Lead frame for light-emitting diodes

Claim 2

A lead frame strip for light-emitting diodes comprising: a unitary, one piece metal strip having a substantially uniform thickness except in the area of the cavities and containing a plurality of lead pairs in the same longitudinal plane, one lead of each pair having an exposed surface area at one end thereof in a longitudinal plane perpendicular to said longitudinal plane of the remainder of said strip; and an integral reflective cavity formed in each of said surface areas wholly within said one lead extending from said exposed surface area partially into said lead, the exterior walls of said cavity being tapered, the portion of said cavity wall having the largest cross-sectional area being at said one end of said one lead and becoming narrower along said lead in a direction away from said one end, a portion of each of said cavity walls being thicker than the substantially uniform thickness of the remainder of said strip, the outward angle of said walls from the bottom to said surface area being between about 120* and 150* with said bottom, said cavity being adapted to contain a light-emitting diode die.

Claim 3

The lead frame strip of claim 1 further characterized by being fabricated of an alloy of copper and iron.

Claim 4

The lead frame strip of claim 1 further characterized by said strip being punched.

Claim 5

The lead frame strip of claim 1 further characterized by having a thickness between about 10 and 50 mils.

Claim 6

The lead frame strip of claim 1 further characterized by said cavity having a circular aperture at said surface.

Claim 7

The lead frame strip of claim 1 further characterized by said angle of the cavity walls being about 135*.

Claim 8

The lead frame strip of claim 1 further characterized by the addition of a coating of a reflective metal over substantially the entire interior of said cavity.

Claim 9

The lead frame strip of claim 7 further characterized by said coating being a thin layer of gold.

Claim 10

The lead frame strip of claim 8 further characterized by the thickness of said gold layer being between about 50 and 200 microinches.

Claim 11

A combination of lead frame strip and a light-emitting diode mounted in each of a plurality of cavities thereon comprising: a unitary, one piece metal strip having a substantially uniform thickness except in the area of the cavities and containing a plurality of lead pairs in the same longitudinal plane, one lead of each pair having an exposed surface area to one end thereof in a longitudinal plane perpendicular to said longitudinal plane of the remainder of said strip; an integral reflective cavity formed in each of said surface areas wholly within said one lead extending from said exposed surface area partially into said lead, the exterior walls of said cavity being tapered, the portion of said cavity wall having the largest cross-sectional area being at said one end of said one lead and becoming narrower along said lead in a direction away from said one end, a portion of each of said cavity walls being thicker than the substantially uniform thickness of the reMainder of said strip, the outward angle of said walls from the bottom to said surface area being between about 120* and 150* with said bottom; and a light-emitting diode die having two substantially flat surfaces mounted by a first of said flat surfaces in each of said cavities.

Claim 12

A combination of lead frame strip and a light-emitting diode mounted in each of a plurality of cavities thereon comprising: a unitary, one piece metal strip having a substantially uniform thickness except in the area of the cavities and containing a plurality of lead pairs in the same longitudinal plane, one lead of each pair having an exposed surface area to one end thereof in a longitudinal plane perpendicular to said longitudinal plane of the remainder of said strip; an integral reflective cavity formed in each of said surface areas wholly within said one lead extending from said exposed surface area partially into said lead, the exterior walls of said cavity being tapered, the portion of said cavity wall having the largest cross-sectional area being at said one end of said one lead and becoming narrower along said lead in a direction away from said one end, a portion of each of said cavity walls being thicker than the substantially uniform thickness of the reMainder of said strip, the outward angle of said walls from the bottom to said surface area being between about 120* and 150* with said bottom; and a light-emitting diode die having two substantially flat surfaces mounted by a first of said flat surfaces in each of said cavities.

Claim 13

The combination of claim 10 further characterized by the other of said flat surfaces of each of said diode dice being substantially coplanar with said exposed surface area on said lead.

Claim 14

The combination of claim 10 further characterized by a wire extending from the other of said flat surfaces of each of said diode dice to the other lead of said lead pairs.