Measurement method and measurement device

Patent metadata

Field	Value
Publication number	US-2024280628-A1
Application number	US-202318237292-A
Country	US
Kind code	A1
Filing date	Aug 23, 2023
Priority date	Feb 16, 2023
Publication date	Aug 22, 2024
Grant date	—

Abstract

A measurement method includes determining a first relationship by measuring a reverse recovery charge of a semiconductor element at a plurality of conditions of a measurement device. The measurement device has mutually-different parasitic inductances at the plurality of conditions. The semiconductor element includes a diode component. The first relationship is between the parasitic inductance and a measured value of the reverse recovery charge. The method includes estimating a true value of the reverse recovery charge when the parasitic inductance is zero based on the first relationship.

First claim

What is claimed is:

1 . A measurement method, comprising:
determining a first relationship by measuring a reverse recovery charge of a semiconductor element at a plurality of conditions of a measurement device, the measurement device having mutually-different parasitic inductances at the plurality of conditions, the semiconductor element including a diode component, the first relationship being between the parasitic inductance and a measured value of the reverse recovery charge; and estimating a true value of the reverse recovery charge when the parasitic inductance is zero based on the first relationship.

2 . The method according to claim 1 , wherein
the estimating of the true value of the reverse recovery charge includes:
determining a second relationship and a third relationship at the plurality of conditions of the measurement device having mutually-different parasitic inductances, the second relationship being between a current change rate and a charge transferred in an initial half period of a current oscillation, the third relationship being between the current change rate and a charge transferred in an entire duration of the current oscillation;
setting a saturated current change rate as the current change rate at an intersection of the second and third relationships in a graph illustrating a relationship between the current change rate and the charge;
determining a fourth relationship between the saturated current change rate and the parasitic inductance;
setting a saturated parasitic inductance by determining the parasitic inductance corresponding to an arbitrary value of the saturated current change rate based on the fourth relationship; and
setting the true value as the charge corresponding to the saturated parasitic inductance based on the first relationship.

3 . The method according to claim 2 , further comprising:
determining the true value corresponding to an arbitrary value of the current change rate based on a fifth relationship between the saturated current change rate and the true value at the plurality of conditions of the measurement device having mutually-different parasitic inductances.

4 . The method according to claim 1 , wherein
the estimating of the true value of the reverse recovery charge includes:
determining a second relationship between a current change rate and a surge voltage at the plurality of conditions of the measurement device having mutually-different parasitic inductances;
setting a saturated current change rate as the current change rate corresponding to a reference potential in the second relationship, the reference potential being set between an anode potential and a cathode potential of a power supply;
determining a third relationship between the saturated current change rate and the parasitic inductance;
setting a saturated parasitic inductance by determining the parasitic inductance corresponding to an arbitrary value of the saturated current change rate based on the third relationship; and
setting the true value as the charge corresponding to the saturated parasitic inductance based on the first relationship.

5 . The method according to claim 4 , further comprising:
determining the true value corresponding to an arbitrary value of the current change rate based on a fifth relationship between the saturated current change rate and the true value at the plurality of conditions of the measurement device having mutually-different parasitic inductances.

6 . The method according to claim 1 , wherein
the estimating of the true value of the reverse recovery charge includes:
determining a second relationship and a third relationship at the plurality of conditions of the measurement device having mutually-different parasitic inductances, the second relationship being between a current change rate and a charge transferred in an initial half period of a current oscillation, the third relationship being between the current change rate and a charge transferred in an entire duration of the current oscillation; and
setting a saturated current change rate as the current change rate at an intersection of the second and third relationships in a graph illustrating a relationship between the current change rate and the charge, and setting the true value as a charge at the intersection.

7 . The method according to claim 6 , further comprising:
determining the true value corresponding to an arbitrary value of the current change rate based on a fourth relationship between the saturated current change rate and the true value at the plurality of conditions of the measurement device having mutually-different parasitic inductances.

8 . The method according to claim 1 , wherein
the semiconductor element is a field-effect transistor, and the method further comprises:
measuring an output charge amount of the semiconductor element; and
determining a difference by subtracting the measured output charge amount from the true value.

9 . The method according to claim 8 , wherein
the output charge amount is estimated to be a charge contributing to a boost of a drain-source voltage of the semiconductor element, and the difference is estimated to be a charge caused by recombination and discharge of carriers in the semiconductor element.

10 . A measurement device, comprising:
a direct current power supply connected to a semiconductor element, the semiconductor element including a diode component; a switching element connected in series to the direct current power supply and the semiconductor element; a fixed inductance connected in parallel to the semiconductor element; and a variable inductance connected in series with a semiconductor element in a circuit, the circuit including the direct current power supply, the semiconductor element, and the switching element.

Assignees

• Toshiba Kk
• Toshiba Electronic Devices & Storage Corp

Inventors

• Hara Takuma
• Ohguro Tatsuya
• Nakajima Shigeru
• Miyashita Katsura
• Oomuro Yasuhisa

Classifications

• G01R31/26

  Testing of individual semiconductor devices (testing of photovoltaic devices H02S50/10; testing or measuring during manufacture or treatment {H10P74/00}) · CPC title

• G01R31/2621 Primary

  for testing field effect transistors, i.e. FET's · CPC title