JP3125576B2 - Solder ball bonding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder ball bonding apparatus for bonding a solder ball to be a bump to the surface of a work such as a chip or a substrate.

[0002]

2. Description of the Related Art It is known that solder balls are bonded to the surface of a chip or a substrate, and then the solder balls are heated and melted and solidified to form bumps (protruding electrodes). FIG. 6 is a side view of a main part of a conventional solder ball bonding apparatus. Solder balls 1 as a material of bumps are stored in a container 2. Reference numeral 3 denotes a suction head, which is driven by a lifting / lowering means (not shown) to perform a lifting / lowering operation, thereby vacuum-sucking the solder ball 1 into a suction hole opened on the lower surface thereof, and reciprocating means (not shown) ), And moves horizontally above a work such as the substrate 45 which is clamped and positioned by the clamper 44, and then moves up and down again to move the solder ball 1 to a predetermined position on the substrate. It is designed to be bonded.

Many suction holes are formed in the lower surface of the suction head 3, and the solder balls 1 must be vacuum-sucked in all the suction holes and bonded to the substrate 45. Therefore, conventionally, a camera 7 is installed below the moving path of the suction head 3, and the lower surface of the suction head 3 is observed by the camera 7.
It is determined by image processing whether or not the solder balls 1 are vacuum-sucked in all the suction holes, and if OK, the suction head 3 moves directly above the substrate 45 and moves to the solder ball 1.
Was bonded to the substrate 45.

[0004]

However, in the above-mentioned conventional means, there is a problem that an erroneous determination is likely to occur due to flickering of the image of the camera 7 or noise. Also, in many cases, a large number of solder balls 1 (generally several tens or more) are vacuum-sucked, so that it takes a considerable time to check whether the solder balls 1 are vacuum-sucked in all the suction holes. However, there was a problem that the work efficiency was not improved.

The solder balls 1 picked up by the suction head are not necessarily all transferred to the work, and the solder balls 1 remaining and adhered to the suction holes of the suction head 3 due to a transfer error. However, in this case, the work becomes a defective product in which the solder ball 1 is missing. However, in the past, there was no means for automatically detecting such a transfer error,
Defective workpieces were likely to occur.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned conventional problems and to provide a solder ball bonding apparatus with high operation reliability. More specifically, it is an object of the present invention to provide a solder ball bonding apparatus including means for accurately determining whether a suction head has made a mistake in picking up a solder ball. Another object of the present invention is to provide a solder ball bonding apparatus which can easily determine whether or not all the solder balls picked up by a suction head have been bonded to a work without any transfer error.

[0007]

According to the present invention, an electrode for contacting a solder ball is provided on a moving path of a suction head, and a detecting means for detecting a solder ball by applying a current to the electrode is provided. Things.

[0008]

According to the above arrangement, the suction head picked up by vacuum suction of the solder ball is moved above the electrode, and the solder ball is brought into contact with the electrode to detect whether or not it is conductive by the detecting means. Thus, the presence or absence of a pick-up error can be accurately determined.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a solder ball bonding apparatus according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of a pickup error detection unit provided on a moving path of a suction head of the solder ball bonding apparatus.

In FIG. 1, reference numeral 11 denotes a container as a supply portion for solder balls, in which solder balls 1 are stored.
Reference numeral 12 denotes a base, which elastically supports the container 11 so as to be able to swing from the side and the lower side. Reference numeral 14 denotes a vibrator such as a piezoelectric element as an ultrasonic vibration means, which is mounted on the lower surface of the container 11. When a high-frequency voltage is applied, the vibrator 14 ultrasonically vibrates, the container 11 also ultrasonically vibrates, and the solder balls 1 stored therein are fluidized.
By adjusting the magnitude of the high frequency voltage, the container 1
(1) The magnitude of the ultrasonic vibration can be adjusted.

Reference numeral 15 denotes a solder ball supply device which supplies the solder balls 1 to the container 11 through a pipe 16.
The container 11 is provided with a sensor for detecting the remaining amount of the solder ball 1 such as an optical sensor 47, and supplies the solder ball 1 when it is detected that the remaining amount of the solder ball 1 in the container 11 is low. I do. Reference numeral 17 denotes a base of the supply device 15.

On the lower surface of the suction head 3, a large number of suction holes 4 of the solder ball 1 are formed in a matrix shape (see also FIG. 2). The suction head 3 includes a support shaft 18, a tube 19
The vacuum ball 20 is connected to the vacuum device 20 via vacuum and the like. When the vacuum device 20 is driven, the solder ball 1 is vacuum-sucked into the suction hole 4 and the vacuum suction state is released.
53 is a valve for opening and closing the suction path of the tube 19, and 55 is a pressure sensor for detecting a vacuum pressure.

Reference numeral 21 denotes a holding block for the suction head 3, and the support shaft 18 of the suction head 3 is held by the holding block 21. Reference numeral 22 denotes a movable block, and two guide rails 23 are vertically arranged on the front surface thereof.
The holding block 21 is mounted on the guide rail 23 so as to be able to move up and down. Nut 2 on the side of holding block 21
4 and the nut 24 has a vertical feed screw 2
5 is screwed. When the feed screw 25 is rotated by being driven by a motor 26 provided in the movable block 22, the holding block 21 and the suction head 3 perform an elevating operation. That is, the nut 24, the feed screw 25, and the motor 26 are lifting means for causing the suction head 3 to perform a lifting operation.

Reference numeral 30 denotes a movable table, and the movable block 22 is mounted on the movable table 30 so as to be slidable in the horizontal direction. A motor 31 is attached to the side of the moving table 30. When the motor 31 is driven, a feed screw 32 built in the moving table 30 rotates, and the movable block 22 moves sideways along the feed screw 32. Reciprocate. That is, the moving table 30 serves as a reciprocating means for moving the suction head 3.

Reference numeral 40 denotes a positioning portion,
The X table 42 and the Y table 43 are stacked. A clamper 44 is provided on the Y table 43, and positions the substrate 45 by clamping the substrate 45 from left and right. The suction head 3 is moved by the moving table 30 to the container 1.
1 and the positioning part 40 reciprocate. A pickup error detection unit 70 is provided on the movement path of the suction head 3 between the container 11 and the positioning section 40 of the substrate 45. 69 is the mounting table. Next, the structure will be described with reference to FIG.

Reference numeral 71 denotes an insulating base plate on which electrodes 72 are arranged in parallel. These electrodes 72 are juxtaposed at positions corresponding to the suction holes 4 of the suction head 3. Each electrode 72 has a contact 73a, 73b, 73
c, 73d. 74 is each contact 73a-7
This is a rotary movable contact that comes in contact with 3d, and contacts each of the contacts 73a to 73d in order by rotating in the direction of the arrow.

The movable contact 74 is connected to a power supply 75 and a detector 76. Further, a fixed terminal 77 is connected to the detector 76, and when the suction head 3 moves down, the fixed terminal 77 contacts the bottom surface of the suction head 3. The suction head 3 is formed by using a conductive metal or by using an insulating material and coating the surface with a conductive film. When the suction head 3 moves above the pickup error detection unit 70 and descends there, the solder ball 1 lands on and contacts the electrode 72, and the lower surface of the suction head 3 also contacts the fixed terminal 77. Then, the movable contact 74 is rotated in the direction of the arrow to make each of the contacts 73a to 73a.
73d, the solder balls 1 and the electrodes 72
Is generated, and a current is detected by the detector 76. In addition, if there is no solder ball 1, no current flows, so it can be seen that the solder ball 1 has been picked up incorrectly. Such judgment is made by computer (not shown)
It is performed by

This solder ball bonding apparatus is constructed as described above. Next, the overall operation will be described.
In FIG. 1, when the motor 26 rotates forward, the suction head 3 descends toward the container 11. At that time, the vibrator 14
Is driven, the container 11 is ultrasonically vibrated, and the solder balls 1 stored therein are flowing. Then, when the suction head 3 is lowered, the solder ball 1 is vacuum-sucked in the suction hole 4. Next, the suction head 3 is raised by the reverse rotation of the motor 26, and the solder ball 1 is picked up.

Next, in FIG. 1, when the motor 31 rotates forward, the suction head 3 moves above the pickup error detecting unit 70 and stops there. Then, when the motor 26 rotates forward again, the suction head 3 descends, and the solder ball 1 vacuum-adsorbed on its lower surface lands on each electrode 72 as shown in FIG. Then, the movable contact 74 is rotated in the direction of the arrow, and whether or not a current flows is detected by the detector 76, and it is determined whether or not there is a pickup error.

If all currents are detected, it is determined that there is no pick-up error, and then the suction head 3 moves above the substrate 45 by the forward rotation of the motor 31. Then, when the motor 26 rotates forward, the suction head 3 descends and mounts the solder ball 1 on the upper surface of the substrate 45. Next, the vacuum suction state by the vacuum device 20 is released, the suction head 3 is lifted, and the motor 31 rotates in the reverse direction, so that the suction head 3 returns to above the container 11. A flux is previously applied to the upper surface of the substrate 45 by means not shown, and the solder ball 1 is bonded to the substrate 45 by the adhesive force of the flux. If there is a pick-up error, the operator may be notified by a buzzer or other notifying means, or the suction head 3 may be moved upward above the container 11 and then moved up and down again to perform soldering. The ball 1 may be vacuum-sucked, and various means for the recovery operation can be considered.

By repeating the above operation, the solder balls 1 are successively bonded to the upper surface of the substrate 45. The bonded solder ball 1 is heated and melted in a later step to form a bump.

FIG. 3 is a cross-sectional view of a pickup error detecting unit provided on a moving path of a suction head of a solder ball bonding apparatus according to a second embodiment of the present invention. The pickup error detection unit 80 is installed on the mounting table 69 similarly to the pickup error detection unit 70, and is configured by arranging electrodes 82 on an insulating base plate 81 side by side. . Adjacent electrodes 82 are lead portions 8
3 are connected. The suction head 3 is formed of an insulating material.
Is provided by coating or the like. Reference numeral 85 denotes a terminal that contacts the lead portion 83, reference numeral 86 denotes a terminal that contacts the conductive portion 84, and the terminals 85 and 86 are in contact with the power supply 75 and the detector 76. Other configurations are the same as in the first embodiment.

Therefore, when the suction head 3 stops above the pickup error detecting unit 80 and descends there, the solder ball 1 lands on each electrode 82 as shown in the figure, and a series circuit is generated. If the solder balls 1 are vacuum-sucked in all the suction holes 4, the circuit is closed and a current flows to the detector 76. Solder ball 1 is 1
If there is no pick-up error, the circuit remains open and no current flows to the detector 76.
Therefore, the presence or absence of a pick-up error can be accurately determined.

FIG. 4 is a plan view of a transfer error detecting unit provided on a moving path of a suction head of a solder ball bonding apparatus according to a third embodiment of the present invention, and FIG. 5 is a side view of the same. The transfer error detection unit 90 is similar to the pickup error detection units 70 and 80, and
9. This transfer error detection unit 90
After the transfer operation, it is determined whether or not all (16 in this embodiment) solder balls 1 picked up by the suction head 3 by vacuum suction have been transferred to the substrate 45 without any transfer error. Things.

Reference numeral 91 denotes an insulating base plate, and a large number of electrodes 92 (16 in this embodiment) are formed on the upper surface thereof in pairs.
Pairs) are juxtaposed. These electrodes 92 are arranged in a matrix at positions corresponding to the suction holes 4 of the suction head 3. In a third embodiment of the invention, four columns A, B,
C, D, and a parallel circuit shown in FIG. 4 is configured for each of the columns A, B, C, and D. Further, switches 93a, 93b, 93c, 93d are provided which are connected to and separated from one terminal a, b, c, d of each of the columns A, B, C, D. Each of the switches 93a to 93d is connected to the detector 76. Have been. The other terminals of the columns A, B, C, and D are connected to a power supply 75.

Next, the operation will be described. In FIG. 1, a suction head 3 picks up a solder ball 1 by vacuum suction.
Is moved above the substrate 45, and then moved up and down again to transfer the solder balls 1 to the substrate 45 for bonding. In this case, all the solder balls 1
Is not always transferred from the substrate 45 to the substrate 45, and sometimes remains while being attached to the suction head 3. Then, the board 45 becomes a defective product in which the solder ball 1 is partially missing.

Therefore, in the third embodiment of the present invention, after the suction head 3 performs the transfer operation of the solder ball 1 to the substrate 45, the motor 31 rotates in the reverse direction and the suction head 3
The suction head 3 is stopped above the transfer error detecting unit 90 during the return to the position above. Then, the suction head 3 is lowered by rotating the motor 26 forward. FIG. 5 shows the state at this time. In this example, one solder ball 1 is adhered to and remains on the suction head 3 (see also the solder ball 1 shown by a chain line in FIG. 4). Therefore, in FIG. 4, if the switches 93a to 93d are opened and closed in order, the column C
2 is conducting, a current is detected by the detector 76,
It turns out that there was a transfer error.

There are various possible recovery operations when it is determined that a transfer error has occurred. That is, first,
The suction head 3 is moved again above the substrate 45, and the suction head 3 is moved up and down there, so that the solder balls 1 are transferred to the substrate 45 again. In this case, air may be sent from the vacuum device 20 to the suction head 3 and the solder ball 1 may be pressed against the substrate 45 by the air pressure.
Switching of the air flow of the vacuum device 20 is as follows.
It can be easily performed by a well-known mechanism.

Secondly, when it is determined that there is a transfer error, the operation of the apparatus is stopped, and the operator is notified of this by a notification means such as a buzzer. Therefore, the worker removes the solder ball 1 remaining on the suction head 3 with tweezers or the like, and transfers the solder ball 1 to the missing portion of the substrate 45. There are various possible recovery operations when a transfer error occurs.

[0030]

As described above, according to the present invention, it is determined whether or not the suction head has made a mistake in picking up the solder balls and whether or not all the picked up solder balls have been transferred to a work such as a substrate. Can be accurately and accurately determined. In addition, it is possible to appropriately perform recovery when a pickup error or a transfer error occurs, and thus a highly reliable solder ball bonding apparatus can be realized.

[Brief description of the drawings]

FIG. 1 is a side view of a solder ball bonding apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a pickup error detection unit provided on a moving path of a suction head of the solder ball bonding apparatus according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of a pickup error detection unit provided on a moving path of a suction head of a solder ball bonding apparatus according to a second embodiment of the present invention.

FIG. 4 is a plan view of a transfer error detecting unit provided on a moving path of a suction head of a solder ball bonding apparatus according to a third embodiment of the present invention.

FIG. 5 is a side view of a transfer error detecting unit provided on a moving path of a suction head of a solder ball bonding apparatus according to a third embodiment of the present invention.

FIG. 6 is a side view of a main part of a conventional solder ball bonding apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solder ball 2 Container (supply part) 3 Suction head 4 Suction hole 70, 80 Pickup mistake detection unit 72, 82, 92 Electrode 76 Detector 90 Transfer misdetection unit

Claims (1)

(57) [Claims] A suction head for vacuum-sucking the solder ball into a plurality of suction holes formed in a lower surface of the solder ball; a lifting means for causing the suction head to perform a lifting operation; And a reciprocating means for reciprocating the suction head between the supply section and the positioning section. A bonding apparatus for a solder ball, comprising: A solder ball bonding apparatus comprising: an electrode for contacting the solder ball; and a detecting means for detecting a solder ball by applying a current to the electrode.