JPH07307344A - Bonding equipment for solder balls - Google Patents

Abstract

PURPOSE:To provide a bonding equipment which can stick a suitable amount of flux on solder balls and realize continuous operation without troubles, in bonding equipment of solder balls which vacuum-sucks the solder balls to a suction head, the solder balls on a board or a ship, and forms solder bumps. CONSTITUTION:Solder balls 1 stored in a vessel are vacuum-sucked by a suction head 3 and moved to a board. In the course of movement, the solder balls 1 are dipped in flux stored in the main body 72 of a storing part, by moving the suction head 3 up and down. After a suitable amount of flux is stuck on the solder balls 1, the suction head 3 is moved to above the board, and the solder balls 1 are bonded to the board. Solder balls 1a dropped from the suction head 3 to the storing part are pushed into falling holes by a squeegee 75.

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 solder balls to be bumps 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 to melt and solidify to form bumps (protruding electrodes). FIG. 6 is a schematic side view of a conventional solder ball bonding apparatus. 1 is a solder ball and is a container 2
It is stored in. Reference numeral 3 denotes a suction head, which is vertically moved to perform vacuum suction of the solder ball 1 in the container 2 into a suction hole formed in the lower surface of the solder ball 1 and clamped by a clamper 44 of a positioning portion to position the substrate. Then, the solder ball 1 is bonded to the substrate 45 by moving above 45 and performing the raising / lowering operation again there. The suction head 3
When the solder ball 1 is moved up and down by vacuum suction to pick up the solder ball 1, the solder ball 1 is made to flow by blowing nitrogen gas or dry air into the container 2 by means not shown, and the suction head 3 is moved by the suction head 3. To facilitate vacuum adsorption.

[0003]

By the way, prior to bonding the solder balls 1 to the substrate 45 as described above, the surface of the substrate 45 is provided so that the solder balls 1 can be satisfactorily soldered to the substrate 45. Flux is applied in advance by a transfer pin or the like. However, if the substrate 45 is warped, the flux is not uniformly applied, and as a result,
There is a problem that defective soldering of the solder balls 1 is likely to occur.

Therefore, an object of the present invention is to provide a solder ball bonding apparatus capable of favorably soldering all solder balls to a work such as a substrate or a chip with an appropriate amount of flux.

[0005]

To this end, according to the present invention, the solder ball storage portion, the workpiece positioning portion, and the solder balls stored in the storage portion are vacuum-sucked to the lower surface and positioned on the positioning portion. A suction head for bonding to a work, a reciprocating means for reciprocating the suction head between a reservoir and a positioning section, a lifting means for lifting and lowering the suction head, and a reciprocating path are provided in the middle of the reciprocating path. The solder ball bonding device is composed of the flux storage tank. Further, a main body in which a drop hole is formed in the bottom surface and flux is stored, a squeegee that reciprocates on the bottom surface to drop the solder balls remaining on the bottom surface into the drop hole, The squeegee is configured to reciprocate.

[0006]

According to the above construction, the suction head vacuum-sucking the solder balls provided in the storage section moves above the flux storage section, and ascends and descends there to store the solder balls in the main body. The solder balls are bonded to the work by immersing the flux in the flux to adhere the flux, and then moving the work to the upper side and performing the elevating operation again. Further, when the suction head moves up and down on the flux storage portion to attach the flux to the solder balls, the solder balls may drop from the suction head onto the bottom surface of the main body. Therefore, by reciprocating the squeegee, the solder balls on the bottom surface are dropped into the falling holes so that the subsequent operation of attaching the flux to the solder balls is not hindered.

[0007]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a side view of a solder ball bonding apparatus according to an embodiment of the present invention, and FIGS. 2A and 2B are cross-sectional views of a pickup head of the solder ball bonding apparatus during operation, 3 is a perspective view of a flux reservoir provided in the solder ball bonding apparatus, FIG. 4 is a sectional view of the same, and FIG. 5 is a block diagram of the solder ball bonding apparatus.

In FIG. 1, reference numeral 11 denotes a container as a storage portion for the solder balls, in which the solder balls 1 are stored.
Reference numeral 12 denotes a base, which elastically supports the container 11 so as to be swingable from both sides and from below. 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. The vibrator 14 ultrasonically vibrates when a high-frequency voltage is applied, and the container 11 also ultrasonically vibrates, and the solder balls 1 stored therein are fluidized. By adjusting the magnitude of this high frequency voltage, the magnitude of ultrasonic vibration of the container 11 can be adjusted.

Reference numeral 15 denotes a solder ball supply device, which supplies the solder ball 1 to the container 11 through a pipe 16.
The container 11 is provided with a solder ball 1 remaining amount detection sensor (described later) 47 such as an optical sensor, and when it is detected that the solder ball 1 remaining amount in the container 11 is low, the solder ball 1 is detected. Supply 1. Reference numeral 17 is a base of the supply device 15.

On the lower surface of the suction head 3, a large number of suction holes 4 (see FIG. 2) of the solder balls 1 are formed in a matrisk shape. The suction head 3 is connected to a vacuum device 20 via a support shaft 18, a tube 19 and the like. When the vacuum device 20 is driven, the solder ball 1 is vacuum-sucked in the suction hole 4 and the vacuum suction state is maintained. To release. 5
3 is a valve provided on the tube 19 for opening and closing the suction passage,
Reference numeral 55 is a pressure sensor that detects the magnitude of the suction pressure.

Reference numeral 21 is a holding block of 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 of the movable block.
The holding block 21 is mounted on the guide rail 23 so as to be vertically movable. The nut 2 is provided on the side of the holding block 21.
4 and the nut 24 has a vertical feed screw 2
5 is screwed in. When the feed screw 25 is rotated by being driven by the motor 26 provided in the movable block 22, the holding block 21 and the suction head 3 move up and down. That is, the nut 24, the feed screw 25, and the motor 26 serve as an elevating unit that causes the suction head 3 to perform an elevating operation.

Reference numeral 30 denotes a moving table, and the movable block 22 is mounted on the moving table 30 slidably in the lateral direction. A motor 31 is attached to a side portion of the moving table 30, and when the motor 31 is driven, a feed screw 32 incorporated in the moving table 30 rotates, and the movable block 22 moves laterally along the feed screw 32. Move back and forth. That is, the moving table 30 serves as a means for reciprocating the suction head 3.

Numeral 40 is a positioning portion, and a base 41 and
The X table 42 and the Y table 43 are stacked. A clamper 44 is provided on the Y table 43, and the substrate 45 is clamped from the left and right to be positioned. The suction head 3 is moved by the moving table 30 into the container 1
It reciprocates between 1 and the positioning unit 40.

Reference numeral 70 denotes a flux reservoir provided in the middle of the reciprocating path of the adsorption head 3, and the detailed structure thereof will be described with reference to FIGS. 3 and 4. The storage unit 70 is mainly composed of a container-shaped main body 72.
A flux 71 is stored inside the. Body 72
The bottom surface 73 is flat, and the falling holes 7 are provided on both sides.
4 is formed in a groove shape.

A squeegee 75 is provided inside the main body 72. The squeegee 75 is held by the rod 77 of the cylinder 76, and when the rod 77 projects, the squeegee 7
5 horizontally moves leftward on the bottom surface 73, and when the rod 77 retracts, 5 horizontally moves rightward. That is, the cylinder 76
Is a drive means for horizontally reciprocating the squeegee 75. The lower end of the squeegee 75 is located at a position slightly higher than the bottom surface 73 as shown in FIG. 4, and reciprocates to smooth the liquid surface of the flux 71. In addition, the solder balls dropped from the suction head 3 onto the bottom surface 73 (see FIG.
In, the solder ball indicated by reference numeral 1 a) is dropped into the drop hole 74. As shown in FIG. 4, the drop holes 74 are formed on both sides of the bottom surface 73 avoiding the lowered position of the suction head 3.

In FIG. 4, a camera 79 is mounted on the side wall of the main body 72. The side wall of the main body 72 is transparent, and the camera 79 detects the liquid level of the flux 71. When the liquid level falls to a predetermined level, the flux 71 is replenished to the main body 72 by a replenishing means such as a dispenser (not shown). Further, the main body 72 has a pipe 8
1 is connected, and when the valve 82 provided in the middle of the pipe 81 is opened, the flux 71 is discharged and the liquid level is lowered.

In FIG. 2A, reference numeral 46 is a lead wire connected to the vibrator 14, and a high frequency voltage is applied to the vibrator 14 through the lead wire 46. Further, a remaining amount detecting sensor 47 including an optical sensor is provided on the side surface of the container 11. The container 11 is transparent, and the remaining amount detection sensor 47 detects the level of the solder balls 1, that is, the remaining amount of the solder balls 1. When the remaining amount of the solder balls 1 becomes small, the solder balls 1 are supplied from the supply device 15 to the container 11 as described above. 48 is an optical sensor 4
Reference numeral 7 is a connected detection circuit.

In FIG. 5, reference numeral 53 denotes the vacuum device 20.
The valve 54 is provided in the suction path of the valve, and 54 is a valve drive circuit. By opening and closing the valve 53, the suction head 3 vacuum-sucks the solder ball 1 and releases the vacuum suction state.

Reference numeral 55 is a pressure sensor for detecting the vacuum suction force of the vacuum device 20, 56 is a detection circuit thereof, 57 is a motor drive circuit for driving the motor 26, 58 is a vibrator drive circuit for driving the vibrator 14, and 59 is a drive circuit. A motor drive circuit for controlling the drive of the motor 31, 60 is a supply device drive circuit for controlling the drive of the supply device 15, 64 is a cylinder drive circuit, 6
5 is a valve drive circuit. The above circuits are connected to a control unit (CPU) 62 via an interface 61. The control unit 62 controls each circuit while reading the program data and the like stored in the memory 63.

The solder ball bonding apparatus is constructed as described above, and the overall operation will be described below.
In FIG. 1, when the motor 26 rotates normally, the suction head 3 descends toward the container 11. In FIG. 2 (a),
When the oscillator 14 is driven, the container 11 vibrates ultrasonically, and the solder balls 1 stored therein flow. Then, the suction head 3 descends (see the suction head 3 shown by the chain line in the figure), so that the solder ball 1 is inserted into the suction hole 4.
Are vacuum-adsorbed. Next, when the motor 26 rotates in the reverse direction, the suction head 3 rises and the solder ball 1 is picked up.

Next, in FIG. 1, when the motor 31 rotates in the forward direction, the adsorption head 3 is moved to the flux reservoir 70.
Move above. Therefore, in FIG. 4, the suction head 3 descends when the motor 26 rotates in the forward direction, and the descending stops when the solder ball 1 lands on the bottom surface 73 of the main body 71 (see the solder ball 1 indicated by the broken line). The motor 26 rotates in the reverse direction and the suction head 3 moves up. The liquid level of the flux 71 is adjusted in advance so that the solder ball 1 is immersed to an appropriate depth, and the squeegee 75
The liquid surface is smoothed by appropriately performing the reciprocating motion, and therefore, by performing the above-described raising / lowering motion, an appropriate amount of flux 71 is attached to the surface of the solder ball 1.

In FIG. 1, the suction head 3 moves above the substrate 45 by the forward rotation of the motor 31.
Then, the motor 26 rotates in the forward direction, and the suction head 3 descends to mount 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 rises, and the motor 31 rotates in the reverse direction, whereby the suction head 3 returns to above the container 11.
The solder ball 1 is attached to the substrate 4 by the adhesive force of the flux 71.
Bonded to 5. By repeating the above operation, the solder balls 1 are bonded to the upper surface of the substrate 45 one after another. The bonded solder ball 1 is
In a subsequent process, the bumps are heated and melted to form bumps.

By the way, in FIG. 4, when the suction head 3 moves up and down to attach the flux 71 to the solder ball 1, the solder ball 1 vacuum-sucked by the suction head 3
May fall off the suction head 3 and fall on the bottom surface 73 (see the solder ball indicated by reference numeral 1a in FIG. 4). This solder ball 1a becomes an obstacle when the suction head 3 descends to attach the flux 71 to the solder ball 1 after the next time. Therefore, after the suction head 3 is lifted, the cylinder 76 is operated to reciprocate the squeegee 75, and the solder ball 1a is dropped into the drop hole 74 so as not to hinder the subsequent operation. That is, the squeegee 75 also serves as a means for smoothing the liquid surface of the flux 71 and a means for dropping the solder ball 1 into the drop hole 74.

If the diameter of the solder ball 1 changes due to a change in the type of the substrate 45, the flux 71
The immersion depth of the solder ball 1 can be adjusted by adjusting the liquid surface level of. Further, when the diameter of the solder ball 1 is reduced by changing the kind of the solder ball 1 to lower the liquid level, or when the flux 71 is to be discharged to replace the flux 71, a valve 82 in FIG.
And the flux 71 is discharged from the main body 72. The work may be a chip, and the present invention can be modified in various ways. Further, the storage section is not limited to the container 11, and may be a storage section in which solder balls are arranged in a plane and stored.

[0025]

As described above, according to the present invention, it is possible to bond a proper amount of flux to a solder ball and bond it to a work such as a substrate or a chip. In addition, since the solder balls that have fallen to the bottom of the main body can be removed to the drop holes by the squeegee, continuous operation can be performed for a long time without trouble.

[Brief description of drawings]

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

2A is a sectional view of the pickup head of the solder ball bonding apparatus of the embodiment of the present invention during operation. FIG. 2B is a solder ball bonding apparatus of the embodiment of the present invention. Sectional view of the picked-up suction head during operation

FIG. 3 is a perspective view of a flux reservoir provided in a solder ball bonding apparatus according to an embodiment of the present invention.

FIG. 4 is a sectional view of a flux reservoir provided in a solder ball bonding apparatus according to an embodiment of the present invention.

FIG. 5 is a configuration block diagram of a solder ball bonding apparatus according to an embodiment of the present invention.

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

[Explanation of symbols]

 1 Solder Ball 3 Adsorption Head 11 Container (Solder Ball Reservoir) 24 Nut 25 Feed Screw 26 Motor 30 Moving Table 40 Positioning Part 45 Board 70 Flux Reservoir 71 Flux 72 Main Body 73 Bottom 74 Drop Hole 75 Squeegee 76 Cylinder (Drive) means)

Claims (1)

[Claims] 1. A solder ball storage part, a work positioning part, a suction head for vacuum-sucking a solder ball stored in the storage part to a lower surface thereof, and bonding the work ball positioned on the positioning part to the work. Reciprocating means for reciprocating the suction head between the storage section and the positioning section; elevating means for raising and lowering the suction head;
A flux accumulating portion provided in the middle of the reciprocating path, the accumulating portion having a drop hole formed on the bottom surface and a flux accumulating portion, and a reciprocating operation on the bottom surface to move the bottom surface. A solder ball bonding apparatus comprising: a squeegee for dropping the solder ball remaining on the drop hole into the drop hole; and a drive means for reciprocating the squeegee.