Electro-thermal Modeling Research On The Bridge Region Of H-shaped Semiconductor Bridge Without Charge Activated By Capacitances

Thoese parameters on voltage,current,resistance and plasma temperature dynamically changed when the Semiconductor Bridge Initiator was functioning.The dynamical parameters were critical to understand the functioning mechanism of Semiconductor Bridge Initiators,particularly the plasma temperature,which was a vital factor influencing the ignition effect of powders.By systematically modeling the electro-thermal process of Semiconductor Bridge,including heat conduction models of Semiconductor Bridge,voltage control equations and resistance-temperature models,a comparatively accurate model anticipating the temperature of bridge region was obtained.The main achievements are as follows:1)The threshold energy that makes Semiconductor Bridge(100μm×380μm×2μm) discharge plasma was modified as 1.77 mJ.The Semiconductor Bridge is not capable of plasma discharging,if the energy stored in capacitances is less than the threshold energy.2)A one-dimensional heat conduction model of the substrate-bridge-powder system was proposed.Accordingly,the temperature rising rate curve of Semiconductor Bridge resistance was obtained.3)A strong transient heat conduction model of the bridge-substrate semi-infinite body was proposed.When discharged the plasma from the Semiconductor Bridge activated by a capacitor(22μF,24 V),the evaluated temperature by this model was 2612 K,compared with experimental temperature of 2394 K.4)A heat convection model of lumped parameters on the bridge region of Semiconductor Bridges was proposed,and therefore the temperature rising rate curve of Semiconductor Bridge resistance was obtained.5)Voltage control equations were presented to characterize the relationship between resistance and current when the firing circuit was activated by capacitance.Both theoretical and empirical voltage control equations agreed with the experimental results.6)A model was proposed to characterize the relationship between Semiconductor Bridge's resistance and temperature.This model revealed that the electrical resistivity of Semiconductor Bridge was the function of specific energy before Semiconductor Bridge gasified.