Precise direct mounting of laser diode (LD) and photodiode (PD) chips on silica planar lightwave circuits (PLCs) has been investigated for application to transceiver modules. To achieve submicron optical alignment, self-aligned index marks on the PLCs and LDs were directly detected by transmission infrared light. The repeatability of the positioning was measured to be within 0.125 µm. The output power of the resultant module was 0.2 mW at 80 mA. A waveguide-type PD was also mounted in the same way, and module sensitivity of 0.25 A/W was demonstrated.