JP4378798B2 - Flat display element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flat display element, and in particular, to a device having a feature in a sealing structure.
[0002]
[Prior art]
One type of flat display is an electroluminescent display (ELD). ELD is based on electroluminescence, which is a phenomenon that emits light when a voltage is applied to a phosphor.
[0003]
ELD is classified into inorganic EL using an inorganic compound and organic EL using an organic compound from the chemical composition of the display material (fluorescent material), and the display material is classified according to the physical shape of the display material. It is classified into a dispersion type EL in a powder form and a thin film EL in which a display material is formed into a dense thin film. In recent years, organic thin film EL among them has attracted particular attention because it can obtain high luminance at a low voltage, and since the fluorescent color of the organic compound itself is a luminescent color, it is easy to select a luminescent color.
[0004]
The organic thin film EL has a transparent anode formed on a glass substrate in a stripe shape, and an organic layer composed of an organic hole transport layer, an organic light emitting layer, and an organic electron transport layer is formed on the anode. On the top, the cathode is formed in a stripe shape perpendicular to the anode.
[0005]
As the anode, for example, an electrode made of ITO (indium-tin oxide) is used. For the cathode, for example, a metal electrode such as aluminum or an alloy of aluminum and lithium is used.
[0006]
The organic hole transport layer has a role of moving holes injected from the anode to the organic light emitting layer. The organic electron transport layer has a role of moving electrons injected from the cathode to the organic light emitting layer. A fluorescent material corresponding to the color to be displayed is used for the organic light emitting layer.
[0007]
When a voltage is applied between the anode and the cathode, holes injected from the anode move to the organic light emitting layer through the organic hole transport layer, and electrons injected from the cathode pass through the organic electron transport layer to the organic light emitting layer. Move to. These holes and electrons are recombined at the intersection of the anode and the cathode in the organic light emitting layer. The fluorescent material in the organic light emitting layer is excited with this recombination as an external stimulus. When returning from the excited state to the ground state again, fluorescence is emitted from the fluorescent material, and the light is observed through the glass substrate.
[0008]
Therefore, if a display signal and a scanning signal are supplied to the organic thin film EL by using the anode and the cathode as the signal electrode and the scanning electrode, respectively, a desired image can be displayed using each intersection of the anode and the cathode as a pixel. . (In this specification, for example, when an image is displayed in units of a plurality of pixels such as RGB pixels, the plurality of pixels are referred to as picture elements, and the image is displayed in units of a single pixel. The single picture element is also called a picture element when it is displayed.)
[0009]
By the way, an organic compound used as a fluorescent material or the like in the organic thin film EL has a property that it is very sensitive to moisture and oxygen. In addition, the characteristics of the metal constituting the anode and the cathode are rapidly deteriorated by oxidation in the air. Therefore, in the organic thin film EL flat display element, it is necessary to seal the whole of the anode, the organic layer, and the cathode.
[0010]
Conventionally, as this sealing method, there are a method of forming a polyparaxylene film as a sealing layer on the outer peripheral surface of the organic thin film EL by a gas phase polymerization method, and a method of forming a protective film of SiO2 on the outer peripheral surface. It was taken. However, since such a method does not have a high sealing effect, in recent years, a casing type sealing method and a close contact type sealing method have been developed as methods having a higher sealing effect.
[0011]
As shown in FIG. 6, the casing-type sealing method is a material with good sealing properties (for example, aluminum or iron) that covers the organic thin film EL52 (anode, organic layer, and cathode) formed on the glass substrate 51. The case 53 made of is bonded to the end portion of the substrate surface of the glass substrate 51 with an adhesive 54 in a state where a desiccant and an antioxidant (not shown) are arranged in the case 53.
[0012]
In addition, as shown in FIG. 7, the close-contact type sealing method forms a protective film (not shown) made of an inorganic compound such as GeO on the outer peripheral surface of the organic thin film EL52 formed on the glass substrate 51. Or a photocurable resin layer (not shown) is formed directly or via a SiO2 film, and a planar plate 55 made of a material having good sealing properties (for example, glass) is formed on the organic thin film EL52. The glass substrate 51 is bonded to the end portion of the substrate surface with an adhesive 56 so as to be in close contact with the substrate.
[0013]
Among these, the close contact type sealing method has the advantage that the organic thin film EL flat display element is thinned, the advantage that the display element has a simple configuration suitable for mass production, and the high sealing effect. There is an advantage that can be easily obtained.
[0014]
[Problems to be solved by the invention]
However, the casing type sealing method and the close contact type sealing method have the following inconveniences as the screen size and resolution have increased in recent years.
[0015]
That is, in recent years, the flat display tends to enlarge the screen by arranging a plurality of display units each including a flat display element as a tile. For the organic thin film EL flat display element, it is desired to realize a large screen by such unitization. In such a large screen display, it is important that the border between adjacent display units is not noticeable.
[0016]
However, in the casing type sealing method and the close contact type sealing method, as shown in FIGS. 6 and 7, the case and the glass plate are bonded to the end portion of the glass substrate surface. A column electrode, an organic layer, and a row electrode cannot be formed on the end portion of the substrate surface (that is, a pixel cannot be formed). And in order to ensure sufficient adhesive strength, the width | variety (L of FIG.6 and FIG.7) of this sticking location needs several millimeters, for example.
[0017]
Therefore, when the organic thin film EL flat display elements adopting these sealing methods are unitized to form a large screen, there is a portion where an image is not displayed with a width of about 10 mm at the boundary between adjacent display units. In the organic thin-film EL flat panel display device, as the pixel pitch becomes an order of magnitude of 0.1 mm in recent years, higher definition has progressed, whereas the width of this non-display portion is considerably large. Therefore, the boundary between the display units becomes very conspicuous due to the presence of the non-display portion.
[0018]
In the above, the organic thin film EL flat display element is taken as an example, but the same inconvenience still exists in other conventional flat display elements.
[0019]
For example, in a conventional liquid crystal flat display element, two glass substrates on which electrodes and the like are formed are bonded together with UV curable resin at the edge portions of the substrate surfaces, and after injecting liquid crystal from a liquid crystal injection port, liquid crystal injection is performed. Sealing is performed by closing the inlet with a UV curable resin.
[0020]
Also, for example, in a conventional plasma flat display element, two glass substrates on which electrodes or the like are formed are bonded with frit glass at the end portions of the substrate surfaces, and after a plasma gas is injected from a gas injection port, The inlet is sealed by welding and sealing glass with a heating wire.
[0021]
Therefore, even in these flat display elements, there is no liquid crystal or plasma gas at the edge of the glass substrate (that is, there is no picture element). The boundary of the display unit becomes conspicuous due to the presence of.
[0022]
In view of the above points, the present invention seals the display material and electrodes without arranging a non-display portion at the boundary between adjacent flat display elements when a screen is formed by arranging a plurality of flat display elements. It was made as a task to stop.
[0023]
[Means for Solving the Problems]
  In order to solve this problem, the applicant, as described in claim 1,
  First transparent substrate located on the display surface sideA plurality of anodes are formed thereon, and a plurality of organic layers including an organic hole transport layer, an organic light emitting layer, and an organic electron transport layer are formed on each of the anodes with a gap between each other. A plurality of cathodes perpendicular to the anode are formed on a layer with a gap between each other, and a black mask is formed in the gap between the organic layers and the gap between the cathodes. An organic thin film EL is formed by forming holes reaching the anode in the black mask at a position directly above the cathode and avoiding the top of the cathode,
On the organic thin film EL, a second transparent substrate located on the back surface side is superimposed so as to be in close contact with the organic thin film EL,
In the second transparent substrate, a first through hole penetrating the substrate surface is formed at a position directly above the cathode and avoiding the organic layer, and the second transparent substrate has the hole of the organic thin film EL. A second through-hole penetrating the substrate surface is formed at a position directly above,
The first through hole is sealed by gold plating or soldering through a first extraction electrode for supplying a signal to the cathode, and the second through hole supplies a signal to the anode. Sealed by gold plating or soldering through a second extraction electrode for
  The first transparent substrate and the second transparent substrate;Is made of a material with substantially the same coefficient of thermal expansion,
  The first transparent substrate and the second transparent substrateOn the side of the board,Organic thin film ELSealing thin plateButPaste with adhesiveHas beenA flat display element is proposed.
[0024]
  In this flat display element,A plurality of anodes are formed on a first transparent substrate located on the display surface side, and an organic layer composed of an organic hole transport layer, an organic light emitting layer, and an organic electron transport layer is formed on each anode with a gap between them. A plurality of cathodes formed perpendicular to the anode on the organic layer are formed with a gap between each other, and a black mask is formed in the gap between the organic layers and the gap between the cathodes. The organic thin film EL is formed by forming holes reaching the anodes in the black mask located immediately above each anode and avoiding the cathode. Then, the second transparent substrate on the back surface side is superimposed on the first transparent substrate on the display surface side where the organic thin film EL is formed in this manner so as to be in close contact with the organic thin film EL. In the transparent substrate, a first through hole penetrating the substrate surface is formed at a position directly above the cathode and avoiding the organic layer, and the substrate surface is disposed at a position directly above the hole of the organic thin film EL. A second through hole penetrating is formed, and the first through hole is sealed in a state where the first extraction electrode for supplying a signal to the cathode is passed through. The second through hole is The second extraction electrode for supplying a signal to the anode is sealed.
  Thereby, a circuit for supplying a signal to the cathode and the anode can be disposed on the back side of the second transparent substrate (that is, the back side of the flat display element).
  Also,First and secondTransparentOn the side of the board,Organic thin film ELA thin plate for sealing is attached with an adhesive.
[0025]
Thus, since sealing is performed by attaching a thin plate on the side surface side of the substrate, unlike the flat display element that performs sealing by bonding on the substrate surface as in the past, the edge of the substrate surface is Picture elements can be formed as close as possible. Further, the thickness of the thin plate can be made sufficiently smaller than the picture element pitch.
[0026]
As a result, when a plurality of flat display elements are arranged to form a screen, there is no non-display portion at the boundary between adjacent flat display elements.
[0027]
  Also, the first and secondTransparentSince the thermal expansion coefficients of the substrates are substantially equal to each other, the distances of expansion and contraction of these substrates in the substrate surface direction due to the temperature change are substantially equal to each other. Therefore, no gap is formed between the thin plate and the adhesive due to the difference in the distance between expansion and contraction, so that the sealing performance is maintained even when there is a temperature change.
[0028]
  As an example, as described in claim 2, the first transparent substrate and the second transparent substrateTransparentIt is preferable that the substrate is made of the same material. Thereby, the first and secondTransparentSince the coefficients of thermal expansion of the substrates are completely equal, the sealing performance is better maintained.
[0029]
  Also,oneAs an example, as described in claim 3,Gold bumps are formed at the tips of the first and second extraction electrodes, respectively, and the connection between the first extraction electrode and the cathode and the connection between the second extraction electrode and the anode are performed via the gold bump.Is preferred.
[0030]
  As an example, as described in claim 4, the first and secondTransparentIt is preferable that the distance from the picture element located at the extreme end of the board surface of the board to the surface of the thin plate is approximately one half of the gap between the picture elements.
[0031]
Thus, when a screen is formed by arranging a plurality of flat display elements, the picture element pitch at the boundary between adjacent flat display elements is substantially equal to the picture element pitch in each flat display element. Therefore, since the uniformity of the picture element pitch is ensured even at this boundary, this boundary becomes less noticeable.
[0032]
As an example, as described in claim 5, it is preferable that the thin plate and the adhesive are made of a material that is transparent and has a refractive index substantially equal to that of the first transparent substrate.
[0033]
As a result, the thin plate or the adhesive itself is not seen as a joint, and light reflection at the boundary between the first transparent substrate and the thin plate or the adhesive is prevented. Less noticeable.
[0034]
Further, as an example, the adhesive is made of a material that is transparent and has a refractive index substantially equal to that of the first transparent substrate, and the thin plate is made of the same material as that of the first transparent substrate. It is preferable to comprise. Thereby, since the refractive indexes of the thin plate and the first transparent substrate are completely equal, reflection of light at the boundary between the first transparent substrate and the thin plate is further prevented.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example in which the present invention is applied to an organic thin film EL flat display device will be described.
[0036]
FIG. 1 is a side sectional view showing an example of the configuration of an organic thin film EL flat display element (hereinafter simply referred to as a display element) to which the present invention is applied. In this display element 1, an organic thin film EL3 is formed on a glass substrate (substrate on the display surface side) 2 having a thickness of about 1 mm to the immediate vicinity of the end of the substrate surface. Here, the term “organic thin film EL” is used to indicate an anode, an organic layer, and a cathode formed on a substrate.
[0037]
FIG. 2 shows an example of the structure of the organic thin film EL3. In this organic thin film EL3, a plurality of ITO electrodes (anodes) on the glass substrate 2 are grouped into three ITO electrodes (anodes) 11a, 11b and 11c each having a narrow gap therebetween. It is formed in stripes with the gap between them widened.
[0038]
On the ITO electrode 11a, an organic layer (an organic hole transport layer, an organic light emitting layer, and an organic electron transport layer) 12a having a length substantially equal to the width w of each group of ITO electrodes is formed. A plurality of the gaps are formed so as to be substantially equal to the gap g between the groups. Organic layers 12b and 12c are formed on the ITO electrodes 11b and 11c in exactly the same manner. In each of the organic layers 12a, 12b, and 12c, a red fluorescent material, a green fluorescent material, and a blue fluorescent material are used for the organic light emitting layer, respectively.
[0039]
On each of the organic layers 12a, 12b, and 12c, a plurality of aluminum electrodes (cathodes) 13 having a width substantially equal to the width w of each group of ITO electrodes is formed, and a gap g between each group of ITO electrodes is formed. Are formed in stripes perpendicular to the ITO electrodes.
[0040]
Black masks (not shown) are formed in the gaps between the ITO electrodes 11a, 11b, and 11c, the gaps between the organic layers 12a, 12b, and 12c, and the gaps between the aluminum electrodes 13.
[0041]
Thereby, in this display element 1, as shown in FIG. 1, it consists of each organic layer 12a, 12b, 12c to the immediate vicinity of the edge of the substrate surface of the glass substrates 2 and 4 (that is, it consists of each pixel of RGB). ) A picture element PX is formed. The pitch p of this picture element PX (the sum of the gap g and the width w in FIG. 2) is, for example, about 0.5 mm.
[0042]
Note that holes m reaching the ITO electrodes 11a, 11b, and 11c are formed in the black mask that is located immediately above the respective ITO electrodes 11a, 11b, and 11c and that is away from the top of the aluminum electrode 13. (In the figure, the portions where the holes reach the ITO electrodes 11a, 11b, and 11c are shown as m). As a method of forming the hole m, there is a method of forming a black mask by providing a mask pattern at the position of the hole m in advance, or a method of forming a hole in the black mask by irradiating an excimer laser after forming the black mask. It is taken.
[0043]
As shown in FIG. 1, a glass substrate 4 is superimposed on the organic thin film EL3 so as to be in close contact with the organic thin film EL3. As the glass substrate 4, the same glass substrate as that used as the glass substrate 2 is used, and therefore the size and material thereof are exactly the same as those of the glass substrate 2.
[0044]
Although not shown in FIG. 1, the glass substrate 4 has a position directly above each aluminum electrode 13 and avoiding the top of the organic layers 12a, 12b, and 12c (that is, a position avoiding the top of the picture element). In addition, a hole penetrating the substrate surface is formed, and a hole penetrating the substrate surface is also formed at a position directly above each hole m (FIG. 2) of the organic thin film EL3.
[0045]
3A and 3B are views showing the holes of the glass substrate 4 from a direction parallel to the ITO electrode and a direction parallel to the aluminum electrode, respectively. A hole n1 is formed at a position directly above each aluminum electrode 13 and avoiding the top of the organic layers 12a, 12b, 12c, and a hole n2 is formed at a position directly above the hole m in the organic thin film EL3. Has been.
[0046]
As a method for forming the holes n1 and n2, a method of drilling holes or a sand blasting (grid blasting) method in which sand or an abrasive is sprayed onto an object at high speed is employed.
[0047]
Each hole n1 is sealed by gold plating or soldering in a state where the extraction electrode 5 for supplying a scanning signal to the aluminum electrode 13 is passed. Each hole n2 is sealed by gold plating or soldering with a takeout electrode 6 for supplying a display signal to the ITO electrodes 11a, 11b, and 11c.
[0048]
Gold bumps 21 are respectively formed at the tips of the extraction electrodes 5 and 6. As a method of forming the gold bump 21, for example, a method is adopted in which a ball-like lump formed at the tip of the gold wire is taken out by ball bonding, and the gold wire is cut after being joined to the tips of the electrodes 5 and 6. .
[0049]
An adhesive layer 22 made of a thermoplastic resin is formed between the organic thin film EL3 and the glass substrate 4. As a method for forming the adhesive layer 22, for example, a polyester, vinyl chloride, vinyl acetate, polyamide or polyurethane-based thermoplastic resin is heated and softened, and then the organic thin film EL3 and glass are printed by a printing method or a film laminating method. A method of applying to any of the substrates 4 is employed.
[0050]
The glass substrate 2 and the glass substrate 4 are cooled to a temperature at which the adhesive layer 22 is cured after being pressed to each other in a state where the adhesive layer 22 is heated to a temperature at which the adhesive layer 22 is softened. Thus, the connection between the extraction electrode 5 and the aluminum electrode 13 and the connection between the extraction electrode 6 and the ITO electrodes 11a, 11b, and 11c are made through the gold bumps 21.
[0051]
Further, the hole n1 through which the extraction electrode 5 passes is formed at a position avoiding the top of the picture element, and the hole n2 through which the extraction electrode 6 passes is also formed at a position avoiding the top of the aluminum electrode 13, so that the glass substrate It is prevented that the organic thin film EL3 is damaged when 2 and the glass substrate 4 are pressed against each other.
[0052]
As shown in FIG. 1, a thin glass plate 8 is attached to the side surfaces of the glass substrates 2 and 4 with an adhesive 7 over the entire surface. Although only one sheet glass 8 is shown in FIG. 1, as shown in FIG. 4, one sheet glass 8 is affixed to each of the four sides of the side surface.
[0053]
The adhesive 7 is an epoxy UV curable adhesive with low moisture permeability, and is transparent and has a refractive index of about 1.4 to 1.7 (that is, the refractive index is substantially equal to that of the glass substrate 2). Things are used.
[0054]
The thin glass 8 is a transparent glass having a thickness of about 50 μm. The distance x from the picture element PX located at the end of the substrate surface of the glass substrates 2 and 4 to the surface of the thin glass plate 8 is determined to be approximately one half of the gap g between the picture elements PX. .
[0055]
All the operations up to the attachment of the thin glass 8 are performed in an oxygen-free dry atmosphere such as a dry nitrogen atmosphere in order to prevent deterioration of the organic thin film EL3 due to moisture and oxygen.
[0056]
In this manner, in the display element 1, the organic thin film EL 3 (ITO electrode, organic layer, and aluminum electrode) is sealed by attaching the thin glass 8 on the side surfaces of the glass substrates 2 and 4. A picture element PX is formed as close as possible to the edges of the substrate surfaces of the glass substrates 2 and 4, and the distance x from the picture element PX located at the end of the substrate surface to the surface of the thin glass 8 is a picture. It is about half of the gap g between the elements PX.
[0057]
Next, how the plurality of display elements 1 are arranged will be described. FIG. 5 is a side sectional view showing the boundary between adjacent display elements 1 when a plurality of display elements 1 are arranged.
[0058]
Since the picture element PX is formed close to the edge of the substrate surface of each display element 1, there is no non-display portion at the boundary between the adjacent display elements 1. Further, since the distance x is approximately one half of the gap g, the gap g ′ between the picture elements PX at this boundary is substantially equal to the gap g. Therefore, the pixel pitch p at this boundary is 'Is substantially equal to the pixel pitch p in each display unit.
[0059]
In this way, since the uniformity of the picture element pitch is ensured even at the boundary between adjacent display elements 1, when the display element 1 is unitized to form a large screen, the boundary between adjacent display units becomes inconspicuous. .
[0060]
Further, as the material of the adhesive 7, a transparent material having a refractive index substantially equal to that of the glass substrate 2 is used, and a transparent thin glass 8 is attached to the side surfaces of the glass substrates 2 and 4. Therefore, the thin plate or the adhesive itself is not seen as a joint, and light reflection at the boundary between the first transparent substrate and the thin plate or the adhesive is prevented. This makes the boundary between adjacent display units less noticeable.
[0061]
As described above, in this display element 1, the organic thin film EL 3 is sealed so that the boundary between adjacent display elements 1 does not stand out when a plurality of display elements are arranged.
[0062]
Moreover, since the same thing as what is used as the glass substrate 2 is used for the glass substrate 4, since the glass substrates 2 and 4 have the same thermal expansion coefficient, these board | substrate directions by the temperature change of these board | substrates are used. The stretch distances are equal to each other. Therefore, there is no gap between the thin glass plate 8 and the adhesive 7 due to the difference in the distance between expansion and contraction, so that the sealing performance is maintained even when there is a temperature change.
[0063]
The glass substrate 4 on the back side is provided with holes n1 and n2 through extraction electrodes 5 and 6 for supplying scanning signals and display signals to the aluminum electrode and the ITO electrode. A drive circuit for supplying a display signal can be arranged on the back side of the glass substrate 4 (that is, the back side of the flat display element 1).
[0064]
In the above example, the same substrate used as the glass substrate 2 is used as the substrate on the back side. However, as another example, a glass substrate different from that used as the glass substrate 2 or a transparent resin substrate having a thermal expansion coefficient substantially equal to that of the glass substrate 2, at least the dimension of the substrate surface is the glass substrate 2. May be used as the substrate on the back side.
[0065]
In the above example, the thin glass 8 is attached to the side surfaces of the glass substrates 2 and 4. However, as another example, a transparent resin thin plate having a refractive index substantially equal to that of the glass substrate 2 may be attached to the side surfaces of the glass substrates 2 and 4.
[0066]
In the above example, the present invention is applied to the organic thin film EL flat panel display element. However, the present invention is not limited to this. For example, display materials and electrodes such as a liquid crystal flat panel display element and a plasma flat panel display element are sealed. The present invention may be applied to an appropriate flat display element that is necessary.
[0067]
When the present invention is applied to a liquid crystal flat display element or a plasma flat display element, the thin glass is pasted on the side surfaces of the two glass substrates originally present on the display surface side and the back surface side of these flat display elements. The electrode and the drive circuit may be connected by a method usually used for these flat display element electrodes without making a hole in the glass substrate on the back side.
[0068]
Further, the present invention is not limited to the above example, and it is needless to say that various other configurations can be taken without departing from the gist of the present invention.
[0069]
【The invention's effect】
  As described above, according to the flat display element according to claim 1 of the present invention,A plurality of anodes are formed on a first transparent substrate located on the display surface side, and an organic layer composed of an organic hole transport layer, an organic light emitting layer, and an organic electron transport layer is formed on each anode with a gap between them. A plurality of cathodes formed perpendicular to the anode on the organic layer are formed with a gap between each other, and a black mask is formed in the gap between the organic layers and the gap between the cathodes. The organic thin film EL is formed by forming holes reaching the anodes in the black mask located immediately above each anode and avoiding the cathode. Then, the second transparent substrate on the back surface side is superimposed on the first transparent substrate on the display surface side where the organic thin film EL is formed in this manner so as to be in close contact with the organic thin film EL. In the transparent substrate, a first through hole penetrating the substrate surface is formed at a position directly above the cathode and avoiding the organic layer, and the substrate surface is disposed at a position directly above the hole of the organic thin film EL. A second through hole penetrating is formed, and the first through hole is sealed in a state where the first extraction electrode for supplying a signal to the cathode is passed through. The second through hole is Since the second extraction electrode for supplying a signal to the anode is sealed, the circuit for supplying the signal to the cathode and the anode can be arranged on the back surface side of the flat display element. An effect is obtained.
  A first transparent substrate and a second transparent substrate;Since the sealing is performed by attaching a thin plate on the side surface of the display, when a screen is formed by arranging a plurality of flat display elements, there is no non-display portion at the boundary between adjacent flat display elements. The effect that it can be made is acquired.
[0070]
  Also, the first and secondTransparentSince the thermal expansion coefficients of the substrates are substantially equal to each other, the effect that the sealing performance is maintained even when there is a temperature change can be obtained.
[0071]
  Moreover, according to the flat display element of Claim 2, 1st and 2ndTransparentSince the coefficients of thermal expansion of the substrates are completely equal, the effect of better maintaining the sealing performance can be obtained.
[0073]
According to the flat display element of claim 4, when a plurality of flat display elements are arranged to form a screen, uniformity of the pixel pitch is ensured even at the boundary between adjacent flat display elements. Therefore, the effect of making this boundary more inconspicuous is obtained.
[0074]
According to the flat display element of claim 5, the thin plate or the adhesive itself is not seen as a joint, and the reflection of light at the boundary between the first transparent substrate and the thin plate or the adhesive is prevented. Therefore, the effect of making the boundary between adjacent flat display elements less noticeable can be obtained.
[0075]
According to the flat display element of the sixth aspect, since the refractive indexes of the thin plate and the first transparent substrate are completely equal, the reflection of light at the boundary between the first transparent substrate and the thin plate is further reduced. The effect that it can prevent well is acquired.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing an example of the configuration of an organic thin film EL flat display element to which the present invention is applied.
2 is a perspective view showing an example of the structure of the organic thin film EL in FIG. 1. FIG.
3 is a side cross-sectional view showing an example of a state of connection between the take-out electrode, the aluminum electrode, and the ITO electrode of FIG. 1;
4 is a perspective view showing an example of an external shape of the organic thin film EL flat display element of FIG. 1. FIG.
5 is a side cross-sectional view showing a boundary between display elements when a plurality of the display elements in FIG. 1 are arranged. FIG.
FIG. 6 is a side sectional view showing an example of a sealing structure of a conventional organic thin film EL flat display element.
FIG. 7 is a side sectional view showing an example of a sealing structure of a conventional organic thin film EL flat display element.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Organic thin film EL plane display element, 2,4 Glass substrate, 3 Organic thin film EL, 5,6 Extraction electrode, 7 Adhesive, 8 Thin glass, 11a, 11b, 11c ITO electrode, 12a, 12b, 12c Organic layer, 13 Aluminum electrode, 14 Black mask, 21 Gold bump, 22 Adhesive layer, m Hole in organic thin film EL, n1, n2 hole in glass substrate, PX picture element

Claims (6)

A plurality of anodes are formed on a first transparent substrate located on the display surface side, and an organic layer composed of an organic hole transport layer, an organic light emitting layer, and an organic electron transport layer is disposed between each of the anodes. And a plurality of cathodes orthogonal to the anode are formed on the organic layer with a gap between each other, and a gap between the organic layers and a gap between the cathodes are formed. A black mask is formed on the black mask, and an organic thin film EL is formed by forming a hole reaching the anode in the black mask at a position directly above each anode and avoiding the top of the cathode. And
On the organic thin film EL, a second transparent substrate located on the back surface side is superimposed so as to be in close contact with the organic thin film EL,
In the second transparent substrate, a first through hole penetrating the substrate surface is formed at a position directly above the cathode and avoiding the organic layer, and the second transparent substrate has the hole of the organic thin film EL. A second through-hole penetrating the substrate surface is formed at a position directly above,
The first through hole is sealed by gold plating or soldering through a first extraction electrode for supplying a signal to the cathode, and the second through hole supplies a signal to the anode. Sealed by gold plating or soldering through a second extraction electrode for
The first transparent substrate and the second transparent substrate are made of materials having substantially the same coefficient of thermal expansion,
Wherein the first transparent substrate and the side surface of the second transparent substrate, the organic thin film EL flat panel display devices thin plate sealing that are affixed by adhesive. The flat display element according to claim 1,
Flat display element and the first transparent substrate and said second transparent substrate that consist of the same material. The flat display element according to claim 1 or 2,
Gold bumps are respectively formed at the tips of the first and second extraction electrodes, and the connection between the first extraction electrode and the cathode and the connection between the second extraction electrode and the anode are the gold bumps. A flat display element performed via The flat display element according to any one of claims 1 to 3,
The distance from the picture element located at the extreme end of the substrate surface of the first transparent substrate and the second transparent substrate to the surface of the thin plate is approximately one half of the gap between the picture elements. flat panel display devices that. The flat display element according to any one of claims 1 to 4,
It said sheet and said adhesive is a transparent and refractive index of the first transparent substrate and flat panel display devices that consist substantially equal material. The flat display element according to claim 5,
The thin plate, flat panel display devices that consist of the same material as the first transparent substrate.

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