JP5910357B2 - Method for producing structure having functional film - Google Patents

Description

  The present invention relates to a structure having a functional film such as an organic layer in organic EL (electroluminescence), and in particular, a structure having a functional film formed by applying ink on a substrate to form the functional film. It relates to a manufacturing method.

  Conventionally, as a method of manufacturing this type of structure, in a state where the coating mask is in close contact with the surface of the base material, ink serving as a functional film is applied in the opening of the coating mask and dried. Thus, a method of forming a functional film has been proposed (see, for example, Patent Document 1).

JP 2011-48915 A

  By the way, in the ink applied on the substrate, the peripheral portion is easily formed thinner than the central portion due to the fluidity and surface tension of the ink. Therefore, when the ink is dried, drying proceeds from a thin portion around the ink, and undried ink flows from the central portion. If it does so, the film thickness of the said ink peripheral part will become thick, and it will be easy to become non-uniform in thickness in the ink after drying, ie, a functional film.

  If the thickness of the functional film becomes non-uniform in this way, for example, when the functional film is an organic EL light emitting layer, problems such as uneven light emission are likely to occur when the organic EL emits light. .

  The present invention has been made in view of the above-described problems, and in a method for manufacturing a structure having a functional film formed by applying ink to be a functional film on a substrate. The object is to prevent the functional film from becoming nonuniform as much as possible.

In order to achieve the above object, the invention according to claim 1 includes a base material (10) and functional films (30, 40) provided on the base material, and the functional film includes the functional film and the functional film. A method for producing a structure having a functional film that is formed by applying an ink (K) to a substrate and drying the ink (K),
A bank forming step of forming an annular bank (60) surrounding the film forming region (10a) on which the functional film is formed on the base material, and a bank in the bank so as to rise higher than the tip (61) of the bank a coating step of applying the ink to the film formation region, a one side flat surface (201), together with the peripheral portion of the film forming region having an opening (210) on the center side of the shielded and the film forming region The lid (200) made of a magnetic material and having a liquid repellent surface is used, the flat surface of the lid is opposed to the base material, and the flat surface of the lid contacts the tip of the bank by the magnetic force from the base material side. Until the lid contact step of pressing the ink on the film forming region by the flat surface of the lid, and the drying step of drying the ink by evaporating the liquid component in the ink through the opening of the lid to form the functional film, It is characterized by comprising

  According to this, in the lid contact step, the peripheral side of the ink on the film formation region is pressed by the flat surface of the lid, and the central side of the ink protrudes into the opening of the lid. The central side of the ink on the film formation region is raised in the opening of the lid, but the peripheral side is pressed by the flat surface of the lid and has a film thickness substantially the same as the height of the bank. It becomes. That is, in the ink, the central portion side positioned at the opening is slightly thicker than the peripheral portion other than the opening, but a uniform film thickness is realized on the peripheral portion.

  In the drying process, since the ink is dried through the opening, the drying speed is faster on the center side of the ink where the opening is located than on the peripheral side of the ink. Since the part on the peripheral part side, which is thinner than the part side, is shielded by the lid, the progress of drying is slow. Therefore, it is possible to suppress the flow of undried ink to the portion on the ink peripheral portion side as in the prior art.

  Therefore, according to the present invention, it is possible to prevent the functional film thickness from becoming nonuniform as much as possible, and it is easy to realize a uniform film thickness over the entire inner periphery of the bank, that is, the entire functional film.

  Here, as in the invention described in claim 2, it is preferable that the opening has a shape in which the opening density is larger on the central side than on the peripheral side of the film formation region in the opening. . According to this, it is possible to increase the ink drying speed further on the center side among the openings located on the center side of the film formation region.

  In addition, the code | symbol in the bracket | parenthesis of each means described in the claim and this column is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

(A) is a figure which shows schematic plan structure of the organic EL element as a structure concerning 1st Embodiment of this invention, (b) is the outline of the part along the dashed-dotted line AA in (a). It is sectional drawing. It is process drawing which shows the principal part process in the manufacturing method of the organic EL element shown by FIG. FIG. 3 is a process diagram illustrating a main process subsequent to FIG. 2. (A) is a schematic plan view which shows the 1st example of the opening part shape in the lid concerning 2nd Embodiment of this invention, (b) is a schematic plan view which shows a 2nd example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, parts that are the same or equivalent to each other are given the same reference numerals in the drawings for the sake of simplicity.

(First embodiment)
The structure S1 according to the first embodiment of the present invention will be described with reference to FIG. In the present embodiment, the organic EL element S1 will be described as an example of the structure. The organic EL element S1 has organic layers 30 and 40 made of an organic EL material as a functional film.

  This organic EL element S1 is typically formed by sequentially laminating a lower electrode 20, a hole injection layer 30, a light emitting layer 40, and an upper electrode 50 on one surface of an electrically insulating substrate 10 made of a transparent glass substrate or the like. Have a laminated structure. In addition to the above layers, it is needless to say that a hole transport layer, an electron transport layer, or the like may be interposed between the layers.

  Here, the organic EL element S1 is configured as a display element having a segment type pixel P1. Specifically, a region defined by the annular bank (partition wall) 60 constitutes one pixel P1, and each pixel P1 is constituted by a stacked structure of the above layers 20 to 50.

  Although not particularly limited, the bank 60 is formed on the lower electrode 20 formed in a solid state on one surface of the substrate 10, and the layers 30 to 50 on the lower electrode 20 are formed in the bank 60. 1 pixel P1 is defined. On the outside of the bank 60, the hole injection layer 30, the light emitting layer 40, and the upper electrode 50 are not formed on the lower electrode 20, and are not pixels.

  In the example of FIG. 1, the number “8” is formed by seven pixels P <b> 1. In this case, the light emitting layer 40 emits light by applying a voltage between the lower electrode 20 and the upper electrode 50 from an external circuit via an unillustrated wiring or the like.

  Then, the numbers “0” to “9” can be displayed by selectively lighting the seven pixels P1. Here, the light from the light emitting layer 40 is extracted, for example, from the substrate 10 side.

  Specifically, the lower electrode 20 is made of a typical transparent electrode material such as ITO (indium-tin-oxide) formed by sputtering or the like. In the present embodiment, both the hole injection layer 30 and the light emitting layer 40 are formed by applying and drying ink as a material.

  For example, the hole injection layer 30 is made of polyethylene dioxythiophene PEDOT as a conductive polymer and polystyrene sulfonate PSS (hereinafter abbreviated as “PEDOT / PSS”) as a dopant. In this case, the ink used as the material of the hole injection layer 30 is an organic solution obtained by adding a high boiling point solvent to the PEDOT / PSS dispersed in water.

  The light emitting layer 40 is made of, for example, a conjugated polymer such as a polyphenylene vinylene polymer or a polyfluorene polymer as an electron transporting light emitting material. In this case, the ink used as the material of the light emitting layer 40 is an organic solution obtained by adding these polymers to a high boiling point solvent.

  And as the upper electrode 50, the film | membranes, such as aluminum formed by vapor deposition etc., are mentioned, for example. The bank 60 is made of, for example, an electrically insulating resin such as polyimide, and such a bank 60 is formed using a photolithographic technique. Here, each bank 60 has a hexagonal ring shape.

  Next, with reference to FIG. 2 and FIG. 3, the manufacturing method of organic EL element S1 concerning this embodiment is described. 2 and 3 are process diagrams for a method of forming the organic layers 30 and 40 in the organic EL element S1, but the illustration of the lower electrode 20 on the substrate 10 is omitted.

  First, a film forming apparatus for the organic layers 30 and 40 shown in FIG. 2 will be described. This film forming apparatus mainly includes a nozzle 100 that discharges ink K, a stage 110 that supports and moves the substrate 10, a control unit (not shown) that includes a computer that controls the operation of the nozzle 100 and the stage 110, and the like. have.

  The nozzle 100 has a function of dropping ink K, which is a material of the organic layers 30 and 40, onto the substrate 10 mounted and fixed on the stage 110. Here, the nozzle 100 and the stage 110 are scanned by the control unit (not shown) so that the relative positions of the nozzle 100 and the stage 110 are in a desired positional relationship.

  Thereby, the ink K is dripped at the target position. In addition, the nozzle 100 can control the on / off of the discharge of the ink K and the discharge amount of the ink K by the control unit (not shown).

  In the manufacturing method of the present embodiment, first, the lower electrode 20 made of a film of ITO or the like is formed on the substrate 10 by sputtering or vapor deposition.

  Next, as shown in FIG. 2A, an annular bank 60 surrounding the film forming region 10a where the hole injection layer 30 as the functional film is formed is formed on the substrate 10 (bank forming step). ). As described above, the bank 60 is formed by a photolithographic method or the like using an insulating resin, and protrudes from the substrate 10 side.

  Here, the outline of one film formation region 10a substantially corresponds to the outline of one pixel P1. Although not shown in FIGS. 2 and 3, a lower electrode 20 is formed on the substrate 10, and the surface of the film formation region 10 a is constituted by the lower electrode 20.

  That is, the bank 60 is formed in a portion of the surface of the lower electrode 20 that is an outline of the film forming region 10a, and the inner shape of the bank 60 corresponds to the outer shape of the film forming region 10a. . Then, as shown in FIG. 2A, the substrate 10 on which the lower electrode 20 and the bank 60 are formed is mounted on the stage 110 and fixed.

  Next, as shown in FIG. 2B, the ink K is applied to the film forming region 10a in the bank 60 so as to rise higher than the tip end portion 61 of the bank 60 (application step). Here, the ink K to be the hole injection layer 30 is applied to the film formation region 10a. As the ink K used as the hole injection layer 30, an organic solution obtained by adding the above-described PEDOT / PSS to a solvent is used.

  Specifically, in the coating process, the nozzle 100 is positioned on the film formation region 10a, the ink K is ejected from the nozzle 100, and dropping is performed. Thereby, the ink K is applied onto the film forming region 10a.

  Here, the nozzle 100 may be any nozzle that discharges the ink K and applies it onto the film forming region 10a, and the discharge form is not particularly limited. For example, what is sprayed as an inkjet may be used, and what is dripped like a dispense may be used.

  Then, after applying the ink K to one film forming region 10a, the nozzle 100 is positioned on the next film forming region 10a, and the applying process is similarly performed. And this application | coating process is performed about each film formation area | region 10a, and the ink K used as the positive hole injection layer 30 is apply | coated to all the film formation area | regions 10a.

  Next, as shown in FIGS. 3A and 3B, a lid contact process is performed. In this lid contact process, a lid 200 having a flat surface 201, shielding the periphery of the film formation region 10a and having an opening 210 on the center of the film formation region 10a is used.

  In this lid contact process, the flat surface 201 of the lid 200 is opposed to the base material 10, and the film formation region is formed by the flat surface 201 of the lid 200 until the flat surface 201 of the lid 200 contacts the tip portion 61 of the bank 60. The ink K on 10a is pressed. Specifically, the lid 200 is placed on the front end portion 61 of the bank 60 so as to cover the film forming region 10 a with the lid 200. 3A is a diagram showing a schematic plane on the flat surface 201 side of the lid 200 in FIG. 3B.

  The lid 200 is a plate material made of a magnetic material such as an iron-based metal such as stainless steel. In this case, for example, by providing a magnetic force generation mechanism such as an electromagnet below the stage 110, the lid 200 is attracted to the substrate 10 side by the magnetic force and is fixed in close contact with the bank 60. The lid 200 may be fixed to the substrate 10 by a clamp mechanism or the like, and in this case, a material other than the magnetic material can be appropriately selected.

  Here, in the lid 200 of the present embodiment, the peripheral side of the film forming region 10a is shielded and the opening 210 is provided on the central side of the film forming region 10a. Therefore, as shown in FIG. 3B, the peripheral side of the ink K on the film formation region 10a is pressed by the flat surface 201 of the lid 200, and the central side of the ink K is the opening of the lid 200. It protrudes into the part 210.

  As shown in FIG. 3B, in the lid contact step, the center side of the ink K on the film formation region 10a is raised in the opening 210 of the lid 200. The part side is pressed by the flat surface 201 of the lid 200 and has a film thickness substantially the same as the height of the bank 60. That is, the portion of the ink K located in the opening 210 in the center of the lid 200 is slightly thicker than the portion of the ink K other than the opening 210, but the uniform film is formed in the portion of the ink K other than the opening 210. Thickness is realized.

  Next, as illustrated in FIG. 3C, the ink K is dried while the lid 200 is in contact with the bank 60. In this drying step, drying is performed at room temperature or by heating. As the heat drying, for example, the substrate 10 is placed in an oven or hot plate in a high temperature (for example, about 150 ° C.) atmosphere to perform drying.

  At this time, in the drying step, the ink K is dried by evaporating the liquid component in the ink K through the opening 210 of the lid 200. Thus, the dried ink K is formed as the hole injection layer 30 as the functional film. FIG. 3C shows the ink K after completion of the drying, and the ink K has a uniform film thickness in the film formation region 10a.

  In this way, the hole injection layer 30 is formed. Subsequently, the light emitting layer 40 is also the same as the hole injection layer 30 by using the ink K to be the light emitting layer 40 and the same lid 200 as the hole injection layer 30. An application process, a lid contact process, and a drying process are performed. As the ink K used as the light emitting layer 40, for example, an organic solution obtained by adding the above-described conjugated polymer to a solvent is used. Thereby, the light emitting layer 40 is completed.

  Thus, after the light emitting layer 40 is formed, the lid 200 is removed, and then the upper electrode 50 is formed. As described above, the upper electrode 50 is formed by vapor deposition or sputtering. Thus, by forming each pixel P1, the organic EL element S1 of the present embodiment is completed. The above is the manufacturing method of this embodiment.

  By the way, according to the manufacturing method of the present embodiment, in the lid contact step, the center side of the ink K on the film formation region 10a is raised in the opening 210 of the lid 200. Is pressed by the flat surface 201 of the lid 200 and has a film thickness that is substantially the same as the height of the bank 60, so that a uniform film thickness can be achieved at portions other than the opening 210.

  In the drying process, the ink is dried through the opening 210 of the lid 200, and therefore, the central portion side of the ink K where the opening portion 210 is located is more than the peripheral portion side of the ink K shielded by the lid 200. Increases drying speed. In comparison, the peripheral portion of the ink that is thinner than the central portion is shielded by the lid 200, so that the progress of drying is delayed.

  For this reason, it is possible to prevent the undried ink K from flowing to the portion on the peripheral portion side of the ink K as in the prior art, and the film thickness in the peripheral portion of the ink K becoming larger than that on the central portion side. Here, since the central portion side of the ink K is thicker than the peripheral portion side of the ink K by rising in the opening 210 of the lid 200, it is preferable that the drying speed is increased.

  Therefore, according to the present embodiment, it is possible to prevent the film thicknesses of the hole injection layer 30 and the light emitting layer 40 as the functional films from becoming non-uniform as much as possible. A uniform film thickness can be easily realized in the entire organic layers 30 and 40.

  In the present embodiment, it is desirable that the surface of the lid 200, particularly the side surface of the opening 210, has liquid repellency. According to this, since the ink K passing through the opening 210 of the lid 200 is repelled, the ink K does not adhere to the inner surface of the opening 210 and easily falls onto the film forming region 10a. Such a liquid repellent treatment of the lid 200 can be performed, for example, by immersing the lid 200 in a fluorine-based surface treatment agent to form a liquid repellent layer.

  Further, it is desirable that the film forming region 10a has lyophilic properties. Here, it is desirable that the surface of the lower electrode 20 serving as the surface of the film formation region 10a has lyophilicity. According to this, the ink K easily spreads and spreads over the entire film forming region 10a, which is advantageous in terms of uniformizing the thickness of the ink K. Such a configuration can be realized by performing oxygen plasma treatment, UV ozone treatment, or the like on the surface of the lower electrode 20.

  Further, it is desirable that the surface of the bank 60 has liquid repellency. According to this, since the ink K that has spread to the bank 60 is difficult to scoop up the bank 60, it is easy to prevent the peripheral portion of the ink K from becoming thicker than necessary. Such a configuration is realized by applying a plasma treatment to the bank 60 using a fluorinated gas such as carbon tetrafluoride.

  In the present embodiment, “liquid repellency” is defined as a state where the contact angle is 50 ° or more when the ink K is dropped on the substrate 10 and the contact angle is measured. To do. Further, “lyophilic” with respect to “liquid repellency” is defined as a state in which the contact angle is 40 ° or less in the present embodiment.

  That is, in the present embodiment, it is preferable that the surface of the film forming region 10a to which the ink K is applied has higher wettability with respect to the ink K than the surface of the lid 200 and the surface of the bank 60. According to this, it becomes easy to make the film thickness of the ink K uniform throughout the ink K.

  Further, in order to realize a uniform film thickness of the entire ink K, the substrate 10 may be vibrated by applying ultrasonic vibration between the coating process and the drying process (substrate vibration process). According to this, the applied ink K is easily spread by the vibration of the substrate 10, so that the film thickness can be easily made uniform.

  Further, in the drying process, vacuuming may be performed by using a sealed oven or the like, and the ink K on the substrate 10 may be dried in a reduced pressure atmosphere. According to this, there is an advantage that drying is promoted.

(Second Embodiment)
The second embodiment of the present invention provides a lid 200 having an opening 210 shape different from that of the first embodiment. In the lid 200, the opening 210 is, for example, hexagonal in the first embodiment, and the opening 210 has a uniform opening density.

  On the other hand, in this embodiment, the opening density provided on the central portion side of the film forming region 10a has a larger opening density on the central portion side than the peripheral portion side of the film forming region 10a in the opening portion 210. It is assumed to be a shape.

  According to this, there is an advantage that the drying speed of the ink K can be further increased in the central portion side among the opening portions 210 located on the central portion side of the film forming region 10a. The opening density is, of course, the opening density per unit area in the film forming region 10a in the bank 60.

  In the first example shown in FIG. 4A, the opening 210 located at the center of the film formation region 10a of the lid 200 is formed by an assembly of a plurality of holes. The large hole 210a is provided, and a plurality of small small holes 210b are provided on the peripheral side so as to surround the large hole 210a. Thereby, this opening part 210 shall satisfy | fill the relationship of the above-mentioned opening density.

  In the second example shown in FIG. 4B, the opening portion 210 of the lid 200 is composed of one piece, and this opening portion 210 is opened at the center of the film forming region 10a. The size of the opening is large, and the opening is narrow on the peripheral side. Thereby, this opening part 210 shall satisfy | fill the relationship of the above-mentioned opening density.

(Other embodiments)
In each of the above embodiments, both the hole injection layer 30 and the light emitting layer 40 are formed by applying and drying ink as a material. Only one of them may be formed by applying ink as a material and drying it. Even in that case, it is needless to say that the manufacturing method of each of the above embodiments can be applied.

  Moreover, as the opening part 210 of the lid | cover 200, what was provided in the said lid | cover 200 so that the center part side of the film | membrane formation area 10a may be opened and the surrounding peripheral part side may be shielded with the lid | cover 200, The opening shape of the opening 210 is not limited to the shapes shown in the above drawings, and various other shapes are possible.

  Moreover, as the lid | cover 200, it is good also as what can control the temperature of lid | cover 200 itself. For example, the lid 200 may be made of a metal that generates heat when energized. Accordingly, in the ink K application process, the temperature of the lid 200 can be adjusted to control the viscosity of the ink K to an appropriate state.

  In the above embodiment, the organic EL element S1 has the segment type pixel P1, but the organic EL element has a dot matrix type pixel in which the shape of the film formation region 10a is the same size. Good. Also in this case, the above manufacturing method can be applied to the formation of the organic layers 30 and 40.

  Further, as the organic EL element S1, segment type pixels and dot matrix type pixels may be mixed on one substrate 10.

  Moreover, in the said embodiment, although the functional film was the organic layers 30 and 40 of the organic EL element S1, as a functional film, it forms by apply | coating the ink used as a raw material on a base material, and drying it. If it is a thing, it is not limited to this.

  For example, the functional film may be an organic semiconductor film containing pentacene, an organic solar cell, a color filter, or the like. Furthermore, the functional film may be made of an inorganic film, if possible, other than the organic film.

  In addition, the base material on which the functional film is formed is not limited to an insulating plate-like material such as the substrate 10, and various materials can be used as long as they have shapes and materials that can be formed into a film. Things are applicable.

  In addition to the combination of the above-described embodiments, the above-described embodiments may be appropriately combined within the possible range, and the above-described embodiments are not limited to the illustrated examples.

DESCRIPTION OF SYMBOLS 10 Substrate 10a Film formation area 30 Hole injection layer as functional film 40 Light emitting layer as functional film 60 Bank 61 Bank tip 200 Lid 201 Lid flat surface 210 Lid opening K ink

Claims (2)

A substrate (10);
Functional films (30, 40) provided on the base material,
The functional film is a method for producing a structure having a functional film that is formed by applying the ink (K) to be the functional film on the substrate and drying it.
A bank forming step of forming an annular bank (60) surrounding the film forming region (10a) on which the functional film is formed on the substrate;
An application step of applying the ink to the film forming region in the bank so as to rise higher than the tip (61) of the bank;
One surface is a flat surface (201), the peripheral portion side of the film forming region is shielded and the central portion side of the film forming region has an opening (210), and the surface is made of a magnetic material and the surface is liquid repellent Using a lid (200) with
The flat surface of the lid is opposed to the base material, and the flat surface of the lid is on the film formation region by the magnetic force from the base material side until the flat surface of the lid contacts the tip of the bank. A lid contact step for pressing the ink;
And a drying step of drying the ink by evaporating a liquid component in the ink through the opening of the lid to form the functional film, thereby producing a structure having a functional film. Method.   2. The functional film according to claim 1, wherein the opening has a shape in which an opening density is larger on a central side than on a peripheral side of the film forming region in the opening. Manufacturing method of structure.

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