A semiconductor device includes a semiconductor chip having first and second main electrodes disposed on opposite surfaces of a silicon carbide substrate, first and second heat dissipation members disposed so as to sandwich the semiconductor chip, and joining members disposed between the first main electrode and the first heat dissipation member and between the second main electrode and the second heat dissipation member. At least one of the joining members is made of a lead-free solder having an alloy composition that contains 3.2 to 3.8 mass % Ag, 0.6 to 0.8 mass % Cu, 0.01 to 0.2 mass % Ni, x mass % Sb, y mass % Bi, 0.001 to 0.3 mass % Co, 0.001 to 0.2 mass % P, and a balance of Sn, where x and y satisfy relational expressions of x+2y≤11 mass %, x+14y≤42 mass %, and x≥5.1 mass %.

A semiconductor module, including a ceramic board, a circuit pattern metal plate formed on a principal surface of the ceramic board, an external connection terminal bonded, via a solder, to the circuit pattern metal plate, and a low linear expansion coefficient metal plate located between the circuit pattern metal plate and the external connection terminal. The circuit pattern metal plate has a first edge portion and a second edge portion, which are opposite to each other and are respectively at a first side and a second side of the circuit pattern metal plate. The low linear expansion coefficient metal plate has a linear expansion coefficient lower than a linear expansion coefficient of the circuit pattern metal plate.

A semiconductor module, including a ceramic board, a circuit pattern metal plate formed on a principal surface of the ceramic board, an external connection terminal bonded, via a solder, to the circuit pattern metal plate, and a low linear expansion coefficient metal plate located between the circuit pattern metal plate and the external connection terminal. The circuit pattern metal plate has a first edge portion and a second edge portion, which are opposite to each other and are respectively at a first side and a second side of the circuit pattern metal plate. The low linear expansion coefficient metal plate has a linear expansion coefficient lower than a linear expansion coefficient of the circuit pattern metal plate.

A quantum computing system can include a first substrate including one or more quantum control devices. The quantum computing system can include a second substrate including one or more quantum circuit elements. The quantum computing system can include one or more tin contact bonds formed on the first substrate and the second substrate. The tin contact bonds can bond the first substrate to the second substrate. The tin contact bonds can be or can include tin, such as a tin alloy.

A connection structure including: a first circuit member having a plurality of first electrodes; a second circuit member having a plurality of second electrodes; and an intermediate layer having a plurality of bonding portions electrically connecting the first electrodes and the second electrodes, in which at least one of the first electrode and the second electrode that are connected by the bonding portion is a gold electrode, and 90% or more of the plurality of bonding portions include a first region containing a tin-gold alloy and connecting the first electrode and the second electrode and a second region containing bismuth and being in contact with the first region.

A semiconductor device includes a semiconductor die including a first side and an opposing second side, a first metallization layer arranged on the first side, a Ni including layer arranged on the second side, wherein the Ni including layer further includes one or more of Si, Cr and Ti, and a SnSb layer arranged on the Ni comprising layer, wherein an amount of Sb in the SnSb layer is in the range of 2 wt % to 30 wt %.

A semiconductor device includes a semiconductor die including a first side and an opposing second side, a first metallization layer arranged on the first side, a Ni including layer arranged on the second side, wherein the Ni including layer further includes one or more of Si, Cr and Ti, and a SnSb layer arranged on the Ni comprising layer, wherein an amount of Sb in the SnSb layer is in the range of 2 wt % to 30 wt %.

A method of soldering includes providing a substrate having a first metal joining surface, providing a semiconductor die having a second metal joining surface, providing a solder preform having a first interface surface and a second interface surface, arranging the solder preform between the substrate and the semiconductor die such that the first interface surface faces the first metal joining surface and such that the second interface surface faces the second metal joining surface, and performing a mechanical pressure-free diffusion soldering process that forms a soldered joint between the substrate and the semiconductor die by melting the solder preform and forming intermetallic phases in the solder. One or both of the first interface surface and the second interface surface has a varying surface profile that creates voids between the solder preform and one or both of the substrate and the semiconductor die before the melting of the solder preform.

A method of soldering includes providing a substrate having a first metal joining surface, providing a semiconductor die having a second metal joining surface, providing a solder preform having a first interface surface and a second interface surface, arranging the solder preform between the substrate and the semiconductor die such that the first interface surface faces the first metal joining surface and such that the second interface surface faces the second metal joining surface, and performing a mechanical pressure-free diffusion soldering process that forms a soldered joint between the substrate and the semiconductor die by melting the solder preform and forming intermetallic phases in the solder. One or both of the first interface surface and the second interface surface has a varying surface profile that creates voids between the solder preform and one or both of the substrate and the semiconductor die before the melting of the solder preform.

A method for forming a package structure includes forming an under bump metallization (UBM) layer over a metal pad and forming a photoresist layer over the UBM layer. The method further includes patterning the photoresist layer to form an opening in the photoresist layer. The method also includes forming a first bump structure over the first portion of the UBM layer. The first bump structure includes a first barrier layer over a first pillar layer. The method includes placing a second bump structure over the first bump structure. The second bump structure includes a second barrier layer over a second pillar layer. The method further includes reflowing the first bump structure and the second bump structure to form a solder joint between a first inter intermetallic compound (IMC) and a second IMC.