JP6918094B2 - Flexible circuit board - Google Patents

Description

The present invention relates to a flexible circuit board.

Recently, as electronic devices have become smaller, chip-on-film (COF) packaging technology using a flexible circuit board has been used. Flexible circuit boards and COF packaging technology using them have been applied to flat panel displays (Flat Panel Display; FPD) such as liquid crystal displays (LCD) and organic light equity display devices. It will be used.

A conductive wiring pattern for transmitting an electrical signal can be formed on the flexible circuit board. In order to determine whether or not the conductive wiring is open / short-circuited, a separate test pad on the substrate or a probe that electrically contacts the via land surrounding the via can be used.

However, when forming a separate test pad, extra space is required on the substrate, which does not meet the needs for miniaturization of electronic devices. There is a problem that foreign matter and terminal defects occur.

A technical problem to be solved by the present invention is to provide a flexible circuit board capable of inspecting the presence or absence of a short circuit / opening without causing a terminal defect in the via land.

The technical problem of the present invention is not limited to the above-mentioned technical problem, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description.

The flexible circuit board according to the embodiment of the present invention for achieving the above technical problems includes a base board in which a test area is defined on one surface, and a first wiring pattern formed on the one surface of the base board. At least one first connection pad, which is electrically connected to each other, and a second wiring pattern arranged on the one surface of the base substrate and formed on the other surface opposite to the one surface of the base substrate, respectively, are electrically connected. Includes at least one second connection pad that is specifically connected and a test pattern that extends from the second connection pad onto the test area.

In some embodiments of the present invention, the test pattern is a first test pattern extending from the first connection pad onto the test area, and a second test extending from the second connection pad onto the test area. Can include patterns.

In some embodiments of the invention, the first test pattern and the second test pattern can be arranged intersecting within the test area.

In some embodiments of the present invention, the test area may include a first test area in which the first test pattern is located and a second test area in which the second test pattern is arranged.

In some embodiments of the present invention, the first test area or the second test area can be arranged between the first connection pad and the second connection pad.

In some embodiments of the invention, the first test area or the second test area can be located between the end of the flexible circuit board and the first connection pad or the second connection pad.

In some embodiments of the invention, the test pattern can be 45 to 135 degrees with respect to the probe scanning traveling direction.

In some embodiments of the invention, the second connection pad is electrically connected to the second wiring pattern and can vertically overlap with vias penetrating the base substrate.

According to the flexible circuit board according to the embodiment of the present invention, since the wiring pattern is not provided with a separate test pad for testing the presence or absence of a short circuit / opening defect, it is possible to have an advantageous effect on the miniaturization of the board.

Further, in the contact inspection using the probe, it is possible to reduce the occurrence of foreign matter and terminal defects in the vialand due to the contact while the probe is in contact with the test pattern instead of the vialand.

The effects of the present invention are not limited to those described above, and other effects not described above will be clearly understood by those skilled in the art from the claims.

It is a figure which shows the flexible circuit board which concerns on one Embodiment of this invention. It is sectional drawing which follows AA'in FIG. It is a figure which expands and shows the test area of the flexible circuit board which concerns on one Embodiment of this invention. It is a figure which shows the flexible circuit board which concerns on other embodiment of this invention. It is a figure which shows the flexible circuit board which concerns on other embodiment of this invention.

The advantages, features, and methods of achieving them of the present invention will become clear with reference to the embodiments described in detail below with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and is realized in various forms different from each other. However, the present embodiment is provided merely to complete the disclosure of the present invention and to fully inform a person having ordinary knowledge in the technical field to which the present invention belongs the scope of the invention. The present invention is defined only by the claims. The size and relative size of the components shown may be exaggerated for clarity of explanation. Throughout the specification, the same reference numerals refer to the same components, and "and / or" includes each and all combinations of one or more of the items described.

When an element or layer is described as being "on" of another element or layer, it is not only when it is directly above the other element or layer, but also between them. It also includes the case where a layer or another element is interposed. On the other hand, when an element is described as "directly on" or "directly above", it indicates that no other element or layer is interposed between them.

Spatically relative terms such as "lower", "beneath", "lower", "above", "upper", etc. are illustrated. As such, it can be used to easily describe the correlation between one element or component and another element or component. Spatial relative terms should be understood as terms that include different directions of the elements during use or operation, in addition to the directions shown. For example, when overturning the illustrated element, the element described as "below" or "beneath" of the other element can be placed "above" of the other element. Therefore, the exemplary term "down" can include all downwards and upwards. The device can be oriented in other directions as well. This allows spatially relative terms to be interpreted according to orientation.

The terms used herein are for purposes of describing embodiments and are not intended to limit the invention. In the present specification, the singular type also includes the plural type unless otherwise specified in the wording, and "comprises" and / or "comprising" are one or more other than the components mentioned. Does not preclude the existence or addition of components of.

Although terms such as "first" and "second" are used to describe various elements or components, it goes without saying that these elements or components are not limited by these terms. These terms are used solely to distinguish one element or component from another. Therefore, the first element or component referred to below may be the second element or component within the technical idea of the present invention.

Unless otherwise defined, all terms used in the present invention (including technical and scientific terms) may be used in a way that is commonly understood by those with ordinary knowledge in the technical field to which the present invention belongs. be. Also, terms defined in commonly used dictionaries are not ideally or over-interpreted unless explicitly specifically defined.

FIG. 1 is a view showing a flexible circuit board according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA'of FIG.

Referring to FIGS. 1 and 2, the flexible circuit board 1 according to the embodiment of the present invention includes a base board 10, a first wiring pattern 15 formed on one surface of the base board, a first connection pad 50, and a first. 2 The connection pad 30, the first test pattern 40, the second test pattern 20, and the second wiring pattern 16 formed on the other surface of the base substrate are included.

The base substrate 10 can be formed of a flexible material and is included in the flexible circuit board 1 as a base material so that the flexible circuit board 1 can be bent or broken. The base substrate 10 can be, for example, a polyimide film. Unlike this, the base substrate 10 may be a PET film, a polyethylene naphthalate film, a polycarbonate film, or an insulating metal foil. In the electronic device 1 according to the embodiment of the present invention, the base substrate 10 will be described as a polyimide film.

The first wiring pattern 15 can be formed on one surface of the base substrate 10. For convenience of explanation, one surface is on the base substrate 10 on which the first wiring pattern 15 and the first test pattern 40 are arranged, and the other surface is on the surface of the base substrate 10 on which the second wiring pattern 16 is arranged. And. As shown in FIG. 1, the first wiring pattern 15 may be a plurality of wiring patterns arranged apart from each other with a constant width and interval.

The first wiring pattern 15 can include, for example, a conductive substance such as copper, but the present invention is not limited thereto. Specifically, the first wiring pattern 15 may be made of an electrically conductive substance such as gold or aluminum.

The first wiring pattern 15 can include at least one sub-patterns 15_1 and 15_2.

The first wiring pattern 15 is connected to the first connection pad 50, respectively, and can transmit an electric signal to the first connection pad 50. Specifically, the first sub-pattern 15_1 may be connected to the first sub-pad 50_1 and the second sub-pattern 15_2 may be connected to the second sub-pad 50_2.

Further, the first wiring pattern 15 can be electrically connected to the first test pattern 40 via the first connection pad 50. Specifically, the first sub-pattern 15_1 can be electrically connected to the first subtest pattern 40_1 via the first subpad 50_1, and the second subpattern 15_2 is the second subtest via the second subpad 50_2. Can be electrically connected to pattern 40_2. One end of the first wiring pattern 15 may be connected to the first connection pad 50, and the other end of the first wiring pattern (not shown) may be connected to another pad or connection terminal.

Here, the first connection pad 50 is, for example, an outer lead for connecting to an external device connected to the flexible circuit board 1, and another pad connected to the other end of the first wiring pattern 15 is driven. It can be an inner lead on which the element is mounted.

In the flexible circuit board 1 according to the embodiment of the present invention, the short-circuit / open test using probe scanning is performed on the test patterns 20 and 40 on the test areas 25 and 35, so that the first wiring pattern 15 is It may be covered with a protective layer without being exposed. For example, at least a part of the first wiring pattern 15 may be covered with a solder resist.

As shown in FIG. 1, the first sub-pattern 15_1 and the second sub-pattern 15_2 constituting the first wiring pattern 15 extend in the third direction d3 and can be arranged so as to be separated from each other in the first direction d1. The invention is not limited to this. That is, such an arrangement is only one embodiment, and the first sub-pattern 15_1 and the second sub-pattern 15_2 are arranged so as to extend in the first direction d1 and to be separated from each other in the third direction d3. May be good.

The first connection pad 50 can be formed on one surface of the base substrate 10. The first connection pad 50 may be connected to the first wiring pattern 15 and may have a shape in which the width of the first wiring pattern 15 is expanded.

The first connection pad 50 may include at least one subpad. As shown in FIG. 1, the first subpad 50_1 and the second subpad 50_2 can be included. The first subpad 50_1 can electrically connect the first subpattern 15_1 and the first subtest pattern 40_1, and the second subpad 50_2 electrically connects the second subpattern 15_2 and the second subtest pattern 40_2. Can be connected.

The plurality of first connection pads 50 can be arranged apart from each other at a certain distance to form the first connection pad group 51. The plurality of first connection pads 50 can be arranged side by side in the second direction d2, for example, as shown in FIG. On the other hand, the first connection pads 50 arranged side by side in the second direction d2 can be arranged so as not to overlap with the first direction d1 but at least a part thereof overlap with the third direction d3.

Such an arrangement is for minimizing the area required for the arrangement of the first connection pad 50 when the first wiring pattern 15 and the first test pattern 40 are arranged so as to extend in the third direction d3, respectively. Although it may be an example of the arrangement of the first connection pad 50, the present invention is not limited thereto.

That is, when the first wiring pattern 15 and the first test pattern 40 are arranged so as to extend in the first direction d1, at least a part of the first connection pad 50 is superimposed on the first direction d1 and the first direction pad 50 is overlapped with the first direction d1. It may be arranged so as not to overlap with d3.

Similar to the first wiring pattern 15, the first connection pad 50 can contain a substance having electrical conductivity such as copper, gold, or an alloy thereof.

The second wiring pattern 16 can be formed on the other surface of the base substrate 10. That is, the second wiring pattern 16 can be formed on the opposite surface of the first wiring pattern 15 and the base substrate 10. Similar to the first wiring pattern 15, the second wiring pattern 16 may be a plurality of wiring patterns arranged apart from each other with a constant width and interval on the other surface of the base substrate 10.

The second wiring pattern 16 can be electrically connected to the second connection pad 30. That is, as shown in FIG. 2, the second wiring pattern 16 extends on the other surface of the base substrate 10 and can be connected to the second connection pad 30. The second wiring pattern 16 can be electrically connected to the second test pattern 20 via the second connection pad 30. Like the first wiring pattern 15, the second wiring pattern 16 may be made of a material having electrical conductivity such as copper, gold, and aluminum.

The second connection pad 30 can include an upper pad 36 and a lower pad 37. The upper pad 36 may be connected to a second test pattern 20 formed on one surface of the base substrate 10, and the lower pad 37 may be connected to a second wiring pattern 16 formed on the other surface of the base substrate 10.

At least a portion of the upper pad 36 can be overlaid perpendicular to the lower pad 37. On the other hand, the upper pad 36 and the lower pad 37 can be connected via the via 41. The second connection pad 30 can be arranged so as to be vertically superimposed on the via 41. For each of the plurality of second connection pads 30 arranged apart from each other in the second direction d2, the vias 41 penetrating the base substrate 10 can be arranged so as to overlap each other with the plurality of second connection pads 30.

The via 41 fills the via hole 45 penetrating the base substrate 10 and can electrically connect the upper pad 36 and the lower pad 37. For example, FIG. 2 shows that the via 41 that fills the via hole 45 is composed of a single layer, but the via 41 has two or more layers in which a metal foil layer is formed on the inner side wall of the via hole 45. It may be formed in a structure.

The plurality of second connection pads 30 are spaced apart from each other on one surface of the base substrate 10 at regular intervals, and the second connection pad group 31 can be formed. The plurality of second connection pads 30 can be arranged side by side in the second direction d2, for example. The plurality of second connection pads 30 can be arranged so as not to overlap with the first direction d1 but at least a part thereof overlap with the third direction d3.

In such an arrangement, when the second test pattern 20 is arranged so as to extend in the third direction d3, the arrangement of the second connection pad 30 for minimizing the area required for the arrangement of the second connection pad 30 is performed. However, the present invention is not limited.

Similar to the above, when the second test pattern 20 is arranged so as to extend in the first direction d1, the second connection pad 30 is at least in the first direction d1 in order to optimize the arrangement area. It can be arranged so that a part thereof overlaps and does not overlap in the third direction d3.

Like the first connection pad 50, the second connection pad 30 can contain a substance having electrical conductivity such as copper, gold or an alloy thereof.

The second connection pad 30 is connected to the second wiring pattern 16 on the other surface of the base board 10 by connecting the second wiring pattern 16 on the other surface of the base board 10 to the second test pattern 20 on the one surface. The circuit element can be electrically connected to the second test pattern 20. Therefore, the opening / short-circuit test of the circuit element or the second wiring pattern 16 arranged on the other surface of the base substrate 10 can be performed using the second test pattern 20.

The first test pattern 40 can extend over the first test region 35 on one surface of the base substrate 10. The first test pattern 40 can extend between the first connection pad 50 and the second connection pad 30.

FIG. 3 is a diagram showing the arrangement of test patterns in the test area of the flexible circuit board according to the embodiment of the present invention.

Within the first test area 35, the first test pattern 40 can extend at a predetermined angle with the extension direction d1 of the first test area 35.

For example, the first test pattern 40 can form an angle of 45 to 135 degrees with respect to the extension direction d1 of the first test region 35. In FIG. 3, the first test region 35 can be divided into a portion 40_1a forming 45 degrees with the extension direction d1 of the first test region 35 and a portion 40_1b forming 90 degrees.

That is, in the flexible circuit board 1 according to the embodiment of the present invention, the first test area 35 or the second test area 25 is an area where probe scanning is performed in order to perform an opening / short-circuit test of a circuit element or a wiring pattern. The extension direction d1 of the first test area 35 or the second test area 25 may be the direction in which the probe advances in the open / short circuit test. Therefore, when the first or second test patterns 40, 20 form a predetermined angle with the extension direction d1 of the first or second test regions 35, 25, the first or second test patterns 40, 20 are relative to the first or second test patterns 40, 20. Probe scanning can be performed at the above angles.

At this time, if the angle formed by the extension direction d1 of the first or second test regions 35 and 25 and the first or second test patterns 40 and 20 is smaller than 45 degrees, the probe and the first or second test are performed. Since the angle at which the patterns 40 and 20 intersect is smaller than 45 degrees, the open / short circuit test may not be performed correctly.

On the other hand, in some embodiments of the present invention, the width w of the first or second test regions 35, 25 can be 100 μm or more. That is, the width w in the extension direction of the test region (d1 in FIG. 3) can be 100 μm or more. This means that probe scanning is performed with a wide margin of 100 μm or more in the open / short circuit test for the first or second test patterns 40, 20.

In the flexible circuit board 1 according to the embodiment of the present invention, the first test area 35 can be arranged between the first connection pad 50 and the second connection pad 30, and the second test area 25 is the base board 10. It can be arranged between the end portion and the second connection pad 30.

As another embodiment of the present invention, a sprocket hole for winding the base substrate 10 in a roll-to-roll process is provided at an end portion of the base substrate 10, and a second test region 25 is a sprocket hole (FIG. Can be placed between (not shown) and the second connection pad 30.

The flexible circuit board 1 according to the embodiment of the present invention does not include a test pad for confirming whether or not the wiring patterns 15 and 16 formed on the base board 10 are short-circuited / opened.

Therefore, instead of another test pad, test patterns 20 and 40 extending over the test areas 25 and 35 of the base board 10 on which the probe scanning test is performed are provided, so that the area of the base board 10 can be reduced to reduce the flexible circuit. It may be advantageous to the substrate 1.

Further, the probe scanning tests for the probes of the wiring patterns 15 and 16 on both sides of the base substrate 10 are simultaneously performed by the test patterns 20 and 40 for electrically connecting the wiring patterns 15 and 16 on both sides of the base substrate 10. It can be done.

FIG. 4 is a diagram of a flexible circuit board according to another embodiment of the present invention. Hereinafter, the configuration overlapping with the previous embodiment will be omitted, and the differences will be mainly described.

Referring to FIG. 4, in the flexible circuit board 2 according to another embodiment of the present invention, the first test region 35 and the second test region 25 may be arranged adjacent to each other.

In the flexible circuit board 1 described above with reference to FIG. 1, the second test pattern 20 extends in the direction toward the end of the base board 10, that is, in the outer direction of the base board 10. The flexible circuit board 2 according to the embodiment can include a second test pattern 20 extending inward of the base board 10.

The first test pattern 40 and the second test pattern can extend between the first connection pad 50 and the second connection pad 30. Therefore, the first and second test areas 35 and 25 can also be arranged apart from each other with a predetermined interval between the first connection pad 50 and the second connection pad 30.

As another embodiment of the present invention, the first and second test areas 35 and 25 are integrated into one test area, and the first and second test patterns 40 and 20 are probe scanning directions in the integrated test area. It is also possible to reduce the area of the test area by arranging them so as to intersect with each other.

FIG. 5 is a top view of a flexible circuit board according to another embodiment of the present invention.

Referring to FIG. 5, the flexible circuit board 3 according to another embodiment of the present invention can include a first connection pad 50 and a second connection pad 30 arranged adjacent to each other. That is, a first connection pad group 51 in which a plurality of first connection pads are arranged in the second direction d2 and a second connection in which a plurality of second connection pads 30 are arranged in the second direction d2. The pad groups 31 can be arranged adjacent to each other.

As shown in FIG. 5, the first connection pad group 51 including the plurality of first connection pads 50 and the second connection pad group 31 including the plurality of second connection pads 30 can be arranged side by side in the second direction d2. However, the present invention is not limited to this. That is, the first connection pad group 51 and the second connection pad group 31 are arranged between the first test area 35 and the second test area 25, and the first and second connection pad groups 51 and 31 are in the first direction d1. Any number of embodiments are possible in which they are arranged side by side.

As another embodiment of the present invention, the first connection pad 50 may not include the first test pattern 40. In this case, a part of the area can be selected from the first wiring pattern 15 connected to the first test pattern 40 and set as the first test area 35, and the probe scanning test can be performed. In this case, the area of the first test pattern 40 can be reduced, which has the effect of reducing the size of the product.

1, 2, 3 Flexible circuit board 10 Base board 20, 40 Test pattern 30, 50 Connection pad 25, 35 Test area 45 Via 150 Resist layer 160 Protective film

Claims (5)

A base board with a test area defined on one side ,
Before SL based at least one first connection pad first is the wiring pattern electrically connected respectively formed on said one surface of the substrate,
Includes at least one second connection pad that is disposed on the one surface of the base substrate and is electrically connected to a second wiring pattern formed on the other surface that is the opposite surface of the one surface of the base substrate. ,
The first test pattern extending from the front Symbol first connection pads on the test area, and includes a second test pattern which extends over the test area from the second connecting pad,
The test area includes a first test area in which the first test pattern is arranged and a second test area in which the second test pattern is arranged.
Wherein the first test region is disposed between the second connecting pad and the first connection pads, are pre-Symbol second test region is disposed between the end portion and the front Stories second connection pads of the base substrate Flexible circuit board. The flexible circuit board according to claim 1, wherein the first test pattern and the second test pattern are arranged in the test area so as to intersect the scanning direction of the probe. The flexible circuit board according to claim 1, wherein the test area is arranged outside the first connection pad or the second connection pad. The flexible circuit board according to claim 1, wherein the first test pattern and the second test pattern form 45 to 135 degrees with respect to the probe scanning traveling direction. The flexible circuit board according to claim 1, wherein the second connection pad is electrically connected to the second wiring pattern and vertically overlaps with a via penetrating the base board.

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