Piezoelectric Vibrator Substrate Layout for Warpage and Stress Control
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Solution Overview
Problem
The existing piezoelectric devices face issues with stress and warpage due to the formation of insulating layers on the inner and lower surfaces of the substrate, leading to increased residual stress and deformation.
Innovation Solution
A vibrator device configuration with a semiconductor substrate base and lid, featuring divided insulating layers on the upper and lower surfaces to reduce film stress and internal stress, with internal and external terminals strategically placed to minimize warpage and enhance insulation reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If insulating layers are formed on the inner surface and lower surface of the substrate to suppress deformation, then the substrate deformation is reduced, but the residual stress in the substrate increases
Solution Approach 1:
The insulating layers are divided into multiple separate regions rather than forming continuous layers. The first insulating layer is divided into a first insulating region and a second insulating region, while the second insulating layer is divided into a third insulating region and a fourth insulating region. This segmentation reduces the cumulative stress while maintaining deformation suppression at critical locations.
Solution Approach 2:
Insulating layers are selectively applied only in specific regions where they are most needed for deformation control, rather than covering the entire substrate surface. This localized approach minimizes the total stress introduced while providing targeted structural support where deformation occurs.
2Stability of the object's composition
If insulating layers are formed on the substrate surfaces, then deformation is suppressed, but warpage cancellation increases stress remaining in the substrate
Solution Approach 1:
The insulating layers are segmented into multiple discrete regions that can independently manage stress. By dividing the continuous insulating layers into separate regions (first, second, third, and fourth insulating regions), the patent prevents the cumulative stress effect while maintaining warpage suppression through strategic placement of these segmented layers.
Solution Approach 2:
The patent converts the potentially harmful effect of stress accumulation into a beneficial stress distribution pattern. By strategically placing segmented insulating regions, the natural stress from each layer is distributed and balanced, preventing the cancellation effect that leads to harmful residual stress while maintaining effective warpage control.
3Reliability
If continuous insulating layers are formed on substrate surfaces, then insulation reliability is improved, but film stress and internal stress increase
Solution Approach 1:
The continuous insulating layers are divided into multiple separate insulating regions that are strategically positioned to provide insulation where terminals are located. This segmentation reduces the total film stress and internal stress while maintaining insulation reliability through targeted coverage of terminal areas.
Solution Approach 2:
Insulating regions are concentrated specifically in areas where terminals require insulation, rather than forming continuous layers across the entire substrate. This localized insulation approach provides sufficient electrical isolation for terminals while minimizing the stress introduced by extensive insulating material coverage.
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
The configuration effectively suppresses film stress and internal stress in the substrate, reducing warpage and improving the reliability of terminal insulation, resulting in a more stable and efficient piezoelectric device.
Implementation Method 1
a piezoelectric vibrator element attached to a bottom surface of the concave portion
Data Source
AI summary
A vibrator device includes a base, a vibrator element attached to the base, and a lid housing the vibrator element between the base and itself and bonded to the base. The base has a semiconductor substrate including a first surface bonded to the lid and a second surface in a front-back relationship with the first surface, a first insulating layer placed on the first surface, first, second internal terminals placed on the first insulating layer and electrically coupled to the vibrator element, a second insulating layer placed on the second surface, and first, second external terminals placed on the second insulating layer and electrically coupled to the first, second internal terminals. The second insulating layer has a first external terminal region in which the first external terminal is placed and a second external terminal region separated from the first external terminal region, in which the second external terminal is placed.