US 11,079,427 B2Granted

Inspection device, inspection system, intelligent power module, inspection method, and computer program product

AssigneeKabushiki Kaisha Toshiba

InventorsMitsuaki Kato, Akihiro Goryu, Kenji Hirohata

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Abstract

An inspection device comprises: a detecting unit that is connected to a plurality of semiconductor chips having mutually different rates of change of electrical resistance with respect to stress loading direction, and that detects an electrical resistance value of each semiconductor chip from electric current flowing in each semiconductor chip; a first memory unit that is used to hold model data meant for converting an electrical resistance value into a characteristic value indicating at least either temperature, or stress, or strain; a converting unit that converts the electrical resistance value of each semiconductor chip as detected by the detecting unit into the characteristic value using the model data held in the first memory unit; and a second memory unit that is used to store the characteristic value, which is obtained by conversion by the converting unit, as time-series data for each of the plurality of semiconductor chips.

Claims16

Dependent claims

An inspection device comprising:

detecting circuitry connected to a plurality of semiconductor chips having mutually different rates of change of electrical resistance with respect to stress loading direction, the detecting circuitry functioning as a detecting unit to detect an electrical resistance value of each semiconductor chip from electric current flowing in each semiconductor chip;
a memory including a first memory unit to hold model data meant for converting an electrical resistance value into a characteristic value indicating at least either temperature, or stress, or strain;
and
a hardware processor connected to the memory, the hardware processor functioning as a converting unit to:
convert the electrical resistance value of each semiconductor chip as detected by the detecting circuitry into the characteristic value using the model data held in the first memory unit,
store, in a second memory unit included in the memory, the characteristic value as time-series data for each of the plurality of semiconductor chips, and
read out the time-series data from the second memory unit and output the readout time-series data to the outside of the inspection device,
wherein the model data represents a conversion equation for converting rate of change of the electrical resistance value into the characteristic value,
when ΔRon represents amount of change in electrical resistance of each semiconductor chip,
when Ron represents electrical resistance value in state in which no stress is applied to each semiconductor chip, and
when rp represents change rate in electrical resistance in response to application of stress to each semiconductor chip,
the conversion equation is expressed using Equation (1) given below, and
ΔRon=Ron×rp (1)
when α represents coefficient indicating relationship between temperature and stress-resistance change rate,
when β represents coefficient indicating relationship between stress and resistance change rate,
when γ represents coefficient indicating relationship between temperature and heat stress,
when σo represents external force,
when σf represents mounting stress,
when Ti represents junction temperature, and
when T0 represents reference temperature,
the change rate rp in electrical resistance as given in the Equation (1) is expressed using Equation (2) given below
r
p
=
⁢
r
p
⁡
(
σ
x
,
σ
y
,
T
j
)
=
⁢
{
α
x
⁡
(
T
j
-
T
0
)
+
1
}
⁢
β
x
⁢
{
γ
x
⁡
(
T
j
-
T
0
)
+
σ
x
,
f
+
σ
x
,
0
}
+
⁢
{
α
y
⁡
(
T
j
-
T
0
)
+
1
}
⁢
β
y
⁢
{
γ
y
⁡
(
T
j
-
T
0
)
+
σ
y
,
f
+
σ
y
,
0
}
.
(
2
)

123 more elements

An inspection method implemented by a computer, the inspection method comprising:

detecting, from electric current flowing in each of a plurality of semiconductor chips having mutually different rates of change of electrical resistance with respect to stress loading direction, an electrical resistance value of each semiconductor chip;
converting the detected electrical resistance value of each semiconductor chip into a characteristic value, which indicates at least either temperature, or stress, or strain, using model data meant for converting an electrical resistance value into the characteristic value;
storing, in a memory of the computer, the characteristic value, which is obtained by conversion, as time-series data for each of the plurality of semiconductor chips;
and
reading out the time-series data from the memory and outputting the readout time-series data to the outside of the computer,
wherein the model data represents a conversion equation for converting rate of change of the electrical resistance value into the characteristic value,
when ΔRon represents amount of change in electrical resistance of each semiconductor chip,
when Ron represents electrical resistance value in state in which no stress is applied to each semiconductor chip, and
when rp represents change rate in electrical resistance in response to application of stress to each semiconductor chip,
the conversion equation is expressed using Equation (1) given below, and
ΔRon=Ron×rp (1)
when α represents coefficient indicating relationship between temperature and stress-resistance change rate,
when β represents coefficient indicating relationship between stress and resistance change rate,
when γ represents coefficient indicating relationship between temperature and heat stress,
when σo represents external force,
when σf represents mounting stress,
when Tj represents junction temperature, and
when T0 represents reference temperature,
the change rate rp in electrical resistance as given in the Equation (1) is expressed using Equation (2) given below
r
p
=
⁢
r
p
⁡
(
σ
x
,
σ
y
,
T
j
)
=
⁢
{
α
x
⁡
(
T
j
-
T
0
)
+
1
}
⁢
β
x
⁢
{
γ
x
⁡
(
T
j
-
T
0
)
+
σ
x
,
f
+
σ
x
,
0
}
+
⁢
{
α
y
⁡
(
T
j
-
T
0
)
+
1
}
⁢
β
y
⁢
{
γ
y
⁡
(
T
j
-
T
0
)
+
σ
y
,
f
+
σ
y
,
0
.
(
2
)

120 more elements

A computer program product having a non-transitory computer readable medium including programmed instructions, wherein the instructions, when executed by a processor installed in an inspection device that is connected to a plurality of semiconductor chips having mutually different rates of change of electrical resistance with respect to stress loading direction, cause the processor to perform:

detecting, from electric current flowing in each of the plurality of semiconductor chips, an electrical resistance value of each semiconductor chip;
converting the detected electrical resistance value of each semiconductor chip into a characteristic value, which indicates at least either temperature, or stress, or strain, using model data meant for converting an electrical resistance value storing, in a memory of the inspection device, the characteristic value, which is obtained by conversion, as time-series data for each of the plurality of semiconductor chips into the characteristic value;
and
reading out the time-series data from the memory and outputting the readout time-series data to the outside of the inspection device,
wherein the model data represents a conversion equation for converting rate of change of the electrical resistance value into the characteristic value,
when ΔRon represents amount of change in electrical resistance of each semiconductor chip,
when Ron represents electrical resistance value in state in which no stress is applied to each semiconductor chip, and
when rp represents change rate in electrical resistance in response to application of stress to each semiconductor chip,
the conversion equation is expressed using Equation (1) given below, and
ΔRon=Ron×rp (1)
when α represents coefficient indicating relationship between temperature and stress-resistance change rate,
when β represents coefficient indicating relationship between stress and resistance change rate,
when γ represents coefficient indicating relationship between temperature and heat stress,
when σo represents external force,
when σf represents mounting stress,
when Tj represents junction temperature, and
when T0 represents reference temperature,
the change rate rp in electrical resistance as given in the Equation (1) is expressed using Equation (2) given below
r
p
=
⁢
r
p
⁡
(
σ
x
,
σ
y
,
T
j
)
=
⁢
{
α
x
⁡
(
T
j
-
T
0
)
+
1
}
⁢
β
x
⁢
{
γ
x
⁡
(
T
j
-
T
0
)
+
σ
x
,
f
+
σ
x
,
0
}
+
⁢
{
α
y
⁡
(
T
j
-
T
0
)
+
1
}
⁢
β
y
⁢
{
γ
y
⁡
(
T
j
-
T
0
)
+
σ
y
,
f
+
σ
y
,
0
.
(
2
)

119 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/117,279Filed 30 Aug 2018
Priority: JP JP2018-00667818 Jan 2018
Published: US 2019/0219628 A118 Jul 2019
Granted: 3 Aug 2021
Term ends: Not estimatedThe source records don’t support an estimate.

Classification25 codes

G01K 7/16
Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using…: using…
G01R 31/2607
Testing of individual semiconductor devices: circuits therefor
G01B 7/18
For measuring the deformation in a solid, e.g. by resistance strain gauge: using change in resistance
G01K 7/01
Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using…: using…

Family

US 2019/0219628 A1Pre-grant publication · published 18 Jul 2019
US 11,079,427 B2This patent

From the US filing history. Foreign family members aren’t listed.

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