| abstract |
A method of making a semiconductor chip assembly includes providing a metal base that includes a metal plate and a metal layer, providing a routing line that contacts the metal layer and an etch mask that contacts the metal plate, providing a semiconductor chip that includes a conductive pad, mechanically attaching the chip to the routing line, electrically connecting the routing line to the pad, and etching the metal base using a first wet chemical that is selective of the metal plate and then a second wet chemical etch that is selective of the metal layer and the etch mask to form a pillar from an unetched portion of the metal base that contacts the routing line. |