Package-Integrated FBAR Filters on Organic Substrates
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Solution Overview
Problem
Current wireless systems require numerous filters with high quality factors and smaller form factors, but existing technologies like integrated passive networks and Si-MEMS resonators are either large and costly or require assembly of discrete components, which is inefficient and expensive.
Innovation Solution
The integration of piezoelectric film bulk acoustic resonator (FBAR) devices directly into package substrates using organic panel-level manufacturing, allowing for in-situ fabrication of compact, high-quality filters without the need for external components or expensive Si-MEMS processing, utilizing deposited piezoelectric materials and vibrating structures that create acoustic waves for signal filtering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If integrated passive networks are used for filters, then the filters can be assembled onto the package substrate, but the filters suffer from large size and high losses due to inductor quality factors
Solution Approach 1:
The patent merges the filter functionality directly into the package substrate by integrating piezoelectric FBAR resonators with the substrate structure. This eliminates the need for separate discrete filter components and their associated assembly processes, achieving both compact size and manufacturing efficiency through structural integration
Solution Approach 2:
The patent replaces traditional mechanical inductor-based passive networks with piezoelectric FBAR resonators that use acoustic wave propagation through piezoelectric materials. This substitution eliminates the large inductor components and their quality factor losses, achieving compact filters with superior electrical performance
2Area of stationary object
If Si-MEMS resonators are used, then smaller size and higher quality factors are achieved, but the fabrication requires micromachining of expensive materials and assembly as discrete components
Solution Approach 1:
The patent integrates the FBAR resonator structure directly into the package substrate, eliminating the need for separate Si-MEMS discrete components. This integration achieves compact size while simplifying manufacturing by using standard piezoelectric deposition processes on organic substrates rather than expensive Si-MEMS micromachining
Solution Approach 2:
The patent changes the material parameter from expensive silicon-based MEMS materials to cost-effective piezoelectric materials (such as aluminum nitride or zinc oxide) that can be deposited using standard thin-film techniques on organic package substrates, achieving both size reduction and manufacturing simplification
3Ease of manufacture
If glass or LTCC substrates are used for filter fabrication, then filters can be manufactured, but they are expensive due to base substrate material and require separate large packages
Solution Approach 1:
The patent merges the filter fabrication process with the package substrate manufacturing by depositing piezoelectric materials directly onto organic package substrates. This integration eliminates the need for separate glass or LTCC substrate fabrication and assembly, achieving both manufacturing ease and compact package size
Solution Approach 2:
The patent changes the substrate material parameter from expensive glass or LTCC to cost-effective organic materials that can be processed using standard PCB and packaging techniques, achieving both affordability and compact form factor
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 enables the creation of smaller, thinner, and more cost-effective wireless systems with high resonant frequencies, eliminating the need for discrete components and reducing manufacturing costs while achieving higher frequency capabilities than surface acoustic wave resonators.
Implementation Method 1
a piezoelectric device integrated with the package substrate. The piezoelectric device includes a first electrode, a piezoelectric material in contact with the first electrode, and a second electrode in contact with the piezoelectric material
Implementation Method 2
The film stack generates an acoustic wave to be propagated across the film stack in response to an application of an electrical signal between the first and second electrodes
Data Source
AI summary
Embodiments of the invention include a piezoelectric package integrated filtering device that includes a film stack. In one example, the film stack includes a first electrode, a piezoelectric material in contact with the first electrode, and a second electrode in contact with the piezoelectric material. The film stack is suspended with respect to a cavity of an organic substrate having organic material and the film stack generates an acoustic wave to be propagated across the film stack in response to an application of an electrical signal between the first and second electrodes.