Under Bump Metallurgy (UBM) And Methods Of Forming Same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsWei-Yu Chen, Hsien-Wei Chen, An-Jhih Su, Cheng-Hsien Hsieh
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Abstract
A device package includes a die, fan-out redistribution layers (RDLs) over the die, and an under bump metallurgy (UBM) over the fan-out RDLs. The UBM comprises a conductive pad portion and a trench encircling the conductive pad portion. The device package further includes a connector disposed on the conductive pad portion of the UBM. The fan-out RDLs electrically connect the connector and the UBM to the die.
Claims20
A method for forming a device package, the method comprising:
- forming a seed layer over a die;
- forming a conductive line on the seed layer;
- forming a first mask layer over the conductive line and the seed layer;
- patterning openings in the first mask layer, wherein the openings comprise:
- a first opening for a conductive pad portion of an under bump metallurgy (UBM);
- and
- a second opening for a retaining wall portion of the UBM, wherein the second opening forms a ring around the first opening, and wherein a portion of the first mask layer remains disposed between the first opening and the second opening;
- forming the UBM in the first opening and the second opening, the UBM comprising the conductive pad portion contacting a surface of the conductive line, the UBM further comprising the retaining wall portion having a bottom-most portion physically contacting the conductive line;
- removing the first mask layer;
- and
- mounting a solder ball to the conductive pad portion of the UBM.
A method for forming a device package, the method comprising:
- patterning openings in a mask layer to expose a conductive line, wherein the openings comprise:
- a central opening for a conductive pad portion of an under bump metallurgy (UBM);
- and
- a peripheral opening for a retaining wall portion of the UBM, wherein the peripheral opening forms a ring around the central opening;
- and
- filling the central opening and the peripheral opening with conductive material to form the UBM, wherein the conductive pad portion of the UBM contacts a surface of the conductive line, and wherein the retaining wall portion of the UBM has a bottom-most portion physically contacting the conductive line.
A method for forming a device package, the method comprising:
- forming a redistribution layer (RDL) over a die;
- forming a polymer layer over the RDL, the polymer layer having an opening exposing a portion of the RDL;
- depositing a seed layer over the polymer layer and the RDL, and over sidewalls of the opening;
- forming a conductive line on the seed layer;
- forming a first mask layer having a first opening and a second opening over the conductive line and the seed layer;
- and
- forming an under bump metallurgy (UBM) in the first opening and the second opening, the UBM comprising a conductive pad portion within the first opening, the conductive pad portion contacting a surface of the conductive line, the UBM further comprising a retaining wall portion within the second opening, the retaining wall portion having a bottom-most portion physically contacting the conductive line.
Dependencies are inferred from the claim text.