The effects of wire and ribbon bond interconnection on the transmission characteristics at millimeter wave frequency range was presented. The insertion loss and return loss was closely related with the ratio of the signal line width to that of bonded wire or ribbon. The most promise condition for low loss interconnection was that the width of bonded wire or ribbon should be compatible to the width of signal lines. In the actual fabrication of LTCC amp module, the insertion loss of packaging is very small which means that the loss due to bonding is nearly negligible. However, the S11 and S22 degraded severely due to the difference of the types of transmission lines between chip and packaging module. A new transition structure was introduced in order to compensate this difference of transmission lines.