Thin-Film Capacitor Through Holes Suppress Cracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-layered thin-film capacitors are prone to internal cracking and peeling due to the vulnerability of their dielectric and electrode layers, which hampers their yield and performance.
Innovation Solution
Incorporating through holes in the internal electrodes made of nickel as a principal component, with specific surface area and ratio ranges, to reduce stress and enhance bonding between the electrodes and dielectric layers, thereby suppressing peeling and cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If multi-layered thin-film capacitors use very thin dielectric layers or internal electrode layers to achieve small cubic volume and high electrostatic capacitance, then the capacitor size is reduced and capacitance is increased, but the internal dielectric layer or electrode layer becomes prone to internal cracking and peeling
Solution Approach 1:
The patent applies the porous materials principle by forming through-holes in the internal electrode layers. These through-holes create a controlled porous structure that allows stress to be distributed and released, preventing the internal cracking and peeling that would otherwise occur in very thin electrode layers. The through-holes act as stress relief channels while maintaining the electrical conductivity of the electrode structure.
Solution Approach 2:
The patent applies segmentation by dividing the continuous internal electrode layer into multiple segments separated by through-holes. This segmentation allows each segment to move independently under stress, preventing the propagation of cracks across the entire electrode layer. The electrode layer is effectively divided into multiple smaller, stress-isolated units.
2Productivity
If the internal dielectric layer or electrode layer is made very thin to increase capacitance density, then the electrostatic capacitance per volume is increased, but the yield is reduced due to cracking and peeling
Solution Approach 1:
The controlled porous structure formed by through-holes in the internal electrode layers enables the use of very thin electrode layers without sacrificing structural integrity. This allows high capacitance density to be achieved while maintaining sufficient mechanical strength to prevent manufacturing defects such as cracking and peeling, thereby improving yield.
Solution Approach 2:
The patent changes the physical and geometric parameters of the internal electrode layers by introducing through-holes with specific dimensions and distributions. This parameter modification transforms the electrode structure from a solid continuous layer to a controlled porous structure, enabling thin-layer fabrication without the mechanical failures that would otherwise reduce yield.
3Reliability
If through holes are added to the internal electrode layer to prevent cracking and peeling, then structural integrity is improved, but the electrode complexity increases
Solution Approach 1:
The through-hole structure, while adding geometric complexity, creates a regular porous pattern that can be manufactured using standardized processes. The complexity is controlled and systematic rather than random, allowing for scalable production. The through-holes form a predictable porous structure that enhances reliability without requiring complex custom fabrication techniques.
Data Source
AI summary
A thin-film capacitor that is less prone to generation of internal cracking or peeling is provided. In a thin-film capacitor according to the present embodiment, because through holes H are formed in internal electrodes containing Ni as a principal component in a lamination direction, a surface area of at least some of the through holes H is in the range of 0.19 μm2 to 7.0 μm2, and a ratio of a surface area of the through holes H to a surface area of an entire main surface of the internal electrodes is in the range of 0.05% to 5%, peeling or cracking is suppressed from occurring at the boundaries between the internal electrodes and dielectric layers, and as a result, the yield is enhanced.