In this paper, we present design, implementation and measurement of 3D mm-wave LTCC (low temperature co-fired ceramic) module with vertical transition through FR-4 PCB substrate. A new structure in order to transfer mm-wave signal from transceiver module through an opening in FR-4 PCB substrate to antenna with standard WR-22 waveguide port is proposed. The module features front-end, receiver and transmitter. The opening in FR-4 PCB substrate is of rectangular type, which has the same dimensions as a WR-22 waveguide. The edge of the opening is conductively plated with copper from top side to the bottom to reduce transmission losses. The implemented module is compact in size (32 x 28 x 3.3 mm ). Experimental results show a 1dB compression output power of 15 dBm and noise figure of 9.72 dB at 40.5~41.5 GHz.