JPH0727928B2 - Bump array device - 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 bump arranging device used when arranging bumps according to a predetermined arranging pattern and transferring the bumps to the lead tips of TAB tapes.

[Prior Art] The TAB method is used for bonding lead wires to the electrode part of the IC chip to the tip of the lead formed by patterning on the TAB tape and the electrode part of the IC chip for bonding called bump. It is a method of joining through the metal projections. 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 at the tip of the lead 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]

The spherical bump is easier to deform than the conventional rectangular bump formed by plating on a glass substrate or the like, and is advantageous in terms of bonding. However, in the case of forming bumps 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,
A big problem is how to efficiently arrange at a predetermined position and how to easily transfer to the lead portion on the TAB tape.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a bump arranging device that can efficiently arrange and transfer bumps at predetermined positions and that has excellent durability. is there.

[Means for Solving the Problems]

A bump arranging device according to the present invention for achieving the above object is a substrate in which through holes corresponding to a bump arranging pattern are formed, a suction section having a suction opening, and a pressure reduction in the suction section. And a suction unit that secures the substrate and the suction unit so that the through hole and the opening face each other through an intermediate plate made of a porous material having air permeability in the plate thickness direction. It is characterized by.

[Action]

According to the present invention having the above structure, the pressure in the suction portion is reduced by using the exhaust means, so that the bump is sucked into the through hole facing the opening of the suction portion through the intermediate plate made of the porous material. Moreover, since the intermediate plate is attached to the substrate and the substrate can be reinforced by the intermediate plate, the substrate can be formed thin.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic exploded view of an array portion of a bump array device which is an embodiment of the present invention, FIG. 2 is a schematic sectional view of the array part, and FIG. 3 is a bump transfer device using the bump array device. It is a schematic block diagram. In this embodiment, spherical bumps having a diameter of 80 μm are used.

The bump transfer device transfers the bumps 2 to the tip of the leads 26 of the TAB tape 22, a bump arranging device 4 for sucking the bumps 2 and arranging them at a predetermined position, a mechanism (not shown) for sending out the TAB tape 22. Therefore, a bonding tool 30 for heating / pressurizing is provided.

The bump arranging device 4 includes an arranging portion 10 and an exhaust device 20. As shown in FIGS. 1 and 2, the array unit 10 includes a substrate 12 for bump array, a porous plate (intermediate plate) 14 attached below the substrate 12, and a porous plate 14 therebetween. The suction unit 16 is attached to the substrate 12. Further, the array portion 10 and the exhaust device 20 are connected via an exhaust pipe 18.

In the array portion 10 of the present embodiment, a ceramic porous plate 14 is provided between the substrate 12 and the suction portion 16. The substrate 12 is made of nickel and has a thickness of 30 μm. Through holes 13 having a diameter of 60 μm are formed on the substrate 12 at all positions where the bumps 2 should be arranged.
Is provided. The suction part 16 is provided with a substantially groove-shaped opening 17 facing the through hole 13 via the porous plate 14.
The opening 17 has a width A of 1 mm. Porous plate 1
In No. 4, the thickness B is 1.0 mm, and a large number of fine holes having a diameter of about 5 μm are formed inside the No. 4, which has air permeability in the thickness direction.

In order to arrange the bumps in a predetermined pattern and transfer them to the TAB tape using this device, first make the exhaust device 20 differential and exhaust pipe.
The inside of the suction part 16 is made into a decompressed body via 18. In this embodiment, the porous plate 14 is provided between the substrate 12 and the suction portion 16, but since the porous plate 14 is provided with a large number of fine holes, a suction force is generated in the through hole 13. be able to. At this time, the bumps 2 are attracted to the through holes 13 and arranged by, for example, a method of sprinkling the bumps 2 on the substrate 12. Further, the bump arranging device 4 may be brought close to a bump supply mechanism portion such as a tray on which a large number of bumps are mounted, and the bumps may be sucked into the through holes 13.

After the bumps 2 are attracted and arranged, 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 load with the bonding tool 30 heated to an appropriate temperature, the bumps 2 sucked in the through holes 13 are transferred / bonded to the desired tips 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 adjusting the position of
It is transferred and joined to the tip of the lead 26 of the TAB tape 22.

Since the process of arranging the bumps, the process of transferring the bumps to the TAB tape, and the process of feeding the TAB tape by one frame can be operated continuously in this way, the transfer / bonding of the bumps to the lead tips of the TAB tape can be performed. It can be done very efficiently.

By the way, when a sphere having a diameter of 80 μm is used as the bump, the through hole of the substrate must be formed in an extremely small diameter of about 60 μm. Since it is extremely difficult to accurately process such a small through hole on a thick substrate, the thickness of the substrate cannot be made too thick. 60
The thickness of the substrate is at most 30μ for drilling through holes of μm
Can only be about m. With a substrate of this thickness, if there is no porous plate, the substrate will deform during repeated heating and pressurization by the bonding tool in the process of transferring the bumps to the TAB tape, especially as shown in FIG. A dent may occur around the through hole. When the substrate is deformed in this way, the height of the bumps after the array is varied, and the substrate needs to be replaced.

In the bump arranging device of the present embodiment, the substrate is reinforced by providing the porous plate, and it is possible to withstand the pressure of the bonding tool considerably. For this reason, the deformation of the substrate, particularly the depression in the peripheral portion of the through hole described above, is unlikely to occur, and the number of times the substrate can be used is significantly increased.

Further, since the heat insulating property is improved by using the porous plate 14, it is possible to prevent the heat from the bonding tool from escaping to the suction part 16 or the like, and to transfer and bond the bumps extremely stably and efficiently. You can

FIG. 5 is a schematic perspective view showing another row of the array portion used in this embodiment. The array portion 100 shown in FIG. 5 is formed in an octagonal shape. The size and arrangement of the through holes 130 formed in the substrate 120 for each bump arrangement are the same as above. A porous plate made of ceramics is also provided under the substrate 120 in this array portion 100 as well.
140 is provided, and an exhaust pipe 180 that also serves as a rotating shaft is connected to the exhaust device 20 described above. When using the array section 100, the bumps can be easily attracted and arrayed on the substrate 120 by disposing a bump supply mechanism below the array section 100, for example. The substrate 120, which has rotated the bump arranging device 100 and has come to the upper part, serves as a bonding receiving portion, and a process of transferring the bumps to the lead tips of the TAB tape is performed.

In addition, although the case where ceramics is used as the material of the porous plate has been described in the above embodiments, the present invention is not limited to this, and porous glass or porous metal can be used. .

Further, in the above embodiments, the porous plate is described as having micropores formed in the whole, but the present invention is not limited to this, and only in the portion facing the through hole and the opening. You may use the porous plate in which the micropore was formed.

Furthermore, in the above-mentioned embodiment, the opening is described as a groove, but the opening may be, for example, the entire upper surface.

〔The invention's effect〕

As described above, according to the present invention, by using the porous plate, the bumps can be efficiently arranged and transferred at the predetermined positions without reducing the force of sucking the bumps into the through holes. Moreover, it is possible to provide a bump arranging device which can reinforce the substrate to improve the durability and further improve the heat insulating property when transferring the bumps.

[Brief description of drawings]

FIG. 1 is a schematic exploded view of an array portion of a bump array device which is an embodiment of the present invention, FIG. 2 is a schematic sectional view of the array part, and FIG. 3 is a bump transfer device using the bump array device. FIG. 4 is a schematic configuration diagram, FIG. 4 is a diagram for explaining deformation of the substrate when a porous plate is not used, and FIG. 5 is a schematic perspective view showing another example of the array portion used in this embodiment. 2 ... Bump, 4 ... Bump array device, 12 ... Substrate, 13
...... Through hole, 14 …… Porous plate, 16 …… Suction part, 17 …… Opening part, 18 …… Exhaust pipe, 22 …… TAB tape, 24 …… Film carrier, 26 …… Lead, 30 …… Bonding tool, 100 ... Array, 120 ... Substrate, 130 ... Through hole, 140
... Porous plate, 180 ... Exhaust pipe.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhiro Suzuki 1-1-1, Edamitsu, Yawatahigashi-ku, Kitakyushu, Fukuoka Prefecture Inside the Engineering Department, Nippon Steel Co., Ltd. (72) Inventor Masafumi Imada Major in Chiyoda-ku, Tokyo 2-6-3, Machi Nippon Steel Co., Ltd.

Claims (1)

[Claims] 1. A substrate in which through holes corresponding to an array pattern of bumps are formed, and a suction portion having a suction opening.
An exhaust unit for reducing the pressure in the suction unit, and the through hole and the opening face the substrate and the suction unit via an intermediate plate made of a porous material having air permeability in the plate thickness direction. A bump arranging device characterized by being fixed like this.