Fujitsu Corporation

Nobutaka Ito

Kanako Imai

Fumihiko Ando

Shuuichi Nakajima

Kanako Murakami

A method of evaluating configuration of solder external terminals of a BGA-type tape-based semiconductor device mounted on a board such that the external terminals are joined to lands provided on the mounting board is provided. The method includes the step of obtaining geometric data related to opening of a tape substrate of the semiconductor device, solder balls to be placed at positions corresponding to the openings, and the lands of the mounting board and the step of deribing configuration of the solder external terminal based on the geometric date. The method further includes the step of calculating the volume of voids to be produced in the external terminals, so as to compensate for the geometric data related to the tape substrate.

Method, apparatus and computer readable medium for evaluating configuration of solder external terminals of a semiconductor device

A method forms an analyzing model for use in finite element method analysis. The method includes the steps of (a) detecting faces of elements of the analyzing model which do not make contact with faces of other elements, based on information related to the analyzing model which is used in the finite element method analysis and describes a target unit which is to be analyzed, (b) grouping the faces of the elements detected in said step (a) into first groups for each of face numbers which are assigned with respect to each of the faces for the sake of convenience, (c) out of the elements having the faces included in each of the first groups obtained in said step (b), extracting elements having element numbers with the same increase number and grouping the extracted elements in second groups, where the element numbers are assigned with respect to each of the elements for the sake of convenience, (d) storing storage information with respect to the elements included in each of the second groups obtained in said step (c), where said storage information includes an element initial number, an element final number, an element number increase value and a face number included in the element, (e) specifying a range of the faces formed by the elements extracted in said step (c) with respect to said storage information, (f) newly forming solid finite elements in a space which is formed by the faces in the range specified by said step (e), (g) forming information which defines boundary conditions at faces outside the range specified by said step (e), and (h) changing conditions values depending on position coordinates of the faces in the definition of said boundary conditions of the faces.

Method and apparatus for forming a model for use in finite element

A method of designing an optimum skeleton structure uses a computer to obtain a skeleton structure from a density distribution within a 2 or 3 dimensional design region which is obtained as an optimum shape of a mechanical structure, where the design region is divided into finite elements each having a density D assigned thereto. The method includes the steps of (a) inputting a first reference value D.sub.S of the density D, (b) regarding a point within the design region where an external force is applied as one of starting point candidates, (c) selecting a starting point which is non-selected from the starting point candidates, (d) extending a line from the starting point and passing through the finite element satisfying D.gtoreq.D.sub.S so that the line is as straight as possible, and (e) stopping the extension of the line and regarding the line as a skeleton member when no adjacent finite element satisfying D.gtoreq.D.sub.S exists or when a non-selected starting point candidate is reached. The steps (c) through (e) are repeated until no more non-selected starting point candidate exists.

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Kawasaki, Japan

Nobutaka Ito