Layered Body Sintering with Bimodal Powder Size Control
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Solution Overview
Problem
Existing spark plasma sintering (SPS) methods struggle to produce large-scale layered bodies with diameters of at least 200 mm, which are required for high-quality components in the semiconductor manufacturing industry, and face challenges in achieving uniform density, strength, scratch resistance, etch resistance, and reduced porosity.
Innovation Solution
A process involving a mixture of first and further constituent powders with specific particle size distributions, subjected to heat and pressure within a die with carbon walls, to form a layered body with controlled particle size distribution, resulting in improved properties and reduced defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If conventional spark plasma sintering methods are used, then small-scale parts up to around 150 mm can be produced, but large-scale layered bodies with diameter of at least 200 mm cannot be produced
Solution Approach 1:
The patent applies parameter changes by optimizing the particle size distribution of the powder mixture, specifically using a bimodal distribution with volume fractions of fine particles (0.5-5 μm) and coarse particles (5-20 μm) in specific ratios. This parameter optimization enables successful sintering of large-scale layered bodies with diameter ≥200 mm while maintaining quality consistency and uniform density distribution.
Solution Approach 2:
The patent uses composite powder materials consisting of multiple constituents (e.g., Al2O3, SiC, B4C) with different particle sizes and properties. This composite approach allows the material to achieve both large scale and structural uniformity, as the different particle sizes fill voids and create a more homogeneous green compact that sinters uniformly across large dimensions.
2Length of stationary object
If conventional sintering methods are used, then large-scale layered bodies can be produced, but uniform density distribution cannot be achieved
Solution Approach 1:
The patent changes the particle size distribution parameters to a bimodal distribution with specific volume fractions: fine particles (0.5-5 μm) at 30-70 vol% and coarse particles (5-20 μm) at 30-70 vol%. This parameter optimization ensures uniform packing density in the green compact, which translates to uniform density distribution in the final sintered product, even at large scales of 200 mm diameter.
Solution Approach 2:
The patent applies local quality by having different particle sizes in specific regions of the powder mixture. The fine particles fill the interstices between coarse particles, creating locally optimized packing arrangements throughout the entire volume. This local optimization of particle packing ensures uniform density distribution across the entire large-scale layered body.
3Length of stationary object
If conventional sintering methods are used, then large-scale layered bodies can be produced, but porosity cannot be reduced
Solution Approach 1:
The patent optimizes the particle size distribution parameters to minimize void spaces. The bimodal distribution with fine particles (0.5-5 μm) filling the gaps between coarse particles (5-20 μm) creates a densely packed green compact with minimal initial porosity. This parameter optimization, combined with controlled sintering, achieves large-scale production with reduced porosity.
4Productivity
If conventional sintering methods are used, then production can proceed, but strength and scratch resistance are insufficient
Solution Approach 1:
The patent employs composite materials comprising multiple constituents such as Al2O3, SiC, and B4C in specific ratios. This composite structure provides both production feasibility and enhanced mechanical properties. The different materials contribute to overall strength, scratch resistance, and structural integrity while maintaining manufacturability of large-scale layered bodies.
Solution Approach 2:
The patent optimizes the particle size distribution parameters (bimodal distribution with specific volume fractions) to enhance mechanical strength. The fine particles (0.5-5 μm) provide matrix continuity and bind the coarser particles, while the coarse particles (5-20 μm) provide structural framework. This parameter optimization achieves both production capability and improved mechanical properties including strength and scratch resistance.
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 process enables the production of large-scale layered bodies with enhanced strength, etch resistance, and reduced porosity, achieving uniform density and minimizing defects, suitable for semiconductor manufacturing applications.
Implementation Method 1
heating is achieved using an electric current
Implementation Method 2
the heat is generated by an electrical voltage applied across the die, the interior volume, or both
Data Source
AI summary
One aspect is a process for producing a layered body. A first powder is introduced into an interior volume to obtain a first powder layer. The interior volume has a cross-sectional width of at least 200 mm, and is bordered by a die of carbon. The first powder is a mixture comprising a first constituent powder and a further constituent powder of different chemical compositions. The first powder layer is subjected to a heat, generated by a voltage, and to a pressure to obtain the layered body. The further constituent powder has a particle size distribution D=q(χ) of volume density q over particle size χ, such that D has a first local maximum α at particle size χα with volume density qα, D has a second local maximum β at particle size χβ with volume density qβ, χα>χβ, and qα/qβ is at least 1.