JP2001135660A - Method and apparatus for ball transfer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transfer just required number of balls to the electrode pads of a wiring board or a semiconductor chip. SOLUTION: The apparatus for transferring balls 6 to electrode pads 71 on a substrate 7 comprises a ball arranging pallet 4 having pits 41 for arranging balls 6 formed at the positions corresponding to the electrode pads 71, a ball suction plate 3 having suction pits 31 corresponding to the arranging pits 41 formed in the ball arranging pallet 4, and a suction head base 2 connected with the ball suction plate 3 and having a suction hole 22 and an evacuation channel 23 for evacuating from the suction pits 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming bumps in a flip chip connection or a ball grid array, and more particularly to a ball transfer apparatus for transferring conductive balls such as solder and gold to semiconductor chips and wiring boards. And a transfer method.

[0002]

2. Description of the Related Art In a method of forming a bump electrode such as a flip chip, a chip size package (CSP), and a ball grid array (BGA) in mounting a semiconductor chip, conductive balls typified by solder balls are arranged. There are ways to do this.

As a method of arranging the balls, a ball is sucked at a position corresponding to an electrode pad of a wiring board or the like by a vacuum at a ball suction plate having a suction hole formed by an etching method, an electroforming method or the like. By releasing the vacuum suction on the wiring board, etc.
A method of arranging and mounting balls on electrode pads to form bumps has been developed and has been put to practical use.

Here, a conventional bump forming method described in Japanese Patent Application Laid-Open No. 7-202401 will be described with reference to FIGS.

[0006] As shown in the ball suction step of FIG. 6, the suction jig 10 is positioned on the ball solder tank 11 (FIG. 6).
(A)).

Thereafter, the screen 12 sucked at the lower end of the suction jig 10 is made to approach the upper surface of the ball solder tank 11 (FIG. 6B).

Next, as shown in the ball mounting step of FIG. 7, a vacuum pressure is applied to each suction hole 13 formed in the screen 12 by a predetermined vacuum pump, so that the ball solder bath 11 Ball solder 14 inside
Is sucked and held in each suction hole 13 (FIG. 7A).

Then, the ball solder 14 is moved upward while being sucked in the suction hole 13, and the printed wiring board 15 is moved.
Then, the suction is released (FIG. 7B).

As a result, the ball solder 14 is mounted on the electrode pad 16 and the formation of the bump is completed (FIG. 7).
(C)).

Further, in another conventional example, a method of forming a bump while vibrating or jumping a ball by vibrating a tank storing the ball has been adopted to more surely attract the ball.

[0011]

In the above prior art (Japanese Patent Laid-Open No. 7-202401), since the suction holes formed in the screen are provided at a predetermined interval, they exist near the suction holes. The ball solder is sucked and sucked into each suction hole.

However, since the ball solder in the ball solder tank is at a random position, it is necessary to suction the ball solder into all the predetermined suction holes even with a strong suction force depending on the existence of the ball solder. Can be difficult.

Further, due to the influence of static electricity, moisture, or the like, a plurality of ball solders may be sucked into one suction hole, or ball solder may adhere to a portion other than a predetermined suction hole.

Therefore, in order to ensure the suction of the ball, a method of vibrating or jumping the ball by vibrating the tank in which the ball is stored is adopted. In this method, the vibrating ball is attached to the suction head. There are disadvantages such as deformation due to collision with the lower surface and other balls, and shaving of the balls due to friction, resulting in a problem that the quality of the formed bumps or completed semiconductor chips or substrates is adversely affected.

Further, as the size and pitch of the suction holes formed in the screen become smaller with the miniaturization of the pattern of the target wiring board or semiconductor chip, the thickness of the metal plate or glass plate used as the screen material is reduced. Need to be thin.

For example, 250 μm suction holes having a diameter of 100 μm are formed.
When formed at a pitch of μm, the plate thickness must usually be 100 μm or less. With such a thin plate thickness, the strength is weakened, and there is a problem that when the ball is sucked, the screen is distorted by the suction force. If the screen is distorted, the suction of the ball may be lost, the pattern size of the suction hole may be deviated, or it may be difficult to form bumps with high accuracy.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to make it possible to transfer a ball to an electrode pad such as a wiring board or a semiconductor chip without excess or deficiency. It is in.

[0018]

According to the present invention, there is provided a ball transfer apparatus for transferring a ball to an electrode pad on a substrate, wherein the ball is aligned at a position corresponding to the electrode pad. A ball alignment pallet having an alignment hole formed therein, a ball suction plate having a through hole corresponding to the alignment hole formed in the ball alignment pallet, and a ball suction plate connected to the ball suction plate. A ball suction base provided with a suction hole and a vacuum suction channel so as to be capable of vacuum suction;

Preferably, the ball alignment pallet is made of a silicon substrate, and the alignment holes are formed by performing one-sided etching by anisotropic etching or isotropic etching.

Further, the ball suction plate is made of a silicon substrate, and the through hole is formed by performing double-sided etching by anisotropic etching or isotropic etching.

The ball suction plate or the ball alignment pallet is made of, for example, metal, glass, ceramic or resin plate.

It is preferable that an alignment hole or a through hole formed in the ball suction plate or the ball alignment pallet is chamfered.

Preferably, a chamber is provided in the middle of the vacuum suction channel of the ball suction base, and the volume of the chamber is variably set.

In this case, the volume of the chamber is variably set by adjusting screws provided on the ball suction base.

Preferably, the ball suction base is provided with vibration generating means for applying vibration to the ball suction base. The vibration applying means is, for example, a piezoelectric element.

Further, according to the present invention, in a ball transfer device for transferring a ball to an electrode pad on a substrate, a first device for aligning the ball at a position corresponding to the electrode pad is provided.
And a ball alignment pallet connected to the ball alignment pallet and provided with a pressure hole so that a desired pressure can be applied to the ball from the first through hole. A pallet mounting table, a ball suction plate in which a second through hole is formed corresponding to the first through hole formed in the ball alignment pallet, and a second through hole connected to the ball suction plate. And a ball suction base provided with a suction hole and a vacuum suction flow passage so as to be capable of vacuum suction from above.

Here, the desired pressure is an exhaust pressure,
The pressure hole is an exhaust hole. Alternatively, the desired pressure may be a drainage pressure, and the pressure hole may be a drainage hole.
In this case, the drainage is, for example, a flux or an adhesive.

According to the present invention, in a ball transfer method for transferring a ball to an electrode pad on a substrate, a ball alignment pallet having an alignment hole for aligning the ball at a position corresponding to the electrode pad is provided. A ball suction plate having a through hole corresponding to the alignment hole formed in the ball alignment pallet; aligning the ball with the alignment hole of the ball alignment pallet; and aligning the ball with the alignment hole of the ball alignment pallet. By aligning the through hole of the suction plate with the ball aligned with the alignment hole of the ball alignment pallet, the ball is sucked into the through hole of the ball suction plate, and the ball suction plate that has absorbed the ball is moved onto the substrate. By aligning the through hole and the electrode pad, and placing the ball adsorbed on the through hole on the electrode pad, To carry out a copy.

Here, it is desirable that the balls aligned in the alignment holes of the ball alignment pallet be sucked and held in the through holes of the ball suction plate by vacuum suction.

In transferring the ball sucked into the through hole of the ball suction plate to the electrode pad of the substrate,
The ball suction plate may be simultaneously transferred and the ball suction plate may be removed after the ball is bonded to the electrode pad.

Further, when transferring the ball sucked in the through hole of the ball suction plate to the electrode pad of the substrate,
Preferably, a wave is generated toward the ball, and the wave assists the removal of the ball from the ball suction plate.

Further, the alignment holes of the ball alignment pallet are through holes, and the balls are aligned by vacuum suction of the balls from the ball suction plate side and by blowing gas or liquid from the through holes of the ball alignment pallet. It is desirable to move the pallet to the ball suction plate.

[0033]

According to the present invention, in a method of transferring conductive balls to electrode pads of a wiring board or a semiconductor chip, a ball alignment pallet having holes formed at positions corresponding to the electrode pads of the wiring board or a semiconductor chip. The conductive balls aligned in advance are suction-held by vacuum suction on a ball suction plate having a through hole formed at a position corresponding to an electrode pad such as a wiring board or a semiconductor chip.

Thus, it is possible to surely adsorb to the ball adsorption plate without excess or shortage. Therefore, the conductive balls can be transferred onto the electrode pads of the wiring board, the semiconductor chip, and the like without excess or shortage.

Further, by forming the ball suction plate by forming a through hole by etching both sides of the silicon substrate, it is possible to form a through hole having high size and high positional accuracy even at a fine pitch.

Further, since the plate thickness can be increased, a plate having high strength can be obtained. Therefore, the conductive balls can be transferred with high accuracy.

[0037]

Next, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) A first embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1A, the balls 6 are aligned with the alignment pits 41 formed on the ball alignment pallet 4. The pattern of the alignment pits 41 is the same as the pattern of the electrode pads 71 of the semiconductor chip 7 shown in FIG.

Next, the suction pits (through holes) 31 formed in the ball suction plate 3 of the suction head 1 are aligned with the alignment pits 41. The suction head 1 includes a suction head base 2 and a ball suction plate 3.

The ball suction plate 3 is made of a silicon substrate. The suction pits 31 having the same pattern as the alignment pits 41 are formed by double-sided etching such as anisotropic etching or isotropic etching. Has become.

The ball alignment pallet 4 is made of a silicon substrate, and the alignment pits 41 are formed by performing one-sided etching by anisotropic etching or isotropic etching.

Here, the ball suction plate 3 or the ball alignment pallet 4 is made of a metal, glass, ceramic or resin plate. The alignment pits 41 or the suction pits 31 formed on the ball suction plate 3 or the ball alignment pallet 4 are chamfered.

Here, the alignment pits 41 or the suction pits 31 formed on the ball suction plate 3 or the ball alignment pallet 4 are formed, for example, in a shape connecting the vertices of a quadrangular pyramid, a shape connecting hemispherical shapes, or a cone. It is a shape that connects vertices.

The suction head base 2 is provided with suction holes 22 having the same pattern as the suction pits 31. By connecting a suction means (not shown) to the suction means connection port 21, the ball 6 can be sucked. It has become. Note that the suction holes 22 do not have to have the same pattern as the suction pits 31 as long as they can be sucked from all the suction pits 31.

Next, as shown in FIG. 1B, the suction head 1 is lowered, and the ball 6 is sucked to the suction pit 31.

Thereafter, the suction head 1 is raised, and FIG.
As shown in (c), the wafer is moved onto the semiconductor chip 7, the suction pit 31 is aligned with the electrode pad 71, the suction head 1 is lowered, the ball 6 is placed on the electrode pad 71, and the transfer is completed. .

At this time, when the ball 6 is solder or the like, the ball suction plate 3 is simultaneously transferred and heated in a reflow furnace or the like to melt the ball 6. After the formation of the bump electrodes, the ball suction plate 3 may be removed.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 2A, the balls 6 are aligned with the alignment pits 41 formed on the ball alignment pallet 4.

Next, in the same manner as in the first embodiment, the balls 6 are sucked on the ball suction pallet 3 of the suction head 1 by vacuum suction.

Next, as shown in FIG. 2B, the suction head 1 is moved above the semiconductor chip 7. Then, the suction pit 31 and the electrode pad 71 are aligned, and the suction head 1 is lowered to transfer the ball 6 to the electrode pad 71.

At this time, the vacuum suction source is stopped shortly before the ball 6 reaches the semiconductor chip 7. When the ball 6 reaches the semiconductor chip 7, the volume of the chamber 24 is adjusted by the adjusting screw 25 so that the suction force enough to maintain the ball 6 is lost.

As a result, the ball 6 is reliably transferred to the semiconductor chip 7. At this time, even when the flux 8 exists on the electrode pad 71 of the semiconductor chip 7, the flux 8
Since there is no suction force for sucking the gas, the flux does not enter the suction pit 31 and the vacuum suction channel 23 of the suction head 1.

(Third Embodiment) A third embodiment of the present invention will be described with reference to FIG.

The ball 6 is sucked to the suction head 1 by the same method as in the first and second embodiments. The suction head 1 is moved over the semiconductor chip 7 and the suction pit 3 is moved.
1 and the electrode pad 71 are aligned, the suction head 1 is lowered, and the ball 6 is transferred to the electrode pad 71. At this time, when the vacuum suction force source is stopped, the vacuum suction flow path 23 is filled with gas, and the piezoelectric element 26 connected to the suction head base 2 is operated, whereby the suction head base 2 is moved.
, Vibration is generated in the gas in the vacuum suction channel 23.

The wave further propagates the gas in the suction holes 22 and the suction pits 31 and reaches the ball 6, whereby the ball 6 is securely separated from the suction pit 31 and transferred to the electrode pad 71.

In this embodiment, a piezoelectric element is used, but any vibrator, ultrasonic vibrator, motor or the like that can apply vibration to the suction head base 2 may be used. Further, although the flux 8 is formed on the electrode pad 71 in FIG. 3, the case where the flux is unnecessary may be omitted.

(Fourth Embodiment) A fourth embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 4A, the balls 6 are aligned in through alignment pits (through holes) 42 formed in the ball alignment pallet 4. The pattern of the penetrating alignment pits 42 is shown in FIG.
This is the same as the pattern of the electrode pad 71 of the semiconductor chip 7 shown in FIG.

An exhaust hole 52 having the same pattern as the through-alignment pits 42 is formed in the ball aligning pallet mounting table 5. By connecting an exhaust means (not shown) to the exhaust means connection port 51, the exhaust pressure is applied to the balls 6. To the ball 6
Can be assisted. The gas to be exhausted is preferably an inert gas such as argon.

The exhaust holes 52 do not have to have the same pattern as the through-alignment pits 42, as long as the exhaust holes 52 can exhaust all of the through-alignment pits 42.

Next, the suction pits 31 formed on the ball suction plate 3 of the suction head 1 and the penetrating alignment pits 42
Align.

Next, as shown in FIG. 4B, the suction head 1 is lowered, and the ball 6 is sucked to the suction pit 31. At this time, exhaust pressure is applied to the ball 6 by an exhaust means (not shown). As a result, the ball 6 is easily detached from the penetrating alignment pit 42.

Thereafter, the suction head 1 is raised, and FIG.
As shown in (c), the wafer is moved onto the semiconductor chip 7, the suction pit 31 is aligned with the electrode pad 71, the suction head 1 is lowered, the ball 6 is placed on the electrode pad 71, and the transfer is completed. .

At this time, similarly to the first embodiment, when the ball 6 is made of solder or the like, the ball suction plate 3 is simultaneously transferred and heated in a reflow furnace or the like in that state.
Is melted and the balls are melted or solidified to form bump electrodes on the electrode pads 71, and then the ball suction plate 3
May be removed.

Although the exhaust pressure is used by the exhaust means in order to make the ball 6 easily detach from the penetrating alignment pit 42, the drain pressure may be used by the drain means. in this case,
A volatile liquid such as ethanol is desirable.

(Fifth Embodiment) Referring to FIG. 5, a fifth embodiment of the present invention will be described.

As shown in FIG. 5A, similarly to the fourth embodiment, the balls 6 are aligned with the through alignment pits (through holes) 42 formed on the ball alignment pallet 4. Drainage holes 52 having the same pattern as the penetrating alignment pits 42 are formed in the ball alignment pallet mounting table 5, and a drainage means (not shown) is connected to the drainage connection port 51 to drain the balls 6. Pressure is applied to assist the ball 6 in detaching. Here, the flux 8 is used as the liquid.

Next, the suction pit 31 formed on the ball suction plate 3 of the suction head 1 and the penetrating alignment pit 42
5B, the suction head 1 is lowered, and the ball 6 is sucked into the suction pit 31 as shown in FIG. 5B.

At this time, a drainage means (not shown)
The discharge pressure of the flux 8 is applied to the ball 6. As a result, the ball 6 is easily separated from the penetrating alignment pit 42, and an appropriate amount of the flux 8 adheres only to the lower portion of the ball 6.

Thereafter, the suction head 1 is raised, and FIG.
As shown in (c), the wafer is moved onto the semiconductor chip 7, the suction pit 31 is aligned with the electrode pad 71, the suction head 1 is lowered, the ball 6 is placed on the electrode pad 71, and the transfer is completed. .

At this time, when the ball 6 is solder or the like, the ball suction plate 3 is simultaneously transferred and heated in a reflow furnace or the like to melt the ball 6, and the ball is melted or solidified and the electrode pad 71 After the formation of the bump electrodes, the ball suction plate 3 may be removed.

According to the fifth embodiment, when the ball 6 is made of lead-tin solder or the like and a flux is required, a process for applying a flux to the electrode pad 71 of the semiconductor chip 7 or the ball 6 is performed. Can be omitted.

Although the description has been given by taking flux as an example of the liquid, an adhesive or the like may be used, and various liquids can be selected according to the application.

[0076]

According to the present invention, in a method of transferring a ball to an electrode pad such as a wiring board or a semiconductor chip,
Holes are formed at positions corresponding to the electrode pads of the wiring board or semiconductor chip. Balls pre-aligned on a ball alignment pallet are formed with through holes at the positions corresponding to the electrode pads of the wiring substrate or semiconductor chip. To the ball suction plate, which is held by vacuum suction.
It is possible to reliably suck the ball onto the ball suction pallet without excess or shortage. Therefore, the balls can be transferred to the electrode pads of the wiring board, the semiconductor chip, and the like without excess or shortage.

In particular, by forming a ball suction plate by forming a through hole by etching a silicon substrate on both sides, a through hole having a high size and a high positional accuracy even at a fine pitch can be formed. Since the thickness can be increased, a pallet having high strength can be obtained. Therefore, the ball can be transferred with high accuracy.

In the case where the holes for positioning the balls of the ball alignment pallet are formed as through holes, a gas or a liquid is blown out from the through holes of the ball alignment pallet when the balls are sucked to the ball suction plate. The ball can be reliably sucked.

Further, when a flux is used as the liquid, the flux can be attached to the ball at the same time as the ball is attracted to the ball attracting plate, so that the process can be simplified.

Further, since only a required amount is attached to the lower surface of the ball, the amount of cleaning residue can be reduced, and the yield is improved.

[Brief description of the drawings]

FIG. 1 is a process chart showing a ball transfer method according to a first embodiment of the present invention.

FIG. 2 is a process chart showing a ball transfer method according to a second embodiment of the present invention.

FIG. 3 is a process chart showing a ball transfer method according to a third embodiment of the present invention.

FIG. 4 is a process chart showing a ball transfer method according to a fourth embodiment of the present invention.

FIG. 5 is a process chart showing a ball transfer method according to a fifth embodiment of the present invention.

FIG. 6 is a process chart showing a conventional ball transfer method (ball suction step).

FIG. 7 is a process chart showing a conventional ball transfer method (ball mounting step).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Suction head 2 Suction head base 21 Suction means connection port 22 Suction hole 23 Vacuum suction channel 24 Chamber 25 Adjusting screw 26 Piezoelectric element 3 Ball suction plate 31 Suction pit 4 Ball alignment pallet 41 Alignment pit 42 Penetration alignment pit 5 Ball alignment Pallet mounting table 51 Exhaust means connection port 52 Exhaust hole 6 Ball 7 Semiconductor chip 71 Electrode pad 8 Flux 10 Suction jig 11 Ball solder tank 12 Screen 13 Suction hole 14 Ball solder 15 Printed wiring board 16 Electrode pad 17 Flux

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naoji Senba 5-7-1 Shiba, Minato-ku, Tokyo Inside NEC Corporation (72) Inventor Yuzo Shimada 5-7-1 Shiba, Minato-ku, Tokyo Japan Inside Electric Company (72) Inventor Takumi Yamamoto 348 Oshima-cho, Hamamatsu-shi, Shizuoka Japan Inside Japan E-M Corporation (72) Inventor Kazuhiko Futami 348 Oshima-cho, Hamamatsu-shi, Shizuoka Japan JM shares Within the company (72) Inventor Akira Hatase 348 Oshima-cho, Hamamatsu-shi, Shizuoka Prefecture Japan E-M Corporation

Claims (21)

[Claims] 1. A ball transfer device for transferring a ball to an electrode pad on a substrate, comprising: a ball alignment pallet having an alignment hole for aligning the ball at a position corresponding to the electrode pad; A ball suction plate having through holes corresponding to the alignment holes formed in the pallet, and a suction hole and a vacuum suction flow path connected to the ball suction plate and capable of vacuum suction from the through holes. A ball transfer device comprising: a ball suction base provided. 2. The ball transfer device according to claim 1, wherein the ball alignment pallet is made of a silicon substrate, and the alignment holes are formed by performing one-sided etching by anisotropic etching or isotropic etching. . 3. The ball transfer device according to claim 1, wherein the ball suction plate is made of a silicon substrate, and the through hole is formed by performing double-sided etching by anisotropic etching or isotropic etching. . 4. The ball transfer device according to claim 1, wherein the ball suction plate or the ball alignment pallet is made of metal. 5. The ball transfer device according to claim 1, wherein the ball suction plate or the ball alignment pallet is made of glass. 6. The ball transfer device according to claim 1, wherein the ball suction plate or the ball alignment pallet is made of ceramic. 7. The ball transfer device according to claim 1, wherein the ball suction plate or the ball alignment pallet is made of a resin plate. 8. An alignment hole or a through hole formed in the ball suction plate or the ball alignment pallet,
2. The ball transfer device according to claim 1, wherein the ball transfer device is chamfered. 9. The ball transfer device according to claim 1, wherein a chamber is provided in the middle of the vacuum suction flow path of the ball suction base, and the volume of the chamber is variably set. 10. The ball transfer device according to claim 9, wherein the volume of the chamber is variably set by an adjusting screw provided on the ball suction base. 11. The ball transfer device according to claim 1, wherein the ball suction base is provided with vibration generating means for applying vibration to the ball suction base. 12. The ball transfer device according to claim 11, wherein said vibration applying means is a piezoelectric element. 13. A ball transfer device for transferring a ball to an electrode pad on a substrate, comprising: a ball alignment pallet having a first through hole for aligning the ball at a position corresponding to the electrode pad; A ball aligning pallet mount connected to the ball aligning pallet and having a pressure hole for applying a desired pressure to the ball from the first through hole; A ball suction plate in which a second through hole is formed corresponding to the first through hole; and a suction hole connected to the ball suction plate, and the suction hole and the vacuum suction so as to be capable of vacuum suction from the second through hole. A ball transfer device comprising: a ball suction base provided with a flow path. 14. The ball transfer device according to claim 13, wherein the desired pressure is an exhaust pressure, and the pressure hole is an exhaust hole. 15. The ball transfer device according to claim 13, wherein the desired pressure is a drainage pressure, and the pressure hole is a drainage hole. 16. The ball transfer device according to claim 15, wherein the drainage liquid is a flux or an adhesive. 17. A ball transfer method for transferring a ball to an electrode pad on a substrate, comprising: a ball alignment pallet having an alignment hole for aligning the ball at a position corresponding to the electrode pad; A ball suction plate having a through hole corresponding to the alignment hole formed in the pallet is prepared. The balls are aligned in the alignment hole of the ball alignment pallet. By aligning the through holes with the through holes of the ball alignment pallet, the balls aligned with the alignment holes of the ball alignment pallet are sucked into the through holes of the ball suction plate, and the ball suction plate on which the balls have been sucked is moved onto the substrate. Align the electrode pad and transfer the ball by placing the ball adsorbed in the through hole on the electrode pad. And a ball transfer method. 18. The ball aligned in the alignment hole of the ball alignment pallet is sucked and held in a through hole of a ball suction plate by vacuum suction.
Ball transfer method. 19. When transferring the ball sucked in the through hole of the ball suction plate to the electrode pad of the substrate, the ball suction plate is simultaneously transferred, and after the ball is bonded to the electrode pad, the ball suction plate is removed. 18. The ball transfer method according to claim 17, wherein: 20. When transferring the ball sucked in the through hole of the ball suction plate to the electrode pad of the substrate, a wave is generated toward the ball, and the wave assists the separation of the ball from the ball suction plate. 18. The method according to claim 17, wherein the transfer is performed. 21. The alignment hole of the ball alignment pallet is a through hole, and the ball is aligned by suctioning the ball from the ball suction plate side and blowing gas or liquid from the through hole of the ball alignment pallet. 18. The ball transfer method according to claim 17, wherein the ball is transferred from a pallet to a ball suction plate.