Electronic assembly that includes void free holes

Patent metadata

Field	Value
Publication number	US-10856424-B2
Application number	US-201515762856-A
Country	US
Kind code	B2
Filing date	Sep 25, 2015
Priority date	Sep 25, 2015
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

A method that includes electroplating both sides of a core and the through hole of a core with a conductive material to cover both sides of the core with the conductive material and to form a conductive bridge in the through hole, wherein the core has a thickness greater than 200 microns; etching the conductive material that covers both sides of the core to reduce the thickness of the conductive material to about 1 micron; applying a film resist to the core; exposing and developing the resist film to form patterns on the conductive material on both sides of the core; and electroplating additional conductive material on the (i) conductive material on both sides of the core (ii) conductive material within the through hole; and (iii) conductive bridge to fill the through hole with conductive material without any voids and to form conductive patterns on both sides of the core.

First claim

The invention claimed is:

1. A method comprising:
electroplating both sides of a core and a through hole of a core with a conductive material in order to cover both sides of the core with the conductive material and to form a conductive bridge in the through hole, wherein the core has a thickness greater than 200 microns;
etching the conductive material that covers both sides of the core to reduce the thickness of the conductive material to about 1 micron;
applying a dry film resist to the core;
exposing and developing the dry resist film to form patterns on the conductive material on both sides of the core; and
electroplating additional conductive material on to (i) the conductive material on both sides of the core (ii) the conductive material within the through hole; and (iii) the conductive bridge in order to fill the through hole with conductive material without any voids and to form conductive patterns on both sides of the core.

2. The method of claim 1 , wherein electroplating both sides of a core and the through hole of a core with a conductive material in order to cover both sides of the core with the conductive material and to form a conductive bridge in the through hole in the core includes electroplating both sides of the core and the through hole of the core with copper.

3. The method of claim 1 , wherein exposing and developing the dry resist film to form patterns on the conductive material on both sides of the core includes forming patterns that have a line spacing less than 25 microns with a line thickness greater than 25 microns.

4. The method of claim 1 , further comprising forming the through hole in the core.

5. The method of claim 4 , wherein forming the through hole in the core includes laser drilling the through hole.

6. The method of claim 1 , further comprising removing the dry resist film.

7. The method of claim 1 , further comprising etching the additional conductive material on both sides of the core in order to form conductive traces on both sides of the core.

8. The method of claim 1 , wherein electroplating additional conductive material on to (i) the conductive patterns on both sides of the core (ii) the conductive material within the through hole; and (iii) the conductive bridge includes orienting the core such that the core is vertical and a longitudinal axis of the through hole is horizontal.

Assignees

• Intel Corp

Inventors

• Boyapati Sri Ranga Sai
• Schuckman Amanda E
• Kandanur Sashi S
• Pietambaram Srinivas
• Hlad Mark
• Darmawikarta Kristof

Classifications

• H05K3/427

  initial plating of through-holes in metal-clad substrates · CPC title

• H05K3/4602

  characterized by a special circuit board as base or central core whereon additional circuit layers are built or additional circuit boards are laminated · CPC title

• H05K3/429

  Plated through-holes specially for multilayer circuits, e.g. having connections to inner circuit layers · CPC title

• C25D3/38

  of copper · CPC title

• H05K3/424 Primary

  by direct electroplating · CPC title