JP3173233B2 - IC inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load circuit of an IC inspection device.

[0002]

2. Description of the Related Art Normally, an IC inspection apparatus for inspecting the function of an IC measures a voltage or a current at a measurement terminal point while supplying a termination voltage to a measurement terminal of the IC to be measured via a load resistor. Inspection is carried out.

Next, FIG. 2 shows a schematic configuration of a conventional inspection apparatus. FIG. 2 shows a schematic configuration of an inspection apparatus for satisfying the measurement specifications of the output voltage and current of the IC 1 to be measured.
A termination voltage (V _T ) 31 is supplied to the measurement terminal 3 of the IC under test 1 via the load resistor 11. IC1 and load resistance 11
Are mounted on the test fixture board 41.

The measuring terminal 3 of the IC 1 to be measured is connected to a pin electronics 51 outside the fixture board 41,
Here, the measurement is performed. Here, as the values of the load resistor 11 and the termination voltage 31, values that satisfy the output voltage and current specifications of the IC 1 to be measured are selected. The actual IC and output voltage measurement conditions are, for example, those shown in Table 1 or Table 2.

[0005]

[Table 1]

[0006]

[Table 2] Under the conditions shown in Table 1, the output current I _OH is set to 5 mA when the high-level output voltage V _OH is 2.4 V, and the output current I _OL is set to 4 when the low-level output voltage V _OL is 0.4 V. .2 mA. That is, when the output of the IC 1 is at the high level, the output voltage is 2.4 V or more even when a current of 5 mA flows from the output, and when the current of 4.2 mA flows into the output at the low level, the output voltage becomes zero. .4V or less.

The value of the load resistor 11 and the value of the termination voltage 31 satisfying the above conditions are calculated to be 217 Ω, 1.
It is set to 313V. FIG. 3 is a diagram showing the relationship between the load resistor 11 and the termination voltage 31 determined in this way. When the output voltage measurement specification of another type IC shown in Table 2 is used, the relationship between the load resistor 11 and the termination voltage 31 that satisfies the specification is determined as shown in FIG.

FIG. 5 is a graph of the load condition calculation formula of the measurement specifications shown in Tables 1 and 2, wherein the intersections between the straight lines or the broken lines are the same resistance value, the same termination voltage, and both the high level and the low level. This is the point that satisfies the condition of Point A in the figure indicates a point satisfying the standard of Table 1, and point B indicates a point satisfying the standard of Table 2.

As described above, when the measurement specifications are different depending on the type of IC, it is necessary to change the values of the load resistor 11 and the termination voltage 31 each time. Although the termination voltage 31 can be easily changed by a normal program, the test fixture board 41 needs to be replaced in order to change the value of the load resistor 11.

[0010]

In the case of measuring ICs having the same pin connection but different measurement specifications due to a difference in power supply voltage, a conventional IC inspection apparatus has a test fixture board conforming to each specification as described above. It was necessary to replace it with something and measure it. That is, there is a problem that ICs having different measurement specifications cannot be measured using the same test fixture board.

[0011] To solve this problem, the present invention provides:
It is an object of the present invention to provide an IC inspection apparatus capable of changing a termination voltage by a program even when measurement specifications are different and performing measurement by sharing the same test fixture board.

[0012]

In order to achieve this object, the present invention provides an IC test for measuring a measured IC 1 while supplying a termination voltage to a measuring terminal 3 of the measured IC 1 via a load resistor. In the apparatus, a series-connected resistor 1 having one end connected to the measurement terminal 3 and the other end connected to the termination voltage supply terminal 31 is provided.
1 and a diode 21, a series-connected resistor 12 having one end connected to the measurement terminal 3 and the other end connected to the termination voltage supply terminal 32.
And a diode 22.

[0013]

According to the present invention, two sets of a load resistor for determining an output current value and a diode for determining a current direction are connected in series to an output terminal of an IC to be measured, and a load circuit is shared.

One of the two sets has a high level output voltage V
_The other set is used for setting the measurement conditions of the low-level output voltage. If the measurement specifications change, only the terminal voltage value is changed by the program, and the load current value is measured under each measurement condition. Therefore, since it is not necessary to change the resistance value, it is possible to measure ICs of two types of measurement specifications with the same fixture board.

[0015]

FIG. 1 shows a schematic configuration of an IC inspection apparatus according to an embodiment of the present invention. The same parts as those of the conventional apparatus of FIG. 2 are denoted by the same reference numerals, and the detailed description thereof will be omitted. In the present invention, two sets of load resistors and diodes connected in series are prepared, and one terminal is connected to the measurement terminal 3 and the other terminal is connected to the terminal voltage supply terminals 31 and 32.

In the embodiment shown in FIG. 1, one end of the load resistor 11 is connected to the measuring terminal 3 and the other end is connected to the anode terminal of the diode 21. The cathode terminal of the diode 21 is connected to a terminal voltage supply terminal 31 (V _B1 ). Load resistance 1
One end of 2 is connected to the measurement terminal 3 and the other end is connected to the cathode of the diode 22. The anode of the diode 22 is connected to a terminal voltage (V _B2 ) supply terminal 32. When the output voltage of the IC under test 1 is high, the current under the measurement conditions flows to the terminal voltage supply terminal 31 via the load resistor 11 and the diode 21. When the output voltage is low, a current flows from the terminal voltage supply terminal 32 to the IC 1 through the diode 22 and the load resistor 12.

Next, using the apparatus shown in FIG.
FIG. 6 is a diagram for explaining the voltage-current relationship of the measured value of C.
When the output voltage of the IC under test 1 is high (V _OH ), the load current (I _OH ) flows to the load resistance (R _L1 ). Therefore, V _OH -I _OH × R _L1, and the termination voltage V _B1 is the voltage of the voltage V _T1 of the connection point of the diodes 21 and the load resistor 11 is V _T1 -V _F1
Should be given.

When the output voltage is low (V _OL ), the load current I _OL flows into the IC 1 through the load resistance R _L2 . Therefore, the voltage V _T2 at the connection point between the load resistor 12 and the diode 22 becomes V _OL + I _OL × _{RL 2} , and the termination voltage V
V _T2 + V _F2 may be given as _B2 . Note that V _F1 , V _F2
Is a forward voltage of the diodes 21 and 22, respectively.

FIG. 7 is a graph showing the relationship between the load resistance values R _L1 and R _L2 and the termination voltage values V _T1 and V _{T2 under the} measurement specifications shown in Tables 1 and 2. For example, if the load resistance is 30
When 0 Ω is selected, V _T1 = 0.9 and V _T2 = 1.66 V are obtained in order to measure an IC having the specifications in Table 1, and V _T1 = 1.8 V and V _T2 = in the specifications in Table 2. 1.0V is obtained. The terminal voltage values V _B1 and V _B2 may be added by adding or subtracting the values of the forward voltages V _F1 and V _F2 of the diode, respectively. Here the forward voltage V _F1, V _B1 = 0.2V when using the V _F2 both 0.7V Tosureba Table 1, may be programmed into V _B2 = 2.36V, the time specification of Table 2 V _B1 = 1.1 V, V _B2 = 1.
What is necessary is just to program to 7V.

Next, the configuration of another embodiment of the present invention is shown in FIG.
Shown in In this embodiment, the load resistors 11 and 12 connected to the measurement terminal 3 are connected via the relay 2. The relay 2 is normally closed during the function test, and the IC 1 to be measured and one ends of the load resistors 11 and 12 are connected. Also, at the time of DC parameter inspection, the relay 2 is opened and operates so as not to be affected by the load.

Note that the connection directions of the diodes 21 and 22 that determine the current direction used in the embodiment are usually connected so that they are opposite to each other, and the measurement conditions when the measurement terminal goes to high level and low level are I am trying to set it. In the embodiment, two sets of the load resistance and the diode are used. However, three or more sets can be prepared and set according to the measurement conditions.

[0022]

According to the present invention, a plurality of sets are prepared by connecting a load resistor and a diode in series, and a termination voltage is supplied from one end of each set. For example, the same test fixture board can be shared and used even if the load conditions of the measurement specifications are different.

[Brief description of the drawings]

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

FIG. 2 is a schematic configuration diagram of a conventional inspection apparatus.

FIG. 3 is a diagram showing load conditions that satisfy the measurement specifications in Table 1.

FIG. 4 is a diagram showing load conditions that satisfy the measurement specifications in Table 2.

FIG. 5 is a graph showing load conditions and calculation formulas of the measurement specifications in Tables 1 and 2.

FIG. 6 is a diagram illustrating a voltage-current relationship according to the embodiment of the present invention.

FIG. 7 is a graph showing load conditions and calculation formulas of the measurement specifications in Tables 1 and 2.

FIG. 8 is a diagram showing a configuration of another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IC to be measured 2 Relay 3 Measurement terminal 11 ・ 12 Load resistance 21 ・ 22 Diode 31 ・ 32 Termination voltage supply terminal 41 Test fixture board 51 pin electronics

Claims (2)

(57) [Claims] 1. An IC inspection apparatus for measuring an IC under test (1) while supplying a terminal voltage to a measurement terminal (3) of the test IC (1) via a load resistor. ), The other end is a first termination voltage supply terminal
(31) a first resistor (11) and a first diode (21) connected in series, one end of which is connected to the measurement terminal (3), and the other end of which is the second terminal voltage supply terminal.
An IC inspection device comprising a series-connected second resistor (12) and a second diode (22) connected to (32). 2. The IC inspection apparatus according to claim 1, wherein the connection directions of the first and second diodes (21) and (22) are opposite to each other.