Laminated ceramic electronic component and method for manufacturing same

• US 20020008606A1
• Filed: 05/22/2001
• Published: 01/24/2002
• Est. Priority Date: 05/22/2000
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Okuyama, Shingo, Nakagawa, Tadahiro
• Granted Patent: US 6,715,197 B2
• Time in Patent Office: Days
• US Class Current: 336/200
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 2017/0026 Multilayer LC-filter
• CPC Class Codes: H01F 41/043 by thick film techniques
• CPC Class Codes: H01G 4/30 Stacked capacitors H01G4/33 takes precedence
• CPC Class Codes: H03H 2001/0085 Multilayer, e.g. LTCC, HTCC, green sheets inside PCB filters H05K
• CPC Class Codes: H03H 3/00 Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
• CPC Class Codes: H03H 7/0115 comprising only inductors and capacitors H03H7/075, H03H7/09, H03H7/12, H03H7/13 take precedence
• CPC Class Codes: H05K 3/4629 laminating inorganic sheets comprising printed circuits, e.g. green ceramic sheets
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49126 Assembling bases
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/5317 Laminated device
• CPC Class Codes: Y10T 29/532 Conductor
• CPC Class Codes: Y10T 29/53204 Electrode

Abstract

A laminated ceramic electronic component significantly simplifies a step of forming external electrodes and has reliable electrical connection between an internal electrode and the external electrodes. A method for manufacturing the laminated ceramic electronic component includes the steps of forming composite sheets each having a conductor and a ceramic layer provided at the sides of the conductor on a carrier film, laminating the composite sheets with each other for forming a mother laminate, cutting the mother laminate in the thickness direction thereof so as to divide the conductor for forming laminates each forming one laminated ceramic electronic component, in which the conductor is exposed on the cut surface of the laminate, and firing the laminate so as to simultaneously form external electrodes from the exposed conductors and a sintered ceramic body.

Claims

1. A method for manufacturing a laminated ceramic electronic component, comprising steps of:

forming composite sheets each having a conductor and a ceramic layer provided at the side of the conductor on a carrier film;

laminating the composite sheets with each other to obtain a first laminated body;

cutting the first laminated body in the thickness direction thereof so as to divide the conductor to obtain a second laminated body having the conductor exposed on the cut surface; and

firing the second laminated body to obtain a sintered ceramic body having an external electrode formed of the exposed conductor.

2. The method according to claim 1, wherein the laminating step includes the steps of press-bonding the composite sheet formed on the carrier sheet to a lamination stage or to a composite sheet that was previously laminated, separating the carrier film from the composite sheet, and repeating the steps of press bonding and separating.

3. The method according to claim 1, wherein the laminating step includes the steps of separating the composite sheets from the carrier films, laminating the composite sheets with each other after separating, and compressing the laminated body in the thickness direction thereof.

4. The method according to claim 1, wherein the forming step includes a step of printing the conductor and the ceramic layer at least two times so as to form a composite sheet including a plurality of conductor layers and a plurality of ceramic layers.

5. The according to claim 1, wherein a planar configuration of the external electrode includes an edge surface portion extending along the cut surface exposed by the cutting and a pair of bent portions bent inside from the cut surface at the both ends of the edge surface portion.

6. The method according to claim 5, wherein the cutting step includes a step of cutting the first laminated body in a direction that is substantially perpendicular to the cut surface for forming a second laminated body to have a substantially rectangular body having a pair of edge surfaces and a pair of side surfaces connecting therewith, wherein the pair of bent portions are formed so as to extend to the pair of side surfaces.

7. The method according to claim 1, wherein the conductor of a composite sheet disposed at the outermost layer of the first laminated body has a bent portion extending inside from the edge surface portion of the external electrode that is exposed by the cutting.

8. The method according to claim 5, wherein the external electrode having the edge surface portion and the pair of bent portions is formed such that the inner portion of the corner defined by the edge surface portion and the bent portion has a substantially round shape.

9. The method according to claim 5, wherein the external electrode having the edge surface portion and the pair of bent portions is formed such that the outer portion of the corner defined by the edge surface portion and the bent portion has a substantially round shape.

10. The method according to claim 7, wherein a width of the edge surface portion of the external electrode including the edge surface portion and the pair of bent portions increases toward an outer surface of the laminated body along the laminating direction.

11. The method according to claim 7, wherein widths of the pair of bent portions of the external electrode including the edge surface portion and the pair of bent portions increase toward an outer surface of the laminated body along the laminating direction.

12. The method according to claim 1, wherein the forming step includes a step of forming a second conductor constituting an internal electrode at the same time when the conductor is formed.

13. The method according to claim 1, wherein in the firing step, the laminated body and a plurality of the external electrode are simultaneously formed.

14. The method according to claim 1, wherein a plurality of the external electrodes are formed during the step of firing and no additional steps are required for forming the plurality of external electrodes.

15. The method according to claim 1, further comprising the step of forming a plurality of internal electrodes and external electrodes so as to be electrically connected to each other, wherein the internal electrodes and external electrodes are fired at the same time during the step of firing.

16. A laminated ceramic electronic component manufactured according to the method of claim 1.

17. A laminated ceramic electronic component, comprising:

a sintered ceramic body that has been integrally fired; and

a plurality of external electrodes arranged so as to be exposed on the outer surface of the sintered ceramic body;

wherein the outer surface of the external electrode is flush with the outer surface of the sintered ceramic body.

18. The laminated inductor according to claim 17, further comprising a coil conductor disposed in the sintered ceramic body and connected to the external electrodes.

19. The laminated inductor according to claim 17, wherein at least one of the plurality of external electrodes has an edge surface portion extending along the edge surface of the sintered ceramic body and bent portions at the both ends of the edge surface portion, which extend in the direction away from the edge surface.