Provided are a lead-free solder alloy which consists of Sb in an amount of more than 3.0% but 10% or less by mass, and the balance including Sn, and others.

Devices and techniques including process steps make use of recesses in conductive interconnect structures to form reliable low temperature metallic bonds. A fill layer is deposited into the recesses prior to bonding. The fill layer is composed of noble metal (such as copper) and active metal (such as Zn). Then the fill metal layer is turned into a metal alloy after annealing. A dealloying is performed to the metal alloy to remove the active metal from the metal alloy while the noble metal remains to self-assemble into porous (nanoporous) structure metal. First conductive interconnect structures are bonded at ambient temperatures to second metallic interconnect structures using dielectric-to-dielectric direct bonding techniques, with the fill nanoporous metal layer in the recesses in one of the first and second interconnect structures. After the following batch annealing, the fill nanoporous metal layer turns into pure bulk metal same as conductive interconnect structures due to the heat expansion of conductive interconnect structures and nanoporous metal densification.

Methods, techniques, and structures relating to die packaging. In one exemplary implementation, a die package interconnect structure includes a semiconductor substrate and a first conducting layer in contact with the semiconductor substrate. The first conducting layer may include a base layer metal. The base layer metal may include Cu. The exemplary implementation may also include a diffusion barrier in contact with the first conducting layer and a wetting layer on top of the diffusion barrier. A bump layer may reside on top of the wetting layer, in which the bump layer may include Sn, and Sn may be electroplated. The diffusion barrier may be electroless and may be adapted to prevent Cu and Sn from diffusing through the diffusion barrier. Furthermore, the diffusion barrier may be further adapted to suppress a whisker-type formation in the bump layer.

A method of forming a semiconductor package is provided. The method includes forming a metallization stack over a semiconductor die. Polymer particles are mounted over the metallization stack. Each of the polymer particles is coated with a first bonding layer. A heat spreader lid is bonded with the semiconductor die by reflowing the first bonding layer. A composite thermal interface material (TIM) structure is formed between the heat spreader lid and the semiconductor die during the bonding. The composite TIM structure includes the first bonding layer and the polymer particles embedded in the first bonding layer.

A method of forming a semiconductor package is provided. The method includes forming a metallization stack over a semiconductor die. Polymer particles are mounted over the metallization stack. Each of the polymer particles is coated with a first bonding layer. A heat spreader lid is bonded with the semiconductor die by reflowing the first bonding layer. A composite thermal interface material (TIM) structure is formed between the heat spreader lid and the semiconductor die during the bonding. The composite TIM structure includes the first bonding layer and the polymer particles embedded in the first bonding 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 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 package structure and a method for connecting components are provided, in which the package includes a first substrate including a first wiring and at least one first contact connecting to the first wiring; a second substrate including a second wiring and at least one second contact connecting to the second wiring, the at least one first contact and the at least one second contact partially physically contacting with each other or partially chemically interface reactive contacting with each other; and at least one third contact surrounding the at least one first contact and the at least one second contact. The first substrate and the second substrate are electrically connected with each other at least through the at least one first contact and the at least one second contact.

A semiconductor device package and a fabrication method thereof are disclosed. The semiconductor package comprises: a package component having a first mounting surface and a second mounting surface; and a first electronic component having a first conductive pad signal communicatively mounted on the first mounting surface through a first type connector; wherein the first type connector comprises a first solder composition having a lower melting point layer sandwiched between a pair of higher melting point layers, wherein the lower melting point layer is composed of alloys capable of forming a room temperature eutectic.

Semiconductor die assemblies having interconnect structures with redundant electrical connectors are disclosed herein. In one embodiment, a semiconductor die assembly includes a first semiconductor die, a second semiconductor die, and an interconnect structure between the first and the second semiconductor dies. The interconnect structure includes a first conductive film coupled to the first semiconductor die and a second conductive film coupled to the second semiconductor die. The interconnect structure further includes a plurality of redundant electrical connectors extending between the first and second conductive films and electrically coupled to one another via the first conductive film.