TWI447243B - Thin film antenna and the method of forming the same - Google Patents

Description

Thin film antenna and manufacturing method thereof

The present invention relates to an antenna, and more particularly to a thin film antenna.

In recent years, wireless transmission technology has been widely developed all over the world, and most wireless devices, such as mobile phones, personal digital assistants, and digital televisions, need to use receiving devices that receive transmission signals. Due to the digitization of information transmission, various information such as audio signals and video signals can be easily processed by personal computers, mobile devices, etc., and audio and video encoding and decoding technologies can enhance the frequency band compression of the above information types. Digital communication and digital communication can create an environment that easily and efficiently delivers such information to terminal equipment, such as transmitting audiovisual material (AV data) to a portable telephone.

Wireless transmission uses an externally protruding antenna for signal exchange between devices. RF circuits, transmission lines and antenna elements are usually fabricated on specially designed substrates. For the purpose of these circuits, the control of maintaining impedance characteristics cannot be ignored. Therefore, in these circuits, the length of transmission lines and transmitting antennas is a key design element. . Two important key factors affecting the performance of the substrate material are the dielectric constant (sometimes referred to as the relative dielectric constant) and the dielectric loss (sometimes referred to as the dissipation factor), where the dielectric constant determines the rate at which the signal is transmitted in the substrate material. And the length of the transmission line associated with the transmission and transmission of other components applied to the substrate. The dielectric loss is the loss caused by the transmission of the signal in the base material, and the loss increases as the frequency becomes larger.

A micro-strip antenna structure places a signal line on the surface of the board and provides a conductive layer, which is generally referred to as a ground plane. The other is a buried micro-strip antenna structure, which is similar to the first structure except that its signal line is covered by a dielectric substrate material. The third type is a strip-line structure in which the signal lines are sandwiched between two conductive (ground) planes, and the antennas are disposed on the main plane of the printed circuit board. For vehicle applications, most of the solutions for such systems are to mount the whip antenna on the roof of the car. Compared to the current trend of car design, these antennas are embedded in the vehicle structure to reduce the antenna aesthetics. With the influence of aerodynamics. Moreover, the integration of several telecommunications services into a single antenna will reduce the cost of manufacturing. The antenna receiving frequency band includes: Frequency Modulation (FM), Personal Handyphone System (PHS), Wireless car aperture, Global System for Mobile Communications (GSM Former; GSM 900, GSM 1800), code division multiple access (Code Division Multiple Access; CDMA), General Package Radio Service (GPRS), Bluetooth, Wireless Local Area Network (WLAN), and the band of digital television.

Some antenna structures can only operate in a preset frequency band, which is limited by the characteristics of the antenna and thus is not suitable for multi-frequency operation, and the material of the antenna is nothing more than metal or alloy. If it is formed on glass, it will be formed on the glass. Affect visibility. In addition, most of the current antennas use electroplating processes to make planar antennas, and the electroplating solution therein will cause environmental pollution, and the cost of raw materials of metal blocks is relatively high.

The present invention relates to a film antenna having the following characteristics.

The invention provides a method for fabricating a thin film antenna, the main steps of which comprise driving a substrate horizontally by a rotating shaft to a rotating shaft device, and forming a material of the antenna by physical sputtering, deposition or evaporation to facilitate the material. A film is formed on the substrate driven by the spindle to the spindle device, and then applied to the antenna film by mechanical force or etching or laser to form an antenna pattern. Wherein the antenna material comprises one or a combination of the following groups of gold, zinc, silver, palladium, platinum, rhodium, iridium, copper, iron, nickel, cobalt, tin, titanium, indium, aluminum, lanthanum, gallium, lanthanum and antimony. The antenna material may also contain a non-metal oxide such as indium tin oxide or zinc oxide, or may be a conductive polymer. The method for fabricating the thin film antenna comprises heating or/or lifting the surface energy of the antenna film. Antenna patterns include monopole, dipole, logarithmic period antennas, double spirals, fractal or inverted F antenna patterns, rectangles, peaks, lines, triangles, hexagons, circles, trapezoids, combs, scorpions or branches shape.

In other embodiments, the method of fabricating a thin film antenna includes providing a soft substrate having an antenna film attached thereto, wherein the antenna film is sputtered, physically deposited, vapor deposited, coated, sprayed. The antenna film is applied by mechanical force or etching or laser to form an antenna pattern. In order to improve the adhesion between the two or to improve the flatness of the substrate, a buffer layer may be formed between the substrate and the antenna film. The antenna film described above is horizontally moved by a rotating shaft to a rotating shaft device to form the antenna film on the soft substrate.

The thin film antenna manufacturing device of the present invention comprises a physical sputtering, deposition or evaporation energy source to facilitate sputtering, deposition or evaporation of particles or gas; and a shaft to a rotating shaft device for driving the substrate to move horizontally, The antenna film is deposited onto the substrate by physical sputtering, deposition or evaporation. The thin film antenna manufacturing device further includes a heating device and a vacuum pump.

The invention discloses a film antenna for use in a vehicle, an electronic device or a portable device. This antenna is fabricated on a soft substrate, which is different from traditional antenna substrates. Therefore, the substrate has a flexible region, which is advantageous for attaching to an irregular surface or an uneven surface, and is suitable for the rotary shaft process of the present invention. In order to improve the adhesion between the two or to improve the flatness of the substrate, a buffer layer may be formed between the substrate and the antenna film. The antenna film described above is horizontally moved by a rotating shaft to a rotating shaft device, so that the antenna film is formed on a soft substrate, and the thickness of the film can be controlled by the shaft speed. The above antenna system can be physically deposited by sputtering, evaporation, inkjet, coating, and spraying.

In one embodiment, the apparatus for fabricating a thin film antenna of the present invention, the main features of which include: a cavity or process chamber 100 in which an antenna target 102 is disposed, and a power source 104 is used to provide physical A physical sputter or a physically deposited source of energy that physically strikes a target to facilitate the formation of physical sputters or physical vapor deposition (PVD). The physical vapor deposition method may include an electron gun, a laser (laser), a plasma source, and physical sputtering. RF-sputter, DC-sputter may be used. It is also possible to use a vapor deposition film to form a dry pan for carrying the material to be heated to facilitate the formation of a gas. A shaft to roll to roll device 106 is disposed in the chamber 100 corresponding to or at a lower side of the target position. The shaft-to-spindle device 106 is driven by a driving device, such as a motor, to rotate according to a rotating shaft, and the soft substrate is moved, for example, rotating in the direction of the rotating arrow, so that the substrate 110 can be rolled from one end to the other. One end. During this process, the substrate 110 is driven to move horizontally (as shown by a horizontal arrow). During deposition, evaporation or sputtering, material particles (forming the material of the antenna) 112 will be deposited or plated on the horizontal moving substrate described above. Above 110. The speed of the rotating shaft can be controlled to control the horizontal moving speed and thus the thickness of the antenna material. The heating device 108 is correspondingly disposed on the lower side of the horizontal moving material, and can selectively turn on the heating device to provide a heat source for forming an antenna film. To facilitate evaporation, sputtering or deposition procedures, a vacuum pump 114 is coupled to the cavity 100 to facilitate lowering the gas pressure within the chamber to achieve a suitable degree of vacuum, such as 0.0001 - 0.1 torr. In order to facilitate the introduction and derivation of the gas, the cavity 100 is also provided with a gas inlet port 118 and a discharge port 116. The material of the substrate 110 is preferably soft or flexible, and may be PET, PC, PVC, PI, PMMA, polymer or a flexible circuit board. The heating device 108 can be a light bulb, electromagnetic radiation or an infrared heater. The target material 102 may be selected from a conductive carbon, wherein the conductive carbon comprises a carbon nano-tube (CNT); it may also optionally comprise one or a combination of the following groups: gold, zinc, Silver, palladium, platinum, rhodium, ruthenium, copper, iron, nickel, cobalt, tin, titanium, indium, aluminum, antimony, gallium, antimony and antimony. Indium tin oxide or indium zinc oxide and conductive polymer can also be used as the material of the antenna target.

The antenna pattern includes a monopole, dipole, logarithmic antenna or inverted F antenna pattern. Wherein the antenna pattern comprises a fractal, a rectangle, a peak shape, a straight line, a triangle, a hexagon, a circle, a trapezoid, a comb shape, a city shape or a dendritic shape. Wherein the fractal element is a stack of fractal basic patterns stacked at least once. The above-described iterations place the fractal basic pattern on the base pattern in one or a combination of the following methods: (1) rotation, (2) elongation, and (3) translation. It can be configured in handheld devices, mobile phones, notebook computers, personal digital assistants, portable devices, transportation vehicles, NFC applications. In the above antenna device, the antenna can be fabricated on an outer surface or an inner surface of a device housing, and the feature includes a shielding structure disposed between the antenna and the circuit board. Some conductive materials made in this way are transparent, and if the antenna is attached to a glass or window, it will have visual penetration. The antenna can also be attached to the outer casing of the bulb in the vehicle. Since the outer casing is less transparent than the window, the present invention can be formed on the outer casing of the bulb in the vehicle. Alternatively, the antenna can be formed on a housing or screen of a notebook or mobile phone or the like to avoid shielding effects. In this case, the conductive layer is usually composed of an oxide having a metal, wherein the metal is preferably one or more selected from the group consisting of gold, zinc, silver, palladium, platinum, rhodium, ruthenium, copper, iron, nickel, cobalt, Tin, titanium, indium, aluminum, antimony, gallium, antimony and antimony metals. The above transparent antenna material such as indium tin oxide or indium zinc oxide may be doped with aluminum oxide (Al ₂ O ₃ ). The feed structure can be achieved by a capacitive coupling, which is a well-known technique in the art, and can be improved by using spatial-diversity or polarization variation techniques. Two or more multi-frequency antennas or an antenna array can also be used herein, and the technique described in the present invention has the advantage that a plurality of antennas attached to the same transparent window can include different structures at low cost. This feedthrough structure is a technique well known in the art, and the structure of other multi-frequency antennas can also be applied to the same fields and spirits of the present invention. The antennas are presented in different configurations (eg, the array has different steering orientations). When polarization variation is utilized to compensate for signal attenuation due to fast transition transmission environments, a polygonal base structure can be selected as an alternative shape. A transparent conductive film material such as indium zinc oxide (IZO) and indium tin oxide (ITO) can be equipped with a high-energy ion source by using an ion-beam assisted sputtering system. The substrate is cleaned and modified during the coating process to obtain better film adhesion. This ion-assisted mechanism can also be used as an auxiliary energy to increase the atomic kinetic energy of the coating, so that the deposited film forms a high-density, high-uniformity and continuous microstructure structure.

The process for forming a transparent antenna of the present invention can form a thin film structure at a low temperature. For example, the film can be formed at room temperature and its transmittance can be higher than 82%. The process temperature can be controlled from room temperature to 200 degrees. If PET is used as a soft substrate, it can be fabricated at room temperature, reducing process cost. The second figure shows the manufacturing process of the present invention. First, the target 102 is disposed in the cavity 100, and the air pressure of the cavity is pumped by the vacuum pump 114 to lower the air pressure to a preset vacuum to facilitate the reduction of impurities. Step 200 . Accordingly, if desired, step 205 introduces the desired gas, followed by physical vapor deposition, sputtering or evaporation process 210 to produce particles or gases forming the antenna within the cavity, utilizing the spindle to spindle device 106 to actuate the substrate. The material moves horizontally, and the speed of the substrate can be controlled by controlling the speed of the shaft. The material of the antenna will be deposited or laid on the surface of the substrate, step 215. Therefore, the present invention can deposit a large amount of deposition, evaporation or sputtering on the planar moving substrate which is driven by the rotating shaft to the rotary shaft device 106. As the process progresses, the substrate is transferred from one of the undeposited ends to the other end, at which point the substrate from which the deposition or sputtering of the antenna material has been completed will be wound to the end. Since the substrate to be used has flexibility, it can be crimped to the other end. If necessary, the heating device can be turned on to provide the thermal energy required for the antenna film, step 220 or to raise the surface energy of the antenna film 205. The substrate having the antenna film can then be transferred to the buffer chamber and then lifted to atmospheric pressure (step 235) or directly raised to atmospheric pressure (step 230). At this time, the roll of the antenna film has been completed, and then the roll of the antenna film can be unrolled by a machine to cut or emboss the desired antenna pattern, or can be formed by etching or laser cutting. Antenna pattern, step 240. If necessary, a buffer layer can be applied to the soft substrate.

The invention can use a non-metal material as the antenna. The use of non-metallic materials will make the device lighter, smaller, lower cost, and a large number of batch processes. The non-metallic antenna here means that the antenna body does not use metal raw materials, and does not contain metal additives or particles. By using the flexible substrate, the material can be made into a large number of antenna films through the rotating shaft to the rotating shaft device of the present invention, without plating solution, and the process does not pollute the environment. Moreover, the thickness of the film is controlled by the speed of the driving shaft, and the period of the film antenna is flexible so that it can adhere to an irregular or uneven surface. In addition, the conventional antenna of the handheld device is disposed on the printed circuit board, so that it is easy to cause interference with the electronic components. However, the antenna can be removed from the board in accordance with the present invention. If it is transparent, it can be attached to a screen or glass or outer surface. The antenna is attached to the inner surface or the outer surface of the handle device housing, and a shielding structure can be formed between the antenna and the circuit board to avoid mutual interference between the antenna and the circuit board component.

The antenna can be made of a conductive polymer or a carbon nanotube. The conductive polymer may be selected from the group consisting of thiophenes, selenophenes, tellurophenes, pyrroles, anilines, and polycyclic aromatics, and the polymer may include, but is not limited to, polythiophenes, poly(selenophenes), poly(tellurophenes), polypyrroles, polyanilines, polycyclic aromatic polymers, and the like. U.S. Patent Application No. 20080017852 to Huh; Dal Ho et al., entitled "Conductive Polymer Composition Comprising Organic Ionic Salt and Optoelectronic Device Using the Same" discloses a method of making a conductive polymer. In still another embodiment, the conductive polymer is an organic polymer semiconductor or an organic semiconductor. Conductive polyacetylenes include polyacetylene, polypyrrole, polyaniline and their derivatives. Conductive organic polymers typically have extended delocalized bonds, which result in a band structure similar to 矽 but with localized states. This zero-band gap conductive polymer has a metalloid behavior. The carbon tube may comprise a multi-layered double-walled carbon tube, a single-layer carbon tube; it may be referred to in the literature: Young's modulus in the low TPa range and tensile strengths in excess of 37 GPa, please refer to the Articles: Yakobson et al., Phys. Rev. Lett. 1996, 76, 2411; Lourie et al., J. Mater. Res. 1998, 13, 2418; lijima et al., J. Chem. Phys. 1996, 104, 2089. Generally, CNTs contain interdigitated nanofibers to form mutually entangled carbon nanotubes. One of the methods for forming the above-mentioned carbon nanotubes is that infusion organic molecules penetrate tangled CNTs, thereby causing nanonetworks (nanopipe networks). ). The polymerization and subsequent heat treatment of the organic molecules to produce interlaced network structures or nanofibers.

The method of forming an antenna film such as indium tin oxide in this embodiment can be formed in a humid air at room temperature based on cost considerations for manufacturing. After the film is formed or patterned, heat treatment is performed at a temperature between 50 degrees Celsius and 220 degrees Celsius to reduce the electrical resistance of the film and increase its transmittance. Referring to the third and fourth figures in this embodiment, first, an indium tin oxide or zinc oxide solution 400 is prepared, and the material powder can be obtained by dilution in an alcohol/water mixed solvent, and the temperature of the heat treatment is higher than that of Celsius. , heat treatment is implemented. A diluent such as ferrous sulfate, trisodium citrate, tartaric acid, or sodium boron hydride may be added during the dilution process. The apparatus of this embodiment is similar to the first and second figures, except that in this embodiment, a solution, spray or inkjet print is applied to apply the solution to a desired soft substrate. After the solution is prepared, the inkjet, spray, printing or coating process 410 is initiated to distribute the material over the soft substrate 415. If the inkjet print is used, the antenna pattern can be directly sprayed onto the flexible substrate. The remaining steps are similar to the above embodiment, including selective heating 420, lifting surface energy 425, and then cutting to fabricate the antenna unit. The conductive film can be obtained by applying the above liquid to the substrate and drying it to obtain a transparent film. The metal solution is prepared by mixing a dispersant.

For those skilled in the art, this creation is illustrated by better examples. However, it is not intended to limit the spirit of this creation. Modifications and similar configurations made without departing from the spirit and scope of the present invention are intended to be included in the scope of the appended claims.

100‧‧‧ cavity

102‧‧‧ Targets

102A‧‧‧solution

104‧‧‧Energy source

106‧‧‧Rotary shaft to rotary shaft device

108‧‧‧heater

110‧‧‧Substrate

112‧‧‧ particles

114‧‧‧vacuum pump

116‧‧‧ gas discharge

118‧‧‧ gas inlet

200‧‧‧Reducing cavity pressure

205‧‧‧Introduction of gas

210‧‧‧Starting the physical vapor deposition process

215‧‧‧Delayed antenna material on a rotating shaft substrate

220‧‧‧Selective heating antenna material

225‧‧‧Raise the surface energy of the antenna material

230‧‧‧Uplifting chamber pressure

235‧‧‧Transfer to the buffer cavity

240‧‧‧Antenna pattern forming

400‧‧‧Preparation solution

410‧‧‧Start spraying procedure

415‧‧‧ coated antenna material on a rotating shaft substrate

420‧‧‧Selective heating antenna material

425‧‧‧Raise the surface energy of the antenna material

430‧‧‧Antenna patterning

The first figure is an antenna making device of the present invention.

The second figure is a method of fabricating the antenna of the present invention.

The third figure is the antenna manufacturing apparatus of the present invention.

The fourth figure is a method of fabricating the antenna of the present invention.

100. . . Cavity

102. . . Target

104. . . Energy source

106. . . Rotary shaft to rotary shaft device

108. . . Heater

110. . . Substrate

112. . . particle

114. . . Vacuum pump

116. . . Gas discharge

118. . . Gas inlet

Claims (9)

A method for fabricating a thin film antenna, comprising: preparing a mixture of a conductive polymer and a carbon nanotube; and driving the substrate to move by a rotating shaft to a rotating shaft device, wherein the substrate is horizontally moved by a rotating shaft to a rotating shaft device to facilitate the antenna Forming a film on the substrate, forming an antenna film on the driven substrate by inkjet; providing thermal energy of the antenna film by a heating device to increase surface energy of the antenna film; applying mechanical force, etching or laser to The antenna film is used to form an antenna pattern. The method for fabricating a film antenna according to claim 1, wherein the antenna film comprises one or a combination of the following groups: gold, zinc, silver, palladium, platinum, rhodium, iridium, copper, iron, nickel. , cobalt, tin, titanium, indium, aluminum, antimony, gallium, antimony and antimony. The method of fabricating a thin film antenna according to claim 1, wherein the antenna film comprises indium tin oxide or indium zinc oxide. The method for fabricating a film antenna according to claim 1, which comprises containing PET, PC, PVC, PI or PMMA to the substrate. The method of fabricating a thin film antenna according to claim 1, comprising forming a buffer layer between the substrate and the antenna film. A method for fabricating a thin film antenna, characterized in that: preparing a conductive high score a mixture with a carbon nanotube; providing a soft substrate having an antenna film attached thereto, wherein the antenna film drives the soft substrate to move horizontally by a shaft-to-axis device, and evacuates with a vacuum pump to reduce impurities The antenna film on the soft substrate is made by evaporation, sputtering, inkjet or spraying; the heating device provides thermal energy of the antenna film to increase the surface energy of the antenna film; and is applied by mechanical force, etching or laser The antenna film is used to form an antenna pattern; wherein the soft substrate comprises PET, PC, PVC, PI or PMMA. The method for fabricating a film antenna according to claim 6, wherein the antenna film comprises one or a combination of the following groups: gold, zinc, silver, palladium, platinum, rhodium, iridium, copper, iron, Nickel, cobalt, tin, titanium, indium, aluminum, antimony, gallium, antimony and antimony. The method for fabricating a thin film antenna according to the invention of claim 6, wherein the antenna film is indium tin oxide or indium zinc oxide. The method for fabricating a thin film antenna according to the invention of claim 6, comprising forming a buffer layer between the soft substrate and the antenna film.