Dual-Focus Mounting Head Alignment for Face-Up Chip Placement
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Solution Overview
Problem
In face-up mounting of semiconductor chip components, achieving accurate and rapid positioning without significant cost increase is challenging due to issues with optical path lengths, focal depth, and complex reflecting optical systems, which affect mounting accuracy and productivity.
Innovation Solution
A mounting device with a recognition mechanism that includes independently focused chip and substrate recognition sensors on a common optical axis path, allowing simultaneous recognition and calculation of misalignment between chip and substrate recognition marks, and automatic calibration to ensure accurate positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an upper and lower two-field camera is used to observe recognition marks in face-up mounting, then positioning accuracy can be achieved, but device complexity and cost increase significantly
Solution Approach 1:
The patent divides the optical observation system into two independent focused sensors: one sensor focuses on the chip recognition mark while the other sensor focuses on the substrate recognition mark. This segmentation allows each sensor to be optimized for its specific focal plane, eliminating the need for complex reflecting optical systems while maintaining positioning accuracy.
2Stability of the object's composition
If the chip component is held in close contact with the mounting head for face-up mounting, then mounting stability is improved, but the ability to accurately ascertain the position of the chip recognition mark deteriorates
Solution Approach 1:
The patent introduces an intermediary optical system that uses a transparent or translucent member to allow optical passage between the chip recognition mark and the focused sensor. This intermediary enables the sensor to detect the recognition mark position through the mounting head structure without requiring the chip to be in close contact with the mounting head, thus maintaining both mounting stability and detection accuracy.
3Measurement precision
If different focal positions are used for chip and substrate recognition sensors, then simultaneous recognition accuracy is improved, but optical path complexity increases
Solution Approach 1:
The patent segments the optical detection function into two independent focused sensors with different focal positions. One sensor is focused on the chip recognition mark plane while the other is focused on the substrate recognition mark plane. This segmentation eliminates the need for complex adjustable optical paths, as each sensor has a fixed focal position optimized for its specific target.
4Productivity
If rapid positioning is achieved through simplified optical systems, then productivity increases, but positioning accuracy may deteriorate
Solution Approach 1:
The patent performs preliminary focusing setup during system configuration, where the two sensors are pre-adjusted to focus on their respective planes (chip recognition mark and substrate recognition mark). This preliminary action eliminates the need for real-time optical adjustment during mounting operations, enabling rapid positioning while maintaining high accuracy through the pre-optimized optical paths.
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
Enables rapid and accurate positioning of chip components on substrates with minimal cost increase, maintaining high accuracy and productivity while simplifying the optical system.
Implementation Method 1
a first focused sensor configured to recognize the chip recognition mark and a second focused sensor configured to recognize the substrate recognition mark, the first focused sensor and the second focused sensor being independently provided so that focal positions thereof are different via a common optical axis path
Data Source
AI summary
A mounting device comprises a recognition mechanism and a control unit. The recognition mechanism recognizes a chip recognition mark and a substrate recognition mark through a mounting head and from above the mounting head and is movable in an in-plane direction of a substrate surface of a substrate. The control unit is connected to the recognition mechanism, calculates an amount of misalignment between a chip component and the substrate from position information about the chip recognition mark and the substrate recognition mark obtained from the recognition mechanism, and performs positioning by driving the mounting head and/or the substrate stage according to the amount of misalignment. The recognition mechanism has a chip recognition sensor for recognizing the chip recognition mark and a substrate recognition sensor for recognizing the substrate recognition mark provided independently so that focal positions thereof are different via a common optical axis path.