Electrolytic Copper Plating Process for Glass Substrate

This paper studied the process of filling Through glass via (TGV) in glass substrates with electrolytic copper plating. This process uses a 2 -step plating method. In the first step, Periodic pulse reverse (PPR) plating is used to bridge the center of the TGV to form a blind via hole (BVH) on both sides of the TGV, and in the next second step, the BVH is filled with direct current (DC) plating. Since it is important to bridge the center without voids at the PPR plating step, we evaluated the effects of plating bath composition, PPR plating parameters, and plating equipment on filling performances of PPR plating using THRU-CUP EXP-01, which is an electrolytic copper plating bath. Furthermore, TGV was filled by a two-step process of PPR plating and DC plating, followed by reflow processing 10 times to evaluate its resistance to thermal stress, and the presence of cracks on the glass surface was checked.