Mobile Electrostatic Carrier for Contamination-Free Wafer Singulation
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Solution Overview
Problem
Current semiconductor wafer singulation methods, such as diamond saw technology and dicing tapes, face challenges in efficiently and cost-effectively cutting semiconductors into individual dies without residue and contamination, lacking a highly yielding and contamination-free handling solution.
Innovation Solution
A mobile electrostatic carrier (MESC) is used to hold and release thin semiconductive substrates using electrostatic bonding, allowing for rigid and contamination-free handling during manufacturing processes like grinding and singulation, without the need for adhesives or mechanical clamping, utilizing electrostatic field generating circuits and a capacitance charging interface to adjust bonding strength and dielectric properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If diamond saw technology is used for singulation, then the wafer can be cut into individual dies, but the process involves contamination and is not cost effective
Solution Approach 1:
The patent replaces mechanical cutting systems (diamond saws) with an electrostatic bonding system. The MESC uses electrostatic fields to hold and release dies without mechanical contact, eliminating contamination from mechanical cutting processes and reducing costs by eliminating expensive diamond saw equipment and associated consumables.
Solution Approach 2:
The patent introduces an intermediary electrostatic bonding mechanism between the wafer and the carrier. The MESC acts as an intermediary that temporarily holds the wafer and then releases individual dies without direct mechanical contact, serving as a clean intermediary that transfers dies without contamination.
2Productivity
If dicing tapes are used to speed up throughput, then singulation becomes more cost effective, but dies are difficult to remove or have residue that is hard to clean
Solution Approach 1:
The patent changes the bonding parameter from permanent adhesive bonding (dicing tape) to controllable electrostatic bonding. The electrostatic bond strength can be dynamically adjusted by changing voltage parameters, allowing strong bonding during processing and easy release by discharging the electrostatic field, eliminating residue issues entirely.
Solution Approach 2:
The patent replaces mechanical adhesive bonding (dicing tape) with an electrostatic field-based bonding system. This substitution eliminates the need for adhesive materials that leave residue and make die removal difficult, while maintaining high throughput through efficient electrostatic release mechanisms.
3Object-affected harmful factors
If electrostatic bonding is used to hold thin substrates, then rigid contamination-free handling is achieved, but the system requires external power supply and vacuum supply
Solution Approach 1:
The patent extracts and eliminates the complex vacuum supply system from the electrostatic bonding apparatus. The MESC design integrates self-contained electrostatic field generating circuits that operate without external vacuum requirements, removing the harmful vacuum environment while maintaining contamination-free handling through controlled electrostatic fields alone.
Solution Approach 2:
The patent implements self-service electrostatic bonding where the MESC generates its own electrostatic fields through integrated circuits and capacitors. The system is self-sufficient, generating the necessary electrostatic fields internally without requiring external power supplies or vacuum systems, thereby reducing device complexity while maintaining clean handling.
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 MESC enables efficient and residue-free singulation of semiconductive wafers into individual dies, maintaining strong bonding during processing and easy release, enhancing throughput and reducing contamination risks, while accommodating various substrate sizes and materials.
Implementation Method 1
The MESC is an electrostatic temporary bond technology that provides a rigid contamination-free handling solution for fragile non-standard substrates and small devices without the need for fasteners or adhesives.
Implementation Method 2
The MESC is able to bond so strongly to a thin semiconductive substrate that the MESC can hold onto the thin semiconductive substrate during different manufacturing processes with large sheer forces such as grinding or singulation.
Data Source
AI summary
A mobile electrostatic carrier (MESC) provides a structural platform to temporarily bond a semiconductive wafer and can be used to transport the semiconductive wafer or be used to perform manufacturing processes on the semiconductive wafer. The MESC uses a plurality of electrostatic field generating (EFG) circuits to generate electrostatic fields across the MESC that allow the MESC to bond to compositional impurities within the semiconductive process. The MESC is particularly useful during singulation for a wafer fabrication process. The MESC holds the semiconductive wafer in a constant position as the semiconductive wafer is cut into a plurality of dies. Once the MESC is discharges its EFG circuits and consequently dissipates its bonding electrostatic fields, the plurality of dies can be easily and readily removed from the MESC.