JP5905756B2 - Alignment mask and solder bump forming method - Google Patents

Description

  The present invention relates to an array mask used for forming solder bumps and a solder bump forming method using the array mask.

  As a method for forming solder bumps, a method of mounting solder balls on a workpiece is known. This is a method of mounting a solder ball using an array mask having a through hole through which a solder ball can be inserted, corresponding to the array pattern of workpiece electrodes. Patent Documents 1 and 2 are disclosed as such an array mask.

JP 2006-287215 A JP 2006-324618 A

  By the way, after mounting the solder balls using the array mask, the solder balls are heated and melted to form bumps on the workpiece. The bumps formed on the workpiece have different heights, for example, height There are cases where it is necessary to form two different types of bumps on the workpiece (see FIG. 8C). In order to form such a bump, first, the first solder ball is mounted at a predetermined position by placing a first arrangement mask having a first through hole into which the first solder ball can be inserted on the workpiece, A second arrangement mask having a second through hole into which the second solder ball can be inserted is placed on the work and the second solder ball is mounted at another predetermined position, and then the heating and melting treatment is performed. As described above, in order to form bumps having different heights on the workpiece, solder ball mounting steps and arrangement masks are required for the number of types of bumps having different heights, and productivity is poor.

  The objective of this invention is providing the mask for arrangement | sequence which can solve the subject mentioned above.

The present invention is an array mask that includes through holes 12 corresponding to a predetermined array pattern and mounts the solder balls 2 at predetermined positions on the work 3 by swinging the solder balls 2 into the through holes 12. hole 12 includes a Tantsuana 13, possess a continuous hole 14, continuous hole 14, a plurality of single-hole 13 is formed chosen so as to be adjacent in a plan view, adjacent unit hole A part of 13 is overlapped . The continuous through hole 14 is characterized in that a plurality of single through holes 13 are formed in a straight line in a plan view . Further, the continuous through hole 14 is formed in a daruma shape in plan view . Further, wherein a plurality of Tantsuana 13 are made form in sleep with the circumferential shape in a plan view.

  According to another aspect of the present invention, there is provided a method for forming solder bumps, wherein solder bumps having different heights are formed at predetermined positions on a workpiece using the array mask having the above-described configuration.

  According to the arrangement mask according to the present invention, the through holes corresponding to the predetermined arrangement pattern are provided, and the through holes have a single through hole and a continuous through hole, and therefore, according to the shape of each through hole. A large number of solder balls can be transferred, and bumps having different heights can be formed on a workpiece with a single mask.

    Further, since the continuous through holes are formed by connecting a plurality of single through holes through which one solder ball can be inserted, the solder balls can be transferred into the continuous through holes by the number of continuous through holes. Specifically, if two straight through holes are connected in a straight line, a daruma-shaped continuous through hole is formed, and if three single through holes are connected in a circumferential shape, a clover-like continuous through hole is formed. By transferring the solder ball, a bump having a height corresponding to the through hole can be obtained with one mask.

It is a perspective view which shows the whole structure of the mask for arrangement | sequence which concerns on this invention, and a workpiece | work. It is a vertical side view which shows typically the mask for arrangement | sequence which concerns on this invention. It is a vertical side view which shows typically the mask for another arrangement | sequence which concerns on this invention. It is a top view which shows the mask for arrangement | sequence which concerns on this invention. It is explanatory drawing of the manufacturing method of the mask for arrangement | sequence which concerns on this invention. It is explanatory drawing of the manufacturing method of the mask for arrangement | sequence which concerns on this invention. It is a vertical side view showing typically another arrangement mask concerning the present invention. It is explanatory drawing of the mask for arrangement | sequence which concerns on 1st Embodiment of this invention. It is a partial top view of another mask for arrangement concerning a 1st embodiment of the present invention. It is a partial vertical side view of the mask for arrangement | sequence which concerns on 2nd Embodiment of this invention. It is a fragmentary top view of another mask for arrangement concerning a 2nd embodiment of the present invention. It is a partial vertical side view of another arrangement mask according to the second embodiment of the present invention.

(Outline of array mask)
1 to 3 show a solder ball arrangement mask according to the present invention. This arrangement mask (hereinafter simply referred to as a mask) 1 is used in the arrangement process of the solder balls 2 in the formation of solder bumps. Reference numeral 3 in FIG. 2 indicates a workpiece on which the solder ball 2 is mounted by the mask 1. The work 3 includes a wafer and a substrate. For example, a plurality of semiconductor chips 5 are mounted on a base 4 of a glass epoxy substrate, wired by wire bonding, and then sealed by transfer molding. 5, electrodes 6 as input / output terminals are formed in a predetermined pattern on the upper surface of the work 3. The work 3 is cut into individual pieces after the bumps are formed to form individual LSI chips.

  As shown in FIG. 1, the mask 1 is composed of a mask main body 10 made of a nickel alloy such as nickel or nickel cobalt, copper or other metal as a raw material, and the mask main body 10 surrounds the frame body. 11 can be installed. In the center of the board surface of the mask main body 10, a large number of pattern regions each including a large number of independent through holes 12 for inserting the solder balls 2 are formed corresponding to the respective semiconductor chips 5. As shown in FIG. 2, the through holes 12 have an arrangement pattern corresponding to the arrangement positions of the electrodes 6 of the respective semiconductor chips 5 on the workpiece 3. The solder ball 2 has a radial dimension of 50 μm or less, and in accordance with this, each through hole 12 is formed in a circular shape in plan view having an inner diameter dimension slightly larger than the radial dimension of the ball 2. Yes.

  A reinforcing frame 11 can be attached to the mask body 10. This frame 11 is a flat plate made of a material such as aluminum, 42 alloy, Invar, SUS430, etc., and has one rectangular opening corresponding to the mask body 10 at the center of the board surface. The mask body 10 is held by a single frame 11. The frame 11 is a molded product that is thicker than the mask body 10, and is integrally and integrally joined to the outer peripheral edge of the mask body 10. The thickness dimension of the frame 11 is, for example, about 0.05 to 1.0 mm, and is set to 0.5 mm here. The thickness of the mask main body 10 is preferably 10 μm or more, and is set to 200 μm here.

  On the lower surface side of the mask main body 10 (mask 1), that is, the surface facing the workpiece 3, a protruding portion 15 that protrudes downward can be provided. Specifically, as shown in FIG. 2 and FIG. 4A, a beam-like protrusion 15a can be provided on the outer periphery of the pattern area (between the pattern areas) so as to surround the pattern area. Moreover, as shown in FIG. 3, the protrusion part 15b can be provided in the position in which the through-hole 12 in the pattern area | region is not formed. If the projecting portion 15 is provided, it is possible to secure a facing gap between the mask main body 10 and the workpiece 3 by contacting the upper surface of the workpiece 3 during the arraying operation. As shown in FIGS. 2 and 3, each of the protrusions 15, particularly the protrusions 15 b, is preferably formed so as to be tapered from the lower surface of the mask body 10 between the through holes 12. It has a truncated cone shape. Further, the ratio of the height of the protrusion 15 to the thickness of the mask body 10 is preferably 2 to 1 or more, and it is more preferable that the thickness of the mask body 10 is within a range of 10 to 300 μm. preferable. Moreover, it is preferable that the ratio between the diameter L1 of the tip of the protrusion 15 and the diameter L2 of the root is 1: 3 or more. Furthermore, it is preferable that the ratio of the diameter of the tip of the protrusion 15, the diameter of the base, and the width between the through holes 12 is 1 to 3 to 3 or more. The protrusion 15 preferably has a large aspect ratio (ratio between the height of the protrusion 15 and the tip diameter), and has an aspect ratio of 3. As shown in FIGS. 2, 3, and 4 (a), a protrusion 15 a is provided between adjacent pattern regions so as to surround the pattern region so that the mask 1 is brought into contact with the workpiece 3 when placed on the workpiece 3. However, as shown in FIG. 4B, the entire pattern area between adjacent patterns may be formed as a protrusion 15a, or a protrusion 15a is provided as shown in FIG. 4C. There may be no form. Further, in FIG. 4, what is indicated by reference numeral 15 is the lower end surface of the protruding portion 15, and the root of the protruding portion 15 is not shown.

  Here, the perspective view of FIG. 1, the longitudinal sectional view of FIG. 2, the longitudinal sectional view of FIG. 3, and the plan view of FIG. 4 do not show the actual state of the mask 1 but schematically show it. ing. Further, the opening dimension of the through-hole 12 and the thickness dimension of the mask main body 10 and the like in FIG. 1 and the like are shown in such dimensions for the convenience of drawing.

  The operation of arranging the solder balls 2 using the mask 1 is performed in the following procedure. This arrangement work is performed by a dedicated arrangement apparatus (see FIGS. 1 and 5 of Patent Document 1). First, a flux 17 (see FIG. 2) is printed on the electrode 6 of the work 3. Next, after aligning the mask 1 on the work 3 so that the through-hole 12 and the electrode 6 coincide with each other, the mask 1 is fixed. Such alignment work is actually performed by aligning the workpiece 3 with the outer peripheral edge of the mask body 10 or an alignment mark (not shown) formed on the mask body 10. When the alignment operation is completed, the magnetic force of a magnet (not shown) disposed below the work 3 is applied, and the lower end surface of the projection 15 abuts against the surface of the work 3 in such a fixed state. Is held in a separated posture in which a gap facing the workpiece 3 as shown in FIGS. 2 and 3 is secured. Even when the surface of the workpiece 3 is slightly wavy, the mask main body 10 is inseparably integrated so that the lower end surface of the projection 15 is brought into contact with the surface of the workpiece 3 to match the waviness of the surface of the workpiece 3. Can be fixed.

  Next, a large number of solder balls 2 are supplied onto the mask 1, the solder balls 2 are dispersed on the mask 1 using a squeegee brush, and the solder balls 2 are put into the through holes 12 one by one. As a result, the solder ball 2 is adhered and held to the flux 17 in a temporarily fixed shape. In the charging operation of the solder ball 2 using such a squeegee brush, even if the squeegee brush pressure is applied to the mask 1, the mask 1 can be prevented from being bent by the projections 15, and the charging operation can be performed smoothly and efficiently. Can do.

  According to the mask 1 having such a configuration, since the projection 15 that forms the opposing gap between the mask main body 10 and the workpiece 3 is provided, the opposing gap with the workpiece 3 can be reliably secured by the projection 15, and the through-hole 12 can be secured. It is possible to efficiently carry out the operation of putting the solder ball 2 into the inside without leakage.

  Further, a reinforcing frame 11 can be provided on the outer peripheral edge of the mask body 10, and the mask body 10 is formed in a state where a tension is applied to the mask body 10 so that stress in a direction in which the mask body 10 contracts inwardly acts. For example, the expansion of the mask main body 10 due to the change in the ambient temperature can be absorbed by the tension in the contraction direction. Thereby, it is possible to prevent the positional deviation of the mask main body 10 with respect to the workpiece 3. In addition, since uniform tension can be applied to the entire mask body 10, the solder balls 2 can be mounted on the workpiece 3 with high positional accuracy.

  Next, a method for manufacturing the array mask 1 having such a configuration is shown in FIGS. First, for example, a photoresist layer 31 is formed on the surface of a matrix 30 made of stainless steel or brass having conductivity. The photoresist layer 31 was formed by laminating one or several negative photosensitive dry photoresists to a predetermined height and then thermocompression bonding. Next, as shown in FIG. 5A, a pattern film (glass mask) 32 having a light transmitting hole 32 a corresponding to the protrusion 15 is brought into close contact with the photoresist layer 31, and then an ultraviolet lamp 33 is used for ultraviolet rays. Exposure is performed by irradiating light, development and drying are performed, and unexposed portions are dissolved and removed, thereby corresponding to the tapered protrusions 15 as shown in FIG. A primary pattern resist 34 having a resist body 34 a was formed on the mother die 30. At this time, it is preferable that the resist body 34a has a taper by using a photoresist that does not easily transmit ultraviolet rays or by reducing the exposure amount.

  Subsequently, the mother die 30 is put in an electroforming tank bathed under a predetermined condition, and as shown in FIG. 5C, the resist member 34a of the mother die 30 is within the range of the height of the previous resist member 34a. A primary electroformed layer 35 was formed by electroforming an electrodeposited metal such as nickel or copper on the surface not covered with. Here, the primary electroformed layer 35 was formed over substantially the entire surface of the mother die 30 (first electroforming process). Next, as shown in FIG. 5D, the primary pattern resist 34 is removed. Here, it is preferable to polish the surface of the primary electroformed layer 35.

  Next, as shown in FIG. 6A, a photoresist layer 36 is formed on the entire surface of the primary electroformed layer 35 and the mother die 30, and then the through hole 12 is formed on the surface of the photoresist layer 36. After closely attaching a pattern film (glass mask) 37 having a corresponding light transmitting hole 37a, exposure is performed by irradiating with ultraviolet light with an ultraviolet lamp 33, and development and drying are performed, and an unexposed portion is exposed. By dissolving and removing, a secondary pattern resist 38 having a resist body 38 a corresponding to the mask body 10 was formed on the surface of the primary electroformed layer 35 as shown in FIG.

  Subsequently, it is placed in an electroforming tank bathed under a predetermined condition, and as shown in FIG. 6C, it is covered with the matrix 30 and the resist body 38a within the range of the height of the previous resist body 38a. A secondary electroformed layer 39 was formed by electroforming an electrodeposited metal such as nickel or copper on the surface of the primary electroformed layer 35 that was not present (second electroforming step). Next, the secondary pattern resist 38 is dissolved and removed, and then the secondary electroformed layer 39 is peeled off from the mother die 30 and the primary electroformed layer 35, whereby a mask as shown in FIG. 6 (d) and FIG. 1 was obtained. If the frame 11 is attached to the mask 1, an array mask 1 as shown in FIG. 1 is obtained.

  The secondary electroformed layer 39, that is, the mask 1, can be held on the frame body 11 in a state where a tension is applied so that a stress in the direction of shrinking inward acts on the secondary electroformed layer 39. The stress is applied by, for example, using the difference in thermal expansion coefficient between the frame 11 and the mask 1 to perform the mounting work of the frame 11 on the outer peripheral edge of the mask 1 in a high temperature environment. This can be realized by contracting the inward side.

  According to the manufacturing method of the mask 1 as described above, the arraying mask can be manufactured with high accuracy by the electroforming method, so that the solder balls 2 can be mounted on the workpiece 3 with high positional accuracy. If the mask 1 having the protrusions 15 is formed so as to be inseparably integrated by a single electroforming operation (second electroforming process), the protrusions 15 are damaged as compared with the case where the protrusions 15 are retrofitted. This is also excellent in that the mask 1 having excellent reliability can be obtained with high accuracy. Further, if the protrusion 15 is formed in a tapered shape so as to increase as it approaches the lower surface of the mask body 10, it is possible to avoid stress concentration on the root (base) of the protrusion 15, and thus the protrusion 15. Since the protrusion 15 can be brought into contact with the electrodes 6 in a state of being separated from the electrode 6 to which the flux 17 is applied, the flux 17 applied to the electrode 6 adheres to the mask body 10. Therefore, mounting failure of the solder ball 2 can be prevented. At this time, it becomes more effective by setting the ratio of the diameter of the tip of the protrusion 15 to the diameter of the root to be 1: 3 or more and setting the aspect ratio of the protrusion 15 to be 3 or more.

  Further, the protrusion 15 having a desired aspect ratio can be easily obtained by adjusting the resist pattern. In the mask 1 having such a configuration, the shapes of the through holes 12 and the protrusions 15 may be straight or tapered. Such a shape can be obtained by changing the photosensitivity and exposure conditions of the photoresist layers 31 and 36.

  Further, as shown in FIG. 7, the protruding portion 15 has a diverging shape whose size increases as it approaches the lower surface of the mask, and the side surface (particularly the base portion) of the protruding portion 15 may have an arc shape. As a result, it is possible to prevent breakage caused by stress concentration, particularly at the base of the protrusion 15, and to prevent the flux 17 from entering the through hole 12.

(First embodiment)
Next, the arrangement mask according to the first embodiment will be described. In addition, the same code | symbol is attached | subjected to the member same as the said structure, and the description is abbreviate | omitted.

  In the mask 1 having the above configuration, one solder ball 2 is put into the through hole 12 formed in the mask main body 10. Here, for example, when bumps of two different heights are formed on the workpiece 3, after the flux printing, a mask 1A having through holes 12A into which the solder balls 2A (small balls) to be the bumps A can be inserted is firstly mounted. 3, the solder balls 2 </ b> A are put into the through holes 12 </ b> A, and then the mask 1 </ b> B having the through holes 12 </ b> B into which the solder balls 2 </ b> B (large balls) to be the bumps B can be inserted is placed on the work 3. Then, the solder balls 2B were put into the through holes 12B and heated and melted (the bumps A and B, the solder balls 2A and 2B, the through holes 12A and 12B, and the masks 1A and 1B were not shown). As described above, in order to obtain bumps having different desired heights on the work 3, masks and processes corresponding to the number of different bump types are required.

  In order to solve the above problem, the mask 1 according to this embodiment is shown in FIG. 8 (FIG. 8A is a partial plan view of the mask for arrangement according to this embodiment, and FIG. 8B is a sectional view thereof. ), Through holes 12 corresponding to the arrangement pattern of the electrodes 6 of the respective semiconductor chips 5 on the work 3 are provided. The through holes 12 have a single through hole 13 and a plurality of the single through holes 13 connected to each other. And a continuous through hole 14. The single through-hole 13 is formed in a circular shape in plan view, and the continuous through-hole 14 is formed in a darling shape or gourd shape in plan view in which two single through-holes 13 are connected. One solder ball 2 can be inserted, and two solder balls 2 can be inserted into the continuous through hole 14. Here, for example, when the solder ball 2 having a diameter of 200 μm is mounted on the electrode 6 having a diameter of 150 μm by using the mask 1 having such a configuration, the height of the bump is as shown in FIG. The bump height L1 in the single through hole 13 with one inserted was 172 μm, and the bump height L2 in the continuous through hole 14 with two solder balls 2 inserted was 230 μm. At this time, the flux 17 is preferably printed in an elliptical shape on the workpiece 3 so that the solder balls 2 inserted into the continuous through holes 14 are not separated.

  In addition, the continuous through-hole 14 may be comprised by the number of the single through-holes 13 connected 3 or more. At this time, it may be formed by connecting three or more single through holes 13 linearly, or a so-called plane formed by connecting three or more single through holes 13 in a circumferential shape around a certain point. A clover-shaped one may be used. However, for example, when the continuous through-hole 14 has a shape (three-leaf clover shape) in which three single through-holes 13 are arranged in a circle, the shape shown in FIG. Since the solder ball 2 is inserted into the center of the single through hole 13 and the solder ball 2 cannot be inserted into each single through hole 13 constituting the continuous through hole 14, as shown in FIG. 9B. It is preferable that the continuous portion of the single through holes 13 as the continuous through holes 14 is small. Moreover, as shown in FIG.9 (c), the continuous through-hole 14 may be formed in a row so that the circumference | surroundings of each single through-hole 13 which comprises this may contact | connect. Here, the shape of the continuous through hole 14 is preferably formed so that the electrode 6 is positioned at the center thereof as shown in FIGS. 8, 9B, and 9C. Moreover, it is preferable that the dimension of one single hole 13 constituting the continuous hole 14 is larger than the dimension of the electrode 6. When the mask 1 is viewed from above, the width of the continuous through hole 14 (single through hole 13), the solder ball 2, the flux 17, and the electrode 6 is as follows: continuous through hole 14 (single through hole 13)> solder ball 2> flux. 17> It is preferable that the relationship of the electrode 6 is satisfied.

  As described above, by preparing the mask 1 having the above-described configuration and performing the mounting operation of the solder ball 2, bumps having different desired heights can be formed on the work 3, and thus a plurality of types of masks are prepared. This eliminates the need for cost and lead time. The height of the bump can be easily adjusted and set according to the shape and size of the through holes 12, that is, the single through holes 13 and the continuous through holes 14, and the number of the single through holes 13 constituting the continuous through holes 14. And a bump having a desired height can be obtained. Also, the height of the bump can be adjusted and set according to the shape and dimensions of the electrode 6. In addition, as a method of forming the single through hole 13 and the continuous through hole 14 having a desired shape, in the process of forming the secondary pattern resist shown in FIG. 6B, the single through hole 13 and the continuous through hole 14 having the desired shape. Can be easily obtained by forming the resist body 38a corresponding to the above.

(Second Embodiment)
Next, an array mask according to the second embodiment will be described. In addition, the same code | symbol is attached | subjected to the member same as the said structure, and the description is abbreviate | omitted.

  In the mask 1 having the above-described configuration, as shown in FIGS. 2 and 3, the mask 1 is fixed (positioned) on the work 3 by applying a magnetic force of a magnet (not shown) disposed in the work 3 or below the work 3. However, although the pattern region of the mask main body 10 is formed with the through-holes 12 constituting the mask body 10, there is no through-hole 12 on the outer periphery of the pattern region, and the mask 1 is magnetized ( When the magnetic field is placed on the work 3 on which the pattern area (not shown) is placed, the magnetic force acts more strongly on the outer periphery of the pattern area than the pattern area. In particular, when the work 3 is a substrate, the waviness of the mask 1 appears remarkably. As a result, the pattern pitch of each pattern region is shifted, resulting in mounting failure of the solder balls 2.

In order to solve the above problem, the mask 1 according to the present embodiment is provided with a pitch adjusting unit 50 on the outer periphery of the pattern region including the through holes 12. Specifically, as shown in FIG. 10, the pitch adjusting unit 50 is configured by providing openings 51 between a plurality of formed pattern regions. As described above, by providing the pitch adjusting portion 50 (opening 51) between the pattern areas, the action of the magnetic force between the pattern areas is weakened, and it is possible to prevent the mask 1 from being swelled. Can be mounted with high accuracy. In addition to this, if tension is applied in the plane direction of the mask 1, the occurrence of waviness of the mask 1 can be suppressed more effectively, which can contribute to mounting of the solder balls 2 with high accuracy. Furthermore, if the opening 51 is mesh-shaped, it can be provided with a function rich in extensibility, so that the shift of the pitch of each pattern region can be adjusted, and the pattern pitch accuracy of each pattern region becomes good, The mask 1 can be placed on the workpiece 3 with good followability. When the pitch adjusting unit 50 is configured by such mesh-shaped openings 51, as shown in FIG. In the case where the pitch adjusting unit 50 is provided by the openings 51, the aperture ratio between the pattern areas is preferably 10 to 90%. In the present embodiment, the aperture ratio is 40%, but the aperture ratio between the pattern areas is the pattern. The aperture ratio in the region may be about the same as or higher than that. Moreover, as the magnitude | size of the tension | tensile_strength made to act on the plane direction of the mask 1, the range of 0.5-2.0 kg / cm < ² > is preferable.

  The pitch adjusting unit 50 may have a configuration in which the concave portion 52 is provided between adjacent pattern regions. Specifically, as shown in FIG. 12, the thickness of the mask body 10 between adjacent pattern regions is formed to be smaller than the thickness of the mask body 10 in the pattern regions. Even with such a configuration, it is possible to reduce the effect of the magnetic force between the pattern regions, to prevent the mask 1 from waviness, and to mount the solder ball 2 at a desired position with high accuracy. Of course, the pitch adjusting unit 50 may be a combination of the opening 51 and the recessed part 52. As described above, the magnitude of the magnetic force applied between the pattern regions can be easily adjusted by the shape, position, and number of openings and recesses.

  Here, the pitch adjusting unit 50 is preferably constituted by a plurality of openings 51, and the openings 51 are preferably shaped and dimensioned so that the solder balls 2 cannot be inserted therethrough. Further, when the pitch adjusting portion 50 is provided by the recess 52, it is preferable to provide the mask body 10 (mask 1) on the surface facing the work 3, but the recess 52 is provided on the solder ball 2 of the mask body 10 (mask 1). When it is provided on the supply side, it can function as a solder ball retention part. In addition, as a method of forming the opening 51, in the step of forming the secondary pattern resist shown in FIG. 6B, a resist different from the resist body 38a is formed at a position corresponding to the outer periphery of the pattern region (between the pattern regions). It is easily obtained by forming a body. In addition, as a method of forming the recess 52, the mask 1 shown in FIG. 6D can be easily obtained by etching at a position corresponding to the outer periphery of the pattern region (between the pattern regions).

  In each of the above-described configurations, the mask 1 is integrally formed with the protrusion 15, but the protrusion 15 may be formed integrally with another member. In the mask 1, for example, if the mask body 10 is formed of a magnetic material such as iron or nickel and the protrusion 15 is formed of a non-magnetic material such as copper or aluminum, a magnet (not shown) as described above. When the mask 1 is fixed to the work 3 by the magnetic attraction force, the magnetic force acts uniformly on the mask 1, so that the mask 1 is not inadvertently bent, and the through holes 12 for the electrodes 6 are not bent. Position accuracy can be improved.

  Further, in the case where the protrusion 15 is formed of a non-magnetic material, it is not limited to metal but may be formed of resin. According to this, the cushion action derived from the elasticity of the resin is exhibited, and the possibility that the work 3 is damaged when the protrusion 15 contacts the work 3 is reduced. In order to achieve this effect remarkably, in the mask 1, it is preferable that all the protrusions 15 that come into contact with the workpiece 3 are made of resin. As a result, the magnetic force acts uniformly on the mask 1, so that the mask 1 is not inadvertently bent and the positional accuracy of the through-hole 12 with respect to the electrode 6 can be improved.

  Further, the shape of the lower end surface of the protrusion 15 is not limited to a circle, and may be an ellipse or a polygon such as a square, a rhombus, or a hexagon. Furthermore, it is preferable that the corners constituting these shapes and the boundary portion between the lower end surface and the side surface of the protrusion 15 have an R shape. Accordingly, for example, when the surface of the mask 1 where the protrusion 15 is formed can be cleaned, the cleaning can be performed smoothly, and the cleaning means and the protrusion due to the cleaning means (cloth, sponge, etc.) being caught by the protrusion 15. The risk of damage to 15 can be prevented as much as possible.

DESCRIPTION OF SYMBOLS 1 Mask for arrangement | sequence 2 Solder ball 3 Workpiece 6 Electrode 10 Mask main body 12 Through-hole 13 Single through-hole 14 Continuous through-hole 15 Protrusion part 15a Protrusion part 15b Protrusion part 30 Master mold 31 Photoresist layer 34 Primary pattern resist 35 Primary electroformed layer 36 Photoresist layer 38 Secondary pattern resist 39 Secondary electroformed layer 50 Pitch adjusting part 51 Opening 52 Recessed part

Claims (5)

A through hole (12) corresponding to a predetermined arrangement pattern is provided, and the solder ball (2) is mounted at a predetermined position on the work (3) by swinging the solder ball (2) into the through hole (12). A mask for the array,
The through hole (12) includes a Tantsuana (13), possess a continuous hole (14), the continuous hole (14), a plurality of the single hole (13) is next in plan view An array mask, wherein the masks are formed so as to match each other, and a part of the adjacent single through holes (13) overlap each other . 2. The array mask according to claim 1, wherein the continuous through holes (14) are formed by connecting a plurality of the single through holes (13) linearly in a plan view . 3. The arrangement mask according to claim 2 , wherein the continuous through holes (14) are formed in a daruma shape in a plan view . The continuous holes (14), the sequence mask according to claim 1, wherein a plurality of said single hole (13) is made form in sleep with the circumferential shape in a plan view.   A method for forming solder bumps, wherein solder bumps having different heights are formed at predetermined positions on the workpiece (3) using the array mask according to any one of claims 1 to 4.

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