39results about How to "Excellent electromagnetic wave shielding" patented technology

A resin composition for semiconductor encapsulation having goodmoldability, of which the cured product has effective electromagnetic wave shieldability, is provided. A resin composition for semiconductor encapsulation, containing spherical sintered ferrite particles having the following properties (a) to (c) : (a) the soluble ion content of the particles is at most 5 ppm; (b) the mean particle size of the particles is from 10 to 50 [mu]m; (c) the crystal structure of the particles by X-ray diffractiometry is a spinel structure.

The invention relates to acid solution used for processing the magnesium alloy surface. The acid solution is water solution which contains acids, inhibitor and wetting agent, wherein, the acids are first acids or mixture of first acids and second acids; the first acids are selected from one type or a plurality of types among citric acids, oxalic acids, tartaric acids, methanoic acids, acetic acids, metacetonic acids, butyric acids, glutaric acids, phenylformic acids, benzene dicarboxylic acids, lactic acids, glycolic acids, glyoxylic acids and amino acids; and the second acids are hydrochloricacids and / or nitric acids. By adoption of the acid solution, the magnesium alloy surface can be fully activated; the membranous layer of a converting film which is formed on the magnesium alloy surface after chemical conversion process is compact, has erosion resistance and good binding force with a paint film. Moreover, the method is a environment-friendly method for processing the magnesium alloy surface.

Provided is a flexible electromagnetic wave shielding material. An electromagnetic wave shielding material, according to one embodiment of the present invention, comprises: a conductive fiber web comprising a plurality of pores; and a heat dissipation part provided in at least some of the pores. Due to these features, as the electromagnetic wave shielding material according to the present invention has excellent flexibility, elasticity, and creasing / recovery, it is possible to freely modify the shape thereof as desired and to attach the electromagnetic wave shielding material to be completelyadhered to a surface even if the surface where the material is to be disposed has a curved shape such as uneven or stepped surfaces, and thus it is possible to exhibit excellent electromagnetic wave shielding performance. Also, degradation of the electromagnetic wave shielding performance can be prevented even with various shape changes. Further, since heat dissipation performance is excellent, heat generated in an electromagnetic wave generating source can be rapidly conducted and radiated. In addition, even when parts are mounted with a high density in a narrow area, the electromagnetic waveshielding material can be provided to completely adhere to the mounted parts while overcoming the tight spacing intervals and steps between the parts, such that the flexible electromagnetic wave shielding material can easily be adopted in a compact or flexible electronic device.

The present invention provides a flexible electromagnetic wave shielding material. An electromagnetic wave shielding material, according to one embodiment of the present invention, comprises: a conductive fiber web including conductive composite fibers comprising a metal shell part coated on the outside of a fiber part to form a plurality of pores; and a first conductive component provided in at least some of the pores. Due to these features, as the electromagnetic wave shielding material has excellent elasticity, and creasing / recovery, it is possible to freely modify the shape thereof as desired and to attach the electromagnetic wave shielding material to be completely adhered to a surface even if the surface where the material is to be disposed has a curved shape such as uneven or stepped surfaces, and thus it is possible to exhibit excellent electromagnetic wave shielding performance. In addition, degradation of the electromagnetic wave shielding performance can be prevented even with various shape changes. Furthermore, even when parts are mounted with a high density in a narrow area, the electromagnetic wave shielding material can be provided to completely adhere to the mountedparts while overcoming tight spacing intervals and steps between the parts, such that the flexible electromagnetic wave shielding material can easily be adopted in a compact or flexible electronic device.

A flame-retardant and electromagnetic interference attenuating thermoplastic resin composition excellent in flame retardance, surface appearance and processability in molding, which comprises 100 parts by weight of a thermoplastic resin (A), 0.5 to 30 parts by weight of a halogen-free phosphate flame retardant (B) represented by the general formula (1), 5 to 35 parts by weight of a metal-coated fiber (C), and 3 to 30 parts by weight of a flaky or needle-like filler (D):(1) wherein R1, R2, R3 and R4 are each independently hydrogen or a monovalent organic group, with the proviso that at least one of R1, R2, R3 and R4 is a monovalent organic group; X is a divalent organic group; k, l, m and n are each independently 0 or 1; and N is an integer of 0 to 10.

The invention discloses a preparation method of a polyaniline / carbon nano tube compound electromagnetic shielding material. The preparation method comprises the following steps: (a) carboxylation of carbon nano tubes: adding concentrated H2SO4 into a mixture of carbon nano tubes and NaNO3 at low temperature, evenly stirring, raising the temperature, adding KMnO4, finally adding an H2O2 solution, and carrying out post-processing so as to obtain the carboxylated carbon nano tubes; and (b) preparation of the polyaniline / carbon nano tube compound shielding material. The surface of the polyaniline / carbon nano tube compound electromagnetic shielding material prepared by the method is composed of burr-shaped polyaniline nano fibers with rough surfaces. The polyaniline / carbon nano tube compound material has a large electromagnetic wave reflection section, thus the electromagnetic wave shielding property can be effectively improved; and the material has good electromagnetic shielding property in a microwave frequency band of 8-12 GHz, and can be used as a good electromagnetic shielding material.

A magnesium-plastic composite board is disclosed and used for architectural decoration. The magnesium-plastic composite board is formed by continuous hot pressing of a magnesium alloy panel (1) with the outer surface coated with an organic coating, a back aluminum alloy bottom plate (5), polymer adhesive films (2) (4) and a middle plastic core material (3). The magnesium-plastic composite board integrates decoration and functions, and is a decorative and functional material integrates characteristics of light weight, high specific strength and rigidity, corrosion resistance, impact resistance,sag resistance, vibration resistance, noise reduction and electromagnetic shielding functions. The magnesium-plastic composite board is suitable for the fields of manufacture of partition walls for aircrafts and ships, manufacture of light train cases, electromagnetic shielding engineering and architectural decoration.

A flexible electromagnetic wave shielding material is provided. The electromagnetic wave shielding material according to one embodiment of the present invention comprises: a conductive nanofiber web having a nanofiber web formed of nanofibers and including a plurality of pores and a metal layer covering a part of the nanofibers disposed on a surface portion of the nanofiber web, in which metal particles are provided on at least a part of the pores; and an elastic member bonded to one surface of the metal layer of the conductive nanofiber web. Due to these features, as the electromagnetic waveshielding material has excellent elasticity, it is possible to freely modify the shape thereof as desired and to attach the electromagnetic wave shielding material to be completely adhered to a surface even if the surface where it is disposed has a curved shape such as uneven or stepped surfaces, and thus it is possible to exhibit excellent electromagnetic wave shielding performance. Further, degradation of the electromagnetic wave shielding performance can be prevented even with various shape changes. Furthermore, even when components are mounted with a high density in a narrow area, the electromagnetic wave shielding material can be provided to completely adhere to the mounted components by overcoming tight spacing and steps between the components, such that the electromagnetic wave shielding material can be easily adopted in compact or flexible electronic devices.

A metal-coated fabric having excellent electromagnetic-wave-shielding properties. The metal-coated fabric has, on at least one side thereof, a layer made of a flame retardant composition prepared without using any halogenated compound or antimony compound.

The invention discloses a black coloring process of a stainless steel precision screen mesh, and the black coloring process comprises the following step of: sequentially carrying out cleaning, activating and blackening processing on the weaved stainless steel precision screen mesh in the presence of a sealed container, wherein the blackening processing is as follows: spraying a vaporous blackening agent to a tensioning stainless steel precision screen mesh, applying voltage on the tensioning stainless steel precision screen mesh, so that the potential difference of the tensioning stainless steel precision screen mesh and the sprayed vaporous blackening agent is formed and arc discharge is generated, reacting the stainless steel wire of the stainless steel precision screen mesh with the blackening agent, and forming an ultrathin blackening layer on the surface of the stainless steel wire.The blackening layer obtained on the surface of the stainless steel precision screen mesh has the advantages of uniformity, densification and good adhesive force and cannot generate interference on the aperture of the stainless steel precision screen mesh by being extremely thin; and the black coloring process disclosed by the invention has the advantages of simplicity and fast deposition of the blackening layer, meets the requirement for environmental protection as the blackening agent does not contain the elements, such as selenium, phosphorus, chromium, and the like which pollute the environment, is nontoxic and can be directly discharged, and is lower in preparation cost.

The invention discloses an electronic information card provided with a tungsten alloy shield plate. The electronic information card comprises an electronic information card substrate and the tungsten alloy shield plate arranged in the electronic information card substrate; the electronic information card substrate comprises a chip and / or a magnetic strip; the tungsten alloy shield plate comprises the following components in mass percentage: 30%-98% of tungsten, 1.23%-40% of nickel, 0.53%-27% of copper, 0.24%-3% of cobalt and 0.1%-1.0% of rare earth. The invention further discloses the tungsten alloy shield plate. According to the tungsten alloy shield plate and the electronic information card provided with the same, the tungsten alloy shield plate with an excellent radiation-proof property is arranged in the electronic information card, so that information in the electronic information card can be prevented from being read or interfered.

The invention relates to an electromagnetic wave shielding coating method, as a method for electromagnetic wave shielding coating on the surface of metal or non-metallic materials, which includes: a pretreatment step, cleaning the surface of the material, and performing a dry method before coating surface etching; a surface seed crystal replacement molding step, forming a metal seed layer on the pretreated surface; a first gold plating step, using the first metal to perform electroless gold plating on the surface of the seed layer to realize the basic shielding function; and the second The second gold plating step is to use the second metal to carry out electroless gold plating on the surface of the first metal gold-plated layer to realize the final shielding function. The above-mentioned first metal is copper, and the above-mentioned second metal is tungsten. The electromagnetic wave shielding coating method provided by the present invention It can be applied to the surface of components of smart cars, mobile devices, and wearable devices. It has excellent electromagnetic wave shielding effect, coating durability, shortens production time, and is excellent in terms of cost efficiency.

Provided is a method for performing an electromagnetic interference shielding coating operation on the surface of a metal or a nonmetal material, comprising: a pre-process step of cleaning the surfaceof the material and performing a dry surface etching operation before coating; a surface seed replacement forming step of forming a metal seed layer on the pre-processed surface; a first plating stepof performing an electroless plating operation on a surface of the seed layer by a first metal having a basic shielding function; and a second plating step of performing an electroless plating operation on a surface of the first metal plating layer by a second metal having a finishing shielding function, wherein the first metal is copper (Cu) and the second metal is tungsten (W). The present invention provides the electromagnetic interference shielding coating method which can be applied to the surface of components of a smart car, a mobile device and a wearable device, and has excellence inan electromagnetic interference shielding effect, coating durability, manufacturing time and economic feasibility for costs.

The invention resin coating metal plate with resin involucra on the surface of the metal plate, which can raise the conductivity of the resin coating metal plate, and has excellent electromagnetic interference shielding capacity, preferably under gently contacting. The said resin involucra satisfies the necessary condition of the following formula (1): PPIt>=70 ellipsis (1). The PPIt denotes thenumber of peak-valley when 1 / 2 of the peak count level (2H) is used as the thickness t(mu m) of resin involucra in PPI(Peaks Per Inch) recorded in SAE J911-1986.