JP2006071585A - Burn-in test board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein a required power source voltage is not able to be supplied to an inspected semiconductor integrated circuit, when a burn-in board gets large, not to allow a proper burn-in test. <P>SOLUTION: This burn-in test board of the present invention comprising: an LC socket with a plurality of the inspected semiconductor integrated circuits mounted thereon; and a multilayer printed wiring board with an electronic component mounted thereon, has a voltage conversion part supplied with a voltage higher than the required power source voltage of the inspected semiconductor integrated circuit to be converted into the required power source voltage, and the voltage conversion part is provided in each of the inspected semiconductor integrated circuits. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a board used for a burn-in test in which a semiconductor integrated circuit is placed in a high temperature environment and a voltage or a signal is applied to remove an initial failure of the semiconductor integrated circuit or a defect in a manufacturing process, particularly at a low voltage. The present invention relates to a burn-in test board used for a burn-in test of a semiconductor product.

In the semiconductor integrated circuit, the initial failure occurs with a very high probability like other products.
Therefore, the burn-in test of a semiconductor integrated circuit is a test method that attempts to remove this initial failure, particularly.
In general, initial failure and initial failure of a semiconductor integrated circuit occur at a rate of 0.1% to 5%, and occur at a room temperature of about 25 ° C. from the first few hours to about 1000 hours in a normal operation state. It has been found.

The initial failure is caused by a design or manufacturing defect. Some failures occur in about 100 hours, while others do not fail until about 1000 hours, which is ten times as long. Therefore, it is necessary to remove those that cause initial failure in the shipping test. However, even if the shipping test is performed by operating the semiconductor integrated circuit for a short time of about 1 hour in an environment that assumes the usage state, all the products pass. In addition, it is not economical to continue the shipping test for about 1000 hours when the initial failure is likely to occur, not only for the production of semiconductor integrated circuits. , It will have a major impact on the production of the final product.

Thus, it has been devised that the failure can be accelerated by raising the operating temperature of the semiconductor integrated circuit to a higher temperature than normal temperature. For example, a 1000 hour test at 50 ° C corresponds to an approximately 30 hour test at 125 ° C. A burn-in test was devised to accelerate the failure test based on this concept, perform the test as efficiently as possible, and remove the semiconductor integrated circuit causing the initial failure before use.

The burn-in apparatus performs the burn-in test.
FIG. 4 schematically shows a burn-in apparatus, and the burn-in apparatus will be described with reference to this figure.

A burn-in apparatus 100 shown in FIG. 4 includes a burn-in chamber 101 and a pattern generator 121 that generates an inspection signal to be input to a semiconductor integrated circuit. Although not shown, a power supply unit that applies a required voltage to the semiconductor integrated circuit is also provided.

In the burn-in chamber 101, a plurality of burn-in test boards 102 are connected to and held by connectors 103, respectively. Here, two burn-in test boards 102 are shown, but a plurality of burn-in test boards are accommodated between the burn-in test boards 102 at intervals in the vertical direction. On each burn-in test board 102, a large number of semiconductor integrated circuits 104 are mounted so that test signals and power supply voltages can be input.

Outside the burn-in chamber 101, a driver board 123 corresponding to the burn-in test board 102 is connected to and held by the outer part of the connector 103 between the signal line 122 connected to the pattern generator 121 and the burn-in test board 102. ing. At the same time, a power line from a power supply unit (not shown) is also connected via the driver board 123.

On the driver board 123, a driver for driving an inspection signal from the pattern generator 121 and each semiconductor integrated circuit 1 on the burn-in test board 102.
A plurality of active elements 124 such as a comparator for comparing the expected value signal for 04 and its output signal and outputting the comparison result to the pattern generator 121 are mounted.

By using such a burn-in apparatus, the semiconductor integrated circuit is subjected to a burn-in test to avoid shipping a semiconductor integrated circuit that may cause an initial failure to the market.
By the way, recent electronic devices, such as mobile devices represented by mobile phones, notebook computers, digital movies, and the like, have been reduced in size, reduced in power consumption, and reduced in weight while improving functions and performance. For this reason, semiconductor integrated circuits used in these electronic devices are also being manufactured that operate at a lower voltage than conventional semiconductor integrated circuits. For example, the conventional operation with a power supply voltage of about 6V is 3
. Only 3V or 1.8V voltage is required.

Therefore, it is necessary to make the burn-in device compatible with a low-voltage semiconductor integrated circuit. As far as the applicant of the present application knows, the burn-in device corresponding to the low-voltage semiconductor integrated circuit adjusts the voltage to be applied to the voltage required by the semiconductor integrated circuit, and in particular, the power supply voltage of the semiconductor integrated circuit is low. However, the burn-in device is not devised just because it is made into a new one.

On the other hand, in order to carry out complicated semiconductor integrated circuits and perform burn-in tests on a large number of semiconductor integrated circuits at a time, the number of burn-in test boards is increasing and the substrate size is increasing.
Under such circumstances, a burn-in test of a semiconductor integrated circuit has been carried out using a conventional burn-in apparatus and using a conventional burn-in test board having a larger size.

FIG. 3 shows a schematic diagram of such a conventional burn-in test board.
In FIG. 3, 20 is a burn-in test board, 21 is a connector section for inputting / outputting a power source and test signals necessary for the burn-in test, and 22 is a semiconductor integrated circuit mounting section to be inspected mounted on the burn-in test board. The burn test board 20 and the semiconductor integrated circuit mounting portion 22 in FIG. 3 correspond to the burn-in test board 102 and each semiconductor integrated circuit 104 in FIG. 4, respectively. Moreover, the connector part 21 of FIG. 3 is corresponded to the connector part which does not attach | subject the code | symbol of FIG.

The burn-in test board 20 includes a burn-in chamber 101 as shown in FIG.
And is mated with the connector 103. A test signal and power supply voltage from the pattern generator 121 and a power supply unit (not shown) are applied to the burn-in test board 20 via the connector 103.

As described above, the burn-in test of a semiconductor integrated circuit is performed using a conventional burn-in apparatus and a larger conventional burn-in test board. This was achieved by reducing the voltage supplied to the burn-in test board to the required low voltage.
However, as the burn-in test board increases in size and the power supply voltage of the semiconductor integrated circuit decreases, the following problems arise.

I. An appropriate voltage is applied to the semiconductor integrated circuit by interrupting the predetermined voltage at the part far from the voltage supply terminal due to the voltage drop on the burn-in test board, which has existed in the past but was not a problem because the required voltage was high. The proper burn-in test cannot be performed.
B. This also existed in the past, but the crosstalk noise between the signal lines necessary for the test, which was not a problem because the required voltage was high, and the semiconductor integrated circuit cell generated during the test operation of the semiconductor integrated circuit to be tested itself. Switching noise accompanying writing / reading is superimposed on the power supply, and as the voltage drops, it becomes a level that cannot be ignored, affecting the operation of the semiconductor integrated circuit used for the burn-in test, and the worst is to destroy this semiconductor integrated circuit Sometimes.
C. The noise superimposed on the power supply in this way is also superimposed on the test signal pattern because the power supply pattern and the ground pattern are formed as a solid pattern and the signal pattern necessary for the test is formed between them. The test signal is disturbed and proper burn-in test cannot be performed.

The present invention has been made in order to solve the above-described problem. By providing a voltage conversion unit for each semiconductor integrated circuit to be inspected, it is possible to apply a required voltage even at a position far from the voltage supply terminal. An object is to provide a burn-in test board capable of performing a burn-in test.

The burn-in test board according to the present invention is a burn-in test board composed of an IC socket for mounting a plurality of semiconductor integrated circuits to be inspected and a multilayer printed wiring board on which electronic components are mounted. It is characterized by having a voltage converter that receives a high voltage and converts it to the required power supply voltage.

In addition, the voltage converter in the burn-in test board according to the present invention is provided for each semiconductor integrated circuit to be inspected.

In the burn-in test board according to the present invention, a three-terminal regulator is used for voltage conversion of the voltage conversion unit.
And the voltage conversion circuit which comprises this voltage conversion part is duplicated, It is characterized by the above-mentioned.

According to the first and second aspects of the invention, since the configuration as described in the means for solving the problem is adopted, even when the burn-in test board is enlarged, the mounting position on the burn-in test board Regardless of this, a required voltage can be applied to the semiconductor integrated circuit to be inspected.

According to the invention of claim 3, since the configuration as described in the means for solving the problem is adopted, even if noise is superimposed on the power supplied to the burn-in test board, voltage conversion is performed. This noise can be reduced at the part. In addition, the three-terminal regulator, which is a voltage conversion element, has a built-in overcurrent protection circuit, so it is possible to prevent burn-in test board burnout during an overcurrent due to failure of the semiconductor integrated circuit under test during the burn-in test. It becomes.

According to the invention according to claim 4, since the configuration as described in the means for solving the problem is adopted, even when one of the two voltage conversion circuits fails during the burn-in test, It becomes possible to continue the burn-in test.
For these reasons, a long-life and highly reliable burn-in test board can be provided.

The best mode for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a diagram schematically showing a burn-in board according to the present invention, and FIG. 2 is a schematic circuit diagram of a voltage conversion unit mounted on the burn-in test board according to the present invention.

In FIG. 1, 10 is a burn-in test board, 11 is a connector part for inputting / outputting a voltage and a test signal that are the source of the power supply voltage of the semiconductor integrated circuit to be inspected, and 12 is a semiconductor integrated device to be inspected mounted on the burn-in test board The circuit mounting unit 13 is a voltage conversion unit that receives supply of a voltage higher than the required power supply voltage of the semiconductor integrated circuit to be tested and converts it to the required power supply voltage. A corresponding voltage conversion unit 13 is assigned to one semiconductor integrated circuit mounting unit 12 to be inspected. The connector portion 11 and the semiconductor integrated circuit mounting portion 12 to be inspected are the same as the connector portion 21 and the semiconductor integrated circuit mounting portion 22 to be inspected, respectively.

As described above, FIG. 2 is a schematic circuit diagram of the voltage conversion unit used in the present invention.
In order to improve the reliability of the burn-in test, the voltage conversion circuit is duplicated. This voltage conversion unit has a function of converting to a required voltage when a voltage higher than the required voltage of the semiconductor integrated circuit to be inspected is supplied, and its configuration is as follows.

In FIG. 2, Q1 is a three-terminal regulator that is a voltage conversion element that receives a voltage higher than the output voltage and converts it to a predetermined voltage, C1 to C3 are capacitors that prevent noise and oscillation in the voltage conversion process, and R1 and R2 Is a resistor for adjusting variation to obtain a predetermined voltage, D1 is a protection diode, and D2 is a backflow prevention diode when doubled. These constitute a single voltage conversion circuit.

On the other hand, a three-terminal regulator Q2, noise and oscillation prevention capacitors C4 to C
6, output voltage variation adjusting resistors R3 and R4, protective diode D3,
The other current system voltage conversion circuit is formed by the backflow prevention diode D4.
A voltage supply line higher than a predetermined voltage and a predetermined voltage supply line are connected to each other, and the voltage conversion circuit is duplicated. This predetermined voltage supply line is connected to the power supply terminal of the corresponding semiconductor integrated circuit to be inspected, thus the burn-in test board 10.
Although a voltage higher than a predetermined voltage is supplied to the semiconductor integrated circuit, a predetermined power can be supplied to the semiconductor integrated circuit to be inspected.

Here, the reason why the three-terminal regulator is used as the voltage conversion element is that the three-terminal regulator has the following characteristics and is easy to use.
In other words, it is an integrated circuit that can easily obtain a preset constant voltage output by supplying a predetermined voltage; it has a simple structure and can easily achieve the desired performance; the control method is linear series control Therefore, noise is not generated at the time of voltage conversion; low price, a wide variety of output voltages that can be obtained, and easy availability; built-in overheat protection and overcurrent protection circuit, so that it can be used with peace of mind. .

Next, the operation of the burn-in test board according to the present invention will be described.
The burn-in test board 10 includes a burn-in chamber 101 as shown in FIG.
And is mated with the connector 103. A test signal and a power supply voltage from the pattern generator 121 and a power supply unit (not shown) are applied to the burn-in test board 10 via the connector 103. And burn-in chamber 101
Is maintained at 125 ° C. or 150 ° C., a voltage and a test signal are supplied to the burn-in test board 10 to execute a burn-in test.

Here, taking as an example a case where a semiconductor integrated circuit to be inspected having a required power supply voltage of 1.8 V is subjected to a burn-in test, a voltage higher than the required voltage is set to a burn-in test board by the voltage conversion operation as a feature of the present invention. It will be explained that a required voltage is supplied to the semiconductor integrated circuit to be inspected even if it is input to the circuit.
Since the voltage conversion unit 13 is configured by duplicating the voltage conversion circuit as described above, each operation is the same, and therefore one voltage conversion operation will be described.
Here, as the three-terminal regulator, one that can obtain an output voltage of 1.8 V by inputting a voltage in the range of 3 V to 5.5 V is used.

It is assumed that 5 V, which is higher than a required power supply voltage, is supplied from a power supply unit (not shown). Here, the reason why the voltage is set to 5 V is that if it is lower than this, if the potential difference before and after voltage conversion is too small, the stability of the constant voltage output of the three-terminal regulator, which is a voltage conversion element, deteriorates. If it is higher than this, the difference between the input voltage and the output voltage of the three-terminal regulator becomes large, and heat is generated according to this difference, so that this heat generation is made as small as possible. Although heat generation can be released from the three-terminal regulator by means of the heat dissipation fin, a large heat dissipation fin is required depending on the amount of heat generation, which is not only disadvantageous in mounting, but also 3
This is because the life of the terminal regulator is reduced, and eventually the life of the burn-in test board is reduced.
In particular, a low dropout three-terminal regulator has recently become available, and the difference between the input voltage and the output voltage can be further reduced, so that the heat generation of the three-terminal regulator can be further reduced.

The input terminal of the supplied 5V voltage 3-terminal regulator Q1 and the capacitor C
1 connected to one. The other side of the capacitor C1 is connected to the ground, and the capacitor C1 removes noise superimposed on the 5V power line and prevents oscillation. Since the ADJ terminal of the three-terminal regulator Q1 is connected to the ground via the resistor R1, when a predetermined voltage is input, a required voltage of 1.8V is output from the output terminal. At this time, the resistors R1 and R2 connected in series between the output terminal of the three-terminal regulator Q1 and the ground adjust the variation of the output voltage so that a voltage of 1.8V is output.

The capacitor C2 inserted between the connection point of the resistors R1 and R2 and the ground
Plays a role in removing noise and preventing oscillation. The diode D1 whose cathode side is connected to the output terminal of the three-terminal regulator Q1 and whose anode side is connected to the connection point between the resistors R1 and R2 serves to protect the voltage conversion circuit. Further, a capacitor C3 is connected between the output terminal of the three-terminal regulator Q1 and the ground, and this capacitor C3 removes noise superimposed on the power supply of the output voltage 1.8V and prevents oscillation of the voltage conversion circuit. . Thus, the required 1.8 V voltage with less noise is output from the 5 V supply voltage.

Since the voltage conversion circuit as described above is duplicated, each power supply output must be connected, but if it is connected as it is, if there is any potential difference in each voltage conversion circuit, the voltage conversion with the higher potential will be performed The defect is that the output of the circuit flows into the output terminal of the lower voltage conversion circuit and cannot function as a dual power supply. Therefore, as is well known, a diode for preventing backflow is connected between the output terminals of the respective voltage conversion circuits, the output terminals of the diodes are connected, and the required output voltage is obtained therefrom. That is, the three-terminal regulators Q1 and Q2
Are connected to the anode sides of the diodes D2 and D4, respectively, and the cathode sides of the two diodes D2 and D4 are connected to output a required voltage to be supplied to a predetermined semiconductor integrated circuit mounting portion.
In this way, a required power supply voltage of the semiconductor integrated circuit to be inspected can be obtained.

As described above, one voltage conversion unit 13 is provided in one semiconductor integrated circuit mounting unit 12 to be tested, and a required power supply voltage is generated for each voltage conversion unit 13.
For this reason, 5 V, which is the voltage supplied to the terminal of the connector part 11 of the burn-in test board 10, is supplied to the vicinity of each semiconductor integrated circuit mounting part 12 to be inspected. Therefore, the voltage supplied to the voltage conversion unit 12 corresponding to the semiconductor integrated circuit mounting unit 12 to be inspected far from the connector unit 11 has a constant voltage drop as usual and drops to a voltage of about 4.7V. To do.
However, as described above, the three-terminal regulators Q1 and Q2 used in the voltage conversion circuit 12 output a stable voltage of 1.8V under an input voltage of 3V to 5.5V. Even if the voltage supplied to the section 13 drops to about 4.7 V, the required voltage of 1.8 V is supplied to the semiconductor integrated circuit mounted on the semiconductor integrated circuit mounting section 12 to be inspected. . And since the control system which is the feature of the three-terminal regulator is linear series control, no noise is generated during voltage conversion.

It is a figure which shows typically the burn-in board which becomes this invention. Outline of voltage converter mounted on burn-in test board according to the present invention It is the figure which showed the conventional burn-in test board typically. It is the figure which showed the burn-in apparatus typically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Burn-in test board 11 Connector part 12 Tested semiconductor integrated circuit mounting part 13 Voltage conversion part

Claims (4)

In a burn-in test board consisting of an IC socket for mounting a plurality of semiconductor integrated circuits to be inspected and a multilayer printed wiring board for mounting electronic components,
A burn-in test board, comprising: a voltage conversion unit which receives a voltage higher than a required power supply voltage of the semiconductor integrated circuit to be inspected and converts it to the required power supply voltage. 2. The burn-in test board according to claim 1, wherein the voltage converter is provided for each semiconductor integrated circuit to be inspected. 3. The burn-in test board according to claim 1, wherein a three-terminal regulator is used for voltage conversion of the voltage converter. The burn-in test board according to claim 1 or 2, wherein the voltage conversion unit has a required voltage conversion circuit duplexed.

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