Low-stress and low-temperature-rise laser welding process for sensor and detection method
By combining symmetrical welding structures and segmented laser welding processes with detection methods, the problems of low stress and low temperature rise in sensor manufacturing have been solved, improving product reliability and detection efficiency, and broadening the application scope of laser welding.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TAIYUAN AERO INSTR
- Filing Date
- 2025-12-27
- Publication Date
- 2026-04-17
AI Technical Summary
Existing laser welding technology has difficulty achieving low stress and low temperature rise in sensor manufacturing, making the welding process difficult to implement, resulting in low product qualification rate. Post-weld inspection and verification methods are also unsatisfactory, leading to misjudgments or potential quality risks.
The design incorporates a symmetrical welded structure, selects base materials with similar coefficients of thermal expansion, and employs a segmented process combining low-power positioning welding and high-power full welding. This is combined with appropriate laser welding parameters and testing methods, including airtightness, temperature shock, temperature cycling, and pressure alternation tests, to ensure low stress and low temperature rise.
This technology enables low-stress and low-temperature laser welding of sensors, improving product reliability and stability. The detection method boasts high accuracy and short detection time, broadening the application scope of laser welding in sensor research and development and manufacturing.
Smart Images
Figure CN121870261A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of sensor structural design, manufacturing process and testing verification, and specifically relates to a low-stress, low-temperature laser welding process and testing method for sensors. Background Technology
[0002] Laser welding technology plays a crucial role in sensor design and manufacturing, especially in the production of high-precision, miniaturized, and high-reliability sensors, where it holds irreplaceable advantages. However, there are significant differences in the methods used for low-stress and low-temperature-rise laser welding structural design, welding processes, and post-weld sensor testing and verification. Suboptimal laser welding structural design can make the welding process difficult to implement, leading to low product yield rates. Furthermore, inadequate post-weld testing and verification methods can result in misjudgments or potential quality issues. Summary of the Invention
[0003] This invention addresses the stress and temperature rise issues caused by laser welding during sensor design and manufacturing. It provides a low-stress, low-temperature-rise laser welding process and detection method for sensors. By combining the sensor's structural and performance characteristics, an appropriate welding structure is designed, fully utilizing laser welding parameters and processes to achieve low-stress, low-temperature-rise laser welding. Furthermore, the impact of laser welding is detected, improving the reliability and stability of the product. This makes sensor design and manufacturing processes more reliable and efficient, leading to greater user confidence in the sensors.
[0004] The technical solution of this invention is implemented as follows: In a first aspect, the present invention provides a low-stress, low-temperature-rise laser welding process for sensors, which includes the following steps: To reduce deformation and stress accumulation, the welded joints are designed to be symmetrical, and the weld gap is designed according to the same or different materials. First, perform low-power positioning welding, then perform high-power complete welding. The energy value of the low-power laser pulse is less than 50% of the energy value of the high-power laser pulse.
[0005] As a further aspect of the present invention, welding base materials with the same or similar coefficients of thermal expansion are selected to reduce differences in thermal stress.
[0006] As a further aspect of the present invention: the weld gap is <0.05 mm when welding the same material, and the weld gap is 0.05 mm to 0.1 mm when welding dissimilar materials.
[0007] As a further aspect of the present invention: low-power positioning welding, specifically: The two components need to be spot-welded together using a four-point symmetrical positioning method and a special welding fixture. The laser pulse energy should be low, and the specific value needs to be determined based on the specific product.
[0008] As a further aspect of the present invention: high-power complete welding, specifically: The laser pulse energy value for complete welding needs to be determined based on a specific material and welding structure, and must adhere to the principle that the laser pulse energy value is greater than 200% of the pulse energy value for low-power positioning welding. The laser pulse frequency should be selected within the range of 5Hz to 30Hz, depending on the specific material. The spot overlap rate is selected within the range of 50% to 85%, which needs to be determined based on whether the materials are the same or different. For the same materials, it is 60% to 85%, and for different materials, it is 50% to 60%.
[0009] Secondly, the present invention provides a sensor-based low-stress, low-temperature-rise laser welding detection method, which includes the following steps: 1) Air tightness and performance testing: After laser welding, the pressure sensor assembly is subjected to pressure up to the overload pressure point of the pressure sensor, maintained for 10 minutes, and then the pressure is removed; then the pressure sensor assembly is connected to a helium mass spectrometry leak detection system to test its leak rate, which should meet its air tightness requirements; then the pressure sensor assembly is subjected to pressure up to the maximum range pressure point of the pressure sensor, and simultaneously connected to an AC / DC current source and a digital multimeter to measure its output, which is compared with the factory data of the pressure sensor. If the rate of change is not greater than its annual stability index, it proves that it meets the requirements of low stress and low temperature rise laser welding. 2) Temperature shock test and performance testing: Place the pressure-sensitive component in a temperature shock test chamber in a non-working state and conduct a temperature shock test; after the test, restore the pressure-sensitive component to standard atmospheric conditions and conduct performance testing according to the performance testing method in step 1). Compare the results with the output value in step 1). If the rate of change is not greater than its annual stability index, it proves that it meets the requirements for low stress and low temperature rise laser welding. 3) Temperature cycling test and performance testing: Place the pressure-sensitive component in a high and low temperature test chamber in a non-working state and conduct a temperature cycling test; after the test, restore the pressure-sensitive component to standard atmospheric conditions and conduct performance testing according to the performance testing method in step 1). Compare the results with the output value in step 2). If the rate of change is not greater than its annual stability index, it proves that it meets the requirements for low stress and low temperature rise laser welding. 4) Pressure alternation test and performance testing: Connect the pressure-sensitive body component to the automatic pressure wear tester, set the high pressure value to the maximum range pressure point, and set the low pressure value to the minimum range pressure point, and conduct a pressure alternation test; then conduct performance testing according to the performance testing method in step 1), and compare it with the output value in step 3). If the rate of change is not greater than its annual stability index, it proves that it meets the requirements of low stress and low temperature rise laser welding. 5) Stability test and performance testing: Place the pressure-sensitive component under standard atmospheric conditions for no less than 48 hours; then perform performance testing according to the performance testing method in step 1), and compare it with the output value in step 4). If the rate of change is not greater than its annual stability index, it proves that it meets the requirements for low stress and low temperature rise laser welding.
[0010] As a further aspect of the present invention: the temperature shock test involves holding the temperature at high temperature for 1 hour, then rapidly switching to holding the temperature at low temperature for 1 hour, and then rapidly switching back to holding the temperature at high temperature for 1 hour. It is necessary to ensure that the temperature switching time is no more than 1 minute. The high and low temperature values are the high and low temperature limits of the sensor. The above process constitutes one cycle, and a total of 3 cycles are performed.
[0011] As a further aspect of the present invention: in the temperature cycling test, the temperature is kept at a low temperature for 1.5 hours and then switched to a high temperature for 1.5 hours. It is necessary to ensure that the average temperature change rate is not less than 10℃ / min. The above process is one cycle, and a total of 10 cycles are performed.
[0012] As a further aspect of the present invention: the pressure alternation test, the high pressure and low pressure holding time is 10s, and the number of cycles is not less than 1000.
[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention covers everything from laser welding structure design to laser welding parameter selection and process design, and finally to post-weld inspection methods. It is highly suitable for the application of low-stress, low-temperature-rise laser welding technology and inspection methods in sensor research and manufacturing processes.
[0014] 2. The laser welding structure design of this invention is highly instructive and can be applied quickly; the selection of welding parameters and process design are highly practical.
[0015] 3. The welding detection method of this invention has high accuracy and short detection time: By observing changes in sensor performance output, the effects of stress and temperature rise can be accurately and quickly detected. This greatly expands the application scope of laser welding in sensor research and manufacturing processes.
[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of a low-stress, low-temperature-rise laser welding structure for a sensor according to the present invention; Figure 2 This is a flowchart of the detection process for a sensor after low-stress, low-temperature laser welding according to the present invention. Figure 3 This is a schematic diagram of sensor performance testing according to the present invention; Figure 4This invention relates to a sensor-based low-stress, low-temperature laser welding post-testing record sheet.
[0018] The attached diagram is labeled as follows: 1-Pressure sensor; 2-Pressure interface; 3-Welding fixture; 4-Four-point symmetrical positioning point. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be described in more detail below with reference to the accompanying drawings.
[0020] In the accompanying drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of the present invention.
[0021] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0022] The following is in conjunction with the appendix Figure 1-4 The embodiments of the present invention will be described in detail below.
[0023] Example 1 This invention provides a low-stress, low-temperature laser welding process for sensors, which includes the following steps: To reduce deformation and stress accumulation, the welded joints are designed to be symmetrical, and the weld gap is designed according to the same or different materials. First, perform low-power positioning welding, then perform high-power complete welding. The energy value of the low-power laser pulse is less than 50% of the energy value of the high-power laser pulse.
[0024] Furthermore, selecting welding base materials with the same or similar coefficients of thermal expansion can reduce differences in thermal stress.
[0025] Furthermore, the weld gap should be <0.05 mm when welding the same material, and 0.05 mm to 0.1 mm when welding dissimilar materials.
[0026] Furthermore, low-power positioning welding specifically includes: The two components need to be spot-welded together using a four-point symmetrical positioning method and a special welding fixture. The laser pulse energy should be low, and the specific value needs to be determined based on the specific product.
[0027] Furthermore, high-power complete welding specifically includes: The laser pulse energy value for complete welding needs to be determined based on a specific material and welding structure, and must adhere to the principle that the laser pulse energy value is greater than 200% of the pulse energy value for low-power positioning welding. The laser pulse frequency should be selected within the range of 5Hz to 30Hz, depending on the specific material. The spot overlap rate is selected within the range of 50% to 85%, which needs to be determined based on whether the materials are the same or different. For the same materials, it is 60% to 85%, and for different materials, it is 50% to 60%.
[0028] This invention provides a method for detecting low-stress, low-temperature-rise laser welding using sensors, comprising the following steps: 1) Air tightness and performance testing: After laser welding, the pressure sensor assembly is subjected to pressure up to the overload pressure point of the pressure sensor, maintained for 10 minutes, and then the pressure is removed; then the pressure sensor assembly is connected to a helium mass spectrometry leak detection system to test its leak rate, which should meet its air tightness requirements; then the pressure sensor assembly is subjected to pressure up to the maximum range pressure point of the pressure sensor, and simultaneously connected to an AC / DC current source and a digital multimeter to measure its output, which is compared with the factory data of the pressure sensor. If the rate of change is not greater than its annual stability index, it proves that it meets the requirements of low stress and low temperature rise laser welding. 2) Temperature shock test and performance testing: Place the pressure-sensitive component in a temperature shock test chamber in a non-working state and conduct a temperature shock test; after the test, restore the pressure-sensitive component to standard atmospheric conditions and conduct performance testing according to the performance testing method in step 1). Compare the results with the output value in step 1). If the rate of change is not greater than its annual stability index, it proves that it meets the requirements for low stress and low temperature rise laser welding. 3) Temperature cycling test and performance testing: Place the pressure-sensitive component in a high and low temperature test chamber in a non-working state and conduct a temperature cycling test; after the test, restore the pressure-sensitive component to standard atmospheric conditions and conduct performance testing according to the performance testing method in step 1). Compare the results with the output value in step 2). If the rate of change is not greater than its annual stability index, it proves that it meets the requirements for low stress and low temperature rise laser welding. 4) Pressure alternation test and performance testing: Connect the pressure-sensitive body component to the automatic pressure wear tester, set the high pressure value to the maximum range pressure point, and set the low pressure value to the minimum range pressure point, and conduct a pressure alternation test; then conduct performance testing according to the performance testing method in step 1), and compare it with the output value in step 3). If the rate of change is not greater than its annual stability index, it proves that it meets the requirements of low stress and low temperature rise laser welding. 5) Stability test and performance testing: Place the pressure-sensitive component under standard atmospheric conditions for no less than 48 hours; then perform performance testing according to the performance testing method in step 1), and compare it with the output value in step 4). If the rate of change is not greater than its annual stability index, it proves that it meets the requirements for low stress and low temperature rise laser welding.
[0029] Furthermore, in the temperature shock test, the temperature is kept at high temperature for 1 hour, then quickly switched to low temperature for 1 hour, and then quickly switched back to high temperature for 1 hour. The temperature switching time must be ensured to be no more than 1 minute. The high and low temperature values are the high and low temperature limits of the sensor. The above process is one cycle, and a total of 3 cycles are performed.
[0030] Furthermore, in the temperature cycling test, the temperature is kept at a low temperature for 1.5 hours and then switched to a high temperature for 1.5 hours. The average temperature change rate must be ensured to be no less than 10℃ / min. The above process is one cycle, and a total of 10 cycles are performed.
[0031] Furthermore, in the pressure alternation test, the high pressure and low pressure are maintained for 10 seconds, and the number of cycles is not less than 1000.
[0032] This invention focuses on addressing the stress and temperature rise issues caused by laser welding during sensor design and manufacturing, as well as the challenges in detection and verification methods. Existing laser welding structural designs, welding process designs, and post-weld testing methods often fail to effectively achieve low stress and low temperature rise without understanding the sensor's structural mechanisms, thus hindering sensor design and manufacturing. This invention combines the sensor's structural and performance characteristics, designs an appropriate welding structure, fully utilizes laser welding parameters and processes to achieve low-stress and low-temperature-rise laser welding, and detects the impact of laser welding, improving the product's reliability and stability. This makes sensor design and manufacturing processes more reliable and efficient, resulting in greater user confidence in the sensors.
[0033] Example 2 This invention is based on low-stress, low-temperature pulsed laser welding technology and detection methods for sensors. The sensor laser welding structure design is the starting point, the selection of laser welding parameters and process design are crucial, and the post-weld detection method is an important guarantee of the welding process's qualification. All three parts are important and indispensable.
[0034] Sensor laser welding structure design: First, base materials with the same or similar coefficients of thermal expansion should be selected to reduce differences in thermal stress; symmetrical joints should be adopted to reduce deformation and stress accumulation caused by asymmetrical heating; the weld gap design should be optimized. When welding the same material, the weld gap should be close to 0 (<0.05 mm). When welding dissimilar materials, the weld gap design should comprehensively consider the welding performance and stress effects. If the gap is too large, the welding performance will deteriorate; if the gap is too small, the welding stress will increase. When welding dissimilar materials, a stress release gap (0.05 mm~0.1 mm) should be reserved to balance the difference in thermal expansion.
[0035] Laser welding parameter selection and process design: The welding process adopts a segmented process of "low-power positioning welding - high-power complete welding" to release welding stress in stages.
[0036] like Figure 1 As shown, the pressure sensor and pressure interface need to be laser welded together. The first step involves spot welding the two components together using a four-point symmetrical positioning method and a special welding fixture. A low laser pulse energy should be selected; the specific value needs to be determined based on the specific product. The laser pulse energy value must be less than 50% of the pulse energy value used in the second step. The laser pulse energy E is a function of the pulse power P and the duration T. E=P•T Laser pulse energy is directly related to the weld penetration depth. For a specific material and weld structure, with a given pulse power, a longer duration results in greater pulse energy, and vice versa. Generally speaking, greater pulse energy leads to greater penetration depth and stronger weld strength.
[0037] The second step requires completing the weld. The laser pulse frequency affects the material's temperature rise. A high frequency results in insufficient heat dissipation, accelerating the temperature increase, while a low frequency degrades the weld quality. Therefore, the laser pulse frequency needs to be selected based on the material and the weld structure. The weld is formed by overlapping weld spots. The overlap rate ρ is determined by the laser pulse frequency f, the relative speed v between the product and the laser beam, and the spot diameter d. This relationship can be represented by the following formula. v=d(1-ρ / 100)f In laser welding, the laser beam used in the equipment is fixed, so the speed of the worktable movement is the relative movement speed. When the spot diameter and laser pulse frequency are already determined, the speed of the worktable movement is entirely determined by the overlap rate of the weld spots.
[0038] The laser pulse energy value for a complete weld needs to be determined based on a specific material and weld structure, and must be greater than 200% of the initial pulse energy value. The laser pulse frequency is generally selected within the range of 5Hz to 30Hz, depending on the specific material. The spot overlap rate is generally selected within the range of 50% to 85%, depending on whether the materials are the same or different; for the same materials, it is generally 60% to 85%, and for dissimilar materials, it is generally 50% to 60%. By using the above-mentioned laser welding process methods and parameter selection methods, the desired low-stress, low-temperature-rise laser welding can be achieved. Whether the expected results are achieved depends on the post-laser welding inspection methods.
[0039] Post-laser welding inspection method: The inspection method includes 5 steps, such as... Figure 2 As shown, the specific steps are as follows: 1) Air tightness and performance testing: After laser welding, the pressure sensor assembly is subjected to pressure up to the overload pressure point of the pressure sensor, maintained for 10 minutes, and then the pressure is removed; subsequently, the pressure sensor assembly is connected to a helium mass spectrometry leak detection system to test its leak rate, which should meet its air tightness requirements (e.g., ≤1×10⁻⁶). -9 Pa•m 3 / s); then press Figure 3 Apply pressure to the pressure sensor assembly to the maximum range pressure point of the pressure sensor, and connect it to an AC / DC current source and a digital multimeter to measure its output. Compare the output with the factory data of the pressure sensor. If the rate of change is not greater than its annual stability index, it proves that it meets the requirements for low stress and low temperature rise laser welding. 2) Temperature shock test and performance testing: Place the pressure-sensitive component in a temperature shock test chamber in a non-operating state for a temperature shock test. The test involves holding the component at a high temperature for 1 hour, then quickly switching to a low temperature for 1 hour, and then quickly switching back to a high temperature for 1 hour. The temperature transition time must be no more than 1 minute. The high and low temperature values are the sensor's high and low temperature limits. This process constitutes one cycle, and a total of 3 cycles are performed. After the test, restore the pressure-sensitive component to standard atmospheric conditions and perform performance testing according to the performance testing method in step 1. Compare the results with the output value in step 1. If the rate of change is not greater than its annual stability index, it proves that the requirements for low stress and low temperature rise laser welding are met. 3) Temperature Cycling Test and Performance Testing: Place the pressure-sensitive component in a high and low temperature test chamber in a non-operating state for a temperature cycling test. The test involves holding the component at low temperature for 1.5 hours, then switching to high temperature for 1.5 hours, ensuring that the average temperature change rate is not less than 10℃ / min. This process constitutes one cycle, and a total of 10 cycles are performed. After the test, restore the pressure-sensitive component to standard atmospheric conditions and perform performance testing according to the performance testing method in step 1. Compare the results with the output values in step 2. If the change rate is not greater than its annual stability index, it proves that the requirements for low stress and low temperature rise laser welding are met. 4) Pressure alternation test and performance testing: Connect the pressure-sensitive body component to the automatic pressure wear tester, set the high pressure value to the maximum range pressure point, and set the low pressure value to the minimum range pressure point. The high and low pressure holding time is 10 seconds, and the number of cycles is not less than 1000. Then, perform performance testing according to the performance testing method in step 1, and compare it with the output value in step 3. If the rate of change is not greater than its annual stability index, it proves that it meets the requirements of low stress and low temperature rise laser welding. 5) Stability test and performance testing: Place the pressure-sensitive component under standard atmospheric conditions for no less than 48 hours, and then perform performance testing according to the performance testing method in step 1. Compare the results with the output value in step 4. If the rate of change is not greater than its annual stability index, it proves that it meets the requirements for low stress and low temperature rise laser welding.
[0040] Thus, the objective of this invention has been achieved.
[0041] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A low-stress, low-temperature-rise laser welding process for sensors, characterized in that, Includes the following steps: To reduce deformation and stress accumulation, the welded joints are designed to be symmetrical, and the weld gap is designed according to the same or different materials. First, perform low-power positioning welding, then perform high-power complete welding. The energy value of the low-power laser pulse is less than 50% of the energy value of the high-power laser pulse.
2. The low-stress, low-temperature laser welding process for sensors according to claim 1, characterized in that, Choose base materials with the same or similar coefficients of thermal expansion to reduce differences in thermal stress.
3. The low-stress, low-temperature laser welding process for sensors according to claim 1, characterized in that, When welding the same material, the weld gap should be <0.05 mm, and when welding dissimilar materials, the weld gap should be 0.05 mm to 0.1 mm.
4. The low-stress, low-temperature laser welding process for sensors according to claim 1, characterized in that, Low-power positioning welding, specifically: The two components need to be spot-welded together using a four-point symmetrical positioning method and a special welding fixture. The laser pulse energy should be low, and the specific value needs to be determined based on the specific product.
5. The low-stress, low-temperature laser welding process for sensors according to claim 1, characterized in that, High-power complete welding, specifically: The laser pulse energy value for complete welding needs to be determined based on a specific material and welding structure, and must adhere to the principle that the laser pulse energy value is greater than 200% of the pulse energy value for low-power positioning welding. The laser pulse frequency should be selected within the range of 5Hz to 30Hz, depending on the specific material. The spot overlap rate is selected within the range of 50% to 85%, which needs to be determined based on whether the materials are the same or different. For the same materials, it is 60% to 85%, and for different materials, it is 50% to 60%.
6. A method for detecting low-stress, low-temperature-rise laser welding using sensors, characterized in that, Includes the following steps: 1) Air tightness and performance testing: After laser welding, the pressure sensor assembly is subjected to pressure up to the overload pressure point of the pressure sensor, maintained for 10 minutes, and then the pressure is removed; then the pressure sensor assembly is connected to a helium mass spectrometry leak detection system to test its leak rate, which should meet its air tightness requirements; then the pressure sensor assembly is subjected to pressure up to the maximum range pressure point of the pressure sensor, and simultaneously connected to an AC / DC current source and a digital multimeter to measure its output, which is compared with the factory data of the pressure sensor. If the rate of change is not greater than its annual stability index, it proves that it meets the requirements of low stress and low temperature rise laser welding. 2) Temperature shock test and performance testing: Place the pressure-sensitive component in a temperature shock test chamber in a non-working state and conduct a temperature shock test; after the test, restore the pressure-sensitive component to standard atmospheric conditions and conduct performance testing according to the performance testing method in step 1). Compare the results with the output value in step 1). If the rate of change is not greater than its annual stability index, it proves that it meets the requirements for low stress and low temperature rise laser welding. 3) Temperature cycling test and performance testing: The pressure-sensitive component is placed in a high and low temperature test chamber in a non-operating state for temperature cycling test; After the test, the pressure-sensitive component was restored to standard atmospheric conditions and its performance was tested according to the performance testing method in step 1). The results were compared with the output value in step 2). If the rate of change was not greater than its annual stability index, it proved that the requirements for low stress and low temperature rise laser welding were met. 4) Pressure alternation test and performance testing: Connect the pressure-sensitive body component to the automatic pressure wear tester, set the high pressure value to the maximum range pressure point, and set the low pressure value to the minimum range pressure point, and conduct a pressure alternation test; then conduct performance testing according to the performance testing method in step 1), and compare it with the output value in step 3). If the rate of change is not greater than its annual stability index, it proves that it meets the requirements of low stress and low temperature rise laser welding. 5) Stability test and performance testing: Place the pressure-sensitive component under standard atmospheric conditions for no less than 48 hours; then perform performance testing according to the performance testing method in step 1), and compare it with the output value in step 4). If the rate of change is not greater than its annual stability index, it proves that it meets the requirements for low stress and low temperature rise laser welding.
7. The sensor low-stress, low-temperature-rise laser welding detection method according to claim 6, characterized in that, The temperature shock test involves holding the temperature at a high temperature for 1 hour, then rapidly switching to a low temperature for 1 hour, and then rapidly switching back to a high temperature for 1 hour. The temperature switching time must be no more than 1 minute. The high and low temperature values are the high and low temperature limits of the sensor. The above process constitutes one cycle, and a total of 3 cycles are performed.
8. The sensor low-stress, low-temperature-rise laser welding detection method according to claim 6, characterized in that, The temperature cycling test involves holding the temperature at a low temperature for 1.5 hours and then switching to holding the temperature at a high temperature for 1.5 hours. The average temperature change rate must be no less than 10℃ / min. This process constitutes one cycle, and a total of 10 cycles are performed.
9. The sensor low-stress, low-temperature-rise laser welding detection method according to claim 6, characterized in that, The pressure alternation test involves maintaining high and low pressure for 10 seconds each, with a cycle count of no less than 1000 times.