Pressure sensor with high temperature stability
By etching patterned grooves on the glass substrate and setting a sealing ring, the stress problem of silicon-glass bonded pressure sensors under temperature changes is solved, thereby improving the accuracy and stability of the pressure sensors.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-04
- Publication Date
- 2026-04-07
AI Technical Summary
Existing silicon-glass bonded pressure sensors suffer from hysteresis and drift due to the mismatch in thermal expansion coefficients between glass and silicon when the temperature changes, thus reducing accuracy.
Patterned grooves are etched on the glass substrate, and different patterns are designed to adapt to the thermal expansion direction of the silicon wafer. By setting sealing rings around the central through-hole and edge sealing rings, the stress effect during temperature changes is reduced.
Without increasing costs, the test accuracy of the pressure sensor is significantly improved, the impact of temperature changes on stress is reduced, and the stability of the sensor is enhanced.
Smart Images
Figure CN224095294U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of pressure sensor technology, specifically relating to a high-temperature stability pressure sensor. Background Technology
[0002] In existing silicon-glass bonded pressure sensors, the silicon structure and glass are anodicly bonded together over an entire surface. When the temperature changes, the different coefficients of thermal expansion of the glass and silicon cause stress at the glass-silicon bonding surface, affecting the performance indicators of high-precision pressure sensors, such as hysteresis and drift.
[0003] There is an urgent need for a new type of pressure sensor that can significantly reduce the stress caused by thermal expansion when the temperature changes, reduce the influence of temperature, and thus improve the accuracy of the pressure sensor. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention proposes a high-temperature stability pressure sensor, which includes: a glass substrate and a silicon sensing structure; the silicon sensing structure is bonded to the glass substrate wafer to form a measurement cavity; the glass substrate has a central through hole that communicates with the measurement cavity; and patterned grooves are etched on the glass substrate.
[0005] Preferably, a central sealing ring is provided around the central through hole, and the central through hole is located directly below the pressure-sensitive structure.
[0006] Furthermore, the graphic grooves are multiple rectangular recesses surrounding the central sealing ring.
[0007] Preferably, the glass base is provided with an edge sealing ring.
[0008] The beneficial effects of this utility model are as follows: By etching patterned grooves on the glass base, this utility model improves the stress effect of the pressure sensor under temperature changes without significantly increasing the cost, thereby improving the testing accuracy of the pressure sensor and showing good application prospects. Attached Figure Description
[0009] Figure 1 This is a schematic diagram of a preferred embodiment of the high-temperature stability pressure sensor structure in this utility model;
[0010] Figure 2 This is a top view of a preferred embodiment of the glass base in this utility model;
[0011] Figure 3 This is a side view of a preferred embodiment of the glass base in this utility model;
[0012] Figure 4 This is a schematic diagram of the stress direction of a preferred embodiment of the present invention;
[0013] Figure 5 This is a graphical groove pattern of another preferred embodiment of the present invention;
[0014] Figure 6 This is another preferred embodiment of the graphic groove pattern in this utility model. Detailed Implementation
[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0016] This invention proposes a high-temperature-stability pressure sensor, such as... Figure 1 As shown, the pressure sensor includes: a glass substrate and a silicon sensing structure; the silicon sensing structure is bonded to the glass substrate wafer to form a measurement cavity; the glass substrate has a central through hole that communicates with the measurement cavity; and patterned grooves are etched on the glass substrate.
[0017] Pressure sensors with an accuracy of 0.05% or higher are particularly sensitive to temperature changes. When the temperature changes, due to differences in the coefficient of thermal expansion, the stress in the horizontal direction of the contact surface (bonding surface) can cause distortion of the top thin film of the silicon sensitive structure of the pressure sensor, resulting in a deterioration in the pressure sensor's hysteresis, repeatability, and other performance indicators. Therefore, this invention selects different patterns based on the tangential direction (thermal expansion direction) of the silicon wafer of the pressure sensor, and then designs patterned grooves on the glass substrate according to the patterns.
[0018] In a preferred embodiment of this utility model, a central sealing ring is provided around the central through hole, and the central through hole is located directly below the pressure-sensitive structure.
[0019] In a preferred embodiment of this utility model, such as Figure 2 , Figure 3 As shown, if the tangential direction of the pressure sensor silicon wafer is... <100> The graphic grooves are multiple rectangular grooves surrounding the central sealing ring, and the number of rectangular grooves can be as large as possible while ensuring bonding strength.
[0020] In a preferred embodiment of this utility model, an edge sealing ring is provided at the edge of the glass base.
[0021] like Figure 4As shown, the graphic groove design of the glass base of this utility model has the effect of suppressing thermal expansion stress. When the temperature changes, there is room to accommodate the lateral expansion of the glass, the stress in the horizontal direction can be greatly reduced, the compression is reduced, and the stress effect on the bonding surface is reduced.
[0022] The patterned grooves on the silicon wafer of a pressure sensor differ depending on its tangential orientation. For example, on some other silicon wafer orientations of pressure sensors, the pattern might look like this: Figure 5 , Figure 6 As shown.
[0023] In summary, this invention improves the stress response of pressure sensors by etching patterned grooves on a glass substrate without significantly increasing costs, thereby enhancing the testing accuracy of the pressure sensors and demonstrating promising application prospects.
[0024] The above-described embodiments further illustrate the purpose, technical solution, and advantages of this utility model. It should be understood that the above-described embodiments are merely preferred embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made to this utility model within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A high-temperature-stability pressure sensor, characterized in that, include: Glass substrate and silicon-sensitive structure; The silicon-sensitive structure is bonded to the glass substrate wafer and forms a measurement cavity; The glass base has a central through hole that connects to the measuring cavity; patterned grooves are etched on the glass base.
2. The high-temperature stability pressure sensor according to claim 1, characterized in that, A central sealing ring is provided around the central through hole, and the central through hole is located directly below the pressure-sensitive structure.
3. A high-temperature stability pressure sensor according to claim 2, characterized in that, The graphic grooves are multiple rectangular recesses surrounding the central sealing ring.
4. A high-temperature stability pressure sensor according to claim 1, characterized in that, An edge sealing ring is provided at the edge of the glass base.