JP2007242313A - Manufacturing method of display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a display wherein dark spots are prevented from being generated even if the display is structured so that a sealing substrate is pasted to an element substrate through a thin protective film, and an organic EL display suitable for a top emission type can be thereby obtained at a low cost and a good yield. <P>SOLUTION: An organic electroluminescent element 3 is formed on the element substrate 1. The protective layer 5 having sufficient sealing ability is deposited on the element substrate 1 with the organic electroluminescent element 3 covered with it. The protective layer 5 is then etched and thinned to such an extent that it has sufficient light transmittance. A sealing substrate 9 is pasted to the protective layer 5 side through an adhesive resin 7 in an inactive atmosphere controlled continuously with the etching to obtain this display 11. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a display device including an organic electroluminescent element, and more particularly to a method for manufacturing a display device suitable for a so-called top emission type in which emitted light is extracted from a side opposite to a substrate on which an element is formed.

  In recent years, next-generation displays have been actively developed in the field of display devices, and space saving, high brightness, low power consumption, and the like are demanded. As such a display device, a so-called organic EL display using an organic electroluminescent element (so-called organic EL element) has attracted attention. Since this organic EL display is a self-luminous type, it has a wide viewing angle, and since it does not require a backlight, it can be expected to save power, has high responsiveness, and can reduce the thickness of the device itself. Yes.

  On the other hand, in the above-described organic EL display, the organic EL element is extremely weak against moisture, and deteriorates due to moisture in the atmosphere, so that an area that does not emit light (dark spot) is generated or brightness is likely to decrease. For this reason, a sealing technique for suppressing the intrusion of moisture into the display region provided with the organic EL element is indispensable.

  Therefore, for example, the organic EL device formed on the substrate is covered with a protective film, and further, the sealing substrate is bonded through a resin material serving as an adhesive, thereby sealing the organic electroluminescent device in the resin material. A completely solid sealing structure has been proposed. Such a structure is highly effective in preventing the occurrence of the above-mentioned problems because there is no gap left between the substrates on which the organic electroluminescent elements are sandwiched.

  In particular, in such a sealing structure, a configuration is proposed in which the protective film is a laminated structure of an organic protective film and an inorganic protective film, and these protective films are continuously formed without breaking the vacuum. (See Patent Document 1 below).

JP 2000-68050 A (refer to paragraphs 0018 and 0019 in particular)

  By the way, in the organic EL display described above, it is possible to enhance the function of the device by adopting an active matrix type in which a driving thin film transistor (TFT) is connected to an organic EL element. In the manufacture of this active matrix type display device, an organic EL element is formed on a substrate on which a thin film transistor has been previously formed (so-called TFT substrate) in a state of being connected to the thin film transistor. A so-called top emission type in which emitted light is extracted from the side is effective in securing the aperture ratio of the pixel. Further, in the case of the top emission type, patterning when providing a color filter on the emission light extraction side of the organic EL element is easy.

  In the top emission type organic EL display as described above, a protective film for preventing moisture from entering the organic EL element is disposed on the light emission side of the organic EL element. Therefore, the light-transmitting property is also required for this protective film, and it is necessary to reduce the film thickness of the protective film to some extent in order to ensure the light-transmitting property. However, it is difficult to sufficiently protect the organic EL element simply by reducing the thickness of the protective film as it is, and the effect of preventing the occurrence of dark spots is reduced.

  In order to prevent this, after forming the organic EL element on the substrate, it is covered with a protective film, and then the process of bonding the sealing substrate through the resin material is performed without exposing to the atmosphere. A method of continuously performing in an inert atmosphere including an atmosphere is conceivable. However, in such a method, the substrate must be transported under the consistent atmosphere control between the above-described processes, the manufacturing equipment is enlarged, the initial cost is increased, and the running cost is increased due to the atmosphere control. It is.

  Therefore, the present invention can sufficiently prevent the generation of dark spots even in a configuration in which a sealing substrate is bonded through a thin protective film without increasing the size of the manufacturing equipment, and this makes it an organic material suitable for the top emission type. It is an object to provide a manufacturing method capable of obtaining an EL display at a low cost and a good yield.

  In the display device manufacturing method of the present invention for achieving such an object, first, a first step of forming an organic electroluminescent element on an element substrate is performed. Next, the 2nd process which forms a protective film on an element substrate in the state which covers an organic electroluminescent element is performed. Then, the 3rd process which etches a protective film and thins it is performed. Next, in an atmosphere managed continuously with the third step, a fourth step of bonding the sealing substrate to the protective film side via an adhesive resin is performed.

  In such a manufacturing method, by forming the protective film with a sufficient thickness in the second step, the protective film is used regardless of the surrounding atmosphere until the protective film is etched in the next third step. An organic electroluminescent element is reliably sealed. Then, in the etching of the next third step, even if the protective film is thinned to such an extent that the light emitted from the organic electroluminescent element can be sufficiently extracted from the protective film side, the etching is continuously performed. Then, the sealing substrate is bonded while the sealing state of the organic electroluminescent element is secured by performing the bonding of the sealing substrate in the next fourth step in the controlled atmosphere.

  As described above, the process before the second process including the formation of the organic electroluminescent element and the process after the third process including the bonding of the sealing substrate are not performed in a continuous management atmosphere, and the thin protective film is interposed. Even in the configuration in which the sealing substrate is bonded, the display device is manufactured in a state where the organic electroluminescent element is securely sealed.

  As described above, according to the present invention, a thin protective film can be formed without forming a continuous management atmosphere from the formation of the organic electroluminescent element to the pasting of the sealing substrate, and thus without increasing the size of the manufacturing equipment. Even when the sealing substrate is bonded to the display device, the display device can be manufactured in a state where the organic electroluminescent element is securely sealed. As a result, it is possible to obtain a display device suitable for the top emission type that extracts light emitted from the organic electroluminescent element through the protective film at a low cost and with a good yield.

  Hereinafter, a method for manufacturing a display device of the present invention will be described in detail with reference to the drawings. In the following embodiments, a manufacturing method will be described by taking a display device (that is, an organic EL display) in which a plurality of organic electroluminescent elements are arrayed on a substrate as an example.

<< First Embodiment >>
FIG. 1 is a process diagram showing a characteristic part of a method for manufacturing a display device according to the first embodiment, and the process shown in each figure is performed as follows.

<Fig. 1 (1)>
First, the element substrate 1 is prepared. Then, on the display region 1a set at the center of the element substrate 1, organic electroluminescent elements 3 respectively connected to a drive circuit having a thin film transistor (TFT) not shown here are arranged in a matrix. Form.

  The organic electroluminescent element 3 formed here is one in which light emitted from each organic electroluminescent element 3 is extracted from the side opposite to the element substrate 1, and has the following configuration, for example. That is, on the element substrate 1, a first electrode having a reflection function, an organic layer including a light emitting layer, and a second electrode made of a semi-transmissive material or a transparent conductive film are laminated in this order. Of these, the first electrode is provided as an anode (or cathode), and the second electrode is provided as an electrode having a polarity opposite to that of the first electrode.

  These organic electroluminescent elements 3 are, for example, arranged in a predetermined state as a set of elements that emit red light, elements that emit green light, and elements that emit blue light, or are white light emitting elements? Or a blue light emitting element. The light emission color of each organic electroluminescent element 3 is set by the constituent material of the light emitting layer.

  When a plurality of display devices are manufactured from one element substrate 1, a plurality of device regions are set on the element substrate 1, and the above-described organic electric field is provided in each display region located at the center of each device region. The light emitting elements 3 are arranged in an array.

  The organic electroluminescent element 3 as described above is formed by forming each layer and patterning it, and further by forming a pattern using a mask. In particular, from the formation of the organic layer to the formation of the upper electrode is performed in a continuously controlled vacuum atmosphere.

<Figure 1 (2)>
Next, a protective film 5 is formed on the element substrate 1 so as to cover the organic electroluminescent element 3. This protective film 5 is for preventing the permeation of oxygen and moisture from the external environment and preventing the functional degradation of the organic electroluminescent element 3. As such a protective film 5, it is necessary to use a material that is transparent or has a high light transmittance in order to ensure the extraction efficiency of the light generated in the organic electroluminescent element 3. As such a material, for example, an inorganic material such as silicon oxide (SiOx), silicon nitride (SiNx), or silicon oxynitride (SiNxOy), or an organic material such as polyparaxylene or polyimide can be used.

  The protective film 5 using such a material is not limited to a single layer structure, and may have a laminated structure. In this case, a laminated structure of inorganic material films, a structure in which an organic material film is laminated on the inorganic material film, and a structure in which an inorganic material film is laminated on the organic material film are exemplified.

  In particular, here, foreign matter and defects adhering to the surface of the organic electroluminescent element 3 are completely covered to such an extent that moisture and oxygen can be sufficiently prevented from entering the organic electroluminescent element 3. It is important to form the protective film 5 with a sufficient film thickness.

  At this time, the protective film 5 may be formed as a thick film, so that the light transmittance required for the protective film 5 may be lower. For example, in the display device manufactured here, even if the final light transmittance required for the protective film 5 is 90% or more with respect to light having a wavelength of 400 to 800 nm, The light transmittance of the protective film 5 may be less than 90%.

  Here, FIG. 2 shows the change over time of the light emitting area of the organic electroluminescent element 3 (at room temperature and normal pressure) for each film thickness of the protective film 5 made of the same material covering the organic electroluminescent element 3. The light emitting area corresponds to the number of organic electroluminescent elements emitting light with respect to the total number of organic electroluminescent elements in a state where a plurality of organic electroluminescent elements 3 are provided in a matrix. For this reason, the decrease in the light emitting area with time means that the number of organic electroluminescent elements that did not emit light due to deterioration increased.

  As shown in FIG. 2, in the case of a protective film made of the same material, the thicker the film, the lower the time-dependent decrease in the light emitting area, and the higher the ability to seal and protect the organic electroluminescent element. I understand that. Further, it can be seen that a protective film having a certain thickness can provide a higher sealing protective ability than a case where the organic electroluminescent element is held in a nitrogen atmosphere without providing a protective film.

  Therefore, in the formation of the protective film 5, the material used as the protective film 5 is subjected to the change over time (normal temperature, normal pressure) of the light emission area of the organic electroluminescent element 3 for each film thickness as shown in FIG. The film thickness is determined experimentally, and from this result, the film thickness that provides the capability required for sealing the organic electroluminescent element is set. And the protective film 5 is formed so that it may become the set film thickness.

Further, the step of forming the protective film 5 with the above film thickness is performed in an atmosphere controlled continuously with the step of forming the organic electroluminescent element 3. Here, it is important to perform the formation of the protective film 5 in a state in which the supply of moisture and oxygen to the organic layer constituting the organic electroluminescent element 3 is prevented. For this reason, for example, the formation of the organic layer of the organic electroluminescent element 3 to the formation of the upper electrode and further the formation of the protective film 5 are performed in a continuous inert atmosphere. Here, the inert atmosphere is, for example, an inert gas atmosphere such as an argon (Ar) gas atmosphere or a nitrogen (N ₂ ) gas atmosphere, and a vacuum atmosphere, and has a dew point of −80 degrees or less, oxygen (O ₂ ) The concentration is 0.5 ppm or less.

And after the film-forming process of the protective film 5 mentioned above is complete | finished, the element substrate 1 in which the protective film 5 was formed is conveyed to the etching apparatus used at the next process. In this transfer, the element substrate 1 is placed in a clean room atmosphere under a certain degree of active atmosphere, for example, a dew point of −80 degrees or more and an oxygen (O ₂ ) concentration of 0.5 ppm or more, or an air atmosphere (oxygen concentration). 15 to 25% and humidity of about 20 to 90%). Alternatively, the humidity and oxygen may be housed and transported in a transport jig in which humidity and oxygen are controlled to some extent.

<Fig. 1 (3)>
Next, the protective film 5 provided so as to cover the element substrate 1 is thinned by etching. Here, the protective film 5 is etched and thinned in a state where moisture and oxygen are prevented from being supplied to the organic layer constituting the organic electroluminescent element 3. Therefore, as this etching, so-called dry etching, which is performed by supplying an etching gas in a controlled inert atmosphere, is performed.

  At this time, in the display device manufactured here, for example, until the light transmittance of 90% or more is obtained with respect to light having a wavelength of 400 to 800 nm so that the final light transmittance required for the protective film 5 is obtained. It is important to thin the protective film 5 by etching back the entire surface.

  Etching of the protective film 5 is performed under the condition that the flatness of the surface of the protective film 5 is increased, so that when the adhesive resin is applied on the protective film 5 in the next step, bubbles, voids, Thickness unevenness can be prevented.

  Here, for example, when the protective film 5 is made of silicon oxide (SiOx) and fluorine gas is used for etching the protective film 5, fluorine is adsorbed as a residual etching gas a on the etching surface of the protective film 5. It has become. This fluorine reduces the wettability and adhesion of the adhesive resin formed on the protective film 5 in the next step to the protective film 5 and also causes a curing failure.

  Therefore, in the next step shown in FIG. 1 (4), plasma processing is performed to remove the residual etching gas a adsorbed on the etching surface of the protective film 5.

<Fig. 1 (4)>
This plasma treatment is performed by introducing nitrogen gas (N ₂ ), oxygen gas (O ₂ ), or both into the treatment atmosphere after completion of etching. As a result, the etching surface layer of the protective film 5 is oxidized to a maximum of about 100 nm to remove fluorine, thereby making it hydrophilic.

  The plasma processing as described above is continuously performed in the same processing chamber as the etching processing of the protective film 5 described with reference to FIG. 1C, or is performed in a continuously controlled atmosphere. This is very important. Thereby, the protective film 5 thinned by etching is prevented from being exposed to an active atmosphere containing moisture and oxygen such as an air atmosphere. However, in the case of using oxygen gas at the time of plasma processing, an inert atmosphere of the processing atmosphere is secured by introducing oxygen gas while maintaining a sufficiently reduced pressure in the processing chamber.

  The plasma treatment described above may be performed as necessary. For example, when there is no adsorption of the residual etching gas on the etching surface of the protective film 5, or even if the residual etching gas is adsorbed, the wettability and adhesion of the adhesive resin formed in the next step, and further the curing characteristics When it is possible to secure the above, it is not necessary to perform plasma treatment.

<Fig. 1 (5)>
Next, the sealing substrate 9 is bonded to the protective film 5 side through the adhesive resin 7. The sealing substrate 9 is made of a light transmissive glass substrate, a moisture-proof film, or the like. When only the organic electroluminescent elements 3 having the same emission color are arranged on the element substrate 1, a color filter or a color conversion corresponding to each organic electroluminescent element 3 is formed on the sealing substrate 9. It is assumed that the layer is patterned.

  And this bonding process is performed under the atmosphere managed continuously with the etching process of the protective film 5, and it is important to be performed especially in the inert atmosphere mentioned above.

  Below, the 1st example-3rd example of bonding of the element substrate 1 and the sealing substrate 9 is demonstrated.

  In the first example, first, a sealing material is applied and formed by a dispenser, an inkjet method, a printing method, or the like so as to completely surround the periphery of the display region 1a of the element substrate 1. For the sealing material, UV curable, delayed UV curable, thermo curable, UV curable epoxy resin, acrylic resin or various resins such as silicone resin are used alone or in combination. It is done. Further, the application line width of the sealing material is desirably about 30 μm to 500 μm, and the height is desirably about 10 μm to 100 μm.

  Thereafter, the filler is supplied onto the display area 1a surrounded by the sealing material. At this time, in the next step of bonding the sealing substrate 9, in order to prevent bubbles from remaining between the element substrate 1, the filler is applied in one or several points in a dotted manner, Apply and supply in a combination of linear and wavy lines. This filler had an adhesive function among various types of resins such as ultraviolet curable, delayed ultraviolet curable, thermosetting, and ultraviolet curable epoxy resin, acrylic resin or silicone resin. A resin that has a viscosity of 1 Pa · s or less and a light transmittance after curing of 80% or more and is sufficiently cured is selected and used.

  Next, the sealing material and the filler described above are used as the adhesive resin 7, and the sealing substrate 9 is bonded to the protective film 5 side of the element substrate 1 through the adhesive resin 7. At this time, bubbles are formed between the element substrate 1 and the sealing substrate 9 by performing either a pressing method under an atmospheric pressure or a method of bonding in a vacuum and pressing with a pressure difference from the atmospheric pressure. It is important not to leave behind. However, the atmospheric pressure atmosphere is maintained as an inert atmosphere.

  In addition, a color conversion layer or a color filter is applied to the organic light-emitting element 3 as necessary, just before the element substrate 1 and the sealing substrate 9 are bonded or just before bonding, and before the adhesive resin 7 is cured. Thus, the element substrate 1 and the sealing substrate 9 are aligned. Then, the ultraviolet curable resin applied to a part of the outer peripheral side of the adhesive resin 7 is irradiated with ultraviolet rays, and the substrates 1 and 9 are temporarily fixed in an aligned state.

  Thereafter, the adhesive resin 7 is cured. This curing is performed under conditions set by the material used as the adhesive resin 7. For example, in the case of using an ultraviolet curable resin, the temperature is 100 ° C. or lower after irradiating ultraviolet rays from the sealing substrate 9 side. It is cured by heating for a predetermined time on a hot plate heated to a constant temperature. The adhesive resin 7 may be cured in a vacuum or in an atmosphere released from the vacuum.

  In the second example, first, the display region 1a of the element substrate 1 is covered with at least one type of adhesive resin 7 by any one of a dispensing method, an ink jet method, a printing method, and a spin coating method. As the resin, ultraviolet curable, delayed ultraviolet curable, thermosetting, and ultraviolet heat combined curable epoxy resin, acrylic resin, silicone resin, or various composite resins thereof are used.

  Thereafter, in the same procedure as in the first example, the sealing substrate 9 is bonded to the protective film 5 side of the element substrate 1 via the adhesive resin 7, and the element substrate 1 and the sealing substrate 9 are bonded as necessary. The alignment and temporary fixing are performed, and the adhesive resin 7 is further cured.

  According to the procedure described in the second example as described above, the adhesive resin 7 on the protective film 5 can be a single type of resin, and simpler bonding than the second example can be performed. it can.

  The third example is an example in which a sheet-like resin is used as the adhesive resin 7. The sheet-like resin constituting the adhesive resin 7 is an epoxy resin, an acrylic resin, or a composite thereof, and is cured by heat, ultraviolet irradiation, or a composite thereof.

  Here, first, a sheet-like adhesive resin 7 is bonded onto the protective film 5 of the element substrate 1 using a roll laminator. Next, the separator (mounting paper) is peeled off from the sheet-like adhesive resin 7. Thereafter, before the adhesive resin 7 is cured, the sealing substrate 9 made of a sheet-like resin is bonded to the protective film 5 side of the element substrate 1 through the adhesive resin 7. At this time, it is important to prevent bubbles from remaining between the element substrate 1 and the sealing substrate 9 by performing bonding in a vacuum atmosphere. It is the same.

  Thereafter, the element substrate 1 and the sealing substrate 9 are aligned and temporarily fixed as necessary in the same procedure as in the first example, and the adhesive resin 7 is further cured.

  According to the procedure described in the third example, the thickness between the element substrate 1 and the sealing substrate 9 is almost equal to the thickness of the adhesive resin 7 on the sheet supplied to the element substrate 1 side in advance. Therefore, no pressure is required when the element substrate 1 and the sealing substrate 9 are bonded to each other.

  Then, the element substrate 1 and the sealing substrate 9 are bonded together by the procedure of any of the first to third examples described above, and the adhesive resin 7 is cured, whereby the organic electroluminescent element 3 is formed. A display device 11 arranged on the element substrate 1 is completed.

  According to the manufacturing method of the first embodiment described above, the protective film 5 is formed in a sufficient thickness in the step described with reference to FIG. The organic electroluminescent element 3 can be reliably sealed by the protective film 5 regardless of the surrounding atmosphere until it is thinned by etching. Then, in the etching step described with reference to FIG. 1C, when the protective film 5 is thinned to such an extent that the light emitted from the organic electroluminescent element 3 can be sufficiently extracted from the protective film 5 side. Even so, this etching step and the following FIGS. 1 (4) to 1 (5) are performed in a continuously controlled atmosphere, so that the sealing state of the organic electroluminescent element 5 is secured. The stop substrate 9 can be bonded. Therefore, it is possible to prevent the occurrence of dark spots due to the intrusion of moisture or oxygen into the organic electroluminescent element 3 during the manufacturing process.

  From the above, the process before FIG. 1 (2) including the formation of the organic electroluminescent element and the process subsequent to FIG. 1 (3) including the bonding of the sealing substrate are not performed in a continuous management atmosphere. Display in a state in which the organic electroluminescent element 3 is securely sealed even when the sealing substrate 9 is bonded through the sufficiently thinned protective film 5 without increasing the size of the manufacturing equipment. The device 11 is manufactured. As a result, it is possible to obtain a display device 11 suitable for a top emission type that extracts light emitted from the organic electroluminescent element 3 through the thin protective film 5 at a low cost and with a good yield.

<< Second Embodiment >>
FIG. 3 is a process diagram showing the characteristic part of the method for manufacturing the display device according to the second embodiment. The manufacturing method of the second embodiment will be described below based on the process diagram of FIG. In addition, description of the procedure which overlaps with 1st Embodiment demonstrated using FIG. 1 is abbreviate | omitted.

<Fig. 3 (1)>
First, as in the first embodiment, the element substrate 1 is prepared, and the organic electroluminescent elements 3 are arranged and formed in a matrix on the element substrate 1.

<Fig. 3 (2)>
Next, a protective film 5 is formed on the element substrate 1 so as to cover the organic electroluminescent element 3. At this time, the display area 1 a in the element substrate 1 is opened, and a mask 21 having a shape covering the peripheral area 1 b is disposed on the element substrate 1 so as to face the element substrate 1. Then, the protective film 5 is formed by vapor deposition from above the mask 21 so as to cover the display region 1a. The material of the protective film 5 formed here is the same as that of the first embodiment.

  The protective film 5 has a film thickness in the display region 1a similar to that of the first embodiment, and is sufficient to prevent moisture and oxygen from entering the organic electroluminescent element 3. It is important to form the protective film 5 with a sufficient film thickness so that foreign matters and defects attached to the surface of the organic electroluminescent element 3 are completely covered during the manufacturing process.

  The step of forming the protective film 5 with the above thickness is performed in an atmosphere controlled continuously with the step of forming the organic electroluminescent element 3, and the organic layer constituting the organic electroluminescent element 3. In contrast to the first embodiment, the process up to the formation of the protective film 5 in a state in which the supply of moisture and oxygen is prevented is performed.

And after the film-forming process of the protective film 5 mentioned above is complete | finished, the element substrate 1 in which the protective film 5 was formed is conveyed to the etching apparatus used at the next process. In this conveyance, the element substrate 1 is placed in an atmosphere having a dew point of −80 degrees or more and an oxygen (O ₂ ) concentration of 0.5 ppm or more, for example, in an atmosphere in a clean room or an air atmosphere (oxygen concentration of 15 to 25%, humidity of about (About 20-90%). Further, as in the first embodiment, the humidity and oxygen may be housed and transported in a transport jig that is controlled to some extent.

  In the film formation by vapor deposition from above the mask 21 as described above (mask vapor deposition), the vapor deposition material goes around the mask 21 and is also formed in the peripheral region 1 b that becomes a shadow of the mask 21. The film thickness of the protective film 5 in the peripheral area 1b is thinner than that of the display area 1a, and becomes thinner toward the peripheral edge away from the display area 1a.

<Fig. 3 (3)>
Next, the protective film 5 provided so as to cover the element substrate 1 is thinned by etching. Here, as in the first embodiment, the protective film 5 is thinned by dry etching, and the protective film 5 is etched back to a final thickness so that the final light transmittance required for the protective film 5 is obtained. Is important. Further, here, the protective film 5 in the peripheral region 1b is also thinned by this etching, and the element substrate 1 is continuously exposed at the outermost peripheral portion of the peripheral region 1b.

  It should be noted that the etching of the protective film 5 is performed under the condition that the flatness of the surface of the protective film 5 is increased, so that when the adhesive resin is applied on the protective film 5 in the next step, bubbles, As in the first embodiment, it is possible to prevent the occurrence of voids and thickness unevenness.

<Fig. 3 (4)>
Next, if necessary, the plasma processing for removing the residual etching gas adsorbed on the etching surface of the protective film 5 in the etching described above is the same as in the first embodiment. When plasma processing is performed, it may be performed in the same manner as in the first embodiment.

<Fig. 3 (5)>
Next, the sealing substrate 9 is bonded to the protective film 5 side of the element substrate 1 through the adhesive resin 7. This step may be performed in the same manner as the procedure in any of the first to third examples described in the first embodiment. Thereby, the display device 11 in which the organic electroluminescent elements 3 are arranged on the element substrate 1 is completed.

  Even in the manufacturing method of the second embodiment described above, the protective film 5 is formed with a sufficient film thickness in the process described with reference to FIG. 3B, and the following FIG. In the etching process described above, the protective film 5 is thinned, and this etching process and the following FIGS. 3 (4) to 3 (5) are performed in an atmosphere controlled continuously. For this reason, as in the first embodiment, it is possible to prevent the occurrence of dark spots due to the intrusion of moisture or oxygen into the organic electroluminescent element 3 during the manufacturing process. And even if it is the structure which bonded the sealing substrate 9 through the protective film 5 fully thinned without enlarging manufacturing equipment, in the state which sealed the organic electroluminescent element 3 reliably Thus, the display device 11 suitable for the top emission type in which the light emitted from the organic electroluminescence element 3 is extracted through the thin protective film 5 can be obtained at a low cost and with a good yield. .

  In addition, in the manufacturing method of the second embodiment, the protective film 5 on the outermost peripheral portion of the element substrate 1 is removed in the step of thinning the protective film 5 by etching. 5 is not exposed. That is, only the interface between the element substrate 1 and the adhesive resin 7 and the interface between the adhesive resin 7 and the sealing substrate 9 are exposed on the outer periphery of the display device 11. Therefore, the interface of the protective film 5, which is generally a moisture and oxygen infiltration path, does not exist in the outer peripheral portion, and the supply of moisture and oxygen to the organic electroluminescent element 3 can be cut off.

  As a result, it is possible to obtain the display device 11 capable of preventing the occurrence of dark spots due to the intrusion of oxygen or moisture after manufacture.

It is sectional process drawing explaining the manufacturing method of 1st Embodiment. It is a graph which shows the time change of the light emission area of an organic electroluminescent element for every film thickness of a protective film. It is sectional process drawing explaining the manufacturing method of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Element board | substrate, 1a ... Display area, 1b ... Peripheral area | region, 3 ... Organic electroluminescent element, 5 ... Protective film, 7 ... Adhesive resin, 9 ... Sealing substrate, 11 ... Display apparatus, 21 ... Mask,

Claims (5)

A first step of forming an organic electroluminescent element on the element substrate;
A second step of forming a protective film on the element substrate in a state of covering the organic electroluminescent element;
A third step of thinning the protective film by etching;
A method for manufacturing a display device, comprising: performing a fourth step of attaching a sealing substrate to the protective film side via an adhesive resin in an atmosphere controlled continuously with the third step. In the manufacturing method of the display device according to claim 1,
The method of manufacturing a display device, wherein the second step is performed in an atmosphere controlled continuously with the first step. In the manufacturing method of the display device according to claim 1,
The plasma treatment for removing the residual etching gas in the etching of the third step is performed between the third step and the fourth step in an atmosphere controlled continuously with these steps. A method for manufacturing a display device, characterized by: In the manufacturing method of the display device according to claim 1,
In the second step, a mask having a shape that opens the display region in which the organic electroluminescent element is formed and covers a peripheral region of the display region is disposed opposite to the element substrate, and the deposition is performed by vapor deposition from the mask. Forming the protective film so as to cover the display area;
In the third step, the protective film is etched until at least the protective film portion formed around the peripheral region is removed. In the manufacturing method of the display device according to claim 1,
In the third step, etching is performed so that the protective film is planarized. A method for manufacturing a display device, wherein:

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