JP2011044615A - Mask for conductive ball arrangement, and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mask for conductive ball arrangement and a method for manufacturing the mask high in manufacturing efficiency, reduced in cost and smoothly transferring conductive balls into openings without damaging the conductive balls and mounting the conductive balls into predetermined positions of a substrate with more reliability. <P>SOLUTION: The method for manufacturing the mask for conductive ball arrangement in which a plurality of openings that can be inserted with the conductive balls are arranged in a predetermined arrangement pattern corresponding to the substrate to mount the conductive balls in the predetermined positions of the substrate, includes a patterning process for providing a pattern resist having resist bodies corresponding to the openings on the surface of a matrix; an electroforming process for electroforming electrodeposited metal on the matrix using the pattern resist to form an electrodeposited layer; a resist removing process for removing the resist bodies to expose the openings; and an electrolytic polishing process for forming slope-like ball guide parts at the bottom part peripheral edges of the openings. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a conductive ball arrangement mask for arranging, for example, conductive balls used for connection of a semiconductor and a circuit board on a substrate in a predetermined pattern, and a method for manufacturing the same.

  Conventionally, a transfer type is known as a method of mounting conductive balls on a pad of a substrate. As shown in FIG. 19, this is a method of mounting conductive balls 200 using a ball array mask 100 in which a required number of openings 110 are formed. In FIG. 19, reference numeral 300 indicates a wafer to be a substrate, reference numeral 310 indicates an electrode pad formed on the wafer 300, and reference numeral 320 indicates a flux applied on the electrode pad 310. Reference numeral 400 denotes a mask holding frame that holds the ball array mask 100.

  As shown in FIG. 19A, the opening 110 is generally formed to be slightly larger than the conductive balls 200. Normally, the conductive balls 200 that have rolled the ball arraying mask 100 are formed as follows. It falls (transfers) into the opening 110.

  However, there are cases where burrs (not shown), which are factors that hinder insertion of the conductive balls 200 into the openings 110, remain on the edge 111 of the openings 110, and the presence of such burrs causes the conductive balls 200 to open. There was a case where it did not go in.

  Therefore, as a ball array mask used for the transfer type, the entire circumference of at least one opening edge of the opening is laser processed so that the conductive ball can be more reliably inserted into the opening while removing the burrs and the like in advance. Thus, a ball array mask having a C-plane or an R-plane has been proposed (see, for example, Patent Document 1).

JP 2006-147697 A

  As described above, although attention is paid to the peripheral edge of the upper end portion that becomes the entrance to the opening 110 of the conductive ball 200, attention has never been paid to the peripheral edge of the lower end portion of the opening 110.

  That is, in the conventional ball array mask 100, the conductive balls 200 may be caught in the openings 110 in some cases, and may not be smoothly mounted on the wafer 300. In particular, once the flux 320 touches the inner wall surface of the opening 110, it proceeds upward as shown in FIG. 19B, and the conductive ball 200 touching the flux 320 is captured and placed in the opening 3. I sometimes stayed. This makes it impossible to expect that the electrode pad 310 is accurately mounted.

  An object of the present invention is to provide a conductive ball array mask that allows a conductive ball to smoothly pass through an opening, and a method for manufacturing the same.

  (1) The present invention provides a conductive ball in which a plurality of openings through which the conductive ball can be inserted are arranged in a predetermined arrangement pattern corresponding to the substrate in order to mount the conductive ball at a predetermined position of the substrate. In the arrangement mask, a saddle-like recess is formed at the lower edge of the opening.

  (2) The present invention is characterized in that, in the conductive ball arrangement mask of (1), the curvature radius of the recess is smaller than the curvature radius of the conductive ball.

  (3) The present invention is characterized in that, in the conductive ball array mask of the above (1) or (2), the edge of the recess is formed in an R shape.

  (4) In the present invention, in order to mount the conductive balls at predetermined positions on the substrate, a plurality of openings through which the conductive balls can be inserted are arranged in a predetermined arrangement pattern corresponding to the substrate, A method of manufacturing a conductive ball array mask in which a bowl-shaped recess is formed in the lower end periphery of an opening, and a patterning step of providing a pattern resist having a resist body corresponding to the opening on the surface of a mother die And an electroforming step of forming an electrodeposition layer by electroforming an electrodeposition metal using a predetermined plating solution on the matrix using the pattern resist, and the electrodeposition in a state where the resist body is left. An etching step of etching the metal and etching the vicinity of the resist body in a bowl shape.

  (5) The present invention is characterized in that, in the method for manufacturing an array mask according to (4), the plating solution contains Ni, Co, and a predetermined additive.

  (6) The present invention is the method for manufacturing an alignment mask according to the above (5), wherein the plating solution contains S and C having a compounding ratio of less than 1%, respectively, as the additive. And

  According to the present invention, since the removal of the conductive balls transferred to the openings of the conductive ball array mask is improved, the conductive balls can be more reliably mounted at a predetermined position on the substrate.

It is explanatory drawing of the board | substrate with which the mask for conductive ball arrangement | sequences concerning this embodiment is used. It is explanatory drawing of the mask for the same conductive ball arrangement | sequence. It is explanatory drawing which shows the use condition of the same conductive ball arrangement | sequence mask. It is explanatory drawing which shows the opening part of the same conductive ball arrangement | sequence mask. It is an enlarged view of the opening. It is explanatory drawing which shows one manufacturing process of the mask for conductive ball arrangement | sequences concerning this embodiment. It is explanatory drawing which shows one manufacturing process of the same mask for conductive ball arrangement | sequences. It is explanatory drawing which shows the modification of the mask for conductive ball arrangement | sequences. It is explanatory drawing which shows one manufacturing process of the mask for conductive ball arrangement | sequences concerning this embodiment. It is explanatory drawing which shows one manufacturing process of the same mask for conductive ball arrangement | sequences. It is explanatory drawing which shows one manufacturing process of the same mask for conductive ball arrangement | sequences. It is explanatory drawing which shows the state which arranged the conductive ball on the board | substrate using the conductive ball arrangement | sequence mask. It is explanatory drawing which shows the flow of the manufacturing process of the conductive ball arrangement | sequence mask which concerns on this embodiment. It is explanatory drawing which shows the manufacturing process of the mask for conductive ball arrangement | sequences concerning other embodiment. It is explanatory drawing which shows the modification of the manufacturing process. It is explanatory drawing which shows an example of the formation method of a support | pillar. It is explanatory drawing which shows an example of the formation method of a support | pillar. It is explanatory drawing of the recessed part which concerns on a modification. It is explanatory drawing which shows the behavior of the conventional conductive ball arrangement | positioning mask, and the conductive ball on the mask.

(Outline of conductive ball array mask)
In order to mount the conductive ball 2 (see FIG. 3) on the electrode pad 11 of the substrate 10 in FIG. 2, the substrate 10 made of a wafer in which a plurality of electrode pads 11 are arranged in a predetermined arrangement pattern in FIG. A conductive ball array mask 1 (hereinafter simply referred to as “array mask 1”) is shown.

  The array mask 1 corresponds to the array pattern of the electrode pads 11 of the substrate 10 and has a plurality of openings 3 through which conductive balls 2 made of solder balls, copper balls, or the like can be inserted. In the following description, it is assumed that a solder ball is used as the conductive ball 2.

  The array mask 1 is set and used in the mounting apparatus 4 schematically shown in FIG. As shown in the drawing, the mounting device 4 can place the substrate 10 with the surface on which the electrode pads 11 are arranged facing upward, and the surface of the substrate 10 on which the electrode pads 11 are arranged. A table 41 that can be set via the mask holding frame 5 with the opening 3 aligned with the electrode pad 11 is provided. Note that what is indicated by reference numeral 42 is a support base of the table 41.

  The mounting device 4 includes a conductive ball supply unit 45 with a supply port 44 provided above the left end (one end) of the arrangement mask 1 and the left end and the right in the drawing of the arrangement mask 1. A squeegee 46 capable of traversing is provided between the two ends while the upper surface and the tip of the arrangement mask 1 are in contact with each other.

  That is, the conductive balls 2 supplied to the upper surface of the arrangement mask 1 from the conductive ball supply unit 45 are captured by the tip of the squeegee 46 and are opened while being moved between both ends of the arrangement mask 1. 3 is inserted.

  Further, the mounting device 4 includes a removal portion 47 for the conductive ball 2. This is for removing the remaining conductive balls 2 not inserted into the openings 3 from the upper surface of the array mask 1, and has a supply port 48 disposed above the right end of the array mask 1. The remaining conductive ball 2 moved to the right end by the squeegee 46 can be removed.

(Characteristics of conductive ball array mask)
Hereinafter, the arrangement mask 1 according to the present embodiment will be described more specifically. FIG. 4 is a cross-sectional view of the opening 3 of the array mask 1, and FIG. 5 is an enlarged view of the opening 3. In FIG. 4, reference numeral 12 denotes a flux that is a temporary fixing material applied on the electrode pad 11 of the substrate 10. Reference numeral 6 denotes a support column formed on the back surface of the array mask 1. In this embodiment, the support column 6 is formed at appropriate intervals between the plurality of openings 3 and 3. . That is, when the support 6 is not provided or the number of support 6 is very small, when the conductive balls 2 are swung into the opening 3 while being pushed by the squeegee 46, the array mask 1 is bent downward and opened. There is a possibility that the portion 3 itself sinks and the conductive ball 2 is rubbed against the edge of the opening 3 or the conductive ball 2 swayed into the opening 3 jumps out. However, as in this embodiment, by forming an appropriate number of support columns 6 between the plurality of openings 3, 3, sinking of the openings 3 due to bending of the array mask 1 is prevented, so that The sex balls 2 are not rubbed. One strut 6 may be formed between each opening 3. Moreover, in this embodiment, the support | pillar part 6 is integrally molded with the same material as the arrangement | sequence mask 1, However, You may form by a retrofit etc. with a different material.

  For example, as shown in FIG. 16, after forming a pattern resist 95 on the surface of the electrodeposition layer 16 to be described later (FIG. 16A), the struts are formed in the resist pattern 95 in the same manner as the electrodeposition layer 16 or A plating layer 96 is formed by plating with a different material (nickel, copper, etc.), or a resin layer 96 is formed by embedding a resin (FIG. 16B), and the matrix 15 and the pattern resist 95 are removed (FIG. 16). (C)). In this way, the arrangement mask 1 having the column portions 6 made of metal or resin can be formed. In addition, as shown in FIG. 17, it is possible to form the support column portion 6 made of the resist 97 by performing resist patterning on the surface of the electrodeposition layer 16. In addition, this process can be performed anytime after the electroforming process described later.

  As shown in FIGS. 4 and 5, the opening 3 according to this embodiment formed in the array mask 1 has a diameter that is 10 to 20% longer than the diameter of the conductive ball 2, and It corresponds so that it may be located just above.

  In the opening 3 according to this embodiment, in order to easily guide the conductive ball 2 to the opening 3, a slope-shaped ball guiding portion 7 is formed at the upper peripheral edge 30 of the opening 3. As a more characteristic configuration, a bowl-shaped recess 8 is formed at the lower edge of the opening 3, and the curvature forming the bowl-shaped recess 8 is different from the curvature of the conductive ball 2. It is

  That is, the concave portion 8 having a curved surface with a predetermined curvature on the mask base side as shown in FIG. 3 is formed at the lower edge of the lower end. As will be described in detail later, in the present embodiment, the recess 8 is formed by etching.

  By forming such a bowl-shaped recess 8 on the lower edge of the opening 3, the conductive ball 2 swayed into the opening 3 is in contact with the inner wall surface while passing through the opening 3 while falling. Contact time is shortened. Thereby, it becomes difficult to receive the influence of the frictional resistance considered to be the cause that the conductive ball 2 is caught in the opening part 3, or static electricity. In addition, since the conductive ball 2 is in point contact at the edge portion of the recess 8, it easily falls to the substrate 10 side. Therefore, the ball separation of the conductive ball 2 becomes good, and the mountability to the electrode pad 11 is improved.

  In addition, because of the bowl-shaped recess 8, the flux 12 applied to the electrode pad 11 is difficult to touch the inner wall surface of the opening 3. Therefore, for example, the conductive ball 2 is captured by the flux 12 adhering to the inner wall surface and does not drop and stay in the opening 3, so that there is a risk of causing poor adhesion to the electrode pad 11. Can be prevented.

  In addition, it is preferable that the shape of the concave portion 8, for example, the concave shape of the concave portion, is such that the mounted conductive ball 2 does not enter the concave portion 8. Therefore, the diameter of the recess 8 needs to be smaller than the diameter of the conductive ball 2. In this embodiment, assuming that the radius of the conductive balls 2 is 50 μm, when the thickness of the mask arrangement mask 1 is about 50 to 70 μm, the virtual radius of the recess 8 is set in a range of about 15 to 25 μm. The curvature radius (curvature) of 8 is smaller (larger) than the curvature radius (curvature) of the conductive ball 2.

  That is, the diameter of the opening 3 is made to be about 10 to 20% longer than the diameter of the conductive ball 2 until the middle thereof, so that the conductive ball 2 falls as far as possible from the center of the opening 3. On the other hand, a recess 8 having an imaginary radius of approximately 15 to 25 μm is formed at the lower end of the opening 3 to improve the separation of the sphere (reducing the passage resistance of the conductive ball 2). Therefore, the conductive ball 2 is easily and reliably mounted on the electrode pad 11.

  On the other hand, the ball guiding portion 7 is set such that the horizontal distance L is longer than the height H (FIG. 5). Therefore, when the conductive balls 2 rolling on the arrangement mask 1 reach the gentle ball guiding portion 7, they are guided to the opening 3 and are smoothly dropped. In the present embodiment, when the ratio of the height direction to the horizontal direction is formed in a slope shape having an inclination of approximately 1: 2 to 1:20, and the diameter of the conductive ball 2 is assumed to be 100 μm, the height is assumed. The dimensions are set in a range of H = 1 to 5 μm and a horizontal distance L = 10 to 20 μm.

  As described above, since the slope-shaped ball guiding portion 7 is formed at the upper edge 30 of the opening 3, there is no possibility of damaging the conductive ball 2, and damage to the conductive ball 2 is reduced as much as possible. And can be smoothly dropped into the opening 3.

  As shown in FIGS. 4 and 5, the height of the end of the ball guiding portion 7 facing the opening 3 is larger than the diameter of the conductive ball 2. That is, when the conductive ball 2 drops from the opening 3 onto the substrate 10 and is mounted on the electrode pad 11, the conductive ball 2 is prevented from protruding upward from the upper edge 30 of the opening 3. In this way, no other conductive ball 2 enters the opening 3 in which the conductive ball 2 is accommodated, and the conductive ball 2 pushed in the horizontal direction by the squeegee 46 is already Since the upper part of the conductive ball 2 existing in the opening 3 is smoothly passed, there is no possibility that any of the conductive balls 2 is damaged.

  Hereinafter, a method for manufacturing the array mask 1 according to the present embodiment will be described with reference to FIGS.

(Patterning process)
First, a mother die 15 is prepared. Although not shown, a photoresist layer is formed on the surface of the mother die 15 and exposed, developed, and dried by well-known methods to dissolve unexposed portions. By removing the swelling, a pattern resist having a resist body 91 corresponding to the opening 3 is provided (see FIG. 6). The photoresist layer may be formed by laminating an appropriate number of negative photosensitive dry film resists.

(Electroforming process)
Next, the mother die 15 provided with the pattern resist is put into an electroforming tank (not shown) that has been bathed under a predetermined condition, and the resist body has a height equal to or higher than the height of the previous resist body 91. Electrodeposited metal is electroformed on the surface not covered with 91 to form the electrodeposition layer 16. After electroforming, it is preferable to mechanically polish the surfaces of the electrodeposition layer 16 and the resist body 91.

  The plating solution used in this electroforming process has Ni (nickel) and Co (cobalt) as main components, and S (sulfur) as a first additive and C (carbon) as a second additive. , Each containing less than about 1%. Therefore, the electrodeposition metal forming the electrodeposition layer 16 is a Ni—Co alloy. Further, as the material of the matrix 15, SUS that is easier to be selectively electropolished than the electrodeposition layer 16 is used. This is because, as will be described later, in order to form the ball guiding portion 7, it is important to use a material that is selectively electropolished as the material of the matrix 15 rather than the electrodeposition layer 16.

(Masking process for strut formation)
Then, a photoresist layer is formed on the surface of the matrix 15 on which the resist body 91 and the electrodeposition layer 16 are formed, and exposure, development, and drying are performed by known methods to remove unexposed portions. Thus, as shown in FIG. 6, a pattern resist having strut-forming resist bodies 92 formed at appropriate intervals is provided at a position excluding the resist body 91 (on the electrodeposition layer 16) to provide strut-forming masking. The photoresist layer in this case is also preferably formed by laminating several negative photosensitive dry film resists as appropriate.

(Etching process)
Next, as shown in FIG. 6, half-etching is performed to form the pillars while the pillar-forming resist bodies 92 are formed. Etching in this case may be a dip type in which etching is carried out in an etching tank containing a predetermined etching solution, and a general ferric chloride aqueous solution can also be used as the etching solution.

  According to this etching process, as shown in FIG. 7, the electrodeposition layer 16 made of a Ni—Co alloy is preferentially etched in the vicinity of the resist body 91. This is because the electrodeposition layer 16 in the vicinity of the resist body 91 is a high current density portion, and, as described above, the electrodeposition layer 16 is mainly composed of Ni and Co and contains less than 1% of S and C. As shown in the figure, the etching depth ratio is approximately 2: 1 in the vicinity of the resist body 91 and other portions as shown in the figure. A bowl-shaped concave portion 8 is formed in a deeply dug portion near the resist body.

  Here, if the matrix 15 is removed from the electrodeposition layer 16 by dissolution, peeling, or the like, as shown in FIG. Can do. In this case, the alignment mask 1 is not formed with the ball guiding portion 7 at the periphery of the upper end of the opening 3, but the conductive ball 2 can smoothly pass through the opening 3, so The purpose of improving the mountability can be sufficiently achieved. That is, when the arrangement mask 1 in which the concave portion 8 is formed at the lower end periphery of the opening 3 is used, the detachability of the conductive ball 2 from the opening 3 is greatly improved as described above.

  By the way, in this embodiment, although the support | pillar formation masking process was performed between the electroforming process and the etching process, since the support | pillar part 6 can be retrofitted with the raw material different from the electrodeposition layer 16, this support | pillar formation is also possible. The masking process is not essential and may be omitted.

  In order to obtain the array mask 1 that forms the ball guiding portion 7 at the upper edge of the opening 3, the following steps are performed thereafter.

(Resist removal process)
That is, after the etching step shown in FIG. 7, the resist body 91 and the support body forming resist body 92 are removed, and the opening 3 (matrix 15) is exposed (see FIG. 9).

(Electropolishing process)
Then, as shown in FIG. 9, the electrodeposition layer 16 formed on the SUS matrix 15 is electrolytically polished with the matrix 15 exposed from the opening 3.

  As is well known, the electropolishing is carried out by electrolyzing in a commonly used electrolytic solution such as phosphoric acid using the object to be polished (in this embodiment, composed of the matrix 15 and the electrodeposition layer 16) as an anode, and the anode surface, In this method, the surface of the object to be polished is smoothed.

  Here, in particular, the current strongly acts on the minimal protrusions such as burrs, the minimal gap formed at the interface between the matrix 15 and the electrodeposition layer 16 in the present embodiment, and as shown in FIG. In the opening 3, the interface portion between the mother die 15 and the electrodeposition layer 16 is dissolved, and the ball guiding portion 7 having a slope is formed on the mother die side periphery of the opening 3 (see FIG. 5).

  In addition, as in the present embodiment, the material of the matrix 15 is SUS, and the electrodeposited metal of the electrodeposition layer 16 is a Ni—Co alloy, so that the electrolytic corrosion due to the difference in the composition of the matrix 15 and the electrodeposition layer 16 is caused. Depending on the characteristics, the mother die 15 is selectively electropolished more than the electrodeposition layer 16, and the slope-shaped ball guiding portion 7 can be formed more easily. Furthermore, in the electropolishing step, it is possible to easily form an ideal slope shape by managing the electropolishing time and / or current (voltage).

  Finally, the matrix 15 is removed from the electrodeposition layer 16 by peeling or melting, and as shown in FIG. 11, a slope-shaped ball guiding portion 7 is formed at the upper edge of the opening 3 and the lower edge of the opening 3. The mask 1 for arrangement | sequence in which the bowl-shaped recessed part 8 was formed is obtained.

  In this arrangement mask 1, the ball guiding portion 7 formed by electropolishing is smoothed with improved surface roughness Ra (average roughness), and as described above, for fine deburring and the like. As described above, when the conductive ball 2 is swung into the opening 3 using the mounting device 4, the conductive ball 2 collides with the upper edge 30 of the opening 3 and is damaged. The ball 3 is smoothly penetrated into the opening 3, and a bowl-shaped recess 8 is formed on the periphery of the lower end of the opening 3. And smoothly mounted on the electrode pads 11 of the substrate 10 as shown in FIG.

  Thereafter, if the array mask 1 is removed from the mounting device 4 and the conductive balls 2 mounted on the electrode pads 11 are reflowed, the conductive balls 2 can be accurately welded to the electrode pads 11 of the substrate 10.

  As described above, the arrangement mask 1 in which the bowl-shaped recesses 8 are respectively formed on the peripheral edges of the lower ends of the openings 3 and the conductive balls 2 can be attached to the electrode pads 11 of the substrate 10 with high accuracy, as described above. Since a ferric chloride aqueous solution is obtained by a manufacturing method having an etching process using an etching solution, productivity is improved and the cost is extremely advantageous.

  As described above, according to the method for manufacturing an alignment mask according to the present embodiment, the opening 3 is formed in the electrodeposition layer 16 and etching is performed before the resist body 91 corresponding to the opening 3 is removed. As a result, the vicinity of the resist body 91 is preferentially etched (ratio of the etching depth in the vicinity of the resist body 91 and other portions = approximately 2: 1), and a hook-like shape is formed on the electrodeposition layer 16 (mask base) side. A recess 8 having a curved surface is formed on the lower edge of the opening 3.

  By the way, as shown in FIG. 18, the upper and lower edge portions 81, 81 of the bowl-shaped recess 8 formed on the peripheral edge of the lower end of the opening 3 of the array mask 1 are formed in an R shape.

  That is, as shown in FIGS. 9 and 10, when the electrolytic polishing process is performed, a ball guiding portion 7 having a slope is formed on the periphery of the opening 3 on the mother die side. The edge portions 81 and 81 are also affected by electropolishing and are considered to be formed microscopically in an R shape.

  Thus, when the arrangement mask 1 is manufactured as in the present embodiment, the end edge 81 of the recess 8 formed on the periphery of the lower end of the opening 3 is not an edge but a curved surface. There is no fear of damaging the conductive ball 2 even if it contacts with 2.

  In the present embodiment, the upper and lower edge portions 81 and 81 of the recess are each formed in an R shape. However, if at least one of them is an R shape, there is a possibility that the conductive ball 2 may be damaged. Decrease significantly. In that case, it is desirable that the upper edge 81 is R-shaped.

(Other embodiments)
Here, a manufacturing method according to another embodiment for obtaining an array mask in which a bowl-shaped recess 8 is formed at the lower edge of the opening 3 will be described with reference to FIG.

  In the previous manufacturing method, only the difference in etching speed between the vicinity of the resist body 91 and other areas is used to preferentially etch the vicinity of the resist body 91 to form the recesses 8. The deposition layer 16 has a two-layer structure, and the recess 8 is formed by introducing selective etching.

  That is, as shown in FIG. 14A, first, a mother mold 150 made of SUS or the like is prepared, a photoresist layer is formed on the surface of the mother mold 150, and exposure and development are performed by a well-known method. The pattern resist having the resist body 160 corresponding to the opening 3 is provided by performing each drying process and dissolving and removing the unexposed portion. In this case as well, the photoresist layer may be formed by laminating an appropriate number of negative photosensitive dry film resists.

  Next, as shown in FIG. 14B, the mother die 150 provided with the pattern resist is put in an electroforming tank (not shown) built on a predetermined condition, and half of the previous resist body 160 is placed. The first electrodeposition layer 170 is formed by electroforming Cu on the surface not covered with the resist body 160 so as to be deposited to a height, and then the resist body is formed by using Ni as an electrodeposition metal. The second electrodeposition layer 180 is formed on the first electrodeposition layer 170 by performing electroforming so as to be deposited until the height reaches 160.

  Here, the first electrodeposition layer 170 made of Cu and the second electrodeposition layer 180 made of Ni may be turned upside down. That is, electroforming with Ni as the electrodeposited metal may be performed first, and then electroforming with Cu as the electrodeposited metal may be performed.

  Next, as shown in FIG. 14C, a second pattern resist is provided. That is, a photoresist layer is formed on the second electrodeposited layer 180 or the first electrodeposited layer 170, and exposed, developed, and dried by known methods to dissolve and remove unexposed portions. Thus, a pattern resist having the resist body 190 is provided. The step of providing the second pattern resist is not essential and may be omitted although it is preferable to execute it.

  Next, as shown in FIG. 14D, an etching process is performed. Here, an etching solution suitable for etching only the second electrodeposition layer 180 serving as the uppermost layer is used. Therefore, when the etching in the vicinity of the resist body 190 proceeds and stops at the first electrodeposition layer 170, the etching rate is slower in the region separated from the resist body 190 than in the vicinity of the resist body 190. Thus, a bowl-shaped recess 8 is formed near the upper end of the resist body 190.

  Finally, as shown in FIG. 14E, the resist body 190 is dissolved and removed, and the two electrodeposition layers (first electrodeposition layer 170 and second electrodeposition layer 180) are peeled off from the matrix 150. In this case, the arrangement mask 1 in which the bowl-shaped concave portion 8 is formed on the lower edge of the opening 3 is obtained.

  For example, when a barrier layer such as an Au layer is interposed between the first electrodeposition layer 170 and the second electrodeposition layer 180, the material of the first electrodeposition layer 170 and the second electrodeposition layer 180 is An appropriate material can be selected without being limited to Cu and Ni.

  Further, a procedure shown in FIG. 15 will be described as a modification of the method for manufacturing the array mask. This is because a single electrodeposition layer 140 made of a single material is formed, a predetermined resist pattern is formed, and etching is performed to form a two-step saddle-shaped recess 8 ′ at the periphery of the lower end of the opening 3. It is what I did.

  That is, as shown in FIG. 15A, a mother mold 150 made of SUS or the like is prepared, a photoresist layer is formed on the surface of the mother mold 150, and exposure, development, and drying are performed by known methods. A pattern resist having the resist body 160 corresponding to the opening 3 is provided by dissolving and removing the unexposed portion by performing each of the above processes. In this case as well, the photoresist layer may be formed by laminating an appropriate number of negative photosensitive dry film resists.

  Next, the matrix 150 provided with the pattern resist is placed in an electroforming tank (not shown) bathed under a predetermined condition, and, for example, Ni is electrodeposited until the same height as the resist body 160 is reached. Deposited as metal, a single electrodeposition layer 140 is formed. The plating solution used at this time does not contain an additive.

  Then, a photoresist layer is formed on the single electrodeposition layer 140, and this is also subjected to exposure, development, and drying treatments by well-known methods to dissolve and remove unexposed portions, whereby a resist body 190 is obtained. A pattern resist having the following is provided.

  Next, as shown in FIG. 15B, when etching using a general ferric chloride aqueous solution is performed, as shown in the figure, there is a two-stage gap between the resist body 160 and the resist body 190. A recess 8 'is formed.

  Although the mechanism for forming such a two-stage saddle-shaped recess 8 'has not been elucidated, the distance between the resist body 160 and the resist body 190, the presence / absence of the additive of the plating solution, or the mixing ratio is affected. It is considered a thing.

  According to this embodiment, the following conductive ball array mask and its manufacturing method are realized.

  (1) A conductive ball array in which a plurality of openings 3 through which the conductive balls 2 can be inserted are arranged in a predetermined arrangement pattern corresponding to the substrate 10 in order to mount the conductive balls 2 at predetermined positions on the substrate 10. A conductive ball array mask 1, which is a mask 1 and has a bowl-shaped recess 8 formed in the lower edge of the opening 3. By using such an array mask 1, it is possible to reliably mount the conductive balls 2 that have been transferred into the openings 3 at predetermined positions on the substrate 10.

  (2) The conductive ball array mask 1 in which the radius of curvature of the recess 8 is smaller than the radius of curvature of the conductive ball 2. With such a conductive ball arraying mask 1, the mounted conductive balls 2 are smoothly mounted on the substrate 10 without the possibility that the mounted conductive balls 2 enter the recess 8.

  (3) The conductive ball arraying mask 1 in which the edge 81 of the recess 8 is formed in an R shape. With such a conductive ball arrangement mask 1, there is no possibility of damaging the conductive balls 2.

(4) In order to mount the conductive balls 2 at predetermined positions on the substrate 10, a plurality of openings 3 through which the conductive balls 2 can be inserted are arranged in a predetermined arrangement pattern corresponding to the substrate 10, and the openings 3 is a method for manufacturing a conductive ball arraying mask 1 having a bowl-shaped recess 8 formed in the lower peripheral edge of a pattern 3, and a pattern resist having a resist body 91 corresponding to the opening 3 is formed on the surface of a mother die 15. A patterning process to be provided, an electroforming process in which an electrodeposited metal is electroformed using a predetermined plating solution on the matrix 15 using the pattern resist, and an electrodeposition layer 16 is formed, and the resist body 91 remains. And etching the electrodeposited metal and etching the vicinity of the resist body 91 in a bowl shape. According to such a manufacturing method, it is possible to provide the array mask 1 that can securely mount the conductive balls 2 transferred to the opening 3 at a predetermined position of the substrate 10 at a very low cost. . Further, since the recesses 8 are formed by etching, the plurality of recesses 8 can be formed uniformly and can be realized at low cost. (5) The plating solution contains Ni, Co, and a predetermined additive. A method for manufacturing an array mask. According to this manufacturing method, it is possible to easily form the bowl-shaped recess 8 having a predetermined shape.

  (6) The said plating solution is a manufacturing method of the mask for arrangement | sequences which contains S and C which were less than 1% of the compounding ratio, respectively as said additive. According to this manufacturing method, it is possible to easily form the bowl-shaped recess 8 having a desired shape.

  (7) A method for manufacturing an array mask, comprising a column forming masking step in which an etching masking resist having a column forming resist body 92 is provided on the upper surface of the electrodeposited metal and resist body 91 before the etching step. According to such a manufacturing method, it is possible to easily form the column portions 6 appropriately between the plurality of openings 3 and 3, and the sinking of the openings 3 due to the bending of the array mask 1 is prevented. It is possible to prevent the conductive ball 2 from being damaged by rubbing.

  By the way, in the embodiment described above, each opening 3 can also be formed in a tapered shape constricted downward toward the substrate 10 when the alignment mask 1 is mounted on the mounting device 4. It becomes possible to mount the conductive ball 2 more accurately at a predetermined position.

  Further, in this embodiment, in order to define the slope shape of the ball guiding portion 7 formed at the upper peripheral edge of the opening 3, the length of time of the electropolishing process and the strength of the current are controlled, or both It is possible to control the time and / or current of the electropolishing process, such as simultaneously controlling the current and the like. That is, for example, the slope shape of the ball guiding portion 7 is set to a value between about 1: 2 to 1:20 in the ratio of the height direction to the horizontal direction, or toward the opening 3 side. Whether the slope is uniform or the stepped portion is formed on the slope (slope surface) can be managed by the current value and the polishing time.

  Although the present invention has been described through the above-described embodiments, the present invention is not limited to the above-described embodiments. The design can be changed as appropriate without departing from the scope of the claims.

DESCRIPTION OF SYMBOLS 1 Conductive ball array mask 2 Conductive ball 3 Opening 8 Recess 10 Substrate 11 Electrode pad 15,150 Master 16 Electrodeposition layer 91 Resist body

Claims (6)

In order to mount the conductive ball at a predetermined position of the substrate, a plurality of openings through which the conductive ball can be inserted is a conductive ball arrangement mask arranged in a predetermined arrangement pattern corresponding to the substrate,
A conductive ball arraying mask, wherein a bowl-shaped recess is formed at a lower edge of the opening.   2. The conductive ball arraying mask according to claim 1, wherein a radius of curvature of the recess is smaller than a radius of curvature of the conductive ball.   The conductive ball arraying mask according to claim 1 or 2, wherein an edge of the recess is formed in an R shape. In order to mount the conductive balls at predetermined positions on the substrate, a plurality of openings through which the conductive balls can be inserted are arranged in a predetermined arrangement pattern corresponding to the substrate, A method for manufacturing a conductive ball array mask in which a bowl-shaped recess is formed,
A patterning step of providing a pattern resist having a resist body corresponding to the opening on the surface of the matrix;
An electroforming step of forming an electrodeposition layer by electroforming an electrodeposition metal using a predetermined plating solution on the matrix using the pattern resist;
Etching the electrodeposited metal while leaving the resist body, and etching the vicinity of the resist body in a bowl shape;
The manufacturing method of the mask for arrangement | sequence characterized by having.   5. The method of manufacturing an array mask according to claim 4, wherein the plating solution contains Ni, Co, and a predetermined additive.   6. The method for manufacturing an array mask according to claim 5, wherein the plating solution contains S and C each having a compounding ratio of less than 1% as the additive.

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