Abstract: This invention relates to a graphite material for negative electrode of lithium secondary battery. This graphite material is obtained by carbonizing the pulverized green coke to yield coke, adding one kind or more of boron or a compound thereof to the coke, graphitizing the resulting mixture and controlling the particle size of the product graphite. This graphite material for negative electrode is characterized by showing a tap density of 0.95 g/cm3 or more after tapping 20 times or 1.15 g/cm3 or more after tapping 300 times and a BET specific surface area of 1.5 m2/g or less. A lithium secondary battery made by the use of this graphite material for negative electrode has a large discharge capacity and suffers little loss during charging and discharging.

Abstract: A method and apparatus for inspecting a bump electrode is almost independent of a surface condition of an object to be inspected. Before starting inspection, a template image is prepared by using a predetermined function. During inspection, a gradation correction of the photographed image is made by using a function with a saturation characteristic. The photographed image, which includes an image corresponding to at least one ball, is then segmented. Whether each bump electrode is an acceptable product or not is determined by pattern matching by calculating a normalized correlation coefficient between the segmented image and the template image prepared in advance.

Abstract: This invention relates to a graphite material for negative electrode of lithium secondary battery. This graphite material is obtained by carbonizing the pulverized green coke to yield coke, adding one kind or more of boron or a compound thereof to the coke, graphitizing the resulting mixture and controlling the particle size of the product graphite. This graphite material for negative electrode is characterized by showing a tap density of 0.95 g/cm3 or more after tapping 20 times or 1.15 g/cm3 or more after tapping 300 times and a BET specific surface area of 1.5 m2/g or less. A lithium secondary battery made by the use of this graphite material for negative electrode has a large discharge capacity and suffers little loss during charging and discharging.

Abstract: Carbonaceous particles and carbonaceous fibers whose surfaces are covered with a boron nitride thin film, wherein the atomic concentration of boron C(B), the atomic concentration of carbon C(C) and the atomic concentration of nitrogen C(N) satisfy the following inequalities: 0.05<C(B)/(C(B)+C(C)+C(N))<0.3 0.05<C(N)/(C(B)+C(C)+C(N))<0.3 in the surface region as measured by photoelectron spectroscopy. Also, lithium secondary batteries which employ these carbonaceous particles and carbonaceous fibers as negative electrode active materials.