JPS6210695A - Inspection of ic packaged substrate for display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for inspecting a substrate of a matrix type display device, which makes it possible to easily detect a defective substrate.

[Conventional technology]

Conventionally, the output pads for column electrodes were visually inspected in 1. I was checking one thing.

[Problem that the invention seeks to solve]

When using the conventional method, inspection errors and inspection omissions may occur due to worker fatigue and exhaustion, and if the number of output pads for column electrodes increases, these □ are expected to increase significantly. Furthermore, the measurement time increases, leading to an increase in cost. The present invention aims to solve the above-mentioned problems, reduce costs by shortening time, and improve accuracy.

[Means for solving problems]

The inspection method according to the present invention to achieve the above object is as follows.

Corresponding to a matrix type display panel having a plurality of row electrodes and a plurality of column electrodes, it has a plurality of row electrode output pads and a plurality of column electrode output pads, and the row electrodes and the row electrode pads, the column electrodes and the columns In the method for testing an IC mounting board for a matrix display device, the matrix type display panel can be driven according to display data given by connecting the column electrode pads to the electrode pads adjacent to each other. The present invention is characterized in that the display data is applied so that different output signals appear, and the short circuit state of the column electrode output pad is detected by measuring the current consumption of the IC mounting board in this state.

[Effect]

Different output signals are made to appear on a certain column electrode output pad and an adjacent column electrode output pad. At this time, if the column electrode output pad and the adjacent column electrode output pad are short-circuited, a short-circuit current will flow there, thereby changing the current consumption. A short circuit can be detected by this current change.

[Examples] Examples of the present invention will be described in detail below with reference to the drawings. 1st
The figure is a circuit diagram of an IC mounting board, and the area within the dotted line is an IC mounting board 100 (hereinafter referred to as IC
(abbreviated as mounting board). This includes segment output pads 1 to 5 to form a matrix structure of 5 rows and 5 columns.
Common output pads 11 to 15 are arranged at the same pitch as the pattern of a liquid crystal display element, which will be described later. Segment output pads 1 to 5 are connected to segment driver ICs 6 to 10, respectively, and common output pads 11 to 15 are connected to segment driver ICs 6 to 10, respectively.
A common driver IC 16 is connected to. Resistors 17 to 21 are power supplies for driving the liquid crystal, respectively, and supply common segment selection voltages and non-selection voltages. C,
D and E are terminals for the power supply vDD, -power supply ■□, and GND, respectively, F is a frame signal that outputs one pulse for each screen, G is each display data terminal, and H is a control signal terminal. 22 is a resistor for observing current changes, and A and B are terminals for observing the voltage across the resistor 220. A method of testing a liquid crystal display element using the IC mounting board 100 shown above will be explained. FIG. 2 shows the display state of the liquid crystal display element,
The second figure is a state diagram showing the waveform at that time, the second figure is a display state diagram of the liquid crystal display element, and the second figure is an observed waveform diagram.

First, the liquid crystal display element 200 shown in the second position is attached to the segment output pads 1 to 5 and the common output pads 11 to 15 of the IC mounting board 100 shown in FIG. 1, with each electrode connected. Next, each power terminal C, D of the IC mounting board 100
, H, each control signal is supplied to the control terminal H, and a second signal is supplied to the display data terminal G.
A display data signal is supplied that provides a rotation display state. In this state, connect the A terminal to the GND terminal of the oscilloscope, the B terminal to the channel 2 terminal, and the F terminal to the channel 1 terminal.
Connect each terminal and trigger the oscilloscope with a frame signal. As a result, as shown in FIG. 2 (Bl), the time during which the adjacent segment output pads output different drive voltages is T, and the time during which they output the same drive voltage is TY.

At this time, it is assumed that there is a short circuit between the output pads 2 and 3 of the segment. At time T, output pad 2 of the segment
-6 are at different potentials, so a short circuit current flows, and at time T1, the output pads 2 and 3 of the segment are at the same potential, so no short circuit current flows. If this state is observed with an oscilloscope, a waveform like that shown in FIG. 2(B) will be obtained, indicating that there is a short circuit.

Next, FIG. 3 shows another example of application. This is a case where display data is supplied to the liquid crystal display element 200 so as to produce a display similar to that of the third device, and similarly to the embodiment shown in FIG.
When there is a short circuit between segment output pads 2 and 3, the waveform that can be observed with an oscilloscope is shown in FIG. 3B). At time T1, segment output pads 2 and 3 are at the same potential and no short circuit current flows; at time T2, segment output pads 2 and 3 are at different potentials and a short circuit current flows; and at time T3, short circuit current flows. Similarly, no short circuit current flows. As described above, by supplying appropriate display data that matches the state of the output pad, the location of the short circuit can be found accurately and quickly.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is possible to significantly reduce worker fatigue, inspection errors, inspection omissions, etc., and is particularly effective for large matrix displays. As a result, effects such as cost reduction due to time reduction and improved accuracy can be obtained.

[Brief explanation of drawings]

The drawings all show embodiments of the present invention, and the first
The figure shows the circuit diagram of the IC mounting board, Figures 2 and 3 show the display state of the liquid crystal display element, and Figure 3 (3) shows the display state of the liquid crystal display element. , Figure 2 (B),
FIG. 3B) shows an observed waveform diagram. 100...IC mounting board, 200...Liquid crystal display element.

Claims (1)

[Claims] Corresponding to a matrix type display panel having a plurality of row electrodes and a plurality of column electrodes, it has a plurality of row electrode output pads and a plurality of column electrode output pads, and the row electrodes and the row electrode pads, the column electrodes and the columns In the method for testing an IC mounting board for a matrix display device, the matrix type display panel can be driven according to display data given by connecting electrode pads to the output pads adjacent to the column electrode output pads. An IC mounting board for a display device, characterized in that a short-circuit state of a column electrode output pad is detected by applying the display data so that different output signals appear and measuring current consumption of the IC mounting board in this state. inspection method.