JP2015066818A - Metal mask manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method capable of easily, accurately forming a metal mask that can attain a printed matter with a uniform thickness.SOLUTION: A first pattern resit corresponding to a mask main body is formed on a surface of a matrix (first-pattern-resist forming step). Using the first pattern resist, a first metallic layer is formed on the surface of the matrix (first-metallic-layer forming step). The first pattern resist is removed (first-pattern-resist removing step). A second pattern resist corresponding to a support is formed on surfaces of the matrix and the first metallic layer (second-pattern-resist forming step). Using the second pattern resist, a second metallic layer is formed on the surface of the first metallic layer (second-metallic-layer forming step). The second pattern resist is removed (second-pattern-resist removing step). A metal mask is thereby manufactured.

Description

  The present invention relates to a method of manufacturing a metal mask having a support portion around an opening through which a material such as ink, paste, cream, or ball can be inserted.

  Patent Document 1 is disclosed as a metal mask (printing mask) for screen printing. As shown in FIG. 7, the metal mask described in Patent Document 1 includes a mesh portion 101 and a base portion 102 thicker than the surrounding mesh portion 101, and a bridge girder-like column in a space portion below the mesh portion 101. 103 is provided. When printing is performed using the metal mask having such a configuration, the bridge girder-like support column 103 provided in the space portion under the mesh portion 101 is supported, so that the mesh portion 101 is deformed in the dent direction by squeegee pressure. Since this can be prevented, the paste can be printed with a uniform thickness.

JP-A-6-328873

  Such a metal mask can be produced by an electroforming method. Specifically, as shown in FIG. 8, after a predetermined pattern resist (portion 101a portion of the mesh portion 101) R1 is formed on the conductor 210 by an insulator (resist), electroplating is performed to insulate the resist. The body is removed with a solution to form a first-layer plating film 211. Further, after another pattern resist (space portion under the mesh portion 101 excluding the portion corresponding to the support pillar 103) R2 is formed on the first layer plating film 211 by an insulator in the same manner. Then, electroplating is performed and the insulator is removed with a solution to form a second layer plating film 212. These first layer and second layer plating films are peeled together to produce the screen printing plate described above. As a result, the support column 103 can be formed simultaneously with the formation of the second layer plating film 212 for forming the space below the mesh portion 101.

  The second layer plating film 212 corresponding to the support column 103 must be formed at a position excluding the hole 101a of the first layer plating film 211 corresponding to the mesh portion 101. In the manufacturing method, In order to form the second layer plating film 212, another pattern resist R2 is newly formed on the first layer plating film 211. In forming this other pattern resist R2, The smaller the pitch of the holes 101a, that is, the smaller the portion excluding the holes 101a of the mesh portion 101 (the first layer plating film 211), the more difficult. Further, as shown in FIG. 9, in the case where the inner wall surface of the hole 101a on the base portion 102 side is formed in a straight shape without a step, the positions of the plating film 211 and the plating film 212 corresponding to this portion are accurately positioned. It must be formed to fit together, and this point was also difficult. This invention is providing the manufacturing method of the metal mask which can solve the said subject.

  The present invention includes an opening 3 formed in a desired shape, a rib 4 formed in the opening 3, and a column 5 formed in the rib 4 in the mask body 2, and the rib 4 is formed so that one surface thereof is flush with one surface of the mask body 2, and an end surface of the support column portion 5 formed on the other surface of the rib portion 4 is flush with the other surface of the mask body 2. It is a manufacturing method of the formed metal mask. According to the manufacturing method, a first pattern resist forming step of forming a first pattern resist corresponding to the mask body on the surface of the mother mold, and a first metal layer is formed on the surface of the mother mold using the first pattern resist. A first metal layer forming step to be formed; a first pattern resist removing step of removing the first pattern resist; and a second pattern resist corresponding to the support portion on the surface of the matrix and the first metal layer. A pattern resist forming step, a second metal layer forming step for forming a second metal layer on the surface of the first metal layer using the second pattern resist, and a second pattern resist removing step for removing the second pattern resist It is characterized by having.

  The second pattern resist forming step includes forming a second resist layer on the surface of the matrix exposed from the first metal layer, and forming a second resist layer on the surfaces of the first metal layer and the second resist layer. And a third resist layer forming step for forming the third resist layer, and an exposure / development step for exposing and developing the second resist layer and the third resist layer.

  Further, in the first pattern resist forming step, the first pattern resist has a resist body corresponding to the formation position of the opening formed in the mask body, and the resist body has a desired shape dimension. It is formed as described above.

  According to the manufacturing method of the present invention, a metal mask can be manufactured easily and accurately.

It is the whole composition perspective view and partial enlarged plan view of the metal mask concerning the present invention. It is a fragmentary sectional view of the metal mask concerning the present invention. It is explanatory drawing of the manufacturing method of the metal mask which concerns on this invention. It is explanatory drawing of the manufacturing method of the metal mask which concerns on this invention. It is explanatory drawing of the manufacturing method of the other metal mask which concerns on this invention. It is explanatory drawing of the manufacturing method of the other metal mask which concerns on this invention. It is sectional drawing of a metal mask. It is explanatory drawing of the manufacturing method of a metal mask. It is sectional drawing of a metal mask.

(First embodiment)
FIG. 1 shows a metal mask according to the present invention. 1A is a perspective view of the entire configuration of a metal mask according to the present invention, FIG. 1B is a partially enlarged plan view of FIG. 1A, and FIG. It is the partial expanded back view which looked at (b) from the other side. This metal mask (hereinafter sometimes simply referred to as a mask) 1 is used as a printing mask for printing printed matter such as solder paste, and as an arrangement mask for arranging mounted items such as solder balls. Here, the following description will be given on the assumption that the mask is a printing mask. FIG. 2 is a partial cross-sectional view in FIGS. 1B and 1C, and reference numeral 7 in FIG. 2 indicates a workpiece to be printed with a material such as a solder paste by the mask 1. The workpiece 7 includes a wafer and a substrate, and electrode portions serving as input / output terminals are formed on the upper surface of the workpiece 7 in a predetermined pattern.

  As shown in FIGS. 1 and 2, the mask 1 has a mask body 2 formed of a nickel alloy such as nickel or nickel-cobalt, copper or other metal as a material, and an opening 3 having a desired shape is formed. Yes. As shown in FIG. 2, the openings 3 are arranged in a pattern corresponding to the positions where the electrode portions are formed on the work 7. The shape of the opening 3 is not limited to a square shape, but may be a polygonal shape, a circular shape, a semicircular shape, a C shape, or a curved shape. Moreover, the side surface in the opening part 3 is formed in the straight shape.

  A frame body can be attached to the mask body 2. This frame is a flat plate made of, for example, aluminum, 42 alloy, Invar, SUS430, or the like, and has one rectangular opening corresponding to the mask body 2 at the center of the board surface. The mask body 2 is held by a single frame. The frame body is a molded product that is thicker than the mask body 2. When the frame body is mounted on the mask body 2, the frame body is joined to the outer peripheral edge of the mask body 2 in an integral manner.

  In the opening 3 of the mask body 2 (mask 1), a rib portion 4 is formed for adjusting the printing amount of printed matter such as solder paste. The rib part 4 can be freely set in the opening part 3, and the printing amount can be finely adjusted by setting the shape, the number, and the formation position of the rib part 4. The arrangement of the ribs 4 includes a line shape, a honeycomb shape, a lattice shape, a mesh shape, a radial shape, and the like. Of course, the shape defined by the rib portion 4 and the peripheral edge of the rib portion 4 or the rib portion 4 and the opening 3 is not limited to a square shape, but may be a triangular shape, a hexagonal shape, other polygonal shapes, or a circular shape.

  A column portion 5 is formed on the rib portion 4 formed in the opening 3. In detail, the support | pillar part 5 is protrudingly formed in the other surface 4B used as the surface on the opposite side to 1 A of 1 A of rib parts. As shown in FIG. 2, the support 5 serves as a support against the pressing force from above by the squeegee 8 during printing, can prevent the formation region of the opening 3 from being deformed in the dent direction, Printed matter) 9 can be printed with a uniform thickness. The shape of the column portion 5 can be a prismatic shape, a cylindrical shape, or the like. Moreover, it is preferable that the width dimension of the support | pillar part 5 (the length of a long side in the case of a prismatic shape, the diameter in the case of a cylinder shape) is the same as or less than the width dimension of the rib part 4.

  The dimension obtained by adding the thickness dimension (T1) of the rib part 4 and the height dimension (T2) of the column part 5 is the same as the thickness dimension (T3) of the mask body 2 (metal mask 1) (T3 = T1 + T2). Further, one surface (squeegee surface) 2A of the mask body 2 is formed so as to be flush with one surface 4A of the rib portion 4, and the other surface (printing surface) 2B of the mask body 2 is flush with the end surface 5B of the support column 5. It is formed to become. In the metal mask 1 of the present embodiment, the printing amount is adjusted to an appropriate amount by appropriately setting the shape, dimensions (thickness and width), number of ribs 4, the number of the ribs 4, the formation position, and the height of the column 5. Can be obtained, and a printed matter having a uniform thickness can be obtained. Note that the thickness of the mask body 2 (metal mask 1) is preferably 15 μm or more, and is set to 20 μm here. Further, the thickness of the rib portion 4 is preferably 5 μm or more, and is set to 10 μm here, and the height of the column portion 5 is preferably 5 μm or more, and is set to 10 μm here.

  Next, a method for manufacturing the metal mask 1 having such a configuration is shown in FIGS. First, as shown in FIG. 3A, a first resist layer 31 is formed on the surface of a mother mold 30 having conductivity, for example, made of stainless steel or brass steel. The first resist layer 31 is formed by, for example, laminating one or several negative photosensitive dry photoresists to a predetermined height and then thermocompression bonding.

  Next, after a pattern film (glass mask) A having a light transmitting hole corresponding to the mask body 2 is brought into close contact with the first resist layer 31, exposure is performed by irradiating ultraviolet light with an ultraviolet lamp. The first pattern resist 32 having the first resist body 32a is formed on the surface of the mother die 30 as shown in FIG. 3B by dissolving and removing the unexposed portions by performing each treatment of drying. (First pattern resist forming step). At this time, the first pattern resist 32 can be tapered by using a photoresist that does not easily transmit ultraviolet light or by reducing the exposure amount.

  Next, it is placed in an electroforming tank bathed under a predetermined condition and covered with the first pattern resist 32 of the matrix 30 within the range of the height of the first pattern resist 32 as shown in FIG. The first metal layer 33 is formed by electroforming an electrodeposited metal such as nickel or copper on the unfinished surface (first metal layer forming step).

  Next, as shown in FIG. 3D, the first pattern resist 32 is removed (first pattern resist removing step). Here, it is preferable to polish the surface of the first metal layer 33.

  Next, as shown in FIG. 4A, a second resist layer 34 is formed on the surface of the mother die 30 that is not covered with the first metal layer 33 (second resist layer forming step). The second resist layer 34 supplies a liquid resist to the surfaces of the mother die 30 and the first metal layer 33, and the first metal layer 33 is formed on the surface of the mother die 30 that is not covered with the first metal layer 33. It is formed by coating up to the thickness of and removing unnecessary resist.

  Next, as shown in FIG. 4B, a third resist layer 35 is formed on the surfaces of the first metal layer 33 and the second resist layer 34 (third resist layer forming step). Similarly to the first resist layer 31, the third resist layer 35 may be formed by laminating one or several negative photosensitive dry photoresists according to a predetermined height and then thermocompression bonding.

  Next, after a pattern film (glass mask) B having a light transmitting hole corresponding to the support portion 5 is brought into close contact with the third resist layer 35, exposure is performed by irradiating with ultraviolet light with an ultraviolet lamp. Then, each of the drying processes is performed to dissolve and remove the unexposed portions, thereby forming the second pattern resist 36 on the surface of the mother die 30 and the first metal layer 33 as shown in FIG. Second pattern resist forming step). Here, by exposing and developing the third resist layer 35, the second resist layer 34 is simultaneously exposed and developed (exposure / development step).

  Next, it is put in an electroforming bath built under predetermined conditions, and as shown in FIG. 4D, the surface of the first metal layer 33 has nickel, copper, etc. at the height of the second pattern resist 36. The second metal layer 37 is formed by electroforming the electrodeposited metal (second metal layer forming step).

  Finally, the mother die 30 and the second pattern resist 36 are removed. Specifically, the second pattern resist 36 is dissolved and swollen and removed (second pattern resist removing step), and the mother die 30 is peeled and removed. As shown in FIG. 4 (e) and FIG. 1, the metal mask 1 is obtained.

  According to this manufacturing method, the metal mask 1 can be manufactured with high accuracy by electroforming. In particular, by forming the rib part 4 and the column part 5 by electroforming, the rib part 4 and the column part 5 can be set with high precision and freedom, which can contribute to printing with a uniform thickness.

(Second Embodiment)
Then, the manufacturing method of the metal mask which concerns on 2nd Embodiment is demonstrated. In addition, the same code | symbol is attached | subjected to the same member as the above-mentioned composition, and the explanation is omitted.

  In the first embodiment, the first pattern resist 32 is formed so as to correspond to the mask body 2, the first metal layer 33 is formed using the first pattern resist 32, and the first pattern resist 32 is removed. Thus, the mask main body 2 is obtained, and the shape / dimension of the first resist body 32 a included in the first pattern resist 32 appears as the shape / dimension of the opening 3. In contrast, in the present embodiment, the first resist body 42 a of the first pattern resist 42 corresponding to the opening 3 is formed larger than the desired shape and size of the opening 3. A method for manufacturing a metal mask according to the following will be described.

  First, as shown in FIG. 5A, the first resist layer 41 is formed on the surface of the mother die 40 as in the first embodiment.

  Next, the pattern film (glass mask) C is brought into intimate contact with the first resist layer 41, exposed, developed, and dried, and the unexposed portions are dissolved and removed. The first pattern resist 42 is formed (first pattern resist forming step). As shown in FIG. 5B, the first pattern resist 42 includes a first resist body 42a, and the first resist body 42a. The outer dimension (h) is made larger than the desired outer dimension of the opening 3. Preferably, it is formed to be 1.1 to 10 times the size of the desired opening 3. More preferably, it is formed to be 1.1 to 2.0 times the dimension of the desired opening 3.

  Next, as shown in FIG. 5C, a first metal layer 43 is formed on the surface of the mother die 40 that is not covered with the first pattern resist 42 (first metal layer forming step), and FIG. As shown in FIG. 6, the first pattern resist 42 is removed (first pattern resist removing step), and as shown in FIG. 6A, the second resist layer 44 and the first resist layer 44 are formed on the surfaces of the mother die 40 and the first metal layer 43. 3 resist layers 45 are formed (second resist layer forming step, third resist layer forming step).

  Next, the pattern film (glass mask) D is brought into close contact with the third resist layer 45, and exposure, development, and drying are performed, and the unexposed portions are dissolved and removed. A second pattern resist 46 is formed on the surface of the layer 43 (second pattern resist forming step). Here, the pattern film (glass mask) D has a desired outer dimension (H) of the opening 3 and a column portion. A light-transmitting hole corresponding to 5 is used. Thereby, the second resist layer 44 is exposed so as to correspond to the desired outer dimension (H) of the opening 3, and the third resist layer 45 is exposed so as to correspond to the support column 5. Thereafter, development and drying are performed to dissolve and remove the unexposed portions (exposure / development process), whereby the second pattern resist 46 is formed. Here, when the first pattern resist 42 is formed, the outer dimension (h) of the first resist body 42a included in the first pattern resist 42 is formed larger than the desired outer dimension of the opening 3, so that FIG. ), A gap portion S where the mother die 40 is exposed is formed between the first metal layer 43 and the second pattern resist 46. Subsequently, using the second pattern resist 46, the second metal is formed. By forming the layer 47 (second metal layer forming step), the second metal layer 47 is formed on the surface of the first metal layer 43 as shown in FIG. Also, the second metal layer 47 is formed.

  Finally, the second pattern resist 46 is removed (second pattern resist removing step), and the mother die 40 is removed, whereby the metal mask 1 is obtained as shown in FIG. 6D and FIG.

  Thus, in the present embodiment, when forming the first pattern resist 42 corresponding to the mask body 2 (rib portion 4), the outer dimension (h) of the first resist body 42a is changed to the outer dimension of the desired opening 3. When the second pattern resist 46 corresponding to the opening 3 and the support column 5 is formed, the outer dimension (H) of the second pattern resist 46 is formed in accordance with the desired actual outer dimension of the opening 3. To do. Thus, in the first embodiment, when the second pattern resist 36 is formed, the alignment of the pattern film B, that is, the outer edge of the second resist layer 34 (the boundary between the second resist layer 34 and the first metal layer 33). The pattern film B is placed on the second resist layer 34 so that the outer edges of the light transmission holes of the pattern film B are firmly aligned with each other. In this embodiment, the second pattern resist 46 is exposed. Is not required for the alignment of the pattern film D as in the first embodiment, and the positional deviation is allowed as long as it is within the range in which the second resist layer 44 is formed. Since the second resist layer 44 in the portion immediately below the exposed portion of the layer 45 is exposed together to form the second pattern resist 46, a desired opening portion is formed. Dimensions can be obtained easily and accurately. Although the gap portion S is generated when the second pattern resist 46 is formed, the metal layer 47 is formed in the gap portion S during the subsequent formation of the metal layer 47 (second metal layer forming step). Therefore, there is no problem in quality.

  In each of the above embodiments, the rib portion 4 and the column portion 5 (mask body 2) are integrally formed of the same member. For example, the rib portion 4 is formed of a magnetic material such as iron or nickel, and the column portion is formed. 5 can also be formed of a non-magnetic material such as copper or aluminum. Thereby, since the structure which fixes the metal mask 1 to the workpiece | work 7 with the magnetic attraction force of a magnet can be employ | adopted, a magnetic force can be made to act uniformly with respect to the metal mask 1, and the metal mask 1 is careless. There is no fear of bending, and the positional accuracy of the opening 3 with respect to the electrode portion can be improved.

  Moreover, the support | pillar part 5 may be formed not only with the metal but with resin. According to this, the cushion action derived from the elasticity of the resin is exhibited, and the possibility that the work 7 is damaged when the support column 5 comes into contact with the work 7 is reduced. In order to achieve this effect remarkably, in the metal mask 1, it is preferable to form all the portions in contact with the workpiece 7 with resin. Also by this, the magnetic force can be applied uniformly to the metal mask 1.

  Note that the mask 1 described in the drawings in each embodiment does not show the actual state of the mask, but schematically shows it, such as the opening size of the opening 3 and the thickness size of the mask body 2 and the like. These are shown in such dimensions for the convenience of drawing.

DESCRIPTION OF SYMBOLS 1 Metal mask 2 Mask main body 3 Opening part 4 Rib part 5 Support | pillar part 30,40 Master mold 31,41 1st resist layer 32,42 1st pattern resist 33,43 1st metal layer 34,44 2nd resist layer 35, 45 Third resist layer 36, 46 Second pattern resist 37, 47 Second metal layer

Claims (3)

An opening (3) formed in a desired shape in the mask body (2), a rib (4) formed in the opening (3), and a support column formed in the rib (4) The rib portion (4) is formed so that one surface thereof is flush with the one surface of the mask body (2), and is formed on the other surface of the rib portion (4). In the manufacturing method of the metal mask formed so that the end surface of the column portion (5) is flush with the other surface of the mask body (2),
A first pattern resist forming step of forming a first pattern resist (32, 42) corresponding to the mask body (2) on the surface of the matrix (30, 40);
A first metal layer forming step of forming a first metal layer (33, 43) on the surface of the matrix (30, 40) using the first pattern resist (32, 42);
A first pattern resist removing step of removing the first pattern resist (32, 42);
A second pattern resist forming step of forming second pattern resists (36, 46) corresponding to the support columns (5) on the surfaces of the matrix (30, 40) and the first metal layers (33, 43). When,
A second metal layer forming step of forming a second metal layer (37, 47) on the surface of the first metal layer (33, 43) using the second pattern resist (36, 46);
And a second pattern resist removing step of removing the second pattern resist (36, 46). The second pattern resist forming step includes:
A second resist layer forming step of forming a second resist layer (34, 44) on the surface of the matrix (30, 40) exposed from the first metal layer (33, 43);
A third resist layer forming step of forming a third resist layer (35, 45) on the surfaces of the first metal layer (33, 43) and the second resist layer (34, 44);
The method for producing a metal mask according to claim 1, further comprising an exposure / development step of exposing and developing the second resist layer (34, 44) and the third resist layer (35, 45). . In the first pattern resist forming step,
The first pattern resist (42) includes a resist body (42a) corresponding to a position where the opening (3) is formed in the mask main body (2), and the geometric dimensions of the resist body (42a). The metal mask manufacturing method according to claim 1, wherein the metal mask is formed larger than a desired shape dimension of the opening (3).