JP2013012426A - Organic el panel and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL panel which improves the heat radiation performance and the strength and suppresses the occurrence of display failures, and to provide a manufacturing method of the organic EL panel.SOLUTION: An organic EL panel is formed by forming an organic EL element, holding at least an organic light emitting layer between both electrodes 2, 4, on a support substrate 1 and disposing a sealing substrate 5 hermetically covering the organic EL element on the support substrate 1 through an adhesive 6 containing a spacer 6a. A filler 7 containing a heat radiation filler 7a is arranged on a surface of the sealing substrate 5 which faces the organic EL element. The filler 7 has the height T2 at the time of the arrangement which is lower than the height T1 of the adhesive 6 at the time of the arrangement and is higher than the diameter a1 of the spacer 6a, and the heat radiation filler 7a has the diameter a2 smaller than the diameter a1 of the spacer 6a. The sealing substrate 5 and the support substrate are pressurized and bonded after the filler 7 is disposed.

Description

  The present invention relates to an organic EL panel in which an organic EL (Electro-Luminescence) element formed by sandwiching at least an organic light emitting layer between both electrodes is formed on a support substrate, and in particular, a filler is disposed in an airtight space. The present invention relates to an organic EL panel and a method for manufacturing the same.

  In recent years, organic EL panels using organic EL elements have been spotlighted as self-luminous devices, and display applications have less viewing angle dependency than liquid crystal display devices, have high contrast ratios, and can be thinned. Due to the advantages such as, flat screen televisions using organic EL panels have recently been put on the market.

  In recent years, organic EL panels have begun to be put on the market as lighting devices, and development for lighting applications is actively performed. In particular, an organic EL panel for use in lighting is one of the development items in which a heat dissipation technique accompanying an increase in luminance is an important development item.

  As disclosed in, for example, Patent Documents 1 and 2 as heat dissipation techniques, an invention is disclosed in which a filler is filled in an airtight space between a support substrate and a sealing substrate. By filling the filler, in addition to heat dissipation, it is also possible to suppress display defects due to contact between the support substrate and the sealing substrate that are bent with an increase in size.

JP 2004-103534 A Japanese Patent Publication No. 2008-102694

  However, in the above-described configuration, when pressure is applied to the organic EL element under various conditions such as temperature change or when pressure is applied to both substrates when the support substrate and the sealing substrate are bonded, There is a problem in that display defects may occur due to physical damage to the organic EL element due to the filler, and there is room for further improvement for heat dissipation and strength improvement of the organic EL panel.

  The present invention has been made in view of this problem, and provides an organic EL panel capable of improving heat dissipation and strength, and capable of suppressing the occurrence of display defects, and a method for manufacturing the same. is there.

In order to solve the above problems, the present invention forms an organic EL element having at least an organic light emitting layer between both electrodes on a supporting substrate, and a sealing substrate that hermetically covers the organic EL element with a spacer. An organic EL panel disposed on the support substrate via an adhesive containing,
A filler containing a heat dissipating filler is disposed on the surface of the sealing substrate facing the organic EL element,
The height of the filler is lower than the height of the adhesive when disposed, and higher than the diameter of the spacer, and the heat dissipating filler is smaller than the diameter of the spacer,
The sealing substrate and the support substrate are characterized by being pressed and bonded after the filler is disposed.

  Further, the volume of the protruding portion disposed higher than the diameter of the spacer at the time of disposing the filler is determined based on the capacity of the designed airtight space determined based on the diameter of the spacer. The volume of the non-projecting portion is larger than the design remaining capacity excluding the volume of the non-projecting portion disposed below the diameter of the spacer at the time, and the volume of the limit airtight space determined based on the diameter of the spacer +10 μm It is smaller than the limit remaining capacity excluding.

  Further, the sealing substrate includes a hygroscopic agent disposed around the filler, and a partition portion is formed so as to be positioned between the filler and the hygroscopic agent. .

  In addition, the partition portion is convex and is formed lower than the interval between the sealing substrate and the support substrate after bonding.

  In addition, the partition portion is formed to be lower than a maximum deflection amount of the partition portion forming portion of the sealing substrate than an interval between the sealing substrate and the support substrate after bonding.

  Further, the sealing substrate has a surface roughness of a surface facing the organic EL element of 1 μm or more.

In order to solve the above problems, the present invention forms an organic EL element having at least an organic light emitting layer between both electrodes on a supporting substrate, and a sealing substrate that hermetically covers the organic EL element with a spacer. A method for producing an organic EL panel, which is disposed on the support substrate via an adhesive containing,
Disposing a filler containing a heat dissipating filler on the surface of the sealing substrate facing the organic EL element,
The filler is disposed such that the height when disposed is lower than the height when disposed and the diameter of the spacer is larger than the diameter of the spacer. Smaller than the diameter of
The sealing substrate and the supporting substrate are pressed and bonded after the filler is disposed.

  Further, the volume of the projecting portion disposed higher than the diameter of the spacer at the time of disposing the filler is determined based on the capacity of the designed airtight space determined based on the diameter of the spacer. The volume of the non-projecting portion is larger than the design remaining capacity excluding the volume of the non-projecting portion disposed below the diameter of the spacer at the time, and the volume of the limit airtight space determined based on the diameter of the spacer +10 μm The filler is disposed so as to be smaller than the limit remaining capacity excluding.

  The present invention relates to an organic EL panel in which an organic EL element having at least an organic light emitting layer sandwiched between both electrodes is formed on a support substrate, and in particular, an organic EL panel in which a filler is disposed in an airtight space and its The present invention relates to a manufacturing method, which can improve heat dissipation and strength, and can suppress the occurrence of display defects.

Sectional drawing which shows the organic electroluminescent panel which is embodiment of this invention. The figure which shows the manufacturing method of an organic electroluminescent panel same as the above. The top view which shows the sealing substrate of an organic electroluminescent panel same as the above. The figure which shows another example of an organic electroluminescent panel same as the above. The figure which shows another example of an organic electroluminescent panel same as the above. The simplification figure which shows a part of sealing substrate in an organic electroluminescent panel same as the above.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an organic EL panel according to an embodiment of the present invention. In the organic EL panel, a light emitting part (organic EL element) including a transparent electrode (anode) 2, a functional layer 3, and a back electrode (cathode) 4 is formed on a support substrate 1, and a sealing substrate is formed on the support substrate 1. 5 is disposed via an adhesive 6. A filler 7 is disposed on the surface of the sealing substrate 5 facing the light emitting portion.

  The support substrate 1 is a rectangular substrate made of, for example, a light transmissive glass substrate.

  The transparent electrode 2 is made of a transparent conductive material such as ITO, IZO (registered trademark), ZnO, AZO, GZO, etc., and is formed in a layered manner by means such as sputtering, vacuum deposition, spin coating, and inkjet. Then, it is patterned into a desired shape by a photolithography method. On the transparent electrode 2, in order to reduce wiring resistance, aluminum (Al), molybdenum (Mo), titanium (Ti), silver (Ag), copper (Cu), chromium (Cr), nickel (Ni) An auxiliary electrode made of a single layer or a laminate of a low-resistance metal material such as these or an alloy thereof may be partially formed. Further, an insulating film made of an inorganic material or a polymer material for preventing a short circuit may be formed on the end portion of the transparent electrode 2. The insulating film is formed into a layer by means of a sputtering method, a vacuum deposition method, a spin coating method, an ink jet method or the like, and then patterned into a desired shape by a photolithography method.

  The functional layer 3 has at least an organic light emitting layer, and includes, for example, a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and an electron injection layer, and each layer is formed by means such as a vacuum deposition method. It is formed.

  The back electrode 4 is made of, for example, aluminum (Al), calcium (Ca), molybdenum (Mo), titanium (Ti), silver (Ag), gold (Au), copper (Cu), chromium (Cr), nickel (Ni). It is made of a low-resistance metal conductive material such as magnesium (Mg), a transparent conductive material such as IZO (registered trademark), ZnO, AZO, or GZO, or an alloy thereof, and by means such as vacuum deposition or sputtering. It is formed in layers. The portion where the transparent electrode 2 and the back electrode 4 face each other and sandwich the functional layer 3 is the light emitting portion.

  The sealing substrate 5 is made of a rectangular substrate made of a light-transmitting glass substrate, for example, like the support substrate 1, and an ultraviolet curable adhesive 6 containing a spacer 6 a is applied to the peripheral portion and this adhesion is performed. By being adhered onto the support substrate 1 via the agent 6, an airtight space for accommodating the light emitting portion together with the support substrate 1 is formed. The sealing substrate 5 is coated with a filler 7 on the surface facing the light emitting portion. The sealing substrate 5 may be made of a metal material.

  The filler 7 is made of a gelling agent having a viscosity of about 120 Pa · s including the heat dissipating filler 7 a, and is applied and disposed on the surface of the sealing substrate 5 facing the light emitting portion. The heat dissipating filler 7a serves as a medium for releasing the heat generated from the light emitting part and transmitted through the moisture absorbent 9 to the outside from the sealing substrate 5, and does not contain any solvent or moisture, such as alumina, silica, silicon Or oxides or nitrides of iron, zinc, copper, silver, or the like covered with an insulating resin. The diameter of the heat dissipating filler 7 a is, for example, 15 to 20 μm, but may be smaller or larger as long as it is smaller than the diameter of the spacer 6 a of the adhesive 6.

Furthermore, the characteristic part in this embodiment is described. FIG. 2 shows an application process of the filler 7 to the sealing substrate 5 and an adhesion process between the support substrate 1 and the sealing substrate 5 in the manufacturing method of the organic EL panel.
First, the adhesive 6 containing the spacer 6a is applied to the peripheral portion of the surface of the sealing substrate 5 facing the light emitting portion by means such as a dispenser (see FIG. 2A). At this time, the height when applying (disposing) the adhesive 6 is T1.
Next, a filler 7 containing a heat dissipating filler 7a is applied to the inside of the application region of the adhesive 6 on the surface facing the light emitting portion of the sealing substrate 5 by means such as a dispenser (FIG. 2 (b) and (See FIG. 3). At this time, the height T2 at the time of application (disposition) of the filler 7 is lower than the height T1 at the time of application of the adhesive 6 (T2 <T1), and from the diameter a1 of the spacer 6a of the adhesive 6 The filler 7 is applied so as to be slightly higher (T2> a1). In addition, the filler 7 is applied in a line shape having a predetermined length d and width w at the time of application, and is not applied to the entire surface of the sealing substrate 5. A region (hereinafter also referred to as an interval portion) 5a where no coating is applied is provided. Further, in the volume S (S = T2 · d · w) of the applied filler 7, a portion higher than the diameter a1 of the spacer 6a obtained by (T2−a1) · d · w (hereinafter referred to as a protrusion) The volume S1 of 7b (S1 = (T2-a1) · d · w) is calculated from the capacity of the design hermetic space determined by x · y · a1 based on the diameter a1 of the spacer 6a (x, y Indicates the vertical and horizontal lengths of the airtight space, and more specifically indicates the vertical and horizontal lengths of the space in which the filler 7 is filled when the substrates 1 and 5 are bonded to each other in the airtight space). Among these, the design remaining capacity S2 (S2 = (x · y · a1) − ( a1 · d · w)) and the diameter a1 + 10 μm of the spacer 6a, x · A limit remaining capacity S3 (S3 = (x · y · (a1 + 10 μm)) − (a1 · d · w) obtained by subtracting the volume of the non-projecting portion 7c from the capacity of the limit airtight space determined by (a1 + 10 μm) The filler 7 is applied so as to satisfy the following relationship:
S2 <S1 <S3
That is,
(X.y.a1)-(a1.d.w) <(T2-a1) .d.w <(x.y. (a1 + 10 .mu.m))-(a1.d.w)
In addition, as the heat dissipating filler 7a contained in the filler 7, a filler having a diameter a2 smaller than the diameter a1 of the spacer 6a is used. The diameter a1 of the spacer 6a depends on an interval T3 between the substrates 1 and 5 after bonding, which will be described later. However, if the interval T3 is high, moisture easily passes through the adhesive 6 and the sealing performance is deteriorated. The diameter a1 is desirably small, and the diameter a2 of the heat dissipating filler 7a is further smaller than this.
Next, the sealing substrate 5 to which the adhesive 6 and the filler 7 are applied as described above and the support substrate 1 on which the light-emitting portion is formed are overlapped (see FIG. 2C), and both the substrates 1, 5 are overlapped. After applying a predetermined pressure in a direction perpendicular to the plane of the substrate, the adhesive 6 is cured by irradiating UV, and the substrates 1 and 5 are bonded to seal the light emitting portion (see FIG. 2D). ). At this time, the adhesive 6 is first crushed by pressurization after coming into contact with the support substrate 1, and then the filler 7 is brought into contact with the support substrate 1 (including the light emitting part), and further, both substrates 1, The filler 7 pushes and spreads in the horizontal direction with respect to the plane of 5 to fill the space portion 5a and cover the light emitting portion. As a result of applying the filler 7 so as to satisfy the above formula, the application volume S of the filler 7 becomes larger than the designed capacity of the airtight space, and the application volume S of the filler 7 and the viscosity of the filler 7 are increased. Thus, the substrates 1 and 5 are not close to the diameter a1 of the spacer 6a, and the distance T3 between the substrates 1 and 5 after bonding is higher than the diameter a1 of the spacer 6a.

In the present embodiment, the heat dissipation and the strength can be improved by disposing the filler 7 including the heat dissipating filler 7a on the surface of the sealing substrate 5 facing the light emitting portion. Furthermore, due to the above-described features, the height T2 when the filler 7 is applied is lower than the height T1 when the adhesive 6 is applied, so that the adhesive 6 first contacts when both substrates 1 and 5 are pressed. Therefore, it is possible to prevent the filler 7 from getting over the adhesive 6 and leaking out of the airtight space to cover the wiring and terminals of the light emitting portion and cause a display failure due to poor connection.
Furthermore, by making the height T2 at the time of applying the filler 7 slightly higher than the diameter 6a of the spacer 6a of the adhesive 6, the filler 7 is spread and spread when the substrates 1 and 5 are pressed, and the light emitting part is It can be covered without a gap, and heat dissipation and strength can be improved.
Furthermore, by making the diameter a2 of the heat dissipating filler 7a contained in the filler 7 smaller than the diameter a1 of the spacer 6a, the filler 7 applies stress to the light emitting part when the filler 7 is expanded or when the temperature changes. In particular, it is possible to suppress physical damage to the light emitting portion by the heat dissipating filler 7a, and to suppress the occurrence of display defects.
If the distance T3 between the substrates 1 and 5 is too large with respect to the diameter a1 of the spacer 6a, the moisture can easily pass through the adhesive 6 as described above. By making the coating volume within the range of the above formula, it is possible to realize both filling without gaps and sealing performance. In addition, when the viscosity of the filler 7 is too low, the filler 7 spreads too much at the time of pressurization, and when the viscosity is too high, the filler 7 spreads to such an extent that the filler 7 fills the gap portion 5a even when pressurized. Therefore, it is desirable that the filler 7 has a viscosity of 200 pa · s or less and a kinematic viscosity of about 110000 cSt ± 10000.

  In addition, you may apply | coat the moisture absorbent for adsorb | sucking the water | moisture content which penetrate | invaded in airtight space to the surface facing the said light emission part of the sealing substrate 5. FIG. Specifically, as shown in FIG. 4, a hygroscopic agent 8 is applied between the adhesive 6 and the filler 7. The hygroscopic agent 8 is formed into a cream or paste by mixing an inorganic material such as activated alumina, molecular sieves, calcium oxide or barium oxide having a hygroscopic action to adsorb moisture chemically or physically and a resin material. The When applying the hygroscopic agent 8 in the present invention, the calculation is performed by excluding the width of the application region of the hygroscopic agent 8 from x and y when calculating the airtight space at the time of design.

なお、αは係数（−）であり、Ｌは荷重（Ｎ）であり、ａは封止基板５の単辺長さ（ｍ）（接着剤６の塗布領域を除く）であり、Ｄは封止基板５の剛性（Ｎ・ｍ）を示す。
さらに、封止基板５の中央部に掛かる荷重Ｌは、以下の数式２で示される。

したがって、仕切り部５ｂ形成個所の最大撓み量Δｗ_２（ｍ）は以下の数式３に近似する。

なお、ｘ_１は、封止基板５の中央部から仕切り部５ｂまでの長さを示す。 Further, when the filler 7 and the hygroscopic agent 8 are respectively applied to the sealing substrate 5, the filler 7 and the hygroscopic agent 8 are mixed to cause a chemical reaction or partially expand. The light emitting part may be damaged to cause a display defect, or the functions as the filler 7 and the hygroscopic agent 8 may be impaired, and the product life to be compensated may not be obtained.
On the other hand, as shown in FIG. 5, the convex partition part 5b is formed on the surface of the sealing substrate 5 facing the light emitting part so as to be positioned between the filler 7 and the hygroscopic agent 8. Further, the mixing of the filler 7 and the hygroscopic agent 8 can be suppressed, and the reliability can be improved. The partition portion 5b can be formed by etching, frosting, blasting, or a combination thereof.
Further, the partition portion 5b is formed such that its height T4 is lower than the interval T3 between the two substrates 1 and 5 after bonding, and more desirably, the partition portion 5b formation portion of the sealing substrate 5 due to temperature change or the like. It is formed lower than the maximum deflection amount Δw ₂ part (T4 <T3-Δw ₂ ). This is to prevent a display defect from occurring by preventing contact between the partition portion 5b and the light emitting portion (including wirings). The maximum amount of deflection Δw _{2 at the} portion where the partition portion 5b is formed is an approximate value represented by the following Expression 3.
FIG. 6 illustrates a half of the sealing substrate 5, and the illustrated boundary indicates the central portion. Further, in order to simplify the description, the filler 7 and the hygroscopic agent 8 are omitted. As shown in FIG. 6, the maximum deflection amount Δw ₁ (m) of the central portion of the sealing substrate 5 is approximated by Equation 1 below.

Α is a coefficient (−), L is a load (N), a is a single side length (m) of the sealing substrate 5 (excluding an application region of the adhesive 6), and D is a seal. The rigidity (N · m) of the stationary substrate 5 is shown.
Further, the load L applied to the central portion of the sealing substrate 5 is expressed by the following formula 2.

Therefore, the maximum amount of deflection Δw ₂ (m) at the portion where the partition portion 5b is formed approximates the following Equation 3.

Incidentally, x ₁ denotes the length from the central portion of the sealing substrate 5 to the partition portion 5b.

If the viscosity of the filler 7 is low, the surface of the sealing substrate 5 facing the light emitting portion is further roughened by blasting or frosting so that the surface roughness Ra is 1 μm or more. Excessive spread of the agent 7 can be suppressed.
Moreover, it can avoid that the light emission area | region of the said light emission part and the partition part 5b contact by making the application | coating area | region of the filler 7 wider than the said light emission part.

  Further, in the present embodiment, the sealing substrate 5 has a flat plate shape, but the sealing substrate 5 is formed in a concave shape by forming a supporting portion protruding in the direction of the supporting substrate 1 at the peripheral portion, and an adhesive is provided on the supporting portion. 6 may be applied. When the concave sealing substrate 5 is used, the “height T1 when the adhesive 6 is applied (height when the adhesive is disposed)” in the present invention is equal to the height when the actual adhesive 6 is applied. The height of the support portion is added, and “the diameter a1 of the spacer 6a (spacer diameter)” is obtained by adding the height of the support portion to the actual diameter of the spacer 6a.

  The specific effects of the present invention will be described below with further examples.

An example is the organic EL panel shown in the above-described embodiment. First, ITO having a film thickness of 300 nm is formed on the support substrate 1 as the transparent electrode 2 by a sputtering method, and is patterned into a desired shape by a photolithography method. . Next, Al was formed with a film thickness of 500 nm by sputtering as an auxiliary electrode for reducing wiring resistance, and was patterned into a desired shape by photolithography. Next, polyimide is formed as an insulating film with a film thickness of 1 μm by spin coating so as to partially cover the transparent electrode 2 and the auxiliary electrode, and patterned into a desired shape by photolithography, and then at 250 ° C. for 1 hour. The insulating film was baked by heat treatment. Next, a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and an electron injection layer are formed as a functional layer 3 on the transparent electrode 2 in this order by a vacuum deposition method. Al was formed with a film thickness of 100 nm by a vacuum deposition method, and a light emitting portion was provided.
Further, a flat soda glass having a thickness of 0.5 mm was prepared as the sealing substrate 5, and an ultraviolet curable adhesive 6 containing 1 wt% of a spacer 6 a having a diameter of 40 μm was applied to the peripheral portion so as to cover the light emitting portion later. Height T1 at the time of application | coating of the adhesive agent 6 was 200 micrometers-300 micrometers. Thereafter, the sealing substrate 5 is transported to a glove box under a nitrogen environment, and a chemical moisture absorbent based on CaO is used as the moisture absorbent 8 and two sides inside the adhesive 6 on the surface facing the light emitting portion of the sealing substrate 5. The surface of the sealing substrate 5 facing the light emitting portion is coated with a filler, which includes a heat dissipating filler 7a made of alumina having a diameter of 10 to 20 μm and a gelling agent having a viscosity of about 120 Pa · s. It applied with the dispenser to the center area | region enclosed with the adhesive agent 6 and the hygroscopic agent 8. The height T2 when the filler 7 was applied was 80 μm to 100 μm.
Then, the support substrate 1 on which the light emitting part is formed and the sealing substrate 5 coated with the adhesive 6, the filler 7, and the hygroscopic agent 8 are overlapped, and both are adhered by applying 10 J of pressure and ultraviolet irradiation. An organic EL panel was prepared. The organic EL panel had an outer size of 48 mm × 50 mm and a pixel (light emitting portion) size of 45 mm × 45 mm.

(Comparative Example 1)
As Comparative Example 1, the height T1 at the time of application of the adhesive 6 is 200 μm to 300 μm, which is the same as that in Example 1, and after the moisture absorbent 8 is applied as in Example 1, it is made of alumina having a diameter of 40-60 μm. A filler 7 including a heat dissipating filler 7a and made of a gelling agent having a viscosity of about 140 Pa · s is dispensed in a central region surrounded by the adhesive 6 and the hygroscopic agent 8 on the surface facing the light emitting portion of the sealing substrate 5 with a dispenser. Applied. In the comparative example 1, the height T2 when the filler 7 was applied was set to 200 μm to 300 μm so as to be substantially the same as the height T1 when the adhesive 6 was applied. The adhesive 6 is the same as in Example 1, and the spacer contained has a diameter of 40 μm.
In addition, the organic EL panel as Comparative Example 1 was prepared in the same manner as Example 1 except for the above.

(Evaluation method)
As an evaluation method of Example 1 and Comparative Example 1, first, it was confirmed by appearance observation whether there was leakage of the filler 7 and contact with the hygroscopic agent 8.
Further, a heat cycle test in which light emission was driven at a luminance of 3000 cd / m ² under a temperature environment of −40 ° C./80° C. was performed for 1000 hours. This is to evaluate whether or not a display defect is caused by causing damage due to a change in the stress applied to the light emitting part by the filler 7 due to expansion and contraction accompanying a change in air pressure of the air contained in the airtight space due to a temperature change. Is.
Similarly, a low-temperature operation test in which light emission was driven at a luminance of 3000 cd / m ² under a low temperature environment of −40 ° C. was performed for 1000 hours. This evaluates whether or not the light emitting portion is damaged by the filler 7 and causes a display defect under a low temperature environment in which the stress applied to the light emitting portion is larger than that at room temperature as described above.
Further, a high temperature environment of 80 ° C. for accelerating the display defect for the purpose of confirming at an early stage whether or not the light emitting part is damaged by the filler 7 due to the pressure applied when the two substrates are overlapped, and the display defect occurs. A high temperature operation test in which light emission was driven at a luminance of 3000 cd / m ² was performed for 1000 hours.

上表１は、前述の充填剤７の漏れ及び吸湿剤８への接触の有無、ヒートサイクル試験、低温動作試験及び高温動作試験の評価結果を示すものである。比較例１においては充填剤７の漏れ、ならびに吸湿剤８への接触が確認され、また、何れの試験においても表示不良（ダークスポット）が多数発生しているのに対し、実施例１においては充填剤７の漏れ及び吸湿剤８への接触は確認されず、表示不良も生じていない。これにより、本発明を適用することで、充填剤７により放熱性や強度を向上させた構成において、充填剤７の漏れや吸湿剤８への接触が生じることがなく、また、種々の状況により発光部の面方向に圧力が掛かる場合であっても、圧力によりキズが生じて表示不良を引き起こすことを抑制することができる効果が十分に得られることは明らかである。

Table 1 above shows the evaluation results of the leakage of the filler 7 and the presence or absence of contact with the moisture absorbent 8, the heat cycle test, the low temperature operation test, and the high temperature operation test. In Comparative Example 1, leakage of the filler 7 and contact with the hygroscopic agent 8 were confirmed. In addition, in each test, many display defects (dark spots) occurred, whereas in Example 1, The leakage of the filler 7 and the contact with the hygroscopic agent 8 are not confirmed, and there is no display defect. Thereby, by applying the present invention, in the configuration in which the heat dissipation and strength are improved by the filler 7, the leakage of the filler 7 and the contact with the hygroscopic agent 8 do not occur, and depending on various situations Even when pressure is applied in the surface direction of the light emitting portion, it is clear that an effect capable of suppressing the occurrence of display defects due to scratches due to the pressure is sufficiently obtained.

  Next, specific effects when the filler 7 and the hygroscopic agent 8 are applied to the sealing substrate 5 using Examples 2 to 4 and Comparative Examples 2 and 3, and the partition portion 5b is further formed between them. Will be described.

As Example 2, 0.7 mm soda glass was used for the sealing substrate 5, and the surface was processed with an accuracy of a surface roughness Ra of 1 μm to 5 μm by frost processing. At that time, the convex partition part 5b was patterned by etching to divide the region where the filler 7 of the sealing substrate 5 was applied and the region where the hygroscopic agent 8 was applied. The height T4 of the partition portion 5b were to be lower than the maximum deflection amount [Delta] w ₂ minutes of the partition portion 5b forming point of the sealing substrate 5 than the distance T3 between the substrates 1 and 5 after bonding. After applying the filler 7 to the central region divided by the partition portion 5b on the sealing substrate 5, a chemical moisture absorbent based on CaO as the moisture absorbent 8 is applied to the outer region divided by the partition portion 5b in the same environment. It apply | coated with the dispenser. The application width of the adhesive 6 was 1.5 mm. Other than the above, an organic EL panel was prepared in the same manner as in Example 1.

  Example 3 was carried out except that the surface of the sealing substrate 5 was processed by etching, the partition part 5b was patterned by blasting, and the surface including the partition part 5b was surface-treated by etching. An organic EL panel was prepared in the same manner as in Example 2.

  As Example 4, the sealing substrate 5 is etched by forming a resist pattern having a convex shape with a width less than or equal to the etching processing accuracy, and the partition portion having a sharp shape as compared with Examples 2 and 3 is used. An organic EL panel was prepared in the same manner as in Example 2 except that 5b was formed and the surface of the sealing substrate 5 was processed by frosting so that the surface roughness Ra was 0.1 mm.

(Comparative Example 2)
As Comparative Example 2, an organic EL panel was formed in the same manner as in Example 2 except that the partition portion 5b was not formed and only the moisture absorbent 8 was applied to the sealing substrate 5 without applying the filler 7. did.
(Comparative Example 3)
As Comparative Example 3, an organic EL panel was formed in the same manner as in Example 2 except that the partition portion 5b was not formed and the filler 7 and the hygroscopic agent 8 were applied to the sealing substrate 5.

(Evaluation method)
Examples 2 to 4 and Comparative Examples 2 and 3 are created for illumination. As an evaluation method in Examples 2 to 4 and Comparative Examples 2 and 3, first, a frame frequency of 100 Hz is applied to driving for lighting, a constant current of 0.3 A is applied in the forward direction, and light is emitted at a color temperature of 2000 K at 3000 cd / m ^2. The junction temperature Tj of the light emitting part was measured.
Further, a heat cycle test in which light emission was driven at a luminance of 3000 cd / m ² under a temperature environment of −40 ° C./80° C. was performed for 1000 hours. This is because whether the stress applied to the light emitting part by the filler 7 is changed due to the expansion and contraction caused by the change in the air pressure of the air contained in the airtight space due to the temperature change, causing damage and causing poor appearance or poor display. Is to evaluate.
In addition, a high temperature and high humidity operation test in which light emission was driven at a luminance of 3000 cd / m ² in a high temperature and high humidity environment of 60 ° C./90% was performed for 1000 hours. This evaluates whether or not the hygroscopic ability of the hygroscopic agent 8 is lowered in the present invention. In addition, a vibration durability test of the in-vehicle spec was conducted. This is to evaluate whether or not the stress applied to the light emitting portion by the filler 7 is changed by the vibration due to the vibration and causes the appearance defect or the display defect.

上表２は、前述の発熱温度の評価、ヒートサイクル試験、高温高湿動作試験、振動耐久試験の評価結果をしめすものである。発熱温度の評価において、比較例２はジャンクション温度Ｔｊは室温環境下で約５２℃であり、約２７℃程度発熱していた。また、比較例２及び実施例２〜４は、ジャンクション温度Ｔｊは約２９℃で発熱は約４℃程度に抑えることができた。したがって、充填剤７を気密空間内に充填することで放熱効果が得られていることがわかる。また、ヒートサイクル試験においては、比較例２と比較例３の一部に外観あるいは点灯に不良が発生したのに対し、実施例２〜４にはいずれも不良は見られなかった。高温高湿試験においては実施例２〜４及び比較例２、３のいずれにも不良は見られなかった。振動耐久試験においては、仕切り部５ｂのない比較例３に充填剤７と吸湿剤８とが混ざり合うことによる吸湿能力の低下に伴う不良が見られた。実施例２〜４にはいずれも不良は見られなかった。これにより、本発明として封止基板５に仕切り部５ｂを形成することによって、充填剤７及び吸湿剤８の能力を低下させることなく、信頼性を向上させることができる効果が十分に得られることは明らかである。

Table 2 above shows the evaluation results of the above-described evaluation of heat generation temperature, heat cycle test, high temperature and high humidity operation test, and vibration durability test. In the evaluation of the heat generation temperature, in Comparative Example 2, the junction temperature Tj was about 52 ° C. in a room temperature environment, and the heat generation was about 27 ° C. In Comparative Example 2 and Examples 2 to 4, the junction temperature Tj was about 29 ° C., and the heat generation could be suppressed to about 4 ° C. Therefore, it turns out that the heat dissipation effect is acquired by filling the filler 7 in airtight space. Further, in the heat cycle test, defects in appearance or lighting occurred in some of Comparative Examples 2 and 3, whereas no defects were found in Examples 2 to 4. In the high temperature and high humidity test, no defect was found in any of Examples 2 to 4 and Comparative Examples 2 and 3. In the vibration endurance test, a defect associated with a decrease in moisture absorption capability due to the mixing of the filler 7 and the moisture absorbent 8 with the comparative example 3 without the partition portion 5b was observed. In Examples 2 to 4, no defect was found. Thereby, the effect which can improve reliability is fully acquired, without reducing the capability of the filler 7 and the hygroscopic agent 8, by forming the partition part 5b in the sealing substrate 5 as this invention. Is clear.

  The present invention relates to an organic EL panel in which a light emitting portion having at least an organic light emitting layer sandwiched between both electrodes is formed on a support substrate, and is particularly suitable for an organic EL panel in which a filler is disposed in an airtight space. . The present invention can be applied regardless of whether it is for display or illumination, and can also be applied to an organic EL panel of a segment type display type or a dot matrix type display type.

DESCRIPTION OF SYMBOLS 1 Support substrate 2 Transparent electrode 3 Functional layer 4 Back electrode 5 Sealing substrate 5a Space | interval part 5b Partition part 6 Adhesive 6a Spacer 7 Filler 7a Heat-radiating filler 8 Hygroscopic agent

Claims (8)

An organic EL element having at least an organic light emitting layer sandwiched between both electrodes is formed on a support substrate, and a sealing substrate that hermetically covers the organic EL element is formed on the support substrate through an adhesive including a spacer. An organic EL panel that is arranged,
A filler containing a heat dissipating filler is disposed on the surface of the sealing substrate facing the organic EL element,
The height of the filler is lower than the height of the adhesive when disposed, and higher than the diameter of the spacer, and the heat dissipating filler is smaller than the diameter of the spacer,
The organic EL panel, wherein the sealing substrate and the support substrate are pressed and bonded after the filler is disposed. The volume of the protrusion disposed higher than the diameter of the spacer at the time of disposing the filler is determined based on the capacity of the design hermetic space determined based on the diameter of the spacer at the time of disposing the filler. It is larger than the design remaining capacity excluding the volume of the non-projecting part arranged below the diameter of the spacer, and the volume of the non-projecting part is removed from the capacity of the limit airtight space determined based on the diameter of the spacer +10 μm. The organic EL panel according to claim 1, wherein the organic EL panel is smaller than a limit remaining capacity. 2. The sealing substrate according to claim 1, wherein a hygroscopic agent is disposed around the filler, and a partition portion is formed so as to be positioned between the filler and the hygroscopic agent. 1. The organic EL panel according to 1. 4. The organic EL panel according to claim 3, wherein the partition portion has a convex shape and is formed to be lower than an interval between the sealing substrate and the support substrate after bonding. 5. The partition portion is formed to be lower than a maximum deflection amount of the partition portion forming portion of the sealing substrate than an interval between the sealing substrate and the support substrate after bonding. The organic EL panel as described in 2. The organic EL panel according to claim 3, wherein the sealing substrate has a surface roughness of 1 μm or more on a surface facing the organic EL element. An organic EL element having at least an organic light emitting layer sandwiched between both electrodes is formed on a support substrate, and a sealing substrate that hermetically covers the organic EL element is formed on the support substrate through an adhesive including a spacer. An organic EL panel manufacturing method comprising:
Disposing a filler containing a heat dissipating filler on the surface of the sealing substrate facing the organic EL element,
The filler is disposed such that the height when disposed is lower than the height when disposed and the diameter of the spacer is larger than the diameter of the spacer. Smaller than the diameter of
A method of manufacturing an organic EL panel, comprising: pressing and bonding the sealing substrate and the support substrate after the filler is disposed. The volume of the protruding portion disposed higher than the diameter of the spacer at the time of disposing the filler is determined based on the capacity of the designed airtight space determined based on the diameter of the spacer. It is larger than the design remaining capacity excluding the volume of the non-projecting part arranged below the diameter of the spacer, and the volume of the non-projecting part is removed from the capacity of the limit airtight space determined based on the diameter of the spacer +10 μm. The method of manufacturing an organic EL panel according to claim 7, wherein the filler is disposed so as to be smaller than a limit remaining capacity.

Images