Research On The Damage Mechanism And Reinforcement Technology Of Electrostatic And RF On SCB Explosive Devices

It is important to explore the electromagnetic interference (EMI) mechanism for the electromagnetic compatibility (EMC) design of semiconductor bridge (SCB) explosive devices. The main contents in this paper include electro-thermal conversion model of electrostatic discharge (ESD) and heat transfer model of radio frequency (RP) for SCB, the electrostatic and RF sensitivity of SCB, SCB plasma diagnosis, the response of bridge film and explosive structure to electrostatic and RF, SCB ignition experiments, electromagnetic reinforcement methods for SCB. The research contents and conclusions are as follows:(1) The electro-thermal conversion physical model and heat transfer mathematical model of electromagnetic to SCB were established. The transformation process of electromagnetic energy to Joule heating energy was analyzed, besides, the energy conversion efficiency and thermal dissipation, thermal equilibrium were discussed. The simulation result shows that EMI energy generates current density distribution on the surface of SCB film. The effect of Joule heating becomes greater as the current density increases. The electro-thermal conversion efficiency of ESD that belongs to the strongly transient heat conduction is higher than RF who has more thermal dissipation and loss.(2) The Ansys software was used to simulate the electro-thermal coupling of EMI to SCB and the results show that the two V-type angles have the highest temperature. The temperature value increases from the geometric center of bridge film to the angles and decreases from the central region to the edges. ESD can produce the temperature higher than the boiling point of polysilicon bridge to form plasma discharge, while RF ignites the explosive mainly by heat transfer. The electrostatic and RF damage mechanisms of SCB explosive devices provide the guidance and ideas for the electromagnetic protection.(3) The electrostatic and RF sensitivity of SCB were tested by the related experiments and the action mechanisms of electrostatic and RF were discussed. The microwave resonator probe and high-speed photography were used to measure the resultant plasma density variations during ESD process. The influence of electrostatic energy to ESD process and the physical form transformation of bridge film were obtained. The plasma electron density, luminous intensity and size variations as a function of time confirmed the plasma damage mechanism of ESD to SCB. The ignition condition of ESD thermal conductivity was discussed, as well as the response of discharge process to different electrostatic voltage and energy. (4) The bridge appearances and explosive structures before and after RF were analyzed, as well as the influences of RF to the ignition properties, the electrical and thermodynamic parameters, the chemical structure of SCB film and explosive. The conclusion is that RF power, field strength and frequency affect the induced current on SCB chip, but the RF energy has no significant effect on the SCB film.(5) According to the ESD action mechanism and microelectronics packaging technology, the surface mount devices (SMD) varistor was used to protect V-type SCB from ESD and it can effectively reduce the electrostatic sensitivity of explosive device. HAWK3optical microscope, capacitor discharge unit (CDU) system and so on were adopted to test the reinforcement effect. It is shown that the typical SCBs are no-fire under the GJB standard, contrarily, under the US military standard. The varistor can absorb transient voltage pulse and reduce the current through SCB. Ultimately, it improves the anti-static properties of explosive device.(6) According to the RF action mechanism and the diversion laws of microelectronic circuit, the discrete components were used to enhance the anti-RF performance of SCBs which had different bridge-shaped, and ignition energy. The protective principle of NTC thermistors for SCB is different from TVS diodes and ferrite beads. The influence of induced temperature on SCB chip is independent with the electrical parameters of thermistors under the RF. NTC thermistors improve the heat dissipation efficiency of the ceramic plug and reduce the temperature on SCB chip. Finally, the RF sensitivity of explosive device is decreased and the thermistors do not affect the normal ignition of SCB.