Method of manufacturing coil unit in thin film type for compact actuator

• US 10,186,375 B2
• Filed: 12/23/2016
• Issued: 01/22/2019
• Est. Priority Date: 07/14/2016
• Status: Active Grant

• Current Assignee: Kbchem Co., Ltd.
• Original Assignee: EneBrain Co., Ltd.
• Inventors: Kwon, Joung Sek
• Primary Examiner(s): Chan, Sing P
• Application Number:
  US15/390,404
• Publication Number:
  US 20180019058A1
• Time in Patent Office: 760 Days
• Field of Search: 156248, 156249, 156267, 156305, 1563071, 1563073, 156701, 156703, 156704
• CPC Class Codes: H01F 2007/068 using printed circuit coils
• CPC Class Codes: H01F 2027/2809 on stacked layers
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 41/041 Printed circuit coils apparatus or processes for manufacturing printed circuits in general H05K3/00
• CPC Class Codes: H01F 41/042 by thin film techniques
• CPC Class Codes: H01F 41/10 Connecting leads to windings making electric connections in general H01R43/00
• CPC Class Codes: H01F 7/06 Electromagnets; Actuators including electromagnets electric coils H01F5/00; devices for holding workpieces using electric force B23Q3/15; load-engaging elements for lifting articles electromagnetically B66C1/06; electromagnetic couplings F16D27/00; magnetic brakes F16D63/002; electromagnetically operated valves F16K11/24, F16K31/00; analysing materials by magnetic means G01N27/72, G01N27/80; electromagnets for winding mechanical clocks G04C1/02; electromagnetic relays H01H51/00; windings for salient poles of dynamo-electric machines H02K3/18; electromagnets for telegraphic communication H04L; for arc lamps H05B31/28

Abstract

Provided is a method of manufacturing a coil unit in a thin film type for a compact actuator, and more particularly, a method of manufacturing a coil unit in a thin film type for a compact actuator in which a buffer layer is formed on a coil layer to prevent cracks in the coil layer and a substrate.

According to the method of manufacturing the coil unit in a thin film type for a compact actuator of the present invention, the buffer layer is formed on the coil layer so that an impact to the coil layer during a back-grinding process for thinning a substrate is absorbed, thereby preventing the substrate and the coil layer from breaking due to the back-grinding process and compensating for a difference of deformation between the coil unit and the substrate according to a difference of coefficients of thermal expansion.

Further, according to the present invention, as the substrate is thinned by performing a back-grinding process, a gap which is a distance between a permanent magnet and the coil layer is reduced, and therefore sensitivity of the compact actuator can be improved.

Claims

1. A method of manufacturing a coil unit in a thin film type for a compact actuator, comprising:

a first step of laminating one or more coil layers on a substrate;

a second step of forming a buffer layer on the one or more coil layers;

a third step of forming an adhesive layer on the buffer layer to fix the coil unit on the adhesive layer and back-grinding a back surface of the substrate; and

a fourth step of removing the adhesive layer and mounting the coil unit manufactured by cutting a portion of a side of the substrate on a surface of a flexible printed circuit board (“

FPCB”

).

2. The method of claim 1, wherein:

a material of the coil included in the coil layer in the first step includes a metal conductor formed of copper as a main component;

the metal conductor has a height in a range of 10 μ

m to 80 μ

m;

the metal conductor has a line width in a range of 5 μ

m to 50 μ

m;

the metal conductor is formed to be spaced apart by an insulating layer; and

the insulating layer has a thickness in a range of 1 μ

m to 10 μ

m.

3. The method of claim 1, wherein, when a plurality of coil layers are laminated in the first step, an insulating layer is formed between a lower coil layer and an upper coil layer and the insulating layer has a thickness in a range of 1 μ

m to 30 μ

m.

4. The method of claim 1, wherein:

one or more bump pads are formed on a portion of an upper part of the coil layer to cause the coil layer to conduct between the first step and the second step; and

the buffer layer is applied on the upper part of the coil layer except a space at which the bump pads are formed using a filler.

5. The method of claim 4, wherein the coil layer is a patterned coil, and the filler is applied and cured in the same pattern as the coil.

6. The method of claim 4, wherein a height of the filler is equal to or less than a height of the bump pads.

7. The method of claim 1, wherein the substrate is back-ground to a thickness of 1 μ

m to 40 μ

m.