Stackable vertical thin package/plastic molded lead-on-chip memory cube
First Claim
1. A semiconductor package comprising;
- a semiconductor chip having a first major surface with input and output bonding pads thereon, a second major surface substantially parallel to said first major surface and four minor surfaces substantially perpendicular to said major surfaces and joining said major surfaces,a lead frame having a plurality of conductors with distal and proximal ends, the proximal ends of the conductors being positioned adjacent said first major surface of said chip,an insulating layer having a selected thickness positioned between and insulatively bonded to said proximal ends of said conductors and said first major surface,an electrical connection between each respective one of said proximal ends of said conductors and a respective one of each of said bonding pads on the chip,an insulating encapsulation disposed on and substantially enclosing said first major surface, said four minor surfaces, the proximal ends of said conductors and partially enclosing a portion of said distal ends of said conductors, a portion of said distal ends being cantilevered from said encapsulation, anda metallic plate disposed on and in good thermal contact with said second major surface,said plate having a thickness approximately equal to the sum of the thickness of said proximal ends of said lead frame and said insulating layer.
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Accused Products
Abstract
This is a semiconductor chip package configuration particularly suited for stacking. These described arrangement is especially adapted to be used with the so-called Lead-On-Chip type package. Each package is of minimum size, and provided with a thermal heat sink arranged with respect to the remainder of the package to balance the stresses induced in the package during fabrication. This is accomplished by placing a lead frame on the active face of the semiconductor chip, bonding the lead frame conductors to respective input/output pads on the active face of the chip, and molding an encapsulant completely around five of the six sides of the chip but leaving a substantial portion of the sixth side unencapsulated. A heat sink is affixed on the exposed, i.e. unencapsulated, portion of the sixth side of the chip. The heat sink is comprised of a metal capable of thermally conducting and dissipating waste heat away from the chip and is of a mass, thickness, and area to counterbalance stresses such, as bending stresses, introduced into the chip by the application of the lead frame and encapsulant to the chip. The heat sink can also employed as a ground plane to provide an electromagnetic shield when the chips are arranged in a stack.
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Citations
24 Claims
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1. A semiconductor package comprising;
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a semiconductor chip having a first major surface with input and output bonding pads thereon, a second major surface substantially parallel to said first major surface and four minor surfaces substantially perpendicular to said major surfaces and joining said major surfaces, a lead frame having a plurality of conductors with distal and proximal ends, the proximal ends of the conductors being positioned adjacent said first major surface of said chip, an insulating layer having a selected thickness positioned between and insulatively bonded to said proximal ends of said conductors and said first major surface, an electrical connection between each respective one of said proximal ends of said conductors and a respective one of each of said bonding pads on the chip, an insulating encapsulation disposed on and substantially enclosing said first major surface, said four minor surfaces, the proximal ends of said conductors and partially enclosing a portion of said distal ends of said conductors, a portion of said distal ends being cantilevered from said encapsulation, and a metallic plate disposed on and in good thermal contact with said second major surface, said plate having a thickness approximately equal to the sum of the thickness of said proximal ends of said lead frame and said insulating layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A vertical thin package comprising:
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an integrated circuit having an active side, a substantially planar back side, and four edges; a lead frame electrically connected to said front side of said chip, said lead frame terminating in a plurality of lead ends; a molded package encasing (1) said active side and said four edges of said chip, with said back side exposed, and (2) all of said lead frame except said plurality of lead ends, said package having a peripheral edge and a substantially planar first surface that is substantially coplanar with said back side of said chip; a conductive plate thermally attached to said back side of said chip to conduct heat away from said chip via said plate, said plate extending past said peripheral edge of said package and having a substantially uniform thickness over its entire area; and wherein said chip, said lead frame, said molded package and said metallic plate are designed and constructed so that said package has an overall thickness of no more than about 1.27 mm. - View Dependent Claims (15)
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16. A stack of semiconductor chip packages comprising;
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a plurality of semiconductor chip packages, each chip package comprising; a semiconductor chip having a first major surface with input and output bonding pads thereon, a second major surface substantially parallel to said first major surface and four minor surfaces substantially perpendicular to said major surfaces and joining said major surfaces, a lead frame having a plurality of conductors with distal and proximal ends, the proximal ends of the conductors being positioned adjacent said first major surface of said chip, an electrical connection between each respective one of said proximal ends of said conductors and a respective one of each of said bonding pads on the chip, an insulating layer having a selected thickness positioned between and insulatively bonded to said proximal ends of said conductors and said first major surface, an insulating encapsulation disposed on and substantially enclosing said first major surface, said four minor surfaces, the proximal ends of said conductors and partially enclosing a portion of said distal ends of said conductors, a portion of said distal ends being cantilevered from said encapsulation, a metallic plate disposed on and in good thermal contact with said second major surface, and said plate having a thickness substantially equal to the sum of the thickness of said proximal ends of said lead frame and the thickness of said insulating layer, each semiconductor chip package, in said stack, having an adhesive layer disposed on the encapsulation disposed over any said first major surface positioned adjacent the metallic plate on an adjacent chip package. - View Dependent Claims (17, 18, 19, 20)
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21. A stack of semiconductor chip packages comprising:
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a plurality of semiconductor chip packages, each comprising; an integrated circuit having an active side, a substantially planar back side, and four edges; a lead frame electrically connected to said front side of said chip, said lead frame terminating in a plurality of lead ends; a molded package encasing (1) said active side and said four edges of said chip, with said back side exposed, and (2) all of said lead frame except said plurality of lead ends, said package having a peripheral edge and a substantially planar first surface that is substantially coplanar with said back side of said chip; a conductive plate attached to said back side of said chip in a manner permitting heat to be conducted away from said chip via said plate, said plate extending past said peripheral edge of said package and having a substantially uniform thickness over its entire area; and said chip, said lead frame, said molded package and said metallic plate have an overall thickness of no more than about 1.27 mm. - View Dependent Claims (22)
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23. A stack of semiconductor chip packages comprising;
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a plurality of substantially planar semiconductor packages having front surfaces and back surfaces, the front surface of each of said chip packages being bonded to the back surface of any adjacent chip package in said stack by a layer a thermoplastic polyimide adhesive, each of said chip packages comprising; an integrated circuit having an active side, a substantially planar back side, and four edges; a lead frame electrically connected to said front side of said chip, said lead frame terminating in a plurality of lead ends; a molded package encasing (1) said active side and said four edges of said chip, with said back side of said chip exposed, and (2) all of said lead frame except said plurality of lead ends, said package having a peripheral edge and a substantially planar first surface that is substantially coplanar with said back side of said chip; a conductive plate attached to said back side of said chip in a manner permitting heat to be conducted away from said chip via said plate, said plate extending past said peripheral edge of said package and having a substantially uniform thickness over its entire area; and said thermoplastic adhesive has a bonding temperature of about 230 degrees Celsius. - View Dependent Claims (24)
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Specification