Abstract: A low-cost spinel sintered body having small polarization and high heat-conductivity is provided. Also, a useful light-transmitting window and light-transmitting lens for light-emitting device is provided. For such purpose, the spinel sintered body of the present invention has a contrast ratio of 300 or more in the case of white light, where the contrast ratio is defined as the quotient obtained by dividing an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being parallel to each other, by an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being orthogonal to each other.

Abstract: A low-cost spinel sintered body having small polarization and high heat-conductivity is provided. Also, a useful light-transmitting window and light-transmitting lens for light-emitting device is provided. For such purpose, the spinel sintered body of the present invention has a contrast ratio of 300 or more in the case of white light, where the contrast ratio is defined as the quotient obtained by dividing an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being parallel to each other, by an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being orthogonal to each other.

Abstract: A low-cost spinel sintered body having small polarization and high heat-conductivity is provided. Also, a useful light-transmitting window and light-transmitting lens for light-emitting device is provided. For such purpose, the spinel sintered body of the present invention has a contrast ratio of 300 or more in the case of white light, where the contrast ratio is defined as the quotient obtained by dividing an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being parallel to each other, by an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being orthogonal to each other.

Abstract: A low-cost spinel sintered body having small polarization and high heat-conductivity is provided. Also, a useful light-transmitting window and light-transmitting lens for light-emitting device is provided. For such purpose, the spinel sintered body of the present invention has a contrast ratio of 300 or more in the case of white light, where the contrast ratio is defined as the quotient obtained by dividing an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being parallel to each other, by an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being orthogonal to each other.

Abstract: In a semiconductor heat-dissipating substrate made of a Cu—W alloy whose pores have been infiltrated with copper, being a porous tungsten body whose pore diameter at a specific cumulative surface area of 95% is 0.3 ?m or more, and whose pore diameter at a specific cumulative surface area of 5% is 30 ?m or less, thermal conductivity of 210 W/m·K or more is obtained by decreasing the content of iron-family metal to be less than 0.02 weight %. Likewise, changing the amount of infiltrated copper in a molded object by utilizing a multi-shaft press to vary the amount of vesicles in the middle and peripheral portions makes for offering at low cost a semiconductor heat-dissipating substrate that in between middle and peripheral portions made of different materials does not have bonding matter.

Abstract: In a semiconductor heat-dissipating substrate made of a Cu—W alloys whose pores have been infiltrated with copper, being a porous tungsten body whose pore diameter at a specific cumulative surface area of 95% is 0.3 ?m or more, and whose pore diameter at a specific cumulative surface area of 5% is 30 ?m or less, thermal conductivity of 210 W/m·K or more is obtained by decreasing the content of iron-family metal to be less than 0.02 weight %. Likewise, changing the amount of infiltrated copper in a molded object by utilizing a multi-shaft press to vary the amount of vesicles in the middle and peripheral portions makes for offering at low cost a semiconductor heat-dissipating substrate that in between middle and peripheral portions made of different materials does not have bonding matter.

Abstract: In a semiconductor heat-dissipating substrate made of a Cu—W alloy whose pores have been infiltrated with copper, being a porous tungsten body whose pore diameter at a specific cumulative surface area of 95% is 0.3 ?m or more, and whose pore diameter at a specific cumulative surface area of 5% is 30 ?m or less, thermal conductivity of 210 W/m·K or more is obtained by decreasing the content of iron-family metal to be less than 0.02 weight %. Likewise, changing the amount of infiltrated copper in a molded object by utilizing a multi-shaft press to vary the amount of vesicles in the middle and peripheral portions makes for offering at low cost a semiconductor heat-dissipating substrate that in between middle and peripheral portions made of different materials does not have bonding matter.

Abstract: A highly reliable member for a semiconductor device, in which a high melting point metallizing layer, which consists mainly of a high melting point metal such as W and/or Mo, and an intervening metal layer, which has a melting point of not greater than 1,000° C. and consists mainly of at least one selected from among Ni, Cu and Fe, are provided on an AlN substrate material in this order on the AlN substrate material, and a conductor layer consisting mainly of copper is directly bonded to the intervening metal layer without intervention of a solder material layer. A semiconductor element or the like is mounted on the member for a semiconductor device, thereby fabricating a semiconductor device. The high melting point metallizing layer is formed on an aluminum nitride substrate by post-fire or co-fire metallization.

Abstract: In a semiconductor heat-dissipating substrate made of a Cu—W alloy whose pores have been infiltrated with copper, being a porous tungsten body whose pore diameter at a specific cumulative surface area of 95% is 0.3 &mgr;m or more, and whose pore diameter at a specific cumulative surface area of 5% is 30 &mgr;m or less, thermal conductivity of 210 W/m·K or more is obtained by decreasing the content of iron-family metal to be less than 0.02 weight %. Likewise, changing the amount of infiltrated copper in a molded object by utilizing a multi-shaft press to vary the amount of vesicles in the middle and peripheral portions makes for offering at low cost a semiconductor heat-dissipating substrate that in between middle and peripheral portions made of different materials does not have bonding matter.

Abstract: A highly reliable member for a semiconductor device, in which a high melting point metallizing layer, which consists mainly of a high melting point metal such as W and/or Mo, and an intervening metal layer, which has a melting point of not greater than 1,000° C. and consists mainly of at least one selected from among Ni, Cu and Fe, are provided on an AlN substrate material in this order on the AlN substrate material, and a conductor layer consisting mainly of copper is directly bonded to the intervening metal layer without intervention of a solder material layer. A semiconductor element or the like is mounted on the member for a semiconductor device, thereby fabricating a semiconductor device. The high melting point metallizing layer is formed on an aluminum nitride substrate by post-fire or co-fire matallization.

Abstract: A highly reliable member for a semiconductor device, in which a high melting point metallizing layer, which consists mainly of a high melting point metal such as W and/or Mo, and an intervening metal layer, which has a melting point of not greater than 1,000.degree. C. and consists mainly of at least one selected from among Ni, Cu and Fe, are provided on an AlN substrate material in this order on the AlN substrate material, and a conductor layer consisting mainly of copper is directly bonded to the intervening metal layer without intervention of a solder material layer. A semiconductor element or the like is mounted on the member for a semiconductor device, thereby fabricating a semiconductor device. The high melting point metallizing layer is formed on an aluminum nitride substrate by post-fire or co-fire matallization.

Abstract: An aluminum nitride sintered body has a metallized layer on its surface. The metallized layer contains tungsten, aluminum oxide and calcium oxide. Preferably, the metallized layer contains 40 to 96 percent by weight of a metal, 0.4 to 25 percent by weight of an aluminum oxide and 3 to 35 percent by weight of calcium oxide. In a method of forming a metallized layer on the surface of the aluminum nitride sintered body, such body is first formed by firing. Then, a metal paste of tungsten containing powder of calcium oxide and powder of aluminum oxide is provided. The metal paste is coated on the surface of the aluminum nitride sintered body which is then fired with the metal paste in an inert atmosphere.

Abstract: An aluminum nitride sintered body that has been fired/formed to have a prescribed sintered configuration, is used as a substrate. A metal paste of tungsten is prepared and applied to the substrate. The metal paste of tungsten contains oxide components of at least 1 percent by weight of the paste and not more than 40 percent by weight of the paste. The oxide components include SiO.sub.2 of at least 1 percent by weight of the oxide components and not more than 40 percent by weight of the oxide components. The oxide components include CaO and Al.sub.2 O.sub.3 in a weight ratio of at least 0.5 and not more than 2 of CaO to Al.sub.2 O.sub.3. The aluminum nitride sintered body coated with the metal paste is heated/fired in a non-oxidizing atmosphere at a temperature of at least 1400.degree. C. and not more than 2000.degree. C.

Abstract: Disclosed herein is a method of making a surface structure on a ceramic substrate capable of suppressing diffusion of Ni to an Au plating layer and of reducing the necessary thickness of the Au plating layer. A metallized layer (12), Ni layer (13) and Au layer (14) are formed in this order on a surface of a ceramic substrate (11). The substrate (11) is heated in a non-oxidizing atmosphere to cause an alloying reaction between the Ni layer (13) and the Au layer (14). Thereafter, an Au plating layer (16) is formed on the NiAu alloy layer (15). Since Ni in the NiAu alloy layer is not easily released, diffusion of Ni into the Au plating layer can be suppressed sufficiently. Therefore, the Au plating layer can be small in thickness, generally less than 1 micron.

Abstract: A ceramic substrate has a surface structure capable of suppressing diffusion of Ni into an Au plating layer by providing an NiAu alloy layer between the substrate and the Au plating layer, whereby the thickness of the Au plating layer may be reduced. Such a surface structure is formed by applying the following layers to the substrate, a metallized layer (12), Ni an layer (13) and Au layer (14) in this order. The substrate (11) is heated in a non-oxidizing atmosphere to cause an alloying reaction between the Ni layer (13) and the Au layer (14). Thereafter, an Au plating layer (16) is formed on the NiAu alloy layer (15). Since Ni in the NiAu alloy layer is not easily released, diffusion of Ni into the Au plating layer is suppressed sufficiently.

Abstract: An aluminum nitride sintered body is mainly composed of aluminum nitride, contains 0.01 to 1.0 percent by weight of a rare earth element and 0.001 to 0.5 percent by weight of oxygen, and has thermal conductivity of at least 180 W/mK. According to a method of manufacturing such an aluminum nitride sintered body, aluminum nitride powder (201) is first prepared. At least one compound (203) containing a rare earth element is added to the aluminum nitride powder (201) to contain 0.01 to 1.0 percent by weight, in rare earth element conversion, of the compound, to be homogeneously mixed with each other. A formed body obtained by forming such mixed powder is sintered in a non-oxidizing atmosphere containing nitrogen at a temperature of 1500 to 2200.degree. C.

Abstract: An aluminum nitride sintered body mainly composed of aluminum nitride, contains 0.01 to 1.0 percent by weight of a rare earth element and 0.001 to 0.5 percent by weight of oxygen. Such a body has a thermal conductivity of at least 180 W/mK. For manufacturing such an aluminum nitride sintered body, aluminum nitride powder (201) is first prepared. At least one compound (203) containing a rare earth element is added to the aluminum nitride powder (201) to contain 0.01 to 1.0 percent by weight, in rare earth element conversion, of the compound. The ingredients are homogeneously mixed with each other. A green body is formed of the mixed powder and sintered at a temperature of 1500.degree. to 2200.degree. C. in a non-oxidizing atmosphere containing nitrogen.

Abstract: A connection structure between lead frames and a base plate of aluminum nitride, to be applied as a connection structure between components of a semiconductor apparatus, has a base plate made of a sintered body of aluminum nitride on which a semiconductor device is to be mounted. The lead frames are made of iron alloy containing nickel in 29 wt. % and cobalt in 17 wt. %. A silver solder is used for joining the base plate and the lead frames. A surface of the lead frame to be joined to the base plate is clad with a stress relief layer of oxygen-free copper of a high plastic deformability to relieve, by its plastic deformation, a thermal stress caused by a difference between a thermal expansion coefficient of the aluminum nitride base plate and that of the lead frame in a cooling process at the time of soldering. Preferably, only a portion of each lead frame to be joined to the base plate comprises an inner layer of an iron alloy containing 29 wt. % of nickel and 17 wt.

Abstract: A member for a semiconductor structure is constructed, for example, as a mounting, or as a cover, or as a heat sink. Such a component is obtained by joining an aluminum nitride insulating substrate and a radiating element. The metal material for forming the radiating member has a thermal conductivity of at least 120 W/mK and a thermal expansion coefficient within a range of 4 to 6.0.times.10.sup.-6 /K.sup.-1. Preferably the material forming the radiating element is made of a tungsten alloy containing copper by not more than 5 percent by weight.

Abstract: A member for a semiconductor apparatus for carrying or holding a semiconductor device, obtained by joining an aluminum nitride substrate and a radiating substrate, comprises an insulating member formed by an aluminum nitride sintered body to be provided thereon with the semiconductor device, a radiating member to be joined to the insulating member, which radiating member is mainly formed of a copper-tungsten alloy or a copper-molybdenum alloy, a stress relieving member interposed between the insulating member and the radiating member and a silver solder member for joining the insulating member, the stress relieving member and the radiating member with each other.