Multi-layer circuit board and semiconductor flip chip connection
First Claim
1. A circuit comprising:
- a multi-layer circuit board including a substrate having a top face and conductive traces extending through its volume between differing layers, and a series of holes extending from a surface of the circuit board into its volume a sufficient length through one or more of said layers to expose a portion of said conductive traces associated therewith, wherein said conductive traces include signal transmission lines and ground lines configured so as to provide a desired characteristic impedance in selected signal transmission lines and said holes are precisely located to achieve said desired characteristic impedance through the selected signal transmission lines so as to provide predetermined signal transmission performance for microwave or millimeter wave frequencies, wherein said multi-layer circuit board comprises a cofired ceramic substrate having a plurality of dielectric layers which separate the signal transmission lines from the ground via controlled thickness of said dielectric layers;
a conductive material in each of said series of holes and contacting the exposed portion of the conductive traces;
a semiconductor flip chip having a series of metallic bumps extending from input-output pads and connected to circuitry on the chip and extending into said holes, the metallic bumps being in contact with said conductive material thereby making electrical connection to the traces via said conductive material; and
at least one cavity formed through one or more layers of said board, said cavity having edges adjacent said holes and a volume beneath said chip for providing an air gap with a selected thickness for protecting circuitry on said chip and further improving high frequency signal operations.
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Accused Products
Abstract
A multi-layer circuit board (11) has a cofired ceramic with a configuration of circuit traces (27) extending though differing layers of the multi-layer circuit board (11) to facilitate mountable conductive contact with semiconductor flip chips (13). Via holes (23) are precisely formed in the multi-layer circuit board (11) and are filled with solder or conductive epoxy. Semiconductor chips (13) have an array of metallic posts (19) alignable with the holes (23) and are mounted upon the upper surface of the multi-layer circuit board (11) in plug fashion. An aperture (25) may be formed in multi-layer circuit board (11) directly below each semiconductor chip (13) for protection of the circuitry on semiconductor chip (13) from contact with multi-layer circuit board (11). The via holes (23) and transmission line structure of the circuit board (11) are precisely formed to achieve a desired characteristic impedance.
219 Citations
21 Claims
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1. A circuit comprising:
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a multi-layer circuit board including a substrate having a top face and conductive traces extending through its volume between differing layers, and a series of holes extending from a surface of the circuit board into its volume a sufficient length through one or more of said layers to expose a portion of said conductive traces associated therewith, wherein said conductive traces include signal transmission lines and ground lines configured so as to provide a desired characteristic impedance in selected signal transmission lines and said holes are precisely located to achieve said desired characteristic impedance through the selected signal transmission lines so as to provide predetermined signal transmission performance for microwave or millimeter wave frequencies, wherein said multi-layer circuit board comprises a cofired ceramic substrate having a plurality of dielectric layers which separate the signal transmission lines from the ground via controlled thickness of said dielectric layers; a conductive material in each of said series of holes and contacting the exposed portion of the conductive traces; a semiconductor flip chip having a series of metallic bumps extending from input-output pads and connected to circuitry on the chip and extending into said holes, the metallic bumps being in contact with said conductive material thereby making electrical connection to the traces via said conductive material; and at least one cavity formed through one or more layers of said board, said cavity having edges adjacent said holes and a volume beneath said chip for providing an air gap with a selected thickness for protecting circuitry on said chip and further improving high frequency signal operations. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A microwave/millimeter wave semiconductor flip chip to circuit board circuit comprising:
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a multi-layer circuit board including a cofired ceramic substrate having a plurality of dielectric layers and conductive traces extending through its volume and between differing dielectric layers of the multi-layer circuit board, and a series of holes extending from a top surface of the circuit board into its volume a sufficient length through one or more of said layers to expose a portion of the conductive traces providing signal transmission lines and ground lines, and wherein said holes may extend to differing levels within the multi-layer circuit board to facilitate routing of said conductive traces; a conductive filler material disposed in each of said series of holes and which contacts the exposed portion of the conductive traces thereby forming an electrical connection therewith; a semiconductor flip chip having a series of metallic bumps extending from input-output pads thereon and having circuitry for operating with signals having frequencies in the microwave or millimeter wave range, said series of metallic bumps partially extending directly into said series of holes of said circuit board such that the metallic bumps contact the conductive material thereby making electrical connection to the conductive traces and at least one cavity formed through one or more layers of said board, said cavity having edges adjacent said holes and a volume beneath said chip for providing an air gap with a selected thickness for protecting circuitry on said chip and further improving high frequency signal operations; wherein select signal transmission lines are arranged relative to said ground lines so as to achieve a desired characteristic impedance. - View Dependent Claims (18, 19, 20, 21)
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Specification