Chip-type coil element

• US 4,926,151 A
• Filed: 12/21/1988
• Issued: 05/15/1990
• Est. Priority Date: 12/21/1987
• Status: Expired due to Term

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Morinaga, Tetsuya
• Primary Examiner(s): Harris, George
• Application Number:
  US07/287,726
• Time in Patent Office: 510 Days
• Field of Search: 335/281, 335/296, 335/297, 336/83, 336/192, 336/195, 336/196, 336/221
• US Class Current: 335/296
• CPC Class Codes: H01F 17/045 with core of cylindric geometry and coil wound along its longitudinal axis, i.e. rod or drum core
• CPC Class Codes: H01F 27/292 Surface mounted devices
• CPC Class Codes: H05K 3/3426 characterised by the leads
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A coil (33, 33a) is wound on a bobbin (22, 22a), one flange (24, 24a) of which has an end surface provided with a central projection (26, 26a) on its center and first and second end projections (27, 27a; 28, 28a) on its opposite end portions respectively, thereby to define first and second cavities (29, 29a; 30, 30a). First and second electrodes (31, 31a; 32, 32a) are provided to extend from the first and second end portions of the flange toward its side surface. First and second terminals (34, 34a; 35, 35a) of the coil are respectively received in the first and second cavities, which in turn are filled with solder members (36, 36a; 37, 37a) to electrically connect the first and second terminals to the first and second electrodes respectively. The first and second end projections are adapted to reduce the volume of solder required for mounting the chip-type coil element as well as to substantially prevent the coil element from inclination, thereby to prevent a tombstoning phenomenon.

Claims

1. A chip-type coil element comprising:

a bobbin having a core and first and second flanges provided on end portions of said core respectively, said first flange having an end surface extending perpendicularly to the longitudinal direction of said core and a side surface extending parallel to said longitudinal direction, said end surface of said first flange being provided with a central projection on its center and first and second end projections on its opposite end portions respectively, thereby to define first and second cavities between said central projection and said first and second end projections respectively;

a coil being wound on said core and having first and second terminals; and

first and second electrodes provided to extend from said first and second end projections toward said side surface;

said first and second terminals being received in said first and second cavities to be electrically connected to said first and second electrodes respectively.

2. A chip-type coil element in accordance with claim 1, wherein wall surfaces are provided defining said first and second cavities respectively, said electrodes extending toward said wall surfaces.

3. A chip-type coil element in accordance with claim 2, wherein said first and second cavities are filled with solder members while receiving said first and second terminals.

4. A chip-type coil element in accordance with claim 3, wherein said end surface of said first flange provides a substantially flat plane.

5. A chip-type coil element in accordance with claim 1, wherein said first and second end projections have rounded faces.