Bonding Stage Rotation Locking for Substrate Positioning
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Solution Overview
Problem
Existing wire bonding apparatuses face challenges in accurately positioning the bonding stage due to weight-related stiffness issues and vibration, which affects bonding speed and precision, especially when handling substrates of varying thickness and size, and require frequent re-heating, leading to decreased productivity and increased risk of substrate cracking.
Innovation Solution
A bonding method utilizing a rotation drive mechanism with air-pressure lock sections to securely lock the bonding stage along multiple axes, combined with an X-axis, Y-axis, and Z-axis driving mechanisms, allows for precise positioning and handling of substrates with orientation flats or notches on carrier tapes, enabling efficient bonding across a wide area without the need for frequent re-heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a heavy bonding stage is rotated by a rotation drive mechanism, then bonding can be performed on a wider substrate area, but the stiffness of the bonding stage decreases and vibration occurs during bonding
Solution Approach 1:
The bonding stage is divided into a fixed portion and a movable portion that can be rotated independently. The fixed portion maintains stiffness and stability, while the movable portion enables rotation for wider substrate coverage without compromising overall structural rigidity.
Solution Approach 2:
A rotation drive mechanism with lock sections acts as an intermediary between the bonding stage and the rotation motion. The lock sections engage with rotation stoppers to provide precise positioning and maintain stability during bonding while enabling rotation when needed.
2Area of stationary object
If a heavy bonding stage is rotated by a rotation drive mechanism, then bonding can be performed on a wider substrate area, but vibration is likely to occur during bonding
Solution Approach 1:
The lock sections engage with the rotation stoppers before bonding begins to pre-establish a stable, vibration-free configuration. This preliminary locking action prevents vibration during the bonding process by securing the bonding stage in the desired position.
Solution Approach 2:
The rotation drive mechanism with lock sections serves as an intermediary that isolates the bonding stage from vibration. The locking mechanism absorbs and dampens vibrational forces, preventing them from affecting the bonding process while still enabling rotation for wider substrate coverage.
3Area of stationary object
If the substrate is displaced to the inversion unit for inversion, then bonding can be performed on wider substrate areas, but the temperature of the substrate decreases and re-preheating is needed
Solution Approach 1:
The inversion function is extracted from a separate inversion unit and integrated directly into the bonding stage. This allows the bonding stage itself to perform the inversion operation, eliminating the need to transport the substrate to a separate unit and maintaining temperature continuity.
Solution Approach 2:
The inversion capability is merged with the bonding stage by incorporating rotation drive mechanisms and lock sections directly into the stage structure. This integration combines the bonding and inversion functions in a single unit, eliminating temperature loss and improving productivity.
4Area of stationary object
If the substrate is displaced to the inversion unit for inversion, then bonding can be performed on wider substrate areas, but the risk of cracking in the substrate increases
Solution Approach 1:
The inversion operation is extracted from a separate unit and performed in-place on the bonding stage, eliminating the displacement step that causes temperature decrease and thermal stress. This maintains substrate integrity by avoiding the cracking risk associated with temperature fluctuations during inversion.
5Measurement precision
If an electromagnet is used in the brake unit, then the rotary shaft can be fixed at the predetermined position, but the magnetic force may adversely affect semiconductor elements
Solution Approach 1:
The electromagnetic braking system is replaced with a mechanical locking system consisting of lock sections and rotation stoppers. The lock sections engage with the rotation stoppers to fix the bonding stage at predetermined positions without using magnetic fields, thereby eliminating adverse effects on semiconductor elements while maintaining positioning accuracy.
Solution Approach 2:
The locking mechanism uses pneumatic or mechanical actuation instead of electromagnetic forces. The lock sections are actuated by non-magnetic means to engage with the rotation stoppers, providing precise positioning without exposing semiconductor elements to harmful magnetic fields.
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 ensures accurate and stable positioning of the bonding stage, enhances bonding speed, and increases productivity by reducing vibration and the need for re-heating, while accommodating substrates of different sizes and thicknesses without adverse effects on semiconductor elements.
Implementation Method 1
air pressure lock sections to lock the bonding stage along multiple axes
Data Source
AI summary
There is provided a bonding method capable of accurately positioning a bonding stage. According to an aspect of the present invention, a bonding method using a bonding apparatus including a rotation drive mechanism for rotating a bonding stage 1 about a θ-axis includes the steps of: (e) locking the bonding stage with respect to the θ-axis, and bonding a wire or bump onto a certain area of a substrate held on the bonding stage; (f) unlocking the bonding stage with respect to the θ-axis, and rotating the bonding stage about the θ-axis with the rotation drive mechanism; and (g) locking the bonding stage with respect to the θ-axis, and bonding a wire or bump onto a remaining region of the substrate.