JP6636118B2 - Mask for arranging solder balls and method of manufacturing the same - Google Patents

Description

  The present invention relates to an arrangement mask having a through hole for a ball corresponding to a predetermined arrangement pattern, and mounting a solder ball at a predetermined position on a work by transferring a solder ball into the through hole for a ball.

  In the present invention, an arrangement mask can be formed by an electroforming method. The formation of the arrangement mask by an electroforming method itself is disclosed in, for example, Patent Document 1, and is well known.

  The mask for arranging solder balls described in Patent Document 1 has a flat mask body 10 having a large number of ball through holes 12 corresponding to a predetermined arrangement pattern, and a work 3 protruding from the lower surface of the mask body 10. And a support protrusion 15 for securing a gap facing the support. The support projection 15 includes an anchor portion 20 embedded and fixed in a holder portion 16 formed on the mask main body 10 and a pillar portion 21 connected to the anchor portion 20 and protruding from the lower surface of the mask main body 10. And The mask body 10 and the support protrusions 15 are formed by an electroforming method.

JP 2010-50169 A

  In this type of mask for arranging solder balls, a mask is formed by forming a resist body corresponding to a ball through hole on a matrix and then electroforming an electrodeposited metal on the matrix between the resist bodies. Forming the body. For this reason, if it is attempted to form a mask having a small pitch interval between the ball through-holes in response to the narrowing of the pitch of the electrodes on the work, the distance between adjacent resist members on the matrix becomes small, and these resist members are formed. Since the surface area of the matrix exposed between them becomes small, it is difficult to increase the thickness of the electrodeposited metal on the matrix and increase the thickness of the mask body.

  As described above, in the conventional mask for arranging solder balls and the method of manufacturing the same, in order to cope with the narrow pitch of the through holes, the thickness dimension of the mask body must be reduced, and as a result, the strength of the mask body is reduced. There was a new problem of shortage.

  An object of the present invention is to provide a solder ball arrangement mask, which has necessary and sufficient structural strength, has a through hole for a ball at a narrower interval corresponding to the narrow pitch of electrodes on a work, and It is to provide a manufacturing method thereof.

  A solder ball suction mask in which a large number of suction through holes 12 for vacuum suction of the solder balls 3 are independently provided in the mask body 11, and the mask body between the suction through holes 12 is provided. A reinforcing projection 13 for enhancing the structural strength is formed integrally with the mask body 11 on the lower surface side of the mask body 11 so as to protrude downward.

  The reinforcing protrusions 13 can be formed in a square lattice shape surrounding each suction through hole 12.

  The lower surface of the suction mask 6 is formed in a stepped shape including an inner bottom surface 41 of the cell recess 15 formed so as to surround each suction through hole 12 and a flat surface 40 located below the inner bottom surface 41. Thus, a configuration in which the reinforcing protrusion 13 having the flat surface 40 is formed in a projecting shape so as to surround the cell recess 15 can be adopted.

  A configuration in which a conical reinforcing protrusion 13 is formed adjacent to each suction through hole 12 can be adopted.

  According to the present invention, a large number of ball through-holes 62 are independently provided in the mask main body 61 in a vertically penetrating manner. A solder ball arrangement mask for mounting the solder balls 3 is targeted. On the lower surface side of the mask main body 61, a reinforcing projection 63 for enhancing the structural strength is formed integrally with the mask main body 61 in a state of protruding downward.

  A configuration in which a guide concave portion 66 for guiding the solder ball 3 placed on the upper surface of the mask main body 61 to the ball through-hole 62 corresponding to the reinforcing protrusion 63 can be adopted.

  A configuration in which the reinforcing projections 63 are formed in a square lattice shape surrounding each ball through hole 62 can be adopted.

  A large number of suction through-holes 12 for vacuum suction of the solder balls 3 are independently provided in the mask main body 11 formed by the electroforming method in a vertically penetrating manner. A method for manufacturing a solder ball suction mask, wherein a reinforcing projection 13 for enhancing structural strength is formed on a lower surface side and is integrally formed with the mask main body 11 by electroforming in a state of protruding downward. Forming a primary pattern resist 26 having a resist opening 25 on the surface of the conductive matrix 20 corresponding to the position of the suction through-hole 12; and setting the height of the primary pattern resist 26 on the matrix 20. A primary electroforming step of electroforming an electrodeposited metal to form a primary electroforming layer 28 having a lattice-like groove 27 on the upper surface of the primary pattern resist 26 surrounded by the resist opening 25; Absorption through hole on top Forming a secondary pattern resist 34 having a resist projection 33 corresponding to 2 and electroforming an electrodeposited metal on the primary electroformed layer 28 within a range not exceeding the height of the resist projection 33, A secondary electroforming step for forming the secondary electroformed layer 35, the secondary electroformed layer 35 is peeled off from the primary electroformed layer 28 and the matrix 20, and the primary and secondary pattern resists 26 and 34 are removed. Thus, a step of obtaining a mask for suction as the secondary electroformed layer 35 is included. Further, in the secondary electroforming step, the reinforcing projections 13 are formed so as to correspond to the lattice-shaped grooves 27 formed in the primary electroformed layer 28.

  A large number of suction through-holes 12 for vacuum suction of the solder balls 3 are independently provided in the mask main body 11 formed by the electroforming method in a vertically penetrating manner. A method for manufacturing a solder ball suction mask, wherein a reinforcing projection 13 for enhancing structural strength is formed on a lower surface side and is integrally formed with the mask main body 11 by electroforming in a state of protruding downward. Forming a primary pattern resist 26 having a resist opening 25 on the surface of the conductive matrix 20 corresponding to the position of the suction through-hole 12; and setting the height of the primary pattern resist 26 on the matrix 20. A primary electroforming step of electroforming an electrodeposited metal to form a primary electroformed layer 28 on the upper surface of the primary pattern resist 26 surrounding the resist opening 25; Corresponding resist Forming a secondary pattern resist 34 having a portion 33, and electroforming an electrodeposited metal on the primary electroformed layer 28 so as not to exceed the height of the resist projection 33, thereby forming a secondary electroformed layer 35. A secondary electroforming step of forming the secondary electroformed layer 35 and the primary and secondary pattern resists 26 and 34 while removing the secondary electroformed layer 35 from the primary electroformed layer 28 and the matrix 20. Obtaining a suction mask that is the casting layer 35. In the primary electroforming step, the electrodeposition is completed before the electrodeposited metals grown from the respective resist openings 25 are brought into contact with each other on the upper surface of the primary pattern resist 26, and the primary electrodeposition is performed at an equal distance from the adjacent resist openings 25. An exposed portion 42 where the primary pattern resist 26 appears is formed in a part of the upper surface of the pattern resist 26, and a concave groove 43 is formed in the primary electroformed layer 28 corresponding to the exposed portion 42. It has become so. Then, in the secondary electroforming step, the reinforcing projections 13 having the flat surface 40 are formed corresponding to the concave grooves 43 formed in the primary electroformed layer.

  A large number of suction through-holes 12 for vacuum suction of the solder balls 3 are independently provided in the mask main body 11 formed by the electroforming method in a vertically penetrating manner. A method for producing a suction mask, wherein a reinforcing projection 13 for enhancing structural strength is formed integrally with the mask main body 11 by electroforming in a state protruding downward on a lower surface side, the method comprising: Forming a primary pattern resist 50 having a resist protrusion 49 on the surface of the matrix 20 corresponding to the formation position of the reinforcing protrusion 13; A primary electroforming step of electroforming the deposited metal to form a primary electroformed layer 52 having a conical depression 51 on the upper surface of the resist convex portion 49, and a process corresponding to the adsorption through hole 12 on the primary electroformed layer 52. Putter having resist convex portion 33 A step of forming a resist 34, and a second electroforming step of forming a second electroformed layer 35 by electroforming an electrodeposited metal on the first electroformed layer 52 within a range not exceeding the height of the resist projection 33. The step, the secondary electroformed layer 35 is peeled off from the primary electroformed layer 52 and the matrix 20, and the primary and secondary pattern resists 50 and 34 are removed, so that the secondary electroformed layer 35 Obtaining a mask. Then, in the secondary electroforming step, the conical reinforcing protrusions 13 are formed corresponding to the conical recesses 51 formed in the primary electroformed layer 52.

  According to the present invention, a large number of ball through-holes 62 are independently provided in a vertically penetrating manner in a mask main body 61 formed by an electroforming method, and the solder balls 3 are transferred into the ball through-holes 62. A mask for mounting the solder balls 3 at predetermined positions on the substrate 1. Reinforcing projections 63 for enhancing structural strength project downward from the lower surface of the mask body 61 between the ball through holes 62. The present invention is directed to a method of manufacturing a mask for arranging solder balls integrally formed with the mask main body 61 by electroforming in a state. Forming a primary pattern resist 76 having a resist opening 75 between adjacent ball through holes 62 on the surface of the conductive matrix 70, and a height of the primary pattern resist 76 on the matrix 70; A primary electroforming step of electroforming an electrodeposited metal to form a primary electroforming layer 78 having a lattice-like groove 77 between the primary pattern resists 76 surrounded by the resist openings 75; Forming a secondary pattern resist 84 having a resist convex portion 83 corresponding to the ball through-hole 62 on the casting layer 78; and forming the secondary pattern resist 84 on the primary electroformed layer 78 within a range not exceeding the height of the resist convex portion 83. A secondary electroforming step of electroforming the electrodeposited metal to form a secondary electroformed layer 85; separating the secondary electroformed layer 85 from the primary electroformed layer 78 and the matrix 70; Removing the pattern resists 76 and 84 In, and a step of obtaining a secondary electroformed layer 85 serving as a suction mask. Further, in the secondary electroforming step, the reinforcing projections 63 are formed so as to correspond to the lattice-like grooves 77 formed in the primary pattern resist 76.

  In the solder ball suction mask, for example, a reinforcing projection 13 for enhancing the structural strength is formed on the lower surface side of the mask body 11 between the suction through holes 12 by electroforming so as to protrude downward. It was formed integrally with the main body 11. According to this, combined with the fact that the reinforcing projections 13 are formed integrally with the mask main body 11, the vertical thickness of the suction mask 6 is increased by the amount of protrusion of the reinforcing projections 13, and Strength can be increased. Therefore, for example, even when a large load is applied to the center of the board surface of the suction mask 6 by vacuum-sucking the solder balls 3, the suction mask 6 is effectively prevented from bending and deforming. The solder ball 3 can be accurately placed on the predetermined position, which contributes to the higher precision of the bump electrode.

  In addition, by providing the reinforcing protrusions 13 in this manner, the strength of the suction mask 6 can be increased, and thus the pitch of the suction through holes 12 in the mask main body 11 is reduced. A necessary and sufficient structural strength can be given to the suction mask 6 by compensating for the reduction in strength. As described above, it is possible to obtain the suction mask 6 suitable for narrowing the pitch of the electrodes 2 on the substrate 1. The solder ball suction mask according to the present invention can be formed by an electroforming method or an etching method. However, it is possible to form a hole having a diameter dimension equal to or less than the plate thickness, and to easily control the plate thickness by the electroforming method. Preferably, it is formed.

  When the reinforcing projections 13 are formed in a square lattice shape surrounding each of the suction through holes 12, the entire circumferential direction of the suction through holes 12 can be surrounded by the reinforcing projections 13, so that the structural strength of the suction mask 6 can be reduced. It can be significantly improved.

  The lower surface of the suction mask 6 is formed in a stepped shape including an inner bottom surface 41 of the cell recess 15 formed so as to surround each suction through hole 12 and a flat surface 40 located below the inner bottom surface 41. Thus, a configuration in which the reinforcing protrusion 13 having the flat surface 40 is formed in a protruding manner so as to surround the cell recess 15 can be adopted. According to this, the thickness of the reinforcing projections 13 in the horizontal direction can be increased, so that the strength of the reinforcing projections 13 can be increased, and a marked improvement in the structural strength of the suction mask 6 can be expected.

  A configuration in which a conical reinforcing protrusion 13 is formed adjacent to each suction through hole 12 can be adopted. Also in this case, in conjunction with the fact that the reinforcing projections 13 are formed integrally with the mask main body 11, the thickness of the suction mask 6 in the vertical direction is increased by the amount of protrusion of the reinforcing projections 13, and the strength of the suction mask 6 is increased. Can be up.

  In the mask for arranging solder balls according to the present invention, reinforcing projections 63 for enhancing the structural strength are projected downward on the lower surface side of the mask main body 61 between the ball through holes 12 by, for example, electroforming. In this state, it was formed integrally with the mask body 61. According to this, in conjunction with the fact that the reinforcing projections 63 are formed integrally with the mask body 61, the vertical thickness of the arrangement mask 60 is increased by the amount of the protrusions of the reinforcement projections 63, and Strength can be increased. In a state in which the arrangement mask 60 is fixed on the substrate 1, the reinforcing protrusions 63 serve as support protrusions for securing an opposing interval with the substrate 1 by contacting the lower end thereof to the surface of the substrate 1. Also plays a role. Therefore, for example, even when a large number of solder balls 3 are placed on the upper surface of the arrangement mask 60 and a large load acts on the arrangement mask 60, the arrangement mask 60 is effectively prevented from being bent and deformed. As a result, the solder balls 3 can be accurately placed at predetermined positions on the substrate 1, which contributes to higher accuracy of the bump electrodes.

  In addition, by providing the reinforcing protrusions 63, the strength of the arrangement mask 60 can be increased. Therefore, the strength of the arrangement mask 60 due to the narrow pitch interval of the ball through-holes 62 in the mask body 61 is reduced. The necessary and sufficient structural strength can be provided to the alignment mask 60 by compensating for the reduction. As described above, an arrangement mask 60 suitable for narrowing the pitch of the electrodes 2 on the substrate 1 can be obtained. The mask for arranging solder balls according to the present invention can be formed by an electroforming method or an etching method, but it is possible to form a hole having a diameter dimension equal to or less than the plate thickness, and to easily control the plate thickness by the electroforming method. Preferably, it is formed.

  When a guide concave portion 66 for guiding the solder ball 3 placed on the upper surface of the mask main body 61 to the ball through hole 62 is formed corresponding to the reinforcing protrusion 63, the guide concave portion 66 allows the mask main body 61 to be formed. Since the solder balls 3 placed on the upper surface can be moved and guided toward the ball through-holes 62, the solder balls 3 can be quickly dropped into the ball through-holes 62. Work efficiency can be improved. Further, since the solder balls 3 can be moved and guided to the ball through-holes 62 by the guide recesses 66, the solder balls 3 can be dropped into the respective ball through-holes 62 more reliably. Balls of the solder balls 3 do not easily fall into the holes 62, and an arrangement mask 60 having excellent reliability can be obtained.

  If the reinforcing projections 63 are formed in a square lattice shape surrounding each ball through-hole 62, the entire circumferential direction of the ball through-hole 62 can be surrounded by the reinforcing projection 63. The strength can be significantly improved.

  In the manufacturing method of the solder ball suction mask, the reinforcing projections 13 are formed in the secondary electroforming step so as to correspond to the lattice-shaped grooves 27 formed in the primary electroformed layer 28. In the secondary electroforming step, both the mask body 11 and the reinforcing projections 13 can be formed integrally. As described above, since the suction mask in which the mask body 11 and the reinforcing projection 13 are integrally formed can be obtained by one process, the manufacturing process can be simplified, and the reinforcing projection 13 is formed. Accordingly, it is possible to suppress an increase in the number of manufacturing steps and an increase in the manufacturing cost of the mask.

  Similarly, in the primary electroforming step, the electrodeposition is completed before the electrodeposited metals grown from the respective resist openings 25 are brought into contact with each other on the upper surface of the primary pattern resist 26, and the electrodeposition is performed at an equal distance from the adjacent resist openings 25. An exposed portion 42 where the primary pattern resist 26 appears is formed on a part of the upper surface of the located primary pattern resist 26, and a groove 43 is formed in the primary electroformed layer 28 corresponding to the exposed portion 42. Is formed, and in the secondary electroforming step, a configuration in which the reinforcing protrusion 13 having the flat surface 40 is formed corresponding to the concave groove 43 formed in the primary electroformed layer may be adopted. it can. Also in this case, it is possible to obtain a suction mask in which the mask main body 11 and the reinforcing projection 13 are integrally formed in one step, so that the manufacturing process can be simplified and the reinforcing projection 13 can be formed. This can suppress an increase in the number of manufacturing steps caused by this, and can suppress an increase in the manufacturing cost of the mask.

  Similarly, in the primary electroforming step, a primary electroforming layer 52 having a conical depression 51 is formed on the upper surface of the resist projection 49, and in the secondary electroforming step, the primary electroforming layer 52 is formed. A configuration in which the conical reinforcing projections 13 are formed corresponding to the conical recesses 51 formed in the 52 can be adopted. Also in this case, it is possible to obtain a suction mask in which the mask main body 11 and the reinforcing projection 13 are integrally formed in one step, so that the manufacturing process can be simplified and the reinforcing projection 13 can be formed. This can suppress an increase in the number of manufacturing steps caused by this, and can suppress an increase in the manufacturing cost of the mask.

  In the method for manufacturing a mask for arranging solder balls according to the present invention, in the secondary electroforming step, the reinforcing protrusions 63 are formed so as to correspond to the lattice-shaped grooves 77 formed in the primary electroformed layer 78. Therefore, both the mask main body 61 and the reinforcing projection 63 can be formed integrally in the secondary electroforming step. As described above, in one process, an alignment mask in which the mask main body 61 and the reinforcing protrusion 63 are integrally formed can be obtained, so that the manufacturing process can be simplified and the reinforcing protrusion 63 is formed. Accordingly, it is possible to suppress an increase in the number of manufacturing steps and an increase in the manufacturing cost of the mask.

It is a vertical side view of the mask for adsorption of the solder ball of the 1st form. It is a vertical side view which shows typically the suction head to which the mask for suction is applied. It is a bottom view of the mask for adsorption of a 1st form. (A)-(c) is process explanatory drawing of the manufacturing process of the mask for adsorption | suction of 1st form. (A), (b) is process explanatory drawing of the manufacturing process of the mask for adsorption | suction of 1st form. (A), (b) is process explanatory drawing of the manufacturing process of the mask for adsorption | suction of 1st form. It is a vertical side view of the mask for adsorption of the solder ball of the 2nd form. It is a bottom view of the mask for adsorption of a 2nd form. (A)-(c) is process explanatory drawing of the manufacturing process of the suction mask of 2nd form. It is a longitudinal section side view of the mask for adsorption of the solder ball of the 3rd form. It is a bottom view of the mask for adsorption of a 3rd form. (A)-(c) is process explanatory drawing of the manufacturing process of the suction mask of 3rd form. (A), (b) is process explanatory drawing of the manufacturing process of the suction mask of 3rd form. (A), (b) is process explanatory drawing of the manufacturing process of the suction mask of 3rd form. FIG. 2 is a longitudinal sectional side view of the mask for arranging solder balls according to the first embodiment of the present invention. (A) is a bottom view of the arrangement mask according to the first embodiment, and (b) is a plan view of the arrangement mask. 4A to 4C are process explanatory diagrams of a manufacturing process of the arrangement mask according to the first embodiment. 7A and 7B are process explanatory diagrams of a manufacturing process of the arrangement mask according to the first embodiment. 7A and 7B are process explanatory diagrams of a manufacturing process of the arrangement mask according to the first embodiment. It is a longitudinal side view of the mask for arrangement of solder balls concerning a 2nd example of the present invention. (A), (b) is process explanatory drawing of the manufacturing process of the arrangement | positioning mask which concerns on 2nd Example. FIG. 9 is a vertical sectional side view of a mask for arranging solder balls according to a third embodiment of the present invention. It is a bottom view of the mask for arrangement concerning a 3rd example. (A)-(c) is process explanatory drawing of the manufacturing process of the mask for arrangement which concerns on 3rd Example. (A), (b) is process explanatory drawing of the manufacturing process of the mask for arrangement which concerns on 3rd Example. (A), (b) is process explanatory drawing of the manufacturing process of the mask for arrangement which concerns on 3rd Example.

  A first embodiment of a solder ball suction mask (hereinafter simply referred to as “suction mask”) will be described with reference to FIGS. 1 to 6. FIG. 2 shows a suction head 4 of a solder ball mounting device for carrying a solder ball 3 on an electrode 2 of a substrate 1 of an electronic component. The suction head 4 has a square dish-shaped case 5 whose lower surface is open, and a square plate-shaped suction mask 6 is mounted so as to cover the lower surface of the case 5. The case 5 is a metal molded product made of stainless steel or the like, and has a square top wall 7 and a peripheral side wall 8 extending downward from the outer periphery of the top wall 7. At the center of the top wall 7, a pipe 9 is provided so as to protrude upward. This pipe 9 is connected to a vacuum pump (not shown).

  The mask body 11 of the suction mask 6 is provided with a large number of suction through holes 12 for vertically sucking the solder balls 3 in a vertically penetrating manner. As shown in FIG. 3, a plurality of suction through holes 12 are formed in the vertical and horizontal directions in plan view, and the formation positions correspond to the number of the electrodes 2 on the substrate 1 side and the arrangement pitch.

  In the solder ball mounting apparatus as described above, the suction head 4 vacuum-adsorbs the solder balls 3 stored in the solder ball supply unit (not shown) into the suction holes 12 of the suction mask 6 and picks up the substrate 1. Then, after the solder ball 3 and the electrode 2 are aligned with each other and the suction head 4 is lowered, the solder ball 3 lands on the electrode 2. Next, the vacuum pump is stopped, the vacuum suction on the solder balls 3 is released, and then the suction head 4 is raised to leave the solder balls 3 on the electrodes 2 and move. The substrate 1 on which the solder balls 3 are placed is sent to a heating furnace of a reflow device and heated, and the solder balls 3 are melted and solidified to form bumps.

  As shown in FIG. 1, the suction mask 6 is mainly composed of a mask body 11 having a single layer structure formed by electroforming using a nickel alloy such as nickel or nickel cobalt, or another electrodeposited metal. The mask main body 11 includes a plurality of suction through holes 12 independently provided in a vertically penetrating manner, and reinforcing projections 13 formed between the suction through holes 12 and formed on the lower surface side of the mask main body 11. As shown in FIG. 3, the reinforcing protrusions 13 are formed in a square lattice shape formed by a ridge line 14 a running in the front and rear longitudinal direction and a ridge line 14 b running in the left and right horizontal direction in plan view, and On the lower surface of the main body 11, a large number of square (square) cell recesses 15 surrounded by the vertical and horizontal ridge lines 14 (14a and 14b) are formed. Each suction through-hole 12 is formed at the center of the board surface of the cell recess 15 defined by the ridge 14 of the reinforcing projection 13. Each of the suction through holes 12 is formed in a straight shape having uniform upper and lower opening dimensions.

  4 to 6 show a method of manufacturing the suction mask 6 according to the present embodiment. First, as shown in FIG. 4A, a photoresist layer 21 is formed on the surface of a matrix 20 made of a conductive metal such as stainless steel or copper. The photoresist layer 21 is formed by laminating one or several negative photosensitive dry photoresists in accordance with a predetermined height and thermocompression bonding. Next, a pattern film 23 (glass mask) having a light-transmitting hole 22 having a larger diameter than the suction through-hole 12 was brought into close contact with the photoresist layer 21 at a position corresponding to the position where the suction through-hole 12 was formed. After that, exposure is performed by irradiating ultraviolet light with an ultraviolet light lamp 24, development and drying are performed, and the unexposed portion is dissolved and removed, as shown in FIG. 4 (b). A primary pattern resist 26 having a large number of resist openings 25 having a larger diameter than the suction through-holes 12 is formed on the matrix 20 in correspondence with the formation positions of the resist 12 (see FIGS. 1 and 3).

  Subsequently, the matrix 20 is placed in an electroforming bath constructed under a predetermined condition, and electrodeposition of nickel or the like is performed on the exposed portion of the matrix 20 beyond the height of the primary pattern resist 26 through the resist opening 25. By electroforming the metal, a primary electroformed layer 28 having a V-shaped groove 27 is formed on the upper surface of the primary pattern resist 26 surrounded by the adjacent resist openings 25 as shown in FIG. Formed (primary electroforming step). In the primary electroforming step, when the primary electroformed layer 28 composed of the electrodeposited metal grown from the exposed portion of the matrix 20 through the resist opening 25 is over the height of the primary pattern resist 26, only the upward direction Instead, it grows in the vertical and horizontal directions (horizontal direction) so as to cover the primary pattern resist 26. In this embodiment, even after the electrodeposited metals grown from the respective resist openings 25 collide with each other on the upper surface of the primary pattern resist 26, the electrodeposition is continued until the grown electrodeposited metal reaches a predetermined thickness. As a result, as shown in FIG. 4C, at a position equidistant from the adjacent resist opening 25 on the upper surface of the primary pattern resist 26 of the primary electroformed layer 28, the primary electroformed layer 28 runs in a grid pattern in the vertical and horizontal directions. A groove 27 is formed.

  Next, as shown in FIG. 5A, after forming a photoresist layer 30 on the entire upper surface of the primary electroformed layer 28, the surface of the photoresist layer 30 corresponds to the suction through-hole 12. After the pattern film 32 having the light transmitting hole 31 is brought into close contact with the pattern film 32, exposure is performed by irradiating an ultraviolet light lamp 24, development and drying are performed, and the unexposed portion is dissolved and removed. As shown in b), a secondary pattern resist 34 having a resist projection 33 corresponding to the suction through hole 12 is formed on the upper surface of the primary electroformed layer 28.

  Subsequently, the master mold 20 and the like are placed in an electroforming tank built under predetermined conditions, and as shown in FIG. 6 (a), the resist projections 33 do not exceed the height of the resist projections 33. Electrodeposited metal such as nickel is electroformed on the surface of the primary electroformed layer 28 which is not covered with the above to form a secondary electroformed layer 35 (secondary electroforming step). In the secondary electroforming step, since the secondary electroforming layer 35 grows so as to fill the lattice-like grooves 27 formed on the upper surface of the primary electroforming layer 28, the lower surface of the secondary electroforming layer 35 The reinforcing protrusions 13 are formed in a lattice shape so as to surround the resist protrusions 33. In addition, recesses 16 are formed in a grid pattern on the upper surface of the secondary electroformed layer 35 corresponding to the reinforcing protrusions 13.

  Finally, the secondary electroformed layer 35 is peeled off from the primary electroformed layer 28 and the matrix 20, and the primary and secondary pattern resists 26 and 34 are removed. As shown, the suction mask 6 composed of only the secondary electroformed layer 35 can be obtained.

  As described above, according to the suction mask 6 of the present embodiment, since the reinforcing projections 13 are formed on the lower surface side of the mask main body 11 so as to protrude downward, the reinforcing projections 13 are integrated with the mask main body 11. In combination with the formation, the thickness of the suction mask 6 in the vertical direction is increased by the amount of the protrusion of the reinforcing projection 13, and the strength of the suction mask 6 can be increased. Therefore, the vacuum suction of the solder ball 3 effectively prevents the suction mask 6 from being bent and deformed even when a large load is applied to the center of the board surface of the suction mask 6, so that the predetermined shape of the substrate 1 is maintained. The solder balls 3 can be accurately placed on the positions, which contributes to the high precision of the bump electrodes.

  According to the suction mask 6 of the present embodiment, the strength of the suction mask 6 can be increased by providing the reinforcing protrusions 13. Therefore, the pitch interval between the suction through holes 12 in the mask body 11 is reduced. A necessary and sufficient structural strength can be given to the suction mask 6 by compensating for the accompanying decrease in the strength of the suction mask 6. As described above, it is possible to obtain the suction mask 6 suitable for narrowing the pitch of the electrodes 2 on the substrate 1.

  The reinforcing projections 13 are formed over the entire lower surface of the mask main body 11, and the reinforcing projections 13 are formed by a ridge line 14a running continuously in the front and rear longitudinal directions and a ridge line 14b running continuously in the left and right horizontal directions. Since it is formed in a square lattice shape, the structural strength of the suction mask 6 can be remarkably improved as compared with a configuration in which the reinforcing projections are partially formed or a configuration in which the reinforcing projections are formed discontinuously. . Therefore, also in this respect, it is possible to obtain the suction mask 6 suitable for narrowing the pitch of the electrodes 2.

  The suction mask 6 is a secondary electroformed layer 35 obtained by electroforming an electrodeposited metal on the primary electroformed layer 28. The mask is formed by a single electroforming step (secondary electroforming step). Since both the main body 11 and the reinforcing projections 13 are integrally formed, the mask body 11 and the reinforcing projections 13 are more excellent in integration than the form in which the mask main body 11 and the reinforcing projections 13 are formed by separate electroforming processes. Thus, a suction mask 6 can be obtained. Therefore, there is no inconvenience that the reinforcing projections 13 fall off from the mask main body 11, and the suction mask 6 with higher reliability can be obtained. In addition, since the mask body 11 having the suction holes 12 and the reinforcing projections 13 surrounding the suction holes 12 are integrally formed in the electroforming process, the suction mask 6 can be manufactured with high reproducibility.

  FIGS. 7 to 9 show a second embodiment of the solder ball suction mask. In the suction mask 6 of the present embodiment, as shown in FIGS. 7 and 8, a circular cell recess 15 is formed in the mask body 11 so as to surround each suction through hole 12. The point that the lower surface of the mask 6 is constituted by the inner bottom surface 41 of the cell concave portion 15 and the flat surface 40 located below the inner bottom surface 41 is different from the previous embodiment. Further, the suction mask 6 of the present embodiment is different from the previous embodiment in that the reinforcing protrusion 13 having the flat surface 40 is formed integrally with the mask body 11 so as to surround the cell recess 15.

  The suction mask 6 having the above configuration is prepared as follows. First, as shown in FIG. 4A of the previous embodiment, after a photoresist layer 21 is formed on the surface of a matrix 20, the photoresist layer 21 is formed on the photoresist layer 21 at a position corresponding to the formation position of the suction through hole 12. Then, after closely adhering a pattern film 23 having a light-transmitting hole 22 having a diameter larger than that of the suction through-hole 12, exposure is performed by irradiating ultraviolet light with an ultraviolet light lamp 24, and development and drying processes are performed. Then, by dissolving and removing the unexposed portions, as shown in FIG. 4B, a large number of resists having a diameter larger than that of the suction through-holes 12 corresponding to the formation positions of the suction through-holes 12. A primary pattern resist 26 having an opening 25 is formed on the matrix 20.

  Subsequently, as shown in FIG. 9A, the master 20 is placed in an electroforming tank in which baths are built under predetermined conditions, and an electrodeposition metal such as nickel is placed on an exposed portion of the master 20 via the resist opening 25. (Primary electroforming step). In the primary electroforming step, when the primary electroformed layer 28 formed of the electrodeposited metal grown from the exposed portion of the matrix 20 through the resist opening 25 exceeds the height of the primary pattern resist 26, In addition, it grows in the vertical and horizontal directions (horizontal direction) so as to cover the primary pattern resist 26. In this embodiment, unlike the previous embodiment, the electrodeposition is terminated before the electrodeposited metals grown from the respective resist openings 25 on the upper surface of the primary pattern resist 26 come into contact with each other. As shown in a), a part of the upper surface of the primary pattern resist 26 located at an equal distance from the adjacent resist opening 25 is not covered with the primary electroformed layer 28, and the primary pattern resist 26 appears. The exposed part 42 is formed. Further, a groove 43 is formed in the primary electroformed layer 28 corresponding to the exposed portion 42.

  Next, a secondary pattern resist 34 having a resist convex portion 33 corresponding to the suction through hole 12 is formed on the upper surface of the primary electroformed layer 28 by employing the same procedure as that of FIG. 20, the primary electroformed layer 28 and the like are placed in an electroforming bath constructed under predetermined conditions, and as shown in FIG. Electrodeposited metal such as nickel is electroformed on the surface of the primary electroformed layer 28 not covered with the portion 33 and on the concave groove 43 to form a secondary electroformed layer 35 (secondary electroforming step). In this secondary electroforming step, the secondary electroformed layer 35 grows so as to fill the concave groove 43, so that the reinforcing projections 13 are formed on the lower surface of the secondary electroformed layer 35 so as to surround the resist projection 33. Are formed in a protruding shape, and a flat surface 40 is formed at a protruding end of the reinforcing protrusion 13 corresponding to the exposed portion 42. In addition, a concave portion 16 is formed on the upper surface of the secondary electroformed layer 35 corresponding to the reinforcing protrusion 13.

  Finally, the secondary electroformed layer 35 is peeled off from the primary electroformed layer 28 and the matrix 20, and the primary and secondary pattern resists 26 and 34 are removed, as shown in FIGS. 9C and 7. As shown, the suction mask 6 composed of only the secondary electroformed layer 35 can be obtained.

  According to the suction mask 6 of the present embodiment having the above-described configuration, since the reinforcing protrusions 13 are formed over the entire lower surface of the mask body 11, the suction protrusions are smaller than the configuration in which the reinforcing protrusions are partially formed. The structural strength of the mask 6 for use can be significantly improved. Further, when the protruding end of the reinforcing projection 13 is a flat surface 40 as in the suction mask 6 of the present embodiment, the reinforcing projection 13 is formed in a lattice shape composed of ridge lines 14 running in the vertical and horizontal directions as in the previous embodiment. As compared with the embodiment, the thickness of the reinforcing projections 13 in the horizontal direction can be increased, so that the strength of the reinforcing projections 13 can be increased, and the structural strength of the suction mask 6 can be significantly improved.

  FIGS. 10 to 14 show a third embodiment of the solder ball suction mask. The suction mask 6 of this embodiment is different from the previous embodiment in that a plurality of conical reinforcing protrusions 13 are provided independently as shown in FIGS. 10 and 11. As shown in FIG. 11, in the suction mask 6 of the present embodiment, a pair of reinforcing protrusions 13 are arranged at a front and rear vertical position or a left and right horizontal position of one suction through hole 12. In other words, a pair of reinforcing protrusions 13 are arranged so as to sandwich one suction through hole 12 from the front and rear longitudinal direction or the left and right lateral direction.

  The suction mask 6 having the above configuration is prepared as follows. First, as shown in FIG. 12A, after a photoresist layer 46 is formed on the surface of a matrix 20 made of a conductive metal such as stainless steel or copper, the reinforcing protrusions 13 are formed on the photoresist layer 46. After a pattern film 48 (glass mask) having a light transmitting hole 47 having a diameter larger than the diameter at the base end side of the reinforcing protrusion 13 is brought into close contact with the formation position of Exposure is performed by irradiating the substrate with ultraviolet light, development and drying are performed, and the unexposed portion is dissolved and removed, as shown in FIG. 12B. A primary pattern resist 50 having a number of resist protrusions 49 having a larger diameter than the reinforcing protrusions 13 is formed on the matrix 20 in correspondence with the formation position of the reinforcing protrusions 13 (see FIG. 1).

  Subsequently, the master 20 is placed in an electroforming bath constructed under a predetermined condition, and the exposed portion of the master 20 exceeds the height of the resist projections 49 constituting the primary pattern resist 50, and the exposed portion of the master 20 is charged with nickel or the like. As shown in FIG. 12C, a primary electroformed layer 52 having a conical depression 51 is formed on the upper surface of the resist projection 49 by electroforming the deposited metal (primary electroforming step). In the primary electroforming step, when the primary electroformed layer 52 composed of the electrodeposited metal grown from the exposed portion of the matrix 20 exceeds the height of the resist convex portion 49, the primary electroformed layer 52 not only faces upward but also forms the resist convex portion. It also grows in the vertical and horizontal directions (horizontal direction) so as to cover the upper surface of 49. In the present embodiment, the electrodeposition is continued until the electrodeposited metal has a predetermined thickness. As a result, as shown in FIG. 12C, the upper surface of the resist projection 49 of the primary electroformed layer 52 is formed. , A conical recess 51 is formed at the center of the board surface.

  Next, as shown in FIG. 13A, after forming a photoresist layer 53 on the entire upper surface of the primary electroformed layer 52, the surface of the photoresist layer 53 corresponds to the suction through hole 12. After the pattern film 32 having the light transmitting holes 31 is brought into close contact with the pattern film 32, exposure is performed by irradiating an ultraviolet light lamp 24, development and drying are performed, and the unexposed portions are dissolved and removed, as shown in FIG. As shown in b), a secondary pattern resist 34 having a resist projection 33 corresponding to the suction through hole 12 is formed on the upper surface of the primary electroformed layer 28.

  Subsequently, the matrix 20 and the like are placed in an electroforming tank built under predetermined conditions, and as shown in FIG. 14 (a), the resist projections 33 do not exceed the height of the resist projections 33. Electrodeposited metal such as nickel is electroformed on the surface of the primary electroformed layer 52 that is not covered with the above, to form the secondary electroformed layer 55 (secondary electroforming step). In the secondary electroforming step, since the secondary electroforming layer 55 grows so as to fill the conical recess 51 formed on the upper surface of the primary electroforming layer 52, the lower surface of the secondary electroforming layer 55 Is formed with a conical reinforcing protrusion 13. In addition, a concave portion 16 is formed on the upper surface of the secondary electroformed layer 35 corresponding to the reinforcing protrusion 13.

  Finally, the secondary electroformed layer 55 is peeled off from the primary electroformed layer 52 and the matrix 20, and the primary and secondary pattern resists 50 and 34 are removed, as shown in FIGS. 14B and 10. As shown, a suction mask 6 composed of only the secondary electroformed layer 55 can be obtained.

  In the above-described primary electroforming step, the electrodeposition is completed before the electrodeposited metals grown as in the previous embodiment come into contact with each other on the resist projection 49, so that a part of the primary pattern resist 50 appears. By doing so, a truncated conical recess is formed at the center of the board surface on the upper surface of the resist projection 49. Thereafter, the steps of forming the secondary pattern resist 34, the secondary electroforming step, and the peeling step are sequentially performed, whereby the truncated conical reinforcing projections 13 are formed on the lower surface of the secondary electroformed layer 55. The suction mask 6 composed of only the next electroformed layer 55 can be obtained.

First Embodiment A solder ball arrangement mask (hereinafter simply referred to as an “array mask”) according to a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 15, the arrangement mask 60 is provided on the upper surface of the substrate 1 in the bump forming step, and is for mounting the solder balls 3 on the electrodes 2 formed on the substrate 1. is there.

  As shown in FIG. 15, the arrangement mask 60 is mainly composed of a mask main body 61 having a single layer structure formed by electroforming using a nickel alloy such as nickel or nickel cobalt, or another electrodeposited metal as a material. A plurality of ball through holes 62 independently provided in the mask body 61 in a vertically penetrating manner; a reinforcing projection 63 formed between the ball through holes 62 on the lower surface side of the mask body 61; And a guide recess 66 formed in a recess on the upper surface side of the mask main body 61. As shown in FIGS. 15 and 16, a region 65 having a uniform thickness and a flat upper and lower surface is formed between adjacent ball through holes 62. Each ball through-hole 62 is formed in a straight shape with uniform upper and lower opening dimensions.

  As shown in FIG. 16 (a), the reinforcing projections 63 are provided with a ridge line 64a running in the front and rear longitudinal direction so as to pass between the adjacent ball through holes 62 in the left-right direction in a plan view. A ridge line 64b running in the left and right sides is formed so as to protrude in a square lattice shape so as to pass through the center of the hole 62. That is, on the lower surface of the mask main body 61, a square grid-like reinforcing projection 63 composed of these vertical and horizontal ridge lines 64 (64a and 64b) is formed.

  On the upper surface of the mask main body 61, a guide concave portion 66 for guiding the solder ball 3 placed on the upper surface of the mask main body 61 to the ball through hole 62 is formed. As shown in FIG. 16 (b), the guide concave portion 66 has a guide groove 67a running in the front and rear longitudinal direction so as to pass between the adjacent ball through holes 62 in the left-right direction in plan view, and a guide groove 67a for each ball. A guide groove 67 b running in the left and right lateral directions is formed so as to protrude in a square lattice shape so as to pass through the center of the through hole 62. That is, on the upper surface of the mask main body 61, a guide recess 66 in the form of a square lattice formed by these vertical and horizontal guide grooves 67 (67a and 67b) is formed.

  17 to 19 show a method of manufacturing the alignment mask 60 according to the first embodiment. First, as shown in FIG. 17A, a photoresist layer 71 is formed on the surface of a matrix 70 made of a conductive metal such as stainless steel or copper. The photoresist layer 71 is formed by laminating one or several negative type photosensitive dry photoresists in accordance with a predetermined height and thermocompression bonding. Next, after a pattern film 73 (glass mask) having a light transmitting hole 72 corresponding to the position where the region 65 is formed is brought into close contact with the photoresist layer 71, ultraviolet light is irradiated with an ultraviolet lamp 74 to perform exposure. Then, by performing the respective processes of development and drying to dissolve and remove the unexposed portions, a region 65 (see FIGS. 15, 16A and 16B) is formed as shown in FIG. 17B. A primary pattern resist 76 having a number of resist openings 75 corresponding to the positions is formed on the matrix 70. That is, a primary pattern resist 76 having a resist opening 75 at an intermediate portion between the positions where the adjacent ball through holes 62 are formed is formed on the matrix 70.

  Subsequently, the master 70 is placed in an electroforming bath constructed under a predetermined condition, and electrodeposition of nickel or the like is performed on the exposed portion of the master 70 beyond the height of the primary pattern resist 76 through the resist opening 75. By electroforming the metal, as shown in FIG. 17C, a primary electroformed layer 78 having a V-shaped groove 77 is formed on the upper surface of the primary pattern resist 76 surrounded by the adjacent resist openings 75. Formed (primary electroforming step). In such a primary electroforming step, the primary electroformed layer 78 composed of the electrodeposited metal grown from the exposed portion of the matrix 70 through the resist opening 75, if the height exceeds the height of the primary pattern resist 76, only the upward direction Instead, it grows in the vertical and horizontal directions (horizontal direction) so as to cover the primary pattern resist 76. In this embodiment, even after the electrodeposited metals grown from the respective resist openings 75 collide with each other on the upper surface of the primary pattern resist 76, the electrodeposition is continued until the grown electrodeposited metal reaches a predetermined thickness. As a result, as shown in FIG. 17 (c), at an equidistant position from the adjacent resist opening 75 on the upper surface of the primary pattern resist 76 of the primary electroformed layer 78, the primary electroformed layer 78 runs in a grid in the vertical and horizontal directions. Groove 77 is formed.

  Next, as shown in FIG. 18A, a photoresist layer 80 is formed on the entire upper surface of the primary electroformed layer 78, and the surface of the photoresist layer 80 corresponds to the ball through-hole 62. After closely adhering a pattern film 82 having a light-transmitting hole 81 to be exposed, an exposure is performed by irradiating an ultraviolet lamp 74, development and drying are performed, and an unexposed portion is dissolved and removed. As shown in (b), a secondary pattern resist 84 having a resist convex portion 83 corresponding to the ball through hole 62 is formed on the upper surface of the primary electroformed layer 78.

  Subsequently, the matrix 70 and the like are placed in an electroforming tank constructed under a predetermined condition, and as shown in FIG. Electrodeposited metal such as nickel is electroformed on the surface of the primary electroformed layer 78 not covered with the above, to form the secondary electroformed layer 85 (secondary electroforming step). In such a secondary electroforming step, the secondary electroforming layer 85 grows so as to fill the lattice-like grooves 77 formed on the upper surface of the primary electroforming layer 78, so that the lower surface of the secondary electroforming layer 85 The reinforcement protrusions 63 are formed in a lattice shape so as to surround the resist protrusions 83. Guide recesses 66 are formed in a grid pattern on the upper surface of the secondary electroformed layer 85 corresponding to the reinforcing protrusions 63.

  Finally, the secondary electroformed layer 85 is peeled off from the primary electroformed layer 78 and the matrix 70, and the primary and secondary pattern resists 76 and 84 are removed. As shown, an arrangement mask 60 composed of only the secondary electroformed layer 85 can be obtained.

  The operation of arranging the solder balls 3 using the arrangement mask 60 is performed in the following procedure. First, after printing and applying a flux onto the electrode 2 on the substrate 1, the alignment mask 60 is positioned on the substrate 1 so that the ball through-hole 62 and the electrode 2 coincide with each other. Fix 60. In this fixed state, the lower end portion of the reinforcing projection 63 abuts on the surface of the substrate 1, so that the arrangement mask 60 is held in a separated posture in which the facing distance with the substrate 1 is secured as shown in FIG. Is done. That is, the reinforcing protrusion 63 also serves as a support protrusion for securing a space facing the substrate 1.

  Next, a large number of solder balls 3 are supplied onto the arrangement mask 60, and the solder balls 3 are dispersed on the arrangement mask 60 using a squeegee brush. Input 3 At this time, the solder ball 3 moves toward the ball through-hole 62 while being guided by the guide recess 66, so that the solder ball 3 can be more quickly put into the ball through-hole 62. Each of the solder balls 3 put into the ball through-hole 62 is temporarily held in an adhesive state by a flux. The substrate 1 on which the solder balls 3 are placed is sent to a heating furnace of a reflow device and heated, and the solder balls 3 are melted and solidified to form bumps.

  As described above, according to the arrangement mask 60 of the first embodiment, the reinforcing protrusions 63 are formed on the lower surface side of the mask main body 61 so as to protrude downward. The thickness of the arranging mask 60 in the vertical direction is increased by the amount of the protrusion of the reinforcing projection 63, and the strength of the arranging mask 60 can be increased. Therefore, even when a large number of solder balls 3 are placed on the upper surface of the arrangement mask 60 and a large load acts on the arrangement mask 60, the arrangement mask 60 is effectively prevented from being bent and deformed. In addition, the solder ball 3 can be accurately placed at a predetermined position on the substrate 1, which contributes to the high precision of the bump electrode.

  According to the arrangement mask 60 according to the first embodiment, by providing the reinforcing protrusions 63, the strength of the arrangement mask 60 can be increased, so that the pitch interval between the ball through-holes 62 in the mask main body 61 is reduced. A necessary and sufficient structural strength can be given to the alignment mask 60 by compensating for a decrease in the strength of the alignment mask 60 due to the narrowing. As described above, an arrangement mask 60 suitable for narrowing the pitch of the electrodes 2 on the substrate 1 can be obtained.

  The reinforcing projection 63 is formed over the entire lower surface of the mask body 61, and the reinforcing projection 63 is formed by a ridge line 64a running continuously in the front and rear longitudinal direction and a ridge line 64b running continuously in the left and right horizontal direction. Since it is formed in a square lattice shape, the structural strength of the arrangement mask 60 can be remarkably improved as compared with a configuration in which the reinforcing projections are partially formed or a configuration in which the reinforcing projections are formed discontinuously. . Therefore, the arrangement mask 60 suitable for narrowing the pitch of the electrodes 2 can be obtained also in this regard.

  When the guide recess 66 is formed over the entire upper surface of the mask body 61, the guide recess 66 guides the solder ball 3 placed on the upper surface of the mask body 61 to move toward the ball through hole 62. Therefore, the solder balls 3 can be quickly dropped into the ball through-holes 62, and the work efficiency of the work of inserting the solder balls 3 can be improved. Further, since the solder balls 3 can be moved and guided to the ball through-holes 62 by the guide recesses 66, the solder balls 3 can be reliably dropped into the respective ball through-holes 62. Balls of the solder balls 3 do not easily fall into the holes 62, and an arrangement mask 60 having excellent reliability can be obtained.

  The alignment mask 60 is a secondary electroformed layer 85 obtained by electroforming an electrodeposited metal on the primary electroformed layer 78. The mask is formed by a single electroforming process (secondary electroforming process). Since both the main body 61 and the reinforcing projection 63 are integrally formed, the mask main body 61 and the reinforcing projection 63 are more excellent in integration than the form in which the mask main body 61 and the reinforcing projection 63 are formed by separate electroforming processes. The alignment mask 60 can be obtained. Therefore, there is no inconvenience such that the reinforcing projections 63 drop off from the mask main body 61, and it is possible to obtain the alignment mask 60 with higher reliability. In addition, since the mask main body 61 having the ball through-hole 62 and the reinforcing protrusion 63 surrounding the ball through-hole 62 are integrally formed by the electroforming process, the arrangement mask 60 can be formed with high reproducibility. .

Second Embodiment FIGS. 20 and 21 show a second embodiment of the mask for arranging solder balls according to the present invention. In the arrangement mask 60 according to the second embodiment, the guide concave portion 66 formed on the upper surface of the mask main body 61 is eliminated, and the guide portion 88 is formed on the upper surface of the mask main body 61 in a protruding shape. This is different from the first embodiment.

  The arrangement mask 60 as described above can be obtained by forming the secondary electroformed layer 85 to a higher position in the secondary electroforming step of forming the secondary electroformed layer 85 than in the first embodiment. Can be. More specifically, similarly to the first embodiment, the step of forming the primary pattern resist 76 on the matrix 70 (see FIG. 17B) and the step of forming the primary electroformed layer 78 (see FIG. 17B). 17C) and a step of forming a secondary pattern resist 84 having a resist convex portion 83 (see FIG. 18). Next, the master mold 70 and the like are placed in an electroforming tank constructed under a predetermined condition, and as shown in FIG. Electrodeposited metal such as nickel is electroformed on the surface of the primary electroformed layer 78 not covered with the above, to form the secondary electroformed layer 85 (secondary electroforming step). In this embodiment, the height of the resist projection 83 formed in the step of forming the secondary pattern resist 84 is larger than that in the first embodiment, and is formed in the secondary electroforming step. The height dimension (thickness dimension) of the secondary electroformed layer 85 is also made larger than that in the first embodiment. As described above, when the height dimension (thickness dimension) of the secondary electroformed layer 85 formed in the secondary electroforming step is increased, the distance from the groove 77 formed on the upper surface of the primary electroformed layer 78 increases. Therefore, no depression is formed on the upper surface of the secondary electroformed layer 85 along the shape of the groove 77. Conversely, the upper surface of the secondary electroformed layer 85 is protruded upward to protrude. And the guide portion 88 can be formed. In this embodiment, the resist projection 83 is formed at a position surrounded by the groove 77 running in the vertical and horizontal directions.

  Finally, the secondary electroformed layer 85 is peeled off from the primary electroformed layer 78 and the matrix 70, and the primary and secondary pattern resists 76 and 84 are removed. As shown, an arrangement mask 60 composed of only the secondary electroformed layer 85 can be obtained.

  As described above, even when the guide portion 88 is formed in a protruding shape on the upper surface of the mask main body 61, the same operation and effect as when the guide concave portion 66 is provided (the first embodiment) can be obtained. That is, since the solder balls 3 can be moved and guided by the guide portions 88 toward the ball through-holes 62, the solder balls 3 can be quickly dropped into the respective ball through-holes 62, and the work of loading the solder balls 3 can be performed. Work efficiency can be improved.

Third Embodiment FIGS. 22 to 26 show a third embodiment of a mask for arranging solder balls according to the present invention. In the arrangement mask 60 according to the third embodiment, each of the ridge lines 64a provided on the lower surface of the mask main body 61 and running in the longitudinal direction before and after forming the reinforcing projections 63 and the ridge lines 64b running in the left and right lateral directions are each It is different from the first embodiment in that it is configured to pass through the center of the ball through hole 62. Similarly, in the arrangement mask 60 according to the third embodiment, the guide grooves 67a provided on the upper surface of the mask main body 61 and corresponding to the reinforcing projections 63 and running in the longitudinal direction before and after forming the guide concave portions 66 have the same shape. Is different from the first embodiment in that each of the guide grooves 67b running in the horizontal direction passes through the center of each ball through hole 62. Furthermore, in the arrangement mask 60 according to the third embodiment, a region 65 formed between the adjacent ball through holes 62 and having a uniform thickness and a flat upper and lower surface is a square in plan view. It is different from the first embodiment in that it is formed in a shape.

  24 to 26 show a method of manufacturing the alignment mask 60 according to the third embodiment. First, as shown in FIG. 24A, a photoresist layer 71 is formed on the surface of a matrix 70 made of a conductive metal such as stainless steel or copper. The photoresist layer 71 is formed by laminating one or several negative type photosensitive dry photoresists in accordance with a predetermined height and thermocompression bonding. Next, after a pattern film 73 (glass mask) having a light transmitting hole 72 corresponding to the position where the region 65 is formed is brought into close contact with the photoresist layer 71, ultraviolet light is irradiated with an ultraviolet lamp 74 to perform exposure. 24B, the unexposed portions are dissolved and removed by performing the respective processes of development and drying, and as shown in FIG. 24B, a large number of square squares corresponding to the formation positions of the region 65 (see FIG. 23) are formed. A primary pattern resist 76 having a resist opening 75 is formed on the matrix 70.

  Subsequently, the master 70 is placed in an electroforming bath constructed under a predetermined condition, and electrodeposition of nickel or the like is performed on the exposed portion of the master 70 beyond the height of the primary pattern resist 76 through the resist opening 75. By electroforming the metal, as shown in FIG. 24C, a primary electroformed layer 78 having a V-shaped groove 77 is formed on the upper surface of the primary pattern resist 76 surrounded by the adjacent resist openings 75. Formed (primary electroforming step). In such a primary electroforming step, the primary electroformed layer 78 composed of the electrodeposited metal grown from the exposed portion of the matrix 70 through the resist opening 75, if the height exceeds the height of the primary pattern resist 76, only the upward direction Instead, it grows in the vertical and horizontal directions (horizontal direction) so as to cover the primary pattern resist 76. In this embodiment, even after the electrodeposited metals grown from the respective resist openings 75 collide with each other on the upper surface of the primary pattern resist 76, the electrodeposition is continued until the grown electrodeposited metal reaches a predetermined thickness. As a result, as shown in FIG. 24 (c), the primary electroformed layer 78 runs in a grid pattern in the vertical and horizontal directions at an equidistant position from the adjacent resist opening 75 on the upper surface of the primary pattern resist 76. Groove 77 is formed.

  Next, as shown in FIG. 25A, after forming a photoresist layer 80 on the entire upper surface of the primary electroformed layer 78, the surface of the photoresist layer 80 corresponds to the through holes 62 for balls. After the pattern film 82 having the light transmitting holes 81 is brought into close contact with each other, exposure is performed by irradiating an ultraviolet lamp 74, development and drying are performed, and the unexposed portions are dissolved and removed. As shown in (b), a secondary pattern resist 84 having a resist convex portion 83 corresponding to the ball through hole 62 is formed on the upper surface of the primary electroformed layer 78. In the present embodiment, the resist projection 83 is formed at the intersection of the groove 77 running in the vertical and horizontal directions.

  Subsequently, the matrix 70 and the like are placed in an electroforming tank built under predetermined conditions, and as shown in FIG. 26 (a), the resist projections 83 do not exceed the height of the resist projections 83. Electrodeposited metal such as nickel is electroformed on the surface of the primary electroformed layer 78 not covered with the above, to form the secondary electroformed layer 85 (secondary electroforming step). In the secondary electroforming step, since the secondary electroforming layer 85 grows so as to fill the lattice-like grooves 77 formed on the upper surface of the primary electroforming layer 78, the lower surface of the secondary electroforming layer 85 The reinforcement protrusions 63 are formed in a lattice shape so as to surround the resist protrusions 83. Further, guide concave portions 66 are formed in a grid pattern on the upper surface of the secondary electroformed layer 85 corresponding to the reinforcing protrusions 63.

  Finally, the secondary electroformed layer 85 is peeled off from the primary electroformed layer 78 and the matrix 70, and the primary and secondary pattern resists 76 and 84 are removed. As shown, an arrangement mask 60 composed of only the secondary electroformed layer 85 can be obtained.

  According to the arrangement mask 60 according to the third embodiment, since the guide concave portion 66 composed of the guide grooves 67a and 67b is formed on the upper surface of the mask main body 61 so as to be inclined downward toward the ball through hole 62. The solder recesses 3 placed on the upper surface of the mask main body 61 can be dropped into the ball through holes 62 by the guide recesses 66, and the work efficiency of the loading operation of the solder balls 3 can be improved. In addition, since the solder balls 3 can be moved and guided toward the ball through holes 62 by the guide recesses 66, the solder balls 3 can be reliably dropped into the respective ball through holes 62. Balls of the solder balls 3 do not easily fall off of the solder balls 62, and an arrangement mask 60 having excellent reliability can be obtained.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Electrode 3 Solder ball 6 Suction mask 11 Mask main body 12 Suction through hole 13 Reinforcement protrusion 15 Cell recess 20 Matrix 21 Photoresist layer 22 Light transmission hole 23 Pattern film 24 Ultraviolet light lamp 25 Resist opening 26 Primary pattern resist 27 Groove 28 Primary electroformed layer 30 Photoresist layer 31 Light transmitting hole 32 Pattern film 33 Resist projection 34 Secondary pattern resist 35 Secondary electroformed layer 40 Flat surface 41 Inner bottom surface 42 Exposed portion 46 Photoresist layer 47 Light transmitting hole 48 Pattern film 49 resist convex portion 50 primary pattern resist 51 dent 52 primary electroformed layer 53 photoresist layer 55 secondary electroformed layer 60 alignment mask 61 mask body 62 ball through hole 63 reinforcing protrusion 66 guide recess 70 master mold 71 photo Resist layer 72 Light transmitting hole 73 Pattern film 74 External light lamp 75 resist opening 76 primary pattern resist 77 groove 78 primary electroformed layer 80 photoresist layer 81 light-transmitting hole 83 resist protrusions 84 secondary pattern resist 85 secondary electroformed layer 88 guide portion

Claims (5)

A large number of ball through-holes (62) are independently provided in the mask main body (61) in a vertically penetrating manner, and the solder ball (3) is transferred into the ball through-holes (62) to thereby form the substrate (1). ) Is an alignment mask for mounting solder balls (3) at predetermined positions on
On the lower surface side of the mask main body (61), a reinforcing projection (63) for enhancing the structural strength is formed integrally with the mask main body (61) so as to protrude downward .
A guide recess (66) for guiding the solder ball (3) to the ball through hole (62) is formed on the upper surface of the mask body (61).
The mask for arranging solder balls, wherein the guide concave portion (66) is formed corresponding to the reinforcing protrusion (63) in the thickness direction of the mask body (61) . The mask for arranging solder balls according to claim 1, wherein the guide recess (66) is formed by a guide groove (67) . The mask for arranging solder balls according to claim 1 or 2 , wherein the reinforcing projections (63) are formed in a square lattice shape surrounding each ball through hole (62) . A large number of ball through holes (62) are independently provided in the mask main body (61) in a vertically penetrating manner, and the solder ball (3) is transferred into the ball through hole (62) to thereby form the substrate (1). )), A solder ball (3) is mounted at a predetermined position, and a reinforcing projection (63) for enhancing the structural strength is provided on the lower surface side of the mask body (61) in a state of protruding downward. 61) a method of manufacturing an alignment mask formed integrally with
Forming a primary pattern resist (76) having a resist opening (75) between the positions where the ball through holes (62) are formed on the surface of the matrix (70);
Electrodeposited metal is electroformed on the matrix (70) beyond the height of the primary pattern resist (76), and grid-like grooves are formed on the primary pattern resist (76) surrounded by the resist openings (75). A primary electroforming step of forming a primary electroformed layer (78) having (77);
Forming a secondary pattern resist (84) having a resist projection (83) corresponding to the ball through-hole (62) on the primary electroformed layer (78);
A secondary electroforming step of electroforming an electrodeposited metal on the primary electroformed layer (78) within a range not exceeding the height of the resist projection (83) to form a secondary electroformed layer (85); ,
Removing the secondary electroformed layer (85) from the primary electroformed layer (78) and the matrix (70), and removing the primary and secondary pattern resists (76 and 84). A method for manufacturing a mask for arranging solder balls. 5. The secondary electroforming step according to claim 4, wherein the reinforcing projections (63) are formed corresponding to the lattice-shaped grooves (77) formed in the primary electroformed layer (78). A method for manufacturing a mask for arranging solder balls.

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