preheated to about 150°C, thereby obtaining lead-free low-melting-point glass compositions A-01 to A-38 and the lead-free low-melting-point glass compositions B-01 to B-18 and B-20 to B-27 serving as comparative examples. Measuring density

[0037] The lead-free, low-melting-point glass composition produced in this way is coarsely ground using a stamp mill and then ground using a Rakai mixer until a powder size of less than 45 µm is achieved. The density of the resulting powdered glass is measured pycnometrically in helium gas. Measurement of characteristic temperatures

[0038] The powdered glasses used for density measurement are subjected to differential thermal analysis (DTA) at a temperature increase rate of 5°C / minute in the atmosphere. Fig. The DTA curve shown in Figure 1 is obtained. The DTA of the macrocell type is used. The corresponding data for the transition temperature T g , the yield strength M g and the softening temperature T s are determined from the obtained DTA curve. Measurement of the thermal expansion coefficient

[0039] The produced lead-free glass compositions of low melting point are used in the temperature range from the transition temperature T g up to the yield point M g The DTA is heated and then gradually cooled to eliminate the remaining thermal stress. The composite is processed into a prism measuring 4 x 4 x 20 mm. The thermal expansion of the resulting glasses is measured with a thermal expansion meter at a temperature increase rate of 5°C / minute in the atmosphere. A columnar quartz glass measuring φ5 x 20 mm is used as a reference sample. Fig. Figure 2 shows a thermal expansion curve of a representative lead-free glass composition with a low melting point. Fig.2, the expansion value of the quartz glass used as a reference sample is subtracted. The lead-free glass composition with a low melting point expands upon heating. A significant expansion begins at the transition temperature T G , which is essentially the same as the transition temperature T derived from the DTA g collapses. Upon further heating until a deformation temperature A is reached T The lead-free glass composition of low melting point is thermally deformed, so that it appears to contract. In general, the thermal expansion coefficient of the glass is determined from the gradient in the temperature range from room temperature to a temperature below the T G-value. The respective thermal expansion coefficients of the lead-free low-melting-point glass compositions A-01 to A-38 according to the present embodiment are calculated from the gradient in the temperature range of 30°C to 200°C. The respective thermal expansion coefficients of the lead-free low-melting-point glass compositions according to the comparative examples are calculated from the gradient in the corresponding temperature ranges. That is, the values ​​of B-01 to B-06 are calculated from the gradient in the temperature range of 30°C to 300°C, the values ​​of B-07 to B-09 are calculated from the gradient in the temperature range of 30 to 250°C, and the values ​​of B-10 to B-18 and B-20 to B-28 are calculated from the gradient in the temperature range of 30 to 200°C. Production and evaluation of a sealing structure

[0040] The one in the Fig. 3A and Fig.The sealing structure shown in Figure 3B is manufactured using the lead-free, low-melting-point glass compositions and the low-thermal-expansion ceramic particles listed in Tables 1 and 2, and subjected to the HAST test for 48 hours at a temperature of 120°C, a humidity of 85%, and a pressure of 2 atm. Using a glass composite material 5 containing a lead-free, low-melting-point glass composition 3 and low-thermal-expansion ceramic particles 4, the Fig. 3A and Fig. 3B, by heating the perimeters of the glass substrates 1, 2, each having dimensions of 50 mm x 50 mm and a thickness of 3 mm, at a temperature 20°C to 30°C higher than the temperature T sthe lead-free glass composition 3 with a low melting point. A spacer 6 is placed between the two glass substrates 1 and 2 to form an interior space 7. Soda-lime glass (glass based on SiO2-Na2O-CaO) with a thermal expansion coefficient of 88 x 10 -7 / °C is used to form the glass substrates 1, 2.

[0041] The Fig. 4 and Fig. 5 show the process for producing the Fig. 3A and Fig.3B. A glass composite paste 8 containing particles of the lead-free low-melting-point glass composition 3 specified in Tables 1 or 2, low-thermal-expansion ceramic particles 4, a binder, and a solvent is prepared. Powdered glass with a size of less than 45 µm for measuring the density and characteristic temperature is used for the particles of the lead-free low-melting-point glass composition 3. Zirconium phosphate tungstate (Zr2(WO4)(PO4)2) with an average particle size of approximately 15 µm is used as the low-thermal-expansion ceramic particles 4. The density and thermal expansion coefficient of the ceramic material are 3.8 g / cm 3 or -32 x 10 -7 / °C. The ratio of the proportion of lead-free glass composition 3 with low melting point to the proportion of ceramic particles with low thermal expansion is adjusted so that the thermal expansion coefficient is approximately 80 x 10 -7 / °C. This adjustment is made to suppress the effect of tensile strength on the glass composite material 5 of the sealing part as much as possible, in view of the thermal expansion coefficient of the glass substrates 1, 2 to be used, i.e., soda-lime glass. In order to minimize the residual bubbles in the glass composite material 5 of the sealing part, polypropylene carbonate is used as a binder and dihydroterpineol is used as a solvent. After testing various binders and solvents, it was found that the above-described combination is most effective in minimizing the residual bubbles in the lead-free low-melting-point glass composition of the present invention and in the glass composite material containing the lead-free low-melting-point glass composition.The glass composite paste 8 is prepared, wherein the solid content comprising the particles of the lead-free glass composition 3 of low melting point and the ceramic particles of low thermal expansion is adjusted to the range of 80 to 85 mass%.

[0042] As in Fig. 4, the prepared glass composite paste 8 is applied to an outer periphery of the glass substrate 1 with a dispenser and dried at 150°C. Subsequently, heating is carried out in the temperature range from the transition temperature T g up to the yield point M g of the glass composition 3 to be used with a low melting point at a temperature increase rate of 5°C / minute in the atmosphere. The temperature is maintained for 30 minutes and then heated at a similar temperature increase rate to a temperature 20°C to 30°C above the softening temperature Ts The temperature is maintained for 30 minutes to perform a firing process to form the glass composite material 5 along the outer circumference of the glass substrate 1. As shown in Fig. 5, four columnar spacers 6, each having dimensions of φ500 µm × 200 µm, are arranged on the other glass substrate 2 so that they face the glass substrate 1 with the applied glass composite material 5. Four heat-resistant clamps 9 are attached to the four sides of the respective glass substrates 1, 2, after which heating of the low-melting point glass composition 3 to be used to a temperature 20°C to 30°C higher than the softening temperature T sat a temperature increase rate of 5°C / minute in the atmosphere. This temperature is maintained for 30 minutes. A seal is applied to produce the sealing structure body as shown in the Fig. 3A and Fig. 3B. The interior space 7 of the manufactured sealing structure body is slightly in a pressure-free state, which results from the compressed air.

[0043] The manufactured sealing structure is subjected to a 48-hour HAST test (temperature 120°C, humidity 85%, pressure 2 atm) to evaluate the reliability of the sealing part. If exfoliation leading to leakage is observed in any part of the sealing part, the sealing structure is rated as unacceptable "x." If no exfoliation is observed with essentially no leakage, the sealing structure is rated as acceptable "o." If leakage occurs, water will penetrate the interior of the sealing structure. Therefore, the evaluation is easy to perform. The evaluation is conducted in detail with regard to reducing the sealing temperature. The detailed evaluation is performed as follows.If the assessment shows that a highly reliable seal is achieved at a low temperature of 370°C or below, the product is accepted and receives a rating of good "◯". In particular, if the assessment shows that a highly reliable seal is achieved at a low temperature of 350°C or below, the product is accepted and receives a rating of excellent "⊚". Conversely, if the sealing temperature exceeds 370°C or the sealing is not highly reliable, the product receives an unacceptable rating of "x". A reinforced glass substrate intended for use as a sealed member or bonded member must be sealed and bonded at a temperature at least lower than 370°C. In the above case, the softening point T sthe lead-free, low-melting-point glass composition to be used must be adjusted so that the temperature is not more than 350°C or less.

[0044] Since the temperature range for actual mass production must be sufficiently considered, a product that can be sealed or bonded at 350°C or below is advantageous. Consequently, it is preferable to use a softening point T s the lead-free glass composition to be used must have a low melting point and be adjusted to a temperature at least below 330°C.

[0045] Tables 1 and 2 show data on the glass compositions, namely the density, characteristic temperature, and thermal expansion coefficient of the lead-free low-melting-point glass compositions A-01 to A-38 according to the present embodiment and the lead-free low-melting-point glass compositions B-01 to B-18 and B-20 to B-28 as comparative examples. Table 3 shows data on the sealing conditions and evaluation results of the sealing structural bodies obtained using the glass composite materials containing the lead-free low-melting-point glass compositions according to the present embodiment shown in Table 1 and ceramic particles.Table 4 shows data regarding the sealing conditions and evaluation results of the sealing structural bodies prepared using the glass composite materials containing the low-melting glass compositions according to the comparative examples shown in Table 2 and ceramic particles. Table 2 Compositions and properties of lead-free glass (comparative examples) Comparison example no. Glass composition (mol%) Density (g / cm 3 ) characteristic temperature (°C) thermal expansion coefficient P2O5 V2O5 TeO2 K2O Fe2O3 BaO WO3 La2O3 ZnO Transition temperature T g Yield strength M g Softening temperature T s (×10 -7 / °C) Temperature range B-01 20,1 41,7 - - - 30,9 7,3 - - 3,85 362 384 433 109 30-300 B-02 23,1 46,7 - - - 22,9 7,3 - - 3,63 350 378 427 98 B-03 23,2 37,5 5,3 - - 23,0 11,0 - - 3,85 376 403 457 102 B-04 20,1 41,8 5,3 - - 25,5 7,3 - - 3,81 352 370 426 111 B-05 22, 3 36,1 - 8, 8 - 22,2 10,6 - - 3,69 357 381 430 129 B-06 20,5 36,0 - 5,2 - 31,2 7,1 - - 3,82 356 384 430 131 B-07 - 33,1 24,2 - - 15,1 6,7 - 20,9 4,38 300 314 366 126 30-250 B-08 15,2 43,0 31,3 - 10,5 - - - - 3,58 298 320 360 98 B-09 11,7 41,3 31,3 - 15,7 - - - - 3,65 312 340 381 93 B-10 11,8 43,5 31,6 - 7, 4 - 3,6 - 2,1 3,69 281 308 355 95 30-200 B-11 10,6 42,1 29,2 - 6,3 - 5,7 - 6,1 3,76 282 309 359 95 B-12 6,0 42,5 41,9 - 7,4 - 2,2 - - 3,89 276 300 339 109 B-13 5, 9 41, 8 39,2 - 7, 4 - 3,6 - 2,1 3,89 280 303 342 107 B-14 5, 9 39,8 41,2 - 7, 4 - 3,6 - 2,1 3, 94 282 307 346 109 B-15 5, 9 38,8 42,2 - 7, 4 - 3,6 - 2,1 3,97 281 307 347 108 B-16 6,7 34, 4 31,0 8, 8 - 12,0 7,1 - - 4, 05 276 293 336 157 B-17 5,8 37,7 32,2 - - 17,0 7,3 - - 4,23 292 312 354 125 B-18 3,6 37,8 34,4 - - 16,8 7, 4 - - 4,30 289 309 345 130 B-20 - 37,8 32,3 - - 22,5 7,4 - - 4,39 284 303 334 143 B-21 - 37,9 37,8 - - 16,9 7, 4 - - 4,43 276 298 331 137 B-22 - 37,6 34,2 3,6 - 16,7 7, 4 0, 5 - 4,11 271 295 328 140 B-23 - 38,1 36,9 - - 17,0 7,5 0, 5 - 4,42 279 302 335 135 B-24 - 37,4 36,2 - - 14,4 7,3 0,5 4,2 4,40 277 299 333 132 B-25 - 37,6 36,4 1, 8 - 17,8 5, 9 0,5 - 4,36 275 300 332 142 B-26 - 34,9 40,9 - - 16,8 7, 4 - - 4,49 279 303 338 142 B-27 - 37,8 36,6 - - 19,2 5, 9 0,5 - 4,40 277 304 336 136 B-28 - 30,0 25,0 30,0 3,0 6,6 5,0 1,0 - 3,32 251 271 317 205 Table 3 Evaluation results of the sealing structure body (embodiments according to the invention) Embodiment No. Glass composite material (vol%) Sealing temperature (°C) HAST (48 hours) Temperature: 120°C - Humidity: 85% - Pressure: 2 atm Overall rating Glass content Ceramic content A-01 72 28 370 ◯ ◯ A-02 69 31 370 ◯ ◯ A-03 72 28 370 ◯ ◯ A-04 65 35 360 ◯ ◯ A-05 67 33 370 ◯ ◯ A-06 68 32 370 ◯ ◯ A-07 64 36 350 ◯ ⊚ A-08 63 37 360 ◯ ◯ A-09 65 35 370 ◯ ◯ A-10 70 30 360 ◯ ◯ A-11 69 31 360 ◯ ◯ A-12 66 34 350 ◯ ⊚ A-13 64 36 360 ◯ ◯ A-14 60 40 350 ◯ ⊚ A-15 56 44 350 ◯ ⊚ A-16 58 42 360 ◯ ◯ A-17 56 44 330 ◯ ⊚ A-18 58 45 350 ◯ ⊚ A-19 64 36 370 ◯ ◯ A-20 55 45 370 ◯ ◯ A-21 57 43 370 ◯ ◯ A-22 54 46 350 ◯ ⊚ A-23 54 46 330 ◯ ⊚ A-24 54 46 350 ◯ ⊚ A-25 54 46 350 ◯ ⊚ A-26 58 42 330 ◯ ⊚ A-27 57 43 330 ◯ ⊚ A-28 54 46 340 ◯ ⊚ A-29 54 46 310 ◯ ⊚ A-30 51 49 310 ◯ ⊚ A-31 50 50 330 ◯ ⊚ A-32 55 45 310 ◯ ⊚ A-33 50 50 320 ◯ ⊚ A-34 48 52 330 ◯ ⊚ A-35 54 46 340 ◯ ⊚ A-36 49 51 340 ◯ ⊚ A-37 50 50 350 ◯ ⊚ A-38 53 47 350 ◯ ⊚ Table 4 Evaluation results of the sealing structure body (comparative examples) Comparison example no. Glass composite material (vol%) Sealing temperature (°C) HAST (48 hours) Temperature: 120°C - Humidity: 85% - Pressure: 2 atm Overall rating Glass content Ceramic content B-01 79 21 460 × × B-02 86 14 450 × × B-03 84 16 480 × × B-04 78 22 450 × × B-05 70 30 460 ◯ × B-06 69 31 460 ◯ × B-07 71 29 390 × × B-08 86 14 390 ◯ × B-09 90 10 410 ◯ × B-10 88 12 380 ◯ × B-11 88 12 380 ◯ × B-12 79 21 360 × × B-13 81 19 370 × × B-14 79 21 370 × × B-15 80 20 370 × × B-16 59 41 360 × × B-17 71 29 360 × × B-18 69 31 370 × × B-20 64 36 360 × × B-21 66 34 360 × × B-22 65 35 350 × × B-23 67 33 360 × × B-24 68 32 360 × × B-25 64 36 360 × × B-26 64 36 360 × × B-27 67 33 360 × × B-28 47 53 340 × ×

[0046] Leakage due to exfoliation is observed in the HAST test for most of the sealing structural bodies made using the lead-free low-melting-point glass compositions B-01 to B-18 and B-20 to B-28, which serve as comparative examples. No leakage is observed in comparative examples B-05, B-06, B-08 to B-11, which result in a highly reliable sealing part. Due to the high softening temperatures T s The corresponding lead-free low-melting-point glass compositions B-05, B-06, and B-08 to B-11 require a high sealing temperature, resulting in difficulties in sealing at 370°C or below. In other words, with the lead-free low-melting-point glass compositions of Comparative Examples, it is difficult to improve the reliability of the sealing part when the sealing temperature is lowered.

[0047] On the other hand, in the HAST test, the sealing structural bodies produced using the lead-free low-melting point glass compositions A-01 to A-38 according to the present embodiment exhibit no leakage due to exfoliation, so it is possible to lower the sealing temperature to 370°C or less. It is found that the present embodiment achieves a reduction in the softening temperature T s The lead-free low-melting-point glass composition enables a highly reliable sealing part to be obtained even when the sealing temperature is 350°C or less. This means that the lead-free low-melting-point glass composition according to the present embodiment enables a reduction in the sealing temperature and an improvement in the reliability of the sealing part.

[0048] The lead-free low-melting-point glass compositions A-01 to A-38 according to the present embodiment listed in Table 1 are compared with compositions B-01 to B-18 and B-20 to B-28 to determine differences. The lead-free low-melting-point glass composition according to the present embodiment does not contain phosphorus oxide (P2O5), but contains vanadium oxide (V2O5), tellurium oxide (TeO2), alkali metal oxide (R2O), iron oxide (Fe2O3), barium oxide (BaO), and tungsten oxide (WO3), and at least one of the additional components yttrium oxide (Y2O3), lanthanum oxide (La2O3), cerium oxide (CeO2), erbium oxide (Er2O3), ytterbium oxide (Yb2O3), alumina (Al2O3), and gallium oxide (Ga2O3). The content of TeO2 is 25 mol% or more and 43 mol% or less. The proportion of R2O is 4 mol% or more and 27 mol% or less.

[0049] In the present embodiment, the use of Li2O, Na2O, and K2O as the alkali metal oxide R2O is investigated. Furthermore, the use of Rb2O and Cs2O is expected to result in similar effects to those described above. Preferably, Li2O, Na2O, and K2O are used in consideration of the glass material cost. The suitable proportion of the alkali metal oxide is in the range of 4 mol% to 27 mol%. It has been found that the use of K2O at a low R2O content within the specified range and the use of Li2O at a high R2O content within the specified range tend to result in a more advantageous contribution to lowering the characteristic temperature and reducing the deterioration of chemical stability.

[0050] The density of the lead-free low melting point glass composition according to the present embodiment is 4.1 g / cm 3or less, and the second endothermic peak temperature (softening temperature) in differential thermal analysis is 350°C or less. The density and softening temperature of a particularly preferred lead-free glass composition with a low melting point are 3.8 g / cm 3 or less or 330°C or less.

[0051] Hereinafter, the glass composite material containing the lead-free low melting point glass composition of the present invention, the glass paste and the sealing structural body, and electrical / electronic parts to which the glass composite material and the glass paste are applied will be described in detail. Second embodiment

[0052] In a second embodiment, the glass composite material containing the lead-free low-melting-point glass composition and ceramic particles or beads is used to seal the respective outer peripheral lines of the same types of metal substrates, ceramic substrates, and glass substrates to produce a sealing structural body as in the first embodiment. The thus-prepared sealing structural body is subjected to the HAST test for 48 hours to evaluate the reliability of the sealing part. Four types of lead-free low-melting-point glass compositions A-05, A-14, A-24, and A-32 listed in Table 1 are used. Further, ten types of ceramic particles or beads C-01 to C-10 listed in Table 5 are used.Table 5 also provides data on the density, thermal expansion coefficient, and average particle size of the ceramic particles or beads used in this embodiment.

[0057] Table 5 Density, thermal expansion coefficient and average particle size of the ceramic particles or ceramic beads Nr. Ceramics Density (g / cm 3 ) Thermal expansion coefficient (×10 -7 / °C) Average particle size (µm) C-01 Zirconium phosphate tungstate Zr2 (WO4) (PO4) 2 3,8 -32 15 C-02 Quartz glass SiO2 2,2 5 75 C-03 Borosilicate glass, glass based on SiO2-B2O3-Na2O 2,3 58 66 C-04 Soda-lime glass, glass based on SiO2-Na2O-CaO 2,5 88 105 C-05 β-Eucryptite Li2O ·Al2O3 ·2SiO2 2,4 -60 7 C-06 Cordierite 2MgO ·2Al2O3 ·5SiO2 2,5 1 6 C-07 Zirconium silicate ZrSiO4 4,6 45 9 C-08 Aluminum oxide Al2O3 4,0 81 53 C-09 Mullite 3Al2O3 ·2SiO2 3,2 33 7 C-10 Niobium oxide Nb2O5 4,6 12 5

[0053] An aluminum substrate (Al) measuring 50 mm × 50 mm and 3 mm thick is used as the metal substrate. An aluminum oxide substrate (Al2O3) measuring 50 mm × 50 mm and 1.5 mm thick is used as the ceramic substrate. A borosilicate glass (glass based on SiO2-B2O3-Na2O) measuring 50 mm × 50 mm and 2 mm thick is used as the glass substrate. The thermal expansion coefficients of the aluminum substrate, the aluminum oxide substrate, and the borosilicate glass substrate are 224 × 10 -7 / °C, 81 × 10 -7 / °C or 58 × 10 -7 / °C. In the production of the sealing structure to be evaluated, the glass paste containing particles of the lead-free, low-melting-point glass composition, ceramic particles or beads, a binder, and a solvent is first prepared. The prepared glass paste is then applied to the corresponding outer perimeters of the substrates as in the first embodiment. After drying and firing, spacers are applied. Heating is performed together with the counter substrate for sealing. Production of the glass paste

[0054] The glass paste is prepared as in the first embodiment, except that the mixing ratio between the particles of the lead-free low-melting-point glass composition and the ceramic particles or beads is modified. In this case, eight types of mixing ratios between the particles of the lead-free low-melting-point glass composition and the ceramic particles or beads are used: 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, and 30:70, expressed in vol%. The solid content (sum of the lead-free glass composition and the ceramic material) of the glass paste is set to approximately 80 mass%. Production and evaluation of the sealing structure body

[0055] The sealing structural body is manufactured similarly to the first embodiment and subjected to the HAST test for 48 hours to evaluate the reliability of the sealing part. The sealing temperature of the sealing structural body is determined according to the lead-free low-melting-point glass composition contained in the glass composite material. As in the first embodiment, the sealing temperature corresponding to the proportion of A-05 is set to 370°C, the sealing temperature corresponding to the proportions of A-14 and A-24 is set to 350°C, and the sealing temperature corresponding to the proportion of A-32 is set to 310°C. In manufacturing the sealing structural body, the lead-free low-melting-point glass composition and the type and proportion of the ceramic material contained in the glass paste are selected in consideration of the thermal expansion coefficient values ​​of the respective substrates.

[0056] Tables 6 to 8 list the evaluation results of the HAST test conducted for the sealing structures with the corresponding substrates. Table 6 shows the evaluation results for the sealing structures with aluminum (Al) substrates. Table 7 shows the evaluation results for the sealing structures with aluminum oxide (Al2O3) substrates. Table 8 shows the evaluation results for the sealing structures with borosilicate glass (SiO2-B2O3-Na2O-based glass).

[0062] Table 6 Evaluation results of HAST test (48 hours) for sealing structural bodies using aluminum (Al) substrates Proportion of lead-free glass composition (vol%) 100 90 80 Proportion of ceramic material (vol%) 0 10 20 A-24 C-03 ◯ ◯ ◯ C-04 ◯ ◯ ◯ C-07 ◯ ◯ ◯ C-08 ◯ ◯ ◯ C-09 ◯ ◯ ◯ C-10 ◯ ◯ ◯ A-32 C-03 ◯ ◯ ◯ C-04 ◯ ◯ ◯ C-07 ◯ ◯ ◯ C-08 ◯ ◯ ◯ C-09 ◯ ◯ ◯ C-10 ◯ ◯ ◯

[0063] Table 7 Evaluation results of the HAST test (48 hours) for sealing structural bodies using aluminum oxide (Al2O3) substrates Proportion of lead-free glass composition (vol%) 70 60 50 Proportion of ceramic material (vol%) 30 40 50 A-14 C-01 ◯ ◯ ◯ C-02 ◯ ◯ ◯ C-06 ◯ ◯ ◯ A-32 C-01 ◯ ◯ ◯ C-02 ◯ ◯ ◯ C-06 ◯ ◯ ◯ A-32 C-01 ◯ ◯ ◯ C-02 ◯ ◯ ◯ C-06 ◯ ◯ ◯ Table 8 Evaluation results of the HAST test (48 hours) for sealing structural bodies using borosilicate glass (glass based on SiO2-B2O3-Na2O) substrates Proportion of lead-free glass composition (vol%) 60 50 40 Proportion of ceramic material (vol%) 40 50 60 A-05 C-01 ◯ ◯ ◯ C-02 ◯ ◯ ◯ C-05 ◯ ◯ ◯ A-14 C-01 ◯ ◯ ◯ C-02 ◯ ◯ ◯ C-05 ◯ ◯ ◯ A-32 C-01 ◯ ◯ ◯ C-05 ◯ ◯ ◯

[0057] In the case of the sealing structural body containing the aluminum (Al) substrates, the ceramic materials C-03, C-04, and C-07 to C-10 are used according to Table 6, with the proportion adjusted to 0-20 vol%. The use of lead-free glass compositions A-24 and A-32 is evaluated in the range of 100 to 80 vol%. Under all conditions, no leakage due to exfoliation is observed after 48 hours of the HAST test, thus obtaining a highly reliable sealing part. The use of A-24 or A-32 results in high bond strength and very close contact with the aluminum (Al) substrate.

[0058] In the case of the sealing structural body with the alumina (Al2O3) substrates, the ceramic materials C-01, C-02, and C-06 are used according to Table 7, with the proportion adjusted to 30 to 50 vol%. The use of the lead-free glass compositions A-14, A-24, and A-32 is evaluated in the range of 70 to 50 vol%. Under all conditions, no leakage due to exfoliation is observed after a 48-hour HAST test, thus obtaining a highly reliable sealing part. The use of the lead-free low-melting-point glass compositions A-14, A-24, or A-32 results in high bond strength and very close contact with the alumina (Al2O3) substrate.

[0059] In the case of the sealing structure comprising the borosilicate glass (SiO2-Ba2O3-Na2O) substrates, the ceramic materials C-01, C-02, and C-05 are used according to Table 8, with the proportion set at 40 to 60 vol%. The use of the lead-free glass compositions A-05, A-14, or A-32 is evaluated in the range of 60 to 40 vol%. Under all conditions, no leakage due to exfoliation is observed after the 48-hour HAST test, indicating that a highly reliable sealing part has been obtained. The use of the lead-free, low-melting-point glass compositions A-05, A-14, or A-32 results in high bond strength and very close contact with the borosilicate glass (SiO2-B2O3-Na2O) substrate.

[0060] It has been found that the use of the glass composite material containing the lead-free low-melting point glass composition of the present invention in a proportion of 40 to 100 vol% or less, and ceramic particles and beads in a proportion of 0 to 60 vol%, enables low-temperature hermetic sealing and low-temperature adhesion to the respective substrates. In this embodiment, the use of lead-free low-melting point glass compositions A-05, A-14, and A-32 was described as a representative example. However, it is readily apparent that the use of any other lead-free low-melting point glass compositions of the present invention will produce equivalent results to the above-described case.In a non-limiting manner, the use of zirconium phosphate tungstate (Zr2(WO4) (PO4) 2), fused silica (SiO2), borosilicate glass (SiO2-B2O3 based), soda-lime glass (SiO2-Na2O-CaO based), β-eucryptite (Li2O·Al2O3·2SiO2), cordierite (2MgO·2Al2O3·5SiO2), zirconium silicate (ZrSiO4), alumina (Al2O3), mullite (3Al2O3·2SiO2) and niobium oxide (Nb2O5) for the ceramic particles or beads contained in the glass composite material and the glass paste was explained. Third embodiment

[0061] In a third embodiment, two air-quenched soda-lime glass substrates and the glass composite material are used to produce a heat-insulating multi-layer vacuum glass pane as a representative example of the sealing structural body shown in the Fig. 6A and Fig. 6B is used.

[0062] Fig.Figure 6A is a schematic plan view of the manufactured heat-insulating multi-layer vacuum glass panel. Fig. 6B is an enlarged cross-sectional view of an area around the sealing part taken along line AA of Fig. 6A. As in Fig. 6A, the heat-insulating multi-layer vacuum glass sheet comprises a sealing member 12 which is bonded to the peripheral edges of the air-quenched soda-lime glass substrate 10 and to an air-quenched soda-lime glass substrate (reference numeral 11 of Fig.6B). The substrates are laminated while maintaining a gap. A plurality of spacers 13 are arranged two-dimensionally at equal intervals between the substrates 10, 11. The air-quenched soda-lime glass substrate 11 includes an exhaust hole 14 for performing an exhaust operation by means of a vacuum pump (not shown) from the space between the two substrates 10, 11. A cap 15 is attached to the exhaust hole 14.

[0063] As in Fig.As shown in Figure 6B, a space 16 (the above-described gap) is formed between the pair of air-quenched soda-lime glass substrates 10 and 11, with the sealing member 12 applied to the outer peripheral lines (circumferential edges). The space 16 is in an evacuated state. The glass composite material of the present invention is used to form the sealing member 12. The heat-insulating, vacuum-formed multilayer glass panel can be applied to window glass for buildings, vehicles, and doors for commercial refrigerators and freezers.The glass composite material of the present invention used for the sealing member 12 contains the ceramic particles or beads with a low thermal expansion coefficient to ensure matching of the thermal expansion coefficients of the air-quenched soda-lime glass substrates 10 and 11, in addition to the lead-free low-melting-point glass composition of the present invention. A compression-reinforced layer is formed on each surface of the air-quenched glass substrates 10, 11. Upon heating to a temperature above 320°C, the reinforced layer gradually reduces, and upon further heating to 400°C or higher, it disappears. Therefore, it is preferable to set the sealing temperature as low as possible. The sealing member 12 must be formed at a temperature at least below 370°C.The individual, air-quenched soda-lime glass substrates 10, 11 exhibit low thermal conductivity. Furthermore, increasing the size of the substrates makes it difficult to achieve uniform heating and cooling. Furthermore, rapid heating and cooling can cause damage to the substrates. Consequently, they must be heated and cooled gradually during the sealing process. Sealing at the lowest possible temperature ensures efficient production of the heat-insulating, multilayer vacuum glass sheet with high yield. If possible, sealing at a temperature of 350°C or lower is desirable.

[0064] The space 16 between the air-quenched glass substrates 10 and 11 is maintained in an evacuated state by the spacers 13. The vacuum pump is used to evacuate the space 16 through the exhaust hole 14 previously formed in the air-quenched soda-lime glass substrate 11. After evacuation, the cap 15 is fitted over the hole to maintain the space 16 in an evacuated state. When the sealing structure is applied to window glass for buildings or vehicles, a heat radiation-reflecting film 17 may be previously applied to the inner surface of the air-quenched soda-lime glass substrate 10 by a vapor deposition method or the like. Production of a glass paste

[0065] The glass paste is produced by combining and mixing particles of the lead-free low-melting-point glass composition, ceramic particles and beads, a binder, and a solvent in a predetermined ratio. Particles of the lead-free low-melting-point glass composition A-24 with a particle size of less than 45 µm are used. Particles and beads of ceramic material C-01 (zirconium phosphate tungstate particles) with an average particle size of approximately 15 µm and ceramic material C-02 (silica beads) with an average particle size of approximately 75 µm are used. Polypropylene carbonate and dihydroterpineol are used as the binder and solvent, respectively.The glass paste for sealing purposes is prepared by adjusting the mixing ratio of the lead-free low-melting point glass composition A-24, the ceramic particles C-01, and the ceramic beads C-02 to 50:30:20, expressed as vol%, so that the solid content (sum of A-24, C-01, and C-02) is adjusted to approximately 80 mass%. Furthermore, a glass paste containing solid particles of only A-24 is prepared for fixing the spacers 13. Production of a heat-insulating, multi-layer vacuum glass pane

[0066] Hereinafter, the method for manufacturing the heat-insulating multi-layer vacuum glass panel according to the present embodiment will be described with reference to Fig. 7A to 10.

[0067] Fig.Fig. 7A shows a state in which the sealing member 12 and the spacers 13 are formed on the air quenched soda-lime glass substrate 11 having the Fig. 6A and Fig. 6B illustrates the heat-insulating, multi-layer vacuum glass pane. As shown in Fig.As shown in Figure 7A, the glass paste prepared in the above-described manner is applied to the outer peripheral line (sealing part 12) of the air-quenched soda-lime glass substrate 11 with a dispenser. The spacers 13 are arranged on the inside using the glass paste to fix the spacers. The substrate is dried in the atmosphere at 150°C and then heated in the atmosphere to 350°C at a temperature elevation rate of 2 to 3°C / minute. The substrate is left at this temperature for 30 minutes, after which the sealing part 12 and the spacers 13 are temporarily fixed to the air-quenched soda-lime glass substrate 11.

[0068] Fig. Figure 7B is a cross-sectional view along line AA of Fig. 7A. As from Fig.As can be seen from Figure 7B, it is essential that the temporarily fixed sealing member 12 be higher than the temporarily fixed spacers 13 to achieve an airtight seal. In this embodiment, an air-quenched soda-lime glass substrate 10 measuring 900 x 600 x 3 mm and an air-quenched soda-lime glass substrate 11 having the exhaust hole 14 are used. The heat-ray reflecting film 17 is applied to the air-quenched soda-lime glass substrate 10. In order to adjust the gap between the air quenched soda-lime glass substrates 10 and 11, that is, the height of the space 16, to about 200 µm, the stainless steel columnar spacer 13 with a diameter of 500 µm and a height of 190 µm is fixed to the other substrate using the lead-free low melting point glass composition A-24 shown in Table 1.

[0069] Fig. Figure 8A shows the air-quenched soda-lime glass substrate 10, which is a component of the Fig. 6B is the heat-insulating, multi-layer vacuum glass pane shown. Fig. Figure 8B is a cross-sectional view along line AA of Fig. 8A. As in the Fig. 8A and Fig. As shown in Fig. 8B, a heat ray reflecting film 17 is applied to one side of the air quenched soda-lime glass substrate 10.

[0070] Fig. 9 is a cross-sectional view showing the heat-insulating multi-layer glass panel shown in FIGS. Fig. 6A and Fig. 6B in the manufacturing process (final process stage). According to Fig.9, the air-quenched soda-lime glass substrates 10, 11 are stacked one above the other, aligning their positions, and secured with a plurality of heat-resistant clamps. The resulting structure is subjected to heat treatment, with evacuation through the exhaust hole 14 for sealing.

[0071] Fig. Figure 10 shows a sealing temperature profile obtained during the heat treatment process. Fig. The sealing temperature profile shown in Figure 10 is obtained during the sealing process described below. In this process, the glass sheet is heated in the atmosphere to a temperature slightly higher than the yield strength Mg of the lead-free glass composition to be used. The temperature increase rate is 2 to 3°C / minute in the atmosphere. In this case, heating to 290°C occurs, which is slightly above the yield strength M gof A-24. The resulting structure is left at this temperature for 30 minutes and then heated to a temperature approximately 20°C above the softening point T s of the lead-free glass composition to be used. A temperature increase rate of 2 to 3°C / minute is maintained. In this case, heating to 340°C occurs, which is 19°C above the softening point T s of A-24, with the interior of the disc being evacuated through the suction hole 14 using the vacuum pump. The resulting structure is left for 30 minutes and sealed.

[0072] As in Fig.As shown in Figure 9, during the heat treatment process, the sealing member 12 and the spacers 13 are pressed together and brought into close contact with the two air-quenched soda-lime glass substrates 10, 11. Subsequently, the cap 15 is placed over the exhaust hole 14, thereby obtaining the heat-insulating multilayer vacuum glass panel. In this embodiment, ten of the above-described heat-insulating multilayer vacuum glass panels are manufactured. Evaluation results of the manufactured heat-insulating, multi-layer vacuum glass pane

[0073] First, the ten manufactured heat-insulating, multilayer vacuum glass panels according to this embodiment were subjected to a visual inspection. No cracks or scratches were found, demonstrating that they had a perfect appearance. The air-quenched soda-lime glass substrates 10 and 11 were spaced substantially evenly apart (approximately 200 µm) by means of spacers 13 arranged inside the panel. In other words, a heat-insulating, multilayer vacuum glass panel with the specified gap 16 was produced. The helium leakage test confirmed that the interior of the panel remained in a vacuum state, with the outer periphery of the panel hermetically sealed. The evaluation of the heat-insulating property showed the achievement of a low total heat transfer coefficient (0.7 to 0.9 W / m²). 2 ·K) .

[0074] To confirm the reliability of the sealing part 12, three of the manufactured heat-insulating, multilayer vacuum glass panes were subjected to a 48-hour HAST test. In all three tested panes, it was found that the interior maintained its vacuum, with no water penetration. Three additional heat-insulating, multilayer vacuum glass panes were subjected to a temperature cycling test in the temperature range of -50°C to +100°C, repeated 1500 times. In all three tested panes, it was found that the interior remained in an evacuated state. Based on these facts, it can be determined that the heat-insulating, multilayer vacuum glass pane comprising the glass composite material of the present invention and the glass paste produced using this material is capable of providing a sealing part 12 with high heat-insulating performance and high reliability.It is clear that the use of the glass composite material of the present invention and the glass paste prepared using such a material enables a reduction in the sealing temperature, which significantly contributes to improved productivity of the heat-insulating multilayer vacuum glass sheets and to the application to air-quenched strengthened soda-lime glass substrates.

[0075] It is confirmed that the glass composite material containing the lead-free low melting point glass composition of the present invention and the glass paste prepared using such a material are effectively applicable to the sealing part of the heat-insulating multilayer vacuum glass sheet, resulting in providing a sealing structural body having excellent reliability and productivity. Fourth embodiment

[0076] According to this embodiment, a display having a large number of organic light-emitting diodes (OLEDs) sandwiched between two borosilicate glasses is manufactured as a representative example of the sealing structural body.

[0077] Fig. 11A is a schematic plan view of an example of the OLED display. Fig. 11B is a cross-sectional view along line AA of Fig. 11A. According to Fig. 11A, the OLED display comprises the sealing part 12 as a glass composite material according to the invention, which is applied to the outer peripheral line of a borosilicate glass substrate 18, and a borosilicate glass substrate (reference numeral 19 in Fig. 11B), which is arranged above it, with a gap therebetween. The OLEDs 20 are arranged between the borosilicate glass substrates 18 and 19. Production of the glass paste

[0078] The glass paste is prepared by combining and mixing particles of the lead-free low-melting-point glass composition of the present invention, ceramic particles, a binder, and a solvent in predetermined ratios. Particles of the lead-free low-melting-point glass composition A-05 with an average particle size of about 2 µm are used. Particles of the ceramic material C-01 (zirconium phosphate tungstate particles) with an average particle size of about 3 µm are also used. Polypropylene carbonate and dihydroterpineol are used as binders and solvents, respectively. The particles of the ceramic material C-01 are prepared to contain iron tungstate (FeWO4) in the zirconium phosphate tungstate particles to ensure heat generation by effectively absorbing a red semiconductor laser, as described below.The glass paste for low-temperature sealing is prepared by adjusting the mixing ratio between the particles of the lead-free low-melting point glass composition A-05 and the ceramic particles C-01 to 45:55, expressed in vol%, so that the proportion of solids (sum of A-05 and C-01) is about 80 mass%. Manufacturing of the organic light-emitting diode display (OLED)

[0079] The Fig. 12A to 14 show the method of manufacturing the OLED display according to this embodiment.

[0080] Fig. Figure 12A shows one of the substrates of the OLED display. Fig. 12B is a cross-sectional view along line AA of Fig. 12A. As in Fig.As shown in Figure 12A, the glass paste prepared in the above-described manner is applied to the outer peripheral line of the borosilicate glass substrate 18 by screen printing. The substrate is dried in the atmosphere at 150°C, heated in the atmosphere at a temperature elevation rate of 5°C / minute to 370°C, and maintained at this temperature for 30 minutes. The sealing part 12 is obtained on the outer peripheral line of the borosilicate glass substrate 18. The sealing part 12 is formed on the outer peripheral line on the borosilicate glass substrate 18 such that the line width is about 2 mm and the film thickness in the fired state is about 15 µm.

[0081] Fig. 13A shows the other substrate of the OLED display. Fig. 13B is a cross-sectional view along line AA of Fig.13A. As shown in these drawings, a large number of OLEDs 20 are formed on a borosilicate glass substrate 19 according to the number of pixels. The borosilicate glass substrate 19 with the OLEDs 20 formed thereon and the borosilicate glass substrate 18 with the sealing member 12 applied thereon are arranged one above the other, as shown in Fig.14. In the above-described state, a laser 21 is irradiated under vacuum in the direction from the borosilicate glass substrate 18 to the sealing member 12. A red semiconductor laser with a wavelength of 805 nm is used for the laser 21 to enable effective absorption of the laser wavelength and heat generation in the lead-free, low-melting-point glass composition in the glass composite material of the present invention and the low thermal expansion ceramic particles, and to facilitate the softening fluidity of the lead-free, low-melting-point glass composition. The laser 21 is moved along the peripheral circumference line at a speed of 10 mm / second to bond the respective peripheral circumference lines of the borosilicate glass substrates 18 and 19 to the sealing member 12 to form the OLED display.

[0082] In the present embodiment, five OLED displays are manufactured. The laser is used for sealing to prevent thermal damage to the OLEDs and to improve productivity. Evaluation results of the fabricated organic light-emitting diode (OLED) display

[0083] First, a luminescence test is conducted on the manufactured OLED display. The results confirm trouble-free normal luminescence, as well as excellent contact and adhesion to the sealing part. After performing the 48-hour HAST test, a luminescence test is conducted on the OLED display in a similar manner. An OLED display sealed only with resin is used as a comparison example. The line width and thickness of the resin sealing part are approximately 5 mm and 15 µm, respectively. The OLED display sealed with the resin is severely damaged. The above-described damage is attributed to the influence of moisture and oxygen penetrating the interior of the OLED display through the resin sealing part, damaging the OLED. In contrast, the display manufactured according to the present invention exhibits satisfactory results without damage, demonstrating the good durability of the airtightness.From the result of the evaluation of the close contact and adhesion of the sealing part after conducting the HAST test, the severe damage that occurred in the resin sealing part cannot be detected, which suggests that the condition is essentially the same as before the test.

[0084] It is confirmed that the glass composite material containing the lead-free low melting point glass composition of the present invention and the glass paste prepared using this material can be effectively applied to the sealing part of the OLED, thereby providing a sealing structural body with high functionality including reliability and excellent productivity. Fifth embodiment

[0085] According to this embodiment, a crystal resonator package is manufactured as a representative example of the sealing structural body. Production of the glass paste

[0086] The glass paste for forming the sealing part 12 is prepared by combining and mixing particles of the lead-free low-melting-point glass composition, the ceramic particles, the binder, and the solvent. Particles of the lead-free low-melting-point glass composition A-13 with an average particle size of approximately 3 µm are used. Particles of the ceramic material C-01 (zirconium phosphate tungstate particles) with an average particle size of approximately 15 µm, as shown in Table 5, are used. Polypropylene carbonate and dihydroterpineol are used as the binder and solvent, respectively. The glass paste for forming the sealing part 12 is prepared by adjusting the mixing ratio between the particles A-13 and the particles C-01 to 60:40 (expressed in vol%) so that the solid content (the sum of A-13 and C-01) is approximately 80% by mass. Manufacturing a crystal resonator housing

[0087] The Fig. 15A to 15F show a series of process steps for manufacturing a crystal resonator package. Fig. Figure 16 is a schematic cross-sectional view of the fabricated crystal resonator package.

[0088] The crystal resonator housing of Fig.16 includes a crystal resonator 25 disposed on a surface of a ceramic substrate 23 with wiring 22 via a conductive contacting member 24. The wiring 22 is electrically connected to the conductive contacting member 24, thereby electrically connecting the crystal resonator 25 to the outside. A ceramic cap 26 protecting the crystal resonator 25 is hermetically bonded to the outer periphery of the ceramic substrate 23 and the sealing member 12. In this embodiment, the glass paste described above is used to manufacture the sealing member 12, and alumina (α-Al2O3) is used to manufacture the ceramic substrate 23 and the ceramic cap 26.

[0089] The method for manufacturing the crystal resonator package is described below with reference to the Fig. 15A to 15F. First, the ceramic substrate 23 with the wiring 22 is manufactured ( Fig.15A). The conductive contacting part 24 is applied to the wiring 22 ( Fig. 15B). The crystal resonator 25 is placed on the conductive contacting part 24 and heated under vacuum so that the crystal resonator 25 is electrically connected to the conductive contacting part 24 ( Fig. 15C).

[0090] In the meantime, the ceramic cap 26 is manufactured ( Fig. 15D). The glass paste containing particles of the lead-free, low-melting-point glass composition and ceramic particles is applied to the outer periphery of the ceramic cap 26 and dried. The dried ceramic cap is heated in the atmosphere to bring the lead-free, low-melting-point glass composition contained in the glass composite material into a softened fluid state, thereby forming the sealing part 12 ( Fig.15E). In this embodiment, the glass paste is applied by screen printing and dried in the atmosphere at approximately 150°C. It is then heated in the atmosphere at a temperature increase rate of 10°C / minute to 360°C and left at this temperature for 30 minutes. This forms the sealing part 12 on the outer periphery of the ceramic cap 26.

[0091] The ceramic substrate 23 with the crystal resonator 25 and the conductive contacting part 24 ( Fig. 15C) and the ceramic cap 26 with the sealing part 12 ( Fig. 15E) are assembled and heated under inert gas or under vacuum, applying a low load 27 to bring the lead-free, low-melting-point glass composition contained in the sealing part 12 back into the softened fluidity state ( Fig. 15F), whereby the crystal resonator housing can be opened as shown in Fig.16. In the above-described process, care must be taken to ensure that the conductive contacting part 24 does not detach from the crystal resonator 25 and the wiring 22. As a result, it is effective to lower the softening point T s of the lead-free, low-melting-point glass composition contained in the sealing part 12 as low as possible.

[0092] In this embodiment, the ceramic cap 26 having the sealing member 12 is aligned with the ceramic substrate 23 connected to the crystal resonator 25, as shown in Fig.15F. The structure is clamped and loaded in a special jig. It is then heated to 360°C under vacuum at a temperature ramp rate of 10°C / minute and held at this temperature for 15 minutes. The ceramic cap 26 and the ceramic substrate 23 are sealed to form the crystal resonator housing. In this embodiment, 24 crystal resonator housings are manufactured. Evaluation results for the manufactured crystal resonator package

[0093] First, 18 of the crystal resonator packages manufactured according to this embodiment are subjected to a visual inspection. It is found that essentially no displacement of the ceramic cap 26 has occurred during sealing. Furthermore, the crystal resonator packages exhibit essentially no devitrification phenomena due to crystallization, nor any cracks or scratches on the sealing part 12, indicating a problem-free appearance.

[0094] A continuity test is performed for the wiring 22 on the back surface of the ceramic substrate 23 to determine whether the conductive contact part 24 inside the sealed ceramic cap 26 is electrically connected to the crystal resonator 25 and the wiring 22. The test results show that all the manufactured crystal resonator packages have the corresponding functional crystal resonators. Five of the manufactured crystal resonator packages are subjected to the helium test to confirm that the interior of the package is in an evacuated state, with the outer perimeter hermetically sealed with the sealing part 12. To confirm the reliability of the sealing part 12, five of the manufactured crystal resonator packages are subjected to the 48-hour HAST test. The helium leakage test is then performed.It is confirmed that all crystal resonator packages subjected to the HAST test maintain the airtightness and close contact of the sealing part 12.

[0095] It was found that by using the glass composite material containing the lead-free low melting point glass composition of the present invention and the glass paste prepared by using this material for the sealing part, a highly reliable crystal resonator package can be provided while taking into account the influence on environmental pollution.

[0096] The third to fifth embodiments were explained using a heat-insulating multilayer vacuum glass panel, an OLED display, and a crystal resonator package as representative examples of the sealing structural body. However, the present invention is also applicable to various other sealing structural bodies without being limited to the above-described embodiments. List of reference symbols

[0097] 1, 2: glass substrate; 3: lead-free low-melting-point glass composition; 4: low thermal expansion ceramic particles; 5: glass composite material; 6: spacer; 7: interior space; 8: glass composite material paste; 9: heat-resistant clamp; 10, 11: air-quenched soda-lime glass substrate; 12: sealing part; 13: spacer; 14: exhaust hole; 15: cap; 16: interior space; 17: heat-ray reflecting film; 18, 19: borosilicate glass substrate; 20: organic light-emitting diode (OLED); 21: laser; 22: wiring; 23: ceramic substrate; 24: conductive bonding part; 25: crystal resonator; 26: ceramic cap; 27: load.

Claims

[1] A lead-free glass composition containing vanadium oxide, tellurium oxide, alkali metal oxide, iron oxide, barium oxide and tungsten oxide, but containing substantially no phosphorus oxide, the lead-free glass composition further containing at least one of the following components: yttrium oxide, lanthanum oxide, cerium oxide, erbium oxide, ytterbium oxide, aluminum oxide and gallium oxide, wherein the proportion of tellurium oxide is 25 mol% or more and 43 mol% or less, expressed as the oxide TeO2; and wherein the proportion of the alkali metal oxide is 4 mol% or more and 27 mol% or less, expressed as oxide R2O (R: alkali metal element), where the proportions (mol%) of vanadium oxide, tellurium oxide, alkali metal oxide, iron oxide, barium oxide and tungsten oxide correspond to the following ratios, expressed as oxides: [V2O 5] < 2[R2O] + 6[Fe2O 3] + 2 [BaO] < 3.5 [V2O 5] ; [WHERE 3] < [BaO] < [R2O] + [Fe2O 3]< [V2O 5] < [TeO 2] + [R2O], and [R2O] < 6 [Fe2O3]. [2] A lead-free glass composition containing vanadium oxide, tellurium oxide, alkali metal oxide, iron oxide, barium oxide and tungsten oxide, but containing substantially no phosphorus oxide, the lead-free glass composition further containing at least one of the following components: yttrium oxide, lanthanum oxide, cerium oxide, erbium oxide, ytterbium oxide, aluminum oxide and gallium oxide, wherein the proportion of tellurium oxide is 25 mol% or more and 43 mol% or less, expressed as the oxide TeO2; and wherein the proportion of the alkali metal oxide is 4 mol% or more and 27 mol% or less, expressed as oxide R2O (R: alkali metal element), where the proportions (mol%) of the additional components, expressed as oxides, correspond to the following relationship: 2 [R2O] + 6[Fe2O 3] + 2 [BaO] + 6 [Y2O 3] + 6 [La2O3] + 4 [CeO 2]+ 6 [Er2O3] + 6 [Yb2O3] + 6 [Al2O3] + 6 [Ga2O3] < 3.5 [V2O5] . [3] A lead-free glass composition according to claim 1 or 2, wherein the alkali metal oxide is at least one of Li2O, Na2O and K2O. [4] A lead-free glass composition according to any one of claims 1 to 3, wherein the alkali metal oxide R2O is Li2O. [5] The lead-free glass composition according to any one of claims 1 to 4, wherein a second endothermic peak temperature (softening temperature) in the differential thermal analysis of the lead-free glass composition is 330°C or less, and the density of the lead-free glass composition is 3.8 g / cm 3 or less. [6] The lead-free glass composition according to any one of claims 1 to 5, wherein the content of V2O5 is 30.5 mol% or more and 45 mol% or less, the content of Fe2O3 is 2.5 mol% or more and 8 mol% or less; the content of BaO is 3 mol% or more and 10 mol% or less; and the content of WO3 is 1 mol% or more and 6 mol% or less, all expressed as oxides. [7] The lead-free glass composition according to claim 6, wherein the R2O content is 12 mol% or more and 27 mol% or less in terms of oxide. [8] The lead-free glass composition according to any one of claims 1 to 7, wherein the proportion of the additional component is 0.5 mol% or more and 4.5 mol% or less in terms of the oxides Y2O3, La2O3, CeO2, Er2O3, Yb2O3, Al2O3 and Ga2O3. [9] Lead-free glass composition according to any one of claims 1 to 8, wherein the additional component is at least one of yttrium oxide, lanthanum oxide and aluminum oxide; and wherein the proportion of the additional component is 1 mol% or more and 3 mol% or less, expressed as oxides Y2O3, La2O3 and Al2O3. [10] A glass composite material comprising the lead-free glass composition according to any one of claims 1 to 9 and ceramic particles or glass beads. [11] Glass composite material according to claim 10, wherein the proportion of the lead-free glass composition is 40 vol% or more and less than 100 vol%; and wherein the proportion of the ceramic material is more than 0 vol% and 60 vol% or less. [12] Glass composite material according to claim 11, wherein the ceramic material contains one of the following components: Zirconium phosphate tungstate (Zr2(WO4) (PO4) 2), quartz glass (SiO2), borosilicate glass (SiO2-B2O3 base), soda-lime glass (SiO2-Na2O-CaO base), β-eucryptite (Li2O·Al2O3·2SiO2), cordierite (2MgO·2Al2O3·5SiO2), zirconium silicate (ZrSiO4), alumina (Al2O3), mullite (3Al2O3·2SiO2) and niobium oxide (Nb2O3). [13] Glass composite material according to claim 11, wherein the ceramic material is one of the components zirconium phosphate tungstate (Zr2(WO4) (PO4)2) and quartz glass (SiO2); and wherein the proportion of the ceramic material is 30 vol% or more and 60 vol% or less. [14] Glass paste containing the glass composite material according to any one of claims 10 to 13, a binder and a solvent. [15] Glass paste according to claim 14, wherein polypropylene carbonate is used as a binder and dihydroterpineol is used as a solvent. [16] A sealing structural body made of the glass composite material according to any one of claims 10 to 13, comprising an inner space and a sealing part, wherein the sealing part isolates at least a part of an interface between the inner space and the outer space. [17] The sealing structural body according to claim 16, wherein the sealing structural body is in the form of a heat-insulating multi-layer vacuum glass panel, a display panel, or a housing device.

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