JESD51-1 集成电路的热测试方法 – 单器件的电学测试法
2.1.1 MEASUREMENT CURRENT CONSIDERATIONS/测量电流
The Measurement Current (I
M
) through the temperature sensing diode must be large enough to obtain a reliable
forward voltage reading not influenced by surface leakage effects but small enough not to cause significant self
heating. The value of I
M
is chosen to be in a range right around the knee of the diode's I-V curve, as shown in
figure 1, and is usually in the 100A to 5 mA range, depending on the diode size. Lower values of current can be
used, but for greatest ease in implementing the measurement and to eliminate potential surface leakage effects
(which can result in significant non-temperature dependent variability between diodes of the same construction
and size) the current is rarely chosen below 100 A and is usually 1 mA. The upper limit on I
M
is determined by
self-heating effects, which in turn are a function of the diode geometry.
通过温度敏感二极管的测量电流(I
M
)必须足够大,以便不受表面漏电影响而获得可靠的正向电压读数,但
是不能太大而引起显著的自热现象。因此,测量电流一般在二极管I-V曲线的转折点附近选择(如图1所示),
这个值通常是100uA到5mA之间,根据二极管的尺寸大小决定。测量电流可以选择较小的数值,但是实现
时为了方便并且排除漏电流的影响(漏电流会导致在相同结构和尺寸的二极管之间显著的非温度相关的测
量结果变化),一般很少选在100uA以下,通常使用1mA。测量电流的上限根据自热效果确定,它是所使用
的二极管的几何尺寸的函数。
Figure 1. - IM selection relative to typical diode I-V Curve
图1 测量电流与典型的二极管I-V曲线的关系
2.1.2 K FACTOR CALIBRATION/K 因子校准
Once the proper value of I
M
is selected, the relationship between the temperature sensing diode forward voltage
and junction temperature is determined by performing a K FACTOR CALIBRATION. During this procedure, the
diode is forward biased with I
M
while inserted into a temperature-controlled environment. The forward voltage
of the diode is recorded for two or more different equilibrium temperature conditions. Because I
M
is specifically
chosen not to cause significant self heating, the environment temperature and junction temperature are taken
to be essentially the same.
在测量电流确定之后,温度敏感二极管正向电压和结温之间的关系就可以通过K因子校准确定下来。在此
过程中,二极管偏置到正向电流I
M
,并将其放置到温度受控的环境下,记录下两个或多个温度平衡条件下
的二极管正向电压。因为所使用的测量电流不会引起显著的自热现象,默认为环境温度和被测结温基本相
同。
Using the diode conduction equation, Equation 5 below, it can be shown
2,3
that for a fixed applied current (I
M
in
this case), the forward voltage will vary linearly with junction temperature. The saturation current (I
0
) expression
is given in Equation 6.
使用二极管的导通方程,如下式(5)所示,在恒定电流情况下,正向电压与结温之间为线性关系。其中饱和
电流I
0
的表达式如式(6)所示。
(5)
22
A.S. Grove, Physics and Technology of Semiconductor Devices , John Wiley & Sons., New York, 1967
3
P.E. Gray & C.L. SearleE, LECTRONIC PRINCIPLES: Physics, Models and Circuits , John Wiley & Sons, Inc., New York, 1969