Browse Prior Art Database

Process for Producing Plated Microvias with a Barrier Layer

IP.com Disclosure Number: IPCOM000014258D
Original Publication Date: 2001-Apr-20
Included in the Prior Art Database: 2003-Jun-19
Document File: 1 page(s) / 38K

Publishing Venue

IBM

Abstract

Disclosed is an enhanced process for creating microvias for high density interconnect applications, by using thin copper foil as a surface barrier. By utilizing the copper foil as your base layer, one can provide a barrier on the surface to prevent hydrogen, from electroless copper plating, from diffusing into the parts and producing adhesive and cohesive blistering, along with other benefits. Process steps include: 1) Thin copper foil is laminated onto the dielectric material that the microvias are to be formed in. 2) Selective etch the foil to reveal the underlying registration features.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 80% of the total text.

Page 1 of 1

Process for Producing Plated Microvias with a Barrier Layer

   Disclosed is an enhanced process for creating microvias for high density interconnect applications, by using thin copper foil as a surface barrier. By utilizing the copper foil as your base layer, one can provide a barrier on the surface to prevent hydrogen, from electroless copper plating, from diffusing into the parts and producing adhesive and cohesive blistering, along with other benefits.

Process steps include:
1) Thin copper foil is laminated onto the dielectric material that the microvias are to be formed in.
2) Selective etch the foil to reveal the underlying registration features.
3) Cover the parts with photoresist.
4) Use a laser to expose or ablate the resist in the locations where the microvias are to be formed.
5) Etch the copper that is now exposed from the previous step.
6) Lase the dielectric material now exposed through the foil, down to the buried features from prior circuitization.
7) Strip the resist. This removes the resist from the rest of the copper surfaces and removes any surface debris from the dielectric drilling.

The part is now ready for via cleaning (desmear), seeding and electroless copper plate. The remaining copper foil now provides a barrier to significantly reduce any hydrogen penetration into the dielectric, better adhesion to the underlying dielectric, better handling and racking options in the copper electroplate step, and with a better commoning layer in place, higher cur...