A method of forming a chip assembly may include forming a plurality of cavities in a carrier; The method may further include arranging a die attach liquid in each of the cavities; arranging a plurality of chips on the die attach liquid, each chip comprising a rear side metallization and a rear side interconnect material disposed over the rear side metallization, wherein the rear side interconnect material faces the carrier; evaporating the die attach liquid; and after the evaporating the die attach liquid, fixing the plurality of chips to the carrier.

Provided is a metal jointed body, joined by solid-phase joining in the atmosphere, in which no protrusion of molten joining material occurs, that improves dimensional stability. A metal jointed body is formed by (A) making Ag films of two metal laminated bodies opposed to each other, the metal jointed body being configured by sequentially laminating a Zn film and an Ag film on an Al substrate serving as a member to be joined, and (B) bringing the Ag films into contact with each other, then (C) heating is performed while pressurizing, and closely adhering and solid-phase joining the Ag films to each other. The completed metal jointed body is a portion where Al—Ag alloy layers are provided on both sides of an Ag—Zn—Al alloy layer to join the Al substrates to each other.

A semiconductor device including an insulating circuit board. The insulating circuit board has an insulating plate, a plurality of circuit patterns disposed on a front surface of the insulating plate, any adjacent two of the circuit patterns having a gap therebetween, each circuit pattern having at least one corner, each corner being in a corner area that covers the corner and a portion of each gap adjacent to the corner, and a buffer material containing resin, applied at a plurality of corner areas, to fill the gaps in the plurality of corner areas.

A semiconductor device including an insulating circuit board. The insulating circuit board has an insulating plate, a plurality of circuit patterns disposed on a front surface of the insulating plate, any adjacent two of the circuit patterns having a gap therebetween, each circuit pattern having at least one corner, each corner being in a corner area that covers the corner and a portion of each gap adjacent to the corner, and a buffer material containing resin, applied at a plurality of corner areas, to fill the gaps in the plurality of corner areas.

A semiconductor package includes: a first package substrate; a first semiconductor device mounted on the first package substrate; a second package substrate arranged on an upper part of the first semiconductor device; and a heat-dissipating material layer arranged between the first semiconductor device and the second package substrate and having a thermal conductivity of approximately 0.5 W/m.Math.K to approximately 20 W/m.Math.K, wherein the heat-dissipating material layer is in direct contact with an upper surface of the first semiconductor device and a conductor of the second package substrate.

A semiconductor package includes: a first package substrate; a first semiconductor device mounted on the first package substrate; a second package substrate arranged on an upper part of the first semiconductor device; and a heat-dissipating material layer arranged between the first semiconductor device and the second package substrate and having a thermal conductivity of approximately 0.5 W/m.Math.K to approximately 20 W/m.Math.K, wherein the heat-dissipating material layer is in direct contact with an upper surface of the first semiconductor device and a conductor of the second package substrate.

A semiconductor device includes: a semiconductor die having a metal region; a substrate having a metal region; and a soldered joint between the metal region of the semiconductor die and the metal region of the substrate. One or more intermetallic phases are present throughout the entire soldered joint, each of the one or more intermetallic phases formed from a solder preform diffused into the metal region of the semiconductor die and the metal region of the substrate. The soldered joint has the same length-to-width aspect ratio as the semiconductor die.

A semiconductor device includes: a semiconductor die having a metal region; a substrate having a metal region; and a soldered joint between the metal region of the semiconductor die and the metal region of the substrate. One or more intermetallic phases are present throughout the entire soldered joint, each of the one or more intermetallic phases formed from a solder preform diffused into the metal region of the semiconductor die and the metal region of the substrate. The soldered joint has the same length-to-width aspect ratio as the semiconductor die.

A layer structure includes a first layer including at least one material selected from a first group consisting of nickel, copper, gold, silver, palladium, tin, zinc, platinum, and an alloy of any of these materials; a third layer including at least one material selected from a second group consisting of nickel, copper, gold, palladium, tin, silver, zinc, platinum, and an alloy of any of these materials; and a second layer between the first layer and the third layer. The second layer consists of or essentially consists of nickel and tin. The second layer includes an intermetallic phase of nickel and tin.

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.