Versatile Si-based packaging with integrated passive components for mmWave applications
View Patent ↗An apparatus is described incorporating an interposer having a cavity for a portion of an antenna structure, having conductor through vias, a top Si part having interconnection wiring and having pads for electrically mounting an integrated circuit chip thereon, wherein the top Si part mates with the interposer electrically and mechanically. The interposer and top Si part may be scaled to provide an array of functional units. The invention overcomes the problem of combining a high efficient antenna with integrated circuit chips in a Si package with signal frequencies from 1 to 100 GHz and the problem of shielding components proximate to the antenna and reduces strain arising from mismatching of TCEs.
1. An apparatus comprising:
an interposer comprising:
a substrate having an upper surface and a lower surface;
a plurality of cavities formed in the upper surface of said interposer; and
conducting through vias from said upper surface to said lower surface, said conducting through vias at said lower surface adapted for coupling to a source of electrical signals and a voltage supply;
an antenna structure embedded in a first of said plurality of cavities;
a flip-chip mounted radio frequency integrated circuit chip embedded in a second of said plurality of cavities;
a top Si part comprising:
an upper layer of high-resistivity Si;
a lower dielectric layer;
a plurality of interconnection wirings formed within said lower dielectric layer;
first pads for electrically connecting said integrated circuit chip to said plurality of interconnection wirings, said first pads comprising micro bumps; and
second pads for connecting said through vias to said plurality of interconnection wirings; and
a micro electro mechanical device positioned on said top Si part and coupled between said integrated circuit and said antenna structure,
wherein said top Si part is mated with said interposer,
wherein said interposer and said top Si part are bonded together to form a perimeter seal around at least said integrated circuit chip,
wherein each of said plurality of cavities has a bottom surface coated with Cu and a plurality of sidewalls coated with Cu,
wherein said integrated circuit chip is capable of receiving RF electrical signals with frequencies in a range from 1 to 100 GHz,
wherein said interposer is selected from the group consisting of Si and quartz,
wherein a thermal coefficient of expansion of said top Si part matches a thermal coefficient of expansion of said interposer,
wherein said antenna comprises two spaced apart electrodes increasing in space therebetween from one end to the other to provide antenna signal propagation away from said spaced apart electrodes where said spacing is greatest in the plane of said electrodes,
wherein said perimeter seal is a metal to metal hermetic seal, and
wherein said perimeter seal extends around the edge of said upper surface of said interposer.
2. The apparatus of claim 1 , wherein said interposer has a thickness between 450 micrometers and 500 micrometers.
3. The apparatus of claim 2 , wherein said through vias comprise tungsten through vias having a diameter between 125 micrometers and 175 micrometers.