Direct copper metallization by wet process in the through glass via (TGV)

The seed layer by sputtering or ALD is generally used for the via filling process. After that, the electroplating is done. The vacuum process is high cost process.

At this time, the copper seed layer was made from wet process which is low cost process. After seed layer process, the via was filled with copper by electroplating.

left : glass hole plate right : via filled plate

The hole image of upper picture. and copper seed layer by wet process. the taper angle is a important factor for via filling.