WO2008016479A1 - Flexible substrate with electronic devices formed thereon - Google Patents

Flexible substrate with electronic devices formed thereon Download PDF

Info

Publication number
WO2008016479A1
WO2008016479A1 PCT/US2007/016085 US2007016085W WO2008016479A1 WO 2008016479 A1 WO2008016479 A1 WO 2008016479A1 US 2007016085 W US2007016085 W US 2007016085W WO 2008016479 A1 WO2008016479 A1 WO 2008016479A1
Authority
WO
WIPO (PCT)
Prior art keywords
substrate
electronic device
particulate material
plastic material
plastic
Prior art date
Application number
PCT/US2007/016085
Other languages
French (fr)
Inventor
Timothy John Tredwell
Roger Stanley Kerr
Original Assignee
Eastman Kodak Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eastman Kodak Company filed Critical Eastman Kodak Company
Priority to EP07796875A priority Critical patent/EP2047513A1/en
Priority to JP2009522771A priority patent/JP2009545878A/en
Publication of WO2008016479A1 publication Critical patent/WO2008016479A1/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
    • H01L29/76—Unipolar devices, e.g. field effect transistors
    • H01L29/772—Field effect transistors
    • H01L29/78—Field effect transistors with field effect produced by an insulated gate
    • H01L29/786—Thin film transistors, i.e. transistors with a channel being at least partly a thin film
    • H01L29/78603—Thin film transistors, i.e. transistors with a channel being at least partly a thin film characterised by the insulating substrate or support
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers
    • H01L27/12—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being other than a semiconductor body, e.g. an insulating body
    • H01L27/1214—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being other than a semiconductor body, e.g. an insulating body comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
    • H01L27/1218—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being other than a semiconductor body, e.g. an insulating body comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs with a particular composition or structure of the substrate
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers
    • H01L27/12—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being other than a semiconductor body, e.g. an insulating body
    • H01L27/1214—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being other than a semiconductor body, e.g. an insulating body comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
    • H01L27/1259—Multistep manufacturing methods
    • H01L27/1262—Multistep manufacturing methods with a particular formation, treatment or coating of the substrate
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K77/00—Constructional details of devices covered by this subclass and not covered by groups H10K10/80, H10K30/80, H10K50/80 or H10K59/80
    • H10K77/10—Substrates, e.g. flexible substrates
    • H10K77/111—Flexible substrates
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/549—Organic PV cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • This invention generally relates to electronic devices and more particularly relates to an electronic device fabricated on a flexible substrate.
  • TFT devices are widely used in switching or driver circuitry for electro-optical arrays and display panels.
  • TFT devices are conventionally fabricated on rigid substrates, typically glass or silicon, using a well-known sequence of deposition, patterning and etching steps.
  • amorphous silicon TFT devices require deposition, patterning, and etching of metals, such as aluminum, chromium or molybdenum, of amorphous silicon semiconductors, and of insulators, such as SiO2 or Si3N4 onto a substrate.
  • the semiconductor thin film is formed in layers having typical thicknesses of from several nm to several hundred nm, with intermediary layers having thicknesses on the order of a few microns, and may be formed over an insulating surface that lies atop the rigid substrate.
  • TFT devices can be formed on some types of metal foil and plastic substrates, allowing some measure of flexibility in their fabrication.
  • problems such as chemical incompatibility between the substrate and TFT materials, thermal expansion mismatch between substrate and device layers, planarity and surface morphology, and capacitive coupling or possible shorting make metal foil substrates less desirable in many applications.
  • U.S . Patent No. 6,492,026 discloses the use of flexible plastic substrates having relatively high glass transition temperatures Tg, typically above 120 degrees C.
  • Tg glass transition temperatures
  • these substrates to withstand conventional TFT fabrication temperatures much above this range is questionable.
  • considerable effort is expended in protecting the substrate and the device(s) formed from scratch damage and moisture permeation, such as using multiple barrier layers.
  • U.S. Patent No. 6,762,124 discloses a process using an excimer laser to ablate a material through a mask to form a patterned conductor or semiconductor material for TFT formation onto a substrate.
  • the substrate that is used is a composite, "glass replacement" material that may have a flexible or rigid plastic material supplemented with one or more barrier and protective layers.
  • 2005/0163968 (Hanket) describes a micro-filled polyimide film having improved CTE and other durability enhancements. However, even where CTE can be more closely matched using microfiller additives, other problems with lamination remain. Other plastics of interest, such as Teflon®, may have some properties that are more favorable for use as flexible substrates, but present other sets of obstacles that preclude their use with conventional fabrication approaches.
  • It is an object of the present invention to provide a method of manufacturing an electronic device comprising: a) providing a substrate that comprises at least one plastic material; b) embedding a particulate material in at least one surface of the substrate; and c) forming a thin film electronic device on the surface with the particulate material.
  • the present invention provides an electronic device fabricated onto a flexible substrate.
  • the flexible substrate can include polytetrafluoroethylene (PTFE) or Teflon®, which allows reflow and therefore minimizes or eliminates the need for intermediate lamination materials.
  • PTFE polytetrafluoroethylene
  • Teflon® Teflon®
  • Figure 1 is a cross sectional view showing an electronic circuit formed using the method of the present invention
  • Figure 2 is a cross-sectional view showing a magnified portion of the composite substrate of the present invention
  • Figure 3 is a cross-sectional view showing a magnified portion of the composite substrate following surface conditioning.
  • Figure 4 is a cross-sectional view showing a magnified portion of a substrate having a composite layer atop a base layer in one embodiment.
  • Figures given in this application are representative of overall spatial relationships and arrangement of layers for deposition onto a substrate and may not be drawn to scale.
  • a thin-film component 12 such as a conductor, a thin-film transistor, a diode, or other component
  • a flexible substrate 20 such as a plastic that is a composite material, consisting of one or more particulate bonding materials and one or more plastic binders as is described subsequently.
  • Composite substrate 20 is attached to a carrier 18, such as a glass sheet, during fabrication processing. Subsequent procedures may separate substrate 20 from carrier 18 following circuit 10 fabrication.
  • One or more layers 14 may be formed for providing electrical isolation and planarization or smoothness and for providing a suitable surface for forming thin-film devices.
  • layer 14 is silicon nitride, used both to seal and insulate the surface to allow thin film deposition.
  • a supplemental layer of benzocyclobutene (BCB) or spun-on glass (SOG) is used for planarization.
  • BCB benzocyclobutene
  • SOG spun-on glass
  • the present invention also relates to the co-optimization of a plastic binder, with a particulate material applied to at least one surface of a substrate, and carrier materials and processes for bonding device layers to a flexible substrate and minimizing stress within the substrate.
  • plastic refers to a material having a high polymer content, usually made from polymeric synthetic resins, which may be combined with other ingredients, such as curing agents, fillers, reinforcing agents, colorants, and plasticizers.
  • a "resin” is a synthetic or naturally occurring polymer. Plastic is solid in its finished state, and at some stage during its manufacture or processing into finished articles, can be shaped by flow. Plastics are typically formed using a curing process, in which a solvent is evaporated at a suitable rate. Plastic includes thermoplastic materials and thermosetting materials.
  • flexible refers generally to sheet materials that are thinner than about 1 mm and that exhibit a modulus of elasticity E of plastic, which is typically between about 100,000 -500,000 psi.
  • substrate 20 has a characteristic formulation, consisting of a suitable plastic binder and conditioned with a particulate material impregnated near or on its surface.
  • a particulate material 16 is added to the base plastic composition of substrate 20, which acts as a binder with respect to the particulate.
  • Particulate material 16 is a solid particulate of some type, suitably selected both to enable bonding to layer 14 so that layer ⁇ 4 can provide insulation, passivization, or smoothing, and to modify the CTE of the plastic material itself.
  • HS-PET heat-stabilized polyethylene terephthalate
  • a number of other plastic, substrates can be used as binder, such as polyethylenenapthalate (PEN), polycarbonate (PC), polyarylate (PAR), polyetherimide (PEI), polyethersulphone (PES), polyimide (PI), Teflon® poly(perfluoro-alboxy)fluoropolymer (PFA), poly(ether ether ketone) (PEEK), poly(ether ketone) (PEK), poly(ethylene tetrafluoroethylene)fluoropolyrner (PETFE), and poly(methyl methacrylate) and various acrylate/methacrylate copolymers (PMMA).
  • PEN polyethylenenapthalate
  • PC polycarbonate
  • PAR polyarylate
  • PEI polyetherimide
  • PES polyethersulphone
  • PI polyimide
  • PFA Teflon® poly(perfluoro-alboxy)fluoropolymer
  • PEEK poly(ether ketone)
  • PEK poly(
  • Suitable plastics for use as binder may include various cyclic polyolefins, ARTON fabricated by JSR Corporation, Zeonor made by Zeon Chemicals L.P., and Topas made by Celanese AG.
  • Other lower-temperature plastic substrates can also be used, including: ethylene-chlorotrifluoro ethylene (E-CTFE), marketed as HALAR from Ausimont U.S.A., Inc., ethylene-tetra- fiuoroethylene (E-TFE) sold under the trademark TEFZEL by Dupont Corporation, poly-tetrafluoro-ethylene (PTFE), fiber glass enhanced plastic (FEP), and high density polyethylene (HDPE).
  • E-CTFE ethylene-chlorotrifluoro ethylene
  • PTFE poly-tetra- fiuoroethylene
  • FEP fiber glass enhanced plastic
  • HDPE high density polyethylene
  • certain of these plastic substrates can withstand higher processing temperatures of up to at least about 200 degrees C, with some capable of withstanding temperatures of 300 degrees C or higher without damage.
  • Plastic binder materials of special interest include polyimide, as noted earlier, and polytetrafluoroethylene (PTFE) or poly(perfluoro- alboxy)fluoropolymer (PFA), known commercially as Teflon®, sold by DuPont, Inc.
  • PTFE polytetrafluoroethylene
  • PFA poly(perfluoro- alboxy)fluoropolymer
  • Teflon® sold by DuPont, Inc.
  • neither polyimide nor PTFE, as conventionally formed are inherently well-suited as substrates for TFT deposition, although a number of different surface treatments have shown limited success.
  • these materials when these materials are treated according to the present invention, they can provide flexible substrates having highly favorable characteristics for supporting TFT circuitry.
  • compositions that include one or more of these plastic materials may be a preferred solution.
  • Suitable particulate materials 16 include glass including spun-on glass, carbon, fibers, metal fibers, and plastics. Particulate materials 16 could also be woven materials or fibers, such as woven fiberglass, for example. Particulate materials 16 may have a range of structural properties and shapes. Particulate materials 16 may be particles of roughly spherical shape, platelets of dimension smaller than, or exceeding, the thickness of the substrate. Particulate materials 16 could be elongated in shape, including wires, rods, or fibers for example. Ceramic fillers or other dielectric materials could be used as particulate materials 16.
  • the angular orientation of particulate material 16 within the plastic binder material can also be varied.
  • elongated particulate materials 16 could be dimensionally aligned, such as in a single direction or in layers of alternating directions, or aligned along two or more axes in a plane.
  • Particulate materials 16 can be oriented in a specific direction or pattern with respect to the surface of substrate 20, which may affect anisotropic optical, electronic, thermal, magnetic, chemical or physical properties.
  • fibers of particulate material 16 within the binder could be vertically oriented in order to guide light or heat in a vertical direction. Alternately, laterally oriented optical fibers could be used to guide light through composite substrate 20 in other directions.
  • Inorganic materials can be introduced as particulate materials 16 in order to modify a number of properties, such as the following: ⁇ Selected optical properties, such as color or light scattering;
  • Chemical properties such as resistance to process chemistries, or physical properties, such as CTE, tensile strength, compressive strength, modulus, or flexibility; or
  • Radiation properties such as radiation shielding or energy- selective X-ray transmission or absorption.
  • CTE coefficient of thermal expansion
  • inorganic particulate materials such as glass or ceramic as particulate material 16 also has a number of additional advantages, including:
  • the particulate material may reduce the dielectric constant of the substrate, thereby advantageously reducing capacitance.
  • Transparent particulate materials 16 would be advantaged in many applications. Where light behavior is important, particulate materials 16 may be selected based on index of refraction m relative to the index of refraction n ⁇ of the plastic binder material. Where their respective indices of refraction ni and «? are matched, or very nearly matched, optical scattering can be minimized. The closer the indices of refraction « / and ri 2 are matched, the less scattering would result. Alternately, optical scattering may be desirable, in which case, increased difference between indices of refraction n/ and «2, such as by more than about 0.1 for example, causes correspondingly increased scattering. Opaque or reflective materials could be used.
  • the material used for composite substrate 20 is a PTFE woven fiberglass laminate, such as a material from the DiClad 522, 527 Series available from Arlon, Inc. Collinso Cucamonga, CA. Dimensionally stable under temperature stress, PTFE woven fiberglass laminates have been used, for example, for printed circuit boards (PCBs) and, when used for this purpose, are supplied with a copper layer, typically an electrodeposited copper layer. For flexible substrate 20 of the present invention, no copper plating is used. For use as a flexible substrate 20, an ideal thickness for PTFE woven fiberglass laminate is in the range of about 25 microns to about 3000 microns.
  • TFT fabrication processing is as follows:
  • the flexible substrate is initially laminated onto a glass carrier 18. This is done by positioning substrate 20 on carrier 18 and treating this combination by applying heat and pressure to achieve the flow temperature (Tg) of the PTFE material, approximately 300 degrees C.
  • Tg flow temperature
  • the PTFE material softens, reflows, and bonds to the surface of carrier 18.
  • layer 14 is a planarization layer.
  • Layer 14 may alternately be another preparatory material or may include materials used in forming the thin-film electronic device itself. This treatment is effected by embedding particulate material 16 into the substrate surface. As shown in Figure 2, it is advantageous to add particulate material 16 nearest the surface of substrate 20.
  • Particulate material 16 can be applied to the surface by numerous methods, including rolling, or dusting, for example.
  • Particulate material 16 can alternately be applied by inkjet deposition, printing, transfer from an intermediate material, application using doctor-blade skiving techniques, such as in a solvent, sprinkling, or other methods.
  • the plastic material can be heated to facilitate embedding of particulate material 16. Alternately, particulate material 16 can be added to the binder plastic material during curing processes.
  • the desired surface roughness for TFT deposition can be on the order of less than 0.2 to 0.3 microns peak-to-peak in some applications.
  • spun-on glass SOG
  • a sol of colloidal silica particles in a solvent is applied to the substrate
  • the method of the present invention also binds TFT components to the surface of substrate 20 in an improved manner.
  • Particulate material 16 that lies near the surface or even extends slightly outward from the surface of composite substrate 20 provides binding surface area for layer 14, which may be an insulating silicon nitride or silicon oxide layer. Without particulate material 16, these silicon compounds would be unable to bond to the surface, seriously hampering the capability to fabricate a workable TFT device or other type of electronic device thereon.
  • an electrical isolation layer is deposited on top of the planarization layer.
  • a suitable isolation layer material can be SiO2, SiNx, SiON, or some combination of these materials. This is typically in the range from about 0.5 to 1.5
  • TFT elements Following preparation of the flexible substrate 20 surface, the lay-down of TFT elements can begin. This typically requires depositing a layer of thin-film semiconductor material onto the substrate, then forming a pattern by selective removal of portions of the semiconductor material. This procedure uses processes that are well known in the art of component fabrication for lay-down of gate, source, and drain components and other supporting layers.
  • Example 1 Delamination from carrier 18. This may require application of heat at temperatures near the flow temperature of the substrate plastic material. This allows separation of substrate 20 from carrier 18. Once separated, substrate 20 can be laminated to some other surface or allowed to cool.
  • the method of Example 1 could be modified for specific substrate and component types. Other spin-coated dielectric treatments could alternately be used, for example.
  • Example 2
  • particulate material 16 to the melted plastic as a filler.
  • particulate material 16 works best if deposited on or near the surface of substrate 20.
  • CTE For improved CTE, however, a more general distribution of particles mixed throughout the plastic material is preferred. In most cases, it is preferred to have a thicker concentration of particulate material 16, or exposed portions of particulate material 16 near the surface of substrate 20. Thus, this step would require some mixing of particulate material 16 with the melted plastic binder.
  • Tg flow temperature
  • the desired surface roughness for TFT deposition can be on the order of less than 0.2 to 0.3 microns peak-to-peak in some applications.
  • spun-on glass SOG
  • a sol of colloidal silica particles in a solvent is applied to the substrate 20 surface.
  • Temperature at 300 - 400 degrees C is applied to cure the sol material, removing solvent and leaving a gel residue that, when itself heated, converts to an SiO 2 film having dielectric constant ⁇ between about 3 and 5 and providing the necessary insulation and planarization needed prior to TFT deposition.
  • Alternative planarization materials are described subsequently.
  • an electrical isolation layer is deposited on top of the planarization layer.
  • a suitable isolation layer material can be SiO2, SiNx, SiON, or some combination of these materials. This is typically in the range from about 0.5 to 1.5 ⁇ m.
  • TFT elements Following preparation of the flexible substrate 20 surface, the lay-down of TFT elements can begin. This procedure uses processes that are well known in the art of component fabrication for lay-down of gate, source, and drain components and other supporting layers. As part of TFT fabrication, semiconductor material is deposited, then a pattern is formed by selectively removing portions of the semiconductor material. 7. Delamination from carrier 18. This may require application of heat at temperatures near the flow temperature of the substrate plastic material. This allows separation of substrate 20 from carrier 18. Once separated, substrate 20 can be laminated to some other surface or allowed to cool. Alternate delamination methods could also be employed.
  • substrate 20 is formed from polyimide or a polyimide composition and binder, using the following steps:
  • the desired surface roughness for TFT deposition can be on the order of less than 0.2 to 0.3 microns peak-to-peak in some applications.
  • spun-on glass SOG
  • a sol of colloidal silica particles in a solvent is applied to the substrate 20 surface.
  • Temperature at 300 - 400 degrees C is applied to cure the sol material, removing solvent and leaving a gel residue that, when itself heated, converts to an SiC> 2 film having dielectric constant ⁇ between about 3 and 5 and providing the necessary insulation and planarization needed prior to TFT deposition.
  • Alternative planarization materials are described subsequently.
  • an electrical isolation layer is deposited on top of the planarization layer.
  • a suitable isolation layer material can be SiO2, SiNx, SiON, or some combination of these materials. This is typically in the range from about 0.5 to 1.5 ⁇ m.
  • Forming TFT elements Following preparation of the flexible substrate 20 surface, the lay-down of TFT elements can begin. This procedure uses processes that are well known in the art of component fabrication for lay-down of gate, source, and drain components and other supporting layers. As part of TFT fabrication, semiconductor material is deposited, then a pattern is formed by selectively removing portions of the semiconductor material.
  • Conditioning of the surface of substrate 20 to improve bonding of layer 14 and other materials for thin-film device fabrication can be performed in a number of ways.
  • the method of the present invention works best when surfaces of the particulate material 16 are exposed on the surface of substrate 20, providing bonding surfaces thereby.
  • the surface of substrate 20 generally has a high proportion of resinous content, even when a filler of particulate material 16 has been used.
  • exposure of particulate material 16 for improved bonding may require some method for removing some percentage of plastic material along the surface itself.
  • FIG. 3 The magnified portion of Figure 3 shows how a surface 22 can be featured when exposing particulate material 16.
  • Methods for conditioning the surface in this way include the following:
  • the reflow advantages of PTFE are utilized to advantage for surface conditioning.
  • Particulate material 16 can be dusted or sprinkled onto the heated surface of PTFE or a PTFE composition with another suitable material, at just above its glass transition temperature Tg. Allowing the PTFE material to cool then yields a surface conditioned for deposition of planarization or other layers. Some amount of treatment, using the conditioning methods just described, may be used to improve the surface of substrate 20 following the deposition of particulate material 16.
  • a first plastic material is provided as a base substrate 24. Then, a composition 26 is coated onto the surface of this base substrate, where the composition includes one plastic binder material that is mixed with at least one particulate material 16.
  • planarization layer 14 as shown in Figure 4, an isolation layer, or an electronically active semiconductor layer used to form some portion of a thin-film electronic device.
  • Planarization Materials may be, for example, planarization layer 14 as shown in Figure 4, an isolation layer, or an electronically active semiconductor layer used to form some portion of a thin-film electronic device.
  • planarization materials may be used in different embodiments:
  • BCB Benzocyclobutene
  • TEOS Tetraethoxysilane
  • the method of the present invention promotes improved adhesion of the TFT layers, since glass, ceramic, or other suitable particulate provides better adhesion than does the plastic binder alone.
  • the use of particulate material 16 increases the temperature limits before loss of dimensional stability, allowing device fabrication at higher temperatures.
  • the method of the present invention is advantaged since it allows the formation of TFT components directly on a flexible substrate, without the need for intermediate steps such as lamination.
  • This method can be particularly well-suited to web or roll-to-roll fabrication, in which a substrate sheet would be unwound from a first roll, undergo surface conditioning by embedding particulate material 16 as described earlier, and be further processed or rewound on a second roll for future use.
  • a broad range of particulate substances of various types could be employed as particulate material 16 or a mixture of particulate materials used, taking advantage of favorable properties of multiple materials. Additional types of surface conditioning could be used at various points in the electronic device fabrication process, using tools such as plasma etching, as noted earlier.
  • One or both sides of a sheet of substrate material can be treated using the method of the present invention.
  • Various methods, including embossing, can be used for preparing the surface of substrate 20 prior to applying planarization layer 14 and TFT device formation.
  • Components formed on substrate 20 or on planarization layer 14 can include optical components, including refractive components such as one or more lenses or lenslets. Lenslets could be spatially aligned with TFT components, to provide input or output pixel elements.
  • the electronic device formed on substrate 20 can be used to provide signals to or from any of a number of different types of components and would have particular applications for image display pixels or image sensing pixels.
  • the electronic device formed on the substrate 20 surface can be coupled with a corresponding liquid crystal pixel, light-emitting diode pixel, or organic light-emitting diode pixel for display, for example.
  • the electronic device formed on the substrate 20 surface can be coupled with a stimulable phosphor pixel or with another type of sensor pixel, including a biological detector.
  • the present invention also relates to multi-layer substrates in which the bottom layer is optimized for properties related to the carrier (such as adhesive properties to the carrier), the top layer is optimized for properties related to the electronic device (such as adhesion to the device layers) and intervening layers are optimized to achieve selected properties, such as optical, electronic, thermal, magnetic or chemical properties.
  • the carrier such as adhesive properties to the carrier
  • the top layer is optimized for properties related to the electronic device (such as adhesion to the device layers)
  • intervening layers are optimized to achieve selected properties, such as optical, electronic, thermal, magnetic or chemical properties.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Thin Film Transistor (AREA)
  • Laminated Bodies (AREA)
  • Liquid Crystal (AREA)
  • Electroluminescent Light Sources (AREA)

Abstract

A method of manufacturing an electronic device (10) provides a substrate (20) that has a plastic material. A particulate material (16) is embedded in at least one surface of the substrate. A layer of thin-film semiconductor material is deposited onto the substrate (20).

Description

FLEXIBLE SUBSTRATE WITH ELECTRONIC DEVICES FORMED
THEREON FIELD OF THE INVENTION
This invention generally relates to electronic devices and more particularly relates to an electronic device fabricated on a flexible substrate.
BACKGROUND OF THE INVENTION
Thin-film transistor (TFT) devices are widely used in switching or driver circuitry for electro-optical arrays and display panels. TFT devices are conventionally fabricated on rigid substrates, typically glass or silicon, using a well-known sequence of deposition, patterning and etching steps. For example, amorphous silicon TFT devices require deposition, patterning, and etching of metals, such as aluminum, chromium or molybdenum, of amorphous silicon semiconductors, and of insulators, such as SiO2 or Si3N4 onto a substrate. The semiconductor thin film is formed in layers having typical thicknesses of from several nm to several hundred nm, with intermediary layers having thicknesses on the order of a few microns, and may be formed over an insulating surface that lies atop the rigid substrate.
The requirement for a rigid substrate is based largely on the demands of the fabrication process itself. Thermal characteristics are of particular importance, since TFT devices are fabricated at relatively high temperatures. Thus, the range of substrate materials that have been used successfully is somewhat limited, generally to glass, quartz, or other rigid, silicon-based materials.
TFT devices can be formed on some types of metal foil and plastic substrates, allowing some measure of flexibility in their fabrication. However, problems such as chemical incompatibility between the substrate and TFT materials, thermal expansion mismatch between substrate and device layers, planarity and surface morphology, and capacitive coupling or possible shorting make metal foil substrates less desirable in many applications. Clearly, there would be advantages in improving and expanding the range of suitable substrate materials for electronic devices such as TFTs to include more types of plastics and plastic materials with improved characteristics. This would allow fabrication on a flexible substrate and help to reduce the overall weight of display and other electro-optic components. It could be feasible to fabricate thinner devices. In addition, this capability could enable fabrication of larger displays and devices, since crystalline silicon and many types of glass that are conventionally employed as substrates become increasingly difficult to form and manage in large sheets.
While there are clear advantages to plastic and other flexible substrates, there are significant disadvantages that have discouraged use of such substrates, including the following: • Incompatibility with the high temperature range required for TFT fabrication.
• Poor dimensional stability at high temperatures.
• Mismatch of coefficient of thermal expansion (CTE) of plastic and thin-film semiconductor materials. • High moisture absorption characteristics of plastics.
• Poor transparency for many types of plastic.
• The requirement to attach and detach the plastic substrate material from a carrier.
Chief among these disadvantages are temperature-related requirements. The fabrication process for the TFT may require temperatures in the range of 200-300 degrees C or higher, including temperatures at levels where many types of plastic substrates would be unusable. Thus, it is widely held, as is stated in U.S. Patent No. 7,045,442 (Maruyama et al.), that a TFT cannot be directly formed on a plastic substrate. In order to provide the benefits of TFT devices mounted on a plastic substrate, the Maruyama et al. '442 disclosure describes a method that forms the TFT on a release layer that is initially attached to a carrier substrate. Once the TFT circuitry is fabricated, the release layer is then separated from its carrier substrate and can be laminated onto a lighter and more flexible plastic material. As one alternative solution, U.S . Patent No. 6,492,026 (Graff et al.) discloses the use of flexible plastic substrates having relatively high glass transition temperatures Tg, typically above 120 degrees C. However, the capability for these substrates to withstand conventional TFT fabrication temperatures much above this range is questionable. Moreover, in order to use these plastics, considerable effort is expended in protecting the substrate and the device(s) formed from scratch damage and moisture permeation, such as using multiple barrier layers.
Another alternative solution is described in U.S. Patent No. 6,680,485 (Carey et al.) In the method described in the Carey et al. '485 disclosure, energy from a pulsed laser source is used to form amorphous and polycrystalline channel silicon TFTs onto low-temperature plastic substrates. The conventional, low-temperature plastic substrates for which this method is described include polyethylene terephthalate (PET), polyethersulfone (PES), and high density polyethylene (HDPE), for example.
Similarly, U.S. Patent No. 6,762,124 (Kian et al.) discloses a process using an excimer laser to ablate a material through a mask to form a patterned conductor or semiconductor material for TFT formation onto a substrate. In the Kian et al. '124 disclosure, the substrate that is used is a composite, "glass replacement" material that may have a flexible or rigid plastic material supplemented with one or more barrier and protective layers.
Although these and similar solutions have been proposed for forming TFT components on flexible substrates, drawbacks remain. Lamination of a release layer that is populated with TFT devices, as described in Maruyama et al. '442 requires additional fabrication steps and materials and presents inherent alignment difficulties. The use of high-performance plastics, such as that of the Graff et al. '026 disclosure, still leaves thermal expansion (CTE) difficulties and requires additional layers and processes in order to protect the plastic. The excimer layer solutions proposed in the Carey et al. '485 and Kian et al. '124 disclosures do not provide the full breadth of capabilities of more conventional TFT fabrication techniques and thus have limited utility. None of these disclosures provide a flexible substrate that truly serves to replace glass or other silicon-based substrate, since the TFT must be formed either on a release layer or on some intermediate layer that must be formed on top of the flexible substrate. One particular flexible material of interest for use as a substrate, with properties including dimensional stability and heat and chemical resistance, is the class of polyimides. However, even with its advantages, polyimide material presents significant obstacles to direct deposition of TFTs. For example, additional release layers and transfer layers must be employed, since reflow behavior is not characteristic of polyimides. The CTE of polyimide differs from that of thin-film semiconductor materials, leading to fracturing and electrical discontinuity following high-temperature fabrication. In one attempt to improve polyimide material characteristics, U.S. Patent Application Publication No. 2005/0163968 (Hanket) describes a micro-filled polyimide film having improved CTE and other durability enhancements. However, even where CTE can be more closely matched using microfiller additives, other problems with lamination remain. Other plastics of interest, such as Teflon®, may have some properties that are more favorable for use as flexible substrates, but present other sets of obstacles that preclude their use with conventional fabrication approaches.
It can, therefore, be appreciated that there is an unmet need for a fabrication method for forming TFTs directly onto a flexible substrate with a minimum number of additional steps and procedures for preparation or conditioning of the substrate itself. SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method of manufacturing an electronic device comprising: a) providing a substrate that comprises at least one plastic material; b) embedding a particulate material in at least one surface of the substrate; and c) forming a thin film electronic device on the surface with the particulate material.
It is a feature of the present invention that it provides an electronic device fabricated onto a flexible substrate. The flexible substrate can include polytetrafluoroethylene (PTFE) or Teflon®, which allows reflow and therefore minimizes or eliminates the need for intermediate lamination materials. The present invention also makes it possible to fabricate electronic devices onto thinner substrates.
It is another advantage of the present invention that it provides a plastic substrate that can offer improved lamination, including self-lamination to a carrier.
These and other objects, features, and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described an illustrative embodiment of the invention. BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter of the present invention, it is believed that the invention will be better understood from the following description when taken in conjunction with the accompanying drawings, wherein: Figure 1 is a cross sectional view showing an electronic circuit formed using the method of the present invention;
Figure 2 is a cross-sectional view showing a magnified portion of the composite substrate of the present invention;
Figure 3 is a cross-sectional view showing a magnified portion of the composite substrate following surface conditioning; and
Figure 4 is a cross-sectional view showing a magnified portion of a substrate having a composite layer atop a base layer in one embodiment. DETAILED DESCRIPTION OF THE INVENTION
The present description is directed in particular to elements forming part of, or cooperating more directly with, apparatus in accordance with the invention. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art.
Figures given in this application are representative of overall spatial relationships and arrangement of layers for deposition onto a substrate and may not be drawn to scale.
Referring to Figure I5 there is shown an electronic device 10 formed according to the present invention. A thin-film component 12, such as a conductor, a thin-film transistor, a diode, or other component, is formed onto a flexible substrate 20 such as a plastic that is a composite material, consisting of one or more particulate bonding materials and one or more plastic binders as is described subsequently. Composite substrate 20 is attached to a carrier 18, such as a glass sheet, during fabrication processing. Subsequent procedures may separate substrate 20 from carrier 18 following circuit 10 fabrication. One or more layers 14 may be formed for providing electrical isolation and planarization or smoothness and for providing a suitable surface for forming thin-film devices. In one embodiment, layer 14 is silicon nitride, used both to seal and insulate the surface to allow thin film deposition. In another embodiment, a supplemental layer of benzocyclobutene (BCB) or spun-on glass (SOG) is used for planarization. When used in this way, layer 14 is conventionally referred to as a type of planarization layer.
The present invention also relates to the co-optimization of a plastic binder, with a particulate material applied to at least one surface of a substrate, and carrier materials and processes for bonding device layers to a flexible substrate and minimizing stress within the substrate.
As the term is used in the present description, "plastic" refers to a material having a high polymer content, usually made from polymeric synthetic resins, which may be combined with other ingredients, such as curing agents, fillers, reinforcing agents, colorants, and plasticizers. A "resin" is a synthetic or naturally occurring polymer. Plastic is solid in its finished state, and at some stage during its manufacture or processing into finished articles, can be shaped by flow. Plastics are typically formed using a curing process, in which a solvent is evaporated at a suitable rate. Plastic includes thermoplastic materials and thermosetting materials.
The term "flexible" refers generally to sheet materials that are thinner than about 1 mm and that exhibit a modulus of elasticity E of plastic, which is typically between about 100,000 -500,000 psi. In order to support fabrication of electronic device 10 as shown in
Figure 1, substrate 20 has a characteristic formulation, consisting of a suitable plastic binder and conditioned with a particulate material impregnated near or on its surface. Referring to Figure 2, the structural arrangement of composite substrate 20 for one embodiment is represented in a magnified view. A particulate material 16 is added to the base plastic composition of substrate 20, which acts as a binder with respect to the particulate. Particulate material 16 is a solid particulate of some type, suitably selected both to enable bonding to layer 14 so that layer \ 4 can provide insulation, passivization, or smoothing, and to modify the CTE of the plastic material itself. With the addition of particulate material 16 near the surface, it is now possible to fabricate TFT and other thin-film devices onto substrates such as PTFE that were previously not compatible with thin- film deposition. This conditioning of the surface of substrate 20 thus allows fabrication of electronic devices and their related connection traces and other components on a flexible substrate. Composite substrate 20, when fabricated in this way, is capable of withstanding high temperatures and is resilient to various types of etchants and processes required for TFT formation. Plastic Material
By adding an appropriate particulate material 16 to a plastic, as is described subsequently, the method of the present invention allows an expanded list of plastic materials to be used for flexible substrates. Exemplary binder plastic materials include, but would not be limited to, heat-stabilized polyethylene terephthalate (HS-PET). A number of other plastic, substrates can be used as binder, such as polyethylenenapthalate (PEN), polycarbonate (PC), polyarylate (PAR), polyetherimide (PEI), polyethersulphone (PES), polyimide (PI), Teflon® poly(perfluoro-alboxy)fluoropolymer (PFA), poly(ether ether ketone) (PEEK), poly(ether ketone) (PEK), poly(ethylene tetrafluoroethylene)fluoropolyrner (PETFE), and poly(methyl methacrylate) and various acrylate/methacrylate copolymers (PMMA). Suitable plastics for use as binder may include various cyclic polyolefins, ARTON fabricated by JSR Corporation, Zeonor made by Zeon Chemicals L.P., and Topas made by Celanese AG. Other lower-temperature plastic substrates can also be used, including: ethylene-chlorotrifluoro ethylene (E-CTFE), marketed as HALAR from Ausimont U.S.A., Inc., ethylene-tetra- fiuoroethylene (E-TFE) sold under the trademark TEFZEL by Dupont Corporation, poly-tetrafluoro-ethylene (PTFE), fiber glass enhanced plastic (FEP), and high density polyethylene (HDPE). Transparent plastics would be highly advantaged in some applications.
With added particulate material 16, certain of these plastic substrates can withstand higher processing temperatures of up to at least about 200 degrees C, with some capable of withstanding temperatures of 300 degrees C or higher without damage.
Plastic binder materials of special interest include polyimide, as noted earlier, and polytetrafluoroethylene (PTFE) or poly(perfluoro- alboxy)fluoropolymer (PFA), known commercially as Teflon®, sold by DuPont, Inc. As noted earlier, neither polyimide nor PTFE, as conventionally formed, are inherently well-suited as substrates for TFT deposition, although a number of different surface treatments have shown limited success. However, when these materials are treated according to the present invention, they can provide flexible substrates having highly favorable characteristics for supporting TFT circuitry. In yet other embodiments, compositions that include one or more of these plastic materials may be a preferred solution. For example, it can be advantageous to combine a polyimide with polytetrafluoroethylene (PTFE) or poly(perfluoro-alboxy)fiuoropolymer (PFA) in order to obtain the more favorable properties of both plastics. Characteristics of Particulate Material
Suitable particulate materials 16 include glass including spun-on glass, carbon, fibers, metal fibers, and plastics. Particulate materials 16 could also be woven materials or fibers, such as woven fiberglass, for example. Particulate materials 16 may have a range of structural properties and shapes. Particulate materials 16 may be particles of roughly spherical shape, platelets of dimension smaller than, or exceeding, the thickness of the substrate. Particulate materials 16 could be elongated in shape, including wires, rods, or fibers for example. Ceramic fillers or other dielectric materials could be used as particulate materials 16.
The angular orientation of particulate material 16 within the plastic binder material can also be varied. For example, elongated particulate materials 16 could be dimensionally aligned, such as in a single direction or in layers of alternating directions, or aligned along two or more axes in a plane. Particulate materials 16 can be oriented in a specific direction or pattern with respect to the surface of substrate 20, which may affect anisotropic optical, electronic, thermal, magnetic, chemical or physical properties. As just one example, fibers of particulate material 16 within the binder could be vertically oriented in order to guide light or heat in a vertical direction. Alternately, laterally oriented optical fibers could be used to guide light through composite substrate 20 in other directions.
Inorganic materials can be introduced as particulate materials 16 in order to modify a number of properties, such as the following: ♦ Selected optical properties, such as color or light scattering;
• Selected electronic properties, such as carbon filling for conductivity or electrical shielding;
• Selected thermal properties, such as metal particle filling to improve thermal conductivity; ♦ Selected magnetic properties, with magnetic materials including ferromagnetic materials utilized for magnetic attachment or for data storage;
• Chemical properties, such as resistance to process chemistries, or physical properties, such as CTE, tensile strength, compressive strength, modulus, or flexibility; or
• Radiation properties, such as radiation shielding or energy- selective X-ray transmission or absorption.
One important result of the combination of particulate material 16 with plastic binder material according to the present invention relates to improved coefficient of thermal expansion (CTE). It has been found that the CTE of the composite substrate more closely approximates the CTE of device layers for TFT devices than it approximates the CTE of the plastic binder. Thus, the CTE of the composite substrate more closely approximates the CTE of glass or silicon carriers 18 that are conventionally used for device fabrication. As a result, less stress is introduced in the device layers during device fabrication, improving device performance, dimensional stability, and reliability. This also minimizes the likelihood of delamination, in which the TFT device would be separated from is substrate.
The addition of inorganic particulate materials such as glass or ceramic as particulate material 16 also has a number of additional advantages, including:
• Adhesion of the TFT layers is improved because the particulate surface provides better adhesion than does the plastic binder alone.
• Improved temperature limits for device fabrication: the use of particulate material increases the temperature limits before loss of dimensional stability, allowing device fabrication at higher temperatures.
• In some combinations of materials, the particulate material may reduce the dielectric constant of the substrate, thereby advantageously reducing capacitance.
Transparent particulate materials 16 would be advantaged in many applications. Where light behavior is important, particulate materials 16 may be selected based on index of refraction m relative to the index of refraction n^ of the plastic binder material. Where their respective indices of refraction ni and «? are matched, or very nearly matched, optical scattering can be minimized. The closer the indices of refraction «/ and ri2 are matched, the less scattering would result. Alternately, optical scattering may be desirable, in which case, increased difference between indices of refraction n/ and «2, such as by more than about 0.1 for example, causes correspondingly increased scattering. Opaque or reflective materials could be used. Light-absorbing colorants could be added to the plastic material as well as to particulate material 16 for absorbing stray light, adding color, or providing a filter for incoming or outgoing light. Similarly, planarization layer 14 could have a colorant. Example 1 In one embodiment, the material used for composite substrate 20 is a PTFE woven fiberglass laminate, such as a material from the DiClad 522, 527 Series available from Arlon, Inc. Rancho Cucamonga, CA. Dimensionally stable under temperature stress, PTFE woven fiberglass laminates have been used, for example, for printed circuit boards (PCBs) and, when used for this purpose, are supplied with a copper layer, typically an electrodeposited copper layer. For flexible substrate 20 of the present invention, no copper plating is used. For use as a flexible substrate 20, an ideal thickness for PTFE woven fiberglass laminate is in the range of about 25 microns to about 3000 microns.
Given this substrate, TFT fabrication processing is as follows:
1. Mounting on carrier 18. The flexible substrate is initially laminated onto a glass carrier 18. This is done by positioning substrate 20 on carrier 18 and treating this combination by applying heat and pressure to achieve the flow temperature (Tg) of the PTFE material, approximately 300 degrees C. The PTFE material softens, reflows, and bonds to the surface of carrier 18.
2. Surface treatment. This next step conditions or treats the surface of substrate 20 in order to provide a suitable base to allow adhesion of layer 14. In one embodiment, layer 14 is a planarization layer. Layer 14 may alternately be another preparatory material or may include materials used in forming the thin-film electronic device itself. This treatment is effected by embedding particulate material 16 into the substrate surface. As shown in Figure 2, it is advantageous to add particulate material 16 nearest the surface of substrate 20. Particulate material 16 can be applied to the surface by numerous methods, including rolling, or dusting, for example. Particulate material 16 can alternately be applied by inkjet deposition, printing, transfer from an intermediate material, application using doctor-blade skiving techniques, such as in a solvent, sprinkling, or other methods. The plastic material can be heated to facilitate embedding of particulate material 16. Alternately, particulate material 16 can be added to the binder plastic material during curing processes.
Still other methods for surface treatment are described subsequently. 3. Planarization. The desired surface roughness for TFT deposition can be on the order of less than 0.2 to 0.3 microns peak-to-peak in some applications. In order to achieve this, spun-on glass (SOG) is deposited. To apply this substance, a sol of colloidal silica particles in a solvent is applied to the substrate
20 surface. Temperature at 300 - 400 degrees C is applied to cure the sol material, removing solvent and leaving a gel residue that, when itself heated, converts to an SiO2 film having dielectric constant ε between about 3 and 5 and providing the necessary insulation and planarization needed prior to TFT deposition. Alternative planarization materials are described subsequently.
In addition to improvements in CTE matching and response, the method of the present invention also binds TFT components to the surface of substrate 20 in an improved manner. Particulate material 16 that lies near the surface or even extends slightly outward from the surface of composite substrate 20 provides binding surface area for layer 14, which may be an insulating silicon nitride or silicon oxide layer. Without particulate material 16, these silicon compounds would be unable to bond to the surface, seriously hampering the capability to fabricate a workable TFT device or other type of electronic device thereon.
4. Forming electrical isolation layer. As a final surface preparation step for conditioning the surface of the substrate, which may be optional, an electrical isolation layer is deposited on top of the planarization layer. A suitable isolation layer material can be SiO2, SiNx, SiON, or some combination of these materials. This is typically in the range from about 0.5 to 1.5 |±m.
5. Forming TFT elements. Following preparation of the flexible substrate 20 surface, the lay-down of TFT elements can begin. This typically requires depositing a layer of thin-film semiconductor material onto the substrate, then forming a pattern by selective removal of portions of the semiconductor material. This procedure uses processes that are well known in the art of component fabrication for lay-down of gate, source, and drain components and other supporting layers.
6. Delamination from carrier 18. This may require application of heat at temperatures near the flow temperature of the substrate plastic material. This allows separation of substrate 20 from carrier 18. Once separated, substrate 20 can be laminated to some other surface or allowed to cool. The method of Example 1 could be modified for specific substrate and component types. Other spin-coated dielectric treatments could alternately be used, for example. Example 2
This next example considers additional steps that may be needed in order to formulate composite substrate 20. The basic steps are as follows: 1. Heat the plastic to its melt temperature Tg.
2. Add particulate material 16 to the melted plastic as a filler. For improved bonding, particulate material 16 works best if deposited on or near the surface of substrate 20. For improved CTE, however, a more general distribution of particles mixed throughout the plastic material is preferred. In most cases, it is preferred to have a thicker concentration of particulate material 16, or exposed portions of particulate material 16 near the surface of substrate 20. Thus, this step would require some mixing of particulate material 16 with the melted plastic binder. 3. Mounting on carrier 18. The flexible substrate is initially laminated onto a glass carrier 18. This is done by positioning substrate 20 on carrier 18 and treating this combination by applying heat and pressure to achieve the flow temperature (Tg) of the PTFE material, approximately 300 degrees C. The PTFE material softens, reflows, and bonds to the surface of carrier 18.
4. Planarization. The desired surface roughness for TFT deposition can be on the order of less than 0.2 to 0.3 microns peak-to-peak in some applications. In order to achieve this, spun-on glass (SOG) is deposited. To apply this substance, a sol of colloidal silica particles in a solvent is applied to the substrate 20 surface. Temperature at 300 - 400 degrees C is applied to cure the sol material, removing solvent and leaving a gel residue that, when itself heated, converts to an SiO2 film having dielectric constant ε between about 3 and 5 and providing the necessary insulation and planarization needed prior to TFT deposition. Alternative planarization materials are described subsequently.
5. Forming electrical isolation layer. As a final surface preparation step for conditioning the surface of the substrate, which may be optional, an electrical isolation layer is deposited on top of the planarization layer. A suitable isolation layer material can be SiO2, SiNx, SiON, or some combination of these materials. This is typically in the range from about 0.5 to 1.5 μm.
6. Forming TFT elements. Following preparation of the flexible substrate 20 surface, the lay-down of TFT elements can begin. This procedure uses processes that are well known in the art of component fabrication for lay-down of gate, source, and drain components and other supporting layers. As part of TFT fabrication, semiconductor material is deposited, then a pattern is formed by selectively removing portions of the semiconductor material. 7. Delamination from carrier 18. This may require application of heat at temperatures near the flow temperature of the substrate plastic material. This allows separation of substrate 20 from carrier 18. Once separated, substrate 20 can be laminated to some other surface or allowed to cool. Alternate delamination methods could also be employed.
Example 3 In another embodiment, substrate 20 is formed from polyimide or a polyimide composition and binder, using the following steps:
1. Coat uncured plastic binder material onto a suitable carrier. Here, partially cured polyimide is coated onto the carrier. Any suitable method of application can be used, including dip- skiving, spun-on application, or extrusion.
2. Cure the uncured plastic material until the curing process is largely completed.
3. When approximately 80% of the curing cycle is complete, add particulate material 16 onto the surface of substrate 20. Here, the particulate material 16 is sprinkled onto the surface, to provide an even coating.
4. Complete the curing process, baking off the remaining solvent. 5. Planarization. The desired surface roughness for TFT deposition can be on the order of less than 0.2 to 0.3 microns peak-to-peak in some applications. In order to achieve this, spun-on glass (SOG) is deposited. To apply this substance, a sol of colloidal silica particles in a solvent is applied to the substrate 20 surface. Temperature at 300 - 400 degrees C is applied to cure the sol material, removing solvent and leaving a gel residue that, when itself heated, converts to an SiC>2 film having dielectric constant ε between about 3 and 5 and providing the necessary insulation and planarization needed prior to TFT deposition. Alternative planarization materials are described subsequently.
6. Forming electrical isolation layer. As a final surface preparation step for conditioning the surface of the substrate, which may be optional, an electrical isolation layer is deposited on top of the planarization layer. A suitable isolation layer material can be SiO2, SiNx, SiON, or some combination of these materials. This is typically in the range from about 0.5 to 1.5 μm. 7. Forming TFT elements. Following preparation of the flexible substrate 20 surface, the lay-down of TFT elements can begin. This procedure uses processes that are well known in the art of component fabrication for lay-down of gate, source, and drain components and other supporting layers. As part of TFT fabrication, semiconductor material is deposited, then a pattern is formed by selectively removing portions of the semiconductor material.
8. Delamination from carrier 18. This may require application of heat at temperatures near the flow temperature of the substrate plastic material. This allows separation of substrate 20 from carrier 18. Once separated, substrate 20 can be laminated to some other surface or allowed to cool. Alternate delamination methods could also be employed. In an alternative embodiment, particulate material 16 can be added to uncured plastic as a filler, with the CTE advantages described in Example 2. Surface Treatment Methods
Conditioning of the surface of substrate 20 to improve bonding of layer 14 and other materials for thin-film device fabrication can be performed in a number of ways. As noted earlier, the method of the present invention works best when surfaces of the particulate material 16 are exposed on the surface of substrate 20, providing bonding surfaces thereby. Because of the nature of the plastic material used as binder in substrate 20, the surface of substrate 20 generally has a high proportion of resinous content, even when a filler of particulate material 16 has been used. Thus, exposure of particulate material 16 for improved bonding may require some method for removing some percentage of plastic material along the surface itself.
The magnified portion of Figure 3 shows how a surface 22 can be featured when exposing particulate material 16. Methods for conditioning the surface in this way include the following:
• Chemical removal, such as using etchant materials, including a number of suitable acids. • Plasma etching.
• Corona discharge treatment
• Heat application. • Use of super-critical carbon-dioxide, CO2.
• Laser ablation.
• Thermal decomposition in vacuum.
Application of these surface treatment methods for plastic binder material removal is familiar to those skilled in the surface treatment arts. Unlike the exemplary embodiment of Figure 1, in which particulate particulate material 16 is added or embedded as a filler that is heavily concentrated on and near the surface of substrate 20, these surface treatment methods can be used when substrate 20 consists of a mixture of particulate material 16 that is more or less evenly mixed throughout as filler within the plastic binder. As was noted earlier, an inherent advantage to such a material is its improved CTE.
In another embodiment, the reflow advantages of PTFE are utilized to advantage for surface conditioning. Particulate material 16 can be dusted or sprinkled onto the heated surface of PTFE or a PTFE composition with another suitable material, at just above its glass transition temperature Tg. Allowing the PTFE material to cool then yields a surface conditioned for deposition of planarization or other layers. Some amount of treatment, using the conditioning methods just described, may be used to improve the surface of substrate 20 following the deposition of particulate material 16. n yet another embodiment, as shown in Figure 4 a first plastic material is provided as a base substrate 24. Then, a composition 26 is coated onto the surface of this base substrate, where the composition includes one plastic binder material that is mixed with at least one particulate material 16. This process thus provides a surface that is suitably treated for depositing one or more layers, which may be, for example, planarization layer 14 as shown in Figure 4, an isolation layer, or an electronically active semiconductor layer used to form some portion of a thin-film electronic device. Planarization Materials
In addition to spun-on glass, the following planarization materials may be used in different embodiments:
• Benzocyclobutene (BCB). This material must be semiconductor grade, without mobile ions.
• Acrylic.
• Tetraethoxysilane (TEOS).
Relative to other solutions that attempt to employ plastic substrates, the method of the present invention promotes improved adhesion of the TFT layers, since glass, ceramic, or other suitable particulate provides better adhesion than does the plastic binder alone. The use of particulate material 16 increases the temperature limits before loss of dimensional stability, allowing device fabrication at higher temperatures.
The method of the present invention is advantaged since it allows the formation of TFT components directly on a flexible substrate, without the need for intermediate steps such as lamination. This method can be particularly well-suited to web or roll-to-roll fabrication, in which a substrate sheet would be unwound from a first roll, undergo surface conditioning by embedding particulate material 16 as described earlier, and be further processed or rewound on a second roll for future use.
A broad range of particulate substances of various types could be employed as particulate material 16 or a mixture of particulate materials used, taking advantage of favorable properties of multiple materials. Additional types of surface conditioning could be used at various points in the electronic device fabrication process, using tools such as plasma etching, as noted earlier. One or both sides of a sheet of substrate material can be treated using the method of the present invention. Various methods, including embossing, can be used for preparing the surface of substrate 20 prior to applying planarization layer 14 and TFT device formation. Components formed on substrate 20 or on planarization layer 14 can include optical components, including refractive components such as one or more lenses or lenslets. Lenslets could be spatially aligned with TFT components, to provide input or output pixel elements. The electronic device formed on substrate 20 can be used to provide signals to or from any of a number of different types of components and would have particular applications for image display pixels or image sensing pixels. For example, the electronic device formed on the substrate 20 surface can be coupled with a corresponding liquid crystal pixel, light-emitting diode pixel, or organic light-emitting diode pixel for display, for example. For image sensing, the electronic device formed on the substrate 20 surface can be coupled with a stimulable phosphor pixel or with another type of sensor pixel, including a biological detector. The present invention also relates to multi-layer substrates in which the bottom layer is optimized for properties related to the carrier (such as adhesive properties to the carrier), the top layer is optimized for properties related to the electronic device (such as adhesion to the device layers) and intervening layers are optimized to achieve selected properties, such as optical, electronic, thermal, magnetic or chemical properties.
Thus, what is provided is an apparatus and method for fabrication of an electronic device on a substrate.
PARTS LIST electronic device thin-film component layer particulate material carrier substrate surface base substrate composition

Claims

CLAIMS:
1. A method of manufacturing an electronic device comprising: a) providing a substrate that comprises at least one plastic 5 material; b) embedding a particulate material in at least one surface of the substrate; and c) forming a thin film electronic device on said surface with said particulate material. 10
2. The method of claim 1 wherein said particulate material is a fiber.
3. The method of claim 1 further comprising:
15 d) embedding the particulate material in a second surface of the substrate; and e) forming a thin film electronic device on said second surface having said embedded particulate material.
20 4. The method of claim 1 wherein said electronic device comprises one or more thin film transistors.
5. A method of manufacturing an electronic device comprising:
25 a) providing a substrate that comprises at least one plastic material; b) embedding a particulate material in at least one surface of the substrate; c) applying a planarization material to the surface of the 30 substrate having the embedded particulate material, forming a planarization layer thereby; and d) forming a thin film electronic device on said surface with said particulate material.
6. The method of claim 3 wherein said electronic device comprises one or more thin film transistors.
7. A method of manufacturing an electronic device comprising: a) providing a substrate that comprises at least one plastic material as a base substrate; b) coating a composition material onto at least one surface of the base substrate, wherein the composition material comprises at least one plastic binder material and at least one particulate material, forming at least one coated surface thereby; and c) forming a thin film electronic device on said at least one coated surface.
8. A method of manufacturing an electronic device comprising: a) providing a substrate that comprises at least one plastic material and at least one particulate material; b) conditioning at least one surface of the substrate to increase the proportion of particulate material to plastic material at that surface; and c) forming a thin film electronic device on said at least one conditioned surface.
9. The method of claim 8 wherein conditioning at least one surface comprises chemical removal of the plastic material at the surface.
10. The method of claim 8 wherein conditioning at least one surface comprises removal of plastic material at the surface by plasma etching.
11. The method of claim 8 wherein conditioning at least one surface comprises removal of plastic material at the surface by heating.
12. The method of claim 8 wherein conditioning at least one surface comprises removal of plastic material at the surface by exposure to supercritical CO2.
13. The method of claim 8 wherein conditioning at least one surface comprises removal of plastic material at the surface by laser ablation.
14. The method of claim 8 wherein conditioning at least one surface comprises removal of plastic material at the surface by thermal decomposition in a vacuum. .
15. The method of claim 8 wherein conditioning at least one surface comprises removal of plastic material at the surface by corona discharge treatment.
16. A method of manufacturing an electronic device comprising: a) providing a substrate that comprises polytetrafluoroethylene (PTFE) and at least one particulate material; and b) forming a thin film electronic device on at least one surface of said substrate.
17. A method of manufacturing an electronic device comprising: a) providing a substrate that comprises polytetrafluoroethylene (PTFE), at least one other plastic material, and at least one particulate material; and b) forming a thin film electronic device on at least one surface of said substrate.
18. A method of manufacturing an electronic device comprising: a) providing a substrate comprising polytetrafluoroethylene (PTFE) and at least one particulate material; b) laminating said substrate to a carrier; and c) forming an electronic device on the substrate.
19. A method of manufacturing an electronic device comprising: a) providing a substrate comprising polytetrafluoroethylene (PTFE), at least one particulate material, and at least one other plastic material; b) laminating said substrate to a carrier; c) forming an electronic device on the substrate; and d) delaminating the substrate containing the electronic device from the carrier.
20. The method of claim 17 wherein the at least one other plastic material is polyimide.
21. The method of claim 1 wherein the plastic material is taken from a group consisting of polyethylene terephthalate (HS-PET)5 polyethylenenapthalate (PEN), polycarbonate (PC), polyarylate (PAR), polyetherimide (PEI), polyethersulphone (PES), polyimide (PI), Teflon poly(perfluoro-alboxy)fluoropolymer (PFA), poly(ether ether ketone) (PEEK), poly(ether ketone) (PEK), poly(ethylene tetrafluoroethylene)fluoropolymer (PETFE), and poly(methyl methacrylate), acrylate/methacrylate copolymer (PMMA), cyclic polyolefins, ethylene-chlorotrifluoro ethylene (E-CTFE), poly- tetrafluoro-ethylene (PTFE), and high density polyethylene (HDPE).
22. The method of claim 1 wherein the particulate material is selected from a group consisting of glass, ceramics, metals, plastics, and fiberglass.
23. The method of claim 5 wherein the step of forming a thin film electronic device comprises spin coating a thin-film semiconductor material onto said surface.
24. The method of claim 1 wherein the step of embedding a particulate material comprises: a) heating the plastic material to a temperature near its glass transition temperature Tg; and b) applying the particulate material to the plastic material.
25. The method of claim 1 further comprising depositing a dielectric material onto said at least one surface of the substrate.
26. The method of claim 25 wherein the dielectric material comprises spun-on glass.
27. The method of claim 1 wherein the particulate material comprises particles that are substantially aligned with respect to one or two directions.
28. The method of claim 1 wherein the particulate material is magnetic.
29. The method of claim 1 wherein the particulate material comprises a ferromagnetic material.
30. The method of claim 1 wherein the particulate material is conductive.
31. The method of claim 1 wherein the plastic material comprises a combination of more than one plastic.
5 32. The method of claim 1 further comprising removing the substrate from a carrier.
33. The method of claim 1 wherein the particulate material is selected from a group consisting of fibers, rods, or platelets.
10
34. The method of claim 1 further comprising laminating the substrate onto another device.
35. A method of manufacturing an electronic device 15 comprising: a) providing a substrate that comprises a plastic material and at least one particulate material; b) mounting the substrate on a carrier layer; c) conditioning the surface of the substrate for deposition 20 of thin-film semiconductor materials; d) depositing a layer of thin-film semiconductor material onto the substrate; and e) forming a pattern by selectively removing portions of ^_ the semiconductor material.
25
36. The method of claim 35 further comprising: e) removing the substrate from the carrier layer using heat.
37. The method of claim 1 wherein the plastic material is 30 substantially transparent.
38. The method of claim 37 wherein the refractive index of the plastic material is substantially equal to the refractive index of the particulate material.
39. The method of claim 37 wherein the refractive index of the plastic material differs by more than 0.1 from the refractive index of the particulate material.
40. The method of claim 1 wherein the plastic material is substantially opaque.
41. The method of claim 1 wherein the plastic material comprises a light-absorptive colorant.
42. The method of claim 1 wherein the particulate material comprises a light-absorptive colorant.
43. The method of claim 5 wherein the planarization material comprises a light-absorptive colorant.
44. A method of manufacturing an electronic device comprising: a) providing a substrate that comprises at least one plastic material; b) forming a pattern on at least one surface of said substrate; c) embedding a particulate material into the at least one surface of said substrate; d) applying a planarization material to the surface of the substrate having the embedded particulate material, forming a planarization layer thereby; and e) forming a thin film electronic device on said surface with said particulate material.
45. The method of claim 44 wherein forming a pattern comprises embossing.
46. The method of claim 44 wherein the pattern comprises one or more lens elements.
47. The method of claim 44 wherein the one or more lens elements are spatially aligned with the thin film electronic devices formed on said surface.
48. The method of claim 1 wherein the step of providing the substrate comprises unwinding the substrate from a roll.
49. The method of claim 48 further comprising re-winding the substrate having the electronic device formed thereon onto a roll.
50. The method of claim 1 further comprising coupling the electronic device formed on said surface with a liquid crystal pixel.
51. The method of claim 1 further comprising coupling the electronic device formed on said surface with a light-emitting diode pixel.
52. The method of claim 1 further comprising coupling the electronic device formed on said surface with an organic light-emitting diode pixel.
53. The method of claim 1 further comprising coupling the electronic device formed on said surface with a stimulable phosphor pixel.
54. The method of claim 1 further comprising coupling the electronic device formed on said surface with a sensor pixel.
PCT/US2007/016085 2006-07-31 2007-07-16 Flexible substrate with electronic devices formed thereon WO2008016479A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP07796875A EP2047513A1 (en) 2006-07-31 2007-07-16 Flexible substrate with electronic devices formed thereon
JP2009522771A JP2009545878A (en) 2006-07-31 2007-07-16 Flexible substrate on which electronic devices are formed

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11/461,080 2006-07-31
US11/461,080 US7678701B2 (en) 2006-07-31 2006-07-31 Flexible substrate with electronic devices formed thereon

Publications (1)

Publication Number Publication Date
WO2008016479A1 true WO2008016479A1 (en) 2008-02-07

Family

ID=38669806

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2007/016085 WO2008016479A1 (en) 2006-07-31 2007-07-16 Flexible substrate with electronic devices formed thereon

Country Status (5)

Country Link
US (2) US7678701B2 (en)
EP (1) EP2047513A1 (en)
JP (1) JP2009545878A (en)
TW (1) TW200814333A (en)
WO (1) WO2008016479A1 (en)

Families Citing this family (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7977170B2 (en) * 2006-10-03 2011-07-12 Eastman Kodak Company Flexible substrate with electronic devices and traces
US7913381B2 (en) * 2006-10-26 2011-03-29 Carestream Health, Inc. Metal substrate having electronic devices formed thereon
KR101408510B1 (en) * 2007-05-18 2014-06-17 삼성전자주식회사 Flexible Substrate for Display and Device Using The Same
US8502259B2 (en) 2008-01-11 2013-08-06 Industrial Technology Research Institute Light emitting device
US20090200543A1 (en) * 2008-02-08 2009-08-13 Roger Stanley Kerr Method of forming an electronic device on a substrate supported by a carrier and resultant device
US8800138B2 (en) * 2008-02-08 2014-08-12 Carestream Health, Inc. Method for conditioning a substrate surface for forming an electronic device thereon and resultant device
US20100032702A1 (en) * 2008-08-11 2010-02-11 E. I. Du Pont De Nemours And Company Light-Emitting Diode Housing Comprising Fluoropolymer
TWI400673B (en) * 2009-02-18 2013-07-01 Prime View Int Co Ltd Flexible display panel and method of manufacturing the same
US8074349B2 (en) * 2009-04-16 2011-12-13 Carestream Health, Inc. Magnetic hold-down for foil substrate processing
GB0909721D0 (en) * 2009-06-05 2009-07-22 Plastic Logic Ltd Dielectric seed layer
TWI387138B (en) * 2009-07-10 2013-02-21 Ind Tech Res Inst Magnetic light eitting device, magnetic light eitting apparatus and semi-conductive nitride template
EP2404650A1 (en) * 2010-07-09 2012-01-11 Bayer MaterialScience AG Method and device for solid-liquid separation of solid-liquid suspensions
WO2012043971A2 (en) * 2010-09-29 2012-04-05 포항공과대학교 산학협력단 Method for manufacturing a flexible electronic device using a roll-shaped motherboard, flexible electronic device, and flexible substrate
USRE49869E1 (en) * 2015-02-10 2024-03-12 iBeam Materials, Inc. Group-III nitride devices and systems on IBAD-textured substrates
KR20160127892A (en) * 2015-04-27 2016-11-07 삼성디스플레이 주식회사 Flexible substrate and display device including the same
JP7044802B2 (en) 2017-04-04 2022-03-30 ダブリュ．エル．ゴア アンド アソシエーツ，ゲゼルシャフト ミット ベシュレンクテル ハフツング Dielectric complex with reinforced elastomer and integrated electrodes
JP2019121734A (en) * 2018-01-10 2019-07-22 株式会社Ｊｏｌｅｄ Semiconductor device and display device
CA3097115C (en) 2018-05-08 2023-03-07 W. L. Gore & Associates, Inc. Flexible and stretchable printed circuits on stretchable substrates
EP3791698A1 (en) 2018-05-08 2021-03-17 W. L. Gore & Associates Inc Flexible printed circuits for dermal applications
KR20210006963A (en) 2018-05-08 2021-01-19 더블유.엘. 고어 앤드 어소시에이트스, 인코포레이티드 Durable flexible printed circuits on stretchable and non-stretchable substrates
CN109285462B (en) * 2018-12-12 2021-04-20 武汉天马微电子有限公司 Flexible display panel, manufacturing method thereof and flexible display device
KR102084519B1 (en) * 2019-07-16 2020-03-04 주식회사 오플렉스 Backplate film comprising ultraviolet(UV) curable adhesive layer and method for manufacturing organic light emitting display device using the same

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6680485B1 (en) * 1996-03-05 2004-01-20 The Regents Of The University Of California Thin film transistors on plastic substrates
US20040014265A1 (en) * 2002-04-24 2004-01-22 E Ink Corporation Processes for forming backplanes for electro-optic displays
US20040079941A1 (en) * 2002-10-18 2004-04-29 Shunpei Yamazaki Semiconductor apparatus and fabrication method of the same
US6762124B2 (en) * 2001-02-14 2004-07-13 Avery Dennison Corporation Method for patterning a multilayered conductor/substrate structure
US20050163968A1 (en) * 2004-01-20 2005-07-28 Hanket Gregory M. Microfiller-reinforced polymer film
GB2430547A (en) * 2005-09-20 2007-03-28 Seiko Epson Corp A method of producing a substrate having areas of different hydrophilicity and/or oleophilicity on the same surface

Family Cites Families (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5237436A (en) * 1990-12-14 1993-08-17 North American Philips Corporation Active matrix electro-optic display device with light shielding layer and projection and color employing same
US5891552A (en) * 1996-01-04 1999-04-06 Mobil Oil Corporation Printed plastic films and method of thermal transfer printing
US6492026B1 (en) * 2000-04-20 2002-12-10 Battelle Memorial Institute Smoothing and barrier layers on high Tg substrates
CA2410238A1 (en) * 2000-06-19 2001-12-27 Carlton Brooks Methods and devices for enhancing bonded substrate yields and regulating temperature
JP2002108250A (en) * 2000-09-29 2002-04-10 Sharp Corp Active matrix driven self-luminous display device and manufacturing method therefor
DE10059498A1 (en) * 2000-11-30 2002-06-13 Infineon Technologies Ag Substrate with a semiconducting layer, electronic component with this substrate, electronic circuit with at least one such electronic component, printable composition and method for producing a substrate
US7535624B2 (en) * 2001-07-09 2009-05-19 E Ink Corporation Electro-optic display and materials for use therein
US7110163B2 (en) * 2001-07-09 2006-09-19 E Ink Corporation Electro-optic display and lamination adhesive for use therein
JP2003045234A (en) * 2001-07-26 2003-02-14 Dainippon Printing Co Ltd Transparent conductive film
TWI308231B (en) * 2001-08-28 2009-04-01 Sipix Imaging Inc Electrophoretic display
US20030193796A1 (en) * 2002-04-15 2003-10-16 Heeks Stephen K. Light-emitting devices
EP1362682A1 (en) 2002-05-13 2003-11-19 ZBD Displays Ltd, Method and apparatus for liquid crystal alignment
JP2004200365A (en) * 2002-12-18 2004-07-15 Konica Minolta Holdings Inc Organic thin film transistor element
TWI330269B (en) * 2002-12-27 2010-09-11 Semiconductor Energy Lab Separating method
US20050216075A1 (en) * 2003-04-08 2005-09-29 Xingwu Wang Materials and devices of enhanced electromagnetic transparency
JP4233433B2 (en) * 2003-11-06 2009-03-04 シャープ株式会社 Manufacturing method of display device
JP4554344B2 (en) * 2003-12-02 2010-09-29 株式会社半導体エネルギー研究所 Method for manufacturing semiconductor device
EP1707590B1 (en) * 2003-12-26 2008-12-10 Toyo Boseki Kabushiki Kaisha Polyimide film
US8053171B2 (en) * 2004-01-16 2011-11-08 Semiconductor Energy Laboratory Co., Ltd. Substrate having film pattern and manufacturing method of the same, manufacturing method of semiconductor device, liquid crystal television, and EL television
WO2005093864A1 (en) * 2004-03-25 2005-10-06 National Institute Of Advanced Industrial Science And Technology Thermoelectric conversion element and thermoelectric conversion module
JP5089027B2 (en) * 2004-05-28 2012-12-05 株式会社半導体エネルギー研究所 Semiconductor device
CN101023532A (en) * 2004-07-27 2007-08-22 株式会社昆腾14 Light-emitting element, light-emitting device and information display
JP4715149B2 (en) * 2004-09-30 2011-07-06 ソニー株式会社 Method for manufacturing thin film semiconductor device
US7582904B2 (en) * 2004-11-26 2009-09-01 Semiconductor Energy Laboratory Co., Ltd. Semiconductor device, display device and method for manufacturing thereof, and television device
US20060180890A1 (en) * 2005-01-18 2006-08-17 Naugler W E Jr Top emission flat panel display with sensor feedback stabilization
TWI408734B (en) * 2005-04-28 2013-09-11 Semiconductor Energy Lab Semiconductor device and method for manufacturing the same
TWI402935B (en) * 2005-05-17 2013-07-21 Koninkl Philips Electronics Nv Colour active martix displays
US8097112B2 (en) * 2005-06-20 2012-01-17 Panasonic Corporation Method for manufacturing membrane-electrode assembly
KR101102152B1 (en) * 2005-06-28 2012-01-02 삼성전자주식회사 Method for fabricating Organic Thin Film Transistor and Organic Thin Film Transistor using the same
US20070002199A1 (en) * 2005-06-30 2007-01-04 Semiconductor Energy Laboratory Co., Ltd. Liquid crystal display device and method for manufacturing the same
US20070007579A1 (en) * 2005-07-11 2007-01-11 Matrix Semiconductor, Inc. Memory cell comprising a thin film three-terminal switching device having a metal source and /or drain region
US7235736B1 (en) * 2006-03-18 2007-06-26 Solyndra, Inc. Monolithic integration of cylindrical solar cells

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6680485B1 (en) * 1996-03-05 2004-01-20 The Regents Of The University Of California Thin film transistors on plastic substrates
US6762124B2 (en) * 2001-02-14 2004-07-13 Avery Dennison Corporation Method for patterning a multilayered conductor/substrate structure
US20040014265A1 (en) * 2002-04-24 2004-01-22 E Ink Corporation Processes for forming backplanes for electro-optic displays
US20040079941A1 (en) * 2002-10-18 2004-04-29 Shunpei Yamazaki Semiconductor apparatus and fabrication method of the same
US20050163968A1 (en) * 2004-01-20 2005-07-28 Hanket Gregory M. Microfiller-reinforced polymer film
GB2430547A (en) * 2005-09-20 2007-03-28 Seiko Epson Corp A method of producing a substrate having areas of different hydrophilicity and/or oleophilicity on the same surface

Also Published As

Publication number Publication date
US20080026581A1 (en) 2008-01-31
US20100136777A1 (en) 2010-06-03
TW200814333A (en) 2008-03-16
US7964507B2 (en) 2011-06-21
EP2047513A1 (en) 2009-04-15
JP2009545878A (en) 2009-12-24
US7678701B2 (en) 2010-03-16

Similar Documents

Publication Publication Date Title
US7678701B2 (en) Flexible substrate with electronic devices formed thereon
US8288214B2 (en) Flexible substrate with electronic devices and traces
US10459590B2 (en) Touch panel and manufacturing method thereof
US7951726B2 (en) Organic/inorganic hybrid thin film passivation layer for blocking moisture/oxygen transmission and improving gas barrier property
JP5689258B2 (en) Manufacturing method of flexible TFT substrate
KR20080101488A (en) Flexible substrate for display and device using the same
CN101504920A (en) Method for forming an electronic device on a flexible metallic substrate and resultant device
CN102001201B (en) Laminate film and composite film
KR102202997B1 (en) Laminated structure manufacturing method, laminated structure, and electronic apparatus
TW201218147A (en) Method for producing transparent substrate
CN103579531B (en) The method of the elastomer mask plate that can peel off is formed at surface of polymer substrates
KR101669317B1 (en) Flexible substrate for display device, method for preparing the same and display device using the same
US20090200543A1 (en) Method of forming an electronic device on a substrate supported by a carrier and resultant device
CN109244238B (en) Flexible substrate for display panel and manufacturing method thereof
KR20120053621A (en) Transparent flexible film and method for manufacturing thereof
JP2008262955A (en) Semiconductor device and manufacturing method thereof
CN110462861A (en) It is incorporated to the electronic building brick and its manufacturing method of laminated substrate
US9627420B2 (en) Method for forming an electronic device on a flexible substrate supported by a detachable carrier
KR100550377B1 (en) Passivation and Gas Barrier Layer Structure for Flexible Flat Panel Display and its manufacturing methods
Souk et al. A practical approach to processing flexible displays
JP2003048293A (en) Multi-layer resin sheet
JP5076267B2 (en) Polymer sheet manufacturing method and display element substrate using the same
KR20100098319A (en) Method for conditioning a substrate surface for forming an electronic device thereon and resultant device
JP2010251361A (en) Method of manufacturing semiconductor device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 07796875

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2007796875

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 2009522771

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

NENP Non-entry into the national phase

Ref country code: RU