| 摘要 |
A power transistor module comprises a circuit substrate, at least one pair of power transistor chips (Tr1, Tr2) mounted on said circuit substrate and each transistor chip having a first and a second main electrode and a control electrode, a flywheel diode (D1, D2) connected in antiparallel to said main electrodes of each power transistor chip, internal connection means for connecting one of said main electrodes of a first (Tr1) of said transistor chips to one of said main electrodes of the second transistor chip (Tr2) so as form the upper and lower arms of a bridge circuit, external connection terminals (C1, C2E1, E2, G1, G2) for connection to a main circuit, of which a first one (C1) is connected to the other one of said main electrodes of said first transistor chip (Tr1), a second one (C2E1) is connected to said internal connection means, and a third one (E2) is connected to the other one of said main electrodes of said second transistor chip (Tr2), and a first and a second auxiliary terminal (e1, e2) of which the first auxiliary terminal (e1) is connected to said internal connection means at a position same as the position at which the second external connection terminal (C2E1) is connected to it or nearer to said one main electrode of the first transistor chip (Tr1) than the latter, and the second auxiliary terminal (e2) is connected to the third external connection terminal (E2), wherein said internal connection means provides a predetermined wiring inductance (l1) between said one main electrode of the first power transistor chip (Tr1) on the one hand and the position at which said first auxiliary terminal (e1) is connected to it on the other hand. By this structure a surge generated at the time of the switching operation is suppressed, while at the same time, a balance is obtained in the switching characteristics between the upper and lower arms of the bridge when the internal wiring inductance l1 (l1=l2) is adjusted to have an appropriate value. <IMAGE> |
