Large Ceramic Co-Fired Articles via Segmented Dry Pressing
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Solution Overview
Problem
Current methods for manufacturing large ceramic devices, such as wafer heating and electrostatic chuck apparatus, face challenges in achieving precise dimensional tolerances, uniform shrinkage, and high temperature resistance due to limitations in existing high temperature co-fired ceramic (HTCC) processing techniques, particularly with roll compaction methods which result in non-uniform shrinkage and difficulty in producing thick, large tapes.
Innovation Solution
The method involves forming sheets by dry pressing ceramic powders to achieve precise thickness and density, assembling patterned green compacts, and isostatically pressing them to create a laminated assembly that is then fired, allowing for seamless bonding and uniform shrinkage, enabling the production of large and thick multilayer ceramic devices with embedded conductors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If roll compaction method is used to form ceramic tapes, then large size and thick sections can be achieved, but non-uniform shrinkage and poor dimensional control occur
Solution Approach 1:
The ceramic device is divided into multiple thin green sheets that are stacked and co-fired together. Each thin sheet maintains uniform dimensions and shrinkage characteristics, while the stacked assembly achieves the required large size and thick section. This segmentation approach eliminates the non-uniform shrinkage problem inherent in roll compaction of thick tapes.
Solution Approach 2:
Instead of forming thickness in the vertical dimension through roll compaction (which causes non-uniform shrinkage), the invention achieves thick sections by stacking multiple thin sheets in the vertical dimension. Each sheet is formed with precise dimensional control, and the stacking process maintains uniform shrinkage across all sheets during co-firing.
2Reliability
If ceramic insulating material is made thicker to prevent fracture during thermal cycling, then thermal expansion stress is reduced, but manufacturing complexity and cost increase
Solution Approach 1:
The thick ceramic structure is segmented into multiple thin green sheets stacked together. Each thin sheet undergoes uniform shrinkage during co-firing, resulting in a dense, reliable final product that resists thermal cycling stress. This approach achieves the required thickness for thermal reliability without the manufacturing complexities of forming and handling single thick tapes.
Solution Approach 2:
Multiple thin green sheets are merged through co-firing to form a unified thick ceramic structure. The merging process creates strong bonds between sheets while maintaining uniform dimensional properties throughout the assembled thickness, achieving thermal reliability without increased manufacturing complexity.
3Temperature
If HTCC processing is used to produce large ceramic devices, then high temperature resistance is achieved, but precise dimensional tolerances and uniform shrinkage are difficult to obtain
Solution Approach 1:
The large ceramic device is segmented into multiple thin green sheets, each with precisely controlled dimensions. During HTCC processing, each thin sheet shrinks uniformly, and the stacked assembly maintains dimensional tolerance. This segmentation approach enables high temperature resistance through HTCC processing while achieving precise dimensional tolerances that would be impossible with single thick tapes.
4Ease of manufacture
If conventional HTCC methods are used, then ceramic devices can be manufactured, but production of large and thick tapes is difficult and costly
Solution Approach 1:
Instead of attempting to form large and thick tapes directly (which is difficult and costly), the invention segments the final product into multiple thin green sheets that are easily manufactured and stacked. This approach makes production of large and thick ceramic devices straightforward and cost-effective while maintaining ease of manufacture through conventional HTCC processing.
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 the production of large, high-temperature co-fired ceramic articles with uniform shrinkage and precise dimensional control, suitable for applications like electrostatic chucks and heaters, capable of handling increased wafer sizes and high-temperature requirements, while reducing manufacturing costs and complexity.
Implementation Method 1
forming a plurality of green compacts, by a process comprising dry pressing a powder comprising ceramic and organic binder to form a green compact
Implementation Method 2
isostatically pressing the laminated assembly to form a pressed laminated assembly
Implementation Method 3
firing the pressed laminated assembly at a temperature sufficient to sinter the ceramic layers together
Implementation Method 4
When a voltage is applied to the electrodes an electrostatic clamping field is generated across the dielectric layer. The gripping force between the substrate and the ESC is proportional to the dielectric properties of the dielectric layer
Data Source
AI summary
A method of forming one or more high temperature co-fired ceramic articles, comprising the steps of:—a) forming a plurality of green compacts, by a process comprising dry pressing a powder comprising ceramic and organic binder to form a green compact;b) disposing a conductor or conductor precursor to at least one surface of at least one of the plurality of green compacts to form at least one patterned green compact;c) assembling the at least one patterned green compact with one or more of the plurality of green compacts or patterned green compacts or both to form a laminated assembly;d) isostatically pressing the laminated assembly to form a pressed laminated assembly;e) firing the pressed laminated assembly at a temperature sufficient to sinter the ceramic layers together.