Wire Biasing Tool Linkage for Low Heavy-Wire Loop Control
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Solution Overview
Problem
Existing wire bonding systems face challenges in accurately forming low wire loops with heavy bonding wires, such as aluminum, which are necessary for high power electronic packages to minimize package height and ensure consistency in wire loop shapes.
Innovation Solution
A wire bonding system incorporating a wire biasing tool with a rotary actuator and four-bar linkage mechanism to apply a biasing force on the bonding wire, enhancing accuracy and consistency of wire loop formation by controlling the biasing force and travel path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a wedge wire bonding machine is used to bond heavy wires, then the bonding capability for high power electronic packages is achieved, but the wire loop height control precision deteriorates
Solution Approach 1:
The wire bonding system is segmented into distinct functional modules: a bonding tool for creating wire bonds, a wire guide for positioning the wire, and a wire biasing tool for applying controlled force. This segmentation allows each module to be optimized independently, with the biasing tool specifically designed to control wire loop height while the bonding tool maintains bonding capability for heavy wires.
Solution Approach 2:
A wire biasing tool is introduced as an intermediary component between the wire guide and the bonding tool. This biasing tool applies a controlled biasing force to the wire, acting as a mediator that enables precise wire loop height control without interfering with the bonding process. The biasing force compensates for wire flexibility issues, ensuring consistent loop formation even with heavy wires.
2Power
If heavy bonding wires are used for high power electronic packages, then the current conduction capability is improved, but the wire loop formation accuracy deteriorates
Solution Approach 1:
The wire biasing tool applies a preliminary biasing force to the wire before the bonding process occurs. This preliminary action pre-positions the wire and controls its flexibility, ensuring that when the bonding tool creates the wire loop, the loop height is precisely controlled. The biasing force is applied in advance to counteract the natural flexibility of heavy wires, enabling accurate loop formation.
Solution Approach 2:
The system dynamically adjusts the biasing force parameter applied to the wire. By changing the magnitude and direction of the biasing force, the system optimizes wire loop formation for different wire types and bonding conditions. This parameter control enables consistent loop height accuracy while maintaining the ability to bond heavy wires with high current conduction capability.
3Length of stationary object
If the wire loop height is reduced to minimize package height, then the assembled package size is reduced, but the consistency of wire loop shapes deteriorates
Solution Approach 1:
The wire biasing tool incorporates feedback control mechanisms that monitor wire loop formation in real-time. Based on this feedback, the biasing force is dynamically adjusted to maintain consistent loop shapes at the target low height. The system detects variations in wire position and loop formation, then compensates by modifying the biasing force, ensuring repeatable and consistent wire loop geometry across multiple bonds.
Solution Approach 2:
The biasing tool employs dynamic control of the wire biasing force during the bonding process. Rather than using a static fixed force, the system dynamically adjusts the biasing force magnitude and direction based on real-time wire position and loop formation progress. This dynamic control enables the system to achieve consistent low wire loop heights while maintaining uniform loop shapes, as the biasing force adapts to compensate for variations in wire properties and bonding conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system achieves more precise and consistent formation of low wire loops, reducing the height of assembled electronic packages and improving the repeatability of wire bonding operations.
Implementation Method 1
a rotary actuator operatively connected to the wire biasing tool by a linkage mechanism, the rotary actuator being operable to move the wire biasing tool along a predetermined travel path to apply a biasing force onto a length of bonding wire
Implementation Method 2
the bonding process may involve the application of force and ultrasonic energy at a tip of the wedge tool to form an intermetallic connection between the bond pad of a semiconductor die or a lead and the bonding wire
Data Source
AI summary
A wire bonding system has a bonding tool and a wire guide for guiding a bonding wire to a tip of the bonding tool for conducting wire bonding operations. A wire biasing tool is located adjacent to the wire guide, and a rotary actuator is operatively connected to the wire biasing tool by a linkage mechanism. The rotary actuator is operable to move the wire biasing tool along a predetermined travel path to apply a biasing force onto a length of bonding wire extending from the tip of the bonding tool.