CN-122028764-A - Method and system for forming three-dimensional space vertical wire arc of wire bonding machine

CN122028764ACN 122028764 ACN122028764 ACN 122028764ACN-122028764-A

Abstract

The application discloses a method and a system for forming a three-dimensional space vertical wire arc of a wire bonding machine, and relates to the technical field of semiconductor packaging; the method comprises the steps of moving a riving knife to a firing height to execute firing balls, opening a wire clamp after welding of a first welding spot is completed, lifting the riving knife to a length required by a preset vertical wire arc, closing the wire clamp by a bunting head control wire clamp, moving the wire clamp to a preset notch preparation position outside a welding pad, controlling the tip of the riving knife to press down a wire rod to form a notch, adopting a dynamic multi-axis track planning algorithm, controlling the riving knife to return to the position right above the first welding spot along an optimized track and reserving the wire tail height, closing the wire clamp by the bunting head control wire clamp, controlling the riving knife to directionally lift along a Z axis to enable the wire rod to stretch and break at the notch to form a three-dimensional vertical wire arc with a vertical initial section and the preset wire tail height at the tail end. According to the method, no external hardware module is required to be introduced, and the three-dimensional space high-reliability wire arc forming is realized in the existing equipment frame by cooperatively regulating and controlling the mechanical action of the chopper and the multi-axis motion track.

Inventors

HE YUNBO
Ji Haizhong
YAN YIJUN
LI HAOLIN
PENG PEIXIN

Assignees

广东阿达半导体设备股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (10)

1. The three-dimensional space vertical wire arc forming method of the wire bonding machine is characterized by comprising the following steps of: the chopper moves to the firing height, the firing ball is carried out, and the first welding spot welding is completed; after the first welding spot is welded, opening the wire clamp, and lifting the chopper to a length required by a preset vertical wire arc; The bonding head control wire clamp is closed, the riving knife moves to a preset notch preparation position outside the bonding pad, and the tip of the riving knife is controlled to press down the wire to form a notch; a dynamic multi-axis track planning algorithm is adopted, and the riving knife is controlled to return to the position right above the first welding point along the optimized track and the tail height is reserved; The bonding head controls the wire clamp to be closed, and controls the chopper to be lifted along the Z axis in an oriented way, so that the wire rod is stretched and broken at the notch to form a three-dimensional space vertical wire arc with a vertical starting section and a preset wire tail height at the tail end.
2. The method of claim 1, wherein the step of controlling the riving knife tip to press down the wire to form the notch comprises: controlling the riving knife to quickly descend to a preset height; and switching to a force control mode, and controlling the chopper to apply vertical pressure to the wire rod to slowly press down, wherein the preset pressure is between the yield strength and the tensile strength of the wire rod.
3. The method of claim 1, wherein the step of controlling the riving knife to return to directly above the first welding point along the optimized trajectory by using a dynamic multi-axis trajectory planning algorithm comprises: Constructing equidistant three-dimensional space coordinate points between the notch preparation position and the first welding spot coordinates; And constructing a cubic polynomial curve between every two adjacent coordinate points, and enabling adjacent curve segments to have continuous second derivatives at nodes so as to form a smooth three-dimensional spline curve as the optimized track.
4. The method of claim 1, wherein the step of moving the riving knife to the firing height, firing the ball and completing the first spot weld comprises: Controlling the chopper to lift a preset tail height and then to descend to the height of the firing ball; exciting an electric arc, and ablating and melting the tail end of the wire rod into a metal ball; and driving the chopper to press down and applying ultrasonic vibration to weld the metal ball on the bonding pad to form a first welding spot.
5. The method of three-dimensional space-wise vertical wire arc formation of a wire bonding machine according to claim 4 wherein in said step of igniting an arc, the arc energy is determined by the formula: ; Wherein, the In order for the breakdown voltage to be high, In order to strike a fire of the current, In order to achieve a time for the fire to take place, Is the arc energy.
6. The method of claim 1, wherein the moving the riving knife to the preparation position of the notch outside the bonding pad comprises controlling the riving knife to move cooperatively and vertically while the moving platform drives the wire arc to move horizontally.
7. The wire bonding machine three-dimensional space vertical wire bow forming method of claim 6 wherein the coordinated vertical motion comprises a high-speed approximation stage and a precision force control stage; in the high-speed approximation stage, the system is in closed-loop position control, and the motor outputs force Is determined by the following formula: , Wherein, the In the event of a position command, In order to be able to achieve a speed, In order for the acceleration to be a function of the acceleration, In order to feed back the position in real time, For the speed of the bonding head, the bonding speed is equal to the bonding speed, In the proportion of the PID, For the differential gain of the PID, For the acceleration feed-forward gain, Is the speed feed forward gain.
8. The method of claim 1, wherein the step of forming the three-dimensional vertical wire loop having a vertical start section and a predetermined tail height at the end comprises the steps of: when the chopper returns to the position right above the first welding point, controlling the chopper to be lifted to the preset tail height along the Z axis; Closing a control wire clamp; The riving knife is controlled to be lifted upwards along the Z axis, so that the wire is broken at the notch.
9. The method of claim 1, wherein after the step of opening the wire clamp after the first welding spot is completed and the riving knife is lifted to a predetermined length required for the vertical wire arc, further comprising controlling the wire clamp to be closed to fix the wire.
10. A wire bonding machine three-dimensional space vertical wire bow forming system employing the wire bonding machine three-dimensional space vertical wire bow forming method of any one of claims 1-9, comprising: The motion control card is used for executing a multi-axis track planning algorithm, a dynamics optimization algorithm and process logic coordination; The ignition module is used for forming a molten ball at the end part of the wire rod before welding; The device comprises a bonding head and a motion platform module, wherein the bonding head is used for driving a riving knife to vertically feed, applying ultrasonic energy and controlling the opening and closing of a wire clamp, and the motion platform module is used for driving the bonding head or a workbench to move in a two-dimensional plane; the chopper is used for applying downward pressure to the wire so as to form a notch, and the wire clamp is used for clamping the wire so as to assist in breaking.

Description

Method and system for forming three-dimensional space vertical wire arc of wire bonding machine Technical Field The application relates to the technical field of semiconductor packaging, in particular to a method and a system for forming a three-dimensional space vertical wire arc of a wire bonding machine, which are suitable for a wire bonding process in advanced packaging scenes such as three-dimensional stacked packaging, heterogeneous integration, silicon through hole auxiliary interconnection and the like. Background The wire bonding machine is used as high-end semiconductor packaging equipment integrating multidisciplinary front-end technologies such as precision machinery, servo control, machine vision, ultrasonic energy and the like, and a mature application system is formed in the traditional two-dimensional plane packaging technology. As chip feature sizes continue to shrink, the number of interconnects that can be carried by two-dimensional planar bonding has approached theoretical saturation, limited by the limits of wiring density in the physical plane. To break through this bottleneck, semiconductor packaging technology is evolving towards three-dimensional stacked architectures to achieve higher functional density and performance integration. However, conventional wire-arc morphology based on planar geometric models is difficult to adapt to three-dimensional packaging structures with vertical dimensional interconnection requirements. In the conventional two-dimensional packaging process, the wire loops are generally in an arched or trapezoidal structure with a larger horizontal span, and the forming process mainly depends on the motion track control of the riving knife in a two-dimensional plane. However, in advanced packaging scenarios such as high-layer chip stacking, heterogeneous integration, and through-silicon via auxiliary interconnection, there is an urgent need for three-dimensional space wire-bonding with high vertical segments, low horizontal spans, and excellent mechanical stability. In the prior art, in order to realize the vertical wire-arc shape, an additional auxiliary device is usually required to be introduced or the equipment is subjected to complex transformation, so that the equipment cost and the process complexity are increased, and the process compatibility and the production line adaptability are reduced. Therefore, how to realize reliable formation of the vertical wire arcs in the three-dimensional space through process optimization and algorithm upgrading in the framework of the existing wire bonding machine equipment becomes a technical problem to be solved in the field. Disclosure of Invention Aiming at the technical problems that the traditional wire arc shape is limited by two-dimensional geometric configuration and is difficult to adapt to the requirement of three-dimensional stacked packaging on a vertical interconnection space structure in the bonding process of the existing wire bonding machine, the application provides a method and a system for forming the three-dimensional space vertical wire arc of the wire bonding machine. The technical proposal is as follows: In one aspect, a method for forming a three-dimensional vertical wire loop of a wire bonding machine is provided, including: the chopper moves to the firing height, the firing ball is carried out, and the first welding spot welding is completed; after the first welding spot is welded, opening the wire clamp, and lifting the chopper to a length required by a preset vertical wire arc; The bonding head control wire clamp is closed, the riving knife moves to a preset notch preparation position outside the bonding pad, and the tip of the riving knife is controlled to press down the wire to form a notch; a dynamic multi-axis track planning algorithm is adopted, and the riving knife is controlled to return to the position right above the first welding point along the optimized track and the tail height is reserved; The bonding head controls the wire clamp to be closed, and controls the chopper to be lifted along the Z axis in an oriented way, so that the wire rod is stretched and broken at the notch to form a three-dimensional space vertical wire arc with a vertical starting section and a preset wire tail height at the tail end. Preferably, the step of controlling the riving knife tip to press down the wire to form the notch includes: controlling the riving knife to quickly descend to a preset height; And switching to a force control mode, and controlling the riving knife to apply vertical pressure to the wire rod to slowly press down, wherein the preset pressure is between the yield strength and the tensile strength of the wire rod. Preferably, the step of controlling the riving knife to return to the position right above the first welding spot along the optimized track by adopting a dynamic multi-axis track planning algorithm includes: Constructing equidistant three-dimensional space coordinate points b