JP5141966B2 - Micro ball array device - Google Patents

Description

  According to the present invention, the ball insertion portion is moved to move along the upper surface of the arrangement portion having a region in which the ball insertion portion is formed in a predetermined arrangement pattern. The present invention relates to an improvement of a microball arrangement device that drops and arranges, and in particular, is a microball arrangement device that was developed mainly to drop a microball from a ball housing portion to a ball insertion portion reliably and appropriately.

  Conventionally, there has been a solder ball mounting device for mounting a solder ball on each electrode formed in a predetermined arrangement pattern on a mounting target as a micro ball mounting device. In this type of solder ball mounting apparatus, the solder balls are miniaturized and the products to be mounted such as wafers are increased in size, and the number of solder balls to be mounted at one time is increased. The risk of the occurrence of defects has increased and it has been sought to reduce this risk.

  Therefore, as shown in Patent Document 1, an arrangement jig such as an arrangement mask is provided on a wafer that is a mounting object on which flux is printed, and the ball cup on which the ball accommodating portion is formed moves on the arrangement jig. There has been provided an apparatus for dropping a solder ball directly onto a wafer electrode from a ball housing portion of a ball cup. In the case of such an apparatus, the larger the wafer, the longer the movement distance of the ball cup and the longer the time required for mounting. Therefore, if the movement speed of the ball cup is increased, the ball cup is moved as shown in FIG. 4, the stacking of the solder balls 1 becomes high along the inner wall surface 14 of the ball accommodating portion 8 on the rear side in the direction of travel 4 (arrow direction in FIG. 7).

  On the other hand, the dropping of the ball into the ball insertion portion is performed from the front side in the traveling direction of the ball group, and is performed to the rear side so as to fill the missing part.

  If the ball is not inserted into the ball insertion portion until it reaches the vicinity of the rear inner wall surface of the ball cup 4, the ball tends to fall at a portion where the stack is high, but the balls 1a, 1b, 1c are strongly hit each other as shown in FIG. The balls 1c did not easily fall down to the bottom, and biting was likely to occur.

Japanese Patent Laid-Open No. 2007-299835

The present invention focuses on the following points, and an object thereof is to provide a microball array device capable of dropping a microball from the ball housing portion to the ball insertion portion surely and properly without eliminating the biting of the ball.
First, since the microballs do not come into strong contact with each other in the ball housing portion, the group of microballs is dispersed to increase the number of places where there is little stacking.
Secondly, the minute ball is dropped into the ball insertion portion as far as possible from the inner wall surface of the ball housing portion, and when the inner wall surface approaches, the minute ball is already filled so that it is not necessary to drop the minute ball.

In order to solve the above-mentioned problem, the first invention accommodates a large number of microballs along the upper surface of the array part having a region in which a ball insertion part capable of accommodating one microball is formed in a predetermined array pattern. The following means is adopted for the microball arraying apparatus that drops and arranges the microballs in the ball insertion section by moving the ball receiving section.
First, a plurality of ball housing portions are provided along the traveling direction of the ball housing portion.
Second, each of the plurality of ball receiving portions is configured such that the ball insertion portion overlaps with an area formed in a predetermined pattern.

Third, among the plurality of ball housing portions, the ball housing portion forward in the traveling direction has an opening on the bottom surface, and the rear edge in the traveling direction of the opening portion travels from both sides in the direction orthogonal to the traveling direction. It is assumed that it is formed in a mountain shape toward the rear .

The second invention, the first inventions, the plurality of ball receiving portion is a small ball array device added that one formed on the ball cup singular, the third invention, the 1 of the invention or the second inventions, the plurality of ball receiving portion is a small ball array device obtained by adding the one having a detecting means for detecting a ball weight.

  In the present invention, there are provided a plurality of ball accommodating portions that act in an overlapping manner with respect to the moving direction of the ball accommodating portion, and each of the ball accommodating portions overlaps a region where the ball insertion portions are formed in a predetermined pattern. Since the ball passes through, the small balls do not come into strong contact with each other in each ball accommodating portion, and there are many places where the small balls are easy to fall, and the biting of the fine balls is reduced.

Further , among the plurality of ball housing portions, the ball housing portion forward in the traveling direction has an opening on the bottom surface, and the rear edge in the traveling direction of the opening faces from the both sides in the direction orthogonal to the traveling direction toward the rear in the traveling direction. Even in the case of using a circular mounting area with many ball insertion parts in the center like a wafer as the object to be mounted, the reduction method of minute balls is equalized. We were able to.

Although it is the effect of 2nd invention, it is set as the apparatus similar to the case where one ball accommodating part is used conventionally by making a several ball accommodating part into a single ball cup. As a result of the third aspect of the invention, the plurality of ball housing portions have a detecting means for detecting the amount of balls, so that it is possible to know the replenishment time of the minute balls, and there is a shortage of minute balls. This makes it possible to prevent ball mounting mistakes.

  Hereinafter, embodiments of the present invention will be described together with examples according to the drawings. The embodiment is a solder ball mounting apparatus, and the solder ball mounting apparatus has a carry-in wafer transfer section, a flux printing section, a ball mount section, and a carry-out wafer transfer section. The microball array device according to the present invention corresponds to the ball mounting portion of the solder ball mounting device.

  The fine balls in the present invention include conductive balls such as solder balls and platinum balls, and examples of objects on which the fine balls are mounted include semiconductor wafers (hereinafter simply referred to as wafers), electronic circuit boards, ceramics, and the like. Although there are substrates and the like, in the embodiment, solder balls 1 and wafers 2 are used. Further, as an adhesive material for mounting the solder ball 1 on the wafer 2, a flux, a solder paste, a conductive adhesive or the like is used. In the embodiment, a flux is used, and the solder ball 1 is placed. A flux is previously applied on each electrode of the wafer 2.

  The ball mounting portion in the embodiment includes a wafer mounting table on which the wafer 2 is mounted, a ball cup 4 for supplying the solder balls 1, and an array mask for inserting the solder balls 1 into a predetermined array pattern. 3 and a ball cup moving device 5 for moving the ball cup 4 along the upper surface of the array mask 3. The wafer mounting table includes an elevating mechanism, and when the solder balls 1 are arranged, the wafer 2 is raised so that the solder ball mounting surface of the wafer 2 and the lower end surface of the arrangement mask 3 are at a predetermined interval. ing.

  The array mask 3 has a through-hole forming region 6 (shown in FIG. 1) in the center where one solder ball 1 which is a micro ball can be inserted as shown in FIG. The holes 7 are formed in a predetermined arrangement pattern that matches the electrodes on the upper surface of the wafer 2. The arrangement mask 3 corresponds to the arrangement portion in the present invention, and the through hole 7 corresponds to the ball insertion portion in the present invention.

  The array mask 3 in the embodiment is formed in a quadrangular shape as shown in FIG. In addition, a tension is applied to the four corners of the square array mask 3 after tension is applied to the array mask 3 itself, and a holding block member is attached to increase the plane accuracy of the array mask 3. The solder mask 1 is formed on the upper surface of the wafer 2 and is supported by the array mask support device above the mounting surface of the solder balls 1 with an appropriate interval.

  The height of the arrangement mask 3 in the embodiment is set to a height at which the upper part of the solder ball 1 inserted into the through hole 7 does not protrude from the upper surface of the arrangement mask 3 as shown in FIG. Of course, the upper part of the solder ball 1 inserted into the through-hole 7 may protrude, but in this case, the bottom surface portion passing through the through-hole forming region 6 of the ball cup 4 does not contact the ball in the through-hole 7. It is necessary to do so. The array mask 3 may be brought into contact with the wafer 2. In that case, the diameter of the through hole 7 on the wafer 2 side is increased so that the flux does not contact the array mask 3, or ribs or protrusions are provided so as not to reach the through hole 7 on the lower surface of the array mask 3. Take measures.

  The ball cup 4 into which the solder balls 1 are dropped into the through-holes 7 of the array mask 3 is formed with three ball receiving portions 8A, 8B, 8C that overlap with the moving direction of the ball cup 4 (vertical direction in FIG. 1). Has been. As the ball accommodating portions 8A, 8B, and 8C pass over the through-hole forming region 6 of the arrangement mask 3, as a result, the hatched portions in FIG. 5 and FIG. As shown in FIG. 5A, the ball accommodating portions 8A, 8B, and 8C can secure a wide portion where the balls are easy to fall and have little stacking. The ball accommodating portions 8A, 8B, and 8C are not necessarily formed in the single ball cup 4, but are formed in one ball cup 4 in the embodiment.

  Each of the ball accommodating portions 8A, 8B, and 8C has an opening 9A for supplying a ball at the upper portion, and an opening 9B for dropping the ball at the lower surface. The opening 9B on the lower surface is formed in a direction perpendicular to the traveling direction and wider than the width of the through-hole forming region 6 of the array mask 3, and the ball accommodating portions 8A, 8B, 8C and the array mask 3 A large number of solder balls 1 can be accommodated on the upper surface. The ball cup 4 itself is formed with a width narrower than the width of the array mask 3 as shown in FIG.

  The shape of the opening 9B on the lower surface of the ball accommodating portions 8A, 8B, and 8C may be rectangular, and generally rectangular, but in the embodiment, the mounting object is the wafer 2, and the solder ball 1 and the corresponding through-hole formation region 6 of the arrangement mask 3 are substantially circular. Therefore, if the shape is rectangular, the solder balls 1 in the central portion 12 are quickly reduced. There will be a difference in how to decrease. In such a situation, it is necessary to provide a number of remaining amount detection means and ball replenishment means for the solder balls 1.

  Therefore, among the ball accommodating portions 8A, 8B, and 8C, the ball accommodating portions 8A and 8C that are forward in the traveling direction proceed from both side portions 12 in which the traveling direction rear edge 11 of the opening 9B on the bottom surface is orthogonal to the traveling direction. It is formed in a mountain shape rearward in the direction. In other words, the rear edge 11 in the traveling direction of the bottom opening 9B is swelled from both side portions 12 orthogonal to the traveling direction toward the rear in the traveling direction.

  As a result, the ball accommodating portions 8A and 8C that are forward in the traveling direction can accommodate more solder balls 1 in the central portion 13 than in the both side portions 12 by proceeding. As a result, the solder balls 1 are evenly reduced in the direction perpendicular to the traveling direction of the ball housing portion.

  The intermediate ball storage portion 8B is for replenishing a portion where a drop has occurred due to a ball dropping operation from the ball storage portion 8A in the front in the traveling direction, and both side portions in a direction perpendicular to the traveling direction where the drop is likely to occur. 12 is formed into a wide drum shape. Even if the ball housing portion 8A passes and a dropout occurs, the ball housing portion 8B that passes thereafter has a portion where the balls are likely to fall on the front side in the advancing direction, so that the balls are replenished without being bitten. It will be. In the case of progression from the state shown in FIG. 1, since the progression proceeds upward in FIG. 1, the ball housing portion 8A is forward in the traveling direction, and the ball housing portion 8C at the rear in the traveling direction also functions as a dropout supplement. It will be a thing. Further, since the ball cup 4 moves forward and backward, the ball housing portion 8C is forward in the traveling direction during the backward movement.

  Remaining amount sensors 10A, 10B, and 10C, which are detection means for detecting the amount of balls, are provided at the center of the plurality of ball housing portions 8A, 8B, and 8C. When the remaining amount sensors 10A and 10B travel upward in FIG. 1, only the ball accommodating portion 8A in the forward direction and the intermediate ball accommodating portion 8B need be operated. A ball supply port is installed at the same position as the remaining amount sensor 10. When the remaining amount sensors 10A, 10B, and 10C detect that the remaining amount of the balls in the ball housing portions 8A, 8B, and 8C has decreased, the solder balls 1 are replenished from the ball supply port. In the ball accommodating portions 8A, 8B, and 8C, since the number of the accommodated solder balls 1 is equalized, it is only necessary to provide one detecting means for each.

  The ball cup moving device 5 that moves the ball cup 4 forward and backward includes a cup holder 16 that applies a moving force in the front-rear direction to the ball cup 4, a driving device 17 that moves the cup holder 16, and movement of the cup holder 16. And a guide plate 18 that guides.

  The cup holder 16 is formed with an empty portion in which the ball cup 4 is disposed, and the ball cup 4 is lightly held in the empty portion by a weak force of urging the slide roller 22 and the spring 26. ing.

  The drive device 17 moves the cup holder 16 holding the ball cup 4 back and forth above the arrangement mask 3 by a ball screw rotated by a drive motor 19. The cup holder 16 is attached to the drive device 17. It is installed.

  Reference numeral 18 in FIG. 1 denotes a frame-shaped guide plate 18 that surrounds the arrangement mask 3, and guide rails 20 are provided on both sides along the moving direction of the ball cup 4, and the cup holder 16 is attached to the guide rail 20. It is slidably arranged. The drive device 17 causes the cup holder 16 to move forward and backward along the guide rail 20.

  By this movement, the ball cup 4 moves along the upper surface of the array mask 3, and the ball accommodating portions 8A, 8B, 8C of the ball cup 4 pass over the through holes 7 of the array mask 3 in an overlapping manner. The solder balls 1 are surely dropped into the through holes 7 and arranged. In addition, although the ball cup moving apparatus 5 in an Example is only the thing for the front-back direction, the moving means to the left-right direction is provided as needed.

  The guide plate 18 is longer than the array mask 3 in the front-rear direction, the tip in the cup advance direction is an empty portion, and the ball receiver 21 is disposed below the empty portion. Therefore, at the time of arrangement, the ball cup 4 stops on the arrangement mask 3 in front of the ball receiver 21 and reverses and moves backward. On the other hand, at the time of replacement of the array mask 3, the ball cup 4 moves to above the ball receiver 21 and drops the solder ball 1 accommodated in the ball receiver 21. Reference numeral 27 in the drawing denotes a cup moving path for supporting the ball cup 4 when the ball cup 4 is discharged to the ball receiver 21.

  In the embodiment, the three ball housing portions 8A, 8B, and 8C are provided. However, the intermediate ball housing portion 8B may not be provided, and two ball housing portions 8A and 8C may be used. Further, the above embodiment is a solder ball mounting apparatus in which the solder balls 1 are directly mounted on the wafer 2 from the array mask 3, but the present invention is an array apparatus as shown in Japanese Patent No. 2925534, that is, A solder ball mounting device that inserts solder balls into the holding holes of the temporary array plate and arranges them, and then picks up the solder balls with a suction head that is a metal ball arraying jig and mounts them on the mounting target. It is.

Schematic plan view showing the ball arrangement part of the arrangement device Top view of ball cup Central cross section of the ball cup Center vertical section of the ball cup Cross-sectional explanatory drawing showing the distribution state of solder balls in the ball housing part Plane explanatory view showing the distribution of solder balls in the ball housing Cross-sectional explanatory drawing showing the distribution state of solder balls in the conventional ball housing Explanatory drawing which shows the relationship between the solder balls in the conventional ball container

Explanation of symbols

1. . . . . . Solder balls . . . . . Wafer 3. . . . . . Array mask 4. . . . . . 4. Ball cup . . . . . Ball cup moving device 6. . . . . . 6. Through-hole formation region . . . . . Through-hole 8, 8A, 8B, 8C. . . . . . Ball housing part 9A, B. . . . . . Openings 10A, 10B, 10C. . . . . . 10. Ball remaining amount detection sensor . . . . Rear edge 12. . . . . Side 13. . . . . Central part 14. . . . . Inner wall surface 16. . . . . Cup holder 17. . . . . Drive device 18. . . . . Guide plate 19. . . . . Drive motor 20. . . . . Guide rail 21. . . . . Ball receiver 22. . . . . Slide roller 26. . . . . Spring 27. . . . . Cup travel path

Claims (3)

The ball insertion portion can be inserted by moving the ball storage portion containing a large number of microballs along the upper surface of the arrangement portion having a region in which a ball insertion portion capable of accommodating one microball is formed in a predetermined arrangement pattern. In a microball array device that drops and arranges microballs in the part,
A plurality of ball housing portions are provided along the traveling direction of the ball housing portion,
Each ball accommodating portion is configured to pass through the region where the ball insertion portion is formed in a predetermined pattern ,
Of the plurality of ball housing portions, the ball housing portion forward in the traveling direction has an opening on the bottom surface, and the rear edge in the traveling direction of the opening portion is directed from both sides in the direction orthogonal to the traveling direction toward the rear in the traveling direction. A microball array device characterized by being formed in a mountain shape . The microball array device according to claim 1, wherein the plurality of ball housing portions are formed in a single ball cup . 3. The microball array device according to claim 1 or 2, wherein one detecting means for detecting a ball amount of the ball housing portion is provided for one ball housing portion .

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