JPH0244740A - Method and apparatus for wire bonding - Google Patents

Abstract

PURPOSE:To effectively bond without fail by reducing the inclination of a wire in the wire guide hole of a bonding wedge, then increasing the inclination of the wire, and performing first and second bindings. CONSTITUTION:A first slider 8 is vertically movably provided along a first slide face 7 having the same inclination of 60 deg. as that of a wire 5 at the end of an arm 2, and a second slider 10 is vertically movably provided along a second slide face 9 having an inclination of 135 deg. directed toward the wedge 4 of the slider 8. For example, when the inclination of the wire is 30 deg. and a first bonding is conducted, a first bonding margin of predetermined length is effectively brought into pressure contact with a first bonding part, and the inclination of the wire is set to, for example, 60 deg., and a second bonding is conducted. Thus, both the first and second bondings can be effectively performed without fail.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a bonding wedge (industrial application field) which has a wire guide hole through which a wire is inserted, which is inclined with respect to the distal end surface, and in which the wire is paid out at an angle downward from the distal end surface. (hereinafter abbreviated as wedge)
The present invention relates to a wire bonding method and apparatus for performing wire bonding using ultrasonic waves.

[Conventional technology]

Currently used wedges each guide the wire at a specific angle. For example, a wedge for 30'', a wedge for 45', and a wedge for 606 are manufactured separately and used for different purposes.

Fig. 9(a) is an example of an xy screw 25 equipped with a wire guide hole 24 that guides the wire 5 at an inclination of 30'' (9th issue)
This is an example of a sea urchin 7 27 equipped with a wire guide hole 26 that guides at an inclination 60@.

[Problems to be Solved by the Invention] By the way, in the first bonding, the smaller the inclination of the wire tip which becomes the first bonding margin, the more reliably the predetermined length 2
This is preferable because the first bonding margin can be pushed down onto the first bonding portion. In addition, although the first bonding is generally performed on the band of the IC chip 21,
Since there are no electronic components such as tall pins 23 around the chip 21, there is no problem even if the inclination of the wire 5 leading to the sea urchin 7 is small. However, there may be a pin 23 or the like near the second bonding part 22 on the substrate 3, and if the inclination of the wire 5 leading to the wedge is small, the wire 5 will hit the pin 23, causing a problem.

For example, when performing the first bonding to the pad of the IC chip 21 fixed to the substrate 3 using the wedge 25 shown in FIG. However, since the inclination of the wire 5 introduced into the wire guide hole 26 is also 30 degrees when performing the second bonding, the wire 5 may hit the pin 23, which is inconvenient.

When using wedge 27 (No. 9), it is the opposite of the above,
The second bonding can be performed without any problem, but in the first bonding in which the first bonding margin led out obliquely from the tip surface 20 of the wedge 27 is bonded to the pad of the IC chip 21, the first bonding margin at the tip of the wire 5 is For bonding, the inclination of the IC chip 21 with respect to the pad is also large 11 with the same angle as the wire guide hole 26! Therefore, even if the wedge 27 is lowered straight down, the wire 5 is difficult to bend at a distance l from its tip, and as the wedge 27 is lowered, the wire 5 is bent and relatively bent into the wire guide hole. I ran back into 26,
A bonding margin of length i required for bonding cannot be pressed between the tip end surface 20 of the wedge 27 and the pad of the IC chip 21, and accurate first bonding cannot be performed. To avoid this, the wire 5 can be let out by a length that protrudes outward from the pad, but this has the disadvantage that the tip of the protruding wire may short-circuit, and the wire 5 is also wasted.

The present invention aims to solve the above-mentioned conventional problems, and provides a wire bonding method that can reliably perform both the first bonding and the second bonding without any problems, and a wire bonding device suitable for carrying out the method. The purpose is to provide the following.

[Means for solving problems]

The invention according to claim 1 is a wire bonding method in which wire bonding is performed using a bonding wedge, in which the inclination of a straight wire from the wire guide hole to the tip of the wire is reduced by reducing the inclination of the wire in the wire guide hole of the bonding wedge. Perform the first bonding by making the wire smaller, and then perform the second bonding by increasing the inclination of the wire in the wire guide hole of the bonding wedge to increase the inclination of the straight wire from the front of the wire guide hole to the exit of the wire guide hole. This is a wire bonding method characterized by:

The invention according to claim 2 is a wire bonding method for performing wire bonding using a bonding wedge, in which the wire is bent upward at the wire guide hole entrance of the bonding wedge to increase the inclination of the wire reaching the wire guide hole entrance. This wire bonding method is characterized in that the second bonding is performed using the wire bonding method.

According to a third aspect of the present invention, in a wire bonding apparatus equipped with a bonding wedge, a wire clamp provided on a wire path in front of the bonding wedge is provided so as to be movable up and down with respect to the bonding wedge in a direction different from the wire supply direction. This is a wire bonding device characterized by:

[For production]

The wire bonding method of the invention according to claim 1 performs the first bonding by reducing the inclination of the wire in the wire guide hole of the bonding wedge to reduce the inclination of the straight wire from the wire guide hole to the tip of the wire. By increasing the f angle of the wire in the wire guide hole of the wedge, the inclination of the straight wire from the front of the wire guide hole to the exit of the wire guide hole is increased to perform the second bonding. When the first bonding part is formed as a wire, the first bonding part of a predetermined length is securely pressed against the first bonding part, and on the other hand, for example, the inclination of the wire is
If the second bonding is performed at 0°, there is no risk of the wire touching even if a tall electronic component such as a bottle is near the second bonding part.

In the wire bonding method according to the second aspect of the present invention, the second bonding is performed by bending the wire upward at the entrance of the wire guide hole of the bonding wedge to increase the inclination of the wire leading to the wire guide hole.
If a wedge with a wire guide hole of 0" is used, the first bonding can be performed reliably with the wire tilted at 30 degrees, which is the normal usage method, and on the other hand, in the second bonding part, the wire guide hole If the inclination of the wire is set to 60 degrees, for example, the obstacle can be avoided.

In the wire bonding apparatus according to the third aspect of the present invention, the wire clamp provided on the wire path in front of the bonding wedge is movable up and down with respect to the bonding wedge in a direction different from the wire supply direction. If the wire clamp installed on the wire path in front of the bonding wedge is raised relative to the bonding wedge in a direction different from the wire feeding direction with the wire clamped, the inclination of the wire will increase, and if it is lowered, the inclination of the wire will increase. becomes smaller. Therefore, the inclination of the wire can be changed to a desired inclination by considering the moving direction and distance of the wire clamp.

(Example〕 Embodiments of the present invention will be described using the drawings.

First, an embodiment of a bonding apparatus used in the bonding method shown in FIGS. 1 and 2 will be described with reference to FIGS. 3-4. .

In Figure 3, 1 is a horn, 2 is an arm, and both are X
Both are installed on a bonding head provided on the Y table so that they can move up and down together (the XY table bonding head and the vertical movement device are not shown). 3 is the board to which wire bonding is performed, and the θ rotation It is supported via a device (not shown). A wedge 4 is provided at the tip of the horn 1 so that its longitudinal direction (the side where the wire guide holes are located is the front and the opposite side is the rear) coincides with the Y direction.

The wire 5 supplied to the wedge 4 has a standard shape Li (the state in which the wire 5 remains straight from the wire guide 6 provided in the bonding head to the exit of the wire guide hole of the wedge 4 in the figure). 601.

The tip of arm 2 has the same slope of 60″ as wire 5.
A first slider 8 is formed on the slide surface portion 7 and is provided to be movable up and down along the first slide surface portion 7 . The side surface of the first slider 8 facing the wedge 4 is 13
It is formed on the second sliding surface part 9 with an inclination of 5 m (see Fig. 4. In order to make the length l of the first bonding the same when the wire clamp 11 is at the 60° position and when the wire clamp 11 is at the 30° position. ), a second slider 10 is provided so as to be movable up and down along the second slide surface portion 9.

The second slider 10 includes a bracket part 12 to which a wire clamp (hereinafter abbreviated as "clamp") 11 is attached, and the clamp 11 is provided at the tip of the bracket part 12 so as to be openable and closable. In this example, when moving along a direction with an inclination of 60'' and moving along a direction different from the supply direction (a direction with an inclination of 135°), the wedge 4 moves up and down with respect to the wedge 4 (a pair of clamps 11). Of the clamping pieces, the front clamping piece is not shown)
.

1st. The second sliders 8 and 10 are driven by solenoids and springs (not shown).
1. to the slider 8 of each. Second solenoid 13.
14 is the first. The second sliders 8 and 10 each have a first
．． A second suction plate 15°16 is provided. The second solenoid 14 has a clamp portion at the tip of the clamp 11 (in FIGS. 2 and 4, this portion is designated by reference numeral 11) at an angle of 60° when the second slider 10 is in the raised position relative to the first slider 8. The stroke S of the second slider lO is such that the clamp part is positioned along the wire 5 (this position is referred to as the 60° position) when the second slider lO is in its lowered position. Set the slope to 30
'', as shown by the two-dot chain line (see FIG. 4, this position is referred to as the 30' position).

The first slider 8 cuts the wire 5 by raising the clamp portion that clamps the wire 5 from a lowered forward position to a raised position to a retracted position, and lowers it from the retracted position to an advanced position to cut the wire 5. The first solenoid 13 and suction plate 15 are used to reciprocate the forward position and the backward position. , a structure in which the clamp portion is moved from a forward position to an intermediate position to a backward position to a forward position will be used, and a method will be described in which cutting and feeding out of the wire 5 is reduced.

Next, the wedge 4 will be explained using FIG. 4.5.

The center part of the wire guide hole 17 of the wedge 4 is connected to the upper wall 18
is a curved wall with an inclination of 60°, and the lower wall 19 is a curved wall with an inclination of 30°, and both side walls are provided at intervals commensurate with the diameter of the wire 5, but it is not sufficient to simply make them 60° and 30°. , the wire 5 when placed in a straight state along the top wall 18 and the wire 5 when placed in a straight state along the bottom wall 19
' is provided so as to intersect on the same plane as the tip surface 20 of the wedge 4 and at a position close to the tip surface 20.

Next, the wire bonding method will be explained using FIG. 1.2.

Point A in FIG. 1(a) and point A in FIG. 2 show the wedge 4 being moved above the pad of the IC chip 21, which is the first bonding part, after the second bonding is completed, and the clamp 11 is not closed. , forward position, and 30° position.

When reaching above the pad of the IC chip 21, which is the first bonding portion, the wedge 4 and the clamp 11 are lowered together to a height where the tip end surface 20 of the wedge 4 presses the bonding margin against the pad. In this case, the slope of wire 5 is 30
Therefore, even if the wedge 4 is lowered straight down, the first bonding margin of length l is surely pressed against the band.

First bonding is performed by causing the wedge 4 to vibrate ultrasonically.

When the first bonding is completed, the clamp 11 is opened. ...The wedge 4 and the clamp 11 are raised together to an appropriate height at points B in FIG. 1(b) and FIG. 2. The second slider 10 raises the clamp 11 relative to the wedge 4 to the 60° position, setting the inclination of the wire 5 to 60'', and then raises the first slider 8 to the intermediate position (backslides along the wire 5). ).The length of the wire 5 corresponding to the movement from the forward position to the intermediate position is the bonding length l, and the length of the wire 5 between the sea urchin 7 and the clamp 11 is set in advance at this stage. will be lengthened by the first bonding length i for the first bonding of (
1st bonding and preparation for feeding). ...Figure 1 (
C), Figure 2 C point wedge 4 and clamp 11 are integrated Y
, Z (up and down) to lower the wedge 4 to the second bonding portion 22 on the base viJ. Clamp 1 already
1 has been changed to a 60° position, the inclination of the wire 5 is as large as 60'', so the wire 5 does not touch the pin 23. Furthermore, the clamp 11 prevents the wedge 4 from descending to the second bonding portion 22. It is closed just before.・
1(d), FIG. 2D After lowering, the wedge 4 is subjected to ultrasonic vibration to perform second bonding.

When the second bonding is completed, the clamp 11 is raised from the intermediate position to the retracted position, and the wire 5 is cut at the base rising from the second bonding part 22. (Wire cutting)... Point E in FIG. 1(e) and FIG. 2 The movement of the wedge 4 and the clamp 11 to the next first bonding portion of the pad (ZXY, θ of the substrate 3) is started. During movement, the clamp 11 is lowered from the retracted position to the forward position, the wire 5 is paid out, and the first bonding allowance is protruded from the distal end surface 20 of the wedge 4 (first bonding allowance payout), . . . Fig. 1 ( f), second
At point F in the figure, the clamp 11 is lowered relative to the wedge 4 by the second slider 10 to a 30° position, and the wire 5 is tilted at 30°. ...Fig. 1 (Fig. 2, point G) In the above embodiment, the protrusion of the first bonding margin of the wire 5 and the movement of the clamp 11 to the 30° position are performed in separate operations as shown in Fig. 1 (f). (Although, as shown in FIG. 6, after the second bonding is completed, the clamp 11 is raised from the forward position to the backward position by the first slider 8 to cut the wire 5, and then lowered to the forward position again. Thereafter, the clamp 11 is moved to the 30° position by the second slider lO, and at the same time the clamp 11 is lowered so as to project the first bonding margin.In this case, the inclination of the second slide surface portion 9 in FIG. The straight line AB (2) in the figure has an inclination angle α, and the stroke S1 of the second slider 10 is set to the length of the straight line AB.In this example, the first slider 8 reciprocates between the forward position and the backward position. (As shown in Figure 3, the first solenoid 13 and the first
The first slider 8 can be moved by the suction plate 15 .

FIG. 7 shows an example in which the bonding method of the present invention is carried out using the wedge 25 shown in FIG. 9 ta+.

In this example, the standard state of the wire 5 is 30 degrees, and during the second bonding, the clamp 11 is raised to the 606 position to escape the pin 23.

In this example, just before reaching the second bonding part 22, the
” position of the clamp 11 by the second slider 10
Leave it in the @ position. The inclination of the first sliding surface part 7 is 30
'', and the inclination of the second sliding surface portion 9 is the angle β, the second
The stroke of the slider 10 is S2. of course,
The length of the wire 5 from the clamp 11 at the 30° position to the exit of the wire guide hole 24 is the same as the length of the wire 5 from the clamp 11 at the 60" position to the exit of the wire guide hole 24, which is indicated by a two-dot chain line in the figure. .

The above description has been made using the example shown in FIG. 3 in which the clamp 11 is reciprocated on an oblique straight line in a direction different from the feeding direction of the wire 5 and as a vertical movement device for the wedge 4.25. However, the entire clamp 11 or only the clamp portion at the tip of the clamp is a device that rotates back and forth on an arc. For example, in an example using the wedge 4, as shown in FIG. It is also possible to carry out the method of the present invention by moving the device.

〔Effect of the invention〕

The wire bonding method of the invention of claim 1 is such that the first bonding is performed by reducing the slope of the wire in the wire guide hole of the bonding ridge 7 to reduce the inclination of the straight wire from the wire guide hole to the tip of the wire. and thicken the wire at the end of the wire guide of the bonding wedge (by doing so, the slope of the straight wire from the front of the wire guide hole to the exit of the wire guide hole is increased and the second bonding is performed, In the wire bonding method according to the second aspect of the invention, the second bonding is performed by bending the wire upward at the wire guide hole of the bonding wedge to increase the inclination of the wire reaching the wire guide hole. The first bonding.

If each second bonding is optimally selected, both the first bonding and the second bonding can be reliably performed.

In the wire bonding apparatus according to the third aspect of the invention, since the wire clamp provided on the wire path in front of the bonding wedge is movable up and down with respect to the bonding wedge in a direction different from the wire supply direction, the inclination of the wire can be prevented. It can be easily changed to the desired tilt.

[Brief explanation of the drawing]

Fig. 1 1al~ (The illusion is an explanatory diagram of the overall operation of wire bonding in which the invention of claim 1 is implemented, Fig. 2 is a time chart thereof, and Fig. 3 is a main part of the embodiment of the invention of claim 3. 4 is a longitudinal sectional view of the sea urchin 7 used to carry out the invention of claim 1, FIG. 5 is a side view of the wire guide hole entrance side, and FIG. FIG. 7 is an explanatory diagram of the operation of another embodiment of the invention of claim 2, FIG. 7 is an explanatory diagram of the operation of an example in which the invention of claim 2 is implemented using the wedge shown in FIG. FIG. 9 (b), which is an explanatory diagram of the operation of another embodiment of the invention, is a vertical sectional view of an example of a wedge currently used. 1...Horn, 2...Arm, 3...・Substrate, 4・
... Wedge, 5... Wire, 6... Wire guide, 7... First slide surface section, 8... First slider, 9... Second slide surface section, 10... Second slider, 11... Clamp, 12... Bracket portion, 13... First solenoid, 14... Second solenoid, 15... First suction plate, 16... Second suction plate, 17... wire guide hole, 18... top wall,
19... Bottom wall, 20... Tip surface, 21... IC
Chip, 22... Second bonding part, 23... Bin, 24... Wire guide hole, 25... Sea urchin 7ji,
26... Wire guide hole, 27... Wedge. Patent applicant: Kaiyo Denki Co., Ltd. Representative Patent Attorney Minoru Yakushi Representative Patent Attorney Yori 1) Takatsugu Department Representative Patent Attorney
Masayuki Takagi (a) (b)

Claims (3)

[Claims] (1) In a wire bonding method in which wire bonding is performed using a bonding wedge, the inclination of the wire in the wire guide hole of the bonding wedge is reduced to reduce the inclination of the straight wire from the wire guide hole to the tip of the wire. The first bonding is performed, and the second bonding is performed by increasing the inclination of the wire in the wire guide hole of the bonding wedge, thereby increasing the inclination of the straight wire from the front of the wire guide hole to the exit of the wire guide hole. Wire bonding method. (2) In a wire bonding method in which wire bonding is performed using a bonding wedge, the wire is bent upward at the entrance of the wire guide hole of the bonding wedge to increase the inclination of the wire leading to the wire guide hole and perform the second bonding. A wire bonding method characterized by: (3) A wire bonding apparatus equipped with a bonding wedge, characterized in that a wire clamp provided on the wire path in front of the bonding wedge is provided so as to be movable up and down with respect to the bonding wedge in a direction different from the wire supply direction. wire bonding equipment.