1. A semiconductor substrate jig used for arranging a film on one surface of a semiconductor substrate, wherein said semiconductor substrate jig comprises: a frame; and an expandable member arranged within said frame, and increasing or decreasing volume while deforming a shape of said expandable member by being supplied with fluid therein; wherein said shape is deformed so that said film arranged between said semiconductor substrate and said expandable member is pressed against said semiconductor substrate as contacting portion of the expandable member to the film is enlarged outwardly from the center of said film as said volume increases.
2. A semiconductor substrate jig as claimed in claim 1, wherein a movable plate is provided inside said expandable member, and is movable to a position contacting said expandable member when said expandable member presses substantially an entire surface of said film against said semiconductor substrate, wherein a state in which said expandable member presses said substantially entire surface of said film to said semiconductor substrate is maintained by said movable plate.
3. A semiconductor substrate jig claimed in claim 2, wherein a suction mechanism for suctioning said expandable member is provided in said movable plate.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A power module adapted to be connected to a voltage source and to supply power to a load, the power module comprising:
a power transistor; and
a gate controller for driving the power transistor;
wherein the gate controller comprises:
a gate transformer, and
an impulse generator that extends a negative drive phase of a gate voltage to the power transistor relative to a positive drive phase of the gate voltage to the power transistor.
2. The power module of claim 1, wherein the impulse generator comprises:
a capacitor in parallel with an input capacitance of the power transistor, and a switching element.
3. The power module of claim 1, wherein the gate transformer includes a low frequency ferrite.
4. A method of driving a power module, the method comprising:
connecting the power module to a voltage source;
supplying power from the power module to a load;
controlling a gate of at least one power transistor of the power module with a gate controller that includes a gate transformer and an impulse generator; and
creating pulses with the impulse generator to drive the gate of the at least one power transistor with a reduced duty cycle.
5. The method of claim 4, further comprising generating a symmetrical square-wave voltage that is applied to the gate transformer.
6. The method of claim 4, wherein creating the pulses includes using a switching element and a capacitor.
7. A method of driving a power module, the method comprising:
connecting the power module to a voltage source;
supplying power from the power module to a load;
controlling a gate of at least one power transistor of the power module with a gate controller that includes a gate transformer and an impulse generator;
creating pulses with the impulse generator to drive the gate of the at least one power transistor with a gate voltage; and
extending a negative drive phase of the gate voltage relative to a positive drive phase.
8. The method of claim 7, further comprising reducing the amplitude of the negative drive voltage.
9. The method of claim 7, further comprising generating a symmetrical square-wave voltage that is applied to the gate transformer.
10. The method of claim 9, further comprising generating the symmetrical square-wave voltage with a frequency that is close to a self resonance of a resonant circuit formed by an input capacitance of the at least one power transistor and a leakage inductance of the gate transformer.
11. The method of claim 7, wherein creating the pulses includes using a switching element and a capacitor.
12. The method of claim 11, wherein creating the pulses includes using a body diode of the switching element.