Oscillator Substrate Layout With Shield Wiring for Low Parasitic Capacitance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing piezoelectric devices face limitations in wiring routing flexibility due to narrow intervals between piezoelectric element measurement patterns and ground wiring patterns, leading to reduced degrees of freedom in wiring design and potential signal quality deterioration.
Innovation Solution
The proposed oscillator design incorporates a substrate with a two-layer structure, featuring a shield wiring between coupling and output wiring on the second surface, which reduces parasitic capacitance by increasing the interval between these wirings and allowing for a simpler, more flexible wiring pattern, thereby improving signal characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a ground wiring pattern is provided to surround the piezoelectric element measurement pattern from three directions to reduce capacitance, then the capacitance between the piezoelectric element measurement pattern and output wiring pattern is reduced, but the degree of freedom in wiring routing is reduced due to narrow intervals
Solution Approach 1:
The invention transitions from a single-layer wiring structure to a multi-layer substrate structure. The shield wiring is placed on a different layer (second surface) than the coupling and output wirings (first surface), allowing the shield to surround the piezoelectric element measurement pattern from multiple directions without constraining the routing flexibility of the signal wirings. This dimensional separation resolves the contradiction by enabling effective shielding while maintaining wiring routing freedom.
Solution Approach 2:
A shield wiring is introduced as an intermediary element between the coupling wiring and output wiring. This shield wiring, connected to ground potential, acts as a mediator that reduces the harmful capacitive coupling between the piezoelectric element measurement pattern and output wiring pattern without directly constraining the routing of the signal wirings. The shield serves as a protective intermediate layer that enables both capacitance reduction and routing flexibility.
2Object-affected harmful factors
If the interval between the piezoelectric element measurement pattern and ground wiring pattern is narrowed to reduce capacitance, then the capacitance is reduced, but the wiring routing flexibility is reduced
Solution Approach 1:
The invention uses a multi-layer substrate structure where the shield wiring is positioned on the second surface while the coupling and output wirings are on the first surface. This vertical separation in the Z-dimension allows the shield to be positioned close to the piezoelectric element measurement pattern for effective capacitance reduction, while the signal wirings maintain their routing flexibility on the opposite surface without being constrained by the shield's position.
3Reliability
If a shield wiring is provided between coupling wiring and output wiring with direct-current potential, then parasitic capacitance is reduced and signal characteristics are improved, but substrate structure complexity increases
Solution Approach 1:
The shield wiring is implemented on a separate layer (second surface) of the substrate, utilizing the Z-dimension to add shielding functionality without significantly increasing the planar footprint or complicating the routing of signal wirings on the first surface. This layered approach integrates the shield into the substrate structure in a manner that minimizes additional complexity while achieving improved signal characteristics through reduced parasitic capacitance.
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 configuration enhances the output signal characteristics by reducing parasitic capacitance and increasing the freedom in wiring routing, leading to improved performance and reliability of the oscillator.
Implementation Method 1
a shield wiring that is provided between the first coupling wiring and the output wiring on the second surface and to which a direct-current potential is applied
Data Source
AI summary
An oscillator includes: a resonator element; a circuit element; and a container including a substrate mounted with the circuit element, in which the circuit element includes a first coupling terminal coupled to the resonator element, a second coupling terminal coupled to the resonator element and aligned in a first direction with the first coupling terminal in the first direction, and an output terminal disposed adjacent to the first coupling terminal in a second direction orthogonal to the first direction, in the second direction orthogonal to the first direction, and in which the substrate includes a first surface mounted with the circuit element and a second surface, and the substrate includes a first coupling electrode provided on the first surface and coupled to the first coupling terminal, a second coupling electrode coupled to the second coupling terminal, an output electrode coupled to the output terminal, a first coupling wiring provided on the second surface and coupled to the first coupling electrode, a second coupling wiring coupled to the second coupling electrode, an output wiring coupled to the output electrode, and a shield wiring that is provided between the first coupling wiring and the output wiring and to which a direct-current potential is applied.