阅读说明：本技术 可伸缩电路基板 (Telescopic circuit substrate ) 是由 朴德勋 张祐荣 白智钦 于 2020-02-26 设计创作，主要内容包括：根据实施方式的可伸缩电路板包括：基板,其包括一个表面和与该一个表面相对的另一表面；电子部件,其被布置在基板的一个表面上；以及布线电极,其被布置在基板的一个表面上并且连接电子部件,其中,基板包括其中形成有电子部件的有效区域和除有效区域之外的无效区域,并且包括图案部分,图案部分形成在无效区域中并且从基板的一个表面穿过基板延伸到基板的另一表面。(The retractable circuit board according to an embodiment includes: a substrate including one surface and another surface opposite to the one surface; an electronic component disposed on one surface of the substrate; and a wiring electrode arranged on one surface of the substrate and connecting the electronic component, wherein the substrate includes an effective region in which the electronic component is formed and an ineffective region other than the effective region, and includes a pattern portion formed in the ineffective region and extending from one surface of the substrate to the other surface of the substrate through the substrate.)

1. A retractable circuit board comprising:

a substrate including one surface and another surface opposite to the one surface;

an electronic component disposed on the one surface of the substrate; and

a wiring electrode arranged on the one surface of the substrate and connecting the electronic component,

wherein the substrate includes an active area in which the electronic component is formed and an inactive area other than the active area,

the substrate is formed with a pattern portion passing through the one surface and the other surface of the substrate,

the pattern portion is formed in the ineffective area.

2. The retractable circuit board of claim 1, wherein the hole extends in a direction perpendicular to a longitudinal direction in which the wiring electrode extends.

3. The retractable circuit board of claim 2, wherein the substrate is stretched in one direction, and

the holes extend in a direction perpendicular to a stretching direction of the substrate.

4. The retractable circuit board of claim 1, wherein the length of the routing electrodes is longer than the distance between the elements.

5. The retractable circuit board of claim 4, wherein the routing electrode comprises a bend.

6. The retractable circuit board of claim 4, wherein the substrate is stretched in one direction,

the wiring electrode includes a plurality of peaks and valleys between the peaks, and

when the interval between adjacent peaks before the stretching of the substrate is defined as Y and the interval between adjacent peaks after the stretching of the substrate is defined as Y',

the size of Y' is greater than 1 time and less than or equal to 1.5 times the size of Y.

7. The retractable circuit board of claim 1, wherein the routing electrodes are disposed on the inactive area.

8. The stretchable circuit board according to claim 1, wherein a long width of the pattern portion extends in a direction perpendicular to a longitudinal direction of the wiring electrode.

9. A flexible display device comprising:

a support substrate; and

a panel including at least one of a display panel and a touch panel disposed on the support substrate,

wherein the panel comprises a stretchable circuit board, and

the retractable circuit board includes:

a substrate including one surface and another surface opposite to the one surface;

an electronic component disposed on the one surface of the substrate; and

a wiring electrode arranged on the one surface of the substrate and connecting the electronic component,

wherein the substrate includes an active area in which the electronic component is formed and an inactive area other than the active area,

the substrate is formed with a pattern part passing through the one surface and the other surface of the substrate,

the pattern portion is formed in the ineffective area.

10. The flexible display device of claim 9, wherein the support substrate and the panel are curved in one direction, and

the stretchable circuit board is bent in the same direction as the one direction.

Technical Field

Embodiments relate to a stretchable circuit board.

Background

Recently, there is an increasing demand for a flexible display device that can easily carry various applications and can display an image on a larger screen when being carried.

Such flexible displays fold or partially bend when carried or stored, and may be implemented to unfold the display when displaying an image. Therefore, an image display area can be increased, and a user can easily carry the display.

After the flexible display device is folded or bent, a recovery process of unfolding the flexible display device again may be repeated.

Meanwhile, in order to implement various operations of the display, the flexible device includes various electronic components such as an ASIC, a driving chip, and a multilayer ceramic capacitor (MLCC), and a circuit board on which a plurality of wirings connecting the electronic components are formed.

In the case of such a circuit board, stress generated when the flexible display device is folded or bent or stretched or restored in one direction affects a soldering area or a bonding area of the circuit board, and electronic parts bonded to the circuit board are delaminated, and thus reliability of the flexible display device may be reduced.

Therefore, there is a need for a stretchable circuit board having a new structure in which electronic parts formed on the circuit board do not come off the film when bent or folded.

Disclosure of Invention

[ problem ] to

Embodiments relate to a stretchable circuit board capable of preventing a release of an electronic component bonded to the circuit board.

[ solution ]

A stretchable circuit board according to an embodiment includes: a substrate including one surface and another surface opposite to the one surface; an electronic component disposed on one surface of the substrate; and a wiring electrode disposed on one surface of the substrate and connecting the electronic component, wherein the substrate includes an effective region in which the electronic component is formed and an ineffective region other than the effective region, the substrate is formed with a pattern portion passing through the one surface and the other surface of the substrate, and the pattern portion is formed in the ineffective region.

[ advantageous effects ]

In the stretchable circuit board according to the embodiment, it is possible to prevent the adhesiveness of the electronic components of the circuit board from being deteriorated when the circuit board is stretched in one direction.

That is, when the circuit board is stretched in one direction, the pattern portions formed in the ineffective area of the substrate are stretched together to prevent the effective area from being stretched, and thus the adhesive member disposed on the effective area can be prevented from being peeled off due to the stretching.

Accordingly, the circuit board according to the embodiment may improve reliability of the circuit board and the display device including the same by preventing deterioration of adhesiveness of electronic parts.

In addition, by forming the wiring electrode connecting the electronic component into a curved shape including peaks and valleys, when the substrate is stretched and recovered, the wiring electrode can also be stretched and recovered, and thus the wiring electrode on the ineffective area can be prevented from being damaged or deformed due to the stretching.

Drawings

Fig. 1 is a view illustrating a perspective view of a flexible display device according to an embodiment.

Fig. 2 and 3 are views showing sectional views of the circuit board before and after stretching according to the embodiment.

Fig. 4 to 6 are views showing top views for describing modified examples of the circuit board according to the first embodiment.

Fig. 7 to 9 are plan views showing electronic components and wiring electrodes arranged on the circuit board according to the first embodiment.

Fig. 10 to 12 are enlarged views showing wiring electrodes arranged on the circuit board according to the first embodiment.

Fig. 13 to 15 are views showing a top view for describing a modified example of the circuit board according to the second embodiment.

Fig. 16 to 18 are views showing a top view for describing electronic components and wiring electrodes arranged on the circuit board according to the second embodiment.

Fig. 19 and 20 are views showing an application example of a flexible display device to which a circuit board according to an embodiment is applied.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the spirit and scope of the present invention are not limited to a part of the described embodiments, and may be embodied in various other forms, and one or more elements of the embodiments may be selectively combined and substituted within the spirit and scope of the present invention.

In addition, unless otherwise explicitly defined and described, terms (including technical and scientific terms) used in embodiments of the present invention may be construed as having the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs, and terms such as those defined in commonly used dictionaries may be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art.

In addition, terms used in the embodiments of the present invention are used to describe the embodiments, and are not intended to limit the present invention. In this specification, the singular form may also include the plural form unless specifically stated in the phrase, and when described as "at least one (or more) of a (and), B, and C" may include at least one of all combinations that may be combined in A, B and C.

In addition, in describing the elements of the embodiments of the present invention, terms such as first, second, A, B, (A) and (b) may be used.

In addition, when an element is described as being "connected," coupled, "or" connected "to another element, it may include not only when the element is directly" connected, "coupled," or "connected" to the other element, but also when the element is "connected," "coupled," or "connected" to the other element through another element between the element and the other element.

Further, when it is described that each element is formed or arranged "on (above)" or "under (below)", the "on (above)" or "under (below)" may include not only when two elements are directly connected to each other but also when one or more other elements are formed or arranged between the two elements.

Further, when it is expressed as "upper (upper)" or "lower (lower)", it may include not only an upper direction based on one element but also a lower direction based on one element.

Hereinafter, a stretchable circuit board according to an embodiment will be described with reference to the accompanying drawings.

Fig. 1 is a view illustrating a perspective view of a flexible display device according to an embodiment.

Referring to fig. 1, a flexible display device 1000 according to an embodiment may include a support substrate 1100, a display panel 1200 disposed on the support substrate 1100, and a touch panel 1300 disposed on the display panel 1200.

The support substrate 1100 may support the display panel 1200 and the touch panel 1300. That is, the support substrate 1100 may be a substrate that supports the display panel 1200 and the touch panel 1300.

The support substrate 1100 may include a material such as metal. For example, support substrate 1100 may comprise a metal, metal alloy, plastic, composite material (e.g., carbon fiber reinforced plastic, magnetic or conductive material, glass fiber reinforced material, etc.), ceramic, sapphire, glass, or the like.

The support substrate 1100 may be flexible. That is, the support substrate 1100 may be folded or bent in one direction. That is, the support substrate 1100 may be a substrate for a display applied to a flexible display device.

The display panel 1200 may be disposed over the support substrate 1100.

The display panel 1200 may include a plurality of pixels including a switching thin film transistor, a driving thin film transistor, a power storage device, and an Organic Light Emitting Diode (OLED). In the case of the OLED, deposition may be performed at a relatively low temperature, and the OLED may be mainly applied to a flexible display device for reasons such as low power and high brightness. Here, the pixel refers to a minimum unit for displaying an image, and the display panel displays an image by a plurality of pixels.

The display panel may include a substrate, a gate line disposed on the substrate, a data line isolated from the gate line, and a common power line. In general, one pixel may be defined by a gate line, a data line, and a common power line as boundaries.

The substrate may include a material having a flexible characteristic, such as a plastic film, and the display panel 1200 may be implemented by disposing the organic light emitting diodes and the pixel circuits on the flexible film.

The touch panel 1300 may be disposed over the display panel 1200. The touch panel 1300 may implement a touch function in a flexible display device, and may omit the touch panel in a flexible display device that displays only an image without the touch function.

The touch panel 1300 may include a substrate and touch electrodes disposed on the substrate. The touch electrode may sense a position of the input device touched on the flexible display device using a capacitive type or a resistive film type.

The substrate of the touch panel 1300 may include a material having a flexible property, for example, a plastic film, and the touch panel 1300 may be implemented by disposing a touch electrode on the flexible film.

Meanwhile, although not shown in the drawings, a cover window protecting the flexible display device may be additionally disposed over the touch panel 1300 or over the display panel 1200 (when the touch panel is omitted).

The stretchable circuit board according to the embodiment may be disposed inside the display panel or the touch panel. In detail, the stretchable circuit board may include an element for driving the display panel or an electronic component for driving the touch panel and a plurality of wiring electrodes.

The stretchable circuit board described below is applied to a flexible display device and has a structure capable of preventing wires or elements formed on the stretchable circuit board from being peeled off, the stretchable circuit board being stretched and restored together when the display device is bent or folded.

Fig. 2 and 3 are views illustrating a cross-sectional view of a stretchable circuit board according to an embodiment.

Referring to fig. 2, the stretchable circuit board according to the embodiment may include a substrate 100, an electronic component 200 disposed on the substrate, and a wiring electrode 300 electrically connecting the electronic component 200.

The substrate 100 may be flexible. For example, the substrate 100 may include plastic. In detail, the substrate 100 may include plastic such as Polyimide (PI), polyethylene terephthalate (PET), propylene glycol (PPG) Polycarbonate (PC), and the like.

In addition, the substrate 100 may include an optically isotropic film. For example, the substrate 100 may include Cyclic Olefin Copolymer (COC), Cyclic Olefin Polymer (COP), optically isotropic Polycarbonate (PC), optically isotropic Polymethylmethacrylate (PMMA), and the like.

In addition, the substrate 100 may be partially bent when having a curved surface. That is, the substrate 100 may partially have a flat surface and may partially be curved when having a curved surface. In detail, the end portion of the substrate 100 may be bent when having a curved surface, or may be bent or twisted when having a surface with a random curvature.

Further, the substrate 100 may be a flexible substrate having flexibility. Further, the substrate 100 may be a bent or bent substrate.

The substrate 100 may include an active area AA and an inactive area UA. In detail, the substrate 100 may include an effective area AA defined as an area in which the electronic component 200 is disposed and an ineffective area UA defined as an area other than the effective area AA, for example, an area in which no electronic component is disposed. The wiring electrode 300 may be disposed on the inactive area UA.

The electronic component 200 may be disposed on the substrate 100. The electronic component 200 may be disposed on the upper surface of the substrate 100. In detail, the electronic component 200 may be disposed on at least one surface of the substrate 100.

The electronic components 200 may include elements and/or chips that drive the display panel or the touch panel.

For example, the electronic components may include active devices or passive devices. An active device refers to a device that actively uses a nonlinear characteristic, and a passive device refers to a device that does not use a nonlinear characteristic even if both the linear characteristic and the nonlinear characteristic exist. The active devices may include transistors, IC semiconductor chips, etc., and the passive devices may include capacitors, resistors, inductors, etc. The passive device is mounted on the substrate together with a general semiconductor package to improve a signal processing speed of a semiconductor chip as an active device, perform a filtering function, and the like.

The electronic component 200 may be adhered to one surface of the substrate 100. In detail, the adhesive member 150 is disposed on the substrate 100, and the electronic component 200 may be bonded to one surface of the substrate 100 by the adhesive member 150.

The adhesive member 150 may include solder paste. The solder paste is an adhesive that fixes the electronic component 200 attached to the substrate 100.

The adhesive member 150 may include a conductive adhesive or a non-conductive adhesive. The conductive adhesive is mainly classified into an anisotropic conductive adhesive and an isotropic conductive adhesive, and basically consists of conductive particles such as Ni, Au/polymer or Ag and a thermosetting resin and a thermoplastic resin or a blend type insulating resin mixing the characteristics of both resins.

In addition, the nonconductive adhesive may also be a polymer adhesive, and may preferably be a nonconductive polymer adhesive including a thermosetting resin, a thermoplastic resin, a filler, a curing agent, and a curing accelerator.

The wiring electrode 300 may be disposed on the substrate 100. The wiring electrode 300 may be disposed on the upper surface of the substrate 100. In detail, the wiring electrode 300 may be disposed on one surface of the substrate 100.

The wiring electrode 300 may be disposed in an inactive area UA among areas of the substrate 100.

The wiring electrode 300 may electrically connect the electronic component 200 disposed on one surface of the substrate 100. For example, the wiring electrode 300 may electrically connect a plurality of devices and/or chips to each other. In detail, the wiring electrode 300 may be connected to each of the electronic components 200 through the pad portion 350 so that a plurality of electronic components may be electrically connected to each other.

The wiring electrode 300 may be a wiring that transmits an electrical signal and may be formed of a metal material having high conductivity. For this, the wiring electrode 300 may be formed of at least one metal material selected from among gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), copper (Cu), and zinc (Zn). In addition, the wiring electrode 300 may be formed of a paste or solder paste including at least one metal material selected from gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), copper (Cu), and zinc (Zn), which have excellent bonding strength. Preferably, the wiring electrode 300 may be formed of copper (Cu) having high conductivity and relatively low cost.

Meanwhile, such a stretchable circuit board may be applied to a flexible display device, and may be stretched in one direction when the stretchable circuit board is also bent or folded, and simultaneously stretched in one direction when the flexible display device is bent or folded.

Referring to fig. 3, the stretchable circuit board may be stretched while being bent in one direction. That is, the stretchable circuit board may be stretched in the same direction as the flexible display device is bent and stretched.

In this case, when the substrate 100 is stretched, a tensile stress may be generated in the substrate. The adhesive member 150 disposed on the substrate 100 may be delaminated from the substrate 100 due to stress.

Accordingly, the adhesiveness of the electronic component 200 adhered by the adhesive member 150 may be deteriorated, and thus the reliability of the circuit board and the flexible display device including the same may be reduced.

Accordingly, a plurality of pattern portions P may be formed on the substrate 100. In detail, a plurality of pattern portions P may be formed in the inactive area UA of the substrate 100. Stress generated when the substrate is stretched is relieved by the pattern portion P, and thus, the adhesive member 150 can be prevented from being peeled.

Meanwhile, fig. 3 illustrates that the stretchable circuit board is bent such that surfaces on which the adhesive members are not disposed face each other, but the embodiment is not limited thereto, but the stretchable circuit board is bent such that surfaces on which the adhesive members are disposed face each other, and thus, the adhesive member 150 may be delaminated from the substrate 100 due to a shrinkage stress.

Hereinafter, the pattern part P formed on the substrate 100 will be described in detail, focusing on the fact that the stretchable circuit board is bent such that the surfaces on which the adhesive members are not disposed face each other.

Fig. 4 to 6 are views showing a top view for describing a modified example of the stretchable circuit board according to the first embodiment.

Fig. 4 is a view showing a substrate of the stretchable circuit board before stretching, fig. 5 is a view showing a substrate of the stretchable circuit board after stretching, and fig. 6 is a view showing a substrate of the stretchable circuit board after recovery.

Referring to fig. 4, the substrate 100 may include a plurality of pattern portions P. The pattern portion P may be formed in a region on which the electronic component 200 is not arranged, that is, in the inactive region UA of the substrate.

In addition, the pattern portion P is not formed in the effective area AA of the substrate on which the electronic component 200 is arranged.

The pattern portion P may be formed in the entire area of the inactive area UA of the substrate 100 or in a partial area of the inactive area UA.

The pattern portion P may be a hole formed through the substrate 100. In detail, the pattern portion P may be formed to pass through one surface and the other surface of the substrate 100.

The pattern portion P formed to pass through one surface and the other surface of the substrate 100 may be formed to extend in one direction. In detail, the pattern portion P may be formed to extend in a direction different from the direction in which the wiring electrode 300 extends. In detail, the pattern portion P may extend in a direction perpendicular to a direction in which the wiring electrode 300 extends. That is, the pattern portion P may be formed to extend in a direction perpendicular to the longitudinal direction of the wiring electrode 300.

In addition, the pattern portion P may be formed to extend in the width direction of the substrate 100. In detail, the substrate 100 may have a long width having a length in a long side direction and a short width having a length in a short side direction. The pattern portion P may be formed to extend in a short width direction having a length in a short side direction of the substrate.

In addition, the pattern portion P may be formed to extend in a direction perpendicular to the stretching direction of the substrate 100. That is, when the substrate 100 is stretched in one direction, the pattern portion P may be formed to extend in a direction perpendicular to the one direction.

That is, the pattern portion P may have a long width and a short width, and the long width may extend in a direction perpendicular to a longitudinal direction of the wiring electrode, a long side direction of the substrate, or a direction in which the substrate is stretched.

The pattern part P may be formed to have a curved surface. In detail, the pattern part P may be formed in a shape having a curved surface, such as an elliptical shape, a hemispherical shape, a circular shape, or the like.

However, the embodiment is not limited thereto, and the pattern portion P may be formed in a polygonal shape, for example, a triangle, a square, or the like.

Fig. 5 and 6, the substrate 100 may be recovered after being stretched in one direction.

For example, referring to fig. 5, the substrate 100 may be stretched in a longitudinal direction of the substrate 100. When the substrate 100 is stretched in one direction, the size of the pattern part P may be changed. In detail, when the substrate 100 is stretched in one direction, the size of the short width of the pattern part P may be increased as much as the substrate is stretched.

Referring to fig. 6, when the substrate 100 is restored, the short width of the pattern portion P may also be restored.

That is, the size of the short width of the pattern portion P formed in the inactive area UA of the substrate may be increased in the stretching direction and then restored.

Therefore, when the substrate 100 is stretched in one direction, the occurrence of tensile stress in the effective area AA of the substrate in which the electronic component 200 is arranged may be minimized. That is, when the pattern portion P formed in the inactive area AA of the substrate serves as a spring and the substrate 100 is stretched in one direction, the pattern portion may be stretched in the same direction as the stretching direction.

Therefore, when the substrate 100 is stretched in one direction as shown in fig. 5, only the ineffective area of the substrate is stretched, and the effective area of the substrate can be prevented from being stretched, and thus the adhesive member disposed on the effective area of the substrate can be prevented from being peeled.

Accordingly, when the substrate 100 is stretched, it is possible to prevent deterioration of the adhesiveness of the electronic parts due to the release of the adhesive member, thereby improving the reliability of the circuit board and the display device including the same.

Hereinafter, the electronic components and the wiring electrodes arranged on the substrate 100 on which the pattern portion is formed will be described in detail.

Fig. 7 to 9 are views showing electronic components and wiring electrodes arranged on the stretchable circuit board according to the above-described first embodiment.

Fig. 7 is a view showing the stretchable circuit board before stretching, fig. 8 is a view showing the stretchable circuit board after stretching, and fig. 9 is a view showing the stretchable circuit board after recovery.

Referring to fig. 7, the electronic component 200 may be disposed on the active area AA of the substrate 100, and the wiring electrode 300 may be formed on the inactive area UA of the substrate.

That is, the electronic component 200 may be disposed on the effective area AA of the substrate 100 in which the pattern portion P is not formed, and the wiring electrode 300 may be formed on the ineffective area UA of the substrate in which the pattern portion P is formed.

Referring to fig. 8 and 9, as described above, the effective area AA of the substrate 100 on which the electronic component 200 is disposed may be prevented from being drawn together when the substrate 100 is drawn, and the ineffective area UA of the substrate 100 on which the wiring electrode 300 is disposed may be drawn together as much as the substrate is drawn when the substrate 100 is drawn.

Accordingly, in the effective area AA of the substrate 100 on which the electronic component 200 is disposed, the adhesive member adhered to the substrate 100 and the electronic component 200 may be prevented from being peeled off, and thus, even when the substrate 100 is stretched and recovered, the adhesiveness between the substrate 100 and the electronic component 200 may be maintained.

Fig. 10 to 12 are enlarged views showing wiring electrodes arranged on the circuit board according to the first embodiment.

Fig. 10 is a view showing the wiring electrode before stretching, fig. 11 is a view showing the wiring electrode after stretching, and fig. 12 is a view showing the wiring electrode after recovery.

Referring to fig. 10, the wiring electrode 300 disposed on the inactive area UA of the substrate 100 may be disposed on the substrate 100 to electrically connect at least two or more electronic components 200.

The length of the wiring electrode 300 may be greater than the distance D between the electronic components 200 connected to the wiring electrode 300.

The wiring electrode 300 may have a curved shape. That is, a plurality of peak regions PA and valley regions TA between the peak regions may be included between one end and the other end of the wiring electrode.

In addition, the peak regions and the valley regions may be alternately arranged. Therefore, the length of the wiring electrode 300 may be greater than the distance D between the electronic components 200 connected to the wiring electrode 300.

Referring to fig. 11 and 12, when the substrate 100 is stretched in one direction, the wiring electrode 300 may also be stretched. In addition, when the substrate 100 is recovered, the wiring electrode 300 may also be recovered.

In the wiring electrode, when the substrate 100 is stretched in one direction, the pitch P1 in the peak region and the pitch P2 in the valley region of the wiring electrode may change.

For example, when a distance D1 between the electronic components 200 before the substrate is stretched is defined as X and a distance D2 between the electronic components 200 after the substrate is stretched is defined as X ', the size of X' may be increased as much as the substrate is stretched with respect to the size of X.

In this case, the pitch P1 of the peak region and the pitch P2 of the valley region of the wiring electrode may also be increased. In detail, when a pitch P1 of adjacent peak regions and a pitch P2 of adjacent valley regions before the substrate is stretched are defined as Y and a pitch P1 of adjacent peak regions and a pitch P2 of adjacent valley regions after the substrate is stretched are defined as Y ', the size of Y' may be greater than the size of Y.

In detail, the size of Y' may be greater than 1 time and less than or equal to 1.5 times the size of Y. When the size of Y' is equal to or less than 1 times the size of Y, the wiring electrodes are not stretched together when the substrate is stretched and recovered, and thus it may be deformed or damaged by the tensile stress. In addition, when the size of Y' is greater than 1.5 times the size of Y, the size of the wiring electrode after the substrate 100 is recovered is different from the size of the wiring electrode before the substrate 100 is stretched, and thus the stretching force of the wiring electrode may be reduced when the substrate is repeatedly stretched.

Accordingly, when the pitch P1 of the peak region and the pitch P2 of the valley region of the wiring electrode were the Y value before the stretching and the pitch was changed to the Y' value after the stretching, the pitch was restored to the Y value after the restoration.

In the stretchable circuit board according to the embodiment, it is possible to prevent the adhesiveness of the electronic components of the circuit board from being deteriorated when the circuit board is stretched in one direction.

That is, when the circuit board is stretched in one direction, the pattern portions formed in the ineffective area of the substrate are stretched together to prevent the effective area from being stretched, and thus the adhesive member disposed on the effective area can be prevented from being peeled off due to the stretching.

Accordingly, the circuit board according to the embodiment may improve reliability of the circuit board and the display device including the same by preventing deterioration of adhesiveness of electronic parts.

In addition, when the substrate is stretched and recovered, by forming the wiring electrode connecting the electronic component into a curved shape including peaks and valleys, the wiring electrode can also be stretched and recovered, and thus the wiring electrode on the ineffective area can be prevented from being damaged or deformed due to the stretching.

Hereinafter, a substrate and a circuit board according to a second embodiment will be described with reference to fig. 13 to 18.

Fig. 13 to 15 are views showing a top view for describing a modified example of the stretchable circuit board according to the second embodiment.

Fig. 13 is a view showing a substrate of the stretchable circuit board before stretching, fig. 14 is a view showing a substrate of the stretchable circuit board after stretching, and fig. 15 is a view showing a substrate of the stretchable circuit board after recovery.

Referring to fig. 13, the substrate 100 may include a plurality of pattern portions P. The pattern portion P may be formed in a region where the electronic component 200 is not disposed, that is, in the inactive region UA of the substrate.

In addition, the pattern portion P is not formed in the effective area AA of the substrate in which the electronic component 200 is arranged.

The pattern portion P may be a hole formed through the substrate 100. In detail, the pattern portion P may be formed to pass through one surface and the other surface of the substrate 100.

The pattern portion P formed to pass through one surface and the other surface of the substrate 100 may be formed in a polygonal shape. For example, the pattern portion P may be formed in a honeycomb shape.

Referring to fig. 14 and 15, the substrate 100 may be recovered after being stretched in a plurality of directions.

For example, referring to fig. 14, the substrate 100 may be stretched in one direction and another direction. For example, the substrate 100 may include a first corner region, a second corner region, a third corner region, and a fourth corner region, and the substrate may be stretched in a direction parallel to the first corner region and the fourth corner region facing each other, and the substrate may be stretched in a direction parallel to the second corner region and the third corner region facing each other.

That is, the substrate 100 may be stretched in at least two directions having different directions.

As the substrate 100 is stretched in one direction and the other direction, the size of the pattern part P may be changed. In detail, as the substrate 100 is stretched in one direction and the other direction, the pattern part P may maintain a honeycomb shape and its size may increase.

Referring to fig. 15, when the substrate 100 is restored, the size of the pattern portion P may also be restored.

That is, the size of the pattern portion P formed in the inactive area UA of the substrate may be increased in a plurality of stretching directions and then restored.

Therefore, when the substrate 100 is stretched in one direction and the other direction, the occurrence of tensile stress in the effective area AA of the substrate in which the electronic component 200 is arranged may be minimized. That is, when the pattern portion P formed in the inactive area UA of the substrate serves as a spring and the substrate 100 is stretched in one direction and the other direction, the pattern portion P may be stretched in the same direction as the stretching direction.

Therefore, when the substrate 100 is stretched in one direction and the other direction as shown in fig. 14, only the ineffective area of the substrate is stretched, and the effective area of the substrate can be prevented from being stretched, and thus the adhesive member disposed on the effective area of the substrate can be prevented from being peeled.

Accordingly, when the substrate 100 is stretched, it is possible to prevent deterioration of the adhesiveness of the electronic parts due to the release of the adhesive member, thereby improving the reliability of the circuit board and the display device including the same.

Hereinafter, the electronic components and the wiring electrodes disposed on the substrate 100 on which the pattern portion is formed will be described in detail.

Fig. 16 to 18 are views showing electronic components and wiring electrodes arranged on the stretchable circuit board according to the above-described second embodiment.

Fig. 16 is a view showing the stretchable circuit board before stretching, fig. 17 is a view showing the stretchable circuit board after stretching, and fig. 18 is a view showing the stretchable circuit board after recovery.

Referring to fig. 16, the electronic component 200 is disposed on the active area AA of the substrate 100, and the wiring electrode 300 may be formed on the inactive area UA of the substrate.

That is, the electronic component 200 may be disposed on the effective area AA of the substrate 100 in which the pattern portion P is not formed, and the wiring electrode 300 may be formed on the ineffective area UA of the substrate in which the pattern portion P is formed.

Referring to fig. 17 and 18, as described above, the active areas AA of the substrate 100 on which the electronic components 200 are disposed may be prevented from being drawn together when the substrate 100 is drawn, and the inactive areas UA of the substrate 100 on which the wiring electrodes 300 are disposed may be drawn together as much as the substrate is drawn when the substrate 100 is drawn.

Accordingly, in the effective area AA of the substrate 100 on which the electronic component 200 is disposed, the adhesive member adhered to the substrate 100 and the electronic component 200 may be prevented from being peeled off, and thus, even after the substrate 100 is stretched and recovered, the adhesiveness between the substrate 100 and the electronic component 200 may be maintained.

Fig. 19 and 20 are views for describing an example to which the circuit board according to the embodiment is applied.

Referring to fig. 19, the circuit board according to the embodiment may be applied to a flexible display device of a display monitor.

Further, referring to fig. 20, the circuit board according to the embodiment may be applied to a wearable device applied to a human body.

For example, the circuit board according to the embodiment may be applied to a flexible display device such as a mobile phone, a tablet computer, and the like.

The circuit board may be applied to a flexible display device such as a mobile phone, a tablet, etc., which is flexible, bendable, or foldable.

The circuit board is applied to a flexible display device such as a mobile phone, a tablet, etc., which is flexible, bendable, or foldable, and can improve the reliability of the flexible display device by improving the folding reliability of the display device repeatedly folded or restored.

The features, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, but are not limited to only one embodiment. Further, the features, structures, and effects shown in each embodiment can be combined or modified by those skilled in the art to be used for other embodiments. Therefore, it is to be understood that matters related to such combinations and modifications are included within the scope of the present invention.

In addition, the above description has focused on embodiments, but this is merely illustrative and does not limit the invention. It will be understood by those skilled in the art to which the embodiments pertain that various modifications and applications not shown above are possible without departing from the essential features of the embodiments. For example, each component specifically shown in the embodiments may be modified and implemented. In addition, it is to be understood that differences related to such modifications and applications are included within the scope of the present invention as defined in the appended claims.