Chip resistor and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-10832837-B2
Application number	US-201916570447-A
Country	US
Kind code	B2
Filing date	Sep 13, 2019
Priority date	Feb 19, 2015
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

A chip resistor includes an upper electrode provided on a substrate, a resistor element connected to the upper electrode, and a side electrode connected to the upper electrode. The side electrode, arranged on a side surface of the substrate, has two portions overlapping with the obverse surface and reverse surface of the substrate, respectively. An intermediate electrode covers the side electrode, and an external electrode covers the intermediate electrode. A first protective layer is disposed between the upper electrode and the intermediate electrode, and held in contact with the upper electrode and the side electrode. The first protective layer is more resistant to sulfurization than the upper electrode. A second protective layer is disposed between the first protective layer and intermediate electrode, and held in contact with the first protective layer, side electrode and intermediate electrode.

First claim

The invention claimed is:

1. A chip resistor comprising:
a substrate including a first surface, a second surface opposite to the first surface, and a side surface disposed between the first surface and the second surface in a thickness direction of the substrate, the first surface including a first end part and a second end part that are spaced apart from each other in a first direction in plan view;
an upper electrode located on the first end part of the first surface;
a resistor element located on the first surface of the substrate and electrically connected to the upper electrode;
a first insulating layer covering the upper electrode and the resistor element;
a second insulating layer formed on the first insulating layer;
a protective layer formed on the upper electrode and including a portion located between the first insulating layer and the second insulating layer in the thickness direction; and
a side electrode electrically connected to the upper electrode and including a first portion and a second portion, the first portion being located on the side surface of the substrate, the second portion overlapping with the first surface of the substrate in plan view,
wherein the upper electrode includes a first portion located between the substrate and the resistor element in the thickness direction, and a second portion that does not overlap with the resistor element in plan view, and that has a uniform thickness,
the protective layer includes an inner surface held in contact with the upper electrode and an outer surface opposite to the inner surface, and the outer surface is greater in length measured in the first direction than the inner surface, and
the second portion of the side electrode and the second insulating layer have respective ends held in contact with each other on the outer surface of the protective layer.

2. The chip resistor according to claim 1 , wherein the protective layer is made of an electroconductive material.

3. The chip resistor according to claim 2 , wherein the protective layer comprises glass, metallic oxide and carbon black.

4. The chip resistor according to claim 1 , wherein the protective layer is greater in maximum thickness than the first insulating layer.

5. The chip resistor according to claim 1 , wherein the inner surface and the outer surface of the protective layer are flat.

6. The chip resistor according to claim 1 , wherein the end of the second insulating layer does not overlap with the inner surface of the protective layer in plan view.

7. The chip resistor according to claim 1 , wherein the first insulating layer has an end that is closer to the side surface of the substrate than is the second insulating layer in the first direction.

8. The chip resistor according to claim 1 , wherein the second portion of the side electrode is located on the protective layer and an entirety of the second portion of the side electrode is spaced apart from the upper electrode.

9. The chip resistor according to claim 1 , wherein the protective layer and the upper electrode have respective end faces held in contact with the first portion of the side electrode.

10. The chip resistor according to claim 9 , wherein the side surface of the substrate, the end face of the protective layer, and the end face of the upper electrode are flush with each other.

11. The chip resistor according to claim 1 , further comprising an intermediate electrode covering the side electrode, and an outer electrode covering the intermediate electrode.

12. The chip resistor according to claim 11 , wherein the side electrode is made of a Ni—Cr alloy, the intermediate electrode comprises a Ni-plating layer, and the outer electrode comprises a Sn-plating layer.

13. The chip resistor according to claim 11 , wherein the intermediate electrode and the outer electrode have respective ends held in contact with the second insulating layer.

14. The chip resistor according to claim 1 , wherein the first portion of the upper electrode has an inclined end face held in contact with the resistor element.

15. The chip resistor according to claim 1 , further comprising a rear electrode located on the second surface of the substrate and electrically connected to the side electrode.

16. The chip resistor according to claim 15 , wherein the rear electrode has an end face that is flush with the side surface of the substrate and held in contact with the first portion of the side electrode.

17. The chip resistor according to claim 15 , wherein the side electrode includes a third portion that is parallel to the first portion of the side electrode and held in contact with the rear electrode.

18. The chip resistor according to claim 15 , wherein the rear electrode is greater in length measured in the first direction than is the protective layer.

Assignees

• Rohm Co Ltd

Inventors

• Shinoura Takanori
• Imahashi Wataru

Classifications

• H01C3/00 Primary

  Non-adjustable metal resistors made of wire or ribbon, e.g. coiled, woven or formed as grids · CPC title

• H01C1/142 Primary

  the terminals or tapping points being coated on the resistive element · CPC title

• H01C17/006

  adapted for manufacturing resistor chips · CPC title

• H01C1/148

  the terminals embracing or surrounding the resistive element (H01C1/142 takes precedence) · CPC title

• H01C17/02

  adapted for manufacturing resistors with envelope or housing (apparatus or processes for filling or compressing insulating material in heating element tubes H05B3/52) · CPC title