Millimeter-wave Ltcc Packaging Technology Research

The millimeter wave multi-chip module (MCM) is attributed the technology of hybrid integrated circuit, and it can effectively decrease systemic volume and weight. Through implementing the package of bare die, the reliability and adaptability of the MCM are enhanced.In this dissertation, based on the LTCC technology, the important millimeter wave MCM are achieved with applying the parallel seam welding technique, and then the crucial techniques of the LTCC in the applications of the millimeter wave MCM are investigated. The dominating works of this dissertation are as follows:1. The millimeter wave MCM with the LTCC encapsulation: The steady millimeter wave MCM is realized by using the technologies of the LTCC multi-layer board, the parallel seam welding, and the shell of the cutoff shielding cavity. For the packaged MCM, the gain is exceeded 30dB, the flatness is±2dB, and the noise coefficient is under 3.7.2. RF through-wall interconnecting in the millimeter wave frequency band: the RF signal needs to be elicited from the metal shielding shell in order to resolve the problem of the millimeter wave MCM encapsulation. In this dissertation, the LTCC multi-layer board is used as the circuit board in the packaging shell, the top layer of the LTCC multi-layer board is seen as the sealing base of metal frame, and the shielding wall of the packaging shell is shaped via the holes. The RF signal is elicited from the packaging shell by using the method of microstrip-strip-line-microstrip transition. The loss of single through-wall interconnecting is under 0.4dB and 0.8dB, and the return loss is exceeded 10dB and 7dB in 30~34GHz and 36.30~38GHz, respectively.3. The layer vertical interconnecting of the LTCC multi-layer board: The vertical interconnecting models are created based on the three approaches of the impedance matching, mode matching, and HFSS simulation. All simulated results about the MS-VIA-CPW, CPW-VIA-CPW, and MS-VIA-CPW are compared with those of experiment, good agreements are obtained. 4. The shell of un-resonator shielding cavity: The size of the packaging shielding shell is designed by using the resonator theory of the medium-loaded metal cavity. Based on HFSS model, the HMIC connecting to RF input and output in the interior of the packaging shell is substituted by the 50ohm micro-strip-line. Through simulated analysis, it is shown that the resonator frequency of the packaging shielding cavity is out the operating frequency. Finally, the HMIC connecting to RF input and output in the interior of the packaging shell is substituted by the 50ohm microstrip-line. The isolation of the input and output of the packaging shell is validated by using 50ohm load replacing to HMIC. With these means, it can let the isolation exceed the amplifier total gain and let the amplifier work steadily.