Abstract A package for containing a microwave transistor chip is constructed so that a surface on which the transistor chip is to be mounted is recessed below a metallized surface which serves as an electrical ground. By means of this construction, a mounted transistor chip will be positioned with its top surface just below the plane of the electrical ground surface. Thus, the leads which connect the transistor to the electrical ground surface may be very short, thereby reducing the occurrance of package parasitics, and in particular minimizing the spurious common emitter inductance. According to one embodiment of the invention, a cap is used which is in electrical contact with the electrical ground surface of the package, the cap having a recessed inner portion to assure that no contact is made between the cap and any leads which are bonded to the transistor chip and the package.
A microwave transistor package containing a microwave semiconductor chip and electrical leads connected to said chip comprising: a main body section having an inner slot; a first metallized electrical ground surface in contact with said main body; a second metallized floating electrical contact surface positioned in said inner slot and recessed below said first metallized electrical ground surface; a third metallized mounting surface upon which said microwave semiconductor chip is mounted, the third metallized surface being recessed below the plane of the second metallized electrical floating surface and positioned in said inner slot; and a ground cap which is in electrical contact with the first metallized electrical ground surface, the cap having a recessed inner section for preventing unwanted contact of the cap with the electrical leads in the package.
Claim 2
Dependent Claim
130 words
A microwave transistor package containing a microwave semiconductor chip and electrical leads connected to said chip comprising: a main body section having an inner slot; a first metallized electrical ground surface in contact with said main body; a second metallized floating electrical contact surface positioned in said inner slot and recessed below said first metallized electrical ground surface; a third metallized mounting surface upon which said microwave semiconductor chip is mounted, the third metallized surface being recessed below the plane of the second metallized electrical floating surface and positioned in said inner slot; and a ground cap which is in electrical contact with the first metallized electrical ground surface, the cap having a recessed inner section for preventing unwanted contact of the cap with the electrical leads in the package.
Claim 3
Dependent Claim
44 words
A package as in claim 1 wherein the second metallized surface is recessed below the plane of the first metallized surface by a distance substantially less than the distance by which the third metallized mounting surface is recessed below the first metallized ground surface.
Claim 4
Dependent Claim
26 words
A package as in claim 2 wherein the main body section is constructed of a ceramic material selected from the group consisting of Al2O3 and BeO.