Multilayer Capacitor Terminal Electrode Laser Damage Resistance
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Solution Overview
Problem
Multilayer capacitors face damage during laser processing for forming via holes in substrates, leading to reduced reliability and increased stress in terminal electrode formation, which affects insulation resistance and connectivity.
Innovation Solution
A multilayer capacitor design with a sintered conductor layer, a thin first plated layer, and a thick second plated layer, where the first terminal electrode is partially on the principal surface and partially on the side surface, and the second terminal electrode is also configured to reduce stress and enhance connectivity, using materials like Cu, Ni, and Au to improve contact and insulation resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal electrode is formed with a thick plated layer to suppress laser beam damage, then reliability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies different plated layer thicknesses at different locations of the terminal electrode. The first plated layer has a maximum thickness that is not more than 1.5 times the thickness of the sintered conductor layer, while the second plated layer has a maximum thickness of not less than twice the thickness of the sintered conductor layer. This local differentiation provides enhanced laser damage resistance where most needed while controlling overall manufacturing complexity.
Solution Approach 2:
The terminal electrode is constructed as a composite structure with three distinct layers: a sintered conductor layer, a first plated layer, and a second plated layer. Each layer serves a specific function - the sintered conductor layer provides basic conductivity, the first plated layer offers moderate protection, and the second plated layer provides enhanced laser damage resistance. This composite approach optimizes both reliability and manufacturability.
2Ease of manufacture
If the multilayer capacitor is reduced in height for built-in mounting, then ease of manufacture is improved, but the ability to withstand laser processing deteriorates
Solution Approach 1:
The patent concentrates the laser damage protection function in the second plated layer, which has a maximum thickness of not less than twice the thickness of the sintered conductor layer. This localized thick plating provides sufficient laser resistance even in reduced-height capacitors, while the overall compact dimensions facilitate built-in mounting in substrates.
Solution Approach 2:
The three-layer composite structure allows the capacitor to maintain reduced height while incorporating a sufficiently thick second plated layer for laser protection. The optimized layer thickness ratios enable both compact form factor and laser processing resistance to coexist.
3Manufacturing precision
If the first plated layer is made thin to reduce stress, then manufacturing precision is improved, but the overall electrode strength may be compromised
Solution Approach 1:
The patent carefully controls the first plated layer thickness to have a maximum thickness not more than 1.5 times the sintered conductor layer thickness, minimizing stress while maintaining adequate strength. The second plated layer compensates with greater thickness (at least twice the sintered conductor layer thickness), providing the necessary overall electrode strength despite the thin first plated layer.
Solution Approach 2:
The composite three-layer structure distributes mechanical strength across multiple layers, allowing the first plated layer to be thin for stress control while the second plated layer provides compensating strength. The combination maintains overall electrode integrity.
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 design reduces stress during laser processing, suppresses damage, and ensures reliable electrical connection and improved insulation resistance, facilitating easier integration into substrates with reduced height and enhanced adhesion.
Implementation Method 1
Each of the first terminal electrode and the second terminal electrode includes a sintered conductor layer formed on the element body
Implementation Method 2
a first plated layer formed on the sintered conductor layer, and a second plated layer formed on the first plated layer
Data Source
AI summary
A length in a first direction of the element body is smaller than a length in a second direction of the element body and smaller than a length in a third direction of the element body, the second direction being perpendicular to the first direction, the third direction being perpendicular to the first and second direction. Each of a first terminal electrode and a second terminal electrode includes a sintered conductor layer formed on the element body, a first plated layer formed on the sintered conductor layer, and a second plated layer formed on the first plated layer. In each of a first electrode portion disposed on a principal face and a third electrode portion disposed on a principal face, a maximum thickness of the sintered conductor layer is larger than a thickness of the first plated layer and not more than a thickness of the second plated layer.