TW202034489A - Metal shadow mask and manufacturing method thereof - Google Patents

Abstract

Disclosed in the present application is a metal shadow mask. A manufacturing method of the metal shadow mask comprises the steps of: providing a stencil, lamination, exposure and development, electroforming, lamination, exposure and development, etching and removal, etc., to obtain the metal shadow mask having a plurality of perforations. By controlling the depth and angle in the perforations during the preparation process, the metal shadow mask possessing high opening precision and having an angle in the opening can be attained, so that evaporation shadows can be reduced or eliminated while in use.

Description

Metal shadow mask and preparation method thereof

The invention relates to the technical field of organic light emitting diode display, in particular to a metal shadow mask and a preparation method thereof.

An organic light-emitting diode (Organic Light-Emitting Diode, OLED) display device is a thin-film light-emitting device made of organic semiconductor materials and driven by a direct current voltage. Since OLED display devices have the advantages of thin thickness, light weight, high contrast, and wide viewing angles, they have been listed as the next-generation mainstream display technology.

The light-emitting principle of an OLED display device is that when a current passes through the organic light-emitting material coating, the organic light-emitting material coating emits light. At present, in the field of OLED manufacturing in the industry, a single-layer evaporation method is generally used for shadow mask evaporation. During evaporation, organic material particles pass through the opening of the shadow mask from various angles and adhere to the substrate. However, in a general vapor deposition process, the openings distributed on the shadow mask have no taper. When particles are shot obliquely toward the opening, some of the particles will be blocked by the opening wall and cannot reach the substrate, resulting in missing obliquely incident particles, resulting in evaporation of the substrate. Non-uniformity and shadowing effect will reduce the brightness of the product, thereby affecting the display characteristics of the OLED device.

In view of the shadow effect, the industry generally adopts double-sided etching of metal coils when manufacturing shadow masks for OLEDs, but this method cannot accurately control the uniformity of the opening size. The opening of the contact surface between the shadow mask and the indium tin oxide (ITO) surface has an inverted cone angle, resulting in a dead angle area, which affects the evaporation quality.

The object of the present invention is to provide a metal shadow mask and a preparation method thereof, which are used to solve the problem that the shadow effect is easily generated during the evaporation of the glass substrate.

In order to solve the above problems, the present invention provides a method for manufacturing a metal shadow mask, which includes: providing a template; arranging a photosensitive film on the template; exposing and developing, so that the photosensitive film forms a plurality of first structures on the template; and forming a metal layer on the template. On the template; set the photosensitive film on the metal layer; exposure and development, so that the photosensitive film forms a plurality of second structures on the metal layer, wherein the plurality of second structures and the plurality of first structures are staggered, and each second structure and The adjacent first structures are separated by a distance; the metal layer is etched; and the multiple first and second structures are removed to obtain a metal shadow mask with multiple perforations.

The present invention also provides a metal shadow mask manufactured by the above manufacturing method.

Compared with the prior art, the present invention can obtain the following technical effects:

In the method for preparing a metal shadow mask provided by the present invention, the depth and angle of the opening can be controlled during the preparation process, so that a metal shadow mask with high opening accuracy and angles in the opening can be obtained, so that it can be used in vapor deposition applications. Reduce or eliminate vapor deposition shadows. At the same time, during evaporation, the loss of organic material particles incident on the glass substrate can be reduced, and the uniformity of evaporation and the decrease of product brightness can be improved and improved.

The following describes the implementation of the present invention in detail with the drawings and embodiments, so as to fully understand and implement the implementation process of how the present invention uses technical means to solve technical problems and achieve technical effects.

For example, certain words are used to refer to specific components in the specification and request items. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and the claim items do not use the difference in names as a way to distinguish components, but use differences in the functions of the components as the criteria for distinguishing. If the "include" mentioned in the entire specification and the request is an open term, it should be interpreted as "include but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range, and basically achieve the technical effect. In addition, the term "coupled" or "electrically connected" herein includes any direct and indirect electrical coupling means. Therefore, if it is described in the text that a first device is coupled to a second device, it means that the first device can be directly electrically coupled to the second device, or indirectly electrically coupled through other devices or coupling means. Connected to the second device. The following description of the specification is a preferred embodiment for implementing the present invention, but the description is for the purpose of explaining the general principles of the present invention and is not intended to limit the scope of the present invention. The protection scope of the present invention shall be subject to those defined by the appended claims.

It should also be noted that the terms "include", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, product or system including a series of elements not only includes those elements, but also includes Other elements that are not explicitly listed, or include elements inherent to the process, method, commodity, or system. If there are no more restrictions, the element defined by the sentence "including a..." does not exclude the existence of other identical elements in the process, method, product, or system that includes the element.

Example description

As shown in FIG. 1, in an embodiment of the present invention, the method for manufacturing a metal shadow mask includes:

Step S101: Provide a template. It can be a clean template that has undergone a pretreatment process, or it can be cleaned with an acidic cleaning agent and an alkaline cleaning agent before this step, then rinsed with deionized water, and then dried for use.

Step S103: Set a photosensitive film on the template. A roller with a certain temperature is mainly used to press the photosensitive film 20 onto the template 10 with a certain pressure, so that the photosensitive film 20 is fully attached to the surface of the template 10 (as shown in FIG. 2).

Step S105: exposing and developing, so that the photosensitive film forms a plurality of first structures on the template. 2 and 3, in this step, the template 10 pressed with the photosensitive film 20 is exposed to form a first layer pattern according to the exposure pattern; then the exposed template 10 is baked at a certain temperature to make the exposed The photosensitive film 20 is fully reacted; then, the exposed template 10 is developed, so that the photosensitive film 20 forms a plurality of first structures 30 on the surface of the template 10 (that is, the dry film of the photosensitive film 20 after exposure and development), and a plurality of first The structures 30 are spaced apart from each other.

Among them, the template 10 with multiple first structures 30 can also be selectively subjected to a hard bake or UV curing process, so that the developed template 10 is baked at a higher temperature, thereby making the multiple first structures 30 stronger , Stronger adhesion on the surface of the template.

Step S107: forming a metal layer on the template. As shown in FIG. 4, electroplating is performed on the template 10 with a plurality of first structures 30, so that a metal layer 40 is deposited on the surface of the template 10 where the first structures 30 are not provided.

Step S109: setting the photosensitive film on the metal layer. In this step, a laminating procedure is performed on the template 10 provided with the metal layer 40. The photosensitive film 20 is pressed onto the metal layer 40 under a certain pressure with a roller with a certain temperature, so that the photosensitive film 20 and the metal layer 40 The surface is fully attached (as shown in Figure 5). In addition, before performing this step, the template 10 provided with the metal layer 40 can be selectively cleaned and dried, for example, rinsed with deionized water, the template 10 is dried, and then the photosensitive film 20 is applied. The laminating procedure.

Step S111: Exposure and development, so that the photosensitive film forms a plurality of second structures on the metal layer, wherein the plurality of second structures and the plurality of first structures are arranged alternately, and each second structure is between the adjacent first structures Spaced apart. Referring to FIGS. 5 and 6, in operation, the template 10 on which the photosensitive film 20 is pressed is exposed, so that the photosensitive film 20 forms a second layer pattern on the metal layer 40 according to the exposure pattern. Next, the exposed template 10 is baked at a certain temperature to fully react the exposed photosensitive film 20. After that, the exposed template 10 is developed to form a plurality of second structures 50 on the photosensitive film 20 (that is, a dry film after the photosensitive film 20 is exposed and developed). The plurality of second structures 50 and the plurality of first structures 30 are arranged alternately, and each second structure 50 is separated from the adjacent first structure 30 by a distance ΔW, so that there is a gap between the first structure 30 and the second structure 50 A part of the metal layer 40 is exposed.

In this step, since the photosensitive film 20 is used for lamination, exposure and development to complete the arrangement of the first structure 30 and the second structure 50, the distance ΔW between the first structure 30 and the second structure 50 can be controlled at It is within the range of 1.5um or less, and has high alignment accuracy. The higher the alignment accuracy, the higher the alignment accuracy, it will help to obtain a structure with the same depth and angle in the subsequent etching step. In addition, the position accuracy of the opening can be ensured in the subsequent steps, which is beneficial for making a small opening metal shadow mask.

Similar to the previous step, after this step, the template 10 can be selectively cured by hard baking or UV curing, so that the developed template 10 can be baked at a higher temperature to make the multiple second structures 50 stronger and Stronger adhesion.

Step S113: etching the metal layer. 6 and 7, the metal layer 40 exposed between the first structure 30 and the second structure 50 is etched using a metal etching solution, and the etching process parameters are controlled to obtain the expected etching depth and/or angle . The etching depth may be close to or equal to the thickness of the metal layer 40. For example, if the thickness of the metal layer 40 is 8-100 um, the difference between the etching depth and the thickness of the metal layer 40 may be equal to or less than 1 um. At the same time, the angle of the etching surface can be precisely controlled by controlling the distance ΔW between the first structure 30 and the second structure 50 and the etching depth, so that a groove with a wide upper and a narrow bottom is etched in the metal layer 40 corresponding to the distance ΔW. 60, and a guiding surface 41 is formed on the side of the metal layer 40 adjacent to the first structure. The guiding surface 41 can be an inclined surface or a curved surface.

Step S115: Remove the multiple first and second structures to obtain a metal shadow mask with multiple perforations. Please refer to Figures 7 and 8. In this step, the template 10 with multiple first and second structures 30, 50 is put into the film unwinding groove to remove the photosensitive film on the template 10 , The multiple first and second structures 30, 50 are removed from the template 10. Afterwards, the template 10 after the film removal can be selectively cleaned and dried, and then the metal shadow mask 70 is removed from the template and fixed.

After the first structure 30 is removed, a plurality of perforations 42 are formed at intervals on the metal layer 40 corresponding to the position of the first structure 30, and each perforation 42 forms a first opening 43 on two opposite sides of the metal layer 40. Compared with the second opening 44, the size of the opening can reach about 10um. In addition, since the previous etching step formed a groove 60 with a wide top and a narrow bottom between the metal layer 40 and the first structure 30, the aperture of the through hole 42 was gradually reduced along the second opening 44 toward the first opening 43, and A structure in which the diameter of the second opening 44 is larger than that of the first opening 43 is formed. At the same time, in the horizontal direction, the guiding surface 41 formed by the metal layer 40 in the through hole 42 may be an inclined surface that is inclined toward the first opening 43 along the second opening 44, or may be concave toward the first opening 43 along the second opening 44. Surface.

After the above-mentioned film removal procedure, the template 10 after the film removal can be selectively cleaned and dried. Finally, the metal shadow mask 70 is removed from the template 10 and fixed.

Referring to FIGS. 8 and 9, in an embodiment of the present invention, the metal shadow mask 70 manufactured by the above-mentioned process includes a metal layer 40. The metal layer 40 may be made of nickel alloy, nickel-iron alloy or iron. Nickel-cobalt alloy, but not limited to this. The metal layer 40 has a plurality of through holes 42, each through the first surface 401 and the second surface 402 opposite to the metal layer 40, and a first opening 43 is formed on the first surface 401 and a second opening 44 is formed on the second surface 402. . The second opening 44 communicates with the first opening 43, and the diameter of the second opening 44 is larger than the diameter of the first opening 43. In addition, the metal layer 40 has a guide surface 41 in each of the through holes 42. The guide surface 41 may be an inclined surface that is inclined toward the first opening 43 along the second opening 44, or may be concave along the second opening 44 toward the first opening 43. Surface. Wherein, the metal layer 40 has an included angle θ between the edge of the first opening 43 and the line connecting the metal layer 40 at the edge of the second opening 44 and the first surface 401 or the second surface 402 of the metal layer 40, and the included angle The angle of θ is between 30 and 60°. Therefore, during evaporation, the organic material particles can have a better incident angle, and the shadow effect can be reduced or eliminated.

The above description shows and describes several preferred embodiments of the present invention, but as mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as the exclusion of other embodiments, but can be used in various Other combinations, modifications, and environments can be modified through the above teachings or technology or knowledge in related fields within the scope of the inventive concept described herein. The modifications and changes made by those skilled in the art do not depart from the spirit and scope of the present invention, and should fall within the protection scope of the appended claims of the present invention.

S101: Provide a template S103: Set a photosensitive film on the template S105: Exposure and development, so that the photosensitive film forms multiple first structures on the template S107: Form a metal layer on the template S109: Set the photosensitive film on the metal layer S111: Exposure and development, so that the photosensitive film forms multiple second structures on the metal layer S113: etching metal layer S115: Remove multiple first and second structures to obtain a metal shadow mask with multiple perforations 10: template 20: photosensitive film 30: The first structure 40: metal layer 41: guide surface 42: Piercing 43: first opening 44: second opening 401: First Surface 402: second surface 50: second structure 60: Groove 70: Metal shadow mask

Fig. 1 is a flowchart of a method according to an embodiment of the present invention. 2 to 8 are schematic side views corresponding to different production stages in an embodiment of the present invention. 9 is a schematic cross-sectional view of a metal shadow mask according to an embodiment of the present invention.

S101: Provide a template

S103: Set a photosensitive film on the template

S105: Exposure and development, so that the photosensitive film forms multiple first structures on the template

S107: Form a metal layer on the template

S109: Set the photosensitive film on the metal layer

S111: Exposure and development, so that the photosensitive film forms multiple second structures on the metal layer

S113: etching metal layer

S115: Remove multiple first and second structures to obtain a metal shadow mask with multiple perforations

Claims (15)

A method for manufacturing a metal shadow mask includes the following steps: Provide a template; Setting a photosensitive film on the template; Exposure and development, so that the photosensitive film forms a plurality of first structures on the template; Forming a metal layer on the template; Disposing the photosensitive film on the metal layer; Exposing and developing, the photosensitive film forms a plurality of second structures on the metal layer, wherein the second structures and the first structures are arranged alternately, and each second structure is connected to the adjacent first structure. Separated by a gap; Etching the metal layer; and The first and second structures are removed to obtain a metal shadow mask with multiple perforations. The method for manufacturing a metal shadow mask according to claim 1, wherein after the steps of exposure and development, the method further includes the following steps: performing a curing process on the first structures and/or the second structures. The method for manufacturing a metal shadow mask according to claim 1, wherein in the steps of exposing and developing the photosensitive film to form the first structures on the template, the first structures are arranged at intervals. The method for manufacturing a metal shadow mask according to claim 1, wherein after the steps of removing the first and second structures, the method further includes a step of removing and fixing the metal shadow mask from the template. The method for manufacturing a metal shadow mask according to claim 1, wherein after the steps of removing the first structures or removing the second structures, the method further includes cleaning and drying steps of the template after uncoating . The method for manufacturing a metal shadow mask according to claim 1, wherein in the step of etching the metal layer, the part of the metal layer exposed to the pitch is etched, and the etching depth corresponds to the thickness of the metal layer match. The method for manufacturing a metal shadow mask according to claim 6, wherein the difference between the etching depth and the thickness of the metal layer is equal to or less than 1 um. The method for manufacturing a metal shadow mask according to claim 1, wherein the pitch is equal to or less than 1.5um. The method for manufacturing a metal shadow mask according to claim 1, wherein each of the perforations forms a first opening and a second opening that communicate on two opposite sides of the metal layer, and the apertures of the perforations are along the second opening Taper toward the direction of the first opening. The method for manufacturing a metal shadow mask according to claim 9, wherein the metal layer forms a guide surface in each of the through holes, and the guide surface is an inclined surface or a curved surface. The method for manufacturing a metal shadow mask according to claim 9, wherein the metal layer has an angle between the edge of the first opening and the line of the metal layer at the edge of the second opening and the surface of the metal layer , The angle of the included angle is 30~60°. A metal shadow mask is prepared by the method of manufacturing the metal shadow mask of claim 1. The metal shadow mask according to claim 12, wherein each of the perforations forms a first opening and a second opening that communicate on two opposite sides of the metal layer, and the apertures of the perforations are directed toward the first opening along the second opening The direction of an opening tapers. The metal shadow mask according to claim 13, wherein the metal layer forms a guide surface in each of the perforations, and the guide surface is an inclined surface or a curved surface. The metal shadow mask according to claim 13, wherein the metal layer has an included angle between the edge of the first opening and the line of the metal layer at the edge of the second opening and the surface of the metal layer, and the included angle The angle is 30~60°.

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