JP2002033348A - Wire bonding tool Z-axis movement control device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To secure an appropriate search movement amount in a state where a ball or a laterally bent wire is projected at the tip of a capillary. SOLUTION: In addition to a work distance L ₁ and a search movement amount L ₃ which have been input conventionally, a data input means 4 uses a wire diameter L ₅ , a ball diameter BD, a chamfer diameter CD, and a chamfer angle φ.
To be able to enter and send the ball diameter of the ball protrusion amount-calculating section 5, chamfer diameter to calculate the ball protrusion amount L ₄ from the chamfer angle, high-speed movement range calculation circuit 6. The high-speed moving range calculation circuit 6 calculates L ₁ -L ₃ -L ₄ at the time of ball bonding, makes the search start position higher by L ₄ than before, and at the time of stitch bonding, calculates L ₁ -L ₃ -L ₅ . Computes, as high as L ₅ than the conventional search start position, actual search movement amount L ₃
To secure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the field of technology relating to correction of capillary search movement in a wire bonding apparatus.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional state of movement of a capillary in the Z-axis direction. Conventionally, when the capillary 1 is attached or the work 2 is changed, the capillary 1
On one of the tip is set to the Z-axis origin position A, to measure the workpiece distance L ₁ to the work position C from which the workpiece position C
Search start position B to a position above only search movement amount L ₃ from
The distance from the Z-axis origin position A to the search start position B, that is, L ₁ -L ₃ is the high-speed movement range L ₂ . The tip of the capillary 1 descends at a high speed from the Z-axis origin position A to the search start position B, from which the search movement starts at a constant speed and reaches the work position C.

[0003] Such an operation of the capillary 1 is performed by means shown in FIG. The measured work distance L ₁ and the predetermined search movement amount L ₃ are inputted by the data input means 11, and the high-speed movement range calculation circuit 1 is inputted.
The high speed movement range L ₁ -L ₂ is calculated in step ₂ and sent to the position / speed control unit 7.

When the position / speed control unit 7 sends a control signal to the capillary Z-axis drive circuit 8, the capillary Z-axis drive circuit 8 outputs a drive current to the capillary Z-axis movement motor 9, and the connected capillary 1 It will move in the Z-axis direction.

[0005] The Z-axis position detection encoder 10 detects the Z-axis position of the capillary 1 and sends position information to the position / speed control unit 7. Thereby, when the capillary 1 descends to the search start position B, control for switching to the search movement becomes possible.

[0006]

As described above, the conventional setting is performed in a state where no wire passes through the capillary 1 and no initial ball or wire exists at the tip of the capillary 1 as shown in FIG. I have. However, when bonding is actually performed, in the case of ball bonding, as shown in FIG.
6 has an initial ball 3 at the tip thereof, and in the case of stitch bonding, a wire 13 exists laterally as shown in FIG. 6B.

[0007] Consequently, to protrude downward by the ball protrusion amount L ₄ from the tip of the capillary 1 in the In the case of (a), that is Shutcho' only wire diameter L ₅ of the wire in the case of (b) Become.

Accordingly, conventionally, when the tip of the capillary 1 is lowered to the search start position B in FIG. 4 is actually not the distance L ₃ which can search movement, L ₃ -L in the case of ball bonding _4, so that only L ₃ -L ₅ in the case of stitch bonding.

If the set search movement amount L ₃
But at the same time or less the wire diameter L ₅ of the ball protrusion amount L ₄ and wire problem that Da突leave workpiece surface came reduced at a high speed movement occurs.

[0010] In order to avoid such a thing, is conventional, but came been made that the set a little longer with a margin the search amount of movement L _3, the problem that the minute useless search movement increases There is.

An object of the present invention is to set a high-speed movement range, that is, a search start position, in consideration of the amount of ball protrusion and the wire diameter of the wire in advance in consideration of the above-mentioned problems of the prior art, and Another object of the present invention is to provide a wire bonding tool Z-axis movement control device capable of securing an appropriate search movement amount in a state where an initial ball and a wire are projected.

[0012]

In order to achieve the above object, a wire bonding tool Z-axis movement control device according to the present invention is characterized by having the following components. (B) Data input means for inputting data such as work distance, search movement amount, wire diameter, wire tip ball diameter, capillary chamfer diameter, and chamfer angle (b) ball diameter, chamfer diameter, and chamfer A ball protrusion amount calculation circuit that calculates the protrusion amount of the ball that protrudes from the tip of the capillary based on each data of the fur angle. (C) The high-speed movement range obtained by subtracting the search movement amount and the wire diameter from the work distance, and A high-speed moving range calculating circuit for calculating a high-speed moving range by subtracting a search moving amount and a ball protruding amount. (D) A position / speed for outputting a control signal for the Z-axis position and speed of the capillary based on the calculated high-speed moving range. Controller (e) Capillary Z-axis that outputs capillary Z-axis drive signal based on control signal Drive circuit (f) Capillary Z-axis drive motor that drives the capillary by receiving the capillary Z-axis drive signal (g) Z-axis position detection encoder that detects the Z-axis position of the capillary and sends the detection signal to the position / speed control unit

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention, in calculating a search start position, the lower side of a wire which is laterally bent from the tip of an initial ball protruding from the tip of a capillary or from the tip of a capillary. It is intended to make the distance from to the work position an appropriate search movement amount.

The ball protrusion amount can be calculated geometrically if the diameter of the initial ball, the diameter of the chamfer of the capillary and the chamfer angle are known,
Since lugs amount from the capillary tip when the wire is out bend sideways a diameter itself of the wire, in addition to the work distance L ₁ and the search movement amount L ₃ has been conventionally input, wire diameter, Data of initial ball diameter, capillary chamfer diameter and chamfer angle can be input. After calculating the ball protrusion amount, the work distance, the search movement amount and the ball protrusion amount are used. The search start position is calculated from the search movement amount and the wire diameter.

The data may be input from the same input means or from different input means.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the wire bonding tool Z-axis movement control device of the present invention. FIG. 2 is an explanatory view of the movement of the capillary in the present invention. In FIG. 1, the work distance L ₁ , the search movement amount L
₃ , data of the wire diameter L ₅ , the ball diameter BD of the initial ball, the chamfer diameter CD of the capillary, and the chamfer angle φ are input by the data input means 4.
After these data are temporarily stored, the work distance L ₁ ,
The search moving amount L ₃ and the wire diameter L ₅ are calculated by a high-speed moving range calculating circuit 6.
Sent to Ball diameter BD, Cheung fur diameter CD and chamfer angle φ sent to the ball protrusion amount-calculating section 5, where the ball protrusion amount L ₄ from the capillary tip is calculated.

In FIG. 3, the ball protrusion amount L ₄ is
Distance S ₂ and distance S to radius CD / 2 of initial ball 3
_{It is} the difference of one. By the way, the distance S ₁ is obtained as shown in Expression 2 since Expression 1 holds.

[0018]

(Equation 1)

[0019]

(Equation 2)

Next, as for the distance S ₂ , Equation 3 is satisfied, so that Equation 4 is obtained.

[0021]

(Equation 3)

[0022]

(Equation 4)

Accordingly, the amount L ₄ of the ball protruding is represented by the following equation (5).

[0024]

(Equation 5)

The protrusion amount L _{4 of} the ball obtained in this manner.
Is sent to the high-speed movement range calculation circuit 6. In fast moving range calculating circuit 6, at the time of ball bonding is 2, than the conventional search start position B, and calculation so that only the ball protrusion amount L ₄ high position B 'becomes the search start position. Therefore, the high-speed movement range at this time is L ₁ −L
₃ a -L _4.

Further, computing as well as conventional search start position wire diameter L ₅ position higher than B during their stitch bonding is the search start position. Therefore, the high-speed movement range at this time is L ₁ −L ₃ −L ₅ . Thus, the result calculated by the high-speed movement range calculation circuit 6 is the position /
The operation is sent to the speed control unit 7, and the subsequent operation is the same as the conventional operation.

As described above, in the present invention, in addition to the conventional input data, the wire diameter, the ball diameter, the chamfer diameter, and the chamfer angle are input, and the ball protrusion amount and the wire diameter during actual bonding are taken into account. Thus, the search start position is determined, so that an appropriate amount of search movement can be secured.

[0028]

As described above, the Z-axis movement control apparatus of the present invention does not control the Z-axis movement by focusing on the tip of the capillary where no wire exists as in the prior art. In consideration of the amount of protrusion of the ball from the tip of the capillary in ball bonding and the wire diameter of the laterally bent wire at the tip of the capillary in stitch bonding, a means for setting a search start position so as to secure an appropriate search movement amount is provided. Since it was provided, the actual search movement amount became zero, the ball hit the bonding point of the workpiece while moving at high speed, the lower side of the wire hit the lead surface, On the other hand, in order to avoid such a problem, there is a problem that the amount of search movement is excessively increased and wasteful search movement increases. There is an advantage that Kunar.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a wire bonding tool Z-axis movement control device of the present invention.

FIG. 2 is an explanatory view of movement of a capillary in the present invention.

FIG. 3 is an explanatory diagram of calculating a ball protrusion amount of an initial ball in a capillary.

FIG. 4 is an explanatory view of movement of a conventional capillary.

FIG. 5 is a block diagram showing a configuration example of a conventional wire bonding tool Z-axis movement control device.

FIG. 6 is an explanatory diagram of a situation of a ball protruding from a capillary and a situation of a laterally bent wire.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Capillary 2 Work 3 Initial ball 4 Data input means 5 Ball protruding amount calculation means 6 High speed movement range calculation circuit 7 Position / speed control unit 8 Capillary Z axis drive circuit 9 Capillary Z axis movement motor 10 Z axis position detection encoder 11 Data input Means 12 High-speed moving range calculation circuit 13 Wire

Claims (1)

[Claims] 1. A Z-axis movement control device for a wire bonding tool, comprising: (B) Data input means for inputting data such as work distance, search movement amount, wire diameter, wire tip ball diameter, capillary chamfer diameter, and chamfer angle (b) ball diameter, chamfer diameter, and chamfer A ball protrusion amount calculation circuit that calculates the protrusion amount of the ball that protrudes from the tip of the capillary based on each data of the fur angle. (C) The high-speed movement range obtained by subtracting the search movement amount and wire diameter from the work distance, and from the work distance A high-speed moving range calculating circuit for calculating a high-speed moving range by subtracting a search moving amount and a ball protruding amount. (D) A position / speed for outputting a control signal for the Z-axis position and speed of the capillary based on the calculated high-speed moving range. Controller (e) Capillary Z-axis that outputs capillary Z-axis drive signal based on control signal Drive circuit (f) Capillary Z-axis drive motor that drives the capillary in response to the capillary Z-axis drive signal (g) Z-axis position detection encoder that detects the Z-axis position of the capillary and sends the detection signal to the position / speed control unit