JP2010258141A - Flux transfer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate sliding resistance and bias force to a transfer pin by air-floating the transfer pin, in an inner hole portion for hanging support of the transfer pin, to reduce load on land, when transferring to only the empty weight of the transfer pin, and to improve positional accuracy of the centering of the transfer pin. <P>SOLUTION: First, a transfer device is equipped with a lifting means for making the transfer pin and a material to be transferred relatively closer, and is used for transferring flux by making the tip of the transfer pin abut against the transfer part of the material to be transferred. Second, the transfer pin is equipped with an expanded section formed by the expansion of the outer periphery. Third, a support member for hanging support of the transfer pin is provided by forming an inner hole, to make the transfer pin pass through upward and downward and by joining the expanded section of the transfer pin and the inner hole so that they mate together. Fourth, an air passage that provides an opening to the inner hole, and a means for supplying a gas to the air passage are equipped. Fifth, flux is transferred by supplying gas to a gap between the transfer pin being passed through and the inner hole for generating a lifting force to the transfer pin. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an improvement of a flux transfer apparatus used in an apparatus in which a solder ball or the like is mounted on an object to be transferred such as a wafer. Specifically, a transfer pin that attaches a flux to the tip and an elevating unit that relatively moves the transfer pin and the transfer object relatively close to each other, and transfers the flux by bringing the tip of the transfer pin into contact with the transfer portion of the transfer object. The present invention relates to an improvement of a flux transfer apparatus.

  In the flux transfer technology used to form bumps on a transfer object such as a wafer, in the conventional pin transfer method, the pin tip diameter of the transfer pin becomes smaller as the ball diameter of the mounted solder ball or the like becomes smaller. End up. As a result, the load per unit area of the transfer portion with which the transfer pin tip abuts increases, and there is a problem that the land surface of the transfer object such as a wafer is scratched, such as an impression. In particular, the problem becomes prominent when there is warping or distortion of the transferred object such as a wafer.

  In order to solve the above problem, as shown in Patent Document 1, a transfer pin support member is provided at the lower end portion of the flux transfer head, and the transfer pin is slid downwardly by a spring in a slide hole of the transfer pin support member. A possible supporting technique is disclosed. However, in this disclosed technique, the transfer load increases due to the biasing force and weight of the spring. Further, since the sliding hole is used as a guide for the transfer pin, the sliding resistance is added to the weight of the transfer pin, and the transfer load is increased. It became large and was insufficient to solve the above problem. Further, when the size of the inner diameter of the sliding hole with respect to the outer diameter of the transfer pin is increased so as to reduce the sliding resistance, the centripetal accuracy of the transfer pin is lowered, so that there is a problem that an accuracy error increases.

Japanese Patent No. 4016202

  A first object of the present invention is an inner hole portion (a portion corresponding to a sliding hole of a conventional transfer pin) for suspending and supporting the transfer pin, and the transfer pin is applied to the transfer pin by air floating. In addition to eliminating sliding resistance, the weight of the spring and the urging force are eliminated, and the load applied to the land by the transfer pin during transfer is limited to the weight of the transfer pin. The second purpose is to increase the inner diameter of the sliding hole relative to the outer diameter of the transfer pin so as to reduce the sliding resistance. Although the centripetal accuracy is reduced and the accuracy error is increased, the present invention is to provide a flux transfer device that facilitates centering of the transfer pin and increases the positional accuracy of the transfer pin. .

The first invention employs the following means in order to solve the above problems.
First, a transfer pin that attaches a flux to the tip, and an elevating means that relatively moves the transfer pin and the transferred material up and down, and the flux is obtained by bringing the tip of the transfer pin into contact with the transfer site of the transferred material A flux transfer device for transferring
Secondly, the transfer pin includes an enlarged diameter portion whose outer periphery is enlarged.
Third, an inner hole for allowing the transfer pin to float up and down is formed, and a support member that suspends and supports the transfer pin by engaging the enlarged diameter portion of the transfer pin around the upper opening of the inner hole. Prepare.

4thly, it has the ventilation path opened to the said inner hole, and the gas supply means which supplies gas to this ventilation path.
Fifth, a gas is supplied to the clearance between the loosened transfer pin and the inner hole to generate a floating force on the transfer pin, and in this state, the tip of the transfer pin is brought into contact with the transfer portion of the transfer object to obtain a flux. The flux transfer device is characterized by transferring the heat flux.

  A second invention is a flux transfer apparatus obtained by adding detection means for detecting a vertical movement position of the transfer pin relative to the support member to the first invention.

  According to the present invention, since the load applied during the transfer of the flux is reduced only by the weight of the transfer pin, there is no risk of imprinting on the transfer object such as a wafer at the end of the transfer pin. Further, when the size of the inner diameter of the sliding hole with respect to the outer diameter of the transfer pin is increased so as to reduce the sliding resistance, the centripetal accuracy of the transfer pin is lowered and the accuracy error is increased. The centering of the pin is facilitated, and the positional accuracy of the transfer pin is increased. In addition, since the load applied during transfer is reduced only by the weight of the transfer pin, the inertia load of the transfer pin can be reduced. Flux transfer was possible without any indentation, leading to tact improvement.

Front explanatory drawing which shows the outline of the solder ball mounting apparatus in which this invention is used Left cross-sectional explanatory diagram showing the relationship between the support member of the flux transfer device and the transfer pin Front sectional explanatory view showing the relationship between the transfer pin and the displacement meter in the support member before transfer Front sectional explanatory view showing the relationship between the transfer pin in the support member and the displacement meter during transfer

Hereinafter, embodiments of the present invention will be described together with examples according to the drawings.
FIG. 1 is a schematic front view showing an example of a solder ball mounting apparatus 1 in which the present invention is used. In the embodiment, the wafer 3 is used as the transfer object in the present invention, and the flux transfer apparatus according to the present invention is used in the solder ball mounting apparatus 1 for mounting the solder balls 2 on the wafer 3.

  As shown in FIG. 1, the solder ball mounting apparatus 1 includes a solder ball mounting head 4 that holds the solder ball 2 by suction and mounts it on the wafer 3, a flux transfer head 6 that transfers the flux 5 onto the wafer 3, and a solder ball. A solder ball supply unit 7 for supplying the solder ball 2 to the mounting head 4, a flux supply unit 8 for supplying the flux 5 to the flux transfer head 6, and the wafer 3 for suction and support for transferring the flux 5 and mounting the solder ball 2. Stage 9, a lateral movement device 10 for the flux transfer head 6 and the solder ball mounting head 4, an elevating mechanism 11 for the stage 9, and a longitudinal movement mechanism 12.

  The solder ball mounting head 4 and the flux transfer head 6 are attached to a first lateral moving body 13 and a second lateral moving body 14 that can move and stop independently as shown in FIG. The solder ball mounting head 4 and the flux transfer head 6 are moved in the left-right direction (lateral direction) in FIG. 1 and stopped at the necessary positions, and the operations of flux transfer and solder ball mounting are performed.

  A wafer recognition camera 15 is attached to the first lateral moving body 13 to which the solder ball mounting head 4 is attached. The wafer recognition camera 15 is connected to a control unit 19 provided in the solder ball mounting apparatus 1 via a cable 23. Connected.

  The flux transfer head 6 attached to the second lateral moving body 14 has a transfer pin 20, a support member 22 that supports the transfer pin 20, and a support member 22 that is attached to the transfer pin 20. A displacement meter 18 is provided for recognizing the amount pushed up from the previous flying height by touching (push-up amount). The displacement meter 18 is located immediately above the transfer pin 20 and detects the vertical movement position of the transfer pin 20 relative to the support member 22 from the displacement of the distance from the transfer pin 20. The amount of push-up is recognized. The displacement meter 18 is also connected to a control unit 19 provided in the solder ball mounting device 1 via a cable 23.

  As shown in FIG. 2, the transfer pin 20 has a tip 24 for attaching the flux 5 to the lower end, and the outer periphery of the upper end is enlarged larger than an inner hole 21 of a support member 22 to be described later. There is an enlarged diameter portion 25 that can be engaged around the portion. The transfer pin 20 is suspended and supported by engaging the enlarged diameter portion 25 around the upper opening of the inner hole 21. The transfer pin 20 penetrates in the vertical direction of the inner hole 21. The transfer pin 20 is configured to transfer the flux 5 to the land 16 by bringing the tip 24 into contact with the land 16 which is a transfer portion of the wafer 3 as a transfer object.

  The support member 22 attached to the second laterally moving body 14 is formed with an inner hole 21 having a size that allows the transfer pin 20 to be engaged by the enlarged diameter portion 25 and to be loosened. The air passage 26 for supplying the gas that floats the transfer pin 20 from the surrounding four sides is opened toward the transfer pin 20 attached thereto. The air passage 26 is connected to a gas supply unit 27 provided in the solder ball mounting apparatus 1 through a gas supply passage 28.

  The gas sent out from the gas supply unit 27 passes through the gas supply path 28, passes through the gas passage 26 opened in the inner hole 21, and enters the clearance between the inner hole 21 and the transfer pin 20 from the four sides of the inner hole 21. As shown in FIG. 3, the enlarged diameter portion 25 is pushed up and the transfer pin 20 is floated.

  The stage 9 has an elevating mechanism 11 and a forward / backward moving mechanism 12. The elevating mechanism 11 serves as elevating means for relatively moving the transfer pins 20 and the wafer 3 to be transferred close together in the present invention. Of course, as means for relatively approaching, means for lowering the transfer pin 20 may be used, or means for raising and lowering both the transfer pin 20 and the stage 9 may be used.

  Hereinafter, the ball mounting operation in the present embodiment will be described. First, the wafer 3 is positioned on the stage 9. Thereafter, the stage 9 is moved to a set position below the first horizontal moving body 13 by the back-and-forth moving mechanism 12 of the stage 9, and the wafer recognition camera 15 is moved on the stage 9 by moving the first horizontal moving body 13. The wafer recognition camera 15 is moved laterally, and the wafer recognition camera 15 is positioned above the land 16 of the wafer 3 to be mounted with the solder ball, and the position of the land 16 is recognized.

  At this time, the stage 9 is at a reference height, and the tip of the transfer pin 20 of the flux transfer head 6 and the tip of the suction nozzle 17 of the solder ball mounting head 4 are at a predetermined height with respect to the surface of the stage 9. is there. Further, the transfer pin 20 is centered at the center position of the inner hole 21 by the supply of gas (air), and is at a floating height.

  The transfer pin 20 is positioned above the flux supply unit 8 by moving the back-and-forth movement mechanism 12 and the second lateral movement body 14. At this time, the suction nozzle 17 of the solder ball mounting head 4 is retracted (laterally moved) by the first laterally moving body 13 so as not to interfere with the stage 9 when the stage 9 is raised.

  Subsequently, the stage 9 is lifted by a set amount by the elevating mechanism 11, the transfer pin 20 is brought into contact with the flux supply unit 8, and the flux 5 is attached to the tip 24 of the transfer pin 20, and then the stage 9 is moved to a reference height. To lower.

  The transfer pin 20 is positioned above the flux transfer portion of the land 16 recognized by the wafer recognition camera 15. The alignment is performed by the back-and-forth moving mechanism 12 and the second laterally moving body 14 of the stage 9. Thereafter, the stage 9 is raised by a set amount by the elevating mechanism 11. This increase amount is a relative approach amount between the transfer pin 20 and the stage 9 and is caused by the rise of the stage 9 in the embodiment, but may be performed by the transfer pin 20 being lowered, It may be performed by both lowering of the transfer pin 20. When the stage 9 is raised, the tip 24 of the transfer pin 20 is brought into contact with the transfer site, the flux 5 is transferred, and the post-transfer stage 9 is lowered to the reference height.

  At this time, when the transfer pin 20 contacts, the displacement (push-up amount) shown in FIG. 4 is recognized by the displacement meter 18 from the flying height of the transfer pin 20 shown in FIG. The reference height of the stage 9 to the suction nozzle 17 when the ball is mounted this time is based on a value obtained by removing the push-up amount from the set amount of the stage 9 raised when the pin 20 is brought into contact with the transfer site. The amount of increase from is required. The amount of increase from the reference height is also a relative approach amount. This relative approach is caused by the rise of the stage 9 in the embodiment, but may be performed by the lowering of the suction nozzle 17. Alternatively, both the raising of the stage 9 and the lowering of the suction nozzle 17 may be performed.

  In this way, the flux transfer height detecting means is used as means for detecting the height of the transfer pin 20 detected by the displacement meter 18, and instead of the tog attached to the transfer pin 20 (member described in Patent Document 1). Since the transfer pin 20 is directly detected, only the weight of the transfer pin 20 is obtained, and because of its light weight, the transfer speed and acceleration / deceleration can be increased, leading to a tact-up.

  Subsequently, the suction nozzle 17 is positioned above the solder ball supply unit 7 by moving the back-and-forth movement mechanism 12 and the first lateral movement body 13. At this time, the transfer pin 20 of the flux transfer head 6 is retracted (laterally moved) by the second laterally moving body 14 so as not to interfere with the stage 9 when the stage 9 is raised.

  Thereafter, the stage 9 is raised by a set amount by the lifting mechanism 11, the suction nozzle 17 of the solder ball mounting head 4 is brought close to the solder ball supply unit 7, and the solder ball 2 is sucked by the suction nozzle 17, and then the stage 9 is moved. Lower to the reference height. Accordingly, as with the alignment at the time of flux transfer, the front and rear moving mechanism 12 and the first laterally moving body 13 are attracted above the ball mounting portion (same as the flux transfer portion) of the land 16 recognized by the wafer recognition camera 15. The nozzle 17 is aligned.

  The stage 9 is lifted by the lift amount of the stage 9 (the lift amount of the stage 9 described by reference numeral 0025) determined from the lift amount from the flying height of the transfer pin 20, and the solder ball 2 is moved from the suction nozzle 17 to the land 16. To be installed. After the mounting, the suction of the suction nozzle 17 is released, and the stage 9 is lowered to the reference height, thereby completing the ball mounting operation.

DESCRIPTION OF SYMBOLS 1 ... Solder ball mounting apparatus 2 ... Solder ball 3 ... Wafer 4 ... Solder ball mounting head 5 ... Flux 6 ... Flux transfer head 7 ... Solder ball supply part 8 ...・ Flux supply unit 9... Stage 10 .. lateral movement device 11... Lifting mechanism 12 .. back and forth movement mechanism 13... First lateral movement body 14. Wafer recognition camera 16 ... Land 17 ... Suction nozzle 18 ... Displacement meter 19 ... Control unit 20 ... Transfer pin 21 ... Inner hole 22 ... Support member 23 ... Cable 24 ... tip part 25 ... expanded diameter part 26 ... vent path 27 ... gas supply part 28 ... gas supply path

Claims (2)

Flux that includes a transfer pin that attaches a flux to the tip, and an elevating means that relatively moves the transfer pin and the transferred object closer to each other, and transfers the flux by bringing the tip of the transfer pin into contact with the transfer site of the transferred object In the transfer device,
The transfer pin has an enlarged diameter part whose outer periphery is enlarged,
An inner hole is formed to allow the transfer pin to float up and down, and a support member that suspends and supports the transfer pin by engaging an enlarged diameter portion of the transfer pin around the upper opening of the inner hole;
An air passage opening in the inner hole;
Gas supply means for supplying gas to the vent passage,
A gas is supplied to the clearance between the loosened transfer pin and the inner hole to generate a floating force on the transfer pin, and in this state, the tip of the transfer pin is brought into contact with the transfer portion of the transfer object to transfer the flux. A featured flux transfer device. 2. The flux transfer apparatus according to claim 1, further comprising detection means for detecting a vertical movement position of the transfer pin with respect to the support member.

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