Glass-based silicon strain gauge
By employing glass-based silicon strain gauges with consistent thermal expansion coefficients, the problem of thermal mismatch in glass micro-fused silicon strain gauges at high temperatures was solved, improving the accuracy and high-temperature performance of the pressure sensor.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HANGZHOU HONGMAI MICROELECTRONICS CO LTD
- Filing Date
- 2025-06-23
- Publication Date
- 2026-05-05
AI Technical Summary
Existing glass micro-fused silicon strain gauges suffer from thermal mismatch at high temperatures due to the difference in thermal expansion coefficients between the glass sintered layer and the stainless steel diaphragm, which affects the high-temperature performance of the pressure sensor.
A glass-based silicon strain gauge is used, with a glass diaphragm. The thermal expansion coefficients of the glass diaphragm and the glass sintered layer are basically the same. By distributing glass through holes at the edge of the diaphragm to concentrate stress, the sensitivity of pressure sensing is improved.
The thermal mismatch problem has been eliminated, improving the accuracy and high-temperature performance of the pressure sensor.
Smart Images
Figure CN224202610U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of pressure sensors, specifically to a glass-based silicon strain gauge. Background Technology
[0002] Silicon strain gauges primarily consist of a glass micro-melted pressure sensor core. Their main advantages are excellent medium resistance and strong overload capacity, making them suitable for high-pressure measurements in automotive and industrial applications. They show significant advantages in high-pressure applications such as diesel common rail systems, loader hydraulics, and fuel pumps. For measurements above 500 kPa, they can replace diffused silicon pressure sensors. They are made by high-temperature sintering of glass powder; after the glass melts at temperatures above 500°C, the silicon strain gauge is sintered onto a 17-4PH stainless steel sensitive elastomer.
[0003] Conventional glass micro-fused silicon strain gauges bond the strain gauge and stainless steel diaphragm by sintering a glass slurry. The coefficient of thermal expansion of the sintered glass layer is approximately 3 x 10⁻⁶. -6 At / °C, the coefficient of thermal expansion of the stainless steel diaphragm is approximately 2 x 10⁻⁶. -5 The temperature is -60°C, therefore there is a thermal mismatch between the glass sintered layer and the stainless steel diaphragm. The difference in the coefficient of thermal expansion will cause the pressure sensor's high-temperature performance to degrade, thus affecting the sensor's use at high temperatures. Summary of the Invention
[0004] To overcome the shortcomings of existing technologies, this invention proposes a glass-based silicon strain gauge. The diaphragm is made of glass, and the thermal expansion coefficients of the glass diaphragm and the glass sintered layer are basically the same, so there is no thermal mismatch. At the same time, the glass through holes are distributed at the edge of the diaphragm, which can help stress concentration, improve the sensitivity of the glass diaphragm to sensing pressure, and thus improve the accuracy of the pressure sensor.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0006] A glass-based silicon strain gauge includes: a glass substrate, a central diaphragm, a glass via, a glass sintered layer, a silicon strain gauge core, gold wires, front pads, front leads, back pads, and back leads. The glass substrate is rectangular or circular, with a side length or diameter of 1-50 mm and a thickness of 200-1000 μm. The glass via is made of metal.
[0007] Preferably, the central film is located at the center of the glass substrate, with a side length or diameter of 0.5~30mm and a thickness of 20~200μm, and the central film is formed by etching the glass substrate on the upper and lower surfaces.
[0008] Preferably, the glass through holes are evenly distributed on the edge of the central diaphragm, 10-100 μm away from the edge. The through holes are round or square, with a side length or diameter of 10-200 μm. The glass through holes penetrate the central diaphragm, and the metal on the sidewall of the glass through holes is copper, gold, or other metals.
[0009] Preferably, the glass sintered layer is formed by printing and sintering glass paste, located at the center of the central diaphragm, and the size of the glass sintered layer is larger than that of the silicon strain gauge core, with a side length of 500~2000μm and a thickness of 2~20μm.
[0010] Preferably, the silicon strain gauge core is a half-bridge silicon strain gauge located on a glass sintered layer. The silicon strain gauge core includes a short side length and a long side length, with the short side length being 200~500μm, the long side length being 400~1000μm, and the thickness being 3~20μm.
[0011] Preferably, the gold wire has a diameter of 25 μm and is used to connect the electrical signals of the silicon strain gauge and the front pad.
[0012] Preferably, the front pad is located on the central diaphragm, and is square or circular with a side length or diameter of 100~500μm. It is used to form solder joints and is soldered to gold wires. The composition of the front pad is copper, aluminum or gold.
[0013] Preferably, the front lead is located on the central diaphragm, with a linewidth of 10~100μm. The front lead connects the electrical signals of the front pad and the glass via. The composition of the front lead is copper, aluminum or gold.
[0014] Preferably, the back pad is located on the back side of the glass substrate, and is square or circular with a side length or diameter of 100~500μm. It is used to connect the electrical signal on the front side to the external signal. The composition of the back pad is copper, aluminum or gold.
[0015] Preferably, the back lead is located on the back of the central diaphragm, with a line width of 10~100μm. The back lead connects the glass via and the back pad with electrical signals. The back lead is composed of copper, aluminum or gold.
[0016] The beneficial effects of using this utility model are as follows:
[0017] 1. The thermal expansion coefficients of the central diaphragm and the glass sintered layer are basically the same, and there is no thermal mismatch. At the same time, the glass through holes are distributed at the edge of the central diaphragm, which can help stress concentration, improve the sensitivity of the glass diaphragm to sense pressure, and thus improve the accuracy of the pressure sensor.
[0018] These features and advantages of the present invention will be disclosed in detail in the following specific embodiments and accompanying drawings. Attached Figure Description
[0019] The present invention will be further described below with reference to the accompanying drawings:
[0020] Figure 1 This is a front structural schematic diagram of a glass-based silicon strain gauge proposed in this utility model;
[0021] Figure 2 This is a schematic diagram of the back structure of a glass-based silicon strain gauge proposed in this utility model;
[0022] Figure 3 This is a front structural schematic diagram of another glass-based silicon strain gauge proposed in this utility model;
[0023] Figure 4 This is a schematic diagram of the back structure of another glass-based silicon strain gauge proposed in this utility model;
[0024] Figure 5 This is a schematic cross-sectional view of a glass-based silicon strain gauge proposed in this utility model. Detailed Implementation
[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0026] The concepts involved in this application will first be explained with reference to the accompanying drawings. It should be noted that the following explanation of each concept is only to make the content of this application easier to understand and does not imply any limitation on the scope of protection of this application.
[0027] Example 1:
[0028] Reference Figure 1 As shown, a glass-based silicon strain gauge 100 includes: a glass substrate 101, a central diaphragm 102, a glass through-hole 103, a glass sintered layer 104, a silicon strain gauge core 105, gold wires 106, front pads 107, front leads 108, back pads 109, and back leads 110. The glass substrate 101 is rectangular, with a side length of 1-50 mm and a thickness of 200-1000 μm. The central diaphragm 102 is located at the center of the glass substrate 101, with a side length of 0.5-30 mm and a thickness of 20-200 μm. The central diaphragm 102 is formed by etching the upper and lower surfaces of the glass substrate 101.
[0029] Glass vias 103 are uniformly distributed along the edge of the central diaphragm 102, at a distance of 10-100 μm from the edge. The glass vias 103 are circular holes with a diameter of 10-200 μm. The glass vias 103 penetrate the central diaphragm 102, and the metal on the sidewall of the glass vias 103 is copper, gold, or other metals.
[0030] The glass sintered layer 104 is formed by printing and sintering glass paste, and is located at the center of the central diaphragm 102. Its size should be larger than that of the silicon strain gauge core 105, with a side length of 500~2000μm and a thickness of 2~20μm. The silicon strain gauge core 105 is a half-bridge silicon strain gauge, located on the glass sintered layer 104 of the central diaphragm 102.
[0031] The silicon strain gauge core 105 includes a short side 1051 and a long side 1052. The short side 1051 has a length of 200-500 μm, the long side 1052 has a length of 400-1000 μm, and the thickness is 3-20 μm. The gold wire 106 has a diameter of 25 μm and is used to connect the silicon strain gauge core 105 and the front pad 107 for electrical signals.
[0032] The front pads 107 are located on the central diaphragm 102 and are circular, with a total of four pads, each with a diameter of 100~500μm. They are used to form solder joints and are soldered to the gold wires 106. The composition of the front pads 107 is copper, aluminum, or gold, or a combination of copper, aluminum, and gold.
[0033] The front lead 108 is located on the central diaphragm 102, with a linewidth of 10~100μm. The front lead 108 connects the front pad 107 and the glass via 103 for electrical signals. The front lead 108 is composed of copper, aluminum, or gold, or a combination of copper, aluminum, and gold.
[0034] refer to Figure 2 As shown, the back pads 109 are located on the back side of the glass substrate 101. They are circular, with a total of four pads, and their side length or diameter is 100~500μm. They are used to connect the electrical signals on the front side to external signals. The back pads 109 are made of copper, aluminum, or gold, or a combination of copper, aluminum, and gold.
[0035] The back lead 110 is located on the back side of the central diaphragm 102, with a line width of 10~100μm. The back lead 110 connects the glass via 103 and the back pad 109 for electrical signals. The back lead 110 is made of copper, aluminum, or gold, or a combination of copper, aluminum, and gold.
[0036] Example 2:
[0037] Reference Figure 3 and Figure 4As shown, the glass-based silicon strain gauge 100, the glass substrate 101, and the central diaphragm 102 are circular. The glass substrate 101 has a diameter of 1–50 mm and a thickness of 200–1000 μm. The central diaphragm 102 is located at the center of the glass substrate 101, has a diameter of 0.5–30 mm, and a thickness of 20–200 μm. The central diaphragm 102 is formed by etching the upper and lower surfaces of the glass substrate 101.
[0038] Reference Figure 5 As shown, the glass substrate 101 has a thickness of 200~1000μm. The central diaphragm 102 is located at the center of the glass substrate 301 and has a thickness of 20~200μm. Glass vias 103 are uniformly distributed at the edge of the central diaphragm 102, 10~100μm from the edge. The glass vias 103 are circular holes with a diameter of 10~200μm. The glass vias 103 penetrate the central diaphragm 102. The metal of the sidewall of the glass vias 103 is copper, gold, or other metals. The thermal expansion coefficients of the central diaphragm 102 and the glass sintered layer 104 are basically the same, so there is no thermal mismatch. At the same time, the distribution of the glass vias 103 at the edge of the central diaphragm 102 can help with stress concentration, improve the sensitivity of the central diaphragm 102 to sense pressure, and thus improve the accuracy of the pressure sensor.
[0039] The above are merely specific embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Those skilled in the art should understand that this utility model includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of this utility model will be included within the scope of the claims.
Claims
1. A glass-based silicon strain gauge, characterized in that, include: The components include a glass substrate, a central diaphragm, a glass via, a glass sintered layer, a silicon strain gauge core, gold wires, front pads, front leads, back pads, and back leads. The glass substrate is rectangular or circular with a side length or diameter of 1-50 mm and a thickness of 200-1000 μm. The glass via is made of metal.
2. The glass-based silicon strain gauge according to claim 1, characterized in that: The central film is located at the center of the glass substrate, with a side length or diameter of 0.5~30mm and a thickness of 20~200μm, and is formed by etching the glass substrate on the upper and lower surfaces.
3. The glass-based silicon strain gauge according to claim 1, characterized in that: The glass through holes are evenly distributed on the edge of the central diaphragm, 10-100 μm away from the edge. The glass through holes are round or square, with a side length or diameter of 10-200 μm. The glass through holes penetrate the central diaphragm, and the metal on the sidewall of the glass through holes is copper or gold.
4. A glass-based silicon strain gauge according to claim 1, characterized in that: The glass sintered layer is formed by printing and sintering glass paste, and is located at the center of the central diaphragm. The size of the glass sintered layer is larger than that of the silicon strain gauge core, with a side length of 500~2000μm and a thickness of 2~20μm.
5. A glass-based silicon strain gauge according to claim 1, characterized in that: The silicon strain gauge core is a half-bridge silicon strain gauge located on a glass sintered layer. The silicon strain gauge core includes a short side length and a long side length, with the short side length being 200~500μm and the long side length being 400~1000μm. The thickness of the silicon strain gauge core is 3~20μm.
6. A glass-based silicon strain gauge according to claim 1, characterized in that: The gold wire has a diameter of 25 μm and is used to connect the electrical signals between the silicon strain gauge and the front pad.
7. A glass-based silicon strain gauge according to claim 1, characterized in that: The front pad is located on the central diaphragm and is square or circular with a side length or diameter of 100~500μm. It is used to weld with gold wire to form a solder joint. The composition of the front pad is copper, aluminum or gold.
8. A glass-based silicon strain gauge according to claim 1, characterized in that: The front lead is located on the central diaphragm and has a line width of 10~100μm. The front lead connects the electrical signals of the front pad and the glass via. The front lead is composed of copper, aluminum or gold.
9. A glass-based silicon strain gauge according to claim 1, characterized in that: The back pad is located on the back side of the glass substrate and is square or circular with a side length or diameter of 100~500μm. It is used to connect the electrical signal on the front side to the external signal. The composition of the back pad is copper, aluminum or gold.
10. A glass-based silicon strain gauge according to claim 1, characterized in that: The back lead is located on the back of the central diaphragm, with a line width of 10~100μm. The back lead connects the glass via and the back pad with electrical signals. The back lead is made of copper, aluminum or gold.