JPH07295484A - Thin film el display - Google Patents

Abstract

PURPOSE:To facilitate the connection between the electrodes of adjacent panels by shortening the intervals between the electrodes of adjacent thin film EL panels, and making the interval between the display picture elements at the joint small, and equalizing the interval between the display picture elements at the joint and the interval between the adjacent display picture elements within the same panel. CONSTITUTION:Thin film EL panels 201 and 202 of a thin film emission structure are provided in succession by arranging a plurality of transparent electrodes 22 and a plurality of upper electrodes 26, with EL element layers 24 inbetween, in a matrix shape on a glass board 21, and also each band-shaped conductor connects the upper electrodes that each thin film El panel corresponds to by covering each thin film EL panel with a cover glass board 27 in which a plurality of band shaped conductors 27 for connecting the upper electrodes which each thin film EL panel corresponds to are made on one side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an EL device by applying an electric field.
The present invention relates to a thin film EL display in which a plurality of thin film EL panels having a thin film light emitting structure for emitting light are arranged in series.

[0002]

2. Description of the Related Art A thin film EL (Elec
tro Luminescent) panel is a translucent insulating substrate with a lower electrode layer, a lower dielectric layer, a thin film active layer made of zinc sulfide containing an active element such as manganese, an upper dielectric layer, and an upper electrode. It has a structure in which layers are sequentially laminated. By connecting the lower electrode and the upper electrode to an AC power source, the thin film EL element is emitting light.

In order to prevent electric field corrosion and deterioration with time due to atmosphere, such a thin film EL panel is sealed using oil or solid resin so that the inside of the element has a hermetically sealed structure in a case made of glass. It has stopped.

The thin film EL panel is a surface emitting light source whose light emitting area can be arbitrarily selected. Recently, a thin film EL panel is required to have a wide light emitting area because it is used for illumination, an indication display panel and the like.

However, in a thin film EL panel, it is difficult to form an active layer or a dielectric layer with a uniform film thickness over the entire area when the area of the light emitting area is increased, so that uneven brightness occurs in the light emitting area. There is a problem of doing.

For this reason, it is known that a plurality of thin film EL panels each having a light emitting region having a relatively small area are connected in series to form a display having a wide light emitting region as a whole.

[0007] For example, Japanese Utility Model Laid-Open No. 105496/1992 discloses a technique for continuously arranging an organic thick film dispersion type EL.

As shown in FIG. 15, this is a transparent substrate 1
A transparent electrode 2, a phosphor layer 3, a dielectric layer 4, and a counter electrode 5 are sequentially formed on the surface of, and an auxiliary electrode 6 is attached on the transparent electrode 2, and a portion indicated by a chain line in the figure is cut by an outer shape cutting process. By removing it, the light emitting layer composed of the transparent electrode 2, the phosphor layer 3 and the dielectric layer 4 is exposed on the side end face to form one EL panel 7.
To form.

This EL panel 7 is shown in FIG.
The opposite electrodes 5 of the adjacent EL panels 7 and the adjacent electrodes 5 are arranged by using the strip-shaped conductor 8 which is formed by applying the conductive adhesive or the conductive adhesive on one surface of the insulating film or the metal foil by arranging the side end surfaces to face each other. The auxiliary electrodes 6 are connected to each other.
The counter electrode 5 and the strip-shaped conductor 8 of each EL panel 7 are covered with the hygroscopic agent 9 and the sealing film 10, and the translucent substrate 1 of each EL panel 7 is covered with the translucent sealing film 11 to be hermetically sealed. To do.

As described above, an EL display having a wide light emitting region is constructed by using a plurality of EL panels 7.

However, if this organic thick film dispersion type EL connection technique is applied to the connection of thin film EL as it is, the sealing becomes insufficient and the life is shortened.

Therefore, when the thin film ELs are connected in series, the thin film EL panel is sealed with a casing made of glass or the like using oil or solid resin so that the inside of the thin film EL panel has a closed structure.

As shown in FIG. 16, the thin film EL panel has a transparent electrode 13, a lower insulating layer, and an EL on the surface of a glass substrate 12.
A light emitting layer, a layer 14 of an upper insulating layer, and an upper electrode 15 are sequentially formed into a thin film, and a cover glass 16 is formed on the thin film.

[0014]

When a plurality of thin-film EL panels having such a structure are arranged in series, the transparent electrode 13 and the upper electrode 15 are widened because the distance between the transparent electrodes 13 in the continuous section of the panel becomes wide. The distance between the display pixels, which is the crossing point between and, becomes wider between the display pixels of the adjacent panels. For example, when characters are scroll-displayed on a display in which a plurality of thin film EL panels are arranged in series, the characters are traced in the connection section. There is a problem that the display quality is degraded due to the break.

Therefore, if the distance from the transparent electrode 13 of the thin film EL panel to the panel end is shortened and the interval between the display pixels in the continuous portion is made equal to the interval between the adjacent display pixels in the same panel, the adjacent thin film EL is adjacent. Panel transparent electrode 1
The distance from 3 to the end of the panel becomes too short, and there is a problem that connection is difficult with a strip-shaped conductor formed by applying a conductive adhesive or a conductive adhesive on one surface of a conventional insulating film or metal foil. It was

Therefore, according to the present invention, the distance between the electrodes of adjacent thin film EL panels can be shortened, and therefore the interval between the display pixels in the continuous portion of the thin film EL panel can be made sufficiently small, and the display pixel in the continuous portion can be reduced. (EN) Provided is a thin film EL display in which the distance and the distance between adjacent display pixels in the same panel can be made equal and the electrodes of adjacent thin film EL panels can be easily connected.

The present invention also provides a thin film EL display capable of reliably sealing each thin film EL panel.

[0018]

The invention according to claim 1 is
A plurality of lower electrodes are arranged on a transparent first insulating substrate, and a plurality of upper electrodes are arranged in a matrix on each lower electrode via an EL light emitting layer to form a thin film light emitting structure. A plurality of thin film EL panels are arranged in a row, and a second insulating substrate having a plurality of strip-shaped conductors for connecting between the corresponding upper electrodes of each thin film EL panel is prepared on one surface side. By covering each thin film EL panel with an insulating substrate, each strip-shaped conductor connects the corresponding electrodes of each thin film EL panel.

According to a second aspect of the present invention, in the first aspect of the invention, the second insulating substrate is composed of one substrate,
The thin film EL panel is covered and integrated with the substrate.

According to a third aspect of the present invention, a plurality of lower electrodes are arranged on a light-transmitting first insulating substrate, and a plurality of upper electrodes are arranged on each of the lower electrodes via an EL light emitting layer. A plurality of thin-film EL panels, which are arranged in a rectangular pattern to form a thin-film light-emitting structure, are connected in series, and a plurality of strip-shaped conductors for connecting the corresponding upper electrodes of the thin-film EL panels are formed on one surface side. An insulative substrate is prepared, and each thin film EL panel is covered with the second insulative substrate so that each strip-shaped conductor connects between the corresponding electrodes of each thin film EL panel,
An insulating resin is filled between the insulating substrates and cured.

[0021]

In the invention having such a structure, each strip-shaped conductor corresponds to each thin-film EL panel by covering each thin-film EL panel with the second insulating substrate having a plurality of strip-shaped conductors formed thereon. The electrodes will be connected.

The insulating substrates of each thin film EL panel are sealed with an insulating resin.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows two thin film EL panels 201 and 20.
2 is a perspective view of an EL thin film display in which two are arranged in series, FIG.
FIG. 4 is a partial cross-sectional view of a continuous portion of the EL thin film display.

The thin film EL panels 201 and 202 are formed by the process shown in FIG. First, as shown in FIG. 3A, a glass substrate 21 which is a translucent first insulating substrate.
After thoroughly cleaning, the ITO (indium tin
A transparent conductive film made of oxide) is formed to a thickness of 1000 angstrom, and the transparent conductive film 22 is formed as a lower electrode by performing etching or the like so as to form a stripe parallel arrangement as shown in FIG.

Subsequently, as shown in FIG. 3B, a lower insulating film is formed by rf sputtering to form a lower insulating layer 23.
To form. The lower insulating layer 23 is made of, for example, Si--N.
A film is formed to a thickness of 500 angstroms, and SiO ₂ is further formed thereon to a film thickness of 500 angstroms.

Other insulating films include Y ₂ O ₃ and A
There are l ₂ O ₃ , Si ₃ N ₄ , and composite films of these insulating materials, etc., which are selected depending on the processing process and the required dielectric constant. Further, as a film forming method, there are CVD and EB vapor deposition.

Then, as shown in FIG. 3 (c), ZnS:
About 50 Mn (Mn concentration 0.4 wt%) with EB evaporation system
E to form a film with a thickness of 00 to 10000 angstroms
The L light emitting layer 24 is formed.

As the film forming method, in addition to EB vapor deposition, there are methods such as sputtering method, CVD, hot wall epitaxy and molecular beam epitaxy.

Further, as the EL light emitting layer 24, ZnS:
In addition to Mn, ZnSe, SrS, TbF ₃ , ErF ₃ , TmF ₃ , DyF ₃ , which serve as an emission center in a material having an energy gap larger than the energy of emitted light,
Any combination is possible as long as it exhibits HoF ₃ and SmF ₃ characteristics.

Subsequently, as shown in FIG. 3D, an upper insulating film is formed by rf sputtering to form an upper insulating layer 25.
To form. Similar to the lower insulating layer 23, the upper insulating layer 25 is formed by depositing Si-N to a thickness of 2500 Å and further depositing SiO ₂ to a thickness of 500 Å thereon.

Finally, as shown in FIG. 3 (e), A
l is formed into a film and is patterned so as to be orthogonal to the transparent electrode 22 in a stripe shape to form an upper electrode 26. That is, the upper electrode 26 and the transparent electrode 22 are arranged in a matrix with the lower insulating layer 23, the EL emission layer 24, and the upper insulating layer 25 interposed therebetween.

Thus, the thin film EL panel 20 having the thin film light emitting structure as shown in FIG. 5 is constructed. That is,
The transparent electrode 22 formed on the glass substrate 21 is formed at a position slightly away from the tip of the substrate 21 on one end side, but is formed at a position near the tip of the substrate 21 on the other end side.

Then, as shown in FIG. 7, two thin film EL panels 201 and 202 are prepared, and the transparent electrode 22 or the upper electrode 26, for example, the upper electrodes 26 are aligned and abutted by a jig. At this time, each thin film EL panel 20
Reference numerals 1 and 202 respectively abut the transparent electrode 22 on the side close to the tip of the substrate 21. As a result, the transparent electrodes 2 adjacent to each other in the continuous portion of the thin film EL panels 201 and 202 are connected.
The interval of 2 corresponds to the interval of the other transparent electrodes 22.

Then, as shown in FIG.
One cover glass substrate 27, which is a second insulating substrate that collectively covers the panels 201 and 202, is attached to the thin film EL panel 2.
Place it on 01, 202. The thin film EL panel 20
A spacer 28 is inserted at the end portion on the outer side of 2. or,
Although not shown, a spacer 28 is provided at a predetermined position depending on the panel area.
Is further inserted. Polyimide is used as the spacer 28.

The cover glass substrate 27 has a plurality of belt-shaped conductors 29 formed on one surface thereof, that is, on the side in contact with the thin film EL panels 201 and 202. The strip-shaped conductors 29 cover the cover glass substrate 27 and the thin-film EL panel 2.
Thin film EL panel 2 when placed at a predetermined position 01, 202
01 and the upper electrode 26 of the thin film EL panel 202.

The band-shaped conductor 29 is made of a conductive adhesive or a conductive adhesive, and is formed by patterning by screen printing as shown in FIG. In addition, 3 in the figure
1 is a squeegee, 32 is a screen, 33 is a strip conductor 2
It is a material that becomes 9.

The cover glass substrate 27 is of the same type and has the same thickness as the glass substrate 21 in consideration of the stress generated in the EL such as the expansion coefficient and the wavelength region of light. For example, 1.1 mm thick Corning 7059 is used.

The cover glass substrate 27 is aligned with a jig and placed on the thin film EL panels 201 and 202 at predetermined positions. At that time, an adhesive having a higher viscosity than the encapsulating resin such as epoxy resin, easy to apply, and highly moisture-proof is applied around the cover glass substrate 27 by using a supply device and fixed under pressure. .

Then, the photocurable adhesive is permeated through the gap between the two glass substrates 21 and 27 with a dropper or the like. As the light curable adhesive, for example, an acrylic visible light curable adhesive having a low viscosity is used.

In addition to the visible light curable adhesive, an ultraviolet curable adhesive or a highly viscous photocurable adhesive such as olefin may be used.

After permeating the visible light curable adhesive, defoaming in the adhesive layer and the cover glass substrate 27 and E
Around the L panels 201, 202 and the EL panels 201,
The adhesive is sufficiently penetrated into the space between 202 and then cured.

Thus, the two thin film EL panels 201,
When the 202 are connected in series, each thin film EL panel 201,
Since the transparent electrodes 22 of No. 02 are arranged so that the sides close to the tip of the substrate 21 are butted against each other, each thin film EL panel 2
The distance between the transparent electrodes 22 adjacent to each other in the continuous portion of 01 and 202 coincides with the distance between the other transparent electrodes 22.
Therefore, when two thin film EL panels 201 and 202 are arranged in series to form one EL display,
The interval between the display pixels in the continuous portion of the panels 201 and 202 does not become wider than the interval between the other display pixels.

Therefore, even when the characters are scroll-displayed, the characters are not cut off in the continuous portion, and the display quality can be secured.

Two thin film EL panels 201, 20
After the two strips are connected in series, a cover glass substrate 27 having a plurality of strip-shaped conductors 29 formed on one surface thereof is placed thereon and fixed under pressure. Since the upper electrodes 26 are connected to each other, the upper electrodes 26 can be easily and surely connected to each other even if the distance between the adjacent upper electrodes 26 of the continuous portion is short.

Two thin film EL panels 201 and 20 are also provided.
2 is covered and sealed with one cover glass substrate 27, so that the airtightness is good, and moreover, the resin is filled inside and the viscosity around the cover glass substrate 27 is higher than that of the filled resin.
Since an adhesive that is easy to apply and has high moisture resistance is applied and fixed under pressure, intrusion of moisture and the like can be reliably prevented, and a long life can be achieved.

Next, another embodiment of the present invention will be described with reference to the drawings. The same parts as those in the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 9A, a belt-shaped conductor 39 mixed with spherical glass bead powder 38 is formed on one surface of the cover glass substrate 27 by using the screen printing method shown in FIG. As the belt-shaped conductor 39, for example, nickel, silver, or highly conductive metal fine particles in which a spherical glass bead powder 38 having a spherical diameter of 3 to 100 μm is dispersed and mixed in a resin or an adhesive having a solvent or an adhesive component. Are using.

Before the band-shaped conductor 39 is cured, the two thin film EL panels 201 and 202 are butted, and one surface side of the cover glass substrate 27 is placed on the thin film EL panels 201 and 202 as shown in FIG. 9B. Place it toward.

Then, the belt-shaped conductor 39 is cured while the cover glass substrate 27 is pressed by the pressing jig. As a result, the belt-shaped conductor 39 is crushed as shown in FIG. 9 (c), but the spherical glass bead powder 38 is mixed therein, so that the cover glass substrate 27 and the thin-film EL panels 201 and 201.
The distance between the upper electrode 26 and the upper electrode 26 is regulated by the diameter of the spherical glass bead powder 38. Further, the conductive fine particles of the strip-shaped conductor 39 are brought into contact with or pushed into the upper electrode 26, and the upper electrode 26 between the thin film EL panels 201 and 202 is electrically connected.

After that, each thin film EL panel 201, 202
The encapsulating resin is permeated into the gap between the glass substrate 21 and the cover glass substrate 27. As a result, the encapsulating resin also enters the upper portion of the EL light emitting layer 24, and the belt-shaped conductor 39 is hardened by the resin while maintaining the connection state with the upper electrode 26.

Further, since the resin cannot be sufficiently filled in the continuous portion of the thin film EL panels 201 and 202 by only permeating the resin, the gap is filled with the resin separately by using, for example, a syringe.

By mixing the spherical glass bead powder 38 into the strip conductor 39 in this manner, the cover glass substrate 27 and the upper electrode 26 on the thin film EL panels 201 and 202 are mixed.
Since the distance between and is regulated by the diameter of the spherical glass bead powder 38, the distance can be made uniform with high accuracy.

In other respects, this embodiment can obtain the same effects as those of the above embodiment.

As a method for forming the strip-shaped conductor 39 on the one surface side of the cover glass substrate 27, a resin dispenser as shown in FIG. 10 may be used in addition to the screen printing method described above.

That is, as shown in FIG. 10 (a), the conductive adhesive that becomes the belt-shaped conductor 39 is applied to the resin dispenser 40.
10 and then set on the support member 41, and while moving the support member 41 at a constant speed, the resin dispenser 4 is attached to one surface of the cover glass substrate 27 as shown in FIG. 10 (b).
A certain amount of conductive adhesive is injected from 0 to form a strip-shaped conductor 39.
To form.

In each of the above embodiments, two thin film EL panels 2 are used.
The case where the EL display is configured by connecting 01 and 202 in series has been described, but the present invention is not necessarily limited to this.

For example, FIG. 11 shows ten thin film EL panels 3
It shows a case where the EL display is configured by connecting the columns 01 to 310 in two columns vertically and five columns horizontally. Then, one cover glass substrate 271 is placed on each of the thin film EL panels 301 to 310 arranged in series.

The cover glass substrate 271 is formed with strip-shaped conductors 291 for connecting the upper electrodes 26 arranged in five rows. Since the transparent electrode 22 is connected to the drive system, lead-out portions of the electrode are provided on the upper and lower sides, respectively, and the upper electrode 26 is a common electrode, so the lead-out portion is provided on only one side.

The EL display constructed in this way has a relatively large display screen, and for example, not only 16 × 16 dot Chinese character display but also 32 × 32 dot large Chinese character display is possible.

FIG. 12 shows 20 thin film EL panels 4
The case where the EL display is configured by connecting 01 to 420 in four columns vertically and five columns horizontally is shown. Then, one cover glass substrate 272 is placed on each of the thin film EL panels 401 to 420 arranged in series.

As shown in FIG. 13, in each of the thin film EL panels 401 to 420, after the upper electrode 26 is formed in the manufacturing process of the thin film EL panels 401 to 420, the passivation film 51 is further formed thereon. .

A plurality of strip-shaped conductors 291 for connecting the upper electrodes 26 of the respective thin film EL panels arranged laterally thereon are connected.
And a cover glass substrate 272 formed with a plurality of relatively thick strip-shaped conductors 292 for connecting the transparent electrodes 22 of the thin film EL panels arranged vertically is fixed under pressure.

The strip-shaped conductor 291 is pressure-bonded between the upper electrodes 26 of the respective thin-film EL panels to connect both electrodes, as in the above-mentioned embodiment. Further, the tip end of the strip-shaped conductor 292 is crimped between the transparent electrodes 22 of each thin film EL panel to connect both electrodes.

The strip-shaped conductor 292 can be formed on the cover glass substrate 272 by a screen printing method or a method using a resin dispenser like the strip-shaped conductor 291.

By doing so, an EL display having a larger screen can be constructed.

[0067]

As described above, according to the present invention, the adjacent thin film E
The distance between the electrodes of the L panel can be shortened, so that the distance between the display pixels in the continuous portion of the thin film EL panel can be made sufficiently small.
Further, the interval between the display pixels in the continuous portion and the interval between the adjacent display pixels in the same panel can be made equal. As a result, when the characters are scroll-displayed, the display quality can be ensured without the characters being cut off in the continuous portion.

Further, a strip-shaped conductor is formed in advance on a second insulating substrate which covers each thin-film EL panel, and when the thin-film EL panel is covered with the second insulating substrate, the strip-shaped conductor has each thin film. Since the electrodes of the EL panel are pressure-bonded to each other to connect the electrodes, the electrodes of the thin film EL panels adjacent to each other can be easily connected.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing the configuration of a continuous portion of the thin film EL panel of the same example.

FIG. 3 is a view for explaining the manufacturing process of the thin film EL panel of the same example.

FIG. 4 is a view showing an example of a pattern of transparent electrodes of the thin film EL panel of the same example.

FIG. 5 is a plan view showing the configuration of the thin film EL panel of the same example.

FIG. 6 is a diagram showing a screen printing method used for forming a belt-shaped conductor on the cover glass substrate of the same example.

FIG. 7 is a perspective view of two thin film EL panels connected in series according to the embodiment.

FIG. 8 is a perspective view showing a thin film EL panel of the same embodiment and a cover glass substrate mounted on this panel.

FIG. 9 is a partial cross-sectional view for explaining a step of placing a cover glass substrate on and adhering the cover glass substrate to the thin film EL panel in another embodiment of the present invention.

FIG. 10 is a view showing another method used for forming the strip-shaped conductor on the cover glass substrate.

FIG. 11 is a partially cutaway perspective view showing the outer appearance of another embodiment of the present invention.

FIG. 12 is a partially cutaway perspective view showing the outer appearance of another embodiment of the present invention.

FIG. 13 is a partial cross-sectional view showing the configuration of a continuous portion of the thin film EL panel of the same example.

FIG. 14 is a partial cross-sectional view showing the structure of a continuous portion of a conventional EL panel.

FIG. 15 is a partial cross-sectional view showing the configuration of an EL panel of the conventional example.

FIG. 16 is a plan view showing a configuration of an EL panel of the conventional example.

[Explanation of symbols]

 201, 202 ... Thin-film EL panel 21 ... Glass substrate (first insulating substrate) 22 ... Transparent electrode (lower electrode) 24 ... EL light emitting layer 26 ... Upper electrode 27 ... Cover glass substrate (second insulating substrate) 29 ... Strip conductor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takayuki Hiyoshi 6-78 Minamimachi, Mishima City, Shizuoka Prefecture Tokyo Electric Co., Ltd. Technical Research Institute

Claims (3)

[Claims] 1. A thin film in which a plurality of lower electrodes are arranged on a translucent first insulating substrate, and a plurality of upper electrodes are arranged in a matrix on each of the lower electrodes via an EL light emitting layer. A second insulating substrate is provided in which a plurality of thin film EL panels having a light emitting structure are arranged in a row and a plurality of strip-shaped conductors for connecting between the corresponding upper electrodes of each thin film EL panel are formed on one surface side. Then, by covering the thin film EL panels with the second insulating substrate, the strip conductors connect the corresponding electrodes of the thin film EL panels to each other. 2. The thin film EL display according to claim 1, wherein the second insulating substrate is composed of one substrate, and the substrate covers and integrates each thin film EL panel. 3. A thin film in which a plurality of lower electrodes are arranged on a translucent first insulating substrate, and a plurality of upper electrodes are arranged in a matrix on each lower electrode via an EL light emitting layer. A second insulating substrate is provided in which a plurality of thin film EL panels having a light emitting structure are arranged in a row and a plurality of strip-shaped conductors for connecting between the corresponding upper electrodes of each thin film EL panel are formed on one surface side. Then, by covering the thin film EL panels with the second insulating substrate, the strip-shaped conductors connect the corresponding electrodes of the thin film EL panels to each other, thereby insulating the insulating substrates from each other. A thin-film EL display characterized by being filled with resin and cured.