Multilayer Ceramic Capacitor Reactive Layer for Peeling Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multilayer ceramic capacitors face issues with external electrode peeling due to the dissolution of glass in Cu plating baths, which affects adhesion strength and leads to potential damage during laser via hole formation in multilayer printed wiring boards.
Innovation Solution
Incorporating a reactive layer with specific compositions of Ti, Si, and V between the ceramic body and base layers, which enhances resistance to Cu plating baths and prevents peeling by improving adhesion strength, and using oxidized Cu plated layers for increased adhesion to the resin in the wiring board.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the external electrodes are composed of a laminate body including a base layer and a Cu plated layer, then the adhesion strength to resin is improved, but the glass in the base electrode layers is dissolved by the Cu plating bath, causing the external electrodes to be peeled
Solution Approach 1:
A reactive layer comprising Ti, Si, and V is introduced as an intermediary between the base electrode layer and the Cu plated layer. This reactive layer serves as a barrier that prevents the Cu plating bath from dissolving the glass in the base electrode layer, thereby maintaining adhesion strength while preventing peeling during laser via hole formation.
Solution Approach 2:
The external electrode is constructed as a composite laminate body consisting of multiple layers: a base electrode layer, a reactive layer with specific metal composition (Ti, Si, V), and a Cu plated layer. This composite structure combines the adhesion properties of the base layer with the protective and reflective properties of the reactive layer and Cu plated layer.
2Reliability
If the outermost layers of external electrodes are composed of Cu plated layers, then damage to external electrodes during laser via hole formation is suppressed, but the Cu plating bath dissolves the glass of base electrode layers, making external electrodes likely to be peeled
Solution Approach 1:
The reactive layer acts as a protective intermediary between the Cu plated layer and the base electrode layer. It prevents the Cu plating bath from contacting and dissolving the glass in the base electrode layer, thereby maintaining adhesion strength while allowing the Cu plated layer to provide laser damage suppression.
Solution Approach 2:
Different layers of the external electrode are assigned different local qualities: the base electrode layer provides adhesion to the ceramic body, the reactive layer provides chemical resistance to the plating bath, and the Cu plated layer provides laser reflectivity and damage resistance. Each layer is optimized for its specific function.
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 effectively prevents external electrode peeling and ensures strong adhesion to the ceramic body and resin, enhancing the reliability and durability of multilayer ceramic capacitors in compact electronic devices.
Implementation Method 1
Incorporating a reactive layer with specific compositions of Ti, Si, and V between the ceramic body and base layers, which enhances resistance to Cu plating baths and prevents peeling by improving adhesion strength
Implementation Method 2
using oxidized Cu plated layers for increased adhesion to the resin in the wiring board
Data Source
AI summary
A multilayer ceramic capacitor includes an external electrode that is unlikely to be peeled. First and second external electrodes each include base layers provided over a ceramic body and including a metal and glass, and Cu plated layers provided over the base layers. The multilayer ceramic capacitor includes a reactive layer. The reactive layer contains about 5 atomic % to about 15 atomic % of Ti, about 5 atomic % to about 15 atomic % of Si, and about 2 atomic % to about 10 atomic % of V.