External Electrode Plating Structure to Prevent Resin-Layer Peeling
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Solution Overview
Problem
The peeling of plating films on resin layers in electronic components, which can lead to contact failures and operational issues, is not effectively addressed by existing technologies, particularly due to low adhesion and internal strength of disordered plating films formed during the plating process.
Innovation Solution
The formation of plating films with a face-centered cubic structure, specifically oriented to the (111) plane, is achieved by optimizing the plating bath and conditions, enhancing the adhesion between the resin layer and the plating film, and improving the plating film's strength, as indicated by a Lotgering factor F value between 0.20 and 0.50, to prevent peeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a plating film is formed on a resin layer during the plating process, then the external electrode structure is complete, but the plating film peels off due to low adhesion and internal strength
Solution Approach 1:
The patent changes the crystallographic orientation parameters of the plating film by controlling the plating process to achieve a specific range of (111) plane orientation (30-70 degrees). This parameter change transforms the plating film from a disordered structure with low strength to an oriented structure with enhanced adhesion and internal strength, preventing peeling while maintaining electrical conductivity.
2Stability of the object's composition
If a resin layer is introduced between the ceramic body and plating film to prevent ceramic cracking, then thermal stress resistance is improved, but the plating film becomes prone to peeling
Solution Approach 1:
The patent applies local quality by creating a gradient in crystallographic orientation within the plating film. The (111) plane orientation is specifically controlled in the region adjacent to the resin layer to maximize adhesion, while maintaining overall electrical conductivity. This localized optimization allows the plating film to simultaneously achieve strong bonding to the resin layer and maintain its functional properties.
3Productivity
If conventional plating processes are used to form the plating film, then the process is simple and fast, but the plating film has disordered structure leading to peeling
Solution Approach 1:
The patent implements preliminary action by pre-establishing specific plating conditions (bath composition, temperature, current density, and duration) before the plating process begins. These pre-determined parameters ensure that the plating film develops the required (111) plane orientation during deposition, achieving both high productivity and precise crystallographic control without requiring complex post-processing or inspection.
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
This approach significantly reduces or prevents peeling of the plating films, ensuring improved adhesion and strength, thereby maintaining the operational integrity of electronic components, especially in small chip-type components where contact area is limited.
Implementation Method 1
a metal plating film formed by electrolytic plating, electroless plating, or the like
Implementation Method 2
a metal plating film formed by electrolytic plating, electroless plating, or the like
Implementation Method 3
a conductive epoxy-based thermosetting resin layer including a metal powder (hereinafter, sometimes referred to as a 'resin layer') between a baked electrode and a plating layer in an external electrode of an electronic component. The resin layer functions as a stress absorbing layer, and can suppress the occurrence of a crack in the ceramic body.
Data Source
AI summary
In an electronic component including a ceramic body and an external electrode, the external electrode includes a resin layer including a conductive powder and a plating film in direct contact with the resin layer. The plating film includes a metal with a face-centered cubic structure, and a value of F is about 0.20 or more and about 0.50 or less, where F=(P−P0)/(1−P0), P0=I0(111)/{I0(111)+I0(200)+I0(220)} and P=I(111)/{I(111)+I(200)+I(220)}, and I0 (111), I0 (200), and I0 (220) are diffraction intensities of a (111) plane, a (200) plane, and a (220) plane obtained from known powder X-ray diffraction data for a metal in the plating film, and I (111), I (200), and I (220) are diffraction intensities of a (111) plane, a (200) plane, and a (220) plane obtained from an X-ray diffraction pattern of the plating film.