Embedded circuit board and method of making same

Patent metadata

Field	Value
Publication number	US-10356909-B1
Application number	US-201816147593-A
Country	US
Kind code	B1
Filing date	Sep 29, 2018
Priority date	Jul 24, 2018
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

An embedded circuit board includes a flexible printed circuit board, a component, a conductive material, two adhesive layers, and two substrates. The flexible printed circuit board defines at least one cavity passing through the flexible printed circuit board. The flexible printed circuit board includes a base layer, a first conductive circuit layer formed on at least one surface of the base layer, and a protective layer formed on both sides of the base layer. The base layer and the first conductive circuit layer protrude into the cavity. The component is received within the cavity and abuts against the first conductive circuit layer protruding into the cavity. The conductive material is applied in a gap between the component and the first conductive circuit layer. The two substrates are adhered to the flexible printed circuit board by the two adhesive layers.

First claim

What is claimed is:

1. A method of making an embedded circuit board, the method comprising:
providing a flexible printed circuit board defining at least one cavity passing through the flexible printed circuit board, the flexible printed circuit board comprising a base layer, a first conductive circuit layer formed on at least one surface of the base layer, and a protective layer formed on each peripheral side of the flexible printed circuit board, the base layer and the first conductive circuit layer protruding into the cavity;
providing a fixture comprising a component and placing the flexible printed circuit board within the fixture to receive the component within the mounting slot to abut a side of the component against the first conductive circuit layer;
applying conductive material in a gap between the component and the first conductive circuit layer and solidifying the conductive material;
removing the fixture;
applying a colloid on an outer surface of each protective layer and placing a substrate on an outer surface of the colloid; and
laminating the substrate, the colloid, and the flexible printed circuit board together.

2. The method of claim 1 , wherein when the component is received within the cavity, the base layer and the first conductive circuit layer are bent by pressing.

3. The method of claim 2 , wherein a length of a bent portion of the base layer and the first conductive circuit layer is less than a length of portions of the base layer and the first conductive circuit layer protruding into the cavity.

4. The method of claim 1 , wherein the component is fixed to the fixture by a pre-fixing material; the fixture is removed by heating the fixture and the flexible printed circuit board to solidify the pre-fixing material to allow peeling off the fixture.

5. The method of claim 1 , wherein after the substrate, the colloid, and the flexible printed circuit board are laminated together, the substrate is surface-treated by etching, solder masking, and electroless nickel immersion gold processing.

6. The method of claim 1 , wherein the colloid, after being heated and pressed adheres the substrate, the flexible printed circuit board, and the component together.

7. An embedded circuit board comprising:
a flexible printed circuit board defining at least one cavity passing through the flexible printed circuit board, the flexible printed circuit board comprising a base layer, a first conductive circuit layer formed on at least one surface of the base layer, and a protective layer formed on both sides of the base layer, the base layer and the first conductive circuit layer protruding into the cavity;
a component received within the cavity and abutting against the first conductive circuit layer protruding into the cavity;
conductive material applied in a gap between the component and the first conductive circuit layer;
two adhesive layers; and
two substrates adhered to the flexible printed circuit board by the two adhesive layers.

8. The embedded circuit board of claim 7 , wherein the adhesive layers are located in a gap between the flexible printed circuit board and the component.

9. The embedded circuit board of claim 7 , wherein the substrate comprises: an epoxy glass cloth substrate adhered to the adhesive layer; and a second conductive circuit layer formed on a surface of the epoxy glass cloth substrate away from the adhesive layer.

10. The embedded circuit board of claim 7 , further comprising: a solder mask layer formed on a surface of the substrate away from the flexible 15 printed circuit board; and a metal layer formed on a surface of the solder mask layer away from the substrate.

11. The embedded circuit board of claim 7 , wherein the first conductive circuit layer comprises a bent portion abutting the component.

12. The embedded circuit board of claim 10 , wherein the first conductive circuit layer and the base layer comprise a bent portion; a length of the bent portion of the base layer and the first conductive circuit layer is less than a length of portions of the base layer and the first conductive circuit layer protruding into the cavity.

Assignees

• Avary Holding Shenzhen Co Ltd
• Hongqisheng Prec Electronics Qinhuangdao Co Ltd

Inventors

• Hou Ning
• Li Biao
• Zhong Hao-Wen
• Wang Ming-Hui

Classifications

• H05K3/321

  by conductive adhesives · CPC title

• H05K1/186 Primary

  manufactured by mounting on or connecting to patterned circuits before or during embedding · CPC title

• H05K1/118

  specially for flexible printed circuits, e.g. using folded portions · CPC title

• H05K3/007

  Manufacture or processing of a substrate for a printed circuit board supported by a temporary or sacrificial carrier (H05K1/187, H05K3/20 and H05K3/4682 take precedence) · CPC title

• H05K3/3452

  Solder masks · CPC title