JP2018006514A - Array mask for conductive pillar and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an array mask for a conductive pillar capable of completely dropping the conductive pillar into an array hole within a short time and further capable of accurately packaging the conductive pillar at a predetermined position on a workpiece while preventing inclination or positional displacement of the conductive pillar within the array hole, and a manufacturing method thereof.SOLUTION: The present invention relates to an array mask for packaging a columnar conductive pillar 2 at a predetermined position on a workpiece 3 by dropping the conductive pillar 2 into an array hole 12. The array hole 12 comprises: an introduction hole part 15 which is opened on a surface of a mask body 10, introduces and guides the conductive pillar 2 into the array hole 12; and a holding hole part 16 for positioning the conductive pillar 2. A lower end of the introduction hole part 15 and an upper end of te holding hole part 16 are smoothly continued. The introduction hole part 15 is formed in a bell mouth shape that is spread toward a surface side of the mask body 10, and the holding hole part 16 is formed in a straight hole shape in which an opening diameter D1 is set a little larger than a diameter of the conductive pillar 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an array mask in which conductive pillars are dropped into array through holes corresponding to a predetermined array pattern, and the conductive pillars are mounted at predetermined positions on a workpiece, and a method for manufacturing the same.

  An array mask for mounting a conductive ball made of solder at a predetermined position on a workpiece is known, for example, in Patent Document 1. The array mask disclosed in Patent Document 1 has a plurality of openings for dropping conductive balls. The opening is provided so as to correspond to the electrode pad formation pattern of the substrate (work). A slope-shaped ball guiding portion is formed on the periphery of the upper end of the opening, and the ball guiding portion is composed of an inclined surface that gently slopes downward toward the opening. At the time of dropping, a large number of conductive balls are supplied onto the arrangement mask and dispersed with a squeegee brush, etc., so that the conductive balls are guided toward the opening by the ball guiding portion, thereby smoothly moving the conductive balls. Can be dropped into the opening.

JP 2011-44616 A

  In recent years, in surface-mount packaged electronic devices and the like, the density of electrode formation patterns for connection to circuit boards has been increasing, and instead of conventional conductive balls, higher aspect ratios (higher Cylindrical conductive pillars capable of narrowing the mounting interval with the ratio of thickness / diameter) are being adopted. In the arrangement mask of Patent Document 1, the structure of the opening and the ball guiding portion is optimized so that the conductive balls can be dropped smoothly. However, even when the structure of the arrangement mask of Patent Document 1 is applied to a cylindrical conductive pillar arrangement mask, the same effect cannot be obtained. That is, in order for a cylindrical conductive pillar to fall into the opening (array through hole), one end of the conductive pillar must be directed to the opening. Furthermore, the conductive pillar needs to slide down the ball guiding portion with one end directed to the opening. However, it is difficult for the conductive pillar to slide down in the ball guide portion formed by the inclined surface that gently slopes downward. In addition, if the ball guiding portion rolls down with the peripheral surface of the conductive pillar in the lying position facing the opening, the conductive pillar blocks the opening without being able to fall into the opening, and the opening is blocked. The conductive pillar cannot be dropped.

  The object of the present invention is to enable the cylindrical conductive pillars to be smoothly dropped into the array through-holes, so that the mounting work of the conductive pillars can be completed in a short time, and the cylindrical pillars are further dropped into the array through-holes. Another object of the present invention is to provide a conductive pillar array mask capable of preventing the conductive pillars from being inclined and misaligned and mounting the conductive pillars accurately at predetermined positions on the workpiece, and a method for manufacturing the same.

  The present invention is directed to an array mask in which the cylindrical conductive pillars 2 are dropped into the array through holes 12 corresponding to a predetermined array pattern, and the conductive pillars 2 are mounted at predetermined positions on the workpiece 3. The array through-holes 12 are opened on the surface of the mask body 10 to introduce and guide the conductive pillars 2 into the array through-holes 12. The array through-holes 12 are provided below the introduction hole 15 and are provided with conductive pillars. 2 and the lower end of the introduction hole 15 and the upper end of the holding hole 16 are smoothly continuous. The introduction hole portion 15 is formed in a bell mouth shape that expands toward the surface side of the mask body 10, and the holding hole portion 16 has an opening diameter D 1 of the hole portion 16 larger than the diameter of the conductive pillar 2. It is characterized by being formed with straight holes set slightly larger.

  The arrangement through-hole 12 can take a configuration in which a clearance hole portion 17 having an opening diameter D3 larger than the opening diameter D1 of the hole portion 16 is provided below the holding hole portion 16.

  When the total height of the introduction hole 15 and the holding hole 16 is H1, and the height of the escape hole 17 is H2, the former height H1 is the same as the latter height H2, or Set larger than.

  When the height dimension of the introduction hole 15 is H3 and the height dimension of the holding hole 16 is H4, the latter height dimension H4 is set to be equal to or larger than the former height dimension H3.

  The curvature of the cross-sectional shape of the introduction hole 15 is formed so as to change in the circumferential direction of the introduction hole 15.

  The curvature of the cross-sectional shape of the introduction hole portion 15 is formed so as to gradually change from large to small from one side edge to the opposite other edge.

  The present invention is directed to a method of manufacturing an array mask in which the conductive pillars 2 are mounted at predetermined positions on the workpiece 3 by transferring the cylindrical conductive pillars 2 into the array through holes 12 corresponding to the predetermined array pattern. And In the method of manufacturing the array mask, a primary patterning process is provided in which a primary pattern resist 25 having a primary resist body 24 corresponding to the relief hole portion 17 is provided on the surface of the matrix 21, and the surface is introduced to the surface of the primary pattern resist 25. A secondary patterning process in which a secondary pattern resist 29 having a secondary resist body 28 corresponding to the hole 15 and the holding hole 16 is provided, and an electrodeposited metal is electrodeposited on the mother die 21 to form an electroformed layer 30. Forming an electroforming process. In the electroforming process, an electrodeposition metal is electrodeposited within a range not exceeding the upper edge of the primary resist body 24 and not exceeding the upper edge of the secondary resist body 28 to form the bell mouth-shaped introduction hole 15. Features.

  In the secondary patterning step, the secondary pattern resist 29 is provided in a state where the central axis Q2 of the secondary resist body 28 is located on the same axis as the central axis Q1 of the primary resist body 24.

  In the secondary patterning step, the secondary pattern resist 29 is provided in a state where the central axis Q2 of the secondary resist body 28 is offset from the central axis Q1 of the primary resist body 24.

  In the conductive pillar array mask of the present invention, the introduction hole portion 15 that constitutes the array through-hole 12 and the holding hole portion 16 are smoothly connected, and the introduction hole portion 15 that introduces and guides the conductive pillar 2 is provided as a mask. It was formed in a bell mouth shape that expands toward the surface side of the main body 10. Thus, according to the introduction hole 15 formed in the bell mouth shape, when dropping the conductive pillar 2 into the array through-hole 12, while changing the posture of the conductive pillar 2 in the lying position to the upright posture, The conductive pillars 2 can be introduced and guided to the array through holes 12 by dropping along the curved surface of the introduction hole 15. Specifically, when the position of the center of gravity of the conductive pillar 2 in the recumbent posture is positioned on the array through hole 12 beyond the upper end edge of the introduction hole 15, one end of the conductive pillar 2 positioned on the array through hole 12 is The introduction hole 15 can be tilted downward with the upper end edge of the introduction hole 15 as a fulcrum. Thereby, the posture of the conductive pillar 2 in the recumbent posture can be gradually changed from the recumbent posture to the upright posture. Furthermore, simultaneously with the posture change to the upright posture, the conductive pillar 2 can be slid along the introduction hole portion 15 into the array through-hole 12. Therefore, according to the array mask of the present invention, the conductive pillars 2 can be smoothly dropped into the array through holes 12, so that the mounting work of the conductive pillars 2 on the workpiece 3 can be completed in a short time.

  Further, according to the straight holding hole 16 in which the opening diameter D1 is set to be slightly larger than the diameter of the conductive pillar 2, the conductive material introduced and guided by the introduction hole 15 and dropped into the array through hole 12. The active pillar 2 can be received and positioned on the inner surface of the holding hole 16. Therefore, according to the arrangement mask of the present invention, the conductive pillars 2 can be accurately positioned by the holding holes 16, and further, the inclination and displacement of the conductive pillars 2 in the arrangement through holes 12 can be prevented. The conductive pillar 2 can be mounted at a predetermined position on the 3 with high accuracy.

  According to the array through-hole 12 having the escape hole 17 having an opening diameter D3 larger than the opening diameter D1 of the hole 16 below the holding hole 16, the conductive pillar 2 and the axis of the holding hole 16 are provided. The length of the engaging portion in the center direction can be made smaller than that of the array through-hole 12 in which the escape hole portion 17 is not provided. Therefore, after the conductive pillar 2 is mounted on the work 3, the arrangement mask can be separated from the work 3 with a smaller amount of movement, so that the conductive pillar 2 can be tilted or displaced when the arrangement mask is separated. In this way, the conductive pillar 2 can be more accurately mounted at a predetermined position on the work 3. Further, when the arrangement mask is placed on the work 3, the contact area between the work 3 and the arrangement mask can be made as small as possible. As a result, it is possible to suppress damage to the array mask and the work 3 caused by placing the array mask on the work 3, and the durability of the array mask can be improved. Furthermore, the flux may be applied to the mounting position of the conductive pillar 2 on the workpiece 3, but even in such a case, the flux is prevented from adhering to the arrangement mask by the escape holes 17, The trouble of cleaning the array mask can be saved.

  When the total height H1 of the introduction hole 15 and the holding hole 16 is set to be equal to or larger than the height H2 of the escape hole 17, the escape hole 17 is formed below the holding hole 16. Even when provided, the introduction hole 15 and the holding hole 16 having a sufficiently high height can be formed. Therefore, the introduction guide action of the conductive pillar 2 in the introduction hole 15 and the positioning action of the conductive pillar 2 in the holding hole 16 can be exhibited accurately.

  When the height dimension H4 of the holding hole 16 is set to be equal to or larger than the height dimension H3 of the introduction hole 15, the position retaining action of the conductive pillar 2 in the holding hole 16 is made as much as possible. The conductive pillar 2 can be accurately mounted at a predetermined position on the work 3.

  If the curvature of the cross-sectional shape of the introduction hole portion 15 is formed so as to change in the circumferential direction of the introduction hole portion 15, the introduction guide action of the conductive pillar 2 is greatly exerted in a portion with a small curvature, and in the portion with a large curvature. The height dimension H4 of the holding hole 16 can be increased to greatly exert the positioning action of the conductive pillar 2 in the holding hole 16. Therefore, the conductive pillars 2 can be partially dropped easily in the circumferential direction of the introduction hole 15, and the arrayed through holes 12 that can accurately position the dropped conductive pillars 2 can be obtained.

  When the curvature of the cross-sectional shape of the introduction hole portion 15 is formed so as to gradually change from large to small from one side edge to the opposite other edge, for example, the arrangement is made so that the small curvature side is directed in the same direction. By forming the holes 12, when the conductive pillars 2 are dropped, the squeegee is moved from the small curvature side toward the large side, so that the conductive pillars 2 can be dropped into the array through holes 12 more quickly. Can be completed in a shorter time.

  According to the method for manufacturing the conductive pillar array mask according to the present invention, there is no need to separately perform a process for forming the introduction hole 15 in the bell mouth shape, and the array through which the introduction hole 15 in the bell mouth shape is provided. An array mask having the holes 12 can be manufactured. Specifically, the edge of the growth tip of the electroformed metal that grows over the upper edge of the primary resist body 24 grows in a quadrant shape. Accordingly, in the electroforming step, the bell mouth-shaped introduction hole 15 can be formed only by electrodepositing the electrodeposited metal within a range not exceeding the upper end edge of the primary resist body 24 and not exceeding the upper end edge of the secondary resist body 28. Can be formed. Therefore, it is possible to shorten the work process in the manufacturing process of the array mask and reduce the manufacturing cost of the array mask.

  In the secondary patterning process, when the central axis Q2 of the secondary resist body 28 is positioned on the same axis as the central axis Q1 of the primary resist body 24, the distance over which the upper end edge of the primary resist body 24 is grown. Can be made uniform in the circumferential direction, so that the cross-sectional shape of the introduction hole portion 15 can be formed identically in the circumferential direction. Therefore, the introduction guide action of the conductive pillars 2 in the introduction hole portion 15 can be exhibited uniformly in the circumferential direction, and the array through-holes 12 that can smoothly drop the conductive pillars 2 from any direction can be formed.

  In the secondary patterning step, when the central axis Q2 of the secondary resist body 28 is offset from the central axis Q1 of the primary resist body 24, the distance over which the upper edge of the primary resist body 24 grows is increased in the circumferential direction. Therefore, the cross-sectional shape of the introduction hole 15 can be formed so that the curvature gradually changes from large to small in the circumferential direction. At this time, the curvature of the cross-sectional shape becomes smaller as the distance over which it grows is longer. As a result, the introduction and guiding action of the conductive pillar 2 is greatly exerted on the side having a small curvature, and the height dimension H4 of the holding hole portion 16 is increased on the side having a large curvature so that the conductive pillar in the holding hole portion 16 is increased. The positioning action 2 can be exerted greatly. Therefore, it is possible to easily form the array through-holes 12 capable of accurately positioning the dropped conductive pillars 2 by simply performing the electroforming process while easily dropping the conductive pillars 2.

It is a vertical front view which shows the principal part of the mask for arrangement | sequence of the conductive pillar which concerns on 1st Embodiment of this invention. It is a perspective view for demonstrating the whole structure of the mask for arrangement | sequence of the conductive pillar which concerns on 1st Embodiment of this invention. It is a vertical front view of the conductive pillar arrangement mask according to the first embodiment of the present invention. It is a figure which shows the manufacturing method of the mask for arrangement | sequence of the conductive pillar which concerns on 1st Embodiment of this invention. It is a figure which shows the manufacturing method of the mask for arrangement | sequence of the conductive pillar which concerns on 1st Embodiment of this invention. It is a vertical front view which shows the principal part of the mask for arrangement | sequence of the conductive pillar which concerns on 2nd Embodiment of this invention. It is a top view which shows the principal part of the mask for arrangement | sequence of the conductive pillar which concerns on 2nd Embodiment of this invention. It is a figure which shows the manufacturing method of the mask for arrangement | sequence of the conductive pillar which concerns on 2nd Embodiment of this invention. It is a vertical front view of the conductive pillar arrangement mask according to the third embodiment of the present invention.

First Embodiment FIGS. 1 to 3 show a first embodiment of a conductive pillar array mask according to the present invention. Note that the dimensions such as the thickness and the width in FIGS. 1 to 3 of the present embodiment do not show the actual state, but schematically show each. The same applies to the other drawings. An array mask (hereinafter simply referred to as a mask) 1 is used in a mounting operation of conductive pillars 2 in forming an electrode post of an LSI chip. As shown in FIG. 3, the conductive pillar 2 is a cylindrical block made of copper, and has a diameter of 80 μm and a height of 85 μm. In FIG. 2, reference numeral 3 denotes a workpiece on which the conductive pillar 2 is mounted by the mask 1, and this workpiece 3 is molded and sealed after mounting a plurality of semiconductor chips 5 on a base 4 of a glass epoxy substrate. Is formed. On the upper surface of the work 3, electrodes 6 as input / output terminals are formed in a predetermined pattern so as to surround the semiconductor chip 5. The work 3 is diced along a dicing line shown by a one-dot chain line in FIG. 2 after the electrode post is formed, and is divided into individual LSI chips.

  The mask 1 includes a mask body 10 formed by electroforming using an electrodeposited metal made of nickel, and a frame-like frame body 11 attached so as to surround the mask body 10. A large number of independent array through holes 12 corresponding to the array pattern matching the formation pattern of the electrodes 6 are formed on the surface of the mask body 10. The conductive pillar 2 can be mounted at a predetermined position on the workpiece 3 by dropping the conductive pillar 2 into the array through-hole 12. The frame 11 reinforces the mask main body 10 and is made of a material having a low coefficient of thermal expansion such as 42 alloy, Invar material, Super Invar material, SUS430, etc., which is thicker than the mask main body 10. The frame body 11 is bonded to the outer peripheral edge of the mask main body 10 with an adhesive or the like, so that the both 10 and 11 are joined together in an integrated manner. The mask body 10 can be made of a nickel alloy such as nickel cobalt, copper, or other electrodeposited metal.

  As shown in FIG. 1, the array through-hole 12 includes an introduction hole 15 that opens on the surface of the mask body 10, and a holding hole 16 that is provided below the introduction hole 15. The lower end of 15 and the upper end of the holding hole portion 16 are smoothly continuous. In addition, the array through-hole 12 includes a relief hole 17 below the holding hole 16.

  The introduction hole portion 15 is formed in a bell mouth shape that expands toward the surface side of the mask main body 10, and when the conductive pillar 2 is dropped into the array through-hole 12, the conductive pillar 2 is inserted into the array through-hole 12. It has the effect of guiding it into the inside. The cross-sectional shape of the introduction hole 15 is the same in the circumferential direction, and the introduction guide action of the conductive pillar 2 in the introduction hole 15 can be uniformly exhibited in the circumferential direction. The cross-sectional shape of the introduction hole portion 15 in the present embodiment is formed as a perfect circular quarter arc.

  The holding hole portion 16 is formed in a straight hole shape in which the opening diameter D1 is set to be slightly larger than the diameter of the conductive pillars 2, and positions the conductive pillars 2 dropped into the array through-holes 12. Have When the outer peripheral surface of the conductive pillar 2 comes into contact with the inner peripheral surface of the holding hole portion 16, tilting and displacement are prevented, and the conductive pillar 2 is positioned.

  The escape hole portion 17 is formed in a straight hole shape having an opening diameter D3 larger than the opening diameter D1 of the holding hole portion 16, and the central axis P2 of the escape hole portion 17 is the same as the central axis P1 of the holding hole portion 16. Located on the same axis. In the present embodiment, the opening diameter D1 of the holding hole portion 16 is set to 85 μm, the opening diameter D2 at the upper end of the introduction hole portion 15 is set to 125 μm, and the opening diameter D3 of the escape hole portion 17 is set to 145 μm.

  The total height H1 of the introduction hole 15 and the holding hole 16 is set to be larger than the height H2 of the escape hole 17, the former height H1 being 50 μm, and the latter height dimension. H2 is 40 μm. Thus, if the height dimension H1 of the array through-holes 12 is set to be larger than the height dimension H2 of the escape hole part 17, even if the escape hole part 17 is provided below the holding hole part 16, the height dimension H1 is sufficiently high. The introduction hole 15 and the holding hole 16 can be formed. Therefore, the introduction guide action of the conductive pillar 2 in the introduction hole 15 and the positioning action of the conductive pillar 2 in the holding hole 16 can be exhibited accurately.

  A height dimension H4 of the holding hole portion 16 is set to be larger than a height dimension H3 of the introduction hole portion 15. The latter height dimension H3 is 20 μm, and the former height dimension H4 is 30 μm. As described above, when the height dimension H4 of the holding hole 16 is set larger than the height dimension H3 of the introduction hole 15, the positioning action of the conductive pillar 2 in the holding hole 16 can be more reliably exhibited. it can.

  The mounting operation of the conductive pillar 2 on the workpiece 3 using the mask 1 is performed in the following procedure. This mounting operation is performed by a dedicated arrangement device including a pillar supply device, a surplus pillar recovery device, a squeegee brush, and the like. First, a flux is printed on the surface of the electrode 6 of the work 3 by screen printing. The flux activates the surface of the electrode 6 to improve the bonding strength between the electrode 6 after reflow and the conductive pillar 2, and the conductive pillar 2 due to the adhesiveness of the flux when the conductive pillar 2 is mounted. Is applied for the purpose of temporarily fixing.

  Next, after aligning the mask 1 on the work 3 so that the array through-holes 12 coincide with the electrodes 6, the mask 1 is placed and fixed. At this time, the contact area between the work 3 and the mask 1 can be made as small as possible by the escape hole portion 17, so that the damage of the mask 1 and the work 3 caused by placing the mask 1 on the work 3 is suppressed. The durability of the mask 1 can be improved. Further, the escape hole 17 prevents the flux from adhering to the mask 1, and the labor for cleaning the mask 1 can be saved.

  Next, a large number of conductive pillars 2 are supplied onto the mask 1, and the conductive pillars 2 are dispersed on the mask 1 using a squeegee brush. Drop. The conductive pillars 2 are dropped into the array through holes 12 as follows. When the position of the center of gravity of the conductive pillars 2 in a recumbent posture dispersed by the squeegee brush is positioned on the array through holes 12 beyond the upper end edge of the introduction hole portion 15, the conductive pillars 2 positioned on the array through holes 12. Is tilted downward with the upper edge of the introduction hole 15 as a fulcrum. Thereby, the posture of the conductive pillar 2 in the recumbent posture is gradually changed from the recumbent posture to the upright posture. Furthermore, simultaneously with the posture change to the upright posture, the conductive pillar 2 slides into the array through hole 12 along the introduction hole portion 15. As a result, the conductive pillar 2 is introduced and guided by the introduction hole portion 15 and smoothly dropped into the array through-hole 12. The conductive pillars 2 dropped into the array through-holes 12 are accurately positioned on the inner surface of the holding hole 16 in addition to temporary fixing with flux.

  When the dropping of the conductive pillar 2 is completed, the excess conductive pillar 2 remaining on the mask 1 is recovered. Finally, the work 3 and the mask 1 are unlocked, and the mask 1 is lifted and separated to complete the work of mounting the conductive pillar 2 on the work 3. At this time, since the length of the engagement portion in the axial direction of the engagement portion between the conductive pillar 2 and the holding hole portion 16 is reduced by the escape hole portion 17, the mask 1 can be moved from the workpiece 3 with a small amount of movement. It is possible to prevent the conductive pillar 2 from being inclined or displaced when the mask 1 is separated.

4 and 5 show a method of manufacturing the array mask according to the first embodiment.
(Primary patterning process)
As shown in FIG. 4A, a circular light transmitting hole corresponding to the escape hole 17 is formed after forming a photoresist layer 22 on the entire surface of a mother mold 21 made of, for example, stainless steel or brass. A pattern film 23 made of a glass mask having In this state, exposure is performed by irradiating with ultraviolet light, and development and drying are performed. Here, the photoresist layer 22 is formed by laminating one or several negative type sheet-like photosensitive dry film resists and thermocompression-bonded to have a predetermined thickness. Next, the unexposed portion of the photoresist layer 22 is dissolved and removed, thereby obtaining a primary pattern resist 25 having a disk-shaped primary resist body 24 corresponding to the escape hole portion 17 as shown in FIG.

(Secondary patterning process)
As shown in FIG. 4C, a photoresist layer 26 is formed on the entire surface of the mother die 21 including the portion where the primary pattern resist 25 is formed, and a circular light transmitting hole corresponding to the holding hole 16 is formed on the upper surface thereof. A pattern film 27 made of a glass mask having At this time, the pattern film 27 is brought into close contact so that the center of the light transmitting hole coincides with the central axis Q1 of the primary resist body 24. In this state, exposure is performed by irradiating with ultraviolet light, and development and drying are performed. The photoresist layer 26 here is the same as the method for forming the photoresist layer 22 described above. Next, the unexposed portion of the photoresist layer 26 is dissolved and removed, so that a second secondary resist body 28 having a cylindrical secondary resist body 28 corresponding to the introduction hole portion 15 and the holding hole portion 16 is obtained as shown in FIG. Next pattern resist 29 is obtained. Since the center of the light transmitting hole of the pattern film 27 and the central axis Q1 of the primary resist body 24 coincide with each other, the central axis Q2 of the cylindrical secondary resist body 28 is the center of the disc-shaped primary resist body 24. It is located on the same axis as the axis Q1.

(Electroforming process)
As shown in FIG. 5 (a), the mother die 21 is put in a built-up electroforming tank, and as shown in FIG. The deposited metal is electrodeposited to form an electroformed layer 30, that is, a layer that becomes the mask body 10. At this time, the edge of the growth tip of the electroformed metal that grows over the upper edge of the primary resist body 24 grows in a quadrant shape. A shaped introduction hole 15 can be formed. As described above, an array mask having the array through-holes 12 having the bellmouth-like introduction hole portions 15 can be manufactured without the necessity of separately performing a process for forming the introduction hole portions 15 in the bellmouth shape. The manufacturing process of the mask for arrangement can be reduced by shortening the work process in the mask manufacturing process. Further, since the central axis Q2 of the secondary resist body 28 is positioned in the same axis as the central axis Q1 of the primary resist body 24, the cross-sectional shape of the introduction hole 15 is the same in the circumferential direction. Can be formed.

(Peeling process)
As shown in FIG. 5B, the electroformed layer 30 and the primary and secondary pattern resists 25 and 29 are peeled off from the matrix 21 and the primary and secondary pattern resists 25 and 29 are dissolved and removed. Thus, the mask main body 10 shown in FIG. 3 is obtained. The frame body 11 is adhered to the outer peripheral edge of the obtained mask main body 10 with an adhesive, and the both masks 10 and 11 are joined together in an integrated manner, whereby the arrangement mask 1 is obtained.

(Second Embodiment) FIGS. 6 and 7 show a second embodiment of the conductive pillar array mask according to the present invention. In the present embodiment, as shown in FIG. 6, the central axis P1 of the holding hole 16 is offset from the central axis P2 of the escape hole 17, and the cross-sectional shape of the introduction hole 15 is accordingly increased. The curvature is formed so as to gradually change from large to small from one side edge to the opposite side edge. More specifically, the cross-sectional shape of the introduction hole 15 is formed in a similar shape in the circumferential direction, and the curvature of the cross-sectional shape of the introduction hole 15 is the largest on the right side and the curvature on the left side in FIG. In the midway part from the right side to the left side of the introduction hole 15, the curvature gradually changes from large to small. The cross-sectional shape of the introduction hole portion 15 is formed in a perfect circular arc shape. The height dimension H3 of the introduction hole 15 in the present embodiment is a dimension at the position where the curvature is the smallest. Since others are the same as 1st Embodiment, the same code | symbol is attached | subjected to the same member and the description is abbreviate | omitted. The same applies to the following embodiments.

  FIG. 8 shows a method for manufacturing an array mask according to the second embodiment. The primary patterning process in the manufacturing method of this embodiment is the same as the method shown in FIGS. 4A and 4B described in the first embodiment.

(Secondary patterning process)
As shown in FIG. 8A, a photoresist layer 26 is formed on the entire surface of the mother die 21 including the portion where the primary pattern resist 25 is formed, and a circular light transmitting hole corresponding to the holding hole portion 16 is formed on the upper surface thereof. A pattern film 27 made of a glass mask having At this time, the entire pattern film 27 is brought into close contact with the center of the light transmitting hole and the center axis Q1 of the primary resist body 24 while being shifted to the right as viewed in FIG. In this state, exposure is performed by irradiating with ultraviolet light, and development and drying are performed. The photoresist layer 26 here is the same as the method for forming the photoresist layer 22 described above. Next, the unexposed portion of the photoresist layer 26 is dissolved and removed, so that a second resist body 28 having a columnar shape corresponding to the introduction hole portion 15 and the holding hole portion 16 is formed as shown in FIG. Next pattern resist 29 is obtained. Since the center of the light transmission hole of the pattern film 27 and the central axis Q1 of the primary resist body 24 are located at different positions, the central axis Q2 of the secondary resist body 28 is the central axis Q1 of the primary resist body 24. Is biased against.

(Electroforming process)
As shown in FIG. 8 (c), the mother die 21 is put in a bathed electroforming tank, and as shown in FIG. The deposited metal is electrodeposited to form an electroformed layer 30, that is, a layer that becomes the mask body 10. At this time, since the edge of the growth tip of the electroformed metal that grows over the upper edge of the primary resist body 24 grows in a semicircular arc shape, the electrodeposition metal is simply electrodeposited on the mother die 21 to form a bell. A mouse-like introduction hole 15 can be formed. Further, the longer the distance from the surface of the matrix 21 to the secondary resist body 28, the smaller the curvature of the quarter arc, so that the edge of the growth tip of the electroformed metal growing on the right side in FIG. 8C. The curvature of the edge of the growth tip of the electroformed metal growing on the left side is large. Thereby, the array through-hole 12 in which the curvature of the cross-sectional shape of the introduction hole portion 15 gradually changes from large to small in the circumferential direction can be easily formed only by performing the electroforming process. Further, since the central axis Q2 of the secondary resist body 28 is offset with respect to the central axis Q1 of the primary resist body 24, the central axis P1 of the holding hole portion 16 is offset from the central axis P2 of the escape hole portion 17. It can be formed in a biased arrangement.

(Peeling process)
As shown in FIG. 8D, after the electroformed layer 30 and the primary and secondary pattern resists 25 and 29 are peeled from the matrix 21, the primary and secondary pattern resists 25 and 29 are dissolved and removed. Thus, the mask main body 10 shown in FIG. 6 is obtained. The frame body 11 is adhered to the outer peripheral edge of the obtained mask main body 10 with an adhesive, and the both masks 10 and 11 are joined together in an integrated manner, whereby the arrangement mask 1 is obtained.

  As described above, when the cross-sectional shape of the introduction hole 15 is formed so as to gradually change from one side edge to the opposite other side edge in the circumferential direction, the conductive pillar 2 is formed on the side having a small curvature. In this case, the height guide H2 of the holding hole 16 can be increased on the side having a large curvature, and the positioning action of the conductive pillar 2 in the holding hole 16 can be greatly exerted. Therefore, the conductive pillars 2 can be partially dropped easily in the circumferential direction of the introduction hole 15, and the arrayed through holes 12 that can accurately position the dropped conductive pillars 2 can be obtained. Further, by forming the array through-holes 12 so that the side with the smaller curvature is oriented in the same direction, the squeegee is moved from the side with the smaller curvature toward the side with the larger curvature when the conductive pillar 2 is dropped. The conductive pillars 2 are dropped into the array through holes 12, and the mounting operation can be completed in a shorter time.

  In the present embodiment, the curvature is formed so as to gradually change from large to small from one side edge to the opposite other edge, but the portion having a large curvature in the circumferential direction of the introduction hole portion 15 and the curvature is small. The portions may be formed alternately and smoothly. In addition, it is good to form so that a curvature may change gradually from large to small or from small to large between a part with a large curvature and a small part. In this case, in the primary patterning step, the primary resist body 24 corresponding to the escape hole 17 is formed using the pattern film 23 made of a glass mask in which the light transmitting holes corresponding to the escape holes 17 are formed in a petal shape. A primary pattern resist 25 is formed. The subsequent steps are the same as those in the first embodiment. In this way, by forming the petal-shaped primary resist body 24, the timing at which the electrodeposited metal gets over the upper edge of the primary resist body 24 and contacts the secondary resist body 28 during the electroforming process is partially varied. be able to. As a result, the curvature of the edge of the growth tip of the electroformed metal previously in contact with the secondary resist body 28 can be increased, and the curvature of the edge of the growth tip of the other part can be reduced.

  Note that the arrangement mask (metal mask) of this embodiment can also be applied to metal masks such as an arrangement mask for conductive balls and a screen printing mask for forming a printed layer of conductive paste. Note that the same applies to the other embodiments.

(Third Embodiment) FIG. 9 shows a third embodiment of the conductive pillar array mask according to the present invention. In the present embodiment, as shown in FIG. 9, a plurality of support protrusions 35 formed in a columnar shape on the lower surface of the mask body 10 are integrally provided so as to avoid the escape hole portion 17 in the first embodiment. And different. The support protrusion 35 may be formed of a material made of the same metal as the mask body 10 or may be formed of a material made of another metal. It can also be formed of a non-magnetic material such as copper or resin. As described above, since the support protrusion 35 is provided on the lower surface of the mask main body 10, the contact between the work 3 and the mask 1 can be avoided as much as possible, and the mask 1 by placing the mask 1 on the work 3 and Damage to the workpiece 3 can be further suppressed. Further, the durability of the mask 1 can be further improved.

  In the above embodiment, the support protrusions 35 are provided so as to avoid the escape holes 17. However, the support protrusions 35 may be provided at regular intervals at positions corresponding to the dicing lines of the work 3 indicated by the one-dot chain line in FIG. You may provide only in the position corresponding to the intersection of a dicing line. The support protrusion 35 is not limited to a columnar shape but can be formed in a rib shape. When formed in a rib shape, a group of support protrusions 35 arranged in parallel may be formed, or the support protrusions 35 may be formed in a lattice shape.

  As described above, according to the conductive pillar array masks according to the above-described embodiments, the conductive pillars 2 are introduced and guided by the introduction holes 15 formed in a bell mouth shape so that the conductive pillars 2 can be arranged. Since it can drop smoothly into the hole 12, the mounting work of the conductive pillar 2 on the workpiece 3 can be completed in a short time. In addition, since the conductive pillars 2 dropped into the array through holes 12 are positioned by the holding holes 16 having a straight hole shape, the conductive pillars 2 in the array through holes 12 can be prevented from being tilted or displaced. The conductive pillar 2 can be mounted at a predetermined position on the 3 with high accuracy.

  In each of the above-described embodiments, the cross-sectional shape of the introduction hole portion 15 is formed in a quarter arc shape, but may be an elliptic quarter arc shape or a partially projecting arc shape. The escape hole portion 17 is not limited to a straight hole shape, but can be formed in a truncated cone shape or a stepped shape. In the case of forming a stepped hole shape, the primary resist body 24 may be formed in a stepped shape by dividing it twice.

2 conductive pillar 3 work 10 mask body 12 array through-hole 15 introduction hole 16 holding hole 17 escape hole 21 master mold 24 primary resist body 25 primary pattern resist 28 secondary resist body 29 secondary pattern resist 30 electroformed layer D1 Aperture diameter D3 Aperture diameter H1 Total height dimension of introduction hole and holding hole H2 Height dimension of escape hole H3 Height dimension of introduction hole H4 Height dimension of retention hole Q1 Central axis of primary resist body Q2 Center axis of secondary resist body

Claims (9)

This is an array mask in which cylindrical conductive pillars (2) are dropped into array through holes (12) corresponding to a predetermined array pattern, and the conductive pillars (2) are mounted at predetermined positions on the work (3). And
The array through-hole (12) opens on the surface of the mask body (10) and introduces and guides the conductive pillar (2) into the array through-hole (12). 15) a holding hole (16) provided on the lower side for positioning the conductive pillar (2), and the lower end of the introduction hole (15) and the upper end of the holding hole (16) are smoothly continuous. And
The introduction hole (15) is formed in a bell mouth shape that expands toward the surface side of the mask body (10),
The holding hole portion (16) is formed of a straight hole in which the opening diameter (D1) of the hole portion (16) is set slightly larger than the diameter of the conductive pillar (2). Mask for array of sex pillars.   The array through-hole (12) includes an escape hole (17) having an opening diameter (D3) larger than the opening diameter (D1) of the hole (16) below the holding hole (16). The conductive pillar array mask according to claim 1.   When the total height of the introduction hole (15) and the holding hole (16) is (H1) and the height of the escape hole (17) is (H2), the former height (H1) The mask for arranging the conductive pillars according to claim 2, wherein is set to be equal to or greater than the height dimension (H2) of the latter.   When the height dimension of the introduction hole (15) is (H3) and the height dimension of the holding hole (16) is (H4), the latter height dimension (H4) is the former height dimension (H3). The mask for arranging the conductive pillars according to any one of claims 1 to 3, wherein the mask is set to be equal to or larger than.   5. The conductive pillar array mask according to claim 1, wherein the curvature of the cross-sectional shape of the introduction hole portion (15) is changed in the circumferential direction of the introduction hole portion (15). .   The array of conductive pillars according to claim 5, wherein the curvature of the cross-sectional shape of the introduction hole portion (15) is formed so as to gradually change from one side edge to the opposite other side edge from large to small. mask. An array mask for mounting the conductive pillar (2) at a predetermined position on the work (3) by swinging the cylindrical conductive pillar (2) into the array through hole (12) corresponding to the predetermined array pattern. A manufacturing method comprising:
A primary patterning step of providing a primary pattern resist (25) having a primary resist body (24) corresponding to the escape hole (17) on the surface of the matrix (21);
A secondary patterning step of providing a secondary pattern resist (29) having a secondary resist body (28) corresponding to the holding hole (16) on the surface of the primary pattern resist (25);
An electroforming step of electrodepositing an electrodeposited metal on the matrix (21) to form an electroformed layer (30),
In the electroforming process, the electrodeposited metal is electrodeposited within a range not exceeding the upper end edge of the primary resist body (24) and not exceeding the upper end edge of the secondary resist body (28). ) Forming a mask for arranging conductive pillars.   In the secondary patterning step, the secondary pattern resist (29) is positioned with the central axis (Q2) of the secondary resist body (28) on the same axis as the central axis (Q1) of the primary resist body (24). A method for manufacturing a mask for arranging conductive pillars according to claim 7.   In the secondary patterning step, the secondary pattern resist (29) is arranged in a state where the central axis (Q2) of the secondary resist body (28) is offset from the central axis (Q1) of the primary resist body (24). A method for manufacturing a mask for arranging conductive pillars according to claim 7.

Images