Chip package reliability accelerated test and life prediction method based on multi-physics coupling

Abstract

The application discloses a multi-physical field coupling chip package reliability accelerated test and life prediction method, which comprises the following steps: first, a temperature cycle-vibration-humidity-power cycle-thermal shock-electromagnetic radiation field five-dimensional integrated stress test environment is constructed, and each stress parameter is accurately set and applied according to the actual working condition; then, a five-dimensional accelerated test model is established by weighting and fusing each single stress acceleration model, and the weight coefficient is determined based on the actual working condition influence weight; subsequently, finite element simulation is adopted to analyze the stress, heat conduction and electromagnetic coupling effect of the packaging structure, and the acceleration factor is corrected in real time by combining the physical failure (PoF) algorithm; finally, a packaging level life digital image containing failure modes and failure time distribution is constructed based on multi-dimensional data, and reliability test and life prediction are realized. The test time is less than or equal to 200 hours, the life prediction accuracy is greater than or equal to 90%, and the method is suitable for mainstream packaging types such as BGA, CSP, SiP and FlipChip, thereby providing an efficient solution for chip package reliability evaluation.

Description

Technical Field

[0001] This invention relates to the field of chip packaging reliability testing and lifetime assessment technology, specifically to a method for accelerated chip packaging reliability testing and lifetime prediction using multi-physics coupling. Background Technology

[0002] As a crucial carrier connecting chips to external circuits, chip packaging directly determines the overall operational stability and lifespan of electronic devices. In practical applications, chip packaging often faces the combined effects of multiple physical fields, such as temperature cycling, vibration, humidity erosion, power thermal shock, and electromagnetic radiation. The coupling effect of these stresses can accelerate the failure of the packaging structure, leading to problems such as solder joint fatigue cracking, bond wire detachment, packaging material aging, and interface delamination.

[0003] However, existing accelerated testing technologies for chip package reliability have significant drawbacks: The stress type is singular and cannot reproduce complex working conditions: Traditional tests often use a single stress (such as temperature cycling or vibration only) or a simple stress combination within three dimensions (such as temperature cycling-vibration-humidity), ignoring the damage caused by instantaneous temperature fluctuations from power cycling thermal shock and the impact of electromagnetic radiation on the performance of packaging materials. This results in a large deviation between the test environment and the actual application scenario, and it is impossible to truly reproduce the actual failure mode of chip packaging.

[0004] Long testing cycles and low efficiency: Existing technologies do not fully utilize the acceleration effect of multi-physics coupling, and the acceleration factor remains fixed. They do not consider the dynamic changes in failure mechanisms during the testing process, resulting in testing cycles that are usually over 1,000 hours, which seriously affects chip development cycles and mass production progress.

[0005] Low lifetime prediction accuracy and poor matching: Traditional methods rely on empirical formulas or single failure models to calculate acceleration factors, without combining finite element simulation to accurately analyze the stress, heat conduction and other characteristics of the package structure, and without real-time correction of model parameters based on the Physics of Failure (PoF) theory. This results in a large deviation between lifetime prediction results and actual failure conditions, with accuracy generally below 70%, which is difficult to meet the accurate reliability assessment requirements of industrial applications.

[0006] Therefore, there is an urgent need for a chip package reliability acceleration testing and lifetime prediction method that can reproduce complex operating conditions, shorten the testing cycle, and improve prediction accuracy, in order to overcome the shortcomings of existing technologies. Summary of the Invention

[0007] (a) Technical problems to be solved To address the three core problems of existing chip packaging reliability testing technologies—namely, "single stress type, long test cycle, and low lifetime prediction accuracy"—this invention provides a multi-physics field coupled chip packaging reliability accelerated testing and lifetime prediction method. By constructing a five-dimensional comprehensive stress test environment, real-time correction of acceleration factors, and establishment of a lifetime digital profile, it achieves accurate reproduction of complex working conditions, significantly shortens the test cycle, and significantly improves prediction accuracy.

[0008] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: A method for accelerating reliability testing and lifetime prediction of chip packages using multi-physics coupling includes the following steps: Constructing a five-dimensional comprehensive stress accelerated testing environment: The five-dimensional comprehensive stress includes temperature cycling stress, vibration stress, humidity stress, power cycle thermal shock stress, and electromagnetic radiation field stress. Each stress is applied collaboratively through dedicated equipment to ensure that the stress field uniformly covers the entire chip package area. Temperature cycling stress is applied through a high and low temperature test chamber, with the temperature range controlled between -55℃ and 150℃. The cycle period is set to 30min-120min (heating phase accounts for 30%-40%, high temperature holding phase accounts for 20%-30%, and cooling phase accounts for 30%-40%), to simulate the temperature change of the chip during start-up, shutdown, and switching between high and low temperature environments. Vibration stress is applied through an electromagnetic vibration table, with a frequency range of 10Hz-2000Hz (covering low-frequency resonance and high-frequency vibration scenarios), an acceleration of 5g-30g, and the vibration direction can be selected as single-axis or multi-axis coordinated vibration according to the actual working conditions. Humidity stress is controlled in conjunction with a constant temperature and humidity chamber, with a relative humidity range of 30%-95%. Humidity changes are synchronized with temperature cycling stress to avoid test errors caused by sudden humidity changes. Power cycle thermal shock stress is achieved through the collaboration of built-in heating elements (such as heating resistors) and external heat dissipation modules (such as micro cooling fans and water cooling plates). The thermal shock temperature change rate is 5℃ / s-20℃ / s, and the temperature fluctuation range of a single thermal shock is 25℃-125℃. The cycle period is matched with the actual working power switching cycle of the chip (1min-10min / cycle). Electromagnetic radiation field stress is applied in conjunction with a microwave signal generator and a horn antenna, with a frequency range of 1GHz-10GHz (covering the electromagnetic operating frequency band of mainstream electronic devices), a radiation intensity of 10V / m-100V / m, and a radiation direction perpendicular to the chip package surface, ensuring that the electromagnetic field acts uniformly on the package structure.

[0009] Establishing a five-dimensional accelerated testing model: The five-dimensional accelerated testing model is constructed by weighted fusion of accelerated models of individual stresses. The specific steps are as follows: A temperature cycling stress acceleration model (based on the Arrhenius equation), a vibration stress acceleration model (based on Miner's linear cumulative damage theory), a humidity stress acceleration model (based on the Peck model), a power cycling thermal shock acceleration model (based on the Coffin-Manson equation), and an electromagnetic radiation field acceleration model (based on field-induced aging theory) were established respectively. The influence weight of each individual stress on chip packaging failure was obtained through orthogonal experiments. The weight coefficient of each stress was determined by the analytic hierarchy process (the sum of the weight coefficients is 1). The weight coefficients are as follows: temperature cycling stress 0.25-0.35, vibration stress 0.15-0.25, humidity stress 0.10-0.20, power cycling thermal shock stress 0.20-0.30, and electromagnetic radiation field stress 0.05-0.15. By weighting and fusing each individual stress acceleration model with its corresponding weight coefficient, a five-dimensional acceleration testing model is obtained, the model expression of which is: in, The total acceleration factor, Let be the weighting coefficient for the i-th type of stress. is a single acceleration factor for the i-th stress.

[0010] The acceleration factor is corrected in real time using finite element simulation and the Physics of Failure (PoF) algorithm. Finite element simulation: A three-dimensional structural model of the chip package (including core components such as chip, bonding wires, solder joints, encapsulant, and substrate) is established using ANSYS or ABAQUS software. The mesh generation accuracy is controlled within 0.1mm-0.5mm. Five-dimensional comprehensive stress parameters are input as boundary conditions. The stress distribution, heat conduction path, and electromagnetic coupling effect of the chip package structure are simulated and analyzed. The simulation accuracy error is ≤5%. Key physical quantities such as solder joint strain, encapsulation material temperature gradient, and interface shear stress are output. Physics of Failure (PoF) algorithm: Based on key failure mechanisms in chip packaging (including solder joint fatigue failure, bond wire detachment, packaging material aging, and interface delamination), establish PoF models corresponding to each failure mechanism: For weld fatigue failure, the Coffin-Manson equation combined with the weld strain amplitude obtained from simulation is used to calculate the weld fatigue life. To address the issue of bond wire detachment, we analyze the risk of interface delamination between the bond wire and the chip / substrate based on an interface adhesion strength degradation model and thermal conduction simulation data. To address the aging of packaging materials, the material performance degradation rate is calculated based on a material thermo-oxidative aging kinetic model and combined with temperature and humidity simulation data. For interface delamination, the delamination propagation rate is determined based on fracture mechanics theory and the interface stress intensity factor obtained from stress simulation. Real-time correction: The key physical quantities output by the finite element simulation are input into the PoF model, and the acceleration factor correction coefficients corresponding to each failure mechanism are calculated in real time. The total acceleration factor in the five-dimensional accelerated test model is dynamically corrected. The correction cycle is synchronized with the temperature cycling stress cycle cycle (30min-120min / cycle) to ensure that the acceleration factor matches the actual failure process.

[0011] Establish a digital profile of chip package-level lifespan to accelerate reliability testing and lifespan prediction: Data Acquisition: During the accelerated testing process, the temperature, strain, and electrical performance parameters of the chip package are collected in real time using equipment such as infrared thermal imagers, strain gauges, and impedance analyzers. Combined with finite element simulation data and PoF algorithm calculation results, a multi-dimensional test dataset is formed. Lifetime digital profile construction: Based on a multi-dimensional test dataset, integrate the failure mode types of chip packaging (such as solder joint fatigue failure, interface delamination, etc.), failure time distribution (fitted with Weibull distribution), remaining lifetime estimate (based on the conversion of the corrected acceleration factor and test duration) and reliability confidence interval (confidence level 95%) to establish a package-level lifetime digital profile. Lifetime prediction: Output the expected lifetime of the chip package under actual working conditions through lifetime digital profiling, with prediction accuracy ≥90% and total test duration ≤200 hours.

[0012] (III) Beneficial Effects Compared with existing technologies, this invention provides a method for accelerated reliability testing and lifetime prediction of chip packages using multi-physics coupling, which has the following advantages: 1. Reproducing complex working conditions and matching actual failure modes: This invention introduces power cycling thermal shock and electromagnetic radiation field for the first time, constructing a five-dimensional comprehensive stress environment of temperature cycling-vibration-humidity-power cycling thermal shock-electromagnetic radiation field, accurately reproducing the multi-physics field coupling working conditions of chip packaging in actual applications, solving the problem that traditional single stress test cannot simulate real failure scenarios, and improving the matching degree between test results and actual failure modes to more than 85%. 2. Significantly shorten the testing cycle and improve testing efficiency: Through the synergistic acceleration effect of multi-physics coupling, combined with finite element simulation and PoF algorithm to correct the acceleration factor in real time, the traditional testing cycle of more than 1,000 hours is compressed to less than 200 hours, the testing efficiency is improved by 5 times, and the chip R&D and mass production verification cycle is significantly shortened. 3. Improve lifetime prediction accuracy and support reliability design: Based on the precise analysis of failure physics theory and finite element simulation, the acceleration factor is dynamically corrected, a multi-dimensional digital lifetime profile is established, and the lifetime prediction accuracy reaches more than 90%, providing accurate data support for chip packaging structure optimization, material selection and reliability design. 4. Wide range of applications and strong compatibility: It is suitable for various mainstream chip packaging types such as BGA, CSP, SiP, and FlipChip. The five-dimensional stress parameters and weighting coefficients can be flexibly adjusted according to the actual working conditions of different chips, making it highly compatible and practical. Detailed Implementation

[0013] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] Example 1: Accelerated Reliability Testing and Lifetime Prediction of BGA Packaged Chips Test sample: The chip is packaged using a ball grid array (BGA), the solder joint material is Sn-Ag-Cu alloy, the encapsulant is epoxy resin, the substrate is FR-4 material, and the chip size is 10mm×10mm×1mm.

[0015] Five-dimensional comprehensive stress parameter settings: Temperature cycling stress: -40℃ to 125℃, cycle period 60min (heating up for 20min, holding high temperature for 10min, cooling down for 20min, holding low temperature for 10min); Vibration stress: 50Hz-1500Hz, acceleration 15g, uniaxial vertical vibration; Humidity stress: relative humidity 60%-90%, changes synchronously with temperature cycling stress; Power cycle thermal shock stress: thermal shock temperature change rate 10℃ / s, temperature fluctuation range 40℃-110℃, cycle period 5min / time; Electromagnetic radiation field stress: frequency 5GHz, radiation intensity 50V / m.

[0016] Five-dimensional accelerated testing model construction: The weighting coefficients for each stress were determined through orthogonal experiments: 0.3 for temperature cycling stress, 0.2 for vibration stress, 0.15 for humidity stress, 0.25 for power cycling thermal shock stress, and 0.1 for electromagnetic radiation field stress. The weighted fusion of each individual stress acceleration model yielded the overall acceleration model.

[0017] Finite element simulation and PoF algorithm correction: A three-dimensional model of the BGA package was established using ANSYS software with a mesh generation accuracy of 0.3 mm. The simulation yielded a maximum strain amplitude of 0.005 at the solder joint, a maximum temperature of 118℃ for the encapsulant, and an interfacial shear stress of 25 MPa. Based on the PoF algorithm, the Coffin-Manson equation was used to calculate a correction factor of 1.2 for solder joint fatigue failure, and the total acceleration factor was corrected in real time.

[0018] Test Results and Lifetime Prediction: The accelerated testing lasted 180 hours, and the main failure mode of the chip package was observed to be solder joint fatigue cracking. The failure time distribution was fitted to a Weibull distribution (shape parameter 2.8, scale parameter 220 hours) by the life digital profile. The expected life under actual working conditions was 10,000 hours, with a prediction accuracy of 92% (8% error compared with the actual life).

[0019] Example 2: Accelerated Reliability Testing and Lifetime Prediction of FlipChip Packaged Chips Test sample: Flip-chip packaged chip with micro solder joints (50μm in diameter), encapsulation material is underfill adhesive, chip size is 8mm×8mm×0.8mm.

[0020] Five-dimensional comprehensive stress parameter settings: Temperature cycling stress: -55℃ to 150℃, cycle time 90min; Vibration stress: 10Hz-2000Hz, acceleration 25g, multi-axis coordinated vibration; Humidity stress: relative humidity 30%-95%; Power cycle thermal shock stress: thermal shock temperature change rate 15℃ / s, temperature fluctuation range 25℃-125℃, cycle period 3min / time; Electromagnetic radiation field stress: frequency 8GHz, radiation intensity 80V / m.

[0021] Test Results and Lifetime Prediction: The accelerated testing duration is 200 hours, with the main failure mode being interface layering; the life digital profile output shows an expected lifespan of 8500 hours under actual working conditions, with a prediction accuracy of 91%, meeting the needs of industrial applications.

[0022] Experimental Example: Comparative Experiment of the Invention and Traditional Testing Methods Selected BGA packaged chips of the same type, the method of this invention was compared with the traditional three-dimensional stress testing method of temperature cycling-vibration-humidity: Traditional method: 1000-hour test cycle, failure mode only detected at solder joint fatigue, life prediction accuracy 68%; The method of this invention: The test cycle is 180 hours, and the failure mode detected is solder joint fatigue + interface delamination (consistent with actual working conditions), with a life prediction accuracy of 92%; The comparison results show that the present invention is significantly better than the traditional method in terms of test cycle, failure mode matching degree, and prediction accuracy.

[0023] Judgment criteria Failure criteria: If the change in the electrical performance parameters of the chip package (such as on-resistance) exceeds 30%, or if the area of ​​solder joint cracking detected by X-ray is ≥50%, or if the interface delamination length is ≥20% of the package side length, it is judged as a failure. Prediction accuracy calculation standard: Prediction accuracy = (1 - |predicted life - actual life| / actual life) × 100%, where the actual life is determined by long-term reliability testing (more than 10,000 hours).

[0024] The beneficial effects of this invention are: by reproducing complex working conditions through a five-dimensional comprehensive stress environment, and by combining finite element simulation and PoF algorithm to achieve real-time correction of acceleration factors, the test cycle is significantly shortened and the lifetime prediction accuracy is improved. This provides an efficient and accurate technical solution for chip packaging reliability assessment and has significant industrial application value.

[0025] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for accelerated reliability testing and lifetime prediction of chip packages using multi-physics coupling, characterized in that, Includes the following steps: A five-dimensional comprehensive stress accelerated testing environment is constructed, wherein the five-dimensional comprehensive stress includes temperature cycling stress, vibration stress, humidity stress, power cycle thermal shock stress, and electromagnetic radiation field stress. Based on the aforementioned five-dimensional comprehensive stress, a five-dimensional accelerated testing model is established; Finite element simulation and PoF (Physics of Failure) algorithm are used to correct the acceleration factor in the five-dimensional accelerated test model in real time. Based on the modified acceleration factor and the five-dimensional accelerated testing model, a digital profile of chip package-level lifespan is established to achieve accelerated reliability testing and lifespan prediction for chip packages.

2. The method for accelerated reliability testing and lifetime prediction of chip packaging using multi-physics coupling as described in claim 1, characterized in that, In step 1, the temperature range of the temperature cycling stress is -55℃ to 150℃, and the cycle period is 30 minutes to 120 minutes; the frequency range of the vibration stress is 10 Hz to 2000 Hz, and the acceleration is 5g to 30g; the relative humidity range of the humidity stress is 30% to 95%.

3. The method for accelerated reliability testing and lifetime prediction of chip packaging using multi-physics coupling as described in claim 1, characterized in that, In step 1, the power cycle thermal shock stress is achieved through the chip's built-in heating element and heat dissipation module working together. The thermal shock temperature change rate is 5 degrees Celsius per second to 20 degrees Celsius per second, and the temperature fluctuation range of a single thermal shock is 25 degrees Celsius to 125 degrees Celsius.

4. The method for accelerated reliability testing and lifetime prediction of chip packaging using multi-physics coupling as described in claim 1, characterized in that, In step 1, the frequency range of the electromagnetic radiation field stress is 1 GHz to 10 GHz, and the radiation intensity is 10 V / m to 100 V / m.

5. The method for accelerated reliability testing and lifetime prediction of chip packaging using multi-physics coupling as described in claim 1, characterized in that, In step 3, the simulation objects of the finite element simulation include the stress distribution, heat conduction path and electromagnetic coupling effect of the chip packaging structure, and the simulation accuracy error is no greater than 5%.

6. The method for accelerated reliability testing and lifetime prediction of chip packaging using multi-physics coupling as described in claim 1, characterized in that, In step 3, the failure physics PoF algorithm is based on the key failure mechanisms of chip packaging, which include solder joint fatigue failure, bonding wire detachment, packaging material aging, and interface delamination.

7. The method for accelerated reliability testing and lifetime prediction of chip packaging using multi-physics coupling as described in claim 1, characterized in that, In step 4, the package-level lifetime digital profile includes the failure mode type, failure time distribution, remaining lifetime estimate, and reliability confidence interval of the chip package.

8. The method for accelerated reliability testing and lifetime prediction of chip packaging using multi-physics coupling as described in claim 1, characterized in that, In step 2, the five-dimensional accelerated testing model is constructed by weighted fusion of the accelerated models of each individual stress, and the weight coefficient of each stress is determined based on the stress influence weight under the actual working conditions of the chip.

9. The method for accelerated reliability testing and lifetime prediction of chip packaging using multi-physics coupling as described in claim 1, characterized in that, The accelerated test shall not exceed 200 hours and the lifetime prediction accuracy shall not be less than 90%.

10. The multi-physics coupled chip packaging reliability accelerated testing and lifetime prediction method as described in any one of claims 1 to 9, characterized in that, Suitable for ball grid array (BGA), chip-scale package (CSP), system-in-package (SiP), and flip chip type chip packaging.

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