Flip Chip Mounting via Dual-Head Segmentation and Calibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for mounting semiconductor chips as flip chips on substrates face challenges in achieving high placement precision and throughput simultaneously.
Innovation Solution
A method and apparatus that utilize a combination of cameras and transport systems to precisely position and mount flip chips on substrates, with a calibration phase to determine geometry data for converting pixel coordinates to machine coordinates, allowing simultaneous operation of transport and bonding heads for increased throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single head is used for both transport and bonding operations, then device complexity is reduced, but productivity decreases due to sequential operation
Solution Approach 1:
The apparatus is divided into two independent heads: a transport head for moving flip chips and a bonding head for mounting them on substrates. This segmentation allows parallel operation of transport and bonding functions, increasing productivity while maintaining manageable device complexity through modular design.
Solution Approach 2:
Each head (transport head and bonding head) is designed to perform multiple functions within its domain. The transport head handles chip retrieval, flipping, and positioning, while the bonding head performs precise placement and bonding operations. This multi-functionality maximizes the utility of each component without requiring excessive complexity.
2Manufacturing precision
If coordinate conversion is performed without calibration, then device complexity is reduced, but manufacturing precision deteriorates due to coordinate system misalignment
Solution Approach 1:
A calibration phase is performed before actual mounting operations to determine the geometric relationship between the transport head and bonding head coordinate systems. This preliminary action establishes accurate conversion parameters (rotation angle, translation vector, scaling factor) that ensure high placement precision during subsequent production runs.
Solution Approach 2:
The calibration process creates a mathematical model (coordinate conversion formula) that copies the geometric relationship between the two heads. This model allows the system to accurately translate positions from the transport head coordinate system to the bonding head coordinate system without requiring direct physical measurement during operation.
3Manufacturing precision
If the cavity is moved to different locations during the process, then ease of operation is improved, but manufacturing precision deteriorates due to position changes affecting coordinate accuracy
Solution Approach 1:
The cavity is kept in a fixed position throughout the mounting process, creating an equipotential reference frame. This fixed position ensures that the coordinate relationship between the transport head and bonding head remains constant, maintaining positioning accuracy. The fixed cavity acts as a stable reference point that eliminates errors introduced by position changes.
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
The method achieves high precision and high throughput in mounting semiconductor chips by ensuring accurate positioning and parallel operation of transport and bonding heads, optimizing wetting of chip bumps and reducing positioning errors due to temperature changes.
Implementation Method 1
depositing the flip chip 3 in the cavity 18, wherein its bumps 1 are immersed in the fluxing agent
Implementation Method 2
depositing the flip chip 3 in the cavity 18, wherein its bumps 1 are immersed in the fluxing agent
Data Source
AI summary
The invention relates to a method for mounting semiconductor chips provided with bumps as flip chips on substrate locations of a substrate. The method comprises the placing of a flip chip in a cavity arranged in a stationary manner where the bumps are wetted with a fluxing agent and the position of the flip chip is determined by means of a camera. The method further comprises the use of a transport head and a bonding head, which allow rapid and highly precise mounting.