Wire Bonder Transducer Mounting for Multi-Axis Scrubbing
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Solution Overview
Problem
Conventional wire bonders have limitations in cleaning the die pad surface during ball bonding due to a linear scrubbing motion and fixed ultrasonic frequency, which can compromise the quality and strength of the ball bond with the die pad surface.
Innovation Solution
An apparatus with a flexural structure and piezo-stack actuators is used to mount the transducer on a wire bonder, allowing for a multi-linear scrubbing motion and varying frequencies, enabling better cleaning and bonding energy distribution along different axes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a linear scrubbing motion is used during ball bonding, then the bonding device structure is simple, but the cleaning quality of the die pad surface is insufficient
Solution Approach 1:
The patent applies the dynamics principle by replacing the static linear scrubbing motion with a dynamic multi-linear scrubbing motion. The flexural structure enables the bonding tool tip to move in multiple linear directions (X, Y, and Z axes) during the bonding process, creating a more effective cleaning action on the die pad surface while maintaining a relatively simple overall device structure.
Solution Approach 2:
The patent implements the dimensionality change principle by adding movement in multiple spatial dimensions. Instead of restricting the scrubbing motion to a single linear path, the flexural structure allows the bonding tool tip to scrub across the die pad surface in multiple linear directions, effectively utilizing X, Y, and Z axes to improve cleaning coverage and quality.
2Strength
If a fixed ultrasonic frequency is used during bonding, then the transducer operation is simple, but the bond strength between ball bond and die pad surface is compromised
Solution Approach 1:
The patent applies the dynamics principle by enabling the transducer to operate at variable frequencies rather than a fixed frequency. The system can dynamically adjust the ultrasonic frequency and combine it with multi-linear mechanical motion to optimize bonding conditions, resulting in improved bond strength between the ball bond and die pad surface.
Solution Approach 2:
The patent implements the parameter changes principle by allowing variation in the ultrasonic frequency parameter during the bonding process. Instead of operating at a single fixed frequency, the system can change the frequency parameter to match different bonding requirements and material properties, thereby optimizing the bond strength while managing transducer operation complexity.
3Manufacturing precision
If a single linear scrubbing path is used, then the device control is simple, but the cleaning effectiveness on the die pad surface is insufficient
Solution Approach 1:
The patent applies the dynamics principle by transforming the static single linear scrubbing path into a dynamic multi-linear scrubbing path. The flexural structure enables automatic multi-axis movement of the bonding tool tip, improving cleaning effectiveness across the die pad surface while the system manages the operational complexity through integrated control mechanisms.
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
This approach improves the quality of the ball bonding process by ensuring a thorough cleaning of the die pad surface and enhances the bond strength between the ball bond and the die pad surface.
Implementation Method 1
the at least one actuator may be a piezo-stack actuator that is configured to be actuated by an electrical source oscillating at a sub-ultrasonic frequency
Implementation Method 2
an ultrasonic transducer of a wire bonder is mechanically driven to move the bonding tool tip in a scrubbing motion during ball bonding to clean a die pad surface of a semiconductor die. The ultrasonic transducer also provides ultrasonic bonding energy during ball bonding to cause adhesion of a ball bond of the bonding wire with the die pad surface
Data Source
AI summary
Disclosed is an apparatus for mounting a transducer to a bond head of a wire bonder. In particular, the bond head of the wire bonder is operative to mechanically drive the transducer when forming electrical interconnections between separate locations within a semiconductor package. Specifically, the apparatus comprises: i) a flexural structure having a connector for connecting to the transducer, the flexural structure being configured to bend; and ii) at least one actuator attached to the flexural structure, the at least one actuator being operative to bend the flexural structure to thereby cause a displacement of the transducer connected thereto via the connector.


