Acoustic Wave Filter Grounding via Through-Substrate Vias
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing acoustic wave filters, particularly double mode surface acoustic wave (DMS) filters, face performance issues due to parasitic inductance caused by metal bridge structures used for grounding, which affects their performance and limits their placement on the package, and they require complex manufacturing processes.
Innovation Solution
The use of through-substrate vias (TSVs) to directly connect multi-mode surface acoustic wave (MMS) resonators or filters to ground, reducing parasitic inductance and simplifying the manufacturing process by eliminating the need for metal bridge structures, allowing for flexible placement of the filters on the package.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal bridge structures are used for grounding DMS filters, then grounding connection is achieved, but parasitic inductance increases and placement flexibility is limited
Solution Approach 1:
The patent extracts and eliminates the metal bridge structure from the grounding path. Instead of using metal bridges to connect DMS filters to ground, the invention uses through-substrate vias that go directly through the package substrate to establish ground connections, removing the source of parasitic inductance while maintaining reliable grounding
Solution Approach 2:
The patent transitions from planar metal bridge connections to three-dimensional through-substrate via connections. The ground connection is achieved by drilling vias through the entire package substrate thickness, creating a vertical dimensional path that eliminates the horizontal metal bridge structure and its associated parasitic inductance
2Reliability
If metal bridge structures are used for grounding, then grounding is provided, but device placement flexibility is limited
Solution Approach 1:
The through-substrate via structure serves multiple functions: it provides ground connections, enables flexible component placement, and simplifies the manufacturing process. The universal via approach allows DMS filters to be placed at various locations on the package without requiring specific metal bridge routing, enhancing design flexibility
3Reliability
If metal bridge structures are used, then grounding connection is achieved, but manufacturing process complexity increases
Solution Approach 1:
The patent merges the ground connection function into the existing through-substrate via structure that is already part of the package assembly process. By combining the ground connection requirement with the standard via fabrication process, the invention eliminates the need for separate metal bridge fabrication, routing, and assembly steps, thereby simplifying the overall manufacturing process
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 solution improves the attenuation performance of the filters by reducing parasitic inductance and simplifying the manufacturing process, enabling better filter performance and placement flexibility, as demonstrated by the improved transmission characteristics versus frequency graphs.
Implementation Method 1
One or more vias extend through the support substrate and are electrically connected to the multi-mode surface acoustic wave resonator or filter and the one or more metal layers to provide a ground connection
Implementation Method 2
One or more surface acoustic wave resonators or filters are disposed over the multi-layer piezoelectric substrate, the one or more surface acoustic wave resonators or filters including a multi-mode surface acoustic wave resonator or filter
Implementation Method 3
a multi-layer piezoelectric substrate disposed over a first side of the support substrate
Data Source
AI summary
A method of manufacturing a packaged acoustic wave component includes forming a support substrate, forming a multi-layer piezoelectric substrate over a first side of the support substrate, and forming one or more metal layers over a second side of the support substrate that is opposite the first side of the support substrate. The method also includes forming one or more surface acoustic wave resonators or filters (including a multi-mode surface acoustic wave resonator or filter) over the multi-layer piezoelectric substrate. The method also includes forming one or more vias through the support substrate, and electrically connecting the multi-mode surface acoustic wave resonator or filter and the metal layers with the vias to provide a ground connection for the multi-mode surface acoustic wave resonator or filter.