CIRCUIT BOARD AND MANUFACTURING METHOD THEREOF

• US 20100252303A1
• Filed: 04/01/2010
• Published: 10/07/2010
• Est. Priority Date: 04/02/2009
• Status: Active Grant

• Current Assignee: Unimicron Technology Corporation
• Original Assignee: Unimicron Technology Corporation
• Inventors: Chang, Chen-Chuan
• Granted Patent: US 8,450,616 B2
• Time in Patent Office: Days
• US Class Current: 174/251
• CPC Class Codes: H05K 1/183 Components mounted in and supported by recessed areas of the printed circuit board
• CPC Class Codes: H05K 2201/09036 Recesses or grooves in insulating substrate
• CPC Class Codes: H05K 2201/09127 PCB or component having an integral separable or breakable part
• CPC Class Codes: H05K 2201/09781 Dummy conductors, i.e. not used for normal transport of current; Dummy electrodes of components
• CPC Class Codes: H05K 2203/0554 Metal used as mask for etching vias, e.g. by laser ablation
• CPC Class Codes: H05K 3/0035 of blind holes, i.e. having a metal layer at the bottom
• CPC Class Codes: H05K 3/007 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 Class Codes: H05K 3/06 the conductive material being removed chemically or electrolytically, e.g. by photo-etch process semi-additive methods H05K3/108
• CPC Class Codes: H05K 3/062 consisting of metals or alloys or metallic inorganic compounds H05K3/065 takes precedence
• CPC Class Codes: H05K 3/108 by semi-additive methods; masks therefor characterised by metallic etch mask H05K3/062; electroplating methods or apparatus H05K3/241
• CPC Class Codes: H05K 3/428 initial plating of through-holes in substrates having a metal pattern
• CPC Class Codes: H05K 3/4697 having cavities, e.g. for mounting components H05K3/4691 takes precedence
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49156 with selective destruction of conductive paths

Abstract

A circuit board having a removing area is provided. The circuit board includes a first dielectric layer, a first laser resistant structure disposed on the first dielectric layer and located at the periphery of the removing area, a second dielectric layer disposed on the first dielectric layer, a circuit layer disposed on the second dielectric layer, a second laser resistant structure disposed on the second dielectric layer and located at the periphery of the removing area, and a third dielectric layer disposed on the second dielectric layer. The second laser resistant structure is insulated from the circuit layer. There is a gap between the second laser resistant structure and the circuit layer, and the vertical projection of the gap on a first surface overlaps the first laser resistant structure. The third dielectric layer exposes the portion of the circuit layer within the removing area.

Claims

1. A circuit board, having a removing area, the circuit board comprising:

a first dielectric layer;

a first laser resistant structure, disposed on a first surface of the first dielectric layer and located at a periphery of the removing area;

a second dielectric layer, disposed on the first dielectric layer and covering the first laser resistant structure;

a circuit layer, disposed on a second surface of the second dielectric layer, wherein a portion of the circuit layer is extended from outside of the removing area into the removing area;

a second laser resistant structure, disposed on the second surface, located at the periphery of the removing area, and insulated from the circuit layer, wherein there is at least one gap between the second laser resistant structure and the circuit layer, and a vertical projection of the gap on the first surface overlaps the first laser resistant structure; and

a third dielectric layer, disposed on the second dielectric layer, and having an opening corresponding to the removing area, wherein the opening exposes a portion of the circuit layer located within the removing area and the third dielectric layer covers a portion of the second laser resistant structure.

2. The circuit board according to claim 1, wherein the second laser resistant structure is an annular structure, the annular structure has at least one nick, and the circuit layer is extended from the nick into the removing area.

3. The circuit board according to claim 1, wherein the first laser resistant structure comprises a plurality of punctual structures independent from each other when there are multiple gaps between the second laser resistant structure and the circuit layer.

4. The circuit board according to claim 1, wherein the first laser resistant structure comprises a strip structure or an annular structure and the strip structure or the annular structure overlaps a vertical projection of the second laser resistant structure on the first surface.

5. The circuit board according to claim 1, wherein the second dielectric layer has at least one cavity located below the gap and the cavity exposes the first laser resistant structure.

6. The circuit board according to claim 1 further comprising a third laser resistant structure, the third laser resistant structure is disposed on the second surface and located at the periphery of the removing area, and the third laser resistant structure is connected with a portion of the circuit layer located at the periphery of the removing area and is insulated from the second laser resistant structure.

7. The circuit board according to claim 1 further comprising a protection layer, wherein the protection layer covers the portion of the circuit layer located within the removing area.

8. The circuit board according to claim 1, wherein the opening exposes a portion of the second laser resistant structure located within the removing area.

9. A manufacturing method of a circuit board, comprising:

providing a substrate, wherein the substrate has a pre-removing area, and the substrate comprises;

a first dielectric layer;

a first laser resistant structure, disposed on a first surface of the first dielectric layer and located at a periphery of the pre-removing area;

a second dielectric layer, disposed on the first dielectric layer and covering the first laser resistant structure;

a circuit layer, disposed on a second surface of the second dielectric layer, wherein a portion of the circuit layer is extended from outside of the pre-removing area into the pre-removing area;

a second laser resistant structure, disposed on the second surface, located at the periphery of the pre-removing area, and insulated from the circuit layer, wherein there is at least one gap between the second laser resistant structure and the circuit layer, and a vertical projection of the gap on the first surface overlaps the first laser resistant structure;

a third dielectric layer, disposed on the second dielectric layer, and covering the circuit layer and the second laser resistant structure;

performing a laser machining process to etch the third dielectric layer located at the periphery of the pre-removing area; and

removing a portion of the third dielectric layer located within the pre-removing area.

10. The manufacturing method according to claim 9, wherein the laser machining process further comprises etching a portion of the second dielectric layer located below the gap.

11. The manufacturing method according to claim 9, wherein the technique of removing the third dielectric layer comprises a lift-off technique.

12. The manufacturing method according to claim 9, wherein the second laser resistant structure is an annular structure, the annular structure has at least one nick, and the circuit layer is extended from the nick into the pre-removing area.

13. The manufacturing method according to claim 9, wherein the first laser resistant structure comprises a plurality of punctual structures independent from each other when there are multiple gaps between the second laser resistant structure and the circuit layer.

14. The manufacturing method according to claim 9, wherein the first laser resistant structure comprises a strip structure or an annular structure and the strip structure or the annular structure overlaps a vertical projection of the second laser resistant structure on the first surface.

15. The manufacturing method according to claim 9, wherein the substrate further comprises a third laser resistant structure, the third laser resistant structure is disposed on the second surface and located at the periphery of the pre-removing area, and the third laser resistant structure is connected with a portion of the circuit layer located at the periphery of the pre-removing area and is insulated from the second laser resistant structure.

16. The manufacturing method according to claim 9, wherein the substrate further comprises a protection layer, and the protection layer covers a portion of the circuit layer located within the pre-removing area.

17. The manufacturing method according to claim 9 further comprising:

performing an etching process or a mechanical processing to remove the second laser resistant structure.

18. The manufacturing method according to claim 9 further comprising:

performing an etching process or a mechanical processing to remove the first laser resistant structure.

19. A circuit board, having a removing area, the circuit board comprising:

a first dielectric layer;

a circuit layer, disposed on a surface of the first dielectric layer, wherein a portion of the circuit layer is extended from outside of the removing area into the removing area;

a laser resistant structure, disposed on the surface, located at the periphery of the removing area, and insulated from the circuit layer, wherein there is at least one gap between the laser resistant structure and the circuit layer; and

a second dielectric layer, disposed on the first dielectric layer, and having an opening corresponding to the removing area, wherein the opening exposes a portion of the circuit layer located within the removing area.