Ceramic Shrinkage Control via Ball Mill Mass Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods struggle to accurately control the shrinkage of ceramic bodies during firing, particularly in the manufacturing of multi-layer ceramic substrates, due to fluctuations in ceramic powder properties and processing conditions.
Innovation Solution
A method is developed to determine the correlation between the mass of ceramic powder taken out from a dry-type ball mill and the average shrinkage of formed ceramic bodies, allowing for adjustments to manufacturing conditions to achieve a target shrinkage rate by modifying heat treatment, dispersant content, and mixing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If fixed manufacturing conditions are constantly employed to control shrinkage, then manufacturing stability is maintained, but shrinkage fluctuation cannot be suppressed due to variations in ceramic powder properties
Solution Approach 1:
The patent measures the specific surface area of ceramic powder before forming and uses this measurement to feedback-adjust firing conditions. The control unit modifies firing temperature or time based on the measured specific surface area to achieve target shrinkage, creating a closed-loop control system that adapts to powder variations.
Solution Approach 2:
The patent changes firing parameters (temperature, time) based on the measured specific surface area of the ceramic powder. By adjusting these parameters dynamically according to powder properties, the system achieves consistent shrinkage control despite variations in different powder batches.
2Stability of the object's composition
If all manufacturing conditions are maintained constant, then process stability is achieved, but dimensional accuracy of fired bodies deteriorates due to shrinkage fluctuation
Solution Approach 1:
The system measures specific surface area and feeds this information back to adjust firing conditions, allowing the process to maintain stability in terms of control methodology while adapting the actual firing parameters to achieve consistent dimensional accuracy in the final product.
Solution Approach 2:
The patent performs preliminary measurement of the specific surface area of ceramic powder before the forming and firing processes. This advance measurement allows for pre-determination of appropriate firing conditions, ensuring dimensional accuracy is achieved before the actual firing occurs.
3Ease of operation
If conventional fixed-condition manufacturing is used, then operational simplicity is maintained, but shrinkage control reliability deteriorates
Solution Approach 1:
The automated feedback control system measures specific surface area and automatically adjusts firing conditions through a control unit, maintaining ease of operation while significantly improving shrinkage control reliability through data-driven decision making.
Solution Approach 2:
The patent replaces manual judgment and fixed mechanical procedures with an automated measurement and control system that uses specific surface area data to determine firing conditions, improving reliability while maintaining operational simplicity through automation.
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 effectively suppresses shrinkage fluctuations, ensuring accurate control and approximation to a target rate, thereby improving the dimensional accuracy of ceramic products, especially for electronic components like ICs and condensers.
Implementation Method 1
ceramic powder ground by a dry-type ball mill
Implementation Method 2
ground using attritor (hereinafter referred to as a dry-type ball mill)
Implementation Method 3
The ground ceramic powder is taken out from the ball mill and treated with heat
Implementation Method 4
The formed body is then dried and fired
Implementation Method 5
The formed body is then dried and fired
Data Source
AI summary
A method for controlling the shrinkage of ceramic formed bodies is provided, including performing a preliminary test to determine an average shrinkage of ceramic formed bodies made from test lots of a ceramic powder, and determining a linear correlation between the average shrinkage and measured amounts of the ground test lots removed from a ball mill during a specific milling time interval. A batch of the ceramic powder is then ground, an amount of the ground ceramic powder removed from the ball mill during the specific time interval is measured, and the linear correlation is used to estimate the shrinkage of a ceramic body made therefrom. The difference between a target shrinkage and the estimated shrinkage is determined, and one or more of the processing conditions used to form the ceramic body are changed to offset the difference.