Conductor patterned substrate providing stress release during direct attachment of integrated circuit chips

A process for fabricating a patterned circuit for direct attachment to semiconductor devices, such as integrated circuit chips comprising:

• forming in a flexible insulative carrier an aperture having a periphery which is substantially smaller than that of a semiconductor device intended to be located thereover,
• securing a metallic foil to the carrier and removing portions of the foil to form on the insulative carrier a plurality of spaced finger-like leads each extending inwardly to the periphery of the aperture,
• locating over the aperture a semiconductor device having formed on a face thereof metallic contacts, the periphery of the semiconductor device extending beyond the periphery of the aperture and the metallic contacts being registered with the leads,
• simultaneously joining the inner terminations of the leads to the registered metallic contacts on the semiconductor device, and
• severing the leads beyond the device to separate the semiconductor device from the carrier.

A lead frame for direct attachment to at least one semiconductor device, such as an integrated circuit chip having a plurality of terminals arranged in a predetermined pattern upon one face thereof, comprising:

• a continuous elongated web of flexible insulator material;
• a single repetitive pattern of metal having a width less than the width of said insulator material with each repetition of said pattern having a plurality of conductive fingers converging on at least one location;
• an aperture in said insulator material at each said at least one location located centrally of said converging conductive fingers, said central aperture being smaller than the semiconductor device to be bonded to said circuit pattern and defined by at least two slots radiating from a single point in a star burst configuration;
• and
• each said repetition of said metal pattern being bonded to said flexible insulator material.

A process for fabricating a lead frame for direct attachment to semiconductor device, such as integrated circuit chips having a plurality of terminals fixed thereon in a predetermined pattern comprising the steps of:

• forming in a flexible insulative carrier an aperture having a periphery which is substantially smaller than that of a semiconductor device intended to be mounted thereon,
• securing to the insulative carrier a layer of conductive metal having the form of a plurality of spaced finger-like leads each extending substantially radially inwardly to the periphery of the aperture,
• locating over the aperture a semiconductor device having formed on one face thereof a plurality of metallic contacts in fixed predetermined array, the periphery of the semiconductor device extending beyond the periphery of the aperture and the metallic contacts being in registration with the leads,
• simultaneously joining the inner terminations of the leads to the respective registered metallic contacts on the semiconductor device, and
• severing the leads beyond the device to separate an assembly of the semiconductor device and the bonded lead frame from the rest of the carrier.

A circuit pattern for direct attachment to at least one semiconductor device, such as an integrated circuit chip having a plurality of terminals fixed thereon and arranged in a predetermined pattern upon one side of the chip comprising:

• a continuous elongated web of flexible insulator material;
• a single repetitive pattern of metal having a width less than the width of said web of insulator material with each repetition of said pattern having a plurality of conductive fingers converging on at least one location;
• an aperture in said web of insulator material at each said location located centrally of said converging conductive fingers, said aperture being smaller than a semiconductor device to be bonded to said circuit pattern and defined by an opening in said web and a plurality of slots radiating from said opening;
• and
• each said repetition of said metal pattern being bonded to said flexible insulator material.