Mask for mounting a conductive material and method for manufacturing a mask for mounting a conductive material

Abstract

A mask (4) for mounting a conductive material comprises a first plating layer (10) and a second plating layer (20). The first plating layer (10) has a flat surface (10b) and is formed to be continuous without being divided into multiple parts. The second plating layer (20) covers the first plating layer (10) from the surface (10b) side and is formed to be continuous without being divided into multiple parts. A conductive material supply surface (4a) is formed by the first plating layer (10) and a thin sheet forming part. A plurality of opening patterns (6) are formed in the thin sheet forming part.

Description

Technology Field

[0001] The present disclosure relates to a mask for mounting a conductive material, used to mount a conductive material such as a solder ball or a copper pillar on a payload, and a method for manufacturing the mask for mounting a conductive material. Background Technology

[0002] Patent Document 1 describes a mask for mounting balls. The mask for mounting balls described in Patent Document 1 is manufactured by the following procedure.

[0003] First, a primary plating layer is formed on the base material. Next, the primary waste plating portion is peeled off from the base material, leaving the primary residual plating portion of the primary plating layer intact. Multiple separate, independent primary residual plating portions remain on the base material. Subsequently, a secondary plating layer is formed on the base material and the primary residual plating portions. A hole through which a conductive ball passes is formed in the secondary plating layer. Prior art literature

[0004] Patent Document 1: International Publication No. 2022 / 045073 The problem to be solved

[0005] In the ball-mounting mask described in Patent Document 1, there are multiple primary residual plating portions that are separated and independent. Because of this, in the said mask, the bonding area with the secondary plating layer for each primary residual plating portion is reduced, so there was a problem such as the primary residual plating portion being easily peeled off from the secondary plating layer during cleaning, for example.

[0006] The present disclosure was made to solve the problems described above. The purpose of the present disclosure is to provide a mask for mounting a conductive material that can suppress peeling of a plating layer. Another purpose of the present disclosure is to provide a method for manufacturing such a mask for mounting a conductive material. means of solving the problem

[0007] A mask for mounting a conductive material according to the present disclosure comprises a first plating layer formed as a continuous series without being divided into multiple parts, having a flat first surface, and a second plating layer formed as a continuous series without being divided into multiple parts, covering the first plating layer from the first surface side. A flat conductive material supply surface, to which a conductive material is supplied, is formed by a thin plate forming portion that does not overlap with the first plating layer among the first plating layer and the second plating layer. The distance between the second surface of the thin plate forming portion and the conductive material supply surface is smaller than the distance between the third surface of the thick plate forming portion that overlaps with the first plating layer among the second plating layer and the conductive material supply surface. The second surface and the third surface face in the same direction as the direction in which the first surface faces. A plurality of opening patterns are formed in the thin plate forming portion. Each of the plurality of opening patterns includes a plurality of through holes for passing a conductive material.

[0008] A method for manufacturing a mask for mounting a conductive material according to the present disclosure comprises: a first step of forming a first resist on a base material such that a region corresponding to a portion formed by a thin sheet forming portion of the conductive material supply surface is formed by a line; a second step of plating on the base material after the first step; a third step of removing the first resist after the second step; a fourth step of leaving a first plating layer on the base material by peeling off the plating formed on the region after the second step; a fifth step of forming a second resist corresponding to a plurality of through holes on a region of the base material after the third and fourth steps; and a sixth step of plating the first plating layer and the region of the base material and forming a second plating layer after the fifth step. Effects of the invention

[0009] If the mask for mounting a conductive material according to the present disclosure is used, peeling of the plating layer can be suppressed. Brief explanation of the drawing

[0010] FIG. 1 is a drawing showing an example of a plate having a mask for mounting a conductive material in Embodiment 1. Figure 2 is a drawing showing a cross-section of the plate shown in Figure 1. Figure 3 is a drawing showing an example of a mask for mounting a conductive material. Figure 4 is a drawing showing an example of a mask for mounting a conductive material. Figure 5 is a drawing showing the C-C cross-section of Figure 4. Figure 6 is an enlarged view of section D shown in Figure 5. Figure 7 is a drawing showing the E-E cross-section of Figure 4. Figure 8 is a drawing showing an example of a first plating layer. FIG. 9 is a flowchart showing an example of a method for manufacturing a mask for mounting a conductive material in Embodiment 1. FIG. 10 is a drawing illustrating a method for manufacturing a mask for mounting a conductive material. FIG. 11 is a drawing illustrating a method for manufacturing a mask for mounting a conductive material. FIG. 12 is a drawing showing an example of a first resist formed on a base material in the first process. FIG. 13 is a drawing showing another example of a mask for mounting a conductive material. FIG. 14 is a drawing showing another example of a mask for mounting a conductive material. Figure 15 is a diagram illustrating the process of forming a protrusion. Specific details for implementing the invention

[0011] The following is a detailed description with reference to the drawings. Redundant descriptions are appropriately simplified or omitted. In each drawing, the same reference numerals indicate the same part or corresponding part.

[0012] Embodiment 1.

[0013] FIG. 1 is a drawing showing an example of a plate (1) equipped with a mask (4) for mounting a conductive material in embodiment 1. FIG. 2 is a drawing showing a cross-section of the plate (1) shown in FIG. 1. The plate (1) is equipped with a frame (2), a mesh (3), and a mask (4) for mounting a conductive material. The mask (4) for mounting a conductive material is provided on the frame (2) through the mesh (3). The mesh (3) is arranged around the mask (4) for mounting a conductive material. Tension is applied to the mask (4) for mounting a conductive material by the mesh (3).

[0014] A mask (4) for mounting a conductive material is used to mount a solid conductive material, such as a solder ball or a copper filler, onto a substrate. The substrate is, for example, a substrate (5). When the conductive material is mounted onto the substrate, the mask (4) for mounting the conductive material is positioned above the substrate.

[0015] A plurality of conductive materials are supplied to the conductive material supply surface (4a) of the conductive material loading mask (4). The conductive material supply surface (4a) is flat. In the example shown in FIGS. 1 and 2, the conductive material supply surface (4a) is an upward surface. The conductive materials supplied to the conductive material supply surface (4a) pass through the conductive material loading mask (4) and are loaded at an appropriate location on the object to be loaded.

[0016] FIGS. 3 and FIGS. 4 are drawings showing examples of a mask (4) for carrying a conductive material. FIG. 3 is a view of the mask (4) for carrying a conductive material seen from direction B of FIG. 2. FIG. 3 shows a surface facing the object to be carried. Hereinafter, the said surface is also referred to as the facing surface. FIG. 4 is a view of the mask (4) for carrying a conductive material seen from direction A of FIG. 2. FIG. 4 shows the conductive material supply surface (4a). FIG. 5 is a drawing showing the cross-section C-C of FIG. 4. FIG. 6 is an enlarged view of section D shown in FIG. 5. FIG. 7 is a drawing showing the cross-section E-E of FIG. 4. Also, FIG. 2 shows a cross-section corresponding to FIG. 5.

[0017] A plurality of opening patterns (6) are provided in a mask (4) for mounting a conductive material. FIGS. 3 and 4 show an example in which the opening patterns (6) are regularly arranged in four vertical columns and three horizontal columns. The arrangement of the opening patterns (6) is arbitrarily set. Each of the plurality of opening patterns (6) includes a plurality of through holes (7) for passing a conductive material. The arrangement of the through holes (7) included in each opening pattern (6) may all be the same.

[0018] A mask (4) for mounting a conductive material comprises a first plating layer (10) and a second plating layer (20). The first plating layer (10) is formed by a plating method. FIG. 8 is a drawing showing an example of the first plating layer (10). FIG. 8 shows only the first plating layer (10) in FIG. 4.

[0019] The first plating layer (10) is plate-shaped and is formed as a continuous layer without being divided into multiple parts. The first plating layer (10) has a surface (10a) and a surface (10b). The surface (10a) and the surface (10b) are flat. The surface (10a) faces upward when the mask (4) for carrying a conductive material is placed on the object to be carried. The surface (10a) is part of the conductive material supply surface (4a). The surface (10b) faces in a direction opposite to the direction in which the surface (10a) faces. The surface (10b) faces downward when the mask (4) for carrying a conductive material is placed on the object to be carried.

[0020] It is preferable that the edge of the conductive material supply surface (4a) is entirely formed by the first plating layer (10). Additionally, it is preferable that the first plating layer (10) exists between each of two adjacent opening patterns (6) among the plurality of opening patterns (6) provided in the mask (4) for mounting the conductive material. For example, between opening pattern (6a) and opening pattern (6b), there is a portion of the first plating layer (10) indicated by reference numeral 10c. Between opening pattern (6a) and opening pattern (6c), there is a portion of the first plating layer (10) indicated by reference numeral 10d. Opening pattern (6a), opening pattern (6b), and opening pattern (6c) are each one of the plurality of opening patterns (6) provided in the mask (4) for mounting the conductive material.

[0021] Additionally, it is not mandatory for the first plating layer (10) to exist between each of the two adjacent opening patterns (6). For example, in the example shown in FIG. 4, the first plating layer (10) does not need to exist between the four upper opening patterns (6). However, for each opening pattern (6), it is preferable for the first plating layer (10) to exist between it and another opening pattern adjacent to the upper, lower, left, or right.

[0022] The second plating layer (20) is formed according to a plating method. The second plating layer (20) is provided to cover the first plating layer (10) from the surface (10b) side. For example, the second plating layer (20) covers the entire first plating layer (10) from the surface (10b) side. The second plating layer (20) is formed as a continuous layer without being divided into multiple parts.

[0023] The second plating layer (20) includes a portion that overlaps with the first plating layer (10) and a portion that does not overlap with the first plating layer (10). The thickness of the mask (4) for mounting a conductive material in the portion of the second plating layer (20) that overlaps with the first plating layer (10) is greater than the thickness of the portion of the second plating layer (20) that does not overlap with the first plating layer (10). Hereinafter, the portion of the second plating layer (20) that overlaps with the first plating layer (10) is also referred to as a thick plate forming portion. The portion of the second plating layer (20) that does not overlap with the first plating layer (10) is also referred to as a thin plate forming portion. Furthermore, it is preferable that the thin plate forming portion be composed solely of the second plating layer (20).

[0024] The second plating layer (20) has a surface (20a). The surface (20a) is the surface of the thin sheet forming portion and is the surface facing upward when the mask (4) for mounting a conductive material is placed on the object to be mounted. The surface (20a) is part of the conductive material supply surface (4a). That is, the surface (20a) faces in the same direction as the surface (10a). The surface (20a) and the surface (10a) form a coplanar plane.

[0025] In the example shown in the present embodiment, the area of ​​the conductive material supply surface (4a) other than the surface (10a) is the surface (20a). The conductive material supply surface (4a) is formed by the thin sheet forming portion of the first plating layer (10) and the second plating layer (20). FIG. 4 shows the most preferred example in which the area formed by the thin sheet forming portion of the conductive material supply surface (4a) is not divided into multiple parts but is continuous. This is an example. The area may be divided into multiple parts. For example, if the area is divided into multiple parts, it is preferable that at least one of the divided parts includes a plurality of opening patterns (6). Furthermore, it is even more preferable that each of the divided parts includes a plurality of opening patterns (6).

[0026] The opposing surface of the mask (4) for mounting a conductive material is formed by a second plating layer (20). As described above, the second plating layer (20) includes a thick plate forming section and a thin plate forming section. Additionally, the surface (20a) of the thin plate forming section is one with the surface (10a) of the first plating layer (10). Because of this, the second plating layer (20) is not in the shape of a perfect flat plate, and there are irregularities on the opposing surface.

[0027] The distance L1 between the conductive material supply surface (4a) and the surface (20b) of the thin plate forming section is smaller than the distance L2 between the conductive material supply surface (4a) and the surface (20c) of the thick plate forming section. The surface (20b) is the surface of the thin plate forming section and is the surface facing downward when the conductive material mounting mask (4) is placed on the object to be mounted. The surface (20b) is part of the opposing surface. The surface (20c) is the surface of the thick plate forming section and is the surface facing downward when the conductive material mounting mask (4) is placed on the object to be mounted. The surface (20c) is part of the opposing surface. The surface (20b) and the surface (20c) face in the same direction as the surface (10b).

[0028] As shown in FIGS. 5 to 7, the opposing surface of the mask (4) for mounting a conductive material has a convex shape in the thick plate forming part. In other words, the thin plate forming part has a concave shape. In this way, a concave part formed by the thin plate forming part is formed on the opposing surface of the mask (4) for mounting a conductive material. The concave part formed by the thin plate forming part on the opposing surface of the mask (4) for mounting a conductive material includes a concave part (8a) in which an opening pattern (6) is formed, and a groove-shaped concave part (8b) extending from the concave part (8a).

[0029] Each opening pattern (6) is formed in a thin sheet forming portion. For example, a concave portion (8b) connects two concave portions (8a) in which the opening pattern (6) is formed. FIG. 3 shows a preferred example in which one opening pattern (6) is formed in one concave portion (8a) and all concave portions (8a) are connected by a concave portion (8b).

[0030] Next, with reference to FIGS. 9 to 12, a method for manufacturing a mask (4) for mounting a conductive material will be described. FIG. 9 is a flowchart showing an example of a method for manufacturing a mask (4) for mounting a conductive material in Embodiment 1. FIGS. 10 and 11 are drawings for explaining a method for manufacturing a mask (4) for mounting a conductive material.

[0031] First, in S101, a first process is performed to form a first resist (31) on a base material (30). In this embodiment, the resist is an example of a photosensitive material. In the first process, a conductive base material (30) is prepared as shown in FIG. 10 (a). Next, a layer-shaped resist is formed on the surface (30a) of the base material (30), and then exposure and development are performed. By doing so, a first resist (31) is formed on the surface (30a) of the base material (30) so as to encircle the area corresponding to the portion formed by the thin film forming part of the conductive material supply surface (4a). Hereinafter, the corresponding area on the surface (30a) is denoted as area F.

[0032] FIG. 12 is a drawing showing an example of a first resist (31) formed on a base material (30) in the first process. FIG. 12 is a drawing of the surface (30a) of the base material (30) viewed from above. As described above, in the example shown in the present embodiment, the portion formed by the thin sheet forming part of the conductive material supply surface (4a) is not divided into multiple parts but is continuous. Because of this, the first resist (31) is formed in an endless shape so that it can be drawn with a single stroke when viewed from above on the surface (30a). Each cross-section shown in FIG. 10 and FIG. 11 represents a cross-section corresponding to the G-G cross-section of FIG. 12. By performing the first process, the first resist (31) is formed on the surface (30a) of the base material (30) as shown in FIG. 10 (b).

[0033] After the first process, in S102, a second process is performed to perform primary plating on the surface (30a) of the base material (30). For the primary plating, for example, an electro-casting method or an electroless plating method is employed. By this, a plating layer is formed on the surface (30a), in the area surrounded by the first resist (31) and in the area other than the area. Below, the plating layer formed in the area surrounded by the first resist (31) is given the symbol J1. The plating layer formed in the area other than the area surrounded by the first resist (31) is given the symbol J2. By performing the second process, the base material (30) is plated, and as shown in FIG. 10 (c), a plating layer (J1) and a plating layer (J2) are formed on the surface (30a).

[0034] After the second process, in S103, a third process is performed to remove the first resist (31). In the third process, a stripping solution is used to remove the first resist (31). By this, the first resist (31) is removed from the base material (30) as shown in (d) of FIG. 10.

[0035] After the third process, in S104, a fourth process is performed to remove the plating formed in region F. That is, in the fourth process, the plating layer (J1) is removed from the base material (30). As a result, as shown in (e) of FIG. 10, a plating layer (J2) is left on the surface (30a) of the base material (30). The first plating layer (10) is the plating layer (J2) that is not removed from the base material (30) in the fourth process and remains on the surface (30a).

[0036] The order of the third and fourth processes may be reversed. For example, the fourth process may be performed immediately after the second process, and the third process may be performed after the fourth process.

[0037] After the third and fourth processes, in S105, a fifth process is performed to form a second resist (32) in region F of the base material (30). The second resist (32) is a resist corresponding to a plurality of through holes (7) included in each opening pattern (6). That is, the second resist (32) is provided at the location where the through holes (7) are formed. In the fifth process, after forming the resist in region F, exposure and development are performed. By doing so, as shown in FIG. 11 (a), the second resist (32) is formed on the surface (30a) of the base material (30).

[0038] After the fifth process, in S106, a sixth process is performed to perform secondary plating on the plating layer (J2) (first plating layer (10)) and region F of the base material (30). For the secondary plating, for example, an electroplating method or an electroless plating method is employed. By this, as shown in FIG. 11 (b), a plating layer is formed on the plating layer (J2) and region F. The plating layer formed in the sixth process is the second plating layer (20).

[0039] After the 6th process, in S107, a 7th process is performed to remove the second resist (32). In the 7th process, a stripping solution is used to remove the second resist (32). As the second resist (32) is removed, a hole is formed in the second plating layer (20), as shown in (c) of FIG. 11. The hole formed in the second plating layer (20) in the 7th process is a through hole (7).

[0040] Finally, in S108, an 8th process is performed to integrally separate the plating layer (J2) (the first plating layer (10)) and the second plating layer (20) from the base material (30). By doing this, a mask (4) for mounting a conductive material as shown in FIGS. 3 to 7 can be obtained. Additionally, by attaching the mask (4) for mounting a conductive material to the frame (2) through the mesh (3), a plate (1) as shown in FIGS. 1 and 2 is completed.

[0041] In the mask (4) for mounting a conductive material, the first plating layer (10) is formed so as to be continuous without being divided into multiple layers. Because of this, the bonding area between the first plating layer (10) and the second plating layer (20) can be large, thereby suppressing peeling of the first plating layer (10).

[0042] In the mask (4) for mounting a conductive material, it is preferable that the region formed by the thin sheet forming part among the conductive material supply surface (4a) is not divided into multiple parts but remains connected. This can be achieved by forming the first resist (31) in the first process such that the region F is not divided into multiple parts but remains connected. In this example, the plating film to be peeled off in the fourth process can be reduced to one, thereby minimizing the peeling process and improving work efficiency.

[0043] In the mask (4) for mounting a conductive material, it is preferable that a first plating layer (10) be present between each of two adjacent opening patterns (6) among the plurality of opening patterns (6) provided in the mask (4) for mounting a conductive material. Such a configuration can be realized by appropriately setting the formation position of the first resist (31) in the first process and the formation position of the second resist (32) in the fifth process. In this example, a thick portion with increased strength can be placed between each of the opening patterns (6).

[0044] Below, other functions that can be employed by the mask (4) for carrying a conductive material are described. The mask (4) for carrying a conductive material may, if possible, employ a combination of the multiple functions shown below.

[0045] FIG. 13 is a drawing showing another example of a mask (4) for mounting a conductive material. FIG. 13 is a drawing of the mask (4) for mounting a conductive material viewed from direction A of FIG. 2 and is a drawing corresponding to FIG. 4. The mask (4) for mounting a conductive material shown in FIG. 13 differs from the mask (4) for mounting a conductive material shown in FIG. 4 in that only one area formed by the thin plate forming part of the conductive material supply surface (4a) reaches the edge of the conductive material supply surface (4a). That is, in the example shown in FIG. 13, on the opposing surface side, one concave part (8b) reaches the edge of the opposing surface. In this example, when peeling off the plating layer (J1) in the fourth process, the plating layer (J1) can be peeled off collectively from a location not surrounded by the plating layer (J2), thereby improving work efficiency.

[0046] FIG. 14 is a drawing showing another example of a mask (4) for mounting a conductive material. FIG. 14 is a cross-sectional view corresponding to FIG. 6 and is an enlarged view of section D shown in FIG. 5. The mask (4) for mounting a conductive material shown in FIG. 14 is different from the mask (4) for mounting a conductive material shown in FIG. 6 in that it further comprises a protrusion (11). The protrusion (11) protrudes from the cross-section of the first plating layer (10) into the interior of the thin plate forming portion of the second plating layer (20). FIG. 14 shows an example in which the first plating layer (10) and the protrusion (11) are formed integrally.

[0047] FIG. 15 is a drawing for explaining the process of forming a protrusion (11). FIG. 15 (a) corresponds to FIG. 10 (c), and FIG. 15 (b) corresponds to FIG. 11 (c). When protruding a protrusion (11) from a cross-section of the first plating layer (10), for example, in the second process, a plating layer having a thickness greater than the thickness of the first resist (31) is formed. When the thickness of the plating on the base material (30) exceeds the thickness of the first resist (31), the plating also grows in the horizontal direction based on the portion exceeding the thickness of the first resist (31). By this, among the plating formed in the second process, the portion grown in the horizontal direction on the first resist (31) can be used as a protrusion (11).

[0048] In addition, in the sixth process, as shown in FIG. 15 (b), a secondary plating is performed so that the protruding part is completely covered. In this example, the protrusion (11) can be made hook-shaped, which further suppresses the peeling of the first plating layer (10) from the second plating layer (20). Also, the shape of the protrusion (11) is not limited to a spherical shape.

[0049] Industrial applicability

[0050] The mask according to the present disclosure can be applied for mounting a conductive material. Explanation of the symbols

[0051] 1: Plate 2: Frame 3: Mesh 4: Mask for mounting conductive material 4a: Conductive material supply surface 5: Substrate 6: Opening pattern 7: Penetrating hole 8a~8b: Recesses 10: First plating layer 10a: Surface 10b: Surface 11: Protrusion 20: Second plating layer 20a~20c: Surface 30: Base material 30a: Surface 31: First resist 32: Second register

Claims

Claim 1 A mask for mounting a conductive material, comprising a first plating layer formed continuously without being divided into multiple parts and having a flat first surface, and a second plating layer formed continuously without being divided into multiple parts and covering the first plating layer from the first surface side, wherein a flat conductive material supply surface to which a conductive material is supplied is formed by a thin plate forming part that does not overlap with the first plating layer among the first plating layer and the second plating layer, wherein the distance between the second surface of the thin plate forming part and the conductive material supply surface is smaller than the distance between the third surface of the thick plate forming part that overlaps with the first plating layer among the second plating layer and the conductive material supply surface, wherein the second surface and the third surface face in the same direction as the direction in which the first surface faces, wherein a plurality of opening patterns are formed in the thin plate forming part, and a plurality of through holes for passing a conductive material are included in each of the plurality of opening patterns. Claim 2 In claim 1, the area formed by the thin plate forming portion among the conductive material supply surface is a continuous conductive material mounting mask that is not divided into multiple parts. Claim 3 A mask for mounting a conductive material according to claim 2, wherein only one of the regions reaches the edge of the conductive material supply surface. Claim 4 A mask for mounting a conductive material according to any one of claims 1 to 3, wherein the first plating layer is present between each of two adjacent opening patterns among the plurality of opening patterns. Claim 5 A mask for mounting a conductive material according to any one of claims 1 to 3, further comprising a projection protruding from the cross-section of the first plating layer into the interior of the thin sheet forming portion. Claim 6 A method for manufacturing a mask for mounting a conductive material as described in claim 1, comprising: a first step of forming a first resist on a base material such that a region corresponding to a portion formed by the thin plate forming portion of the conductive material supply surface is formed by a line; a second step of plating on the base material after the first step; a third step of removing the first resist after the second step; a fourth step of leaving the first plating layer on the base material by peeling off the plating formed on the region after the second step; a fifth step of forming a second resist corresponding to the plurality of through holes on the region of the base material after the third step and the fourth step; and a sixth step of plating the first plating layer and the region of the base material and forming the second plating layer after the fifth step. Claim 7 A method for manufacturing a mask for mounting a conductive material according to claim 6, wherein in the first process, the first resist is formed such that the region is not divided into multiple parts but remains connected. Claim 8 A method for manufacturing a mask for mounting a conductive material according to claim 6 or claim 7, wherein the first resist is formed in the first process and the second resist is formed in the fifth process such that the first plating layer exists between each of two adjacent opening patterns among the plurality of opening patterns.

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