JPH04120735A - Bump-forming tool and device - Google Patents

Abstract

PURPOSE:To prevent cracks from being generated in a semiconductor element by perfoming contact bonding of a metal material such as gold and a punched metal small piece using a metal lead, etc., for generating a large adhesion force at the metal lead and the bump part. CONSTITUTION:A metal material 6 is supplied to a punch holder 3 through a metal material supply hole 5. A dice hole 2 is provided on a lower surface of the metal material supply hole 5 so that it has same central axis with a punch sliding guide part 7. The punch holder 3 is positioned on a metal lead 9 and a tip press part 24 of a punch regulation guide 8 is allowed to contact the metal lead 9. A punch 1 is pressed from an upper part and is lowered. At this time, a metal small piece 10 is punched from the metal material 6 by the dice hole 2 and the punch 1. The punched metal small piece 10 continues to be pressed down by the punch 1 and is pushed onto the metal lead 9. At this time, the metal small piece 10 becomes a pump in a specified shaped by the regulation guide 8.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to the formation of bumps for bonding between semiconductor device electrode pads and metal leads, and bumps between metal leads and contact terminals that require electrical contact. The present invention relates to an applicable bump forming jig and bump forming apparatus.

[Conventional technology]

In recent years, many ICs and LS are used in industrial equipment and home appliances.
Semiconductor devices such as I and metal lead contacts have been incorporated. These industrial equipment and home appliances are becoming smaller and thinner year by year, and their constituent parts, such as semiconductor elements and metal lead contacts, are also required to be smaller, thinner, and more reliable.

Generally, metal protrusions called bumps are required to connect semiconductor element electrodes and metal leads, and plating is a common method for forming these bumps. In the plating method, a diffusion prevention layer of Cu, Pt, etc. is formed on the semiconductor element electrode, and Au plating is applied thereon to form a bump.

Other than the plating method, there are a ball bump method that uses pole bonding technology, and a transfer bump method that transfers bumps formed by the plating method to metal leads. The above-mentioned bump forming methods have drawbacks such as complicated steps, high formation costs, and low reliability, and a bump forming method using press working is currently proposed.

The bump forming method using conventional press processing technology uses a relatively large press machine to press multiple metal leads at once and lower them using an upper die and a lower die so that the tip of the metal lead becomes convex. The metal lead tip was bent or plastically deformed by crushing the metal lead at a predetermined position from the tip of the metal lead using an upper die, so that the tip of the metal lead became convex.

[Problem to be solved by the invention]

The above-mentioned conventional bump forming technique using press processing deforms the tip of the metal lead and connects it to the semiconductor element electrode as a bump, and the bonding is achieved by using Au or Sn plated on the aluminum electrode and the surface of the metal lead. However, the plating described above is generally 2 μm or less and cannot generate a large bonding force between the metal lead bump part and the aluminum electrode part, and has the disadvantage that cracks are likely to occur in the semiconductor element. Ta.

In addition, a large press machine is required to press a large number of metal leads at once, and highly accurate alignment of the upper and lower molds is required to deform the metal leads one by one. There was a drawback.

[Means to solve the problem]

The bump forming jig of the present invention includes a punch for punching, a sliding guide portion of the punch for punching, a die hole, and a punch holder integrally formed with a supply hole for supplying a tape-shaped metal material on the upper surface of the die hole. , a feeding mechanism that sequentially feeds the metal material a predetermined length, and a drive mechanism that causes the punch to perform a punching operation, the drive mechanism causes the punch to perform a punching operation, and the tip of the punch The present invention is characterized in that a small metal piece inserted into the die hole and punched out from the metal material is pressed with the tip of the punch to form a bump on the object to be bumped.

Further, the bump forming apparatus of the present invention includes a punch holder, which is integrally formed with a punch for punching, a sliding guide portion of the punch, a die hole, and a supply hole for supplying a tape-shaped metal material on the upper surface of the die hole. , a bump forming jig having a feeding mechanism that sequentially feeds the metal material to a predetermined length, a drive mechanism that provides a punching operation to the punching punch, and a moving mechanism that moves the bump forming jig vertically and horizontally. The moving mechanism aligns the bump forming jig to a position where bumps are to be formed on the object to be bumped, and then the driving mechanism causes the punch to perform a punching operation, and the tip of the punch is moved to the position where the bump is to be formed. The present invention is characterized in that a small metal piece inserted into a die hole and punched out of the metal material is pressed with the tip of the punch to form a bump on the object to be bumped.

〔Example〕

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

FIG. 1 is a half sectional view showing a punch halter of a bump forming jig according to an embodiment of the present invention. The punch holder 3 is integrally formed with the punch sliding guide portion 7, the die hole 2, and the metal material supply hole 5. The punch 1 is guided by a punch sliding guide 7, pressurized from above and lowered, and pushed back upward by a spring 4.

The metal material 6 is supplied to the punch holder 3 through the metal material supply hole 5. The die hole 2 is provided on the lower surface of the metal material supply hole 5 so as to be coaxial with the punch sliding guide section 7. Thereby, the punch 1 can be reliably aligned with the die hole 2, and the size can be reduced.

In addition, in this embodiment, when a small metal piece punched at the tip of the punch holder 3 is crimped onto a metal lead, etc., the bump is used to prevent the shape from being crushed by the punch 1 and become flat, and to form a bump in a predetermined shape. A regulation guide 8 is provided below the die hole 2.

FIG. 2 shows the process of forming bumps on metal leads using this embodiment.

The punch holder 3 is positioned on the metal lead 9, and the presser portion 24 at the tip of the bump regulating guide 8 is brought into contact with the metal lead 9 [FIG. 2(a)]. Pressure is applied to the punch 1 from above and it moves downward.

At this time, a small metal piece 10 is punched out from the metal material 6 using the die hole 2 and the punch 1. [Figure 2 (b)]. The punched metal piece 10 is continuously pressed down by the punch 1 and pressed onto the metal lead 9. At this time, the small metal piece 10 becomes a bump of a predetermined shape by the bump regulating guide 8 (FIG. 2(C)).

Further, FIG. 3 is a perspective view of a bump forming jig in which a metal material feeding mechanism and a punch pressing mechanism are added to the punch holder shown in FIG. 1. That is, the metal material 6 is wound around the supply reel 11 in the form of a tape, and the tip of the metal material 6 passes through the metal material supply hole 5 at the tip of the punch holder 3 and is attached to the take-up reel 12. The supply reel 11 and the take-up reel 12 constitute a feeding mechanism.

When continuously forming bumps, after the punching and crimping process described above with reference to FIG. 2, the take-up reel 12 is rotated by a predetermined amount to move the metal material 6 of the punch holder 3. By repeating this punching, crimping, and feeding of the metal material 6, bumps can be continuously formed on the metal lead 9. Furthermore, a piezoelectric element 13 is used as a drive mechanism that applies pressure and movement amount to the punch 1. Piezoelectric element 13
The amount of displacement and generated load can be selected depending on the applied voltage. In this embodiment, since the amount of displacement of the piezoelectric element 13 alone is insufficient, the piezoelectric element 13 is incorporated into the amplitude expansion mechanism 14 to obtain a predetermined pressure and movement amount to the punch 1.

FIG. 4 is a block diagram of a TAB tape bump forming apparatus using the bump forming jig shown in FIG. 3. The bump forming jig shown in FIG. 3 is attached to a orthogonal robot having horizontal and vertical movement functions, which is a combination of an X-axis moving mechanism 16, a Y-axis moving mechanism 15, and a Z-axis moving mechanism 17. The orthogonal robot controls the position of the bump forming jig using a computer into which TAB tape data is input in advance.

With the above configuration, the bump forming jig is positioned and lowered so that the tip of the punch holder 3 contacts the upper surface of a predetermined part of the metal lead of the TAB tape 23, and after the bump formation is completed, it is moved again to the next metal lead part. Perform positioning. This makes it possible to continuously form bumps on a large number of metal leads at high speed.

The TAB tape 23 is sequentially fed out from the TAB supply reel 18, and after bumps are formed on the TAB tape fixing stage 22, it is wound up and collected by the TAB take-up reel 19. TAB supply tension roller 20 and T
AB winding tension roll 21 is TAB tape 2
3 to bring the TAB tape 23 to a predetermined position on the TAB tape fixing stage 22.

By using the bump forming apparatus configured as described above, it is possible to form bumps continuously on the metal leads of the TAB tape at high speed.

Note that as the metal material 6, in addition to Au, a laminated material such as Au and Cu can be used.

〔Effect of the invention〕

As explained above, the bump forming jig and bump forming apparatus of the present invention generate a large bonding force between the metal lead and the bump by crimping a metal material such as gold and a small metal piece punched out to the metal lead. This has the effect of preventing cracks from occurring in the semiconductor element.

Furthermore, the present invention eliminates the need for a large press machine because each bumper is pressed and punching of a metal material such as gold requires less force than deforming a metal lead. Further, by integrating the punch sliding guide portion and the die hole, there is an effect that high-precision assembly such as alignment of the upper metal and the lower metal is not required.

Furthermore, the bump forming jig can punch out a small piece of metal and press it onto a metal lead with a single action of the punch.
The bump forming process is simple and bumps can be formed at high speed. When forming a large number of bumps continuously at high speed, the weight of the bump forming jig becomes a problem. If the weight of the bump forming jig is large, the load on the orthogonal robot that moves the bump forming jig in the X, Y, and Z axes becomes large, and a large driving force is required. For this reason, equipment costs tend to increase.

The bump forming jig of the present invention simplifies punching, reduces weight, and enables high speed and low equipment costs.

In addition, since the die part of the punch sliding guide part has an integrated structure, repeatability is good, and the height and outer diameter of the bump can be controlled by the regulation guide, making stable bonding with semiconductor electrodes possible. .

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a punch holder of a bump forming jig according to an embodiment of the present invention, and FIGS. 2(a) to 2(c) are steps for explaining the operation of the embodiment shown in FIG. Cross section, 3rd
The figure is a perspective view of the bump forming jig including the metal material supply and winding part incorporating the punch holder shown in Fig. 1, and the bump forming jig shown in Fig. 4.
This figure is a configuration diagram of a bump forming apparatus incorporating the bump forming jig shown in FIG. 3. 1... Punch, 2... Dice hole, 3.
... Punch holder, 4...Spring, 5
・Old...Metal material supply hole, 6...Metal material, 7
...Punch sliding guide part, 8 ...Bump regulation guide, 9 ...Metal lead, 10 ...
...Small metal piece, 11...Supply reel, 12...
・Wind-up reel, 13... Voltage element, 14.
...Amplitude expansion mechanism, 15...X-axis movement mechanism, 16...X-axis movement mechanism, 17...Four Z-axis movement mechanism, 18... TAB supply reel, 19.
...TAB winding reel, 20...T
AB supply tension roller, 21...TAB
Tension roller for winding, 22...TAB
Tape fixing stage, 23...TAB tape,
24... Presser section.

Claims (1)

[Scope of Claims] 1. A punch holder integrally formed with a punch for punching, a sliding guide portion of the punch for punching, a die hole, and a supply hole for supplying a tape-shaped metal material on the upper surface of the die hole; It includes a feeding mechanism that sequentially feeds the metal material a predetermined length, and a drive mechanism that causes the punch to perform a punching operation, and the drive mechanism causes the punch to perform a punching operation, and the tip of the punch A bump forming jig, characterized in that a small metal piece inserted into a die hole and punched out from the metal material is pressed with the tip of the punch to form a bump on an object to be bumped. 2. The bump forming jig according to claim 1, further comprising a bump regulating guide section for regulating the bump shape below the die hole, and a presser section for pressing the bump forming object at the tip of the bump regulating guide section. 3. A punch holder integrally formed with a punch for punching, a sliding guide part of the punch, a die hole, and a supply hole for supplying a tape-shaped metal material on the upper surface of the die hole, and a punch holder that is integrally formed with a punch for punching, a sliding guide part of the punch, a die hole, and a supply hole for supplying a tape-shaped metal material to the upper surface of the die hole, and a punch holder that sequentially holds the metal material to a predetermined length. a bump forming jig having a feeding mechanism for feeding the punch, a driving mechanism for providing a punching operation to the punch for punching, and a moving mechanism for moving the bump forming jig vertically and horizontally; After aligning the bump forming jig to the position where a bump is to be formed on the object to be bumped, the drive mechanism causes the punch to perform a punching operation, and the tip of the punch is inserted into the die hole to form a bump on the metal. A bump forming apparatus characterized in that a small metal piece punched out of a material is pressed against the tip of the punch for forming a bump on the object to be bumped.