JP2003249354A - Method of manufacturing organic el display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an organic EL display panel, enabling the formation of a sealing film in such a manner as to expose the connection part of an electrode while reducing the manhours. <P>SOLUTION: When a plurality of organic EL display panels 11 is manufactured from one substrate 20, a plurality of display parts 13 is formed on the substrate 20 and then a polyimide tape 23 is pasted to the substrate 20. The polyimide tape 23 is formed in a size corresponding to that of the substrate 20 and holes 24 are formed therein at positions corresponding to those of the display parts 13, and the display parts 13 are exposed via the holes 24. The connection parts 14a of the electrodes 14 and cutlines 21 are covered with the polyimide tape 23. The substrate 20 is put in a deposition device in the state of pasting the polyimide tape 23 thereto and a thin film 16 is formed by a plasma CVD. Then, after it is irradiated with a ultraviolet ray for reducing the adhesive force of an adhesive, the polyimide tape 23 is removed until the connection parts 14a of the electrodes 14 and the cutlines 21 are exposed. Then, the substrate 20 is cut at the cutlines 21. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an organic electroluminescence (hereinafter, simply referred to as "organic EL") display panel, and more particularly, to a sealing film (thin film) for shielding an organic EL element from the outside air. The present invention relates to a method for manufacturing an organic EL display panel including a stop film forming step.

[0002]

2. Description of the Related Art Organic EL elements of organic EL display panels are
An organic EL layer is formed between the anode and the cathode. Since organic EL materials have high reactivity with oxygen and moisture, unless they are used in a state in which they are shielded from the outside air, chemical degradation occurs due to oxygen and moisture in the atmosphere, and dark spots and dark areas called non-luminous regions expand. There is a problem. As a method for shutting off the organic EL layer from the outside air, a stainless steel or glass sealing cover (sealing can) is provided on the substrate via an adhesive and is adsorbed in the sealing cover as a practical method. There is a configuration in which an agent is contained and sealed.
As shown in FIG. 5, this is provided with a display section 52 having an organic EL element on the surface of a glass substrate 51, and an electrode 53 extending outward from the display section 52, and encapsulating the display section 52 in a covered state. The cover 54 is adhered to the glass substrate 51 with an adhesive 55. A part of the sealing cover 54 is placed on the electrode 53 via the adhesive 55. A non-illustrated adsorbent (drying agent) is contained in the sealing cover 54. The adhesive 55 may be a thermosetting resin or a photocurable resin. As an organic EL display panel sealed with a sealing can in this way, there is one disclosed in, for example, JP-A-5-109482.

[0003]

In the present configuration,
Almost no moisture or oxygen intrudes from the cover body, but moisture or oxygen invades from the adhesive 55 part, so it is not possible to completely prevent intrusion of moisture or oxygen from the outside, and a stable and long life is achieved. Is not working. There is also a problem that the sealing structure becomes thick.

As a method of sealing the organic EL element, a method of sealing the organic EL element with a thin film of silicon nitride or silicon oxide has also been disclosed (for example, Japanese Patent Laid-Open No. 2000-223).
No. 264). Such a thin film is formed by vapor deposition such as plasma CVD.

It is necessary to expose the connecting portion of the electrode to be connected to other wiring from the thin film. In order to expose the connection part of the electrode, a method of masking by disposing a metal mask at a predetermined position in the vapor deposition device so that the connection part is not sealed by the thin film at the time of forming the thin film can be considered. It is also possible to deposit a thin film on the entire substrate and partially remove the thin film by a photolithography process and an etching process to expose the connection part.

However, since it is difficult to dispose the substrate at a predetermined position in the vapor deposition apparatus so as to correspond to the metal mask in the vapor deposition apparatus, there is a problem that the metal mask cannot be used. In addition, the method of vapor-depositing a thin film on the entire substrate and partially removing the thin film by a photolithography process and an etching process has a problem that it takes many steps.

The present invention has been made in view of the above circumstances, and an object thereof is to manufacture an organic EL display panel in which the number of steps is reduced and a sealing film can be formed so as to expose a connection portion of an electrode. To provide a method.

[0008]

In order to achieve the above-mentioned object, in the invention according to claim 1, an organic display device having an organic EL element and electrodes extending from the display device are provided on a substrate. A sealing film forming step of forming a sealing film for sealing the display portion of the EL display panel is provided. Then, in the step of forming the sealing film, the sealing film is formed in a state in which a mask member that masks at least a connection portion of the electrode with another wiring is arranged on the substrate, and then the mask member is removed.

In the present invention, unlike the case where a metal mask is used, since the mask member is arranged on the substrate, the total thickness can be made to be about the same as when the mask member is not provided, which makes it easy to handle. It can be put in the vapor deposition device for the sealing film without any problem. Further, the number of steps can be reduced as compared with the case where the sealing film is formed on the entire substrate and the sealing film at the electrode connecting portion is removed.

According to a second aspect of the invention, in the first aspect of the invention, a cut line for cutting out the organic EL display panel is formed on the substrate, and the cut line of the substrate is formed by the mask member. The sealing film is formed in a state where it is also masked. For example, if the substrate is cut at the portion where the sealing film is formed, the sealing film may crack.
However, in the present invention, the substrate can be cut without the sealing film on the cut line by arranging and removing the mask member, so that cracking of the sealing film can be prevented.

According to the invention of claim 3, in the invention of claim 1 or 2, the mask member is an adhesive tape. In the present invention, since the adhesive tape is easy to handle, the mask member is easier to handle than, for example, the case of applying a resin to mask.

According to a fourth aspect of the invention, in the invention according to any one of the first to third aspects, the mask member is removed after the treatment for reducing the adhesive strength of the adhesive. For example, if the adhesive force is too strong, the electrode may peel off from the substrate when removing the mask member. On the other hand, if the adhesive strength is too weak, the mask member may be displaced or partly peeled off during the process, and the electrode connection portion may not be sufficiently masked. In addition, since the adhesive may remain on the connecting portion of the substrate or the electrode, it is difficult to adjust the adhesive force. However, in this invention,
Since it is not necessary to adjust the adhesive force, it is possible to attach the mask member to the substrate with sufficient adhesive force.

According to a fifth aspect of the invention, in the invention according to the fourth aspect, the treatment for reducing the adhesive strength of the adhesive is irradiation with ultraviolet rays. In the present invention, the adhesive strength of the adhesive can be easily reduced.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is embodied in a method of manufacturing a two-division scanning type organic EL display panel by a passive matrix driving system will be described with reference to FIGS.

FIG. 1C shows a partial schematic sectional view of an organic EL display panel. 2 is a schematic plan view showing a state in which a polyimide tape is attached, and FIG. 1 (a) is an IA-I of FIG.
A partial schematic cross-sectional view taken along the line A is shown, and FIG. 1B shows a partial schematic cross-sectional view in a state where a thin film is formed. 1A to 1
In FIG. 2C, the thickness ratio of each member is not accurate because it is illustrated for easy understanding, and the number of electrodes is smaller than the actual number in FIG.

As shown in FIG. 1 (c), the organic EL display panel 11 has an organic EL display panel 11 on a glass substrate 12 as a substrate.
A display unit 13 including an L element, and electrodes 14 and 15 that form the display unit 13 and extend outward from the display unit 13.
(The electrode 15 is shown in FIG. 2). In this embodiment, the electrode 14 is a cathode (scan electrode), the electrode 15 is an anode (data electrode), and the electrodes 14 and 15 are each formed in a plurality of parallel stripes. The organic EL element is formed by sequentially stacking an electrode 15 (anode), an organic EL layer as a light emitting layer, and an electrode 14 (cathode) on a glass substrate 12. The organic EL layer has, for example, a well-known structure, and is composed of three layers, that is, a hole injection layer, a light emitting layer, and an electron injection layer in order from the glass substrate 12 side.

The organic EL display panel 11 is a two-division scanning type, and the rectangular display portion 13 is formed so that the upper half and the lower half in FIG. 2 can be simultaneously scanned. Therefore, in the organic EL display panel 11, the time required to scan the entire display unit 13 can be reduced to half compared to the case where the display unit 13 is sequentially scanned from top to bottom.

The organic EL display panel 11 has a display section 13
A thin film 16 as a protective film (sealing film) is formed so as to cover the. The thin film 16 is made of a material that blocks permeation of water, oxygen, etc., and in this embodiment, SiN is used.
_x (silicon nitride). The thickness of the display unit 13 including the thin film 16 is about 1 μm to several μm. Connection parts 14a and 15 connected to other wirings of the electrodes 14 and 15
a is not covered with the thin film 16 and is exposed. To the connecting portions 14a and 15a, for example, an FPC (flexible printed circuit board, shown by a chain double-dashed line in FIG. 1C) 17 is connected as another wiring. It

Next, the organic EL display panel 11 having the above structure
The manufacturing method of will be described. As shown in FIGS. 1A and 2, one substrate (glass substrate) 20 to a plurality of organic ELs.
When manufacturing the display panel 11, the display unit 13 is provided on the substrate 20.
Forming a plurality of. In this embodiment, four display parts 13 are formed on the substrate 20, and two cut lines 21 are formed.
Are formed on the substrate 20 so as to partition the area in which each display unit 13 is arranged. The display unit 13 is formed by sequentially stacking the electrode 15 (anode), the organic EL layer, and the electrode 14 (cathode) on the substrate 20.

After forming the display portion 13, a polyimide tape 23 as an adhesive tape which is a mask member is formed on the substrate 20.
Paste. The adhesive of the polyimide tape 23 is configured so that its adhesive strength is reduced when it is irradiated with ultraviolet rays. The polyimide tape 23 is formed in a size corresponding to the substrate 20, and a square hole 24 is formed in a position corresponding to each display unit 13. A total of four holes 24 are formed. With the polyimide tape 23 attached, only the holes 24 of the substrate 20 are exposed, and the display unit 1
3 is exposed through the hole 24. Polyimide tape 23
Thus, the connection portions 14a and 15a of the electrodes 14 and 15 are covered. The cut line 21 is covered with the polyimide tape 23. The thickness of the polyimide tape 23 is several tens of μm
And is much thicker than the thickness of the display unit 13.
In the polyimide tape 23, the side surface 25 surrounding the hole 24 is a boundary with the portion to be sealed, and the polyimide tape 23
Is formed substantially parallel to the thickness direction of the.

Next, the substrate 20 to which the polyimide tape 23 is attached is placed in the vapor deposition apparatus, and as shown in FIG. 1B, the thin film 16 is formed by plasma CVD. The mask member needs to have heat resistance higher than the temperature at the time of forming the thin film, and the temperature at the time of forming the thin film is set to 100 ° C. or lower due to the characteristics of the organic EL, which is weak against heat. Since the polyimide tape 23 has heat resistance sufficiently higher than 100 ° C., there is no problem. When the thin film is formed, the thin film 26 is also formed on the polyimide tape 23, but since the thickness of the polyimide tape 23 is significantly thicker than the display portion 13, the thin film 26 on the polyimide tape 23 and the display portion 13 are covered. It is formed in a state of being separated from the thin film 16.

After the thin film 16 is formed, it is irradiated with ultraviolet rays to reduce the adhesive force of the adhesive on the polyimide tape 23.
Then, the polyimide tape 23 is stripped off, and the electrodes 14,
The connection parts 14a and 15a of 15 and the cut line 21 are exposed. Then, the substrate 20 is cut along the cut line 21, and the manufacturing of the organic EL display panel 11 is completed as shown in FIG.

According to this embodiment, the following effects are obtained. (1) The thin film 16 is formed in a state where the polyimide tape 23 that masks the connection portions 14a and 15a of the electrodes 14 and 15 is arranged on the substrate 20, and then the polyimide tape 23 is removed. Unlike the case where a metal mask is used, the entire thickness can be set to the same thickness as when the polyimide tape 23 is not provided, so that it is easy to handle and the substrate 20 can be put in the vapor deposition apparatus for the thin film 16 without any problem. .
In addition, a thin film is formed on the entire substrate and the connecting portions 14a, 15 of the electrodes 14, 15 are formed by a patterning or ashing process.
Unlike the case where the thin film in the portion corresponding to a is removed, patterning and ashing steps are unnecessary and the electrodes 14, 1
Since the connecting portions 14a and 15a of No. 5 can be exposed, the number of steps can be reduced.

(2) The thin film 16 is formed with the cut line 21 covered with the polyimide tape 23, and the polyimide tape 23 is peeled off to cut the substrate 20 without the thin film 26 on the cut line 21. For example, if the substrate 20 is cut at the portion where the thin film is formed, the thin film may crack. Then, when the portion covering the thin film display portion 13 and the portion covering the cut line 21 are continuous, the crack entered in the portion covering the thin film cut line 21 propagates to the portion covering the display portion 13. It may crack. However, by sticking and removing the polyimide tape 23, the substrate 20 can be cut without the thin film 26 on the cut line 21, so that the thin film 16 can be prevented from cracking or peeling.

(3) Adhesive tape (polyimide tape 2
Masked in 3). Since the pressure-sensitive adhesive tape is easy to handle, it is easier to handle as compared with, for example, the case of applying a resin and masking, and the number of working steps can be reduced.

(4) The adhesive of the polyimide tape 23 is structured so that it can be treated to reduce its adhesive strength. For example, if the adhesive strength is too strong, the polyimide tape 23
There is a possibility that the electrodes 14 and 15 may be peeled off from the substrate 20 when removing the. On the other hand, if the adhesive strength is too weak, the polyimide tape 23 may be displaced or partly peeled off during the work and the electrode 1
There is a possibility that the connection portions 14a and 15a of the wires 4 and 15 cannot be sufficiently masked. In addition, the adhesive is used for the substrate and electrodes 14, 15
It is difficult to adjust the adhesive force because there is a risk of remaining on the connecting portions 14a and 15a. However, since the pressure-sensitive adhesive is configured to reduce the pressure-sensitive adhesive force, it is not necessary to adjust the difficult pressure-sensitive adhesive force, and the polyimide tape 23 should be adhered to the substrate 20 with a sufficient strength. You can

(5) The adhesive of the polyimide tape 23 can be easily weakened by irradiating it with ultraviolet rays so that the adhesive can be lowered. Further, it is easy to perform tape application and tape removal by automation.

The embodiment is not limited to the above embodiment, but may be modified as follows. The side surface of the polyimide tape 23 is not limited to be formed substantially parallel to the thickness direction of the polyimide tape 23 at the boundary with the portion to be sealed like the side surface 25 surrounding the hole 24. For example, as shown in FIG. 3, polyimide tape 23
The side surface of the polyimide tape 2 at the boundary with the part to be sealed.
The surface 23b opposite to the adhesive surface 23a of the adhesive surface 23a of FIG.
You may form so that it may become the slope 31 so that it may overhang. In this case, the thin film 26 on the polyimide tape 23
Then, the thin film can be easily formed so that the thin film 16 covering the display unit 13 is separated.

The polyimide tape is not limited to be formed in the same size as the substrate 20 as shown in FIG.
For example, as shown in FIG. 4A, a narrow polyimide tape 33 may be attached along the sides of each display portion 13 to cover only the connection portions 14a and 15a of the electrodes 14 and 15. Also, attach the polyimide tape 33 to the cut line 21.
You may stick two in a cross shape so that it may cover. The portions where the polyimide tapes 33 intersect or are close to each other are overlapped and attached. In this case, the polyimide tape 33 can be attached only to a necessary portion, and the polyimide tape 33 can be saved. Although the thin film is formed in a non-related portion other than the portion covering the display unit 13, it may be left as it is.

Display unit 1 formed on one substrate 20
The number of 3 is not limited to 4, and the size of the display unit 13 and the substrate 2
You may change suitably according to the magnitude | size of 0. For example, in FIG.
As shown in (b), when the display unit 34 is large, one display unit 34 may be formed on one substrate 20.
Even in this case, in most cases, since it is necessary to cut the substrate 20 by the cut line 35 at the edge thereof to adjust the size of the substrate, the rectangular frame-shaped polyimide tape 36 having the holes 24 is used for the electrode 14. , 15 connection parts 14a, 15a
And, it is attached so as to cover the cut line 35. Also,
If the substrate 20 is formed in an appropriate size in advance so that it is not necessary to cut it later, the cut line 35 is eliminated and it is not necessary to cover it. Therefore, the connection portions 14a of the electrodes 14 and 15 are
The polyimide tape 33 may be attached so as to cover only 15a. In addition, the square-shaped polyimide tape 36
May be formed in a corresponding size, and may be attached to a substrate formed in an appropriate size in advance so as to avoid cutting.

The cut line 21 is not limited to being formed on the substrate 20, and the cut line 21 may not be formed. In this case, a polyimide tape is attached to the substrate 20 so as to cover the portion of the substrate 20 to be cut, a thin film is formed after that, and the polyimide tape is removed. Board 20
Disconnect. Therefore, even if the cut line 21 is not formed on the substrate 20, the thin film 16 can be prevented from cracking or peeling.

The cut line 21 does not need to be covered with the polyimide tape 23, but if it is covered, the thin film 16 can be prevented from cracking when the substrate 20 is cut. Therefore, the cut line 21 is covered with the polyimide tape 23, and then the thin film 16 is formed. Are preferably formed.

The adhesive of the polyimide tape 23 does not have to be structured so as to reduce its adhesive strength. In this case, it is necessary to adjust the adhesive strength. But,
Since it is not necessary to adjust the adhesive strength, which is difficult if the adhesive is configured to be subjected to the processing for reducing the adhesive strength, it is preferable that the adhesive is configured to be subjected to the processing for reducing the adhesive strength.

The adhesive of the polyimide tape 23 is not limited to the one whose adhesive force is lowered by the irradiation of ultraviolet rays. For example, the pressure-sensitive adhesive may be configured so that the pressure-sensitive adhesive force decreases by cooling from room temperature.

The adhesive tape as the mask member is not limited to the polyimide tape, and any tape having heat resistance higher than the temperature at the time of forming the thin film may be used, for example, an aluminum tape.

The temperature at the time of forming the thin film is not limited to 100 ° C., and may be set to a higher temperature due to, for example, progress in heat resistance of the organic EL material, and the mask member has heat resistance higher than that temperature. Anything will do.

The mask member does not have to be an adhesive tape, and for example, a resin may be applied to form the mask member. The thin film 16 is not limited to being formed of silicon nitride, and may be formed of a material that blocks permeation of water, oxygen, etc., and may be formed of, for example, silicon oxide, diamond-like carbon, or the like.

The organic EL display panel 11 is not limited to the two-division scanning type, and may be a type that sequentially scans the display unit 13 from the top to the bottom. In this case, for example, the electrode 15 is formed so as to extend outward from either the upper side or the lower side of the display unit 13.

The number of electrodes 14 and 15 may be small. For example, when the organic EL element is used as a backlight, each of the electrodes 14 and 15 may be one. The substrate 20 is not limited to being cut after the polyimide tape 23 is peeled off. The substrate 20 may be cut with the polyimide tape 23 still attached, and the polyimide tape 23 may be peeled off after cutting. Since the thickness of the polyimide tape 23 is significantly thicker than the display portion 13, the thin film 16 covering the display portion 13 and the polyimide tape 2
3 is formed separately from the thin film 26 on the display 3, so that even if the thin film 26 is cracked during cutting, the display unit 13
The thin film 16 that covers is not cracked. The polyimide tape 23 acts like a cushion during cutting, so that the thin film 26 itself is unlikely to crack.

The organic EL display panel 11 may be a color display panel or a monochrome display panel. The anode and cathode may be formed on the glass substrate 12 in the reverse order.

Not limited to the passive matrix drive type organic EL display panel, it may be applied to an active matrix drive type organic EL display panel. The display unit 13 is not limited to the rectangular shape.

The invention (technical idea) that can be understood from the above-described embodiments will be added below. (1) In the invention according to claim 3, the side surface of the pressure-sensitive adhesive tape is formed obliquely so that the side opposite to the bonding surface projects from the bonding surface side at the boundary with the portion to be sealed. There is.

[0043]

As described in detail above, the first to fifth aspects of the invention are described.
According to the invention described in (1), the number of steps can be reduced and the sealing film can be formed so as to expose the connection portion of the electrode.

[Brief description of drawings]

1A is a partial schematic cross-sectional view taken along the line IA-IA of FIG. 2, and FIG. 1B is a partial schematic cross-sectional view of a state in which a thin film is formed,
(C) is a partial schematic cross section of an organic EL display panel.

FIG. 2 is a schematic plan view showing a state in which a polyimide tape is attached.

FIG. 3 is a partial schematic plan view showing a state where a polyimide tape of another example is attached.

FIG. 4A is a schematic plan view showing a state where a polyimide tape of another example is attached, and FIG. 4B is a schematic plan view showing another example.

FIG. 5 is a schematic partial cross-sectional view of a conventional organic EL display panel.

[Explanation of symbols]

11 ... Organic EL display panel, 12, 20 ... Glass substrate as substrate, 13, 34 ... Display unit, 14, 15 ... Electrode,
14a, 15a ... Connection part, 16 ... Thin film as sealing film,
21, 35 ... Cut line, 23, 33, 36 ... Polyimide tape as an adhesive tape which is a mask member.

Claims (5)

[Claims] 1. A sealing film forming step of forming a sealing film for sealing the display unit of an organic EL display panel, which includes a display unit including an organic EL element and an electrode extending from the display unit on a substrate. A method for manufacturing an organic EL display panel comprising:
An organic EL display in which the sealing film is formed in a state in which a mask member that masks at least a connection portion of the electrode with another wiring in the sealing film formation step is arranged on the substrate, and then the mask member is removed. Panel manufacturing method. 2. A cut line for cutting out an organic EL display panel is formed on the substrate, and the sealing film is formed in a state where the cut line of the substrate is also masked by the mask member. 1. The method for manufacturing the organic EL display panel according to 1. 3. The method for manufacturing an organic EL display panel according to claim 1, wherein the mask member is an adhesive tape. 4. After the treatment for decreasing the adhesive strength of the adhesive,
The method for manufacturing an organic EL display panel according to claim 1, wherein the mask member is removed. 5. The method for manufacturing an organic EL display panel according to claim 4, wherein the treatment for reducing the adhesive strength of the adhesive is irradiation of ultraviolet rays.