Recessed Capacitor Electrode Layout for Thermal Stress Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing passive components in communication modules experience variations in electrostatic capacity due to thermal stress, leading to undesired filter characteristic changes, particularly at the edge portions of the dielectric film.
Innovation Solution
A passive component design featuring a substrate with a recess filled by a bottom electrode, a dielectric film covering the electrode, and a top electrode, where the bottom electrode's dimension is larger than the dielectric film's dimension, reducing thermal stress concentration and electrostatic capacity variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the bottom electrode and dielectric film have the same dimension, then the capacitor structure is simple, but thermal stress concentrates at the edge portion causing cracks and electrostatic capacity variation
Solution Approach 1:
The patent applies asymmetry by making the bottom electrode larger than the dielectric film in plan view, creating an overlapped region. This asymmetric configuration distributes thermal stress away from the dielectric film edges, preventing crack formation while maintaining structural simplicity. The bottom electrode extends beyond the dielectric film boundaries, forming a stress-absorbing perimeter that protects the capacitor from thermal degradation.
2Reliability
If thermal stress is reduced on the dielectric film, then electrostatic capacity variation decreases, but this requires a more complex electrode configuration
Solution Approach 1:
The patent applies local quality by creating a specific structural relationship between the bottom electrode and dielectric film, where the bottom electrode intentionally extends beyond the dielectric film boundaries in the plan view. This localized geometric configuration concentrates the stress-absorbing function in the overlapped region, protecting the dielectric film from thermal stress without requiring complex materials or multi-layer structures elsewhere in the capacitor.
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 effectively minimizes thermal stress-induced electrostatic capacity variations, enhancing the Q value of the capacitor and maintaining consistent filter characteristics under thermal load.
Implementation Method 1
thermal stress is generated due to a difference in coefficient of linear expansion between the bottom electrode and the dielectric film
Data Source
AI summary
A passive component includes a substrate having insulating properties and having a surface having a recess, a bottom electrode filling at least a portion of the recess, a dielectric film provided on a surface of the bottom electrode, and a top electrode opposite to the bottom electrode with the dielectric film interposed therebetween. In a height direction perpendicular to the surface of the substrate, a dimension of the bottom electrode is larger than a dimension of the dielectric film.