FIELD: control and measuring equipment.
SUBSTANCE: invention relates to control and measurement equipment, in particular, to measurement of thermal parameters of power semiconductor devices (PSD) in housing design. Semiconductor crystal is heated by passing through it direct current of the specified amplitude I. During heating the value I and voltage drop U on the tested device are measured. Value of heating power P is calculated by expression P=IU. After time t equal to three times the thermal constant of the device design t=3τT, the heating current source is switched off. Simultaneously, a measuring current source is connected and the value of the heat-sensitive parameter is measured at the moment of heating current source disconnection, which is represented by direct voltage drop on the Unp1 crystal. After time t=3τT at the end of the process of natural redistribution of heat accumulated by the semiconductor crystal along the structure of the device design, including the solid body of the housing of the instrument housing, the value of the heat-sensitive parameter Unp2 is repeatedly measured. Obtained values are used to calculate the difference Unp1-Unp2 and determine the difference between the transition and the case temperature of the test device KT⋅(Unp1-Unp2)=TJ-TC, where KT is the value of the temperature coefficient of the forward voltage. Value of heat resistance transition-case Rthjc is calculated as ratio of obtained values TJ-TC and power P.
EFFECT: providing nondestructive control of thermal resistance of a transition-case PSD, shorter measurement time and ultimately increasing yield of articles in a process cycle of their serial production.
1 cl, 8 dwg
