JP2001344999A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recognize required burn-in test items and to set automatically a signal used for performing its item in individual semiconductor device having a non-volatile memory. SOLUTION: This device is provided with plural test circuits 11-13 generating a signal used for performing each item of burn-in test, and control means 20, 40 reading out information whether a test is performed or not for respective items of a burn-in test from the prescribed region of a non-volatile memory, judging whether a burn-in test is performed or not for respective items based on the information, and enabling a test circuit to operate corresponding to items judged as that a burn-in test is to be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having a non-volatile memory, and more particularly, to a semiconductor device compatible with a plurality of types of burn-in tests.

[0002]

2. Description of the Related Art Generally, a semiconductor device molded by passing a wafer sorting test is subjected to a first molding test, a burn-in test, and a second molding test. However, the first mold test may be omitted. Here, the burn-in test is to store the semiconductor device in a constant temperature chamber set at a high temperature or a low temperature and apply a predetermined power supply voltage and a test signal in order to secure the reliability of the semiconductor device before shipment. Test. Thus, stress is applied to the semiconductor device, and an initial failure of the semiconductor device is detected. The burn-in test includes a static test in which a fixed voltage is applied to each input terminal, and a dynamic test in which a dynamic signal is input to each input terminal to operate a circuit in the semiconductor device.

Conventionally, when performing a dynamic burn-in test, a test board for a burn-in test has been created for each product so that a signal at a predetermined timing can be input, and the test is performed. Using this test board, the level and timing of the input signal are set for each input terminal of the semiconductor device.

[0004]

However, when changing, adding or deleting a test item of a burn-in test, a test board is changed in order to change the level and timing of an input signal, or a burn-in test is performed. In order to change the circuit configuration, it is necessary to re-create a chip of a semiconductor device.

[0005] Further, even in the same model, the quality is not stable in the early stage of product manufacture, so it is necessary to perform a burn-in test for many items. When the quality becomes stable, the number of test items for which the burn-in test can be omitted can be reduced, and the time for the burn-in test can be reduced. In that case, it was necessary to change the test board. On the other hand, even if the quality is stabilized, if the process is improved to improve the yield and the characteristics,
In some cases, it is desired to confirm the initial failure by increasing the items of the burn-in test again. However, conventionally, it has not been possible to quickly respond to such a case.

Incidentally, Japanese Patent Application Laid-Open Publication No. Hei 7-134160 discloses that even when a semiconductor device having a different function is subjected to a burn-in test, the burn-in test can be performed using the same burn-in test board. A burn-in test board for supplying a power supply voltage and various signals to a semiconductor device to be tested via a programmable logic device is disclosed.

Japanese Patent Application Laid-Open No. 10-160787 discloses that
Even if semiconductor devices with different packages exist, in order to carry out these burn-in tests simultaneously, the pattern generator is controlled based on the type and appearance of the semiconductor device,
An IC test apparatus for transmitting a test pattern signal to a burn-in board is described.

However, even if only the burn-in test equipment (test board) is improved, it is not possible to recognize burn-in test items required for individual lots or individual semiconductor devices. The burn-in test apparatus had to be set by judging whether or not to execute the item.

In view of the above, the present invention recognizes a burn-in test item required for each semiconductor device and writes in advance a signal used to execute the burn-in test item into each semiconductor device. Another object of the present invention is to provide a semiconductor device which eliminates the need to set test items when performing a burn-in test.

[0010]

In order to solve the above problems, a semiconductor device according to the present invention is a semiconductor device having a non-volatile memory, and outputs a signal used to execute each item of a burn-in test. A plurality of test circuits to be generated and information on whether or not to perform a test for each item of the burn-in test are read from a predetermined area of the nonvolatile memory, and whether or not to perform the burn-in test for each item based on the information is determined. And control means for enabling a test circuit corresponding to the item determined to perform the burn-in test.

Here, the control means selects one of a plurality of address signals sequentially output from the plurality of test circuits, and the control means reads out from the nonvolatile memory corresponding to the address signal selected by the selector. Based on the information, it may be determined whether or not to perform a burn-in test on the item, and if it is determined that the burn-in test is to be performed, a control circuit that enables a test circuit corresponding to the item to operate may be included.

According to the present invention configured as described above, in a semiconductor device having a non-volatile memory, a required burn-in test item is recognized, and a signal used for executing the burn-in test item is individually set in each semiconductor device. By writing to the apparatus, it is possible to eliminate the need to set test items when performing a burn-in test.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a semiconductor device according to one embodiment of the present invention. This semiconductor device has a flash memory 30 as a non-volatile memory.
have. The flash memory 30 has a memory cell array unit for storing a manufacture code, a device code, and the like. Hereinafter, this portion is referred to as an information array portion. Since the information array section is arranged adjacent to the main body of the memory cell array section, there are considerable areas not used for storing data therein. For example, when the storage capacity of the entire flash memory is 4 megabits, information of about 256 bytes to 1 kbyte can be stored in the information array section. It is byte order. Therefore, in the present invention, test information as to whether or not each burn-in test item should be executed is stored in a vacant area of the information array unit, for example, as a flag for each semiconductor device.

The semiconductor device also has a burn-in test sequence circuit 10 for generating a signal used to execute each item of the burn-in test. Here, the burn-in test sequence circuit 10 outputs the signal used to execute the first item of the burn-in test from the first test circuit 11 to the N-th burn-in test (N is an arbitrary natural number). Up to an N-th test circuit 13 that generates signals used to execute the items (1) to (3). The selector 20 is connected to the burn-in test control circuit 4.
One of the first to Nth test circuits 11 to 13 is sequentially selected in accordance with a control signal output from 0, and an address signal generated by the test circuit is applied to the flash memory 30. In accordance with the address signal, test information indicating whether or not a burn-in test needs to be performed for the item is read from the information array section of the flash memory 30 and output to the burn-in test control circuit 40. The burn-in test control circuit 40 determines whether or not to execute the burn-in test item based on the test information. To execute the item, the first to Nth test circuits 1 included in the burn-in test sequence circuit 10
An enable signal is output to a selected one of 1-13.

Next, the operation of the semiconductor device in the burn-in test will be described in detail with reference to FIGS. When a clock signal is input from the test board to the semiconductor device, a burn-in test is started in the semiconductor device. The test information stored in the information array section in the flash memory 30 is read for each test item, and the burn-in test control circuit 40 determines whether or not to execute the test item.

This operation is performed first in burn-in test item 1
Started from. FIG. 2 shows the operation in the burn-in test item 1. In step S1, the selector 20 selects the test item 1 and outputs the address 1 based on the control signal output from the burn-in test control circuit 40. Based on this, test item 1 stored at address 1 in the information array section
Is read out.

Next, in step S2, the burn-in test control circuit 40 determines whether or not to execute the test item 1 based on the test information on the test item 1. If it is determined that test item 1 is to be executed, step S3
Proceed to. In step S3, the burn-in test control circuit 40 outputs an enable signal to the first test circuit 11 included in the burn-in test sequence circuit 10, and generates a signal used for test item 1. That is, an input signal corresponding to the test item 1 is generated in the semiconductor device, and the test of the item 1 is performed. Thereafter, the process proceeds to step S4.

If it is determined that test item 1 is not to be executed, the process proceeds to step S4, and the test of item 1 is not performed. In step S4, the first test circuit 11 outputs an end signal, and the burn-in test control circuit 40 shifts to the operation of test item 2.

By repeating such operations, the operations for the burn-in test items 1 to N are completed as shown in FIG.

[0020]

As described above, according to the present invention, in a semiconductor device having a nonvolatile memory, a necessary burn-in test item is recognized, and a signal used for executing the burn-in test item is individually specified in advance. By writing the data in the semiconductor device, it is possible to eliminate the necessity of setting test items when executing the burn-in test. Therefore, even if the burn-in test item is changed, it is not necessary to change the burn-in test environment such as the test board and the timing of the input signal.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a semiconductor device according to one embodiment of the present invention.

FIG. 2 is a flowchart showing an operation in a burn-in test item 1 of the semiconductor device of FIG. 1;

FIG. 3 is a flowchart showing an operation in a burn-in test of the semiconductor device of FIG. 1;

[Description of Signs] 10 Burn-in test sequence circuit 11 to 13 First to 1st to execute each item of burn-in test
N test circuit 20 selector 30 flash memory 40 burn-in test control circuit

Claims (2)

[Claims] 1. A semiconductor device having a non-volatile memory, comprising: a plurality of test circuits for generating signals used to execute each item of a burn-in test; Reads information on whether or not to perform a test for each item, determines whether or not to perform a burn-in test for each item based on the information, and operates a test circuit corresponding to the item determined to perform a burn-in test. Control means for enabling the semiconductor device. 2. A selector for sequentially selecting one of a plurality of address signals respectively output from the plurality of test circuits, and the nonvolatile memory corresponding to the address signal selected by the selector. A control circuit that determines whether or not to perform a burn-in test on the item based on the information read from the device, and, when it is determined that the burn-in test is performed, enables a test circuit corresponding to the item to operate. The semiconductor device according to claim 1, wherein: