JPH0358536B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a wire bonding apparatus for wire bonding semiconductor components such as ICs and transistors.

2. Description of the Related Art In recent years, wire bonding apparatuses are required to perform bonding at high speed and with high density. To solve this problem, it is necessary to stably supply the wire with a constant tension.

An example of a conventional wire bonding apparatus will be described below with reference to the drawings.

3 to 5 are schematic diagrams of a conventional wire bonding apparatus and diagrams showing a wire bonding sequence. In FIGS. 3 and 4, a wire 2 wound around a wire reel 1 is supplied to a bonding tool 6 via a guide tube 3, a tension section 4, and a wire clamper 5 to perform wire bonding. FIG. 4 is a detailed view of the tension section shown in FIG. 3, and 7 is a wire holder made of ruby, glass, etc. to hold the wire and provide tension. It is fixed to the clamp arm 8, and is supported by a thin plate spring 9. It is holding wire 2 down. FIG. 5 is a diagram showing the bonding sequence, in which 10 is a chip, 12 is a board on which the chip is mounted, and 1
1 shows the loop shape of the wire 2 wired. Note that the substrate 12 is mounted on a positioning device that can perform arbitrary positioning.

The operation of the conventional wire bonding apparatus configured as described above will be explained below.

A wire 2 wound around a wire reel 1 is supplied to a bonding tool 6 via a guide tube 3, a tension section 4, and a clamper 5. The wire 2 supplied to the bonding tool 6 is shown in FIG.
As shown in e, the following operations are performed: first bonding, moving the chip and substrate, second bonding, and cutting the wire. At this time, a certain tension is applied to the wire 2 by the tension section 4. The tension section 4 has a structure shown in FIG. 4, and applies tension by holding the wire 2 under constant pressure using a wire presser 7, a clamp arm 8, and a thin plate spring 9.

Problems to be Solved by the Invention However, in the above configuration, the wire 2
Since the tension is mechanically pressed down, damage such as scratches occurs on the outer periphery of the wire 2. Further, the tension applied to the wire 2 is a very small amount that is less than the wire breaking force, and if this tension is too weak, the wire 2 will be damaged by inertia when the bonding tool 6 and the semiconductor chip 10 move relative to each other after the first bonding. Extracted more than necessary,
Since bonding cannot be performed with a constant tension during the second bonding, the shape of the loop 11 is not constant. Conversely, if the tension of the wire 2 is too strong, the ball formed at the tip of the bonding tool 6 will get stuck in the center hole of the bonding tool 6.

Further, as shown in FIG. 5e, when bonding is completed, a sag of the wire 2 occurs between the tension portion 4 and the bonding tool 6, and the wire is deformed such as bending, so that the loop shape is not constant during wiring.

As described above, conventional wire bonding devices have many problems.

In view of the above problems, the present invention provides a constant tension to the wire without causing mechanical damage, eliminates sagging of the wire so that a constant tension is always applied during wire bonding, and increases the tension applied to the wire. The present invention provides a wire bonding device that performs wire bonding in a stable loop shape by arbitrarily controlling the wire bonding strength within the range from zero to the breaking force of the wire.

Means for Solving the Problems In order to solve the above problems, the bonding apparatus of the present invention includes a vacuum column that applies tension between the wire reel and the bonding tool.

Effects The present invention uses the vacuum pressure when applying tension to the wire due to the above-described configuration, so there is no mechanical damage to the wire, and furthermore, the sag generated between the bonding tool and the vacuum column is rewound. As a result, since bonding is performed with a constant tension during bonding, the shape of the wire loop can be formed stably.

Embodiment A wire bonding apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a wire bonding apparatus according to an embodiment of the present invention, and FIG. 2 shows a sectional view of the tension portion of FIG. 1. In FIGS. 1 and 2, 13 is a wire reel around which a wire 14 is wound. 16a, 16b, 17 are spacers and guide plates forming the vacuum column 30, and the distance A between the spacers 16a, 16b can be changed to any size. 18 is a clamper for cutting the wire 14 after the second bonding;
9 is a bonding tool, and 20 and 21 are a semiconductor component and a substrate, respectively. Further, 22 and 23 indicate air flows within the vacuum column 30.

The operation of the wire bonding apparatus configured as described above will be explained with reference to FIGS. 1 and 2. Wire 1 wound on wire reel 13
4 is held in the state shown in the figure via a vacuum column 30, a clamper 18, and a bonding tool 19.
In this state, when vacuum pressure is applied between the spacers 16a and 16b in the direction of the arrow 23, the wire 14 is pressed against the side surfaces of the spacers 16a and 16b by the atmospheric pressure 22.

As described above, according to this embodiment, since the wire 14 is tensioned by the vacuum column 30, no damage occurs to the wire 14. Furthermore, even if sagging occurs in the wire 14 as shown in FIG. 5e during the bonding operation, the wire 14 can be wound back into the vacuum column 30. Also, the tension applied to the wire 14 can be adjusted using the spacer 16a.
By adjusting the distance A between and 16b, it is possible to control the degree of vacuum without adjusting it. Therefore, it is possible to stably bond a loop-shaped wire with a constant tension without damaging the wire 14 or causing sag in the wire 14.

Effects of the Invention As described above, the present invention provides a vacuum column between a wire reel and a bonding tool, which is composed of a thin plate-shaped spacer larger than the wire diameter, and guide plates that hold the spacer from both sides. It is equipped with a vacuum source that provides a vacuum, and since the tension is applied using atmospheric pressure, the wire is not damaged, and the sag generated during bonding can be rewound into the vacuum column, making it possible to tighten the wire. is always given a constant tension. Therefore, the loop shape after bonding does not tilt to the left or right depending on the relative movement of the bonding tool and the semiconductor component, making it possible to obtain a stable wire bonding loop shape.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a wire bonding device according to an embodiment of the present invention, FIG. 2 is a sectional view of FIG. 1, and FIG. 3 is a configuration diagram of a conventional bonding device.
FIG. 4 is a perspective view showing the structure of the tension section shown in FIG. 3, and FIG. 5 is a diagram showing the sequence of wire bonding. 13...Wire reel, 14...Wire, 16
a, 16b... Spacer, 17... Guide plate, 1
9...Bonding tool, 23...Vacuum source.

Claims (1)

[Claims] 1. A wire reel wound with a wire, a bonding tool for bonding the wire pulled out from the wire reel to a predetermined location, a vertically movable clamper that sandwiches the wire, and a wire disposed between the wire reel and the clamper. , a vacuum column comprising a tension section that applies a predetermined tension to the wire, the tension section being made up of a pair of spacers thicker than the diameter of the wire and a guide plate that holds the pair of spacers from both sides at a predetermined distance;
A wire bonding device comprising a vacuum source that sucks air from between a pair of spacers of the vacuum column and presses the wire against the side surface of the spacer.