Study of Mass Production of Low Ohm Metal Film Resistors Prepared by Electroless Plating

Hiroo AOKI

Summary :

The low ohm metal film resistors under 1Ω can be made by electroless Ni-P plating. However, they are not suitable for precise use because their TCR can not become less than 100 ppm/. So the author developed Ni-W-P metal film resistors with its TCR is equal to conventional precision metal film resistors, by changing the ratio of ingredients in plating bath. At first on this paper, the trade-off point of ingredients ratio with respect to TCR and depositing rate has been investigated, assuming mass-production of 30,000 resistors in a lot. And then reliability tests, including short time over-load, temperature cycle, pulse, step stress, load life and moisture load life, were carried out for both conventional Ni-P and Ni-W-P metal film resistors. Before the tests, the films were grooved by laser and mechanical cutting. As the result, it has been found that the Ni-W-P is superior to the Ni-P, especially in step stress and pulse, and that laser cutting is found preferable to mechanical cutting.

• Publication: IEICE TRANSACTIONS on Electronics Vol.E74-C No.7 pp.2049-2054
• Publication Date: 1991/07/25
• Type of Manuscript: PAPER
• Category: Components

Authors

Hiroo AOKI

Keyword