JP7421617B2 - vapor deposition mask - Google Patents

Description

The present invention relates to a vapor deposition mask. INDUSTRIAL APPLICATION This invention is applicable to the vapor deposition mask for organic EL elements used when forming the light emitting layer of an organic EL element, for example by the vapor deposition mask method.

Patent Document 1 discloses a vapor deposition mask in which a frame 103 for reinforcing the mask body 102 is attached to the outer peripheral edge of the mask body 102, as shown in FIG. The frame 103 therein is made of a material having a thermal linear expansion coefficient equivalent to that of the deposition target substrate 30 or a material having a low thermal linear expansion coefficient. The frame 103 is fixed onto the mask body 102 via an adhesive 108 made of an adhesive that is stable against temperature changes, such as a heat-resistant ceramic adhesive or a heat-resistant epoxy resin adhesive. The mask main body 102 includes a vapor deposition pattern 106 for forming a light emitting layer 310 of an organic EL element, which is composed of a large number of independent vapor deposition holes 105, in a pattern forming region 104. According to the vapor deposition mask disclosed in Patent Document 1, even if the material forming the mask body 102 has a coefficient of linear thermal expansion that is different from that of the substrate 30 to be evaporated, the mask body 102 has a coefficient of linear thermal expansion equivalent to that of the substrate 30 to be evaporated. The shape changes following the expansion of the frame 103, or the shape does not change due to being suppressed by the frame 103 having a low coefficient of linear thermal expansion. Therefore, the alignment accuracy of the mask body 102 with respect to the substrate 30 to be evaporated at room temperature is improved. Since this can be ensured well even when the temperature is raised in the oven, there is an advantage that the light-emitting layer 310 can be formed on the substrate 30 to be vapor-deposited with high precision and good reproducibility.

Japanese Patent Application Publication No. 2002-371349

The evaporation mask method is a method in which a evaporation mask is placed on a substrate to be evaporated, and an organic material vaporized by a vaporization source is evaporated into the evaporation holes of the evaporation mask to form a light-emitting layer on the substrate to be evaporated. The light-emitting layer formed on the substrate to be vapor-deposited is required to have a uniform height dimension. However, if the evaporation holes 105 are straight like the evaporation mask shown in FIG. The organic material entering the evaporation hole 105 from this direction is blocked by the upper edge of the opening of the mask, and only a small amount of the organic material is deposited on the substrate 30 at the edge of the evaporation hole 105, resulting in complete light emission. The layer 310 tends to have a substantially water droplet-like shape when viewed in cross section with a swollen central portion and a gradually decreasing edge portion. The light emitting layer 310 having such a distorted shape has uneven brightness, which is a major obstacle in achieving high precision of the device.

An object of the present invention is to provide a vapor deposition mask that can form a light emitting layer having a uniform height dimension with high precision and good reproducibility.

In the vapor deposition mask 1 according to the present invention, the mask body 2 is provided with a vapor deposition pattern 6 consisting of a large number of independent vapor deposition holes 5 . The vapor deposition through hole 5 has a small hole 5a located on the vaporization source side and a large hole 5b located on the deposition target substrate 30 side and formed larger than the opening shape of the small hole 5a. It is characterized by being

The mask body 2 also includes first metal layers 13 and 44 and second metal layers 16 and 45, and the second metal layers 16 and 45 cover the top and side surfaces of the first metal layers 13 and 44, respectively. The cross-sectional shape of the mask body 2 between the vapor deposition holes 5 is stepped.

Further, the upper end peripheral edge portions of the second metal layers 16 and 45 facing the circumferential surfaces of the large hole portion 5b and the small hole portion 5a are rounded.

Further, a vapor deposition pattern 6 is formed in the pattern forming area 4 , a frame 3 made of a material with a low coefficient of linear thermal expansion is arranged around the outer periphery of the mask main body 2 , and the outer periphery of the pattern forming area 4 of the mask main body 2 is arranged. 4a and the frame 3 are integrally joined via a metal layer 9.

The present invention also provides a method for manufacturing a vapor deposition mask in which a vapor deposition pattern 6 consisting of a large number of independent vapor deposition holes 5 is provided on a mask body 2, and a primary pattern resist having a resist body 12a is formed on the surface of a matrix 10. forming a first metal layer 13 on the mother mold 10 using the primary pattern resist 12; and forming a secondary pattern resist 15 having a resist body 15a on the surface of the mother mold 10. forming a second metal layer 16 on the matrix 10 and the first metal layer 13 using the secondary pattern resist 15; It is characterized by including the step of integrally peeling off.

Furthermore, the present invention provides a method for manufacturing a vapor deposition mask in which a mask body 2 is provided with a vapor deposition pattern 6 consisting of a large number of independent vapor deposition holes 5, which includes a step of preparing a matrix 40 on which a pattern of a metal film 41 is formed. a step of forming a patterned resist 43 having a resist body 43a on the surface of the matrix 40; a step of forming a first metal layer 44 on the metal film 41 using the pattern resist 43; It is characterized by including a step of forming a second metal layer 45 on the first metal layer 44 and a step of peeling the first metal layer 44 and the second metal layer 45 together from the matrix 10.

According to the vapor deposition mask according to the present invention, the vapor deposition through holes 5 provided in the mask body 2 include the small hole portion 5a located on the vaporization source side and the opening of the small hole portion 5a located on the vapor deposition target substrate 30 side. Since the large hole portion 5b, which is formed larger than the shape, is formed in communication, the vapor deposition through hole 5 has a shape that expands outward toward the vaporization source, and can receive the organic material from the vaporization source at a wide angle. Therefore, it is possible to eliminate the shadow caused by the upper edge of the opening, which occurs because the vapor deposition through hole is straight, and to form a light emitting layer having a uniform height dimension with high precision.

Moreover, according to the method for manufacturing a vapor deposition mask according to the present invention, the mask body 2 has the first metal layers 13 and 44 and the second metal layers 16 and 45, and the surface of the first metal layers 13 and 44 Since the second metal layers 16, 45 are formed so as to cover the first metal layers 13, 44 and the second metal layers 16, 45, the adhesion between the first metal layers 13, 44 and the second metal layers 16, 45 is good, and a high-precision vapor deposition mask can be manufactured with high productivity. Can be manufactured well.

A vertical side view of a vapor deposition mask according to a first embodiment of the present invention An exploded perspective view of a vapor deposition mask according to a first embodiment of the present invention Process explanatory diagram of the manufacturing process of the vapor deposition mask according to the first embodiment of the present invention Process explanatory diagram of the manufacturing process of the vapor deposition mask according to the first embodiment of the present invention Process explanatory diagram of the manufacturing process of the vapor deposition mask according to the first embodiment of the present invention A longitudinal side view of a vapor deposition mask according to a second embodiment of the present invention A plan view of essential parts of a vapor deposition mask according to a second embodiment of the present invention A perspective view of main parts of a vapor deposition mask according to a second embodiment of the present invention Exploded perspective view of a vapor deposition mask according to a second embodiment of the present invention Process explanatory diagram of the manufacturing process of a vapor deposition mask according to the second embodiment of the present invention Process explanatory diagram of the manufacturing process of a vapor deposition mask according to the second embodiment of the present invention Process explanatory diagram of the manufacturing process of a vapor deposition mask according to the second embodiment of the present invention Process explanatory diagram of the manufacturing process of a vapor deposition mask according to the third embodiment of the present invention Process explanatory diagram of the manufacturing process of a vapor deposition mask according to the third embodiment of the present invention Vertical side view of a vapor deposition mask according to a third embodiment of the present invention Vertical side view of a vapor deposition mask according to another embodiment of the present invention Vertical cross-sectional view showing a conventional vapor deposition mask

(First embodiment)
In FIG. 1, a vapor deposition mask 1 has a mask body 2 provided with a vapor deposition pattern 6 consisting of a large number of independent vapor deposition holes 5. The mask body 2 is formed by electroforming using nickel, a nickel alloy such as nickel-cobalt, copper, or other electrodeposited metal. In FIG. 2, the mask body 2 is formed into, for example, four independent squares of 50 x 50 mm in a square matrix area of 200 x 200 mm, and has a pattern forming area 4 therein. . A vapor deposition pattern 6 consisting of vapor deposition holes 5 is formed in this pattern forming area 4 .

The mask body 2 has a first metal layer 13 and a second metal layer 16. Specifically, the second metal layer 16 is formed to cover the top and side surfaces of the first metal layer 13. In this embodiment, the top surface refers to the vaporization source side, and the side surface refers to the surface facing the vapor deposition through hole 5. In this way, by forming the second metal layer 16 to cover the surface of the first metal layer 13, the first metal layer 16 is formed to cover the surface of the first metal layer 13. Since the contact surface area between the layer 13 and the second metal layer 16 is increased, a laminated structure in which the first metal layer 13 and the second metal layer 16 are firmly adhered can be obtained. The thickness of the mask body 2 is preferably in the range of 10 to 100 μm, and was set to 20 μm in this example. Specifically, the thickness t1 of the first metal layer 13 is preferably in the range of 5 to 90 μm, and is set to 16 μm in this embodiment, and the thickness t2 of the second metal layer 16 is preferably 10 μm or less, and In the example, the thickness was set to 4 μm. Note that the thinner the thickness t2 of the second metal layer 16 is, the more shadows caused by the upper edge of the vapor deposition through hole 5 can be eliminated.

Each vapor deposition through hole 5 is formed by communicating a small hole 5a with a large hole 5b formed larger than the opening shape of the small hole 5a. For example, the small hole 5a has a flat surface. It has a rectangular shape with a front and rear length of 150 μm and a left and right width of 50 μm when viewed in plan, and the large hole 5b has a square shape with a front and rear length of 300 μm and a left and right width of 150 μm when viewed from above. have. The small hole portion 5a is on the side of the substrate to be deposited 30, and the large hole portion 5b is on the side of the vaporization source. These vapor deposition holes 5 are arranged in parallel in the front-rear and/or left-right direction to form a vapor deposition pattern 6. As shown in FIG. 1, the mask main body 2 (first metal layer 13 and second metal layer 16) between the vapor deposition holes 5 is formed in a stepped shape in cross-sectional view, so that the vapor deposition holes 5 are small. The configuration is composed of a hole 5a and a large hole 5b. This large hole 5b makes it possible to receive the organic material from the vaporization source at a wide angle, and it is also possible to accommodate the organic material incident from an oblique direction, so it is possible to form a light emitting layer with uniform height dimensions. I can contribute. Moreover, as shown in FIG. 1, by making the upper end peripheral edge part (the vaporization source side peripheral part) of the second metal layer 16 facing the peripheral surfaces of the large hole part 5b and the small hole part 5a rounded, Shadows caused by the upper edges of the holes 5b and small holes 5a can be completely eliminated, the acceptance angle of the organic material can be further widened, and a light-emitting layer with a more uniform height can be obtained. Note that the vertical cross-sectional view in FIG. 1 does not show the actual state of the vapor deposition pattern 6, but only schematically shows it.

A frame 3 for reinforcing the mask body 2 can be attached to the mask body 2. The frame 3 is made of a material with a low linear thermal expansion coefficient, such as Invar material, which is a nickel-iron alloy, or Super Invar material, which is a nickel-iron-cobalt alloy. The frame body 3 is a molded product that is thicker than the mask body 2, and is integrally and inseparably joined to the outer peripheral edge 4a of the pattern forming area 4 of the mask body 2 by the metal layer 9. Here, as shown in FIG. 2, four mask bodies 2 are held by one frame 3. That is, the frame body 3 has four openings 3a arranged in alignment on its plate surface, and one mask body 2 is attached to each opening 3a. The frame body 3 has an opening 3a corresponding to the mask body 2, and is formed into a flat plate shape. The thickness of the frame 3 is, for example, about 100 to 500 μm, and in this example, it is set to 200 μm.

The reason why Invar material or Super Invar material was adopted as the material for forming the frame 3 is that its coefficient of linear expansion is extremely small at 2×10 ^-6 /℃ or less than 1×10 ^-6 /℃, which prevents thermal effects during the vapor deposition process. This is because dimensional changes in the mask body 2 caused by the above can be suppressed well. That is, for example, if the mask body 2 is made of nickel as described above, its linear expansion coefficient is 12.80×10 ^-6 /°C, and the general glass which is the deposition substrate 30 (see FIG. 17) The coefficient ^of linear expansion of It is inevitable that a positional shift occurs between the vapor deposition position and the vapor deposition position of the vapor deposition substance during actual vapor deposition. Therefore, if a material with a small coefficient of linear expansion, such as Invar material, is used as the material for forming the frame 3 that holds the mask body 2, dimensional changes and shape changes due to the expansion of the mask body 2 when the temperature rises. The alignment accuracy at room temperature can be well maintained even when the temperature is increased during vapor deposition.

In FIG. 1, reference numeral 9 indicates a metal layer laminated on the upper surface of the mask body 2 related to the outer peripheral edge 4a of the pattern forming area. Specifically, the metal layer 9 is formed on the upper surface of the outer peripheral edge 4a of the pattern forming region 4, on the upper surface of the frame 3 and the side surface facing the pattern forming region 4, and in the gap between the mask body 2 and the frame 3. With this, the outer periphery 4a of the pattern forming area 4 and the opening periphery of the frame 3 are integrally and inseparably joined. This metal layer 9 is made of nickel, nickel-cobalt alloy, or the like, and can be formed by a plating method.

3 to 5 show a method for manufacturing a vapor deposition mask according to this embodiment. First, as shown in FIG. 3(a), a photoresist layer 11 is formed on the surface of the master mold 10. The mother mold 10 is made of conductive material such as stainless steel or brass steel, for example. The photoresist layer 11 is formed by laminating one or several negative-type photosensitive dry film resists to a predetermined height and bonding them under heat.

Next, on the photoresist layer 11, a pattern film (glass mask) having transparent holes corresponding to the positions of the large holes 5b of the vapor deposition holes 5 is closely attached, and then exposed to ultraviolet light. By performing development and drying processes and removing the unexposed portions, a straight resist body 12a corresponding to the position of the large hole 5b of the vapor deposition through hole 5 is obtained, as shown in FIG. 3(b). A primary pattern resist 12 was formed on the master die 10.

Next, the mother mold 10 is placed in an electroforming bath prepared under predetermined conditions, and as shown in FIG. A first metal layer 13 was formed on the uncovered surface (exposed area) by electroforming a nickel-cobalt alloy, preferably in the range of 5 to 90 μm thick, in this embodiment 16 μm thick. After forming the first metal layer 13, the primary pattern resist 12 (resist body 12a) is removed, as shown in FIG. 3(d).

Subsequently, as shown in FIG. 4(a), a photoresist layer 14 was formed on the entire surface of the master mold 10 including the region where the first metal layer 13 was to be formed. This photoresist layer 14 is formed by laminating one or several negative-type photosensitive dry film resists to a predetermined height and bonding them by thermocompression.

Next, a patterned film having light-transmitting holes corresponding to the positions of the small holes 5a of the vapor deposition holes 5 is closely attached, and then exposed to ultraviolet light, developed, and dried. By removing the portion, a secondary pattern resist 15 having a straight resist body 15a corresponding to the position of the small hole portion 5a of the vapor deposition through hole 5 was formed on the matrix 10, as shown in FIG. 4(b). .

Next, the mother mold 10 is placed in an electroforming bath prepared under predetermined conditions, and as shown in FIG. A second metal layer 16 was formed by electroforming a nickel-cobalt alloy onto the surface (exposed region) not covered with the resist body 16a of No. 13 to a thickness of preferably 10 μm or less, in this embodiment, 4 μm. . At this time, the second metal layer 16 formed in the portion facing the end (top or root) of the first metal layer 13 has an R shape. Further, the end portion of the second metal layer 16 facing the vapor deposition through hole 5 also has a rounded shape. Note that the desired curvature of R can be obtained by adjusting the thickness of the second metal layer 16. Then, by removing the secondary pattern resist 15 (resist body 15a), a mask body 2 having a vapor deposition pattern 6 consisting of a large number of independent vapor deposition holes 5 was obtained, as shown in FIG. 4(d).

Subsequently, as shown in FIG. 5(a), a photoresist layer 17 was formed on the entire surface of the master mold 10, including the portion where the first metal layer 13 and the second metal layer 16 (mask body 2) were to be formed. This photoresist layer 17 is formed by laminating one or several negative-type photosensitive dry film resists to a predetermined height and bonding them under heat. Next, a patterned film having transparent holes corresponding to the pattern forming area 4 was brought into close contact with the film, and then exposed to ultraviolet light. In this way, a photoresist layer 17 is obtained in which the portion corresponding to the pattern forming area 4 is exposed (17a) and the other portion is unexposed (17b), and then a matrix is formed as shown in FIG. 5(b). The frame body 3 was arranged on the metal layer 10 so as to surround the first metal layer 13 and the second metal layer 16. Here, the frame 3 was temporarily fixed onto the matrix 10 by utilizing the adhesiveness of the unexposed photoresist layer 17b.

Next, as shown in FIG. 5C, the unexposed photoresist layer 17b exposed on the surface was dissolved and removed to form a tertiary pattern resist 18 having a resist body 18a covering the pattern forming area 4. Note that at this time, the unexposed photoresist layer 17b existing on the lower surface of the frame 3 remains on the matrix 10.

Next, as shown in FIG. 5(d), the upper surface of the second metal layer 16 exposed on the surface of the outer peripheral edge 4a of the pattern forming area 4, and the matrix exposed between the frame 3 and the second metal layer 16. A metal layer 9 is formed by electroforming an electrodeposited metal on the surface of 10 and the surface of the frame 3, and this metal layer 9 forms a bond between the second metal layer 16 including the first metal layer 13 and the frame 3. were joined. At this time, the upper surface of the second metal layer 16 exposed on the surface of the outer peripheral edge 4a of the pattern forming area 4, and the metal layer 9 on the surface of the matrix 10 exposed between the frame 3 and the second metal layer 16. The layer thickness of the metal layer 9 on the surface of the frame body 3 was 15 μm. The reason why the layer thickness is different between the surface of the matrix 10 and the frame 3 is that the metal layer 9 is sequentially laminated from the surface of the matrix 10, and the metal layer 9 is unexposed. When the height of the photoresist layer 17b is exceeded to reach the frame 3, the frame 3 becomes electrically conductive with the matrix 10, and the metal layer 9 is formed on the surface of the frame 3.

Finally, after peeling off the first metal layer 13, second metal layer 16, and metal layer 9 from the matrix 10, the tertiary pattern resist 18 and the unexposed photoresist layer 17b on the lower surface of the frame 3 are removed. By doing so, a mask 1 as shown in FIG. 1 was obtained.

(Second embodiment)
A vapor deposition mask according to a second embodiment of the present invention will be described based on FIGS. 6 to 12. In FIG. 6, a vapor deposition mask 1 includes a mask body 2 provided with a vapor deposition pattern 6 consisting of a large number of independent vapor deposition holes 5. It is formed by electroforming using electrodeposited metal as a material. In FIG. 9, a vapor deposition mask 1 has a rectangular shape of 500 mm x 400 mm, and has a plurality of mask bodies 2 inside thereof. Each mask body 2 is formed in a rectangular shape of 50×40 mm, and has a pattern forming area 4 inside thereof. In the pattern forming region 4, a vapor deposition pattern 6 for forming a light emitting layer is formed, which is composed of a large number of independent vapor deposition holes 5.

The mask body 2 has a first metal layer 13 and a second metal layer 16. Specifically, as shown in FIG. 6, the second metal layer 16 is formed to cover the upper surface and side surfaces of the first metal layer 13, and the first metal layer 13 and the second metal layer between the vapor deposition through holes 5. 16 (mask body 2) has a stepped cross-sectional shape. In this way, by forming the second metal layer 16 to cover the surface of the first metal layer 13, the first metal layer 16 is formed to cover the surface of the first metal layer 13. Since the contact surface area between the layer 13 and the second metal layer 16 is increased, a laminated structure in which the first metal layer 13 and the second metal layer 16 are firmly adhered can be obtained. The thickness of the mask body 2 is preferably in the range of 10 to 100 μm, and was set to 20 μm in this example. Specifically, the thickness t1 of the first metal layer 13 is preferably in the range of 5 to 90 μm, and is set to 16 μm in this embodiment, and the thickness t2 of the second metal layer 16 is preferably 10 μm or less, and In the example, the thickness was set to 4 μm. Note that the upper surface of the first metal layer 13 points to the vaporization source side, and the side surface of the first metal layer 13 points to the surface facing the vapor deposition through hole 5.

Each vapor deposition through hole 5 is formed by communicating a small hole 5a with a large hole 5b formed larger than the opening shape of the small hole 5a. For example, the small hole 5a has a flat surface. It has a rectangular shape with a front and rear length of 150 m and a left and right width of 50 μm when viewed in plan, and the large hole 5b has a square shape with a front and rear length of 300 μm and a left and right width of 150 μm when viewed from above. have. The small hole portion 5a is on the side of the substrate to be deposited 30, and the large hole portion 5b is on the side of the vaporization source. These vapor deposition holes 5 are arranged in parallel in the front-back or left-right direction to form a vapor deposition pattern 6. In this way, the first metal layer 13 and the second metal layer 16 are formed in a stepped shape in a cross-sectional view, so that the vapor deposition through hole 5 has a form composed of a small hole portion 5a and a large hole portion 5b. This large hole 5b makes it possible to receive the organic material from the vaporization source at a wide angle, and it is also possible to receive the organic material that is incident from an oblique direction. You can contribute to the formation. Moreover, by making each upper end peripheral edge part (vaporization source side peripheral part) of the second metal layer 16 facing the circumferential surfaces of the large hole part 5b and the small hole part 5a into an R shape, the large hole part 5b and the small hole part 5a It is possible to eliminate the shadow caused by the upper end periphery as much as possible, widen the acceptance angle of the organic material, and obtain a light-emitting layer with a more uniform height dimension. Note that the vertical cross-sectional view in FIG. 1 does not show the actual state of the vapor deposition pattern 6, but only schematically shows it.

A frame 3 for reinforcing the mask body 2 can be attached to the mask body 2. The frame 3 is made of a material with a low linear thermal expansion coefficient, such as Invar material, which is a nickel-iron alloy, or Super Invar material, which is a nickel-iron-cobalt alloy. The frame body 3 is a molded product that is thicker than the mask body 2, and is integrally and inseparably joined to the outer peripheral edge 4a of the pattern forming area 4 of the mask body 2 by the metal layer 9. Here, as shown in FIG. 9, 30 mask bodies 2 are held by one frame 3. That is, the frame 3 has 30 openings 3a arranged in a row on its plate surface, and one mask body 2 is attached to each opening 3a. The frame body 3 has an opening 3a corresponding to the mask body 2, and is formed into a flat plate shape. The thickness of the frame 3 is, for example, about 100 to 500 μm, and in this example, it is set to 250 μm.

The reason why Invar material or Super Invar material was adopted as the material for forming the frame 3 is that its coefficient of linear expansion is extremely small at 2×10 ^-6 /℃ or less than 1×10 ^-6 /℃, which prevents thermal effects during the vapor deposition process. This is because dimensional changes in the mask body 2 caused by the above can be suppressed well. That is, for example, if the mask body 2 is made of nickel as described above, its linear expansion coefficient is 12.80×10 ^-6 /°C, and the general glass which is the deposition substrate 30 (see FIG. 17) The coefficient ^of linear expansion of It is inevitable that a positional shift occurs between the vapor deposition position and the vapor deposition position of the vapor deposition substance during actual vapor deposition. Therefore, if a material with a small coefficient of linear expansion, such as Invar material, is used as the material for forming the frame 3 that holds the mask body 2, dimensional changes and shape changes due to the expansion of the mask body 2 when the temperature rises. The alignment accuracy at room temperature can be well maintained even when the temperature is increased during vapor deposition.

In FIG. 6, reference numeral 9 indicates a metal layer that joins the outer peripheral edge 4a of the pattern forming area 4 of the mask body 2 and the frame 3. The metal layer 9 is formed by a plating method, and is made of electroformed metal such as nickel or nickel-cobalt alloy. In this way, if the outer periphery 4a of the pattern forming area 4 of the mask body 2 and the frame 3 are bonded with the metal layer 9, this is unavoidable when the mask body 2 and the frame 3 are bonded with adhesive. However, there were no problems such as deterioration of the adhesive due to the organic solvent used in the cleaning process etc. acting on the adhesive, and a good bonding state between the mask body 2 and the frame 3 was maintained. Can be maintained well over long periods of time.

Moreover, in this embodiment, as shown in FIGS. 6 to 8, a large number of through holes 21 are provided all around the outer periphery 4a of the pattern forming area 4 of the mask body 2, and the pattern forming area 4 of the mask body 2 is It is noteworthy that the outer peripheral edge 4a of the region 4 and the frame 3 are integrally joined via a metal layer 9 formed so as to fill the through hole 21. That is, the metal layer 9 according to the present embodiment is formed on the upper surface of the outer peripheral edge 4a of the pattern forming region 4, the upper surface of the frame 3 and the side surface facing the pattern forming region 4, and the gap between the mask body 2 and the frame 3. Not only that, but it is noteworthy that it is grown and formed so as to fill the through hole 21. In this way, when the mask body 2 and the frame body 3 are bonded via the metal layer 9 grown and formed so as to fill the through hole 21, it is possible to improve the bonding strength between the two parts 2 and 3. Therefore, it is possible to reliably prevent the mask body 2 from falling off or being misaligned with respect to the frame 3. Therefore, it is possible to improve the reproducibility and vapor deposition accuracy of the light emitting layer.

Further, as shown in FIGS. 7 and 8, the four corners of the mask body 2 are chamfered in plan view. According to this, when the mask main body 2 thermally expands, it is possible to suppress concentration of stress at the corners. In addition, in FIGS. 7 and 8, the vapor deposition through hole 5 is not composed of a small hole portion 5a and a large hole portion 5b, but is represented as a straight hole.

10 to 12 show a method for manufacturing a deposition mask according to this embodiment. First, as shown in FIG. 10(a), a photoresist layer 11 is formed on the surface of a matrix 10. The matrix 10 is preferably made of a material that is conductive and has a low-temperature expansion coefficient, such as 42 alloy, Invar, SUS430 (stainless steel), and the like. The photoresist layer 11 is formed by laminating one or several negative-type photosensitive dry film resists to a predetermined height and bonding them under heat.

Next, on the photoresist layer 11, a patterned film (glass mask) having light-transmitting holes corresponding to the positions of the large holes 5b of the vapor deposition holes 5 and the holes 21 for increasing adhesive strength is closely attached. By performing exposure by irradiating ultraviolet light, developing and drying, and dissolving and removing the unexposed portion, the large hole portion 5b of the vapor deposition through hole 5 and the A primary pattern resist 12 having a straight resist body 12a corresponding to the position of the through hole 21 was formed on the matrix 10.

Next, the mother mold 10 is placed in an electroforming bath prepared under predetermined conditions, and as shown in FIG. A first metal layer 13 was formed on the uncovered surface (exposed area) by electroforming a nickel-cobalt alloy, preferably in the range of 5 to 90 μm thick, in this example 16 μm thick. After forming the first metal layer 13, the primary pattern resist 12 (resist body 12a) is removed, as shown in FIG. 10(d). Here, the first metal layer 13 may have a two-layer structure including a bright nickel layer and a matte nickel layer. In this case, an electrodeposition layer made of bright nickel is electroformed to a thickness of 5 μm on the matrix 10, and then an electrodeposition layer made of matte nickel is electroformed to a thickness of 11 μm thereon. In this way, if the first metal layer 13 has a two-layer structure, bright nickel is less likely to stick to the matrix 10, and the final step of peeling off the vapor deposition mask 1 from the matrix 10 can proceed efficiently. . Note that in FIG. 10(d), the reference numeral 13a indicates the first metal layer formed between the mask bodies 2.

Subsequently, as shown in FIG. 11(a), a photoresist layer 14 was formed on the entire surface of the mother mold 10, including the region where the first metal layer 13 was to be formed. This photoresist layer 14 is formed by laminating one or several negative-type photosensitive dry film resists to a predetermined height and bonding them by thermocompression.

Next, a patterned film having light-transmitting holes corresponding to the positions of the small holes 5a of the vapor deposition holes 5 is closely attached, and then exposed to ultraviolet light, developed, and dried. By removing the portion, a secondary pattern resist 15 having a straight resist body 15a corresponding to the position of the small hole portion 5a of the vapor deposition through hole 5 was formed on the matrix 10, as shown in FIG. 11(b). .

Next, the mother mold 10 is placed in an electroforming bath prepared under predetermined conditions, and as shown in FIG. A second metal layer 16 was formed by electroforming a nickel-cobalt alloy onto the surface (exposed region) not covered with the resist body 16a of No. 13 to a thickness of preferably 10 μm or less, in this embodiment, 4 μm. . At this time, the second metal layer 16 formed in the portion facing the end (top or root) of the first metal layer 13 has an R shape. Further, the end portion of the second metal layer 16 facing the vapor deposition through hole 5 also has a rounded shape. Note that the desired curvature of R can be obtained by adjusting the thickness of the second metal layer 16. By removing the secondary pattern resist 15 (resist body 15a), as shown in FIG. A mask body 2 was obtained which was provided with a through hole 21 for increasing the bonding strength. Each corner of the mask body 2 is chamfered in plan view, as shown in FIGS. 7 and 8. Note that in FIG. 11(d), the reference numeral 16a indicates a second metal layer formed between the mask bodies 2, 2, and is formed on the first metal layer 13a.

Subsequently, as shown in FIG. 12(a), a photoresist layer 17 was formed on the entire surface of the master mold 10, including the portion where the first metal layer 13 and the second metal layer 16 (mask body 2) were to be formed. This photoresist layer 17 is formed by laminating one or several negative-type photosensitive dry film resists to a predetermined height and bonding them under heat as before. Next, a patterned film having transparent holes corresponding to the pattern forming area 4 was brought into close contact with the film, and then exposed to ultraviolet light. In this way, a photoresist layer 17 is obtained in which the portion corresponding to the pattern forming area 4 is exposed (17a) and the other portion is unexposed (17b), and then a matrix is formed as shown in FIG. 12(b). The frame body 3 was arranged on the metal layer 10 so as to surround the first metal layer 13 and the second metal layer 16. Here, the frame 3 was temporarily fixed onto the matrix 10 by utilizing the adhesiveness of the unexposed photoresist layer 17b.

Next, as shown in FIG. 12C, the unexposed photoresist layer 17b exposed on the surface was dissolved and removed to form a tertiary pattern resist 18 having a resist body 18a covering the pattern formation area. Note that at this time, the unexposed photoresist layer 17b existing on the lower surface of the frame 3 remains on the matrix 10.

Next, as shown in FIG. 12(d), the upper surface of the second metal layer 16 exposed on the surface of the outer peripheral edge 4a of the pattern forming area 4, and the matrix exposed between the frame 3 and the second metal layer 16. Electrodeposited metal is electroformed on the surface of 10, on the surface of the frame 3, and in the through hole 21 to form a metal layer 9, and the metal layer 9 forms the first electrodeposition layer 13 and the second metal layer 16 ( The mask body 2) and the frame body 3 were integrally joined. Note that before forming the metal layer 9, the first electrodeposited layer 13 around the through hole 21, specifically, the inner wall surface of the through hole 21 and the upper surface of the first electrodeposited layer 13 around the through hole 21, are By performing treatments such as acid immersion, electrolytic treatment, and strike plating, it is possible to improve the bonding strength between the treated portion and the metal layer 9.

Finally, after peeling off the first metal layer 13, second metal layer 16, and metal layer 9 from the matrix 10, the first metal layer 13a existing on the lower surface of the frame 3 is peeled off from these metal layers, and the third metal layer 13a is peeled off from these metal layers. By removing the patterned resist 18 and the unexposed photoresist layer 17b, a vapor deposition mask 1 as shown in FIG. 6 was obtained.

(Third embodiment)
A vapor deposition mask according to a third embodiment of the present invention will be described based on FIGS. 13 to 15. The mask body 2 (evaporation mask 1) in each of the above embodiments is manufactured by electroforming after forming a pattern resist on the surface of a conductive substrate using a conductive substrate as a matrix. It can also be manufactured using 13 and 14 show a method for manufacturing a vapor deposition mask according to this embodiment, and each step of the manufacturing method will be described below.

First, as shown in FIG. 13(a), a matrix 40 on which a metal film 41 is formed is prepared. For the mother die 40, an insulating substrate such as a glass plate or a resin plate is used, for example. Further, the metal film 41 is made of a conductive metal such as chromium or titanium. This metal film 41 is produced by depositing a metal film on the entire surface of the master mold 40 by sputtering, forming a resist pattern using photolithography, and then removing the metal film exposed from the resist pattern by etching. By removing the metal film 41, a pattern is formed on the surface of the master mold 40. A first metal layer 44 and a second metal layer 45, which will be described later, are formed on the metal film 41 thus patterned, and the space between the metal films 41 corresponds to the position of the small hole portion 5a of the vapor deposition through hole 5. In this embodiment, a glass plate is used as the matrix 40 and chromium is used as the metal film 41, and the thickness of the metal film 41 is 1 μm or less.

Next, as shown in FIG. 13(b), a photoresist layer 42 is formed on the surface of the master mold 40. The photoresist layer 11 is formed by laminating one or several negative-type photosensitive dry film resists to a predetermined height and bonding them under heat.

Next, a patterned film (glass mask) having transparent holes corresponding to the formation positions of the first metal layer 44 is closely attached onto the photoresist layer 42, and then exposed to ultraviolet light and developed. By performing each drying process and removing the unexposed portion, a patterned resist 43 having a straight resist body 43a corresponding to the formation position of the first metal layer 44 is formed as shown in FIG. 13(c). It was formed on a matrix 40.

Next, the mother mold 40 is placed in an electroforming bath prepared under predetermined conditions, and as shown in FIG. A first metal layer 44 was formed on the uncovered surface (exposed area) by electroforming a nickel-cobalt alloy, preferably in the range of 5-90 μm thick, in this embodiment 16 μm thick. Note that before forming the first metal layer 44, an oxide film, an organic film, a polymer film, or the like may be formed on the surface of the metal film 41 exposed from the resist body 43a.

Next, as shown in FIG. 14(b), the pattern resist 43 (resist body 43a) is removed.

Next, the mother mold 40 is placed in an electroforming bath prepared under predetermined conditions, and as shown in FIG. 14(c), a nickel-cobalt alloy is coated on the surfaces of the metal film 41 and the first metal layer 44, preferably to a thickness of 10 μm. The second metal layer 45 was formed by electroforming to a thickness of 4 μm in this embodiment. At this time, the second metal layer 45 formed in the portion facing the end portions (top and base) of the metal film 41 and the first metal layer 44 has an R shape. Thereby, shadows caused by the upper end peripheries of the large hole portion 5b and the small hole portion 5a can be completely eliminated. Note that the desired curvature of R can be obtained by adjusting the thickness of the second metal layer 45. Further, before forming the second metal layer 45, an oxide film, an organic film, a polymer film, etc. may be formed on the surfaces of the metal film 41 and the first metal layer 44.

Finally, by peeling off the first metal layer 44 and the second metal layer 45 from the matrix 40, a vapor deposition through hole 5 having a small hole 5a and a large hole 5b as shown in FIG. 15 is formed. A mask body 2 (vapor deposition mask 1) was obtained.

The mask main body 2 in this embodiment has a minute recess 50 on the back side of the first metal layer 44 (on the deposition target substrate 30 side). The shape of this minute recess 50 is formed to correspond to the shape of the metal film 41. Due to the presence of such micro-dents 50, the outer peripheral part of the micro-dents 50 (the peripheral part of the small hole portion 5a on the side of the deposition target substrate 30) has a protruding shape. When performing vapor deposition on the vapor deposition target substrate 30, the vapor deposition mask 1 can be placed in close contact with the vapor deposition target substrate 30 due to the line contact between the periphery of the vapor deposition through hole 5 of the mask body 2 and the vapor deposition target substrate 30, and the vaporization from the vaporization source can be carried out. This prevents the organic material from bleeding or being deposited on the back surface of the deposition mask 1.

In each of the embodiments described above, the metal layer 9 is formed under such tension that a tensile stress F1 is applied to draw the first metal layer 13 and the second metal layer 16, that is, the mask body 2 toward the frame body 3. can do. Application of such tensile stress can be realized by adjusting the content ratio of carbon in the second type brightener added to the electroforming bath. As a result, the first metal layer 13 and the second metal layer 16 are stretched with a tensile stress acting on the frame 3 through the metal layer 9, so that the ambient temperature during the vapor deposition operation is reduced. Even when the mask body 2 rises, it absorbs the expansion of the mask body 2 due to the difference in thermal expansion coefficient with the frame 3, making it difficult for the vapor deposition mask 1 to have variations in dimensional accuracy due to heat, and improving the reproducibility and vapor deposition accuracy of the light emitting layer. Can contribute to improvement. Furthermore, by using a material that is difficult to thermally expand as the frame body 3 that holds the mask body 2, the influence of heat can be suppressed as much as possible.

Furthermore, in each of the above embodiments, the mask body 2, that is, the first metal layer 13 and the second metal layer 16, is formed under such tension that a stress F2 is applied in a direction that causes the mask body 2 to contract inward. You can also. This tensile stress F2 is caused by the temperature difference between the temperature of the electroformed layer (40 to 50°C) when creating the first metal layer 13 and the second metal layer 16 and room temperature (20°C). This can be achieved by causing the first metal layer 13 and the second metal layer 16 to contract. To explain in more detail, a material with a low-temperature expansion coefficient such as 42 alloy, Invar, or SUS430 (stainless steel) is used as the matrix 10, and the first metal layer 13 and the second metal layer are formed in an electroformed layer at 40 to 50°C. When the layer 16 is formed, the first metal layer 13 and the second metal layer 16 made of nickel or nickel alloy have a larger expansion coefficient than the mother mold 10, so stress that tends to expand acts on the mother mold ( However, the expansion of the metal layer 9 at this time is regulated by the matrix 10). However, at room temperature (20° C.) lower than the electroformed layer temperature (40 to 50° C.), the first metal layer 13 and the second metal layer 16 tend to contract inward, and therefore peel off from the matrix 10. As a result, tensile stress F2 acts on the first metal layer 13 and the second metal layer 16, that is, the mask body 2, with respect to the frame body 3. As a result, the mask body 2 can be kept in a taut state without wrinkles, so that even when the ambient temperature rises during vapor deposition, the mask body 2 itself expands due to the difference in thermal expansion coefficient with the frame 3. By absorbing the heat, the vapor deposition mask 1 is unlikely to have variations in dimensional accuracy due to heat, and can contribute to improving the reproducibility and vapor deposition accuracy of the light emitting layer. Moreover, by forming the through holes 21, chamfering the corners of the mask body 2, and making the frame 3 itself which holds the mask body 2 made of a material that is difficult to thermally expand, variations in dimensional accuracy due to heat can be achieved. This can further contribute to improving the reproducibility and deposition accuracy of the light-emitting layer.

Further, in each of the above embodiments, when the master mold is peeled off, the first metal layer 13/44 and the second metal layer 16/45 may be peeled off from the interface. In order to prevent this, before forming the second metal layers 16 and 45 on the first metal layers 13 and 44, the surfaces of the first metal layers 13 and 44 are subjected to surface activation treatment (acid immersion, cathode dipping, etc.). Electrolysis, chemical etching, strike plating, etc.) are recommended. In addition, as shown in FIG. 16, an overhang 60 may be formed at the upper edge of the first metal layer 13/44, and a second metal layer 16/45 may be formed on the first metal layer 13/44. Thus, separation between the first metal layers 13 and 44 and the second metal layers 16 and 45 can be prevented. When forming the first metal layers 13 and 44, the overhanging portions 60 are formed by electroforming, so-called overhanging, beyond the thickness of the resist bodies 12a and 43a, so that the upper ends of the first metal layers 13 and 44 are formed. It is possible to obtain a shape in which a projecting portion 60 having an eave-shaped cross section is integrally formed on the periphery.

The number of mask bodies 2 that the vapor deposition mask 1 has is not limited to those shown in the above embodiments. Furthermore, the second metal layer 16 may be formed after the first metal layer 13 is polished and smoothed before or after removing the primary pattern resist 12. Further, the second metal layer 16 may be polished and smoothed before or after removing the secondary pattern resist 15, and then the tertiary pattern resist 18 may be formed in the pattern forming region 4. As for the material of the frame 3, in addition to metal materials such as the invar material shown in the embodiment, materials with a low linear thermal expansion coefficient as close as possible to glass, which is the substrate to be evaporated, such as glass or ceramic, may be used. You can choose. In this case, it is necessary to impart electrical conductivity to at least the surface of these materials. Furthermore, a fixing frame made of stainless steel, aluminum, or the like may be separately fixed to the outer peripheral edge of the formed vapor deposition mask 1 in a stretched state using a known method. However, in the case where each mask body 2 is held in the frame 3 under tension via the metal layer 9 as in the embodiment, a so-called frameless structure that does not require a fixed frame is possible.

1 Vapor deposition mask 2 Mask body 3 Frame 4 Pattern formation area 4a Outer periphery of pattern formation area 5 Vapor deposition through hole 6 Vapor deposition pattern 9 Metal layer 10 Mother mold 12 Primary pattern resist 13 First metal layer 15 Secondary pattern resist 16 Second Metal layer 17 Pattern film 18 Tertiary pattern resist 21 Through hole 40 Matrix 43 Pattern resist 44 First metal layer 45 Second metal layer 50 Microdent 60 Overhang

Claims (5)

A vapor deposition mask in which a vapor deposition pattern 6 consisting of a large number of independent vapor deposition holes 5 is provided on a mask body 2,
The vapor deposition through hole 5 is formed by communicating a small hole 5a located on the side of the substrate to be vaporized and a large hole 5b located on the vaporization source side and formed larger than the opening shape of the small hole 5a. It is composed of
The mask main body 2 includes a lower part having the small hole 5a and extending in the horizontal direction, and an upper part having the large hole 5b and extending upward from the lower part,
The lower part has a micro recess 50 on the side of the substrate to be deposited,
The vapor deposition mask is characterized in that, in a cross-sectional view of the mask body 2 , the width of the minute recess 50 is smaller than the width of the lower part and larger than the width of the upper part . 2. The vapor deposition mask according to claim 1, wherein, in a cross-sectional view of the mask body 2, the width dimension of the minute recess 50 is smaller than the width dimension of the lower part on the deposition target substrate side. 3. The vapor deposition mask according to claim 1, wherein, in a cross-sectional view of the mask body 2, a width dimension of the minute recess 50 is smaller than a width dimension of the lower part on the vaporization source side. 4. The vapor deposition mask according to claim 1 , wherein, in a cross-sectional view of the mask main body 2, a width dimension of the minute recesses 50 is larger than a width dimension of the upper stage portion on the deposition target substrate side. 5. The vapor deposition mask according to claim 1 , wherein, in a cross-sectional view of the mask body 2, the width dimension of the minute recess 50 is larger than the width dimension on the vaporization source side of the upper stage part.

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