GB2363615A - Composite material with epitaxial carbon fibres in a metal matrix - Google Patents
Composite material with epitaxial carbon fibres in a metal matrix Download PDFInfo
- Publication number
- GB2363615A GB2363615A GB0120163A GB0120163A GB2363615A GB 2363615 A GB2363615 A GB 2363615A GB 0120163 A GB0120163 A GB 0120163A GB 0120163 A GB0120163 A GB 0120163A GB 2363615 A GB2363615 A GB 2363615A
- Authority
- GB
- United Kingdom
- Prior art keywords
- composite material
- carbon fibers
- vapor
- phase
- metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D19/00—Casting in, on, or around objects which form part of the product
- B22D19/14—Casting in, on, or around objects which form part of the product the objects being filamentary or particulate in form
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
- C04B41/50—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials
- C04B41/51—Metallising, e.g. infiltration of sintered ceramic preforms with molten metal
- C04B41/515—Other specific metals
- C04B41/5155—Aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C49/00—Alloys containing metallic or non-metallic fibres or filaments
- C22C49/14—Alloys containing metallic or non-metallic fibres or filaments characterised by the fibres or filaments
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
- C30B25/005—Growth of whiskers or needles
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/02—Elements
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
- H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
- H01L23/373—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
- H01L23/3733—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon having a heterogeneous or anisotropic structure, e.g. powder or fibres in a matrix, wire mesh, porous structures
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/0001—Technical content checked by a classifier
- H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Ceramic Engineering (AREA)
- Metallurgy (AREA)
- Structural Engineering (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Manufacture Of Alloys Or Alloy Compounds (AREA)
Abstract
A composite material comprises vapour-phase epitaxial carbon fibres in a metal matrix. The fibres may have a feather-like structure. The metal may be aluminium or an aluminium alloy and the composite material may be used as a heat sink. It may be made by dispersing the fibres in a solvent, removing the solvent to form a fibre layer, placing the fibre layer overlaid by metal and a filter in a pressure container, applying a vacuum to the container and heating the metal so that it melts and impregnates the fibre layer.
Description
2363615 COMPOSITE MATERIAL AND MANUFACTURING METHOD THEREFOR The present
invention relates to a technique about a composite material incorporating a matrix which is metal and fillers which are vapor-phase-epitaxial carbon fibers.
Aluminum or an aluminum alloy which is excellent in heat conductivity is employed to manufacture a heat sink or the like to locally cool and radiate heat from a CPU or the like.
The size of notebook-type apparatuses and hand-held apparatuses each of which cannot be provided with a radiating fan has been reduced Thus, a variety of apparatuses having considerably reduced weights have successively been developed.
Moreover, increase in the number of clocks (the operation frequency) results in enlargement of the quantity of generated heat from the apparatus.
To meet the contradictory requirements, a material having a reduced weight and excellent heat conductivity has been required.
An object of the present invention is to improve the foregoing problem experienced with the conventional technique, that is, to provide a composite material having a considerably reduced weight and excellent heat conductivity.
To solve the foregoing problem, a composite material according to the present invention is a composite material comprising:
vapor-phase-epitaxial carbon fibers; and metal.
A method of manufacturing a composite material according to the present invention is a method of manufacturing a composite material comprising the steps of: dispersing vapor-phase-epitaxial carbon fibers in solvent and shifting the solution into a container; removing the solvent to form a fiber layer constituted by the vapor-phase-epitaxial carbon fibers; placing, in a pressure container, the fiber layer, a filter and metal; producing vacuum in the pressure container; and heating and melting the metal so that the fiber layer is impregnated with the molten metal through application of pressure.
Fig 1 is a photograph of vapor-phase-epitaxial carbon fibers which are feather-like fibers taken by a scanning electron microscope.
Fig 2 is another photograph of the vapor-phase-epitaxial carbon fibers which are feather-like fibers taken by a scanning electron microscope.
Fig 3 is a photograph of a preferred vapor-phase-epitaxial carbon fibers which are feather-like fibers taken by a transmission electron microscope.
Fig 4 is a diagram showing an example of a method of manufacturing a composite material according to the present invention, in which Fig 4 (a) is a diagram (amodel diagram) showing a state where slurry obtained by dispersing the vapor-phase- epitaxial carbon fibers which are the feather-like fibers in solvent is shifted into a container, Fig 4 (b) is a diagram (a model diagram) showing a state where a fiber layer constituted by the vapor-phase-epitaxial carbon fibers which are the feather- like fibers has been formed in the container shown in Fig 4 (a), Fig 4 (c) is a model cross sectional view showing a state where the fiber layer is impregnated with molten metal and Fig 4 (d) is a diagram (a model diagram) showing the composite material (the composite material incorporating the vapor-phase-epitaxial carbon fibers which are the feather-like fibers and metal).
Fig 5 is a diagram (a model diagram) showing the composite material incorporating woven fabric constituted by long carbon fibers as fillers.
The composite material according to the present invention is a vapor growth carbon fibers (hereinafter also called as "VGCF") exhibiting excellent heat conductivity Therefore, the composite material exhibiting excellent heat conductivity can be obtained.
The vapor-phase-epitaxial carbon fibers for use in the composite material according to the present invention include known needle crystal called a "whisker" The foregoing needle crystal has a one-dimensional shape When the needle crystal is employed to mold a composite material for use to meet a three-dimensional purpose, for example, heat radiation, the direction of orientation of the needle crystal must be controlled The control is, however, very difficult.
Polyacrylonitrile carbon fibers and pitch carbon fibers, which are long carbon fibers, are known as one-dimensional carbon fibers When the foregoing long carbon fibers are chopped or milled (when the long carbon fibers are milled by a usual method, complete powder cannot be obtained and, therefore, the fiber shape is maintained), a similar problem in terms of the shape arises The heat conductivity of the long carbon fibers is considerably lower than that of the vapor-phase-epitaxial carbon fibers (the heat conductivity of the vapor-phase-epitaxial carbon fibers is about 1500 w/m K, while that of the PAN or pitch carbon fibers is about 1 w/m K to about 600 w/m K) Therefore, if a composite material with aluminum (having a heat conductivity of 200 w/m K to 270 w/m K) is prepared, the heat conductivity cannot satisfactorily be raised.
The conventional composite material (see Fig 5) including woven fabric constituted by long carbon fibers has a structure that the fibers are oriented two-dimensionally Also the heat conductivity of the foregoing composite material has directional properties Therefore, satisfactory one-dimensional or two- dimensional heat conductivity can be obtained However, satisfactory three-dimensional heat conductivity cannot be obtained Although so-called 3 D woven fabric (stereoscopically woven fabric) may be employed, a high filling density with which a satisfactory effect can be obtained cannot be realized What is worse, the foregoing woven fabric is a costly fabric from a viewpoint of practical use.
Therefore, the vapor-phase-epitaxial carbon fibers for use in the composite material according to the present invention must be vapor-phase-epitaxial carbon fibers which are the feather-like fibers The vapor-phase-epitaxial carbon fibers which are the feather-like fibers have a specific gravity of about 2 0 (the specific gravity of aluminum is 2 7) Moreover, the vapor- phase-epitaxial carbon fibers of the foregoing type have branches (ramification) and partially include bending and, in some cases, restrictions In addition, the fibbers are twined themselves or mutually so that a fiber block having an undefined shape and an overall size of 0 03 mm to 1 mm is formed The vapor-phase- epitaxial carbon fibers which are the feather-like fibers have branches Therefore, heat can be conducted through a three- dimensional network Hence it follows that a composite material excellent in three-dimensional heat conductivity can be obtained when the foregoing vapor-phase-epitaxial carbon fibers are employed as fillers Figs 1 and 2 show photographs of the vapor-phase-epitaxial carbon fibers which are feather-like fibers having bending, sometimes restrictions and twined themselves or mutually taken by a scanning electron microscope Fig 3 shows the same taken by a transmission electron microscope.
The vapor-phase-epitaxial carbon fibers which are the feather-like fibers are obtained by performing a vapor phase epitaxial process performed such that hydrocarbon, such as benzene, serves as a carbon source and iron is used as a core under the presence of hydrogen At this time, conditions, such as the temperature, the atmospheric pressure and the quantity of supply of hydrocarbon which is the raw material, are changed Thus, the vapor-phase-epitaxial carbon fibers can be obtained which are the feather-like fibers having branches (ramification) and partially including bending and, in some cases, restrictions and twined themselves or mutually The plural feather-like fibers are mutually twined so that a fiber block is formed Hitherto, the vapor-phase-epitaxial carbon fibers have been manufactured under conditions which do not form branches and bending for the purpose of using the vapor-phase-epitaxial carbon fibers in a usual purpose, for example, obtaining satisfactory mechanical strength.
It is preferable that metal serving as the matrix in the composite material according to the present invention has high heat conductivity and a low specific gravity from a viewpoint of the spirit of the present invention That is, it is preferable that any one of aluminum, a variety of aluminum alloys and magnesium alloys is employed.
The composite material according to the present invention can be obtained, for example, as follows.
The vapor-phase-epitaxial carbon fibers which are the feather-like fibers are delicate and brittle fibers which can easily be broken owing to exertion of stress Thus, the three-dimensional network can easily be lost Therefore, the vapor-phase-epitaxial carbon fibers are dispersed in organic solvent (as an alternative to this, mixed solvent may be employed), such as water, alcohol or ketone (the foregoing solvent is collectively called,solventt) If necessary, a chemical, such as a surface active agent, for improving the dispersing characteristic isaddedtoformthesolution intoslurryl O 101 Then, the slurry 101 is injected into a container made of a porous material 102 (filter paper or porous ceramic) and having a bottom which permits penetration of liquid (see Fig 4 (a)) Then, the solvent is removed so that the fiber layer 103 constituted by the vapor-phase-epitaxial carbon fibers which are the feather-like fibers as shown in Fig 4 (b) is formed.
The obtained fiber layer is shifted into a container 1 (a pressure container) provided with a heater 104 as shown in Fig.
4 (c) The bottom (a "base material" in the drawing) portion 106 can be removed as described later.
A filter 105 constituted by a porous material (which is porous ceramics in this embodiment) having heat resistance is laminated on the foregoing fiber layer 103 Then, metal (in the solid form) is laminated on the filter 105.
After the fiber layer 103, the filter 105 and the metal 106 have been placed in the pressure container, vacuum is produced in the pressure container Moreover, the heater 104 provided for the container is operated to heat and melt the metal 106 Moreover, pressure is applied to the inside portion of the container 1 by using a gas which is inactive with respect to the molten metal which is the matrix and carbon or argon gas (the argon gas is used in this embodiment) Thus, the fiber layer 103 is, through the application of pressure, impregnated with molten metal serving as the matrix component Then, the operation of the heater 104 of the container 1 is interrupted to cool the system and solidify metal.
After the temperature has been decreased, the base material in the bottom of the container is removed Thus, the composite material incorporating the vapor-phase-epitaxial carbon fibers which are the feather-like fibers is extracted.
As described above, impregnation of molten metal is performed under pressure of the inactive gas Thus, an excellent composite material can be obtained even if the molten metal which can easily be oxidized is used.
The filter is able to vertically move in the pressure container to maintain an optimum space below the filter Therefore, excessive enlargement of the quantity of the matrix component in the obtained composite material can be prevented Moreover, breakage of the vapor-phase-epitaxial carbon fibers which are the feather-like fibers can substantially completely be prevented.
Hence it follows that the heat conductivity and an effect of reducing the weight of the vapor-phase-epitaxial carbon fillers which are the feather-like fibers can satisfactorily be improved.
When the shape of each of the base material and the porous ceramics is changed, a variety of shapes may be realized, for example, a shape suitable for a heat sink Therefore, a post-process for realizing the shape can be omitted or the foregoing post-process can be facilitated.
The foregoing method of manufacturing the composite material enables FRM (fiber-reinforced metal) which cannot easily be manufactured and in which the specific gravity of the matrix is higher than that of the filler to easily be obtained The obtained composite material exhibits excellent dispersion of the filler, the material being capable of preventing dispersion of various performance (the heat conducting characteristic, the conductivity, the strength and the elasticity) and reducing the orientation.
Note that also the method of manufacturing the composite material according to the present invention may be applied when a composite material incorporating a filler which is constituted by a usual vapor-phase-epitaxial carbon fibers as well as the vapor- phase-epitaxial carbon fibers which are the feather-like fibers.
The composite material according to the present invention is light in weight and exhibits excellent heat conductivity because of no directional properties Since the carbon fibers which are feather-like fibers are used as the fillers, the composite material also exhibits excellent mechanical strength.
The method of manufacturing the composite material enables the composite material (the fiber-reinforced metal) to be obtained which exhibits excellent dispersion of the fillers, which is capable of preventing scattering of the performance and with which directional properties can be reduced.
Claims (2)
1 A composite material comprising:
vapor-phase-epitaxial carbon fibers; and a metal.
2 A method of manufacturing a composite material comprising the steps of:
dispersing vapor-phase-epitaxial carbon fibers in solvent; removing said solvent to form a fiber layer defined by said vapor-phase-epitaxial carbon fibers; placing, in a pressure container, said fiber layer, a filter and metal; producing vacuum in said pressure container; and heating and melting said metal so that said fiber layer is impregnated with the molten metal through application of pressure.
-11
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP27927299A JP2001107203A (en) | 1999-09-30 | 1999-09-30 | Composite material and its production method |
GB0022593A GB2354775B (en) | 1999-09-30 | 2000-09-14 | Composite material and manufacturing method therefor |
Publications (3)
Publication Number | Publication Date |
---|---|
GB0120163D0 GB0120163D0 (en) | 2001-10-10 |
GB2363615A true GB2363615A (en) | 2002-01-02 |
GB2363615B GB2363615B (en) | 2002-05-29 |
Family
ID=26245002
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB0120163A Expired - Fee Related GB2363615B (en) | 1999-09-30 | 2000-09-14 | Composite material and manufacturing method therefor |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2363615B (en) |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH02212370A (en) * | 1988-09-02 | 1990-08-23 | Nikkiso Co Ltd | Composite material |
JPH02296776A (en) * | 1989-05-12 | 1990-12-07 | Riken Corp | Composite ceramic sintered body containing vapor-grown carbon fiber |
JPH03174312A (en) * | 1989-11-30 | 1991-07-29 | Nkk Corp | Metallic particle-containing carbon fiber sheet and its production |
JPH03268853A (en) * | 1990-03-20 | 1991-11-29 | Furukawa Electric Co Ltd:The | Manufacture of composite material |
EP0583062A1 (en) * | 1992-07-06 | 1994-02-16 | Nikkiso Co., Ltd. | Graphitized carbon fibers |
US5814408A (en) * | 1996-01-31 | 1998-09-29 | Applied Sciences, Inc. | Aluminum matrix composite and method for making same |
-
2000
- 2000-09-14 GB GB0120163A patent/GB2363615B/en not_active Expired - Fee Related
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH02212370A (en) * | 1988-09-02 | 1990-08-23 | Nikkiso Co Ltd | Composite material |
JPH02296776A (en) * | 1989-05-12 | 1990-12-07 | Riken Corp | Composite ceramic sintered body containing vapor-grown carbon fiber |
JPH03174312A (en) * | 1989-11-30 | 1991-07-29 | Nkk Corp | Metallic particle-containing carbon fiber sheet and its production |
JPH03268853A (en) * | 1990-03-20 | 1991-11-29 | Furukawa Electric Co Ltd:The | Manufacture of composite material |
EP0583062A1 (en) * | 1992-07-06 | 1994-02-16 | Nikkiso Co., Ltd. | Graphitized carbon fibers |
US5814408A (en) * | 1996-01-31 | 1998-09-29 | Applied Sciences, Inc. | Aluminum matrix composite and method for making same |
Also Published As
Publication number | Publication date |
---|---|
GB2363615B (en) | 2002-05-29 |
GB0120163D0 (en) | 2001-10-10 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP1696046B1 (en) | Process for producing a metal-based carbon fiber composite material | |
US5586152A (en) | Carbon fiber-reinforced carbon composite materials, processes for their production, and first walls of nuclear fusion reactors employing them | |
US5814408A (en) | Aluminum matrix composite and method for making same | |
US7563502B2 (en) | Fine carbon fiber-metal composite material and method for production thereof | |
EP2123800B1 (en) | Crucible holding member and method for producing the same | |
CN110079693A (en) | The method for preparing metal-base composites blank based on 3D printing technique | |
EP2098619A1 (en) | Crucible holding member and method for producing the same | |
US20100163782A1 (en) | Carbon-Containing Metal-Based Composite Material and Manufacturing Method Thereof | |
US6406790B1 (en) | Composite material and manufacturing method therefor | |
WO2000027776A1 (en) | Carbon-based metal composite material, method for preparation thereof and use thereof | |
JP3673436B2 (en) | Carbon-based metal composite material and manufacturing method thereof | |
CN102149843A (en) | Method for making a part made of a composite material with a metal matrix | |
US20090211518A1 (en) | Crucible holding member and method for producing the same | |
EP2135976A2 (en) | Crucible holding member and method for producing the same | |
EP2098618B1 (en) | Container holding member and method for producing the same | |
Pippel et al. | Interlayer structure of carbon fibre reinforced aluminium wires | |
CN107326307B (en) | Ultrasonic vibration prepares the method that stratiform intersects Carbon Fibre Reinforced Metal Matrix Composites | |
CN109686501A (en) | A kind of graphene/aluminum composite conducting material and preparation method thereof | |
GB2363615A (en) | Composite material with epitaxial carbon fibres in a metal matrix | |
JP4053729B2 (en) | Composite material and manufacturing method thereof | |
CN116693311A (en) | Preparation and application of high-heat-conductivity matrix and coating integrated design and ablation-resistant composite material | |
CN109942297A (en) | A kind of silicon carbide nanometer line enhances highly oriented graphite composite material and preparation method | |
JP2002059257A (en) | Composite material | |
JP6799451B2 (en) | Method for manufacturing SiC fiber / SiC composite material | |
JP2004285372A (en) | Copper-carbon fiber composite material, production method therefor, and semiconductor device using the same |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20070914 |