Showing papers on "Flexible electronics published in 2004"

Wide-bandgap high-mobility ZnO thin-film transistors produced at room temperature

Abstract: We report high-performance ZnO thin-film transistor (ZnO-TFT) fabricated by rf magnetron sputtering at room temperature with a bottom gate configuration. The ZnO-TFT operates in the enhancement mode with a threshold voltage of 19V, a saturation mobility of 27cm2∕Vs, a gate voltage swing of 1.39V∕decade and an on/off ratio of 3×105. The ZnO-TFT presents an average optical transmission (including the glass substrate) of 80% in the visible part of the spectrum. The combination of transparency, high mobility, and room-temperature processing makes the ZnO-TFT a very promising low-cost optoelectronic device for the next generation of invisible and flexible electronics.

Engineered Films for Display Technologies

Abstract: Flexible displays and flexible electronics is an area generating considerable interest at present. This article will discuss the requirements of a base substrate for flexible displays and contrast the plastic films that are being developed for this application. The review will cover how the surfaces and properties of the films are being engineered to make them suitable for laying down barrier coatings and for laying down thin film transistor arrays. The barrier technologies that are being developed and the issues facing the development of a “flexible glass” will be discussed.

High field-effect mobility zinc oxide thin film transistors produced at room temperature

Abstract: In this paper we present the first results of thin film transistors produced completely at room temperature using ZnO as the active channel and silicon oxynitride as the gate dielectric. The ZnO-based thin film transistors (ZnO-TFT) present an average optical transmission (including the glass substrate) of 84% in the visible part of the spectrum. The ZnO-TFT operates in the enhancement mode with a threshold voltage of 1.8 V. A field effect mobility of 70 cm 2 /V s, a gate voltage swing of 0.68 V/decade and an on-off ratio of 5 × 10 5 were obtained. The combination of transparency, high field-effect mobility and room temperature processing makes the ZnO-TFT very promising for the next generation of invisible and flexible electronics.

Flexible touch-sense switch

Abstract: A flexible touch-sense switch includes a force sensitive composite and an at least one proximity sensor. The force sensitive composite includes a plurality of force sensors disposed between a first layer and a second layer of polymide film defining a displacement region. The at least one proximity sensor generates an electromagnetic field that defines a detection region. The force sensitive composite and the at least one proximity sensor are mounted to the first layer of the polymide film for forming a flexible printed circuit board. A control circuit is electrically connected to the force sensitive composite and the at least one proximity sensor for selectively controlling the touch-sense switch activation in response to coincident actuation thereof.

Electro-optical apparatus, flexible printed circuit board, manufacturing method for electro-optical apparatus, and electronic equipment

Abstract: An electro-optical apparatus comprising an electro-optical panel including a display section, a flexible printed circuit board, and a rigid circuit board. The flexible printed circuit board includes a first terminal connected to the electro-optical panel and a second terminal connected to an external circuit. The rigid circuit board includes a first surface on which electronic components are mounted and a second surface mounted to the flexible printed circuit board. The second surface of the rigid circuit board is opposite to the first surface. An entirety of the rigid circuit board is stacked on the flexible printed circuit board within the flexible printed circuit board. The rigid circuit board is electrically connected to the flexible printed circuit board. The flexible printed circuit board is bent toward the external circuit.

Flexible light array and fabrication procedure thereof

Abstract: A flexible light array is constructed to have a flexible substrate with conducting circuits therein, a LED array formed of longitudinally and transversely aligned light emitting diodes respectively electrically connected to the conducting circuits and controllable by a driving circuit to produce a video display, and a flexible plastic member packed on the flexible substrate and the LED array.

Flexible printed circuit board and liquid crystal display having the same

Abstract: PURPOSE: A flexible printed circuit board(PCB) and an LCD(Liquid Crystal Display) having the same are provided to reduce the number of contact regions for electrically connecting input wires and output wires, thereby reducing the size of the flexible PCB and the entire size of the LCD. CONSTITUTION: The flexible PCB(100) includes a base film(110), input wires(120) and output wires(140). The base film(110) includes an input portion(I) arranged an end portion of the input wires(120) and an output portion(O) arranged an end portion of the output wires(140) and is made of a flexible polyimide resin having an insulating characteristic. The output wires(140) are electrically connected to the input wires(120). The respective output wires(140) include the first and second output terminals(141,142). The first driving IC is connected to the first output terminal(141) and the second driving IC is connected to the second output terminals(142).

Semiconductor device and semiconductor module

Abstract: A semiconductor device includes a flexible printed circuit board which is formed into a cylindrical shape so that a heat releasing space is formed therein, a plurality of semiconductor elements which are mounted on the inner surface of the flexible printed circuit board via inner bumps, and an external electrode (external terminal) which is provided on the flexible printed circuit board and which connects a wire on the flexible printed circuit board to an external wire on a mounting board. Herein, the heat releasing space is provided with a cooler for cooling the space.

A comprehensive study of ion track enabled high aspect ratio microstructures in flexible circuit boards

Abstract: A process to form deep, vertical and high aspect ratio microstructures of solid as well as porous nature is presented. The process is capable of producing regions with perpendicular sub-micron metal wire connections, with a regulated effective metal density at numerous, arbitrarily specified locations. The structures are created in a two-metallic-layer polyimide laminate, i.e. a flexible printed circuit board. The high aspect ratio of the process is indebted to ion track technology. The laminate is irradiated with heavy ions creating a vertical damage anisotropy (individual ion tracks) in the polymer layer. Apertures in the front metallic layer define the geometry and the positions of the vertically projected structures. The tracks are selectively developed forming nanometer wide pores, which after prolonged etching grow in diameter and eventually merge creating fully opened cavities. Metallic structures have been replicated in these pores/cavities by electrodeposition of nickel and copper. We have fabricated open and dense clusters of separated micron or sub-micron sized wires as well as solid structures. Highly vertical, through hole microvias in average 39 μm wide, with a pitch of 100 μm have been fabricated. The smallest structures obtained were 25 × 25 μm square columns. The process appears promising for ultra-high density via batch production and has a strong potential of further miniaturising via dimensions.

Flat display panel and assembly process or driver components in flat display panel

Abstract: A flat display panel comprises a plurality of driver ICs and one or more flexible printed circuit, a plurality of common wires formed on the substrate to electrically connect the ICs to the one or more flexible printed circuit, and at least one anisotropic conductive film that connects respective connecting terminals of the driver ICs and flexible printed circuit to terminals pads of the common wires. The anisotropic conductive film is laminated over the substrate to cover the terminal pads. The driver ICs and flexible printed circuit are aligned and attached on the anisotropic conductive layer by thermocompression bonding.

Image sensor package module with a leadless leadframe between chips

Abstract: An image sensor package module with a leadless leadframe between chips includes a chip carrier, an image sensor chip, an integrated circuit chip, and a flexible printed circuit board. The chip carrier comprises a leadless leadframe and a pre-molded body. The leadless leadframe has a plurality of leads. The pre-molded body is completely filled among the leads and has a dam on the upper surfaces of the leads. The upper surfaces and lower surfaces of the leads are exposed on the pre-molded body. The image sensor chip is attached to the chip carrier inside the dam and electrically connected to the upper surfaces of the leads. The integrated circuit chip is mounted on the lower surfaces of the leads via bumps. The flexible printed circuit board is electrically connected to the leads for signal transmission.

Optical module, method of manufacturing the same, optical communication device and electronic device using the same

Abstract: The invention provides an optical module that can reduce its cost. An optical module to which an optical fiber is detachably inserted, includes: a substrate with an aperture to which the optical fiber is inserted; a flexible printed circuit board disposed on one surface of the substrate and including: a base member with an opening in a corresponding location to the aperture; an interconnection layer disposed on at least one surface of the base member); and a connection section including a part of the interconnection layer exposed through the opening; and an optical element disposed within the opening of the flexible printed circuit board, and connected to the connection section, the optical element performing one of transmission and reception of an optical signal with the optical fiber.

Fiber optic transceiver module with rigid and flexible circuit boards

Abstract: An optical transceiver for converting and coupling an information-containing electrical signal with an optical fiber includes a housing and coupled rigid and flex printed circuit boards. The housing includes a fiber optic connector adapted for coupling with an external optical fiber for transmitting and/or receiving an optical communications signal. The rigid printed circuit board is within the housing and includes an electrical connector for coupling with an external electrical cable or information system device, and for transmitting and/or receiving an information-containing electrical communications signal. A first interface connector is for receiving or transferring the electrical signal. A flexible printed circuit board is also within the housing and coupled to the rigid printed circuit board, including a second interface connector for mating with the first interface connector, and transmitting or receiving the electrical signal to or from the rigid printed circuit board. An electro-optical subassembly on the flex board is for converting between an electrical signal and a modulated optical signal. The flex board is adapted for coupling to the fiber optic connector.

Flexible printed circuit board unit contributing to reliable soldering and suppression of increased temperature

Abstract: A thermal component is mounted on the front surface of an isolator sheet within a first specific area. A thermally-conductive material is located on the back surface of the isolator sheet on the back of the first specific area. An electrically-conductive material is located on the front surface of the isolator sheet within a second specific area. A thermally-insulating material is located on the back surface of the isolator sheet on the back of the second specific area. The flexible printed circuit board unit of this type allows heat of the thermal component to efficiently radiate from the thermally-conductive material. An increase in temperature can be suppressed in the thermal component. Heat can reliably stay in the electrically-conductive material when a solder material is applied to the surface of the electrically-conductive material. The solder material is allowed to reliably fuse.

Manufacturing method of flexible printed circuit board

Abstract: PROBLEM TO BE SOLVED: To provide a manufacturing method of a flexible printed circuit board capable of increasing the adhesion of both side plating and through hole plating and reliability in continuity. SOLUTION: Wet blast treatment, short-wave ultraviolet-ray treatment and activation treatment using an alkali metal hydroxide are sequentially applied on both surfaces of a polyimide resin film and the inner circumferential surface of the through hole, prior to electroless plating after the through hole for a through-hole plating is formed in the polyimide resin film. Electroless plating is applied to nickel or a nickel alloy to apply copper electroplating on the surface of the electroless plated layer. COPYRIGHT: (C)2006,JPO&NCIPI

Flexible electronics for space applications

Abstract: NASA is currently developing a host of deployable structures for the exploration of space. These include balloons, solar sails, space-borne telescopes and membrane-based synthetic aperture radar. Each of these applications is driven by the need for a thin, low mass, large area structure (e.g., polymer-based) which could not be implemented using conventional engineering materials such as metals and alloys. In each case, there is also the need to integrate sensing and control electronics within the structure. However, conventional silicon-based electronics are difficult to integrate with such large, thin structures, due to a variety of concerns including mass, reliability and manufacturing issues. Flexible electronics, particularly thin film transistors (TFTs), are a potentially key enabling technology that may allow the integration of a wide range of sensors and actuators into these types of structures. There are numerous challenges, however, regarding the survivability of such devices during stowage and deployment of the structure, as well as during operation in the harsh environments of space. We have fabricated TFTs on polyimide substrates, and are investigating the durability of these devices with respect to relevant space environments. We are also developing flexible sensor technologies for the integration of distributed sensor networks on large area structures.

Liquid crystal module

Abstract: A liquid crystal module has a liquid crystal panel and a flexible printed circuit board. The liquid crystal panel has a substrate and an indium tin oxide (ITO) film on the substrate. A flexible printed circuit board has an insulating layer on which a lower conductive layer, a second protective layer, an upper conductive layer and a first protective layer are stacked in sequence. The lower conductive layer is electrically connected to predetermined portions of the lower conductive layer and has a conductive portion, which is unshielded by the insulating layer. The flexible printed circuit board is bonded to the liquid crystal panel with the insulting layer stacked on the indium tin oxide film and the pins of the indium tin oxide film electrically connected to the conductive portion of the lower conductive layer.

Electronic device with flexible printed circuit board structure

Abstract: An electronic device with flexible printed circuit board structure. The electronic device includes a first flexible printed circuit board and a second flexible printed circuit board. The first flexible printed circuit board has a first bent portion. The second flexible printed circuit board has a second bent portion penetrating the first bent portion as the first and the second flexible printed circuit boards are bent simultaneously.

Signal transmission device

Abstract: A signal transmission device The signal transmission device comprises a first and a second flexible printed circuit boards, connecting an display module and a system The first flexible printed circuit board electrically connects the display module and the system The second flexible printed circuit board electrically connects the display module and the first flexible printed circuit board, wherein the first and second flexible printed circuit boards are joined by hot bar soldering or anisotropic conductive film (ACF) bonding

Liquid crystal display device with flexible printed circuitboard

Abstract: A liquid crystal display device has a liquid crystal panel displaying an image A printed circuit board is arranged along one side of the liquid crystal panel, and a plurality of flexible printed circuit boards connect the liquid crystal panel and the printed circuit board At least two driver ICs are mounted on each flexible printed circuit board and the at least two driver ICs are cascaded with respect to input signals

Z-axis electrical connection and methods for ultrasound transducers

Abstract: Electrical connection is provided in a transducer stack through a backing block. A flexible circuit is sandwiched between pieces of acoustic attenuating material. For example, 2 to 200 or more flexible circuits are stacked in alternating layers with pieces of acoustically attenuating material. The alternating layers are then connected together to form a backing block with Z-axis electrical connection. The top surface of the connected backing block includes a plurality of exposed electrical traces from the flex circuit. Since flex circuits are used, the electrical traces are precisely aligned along one dimension. Since pre-formed acoustic attenuating material pieces are used, precise alignment is provided along a second or orthogonal dimension. The substrate holding the electrical traces in the flexible circuits provides more stability and allows for easier connection to circuit boards as compared to individual strips of metal.

Method for mounting a driver IC chip and a FPC board/TCP/COF device using a single anisotropic conductive film

Abstract: A method for bonding integrated circuit chips and other devices to a liquid crystal display panel. The method involves using a single anisotropic conductive film that is sized to bond at least one integrated circuit chip and at least one other device, such as a flexible printed circuit board, a tape carrier package and a chip-on-film, to the liquid crystal display panel.

Imaging device and mobile terminal using this imaging device

Abstract: An imaging device mountable on a small mobile terminal such as a mobile phone. On a side of a flexible printed circuit board (FPC) having an opening (20) at a predetermined position, an imaging element (2) is so provided that at least a part of the opening is closed and an imaging area is exposed. The imaging element is connected by flip-chip mounting. On the other side of the flexible printed circuit board a reinforcing member (10) made of a material of a coefficient of linear expansion of less than 1×10-5 (cm/cm/°C) is attached to reinforce the flexible printed circuit board. Thus an imaging device (100) having superior resistance against the heat shock when the imaging element is connected and the heat shock when the mobile terminal device incorporating the imaging element is used is provided.

P-86: Flexible Transparent Circuits from Carbon Nanotubes

Abstract: Flexible, transparent circuits can be formed from carbon nanotube dispersions combined with polymeric binders, using wet coating and printing. Coatings exhibit significantly greater flex endurance and abrasion resistance than ITO. Structure / properties are described, including optical transparency, conductivity, flex and abrasion testing. Methods for fabricating circuits are also discussed.

Conducting metal nano particle and nano-metal ink containing it

Abstract: The present invention relates to conductive metal nano particles and an nano-metal ink comprising the same, and more particularly, conductive metal nano particles comprising a metal and a hydrocarbon containing a carboxyl group, a production method thereof, a nano-metal ink comprising the conductive nano particles and a method for preparing printed circuit board using the nano-metal ink. According to the present invention, it is possible to laminate both the production of copper clad laminate (CCL) to bond a copper foil to a film and lithography process and simplify the production process by directly printing a wiring on a resin film in a single process and considerably reduce the manufacture cost and produce highly integrated and highly effective printed circuit board through miniaturization of line width in the printed circuit board. According to the present invention, in formation of a wiring on a flexible printed circuit board (FPCB) used in electronic appliances and electrical equipment such as mobile phones, PDA, notebook computers and the like or a wiring of a general appliance, the printed circuit board (PCB) or flexible printed circuit board (FPCB), metal nano-particles for forming the wiring is prepared, the metal nano-particles are converted into ink, which is then printed. The printed circuit board(PCB) or flexible printed circuit board IBPCB) prepared by a novel method is applied to electric and electronic appliances for industrial, official or house hold.

Anisotropically conductive adhesive, mounting method, electro-optical device module, and electronic device

Abstract: This invention provides a mounting method for reliably connecting mounting components electrically. Specifically, an anisotropically conductive adhesive can be composed of crushable microcapsules and a second liquid in which the microcapsules are dispersed. Each microcapsule encloses a first liquid and a conductive particle. The first liquid can react with the second liquid at normal temperatures to cure the second liquid. This anisotropically conductive adhesive can be applied on a flexible printed circuit (FPC). Then, a drive IC is mounted and pressed on the FPC to crush the microcapsules between electrode pads provided on the drive IC and electrode pads provided on the FPC, thereby bonding the electrode pads. Subsequently, the anisotropically conductive adhesive is heated to plasticize a capsule wall of each microcapsule, thereby bonding the drive IC and the FPC.

Flat and thin connector for electrically connecting a flexible printed circuit board and a hard board

Abstract: A flat and thin connector for electrically connecting a flexible printed circuit board and a hard board. The connector includes a mounting member fixed to the hard board, and a pusher member cooperating with said mounting member. The pusher member urges the printed circuit board against the hard board by aid of an elastic member. Further, the printed circuit board is provided with slits between the bump contacts to facilitate a uniform pushing force.

Correlation of silver migration to the pull out strength of silver wire embedded in an adhesive matrix

Abstract: The substantial growth in electronics industry has created a need for environmental and user friendly alternatives to tin / lead (Sd/Pb) solders for attaching encapsulated surface mount components on rigid and flexible printed circuit boards. Electronically Conductive Adhesives (ECAs) have been explored in this manner to establish mechanical as well as electrical joints between printed circuit board and surface mount components. Applications of conductive adhesive are limited due to serious concerns associated with the long-term reliability data of current commercial ECAs. One critical concern in wire bonding applications is the significant decrease in the bond strength and consequent loss of the conducting properties of adhesive due to silver migration. In this study an effort is made to understand and model long-term silver migration phenomenon with respect to different parameters (duration of the migration, dry and wet conditions), and pull-out strength of silver wire embedded in an epoxy adhesive matrix. Morphology of embedded silver wire after migration and pull-out was also studied using scanning electron micrographs. Migration area increased with the duration of migration, and reduction in the pull-out strength was significant in wet condition as compared to dry condition. The increase in migration area was consistent with the reduction in pull-out strength in both wet and dry conditions.