JP4883508B2 - Conductive ball mounting device - Google Patents

Description

  The present invention relates to an improvement of a conductive ball mounting device, and more specifically, a device for mounting a conductive ball using an array mask in which an insertion hole for inserting a ball is formed corresponding to a mounting position of an object to be mounted. The present invention relates to a conductive ball mounting apparatus in which vibration is applied to an array mask to make it easier to drop a conductive ball onto an insertion portion.

  In a conductive ball mounting apparatus that drops a conductive ball into an insertion portion of an array mask by moving a ball cup containing a large number of conductive balls along the upper surface of the array mask, and mounts it on an object to be mounted. As shown in FIG. 6, the conductive balls (solder balls 1) in the ball cup gather at the rear side in the traveling direction of the ball cup 5 and drop into the insertion portion of the conductive balls (solder balls 1). May not be done smoothly.

  Therefore, in a conductive ball mounting apparatus using a method of dropping conductive balls using an array mask, in order to make it easier to drop the conductive balls to the insertion portion of the array mask than in the past, as shown in Patent Document 1, an array mask is used. There was an example in which a vibrator (vibration source) was provided. When vibration was applied to the array mask, the conductive balls (solder balls 1) were dispersed in the ball cup 5 as shown in FIG. 7, and the dropping into the insertion portion was smooth.

  However, in the conductive ball 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 balls are mounted changes, and the diameter of the conductive balls also changes. Need to be replaced. In such a case, in the conductive ball mounting apparatus as described in Patent Document 1, a vibrator (vibration source) is directly attached to the array mask, so that a vibrator is prepared for each array mask or the array mask. It was necessary to remove and install the vibrator every time it was replaced. 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.

Japanese Patent Laid-Open No. 2002-231752

  The present invention firmly attracts and holds the arrangement mask by the vibration means, and reliably transmits the vibration of the vibration means to the arrangement mask, thereby preventing the conductive balls from collecting on one side in the ball cup, Conductive ball mounting that can prevent the conductive ball from dropping into the insertion part of the array mask by moving the ball cup, and preventing the occurrence of missing balls and biting of the conductive ball in the gap between the ball cup and the array mask An object is to provide an apparatus.

In order to solve the above problems, the first invention employs the following means in the conductive ball mounting apparatus.
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.

  A second invention is the conductive ball mounting device according to the first invention, wherein the contact surface is a contact with a non-mounting area where the insertion portion of the arrangement mask is not formed, In a third aspect of the present invention, in addition to the first aspect or the second aspect, the contact surface is provided so as to surround a mounting region in which an insertion portion of the array mask is formed. The ball mounting device.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the mask support means provides a suction port on a contact surface with the array mask, and the array mask is attached by a suction force from the suction port. This is a conductive ball mounting device to which a limitation is imposed that the contact surface of the mask support means also serves as the contact surface of the vibration means.

  In the present invention, 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 vibration of the vibration source is caused to adhere to the contact surface by adsorbing the array mask. Therefore, the vibration means can firmly hold the arrangement mask and can transmit the vibration of the vibration means to the arrangement mask with certainty. .

  According to the fourth aspect of the invention, the mask support means is provided with a suction port on the contact surface with the array mask, and supports the array mask by the suction force from the suction port. Since the abutment surface also serves as the abutment surface of the vibration means, the number of items attached to the array mask can be reduced, which can help simplify the apparatus.

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 conductive ball mounting apparatuses in which conductive balls are mounted on the respective electrodes formed in a predetermined array pattern on the mounting target. In the present invention, the ball includes a conductive ball such as a solder ball, and the ball mounting object includes a semiconductor wafer (hereinafter simply referred to as a wafer), an electronic circuit substrate, a ceramic substrate, and the like. In this embodiment, a solder ball 1 is used as a ball, and a wafer 2 is used as a ball mounting object.

  Usually, the solder ball mounting device has a carry-in wafer delivery unit, a flux printing unit, a ball mounting unit, and a carry-out wafer delivery unit. However, the conductive ball mounting device according to the present invention includes a ball mounting unit. It has the characteristics. In this ball mounting portion, an arrangement mask 4 in which insertion holes 3 arranged in accordance with the pattern of the electrodes on the wafer 2 are formed, a solder ball supply device, and a wafer mounting that can move up and down by sucking and holding the wafer 2. A table 6 is provided.

  As shown in FIG. 1, the solder ball supply device includes a ball hopper 7 storing a large number of solder balls 1, a ball cup 5 containing a solder ball 1 dropped into the insertion hole 3 of the array mask 4, and a ball cup And a Y-axis moving device 8 for moving 5 in the Y-axis direction. The ball cup 5 moves on the array mask 4 to drop the solder ball 1 into the insertion hole 3 of the array mask 4, and the wafer 2. The solder ball 1 is mounted on the electrode at the upper mounting location. The advancing direction for the ball cup 5 to drop the solder ball 1 into the insertion hole 3 is the vertical direction in FIG. 1 and the front-rear direction in FIG.

  As shown in FIG. 4, the array mask 4 is provided with insertion holes 3 for ball insertion corresponding to the mounting locations of the wafers 2. The insertion holes 3 correspond to a predetermined arrangement pattern of mounting positions formed on the wafer 2. In FIG. 1 and FIG. 5, a large number of rectangular figures appearing in the center are illustrated by exaggerating the die size region 10, and a large number of insertion holes 3 exist in the die size region 10.

  A reference numeral 11 indicated by a dotted line in FIG. 1 is a mounting area where the insertion hole 3 is formed, and the array mask 4 includes a mounting area 11 and a non-mounting area 12 surrounding the mounting area 11. The back surface side of the mounting mask 11 in the mounting area 11 (the side facing the wafer 2) is formed thin as a recess 13 that covers the entire mounting area 11, and the insertion hole 3 is provided in the recess 13. ing. The diameter of the insertion hole 3 of the array mask 4 is slightly larger than the diameter of the solder ball 1.

  The concave portion 13 formed in the mounting region 11 is slightly larger than the outer shape of the wafer 2 as a whole, and the outer peripheral shape of the entire concave portion 13 is formed in a substantially circular shape. When the array mask 4 is attached to the rectangular mask frame 16 with tension, the array mask 4 is pulled in the left-right front-rear direction (up, down, left-right direction in FIGS. 1 and 2), but the outer periphery of the entire recess 13 of the array mask 4 Since the shape is formed in a substantially circular shape, the tension in the left / right / front / rear direction is converted into an average tension in the circular outer direction, and distortion due to the tension hardly occurs.

  The amount of the recess 13 differs depending on the diameter of the solder ball 1 used. In the embodiment, since the solder ball 1 having a thickness of about 100 micrometers is used, the concave portion 13 having a thickness of 20 to 40 micrometers is formed in the array mask 4 having a thickness of 80 micrometers.

  Further, as shown in FIGS. 3 and 5, the concave portion 13 is provided with a convex portion 14 that continues from the non-mounting region 12 on the near side to the non-mounting region 12 on the other side. That is, the convex part 14 is connected to the front and rear edge parts of the concave part 13 in the forming direction. The convex portion 14 is formed at the position corresponding to the dicing line in one direction of the wafer 2 and in the same direction as the moving direction for the ball cup 5 to drop the solder ball 1 into the insertion hole 3. Here, the advancing direction of the ball cup 5 means the front-rear direction in the drawing in FIG. 3, and the up-down direction in the drawing in FIGS. The convex portion 14 is formed of the same material as the arrangement mask 4. By providing the convex portion 14, the strength of the thinned array mask 4 can be increased, and the array mask 4 is difficult to bend. Further, regarding the thickness of the array mask 4, the total thickness of the plate thickness of the mounting region 11 in which the concave portion 13 is formed and the protruding thickness of the convex portion 14 is made thinner than the diameter of the solder ball 1 to be used. Note that the thickness of the array mask 4 may be equal to or greater than the sum of the plate thickness of the mounting region 11 where the recesses 13 are formed and the protrusion thickness of the protrusions 14.

  As shown in FIG. 5, a reinforcing thin plate 22 in which a portion corresponding to the mounting region 11 of the array mask 4 is formed in an empty portion is bonded to the back surface of the array mask 4 in the embodiment. Thereby, the intensity | strength of the arrangement | sequence mask 4 can be improved more and distortion and bending can be suppressed. The reinforcing thin plate 22 is appropriately formed with an opening hole so that bubbles and excess adhesive during bonding can be removed.

  The array mask 4 is affixed to a combination 15 which is a flexible resin sheet, and is attached to a rectangular mask frame 16 by applying tension. The mask frame 16 is a clamp air. The cylinder 17 is fixed to the ball mounting portion constituting frame of the apparatus. There are several fixed points.

  The support device for the array mask 4 corresponding to the mask support means of the present invention includes a mask pressing plate 31 to which an ultrasonic transducer 9 is attached, a mask pressing plate holder 32, and an air cylinder that moves the mask pressing plate 31 up and down. 33 and a suction device (not shown) and the support member 21 of the arrangement mask 4. The support member 21 is disposed below the contact surface 18 of the mask pressing plate 31, and the array mask 4 is placed on the support member 21 with the lower surface of the reinforcing thin plate 22 of the array mask 4 in contact with the upper surface. The upper surface is sucked and held by the mask pressing plate 31. At this time, the array mask 4 is supported by the mask pressing plate 31 in a state where the convex portion 14 formed in the concave portion 13 of the mounting region 11 does not contact the surface of the wafer 2.

  The mask pressing plate 31 is a rectangular frame-shaped body whose center is a rectangular hollow portion having a size corresponding to the mounting region 11 of the array mask 4. The lower surface of the frame of the mask pressing plate 31 is a contact surface 18 to the non-mounting region 12 surrounding the mounting region 11 of the array mask 4 and is formed on a flat surface. A suction groove 19 for sucking the array mask 4 is formed on the contact surface 18. The suction groove 19 serves as a suction port in the present invention. Further, the suction groove 19 is connected to an external suction device (not shown) by a suction pipe 20. The array mask 4 is suction supported by the suction force from the suction groove 19.

  The mask holding plate 31 is held by the vertical air cylinder 33 via mask holding plate holders 32 installed at a plurality of left and right positions, and the hollow portion of the mask holding plate 31 is mounted on the mounting area 11 of the array mask 4. The contact surface 18 of the mask pressing plate 31 is disposed so as to contact the upper surface of the non-mounting region 12 surrounding the entire mounting region 11. The array mask 4 adsorbed and supported on the contact surface 18 of the mask pressing plate 31 is in a state free from distortion at least inside the contact surface 18.

  An ultrasonic vibrator 9 serving as a vibration source of the vibration means in the present invention is attached to the mask holding plates 31 before and after the ball cup 5 in the traveling direction. The vibration source is not limited to the ultrasonic vibrator 9, and any vibration source can be used as long as it can apply vibration to the mask pressing plate 31. As shown in FIGS. 1 and 2, two ultrasonic transducers 9 are mounted on the upper and left sides of the upper surface of the frame member 31 </ b> A of the mask holding plate 31 forward in the traveling direction at a predetermined interval, and the mask in the rearward direction of the traveling direction. Two pieces are mounted on the upper surface of the frame member 31B of the holding plate 31 at positions facing the ultrasonic transducer 9 mounted on the frame member 31A.

  The ultrasonic vibrator 9 operates the ultrasonic vibrator 9 on the rear side in the traveling direction of the ball cup 5, and moves the ball cup 5 against the array mask 4 via the contact surface 18 of the mask holding plate 31. Apply ultrasonic vibrations in the direction of travel. Of course, the front and rear ultrasonic transducers 9 may be ultrasonically vibrated simultaneously. When the array mask 4 receives the vibration of the ultrasonic vibrator 9, the solder balls 1 in the ball cup 5 are kept in a dispersed state as shown in FIG.

  Note that when the electrical energy applied to the ultrasonic vibrator 9 is increased, the vibration energy is also increased. It is necessary to adjust the vibration energy according to the diameter of the solder ball 1. When the diameter of the solder ball 1 is large, the vibration energy is also increased. If the diameter of the solder ball 1 is small and the vibration energy is increased, the solder ball 1 may splash too much in the ball cup 5 and do not fall into the insertion hole 3. Conversely, the diameter of the solder ball 1 is large. If the vibration energy is reduced, the solder ball 1 does not vibrate, and the solder ball lump collected on one side of the ball cup 5 cannot be dispersed.

  Further, the oscillation frequency of the ultrasonic vibrator 9 is determined by the diameter of the solder ball 1 and the thickness of the array mask 4. In the embodiment, a solder ball 1 having a diameter of 100 micrometers uses a frequency of 15 kHz, and a solder ball having a diameter of 200 micrometers uses a frequency of 24 kHz.

  In the embodiment described above, the support device 30 serving as the mask support means is provided with the suction groove 19 serving as a suction port on the contact surface 18 of the mask holding plate 31 which is the main structure with the arrangement mask 4, and the suction groove 19 is suctioned. The arrangement mask 4 is supported by force, and the contact surface 18 of the mask pressing plate 31 also serves as the contact surface of the vibration means, but separately from the contact surface 18 of the mask pressing plate 31. An abutment surface unique to the vibration means can also be formed.

Plane explanatory drawing of the ball mounting part in the solder ball mounting apparatus concerning a present Example Plan view of the main part Front explanatory view showing the relationship between a support device having a ball cup, an array mask, and a vibration source Front view of the main part Exploded perspective view showing the relationship between the contact surface of the mask support means and the array mask Plane explanatory diagram of the solder balls in the ball cup without vibration Plane explanatory diagram of the solder balls in the ball cup with vibration applied

Explanation of symbols

1. . . . . . Solder balls . . . . . Wafer 3. . . . . . Insertion hole 4. . . . . . 4. Array mask . . . . . Ball cup 6. . . . . . 6. Wafer mounting table . . . . . Ball hopper 8. . . . . . Y axis moving device 9. . . . . . Ultrasonic vibrator 10. . . . . Die size area 11. . . . . Mounting area 12. . . . . Non-mounting area 13. . . . . Concave part 14. . . . . Convex part 15. . . . . Combination 16. . . . . Mask frame 17. . . . . Air cylinder for clamping 18. . . . . Contact surface 19. . . . . Adsorption groove 20. . . . . Suction pipe 21. . . . . Support member 22. . . . . Reinforcing sheet 30. . . . . Support device 31. . . . . Mask holding plate 32. . . . . Mask holding plate holder 33. . . . . Air cylinder

Claims (4)

The conductive ball insertion portion includes an arrangement mask formed in a predetermined arrangement pattern in the mounting area, a mask support means for supporting the arrangement mask above the mounted object, and a vibration means for applying vibration to the arrangement mask,
While the array mask is vibrated by the vibration means, the ball cup containing a large number of conductive balls is moved along the upper surface of the array mask to drop the conductive ball into the insertion portion of the array mask and mount it on the mounted object. In the conductive ball mounting device,
The vibration means includes a vibration source and a contact surface connected to the vibration source and provided with a suction port. The arrangement mask is adsorbed to the contact surface to cause vibration of the vibration source through the contact surface. A conductive ball mounting device characterized by transmitting to an array mask.
2. The conductive ball mounting device according to claim 1, wherein the contact surface is in contact with a non-mounting area where the insertion portion of the array mask is not formed.
The conductive ball mounting device according to claim 1, wherein the contact surface is provided so as to surround a mounting region where an insertion portion of an array mask is formed.
  The mask support means is provided with a suction port on the contact surface with the array mask, and supports the array mask by the suction force from the suction port. The contact surface of the mask support means is the contact surface of the vibration means. The conductive ball mounting device according to claim 1, which also serves as a surface.

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