Multilayer PC board using polymer thick films
First Claim
1. A multilayer circuit board for mounting and establishing electrical connections between a plurality of electrical components intended for later mounting on the circuit board, said multilayer circuit board comprising in combination:
- a supporting substrate having a copper layer on at least one side etched to form (a) an array of solder pads for receiving the components to be mounted on said circuit board, and (b) conductive tails connected to said solder pads for providing protected electrical connections to said solder pads,a dielectric layer over said copper layer leaving said tails and said pads exposed,conductive polymer traces over said dielectric layer interconnecting selected ones of said tails thereby to form connections between selected ones of said pads,a solder mask over said conductive polymer leaving said pads exposed but covering said tails thereby to shield the polymer, anda solder layer plated onto the exposed solder pads for providing a surface for solder connections to the electrical components.
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0 Petitions
Accused Products
Abstract
A multilayer printed circuit board which reliably and economically marries conventional copper clad printed circuit board technology with polymeric conductors and insulators. Reliability is enhanced by forming all solder pads of copper, providing conductive tails on solder pads which are to be connected by polymeric inks, and ultimately forming a solder resist over all but the solder pads. As a result, polymer inks can be applied to both sides of the board, and the completed board can be subject to conventional solder dipping or wave soldering operations. According to one feature of the invention, a thin dielectric layer can be applied as intermediate to planar conductive layers which form a power plane having built-in distributed capacitance for decoupling.
90 Citations
12 Claims
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1. A multilayer circuit board for mounting and establishing electrical connections between a plurality of electrical components intended for later mounting on the circuit board, said multilayer circuit board comprising in combination:
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a supporting substrate having a copper layer on at least one side etched to form (a) an array of solder pads for receiving the components to be mounted on said circuit board, and (b) conductive tails connected to said solder pads for providing protected electrical connections to said solder pads, a dielectric layer over said copper layer leaving said tails and said pads exposed, conductive polymer traces over said dielectric layer interconnecting selected ones of said tails thereby to form connections between selected ones of said pads, a solder mask over said conductive polymer leaving said pads exposed but covering said tails thereby to shield the polymer, and a solder layer plated onto the exposed solder pads for providing a surface for solder connections to the electrical components. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification