Abstract: A conductive polycrystalline diamond film having specific resistance of at least 1×10−4 &OHgr;cm and less than 1×103 &OHgr;cm, whose film thickness is in the range of at least 0.1 &mgr;m and not more than 500 &mgr;m, is film-formed by vapor-phase synthesis on a surface employed for pressure bonding, a surface opposite to this surface or at least two side surfaces intersecting with these surfaces on a substrate of a bonding tool tip that is applicable for bonding and packaging a semiconductor chip.

Abstract: An electron-emitting element comprises a diamond substrate, and a diamond protrusion grown on a surface of the diamond substrate so as to have a pointed portion in a form capable of emitting an electron. Since the diamond protrusion formed by growth has a sharply pointed tip portion, it can fully emit electrons. Preferably, the surface of the diamond substrate is a {100} face, and the diamond protrusion is surrounded by {111} faces.

Abstract: An electron-emitting element comprises a diamond substrate, and a diamond protrusion grown on a surface of the diamond substrate so as to have a pointed portion in a form capable of emitting an electron. Since the diamond protrusion formed by growth has a sharply pointed tip portion, it can fully emit electrons. Preferably, the surface of the diamond substrate is a {100} face, and the diamond protrusion is surrounded by {111} faces.

Abstract: Provided is a thermal transfer recording medium which can be transferred well even onto a medium to be transferred such as a durable plastic film. The printed matters can obtain all together sufficiently high mechanical abrasion resistance, solvent resistance against various solvents and light fastness against rays such as UV rays. The above thermal transfer recording medium comprises at least a support and a thermal transfer ink layer provided on the support, wherein the thermal transfer ink layer contains a colorant and a vinyl chloride base copolymer obtained by copolymerizing three components of 50 to 90% by weight of vinyl chloride, 5 to 20% by weight of vinyl acetate and 10 to 30% by weight of hydroxyacrylate each based on the whole amount of the monomers.

Abstract: An object of the invention is to provide a window for an optical use having excellent transmission property over a wide range of from infra-red to vacuum ultraviolet as well as excellent baking resistance and capable of being fitted to an ultra-high vacuum apparatus and a process for the production of the same.This object can be attained by a window for an optical use comprising a diamond as a window material, a flange for a vacuum apparatus, a frame for bonding the diamond to the flange and the specified adhesive material for bonding the frame and diamond, and a process for the production of the window for an optical use comprising a step of preparing a diamond plate, a step of fitting a frame to a flange and bonding the diamond plate to the frame through an adhesive material. The benefits can be enlarged by suitably selecting the shape, material, etc. of the frame.

Abstract: An initial single-crystalline diamond base material is prepared from a flat plate having a major surface and side surfaces consisting of low-index planes. Then, single crystalline diamond is homoepitaxially vapor-deposited on the single-crystalline diamond base material, and a resulting diamond material is cut and polished in a particular manner to provide a successive base material on which single-crystalline diamond is again grown, thereby forming a single-crystalline diamond having a large area. A holder for the single-crystalline diamond base material consists of or is coated with a material hardly forming a compound with carbon. Single crystalline diamond can be stably formed on the surfaces of the base material. Consequently, single-crystalline diamond of high quality having a large area can be stably produced in a shorter time using either plasma CVD or a thermal filament method.

Abstract: A diamond polycrystal body having metal films on its upper and lower surfaces is cut in the vertical direction using a laser to form a diamond polycrystal body piece having upper and lower surfaces and a cut surface connecting the upper and lower surfaces. The cut surface may be damaged and include graphite resulting from the laser cutting. To remove the damage and the graphite, the cut surface of the diamond polycrystal body piece is then plasma-treated. Thereby a prescribed degree of electrical insulation between the metallized upper and lower surfaces can be ensured.

Abstract: In a method of synthesizing diamond on a substrate from plasma containing a carbon component, filaments containing tungsten as a thermoelectron-emitting material are arranged above a substrate in a chamber. An electrode is provided at a position separated from and particularly above the filaments. The filaments are at least temporarily energized with a potential relatively higher than that of the substrate, while the electrode is at least temporarily supplied with a potential relatively higher than that of the filaments. Thus, plasma is generated between the filaments and the substrate, while electrons are moved from the filaments to the electrode for also generating plasma between the filaments and the electrode, thereby forming nuclei of diamond on the substrate. Thereafter, the respective potentials of the electron emitting filaments and the electrode are equalized with each other, for growing a film of diamond from the nuclei of diamond.

Abstract: It is an object to provide a thermal-transfer recording medium and its thermal-transfer recording method whereby it is possible to perform good thermal transfer to a durable transfer medium such as plastic film etc., and the transferred image is excellent in resistance to mechanical abrasion, and whereby color reproducibility is excellent when plural colors of thermal transferred inks are printed in layers. A thermal-transfer ink layer is provided which at least presents the visco-elastic characteristics that tan.delta. is of 1 or more and the complex dynamic viscosity falls within 100 to 40,000 Pa.s in the viscoelasticity measurement with a frequency of 1 Hz in the linear viscoelastic region of temperature from 100 to 150.degree. C. Alternatively, a thermal-transfer ink layer containing a coloring matter and a thermo-fusing resin is provided on a support, and the thermo-fusing resin presents the visco-elastic characteristics that tan.delta. is of 1.

Abstract: A tool comprising a blank and shank, bonded at a low temperature through a bonding layer of gold formed by thermocompression bonding between the blank and shank is provided which can be used at a high temperature independently of the temperature at which the blank and shank were bonded.

Abstract: A method for bonding a cubic boron nitride sintered compact to other cubic boron nitride sintered compact or to a body of shank material is disclosed. The method comprises forming a Ti layer of 0.01-1 .mu.m in thickness over a bonding interface between two cubic boron nitride sintered compacts or between a cubic boron nitride sintered compact and a body of shank material, forming a layer of Ni or Cu over the Ti layer to a thickness of 0.01-5 .mu.n, putting together the two cubic boron nitride sintered compacts or the cubic boron nitride sintered compact and the body of shank material with a 10-1,000 .mu.m foil of Al, Al-Ni alloy or Ag--Cu--In alloy being placed over the boding interface, and heating the cubic boron nitride sintered compact structure to temperatures above the meeting point of the metal foil and not exceeding 750.degree. C. in an inert atmosphere or in a vacuum.

Abstract: Herein is disclosed a high hardness sintered diamond compact and a process for the production of the same.The high hardness sintered diamond compact comprises 80 to 95% by volume of diamond particles, 0.5 to 5% by volume of a carbide particles selected from a group consisting of WC and (Mo,W)C and having a diameter not larger than 1 micron, and 4.5 to 15% by volume of an iron group metal, at least 95% by volume of said diamond particles having a diameter from 0.1 to 2 micron and the remainder of the diamond particles being particles having a diameter smaller than 0.1 micron.The ratio by volume of the amount of the diamond particles having a diameter from 1 to 2 micron to that of the diamond particles having a diameter from 0.1 to 1 micron ranges from 4 to 1.The high hardness sintered diamond compact according to the present invention is preferably usable as a drawing die for drawing a high hardness plated-steel wire and as a tool bit.