JP2002243810A - Semiconductor device and inspecting method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device capable of easily inspecting an analogue circuit in a semiconductor device in which a digital circuit and the analogue circuit are mixed and reducing inspection time and inspection cost and an inspecting method thereof. SOLUTION: An output value of the digital circuit 100 in inspection on the digital circuit 100 is inputted to the analogue circuit 101 to execute inspection on the analogue circuit 101. An output signal of the analogue circuit 101 is outputted by a selector switch 106 at any given time, and the voltage of the output signal is stored in a storage device 108 and outputted to external terminals 103-105 by a selector switch 107 at any given time. As it is possible to simultaneously execute inspection on the digital circuit and the analogue circuit and to easily execute a test on the analogue circuit by this, it is possible to reduce inspection time and inspection cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection method for easily measuring electric characteristics of a semiconductor device in which a digital circuit and an analog circuit are mounted, and judging whether or not the characteristics are satisfied.

[0002]

2. Description of the Related Art In a conventional inspection of a semiconductor device in which a digital circuit and an analog circuit are mixed, a digital circuit and an analog circuit are separately inspected. In particular, in order to guarantee the electrical characteristics of the analog circuit, since the electrical characteristics are measured by a dedicated inspection device to determine whether the standard is satisfied, the inspection time and cost are increased. As a conventional technique for shortening the inspection time, JP-A-200
No. 0-78008 and those described in JP-A-11-98015 are known. However, in order to measure and determine an analog signal as it is, a test of an analog circuit alone is necessary.

FIG. 5 is a circuit diagram of a conventional semiconductor device in which a digital circuit and an analog circuit are mixedly mounted. A digital circuit 501 and an analog circuit 502 are connected to external terminals via a test circuit 500, respectively. Testing is performed on each of the digital and analog circuits.

As described above, in the prior art, a digital circuit and an analog circuit are individually inspected. In particular, a special inspection machine is required to determine whether or not an analog signal satisfies a standard of electrical characteristics. Therefore, the inspection time and the inspection cost are increased.

[0005]

SUMMARY OF THE INVENTION A semiconductor device according to the present invention,
And the inspection method, in order to solve the above problem, in a semiconductor device in which a digital circuit and an analog circuit are mixed, it is possible to easily inspect an analog circuit that requires a long-term inspection with a dedicated inspection machine, inspection time, It is another object of the present invention to provide a semiconductor device capable of reducing inspection costs and an inspection method thereof.

[0006]

According to a first aspect of the present invention, there is provided a method for testing a semiconductor device, comprising the steps of: performing a test on a semiconductor device in which a digital circuit and an analog circuit capable of inputting a signal from the digital circuit are mixed; Performing a test of a digital circuit, and simultaneously, inputting a signal for operating the analog circuit from the digital circuit to the analog circuit;
Selecting a voltage of the output signal at an arbitrary time from the voltage of the output signal of the analog circuit and outputting the voltage from an external terminal of the semiconductor device in order to perform a simple inspection of the analog circuit.

According to a second aspect of the present invention, there is provided a method of inspecting a semiconductor device.
2. The method of claim 1, wherein the inspection of the digital circuit is performed by a scan test. The semiconductor device according to claim 3, further comprising: a digital circuit; and an analog circuit configured to input at least one of output signals of the digital circuit in order to perform a simple inspection of the analog circuit simultaneously with the inspection of the digital circuit. A first switch including a switch for selecting and outputting an output signal of each output terminal of the analog circuit at an arbitrary time, a storage device for storing a voltage of an output signal of the analog circuit, and each of the storage devices And a second switch configured to output the voltage of the output signal stored in the external output terminal to the external output terminal at an arbitrary time interval.

As described above, in a semiconductor device in which a digital circuit and an analog circuit are mixed, the inspection of the digital circuit and the analog circuit can be performed simultaneously, and the analog circuit can be easily inspected.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) Hereinafter, a case will be described where the output signal of the analog circuit is a sine wave and three arbitrary measurement times are used to determine whether the standard circuit is satisfied.

FIG. 1 is a circuit configuration diagram of a semiconductor device according to the first embodiment of the present invention, and FIG. 2 is a waveform diagram of an output from an analog circuit. In FIG. 1, a part of an output terminal of the digital circuit 100 is connected to an input terminal of the analog circuit 101, and each input terminal is connected to a test circuit 102.
Is also connected. Each output terminal of the analog circuit 101 has a changeover switch 106 connected at an arbitrary time;
A storage device 108 stores each signal voltage from the output terminal at the time when the changeover switch 106 is connected, and a changeover switch 107 for outputting the output of the storage device 108 at an arbitrary time. 104,
Output to 105. In the case of the first embodiment, the output of the analog circuit 101 is selected at three arbitrary times by the changeover switch 106, and the output of the storage circuit 108 is selected.
To memorize. The signal voltage stored in the storage device 108 for each output terminal is selected from three arbitrary times by the changeover switch 107 and output to the external terminals 103, 104, and 105.

First, in order to supply an input signal for testing the analog circuit 101 from an output signal of the digital circuit 100, an input pattern of the digital circuit 100 is set and input from the external terminals 109, 110 and 111. Next, the result of operating the digital circuit 100 is output to the external terminal 1.
Take out the digital circuit 10
At the same time as performing the test of 0, the output signal of the digital circuit 100 is input and the analog circuit 101 is operated to perform the test. Here, the switches of the changeover switch 106 for each terminal are sequentially switched at arbitrary preset times indicated by t1, t2, and t3 in FIG.
08 stores the output signal voltage of the analog circuit 101, respectively. Next, at predetermined time intervals, the signal voltages from the analog circuit stored in the storage device 108 are sequentially switched over three switches of the changeover switch 107 arranged for each terminal, and the external terminals 103, 104, 1
05, V1, V2, V3 in FIG.
Is measured, and it is determined whether the standard is satisfied.

This makes it possible to easily inspect the electrical characteristics of the analog circuit simultaneously with the inspection of the digital circuit. (Embodiment 2) Next, a semiconductor device inspection method will be described.
The case where the scan test is performed simultaneously will be described with reference to the drawings.

FIG. 3 is a flow chart for testing a semiconductor device according to the second embodiment of the present invention, and FIG. 4 is a circuit configuration diagram of the semiconductor device. First, in advance, the digital circuit 100
In order to use a part of the scan test result as the input pattern for the inspection of the analog circuit 101, the scan test result is input to the scan test input pattern 302 of the digital circuit 100 so as to match the input timing of the analog circuit 101.
Is generated (S301). Next, a scan test input pattern 302 for inspecting the digital circuit 100 is input from the external terminals 109, 110, and 111 (S303), and the result of the scan test of the digital circuit 100 is taken out from the external terminals 112, 113, and 114 to be digitalized. Circuit 1
At the same time as performing the inspection of step S00 (S304), the pattern output by the scan test of the digital circuit 100 is input to the analog circuit 101 to operate the analog circuit 101 (S305), and the standard for setting the output signal voltage in advance is determined. External terminals 103 and 10
4, 105 (S306), and an inspection of electrical characteristics is performed (S307).

Thus, the electrical characteristics of the analog circuit can be easily inspected from the output signal voltage of the analog circuit simultaneously with the failure detection test of the digital circuit.

[0015]

As described above, according to the semiconductor device of the present invention and the inspection method therefor, the output value of the digital circuit in the inspection of the digital circuit is input to the analog circuit, the analog circuit is inspected, and the analog circuit is inspected. Since the output value at an arbitrary time can be selected from the output signals and output from the external terminal, the inspection of the digital circuit and the analog circuit can be performed at the same time, and the test of the analog circuit can be easily performed. , And inspection costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a semiconductor device according to a first embodiment of the present invention;

FIG. 2 is an output waveform diagram from an analog circuit according to the first embodiment of the present invention.

FIG. 3 is a flowchart of an inspection of a semiconductor device according to a second embodiment of the present invention;

FIG. 4 is a circuit configuration diagram of a semiconductor device according to a second embodiment of the present invention;

FIG. 5 is a circuit configuration diagram of a conventional semiconductor device in which a digital circuit and an analog circuit are mixed.

[Explanation of symbols]

 Reference Signs List 100 digital circuit 101 analog circuit 102 test circuit 103 external terminal 104 external terminal 105 external terminal 106 changeover switch 107 changeover switch 108 storage device 109 external terminal 110 external terminal 111 external terminal 112 external terminal 113 external terminal 114 external terminal 302 scan test input Pattern 500 test circuit 501 digital circuit 502 analog circuit

Claims (3)

[Claims] When inspecting a semiconductor device in which a digital circuit and an analog circuit capable of inputting a signal from the digital circuit are mixed, an inspection of the digital circuit is performed, and at the same time, a signal at which the analog circuit operates is converted into a digital signal. A step of inputting a signal from a circuit to the analog circuit, and selecting an output signal voltage at an arbitrary time from among the voltage of the output signal of the analog circuit to perform a simple inspection of the analog circuit. And a step of outputting from the semiconductor device. 2. The method according to claim 1, wherein the inspection of the digital circuit is performed by a scan test. 3. A digital circuit, an analog circuit for inputting at least one of output signals of the digital circuit to perform a simple inspection of the analog circuit simultaneously with the inspection of the digital circuit, and the analog circuit A first switch composed of a changeover switch that selects and outputs an output signal of each output terminal at an arbitrary time, a storage device that stores a voltage of an output signal of the analog circuit, and a storage device that is stored in each of the storage devices. A second switch comprising a changeover switch for outputting a voltage of an output signal to an external output terminal at an arbitrary time interval.