US4783697A — Leadless chip carrier for RF power transistors or…

Claim 1

Independent Claim 144 words

A leadless chip carrier suitable for a power semiconductor device having a plurality of terminals, said carrier comprising in combination: a substantially planar substrate of insulating material having two major surfaces and a thickness; a conductive pattern on one of said major surfaces having at least a first, second, and third pad for receiving a semiconductive device on one pad thereof; a contact pattern on the other of said major surfaces having at least a first, second, and third area; and distributed interconnecting portions for electrically connecting the first, second, and third pads of the conductive pattern with their associated first, second, and third areas of the contact pattern, whereby said contact pattern permits leadless electrical connection of the chip carrier to accompanying external circuitry, and said distributed interconnecting portions provide wide paths for currents flowing between said conductive pattern and said contact pattern.

Claim 2

Dependent Claim 144 words

A leadless chip carrier suitable for a power semiconductor device having a plurality of terminals, said carrier comprising in combination: a substantially planar substrate of insulating material having two major surfaces and a thickness; a conductive pattern on one of said major surfaces having at least a first, second, and third pad for receiving a semiconductive device on one pad thereof; a contact pattern on the other of said major surfaces having at least a first, second, and third area; and distributed interconnecting portions for electrically connecting the first, second, and third pads of the conductive pattern with their associated first, second, and third areas of the contact pattern, whereby said contact pattern permits leadless electrical connection of the chip carrier to accompanying external circuitry, and said distributed interconnecting portions provide wide paths for currents flowing between said conductive pattern and said contact pattern.

Claim 3

Dependent Claim 15 words

A leadless chip carrier according to claim 1, wherein said substantially planar substrate comprises alumina.

Claim 4

Dependent Claim 15 words

A leadless chip carrier according to claim 1, wherein said substantially planar substrate comprises beryllia.

Claim 5

Dependent Claim 51 words

A leadless chip carrier according to claim 1, wherein said conductive pattern comprises a first major pad having substantial coverage over two opposing side walls of said thickness, and a second and a third pad for substantially covering each of the remaining two opposing side walls of said planar substrate thickness.

Claim 6

Dependent Claim 17 words

The leadless chip carrier according to claim 4, wherein said first pad includes an emitter bridge assembly.

Claim 7

Dependent Claim 38 words

The leadless chip carrier according to claim 1, wherein said conductive pattern first pad includes a space for mounting and electrically connecting a passive component such as a capacitor thereto for providing internal matching to said semiconductor device.

Claim 8

Dependent Claim 24 words

The leadless chip carrier according to claim 1, wherein said conductive pattern includes at least one pad as an island surrounded by another pad.

Claim 9

Dependent Claim 25 words

The leadless chip carrier according to claim 1, wherein said contact pattern comprises a plurality of rectangular areas on the other of said major surfaces.

Claim 10

Dependent Claim 28 words

The leadless chip carrier according to claim 1, wherein said contact pattern comprises one large area approximately in the center, flanked by a plurality of smaller rectangular areas.

Claim 11

Dependent Claim 30 words

The leadless chip carrier according to claim 1, wherein said distributed interconnecting portions comprise wide conductive material wrapped around the thickness along the side walls joining said two major surfaces.

Claim 12

Dependent Claim 20 words

The leadless chip carrier according to claim 1, wherein said distributed interconnecting portions comprise a plurality of individual metallized vias.

Claim 13

Dependent Claim 21 words

The leadless chip carrier according to claim 1, wherein said distributed interconnecting portions comprise a plurality of individual tungsten filled vias.

Claim 14

Dependent Claim 19 words

The leadless chip carrier as defined in claim 1, wherein said conductive pattern includes a material such as gold.

Claim 15

Dependent Claim 18 words

The leadless chip carrier according to claim 1, wherein said contact pattern comprises a material such as gold.

Claim 16

Dependent Claim 47 words

The leadless chip carrier according to claim 1, wherein said carrier is arranged for receiving a transistor die having a collector, a base, and an emitter, and wherein said conductive pattern includes a respective pad for connection to said collector, base, and emitter of the transistor die.

Claim 17

Dependent Claim 177 words

A semiconductor device assembly comprising in combination: a semiconductor device die having a plurality of terminals: a leadless chip carrier including a substantially planar substrate of insulating material with two major surfaces separated by a thickness having four side walls joining said major surfaces, and conductive material on said surfaces including a plurality of separated pads on one of said major surfaces, a plurality of separated contact areas on the other of said major surface, and distributed interconnecting portions connecting said pads to said contact areas; said device die affixed to said one major surface of said carrier and said distributed interconnecting portions providing a wide electrical path between said pads and said contact areas such that any gaps between said distributed interconnecting portions are much less than a given dimension of said pads, whereby said multiple interconnecting portions handle relatively high electrical currents with minimal power loss as well as interconnect said device die terminals to said other major surface contact areas so as to electrically couple by way of leadless surface contacts to external circuitry.

Claim 18

Dependent Claim 177 words

A semiconductor device assembly comprising in combination: a semiconductor device die having a plurality of terminals: a leadless chip carrier including a substantially planar substrate of insulating material with two major surfaces separated by a thickness having four side walls joining said major surfaces, and conductive material on said surfaces including a plurality of separated pads on one of said major surfaces, a plurality of separated contact areas on the other of said major surface, and distributed interconnecting portions connecting said pads to said contact areas; said device die affixed to said one major surface of said carrier and said distributed interconnecting portions providing a wide electrical path between said pads and said contact areas such that any gaps between said distributed interconnecting portions are much less than a given dimension of said pads, whereby said multiple interconnecting portions handle relatively high electrical currents with minimal power loss as well as interconnect said device die terminals to said other major surface contact areas so as to electrically couple by way of leadless surface contacts to external circuitry.

Claim 19

Dependent Claim 52 words

The assembly according to claim 16, wherein said distributed interconnecting portions comprise a plurality of sealed tungsten filled vias extending through the thickness of said planar substrate so as to electrically couple one of said separated conductive pads to a respective one of said separated contact areas along a peripheral dimension thereof.

Claim 20

Dependent Claim 43 words

The assembly according to claim 16, wherein said device die is mounted on one of said conductive pads so as to make electrical contact to a given one terminal of said semiconductor device die so as to eliminate one set of wire bonds.

Claim 21

Dependent Claim 49 words

The assembly according to claim 16, wherein said leadless chip carrier includes distributed interconnecting portions comprising at least one elongated slot therethrough and including conductive material deposited on an inner wall formed by said elongated slot and electrically connecting at least one pad to a respective contact area thereon.

Claim 22

Dependent Claim 18 words

The assembly according to claim 16, wherein said conductive material is a good electrical conductor such as gold.

Claim 23

Dependent Claim 18 words

The assembly according to claim 16, wherein said insulating material is a ceramic such as alumina or beryllia.

Claim 24

Dependent Claim 67 words

The assembly according to claim 16, wherein said carrier accepts a transistor die having multiple similar transistors and wherein said conductive pattern includes a pad having at least one long dimension for connecting said transistors to each of at least three pads a multiple number of times utilizing bond wires to provide a collector, a base, and an emitter contact area on the other major surface thereof.

Claim 25

Dependent Claim 52 words

The assembly according to claim 22, further including a passive component, such as a capacitor mounted on a common pad alternately having emitter or base connections thereto, and including bond wires for connecting between an input pad and said passive component, and a pad alternately having base or emitter connections thereto, respectively.

Claim 26

Dependent Claim 53 words

The assembly according to claim 23, wherein the common pad having emitter connections thereto includes two opposite extremities of said carrier with at least one crossover connected between said extremities for attaching multiple bond wires to said emitter to encourage more uniform current flow thereby allowing a more symmetrical flow of output power.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1991-11-08	1992-05-09	1992-11-08	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1995-11-08	1996-05-09	1996-11-08	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1999-11-08	2000-05-09	2000-11-08	$7700.00	Window Closed / Lapsed

Leadless chip carrier for RF power transistors or the like

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag