Wireless chip and electronic appliance having the same

Abstract

The present invention provides a wireless chip having high mechanical strength. Moreover, the present invention also provides a wireless chip which can prevent an electric wave from being blocked. In a wireless chip of the present invention, a layer having a thin film transistor formed over an insulating substrate is fixed to an antenna by an anisotropic conductive adhesive, and the thin film transistor is connected to the antenna. The antenna has a dielectric layer, a first conductive layer, and a second conductive layer; the first conductive layer and the second conductive layer has the dielectric layer therebetween; the first conductive layer serves as a radiating electrode; and the second electrode serves as a ground contact body.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a wireless chip which can send and receive data through wireless communication and an electronic appliance having the wireless chip. [0003] 2. Description of the Related Art [0004] In recent years, development of a wireless chip including a plurality of circuits and an antenna has been advanced. Such a wireless chip is referred to as an ID tag, an IC tag, an IC chip, an RF (Radio Frequency) tag, a wireless tag, an electronic tag, or an RFID (Radio Frequency IDentification) tag, and has been already introduced into some markets. [0005] Many of these wireless chips which are currently in practical use have circuits using semiconductor substrates such as silicon (such circuits are also referred to as IC (Integrated Circuit) chips) and antennas. The antenna is formed by a printing method, a method in which a conductive thin film is etched, a plating method, or the like (see, for example,...

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Benefits of technology

[0008] In view of the above problems, it is an object of the present invention to provide a wireless chip in which mechanical strength can be increased. Moreover, it is an object of the present invention to provide a wireless chip which can prevent an electric wave from being blocked.

[0027] The layer having the thin film transistor formed over the insulating substrate can be formed so as to have almost the same dimension as the antenna. The insulating substrate serves as a protector for the layer having the thin film transistor as well as a protector for the antenna. Therefore, the mechanical strength of the wireless chip increases.

[0028] Since a patch antenna has high mechanical strength, the patch antenna can be used repeatedly. Therefore, a wireless chip having a patch antenna can be provided to a recyclable container such as a returnable container.

[0029] Further, since an integrated circuit is formed using electrically-isolated thin film transistors in a wireless chip of the present invention, an electric wave is more difficult to be blocked than in a wireless chip having an integrated circuit formed using a semiconductor substrate, thereby suppressing the attenuation of a signal due to the block of an electric wave. Thus, it is possible to send and receive data with high efficiency.

[0030] Since a wireless chip including an integrated circuit which is formed using a thin film transistor and a passive element formed with a thick film pattern has each circuit formed with an element having an appropriate function, the wireless chip has composite functions. By mounting a wireless chip of the present invention to a wiring substrate, the number of mount parts can be decreased, thereby allowing the size reduction of a wiring substrate dimension as well as the electronic appliance having the wiring substrate.

Problems solved by technology

The antenna attached to a flexible material such as paper or plastic has a problem in that the antenna is sensitive to bending or folding, so that a part of the antenna is easily broken.

Moreover, in the case of a wireless chip formed using a semiconductor substrate, the semiconductor substrate serves as a conductor and blocks an electric wave; therefore, there is a problem in that a signal is easily attenuated depending on a direction from which a signal is sent.

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