JP3199827B2 - Integrated circuit element and electronic device using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated circuit device which facilitates inspection based on a signal appearing at an output terminal and an electronic device using the same.

[0002]

2. Description of the Related Art Active matrix type liquid crystal display devices have been attracting attention as being capable of inexpensively realizing a flat panel display device having a display quality comparable to that of a CRT and a high definition projection TV. This liquid crystal display device has hundreds to thousands of address lines and data lines formed on a matrix substrate, and an integrated circuit (IC) for driving the lines.
Is provided, but the number of pixels increases, fine pitch,
In order to reduce the size and cost, it is required to arrange as many drive output terminals as possible at a fine pitch in one drive IC.

Conventionally, TAB (Tape Automated Bonding) has been used to connect this type of driving IC to address lines and data lines.
g) The method is generally used, but a method of directly connecting a bare IC chip such as a COG (Chip On Glass) mounting method capable of a finer connection pitch has been actively developed. The possible connection pitch can be as fine as several tens μm to several μm in the COG method, compared to about 100 μm in the TAB method.

[0004] However, the COG method has some problems to be overcome in actually using it. One of them is a method of inspecting an IC to be mounted. Conventionally, test probe pins were simultaneously applied to almost all terminals in a wafer state, operation was confirmed, good products were discriminated, and non-defective IC chips cut from the wafer were directly connected to wiring terminals on a matrix substrate. . Here, the number of IC terminals is 30 due to mechanical and dimensional restrictions of test probe pins.
It is said that only about 0 and the terminal pitch can be practically used up to about 80 μm. For this reason, in a future multi-terminal, fine-pitch semiconductor integrated circuit device, inspection becomes difficult, which leads to a decrease in reliability and an increase in cost.

When the number of terminals and the terminal pitch are limited in order to increase the reliability of the inspection, not only the definition of pixels is improved but also the size of the driving IC is reduced (the area of the terminal region is rate-limiting) and the number of used ICs is reduced. Therefore, it is difficult to reduce the cost and reduce the size of the liquid crystal display device. Furthermore, in the COG method, since the burn-in (initial failure detection by energization aging) process performed in the packaged IC cannot be passed, the IC failure is not clarified only after connecting to the matrix substrate and displaying an image. Happens. In this case, the liquid crystal display device ends up with a defective product. In some cases, defective ICs can be repaired, but in this case, the number of steps is increased.

[0006]

As described above, in the conventional inspection of a semiconductor integrated circuit device using a probe pin, the number of terminals of the device is limited to about 300 and the terminal pitch is limited to about 80 μm. It has been difficult to cope with the miniaturization of elements, the increase in the number of terminals, and the fine pitch of terminals. Further, even under the present circumstances, it is difficult to inspect a multi-terminal, fine-pitch semiconductor integrated circuit element, which has led to a decrease in reliability and an increase in cost. In particular, in a driving IC or the like used for a liquid crystal display device, when the COG mounting method is adopted, there is a problem that an operation test and a mounting inspection of the driving IC become difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to enable easy inspection even if the number of terminals is large and the terminal pitch is fine, and the reliability is improved. It is an object of the present invention to provide an integrated circuit element which can contribute to improvement of the cost and reduction of the cost. It is another object of the present invention to provide an electronic device using the integrated circuit device.

[0008]

According to the gist of the present invention, in order to facilitate the inspection of an integrated circuit element, a switch circuit for selecting an output signal to the outside of the element is formed in the same element, and an output of the switch circuit is provided. Is a terminal to be inspected.

That is, the present invention relates to an integrated circuit device having an internal circuit formed on a substrate and having a predetermined function.
A plurality of output terminals formed on the same substrate as the internal circuit for extracting an output signal of the internal circuit to the outside;
A plurality of output terminals formed on the same substrate as the circuit
Inspection terminals provided at a ratio of one to
Switch between the terminal and the corresponding output terminal.
Output signals appearing at the output terminals.
And a switch circuit for selecting next.
Output signals sequentially selected by the
From the outside . As preferred embodiments of the present invention, those shown in the following (1) to (5) are described.
Ani-up it is. (1) The probe is applied to only the power supply terminal, the control terminal, and the inspection terminal without applying the probe to the output terminal of the integrated circuit element, and the energization or inspection is performed. (2) Make the power supply, control terminal, and inspection terminal larger than the dimensions or terminal pitch of the output terminal group. (3) The integrated circuit device of the present invention is used as a driving IC of a liquid crystal display device. (4) Inspection of an operation state including a connection state between the integrated circuit element and a wiring substrate such as a liquid crystal display device is performed based on an output signal of an inspection terminal of the integrated circuit element. (5) A MOS transistor is used as a switch circuit.

[0010]

A probe is applied to a power supply terminal and a control terminal of an integrated circuit element to operate an internal circuit, control is performed so that an appropriate output is sequentially output to a plurality of output terminals, and an output from a test terminal corresponding to the output is observed or data. By performing processing or the like and comparing the waveform with a normal waveform that should be output, the operation of the internal circuit can be confirmed without applying probe pins to hundreds of output terminals. Therefore, the inspection becomes extremely easy, and it is possible to improve the reliability and reduce the cost.

Further, since it is not necessary to apply a probe pin to the output terminal, the size and pitch of the output terminal can be made extremely small as compared with the prior art, so that not only high definition of the pixel but also miniaturization of the driving IC can be achieved. In addition, the cost can be reduced by reducing the number of used devices, and the size of the liquid crystal display device can be reduced. Furthermore, it is not necessary to apply test probe pins to many output terminals, and power is supplied with about 10 probe pins per chip.
Because it is possible to check the operation, it is possible to create a probe card that energizes all ICs simultaneously and checks the operation in the wafer state.
Burn-in in the wafer state and subsequent non-defective discrimination can be performed.

Further, in the liquid crystal display device having the integrated circuit element, the voltage change reflecting the state of electrical connection with the address lines and data lines formed on the matrix substrate serving as the load of the output terminal of the integrated circuit element. Can be appropriately observed from the inspection terminal, so that it is possible to detect whether or not the electrical connection is normal.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram including an equivalent circuit showing a first embodiment of the present invention. Figure is divided into a matrix substrate of the integrated circuit portion and the liquid crystal display device, both are electrically connected by the connecting material 6 ₁ to 6 _N.

First, the integrated circuit section will be described separately. Integrated circuit includes an internal circuit consisting of a shift register 1 and the sample hold circuit 2 ₁ to 2 _N, examination terminal 3,
Selection switch 4 ₁ to 4 _N, and an output terminal 5 ₁ to 5 _N, and other terminals 11 to 15. This example
The so-called analog driver IC having a sample and hold circuit 2 ₁ to 2 _N, selected as a circuit for selectively outputting the test terminal 3 a "signal corresponding to the potential of the plurality of output terminals 5 ₁ to 5 _N feature of the present invention switches 4 ₁ is obtained by adding a to 4 _N ".

The display image signal (Sig) is input to the terminal 14, is distributed to a plurality of output terminals 5 ₁ to 5 _N in a conventional manner. That is, the shift register 1 is operated by two control signals (clock (CLK) and shift start signal (Din)) inputted from the terminals 11 and 12, and the shift register outputs 10 ₁ to 10 ₁ .
Is output sequentially pulsed to 10 _N, a display image signal in response thereto (Sig) is sequentially sample and hold, is distributed to a plurality of output terminals 5 ₁ to 5 _N.

The selection switch 4 ₁ to 4 _N is an analog switch by a MOS transistor or the like, sequentially turned on synchronously with the sampling and holding operation, sequentially selects and outputs the potential of the output terminal 5 ₁ to 5 _N to the inspection terminal 3. At this time, the operation of the integrated circuit itself can be confirmed by sequentially comparing the display image signal (Sig) and the output signal of the inspection terminal 3. In this example, if they match at the set timing, it is normal, otherwise it is bad. Here, instead of from the output 20 ₁ to 20 _N of the sample-and-hold circuit 2, the reliability of inspection is improved by directly connecting the output terminal 5 ₁ to 5 _N to the selection switch 4 ₁ to 4 _N. FIG. 2 shows a schematic timing chart at this time.

[0018] Instead of applying such a large number of output terminals 5 probe directly to ₁ to 5 _N, you can check the operation of the integrated circuit device by applying a probe to the inspection terminal 3. For this reason, the inspection using the probe can be easily and reliably performed, and the reliability as an element and the cost can be reduced. Further, since there is no need to apply the probe to the output terminal 5 ₁ to 5 _N, the output terminal 5 ₁ to 5 _N
Can be made extremely small in size and pitch as compared with the prior art.

FIG. 3 shows a terminal arrangement diagram of the integrated circuit chip. Output terminal 5 ₁ to 5 _N pitch 20 [mu] m, size 10
The number of terminals is 500 μm square, and the power supply terminals 16 and 17, the input terminal 15 for the display image signal (Sig), the inspection terminal 3, the clock terminal 11, the shift start signal terminal 12, the shift signal output terminal 13, and the like have pitches. The minimum size is 200 μm and the size is 100 μm square.

The outer diameter of the integrated circuit chip is shown in FIG.
10.5 mm x 2.2 mm, and 4 mm in Fig. 3B.
A corner and an extremely small chip area for 500 outputs could be obtained. In addition, since energization and operation can be checked with roughly 10 probe pins having a coarse pitch per chip, a probe card can be created to simultaneously energize and check operation of all ICs in a wafer state, and burn-in and subsequent burn-in in a wafer state can be made. Good products could be identified.

Next, the inspection of a liquid crystal display device provided with this integrated circuit element will be described. In Figure 1, the data line terminal 7 ₁ to _7-N of the matrix substrate of the output terminal 5 ₁ to 5 _N and a liquid crystal display device of the integrated circuit portion, connecting material 6 ₁
6 _N electrically connected. Data line is several tens pF
Has a number 100pF wiring capacitance (C _L) from a load on the output terminal 5 ₁ to 5 _N of the integrated circuit portion. This embodiment, the integrated voltage of dependent output terminal to the load capacitance of the output terminal of the circuit portion so as to change, the integrated circuit portion of the output terminal 5 ₁ to 5 _N and the data line terminal ₇₁ of the matrix board unit ~
Electrical connection between 7 _N is that to be able to be detected from the inspection terminal 3 or have been made correctly.

The operation for this will be described below. The control terminal 15, a buffer amplifier driving capability of the sample hold circuit 2 within _one to 2 _N and controls small as 1 / 10-1 / 100 of the normal. Thus, if a data line terminal 7 ₁ to _7-N of the output terminal 5 ₁ to 5 _N and the matrix substrate of the integrated circuit portion is long as it is normally connected, the integrated circuit for load to become wiring capacitance (C _L) the output terminal of part 5 ₁
The potential of 5 _N cannot be driven until normal driving and becomes small.
If the connection is poor, the value is not much different from that during normal driving. By observing this difference from the inspection terminal 3, it is possible to detect whether or not the electrical connection is normal.

[0023] Incidentally, the capacitance per terminal of the output terminal 5 ₁ to 5 _N in the following 1 pF / degree, the selection switch 4 _1-4
Since the capacitance of the _N and the common wiring 30 can be about several pF to several tens of pF, which is about one digit smaller than the wiring capacitance (CL) as a load, it can be sufficiently determined. When the wiring capacitance of the external wiring (not shown) connected to the inspection terminal 3 is large, a decrease in the certainty of determination can be prevented by adding a buffer amplifier between the common wiring 30 and the inspection terminal 3. .

According to the present embodiment, the power supply terminal of the integrated circuit device to operate the circuit applying a probe to the input terminal and the control terminal or the like, sequentially appropriate output to a plurality of output terminals 5 ₁ to 5 _N Control so that it comes out, and the inspection terminal 3 corresponding to it
By observing the output of the integrated circuit or performing data processing and comparing it with the normal waveform that should be output, the operation of the integrated circuit element can be confirmed without applying probe pins to hundreds of output terminals. For this reason, the inspection using the probe can be easily and reliably performed, and the reliability as an element and the cost can be reduced.

Further, the size and pitch of the output terminals 5 ₁ to 5 _N can be extremely reduced than the conventional, not only high definition of pixels, low cost due to size and use reducing the number of the drive IC And the size of the liquid crystal display device can be reduced.
Furthermore, a number of output terminals 5 is not necessary to apply the test probe pins ₁ to 5 _N, 1 energized by probe pins 10 present approximately per chip, it is possible to confirm the operation, at the same time energizing confirmation and operation all the IC in wafer state There is also an advantage that burn-in in a wafer state and subsequent non-defective product discrimination can be performed.

Next, a second embodiment relating to such an electrical connection inspection will be described with reference to FIG. FIG. 4 is a circuit diagram including an equivalent circuit corresponding to one i-th circuit of the N circuits in FIG. First control terminal 15a
A sample and hold circuit 2 ₁ to 2 or the output of the buffer amplifier in the _N transmits to the output terminal 5 ₁ to 5 _N, and controls whether to float. Selection switch 4 ₁ to 4 _N is controlled to be turned on and off by the logical product of the second control terminal 15b and the shift register output 10 ₁ to 10 _N.

FIG. 5 shows a timing chart, and the operation is as follows. First, is transmitted to the first control terminal 15a controls the output terminal 5 ₁ to 5 the output of the buffer amplifier _N,
The wiring capacitance ( _CL ) serving as a load is charged to a desired voltage. In this case the selection switch 4 ₁ to 4 _N is kept in the off state by the second control terminal 15b. Next, after the output of the first control terminal 15a of the control to the buffer amplifier in a floating state, and controls the second control terminal 15b to selectively switch 4 ₁ to 4 _N (4i in this case) is turned on . As a result, the electric charge charged in the wiring capacitance (here, C _Li ) is distributed to the capacitance of the common wiring 30, and the potential is output to the inspection terminal 3 via the buffer 3a. After that, the reset switch 3b is turned on to discharge the electric charge accumulated in the capacitance of the common wiring 30, reset to the initial state, and wait for the next i + 1-th circuit to flow electric charge. The detected voltage V _3i is given by the following equation.

V _3i = V _Sig-i · (C _5i + C _Li ) / (C _5i
+ C _Li + C ₃₎ where, V _Sig-i is an input voltage corresponding to the i-th display image signal (Sig), C _5i capacity corresponding to the i-th node of the output terminal 5 ₁ ~5 _N, C _Li Is the wiring capacitance (C
Capacity corresponding to the i-th _L), C ₃ is a capacity corresponding to the node of the common wiring 30.

The principle of inspection and determination of electrical connection will be described based on the respective representative values. 1 pF for C _5i and 10 p for C ₃
Assuming that F and C _Li are 50 pF, the output terminal 5 of the integrated circuit section is
If i is properly connected to the data line terminal 7i of the matrix substrate, V _3i = 0.84 · V _Sig-i. If not, C _Li is equivalent to 0 pF. V _3i = 0.09 · V _Sig-i V _Sig-i is several volts
Therefore, the two can be easily distinguished from each other sufficiently larger than the circuit noise, and a semi-incomplete connection state can be accurately determined.

As described above, a voltage change reflecting an electrical connection state with an address line and a data line formed on a matrix substrate serving as a load of an output terminal of an integrated circuit element can be appropriately observed from an inspection terminal. , It can also be detected that the electrical connection has been made normally. It goes without saying that this circuit configuration can also be used for the above-described inspection of the integrated circuit element alone.

In the above embodiment, the integrated circuit for a data line driver of a liquid crystal display device has been described. However, it is needless to say that the present invention can be applied to an integrated circuit for an address (gate) line driver. Further, by using several types of patterns as the signal pattern of the display image signal (Sig) and judging the normality / failure comprehensively from the results, it is possible to determine the failure mode with higher accuracy and furthermore. . In addition to active matrix liquid crystal displays,
It goes without saying that it can be used for the simple matrix method.

Next, a third embodiment relating to a liquid crystal display device using such an integrated circuit device will be described. FIG. 6 is a block diagram thereof. For the sake of simplicity, unnecessary details have been omitted.

The liquid crystal display panel unit 70 is driven by data line driving integrated circuit elements 80 ₁ to 80 _M and address line driving integrated circuit elements (not shown). Here, the integrated circuit elements 80 ₁ to 80 _M is obtained by incorporating a switch circuit for extracting selected as described in the previous example, the driving output signal to the test terminal. The signal DET from the inspection terminal is an analog / digital converter (A / D) 10
The data is converted into digital information by the data 2 and stored in the correction data storage memory 101 as correction data. The arithmetic circuit 100 based on this correction data, performs correction operation on the display image signal Sig0 sent from the external system, so that the corrected display image signal Sig is integrated data line driving circuit elements 80 ₁ to 80 _M , and drives the liquid crystal display panel unit 70 with a drive signal based on it.

The features of this embodiment will be described in comparison with a conventional example. FIG. 7A is a graph showing general input / output characteristics of a data line driving integrated circuit element. The voltage Vgig of the input display image signal and the voltage Vout of the output signal output to the data line ideally match, but at least the input / output characteristics of all output terminals should be as uniform as possible. Required. However, the O shown in the figure
Like the UT1 and OUT2, there is actually an offset variation and a gain variation of the internal amplifier circuit, and the voltage applied to the data lines of the liquid crystal display panel is as shown in FIG.
As shown in (b), variations occur between terminals. This voltage variation varies from 40 mV to 100 m depending on the configuration.
Vp-p, which was visually recognized as vertical streak noise depending on the type of display image, and prevented improvement in display quality.
This voltage variation can be reduced in principle by improving the transistor characteristics of the first stage of the amplifier circuit in the integrated circuit and by improving the characteristics of the sample-and-hold circuit. Although many sacrifices such as power, chip area, operating speed, and cost were required, no significant improvement in characteristics could be achieved.

In the configuration of this embodiment, display image signals of various test patterns are passed in advance, output signals corresponding to the test patterns are sequentially selected, read from the inspection terminal, and stored as correction data in the memory element. The input / output characteristics of integrated circuit elements and their variations are corrected, and as a result, the variations in the voltage applied to the data lines of the liquid crystal display panel can be made extremely small. Performance can be improved.

Specifically, the A / D conversion and the correction operation processing are performed in 8 bits, so that the voltage variation is 10 mVp-
improved to less than p. The correction calculation at this time is as follows:
The difference is corrected for the offset voltage and the gain, and a difference operation (for offset) and a division operation (for gain) are performed based on the correction data. As an arithmetic circuit, a normal arithmetic circuit using an operational amplifier and a D / A converter is sufficient. Normal RAM was used as the memory element,
The required memory capacity depends on the number of data lines 192 that is typical.
In the case of 0 lines (640 pixels x 3 colors of B, G, B),
A small one of 31 k bits ((8 bits + 8 bits) × 1920) is sufficient.

In addition to the above, various modifications are possible as the correction data and the correction calculation method depending on the characteristic to be corrected. For example, not only the offset voltage and the gain but also the linearity of the input / output characteristics can be corrected by the same method. Also, by storing the input / output nonlinear data (as known) of the active element inside the liquid crystal display panel together with the linearity correction data,
Higher display quality can be obtained. Furthermore, the problem that the voltage level difference between adjacent outputs to the data lines due to the frequency band characteristics of the internal circuit of the integrated circuit element is smaller than the input display image signal and the display resolution is deteriorated is also a problem that the test pattern corresponding to such waveforms By storing the signal from the inspection terminal at the time of input as correction data and performing a correction operation that emphasizes the difference between adjacent terminals, it is possible to display a high-quality image with good display quality. .

Although the input / output characteristics of the integrated circuit element may change with time or change with time, the correction data may be appropriately updated with a signal from the detection terminal, so that the change with respect to temperature and change with time. Constant display performance is obtained. On the other hand, when such a change in temperature or change with time can be ignored, the A / D converter 102 in FIG. 6 can be separated from the liquid crystal display device set to reduce the cost. That is, an A / D converter may be provided in the adjustment device at the time of shipment from the factory, and PROM may be used as the memory element 101 to store correction data therein.

Although a liquid crystal display device has been described as an embodiment of the present invention, other electronic devices having the same configuration,
For example, the present invention can be applied to a communication switching hybrid module, a printer head, an image reading sensor, and the like.

[0040]

As described above in detail, according to the present invention, a switch circuit for selecting an output signal to the outside of an integrated circuit element is formed in the same element, and the output of the switch circuit is used as a terminal to be inspected. Even if the number of terminals is large and the terminal pitch is fine, the inspection can be easily performed, and an integrated circuit element that can contribute to improvement in reliability and reduction in cost can be realized. In addition, since the size and pitch of the output terminals can be made extremely small as compared with the conventional case, not only high definition of pixels but also low cost by reducing the size and number of driving ICs and miniaturization of the liquid crystal display device are achieved. Is possible. Further, it is possible to correct the non-uniformity of the input / output characteristics of the integrated circuit element and to achieve high image quality.

[Brief description of the drawings]

FIG. 1 is a block diagram including an equivalent circuit showing a first embodiment of the present invention;

FIG. 2 is a signal waveform diagram showing timing of each signal in the first embodiment;

FIG. 3 is a plan view showing a terminal arrangement of the integrated circuit chip according to the first embodiment;

FIG. 4 is a block diagram including an equivalent circuit showing a second embodiment of the present invention;

FIG. 5 is a signal waveform diagram showing timing of each signal in the second embodiment;

FIG. 6 is a block diagram showing a liquid crystal display device according to a third embodiment;

FIG. 7 is a diagram showing general input / output characteristics of an integrated circuit element and variations in output between terminals.

[Explanation of symbols]

1 ... shift register, 2 ₁ to 2 _N ... sample hold circuit, 3 ... inspection terminal, 4 ₁ to 4 _N ... selection switch, 5 ₁ to 5 _N ... output terminal of the integrated circuit unit, 6 ₁ to 6 _N ... connecting material , 7 _{1 to} 7 _N ... data line terminals of the liquid crystal display section, 11 ... clock terminals, 12 ... shift start signal terminals, 13 ... shift signal output terminals, 14 ... image signal input terminals, 15 ... control terminals, 30 ... common wiring Reference numeral 70: liquid crystal display panel unit, 81 ₁ to 80 _M : integrated circuit element, 100: arithmetic circuit, 101: memory element.

Claims (2)

(57) [Claims] An internal circuit 1. A formed on a substrate having a predetermined function is formed in the internal circuit on the same substrate, the inner
Multiple outputs for extracting the output signal of the external circuit
Terminals and the internal circuit are formed on the same substrate,
Inspection ends provided at a ratio of one to a plurality of force terminals
Between the inspection terminal and the corresponding output terminal.
Each switch is connected and appears at the output terminal.
And a switch circuit for sequentially selecting output signals to be output.
Ri, the output signals are sequentially selected by the switching circuit
An integrated circuit device which is taken out from a test terminal to the outside . 2. An integrated circuit device according to claim 1, a load circuit driven by the integrated circuit device, and a storage device for storing a plurality of pieces of output potential information from test terminals of the integrated circuit device. An electronic circuit, comprising: an arithmetic circuit that corrects an input signal input to the integrated circuit element based on information from the storage element.