Abstract: A multi-pin wafer level chip scale package is achieved. One or more solder pillars and one or more solder blocks are formed on a silicon wafer wherein the one or more solder pillars and the one or more solder blocks all have a top surface in a same horizontal plane. A pillar metal layer underlies the one or more solder pillars and electrically contacts the one or more solder pillars with the silicon wafer through an opening in a polymer layer over a passivation layer. A block metal layer underlies the one or more solder blocks and electrically contacts the one or more solder pillars with the silicon wafer through a plurality of via openings through the polymer layer over the passivation layer wherein the block metal layer is thicker than the pillar metal layer.

Abstract: A multi-pin wafer level chip scale package is achieved. One or more solder pillars and one or more solder blocks are formed on a silicon wafer wherein the one or more solder pillars and the one or more solder blocks all have a top surface in a same horizontal plane. A pillar metal layer underlies the one or more solder pillars and electrically contacts the one or more solder pillars with the silicon wafer through an opening in a polymer layer over a passivation layer. A block metal layer underlies the one or more solder blocks and electrically contacts the one or more solder pillars with the silicon wafer through a plurality of via openings through the polymer layer over the passivation layer wherein the block metal layer is thicker than the pillar metal layer.

Abstract: A multi-pin wafer level chip scale package is achieved. One or more solder pillars and one or more solder blocks are formed on a silicon wafer wherein the one or more solder pillars and the one or more solder blocks all have a top surface in a same horizontal plane. A pillar metal layer underlies the one or more solder pillars and electrically contacts the one or more solder pillars with the silicon wafer through an opening in a polymer layer over a passivation layer. A block metal layer underlies the one or more solder blocks and electrically contacts the one or more solder pillars with the silicon wafer through a plurality of via openings through the polymer layer over the passivation layer wherein the block metal layer is thicker than the pillar metal layer.

Abstract: A multi-pin wafer level chip scale package is achieved. One or more solder pillars and one or more solder blocks are formed on a silicon wafer wherein the one or more solder pillars and the one or more solder blocks all have a top surface in a same horizontal plane. A pillar metal layer underlies the one or more solder pillars and electrically contacts the one or more solder pillars with the silicon wafer through an opening in a polymer layer over a passivation layer. A block metal layer underlies the one or more solder blocks and electrically contacts the one or more solder pillars with the silicon wafer through a plurality of via openings through the polymer layer over the passivation layer wherein the block metal layer is thicker than the pillar metal layer.

Abstract: A wafer level chip scale package is described. The wafer level chip scale package comprises a plurality of redistribution layer (RDL) traces connected to a silicon wafer through openings through a first polymer layer to metal pads on a top surface of the silicon wafer. A plurality of underbump metal (UBM) layers each contact one of the plurality of RDL traces through openings in a second polymer layer over the first polymer layer. A plurality of solder bumps lie on each UBM layer. A metal plating layer lies under the first polymer layer and does not contact any of the plurality of RDL traces. At least one separator lies between at least two of the plurality of RDL traces. The separator is a metal fencing between the two neighboring RDL traces or an air gap between the two neighboring RDL traces.

Abstract: A wafer level chip scale package is described. The wafer level chip scale package comprises a plurality of redistribution layer (RDL) traces connected to a silicon wafer through openings through a first polymer layer to metal pads on a top surface of the silicon wafer. A plurality of underbump metal (UBM) layers each contact one of the plurality of RDL traces through openings in a second polymer layer over the first polymer layer. A plurality of solder bumps lie on each UBM layer. A metal plating layer lies under the first polymer layer and does not contact any of the plurality of RDL traces. At least one separator lies between at least two of the plurality of RDL traces. The separator is a metal fencing between the two neighboring RDL traces or an air gap between the two neighboring RDL traces.

Abstract: A wafer level chip scale package is described. The wafer level chip scale package comprises a plurality of redistribution layer (RDL) traces connected to a silicon wafer through openings through a first polymer layer to metal pads on a top surface of the silicon wafer. A plurality of underbump metal (UBM) layers each contact one of the plurality of RDL traces through openings in a second polymer layer over the first polymer layer. A plurality of solder bumps lie on each UBM layer. A metal plating layer lies under the first polymer layer and does not contact any of the plurality of RDL traces. At least one separator lies between at least two of the plurality of RDL traces. The separator is a metal fencing between the two neighboring RDL traces or an air gap between the two neighboring RDL traces.

Abstract: A wafer level chip scale package is described. The wafer level chip scale package comprises a plurality of redistribution layer (RDL) traces connected to a silicon wafer through openings through a first polymer layer to metal pads on a top surface of the silicon wafer. A plurality of underbump metal (UBM) layers each contact one of the plurality of RDL traces through openings in a second polymer layer over the first polymer layer. A plurality of solder bumps lie on each UBM layer. A metal plating layer lies under the first polymer layer and does not contact any of the plurality of RDL traces. At least one separator lies between at least two of the plurality of RDL traces. The separator is a metal fencing between the two neighboring RDL traces or an air gap between the two neighboring RDL traces.

Abstract: A multi-pin wafer level chip scale package is achieved. One or more solder pillars and one or more solder blocks are formed on a silicon wafer wherein the one or more solder pillars and the one or more solder blocks all have a top surface in a same horizontal plane. A pillar metal layer underlies the one or more solder pillars and electrically contacts the one or more solder pillars with the silicon wafer through an opening in a polymer layer over a passivation layer. A block metal layer underlies the one or more solder blocks and electrically contacts the one or more solder pillars with the silicon wafer through a plurality of via openings through the polymer layer over the passivation layer wherein the block metal layer is thicker than the pillar metal layer.

Abstract: A wafer level chip scale package is described. At least one redistribution layer is connected to a wafer through an opening through a first polymer layer to a metal pad on a top surface of the wafer wherein the redistribution layer has a roughened top surface and wherein holes are formed through the at least one redistribution layer in an area where the redistribution layer has an area exceeding 0.2 mm2. At least one UBM layer contacts the at least one redistribution layer through an opening in a second polymer layer wherein the second polymer layer contacts the first polymer layer within the holes promoting cohesion between the first and second polymer layers and wherein the roughened top surface promotes adhesion between the at least one redistribution layer and the second polymer layer.