Bonding Head Positioning via Optical Scale Correction
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Solution Overview
Problem
Conventional bonding apparatuses face challenges in maintaining positioning accuracy due to temperature changes, which affect the offset distance and result in insufficient precision during bonding operations.
Innovation Solution
A device comprising a moving body with a holding unit, position identifying means, a scale with graduations, and position detection units that correct the positioning of a first object relative to a second object by calculating and adjusting for thermal expansions, ensuring accurate alignment without the need for calibration of the offset distance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the bonding head is moved to a position of a reference member to calibrate offset amount, then positioning accuracy is improved, but the temperature of the bonding head changes and the offset distance changes, resulting in insufficient positioning accuracy
Solution Approach 1:
The patent replaces the mechanical calibration method (moving bonding head to reference member) with an optical measurement system. The position detection camera and scale system detect positions optically without requiring physical movement of the bonding head to calibration positions, thereby avoiding temperature changes from repeated mechanical movements while maintaining positioning accuracy.
Solution Approach 2:
The patent uses a position detection camera to create an optical copy/image of the position being measured. Instead of physically moving the bonding head to verify position, the system captures an image of the scale at the current position and processes this optical information to determine positioning accuracy, eliminating the need for disruptive mechanical calibration movements.
2Measurement precision
If the bonding head is moved repeatedly for calibration, then positioning accuracy is improved, but the time required for bonding operations increases
Solution Approach 1:
The system performs preliminary position detection using the camera and scale system before bonding operations begin. Once the initial position relationship is established and stored, no further calibration movements are needed during subsequent bonding operations, saving time while maintaining accuracy.
Solution Approach 2:
The position detection camera continuously monitors or repeatedly measures the position relationship between the bonding head and reference members during bonding operations. This continuous optical feedback allows the system to maintain positioning accuracy throughout the bonding process without interrupting the workflow for repeated calibration movements.
3Measurement precision
If the offset distance is calibrated during bonding operation, then positioning accuracy is improved, but the complexity of the bonding apparatus increases
Solution Approach 1:
The position detection camera serves multiple functions: it detects the position of reference members, measures the offset distance between the bonding head and reference member, and provides continuous position feedback during bonding operations. This multi-functionality reduces the need for separate calibration mechanisms, simplifying the overall apparatus while maintaining positioning accuracy.
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 improves the positioning accuracy of the first object in relation to the second object by dynamically adjusting for thermal changes, enhancing the precision and productivity of bonding operations without the requirement for frequent calibration.
Implementation Method 1
a first position detection unit which is attached to the moving body to correspond to the holding unit and detects a position of the holding unit on the basis of the graduations; a second position detection unit which is attached to the moving body with a predetermined interval from the first position detection unit to correspond to the position identifying means and detects a position of the graduation on the scale that corresponds to the identified position of the second object
Implementation Method 2
the position identifying means may be a camera that optically identifies the position of the second object
Data Source
AI summary
This mounting device (100) comprises: a base (10) that moves linearly in relation to a substrate (16); a bonding head (20) that is attached to the base (10); a camera (25) that is attached to the base (10) and identifies the position of the substrate (16); a linear scale (33) having a plurality of graduations along the movement direction; a bonding head-side encoder head (31); and a camera-side encoder head (32). A control unit (50) causes the base (10) to move to a position where the bonding head-side encoder head (31) detects the position of a graduation. Due to this configuration, positioning accuracy of a semiconductor die (15) in relation to the substrate (16) is improved.