US 2026/0287489 A1Published application

The diffusivity measurement algorithm of a two-dimensional heat dissipation device

OwnerHong-Long CHENinventor

Life of this patent

Estimating the term…

Loading patent…

Abstract

The present invention is related to the diffusivity measurement algorithm of a two-dimensional heat dissipation device. The one-dimensional algorithm can only be applied to heat pipes. The two-dimensional heat diffusion rate algorithm and measurement method are developed specifically for vapor chambers, 3DVC and other products. On the bottom surface of the vapor chamber of a heat dissipation module, select two measuring points from the edge of the heat source to the outside of the base plate, and then measure the temperature of the two measuring points separately, and through equation (1), the heat diffusion rate or a value of the vapor chamber can be obtained. Equation (1) is the analytical solution obtained after solving the two-dimensional energy equation. By applying this algorithm, the test instrument can measure two-dimensional products with two-dimensional area diffusion physical phenomena such as vapor chamber, 3DVC, and cold plate.

A method for measuring the transient heat diffusivity of a VC/thermal module/cold plate, using equation (1) as the main core calculation program of the measuring instrument, and equations (2) and (3) for obtaining the M value in the steady-state range, comprising:

θ
⁡
(
R
,
τ
)
=
I
1
(
M
)
⁢
K
0
(
MR
)
+
I
0
(
MR
)
⁢
K
1
(
M
)
M
⁡
(
I
1
(
M
)
⁢
K
1
(
aM
)
-
I
1
(
M
)
⁢
K
1
(
aM
)
)
+
∑
n
=
1
∞
A
n
[
J
0
(
λ
n
⁢
R
)
⁢
Y
1
(
λ
n
⁢
a
)
-
J
1
(
λ
n
⁢
a
)
⁢
Y
0
(
λ
n
⁢
R
)
]
⁢
e
-
(
M
2
+
λ
n
2
)
⁢
τ
(
1
)
A
n
=
(
2
⁢
πλ
⁡
(
2
⁢
(
I
1
(
a
⁢
M
)
⁢
K
1
(
M
)
-
I
1
(
M
)
⁢
K
1
(
a
⁢
M
)
)
⁢
M
2
+
πλ
2
(
J
1
(
λ
)
⁢
Y
1
(
a
⁢
λ
)
-
J
1
(
a
⁢
λ
)
⁢
Y
1
(
λ
)
)
)
)
/
(
M
2
(
M
2
+
λ
2
)
⁢
(
I
1
(
a
⁢
M
)
⁢
K
1
(
M
)
-
I
1
(
M
)
⁢
K
1
(
a
⁢
M
)
)
⁢
(
π
2
⁢
λ
2
(
(
Y
0
(
λ
)
2
+
Y
1
(
λ
)
2
)
⁢
J
1
(
a
⁢
λ
)
2
+
J
1
(
λ
)
2
)
⁢
Y
1
(
a
⁢
λ
)
2
)
-
4
)
)
(
5
)
in
⁢
which
θ
⁡
(
R
,
τ
)
=
T
⁡
(
t
)
-
T
∞
(
q
/
k
)
⁢
r
a
,
M
=
h
kt
b
⁢
r
a
,
R
=
r
r
a
,
τ
⁢
α
⁢
t
r
a
2
,
α
=
r
a
2
⁢
τ
t
;
in which:
M is the ratio of convection intensity to thermal conductivity, h is the convection heat transfer coefficient, K is the thermal conductivity coefficient, q is the input heat flux, ra is the characteristic radius, θ is the dimensionless temperature, T is the temperature (° C.), τ is the dimensionless time, t is the time (seconds), R is the dimensionless relative position (r/ra), λn is the Eigenvalue, An is the Eigen term, α is the ratio of the heat source radius to the base plate radius (rb/ra), and α is the final heat diffusivity to be obtained;
substituting the temperature and distance of the first measuring point R1 and the second measuring point R2 into the following equations (2) and (3) to calculate and obtain the M value (the ratio of thermal convection coefficient to conductivity) of the VC/thermal module/cold plate:
θ
⁡
(
R
1
,
∞
)
=
I
1
(
M
)
⁢
K
o
(
MR
1
)
+
I
o
(
MR
1
)
⁢
K
1
(
M
)
M
⁡
(
I
1
(
M
)
⁢
K
1
(
aM
)
-
I
1
(
aM
)
⁢
K
1
(
M
)
)
;
(
2
)
θ
⁡
(
R
2
,
∞
)
=
I
1
(
M
)
⁢
K
o
(
MR
2
)
+
I
o
(
MR
2
)
⁢
K
1
(
M
)
M
⁡
(
I
1
(
M
)
⁢
K
1
(
aM
)
-
I
1
(
aM
)
⁢
K
1
(
M
)
)
;
(
3
)
substituting the obtained distance between M and the first measuring point R1 and the temperature T1 at a certain transient moment t1 into equation (1) to obtain the value of the heat diffusivity coefficient α, which is used to represent the transient heat diffusivity of the heat dissipation module.

486 more elements

Abstract

Claims2