JPH06194410A - Burn-in apparatus - Google Patents

Abstract

PURPOSE:To improve the analyzing efficiency of failures of a burn-in apparatus without making the apparatus considerably complicated or large in scale, etc. CONSTITUTION:An ammeter 5 is interposed between a terminal (a) of a burn-in board 1 and a fuse 3, and also an ammeter 6 is provided between a terminal (b) and a driver 2. An electric resistance between the terminals (a) and (c) is measured from the indicated value of the ammeter 5and a voltage of a power source VDD. A voltmeter 4 monitors whether a normal voltage is impressed to the terminal (b). An electric resistance between the terminals (b) and (c) is measured from the indicated value of the ammeter 6 and that of the voltmeter 4. Based on the measured values of the electric resistances, it is detected that a failure is given rise to in the burn-in board 1 or an IC chip mounted on the board 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a burn-in device for screening by operating an IC chip in an overloaded state, and particularly to improve the efficiency of failure analysis.

[0002]

2. Description of the Related Art Burn-in is one of the screening methods for reducing the initial failure rate of IC chips, and a burn-in device for executing burn-in is generally a burn-in board on which a plurality of IC chips are mounted. A plurality of IC chips are mounted, and the IC chips can be operated under an overload condition of a predetermined temperature (for example, 125 ° C.) and a predetermined voltage (for example, 7 V).

FIG. 2 shows a part of the structure of a conventional burn-in system, in which one burn-in board 1 is provided with a power source V.
It is a circuit diagram of a portion that supplies _DD and a clock signal CLK. That is, the burn-in board 1 has three terminals a, b and c, the terminal a is connected to the power supply V _DD , and the terminal b is connected to the output side of the driver 2 which is driven according to the clock signal CLK. The terminal c is connected to the ground. A fuse 3 is provided between the terminal a and the power supply V _DD as a measure against an excessive current generated when the defective IC chip mounted on the burn-in board 1 is destroyed.
Also, the burn-in board 1 is connected to the output side of the driver 2.
A voltmeter 4 is provided to monitor whether the correct voltage is applied to the.

[0004]

However, in the conventional configuration as shown in FIG. 2, a defect that has occurred in the burn-in board 1 or the IC chip during burn-in is caused by the disconnection of the fuse 3 or the voltmeter 4. However, a large current below the level at which the fuse 3 is disconnected cannot be detected by the fuse 3, and the electrical characteristics of the burn-in board 1 or the IC chip mounted on the burn-in board 1 are not detected. Is changed by the driving capability of the driver 2 and a slight change does not appear in the voltmeter 4,
Only a very serious abnormality could be detected during burn-in. In other words, if the fuse 3 is blown due to a slight increase in the current, or the voltage value of the clock signal fluctuates due to a slight change in the electrical characteristics of the burn-in board 1 or the like, the burn-in itself is frequently interrupted. As a result, the efficiency is significantly reduced.

The function check of the burn-in board 1 itself is generally performed by a device called a board checker. However, performing such a check every burn-in is a heavy burden, and therefore, it is usually performed by a regular inspection. It was done. Therefore, even if a defect occurs in the burn-in board 1 between regular inspections, it cannot be detected.

That is, in the above-mentioned conventional configuration, even if a defect occurs in the IC chip during burn-in, burn-in
Since the defect cannot be detected in the state where the IC chip is mounted on the board, whether the cause of the defect is the IC chip itself, the incorrect insertion of the IC chip, the burn-in board 1, or the burn-in board 1. It was difficult to identify if it was in the device. That is, when a defect occurs in the IC chip, it is necessary to check the function of the burn-in board on which the IC chip is mounted in order to identify whether the cause of the defect is the burn-in board. To find out which burn-in board among the many burn-in boards that were simultaneously mounted in the burn-in device, the IC chip in which the
The troublesome work of identifying the IC for each burn-in board must be performed. If this work is not performed, the function check of all burn-in boards used after the IC chip is confirmed to be defective. Because it must be. In particular, the cause of defective IC chips is I
When the C chip is erroneously inserted, it is very difficult to know the cause after removing the IC chip from the burn-in board.

Although it is conceivable that the burn-in device itself has a function such as a board checker, the structure of the device becomes complicated, and it is not necessary to check the board every burn-in even in the same device. Even if there is, it will take a long time, which will lead to an increase in cost, etc., so this is not a practical solution. The present invention has been made by paying attention to such unsolved problems in the conventional technique, and enables checking of defects in a burn-in board with an IC chip mounted thereon without imposing an excessive burden. By doing so, it is an object of the present invention to provide a burn-in device capable of easily performing defect analysis.

[0008]

In order to achieve the above object, a burn-in device according to the present invention has an electric resistance between predetermined terminals of a burn-in board mounted with an IC chip and mounted on the burn-in device. A resistance measuring unit is provided that can measure with the burn-in board installed.

[0009]

When the resistance measuring means measures the electric resistance between the predetermined terminals of the burn-in board with the IC chip mounted, the burn-in board and the IC mounted on the burn-in board are measured.
The electrical resistance of the entire chip will be measured. Since the electric resistance value between the predetermined terminals should be within the predetermined range in the normal case, when it is out of the predetermined range, it is mounted on the burn-in board or this. It can be determined that a defect has occurred in the IC chip.

Therefore, after the burn-in is completed, if only the burn-in board and the IC chip mounted on the burn-in board determined to be abnormal from the measurement result of the resistance measuring means are inspected, the defective IC chip is generated. And whether the cause is in the IC chip, in the burn-in board, or in the burn-in device.

Since the defect of the burn-in board and the IC chip mounted on the burn-in board is detected based on the electric resistance between the predetermined terminals of the burn-in board with the IC chip mounted, the defect can be detected. Therefore, it does not require a long time like a board checker, and defects can be detected before, during, and after burn-in.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing one embodiment of the present invention, showing a part of the structure of a burn-in device, and a circuit diagram of a part for supplying a power supply V _DD and a clock signal CLK to one burn-in board 1. . The same components as those of the conventional configuration are designated by the same reference numerals, and the duplicated description will be omitted.

That is, in this embodiment, the burn-in
An ammeter 5 was interposed between the terminal a of the board 1 and the fuse 3, and an ammeter 6 was interposed between the terminal b of the burn-in board 1 and the driver 2. Therefore, the electric resistance between the terminal a connected to the power supply V _DD and the terminal c connected to the ground can be known from the display value of the ammeter 5 and the voltage value of the power supply V _DD . The electrical resistance between the terminals b and c connected to the driver 2 is measured by the voltmeter 4 and the ammeter 6.
It can be known from the displayed value of.

The electric resistance between the terminals a and c and the electric resistance between the terminals b and c must be defective in the burn-in board 1 and the IC chip mounted on the burn-in board 1. For example, since it should fall within a predetermined range, it is possible to detect that a defect has occurred in the burn-in board 1 or the IC chip mounted on the burn-in board 1 by monitoring the electric resistances.

In addition, such a defect can be detected before starting burn-in, during burn-in, and after burn-in. Therefore, if the burn-in is performed before the burn-in is performed, it is possible to easily find, for example, a defective IC chip mixed in, an IC chip erroneously inserted, or a burn-in board that has already failed. Also, by performing burn-in during or after burn-in, it is possible to find out which burn-in board among the many burn-in boards has failed during burn-in. Since it is possible to know where in the burn-in device the device was mounted, it is possible to quickly and easily detect an abnormality in the burn-in board or an abnormality in the burn-in device.

Then, the burn-in
When the board is specified, first, it is possible to easily specify whether the failure is in the IC chip, the burn-in board, or the burn-in device. For example, when the failure occurs in the IC chip. Even if
It is possible to easily identify whether the cause is the IC chip itself or the burn-in board.

Further, the structure of this embodiment does not require a particularly large design change as compared with the conventional structure, and does not cause a large complication or an increase in size of the apparatus.
The conventional problems can be solved at a realistic level. Incidentally, regarding the point that the burn-in board 1 is dealt with by the disconnection of the fuse 3 when an excessive current flows, and whether the normal voltage is applied to the terminal b is confirmed by the displayed value of the voltmeter 4. It is the same as the conventional one.

Here, in this embodiment, the ammeters 5 and 6 and the voltmeter 4 constitute resistance measuring means. In addition,
In the above embodiment, the electrical resistance between the terminals a and c and the electrical resistance between the terminals b and c are measured, but either one may be measured depending on the case.

In the above embodiment, the resistance value is measured by measuring the current with respect to the applied voltage. However, if the burn-in device supplies a predetermined current, a voltmeter is provided to measure the resistance value. It should be possible. Further, although not particularly shown, the measured values of the ammeters 5 and 6 and the voltmeter 4 are supplied to a microcomputer or the like, predetermined calculation processing is executed to calculate a resistance value, and the calculation result is displayed on a CRT or the like. Alternatively, the alarm lamp may be blinked when a large change in resistance value occurs.

[0020]

As described above, according to the present invention,
Since the electrical resistance between the specified terminals of the burn-in board can be measured while the burn-in board is mounted on the burn-in device, the burn-in can be performed before the start of burn-in without significantly complicating or increasing the size of the device. Since it is possible to detect defects both during and after execution, it is possible to easily find out, for example, mixing of defective IC chips, erroneous insertion of IC chips, or burn-in boards that have already failed. , Burn-in board abnormality and burn-in equipment abnormality can be detected early and easily, and it is easy to identify whether the defect is in the IC chip, in the burn-in board, or in the burn-in equipment. Even if there is a defect in the IC chip, it may be possible that the IC chip itself has a cause or burns. Of specific is there due to down board also has various effects that easily.

[Brief description of drawings]

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

FIG. 2 is a circuit diagram showing a conventional configuration.

[Explanation of symbols]

 1 Burn-in board 2 Driver 3 Fuse 4 Voltmeter 5, 6 Ammeter

Claims (1)

[Claims] 1. A resistance measuring means for measuring the electric resistance between predetermined terminals of a burn-in board mounted on a burn-in device with an IC chip mounted thereon is provided. And burn-in equipment.