TSV-Based Oscillator WLP Using Silicon Homogeneity
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Solution Overview
Problem
Existing oscillator package structures using ceramic substrates are expensive, have unstable raw material supplies, and suffer from thermal stress due to differing thermal expansion coefficients between the substrate and quartz crystal resonator elements, making them costly and difficult to miniaturize.
Innovation Solution
A TSV-based oscillator Wafer Level Package (WLP) structure using a silicon base and cap, with vias formed on the same side of the silicon base to eliminate the need for ceramic substrates, reduce package size, and minimize thermal stress by using identical materials for the cap and base, and shortening interconnection lines to decrease parasitic capacitance and inductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ceramic substrates are used in oscillator package structures, then thermal stress is reduced due to matching thermal expansion coefficients, but fabrication costs increase and raw material supply becomes unstable
Solution Approach 1:
The patent applies homogeneity by making both the cap and base from the same silicon material, eliminating the need for ceramic substrates with matched thermal expansion coefficients. This single-material approach reduces fabrication complexity and cost while maintaining thermal stress stability through uniform material properties throughout the package structure.
2Reliability
If ceramic substrates are used in oscillator packages, then thermal expansion matching is achieved, but package size reduction and miniaturization become difficult
Solution Approach 1:
By using silicon for both the cap and base, the patent eliminates the need for thick ceramic substrates required for thermal expansion matching. This allows for a thinner, more compact package structure that achieves thermal stress stability through material uniformity rather than thickness, enabling significant package size reduction.
3Reliability
If vias are formed on opposite sides of the silicon base, then electrical connection is achieved, but parasitic capacitance and inductance increase due to longer interconnection lines
Solution Approach 1:
The patent transitions from a traditional opposite-side via arrangement to a same-side configuration, effectively changing the spatial dimension of interconnection. By forming both vias on the same side of the silicon base and routing them through the thickness of the base, the interconnection length is dramatically reduced, minimizing parasitic capacitance and inductance while maintaining reliable electrical connection.
4Reliability
If traditional package structures are used, then oscillators can be packaged, but mass production efficiency and productivity are reduced
Solution Approach 1:
The patent applies segmentation by dividing the silicon base into multiple independently processable units with vias formed on the same side, allowing for parallel processing and wafer-level fabrication. This modular approach enables simultaneous manufacturing of multiple oscillators on a single wafer, dramatically improving mass production efficiency while maintaining package functionality.
Data Source
AI summary
The present invention provides a TSV-based oscillator WLP structure and a method for fabricating the same. The method of the present invention comprises steps: providing a silicon base having an oscillator unit disposed thereon; forming on the silicon base at least one package ring surrounding the oscillator unit; and disposing a silicon cap on the package ring to envelop the oscillator unit. The present invention adopts a cap and a base, which are made of the same material, to effectively overcome the problem of thermal stress occurring in a conventional sandwich package structure. Further, the present invention elaborately designs the wiring on the lower surface of the base to reduce the package size and decrease consumption of noble metals.