Crystal Resonator Packaging Structure for Stable Q in Compact Oscillators
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Solution Overview
Problem
Existing crystal-oscillating devices face challenges in size reduction while maintaining a favorable Q value, as size reduction of the crystal oscillation plate impairs oscillation and direct connection to packaging materials can lead to unstable Q values due to stress and oscillation propagation.
Innovation Solution
A crystal-oscillating device design featuring a crystal resonator mounted on a first packaging material with a joining member, surrounded by laminated second and third packaging materials forming a sealing space, where the second packaging material surrounds the outer peripheral edge of the resonator and is formed from the same crystal substrate, along with a damping material to prevent stress propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the size of the crystal oscillation plate is reduced to achieve size reduction of the crystal-oscillating device, then the device size is reduced, but the oscillation portion becomes insufficient and the Q value deteriorates
Solution Approach 1:
The packaging structure is divided into multiple layers (first packaging material, second packaging material, third packaging material) with the crystal resonator mounted on the first layer. This segmentation allows the crystal resonator to maintain its size for adequate oscillation while the overall device size is reduced through compact multi-layer packaging.
Solution Approach 2:
The patent transitions from a planar packaging arrangement to a three-dimensional multi-layer stacked structure. The crystal resonator is mounted on the first packaging material, with second and third packaging materials laminated thereon to form a sealing space, effectively utilizing vertical space to reduce the device footprint while maintaining resonator dimensions.
2Device complexity
If the crystal resonator is directly connected to the packaging material to simplify the structure, then the device complexity is reduced, but stress and oscillation from the packaging material propagate to the crystal resonator causing unstable Q value
Solution Approach 1:
A joining member is introduced as an intermediary component between the first packaging material and the crystal resonator. This joining member electrically connects and mechanically joins the two components while isolating the crystal resonator from stress and oscillation propagation from the packaging material, thereby maintaining stable Q value.
3Reliability
If the crystal resonator is sealed by laminating multiple packaging materials to improve protection, then the reliability is improved, but the device size increases
Solution Approach 1:
The patent employs thin packaging material layers (first, second, and third packaging materials) that are laminated to form a sealing space around the crystal resonator. These thin film structures provide adequate protection and sealing while minimizing the volume increase, enabling compact device packaging.
Data Source
AI summary
A crystal-oscillating device is disclosed with a reduction in size and a favorable Q value. The crystal-oscillating device includes a first packaging material; a crystal resonator mounted on the first packaging material; joining members that join the first packaging material to the crystal resonator; a first sealing frame for joining the second and third packaging materials, the first packaging material, and the second packaging material; and a second sealing frame for joining the second packaging material and the third packaging material to each other. Preferable, the second packaging material is formed in a frame shape to surround an outer peripheral edge of the crystal resonator, and the second packaging material and a crystal substrate of the crystal resonator are formed from the same crystal substrate.