JP2005171290A - Mask for vapor deposition, and method for cleaning the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film of high accuracy by suppressing changes in mask flatness, opening accuracy or the like by deposition of foreign matters contained in cleaning solution even when a mask for vapor deposition is cleaned and recycled. <P>SOLUTION: In a mask 1 for vapor deposition comprising a thin plate-like mask foil 2 having an opening of the shape corresponding to a forming pattern on a work and a frame body 3 to support an area in a vicinity of an outer peripheral edge, a groove part 6 formed with the size according to the size of foreign matters to be removed when cleaning the mask and a through hole 7 to make the groove part 6 communicate with any face other than a supporting face 3a in the frame body 3 are formed in the supporting face 3a of the mask foil 2 in the frame body 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an evaporation mask used for forming a predetermined pattern on an object to be processed and a cleaning method therefor.

  In general, in the manufacturing process of an organic electroluminescent element (organic electroluminescent element; hereinafter referred to as “organic EL element”), the water resistance of the organic material forming the organic layer is low and a wet process cannot be used. An organic layer (thin film) is formed thereon. Further, in the manufacturing process of the organic EL element, in order to perform patterning film formation (for example, film formation corresponding to each color component of R, G, B) on the glass substrate, the shape corresponding to the formation pattern is usually used. An evaporation mask having an opening (passage for organic material) is used.

  Conventionally, as a mask for vapor deposition, a mask foil in which an opening having a shape corresponding to a formation pattern is formed in a pattern region, and a frame body that supports an outer peripheral edge region other than the pattern region of the mask foil are provided. Things are known. The mask foil is made of a thin plate member such as a copper plate, a nickel plate, or a rolled stainless steel plate, and an opening is provided in the pattern region by etching or laser processing. On the other hand, the frame has a sufficient thickness and high rigidity made of a material having a thermal linear expansion coefficient equivalent to that of the glass substrate that is the object to be processed. And the mask for vapor deposition which consists of these mask foil and a frame is fixed to the frame in the state which applied tension to the mask foil so that slack does not arise in the mask foil (for example, patent) Reference 1).

Registered Utility Model No. 3082805

  By the way, when the vapor deposition mask is continuously used, an organic material is deposited along with this, so it is necessary to periodically clean and regenerate it. This is because when the organic material is deposited, the pattern formation of the organic layer cannot be performed with high accuracy. In general, the evaporation mask is cleaned using a dedicated cleaning solution.

  However, when cleaning and reclaiming a vapor deposition mask on which an organic material is deposited, foreign substances (organic material or other floating dust deposited from the deposited portion) contained in the cleaning solution are removed from the mask foil during the cleaning of the mask. And the support surface of the mask foil in the frame. This is because the vapor deposition mask applies tension to the mask foil and requires high positional accuracy as described above, and therefore, only the region near the outer peripheral edge of the mask foil is often fixed to the frame. That is, since only the area near the outer peripheral edge of the mask foil is fixed to the frame, it is conceivable that foreign matter enters from the non-fixed side portion and stays between the mask foil and the support surface as it is. The retention of such foreign substances causes a change in the flatness and opening accuracy of the mask foil because the mask foil is made of an extremely thin plate member having a thickness of about several tens of μm, and the deposited film (organic layer) This may be a factor that impairs the uniformity and the forming position accuracy.

  Therefore, the present invention provides a deposition mask and a cleaning method for the deposition mask that can prevent the stay of foreign matters contained in the cleaning liquid and realize highly accurate film formation even when the deposition mask is cleaned and regenerated. It aims to provide a method.

  The present invention is a deposition mask devised to achieve the above object, a thin plate-shaped mask foil having an opening corresponding to a pattern formed on an object to be processed, and a region near the outer peripheral edge of the mask foil And a frame formed on the support surface of the mask foil in the frame with a size corresponding to the foreign matter to be removed during mask cleaning, and the groove and the frame. And a through-hole communicating with a surface of the body other than the support surface.

  Further, the present invention provides a method for cleaning a vapor deposition mask devised to achieve the above object, and a thin plate-like mask foil having an opening having a shape corresponding to a formation pattern on an object to be processed, and the mask foil A vapor deposition mask cleaning method comprising a frame supporting a region near the outer peripheral edge of the mask, wherein a groove having a size corresponding to a foreign matter to be removed during mask cleaning is formed on the support surface of the mask foil in the frame. And forming a through hole that communicates the groove and a surface other than the support surface of the frame, and after performing mask cleaning on the evaporation mask using a cleaning liquid, the cleaning liquid The foreign matter contained in is removed from between the mask foil and the support surface through the groove and the through hole.

  According to the above-described vapor deposition mask and the above method of cleaning the vapor deposition mask, a groove is formed on the support surface of the mask foil in the frame, and the groove and a surface other than the support surface in the frame are formed. Since the through-hole to be communicated is formed, even if a foreign substance enters between the mask foil and the frame during the mask cleaning, the foreign substance is guided on the groove portion along the flow of the cleaning liquid. That is, it is possible to prevent foreign matter from staying between the mask foil and the frame. This is very effective particularly when the groove is formed in the vicinity of the fixing region along the fixing region of the mask foil on the support surface.

  In the vapor deposition mask and cleaning method of the present invention, it is possible to prevent foreign matter from entering and staying between the mask foil and the frame during mask cleaning. Even so, it is possible to prevent changes in the flatness, opening accuracy, etc. of the mask foil. Therefore, even when the deposition mask is cleaned and regenerated, there is no deterioration in film uniformity and formation position accuracy due to the retention of foreign matter, and high-accuracy film formation can be realized.

  Hereinafter, a deposition mask and a cleaning method thereof according to the present invention will be described with reference to the drawings. 1 and 2 are explanatory views showing an example of a schematic configuration of a vapor deposition mask according to the present invention.

  As shown in FIG. 1A, the vapor deposition mask 1 described here includes a mask foil 2 and a frame 3.

  The mask foil 2 is made of a very thin plate-like member having a thickness of about several tens of μm, such as a copper plate, a nickel plate, a rolled stainless steel plate, etc., and the area on the plane is a pattern area 2a and the other supported area 2b. It is divided roughly into. An opening 4 having a shape corresponding to the formation pattern is formed in the pattern region 2a by etching, laser processing, or the like. The pattern region 2a is not limited to a rectangular shape, and may be various arbitrary shapes. Further, the mask foil 2 may be formed of a thin metal film such as nickel provided with a large number of fine openings 4 in the pattern region 2a by the “electroforming (plating) manufacturing method”.

  On the other hand, the frame 3 is formed in a shape corresponding to the supported region 2b of the mask foil 2, and is for supporting the supported region 2b of the mask foil 2. Here, the frame 3 has a linear thermal expansion coefficient, a heat capacity, a surface radiation emission rate, a heat transfer amount flowing in and out by the surrounding support and heat conduction, etc., and a glass substrate as a processing object and a temperature change during deposition. In order to synchronize and match the dimensional change in expansion and contraction due to the above, it is assumed that the optimal adjustment is set.

  Then, on one plane of the frame 3 (hereinafter, this surface is referred to as a “support surface”), a supported region 2 b in the mask foil 2 is fixed over the entire circumference in a state where tension is applied to the mask foil 2. Yes. As a result, the mask foil 2 fixed with tension is expanded and contracted in accordance with the fixed frame 3. Therefore, as a result, the mask foil 2 can expand and contract in synchronization with the glass substrate that is the object to be processed in synchronization with the dimensional change of expansion and contraction. In addition, it is desirable that the tension and the direction of the tension applied to the mask foil 2 are set so that the stress distribution generated in the pattern region 2a of the mask foil 2 becomes uniform. Further, the mask foil 2 is fixed to the frame 3 with an adhesive having stable properties against temperature changes such as welding such as spot welding or laser welding, or a heat-resistant ceramic adhesive or a heat-resistant epoxy resin adhesive. Although it can be considered to be performed by using the adhesive used, it may be performed by using fasteners (screws) such as screws.

  The vapor deposition mask 1 having such a configuration is used with a glass substrate 5 placed on a mask foil 2 as shown in FIG. At this time, since the mask foil 2 is made of a thin plate member and cannot be said to have high strength, the glass substrate 5 has an edge portion that is a part of the frame 3 (hereinafter, this portion is referred to as “support of the glass substrate”). It is placed so as to overlap 3b). And the organic material from the vapor deposition source (however, not shown) in the frame 3 side passes through the opening 4 in the pattern area | region 2a of the mask foil 2, The glass substrate 5 has a pattern specified by the opening 4 A shaped organic layer is formed.

  By the way, since the mask foil 2 is required to have flatness in the support region 3b portion, and is applied with tension when being fixed to the frame 3, and requires positional accuracy, only the region near the outer periphery is the frame. 3 is a fixing region 3c that is fixed to 3. In other words, the fixing region 3c on the outer peripheral side of the support surface 3a in the frame 3 is fixed by welding, adhesion, fasteners, or the like, but the fixing is not performed on the support region 3b on the inner peripheral side of the support surface 3a. Therefore, when cleaning the vapor deposition mask 1, foreign substances (organic material deposited from the deposition location, other floating dust, etc.) contained in the cleaning liquid are removed from the support region 3b side, which is a non-adhered location, from the mask foil 2 and the support surface. There is a possibility of entering between 3a.

  From this, in the vapor deposition mask 1 described here, as shown in FIG. 2, the groove 6 is formed on the support surface 3a of the frame 3, and the groove 6 and the support 3a of the frame 3 are formed. A through hole 7 is provided for communicating with other surfaces.

  The groove 6 is formed in a size corresponding to the foreign matter to be removed during mask cleaning. For example, if the foreign matter to be removed has a size of about 0.1 to 100 μm, the groove portion 6 has a size of about 0.5 to several millimeters (groove width and depth) so that the foreign matter can be reliably captured. )). In addition, the cross-sectional shape of the groove part 6 is not specifically limited, Any of a square groove, a V-shaped groove, a U-shaped groove, a round groove, etc. may be sufficient.

  Moreover, the groove part 6 shall be formed avoiding the adhering area | region 3c and the support area | region 3b in the support surface 3a. This is because the groove 6 cannot be provided in the fixing region 3c to fix the mask foil 2, and flatness is required to support the glass substrate 5 in the support region 3b. It is desirable that the groove 6 is formed as close as possible to the fixing region 3c, or as close as possible to the fixing region 3c within a range in which groove processing is possible or a fixing margin is added.

  Further, in consideration of erecting the vapor deposition mask 1 at the time of mask cleaning, the groove 6 is formed at least on one side positioned at the lower side during the upright. However, it may be formed at least on the one side, and may be formed on two opposite sides as shown in the figure, or may be formed on the entire circumference of the frame 3.

  On the other hand, it is conceivable that the through holes 7 are arranged with round holes having a diameter of, for example, several millimeters at a constant pitch because of easy processing. However, the through-hole 7 is not particularly limited as long as it allows the groove 6 and the surface other than the support surface 3a of the frame 3 to communicate with each other. Therefore, in addition to the communication between the groove 6 and the opposite surface of the support surface 3a as shown in the figure, the groove 6 and the adjacent surface of the support surface 3a may be connected.

  Next, a method for cleaning the vapor deposition mask 1 configured as described above will be described. The deposition mask 1 is cleaned using a dedicated cleaning solution. Specifically, by immersing the evaporation mask 1 in the cleaning liquid in the treatment tank of the cleaning apparatus, foreign materials such as organic materials deposited on the evaporation mask 1 and other floating dust adhering to the evaporation mask 1 are removed. Separated from the vapor deposition mask 1. Then, after the foreign matter is separated, the cleaning liquid is dried, and cleaning regeneration for the deposition mask 1 is completed.

  In such a cleaning process, as described above, foreign substances contained in the cleaning liquid may enter between the mask foil 2 and the support surface 3a of the frame 3. However, a groove 6 is formed on the support surface 3 a, and the groove 6 communicates with a surface other than the support surface 3 a through the through hole 7. Therefore, even if a cleaning liquid containing foreign matter flows between the mask foil 2 and the support surface 3a, the cleaning liquid is discharged from the through-hole 7, and accordingly, the foreign matter contained in the cleaning liquid is also removed from the mask foil 2. It flows out in the groove part 6 without staying between the support surfaces 3a.

  As described above, according to the vapor deposition mask 1 and the cleaning method thereof described in the present embodiment, the groove portion 6 is formed on the support surface 3a of the frame 3, and the surfaces other than the groove portion 6 and the support surface 3a. Is formed, and even if foreign matter enters between the mask foil 2 and the frame 3 during mask cleaning, the foreign matter is guided in the flow of the cleaning liquid and guided to the groove 6, and the mask foil 2. And foreign matter can be prevented from staying between the frame 3 and the frame 3. That is, since foreign matter can be prevented from staying, even if the mask foil 2 is made of a very thin plate-like member, a change occurs in the flatness and opening accuracy of the mask foil 2 due to the stay of foreign matter. Can be prevented. Therefore, even when the deposition mask 1 is cleaned and regenerated, there is no deterioration in film uniformity or formation position accuracy due to the retention of foreign matters, and high-accuracy film formation can be realized. In addition, the retention of foreign matter between the mask foil 2 and the frame 3 can be suppressed, so that it is possible to avoid the deterioration of the drying property of the cleaning liquid due to the foreign matter, and as a result, the mask cleaning process can be speeded up. It becomes like this.

  In particular, if the groove 6 is formed so as to avoid the fixing region 3c and the support region 3b on the support surface 3a, it is very suitable for realizing highly accurate film formation by the vapor deposition mask 1. If the groove 6 avoids the fixing region 3c, it is possible to secure a sufficient area as the fixing region 3c, so that even if tension is applied to the mask foil 2, the fixing to the frame 3 is ensured. This is because the mask foil 2 can be expanded and contracted in synchronism with the glass substrate 5. Further, if the groove 6 avoids the support region 3b, the flatness of the support region 3b can be sufficiently ensured, so that the placement when the glass substrate 5 is placed on the vapor deposition mask 1 is carried out. This is because the accuracy can be maintained high. If the groove 6 is adjacent to the fixing region 3c or is formed as close as possible to the fixing region 3c, the mask foil 2 and the support surface 3a of the frame 3 are provided in the outer peripheral region of the groove 6. There is no gap between them and no foreign matter enters between them. Therefore, foreign matter staying between the mask foil 2 and the frame 3 can be effectively suppressed, so that it can be expected that realization of highly accurate film formation will be ensured.

  Moreover, since the groove | channel part 6 makes the vapor deposition mask 1 stand upright at the time of mask cleaning, it should just be formed in the one side located below at least at the time of the upright, but if it is formed in two opposing sides, it will be for vapor deposition Since the top-and-bottom direction when raising the mask 1 is arbitrary, the mask cleaning process can be facilitated and speeded up. Furthermore, if it is formed over the entire circumference of the frame 3, the cleaning liquid containing foreign matter is more likely to flow into the groove 6, which is very suitable for realizing highly accurate film formation by the vapor deposition mask 1. It will be something.

  Although the present embodiment has been described with reference to a suitable specific example for carrying out the present invention, the present invention is not limited to this and can be variously modified. That is, the material, shape, and the like of a series of constituent elements constituting the vapor deposition mask 1 described in the present embodiment are not necessarily limited to those described in the present embodiment, and the functions of the respective constituent elements are similarly secured. You can change it as much as you can.

  Moreover, in this embodiment, what was used by the manufacturing process of an organic EL element was mentioned as an example of the mask 1 for vapor deposition, but this invention is not limited to this, Other film-forming processes (For example, Needless to say, the mask used in the sputtering process can be applied in exactly the same manner.

It is explanatory drawing (the 1) which shows an example of schematic structure of the vapor deposition mask which concerns on this invention, (a) is the perspective view, (b) is the side view. It is explanatory drawing (the 2) which shows an example of schematic structure of the vapor deposition mask which concerns on this invention, (a) is the top view, (b) is the sectional side view.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Evaporation mask, 2 ... Mask foil, 2a ... Pattern area | region, 2b ... Supported area, 3 ... Frame, 3a ... Support surface, 3b ... Support area, 3c ... Adhesion area, 4 ... Opening, 5 ... Glass substrate , 6 ... groove, 7 ... through hole

Claims (3)

In a mask for vapor deposition comprising a thin plate-like mask foil having an opening having a shape corresponding to a pattern to be processed, and a frame supporting a region near the outer periphery of the mask foil,
On the support surface of the mask foil in the frame body, a groove formed in a size according to the foreign matter to be removed during mask cleaning,
A vapor deposition mask comprising: the groove portion and a through hole that allows the frame body to communicate with a surface other than the support surface. The vapor deposition mask according to claim 1, wherein the groove is formed so as to avoid a fixing region of the mask foil and a support region of the object to be processed on the support surface. A method for cleaning a deposition mask comprising: a thin plate-like mask foil having an opening having a shape corresponding to a formation pattern on an object to be processed; and a frame for supporting a region near the outer peripheral edge of the mask foil,
A groove having a size corresponding to the foreign matter to be removed at the time of mask cleaning is formed on the support surface of the mask foil in the frame, and the groove and the surface other than the support surface in the frame communicate with each other. Forming a hole,
After performing mask cleaning on the vapor deposition mask using a cleaning liquid, foreign substances contained in the cleaning liquid are removed from between the mask foil and the support surface through the groove and the through hole. Cleaning method for evaporation mask.

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