Thermal Resistance of Packages
4401035 NC
Thermal Resistance
of Packages
Similarly, thermal resistance from junction
to case is denoted by θ JC , and defined by
θ JC = ( T j – T c ) ⁄ P d ;
here, T c is the case temperature (˚C) at
the external surface of the package.
(for additional information,
contact an AMI Package Engineer)
With the thermal resistance of the package
available, the junction temperature and
maximum power dissipation can be calculated using the same equation in different
forms:
T j = ( θ JA × P d ) + T a , and
Introduction
The purpose of this section is to provide
thermal data on semiconductor packages
(hereafter called package). Thermal resistance of a package is a measure of the
temperature change across a package
caused by power dissipation of the packaged semiconductor device. Power dissipation is the transference of heat
generated by the device during operation.
Thermal resistance is an indication of the
heat transfer from the semiconductor
device through the package materials out
to the environment in terms of temperature
per unit of power. Thermal resistance data
can be used by the designer or the customer to estimate the junction temperature
of their die in operation.
P d = ( T j – T a ) ⁄ θ JA .
Values for θ JA are available for most packages. However, θ JC and ‘ θ JA with airflow’
data have limited availability. Additional
information is available in the “AMI Packaging Capabilities” brochure, or can be
Thermal resistance from junction to ambient is denoted by θ JA , and defined by
θ JA = ( T j – T a ) ⁄ P d ,
where:
• T j is the junction temperature of the
device (˚C);
•
T a is the ambient temperature (˚C);
•
P d is the power dissipation (W).
With the units indicated above, θ JA will
have units of degrees Celsius per watt (˚C/
W).
133
Thermal Resistance of Packages
4401035 NC
obtained from the factory.
134
Thermal Resistance of Packages
4401035 NC
THERMAL RESISTANCE θ JA (˚C/W)
PACKAGE versus DIE SIZE
3 values: (@zero airflow) / (@300 fpm) / (@600 fpm)
D
PACKAGE
0.062"
I
E
S
I
Z
E
0.120"
0.240"
0.360"
0.480"
CPGA 84
45/33/27
34/23/18
28/18/13
22/15/8
CPGA 180
36/25/21
27/18/15
20/14/10
19/12/5
CPGA 224
33/26/19
26/21/17
23/17/14
17/10/3
CQFP 84
75/66/57
52/45/41
41/30/28
CQFP 132
56/54/44
52/36/30
33/27/24
38/33/29
31/23/19
CQFP 196
22/17/14
JLDCC 28
102/??/63
83/??/51
JLDCC 44
68/62/50
63/50/38
54/41/30
JLDCC 68
46/38/32
36/27/19
35/26/20
JLDCC 84
47/37/32
33/26/22
30/26/18
LCC 28
109/82/74
83/59/53
57/39/33
LCC 52
86/66/62
58/45/41
43/34/31
LCC 84
63/53/47
57/44/38
30/23/19
29/22/17
PQFP 128
ALLOY 42
74/65/62
59/50/43
48/41/32
PQFP 144
ALLOY 42
76/68/62
61/51/45
52/41/26
TQFP 32, 48
(7 x 7)
79/70/61
TQFP 44, 64
(10 x 10)
68/59/49
TQFP 44,
64, 80, 100
(14 x 14)
52/43/37
135
Thermal Resistance of Packages
4401035 NC
THERMAL RESISTANCE θ JC (˚C/W), PACKAGE versus DIE SIZE
D
PACKAGE
120
240
I
360
E
S
375
I
400
Z
220 x
410
E
270 x
410
CPGA 120
CPGA 180
N/A
<1
2
2
2
<1
CPGA HS 208
CQFP 144
<1
LCC 24
1
LCC 28
38
17
LCC 52
25
13
LCC 84
31
7
5
MQUAD 160
2
MQUAD 208
3
MQUAD 304
2
PQFP 44
24
15
PQFP 52
22
14
PQFP 80
10
PQFP 120
13
PQFP 128
11
PQFP 144
10
7
PQFP 160
8
PQFP 208a
11
PQ2 160
28
<1
5
<1
TQFP 32, 48 (7 x 7)
17
TQFP 44, 64 (10 x 10)
29
24
TQFP 44, 64, 80, 100
(14 x 14)
8
8
TQFP 176 (24 x 24)
5
136
Thermal Resistance of Packages
4401035 NC
a. NOTE: These values are from different sources.
MAXIMUM POWER DISSIPATION ( P d ) ESTIMATES, (W)
BASED ON MAXIMUM JUNCTION TEMPERATURE, 150 ˚C
PACKAGE versus PINCOUNT
PACKAGE
8
CERDIP
14
16
0.8
0.9
P
I
N
C
O
U
N
T
18
20
22
24
28
40
44
48
1.3
1.4
1.7
1.9
1.3
1.4
1.7
1.3
0.9
1.0
1.1
68
84
2.1
2.6
2.7
1.2
LCC 20
PDIP
52
1.1
1.2
1.2
1.9
PLCC
1.4
1.5
1.7
2.0
PREJLDCC
0.8
1.2
1.7
1.7
S-BRAZE
1.1
SOIC
1.2
1.2
1.3
1.3
1.4
1.1
1.6
1.8
1.2
TQFP
1.1
P
PACKAGE
84
CPGA
1.7
CQFP
1.0
PPGA
TQFP
1.9
132
I
N
176
C
O
U
180
N
T
196
2.2
1.4
3.0
2.1
1.2
2.3
137
224
Thermal Resistance of Packages
4401035 NC
B
PACKAGE
O
10 x 10
D
Y
14 x 20
S
I
Z
E
28 x 28
M-QUAD
2.8
PQ2
4.4
PQFP A42
0.8
1.1
1.0
PQFP CU
1.3
1.7
1.9
138