Switch Package Research Articles

A Robust, Composite Packaging Approach for a High Voltage 6.5kV IGBT and Series Diode

The main motivation of this work is to design, fabricate, test, and compare an alternative, robust packaging approach for a power semiconductor current switch. Packaging a high voltage power semiconductor current switch into a single power module, compared to using separate power modules, offers cost, performance, and reliability advantages. With the advent of Wide-Bandgap (WBG) semiconductors, such as Silicon-Carbide, singular power electronic devices, where a device is denoted as a single transistor or rectifier unit on a chip, can now operate beyond 10kV–15kV levels and switch at frequencies within the kHz range. The improved voltage blocking capability reduces the number of series connected devices within the circuit, but challenges power module designers to create packages capable of managing the electrical, mechanical, and thermal stresses produced during operation. The non-sinusoidal nature of this stress punctuated with extremely fast changes in voltage and current, with respect to time, leads to non-ideal electrical and thermal performance. An optimized power semiconductor series current switch is fabricated using an IGBT (6500V/25A die) and SiC JBS Diode (6000V/10A), packaged into a 3D printed housing, to create a composite series current switch package (CSCSP). The final chosen device configuration was simulated and verified in an ANSYS software package. Also, the thermal behavior of such a composite package was simulated and verified using COMSOL. The simulated results were then compared with empirically obtained data, in order to ensure that the thermal ratings of the power devices were not exceeded; directly affecting the maximum attainable frequency of operation for the CSCSP. Both power semiconductor series current switch designs are tested and characterized under hard switching conditions. Special attention is given to ensure the voltage stress across the devices is significantly reduced.

Analysis of RF MEMS switch packaging Process for yield improvement

Radio frequency microelectro-mechanical systems (RF MEMS) switches offer significant performance advantages in high-frequency RF applications. The switches are actuated by electrostatic force when voltage was applied to the electrodes. Such devices provide high isolation when open and low contact resistance when closed. However, during the packaging process, there are various possible failure modes that may affect the switch yield and performance. The RF MEMS switches were first placed in a package and went through lid seal at 320/spl deg/C. The assembled packages were then attached to a printed circuit board at 220/spl deg/C. During the process, some switches failed due to electrical shorting. Interestingly, more failures were observed at the lower temperature of 220/spl deg/C rather than 320/spl deg/C. The failure mode was associated with the shorting bar and the cantilever design. Finite element simulations and simplified analytical solutions were used to understand the mechanics driving the behaviors. Simulation results have shown excellent agreement with experimental observations and measurements. Various solutions in package configurations were explored to overcome the hurdles in MEMS packaging and achieve better yield and performance.

Simple, multiple arc, dielectric switch applied to a theta pinch

The construction and the operating details of a simple, field distortion, dielectric switch first used by Martin at A.W.R.E. and later extensively investigated by Dokopoulos at Jülich are presented. The switch, triggered by a small, fast Marx circuit, holds off approximately 110 kV and switches 70 kV at 500 kA with an inductance of 12 nH. The switch produces multiple arcs through the switch package without meticulous switch package preparation, with pitted and scarred switch electrodes, and with a relatively slow trigger system. The dielectric switch is used in a fast theta pinch system and is designed to facilitate ease of operation, switch package preparation, and repeatable performance.