Method of making mechanical-laser structure

• US 6,353,999 B1
• Filed: 05/06/1999
• Issued: 03/12/2002
• Est. Priority Date: 03/09/1999
• Status: Active Grant

• Current Assignee: Unimicron Taiwan Corporation
• Original Assignee: Unimicron Taiwan Corporation
• Inventors: Cheng, David C. H.
• Primary Examiner(s): Arbes, Carl J.
• Application Number:
  US09/306,340
• Time in Patent Office: 1,041 Days
• Field of Search: 298/52, 298/30, 298/25, 298/46, 427/97, 174/261, 174/266
• US Class Current: 29/852
• CPC Class Codes: H05K 2201/0187 with regions of different dielectrics in the same layer, e.g. in a printed capacitor for locally changing the dielectric properties
• CPC Class Codes: H05K 2201/09581 Applying an insulating coating on the walls of holes
• CPC Class Codes: H05K 2201/09809 Coaxial layout
• CPC Class Codes: H05K 3/0032 of organic insulating material
• CPC Class Codes: H05K 3/427 initial plating of through-holes in metal-clad substrates
• CPC Class Codes: H05K 3/429 Plated through-holes specially for multilayer circuits, e.g. having connections to inner circuit layers
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49165 by forming conductive walled aperture in base

Abstract

A mechanical-laser structure on a printed circuit board and a carrier. A method for fabricating the mechanical-laser structure includes the following steps. A substrate is provided. A first through hole is formed in the substrate by mechanical drilling. An epoxy plug is formed within the first through hole. A conductive layer is formed on the substrate by compression. The conductive layer is patterned to form conducting wires and exposes the epoxy plug. A micro via is formed within the epoxy plug by laser drilling.

Claims

1. A method for fabricating a mechanical-laser structure on a printed circuit board and a carrier, the method comprising:

providing a substrate;

forming a first through hole in the substrate by mechanical drilling;

filling epoxy resin within the first through hole to form a plug;

forming a first conductive layer on the substrate and the plug;

patterning the first conductive layer to form conducting wires, wherein the plug is exposed; and

forming a second through hole within the plug by laser ablating, wherein a diameter of the second through hole is smaller than the first through hole.

2. The method of claim 1, wherein the method further comprises forming a second conductive layer on a sidewall of the first through hole before forming the plug within the first through hole.

3. The method of claim 2, wherein the step of forming the second conductive layer includes electroplating.

4. The method of claim 1, wherein a conductive material fills the second through hole after forming the second through hole.

5. The method of claim 1, wherein a third conductive layer is formed on a sidewall of the second through hole after forming the second through hole.

6. The method of claim 5, wherein the step of forming the third conductive layer includes electroplating.

7. The method of claim 1, wherein the laser used for forming the second through hole includes carbon dioxide laser.

8. The method of claim 1, wherein the laser used for forming the second through hole includes Yttrium-Aluminum-Garnet laser.