A semiconductor package includes a power semiconductor chip comprising SiC, a leadframe part comprising Cu, wherein the power semiconductor chip is arranged on the leadframe part, and a solder joint electrically and mechanically coupling the power semiconductor chip to the leadframe part, wherein the solder joint comprises at least one intermetallic phase.

A solder joint in which an electronic component with a back metal is bonded to a substrate by a solder alloy. The solder alloy includes: a solder alloy layer having an alloy composition consisting of, in mass %: Ag: 2 to 4%, Cu: 0.6 to 2%, Sb: 9.0 to 12%, Ni: 0.005 to 1%, optionally Co: 0.2% or less and Fe: 0.1% or less, with the balance being Sn; an Sn—Sb intermetallic compound phase; a back metal-side intermetallic compound layer formed at an interface between the back metal and the solder alloy; and a substrate-side intermetallic compound layer formed at an interface between the substrate and the solder alloy. The solder alloy layer exists at least one of between the Sn—Sb intermetallic compound phase and the back metal-side intermetallic compound layer, and between the Sn—Sb intermetallic compound phase and the substrate-side intermetallic compound layer.

A method of joining a semiconductor die to a substrate includes: applying a solder preform to a metal region of the semiconductor die or to a metal region of the substrate, the solder preform having a maximum thickness of 30 μm and a lower melting point than both metal regions; forming a soldered joint between the metal region of the semiconductor die and the metal region of the substrate via a diffusion soldering process and without applying pressure directly to the die; and setting a soldering temperature of the diffusion soldering process so that the solder preform melts and fully reacts with the metal region of the semiconductor die and the metal region of the substrate to form one or more intermetallic phases throughout the entire soldered joint, each intermetallic phase having a melting point above the melting point of the preform and the soldering temperature.

A method of batch soldering includes: forming a soldered joint between a metal region of a first semiconductor die and a metal region of a substrate using a solder preform via a soldering process which does not apply pressure directly to the first semiconductor die, the solder preform having a maximum thickness of 30 μm and a lower melting point than the metal regions; setting a soldering temperature of the soldering process so that the solder preform melts and fully reacts with the metal region of the first semiconductor die and the metal region of the substrate to form one or more intermetallic phases throughout the entire soldered joint, each intermetallic phase having a melting point above the preform melting point and the soldering temperature; and soldering a second semiconductor die to the same or different metal region of the substrate, without applying pressure directly to the second semiconductor die.

A method of forming a solar cell device that includes forming a porous layer in a monocrystalline donor substrate and forming an epitaxial semiconductor layer on the porous layer. A solar cell structure is formed on the epitaxial semiconductor layer. A carrier substrate is bonded to the solar cell structure through a bonding layer. The monocrystalline donor substrate is removed by cleaving the porous layer. A grid of metal contacts is formed on the epitaxial semiconductor layer. The exposed portions of the epitaxial semiconductor layer are removed. The exposed surface of the solar cell structure is textured. The textured surface may be passivated, in which the passivated surface can provide an anti-reflective coating.

The present disclosure provides a method of creating a bond between a first object and a second object. For example, creating a joint or die attach between a semiconductor chip and an electronic substrate, especially for harsh and high temperature environments. The method may include a step of filling a space between the first object and the second object with a filler material. Further, the method may include a step of heating the filler material to facilitate formation of a plurality of inter-diffusion layers. Accordingly, a first inter-diffusion layer may be formed between the filler material and the first object. Further, a second inter-diffusion layer may be formed between the filler material and the second object. Furthermore, in some embodiments, the first inter-diffusion layer may be contiguous with the second inter-diffusion layer. The contiguity may be facilitated by placement of at least one insert between the first object and the second object, in which the inter-diffusion of the filler material and the at least one insert may produce the third inter-diffusion layer, wherein the third inter-diffusion layer is contiguous with each of the first inter-diffusion layer and the second inter-diffusion layer.

An arrangement is disclosed. In one example, the arrangement of a conductor and an aluminum layer soldered together comprises a substrate and the aluminum layer disposed over the substrate. The aluminum forms a first bond metal. An intermetallic compound layer is disposed over the aluminum layer. A solder layer is disposed over the intermetallic compound layer, wherein the solder comprises a low melting majority component. The conductor is disposed over the solder layer, wherein the conductor has a soldering surface which comprises a second bond metal. The intermetallic compound comprises aluminum and the second bond metal and is predominantly free of the low melting majority component.

Provided among other things is an electrical device comprising: a first component that is a semiconductor or an electrical conductor; a second component that is an electrical conductor; and a strong, heat stable junction there between including an intermetallic bond formed of: substantially (a) tin (Sn) or a mixture of Sn and indium (In) thereof, and (b) substantially nickel (Ni). The junction can have an electrical contact resistance that is small compared to the resistance of the electrical device.

Methods for forming bonded assemblies using metal inverse opal and cap structures are disclosed. In one embodiment, a method for forming a bonded assembly includes positioning a substrate against a polymer support that is porous, depositing a metal onto and within the polymer support, disposing a cap layer to the polymer support opposite of the substrate to form a bottom electrode, and removing the polymer support from between the substrate and the cap layer to form a metal inverse opal structure disposed therebetween.

A method for soldering a die obtained using the semiconductor technique with a leadframe, comprising the steps of providing a leadframe, which has at least one surface made at least partially of copper; providing a die, which has at least one surface coated with a metal layer; applying to the surface a solder alloy comprising at least 40 wt % of tin or at least 50% of indium or at least 50% of gallium, without lead, and heating the alloy to a temperature of at least 380 C. to form a drop of solder alloy; providing a die, which has at least one surface coated with a metal layer; and setting the metal layer in contact with the drop of solder alloy to form the soldered connection with the leadframe. Moreover, a device obtained with said method is provided.