Sensing unit and method of making same

• US 20100154198A1
• Filed: 03/04/2010
• Published: 06/24/2010
• Est. Priority Date: 06/20/2007
• Status: Active Grant

• Current Assignee: Headway Technologies Incorporated, SAE Magnetics Limited (TDK Corporation)
• Original Assignee: Headway Technologies Incorporated, SAE Magnetics Limited (TDK Corporation)
• Inventors: Ishizaki, Kazuo, Sasaki, Yoshitaka, Horinaka, Takehiro, Tanemura, Shigeki, Shimizu, Tatsushi
• Granted Patent: US 8,302,285 B2
• Time in Patent Office: Days
• US Class Current: 29/592.100
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/105 by magnetically sensitive devices
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49007 Indicating transducer
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49146 with encapsulating, e.g., potting, etc.
• CPC Class Codes: Y10T 29/49171 with encapsulating
• CPC Class Codes: Y10T 29/49176 with molding of electrically insulating material
• CPC Class Codes: Y10T 29/4922 with molding of insulation

Abstract

In a sensing unit according to the present invention, a spring portion having a support portion and a movable portion is conductive. A signal of a sensor portion provided on the movable portion of the spring portion is transmitted via the spring portion. Hence, the sensing unit according to the present invention has a simple constitution with a small number of components, and a wire does not necessarily have to be provided for each sensor portion. As a result, a reduction in manufacturing cost, simplification of the manufacturing process, and so on are achieved.

Claims

1. A method of making a sensing unit having:

a substrate formed with a recessed portion;

a spring portion having a support portion provided on said substrate and a flat coil-shaped movable portion supported by said support portion so as to be capable of floating relative to said substrate; and

a sensor portion provided on said movable portion of said spring portion, for detecting displacement in said movable portion and transmitting a signal relating to said displacement via said spring portion,

said method comprising the steps of;

preparing a substrate on which a first region for forming said movable portion of said spring portion is lower than a second region for forming said support portion;

burying said first region in a resist layer such that said substrate is made flat;

forming a plating layer that is to become said spring portion such that a part that is to become said movable portion is positioned on said resist layer in said first region and a part that is to become said support portion is positioned in said second region;

forming said sensor portion in said part of said plating layer that is to become said movable portion; and

removing said resist layer.