Patent ID: 11953538
Assignee: WUHAN UNIVERSITY
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method for predicting an insulated gate bipolar transistor (IGBT) lifetime based on compound failure mode coupling, comprising:
S1: calculating a simultaneous failure probability model of a bonding wire and a solder layer from a failure probability distribution of the solder layer and a failure probability distribution of the bonding wire;
In S2, calculating and recording an expectancy of the simultaneous failure probability model as a lifetime under a coupling effect;
S3: calculating a difference percentage between a lifetime of the solder layer and a lifetime of the bonding wire from the failure probability distribution of the solder layer and the failure probability distribution of the bonding wire, establishing a coupling function relation by treating the difference percentage between the lifetime of the solder layer and the lifetime of the bonding wire as an input and treating a lifetime change rate before coupling and after coupling as an output;
S4: predicting the lifetime of the solder layer and the lifetime of the bonding wire; wherein the step 4 further comprises: S4.1: making the IGBT circuit perform a power cycle aging experiment under conditions of different junction temperature fluctuations ΔTj and average junction temperatures Tjm until the IGBT circuit fails;
S5: establishing an IGBT lifetime prediction model not taking the coupling effect into account; and
S6: establishing an IGBT lifetime prediction model taking the coupling effect into account, performing lifetime prediction through the IGBT lifetime prediction model taking the coupling effect into account;
when the lifetime of the solder layer is close to the lifetime of the bonding wire, the lifetime of the IGBT circuit be predicted due to the coupling effect of the two;
wherein a failure mode of the IGBT circuit be predicted, which is conducive to the subsequent management of reliability.