Mask sheet and method for manufacturing the same

The present disclosure relates to a mask sheet. The mask sheet includes a plurality of mask units. Each mask unit includes an evaporation effective area and a plurality of welding areas that are distributed around the evaporation effective area according to a preset rule. The distribution of the welding areas around the evaporation effective areas of the mask units at the edge of the mask sheet is consistent with the distribution of the welding areas around the evaporation effective areas of the mask units located in the inner region of the mask sheet.

CROSS REFERENCE

The present application is based upon International Application No. PCT/CN2018/093329, filed on Jun. 28, 2018, which is based upon and claims priority to Chinese Patent Application No. 201710890369.8, filed on Sep. 27, 2017, and the entire contents thereof are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to the display technologies, and particularly, to a mask sheet and a method for manufacturing the same.

BACKGROUND

With the development of optical and semiconductor technologies, flat panel displays such as Liquid Crystal Displays (LCDs) and Organic Light Emitting Diode (OLEDs) have dominated in the display field due to their advantages such as light weight and small size, low energy consumption, fast response speed, high color purity, high contrast ratio and so on. In the semiconductor manufacturing processes, the lithography process is a very important, and it mainly functions to copy the pattern of a mask sheet onto a silicon wafer, so as to make preparation for subsequent etching or ion implantation processes.

The mask manufacturing process, such as the Fine Metal Mask (FMM) mode in the related art, is to evaporate an OLED material on a low temperature poly-silicon (LTPS) backplane according to a predetermined procedure, that is, an OLED material which for example emit red light, green light, blue light or the like is evaporated to a predetermined position by using a pattern on the FMM.

It should be noted that the information disclosed in the background section is only for facilitating understanding of the background of the present disclosure, and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

SUMMARY

Arrangements of the present disclosure provide a mask sheet and a method for manufacturing the same.

According to an aspect, there is provided a mask sheet. The mask sheet includes a plurality of mask units. Each of the plurality of mask units includes an evaporation effective area and a plurality of welding areas that are distributed around the evaporation effective area according to a preset rule.

A distribution of the welding areas around evaporation effective areas of mask units that are located at an edge of the mask sheet is consistent with a distribution of the welding areas around evaporation effective areas of mask units that are located in an inner region of the mask sheet.

In an exemplary arrangement of the present disclosure, a plurality of evaporation effective areas are arranged in an array and the plurality of mask units are arranged in an array corresponding to the plurality of evaporation effective areas.

In an exemplary arrangement of the present disclosure, the plurality of mask units have consistent shapes and areas.

In an exemplary arrangement of the present disclosure, the array of the mask units includes a plurality of columns, and distribution of welding areas around evaporation effective areas of mask units that are located at the beginning and the end of each column is consistent with distribution of welding areas around evaporation effective areas of masks that are located at an inside part of each column; and/or the array of the mask units includes a plurality of rows, and distribution of welding areas around evaporation effective areas of mask units that are located at the beginning and the end of each row is consistent with distribution of welding areas around evaporation effective areas of masks that are located at an inside part of each row.

In an exemplary arrangement of the present disclosure, the evaporation effective areas have a shape selected from one or more of circle, ellipse and rectangle.

In an exemplary arrangement of the present disclosure, the mask units have a shape of rectangle.

In an exemplary arrangement of the present disclosure, the plurality of welding areas includes welding areas disposed at four corners of each of the plurality of mask units.

In an exemplary arrangement of the present disclosure, a virtual mask unit area is disposed at an outer side of mask units that are located at the beginning and the end of each column. The outer side is a side away from an inside part of each column. The plurality of welding areas further includes welding areas disposed at two adjacent corners of the virtual mask unit area that are close to the mask units at the beginning and the end of each column. A virtual mask unit area is disposed at an outer side of mask units that are located at the beginning and the end of each row. The outer side is a side away from an inside part of each row. The plurality of welding areas further includes welding areas disposed at two adjacent corners of the virtual mask unit area that are close to the mask units at the beginning and the end of each row.

In an exemplary arrangement of the present disclosure, the mask sheet includes a fine metal mask sheet.

According to another aspect, there is provided a method for manufacturing a mask sheet. The method includes forming a plurality of mask units, each of which includes an evaporation effective area. The method includes forming a plurality of welding areas around the evaporation effective area according to a preset rule. A distribution of the welding areas around the evaporation effective area of mask units that are located at an edge of the mask sheet is consistent with a distribution of the welding areas around the evaporation effective area of mask units that are located in an inner region of the mask sheet.

Other features and improvements of the present disclosure will be discussed in the following detailed description, or will be acquired partially by practicing the present disclosure.

It is appreciated that the above general description and the following detailed description are intended to be illustrative and exemplary, but not restrictive.

DETAILED DESCRIPTION

Example arrangements will now be described more fully with reference to the accompanying drawings. However, the example arrangements can be embodied in a variety of forms and should not be construed as being limited to the examples set forth herein; rather, these arrangements are provided so that the present disclosure will be more comprehensive and complete, and the conception of the example arrangements will be conveyed to those skilled in the art fully. The described features, structures, or characteristics may be combined in one or more arrangements in any suitable manner. In the following description, numerous specific details are set forth to facilitate understanding of arrangements of the present disclosure. However, one skilled in the art will appreciate that the technical solutions of the present disclosure may be implemented when one or more of the specific details are omitted, or other methods, components, devices, steps, and the like may be employed. In other instances, the well-known technical solutions would not be shown or described in detail so as to avoid various aspects of the present disclosure to be obscured.

Although the relative terms such as “upper” and “lower” are used in the specification to describe the relative relationship of one component in a figure to another component, these terms are used in this specification for convenience only, for example, according to a direction as described in the examples of the accompanying drawings. It will be understood that if a device in a figure is flipped upside down, an upper component described above will become a “lower” component. When a structure is referred to as being “on” another structure, it is possible that the structure is integrally formed on the another structure, or that the structure is “directly” disposed on the another structure, or that the structure is “indirectly” disposed the another structure through other structure(s).

The terms “a”, “an”, “the” and “said” mean the presence of one or more elements/components, or the like; the terms “including” and “having” should be understood in an open sense and means that there may be additional elements/components in addition to the listed elements/components. The terms “first”, “second” and the like are used to distinguish different objects but not for limiting the number of objects.

During mask manufacturing processes, wrinkles may occur on a surface of a FMM sheet after the FMM sheet is stretched, which will affect the flat state of the evaporation effective area, thus affecting the quality of the evaporated product.

Therefore, it is necessary to develop a mask sheet and a method for manufacturing the same to improve the wrinkles of the mask sheet after the mask sheet is stretched, thus improving the quality of the evaporated product.

FIG. 1shows a schematic diagram of a mask sheet according to an exemplary arrangement of the present disclosure, which schematically illustrates a distribution of welding areas that are optimized aiming at wrinkles on effective areas of an FFM sheet;FIG. 2schematically shows a schematic diagram illustrating a distribution of welding areas that are further optimized aiming at wrinkles on effective areas at the edge of the FFM sheet inFIG. 1according to an exemplary arrangement of the present disclosure.

There is proposed a mask sheet in the exemplary arrangement. Referring toFIGS. 1 and 2, the mask sheet includes a plurality of mask units10. Each mask unit10may include an evaporation effective area101and a plurality of welding areas102that are distributed around the evaporation effective area according to a preset rule. The distribution of the welding areas around evaporation effective areas101of mask units10which are located at an edge of the mask sheet is consistent with distribution of the welding areas around evaporation effective areas101of mask units10which are located in an inner region of the mask sheet. The inner region of the mask sheet here may refer to a region of the mask sheet which is closer to the center of the mask sheet than the edge of the mask sheet. The inner region of the mask sheet may include the center of the mask sheet.

The mask sheet provided by the present disclosure includes a plurality of mask units. The mask sheet provided by the present disclosure may realize wrinkle removal for the evaporation effective areas inside the mask sheet by disposing welding areas around the evaporation effective areas inside mask unit; on the other hand, the mask sheet may optimize the welding areas around the evaporation effective areas at the edge such that the distribution of the welding areas around the evaporation effective areas at the edge of the mask sheet is consistent with the distribution of the welding areas around the evaporation effective areas in the inner region of the mask sheet. In this way, the force applied around the evaporation effective areas at the edge of the mask sheet is consistent with the force applied around the evaporation effective areas in the inner region of the mask sheet. Thus, the wrinkles occurring at the evaporation effective areas at the edge can be improved, which thus improves the wrinkles on the entire FMM Sheet and the flat state of the mask surface. As a consequence, the quality of the evaporated product is improved, which in turn increases the yield of the evaporated product.

Hereinafter, the mask sheet of the present exemplary arrangement will be described in further details.

In the exemplary arrangement, as shown inFIG. 1, the mask sheet may have a plurality of mask units10, and each mask unit10may include an evaporation effective area101and a plurality of welding areas102. The plurality of welding areas102are distributed around the evaporation effective area101according to a preset rule. In addition, the evaporation effective areas101may be arranged in an array and each evaporation effective area101may correspond to a display area on a display substrate. The array for example, may include a plurality of columns or a plurality of rows, or both. Moreover, the plurality of evaporation effective areas101may have consistent or the same shapes and areas, for example, the shapes of the plurality of evaporation effective areas101may be selected from one or more of circle, ellipse and rectangle. In other arrangement, the number, the arrangement, the shapes, and the sizes of the evaporation effective areas are not limited to the examples described above, and arrangements of the present disclosure do not impose specific limitations on this.

In the exemplary arrangement, the mask units10may be arranged in an array and may correspond to the evaporation effective areas101respectively, for example, the array may include a plurality of columns or a plurality of rows, or both. In addition, the mask units10may have consistent or the same shapes and areas, for example, the shape of each mask unit10may be rectangle.

For example, a plurality of evaporation effective areas101arranged in an array may be disposed on the mask sheet, and the evaporation effective areas101may have a circular shape with the same areas. A plurality of mask units10arranged in an array may be disposed, and each of the mask units10may be corresponding to a respect one of the evaporation effective areas. The mask units10may have a rectangle shape with the same areas. As shown inFIGS. 1 and 2, for example, the mask sheet has a mask unit array, the mask unit array includes a plurality of rows, andFIGS. 1 and 2shows one of the rows. A region of a mask unit10may include an evaporation effective area101, welding areas102and a redundant area103.

During manufacture, wrinkles may occur on the evaporation effective area101while the FMM sheet is stretched. In the arrangement, this problem can be addressed by disposing welding areas. As shown inFIG. 1, four welding areas102may be disposed around the evaporation effective area101. In other arrangements, more than four welding areas102may be disposed around the evaporation effective area101.

In the above region of the mask unit10, the welding areas102may be disposed at the four corners of the evaporation effective area101; however, it has been found through practice that disposing of the welding areas102has a significant improvement on the wrinkles that occur on the evaporation effective areas101of the mask units located in the inside of an entire row of the FMM sheet, while has no improvement on the wrinkles that occur on the evaporation effective areas101of the mask units located at the beginning and the end of the row. Even by changing variables such as energy (transition between high energy and low energy), pitch (adjustment of the spacing between two dots and spacing between dots of multiple rows) and the number of dots (adjustment from one row of dots to multiple rows of dots or from multiple rows of dots to one row of dots), the wrinkles that occur on the evaporation effective areas101of the mask units located at the beginning and the end of the row still exist. This affects the flat state of the mask surface and as a result affects the quality of the evaporated product.

There is proposed a method for disposing welding areas, so as to address the wrinkles occurring on evaporation effective areas101of mask units located at the edge of a FMM sheet. The method may have the distribution of the welding areas102around the mask units10at the edge of the FMM sheet be consistent with the distribution of the welding areas102around the mask units10in the inner region of the FMM sheet, and in this way, the force applied around the mask units10at the edge of the FMM sheet is consistent with the force applied around the mask units10in the inner region of the FMM sheet. Further, as shown inFIG. 2, the distribution of the welding areas102around the mask units10at the edge (i.e., at the beginning and the end) of the mask sheet may be consistent with the distribution of the welding areas102around the mask units located in the inner region of the mask sheet.

For example, as shown inFIG. 1, there are eight welding areas102around the mask unit10(as indicated by the dotted box) that are located in the inner region of the mask sheet (i.e., four welding areas around the mask unit10as indicated by the dotted box, and two welding areas that are disposed at the two corners of the left-adjacent mask unit close to the mask unit10and two welding areas that are disposed at the two corners of the right-adjacent mask unit close to the mask unit10). There are six welding areas102around the mask unit10that is located at the edge (i.e., the mask unit10at the beginning or the end of the row), i.e., four welding areas102around the mask unit10at the beginning or the end of the row and two welding areas102that are disposed at the two corners of one adjacent mask unit close to the mask unit10at the beginning or the end of the row.

It is assumed that a virtual mask unit area20is disposed at an outer side of the mask unit that are located at the edge (i.e., the beginning or the end) of the row, and this outer side refers to a side far away from the inner region (e.g., the middle) of this row. As shown inFIG. 2, there are provided with two welding areas202at the two adjacent corners of the mask units10that are located at the beginning and the end of this row in the corresponding virtual mask unit area20, and the number of the welding areas102around the mask unit10at the edge (i.e., at the beginning or the end) is added from six up to eight by addition of these two welding areas202, that is to say, the number of welding areas102around the mask unit10at the edge is same as the number of welding areas102around the mask unit10in the inner region of the mask sheet, i.e.,8welding areas. In addition, the positions of welding areas102around the mask unit10at the edge corresponds to or is the same as the positions of welding areas102around the mask unit10at the inner region of the row. As a result, the force applied around the two mask units10at the beginning and the end of this row is consistent with the force applied around the mask units10at the inner region of this row, which in turn address the wrinkles occurring on the effective areas101of the mask units10at the edge (i.e., at the beginning and the end) of this row and the flat state of the mask surface is improved, thus improving the yield and quality of evaporated product.

In other arrangements, it is possible to optimize arrangement of evaporation effective areas of the mask units10at the edge (i.e., at the beginning or the end of the row or column) in a form of columns or a form of columns and rows, and all designs where the distribution of the welding areas102around the mask units10at the edge is consistent with the distribution of the welding areas102around the mask unit10at the inner region of the mask sheet falls into the scope of the present disclosure.

There is provided a method for manufacturing a mask sheet in arrangements of the present disclosure and this method may include the following.

A plurality of mask units10are formed and each mask unit10includes an evaporation effective area101.

A plurality of welding areas102are formed around the evaporation effective area101according to a preset rule. The distribution of the welding areas102around evaporation effective areas101of mask units10which are located at an edge of the mask sheet is consistent with distribution of the welding areas102around evaporation effective areas101of mask units10which are located in an inner region of the mask sheet.

All specific features regarding the above method have been described in the above arrangements of the mask sheet and thus details will be omitted here.

In addition, although the various blocks of the method of the present disclosure are described in a particular order in the drawings, it is not required or implied that the blocks should be performed in this specific order, or that all the blocks shown should be performed to achieve the desired result. Additionally or alternatively, some blocks may be omitted, or multiple blocks may be combined into one block for execution, and/or one block may be decomposed into multiple blocks for execution.

Other arrangements of the present disclosure will be apparent to those skilled in the art when considering the specification and practicing the disclosure herein. The present application is intended to cover any variations, uses, or adaptations of the present disclosure, which are in accordance with the general principles of the present disclosure and include common knowledge or customary means in the art that are not disclosed in the present disclosure. The specification and examples are intended to be regarded as illustrative only, and the turn scope and spirit are defined by the accompanying claims.