An embodiment bump on trace (BOT) structure includes a contact element supported by an integrated circuit, an under bump metallurgy (UBM) feature electrically coupled to the contact element, a metal ladder bump mounted on the under bump metallurgy feature, the metal ladder bump having a first tapering profile, and a substrate trace mounted on a substrate, the substrate trace having a second tapering profile and coupled to the metal ladder bump through direct metal-to-metal bonding. An embodiment chip-to-chip structure may be fabricated in a similar fashion.

A conductive interconnect structure includes a contact pad; a conductive body connected to the contact pad at a first end; and a conductive layer positioned on a second end of the conductive body. The conductive body has a longitudinal direction perpendicular to a surface of the contact pad. The conductive body has an average grain size (a) on a cross sectional plane (Plane A) whose normal is perpendicular to the longitudinal direction of the conductive body. The conductive layer has an average grain size (b) on Plane A. The conductive body and the conductive layer are composed of same material, and the average grain size (a) is greater than the average grain size (b).

In a described example, a device includes an overcoat layer covering an interconnect; an opening in the overcoat layer exposing a portion of a surface of the interconnect; a stud on the exposed portion of the surface of the interconnect in the opening; a surface of the stud approximately coplanar with a surface of the overcoat layer; and a conductive pillar covering the stud and covering a portion of the overcoat layer surrounding the stud, the conductive pillar having a planar and un-dished surface facing away from the stud and the overcoat layer.

A semiconductor device includes a substrate having a plurality of pads on a surface of the substrate, a semiconductor chip that includes a plurality of metal bumps connected to corresponding pads on the substrate, a first resin layer between the surface of the substrate and the semiconductor chip, a second resin layer between the substrate and the semiconductor chip and between the first resin layer and at least one of the metal bumps, and a third resin layer on the substrate and above the semiconductor chip.

An embodiment bump on trace (BOT) structure includes a contact element supported by an integrated circuit, an under bump metallurgy (UBM) feature electrically coupled to the contact element, a metal ladder bump mounted on the under bump metallurgy feature, the metal ladder bump having a first tapering profile, and a substrate trace mounted on a substrate, the substrate trace having a second tapering profile and coupled to the metal ladder bump through direct metal-to-metal bonding. An embodiment chip-to-chip structure may be fabricated in a similar fashion.

A semiconductor package includes a substrate, through-electrodes penetrating the substrate, first bumps spaced apart from each other in a first direction parallel to a top surface of the substrate and electrically connected to the through-electrodes, respectively, and at least one second bump disposed between the first bumps and electrically insulated from the through-electrodes. The first bumps and the at least one second bump constitute one row in the first direction. A level of a bottom surface of the at least one second bump from the top surface of the substrate is a substantially same as levels of bottom surfaces of the first bumps from the top surface of the substrate.

A technique for fabricating bumps on a substrate is disclosed. A substrate that includes a set of pads formed on a surface thereof is prepared. A bump base is formed on each pad of the substrate. Each bump base has a tip extending outwardly from the corresponding pad. A resist layer is patterned on the substrate to have a set of holes through the resist layer. Each hole is aligned with the corresponding pad and having space configured to surround the tip of the bump base formed on the corresponding pad. The set of the holes in the resist layer is filled with conductive material to form a set of bumps on the substrate. The resist layer is stripped from the substrate with leaving the set of the bumps.

A method for bonding two superconducting integrated circuits (“chips”), such that the bonds electrically interconnect the chips. A plurality of indium-coated metallic posts may be deposited on each chip. The indium bumps are aligned and compressed with moderate pressure at a temperature at which the indium is deformable but not molten, forming fully superconducting connections between the two chips when the indium is cooled down to the superconducting state. An anti-diffusion layer may be applied below the indium bumps to block reaction with underlying layers. The method is scalable to a large number of small contacts on the wafer scale, and may be used to manufacture a multi-chip module comprising a plurality of chips on a common carrier. Superconducting classical and quantum computers and superconducting sensor arrays may be packaged.

An IC package including an integrated circuit die having a major surface and one or more solder bumps located on the major surface in at least one corner region of the major surface and a substrate having a surface, the surface including bump pads thereon. The major surface of the integrated circuit die faces the substrate surface, the one or more solder bumps are bonded to individual ones of the bump pads to thereby form a bond joint, the major surface of the integrated circuit die has a footprint area of at least about 400 mm.sup.2. A ratio of a coefficient of thermal expansion of the substrate (CTE.sub.sub) to a coefficient of thermal expansion of the integrated circuit die (CTE.sub.die) is at least about 3:1. A method of manufacturing an IC package is also disclosed.

An integrated circuit structure includes a substrate, a metal pad, a first passivation layer, a second passivation layer, and a conductive bump. The metal pad is over the substrate. The metal pad includes a probing portion and a bumping portion laterally connected to the probing region. The first passivation layer is over the metal pad. The second passivation layer is over the first passivation layer and has an opening. The bumping portion is in the opening. The conductive bump is in the opening of the second passivation layer and contacts the probing portion. The probing portion and the conductive bump are separated by the first passivation layer.