Electronic apparatus

An electronic apparatus includes a window that includes a substantially planar base and an edge portion that protrudes from an edge of the base, a display panel disposed on the base of the window, and a flexible printed circuit board disposed on and electrically connected to the display panel. The flexible printed circuit board includes a neck portion in contact with the display panel, a body portion connected to the neck portion and that has an area greater than that of the neck portion, and a first slit formed in the body portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. § 119 from Korean Patent Application No. 10-2021-0013473, filed on Jan. 29, 2021 in the Korean Intellectual Property Office, the contents of which are herein incorporated by reference in their entirety.

BACKGROUND

1. Technical Field

One or more embodiments are directed to an electronic apparatus, and more particularly, to an electronic apparatus with fewer defects in a manufacturing process.

2. Discussion of the Related Art

In general, an electronic apparatus such as a smart watch or a smart phone includes a display panel. In addition, a flexible printed circuit board that generates or transmits an electrical signal to the display panel is electrically connected to the display panel. In a manufacturing process of such an electronic apparatus, a display panel is manufactured, a printed circuit board is electrically connected to the display panel, and the display panel and the printed circuit board are placed in a case that forms the overall appearance of the electronic apparatus.

SUMMARY

One or more embodiments include an electronic apparatus with fewer defects in a manufacturing process. However, this is merely an example, and the scope of the disclosure is not limited thereto.

According to one or more embodiments, an electronic apparatus includes a window having a substantially planar base and an edge portion that protrudes from an edge of the bas, a display panel disposed on the base of the window, and a flexible printed circuit board disposed on and electrically connected to the display panel. The flexible printed circuit board includes a neck portion in contact with the display panel, a body portion connected to the neck portion and that has an area greater than that of the neck portion, and a first slit formed in the body portion.

The display panel may be located inside a space defined by the base and the edge portion of the window.

The first slit may extend in a same direction as the neck portion.

Letting A be a minimum distance between an inner surface of the edge portion that faces the display panel and an end of the display panel, B be a thickness of the edge portion at an end of the edge portion, and C be a minimum distance between a lower surface of the display panel and the end of the edge portion, a length L on the printed circuit board from an end of the first slit away from the display panel to the display panel may be greater than or equal to a value satisfying the following equation 1:

The printed circuit board may further include a second slit in the body portion, wherein the first slit may be located on one side of the neck portion, and the second slit may be located on the other side of the neck portion.

A length of the first slit may be a same as a length of the second slit.

The first slit and the second slit may extend in a same direction as the neck portion.

The first slit may extend in a direction that crosses an extension direction of the neck portion.

The first slit may extend in a direction perpendicular to the extension direction of the neck portion.

Letting A be a minimum distance between an inner surface of the edge portion that faces the display panel and an end of the display panel, B be a thickness of the edge portion at an end of the edge portion, and C be a minimum distance between a lower surface of the display panel and the end of the edge portion, a minimum distance D on the printed circuit board between a virtual straight line in an extension direction of the first slit and the end of the display panel may be less than or equal to a value that satisfies the following equation 4:

The printed circuit board may further include a second slit in the body portion, wherein the first slit may be located on one side of the neck portion, and the second slit may be located on the other side of the neck portion and may extend in a same direction as the first slit.

A virtual straight line that passes through the first slit may pass through the second slit.

The first slit may extend in a direction that crosses the neck portion and forms an acute angle with the extension direction of the neck portion.

The printed circuit board may further include a second slit in the body portion, and the second slit may have a shape that is symmetric to the first slit with respect to an extension axis of the neck portion.

An end of the first slit toward the inside of the base may have a semi-polygonal shape.

An end of the first slit in the base may have a curved shape.

The end of the first slit in the base may have a semi-circular shape.

The end of the first slit in the base may have a shape corresponding to at least a portion of a circle whose radius may be greater than a width of the first slit.

One or more embodiments include an electronic apparatus that includes a window that includes a substantially planar base and an edge portion that protrudes from an edge of the base; a display panel disposed on the base of the window; and a flexible printed circuit board disposed on and electrically connected to the display panel. The flexible printed circuit board includes a neck portion in contact with the display panel, a body portion connected to the neck portion and that has an area greater than that of the neck portion, and a first slit formed in the body portion and that extends in a same direction as the neck portion. Letting A be a minimum distance between an inner surface of the edge portion that faces the display panel and an end of the display panel, B be a thickness of the edge portion at an end of the edge portion, and C be a minimum distance between a lower surface of the display panel and the end of the edge portion, a length L on the printed circuit board from an end of the first slit away from the display panel to the display panel is greater than or equal to a value satisfying the following Equation 1:

One or more embodiments include an electronic apparatus that includes a window that includes a substantially planar base and an edge portion that protrudes from an edge of the base; a display panel disposed on the base of the window; and a flexible printed circuit board disposed on and electrically connected to the display panel. The flexible printed circuit board includes a neck portion in contact with the display panel, a body portion connected to the neck portion and that has an area greater than that of the neck portion, and a first slit formed in the body portion and that extends in a direction perpendicular to an extension direction of the neck portion. Letting A be a minimum distance between an inner surface of the edge portion that faces the display panel and an end of the display panel, B be a thickness of the edge portion at an end of the edge portion, and C be a minimum distance between a lower surface of the display panel and the end of the edge portion, a minimum distance D on the printed circuit board between a virtual straight line in an extension direction of the first slit and the end of the display panel is less than or equal to a value satisfying the following equation 4:

These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals may refer to like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein.

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals may refer to like elements throughout, and repeated description thereof may be omitted.

FIG.1is an exploded perspective view of an electronic apparatus according to an embodiment,FIG.2is a perspective view of components shown inFIG.1, andFIG.3is a perspective view of components shown inFIG.2.

An electronic apparatus according to a present embodiment includes a window10, a display panel30, and a flexible printed circuit board40. However, as illustrated inFIG.1, the electronic apparatus may further include various components as necessary. For example, the electronic apparatus further includes a light-transmitting adhesive layer20interposed between the window10and the display panel30to couple the window10and the display panel30, or a cover panel50on the display panel30.

In an embodiment, the window10is formed of a light-transmitting material and may include glass or a polymer resin. For example, the window10may include a polymer resin such as polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, or cellulose acetate propionate.

In an embodiment, the window10includes a base11and an edge portion13. The base11determines the overall appearance of the window10and transmits light. The edge portion13protrudes from an edge of the base11upward from a first virtual plane on which the base11is located.FIG.1shows that the base11is located on the first virtual plane that is approximately parallel to an x-y plane and the edge portion13protrudes from an edge of the base11in a +z direction perpendicular to the x-y plane. The base11and the edge portion13include a same material and are integrally formed, but embodiments of the disclosure are not limited thereto. For example, in other embodiments, the edge portion13is a separate component coupled to the edge of the base11. In this case, the edge portion13is non-transmissive, unlike the light-transmitting base11.

In an embodiment, the base11is located in the first virtual plane, but portions of the base may be curved. For example, when the electronic apparatus is a smart watch, the base11of the window10has a flat shape as a whole, but an outer surface of the base11opposite to the display panel30includes a portion that is microscopically curved in the −z direction.

In an embodiment, the display panel30is disposed on the base11of the window10. The display panel30includes a circuit that includes an electronic apparatus such as a thin film transistor on a substrate, and a display device such as an organic light-emitting device electrically connected to the circuit. However, embodiments of the disclosure are not limited thereto. In other embodiments, the display panel30includes various other display devices, such as a liquid crystal device.

In an embodiment, the printed circuit board40is flexible. This printed circuit board40is electrically connected to the display panel30. For example, as illustrated inFIG.1, a portion of the printed circuit board40is electrically attached onto a surface of the display panel30in a direction toward the window10. In this case, wires of the printed circuit board40are electrically connected to pads located on the surface of the display panel30through an anisotropic conductive film, etc.

In an embodiment, the printed circuit board40includes a body portion41and a neck portion43. The neck portion43contacts the display panel30as described above. The body portion41has an area greater than that of the neck portion43, and an electronic apparatus such as an integrated circuit is attached to the body portion41of the printed circuit board40through an anisotropic conductive film, etc. The printed circuit board40has a first slit40s1formed in the body portion41.

In an embodiment, the cover panel50is formed of, for example, metal. The cover panel50is disposed on the display panel30in a +z direction opposite to the window10, and shields the display panel30from external electrical signals or electromagnetic waves.

In an embodiment, the display panel30and the cover panel50are disposed on the window10as shown inFIG.2. That is, the display panel30and the cover panel50are located inside a space defined by the base11and the edge portion13of the window10. The printed circuit board40electrically connected to the display panel30is bent at the neck portion43as shown inFIG.3so that the body portion41is located on the cover panel50. Because the printed circuit board40is flexible, as described above, the neck portion43is flexible and is bent as shown inFIGS.2and3so that the body portion41is placed on the cover panel50. If necessary, the body portion41is also flexible. In this case, the neck portion43is more flexible than the body portion41.

FIG.4is a perspective view of a portion of an electronic apparatus according to a comparative example in a manufacturing process of the electronic apparatus according to the comparative example. As described above, in a manufacturing process of an electronic apparatus, the display panel30and the cover panel50are located in a space defined by the base11and the edge portion13of the window10. Thereafter, the printed circuit board40is bent at the neck portion43so that the body portion41of the printed circuit board40is located on the display panel30and the cover panel50.FIG.4illustrates a process of placing the display panel30and the cover panel50, etc., in the space defined by the base11and the edge portion13of the window10in the manufacturing process of the electronic apparatus.

In a manufacturing process of an electronic apparatus, the printed circuit board40is initially located outside the space defined by the base11and the edge portion13of the window10. In this process, the neck portion43is bent in a direction opposite to a direction in which the body portion41is bent so that the body portion41is located above the display panel30, as illustrated inFIG.4. At this time, because an area of the body portion41of the printed circuit board40is greater than an area of the neck portion43, a relatively large amount of stress is applied to the neck portion43. In particular, when an electronic apparatus such as an integrated circuit is mounted on the body portion41, a weight of the body portion41increases, and thus, a large amount of stress is applied to the neck portion43. Such stress is particularly concentrated on a first portion40athat is a virtual boundary between the neck portion43and the body portion41, and a second portion40bthat is outside of the display panel30. Accordingly, some of wirings on the neck portion43of the printed circuit board40can be disconnected. In some cases, a crack occurs in the neck portion43, or the printed circuit board40is cut at the neck portion43.

In the case of an electronic apparatus according to a present embodiment, as described above, the printed circuit board40has the first slit40s1in the body portion41.FIG.5illustrates how the neck portion43is bent in a direction opposite to a direction in which the body portion41is bent such that the body portion41is located above the display panel30in a manufacturing process of an electronic apparatus according to a present embodiment. In the case of an electronic apparatus according to a present embodiment, as described above, the printed circuit board40has the first slit40s1in the body portion41. Therefore, even if the neck portion43is bent in the direction opposite to the direction in which the body portion41is bent such that the body portion41is located above the display panel30, stress applied to the neck portion43is reduced.

In particular, as various functions are added to a smart watch, the protrusion of the edge portion13of the window10from the first virtual plane of the base11increases. This is to place more electronic apparatuses, such as a small camera or a large capacity battery, in the space defined by the base11and the edge portion13of the window10. On the other hand, in the case of an electronic apparatus according to a comparative example shown inFIG.4, as the protrusion of the edge portion13increases, the stress applied to the neck portion43of the printed circuit board40increases in a manufacturing process.

However, in an electronic apparatus according to a present embodiment, because the printed circuit board40has the first slit40s1in the body portion41as shown inFIG.5, the flexibility near the first slit40s1of the body portion41as well as the neck portion43is further increased, and accordingly, stress applied to the neck portion43is reduced. The first slit40s1extends in a same direction as the neck portion43. Through this, the flexibility near the first slit40s1of the body portion41increases.

As a result of a simulation, in the case of the comparative example shown inFIG.4, the amount of stress applied to the first portion40ais 168.770 MPa, and the amount of stress applied to the second portion40bis 785.882 MPa. However, in an embodiment shown inFIG.5, the amount of stress applied to the first portion40ais only 109.265 MPa, and the amount of stress applied to the second portion40bis only 487.378 MPa. Accordingly, in an embodiment ofFIG.5, the amount of stress applied to the neck portion of the printed circuit board40is reduced by approximately 38% as compared to the case ofFIG.4.

FIG.6is a plan view of a portion of an electronic apparatus ofFIG.1in a manufacturing process of an electronic apparatus ofFIG.1.FIG.6shows that the neck portion43of the printed circuit board40is not bent so that the printed circuit board40and the display panel30are located in substantially the same x-y plane when the printed circuit board40is electrically connected to the display panel30. As shown inFIG.6, the first slit40s1extends in a same x-axis direction as the neck portion43. At this time, a length L of the printed circuit board40from an end of the neck portion43on the display panel30to an end of the first slit40s1in a direction away from the display panel30, is greater than or equal to a value that satisfies Equation 1 below.

Here, referring toFIG.7, which is a side cross-sectional view of a portion of an electronic apparatus ofFIG.1, A is a minimum distance between an inner surface of the edge portion13at an end of the edge portion13of the window10and an end of the display panel30. The inner surface of the edge portion13of the window10is a surface of the edge portion13that faces the display panel30. B is a thickness of the edge portion13at the end of the edge portion13of the window10. In addition, C is a minimum distance between a second virtual plane of a lower surface of the display panel30and the end of the edge portion13of the window10. Hereinafter, a derivation process of Equation 1 will be described.

According to the Pythagorean theorem, a length of the hypotenuse of a right triangle with one side having length A+B and another side having length C is expressed as Equation 2 below.
√{square root over ((A+B)2+C2)}  Equation 2:

Let a sector with such a hypotenuse be a chord; the sector has an arc AC indicated by dashed lines inFIG.7. A central angle of the arc AC can be expressed as in Equation 3, below, by using a length of the chord in Equation 2. Here, as shown inFIG.7, the length of A+B is approximately similar to the length of C, so a radius of the sector can be approximated to (A+B+C)/2. That is, a central angle of the sector whose radius is (A+B+C)/2 and whose chord has the length of Equation 2 can be expressed as Equation 3 below.

Because a length of the arc of a sector having such a central angle is the product of the approximate radius of (A+B+C)/2 and the central angle of Equation 3, the result of Equation 1 can be obtained. As shown inFIG.7, a surface of the printed circuit board40substantially coincides with the arc AC indicated by dashed lines. Therefore, when the length L on the printed circuit board40from an end of the first slit40s1away from the display panel30to the display panel30satisfies Equation 1 as described above, the end of the first slit40s1away from the display panel30is approximately located at the end of the edge portion13of the window10. Therefore, when the length L on the printed circuit board40from the end of the first slit40s1away from the display panel30to the display panel30satisfies Equation 1 as described above, even if the printed circuit board40is bent outside the window10, stress applied to the neck portion43of the printed circuit board40due to such bending can be minimized.

FIG.8is a plan view of a portion of an electronic apparatus in a manufacturing process according to an embodiment. As shown inFIG.8, the printed circuit board40further includes a second slit40s2in the body portion41. Here, the first slit40s1is on one side of the neck portion43and the second slit40s2is on the other side of the neck portion43. The first slit40s1and the second slit40s2extend in a same direction as the neck portion43. Through this, even if the printed circuit board40is bent outside the window10during a manufacturing process, stress applied to the neck portion43of the printed circuit board40due to such bending can be further reduced as compared to when the printed circuit board40has only one slit.

In this case, in an embodiment shown inFIG.8, a length of the first slit40s1is the same as a length of the second slit40s2. However, the lengths of the first slit40s1and the second slit40s2may be greater than or equal to the value satisfying Equation 1 above.

FIG.9is a plan view of a portion of an electronic apparatus in a manufacturing process according to an embodiment. An electronic apparatus according to a present embodiment differs from an electronic apparatus according to embodiments described above with reference toFIGS.1to8with regard to a direction of the first slit40s1. In an electronic apparatus according to a present embodiment, the first slit40s1formed in the body portion41of the printed circuit board40extends in a direction that crosses an extending direction of the neck portion43. In more detail, the first slit40s1formed in the body portion41of the printed circuit board40extends in a direction perpendicular to the direction in which the neck portion43extends. In other words, the neck portion43extends in the x direction, and the first slit40s1extends in the y direction perpendicular to the x direction. In an electronic apparatus according to a present embodiment, even if the flexibility near the first slit40s1of the body portion41increases, and the printed circuit board40is bent outside the window10during a manufacturing process, stress applied to the neck portion43due to such bending is effectively reduced.

On the other hand, in an embodiment, the minimum distance D on the printed circuit board40between a virtual straight line in the y direction and an end of the display panel30is less than or equal to a value satisfying Equation 4 below.

Here, A, B, and C are the same as those described above with reference toFIG.7. In other words, A is a minimum distance between an inner surface of the edge portion13at the end of the edge portion13of the window10and the end of the display panel30, as shown inFIG.7. The inner surface of the edge portion13is a surface of the edge portion43that faces the display panel30. B is a thickness of the edge portion13at the end of the edge portion13of the window10. In addition, C is a minimum distance between a second virtual plane of a lower surface of the display panel30and the end of the edge portion13of the window10.

In an embodiment, a derivation process of Equation 4 as described above is the same as the derivation process of Equation 1 described above. When the printed circuit board40has a value of D that satisfies t Equation 4, the first slit40s1is located on the end of the edge portion13of the window10. When the printed circuit board40is bent outside the window10in a manufacturing process, the printed circuit board40can be easily bent at the end of the edge portion13of the window10where the first slit40s1is formed, and thus, stress applied to the neck portion43can be minimized.

On the other hand, if this first slit40s1is formed outside the end of the edge portion13of the window10, stress applied to the neck portion43by the first slit40s1cannot be relieved. This is because, in such a case, the body portion41, which is wider than the neck portion43, contacts the end of the edge portion13when the first slit40s1is formed outside the end of the edge portion13of the window10. Therefore, the minimum distance D on the printed circuit board40between the virtual straight line and the end of the display panel30is less than or equal to the value satisfying Equation 4 below.

FIG.10is a plan view of a portion of an electronic apparatus in a manufacturing process according to an embodiment. In an electronic apparatus according to a present embodiment, unlike an electronic apparatus described above with reference toFIG.9, the printed circuit board40includes a second slit40s2in the body portion41. Here, the first slit40s1is on one side of the neck portion43and the second slit40s2is on the other side of the neck portion43. In addition, as shown inFIG.10, the second slit40s2extends in a same direction as the first slit40s1, namely the y-direction. In an electronic apparatus according to a present embodiment, even if the printed circuit board40is bent outside the window10during a manufacturing process, stress applied to the neck portion43of the printed circuit board40due to such bending is further reduced as compared to when the printed circuit board40has only one slit. Here, as shown inFIG.10, a virtual straight line that passes through the first slit40s1also passes through the second slit40s2.

FIG.11is a plan view of a portion of an electronic apparatus in a manufacturing process according to an embodiment. In an electronic apparatus according to a present embodiment, the first slit40s1extends in a direction that crosses the neck portion43at an acute angle with respect to an extension direction of the neck portion43. That is, the first slit40s1extends in a direction oblique to the extension direction of the neck portion43. Through this, even if the printed circuit board40is bent outside the window10during a manufacturing process, stress applied to the neck portion43of the printed circuit board40due to such bending is reduced. In addition, to maximize the effect of this stress reduction, the printed circuit board40further includes a second slit40s2in the body portion41as shown inFIG.11, and the second slit40s2has a shape that is symmetric to the first slit40s1with respect to an extension axis of the neck portion43. In addition, the body portion41includes a plurality of each of the first slit40s1and the second slit40s2.

In various embodiments described so far, an end of the first slit40s1toward the inside of the body portion41has a semi-polygonal shape.FIGS.1to11show that the end of the first slit40s1toward the inside of the body portion41has a semi-rectangular shape that includes two right angles. However, embodiments of the disclosure are not limited thereto.

For example, according to an embodiment, as shown inFIG.12, which is a plan view of a portion of an electronic apparatus in a manufacturing process according to an embodiment, an end of the first slit40s1in the body portion41has a curved shape. In more detail, the end of the first slit40s1in the body portion41has a semicircular shape. In addition, as shown inFIG.13, which is a plan view of a portion of an electronic apparatus in a manufacturing process according to another embodiment, the end of the first slit40s1in the body portion41has a shape corresponding to at least a portion of a circle whose radius is greater than a width of the first slit40s1. Even if stress is applied to the end of the body portion41of the first slit40s1, the stress is dispersed i through these structures, so that the occurrence of cracks, etc., in a printed circuit board at the end of the first slit40s1is effectively prevented. In addition, the the second slit40s2may also have this shape.

Until now, a case in which the base11has a substantially circular shape when viewed in a plan view has been described. However, embodiments of the disclosure are not limited thereto. A case where the base11has an oval or rectangular shape in a plan view is also within the scope of the disclosure.

According to an embodiment as described above, an electronic apparatus with fewer defects in a manufacturing process can be implemented. However, the scope of embodiments of the disclosure is not limited to the effect.