a better understanding of the present invention will be obtained when the following detailed description is read with reference to the drawings . in the drawings like elements are numbered the same , and similar elements are represented by the same number and a different lower case letter suffix . referring now to fig4 , 6 , 7a , 7b and 8 , a semiconductor device assembly 400 is illustrated . the semiconductor device assembly 400 comprises four main parts : a package case 402 , a semiconductor die 404 , a platform 406 , and a package lid 408 . fig4 illustrates the semiconductor device assembly in schematic exploded perspective view . fig5 illustrates the package lid 408 in schematic bottom view . fig6 illustrates the package case 402 , the semiconductor die 404 , and the platform 406 in schematic top view . fig7 a illustrates the package lid 408 in schematic elevational cross section ( taken along line 7a -- 7a of fig5 ). fig7 b illustrates the package case 402 , the semiconductor die 404 , and the platform 406 in schematic elevational cross section ( taken along line 7b -- 7b of fig6 ). fig8 illustrates the semiconductor device assembly 400 in schematic elevational cross section after the package lid 408 in fig7 a is attached and electrically connected to the package case 402 and the platform 406 in fig7 b . the package case 402 has a die receiving cavity 410 surrounded by one or more tiers 412 of bond fingers 414 ( partially illustrated for clarity ), which is further surrounded by one or more conductive case pattern ( s ) 416 . preferably the die receiving cavity 410 is centrally located in the package case 402 . the bond fingers 414 and the conductive case pattern ( s ) 416 are respectively connected to external connectors 702 ( illustrated in fig7 a , 7b and 8 ) such as pins , solder ball bumps or the like by way of vias 704 ( illustrated in fig7 a , 7b and 8 ), traces or the like . the one or more conductive case pattern ( s ) 416 are preferably plated metalizations or the like , and most preferably metalizations plated with copper alloys or gold alloys . the package case 402 may be fabricated from ceramic materials , pcb materials , epoxy laminates or the like . the semiconductor die 404 has an attachment face 706 , an active face 418 , a platform receiving area 420 located on the active face 418 , preferably centrally located on the active face 418 , and a plurality of bond pads 422 located peripherally on the active face 418 . the semiconductor die attachment face 706 may be attached in the die receiving cavity 410 . the platform 406 has an attachment surface 708 and a substantially coplanar surface 424 with one or more conductive platform pattern ( s ) 426 . the platform attachment surface 708 is fixedly attached to the semiconductor die 404 in the platform receiving area 420 , preferably by means of epoxy 710 or the like . the one or more conductive platform pattern ( s ) 426 are preferably plated metalizations or the like , and most preferably metalizations plated with copper alloys or gold alloys . the platform 406 may be fabricated from ceramic materials , pcb materials , epoxy laminates or the like . the platform 406 may be fabricated from the same or different materials as the package case 402 . one or more of the semiconductor die bond pad ( s ) 422 are selectively connected to the conductive platform pattern ( s ) 426 by electrical conductors 428a , and the other die bond pads 422 are selectively connected on a one to one basis to the package case bond fingers 414 by electrical conductors 428b . the electrical conductors 428a and 428b may be formed with wire bonding , tape automated bonding or the like . the package lid 408 has a lid surface 716 , a platform attachment area 432 , a case attachment area 434 and one or more conductive lid pattern ( s ) 436 . the platform attachment area 432 is located on the lid surface 716 , and preferably is centrally located on the lid surface 716 . the case attachment area 434 is peripherally located on the lid surface 716 and surrounds the platform attachment area 432 . the one or more conductive lid pattern ( s ) 436 are disposed on the lid surface 716 and are partially located in the platform attachment area 432 and partially located in the case attachment area 434 , each conductive lid pattern 436 contiguously electrically connecting a portion of the platform attachment area 432 to the case attachment area 434 . the one or more conductive lid pattern ( s ) 436 are preferably plated metalizations or the like , and most preferably metalizations plated with copper alloys or gold alloys . the package lid 408 may be fabricated from ceramic materials , pcb materials , epoxy laminates or the like . the package lid 408 may be fabricated from the same or different materials as the package case 402 and / or the platform 406 . the lid surface 716 and the one or more conductive lid pattern ( s ) 436 encloses the die receiving cavity 410 without electrically or mechanically contacting the semiconductor die 404 , the bond fingers 414 , or the electrical conductors 428a and 428b therebetween . the one or more conductive lid pattern ( s ) 436 in the platform attachment area 432 are electrically connected to the respective one or more conductive platform pattern ( s ) 426 . the one or more conductive lid pattern ( s ) 436 in the case attachment area 434 are electrically connected to the respective one or more conductive case patterns 416 , thus completing the electrical connection ( s ) between the one or more semiconductor bond pads 422 connected to the platform pattern ( s ) 426 and the one or more external connectors 702 connected to the case pattern ( s ) 416 . the one or more conductive lid pattern ( s ) 436 may be electrically connected to the one or more conductive platform pattern ( s ) 426 by pressure contact , reflowed solder , conductive epoxy or the like , preferably by conductive epoxy 802 as illustrated in fig8 . the one or more conductive lid pattern ( s ) 436 may be electrically connected to the one or more case pattern ( s ) 416 by reflowed solder , conductive epoxy or the like , preferably by conductive epoxy 804 as illustrated in fig8 . the electrical connections between the conductive lid pattern ( s ) 436 and conductive platform pattern ( s ) 426 may be the same or different from the electrical connections between the conductive lid pattern ( s ) 436 and the conductive case pattern ( s ) 416 . the case attachment area 434 ( of the package lid 408 ) is attached to the package case 402 so as to form a hermetic seal which isolates and protects the die receiving cavity , and all items contained therein , from environmental and mechanical harm . preferably , the electrical connections ( such as the conductive epoxy 804 ) between the lid patterns 436 and the case patterns 416 also form the seal between the package lid 408 and package case 402 . referring now to fig7 a , 7b and 8 an aspect of the present invention is illustrated . here the external connectors 702 on the package case 402 are in a cavity up configuration , wherein the external connectors 702 are located on an exterior face 712 of the package case 402 opposite the interior face 714 defining the die receiving cavity 410 . referring to fig7 a , 7b and 8 another aspect of the present invention is illustrated . here the lid surface 716 is contoured so that the platform attachment area 432 and the case attachment area 434 are projected out of the plane of the package lid so that the conductive lid pattern ( s ) 436 are nonplanar . the conductive platform pattern ( s ) 426 are substantially planar , the conductive case pattern ( s ) 416 are substantially planar , and the conductive platform pattern ( s ) 426 and the conductive case pattern ( s ) 416 are substantially coplanar , thereby facilitating the connection of the conductive lid pattern ( s ) 436 to the conductive platform pattern ( s ) 426 and the conductive case pattern ( s ) 416 . referring now to fig9 another aspect of the invention is illustrated in a cross - section elevational view . here the package lid 908 , the lid surface 910 and the conductive lid pattern ( s ) 936 are substantially planar , and the platform 906 has a contoured surface 938 . a central portion 940 of the contoured surface 938 is projected out of the plane of the platform 906 so that the conductive platform pattern ( s ) 926 are nonplanar . the conductive case pattern ( s ) 916 and the central portion 940 of the conductive platform pattern ( s ) 926 are in substantially the same plane , thereby facilitating the connection of the conductive lid pattern ( s ) 936 to the conductive platform pattern ( s ) 926 and the conductive case pattern ( s ) 916 . referring now to fig1 , another aspect of the invention is illustrated in schematic cross - section elevational view . here the platform 1006 and / or the package lid 1008 are fabricated from an electrically conductive metal , such as aluminum , copper , gold or the like . the conductive case pattern 1016 consists of a single case pattern . referring now to fig1 , 12 , 13a , 13b and 14 , another embodiment of the present invention is illustrated . here two distinct sets of semiconductor bond pads may be connected to at least two distinct external connectors on the package case by way of the package lid . in this embodiment one set of bond pads may be selectively connected to an external ground , power source , or signal channel by way of one or more external connectors , and another set of bond pads may be selectively connected to another external ground , power source , or signal channel by way of one or more other external connectors . fig1 illustrates in schematic bottom view the package lid 408 of fig4 having two conductive lid patterns 1136a and 1136b . fig1 illustrates in schematic top view the package case 402 having two conductive case patterns 1216a and 1216b , the semiconductor die 404 , and the platform 406 of fig4 having two conductive platform patterns 1226a and 1226b . fig1 a illustrates the package lid 408 in schematic elevational cross section ( taken along line 13a -- 13a of fig1 ). fig1 b illustrates the package case 402 , the semiconductor die 404 , and the platform 406 in schematic elevational cross section ( taken along line 13b -- 13b of fig1 ). fig1 illustrates the semiconductor device assembly 1400 in schematic cross section after the package lid 408 in fig1 a is attached and electrically connected to the package case 402 and the platform 406 in fig1 b . the two conductive case pattern ( s ) 1216a and 1216b are electrically isolated from one another . the case patterns 1216a and 1216b are connected by vias 1204a and 1204b , respectively ( illustrated in fig1 , 13b and 14 ), traces or the like , to external connectors 1302a and 1302b ( illustrated in fig1 b and 14 ) such as pins , solder ball bumps or the like . the two conductive platform patterns 1226a and 1226b ( illustrated in fig1 , 13b and 14 ) are electrically isolated from one another . one or more of the semiconductor die bond pad ( s ) 1222a are selectively connected to the conductive platform pattern ( s ) 1226a by electrical conductors 1228a illustrated in fig1 , 13b and 14 ), one or more of the semiconductor die bond pad ( s ) 1222b are selectively connected to the conductive platform pattern ( s ) 1226b by electrical conductors 1228b ( illustrated in fig1 , 13b and 14 ), and the remaining other die bond pads 1222c are selectively electrically connected on a one to one basis to the package case bond fingers 414 by electrical conductors 1228c . the bond fingers are further connected to external connectors 702 . the electrical conductors 1228a , 1228b and 1228c may be formed with bond wires , tape automated bonding or the like . the two conductive lid pattern ( s ) 1136a and 1136b ( illustrated in fig1 , 13a and 14 ) are electrically isolated from one another . the two conductive lid pattern ( s ) 1136a and 1136b are disposed on the lid surface 716 and are partially located in the platform attachment area 432 and partially located in the case attachment area 434 , each conductive lid pattern 1136a and 1136b contiguously electrically connecting a portion of the platform attachment area 432 to the case attachment area 434 . referring now to fig1 , the lid surface 716 and the two conductive lid patterns 1136a and 1136b enclose the die receiving cavity 410 without electrically or mechanically contacting the semiconductor die 404 , the bond fingers 414 , or the electrical conductors 1228a , 1228b and 1228c therebetween . the two conductive lid patterns 1136a and 1136b in the platform attachment area 432 are electrically connected to the respective two conductive platform patterns 1226a and 1226b . the two conductive lid pattern ( s ) 1136a and 1136b in the case attachment area 434 are electrically connected to the respective two conductive case patterns 1216a and 1216b , thereby completing the electrical connection ( s ) between the one or more semiconductor bond pads 1222a and 1222b respectively connected to the platform pattern ( s ) 1226a and 1226b and the one or more external connectors 1302a and 1302b respectively connected to the case pattern ( s ) 1216a and 1216b . the two conductive lid patterns 1136a and 1136b may be electrically connected to the respective two conductive platform patterns 1226a and 1226b by pressure contact , reflowed solder , conductive epoxy or the like , preferably by conductive epoxy 1402a and 1402b as illustrated in fig1 . the two conductive lid patterns 1136a and 1136b may be electrically connected to the two case patterns 1216a and 1216b by reflowed solder , conductive epoxy or the like , preferably by conductive epoxy 1404a and 1404b as illustrated in fig1 . the case attachment area 434 ( of the package lid 408 ) is attached to the package case 402 so as to form a hermetic seal which isolates and protects the die receiving cavity 410 , and all items contained therein , from environmental and mechanical harm . preferably , the electrical connections ( such as the conductive epoxy 1404a ) between the lid pattern 1136a and the case patterns 1216a also form the seal between the package lid 408 and package case 402 . referring now to fig1 , another embodiment of the present invention is illustrated in schematic cross - section elevational view . here the semiconductor device assembly 1500 is in a cavity down configuration , wherein the external connectors 1502 for the bond fingers 414 and the one or more conductive case pattern ( s ) 416 are located on the same face 1504 of the package case 1506 which also defines the die receiving cavity 410 . referring now to fig1 , another embodiment of the present invention is illustrated in schematic cross - section elevational view . here the semiconductor device assembly 1600 is also in a cavity down configuration . unlike the semiconductor device assembly 1500 illustrated in fig1 , the semiconductor device assembly 1600 has one or more external lead connectors 1632 on the exterior surface of the package lid 1608 . here one or more semiconductor die bond pads 1622 are connected to the one or more conductive platform patterns 1626 by electrical conductors 1628a , and the other remaining semiconductor die bond pads 1622 are connected to the package case bond fingers 1614 by electrical conductors 1628b . the bond fingers 1614 are further connected to external case connectors 1630 by package case vias 1616 or the like . the external case connectors 1630 surround the periphery of the package case face 1604 which defines the die receiving cavity . the package lid 1608 has one or more conductive lid patterns 1636 on the side opposite the external lid connectors 1632 . the conductive lid patterns 1636 are connected to the external lid patterns 1632 by one or more vias 1640 which pass through the package lid 1608 . the conductive lid patterns 1636 are connected to the conductive platform patterns by pressure contact , reflowed solder , conductive epoxy or the like , preferably by conductive epoxy 1638 . the package lid 1608 is attached to the package case 1602 , preferably by a nonconductive epoxy 1642 . the external lid connectors 1632 and the external case connectors 1630 are oriented to face the same direction , and preferably terminate in substantially the same plane . other and further objects , features and advantages will be apparent from the following description of the presently preferred embodiments of the invention , given for the purpose of disclosure and taken in conjunction with the accompanying drawings . the present invention , therefore , is well adapted to carry out the objects and attain the ends and advantages mentioned , as well as others inherent therein . while presently preferred and most preferred embodiments of the invention have been given for purposes of disclosure , numerous changes in the details of construction , interconnection and arrangement of parts will readily suggest themselves to those skilled in the art and which are encompassed within the spirit of the invention and the scope of the appended claims .