JPS59108968A - Thermal resistance measurement of semiconductor device - Google Patents

Abstract

PURPOSE:To provide a thermal resistance measurement of a semiconductor device which can be implemented even while the semiconductor device is in operation by incorporating a process of dividing a temperature rising value by a power consumption when the semiconductor device is used continuously. CONSTITUTION:At the step 1, a gain is measured by changing the channel temperature with varying of the source/drain voltage VD or the gate voltage VG of a semiconductor device to be measured to determine a gain vs temperature characteristic l. At the step 2, the gate voltage VG and a high frequency input RFIN are applied continuously with the source-drain voltage VD of an FET transistor 41 maintained at a fixed value to determine the current gain GI and the power consumption PDC. At the step 3, the source-drain voltage VD, the gate voltage VG and the high frequency input RFIN the same as at the step 2 are applied in a pulse to determine the current gain G2. At the step 4, the difference DELTAG is determined between the gains in the two cases at the step 3. At the step 5, the gain vs temperature characteristic l at the step 1 is used to determine a temperature rising value DELTAT corresponding to DELTAG at the step 4. At the step 6, a thermal resistance R is determined from DELTAT and PDC.

Description

[Detailed description of the invention] (1) Technical field of the invention The present invention relates to a method of measuring thermal resistance of a semiconductor device.

In particular, the present invention relates to a method for measuring thermal resistance of a semiconductor device that can be carried out while the semiconductor device is mounted.

(2) Background of the technology Since semiconductor devices are heat generating elements, it is necessary to use them within the permissible temperature rise value.
It is necessary to know the heat dissipation effect, that is, the thermal resistance, of a semiconductor device, especially the thermal resistance in the mounted state. Here ↑, thermal resistance is the amount of heat given to a certain object per unit time (
In a semiconductor device, it is defined as the quotient obtained by dividing the temperature rise value generated due to the amount of heat by the power consumption. [7]The value of this thermal resistance for a single semiconductor device, that is, the value between the channel and the /e hookage, is also important, but the value in the mounted state, that is, the value between the channel and components other than the package, is important. Especially important.

(3) Prior art and problems There are several methods to measure the thermal resistance of a semiconductor device when it is not mounted, such as the ΔVy method and the ΔVB11 method. However, the development of such a method has been desired.

(4) Purpose of the Invention The purpose of the present invention is to meet this demand, and to provide thermal resistance for semiconductor devices that can be implemented not only in the state where the semiconductor device is not mounted, but also in the state in which it is mounted. The objective is to provide a measurement method.

(5) Structure of the Invention The method for measuring thermal resistance of a semiconductor device according to the present invention determines the gain versus temperature characteristic of the semiconductor device to be measured, and also calculates the gain (G process) at a temperature when the semiconductor device is continuously used. ) and the power consumption (Poo), and also the gain (G2) when the semiconductor device is used without temperature rise.
is measured, and the difference (ΔG) between the gain G2 and the gain G1 is determined.
From the difference in gain and the gain vs. temperature characteristic, the temperature rise value (△T
) is calculated 1, and the temperature rise value (△T) is calculated as the power consumption (P
It is composed of ↑ which includes the process of dividing by DO).

The present invention provides that the high frequency power gain of a semiconductor device, such as a gallium arsenide field effect transistor (GaAs FBT), decreases as the channel temperature increases, as shown in FIG. 1, and that the gain vs. temperature characteristic is linear. What is the phenomenon that there is, the output-to-input characteristic (gain) when a semiconductor device is used continuously, and the output-to-input characteristic (gain) when a semiconductor device is used without temperature rise?
As shown in FIG. 2, this method uses the phenomenon of a difference by a specific value (ΔG). Furthermore, if measurements are made using continuous waves, it is possible to measure the above-mentioned values when used continuously, and if measurements are made using pulsed waves, the above-mentioned temperature increase is not caused. It takes advantage of the relationship that it is possible to measure the value when used. In FIG. 2, curves a + b indicate the case where the input signals are a continuous wave input signal and a nosorus input signal, respectively.

Note that the power consumption of semiconductor devices is DC power consumption (
Although generally satisfactory results can be obtained using DC power consumption (Poa), more precisely, power consumption is
pno PRIP
If OUT +Pnyxu is used, the results will be more accurate.

In addition, the above temperature rise value (△T) is a value measured with the ambient temperature as a reference, but it is not based on the ambient temperature, but rather a desired value (△T) between the channel temperature and the ambient temperature.
For example, if it is desirable to find the thermal resistance based on the temperature of the chassis (for example, the chassis temperature), instead of the temperature rise value (△T) above, use △T - Ts. However, if Ts is the temperature at the reference point (for example, the chassis), good.

(6) Embodiments of the Invention Hereinafter, a method for measuring thermal resistance of a semiconductor device according to an embodiment of the present invention will be explained with reference to the drawings. The semiconductor device to be measured is connected as shown in FIG. In the figure, 41 is a field effect transistor iJ 42.43
is an impedance matching circuit, and 44.45 is a resistor. The sources of the four field effect transistors are grounded. Furthermore, at the gate of the field effect transistor 41,
In order to bring this into a normal operating state, the DC voltage VG is divided by resistors 44 and 45 and applied as a gate voltage. Further, a DC voltage VD is applied between the source and drain. The high frequency input is given to the gate of the field effect transistor 41 via the matching circuit 42, and the high frequency output is taken out from the drain of the field effect transistor 41 via the matching circuit 43. Turn on 41
The basics of the -OFF operation are as follows.0 First, the gate voltage ■. If the source-drain voltage VD is changed over a certain range while keeping the value of VD unchanged, the field effect transistor 41 turns ON according to the change.
Turn off.

Further, the signal for turning the field effect transistor 41 ON and OFF is the gate voltage ■ as shown in FIG. It is okay to enter with . That is, the source-drain voltage v,) is assumed to be a constant value, and the gate voltage is set to ■.

There are things that change.

Hereinafter, each step of the thermal resistance measuring method according to the embodiment of the present invention will be explained.

First, as a first step, the gain is measured by variously changing the source-drain voltage VD or gate voltage vG of the semi-integrated body to be measured H=f4, and the channel temperature is varied in various ways, and the gain is measured as shown in FIG. Obtain the gain vs. temperature characteristic (line e). When determining such gain vs. temperature characteristics, the signal input to the semiconductor device under test may be either a ξ pulse-like signal or a continuous signal.

Next, as a second step, the voltage between the source and P-rain of the field effect transistor 41 is determined. Keep the gate voltage ■ at a constant value. and high frequency input RFIN are applied continuously (cw), and the gain (G) and power consumption (
Poa). The radio frequency output (RFOUT) characteristic with respect to the radio frequency input (RFIN) is shown as a curve a in FIG.

As the third stage, the source-drain voltage ■ is the same as in the above case. , gate voltage V. , high frequency input RFIN
is applied in a pulsed manner (for example, pulse width 4 [μ days], duty ratio [ε%]), and the gain (G2) at that time is determined. The radio frequency output (RFOUT) characteristic with respect to the radio frequency input (RFIN) is shown as a curve in FIG.

As the fourth step, the difference in the profit (∆G) in the above two cases is
) is calculated using the following formula.

O, -a,, -ΔG In the fifth step, the temperature increase value (ΔT) corresponding to ΔG obtained in the fourth step is determined by using the gain versus temperature characteristic obtained in the first step.

That is, as shown in FIG. 3, by using the gain vs. temperature characteristic shown in FIG. Find the temperature T corresponding to Gb=(Ga-ΔG).

The difference ΔT (= T-25) between the temperature T and the 2s ('c)
) is the temperature rise value.

In the sixth step, the thermal resistance (R) is determined using the following formula from this temperature increase value (ΔT) and the power consumption (PDO) determined in the second step.

PDO Furthermore, in the above vortex layer, the order of the second stage and the third stage may be reversed.

(7) As described in detail, the present invention provides a method for measuring thermal resistance of a semiconductor device that can be carried out not only when the semiconductor device is not mounted, but also when the semiconductor device is mounted. can be provided.

[Brief explanation of drawings]

Figure 1 is a graph showing the gain vs. temperature characteristics of a semiconductor device, and Figure 2 is a graph showing the trends in input/output characteristics of the semiconductor device for continuous and wave-like high-frequency input signals, such as pulse-like high-frequency input coefficients. It is a graph. Further, FIG. 3 is a graph of gain versus temperature layer characteristics showing a method for determining a temperature upper value according to the present invention, and FIG. 4 is a graph showing a method for measuring thermal resistance of a semiconductor device according to an embodiment of the present invention. FIG. 2 is a circuit diagram showing an implementation state of the semiconductor device.

Claims (1)

[Claims] The gain versus temperature characteristic of the semiconductor device under test is determined, and the gain (
G1) and power consumption (PDO), further measuring the gain (G2) when the semiconductor device is used without temperature increase, and determining the difference between the gain G2 and the gain G1. , from the gain difference and the gain vs. temperature characteristic, the temperature rise value (△
T), and the temperature rise value (△T) is calculated as the power consumption (P).
1. A method for measuring thermal resistance of a semiconductor device, characterized in that the method is divided by: DO).