Method for manufacturing a mask for mounting balls, and method for manufacturing a wiring board.

Abstract

To provide a method for manufacturing a ball-mounting mask that minimizes damage when the ball is mounted. [Solution] The method for manufacturing a ball-mounting mask of the embodiment includes preparing a mask body 110 having a ball-mounting opening 111 and an alignment opening 112, and closing the alignment opening 112 by providing a sealing member 120 on one side of the mask body 110. The mask body 110 has a recess 110t on one side that includes the alignment opening 112 in a plan view and is larger than the alignment opening 112. Closing the alignment opening 112 includes attaching a light-transmitting sealing member 120 to the recess 110t.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a mask for mounting balls and a method for manufacturing a wiring board using the mask for mounting balls.

Background Art

[0002] Patent Document 1 discloses a method of mounting solder balls on a plurality of connection pads formed on the surface of a multilayer printed wiring board using a mask for mounting balls having a plurality of openings. An alignment camera provided on the side of the mask for mounting balls opposite to the multilayer printed wiring board recognizes an alignment mark on the surface of the multilayer printed wiring board through an alignment opening, thereby adjusting the relative position between the mask for mounting balls and the multilayer printed wiring board. Further, an alignment opening is closed with a light-transmissive seal member to prevent solder balls from accidentally falling into the alignment opening.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the mask for mounting balls used in the method of mounting solder balls disclosed in Patent Document 1, a seal member is attached to the surface of the mask body. Therefore, during a process such as dropping a solder ball into an opening for mounting balls, it is considered that problems such as the seal member being peeled off or damaged due to interference with external equipment are likely to occur.

Means for Solving the Problems

[0005] The present invention provides a method for manufacturing a ball-mounting mask, comprising: preparing a mask body having a ball-mounting opening and an alignment opening; and closing the alignment opening by providing a sealing member on one surface of the mask body. The mask body has a recess on one surface of the mask body, in plan view, which includes the alignment opening, and closing the alignment opening involves attaching a light-transmitting sealing member to the recess.

[0006] The present invention relates to a method for manufacturing a wiring board, which includes: preparing a board having a first surface on which a plurality of connection pads and alignment marks are formed; installing a ball mounting mask manufactured by the above-described manufacturing method on the first surface using the alignment openings and the alignment marks; and mounting a plurality of solder balls onto the connection pads by dropping them into the ball mounting openings.

[0007] According to the manufacturing method for ball mounting masks of the embodiment of the present invention, ball mounting masks that are less susceptible to damage during the manufacturing process of wiring boards can be manufactured. Furthermore, according to the manufacturing method for wiring boards of the embodiment of the present invention, a highly efficient method for manufacturing wiring boards can be realized. [Brief explanation of the drawing]

[0008] [Figure 1A] A cross-sectional view illustrating a method for manufacturing a wiring board according to one embodiment of the present invention. [Figure 1B] A top view illustrating a method for manufacturing a wiring board according to one embodiment of the present invention. [Figure 2] A cross-sectional view illustrating a method for manufacturing a wiring board according to another embodiment of the present invention. [Figure 3A] A magnified view of a section of the cross-sectional view shown in Figure 1A. [Figure 3B] A magnified view of a portion of the top view shown in Figure 1B. [Figure 4] A magnified view of a section of the cross-sectional diagram shown in Figure 2. [Figure 5A]A cross-sectional view showing a method for manufacturing a ball-mounting mask according to one embodiment of the present invention. [Figure 5B] A cross-sectional view showing a method for manufacturing a ball-mounted mask according to another embodiment of the present invention. [Figure 6A] A top view showing a manufacturing method for a ball-mounting mask according to one embodiment of the present invention. [Figure 6B] A cross-sectional view showing a method for manufacturing a ball-mounting mask according to one embodiment of the present invention. [Figure 7A] A top view showing a manufacturing method for a ball-mounting mask according to one embodiment of the present invention. [Figure 7B] A cross-sectional view showing a method for manufacturing a ball-mounting mask according to one embodiment of the present invention. [Figure 8A] A top view showing a manufacturing method for a ball-mounting mask according to one embodiment of the present invention. [Figure 8B] A cross-sectional view showing a method for manufacturing a ball-mounting mask according to one embodiment of the present invention. [Figure 9A] A top view showing a manufacturing method for a ball-mounting mask according to one embodiment of the present invention. [Figure 9B] A cross-sectional view showing a method for manufacturing a ball-mounting mask according to one embodiment of the present invention. [Figure 10A] A top view showing a manufacturing method for a ball-mounting mask according to one embodiment of the present invention. [Figure 10B] A cross-sectional view showing a method for manufacturing a ball-mounting mask according to one embodiment of the present invention. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. A method for manufacturing a wiring board, which is an embodiment of the present invention, will be described with reference to FIGS. 1A to 2. The method for manufacturing a wiring board according to the embodiment includes a method for mounting balls on a substrate by a so-called dispensing method. The dispensing method is a method of dropping (dispensing) balls containing a metal or the like having conductivity (for example, solder balls or balls plated with solder on metal balls) into the openings of a mask having openings formed in advance, onto the conductive connection pads provided on the surface of a substrate (for example, a printed wiring board).

[0010] In the ball mounting method illustrated in FIG. 1A, the ball SB is dropped onto the connection pad 11 formed on the surface of the substrate 10 through the ball mounting opening 111 formed in the ball mounting mask 100.

[0011] The substrate 10 is, for example, a multilayer printed wiring board in which a plurality of insulating layers and conductor layers are alternately laminated by a well-known build-up method. The conductor layer of the multilayer printed wiring board is formed using any material having appropriate conductivity, and the insulating layer can be formed using an insulating resin. The substrate 10 has a plurality of connection pads 11 on the outermost conductor layer 14 on one side in its thickness direction. A coating layer 13 is provided on the conductor layer 14 of the substrate 10. The connection pad 11 is exposed from the opening formed in the coating layer 13. The coating layer 13 can be a solder resist layer formed using a photosensitive resin. Further, alignment marks 12 are provided on the substrate 10 in a region where the connection pads 11 do not exist. There is no restriction on the number of alignment marks 12, but it is preferable to have as many as possible within a possible range. The larger the number of alignment marks 12, the more the positioning accuracy between the substrate 10 and the ball mounting mask 100 may be improved.

[0012] In addition, in FIG. 1A, the conductor layer and the insulating layer that constitute the substrate 10 in the base 10B which is the layer below the conductor layer 14 in the substrate 10 are omitted. The surface composed of the conductor layer 14 and the coating layer 13 of the substrate 10 is referred to as the first surface 10F in the following description. FIG. 1B shows a top view of the ball mounting mask 100 shown in FIG. 1A. The cross-section of the ball mounting mask 100 in FIG. 1A is the cross-section along the line A-A in FIG. 1B. In the ball mounting mask 100 or the mask body 110, the surface facing the substrate 10 is also called the "lower surface" or the "back surface", and the surface facing the opposite side of the surface facing the substrate 10 is also called the "upper surface" or the "front surface".

[0013] In the ball mounting method in the method for manufacturing a wiring substrate according to the embodiment, first, the ball mounting mask 100 is installed on the first surface 10F side where the conductor layer 14 of the prepared substrate 10 is provided. The ball mounting mask 100 installed on the substrate 10 has a mask body 110. A plurality of ball mounting openings 111 corresponding to the plurality of connection pads 11 of the substrate 10 are formed in the mask body 110. A recess 110t is provided in the mask body 110 at a position different from the ball mounting openings 111. An alignment opening 112 corresponding to the alignment mark 12 of the substrate 10 is formed in the recess 110t. The upper surface side of the alignment opening 112 is closed by a light-transmissive seal member 120. The recess 110t has a so-called "counterbore (or countersink)" shape and has a bottom surface at a position one step lower than the upper surface of the mask body 110 around the alignment opening 112. Also, in the state where the alignment opening 112 is closed, the depth of the recess 110t is set so that the upper surface of the seal member 120 does not become higher than the upper surface of the mask body 110, that is, so that it is arranged inside the upper surface of the mask body 110.

[0014] The thickness of the mask body 110 and the depth of the recess 110t are not particularly limited. For example, the thickness of the mask body 110 may be about 0.1 mm, and the depth of the recess 110t may be about 0.06 mm. Furthermore, the size of the recess 110t and the size of the alignment opening 112 as viewed from above are not particularly limited. For example, the recess 110t may have a diameter of about 10 mm, and the alignment opening 112 may have a diameter of about 3 mm. Note that "viewed from above" means viewing the substrate 10 and the ball mounting mask 100 with the ball mounting mask 100 installed, from a line of sight along the thickness direction.

[0015] The ball mounting mask 100 is installed on the substrate 10 such that, in a plan view, the ball mounting opening 111 and the connection pad 11 overlap. Specifically, the installation position of the ball mounting mask 100 is adjusted so that, in a plan view from the side on which the ball mounting mask 100 is installed, the portion of the connection pad 11 exposed from the covering layer 13 is exposed within the ball mounting opening 111 of the mask body 110.

[0016] As detailed below, when installing the ball mounting mask 100 onto the first surface 10F, the alignment marks 12 on the substrate 10 are utilized. In a plan view, the position between the substrate 10 and the ball mounting mask 100 is adjusted so that the alignment marks 12 are exposed within the alignment opening 112 formed in the mask body 110. The presence of the alignment opening 112 in the ball mounting mask 100 makes it possible to accurately position the alignment marks 12 at a desired location within the alignment opening 112 and to accurately adjust the relative position between the substrate 10 and the ball mounting mask 100.

[0017] Next, with the ball mounting mask 100 placed on the first surface 10F of the substrate 10, multiple balls SB are placed on the ball mounting mask 100. More balls SB than the number of ball mounting openings 111 of the ball mounting mask 100 are placed on the ball mounting mask 100. Then, the multiple balls SB on the ball mounting mask 100 are swept over the mask body 110 by appropriate means such as a squeegee or a brush.

[0018] In Figure 1A, the ball SB is swept over the ball mounting mask 100 in the direction of the arrow by the squeegee ST. As a result, the ball SB is dropped into the ball mounting opening 111 of the mask body 110 and placed on the connection pad 11 of the substrate 10. It is preferable that a viscous flux is applied to the surface of the connection pad 11 before the ball mounting mask 100 is placed on the first surface 10F.

[0019] In the ball mounting method for the manufacturing method of the wiring board of this embodiment, the substrate 10 has alignment marks 12, and the ball mounting mask 100 has alignment openings 112 corresponding to the alignment marks 12, thereby enabling more accurate alignment between the substrate 10 and the ball mounting mask 100. The alignment openings 112 are formed within a recess 110t formed on the upper surface of the mask body 110. That is, a recess 110t larger than the alignment opening 112 is formed on the upper surface of the mask body 110, the alignment opening 112 is formed within the recess 110t, and the alignment opening 112 is closed by a sealing member 120. Therefore, when placing balls SB on the ball mounting mask 100, and when sweeping the balls SB into the ball mounting openings 111, there is no risk of the balls SB falling into the alignment openings 112. This prevents unnecessary balls SB from being placed on the substrate 10. Furthermore, since the sealing member 120 is attached to the recess 110t, problems such as the sealing member 120 interfering with the equipment and peeling off during the ball SB drop-in process using equipment such as a squeegee can be avoided. In particular, if the sealing member 120 attached to the recess 110t is positioned inward from the upper surface of the mask body 110 and does not protrude above the upper surface of the mask body 110, problems such as the sealing member 120 peeling off can be avoided more reliably.

[0020] In the manufacturing method of the wiring board of this embodiment, the dimensions of the ball SB mounted on the substrate 10 are not particularly limited. Furthermore, the dimensions of the ball mounting opening 111 provided in the ball mounting mask 100 are only required to allow the ball SB to pass through and be placed on the connection pad 11, and its shape is not particularly limited. For example, specifically, the ball SB may have a diameter of about 40 to 100 μm. The size of the ball mounting opening 111 is also preferably such that it has a diameter of about 40 to 100 μm and has an appropriate margin so that the ball SB is smoothly dropped in.

[0021] The placement of the ball SB onto the connection pad 11 is completed when the ball SB is dropped into all the ball mounting openings 111 formed in the ball mounting mask 100. Any excess ball SB remaining on the ball mounting mask 100 is removed from the ball mounting mask 100.

[0022] Next, the ball mounting mask 100 is separated from the substrate 10. The balls SB mounted on the connection pads 11 of the substrate 10 are melted by a reflow process in which the substrate 10 is heated at a predetermined temperature for a predetermined time. The balls SB and the connection pads 11 are interfacially bonded, and a wiring board with the balls SB mounted is provided. Note that the reflow process may be performed with the ball mounting mask 100 still installed on the substrate 10.

[0023] Figure 2 shows a cross-sectional view of a ball mounting mask 100α and a substrate 10, corresponding to the ball mounting mask 100 shown in Figure 1A, for a method of manufacturing a wiring board, which is another embodiment of the present invention. In this figure, components that have the same structure and operation as those in Figure 1A are given the same numbers as in Figure 1A, and their descriptions are omitted. In this embodiment, the ball mounting mask 100α is further provided with a spacer member 130 on the lower surface of the mask body 110. That is, when the ball mounting mask 100α is installed on the substrate 10, the spacer member 130 is interposed between the mask body 110 and the substrate 10. This prevents the mask body 110 from directly contacting the substrate 10, and can avoid problems such as scratching or soiling the substrate 10. The constituent material of the spacer member 130 is not particularly limited, but resin is preferably used.

[0024] The thickness of the spacer member 130 is not particularly limited, but for example, it could be about 4 mm. Similarly, the size of the opening provided in the spacer member 130 corresponding to the alignment opening 112 is not particularly limited, but for example, if the alignment opening 112 is about 3 mm in diameter, the opening could have a diameter of about 4 mm.

[0025] The detailed configuration of the ball mounting mask 100, the method for adjusting the position between the substrate 10 and the ball mounting mask 100, and the method for placing the balls SB in the ball mounting method of the manufacturing method of the wiring board shown in Figures 1A and 1B will be described in detail with reference to Figures 3A and 3B. Figure 3A shows an enlarged view of region II near the alignment mark 12 and alignment opening 112, which is enclosed by a dashed line in the cross-sectional view of Figure 1A. Figure 3B shows a top view of the region shown in Figure 3A. Figure 3B shows the positional relationship of the peripheral edge 110op of the recess 110t of the mask body 110, the outer peripheral edge 120op of the sealing member 120, the inner peripheral edge 121op and outer peripheral edge 122op of the adhesive layer 121, the peripheral edge 112op of the alignment opening 112, and the outer peripheral edge 12op of the alignment mark 12 in a plan view. In Figure 3B, the periphery 110op of the recess 110t of the mask body 110 and the outer peripheral edge 120op of the sealing member 120 are shown as solid lines, the inner peripheral edge 121op and outer peripheral edge 122op of the adhesive layer 121 are shown as dashed lines, the periphery 112op of the alignment opening 112 is shown as a dashed line, and the outer peripheral edge 12op of the alignment mark 12 is shown as a dashed line.

[0026] In the ball mounting method of the wiring board manufacturing method of the embodiment, the alignment marks 12 on the substrate 10 are recognized by the alignment camera AC when adjusting the relative position between the substrate 10 and the ball mounting mask 100. The relative position between the substrate 10 and the ball mounting mask 100 is adjusted by adjusting the recognized alignment marks 12 to a predetermined position within the alignment opening 112.

[0027] In the illustrated example, the alignment mark 12 has a circular planar shape. The alignment mark 12 is recognized by the alignment camera AC, and the center position of the alignment mark 12 is calculated. A correction amount is calculated to match the center position of the alignment aperture 112 with the center position of the alignment mark 12, and the relative positions of the substrate 10 and the ball mounting mask 100 can be adjusted according to this correction amount.

[0028] In the ball mounting method included in the manufacturing method of the wiring board of the embodiment, the alignment opening 112 formed in the mask body 110 is closed by a light-transmitting sealing member 120. The alignment camera AC recognizes the alignment mark 12 when transmitted light passing through the sealing member 120 is input. Therefore, it is desirable that the sealing member 120 has good light transmittance (for example, high transmittance of visible light). Furthermore, it is preferable that the surface of the sealing member 120 is formed to be relatively flat so that light scattering does not easily occur on the surface.

[0029] As described above, the depth Dp of the recess 110t formed on the upper surface of the mask body 110 is set so that the upper surface of the sealing member 120 that closes the alignment opening 112 does not protrude above the upper surface of the mask body 110. However, if Dp is large, in the manufacturing process of the wiring board, when the ball SB is placed on the ball mounting mask 100 and dropped into the ball mounting opening 111, the ball SB may remain on the sealing member 120 in the recess 110t. The ball SB remaining in the recess 110t may appear in the image data acquired by the alignment camera AC during the alignment process between the substrate 10 and the ball mounting mask 100, which may cause problems such as inability to align or large adjustment errors.

[0030] Therefore, it is preferable that the depth Dp of the recess 110t is smaller than the radius Db of the ball mounting opening 111 (see Figure 2). This prevents the ball SB from remaining in the recess 110t during the ball SB insertion process, which can prevent adjustment errors during the alignment of the substrate 10 and the ball mounting mask 100.

[0031] More preferably, the depth Dp of the recess 110t is smaller than the sum of the thickness Tc of the sealing member 120, the thickness Ta of the adhesive layer 121, and the radius Db of the ball mounting opening 11 (see Figure 2). This allows for accurate alignment of the substrate 10 and the ball mounting mask 100, even when the thicknesses of the sealing member 120 and the adhesive layer 121 are not negligible.

[0032] In this embodiment, an alignment opening 112 is formed in a recess 110t formed on the upper surface of the mask body 110, and the alignment opening 112 is closed by a sealing member 120. For this reason, the sealing member 120 is large enough to close the alignment opening 112, and at the same time, it is smaller than the recess 110t so that the sealing member 120 fits into the recess 110t. As a result, a gap may exist between the periphery 110op of the recess 110t and the outer peripheral edge 120op of the sealing member 120. If the gap between the periphery 110op of the recess 110t and the outer peripheral edge 120op of the sealing member 120 is large, the ball SB may remain in the recess 110t during the ball dropping process, which may cause problems such as adjustment errors during alignment between the substrate 10 and the ball mounting mask 100 using an alignment camera.

[0033] It is preferable that the size G of the gap between the periphery 110op of the recess 110t and the outer peripheral edge 120op of the sealing member 120, that is, the distance between the outer peripheral edge 120op of the sealing member 120 and the periphery 110op of the recess 110t, is smaller than the radius Db of the ball mounting opening 111 all around. As shown in Figure 3B, if both the recess 110t and the sealing member 120 are circular, the gap G is represented by the difference in radii between the recess 110t and the sealing member 120. When the gap G is smaller than the radius Db of the ball mounting opening 111, in the ball dropping process, the ball SB may not be left between the periphery 110op of the recess 110t and the outer peripheral edge 120op of the sealing member 120, and the alignment between the substrate 10 and the ball mounting mask 100 may be performed with high accuracy.

[0034] As shown in Figure 3A, the adhesive layer 121 is interposed between the sealing member 120 and the mask body 110 in the region between the solid line 120op indicating the outer edge of the sealing member 120 and the dashed line 112op indicating the periphery of the alignment opening 112. If the adhesive layer 121 extends into the region inside the alignment opening 112, dirt is likely to adhere to the adhesive layer 121 exposed within the alignment opening 112. In particular, when a reflow process is performed to bond the ball SB to the connection pad 11 while the ball mounting mask 100 is installed on the substrate 10, components contained in the flux that may also be applied to the surface of the alignment mark 12 may volatilize and adhere to the adhesive layer 121.

[0035] If there is dirt on the sealing member 120 or adhesive layer 121 within the alignment opening 112, light transmission will be obstructed, which may cause misrecognition of the alignment marks 12 and the alignment opening 112 by the alignment camera AC. Misrecognition of the alignment marks 12 and the alignment opening 112 may cause poor positioning between the substrate 10 and the ball mounting mask 100. Poor positioning between the substrate 10 and the ball mounting mask 100 may cause misalignment of the ball mounting opening 111 relative to the connection pad 11. As a result, a problem may occur in which the ball SB is not accurately mounted on the connection pad 11. For this reason, it is desirable that the sealing member 120 is free from dirt such as foreign matter.

[0036] In this embodiment, as shown in Figure 3B, the adhesive layer 121 is positioned outside the alignment opening 112 in a plan view so that it is not exposed inside the alignment opening 112. Specifically, the adhesive layer 121 has an opening larger than the alignment opening 112, which is defined by the inner peripheral edge 121op. That is, in a plan view, the adhesive layer 121 is positioned so that the alignment opening 112 fits within the opening defined by the inner peripheral edge 121op. Therefore, there is little risk of foreign matter adhering to the area inside the peripheral edge 112op of the alignment opening 112. In the illustrated example, the alignment opening 112 has a circular planar shape, and the opening 121op provided in the adhesive layer 121 is formed in substantially the same shape. In a plan view, the shortest distance between the peripheral edge 112op of the alignment opening 112 and the inner peripheral edge 121op of the adhesive layer 121 is preferably 500 μm or more, from the viewpoint of preventing foreign matter and other contaminants that may adhere to the adhesive layer 121 from being exposed inside the alignment opening 112. By configuring the adhesive layer 121 so that it is not exposed inside the alignment opening 112, highly accurate alignment adjustment between the substrate 10 and the ball mounting mask 100 can be achieved. Furthermore, a method for manufacturing a wiring board is provided, including a ball mounting method that enables more accurate mounting of balls SB on the connection pad 11.

[0037] The thickness Ta of the adhesive layer 121 provided between the sealing member 120 and the mask body 110 is preferably smaller than the radius Db of the ball mounting opening 111. For example, the thickness Ta of the adhesive layer 121 is preferably 15 μm or less. When the thickness Ta of the adhesive layer 121 is smaller than the radius Db of the ball mounting opening 111, the risk of the ball SB on the ball mounting mask 100 coming into contact with the side surface of the adhesive layer 121 can be reduced. This prevents components of the adhesive layer 121 from adhering to the ball SB, thereby enabling better ball mounting. From a similar viewpoint, it may be preferable that, in a plan view, the outer peripheral edge 122op of the adhesive layer 121 is located inside the outer peripheral edge 120op of the sealing member 120.

[0038] The detailed configuration of the ball mounting mask 100α and the method for adjusting the position of the substrate 10 and the ball mounting mask 100α in the ball mounting method of the manufacturing method of the wiring board shown in Figure 2 will be described in detail with reference to Figure 4. Figure 4 shows an enlarged view of the region III near the alignment mark 12 and alignment opening 112, which is enclosed by a dashed line in the cross-sectional view of Figure 2. In this figure, components that have the same structure and operation as those in Figure 3A are given the same numbers as in Figure 3A and their descriptions are omitted. In this embodiment, as shown in Figure 2, the ball mounting mask 100 is further provided with a spacer member 130 on the lower surface of the mask body 110. That is, when the ball mounting mask 100 is installed on the substrate 10, the spacer member 130 is interposed between the mask body 110 and the substrate 10. This prevents the mask body 110 from directly contacting the substrate 10, and can avoid problems such as scratching or soiling the substrate 10. The material used for the spacer member 130 is not particularly limited, but resin is preferably used.

[0039] Next, a method for manufacturing a ball-mounting mask, which is one embodiment of the present invention, will be described with reference to Figures 5A to 10B. In the method for manufacturing the ball-mounting mask 100 of this embodiment, a mask body 110 having a ball-mounting opening 111 and an alignment opening 112 is prepared. The alignment opening 112 of the mask body 110 is closed by attaching a light-transmitting sealing member 120 to one side of the mask body 110 via an adhesive layer 121. The method for manufacturing the ball-mounting mask 100 will be described in detail below.

[0040] As shown in Figure 5A, the ball mounting mask 100 is formed by closing one of the alignment openings 112 of the mask body 110 by attaching a sealing member 120 with an adhesive layer 121 interposed therebetween. The mask body 110 may be made of a metal plate, such as stainless steel, copper alloy, or nickel alloy. To form the ball mounting openings 111 and alignment openings 112 on the plate, the formation of a resist with openings on the surface of the plate and etching to remove the plate exposed in the openings may be used. Laser processing or drilling may also be used to form the ball mounting openings 111 and alignment openings 112 on the plate.

[0041] Similarly, in the manufacturing of the ball-mounting mask 100α equipped with the spacer member 130, as described with reference to Figures 2 and 4, the alignment opening 112 of the mask body 110 is closed by the sealing member 120, as shown in Figure 5B. That is, the ball-mounting mask 100α is formed by closing one side of the alignment opening 112 of the mask body 110 by attaching a sealing member 120 with an adhesive layer 121 interposed therebetween. In Figure 5B, the spacer member 130 is attached to the mask body 110 beforehand, and then the sealing member 120 is attached. However, the method is not limited to this, and the spacer member 130 may be attached to the mask body 110 after the sealing member 120 has been attached.

[0042] The procedure for forming the sealing member 120 and adhesive layer 121 attached to the mask body 110 will be described below with reference to Figures 6A to 10B. First, as shown in the top view of Figure 6A and the cross-sectional view of Figure 6B, a sheet SE is prepared, consisting of a base material BS, an adhesive layer 121 provided on one side of the base material BS, and a cover film 122 that is bonded to the side of the adhesive layer 121 opposite to the side where the base material BS is provided. It is preferable that a light-transmitting acrylic adhesive is used for the adhesive layer 121, and it is even more preferable that the adhesive layer 121 has good non-discoloration properties.

[0043] Next, as shown in Figures 7A and 7B, an opening OP is formed in the sheet SE. The opening OP is formed to a size that can accommodate the alignment opening 112 formed in the mask body 110 inside it. The shape of the opening OP may be formed to be substantially the same as the periphery 112op of the alignment opening 112. In the illustrated example, the alignment opening 112 has a circular planar shape, and the opening OP formed in the sheet SE is also formed to be circular. The portion of the adhesive layer 121 corresponding to the opening OP corresponds to the inner periphery 121op of the adhesive layer 121 in the ball mounting mask 100. When the alignment opening 112 and the opening OP are circular, the radius of the opening OP may be formed to be at least 500 μm larger than the radius of the alignment opening 112.

[0044] Next, as shown in Figures 8A and 8B, the substrate BS is peeled off and removed from the adhesive layer 121. This exposes the side of the adhesive layer 121 opposite to the cover film 122.

[0045] Next, as shown in Figures 9A and 9B, a sealing member 120 is attached to the side of the adhesive layer 121 from which the base material BS has been peeled off (the side opposite to the cover film 122). The sealing member 120 closes one side of the opening OP. The sealing member 120 is made of a material with excellent light transmittance, such as a transparent synthetic resin base material like polyester or polyethylene terephthalate. The base material BS that has been peeled off and removed from the adhesive layer 121 may be reattached as a sealing member 120. In this case, the transparent synthetic resin base material mentioned above is used for the base material BS, and the portion of the base material BS that does not have an opening OP is reattached so as to close the inner peripheral edge 121op of the adhesive layer 121. This can reduce the manufacturing cost of the ball mounting mask 100.

[0046] Next, as shown in Figures 10A and 10B, the sealing member 120, adhesive layer 121, and cover film 122 are cut out and extracted in the shape that the sealing member 120 should have, that is, along the outer peripheral edge 120op of the sealing member 120. The sheet in which the sealing member 120, adhesive layer 121, and cover film 122 are laminated can be cut out into any shape. In the illustrated example, an example is shown in which the sheet is cut out along the circular outer peripheral edge 120op concentric with the inner peripheral edge 121op of the adhesive layer 121.

[0047] Next, the cover film 122 is peeled off the adhesive layer 121. As shown in Figure 5A or Figure 5B, the side of the adhesive layer 121 opposite to the sealing member 120 that is exposed by the peeling off of the cover film 122 is attached to the mask body 110. That is, the sealing member 120 is attached to the mask body 110 via the adhesive layer 121. The sealing member 120 and the adhesive layer 121 can be attached integrally to the mask body 110. As a result, the alignment opening 112 of the mask body 110 is closed by the sealing member 120, and the manufacturing of the ball-mounting mask 100 is completed.

[0048] When attaching the sealing member 120 to the mask body 110, the alignment opening 112 can be positioned so that it fits within the inner peripheral edge 121op of the adhesive layer 121. In other words, the adhesive layer 121 can be positioned so that it is not exposed within the alignment opening 112. When the sealing member 120 is attached to the mask body 110, the distance between the inner peripheral edge 121op of the adhesive layer 121 and the peripheral edge 112op of the alignment opening 112 can be set to be 500 μm or more.

[0049] As an example, the planar shape of the alignment opening 112 and the planar shape of the inner peripheral edge 121op of the adhesive layer 121 are approximately the same circular shape. When the alignment opening 112 and the inner peripheral edge 121op of the adhesive layer 121 are approximately the same shape, it is easy to adjust the relative positions of the alignment opening 112 and the inner peripheral edge 121op, and it may be easier to fit the alignment opening 112 within the inner peripheral edge 121op. This can suppress the occurrence of a state in which the adhesive layer 121 is exposed inside the alignment opening 112.

[0050] The thickness Ta of the adhesive layer 121 may be formed to be smaller than the radius of the ball mounting opening 111 in order to suppress ball mounting defects in the ball mounting method described above. Furthermore, the adhesive layer 121 may be formed such that its outer peripheral edge 122op is located inside the outer peripheral edge 120op of the sealing member 120. In this case, after the steps shown in Figures 10A and 10B, the portion of the cover film 122 and the adhesive layer 121 near the outer peripheral edge can be removed by cutting from the cover film 122 side.

[0051] The manufacturing method of the wiring board in the embodiment is not limited to the method described with reference to the drawings. In the ball mounting method, a method that does not involve mechanical contact with the ball, such as blowing gas, may be used to drop the ball into the ball mounting opening. Furthermore, the ball mounting mask used may have multiple ball mounting openings of different sizes, and balls of different dimensions may be mounted on the substrate using this ball mounting mask.

[0052] Furthermore, the method for manufacturing the ball-carrying mask of the embodiment is not limited to the method described above with reference to the drawings, and the structure of the manufactured ball-carrying mask is not limited to the structure exemplified in the drawings, nor to the structure, shape, and materials exemplified in this specification. For example, the plate-like body used for the mask body may be formed by laminating multiple plate-like bodies. In addition, the surface of the sealing member may be treated with an antistatic coating, such as an antistatic agent, to prevent the adhesion of foreign matter. The conditions and sequence of the manufacturing method described above can be changed as appropriate. Depending on the structure of the ball-carrying mask actually manufactured, some steps may be omitted, and other steps may be added. [Explanation of Symbols]

[0053] 10 circuit boards 11 connection pads 12 Alignment Marks 13 Covering layer 14 Conductor layer 10F 1st page Mask for mounting 100 balls 110 Mask body 110t recess 111 Ball mounting opening 112 Alignment opening 120 sealing member 121 Adhesive layer 122 Cover film 130 Spacer member OP opening BS base material ST Squeegee AC Alignment Camera SB Ball

Claims

1. A method for manufacturing a ball-mounting mask, comprising: preparing a mask body having a ball mounting opening and an alignment opening; and closing the alignment opening by providing a sealing member on one side of the mask body, The mask body has a recess on one of its surfaces, which, in plan view, includes the alignment opening. Closing the alignment opening includes attaching a light-transmitting sealing member to the recess.

2. A manufacturing method according to claim 1, The sealing member is attached to the recess such that the entire sealing member is positioned inward from one of the surfaces of the mask body.

3. A manufacturing method according to claim 2, The sealing member has substantially the same shape as the recess and is smaller than the recess.

4. The manufacturing method according to claim 2 The sealing member has substantially the same shape as the alignment opening and is larger than the alignment opening.

5. A manufacturing method according to claim 2, The depth of the recess is smaller than the radius of the opening for mounting the ball.

6. A manufacturing method according to claim 2, Closing the alignment opening involves interposing an adhesive layer having an opening larger than the alignment opening between the sealing member and the mask body such that, in a plan view, the alignment opening is contained within the opening of the adhesive layer.

7. A manufacturing method according to claim 6, The opening in the adhesive layer is substantially the same shape as the alignment opening.

8. A manufacturing method according to claim 6, The adhesive layer is provided such that the periphery of the opening in the adhesive layer and the periphery of the alignment opening are separated by 500 μm or more.

9. A manufacturing method according to claim 6, The sealing member and the adhesive layer, which adhere to each other, are integrally attached to the mask body.

10. A manufacturing method according to claim 1, The invention further includes attaching a spacer member having an opening larger than the alignment opening to the other surface of the mask body opposite to one surface, such that, in a plan view, the alignment opening is contained within the opening of the spacer member.

11. A substrate is prepared having a first surface on which multiple connection pads and alignment marks are formed, On the first surface, a ball mounting mask manufactured by the manufacturing method described in any one of claims 1 to 10 is installed using the alignment opening and the alignment marks. By dropping multiple balls into the ball mounting opening, the balls are mounted on the connecting pad. A method for manufacturing a wiring board, including the method described above.

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