Gallium nitride power device packaging parasitic parameter degradation monitoring method
By establishing a high-frequency RLC oscillation model and analyzing the rate of change of switching transient current, the degradation of gallium nitride power device packaging is identified, solving the problem of inaccurate monitoring in existing technologies, achieving early identification and efficient monitoring, and improving system reliability and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA ELECTRONICS RELIABILITY AND ENVIRONMENTAL TESTING INSTITUTE ((THE FIFTH INSTITUTE OF ELECTRONICS MINISTRY OF INDUSTRY AND INFORMATION TECHNOLOGY) (CHINA SAIBAO LABORATORY)
- Filing Date
- 2026-04-09
- Publication Date
- 2026-05-12
AI Technical Summary
Existing technologies struggle to accurately monitor the packaging degradation of gallium nitride (GaN) power devices under high-frequency switching conditions, especially changes in packaging parasitic parameters, leading to "failures without warning." Furthermore, existing methods increase computational complexity or hardware costs, impacting main circuit performance.
By establishing a high-frequency RLC oscillation model, collecting the rate of change of switching transient current, analyzing the relationship between package parasitic parameters and the rate of change of switching transient current, and using the frequency coefficient δ and oscillation frequency to identify package degradation, the system can monitor in real time whether early signs of degradation appear in the package.
This technology enables early identification of gallium nitride power device packaging degradation, improving monitoring accuracy and system reliability, avoiding impact on main circuit performance, and ensuring system stability and safety.
Smart Images
Figure CN122017515A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of gallium nitride power device degradation monitoring, and particularly to a method for monitoring the degradation of parasitic parameters in gallium nitride power device packaging. Background Technology
[0002] With the development of power electronics technology towards high frequency and high power density, gallium nitride (GaN) power devices have been widely used in energy systems, data center power supplies and other fields due to their advantages such as wide bandgap and high electron mobility.
[0003] Gallium nitride (GaN) power devices are affected by high current change rate (di / dt) and voltage change rate (dv / dt) during high-frequency switching. This not only leads to the degradation of the electrical parameters of the GaN power devices themselves (such as threshold voltage Vth and on-resistance R_on), but also accelerates the failure of package contacts, such as aging of solder lines and chemical reactions at the metal interconnect interface, resulting in changes in the inductance and parasitic resistance of the package.
[0004] Currently, degradation sensing and technology for gallium nitride (GaN) power devices mainly rely on single electrical parameters (such as Vth and R_on). However, during high-frequency switching, the energy exchange process between package parameters (parasitic resistance, parasitic inductance, and parasitic capacitance) and the switching transients has a significant impact on the performance of GaN power devices. Monitoring current changes alone often cannot fully reflect the package degradation state under high-frequency switching conditions and is prone to "failures without warning."
[0005] Chinese patent application number 202411335513.8, published on January 10, 2025, discloses an aging monitoring circuit and method for SiC power MOSFET devices. The circuit collects current and voltage data during the device's turn-off process and, combined with the relationship between the Kelvin source inductance and the power source inductance, monitors the bonding wire failure process of the SiC power MOSFET in real time.
[0006] However, the integration and division calculations mentioned in the patent may increase computational complexity, especially in real-time monitoring scenarios. These complex calculations could lead to monitoring delays and an inability to immediately reflect changes in device status. Furthermore, the patent uses invasive measurement, which not only increases hardware costs and design complexity but also introduces additional parasitic parameters that could affect the high-frequency performance of the main circuit. In addition, while existing current probe measurements are non-contact, they often only focus on current amplitude, lacking in-depth modeling and analysis of the quantitative relationship between switching transient oscillation characteristics and package parasitic parameters. This makes it difficult to accurately decouple and monitor package degradation mechanisms (such as increased parasitic resistance). Summary of the Invention
[0007] In view of this, the purpose of this invention is to provide a method for monitoring the degradation of parasitic parameters in gallium nitride (GaN) power device packages. By using package parasitic parameters to reflect the change rate of transient switching current, the method monitors whether the package of the GaN power device has degraded. This method can effectively identify early signs of package degradation and can capture early, minute signs of package degradation. It also has high accuracy in monitoring package degradation.
[0008] To solve the above-mentioned technical problems, the technical solution used in this invention is as follows:
[0009] The present invention discloses a method for monitoring the degradation of parasitic parameters in gallium nitride power device packages, comprising the following steps:
[0010] S1. Establish a high-frequency RLC oscillation model for gallium nitride power devices under high-frequency switching conditions, including package parasitic parameters.
[0011] S2. Acquire the transient current change rate of the switch and extract the measurement waveform of the transient current change rate of the switch.
[0012] S3. Compare the measured waveform of the switching transient current change rate with the reference waveform of the switching transient current change rate to determine whether the oscillation amplitude of the switching transient current change rate decreases; if so, proceed to S4.
[0013] S4. Determine the correlation between the package parasitic parameters and the oscillation amplitude of the switching transient current change rate.
[0014] S5. Predict whether the packaging of gallium nitride power devices is degraded.
[0015] Preferably, the package parasitic parameters include the equivalent parasitic resistance. Equivalent parasitic inductance Equivalent parasitic capacitance .
[0016] Preferably, S4 includes the following steps:
[0017] S4.1, through Determine the frequency coefficient δ;
[0018] S4.2, through Determine the oscillation frequency ;
[0019] S4.3, through Determine the frequency coefficient δ and the waveform of the switching transient current change rate. The oscillation amplitude is negatively correlated with the oscillation frequency. Waveform of transient current change during switching The oscillation amplitudes are positively correlated.
[0020] Preferably, S5 specifically involves increasing the frequency coefficient δ as the amplitude of the transient current change rate oscillation decreases, and decreasing the equivalent parasitic resistance. Increased size suggests that the packaging of gallium nitride power devices will degrade.
[0021] Preferably, S5 further includes, based on the equivalent parasitic resistance The degree of increase in the value of the material can be used to predict the degree of packaging degradation of gallium nitride power devices.
[0022] Preferably, in S3, the measured waveform of the switching transient current change rate includes a measured peak value, and the reference waveform of the switching transient current change rate includes a reference peak value; the measured peak value is compared with the reference peak value to determine whether the oscillation amplitude of the switching transient current change rate decreases.
[0023] Preferably, the measured peak value is the maximum absolute value of the first two peaks of the switching transient current change rate measurement waveform; the reference peak value is the maximum absolute value of the first two peaks of the switching transient current change rate reference waveform.
[0024] Preferably, S1 further includes: setting a preset stress application time; setting a preset gate voltage of the gallium nitride power device; continuously applying dynamic gate bias stress to the gallium nitride power device during the stress application time; and obtaining package parasitic parameters.
[0025] Preferably, a preset number of cycles is used, and dynamic gate bias stress is repeatedly applied to the gallium nitride power device during each stress application time, based on the preset number of cycles.
[0026] Record the switching transient current change rate and package parasitic parameters of gallium nitride power devices under different cycle numbers.
[0027] The changes in package parasitic parameters and the rate of change of switching transient current of gallium nitride power devices were verified as stress duration increased.
[0028] Compared with existing technologies, the main advantages of the gallium nitride power device package parasitic parameter degradation monitoring method described in this invention are as follows:
[0029] Since the rate of change of switching transient current is highly sensitive to changes in the equivalent parasitic resistance and equivalent parasitic inductance of the package parasitic parameters, the changes in the switching transient current rate of change are reflected by the package parasitic parameters. By using the package parasitic parameters to monitor whether the package of gallium nitride power devices has degraded, early signs of package degradation can be effectively identified, and even small signs of early package degradation can be captured. This method has high accuracy in monitoring package degradation.
[0030] Simultaneously, the oscillation characteristics during the switching transient process are analyzed without requiring a series resistor in the main power circuit or cutting off the circuit, thus not affecting the normal operation and efficiency of the system. By analyzing the changes in the oscillation amplitude of the switching transient current change rate, changes in package parasitic parameters can be quickly determined, thereby rapidly identifying whether the package of gallium nitride power devices has degraded.
[0031] The system extracts the changing characteristics of parasitic packaging parameters in real time during the operation of gallium nitride power devices; while ensuring system stability, it provides early warning of potential fault risks, thereby improving system reliability and operational safety. Attached Figure Description
[0032] The above and other objects, features, and advantages of the invention will become clearer through a more detailed description of the preferred embodiments illustrated in the accompanying drawings. The same reference numerals denote the same parts throughout the drawings, and the drawings are not intentionally drawn to scale with actual dimensions; the focus is on illustrating the gist of the invention.
[0033] Figure 1 This is a circuit diagram of the BOOST circuit in this invention.
[0034] Figure 2 This is the high-frequency RLC oscillation circuit model in this invention.
[0035] Figure 3 This is a schematic diagram of the impedance network in this invention.
[0036] Figure 4 The waveforms of the switching transient current, the rate of change of the switching transient current, and the pulse width modulation (PWM) drive voltage in this invention are shown.
[0037] Figure 5 This is a comparison chart of the oscillation amplitude of the transient current change rate in the switch in this invention.
[0038] Figure 6 A schematic diagram of the Z-parameter test curves for a gallium nitride power device without applied dynamic gate bias stress.
[0039] Figure 7 A schematic diagram of the Z-parameter test curves for applying dynamic gate bias stress to a gallium nitride power device.
[0040] Figure 8 This is a schematic diagram illustrating the degradation trend of encapsulated parasitic parameters with stress time in one embodiment of the present invention.
[0041] Figure 9 This is an experimental diagram of stress-test cycle testing of gallium nitride power devices according to the present invention.
[0042] Figure 10This is a schematic diagram illustrating the degradation trend of encapsulated parasitic parameters with stress time in another embodiment of the present invention.
[0043] Figure 11 This is a comparison chart showing the rate of change of current when dynamic gate bias stress is applied to gallium nitride power devices according to the present invention. Detailed Implementation
[0044] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention. In this embodiment, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.
[0045] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to and integrated with the other element, or there may be an intervening element present. The terms "mounted," "one end," "the other end," and similar expressions used in this invention are for illustrative purposes only.
[0046] like Figure 1-5 As shown; a method for monitoring the degradation of parasitic parameters in gallium nitride power device packages, comprising the following steps:
[0047] S1. Establish a high-frequency RLC oscillation model for gallium nitride power devices under high-frequency switching conditions, including package parasitic parameters.
[0048] S2. Acquire the transient current change rate of the switch and extract the measurement waveform of the transient current change rate of the switch.
[0049] S3. Compare the measured waveform of the switching transient current change rate with the reference waveform of the switching transient current change rate to determine whether the oscillation amplitude of the switching transient current change rate decreases; if so, proceed to S4.
[0050] S4. Determine the correlation between the package parasitic parameters and the oscillation amplitude of the switching transient current change rate.
[0051] S5. Predict whether the packaging of gallium nitride power devices is degraded.
[0052] The package parasitic parameters include parasitic inductance, parasitic resistance, and parasitic capacitance; the parasitic inductance includes the gate parasitic inductance. Drain parasitic inductance Source parasitic inductance Parasitic resistance includes gate parasitic resistance. Drain parasitic resistance Source parasitic resistance Parasitic capacitance includes gate-source capacitance. Gate-drain capacitance and drain-source capacitance .
[0053] The above S1 specifically includes the following steps:
[0054] S1.1 The main circuit of the BOOST circuit under high-frequency switching transient is equivalent to a high-frequency RLC oscillation circuit model.
[0055] S1.2 Introducing parasitic packaging parameters for gallium nitride power devices.
[0056] S1.3 Under high-frequency switching conditions, the parasitic inductance, parasitic resistance, and parasitic capacitance of the package parasitic parameters are equivalently represented as an impedance network (equivalent oscillating loop impedance model). The impedance network (equivalent oscillating loop impedance model) includes the equivalent parasitic resistance. Equivalent parasitic inductance and equivalent parasitic capacitance The impedance network (equivalent oscillating loop impedance model) is a high-frequency circuit model.
[0057] Reference Figure 1 As shown, under high-frequency switching conditions, the gate-source capacitance in the gate branch... and gate-drain capacitance The equivalent capacitive reactance approaches zero, and the high-frequency signal generated by the switching transient is absorbed by the gate-source capacitance. and gate-drain capacitance This forms a bypass. Gate parasitic inductance. and gate parasitic inductance Parasitic gate inductance connected in parallel Source parasitic inductance This is equivalent to entering an open loop.
[0058] ; This is the total equivalent impedance.
[0059] The equivalent parameters of the turn-on loop high-frequency RLC oscillator circuit model are:
[0060] Equivalent parasitic resistance , The equivalent series resistance of the inductance. This is the resistance of the loop trace.
[0061] Equivalent parasitic inductance , This is the stray inductance of the circuit.
[0062] Equivalent parasitic capacitance , This is the distributed capacitance of the inductor.
[0063] The above S2 specifically includes the following steps:
[0064] S2.1 Acquire transient current signals of gallium nitride power devices under high-frequency switching conditions.
[0065] S2.2. Differentiate the acquired transient current signal to obtain the rate of change of the switching transient current. The waveform. In this embodiment, transient current signals are acquired using a contact measuring device, preferably a frequency lightning current probe.
[0066] In S3 above, the waveform for measuring the rate of change of the switching transient current includes the measured peak value. The reference waveform of the switching transient current change rate includes the reference peak value; the measured peak value is compared with the reference peak value to determine whether the oscillation amplitude of the switching transient current change rate decreases.
[0067] The measured peak value is the maximum absolute value of the first two peaks of the measured waveform of the switching transient current change rate; the reference peak value is the maximum absolute value of the first two peaks of the reference waveform of the switching transient current change rate. The first two peaks of the switching transient current change rate are highly sensitive to the package degradation of gallium nitride power devices, and have no parasitic oscillation interference, excellent robustness and signal-to-noise ratio; using the maximum absolute value of the first two peaks directly reflects the changes in the switching transient current change rate and package parasitic parameters, with high accuracy.
[0068] When the equivalent parasitic resistance of the turn-on loop is... When the angle of view is large or much smaller than the resonant period, the oscillation energy decays rapidly, and the maximum peak value appears at the first peak.
[0069] When the equivalent parasitic resistance of the turn-on loop is... When the switching time and the resonant period meet the approximate half-cycle matching condition, the residual oscillation and the additional response in the turn-on phase are mutually reinforcing, which significantly increases the amplitude of the second peak. In the maximum turn-on phase, the residual oscillation and the additional response are mutually reinforcing, which significantly increases the amplitude of the second peak. At this time, the maximum peak value appears at the second peak.
[0070] Reference Figure 5As shown, as the threshold voltage (Vth) increases, the peak switching current (i'_sw (pk)) decreases; the maximum peak value appears at the first peak, and the maximum absolute value of the first two peaks of the rate of change of the switching transient current is the peak value of the first peak. ( () is the reference waveform for the rate of change of the transient current during switching; ( The waveform represents the rate of change of switching transient current when the package of a gallium nitride power device degrades. ( The waveform represents the rate of change of switching transient current as the package of a gallium nitride power device continues to degrade.
[0071] S4 includes the following steps:
[0072] S4.1, through Determine the frequency coefficient δ.
[0073] S4.2, through Determine the oscillation frequency .
[0074] S4.3, through Determine the frequency coefficient δ and the waveform of the switching transient current change rate. The oscillation amplitude is negatively correlated with the oscillation frequency. Waveform of transient current change during switching The oscillation amplitudes are positively correlated.
[0075] Specifically, S5 refers to the fact that when the amplitude of the oscillation of the rate of change of the switching transient current decreases, the frequency coefficient δ increases, and the equivalent parasitic resistance... Increase, total equivalent impedance Increased resistance indicates predicted degradation in the packaging of gallium nitride (GaN) power devices. As the packaging of GaN power devices degrades (e.g., bond wire breakage, increased contact resistance), the equivalent parasitic resistance increases. It will increase significantly; while when the parasitic resistance As the value increases, the frequency coefficient δ increases, leading to increased dissipation in gallium nitride power devices and a decrease in the oscillation amplitude of the switching transient current rate of change. Furthermore, based on the equivalent parasitic resistance... The degree of increase in the value can predict the degree of packaging degradation of gallium nitride power devices.
[0076] The above methods are highly sensitive to changes in the switching transient current rate of change, which are highly sensitive to changes in the equivalent parasitic resistance and equivalent parasitic inductance of the package parasitic parameters. By reflecting the changes in the switching transient current rate of change through package parasitic parameters, and using package parasitic parameters to monitor whether the package of gallium nitride power devices has degraded, these methods can effectively identify early signs of package degradation and capture even small early signs of package degradation. This approach offers high accuracy in monitoring package degradation.
[0077] Simultaneously, the oscillation characteristics during the switching transient process are analyzed without requiring a series resistor in the main power circuit or cutting off the circuit, thus not affecting the normal operation and efficiency of the system. By analyzing the changes in the oscillation amplitude of the switching transient current change rate, changes in package parasitic parameters can be quickly determined, thereby rapidly identifying whether the package of gallium nitride power devices has degraded.
[0078] The system extracts the changing characteristics of parasitic packaging parameters in real time during the operation of gallium nitride power devices; while ensuring system stability, it provides early warning of potential fault risks, thereby improving system reliability and operational safety.
[0079] In a preferred embodiment, the method further includes verifying the monitoring method described above; the verification method includes the steps described above:
[0080] A1. Preset number of cycles, preset stress duration, preset gate voltage of gallium nitride power devices.
[0081] A2. During the stress application time, dynamic gate bias stress is continuously applied to the gallium nitride power device.
[0082] A3. Based on the number of cycles, repeat A2, record the S-parameters of the gallium nitride power device during each stress period, and collect the switching transient current change rate of the gallium nitride power device during each stress period; until the number of cycles is met, then proceed to A4.
[0083] A4. Convert the S-parameters to encapsulated parasitic parameters.
[0084] A5. By comparing the rate of change of current and the parasitic parameters of the package, we can verify the changes in the parasitic parameters of the package and the rate of change of the switching transient current of the gallium nitride power device as the stress duration of the applied dynamic gate bias stress increases.
[0085] In this embodiment, the stress application time is 10-30 minutes, preferably 20 minutes; the gate voltage of the gallium nitride power device is 10V / -5V, preferably 5V / -1V. The cycle is repeated three times. The initial stress application time is 20 minutes, and the maximum stress application time is 80 minutes. Specifically, the first cycle stress application time totals 40 minutes, the second cycle stress application time totals 60 minutes, and the third cycle stress application time totals 80 minutes.
[0086] Reference Figure 9 As shown, each cycle consists of two phases: the measurement phase and the stress phase.
[0087] During the measurement phase, a parameter analyzer is used to measure the IV characteristics of the device, and a vector network analyzer (VNA) is used to measure the S-parameters of the device to extract package parasitic parameters.
[0088] During the stress stage, a high-frequency dynamic gate bias stress is applied to the gallium nitride power device for 20 minutes. The gate voltage is set to a square wave signal of 5V / -1V, the switching period is 1μs (corresponding to a frequency of 500kHz), and the drain-source voltage VDS switches periodically between high and low levels according to the gate switching state.
[0089] After each 20-minute stress application cycle, the stress is paused, and the next test phase begins. The current IV characteristics and S-parameters of the device are recorded, and then the next stress cycle begins. This cycle is repeated until the cumulative stress time reaches 80 minutes. Through this continuous stress-test cycle, the evolution of package parasitic parameters with high-frequency switching stress can be systematically tracked, and the transient current change rate waveform of the switch at each stage can be acquired, enabling the gradual recording and analysis of the package degradation process.
[0090] Reference Figure 10 As shown, the drain parasitic resistance increases with the cumulative stress duration of the applied dynamic gate bias stress. The equivalent parasitic resistance continues to increase. It continues to increase. Due to the equivalent parasitic resistance , The equivalent series resistance of the inductance. For loop trace resistance. Drain parasitic resistance. With equivalent parasitic resistance The relationship is positively correlated when the drain parasitic resistance Increase, equivalent parasitic resistance Increase.
[0091] Verification shows that as the stress duration of the applied dynamic gate bias stress increases, the equivalent parasitic resistance of the package parasitic parameters increases, and the oscillation amplitude of the switching transient current rate of change of the gallium nitride power device decreases; that is, as the package of the gallium nitride power device degrades, the equivalent parasitic resistance of the package parasitic parameters decreases. As the current increases, the oscillation amplitude of the switching transient current change rate of gallium nitride power devices decreases.
[0092] Reference Figure 11 As shown, the waveform corresponding to Fersh is the rate of change of the reference switching transient current without applied dynamic gate bias stress; the waveform corresponding to 20min is the rate of change of the switching transient current with applied dynamic gate bias stress for 20min; the waveform corresponding to 40min is the rate of change of the switching transient current with applied dynamic gate bias stress for 40min; the waveform corresponding to 60min is the rate of change of the switching transient current with applied dynamic gate bias stress for 60min; and the waveform corresponding to 80min is the rate of change of the switching transient current with applied dynamic gate bias stress for 80min. As the duration of applied dynamic gate bias stress increases, the oscillation amplitude of the switching transient current rate of change gradually decreases.
[0093] The above verification method applies dynamic gate bias stress to gallium nitride power devices in multiple cycles, with the stress application time as one period, to conduct aging experiments. This verifies the relationship between equivalent parasitic resistance, the oscillation amplitude of the switching transient current rate of change of gallium nitride power devices, and the degradation of gallium nitride power device packages. Verification shows that changes in equivalent parasitic resistance and the oscillation amplitude of the switching transient current rate of change can monitor whether gallium nitride power devices are degrading.
[0094] like Figure 6-8 As shown, in another embodiment, the degradation trend of package parasitic parameters with stress time is confirmed by the offset of the frequency curve.
[0095] Reference Figure 6 As shown, the curves are the Z-parameter test curves of the gallium nitride power device without applied dynamic gate bias stress (Fresh); the Z-parameters are the two-port network Z-parameters measured by a vector network analyzer, and the Z-parameters vary with frequency. 11 |、|Z 21 |、|Z 12 |、|Z 22 | represent different impedance parameters of the two-port network, and |Z 11 |、|Z 21 |、|Z 12 |、|Z 22 | The corresponding horizontal axis represents frequency (0-200MHz); and |Z 11 |、|Z 21 |、|Z 12 |、|Z 22The corresponding vertical axis represents the magnitude of the Z-parameter.
[0096] |Z 11 |、|Z 21 |、|Z 12 |、|Z 22 The frequency response characteristics of the relevant curves show that in the low-frequency range, capacitance dominates. As the frequency increases, the capacitive reactance of the parasitic capacitance decreases, and the impedance decreases, with the impedance decreasing as the frequency increases. When the frequency reaches the self-resonant frequency (valence) of the capacitor, the energy exchange between the inductance and capacitance reaches equilibrium, and the impedance equals the equivalent series resistance. In the high-frequency range, inductance dominates. As the frequency increases, the inductive reactance of the parasitic inductance increases, and the impedance increases, with the impedance increasing as the frequency increases. The changes in impedance are reflected through inductance and capacitance.
[0097] The Z-parameter test curve of the gallium nitride power device without dynamic gate bias stress (Fresh) is used to provide a reference for comparing Z-parameters at different aging time points in stress testing. The degradation trend of parasitic inductance, parasitic resistance, and parasitic capacitance of the package parasitic parameters with stress time is confirmed by the offset of the frequency curve.
[0098] Reference Figure 7-8 As shown, dynamic gate bias stress was applied to gallium nitride power devices for durations of 20 min, 40 min, 60 min, 80 min, and 100 min; the applied stress was the same at different stress application times. This was to confirm the degradation trend of package parasitic parameters with stress application time. With increasing stress application time, the drain parasitic resistance... The equivalent parasitic resistance continues to increase. As the number of gallium nitride (GaN) increases, power devices begin to degrade.
[0099] In this specification, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0100] In the description of this specification, the references to terms such as "preferred embodiment," "another embodiment," "other embodiment," or "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0101] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.
Claims
1. A method for monitoring the degradation of parasitic parameters in gallium nitride power device packages, characterized in that: Includes the following steps: S1. Establish a high-frequency RLC oscillation model for gallium nitride power devices under high-frequency switching conditions, including package parasitic parameters; S2. Acquire the transient current change rate of the switch and extract the measurement waveform of the transient current change rate of the switch; S3. Compare the measured waveform of the switching transient current change rate with the reference waveform of the switching transient current change rate to determine whether the oscillation amplitude of the switching transient current change rate decreases; if so, proceed to S4. S4. Determine the correlation between the package parasitic parameters and the oscillation amplitude of the switching transient current change rate; S5. Predict whether the packaging of gallium nitride power devices is degraded.
2. The method for monitoring the degradation of parasitic parameters in gallium nitride power device packaging according to claim 1, characterized in that: Package parasitic parameters include equivalent parasitic resistance. Equivalent parasitic inductance Equivalent parasitic capacitance .
3. The method for monitoring the degradation of parasitic parameters in gallium nitride power device packaging according to claim 2, characterized in that: S4 includes the following steps: S4.1, through Determine the frequency coefficient δ; S4.2, through Determine the oscillation frequency ; S4.3, through Determine the frequency coefficient δ and the waveform of the switching transient current change rate. The oscillation amplitude is negatively correlated with the oscillation frequency. Waveform of transient current change during switching The oscillation amplitudes are positively correlated.
4. The method for monitoring the degradation of parasitic parameters in gallium nitride power device packaging according to claim 3, characterized in that: Specifically, S5 refers to the fact that when the amplitude of the oscillation of the rate of change of the switching transient current decreases, the frequency coefficient δ increases, and the equivalent parasitic resistance... Increased size suggests that the packaging of gallium nitride power devices will degrade.
5. The method for monitoring the degradation of parasitic parameters in gallium nitride power device packaging according to claim 4, characterized in that: S5 also includes, based on equivalent parasitic resistance The degree of increase in the value of the material can be used to predict the degree of packaging degradation of gallium nitride power devices.
6. The method for monitoring the degradation of parasitic parameters in gallium nitride power device packaging according to claim 3, characterized in that: In S3, the measured waveform of the switching transient current change rate includes the measured peak value, and the reference waveform of the switching transient current change rate includes the reference peak value; the measured peak value is compared with the reference peak value to determine whether the oscillation amplitude of the switching transient current change rate decreases.
7. The method for monitoring the degradation of parasitic parameters in gallium nitride power device packaging according to claim 6, characterized in that: The measured peak value is the maximum absolute value of the first two peaks of the waveform measuring the rate of change of the switching transient current; the reference peak value is the maximum absolute value of the first two peaks of the reference waveform measuring the rate of change of the switching transient current.
8. The method for monitoring the degradation of parasitic parameters in gallium nitride power device packaging according to claim 3, characterized in that: S5 also includes preset stress application time; The gate voltage of the gallium nitride power device is preset; during the stress application time, dynamic gate bias stress is continuously applied to the gallium nitride power device. Obtain the encapsulation parasitic parameters.
9. The method for monitoring the degradation of parasitic parameters in gallium nitride power device packaging according to claim 8, characterized in that: The number of cycles is preset, and dynamic gate bias stress is repeatedly applied to the gallium nitride power device during each stress application time, based on the number of cycles. Record the switching transient current change rate and package parasitic parameters of gallium nitride power devices under different cycle numbers; The changes in package parasitic parameters and the rate of change of switching transient current of gallium nitride power devices were verified as stress duration increased.