Bonding Actuator With 6-Axis VCM Alignment for Sub-Micron Mounting
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Solution Overview
Problem
Conventional high-precision chip bonding devices face challenges in maintaining precise alignment and parallelism due to thermal and mechanical stress, vibration, and pressure fluctuations, leading to errors in bonding precision, especially when requiring sub-micron or nanometer-level accuracy.
Innovation Solution
A mounting device with a bonding head and stage that uses a combination of air cylinder levitation, voice coil motors, and advanced encoder systems to adjust the position and parallelism of chips and wafers in six axial directions, including X, Y, Z, Tx, Ty, and Tz, allowing for non-contact movement and precise control of the bonding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a vertical two-visual field optical system is used for high-precision alignment, then bonding precision is improved, but the system deforms over time due to thermal/mechanical stress causing positioning errors
Solution Approach 1:
The patent replaces the conventional mechanical vertical two-visual field optical system with a laser interferometer-based measurement system. The laser interferometer uses optical interference patterns to measure positional deviations without mechanical contact, eliminating the thermal and mechanical stress-induced deformation problems of the optical system while maintaining high measurement precision.
Solution Approach 2:
The patent introduces a laser interferometer as an intermediary measurement device between the bonding head and the stage. This intermediary system measures the actual positions of the bonding head and stage with high precision and provides feedback signals to the control unit, enabling compensation for positioning errors without requiring the optical system to maintain perfect mechanical stability.
2Strength
If high temperature/high pressure is applied for direct metal bonding, then bonding strength is improved, but bonding precision deteriorates due to thermal deformation
Solution Approach 1:
The patent implements a closed-loop feedback control system where the laser interferometer continuously measures the actual positions of the bonding head and stage during the bonding process. The control unit receives these measurement signals and adjusts the driving commands to the bonding head and stage in real-time, compensating for thermal deformation and maintaining positioning precision even under high temperature and pressure bonding conditions.
Solution Approach 2:
The patent performs preliminary position measurement and compensation before the actual bonding process. The laser interferometer measures the initial positions of the bonding head and stage, and the control unit calculates compensation values based on these measurements. This preliminary action ensures that even if thermal deformation occurs during bonding, the initial alignment precision is maintained.
3Manufacturing precision
If a static pressure bearing is used to reduce contact friction, then motion precision is improved, but sub-micron shaking occurs due to vibration and pressure fluctuations
Solution Approach 1:
The patent uses the laser interferometer to continuously monitor the actual positions of the bonding head and stage, providing real-time feedback signals to the control unit. This feedback mechanism detects sub-micron shaking caused by vibration and pressure fluctuations in the static pressure bearing system, and the control unit adjusts the driving commands to compensate for these deviations, maintaining stable positioning.
Solution Approach 2:
The patent performs preliminary position measurement using the laser interferometer before bonding operations. By measuring the baseline positions of the bonding head and stage in advance, the system can detect and compensate for any sub-micron shaking or drift that occurs during the bonding process, ensuring position stability.
4Adaptability or versatility
If bonding head height is varied for chip recognition and bonding, then operational flexibility is improved, but errors occur in target coordinates due to movement and vibration
Solution Approach 1:
The patent implements a feedback control system where the laser interferometer continuously measures the actual Z-axis positions of the bonding head during height adjustment for chip recognition and bonding operations. The control unit receives these position signals and adjusts the driving commands to maintain accurate target coordinates, compensating for any positioning errors caused by movement or vibration during height changes.
Solution Approach 2:
The patent replaces conventional mechanical position sensing methods with a laser interferometer-based measurement system. The laser interferometer provides non-contact, high-precision measurement of the bonding head's Z-axis position during height adjustment, eliminating the positioning errors that would occur with mechanical sensors or encoders subjected to movement and vibration.
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 solution enables high-precision bonding by minimizing errors caused by thermal deformation, vibration, and pressure fluctuations, ensuring accurate alignment and parallelism, thereby achieving bonding precision of hundreds of nanometers or less.
Implementation Method 1
a slider (12) accommodated in the housing (11) in a non-contact state
Implementation Method 2
each of which has a coil and a yoke in a non-contact state, the coil being fixed to the housing and the yoke being fixed to the slider
Data Source
AI summary
Provided are mounting devices and mounting methods configured to realize high-precision mounting. A mounting device including a bonding actuator having a housing, a slider accommodated in the housing in a non-contact state and provided with a head, a coil and a yoke in a non-contact state, two voice coil motors (VCMs) driven in an X-axis direction, three VCMs driven in a Y-axis direction, and one VCM driven in a Z-axis direction may be provided. The coil may be fixed to the housing and the yoke may be fixed to the slider. The bonding actuator may perform bonding while adjusting a relative position and parallelism of a chip and a wafer, by driving the slider in six axial directions, which include the X-axis direction, the Y-axis direction, the Z-axis direction, a Tx direction, a Ty direction, and a Tz direction.