Multilayer Ceramic Capacitor Internal Electrode Grain Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The reduction in thickness of dielectric and internal electrode layers in multilayer ceramic capacitors leads to a decrease in the continuity modulus and strength of the internal electrode, making them prone to cracking during mounting due to excessive sintering and spheroidization of metal components.
Innovation Solution
A multilayer ceramic capacitor design with internal electrode layers having a crystal grain boundary of 1/μm or more in the extension direction, using a metal conductive paste with an average grain diameter of 100 nm or less and a ceramic co-material with a grain size distribution standard deviation of 5 or less, to suppress excessive sintering and enhance the continuity modulus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the thickness of dielectric layers and internal electrodes is reduced to downsize the capacitor chip, then the chip size is reduced, but the internal electrode strength decreases and cracks may occur during mounting
Solution Approach 1:
The patent changes the grain size parameter of the internal electrode material to sub-100nm scale, which fundamentally alters the sintering behavior and microstructure formation. This parameter change enables the internal electrode to maintain high strength even at reduced thickness, resolving the contradiction between chip downsizing and electrode strength maintenance
Solution Approach 2:
The patent uses a composite material system consisting of metal particles (main component) and ceramic particles (co-material) in the internal electrode paste. This composite structure prevents excessive sintering and spheroidization, maintaining the continuity modulus and strength of the internal electrode even when thickness is reduced for chip downsizing
2Ease of manufacture
If metal conductive paste with larger grain diameter is used, then the manufacturing process is simpler, but the continuity modulus decreases and the internal electrode becomes prone to breaking
Solution Approach 1:
The patent specifies a grain diameter parameter of 100nm or less for the metal particles in the conductive paste, which is a significant parameter change from conventional larger grains. This parameter control ensures high continuity modulus and prevents breaking, while the standardized paste formulation maintains manufacturing feasibility
Solution Approach 2:
The patent applies local quality control by specifying different grain size requirements for different components: metal particles ≤100nm and ceramic co-material particles ≤10nm. This localized quality specification optimizes the sintering behavior and microstructure at the internal electrode level, ensuring high reliability without compromising overall manufacturability
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 solution increases the strength of the internal electrode layers, reducing the likelihood of cracking and maintaining a high continuity modulus, thereby enhancing the overall strength and reliability of the multilayer ceramic capacitors.
Implementation Method 1
a number of crystal grain boundary of the main component of the internal electrode layer is 1/μm or more in an extension direction of the internal electrode layer
Data Source
AI summary
A multilayer ceramic capacitor includes: a multilayer structure in which each of dielectric layers and each of internal electrode layers are alternately stacked, a main component of the dielectric layers being ceramic, a main component of the internal electrode layers being a metal, wherein: a number of crystal grain boundary of the main component of the internal electrode layer is 1/μm or more in an extension direction of the internal electrode layer; and the internal electrode layers include a grain of which a main component is ceramic.