JP2004288554A - Organic el display and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL display wherein flatness of a bonding surface of a sealing can can be enhanced, accuracy of the applied quantity of an adhesive is relaxed, and accuracy of positioning the sealing can and an organic EL substrate can be enhanced, and to provide its manufacturing method. <P>SOLUTION: In this organic EL display formed by bonding the sealing can 2 to the organic EL substrate 1, a rib 23 having a S-shaped cross-section or a L-shaped cross-section is provided on the entire periphery of the sealing can or at its four corners. The rib is formed by stamping out the collar part of the sealing can having a recessed part 21 formed by drawing a plate material, an bonding surface 22, and the collar part 24. The rib is used for positioning of the seal can by a positioning fixture 4, and is also used for a storage part g for a surplus adhesive 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an organic EL display device using can sealing and a method for manufacturing the same.
[0002]
[Prior art]
It is known that the organic EL display device in the presence of moisture and oxygen causes a decrease in display quality and a decrease in electrical characteristics due to an increase in the size of black spots observed on a light emitting surface. Therefore, the degree of the decrease has been reduced by hermetically sealing the organic EL display device.
[0003]
Therefore, conventionally, as a sealing structure of an organic EL display device, a structure in which a glass or metal sealing can is bonded to a substrate on which an organic EL element is formed to maintain airtightness in the sealing can is generally used. However, in view of the manufacturing cost, a structure using a sealing can formed by press-molding stainless steel (SUS or the like) is often used.
[0004]
[Patent Document 1]
JP-A-2002-197173 (Section 1, FIG. 1)
[0005]
FIG. 7 shows a plan view and a cross-sectional view of a conventional press-sealed sealing can 2, and FIG. 8 shows a molding step of the sealing can 2. As shown in FIG. FIG. 8A shows a material 2A cut out from a roll material or the like into a predetermined size, which is drawn by a press as shown in FIG. 8B and formed into a predetermined shape. This pressing step may be divided into several steps depending on the complexity of the shape, the drawing depth, and the like. Next, as shown in FIG. 8C, the flange portion 2a on the outer periphery is punched out with a press. In this case, in this product, if burrs appear on the bonding surface side, a short circuit at the terminal take-out portion becomes a problem. Therefore, the product is punched upward or downward as shown by an arrow a in FIG. Such a sealing can 2 is completed.
[0006]
However, the sealing can 2 thus formed has the following problems.
[0007]
(1) In general, a sealing structure of an organic EL display device using a sealing can 2 is such that a layer of an adhesive 3 for bonding the organic EL substrate 1 and the sealing can 2 in order to suppress moisture entering from the outside is used. Desirably thin. Therefore, the flatness of the bonding surface of the sealing can 2 becomes important. However, when the aspect ratio of the sealing can 2 is large as shown in FIG. 7, the sealing can 2 has a large warp in the longitudinal direction as shown in FIG. 8D. If the sealing can 2 having such a shape is adhered as it is, not only is the thickness of the adhesive layer uneven, but in the worst case, the seal of the adhesive layer may be broken. Further, if the sealing can 2 is adhered in such a manner that pressure is applied to the sealing can 2, the sealing may be peeled off later by a reaction force.
[0008]
(2) Also, as shown in FIGS. 8 (b) and 8 (c), when the flange 2a, which is the outer periphery of the bonding surface, is punched out by a press in the final step, it is usual to prevent burrs from appearing on the bonding surface. As shown in FIG. 8C, punching is performed in the direction indicated by arrow a in the figure. However, as shown in FIG. 7, the corners 2b where the two sides of the sealing can 2 meet are concentrated in turning, so that the corners 2b are oriented in the punching direction as shown in FIG. Easy to deform. When the sealing can 2 having the deformed corners 22 is bonded to the organic EL substrate 1 as shown in FIG. 9, the bonding is performed at the corners 2b which are portions having large distortion as shown in the detailed view of the portion D in FIG. In the worst case, the agent 3 is thin and the seal is broken, and moisture in the air enters the organic EL display device, causing a dark spot.
[0009]
(3) When the sealing can 2 having the outer shape shown in FIG. 7 and the organic EL substrate 1 are bonded together by end-to-end bonding, the height of the end surface that can be used for positioning the sealing can 2 is as shown in FIG. Is the size (x) obtained by adding the thickness v of the adhesive 3 to the plate thickness t of the sealing can 2. Normally, the thickness of the sealing can 2 is 0.3 to 0.4 mm, and considering the tolerance of the protruding parts of the adhesive 3, the positioning step (L) provided on the positioning jig 4 is as shown in FIG. The thickness must be less than t. However, the step (L) having a thickness equal to or less than the plate thickness is too low, so that even if the positioning end face 2c of the sealing can 2 rides on the step (L), it is difficult for an operator to confirm. Then, problems such as breakage of the organic EL substrate 1 occur.
[0010]
As a countermeasure for this, as shown in FIG. 13, a method of laminating based on the slope 2 d of the first drawn portion of the sealing can 2 can be considered, but this method uses the positioning end face 4 a of the positioning jig 4 and the bonding end. It is necessary to match the shape of the slope 2 d of the sealing can 2. However, it is difficult to match these exactly, and it is necessary to increase the play in anticipation of tolerance. Therefore, there is a problem that positioning accuracy is reduced.
[0011]
(4) Further, when the sealing can 2 having the outer shape as shown in FIG. 7 and the organic EL substrate 1 are bonded as shown in FIG. 9, the amount of the adhesive 3 applied to ensure the bonding width is ensured. 11, the adhesive 3 protrudes from the end surface 23 of the sealing can 2 and hinders the connection of the wiring, or the adhesive 3 adheres to the positioning jig 4 of the sealing can 2. Doing so lowers work efficiency. On the other hand, if the amount of the adhesive 3 is too small and the amount of the adhesive 3 is too small, the width of the adhesive becomes narrower, and the seal can be broken at the portion where the warpage of the sealing can 2 is large. As described above, there is a problem that it is very difficult to control the amount of the adhesive 3 applied.
[0012]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned problems (1) to (4), and has an object of (a) suppressing warpage of a corner of a sealing can, and (b) a corner of an adhesive portion. (C) ensuring the height of the step required for positioning, and (d) having a sealing can capable of reducing the accuracy of the adhesive application amount. An object of the present invention is to provide an organic EL display device and a method for manufacturing the same.
[0013]
[Means for Solving the Problems]
The present invention provides an organic EL display device and a method of manufacturing the same according to the invention as means for solving the above problems.
[0014]
In the organic EL display device according to the first aspect, a rib having an S-shaped cross section or an L-shaped cross section is provided on the entire circumference or at four corners of the outer peripheral portion of the sealing can adhered to the organic EL substrate with an adhesive. Things. By providing the rib on the outer peripheral portion of the sealing can in this way, warpage during press molding of the sealing can can be suppressed, and the flatness of the bonding surface can be improved. Also, when punching the outer shape of the sealing can in the final step of pressing, the surface that is one step lower than the adhesive surface will be punched, so the distortion generated at the four corners can be eliminated and the flatness of the adhesive surface is improved As a result, it is possible to prevent the occurrence of seal breakage at the corner portion. Further, since the S-shaped rib can secure the height of the step required for positioning, the positioning accuracy of the sealing can can be improved. The substrate 1 itself is generally formed of glass.
[0015]
In the organic EL display device according to the present invention, the gap formed between the rib having the S-shaped cross section provided on the outer periphery of the bonding surface of the sealing can and the organic EL substrate contains an excess adhesive. It is designed to be used as an agent accommodating portion, whereby the extruded portion of the adhesive can be absorbed, and the control of the amount of the applied adhesive can be eased.
[0016]
A method of manufacturing an organic EL display device according to a third aspect of the present invention is obtained by converting the invention of the first aspect into an invention of a manufacturing method, and its operation and effect are substantially the same as those of the first aspect. is there.
[0017]
In the manufacturing method according to the fourth aspect, the sealing can is positioned by bringing the end face of the rib having the S-shaped cross section into contact with the sealing can positioning reference end face of the positioning jig. Thereby, the sealing can can be accurately positioned and adhered to the organic EL substrate.
[0018]
According to a fifth aspect of the present invention, when the sealing can is bonded to the organic EL substrate, an excess adhesive is accommodated in a gap formed between the rib having the S-shaped cross section and the organic EL substrate. Accordingly, it is not necessary to strictly control the amount of the adhesive to be applied, and the control of the amount of the adhesive can be eased.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an organic EL display according to an embodiment of the present invention and a method for manufacturing the same will be described with reference to the drawings. FIG. 1 shows a plan view and a cross-sectional view taken along line II of a sealing can used in the organic EL display device according to the embodiment of the present invention. FIG. 2 is an enlarged detailed view of a portion A in FIG. Yes, two embodiments (a) and (b) are shown. The sealing can 2 of the present invention generally has a generally rectangular dish shape, covers an organic EL element (not shown) formed on the organic EL substrate 1, and contains a moisture absorbent therein. And a bonding surface 22 formed on the outer periphery of the concave portion 21, and a rib 23 formed on the outer periphery of the bonding surface 22.
[0020]
The cross-sectional shape of the rib 23 may be formed in an S shape as in the first embodiment shown in FIG. 2A, or may be formed as in the second embodiment shown in FIG. It may be formed in an L-shape. The ribs 23 have an effect of suppressing warpage during press molding of the sealing can 2, which will be described later, particularly warpage in the longitudinal direction, and can improve the flatness of the bonding surface 22. Further, since the ribs 23 are formed by punching out a flange portion 24 having a lower step outside the bonding surface 22 when the outer shape of the sealing can 2 is punched in a final step of a press described later, conventionally, Since the distortion generated at the four corners of the corner 25 of the bonding surface (22) is also generated at the tip of the rib 23 which is a part of the flange portion 24 that is lowered by one step, the distortion at the bonding surface 22 is eliminated, The flatness of the bonding surface 22 is improved, and it is possible to prevent the adhesive from being cut off at the corner (corner) 25.
[0021]
Hereinafter, a method for manufacturing the organic EL display device of the present invention will be described.
[0022]
FIG. 3 is a view showing a molding step of the sealing can of the present invention, which is basically the same as a conventional general step. FIG. 3A shows a flat plate material 2A cut out from a roll material or the like into a predetermined size. This plate material 2A is drawn by a press as shown in the cross-sectional shape of FIG. That is, the sealing can 2 in the course of manufacturing includes a concave portion 21, an adhesive surface 22 on the outer periphery of the concave portion 21, and a brim portion 24 formed on the outer periphery of the adhesive surface 22 and having a surface one step lower than the adhesive surface 22. have. This drawing step may be divided into several steps depending on the complexity of the shape of the sealing can 2 and the drawing depth. Next, as shown in FIG. 3 (c), the rib 23 is punched out on the outer periphery of the bonding surface 22 by pressing so as to leave the rib 23 on the outer circumference of the bonding surface 22, and the sealing of the present invention as shown in FIG. The can 2 is completed. The punching direction of the brim portion 24 is punched out in such a direction as to drop down from the upper side to the lower side in the figure as shown by an arrow a in FIG. This is to minimize the adverse effect of burrs on the bonding surface 22 side.
[0023]
FIG. 4 is a partial cross-sectional view for explaining a positioning structure at the time of bonding the organic EL substrate 1 and the sealing can 2 constituting the organic EL display device of the present invention. The organic EL element is omitted from the organic EL substrate 1. Reference numeral 3 denotes an adhesive for bonding the organic EL substrate 1 and the sealing can 2, and reference numeral 4 denotes a positioning jig for positioning the sealing can 2 with respect to the organic EL substrate 1.
[0024]
This positioning method is performed as follows. In other words, the sealing can positioning reference end surface 41 of the positioning jig 4 is brought into contact with the end surface 26 (the end surface for positioning the sealing can) of the S-shaped cross-section rib 23 of the sealing can 2, whereby this sealing is performed. The sealing can 2 is arranged in the positioning jig 4 with reference to the can positioning reference end face 41. At this time, the positioning height dimension (w) that can be used for positioning the sealing can 2 can be used up to the plate thickness (t) of the sealing can 2 + the drawing height (u) + the adhesive thickness (v). In addition, the positioning of the sealing can 2 can be performed without running over the positioning reference end surface unlike the related art.
[0025]
Next, the adhesive 3 is applied to the adhesive surface 22 of the sealing can 2. Then, the whole of the positioning jig 4 is transported into a side box (not shown) and evacuated, and then transported into a glove box (not shown). Next, as shown in FIG. 4, the end surface of the organic EL substrate 1 is brought into contact with the organic EL substrate positioning reference end surface 42 of the positioning jig 4 so that the organic EL substrate 1 is positioned with respect to the reference end surface 42. The sealing can 2 is adhered to the organic EL substrate 1 by applying pressure in this state.
[0026]
In this manner, the sealing can 2 and the organic EL substrate 1 can be assembled with the reference end surfaces 41 and 42 of the positioning jig 4, so that the positioning jig 4 can be accurately sealed without providing an unnecessary gap. The can 2 can be bonded to the organic EL substrate 1.
[0027]
Next, control relaxation of the amount of the adhesive 3 applied to the bonding surface 22 of the sealing can 2 will be described. FIG. 5 is a diagram showing a comparison between (a) the sealing can bonding portion of the present invention and (b) the sealing can bonding portion of the prior art. In FIG. 5, reference numeral M indicates a display range of the organic EL display device, and reference numeral N indicates a frame size thereof.
[0028]
Generally, the adhesive 3 applied to the bonding surface 22 of the sealing can 2 does not protrude more than necessary from the end surface 26 of the sealing can 2 when the organic EL substrate 1 is overlapped and bonded. It is necessary to control the application amount of the adhesive 3 so that the width S is not too narrow. In FIG. 5B, the adhesive 3 protrudes from the end surface 26 of the sealing can 2 by a range T because the amount of application is too large. If the application amount is small, the bonding width S will be small. Thus, it has been difficult to control the bonding width S by adjusting the amount of the adhesive 3 applied.
[0029]
Therefore, in the present invention, as shown in FIG. 5A, the gap formed between the rib 23 having an S-shaped cross section provided on the outer periphery of the bonding surface 22 of the sealing can 2 and the organic EL substrate 1 is bonded. The excess adhesive T applied to the adhesive surface 22 of the sealing can 2 is stored in the adhesive storage g to be used as the adhesive storage g. And the control of the application amount of the adhesive 3 can be relaxed.
[0030]
Further, as shown in FIG. 5A, the cross-sectional area of the adhesive accommodating portion g can be made larger than the cross-sectional area of the protruding amount shown in FIG. 5B, so that the adhesive 3 can be formed without increasing the frame size N. Can be handled.
[0031]
FIG. 6 shows another embodiment of the sealing can 2 of the present invention. In the sealing can 2 of the previous embodiment, the ribs 23 are formed over the entire outer periphery of the sealing can 2, but in the present embodiment, the cross section is formed only at the four corners, which are the corners 25 of the sealing can 2. An S-shaped rib 23 is formed. Other configurations are the same as the previous configuration. FIG. 6A shows a plan view of the entire sealing can 2, and FIG. 6B shows an enlarged detailed view of a portion B in FIG. 6A. The reason why the ribs 23 are provided only at the corners 25 of the sealing can 2 is that wiring such as a TCP (semiconductor package) connected to the organic EL substrate 1 is indicated by a two-dot chain line in FIG. This is to avoid the part 4. However, in the present embodiment, since the ribs 23 are not provided on the entire outer periphery of the sealing can 2, it is impossible to expect a reduction in the amount of the adhesive 3 applied.
[0032]
As described above, in the present invention, by providing the sealing can with the ribs, the warpage of the bonding surface of the sealing can can be suppressed, and the distortion generated at the four corners of the bonding surface can be eliminated. Not only is it possible to prevent spots and breaks in the seal, but also to achieve remarkable effects such as an improvement in the positioning accuracy between the sealing can and the organic EL substrate and a reduction in the accuracy of the amount of adhesive applied. Things.
[Brief description of the drawings]
FIG. 1 is a plan view and a cross-sectional view taken along line II of a sealing can of an organic EL display device according to an embodiment of the present invention.
FIG. 2 is an enlarged detailed view of a portion A of the sealing can of FIG. 1, wherein (a) shows the rib shape of the first embodiment and (b) shows the rib shape of the second embodiment.
FIG. 3 is a view showing molding steps (a) to (c) of a sealing can of the organic EL display device of the present invention.
FIG. 4 is a diagram illustrating a method for positioning the sealing can and the organic EL substrate of the present invention using a positioning jig.
FIGS. 5A and 5B are diagrams illustrating (a) the present invention and (b) a comparison between the present invention and the related art regarding control relaxation of an adhesive application amount in the present invention.
FIG. 6 is a plan view of a sealed can of another embodiment of the present invention and an enlarged detailed view of a portion B.
FIG. 7 is a plan view, a sectional view taken along line VII-VII, and an enlarged detailed view of a portion c of a conventional sealing can.
FIG. 8 is a diagram illustrating molding steps (a) to (d) of a conventional sealing can.
FIG. 9 is a plan view and a side view of a conventional organic EL display device.
10 is an enlarged detailed view of a portion D in FIG. 9 and a sectional view taken along line XX.
FIG. 11 is a diagram for explaining protrusion of an adhesive in a conventional technique.
FIG. 12 is a diagram illustrating a method for positioning a sealing can and an organic EL substrate using a positioning jig according to a conventional technique.
FIG. 13 is a diagram illustrating another positioning method according to the related art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Organic EL substrate 2 ... Sealing can 21 ... Concave part 22 ... Adhesion surface 23 ... Rib 24 ... Flange 25 ... Corner 26 ... Rib end surface of S-shaped cross section (end surface of sealing can)
3 adhesive 4 positioning jig 41 sealing can positioning reference end face 42 organic EL substrate positioning reference end face

Claims (5)

In an organic EL display device in which a sealing can is covered over an organic EL element formed on an organic EL substrate, and the sealing can and the organic EL substrate are bonded with an adhesive,
An organic EL display device, wherein a rib having an S-shaped cross section or an L-shaped cross section is provided on the entire circumference or at four corners of the outer periphery of the sealing can. Utilizing a gap formed between the organic EL substrate and the rib having the S-shaped cross section provided on the outer periphery of the bonding surface of the sealing can as an adhesive storage portion for storing an excess amount of adhesive. The organic EL display device according to claim 1, wherein: In a method for manufacturing an organic EL display device, a method of manufacturing an organic EL element by forming a sealing can over an organic EL element formed on an organic EL substrate and bonding the sealing can and the organic EL substrate together with an adhesive.
Forming a sealing can having a concave portion for containing the moisture absorbent, an adhesive surface formed on the outer periphery of the concave portion, and a brim portion formed on the outer periphery of the adhesive surface by drawing a flat plate material by pressing. Stage to
Punching out the collar portion with a press to form a rib having an S-shaped cross section or an L-shaped cross section on the outer periphery of the bonding surface;
A method for manufacturing an organic EL display device, comprising: The method according to claim 3, further comprising the step of positioning the sealing can by bringing an end surface of the rib having the S-shaped cross section into contact with a sealing can positioning reference end surface of a positioning jig. The manufacturing method of the organic EL display device according to the above. In the step of adhering the sealing can and the organic EL substrate, an excess amount of adhesive is accommodated in a gap formed between the rib having the S-shaped cross section and the organic EL substrate. Item 5. The method for manufacturing an organic EL display device according to item 3 or 4.

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