JP2001223236A - Metallic ball transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technique by which a metallic ball is sucked surely onto a suction jig and shifted certainly onto a semiconductor integrated circuit when a ball electrode is formed in the semiconductor integrated circuit and an electronic part such as a BGA(ball-grid-array), to use one suction jig to a plurality of kinds by selectively shifting only a fixed ball electrode, and to provide a means by which a defective is avoided and the ball electrode is transferred only in a non-defective when balls for a plurality of the semiconductor integrated circuits are formed integrally. SOLUTION: A plurality of suction holes 41 with pairs of the electrodes, in which surfaces are covered with a dielectric, are formed to the suction jig 42 installed onto the semiconductor integrated circuit 43, and switch arrays 27 connected to these electrodes and positive and negative voltage sources 28, 29 are mounted. The connection of the switch array 27 is changed over by a microcomputer 30, to which electrode-arrangement information 31 is transmitted, and an electrostatic force repulsive works to a place where the ball electrodes 44 must be shifted, and attractive force to the suction holes to which the ball electrodes need not be shifted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal ball transfer apparatus for transferring a metal ball to an electrode portion by an electrostatic force in a process of manufacturing a semiconductor integrated circuit or an electronic component using the metal ball as an electrode. is there.

[0002]

2. Description of the Related Art In recent years, as electronic devices such as portable communication devices and notebook personal computers have become smaller and more sophisticated, there has been a demand for ever smaller and faster semiconductor integrated circuits. In response to this, instead of lead electrodes that were conventionally arranged around the semiconductor package, BGA (ball grid array) and CSP (chip size chip), in which electrodes are arranged in an area on the surface of a semiconductor integrated circuit. New forms of packaging technology have emerged, such as packaging) and FC (flip chip).

There are various types of electrode forming methods described above. A typical one is to mount a metal ball 2 of eutectic solder or the like on an electrode portion 3 of a semiconductor integrated circuit 1 as shown in FIG. By applying heat, the metal ball 2 and the electrode portion 3
And a final ball electrode 4 is formed. This method has been widely used because it can maintain the diameter and height of the electrode with high precision and is suitable for mass production because a plurality of electrodes can be mounted at once.

In this method, metal balls are arranged in advance in the same arrangement as the electrodes, and are transferred onto a semiconductor integrated circuit. In order to align the metal balls, as shown in FIG. 2, a suction jig 7 having a through hole 5 smaller than the diameter of the metal ball and a mortar-shaped suction hole 6 for aligning the metal balls is provided at the same position as the electrode arrangement. The metal ball 8 is sucked into the suction hole 6 by preparing and sucking air from the through hole 5. Thereafter, the suction jig 7 holding the metal ball 8 is moved onto the electrode of the semiconductor integrated circuit, and the suction of the suction hole 6 is stopped or air is pushed out.
The metal balls 8 sucked in the suction holes 6 are transferred onto the semiconductor integrated circuit. At this time, in order to ensure the transfer of the metal balls 8, as shown in FIG.
Auxiliary means 9 such as pushing out with a pin is used.

[0005]

However, as the size of the ball electrode becomes finer, the weight of the metal ball also becomes lighter, and a phenomenon occurs in which the metal ball does not separate from the suction jig during transfer. The conventional method of pushing out from a suction hole with a pin makes it difficult to process the pin when the metal ball is fine, and is disadvantageous in terms of cost.

Further, there is a problem of the cost of the suction jig itself. A suction jig must be prepared for each type of semiconductor integrated circuit. If the arrangement of the electrodes differs depending on the type, a suction jig corresponding to the arrangement is required, and the manufacturing cost is increased. In order to improve productivity, it is desirable to form electrodes on a plurality of semiconductor integrated circuits at once. However, since there are defective products in the semiconductor integrated circuit, useless metal balls are consumed for the defective products when mounting the metal balls in a lump. As described above, the conventional technology cannot satisfy both the productivity and the production cost.

[0007] The present invention has been made in view of such a state of the prior art, and it is possible to securely adsorb and transfer a metal ball and selectively transfer a metal ball only to necessary electrodes. It is an object of the present invention to provide a metal ball transfer device capable of satisfying both productivity and manufacturing cost.

[0008]

According to the present invention, in order to solve the above-mentioned problems, a suction hole for holding a metal ball which has been sucked is provided, and the inside of the suction hole is covered with a dielectric material. A metal ball transfer device comprising: a suction jig provided with a pair of separated electrodes; switches connected to the respective electrodes; and positive and negative voltage sources connected to the switches. Is provided. According to the present invention, in the above configuration, the suction jig has a plurality of suction holes, and a pair of electrodes whose surfaces are covered with a dielectric are provided inside the suction holes. A metal ball transfer device is provided. Further, according to the present invention, there is provided a metal ball transfer device according to the above configuration, further comprising a switch array including a plurality of switches connected to the respective electrodes of the suction holes. Further, according to the present invention, there is provided a metal ball transfer device according to the above configuration, further comprising control means connected to the switch array and controlling a switching operation of the switch array by external information. You.

The suction jig of the ball transfer device according to the present invention has a suction hole having a mortar shape or the like, and a pair of electrodes covered with a dielectric material are provided on the surface of the suction hole. I do. Each of the pair of electrodes is connected to a positive / negative voltage source via a switch. The metal balls are attracted to the attracting holes by electrostatic force. When the metal ball is transferred onto the semiconductor integrated circuit, the polarity of the positive and negative polarities applied to the pair of electrodes is reversed by switching the connection of the switch. In this case, a repulsive force acts between the electrode and the metal ball, and the metal ball is reliably transferred. When a plurality of suction holes having the above-described basic structure are provided, and a switch array including a plurality of switches connected to respective electrodes of the suction holes is provided, the electrodes provided in the respective suction holes are connected to independent switches. Therefore, the polarity can be switched for each suction hole, and the transfer of the metal ball can be selectively performed.

In the ball transfer device of the present invention, the number of suction holes formed in the suction jig is one to tens of thousands. The shape of the suction hole can be an appropriate shape such as a cylindrical shape in addition to a mortar shape. Various metals such as copper, aluminum, and gold and alloys thereof can be used as a material constituting the electrode formed inside the suction hole. Also, on the surface of these electrodes,
A dielectric is coated to generate an electrostatic force by electrostatic polarization. As a material for the dielectric, various oxide films, nitride films, polyimide, diamond-like carbon, and the like can be used. The thickness of the dielectric is about several μm to several hundred μm,
The selection may be made according to the size and weight of the metal ball. Metal balls to be transferred by the ball transfer device of the present invention,
In addition to solder balls, gold balls, copper balls, non-metal cores coated with metal, and the like can be used.

[0011]

Next, a preferred embodiment of the present invention will be described with reference to FIGS. First, FIG.
(B) shows the basic structure of the suction jig in the ball transfer device of the present invention. The suction jig 10 whose base material is an insulator is provided with a through hole 11 smaller than the diameter of the metal ball 20.
A mortar-shaped depression is provided. Two left and right electrodes 12 and 13 are formed in the depression, and the surfaces thereof are covered with dielectrics 14 and 15. The boundary between the electrode 12 and the electrode 13 is separated and electrically insulated. Two electrodes 1
2 and 13 are connected to positive and negative voltage sources 18 and 19 via switches 16 and 17, respectively.
The polarities of 2 and 13 can be switched by switches 16 and 17.

As shown in FIG. 4A, for example, the suction jig 10 is brought closer to the metal ball 20 with a positive potential applied to one electrode 12 and a negative potential applied to the other electrode 13 of the suction jig 10. Attraction between the metal ball 20 and the electrodes 12 and 13 is caused by an electrostatic force.
Adsorbed in the hollow. At this time, in order to assist the suction by the electrostatic force, the metal ball 20 may be sucked by applying a negative pressure to the through hole 11. Next, the suction jig 10 is moved onto the semiconductor integrated circuit, and as shown in FIG. 4B, the switches 20 and 21 are switched to reverse the polarity of the electrodes. In this state, a repulsive force acts between the metal ball 24 and the electrodes 22 and 23, so that the metal ball 24 is reliably released from the suction jig and is transferred onto the semiconductor integrated circuit. If the assisting by the negative pressure is performed through the through hole during the suction, the application of the negative pressure is stopped at this time.

In order to actually suck the metal ball, as shown in FIG. 5, a suction jig 2 is placed in a container 25 containing the metal ball.
6 is lowered and the suction jig 26
To rise. Alternatively, a jig for absorbing metal balls by air current 2
6, or the metal ball may jump by vibration.

FIG. 6 shows an embodiment of a suction jig having a plurality of suction holes. The electrodes provided in the suction holes 41 are connected to positive and negative voltage sources 28 and 29 via the switch array 27. The switch array 27 is composed of components such as semiconductor relays, and can switch the connection by an external signal. By switching the connection of the switch array 27 so that repulsion acts only on the metal ball at the place where the transfer is desired,
Only predetermined metal balls can be selectively transferred. The switching of the switch array 27 is performed by the microcomputer 30, and if the electrode arrangement information 31 of the semiconductor integrated circuit is input to the microcomputer 30, the metal balls can be selectively transferred only to the desired electrodes.

FIGS. 7A and 7B show an example of a suction jig manufactured so as to be used for a plurality of semiconductor integrated circuits having different electrode arrangements. In FIG. 7A, after the metal ball is sucked into all the suction holes of the suction jig 36, the switch array 33 is switched so that the repulsive force acts only on the suction holes corresponding to the electrode portions of the semiconductor integrated circuit 32. The metal ball in this part is transferred onto the semiconductor integrated circuit by repulsive force, but the metal ball in the other suction hole is not released because the attractive force is still working, and the metal ball is only released to the predetermined electrode part. Can be transferred.

On the other hand, FIG. 7B shows an example in which metal balls are transferred to different types of semiconductor integrated circuits having different electrode arrangements using the same suction jig. The semiconductor integrated circuit 34 of FIG. 7B has the same pitch between the electrodes as the semiconductor integrated circuit 32 of FIG. 7A, but has a different arrangement. Conventionally, in such a case, it is necessary to manufacture two suction jigs corresponding to each kind. However, according to this example, FIG.
Using the same suction jig 37 as the suction jig 36 of
By simply switching the connection of the switch array 35 in accordance with the electrode arrangement of the semiconductor integrated circuit 34, metal balls having different electrode arrangements can be transferred. Of course, the present invention may not be applicable to a product having a different pitch between the ball electrodes. However, since the pitch between the ball electrodes is standardized in the industry, it is necessary to manufacture a suction jig corresponding to each pitch. One suction jig can be used between varieties having the same pitch.

FIG. 8 shows an example in which ball electrodes are collectively formed on a plurality of semiconductor integrated circuits. In this example, metal balls are to be transferred to the two semiconductor integrated circuits 38 and 39, but the semiconductor integrated circuit 38 is a good product and 39 is a defective product. Conventionally, there has been no means for selectively transferring metal balls. In such a case, both good and defective products must be transferred, and wasteful metal balls are consumed for defective products. Was. However, according to this example, the non-defective product 3
By switching the switch array 40 so that a repulsive force acts on the suction holes corresponding to No. 8 and an attractive force acts on the suction holes corresponding to the defective products 39, metal balls can be transferred only to the non-defective products 38 and waste of the ball electrode material can be reduced. Can be prevented.

[0018]

As described above, according to the present invention, since the above-described structure is employed, electrostatic force acts between the suction jig and the metal ball, so that even a minute metal ball can be reliably sucked and transferred. Becomes possible. Further, by switching the electrode potential of the suction jig for each suction hole, a single suction jig can handle a plurality of types of semiconductor integrated circuits. Furthermore, when ball electrodes are formed collectively on a plurality of semiconductor integrated circuits, metal balls can be selectively transferred only to non-defective products, thereby preventing waste of metal balls and achieving both productivity and manufacturing cost. . The present invention uses BGA (ball grid array), C
The present invention can be applied to ball electrodes of semiconductor products such as SP (chip size package), FC (flip chip), and bare chip, as well as electrode formation of various electronic components such as capacitors, resistors and inductors.

[Brief description of the drawings]

FIG. 1 is a process of forming a ball electrode.

FIG. 2 shows a ball alignment method using a conventional suction jig.

FIG. 3 is a conventional method for ensuring ball transfer.

FIG. 4 is a basic structure of a suction jig according to the present invention.

FIG. 5 shows an example of actual ball suction

FIG. 6 shows an embodiment of a suction jig having a plurality of suction holes.

FIG. 7 is an embodiment of a suction jig capable of handling a plurality of types.

FIG. 8 shows an embodiment in which metal balls are transferred only to good semiconductor integrated circuits.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Suction jig 11 Through hole 12, 13 Electrode 14, 15 Dielectric 16, 17 Switch 18 Positive voltage source 19 Negative voltage source 20 Metal ball 27 Switch array 28 Positive voltage source 29 Negative voltage source 30 Microcomputer 31 Electrode arrangement information 41 Suction hole 42 Suction jig 43 Semiconductor integrated circuit 44 Ball electrode

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 3/34 505 H01L 23/12 L F-term (Reference) 3C007 DS07 EW03 FS01 FS06 FU00 LV10 NS08 3F061 AA06 BF04 CA01 CA06 CC00 DB03 DD02 5E319 AC01 BB04 CD26 GG15

Claims (4)

[Claims] A suction jig having a suction hole for holding the sucked metal ball, and a pair of electrodes having a surface covered with a dielectric provided inside the suction hole; A metal ball transfer device, comprising: a switch connected to each of the electrodes; and positive and negative voltage sources respectively connected to the switches. 2. The suction jig has a plurality of suction holes, and a pair of electrodes whose surfaces are covered with a dielectric are provided inside the suction holes, respectively.
2. The metal ball transfer device according to claim 1. 3. The metal ball transfer device according to claim 2, further comprising a switch array including a plurality of switches connected to the respective electrodes of the suction holes. 4. The metal ball transfer device according to claim 3, further comprising control means connected to the switch array and controlling a switching operation of the switch array based on external information.