Abstract: Provided herein is a flux-coated ball having a ball-like joining material and a flux layer that covers a surface of the joining material. The flux layer is formed from high volatile flux solvent including ethyl acetate, acetone or methyl ethyl ketone. Thickness of the flux layer ranges from 2.5 ?m to 50 ?m. A diameter of the flux-coated ball is 600 ?m or less. A sphericity of the flux-coated ball is 0.9 or more.

Abstract: Produced is a metal ball which suppresses an emitted ? dose. Contained are the steps of melting a pure metal by heating the pure metal at a temperature which is higher than a boiling point of an impurity to be removed, higher than a melting point of the pure metal, and lower than a boiling point of the pure metal, the pure metal containing a U content of 5 ppb or less, a Th content of 5 ppb or less, purity of 99.9% or more and 99.995% or less, and a Pb or Bi content or a total content of Pb and Bi of 1 ppm or more, and the pure metal having the boiling point higher than the boiling point at atmospheric pressure of the impurity to be removed; and sphering the molten pure metal in a ball.

Abstract: A Cu ball that has low ? dose and high sphericity even when containing at least a certain amount of impurity elements other than Cu. Even when the purity thereof is 99.995% or less and U and Th contents are 5 ppb or less in order to suppress any software errors and decrease connection failure, ? dose is 0.0200 cph/cm2 or less. Further, the sphericity of the Cu ball is unexpectedly improved by making the purity not more than 99.995%.

Abstract: Provided are a Ni ball, a Ni core ball, a solder joint, solder paste and foamed solder which are superior in the impact resistance to dropping and can inhibit any occurrence of a poor joints. An electronic component 60 is constructed by joining a solder bump 30 of a semiconductor chip 10 to an electrode 41 of a printed circuit board 40 with solder paste 12, 42. The solder bump 30 is formed by joining an electrode 11 of the semiconductor chip 10 to the Ni ball 20. The Ni ball 20 according to the present invention contains purity which is equal to or higher than 99.9% and equal to or lower than 99.995%, sphericity which is equal to or higher than 0.90, and Vickers hardness which is equal to or higher than 20 HV and equal to or less than 90 HV.

Abstract: To provide a Ni ball having a low ? dose and high sphericity even when it contains impurity elements other than Ni in certain amounts. The Ni ball contains an element U, a content thereof being 5 ppb or less, and an element Th, a content thereof being 5 ppb or less, wherein a purity of the Ni ball is 99.9% or more but 99.995% or less, an ? dose thereof is 0.0200 cph/cm2 or less, a content of either Pb or Bi, or a total content of both Pb and Bi is 1 ppm or more, and a sphericity thereof is 0.90 or more, in order to prevent any software errors and reduce connection failure.

Abstract: A Cu core ball is provided that prevents any soft errors and decreases any connection failure. The Cu core ball includes a solder plating film formed on the surface of a Cu ball that is a Sn solder plating film or is made of a lead-free solder alloy, a principal ingredient of which is Sn. The solder plating film contains U of 5 ppb or less and Th of 5 ppb or less. The Cu ball has a purity of not less than 99.9% Cu and not more than 99.995% Cu. Pb and/or Bi contents therein are at a total of 1 ppm or more. The sphericity thereof is 0.95 or more. The obtained Cu core ball has an ? dose of 0.0200 cph/cm2 or less.

Abstract: A core ball wherein a junction melting temperature and a low alpha dose are set for suppressing a soft error generation and solving a mounting problem. A metallic powder as a core is a sphere. A pure degree of a Cu ball of the metallic powder is equal to or higher than 99.9% but equal to or less than 99.995%. A contained amount of one of Pb and Bi or a total contained amount of Pb and Bi is equal to or higher than 1 ppm. A sphericity of the Cu ball is at least 0.95. A solder plating film for coating the Cu ball comprises Sn—Bi based alloy. U contained in the solder plating film is equal to or less than 5 ppb and Th is equal to or less than 5 ppb. An alpha dose of the core ball is equal to or less than 0.0200 cph/cm2.

Abstract: Providing an Ag ball having a low alpha dose and a high sphericity regardless of impurity elements having an amount equal to or more than a predetermined value except for Ag. In order to suppress a soft error and reduce an connection fault, a content of U is equal to or less than 5 ppb, a content of Th is equal to or less than 5 ppb, a purity is equal to or more than 99.9% but equal to or less than 99.9995%, an alpha dose is equal to or less than 0.0200 cph/cm2, a content of either Pb or Bi or a total content of both Pb and Bi is equal to or more than 1 ppm, and a sphericity is equal to or more than 0.90.

Abstract: To provide Cu ball that has an excellent alignment performance. In order to control wettability failure of the Cu ball at a moment of soldering, lightness is regulated as an index of determining oxide film thickness on a surface of the ball and the lightness is set to be 55 or more. Further, since it is preferable that the Cu ball has a higher sphericity to measure the lightness accurately, the purity of the Cu ball is set to be 99.995% or less to order to make the sphericity higher. When the lightness is 55 or more, it is preferable that the thickness of oxide film formed on the surface of the Cu ball is 8 nm or less.

Abstract: To provide Cu ball that has less ? dose and high sphericity even when containing at least a certain amount of impurity elements other than Cu. Even when the purity thereof is 99.995% or less and U and Th contents are 5 ppb or less in order to suppress any software errors and decrease connection failure, ? dose is 0.0200 cph/cm2 or less. Further, the sphericity of the Cu ball is unexpectedly improved by making the purity not more than 99.995%.

Abstract: Providing an Ag ball having a low alpha dose and a high sphericity regardless of impurity elements having an amount equal to or more than a predetermined value except for Ag. In order to suppress a soft error and reduce an connection fault, a content of U is equal to or less than 5 ppb, a content of Th is equal to or less than 5 ppb, a purity is equal to or more than 99.9% but equal to or less than 99.9995%, an alpha dose is equal to or less than 0.0200 cph/cm2, a content of either Pb or Bi or a total content of both Pb and Bi is equal to or more than 1 ppm, and a sphericity is equal to or more than 0.90.

Abstract: Providing a core ball wherein a junction melting temperature and a low alpha dose are set for suppressing a soft error generation and solving a mounting problem. A metallic powder as a core is a sphere. A pure degree of a Cu ball of the metallic powder is equal to or higher than 99.9% but equal to or less than 99.995%. A contained amount of one of Pb and Bi or a total contained amount of Pb and Bi is equal to or higher than 1 ppm. A sphericity of the Cu ball is equal to or higher than 0.95. A solder plating film for coating the Cu ball comprises Sn—Bi based alloy. U contained in the solder plating film is equal to or less than 5 ppb and Th is equal to or less than 5 ppb. An alpha dose of the core ball is equal to or less than 0.0200 cph/cm2.

Abstract: A Cu core ball suppresses a soft error and its alpha dose is low. Its surface roughness does not affect a mounting process. A pure degree of the Cu ball as an internal ball is equal to or larger than 99.9% and equal to or less than 95%. A total contained amount of Pb and/or Bi in impurity contained in the Cu ball is equal to or larger than 1 ppm. Its sphericity is equal to or higher than 0.95. A solder plating film coated on the Cu ball is a Sn solder plating film or a solder plating film comprising a lead free solder alloy whose primary component is Sn. In the solder plating film, a contained amount of U is equal to or less than 5 ppb and that of Th is equal to or less than 5 ppb. A total alpha dose of the Cu ball and the solder plating film is equal to or less than 0.0200 cph/cm2. An arithmetic average roughness of the Cu core ball is equal to or less than 0.3 ?m.

Abstract: A connector housing has an insertion slot for receiving a companion base board, a plurality of grooves defined in a housing bottom in a direction normal to the insertion slot, and a plurality of pin attachment holes disposed between the insertion slot and the grooves. Contact pins are approximately L-shaped and pivotally held in the pin attachment holes, respectively, in the vicinity of central bent portions of the contact pins. When the connector housing is attached to a base board and the companion board is inserted in the insertion slot, ends of the contact pins are connected to a circuit pattern on the base board and opposite ends of the contact pins are connected to a circuit pattern on the companion board. The base and companion boards are therefore electrically connected to each other substantially perpendicularly to each other.