本发明系关于一种镀浴组合物及一种借由无电镀覆将钯层沉积在基板上之方法。根据本发明之含水酸性镀浴包括钯离子源、还原剂、钯离子之氮化错合剂及选自由包括至少两个残基之芳香族化合物组成之群的水溶性稳定剂，其中至少一残基系亲水残基及至少一残基具有负中介效应。该镀浴具有提高之抗不想要分解的稳定性，同时维持充分镀覆速率。

The present invention relates to a plating bath composition and a method for depositing a palladium layer by electroless plating onto a substrate. The aqueous acidic plating bath according to the present invention comprises a source for palladium ions, a reducing agent, a nitrogenated complexing agent for palladium ions and a water-soluble stabilizing agent selected from the group consisting of aromatic compounds comprising at least two residues wherein at least one residue is a hydrophilic residue and at least one residue has a negative mesomeric effect. The plating bath has an increased stability against undesired decomposition while maintaining a sufficient plating rate.