JP2003323975A - Electrooptical device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrooptical device being easy to manufacture while suppressing the occurrence of stress in a sealing resin during film sealing and having a longer service life and less defects of dark spots by suppressing contact between an organic EL element and moisture or oxygen in the atmosphere. <P>SOLUTION: The electrooptical device 1 comprises a circuit board 2 provided with an electric circuit and a sealing substrate 3 connected in opposition to the circuit board 2. It has a recessed portion 4 on the face opposite to at least one of the opposed faces of the circuit board 2 and the sealing substrate 3. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electro-optical device and an electro-optical device included in electronic equipment.

[0002]

2. Description of the Related Art In recent years, along with the diversification of information equipment and the like, there is an increasing demand for electro-optical devices that consume less power than conventional CRTs and have a smaller volume than LCDs. It's starting. As one of such electro-optical devices, an electro-optical device using an organic EL element has attracted attention.

The organic EL element has a structure in which a hole injection layer, a light emitting layer, and a cathode are laminated on ITO serving as an anode electrode on a circuit board provided with a drive circuit. In such an organic EL element, the life of the organic EL element is shortened due to contact with moisture or oxygen in the atmosphere, and defects called dark spots easily occur in the organic EL element. There is a characteristic that stable light emission cannot be obtained due to oxidation of the cathode stacked above the element. The organic EL element provided on the circuit board is covered with a sealing substrate or a sealing resin in order to prevent such deterioration of the life of the EL element due to moisture and oxygen in the atmosphere, dark spot defects, and oxidation of the cathode. The method to do is given.

As a method for covering the organic EL element with the sealing substrate, there is a method called can sealing described in JP-A No. 11-185954. In can sealing, a desiccant or oxygen scavenger is provided between the sealing substrate and the circuit board, and the organic EL is produced by contact with moisture or oxygen in the atmosphere.
It is designed to suppress the life of the device, the occurrence of dark spot defects, and the oxidation of the cathode.

Further, as a method for coating an organic EL element with a sealing resin, a method called film sealing described in JP-A-10-41067 and JP-A-11-4.
There is a method of providing an inorganic protective film described in Japanese Patent No. 0345 between the sealing resin and the organic EL element.

In the method of film sealing, the sealing resin is made thicker without providing a desiccant or an oxygen scavenger to suppress the permeation of moisture or oxygen inside the sealing resin, thereby forming an organic EL device. It is designed to completely block contact with moisture and oxygen in the atmosphere, and organic EL by contact with moisture and oxygen in the atmosphere.
It is designed to suppress the life of the device, the occurrence of dark spot defects, and the oxidation of the cathode.

In the method of providing the inorganic protective film between the sealing resin and the organic EL element, the inorganic protective film is used as a cushioning material so as to relieve the stress generated inside the sealing resin thickened by the film sealing. It is designed to form a film. The inorganic protective film is formed between the sealing resin and the organic EL element so as to suppress the life reduction of the organic EL element due to contact with moisture or oxygen in the atmosphere, the occurrence of dark spot defects, and the oxidation of the cathode. Has been done.

[0008]

However, when manufacturing an electro-optical device by top emission in which the light of the light emitting layer is extracted from the side of the sealing substrate, the sealing substrate is distorted in the can sealing in order to seal the organic EL element with the organic EL element. The distance between the stop substrates varies, the image is distorted, and interference fringes are easily generated, and it is necessary to maintain the distance between the organic EL element and the sealing substrate with high accuracy, and thus the electro-optical device can be easily manufactured. There was a problem that I could not.

Further, in the method of film sealing, in order to achieve a long life of the organic EL element and prevention of defect generation, the sealing resin is thickened so that moisture and oxygen in the atmosphere do not pass through the sealing resin. It is necessary to form a film. However, there is a problem that the sealing resin is distorted by the stress generated inside the thickened sealing resin, and a part of the organic EL element is damaged, and the electro-optical device can be easily manufactured. There was a problem that I could not.

Further, according to the method of providing the inorganic protective film between the sealing resin and the organic EL element, the stress in the sealing resin is relieved, but an interface is formed when the inorganic protective film is provided, and the interface is formed. As a result, the transmittance decreases, the organic EL light is blocked, and the display becomes dark. To achieve the same brightness, power consumption increases and the life of the electro-optical device tends to be shortened.

The present invention has been made in consideration of such circumstances, and an object thereof is to suppress the stress in the sealing resin due to film sealing so that the electro-optical device can be easily manufactured and the organic optical device can be easily manufactured. An object of the present invention is to provide an electro-optical device capable of suppressing contact between an EL element and moisture or oxygen in the atmosphere, prolonging the life of the electro-optical device and suppressing occurrence of dark spot defects.

[0012]

In order to achieve the above object, the present invention has the following constitutions. The electro-optical device of the present invention is an electro-optical device having a circuit board on which an electric circuit is provided and a sealing substrate facing the circuit board, and the circuit board and the sealing substrate face each other. It is characterized in that a concave portion is provided on a surface facing at least one of the surfaces. According to the electro-optical device, since the concave portion is provided on the surface facing at least one of the facing surfaces of the circuit board and the sealing substrate, the desiccant or the oxygen absorber is provided on the sealing substrate. Can be easily provided.

An electro-optical device according to the present invention is the electro-optical device described above, characterized in that a desiccant or an oxygen scavenger is provided in the recess. According to the electro-optical device, since the desiccant or the oxygen absorber is provided in the recess, contact between the phosphor and moisture or oxygen in the atmosphere is prevented, and the phosphor and moisture or oxygen in the atmosphere are prevented. The shielding efficiency with respect to the phosphor is improved, and the life of the phosphor can be extended.

Further, when moisture or oxygen in the atmosphere enters the inside of the encapsulant through the adhesive from the side of the adhesive, the invaded moisture or oxygen dries in the recess of the encapsulation substrate. The encapsulant and the laminated structure which are absorbed by the agent or the oxygen scavenger and sandwiched between the circuit board and the encapsulation substrate can always be maintained in a dry state and an oxygen-free state.

Further, since the sealant and the laminated structure sandwiched between the circuit board and the sealing substrate are always in a dry state and an oxygen-free state, moisture and oxygen due to the thickening of the sealant are prevented. It is not necessary to consider the prevention of permeation, and the thickness of the sealant is
The sealant can be formed to have a predetermined thickness that does not generate stress. Further, the electro-optical device can be easily manufactured without damaging a part of the laminated structure due to the stress generated in the sealing resin.

Further, since the encapsulant is formed to have a predetermined thickness so that stress is not generated in the encapsulant, it is not necessary to coat the laminated structure with the inorganic protective film. As a result, no interface is formed when the inorganic protective film is provided, and the interface does not reduce the transmittance. In other words, it is possible to manufacture an electro-optical device that emits light satisfactorily without the phenomenon that the display becomes dark due to the blocking of the organic EL light.

The electro-optical device of the present invention is the electro-optical device described above, wherein a sealant is provided between the circuit board and the sealing substrate, and the thickness of the sealant is Is 10 μm
It is characterized in that it is provided as follows. According to this electro-optical device, since the thickness of the encapsulant is set to 10 μm or less, the effect of preventing contact between the phosphor and moisture or oxygen in the atmosphere is promoted, and Further, the efficiency of shielding against moisture or oxygen in the atmosphere is promoted, and the life of the phosphor can be extended.

Further, the electro-optical device of the present invention is an electro-optical device having a circuit board on which an electric circuit is provided, and a sealing substrate which is connected so as to face the circuit board. It is characterized in that a desiccant or an oxygen scavenger is mixed in the adhesive for adhering to the stop substrate. According to the electro-optical device, since the desiccant or the oxygen absorber is mixed in the adhesive agent for adhering the circuit board and the sealing substrate, contact between the phosphor and moisture or oxygen in the atmosphere Is prevented, the efficiency of shielding the phosphor from moisture or oxygen in the atmosphere is improved, and the life of the phosphor can be extended.

Further, when moisture or oxygen in the atmosphere enters the inside of the sealant from the side of the adhesive through the adhesive, the desiccant or oxygen scavenger contained in the adhesive causes moisture or oxygen in the atmosphere to disappear. It is possible to absorb oxygen and suppress entry of moisture or oxygen into the sealant. That is, the sealant and the laminated structure sandwiched between the circuit board and the sealing substrate are
It can be kept dry and anoxic at all times.

Further, since the sealant and the laminated structure sandwiched between the circuit board and the sealing substrate are always in a dry state and in an oxygen-free state, moisture and oxygen due to the thickening of the sealant can be prevented. It is not necessary to consider the prevention of permeation, and the thickness of the sealant is
The sealant can be formed to have a predetermined thickness that does not generate stress. Further, the electro-optical device can be easily manufactured without damaging a part of the laminated structure due to the stress generated in the sealing resin.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are diagrams showing an electro-optical device according to an embodiment of the present invention.
FIG. 1 is a side sectional view showing a main part of the electro-optical device. Figure 2
FIG. 6 is a perspective view showing a method of assembling the electro-optical device.

The electro-optical device 1 according to the present embodiment has a circuit board 2 provided with an electric circuit and a sealing substrate 3 facing the circuit board 2 and connected to the electro-optical device 1. A recess 4 is provided in the substrate 3. A desiccant or oxygen absorber 5 is embedded in the recess 4.

On the circuit board 2, a hole injection electrode (anode) 11 made of ITO and a hole transport layer 12 made of TPD.
And a laminated structure 15 composed of a phosphor 13 made of Alq and a transparent cathode 14. The light emitted from the phosphor 13 is extracted to the transparent cathode 14 side.

As shown in FIG. 2, the recess 4 is formed around the periphery of the sealing substrate 3, and the recess 4 is formed when the circuit board 2 and the sealing substrate 3 are opposed to each other and connected. Circuit board 2
It is formed so as to be located outside the outer periphery of the laminated structure 15 provided in.

A sealing agent 21 is provided between the circuit board 2 and the sealing substrate 3, and the thickness of the sealing agent 21 is 10 μm or less. The sealing agent 21 is sandwiched between the circuit board 2 and the sealing substrate 3, and the sealing agent 21
The circuit board 2 and the sealing substrate 3 are bonded to each other by the adhesive 22 applied to the outer periphery of the.

In the electro-optical device 1 thus constructed, the sealing substrate 3 is provided with the recessed portion 4, and the recessed portion 4 of the sealing substrate 3 is filled with the desiccant or the oxygen absorber 5. Therefore, contact between the phosphor 13 and moisture or oxygen in the atmosphere is prevented, the efficiency of shielding the phosphor 13 from moisture or oxygen in the atmosphere is improved, and the life of the phosphor 13 can be extended.

In addition, moisture or oxygen in the atmosphere causes the adhesive 2
When entering the inside of the encapsulant 21 through the adhesive 22 from the A side on the side of 2, the invading water or oxygen is absorbed by the desiccant or the oxygen scavenger 5 provided in the recess 4 of the encapsulation substrate 3. The encapsulant 21 and the laminated structure 15 that are absorbed by and are sandwiched between the circuit board 2 and the encapsulation substrate 3 can always be maintained in a dry state and an oxygen-free state.

The encapsulant 21 and the laminated structure 15 sandwiched between the circuit board 2 and the encapsulation substrate 3 are always in a dry state and in an oxygen-free state. It is not necessary to consider prevention of moisture and oxygen permeation by
The thickness of the encapsulant 21 can be formed to a predetermined thickness so that no stress is generated in the encapsulant 21. Further, the electro-optical device 1 can be easily manufactured without damaging a part of the laminated structure 15 due to the stress generated in the sealing resin.

Further, since the encapsulant 21 is formed to have a predetermined thickness so that stress is not generated in the encapsulant 21, it is not necessary to coat the laminated structure 15 with the inorganic protective film, and thus, the inorganic structure is not required. No interface is formed when the protective film is provided, and the interface does not reduce the transmittance. That is, the electro-optical device 1 that emits light satisfactorily can be manufactured without the phenomenon that the display becomes dark due to the shielding of the organic EL light.

Further, since the sealing agent 21 is provided between the circuit board 2 and the sealing substrate 3 and the thickness of the sealing agent 21 is 10 μm or less, the phosphor 13 and The effect of preventing contact with moisture or oxygen in the atmosphere is promoted, the efficiency of shielding phosphor 13 from moisture or oxygen in the atmosphere is promoted, and life extension of phosphor 13 can be promoted.

Although the adhesive 22 is applied to the outer periphery of the sealant 21 in the above embodiment, the adhesive 22 is omitted when the sealant 21 has a sufficient adhesive force. Then, the sealant 21 may be widely applied.

In the above embodiment, the recess is provided in the sealing substrate 3, but the recess is not limited to the sealing substrate 3, and the recess may be provided in the circuit board 2.

In the above embodiment, the desiccant or oxygen absorber 5 is provided in the recess 4 of the sealing substrate 3, but
A mixture containing any one of a desiccant and an oxygen absorber may be provided in the recess of the sealing substrate 3. According to this configuration, the recess 4 of the sealing substrate 3 is provided with the admixture having one of the desiccant and the oxygen scavenger, so that the moisture or oxygen contained in the atmosphere is absorbed by the admixture. It is possible to prevent moisture or oxygen contained in the atmosphere from entering the sealing agent 21.

Next, another embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a side sectional view showing a main part of an electro-optical device according to another embodiment of the present invention. In FIG. 3, the same components as those of FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted.

In the electro-optical device 31 of the present invention, the circuit board 2 on which the electric circuit 2 is provided, the sealing substrate 3 connected to face the circuit board, the circuit board 2 and the sealing substrate 3 are connected. And an adhesive 32 for adhering to each other. Further, the circuit board 2 has a hole injection electrode (anode) 11 made of ITO.
Then, a laminated structure 15 including a hole transport layer 12 made of TPD, a phosphor 13 made of Alq, and a transparent cathode 14 is formed. The light emitted from the phosphor 13 is extracted to the transparent cathode 14 side.

A sealant 21 is provided between the circuit board 2 and the sealing substrate 3, and the thickness of the sealant 21 is 10 μm or less. The sealing agent 21 is sandwiched between the circuit board 2 and the sealing substrate 3, and the sealing agent 21
The circuit board 2 and the sealing substrate 3 are adhered to each other by the adhesive 32 applied to the outer periphery of the. The adhesive 32 has a desiccant 35 and a deoxidizer 36, and the desiccant 35 and the deoxidizer 36 prevent moisture and oxygen from entering the sealant 21. There is.

In the electro-optical device 31 thus constructed, the desiccant 35 and the deoxidizer 36 are mixed in the adhesive 32 for adhering the circuit board 2 and the sealing substrate 3, so that the phosphor is used. The contact between 13 and moisture or oxygen in the atmosphere is prevented, the efficiency of shielding phosphor 13 from moisture or oxygen in the atmosphere is improved, and the life of phosphor 13 can be extended.

In addition, moisture or oxygen in the atmosphere may cause adhesive 3
When entering the inside of the sealant 21 through the adhesive 32 from the side B on the side of 2, the desiccant 35 contained in the adhesive 32
And the oxygen absorber 36 absorbs moisture or oxygen in the atmosphere,
The penetration of moisture or oxygen into the sealant 21 is suppressed. That is, the encapsulant 21 and the laminated structure 15 sandwiched between the circuit board 2 and the encapsulation substrate 3 can always be maintained in the dry state and the oxygen-free state.

Since the sealing agent 21 and the laminated structure 15 sandwiched between the circuit board 2 and the sealing substrate 3 are always in the dry state and the oxygen-free state, the sealing agent 21 is thickened. It is not necessary to consider prevention of moisture and oxygen permeation by
The thickness of the encapsulant 21 can be formed to a predetermined thickness so that no stress is generated in the encapsulant 21. Further, the electro-optical device 31 can be easily manufactured without damaging a part of the laminated structure due to the stress generated in the sealing resin.

Further, since the sealing agent 21 is provided between the circuit board 2 and the sealing substrate 3 and the thickness of the sealing agent 21 is 10 μm or less, the phosphor 13 and The effect of preventing contact with moisture or oxygen in the atmosphere is promoted, the efficiency of shielding phosphor 13 from moisture or oxygen in the atmosphere is promoted, and the life of phosphor 13 can be extended.

Although the desiccant 35 and the oxygen scavenger 36 are provided on the adhesive 32 in the above-described embodiment, a mixture containing any one of the desiccant 35 and the oxygen scavenger 36 is bonded. It may be mixed with the agent 32. According to this structure, since the adhesive 32 is mixed with the admixture having any one of the desiccant 35 and the oxygen absorber 36, moisture or oxygen contained in the atmosphere is absorbed by the admixture. ,
It is possible to prevent moisture or oxygen contained in the atmosphere from entering the sealing agent 21.

Next, examples of electronic equipment including the electro-optical device will be described. FIG. 4 is a perspective view showing an example of a mobile phone. In FIG. 4, reference numeral 210 indicates a mobile phone main body, and reference numeral 211 indicates a display unit using the above organic EL electro-optical device.

FIG. 5 is a perspective view showing an example of a wrist watch type electronic device. In FIG. 5, reference numeral 220 indicates a watch body, and reference numeral 221 indicates a display section using the electro-optical device.

FIG. 6 is a perspective view showing an example of a portable information processing device such as a word processor and a personal computer. In FIG. 6, reference numeral 230 is an information processing apparatus, reference numeral 231 is an input unit such as a keyboard, reference numeral 232 is an information processing apparatus main body, and reference numeral 233 is a display unit using the electro-optical device.

Since the electronic equipment shown in FIGS. 4 to 6 is equipped with the electro-optical device 1 of the above-described embodiment, it is possible to realize an electronic equipment having excellent display quality and a display unit with a bright screen. .

[0046]

EXAMPLES Next, the present invention will be described concretely with reference to Examples. E
A drive circuit, an anode, a hole transport layer, a light emitting layer, and a cathode are formed on a circuit board on which the L element is formed. Grooves are formed on the outer periphery of the light emitting region of the sealing substrate by etching or sandblasting. Stick a desiccant or oxygen absorber in this groove,
Apply the sealant to the portion other than the groove. The sealing substrate and the circuit board are attached, and the sealing agent is cured. For comparison, an element was also formed on a sealing substrate without a groove, a desiccant, and an oxygen scavenger, and the light emitting region was damaged, and the life until it became dark or stopped emitting light was evaluated. As an evaluation method, a leaving test at high temperature and high humidity and an leaving test at high temperature and high oxygen concentration were conducted.

As a result, in both cases, grooves, desiccants,
The life of the sealed substrate provided with the oxygen scavenger was longer.
Next, samples in which the thickness of the sealant was changed were prepared and tested in the same manner. The thickness of the sealant is 2, 5, 8, 10, 20,
Nine kinds of 30, 60, 80 and 100 μm were used. As a result, the relationship between the sealant thickness x and the life y is y = a / x + b
(A and b are constants, which are different between the high temperature and high humidity test and the high temperature and high oxygen concentration test). Therefore, the thinner the encapsulant, the longer the life of the EL element. Also, the amount of moisture or oxygen permeation is reduced, and
It was found that the life of the oxygen absorber can be extended and the life of the oxygen absorber can be extended.

Next, a top emission type 3-inch display was produced by the can sealing method and the sealing method of the present invention, and an image was displayed. As a result, no image distortion was observed in the present invention, but in the case of the method of sealing with a can, the sealing substrate was deformed, and image distortion was seen in a concentric pattern centered on the center of the screen.

[0049]

As described above, in the electro-optical device of the present invention, the concave portion is provided on the surface facing at least one of the facing surfaces of the circuit board and the sealing substrate. The effect that the desiccant or the oxygen absorber can be easily provided on the sealing substrate is obtained.

Further, since the desiccant or oxygen scavenger is provided in the recess, contact between the phosphor and moisture or oxygen in the atmosphere is prevented, and the phosphor is shielded from moisture or oxygen in the atmosphere. The efficiency is improved and the life of the phosphor can be extended.

When moisture or oxygen in the atmosphere enters the inside of the encapsulant through the adhesive from the side of the adhesive, the infiltrated moisture or oxygen dries in the recess of the encapsulation substrate. The encapsulant and the laminated structure which are absorbed by the agent and sandwiched between the circuit board and the encapsulation substrate have the effect of being able to be constantly maintained in the dry state and the oxygen-free state.

Further, the sealant and the laminated structure sandwiched between the circuit board and the sealing substrate are always in a dry state and an oxygen-free state. It is not necessary to consider the prevention of permeation, and the thickness of the sealant is
It is possible to obtain the effect that the sealing agent can be formed to have a predetermined thickness so that no stress is generated. In addition, a part of the laminated structure is not damaged by the stress generated in the sealing resin, and the effect of easily manufacturing the electro-optical device can be obtained.

Further, since the encapsulant is formed to have a predetermined thickness so that stress is not generated in the encapsulant, it is not necessary to coat the laminated structure with the inorganic protective film. As a result, no interface is formed when the inorganic protective film is provided, and the interface does not reduce the transmittance. That is, it is possible to obtain an effect that an electro-optical device that emits light satisfactorily can be manufactured without the phenomenon that the display becomes dark due to the blocking of the organic EL light.

Further, since the sealing agent is provided so as to have a thickness of 10 μm or less, the effect of preventing contact between the phosphor and moisture or oxygen in the atmosphere is promoted, and the phosphor and the atmosphere It is possible to obtain the effect that the efficiency of shielding from the water or oxygen is promoted, and the life extension of the phosphor can be promoted.

Further, since the desiccant or the oxygen scavenger is mixed in the adhesive agent for adhering the circuit board and the sealing substrate, contact between the phosphor and moisture or oxygen in the atmosphere is prevented. The effect of improving the shielding efficiency between the phosphor and moisture or oxygen in the atmosphere and extending the life of the phosphor can be obtained.

Further, when moisture or oxygen in the atmosphere penetrates into the sealant from the side of the adhesive through the adhesive, the desiccant or oxygen scavenger contained in the adhesive causes moisture or oxygen in the atmosphere to disappear. The effect of absorbing oxygen and suppressing entry of moisture or oxygen into the sealant is obtained. That is, the encapsulant and the laminated structure sandwiched between the circuit board and the encapsulation substrate can be maintained in a dry state and an oxygen-free state at all times.

Further, the sealant and the laminated structure sandwiched between the circuit board and the sealing substrate are always in a dry state and in an oxygen-free state. It is not necessary to consider the prevention of permeation, and the thickness of the sealant is
It is possible to obtain the effect that the sealing agent can be formed to have a predetermined thickness so that no stress is generated. In addition, the electro-optical device can be easily manufactured without damaging a part of the laminated structure due to the stress generated in the sealing resin.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a main part of an electro-optical device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an assembling method of the electro-optical device according to the embodiment of the invention.

FIG. 3 is a side sectional view showing a main part of an electro-optical device according to another embodiment of the present invention.

FIG. 4 is a diagram showing an electronic device on which the electro-optical device of the invention is mounted.

FIG. 5 is a diagram showing an electronic device on which the electro-optical device of the invention is mounted.

FIG. 6 is a diagram showing an electronic device equipped with the electro-optical device of the invention.

[Explanation of symbols]

1 Electro-optical device 2 circuit board 3 Sealing substrate 4 recess 5 desiccant or oxygen absorber 21 Sealant 32 adhesive 35 desiccant 36 oxygen absorber

Claims (5)

[Claims] 1. An electro-optical device comprising: a circuit board provided with an electric circuit; and a sealing substrate facing and connected to the circuit board, wherein the circuit board and the sealing substrate have opposite surfaces. An electro-optical device characterized in that a concave portion is provided on a surface facing at least one of them. 2. The electro-optical device according to claim 1, wherein the concave portion is provided with a desiccant or an oxygen scavenger. 3. The electro-optical device according to claim 1, wherein a sealant is provided between the circuit board and the sealing substrate, and the thickness of the sealant is 10 μm or less. An electro-optical device characterized by being provided as follows. 4. An electro-optical device having a circuit board provided with an electric circuit and a sealing substrate which is connected to face the circuit board. An adhesive for bonding the circuit board and the sealing substrate. An electro-optical device in which a desiccant or an oxygen absorber is mixed. 5. An electronic apparatus comprising the electro-optical device according to claim 1. Description: