Back to results
US 5,719,749 AGranted
Printed circuit assembly with fine pitch flexible printed circuit overlay mounted to printed circuit board
AssigneeSheldahl, Inc.
InventorJahn J. Stopperan
Life of this patent
Estimating the term…
Abstract
A printed circuit assembly includes a fine pitch flexible printed circuit overlay bonded to a normal pitch printed circuit board. The fine pitch flexible printed circuit overlay may provide increased packaging density, direct chip attachment and/or complex routing with a minimal cost impact on the overall printed circuit assembly.
Claims31
A printed circuit assembly comprising:
- (a) a normal pitch printed circuit board having bonding pads arranged into a footprint on a surface thereof;
- (b) a fine pitch flexible printed circuit overlay having bonding pads arranged into a footprint on a surface thereof, wherein the overlay has a minimum pitch of less than about 0.25 mm and at least one through hole with a diameter of less than about 0.3125 mm;
- and
- (c) connecting means for mechanically connecting the overlay to the board and electrically connecting the bonding pads on the overlay to the bonding pads on the board.
1 more element
A printed circuit assembly comprising:
- (a) a normal pitch printed circuit board having bonding pads arranged into a footprint on a surface thereof;
- (b) a fine pitch flexible printed circuit overlay having bonding pads arranged into a footprint on a surface thereof and having a minimum circuit trace pitch of less than about 0.1 mm, the overlay including an adhesiveless laminate including:
- (i) a flexible dielectric substrate;
- (ii) first and second conductive layers of conductive material secured to opposing surfaces of the flexible dielectric substrate through adhesiveless interconnections;
- and
- (iii) at least one metallized through hole defined through the flexible dielectric substrate and having conductive material deposited thereon to electrically interconnect the first and second conductive layers, the metallized through hole having a diameter of less than about 0.15 mm;
- and
- (c) a conductive adhesive layer, interposed between the overlay and the board, for mechanically connecting the overlay to the board and electrically connecting the bonding pads on the overlay to the bonding pads on the board.
5 more elements
Dependencies are inferred from the claim text.