JPH1187437A - Ultrasonic wire bonder using composite bend vibration system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ultrasonic wire bonder which eliminates the need for alignment of a wire bonding operation and whose operating efficiency is enhanced by a method wherein a vibration mode is controlled two-dimensionally by a composite bend vibrator which is vibrated in two orthogonal directions and a capillary for the wire bonding operation is attached to, and removed from, the tip of the vibrator. SOLUTION: Electric signals from ultrasonic oscillators which correspond to two orthogonal longitudinal vibrators 1, 2 for driving are applied to electrostrictive elements or the like in both vibrators 1, 2, the electric signals are converted into acoustic vibrations so as to be resonated, and a composite bent vibrator 5 which is coupled orthogonally to both vibrators 1, 2 is excited. Then, a capillary 6 is placed on the tip of the composite bend vibrator 5 so as to be freely detachable, a composed vibration caused by a composite bent vibration is generated at the capillary 6, its vibration track draws Lissajous' figure, and the vibration amplitude and the phase of both longitudinal vibrators 1, 2 are controlled electrically so as to be adjusted two-dimensionally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an integrated circuit (IC).
The present invention relates to a non-directional ultrasonic wire bonder applied to joining of connection lines such as surface acoustic wave devices (SAW devices) and the like.

[0002]

Conventionally, as a semiconductor for bonder is known ultrasonic bonder resonance frequency 60KH _Z.

[0003] the contents of the welding tip installed in conical horn tip of the longitudinal vibration resonance frequency 60KH _Z is, is driven by the longitudinal vibration of the conical horn induce unidirectional bending vibration,
The ultrasonic wire bonding is performed in a direction along the bonding surface with the wire at the tip of the welding tip.

[0004]

However, according to the prior art, since the vibration direction of the welding tip is one-dimensional,
Wire bonding along the length direction of the wire is indispensable, and it is necessary to position the welding tip and the conical horn so that the vibration direction and the wire length direction are the same. For this reason, the mechanical alignment time is added to the wire bonding time, resulting in a long time, and the work efficiency is reduced. Therefore, a non-directional wire bonder that is not affected by the vibration direction of the welding tip has been desired.

SUMMARY OF THE INVENTION An object of the present invention is to provide a non-directional ultrasonic wire bonder in which a capillary for wire bonding can be detached and replaced with high working efficiency.

[0006]

According to the present invention, a compound bending vibrator vibrating in two orthogonal directions controls a vibration mode of the vibrator two-dimensionally, and a capillary for wire bonding is provided at the tip of the vibrator. It has been found out that it is possible to attach and detach the same.

The present invention according to claim 1 uses a composite bending vibration system comprising two longitudinal vibrators and a composite bending vibrator which is orthogonally coupled to both of these vibrators. A hole for wire insertion is made to penetrate the center, and a capillary for wire bonding can be attached to and detached from the tip of the hole.

According to a second aspect of the present invention, in the first aspect of the present invention, the capillary is further combined with the composite bending oscillator such that the length from the tip of the composite bending oscillator to the tip of the capillary is adjustable. It can be attached to and detached from the hole of the bending oscillator.

[0009]

When an electric signal from an ultrasonic transmitter (not shown) corresponding to each of the two vibrators is applied to an electrostrictive element or the like, the two vibrators convert the electric signals into acoustic vibrations. It converts and resonates, and excites a composite bending oscillator that is orthogonally coupled to both oscillators. The capillary attached to the tip of the composite bending oscillator becomes a synthetic vibration caused by the composite bending vibration, and the vibration trajectory at the tip draws a litharge figure and electrically controls the vibration amplitude and phase of each of the vertical oscillators By doing so, two-dimensional adjustment is possible. The compound bending vibrator and the capillary have a through hole at the center of the axis. When a wire is inserted into the through hole and the compound bending vibrator is excited in an electrically adjusted vibration mode, the wire at the tip of the capillary vibrates.
The wire is rubbed under pressure with the workpiece to achieve non-directional bonding.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. The principle of the present invention is shown in FIGS. FIG. 2 assumes that the resonance frequencies of the two longitudinal vibrators are the same,
Upon controlling the respective vibration amplitude (a ₁ and a ₂₎ and the phase difference between both transducers (phi), a few of the vibration locus of the tip of the composite bending transducer.

[0011] A1 to A5 in the figure represents the case of φ = π / 2, respectively, A1 is _{a 1 = a, a 2 =} 0, A2 is a ₁
= A, a ₂ <a, A 3 is a ₁ = a ₂ = a, A 4 is a ₁ <
a = a ₂ and A5 are the resurgery figures when a ₁ = 0 and a ₂ = a. Similarly A6 is _{φ = 0, a 1 <a} 2, A7 is _{φ = π, a 1 <a} 2, A8 is _{φ = π / 4, a 1} <a 2, A
9 _{φ = 5π / 4, a 1} <a 2 ,A10wafai=pai/4,a _1>
a _2, A11 is _{φ = 5π / 4, a 1} > a 2, A12 is φ = 0,
a _1> a _2, A13 is phi = [pi, which is litharge figure in the case of a _1> a _2.

FIG. 2 shows that when the composite bending vibration system is used, the vibration direction and the wire direction of the longitudinal vibration are controlled by electrically controlling the vibration amplitude and phase difference of the two longitudinal vibrations for driving the vibration system. Non-directional wire bonding is possible without mechanically matching the length directions.

FIG. 3 shows an example in which a capillary 6 is detachably attached to the tip of a composite bending oscillator 5 by screwing with a fixing screw 8. The curve in the figure represents the relative vibration speed corresponding to the distance (L) between each point of the capillary when the length from the tip of the composite bending oscillator 5 to the tip of the capillary 6 is selected to be the optimum length.

Ceramic capillary (outer diameter 1.6 mm, hole diameter
0.7mm), the vertical oscillator drive frequency 162.1KH _Z and 51
For 4.4KH _Z , the optimum protrusion length was 6.5mm. The capillary 6 is fastened with fixing screws (M1.6, P0.5).

[0015] In FIG. 3, the B1 and B2, the amplitude characteristic when the longitudinal transducer drive frequency 162.1KH _Z, the fastening torque to the composite bending transducer of the capillary, respectively 0.4kgfcm and 0.2k
gfcm. Likewise, B3 and B4 in amplitude characteristic when the longitudinal transducer drive frequency 514.4KH _Z, respectively fastening torque to the composite bending transducer of the capillary, 0.4Kgfcm and 0.3kgf
cm.

From FIG. 3, when the projecting length of the capillary and the tightening torque are adjusted, the tip of the composite bending oscillator (point L = 0) is obtained.
As compared with the above, the vibration amplitude at the tip of the capillary is enlarged, so that the capillary can be easily replaced even when it is worn.

FIG. 1 shows an embodiment of the present invention. In the figure, reference numerals 1 and 2 denote vertical oscillators for driving the composite bending oscillator 5, and both oscillators 1 and 2 are rectangular parallelepiped portions 5A of the composite bending oscillator 5.
And one wavelength resonance length. 3 and 4 are
These are the electrostrictive element and the electrode of the vertical vibrator 2 (the vertical vibrator 1 includes the same electrostrictive element and electrode, but is omitted).

Reference numeral 6 denotes a capillary fastened to the composite bending oscillator 5 by a fixing screw 8, reference numeral 7 denotes an axial center hole of the composite bending oscillator 5 and the capillary 6, and reference numerals 9 and 10 denote longitudinal vibration modes of the vertical oscillators 1 and 2. , 11 and 12 are longitudinal oscillators 1 and 2 respectively.
And the bending vibration modes induced in the composite bending vibrator 5 at right angles to each other.

In FIG. 1, the metal part of the driving vibrator and the composite bending vibrator are made of an aluminum alloy (JIS A 50) having an outer diameter of 7 mm.
56B), the through hole of the composite bending oscillator has a hole diameter of 1.6 to
2.0mm, capillary is alumina 1.6mm in outer diameter, hole diameter
Use 0.7mm, 11.1mm length and 6.
Screws for fixing the capillary as 5mm (M1.6, P0.5
) And tighten it to the combined bending oscillator with a torque of 0.4 kgfcm.
As compared to the tip vibration speed of the composite bending vibrator, the tip vibration speed of the capillary was at least twice as high at the driving frequency of 162 KH _Z , and at least three times as high at 514 KH _Z (Fig. 3). ).

Further, by controlling the vibration amplitude and the phase difference between the two vertical vibrators, the vibration mode at the tip of the capillary becomes an electrically adjustable trajectory (FIG. 2), and a non-directional wire bonder is obtained. .

[0021]

As described in detail above, according to the present invention,
By using a compound bending vibration system to vibrate the capillary, it is not necessary to match the vibration direction of the vertical vibrator for driving this vibration system with the wire length direction, and high work efficiency and wire bonding A non-directional ultrasonic wire bonder capable of attaching, detaching, and replacing the capillary can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an ultrasonic wire bonder using a composite bending vibration system of the present invention and vibration modes of respective parts.

FIG. 2 is an example of a vibration trajectory at the tip of a composite bending vibrator showing the principle of the present invention.

FIG. 3 is a diagram showing a structure of attaching a capillary to a composite bending vibrator and a relative vibration velocity characteristic of the capillary protrusion.

[Explanation of symbols]

 Reference numerals 1 and 2 Driving longitudinal vibrator 3 Electrostrictive element 4 Electrode 5 Composite bending vibrator 6 Capillary 7 Wire through hole 8 Capillary fixing screw 9, 10 Vibration mode of longitudinal vibrators 1 and 2 11, 12 Combination bending vibrator Complex bending vibration mode

Claims (2)

[Claims] 1. A composite bending vibration system comprising two longitudinal vibration elements and a composite bending element orthogonally coupled to both of these elements, and a hole for inserting a wire in the center of the composite bending element. An ultrasonic wire bonder using a composite bending vibration system, wherein a wire bonding capillary is detachably attached to the tip of the hole. 2. The composite bending vibration system according to claim 1, wherein said capillary is detachable from a hole of said composite bending oscillator so that a length from a tip of said composite bending oscillator to a tip of said capillary is adjustable. Ultrasonic wire bonder using.