JP2011065895A - Glass sealer, light emitting device, and method of manufacturing the glass sealer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass sealer having frit glass in which residual stress is less and cracking is hard to occur, and to provide a light emitting device and a method of manufacturing the glass sealer. <P>SOLUTION: The glass sealer includes sealing glass and the frit glass which seals a space formed between a substrate and the sealing glass. The frit glass contains carbon black. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a glass sealed body, a light emitting device, and a method for manufacturing a glass sealed body.

  Since a glass sealed body hermetically sealed with glass can transmit light while blocking outside air, a light emitting element, a light detecting element, or the like can be incorporated. For example, organic EL (Electro-Luminescence) elements are vulnerable to moisture and oxygen, and when exposed to the outside air, dark spots and dark edges are generated, resulting in deterioration of light intensity.

  On the other hand, for example, a glass sealing body that hermetically seals an organic EL element in a space between a sealing glass and a glass substrate is an easy-to-manufacture and low-cost package. Patent Document 1 discloses a glass package that is sealed using a frit that is a low-melting glass material.

  However, in these glass sealing bodies, there is a problem that stress remains in the low-melting glass that hermetically seals between the sealing glass and the glass substrate, and cracks are easily generated to cause leakage. For this reason, there was a concern of reducing the reliability of the sealed light emitting element.

JP-T-2006-524419

  The objective of this invention is providing the manufacturing method of the glass sealing body which has frit glass with little residual stress, and is hard to produce a crack, a light-emitting device, and a glass sealing body.

According to one aspect of the present invention, it comprises a sealing glass, and a frit glass that seals a space formed between a substrate and the sealing glass, and the frit glass includes carbon black. The glass sealing body characterized by these is provided.
According to another aspect of the present invention, there is provided a light emitting device further comprising the above-described glass sealing body and a light emitting element accommodated in the space.
According to another aspect of the present invention, a step of applying a paste containing a frit material, a binder, and carbon black to at least one of the substrate and the sealing glass, and firing the applied paste. A first firing step for removing the binder; a second firing step for melting the frit material to form a frit glass containing the carbon black; and the sealing glass and the state with the frit glass interposed A glass sealing body comprising: a sealing step of overlapping a substrate, irradiating the frit glass with a laser beam, and welding the sealing glass and the substrate with the frit glass. A manufacturing method is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the glass sealing body, light-emitting device, and glass sealing body which have a frit glass with few residual stress and it is hard to produce a crack is realizable.

It is a schematic diagram which shows the cross section of the glass sealing body which concerns on one Embodiment. It is a schematic diagram which shows the manufacturing process of the glass sealing body which concerns on one Embodiment. It is a schematic diagram which shows the manufacturing process of the glass sealing body which concerns on one Embodiment. It is a schematic diagram which shows the formation process of the frit glass which concerns on one Embodiment. It is a graph which shows the welding characteristic of the frit glass which concerns on one Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same parts in the drawings are denoted by the same reference numerals, detailed description thereof will be omitted as appropriate, and different parts will be described as appropriate.

Drawing 1 is a mimetic diagram showing the section of glass sealing object 1 concerning one embodiment of the present invention.
The glass sealing body 1 has a structure in which, for example, the light emitting element 7 provided on the insulating substrate 6 is accommodated in a space 5 formed between the insulating substrate 6 and the sealing glass 2. A frit glass 15 is welded between the sealing glass 2 and the insulating substrate 6 to seal the space 5. The frit glass 15 contains carbon black. In this embodiment, an example in which an insulating substrate 6 such as a glass substrate is used will be described. However, the present invention is not limited to this, and a conductive substrate can also be used. Moreover, the glass sealing body 1 can be comprised so that the emitted light of the light emitting element 7 accommodated in the inside may be taken out from the sealing glass 2 side or the insulating substrate 6 side. That is, the glass sealing body 1 functions as a light emitting device.

  The frit glass 15 is made of magnesium oxide, calcium oxide, barium oxide, lithium oxide, sodium oxide, potassium oxide, boron oxide, vanadium oxide, zinc oxide, tellurium oxide, aluminum oxide, silicon dioxide, lead oxide, tin oxide, oxide. Selected from the group consisting of phosphorus, ruthenium oxide, rhodium oxide, iron oxide, copper oxide, titanium oxide, tungsten oxide, bismuth oxide, antimony oxide, lead borate glass, tin phosphate glass, vanadate glass and borosilicate glass It is desirable to include one or more compounds.

2 and 3 are schematic views showing the manufacturing process of the glass sealing body 1. FIG.
FIG. 2A is a schematic diagram showing a process of applying a paste containing a frit material, a binder, and carbon black to the first surface of the sealing glass 2.

  For example, a paste 3 in which a frit material mainly composed of a glass composition such as silicon dioxide and boron oxide, and a resin binder diluted with an organic solvent is kneaded is discharged from a nozzle 4 and is shown in FIG. As shown, it is applied to the first surface of the sealing glass 2. In this embodiment, the paste 3 to which garbon black is added at the time of kneading is used. Further, the nozzle 4 shown in FIG. 2A is connected to a dispensing device (not shown) that supplies the paste 3.

  The application of the paste 3 is not limited to the dispensing method, and a screen printing method or the like can also be used.

  As shown in FIG. 2B, after the paste 3 surrounding the space to be sealed is applied to the first surface of the sealing glass 2, the paste 3 is fired to vaporize and remove the organic solvent and the resin binder. A process (first baking process) is performed.

  In order to efficiently remove the organic solvent and the resin binder, the pre-baking is preferably performed in an atmosphere containing oxygen. This is because the organic solvent and the resin can be oxidized and released as carbon dioxide.

  Next, a main firing step (second firing step) is performed in which the paste 3 from which the organic solvent and the resin binder have been removed is melted to obtain the frit glass 15 containing carbon black. In the main firing, the glass component that is the main component of the frit material contained in the paste 3 is softened and integrated. For this reason, it is carried out at a higher temperature than the preliminary firing.

  The main baking is preferably performed in an atmosphere of an inert gas, a reducing gas or a vacuum so that the carbon black added to the paste 3 is not oxidized or volatilized.

  FIG. 3A schematically shows a state in which the sealing glass 2 and the insulating substrate 6 are overlapped with the first surface of the sealing glass 2 on which the frit glass 15 is formed facing the light emitting element 7. It is sectional drawing shown. FIG. 3B shows a sealing process in which the frit glass 15 is irradiated with laser light from the second surface side of the sealing glass 2 and the sealing glass 2 and the insulating substrate 6 are welded with the frit glass 15. It is a schematic diagram shown.

  For example, a semiconductor laser device or a YAG laser device that emits laser light having a wavelength of 810 nm can be used as the laser device 8 that emits laser light. In the glass sealing body 1 according to the present embodiment, since carbon black that efficiently absorbs infrared rays is added to the frit glass 15, the laser device has a relatively low power compared to the case where no carbon black is added. Can be used.

  Further, as indicated by an arrow in FIG. 3B, the laser light is scanned along the frit glass 15 formed on the first surface of the sealing glass 2. Thereby, the space between the sealing glass 2 and the insulating substrate 6 is welded, and the space 5 in which the light emitting element 7 is accommodated is sealed. At this time, the scanning speed of the laser beam can be increased compared to the case of the frit glass 15 to which no carbon black is added, and the sealing can be completed in a short time.

Further, instead of the laser light irradiation, the entire glass sealing body can be heated using an infrared lamp to weld the frit glass 15. However, when an infrared lamp is used, the light emitting element 7 is also heated. Therefore, when the light emitting element 7 is vulnerable to heat, for example, in the case of an organic EL element, laser light irradiation is performed as in this embodiment. It is desirable to use it.
In the specific example described above with reference to FIGS. 2 and 3, the paste 3 is applied to the sealing glass 2. However, the present invention is not limited to this. In other words, the paste 3 may be applied to the insulating substrate 6 as long as the elements formed on the insulating substrate 6 can withstand the temperatures of temporary baking and main baking. Furthermore, the paste 3 may be applied to both the sealing glass 2 and the insulating substrate 6.

FIG. 4 is a schematic view showing a frit glass forming process according to the present embodiment.
FIG. 4A is a cross-sectional view schematically showing a state in which the paste 3 is applied to the first surface of the sealing glass 2. The frit material 12 and the carbon black 13 are distributed in a resin binder 14 diluted with an organic solvent, so-called beagle.

  Next, for example, when the first baking process is performed by heating to about 300 ° C. in the air, the resin binder 14 is vaporized and removed, and as shown in FIG. 12 and carbon black 13 are left.

  Furthermore, in the main baking which is the second baking step, when the frit material 12 is heated to a temperature at which it is melted, a frit glass 15 in which the frit material 12 is integrated can be obtained as shown in FIG. At this time, the carbon black 13 is taken into the frit glass 15.

  In addition, the baking for making the paste 3 applied to the sealing glass 2 into the frit glass 15 can be performed, for example, by irradiation with an infrared lamp.

  FIG. 5 is a graph showing the welding characteristics of the frit glass according to the present embodiment. The vertical axis indicates the fusing rate of the frit glass 15, and the horizontal axis indicates the power of the laser beam to be irradiated. Here, the welding rate indicates the ratio between the width of the frit glass 15 formed on the sealing glass 2 before laser irradiation and the width of the frit glass 15 welded to the insulating substrate 6 after laser irradiation. It is an indicator. Therefore, it can be said that as the welding rate is larger, the frit glass 15 and the insulating substrate 6 are welded in a wider area, and the sealing degree is higher. Further, if the frit glass 15 spreads by welding, the welding rate may exceed 100% as shown by A in FIG.

  In FIG. 5, four sample examples are shown. Sample A is a frit glass containing carbon black, and this firing step is performed in a nitrogen atmosphere. Sample B is also a frit glass containing carbon black, and this firing step is performed in air. On the other hand, Sample C is a frit glass that does not contain carbon black, and the main firing step is performed in a nitrogen atmosphere. Sample D is also a frit glass that does not contain carbon black, and this firing step is performed in air.

  As shown in FIG. 5, the sample A shows a welding rate of about 80% when the laser power is about 10 W, and further increases over 100% to a welding rate of about 120% while the laser power increases to 15 W. Is obtained. In Sample B, although the welding rate is lower than that of Sample A, the laser power is 13 W or more, and a welding rate of 80% to 90% is obtained.

  On the other hand, Samples C and D that do not contain carbon black have a lower welding rate than Samples A and B that contain carbon black, and even if the laser power is increased to nearly 20 W, the welding rate does not reach 80%.

  That is, the difference in welding rate between when carbon black is included and when carbon black is not included is significant, and it is clear that frit glass added with carbon black can be welded with lower laser power. That is, when a frit glass added with carbon black is used, welding at a lower temperature is possible. As a result, it is possible to stably form a sealed glass body incorporating various elements such as an organic EL element having a low heat resistant temperature.

  In addition, even between sample A and sample B containing carbon black, sample A in which the firing process is performed in a nitrogen atmosphere has a higher deposition rate. This difference is considered to be due to the difference in the amount of carbon black contained in the frit glass.

  That is, in Sample B in which the main firing step was performed in the air, it was estimated that a part of the carbon black reacted with oxygen and disappeared as carbon dioxide, thereby reducing the carbon black content. As a result, it is considered that the absorption of laser light by carbon black is less than that of sample A, the temperature rise is suppressed, and the welding rate is different.

  In Samples C and D that do not contain carbon black, there is no difference in the welding rate between Sample C in which the main firing process is performed in a nitrogen atmosphere and Sample D in which air is performed in air, and the same laser power dependency is obtained. This is supported by this assumption.

  The laser power for frit glass welding is preferably small. That is, as the laser power is smaller and the irradiation range is narrower, cracks are less likely to occur during welding. Also, the stress remaining on the frit glass after welding is small.

  In addition, due to the heat storage property of the carbon black, an effect of gradually cooling the temperature of the frit glass gradually decreasing and the residual stress being reduced can be obtained.

  Therefore, by adding carbon black to the frit glass, it is possible to realize a sealed glass body in which residual stress is small and cracks are hardly generated. Further, since the laser power at the time of welding can be relatively lowered, it is desirable to increase the amount of carbon black contained in the frit glass.

  Further, in order to suppress the disappearance of carbon black, it is desirable to perform the main baking step in an atmosphere of an inert gas such as nitrogen. Furthermore, it can be carried out in an inert gas atmosphere containing a reducing gas such as hydrogen, or in a vacuum.

  Also, in the preliminary firing step, since it is heated and fired in an atmosphere containing oxygen, it is inevitable that a part of the carbon black is oxidized and disappears. Therefore, it is desirable that the carbon black itself has oxidation resistance.

  As the carbon black having oxidation resistance, a carbon black having a high purity and a crystal structure such as carbon-specific fullerene, or a metal carbide can be used.

Example 1
First, a frit material containing silicon dioxide, boron oxide and bismuth oxide, a beagle diluted with ethyl cellulose as a binder using butyl carbitol acetate as a solvent, and carbon black (0.2 wt%) are kneaded. The paste was applied to the sealing glass by a dispensing method.

  Subsequently, the sealing glass to which the paste was applied was heated to 320 ° C. in an air atmosphere and pre-baked for 40 minutes. Further, main baking was performed at 420 ° C. for 30 minutes in a nitrogen atmosphere to complete a sealing glass with frit glass.

  Next, the sealing glass with frit glass and the glass substrate provided with the organic EL element on the surface were overlapped, and the frit glass was welded by irradiation with a semiconductor laser having a wavelength of 810 nm. Thereby, the glass sealing body without a crack over the perimeter of frit glass was completed.

  The completed glass sealed body was put into a reliability test and operated for 500 hours in an environment of an ambient temperature of 85 ° C. and a humidity of 85%. As a result, it was confirmed that the EL element sealed in the glass sealing body had no dark spots or dark edges.

(Comparative Example 1)
First, a paste obtained by kneading a frit material containing silicon dioxide, boron oxide and bismuth oxide and a beagle diluted with ethyl cellulose as a binder using butyl carbitol acetate as a solvent as a solvent is applied to a sealing glass by a dispensing method. Applied.

  Subsequently, temporary baking and main baking were performed under the same conditions as in Example 1 to complete a sealing glass with frit glass.

  Next, the sealing glass with frit glass and the glass substrate provided with the organic EL element on the surface were overlapped, and the frit glass was welded by irradiation with a semiconductor laser having a wavelength of 810 nm. Then, when the completed glass sealing body was observed, the crack was seen in a part of frit glass.

  When this glass sealed body was put into a reliability test, moisture permeation was confirmed after 30 hours in an environment of an ambient temperature of 85 ° C. and a humidity of 85%, and generation of dark spots was confirmed in the organic EL element. .

  As described above, a stable operation over a long time was confirmed in the light emitting device in which the organic EL element was sealed in the glass sealing body using the frit glass added with carbon black. On the other hand, in the glass sealing body using the frit glass to which no carbon black is added, cracks are generated in the frit glass, and dark spots are generated in the enclosed organic EL element.

  As described above, as shown in the present embodiment, by adding carbon black to the frit glass, it is possible to reduce the residual stress after welding and prevent the occurrence of cracks. Furthermore, the temperature at the time of welding can be lowered. A glass sealing body using the same has a good sealing property with no leakage, and can be used, for example, as a package of various elements such as an organic EL element that easily deteriorates due to oxygen or moisture.

  Here, although the present invention has been described with reference to one embodiment according to the present invention, the present invention is not limited to these embodiments. For example, embodiments that have the same technical idea as the present invention, such as design changes and material changes that can be made by those skilled in the art based on the technical level at the time of filing, are also included in the technical scope of the present invention. Therefore, in the present invention, the light emitting element is not limited to an organic EL element, and is not limited to a light emitting device incorporating an organic EL element as a light emitting device. The present invention can also be applied to a display device having a light emitting element (including a light emitting element other than an organic EL element). For example, the light emitting device includes a plurality of light emitting elements (light emitting elements other than an organic EL element). Including a display device with a built-in).

DESCRIPTION OF SYMBOLS 1 Glass sealing body 2 Sealing glass 3 Paste 4 Nozzle 5 Space 6 Insulating substrate 7 Light emitting element 8 Laser apparatus 12 Frit material 13 Carbon black 14 Resin binder 15 Frit glass

Claims (5)

A substrate,
Sealing glass;
Frit glass for sealing a space formed between the substrate and the sealing glass;
With
The glass sealing body, wherein the frit glass contains carbon black.   The frit glass is composed of magnesium oxide, calcium oxide, barium oxide, lithium oxide, sodium oxide, potassium oxide, boron oxide, vanadium oxide, zinc oxide, tellurium oxide, aluminum oxide, silicon dioxide, lead oxide, tin oxide, phosphorus oxide, One or more selected from the group consisting of ruthenium oxide, rhodium oxide, iron oxide, copper oxide, titanium oxide, tungsten oxide, bismuth oxide, antimony oxide, lead borate glass, tin phosphate glass, vanadate glass and borosilicate glass The glass sealing body according to claim 1, comprising:   The sealed glass body according to claim 1 or 2, wherein carbon black contained in the frit glass has oxidation resistance. The glass sealing body according to any one of claims 1 to 3,
A light emitting device housed in the space;
A light-emitting device comprising: Applying a paste containing a frit material, a binder, and carbon black to at least one of the substrate and the sealing glass;
A first firing step of firing the applied paste and removing the binder;
A second firing step in which the frit material is melted to form the frit glass containing the carbon black;
A sealing process in which the sealing glass and the substrate are overlapped with the frit glass interposed, the frit glass is irradiated with laser light, and the sealing glass and the substrate are welded with the frit glass. When,
A method for producing a sealed glass body, comprising:

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