JPH0719798B2 - Arrangement method of fine metal balls - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a TAB (Tape Automated Bonding) method, which is one of the methods of connecting an electrode of an IC chip and an external lead,
The present invention relates to a method of arranging fine metal balls (hereinafter also referred to as bumps) according to a predetermined arrangement pattern.

[Conventional technology]

In the TAB method, the lead wiring to the electrode part of the IC chip is connected to the tip part of the lead formed by patterning on the TAB tape and the electrode part of the IC chip via a metal projection for bonding called a bump. Is a method of joining. The bump is TA
The tape is attached to either the lead side of the B tape or the electrode side of the IC chip, and the TAB tape and the IC chip are joined by heating and pressing with a bonding machine.

The method of forming bumps on the lead side of the TAB tape instead of on the IC chip side has become widely used in recent years because there is no concern of damaging the IC chip during bump bonding.
The conventional manufacturing method of TAB tape with bumps is to make leads thickly and leave only the parts that will become bumps and scrape off other parts by etching etc., or to prepare by plating on a substrate such as glass in advance. There is a method of transferring the deposited bump to the tip of the lead. However, the bumped TAB tape manufactured by these methods has a bump shape close to a rectangle, so if the bump heights are not exactly aligned, the bumps and IC chip electrodes will not be consistent. There was a drawback that was likely to occur.

The present inventors previously applied for a new method for forming a spherical bump on the lead tip of a TAB tape as Japanese Patent Application No. 1-234917. In this method, the back side of the substrate with through holes aligned with the positions where the bumps are to be arranged is sucked into a vacuum, the metal balls that will become the bumps are sucked into the through holes and temporarily fixed, and then the TAB tape leads And the metal spheres arranged and temporarily fixed on the substrate are overlapped and joined.

[Problems to be Solved by the Invention]

Spherical bumps are easier to deform than conventional rectangular bumps formed by plating on a glass substrate,
It is advantageous in terms of joining. However, when the bumps are formed by plating, it is possible to specify and form a predetermined position to be arranged from the beginning, whereas spherical bumps are manufactured in a disjointed state, so A big problem is how to efficiently arrange the positions.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a method for arranging fine metal spheres capable of arranging fine metal spheres at a predetermined position efficiently and reliably. .

[Means for Solving the Problems]

The method for arranging fine metal spheres according to the present invention for achieving the above object is characterized by arranging fine metal spheres on a substrate in an ionized atmosphere.

[Action]

According to the present invention, by arranging the fine metal spheres at a predetermined position on the substrate in the ionized atmosphere, the charged fine metal spheres and the fine metal spheres charged when arranged are It exchanges electric charge with the ionized atmosphere and becomes electrically neutral, preventing the aggregation of fine metal spheres due to static electricity and the adhesion of fine metal spheres to positions other than the prescribed position. To do.

〔Example〕

A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a diagram for explaining a method for arranging fine metal balls according to the first embodiment of the present invention, and FIG. 2 (a) is an arrangement portion of a fine metal ball arranging device used in the method for arranging fine metal balls. FIG. 3B is a schematic cross-sectional view of the array portion, and FIG. 3 is a schematic configuration diagram of a bump transfer device using the bump array device. In this embodiment, bumps having a spherical shape with a diameter of 80 μm are used.

The bump transfer device shown in FIG. 3 includes a bump arranging device 4 for sucking the bumps 2 and arranging them at a predetermined position, and a TAB tape 22.
A mechanism (not shown) for feeding the tape and the lead 26 of the TAB tape 22.
And a bonding tool 6 that heats and pressurizes in order to transfer the bump 2 to the tip of the.

The bump arrangement device 4 includes a bump supply unit 8 and an arrangement unit 10.
And an ion gun (for example, Ioclean Gun manufactured by Simco Japan Co., Ltd.) 30 as an ion generator. The array unit 10 includes a substrate 12 for bump array and an exhaust unit 20 as shown in FIGS.
And the suction unit 14 whose interior is decompressed by. Further, the array unit 10 and the exhaust unit 20 are connected via an exhaust pipe 16.

The ion gun 30 ionizes air from, for example, a compressor (not shown) and emits the generated ions as an ion beam.

In the array portion 10 of this embodiment, a substrate 12 made of nickel and having a thickness of 30 μm is used. Through holes 13 having a diameter of about 60 μm are provided on the substrate 12 at all positions where the bumps 2 should be arranged. The suction part 14 is provided with an opening 15 corresponding to the through hole 13.

In order to arrange the bumps in a predetermined pattern and transfer them to the TAB tape by using this device, first, the exhaust unit 20 is operated to operate the exhaust pipe 16
The inside of the suction unit 14 is depressurized via. Then, a suction force is generated on the front side of the through hole 13. At this time, as shown in FIG. 1, the array portion 10 is brought close to the bump supply portion 8 on which a large number of bumps 2 are mounted, and the ion beam is irradiated by the ion gun 30 onto the periphery of the substrate 12 and the bump supply portion 8. Meanwhile, the bump 2 is sucked into the through hole 13.

Further, for example, the array portion 10 is installed so that the substrate 12 is on the upper side, and while the atmosphere around the substrate 12 is ionized by the ion gun 30, the bumps 2 are sprinkled on the substrate 12 so that the bumps 2 are formed in the through holes 13. You may make it suck.

By the way, when the bumps are sucked, if the periphery of the bumps is not irradiated with an ion beam (that is, the gas around the bumps is not ionized), the bumps charged by friction or the like aggregate with each other, and these bumps are separated by one. They may collect in the through holes or adhere to positions other than the through holes 13 of the substrate 12. If such agglomeration of bumps occurs, the yield will naturally decrease significantly when the bumps are transferred to the lead tips of the TAB tape.

In the method of arranging the fine metal spheres of this embodiment, an ion gun is used.
By irradiating the ion beam with 30, the bumps 2 are attracted to the substrate 12 in the ionized atmosphere,
The charged and aggregated bumps exchange electric charges with the ionized gas to become electrically neutral. Further, the bumps 2 charged by friction with other bumps 2 during suction also become neutral. Therefore, static electricity does not work between the bumps, and the bumps do not aggregate.
The bumps 2 can be arranged one by one.

After sucking and arranging the bumps 2, the substrate 12 of the bump arranging device 4 serves as a bonding receiving portion. First, the TAB tape 22 having the leads 26 formed on the film carrier 24 made of an insulating material such as polyimide and the substrate 12 are formed.
The position between and is adjusted using a positioning adjustment mechanism section (not shown). Once the position of the bump arranging device 4 is decided,
By applying a constant charge by the bonding tool 6 heated to an appropriate temperature, the bumps 2 attracted to the through holes 13 are transferred / bonded to the desired tip ends of the leads 26 of the TAB tape.

The bump arranging device 4, which has copied the bumps 2, returns to the step of arranging the bumps again, and at the same time, the TAB tape 22 is sent for one frame and a new frame is sent to the transfer position. After the position of is adjusted, the next bump 2 is transferred and joined to the tip of the lead 26 of the TAB tape 22.

As described above, in the method of arranging the fine metal spheres of the present embodiment, the bumps can be surely arranged one by one in the predetermined arrangement position by providing the static electricity removing measures.
It is possible to significantly improve the yield when transferring the bumps to the lead tips of the TAB tape.

Next, a second embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG. 4 is a diagram for explaining a method for arranging fine metal balls according to a second embodiment of the present invention, and FIG. 5 (a) is a schematic perspective view of a substrate of a bump arranging device used in the method for arranging fine metal balls. FIG. 2B is a schematic sectional view of the substrate. The size of the bump used is the same as in the first embodiment.

The bump arranging device shown in FIG. 4 has a bump supply unit 80, a substrate 120, and an ion blower (A300 type, manufactured by Simco Japan Co., Ltd.) 300 as an ion generator. Board 1
A hole 130 having a diameter of 100 μm, which is slightly larger than the bump 2, is provided at a position corresponding to the array pattern on the 20. The depth of the hole 130 is 60 μm. The ion blower 300 is a device that gently blows out the inactivated gas.

In order to arrange the bumps in a predetermined pattern using the above bump arranging device, the substrate 120 is first tilted and the bumps 2 of the bump supply unit 80 are rolled onto the substrate 120 from above the substrate 120. At this time, while the gas ionized by the ion blower 300 is blown around the bumps 2 rolling on the substrate 120, the bumps 2 are dropped into the holes 130 and the bumps are arranged at predetermined positions.

Also in the method of arranging the fine metal spheres of the present embodiment, the ionized gas is blown to the substrate 120 or the bumps 2 to wrap the periphery of the substrate 120 in the ionized atmosphere, and the charged bumps are electrically charged by the ionized gas. Become neutral. Further, when the bumps are charged due to friction with the substrate or another bump when rolling on the substrate, the neutralization of the bumps can be achieved. Therefore, since static electricity does not work between the bumps, one bump can be easily arranged in each hole 130.

After arranging the bumps 2 at predetermined positions, the bumps can be transferred and bonded to the lead tips of the TAB tape by using the substrate 120 as a bonding receiving portion in the same manner as in the first embodiment. Other functions and effects are similar to those of the first embodiment.

In the first embodiment described above, the case where the ion gun is used as the ion generator has been described, but the present invention is not limited to this, and the ion blower used in the second embodiment is used. Good. The same applies to the second embodiment described above.

〔The invention's effect〕

As described above, according to the present invention, by electrically neutralizing the charged fine metal spheres or the charged fine metal spheres when arrayed, the aggregation of the fine metal spheres is prevented,
A method for arranging fine metal spheres, which makes it possible to surely arrange the fine metal spheres one by one at a predetermined position, and thus significantly improve the yield when transferring the fine metal spheres to the lead portion of the TAB tape. Can be provided.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a method for arranging fine metal balls according to a first embodiment of the present invention, and FIG. 2 (a) is a schematic perspective view of an arrangement portion of a bump arranging device used in the method for arranging fine metal balls. FIG. 1B is a schematic sectional view of the array portion, FIG. 3 is a schematic configuration diagram of a bump transfer device using the bump array device, and FIG. 4 is a second embodiment of the present invention. FIG. 5 (a) is a schematic perspective view of a substrate of a bump arranging device used in the method of arranging fine metal spheres, and FIG. 5 (b) is a schematic sectional view of the substrate. . 2 ... Bump, 4 ... Bump arrangement device, 6 ... Bonding tool, 8,80 ... Bump supply unit, 10 ... Arrangement unit, 1
2,120 ... Substrate, 13,130 ... Hole, 14 ... Suction part, 15 ...
Opening part, 16 …… Exhaust pipe, 20 …… Exhaust part, 22 …… TAB tape, 24 …… Film carrier, 26 …… Lead, 30 …… Ion gun, 300 …… Ion blower.

Claims (1)

[Claims] 1. A method of arranging fine metal balls on a substrate in an ionized atmosphere.