Multilayer printed circuit board
First Claim
1. A method for fabricating a multilayer printed wiring circuit board comprising:
- a. forming a dielectric layer on a substrate;
b. coating the dielectric layer with a first layer of photosensitive material;
c. selectively exposing the first layer of photosensitive material to form a layer defining a first conductor pattern of exposed photosensitive material;
d. forming the conductor pattern with a conductor material to form conductors in the conductor pattern;
e. coating the circuit bearing layer with a layer of photosensitive substrate material;
f. selectively exposing the layer of photosensitive substrate material to form a second dielectric layer defining circuit layer interconnections;
g. coating the second dielectric layer with a second layer of photosensitive material;
h. selectively exposing the second layer of photosensitive material to form a layer defining a second circuit pattern of exposed photosensitive material;
i. forming the second conductor pattern with electrically conducting material; and
j. repeating steps e through i to form a plurality of electrically
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Accused Products
Abstract
Multilayer printed circuit board is fabricated by coating a suitable substrate, metal, plastic, paper, with a photosensitive coating, exposing the photosensitive coating to form a dielectric thereof, coating the dielectric layer with a coating of a photosensitive chemical solution, selectively imaging and developing the photosensitive coating to form a desired circuit pattern on the dielectric coating, forming a first layer of circuitry by coating the circuit pattern with a conducting material, coating the circuitry bearing layer with a second layer of photosensitive material, selectively exposing and developing the second layer of photosensitive material to form a dielectric with open windows to the first circuit layer, coating the second dielectric layer of the first circuitry with a coating of photosensitive chemical solution, selectively imaging and developing the coating of photosensitive chemical solution to form a circuit pattern and an interconnect pattern and forming a conductor layer of circuitry and interconnects, the interconnect metallization connecting the second circuitry layer with the first circuitry layer, repeating the process to form additional circuitry layers to perform a desired electrical function and forming on the last dielectric layer a metallization such as either a solder mask for circuit terminals or a ground plane and thereafter either retaining the substrate if desired for, for example, a heat sink or additional support or both, or removing the substrate to form a very light weight multilayer printed circuit board.
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Citations
11 Claims
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1. A method for fabricating a multilayer printed wiring circuit board comprising:
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a. forming a dielectric layer on a substrate; b. coating the dielectric layer with a first layer of photosensitive material; c. selectively exposing the first layer of photosensitive material to form a layer defining a first conductor pattern of exposed photosensitive material; d. forming the conductor pattern with a conductor material to form conductors in the conductor pattern; e. coating the circuit bearing layer with a layer of photosensitive substrate material; f. selectively exposing the layer of photosensitive substrate material to form a second dielectric layer defining circuit layer interconnections; g. coating the second dielectric layer with a second layer of photosensitive material; h. selectively exposing the second layer of photosensitive material to form a layer defining a second circuit pattern of exposed photosensitive material; i. forming the second conductor pattern with electrically conducting material; and j. repeating steps e through i to form a plurality of electrically - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification