JPH0244518Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a wire bonder, and in particular to a synchronized drive mechanism for a wire feeding spool and a capillary.

2. Description of the Related Art In the manufacturing process of semiconductor devices, a wire bonder as shown in FIG. 2 is used for the purpose of connecting semiconductor pellets and leads with fine diameter wires made of Au or Ag. In the conventional wire bonder, a horn 4 is floatingly supported on an XY table 1 so as to be movable up and down, and a vibrator 2 is fixed to one end of the horn, and a capillary 5 with a hole for inserting a wire 3 is fixed to the other end to generate ultrasonic waves. It forms a vibration transmission mechanism. On the other hand, along the feeding path of the wire 3 pulled out from the spool 6, there is an air blowing nozzle 7 that functions as a back tensioner, a clamper 8 that controls the feeding length of the wire 3 in synchronization with the horizontal movement of the XY table 1, and a glass-made clamper 8. By sequentially arranging the guide tubes 9, a feeding mechanism for the wire 3 to be welded to the semiconductor pellet 10 and the lead 11 is formed.

Problems to be Solved by the Invention In the conventional wire bonder described above, when the horn 4 moves up and down, the supply spool 6 of the wire 3 remains at a predetermined position on the XY table 1 regardless of the movement of the horn 4. Therefore, in order to feed a predetermined length of wire 3 from the capillary 5 to the bonding position of the semiconductor pellet 10 and lead plate 11 in an intermittent feeding method, the operation timing of the air blowing nozzle 7 and the clamper 8 must be adjusted to the timing of the horn 4. It is necessary to precisely synchronize the vertical movement stroke. However, since the tension acting on the wire 3 varies greatly depending on the diameter and feeding speed of the wire layer wound on the spool 6,
If only the operating timing of the air blowing nozzle 7 and the clamper 8 are adjusted, the overfeed of the wire 3 will accumulate, and the overfeed of the wire 3 will accumulate between the semiconductor pellet 10 and the lead 11 for a predetermined period of time from the initial stage of feeding until the entire amount is fed out. It is difficult to keep the shape of the bonded wire loop constant. To explain in more detail, when the horn 4 is given vertical motion for intermittent feeding of the wire 3, the spool 6 is supported in a stationary state at a predetermined position on the XY table 1, regardless of the movement of the horn 4. Therefore, as the horn 4 moves up and down, the length of the wire 3 fed out from the spool 6 becomes longer, and the amount of overfeed of the wire 3 increases cumulatively as the operating time passes. If this overfeed state of the wire 3 is left unchecked, the length of the wire 3 sent out from the capillary 5 will not be uniform, and curls will occur in the wire 3 bonded between the semiconductor pellet 10 and the lead 11. or the shape of the wire loop becomes irregular. In order to prevent such irregularities and curls in the loop shape of the wire 3, in conventional wire bonders,
The operation timing of the clamper 8 and the air blowing nozzle 7 is synchronized with the vertical movement of the horn 4, and back tension is applied to the wire 3. As a result, the wire 3 fed out by the amount of the vertical movement of the horn 4 is transferred to the capillary 5. However, since the magnitude of this pulling force and its operation timing are affected by the operating accuracy of the air blowing nozzle and the clamper 8, it is necessary to keep the fluctuation in the length of the wire 3 sent out each time within an allowable range. The operation of the wire bonder must be periodically stopped to adjust the operation timing, which has a negative impact on improving the productivity of the wire bonding process.

The main object of the present invention is to provide a wire bonder equipped with a movable spool that absorbs wire overfeed in synchronization with the vertical movement of the horn, which can solve the above-mentioned problems of conventional wire bonders. It is in.

Means for Solving the Problems As a means for solving the above problems, the present invention has a spool for supplying wire and a bonding arm equipped with a capillary at the tip on a table that moves in the X-axis and Y-axis directions. In what was established,
The present invention provides a wire bonder in which two cams for individually driving the spool and bonding arm are rotatably mounted on an XY table, and the cams form a synchronized drive mechanism for the spool and bonding arm.

By moving the bonding arm and the spool up and down in synchronization, a wire bonder with excellent operational stability is constructed in which the wire is not overfeed from the spool.

Embodiment FIG. 1 is a schematic front view of the main parts of the device of the present invention.
In the following description, the same constituent members as those in FIG. 2 are indicated by the same reference numerals, and explanations regarding the same items will be omitted. The wire bonder has a support arm 1 having a wire supplying spool 6 fixed to its tip on a table 1 that moves in the X-axis and Y-axis directions.
9 and a bonding arm or bonding arm 4 having a capillary 5 at its tip and a vibrator (not shown) fixed at an appropriate position at its base end to form a feeding mechanism for the wire 3. There is. The XY table 1 has two end cams 20 and 21 that individually drive the support arm 19 and the bonding arm 4, which are connected to a common rotating shaft 22 to which a motor (not shown) is connected at one end. It is rotatably supported in a fixed state. The support arm 19 and the bonding arm 4 each have pins 23 and 24 fixed to a base (not shown).
The first cam follower 2 is swingably supported by the support arm 19 and is attached to the base end of the support arm 19.
6 and the second cam follower 27 attached to the base end of the bonding arm 4 to the end cam 2.
0,21, the spool 6
and forms a synchronized drive mechanism for the capillary 5.

Since the wire bonder according to the present invention is constructed as described above, the semiconductor pellet 10 and the lead 11
When the common rotating shaft 22 rotates by starting the motor and the bonding arm 4 rotates counterclockwise about the pin 24 to form a loop of the wire 3 between the support arm of the spool 6 and 19 also rotates counterclockwise around the pin 23 in synchronization with the bonding arm 4. Further, when the bonding arm 4 which has completed the connection operation of the wire 3 rotates clockwise to return to its original position, the support arm 19 of the spool 6 also rotates clockwise in synchronization with the bonding arm 4. By adopting such a synchronized drive mechanism, it is possible to eliminate overfeed in which the distance between the spool 6 fixed to the tip of the support arm 19 and the capillary 5 fixed to the tip of the bonding arm 4 is always kept constant. A suitable wire delivery device is provided.

Effects of the Invention According to the present invention, wire feeding conditions in which the distance between the spool and the capillary does not change throughout the entire bonding cycle can be easily ensured. Therefore, even if the functions of the clamper or the back tensioner deteriorate to some extent, overfeed of the wire can be reliably suppressed. Thus, the present invention is
In preventing wire curls and irregular loop shapes caused by wire overfeed, it is possible to exhibit effects that are far superior to those of conventional devices.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view of the main parts of the device of the present invention;
FIG. 2 is a schematic front view of a conventional wire bonder. 4...Bonding arm, 6...Spool,
19... Spool support arm, 20, 21... Cam, 26, 27... Cam follower.

Claims (1)

[Scope of utility model registration request] On a table moving in the X-axis and Y-axis directions,
In a device equipped with a spool for wire supply and a bonding arm equipped with a capillary at the tip, two cams that individually drive the spool and bonding arm are rotatably mounted on the XY table, and the cam A wire bonder characterized in that a synchronized drive mechanism for the spool and bonding arm is formed by: