This Application claims priority of Taiwan Patent Application No. 100142226, filed on Nov. 18, 2011, the entirety of which is incorporated by reference herein.
1. Field of the Disclosure
The present disclosure relates to an electronic device, and in particular relates to an electronic apparatus and a display apparatus using a shape memory alloy as a substrate.
2. Description of the Related Art
With progress of display technologies and information products, displays have moved to the flat panel display age from the traditional cathode ray tube age. Compared to traditional rigid glass flat panel displays, flexible displays are thinner, lighter, flexible, impact-resistant, safe, and not limited by condition and space, so the potential new trend for development of displays in the next age is towards flexible displays.
A flexible thin film transistor substrate is one of the important devices of a flexible display, and selection and development of materials of the substrate are important issues in the development of the flexible display. At present, the flexible substrate may be a plastic substrate., While the plastic substrate is light, thin, impact-resistant, and low cost, it suffers from a lack of high temperature resistance, moisture resistance, and oxygen resistance, and high thermal expansion coefficients. Furthermore, flexible electronic apparatuses or flexible display apparatuses may have a bent shape, a shape like a roll, or a flat shape, etc., and may change shapes for different application conditions (or for different application needs). Thus, suitable materials for forming the substrate are needed.
An embodiment of the disclosure provides an electronic apparatus which includes: a shape memory alloy substrate; and an electronic device disposed on the shape memory alloy substrate.
An embodiment of the disclosure provides a display apparatus, includes: a shape memory alloy substrate; a pixel circuit layer disposed on the shape memory alloy substrate; and a display element layer disposed on the pixel circuit layer.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
The present disclosure can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
The following description is one of of the contemplated mode of carrying out the disclosure. This description is made for the purpose of illustrating the general principles of the disclosure and should not be taken in a limiting sense. The scope of the disclosure is best determined by reference to the appended claims.
It is understood, that the following disclosure provides many different embodiments, or examples, for implementing different features of the disclosure. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numbers and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Furthermore, descriptions of a first layer “on,” “overlying,” (and like descriptions) a second layer, include embodiments where the first and second layers are in direct contact and those where one or more layers are interposing the first and second layers.
The present disclosure uses a shape memory alloy to form a substrate of a flexible electronic apparatus (or a flexible display apparatus), wherein the shape memory alloy has moisture resistance and oxygen resistance which are better than that of plastic substrates, and has impact-resistance and high stability. The shape memory alloy has plasticity in room temperature, so the shape memory alloy may be bent to be shaped according to application needs, and the shape memory alloy may be recoverable to its original shape (e.g. a flat shape) or the like (e.g. a slightly bent shape) by heating the shape memory alloy (at a temperature higher than room temperature). The present disclosure disposes the electronic device directly on the shape memory alloy substrate instead of on a general substrate (e.g. a glass substrate or a plastic substrate) and then being attached to a shape memory alloy substrate. Accordingly, the present disclosure may reduce the total thickness of the flexible electronic apparatus (or the flexible display apparatus).
It should be noted that, the present embodiment disposes the electronic device 120 directly on the shape memory alloy substrate 110 to take the shape memory alloy substrate 110 as the substrate directly carrying the electronic device 120 without disposing an additional electronic device substrate thereon, which reduces the total thickness of the electronic apparatus 100.
A thickness T of the shape memory alloy substrate 110 is, for example, about 5 μm to 5 mm. In one embodiment, the thickness T of the shape memory alloy substrate 110 is about 20 μm to 200 μm. A maximum-width W1 of the shape memory alloy substrate 110 is larger than or equal to a maximum-width W2 of the electronic device 120. That is to say, the size of the shape memory alloy substrate 110 is larger than or equal to the size of the electronic device 120. In one embodiment, the shape memory alloy substrate 110 has a surface 118 which is an exposed surface located at a side of the shape memory alloy substrate 110 opposite to the electronic device 120, wherein there is no device disposed on the exposed surface. In another embodiment, the electronic device 120 may dispose on both surfaces of the shape memory alloy substrate 110.
The material of the shape memory alloy substrate 110 is, for example, a one-way type memory alloy, a two-way type memory alloy, or a pseudo-elastic type memory alloy. When the material of the shape memory alloy substrate 110 is the one-way type memory alloy, the shape memory alloy substrate 110 may be set (or trained) in a flat shape or a bent shape. When the shape memory alloy substrate 110 is set in the bent shape, the shape memory alloy substrate 110 may be flatly fixed on the stage (not shown) by using clips or by evacuation in the process of manufacturing the electronic device 120.
The material of the shape memory alloy substrate 110 is, for example, a nickel-based alloy, a copper-based alloy, a ferrous-base alloy, a gold-based alloy, or combinations thereof, or other suitable alloys. Specifically, the material of the shape memory alloy substrate 110 may be a nickel-titanium alloy, a nickel-aluminum alloy, a copper-aluminum-nickel alloy, a copper-aluminum-zinc alloy, a copper-gold-zinc alloy, a copper-tin alloy, a copper-zinc alloy, a silver-cadmium alloy, a gold- cadmium alloy, or combinations thereof. The shape memory alloy substrate 110 may be formed by, for example, rolling of an ingot into a plate form or depositing of a thin film on a carrying film (such as using a sputtering process or a vapor deposition process).
In one embodiment, before the electronic device 120 is disposed on the shape memory alloy substrate 110, a planarization process may be performed on the surfaces 116, and 118 of the shape memory alloy substrate 110, wherein the planarization method includes milling, polishing, wet etching, dry etching, or disposing a planar film by plating, coating or deposition on the surfaces 116, and 118, wherein the planar film is formed of metal, polymer, oxides, or nitrides. The electronic device 120 is formed by using, for example, thin-film deposition processes, photo-lithography processes, and etching processes, or by using screen printing processes, and inkjet printing processes, or other thick film processes. The electronic device 102 may also include additional components, such as passive components (resistors, capacitors and inductors) or IC chips assembled by surface mount technology (SMT) or insertion method.
The surface 116 of the shape memory alloy substrate 110 has a central area 116a and a peripheral area 116b surrounding the central area 116a. The electronic device 120 may be disposed in the central area 116a. The first heating electrode 142 and the second heating electrode 144 are both located in the peripheral area 116b and are respectively located at two opposite sides of the central area 116a (e.g. up and down sides as shown in
In the embodiment,
The first heating electrode 142 and the second heating electrode 144 may be respectively applied with different voltages, such that a current passes through the shape memory alloy substrate 110 connecting between the first heating electrode 142 and the second heating electrode 144, and thereby the shape memory alloy substrate 110 is heated due to the resistance of the shape memory alloy substrate 110. For example, the first heating electrode 142 is applied with a negative voltage, and the second heating electrode 144 is applied with a positive voltage. Alternatively, the first heating electrode 142 and the second heating electrode 144 may be applied with an alternating current.
In actual applications, the shape memory alloy substrate 110 may be bent (e.g. annular electronic apparatuses, such as watches). Then, when the shape memory alloy substrate 110 is needed to be recovered to its original flat shape or the like, the first heating electrode 142 and the second heating electrode 144 may be respectively applied with different voltages to heat the shape memory alloy substrate 110 so as to recover to its original flat shape or the like.
Although
In this case, the first heating electrodes 142 and the second heating electrode 144 may be respectively applied with different voltages, such that a current passes through the shape memory alloy substrate 110 connecting between the first heating electrodes 142 and the second heating electrode 144 to heat the shape memory alloy substrate 110.
In one embodiment, when the shape memory alloy substrate 110 is a composite substrate, a portion of the polymer layer 114 may be removed to expose a portion of the shape memory alloy fibers 112a, and the first heating electrode 142 and the second heating electrode 144 may be formed on the exposed shape memory alloy fibers 112a to electrically connect to the shape memory alloy fibers 112a.
In the present embodiment, the electronic device 120 and the heater 146 may be respectively located on the surfaces 116 and 118 of the shape memory alloy substrate 110. In other embodiments, the electronic device 120 and the heater 146 may be both located on the surface 116. When the shape memory alloy substrate 110 is a composite substrate, the heater 146 may be used to recover to the original shape of the shape memory alloy substrate 110.
The heater 146, the first heating electrode 142, and the second heating electrode 144 are optional elements. That is to say, other external apparatuses may be used to heat the shape memory alloy substrate 110, or a shape memory alloy with a pseudo-elastic property is used to form the substrate. When the shape memory alloy substrate 110 with the pseudo-elastic property is used, a mechanical part (not shown) may be used to fix the shape of the shape memory alloy substrate 110, and the shape memory alloy substrate 110 may recover to its original shape by removing the mechanical part.
The pixel structure and the display mode of the display element layer 160 may be emissive type or reflective type, for example, an organic light emitting diode (OLED), an electrophoretic display (EPD), a liquid crystal display (LCD), an electrowetting display (EWD), a quick-response liquid powder display (QR-LPD), or combinations thereof, or other display modes, wherein the liquid crystal display may be a micro-encapsulated cholesteric liquid crystal display (ChLCD) or a twisted nematic liquid crystal display (TN-LCD). The pixel circuit layer 150 is, for example, an active-matrix driving circuit layer, a passive-matrix driving circuit layer, a segmented driving circuit layer, or combinations thereof.
A thickness T of the shape memory alloy substrate 110 is, for example, about 5 μm to 5 mm. In one embodiment, the thickness T of the shape memory alloy substrate 110 may be about 20 μm to 200 μm. In one embodiment, the shape memory alloy substrate 110 is a composite substrate, and the material and the structure of the composite substrate of the present embodiment are similar to the composite substrate shown in
The surface 116 of the shape memory alloy substrate 110 has a central area 116a and a peripheral area 116b surrounding the central area 116a. The pixel circuit layer 150 may be disposed in the central area 116a, and the pixel circuit layer 150 may include thin film transistors and may further include driver integrated circuits (driver ICs), and devices (such as control circuits and power modules) required for displaying images may be disposed on the periphery of the central area 116a (not shown). The first heating electrode 142 and the second heating electrode 144 are both located in the peripheral area 116b and are respectively located at two opposite sides of the central area 116a (e.g. up and down sides or left and right sides as shown in
In view of the foregoing, the present disclosure disposes the electronic device (or the pixel circuit layer and the display element layer) directly on the shape memory alloy substrate to take the shape memory alloy substrate as the substrate directly carrying the electronic device (or the pixel circuit layer and the display element layer) without disposing of an additional electronic device substrate (or a display device substrate), which reduces the total thickness of the flexible electronic apparatus (or the flexible display apparatus).
While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
Number | Date | Country | Kind |
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TW100142226 | Nov 2011 | TW | national |