JP3301330B2 - 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 serving as a bump to a 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). In addition, as a conventional solder ball bonding apparatus, the suction head is moved up and down above the solder ball storage portion, the solder ball is vacuum-sucked into the suction hole on the lower surface thereof, and then the suction head is picked up. The flux is moved above the storage part, and the lifting operation is performed again to attach the flux to the lower surface of the solder ball. Then, the suction head is moved above a work such as a substrate or a chip, where the lifting operation is performed. In addition, there is known a device in which a solder ball is mounted on a work.

[0003] In the above operation, when the suction head moves up and down above the flux storage portion to attach the flux to the lower surface of the solder ball, the solder ball may fall from the suction hole into the flux storage portion. . When the solder balls fall into the flux storage portion in this manner, the solder balls hinder the subsequent work of attaching the flux.

Therefore, the present applicant has previously proposed means for solving such a problem (Japanese Patent Laid-Open No. 7-307344). In this device, a drop hole is formed in the bottom surface of the main body for storing the flux, and when the squeegee is reciprocated to smooth the liquid surface of the flux, the solder ball dropped on the bottom surface is dropped into the drop hole. Things.

FIGS. 8 (a), 8 (b), 8 (c), 8 (d)
FIG. 4 is an explanatory view of a flux attaching operation in the conventional solder ball bonding apparatus. As shown in FIG. 8A, a drop hole 3 is formed on the bottom surface of the main body 2 in which the flux 1 is stored. Reference numerals 5 and 6 denote a pair of left and right squeegees. One of the squeegees 5 or 6 is made to land on the liquid surface of the flux 1 and is moved in the horizontal direction, thereby smoothing the liquid surface of the flux 1. Adjust the depth. The suction head 7 vacuum-adsorbs a plurality of solder balls 8 into suction holes on the lower surface in a previous step.
In FIGS. 8B to 8D, one squeegee 5 is omitted.

Next, the operation will be described. As shown in FIG. 8 (a), the flux 1 is attached to the lower surface of the solder ball 8 by moving the suction head 7 up and down above the main body 2. In this case, the solder ball 8 Due to the viscosity, it may fall from the suction hole to the bottom surface of the main body 2. 8a is a dropped solder ball.

After the suction head 7 performs the operation of attaching the flux 1 to the solder balls 8, the suction head 7 moves above the work (not shown). During that time, as shown in FIG. 6 is moved rightward on the bottom surface of the main body 2 to smooth the liquid level of the flux 1. At this time, the solder ball 8a that has fallen on the bottom surface is pushed by the squeegee 6 and falls into the drop hole 3.

[0008]

According to the above-mentioned conventional method, when the solder ball 8 is small, the solder ball 8 can be surely dropped into the drop hole 3. However, when the solder ball 8 is large, the solder ball 8 cannot quickly sink into the drop hole 3, and its top a is pushed by the lower end of the squeegee 6 moving to the right at a considerably high speed. (See FIG. 8 (c)), it was easily pushed onto the bottom surface without falling into the drop hole 3 and easily mixed into the flux 1 (FIG. 8 (d)). If the solder balls 8a remain on the bottom surface and mix into the flux 1 in this manner, the solder balls 8a will hinder the subsequent work of attaching the flux.

Accordingly, the present invention provides a solder ball bonding apparatus provided with a flux storage portion capable of reliably dropping a solder ball dropped on the bottom surface of a main body into a drop hole formed on the bottom surface of the main body. The purpose is to do.

[0010]

SUMMARY OF THE INVENTION The present invention is a drop hole formed in the bottom surface of the main body of the reservoir of the flux, of the bottom surface
Form shallow and deep portions in order of increasing distance from the center , and shallow
Is smaller than the diameter of the solder ball, and the depth of the deep part is
This is larger than the diameter of the solder ball .

[0011]

According to the present invention having the above-described structure, a large-sized solder ball can be reliably sunk down to the deepest portion of a drop hole when the squeegee moves forward.

An embodiment of the present invention will be described below 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. FIGS. 2, 3, 4, 5, 6, and 7 are explanatory views of the flux attaching operation in the solder ball bonding apparatus, and show a series of operations in order.

First, the overall structure of a solder ball bonding apparatus will be described with reference to FIG. In FIG. 1, 1
Reference numeral 1 denotes a container as a storage portion for solder balls, in which solder balls 8 are stored. Reference numeral 12 denotes a base, which elastically supports the container 11 by means of an elastic support portion 13 so as to be swingable from both sides and from below. Reference numeral 14 denotes a vibrator made of a piezoelectric element as an ultrasonic vibrating 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 8 stored therein flow or jump.

A supply unit 15 supplies the solder balls 8 to the container 11 through a pipe 16. The container 11 is provided with a sensor (not shown) for detecting the remaining amount of the solder ball 8 such as an optical sensor.
When it is detected that the remaining amount of the solder balls 8 in the inside is small, the solder balls 8 are supplied to the container 11. Reference numeral 17 denotes a base of the supply unit 15.

A solder ball 8 is provided on the lower surface of the suction head 10.
Many suction holes (not shown) are formed in a matrix shape. The suction head 10 includes a support shaft 18, a tube 19
The vacuum ball 20 is connected to the vacuum device 20 via vacuum or the like. When the vacuum device 20 is driven, the solder ball 8 is vacuum-sucked into the suction hole and the vacuum suction state is released. 5
3 is a suction passage opening / closing valve provided in the tube 19;
A pressure sensor 55 detects the magnitude of the suction pressure.

Reference numeral 21 denotes a holding block for the suction head 10, and the support shaft 18 of the suction head 10
It is held at 1. A movable block 22 has two guide rails 23 vertically disposed on the front surface thereof, and the holding block 21 is mounted on the guide rail 23 so as to be able to move up and down. A nut 24 is provided on the side of the holding block 21, and a vertical feed screw 25 is screwed into the nut 24. When the feed screw 25 rotates by being driven by the motor 26 provided in the movable block 22,
The nut 24 moves up and down along the feed screw 25, and the holding block 21 and the suction head 10 perform an elevating operation. That is, the nut 24, the feed screw 25, and the motor 26
It is an elevating means for performing the elevating operation at 0.

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 10.

Numeral 40 designates a positioning unit, which is an X table 4
1, a Y table 42 and a substrate holder 43 are stacked. A clamper 44 is provided on the substrate holder 43, and clamps and positions a substrate 45 as a work from left and right. The suction head 10 reciprocates between the container 11 and the positioning unit 40 by the moving table 30.

Reference numeral 70 denotes a flux storage portion provided in the reciprocating path of the suction head 10, and its detailed structure will be described below with reference to FIG. The storage unit 70
The main body 72 has a container shape, and the flux 1 is stored inside the main body 72. The bottom surface 73 of the main body 72
Is flat, and one side thereof is a liquid reservoir 74 of the flux 71 having a deep bottom. A drop hole 75 is formed in the other side. The drop hole 75 has a shallow portion 75a and a deep portion 75b. The depth of the shallow portion 75a is smaller than the diameter of the large solder ball 8, and the depth of the deep portion 75b is larger than the diameter of the large solder ball 8. The shallow portion 75a and the deep portion 75b are arranged so as to become deeper in order from the center of the bottom surface 73. 7
Reference numerals 6 and 77 denote a pair of left and right squeegees which move up and down by means not shown and reciprocate horizontally along a bottom surface 73 of the main body 72.

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 10 descends toward the container 11. At this time, vibrator 1
When the container 4 is driven, the container 11 is ultrasonically vibrated, and the solder balls 8 stored in the container 11 are flowing or jumping.

Then, when the suction head 10 is lowered, the solder balls 8 are vacuum-sucked into the suction holes. Next, the suction head 10 is raised by the reverse rotation of the motor 26, and the solder ball 8 is picked up. Meanwhile, FIG.
As shown in FIG. 3, one squeegee 76 descends to the liquid level of the flux 71, and then the squeegee 76 moves to the left as shown in FIG. Is smoothed and developed. And FIG.
, The suction head 10 moves above the flux storage unit 70 by the forward rotation of the motor 31.
Then, as shown in FIG. 4, when the motor 26 rotates forward, the suction head 10 descends and the solder balls 8 land on the flux 71.

Next, the motor 26 rotates in the reverse direction, and the suction head 10 moves up (FIG. 5). The liquid level of the flux 71 is adjusted in advance by the squeegee 76 so that the solder ball 8 is immersed to an appropriate depth. Therefore, by performing the above-described raising and lowering operation, the surface of the solder ball 8 has an appropriate amount of flux. 71 adheres.

In FIG. 1, the suction head 10 is moved above the substrate 45 by the forward rotation of the motor 31. The suction head 10 is lowered by the forward rotation of the motor 26, and the solder balls 8 are moved. It is mounted on the upper surface of the substrate 45. Next, the vacuum suction state by the vacuum device 20 is released, the suction head 10 is lifted, and the motor 31 rotates in the reverse direction, so that the suction head 10 returns above the container 11. The solder balls 8 are bonded to the substrate 45 by the adhesive force of the flux 71. By repeating the above operation, the solder balls 8 are successively bonded to the upper surface of the substrate 45. The bonded solder ball 8 is heated and melted in a later step to form a bump.

4 and 5, when the suction head 10 moves up and down to attach the flux 1 to the solder balls 8, the solder balls 8 vacuum-adsorbed to the suction heads 10 fall from the suction heads 10. May fall on the bottom surface 73 (see a solder ball indicated by reference numeral 8a in FIG. 5). As described above, the solder ball 8a becomes an obstacle when the suction head 10 moves down and causes the flux 71 to adhere to the solder ball 8 from the next time onward.

Then, after the suction head 10 is raised, one squeegee 76 is raised and the other squeegee 77 is lowered, and the lower end of the squeegee 77 is attached to the bottom surface 73 of the main body 72 as shown in FIGS. Move to the right while landing. Then, the solder ball 8a becomes the squeegee 7
7 first falls into the shallow portion 75a of the drop hole 75 (FIG. 6), and then its top a is
Is pushed to the right in the shallow portion 75a and falls into the deep portion 75b (FIG. 7).

[0026]

According to the present invention, when the suction head is moved up and down to attach the flux to the lower surface of the solder ball, the large solder ball that has fallen to the bottom of the main body of the flux storage part is squeegeeed. Can be removed to a deeper drop hole, so that continuous operation can be performed for a long time without any trouble.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram of a flux attaching operation in a solder ball bonding apparatus according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a flux attaching operation in the solder ball bonding apparatus according to one embodiment of the present invention.

FIG. 4 is an explanatory diagram of a flux attaching operation in the solder ball bonding apparatus according to one embodiment of the present invention;

FIG. 5 is an explanatory diagram of a flux attaching operation in the solder ball bonding apparatus according to one embodiment of the present invention.

FIG. 6 is an explanatory diagram of a flux attaching operation in the solder ball bonding apparatus according to one embodiment of the present invention.

FIG. 7 is an explanatory diagram of a flux attaching operation in the solder ball bonding apparatus according to one embodiment of the present invention.

FIG. 8 is an explanatory view of a flux attaching operation in a conventional solder ball bonding apparatus.

[Explanation of symbols]

 Reference Signs List 8 solder ball 10 suction head 11 container (soldering portion of solder ball) 70 flux storing portion 71 flux 72 main body 73 bottom surface 75 drop hole 75a shallow portion 75b deep portion 76, 77 squeegee

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/60

Claims (1)

(57) [Claims] And a suction head for vacuum-sucking the solder balls stored in the storage portion to a lower surface thereof and bonding the solder balls stored in the storage portion to the work positioned in the positioning portion. Reciprocating means for reciprocating the suction head between the storage part and the positioning part, elevating means for performing an elevating operation on the suction head,
A flux storage portion provided in the middle of the reciprocating path, wherein the storage portion has a drop hole formed in the bottom surface, and a main body in which the flux is stored; A squeegee for dropping the solder balls remaining on the squeegee into the drop hole, and driving means for reciprocating the squeegee .
The shallow part and the deep part are formed in order of increasing distance , and the depth of the shallow part is
It is smaller than the diameter of the solder ball, and the depth of the
A solder ball bonding apparatus characterized in that the diameter is larger than the diameter of the solder ball.