Stacked Acoustic Wave Filter Packaging with TSV Yield Decoupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for manufacturing stacked acoustic wave filters result in a total yield that is the product of the yields of the top and bottom filters, leading to reduced efficiency due to wafer-to-wafer bonding, which limits the overall performance and reliability of the filters.
Innovation Solution
A multi-layer piezoelectric substrate silicon package is developed with double side external terminals and through silicon vias (TSVs) to provide independent electrical paths between the top and bottom filters, allowing for separate fabrication and inspection of each filter, thereby increasing the overall yield and reducing mechanical stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If wafer-to-wafer bonding is used to manufacture stacked acoustic wave filters, then the filters can be integrated in a compact stacked structure, but the total yield becomes the product of individual filter yields leading to reduced manufacturing efficiency
Solution Approach 1:
The patent divides the stacked filter structure into independently packaged units. Each acoustic wave filter is separately packaged with its own substrate and encapsulation, allowing independent fabrication and testing. This segmentation enables the total yield to be the sum of individual filter yields rather than the product, significantly improving manufacturing efficiency while maintaining the compact stacked configuration.
2Volume of moving object
If wafer-to-wafer bonding is used to manufacture stacked acoustic wave filters, then the filters can be integrated in a compact stacked structure, but the mechanical stress from bonding reduces reliability
Solution Approach 1:
The patent extracts the bonding process from the final assembly stage. By separately packaging each filter on its own substrate before stacking, the mechanical stress of bonding is distributed across multiple independent bonding interfaces rather than concentrated in a single wafer-to-wafer bonding step. This reduces the risk of failure and improves overall reliability of the stacked structure.
3Productivity
If independent packaging of each filter is implemented, then manufacturing yield improves, but the device complexity increases due to additional packaging steps
Solution Approach 1:
The patent merges the packaging process with the standard filter fabrication流程. Each filter is packaged on its own substrate using conventional packaging techniques that are already part of the manufacturing process. This approach avoids adding significant complexity while achieving independent packaging, as the packaging steps are integrated into the existing fabrication flow rather than being separate additional processes.
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 enhances the yield of stacked acoustic wave filters by decoupling the yields of the top and bottom filters, resulting in improved reliability and performance by allowing for independent optimization and inspection of each filter layer.
Implementation Method 1
a first through silicon via (TSV) configured to provide an electrical path from a first bottom terminal of the device wafer of the bottom filter to a first top terminal of the cap wafer of the bottom filter
Implementation Method 2
The surface acoustic wave resonator can generate a surface acoustic wave on a surface of the piezoelectric layer on which the interdigital transductor electrode is disposed
Implementation Method 3
An acoustic wave filter can include a plurality of resonators arranged to filter a RF signal. Example acoustic wave filters include surface acoustic wave (SAW) filters and bulk acoustic wave (BAW) filters
Implementation Method 4
A surface acoustic wave resonator can include an interdigital transductor electrode on a piezoelectric substrate. The surface acoustic wave resonator can generate a surface acoustic wave on a surface of the piezoelectric layer
Data Source
AI summary
A multi-layer piezoelectric substrate silicon package comprises a bottom filter including a cap wafer of the bottom filter, and a device wafer of the bottom filter, the cap wafer of the bottom filter and the device wafer of the bottom filter each having a first through silicon via configured to provide an electrical path from a first bottom terminal of the device wafer of the bottom filter to a first top terminal of the cap wafer of the bottom filter.