
356 Heat Transfer: Thermal Management of Electronics
The equations for internal points 2 through 6 plus one equation for each boundary
point 1 and 7 constitute a set of seven equations for seven temperatures T
1
to T
7
. This
set of equations can be written in the following matrix form
−
−
−
−
−
aa
11 12
00000
1210000
0121 00 0
001210 0
0001 21 00
00001 21
00000
76 77
−
−
aa
=
−
T
T
T
T
T
T
T
c
1
2
3
4
5
6
7
1
ggx k
gx k
gx k
gx k
()/
()/
()/
()/
∆
∆
∆
∆
2
2
2
2
2
2
2
2
−
−
−
−−
gx k
c
()/∆
2
7
2
, (14.19)
where constants a
11
, a
12
, a
76
, a
77
, c
1
, and c
7
depend on the boundary conditions. For
example, if the left side of the wall is at un ...