Metal mask and method for mounting component

Abstract

To provide a metal mask and a mounting method of a mounting component capable of suppressing deterioration in bonding strength of an electrode of the mounting component to a pad while suppressing occurrence of a failure due to solder paste protruding from the pad.SOLUTION: In the mask body 4 of the metal mask, a plurality of openings 41 are formed corresponding to the plurality of pads 22 fixed to the mounting surface 21 of the substrate 2. The mask body 4 limits the region in which the solder paste 5 is printed on the mounting surface 21 and the pads 22 to the region of the openings 41. The area of each opening 41 is greater than or equal to the area of the corresponding pad 22. When the mask body 4 is placed in the masking position, the position of each opening 41 is shifted outward from the corresponding pad 22 with respect to the body space. A part of the pad 22 becomes a pad margin 22a deviated from a range where the opening 41 overlaps.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a metal mask and a method for mounting a mounting component. [Background technology]

[0002] Patent Document 1 discloses a method for mounting chip components on a substrate, in which solder paste is printed on the pads of the substrate, the chip components are then placed on the substrate, and the solder paste is heated by reflow to solder the electrodes of the chip components to the pads. The solder paste is printed on the pads by overlaying a metal mask, with openings formed to match the positions of the pads, on the substrate. The openings formed in the metal mask are smaller than the pads. This makes it difficult for the solder paste to overflow from the pads, thereby preventing defects such as the formation of solder balls and solder bridges between the electrodes of the chip components. In other words, defects caused by solder paste overflowing from the pads are prevented. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-98074 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when using the conventional metal mask disclosed in Patent Document 1, the openings are smaller than the pads, which reduces the amount of solder paste printed on the pads, thereby reducing the bonding strength of the electrodes of the chip components to the pads.

[0005] The present disclosure is intended to solve the above-mentioned problems, and aims to provide a metal mask and a method for mounting a mounted component that can suppress the occurrence of defects caused by solder paste overflowing from the pad while suppressing a decrease in the bonding strength of the electrode of the mounted component to the pad. [Means for solving the problem]

[0006] The metal mask according to the present disclosure has a plurality of openings formed therein corresponding to a plurality of pads fixed to the mounting surface of the substrate, and includes a mask body that is arranged at a mask position that covers the mounting surface to which the plurality of pads are fixed. The mask body has solder paste filled into each opening for individually joining a plurality of electrodes provided on the component body of the mounting component to the plurality of pads, thereby restricting the area in which the solder paste is printed on the mounting surface and each pad to the area of ​​each opening, the area of ​​each opening being equal to or greater than the area of ​​the corresponding pad, and the position of each opening being shifted outward from the corresponding pad with respect to the body space, which is the placement space for the component body, due to the position of the opening being shifted from the pad, and part of the pad becomes a pad margin that is outside the range where the openings overlap. A mounting method for a mounting component according to the present disclosure is a method for mounting a mounting component on a substrate by individually bonding a plurality of electrodes provided on a component body of the mounting component to a plurality of pads fixed to the mounting surface of the substrate, the method including: a mask placement step of placing a mask body having a plurality of openings formed therein corresponding to the plurality of pads at a mask position covering the mounting surface to which the plurality of pads are fixed; a printing step of printing solder paste on the mounting surface and each pad by filling each opening with solder paste for individually bonding the plurality of electrodes to the plurality of pads; and a printing step of removing the mask body from the mask position after the printing step, so that the solder paste in each opening is printed on a plurality of paste forming portions. the area of ​​each opening is equal to or greater than the area of ​​the corresponding pad, and by placing the mask body at the mask position in the mask placement step, the position of each opening is shifted outward from the corresponding pad with respect to the main body space, and part of the pad becomes a pad margin outside the overlapping range of the openings due to the position of the opening being shifted from the pad. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to suppress the occurrence of problems caused by solder paste spilling out from the pad, while suppressing a decrease in the bonding strength between the electrode of the mounting component and the pad. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a top view showing a state in which components are mounted on a substrate according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] 2 is a flowchart showing a method for mounting components on the mounting surface of the substrate in FIG. [Figure 4] 4 is a top view showing a state in which a mask body of a metal mask used in the mask placement step of FIG. 3 is placed on a substrate. FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along line VV in FIG. [Figure 6] 5 is a top view showing a state in which each opening in FIG. 4 is filled with solder paste. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] 7 is a top view showing a state in which a mounted component is placed on a board in which the mask body of FIG. 6 has been moved out of the mask position. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 8. [Figure 10] 9 is a top view showing a state in which each electrode of FIG. 8 is placed on each paste forming portion. [Figure 11] FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. [Figure 12] FIG. 10 is a top view showing a state in which the mask body of the metal mask according to the second embodiment is placed at a mask position relative to the substrate, and each opening is filled with solder paste. [Figure 13] FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 12. [Figure 14] 13 is a top view showing a state in which a mounting component is placed on the mounting surface of the substrate after the mask body of FIG. 12 has been removed from the mask position. [Figure 15] FIG. 15 is a cross-sectional view taken along line XV-XV in FIG. [Figure 16] FIG. 11 is a top view showing a state in which components are mounted on a substrate according to a third embodiment. [Figure 17] 17 is a front view showing the mounted components and the board as viewed along the arrow XVII in FIG. 16. [Figure 18] FIG. 11 is a top view showing a state in which a mask body of a metal mask used in a mask placement step according to the third embodiment is placed on a substrate. [Figure 19] FIG. 19 is a cross-sectional view taken along line XIX-XIX in FIG. 18. [Figure 20] 19 is a top view showing a state in which each opening in FIG. 18 is filled with solder paste. [Figure 21] FIG. 21 is a cross-sectional view taken along line XXI-XXI in FIG. 20. [Figure 22] 21 is a top view showing a state in which mounting components are arranged on the mounting surface of the substrate after the mask body of FIG. 20 has been removed from the mask position. [Figure 23] 23 is a front view showing the mounted components and the board as viewed along the arrow XXIII in FIG. 22. [Figure 24] FIG. 10 is a top view showing a state in which components are mounted on a substrate according to a fourth embodiment. [Figure 25] 25 is a front view showing the mounted components and the board as viewed along the arrow XXV in FIG. 24. [Figure 26] FIG. 10 is a top view showing a state in which a mask body of a metal mask used in a mask placement step according to the fourth embodiment is placed on a substrate. [Figure 27] FIG. 20 is a cross-sectional view taken along line XXVII-XXVII in FIG. 19. [Figure 28] 27 is a top view showing a state in which each opening in FIG. 26 is filled with solder paste. [Figure 29] FIG. 29 is a cross-sectional view taken along line XXIX-XXIX in FIG. 28. [Figure 30] 29 is a top view showing a state in which mounting components are arranged on the mounting surface of the substrate with the mask body of FIG. 28 removed from the mask position. [Figure 31] 31 is a front view showing the mounted components and the board as seen along the arrow XXXI in FIG. 30. [Figure 32] 13 is a top view showing a state in which a mounting component is placed on a mounting surface of a substrate in a modified example of the mounting method for a mounting component according to the fourth embodiment. FIG. [Figure 33] FIG. 11 is a top view showing a state in which a mounting component is placed on a mounting surface of a substrate in another modified example of the mounting method for a mounting component according to the fourth embodiment. [Figure 34]FIG. 13 is a top view showing a state in which a mask body of a metal mask used in a mask placement step according to the fifth embodiment is placed on a substrate. [Figure 35] 35 is a top view showing a state in which components are placed on a board in which the mask body has been removed from the mask position, leaving the solder paste filled in each opening of FIG. 34. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes embodiments of the subject matter of the present disclosure with reference to the accompanying drawings. In each drawing, identical or corresponding parts are designated by the same reference numerals, and redundant explanations are appropriately simplified or omitted. Note that the subject matter of the present disclosure is not limited to the following embodiments, and any component of the embodiments may be modified or omitted within the scope of the gist of the present disclosure.

[0010] Embodiment 1 Fig. 1 is a top view showing a state in which a mounting component is mounted on a substrate according to embodiment 1. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. The mounting component 1 has a component body 11 and a plurality of electrodes 12.

[0011] A plurality of electrodes 12 are provided on the component body 11. In this embodiment, two electrodes 12 are provided on the component body 11. A first component reference direction and a second component reference direction that are orthogonal to each other are set on the component body 11. One electrode 12 is provided on each end of the component body 11 in the first component reference direction.

[0012] The substrate 2 has a mounting surface 21 formed thereon. A plurality of pads 22 corresponding to the plurality of electrodes 12 are fixed to the mounting surface 21 of the substrate 2. The position of each pad 22 on the mounting surface 21 is set to match the position of each electrode 12 on the mounting component 1.

[0013] In this embodiment, two pads 22 corresponding to the two electrodes 12 are fixed to the mounting surface 21. A first mounting surface reference direction x and a second mounting surface reference direction y that are perpendicular to each other are set along the mounting surface 21. The two pads 22 are arranged on the mounting surface 21 with a gap between them in the first mounting surface reference direction x. Each pad 22 has a rectangular shape.

[0014] A body space, which is a placement space for the component body 11, is defined on the mounting surface 21. The body space is defined between two pads 22. The component body 11 is placed in the body space with the component first reference direction of the component body 11 aligned with the mounting surface first reference direction x and with the component second reference direction aligned with the mounting surface second reference direction.

[0015] When the mounting component 1 is viewed in a direction perpendicular to the mounting surface 21, each electrode 12 overlaps a corresponding pad 22. Each electrode 12 is joined to a corresponding pad 22 via a solder joint 3. The mounting component 1 is mounted on the mounting surface 21 of the substrate 2 with each electrode 12 joined to each pad 22.

[0016] Next, a mounting method for mounting the mounting component 1 on the mounting surface 21 of the substrate 2 will be described. Fig. 3 is a flowchart showing the mounting method for mounting the mounting component 1 on the substrate 2 of Fig. 1. The mounting method for mounting the mounting component includes a mask placement step S1, a printing step S2, a mask removal step S3, a mounting component placement step S4, and a bonding step S5. When mounting the mounting component 1 on the mounting surface 21 of the substrate 2, the mask placement step S1, printing step S2, mask removal step S3, mounting component placement step S4, and bonding step S5 are carried out in this order.

[0017] <Mask placement process S1> In the mask placement step S1, a metal mask is used. The metal mask has a mask body. In the mask placement step S1, the mask body of the metal mask is placed on the substrate 2.

[0018] Fig. 4 is a top view showing a state in which the mask body of the metal mask used in the mask placement step S1 of Fig. 3 is placed on the substrate 2. Fig. 5 is a cross-sectional view taken along line VV of Fig. 4. In the mask placement step S1, the mask body 4 is placed at a mask position that covers the mounting surface 21 to which the multiple pads 22 are fixed.

[0019] The mask body 4 is a flat metal plate. In this embodiment, the thickness t1 of the mask body 4 is 100 μm or more and 150 μm or less. A plurality of openings 41 are formed in the mask body 4 corresponding to a plurality of pads 22. In this embodiment, two openings 41 are formed corresponding to two pads 22. The area of ​​each opening 41 is equal to or greater than the area of ​​the corresponding pad 22. In this embodiment, the area of ​​each opening 41 is the same as the area of ​​each pad 22. In this embodiment, the shape of each opening 41 is the same as the shape of each pad 22. Therefore, in this embodiment, the shape of each opening 41 and each pad 22 is rectangular.

[0020] The positional relationship of the multiple openings 41 formed in the mask body 4 corresponds to the positional relationship of the multiple pads 22 fixed to the mounting surface 21. As a result, when the mask body 4 is placed at the mask position, each opening 41 overlaps with a corresponding pad 22.

[0021] A first mask reference direction and a second mask reference direction that are perpendicular to each other are set along the mask body 4. The two openings 41 are formed in the mask body 4 at an interval from each other in the first mask reference direction. The mask body 4 is placed at the mask position such that the first mask reference direction coincides with the first mounting surface reference direction x of the mounting surface 21 and the second mask reference direction coincides with the second mounting surface reference direction y of the mounting surface 21.

[0022] When the mask body 4 is placed at the mask position, the position of each opening 41 is shifted outward from the corresponding pad 22 with respect to the body space of the component body 11. A part of the pad 22 becomes a pad margin 22a outside the overlapping range of the opening 41 due to the position of the opening 41 being shifted from the pad 22.

[0023] In this embodiment, the distance between two openings 41 in the first mask reference direction, i.e., the inter-opening first direction distance d1, is greater than the distance between two pads 22 in the first mounting surface reference direction x, i.e., the inter-pad first direction distance d2. As a result, when the mask body 4 is placed at the mask position, the position of each opening 41 is shifted outward from the corresponding pad 22 with respect to the main body space. Therefore, the direction in which the openings 41 are shifted outward from the pads 22 with respect to the main body space in the mask placement step S1 is the first mounting surface reference direction x. In this embodiment, the portion of each pad 22 closer to the main body space than the openings 41 becomes the pad margin 22a.

[0024] When the mask body 4 is placed at the mask position, the area of ​​each opening 41 that overlaps with the corresponding pad 22 is an overlapping area 41a, and the area that extends beyond the corresponding pad 22 is a detached area 41b. In the mask placement step S1, the area of ​​the opening 41 that overlaps with the pad 22, i.e., the area of ​​the overlapping area 41a, is at least one-third of the area of ​​the opening 41. In addition, in the mask placement step S1, the area of ​​the opening 41 that extends beyond the pad 22, i.e., the detached area 41b, is at most three-quarters of the area of ​​the corresponding pad 22.

[0025] <Printing process S2> After the mask placement step S1, the printing step S2 is performed. In the printing step S2, the solder paste is filled into each opening 41, thereby printing the solder paste onto the mounting surface 21 and each pad 22.

[0026] FIG. 6 is a top view showing the state in which each opening 41 of FIG. 4 has been filled with solder paste. FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 6. In the printing step S2, the solder paste 5 is filled into each opening 41 by sliding a squeegee (not shown) over the top surface of the mask body 4. As a result, the solder paste 5 is filled not only in the overlapping region 41a but also in the offset region 41b of each opening 41. Therefore, in the printing step S2, the solder paste 5 is printed on the pads 22 except for the pad margins 22a, and also on the portions of the mounting surface 21 that are outside the pads 22 relative to the main body space. Furthermore, the mask body 4 prevents the solder paste 5 from being printed on the mounting surface 21 and each pad 22 other than those located in the regions of the openings 41. Therefore, by filling each opening 41 with solder paste 5, the mask body 4 limits the area where the solder paste 5 is printed on the mounting surface 21 and each pad 22 to the area of ​​each opening 41. The shape of the solder paste 5 filled in each opening 41 is rectangular, as shown in FIG.

[0027] <Mask removal process S3> After the printing step S2, a mask removing step S3 is carried out. In the mask removing step S3, the mask body 4 is removed from the mask position, so that the solder paste 5 in each opening 41 remains as a plurality of paste forming portions.

[0028] In the mask removal process S3, the mask body 4 is removed from the mask position so as not to distort the shape of the solder paste 5 in each opening 41. As a result, the solder paste 5 in each opening 41 is removed from the mask body 4 while retaining the shape of each opening 41, and remains on the mounting surface 21 and each pad 22 as multiple paste-forming portions.

[0029] <Mounting component placement process S4> After the mask removal step S3, the component placement step S4 is carried out. In the component placement step S4, the electrodes 12 are placed on the pads 22 via the paste formation sections, and the component body 11 is placed in the body space.

[0030] Fig. 8 is a top view showing a state when a mounting component 1 is placed on the substrate 2 after the mask body 4 of Fig. 6 has been removed from the mask position. Fig. 9 is a cross-sectional view taken along line IX-IX of Fig. 8. Paste formation portions 51 remaining after the mask body 4 has been removed from the mask position in the mask removal step S3 are formed on the mounting surface 21 and each pad 22 in correspondence with each pad 22.

[0031] The paste forming portion 51 overlaps the pad 22, avoiding the pad margin portion 22a, and overlaps the mounting surface 21 at a position that protrudes outward from the pad 22 relative to the space for the main body. In the paste forming portion 51, the portion formed by the overlapping region 41a of the opening 41 overlaps the pad 22, and the portion formed by the outward region 41b of the opening 41 protrudes from the pad 22 and overlaps the mounting surface 21. Therefore, the area of ​​the portion of the paste forming portion 51 that overlaps the pad 22 is one-third or more of the area of ​​the paste forming portion 51. Furthermore, the thickness of the portion of the paste forming portion 51 that overlaps the pad 22 is the same as the thickness of the mask main body 4. The area of ​​the portion of the paste forming portion 51 that protrudes from the pad 22 is three-quarters or less of the area of ​​the corresponding pad 22.

[0032] The dimension L01 of the mounting component 1 in the component first reference direction is larger than the inter-pad first direction distance d2. In the mounting component placement process S4, the component body 11 is placed in the body space by aligning each electrode 12 with a position that overlaps each pad 22. As a result, the component first reference direction of the component body 11 coincides with the mounting surface first reference direction x.

[0033] In the mounting component placement process S4, the length of the pad margin 22a in the first reference direction x of the mounting surface, i.e., the pad margin first-direction length L1, is equal to or greater than 1 / 3 of the length in the first reference direction x of the mounting surface of the area where the mounting component 1 overlaps the pad 22, i.e., the component overlap first-direction length Ld. Therefore, the opening-to-opening first-direction distance d1 and the pad-to-pad first-direction distance d2 are adjusted with respect to the dimension L01 of the mounting component 1 in the component first reference direction so that the pad margin first-direction length L1 is equal to or greater than 1 / 3 of the component overlap first-direction length Ld.

[0034] Fig. 10 is a top view showing the state in which each electrode 12 of Fig. 8 is placed on each paste forming portion 51. Fig. 11 is a cross-sectional view taken along line XI-XI of Fig. 10. In the mounting component placement step S4, each electrode 12 is placed on each paste forming portion 51, and the portion of the paste forming portion 51 on which the electrode 12 is placed is crushed by the electrode 12. The paste forming portion 51 crushed by the electrode 12 spreads as solder paste 5 in the pad margin portion 22a. This prevents the solder paste 5 from spilling out of the pad 22 in the mounting component placement step S4.

[0035] <Joining process S5> After the mounting component placement process S4, a bonding process S5 is performed. In the bonding process S5, each paste forming portion 51 is melted to bond each electrode 12 to each pad 22. In the bonding process S5, each paste forming portion 51 is heated in a reflow furnace (not shown) to melt each paste forming portion 51.

[0036] When the paste forming portion 51 melts in the joining step S5, the paste forming portion 51 becomes molten solder and adheres to the electrode 12 and the pad 22. In the joining step S5, the molten solder adhered to the electrode 12 and the pad 22 cools and hardens, and the molten solder becomes the solder joint 3 shown in FIGS.

[0037] When the portion of the paste forming section 51 that protrudes from the pad 22 melts and becomes molten solder, the molten solder is pulled back to the pad 22 while agglomerating from the position where it protruded from the pad 22 toward the electrode 12. In the joining step S5, the molten solder is pulled back to the pad 22 from the position where it protruded from the pad 22, making it difficult for a solder joint 3 to be formed at the position where it protruded from the pad 22. Furthermore, in the joining step S5, the molten solder is agglomerated toward the electrode 12, ensuring the amount of solder joint 3 that contributes to the joining of the electrode 12 to the pad 22. This ensures the joining strength of the electrode 12 to the pad 22. By individually joining each electrode 12 to each pad 22 in this manner, the mounting component 1 is mounted on the mounting surface 21 of the substrate 2, as shown in FIGS. 1 and 2 .

[0038] In this mounting method for mounting components, the mask body 4 is placed at the mask position in the mask placement step S1. As a result, the position of each opening 41 is shifted outward from the corresponding pad 22 with respect to the body space. A part of the pad 22 becomes a pad margin 22a that is outside the overlapping range of the opening 41 due to the position of the opening 41 being shifted from the pad 22. The area of ​​each opening 41 is the same as the area of ​​the corresponding pad 22.

[0039] Therefore, by filling the opening 41 with solder paste 5, the paste forming portion 51 can be overlapped on the pad 22 while avoiding the pad margin 22a. As a result, even if a part of the paste forming portion 51 is crushed by the electrode 12 placed on the paste forming portion 51, the crushed part of the paste forming portion 51 can be made to spread into the pad margin 22a. Therefore, the solder paste 5 can be made less likely to spill out of the pad 22.

[0040] If the solder paste 5 overflows from the pad 22 into the gap between the component body 11 and the mounting surface 21, even if the solder paste 5 turns into molten solder in the joining step S5, the mounted component 1 gets in the way and makes it difficult for the molten solder to be drawn back to the pad 22. This makes it more likely that the solder paste 5 overflowing into the gap between the component body 11 and the mounting surface 21 will turn into a solder ball in the joining step S5.

[0041] In this embodiment, the solder paste 5 is less likely to overflow from the pad 22 into the gap between the component body 11 and the mounting surface 21, thereby preventing problems caused by the solder paste 5 overflowing from the pad 22, such as the formation of solder balls.

[0042] Furthermore, the paste forming portion 51 can also be formed in the area that protrudes outward from the pad 22 relative to the main body space. This allows the amount of solder paste 5 that is insufficient when printing on the pad 22 while avoiding the pad margin 22a to be replenished by the portion of the paste forming portion 51 that protrudes from the pad 22. This makes it possible to prevent a decrease in the amount of solder paste 5 that is the raw material for the solder joint 3 that joins the electrode 12 to the pad 22.

[0043] Since the paste forming portion 51 is melted in the joining step S5 to become molten solder, the molten solder that spills out from the pad 22 into the main body space is pulled back to the pad 22 while coagulating toward the electrode 12. This ensures a sufficient amount of molten solder adhering to the electrode 12 and the pad 22, and prevents a decrease in the amount of solder joint 3 that contributes to joining the electrode 12 to the pad 22. Therefore, a decrease in the joining strength of the electrode 12 to the pad 22 can be prevented. Furthermore, because the portion of the paste forming portion 51 that spills out from the pad 22 can be pulled back to the pad 22, problems caused by the solder paste 5 spilling out from the pad 22 can also be prevented.

[0044] Furthermore, the thickness t1 of the mask body 4 is 100 μm or more and 150 μm or less. In the mounting component placement process S4, the pad margin first-direction length L1 is ⅓ or more of the component overlap first-direction length Ld. Therefore, even if a portion of the paste forming portion 51 is crushed by the electrode 12 placed on the paste forming portion 51, the range over which the crushed portion of the paste forming portion 51 spreads can be more reliably contained within the pad margin 22a. This more reliably prevents problems caused by the solder paste 5 spilling out of the pad 22.

[0045] Furthermore, in the mask placement step S1, the area of ​​the overlapping region 41a in the opening 41 is ⅓ or more of the area of ​​the opening 41. Also, in the mask placement step S1, the area of ​​the off-center region 41b in the opening 41 is ¾ or less of the area of ​​the corresponding pad 22. Therefore, the area of ​​the portion of the paste-forming portion 51 overlapping the pad 22 can be ⅓ or more of the area of ​​the paste-forming portion 51, and the area of ​​the portion of the paste-forming portion 51 extending beyond the pad 22 can be ¾ or less of the area of ​​the corresponding pad 22. This facilitates the condensation of molten solder produced by melting the paste-forming portion 51 toward the electrode 12 in the bonding step S5, and facilitates the retraction of molten solder from the portion extending beyond the pad 22 back to the pad 22. Therefore, a reduction in the amount of the solder joint 3 contributing to the bonding of the electrode 12 to the pad 22 can be more reliably prevented, and a reduction in the bonding strength of the electrode 12 to the pad 22 can be more reliably prevented. Furthermore, problems caused by solder paste 5 spilling out from pads 22 can be more reliably prevented.

[0046] Furthermore, in this metal mask, a plurality of openings 41 corresponding to the plurality of pads 22 are formed in the mask body 4. The mask body 4 is placed at a mask position that covers the mounting surface 21 to which the plurality of pads 22 are fixed. By filling each opening 41 with solder paste 5, the mask body 4 limits the area where the solder paste 5 is printed on the mounting surface 21 and each pad 22 to the area of ​​each opening 41. By placing the mask body 4 at the mask position, the position of each opening 41 is shifted outward from the corresponding pad 22 with respect to the body space. Because the position of the opening 41 is shifted from the pad 22, a portion of the pad 22 becomes a pad margin 22a that is outside the area where the opening 41 overlaps. The area of ​​each opening 41 is the same as the area of ​​the corresponding pad 22.

[0047] Therefore, by filling the opening 41 with solder paste 5, the paste forming portion 51 can be overlapped with the pad 22, avoiding the pad margin 22a. As a result, even if a part of the paste forming portion 51 is crushed by the electrode 12, the crushed part of the paste forming portion 51 spreads in the pad margin 22a, making it difficult for the solder paste 5 to spill out from the pad 22. This makes it possible to prevent problems caused by the solder paste 5 spilling out from the pad 22.

[0048] Furthermore, the paste forming portion 51 can also be formed in the area that protrudes outward from the pad 22 relative to the main body space. This makes it possible to prevent a decrease in the amount of solder paste 5, which is the raw material for the solder joint 3 that joins the electrode 12 to the pad 22. Furthermore, by melting the paste forming portion 51 to form molten solder, the molten solder that has protruded from the pad 22 can be pulled back to the pad 22 while being coagulated toward the electrode 12. This makes it possible to prevent a decrease in the bonding strength of the electrode 12 to the pad 22. It is also possible to prevent defects caused by the solder paste 5 that has protruded from the pad 22.

[0049] Embodiment 2 In the first embodiment, each opening 41 has a rectangular shape. However, each opening 41 may have a circular shape.

[0050] FIG. 12 is a top view showing a state in which the mask body 4 of the metal mask according to the second embodiment is placed at the mask position relative to the substrate 2 and the openings 41 are filled with solder paste 5. FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 12. In this embodiment, the procedure for mounting the mounting component 1 on the mounting surface 21 of the substrate 2 is the same as in the first embodiment. Therefore, when mounting the mounting component 1 on the mounting surface 21 of the substrate 2 in this embodiment, the mask placement step S1, printing step S2, mask removal step S3, mounting component placement step S4, and bonding step S5 are performed in this order. FIGS. 12 and 13 show the state after the printing step S2 in this embodiment.

[0051] In this embodiment, the thickness t1 of the mask body 4 is 130 μm. In addition, in this embodiment, the distance between two pads 22 in the first reference direction x of the mounting surface, i.e., the first-direction inter-pad distance d2, is 0.4 mm. Each pad 22 is square in shape. The length of each side of each pad 22 is 0.6 mm.

[0052] Each of the two openings 41 formed in the mask body 4 has a circular shape, as shown in Fig. 12. The radius R1 of each opening 41 is 0.7 mm. As a result, the area of ​​each opening 41 is 0.385 mm 2 , which is equal to or greater than the area of ​​the corresponding pad 22.

[0053] The distance between two openings 41 in the mask first reference direction, i.e., the inter-opening first-direction distance d1, is greater than the inter-pad first-direction distance d2. The inter-opening first-direction distance d1 is the shortest distance between the two openings 41. In this embodiment, the inter-opening first-direction distance d1 is 0.6 mm. As a result, when the mask body 4 is placed at the mask position in the mask placement step S1, the position of each opening 41 is shifted outward from the corresponding pad 22 with respect to the body space.

[0054] In the mask placement step S1, the area of ​​the overlapping region 41a in the opening 41 is approximately 0.297 mm 2 The area of ​​the detached region 41b in the opening 41 is about 0.087 mm 2 Therefore, the area of ​​the overlap region 41a of the opening 41 in the mask placement step S1 is equal to or greater than one-third of the area of ​​the opening 41. Moreover, the area of ​​the off-region region 41b of the opening 41 in the mask placement step S1 is equal to or less than three-quarters of the area of ​​the corresponding pad 22.

[0055] In the printing step S2, the solder paste 5 is filled into each opening 41. As a result, the area where the solder paste 5 is printed on the mounting surface 21 and each pad 22 is limited to the area of ​​each opening 41.

[0056] In the mask removal step S3, the mask body 4 is removed from the mask position, causing the solder paste 5 to be removed from each opening 41, forming a plurality of paste forming portions 51. If the opening 41 has a rectangular shape as in the first embodiment, it is difficult for a portion of the solder paste 5 to come off from the four corners of the opening 41 in the mask removal step S3. In contrast, in the present embodiment, the opening 41 has a circular shape, and therefore no corners are present in the opening 41, making it easier for the entire solder paste 5 to come off from the mask body 4 in the mask removal step S3.

[0057] Fig. 14 is a top view showing a state when a mounting component 1 is placed on the mounting surface 21 of the substrate 2 after the mask body 4 in Fig. 12 has been removed from the mask position. Fig. 15 is a cross-sectional view taken along line XV-XV in Fig. 14. Figs. 14 and 15 show a state when the mounting component placement step S4 is performed in this embodiment. In this embodiment, a chip resistor is used as the mounting component 1 used in the mounting component placement step S4.

[0058] In the mounting component placement process S4, the portion of the paste forming portion 51 formed by the overlapping region 41a of the opening 41 overlaps with the pad 22, and the portion formed by the off-region 41b of the opening 41 protrudes from the pad 22 and overlaps with the mounting surface 21. Therefore, the area of ​​the portion of the paste forming portion 51 overlapping with the pad 22 is one-third or more of the area of ​​the paste forming portion 51. Furthermore, the area of ​​the portion of the paste forming portion 51 protruding from the pad 22 is three-quarters or less of the area of ​​the corresponding pad 22.

[0059] In the mounting component placement process S4, the mounting component 1 is placed in the body space with the component first reference direction of the component body 11 aligned with the mounting surface first reference direction x and the component second reference direction of the component body 11 aligned with the mounting surface second reference direction y. In this embodiment, the dimension L01 of the mounting component 1 in the component first reference direction is 1.0 mm, and the dimension of the mounting component 1 in the component second reference direction is 0.5 mm. Since the inter-pad first-direction distance d2 is 0.4 mm, the component overlap first-direction length Ld is 0.3 mm. Furthermore, the pad margin first-direction length L1 is 0.1 mm. In this embodiment, the minimum dimension of the pad margin portion 22a in the mounting surface first reference direction x is set to the pad margin first-direction length L1. As a result, in the mounting component placement process S4, the pad margin first-direction length L1 is at least one-third of the component overlap first-direction length Ld. The other configurations are the same as those in the first embodiment.

[0060] In this mounting method for mounting components, each opening 41 formed in the mask body 4 is circular. This configuration also achieves the same effects as in the first embodiment. Furthermore, when the mask body 4 is removed from the mask position in the mask removal step S3, the solder paste 5 filled in each opening 41 can be easily removed from the mask body 4. This more reliably ensures the amount of each paste formation portion 51 superimposed on the mounting surface 21 and each pad 22. Therefore, a decrease in the bonding strength of the electrode 12 to the pad 22 can be more reliably suppressed. Furthermore, the paste formation portion 51 can be prevented from collapsing. Furthermore, the solder paste 5 can be prevented from remaining in the opening 41 while adhering to the mask body 4 after it has been removed from the mask position. This reduces the likelihood of the opening 41 becoming clogged with the solder paste 5, thereby reducing the burden of cleaning the mask body 4.

[0061] In the second embodiment, each opening 41 has a circular shape. However, the shape of the opening 41 is not limited to a circular shape. For example, the four corners of a rectangular opening 41 may be arc-shaped. That is, the opening 41 may be rectangular with the four corners arc-shaped. Even in this case, when the mask body 4 is removed from the mask position in the mask removal step S3, the solder paste 5 is more likely to come off from the four corners of the opening 41, and the entire solder paste 5 can be more easily removed from the mask body 4.

[0062] Embodiment 3 Fig. 16 is a top view showing a state in which a mounting component is mounted on a substrate according to embodiment 3. Fig. 17 is a front view showing the mounting component and the substrate as viewed along arrow XVII in Fig. 16. In this embodiment, three electrodes 12 are provided on component body 11 of mounting component 1.

[0063] The component body 11 has a first side surface 11a and a second side surface 11b that face each other in a component first reference direction. The component body 11 is placed in the body space with the component first reference direction aligned with the mounting surface first reference direction x and the component second reference direction aligned with the mounting surface second reference direction y. In this embodiment, one electrode 12 is provided on the first side surface 11a of the component body 11, and two electrodes 12 are provided on the second side surface 11b of the component body 11. The two electrodes 12 provided on the second side surface 11b are spaced apart in the direction along the second side surface 11b. As a result, when the component body 11 is placed in the body space, the two electrodes 12 provided on the second side surface 11b are spaced apart in the mounting surface second reference direction y.

[0064] Three pads 22 corresponding to the three electrodes 12 are fixed to the mounting surface 21 of the substrate 2. Each pad 22 is rectangular. The position of each pad 22 on the mounting surface 21 is set to match the position of each electrode 12 of the mounting component 1. As a result, of the three pads 22, two pads 22 are arranged spaced apart from each other in the second mounting surface reference direction y, and the remaining pad 22 is arranged at a position separated from the two pads 22 in the first mounting surface reference direction x.

[0065] When the mounting component 1 is viewed in a direction perpendicular to the mounting surface 21, each electrode 12 overlaps a corresponding pad 22. Each electrode 12 is joined to a corresponding pad 22 via a solder joint 3. The mounting component 1 is mounted on the mounting surface 21 of the substrate 2 with each electrode 12 joined to each pad 22.

[0066] The method for mounting a component in this embodiment is the same as that in embodiment 1. Therefore, when mounting a component 1 on the mounting surface 21 of a substrate 2 in this embodiment, the steps of mask placement step S1, printing step S2, mask removal step S3, component placement step S4, and bonding step S5 are carried out in this order.

[0067] Fig. 18 is a top view showing a state in which the mask body 4 of the metal mask used in the mask placement step S1 according to the third embodiment is placed on the substrate 2. Fig. 19 is a cross-sectional view taken along line XIX-XIX in Fig. 18. In the mask placement step S1, as in the first embodiment, the mask body 4 is placed at a mask position that covers the mounting surface 21 to which the plurality of pads 22 are fixed.

[0068] Three openings 41 are formed in the mask body 4 corresponding to the three pads 22. The positional relationship of the three openings 41 formed in the mask body 4 corresponds to the positional relationship of the three pads 22 fixed to the mounting surface 21. Therefore, of the three openings 41, two openings 41 are formed spaced apart from each other in the mask second reference direction, and the remaining opening 41 is formed at a position separated from the two openings 41 in the mask first reference direction. In this embodiment, the area of ​​each opening 41 is the same as the area of ​​the corresponding pad 22. Furthermore, in this embodiment, the shape of each opening 41 is rectangular.

[0069] In the mask placement step S1, the mask body 4 is placed at the mask position with the mask first reference direction aligned with the mounting surface first reference direction x and the mask second reference direction aligned with the mounting surface second reference direction y. As a result, in the mask placement step S1, when the mask body 4 is placed at the mask position, each opening 41 overlaps with the corresponding pad 22.

[0070] The first-direction distance d1 between the openings in the first reference direction x of the mounting surface is larger than the first-direction distance d2 between the pads in the first reference direction x of the mounting surface. As a result, when the mask body 4 is placed at the mask position, the position of each opening 41 is shifted outward from the corresponding pad 22 with respect to the body space. As a result of the position of the opening 41 being shifted from the pad 22, part of the pad 22 becomes a pad margin 22a that is outside the range where the opening 41 overlaps.

[0071] In the mask placement step S1, the area of ​​the overlapping region 41a of the opening 41 is equal to or greater than one-third of the area of ​​the opening 41. Also, in the mask placement step S1, the area of ​​the off-region 41b of the opening 41 is equal to or less than three-quarters of the area of ​​the corresponding pad 22.

[0072] 20 is a top view showing the state in which each opening 41 in FIG. 18 has been filled with solder paste 5. FIG. 21 is a cross-sectional view taken along line XXI-XXI in FIG. 20. In the printing step S2, each of the three openings 41 is filled with solder paste 5. This limits the area in which the solder paste 5 is printed on the mounting surface 21 and each pad 22 to the area of ​​each opening 41. Therefore, in the printing step S2, the solder paste 5 is printed corresponding to each of the three pads 22. In the printing step S2, the solder paste 5 is printed on the areas of the pads 22 other than the pad margins 22a, and also on the areas of the mounting surface 21 that are outwardly spaced from the pads 22 relative to the space for the main body.

[0073] Fig. 22 is a top view showing a state in which a mounting component 1 is placed on the mounting surface 21 of the substrate 2 after the mask body 4 in Fig. 20 has been removed from the mask position. Fig. 23 is a front view showing the mounting component 1 and the substrate 2 as viewed along the arrow XXIII in Fig. 22. On the mounting surface 21 and each pad 22, paste formation portions 51 remaining after the mask body 4 has been removed from the mask position in the mask removing step S3 are formed corresponding to each pad 22.

[0074] In the mounting component placement process S4, each electrode 12 is placed on each paste forming portion 51, and the portion of the paste forming portion 51 on which the electrode 12 is placed is crushed by the electrode 12. The paste forming portion 51 crushed by the electrode 12 spreads in the pad margin portion 22a as solder paste 5. This prevents the solder paste 5 from spilling out from the pad 22 into the gap between the component body 11 and the mounting surface 21 in the mounting component placement process S4.

[0075] On the other hand, in the mounting component placement process S4, a portion of the paste forming portion 51 may be crushed by the electrode 12, causing the solder paste 5 to overflow to both sides of the pad 22. In this case, there is a risk that the solder paste 5 overflowing from each of the two pads 22 may come into contact with each other between two pads 22 that are adjacent to each other in the second mounting surface reference direction y. If the solder paste 5 overflowing from each of the two pads 22 comes into contact with each other in the mounting component placement process S4, there is a risk that a solder bridge will be formed between the two adjacent electrodes 12 in the joining process S5, causing a short circuit between the two electrodes 12.

[0076] In this embodiment, the distance between the two electrodes 12 provided on the second side surface 11b of the component body 11 is ensured to be sufficiently large so that a solder bridge does not form between them. Therefore, the distance between two adjacent pads 22 in the second mounting surface reference direction y, i.e., the inter-pad second direction distance, is ensured to be sufficiently large. The inter-pad second direction distance is, for example, greater than 0.2 mm. The other configurations are the same as those in the first embodiment.

[0077] In this way, when mounting component 1 having multiple electrodes 12 provided on second side surface 11b, which is the common side surface, on mounting surface 21 of substrate 2, a sufficiently large distance is ensured between multiple electrodes 12, making it difficult for solder bridges to form between multiple electrodes 12. This makes it possible to prevent problems caused by solder paste 5 spilling out from each pad 22.

[0078] In the third embodiment, each opening 41 has a rectangular shape. However, each opening 41 may have a circular shape as in the second embodiment. Also, each opening 41 may have a rectangular shape with four arc-shaped corners.

[0079] Embodiment 4 Fig. 24 is a top view showing a state in which a mounting component is mounted on a substrate according to embodiment 4. Fig. 25 is a front view showing the mounting component and the substrate as viewed along the arrow XXV in Fig. 24. In this embodiment, a multiple chip resistor in which four resistors are continuously integrated is used as the mounting component 1. As a result, in this embodiment, eight electrodes 12 are provided on the component body 11.

[0080] The component body 11 has a first side surface 11a and a second side surface 11b that face each other in the component first reference direction. In the mounting component 1, four resistors are integrated into a continuous state in the component second reference direction. Of the eight electrodes 12, four electrodes 12, which are a portion of the electrodes 12, are provided as four first electrodes 121 on the common first side surface 11a of the component body 11. Furthermore, the remaining four electrodes 12 of the eight electrodes 12 are provided as four second electrodes 122 on the common second side surface 11b of the component body 11.

[0081] The four first electrodes 121 are arranged at intervals from one another in the direction along the first side surface 11a. The four first electrodes 121 are arranged at equal intervals in the component second reference direction to match the positions of the four resistors. The four second electrodes 122 are arranged at equal intervals from one another in the direction along the second side surface 11b. The four second electrodes 122 are arranged at equal intervals in the component second reference direction to match the positions of the four resistors. The first electrodes 121 and the second electrodes 122 are arranged at positions spaced apart from one another across the component body 11 in the component first reference direction.

[0082] The dimension L01 of the mounting component 1 in the component first reference direction is 1.0 mm. The dimension L02 of the mounting component 1 in the component second reference direction is 2.0 mm. The component body 11 is placed in the body space with the component first reference direction aligned with the mounting surface first reference direction x and the component second reference direction aligned with the mounting surface second reference direction y.

[0083] Eight pads 22 corresponding to the eight electrodes 12 are fixed to the mounting surface 21 of the substrate 2. Each pad 22 is rectangular. All pads 22 have the same shape and size. The position of each pad 22 on the mounting surface 21 is set to match the position of each electrode 12 on the mounting component 1.

[0084] As a result, some of the eight pads 22 are fixed to the mounting surface 21 as four first pads 221 to which four first electrodes 121 are individually bonded. The four first pads 221 are arranged at intervals in the mounting surface second reference direction y. In this embodiment, the four first pads 221 are arranged at equal intervals.

[0085] Of the eight pads 22, the remaining four pads 22 are fixed to the mounting surface 21 as four second pads 222 to which the four second electrodes 122 are individually bonded. The four second pads 222 are arranged at intervals in the mounting surface second reference direction y. In this embodiment, the four second pads 222 are arranged at equal intervals. The first pad 221 and the second pad 222 are arranged at positions spaced apart from each other in the mounting surface first reference direction x, with a space for the main body interposed between them.

[0086] When the mounting component 1 is viewed in a direction perpendicular to the mounting surface 21, each electrode 12 overlaps a corresponding pad 22. Therefore, each first electrode 121 overlaps a corresponding first pad 221, and each second electrode 122 overlaps a corresponding second pad 222. Each electrode 12 is joined to a corresponding pad 22 via a solder joint 3. The mounting component 1 is mounted on the mounting surface 21 of the substrate 2 with each electrode 12 joined to a corresponding pad 22.

[0087] The method for mounting a component in this embodiment is the same as that in embodiment 1. Therefore, when mounting a component 1 on the mounting surface 21 of a substrate 2 in this embodiment, the steps of mask placement step S1, printing step S2, mask removal step S3, component placement step S4, and bonding step S5 are carried out in this order.

[0088] Fig. 26 is a top view showing a state in which the mask body 4 of the metal mask used in the mask placement step S1 according to the fourth embodiment is placed on the substrate 2. Fig. 27 is a cross-sectional view taken along the line XXVII-XXVII in Fig. 19. In the mask placement step S1, as in the first embodiment, the mask body 4 is placed at a mask position that covers the mounting surface 21 to which the plurality of pads 22 are fixed.

[0089] Eight openings 41 are formed in the mask body 4 corresponding to the eight pads 22. The positional relationship of the eight openings 41 formed in the mask body 4 corresponds to the positional relationship of the eight pads 22 fixed to the mounting surface 21. In this embodiment, the area of ​​each opening 41 is the same as the area of ​​the corresponding pad 22. Also, in this embodiment, the shape and size of each opening 41 are the same as the shape and size of each pad 22. Therefore, the shape of each opening 41 is rectangular.

[0090] Of the eight openings 41, some of the openings 41 are formed in the mask body 4 as four first openings 411 corresponding to the four first pads 221. The four first openings 411 are arranged at intervals in the mask second reference direction. In the present embodiment, the first openings 411 are arranged at equal intervals.

[0091] Of the eight openings 41, the remaining four openings 41 are formed in the mask body 4 as four second openings 412 corresponding to the four second pads 222. The four second openings 412 are arranged at intervals in the mask second reference direction. In the present embodiment, the second openings 412 are arranged at equal intervals.

[0092] Each second opening 412 is formed at a position in the mask first reference direction that is spaced apart from the position of each first opening 411. The mask body 4 is disposed at the mask position such that the mask first reference direction coincides with the mounting surface first reference direction x and the mask second reference direction coincides with the mounting surface second reference direction y.

[0093] The distance between the first opening 411 and the second opening 412 in the mask first reference direction, i.e., the inter-opening first direction distance d1, is greater than the distance between the first pad 221 and the second pad 222 in the mounting surface first reference direction x, i.e., the inter-pad first direction distance d2. As a result, by placing the mask body 4 at the mask position in the mask placement process S1, the position of each first opening 411 is shifted outward from the corresponding first pad 221 with respect to the main body space of the component body 11. Furthermore, by placing the mask body 4 at the mask position in the mask placement process S1, the position of each second opening 412 is shifted outward from the corresponding second pad 222 with respect to the main body space of the component body 11.

[0094] Furthermore, when the mask body 4 is placed at the mask position in the mask placement step S1, the positions of two adjacent first openings 411 are shifted to the same side from the corresponding two first pads 221 in the direction in which the first pads 221 are lined up, i.e., in the mounting surface second reference direction y. As a result, each first opening 411 is positioned at a position shifted from each first pad 221 in the direction in which the first pads 221 are lined up so that the two first openings 411 do not protrude into the gap between the two adjacent first pads 221.

[0095] Furthermore, when the mask body 4 is placed at the mask position in the mask placement step S1, the positions of two adjacent second openings 412 are shifted to the same side from the corresponding two second pads 222 in the direction in which the second pads 222 are lined up, i.e., in the second mounting surface reference direction y. As a result, each second opening 412 is positioned at a position shifted from each second pad 222 in the direction in which the second pads 222 are lined up so that the two second openings 412 do not protrude into the gap between the two adjacent second pads 222.

[0096] In this embodiment, when the mask body 4 is placed at the mask position in the mask placement process S1, the positions of each first opening 411 and each second opening 412 are all shifted to the same side from the corresponding pad 22 in the second reference direction y of the mounting surface.

[0097] A part of first pad 221 becomes pad margin 22a outside the overlapping range of first opening 411 due to the position of first opening 411 being shifted from first pad 221. Therefore, in this embodiment, the part of first pad 221 closer to the main body space than first opening 411 and the part of first pad 221 shifted from first opening 411 in the direction in which second pads 222 are lined up each become pad margin 22a.

[0098] A part of second pad 222 becomes pad margin 22a outside the overlapping range of second opening 412 due to the position of second opening 412 being shifted from second pad 222. In this embodiment, the part of second pad 222 closer to the main body space than second opening 412 and the part of second pad 222 shifted from second opening 412 in the direction in which second pads 222 are lined up each become pad margin 22a.

[0099] When the mask body 4 is placed in the mask position, the outward area 41b of each first opening 411 not only protrudes outward from the first pad 221 relative to the space for the body, but also protrudes from the first pad 221 to the side to which the first opening 411 is shifted in the direction in which the first pads 221 are arranged.

[0100] When the mask body 4 is placed in the mask position, the offset area 41b of each second opening 412 not only protrudes outward from the second pad 222 relative to the space for the body, but also protrudes from the second pad 222 to the side to which the second opening 412 is shifted in the direction in which the second pads 222 are arranged.

[0101] The dimension L11 of each pad 22 in the mounting surface first reference direction x is 0.4 mm, and the dimension L21 of each pad 22 in the mounting surface second reference direction y is 0.3 mm. The dimension L12 of each opening 41 in the mask first reference direction is 0.4 mm, and the dimension L22 of each opening 41 in the mounting surface second reference direction y is 0.3 mm. Therefore, in this embodiment, the area of ​​each opening 41 is the same as the area of ​​each pad 22.

[0102] The distance between two pads 22 in the first reference direction x of the mounting surface, i.e., the inter-pad first direction distance d2, is 0.6 mm. The distance between two openings 41 in the first reference direction of the mask, i.e., the inter-opening first direction distance d1, is 0.74 mm. Therefore, in this embodiment, the dimension of the pad margin 22a of each pad 22 in the first reference direction x of the mounting surface, i.e., the pad margin first direction length L1, is 0.07 mm.

[0103] When the mask body 4 is placed at the mask position in the mask placement step S1, the position of each opening 41 is shifted by 0.1 mm in the second mounting surface reference direction y from the corresponding pad 22. As a result, in this embodiment, the dimension of the pad margin 22a of each pad 22 in the second mounting surface reference direction y, i.e., the pad margin second direction length L2, is 0.1 mm.

[0104] The distance between each first pad 221 in the second reference direction y on the mounting surface, i.e., the second direction inter-pad distance of the first pads 221, is 0.2 mm. As a result, in the mask placement step S1, of two adjacent first pads 221, the dimension of the gap between one first opening 411 shifted from one first pad 221 toward the other first pad 221 and the other first pad 221, i.e., the adjacent gap dimension d3 of the first pads 221, is 0.1 mm.

[0105] The distance between each second pad 222 in the second reference direction y on the mounting surface, i.e., the second-direction inter-pad distance between the second pads 222, is also 0.2 mm. As a result, in the mask placement step S1, the dimension of the gap between one of two adjacent second pads 222, which is shifted from one second pad 222 toward the other second pad 222, and the other second pad 222, i.e., the adjacent gap dimension of the second pads 222, is also 0.1 mm.

[0106] Therefore, in the mask placement step S1, the area of ​​the portion of the opening 41 that overlaps the pad 22, i.e., the area of ​​the overlapping region 41a, is 0.066 mm 2 This is equal to or greater than one-third of the area of ​​the opening 41. In the mask placement step S1, the area of ​​the portion of the opening 41 that protrudes from the pad 22, i.e., the area of ​​the off-area region 41b, is 0.054 mm 2 , which is 3 / 4 or less of the area of ​​the corresponding pad 22.

[0107] Fig. 28 is a top view showing the state in which each opening 41 in Fig. 26 has been filled with solder paste 5. Fig. 29 is a cross-sectional view taken along line XXIX-XXIX in Fig. 28. In the printing step S2, each opening 41 is filled with solder paste 5. This limits the area in which the solder paste 5 is printed on the mounting surface 21 and each pad 22 to the area of ​​each opening 41. Therefore, in the printing step S2, solder paste 5 is printed corresponding to each of the eight pads 22. In the printing step S2, solder paste 5 is printed on the portion of each pad 22 other than the pad margin portion 22a, and solder paste 5 is also printed on the portion of the mounting surface 21 that is outwardly spaced from each pad 22 relative to the space for the main body.

[0108] FIG. 30 is a top view showing a state in which a mounting component 1 is placed on the mounting surface 21 of the substrate 2 after the mask body 4 in FIG. 28 has been removed from its masking position. FIG. 31 is a front view showing the mounting component 1 and the substrate 2 as viewed along the arrow XXXI in FIG. 30. In the mounting component placement step S4, paste formation portions 51 remaining after the mask body 4 has been removed from its masking position in the mask removal step S3 are formed on the mounting surface 21 and on each pad 22 in correspondence with each pad 22. The shape and size of each paste formation portion 51 are the same as those of each opening 41. The position of each paste formation portion 51 relative to each pad 22 is also the same as the position of each opening 41 relative to each pad 22. The paste formation portions 51 overlap the pads 22, avoiding the pad margins 22a, and also extend beyond the pads 22 to overlap the mounting surface 21.

[0109] The dimension of the component body 11 in the component first reference direction is the same as the inter-pad first direction distance d2. In the mounting component placement process S4, the mounting component 1 is placed on the mounting surface 21 with the position of the first side surface 11a aligned with the position of the end of each first pad 221 on the body space side, and the position of the second side surface 11b aligned with the position of the end of each second pad 222 on the body space side.

[0110] The dimension of each electrode 12 in the component second reference direction is the same as the dimension L21 of each pad 22 in the mounting surface second reference direction y. In the mounting component placement process S4, each electrode 12 is placed on each paste formation portion 51 with the position of each electrode 12 aligned with the position of the corresponding pad 22 in the mounting surface second reference direction y.

[0111] In the mounting component placement process S4, a part of the paste forming portion 51 is crushed by the electrode 12, causing the solder paste 5 to spread in the pad margin portion 22a. As a result, the solder paste 5 that has spread in the pad margin portion 22a is prevented from spilling out of the pad 22.

[0112] Meanwhile, in the mounting component placement process S4, not only does the solder paste 5 spread into the pad margin portion 22a, but the solder paste 5 is also extruded from between the electrode 12 and the pad 22 in areas other than the pad margin portion 22a. At this time, the solder paste 5 extruded from between the electrode 12 and the pad 22 is stopped by the portion that has already protruded from the pad 22 in the paste forming portion 51. This prevents the solder paste 5 extruded from between the first electrode 121 and the first pad 221 from spreading to the adjacent first electrode 121. In addition, the solder paste 5 extruded from between the second electrode 122 and the second pad 222 from spreading to the adjacent second electrode 122.

[0113] The length in the first reference direction x of the mounting surface of the area where the mounting component 1 overlaps the pad 22, i.e., the component overlap first direction length Ld, is the same for both the first pad 221 and the second pad 222. In this embodiment, the component overlap first direction length Ld is 0.2 mm. As described above, in this embodiment, the pad margin first direction length L1 of each of the first pad 221 and the second pad 222 is 0.07 mm. As a result, the pad margin first direction length L1 is ⅓ or more of the component overlap first direction length Ld for both the first pad 221 and the second pad 222.

[0114] In the joining step S5, when the portion of the paste forming portion 51 that protrudes from the pad 22 melts and becomes molten solder, the molten solder is pulled back to the pad 22 while agglomerating from the position where it protrudes from the pad 22 toward the electrode 12. This makes it difficult for a solder joint 3 to be formed in the position where it protrudes from the pad 22 in the joining step S5. Also, in the joining step S5, the molten solder is agglomerated toward the electrode 12, thereby ensuring the amount of solder joint 3 that contributes to the joining of the electrode 12 to the pad 22. This ensures the joining strength of the electrode 12 to the pad 22. The other configurations are the same as those in the first embodiment.

[0115] In this mounting method for mounted components, when the mask body 4 is placed at the mask position in the mask placement step S1, the positions of two adjacent first openings 411 are shifted to the same side from the corresponding two first pads 221 in the direction in which the multiple first pads 221 are arranged. This makes it possible to prevent the positions of two paste formation portions 51 formed by the solder paste 5 filled in each of the two adjacent first openings 411 from approaching each other. This makes it possible to prevent the two paste formation portions 51 from connecting with each other between the two adjacent first pads 221 in the bonding step S5, and to prevent the formation of a solder bridge that shorts out the two first electrodes 121.

[0116] Furthermore, when the mask body 4 is placed at the mask position in the mask placement step S1, the positions of two adjacent second openings 412 are shifted to the same side from the corresponding two second pads 222 in the direction in which the multiple second pads 222 are arranged. This prevents the positions of two paste formation portions 51 formed by the solder paste 5 filled in each of the two adjacent second openings 412 from approaching each other. This prevents the two paste formation portions 51 from connecting with each other between the two adjacent second pads 222 in the bonding step S5, thereby preventing the formation of a solder bridge that short-circuits the two second electrodes 122.

[0117] Furthermore, in the mask placement process S1, the dimension of the gap between one of the first pads 221 and the first opening 411 that is shifted from one of the first pads 221 toward the other first pad 221, i.e., the adjacent gap dimension d3 of the first pads 221, is 0.1 mm. Therefore, a gap of 0.1 mm can be secured between the paste formation portion 51 formed in one of the first pads 221 and the other first pad 221, of the two adjacent first pads 221. This makes it possible to prevent the two adjacent first pads 221 from being connected by the paste formation portion 51, and more reliably prevent the formation of a solder bridge that shorts out the two first electrodes 121.

[0118] Furthermore, in the mask placement process S1, of two adjacent second pads 222, the dimension of the gap between the second opening 412 shifted from one second pad 222 toward the other second pad 222 and the other second pad 222 is 0.1 mm. Therefore, of the two adjacent second pads 222, a gap of 0.1 mm can be ensured between the paste formation portion 51 formed in one second pad 222 and the other second pad 222. This makes it possible to prevent the two adjacent second pads 222 from being connected by the paste formation portion 51, and more reliably prevent the formation of a solder bridge that shorts out the two second electrodes 122.

[0119] In the fourth embodiment, the adjacent gap dimension d3 of the first pads 221 is 0.1 mm. However, the adjacent gap dimension d3 of the first pads 221 may be greater than 0.1 mm. This more reliably prevents two adjacent second pads 222 from being connected by the paste forming portion 51, and more reliably prevents the formation of a solder bridge that short-circuits two first electrodes 121. In other words, if the adjacent gap dimension d3 of the first pads 221 is 0.1 mm or greater, the formation of a solder bridge that short-circuits two first electrodes 121 can be more reliably prevented.

[0120] Furthermore, in the fourth embodiment, the dimension of the gap between adjacent second pads 222 is 0.1 mm. However, the dimension of the gap between adjacent second pads 222 may be greater than 0.1 mm. This more reliably prevents two adjacent second pads 222 from being connected by the paste forming portion 51, and more reliably prevents the formation of a solder bridge that short-circuits two second electrodes 122. In other words, if the dimension of the gap between adjacent second pads 222 is 0.1 mm or greater, the formation of a solder bridge that short-circuits two second electrodes 122 can be more reliably prevented.

[0121] Furthermore, in the fourth embodiment, when the mask body 4 is placed at the mask position in the mask placement step S1, the positions of each of the first openings 411 and each of the second openings 412 are all shifted to the same side from the corresponding pad 22 in the second reference direction y of the mounting surface. However, this is not limited to this. For example, when the mask body 4 is placed at the mask position in the mask placement step S1, the positions of each of the first openings 411 and each of the second openings 412 may be shifted to opposite sides from the corresponding pad 22 in the second reference direction y of the mounting surface. In this case, the position of the paste formation portion 51 formed by each of the first openings 411 is shifted to one side from the corresponding first pad 221 in the second reference direction y of the mounting surface. In contrast, the position of the paste formation portion 51 formed by each of the second openings 412 is shifted to the other side from the corresponding second pad 222 in the second reference direction y of the mounting surface. 32, in the mounting component placement process S4, the paste formation portion 51 formed on each first pad 221 and the paste formation portion 51 formed on each second pad 222 are positioned to be shifted to opposite sides of the corresponding pad 22 in the second mounting surface reference direction y. This also makes it possible to prevent two adjacent first pads 221 from being connected by the paste formation portion 51, and more reliably prevents the formation of a solder bridge that shorts out two first electrodes 121.

[0122] Furthermore, in the fourth embodiment, when the mask body 4 is placed in the mask position, the positions of two adjacent first openings 411 may be shifted away from the corresponding two first pads 221 in the direction in which the first pads 221 are arranged. For example, of the four first openings 411, the positions of two adjacent first openings 411 located at intermediate positions may be shifted away from the corresponding two first pads 221 in the direction in which the first pads 221 are arranged.

[0123] In this case, the positions of the first openings 411 located at both ends of the four first openings 411 are also shifted away from the corresponding two first pads 221 in the direction in which the first pads 221 are arranged. In the mounting component placement process S4, as shown in Fig. 33, the positions of the two adjacent paste forming portions 51 located in the middle of the four paste forming portions 51 formed in each first pad 221 are shifted away from the corresponding two first pads 221. In this way, it is more reliably possible to prevent the paste forming portions 51 between two adjacent first pads 221 from coming into contact with each other, and it is possible to more reliably prevent two adjacent first pads 221 from being connected by the paste forming portions 51.

[0124] Furthermore, in the fourth embodiment, when the mask body is placed at the mask position, the positions of two adjacent second openings 412 may be shifted away from the corresponding two second pads 222 in the direction in which the second pads 222 are arranged. For example, of the four second openings 412, the positions of two adjacent second openings 412 located at intermediate positions may be shifted away from the corresponding two second pads 222 in the direction in which the second pads 222 are arranged.

[0125] In this case, the positions of the second openings 412 located at both ends of the four second openings 412 are also shifted away from the corresponding two second pads 222 in the direction in which the second pads 222 are arranged. In the mounting component placement process S4, as shown in Fig. 33, the positions of the two adjacent paste forming portions 51 located in the middle of the four paste forming portions 51 formed in each second pad 222 are shifted away from the corresponding two second pads 222. In this way, it is more likely that the paste forming portions 51 between two adjacent second pads 222 will come into contact with each other, and it is possible to more reliably prevent two adjacent second pads 222 from being connected by the paste forming portions 51.

[0126] Embodiment 5 In the fourth embodiment, each opening 41 has a rectangular shape. However, the four corners of the rectangular opening 41 may have an arc shape. That is, the shape of the opening 41 may be a rectangle with the four corners having an arc shape.

[0127] The method for mounting a component in this embodiment is the same as that in embodiment 4. Therefore, when mounting a component 1 on the mounting surface 21 of the substrate 2 in this embodiment, the steps of mask placement step S1, printing step S2, mask removal step S3, component placement step S4, and bonding step S5 are carried out in this order.

[0128] 34 is a top view showing a state in which the mask body 4 of the metal mask used in the mask placement step S1 according to embodiment 5 is placed on the substrate 2. In this embodiment, the shape of each opening 41 is different from the shape of the opening 41 in embodiment 4. The shape of each opening 41 in this embodiment is rectangular with four corners that are arc-shaped.

[0129] The shape and size of each pad 22 are the same as those in the fourth embodiment. That is, the dimension L11 of each pad 22 in the first reference direction x of the mounting surface is 0.4 mm, and the dimension L21 of each pad 22 in the second reference direction y of the mounting surface is 0.3 mm. The dimension L12 of each opening 41 in the first mask reference direction is 0.47 mm, and the dimension L22 of each opening 41 in the second reference direction y of the mounting surface is 0.3 mm. The four corners of each opening 41 are arc-shaped with a radius of 0.15 mm. Therefore, in this embodiment, the area of ​​each opening 41 is equal to or greater than the area of ​​each pad 22.

[0130] The distance d2 between the pads in the first direction is 0.6 mm. The distance d1 between the openings in the first direction is 0.74 mm. Therefore, the pad margin length L1 in the first direction is 0.07 mm.

[0131] The positional relationship between each opening 41 and each pad 22 is the same as in embodiment 1. Therefore, the pad margin second-direction length L2 is 0.1 mm. The distance between each first pad 221 in the mounting surface second reference direction y, i.e., the inter-pad second-direction distance between the first pads 221, is 0.2 mm. As a result, the adjacent gap dimension d3 of the first pads 221 is 0.1 mm.

[0132] The distance between the second pads 222 in the second reference direction y on the mounting surface, i.e., the second direction distance between the second pads 222, is also 0.2 mm. As a result, the adjacent gap dimension between the second pads 222 is also 0.1 mm.

[0133] Therefore, in the mask placement step S1, the area of ​​the overlapping region 41a of each opening 41 is about 0.040 mm 2 This is equal to or greater than one-third of the area of ​​the opening 41. In the mask placement step S1, the area of ​​the outside region 41b of the opening 41 is approximately 0.084 mm 2 , which is 3 / 4 or less of the area of ​​the corresponding pad 22.

[0134] FIG. 35 is a top view showing a state in which a mounting component 1 is placed on the substrate 2 after the mask body 4 has been removed from the mask position, leaving behind the solder paste 5 filled in each opening 41 of FIG. 34. In the mounting component placement step S4, paste formation portions 51 remaining after the mask body 4 has been removed from the mask position in the mask removal step S3 are formed on the mounting surface 21 and each pad 22 corresponding to each pad 22. Because the area where the solder paste 5 is printed on the mounting surface 21 and each pad 22 is limited to the area of ​​each opening 41, the shape and size of each paste formation portion 51 are the same as the shape and size of each opening 41. Furthermore, the position of each paste formation portion 51 relative to each pad 22 is also the same as the position of each opening 41 relative to each pad 22. The paste formation portions 51 overlap the pads 22, avoiding the pad margins 22a, and also extend beyond the pads 22 to overlap the mounting surface 21.

[0135] The length in the first reference direction x of the mounting surface of the area where the mounting component 1 overlaps the pad 22, i.e., the component overlap first direction length Ld, is the same for both the first pad 221 and the second pad 222. In this embodiment, as in the fourth embodiment, the component overlap first direction length Ld is 0.2 mm. As a result, for both the first pad 221 and the second pad 222, the pad margin first direction length L1 is ⅓ or more of the component overlap first direction length Ld. The other configurations are the same as in the fourth embodiment.

[0136] In this mounting method for mounted components, the shape of each opening 41 formed in the mask body 4 is rectangular with four arc-shaped corners. Therefore, when the mask body 4 is removed from its mask position in the mask removal step S3, the solder paste 5 filled in each opening 41 can be easily removed from the mask body 4. This more reliably prevents a decrease in the bonding strength between the electrode 12 and the pad 22. Furthermore, because the solder paste 5 filled in each opening 41 can be easily removed from the mask body 4, the shape of the paste formation portion 51 is less likely to be distorted in the mask removal step S3. This more reliably prevents problems caused by the solder paste 5 spilling out of the pad 22, such as the formation of a solder bridge between two electrodes 12. Furthermore, the openings 41 are less likely to be clogged with the solder paste 5, which reduces the burden of cleaning the mask body 4.

[0137] In addition, in embodiment 5, when the mask body 4 is placed at the mask position in the mask placement process S1, the positions of each first opening 411 and each second opening 412 may be shifted to opposite sides from the corresponding pad 22 in the mounting surface second reference direction y.

[0138] In addition, in embodiment 5, when the mask body is placed at the mask position, the positions of two adjacent first openings 411 may be shifted away from the corresponding two first pads 221 in the direction in which the first pads 221 are arranged.

[0139] In addition, in embodiment 5, when the mask body is placed at the mask position, the positions of two adjacent second openings 412 may be shifted away from the corresponding two second pads 222 in the direction in which the second pads 222 are arranged.

[0140] In the fifth embodiment, each opening 411 may be circular.

[0141] Furthermore, in the first, third, and fourth embodiments, the area of ​​each opening 41 is the same as the area of ​​the corresponding pad 22. However, the area of ​​each opening 41 may be larger than the area of ​​the corresponding pad 22. In this way, it is possible to more reliably prevent a decrease in the amount of solder joint 3 contributing to the joining of the electrode 12 to the pad 22, and it is possible to more reliably prevent a decrease in the joining strength of the electrode 12 to the pad 22. In each of the above-described embodiments, if the area of ​​each opening 41 is equal to or larger than the area of ​​the corresponding pad 22, it is possible to more reliably prevent a decrease in the joining strength of the electrode 12 to the pad 22.

[0142] The configurations described in the above embodiments are merely examples of the contents of the present disclosure. The embodiments can be combined with other known technologies. Part of the configuration of the embodiments can be omitted or modified without departing from the gist of the present disclosure. [Explanation of symbols]

[0143] 1 Mounted component, 2 Substrate, 4 Mask body, 5 Solder paste, 11 Component body, 12 Electrode, 21 Mounting surface, 22 Pad, 22a Pad margin, 41 Opening, 51 Paste forming portion, 121 First electrode, 221 First pad, 411 First opening.

Claims

1. a mask body having a plurality of openings formed therein corresponding to a plurality of pads fixed to a mounting surface of a substrate, the mask body being disposed at a mask position covering the mounting surface to which the plurality of pads are fixed; Equipped with the mask body limits an area where the solder paste is printed on the mounting surface and each of the pads to an area of ​​each of the openings by filling each of the openings with solder paste for individually joining a plurality of electrodes provided on a component body of the mounting component to the plurality of pads; the area of ​​each of the openings is equal to or greater than the area of ​​the corresponding pad; When the mask body is disposed at the mask position, the position of each of the openings is shifted outward from the corresponding pad with respect to a main body space, which is an arrangement space of the component main body, A metal mask in which a part of the pad becomes a pad margin outside the range where the opening overlaps, by the position of the opening being shifted from the pad.

2. some of the plurality of electrodes are provided as a plurality of first electrodes on a common side surface of the component body; some of the pads are arranged at intervals on the mounting surface as a plurality of first pads to which the plurality of first electrodes are individually bonded; some of the plurality of openings are formed in the mask body as a plurality of first openings corresponding to the plurality of first pads; 2. The metal mask according to claim 1, wherein when the mask body is positioned at the mask position, the positions of two adjacent first openings are shifted away from each other or to the same side from the corresponding two first pads in the direction in which the multiple first pads are arranged.

3. A mounting method for a mounting component, in which a plurality of electrodes provided on a component body of the mounting component are individually joined to a plurality of pads fixed to a mounting surface of a substrate, thereby mounting the mounting component on the substrate, comprising: a mask placement step of placing a mask body, the mask body having a plurality of openings formed therein corresponding to the plurality of pads, at a mask position covering the mounting surface to which the plurality of pads are fixed; a printing step of printing the solder paste onto the mounting surface and each of the pads by filling each of the openings with the solder paste for individually joining the plurality of electrodes to the plurality of pads after the mask placement step; a mask removing step of removing the mask body from the mask position after the printing step, thereby leaving the solder paste in each of the openings as a plurality of paste forming portions; a mounting component placement step of placing the electrodes on the pads via the paste forming portions after the mask removal step, and placing the component main body in a main body space, which is a placement space for the component main body; a bonding step of bonding each of the electrodes to each of the pads by melting each of the paste forming portions after the mounting component placement step; Equipped with the area of ​​each of the openings is equal to or greater than the area of ​​the corresponding pad; In the mask positioning step, the mask body is placed at the mask position, so that the positions of the openings are shifted outward from the corresponding pads with respect to the body space, A mounting method for a mounting component, wherein a part of the pad becomes a pad margin outside the range where the opening overlaps because the position of the opening is shifted from the pad.

4. some of the plurality of electrodes are provided as a plurality of first electrodes on a common side surface of the component body; some of the pads are arranged at intervals on the mounting surface as a plurality of first pads to which the plurality of first electrodes are individually bonded; some of the plurality of openings are formed in the mask body as a plurality of first openings corresponding to the plurality of first pads; 4. The mounting method for a mounting component according to claim 3, wherein when the mask body is placed at the mask position in the mask placement step, the positions of two adjacent first openings are shifted away from each other or to the same side from the corresponding two first pads in the direction in which the plurality of first pads are arranged.

5. 5. The mounting method for mounting components according to claim 4, wherein in the mask placement step, the dimension of the gap between the first opening, which is shifted from one of two adjacent first pads toward the other first pad, and the other first pad is 0.1 mm or more.

6. The thickness of the mask body is 100 μm or more and 150 μm or less, a direction in which the opening is shifted outward from the pad with respect to the main body space in the mask placement step coincides with a first mounting surface reference direction that is preset on the mounting surface; In the mounting component placement step, a length of the pad margin in the first reference direction of the mounting surface is equal to or greater than one-third of a length in the first reference direction of the mounting surface of an area where the mounting component overlaps the pad, In the mask placement step, an area of ​​a portion of the opening that overlaps the pad is equal to or greater than one-third of an area of ​​the opening, 6. The method for mounting a component according to claim 3, wherein in the mask placement step, the area of ​​the portion of the opening that protrudes from the pad is 3 / 4 or less of the area of ​​the corresponding pad.

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