JP2006019741A - Installation device and method for fine particles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device which shakes fine particles, such as solder balls, to the pattern of a mask easily. <P>SOLUTION: The device, which moves a head 20 on the surface of the mask 11, while rotating the head 20 around the axis, which is vertical to the mask 11, on the mask 11 having a pattern for arranging the fine particles, such as solder balls, at the specified position of a work, is provided. The head 20 has a plurality of squeegees 22 arranged around an internal circumference 26 of the rotation center. Each of the squeegees 22 moves the ball in the direction of the internal circumference 26, when the head 20 is rotated. Therefore, the density of the ball of the internal circumference 26 can always be kept high, regardless of the moving direction of the head 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus and method for arranging or arranging fine particles having a diameter of about 1 mm or less at a predetermined position, and in particular, conductivity used for mounting a semiconductor device or an optical device such as an integrated circuit device or a display panel. The present invention relates to an apparatus and a method suitable for arranging fine particles.

  When mounting semiconductor devices or optical devices such as LSI (Large Scale Integration) and LCD (Liquid Crystal Display), they are coated with solder or other conductive metals, and even metals to obtain electrical connections. A package or a substrate in which fine particles are arranged in a desired pattern is used. Japanese Patent Application Laid-Open No. 9-148332 describes that a minute particle is moved by using a brush-like moving means called a squeegee instead of using an air flow or vibration.

Japanese Patent Application Laid-Open No. 9-148332 discloses several types of squeegees. One type is a brush type in which conductive fibers are implanted, and the squeegee is reciprocated on the mask to move the microparticles in the form of a mask. In another type, instead of reciprocating the squeegee, a brush-like squeegee is rotated along the groove on a mask having a ring-like groove. Further, it is disclosed that a recess is provided on the surface in the moving direction of the squeegee so that the conductive fine particles can be easily inserted into the opening of the mask.
JP-A-9-148332

  When fine particles are transferred to the openings patterned in the mask with a squeegee or the like, a number sufficiently larger than the number of openings (density) is set so as not to generate openings where fine particles are not arranged. It is necessary to supply fine particles. However, if the time to move on the mask becomes longer, the microparticles will become smaller due to various factors, such as surface degradation due to contact with the atmosphere, particles to each other, particles to the mask, and friction and collision between the particles and the squeegee. Deteriorates and performance decreases. Therefore, it is necessary to discard the fine particles whose movement time has elapsed as a loss. In the type in which a linear brush-like squeegee is reciprocated, minute particle density tends to occur in the longitudinal direction of the squeegee, and if the fine particle density is increased in order to improve the yield, the loss rate of the fine particles increases. . The type in which the squeegee rotates inside the ring-shaped groove can increase the density of microparticles and reduce the loss rate of microparticles by making the front surface of the squeegee difficult to diffuse microparticles. there is a possibility. However, since it is necessary to prepare a ring-shaped mask and fine particles can be transferred only within the ring-shaped mask, the size or shape of the workpiece is limited. Or the transfer apparatus which arrange | positions a microparticle to a desired position becomes very large.

  Therefore, in the present invention, a fine particle moving head that can move freely in any of the XY directions on the mask while keeping the density of the fine particles constant is used. It is an object of the present invention to provide a method for arranging fine particles. And by using this head, it is a microparticle placement device that places microparticles on a workpiece, enabling mounting of small solder balls on bumps of a large-diameter semiconductor wafer, and high yield, At the same time, an object of the present invention is to provide a fine particle arrangement device with a small loss rate of fine particles.

  In the present invention, a head for moving fine particles on a mask having a pattern for arranging fine particles at a predetermined position, and a plurality of sweepers arranged around an inner circle. Each sweeper provides a head that moves microparticles in the direction of the inner circle. This head collects excess microparticles remaining on the mask in the direction of the inner circle of the head. Therefore, even if the head is moved in any direction of XY on the mask, excess microparticles are collected in the inner circle, so the density of the microparticles in the inner circle increases, and the portion through which the inner circle passes The probability of transfer of fine particles to the mask pattern increases.

  The head of the present invention collects excessive fine particles in the inner circle of the head that does not depend on the traveling direction of the head. For this reason, the head of the present invention has a microparticle placement method including a step of placing microparticles by moving along the surface of a mask provided with a pattern for placing microparticles at a predetermined position. The yield of workpieces where particles are placed can be improved, and at the same time, by increasing the density of minute particles in a limited area called the inner circle, the time required for the fine particles to move without being transferred to the mask pattern can be reduced. The loss rate of fine particles can also be reduced.

  The fine particle arrangement device of the present invention includes a head of the present invention for moving a fine particle on a mask having a pattern for arranging the fine particle at a predetermined position of the work, and the head on the surface of the mask. Head moving means for moving along the head. One form of a head that collects fine particles in the inner circle direction is movable while rotating around an axis perpendicular to the mask, and the head has an inner circle area at the center of rotation. Is equipped with a sweeper that moves the microparticles in the direction of the inner circle when rotating. One form of such a sweeper is that when the head rotates, the surface of the mask moves while being in contact with at least part of the surface, and the fine particles present on the mask are removed while pushing away the fine particles. Can move in the direction of the inner circle. One of such sweepers is a squeegee, and is provided with a member that is arranged at least in the moving direction of the sweeper and pushes away in contact with the fine particles. Further, the sweeper may output a gas for blowing off fine particles on the surface of the mask.

  A sweeper of a type that pushes out fine particles onto the fine particles like a squeegee can obtain a force for driving the fine particles as the head rotates. Therefore, the fine particles can be moved in the direction of the inner circle by rotating the head. On the other hand, a sweeper of a type that blows off fine particles with gas can obtain a force for driving the fine particles by blowing out the gas. Therefore, the head may be rotated, but the fine particles can be moved in the direction of the inner circle only by moving the head along the surface of the mask without rotating the head.

  The sweeper may be any arrangement or shape that moves the microparticles in the direction of the inner circle. For example, there are a spirally curved shape and a shape that is directed toward the center of rotation with respect to the radial direction. The sweeper extending in the tangential direction of the inner circle is one example of a linear shape sweeper that can move microparticles in the direction of the inner circle efficiently.

  It is desirable to further have a supply means for supplying fine particles in the range of the inner circle. This head collects excessive fine particles in the direction of the inner circle. Therefore, the amount of excess microparticles on the surface of the mask is consumed by supplying the microparticles so that the density of the microparticles in the inner circle can be detected by an appropriate method such as an optical sensor and kept constant. An appropriate amount of fine particles corresponding to the fine particles can be replenished.

  Preferred examples of the fine particles in the present invention are particles for connection used in mounting a semiconductor device or an optical device, and are solder balls, gold balls, or copper balls having a diameter of about 30 to 300 μm.

  As described above, the head of the present invention can collect the minute particles excessively left on the mask in the inner circle of the head regardless of the moving direction of the head. Therefore, by using the head of the present invention, for example, by scanning the mask in the X direction and sub-scanning in the Y direction, a large area mask can be used for a large work or many works in a short time. It becomes possible to mount fine particles efficiently. In the present invention, the shape of the mask is not limited to the ring shape, and may be any shape. Therefore, according to the present invention, it is possible to provide a microparticle placement device with high yield and low microparticle loss. Further, it is possible to provide a fine particle arrangement device with a compact design that can use a mask having a flexible shape.

  The present invention will be further described with reference to the drawings. FIG. 1 shows a schematic configuration of a fine particle arrangement device according to the present invention. This apparatus 1 is called a ball mounter and can mount a small solder ball or the like on a work such as a semiconductor substrate or a printed board. The ball mounter 1 includes a platform 2 on which a workpiece 10 can be set horizontally, a head 20 that rotates horizontally on a mask 11 stacked on the surface of the workpiece 10, and a motor 30 that rotationally drives the head 20. A carriage 42 that moves the head 20 and the motor 30 along the carriage shaft 41 in the X direction of the base 2 and a shaft moving mechanism 43 that moves the carriage shaft 41 in the Y direction of the base 2 are provided. The workpiece 10 is, for example, an 8-inch semiconductor wafer.

  The head 20 includes a disk-shaped squeegee support 21 and six sets of squeegees 22 arranged on the lower surface of the squeegee support 21. A rotation shaft 25 extending perpendicularly to the mask 11 is attached to the center of the squeegee support 21 and is rotated clockwise when the squeegee support 21 is viewed from above by a rotation driving motor 30. ing. Therefore, in this fine particle arrangement device 1, the rotation center of the head 20, that is, the rotation shaft 25, is rotated by using the shaft moving mechanism 43, the carriage 42, and the rotation driving motor 30 as the head moving means. The board 2 can move in any of the XY directions.

  Further, the carriage 42 is equipped with a ball supply device 50 that supplies fine particles to be moved by the head 20 from the center of the squeegee support 21 onto the mask 11 via the inside of the rotary shaft 25. In this example, a solder ball having a diameter of 150 μm is supplied onto the mask 11 and arranged on the workpiece 10 in accordance with a pattern formed on the mask 11.

  FIG. 2 shows the arrangement of six sets of squeegees 22 attached to the lower surface of the squeegee support 21 in a state where it is seen through from above the squeegee support 21. FIG. 3 shows a cross section of the head 20 cut along the diameter direction of the squeegee support 21. As shown in FIG. 3, each squeegee 22 has a configuration in which a plurality of sweep members 23 are arranged in a multiple manner in the traveling direction of the squeegee 22. More specifically, as shown in an enlarged view in FIG. 4, a plurality of sweep members 23 are attached to the support 21 so that the distal ends thereof are retracted with respect to the traveling direction A of the squeegee 22. The sweep member 23 moves the solder ball 19 on the mask 11 while sweeping it in the advancing direction A or sweeps it, and inserts the solder ball 19 into the pattern 12 such as an opening formed in the mask 11. To do.

  The mask 11 is laminated on the surface 10 a on which the solder balls 19 are mounted on the surface of the work 10 via a resist 13, and the resist 13 is removed only in the pattern 12 portion. Therefore, the solder balls 19 inserted into the pattern 12 come into contact with the connection layer 10a of the workpiece 10, and the individual solder balls 19 function as connection terminals.

  The sweep member 23 only needs to be able to push out fine particles that function as connection terminals such as solder balls 19, for example, solder balls, gold balls, or copper balls having a diameter of about 30 to 300 μm with an appropriate force. Further, it is desirable that the ball 19 once inserted into the pattern 12 has elasticity enough to prevent the ball 19 from being scraped. One suitable sweep member 23 is a resin or metal wire extending in the longitudinal direction of the squeegee 22. By adopting a configuration in which both ends of the wire extending in the longitudinal direction along the surface of the mask 11 are bent into a U shape and attached to the squeegee support 21, the belly portion of the wire comes into contact with the mask 11. Therefore, the sweep member 23 can be pressed against the mask 11 without damaging the mask 11 and having an appropriate elasticity, and the solder ball in the mask hole is not scraped off at the tip of the wire. The member that pushes off the ball 19 in a state extending in a direction orthogonal to the traveling direction of the squeegee 22 can be used. Then, by attaching a plurality of wires to the squeegee support 21 as the sweep members 23 so as to be multilayered with respect to the traveling direction of the squeegee 22, the excessively remaining ball 19 on the mask 11 is almost in front of the squeegee 22. It can be surely swept out. Further, in the head 20 of this example, the squeegee support 21 to which the plurality of squeegees 22 are attached rotates, so that the ball 19 leaking from one squeegee 22 can be surely pushed away in a desired direction.

  Another preferable example of the sweep member 23 is a thin film made of resin or metal, and the ball 19 is pushed away in the same manner as described above by being attached to the squeegee support 21 so as to extend in the longitudinal direction of the squeegee 22. Can do. The tip portion of the thin film in contact with the mask 11 may be an edge, or the thin film surface may be in contact with the mask 11 by folding the thin film. Still another example of the sweep member 23 is a squeegee support 21 in which a fine wire made of resin or metal is attached to the squeegee support 21 like brush hair.

  As shown in FIG. 2, in the head 20 of this example, the disk-shaped squeegee support 21 attached to the back surface, that is, the side facing the mask 11 has a rotating shaft 25 perpendicular to the mask 11. Move while rotating around. The six sets of squeegees 22 are each constituted by a sweep member 23 attached so as to be rectangular when viewed from above, and these squeegees 22 are arranged around an inner circle 26 coaxial with the rotary shaft 25 in the circumferential direction. Are arranged so as to extend linearly to the outer circle 27 in the clockwise direction in the tangential direction of the inner circle 26 at an equal pitch. Therefore, when the squeegee support 21 is rotated clockwise as viewed from above, the squeegee 22 pushes the solder ball 19 in the traveling direction so as to move in the direction of the inner circle 26 as indicated by the arrow 18. Accordingly, the head 20 rotates to collect the excess solder balls 19 remaining on the mask 11 within the range of the outer circle 27 in the direction of the inner circle 26 at the center of the head 20.

  The head 20 is reciprocated in the X direction by the carriage 42 and moved at an appropriate speed in the Y direction by the shaft moving mechanism 43, so that the head 20 is scanned on the mask 11 in the X direction and the Y direction is sub-scanned. The head 20 can be moved so as to cover the entire area of the mask 11. The function of collecting the balls 19 of the head 20 on the inner circle 26 does not change even if the head 20 is moved in any direction of XY on the mask 11. Therefore, excessive solder balls 19 on the mask 11 can always be collected in the inner circle 26 while the head 20 is moving, and the density of the solder balls 19 in the inner circle 26 can be increased. Also, the solder balls 19 in the outer circle 27 can be collected in the inner circle 26. For this reason, the diameter of the outer circle 27 is set to about three times the diameter of the inner circle 26 and the head 20 is sub-scanned at a pitch within the diameter of the inner circle 26, so that the solder balls 19 are not leaked from the head 20. It can be collected in the area of the circle 26.

  The moving direction of the head 20 is not limited to the above. For example, if the workpiece 10 and the mask 11 are disk-shaped, the entire surface of the mask 11 can be covered also by moving the head 20 so as to draw a spiral in the circumferential direction of the mask 11. Even in such a case, the solder balls 19 are collected on the inner circle 26 of the head 20 in the same manner as described above by moving the central shaft 25 in a spiral manner while rotating the head 20 clockwise. be able to. The density of the solder balls 19 in the inner circle 26 can be increased, and the recovery rate of the solder balls 19 can be increased.

  As described above, the head 20 of this example can collect the excessive solder balls 19 in the inner circle 26 regardless of the moving direction of the head 20 and increase the density of the solder balls 19 existing in the inner circle 26. Therefore, the solder balls 19 can be efficiently transferred to the pattern 12 of the mask 11 through which the inner circle 26 passes, and the yield can be improved. At the same time, the time (remaining time) during which the solder ball 19 moves without being transferred to the pattern 12 can be shortened. For this reason, it is possible to reduce the loss due to the deterioration of the quality due to the remaining time of the solder balls 19 being too long.

  Furthermore, since the head 20 can always collect the excessive solder balls 19 in a limited area of the inner circle 26, the pattern of the mask 11 is monitored by monitoring the state of the solder balls 19 collected in the inner circle 26. It is possible to control the situation in which the solder ball 19 is transferred to 12. For example, if the density of the solder balls 19 in the inner circle 26 decreases due to the solder balls 19 being transferred to the pattern 12 and consumed, the probability of being transferred to the pattern 12 may decrease. In that case, as shown in FIG. 3, the density of the solder balls 19 in the inner circle 26 is detected by the optical sensor 51, and a new solder ball 19 is removed from the ball supply device 50 so as to maintain an appropriate density. 26. Further, when the ball 19 needs to be recycled, it is possible to provide a function of collecting the ball 19 from the inner circle 26 and recycling it.

  The arrangement and the number of squeegees 22 for collecting the balls 19 in the direction of the inner circle 26 by the rotation of the head 20 are not limited to this example. The squeegee 22 may be arranged with a wider angle in the radial direction than the tangential direction of the inner circle 26. However, if the angle of the squeegee 22 is larger than the radial direction of the inner circle 26, the squeegee 22 is not preferable because the squeegee 22 moves in the direction of diffusing the ball 19 around when the head 20 rotates. Further, the squeegee 22 may itself be curved, and each squeegee 22 can be arranged to draw a spiral.

  Further, the means for sweeping the solder ball 19 in the direction of the inner circle 26 is not limited to the squeegee that pushes the ball 19 off, and may be a type that blows off the ball 19 with an appropriate gas. An example is shown in FIG. The air nozzle 62 shown in FIG. 5 is attached to the support 21 instead of the squeegee 22, and is made of sintered metal from a tip 63 extending to the outer circle 27 in the tangential direction of the inner circle 26, similar to the squeegee 22. The air 65 is output along the surface of the mask 11 through the filter 64. Even with this type of sweeping means, it is possible to move the solder ball 19 along the air nozzle 62 by air 65 while blowing it away in the direction of the inner circle 26. In addition to the filter 64, the air discharge part of the air nozzle 62 may be a set of slits and minute cylindrical holes. The air may be nitrogen gas, argon gas or ionized gas.

  In the head 20 provided with the air nozzle 62, the solder ball 19 can be driven by the air blowing pressure. Therefore, in the step of placing the solder ball 19 at a predetermined position of the workpiece by the ball mounter 1, the head 20 may be rotated to drive the solder ball 19, but the inner circle 26 may be soldered without rotating. The balls 19 can be assembled. Therefore, in the ball mounter 1 using this head, the motor 30 that rotationally drives the head 20 can be omitted. Therefore, as a function capable of moving the head 20, a mechanism for rotationally driving is unnecessary, and any mechanism including the shaft moving mechanism 43 and the carriage 42 may be used. Therefore, it is possible to provide a ball mounter having a simpler mechanism.

It is a figure which shows schematic structure of the ball mounter of this invention. In order to show the configuration of the head, FIG. It is a figure which shows the cross section of a head. It is a figure which expands and shows a squeegee. It is a figure which shows the air nozzle replaced with a squeegee.

Explanation of symbols

1 Ball mounter (fine particle placement device)
19 Solder ball 20 Head 21 Squeegee support 22 Squeegee

Claims (17)

A head for moving the microparticles on a mask having a pattern for arranging the microparticles at a predetermined position of the workpiece;
A microparticle placement device having a head moving means for moving the head along the surface of the mask,
The head includes a plurality of sweepers arranged around an inner circle, and each sweeper moves the microparticles in the direction of the inner circle. The head moving means according to claim 1, wherein the head moving means moves while rotating the head around an axis perpendicular to the mask,
The head has the inner circle at the center of rotation, and the sweeper moves the microparticles in the direction of the inner circle when the head rotates.   3. The fine particle arrangement device according to claim 2, wherein when the head rotates, the sweeper moves while at least partly contacting the surface of the mask.   4. The microparticle placement apparatus according to claim 2, wherein the sweepers are arranged in multiple directions at least in the moving direction of the sweeper and include members that push away in contact with the microparticles.   2. The fine particle placement device according to claim 1, wherein the sweeper outputs a gas for blowing off the fine particles on the surface of the mask.   The fine particle arrangement device according to claim 1, wherein the sweeper extends in a tangential direction of the inner circle.   The fine particle arrangement device according to claim 1, further comprising supply means for supplying the fine particles within a range of the inner circle.   2. The fine particle placement device according to claim 1, wherein the fine particles are solder balls, gold balls, or copper balls having a diameter of about 30 to 300 [mu] m. A head for moving the microparticles on a mask having a pattern for arranging the microparticles at a predetermined position,
A head that is movable along the surface of the mask and further includes a plurality of sweepers arranged around an inner circle, and each sweeper moves the fine particles in the direction of the inner circle.   10. The head according to claim 9, wherein the head is movable while rotating around an axis perpendicular to the mask, and further, the sweeper moves the fine particles in the direction of the inner circle when the head rotates. Let the head.   11. The head according to claim 10, wherein the sweeper moves while at least part of the surface of the mask is in contact with the surface of the mask when the head rotates.   The head according to claim 9, wherein the sweeper outputs a gas for blowing off the fine particles on the surface of the mask.   A method for arranging microparticles, the method comprising: arranging the microparticles by moving the head according to claim 9 along the surface of a mask having a pattern for arranging the microparticles at a predetermined position.   14. The positioning step according to claim 13, wherein in the step of arranging, the head is moved while rotating about an axis perpendicular to the mask, and the sweeper rotates the head to rotate the minute particles to the inner circle. A method for arranging microparticles that move in the direction of.   15. The method for arranging fine particles according to claim 14, wherein in the arranging step, the sweeper is moved so as to be in contact with at least a part of the surface of the mask.   14. The method for arranging fine particles according to claim 13, wherein in the arranging step, a gas for blowing off the fine particles is output from the sweeper to the surface of the mask.   14. The method for arranging fine particles according to claim 13, wherein the fine particles are solder balls, gold balls or copper balls having a diameter of about 30 to 300 [mu] m.

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