JP5003955B2 - IC tester - Google Patents

Description

The present invention relates to an IC tester for testing a liquid crystal driver for outputting a multi-tone voltage, without providing a current measuring unit for each pin, it relates to an IC tester which attained a reduction of pin-to-pin resistance test of the liquid crystal driver .

  The liquid crystal drive driver is composed of TCP (Tape Carrier Package) (TCP is a generic name and includes COF (Chip On Film)), and as shown in FIG. 3, a TAB (Tape Automated Bonding) tape 11 and a chip 12 And the chip 12 is connected to the plurality of pins 13 via wiring (not shown). For this reason, since the pitch between the pins 13 is narrow, the current between the pins 13 is measured by an IC tester to test the resistance value between the pins. Although the resistance test between pins can be performed as in Patent Document 1 below, the number of pins of the liquid crystal drive driver is very large, and if a current measuring unit is provided for each adjacent pin, the IC tester becomes expensive. The test is performed as shown in FIG.

JP 5-190637 A

  In FIG. 4, a liquid crystal drive driver (hereinafter abbreviated as DUT) 10 is composed of TCP as shown in FIG. 3, and outputs a multi-gradation voltage from a plurality of pins. The voltage generator 20 is provided in the IC tester and applies a voltage to a plurality of pins of the DUT 10. The multiplexer 30 is connected to and switched to a plurality of pins adjacent to a pin to which a voltage is applied to the voltage generator 20. The current measuring unit 40 measures the current of the pin switched by the multiplexer 30. The control unit 50 controls the voltage generation unit 20 and the multiplexer 30 and determines the inter-pin resistance test based on the measurement result of the current measurement unit 40. The inter-pin resistance R indicates a resistance component between the pins of the DUT 10. Note that configurations for tests other than inter-pin resistance are omitted.

  The inter-pin resistance test operation of such an apparatus will be described. The voltage generator 20 outputs a voltage to a desired plurality of pins of the DUT 10 according to an instruction from the controller 50. The multiplexer 30 switches the pins of the DUT 10 adjacent to these desired pins according to an instruction from the control unit 50. The current measuring unit 40 measures the current of the pin switched by the multiplexer 30. Based on the measurement result (current value), the control unit 50 obtains the resistance value of the inter-pin resistance R and determines whether the DUT 10 is good or bad.

  In recent years, the liquid crystal display driver has increased in size and the number of pixels, so that the liquid crystal driving driver has about 700 pins, the pin-to-pin pitch is about 30 μm, and the gap between pins is narrowed to about 10 μm. As a result, a short-circuit between pins is likely to occur, so that a determination value exceeding 750 MΩ has been required for a conventional pin resistance value of about 200 MΩ. As a result, the settling time of the current flowing between the pins is changed from 10 to 100 ns to several tens of ms, and the waiting time until the measurement is started is increased. Therefore, if the test is performed after the settling is performed and the multiplexer is used for switching, the test time is required. On the other hand, if a current measuring unit is provided for each pin, there is a problem that the IC tester becomes expensive.

Accordingly, an object of the present invention is to realize an IC tester capable of shortening the resistance test between pins of a liquid crystal drive driver without providing a current measuring unit for each pin.

In order to achieve such a problem, the invention according to claim 1 of the present invention is:
In an IC tester for testing a liquid crystal drive driver that outputs a multi-gradation voltage,
A voltage generator for applying a voltage to a plurality of pins of the liquid crystal drive driver;
A voltage measuring unit that is provided for each pin that outputs a multi-gradation voltage of the liquid crystal drive driver, the input can be attenuated by an attenuator by resistance voltage division, and the voltage is measured;
The voltage generator is turned off during a grayscale voltage test, a grayscale voltage test is performed based on the voltage value measured by the voltage measurement unit, and a voltage is applied to the voltage generator during a pin-to-pin resistance test. A control unit that causes the voltage measurement unit to measure a voltage due to the resistance of the attenuator of the voltage measurement unit corresponding to the pin adjacent to the pin to which the voltage is applied, and to determine a resistance test between the pins based on the measurement result It is characterized by.
Invention of Claim 2 is invention of Claim 1, Comprising:
The voltage measuring unit is characterized in that, during the inter-pin resistance test, the two voltage dividing resistors of the attenuator are used as one resistor, the current is converted into a voltage, and the voltage is measured.
Invention of Claim 3 is invention of Claim 1 or 2, Comprising:
The voltage measurement unit
A first switch electrically connecting one end to a pin of the liquid crystal drive driver;
A second switch for electrically connecting one end to the pin of the liquid crystal drive driver;
A first resistor connecting one end to the other end of the second switch;
A second resistor for connecting one end to the other end of the first resistor and grounding the other end;
A third switch connecting one end to the other end of the first switch;
A fourth switch connecting one end to the other end of the first resistor;
An A / D conversion unit for connecting an input end to the other end of the third and fourth switches is provided .

  According to the present invention, the current of the inter-pin resistance test is converted into a voltage by the resistance of the attenuator of the voltage measurement unit, and the pins of the liquid crystal drive driver are measured at the same time. The driver pin-to-pin resistance test can be shortened.

Further, according to claim 2, using two voltage dividing resistors of the attenuator as a single resistor, since converts the current into a voltage, it can be sensitively tested low current at the voltage measuring unit.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention.

  In FIG. 1, a liquid crystal drive driver (hereinafter abbreviated as DUT) 1 is composed of TCP as shown in FIG. 3, and outputs a multi-gradation voltage from a plurality of pins. The voltage generation unit 2 applies a voltage to each of a plurality of pins of the DUT 1, that is, one skipped pin. The voltage measuring unit 3 is provided for each pin that outputs the multi-tone voltage of the DUT 1, and the input can be attenuated by an attenuator based on resistance voltage division to measure the voltage. The control unit 4 turns off the voltage generation unit 2 during the grayscale voltage test, performs a grayscale voltage test based on the voltage value measured by the voltage measurement unit 3, and gives a voltage to the voltage generation unit 2 during the inter-pin resistance test. The voltage measurement unit 3 measures the voltage by the attenuator of the voltage measurement unit 3 corresponding to the pin adjacent to the pin to which the voltage is applied by the voltage generation unit 2, and the inter-pin resistance test is determined based on the measurement result. The inter-pin resistance R indicates a resistance component between the pins of the DUT 1.

Next, a specific example of the voltage measuring unit 2 will be described with reference to FIG.
In FIG. 2, switches SW1 and SW2 are electrically connected at one end to the pins of the DUT. The resistor r1 has one end connected to the other end of the switch SW2. The resistor r2 has one end connected to the other end of the resistor r1 and the other end grounded. The resistors r1 and r2 constitute an attenuator. The switch SW3 has one end connected to the other end of the switch SW1. The switch SW4 has one end connected to the other end of the resistor r1. The A / D converter 31 has an input terminal connected to the other ends of the switches SW3 and SW4.

The operation of such an apparatus will be described.
First, when performing the gradation voltage test, the control unit 4 turns on the switches SW1 and SW3, turns off the switches SW2 and SW4, and turns off the voltage generation unit 2. A signal is supplied from a signal generator (not shown) to the DUT 1, and the DUT 1 outputs a gradation voltage. This gradation voltage is converted into digital data by the A / D converter 31 via the switches SW1 and SW3, and is output to the control unit 4. The control unit 4 determines whether the gradation voltage is an expected value voltage based on the digital data, and determines whether the DUT 1 is good or bad. When DUT1 is a source driver, the line path is selected with an output range of 0 to 20 V for the gradation voltage, but when the gate driver is an output range of 0 to 40 V, the attenuator path with resistors r1 and r2 is selected. Is done.

  Next, in the case of the inter-pin resistance test, the control unit 4 turns on the switches SW1 to SW3 and turns off the switch SW4. Then, the control unit 4 causes the voltage generation unit 2 to generate a voltage, and a current flows through the inter-pin resistance R. Then, current flows through the switch SW2 and the resistors r1 and r2, and the voltage generated by the resistors r1 and r2 is converted into digital data by the A / D converter 31 and output to the control unit 4. The control unit 4 determines whether the DUT 1 is good or bad based on the digital data.

  Here, the quality determination method of the inter-pin resistance test will be described. The voltage output from the voltage generator 2 is “V”, the resistance value “R” of the inter-pin resistor R, the resistance values of the resistors r1 and r2 are “r1” and “r2”, respectively, and the current flowing through the inter-pin resistor R is “ i ”and the voltage measured by the voltage measuring unit 3 is“ v ”. When these relationships are expressed in equations, V = i · (R + r1 + r2) and v = i · (r1 + r2). Then, v = (r1 + r2) · V / (R + r1 + r2). As a condition for the determination value, if R is large, it is difficult for current to flow between the pins. Therefore, determination is made by v <(r1 + r2) · V / (R + r1 + r2). Therefore, it is possible to determine whether the DUT 1 is good or bad by obtaining only v.

  In this way, the current of the inter-pin resistance test is converted into a voltage by the resistance of the attenuator of the voltage measuring unit 3, and the pins of the DUT 1 are measured at the same time. Therefore, the inter-pin resistance of the DUT 1 is not provided for each pin. Tests can be shortened.

  Further, during the inter-pin resistance test, the resistors r1 and r2 are used as one resistor, the current is converted into a voltage, and a minute current can be tested with the voltage measuring unit 3 with high sensitivity.

  Note that the present invention is not limited to this, and an example in which the DUT 1 and the voltage generator 2 are connected is shown. However, a switch is provided on the path between the DUT 1 and the voltage generator 2 so that the switch can be disconnected. It may be configured.

  Moreover, although the example in case the voltage measurement part 3 has one attenuator was shown, there may be multiple. In the inter-pin resistance test, the configuration is shown in which the voltage is obtained by using the resistors r1 and r2 as one resistor. However, the switches SW1 and SW3 are turned off, the switches SW2 and SW4 are turned on, and the A / D converter 31 is The voltage divided by the resistors r1 and r2 may be measured.

  Moreover, although the control part 4 is determining the quality of DUT1 in the inter-pin resistance test with a voltage value, you may determine by determining resistance value.

  The order of the gradation voltage test and the inter-pin resistance test may be reversed.

It is the block diagram which showed one Example of this invention. FIG. 4 is a diagram showing a specific configuration of a voltage measurement unit 3. It is the figure which showed the specific structure of the liquid crystal drive driver. It is the figure which showed the structure of the conventional IC tester.

Explanation of symbols

1 DUT
2 Voltage generation unit 3 Voltage measurement unit SW1 to SW4 switch r1, r2 resistance 31 A / D converter 4 control unit R resistance between pins

Claims (3)

In an IC tester for testing a liquid crystal drive driver that outputs a multi-gradation voltage,
A voltage generator for applying a voltage to a plurality of pins of the liquid crystal drive driver;
A voltage measuring unit that is provided for each pin that outputs a multi-gradation voltage of the liquid crystal drive driver, the input can be attenuated by an attenuator by resistance voltage division, and the voltage is measured;
The voltage generator is turned off during a grayscale voltage test, a grayscale voltage test is performed based on the voltage value measured by the voltage measurement unit, and a voltage is applied to the voltage generator during a pin-to-pin resistance test. A control unit that causes the voltage measurement unit to measure a voltage due to the resistance of the attenuator of the voltage measurement unit corresponding to the pin adjacent to the pin to which the voltage is applied, and to determine a resistance test between the pins based on the measurement result IC tester characterized by   2. The IC tester according to claim 1, wherein the voltage measuring unit measures the voltage by converting the current into the voltage by using the two voltage dividing resistors of the attenuator as one resistance during the inter-pin resistance test. The voltage measurement unit
A first switch electrically connecting one end to a pin of the liquid crystal drive driver;
A second switch for electrically connecting one end to the pin of the liquid crystal drive driver;
A first resistor connecting one end to the other end of the second switch;
A second resistor for connecting one end to the other end of the first resistor and grounding the other end;
A third switch connecting one end to the other end of the first switch;
A fourth switch connecting one end to the other end of the first resistor;
3. The IC tester according to claim 1, further comprising an A / D converter that connects an input terminal to the other end of each of the third and fourth switches.

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