JP2961368B1 - Semiconductor device test equipment - Google Patents

Abstract

A level of an output signal of a semiconductor element is set to a predetermined level in a short time. SOLUTION: A gain control voltage of a semiconductor element 1 to be tested is swept by a sweep power supply 21, a level of an output signal of the semiconductor element 1 is detected by a level detector 23, and an output voltage of the level detector 23 is preset. Reference voltage V
r is compared by a voltage comparator 24, and when the two become equal, a stop signal is output to the sweep power supply 21 to stop the sweep, and the output voltage is held, whereby the semiconductor device 1
Is fixed at a predetermined level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device test apparatus (hereinafter simply referred to as a test apparatus) for testing a semiconductor element such as a high-frequency amplifier used in a mobile communication system or the like. Related to technology.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing line, manufactured semiconductor devices are tested by a test apparatus to select non-defective products.

FIG. 4 shows a configuration of a conventional test apparatus 10 installed in such a production line. The test apparatus 10 is provided with an automatic loading device 11. The automatic loading device 11 loads one semiconductor element to be tested into the mount 12, and when the test of this semiconductor element is completed,
Remove the tested semiconductor device from the mount 12,
The operation of loading the next semiconductor element to be tested is repeated.

The mount 12 has a signal output terminal 12a, a signal input terminal 12b, and a control voltage output which can be connected to a signal input pin 1a, a signal output pin 1b, a gain control pin 1c, and power supply pins 1d and 1e of the semiconductor device 1, respectively. Terminal 12
c and power supply terminals 12d and 12e.

A signal output terminal 12 a of the mount 12 is connected to a signal generator 13, and a signal output from the signal generator 13 is input to the semiconductor device 1. The signal input terminal 12b has a characteristic value of an output signal of the semiconductor element 1,
For example, a power meter 15 and a spectrum analyzer 16 are connected via a signal distributor 14 as measuring devices for measuring electric power, spectrum, and the like.

A variable power supply 17 for setting the gain (bias voltage) of the semiconductor device 1 is connected to the control voltage output terminal 12 c of the mount 12, and the power supply terminals 12 d and 12 e of the mount 12 are connected to the semiconductor device 1. An element power supply 18 for supplying power is connected.

A measuring instrument such as an automatic loading device 11, a signal generator 13, a power meter 15, a spectrum analyzer 16, and a variable power supply 17 have a GPIB interface, and a test control device comprising a computer via a control bus thereof. 19 is connected.

The test controller 19 variably controls the frequency and level of the output signal of the signal generator 13 or the output voltage Va of the variable power supply 17 for the semiconductor element 1 loaded on the mount 12 by the automatic loading device 11. The measurement of a plurality of items determined in advance is performed, and the quality is determined.

[0009] Among these measurement items, there are items to be measured while fixing the level of the output signal of the semiconductor element to a predetermined level.

As described above, as a method of fixing the level of the output signal of the semiconductor element to a predetermined level, in the semiconductor element 1 having the gain control pin 1c as described above, the output is changed by varying the input signal level of the semiconductor element 1. In addition to the method of adjusting the output to a predetermined level, the voltage applied to the gain control pin 1c of the semiconductor element 1 is varied, that is, the gain of the semiconductor element is adjusted to adjust the output to a predetermined level.

FIG. 5 shows a processing procedure of the test control device 19 when the gain of the semiconductor element is varied to adjust the level of the output signal to a predetermined level.

As shown in FIG. 5, the test control device 1
9 sets the output voltage Va of the variable power supply 17 to the initial voltage Vs via the GPIB control bus (S1), and then instructs the power meter 15 to read (S2), which is sent from the power meter 15. An incoming read value is received (S3), and it is determined whether the read value is equal to a level obtained by subtracting the loss of the signal distributor 14 from a predetermined level to be fixed (S4). The process of varying the voltage Va (S5) is repeated to bring the level of the output signal of the semiconductor element 1 to a predetermined level, and then perform the spectrum measurement (S6).

[0013]

However, as described above, the test control device 19 monitors the read value of the power meter 15 via the control bus of the GPIB while controlling the variable power supply 1.
In the conventional test apparatus which changes the output voltage of the semiconductor element 1 to a predetermined level by changing the output voltage of the semiconductor device 7, a very long time (1 second or more) is required for this change, and the test efficiency is reduced. And the efficiency of the entire line is reduced.

An object of the present invention is to provide a semiconductor device test apparatus which solves this problem and can set the output signal level of a semiconductor device to a predetermined level in a short time.

[0015]

In order to achieve the above object, a semiconductor device test apparatus according to the present invention comprises a signal input terminal (1).
2a), a signal output terminal (12b), a control voltage input terminal (12c), and a power supply terminal (12e, 12f),
The signal input pin, signal output pin,
A mount (12) for connecting a gain control pin and a power supply pin to the signal input terminal, the signal output terminal, the control voltage input terminal and the power supply terminal, respectively, and applying a signal to the semiconductor device under test via the signal input terminal of the mount; An input signal generator (13) sweeps an output voltage from a preset initial voltage when a start signal is received, stops an output voltage when a stop signal is received, and holds the output voltage at that time. A sweep power supply (21) for inputting the output voltage to a gain control pin of a semiconductor device to be tested via a control voltage input terminal of the mount, and a semiconductor to be tested via a signal output terminal of the mount. A signal distributor (2) that receives an output signal of an element and distributes and outputs the signal to a plurality of paths.
2), a measuring device (15, 16) for measuring a characteristic value of a signal output from the signal distributor, and a level for detecting a level of a signal output from the signal distributor to a different path from the measuring device. A detector (23); a reference voltage generator (25) for generating a reference voltage equal to a voltage output from the level detector when a signal of a predetermined level is input to the signal distributor; A voltage comparator (24) for comparing the output voltage of the voltage detector with the reference voltage, and receiving the output signal of the voltage comparator, and when the output voltage of the level detector becomes equal to the reference voltage, A stop signal generator (26) for outputting a stop signal to the sweep power supply when performing a test that requires that the output signal level of the semiconductor element to be tested be fixed at the predetermined level. Outputs a signal, and a testing control apparatus (30) to start the test from the check that the stop signal is output from the stop signal generator after the output of the start signal.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a semiconductor device test apparatus 20 according to an embodiment of the present invention. In FIG. 1, an automatic loading device 11, a mount 12, a signal generator 1
3, the signal distributor 14, the power meter 15, the spectrum analyzer 16 and the element power supply 18 are the same as those of the test apparatus described in FIG.

A sweep power supply 21 is connected to a control voltage input terminal 12c of the mount 12 of the test apparatus 20.

The sweep power supply 21 is connected to a test control device 3 described later.
When a start signal from 0 is received, the output voltage Va is rapidly swept from a preset initial voltage Vs, for example, in a direction to increase the voltage, and when a stop signal from a stop signal generator 25 described later is received, the output voltage Va is reduced. It is configured to stop the sweep and maintain the output voltage at that time,
The output voltage Va is input to the gain control pin 1c of the semiconductor device 1 under test via the control voltage input terminal 12c.
The sweep speed of the sweep power supply 21 sweeps, for example, a range of several volts at several tens of milliseconds. Here, it is assumed that the gain of the semiconductor element 1 increases as the voltage of the gain control pin 1c increases.

The sweep power supply 21 has a function of outputting the voltage specified by the test control device 30 in addition to the function of sweeping the output voltage as described above.

On the other hand, the signal output terminal 12b of the mount 12
A signal distributor 22 is provided between the signal distributor 14. The signal distributor 22 distributes the signal output from the signal output terminal 12b to the measuring device side and the level detector 23.

The level detector 23 detects the level of the signal output from the signal distributor 22 and inputs it to the voltage comparator 24.

The voltage comparator 24 compares the output voltage Vd of the level detector 23 with the reference voltage Vr output from the reference voltage generator 25, and outputs a binary signal according to the comparison result. Here, the voltage comparator 24 outputs a low-level signal when the output voltage Vd of the level detector 23 is lower than the reference voltage Vr, and outputs a high-level signal when the output voltage Vd is higher than the reference voltage Vr.

The reference voltage Vr is the output of the level detector 23 when a signal of a predetermined level defined as the level of the output signal of the semiconductor element 1 at the time of spectrum measurement or the like is input to the signal distributor 22. It is set in advance to be equal to the voltage.

The output of the voltage comparator 24 is input to a stop signal generator 26. The stop signal generator 26
A stop signal is output to the sweep power supply 21 at the timing when the output of the voltage comparator 24 is inverted from the low level to the high level.

Automatic loading device 11, signal generator 13, power meter 15, spectrum analyzer 16, sweep power supply 21
The reference voltage generator 25 is connected to the test control device 30 via a GPIB control bus.

Each time the semiconductor device 1 to be tested is mounted on the mount 12 by the automatic loading device 11, the test control device 30 performs various measurements on the semiconductor device 1 (for example, input / output characteristics, gain frequency characteristics, spectrum, etc.). Characteristics, etc.) to determine the quality of the semiconductor element.

As described above, the test control device 30 performs various automatic measurements on the loaded semiconductor element 1, but it is not necessary that the output signal level of the semiconductor element 1 be fixed at a predetermined level. Is performed, it is specified that the sweep power supply 21 outputs a voltage for gain control necessary for the measurement.

In the case where the output signal level of the semiconductor device 1 needs to be fixed at a predetermined level, for example, when the spectrum characteristic of the output signal of the semiconductor device 1 is measured by the spectrum analyzer 16, the test control device 30
Performs processing according to the flowchart of FIG.

Here, the level of the output signal of the signal generator 13 is set in advance to a certain level, and the initial voltage Vs of the sweep power supply 21 determines the gain of the semiconductor element 1 and the input signal of the semiconductor element 1. It is assumed that the voltage is set to a voltage corresponding to a gain which is smaller than the magnification of the predetermined level with respect to the level and which is not largely different.

As shown in FIG. 2, the test control device 3
0 first outputs a start signal to the sweep power supply 21 (S
1) Wait for a predetermined time T (S2). The time T is set to a time (for example, 50 mS) necessary and sufficient for the output voltage Va of the sweep power supply 21 to change from the initial voltage Vs to a voltage that makes the level of the output signal of the normal semiconductor element equal to or higher than a predetermined level. ing.

Upon receiving the start signal, the sweep power supply 21 outputs the output voltage Va input to the gain control pin 1c of the semiconductor device 1.
At the time t ₀ as shown in FIG.
To start sweeping in the direction of higher voltage.

The output voltage Va of the sweep power supply 21 is equal to the initial voltage V
s, the output voltage Vd of the level detector 23
3 is lower than the reference voltage Vr as shown in FIG. 3B, the voltage comparator 24 outputs a low-level signal as shown in FIG. 3C.

Then, the output voltage Va of the sweep power supply 21 increases, and the output voltage Vd of the level detector 23 changes to the reference voltage Vr.
At time t ₁ , the output voltage V of the level detector 23 approaches
When d slightly exceeds the reference voltage Vr, the output of the voltage comparator 24 is inverted from a low level to a high level.

For this reason, the stop signal generator 26 outputs, for example, a pulse-like stop signal as shown in FIG. 3D to the sweep power supply 21 at time t _1, and the output voltage Va of the sweep power supply 21 becomes It is held at a voltage at time t _1.

As described above, since the sweep speed of the sweep power supply 21 is high, the output voltage Vd of the level detector 23 is high.
Takes about several tens of milliseconds (several hundreds of milliseconds at most) until the voltage becomes substantially equal to the first reference voltage Vr.
It is much shorter than setting the level by exchanging commands via the GPIB control bus.

The test controller 30 confirms that the stop signal has been output from the stop signal generator 26 within a predetermined time after outputting the start signal (S3), and instructs the power meter 15 to read. (S4), the read value is received (S5), and it is confirmed that the read value is equal to a level obtained by subtracting the distribution loss of the two signal distributors 14 and 22 from a predetermined level to be fixed (S4). S6), spectrum measurement is performed (S7).

If it is determined in step S6 that the value read by the power meter 15 is not equal to the level obtained by subtracting the distribution loss of the two signal distributors 14 and 22 from the predetermined level, it is determined that there is an abnormality in the measurement system. As an alarm.

In step S3, if the stop signal is not output within a predetermined time, the sweep power supply 21
Instructs to stop the sweep (S8), instructs the power meter 15 to read in the same manner as described above (S9), receives the read value (S10), and reads the two signals from the predetermined level. It is determined whether or not the level is smaller than the level obtained by reducing the distribution loss of the distributors 14 and 22 (S11). If the level is smaller, it is determined that there is a problem in the semiconductor element itself, and the element is defective (S12).
And if it is large, an alarm is generated assuming that there is an abnormality in the measurement system.

Next, a method of determining the initial voltage Vs and the reference voltage Vr of the sweep power supply 21 of the semiconductor device test apparatus will be described.

For example, for testing a new semiconductor device,
When determining the initial voltage Vs and the reference voltage Vr, the test controller 30 sets the sweep power supply 21 to the GPIB control mode, loads the sample of the semiconductor device into the mount 12, and monitors the power meter 15 while monitoring the power meter 15. 21 is gradually increased from, for example, 0 V, and the power meter 15
10d from the level obtained by subtracting the distribution loss of the two signal distributors 14 and 22 from the predetermined level at which the read value of
The output voltage Va when the voltage is about B lower is determined as the initial voltage Vs for this semiconductor device, and this is stored in the memory in the test control device 30.

Then, the output voltage Va is further increased so that the read value of the power meter 15 becomes equal to a level obtained by subtracting the distribution loss of the two signal distributors 14 and 22 from a predetermined level to be fixed.

In this state, while monitoring the output of the stop signal generator 26, the output voltage of the reference voltage generator 25 is
Until the stop signal is output from the stop signal generator 26, the voltage is gradually decreased from the maximum value, and the voltage at which the stop signal is output is determined as the reference voltage Vr for this semiconductor device. The set value of the device 25 is stored in a memory in the test control device 30 and set in the reference voltage generator 25 at the time of actual measurement.

As described above, if the initial voltage and the reference voltage for a new semiconductor element are determined and set in the sweep power supply 21 and the reference voltage generator 25 at the time of measurement,
As described above, the output signal level of the semiconductor element can be fixed at a predetermined level only by outputting a start signal when performing measurement with the level of the output signal of the semiconductor element fixed at a predetermined level.

As described above, the semiconductor device test apparatus according to the embodiment sweeps the gain control voltage of the semiconductor device under test and detects the level of the output signal of the semiconductor device by the level detector 23.
When the output voltage of the level detector 23 becomes equal to a preset reference voltage, the sweeping of the sweep power supply 21 is stopped and the output voltage is held, whereby The level of the output signal is fixed at a predetermined level.

For this reason, if the reference voltage is calibrated in advance for the type of the semiconductor element, the output signal of the semiconductor element can be reduced to a predetermined level for a short time only by outputting a start signal to the sweep power supply during an actual test. , And the test efficiency is greatly improved as compared with a method in which the level is driven by exchanging commands via the GPIB control bus.

In the above-described embodiment, the case where one measurement is performed with the output level of the semiconductor device fixed is described. However, there are a plurality of items of measurement performed with the output signal level of the semiconductor device fixed, and the fixed measurement is performed. If the levels to be measured are different, the initial voltage and the reference voltage may be obtained in advance for each measurement item, and these voltages may be switched when the measurement of each measurement item is performed.

[0047]

As described above, the semiconductor device test apparatus of the present invention comprises a sweep power supply for receiving a start signal to sweep a gain control voltage of a semiconductor device under test, and a sweep power supply for outputting a signal output from the semiconductor device under test. A level detector that detects the level, a voltage comparator that compares the output voltage of the level detector with a reference voltage, and outputs a stop signal to the sweep power supply when the output voltage of the level detector becomes equal to the reference voltage A stop signal generator for stopping the sweep of the gain control voltage to perform a measurement that needs to fix the level of the output signal of the semiconductor device under test to a predetermined level. Is output.

For this reason, it is not necessary to perform the run-in control by the test controller for each semiconductor element to be tested, and the output signal level of the semiconductor element can be brought to a predetermined level in a short time only by outputting the start signal. Can be fixed,
Test efficiency is greatly improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure of a main part of the embodiment.

FIG. 3 is a signal diagram for explaining the operation of the embodiment;

FIG. 4 is a block diagram showing a configuration of a conventional device.

FIG. 5 is a flowchart showing a processing procedure of a main part of the conventional apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 semiconductor device 11 automatic loading device 12 mount 13 signal generator 14 signal distributor 15 power meter 16 spectrum analyzer 20 semiconductor device test device 21 sweep power supply 22 signal distributor 23 level detector 24 voltage comparator 25 reference voltage generator 26 stop Signal generator 30 Test control device

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) G01R 31/26 G01R 31/28 H01L 21/66

Claims (1)

(57) [Claims] A signal input terminal (12a), a signal output terminal (12b), a control voltage input terminal (12c), and a power supply terminal (12e, 12f). Pin, a gain control pin and a power supply pin are connected to the signal input terminal, the signal output terminal, the control voltage input terminal and the power supply terminal, respectively.
2), a signal generator (13) for inputting a signal to a semiconductor device to be tested through a signal input terminal of the mount, and receiving a start signal, sweeping an output voltage from a preset initial voltage, and stopping. When a signal is received, the sweep of the output voltage is stopped and the output voltage at that time is held, and the output voltage is input to the gain control pin of the semiconductor device under test via the control voltage input terminal of the mount. A power supply (21), a signal distributor (22) for receiving an output signal of the semiconductor device under test via a signal output terminal of the mount, distributing the signal to a plurality of paths, and outputting the signal from the signal distributor. A measuring device (15, 16) for measuring a characteristic value of a signal; a level detector (23) for detecting a level of a signal output from the signal distributor to a path different from the measuring device; A reference voltage generator (25) for generating a reference voltage equal to a voltage output from the level detector when a signal of a predetermined level is input to the signal divider; an output voltage of the level detector and the reference voltage And a stop signal that receives an output signal of the voltage comparator and outputs a stop signal to the sweep power supply when an output voltage of the level detector becomes equal to the reference voltage. Generator (2
6) and when performing a test that requires that the output signal level of the semiconductor element to be tested be fixed at the predetermined level, output a start signal to the sweep power supply and stop the stop after outputting the start signal. A test control device (30) for starting the test after confirming that a stop signal has been output from a signal generator.