KR100544133B1 - Active addressing flat panel display - Google Patents

Abstract

According to the present invention, an active driving flat panel display is disclosed. The active driving type flat panel display device is formed on a substrate and a substrate, and is formed on a light emitting unit which is driven by a thin film transistor and is stacked in order of a first electrode part, a second electrode part, and an organic film to emit light. And a non-light emitting portion including a thin film transistor and not emitting light, a sealing member disposed to face the substrate and sealing the light emitting portion and the non-light emitting portion, and a spacer interposed between the non-light emitting portion and the sealing member. According to the disclosed active driven flat panel display device, the contact between the sealing member and the electrode part is prevented to improve impact resistance and product reliability, and the support structure inside the display device can be prevented to prevent bending, and the display is enlarged and thinned. A display device suitable for the present invention may be provided.

Description

Active drive flat panel display {Active addressing flat panel display}

1 is a plan view schematically showing the configuration of an active driving flat panel display of the present invention;

2 is a cross-sectional view taken along the line A-A of FIG. 1 showing an active driving flat panel display device according to an exemplary embodiment of the present invention;

3 is a partially enlarged plan view illustrating some subpixels in FIG. 1;

4 is a cross-sectional view taken along line B-B of FIG. 3, showing an active driving type flat panel display device according to another embodiment of the present invention;

5 is a cross-sectional view taken along line B-B of FIG. 3, showing an active driving type flat panel display device according to another embodiment of the present invention;

6A, 6B, 6C, and 6D are plan views illustrating patterns employable in embodiments of the present invention.

<Description of the symbols for the main parts of the drawings>

1: substrate 2: buffer layer

3: first spacer 4: second spacer

10: switching TFT 20: driving TFT

21: semiconductor active layer 22: gate insulating film

23: gate electrode 24: intermediate insulating film

25: source electrode 26: drain electrode

27: passivation film 28: pixel definition film

30: capacitor 40: EL element

41: first electrode portion 42: organic film

43: second electrode portion 53: drive line

112: display area 113: terminal area

121: sealing member 141: drive power supply wiring

142: electrode wiring portion 143, 144: circuit wiring portion

151: vertical circuit portion 152: horizontal circuit portion

P: light emitting part

The present invention relates to an active driving flat panel display device, and more particularly, to an active driving flat panel display device which maintains a constant gap between a sealing member and an electrode part, thereby improving product reliability and making the display device larger and thinner. will be.

A flat panel display such as a liquid crystal display, an organic light emitting display, or an inorganic electroluminescent display is classified into a passive driving type flat panel display device and an active driving type flat panel display device according to its driving method. In the passively driven flat panel display, the anode and the cathode are arranged in columns and rows, respectively, so that the scanning signal is supplied from the row driving circuit to the cathode, wherein only one row of the plurality of rows is provided. Is selected. In addition, a data signal is input to each pixel in the column driving circuit. On the other hand, the active driving flat panel display device is a thin film transistor (TFT) to control the input signal for each pixel, which is suitable for processing a large amount of signals, a lot of display devices for implementing a video It is used.

On the other hand, among the flat panel display devices, an organic light emitting display device uses a transparent glass or plastic plate as a substrate, and forms an organic film by stacking a first electrode portion, a hole transport layer, an organic light emitting layer, an electron transport layer, and the like on top thereof. The second electrode portion is laminated. The laminate formed as described above is sealed with a sealing member, and a predetermined gas is injected into the upper portion to seal the laminate.

In the organic light emitting device having such a structure, when a potential difference is provided between the first electrode part and the second electrode part, holes injected into the hole transport layer and electrons injected into the electron transport layer are recombined in the organic light emitting layer to emit light.

However, the electrode part used in the organic light emitting display device is generally formed by thermal physical vapor deposition, e-beam evaporation, or the like. When pressurized, the electrode portion of the portion is damaged, which ultimately affects product reliability.

On the other hand, the conventional organic light emitting display device does not have a structure that maintains a constant gap between the sealing member and the electrode portion, so that when the external shock or pressure is applied, the electrode portion is pressed by the sealing member and damage is caused to the electrode portion. There is a problem that occurs.

In addition, the conventional organic light emitting display device has a problem in that a bending phenomenon occurs easily due to a weak supporting structure inside the display device.

The above problem is further exacerbated due to the flexibility of the material itself when a synthetic resin is used as the material of the sealing member, thereby increasing the necessity of solving the problem.

The present invention has been made to solve the above problems, to maintain a constant gap between the sealing member and the electrode portion, to improve product reliability, and to provide an active drive flat panel display device suitable for the size and thickness of the display device Its purpose is to.

Another object of the present invention is to provide an active driving type flat panel display device that prevents bending by reinforcing a supporting structure inside the display device.

In order to achieve the above object, the active-driven flat panel display of the present invention

Board;

A light emitting unit which is formed on the substrate and emits light by a light emitting device which is driven by a thin film transistor and is stacked in order of the first electrode unit, the organic layer, and the second electrode unit to emit light;

A non-light emitting part which is formed on the substrate and does not emit light;

A sealing member disposed to face the substrate and sealing the light emitting portion and the non-light emitting portion; And

And a spacer interposed between the non-light emitting portion and the sealing member.

In addition, the non-light emitting part may include the thin film transistor and may be provided to surround the light emitting device.

Further, the non-light emitting part is formed on the thin film transistor and the first electrode part, and includes a pixel defining layer opening a predetermined region on the first electrode part, and the spacer may be disposed on an upper surface of the pixel defining layer.

In addition, the spacer may be integrally formed with the pixel definition layer.

A plurality of light emitting parts may be provided to form a display area, and the non-light emitting part may be provided at an edge of the display area.

In addition, the spacer may be provided by dispersion coating on the upper surface of the second electrode portion.

In addition, the spacer may have a height of 1 μm or more.

In addition, the spacer may be provided in a predetermined pattern.

The predetermined pattern may be one pattern selected from the group consisting of a dot pattern, a grid pattern, a bar pattern, and an uneven pattern.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment according to the present invention.

1 is a plan view schematically showing the configuration of an active driving flat panel display of the present invention, and FIG. 2 is a view showing an active driving flat panel display device according to an exemplary embodiment of the present invention. According to the cross-sectional view.

3 is a partially enlarged plan view illustrating some subpixels in FIG. 1, and FIG. 4 is a cross-sectional view taken along line B-B of FIG. 3, showing an active driving type flat panel display device according to another exemplary embodiment of the present invention. FIG. 5 is a cross-sectional view taken along line B-B of FIG. 3 and showing an active driving type flat panel display device according to another embodiment of the present invention.

In the active driving type organic light emitting display device, as illustrated in FIGS. 1 and 3, the display area 112 including the light emitting part P is disposed at an approximately center portion of the substrate 1 to implement an image. Outside the display area 112, the vertical circuit part 151, the horizontal circuit part 152, the terminal area 113, and the wiring parts 141, 142, 143, and 144 included in the non-light emitting part are disposed. Here, the light emitting portion P is a region where light is emitted by the organic light emitting element 40 (hereinafter referred to as EL element), and the non-light emitting portion is a region excluding the light emitting portion P. It is an area for controlling the light emitting unit P or supplying power. The non-light emitting part may be divided into a first non-light emitting part and a second non-light emitting part, wherein the first non-light emitting part is a non-light emitting part existing in the display area, and the second non-light emitting part is a non-light emitting part existing outside the display area.

The display area 112 is an area where an image is implemented, and is composed of a plurality of subpixels including thin film transistors 10 and 20 and an EL element 40, as shown in FIGS. 3 and 4. The area occupied by the EL element 40 becomes the light emitting portion P which emits light, and the other display areas become the first non-light emitting portion. Above the display region 112, a second electrode portion 43, which is one of the electrode portions of the EL element 40, is disposed, and the second electrode portion 43 is shown in FIG. It is connected to the terminal area 113 on the outside through the electrode wiring part 142 provided on one side of the display area 112. In addition, a plurality of driving lines (VDD) 53 are disposed in the display area 112, and the driving lines 53 are connected to the terminal area through the driving power wiring 141 outside the display area 112. Connected to 113 to supply driving power to the display area 112.

The outside of the display area 112 includes a vertical circuit part 151 and a horizontal circuit part 152 for inputting signals to the thin film transistors 10 and 20 of the display area 112. 143, 144 is connected to the terminal area 113.

1 and 2, the sealing member 121 seals the entire region excluding the display region 112 and the terminal regions 113 such as the wiring portions 141, 142, 143 and 144 and the circuit portions 151 and 152. Done.

In the present invention, the second non-light emitting portion is the entire region except for the display region 112 inside the sealing member 121.

In the active driving flat panel display, according to an aspect of the present invention, a spacer is interposed between the non-light emitting portion and the sealing member 121 that do not emit light. For example, as shown in FIG. 2, the second spacer 4 may be interposed on an upper surface of the driving power wiring 141 and the vertical circuit unit 151. Since the arrangement of the second spacer 4 can be considered as long as it is a region that does not interfere with the light transmission of the EL element 40, the second non-light emitting portion except for the display region 112 among the regions sealed by the sealing member 121. May be interposed. Accordingly, the present invention is not limited to the above-described driving power wiring 141 and the vertical circuit 151, and may be interposed in the horizontal circuit 152 and other wirings 142, 143, and 144.

Meanwhile, as shown in FIG. 2, the second spacer 4 may be attached to the top surface of the driving power wiring 141 and the vertical circuit unit 151. The second spacer 4 may be provided in a different shape in addition to the spherical shape, which may be determined in consideration of the supporting strength supported by the second spacer 4, the area in which the second spacer 4 is in contact, and the like. For example, when formed only outside the display area 112, that is, only on the upper surfaces of the wiring parts 141, 142, 143 and 144 or the circuit parts 151 and 152, the supporting strength required for the second spacer 4 is not only outside the display area 112. The first spacer 3 inside the display area 112 should be larger than the case where the first spacer 3 is provided, and in consideration of the deformation of the sealing member 121, the height of the second spacer 4 is also relatively increased.

In consideration of the supporting structure, the second spacer 4 may be, for example, a cross structure when four directions of support are required, and a trapezoidal structure may be used when the contact area is limited. As the material of the second spacer 4, glass or ceramic may be adopted, and the adhesive second spacer 4 coated with a thermosetting resin or a UV curing resin on the surface of the second spacer 4 may be used. It may be.

Of course, the second spacer 4 may be provided by other methods described below in addition to the joining method.

As shown in FIG. 3, each sub-pixel of the active driving type organic light emitting display device of the present invention includes a switching TFT 10, a thin film transistor such as a driving TFT 20, and a capacitor 30. ) And one EL element 40. However, the number of the thin film transistors 10 and 20 and the capacitor 30 is not necessarily limited thereto, and the thin film transistors 10 and 20 and the capacitor 30 have a larger number depending on the design of the desired device. can do.

The switching TFT 10 is driven by a scan signal applied to the gate line 51 to transfer a data signal applied to the data line 52. The driving TFT 20 determines the amount of current flowing into the EL element 40 by the voltage difference Vgs between the gate and the source in accordance with the data signal transmitted through the switching TFT 10. The capacitor 30 stores a data signal transmitted through the switching TFT 10 for one frame.

Referring to FIG. 4, a buffer layer 2 is formed on an insulative substrate 1, and a light emitting part P and a first non-light emitting part are provided on the buffer layer 2. Here, the light emitting unit P refers to a region where the EL element 40 is formed to emit light, and the first non-light emitting unit refers to a region excluding the light emitting unit P in the display region 112. The first non-light emitting portion NP is mainly an area for controlling or supplying power to the EL element 40. In FIG. 4, only an area in which the driving TFT 20 and the capacitor 30 are formed is shown. The region except for the light emitting portion P, for example, includes all of the region where the switching TFT 10 is formed.

As shown in FIG. 4, the driving TFT 20 includes a semiconductor active layer 21 formed on the buffer layer 2, a gate insulating film 22 formed on the semiconductor active layer 21, and a gate insulating film 22. Has a gate electrode 23 thereon.

The semiconductor active layer 21 may be formed of an amorphous silicon thin film or a polycrystalline silicon thin film. This semiconductor active layer has source and drain regions doped with N-type or P-type impurities at a high concentration.

The gate insulating film 22 is provided on the semiconductor active layer 21 by SiO2 or the like, and the gate electrode 23 is formed by MoW, Al / Cu, or the like on a predetermined region of the gate insulating film 22. The gate electrode 23 is connected to the first electrode 31 of the capacitor 30 to supply a TFT on / off signal and is formed on the channel region of the semiconductor active layer 21.

An intermediate insulating layer 24 is formed on the gate electrode 23, and the source electrode 25 and the drain electrode 26 are in contact with the source region and the drain region of the semiconductor active layer 21 through contact holes. do. The source electrode 25 is connected to the driving line 53 to supply a reference common voltage for driving the semiconductor active layer 21, and the drain electrode 26 supplies the driving TFT 20 and the EL element 40. By connecting, the driving power is applied to the EL element 40. The drive line 53 is connected to the second electrode 32 of the capacitor 30.

A passivation film 27 made of SiO 2 or the like is formed on the source and drain electrodes 25 and 26, and an EL element connected to the drain electrode 26 by a contact hole is formed on the passivation film 27. The first electrode portion 41 of 40 is formed.

The EL element 40 emits red, green, and blue light in accordance with the flow of current to display predetermined image information. As shown in FIG. 4, the drain electrode 25 of the driving TFT 20 is shown. A first electrode portion 41 connected to the second electrode portion 41 to function as an anode electrode, a second electrode portion 43 provided to cover the entire pixel, and serving as a cathode electrode, and the first electrode portion 41 and the first electrode portion 41; It consists of the organic film 42 arrange | positioned between 2 electrode parts 43, and light-emits. At this time, the first electrode part 41 can be used as a cathode and the second electrode part 43 can be used as an anode.

On top of the first electrode portion 41 formed by ITO or the like, a pixel definition film 28, for example, a planarization film is formed of acryl or the like, and a predetermined opening 28a is formed in the pixel definition film 28. Thereafter, the organic film 42 and the second electrode portion 43 serving as the cathode are sequentially formed in the opening 28a.

The organic layer 42 may be a low molecular or high molecular organic layer. When the low molecular organic layer is used, a hole injection layer (HIL), a hole transport layer (HTL), and an organic emission layer (EML) may be used. , An electron transport layer (EIL), an electron injection layer (ETL), or the like may be formed by stacking a single or a composite structure.In the case of a polymer organic film, a hole transport layer (HTL) and a light emitting layer ( EML) may have a structure provided.

The second electrode portion 43, which is the cathode electrode, is formed by depositing the entire surface with Al / Ca, etc. in the case of the bottom emission type emitting light toward the substrate 1, and in the case of the top emission type emitting light toward the sealing member 121, such as Mg-Ag. After forming a thin semi-permeable thin film by metal, transparent ITO is formed thereon.

In this way, after the second electrode portion 43 is formed, the sealing member 121 is bonded to the upper surface and sealed. Here, in order to protect the organic film 42 and the electrode portions 41 and 43 from moisture and oxygen, a space such as nitrogen is filled in the space formed by the substrate 1 and the sealing member 121 to be larger than atmospheric pressure. do.

As described above, according to one feature of the present invention, a spacer is interposed between the non-light emitting portion and the sealing member 121 that do not emit light. As shown in FIG. 4, the first spacer 3 may be interposed in the first non-light emitting portion in the display area 112.

For example, the first spacer 3 may be disposed on the upper surface of the pixel definition layer 28 formed on the driving TFT 20. In this case, as shown, the first spacer 3 may be integrally formed with the pixel defining layer 28. The first spacer 3 may be provided by a photolithography method commonly used for forming the pixel definition layer 28. The photolithography method is a method of coating a photoresist, exposing and developing the photoresist through a photomask having a desired pattern, baking the same, and etching the batch to form a pattern. In the photolithography method, a part of the photoresist in the portion forming the pattern is removed by adjusting the transmittance of the photomask so that the amount of light exposed is different. Therefore, the stepped pixel defining layer 28 having the first spacer 3 integrally formed can be formed.

Of course, in the illustrated embodiment, the cross section of the first spacer 3 is formed in a polygon, but may be provided in various shapes.

In addition, the first spacer 3 may be stacked on the pixel defining layer 28. The first spacer 3 may be provided by a conventional layering process, for example, a photolithography method. In addition, the shape may be provided in various shapes including the polygon shown.

As shown in FIG. 5, the first spacer 3 may be formed by being bonded to the upper surface of the second electrode part 43. The first spacer 3 may be formed of glass or ceramic. The shape of the first spacer 3 to be bonded may include the support strength of the first spacer 3 supporting the sealing member 121, the contact area of the second electrode portion 43 contacting the first spacer 3, and the like. Can be determined in consideration of this. That is, when a high supporting strength is required, it may be a cross structure capable of supporting in four directions, and may be provided in a trapezoidal structure when the contact area of the first spacer 3 is limited.

The first spacer 3 may be integrally formed and bonded with a connecting member (not shown) therebetween. In this case, since the first spacer 3 may be integrally handled, the process may be easily performed.

In order to adhere the first spacer 3 to the second electrode part 43, a photosensitive adhesive material may be used. That is, when the photosensitive adhesive material is applied onto the second electrode portion 43 and the adhesive material of the portion where the first spacer 3 is not positioned is removed through exposure, the first spacer 3 is the photosensitive adhesive material. Can be glued depending on. In this case, a photoresist such as polyimide may be used as the adhesive layer.

In the above embodiment, the second electrode portion 43 can be protected by further forming a protective film (not shown) on the upper surface. The protective film may be formed using an inorganic material or an organic material.

In addition, the first spacer 3 may be applied to the upper surface of the second electrode part 43. As the material of the first spacer 3, a polymer, micro pearl, silica, or the like may be adopted, and the adhesive first spacer 3 coated with a thermosetting resin or a UV curing resin on the surface of the first spacer 3 may be used. ) May be used.

The first spacer 3 may be uniformly arranged in a predetermined pattern. That is, as shown in FIGS. 6A, 6B, 6C, and 6D, the first spacer 3 may be provided in various shapes including a pattern such as a rod, a lattice, and an uneven shape.

In addition, although the above-described first spacer 3 may be formed in various sizes according to the gap of the space into which the gas is to be injected, the height of the first spacer 3 may be 1 μm or more.

In the organic light emitting display device configured as described above, when a predetermined voltage is applied to the first electrode portion 41 and the second electrode portion 43, holes are injected from the first electrode portion 41, which is an anode. The organic light emitting layer 42 is moved to the organic light emitting layer 42, and electrons are injected into the organic light emitting layer 42 from the second electrode part 43. In this organic light emitting layer 42, electrons and holes recombine to generate excitons, and as the excitons change from the excited state to the ground state, the fluorescent molecules of the organic light emitting layer 42 emit light to form an image.

In the active type flat panel display device driven as described above, spacers 3 and 4 are interposed between the non-light emitting part and the sealing member 121 so that the distance between the sealing member 121 and the second electrode part 43 is constant. maintain. Therefore, it is possible to prevent the second electrode portion 43 from being damaged by the pressurization of the sealing member 121, and the supporting structure inside the display device is strengthened to prevent bending. Therefore, an active drive flat panel display device suitable for large and thin display devices is provided.

According to the active driving flat panel display of the present invention configured as described above, the following effects can be obtained.

First, the gap between the sealing member and the second electrode portion is kept constant. Therefore, damage to the electrode portion due to pressurization of the sealing member can be prevented even under external impact or pressure, and the reliability of the product is improved.

Second, the support structure inside the display device is strengthened by a spacer interposed between the non-light emitting portion and the sealing member. Therefore, bending of the display device can be prevented and a flat structure can be maintained.

Third, as described above, an organic light emitting display device suitable for increasing the size and thickness of a display may be provided by securing stability and preventing bending of the second electrode unit.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Could be. Accordingly, the true scope of protection of the invention should be defined by the appended claims.

Claims (10)

delete delete delete Board; A light emitting part formed on the substrate and driven by a thin film transistor and emitting light by a light emitting element including a first electrode part, an organic film, and a second electrode part; A non-light emitting part which is formed on the substrate and does not emit light; A sealing member disposed to face the substrate and sealing the light emitting portion and the non-light emitting portion; And And a spacer interposed between the non-light emitting portion and the sealing member. The non-light emitting part is formed on the first electrode part and the thin film transistor, and includes a pixel defining layer that opens a predetermined area on the first electrode part, and the spacer is disposed on an upper surface of the pixel defining layer. Driven flat panel display. The method of claim 4, wherein And the spacer is integrally formed with the pixel defining layer. Board; A light emitting part formed on the substrate and driven by a thin film transistor and emitting light by a light emitting element including a first electrode part, an organic film, and a second electrode part; A non-light emitting part which is formed on the substrate and does not emit light; A sealing member disposed to face the substrate and sealing the light emitting portion and the non-light emitting portion; And And a spacer interposed between the non-light emitting portion and the sealing member. And a plurality of light emitting parts to form a display area, and wherein the non-light emitting part is provided outside the display area. Board; A light emitting part formed on the substrate and driven by a thin film transistor and emitting light by a light emitting element including a first electrode part, an organic film, and a second electrode part; A non-light emitting part which is formed on the substrate and does not emit light; A sealing member disposed to face the substrate and sealing the light emitting portion and the non-light emitting portion; And And a spacer interposed between the non-light emitting portion and the sealing member. And the spacers are dispersed and coated on an upper surface of the second electrode part. delete delete The method according to any one of claims 4, 6 or 7, And the spacer is formed in one pattern selected from the group consisting of a dot pattern, a grid pattern, a bar pattern, and an uneven pattern.

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