Polymer layer comprising silicone and at least one metal trace and a process of manufacturing the same

• US 8,603,590 B2
• Filed: 10/25/2007
• Issued: 12/10/2013
• Est. Priority Date: 06/07/2006
• Status: Active Grant

• Current Assignee: Cortigent Incorporated, Doheny Eye Institute
• Original Assignee: Second Sight Medical Products, Inc.
• Inventors: Laude, Lucien D., Talbot, Neil Hamilton, Greenberg, Robert J.
• Primary Examiner(s): Padgett, Marianne L
• Application Number:
  US11/924,363
• Publication Number:
  US 20080085376A1
• Time in Patent Office: 2,238 Days
• Field of Search: None
• US Class Current: 427/555
• CPC Class Codes: C23C 18/1608 from pretreatment step, i.e. selective pre-treatment
• CPC Class Codes: C23C 18/1612 through irradiation means
• CPC Class Codes: C23C 18/1653 Two or more layers with at least one layer obtained by electroless plating and one layer obtained by electroplating
• CPC Class Codes: C23C 18/1692 Heat-treatment
• CPC Class Codes: C23C 18/204 Radiation, e.g. UV, laser
• CPC Class Codes: H05K 1/0289 having a matrix lay-out, i.e. having selectively interconnectable sets of X-conductors and Y-conductors in different planes
• CPC Class Codes: H05K 1/032 consisting of one material
• CPC Class Codes: H05K 1/0373 containing additives, e.g. fillers H05K1/036 takes precedence
• CPC Class Codes: H05K 1/0393 Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 2201/0162 Silicon containing polymer, e.g. silicone
• CPC Class Codes: H05K 2201/0209 Inorganic, non-metallic particles
• CPC Class Codes: H05K 2203/016 Temporary inorganic, non-metallic carrier, e.g. for processing or transferring
• CPC Class Codes: H05K 2203/1105 Heating or thermal processing not related to soldering, firing, curing or laminating, e.g. for shaping the substrate or during finish plating
• 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 3/107 by filling grooves in the support with conductive material H05K3/045, H05K3/101, H05K3/1258 and H05K3/465 take precedence
• CPC Class Codes: H05K 3/185 by making a catalytic pattern by photo-imaging
• CPC Class Codes: H05K 3/28 Applying non-metallic protective coatings H05K3/0091 takes precedence; methods for intermediate insulating layers for build-up multilayer circuits H05K3/4673
• CPC Class Codes: H05K 3/4661 Adding a circuit layer by direct wet plating, e.g. electroless plating; insulating materials adapted therefor other insulating materials H05K3/387
• CPC Class Codes: H05K 3/4682 Manufacture of core-less build-up multilayer circuits on a temporary carrier or on a metal foil

Abstract

The invention relates to a method of embedding a metal trace in a silicone containing polymer layer, by the steps of applying an agent that does not adhere to a substrate; applying a polymer layer on the non adhering agent; irradiating a surface of the polymer with a light beam emitted by an excimer laser creating cuts, grooves, blind holes or vias; immersing the irradiated polymer in an autocatalytic bath containing metal ions and metallizing the polymer; thermally treating the metallized polymer layer to induce diffusion of the metalized metal into the first polymer layer; applying a polymer layer on the thermally treated metallized polymer; and thermally treating the metallized polymer.

Claims

1. A method of embedding at least one layer of at least one metal trace in a silicone containing polymer, comprising the steps of:

providing a substrate;

applying an anti-adherent agent that adheres to said substrate;

applying a first silicone containing polymer layer having a surface area on said anti-adherent agent, where said agent adheres less to said first silicone containing polymer layer than said substrate;

first irradiating said surface area of said first silicone containing polymer layer with a first ultraviolet light beam emitted by an excimer laser at a wavelength below 200 nm to ablate said surface area;

creating cuts, grooves, blind holes or vias, having a second surface area formed by said first irradiating below 200 nm with said first ultraviolet light beam;

second irradiating said second surface area of said first silicone containing polymer layer with a second ultraviolet light beam emitted by an excimer laser at a wavelength between 308 and 350 nm;

creating an irradiated surface by said second irradiating between 308 and 350 nm;

immersing said irradiated surface of said first silicone containing polymer layer in an autocatalytic bath containing metal ions of at least one metal and metallizing said irradiated surface area of said first silicone containing polymer layer on said second surface forming metal traces embedded in said first silicone containing polymer layer;

thermally treating said metallized first silicone containing polymer layer to induce diffusion of metal from the metallizing into said first silicone containing polymer layer;

applying a second silicone containing polymer layer on said thermally treated metallized first silicone containing polymer layer forming a first bi-layer silicone containing polymer layer;

thermally treating said first bi-layer silicone containing polymer layer; and

removing said first bi-layer silicone containing polymer layer from said anti-adherent agent on said substrate.

2. The method according to claim 1, further comprising the step of irradiating said surface area of said first silicone containing polymer layer with an ultraviolet light beam having an axis and an intensity that is homogenized by passing said second ultraviolet light beam between 308 and 350 nm through a homogenizing optical system which homogenizes said intensity of said second ultraviolet light beam.

3. The method according to claim 2, further comprising the step of irradiating said surface area of said first silicone containing polymer layer with said second homogenized ultraviolet light beam between 308 and 350 nm that passes through at least one square, rectangular or circular planar mask, disposing said planar mask in a plane perpendicular to said axis of said homogenized ultraviolet light beam, said planar mask being interposed in said homogenized ultraviolet light beam.

4. The method according to claim 1, further comprising a step of immersing said irradiated first silicone containing polymer layer in said autocatalytic bath containing metal ions of at least one metal and metallizing said first silicone containing polymer layer and immersing said metallized first silicone containing polymer layer in said autocatalytic bath containing metal ions, and wherein two or more metal films, each having a thickness, containing said metal ions are separately deposited on said surface area of said first silicone containing polymer layer, and wherein said two or more metal films partially overlap on said surface area.

5. The method according to claim 4, wherein said step of immersing said irradiated first silicone containing polymer layer in a second autocatalytic bath containing second metal ions of at least one metal and metallizing said first silicone containing polymer layer is carrying said first polymer layer by a moving carrier and is delivering said first silicone containing polymer layer to said second autocatalytic bath and is immersing said first silicone containing polymer layer by said moving carrier in said second autocatalytic bath.

6. The method according to claim 4, wherein said step of thermally treating said metallized first silicone containing polymer layer step is placing said metallized first polymer layer in a microwave oven and thermally treating said metallized first silicone containing polymer layer.

7. The method according to claim 4, further comprising the step of immersing said metallized first silicone containing polymer layer into said second autocatalytic bath containing said second metal ions and forming a second bi-layer silicone containing polymer layer which is metallized with two overlapping and different metal films.

8. The method according to claim 1, further comprising the step of applying magnesium fluoride as said anti-adherent agent.