Abstract: Package structures and methods for manufacturing the same are provided. The package structure includes a first bump structure formed over a first substrate. The first bump structure includes a first pillar layer formed over the first substrate and a first barrier layer formed over the first pillar layer. In addition, the first barrier layer has a first protruding portion laterally extending outside a first edge of the first pillar layer. The package structure further includes a second bump structure bonded to the first bump structure through a solder joint. In addition, the second bump structure includes a second pillar layer formed over a second substrate and a second barrier layer formed over the second pillar layer. The first protruding portion of the first barrier layer is spaced apart from the solder joint.

Abstract: A method for forming a package structure includes forming an under bump metallization (UBM) layer over a metal pad and forming a photoresist layer over the UBM layer. The method further includes patterning the photoresist layer to form an opening in the photoresist layer. The method also includes forming a first bump structure over the first portion of the UBM layer. The first bump structure includes a first barrier layer over a first pillar layer. The method includes placing a second bump structure over the first bump structure. The second bump structure includes a second barrier layer over a second pillar layer. The method further includes reflowing the first bump structure and the second bump structure to form a solder joint between a first inter intermetallic compound (IMC) and a second IMC.

Abstract: A method for forming a package structure includes forming an under bump metallization (UBM) layer over a metal pad and forming a photoresist layer over the UBM layer. The method further includes patterning the photoresist layer to form an opening in the photoresist layer. The method also includes forming a first bump structure over the first portion of the UBM layer. The first bump structure includes a first barrier layer over a first pillar layer. The method includes placing a second bump structure over the first bump structure. The second bump structure includes a second barrier layer over a second pillar layer. The method further includes reflowing the first bump structure and the second bump structure to form a solder joint between a first inter intermetallic compound (IMC) and a second IMC.

Abstract: A package structure is provided. The package structure includes a first bump structure formed over a substrate, a solder joint formed over the first bump structure and a second bump structure formed over the solder joint. The first bump structure includes a first pillar layer formed over the substrate and a first barrier layer formed over the first pillar layer. The first barrier layer has a first protruding portion which extends away from a sidewall surface of the first pillar layer, and a distance between the sidewall surface of the first pillar layer and a sidewall surface of the first barrier layer is in a range from about 0.5 ?m to about 3 ?m. The second bump structure includes a second barrier layer formed over the solder joint and a second pillar layer formed over the second barrier layer, wherein the second barrier layer has a second protruding portion which extends away from a sidewall surface of the second pillar layer.

Abstract: A package structure is provided. The package structure includes a first bump structure formed over a substrate, a solder joint formed over the first bump structure and a second bump structure formed over the solder joint. The first bump structure includes a first pillar layer formed over the substrate and a first barrier layer formed over the first pillar layer. The first barrier layer has a first protruding portion which extends away from a sidewall surface of the first pillar layer, and a distance between the sidewall surface of the first pillar layer and a sidewall surface of the first barrier layer is in a range from about 0.5 ?m to about 3 ?m. The second bump structure includes a second barrier layer formed over the solder joint and a second pillar layer formed over the second barrier layer, wherein the second barrier layer has a second protruding portion which extends away from a sidewall surface of the second pillar layer.