There is a close relationship between the performance and the heat generation of the electronic device. The heat generation causes a significant degradation of the durability and/or efficiency of the device. It is necessary to develope an effective method to release the generated heat. It is necessary to develop a robust and reliable plating technique of metal layers on commercial substrates with high thermal conductivity, such as alumina (Al2O3), aluminium nitride (AlN), and silicon nitride (Si3N4) in order to meet demands of the printed circuit board (PCB) manufacturing. In this study, an electroless Ni plating technique without sensitization/activation process was developed on the insulating Si3N4 substrate. For surface treatment, OH groups were formed on the surface by using nitric acid. Which provides to increase the number of silane bondings. And the adhesive ability of Ni layer on the Si3N4 substrate improved by using 3-Aminopropyltriethoxysilane (APTES). Next, we formed a Pd-TiO2 adhesion layer to initiate the spontaneous electroless plating. Ni film was deposited on the Pd-TiO2 film by electroless deposition after reducing PdO to Pd using DMAB (Dimethylamine borane). The electrical resistivity of Ni and Cu layers was measured 7.27x10-5 and 1.32x10-6 ohm-cm by four point probe measurement, respectively. The adhesion strength of Ni was 2.49 N by scratch test. The adhesion strength was improved from 2.49N to 3.46N after a thermal shock test possibly due to the removal of hydrogen from Ni-P coating. The thermal resistance of the Si3N4/Pd-TiO2/Ni sample was 0.34W/K, which is similar to the Si3N4/Ni reference sample, indicating that the presence of the TiO2 layer in PCB is negligible in the total heat-dissipation performance.