US 2003/0193081 A1 · Interdigitated leads-over-chip lead frame and device for supporting an integrated circuit die

Abstract

An inventive Leads-Over-Chip (LOC) lead frame includes an assembly of interdigitated leads constructed to overlie double-sided adhesive tape on the front-side surface of an integrated circuit (IC) die. An attachment surface of each lead is adhesively attachable to the tape, and at least some of the leads are constructed to extend across the front-side surface of the die from one edge substantially to another edge, such as an adjacent or opposing edge. As a result, a substantial area of the front-side surface of the die is adhesively attachable to the leads through the tape, so the die is supportable in an IC package in an improved manner, and the heat may be conducted away from the die through the lead frame in an improved manner.

Drawings

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Drawings

Claims7

Dependent claims

An integrated circuit package having an integrated circuit die and portions of a lead frame encapsulated therein for use on a printed circuit board for use in a computer comprising:

an integrated circuit die for use on a printed circuit board for use in a computer, said integrated circuit die having an active surface having a plurality of bond pads thereon, said integrated circuit die having a first edge and an opposing second edge, having at least one bond pad of said plurality of bond pads located on the active surface adjacent the first edge, and having at least one bond pad of said plurality of bond pads located on the active surface adjacent the opposing second edge, said integrated circuit die being encapsulated;
a lead frame for use in connecting said integrated circuit die to circuits of a printed circuit board for use in a computer, said lead frame including a plurality of interdigitated leads for overlying the active surface of the integrated circuit die having a first portion of the plurality of interdigitated leads extending across at least a portion of the active surface from substantially the first edge of the integrated circuit die to substantially the at least one bond pad located adjacent the opposing second edge of the integrated circuit die terminating at a location on the active surface of said integrated circuit die adjacent to and before the at least one bond pad adjacent the opposing second edge of the integrated circuit die and having a second portion of the plurality of interdigitated leads extending across the at least a portion of the active surface from substantially the opposing second edge of the integrated circuit die to substantially the at least one bond pad located adjacent the first edge of the integrated circuit die terminating at a location on the active surface of said integrated circuit die adjacent to and before the at least one bond pad adjacent the first edge of the integrated circuit die, said first portion of the plurality of interdigitated leads being interdigitated with said second portion of the plurality of interdigitated leads, each bond pad of the plurality on the active surface being alternatively for connection using an electrical connector extending only over a portion of the active surface to adjacent leads of the first and second portions of the plurality of interdigitated leads, the first and second portions of the plurality of interdigitated leads each extending to an edge of the piece of tape proximate to the respective said opposing second and first edges of the integrated circuit die, portions of the plurality of interdigitated leads being encapsulated;
and
at least one piece of tape overlying a portion of a front-side surface of said integrated circuit die, said piece of tape located between a portion of said integrated circuit die and a portion of said lead frame for securing said integrated circuit die to said lead frame.

1 more element

An integrated circuit package having an integrated circuit die and a lead frame having a reversible pin-out arrangement for use on a printed circuit board for use in a computer comprising:

a housing having a first side and an opposing second side formed by encapsulation, said housing forming a portion of said integrated circuit package for use on a printed circuit board for use in a computer;
an integrated circuit die located in said integrated circuit package for use on a printed circuit board for use in a computer, said integrated circuit die having an active surface with a plurality of bond pads thereon, having a first edge, and an opposing second edge, at least one bond pad of the plurality of bond pads located adjacent the first edge of the integrated circuit die and at least one bond pad of the plurality of bond pads located adjacent the opposing second edge of the integrated circuit die, said integrated circuit die being located in the housing;
a lead frame for use in said integrated circuit package for use on a printed circuit board for use in a computer, said lead frame having at least portions thereof disposed within the housing and including a plurality of interdigitated leads, each lead of the plurality of interdigitated leads in first and second groups of leads extending substantially from respective said first edge and opposing second edge of the active surface, at least one lead of said first of leads terminating prior to said at least one bond pad of the plurality of bond pads located adjacent the opposing second edge of the integrated circuit die and at least one lead of said second group of leads terminating before said at least one bond pad of the plurality of bond pads located adjacent the first edge of the integrated circuit die, across the active surface, over the respective opposing second edge and first edge of the active surface, away from the integrated circuit die, and out the respective first and opposing second sides of the housing to terminate in a pin, each bond pad of the plurality of bond pads on the front-side surface being alternatively connected by an electrical connection extending over only the active surface to an adjacent lead of the first and second group of leads for alternately accessing each bond pad through pins of the respective first and opposing second sides of the housing, said each lead of the plurality of interdigitated leads in the first and second groups of the leads constructed for extending substantially from the respective first and opposing second edges of the piece of tape proximate to the respective first and opposing second edges of the active surface;
and
at least one piece of tape overlying a portion of said active surface of said integrated circuit die, said piece of tape between a portion of said integrated circuit die and a portion of said lead frame.

2 more elements

An integrated circuit package having an integrated circuit die and a lead frame for use on a printed circuit board for use in a computer comprising:

an integrated circuit die located in said integrated circuit package for use on a printed circuit board for use in a computer, aid integrated circuit die having an active surface having a plurality of bond pads thereon, having a first edge, an opposing second edge, at least one bond pad of the plurality of bond pads located on the active surface adjacent the first edge, and at least one bond pad of the plurality of bond pads located on the active surface adjacent the opposing second edge, said integrated circuit die being encapsulated;
at least one piece of tape for overlying at least a portion of the front-side surface of the integrated circuit die;
and
a lead frame for use in portions of said integrated circuit package for use on a printed circuit board for use in a computer, said lead frame including a plurality of interdigitated leads for overlying at least a portion of the tape and at least a portion of the active surface of the integrated circuit die, a first portion of the plurality of interdigitated leads extending across the front-side surface from the first edge thereof substantially to the opposing second edge thereof terminating on the front-side surface of the integrated circuit die before the at least one bond pad of the plurality of bond pads located adjacent the first edge of the integrated circuit die and a second portion of the plurality of interdigitated leads extending across the front-side surface from the opposing second edge thereof substantially to the first edge thereof terminating on the front-side surface of the integrated circuit die before the at least one bond pad of the plurality located adjacent the opposing second edge, said first portion of the plurality of interdigitated leads being interdigitated with said second portion of leads and each bond pad on the front-side surface being alternatively for connection using an electrical wire connection extending only over the front-side surface to adjacent leads of the first and second portions of the plurality of interdigitated leads, the first portion of the plurality of interdigitated leads for extending across the front-side surface of the integrated circuit die from the first edge thereof substantially to the opposing second edge thereof are for extending to an edge of the tape proximate to the opposing second edge of the front-side surface, portions of the plurality of interdigitated leads being encapsulated.

1 more element

An integrated circuit package having an integrated circuit die and a portion of a lead frame having a reversible pin-out arrangement, said integrated circuit package for use on a printed circuit board for use in a computer, the integrated circuit package comprising:

a housing having a first side and an opposing second side formed by encapsulation, said housing forming a portion of said integrated circuit package for use on a printed circuit board for use in a computer;
a integrated circuit die located in said integrated circuit package for use on a printed circuit board for use in a computer, said integrated circuit die having an active surface with a plurality of bond pads thereon and having a first edge and an opposing second edge, at least one bond pad of the plurality of bond pads on the front-side surface located adjacent the first edge and at least one bond pad of the plurality of bond pads on the active surface located adjacent the opposing second edge, said integrated circuit die located within the housing;
at least one piece of tape overlying a portion of the active surface of the integrated circuit die;
at least a portion of a lead frame supportable by the housing having portions thereof located in said housing forming portions of said integrated circuit package for use on a printed circuit board for use in a computer, said lead frame including a plurality of interdigitated leads overlying at least a portion of the tape and portions of the active surface of the integrated circuit die, each lead in first and second groups of leads of the plurality of interdigitated leads extending substantially from respective said first edge and opposing second edge of the front-side surface and having an end thereof terminating before said at least one bond pad of said plurality of bond pads located adjacent one of said first edge and said opposing second edge of said integrated circuit die, extending over the respective opposing second edge and first edge of the front-side surface of said integrated circuit die, extending away from the integrated circuit die, and extending out the respective first side and opposing second side of the housing to terminate in a pin, at least two bond pads of the plurality of bond pads on the front-side surface being alternately connected to adjacent first and second group leads of the plurality of interdigitated leads for connecting at least two bond pads of the plurality of bond pads located on the active surface of the integrated circuit die being alternatively electrically connected via an electrical connection extending across only portions of the active surface to the plurality of interdigitated leads extending across the front-side surface of the integrated circuit die and accessible through pins on the first and opposing second sides of the housing, said each lead in the first and second groups of the leads of the plurality of interdigitated leads constructed for extending substantially from respective first and second edges of the tape proximate to the respective first and opposing second edges of the front-side surface.

1 more element

Dependencies are inferred from the claim text.

Description5,062 words

Summary2,243 words

#Field of the Invention: The present invention relates to interdigitated leads-over-chip lead frames and other devices and methods for supporting integrated circuit dice.

#State of the Art: Integrated circuit (IC) dice or “chips” are small, generally rectangular IC devices cut from a semiconductor wafer, such as a silicon wafer, on which multiple IC's have been fabricated. Bare IC dice are typically packaged to protect them from corrosion by attaching them to a lead frame for support and heat conduction and then enclosing them in a die package.

#Examples of conventional type lead frames having interdigitized lead frame strips and/or lead fingers thereon are illustrated in U.S. Pat. Nos. 4,949,161 and 5,147,815.

Brief description of the drawings12 figures

#FIG. 1 is an isometric, cut-away view of a prior art integrated circuit (IC) die package having a Leads-Over-Chip (LOC) lead frame;

#FIG. 1A is a top view of a prior art integrated circuit (IC) die package having a Leads-Over-Chip (LOC) lead frame;

#FIG. 1B is a top view of a prior art integrated circuit (IC) die package having a Leads-Over-Chip (LOC) lead frame;

Detailed description2,521 words

#As shown in a cut-away view in FIG. 2, an inventive die package 20 includes a Leads-Over-Chip (LOC) lead frame 22 comprising an assembly of interdigitated leads 24 supported by a housing 26. A portion of each of the leads 24 extends across a front-side surface of an integrated circuit (IC) die 28 from one edge substantially to another, opposing edge in close proximity to adjacent leads 24 and adhesively attached to the front-side surface using double-sided adhesive tape 30 so the leads 24 together support the IC die 28 within the die package 20. Because the leads 24 extend substantially from edge to edge across the front-side surface of the IC die 28 in close proximity to one another, a substantial area of the front-side surface (e.g., 30% to 80% or more) is adhesively attached to the leads 24, so the IC die 28 is supported in an improved manner, and heat is conducted away from the IC die 28 through the lead frame 22 in an improved manner.

#It will be understood by those having skill in the field of this invention that while the die package 20 is shown in FIG. 2 in the form of a Thin Small Outline Package (TSOP), the present invention is equally applicable to any die package including, for example, a Thin Quad Flat Pack (TQFP), a Small Outline J-lead (SOJ) package, a Plastic Leaded Chip Carrier (PLCC), and a Dual In-line Package (DIP). Also, although the leads 24 of the LOC lead frame 22 are shown in FIG. 2 having a particular shape and a particular arrangement with respect to one another, it will be understood that the present invention includes within its scope lead frame leads and other support members having any shape and any arrangement that extend substantially from edge to opposing edge across the front-side surface of an IC die in adhesive attachment therewith.

#Further, it will be understood that the present invention includes within its scope any support members extending across an IC die as described, not just support members, such as the leads 24, that serve as conductors for an IC die. Still further, it will be understood that the IC die 28 may comprise any IC die, and that the double-sided adhesive tape 30 may comprise any adhesive tape for attaching the leads 24 to the front-side surface of the IC die 28. In addition, it will be understood that while all the leads 24 are shown in FIG. 2 extending substantially from edge to edge across the IC die 28, the present invention includes within its scope lead frames in which only some of the leads extend substantially from edge to edge across an IC die.

Interdigitated leads-over-chip lead frame and device for supporting an integrated circuit die

Life of this patent

Interdigitated leads-over-chip lead frame and device for supporting an integrated circuit die

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims7

Description5,062 words

Drawings

Classification9 codes

Life of this patent

Description5,062 words