Chip resistor and method for producing the same

Abstract

A chip resistor includes: an insulating chip substrate 11 having an upper surface formed with a resistive film 12 and a pair of left and right upper electrodes 13 at two ends thereof; a cover coat 14 covering the resistive film; auxiliary upper electrodes 15 formed on upper surfaces of the upper electrodes 13 to overlap the cover coat 14; a left and a right side electrodes 16 formed on a left and a right end surfaces 11a of the insulating substrate 11; and metal plate layers formed on surfaces of the auxiliary upper electrodes and side electrodes. The cover coat 14 is formed with an uppermost over coat 19 covering a region where the auxiliary upper electrodes 15 overlap the cover coat 14, whereby the upper electrodes 13 and the auxiliary upper electrodes 15 are protected from migration caused by sulfur gases.

Description

technical field [0001] The present invention relates to a chip resistor in which at least one resistive film, terminal electrodes at both ends, and a cover coat covering the resistive film are formed on a chip-shaped insulating substrate, and a method for manufacturing the same. Background technique [0002] Conventionally, this kind of chip resistor is described in, for example, JP-A-56-148804, since it is a form in which an overcoat layer covering at least one resistive film protrudes high from the central part of the upper surface of an insulating substrate, so in this When the chip resistor is adsorbed on a vacuum-adsorption type collet, there are disadvantages such as failure of adsorption or cracks in the outer coating. [0003] Here, a newest chip resistor is described in Japanese Unexamined Patent Publication No. 8-236302 as the prior art, and, by figure 1 The configuration shown eliminates the above-mentioned disadvantages. [0004] That is, the structure of the c...

AI Technical Summary

Problems solved by technology

[0006] However, in the above-mentioned prior art, similarly to the two upper electrodes 3 positioned at both ends of the resistance film 2, a conductive paste (hereinafter referred to as silver paste) mainly composed of silver having low resistance is applied, and then sintered. Form the auxiliary upper electrode 5, although the auxiliary upper electrode 5 is covered with a metal coating 8, since the metal coating 8 is not tightly bonded to the outer coating, sulfur-containing gases such as hydrogen sulfide in the atmosphere flow from the metal coating and the outer coating. The portion between the outer coats penetrates into the portion of the auxiliary upper surface electrode 5 made of the above-mentioned silver paste that overlaps with the outer coat, and corrosion or the like caused by migration of sulfur-containing gas occurs in this portion, and the migration The corrosion of etc. continues to the upper electrode 3, and there is a problem that not only the resistance value changes, but also the upper electrode is eventually disconnected.

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