参数资料
型号: 8923-2G
厂商: Aavid Thermalloy
文件页数: 9/116页
文件大小: 0K
描述: CARD GUIDE EJECTOR PULLER
标准包装: 1,000
附件类型: 卡导轨
其它名称: 035096
How To Select a Heat Sink
How to select a heat sink
The basic equation for heat transfer or power dissipation may be stated as follows:
PD =
Δ T
Σ R θ
Where:
PD = the power dissipated by the semiconductor device in watts.
Δ T = the temperature difference of driving potential which causes the flow of heat.
Σ R θ = the sum of the thermal resistances of the heat flow path across which Δ T exists.
The above relationship may be stated in the following forms:
PD =
TJ–TA
R θ JC + R θ CS + R θ SA
PD =
TC–TA
R θ CS + R θ SA
PD =
TS–TA
R θ SA
Where:
TJ = the junction temperature in ° C (maximum is usually stated by the manufacturer of the semiconductor device).
TC = case temperature of the semiconductor device in ° C.
TS = temperature of the heat sink mounting surface in thermal contact with the semiconductor device in ° C.
TA = ambient air temperature in ° C.
R θ JC = thermal resistance from junction to case of the semiconductor device in ° C per watt
(usually stated by manufacturer of semiconductor device).
R θ CS = thermal resistance through the interface between the semiconductor device
and the surface on which it is mounted in ° C per watt.
R θ SA = thermal resistance from mounting surface to ambient or thermal resistance of heat sink in ° C per watt.
The above equations are generally used to determine the required thermal resistance of the heat sink (R θ SA),
since the heat dissipation, maximum junction and/or case temperature, and ambient temperature are known or set.
Figure 1 indicates the location of the various heat
flow paths, temperatures and thermal resistances.
FIGURE 1
Mounting surface
(cooler/dissipator)
Interface
Atmosphere
or ambient
The common practice is to represent the system with
a network of resistances in series as shown in Figure 2.
FIGURE 2
Junction
(heat source)
T
A
TJ
TC
TS
TA
P
D
P
D
Semiconductor case
R θ JC
R θ CS
R θ SA
R
θ CS
R
θ SA
Heat flow path mounting
surface to ambient, equation (3)
R
θ JC
T
J
T
T
C
S
Heat flow path case
to ambient equation (2)
Heat flow path junction
to ambient, equation (1)
T
A
AMERICA
USA Tel: +1 (603) 224-9988 email: info@aavid.com
ASIA
Singapore Tel: +65 6362 8388 email: sales@aavid.com.sg
www.aavidthermalloy.com
EUROPE
Italy Tel: +39 051 764011 email: sales.it@aavid.com
United Kingdom Tel: +44 1793 401400 email: sales.uk@aavid.com
Taiwan Tel: +886(2) 2698-9888 email: sales@aavid.com.tw
9
相关PDF资料
PDF描述
3-640595-4 CONN RECEPT 4POS 26AWG MTA156
FAD1-09225DBHW12 FAN 92.5X25MM 24VDC BALL WIRE
1300550016 CONN RJ45 RCPT ENET PCB
3-644563-7 CONN RECEPT 7POS 24AWG MTA100
2-1676625-6 RES 900 OHM 25W 5% WW LUG
相关代理商/技术参数
参数描述
89233 制造商:NTE Electronics 功能描述:Cap Ceramic 0.0033uF 50V YSP 10% (8 X 4mm) Radial 5.1mm 85°C
89-233 制造商:Ideal Industries Inc 功能描述:COVER, CLEAR ( 2 POLE)
89234-510-1129 SOD6747-2.0 功能描述:罩类、盒类及壳类产品 6.74 x 4.77 x 2.18" GRAY INDOOR/OUTDOOR RoHS:否 制造商:Bud Industries 产品:Boxes 外部深度:6.35 mm 外部宽度:6.35 mm 外部高度:2.56 mm NEMA 额定值: IP 等级: 材料:Acrylonitrile Butadiene Styrene (ABS) 颜色:Red
8923464003 功能描述:热收缩管和套管 VERSAFIT-1/8-4-SP RoHS:否 制造商:3M Electronic Specialty 类型:Tubing 材料:Polyolefin, Flexible 颜色:Clear 最低收缩温度:+ 100 C 恢复直径: 长度:100 ft 内径:1.5 in 收缩率:2:1
89235-3100 制造商:MOLEX 功能描述: