Flexible circuit board for a display

Abstract

The present invention provides a flexible printed circuit board for a display, the flexible printed circuit board having a chip-on-film structure. Among them, the connection pattern selected as the first connection pattern from the connection patterns connected to the panel contact pads is restricted inside the product portion and does not contact the cutting line, thereby preventing the connection pattern selected as the first connection pattern from being exposed to the cutting profile of the cutting line and preventing the electrical characteristics of the connection pattern selected as the first connection pattern from being changed due to the penetration of moisture.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201880014940.2, titled "Flexible Circuit Board for Display", filed on February 14, 2018. Technical Field

[0002] Various embodiments generally relate to flexible circuit boards for displays, and more particularly, to flexible circuit boards for displays that mount drivers in a chip - on - film structure. Background Art

[0003] A display device includes a timing controller, a driver, and a display panel. The timing controller provides control data and display data to the driver, and the driver provides a source signal corresponding to the display data to the display panel.

[0004] Generally, the timing controller is mounted on a printed circuit board together with a power supply circuit, and the driver is mounted on a flexible circuit board in a chip - on - film structure.

[0005] The electrical connection between the printed circuit board and the flexible circuit board and the electrical connection between the flexible circuit board and the display panel are achieved through an anisotropic conductive film.

[0006] The driver is usually manufactured to have a rectangular shape. Pads for communicating with the timing controller and pads for receiving an input voltage are arranged at one long side (hereinafter referred to as the "input side") of the driver, and pads for providing a source signal and an output voltage to the display panel or for receiving a sensing signal obtained by sensing the characteristics of the pixels of the display panel are arranged at the other long side (hereinafter referred to as the "output side").

[0007] In an integrated circuit region defined on one surface of the flexible circuit board where the driver is provided, the flexible circuit board mounting the driver in a chip - on - film manner has contact pads for electrically connecting to the pads of the driver. Among the contact pads in the integrated circuit region, the contact pads corresponding to the pads on the output side of the driver can be identified as integrated circuit contact pads.

[0008] In addition, outside the integrated circuit region, the flexible circuit board has panel contact pads for electrically connecting to the display panel and test pads for testing the driver.

[0009] The integrated circuit contact pads and the panel contact pads are connected by a connection pattern for wiring on the flexible circuit board, and the panel contact pads and the test pads are connected by an extension pattern for wiring on the flexible circuit board.

[0010] In most cases, the connection pattern and the extension pattern of the flexible circuit board are formed on a base film and are protected by an upper cover film formed of a resin material.

[0011] Test the driver installed in the integrated circuit area of the flexible printed circuit board.

[0012] When the driver finishes the test, cut the flexible printed circuit board along the cutting line located between the panel contact pad and the test pad for commercialization. At this time, remove the portion where the extended pattern is formed and the test connection area of the test pad by cutting.

[0013] Through cutting, the end surface of the extended pattern is exposed on the cutting section.

[0014] The extended pattern is in a state where it is connected to the connection pattern that transmits power, source signals, and sensing signals along the wiring.

[0015] When the end surface of the extended pattern as described above is exposed on the cutting section, moisture can penetrate through the interface between the extended pattern and the cover film. The moisture may damage the extended pattern, and the damaged extended pattern may change the electrical characteristics of the connection pattern.

[0016] Among the power, source signals, and sensing signals, the sensing signal is particularly sensitive to changes in the electrical characteristics of the connection pattern. Therefore, when the extended pattern connected to the connection pattern that transmits the sensing signal (which is an important signal) is damaged by moisture penetration, it may cause changes in the electrical characteristics of the connection pattern. When the sensing signal is distorted due to changes in the electrical characteristics of the connection pattern, it may affect the operation of the driver and the operation of the display.

[0017] Therefore, in the case of a flexible printed circuit board on which a driver is installed, it is necessary to prevent the electrical characteristics of the connection pattern from being changed due to moisture penetration through the cutting section. Summary of the Invention

[0018] Technical Problem

[0019] Various embodiments relate to a flexible printed circuit board for a display, which can prevent the electrical characteristics of the connection pattern for transmitting signals (such as sensing signals that are sensitive to changes in electrical characteristics) from being changed due to moisture penetration.

[0020] Technical Solution

[0021] In an embodiment, a flexible printed circuit board for a display may include a base film, integrated circuit contact pads, panel contact pads, test pads, connection patterns, and extension patterns, wherein: the base film is divided into a product area and a test connection area based on a cutting line; the integrated circuit contact pads are disposed at one side of an integrated circuit area defined in the product area and are formed to make electrical contact with an integrated circuit; the panel contact pads are disposed between the integrated circuit contact pads and the cutting line and are formed to make electrical contact with a display panel; the test pads are formed in the test connection area; the connection patterns electrically connect a plurality of the integrated circuit contact pads and a plurality of the panel contact pads respectively; when at least one of the connection patterns is selected as a first connection pattern, the extension patterns extend from the remaining connection patterns not selected as the first connection pattern, and the plurality of extension patterns are electrically connected to the plurality of test pads respectively.

[0022] In an embodiment, a flexible printed circuit board for a display may include a base film, integrated circuit contact pads, panel contact pads, connection patterns, and extension patterns, wherein: the base film has a cutting line; the integrated circuit contact pads are disposed at one side of an integrated circuit area on the base film and are formed to make electrical contact with an integrated circuit; the panel contact pads are disposed between the integrated circuit contact pads and the cutting line and are formed to make electrical contact with a display panel; the connection patterns electrically connect a plurality of the integrated circuit contact pads and a plurality of the panel contact pads respectively; when at least one of the connection patterns is selected as a first connection pattern, the extension patterns extend from the remaining connection patterns not selected as the first connection pattern through the cutting line.

[0023] Advantageous Effects

[0024] According to an embodiment of the present disclosure, a flexible printed circuit board for a display can prevent the connection patterns for transmitting important signals (such as sensing signals) from having their electrical characteristics changed due to moisture penetration. Therefore, the stability of the operation of the driver and the operation of the display can be ensured. Description of the Drawings

[0025] Figure 1 is a top view showing an example of a flexible printed circuit board for a display according to an embodiment of the present disclosure.

[0026] Figure 2 is along Figure 1 Line A-A taken in cross-section.

[0027] Figure 3 is along Figure 1 Cutting line 40 taken in cross-section. Detailed Description of the Embodiments

[0028] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The terms used in this specification and the claims should not be construed as being limited to their ordinary or dictionary meanings, but rather should be interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure.

[0029] The embodiments described herein and the configurations shown in the drawings are preferred embodiments of the present disclosure, and since these embodiments and configurations do not represent all the technical features of the present disclosure, there can be various equivalents and modifications that can be made to the present disclosure when filing an application.

[0030] The present disclosure discloses an embodiment in which, in a display device using an active-matrix organic light-emitting diode (AMOLED), a flexible printed circuit board that electrically connects a display panel to a driver and mounts the driver in a chip-on-film structure is improved. The electrical characteristics of the display device can be improved through the embodiments of the present disclosure.

[0031] Figure 1 A flexible printed circuit board for a display is shown, which is divided into a product region PR and a test connection region TR based on a cutting line 40.

[0032] The flexible printed circuit board for a display is shown as being manufactured in a rectangular shape and can be configured in a roll form.

[0033] In the product region PR, an integrated circuit region 20 is defined, and a driver (not shown) will be mounted in the integrated circuit region 20 in a chip-on-film structure. The integrated circuit region 20 can be defined in a rectangular shape having long sides facing each other.

[0034] Figure 1 The flexible printed circuit board for a display shown has a structure in which pads and patterns are formed on a base film 10, and a cover film 12 is applied on the base film 10.

[0035] The base film 10 can be constituted by an insulating film formed of a flexible material, and in most cases, a polyimide film is used. The pads and patterns can be formed using a conductive material such as copper. The upper cover film 12 can use a resin material and can be formed by coating.

[0036] The pads and patterns on the flexible printed circuit board can include integrated circuit contact pads 22, panel contact pads 24, test pads 34, connection patterns 30, and extension patterns 32. Among them, the connection patterns 30 and the extension patterns 32 are covered by the cover film 12, and the integrated circuit contact pads 22, the panel contact pads 24, and the test pads 34 are not covered by the cover film 12 and are exposed.

[0037] In the product region PR separated by the cutting line 40, there are included parts of the integrated circuit contact pads 22, the connection patterns 30, the extension patterns 32, and the panel contact pads 24.

[0038] In the test connection region TR separated by the cutting line 40, the remaining parts of the extension patterns 32 and the test pads 34 are formed.

[0039] In the integrated circuit region 20, integrated circuit contact pads may be formed, where the integrated circuit contact pads correspond to the pads on the input side and the output side of the driver mounted in a chip - on - film structure. In the embodiments of the present disclosure, for ease of explanation, the illustration of the integrated circuit contact pads corresponding to the pads on the input side of the driver is omitted, and the integrated circuit contact pads 22 corresponding to the pads on the output side of the driver are shown in the integrated circuit region 20.

[0040] The integrated circuit contact pads 22 may be arranged parallel to one long side of the integrated circuit region 20 at a position adjacent to the one long side. Specifically, the integrated circuit contact pads 22 are arranged in a row in a separated state to correspond to the positions of the pads on the output side of the driver provided, and the integrated circuit contact pads 22 are positioned in the integrated circuit region 20.

[0041] The panel contact pads 24 are formed outside the integrated circuit region 20 and are arranged between the integrated circuit contact pads 22 and the cutting line 40. The panel contact pads 24 are formed for electrical contact with the display panel. Specifically, the panel contact pads 24 are arranged in a row in a separated state at a position parallel to the integrated circuit contact pads 22 and adjacent to the cutting line 40.

[0042] The connection patterns 30 are formed to electrically connect the plurality of integrated circuit contact pads 22 and the plurality of panel contact pads 24 respectively. The connection patterns 30 may be configured to have the same line width and be configured to be separated from each other.

[0043] The corresponding connection patterns 30 are configured such that one end thereof is in electrical contact with the integrated circuit contact pads 22 respectively, and the other end thereof is in electrical contact with the panel contact pads 24 respectively. For this purpose, the corresponding connection patterns 30 may have one end on which the integrated circuit contact pads 22 are formed for electrical contact, and the other end on which the panel contact pads 24 are formed for electrical contact. This will be described below with reference to Figure 2 This is described.

[0044] In the test connection region TR separated by the cutting line 40, the test pads 34 are formed.

[0045] The extended pattern 32 is configured to electrically connect the plurality of connection patterns 30 and the plurality of test pads 34 respectively. The extended pattern 32 can be configured to have the same line width and be configured to be separated from each other.

[0046] Specifically, at least one of the connection patterns 30 formed in the product region PR can be defined as the first connection pattern, and the extended pattern 32 is configured to electrically connect the remaining connection patterns 30 that are not selected as the first connection pattern and the corresponding test pads 34 respectively.

[0047] The test pads 34 are dispersedly arranged at multiple positions in the test connection region TR to physically contact the test pins (or leads) constituting the test device or the test card, and are configured to have different areas at the corresponding positions.

[0048] For example, the test pads 34 can be arranged in a matrix structure having rows and columns. As the distance from the cutting line 40 increases, the area of the test pads 34 can increase.

[0049] The extended pattern 32 can be formed with a curved wiring pattern to electrically connect to the test pads 34 having different positions and different areas.

[0050] In the above configuration, the following will refer to Figure 2 Describe the structures of the connection pattern 30 and the panel contact pad 24. Figure 2 is a cross-sectional view taken along line A-A of Figure 1 The connection patterns 30 are formed on the base film 10 at a predetermined distance from each other, and the panel contact pads 24 are formed on the connection patterns 30.

[0051] The connection patterns 30 and the panel contact pads 24 can be formed using the same conductive material or different conductive materials, and can be formed by various methods such as wet etching.

[0052] After forming the connection patterns 30 and the panel contact pads 24, the cover film 12 is applied by coating to cover the connection patterns 30 and the base film 10.

[0053] At the same time, the extended pattern 32 can be formed to extend integrally from the connection pattern 30 and have a width narrower than that of the connection pattern 30.

[0054]

[0055] Figure 3 Refer to Figure 3 It can be understood that the extended patterns 32 are formed on the base film 10 at a predetermined distance from each other. The extended patterns 32 are covered by the cover film 12. Figure 3 is a cross-sectional view taken along the cutting line 40.

[0056] The connection pattern 30 is formed to be restricted within the product area PR without extending to the cutting line 40. That is, the entire connection pattern 30 is formed to have a length on the cutting section that is not exposed after cutting is performed along the cutting line 40. Figure 3 of the cutting section.

[0057] In the connection pattern 30, the connection pattern that transmits important signals (such as sensing signals obtained by sensing information related to the characteristics of the pixels of the display panel) can be defined as the first connection pattern.

[0058] The connection pattern 30 can be divided into a connection pattern for transmitting power, a connection pattern for transmitting source signals, and a connection pattern for transmitting sensing signals.

[0059] In an embodiment of the present disclosure, all the connection patterns 30 that transmit sensing signals can be defined as the first connection pattern.

[0060] Specifically, in an embodiment of the present disclosure, the extension pattern 32 can be integrally connected to the end portions of the remaining connection patterns 30 other than the connection pattern 30 that transmits sensing signals and facing the cutting line 40. On the other hand, the extension pattern 32 is not formed at the end portion of the connection pattern 30 that transmits sensing signals and faces the cutting line 40.

[0061] A plurality of extension patterns 32 pass through the cutting line 40 and are respectively connected to a plurality of test pads 34.

[0062] Therefore, as Figure 3 shown, in the case of cutting the base film 10 along the cutting line 40, the connection pattern 30 that transmits sensing signals is not exposed on the cutting section, but the end portion of the extension pattern 32 that is connected to the connection pattern 30 for transmitting source signals or power is exposed on the cutting section.

[0063] Therefore, in the present disclosure, since the extension pattern 32 is not connected to the connection pattern 30 that transmits sensing signals, it is possible to prevent moisture from penetrating through the extension pattern 32, and it is possible to prevent the electrical characteristics of the connection pattern 30 that transmits sensing signals from being changed due to the penetration of moisture.

[0064] Therefore, according to the present disclosure, the operation of the source driver and the stability of the display operation can be ensured.

Claims

1. A flexible printed circuit board for a display, comprising: A base film, divided into a product area and a test connection area based on a cutting line; A connection pattern, formed on the base film and restricted within the product area without extending to the cutting line, and including a first connection pattern and a second connection pattern, the first connection pattern transmitting a sensing signal obtained by sensing information related to the characteristics of pixels, and the second connection pattern transmitting a source signal and a power supply; Test pads, formed in the test connection area; An extension pattern, integrally extending from the second connection pattern and electrically connecting one end of the second connection pattern to the test pads; Panel contact pads, formed on one end of the connection pattern between the cutting line and an integrated circuit area defined within the product area; Integrated circuit contact pads, formed on the other end of the connection pattern extending into the interior of the integrated circuit area; And A cover film, covering the connection pattern, the extension pattern, and the base film, and exposing the integrated circuit contact pads, the panel contact pads, and the test pads, Wherein, the other end of the first connection pattern is not exposed on the cutting section after cutting along the cutting line, so as to prevent the electrical characteristics of the first connection pattern that transmits the sensing signal sensitive to changes in electrical characteristics from being changed.

2. The flexible printed circuit board according to claim 1, Among them, The cutting section of the extension pattern is exposed on the cutting section along the cutting line.

3. The flexible printed circuit board according to claim 1, Among them, The extension pattern has a width narrower than that of the second connection pattern.

4. The flexible printed circuit board according to claim 1, Among them, The panel contact pads are formed outside the integrated circuit area and are formed in a row adjacent to the cutting line.

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