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| 型号： | 18448 |
| 英文描述： | Microprocessor Family CPU Thermal Management Application Note? 126KB (PDF) |
| 中文描述： | 微处理器系列CPU散热管理应用笔记？ 126KB（PDF格式） |
| 文件页数： | 6/10页 |
| 文件大小： | 126K |
| 代理商： | 18448 |
AMD
CPU Thermal Management
5
Where Q is the quantity of heat in calories. Thus, P
equals the power dissipation in watts.
Equation 3 shows that:
Equation 3 illustrates that thermal resistance is a func-
tion of the geometry and thermal conductivity of the de-
vice, varying inversely with cross sectional area.
Therefore, assuming that larger chip sizes are con-
tained in larger packages, it can be concluded that the
larger the device package area, the lower the thermal
resistance.
This can also be shown by understanding the concept
of thermal spreading. Heat spreads both laterally and
vertically through the IC layers, primarily by conduction.
A cross sectional view of the die mounted on a substrate
package is shown in Figure 7. The spread angle varies
for each type of material.
In a small package with restricted thermal spreading,
more heat builds up within the package area (i.e., a
higher thermal constant). While in a larger package, in-
creasing the area beyond full spreading does not affect
the thermal constant because the area normal to the
heat flow does not increase.
The graph in Figure 8a shows the relationship between
thermal resistance (
θ) and the device package area (A).
Figure 8b shows the
θjc versus the ratio of thickness (X)
to the area (A).
Figure 7. Spread Angles (A1<A<A2)
Figure 8. Thermal Resistance Curves
The challenge in computing the thermal resistance of
the layers of a packaged device is in finding the bound-
aries with which to define the area of heat. This is not
an easy task because the spread angle of heat varies
for each type of material, increasing with larger thermal
conductivity. Table 1 shows some spread angles of var-
ious materials.
—
The model thus far has provided a means for predicting
thermal conditions for a constant power input. In the
case of a transient response to a pulse input of power
or a series of pulses, thermal capacitance is introduced.
When the die is subjected to a short pulse of power, the
layers below act as a thermal capacitor, absorbing and
storing the thermal energy. Upon termination of the
pulse, the die cools and the thermal energy is dissipated
P
cal
w
=
atts
sec
=
θ
T2
T1
–
() Pd
=
θ
A1
A
A2
θ
Restricted Thermal Spreading
Full Thermal Spreading
Table 1. Material Spread Angles
Material
Material Spread Angles
Silicon
40°
BeO
60°
Al2O3
25°
Kovar
25°
Epoxy
0°
Eutectic
0°
Copper
70°
Aluminum
65°
Thickness to Area Ratio (x/A)
–10
10
30
50
70
90
110
130
0
0.2
0.4
0.6
0.8
Th
erm
a
lRes
ist
anc
e
(
θjc)
a. Thermal Resistance versus Area
Area (in. Square)
0
10
20
30
40
50
60
0.128
0.13
0.185
0.211
0.372
0.438 0.537
Th
er
m
a
l
Re
si
sta
n
c
e
(
θjc
)
b. Thermal Resistance versus Thickness
APPENDIX
相关PDF资料 |
PDF描述 |
|---|---|
| 1845E | Optoelectronic |
| 1845G | Optoelectronic |
| 1845H | Optoelectronic |
| 1847E | Optoelectronic |
| 1847G | Optoelectronic |
相关代理商/技术参数 |
参数描述 |
|---|---|
| 1844800000 | 制造商:Weidmuller 功能描述:CONN TERM BLOCKS 27 POS 5.08MM SLDR ST TH 10A - Bulk 制造商:Weidmuller 功能描述:LP3R 5.08/27/90 3.2SN OR |
| 1844808 | 功能描述:20 位 端接块 接头，公引脚，带罩（4 面） 0.100"（2.54mm） 90°，直角 通孔 制造商:phoenix contact 系列:COMBICON DMC 包装:带卷（TR） 零件状态:新产品 类型:接头，公引脚，带罩（4 面） 针脚数:20 每级针脚数:10 级别数:2 间距:0.100"（2.54mm） 针座方向:90°，直角 插线入口:- 端子类型:焊接 安装类型:通孔 电流 - IEC:6A 电压 - IEC:160V 电流 - UL:6A 电压 - UL:150V 线规或范围 - AWG:- 线规或范围 -?mm2:- 颜色:黑 工作温度:- 触头配接表面处理:金 特性:固定焊尾 标准包装:300 |
| 1844810000 | 制造商:Weidmuller 功能描述:CONN TERM BLOCKS 33 POS 5.08MM SLDR ST TH 10A - Bulk 制造商:Weidmuller 功能描述:LP3R 5.08/33/90 3.2SN OR |
| 1844811 | 功能描述:22 位 端接块 接头，公引脚，带罩（4 面） 0.100"（2.54mm） 90°，直角 通孔 制造商:phoenix contact 系列:COMBICON DMC 包装:带卷（TR） 零件状态:新产品 类型:接头，公引脚，带罩（4 面） 针脚数:22 每级针脚数:11 级别数:2 间距:0.100"（2.54mm） 针座方向:90°，直角 插线入口:- 端子类型:焊接 安装类型:通孔 电流 - IEC:6A 电压 - IEC:160V 电流 - UL:6A 电压 - UL:150V 线规或范围 - AWG:- 线规或范围 -?mm2:- 颜色:黑 工作温度:- 触头配接表面处理:金 特性:固定焊尾 标准包装:300 |
| 1844820000 | 制造商:Weidmuller 功能描述:CONN TERM BLOCKS 36 POS 5.08MM SLDR ST TH 10A - Bulk 制造商:Weidmuller 功能描述:LP3R 5.08/36/90 3.2SN OR |
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