Ferrite Sintered Composition for DC Bias and Plating Reliability
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Solution Overview
Problem
Existing ferrite sintered bodies and multilayer coil components face challenges in achieving good DC superposition characteristics and sinterability while minimizing plating elongation, as increasing zinc silicate content degrades sinterability and increasing bismuth oxide content can lead to reliability issues due to plating elongation defects.
Innovation Solution
A ferrite sintered body composition with specific ranges of Fe, Zn, Cu, Si, Bi, Mn, and Cr, along with a multilayer coil component design featuring insulating layers made from this sintered body, which alternately stack with coil conductors to enhance DC superposition characteristics and sinterability while reducing plating elongation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If zinc silicate content is increased to improve DC superposition characteristic, then magnetic permeability improves, but sinterability degrades
Solution Approach 1:
The patent applies parameter changes by precisely controlling the zinc silicate content within 8-76 wt% range and bismuth oxide within 0.025-0.231 wt% range, along with specific Fe (4-13 mol%), Zn (47-58 mol%), Cu (1-4 mol%), Ni (2-8 mol%), and Si (28-36 mol%) compositions. This optimized parameter combination enables the material to achieve both improved DC superposition characteristic and maintained sinterability, resolving the technical contradiction between these two properties.
2Ease of manufacture
If bismuth oxide content is increased to improve sinterability, then sinterability improves, but plating elongation occurs degrading reliability
Solution Approach 1:
The patent resolves this contradiction by precisely controlling bismuth oxide content within 0.025-0.231 wt% range combined with zinc silicate 8-76 wt%, Fe 4-13 mol%, Zn 47-58 mol%, Cu 1-4 mol%, Ni 2-8 mol%, and Si 28-36 mol%. This optimized parameter combination achieves good sinterability while suppressing plating elongation, thereby maintaining reliability.
3Reliability
If zinc silicate content is increased to improve DC superposition characteristic, then magnetic permeability improves, but sinterability degrades
Solution Approach 1:
The patent applies composite materials principle by creating a multi-component ferrite system comprising spinel ferrite combined with zinc silicate, bismuth oxide, and other metal oxides (Fe, Cu, Ni, Si) in specific ratios. This composite structure enables the material to achieve both improved DC superposition characteristic and maintained sinterability, resolving the technical contradiction between these two properties through synergistic material composition.
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 proposed solution achieves a ferrite sintered body with improved DC superposition characteristics and sinterability, maintaining low plating elongation, and a multilayer coil component with enhanced magnetic permeability and reliability, as demonstrated by specific composition ranges and processing methods.
Implementation Method 1
a ferrite sintered body according to the present disclosure contains a main component and a sub component
Data Source
AI summary
A ferrite sintered body contains a main component and a sub component. The main component contains from 4 mol % to 13 mol % of Fe in terms of Fe2O3, from 47 mol % to 58 mol % of Zn in terms of ZnO, from 1 mol % to 4 mol % of Cu in terms of CuO, from 2 mol % to 8 mol % of Ni in terms of NiO, and from 28 mol % to 36 mol % of Si in terms of SiO2. The sub component contains, per 100 parts by weight of the main component, from 0.8 parts by weight to 3 parts by weight of Bi in terms of Bi2O3, from 0.003 parts by weight to 0.1 parts by weight of Mn in terms of Mn2O3, and from 0.003 parts by weight to 0.1 parts by weight of Cr in terms of Cr2O3.