JP2010050269A - Minute ball loading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably transmit vibration of a vibrating means to an array mask by vibrating an abutment member disposed to surround an object to be loaded by the vibrating means and pressing the tensioned array mask to the abutment member having a wide area. <P>SOLUTION: The following means are adopted for a minute ball loading apparatus, namely firstly the array mask is provided, where the array mask is disposed at an upper portion of an object to be loaded while an insertion section of the minute ball is formed at a ball loading section, and a means for giving vibration to the mask is provided, secondly the minute ball is dropped to the insertion section of the array mask by moving a group of minute balls along an upper surface of the array mask for loading onto the object to be loaded during vibration of the array mask by the vibrating means, thirdly an abutment member disposed to surround the object to be loaded is provided and the abutment member is vibrated by the vibrating means, and fourthly the array mask is vibrated by pressing the tensioned array mask by the abutment member. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an improvement of a microball mounting device, and more particularly, a microball mounting device that mounts microballs using an array mask in which microball insertion portions are formed corresponding to the mounting locations of the object to be mounted. About.

  In a microball mounting apparatus for mounting a microball on an object to be mounted by dropping a microball into an insertion portion of the array mask by moving a ball cup containing a large number of microballs along the upper surface of the array mask. As shown in FIG. 4, the minute balls (solder balls 2) inside are gathered on the rear side in the direction of travel of the ball cup 4, and the minute balls (solder balls 2) are smoothly dropped into the insertion portion. There was nothing.

  Therefore, in the microball mounting apparatus of the microball dropping method using the array mask, in order to make it easier to drop the microball on the insertion portion of the array mask than in the past, as shown in Patent Document 1, the vibrator is applied to the array mask. There was an example in which (vibration source) was provided. When vibration was applied to the arrangement mask, the fine balls (solder balls 2) were dispersed in the ball cup 4, and the dropping into the insertion portion was smooth.

  However, in the microball mounting apparatus, when the type of the semiconductor wafer that is the object to be mounted is changed, the arrangement of the electrodes on which the conductive microballs are mounted changes, and the diameter of the microballs also changes. Need to be replaced. In such a case, in the conductive ball mounting apparatus as described in Patent Document 1, since the vibrator (vibration source) is directly attached to the array mask, a vibrator is prepared for each array mask. It was necessary to remove and attach the vibrator every time the mask was changed. Furthermore, if the piezoelectric element is simply brought into contact with the array mask as a vibration source, even if tension is applied to the array mask, the array mask has the property of bending, so vibration may not be properly transmitted to the array mask. It was.

Therefore, the present applicant has already proposed a conductive ball mounting apparatus adopting the following means in order to solve the above-mentioned problem as Japanese Patent Application No. 2007-201982 patent application (filed on August 2, 2007). .
1stly, the arrangement | positioning mask in which the insertion part of the electroconductive ball was formed with the predetermined | prescribed arrangement pattern in the mounting area | region, the mask support means which supports an arrangement | positioning mask above a to-be-mounted object, and the vibration means which gives a vibration to an arrangement | positioning mask The conductive ball is dropped into the insertion portion of the array mask by moving a ball cup containing a large number of conductive balls along the upper surface of the array mask during vibration of the array mask by the vibration means. A conductive ball mounting device is mounted on the top.
Secondly, the vibration means includes a vibration source and a contact surface to which the vibration source is connected and a suction port is provided, and the arrangement mask is attracted to the contact surface to contact the vibration of the vibration source. The conductive ball mounting apparatus is characterized in that the conductive ball is transmitted to the array mask through a surface.

  However, like the ball mounting device according to the above patent application, the vibration of the array mask is weak because the vibration of the array mask is poor because the vibration of the array mask is weak only by adsorbing the array mask to the vibrating contact surface. It had become.

Japanese Patent Laid-Open No. 2002-231752

  Therefore, the present invention vibrates the vibration means by vibrating the contact member disposed so as to surround the mounted object by the vibration means and pressing the tensioned arrangement mask against the contact member having a large area. The above-mentioned problem is to be solved by reliably transmitting the signal to the array mask.

In order to solve the above problems, the first invention employs the following means in the microball mounting device.
First, there is provided an array mask in which an insertion portion into which a minute ball is inserted is formed on the ball mounting portion and is disposed above the mounted object, and a vibration means for applying vibration to the array mask.
Secondly, during vibration of the array mask by the vibration means, a device for dropping the microballs into the insertion portion of the array mask by moving a group of microballs along the upper surface of the array mask and mounting it on the mounted object To do.
Third, a contact member disposed so as to surround the mounted object is provided, and the contact member is vibrated by the vibration means.
Fourth, the array mask is vibrated by pressing the tensioned array mask against the contact member.

  According to a second aspect of the present invention, there is provided the microball mounting apparatus according to the first aspect, wherein the contact member has a flat portion on an upper surface, and an array mask is pressed against the flat portion. In the second invention, there is provided tension applying means for pulling the array mask outward on the outside of the contact member, and the array mask pressed against the contact member is pulled slightly below the flat surface. It is a minute ball mounting device to which the pressing to the contact member is added.

  In the first and second aspects of the present invention, the vibration of the vibration means is reliably transmitted to the arrangement mask by pressing the arrangement mask against the contact member having a large area, and the conductive ball is placed on one side of the ball cup. And prevents the conductive ball from dropping into the insertion portion of the array mask by moving the ball cup, and preventing the occurrence of a missing ball and biting of the conductive ball in the gap between the ball cup and the array mask. It became a small ball mounting device that can.

  Although it is an effect of the third invention, since the array mask is pressed against the contact member by slightly pulling it downward by the tension applying means, the vibration from the contact member transmitting the vibration to the array mask is reduced. Not only has the transmission been more reliable, but it has also been possible to apply sufficient tension to the array mask to generate strong vibrations.

Hereinafter, embodiments of the present invention will be described together with examples according to the drawings.
The embodiment relates to a solder ball mounting apparatus. Of course, the present invention can also be used in other microball mounting devices in which conductive microballs are mounted on each electrode formed in a predetermined array pattern on the mounted object.

  The fine balls in the present invention include conductive balls such as solder balls, and the mounted objects include semiconductor wafers (hereinafter simply referred to as wafers), electronic circuit boards, and ceramic substrates. A solder ball 2 is used as a minute ball, and a wafer 1 is used as an object to be mounted. In addition, as the adhesive material, flux, solder paste, conductive adhesive, or the like is used. In the embodiment, flux is used, and the flux is previously applied to the electrode on the wafer on which the solder ball is placed. Has been.

  Usually, the solder ball mounting apparatus has a wafer transfer section for loading, a flux printing section, a ball mounting section, and a wafer transfer section for unloading. However, the micro ball mounting apparatus according to the present invention includes a ball mounting section. It has characteristics. In this ball mounting portion, as shown in the plan explanatory view of FIG. 1, the arrangement mask 3 in which the insertion holes 8 arranged in accordance with the electrode pattern on the wafer 1 are formed, and the solder balls 2 are arranged on the arrangement mask 3. A ball cup 4 to be dropped into the insertion hole 8 and a wafer mounting table 9 capable of moving up and down by sucking and holding the wafer 1 shown in FIG. 2 are provided.

  As shown in FIG. 1, the ball cup 4 is formed with two ball accommodating portions 31 in which a large number of solder balls 2 are accommodated. The ball accommodating portion 31 passes over the through hole forming region 6 of the arrangement mask 3. The ball housing portion 31 has an opening for supplying a ball at the top and an opening for dropping the ball at the bottom.

  The opening on the bottom surface of the ball cup 4 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. A large number of solder balls 2 can be accommodated. The ball cup 4 itself is formed with a width narrower than the width of the array mask 3 as shown in FIG.

  A ball cup moving device that moves the ball cup 4 forward and backward includes a cup holder 32 that applies a moving force in the front-rear direction to the ball cup 4, a Y-axis moving device 23 that moves the cup holder 32, and the cup holder 32. It consists of a guide rail 33 for movement.

  The cup holder 32 is formed with a hollow portion in which the ball cup 4 is disposed, and the ball cup 4 is lightly held in the hollow portion by a weak force such as biasing of the slide roller 34 and the spring 35. , Floats slightly above the array mask 3.

  The Y-axis moving device 23 moves the cup holder 32 holding the ball cup 4 back and forth above the arrangement mask 3 by a ball screw rotated by a driving motor. A holder 32 is attached. The cup holder 32 is movably disposed along the guide rail 33, and the cup holder 32 moves forward and backward along the guide rail 33 by the Y-axis moving device 23.

  The array mask 3 can be attached to the hollow frame 5 around the metal mask 30 which is a mask metal part via a collar 22 which is a stretchable sheet, and can be pulled outward to the corner of the metal mask 30. A holding block member 10 which is a simple protruding member is attached.

  The metal mask 30 is made of a very thin metal such as nickel. The solder ball 2 is inserted into the central through-hole forming region 6, and an insertion hole 8 having a size that can be passed through is formed on the electrode on the upper surface of the wafer 1. It is formed by a predetermined arrangement pattern. A large number of rectangular figures appearing in the center in FIG. 1 show the die size region exaggerated, and a large number of insertion holes 8 exist in the die size region.

  The metal mask 30 and the frame 5 in the embodiment are formed in a quadrangular shape as shown in FIGS. Of course, it is not necessary to have a quadrangular shape, but a polygonal shape is suitable for applying tension. A collar 22 is attached around the rectangular metal mask 30, and the collar 22 is attached to the rectangular frame 5 with tension. Holding block members 10 are attached to the four corners of the metal mask 30. The diagonal holding block members 10 are arranged so as to sandwich the through-hole forming region 6 at the center of the metal mask 30. The metal mask 30 is given tension in the front / rear and left / right directions in FIG. 5 by the flange 22, and tension is given by the holding block member 10 in the diagonal direction outside the corner.

  As shown in FIG. 2, the array mask 3 is supported by the array mask support device so as to be supported above the mounting surface of the solder balls 2 formed on the upper surface of the wafer 1 via an appropriate interval. The array mask support device includes a backup plate 11 which is a contact member disposed so as to surround the wafer 1 placed on the wafer placement table 9, and the backup plate support portion 12 (shown in FIG. 2). In addition, four pulling mechanisms 13 for pulling the holding block member 10 attached to the array mask 3 outward are provided.

  As shown in FIG. 3, the backup plate 11 is made of a plate-like stone material having an opening 14 slightly larger than the wafer 1 in the center, and the upper surface is formed on a flat surface with high planar accuracy. Chamfered portions 11a are formed at four corners corresponding to the positions of the holding block members 10 of the ball array mask 3 which are arranged so as to surround the wafer 1 placed on the table 9 and supported by the array mask support device. Has been. In the embodiment, the backup plate 11 is a single hollow plate in a shape that surrounds the entire periphery of the wafer 1, but does not necessarily have to surround all, and is not a single plate, A divided structure may be used.

  The backup plate 11 has a contact surface 25 that is a flat portion that contacts the arrangement mask 3 on the upper surface, and the contact surface 25 is positioned slightly higher than the mounting surface of the solder balls 2 of the wafer 1. Is supported by the backup plate support 12. In addition, since the backup plate 11 is formed of a stone material instead of a metal material, the rigidity is high, the influence of deformation due to heat can be reduced, and the planar accuracy can be improved compared to the metal material, Processing is also easy, and there is an effect of cost reduction.

  Ultrasonic vibrators 24 serving as vibration sources of the vibration means in the present invention are mounted at four locations on the lower surface of the backup plate 11 in the front, rear, left and right directions of the ball cup 4. The vibration source is not limited to the ultrasonic vibrator 24, and the position and number of vibration sources are not limited, and any vibration source can be used as long as it can impart vibration to the backup plate 11. As shown in FIGS. 3 and 5, two ultrasonic transducers 24 are mounted on the left and right sides of the lower surface of the backup plate 11 in the forward direction at a predetermined interval, and on the lower surface of the backup plate 11 at the rear side in the forward direction. Two are mounted at positions facing the mounted ultrasonic transducer 24.

  The ultrasonic transducer 24 operates the ultrasonic transducer 24 on the rear side of the ball cup 4 in the advancing direction, and is applied to the array mask 3 via a contact surface 25 formed as a flat portion on the upper surface of the backup plate 11. On the other hand, ultrasonic vibration is applied in the traveling direction of the ball cup 4. Of course, the front and rear ultrasonic transducers 24 may be ultrasonically vibrated simultaneously. When the array mask 3 receives the vibration of the ultrasonic vibrator 24, the vibration is transmitted to the solder balls 2 in contact with the array mask 3 to facilitate movement, and the biting is eliminated.

  Note that the vibration frequency and amplitude of the ultrasonic vibrator 24 can be adjusted, and the vibration energy can be adjusted by the electric energy applied to the ultrasonic vibrator 24. It is necessary to adjust the vibration energy according to the diameter of the solder ball 2. Further, the oscillation frequency of the ultrasonic transducer 24 is determined by the diameter of the solder balls 2 and the thickness of the array mask 3.

  As shown in FIGS. 1 and 5, a total of four pulling mechanisms 13 are provided in the vicinity of the four corners of the array mask 3 in the outward direction from the position of the backup plate 11. Of the four corners, one corner serves as a reference position as a hook portion having a holding portion 19 for hooking and holding the holding block member 10 formed on the ball array mask 3, and the other three corner portions. May be a pulling mechanism.

  The pulling mechanism 13 has an arm 18 mounted on an upper portion of a stand 17 fixed to the same frame 16 as the backup plate support 12 so as to be pivotable through a fulcrum 7, and an upper end portion of the arm 18 is a holding block member. 10 is formed as a holding portion 19 that is detachable from the arm 10, and the holding portion 19 is moved slightly downward outside the backup plate 11 by operating an air cylinder 20 connected to the lower side of the arm 18. It is possible. Therefore, the engagement position between the holding portion 19 of the pulling mechanism 13 and the holding block member 10 is set to be substantially the same as or slightly lower than the backup plate 11.

  Next, a procedure for mounting the alignment mask 3 on the alignment mask support apparatus will be described. First, the metal mask 30 in which tension is applied to each side by the flange 22 is placed on the contact surface 25 of the backup plate 11, and the holding block member 10 existing at the corner of the metal mask 30 is pulled by the pulling mechanism. 13 holding parts 19 can be engaged.

  Thereafter, the pulling mechanism 13 serving as the reference position and the air cylinder 20 of the pulling mechanism 13 located at the diagonal position thereof are operated to pull the metal mask 30 in the same direction. At this time, the holding portion 19 of the pulling mechanism 13 moves slightly outward and presses the metal mask 30 against the backup plate 11 in a tensioned state.

  Thereafter, the air cylinder 20 of the pulling mechanism 13 existing at the two remaining corners is operated to apply tension in a direction crossing the previous tension direction, thereby completing the mounting of the array mask 3. As a result, uniform tension acts on the central through-hole forming region 6 of the metal mask 30. In this state, since the holding portion 19 of the pulling mechanism 13 is pulled slightly below the upper surface of the backup plate 11, the metal mask 30 is tightly attached to the backup plate 11 with high planar accuracy due to tension. is there.

  Due to the tension of the pulling mechanism 13 and the flange 22, the portion of the metal mask 30 of the array mask 3 is pressed with a sufficient tension applied to the contact surface 25 formed as a flat portion of the backup plate 11. As well as being easy to transmit, vibrations of appropriate strength can be applied to the array mask 3. Due to this vibration, the solder balls 2 in the ball cup 4 can be smoothly dropped into the insertion holes 8 of the arrangement mask 3.

Plane explanatory drawing of the ball mounting part in the solder ball mounting apparatus concerning a present Example Schematic front explanatory drawing of an array mask support device Exploded perspective view showing relationship between wafer, backup plate and array mask Explanatory drawing which shows the relationship between a ball cup, an arrangement mask, and a vibration source Front explanatory view showing ball cup and array mask Partial enlarged cross-sectional explanatory diagram of array mask

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wafer 2 ... Solder ball 3 ... Arrangement mask 4 ... Ball cup 5 ... Frame 6 ... Through-hole formation area 7 ... Supporting point 8 ... Through-hole 9 ... Wafer mounting table 10: Holding block member 11 ... Backup plate 12 ... Backup plate support 13 ... Pulling mechanism 14 ... Opening 16 ... Frame 17 ... Stand 18・ ・ ・ Arm 19 ・ ・ ・ Holding part 20 ・ ・ ・ Air cylinder 22 ・ ・ ・ 紗 23 ・ ・ ・ Y axis moving device 24 ・ ・ ・ Ultrasonic transducer 25 ・ ・ ・ Contact surface 30 ・ ・ ・ Metal mask 31 ... Ball housing part 32 ... Cup holder 33 ... Guide rail 34 ... Slide roller 35 ... Spring

Claims (3)

An arrangement mask in which an insertion portion into which a micro ball is inserted is formed in the ball mounting portion and is disposed above the mounted object, and a vibration means for applying vibration to the arrangement mask,
In the microball mounting apparatus that drops the microballs into the insertion part of the array mask by moving a group of microballs along the upper surface of the array mask during the vibration of the array mask by the vibration means,
An abutting member disposed so as to surround the mounted object is provided, the abutting member is vibrated by the vibration means, and the array mask is pressed against the abutting member by applying a tension to the abutting member. Micro ball mounting device characterized by vibrating.
2. The microball mounting apparatus according to claim 1, wherein the contact member has a flat portion on an upper surface, and the array mask is pressed against the flat portion.
  Claims wherein tension applying means for pulling the array mask outward is provided outside the contact member, and the array mask pressed against the contact member is pulled slightly below the flat surface to press the array mask against the contact member. Item 3. A microball mounting apparatus according to Item 2.

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