Chip resistor and method for producing the same

• US 10,446,295 B2
• Filed: 01/23/2017
• Issued: 10/15/2019
• Est. Priority Date: 01/27/2016
• Status: Active Grant

• Current Assignee: KOA Corporation
• Original Assignee: KOA Corporation
• Inventors: Hiroshima, Yasushi
• Primary Examiner(s): Coleman, William
• Application Number:
  US16/072,318
• Publication Number:
  US 20190035520A1
• Time in Patent Office: 995 Days
• CPC Class Codes: B23K 26/382 by boring
• CPC Class Codes: C23C 14/0652 Silicon nitride
• CPC Class Codes: C23C 16/402 Silicon dioxide
• CPC Class Codes: H01C 1/028 the resistive element being embedded in insulation with outer enclosing sheath
• CPC Class Codes: H01C 1/032 plural layers surrounding the resistive element H01C1/028 takes precedence
• CPC Class Codes: H01C 1/14 Terminals or tapping points or electrodes specially adapted for resistors in general H01R; Arrangements of terminals or tapping points or electrodes on resistors
• CPC Class Codes: H01C 17/02 adapted for manufacturing resistors with envelope or housing
• CPC Class Codes: H01C 17/12 by sputtering
• CPC Class Codes: H01C 17/16 using electric current
• CPC Class Codes: H01C 7/006 Thin film resistors
• CPC Class Codes: H01C 7/023 containing oxides or oxidic compounds, e.g. ferrites
• CPC Class Codes: H01L 23/5228 Resistive arrangements or effects of, or between, wiring layers other resistive arrangements H01L23/647
• CPC Class Codes: H01L 28/24 with an active material comprising a refractory, transition or noble metal, metal compound or metal alloy, e.g. silicides, oxides, nitrides

Abstract

Provided is a thin-film chip resistor including an insulating substrate; a thin-film resistive element formed on the substrate; a pair of electrodes connected to the thin-film resistive element; and a protective film covering at least the thin-film resistive element between the pair of electrodes, in which the protective film includes a first protective film and a second protective film, the first protective film containing silicon nitride in contact with the thin-film resistive element, and the second protective film containing silicon oxide in contact with the first protective film.

Claims

1. A thin-film chip resistor comprising:

an insulating substrate;

a thin-film resistive element formed on the substrate;

a pair of electrodes connected to the thin-film resistive element; and

a protective film covering at least the thin-film resistive element between the pair of electrodes,

wherein;

the protective film includes a first protective film and a second protective film, the first protective film containing silicon nitride in contact with the thin-film resistive element, and the second protective film containing silicon oxide in contact with the first protective film.

2. The thin-film chip resistor according to claim 1, wherein a refractive index of the first protective film is 2.0 to 2.3 at a wavelength of 632.8 nm.

3. The thin-film chip resistor according to claim 1, wherein the first protective film contains an excessive amount of silicon, the amount being greater than an amount corresponding to a stoichiometric composition of silicon nitride Si:

N=3;

4.

4. The thin-film chip resistor according to claim 1, wherein the second protective film is thicker than the first protective film.

5. The thin-film chip resistor according to claim 1, wherein a thickness of the first protective film is 75 to 500 nm.

6. The thin-film chip resistor according to claim 1, further comprising an overcoat film covering a region between the pair of electrodes,

wherein:

the overcoat film is formed covering an opening that is formed in part of the thin-film resistive element.

7. A method for producing a thin-film chip resistor, comprising:

preparing an insulating substrate;

forming, on the substrate, a thin-film resistive element and a pair of electrodes connected to the thin-film resistive element, and forming a first protective film containing silicon nitride, the first protective film covering the thin-film resistive element between the pair of electrodes; and

forming a second protective film containing silicon oxide, the second protective covering the first protective film.

8. The method for producing a thin-film chip resistor according to claim 7, further comprising:

after forming the second protective film, forming an opening by removing part of a region of the thin-film resistive element and at least part of the first protective film and the second protective film that are formed above the part of the region.