Lsi Logic Corporation

Emily Hawthorne

John Pierre McCormick

An electronic system such as a Board-Level-Product (BLP) includes at least one integrated circuit device which is mounted on a circuit board. Each integrated circuit device includes a thin dielectric substrate bearing a plurality of conductive leads and has a hole circumscribed by the substrate in which is positioned a die having pads that are bonded to ends of leads carried by the substrate and projecting into the hole for contact with the die pads. The leads include free outer ends that project laterally outwardly and downwardly away from the plane of the substrate for connection to contact pads on the circuit board. The free leads are isolated from pressure applied to the chip on tape assembly after it has been connected to a circuit board by means of a thin self-supporting thermally conductive heat spreader that contacts the side of the die opposite its pads and includes fixed standoff and/or alignment pins that extend through alignment holes in the thin substrate and are in physical contact with a surface of the printed circuit board. The arrangement enables transfer of force applied to the heat spreader directly to the circuit board, thereby isolating the die, thin substrate and its fragile free leads from forces applied to the die and/or the heat spreader.

Electronic system including packaged integrated circuits with heat

A Tape-Automated-Bonding (TAB) package includes a resilient polyimide layer that supports a metal leadframe. A microelectronic circuit die is mounted in a hole in the polyimide layer and interconnected with inner leads of the leadframe. The TAB package is adhered to a support member having spacers that abut against the surface of a printed circuit board (PCB) on which the package is to be mounted and provide a predetermined spacing between the leadframe and the surface. Outer leads that protrude from the leadframe are bent into a shape so as extend, in their free state, toward the surface at least as far as the spacers. The package and support member assembly is placed on the PCB surface, and the combination of the weight of the assembly, the resilience of the leads and the preset standoff height enable the leads to resiliently deform so that the spacers abut against the surface and the leads conformably engage with the surface for soldering or other ohmic connection to conjugate bonding pads on the surface. The support member can be formed with lead retainers around which the leads extend to form loops that resiliently and conformably engage with the surface as the assembly is lowered thereon. The support member maintains coplanarity, adds weight to the package, pre-sets the standoff to protect the formed outer leads during surface mounting and enables the package to be shipped without a separate carrier.

Support member for mounting a microelectronic circuit package

Method of mounting microelectronic circuit package

A thin dielectric substrate bearing a plurality of conductive leads has a hole circumscribed by the substrate in which is positioned a die having pads that are bonded to ends of leads carried by the substrate and projecting into the hole for contact with the die pads. The leads include free outer ends that project laterally outwardly and downwardly away from the plane of the substrate for connection to contact pads on a circuit board. The free leads are isolated from pressure applied to the chip on tape assembly after it has been connected to a circuit board by means of a thin self-supporting thermally conductive heat spreader that contacts the side of the die opposite its pads and includes fixed standoff and/or alignment pins that extend through alignment holes in the thin substrate and are in physical contact with a surf ace of the printed circuit board. The arrangement enables transfer of force applied to the heat spreader directly to the circuit board, thereby isolating the die, thin substrate and its fragile free leads from forces applied to the die and/or the heat spreader.

Support assembly for mounting an integrated circuit package on a surface

Method for mounting a microelectronic circuit peripherally-leaded

A thin dielectric substrate bearing a plurality of conductive leads has a hole circumscribed by the substrate in which is positioned a die having pads that are bonded to ends of leads carried by the substrate and projecting into the hole for contact with the die pads. The leads include free outer ends that project laterally outwardly and downwardly away from the plane of the substrate for connection to contact pads on a circuit board. The free leads are isolated from pressure applied to the chip on tape assembly after it has been connected to a circuit board by means of a thin self-supporting thermally conductive heat spreader that contacts the side of the die opposite its pads and includes fixed standoff and/or alignment pins that extend through alignment holes in the thin substrate and are in physical contact with a surface of the printed circuit board. The arrangement enables transfer of force applied to the heat spreader directly to the circuit board, thereby isolating the die, thin substrate and its fragile free leads from forces applied to the die and/or the heat spreader.

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San Francisco, CA, United States of America

Emily Hawthorne