Hydrogen incorporation and embrittlement of electroformed Au, Cu and Au-Cu

Electroformed Au, Cu, Au-Cu layers and composites display severe brittlenes s in both as plated and heat treated conditions. This phenomenon has not be en considered in the literature previously. In this paper we show the relev ant embrittling phenomenology and explain it with the incorporation of hydr ogen produced in electrochemical side reactions occurring during the format ion of the metallic deposits. Our conclusions were drawn on the basis of th e following experiments: (i) electrochemical measurements-proving the effec t of bath composition on the hydrogen evolution side reaction-(ii) hydrogen removal tests-hot extraction and high vacuum treatmepts-(iii) mass spectro metric identification of released gases, (iv) SEM observations of micrometr ic voids, (v) SAXS measurements of nanometric voids and (vi) SEM fractograp hy of heat treated samples. Hydrogen removal by a high vacuum room temperat ure treatment is proposed. (C) 1999 Elsevier Science Ltd. All rights reserv ed.