Formation of fine pitch traces using ultra-thin PAA modified fully additive process
First Claim
Patent Images
1. A method of manufacturing a flexible substrate comprising:
- providing a flexible dielectric substrate comprising any kind of polyimide (PI), including Kapton PI or Upisel PI, modified PI (MPI), cyclo olefin polymer (COP), or liquid crystal polymer (LCP);
applying an alkaline modification to said dielectric substrate to form a polyamic acid (PAA) anchoring layer on a surface of said dielectric substrate;
electrolessly plating a Ni—
P seed layer on said PAA layer;
forming a photoresist pattern on said Ni—
P seed layer;
plating copper traces within said photoresist pattern;
plating a surface finishing layer on said copper traces; and
removing said photoresist pattern and etching away said Ni—
P seed layer not covered by said copper traces to complete said flexible substrate.
2 Assignments
0 Petitions
Accused Products
Abstract
A method to produce a substrate suitable for diffusion bonding is described. A flexible dielectric substrate is provided. An alkaline modification is applied to the dielectric substrate to form a polyamic acid (PAA) anchoring layer on a surface of the dielectric substrate. A Ni—P seed layer is elecrolessly plated on the PAA layer. Copper traces are plated within a photoresist pattern on the Ni—P seed layer. A surface finishing layer is electrolytically plated on the copper traces. The photoresist pattern and Ni—P seed layer not covered by the copper traces are removed to complete the substrate suitable for diffusion bonding.
-
Citations
20 Claims
-
1. A method of manufacturing a flexible substrate comprising:
-
providing a flexible dielectric substrate comprising any kind of polyimide (PI), including Kapton PI or Upisel PI, modified PI (MPI), cyclo olefin polymer (COP), or liquid crystal polymer (LCP); applying an alkaline modification to said dielectric substrate to form a polyamic acid (PAA) anchoring layer on a surface of said dielectric substrate; electrolessly plating a Ni—
P seed layer on said PAA layer;forming a photoresist pattern on said Ni—
P seed layer;plating copper traces within said photoresist pattern; plating a surface finishing layer on said copper traces; and removing said photoresist pattern and etching away said Ni—
P seed layer not covered by said copper traces to complete said flexible substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A chip on film comprising:
-
a flexible dielectric substrate having a first polyamic acid (PAA) anchoring layer on its top surface; at least one first copper trace on a first Ni—
P seed layer on said first PAA layer and having a surface finishing layer on a top surface of said at least one first copper trace wherein said surface finishing layer comprises electrolytic Ni/Au, electroless Nickel/Immersion gold (ENIG), Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG), electrolytic Palladium, electrolytic Titanium, immersion Tin, electrolytic Tin, electrolytic Rhodium, Electroless Palladium/Autocatalytic Gold (EPAG), or Immersion Gold/Electroless Palladium/Immersion Gold (IGEPIG); andat least one die mounted on said dielectric substrate to said at least one first copper trace. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification