| 主权项 |
1. A light emission device, comprising:
an insulating substrate; a semiconductor light emitting element mounted on the insulating substrate; and electrodes and outgoing wirings on the insulating substrate, the electrodes and the outgoing wirings each being for supplying power to the semiconductor light emitting element, each of the electrodes and the outgoing wirings including a first layer on the insulating substrate, each of the electrodes being configured such that a second layer is provided on the first layer, the first layer being provided integrally with the outgoing wirings, the first layer and the outgoing wiring comprising a first conductive material with low electric resistance, the second layer comprising a second conductive material which is harder than the first layer and which has sulfurization resistance to such an extent that secures conduction of said each electrode when a current in a working current range is applied on said each electrode, wherein the second layer comprises AgPd containing 30% or more by weight but 40% or less by weight of Pd; the second layer shielding only a part of the first layer from outside air by covering the part, the part of the first layer forming each of the electrodes, and a part of the outgoing wirings being exposed to the outside air, the part of the outgoing wirings not facing the insulating substrate. |
