A semiconductor chip package and a printed circuit board having an embedded semiconductor chip package are disclosed. The semiconductor chip package may include a semiconductor chip that has at least one chip pad formed on one side, and a capacitor formed on the other side of the semiconductor chip.

1. Technical Field
The present invention relates to a semiconductor chip package and a printed circuit board having an embedded semiconductor chip package.
2. Description of the Related Art
In current electronic products, especially portable electronic devices, etc., the variety of consumer demands is continuously increasing. In particular, the demands for multi-functionality, compact sizes, light weight, high speeds, low costs, increased portability, real time access to the wireless Internet, and sophisticated designs are goading developers, designers, and manufacturers alike to provide superior products. Increased competition in providing such products have led to more frequent releases of newer models, exacerbating the burden on those involved. The demands related to mobile products, such as cell phones, PDA's, digital cameras, and laptops, in particular, are greater than ever, one result of which is that the electronic parts for these products are being modularized and integrated, to implement multi-functionality, compact sizes, light weight, and low costs, etc.
In the case of embedding a passive component in a semiconductor chip, there is a limit to the types of material that can be used when considering compatibility with semiconductor processes. Embedding the passive component may also increase chip size or increase cost, and thus impose a limit on applicability. Another method is to embed the passive component in a semiconductor chip package. Methods of forming a capacitor directly inside the package include methods that provide thick film types and methods that provide thin film types.
In the case of a thick film capacitor, a composite material may be used that includes a dielectric filler dispersed in the epoxy resin used for the insulation. Although this may provide superb workability, the dielectric constant may be low, to be about 30, making it difficult to implement a high-capacitance capacitor. On the other hand, a thin film capacitor may provide a high capacitance density, but there is a higher likelihood of electrical leakage caused by defects in the surface of the surface of the copper foil used for the lower electrode.
In order to form a passive component in a semiconductor chip package with greater reliability, a technique has also been conceived of forming a capacitor on the rewiring layer of a semiconductor package. In this case, however, the capacitor may be formed in-between the rewiring lines, so that there is a limit to the size of the capacitor. The material used for the capacitor may also be limited to those that are compatible with the rewiring process, and the degree of freedom may be very low in planning for the processes, with regards, for example, process temperatures and patterning methods, etc.

Semiconductor chip package and printed circuit board


The invention relates to new processes for the preparation of antireflective coatings and coated substrates, as well as articles produced by these processes. These coatings can include one or more layers made of materials which form nano-structured and/or nano-porous surfaces. The process can include applying a cross-linkable hard coat to a substrate, partially curing or cross-linking the hard coat, and then applying a second coat carried by a solvent or mixture of solvents capable of swelling the partially cured hard coat. The second coat is then cross-linked and grafted to the hard coat to produce a durable coated substrate with antireflective properties.

The drive for ever smaller features sizes in surfaces and coatings has been brought about through a desire to achieve attractive properties for applications in, for example micro-electronics, anti-reflective coatings for displays and super-hydrophobic or even self cleaning surfaces. The numerous techniques for preparation of nano-structured surfaces or coatings can be regarded as fitting into one of two classes.
The first class is know as the top down approach and is primarily concerned with the manufacture of progressively smaller and smaller feature sizes in photolithographic processes. Top down lithographic techniques are especially applied where regular and straight features are required as is the case for photo-resists in the microprocessor field. Manufacture of random, irregular structures and structuring via these techniques over large surface areas (dm2 to m2) is extremely difficult, time consuming and therefore expensive.
The second class of nano-structuring techniques can be regarded as so-called bottom up techniques and are usually based on phase separation, which can be achieved in two ways. Firstly, by phase separation of two incompatible polymers (e.g. Polymethylmethacrylate and Polystyrene, Steiner et al., Science, Vol 283, pg 520-522, 1999), during the evaporation of a solvent. After that the nano-structure is formed by removal of one of the polymers by a selective solvent, that dissolves only one of the polymers.
Secondly, phase separation can be induced by crosslinking a mixture of components where at least one component is capable of crosslinking and at least one other is not (Ibn-Elhaj and Schadt, Nature, Vol 410, pg 796-799, 2001). The mixture is homogeneous prior to crosslinking and the phase separation occurs during the formation of the crosslinked network. The nano-structure is formed by removal of the non-crosslinkable component. As phase separation is a dynamic process, the size and distribution of the features formed under both of the above techniques is strongly dependent on the rate or kinetics of the phase separation. Parameters such as temperature and in the case of photo-induced crosslinking the photo-initiator concentration and/or radiation intensity all will affect the feature size of the nano-structured coatings. Therefore processing is complicated and reproducibility is poor. Also the necessary washing to remove one of the components is a sizable hurdle in the commercialisation of such technologies, especially for large surface areas. Thus, there is a need for an simple technique that allows the manufacture of nano-structured coatings.
Preparation of surface nano-structured and/or nano-porous coatings or films can be achieved by a process which includes the steps of
a) applying a mixture, which mixture comprises
                i) reactive nano-particles, having reactive organic groups on their surface        ii) a solvent        iii) optionally a compound having at least one polymerisable group in an amount that is small enough to allow the formation of a nano-structured surface after cure of the formulation,to a substrate,b) polymerising the mixture on the substrate.
By using no or only a little of the compound having at least one polymerisable group, a coating or a film is obtained with the process of the present invention having a nano-structured surface. Furthermore the coating or film has favourable mechanical properties and adheres well on several substrates. The coating or film has a variety of applications, among which are films or coatings having super hydrophobic properties and especially coatings having anti-reflective properties.
A new process for applying an antireflective coating to a substrate is also disclosed. The process comprises the steps of                a) applying a first coating to the substrate, said first coating being cross-linkable,        b) partially cross-linking the first coating,        c) providing a second coating, said second coating being cross-linkable and being carried in a solvent capable of partially swelling the first coating,        d) applying the second coating and solvent to the partially cross-linked first coating, and        e) cross-linking the second coating.The first coating can be a hard coat and the second coating a layer with a nano-structured surface as described herein. By partially cross-linking the first coating and swelling it with a solvent, good adhesion between the first and second coatings can be achieved. As a result, use of the process of the present invention can result in a durable, scratch-resistant antireflective coated substrate which is more readily manufacturable, is produced using fewer processing steps and in higher yields, and is less expensive than conventional antireflective coatings.
From U.S. Pat. No. 2,601,123 a coating for reducing surface reflections is known for the coating of glass substrates. The coating however must be sintered at very high temperatures, so that it is not suitable for application on polymer substrates. Furthermore it relates to very old and abandoned technology.
It is known from U.S. Pat. No. 5,582,859 that anti-reflective properties may be obtained by preparing a multilayer system of coatings in which each coating has a carefully selected thickness and refractive index. However, multilayer coatings suffer from two sets of problems. The first is that the anti-reflective performance of multilayer coatings suffers from angle-dependency (D. Chen, Solar Energy Materials & Solar Cells, 86 (2001) 313-336). This means that transmission will vary from the normal to oblique angles. Secondly, reproducible processing of such multilayer coatings with precisely controlled thickness and optical properties is difficult and therefore costly and time-consuming.
Also in U.S. Pat. No. 6,455,103 a similar multi-layer anti-reflective coating is applied, giving the same problems as explained above.
In DE 19746885 A1 a process for coating a substrate with a mixture comprising reactive nanoparticles is disclosed. However there is no teaching given how to obtain the surface nano-structured and/or nanoporous coating of the present invention and the anti-reflective properties are poor.
Since the reactive nano-particles in step a) always have more than one reactive group on their surface, the polymerisation in step b results in the formation of a crosslinked phase, comprising the nanoparticles interconnected. Therefore, in this text, the terms polymerise or polymerisation is used interchangeably with cross-linking or cross-linked and polymerisable group is used interchangeably with cross-linking group.
Within the context of the invention the term surface nano-structured coatings refers to coatings having a surface roughness, and in which surface the dimensions of the features on the surface are larger than or equal to the smallest cross-sectional dimension of an individual nano-particle. Preferably the dimensions of the features are smaller than 1200 nm, more preferably smaller than 800 nm, still more preferably smaller than 400 nm, most preferably smaller than 300 nm. There also may be nanosized voids in the coating.
In the framework of this invention the term "nano-particles" is defined as particles of which the majority has a diameter of less than a micrometer. Within the framework of the invention a nano-particle is elongated when the aspect ratio, defined as the length divided by the diameter is greater than unity. The preparation of reactive nano-particles as such is known in the art, and has been described in e.g. U.S. Pat. No. 6,025,455. In a preferred embodiment of the process according to the invention, all nano-particles are reactive.
The compound having at least one polymerisable group is in this text also referred to as both diluent or reactive diluent. In this text the term hard coat refers to a coating comprising nano-particular species, optionally reactive nano-particular species, in a crosslinked polymeric network, wherein the volume fraction of reactive diluent is such that there are no or at least hardly no void spaces and/or surface nano-structures present in the coating.
For obtaining the nano-structured surface it is important that no or a relatively small amount of the reactive diluent and optional further components is present in the coating obtained with the process according to the invention. If a too high amount of reactive diluent and optional further components is used, the nano particles will be embedded and a coating having a smooth surface and not having any pores will be obtained. Normally the amount of reactive diluent and eventually further components in the final coating (after evaporation of the solvent) as expressed in volume fraction may not exceed 1-(the random close packing volume traction of the reactive nanoparticles). The skilled person can easily determine the amount of diluent and eventually further additives by varying the amount and measuring the surface roughness or a parameter as for instance the transmission or the reflection of the coating as a function of this amount. Above a certain concentration of reactive diluent (or optionally further additives) the surface roughness of the coating has vanished and no special anti-reflective properties are detected any more.
Furthermore the invention also relates to the mixture for the preparation of nano-structured and/or nano-porous coatings, the coatings or films obtained from the process according to the invention, articles comprising said coatings and the use of said coatings.
Reactive Nano-Particles
In a preferred embodiment, the majority of the nano-particles in the mixture according to the invention have a diameter of less than 400 nm, more preferably the majority of particles have a diameter of less than 50 nm. Most preferably all particles have a diameter of less than 50 nm. In a preferred embodiment, the majority of the nano-particles have a length in the range of 40 to 300 nm. Preferably, the particles used have such a dimensions that they do not (or not significantly) influence the transparency of the eventual coating. Most preferably the increase in haze of a transparent substrate comprising the coating in a thickness of 0.1 micrometer, compared to the substrate not yet comprising the coating is less than 2%, preferably less than 1%, most preferably less than 0.5%.
As will be obvious to anyone skilled in the art, the random packing density of the nano-particular species is determined by the shape and the relative size and size distribution of the nano-particles. Hence it may be advantageous to use nano-particles of differing shapes and sizes to precisely control the size of the surface nano-structures and/or nano-pores.
In a preferred embodiment, the reactive nano-particles have an aspect ratio greater than 1, more preferably, they have an aspect ratio (length/diameter) greater than 3, still more preferably greater than 5, and most preferably, they have an aspect ratio of greater than 10. If elongated reactive nano-particles are used it is possible to obtain a coating having even further improved anti-reflective properties or to use a higher concentration of reactive diluent, which gives better mechanical properties to the coating. More preferably the nanoparticles are wormlike. Of a wormlike nano particle the primary axis is curved.
Methods for determining the particle dimension include optical or scanning electron microscopy, or atomic force microscopy (AFM) imaging.
For measuring the dimensions of the nano-particles the particles are in a very dilute mixture applied on a surface in a thin layer, so that at a SEM photographic image of the layer, the single nano-particles are observable. Than from 100 nanoparticles, ad random selected, the dimensions are determined and the average value is taken. In case of particles having an aspect ratio above 1, like worm-shaped nano-particles, the total length is determined, from one end to the other end, by following the primary axis as projected in the plane of the photo. For the diameter the longest straight line that can be drawn from one side of the particle to the other side, perpendicular to the primary axis is taken.
In the process according to the invention the coating may comprise either organic or inorganic nano-particles. Examples of organic nano-particles are carbon nano-tubes or nano-spheres. Preferably, the nano-particles are inorganic nano-particles. Suitable inorganic particles are for example oxide particles. Preferred oxide particles are particles of an oxide selected from the group of aluminium oxide, silicium oxide, zirconium oxide, titanium oxide, antimony oxide, zinc oxide, tin oxide, indium oxide, and cerium oxide. It is also possible to use a mixture of particles from different oxides or to use particles of mixed oxides. Most preferably, the nano-particles are particles of aluminium oxide, zirconium oxide or silicium oxide. The refractive index of the coating and effective refractive index of the coating/air interface can in part be tuned by the choice of oxide used.
The nano-particles have reactive organic groups on their surface. Such reactive nano-particles may or may not comprise additional, non-reactive organic groups. Additional non-polymerisable groups may be used to tune the overall polarity and thus the hydrophobicity or hydrophilicity of the particle and the resultant coating. In a preferred embodiment of the process according to the invention, all nano-particles are reactive nanoparticles. The reactive groups of the nano-particles, and if present, the polymerisable groups of the diluent may polymerise in a homopolymerisation reaction or a copolymerisation reaction. In such a case the reactive groups are polymerisable groups. A copolymerisation reaction is possible when in the mixture different groups are present that can polymerise, for example if the groups of the particles and of the reactive diluent are different, or if mixtures of reactive diluent and reactive/or particles are used that comprise such different groups. It is also possible that the reactive groups of the nanoparticles react with a polymer network that is formed by the polymerisation of one or more reactive diluents. Important however, is that the nanoparticles are chemically interconnected in a cross-linked phase.
Preferably the reactive groups of the reactive nano-particles are polymerisable groups.
The preparation of reactive nano-particles as such is known in the art, and has been described in e.g. U.S. Pat. No. 6,025,455.
Substrates
A wide variety of substrates may be used as a substrate in the process according to the invention. Suitable substrates are for example flat or curved, rigid or flexible substrates including films of for example polycarbonate, polyester, polyvinyl acetate, polyvinyl pyrollidone, polyvinyl chloride, polyimide, polyethylene naphthalate, polytetrafluoro ethylene, nylon, polynorbornene or amorphous solids, for example glass or crystalline materials, such as for example silicon or gallium arsenide. Metallic substrates may also be used. Preferred substrates for use in display applications are for example glass, polynorbornene, polyethersulfone, polyethyleneterphtalate, polyimide, cellulose triacetate, polycarbonate and polyethylenenaphtalate.
A free-standing single layer anti-reflective film obtainable by a process according to the invention may be obtained by preparing a film or coating on a substrate and subsequently removing the film or coating from the substrate after crosslinking. The removal of the film or coating from the substrate should always take place after the crosslinking.
Application of the Mixture to a Substrate
The mixture may be applied onto the substrate by any process known in the art of wet coating deposition. Examples of suitable processes are spin coating, dip coating, spray coating, flow coating, meniscus coating, capillary coating and roll coating.
Preferably the mixture according to the invention is applied in a single layer. In this case it is possible that the mixture is applied on a further coating, as long as this is not a coating according to the invention.
Typically, the reactive nano-particles are mixed with at least one solvent and, optionally crosslinking initiator and optionally a reactive diluent, to prepare a mixture that is suitable for application to the substrate using the chosen method of application.
Solvent
In principle, a wide variety of solvents may be used. The solvent preferably has the ability to form stable suspensions of the reactive nano-particles in order to facilitate a random close packing arrangement of the reactive nano-particles upon application, i.e. after evaporation of the solvent.
Nano-particles typically are added to the mixture in the form of a suspension. The same solvent as used in the suspension may be used to adjust the mixture so that it has the desired properties. However, other solvents may also be used.
Preferably the solvent used evaporates after applying the mixture onto the substrate. In the process according to the invention, optionally the mixture nay after application to the substrate be heated or treated in vacuum to aid evaporation of the solvent.
Examples of solvent that may be suitable are 1,4-dioxane, acetone, acetonitrile, chloroform, chlorophenol, cyclohexane, cyclohexanone, cyclopentanone, dichloromethane, diethyl acetate, diethyl ketone, dimethyl carbonate, dimethylformamide, dimethylsulphoxide, ethanol, ethyl acetate, m-cresol, mono- and di-alkyl substituted glycols, N,N-dimethylacetamide, p-chlorophenol, 1,2-propanediol, 1-pentanol, 1-propanol, 2-hexanone, 2-methoxyethanol, 2-methyl-2-propanol, 2-octanone, 2-propanol, 3-pentanone, 4-methyl-2-pentanone, hexafluoroisopropanol, methanol, methyl acetate, methyl acetoacetate, methyl ethyl ketone, methyl propyl ketone, n-methylpyrrolidone-2, n-pentyl acetate, phenol, tetrafluoro-n-propanol, tetrafluoroisopropanol, tetrahydrofuran, toluene, xylene and water. Alcohols, ketones and esters based solvents may also be used, although the solubility of acrylates may become an issue with high molecular weight alcohols. Halogenated solvents (such as dichloromethane and chloroform) and hydrocarbons (such as hexanes and cyclohexanes), may also be suitable. Preferably methanol, methyl ethyl ketone or isopropanol are used.
Compound having at Least one Polymerisable Group (Also called "Diluent" or "Reactive Diluent")
In principle, a wide variety of materials are suitable to be used as the reactive diluent. The relative amount of reactive diluent with respect to the relative amount of reactive nano-particles must be so small that it allows formation of a nano-structured surface. A way of determining of a coating has a surface nano-structure and/or nano-pores, is to apply the coating to a transparent substrate, crosslinking, and subsequently measuring the transmission. Preferably the amount of reactive diluent and optional further components in the mixture is that low, that if applied as a coating at one side of a transparent substrate, in a thickness between 100-200 nm, there is an increase in transmission of light at at least one wave length between 400 and 800 nm of at least 0.5% relative to the same substrate without the coating. Preferably the increase in transmission is at least 0.75%, more preferably at least 1%, still more preferably at least 1.5%, still more preferably at least 2%, still more preferably at least 2.5%, most preferably at least 3%. The exact amount of reactive diluent depends on the particle size, shape, and size distribution, and can thus not be given exactly. In case of elongated nano particles the amount of diluent may be less than 40 wt %, relative to the total weight of the mixture as applied in step a) of the process according to the invention, however without taking the solvent into account (total weight of solid). Preferably, the amount of diluent is less than 20wt %. Although it is not necessary to use any diluent, the mechanical properties of the coating will generally be better when at least some diluent is present, e.g., at least 1 wt %, more preferably at least 2 wt. %, still more preferably at least 5 wt. %, most preferably at least 10 wt. %. With respect to this aspect the advantage of the elongated particles and of these especially the wormlike nano particles becomes evident, as it is possible with these particles to apply a relatively high amount of reactive diluent to obtain very favourable mechanical properties and yet still having a well developed nano-structured surface, resulting for example in good antireflective properties.
As mentioned, in principle a wide variety of materials are suitable to be used as the reactive diluent, for example monomers or oligomers having crosslinking groups. Monomers or oligomers having only one crosslinking group per molecule may be used, but preferably in combination with other crosslinking components that do have at least two crosslinking groups. Preferably monomers or oligomers having at least two or more crosslinking groups per molecule are used. It is also possible that the reactive diluent comprises a mixture of compounds that after the induction of crosslinking in step b, together form a crosslinked phase. The mixture may comprise compounds that are by itself crosslinking, such as for example different acrylates or it may comprise compounds that will not crosslink by itself but which form a crosslinked phase in combination with another compound after initiation of the crosslinking reaction, for example copolymerising systems comprising electron rich and electron poor double bonds such as for example maleate/vinyl ether copolymerising systems.
Examples of monomers suitable for use as a reactive diluent and having at least two crosslinking groups per molecule include monomers containing (meth)acryloyl groups such as trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, ethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polybutanediol di(meth)acrylate, tripropyleneglycol di(meth)acrylate, glycerol tri(meth)acrylate, phosphoric acid mono- and di(meth)acrylates, C7-C20 alkyl di(meth)acrylates, trimethylolpropanetrioxyethyl (meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, tris(2-hydroxyethyl) isocyanurate di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxy pentacrylate, dipentaerythritol hexacrylate, tricyclodecane diyl dimethyl di(meth)acrylate and alkoxylated versions, preferably ethoxylated and/or propoxylated, of any of the preceding monomers, and also di(meth)acrylate of a diol which is an ethylene oxide or propylene oxide adduct to bisphenol A, di(meth)acrylate of a diol which is an ethylene oxide or propylene oxide adduct to hydrogenated bisphenol A, epoxy (meth)acrylate which is a (meth)acrylate adduct to bisphenol A of diglycidyl ether, diacrylate of polyoxyalkylated bisphenol A, and triethylene glycol divinyl ether, adduct of hydroxyethyl acrylate, isophorone diisocyanate and hydroxyethyl acrylate (HIH), adduct of hydroxyethyl acrylate, toluene diisocyanate and hydroxyethyl acrylate (HTH), and amide ester acrylate.
Examples of suitable monomers having only one crosslinking group per molecule include monomers containing a vinyl group, such as N-vinyl pyrrolidone, N-vinyl caprolactam, vinyl imidazole, vinyl pyridine; isobornyl(meth)acrylate, bornyl (meth)acrylate, tricyclodecanyl(meth)acrylate, dicyclopentanyl(meth)acrylate, dicyclopentenyl(meth)acrylate, cyclohexyl(meth)acrylate, benzyl(meth)acrylate, 4-butylcyclohexyl(meth)acrylate, acryloyl morpholine, (meth)acrylic acid, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, methyl (meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, isopropyl(meth)acrylate, butyl (meth)acrylate, amyl(meth)acrylate, isobutyl(meth)acrylate, t-butyl(meth)acrylate, pentyl (meth)acrylate, caprolactone acrylate, isoamyl(meth)acrylate, hexyl(meth)acrylate, heptyl (meth)acrylate, octyl(meth)acrylate, isooctyl(meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl(meth)acrylate, decyl(meth)acrylate, isodecyl(meth)acrylate, tridecyl(meth)acrylate, undecyl(meth)acrylate, lauryl(meth)acrylate, stearyl(meth)acrylate, isostearyl (meth)acrylate, tetrahydrofurfuryl(meth)acrylate, butoxyethyl(meth)acrylate, ethoxydiethylene glycol(meth)acrylate, benzyl(meth)acrylate, phenoxyethyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, methoxyethylene glycol(meth)acrylate, ethoxyethyl(meth)acrylate, methoxypolyethylene glycol(meth)acrylate, methoxypolypropylene glycol(meth)acrylate, diacetone(meth)acrylamide, beta-carboxyethyl(meth)acrylate, phthalic acid (meth)acrylate, isobutoxymethyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, t-octyl (meth)acrylamide, dimethylaminoethyl(meth)acrylate, diethylaminoethyl(meth)acrylate, butylcarbamylethyl(meth)acrylate, n-isopropyl(meth)acrylamide fluorinated (meth)acrylate, 7-amino-3,7-dimethyloctyl(meth)acrylate, N,N-diethyl (meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, hydroxybutyl vinyl ether, lauryl vinyl ether, cetyl vinyl ether, 2-ethylhexyl vinyl ether; and compounds represented by the following formula (I)CH2═C(R6)—COO(R7O)m—R8  Formula Iwherein R6 is a hydrogen atom or a methyl group; R7 is an alkylene group containing 2 to 8, preferably 2 to 5 carbon atoms; and m is an integer from 0 to 12, and preferably from 1 to 8; R8 is a hydrogen atom or an alkyl group containing 1 to 12, preferably 1 to 9, carbon atoms; or, R8 is a tetrahydrofuran group-comprising alkyl group with 4-20 carbon atoms, optionally substituted with alkyl groups with 1-2 carbon atoms; or R8 is a dioxane group-comprising alkyl group with 4-20 carbon atoms, optionally substituted with methyl groups; or R8 is an aromatic group, optionally substituted with C1-C12 alkyl group, preferably a C8-C9 alkyl group, and alkoxylated aliphatic monofunctional monomers, such as ethoxylated isodecyl(meth)acrylate, ethoxylated lauryl(meth)acrylate, and the like.
Oligomers suitable for use as the reactive diluent are for example aromatic or aliphatic urethane acrylates or oligomers based on phenolic resins (ex. bisphenol epoxy diacrylates), and any of the above oligomers chain extended with ethoxylates. Urethane oligomers may for example be based on a polyol backbone, for example polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols, acrylic polyols, and the like. These polyols may be used either individually or in combinations of two or more. There are no specific limitations to the manner of polymerization of the structural units in these polyols. Any of random polymerization, block polymerization, or graft polymerization is acceptable. Examples of suitable polyols, polyisocyanates and hydroxyl group-containing (meth)acrylates for the formation of urethane oligomers are disclosed in WO 00/18696, which is incorporated herein by reference.
Combinations of compounds that together may result in the formation of a crosslinked phase and thus that in combination are suitable to be used as the reactive diluent are for example carboxylic acids and/or carboxylic anhydrides combined with epoxies, acids combined with hydroxy compounds, especially 2-hydroxyalkylamides, amines combined with isocyanates, for example blocked isocyanate, uretdion or carbodiimide, epoxies combined with amines or with dicyandiamides, hydrazinamides combined with isocyanates, hydroxy compounds combined with isocyanates, for example blocked isocyanate, uretdion or carbodiimide, hydroxy compounds combined with anhydrides, hydroxy compounds combined with (etherified) methylolamide ("amino-resins"), thiols combined with isocyanates, thiols combined with acrylates or other vinylic species (optionally radical initiated), acetoacetate combined with acrylates, and when cationic crosslinking is used epoxy compounds with epoxy or hydroxy compounds.
Further possible compounds that may be used as the reactive diluent are moisture curable isocyanates, alkoxy titanates, alkoxy zirconates, or urea-, urea/melamine-, melamine-formaldehyde or phenol-formaldehyde (resol, novolac types), or radical curable (peroxide- or photo-initiated) ethylenically unsaturated mono- and polyfunctional monomers and polymers, e.g. acrylates, methacrylates, maleate/vinyl ether), or radical curable (peroxide- or photo-initiated) unsaturated e.g. maleic or fumaric, polyesters in styrene and/or in methacrylates.
Method for Crosslinking or Polymerisation
Any cross-linking method that may cause the mixture to crosslink so that a coating is formed is suitable to be used in the process according to the invention. Suitable ways to initiate crosslinking are for example electron beam radiation, electromagnetic radiation (UV, Visible and Near IR), thermally and by adding moisture, in case moisture curable compounds are used. In a preferred embodiment crosslinking is achieved by UV-radiation. The UV-crosslinking may take place through a free radical mechanism or by a cationic mechanism, or a combination thereof. In another preferred embodiment the crosslinking is achieved thermally.
Initiator
An initiator may be present in the mixture to initiate the crosslinking reaction. The amount of initiator may vary between wide ranges. A suitable amount of initiator is for example between above 0 and 5 wt % with respect to total weight of the compounds that take part in the crosslinking reaction.
When UV-crosslinking is used to initiate crosslinking, the mixture preferably comprises a UV-photo-initiator. A photo-initiator is capable of initiating a crosslinking reaction upon absorption of light, thus, UV-photo-initiators absorb light in the Ultra-Violet region of the spectrum. Any known UV-photo-initiators may be used in the process according to the invention.
The coating according to the invention can be prepared in any desired thickness. The coatings according to the invention typically have a thickness ranging between 50 nm to several micrometer. In case of application as an anti-reflective coating the thickness is preferably between 50 and 200 nm, more preferably between 100 and 150 nm.
In a preferred embodiment, the nano-structured and/or nano-porous films or coatings according to the invention increases the optical transmission of a substrate on which they are present for at least a range of visible wavelengths of the electromagnetic spectrum. Therefore the coating shows a reflection of light, at at least one wavelength in the area between 400-800 nm, measured under normal incidence of less than 3%, preferably less than 2%, more preferably less than 1.5%, most preferably less than 1%, per coated side of the substrate in a coating layer thickness between 100-200 nm.
The combination of good mechanical properties as well as anti-reflective performance will allow for the use of these single layer anti-reflective hard-coats in applications were mechanical durability and anti-reflective performance on flat or on non-flat substrates are advantageous. These applications include anti-reflective coatings for automobile and airplane wind screens, displays in general, television tubes, flexible displays and lenses, for example in spectacles. It is possible that the anti-reflective coating is applied to the substrate as a single coating. It is also possible that before the application of the anti-reflection coating, the substrate is coated with a further coating, for example to improve the adhesion between the anti-reflective coating and the substrate. At least an advantage of the anti-reflective coating of the present invention is, that the coating, bringing the anti-reflective properties only needs to be applied in a single layer,
In yet a further embodiment the surface nano-structured and/nano-porous coating according to the invention can be used to affect the wetting properties of the coating.
Generally, a hydrophobic material or coating is characterised by a static contact angle of water of 90° or above.
Hydrophobic polymeric materials such as poly(tetrafluorethene) (PTFE) or polypropylene (PP) have been available for decades. These materials suffer from a limited hydrophobicity, as well as inferior mechanical properties as compared to engineering materials or highly crosslinked coatings. For instance, PP has a static contact angle of water of roughly 100° whereas PTFE, which is amongst the most hydrophobic polymeric material known, has a static contact angle of water of roughly 112°.
Some hydrophobic coatings are being referred to in the art as superhydrophobic coatings. Superhydrophobic coatings are generally defined by a static water contact angle above 140° (Nun, Oles & Schleich, Macromol. Symp. 187 (2002) 677-682).
Within the framework of the invention, a combination of surface roughness, due to surface nano-structures and/or nano-pores, together with polar surface chemistry achieves static water contact angles below 60°, preferably below 40°. Conversely, the coating may also be affected so that the static water contact angle is above 90° and preferably 120° if the surface chemistry of the nano-structured and/nano-porous coating is apolar, for example via the presence of apolar surface modifying groups on the nano-particles.
Combining the wetting properties with the anti-reflection properties, the surface nano-structured and/or nano-porous films or coatings according to the invention increases the optical transmission of a substrate on which they are present to visible wavelengths of the electromagnetic spectrum while simultaneously exhibiting a static water contact angle of above 90°, preferably 120° and most preferably 140°.
Furthermore due to the surface nano-structures and/or nano pores other properties such as low refractive index, low optical dissipation (low optical loss), low dielectric constant, high relative surface area, low contact area, low adhesion and coating porosity are envisaged. Applications derived from the above properties include the following: anti-reflective coatings for all kinds of display applications, for biological devices and coatings with improved wetting characteristics; easy to clean and self-cleaning coatings; easy to clean and self-cleaning anti-reflective coatings; non-stick coatings, low dielectric coatings for semi-conductors, low dissipation (low optical loss) coatings for optical wave guides; controlled release coatings, hard membranes, biologically active surfaces, anti-fouling and anti-bacterial coatings.
When it is desirable to have patterned coatings, for example, alternating hydrophobic and hydrophilic regions, this can also be achieved by the process according to the invention, by using photolithographic processes. Hence, applications where patterning of nano-structured and/or nano-porous coatings is desired may also result. This could lead to coatings and articles where the optical or wetting properties are patterned as desired.
In a preferred embodiment the mixture according to the invention comprises an adhesion promoter. An adhesion promoter enhances the adhesion between the coating of the present invention and its substrate. In this way the scratch resistance of the coating is also improved.
The skilled artisan knows how to select a suitable adhesion promoter for given groups at the surface of the reactive nano-particles, reactive diluent and substrate.
Examples of suitable adhesion promoters are compounds having at least one reactive group capable of reacting with the groups at the surface of the reactive nano particles and/or with the reactive diluent and further have at least one reactive group capable of reacting or physically interacting, e.g. H bonding with the substrate.
For glass substrates adhesion promoters can include but are not limited to acrylate, methacrylate or thiol functional trialkoxy silanes, where the trialkoxy groups of the silane can be propoxy or butoxy but is preferably ethoxy or methoxy. Examples of silane adhesion promoters include: γ-mercaptopropylmethylmonomethoxysilane, γ-mercaptopropylmethyidimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmonoethoxysilane, γ-mercaptopropyldiethoxysilane, γ-mercaptopropyltriethoxysilane, β-mercaptoethylmonoethoxysilane, β-mercaptoethyltriethoxysilane, β-mercaptoethyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyidimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxylpropyltrimethoxysilane, γ-glycidoxyl propylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane. Examples of commercially available products of these compounds include SILAACE S310, S311, S320, S321, S330, S510, S520, S530, S610, S620, S710, S810 (manufactured by Chisso Corp.), Siquest A-174NT (manufactured by OSI Specialties—Crompton Corp.). SH6062, AY43-062, SH6020, SZ6023, SZ6030, SH6040, SH6076, SZ6083 (manufactured by Toray-Dow Corning Silicone Co., Ltd.), KBM403, KBM503, KBM602, KBM603, KBM803, KBE903 (manufactured by Shin-Etsu Silicone Co., Ltd.), and the like. Also acidic adhesion promoters such as acrylic acid may be used. Phosphate esters such as Eb168 or Eb170 from UCB are feasible adhesion promoters.
For adhesion to polymeric substrates such as, for example polyethylene terephthalate (PET) and or cellulose triacetate (TAC) the above adhesion promoters may be feasible but also good results are obtained with epoxy functional acrylate or methacrylate compounds.
Surprisingly, it has been found that for substrates containing vinyllic unsaturation, for example acrylate or methacrylate based substrates, like a crosslinked coating, for example a hard coat, compounds comprising at least one thiol group are very suitable as adhesion promoters. Such thiol compounds may be mono-functional, di-functional, preferably tri-functional and most preferably tetra-functional with respect to the number of thiol groups per molecular species. The thiol compounds may comprise next to the thiol group a further reactive group. In case the thiol compound comprises only one thiol group, it must comprise at least one further reactive group. Examples of thiol compounds may be any of those known in the art. A description of the most common thiol compounds may be found at column 9, lines 1-41 of U.S. Pat. No. 3,661,744, which is incorporated herein by reference. Certain polythiols such as the aliphatic monomeric polythiols e.g. ethane dithiol, hexamethylene dithiol, decamethylene dithiol, tolylene-2,4-dithiol, and the like, and some polymeric polythiols such as a thiol-terminated ethylcyclohexyl dimercaptan polymer, and the like, and similar polythiols which are conveniently and ordinarily synthesized on a commercial basis are suitable. Examples of the polythiol compounds preferred because of relatively low odor level include but are not limited to esters of thioglycolic acid (HS—CH2COOH), α-mercaptopropionic acid (HS—CH(CH3)—COOH and β-mercaptopropionic acid (HS—CH2CH2COOH) with polyhydroxy compounds such as glycols, triols, tetraols, pentaols, hexaols, and the like. Specific examples of the preferred polythiols include but are not limited to ethylene glycol bis(thioglycolate), ethylene glycol bis (β-mercaptopropionate), trimethytolpropane tris(thioglycolate), trimethylolpropane tris (β-mercaptopropionate), pentaerythritol tetrakis (β-mercaptopropionate), all of which are commercially available. A specific example of a preferred polymeric polythiol is polypropylene ether glycol bis(β-mercaptopropionate) which is prepared from polypropylene-ether glycol (e.g. Pluracol P201, Wyandotte Chemical Corp.) and β-mercaptopropionic acid by esterfication. Poly-α-mercaptoacetate or poly-β-mercaptopropionate esters, particularly the trimethylopropane triesters or pentaerythritol tetra esters are preferred. Other polythiols which can be suitably employed include alkyl thiol functional compounds such as 1,2-dimercapthoethane, 1,6-dimercaptohexane and the like. Thiol terminated polysulfide resins may also be employed.
Suitable examples of aliphatic dithiols include 1,2-ethanedithiol, butanedithiol, 1,3-propanedithiol, 1,5-pentanedithiol, 2,3-dimercapto-1-propanol, dithioerythritol, 3,6-dioxa-1,8-octanedithiol, 1,8-octanedithiol hexanedithiol, dithiodiglycol, pentanedithiol, decanedithiol, 2-methyl 1,4 butanedithiol, bis-mercaptoethylphenyl methane, 1,9-nonanedithiol(1,9-dimercaptononane), glycol dimercaptoacetate.
Suitable examples of aromatic dithiols include 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, 2,4,6-trimethyl-1,3-benzenedimethanethiol, durene-α1, α2-dithiol, 3,4-dimercaptotoluene, 4-methyl-1,2-benzenedithiol, 2,5-dimercapto-1,3,4-thiadiazole, 4,4′-thiobisbezenedithiol, bis(4-mercaptophenyl)-2,2′-propane(bisphenol dithiol) (made according to the method of Meng Y. Z., Hay. A. S., J. of App. Polym. Sci., V74, 3069-3077(1999).
Suitable examples of oligomeric dithiols include difunctional mercapto functional urethane oiigomers derived from end capping moieties of hydroxyethyl mercaptan, hydroxypropyl mercaptan, dimercaptopropane, dimercapto ethane as described in patent by Shustack U.S. Pat. No. 5,744,514.
Examples of suitable trithiol functional compounds include, trimethylolethane tris-mercaptopropionate, trimethylolpropane tris-mercaptopropionate (TMPTSH), trimethylolethane tris-mercaptoacetate, and trimethylolpropane tris-mercaptoaacetate glycerol tri(11-mercaptoundecanoate), trimethylol propane tri(11-mercaptoundecate). A preferred trithiol is trimethylolpropane tris(2-mercapto-propionate) TMPTSH.
Examples of suitable tetrafunctional thiols include pentaerythritol tetramercapto propionate, pentaerythritol tetramercapto acetate, and pentathritoltetra(11-mercaptoundecate)
Examples of multifunctional thiols having functionality greater than 4, include polythiols as described on page 7 of WO 88/02902.
Multi functional thiols can be obtained by reacting thioalkyl carboxylic acids e.g. thioglycolic acid, mercapto propionic acid with high functional alcohols, amines and thiols. Furthermore, multifunctional thiols can be obtained by reacting mercapto alkyl trialkoxy silanes with silanols that may be polymeric or silica based silanols.
Other preferred multifunctional thiols are obtained using thiol carboxylic acids (HS—R—COOH) where R=alkyl, or aryl groups eg thioundecanoic acid of which the COOH groups are reacted with reactive enes, alcohols, thiols or amines that are multifunctional.
The adhesion promoters may be used in an amount of 0.1-10 wt-% of the total solids in the mixture, after evaporation of the solvent. Preferably the adhesion promoter is used in an amount of 5-10 wt-%.
A further improvement of the scratch resistance is obtained if the mixture according to the invention comprises a compound having a surface energy of less than 25 milli Joules per square meter (mJ/m2). The surface energy is preferably measured of the pure compound according to ASTM D2578, preferably using a ACCU DYNE TEST™ marker pen. An example of such compounds are reactive polydimethylsiloxane compounds. Preferred are reactive fluoro compounds. Reactive fluoro compounds are for example described in U.S. Pat. No. 6,391,459. The fluoro compounds further have the advantage that they don't disturb the anti-reflective properties very much.
Processes for Coating a Substrate to Form an Antireflective Coating
In a further embodiment the substrate is in a first step coated with a first coating. Although the phrase "first coating" is used herein, it will be understood that the first coating may either be applied directly to the substrate or onto one or more layers that have been previously applied to the substrate, such as, by way of example, a high refractive index coating that has been applied onto an existing hard coat layer. The first coating is preferably a cross-linkable material and, still more preferably, a material that can be highly crosslinked to form a hard coat, although it will be understood that materials which are cured or hardened by other methods may be used as well. In a second step, a second coating that alone or in combination with other layers contributes to the creation of antireflective properties (referred to herein as the "antireflective coating") can be applied on top of the first coating. Typically, the second coating is a nano-structured or nano-porous coating of the type described above. However, it will be understood that other coatings which, either alone or in combination with other layers, contribute to the creation of antireflective properties (such as high-refractive index and low-refractive index layers) may also serve as the second coating. In this regard, coatings of the type disclosed in U.S. Pat. Nos. 6,646,080 and 6,686,047, which are incorporated herein by reference and made a part hereof, can be used as a second coating. In this way the first coating acts as a substrate for one or more additional layers. In a preferred embodiment, the first coating preferably comprises vinyllic unsaturations and thiol compounds are preferably used as adhesion promotors. Use of such materials results in still better scratch resistance of the coating of the present invention.
When the first coating is intended to be a hard coat, preferred materials for the first coating are the coatings described in EP-A-1276810, which is incorporated by reference and made a part hereof. Such hard coats are selected in order to optimize the adhesion between the hard coat and the underlying coated or uncoated substrate as well as between the hard coat and the antireflective coating.
In a preferred process for practicing the present invention, during or after the step of applying the first coating, the first coating is partially cured or under-cured, at least on its surface. This means that while the first coating appears to be fully cured, its surface is rendered less resistant to attack by solvents and thus swells (at least partially) during the application of the antireflective coating.
In the event the first coating comprises a radical curing resin system, such as an acrylate-based resin system, such partial curing or under-curing can be effected by utilizing a dose of UV radiation that is insufficient to cause substantially complete cross-linking of the first coating. Alternatively, and preferably, the first coating is cured in the presence of oxygen, for example in an air atmosphere instead of in an inert atmosphere, such as a nitrogen atmosphere. This latter approach inhibits complete cross-linking or curing of the first coating. In this way a still further improved adhesion between the first coating and the second, antireflective coating can be obtained, resulting in a still further improvement of the scratch resistance of the coating according to the present invention.
When the first coating is comprised of a radical curing, acrylate-based resin system, the degree of under-curing can be measured using conventional methods of quantifying reacted acrylate unsaturation (% RAU) well known to those skilled in the art. In this regard, a 95% Relative RAU Dose Test Method can be employed. In this test method, a drop of the desired liquid coating is spin-coated on a KBr crystal until completely covered with the experimental coating at a thickness not exceeding 1.0 micron. The sample is scanned using 100 co-added scans and the spectrum is converted to absorbance. The net peak area of the acrylate absorbance at 810 cm−1 of the liquid coating is then measured.
The net peak area is measured using the "baseline" technique in which a baseline is drawn tangent to absorbance minima on either side of the peak. The area under the peak and above the baseline is then determined.
The sample is exposed to a 100 W mercury lamp (model 6281 from Oriel Corp.) in an air atmosphere. The FTIR scan of the sample and the measurement of net peak absorbance for the spectrum of the cured coating are repeated. Baseline frequencies are not necessarily the same as those of the liquid coating, but are chosen such that the baseline was still tangent to the absorbance minima on either side of the analytical band. The peak area measurement for a non-acrylate reference peak of both the liquid and cured coating spectrum is repeated. For each subsequent analysis of the same formulation, the same reference peak, with the same baseline points, is utilized.
The ratio of the acrylate absorbance to the reference absorbance for the liquid coating is determined using the following equation:
      R    L    =            A      AL              A      RL
where                AAL=area of acrylate absorbance of liquid        ARL=area of reference absorbance of liquid        RL=area ratio of liquidIn a similar manner, the ratio of the acrylate absorbance to the reference absorbance for the cured coating is determined using the equation:
      R    F    =            A      AF              A      RF
where                AAF area of acrylate absorbance of cured coating        ARF area of reference absorbance of cured coating        RF=area ratio of cured coatingThe degree of cure as percent-reacted acrylate unsaturation (% RAU) is calculated using the following equation:
      %                          R                          A                          U    =                    (                              R            L                    -                      R            F                          )            ×      100              R      L
where                RL=area ratio of liquid        RF=area ratio of cured coating
Some compositions containing an appreciable level of multifunctional acrylates are known to have relatively low % RAU values, even when fully cured ("% Ultimate RAU"), usually on the order of 55-70% RAU. For such compositions, "% Relative RAU" represents the degree of curing of a coating composition relative to its % Ultimate RAU, and is defined by the following equation:% Relative RAU=((% RAU of test composition)/(% Ultimate RAU))100
For purposes of the present invention, the undercured first coat is preferably comprised of compositions having appreciable levels of multifunctional acrylates so that % Relative RAU is a useful method of measuring the degree of under-curing or partial cure. For such systems, it is preferred that the % Relative RAU of the under-cured or partially cross-linked first coat be less than about 90%, still more preferably less than about 80%, and most preferably 70% or less. Coatings have such properties are capable of being partially swelled when exposed to the solvent(s) so that good adhesion between this layer and the second layer can be achieved.
In a present method of carrying out the invention, the second coating is carried (for example, dispersed or dissolved) in one or more solvents and the carrying solvent(s) effectuate(s) the swelling of the under-cured first coating. (As used herein, the term "solvent" refers to one solvent or a mixture of a first solvent and one or more co-solvents.) However, it will be understood that the first coating could be pre-treated with one or more solvents in order to effect partial swelling of the first coating prior to application of the second coating.
Another way to establish that the first coating has been properly under-cured so as to obtain the desired improved adhesion and scratch resistance when treated with solvent and the second coating is applied thereto is to perform a solvent double rub test of the surface of the first coating. To conduct this test, a Q-TIP cotton applicator is soaked in a suitable solvent (for example, ethanol or another solvent in which the second coating is carried) and any excess solvent removed by squeezing. With the application of medium pressure (manually), the solvent-moistened Q-TIP applicator is rubbed twice along a test sample consisting of a substrate onto which the first coating or hard coat has been applied. The amount of coating removed by this test should be considerably greater than that removed from a fully cured hard coat, i.e., a hard coat cured at higher dose of radiation and/or under a nitrogen atmosphere, but should not result in substantial or total delamination of the hard coat from the substrate.
As described above, the second, antireflective coating is preferably carried (for example, dissolved or dispersed) in a solvent. When applying the antireflective coating to an under-cured or partially cured first coating, it is helpful to select the carrier solvent(s) in order to maximize the swelling of the first coating. Without being bound by theory, such swelling is believed to improve the adhesion between the hard coat and the antireflective coating. At the same time, it is also desirable to select solvents with relatively low volatility in order to improve the processability and quality of the resultant coatings. A person skilled in the art can select appropriate solvents designed to achieve these objectives based on the composition of the first coating. When the first coating comprises an acrylate-based resin system, solvents that may be employed to swell the first coating include, in addition to the solvents enumerated above, methanol, isopropyl alcohol, methyl isobutyl ketone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate butyl acetate, cyclohexanone, isobutyl isobutyrate, 2-heptanone, cyclopentanone, ethyl acetate, ethanol, acetone, diisobutyl ketone, methyl amyl ketone, n-butanol, isobutanol, sec-butanol, toluene, and xylene used in the amounts described above. 1-Methoxy-2-propanol, methyl isobutyl ketone and methyl ethyl ketone are preferred solvents for optimizing the swelling of acrylate-based coatings.
It has also been discovered that certain application techniques for depositing the second, antireflective coating are to be preferred in practicing the present invention. In particular, when using gravure (roll to roll) coating systems, it is desirable to minimize the gap between the metering or "doctor" blade and the substrate in order to create coatings which are uniform and sufficiently thin. In this regard, it is believed that a smaller gap helps to minimize localized evaporation of solvent, which can result in the metered layer becoming coarse or "grainy", which produces less desirable coatings. As noted above, it will also be understood that a solvents with lower volatility should be utilized in order to minimize such local evaporation.
In the practice of the present invention, the second layer is preferably within the range of 50-150 nm and, still more preferably, in the range of 100-150 nm, still more preferably, in the range of 80-120 nm and, most preferably, about 90 nm. The first layer (for example, the hard coat) is preferably within the range of 3-10 microns and, more preferably, 4-8 microns. These layer thicknesses are also preferred when other application techniques, such as slot die application methods, are employed. It will also be understood that other methods of applying thin coatings, such as vacuum deposition, may also be employed in the practice of the present invention.
Once the second, antireflective coating has been applied to the first coating, it is helpful, although not essential, to heat the antireflective coating while the solvent is being evaporated but prior to, or during, the step of curing the antireflective coating. Heating the antireflective coating in this manner improves the adhesion between the first coating and antireflective coating. It is preferred that the antireflective coating be heated to a temperature in excess of about 50 degrees C. and, more preferably to a temperature within the range of about 60 to about 90 degrees C.
After the second, antireflective coating is applied to the first coating, it is cured by conventional means. In a preferred process for carrying out the present invention, the antireflective coating is itself substantially completely cross-linked by exposing it to UV radiation. It is preferred that the antireflective coating be cured as fully as possible by exposing it to a sufficiently high dose of radiation (e.g. 1-2 Jcm−2 and, preferably, about 1 Jcm−2) to fully crosslink and thus graft it to the previously under-cured and solvent-treated first coating. It is also preferred that the curing be performed in an inert (for example, nitrogen) atmosphere to optimize the cross-linking of the second coating. As noted above, however, when multi-functional acrylates are used, substantially complete cross-linking may mean that only a fraction of the acrylate moieties are cross-linked. In this event, substantially complete cross-linking means that % Relative RAU of the second coating is at least 95% and preferably approaching 100%.
In this regard, the addition of chain transfer agents (such as, by way of example, trimethylol propane and tris(mercapto propionate)) to the second, antireflective coating is a presently preferred method of increasing the amount of cross-linking or cure of the antireflective coating.
When the first and second coatings are comprised of UV-curable resin systems, it has also been discovered that the selection of suitable photo-initiators and synergists can help to optimize the coating process of the present invention. In particular, the first coating preferably contains a type one photo-initiator without a synergist. The second coating or antireflective coating preferably contains a photo-initiator and a synergist, i.e., a molecule with labile hydrogen atom(s). The synergist can either be a molecular entity, such as triethanolamine, or a synergist moiety comprising part of a photo-initiator molecule, such as IRGACURE 907 (available from CIBA Specialty Chemicals), Michlers ketone, or analogues thereof. The second coating preferably includes either a type one or type two photo-initiator (e.g., benzophenone) in addition to the synergist.
Finally, an optional thermal treatment of the coated substrate using, for example, infra-red lights or thermal ovens positioned after the UV curing lights used to cure the second coating is helpful in achieving the optimal balance of optical surface and mechanical properties. Preferably the substrate coated with the first and second coatings is heated within the range of about 60 to about 100 degrees C. and, more preferably, within the range of about 70 to about 90 degrees C. for a period of up to about 5 minutes. Good results are obtained when both the second coating and preferably also the first coating comprise a thermal initiator for subsequent cross-linking during the thermal post-treatment, especially if the cure of first and second coatings has been induced photo-chemically. The skilled artisan knows how to select such a thermal initiator in order to optimize cross-linking.
As an alternative to under-curing a first coating or hard coat, the antireflective coating may be applied directly to a substrate that has been surface treated in order to enhance adhesion between the first and second coatings. Suitable surface treatment methods include corona treatment, as well as flame treatment and treatment with solvents, acids, bases or gas plasma. It is also possible to enhance adhesion between the first coating and the substrate (and, thus, between the first and second coatings) by applying a thin layer of a primer to the substrate before applying the second coating.
It is also possible to produce a film out of the composition according to the invention, and to use the film as a membrane.
It is also possible to use the coating according to the invention in a process of reverse sorption of at least one non-cross-linkable species.

Method of preparing nano-structured surface coatings and coated articles


The portable device is provided with a photograph unit to acquire, at a first time interval, images with a super wide angle of which a maximum value reaches all peripheral directions around the portable device; a traveling direction calculation unit to calculate a traveling direction of the portable device at a second time interval; an image segmentation unit to segment, as a traveling direction image, an image of a predetermined range where the traveling direction is positioned at a center thereof, from a latest acquired image every time the traveling direction calculation unit calculates the traveling direction; and a display control unit to display the traveling direction image on a predetermined traveling direction display region of a display of the portable device. The display control unit displays a video image designated by a user on a first display region, which is different from the traveling direction display region.

The portable device includes a photograph unit and a display unit for displaying a captured image. Using these units, a technique for displaying an image obtained by photographing a traveling direction on the display unit has been known. For example, Patent Literature 1 discloses "a portable device comprising: a photographing means, a direction specifying means for specifying a traveling direction of an own device, a photographing control means for making the photographing means capture a video image of the traveling direction, and a display means for displaying the video image of the traveling direction and an image displayed based on an instruction of a user" (excerpted from Summary).


Methods and systems consistent with the present invention provide a survey tool for allocating costs of a company. A survey is presented to an employee of the company via a network, for example, the Internet. The survey includes a list of activities and asks the employee to rank the activities based on the amount of time spent working on the activities. The survey also prompts the employee to provide information including average hours worked per week, job position, etc. A server receives the employee's responses and, using company information stored by the server, allocates costs of the company.

A. Field of the Invention
The present invention relates to methods for allocating costs of a company. More particularly, the present invention relates to methods for allocating activity-based costs of a company using information provided by employees of the company.
B. Description of the Related Art
In today's marketplace, companies of all types strive to reduce costs while improving customer service. For example, insurance companies work to improve service to policyholders while reducing the costs associated with processing insurance claims. Insurance companies may also wish to reduce the time required to process claims or improve overall operating efficiency. To achieve its goals, a company can employ many business tools.
One such tool is an employee survey. A company can survey its employees to evaluate the company's performance. By understanding how employees spend their time, the company can determine the costs associated with specific tasks or activities performed by the employees. The company can use these cost determinations to develop and evaluate future plans for the company. For example, an insurance company could survey its claims handlers to determine the cost of processing a certain claim type.
To conduct an employee survey, a company can administer the survey itself or hire an outside firm to develop and administer the survey. Either way, a survey must be created and presented to the employees, and the employees' responses must be recorded and tallied. This can be done by distributing a paper survey to some or all of the employees, who complete and return the survey. Alternatively, designated survey-takers could sit down with each employee, read the questions to the employee, and record the employee's answers on the survey.
The utility of the survey results depends on the survey questions and the accuracy of employee responses. If the survey is too brief or worded poorly, the results may not be detailed enough to provide meaningful feedback to the company. Similarly, if taking the survey is difficult or time-consuming, it is likely that employees will give rushed or incomplete responses. It is therefore desirable to develop a method that provides flexibility in creating a survey and a user-friendly mechanism for administering the survey.

Method for evaluating activity-based costs of a company


An agricultural baler including a base unit, a plurality of ground engaging devices and a transmission. The plurality of ground engaging devices support the base unit. The transmission is mounted on the base unit. The transmission includes an input shaft and an other shaft. The other shaft is separate from the input shaft. The other shaft is drivingly coupled to the input shaft. The other shaft is connected to a flywheel and/or a hydraulic pump. The other shaft is configured to operate at a different speed than the speed at which the input shaft operates.

A cut and raked crop that has been dried or otherwise prepared in a field, such as hay, straw or other agricultural material is often gathered, compressed and shaped by an agricultural baler. There are several types of balers that are commonly used, each resulting in different types of bales. Some are rectangular and some are cylindrical of various sizes. Bales can be bound with netting, strapping, wire or traditionally twine. A baler that produces small rectangular bales, often called square bales, often produce bales that are typically wrapped with two strands of knotted twine. The bales are light enough for easy handling and typically weigh from 40 to 80 pounds. A bale is formed by a series of processes performed by the square baler including lifting the windrowed material, hereinafter referred to as hay, by way of the pickup portion of the baler. The hay is then moved by way of an auger into a chamber that has a feeding fork. The feeding fork moves the hay in front of a sliding plunger with a cutting edge that cuts the hay and moves the hay in the chamber into previously packed hay therein causing the hay to be compressed. Once a predetermined amount of hay has been gathered in the chamber, as measured by the amount being extruded through the opening at the rear of the chamber, a mechanism is triggered causing the twine to be threaded through the hay, cut and then knotted thereby forming the bale and one portion of the twine is retained to start to receive hay for the next bale. As the bales are moved through the compression channel out to the rear of the baler, the baled hay is then either loaded onto a wagon or dropped into the field for later retrieval.
The plunger mechanism of the square baler requires a considerable amount of energy to cut and compress the hay. Typically the mass of the plunger is augmented by a flywheel connected so that energy from the tractor during the non-compressing part of the stroke is stored in the flywheel and then is expended as the plunger compresses the hay. Some older balers including some currently being used by the Amish have a gasoline engine mounted thereon with a belt drive directly driving the flywheel of the baler. Typically balers have the flywheel oriented towards the front of the baler with the PTO shaft from the tractor directly driving the flywheel that is then interconnected to the plunger.
Another type of baler in common use today is one that produces large rectangular bales. These larger rectangular bales are many times larger than the smaller bales previously discussed. The baling concept is similar in that the hay is picked up and then compressed in a chamber and extruded from the back of the baler once the desired size is reached and the twine is secured around the bale. The large rectangular balers require even more energy and a larger flywheel to provide the sustained energy requirement during the compression portion of the plunger stroke.
The problem with the larger energy requirement of larger balers is that a large flywheel is required to even out the power demands of the baler. Another problem with the prior art is that in light crop conditions or uneven terrain where forward travel speed is limited causes the prior art balers to compact a portion of the bale several times before gathering enough material to introduce to the compression chamber for compacting by the plunger. This causes a portion of the hay in the bale to be recompacted causing undue damage to the hay as it is mechanically impacted, compressed and relaxed with each stroke.
What is needed in the art is a baler that alters the plunger drive speed and reduces the need for a large flywheel.

Drive arrangement for powering the plunger of an agricultural baler


An infant sling carrier has a carrier panel terminating in a tail portion extending from one end. A pair of buckle rings is attached to the carrier panel at the opposite end and functions in concert with the tail portion to provide a sling of adjustable length for carrying an infant. The free end of the tail portion is provided with a safety stop member which can be maneuvered through the buckle rings when creating the sling, but which has a long dimension which will not pass through the buckle rings if the tail portion accidentally releases and slides through the buckle rings.

This invention relates to infant carriers in general. More particularly, this invention relates to infant sling-type carriers.
Infant sling-type carriers are known which are used to facilitate the care and handling of an infant from birth up until an age at which the infant weighs approximately 30 pounds. Such carrier-type slings are typically fabricated from a flexible fabric and comprise a carrier panel terminating at one end in a tail portion, which serves as a sling tie. A pair of buckle rings is secured to the other end of the carrier panel and the rings' function in concert with the tail portion to secure the ends of the panel together in an adjustable fashion to provide the sling. The sling is formed by passing the tail portion through both of the buckle rings and doubling the tail portion back over one ring and under the other in a conventional fashion. This arrangement provides a friction tie serving to retain the tail portion in the buckle rings. To enhance the friction tie, the buckle rings may be provided with serrations along the inner diameter thereof in order to increase the frictional force holding the tail portion in the rings. One popular model of infant sling carrier includes padded side rails extending from end to end of the carrier panel, and a pillow portion secured to the carrier panel adjacent the end bearing the buckle rings, to provide additional comfort to the infant and the person wearing the sling.
While infant carrier slings of the above type have been found to be very effective and convenient for carrying infants, problems have been encountered on occasion with the friction tie afforded by the buckle rings and tail portion. In particular, on occasion the tail portion accidentally slips through the buckle rings, thereby undoing the sling. Such an occurrence is, at best, undesirable, and may be dangerous to the infant.


A semiconductor package includes a first interconnect substrate on a first redistribution substrate and having a first opening penetrating the first interconnect substrate. A first semiconductor chip is on the first redistribution substrate and the first opening of the first interconnect substrate. A second redistribution substrate is on the first interconnect substrate and the first semiconductor chip. A second interconnect substrate is on the second redistribution substrate and has a second opening penetrating the second interconnect substrate. A second semiconductor chip is on the second redistribution substrate and in the second opening of the second interconnect substrate.

A semiconductor package is provided to implement an integrated circuit chip for use in electronic products. In one type of semiconductor package, a semiconductor chip is mounted on a printed circuit board, and bonding wires or bumps are used to electrically connect the semiconductor chip to the printed circuit board.
Attempts are continually being made to reduce the size, weight, and cost of manufacturing semiconductor packages. The sizes of semiconductor chips in the packages may be made smaller as integration increases. However, it may be difficult to adhere, handle, and/or test solder balls of a semiconductor chip of reduced size. Additionally, there are problems of acquiring a diversified mount board in accordance with the size of the semiconductor chip.

Semiconductor package having a plurality of chips and method of manufacturing the same


A process of grinding a surface of a workpiece, by a grinding tool rotated about its axis. The process includes a grinding step of grinding the workpiece surface, by pressing at least one of the grinding tool and the workpiece against the other of the grinding tool and the workpiece, such that a constant force is exerted on the other of the grinding tool and the workpiece by the at least one of the grinding tool and the workpiece. Also disclosed is a grinding apparatus including: a moving device operable to move at least one of the grinding tool and the workpiece relative to the other of the grinding tool and the workpiece, at least in an infeed direction that increases a depth of cut of the grinding tool into the workpiece; and a controller which controls the moving device, such that the at least one of the grinding tool and the workpiece is pressed against the other of the grinding tool and the workpiece, with a constant force.

1. Field of the Invention
The present invention relates in general to a grinding process and a grinding apparatus for producing and finishing a surface of a workpiece with a high accuracy.
2. Discussion of Related Art
There is known, as a kind of grinding apparatus, a rotary-type vertical spindle surface grinder including: a work rotating device operable to rotate a workpiece about its axis parallel to a vertical direction; a grinding-tool rotating device operable to rotate the grinding tool about its axis parallel to the vertical direction for grinding a surface of the workpiece; a supporting device which supports the grinding-tool rotating device such that the grinding-tool rotating device is movable in a direction parallel to the axis of the grinding tool; and a grinding-tool moving device operable to move the grinding tool toward the workpiece in the direction parallel to the axis of the grinding tool. As an example of the rotary-type vertical spindle surface grinder, JP-H08-276349A (publication of unexamined Japanese Patent Application laid open in 1996) discloses a surface grinder in which a feed movement of the grinding tool or workpiece is controllable with accuracy in order of submicrons or nanomicrons.
In the rotary-type vertical spindle surface grinder disclosed in the publication of the Japanese Patent Application, a position of the grinding tool (grinding wheel) is constantly detected, and the detected position of the grinding tool is input to a controller, so that a hydraulic cylinder as the grinding-tool moving device is controlled by the controller, on the basis of the detected position of the grinding tool. That is, the disclosed grinder is equipped with a feedback control system in which the hydraulic cylinder is controlled in a closed-loop manner, whereby the workpiece can be grounded accurately by a desired amount of depth of cut of the grinding tool into the workpiece.
Like in the above-described disclosed grinder, in a conventional rotary-type vertical spindle surface grinder, it is common that the grinding tool is moved at a constant feed rate in an infeed direction (that increases the depth of cut) until the workpiece has a desired dimension or depth of cut. In such a machining method, the grinding tool is moved in the infeed direction to increase the depth of cut until the workpiece is given the desired dimension, irrespective of a grinding load which acts on the grinding tool and which is represented by a pressing force or a drive current. Therefore, a machining operation according to the conventional method can not be necessarily carried out with a sufficiently high efficiency, and can not necessarily provide a sufficiently high quality of the machined workpiece. For example, in the conventional machining operation which is carried out at a constant feed rate such that the workpiece has a desired dimension, the grinding tool could be forcedly moved at a constant feed rate in the infeed direction even in event of reduction in a grinding capacity of the tool due to clogging of its grinding surface, thereby causing glazing on the grinding surface of the tool and consequently making impossible to provide a satisfactory quality of the machined workpiece. The glazing on the grinding surface might be avoided by reducing the feed rate or reducing an amount of stock removal per a unit of time. However, such a reduction causes the workpiece to be ground with an insufficient pressing force, namely, with a low machining efficiency.

Grinding process and apparatus with arrangement for grinding with constant grinding load


Systems and methods for improving results of wafer higher order shape (HOS) characterization and wafer classification are disclosed. The systems and methods in accordance with the present disclosure are based on localized shapes. A wafer map is partitioned into a plurality of measurement sites to improve the completeness of wafer shape representation. Various site based HOS metric values may be calculated for wafer characterization and/or classification purposes, and may also be utilized as control input for a downstream application. In addition, polar grid partitioning schemes are provided. Such polar grid partitioning schemes may be utilized to partition a wafer surface into measurement sites having uniform site areas while providing good wafer edge region coverage.

Thin polished plates such as silicon wafers and the like are a very important part of modern technology. A wafer, for instance, may refer to a thin slice of semiconductor material used in the fabrication of integrated circuits and other devices. Other examples of thin polished plates may include magnetic disc substrates, gauge blocks and the like. While the technique described here refers mainly to wafers, it is to be understood that the technique also is applicable to other types of polished plates as well. The term wafer and the term thin polished plate may be used interchangeably in the present disclosure.
Generally, certain requirements may be established for the flatness and thickness uniformity of the wafers. The semiconductor industry uses the two global wafer shape metrics, bow and warp, to describe the overall wafer shape. Global surface fitting using the Zernike polynomials or Taylor polynomials have also been used to describe the wafer shape components.
However, the two global wafer shape metrics, bow and warp, do not have the required spatial resolution and sensitivity for the local wafer shape characterization. Methods based on the whole wafer surface fitting cannot provide the information about the location of wafer local higher order shape components and often do not have good shape sensitivity even with very high polynomial fitting orders.
Therein lies a need for systems, methods and metrics for wafer high order shape characterization and wafer classification without the aforementioned shortcomings.

Systems, methods and metrics for wafer high order shape characterization and wafer classification using wafer dimensional geometry tool


A circuit and method for cochlear implant telemetry where digital data is encoded into an RF signal. The RF signal is applied via a rectifier diode to a first switch matrix S1 and a second switch matrix S2, with S1 being coupled to a first sampling capacitor C1 and S2 being coupled to a second sampling capacitor C2. A local oscillator signal with period T is applied that controls S1 and S2, cyclically coupling C1 and C2 to the RF signal, a first input to a comparator, and ground. The comparator compares the first input to a DC reference voltage. The output of the comparator is then sampled via a flip flop clocked by the local oscillator, with the flip flop outputting a data bit stream representative of the envelope of the RF signal having encoded information.

Cochlear implants (inner ear prostheses) are a means to help profoundly deaf or severely hearing impaired persons. Unlike conventional hearing aids, which just apply an amplified and modified sound signal, a cochlear implant is based on direct electrical stimulation of the acoustic nerve. The intention of a cochlear implant is to stimulate nervous structures in the inner ear electrically in such a way that hearing impressions most similar to normal hearing are obtained.
A cochlear prosthesis essentially consists of two parts, the speech processor and the implanted stimulator. The speech processor contains the power supply (batteries) of the overall system and is used to perform signal processing of the acoustic signal to extract the stimulation parameters. The stimulator (implant) generates the stimulation patterns and conducts them to the nervous tissue by means of an electrode array which usually is positioned in the scala tympani in the inner ear. The connection between the speech processor and the implanted receiver can be established by means of encoding digital information in an rf-channel involving an inductively coupled coils system.
Decoding the information within the implant can require envelope detection. Envelope detection of an RF signal within an implant is usually performed with a simple circuit, as shown in FIG. 1, composed of a rectifier diode 4, an RC-network 1 and 2, and a comparator 7. A drawback to this circuit is that the total power consumption of the RC-network, due in part to the ohmic resistor, can be considerable when taking into account the cochlear implant application.
Stimulation strategies employing high-rate pulsatile stimuli in multi-channel electrode arrays have proved to be successful in giving very high levels of speech recognition. One example therefore is the so-called "Continuous Interleaved Sampling (CIS)"—strategy, as described by Wilson B. S., Finley C. C., Lawson D. T., Wolford R. D., Eddington D. K., Rabinowitz W. M., "Better speech recognition with cochlear implants," Nature, vol. 352:236–238 (1991), which is incorporated herein by reference. For CIS, symmetrical biphasic current pulses are used, which are strictly non-overlapping in time. The rate per channel typically is higher than 800 pulses/sec
Stimulation strategies based on simultaneous activation of electrode currents so far have not shown any advantage as compared to CIS. The basic problem is the spatial channel interaction caused by conductive tissue in the scala tympani between the stimulation electrodes. If two or more stimulation current sources are activated simultaneously, and if there is no correlation between them, the currents will flow between the active electrodes and do not reach the regions of neurons which are intended to be stimulated. The problem might get less severe with new stimulation electrode designs, where the electrodes are much closer to the modiolus as compared to existing electrodes, as described by Kuzma J., "Evaluation of new modiolus-hugging electrode concepts in a transparent model of the cochlea," proc. 4th European Symp. on Pediatric Cochlear Implantation, 's-Hertogenbosch, The Netherlands (June 1998), which is incorporated herein by reference.
For high-rate pulsatile stimulation strategies, some patient specific parameters have to be determined. This is done some weeks after surgery in a so called "fitting"-procedure. For given phase duration of stimulation pulses and for given stimulation rate, two key parameters have to be determined for each stimulation channel:                1. the minimum amplitude of biphasic current pulses necessary to elicit a hearing sensation (Threshold Level, or THL); and        2. the amplitude resulting in a hearing sensation at a comfortable level (Most Comfort Level, or MCL).
For stimulation, only amplitudes between MCL and THL (for each channel) are used. The dynamic range between MCL and THL typically is between 6–12 dB. However, the absolute positions of MCLs and THLs vary considerably between patients, and differences can reach up to 40 dB. To cover these absolute variations, the overall dynamic range for stimulation in currently used implants typically is about 60 dB.
At the moment, MCLs and THLs are estimated during the fitting procedure by applying stimulation pulses and asking the patient about his/her subjective impression. This method usually works without problems with postlingually deaf patients. However, problems occur with prelingually or congenitally deaf patients, and in this group all ages—from small children to adults—are concerned. These patients are usually neither able to interpret nor to describe hearing impressions, and only rough estimations of MCLs and THLs based on behavioral methods are possible. Especially the situation of congenitally deaf small children needs to be mentioned here. An adequate acoustic input is extremely important for the infant's speech and hearing development, and this input in many cases can be provided with a properly fitted cochlear implant.
One approach for an objective measurement of MCLs and THLs is based on the measurement of the EAPs (Electrically evoked Action Potentials), as described by Gantz B., Brown C. J., Abbas P. J., "Intraoperative Measures of Electrically Evoked Auditory Nerve Compound Action Potentials," American Journal of Otology 15 (2):137–144 (1994), which is incorporated herein by reference. In this approach, the overall response of the acoustic nerve to an electrical stimulus is measured very close to the position of nerve excitation. This neural response is caused by the superposition of single neural responses at the outside of the axon membranes. The amplitude of the EAP at the measurement position is between 10 μV and 1000 μV. Information about MCL and THL at a particular electrode position can first of all be expected from the so called "amplitude growth function," as described by Brown C. J., Abbas P. J., Borland J., Bertschy M. R., "Electrically evoked whole nerve action potentials in Ineraid cochlear implant users: responses to different stimulating electrode configurations and comparison to psychophysical responses," Journal of Speech and Hearing Research, vol. 39:453–467 (June 1996), which is incorporated herein by reference. This function is the relation between the amplitude of the stimulation pulse and the peak-to-peak voltage of the EAP. Another interesting relation is the so called "recovery function". Here, stimulation is achieved with two pulses with varying interpulse-interval. The recovery function as the relation of the amplitude of the 2nd EAP and the interpulse-interval allows one to draw conclusions about the refractory properties and particular properties concerning the time resolution of the acoustic nerve.

Multichannel cochlear implant with neural response telemetry


A camera installed in a wireless terminal comprises a first electronic zooming means to operate by hardware and a second electronic zooming means to operate by software. The first electronic zooming means quickly select one of several pictures with predetermined scale factor. The second electronic zooming means zoom in or out a picture in small steps. An operator can quickly display a picture of desired scale factor by these two means. Further, in a foldable type terminal with a magnetic sensor, a picture with desired scale factor can be displayed by adjusting an angle between a first housing and a second housing.

1. Field of the Invention
The invention relates to a wireless terminal comprising a camera, more particularly, the wireless terminal that can quickly display a zoomed picture with a desired scale factor.
2. Description of the Related Prior Art
In late years cellular telephones with a camera spread rapidly. This camera comprises electronic zoom function rather than optical zoom function, because a housing of the cellular telephone has to be made thin as possible. Japanese Patent Laid-Open No. 2002-077698 bulletin discloses an example of a method to zoom in or zoom out a picture by means of an electronic zooming.
In an electronic zooming method, there are a method carried out by software and a method carried out by hardware. The electronic zooming method carried out by hardware performs cutout and pixel skipping of a picture. The method enables to form a picture with a normal scale factor and pictures with some fixed scale factors. However, a picture of an arbitrary scale factor cannot be formed. An operator, therefore, must change distance between a camera and an object to get a picture with a desired scale factor. The electronic zooming method carried out by software enables smooth zooming in small steps. However, as the number of the pixels of the picture increases, time to need for zooming increases. Particularly, it becomes difficult to display a picture with a desired scale factor when speed of zooming rises.

Wireless terminal comprising a camera and having fine and coarse electronic zooming functions


An adapter assembly comprises a cable ferrule that terminates environmental and strength members of a high count fiber optic cable while allowing a plurality of optical fibers to pass therethrough. A flange on the cable ferrule mates with a corresponding groove of a breakout body. A breakout body cover is provided to enclose an open longitudinal channel of the breakout body. Flexible jacketing may be coupled to an end of the breakout body with a traversing plurality of optic fiber encased in the flexible jacketing. In another aspect of the present invention, a modular connector assembly is provided that may be configured in both a pulling configuration (for installation of the cable assembly) and a connector configuration (for termination of the optical fibers). In this manner, relatively inflexible high count fiber optic cables may be transitioned into more flexible configurations for subsequent termination in a relatively inexpensive manner.

High count fiber optic cables are well known in the art. For example, a typical outdoor cable may comprise several dozen fiber optic ribbons, each ribbon typically comprising up to twelve individual optical fibers, in a single cable. Such cables are particularly useful for communication equipment that terminates a large number of optical fibers, such as, for example, routers or switches used in a large-scale communication network. It is not unusual for multiple pieces of such communication equipment to be located in different buildings, thereby requiring connections between buildings. To this end, high count, outdoor fiber optic cables are typically used to connect such communication equipment together.
Given the environment in which they must perform, as well as the large number of fibers carried within, high count outdoor fiber optic cables typically include several structural strengthening members (e.g., plastic or metal wires or jackets capable of withstanding the tensional or pulling forces that may be applied to the cable) as well as several environmental protection layers (e.g., water-proof insulating layers). While the resulting cable is well suited for the environment in which it operates, the structural and environmental enhancements provided in outdoor cable make it relatively stiff. The stiffness of the outdoor cable, as a consequence, makes it difficult to work with when attempting to terminate the outdoor cable, and its constituent optical fibers, at the communication equipment.
Prior art solutions to the problems of terminating outdoor cables, while workable, have proven less than satisfactory. For example, when transitioning from outdoor cable to indoor connections, a typical solution is to use one or more splice boxes having outdoor cable on one side and indoor fiber optic cable and connectors/adapters on the other. While this solution is serviceable, it requires additional work for mounting and deploying the splice boxes and it is therefore relatively expensive to implement. Consequently, it would be advantageous to provide relatively inexpensive means for transitioning from outdoor fiber optic cables to more flexible, indoor cables that may be subsequently routed and terminated at the equipment of interest.

Breakout and connector assemblies for use with high count fiber optic cables