3D Printed Polishing Pad IPN Material Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional polishing pad materials and manufacturing methods lack precise control over bulk properties such as storage modulus and loss modulus, leading to polishing non-uniformities and unpredictable performance during chemical mechanical polishing (CMP) processes.
Innovation Solution
The use of an interpenetrating polymer network (IPN) formed by blending cationically and free-radically polymerized materials, with specific ratios of photoinitiators, to create polishing pads via 3D printing, allowing for customizable properties and precise control of features like the window region for endpoint determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional polishing pad materials and manufacturing methods are used, then manufacturing simplicity is maintained, but fine control of bulk pad properties such as storage modulus and loss modulus is limited
Solution Approach 1:
The patent uses an interpenetrating polymer network (IPN) composite material system combining cationically polymerized materials and free-radically polymerized materials. This composite approach enables fine control of bulk pad properties including storage modulus and loss modulus by adjusting the ratio of different polymer materials, while the materials are processed through a unified 3D printing manufacturing method.
Solution Approach 2:
The patent controls bulk pad properties by changing the compositional parameters of the IPN system, specifically the ratio of cationically polymerized material to free-radically polymerized material. By adjusting these material parameters in the precursor blend, the storage modulus and loss modulus can be precisely controlled to achieve desired polishing performance.
2Reliability
If conventional polishing pads are used, then manufacturing process is simple, but polishing uniformity across substrate is poor
Solution Approach 1:
The patent applies local quality by using 3D printing to create region-specific properties within the polishing pad. Different nozzles deposit different IPN blend compositions in different regions (polishing surface, body, backing, window region), enabling each region to have optimized properties for its specific function, thereby achieving superior polishing uniformity across the substrate.
Solution Approach 2:
The patent segments the polishing pad into distinct functional regions (polishing surface, body, backing layer, window region) that can be manufactured with different material properties. The 3D printing process allows independent control of material composition in each segment, enabling precise optimization of polishing uniformity while maintaining manufacturing efficiency.
3Reliability
If standard polyurethane polishing pads are used, then manufacturing is straightforward, but performance predictability is poor
Solution Approach 1:
The patent achieves performance predictability by systematically controlling the compositional parameters of the IPN system. The ratio of cationically polymerized material to free-radically polymerized material is precisely adjusted to control storage modulus and loss modulus, providing predictable polishing performance. The photoinitiator ratios are also controlled to ensure consistent photopolymerization behavior.
Solution Approach 2:
The IPN composite material system provides predictable performance through the synergistic combination of cationically and free-radically polymerized materials. Each polymer network contributes specific mechanical and rheological properties, and their interpenetrating structure creates a predictable, stable material system that maintains desired properties over wide temperature ranges.
4Manufacturing precision
If 3D printing with IPN blends is used, then fine control of material properties is achieved, but manufacturing complexity increases
Solution Approach 1:
The 3D printing process is segmented into distinct functional zones (polishing surface, body, backing, window region) with dedicated nozzle configurations. Each nozzle is optimized for specific material deposition requirements, allowing fine control of modulus and hardness in each region while managing overall process complexity through modular design.
Solution Approach 2:
The patent controls material properties by adjusting the compositional parameters of the IPN precursor blends and photoinitiator ratios before printing. This approach enables fine control of modulus and hardness through material formulation rather than complex printing process parameters, simplifying the manufacturing process while maintaining high precision.
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 approach enables improved polishing uniformity at both microscopic and macroscopic levels, maintaining consistent pad performance over a wide temperature range and extending pad lifetime through precise control of mechanical properties and feature geometry.
Implementation Method 1
A first amount of a mixture of a free radical photoinitiator and a cationic photoinitiator is blended with the precursor blend to form a polishing pad blend... The raw polishing pad is irradiated to initiate free radical photopolymerization of the free radically polymerized material and cationic photopolymerization of the cationically polymerized material
Data Source
AI summary
A polishing pad for a semiconductor fabrication operation includes a polishing region and a window region, wherein both regions are made of an interpenetrating polymer network formed from a free-radically polymerized material and a cationically polymerized material.