Impedance matching between a bare-die integrated circuit and a transmission line on a laminated PCB

摘要

A system for matching impedances of a bare-die Integrated Circuit and bonding wires. A bare-die Integrated Circuit is configured to output or input, at an impedance of Z3, a millimeter-wave signal from three electrically conductive contacts. Three electrically conductive pads, printed on one of the laminas of a Printed Circuit Board (PCB) are connected to the three electrically conductive contacts via three bonding wires respectively, the bonding wires have a characteristic impedance of Z1, wherein Z1>Z3. One of the electrically conductive pads extends to form a transmission line signal trace of length L, the transmission line signal trace having a first width resulting in characteristic impedance of Z2, wherein Z2>Z3. The transmission line signal trace widens to a second width, higher than the first width, after the length of L, decreasing the characteristic impedance of the transmission line signal trace to substantially Z3 after the length L and onwards.

主权项

1. A system configured to match impedances of a bare-die Integrated Circuit and bonding wires, comprising:
a bare-die Integrated Circuit or a heightened bare-die Integrated Circuit, configured to output or input, at an impedance of Z3, a millimeter-wave signal from three electrically conductive contacts arranged in a ground-signal-ground configuration on an upper side edge of the bare-die Integrated Circuit; the spacing between a center point of the electrically conductive contact for the signal to each center points of the electrically conductive contacts of the ground is between 100 and 250 microns; three electrically conductive pads, printed on a particular one of at least one lamina of a Printed Circuit Board (PCB), arranged in a ground-signal-ground configuration alongside the upper side edge of the bare-die Integrated Circuit, and connected to the three electrically conductive contacts via three bonding wires respectively, the bonding wires having a characteristic impedance of Z1, wherein Z1>Z3; the electrically conductive pad for the signal extends to form a transmission line signal trace of length L, the transmission line signal trace having a first width resulting in characteristic impedance of Z2, wherein Z2>Z3; and the transmission line signal trace widens to a second width, greater than the first width, after the length of L, operative to decrease the characteristic impedance of the transmission line signal trace to substantially Z3 after the length L and onwards, where Z3 is at most 70% of Z2 and Z3 is at most 70% of Z1; the system configured to match an impedance seen by the bare-die Integrated Circuit at the electrically conductive contacts with the impedance Z3, by determining a specific L that results in one half wavelength of the millimeter-wave signal to extend between the electrically conductive contacts and the point where the transmission line signal trace widens.