JPS6284526A - Mounting method for gold wire for die bonding - Google Patents

Abstract

PURPOSE:To stabilize the position of mounting of a gold wire by executing a bonding with a frame of a bending section after bending for forming the bending section as the gold wire is left as it is gripped by a clamper while opening and lifting the clamper only for the time when the gold wire is pulled up for delivery from a tool after bonding. CONSTITUTION:A clamper C falls under the state in which a gold wire A is gripped by the clamper C, and a bending section B in the gold wire A is placed on the surface of a frame F. A tool T is also lowered at the same time, one end of the bending section B is pushed against the frame F by the tool and fused, and the bending section B is mounted to the frame F. The clamper C is elevated slightly as the tool T is left as it is brought to the bonding state, and the clamper is closed again. The tool T is pulled up only at a distance L. When the clamper C under the state in which it grips the gold wire is pulled up to an initial position together with the tool T, the gold wire A is torn off the bending section B and cut.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for mounting gold wire for die bonding.

(Prior art) As shown in FIG. 4, when die bonding a semiconductor pellet P to the surface of a frame F, etc.
The surface of the frame F is usually plated with gold, and pellets are placed on the surface while it is heated. Die bonding is performed by mounting, heating this to a molten state, and then placing a pellet P on the surface.

Figure 2 is for explaining the conventional gold wire mounting method, in which the gold wire A is fed out from a reel, etc., passes through a clamper C, passes through a bonding tool T, and is drawn out. . As shown in FIG. 2A, the tip of the gold wire A coming out of the tool T has already been bent into an L shape and has a bent part B.
It is assumed that the clamper C is formed and the clamper C is open.

First, the gold wire A is drawn out, and the bent portion B at the tip thereof is placed on the surface of the frame F as shown in FIG. 2B. Next, the tool T is lowered to press one end of the bent portion B against the frame F for fusing (bonding), thereby mounting the bent portion B on the frame F. Next, the tool T is raised by a distance as shown in FIG. 2C. Due to this upward movement 1, the gold wire for forming the next bent portion B is let out as if from the tool T.

Meanwhile, the clamper C has been lowered slightly in the meantime.

After its descent, it is closed and gold wire A is clamped.

Then, when the closed clamper C is pulled up to its original position, the gold wire A is torn off from the bent portion B and cut. The second diagram shows this state.

Thereafter, the bending arm M is driven in the direction of the arrow to bend the gold wire coming out from the tip of the tool T (see Fig. 2E). After this bending, the clamper C is opened and returns to its original state.

As can be understood from the above explanation, when moving from state C to state D in Figure 2, a clamper C is prepared to prevent the gold wire from being pulled in when the tool T is raised; By closing the clamper C, the gold wire A is gripped and prevented from being drawn in.

- In the state shown in Figure 2A of the force cylinder, the clamper C must be opened since it is necessary to feed out the gold wire, so the clamper C is opened from Figure 2E onwards.

However, when the grip on the gold wire is released by opening the clamper C at this time, torsion is applied due to the restoring force based on the previous curling or bending state of the gold wire, which causes the gold wire to move or twist. Sometimes I do things.

Therefore, as shown in Figure 3, if the die bonding area Q of the pellet P on the frame is the range shown by the chain line, the bent part B should originally be mounted at the center of the area Q, but the dotted line As shown, it will be mounted off center. If the pellet P is mounted in such a position, die bonding of the pellet P to the frame becomes extremely unstable.

(Problems to be Solved by the Invention) An object of the present invention is to stabilize the mounting position of a gold wire for dipon digging even if torsion may occur.

(Means for Solving the Problems) This invention performs bending to form a bent portion and bonding of the bent portion to a frame while the gold wire is gripped by a clamper, and the tool is removed after bonding. , the clamper is raised until the gold wire is pulled up for feeding out from the tool, and the clamper is opened and its grip is released only during this raising.

(Example) An embodiment of this invention will be explained with reference to FIG.

The gold wire A passes through a clamper C, passes through a bonding tool T, and is drawn out. As shown in FIG. 1A, the tip of the gold wire A coming out of the tool T has already been bent into an L shape to form a bent portion B. These conditions are the same as before.

However, it is assumed that clamper C is already closed.

First, the clamper C descends while the gold wire A is gripped by the clamper C, and the bent portion B is placed on the surface of the frame F as shown in FIG. 1B. At this time, the tool T is also lowered together with the clamper C.

Then, one end of the bent part B is pressed against the frame F by the tool T and fused (bonded), thereby mounting the bent part B on the frame F.

Next, while the tool T remains in its bonded state, the clamper C is raised slightly as shown in FIG. 1C, and then closed again. This rise ensures the lifting stroke of the tool T for the next bending portion B. Also, this clamper C is opened when it is pulled up and releases its grip on the gold wire. This release causes the clamper C to rise without pulling up the gold wire.

After this, the tool T is pulled up by a distance as shown in the first diagram. By pulling up the gold wire, it becomes as if it were being let out from the tool T. Next, when the clamper C gripping the gold wire is pulled up together with the tool T to its original position, the gold wire A is torn off from the bent portion B and cut. This state is shown in FIG. 1E.

Here, as in the conventional case, the bending arm M is driven in the direction of the arrow and bends the gold wire protruding from the tip of the tool T (see FIG. 1E).

This bending returns it to its original state.

In the above process, the bending and bonding of the gold wire were carried out while the gold wire A remained gripped by the clamper, so rotation of the gold wire during bending at the bent portion was reliably avoided. Ru.

(Effects of the Invention) As described in detail above, according to the present invention, the mounting position of the gold wire for dipon digging can be easily and reliably stabilized even if gold mLT torsion is applied.

[Brief explanation of drawings]

Fig. 1 is a front view showing the process of an embodiment of the present invention, Fig. 2 is a front view showing the conventional process, Fig. 3 is a plan view showing the gold wire mounting state, and Fig. 4 is the bonding state of the pellets. FIG. F... Frame, A... Gold wire, B... Bent part, C
... Clamper, T... Tool, P... Pellet.

Claims (1)

[Claims] a step of bending the gold wire to form a bent part at the tip thereof and bonding the bent part to a position to be bonded with a tool while the gold wire is gripped by a clamper; A method for mounting a gold wire for die bonding, which comprises the steps of opening the clamper, releasing the grip on the gold wire, and raising the gold wire before lifting the gold wire from a tool for feeding out.