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Showing papers on "Flexible electronics published in 2003"


Journal ArticleDOI
TL;DR: In this paper, the authors fabricated ZnO thin-film transistors by rf magnetron sputtering on Si substrates held near room temperature, and the best devices had field effect mobility of more than 2 cm2/V and an on/off ratio>106.
Abstract: We fabricated ZnO thin-film transistors by rf magnetron sputtering on Si substrates held near room temperature. The best devices had field-effect mobility of more than 2 cm2/V s and an on/off ratio>106. These ZnO films had resistivity ∼105 ohm cm, with high optical transparency (>80% for wavelength >400 nm), and compressive stress <0.5 GPa. The combination of transparency in the visible, excellent transistor characteristics, and low-temperature processing makes ZnO thin-film transistors attractive for flexible electronics on temperature sensitive substrates.

1,115 citations


Journal ArticleDOI
TL;DR: In this article, the size of the nanoparticle and the length of the alkanethiol encapsulant were optimized to produce plastic-compatible gold conductors for the first time.
Abstract: Low resistance conductors are crucial for the development of ultra-low-cost electronic systems such as radio frequency identification tags. Low resistance conductors are required to enable the fabrication of high- Q inductors, capacitors, tuned circuits, and interconnects. The fabrication of these circuits by printing will enable a dramatic reduction in cost, through the elimination of lithography, vacuum processing, and the need for high-cost substrates. Solutions of organic-encapsulated gold nanoparticles many be printed and subsequently annealed to form low resistance conductor patterns. We describe a process to form the same, and discuss the optimization of the process to demonstrate plastic-compatible gold conductors for the first time. By optimizing both the size of the nanoparticle and the length of the alkanethiol encapsulant, it is possible to produce particles that anneal at low temperatures (,150°C) to form continuous gold films having low resistivity. We demonstrate the printing of these materials using

522 citations


Journal ArticleDOI
TL;DR: A crystalline titanyl phthalocyanine having diffraction peaks at least at 7.4 DEG and 9.7 DEG with one of the diffraction Peaks being the maximum is described.
Abstract: The merger of nanoscale building blocks with flexible and/or low cost substrates could enable the development of high-performance electronic and photonic devices with the potential to impact a broad spectrum of applications. Here we demonstrate that high-quality, single-crystal nanowires can be assembled onto inexpensive glass and flexible plastic substrates to create basic transistor and light-emitting diode devices. In our approach, the high-temperature synthesis of single-crystal nanowires is separated from ambient-temperature solution-based assembly to enable the fabrication of single-crystal-like devices on virtually any substrate. Silicon nanowire field-effect transistors were assembled on glass and plastic substrates and display device parameters rivaling those of single-crystal silicon and exceeding those of state-of-the-art amorphous silicon and organic transistors currently used for flexible electronics on plastic substrates. Nanowire transistor devices have been configured as low-threshold logi...

368 citations


Patent
10 Mar 2003
TL;DR: A flexible interconnect structure (10) as discussed by the authors allows for rapid dissipation of heat generated from an electrical device that includes light-emitting elements (300), such as lightemitting diodes ('LEDs') and/or laser Diodes.
Abstract: A flexible interconnect structure (10) allows for rapid dissipation of heat generated from an electrical device that includes light-emitting elements (300), such as light-emitting diodes ('LEDs') and/or laser diodes. The flexible interconnect structure (10) comprises: (1) at least one flexible dielectric film (20) on which circuit traces (40) and, optionally, electrical circuit components (30, 32, 34, 36, 38) are formed and at least a portion of which is removed through its thickness; and (2) at least a heat sink (100) attached to one surface of the flexible dielectric film (20) opposite to the surface on which circuit traces (40) are formed. The flexible interconnect structure can include a plurality of such flexible dielectric films (20), each supporting circuit traces (40) and/or circuit components (30, 32, 34, 36, 38) and each being attached to another by an electrically insulating layer (70). Electrical devices or light sources having complex shapes are formed from such flexible interconnect structures and light-emitting elements (300) attached to the heat sinks (100) so to be in thermal contact therewith.

250 citations



Journal ArticleDOI
TL;DR: In this article, field effect transistors using poly(triaryl amine) p-channel organic semiconductor in conjunction with anodised aluminium oxide as the gate insulator (Al2O3 on Al) are demonstrated.

117 citations


Journal ArticleDOI
TL;DR: In this paper, the development of flexible shear-stress sensor skin and its application on the detection of leading edge flow separation for delta plan-form UAVs is described.
Abstract: Shear-stress information is of great interest for many fluidic dynamic monitoring/diagnostics application. To obtain such information on non-planar surfaces has long been a significant challenge. This paper describes the development of flexible shear-stress sensor skin and its application on the detection of leading edge flow separation for delta planform unmanned aerial vehicles (UAVs). The sensor skin contains a 1-D array of 36 shear-stress sensors, which can cover the 180° surface of the 1.27 cm diameter semicylindrical UAV leading edge with 5° resolution. The implementation process of the sensor skin is significantly simplified by a packaging scheme based on solder bonding and flexible printed circuit board (PCB). The flexible shear-stress sensor skin in both wind tunnel and real flight tests detected the flow separation along the leading edge successfully.

114 citations


Patent
09 Apr 2003
TL;DR: In this paper, the authors propose a two-dimensional configuration of the high-speed data pad and traces and adjacent ground pads and traces to maintain a desired impedance in the flexible circuit and at the transition from a flexible circuit to a printed circuit board.
Abstract: Flexible printed circuit boards interconnect to adjacent electronic devices through one or more of high speed data, low speed data, high current, and ground lines and pads. The design of the high speed data pads and traces and adjacent ground pads and traces maintains a desired impedance in the flexible circuit and at the transition from the flexible circuit to a printed circuit board, a ceramic header, or other device to ensure high speed operation. The pads are preferably arranged in a two dimensional geometry such that a connecting area of the flexible circuit is narrower than it would preferably be if the pads were arranged linearly. The two dimensional array also allows the use of the high current thermoelectric cooler pads, which require large surface areas that may otherwise not fit in a conventional linear array.

72 citations


Patent
27 Jun 2003
TL;DR: In this article, a method for manufacturing low cost electroluminescent illuminated membrane switches is disclosed, which includes the first step of die cutting, embossing or chemically etching the metal foil surface of a metal foil bonded, light transmitting flexible electrical insulation to simultaneously form one or more front capacitive electrodes, membrane switch contacts and electrical shunt, electrical distribution means and electrical terminations that together comprise a flexible printed circuit panel.
Abstract: A method for manufacturing low cost electroluminescent (EL) illuminated membrane switches is disclosed. The method includes the first step of die cutting, embossing or chemically etching the metal foil surface of a metal foil bonded, light transmitting flexible electrical insulation to simultaneously form one or more front capacitive electrodes, membrane switch contacts and electrical shunt, electrical distribution means and electrical terminations that together comprise a flexible printed circuit panel. This continuous flexible printed circuit substrate is then coupled to a precisely positioned indexing system. Next, the front metal foil capacitive electrodes are coated with a light transmissive electrically conductive layer. Then, a layer of electroluminescent phosphor is applied to the electrically conductive layer, a layer of capacitive dielectric is applied insulating the phosphor layer, a rear capacitive electrode is then applied over the capacitive dielectric layer, thus forming an electroluminescent lamp portion. Next, a transparent dielectric coating is applied to the entire surface of the lamp and substrate with open portions exposing electrical terminations, switch contacts and shunt. A spacer is applied to surround the switch shunt, providing an isolation barrier. An intermediary material is applied to the surface of the isolated rear EL electrode thus forming a switch actuator. Finally, the illuminated switch pattern is die-cut from the substrate material, and is then folded into three layers forming the final illuminated membrane switch.

63 citations


Journal ArticleDOI
TL;DR: In this paper, a 3D flexible circuit was fabricated by combining nano-and microtechnology, where clusters of nanowires form the vertical via connections. But the circuit structure is in essence a magnetic field sensor since the wires are made of nickel, a magnetoresistive material.
Abstract: By combining nano- and microtechnology we have fabricated three-dimensional (3D) flexible circuits, where clusters of nanowires form the vertical via connections. The nanowires, embedded in foils of polyimide plastic, are interconnected with two lithographically structured metallic surface layers. As the wires are defined by ion track technology they are stochastically distributed with a uniform density in macro-scale. In addition they are highly parallel in well-defined directions in the foil. The key structural element is a junction where overlapping lateral interconnection lines on the surface intersect with clusters of perpendicular or tilted wires. The demonstrated circuit structure is in essence a magnetic field sensor since the wires are made of nickel, a magnetoresistive material. The essential fabrication process comprises: ion track generation by means of heavy ion irradiation, selective ion track etching, electrodeposition of nanowires, and double-sided photolithography. The polyimide, employed commercially in, e.g. flexible printed circuit boards, is for the first time evaluated as a carrier for nanowires. The chemical properties and temperature stability makes the polyimide an appropriate material for implementation of electronic circuitry by ion- and photolithography.

55 citations


Patent
08 Oct 2003
TL;DR: In this article, a modularized probe head for modularly assembling on a probe card is configured for probing a semiconductor wafer under test, which includes a silicon substrate having an active surface and an opposing back surface.
Abstract: A modularized probe head for modularly assembling on a probe card is configured for probing a semiconductor wafer under test. The probe head includes a silicon substrate having an active surface and an opposing back surface. The back surface of the silicon substrate is attached on a holder. The silicon substrate has a plurality of peripheral bond pads and contact pads on its active surface. At least a probing chip is mounted on the active surface of the silicon substrate. The probing chip has probing tips and side electrodes. The side electrodes are connected with the contact pads by means of solder material. The peripheral bonding pads of the silicon substrate are connected with a flexible printed circuit for electrically connecting to a multi-layer printed circuit board of a probe card.

Journal ArticleDOI
TL;DR: In this article, a novel approach for cost effective fabrication, assembly, and packaging of radio-frequency microelectromechanical systems (RF MEMS) capacitive switches using flexible circuit processing techniques is reported.
Abstract: A novel approach for cost effective fabrication, assembly, and packaging of radio-frequency microelectromechanical systems (RF MEMS) capacitive switches using flexible circuit processing techniques is reported. The key feature of this approach is the use of most commonly used flexible circuit film, Kapton-E polyimide film, as the movable switch membrane. The physical dimensions of these switches are in the mesoscale range. For example, electrode area and gap height of a capacitive shunt switch on coplanar waveguide are 2 /spl times/ 1 mm/sup 2/ and 43 /spl mu/m, respectively. Pull-down voltage is in the range of 90-100 V. In the ON state (up-position), the insertion loss is less than 0.3-0.4 dB up to 30 GHz. In OFF state (down-position), the isolation value is about 15 dB at 12 GHz and increases to 36 dB at 30 GHz. These switches are uniquely suitable for batch integration with printed circuits and antennas on laminate substrates.

Patent
26 Sep 2003
TL;DR: In this article, a plurality of lands and conducting wires connected independently to each land are formed on one side surface of an insulating substrate of a flexible printed circuit board, and through-holes are formed through the insulating surface for exposing the lands to the other side surface.
Abstract: A plurality of lands and a plurality of conducting wires connected independently to each land are formed on one side surface of an insulating substrate of a flexible printed circuit board. Through-holes are formed through the insulating substrate for exposing the lands to the other side surface. Solder is provided in the through-holes. The solder connects the lands to the head terminals on an inkjet head, which is located facing the other side surface of the insulating substrate. The insulating substrate separates the solder from areas between the conducting wires and from areas between the lands, thereby preventing short circuits from occurring when manufacturing the connecting structure with a low tolerance grade.

Book
30 Nov 2003
TL;DR: In this article, the authors present a characterization of thin-film capacitors and show that they can be used in 3D ICs for large-area power distribution, including 2D and 3D packaging.
Abstract: Preface. Acknowledgements. 1: Introduction. 1.1. Capacitor Fundamentals. 1.2. Application Domains. 1.3. Physical Structures/Embodiments. 1.4. Capacitor Integration Drivers. 1.5. Thin-Film Capacitor Technology. 1.6. Summary. 1.7. References. 2: Design Fundamentals. 2.1. Breakdown Voltage and Capacitance Density Design Limits. 2.2. Tolerance in Capacitance Density. 2.3. DC Leakage. 2.4. Capacitor Losses. 2.5. Series Inductance and Resistance. 2.6. References. 3: Performance Detractors. 3.1. Interfacial Micro-roughness. 3.2. Deviation from Optimal Stoichiometry. 3.3. Film Microstructure. 3.4. References. 4: Electrical Characterization. 4.1. Thin Film Decoupling Capacitors. 4.2. Characterization Methodologies. 4.3. Test Vehicle: Design and Fabrication. 4.4. Dielectric Constant and Loss. 4.5. Total Series Inductance. 4.6. Leakage Current Density. 4.7. Capacitance Density and Breakdown Field. 4.8. Summary and Conclusion. 4.9. References. 5: Integration Issues And Challenges. 5.1. Metal Diffusion into Dielectrics. 5.2. Interlayer Stresses and Adhesion. 5.3. Low Thermal Budget. 5.4. References. 6: Applications. 6.1. 2D Interconnections in ICs. 6.2. Integration into 2D Packaging. 6.3. Flex Circuits. 6.4. Large Area Power Distribution. 6.5. Integration into 3D Structures. 6.6. Electromagnetic Considerations. 6.7. Power Electronics. 6.8. References. Index.

Patent
Keyvan Sayyah1
05 May 2003
TL;DR: In this paper, a method for transferring individual devices or circuit elements, fabricated on a semiconducting substrate, to a new substrate and placing said devices and elements in predetermined locations on the new substrate is described.
Abstract: A method for transferring of individual devices or circuit elements, fabricated on a semiconducting substrate, to a new substrate and placing said devices and elements in predetermined locations on the new substrate. The method comprises shaping the devices and circuits as truncated cones, lifting them off the original semiconducting substrates and depositing them en masse onto the new substrate, followed by their placing into receptors on the new substrate. The new substrate has preliminarily made receptors in a form of a truncated cone and the devices and circuits fill these receptors. Both the receptors and the devices and circuits have metallization contacts enabling to establish electrical contact between them. A method for real-time monitoring and verification of correctness of placement of the devices and circuits into the receptors by applying voltage pulse waveforms and measuring the resulting current pulse.

Patent
22 Jan 2003
TL;DR: In this paper, the upper polarizer of a flat display device is located on the upper transparent electrode of the touch panel that is combined with the flat display devices, which can share a glass or plastic substrate and a flexible printed circuit board substrate on the second electrode layer.
Abstract: The upper polarizer of a flat display device is located on the upper transparent electrode of the touch panel that is combined with the flat display device. Therefore, the flat display device and the touch panel can share a glass or plastic substrate and a flexible printed circuit board substrate on the second electrode layer.

Patent
Yu Zhou1, David Yu1
13 Aug 2003
TL;DR: In this paper, a probe contact system for establishing electrical connection with contact targets is presented, consisting of a main frame, a flexible printed circuit board (PCB), a contactor carrier and a plurality of contactors.
Abstract: A probe contact system for establishing electrical connection with contact targets. The probe contact system is formed of a main frame, a flexible printed circuit board (PCB), a contactor carrier and a plurality of contactors. The flexible PCB has contact pads at a center area thereof and signal lines connected to the contact pads and extended to an end of the flexible PCB. The end of the flexible PCB with the signal lines is connected to a test head of a semiconductor test system. In one aspect, the contactor has a top spring to resiliently contact with the contact pads on the flexible PCB. In another aspect, the probe contact system includes a conductive elastomer sheet between the contactor and the flexible PCB thereby obviating the top spring of the contactor.

Journal ArticleDOI
TL;DR: In this paper, the authors show that ZnO is a promising semiconductor candidate for flexible electronics, because thin film transistors can be fabricated at room temperature with higher mobility (> 1 cm2/V-s) and high on/off ratio (> 104).
Abstract: In flexible electronics, plastic substrates can limit processing temperatures to less than 100° C. Consequently, most semiconductors, including amorphous silicon, may be incompatible with temperature-sensitive plastic substrates. While organic semiconductors may seem well suited to this particular application niche, their stability is questionable and their mobility is often low (∼0.1 cm2/V-s). In this paper we show that ZnO is a promising semiconductor candidate for flexible electronics, because thin film transistors can be fabricated at room temperature with higher mobility (> 1 cm2/V-s) and high on/off ratio (> 104).

Journal ArticleDOI
TL;DR: In this paper, new developments in polyester film substrates for OLED displays have been described, which are well-known substrate for a wide range of electronic applications, such as computer vision and medical applications.
Abstract: Polyester films are well-known substrates for a wide range of electronic applications. This contribution will describe new developments in polyester film substrates for OLED displays.

Patent
31 Jul 2003
TL;DR: In this paper, a method for connecting microcircuits formed in a circuit board, such as a Tape Carrier Package (TCP), a Flexible Printed Circuit (FPC), a Liquid Crystal Display (LCD) or a printed circuit board using an anisotropic conductive adhesive including conductive particles, and the connection structure manufactured by the above method is presented.
Abstract: Disclosed is a method for connecting microcircuits formed in a circuit board, such as a Tape Carrier Package (TCP), a Flexible Printed Circuit (FPC), a Liquid Crystal Display (LCD) or a printed circuit board using an anisotropic conductive adhesive including conductive particles, and the connection structure manufactured by the above method. The method comprises the steps of applying an insulating film layer to a circuit board having circuit patterns, and then boding them with an anisotropic conduction adhesive. The circuits that should not be connected by conductive particles included in the anisotropic conductive adhesive are prevented from a short-circuit

Patent
03 Mar 2003
TL;DR: In this article, a method and system for fabricating large area, mechanically flexible electronics is described, which includes a drawing device for applying solution on a substrate during drawing of the pattern of a circuit, and a controller for adjusting the application of the solution to the substrate.
Abstract: A method and system for fabricating large area, mechanically flexible electronics is disclosed. A fabrication system includes a drawing device for applying solution on a substrate during drawing of the pattern of a circuit, and a controller for adjusting the application of the solution to the substrate. The drawing device may include a reservoir for supplying solution, such as polymer solution, to a drawing element, such as a pen, the tip of a marker. The movement and the speed of the drawing device and a table on which the substrate is placed is determined based on the image of the pattern.

Journal ArticleDOI
TL;DR: In this article, a flex circuit is modeled as a laminate of polyimide substrate, adhesive, and copper conductors and the model involves displacements of the flex circuit in the directions tangent and normal to the local equilibrium shape, and those motions couple with the arm's dynamics.
Abstract: A flex circuit connects the stationary electronic components in a hard disk drive to the rotating arm that carries the read/write heads and positions them above data tracks on the disk. Flex circuits are conventionally formed as a laminate of polyimide substrate, adhesive, and copper conductors. Deformation of a flex circuit is discussed in the context of the following stages: the initial unstressed shape, configurations in which stresses set and relax in response to elevated temperature, equilibrium, and small amplitude vibration. The model involves displacements of the flex circuit in the directions tangent and normal to the local equilibrium shape, and those motions couple with the arm's dynamics. Nonlinearity associated with finite curvature, partial elastic springback, and the arm 's geometry and inertia properties are incorporated within the vibration model to predict system-level natural frequencies, mode shapes, and coupling factors between the circuit and the arm. laboratory measurements using noncontact laser interferometry validate the model with respect to the circuit's shape, stiffness, restoring moment, and natural frequencies. The primary degrees of freedom for optimizing flex circuit design are the thicknesses of the individual layers within the circuit, free length, and the locations and slopes of the circuit's attachment points to the arm and electronics block. The model's predictions and trends developed from a case study in free length are discussed with a view toward reducing coupling between the circuit and arm in certain vibration modes.

Patent
10 Sep 2003
TL;DR: In this paper, a high-density electrical connector includes a rigid member having an array of electrical contact pads, a clamp housing attached to the rigid member, and a flexible printed circuit.
Abstract: A high-density electrical connector includes a rigid member having an array of electrical contact pads, a clamp housing attached to the rigid member, and a flexible printed circuit. The flexible printed circuit has a back surface, a front surface and a contact portion having a matching array of electrical contacts protruding outwardly of the front surface of the flexible printed circuit. The contact portion is disposed between the clamp housing and the rigid member and an elastomeric contact pressure pad is disposed between the clamp housing and the flexible printed circuit pressing each of the protruding electrical contacts into one of the electrical contact pads. The elastomeric pad is shaped and resiliently deformed by the clamp housing to provide a substantially uniform contact pressure to the array of electrical contacts.

Patent
17 Apr 2003
TL;DR: In this article, the X-ray relative intensity ratio between crystal lattice plane indices (200)/(111) in the above-mentioned crystalline structure is 0.1 or less.
Abstract: The present invention relates to a flexible printed circuit board which has extremely high adhesion performance and on which very fine circuit patterns can be formed by etching, and to a method for producing the same. In the present invention, in the flexible printed circuit board wherein a copper thin film made of copper or an alloy containing primarily copper is directly formed on at least one side of a plastic film substrate, and copper is formed further on the copper thin film by the electrolytic plating method, the above-mentioned copper thin film has a two-layer structure in which a layer including at least a crystalline structure is formed on the surface side thereof, and the X-ray relative intensity ratio between crystal lattice plane indices (200)/(111) in the above-mentioned crystalline structure is 0.1 or less.

Patent
25 Apr 2003
TL;DR: In this article, the authors proposed a method of producing a flexible printed circuit board where, even in the case electroless nickel plating is applied to both the faces of a polyimide resin film, the content of moisture remaining in the polyimides resin film is reduced, and also, the thickness of the electroless Nickel plated layer can be increased.
Abstract: PROBLEM TO BE SOLVED: To provide a method of producing a flexible printed circuit board where, even in the case electroless nickel plating is applied to both the faces of a polyimide resin film, the content of moisture remaining in the polyimide resin film is reduced, and also, the thickness of the electroless nickel plated layer can be increased. SOLUTION: First, a thin first nickel plated layer 2a is formed on both the faces of a polyimide resin film 1 by electroless nickel plating, and is thereafter dried. Next, a second nickel plated layer 2b is formed on the surface of the thin first nickel plated layer 2a by electroless nickel plating or nickel electroplating. Thereafter, a copper plated layer 3 for forming a circuit is formed on the surface of the second nickel plated layer 2b. COPYRIGHT: (C)2005,JPO&NCIPI

Patent
13 Jan 2003
TL;DR: In this paper, a flexible printed circuit board is electrically connected with a rigid printed circuit through solder, and the solder resist is formed between neighboring two lands on the rigid printed circuits and is terminated with an end portion that is interposed between the rigid circuit board and the flexible circuit board.
Abstract: Lands formed on a flexible printed circuit board are electrically connected with lands formed on a rigid printed circuit board through solder. At this point, solder resist is formed between neighboring two lands on the rigid printed circuit board, and is terminated with an end portion that is interposed between the rigid printed circuit board and the flexible printed circuit board. Accordingly, even when surplus solder is extruded onto the rigid printed circuit board, the solder resist can prevent solder bridges from being formed between the lands.

Patent
30 Apr 2003
TL;DR: In this article, a flexible electronic/optical interconnection film assembly which includes a flexible waveguide film laminated to a flexible electrical film, such as a flexible PCB, is presented.
Abstract: A flexible electronic/optical interconnection film assembly which includes a flexible waveguide film laminated to a flexible electrical film, such as a flexible PCB. The flexible waveguide film has embedded internal waveguide capable of total internal reflection such that optical transmission between two IC elements can be achieved through the use of laser diode transmitters and photodetector receivers. A flexible electrical film that is laminated to the flexible waveguide film may have a plurality of metal interconnect lines formed therein for providing electrical communication. A thin metal trace layer and a plurality of conductive pads which are formed from the thin metal trace layer may be formed on top of the flexible waveguide film for providing electrical communication with active opto-electronic devices mounted on top of the flexible waveguide film.

Patent
09 May 2003
TL;DR: In this paper, an IC die and a flexible circuit structure are integrated into a lower stack element that can be stacked with either further integrated lower stack elements iterations or with pre-packaged ICs in any of a variety of package types.
Abstract: An IC die and a flexible circuit structure are integrated into a lower stack element that can be stacked with either further integrated lower stack element iterations or with pre-packaged ICs in any of a variety of package types The present invention may be employed to stack similar or dissimilar integrated circuits and may be used to create modularized systems In a preferred embodiment, a die is positioned above the surface of portions of a pair of flex circuits Connection is made between the die and the flex circuitry A protective layer such as a molded plastic, for example, is formed to protect the flex-connected die and its connection to the flex Connective elements are placed along the flex circuitry to create an array of module contacts along the second side of the flex circuitry The flex circuitry is positioned above the body-protected die to create an integrated lower stack element The integrated lower stack element may be stacked either with iterations of the integrated lower stack element or with a pre-packaged IC to create a multi-element stacked circuit module

Patent
24 Dec 2003
TL;DR: In this article, a flexible printed circuit substrate has dummy patterns which are formed, simultaneously with the terminals, on the sides of the connecting part, in a shape corresponding to the outline of both sides of connecting part which are used for positioning the terminals when a base film is subjected to a laser process.
Abstract: A novel flexible printed circuit substrate can be processed into a flexible printed circuit board having a high-accuracy connecting part which does not cause a connection failure when it is connected to a connector even if a pitch between two adjacent terminals is further reduced. The flexible printed circuit substrate has dummy patterns which are formed, simultaneously with the terminals, on the sides of the connecting part, in a shape corresponding to the outline of both sides of connecting part which are used for positioning the terminals when the connecting part is attached to the connector. The dummy patterns are used as masks when a base film is subjected to a laser process.

Patent
19 Sep 2003
TL;DR: A polyimide film of the present invention is a polyimides film having a dynamic viscoelasticity whose tan δ peak is located in a range of not less than 310°C. but not more than 410° C. as mentioned in this paper.
Abstract: A polyimide film of the present invention is a polyimide film having a dynamic viscoelasticity whose tan δ peak is located in a range of not less than 310° C. but not more than 410° C., and whose tan δ value at 300° C. is not more than 0.05, or a polyimide film prepared by copolymerizing (a) an acid dianhydride component including a biphenyltetracarboxylic dianhydride and a pyromellitic dianhydride, and (b) a diamine component, and the polyimide film having such an etching speed that one side thereof is etched with a 1N potassium hydroxide solution at an etching speed of 0.1 μm/minute (one side) or higher. The polyimide film of the present invention possesses film properties that are necessary for use in an electronic raw material for flexible printed circuit boards and the like, and is suitable as an electronic raw material.