JP2013047170A - Glass substrate with sealing material layer, organic el device using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide glass substrate with a sealing material layer suitable for laser sealing enhancing the reliability of an organic EL display or others.SOLUTION: This glass substrate with a sealing material layer is equipped with a sealing material layer that is formed by sintering a sealing material, and is characterized in that: the sealing material includes at least an inorganic powder; the inorganic powder includes a glass powder and a fire resistant filler; the content of fire resistant filler in the inorganic powder is 10-35 vol.%; and the surface roughness (Ra) of the sealing material layer is less than 0.5 μm.

Description

  TECHNICAL FIELD The present invention relates to a glass substrate with a sealing material layer and an organic EL device using the same, specifically, a glass substrate with a sealing material layer suitable for laser sealing (hereinafter referred to as laser sealing) and the same. It is related with the used organic EL device.

  In recent years, organic EL displays have attracted attention as flat display panels. Since the organic EL display can be driven by a direct current voltage, the driving circuit can be simplified, and there are advantages such as a liquid crystal display that does not depend on the viewing angle, is bright because of self-emission, and has a high response speed. Currently, organic EL displays are mainly used in small portable devices such as mobile phones, but in the future, application to ultra-thin televisions is expected. Note that the organic EL display is mainly driven by disposing an active element such as a thin film transistor (TFT) in each pixel in the same manner as a liquid crystal display.

  The organic EL display is composed of two glass substrates, a negative electrode such as metal, an organic light emitting layer, a positive electrode such as ITO, and an adhesive material. Conventionally, an organic resin adhesive material such as an epoxy resin having a low temperature curability or an ultraviolet curable resin has been used as the adhesive material. However, organic resin adhesive materials cannot completely block gas intrusion. For this reason, when an organic resin adhesive material is used, the airtightness inside the organic EL display cannot be maintained, and as a result, the organic light emitting layer having low water resistance is easily deteriorated, and the organic EL display There is a problem that the display characteristics of the display deteriorate with time. In addition, the organic resin-based adhesive material has an advantage that the glass substrates can be bonded to each other at a low temperature. However, since the water resistance is low, when the organic EL display is used for a long time, the reliability of the display is likely to be lowered. .

  On the other hand, the sealing material containing glass powder is excellent in water resistance as compared with the organic resin-based adhesive material, and is suitable for ensuring airtightness inside the organic EL display.

  However, since glass powder generally has a softening temperature of 300 ° C. or higher, it has been difficult to apply it to an organic EL display. More specifically, when sealing glass substrates with the above-mentioned sealing material, the entire organic EL display is put into an electric furnace and baked at a temperature equal to or higher than the softening temperature of the glass powder to soften and flow the glass powder. It was necessary to let them. However, since the active element used in the organic EL display has only heat resistance of about 120 to 130 ° C., sealing the glass substrates by this method damages the active element due to heat, and the organic EL display. Display characteristics will deteriorate. In addition, since the organic light emitting material also has poor heat resistance, sealing the glass substrates by this method damages the organic light emitting material due to heat and degrades the display characteristics of the organic EL display.

US Pat. No. 6,416,375 JP 2006-315902 A

  In view of such circumstances, in recent years, laser sealing has been studied as a method for sealing an organic EL display. According to laser sealing, since only the portion to be sealed can be locally heated, it is possible to seal the glass substrates together while preventing thermal degradation of the active element or the like.

  Patent Documents 1 and 2 describe laser-sealing glass substrates of a field emission display. However, Patent Documents 1 and 2 do not describe the specific material configuration and the state of the sealing material layer (fired film), and any material configuration and the state of the sealing material layer are suitable for laser sealing. It was unknown. If the output of the laser is increased, laser sealing is possible without optimizing the material configuration and the state of the sealing material layer. In this case, the active element is heated to display the organic EL display. There is a possibility that the characteristics deteriorate.

  Then, this invention makes it a technical subject to raise the reliability of an organic electroluminescent display etc. by creating the glass substrate with a sealing material layer suitable for laser sealing.

As a result of intensive studies, the present inventors use a sealing material containing at least an inorganic powder, restrict the content of the refractory filler in the inorganic powder to a predetermined range, and improve the surface smoothness of the sealing material layer. Thus, the present inventors have found that the above technical problem can be solved, and propose as the present invention. That is, the glass substrate with a sealing material layer of the present invention is a glass substrate with a sealing material layer comprising a sealing material layer obtained by sintering a sealing material. The sealing material contains at least an inorganic powder, The glass powder and the refractory filler are contained, the content of the refractory filler in the inorganic powder is 10 to 35% by volume, and the surface roughness Ra of the sealing material layer is less than 0.5 μm. Here, “inorganic powder” refers to an inorganic material powder other than a pigment, and generally refers to a mixture of glass powder and a refractory filler. “Surface roughness Ra” refers to a value measured with a non-contact type laser film thickness meter. As the glass powder, various glass powders are available, as described below, SnO-containing glass powder or Bi ₂ O ₃ containing glass powder is preferred.

  As for the sealing material which concerns on this invention, inorganic powder contains glass powder and a refractory filler, and content of the refractory filler in inorganic powder is 10-35 volume%. If the content of the refractory filler is regulated to 10% by volume or more, the thermal expansion coefficient of the sealing material layer can be lowered and the mechanical strength of the sealing material layer can be increased. Moreover, if content of a refractory filler is controlled to 35 volume% or less, the softening fluidity | liquidity of a sealing material will become difficult to be inhibited, and it will become easy to improve the surface smoothness of a sealing material layer.

  The sealing material layer according to the present invention has a surface roughness Ra of less than 0.5 μm. If it does in this way, the adhesiveness of glass substrates will improve and laser sealing property will improve notably.

  Secondly, the glass substrate with a sealing material layer of the present invention is a glass substrate with a sealing material layer comprising a sealing material layer obtained by sintering the sealing material, and the sealing material contains an inorganic powder and a pigment, The inorganic powder includes glass powder and a refractory filler, the content of the refractory filler in the inorganic powder is 10 to 35% by volume, and the surface roughness RMS of the sealing material layer is less than 1.0 μm. And Here, “surface roughness RMS” refers to a value measured with a non-contact type laser film thickness meter.

  Third, the glass substrate with a sealing material layer of the present invention preferably has an average thickness of the sealing material layer of less than 10 μm.

  Fourthly, in the glass substrate with a sealing material layer of the present invention, the surface of the sealing material layer is preferably unpolished.

  Fifthly, in the glass substrate with a sealing material layer of the present invention, the glass powder is preferably SnO-containing glass powder. If it does in this way, since the softening point of glass powder falls, the softening point of sealing material also falls. As a result, laser sealing can be completed in a short time, and the sealing strength can be increased during laser sealing. Here, “SnO-containing glass powder” refers to a glass powder containing 20 mol% or more of SnO as a glass composition.

Sixth, the glass substrate with the sealing material layer of the present invention, the glass powder is a glass composition including, SnO 35 to _70% by the following terms of oxide, preferably contains _P 2 O 5 _10~30%. If it does in this way, it will become easy to raise the water resistance of glass, maintaining the low melting point characteristic of glass.

Seventhly, in the glass substrate with a sealing material layer of the present invention, the glass powder is preferably a Bi ₂ O ₃ -containing glass powder. If it does in this way, the softening point of glass powder will fall and the softening point of sealing material will also fall. Further, Bi ₂ O ₃ -containing glass powder is excellent in water resistance and sealing strength, so that laser sealing can be completed in a short time, and sealing strength can be ensured over a long period of time. . Here, “Bi ₂ O ₃ -containing glass powder” refers to a glass powder containing 10 mol% or more of Bi ₂ O ₃ as a glass composition.

Eighth, in the glass substrate with a sealing material layer of the present invention, the glass powder has a glass composition of Bi ₂ O ₃ 20 to 60%, B ₂ O ₃ 10 to 35%, ZnO 5 in terms of the following oxide. 40%, preferably contains _{CuO + Fe 2 O 3 5~30%} . If it does in this way, it will become easy to raise the water resistance of glass, maintaining the low melting point characteristic of glass. Furthermore, it becomes easy to increase the sealing strength. Here, “CuO + Fe ₂ O ₃ ” refers to the total amount of CuO and Fe ₂ O ₃ .

Ninth, a glass substrate with the sealing material layer of the present invention preferably has an average particle size D ₅₀ of the refractory filler is 5μm or less. In this way, since the surface smoothness of the sealing material layer is improved, it becomes easy to convert laser light into heat energy, and it becomes easy to laser-seal a glass substrate at a low output and high speed. It becomes easy to reduce the thickness of the layer. Here, the “average particle diameter D ₅₀ ” refers to a value measured by the laser diffraction method. In the volume-based cumulative particle size distribution curve measured by the laser diffraction method, the accumulated amount is accumulated from the smaller particle. Represents a particle size of 50%.

Tenth, the glass substrate with the sealing material layer of the present invention preferably the maximum particle diameter D ₉₉ of the refractory filler is less than 10 [mu] m. In this way, since the surface smoothness of the sealing material layer is improved, it becomes easy to convert laser light into heat energy, and it becomes easy to laser-seal a glass substrate at a low output and high speed. It becomes easy to reduce the thickness of the layer. 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%.

Eleventh, the glass substrate with a sealing material layer of the present invention is a kind in which the refractory filler is selected from cordierite, zircon, tin oxide, niobium oxide, zirconium phosphate ceramic, and NbZr (PO ₄ ) _3. Or it is preferable that they are 2 or more types.

Twelfth, in the glass substrate with a sealing material layer of the present invention, the sealing material preferably further contains a pigment, and the pigment is preferably carbon. If it does in this way, since laser light is converted into thermal energy with a pigment, it becomes possible to improve laser sealing nature. Moreover, carbon is excellent in color developability and has good absorption of laser light. Carbon also has the effect of preventing the SnO-containing glass powder from being altered during laser sealing, that is, the effect of preventing the oxidation of SnO in the glass composition to SnO ₂ during laser sealing. . In addition, various materials can be used as carbon, and amorphous carbon or graphite is particularly preferable.

  Thirteenthly, in the glass substrate with a sealing material layer of the present invention, the content of the pigment in the sealing material is preferably 0.2 to 0.7% by mass. If the pigment content is regulated to 0.2% by mass or more, the laser light can be efficiently converted into thermal energy, so that only the portion to be sealed can be easily heated locally. It becomes easy to laser seal glass substrates together while preventing deterioration. On the other hand, if the pigment content is regulated to 1% by mass or less, excessive heating during laser irradiation can be suppressed, and it is easy to prevent the glass from devitrifying during laser sealing.

  Fourteenth, the glass substrate with a sealing material layer of the present invention is preferably used for sealing an organic EL device. Here, the “organic EL device” includes an organic EL display, organic EL lighting, and the like.

  Fifteenth, the glass substrate with a sealing material layer of the present invention is preferably used for laser sealing. Note that, as described above, according to laser sealing, only the portion to be sealed can be locally heated, so that the glass substrates can be sealed together while preventing thermal degradation of the active element or the like.

Various lasers can be used for laser sealing. 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.

Sixteenth, the glass substrate with a sealing material layer of the present invention is preferably used for laser sealing in an inert atmosphere. Here, the “inert atmosphere” includes a neutral gas atmosphere such as an N ₂ gas atmosphere and an Ar gas atmosphere, and a reduced pressure atmosphere such as a vacuum atmosphere.

  Seventeenth, the organic EL device of the present invention is manufactured using the above glass substrate with a sealing material layer.

It is a schematic diagram which shows the softening point when it measures with a macro type | mold DTA apparatus.

  The inorganic powder according to the present invention includes glass powder and a refractory filler. Preferred configurations of the glass powder and the refractory filler are as follows.

The glass powder according to the present invention is preferably a SnO-containing glass powder, and the SnO-containing glass powder has a molar composition% in terms of the following oxide as a glass composition, SnO 35-70%, P ₂ O ₅ 10-30%. It is preferable to contain. The reason for limiting the glass composition range as described above will be described below. In the description of the glass composition range below,% indicates a mol% unless otherwise specified.

  SnO is a component that lowers the melting point of glass. The content is preferably 35 to 70%, 40 to 70%, particularly preferably 50 to 68%. If the SnO content is 50% or more, the glass is softened and fluidized easily during laser sealing. If the content of SnO is less than 35%, the viscosity of the glass becomes too high, and it becomes difficult to perform laser sealing with a desired laser output. On the other hand, if the SnO content is more than 70%, vitrification becomes difficult.

P ₂ O ₅ is a glass-forming oxide and is a component that enhances thermal stability. The content is preferably 10 to 30%, 15 to 27%, particularly preferably 15 to 25%. If the content of P ₂ O ₅ is less than 10%, the thermal stability tends to be lowered. On the other hand, when the content of P ₂ O ₅ is more than 30%, the weather resistance is lowered, and it is difficult to ensure long-term reliability of an organic EL device or the like.

  In addition to the above components, the following components can be added.

  ZnO is an intermediate oxide and a component that stabilizes the glass. The content is preferably 0 to 30%, 1 to 20%, particularly preferably 1 to 15%. If the ZnO content is more than 30%, the thermal stability tends to decrease.

B ₂ O ₃ is a glass-forming oxide and a component that stabilizes the glass. _Further, B 2 _{O 3} is a component for enhancing the weather resistance. The content is preferably 0 to 20%, 1 to 20%, particularly preferably 2 to 15%. When the content of B ₂ O ₃ is more than 20%, the viscosity of the glass becomes too high, and it becomes difficult to perform laser sealing with a desired laser output.

Al ₂ O ₃ is an intermediate oxide and a component that stabilizes the glass. Al ₂ O ₃ is a component that lowers the thermal expansion coefficient. The content is preferably 0 to 10%, 0.1 to 10%, particularly preferably 0.5 to 5%. When the content of Al ₂ O ₃ is more than 10%, the softening point of the glass powder is unreasonably raised and it becomes difficult to perform laser sealing with a desired laser output.

SiO ₂ is a glass-forming oxide and is a component that stabilizes the glass. The content is preferably 0 to 15%, particularly preferably 0 to 5%. When the content of SiO ₂ is more than 15%, the softening point of the glass powder is unreasonably raised, and it becomes difficult to perform laser sealing with a desired laser output.

In ₂ O ₃ is a component that enhances thermal stability, and its content is preferably 0 to 5%. When the content of In ₂ O ₃ is more than 5%, the batch cost increases.

Ta ₂ O ₅ is a component that enhances thermal stability, and its content is preferably 0 to 5%. When the content of Ta ₂ O ₅ is more than 5%, the softening point of the glass powder is unreasonably raised and it becomes difficult to perform laser sealing with a desired laser output.

La ₂ O ₃ is a component that enhances thermal stability and is a component that enhances weather resistance. The content is preferably 0 to 15%, 0 to 10%, particularly preferably 0 to 5%. When the content of La ₂ O ₃ is more than 15%, batch cost soars.

MoO ₃ is a component that enhances thermal stability, and its content is preferably 0 to 5%. When the content of MoO ₃ is more than 5%, the softening point of the glass powder is unreasonably raised and it becomes difficult to perform laser sealing with a desired laser output.

WO ₃ is a component that enhances thermal stability, and its content is preferably 0 to 5%. When the content of WO ₃ is more than 5%, the softening point of the glass powder is unreasonably raised and it becomes difficult to perform laser sealing with a desired laser output.

Li ₂ O is a component that lowers the melting point of glass, and its content is preferably 0 to 5%. When the content of Li ₂ O is more than 5%, the thermal stability tends to be lowered.

Na ₂ O is a component that lowers the melting point of glass, and its content is preferably 0 to 10%, particularly preferably 0 to 5%. When the content of Na 2 _O is greater than 10%, the thermal stability tends to decrease.

K ₂ O is a component that lowers the melting point of glass, and its content is preferably 0 to 5%. When the content of K 2 _O is more than 5%, the thermal stability tends to decrease.

  MgO is a component that enhances thermal stability, and its content is preferably 0 to 15%. When the content of MgO is more than 15%, the softening point of the glass powder rises unreasonably and it becomes difficult to perform laser sealing with a desired laser output.

  BaO is a component that enhances thermal stability, and its content is preferably 0 to 10%. When there is more content of BaO than 10%, the component balance of a glass composition will be impaired and it will become easy to devitrify glass conversely.

F ₂ is a component to lower the melting point of the glass, the content thereof is preferably 0 to 5%. When the content of F ₂ is more than 5%, the thermal stability tends to decrease.

In consideration of thermal stability and low melting point characteristics, In ₂ O ₃ , Ta ₂ O ₅ , La ₂ O ₃ , MoO ₃ , WO ₃ , Li ₂ O, Na ₂ O, K ₂ O, MgO, BaO, The total amount of F ₂ is preferably 10% or less, particularly preferably 5% or less.

  In addition to the above components, other components (CaO, SrO, etc.) can be added, for example, up to 10%.

  It is preferable that a transition metal oxide is not included substantially. If it does in this way, it will become easy to improve thermal stability. Here, “substantially no transition metal oxide” refers to the case where the content of the transition metal oxide in the glass composition is less than 3000 ppm (mass), preferably less than 1000 ppm (mass).

  From an environmental viewpoint, it is preferable that PbO is not substantially contained. Here, “substantially does not contain PbO” refers to a case where the content of PbO in the glass composition is less than 1000 ppm (mass).

Glass powder according to the present invention, _Bi 2 _{O 3} containing glass powder is also preferable, _Bi 2 _{O 3} containing glass powder, as a glass composition, in mole as% terms of _oxide, Bi ₂ O 3 20 to 60%, _{B 2 O 3 10~35%, 5~40} % ZnO, preferably contains _{CuO + Fe 2 O 3 5~30%} . The reason for limiting the glass composition range as described above will be described below. In the description of the glass composition range below,% indicates a mol% unless otherwise specified.

Bi ₂ O ₃ is a main component for lowering the softening point, and its content is 20 to 60%, preferably 25 to 55%, more preferably 30 to 55%. If the content of Bi ₂ O ₃ is less than 20%, 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 60%, the glass becomes thermally unstable, and the glass is easily devitrified at the time of melting or laser sealing.

B ₂ O ₃ is a component that forms a glass network of bismuth-based glass, and its content is 10 to 35%, preferably 15 to 30%, and more preferably 15 to 28%. When the content of B ₂ O ₃ is less than 10%, the glass becomes thermally unstable, and the glass tends to be devitrified at the time of melting or laser sealing. On the other hand, if the content of B ₂ O ₃ is more than 35%, 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 or laser sealing and lowers the coefficient of thermal expansion, and its content is 5 to 40%, preferably 5 to 35%, more preferably 5 to 33. %. If the ZnO content is less than 5%, it is difficult to obtain the above effect. On the other hand, when the ZnO content is more than 40%, the component balance in the glass composition is impaired, and conversely, the glass is easily devitrified.

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 or laser sealing. The content of CuO + Fe ₂ O ₃ is 5 to 30%, preferably 7 to 25%, more preferably 10 to 20%. If the content of CuO + Fe ₂ O ₃ is less than 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 30%, is impaired balance of components in the glass composition, the glass is liable to devitrify reversed.

  CuO is a component having light absorption characteristics, and when irradiated with laser light having a predetermined emission center wavelength, it is a component that absorbs laser light and softens the glass, and at the time of melting or laser sealing It is a component that suppresses devitrification. The content of CuO is preferably 0 to 25%, 5 to 25%, 10 to 25%, particularly 10 to 20%. When there is more content of CuO than 25%, the component balance in a glass composition will be impaired, and it will become easy to devitrify glass conversely. If the CuO content is regulated to 5% or more, the light absorption characteristics are improved, and the glass is easily softened during laser sealing.

Fe ₂ O ₃ is a component having light absorption characteristics. When irradiated with laser light having a predetermined emission center wavelength, Fe ₂ O ₃ is a component that absorbs the laser light and softens the glass, and at the time of melting or laser. It is a component that suppresses devitrification at the time of sealing. The content of Fe ₂ O ₃ is preferably 0 to 10%, 0.1 to 10%, 0.2 to 10%, particularly 0.5 to 10%. When the content of Fe ₂ O ₃ is more than 10%, 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 0.1% 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%, in particular 0 to 3%. 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%, particularly 0 to 2%. 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 or laser sealing, and the content of MgO + CaO + SrO + BaO is preferably 0 to 20%, particularly 0 to 15%. It is. If the content of MgO + CaO + SrO + BaO is more than 20%, 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 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 or laser sealing. The content of BaO is preferably 0 to 15%, in particular 0 to 10%. When the content of BaO is more than 15%, 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 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 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 during melting 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.

In the sealing material according to the present invention, the average particle diameter D50 of the glass powder is preferably less than 15 μm, 0.5 to 10 μm, and particularly preferably 1 to ₅ μm. When regulating the average particle diameter D ₅₀ of the glass powder to less than 15 [mu] m, liable to narrow the gap between the two glass substrates, in this case, the time required for the laser sealing is reduced, the thermal expansion coefficient of the sealing material layer Even if there is a difference between the thermal expansion coefficients of the glass substrate and the glass substrate, cracks or the like are hardly generated in the sealed portion or the glass substrate.

In the sealing material of the present invention, the maximum particle diameter _{D 99} of the glass powder is 15μm or less, 10 [mu] m or less, particularly 7μm or less. When regulating the maximum particle diameter D ₉₉ of the glass powder is 15μm or less, tends to narrow the gap between the two glass substrates, in this case, the time required for the laser sealing is reduced, the thermal expansion coefficient of the sealing material layer Even if there is a difference between the thermal expansion coefficients of the glass substrate and the glass substrate, cracks or the like are hardly generated in the sealed portion or the glass substrate.

  The inorganic powder according to the present invention includes a refractory filler. In this way, the thermal expansion coefficient of the sealing material layer can be reduced, and the mechanical strength of the sealing material layer can be increased. The mixing ratio of the glass powder and the refractory filler in the inorganic powder is preferably 65 to 90%: 10 to 35%, particularly 67 to 80%: 20 to 33% by volume. When there is more content of a refractory filler than 35 volume%, the softening fluidity | liquidity of a sealing material will be inhibited and the surface smoothness of a sealing material layer will fall easily. As a result, the efficiency of laser sealing tends to decrease. In addition, it becomes difficult to receive the said effect by a refractory filler as content of a refractory filler is less than 10 volume%.

The average particle diameter _{D 50} of the refractory filler is 2μm or less, 1.7 [mu] m or less, particularly 0.1~1.5μm is preferred. When the refractory average particle diameter D ₅₀ of the filler is too large, easily thickness of the sealing material layer is locally increased and the gap between the glass substrates becomes uneven, the reliability of the laser sealing is liable to lower Become.

Maximum particle diameter _{D 99} of the refractory filler is 5μm or less, 4 [mu] m or less, particularly 0.2~3μm is preferred. If the maximum particle diameter D ₉₉ of the refractory filler is too large, easily thickness of the sealing material layer is locally increased and the gap between the glass substrates becomes uneven, the reliability of the laser sealing is liable to lower Become.

Zircon, zirconia, tin oxide, quartz, β-spodumene, cordierite, mullite, quartz glass, β-eucryptite, β-quartz, zirconium phosphate, zirconium phosphate tungstate, zirconium tungstate as refractory filler NbZr (PO ₄ ) _{3 and} other compounds having a basic structure of [AB ₂ (MO ₄ ) ₃ ],
A: Li, Na, K, Mg, Ca, Sr, Ba, Zn, Cu, Ni, Mn etc. B: Zr, Ti, Sn, Nb, Al, Sc, Y etc. M: P, Si, W, Mo etc. Alternatively, these solid solutions can be used.

Of the above refractory fillers, zirconium phosphate, cordierite, and zirconium tungstate phosphate are preferred. These refractory fillers have properties of low thermal expansion coefficient and high mechanical strength, and have good compatibility with SnO-containing glass powder or Bi ₂ O ₃ -containing glass powder.

  In the sealing material according to the present invention, the content of the inorganic powder is preferably 97.5 to 100% by mass, 99.3 to 99.8% by mass, particularly 99.4 to 99.7% by mass. If the content of the inorganic powder is too small, the softening fluidity of the sealing material layer becomes poor during laser sealing, and it becomes difficult to increase the sealing strength. In addition, when using SnO containing glass powder as glass powder, it is preferable to add a pigment in addition to the inorganic powder. In this case, if the content of the inorganic powder is too large, the content of the pigment is relatively reduced. It becomes difficult to convert laser light into thermal energy.

  In the sealing material according to the present invention, when a pigment is added, the content of the pigment is 0.2 to 2.5 mass%, 0.2 to 0.7 mass%, particularly 0.3 to 0.6 mass%. Is preferred. If the pigment content is too small, it becomes difficult to convert laser light into heat energy. On the other hand, if the pigment content is too high, the sealing material layer is excessively heated during laser sealing, and the thermal degradation of the device proceeds and the glass sealing is easily devitrified. The strength tends to decrease.

The average particle diameter D50 of the primary particles of the pigment is preferably 1 to 100 nm, 3 to 70 nm, 5 to 60 nm, and particularly preferably 10 to ₅₀ nm. If the primary particles of the pigment are too small, the pigments tend to aggregate together, making it difficult to uniformly disperse the pigment in the sealing material, and the glass powder may not locally soften and flow during laser sealing. There is. In addition, even if the primary particles of the pigment are too large, it is difficult to uniformly disperse the pigment in the sealing material, and the glass powder may not be locally softened and flowed during laser sealing.

As the pigment, an inorganic pigment is preferable, and _one or two kinds selected from carbon, Co ₃ O ₄ , CuO, Cr ₂ O ₃ , Fe ₂ O ₃ , MnO ₂ , SnO, and Ti _n O _2n-1 (n is an integer). The above is more preferable, and carbon is particularly preferable. These pigments are excellent in color developability and have good absorption of laser light. As the glass powder, when using a _Bi 2 _{O 3} containing glass powder, pigments, from the viewpoint of compatibility, Cu, Cr, Fe, oxide-based pigment comprising one or two or more of Mn is preferred.

As carbon, amorphous carbon and griffite are preferable. These carbon has a property of easily processing the average particle diameter _{D 50} of the primary particles in the 1 to 100 nm.

  The pigment preferably contains substantially no Cr-based oxide from the environmental viewpoint. Here, “substantially does not contain Cr-based oxide” refers to a case where the content of Cr-based oxide in the pigment is less than 1000 ppm (mass).

  In the sealing material according to the present invention, the softening point is preferably 500 ° C. or lower, 470 ° C. or lower, 450 ° C. or lower, 420 ° C. or lower, and particularly preferably 400 ° C. or lower. When the softening point is higher than 500 ° C., the laser sealing property tends to be lowered. The lower limit of the softening point is not particularly limited, but it is preferable to limit the softening point to 300 ° C. or higher in consideration of the thermal stability of the glass powder. Here, the “softening point” refers to a value measured with a macro-type differential thermal analysis (DTA) apparatus in a nitrogen 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 according to the present invention and a vehicle are preferably kneaded and processed into a sealing material paste. If it does in this way, workability | operativity etc. can be improved. The vehicle usually contains a resin binder and a solvent.

  As the resin binder, aliphatic polyolefin carbonates, particularly polyethylene carbonate and polypropylene carbonate are preferred. These resin binders have a characteristic that it is difficult to denature glass powder, particularly SnO-containing glass powder, during binder removal or laser sealing.

  Solvents include N, N'-dimethylformamide, ethylene glycol, dimethyl sulfoxide, dimethyl carbonate, propylene carbonate, butyrolactone, caprolactone, N-methyl-2-pyrrolidone, phenyl diglycol (PhDG), dibutyl phthalate (DBP) , One or more selected from benzyl glycol (BzG), benzyl diglycol (BzDG), and phenyl glycol (PhG) are preferred. These solvents have a characteristic that glass powder, particularly SnO-containing glass powder, is hardly altered during binder removal or laser sealing. In particular, among these solvents, one or two selected from propylene carbonate, phenyl diglycol (PhDG), dibutyl phthalate (DBP), benzyl glycol (BzG), benzyl diglycol (BzDG), and phenyl glycol (PhG). The above is preferable. These solvents have a boiling point of 240 ° C. or higher. For this reason, when these solvents are used, it becomes easy to suppress the volatilization of the solvent during application work such as screen printing, and as a result, the sealing material paste can be used stably for a long period of time. . Furthermore, phenyl diglycol (PhDG), dibutyl phthalate (DBP), benzyl glycol (BzG), benzyl diglycol (BzDG), and phenyl glycol (PhG) have high affinity with pigments. For this reason, even if the addition amount of these solvents is small, the situation where a pigment separates in the sealing material paste can be suppressed.

When the SnO-containing glass powder is used as the glass powder, the sealing material paste of the present invention is preferably subjected to a debinding treatment in an inert atmosphere, and particularly preferably subjected to a debinding treatment in an N ₂ atmosphere. . If it does in this way, it will become easy to prevent the situation where a glass powder, especially SnO containing glass powder degenerates in the case of binder removal.

The sealing material paste of the present invention is preferably used for laser sealing in an inert atmosphere, and particularly preferably used for laser sealing in an N ₂ atmosphere. If it does in this way, it will become easy to prevent the situation where a glass powder, especially SnO containing glass powder degenerates in the case of laser sealing.

  In the glass substrate with a sealing material layer of the present invention, the surface roughness Ra of the sealing material layer is preferably less than 0.5 μm, 0.3 μm or less, 0.2 μm or less, and particularly preferably 0.01 to 0.15 μm or less. If it does in this way, the adhesiveness of glass substrates will improve and laser sealing property will improve notably.

  In the glass substrate with a sealing material layer of the present invention, the surface roughness RMS of the sealing material layer is preferably less than 1.0 μm, 0.7 μm or less, 0.5 μm or less, particularly 0.05 to 0.3 μm or less. If it does in this way, the adhesiveness of glass substrates will improve and laser sealing property will improve notably.

  In the glass substrate with a sealing material layer of the present invention, the average thickness of the sealing material layer is preferably less than 10 μm, less than 7 μm, 0.1 to 5.5 μm, particularly preferably less than 1 to 5 μm. In this way, even if there is a difference between the thermal expansion coefficient of the sealing material layer and the thermal expansion coefficient of the glass substrate, cracks and the like are less likely to occur in the glass substrate and the sealing portion. As a result, since the content of the refractory filler can be reduced, the softening fluidity of the sealing material is improved, and the surface smoothness of the sealing material layer can be increased.

  In the glass substrate with a sealing material layer of the present invention, the thickness variation of the sealing material layer is preferably 2 μm or less, particularly preferably 1 μm or less. If it does in this way, the adhesiveness of glass substrates will improve.

  The surface of the sealing material layer may be polished to improve the surface smoothness of the sealing material layer, but the surface of the sealing material layer is preferably unpolished. In this way, the polishing process becomes unnecessary, and the manufacturing cost can be easily reduced.

Currently, an active matrix drive in which an active element such as a TFT is arranged and driven in each pixel is adopted as an organic EL display as a drive method. In this case, non-alkali glass (for example, OA-10G manufactured by Nippon Electric Glass Co., Ltd.) is used for the glass substrate for organic EL display. The thermal expansion coefficient of the alkali-free glass is usually 40 × 10 ⁻⁷ / ° C. or less. Generally, it is necessary to match the thermal expansion coefficient of the sealing material with the thermal expansion coefficient of the glass substrate. However, when the thickness of the sealing material layer is less than 10 μm, particularly less than 5 μm, the thermal strain due to the difference in thermal expansion coefficient. Since the amount is small, even if the thermal expansion coefficient of the sealing material is high to some extent, the hermetic sealing can be performed well. And if the thermal expansion coefficient of the sealing material is increased, the content of the refractory filler can be reduced, so that the softening fluidity of the sealing material is improved and the surface smoothness of the sealing material layer is improved. It becomes possible to increase. Therefore, in the sealing material according to the present invention, the thermal expansion coefficient is preferably 60 × 10 ⁻⁷ / ° C. or more and 85 × 10 ⁻⁷ / ° C. or less. Here, the “thermal expansion coefficient” refers to an average value measured in a temperature range of 30 to 250 ° C. by a push rod type thermal expansion coefficient measurement (TMA) apparatus.

  The organic EL device of the present invention is produced using the above glass substrate with a sealing material layer. The technical characteristics (preferable material configuration and preferable characteristics) of the organic EL device of the present invention have already been described in the description of the glass substrate with a sealing material layer of the present invention. Here, the description is omitted for convenience.

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

Table 1 shows SnO-containing glass powders (Sample Nos. 1 to 7). Table 2 shows Bi ₂ O ₃ -containing glass powder (sample Nos. 8 to 14).

SnO-containing glass powder was prepared as follows. First, after preparing the raw materials so as to have the glass composition shown in Table 1, the prepared raw materials were put in an alumina crucible and melted at 900 ° C. for 1 to 2 hours in a nitrogen atmosphere. Next, the obtained molten glass was formed into a film shape with a water-cooled roller. Subsequently, the glass film was pulverized by a ball mill and classified to obtain SnO-containing glass powder. The particle size of the obtained SnO-containing glass powder was an average particle size D ₅₀ : 1.7 μm and a maximum particle size D ₉₉ : 5.0 μm.

Bi ₂ O ₃ containing glass powder was prepared as follows. First, after preparing the raw materials so as to have the glass composition shown in Table 2, the prepared raw materials were put in a platinum crucible and melted at 1000 to 1100 ° C. for 1 to 2 hours in an air atmosphere. Next, the obtained molten glass was formed into a film shape with a water-cooled roller. Subsequently, the glass film was pulverized by a ball mill and classified to obtain a Bi ₂ O ₃ -containing glass powder. The particle size of the obtained Bi ₂ O ₃ -containing glass powder was an average particle size D ₅₀ : 1.2 μm and a maximum particle size D ₉₉ : 4.0 μm.

  Sample No. About 1-14, the glass transition point, the softening point, and the thermal expansion coefficient were evaluated. The results are shown in Tables 1 and 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. When the SnO-containing glass powder was included, the measurement was performed under an atmosphere of nitrogen, and when the Bi ₂ O _3- containing glass powder was included, the measurement was started from room temperature at a heating rate of 10 ° C./min.

The thermal expansion coefficient is a value measured by a push rod type TMA apparatus. In the case of using SnO-containing glass powder, 30 to 250 ° C. The measurement temperature range, when using a _Bi 2 _{O 3} containing glass powder, and the measurement temperature range and 30 to 300 ° C..

As is clear from Table 1, sample No. 1 to 7 had a glass transition point of 295 to 334 ° C., a softening point of 364 to 405 ° C., and a thermal expansion coefficient of 96 × 10 ^{−7 to} 125 × 10 ⁻⁷ / ° C.

As apparent from Table 2, the sample No. 8 to 14 had a glass transition point of 350 to 365 ° C., a softening point of 419 to 435 ° C., and a thermal expansion coefficient of 98 to 107 × 10 ⁻⁷ / ° C.

  Next, the glass powder described in Tables 1 and 2, the refractory filler, and a pigment as necessary are mixed so that the mixing ratios described in Tables 3 and 4 are obtained. To N).

When SnO-containing glass powder is used as the refractory filler, zirconium phosphate and zirconium tungstate phosphate are used. When Bi ₂ O ₃ -containing glass powder is used, cordierite is used. The particle sizes of zirconium phosphate and zirconium tungstate phosphate were the average particle size D ₅₀ : 1.1 μm and the maximum particle size D ₉₉ : 2.4 μm, respectively. The particle size of the cordierite was an average particle diameter D ₅₀ : 0.9 μm and a maximum particle diameter D ₉₉ : 2.1 μm.

When using SnO-containing glass powder, ketjen black (graphite) was used as a pigment. The average particle diameter _{D 50} of the primary particles was 20 nm.

  Samples A to N were evaluated for glass transition point, softening point, thermal expansion coefficient, sealing material layer thickness, sealing material layer surface roughness, and laser sealing property. The results are shown in Tables 3 and 4.

  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. When the SnO-containing glass powder was included, the measurement was performed under a nitrogen atmosphere. When the Bi ₂ O _3- containing glass powder was included, the measurement was performed under an air atmosphere, and the measurement was started from room temperature at a temperature increase rate of 10 ° C./min.

The thermal expansion coefficient is a value measured by a push rod type TMA apparatus. In the case of using a SnO-containing glass powder, 30 to 250 ° C. The measurement temperature range, the use of _Bi 2 _{O 3} containing glass powder, and the measurement temperature range and 30 to 300 ° C..

  A sealing material paste was prepared 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, the sealing material paste is thickened to about 5 μm and width is about 0.6 mm on the periphery of a 40 mm long × 50 mm wide × 0.5 mm thick glass substrate (OA-10G manufactured by Nippon Electric Glass Co., Ltd.). After being printed on a screen printer, dried at 85 ° C. for 15 minutes in an air atmosphere, and then fired at a softening point of each sample at a temperature of 50 ° C. for 10 minutes in a nitrogen atmosphere. The glass with the sealing material layer having the average thickness and surface roughness (Ra, RMS) shown in the table, incineration of the resin component in the sealing material paste (debinding process), and fixing of the sealing material A substrate was obtained.

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

  The surface roughness (Ra, RMS) of the sealing material layer is a value measured with a surface roughness meter.

  Subsequently, after a glass substrate (OA-10G manufactured by Nippon Electric Glass Co., Ltd.) having a length of 50 mm, a width of 50 mm, and a thickness of 0.5 mm is placed on the sealing material layer in a nitrogen atmosphere, a sealing material layer is formed. By irradiating a laser having a wavelength of 808 nm along the sealing material layer from the glass substrate side under the conditions described in Tables 3 and 4, the sealing material layer is softened and fluidized, and the glass substrates are hermetically sealed. I wore it.

  The laser sealing property was evaluated by observing the presence or absence of peeling at the sealing portion after the high temperature, high humidity and high pressure test: HAST test (Highly Accelerated Temperature and Humidity Stress test). The conditions of the HAST test are 121 ° C., humidity 100%, 2 atm, and 24 hours.

  As apparent from Tables 3 and 4, Samples A to E and H to L have a surface roughness Ra of 0.15 μm or less and an RMS of 0.30 μm or less, and excellent surface smoothness. It was. As a result, Samples A to E and H to L were able to join the glass substrates under all laser irradiation conditions.

  On the other hand, in Sample F, the surface roughness Ra and RMS of the sealing material layer were large, and peeling was observed at the sealing portion after the HAST test under a low output condition of 15 W or less. This fact is considered to be due to the fact that the surface smoothness of the sealing material layer is poor because the content of the refractory filler is large, and the softening fluidity of the sealing material is hindered. Moreover, since the sample G has little content of a refractory filler, it is considered difficult to match the thermal expansion coefficient of the material to be sealed. In addition, although it is thought that the sample G can bond glass substrates if a high output laser is used, it is thought that a crack is easy to generate | occur | produce in a sealing interface immediately after joining.

In sample M, the surface roughness Ra and RMS of the sealing material layer were large, and peeling was observed at the sealing portion after the HAST test under a low output condition of 15 W or less. This fact is considered to be due to the fact that the surface smoothness of the sealing material layer is poor because the content of the refractory filler is large, and the softening fluidity of the sealing material is hindered. Incidentally, the sample M is because the total amount of CuO and Fe ₂ O ₃ in the glass powder is small, there is a possibility which can not be sufficiently absorbed energy of the irradiated laser beam. Moreover, since the sample N has little content of a refractory filler, it is thought that it is difficult to match the thermal expansion coefficient of the material to be sealed. In addition, although it is thought that the sample N can bond glass substrates if a high output laser is used, it is thought that a crack is easy to generate | occur | produce in a sealing interface immediately after joining.

  The sealing material of the present invention is suitable not only for organic EL devices but also for laser sealing of solar cells such as dye-sensitized solar cells, laser sealing of lithium ion secondary batteries, laser sealing of MEMS packages, etc. It is.

Claims (17)

In a glass substrate with a sealing material layer comprising a sealing material layer obtained by sintering the sealing material,
The sealing material contains at least an inorganic powder;
The inorganic powder contains glass powder and refractory filler,
The content of the refractory filler in the inorganic powder is 10 to 35% by volume,
A glass substrate with a sealing material layer, wherein the surface roughness Ra of the sealing material layer is less than 0.5 μm. In a glass substrate with a sealing material layer comprising a sealing material layer obtained by sintering the sealing material,
The sealing material contains at least an inorganic powder;
The inorganic powder contains glass powder and refractory filler,
The content of the refractory filler in the inorganic powder is 10 to 35% by volume,
A glass substrate with a sealing material layer, wherein the surface roughness RMS of the sealing material layer is less than 1.0 μm.   The glass substrate with a sealing material layer according to claim 1 or 2, wherein the average thickness of the sealing material layer is less than 10 µm.   The glass substrate with a sealing material layer according to any one of claims 1 to 3, wherein the surface of the sealing material layer is unpolished.   The glass substrate with a sealing material layer according to any one of claims 1 to 4, wherein the glass powder is SnO-containing glass powder. Glass powder, as a glass composition, SnO 35 to _70% by the following terms of oxide, sealing according to any one of claims 1-5, characterized in that it contains _P 2 O 5 _10~30% Glass substrate with material layer. The glass substrate with a sealing material layer according to any one of claims 1 to 4, wherein the glass powder is a Bi ₂ O ₃ -containing glass powder. The glass powder contains, as a glass composition, Bi ₂ O ₃ 20 to 60%, B ₂ O ₃ 10 to 35%, ZnO 5 to 40%, CuO + Fe ₂ O ₃ 5 to 30% in terms of the following oxides. The glass substrate with a sealing material layer according to claim 1, wherein the glass substrate has a sealing material layer. With the sealing material layer glass substrate according to any one of claims 1 to 8, wherein the average particle diameter D ₅₀ of the refractory filler is 5μm or less. With the sealing material layer glass substrate according to any one of claims 1 to 9, wherein the maximum particle diameter D ₉₉ of the refractory filler is less than 10 [mu] m. The refractory filler is one or more selected from cordierite, zircon, tin oxide, niobium oxide, zirconium phosphate ceramic, and NbZr (PO ₄ ) ₃ . A glass substrate with a sealing material layer according to any one of the above.   The glass substrate with a sealing material layer according to any one of claims 1 to 6, wherein the sealing material further contains a pigment, and the pigment is carbon.   The glass substrate with a sealing material layer according to claim 12, wherein the content of the pigment in the sealing material is 0.2 to 0.7 mass%.   It uses for sealing of an organic EL device, The glass substrate with a sealing material layer as described in any one of Claims 1-13 characterized by the above-mentioned.   It uses for a laser sealing, The glass substrate with a sealing material layer as described in any one of Claims 1-14 characterized by the above-mentioned.   The glass substrate with a sealing material layer according to any one of claims 1 to 6 and 9 to 15, which is used for laser sealing in an inert atmosphere.   An organic EL device manufactured using the glass substrate with a sealing material layer according to any one of claims 1 to 16.