JPH10135286A - Method and system for sorting high temperature detect product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high temperature detect product sorting system for improving the failure rate and enhancing the quality by performing a test similar to a high temperature test without increasing the production cost through introduction of an additional equipment or increase of the measuring time thereby sorting a detect product under high temperature. SOLUTION: Diodes 11, 12 for electrostatic breakdown protection are connected in a reverse bias direction between an I/O terminal 5 and a power supply terminal 2 or a ground terminal 3. An external power supply 4 for test is connected in forward bias direction with the diode 12 at the I/O terminal 5 which is not used in a test required for high temperature measurement. A power supply voltage for elevating the bonding temperature of a semiconductor circuit 1 with the product of power consumption of the diode 12 and thermal resistance of a package is fed from the external power supply 4 to the diode 12 by turning a switch 6 on.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-temperature defect selection apparatus and a high-temperature defect selection method, and more particularly to a test for guaranteeing high-temperature operation and electrical characteristics of a semiconductor circuit product.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor circuit product, operation and electrical characteristics are usually guaranteed in a certain temperature range. However, when a semiconductor circuit product is tested, the operation and electrical characteristics are usually tested at room temperature. That is, the temperature characteristics are evaluated in advance, and the characteristics are compensated by providing a margin for the temperature fluctuation.

[0003] Such a compensation method does not anticipate what kind of defective product will occur, but merely considers the temperature characteristics of a normal product. However, in a defective product, when some transistors are not operating normally, there is no guarantee that the temperature characteristics of the defective product and the good product are the same. Therefore, if the defective product has a temperature characteristic that is significantly different from that of a good product, it is highly likely that the defective product cannot be sorted out.

[0004] Therefore, in the case of a product which requires a very low rejection rate, it is practiced that the rejected product and the non-defective product are actually placed in a high temperature state. In order to perform the test at a high temperature, it is necessary to measure only the product at a high temperature without changing the temperature of the measuring device (tester) around the product, and to maintain the product at a constant temperature beforehand. It is necessary to prepare test equipment.

Since the measurement time is increased by introducing such a special device or performing a high-temperature test, the production cost of the product becomes extremely high. Under these circumstances, except for products that require a very low reject rate (such as those that are deeply involved in safety), the current situation is that high-quality defective products and non-defective products are not actually sorted out. It is.

In order to perform a test without using such a high-temperature test apparatus, the power supply voltage of the semiconductor circuit to be tested is set to be higher than the operation guarantee range, thereby reducing the power consumption of the semiconductor circuit itself and the package. The measurement is also performed by increasing the temperature by the product of the thermal resistance.

However, in this method, in terms of circuit operation,
This method is applicable because it is impossible to set the voltage unconditionally, it is not possible to raise the power supply voltage beyond the withstand voltage, and it is not possible to raise the temperature sufficiently if the power consumption of the circuit is small. There are restrictions on the products that can be made.

Further, it is also possible to provide an element which generates heat as a test circuit in a semiconductor circuit, and perform a test by increasing a junction temperature of the semiconductor circuit. As this method, there is a technique described in JP-A-63-010537. In the case of this technology, the element that generates heat is not particularly limited, but as shown in FIG. 5, an example is disclosed in which a semiconductor circuit 20 is provided with a test terminal 23 and a resistor 24 and the resistor 24 is used as a heating element. . Incidentally, in FIG.
Is a power supply terminal, and 22 is a ground terminal. Similarly to this technology, an example using a resistor is disclosed in Japanese Patent Application Laid-Open No. 63-006856.
There is also a technique disclosed in Japanese Unexamined Patent Publication (Kokai) No. H11-26095.

Further, examples using a diode as a heating element and MOS (Metal Oxide Semico)
There is also an example using a transistor. For an example using a diode, see JP-A-04-174532.
An example using a MOS transistor is disclosed in Japanese Patent Application Laid-Open No. 04-074451.

That is, in the example using a diode, as shown in FIG. 6, a semiconductor circuit 30 is provided with a test terminal 33 and a diode 34, and the diode 34 is used as a heating element. In FIG. 6, reference numeral 31 denotes a power terminal, 3
2 is a ground terminal.

In all of the above methods, a dedicated heating element and a test terminal are provided. Therefore, when the number of the heating elements and the test terminals is increased, the chip size increases and the manufacturing cost increases.

[0012]

In the above-described high-temperature test for a conventional semiconductor circuit, a defective product having a temperature characteristic remarkably different from that of a non-defective product cannot be discriminated by a test at room temperature. Defective products cannot be sorted out.

When a high-temperature test is performed on a semiconductor circuit using a high-temperature test device, a high-temperature test device must be introduced to perform the high-temperature test, and the measurement time increases, thereby increasing the manufacturing cost of the product. Becomes large.

Further, it is possible to provide an element that generates heat as a test circuit in the semiconductor circuit and perform the test by increasing the junction temperature. However, in this method, the number of heat generating elements and test terminals must be increased. Therefore, the chip size increases and the manufacturing cost increases.

Therefore, an object of the present invention is to solve the above-mentioned problems and to carry out a test similar to that performed at a high temperature without increasing the production cost of a product by introducing an apparatus and increasing the measurement time. It is an object of the present invention to provide a high-temperature defect selection device and a high-temperature defect selection method capable of selecting defects at a high temperature and improving a defect rate and quality.

[0016]

SUMMARY OF THE INVENTION A high-temperature defect sorting apparatus according to the present invention is a high-temperature defect sorting apparatus for a semiconductor circuit including a diode for electrostatic breakdown protection, and is not used in a test that needs to be measured at a high temperature. An external test power supply connected in a forward bias direction to the diode connected to the input / output terminal and supplying a power supply voltage value such that a junction temperature of the semiconductor circuit becomes an ambient temperature necessary for the test; A switch element for connecting the external power supply for testing and the diode when performing a test.

The method for selecting high-temperature defects according to the present invention is a method for selecting high-temperature defects in a semiconductor circuit including a diode for protection against electrostatic damage, which is connected to an input / output terminal that is not used in a test that needs to be measured at high temperatures. A first step of connecting a test external power supply to the diode in a forward bias direction, and a power supply voltage from the test external power supply such that a junction temperature of the semiconductor circuit becomes an ambient temperature required for the test. Supplying a value to said diode.

That is, in the high-temperature defect selection method of the present invention, in a test for compensating for the operation and electrical characteristics of a circuit which needs to be measured at a high temperature, an input / output terminal and a power supply terminal or a ground terminal are connected. Of the diodes for ESD protection connected in the reverse bias direction during the test, the diode connected to the input / output terminal that is not used during the test that needs to be measured at high temperature. The power supply voltage value is set for the power supply so that the junction temperature of the semiconductor circuit matches the temperature rise value required for the test by the temperature rise due to the product of the power consumption of the diode and the thermal resistance of the package. ing.

In this way, by making the temperature rise value coincide with the junction temperature at the time of measuring the high temperature, the same condition as when the ambient temperature is increased is performed, and a test that needs to be measured at the high temperature is performed. can do. Therefore, it is possible to perform the same tests as those performed at high temperature without increasing the manufacturing cost of products due to the introduction of equipment and increased measurement time, and it is possible to sort out defects at high temperature and improve the defect rate. And quality can be improved.

[0020]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing one embodiment of the present invention. In the figure, 1 is a semiconductor circuit, 2 is a power supply terminal, 3 is a ground terminal, 4 is an external test power supply, 5 is an input / output terminal, and 6 is a switch.

In the semiconductor circuit 1, diodes 11 and 12 are provided for protection against electrostatic breakdown. These diodes 11 and 12 are connected in the reverse bias direction between the input / output terminal 5 and the power supply terminal 2 or the ground terminal 3.

Here, the input / output terminal 5 is an input / output terminal that is not used in a test that needs to be performed at a high temperature. An external test power supply 4 is connected to the input / output terminal 5 via a switch 6, and the test external power supply 4 is connected to the diode 12 in a forward bias direction. Therefore, when the switch 6 is turned on, the power supply voltage value from the test external power supply 4 is supplied to the diode 12.

Therefore, in the method for selecting a high-temperature defect according to one embodiment of the present invention, the diodes 11 and
After the test external power supply 4 is connected in the forward bias direction to the diode 12 connected to the input / output terminal 5 which is not used in the test which needs to be measured at a high temperature, the junction temperature of the semiconductor circuit 1 becomes high. This is performed by supplying a power supply voltage value from the external power supply for test 4 to the diode 12 so that the ambient temperature required for the test that needs to be measured in the step (1) is obtained.

FIG. 2 is a flowchart showing a test operation according to one embodiment of the present invention. A test method according to an embodiment of the present invention will be described with reference to FIGS.

First, at the first stage, the switch 6 is turned off, and a test performed at room temperature is performed with the test external power supply 4 not connected to the diode 12 (step S1 in FIG. 2). (Step S2 in FIG. 2).

At the next stage, when performing a test performed at a high temperature, after setting the voltage value of the test external power supply 4 (step S3 in FIG. 2), the switch 6 is turned on to turn on the input not used during the test. The test external power supply 4 is connected between the output terminal 5 and the ground terminal 3 in the forward bias direction with respect to the ESD protection diode 12 (step S4 in FIG. 2).
As a result, the temperature of the semiconductor circuit 1 becomes necessary for the test, so that the test performed at a high temperature is performed (Step S5 in FIG. 2).

At this time, the voltage value of the test external power supply 4 is Pd where the power consumption of the diode 12 is Pd.
The power consumption of itself is Pic, the thermal resistance of a package (not shown) of the semiconductor circuit 1 is Rj-a, and the ambient temperature is Tj.
Assuming that a is a and the junction temperature is Tj, the junction temperature Tj is obtained from the equation: Tj = Ta + (Pd + Pic) * (Rj-a).

When it is desired to raise the ambient temperature from room temperature (25 ° C.) by Tup, assuming that the junction temperature when the ambient temperature is increased is Tj2, Tj2 = Ta + Tup + Pic * (Rj-a).

In order to make the junction temperature at the time of the normal temperature test coincide with the junction temperature at the time of the high ambient temperature, it is only necessary that Tj2 and Tj are equal. Tj2−Tj = Tup−Pd * (Rj−a) = 0, and Pd = Tup / (Rj-a) is obtained based on this equation. That is, the power consumption of the diode 12 may be set based on the required temperature rise and the thermal resistance of the package.

For example, if the package has a thermal resistance of 100 ° C./W at a temperature rise of 50 ° C., the power consumption of the diode 12 may be 200 mW. This diode 12
250 mA when the forward bias voltage VF is 0.8 V
If it flows, the voltage value of the test external power supply is 0.8 V
May be set in advance.

However, in this case, since the temperature characteristics and the variation of the forward bias voltage VF of the diode 12 are not taken into consideration, if it is desired to set the temperature a little more precisely, the current is reduced to such a level that the temperature does not rise during measurement at room temperature. The forward bias voltage VF of the diode 12 is measured in advance, and a test program for calculating the voltage value of the test external power supply 4 by adding a current increase and a temperature characteristic from the value is easily obtained. It is possible.

The value of the thermal resistance of the package differs depending on the state of the board and the usage of the socket. However, similarly, when the power consumption is 0 and when the voltage is applied to the power supply terminal 2, the temperature of the package changes. By measuring the forward bias voltage VF of the diode 12 at a current that does not increase, it can be obtained by using the temperature characteristics of the diode 12, and this can be calculated before conducting the test. If this is the case, the temperature can be set with higher accuracy.

As described above, by applying the embodiment of the present invention, by setting the voltage value of the test external power supply 4, a test can be performed in the same manner as when the ambient temperature is raised.

FIG. 3 is a block diagram showing another embodiment of the present invention. Referring to the figure, an external power supply 7 for testing is connected via a switch 8 between an input / output terminal 5 and a power supply terminal 2 which are not used in a test which needs to be performed at a high temperature in another embodiment of the present invention. An external power supply 4 is connected to the diode 11 in a forward bias direction. Therefore, when the switch 8 is turned on, the power supply voltage value from the test external power supply 7 is supplied to the diode 11.

Therefore, in the method for selecting a high-temperature defect according to another embodiment of the present invention, the diode 1 for protecting against electrostatic breakdown is provided.
Diode 1 connected to input / output terminal 5 which is not used in a test which needs to be measured at high temperature among 1, 12
After the test external power supply 7 is connected to the semiconductor device 1 in the forward bias direction, the junction temperature of the semiconductor circuit 1 is changed from the test external power supply 7 to the ambient temperature necessary for the test that needs to be measured at a high temperature. This is performed by supplying the power supply voltage value to the diode 11.

In this case, the test external power supply 4 is a negative power supply in one embodiment of the present invention, but the test external power supply 7 is a positive power supply in another embodiment of the present invention, so that the negative power supply cannot be used. It is also effective in cases.

FIG. 4 is a block diagram showing another embodiment of the present invention. In the drawing, another embodiment of the present invention is a combination of one embodiment of the present invention and another embodiment, and the operation is the same as that of one embodiment of the present invention and other embodiments. In another embodiment of the present invention, diodes 11 and 1 for electrostatic breakdown protection are provided.
By generating heat for both of them, it is possible to cope with a case where a larger heat generation amount is required.

As described above, the test external power supplies 4 and 7 for supplying a power supply voltage value so that the junction temperature of the semiconductor circuit 1 becomes the ambient temperature required for the test are used. , 7 and the switching elements 6, 8 for connecting the diodes 11, 12 connected to the input / output terminal 5, which are not used in the test which needs to be measured at a high temperature, in the forward bias direction with respect to the diodes 11, 12. By performing the connection, the same tests as those performed at high temperatures are performed without increasing the manufacturing cost of products due to the introduction of equipment for performing high temperature tests and increasing the measurement time, and without increasing the number of test terminals. This makes it possible to sort out defects at high temperatures, thereby improving the defect rate and improving the quality.

Therefore, it is possible to select a defective product which cannot be selected only by screening at normal temperature without any problem in realization, thereby preventing outflow of the defective product and improving the quality.

The present invention can take the following aspects in connection with the description of the claims.

(1) An apparatus for selecting a high-temperature failure of a semiconductor circuit including a diode for protection against electrostatic damage connected in a reverse bias direction between an input / output terminal and one of a power supply terminal and a ground terminal, The semiconductor is connected in a forward bias direction to the diode connected to an input / output terminal which is not used in a test which needs to be measured at a high temperature in a test for compensating operation and electrical characteristics of a semiconductor circuit, and A test external power supply that supplies a power supply voltage value such that the junction temperature of the circuit becomes the ambient temperature required for the test, and a switch element that connects the test external power supply and the diode when performing the test. A high-temperature defect sorting device, comprising:

(2) The power supply voltage value to the test external power supply needs to be measured at the ambient temperature and the normal temperature required for the product of the power consumption of the diode and the thermal resistance of the package of the semiconductor circuit. (1) characterized in that the temperature rise between the ambient temperature required in the test with the temperature
The high-temperature defect sorting device as described.

(3) A method for selecting a high-temperature failure of a semiconductor circuit including a diode for protection against electrostatic damage connected in a reverse bias direction between an input / output terminal and one of a power supply terminal and a ground terminal, In the test for compensating the operation and electrical characteristics of the semiconductor circuit, an external power supply for test is applied in a forward bias direction to the diode connected to the input / output terminal which is not used in the test which needs to be measured at a high temperature. A first step of connecting, and a second step of supplying a power supply voltage value from the test external power supply to the diode such that a junction temperature of the semiconductor circuit becomes an ambient temperature necessary for the test. High-temperature defect sorting method characterized by the following.

(4) The power supply voltage value to the test external power supply needs to be measured at the ambient temperature and the normal temperature required for the product of the power consumption of the diode and the thermal resistance of the package of the semiconductor circuit. (3) characterized in that the temperature rise between the required ambient temperature in a test with a certain temperature
High-temperature defect sorting method described.

[0045]

As described above, according to the high-temperature defect sorting apparatus of the present invention, a power supply voltage value is supplied such that the junction temperature of a semiconductor circuit becomes an ambient temperature necessary for a test that needs to be measured at a high temperature. A switch element for connecting a test external power supply to be tested and a diode connected to an input / output terminal not used in the test when performing the test, and connecting the diode in a forward bias direction to the diode. As a result, the same tests as those performed at high temperatures can be performed without increasing the manufacturing costs of products due to the introduction of equipment and an increase in measurement time. There is an effect that improvement and quality improvement can be achieved.

According to the high-temperature defect selection method of the present invention, a test external power supply is connected in a forward bias direction to a diode connected to an input / output terminal that is not used in a test that needs to be measured at a high temperature. Supplying a power supply voltage value from an external test power supply to the diode so that the junction temperature of the semiconductor circuit becomes the ambient temperature required for the test, the introduction of equipment and an increase in measurement time increase the production cost of the product. A test similar to that performed at a high temperature can be performed without performing the test, and there is an effect that it is possible to select a defect at a high temperature, thereby improving a defect rate and improving quality.

[Brief description of the drawings]

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

FIG. 2 is a flowchart illustrating a test operation according to an embodiment of the present invention.

FIG. 3 is a configuration diagram showing another embodiment of the present invention.

FIG. 4 is a configuration diagram showing another embodiment of the present invention.

FIG. 5 is a configuration diagram showing a conventional example.

FIG. 6 is a configuration diagram showing a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 semiconductor circuit 2 power supply terminal 3 ground terminal 4, 7 external power supply for test 5 input / output terminal 6, 8 switch 11, 12 diode for preventing electrostatic breakdown

Claims (4)

[Claims] An apparatus for selecting high-temperature failure of a semiconductor circuit including a diode for protection against electrostatic breakdown, comprising: a diode connected to an input / output terminal that is not used in a test that needs to be measured at a high temperature; A test external power supply that is connected in a bias direction and supplies a power supply voltage value such that a junction temperature of the semiconductor circuit becomes an ambient temperature necessary for the test; and the test external power supply and the diode when performing the test. A high-temperature defect sorting device, comprising: 2. A power supply voltage value to the test external power supply,
The product of the power consumption of the diode and the thermal resistance of the package of the semiconductor circuit is the temperature rise between the ambient temperature required for the test and the ambient temperature required for the test that needs to be measured at room temperature. 2. The high-temperature defect sorting apparatus according to claim 1, wherein: 3. A method for selecting a high-temperature failure of a semiconductor circuit including a diode for protection against electrostatic damage, comprising testing a diode connected to an input / output terminal that is not used in a test that needs to be measured at a high temperature. A first step of connecting a test external power supply in a forward bias direction, and supplying a power supply voltage value from the test external power supply to the diode such that a junction temperature of the semiconductor circuit becomes an ambient temperature necessary for the test. And a second step. 4. A power supply voltage value to the test external power supply,
The product of the power consumption of the diode and the thermal resistance of the package of the semiconductor circuit is the temperature rise between the ambient temperature required for the test and the ambient temperature required for the test that needs to be measured at room temperature. 4. The method for selecting high-temperature defects according to claim 3, wherein: