Chip inductor and manufacturing method therefor

• US 6,538,547 B2
• Filed: 05/09/2001
• Issued: 03/25/2003
• Est. Priority Date: 05/09/2000
• Status: Expired due to Term

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Amaya, Keishiro, Tamezawa, Eita
• Primary Examiner(s): Enad, Elvin
• Assistant Examiner(s): Poker, Jennifer A.
• Application Number:
  US09/850,952
• Publication Number:
  US 20020167387A1
• Time in Patent Office: 685 Days
• Field of Search: 336/200, 296/021, 298/25, 298/46, 294/12, 294/13, 294/14, 219/121
• US Class Current: 336/200
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 41/041 Printed circuit coils apparatus or processes for manufacturing printed circuits in general H05K3/00
• CPC Class Codes: H01L 27/08 including only semiconductor components of a single kind
• CPC Class Codes: H01L 28/10 Inductors
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49789 Obtaining plural product pieces from unitary workpiece
• CPC Class Codes: Y10T 29/4979 Breaking through weakened portion
• CPC Class Codes: Y10T 29/49792 Dividing through modified portion

Abstract

A chip inductor has electrode layers, insulating layers disposed on the electrode layers, and an uppermost insulating layer all disposed on a ceramic board. An inorganic pigment such as a Co oxide or an Al oxide is added to the insulating layer at a concentration of from about 2% to about 20% by weight. Break grooves are formed in the form of a lattice on the insulating layer by a laser beam irradiation, and the board is divided along the grooves. By adding the inorganic pigment, the break grooves are effectively formed, and the mother board is divided accurately along the break grooves, such that a chip inductor having an increased L value and an increased Q value is produced.

Claims

1. A method for manufacturing a chip inductor comprising the steps of:

forming electrode layers having specific patterns and insulating layers on a ceramic mother board;

forming an insulating layer as an uppermost layer to which a pigment including an inorganic oxide is added within the range of about 2% to about 20% by weight;

forming grooves by irradiating the uppermost insulating layer with a laser beam; and

dividing the mother board along said grooves.

2. A method for manufacturing a chip inductor according to claim 1, where said step of forming grooves includes forming lattice-shaped grooves.

3. A method for manufacturing a chip inductor according to claim 1 further comprising the step of forming grooves on the bottom surface of said mother board which correspond to the grooves formed on said uppermost insulating layer.

4. A method for manufacturing a chip inductor according to claim 1, wherein said grooves formed on the uppermost insulating layer have a width of about 30 μ

m.

5. A method for manufacturing a chip inductor according to claim 1, wherein said grooves formed on the uppermost insulating layer have a depth of about 50 μ

m.

6. A method for manufacturing a chip inductor according to claim 1, wherein said step of forming grooves is performed by a YAG laser.

7. A method for manufacturing a chip inductor according to claim 1, wherein said inorganic oxide is a Co oxide and/or an Al oxide.

8. A method for manufacturing a chip inductor according to claim 1, wherein the thickness of said uppermost insulating layer is from about 20 μ

m to about 30 μ

m.

9. A method for manufacturing a chip inductor according to claim 1, wherein said inorganic oxide is selected from the group consisting of Co, Al, Fe, and Mn.

10. A method for manufacturing a chip inductor according to claim 1, wherein said uppermost insulating layer is composed of glass as a main component.

11. A method for manufacturing a chip inductor according to claim 1, wherein said step of dividing the mother board along said grooves is performed by roller breaking.

12. A method for manufacturing a chip inductor according to claim 1, the step of forming grooves on the bottom surface of said mother board which correspond to the grooves formed on said uppermost insulating layer is performed by irradiating said mother board with a laser beam.