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 method of manufacturing a semiconductor device includes providing a carrier, disposing a first pad on the carrier, forming a post on the first pad, and disposing a joint adjacent to the post and the first pad to form a first entire contact interface between the first pad and the joint and a second entire contact interface between the first pad and the post. The first entire contact interface and the second entire contact interface are flat surfaces.

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 device includes a first carrier including a first pad, a second carrier including a second pad disposed opposite to the first pad, a joint coupled with and standing on the first pad, a joint encapsulating the post and bonding the first pad with the second pad, a first entire contact interface between the first pad and the joint, a second entire contact interface between the first pad and the post, and a third entire contact interface between the joint and the second pad. The first entire contact interface, the second entire contact interface and the third entire contact interface are flat surfaces. A distance between the first entire contact interface and the third entire contact interface is equal to a distance between the second entire contact interface and the third entire contact interface. The second entire contact interface is a continuous surface.

Embodiments relate to the design of an electronic device capable of preventing a lateral motion between a first body and a second body. The device comprises a first body comprising one or more atomic force microscopy (AFM) tips protruding from a first surface of the first body. The device further comprises a second body comprising one or more electrical contacts on a second surface of the second body. The second surface faces the first surface. The one or more electrical contacts pierced by the AFM tips of the first surface to prevent a lateral motion between the first body and the second body.

Embodiments relate to the design of an electronic device capable of preventing a lateral motion between a first body and a second body. The device comprises a first body comprising one or more atomic force microscopy (AFM) tips protruding from a first surface of the first body. The device further comprises a second body comprising one or more electrical contacts on a second surface of the second body. The second surface faces the first surface. The one or more electrical contacts pierced by the AFM tips of the first surface to prevent a lateral motion between the first body and the second body.

External electrical connectors and methods of forming such external electrical connectors are discussed. A method includes forming an external electrical connector structure on a substrate. The forming the external electrical connector structure includes plating a pillar on the substrate at a first agitation level affected at the substrate in a first solution. The method further includes plating solder on the external electrical connector structure at a second agitation level affected at the substrate in a second solution. The second agitation level affected at the substrate is greater than the first agitation level affected at the substrate. The plating the solder further forms a shell on a sidewall of the external electrical connector structure.

External electrical connectors and methods of forming such external electrical connectors are discussed. A method includes forming an external electrical connector structure on a substrate. The forming the external electrical connector structure includes plating a pillar on the substrate at a first agitation level affected at the substrate in a first solution. The method further includes plating solder on the external electrical connector structure at a second agitation level affected at the substrate in a second solution. The second agitation level affected at the substrate is greater than the first agitation level affected at the substrate. The plating the solder further forms a shell on a sidewall of the external electrical connector structure.

A system of producing metal cored solder structures on a substrate includes: a decal, a carrier, and receiving elements. The decal includes one or more apertures each of which is tapered from a top surface to a bottom surface thereof. The carrier is positioned beneath the bottom of the decal and includes cavities in a top surface. The cavities are located in alignment with the apertures of the decal. The decal is positioned on the carrier having the decal bottom surface in contact with the carrier top surface to form feature cavities defined by the decal apertures and the carrier cavities. The feature cavities are shaped to receive one or more metal elements and are configured for receiving molten solder cooled in the cavities. The decal is separable from the carrier to partially expose metal core solder contacts. The receiving elements receive the metal core solder contacts thereon.

A method of manufacturing a semiconductor device includes providing a carrier, disposing a first pad on the carrier, forming a post on the first pad, and disposing a joint adjacent to the post and the first pad to form a first entire contact interface between the first pad and the joint and a second entire contact interface between the first pad and the post. The first entire contact interface and the second entire contact interface are flat surfaces.