KR20090021712A - Organic light emitting diode - Google Patents

Abstract

An organic electroluminescent device is provided to improve electric property of an electrode layer formed on a top of a spacer and a top of a sub pixel by dividing the spacer into a bar shape. An organic electroluminescent device comprises a plurality of sub pixels and a spacer(140). A plurality of sub pixels is arranged on a substrate into a matrix shape. The spacer is arranged between the sub pixels into a bar shape. A longitudinal direction width of the spacer is 6.5% ~ 25.2% of a longitudinal direction width of the sub pixel. The spacer is divided on the same line. A divided spacer has the same length or has a different length. A length ratio of the divided spacer is 10% ~ 90% of a length of three sub pixels including a non-emitting region. Three sub pixels are positioned on a line like the divided spacer.

Description

Organic Light Emitting Diode

The present invention relates to an organic electroluminescent device.

An organic light emitting display device used in an organic light emitting display device is a self-light emitting device in which a light emitting layer is formed between two electrodes positioned on a substrate.

In addition, the organic light emitting device has a top emission type and a bottom emission type according to the direction in which light is emitted, and a passive matrix type and an active matrix type according to the driving method. Active Matrix).

In general, organic light emitting diodes are fabricated through an anode patterning process, an insulating film process, organic material and cathode deposition, and a passivation and encapsulation process on a substrate.

In this manufacturing process, some of the spacers for various purposes such as the support role of the metal mask, the support role of the sealing member and the like are formed on the substrate. Currently, spacers can also achieve the purpose of preventing stress due to external air or external pressure, and thus the frequency of applying the spacers is increasing.

On the other hand, as described above, although a variety of purposes can be achieved, the conventional spacer was not clearly formed to improve the purpose or effect of use.

As a result, during the manufacturing process, the mask applies an impact or scratch to the organic light emitting layer in the subpixel, causing a problem of increasing the defect rate or deteriorating the uniformity of the deposited thin film.

An object of the present invention for solving the above problems of the background art is to provide a spacer that can effectively perform a variety of purposes in the manufacturing process of the organic light emitting device to improve the production yield as well as to improve the reliability.

The present invention as a means for solving the above problems, the present invention comprises: a plurality of subpixels positioned in a matrix form on a substrate; It includes a spacer disposed in the form of a bar (bar) between the plurality of sub-pixels, wherein the longitudinal width (X) of the spacer is 6.5% to 25.2% compared to the wide vertical width (Z) of the sub-pixel to provide an organic light emitting device do.

The spacers are divided to be spaced apart from each other on the same line by a predetermined interval, and the divided spacers may be divided into the same or different lengths.

The length ratio of each of the divided spacers may be 10% to 90% of the length of the three subpixel areas positioned on the same line and including the non-light emitting area.

The divided spacers may be positioned such that the region of one first spacer positioned in the nth row and the region of one second spacer positioned in the n−1 th row partially overlap each other.

The spacers may be formed differently in one or more of height, angle or width depending on the position of the substrate.

The spacer may be positioned on an insulating layer that divides the subpixels.

The plurality of subpixels may include one or more transistors, capacitors, and organic light emitting diodes positioned on the substrate.

Two or more of the spacers may be connected end to end with one another.

The present invention is to provide a spacer that can effectively perform a variety of purposes in the manufacturing process of the organic light emitting device to improve the production yield as well as to improve the reliability.

Hereinafter, with reference to the accompanying drawings will be described a specific content for the practice of the present invention.

1A is a schematic diagram of an organic light emitting display device according to an embodiment of the present invention, and FIG. 1B is a schematic view of an organic light emitting display device according to another embodiment of the present invention.

In the organic light emitting diode illustrated in FIG. 1A, a plurality of sub pixels 120 may be positioned on the substrate 110. Here, the substrate 110 may be selected as a member for forming an element having excellent mechanical strength and dimensional stability.

As the material of the substrate 110, a glass plate, a metal plate, a ceramic plate or a plastic plate (polycarbonate resin, acrylic resin, vinyl chloride resin, polyethylene terephthalate resin, polyimide resin, polyester resin, epoxy resin, silicone resin, fluorine) Resin, etc.) is mentioned.

Here, when the organic light emitting diode is a passive matrix type, the organic light emitting layer may be positioned between the anode and the cathode positioned on the substrate 110 in the subpixel 120.

On the other hand, when the organic light emitting diode is an active matrix type, the subpixel 120 may have an organic light emitting layer positioned between an anode and a cathode connected to a source or drain electrode of a driving transistor included in a transistor array on the substrate 110. Can be. Here, the transistor array may include one or more transistors and capacitors.

The red, green, and blue subpixels 120R, 120G, and 120B may be defined as one unit pixel. In the illustrated drawing, one subpixel 120 is represented as including only red, green, and blue. However, this is only an example of an embodiment, and the subpixel 120 may further include four or more light emitting colors such as white, and may emit other colors (for example, orange, yellow, etc.). have.

Here, the subpixel 120 may include at least an organic emission layer. The organic light emitting layer may further include at least one of a hole injection layer, a hole transport layer, an electron transport layer, or an electron injection layer. In addition, the organic emission layer may further include a buffer layer, a blocking layer, and the like to control the flow of holes or electrons between the anode and the cathode. It may be.

On the other hand, the transistor can be largely divided into a switching transistor for switching the scan signal and a driving transistor for driving the data signal.

In addition, the organic light emitting display device may display a desired image by emitting light of a sub-pixel selected by a data signal and a scan signal supplied from the outside.

Hereinafter, the cross-sectional structure will be described in more detail with an example that the sub-pixel is an active matrix type.

2 is a cross-sectional view of a subpixel.

Referring to FIG. 2, a buffer layer 111 may be located on the substrate 110. The buffer layer 111 may be formed to protect the thin film transistor formed in a subsequent process from impurities such as alkali ions flowing out of the substrate 110. The buffer layer 111 may use silicon oxide (SiO ₂ ), silicon nitride (SiNx), or the like.

The semiconductor layer 112 may be positioned on the buffer layer 111. The semiconductor layer 112 may include amorphous silicon or polycrystalline silicon obtained by crystallizing the same. Although not shown here, the semiconductor layer 112 may include a channel region, a source region, and a drain region, and the source region and the drain region may be doped with P-type or N-type impurities.

The gate insulating layer 113 may be positioned on the substrate 110 including the semiconductor layer 112. The gate insulating layer 113 may be selectively formed using silicon oxide (SiO ₂ ), silicon nitride (SiNx), or the like.

The gate electrode 114 may be positioned on the gate insulating layer 113 to correspond to the channel region of the semiconductor layer 112. The gate electrode 114 includes aluminum (Al), aluminum alloy (Al alloy), titanium (Ti), silver (Ag), molybdenum (Mo), molybdenum alloy (Mo alloy), tungsten (W), tungsten silicide (WSi). It may include any one of ₂ ).

An interlayer insulating film 115 may be positioned on the substrate 110 including the gate electrode 114. The interlayer insulating film 115 may be an organic film or an inorganic film, or may be a composite film thereof.

When the interlayer insulating film 115 is an inorganic film, the interlayer insulating film 115 may include silicon oxide (SiO ₂ ), silicon nitride (SiNx), or SOG (silicate on glass). On the other hand, the organic film may include an acrylic resin, a polyimide resin or a benzocyclobutene (BCB) resin. First and second contact holes 115a and 115b may be disposed in the interlayer insulating layer 115 and the gate insulating layer 113 to expose a portion of the semiconductor layer 112.

The first electrode 116a may be positioned on the interlayer insulating film 115. The first electrode 116a may be an anode and may include a transparent conductive layer such as indium tin oxide (ITO) or indium zinc oxide (IZO), and the first electrode 116a may have a stacked structure such as ITO / Ag / ITO. It can have

Source and drain electrodes 116b and 116c may be positioned on the interlayer insulating film 115. The source electrode and the drain electrode 116b and 116c may be electrically connected to the semiconductor layer 112 through the first and second contact holes 115a and 115b. A portion of the drain electrode 116c may be positioned on the first electrode 116a and electrically connected to the first electrode 116a.

The source and drain electrodes 116b and 116c may include a low resistance material to lower the wiring resistance. The source and drain electrodes 116b and 116c may be a multilayer film made of molybdenum (Mo), molybdenum tungsten (MoW), titanium (Ti), aluminum (Al), or an aluminum alloy (Al alloy). A multilayer structure of titanium / aluminum / titanium (Ti / Al / Ti) or molybdenum / aluminum / molybdenum (Mo / Al / Mo) or molybdenum tungsten / aluminum / molybdenum tungsten (MoW / Al / MoW) may be used. . However, the multilayer film is not limited thereto.

The transistor located on the ideal substrate 110 may include a gate electrode 114, a source electrode, and a drain electrode 116b and 116c, and a transistor array having a plurality of transistors and capacitors may be electrically connected to the following organic light emitting diodes. have. (However, the structure of the capacitor is omitted)

An insulating layer 117 exposing a portion of the first electrode 116a may be disposed on the first electrode 116a (eg, an anode). The insulating layer 117 may include an organic material such as benzocyclobutene (BCB) resin, acrylic resin, or polyimide resin.

The organic light emitting layer 118 may be disposed on the exposed first electrode 116a, and the second electrode 119 (eg, a cathode) may be positioned on the organic light emitting layer 118. The second electrode 119 may be a cathode for supplying electrons to the organic light emitting layer 118, and may include magnesium (Mg), silver (Ag), calcium (Ca), aluminum (Al), or an alloy thereof. have.

The organic light emitting diode connected to the source or drain electrodes 116b and 116c of the transistor array on the ideal substrate 110 includes a first electrode 116a, an organic light emitting layer 118, and a second electrode 119. can do.

However, the first electrode 116a positioned on the source electrode or the drain electrodes 116b and 116c of the transistor array may be positioned on a planarization film that planarizes the surface of the transistor array. In addition, the structure of the transistor array may vary depending on whether it is a top gate or a batam gate. In addition, their structures may vary depending on the number of masks and semiconductor material used to form the transistor array. Therefore, the structure of the subpixel is not limited thereto.

Referring back to FIG. 1A, a spacer 140 is positioned between a plurality of sub pixels 120 positioned in a matrix on the substrate 110.

As shown in FIG. 2, the spacer 140 may be divided and positioned in a bar shape to intersect between rows between the subpixels 120 on the insulating layer 117 separating the subpixels 120. have. When the spacer 140 is divided and positioned as described above, electrical characteristics of the electrode layer formed on the spacer 140 and the subpixel 120 may be improved. This is because the electrode layer is uniformly formed between the divided spaces, thereby improving the step coverage. In addition, the divided spacer 140 may be positioned to partially overlap an area of one first spacer positioned in an nth row and an area of one second spacer located in an n−1th row. That is, the divided spacer 140 may be disposed in a zigzag form or a zigzag form on the substrate 110. When the divided spacer 140 is positioned in such a shape, the metal mask may be prevented from sagging in a specific area.

In addition, the spacer 140 may be positioned in a bar shape to cross the rows as shown in FIG. 1B. When the spacer 140 is positioned in this manner, it may give an easy process in forming the spacer 140.

Hereinafter, the cross-sectional structure of the spacer is attached and described in more detail.

3 is a cross-sectional view of the spacer.

Referring to FIG. 3, the spacer 140 used in the present invention may have a forward taper shape in which a lower portion of the spacer 140 facing the insulating layer 117 is wider than an upper portion thereof.

The spacer 140 may be formed to have a proper shape to perform various purposes such as a supporting role of a metal mask, a supporting role of a sealing member including a role of preventing stress due to external air or external pressure, etc. in the manufacturing process of the organic light emitting diode. have.

4 is an enlarged view of a partial region of FIG. 1A.

As illustrated in FIG. 4, the spacers 140 formed in a bar shape to cross the rows between the subpixels 120 may be divided into the same or different lengths so as to be spaced apart from each other on the same line.

Here, when the length (a) of one spacer 140 is formed at a ratio of 10% or more to the length (b) of the three sub-pixel areas located on the same line, it is possible to prevent the area where the metal mask sags. Can be. Here, as the length (a) of the spacer 140 is smaller, the zigzag arrangement of the spacer 140 may prevent the metal mask from sagging. When the length (a) of one spacer 140 is formed at a ratio of 90% or less with respect to the length (b) of three subpixel regions positioned on the same line, an electrode layer, which is an advantage of the structure of the divided spacer 140. It is possible to increase the length of the spacer 140 within the range that the improvement of the electrical characteristics is not lost.

Accordingly, the ratio of the length (a) of one spacer 140 may be in a range of 10% to 90% of the length (b) of the three sub-pixel areas located on the same line and including the non-light emitting area. Here, the three subpixel regions including the non-light emitting region may include an insulating layer positioned between the subpixel and the subpixel.

Meanwhile, the spacer 140 may set an appropriate width to serve as a support for the sealing member in the manufacturing process.

To this end, the width of the spacer 140 may be designed in consideration of the size of the sub-pixel 120. In this case, the width of the spacer 140 may be formed at a ratio of the range of the wide vertical width Z of the sub-pixel 120.

From this point of view, when the ratio of the longitudinal width X of the spacer 140 is 6.5% or more to the longitudinal width Z of the sub-pixel 120, the spacer 140 may serve as a support. Can provide enough foundation. " When the ratio of the longitudinal width X of the spacer 140 is 25.2% or less with respect to the longitudinal width Z of the sub-pixel 120, the spacer 140 may be decomposed by external pressure even if the spacer 140 collapses due to external pressure. Can be prevented from being adversely affected by the contact with the sub-pixel 120 adjacent to the 140. "

Therefore, in consideration of the width that the spacer 140 can serve as a support and the impact on the subpixel 120 during collapse, the spacer 140 has a lengthwise width X of 6.5 compared to the wide vertical width Z of the subpixel. It may be formed to have a range of% to 25.2%.

On the other hand, in the above description, the spacer 140 may take advantage of this by forming one or more of height, angle, or width differently according to the position of the substrate 110.

5 is an enlarged view of a portion of a spacer according to a modified embodiment of the spacer, and FIG. 6 is a schematic view of an organic light emitting diode according to a modified embodiment of the spacer.

Referring to FIG. 5, the spacer 140 may minimize the influence on the height or width, such as the first or second spacer 140a, in consideration of the possibility that an external pressure may be largely applied in a specific region. . In addition, although not shown in the drawings, the taper angle of the spacer 140 may be reduced or increased in consideration of the possibility that the shadow region caused by the metal mask in the specific region may be largely compensated for.

In addition, referring to FIG. 6, the spacer 140 may perform at least two of the spacers 140 disposed on the substrate 110 to perform a role of preventing stress due to external pressure as well as preventing moisture permeation by external air. Of course, the end and the end of the spacer 140 may be connected to each other.

The present invention is to provide a spacer that can effectively perform a variety of purposes in the manufacturing process of the organic light emitting display device to improve the production yield as well as to improve the reliability.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention described above may be modified in other specific forms by those skilled in the art to which the present invention pertains without changing its technical spirit or essential features. It will be appreciated that it may be practiced. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is shown by the claims below, rather than the above detailed description. Also, it is to be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

1A is a schematic diagram of an organic light emitting display device according to an embodiment of the present invention.

1B is a schematic view of an organic light emitting display device according to another embodiment of the present invention.

2 is a cross-sectional view of a subpixel.

3 is a cross-sectional view of the spacer.

4 is an enlarged view of a partial region of FIG. 1A;

5 is an enlarged view of a partial area according to a modified embodiment of the spacer.

6 is a schematic view of an organic light emitting display device according to a modified embodiment of the spacer.

<Explanation of symbols on main parts of the drawings>

110: substrate 117: insulating film

120: subpixel 140: spacer

Claims (8)

A plurality of subpixels positioned in a matrix form on the substrate; It includes a spacer disposed in the form of a bar (bar) between the plurality of sub-pixels, The lengthwise width X of the spacer is 6.5% to 25.2% of the wide vertical width Z of the subpixel. The method of claim 1, The spacer, It is divided so as to be spaced apart from each other on the same line. The divided spacers are organic light emitting diodes that are divided into the same or different lengths. The method of claim 2, Length ratio of the divided spacers, An organic light emitting display device having 10% to 90% of the length of three subpixel areas located on the same line and including a non-light emitting area. The method of claim 2, The divided spacers, An organic light emitting diode positioned in such a way that an area of one first spacer located in an nth row and an area of one second spacer located in an n−1th row partially overlap each other. The method of claim 1, The spacer, At least one of a height, an angle, or a width is formed differently according to the position of the substrate. The method of claim 1, The spacer, An organic light emitting diode disposed on an insulating layer for separating the subpixels. The method of claim 1, The plurality of subpixels, An organic light emitting device comprising at least one transistor, a capacitor and an organic light emitting diode positioned on the substrate. The method of claim 1, At least two of the spacers, An organic light emitting device having a terminal and a terminal connected to each other.

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