1. Introduction With social progress and national development, international competition is becoming increasingly intensified, and the market demands higher and higher standards for products, requiring both high performance and high reliability. This means ensuring stable performance throughout the product's design lifespan. This presents a new challenge to product reliability for various industries both domestically and internationally. Reliability enhancement testing technology is an efficient and rapid method to meet this challenge. In the 1980s, while researching and developing product stress screening technology, foreign researchers noticed that the residual amount of potential defects caused by design flaws was still considerable, indicating that there was still significant room for improvement in product reliability. Simultaneously, price and development cycle are also key issues in market competition. International practical experience has proven that reliability enhancement testing is the best method to comprehensively solve these problems. The basic principle of this technology is to analyze and study product failure conditions and stress levels using the concepts of failure physics. Through this research, product defects can be exposed efficiently and quickly, leading to a rapid and genuine improvement in product reliability. Therefore, within the same timeframe, the reliability achieved using this technology is significantly higher than that of traditional methods. More importantly, it allows for early high reliability to be achieved in a short time, unlike traditional methods which require a long period of reliability enhancement, thus greatly reducing development costs. Abroad, driven by updated market perceptions of reliability and breakthroughs in key technologies, this technology developed rapidly in the 1990s. Its application has increased significantly in recent years, and its development has accelerated. However, due to the secrecy and embargo surrounding the technology, specific reports are scarce in China. In China's sensor field, research on this technology started relatively late. Currently, the mode of improving sensor reliability is still relatively traditional, involving conventional reliability testing to determine the product's reliability lifespan. Only after product failure occurs during reliability testing are design changes considered, often requiring a long time to achieve high reliability. 2. Technical Concept of Reliability Enhancement Testing Traditional reliability testing is based on methods that simulate real-world environments. Its characteristics are: simulating real-world environments, considering design margins, and ensuring test success. This testing method is time-consuming and expensive; while accelerated reliability testing aims only to identify and quantify failures and their mechanisms that lead to product degradation at the end of the product's lifespan, rather than exposing product defects. Compared with traditional reliability testing, it does not introduce new failure mechanisms. Reliability enhancement testing breaks through the technical approach of traditional reliability testing by introducing a test mechanism that rapidly induces defects into reliability testing. During the product design phase, reliability testing is conducted by applying enhanced environmental and operational stresses to induce failures and expose weaknesses in the design, thereby revealing early failures related to the product design and facilitating design modifications. This significantly shortens testing time, improves testing efficiency, and reduces testing costs. The reliability obtained using this method is much higher than that of traditional methods. More importantly, early reliability can be obtained in a short time, unlike traditional methods which require a long period of reliability growth. Reliability enhancement testing is a destructive test aimed at inducing failure. The test samples are a small number of sampled products, and the testing time is set at the end of the design cycle, before production begins, when the design, materials, components, and processes are all ready. The specific time period during the product development and production phase is shown in Figure 1. 3. Failure Mechanisms of Silicon Pressure Sensors According to reliability test results, the main failure modes of silicon pressure sensors include: parameter drift (zero-point drift, temperature drift), reduced insulation performance, core leakage, diaphragm rupture, weld cracks, bond point breakage, internal component detachment, external lead breakage, and parameter degradation. Conventional temperature, mechanical, and electrical aging tests can improve some problems, but because conventional tests cannot expose all existing defects, they cannot fundamentally achieve high reliability for the sensor. Statistical results on the failure modes and failure rates of silicon pressure sensors show that failures caused by changes in environmental factors such as temperature and humidity account for a significant proportion. The occurrence of this type of problem is mainly caused by electrochemical corrosion after the adsorption of water molecules on the chip surface. Electrochemical corrosion can occur at the interfaces between the chip and solder, bonding points, etc. These water molecules mainly come from the inherent hygroscopicity of the packaging material, as well as moisture introduced from the outside. Regardless of the moisture absorption method, the moisture absorption rate equation of the moisture absorption mechanism is: where: Cw is the concentration of water molecules absorbed by the material at time t; C∞ is the saturation concentration of water molecules absorbed by the material; Vm is the material moisture absorption rate constant. From the conventional damp heat test of silicon pressure sensors, it was found that the higher the temperature, the faster the water molecule penetration rate and the shorter the material life, i.e., Vm is a function of temperature T. Where: A is a constant at 100% relative humidity; ΔE is the failure activation energy; k is the Boltzmann constant. Under such conditions, the electrode potential of the core will change under stress. This change in potential is: where: M is the atomic weight; σ is the applied stress value; Y is Young's modulus; σ is the density; F is the Faraday constant; n is the number of molecules participating in the electrochemical reaction; Z is the strength-stress coupling factor. This corrosion increases the rate of microcrack development, exacerbating stress in certain displacements and accelerating sensor failure. Defects such as dislocations, scratches, microcracks, and damage caused during the core manufacturing process can lead to slip band changes in the local crystal structure under external load stress. When the stress exceeds the strength limit or a cumulative effect occurs, it can cause core leakage or even diaphragm rupture, resulting in an unstable strain-stress relationship in the core. In the formula: FS is the yield load; A0 is the initial cross-sectional area; σS is the yield stress. When the stress generated by the external environment is greater than or close to the yield stress of the core, it will lead to accelerated core failure. 4. Silicon Pressure Sensor Reliability Enhancement Test Profile 4.1 Selection of Enhancement Test Stress The failure mode of a sensor is determined by its failure mechanism, and the speed of the failure process is affected by stresses such as environmental conditions and operating conditions. Different stresses experienced by the sensor may produce the same or different failure mechanisms, or one failure mode may have multiple failure mechanisms. When selecting test stress, stress conditions that have a significant impact on sensor failure should be chosen. Based on a comprehensive analysis of the failure mechanism of silicon pressure sensors, reliability enhancement tests were conducted. It was determined that the sensitive stresses in the tests should be concentrated on vibration stress, temperature stress, and humidity stress. Defects in structural design, welding processes, and packaging processes can be triggered by vibration and temperature/humidity variables, while defects leading to performance degradation can be triggered by temperature/humidity variables. These test stresses can be applied individually, sequentially, or simultaneously. 4.2 Determination of Enhanced Test Stress Intensity The stress level in the reliability enhancement test of silicon pressure sensors should exceed the product's design limits, but the highest level should not exceed the sensor's failure limit stress. The stress intensity should start from a small level and gradually increase in increments until all samples fail. The technical requirements proposed by the user are the design specification's limit stress; the sensor design should be performed by the designer according to a certain design margin, which is the design limit stress; the sensor should not fail within the operating limit stress range, and the screening stress should be lower than the operating limit stress; the sensor should not experience irreversible failure within the failure limit stress range, and the reliability enhancement test stress intensity should not exceed the failure limit stress, as shown in Figure 2. 4.3 Stress levels and test times for intensification tests (1) Random vibration intensification test Vibration direction: 3 axes and 6 directions perpendicular to each other; Frequency range: 5～2000 Hz; Vibration magnitude: Initial vibration magnitude is the upper limit of the design specification, and the highest vibration magnitude is 30 g RMS; Magnitude step: 2～3 g RMS; Vibration time: 10 min per step. (2) Temperature intensification test ① High temperature test Temperature magnitude: Initial temperature magnitude is the upper limit of the design specification temperature TA, and the highest temperature magnitude is based on the abnormal failure of the sensor; Magnitude step: TA×10%; Holding time: 24～96 h per step. ② Low temperature test Temperature magnitude: Initial temperature magnitude is the lower limit of the design specification temperature TB, and the highest temperature magnitude is -70℃; Magnitude step: TB×10%; Holding time: 24～96 h per step. ③ High and low temperature shock test temperature range: The initial range is the design specification limit temperature TA, TB, and the highest range refers to the high and low temperature test requirements; the range step size is the design specification limit temperature × 10%; the holding time is 1～2 h (determined according to the sensor's heat capacity); the number of cycles is 5. In the above tests, the sensor needs to be powered on and off. (3) High temperature and high humidity enhancement test temperature range: The initial range is 60℃, and the upper limit temperature is 85℃; the range step size is 10℃; the humidity range is 93%～97%RH; the holding time is 24～96 h per step. 5 Conclusion Sensor technology is one of the fastest developing high technologies at present, and its technical level directly affects the technical level of information systems and industrial automation. Sensor reliability technology is an important basic technology that develops in sync with sensor design and production technology. The new market concept is that products not only need to have good performance indicators, but also need to have high reliability throughout the entire design life of the product. Reliability enhancement testing, as a novel testing technology, is highly efficient and low-cost. It can fundamentally improve the inherent reliability of silicon pressure sensors, quickly achieve high early reliability, thereby greatly shortening product development time, accelerating the launch of new products to the market, and increasing the market share and competitiveness of products.