Abstract: A method for producing a polytetrafluoroethylene particle, which includes subjecting tetrafluoroethylene to suspension polymerization in an aqueous medium to prepare a suspension-polymerized particle of polytetrafluoroethylene, washing and then crushing the suspension-polymerized particle or crushing the suspension-polymerized particle with washing to prepare a crushed particle, dehydrating the crushed particle to prepare a crushed particle having a water content of 40% by mass or less, and subjecting the dehydrated crushed particle to heat treatment to produce a polytetrafluoroethylene particle.

Abstract: A method for producing a polytetrafluoroethylene powder, which includes subjecting tetrafluoroethylene to suspension polymerization in an aqueous medium to prepare a suspension-polymerized particle of non melt-processible polytetrafluoroethylene, drying the suspension-polymerized particle to prepare a dry particle, subjecting the dry particle to fluorine radical treatment to prepare a fluorine radical-treated particle, and crushing the fluorine radical-treated particle to produce a polytetrafluoroethylene powder. Also disclosed is a polytetrafluoroethylene formed article obtained by forming the polytetrafluoroethylene powder, as well as a polytetrafluoroethylene compression-molded article obtained by compression molding the polytetrafluoroethylene powder.

Abstract: The semiconductor element has an electrode including: a Ni-inclusion metal layer containing nickel formed on a side of at least one surface of the semiconductor-element constituting part; a Ni-barrier metal layer formed outwardly on a side of the Ni-inclusion metal layer opposite to the side toward the semiconductor-element constituting part; and a surface metal layer outwardly formed on a side of the Ni-barrier metal layer opposite to the side toward the semiconductor-element constituting part, to be connected to the metal nanoparticles sintered layer; wherein the Ni-barrier metal layer contains a metal for suppressing diffusion of nickel toward the surface metal layer.

Abstract: A semiconductor device includes a circuit substrate which is configured with an insulative substrate formed of a ceramic material and provided on its one surface with an electrode formed of a copper material, and a power semiconductor element bonded with the electrode using a sinterable silver-particle bonding material, wherein the electrode has a Vickers hardness of 70 HV or more in its portion from the bonding face with the power semiconductor element toward the insulative substrate to a depth of 50 ?m, and has a Vickers hardness of 50 HV or less in its portion at the side toward the insulative substrate.