JPS63113368A - Measurement of semiconductor device - Google Patents

Abstract

PURPOSE:To enable inspection of power, being one of AC items, among DC items, by applying a DC positive bias voltage to a normal phase input and a DC negative bias voltage to a negative phase input sequentially to measure a pseudo-AC power. CONSTITUTION:A DC positive bias voltage with a ground potential as reference is applied to a normal phase terminal 1a to measure a DC positive voltage V1 developing at a load R. Then, a DC negative bias voltage with the ground potential as reference likewise is applied to a negative phase input terminal 1b to measure a DC negative voltage V2 developing at the load R. Then, when DC waveforms of the DC voltages V1 and V2 are combined, one cycle of an AC waveform with peak values V1 and V2 are obtained in a virtual manner. Then, V0=+ or -(P0R)<1/2> is set from a power P0 and the value V0 is compared with the values V1 and V2. This enables judgement on the propriety of a power the element needs.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring power, which is one of the alternating current characteristics of a semiconductor device having differential inputs.

For example, in audio linear power ICs, the amplifier is directly connected from the input to the output, so a differential amplifier circuit is used in the input stage, so there is no effect of DC drift on the output due to temperature changes or power supply fluctuations. That's what I do.

After the above power linear RC with differential input is completed as a product, the AC/DC and current characteristics are inspected. First, a DC signal is applied to the differential input and DC items such as the total current and bias point voltage are measured. Then, an AC signal is applied to the differential input to measure AC items such as power, frequency band, and distortion rate. As a specific example of the above characteristic test, measurement of AC power is shown in FIG. 2. In the figure, (1) is a linear I
C, (la) (lb) (lc) are the positive phase input, negative phase input and output terminals of the linear IC (1), respectively;
(2) is an AC signal source connected to the positive phase input terminal (1a), (3) is a power supply that supplies power to the output stage of the linear IC (1),
(C) is a feedback capacitor connected to the negative phase input terminal (1b), and (R) is a load connected to the output terminal (1c). Although not shown in the actual measurement in the above configuration, the feedback capacitor (C)
In addition, input/output coupling capacitors, bypass capacitors, power supply smoothing capacitors, etc. are connected to linear ICs (1).
After connecting the rated load to the load (R) and supplying the rated input AC signal to the positive phase input terminal (1a) to charge each of the above capacitors, the voltage appearing at the load (R) From the measurement of (V), it is determined whether it has power -(P).

By the way, when testing the characteristics of DC items in the above-mentioned linear IC characteristic test, once the measuring device is set, there is no need to switch the measuring device even if the item changes, and it is not necessary to change the measuring device even if the item changes. The capacitors attached externally to the elements have a small capacity and are not necessarily required, so the time required for testing is relatively short.On the other hand, when testing the characteristics of AC items, the measuring equipment and load are changed each time the item changes, so the test time is relatively short. The power must be turned off or lowered, which increases the time required for inspection. Moreover, charging time is required for a capacitor externally attached to the element, which lowers the index.

In order to measure the AC characteristics of a semiconductor device having a differential input, the present invention sequentially applies a DC positive bias voltage to the positive phase input and a DC negative bias voltage to the negative phase input, and connects it to the output terminal. The present invention is characterized in that pseudo AC power is measured from the positive and negative voltages appearing on the load and the load resistance value to determine whether or not the semiconductor device has power greater than the rated value.

A DC positive bias voltage is sequentially applied to the positive phase input of a semiconductor device with an earthwork differential input, and a DC negative bias voltage is applied to the negative phase input to measure pseudo AC power, and one of the inspection items for AC characteristics is Performed by characteristic test.

1. A method for measuring a semiconductor device according to the present invention will be explained below with reference to FIG. The same reference numerals as in Figure 2 indicate the same thing.
In the figure, (1) is linear IC1 (la) (lb)
(lc) is the positive phase input of linear IC (1),
Reverse phase input and output terminals, (3) are linear ICs (1)
The power supply connected to the output stage of, (R) is the output terminal (IC)
This is the load connected to the

Based on the above configuration, first, a DC positive bias voltage based on, for example, the ground potential is applied to the positive phase input terminal (1a), and the DC positive voltage (1) appearing at the load (R) is measured. Next, a negative DC bias voltage based on the ground potential is similarly applied to the negative phase input terminal (1b), and a negative DC voltage (v2) appearing on the load (R) is measured. Then, the DC voltage (Vl
) (V2), a pseudo AC waveform of -period of the peak value (Vl) (V2) is obtained. Therefore,
If the power is (P), then the power (P) from ■-Sat JV positive
), the voltage (V) corresponds to the required power (
By setting Vo-±571 from Po) and comparing Vo with the values of ■1 and ■2, vl>JKK and V2<
- If the condition 71 is satisfied, it can be determined that the element has the necessary power (P), otherwise it is determined to be defective. In addition, the input terminal (
1a) By increasing the bias voltage applied to (1b), it is possible to know the maximum peak value of the actual output AC waveform. In this way, the power test, which is one of the AC items in the characteristic test of the linear IC (1), can be performed as part of the DC items in the previous stage, and defective products can be removed at that stage.

According to the present invention, power, which is one of the AC items, can be tested among the DC items in the previous stage when testing the characteristics of linear ICs with differential inputs, so that defects can be detected immediately. Since the time required for characteristic inspection can be reduced, the technical index can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram of an application example showing a semiconductor device measurement method according to the present invention, and FIG. 2 is a circuit diagram of an application example showing a conventional semiconductor device measurement method. (1) ---Semiconductor device, (1a) --- Positive phase input, (lb) --- Negative phase input, (1c) --- Output terminal, (R) --- Load.

Claims (1)

[Claims] (1) When measuring the AC characteristics of a semiconductor device with differential input, a DC positive bias voltage is sequentially applied to the positive phase input and a DC negative bias voltage is applied to the negative phase input, and the voltage appears on the load connected to the output terminal. 1. A method for measuring a semiconductor device, characterized in that pseudo AC power is measured from positive and negative voltages and the load resistance value to determine whether or not the semiconductor device has power greater than a rated value.