Alicja Palczynska

Prognostic approaches for the wirebond failure prediction in power semiconductors: A case study using DPAK package

Reliability of the standard DPAK component under passive temperature cycling as well as combined passive and active temperature cycling is investigated. A special test vehicle is designed to mount six DPAK components with various orientations on a PCB. The stress state during the passive temperature cycling is monitored using three IForce piezoresistive stress sensors mounted on one side of the PCB. In addition, three temperature sensors are used for in-situ temperature measurement, which is critically required for active operation of the designed test vehicle during active power cycling and/or field condition tests. In this paper, only the results of the passive temperature cycling are presented. Based on the preliminary results, a relation between the damage evolution and the failure of the DPAK can be established, which offers a potential application of using the IForce sensor as a canary device for Prognostics and health management.

Investigation of Uncertainty Sources of Piezoresistive Silicon Based Stress Sensor

The aim of this paper is to get insight into measurement uncertainties for thermomechanical measurements performed using a piezoresistive silicon-based stress sensor in a standard microelectronic package. All used sensors have the same construction, were produced in the same technological processes at the same time, yet the measurement results show significant distribution. The possible causes for this phenomenon are discussed in this paper. Additionally, Finite Element Method (FEM) model is created and validated, what enables a study of sensitive parameters influencing the measurement uncertainties.

Condition Monitoring Algorithm for Piezoresistive Silicon-Based Stress Sensor Data Obtained from Electronic Control Units

Recent advancements in automotive technologies, most notably autonomous driving, demand electronic systemsmuch more complex than realized in the past. The automotiveindustry has been forced to adopt advanced consumerelectronics to satisfy the demand, and thus it becomes morechallenging to assess system reliability while adopting the newtechnologies. The system level reliability can be enforced byimplementing a process called condition monitoring. In thispaper, a piezoresistive silicon based stress sensor isimplemented to detect physical damages in outer moldedelectronic control units (ECU) subjected to reliability testingconditions. The test vehicle consists of six DPAK powerpackages and three stress sensors mounted on a PrintedCircuit Board (PCB). A unique algorithm is proposed andimplemented to handle the data obtained from thepiezoresistive stress sensing cells. The accuracy of measureddata is examined by Finite Element method (FEM), and thephysical changes are validated with Scanning AcousticMicroscope (SAM).

Hybrid Approach to Conduct Failure Prognostics of Automotive Electronic Control Unit

A model/sensor hybrid approach is implemented to conduct failure prognostics of an automotive electronic control unit (ECU). A 3-D finite element model simulating a complex ECU is built, and its predictability is calibrated and verified by an optical displacement measurement technique called moiré interferometry. The stress states of the ECUs during thermal cyclic loadings are documented by piezoresistive-based stress sensors embedded in the test vehicles. The verified model is then utilized to develop a quantitative relationship between the stress senor data and the stress of the most critical locations in the ECU. The modeling and verification steps that lead to the predictive finite element model are described. The stress history of the critical locations obtained by the hybrid approach is presented.

Simulation Driven Design of Novel Integrated Circuits -- Physics of Failure Simulation of the Electronic Control Modules for Harsh Environment Application

Reduction of development time of an advanced Electronic Control Unit (ECU) requires optimization of the product design at the early stage of development. A simulation-driven design has been used effectively to define the ideal position of components for optimum reliability even before the first prototype is manufactured. Such methods are based on a virtual design of experiments that allows to investigate different layouts or to optimize the ECU. In this paper a physics of failure simulation of the ECU is presented for automotive applications. A test vehicle with power packages on a PCB is designed and tested to enable the analysis of system behavior with three different relative orientations of DPAKs (Discrete Package). The failure modes are identified by FMMEA, and risk assessment is conducted using a systematic simulation approach. The approach involves a sequential numerical simulation of electrical, thermal and thermo-mechanical analysis. The final results are analyzed with a special emphasis on the design elements, where the failure is expected.

Towards prognostics and health monitoring: The potential of fault detection by piezoresistive silicon stress sensor

A piezoresistive silicon based stress sensor has been demonstrated successfully as an effective tool to monitor the stresses inside electronic packages during various production processes. More recently, the sensor has been evaluated as a sensor for Prognostics and Health Monitoring (PHM) systems. This paper presents a systematic approach that evaluates its performance from the perspective of failure mode detection. A detailed Finite Element method (FEM) model of existing test vehicles is created. The test vehicle consists of six DPAK power packages and three stress sensors. The results of simulation are verified by the signals obtained from the stress sensor as well as the supplementary warpage measurements. After inserting various failure modes into the model, statistical pattern recognition algorithms are implemented for fault detection and classification. The proposed technique can identify detectable failures during reliability testing by utilizing the database of stress sensor responses for healthy and unhealthy state. Thus, the results establish a baseline for the applicability of the piezoresistive stress sensor for an on-line monitoring PHM methodology.