JP2013119501A - Methods for producing glass member added with sealing material layer, and hermetic member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a glass member with a sealing material layer by making it possible to reproducibly suppress generation and the like of cracks of a glass substrate, while forming a sealing material layer in a good state with a laser beam.SOLUTION: After applying a sealant paste in a frame shape onto the surface 1a of a glass substrate 1 having ≤60 ppm compaction value, a laser beam 7 is radiated by scanning along the frame-shaped coated layer 6 of the sealant paste. By heating the frame-shaped coated layer 6 with the laser beam 7, the sealant is baked to form a sealant layer 5.

Description

  The present invention relates to a glass member with a sealing material layer and a method for producing an airtight member.

  In a flat display device (FPD) such as an organic EL display (Organic Electro-Luminescence Display: OELD), a field emission display (Field Emission Display: FED), a plasma display panel (PDP), a liquid crystal display (LCD), etc. A structure in which a display element is sealed with an airtight member (glass package) in which a glass substrate for an element and a glass substrate for sealing are arranged to face each other and the gap between the two glass substrates is sealed is applied ( Patent Document 1). Even in a solar cell such as a dye-sensitized solar cell, application of an airtight member in which a solar cell element (photoelectric conversion element) is sealed with two glass substrates has been studied (see Patent Document 2).

  As a sealing material for sealing between two glass substrates, application of sealing glass excellent in moisture resistance or the like is being promoted. Furthermore, application of laser sealing has been attempted in order to suppress characteristic deterioration of electronic element parts such as OEL elements and dye-sensitized solar cell elements (see Patent Documents 1 and 2). When laser sealing is applied, first, a sealing material is mixed with a vehicle to prepare a sealing material paste, which is applied to the sealing region of one glass substrate, and then the firing temperature of the sealing material ( The sealing glass is melted and baked on a glass substrate to form a sealing material layer. Next, after laminating the glass substrate having the sealing material layer and the other glass substrate via the sealing material layer, the laser material is irradiated from one glass substrate side to heat and melt the sealing material layer. By this, the electronic element part provided between the glass substrates is sealed.

  A heating furnace is generally used for forming the sealing material layer. Patent Document 3 describes that, in the sealing material layer forming step, a first temperature raising process for removing the organic binder and a second temperature raising process for baking the sealing material are performed. In the first temperature raising process, the glass substrate is heated from the back side thereof using a hot plate, an infrared heater, a heating lamp, laser light, or the like. In the second temperature raising process for baking the sealing material, a heating furnace for heating the entire glass substrate is used. In Patent Document 4, a sealing material paste in which a low-melting glass (sealing glass), a binder, and a solvent are mixed is applied to one panel substrate, and then the coating layer of the sealing material paste is baked with laser light. The formation of a sealing material layer is described.

  When local heating by laser light is applied to the formation of the sealing material layer, the glass substrate is likely to crack when the sealing material layer is formed due to the film thickness variation of the coating layer of the sealing material paste. There are difficulties. That is, since the sealing material paste is applied by screen printing or a dispenser, the film thickness of the coating layer is likely to vary. When the coating layer of the sealing material paste having a variation in film thickness is fired by irradiating it with a laser beam, the thick part tends to be heated excessively, and conversely, the thin part tends to be insufficiently fired. . For this reason, if the entire coating layer of the sealing material paste is to be sufficiently baked, the thick portion is locally overheated, and cracks or the like are likely to occur in the glass substrate. Cracks generated in the glass substrate cause a decrease in manufacturing yield and reliability of an airtight member used in FPDs, solar cells, and the like.

JP-T-2006-524419 JP 2008-115057 A JP 2003-068199 A JP 2002-366050 A

  The purpose of the present invention is to reproduce the occurrence of cracks due to local overheating of the glass substrate while forming the sealing material layer well when forming the sealing material layer by applying local heating by laser light. It is providing the manufacturing method of the glass member with a sealing material layer which made it possible to suppress well, and the manufacturing method of an airtight member.

  The method for producing a glass member with a sealing material layer according to the present invention was prepared by preparing a glass substrate having a sealing region, and mixing a sealing material containing a sealing glass and a laser absorber with an organic binder. Applying a sealing material paste in a frame shape on the sealing region of the glass substrate, and irradiating the laser beam while scanning along the frame-shaped coating layer of the sealing material paste, Heating the entire frame-shaped coating layer to remove the organic binder in the frame-shaped coating layer and firing the sealing material to form a sealing material layer, and the glass The substrate is characterized by a compaction value of 60 ppm or less.

  The method for manufacturing an airtight member of the present invention includes a step of preparing a first glass substrate having a first surface provided with a first sealing region, and a second method including a second sealing region. A step of preparing a second glass substrate having a surface; and a sealing material paste prepared by mixing a sealing material containing a sealing glass and a laser absorber with an organic binder. A step of applying a frame shape on the first sealing region, and irradiating the firing laser light along the frame-shaped coating layer of the sealing material paste while irradiating the entire frame-shaped coating layer with the laser light The step of baking the sealing material to form the sealing material layer while removing the organic binder in the frame-shaped coating layer by heating the first surface and the second surface With the first glass substrate and the front through the sealing material layer A step of laminating a second glass substrate, and irradiation with a laser beam for sealing through the first glass substrate or the second glass substrate while scanning along the sealing material layer, and the sealing material layer Forming a sealing layer that hermetically seals a gap between the first glass substrate and the second glass substrate, and the first glass substrate comprises: The compaction value is 60 ppm or less.

  According to the manufacturing method of the glass member with a sealing material layer of the present invention, it is possible to suppress the occurrence of cracks due to local overheating of the glass substrate with good reproducibility while forming the sealing material layer satisfactorily. Therefore, by manufacturing an airtight member using such a glass member with a sealing material layer, it is possible to provide an airtight member excellent in airtight sealing performance and reliability with a high yield.

It is sectional drawing which shows the manufacturing method of the airtight member by embodiment of this invention. It is a top view which shows the 1st glass substrate used with the manufacturing method of the airtight member shown in FIG. It is sectional drawing along the AA line of FIG. It is a top view which shows the 2nd glass substrate used with the manufacturing method of the airtight member shown in FIG. It is sectional drawing which shows the formation process of the sealing material layer to the 1st glass substrate in the manufacturing method of the airtight member shown in FIG. It is a figure which shows the scanning example of the laser beam for baking in the manufacturing method of the airtight member shown in FIG. It is a figure which shows an example of the relationship between the film thickness of the frame-shaped application layer of sealing material paste, and the heating temperature of the frame-shaped application layer at the time of irradiating a laser beam. It is a figure which shows the relationship between the scanning direction of the laser beam for baking, and the propagation direction of the crack after baking. It is a figure which shows the example of the irradiation end position of the laser beam for baking in the formation process of the sealing material layer of embodiment of this invention. It is a figure for demonstrating the completion | finish area | region of the laser beam for baking in the formation process of the sealing material layer of embodiment of this invention. It is a figure for demonstrating the scanning speed of the completion | finish area | region of the laser beam for baking in the formation process of the sealing material layer of embodiment of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. 1 to 6 are views showing a manufacturing process of an airtight member according to an embodiment of the present invention. Here, as an airtight member to which the manufacturing method of the embodiment of the present invention is applied, a glass package, a dye-sensitized solar cell, and a thin-film silicon solar cell for sealing a display element in an FPD such as OELD, FED, PDP, LCD, etc. Examples thereof include a glass package for sealing a solar cell element in a sealed solar cell such as a compound semiconductor solar cell, an airtight package for a reflecting mirror, and a multilayer glass.

First, as shown in FIG. 1A, a first glass substrate 1 and a second glass substrate 2 are prepared. For the first and second glass substrates 1 and 2, for example, glass substrates formed of alkali-free glass or soda lime glass having various known compositions are used. The alkali-free glass has a thermal expansion coefficient of about 30 to 40 × 10 ⁻⁷ / K. Soda lime glass has a thermal expansion coefficient of about 80 to 90 × 10 ⁻⁷ / K. At least one of the first and second glass substrates 1 and 2 may be chemically strengthened glass or the like. A glass substrate having a compaction value of 60 ppm or less is used for the first glass substrate 1 serving as a base material for forming the sealing material layer. The compaction value of the glass substrate and the reason for its definition will be described in detail later.

  As shown in FIGS. 2 and 3, a frame-shaped first sealing region 3 is provided on the surface 1 a of the first glass substrate 1 along the outer peripheral region. As shown in FIG. 4, a frame-shaped second sealing region 4 corresponding to the first sealing region 3 is provided on the surface 2 a of the second glass substrate 2. The 1st and 2nd sealing area | regions 3 and 4 become a formation area of a sealing layer. The first sealing region 3 is a region for forming a sealing material layer. The first glass substrate 1 and the second glass substrate 2 have a predetermined gap so that the surface 1a having the first sealing region 3 and the surface 2a having the second sealing region 4 face each other. Is placed. The space | interval of the 1st glass substrate 1 and the 2nd glass substrate 2 is suitably set according to the use etc. of an airtight member.

  When the hermetic member manufactured in this embodiment is used as a glass package of an electronic device or the like, it corresponds to the electronic device between the surface 1a of the first glass substrate 1 and the surface 2a of the second glass substrate 2. An electronic element part is provided. The electronic element section includes, for example, an OEL element for OELD and OEL illumination, an electron emitting element for FED, a plasma light emitting element for PDP, a liquid crystal display element for LCD, and a solar cell element for solar cell. Is. Various known structures are applied to the electronic element portion, and the structure is not limited thereto. Further, when the hermetic member is used as an airtight package of the reflecting mirror, a metal reflecting film is provided on at least one of the surface 1a of the first glass substrate 1 and the surface 2a of the second glass substrate 2.

  In the sealing region 3 of the first glass substrate 1, a frame-shaped sealing material layer 5 is formed as shown in FIGS. 1 (a), 2 and 3. The sealing material layer 5 is a layer made of a material obtained by baking a sealing material including a sealing glass and a laser absorbing material. The sealing material is obtained by blending a sealing material as a main component with a laser absorbing material and, if necessary, an inorganic filler such as a low expansion filler. The sealing material may contain additives other than these as required.

  For the sealing glass (glass frit), for example, low melting point glass such as bismuth glass, tin-phosphate glass, vanadium glass, and lead glass is used. Among these, bismuth-based glass and tin--in consideration of sealing properties (adhesiveness) to the glass substrates 1 and 2 and their reliability (adhesion reliability and sealing property), influence on the environment and human body, etc. It is preferable to use a low-melting sealing glass made of phosphate glass.

Bismuth-based glass (glass frit) is composed of 70 to 90% by mass of Bi ₂ O ₃ , 1 to 20% by mass of ZnO, and 2 to 12% by mass of B ₂ O ₃ (basically, the total amount is 100% by mass). It is preferable to have a composition of Bi ₂ O ₃ is a component that forms a glass network. When the content of Bi ₂ O ₃ is less than 70% by mass, the softening point of the low-melting glass becomes high and sealing at a low temperature becomes difficult. When the content of Bi ₂ O ₃ exceeds 90% by mass, it becomes difficult to vitrify and the thermal expansion coefficient tends to be too high.

ZnO is a component that lowers the thermal expansion coefficient and the like. Vitrification becomes difficult when the content of ZnO is less than 1% by mass. When the content of ZnO exceeds 20% by mass, stability during low-melting glass molding is lowered, and devitrification is likely to occur. B ₂ O ₃ is a component that increases the range in which vitrification is possible by forming a glass skeleton. If the content of B ₂ O ₃ is less than 2% by mass, vitrification becomes difficult, and if it exceeds 12% by mass, the softening point becomes too high, and even if a load is applied during sealing, sealing is performed at a low temperature. It becomes difficult.

The glass formed of the above three components has a low glass transition point and is suitable for a sealing material for low temperature. Al ₂ O ₃ , CeO ₂ , SiO ₂ , Ag ₂ O, MoO ₃ , Nb ₂ O ₃ , Ta ₂ O ₅ , Ga ₂ O ₃ , Sb ₂ O ₃ , Li ₂ O, Na ₂ O, K ₂ O, Cs ₂ O, CaO, SrO, BaO, WO ₃ , P ₂ O ₅ , SnO _x (X is 1 or 2) etc. may be contained. However, if the content of any component is too large, the glass becomes unstable and devitrification may occur, and the glass transition point and softening point may increase. Therefore, the total content of any component is 30% by mass. The following is preferable. The glass composition in this case is adjusted so that the total amount of the basic component and the optional component is basically 100% by mass.

Tin - phosphate glass (glass frit) is 55 to 68 mol% of SnO, 0.5 to 5 mol% of SnO _2, and 20 to 40 mol% of P ₂ O ₅ (the total amount is basically 100 mol%) is preferable. SnO is a component for lowering the melting point of glass. If the SnO content is less than 55 mol%, the viscosity of the glass will be high and the sealing temperature will be too high, and if it exceeds 68 mol%, it will not vitrify.

SnO ₂ is a component for stabilizing the glass. If the content of SnO ₂ is less than 0.5 mol%, SnO ₂ is separated and precipitated in the glass that has been softened and melted during the sealing operation, the fluidity is impaired and the sealing workability is lowered. If the content of SnO ₂ exceeds 5 mol%, SnO ₂ is likely to precipitate during melting of the low-melting glass. P ₂ O ₅ is a component for forming a glass skeleton. If the content of P ₂ O ₅ is less than 20 mol%, the glass does not vitrify, and if the content exceeds 40 mol%, the weather resistance, which is a disadvantage specific to phosphate glass, may be deteriorated.

The ratio (mol%) of SnO and SnO ₂ in the glass frit can be determined as follows. First, after the glass frit (low melting point glass powder) is acid-decomposed, the total amount of Sn atoms contained in the glass frit is measured by ICP emission spectroscopic analysis. Next, since Sn ²⁺ (SnO) is obtained by acidimetric decomposition, Sn ⁴⁺ (SnO ₂ ) is obtained by subtracting the obtained Sn ²⁺ from the total amount of Sn atoms.

The glass formed of the above three components has a low glass transition point and is suitable for a low-temperature sealing material. However, a component that forms a glass skeleton such as SiO ₂ , ZnO, B ₂ O ₃ , Al _{2 O 3, WO 3, MoO} 3, Nb 2 O 5, TiO 2, ZrO 2, Li 2 O, stabilizing _{Na 2 O, K 2 O,} Cs 2 O, MgO, CaO, SrO, the glass BaO, etc. The component to be made may be contained as an optional component. However, if the content of any component is too large, the glass becomes unstable and devitrification may occur, and the glass transition point and softening point may increase. Therefore, the total content of any component is 30 mol%. The following is preferable. The glass composition in this case is adjusted so that the total amount of the basic component and the optional component is basically 100 mol%.

  The sealing material contains a laser absorber. As the laser absorbing material, a compound such as at least one metal selected from Fe, Cr, Mn, Co, Ni and Cu or an oxide containing the metal is used. Other pigments may be used. The content of the laser absorbing material is preferably in the range of 0.1 to 40% by volume with respect to the sealing material. If the content of the laser absorbing material is less than 0.1% by volume, the sealing material layer 5 may not be sufficiently melted. If the content of the laser absorber exceeds 40% by volume, there is a risk of locally generating heat in the vicinity of the interface with the second glass substrate 2, and the fluidity at the time of melting of the sealing material deteriorates, resulting in the second There exists a possibility that adhesiveness with the glass substrate 2 may fall. Preferably it is 37 volume% or less.

Furthermore, the sealing material may contain a low expansion filler in the range of 0 to 50% by volume as required. The low expansion filler is selected from silica, alumina, zirconia, zirconium silicate, aluminum titanate, mullite, cordierite, eucryptite, spodumene, zirconium phosphate compounds, quartz solid solution, soda lime glass and borosilicate glass. It is preferable to use at least one kind. Zirconium phosphate compounds include (ZrO) ₂ P ₂ O ₇ , NaZr ₂ (PO ₄ ) ₃ , KZr ₂ (PO ₄ ) ₃ , Ca _0.5 Zr ₂ (PO ₄ ) ₃ , NbZr (PO ₄ ) ₃ , Zr ₂ (WO ₃ ) (PO ₄ ) ₂ , and complex compounds thereof can be mentioned. The low expansion filler has a lower thermal expansion coefficient than the sealing glass.

  The content of the low expansion filler is preferably set so that the thermal expansion coefficient of the sealing glass approaches the thermal expansion coefficient of the glass substrates 1 and 2. Although it depends on the thermal expansion coefficient of the sealing glass or the glass substrates 1 and 2, the low expansion filler is preferably contained in the range of 0.1 to 50% by volume with respect to the sealing material. The content of the low expansion filler can be appropriately changed depending on the thickness of the sealing material layer 5 and the like. However, if the content of the low expansion filler exceeds 50% by volume, the fluidity at the time of melting of the sealing material may be deteriorated and the adhesiveness with the first glass substrate 1 may be lowered. Preferably it is 45 volume% or less. Since the content of the low expansion filler affects the total content with the laser absorber, the total content is preferably in the range of 0.1 to 50% by volume.

  The sealing material layer 5 is formed as follows. The formation process of the sealing material layer 5 is demonstrated with reference to FIG. FIG. 5 shows an embodiment of the method for producing a glass member with a sealing material layer of the present invention. First, a sealing material is prepared by blending a sealing glass with a laser absorbing material or a low expansion filler, and this is mixed with a vehicle to prepare a sealing material paste.

  The vehicle is obtained by dissolving a resin as a binder component in a solvent. Examples of the resin for the vehicle include cellulose resins such as methyl cellulose, ethyl cellulose, carboxymethyl cellulose, oxyethyl cellulose, benzyl cellulose, propyl cellulose, nitrocellulose, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, butyl acrylate, An organic resin such as an acrylic resin obtained by polymerizing one or more acrylic monomers such as 2-hydroxyethyl acrylate is used. Solvents include organic solvents such as terpineol, butyl carbitol acetate, and ethyl carbitol acetate in the case of cellulosic resins, and organic solvents such as methyl ethyl ketone, terpineol, butyl carbitol acetate, and ethyl carbitol acetate in the case of acrylic resins. Is used.

  The resin component in the vehicle functions as a binder for the sealing material and needs to be removed before firing the sealing material. The viscosity of the sealing material paste may be adjusted to the viscosity corresponding to the apparatus applied to the glass substrate 1, and is adjusted by the ratio of the resin component (organic binder) and the solvent (organic solvent, etc.) and the ratio of the sealing material and the vehicle. can do. A known additive may be added to the sealing material paste as a glass paste such as an antifoaming agent or a dispersing agent. In preparing the sealing material paste, a known method using a rotary mixer equipped with a stirring blade, a roll mill, a ball mill, or the like can be applied.

  As shown in FIG. 5A, a sealing material paste is applied to the sealing region 3 of the first glass substrate 1 and dried to form an application layer 6. The sealing material paste is applied onto the first sealing region 3 by applying a printing method such as screen printing or gravure printing, or is applied along the first sealing region 3 using a dispenser or the like. To do. The coating layer 6 is preferably dried at a temperature of 120 ° C. or more for 10 minutes or more, for example. The drying process is performed to remove the solvent in the coating layer 6. If the solvent remains in the coating layer 6, the organic binder may not be sufficiently removed in the subsequent baking step (laser baking step).

  Next, as shown in FIG. 5B, the coating layer (dry film) 6 of the sealing material paste is irradiated with a laser beam 7 for firing. By irradiating the laser beam 7 for firing along the coating layer 6 and selectively heating, the sealing material is baked to form the sealing material layer 5 while removing the organic binder in the coating layer 6. (FIG. 5C). The laser beam 7 for firing is not particularly limited, and laser light from a semiconductor laser, a carbon dioxide gas laser, an excimer laser, a YAG laser, a HeNe laser, or the like is used. The same applies to sealing laser light described later.

  The firing process of the coating layer 6 by the laser beam 7 is not necessarily limited to the film thickness of the coating layer 6, but the thickness after firing (the thickness of the sealing material layer 5) is 15 μm or less. This is particularly effective for the coating layer 6 having a film thickness. When the thickness after baking exceeds 15 μm, there is a possibility that the entire coating layer 6 cannot be uniformly heated by the laser light 7. However, if the coating layer 6 has a film thickness of 150 μm or less after baking by adjusting the formation conditions of the coating layer 6, the irradiation conditions of the laser beam 7, and the like, the laser beam 7 can be fired. There is. Practically, the thickness of the sealing material layer 5 is preferably 1 μm or more.

  When forming the sealing material layer 5 with the laser beam 7 for firing, first, as shown in FIG. 6, the laser beam 7 is irradiated to the irradiation start position S of the frame-shaped coating layer 6 of the sealing material paste. Subsequently, the laser beam 7 is irradiated while scanning along the frame-shaped coating layer 6. Then, the laser beam 7 is scanned to the irradiation end position F at least partially overlapping with the irradiation start position S, the whole frame-shaped coating layer 6 is heated, and then the irradiation of the laser beam 7 is ended. When irradiating the laser beam 7 while scanning along the frame-shaped coating layer 6, the heating temperature of the frame-shaped coating layer 6 is (T + 80 ° C.) or more (T + 550 ° C.) with respect to the softening temperature T (° C.) of the sealing glass. ) The following range is preferable. The softening temperature T of the sealing glass indicates a temperature at which it softens and flows but does not crystallize. The temperature of the frame-shaped coating layer 6 when irradiated with the laser light 7 is a value measured with a radiation thermometer.

  When the laser beam 7 is irradiated so that the temperature of the frame-shaped coating layer 6 is in the range of (T + 80 ° C.) to (T + 550 ° C.), the sealing glass in the sealing material is melted and rapidly cooled and solidified. The sealing material is baked onto the first glass substrate 1 to form the sealing material layer 5. Under the irradiation condition of the laser beam 7 such that the temperature of the frame-shaped coating layer 6 does not reach (T + 80 ° C.), only the surface portion of the frame-shaped coating layer 6 is melted and the entire frame-shaped coating layer 6 cannot be melted uniformly. There is a fear. Under the irradiation conditions of the laser beam 7 such that the temperature of the frame-shaped coating layer 6 exceeds (T + 550 ° C.), cracks and cracks are likely to occur in the glass substrate 1 and the sealing material layer (fired layer) 7.

  The organic binder in the frame-shaped coating layer 6 is thermally decomposed by irradiating the laser beam 7 while scanning so that the heating temperature of the frame-shaped coating layer (dry film) 6 of the sealing material paste falls within the above range. Removed. Since the laser beam 7 is irradiated while scanning along the frame-shaped coating layer 6, the portion located in front of the traveling direction of the laser beam 7 is preheated appropriately. The thermal decomposition of the organic binder proceeds not only when the laser beam 7 is directly applied to the corresponding part of the frame-shaped coating layer 6 but also by a preheated part ahead of the traveling direction of the laser light 7. By these, the organic binder in the frame-shaped coating layer 6 can be effectively and efficiently removed. Specifically, the amount of residual carbon in the sealing material layer 5 can be reduced. Residual carbon becomes a factor which raises the impurity gas concentration in an airtight member (glass package).

  The laser beam 7 is preferably irradiated while scanning along the frame-shaped coating layer 6 at a scanning speed in the range of 3 to 20 mm / second. When the scanning speed of the laser beam 7 when scanning along the frame-shaped coating layer 6 is less than 3 mm / second, the baking time of the frame-shaped coating layer 6 by the laser beam 7 increases, and the sealing material layer 5 is made efficient. It cannot be formed well. On the other hand, when the scanning speed of the laser beam 7 exceeds 20 mm / second, only the surface portion may be melted and vitrified before the entire frame-shaped coating layer 6 is uniformly heated. The release of gas generated by decomposition to the outside is reduced. For this reason, bubbles are easily generated inside the sealing material layer 5, and deformation due to the bubbles is likely to occur on the surface. Furthermore, the amount of residual carbon in the sealing material layer 5 tends to increase. If the sealing material layer 5 having a poor organic binder removal state is used to seal between the glass substrates 1 and 2, the adhesive strength between the glass substrates 1 and 2 and the sealing layer is reduced, or the airtightness of the glass package is reduced. May decrease.

Further, when the heating temperature of the frame-shaped coating layer 6 is set to the range of (T + 80 ° C.) to (T + 550 ° C.) with the laser beam 7 having a scanning speed of 3 to 20 mm / second, the laser beam 7 is 100 to It preferably has a power density in the range of 1100 W / cm ² . If the output density of the laser beam 7 is less than 100 W / cm ² , the entire frame-shaped coating layer 6 may not be heated uniformly. When the output density of the laser beam 7 exceeds 1100 W / cm ² , the glass substrate 1 is excessively heated, and cracks and cracks are likely to occur.

  Although FIG. 5 shows a state in which the laser beam 7 is irradiated from above the frame-shaped coating layer 6, the laser beam 7 may be irradiated to the frame-shaped coating layer 6 through the glass substrate 1. For example, in order to shorten the baking time of the frame-shaped coating layer 6, it is effective to increase the output of the laser beam 7 and increase the scanning speed. For example, when the high-power laser beam 7 is irradiated from above the frame-shaped coating layer 6, only the surface portion of the frame-shaped coating layer 6 may be vitrified. Vitrification of only the surface portion of the frame-shaped coating layer 6 causes various problems as described above. For such a point, when the frame-shaped coating layer 6 is irradiated with the laser beam 7 from the glass substrate 1 side, the gas generated by the thermal decomposition of the organic binder even if the portion irradiated with the laser beam 7 is vitrified. Can be released from the surface of the frame-shaped coating layer 6. It is also effective to irradiate the laser beam 7 from the upper and lower surfaces of the frame-shaped coating layer 6.

  The beam shape of the laser beam 7 (irradiation spot shape) is not particularly limited. The beam shape of the laser beam 7 is generally circular, but is not limited to circular. The beam shape of the laser light 7 may be an ellipse having a minor axis in the width direction of the coating layer 6. According to the laser beam 7 whose beam shape is shaped into an ellipse, the irradiation area of the laser beam 7 on the frame-shaped coating layer 6 can be enlarged, and the scanning speed of the laser beam 7 can be increased. By these, it becomes possible to shorten the baking time of the frame-shaped coating layer 6.

  In the step of forming the sealing material layer 5 according to this embodiment, the frame-shaped coating layer 6 of the sealing material paste is selectively heated by irradiating the laser beam 7 for firing. Therefore, even when an organic resin film such as a color filter or an element film is formed on the surface 1a of the first glass substrate 1, thermal damage is not caused to the organic resin film or the element film. The sealing material layer 5 can be formed satisfactorily. Furthermore, since it is excellent also in the removability of an organic binder, the sealing material layer 5 excellent in sealing property, reliability, etc. can be obtained.

  Of course, the process of forming the sealing material layer 5 by the laser beam 7 for firing is applicable even when an organic resin film, an element film, or the like is not formed on the surface 1a of the first glass substrate 1, Even in such a case, the sealing material layer 5 excellent in sealing property, reliability, etc. can be obtained. Furthermore, the firing process using the laser light 7 consumes less energy than the firing process using the conventional heating furnace, and contributes to the reduction of manufacturing steps and manufacturing costs. Therefore, the process of forming the sealing material layer 5 using the laser light 7 is also effective from the viewpoint of energy saving and cost reduction.

  By the way, in forming the sealing material layer 5 by irradiating the frame-shaped coating layer 6 of the sealing material paste with the laser beam 7, the frame-shaped coating layer 6 can be formed even if the coating condition of the sealing material paste is adjusted. However, it is inevitable that the film thickness varies to some extent. For example, when the sealing material paste is applied with a dispenser so as to have a film thickness as described above, the film thickness of the paste coating film varies by about ± 2 to 5 μm. Since the shrinkage rate when the paste coating film is dried is about 60 to 70%, the frame-shaped coating layer 6 after drying has a film thickness variation of about ± 1.3 to 4 μm. The locally thick portion of the frame-shaped coating layer 6 has a larger amount of the laser absorbing material than the thin portion, so that the temperature rise when the laser light 7 under the same conditions is irradiated becomes large.

  FIG. 7 shows an example of the relationship between the film thickness of the frame-shaped coating layer 6 and the heating temperature of the frame-shaped coating layer 6 when the laser beam 7 is irradiated. FIG. 7 shows a coating layer obtained by irradiating a coating layer (dried film) obtained by applying a sealing material paste in a line shape having a line width of 500 μm with a laser beam having an output of 15 W at a scanning speed of 5 mm / second. The relationship between the film thickness and the heating temperature is shown. As shown in FIG. 7, when the coating layer thickness is 4 μm, the heating temperature is about 700 ° C., whereas when the coating layer thickness is 9 μm, the heating temperature rises to around 800 ° C. Thus, the heating temperature varies greatly depending on the film thickness of the frame-shaped coating layer 6. That is, if the film thickness of the frame-shaped coating layer 6 varies, a difference occurs in the partial heating temperature when the laser beam 7 is irradiated.

  When irradiating the laser beam 7 to the frame-shaped coating layer 6 where the film thickness varies, if the irradiation conditions of the laser beam 7 are set with reference to the thick part, the thin part is sufficiently fired. However, only the surface portion is melted. Such a part causes a bonding failure or the like in the laser sealing process. If the irradiation condition of the laser beam 7 is set on the basis of the thin part, the thick part is heated excessively. When the frame-shaped coating layer 6 is locally heated excessively, cracks are likely to occur in the glass substrate 1 in the vicinity thereof. When irradiating the laser beam 7 along the frame-shaped coating layer 6, since it is a rapid heating / cooling process locally, the stress generated by the glass substrate 1 being pulled by the fired portion of the frame-shaped coating layer 6 during the rapid cooling. In addition, cracks are likely to occur in the glass substrate 1 due to stress generated by the rapid cooling of the glass substrate 1 itself. As shown in FIG. 8, the crack C occurs in the direction perpendicular to the scanning direction X of the laser light 7. In addition, when a crack arises in the glass substrate 1, the similar crack C also arises in the sealing material layer 5.

  In forming the sealing material layer 5 by irradiating the frame-shaped coating layer 6 having the above-described film thickness variation with the laser beam 7, it is effective to use the glass substrate 1 having a compaction value of 60 ppm or less. The compaction (heat shrinkage rate) is a glass heat shrinkage rate generated by relaxation of the glass structure during the heat treatment. The compaction value C in the present invention is the shrinkage rate (ppm) of the distance between the indentations when the glass substrate is heated to 550 ° C. and cooled to room temperature after two indentations are made on the surface of the glass substrate at a predetermined interval. That means.

The compaction value C in the present invention means a value measured by the following method. First, two indentations are made on the surface of the glass substrate at 90 mm intervals (A) in the long side direction. Next, the glass plate is heated to 550 ° C. at a temperature increase rate of 100 ° C./hour, held at 550 ° C. for 1 hour, and then cooled to room temperature at a temperature decrease rate of 100 ° C./hour. After cooling, the distance (B) between the indentations is measured again. The compaction value C is calculated from the distances A and B between the indentations using the following formula (1). The indentation distances A and B are measured using an optical microscope.
C [ppm] = (A−B) / A × 10 ⁶ (1)

  When the compaction value C is small, it means that the glass substrate 1 is sufficiently cooled, and a state where the volume expanded when heated to a high temperature is reduced to near the original volume and then solidified. It has become. On the other hand, the fact that the compaction value C is large means that the expanded volume is solidified before it is sufficiently contracted when heated to a high temperature, that is, a state where the large volume remains solid. Since the baking process of the frame-shaped coating layer 6 using the laser beam 7 is a local rapid heating / cooling process, the sealing material layer 5 and the vicinity of the glass substrate 1 are in a high compaction state after the baking process using the laser beam 7. It becomes.

  In such a firing process using the laser beam 7, the glass substrate 1 having a small original compaction value C may extend following the sealing material layer 5 that is in a high compaction state when rapidly cooled after the irradiation of the laser beam 7. it can. Further, when the glass substrate 1 itself is rapidly cooled, the original compaction value C is small, so that the glass substrate 1 can be locally extended to cope with a high compaction state caused by the irradiation of the laser beam 7. By these, the stress added to the glass substrate 1 by local overheating of the frame-shaped coating layer 6 can be relieved. Therefore, cracks generated in the glass substrate 1 can be suppressed when the sealing material layer 5 is formed by irradiating the frame-shaped coating layer 6 having a variation in film thickness with the laser beam 7.

  The compaction of the first glass substrate 1 serving as a base material for forming the sealing material layer 5 in order to relieve the stress generated during the rapid cooling after the irradiation of the laser beam 7 and suppress the cracks generated in the glass substrate 1. The value is 60 ppm or less. If the compaction value of the glass substrate 1 exceeds 60 ppm, the stress relaxation effect becomes insufficient, and the generation of cracks due to the film thickness variation of the frame-shaped coating layer 6 cannot be sufficiently suppressed. The compaction value of the first glass substrate 1 is more preferably 55 ppm or less. The lower limit value of the compaction value of the first glass substrate 1 is not particularly limited and is ideally zero. However, in consideration of a practical slow cooling process of the first glass substrate 1, the compaction value of the glass substrate 1 is generally 10 ppm or more.

  Furthermore, the first glass substrate 1 preferably has a strain point of 600 ° C. or higher. As a result, the stress generated in the first glass substrate 1 along with the irradiation process of the laser light 7 can be reduced. The strain point of the first glass substrate 1 is more preferably 640 ° C. or higher. However, in order to increase the strain point of the first glass substrate 1, an increase in manufacturing cost based on the slow cooling step or the like is caused, and therefore the strain point of the first glass substrate 1 is practically 780 ° C. or lower. It is preferable that it is 725 degreeC or less. The glass substrate 1 having a compaction value of 60 ppm or less and a strain point of 600 ° C. or more can be obtained, for example, by controlling a glass substrate manufacturing process or a slow cooling process performed separately. Although the slow cooling process of the glass substrate 1 is based on the material etc., after heating to the temperature of 550 degreeC or more and hold | maintaining for a predetermined time, it is preferable to cool with the temperature-fall rate of 100 degrees C / min or less. The plate thickness of the glass substrate 1 is desirably 0.7 mm or less.

  As described above, by using the glass substrate 1 having a compaction value of 60 ppm or less, the step of firing the frame-shaped coating layer 6 with the laser beam 7 due to the locally thick portion of the frame-shaped coating layer 6. Thus, cracks generated in the glass substrate 1 can be suppressed. In other words, even when the frame-shaped coating layer 6 is irradiated with the laser beam 7 under a condition that the thin part can be sufficiently baked, the glass substrate 1 is cracked due to the thick part. Can be suppressed. Therefore, it becomes possible to widen the margin of the heating temperature in the baking process of the frame-shaped coating layer 6 by the laser light 7. That is, the width from the lower limit of the heating temperature of the frame-shaped coating layer 6 in the firing step (the lowest temperature at which the unfired portion does not occur in the sealing material layer 5) to the upper limit (the highest temperature at which no crack occurs in the glass substrate 1). Can be spread.

  By widening the temperature margin in the step of firing the frame-shaped coating layer 6 with the laser light 7, the entire frame-shaped coating layer 6 can be fired satisfactorily while suppressing cracks in the glass substrate 1. The temperature margin during firing with the laser beam 7 is preferably 70 ° C. or higher. By expanding the temperature margin, it becomes possible to improve the stability and reliability of the baking process of the frame-shaped coating layer 6 by the laser light 7. That is, by using the sealing material layer 5 produced by applying the production process of the embodiment, while suppressing the production yield and reliability of the airtight member due to cracks in the glass substrate 1, It is possible to provide an airtight member having excellent reliability with high reproducibility. However, if the film thickness variation of the frame-shaped coating layer 6 is too large, there is a possibility that a temperature margin commensurate with it cannot be obtained. Therefore, the variation width of the film thickness is preferably 4 μm or less.

  In addition, as described above, when the laser beam 7 is irradiated while scanning along the frame-shaped coating layer 6 of the sealing material paste, the laser in the frame-shaped coating layer 6 is used to heat the entire frame-shaped coating layer 6. It is necessary to set the irradiation start position S and the irradiation end position F of the light 7 so as to overlap at least partially. While scanning the laser beam 7, the irradiation start position S where the melting of the sealing glass is finished is cooled and solidified. For this reason, when the laser beam 7 reaches the irradiation end position F at least partially overlapping with the irradiation start position S, the sealing glass may shrink due to surface tension, void reduction, or the like, and a gap may be generated. If the gap generated in the sealing material layer 5 is wide, the hermetic sealing property of the glass package may be lowered in the subsequent laser sealing step.

  That is, it is considered that the surface tension is superior to the fluidity of the sealing glass heated and melted by the laser beam 7, so that the sealing glass contracts at the irradiation end position F to generate a gap. For such a point, it is effective to maintain the flow state of the sealing glass at the end of irradiation with the laser beam 7. The molten state of the sealing glass when the laser beam 7 reaches the irradiation end position F is maintained, and the time in which the molten sealing glass is in contact with the solidified sealing glass is lengthened. By causing the glass to flow on the sealing glass solidifying the glass, it is possible to suppress the occurrence of a gap due to the surface tension of the sealing glass.

  Specifically, the irradiation end position F of the laser beam 7 in the frame-shaped coating layer 6 is set at least at least one of the already baked portion of the frame-shaped coating layer 6 (the portion that has been irradiated with the laser beam 7 and has been melted and solidified). When the part is set at the overlapping position, the scanning speed of the laser beam 7 in the end region from the position close to the irradiation end position F to the irradiation end position F is set in the scanning region along the frame-shaped coating layer 6 excluding the end region. It is preferable to decelerate from the scanning speed of the laser beam 7. By reducing the scanning speed of the laser beam 7 in the end region, the molten sealing glass is caused to flow toward the already solidified sealing glass, and the molten sealing glass is solidified. It is possible to make sufficient contact. Therefore, the gap width produced by shrinkage due to insufficient fluidity of the sealing glass at the irradiation end position F can be reduced.

  As shown in FIG. 9A, the irradiation end position F of the firing laser beam 7 in the frame-shaped coating layer 6 corresponds to the already baked portion of the frame-shaped coating layer 6 (basically the irradiation start position S). To a position where at least a part overlaps. Thereby, the sealing glass can be integrated in a fluid state. The irradiation end position F of the laser beam 7 is preferably set to a position where the overlap amount (area ratio) with the irradiation start position S is 50% or more as shown in FIG. The irradiation end position F of the laser beam 7 is set at a position overlapping the irradiation start position S as shown in FIG. 9C, or further at a position beyond the irradiation start position S as shown in FIG. 9D. It is more preferable to set. The molten sealing glass in the end region can be brought into better contact with the fired portion of the frame-shaped coating layer 6 (solidified sealing glass).

As shown in FIG. 9D, when the irradiation end position F of the firing laser beam 7 is set to a position beyond the irradiation start position S, the length of the region where the laser beam 7 is irradiated repeatedly is particularly large. It is not limited. However, even if the overlapping irradiation region of the laser beam 7 is made too long, not only can the contact improvement between the molten sealing glass and the solid sealing glass be improved, but also the sealing material. The formation time of the layer 5 is extended correspondingly, and the formation efficiency is lowered. For this reason, the overlapping irradiation region of the laser beam 7 is preferably set to a distance not more than 20 times the beam diameter D of the laser beam 7 from the center of the irradiation start position S with reference to the beam center of the laser beam 7. More preferably, the distance is 5 times or less the beam diameter D. The beam shape of the laser beam 7 is defined by a region where the intensity is 1 / e ² of the maximum beam intensity.

  As shown in FIG. 10A, the position at which the speed of the laser beam 7 is decelerated (the start position of the end region) is the firing portion (firing end) of the frame-shaped coating layer 6 with the beam center of the laser beam 7 as a reference. To a position at least 1.2 times before the beam diameter D of the laser beam 7. When the laser beam 7 is decelerated from a position less than 1.2 times the beam diameter D, the contact time between the molten sealing glass and the solid sealing glass in the end region may be insufficient. is there. The deceleration start position of the laser beam 7 may be a position at least 1.2 times the beam diameter D of the laser beam 7 from the firing end of the frame-shaped coating layer 6, and from a position 1.2 times the beam diameter D. Furthermore, you may decelerate from the near position (position farther from the firing end).

  However, when decelerating from a position that is too far from the firing end of the frame-shaped coating layer 6, the scanning time of the laser light 7 in the state of being decelerated by that amount increases, and the formation time of the sealing material layer 5 is that much. The formation efficiency is lowered. For this reason, the deceleration start position of the laser beam 7 is, as shown in FIG. 10B, the beam diameter D of the laser beam 7 before the firing end of the frame-shaped coating layer 6 with the beam center of the laser beam 7 as a reference. It is preferable to set the position 20 times or less. Thus, it is preferable to set the deceleration start position of the laser beam 7 within a range of 1.2 times or more and 20 times or less of the beam diameter D of the laser beam 7 before the firing end of the frame-shaped coating layer 6. It is more preferable to set within a range of 1.2 times to 5 times the beam diameter D.

  The scanning speed of the laser beam 7 (scanning speed of the laser beam 7 in the scanning region) when scanning along the frame-shaped coating layer 6 is preferably in the range of 3 to 20 mm / second as described above. It is preferable to reduce the scanning speed of the laser beam 7 to 2 mm / second or less in the end region with respect to the scanning speed of the laser beam 7 in such a scanning region. Thereby, the molten sealing glass in the end region can be brought into good contact with the fired portion of the frame-shaped coating layer 6 (solidified sealing glass). More preferably, the scanning speed of the laser beam 7 in the end region is reduced to 0.5 mm / second or less. The lower limit value of the scanning speed of the laser beam 7 in the end region is not particularly limited, but is 0.1 mm / second or more (beam diameter D) in consideration of excessive heating of the glass substrate 2 and a decrease in the formation efficiency of the sealing material layer 5. It is preferable that the position reference is 1.2 times before.

  As shown in FIGS. 11A and 11B, the scanning speed of the laser beam 7 in the end region is from the firing portion (firing end) of the frame-shaped coating layer 6 with the beam center of the laser beam 7 as a reference. It is preferably 2 mm / second or less at a position 1.2 times before the beam diameter D of the laser beam 7. Since the deceleration start position of the laser beam 7 may be a position 1.2 times or more the beam diameter D of the laser beam 7 from the firing end of the frame-shaped coating layer 6 as described above, FIG. As shown, a position (position farther from the firing end) than the position 1.2 times before the beam diameter D of the laser beam 7, that is, 1.2 times or more and 20 times the beam diameter D of the laser beam 7. The laser beam 7 may be scanned at a speed of 2 mm / second or less from a position within the following range.

  FIG. 11B and FIG. 11C show a state in which the laser beam 7 in the end region is scanned at a constant speed that is decelerated from the scanning speed of the scanning region, for example, a constant speed of 2 mm / second or less. As shown in FIG. 11D, the laser beam 7 is irradiated at a predetermined deceleration from the deceleration start position of the laser beam 7 (within a range of 1.2 to 20 times the beam diameter D) to the irradiation end position F. The scanning speed may be reduced. Also in this case, the scanning speed when the beam center of the laser beam 7 reaches a position 1.2 times before the beam diameter D of the laser beam 7 from the firing end of the frame-shaped coating layer 6 is set to 2 mm / second or less. It is preferable. In any case, it is preferable to set the scanning speed of the laser beam 7 at a position 1.2 times before the beam diameter D of the laser beam 7 to 2 mm / second or less, and thereby the gap width generated at the irradiation end position F. Can be narrowed with good reproducibility.

  When the scanning speed of the laser beam 7 in the end region is decelerated from the scan region, if the output density of the laser beam 7 in the end region is the same as that in the scan region, the heating temperature of the frame-shaped coating layer 6 becomes too high. There is a fear. In such a case, it is preferable to lower the output density of the laser light 7 in the end region than in the scanning region. As a result, excessive heating of the frame-shaped coating layer 6, cracks, cracks, and the like of the glass substrate 2 and the sealing material layer (firing layer) 5 can be suppressed. However, if the heating temperature of the frame-shaped coating layer 6 in the end region is within the above range, the laser beam 7 may be irradiated under the same conditions as in the scanning region.

The gap generated at the irradiation end position F of the firing laser beam 7 can be suppressed by reducing the scanning speed of the laser beam 7 in the end region from that in the scanning region. Furthermore, the gap width at the irradiation end position F is also affected by the ease of flow of the sealing material. The flow state of the sealing material is affected by the content and particle size of the laser absorbing material and low expansion filler added to the sealing glass. Therefore, the fluidity-inhibiting factor of the sealing material represented by the sum of the products of the content (mass%) of the laser absorbing material and the low expansion filler and the specific surface area (m ² / g) should be 300 or less. Is more preferable, and 250 or less is more preferable. Thereby, since the fluidity of the sealing material is improved, the gap width can be further narrowed.

  An airtight member is produced using the first glass substrate 1 and the second glass substrate 2 having the sealing material layer 5 formed by the laser baking process described above (FIGS. 1B to 1D). . That is, as shown in FIG. 1B, the first glass substrate 1 and the second glass substrate 2 are laminated via the sealing material layer 5 so that the surfaces 1a and 2a face each other. Thereafter, as shown in FIG. 1C, the sealing material layer 5 is irradiated with the sealing laser beam 8 through the first glass substrate 1. The sealing material layer 5 may be irradiated with the laser light 8 through the second glass substrate 2. As shown in FIG. 1 (d), the sealing laser beam 8 is irradiated while scanning along the frame-shaped sealing material layer 5, and the sealing material layer 5 is sequentially melted and rapidly cooled and solidified. An airtight member 10 is produced by forming a sealing layer 9 that hermetically seals the gap between the glass substrate 1 and the second glass substrate 2. A space 11 between the first glass substrate 1 and the second glass substrate 2 is hermetically sealed by a sealing layer 9.

  Next, the specific conditions of the formation process of the sealing layer 9 by the sealing laser beam 8 will be described. The heating temperature when the sealing material layer 5 is irradiated with the sealing laser beam 8 may be in the range of (T + 80 ° C.) to (T + 550 ° C.) with respect to the softening temperature T (° C.) of the sealing glass. preferable. Under the irradiation condition of the laser light 8 that does not reach the temperature of the sealing material layer 5 (T + 80 ° C.), the adhesion between the glass substrates 1 and 2 and the sealing glass may be insufficient. On the other hand, under the irradiation condition of the laser light 8 such that the temperature of the sealing material layer 5 exceeds (T + 550 ° C.), the glass substrates 1 and 2 and the sealing layer 9 are likely to be cracked or broken.

The laser beam 8 is preferably irradiated while scanning along the sealing material layer 5 at a scanning speed in the range of 3 to 15 mm / second. The output density of the laser beam 8 is preferably in the range of 700 to 5200 W / cm ² . The irradiation end position of the laser beam 8 is preferably set at a position overlapping the irradiation start position or a position exceeding the irradiation start position. In particular, by setting the irradiation end position of the laser light 8 to a position beyond the irradiation start position, it is possible to disperse the stress caused by the irradiation start / end positions of the laser light 8. The overlapping irradiation region of the laser beam 8 is preferably set to a distance not more than 20 times the beam diameter D of the laser beam 8 from the center of the irradiation start position with the beam center of the laser beam 8 as a reference. More preferably, the distance is 5 times or less.

  Similar to the first glass substrate 1, the second glass substrate 2 preferably has a small compaction value. However, since the stress generated in the forming process (sealing process) of the sealing layer 9 by the sealing laser beam 8 is smaller than that in the forming process of the sealing material layer 5 by the firing laser beam 7, the second glass substrate 2 can suppress the occurrence of cracks and the like even when the compaction value is larger than that of the first glass substrate 1. For this reason, it is preferable that the compaction value of the 2nd glass substrate 2 is 170 ppm or less. As for the compaction value of the 2nd glass substrate 2, it is more preferable that it is 150 ppm or less, More preferably, it is 60 ppm or less.

  Next, specific examples of the present invention and evaluation results thereof will be described. In addition, the following description does not limit this invention, The modification | change in the form along the meaning of this invention is possible.

(Examples 1-6, Comparative Examples 1-10)
A glass substrate (size: 90 × 90 mm) having a glass transition point, a compaction value, a strain point and the like shown in Table 1 was prepared. Each glass substrate consists of aluminosilicate glass which does not contain an alkali component, and thickness is as having shown to Tables 1-3. A sealing material paste was applied on a glass substrate by a screen printing method. For the screen printing, a calendar type screen plate having a mesh size of 400 and an emulsion thickness of 5 μm was used. The sealing material paste was applied by screen printing so that 22 lines having a line width of 0.65 mm and a length of 30 mm were formed, and then dried under conditions of 120 ° C. × 10 minutes. The average film thickness of the coating layer (dry film) of the sealing material paste was 7 μm, and the variation width of the film thickness was 0.5 μm.

As the sealing material paste, one prepared as follows was used. First, a bismuth glass frit having a composition of 83% by mass of Bi ₂ O _3, 5% by mass of B ₂ O ₃ , 11% by mass of ZnO and 1% by mass of Al ₂ O ₃ and having an average particle diameter of 1 μm (softening temperature: 410 C.), cordierite powder having an average particle size of 0.9 μm and a specific surface area of 12.4 m ² / g as a low expansion filler, Fe ₂ O ₃ —Al ₂ O ₃ —MnO—CuO composition, A laser absorber having an average particle diameter of 0.8 μm and a specific surface area of 8.3 m ² / g was prepared.

Bismuth glass frit 66.9% by volume (79.8% by mass), cordierite powder 19.2% by volume (8.8% by mass), and laser absorber 13.9% by volume (11.4% by mass) To prepare a sealing material. A sealing material paste was prepared by mixing 80% by mass of the sealing material with 20% by mass of the vehicle. The vehicle is obtained by dissolving ethyl cellulose (2.5% by mass) as a binder component in a solvent (97.5% by mass) made of terpineol. The sum of the products of the cordierite and laser absorber content (mass%) and the specific surface area (m ² / g) (the fluidity-inhibiting factor of the sealing material) is 203.7.

  Next, the glass substrate on which the coating layer of the sealing material paste was formed was disposed on the sample holder of the laser irradiation apparatus via an alumina substrate having a thickness of 0.5 mm. The coating layer of the sealing material paste on the glass substrate was irradiated with a circular laser beam having a wavelength of 940 nm and a beam shape of 1.6 mm in diameter. The scanning speed of the laser beam was 5 mm / second. The output of the laser beam was changed in increments of 0.5 W between 10 and 15 W, and the coating layer of one line was baked with one output, and the heating temperature of the coating layer at that time was measured with a radiation thermometer. From the sealing material layer thus formed and the heating temperature at the time of forming the sealing material layer, the temperature margin of the heating temperature in the firing process of the sealing material paste coating layer by laser light was determined as follows.

  The sealing material layer was observed with a metallurgical microscope, and those with bubbles remaining on the surface were judged to be insufficiently fired. Among the heating temperatures (measurement temperatures) of the sealing material layer insufficiently fired, the highest temperature was set as the lower limit value of the heating temperature of the coating layer. Next, the presence or absence of cracks in the glass substrate was observed with a metallographic microscope. Since cracks are difficult to observe in the state having the sealing material layer, the glass substrate was immersed in a 30% nitric acid aqueous solution for 10 minutes to remove the sealing material layer. After washing with water and drying, the surface of the glass substrate was observed with a metal microscope to determine the presence or absence of cracks. Of the heating temperature (measurement temperature) of the sealing material layer in the glass substrate in which the crack was generated, the lowest temperature was defined as the upper limit value of the heating temperature of the coating layer. The difference between the lower limit value and the upper limit value of the heating temperature was defined as the temperature margin of the heating temperature in the coating layer firing step. The results are shown in Table 1, Table 2 and Table 3.

  As is apparent from Tables 1, 2 and 3, by using a glass substrate having a compaction value of 60 ppm or less, the temperature margin of the heating temperature in the firing process of the coating layer by laser light can be expanded. Therefore, even when there is variation in the thickness of the coating layer of the sealing material paste, the entire coating layer can be baked satisfactorily without causing cracks in the glass substrate during laser light irradiation. It becomes.

  Next, using the glass substrates of Examples 1 to 6 and Comparative Examples 1 to 8 as the first and second glass substrates, respectively, airtight members were produced as follows. First, in the sealing region of the first glass substrate (dimensions: 90 × 90 mm) made of the glass substrate of each example, a 70 × 70 mm frame shape (line width: 0.5 mm) of the above-described sealing material paste with a dispenser. Then, it was dried at 120 ° C. for 10 minutes. The average film thickness of the coating layer (dry film) of the sealing material paste was 7 μm, and the variation width of the film thickness at that time was 2.8 μm. A glass substrate on which a frame-shaped coating layer of a sealing material paste was formed was placed on a sample holder of a laser irradiation apparatus via an alumina substrate having a thickness of 0.5 mm.

  A circular laser beam having a wavelength of 940 nm, an output of 13 W, and a beam shape of 1.5 mm in diameter was irradiated along the frame-shaped coating layer of the sealing material paste. The irradiation start position of the laser beam was set at the first side of the sealing region. The scanning speed of the laser beam was 5 mm / second. The average heating temperature of the frame-shaped coating layer is 780 ° C. When the laser beam reached a position 5 mm from the baking end of the frame-shaped coating layer, the scanning speed was reduced to 0.5 mm / second and irradiated to the irradiation end position. During deceleration, the laser beam output was reduced to 7.5W. The heating temperature of the frame-shaped coating layer at this time is 770 ° C. The irradiation end position of the laser beam was set so that the overlapping irradiation distance was 5 mm. In this way, the entire frame-shaped coating layer of the sealing material paste was baked with laser light to form a sealing material layer.

Next, a first glass substrate having a sealing material layer and a second glass substrate (a glass substrate having the same composition and shape as the first glass substrate) were laminated. A laser beam having a wavelength of 940 nm, an output of 33 W, and a beam shape of 1.5 mm in diameter is irradiated while scanning along the sealing material layer through the first glass substrate to melt and rapidly solidify the sealing material layer. Thus, the first glass substrate and the second glass substrate were sealed to prepare an airtight member. About the airtight member of each example obtained in this way, the presence or absence of a crack of a glass substrate and airtightness were investigated. The airtightness of the airtight member was measured by a He leak test (vacuum method), and the case where the leak amount was 0.9 × 10 ⁻¹⁰ [Pa · m ³ / s] or less was determined as “airtight”. These measurement results are shown in Tables 4 and 5.

  As is apparent from Tables 4 and 5, the hermetic members of Examples 1 to 6 manufactured by applying the sealing material layer forming step with a wide temperature margin of the heating temperature in the laser firing step were not cracked on the glass substrate. Generation | occurrence | production is not recognized, but the outstanding airtightness is acquired by this. On the other hand, in the airtight members of Comparative Examples 1 to 8 produced by applying the sealing material layer forming step with a narrow heating temperature margin, cracks are generated in the glass substrate, and thus the airtightness is impaired. Yes. As described above, the stability and reliability of the laser firing process and the laser sealing process can be improved by widening the temperature margin of the heating temperature in the laser firing process.

  DESCRIPTION OF SYMBOLS 1 ... 1st glass substrate, 1a ... 1st surface, 2 ... 2nd glass substrate, 2a ... 2nd surface, 3 ... 1st sealing area | region, 4 ... 2nd sealing area | region, 5 ... Sealing material layer, 6 ... Frame-shaped coating layer of sealing material paste, 7 ... Laser light for firing, 8 ... Laser light for sealing, 9 ... Sealing layer, 10 ... Airtight member, 11 ... Airtight space.

Claims (13)

Preparing a glass substrate having a sealing region;
Applying a sealing material paste prepared by mixing a sealing material containing a sealing glass and a laser absorber with an organic binder in a frame shape on the sealing region of the glass substrate;
The organic binder in the frame-shaped coating layer is removed by irradiating a laser beam while scanning the frame-shaped coating layer of the sealing material paste and heating the entire frame-shaped coating layer with the laser beam. And a step of firing the sealing material to form a sealing material layer,
The method for producing a glass member with a sealing material layer, wherein the glass substrate has a compaction value of 60 ppm or less.   The method for producing a glass member with a sealing material layer according to claim 1, wherein the glass substrate has a strain point of 600 ° C. or more.   The frame-shaped coating layer is irradiated with the laser light so that the heating temperature of the sealing material is in the range of (T + 80 ° C.) to (T + 550 ° C.) with respect to the softening temperature T (° C.) of the sealing glass. The manufacturing method of the glass member with a sealing material layer of Claim 1 or 2 characterized by the above-mentioned.   The scanning speed of the laser light in the end region from the position close to the irradiation end position where at least a part of the frame-shaped coating layer has already been baked overlaps the irradiation end position, and the frame shape excluding the end region The method for producing a glass member with a sealing material layer according to any one of claims 1 to 3, wherein the glass member is decelerated from a scanning speed of the laser light in a scanning region along the coating layer.   The scanning speed of the laser beam in the scanning area is controlled in a range of 3 to 20 mm / second, and the scanning speed of the laser beam in the end area is changed from the baked portion of the frame-shaped coating layer to the beam diameter of the laser light. 5. The method for producing a glass member with a sealing material layer according to claim 4, wherein the scanning speed at a position 1.2 times before is controlled to be 2 mm / second or less.   The irradiation end position of the laser beam is a range from a position where a portion of the frame-shaped coating layer overlaps the fired portion to a position where the overlapping irradiation region of the laser beam is 20 times or less the beam diameter of the laser beam. 6. The method for producing a glass member with a sealing material layer according to claim 4, wherein the glass member is provided with a sealing material layer.   The glass member with a sealing material layer according to any one of claims 1 to 6, wherein the frame-shaped coating layer of the sealing material paste has a thickness of 15 µm or less after firing. Manufacturing method.   The sealing material includes 0.1 to 40% by volume of the laser absorber and a low expansion filler in the range of 0 to 50% by volume as a total amount of the laser absorber and the low expansion filler. The method for producing a glass member with a sealing material layer according to any one of claims 1 to 7, wherein the glass member has a content of 0.1 to 50% by volume. Preparing a first glass substrate having a first surface provided with a first sealing region;
Preparing a second glass substrate having a second surface provided with a second sealing region;
A step of applying a sealing material paste prepared by mixing a sealing material containing a sealing glass and a laser absorber with an organic binder in a frame shape on the first sealing region of the first glass substrate. When,
The organic binder in the frame-shaped coating layer is irradiated with a laser beam for firing while scanning along the frame-shaped coating layer of the sealing material paste, and the entire frame-shaped coating layer is heated with the laser beam. Baked the sealing material while forming a sealing material layer,
Laminating the first glass substrate and the second glass substrate through the sealing material layer while facing the first surface and the second surface;
The first glass is irradiated with laser light for sealing through the first glass substrate or the second glass substrate while scanning along the sealing material layer to melt and solidify the sealing material layer. Forming a sealing layer that hermetically seals a gap between the substrate and the second glass substrate,
The method for producing an airtight member, wherein the first glass substrate has a compaction value of 60 ppm or less.   The method for manufacturing an airtight member according to claim 9, wherein the first glass substrate has a strain point of 600 ° C. or higher.   The method for manufacturing an airtight member according to claim 9 or 10, wherein the second glass substrate has a compaction value of 170 ppm or less.   The flame laser beam is applied to the frame-shaped coating layer so that the heating temperature of the sealing material is in the range of (T + 80 ° C.) to (T + 550 ° C.) with respect to the softening temperature T (° C.) of the sealing glass. The method for manufacturing an airtight member according to claim 9, wherein the airtight member is irradiated.   The scanning speed of the firing laser light in the end region from the position close to the irradiation end position where at least a part of the frame-shaped coating layer is already baked overlaps the irradiation end position is excluded from the end region. The method for manufacturing an airtight member according to any one of claims 9 to 12, characterized in that the airtight member is decelerated from a scanning speed of the firing laser light in a scanning region along the frame-shaped coating layer.

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