A structure comprises a plurality of top pads protruding over a top surface of a package substrate, wherein a top pad comprises a first half-circle portion, a second half-circle portion and a first rectangular portion between the first half-circle portion and the second half-circle portion, a plurality of bottom pads embedded in the package substrate, wherein a bottom pad comprises a third half-circle portion, a fourth half-circle portion and a second rectangular portion between the third half-circle portion and the fourth half-circle portion and a plurality of vias coupled between the top pads and their respective bottom pads.

Disclosed are examples of integrated circuit (IC) structures and techniques to fabricate IC structures. Each IC package may include a die (e.g., a flip-chip (FC) die) and one or more die interconnects to electrically couple the die to a substrate. The die interconnect may include a pillar, a wetting barrier on the pillar, and a solder cap on the wetting barrier. The wetting barrier may be wider than the pillar such that during solder reflow, solder wetting of sidewall of the pillar is minimized or prevented all together. The die interconnect may also include a low wetting layer formed on the wetting barrier, which can further mitigate solder wetting problems.

Disclosed are examples of integrated circuit (IC) structures and techniques to fabricate IC structures. Each IC package may include a die (e.g., a flip-chip (FC) die) and one or more die interconnects to electrically couple the die to a substrate. The die interconnect may include a pillar, a wetting barrier on the pillar, and a solder cap on the wetting barrier. The wetting barrier may be wider than the pillar such that during solder reflow, solder wetting of sidewall of the pillar is minimized or prevented all together. The die interconnect may also include a low wetting layer formed on the wetting barrier, which can further mitigate solder wetting problems.

A semiconductor package of a pin-grid-array type includes a bump pad on a first substrate, a metal socket on a second substrate, a core material for reverse reflow on the bump pad, and solder paste or a solder bump forming a solder layer on the core material for reverse reflow. The solder paste or the solder bump is in contact with the bump pad. The core material for reverse reflow and the solder paste or the solder bump bonded to the core material for reverse reflow are used as a pin and detachably attached to the metal socket. The core material for reverse reflow includes a core, a first metal layer directly coated on the core, and a second metal layer directly coated on the first metal layer.

A semiconductor package of a pin-grid-array type includes a bump pad on a first substrate, a metal socket on a second substrate, a core material for reverse reflow on the bump pad, and solder paste or a solder bump forming a solder layer on the core material for reverse reflow. The solder paste or the solder bump is in contact with the bump pad. The core material for reverse reflow and the solder paste or the solder bump bonded to the core material for reverse reflow are used as a pin and detachably attached to the metal socket. The core material for reverse reflow includes a core, a first metal layer directly coated on the core, and a second metal layer directly coated on the first metal layer.

A bonding structure, a package structure, and a method for manufacturing a package structure are provided. The package structure includes a first substrate, a first passivation layer, a first conductive layer, and a first conductive bonding structure. The first passivation layer is disposed on the first substrate and has an upper surface. The first passivation layer and the first substrate define a first cavity. The first conductive layer is disposed in the first cavity and has an upper surface. A portion of the upper surface of the first conductive layer is below the upper surface of the first passivation layer. The first conductive bonding structure is disposed on the first conductive layer.

A bonding structure, a package structure, and a method for manufacturing a package structure are provided. The package structure includes a first substrate, a first passivation layer, a first conductive layer, and a first conductive bonding structure. The first passivation layer is disposed on the first substrate and has an upper surface. The first passivation layer and the first substrate define a first cavity. The first conductive layer is disposed in the first cavity and has an upper surface. A portion of the upper surface of the first conductive layer is below the upper surface of the first passivation layer. The first conductive bonding structure is disposed on the first conductive layer.

Provided is a semiconductor package including a first bump pad on a first substrate, a second bump pad on a second substrate, a core material for reverse reflow between the first bump pad and the second bump pad, and a solder member forming a solder layer on the core material for reverse reflow. The solder member is in contact with the first bump pad and the second bump pad. Each of a first diameter of the first bump pad and a second diameter of the second bump pad is at least about 1.1 times greater than a third diameter of the core material for reverse reflow. The core material for reverse reflow includes a core, a first metal layer directly coated on the core, and a second metal layer directly coated on the first metal layer.

Provided is a semiconductor package including a first bump pad on a first substrate, a second bump pad on a second substrate, a core material for reverse reflow between the first bump pad and the second bump pad, and a solder member forming a solder layer on the core material for reverse reflow. The solder member is in contact with the first bump pad and the second bump pad. Each of a first diameter of the first bump pad and a second diameter of the second bump pad is at least about 1.1 times greater than a third diameter of the core material for reverse reflow. The core material for reverse reflow includes a core, a first metal layer directly coated on the core, and a second metal layer directly coated on the first metal layer.

A bonding structure, a package structure, and a method for manufacturing a package structure are provided. The package structure includes a first substrate, a first passivation layer, a first conductive layer, and a first conductive bonding structure. The first passivation layer is disposed on the first substrate and has an upper surface. The first passivation layer and the first substrate define a first cavity. The first conductive layer is disposed in the first cavity and has an upper surface. A portion of the upper surface of the first conductive layer is below the upper surface of the first passivation layer. The first conductive bonding structure is disposed on the first conductive layer.