Yamaha Corporation

Michio Miura

Kenzaburou Iijima

Koji Toda

Hideaki Tsubakida

A fine pitch electrode is provided in which fine electrode lines are disposed at even intervals and with high precision, and which has improved productivity and quality. The fine-pitch electrode,comprises a plurality of fine electrode lines,, each of which is coated around its periphery with a coating film which is made of an electrical insulator, and a sealing member,in which a plurality of the fine electrode lines,are disposed on a plane and which is molded so as to incorporate the fine electrode lines

Fine-pitch electrode, process for producing the same, and fine-pitch electrode unit

A semiconductor chip mounting method consisting of steps is performed to mount a semiconductor chip on a substrate. Herein, an electrode is formed on a main surface of the semiconductor chip and is covered with an insulating film. A contact hole is formed through the insulating film to be in contact with a part of the electrode. In addition, a Ni layer is formed to cover the contact hole. A wiring layer is formed on a main surface of the substrate and is covered with an insulating film. To achieve laser beam bonding effected between the semiconductor chip and substrate, a solder is provided for either the semiconductor chip or the substrate. For example, it is possible to provide a solder layer which is formed through a part of the insulating film to be in contact with the wiring layer of the substrate; or it is possible to provide a solder bump which projects from a concavity of the Ni layer of the semiconductor chip. Next, a laser beam is irradiated through the substrate, having laser beam permeability, and toward the solder. Thus, the semiconductor chip is bonded together with the substrate. Incidentally, a diameter in irradiation of the laser beam can be narrowed within a range between 1 .mu.m and 25 .mu.m, for example. This brings a reduction in a contact area between the semiconductor chip and substrate which are bonded together. Results of our studies show that a good electric connection can be provided between the electrode of the semiconductor chip and the wiring layer of the substrate under a limited condition where the Ni layer and the wiring layer both have a thickness which ranges between 0.6 .mu.m and 3 .mu.m, for example.

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Hamamatsu, Japan

Michio Miura