JP2015020914A - Manufacturing method of glass package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the reliability of a glass package by conceiving a manufacturing method of a glass package capable of enhancing, even if the thermal expansion coefficient of a glass substrate is high, the laser sealing precision.SOLUTION: The manufacturing method of a glass package provided by the present invention includes a step of preparing a first glass substrate having a thermal expansion coefficient of 55×10to 100×10/°C, a step of forming a sealing material film by coating a sealing material paste atop the first glass substrate, a step of forming a sealing material layer atop the first glass substrate by firing the sealing material film, a step of preparing a second glass substrate and laminating the first glass substrate and second glass substrate via the sealing material layer, and a step of sealing the first glass substrate and second glass substrate by irradiating the sealing material layer with a laser beam yielding a virtually elliptical irradiation spot.

Description

  The present invention relates to a method for manufacturing a glass package, and specifically relates to a method for manufacturing a glass package by a sealing process using laser light (hereinafter referred to as laser sealing).

  In recent years, non-silicon type solar cells such as dye-sensitized solar cells and thin film compound solar cells have been developed, and some have already been put into practical use.

A dye-sensitized solar cell includes a glass substrate on which a transparent conductive film is formed, a porous oxide semiconductor electrode composed of a porous oxide semiconductor layer (mainly a TiO ₂ layer) formed on the glass substrate, It is composed of a dye such as a Ru dye adsorbed on a porous oxide semiconductor electrode, an iodine electrolyte containing iodine, a glass substrate on which a catalyst film and a transparent conductive film are formed, and the like. In a thin film compound solar cell, for example, a CIGS solar cell, a chalcopyrite compound semiconductor made of Cu, In, Ga, and Se, Cu (InGa) Se ₂ is formed on a glass substrate as a photoelectric conversion film.

  These non-silicon type solar cells have a structure sandwiched between a pair of glass substrates, and a glass substrate containing an alkali metal oxide such as a high strain point glass substrate or a soda lime glass substrate is used as the glass substrate. It is done.

  Furthermore, organic EL devices such as organic EL displays and organic EL lighting have a structure in which an organic EL element is sandwiched between a pair of glass substrates. Generally, a non-alkali glass substrate is used as the glass substrate for these applications, but a glass substrate containing an alkali metal oxide, for example, a soda lime glass substrate may be used.

JP 2008-166197 A

  The constituent members (elements, etc.) of the non-silicon type solar cell are deteriorated in characteristics due to moisture or the like. For this reason, it is preferable to hermetically seal the outer peripheral edge region of the glass substrate. As a sealing material, a composite powder material containing glass powder and a refractory filler is promising. However, when the glass substrates are sealed together by baking in the softening flow temperature range of the sealing material as in the past, the characteristics of the non-silicon solar cell elements and the like may be deteriorated.

  Therefore, in recent years, laser sealing has been studied as a sealing method. According to laser sealing, since only the portion to be sealed can be locally heated, the glass substrates can be sealed together while preventing thermal degradation of the elements and the like.

  In addition, as described above, a glass substrate used for a non-silicon type solar cell or the like includes an alkali metal oxide and thus has a relatively high thermal expansion coefficient. The accuracy (success rate) of laser sealing is closely related to the thermal expansion coefficient of the glass substrate. The higher the thermal expansion coefficient of the glass substrate, the lower the accuracy of laser sealing, and the non-silicon type It becomes difficult to ensure airtightness of solar cells and the like.

  In addition, when laser sealing using a non-alkali glass substrate as in the past, the thermal expansion coefficient of the non-alkali glass substrate is low, so that the accuracy of laser sealing can be improved without taking special measures. Can do.

  Therefore, the present invention was devised in view of the above circumstances, and its technical problem is to devise a glass package manufacturing method capable of improving the accuracy of laser sealing even when the glass substrate has a high thermal expansion coefficient. This is to increase the reliability of the glass package.

As a result of intensive studies, the present inventors have found that the temperature difference (thermal expansion coefficient difference) between the region irradiated with the laser beam on the glass substrate and the vicinity thereof during laser sealing reduces the accuracy of laser sealing. If the cause is found and the energy distribution of the laser beam is made a gentle gradient, the rapid rise and fall of the glass substrate during laser sealing will be mitigated, and the accuracy of laser sealing will be significantly improved. Are proposed as the present invention. That is, the manufacturing method of the glass package of the present invention includes a step of preparing a first glass substrate having a thermal expansion coefficient of 55 × 10 ^{−7 to} 100 × 10 ⁻⁷ / ° C., and a sealing material paste as the first material. A step of coating a glass substrate to form a sealing material film; a step of firing the sealing material film to form a sealing material layer on the first glass substrate; and a second glass substrate. Preparing the first glass substrate and the second glass substrate through the sealing material layer, and irradiating the sealing material layer with a laser beam having a substantially elliptical irradiation spot, And a step of sealing the glass substrate and the second glass substrate. Here, the “thermal expansion coefficient of the glass substrate” refers to a value measured with a push rod type thermal expansion coefficient measurement (TMA) apparatus with a measurement temperature range of 30 to 380 ° C. The “substantially elliptical shape” is intended to exclude a conventional perfect circle and refers to a case where the major axis / minor axis ratio exceeds 1.0. Various lasers can be used as the “laser”. In particular, a semiconductor laser, a YAG laser, a CO ₂ laser, an excimer laser, an infrared laser, and the like are preferable in terms of easy handling.

The glass package of the present invention uses a first glass substrate having a thermal expansion coefficient of 55 × 10 ^{−7 to} 100 × 10 ⁻⁷ / ° C. This increases the allowable addition amount of the alkali metal oxide in the glass substrate and easily matches the thermal expansion coefficient of the constituent members (such as various functional films) of the non-silicon type solar cell. In addition, when there is much content of the alkali metal oxide in a glass substrate, a meltability and a moldability will improve and it will become easy to reduce the manufacturing cost of a glass substrate.

  On the other hand, if the thermal expansion coefficient of the first glass substrate is high, the accuracy of laser sealing is lowered, but in the present invention, the laser spot energy distribution is used because the irradiation spot is substantially elliptical. However, it is difficult to cause a situation in which the accuracy of laser sealing is lowered because the rapid rise and fall of the glass substrate is mitigated during laser sealing.

  In the method for producing a glass package of the present invention, it is preferable that the major axis / minor axis ratio of the irradiation spot is 1.1 or more.

  In the method for producing a glass package of the present invention, it is preferable to scan the laser beam at a speed of 0.3 mm / second or more along the sealing material layer.

  In the method for producing a glass package of the present invention, it is preferable that the direction on the longer diameter side of the irradiation spot, that is, the major axis direction is substantially aligned with the scanning direction of the laser beam. Here, the direction of the longer diameter side of the irradiation spot and the scanning direction of the laser beam are different not only in the case of being completely coincident but also in the range of ± 20 °, preferably ± 10 °, more preferably ± 5 °. This includes cases where

  In the method for producing a glass package of the present invention, the average thickness of the sealing material layer is preferably less than 10 μm. If it does in this way, the stress which remain | survives in a sealing part or a glass substrate after laser sealing can be reduced. As a result, even if the thermal expansion coefficient of the glass substrate is high, it is easy to prevent the occurrence of cracks or the like in the sealed portion or the glass substrate. Here, the “average thickness of the sealing material layer” can be measured by, for example, a non-contact type laser film thickness meter.

In the method for producing a glass package of the present invention, the second glass substrate preferably has a thermal expansion coefficient of 55 × 10 ^{−7 to} 100 × 10 ⁻⁷ / ° C.

  It is preferable that the manufacturing method of the glass package of this invention irradiates a laser beam from the 1st glass substrate side. In this way, the sealing strength can be increased.

  In the manufacturing method of the glass package of the present invention, it is preferable to apply the sealing material paste in a frame shape along the outer peripheral edge region of the first glass substrate. In this way, the effective area that functions as a device can be expanded.

In the method for producing a glass package of the present invention, the difference in thermal expansion coefficient between the first glass substrate and the sealing material layer is less than 30 × 10 ⁻⁷ / ° C., and the second glass substrate and the sealing material layer The difference in thermal expansion coefficient is preferably less than 30 × 10 ⁻⁷ / ° C. Here, the “thermal expansion coefficient of the sealing material layer” refers to a value measured with a push rod type thermal expansion coefficient measurement (TMA) apparatus with a measurement temperature range of 30 to 300 ° C.

  In the method for producing a glass package of the present invention, the thickness of the first glass substrate is 0.5 mm or more and less than 2.8 mm, and the thickness of the second glass substrate is 0.5 mm or more and less than 2.8 mm. It is preferable.

In the method for producing a glass package of the present invention, the first glass substrate contains 1% by mass or more of Na ₂ O as a glass composition, and the second glass substrate contains 1% by mass of Na ₂ O as a glass composition. It is preferable to include the above.

In the method for producing a glass package of the present invention, the sealing material paste contains a sealing material and a vehicle, and the sealing material is 55 to 95% by volume of bismuth-based glass and 5 to 45% by volume of a refractory filler. It is preferable to contain. Bismuth glass generally has a thermal expansion coefficient in an appropriate range (for example, 90 to 120 × 10 ⁻⁷ / ° C.). Thereby, even if it does not add a fireproof filler excessively, it can be matched with the thermal expansion coefficient of a glass substrate. Bismuth glass has a low melting point but high thermal stability (devitrification resistance). Thereby, it can soften and flow well at the time of laser sealing, and the accuracy of laser sealing can be increased. Furthermore, bismuth-based glass reacts well with the glass substrate during laser sealing. Thereby, sealing strength can be raised. The “bismuth-based glass” refers to glass containing Bi ₂ O ₃ as a main component, and specifically refers to glass containing 50% by mass or more of Bi ₂ O ₃ in the glass composition.

  If a refractory filler is added, the thermal expansion coefficients of the glass substrate and the sealing material layer can be easily matched, and the mechanical strength of the sealing material layer can be increased.

  In the method for producing a glass package of the present invention, the bismuth-based glass preferably contains 0.5% by mass or more of a transition metal oxide as a glass composition. In this way, the light absorption characteristics of the sealing material layer are improved.

In the method for producing a glass package of the present invention, the bismuth-based glass has a glass composition of mass%, Bi ₂ O ₃ 67 to 87%, B ₂ O ₃ 2 to 12%, ZnO 1 to 20%, CuO + Fe ₂ O. ₃ It is preferable to contain 0.5 to 18%. In this way, it is possible to perform laser sealing at a low temperature while ensuring the thermal stability of the bismuth-based glass. Here, “CuO + Fe ₂ O ₃ ” is the total amount of CuO and Fe ₂ O ₃ .

Method for manufacturing a glass package of the present invention preferably has a maximum particle diameter D ₉₉ of the refractory filler is less than 5 [mu] m. In this way, the surface smoothness of the sealing material layer is improved, and the accuracy of laser sealing can be increased. Here, the “maximum particle diameter D ₉₉ ” indicates a value measured by the laser diffraction method. In the cumulative particle size distribution curve based on the volume when measured by the laser diffraction method, the accumulated amount is accumulated from the smaller particle. Represents a particle size of 99%.

  In the method for producing a glass package of the present invention, the glass package is preferably any one of a non-silicon type solar cell, an organic EL device, and a lithium ion secondary battery.

It is a cross-sectional conceptual diagram for demonstrating the manufacturing method of the glass package of this invention. It is a plane conceptual diagram for demonstrating the manufacturing method of the glass package of this invention. It is explanatory drawing which shows the scanning example of the laser beam in the manufacturing method of the glass package of this invention. Sample No. in Table 3 It is the data which shows the spot shape of the laser beam used for sealing of 1 glass package. Sample No. in Table 3 5 is data showing a spot shape of a laser beam used for sealing a glass package of No. 5;

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a conceptual cross-sectional view for explaining the glass package manufacturing method of the present invention. As shown in FIG. 1A, a sealing material layer 2 is formed in the outer peripheral edge region of the first glass substrate 1. The sealing material layer 2 is formed by applying a sealing material paste onto the first glass substrate 1 to form a sealing material film, and then baking the sealing material film. Next, as shown in FIGS. 1A and 1B, a second glass substrate 3 is prepared, and the first glass substrate 1 and the second glass substrate 3 are interposed via the sealing material layer 2. Overlapping. Subsequently, as shown in FIG. 1 (c), the sealing material layer 2 is irradiated with laser light 4 whose irradiation spot is substantially elliptical from the first glass substrate 1 side, and the first glass substrate 1. And the second glass substrate 3 are sealed. Finally, as shown in FIG. 1 (d), when the laser beam 4 is scanned along the sealing material layer 2, the first glass substrate 1 and the second glass substrate 3 are sealed to form a glass package. Can be obtained.

  FIG. 2 is a conceptual plan view for explaining the glass package manufacturing method of the present invention. As shown in FIG. 2, a sealing material layer 6 is formed in a frame shape on the first glass substrate 5 along the outer peripheral edge region. In FIG. 2, the sealing material layer 6 indicated by a dotted line is located below the first glass substrate 5.

  FIG. 3 is an explanatory view showing a scanning example of the laser light 7 in the method for manufacturing a glass package of the present invention. As shown in FIG. 3, the laser beam 7 is scanned from the irradiation start position S of the laser beam 7 along the sealing material layer 8, and the irradiation and scanning of the laser beam 7 are completed at the irradiation end position E of the laser beam 7. . The irradiation spot 9 of the laser beam 7 is substantially elliptical. The direction of the longer diameter side of the irradiation spot 9 and the scanning direction of the laser light 7 are substantially aligned. As a result, the rapid rise and fall of the first glass substrate and the second glass substrate are alleviated, and the accuracy of laser sealing is significantly improved.

  Hereinafter, a suitable embodiment is described in detail about the manufacturing method of the glass package of the present invention.

In the method for producing a glass package of the present invention, a first glass substrate having a thermal expansion coefficient of 55 × 10 ^{−7 to} 100 × 10 ⁻⁷ / ° C. is used. Suitable lower limit ranges of the thermal expansion coefficient of the first glass substrate are 65 × 10 ⁻⁷ / ° C. or higher, 70 × 10 ⁻⁷ / ° C. or higher, 75 × 10 ⁻⁷ / ° C. or higher, particularly 80 × 10 ⁻⁷ / ° C. Thus, the preferable upper limit range is 95 × 10 ⁻⁷ / ° C. or lower, 90 × 10 ⁻⁷ / ° C. or lower, particularly 88 × 10 ⁻⁷ / ° C. or lower. In this way, the allowable addition amount of the alkali metal oxide in the first glass substrate increases, and it becomes easy to match the thermal expansion coefficient of components (such as various functional films) such as non-silicon type solar cells. .

In the method for producing a glass package of the present invention, the second glass substrate is used, and the thermal expansion coefficient of the second glass substrate is preferably 55 × 10 ^{−7 to} 100 × 10 ⁻⁷ / ° C. Suitable lower limit ranges of the thermal expansion coefficient of the second glass substrate are 65 × 10 ⁻⁷ / ° C. or higher, 70 × 10 ⁻⁷ / ° C. or higher, 75 × 10 ⁻⁷ / ° C. or higher, particularly 80 × 10 ⁻⁷ / ° C. Thus, the preferable upper limit range is 95 × 10 ⁻⁷ / ° C. or lower, 90 × 10 ⁻⁷ / ° C. or lower, particularly 88 × 10 ⁻⁷ / ° C. or lower. This increases the allowable amount of alkali metal oxide added to the glass substrate of the second glass substrate and matches the thermal expansion coefficient of components (such as various functional films) such as non-silicon solar cells. It becomes easy to do.

The glass substrate (first glass substrate and / or second glass substrate) has a glass composition of Na ₂ O of 1% by mass or more (preferably 2 to 15% by mass, more preferably 3.5 to 13% by mass). More preferably, it is more than 4.3 to 10% by mass). In this way, the thermal expansion coefficient of the glass substrate can be easily regulated to 55 × 10 ⁻⁷ / ° C. or more, and the meltability and formability are improved, so that the manufacturing cost of the glass substrate can be easily reduced. Na ₂ O is an effective component for the growth of chalcopyrite crystals when producing a CIGS solar cell, and is an important component for increasing the photoelectric conversion efficiency.

The glass substrate (first glass substrate and / or second glass substrate) has a glass composition of Na ₂ O of 1% by mass or more (preferably 2 to 15% by mass, more preferably 3.5 to 13% by mass). More preferably, it is more than 4.3 to 10% by mass). In this way, the thermal expansion coefficient of the glass substrate can be easily regulated to 55 × 10 ⁻⁷ / ° C. or more, and the meltability and formability are improved, so that the manufacturing cost of the glass substrate can be easily reduced. Na ₂ O is an effective component for the growth of chalcopyrite crystals when producing a CIGS solar cell, and is an important component for increasing the photoelectric conversion efficiency.

A glass substrate (first glass substrate and / or the second glass substrate) is a glass composition including, in _{mass%, SiO 2 40~70%, Al} 2 O 3 3~20%, B 2 O 3 0~15 %, Li ₂ O 0-10%, Na ₂ O 1-20%, K ₂ O 0-15%, MgO + CaO + SrO + BaO 5-35%, ZrO ₂ 0-10%. If it does in this way, it will become easy to achieve a high strain point, improving meltability, moldability, and thermal stability. If the glass substrate is made to have a high strain point, the glass substrate is less likely to undergo thermal contraction or thermal deformation in the heat treatment process when manufacturing a non-silicon type solar cell or the like, and various functional films (photoelectric conversion films, etc.) The quality can be improved.

  The plate thickness of the glass substrate (first glass substrate and / or second glass substrate) is preferably 0.5 mm or more and less than 2.8 mm, 0.7 mm or more and less than 2.8 mm, 1.0 mm or more and less than 2.5 mm. In particular, it is 1.5 mm or more and less than 2.0 mm. When the plate thickness of the glass substrate is less than 0.5 mm, the production efficiency of the glass substrate tends to be lowered. On the other hand, when the plate thickness of the glass substrate is 2.8 mm or more, it is difficult to reduce the weight of the glass package.

On the surface of the glass substrate (the first glass substrate and / or the second glass substrate), a protective film such as SiO ₂ or SiN may be formed, and an electrode film such as a transparent conductive film is formed. May be.

  The method for producing a glass package of the present invention includes a step of applying a sealing material paste onto a first glass substrate to form a sealing material film. As a method for applying the sealing material paste, a known method can be used. In particular, a method of applying the sealing material paste onto the first glass substrate using a screen printer is preferable from the viewpoint of application accuracy. Next, the sealing material film is dried to volatilize the solvent. Subsequently, firing is performed at a temperature higher than the softening point of the sealing material, the resin component in the sealing material paste is incinerated (binder removal treatment), and the sealing material is sintered (fixed), and the first glass substrate A sealing material layer is formed thereon.

  The sealing material paste generally includes a sealing material and a vehicle. Although various materials can be used as the sealing material, a composite powder containing glass and a refractory filler is preferable. If it does in this way, it will become easy to match the thermal expansion coefficient of a sealing material with the thermal expansion coefficient of a glass substrate, making low melting point characteristics and mechanical strength compatible.

  The sealing material preferably contains 55 to 95 volume% glass (especially bismuth glass) and 5 to 45 volume% refractory filler, 60 to 90 volume% glass and 10 to 40 volume% refractory. It is more preferable to contain a flammable filler, and it is particularly preferable to contain 60 to 85% by volume of glass and 15 to 40% by volume of a refractory filler. If a predetermined amount of refractory filler is added to the glass, the thermal expansion coefficient of the sealing material can easily match the thermal expansion coefficient of the glass substrate. As a result, it becomes easy to prevent a situation in which undue stress remains on the sealed portion or the glass substrate after laser sealing. On the other hand, when the content of the refractory filler is too large, the glass content is relatively decreased, so that the surface smoothness of the sealing material layer is lowered, and the accuracy of laser sealing is easily lowered.

Various glasses can be used as the glass. Among them, tin phosphate glass, vanadium glass, and bismuth glass are preferable from the viewpoint of water resistance and thermal stability, and bismuth glass is particularly preferable. is there. Here, the “tin phosphate glass” refers to a glass mainly composed of SnO and P ₂ O ₅ , specifically, SnO and P ₂ O ₅ in a total amount of 40% by mass or more in the glass composition. Refers to glass containing. “Vanadium-based glass” refers to glass mainly composed of V ₂ O ₅ , and specifically refers to glass containing 25% by mass or more of V ₂ O ₅ in the total amount in the glass composition.

  The bismuth-based glass has a transition metal oxide content of 0.5% by mass or more (preferably 2 to 18% by mass, more preferably 3 to 15% by mass, still more preferably 4 to 12% by mass, particularly preferably glass composition). 5-10% by mass) is desirable. If it does in this way, light absorption characteristics can be improved, suppressing a fall of thermal stability.

Bismuth glass contains, as a glass composition, mass%, Bi ₂ O ₃ 67 to 90%, B ₂ O ₃ 2 to 12%, ZnO 1 to 20%, CuO + Fe ₂ O ₃ 0.5 to 18%. It is preferable. The reason for limiting the content of each component as described above will be described below.

Bi ₂ O ₃ is a main component for lowering the softening point, and its content is 67 to 87%, preferably 70 to 85%, more preferably 72 to 83%. If the content of Bi ₂ O ₃ is less than 67%, the softening point becomes too high, and the glass is difficult to soften even when irradiated with laser light. On the other hand, when the content of Bi ₂ O ₃ is more than 90%, the glass becomes thermally unstable, and the glass tends to devitrify when melted, sintered (fixed), or sealed with laser.

B ₂ O ₃ is a component that forms a glass network of bismuth-based glass, and its content is 2 to 12%, preferably 3 to 10%, more preferably 4 to 10%, still more preferably 5 to 9%. It is. When the content of B ₂ O ₃ is less than 2%, the glass becomes thermally unstable, and the glass tends to be devitrified during melting, sintering (adhering), or laser sealing. On the other hand, if the content of B ₂ O ₃ is more than 12%, the softening point becomes too high and the glass is difficult to soften even when irradiated with laser light.

  ZnO is a component that suppresses devitrification at the time of melting, sintering (adhering), or laser sealing, and lowers the thermal expansion coefficient, and its content is 1 to 20%, preferably 2 to 15 %, More preferably 3 to 11%, still more preferably 3 to 9%. If the ZnO content is less than 1%, it is difficult to obtain the above effect. On the other hand, if the ZnO content is more than 20%, the component balance in the glass composition is impaired, and conversely, the glass tends to devitrify.

CuO + Fe ₂ O ₃ is a component having light absorption characteristics, and when irradiated with laser light having a predetermined emission center wavelength, CuO + Fe ₂ O ₃ is a component that easily absorbs the laser light and softens the glass. CuO + Fe ₂ O ₃ is a component that suppresses devitrification at the time of melting, sintering (adhering), or laser sealing. The content of CuO + Fe ₂ O ₃ is 0.5 to 18%, preferably 3 to 15%, more preferably 3.5 to 15%, still more preferably 4 to 12%, and particularly preferably 5 to 10%. If the content of CuO + Fe ₂ O ₃ is less than 0.5%, the light absorption characteristics are poor, and the glass is difficult to soften even when irradiated with laser light. On the other hand, when the content of CuO + Fe ₂ O ₃ is more than 18 percent, is impaired balance of components in the glass composition, the glass is liable to devitrify reversed.

  CuO is a component having light absorption characteristics. When irradiated with a laser beam having a predetermined emission center wavelength, CuO is a component that absorbs the laser beam and softens the glass. ) Or a component that suppresses devitrification at the time of laser sealing. The content of CuO is preferably 0 to 15%, 1 to 15%, 2 to 12%, 3 to 10%, particularly 4.5 to 10%. When there is more content of CuO than 15%, the component balance in a glass composition will be impaired and it will become easy to devitrify glass conversely. If the CuO content is restricted to 1% or more, the light absorption characteristics are improved, and the glass is easily softened during laser sealing.

Fe ₂ O _{3 is} also a component having light absorption characteristics. When irradiated with laser light having a predetermined emission center wavelength, it is a component that absorbs laser light and softens the glass easily. It is a component that suppresses devitrification at the time of bonding (fixing) or laser sealing. The content of Fe ₂ O ₃ is preferably 0 to 7%, 0.05 to 7%, 0.1 to 4%, particularly 0.2 to 3%. When the content of Fe ₂ O ₃ is more than 7%, is impaired balance of components in the glass composition, the glass is liable to devitrify reversed. If the content of Fe ₂ O ₃ is regulated to 0.05% or more, the light absorption characteristics are improved, and the glass is easily softened during laser sealing.

Fe ions in iron oxide exist in the state of Fe ²⁺ or Fe ³⁺ . In the present invention, Fe ions in iron oxide are not limited to either Fe ²⁺ or Fe ³⁺ , and may be any. Therefore, in the present invention, even Fe ²⁺ is handled after being converted to Fe ₂ O ₃ . In particular, when an infrared laser is used as the irradiation light, since Fe ²⁺ has an absorption peak in the infrared region, the ratio of Fe ²⁺ is preferably large. For example, the ratio of Fe ²⁺ / Fe ^{3+ in} iron oxide is 0. It is preferable to regulate to 0.03 or more (preferably 0.08 or more).

  In addition to the above components, for example, the following components may be added.

SiO ₂ is a component that improves water resistance. The content of SiO ₂ is preferably 0 to 10%, 0 to 3%, especially 0 to less than 1%. If the content of SiO ₂ is more than 10%, the softening point becomes too high, and the glass is difficult to soften even when irradiated with laser light.

Al ₂ O ₃ is a component that improves water resistance. The content of Al ₂ O ₃ is preferably 0 to 5%, 0 to 2%, particularly 0 to less than 0.5%. When the content of Al ₂ O ₃ is more than 5%, the softening point becomes too high and the glass is difficult to soften even when irradiated with laser light.

  MgO + CaO + SrO + BaO (total amount of MgO, CaO, SrO and BaO) is a component that suppresses devitrification at the time of melting, sintering (adhering), or laser sealing, and the content of MgO + CaO + SrO + BaO is preferably 0 to 15%, in particular 0-10%. If the content of MgO + CaO + SrO + BaO is more than 15%, the softening point becomes too high, and the glass is difficult to soften even when irradiated with laser light.

  MgO, CaO, and SrO are components that suppress devitrification during melting, sintering (adhering), or laser sealing. The content of each component is preferably 0 to 5%, particularly 0 to 2%. When the content of each component is more than 5%, the softening point becomes too high, and the glass is difficult to soften even when irradiated with laser light.

  BaO is a component that suppresses devitrification during melting, sintering (adhering), or laser sealing. The content of BaO is preferably 0 to 10%, in particular 0 to 8%. When the content of BaO is more than 10%, the softening point becomes too high and the glass is difficult to soften even when irradiated with laser light.

CeO ₂ and Sb ₂ O ₃ are components that suppress devitrification during melting, sintering (adhering), or laser sealing. The content of each component is preferably 0 to 5%, 0 to 2%, particularly 0 to 1%. When there is more content of each component than 5%, the component balance in a glass composition will be impaired, and conversely, it will become easy to devitrify glass. From the viewpoint of enhancing the thermal stability, it is preferable to add a small amount of Sb ₂ O ₃ , and specifically, it is preferable to add 0.05% or more of Sb ₂ O ₃ .

WO ₃ is a component that suppresses devitrification at the time of melting, sintering (adhering), or laser sealing. The content of WO ₃ is preferably 0 to 10%, in particular 0 to 2%. When the content of WO ₃ is more than 10%, the component balance in the glass composition is impaired, and conversely, the glass is easily devitrified.

In ₂ O ₃ + Ga ₂ O ₃ (total amount of In ₂ O ₃ and Ga ₂ O ₃ ) is a component that suppresses devitrification at the time of melting, sintering (adhering), or laser sealing. The content of In ₂ O ₃ + Ga ₂ O ₃ is preferably 0 to 5%, particularly 0 to 3%. If the content of In ₂ O ₃ + Ga ₂ O ₃ is more than 5%, the batch cost increases. In addition, the content of In ₂ O ₃ is more preferably 0 to 1%, and the content of Ga ₂ O ₃ is more preferably 0 to 0.5%.

  The oxides of Li, Na, K, and Cs are components that lower the softening point. However, since they have an action of promoting devitrification at the time of melting, the total amount is preferably regulated to less than 1%.

P ₂ O ₅ is a component that suppresses devitrification at the time of melting. However, if the content of P ₂ O ₅ is more than 1%, the glass tends to undergo phase separation during melting.

_{La 2 O 3, Y 2 O} 3 and _Gd 2 _{O 3} is a component to suppress phase separation during melting, when these total amount is more than 3%, the softening point becomes too high, the laser beam Even when irradiated, the glass becomes difficult to soften.

NiO, V ₂ O ₅ , CoO, MoO ₃ , TiO _2, and MnO ₂ are components having light absorption characteristics. When irradiated with laser light having a predetermined emission center wavelength, the laser light is absorbed and glass is absorbed. It is a component that facilitates softening. The content of each component is preferably 0 to 7%, particularly 0 to 3%. If the content of each component is more than 7%, the glass tends to be devitrified during laser sealing.

  PbO is a component that lowers the softening point, but it is a component that is concerned about environmental effects. Therefore, the content of PbO is preferably less than 0.1%.

  Even if it is a component other than the above, you may add to 5%, for example in the range which does not impair a glass characteristic.

  As the refractory filler, it is preferable to use one or more selected from cordierite, zircon, tin oxide, niobium oxide, zirconium phosphate ceramic, and willemite. These refractory fillers have a low thermal expansion coefficient, a high mechanical strength, and a good compatibility with bismuth glass. Of the above refractory fillers, cordierite is most preferred. Cordierite has a property that it is difficult to devitrify the bismuth glass even when the particle size is small, even when laser sealing. In addition to the above refractory filler, β-eucryptite, quartz glass and the like may be added.

The average particle size D ₅₀ of the refractory filler is preferably less than 2 μm, in particular less than 1.8 μm. When the average particle diameter D ₅₀ of the refractory filler is less than 2 μm, the surface smoothness of the sealing material layer is improved and the average thickness of the sealing material layer is easily regulated to less than 10 μm. The accuracy of wearing can be increased.

Maximum particle diameter _{D 99} of the refractory filler is preferably less than 5 [mu] m, 4 [mu] m or less, particularly 3μm or less. When the maximum particle diameter D ₉₉ of the refractory filler is less than 5 [mu] m, together with the surface smoothness of the sealing material layer is improved, easily regulate the average thickness of the sealing material layer less than 10 [mu] m, as a result, the laser sealing The accuracy of wearing can be increased.

The thermal expansion coefficient of the sealing material is preferably 60 × 10 ^{−7 to} 95 × 10 ⁻⁷ / ° C., 66 × 10 ^{−7 to} 90 × 10 ⁻⁷ / ° C., particularly 72 × 10 ^{−7 to} 88 × 10 ^{− 7} / ° C. In this way, the thermal expansion coefficient of the sealing material layer can be easily matched to the thermal expansion coefficient of the glass substrate, and the content of the refractory filler can be reduced, so that the sealing material layer softens and flows during laser sealing. It becomes easy to do.

  The softening point of the sealing material is preferably 460 ° C. or lower, 450 ° C. or lower, particularly 430 ° C. or lower. When the softening point is higher than 460 ° C., the sealing material is softened and hardly flows during laser sealing. The lower limit of the softening point is not particularly set, but considering the thermal stability of the glass, the softening point is preferably 350 ° C. or higher. Here, the “softening point” refers to a value measured with a macro-type differential thermal analysis (DTA) apparatus in an air atmosphere, DTA starts measurement from room temperature, and the rate of temperature rise is 10 ° C./min. . In addition, the softening point measured with the macro type | mold DTA apparatus points out the temperature (Ts) of the 4th bending point shown in FIG.

  The sealing material may further contain a laser absorbing material in order to enhance the light absorption property, but the laser absorbing material has an action of promoting devitrification of the bismuth-based glass. Therefore, the content of the laser absorber is preferably 0 to 10% by volume, 0 to 5% by volume, particularly 0 to 3% by volume. When the content of the laser absorbing material is more than 10% by volume, the glass tends to be devitrified at the time of laser sealing. Cu-based oxides, Fe-based oxides, Cr-based oxides, Mn-based oxides and spinel complex oxides thereof can be used as the laser absorber, and in particular, from the viewpoint of compatibility with bismuth-based glass. Therefore, a Mn-based oxide (for example, 42-343B manufactured by Toago Material Co., Ltd.) is preferable. In addition, when adding a laser absorber, the content is 0.1 volume% or more, 0.5 volume% or more, 1 volume% or more, and especially 2 volume% or more is preferable.

  A vehicle usually includes a resin and a solvent. As the resin used for the vehicle, acrylic ester (acrylic resin), ethyl cellulose, polyethylene glycol derivative, nitrocellulose, polymethylstyrene, polyethylene carbonate, polypropylene carbonate, methacrylic ester and the like can be used.

  Solvents used in the vehicle include N, N′-dimethylformamide (DMF), α-terpineol, higher alcohol, γ-butyllactone (γ-BL), tetralin, butyl carbitol acetate, ethyl acetate, isoamyl acetate, diethylene glycol mono Ethyl ether, diethylene glycol monoethyl ether acetate, benzyl alcohol, toluene, 3-methoxy-3-methylbutanol, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl Ether, tripropylene glycol monobutyl ether, propylene carbonate, dimethyl sulfoxide (D SO), N-methyl-2-pyrrolidone and the like can be used. In particular, α-terpineol is preferable because it is highly viscous and has good solubility in resins and the like.

  The thickness variation of the sealing material layer after forming the sealing material layer on the first glass substrate is preferably 2 μm or less, particularly preferably 1 μm or less. If it does in this way, the adhesiveness of a 1st glass substrate and a 2nd glass substrate will improve. The “thickness variation of the sealing material layer” can be measured by, for example, a non-contact type laser film thickness meter.

  After the sealing material layer is formed on the first glass substrate, the surface of the sealing material layer may be polished to improve the surface smoothness of the sealing material layer. Polishing is preferred. In this way, the polishing process becomes unnecessary, and the manufacturing cost can be easily reduced.

The difference in thermal expansion coefficient between the first glass substrate and the sealing material layer is less than 30 × 10 ⁻⁷ / ° C., less than 25 × 10 ⁻⁷ / ° C., less than 20 × 10 ⁻⁷ / ° C., and 15 × 10 ⁻⁷ / It is preferable to regulate to less than 10 ° C., less than 12 × 10 ⁻⁷ / ° C., particularly less than 10 × 10 ⁻⁷ / ° C. If it does in this way, the stress which remains in a sealing part or a 1st glass substrate after laser sealing can be reduced. As a result, it becomes easy to prevent the sealing part and the crack of the first glass substrate after laser sealing.

Further, the difference in thermal expansion coefficient between the second glass substrate and the sealing material layer is less than 30 × 10 ⁻⁷ / ° C., less than 25 × 10 ⁻⁷ / ° C., less than 20 × 10 ⁻⁷ / ° C., and 15 × 10 ⁻ It is preferable to regulate to less than ⁷ / ° C., less than 12 × 10 ⁻⁷ / ° C., particularly less than 10 × 10 ⁻⁷ / ° C. If it does in this way, the stress which remains in a sealing part or a 2nd glass substrate after laser sealing can be reduced. As a result, it becomes easy to prevent the sealing part and the crack of the second glass substrate after laser sealing.

  The thermal expansion coefficient of the sealing material layer is preferably lower than the thermal expansion coefficient of the first glass substrate and / or the second glass substrate. In this way, compressive stress is generated in the sealed portion after laser sealing, and the reliability of the sealed portion is improved.

  It is preferable to regulate the average thickness of the sealing material layer after forming the sealing material layer on the first glass substrate to be less than 10 μm, less than 7 μm, less than 6 μm, and particularly less than 5 μm. The smaller the average thickness of the sealing material layer, the lower the stress remaining on the sealed portion and the glass substrate after laser sealing. As a result, even if the thermal expansion coefficient of the glass substrate is high, the accuracy of laser sealing can be increased.

  The surface roughness Ra of the sealing material layer after forming the sealing material layer on the first glass substrate is less than 0.5 μm, 0.3 μm or less, 0.2 μm or less, particularly 0.01 to 0.15 μm. It is preferable to regulate. If it does in this way, the adhesiveness of a 1st glass substrate and a 2nd glass substrate will improve, and the precision of laser sealing will improve. “Surface roughness Ra” can be measured by, for example, a non-contact type laser film thickness meter or a surface roughness meter.

  The surface roughness RMS of the sealing material layer after forming the sealing material layer on the first glass substrate is less than 1.0 μm, 0.7 μm or less, 0.5 μm or less, particularly 0.05 to 0.3 μm. It is preferable to regulate. If it does in this way, the adhesiveness of a 1st glass substrate and a 2nd glass substrate will improve, and the precision of laser sealing will improve. Here, the “surface roughness RMS” can be measured by, for example, a non-contact type laser film thickness meter or a surface roughness meter.

  In the method for producing a glass package of the present invention, the sealing material layer is irradiated with laser light whose irradiation spot is substantially elliptical. The major axis / minor axis ratio of the irradiation spot is preferably 1.1 or more, 1.1 or more, 1.2 or more, 1.3 or more, 1.4 or more, 1.5 or more, 1.6 or more, particularly 1. 7 to 4.5. If the major axis / minor axis ratio of the irradiation spot is too small, the temperature difference (thermal expansion coefficient difference) between the region irradiated with the laser beam on the glass substrate and its neighboring region becomes excessive during laser sealing, and the laser sealing is performed. The accuracy of wearing tends to decrease. The major axis / minor axis ratio of the irradiation spot can be adjusted by changing the condenser lens.

  The scanning speed of the laser beam is preferably 0.3 mm / second or more, 0.4 mm / second or more, 0.5 mm / second or more, 0.6 mm / second or more, 0.7 mm / second or more, 0.8 mm / second or more. In particular, it is 0.9 mm / second or more. When the irradiation speed of the laser beam is too low, the efficiency of the laser beam is likely to decrease.

  Hereinafter, the present invention will be described in detail based on examples. The following examples are merely illustrative. The present invention is not limited to the following examples.

  Table 1 shows the glass composition of the bismuth glass.

  Each sample shown in Table 1 was prepared as follows. First, a glass batch in which raw materials such as various oxides and carbonates were prepared so as to have the glass composition shown in Table 1 was prepared, and this was put in a platinum crucible and melted at 1100 ° C. for 1 hour. Next, the obtained molten glass was formed into a thin piece with a water-cooled roller. Finally, the obtained glass film was pulverized with a ball mill and then air-classified to obtain a bismuth-based glass having a particle size shown in Table 2.

  The glass transition point is a value measured with a push rod TMA apparatus.

  The thermal expansion coefficient is a value measured by a push rod type TMA apparatus. The measurement temperature range was 30 to 300 ° C.

  The sealing material was produced by mixing the bismuth-based glass powder produced above and a refractory filler. Cordierite having the particle size shown in Table 2 was used as the refractory filler. About this sealing material, the glass transition point, the softening point, and the thermal expansion coefficient were measured. The results are shown in Table 2.

  The glass transition point is a value measured with a push rod TMA apparatus.

  The softening point is a value measured with a macro DTA apparatus. The measurement was performed in an air atmosphere at a temperature rising rate of 10 ° C./min, and the measurement was performed from room temperature to 600 ° C.

  The thermal expansion coefficient is a value measured by a push rod type TMA apparatus. The measurement temperature range was 30 to 300 ° C.

  A glass substrate with a sealing material layer was produced as follows. First, the sealing material and the vehicle were kneaded so as to have a viscosity of about 70 Pa · s (25 ° C., Shear rate: 4), and then kneaded with a three-roll mill until uniform, thereby forming a paste. Polyethylene carbonate (MW: 129000) was used as the resin component in the vehicle, and propylene carbonate was used as the solvent component. A vehicle in which 25% by mass of polyethylene carbonate was dissolved in propylene carbonate was used. Next, along the outer peripheral edge region of the glass substrate (first glass substrate) having a length of 50 mm × width of 50 mm × thickness of 1.0 mm, the above-mentioned sealing material paste has a thickness of about 5 μm and a width of about 0.6 mm. After being printed in a frame shape with a screen printer, dried at 85 ° C. for 15 minutes in an air atmosphere, and then baked at 485 ° C. for 10 minutes in an air atmosphere to obtain a sealing material The resin component in the paste was incinerated (debinding treatment) and the sealing material was sintered (fixed) to obtain a glass substrate with a sealing material layer having an average thickness shown in the table.

  The average thickness of the sealing material layer is a value measured with a non-contact type laser film thickness meter.

  Subsequently, a glass substrate (second glass substrate) having a length of 50 mm, a width of 50 mm, and a thickness of 1.0 mm is disposed on the sealing material layer in an air atmosphere, and then a glass substrate having a sealing material layer (first The glass substrate is softened and fluidized by irradiating a laser beam having a wavelength of 808 nm along the sealing material layer from the glass substrate side at the output and scanning speed shown in Table 3, and the glass substrates are bonded to each other. The sample No. 1 to 5 glass packages were obtained.

  Sample No. When producing the glass packages according to 1 to 4, the spot shape of the laser beam used was substantially elliptical, and the major axis / minor axis ratio is as shown in Table 3. The elliptical shape of the laser beam was adjusted by changing the condenser lens. Sample No. In the production of 5, the spot shape of the laser beam used is a true circle.

  FIG. 1 shows the spot shape of the laser beam used when the glass package according to 1 is manufactured. FIG. 5 shows the spot shape of a conventional laser beam. 5 shows the spot shape of the laser beam used when the glass package according to 5 is manufactured.

“Soda lime” described in Table 3 refers to a soda lime glass substrate, and the thermal expansion coefficient at 30 to 380 ° C. is 79 × 10 ⁻⁷ / ° C. “High strain point glass” refers to PP-8C manufactured by Nippon Electric Glass Co., Ltd., and its thermal expansion coefficient at 30 to 380 ° C. is 83 × 10 ⁻⁷ / ° C.

  The airtightness was evaluated by observing the sealing state of the glass package. The glass substrates were hermetically sealed and evaluated as “◯” when no crack or peeling was observed, and “X” when crack or peeling was observed.

  The method for producing a glass package of the present invention includes, for example, non-silicon solar cells such as dye-sensitized solar cells and thin film compound solar cells, lithium ion secondary batteries, organic EL displays, and organic EL devices such as organic EL lighting. It is suitable as a manufacturing method.

1, 5 First glass substrate 2, 6, 8 Sealing material layer 3 Second glass substrate 4, 7 Laser beam 9 Irradiation spot

Claims (16)

Preparing a first glass substrate having a thermal expansion coefficient of 55 × 10 ^{−7 to} 100 × 10 ⁻⁷ / ° C .;
Applying a sealing material paste on the first glass substrate to form a sealing material film;
Baking the sealing material film to form a sealing material layer on the first glass substrate;
Preparing a second glass substrate and superimposing the first glass substrate and the second glass substrate via a sealing material layer;
Irradiating the sealing material layer with laser light having an irradiation spot having a substantially elliptical shape, and sealing the first glass substrate and the second glass substrate. Method.   2. The method for producing a glass package according to claim 1, wherein a major axis / minor axis ratio of the irradiation spot is 1.1 or more.   The method for producing a glass package according to claim 1 or 2, wherein the laser beam is scanned along the sealing material layer at a speed of 0.3 mm / second or more.   The method for producing a glass package according to any one of claims 1 to 3, wherein the direction of the longer diameter side of the irradiation spot is substantially aligned with the scanning direction of the laser beam.   The average thickness of a sealing material layer is less than 10 micrometers, The manufacturing method of the glass package in any one of Claims 1-4 characterized by the above-mentioned. Method of manufacturing a glass package according to claim 1, the thermal expansion coefficient of the second glass substrate is characterized in that it is a ^{55 × 10 -7 ~100 × 10 -7} / ℃.   The method for producing a glass package according to claim 1, wherein laser light is irradiated from the first glass substrate side.   The method for manufacturing a glass package according to any one of claims 1 to 7, wherein a sealing material paste is applied in a frame shape along an outer peripheral edge region of the first glass substrate. The difference in thermal expansion coefficient between the first glass substrate and the sealing material layer is less than 30 × 10 ⁻⁷ / ° C., and the difference in thermal expansion coefficient between the second glass substrate and the sealing material layer is 30 × 10 ⁻ It is less than ⁷ / degreeC, The manufacturing method of the glass package in any one of Claims 1-8 characterized by the above-mentioned.   The plate thickness of the first glass substrate is 0.5 mm or more and less than 2.8 mm, and the plate thickness of the second glass substrate is 0.5 mm or more and less than 2.8 mm. The manufacturing method of the glass package in any one of. The first glass substrate contains 1% by mass or more of Na ₂ O as a glass composition, and the second glass substrate contains 1% by mass or more of Na ₂ O as a glass composition. The manufacturing method of the glass package in any one of -10.   The sealing material paste contains a sealing material and a vehicle, and the sealing material contains 55 to 95% by volume of bismuth glass and 5 to 45% by volume of a refractory filler. The manufacturing method of the glass package in any one of 1-11.   The method for producing a glass package according to claim 12, wherein the bismuth-based glass contains 0.5% by mass or more of a transition metal oxide as a glass composition. Bismuth-based glass contains Bi ₂ O ₃ 67 to 87%, B ₂ O ₃ 2 to 12%, ZnO 1 to 20%, CuO + Fe ₂ O ₃ 0.5 to 18% by mass% as a glass composition. The manufacturing method of the glass package of Claim 12 characterized by the above-mentioned. Method of manufacturing a glass package of claim 12, the maximum particle diameter D ₉₉ of the refractory filler and less than 5 [mu] m.   The method for producing a glass package according to any one of claims 1 to 15, wherein the glass package is any one of a non-silicon type solar cell, an organic EL device, and a lithium ion secondary battery.