Brazing strip or sheet comprising: a core layer made of aluminum alloy; a brazing layer made of aluminum alloy, clad on at least one face of the core layer; optionally an intermediate layer made of aluminum alloy, clad on at least one face either between the core layer and the brazing layer or the core layer without any other layer on top; characterized in that the brazing layer alloy comprises, in mass percentages:
from 7 to 13% Si, at most 0.8% Fe, at most 0.45% Cu, at most 0.20% Mn, at most 0.15% Mg, at most 0.20% Zn, at most 0.20% Ti, at most 0.04% Bi, from 0.01 to 0.10% Y, from 0.01 to 0.10% Sn, remainder aluminum and impurities.

Some implementations of the disclosure are directed to a solder preform, comprising: a solder alloy body, the solder alloy body comprising at least one opening; and a flux core embedded in the solder alloy body, the flux core comprising a thermochromic indicator, wherein during reflow soldering, the flux core comprising the thermochromic indicator is configured to flow out of the at least one opening of the solder alloy.

A lead-free solder alloy comprising: from 2.5 to 5 wt. % silver; from 0.01 to 5 wt. % bismuth; from 1 to 7 wt. % antimony; from 0.01 to 2 wt. % copper; one or more of: up to 6 wt. % indium, up to 0.5 wt. % titanium, up to 0.5 wt. % germanium, up to 0.5 wt. % rare earths, up to 0.5 wt. % cobalt, up to 5.0 wt. % aluminium, up to 5.0 wt. % silicon, up to 0.5 wt. % manganese, up to 0.5 wt. % chromium, up to 0.5 wt. % iron, up to 0.5 wt. % phosphorus, up to 0.5 wt. % gold, up to 1 wt. % gallium, up to 0.5 wt. % tellurium, up to 0.5 wt. % selenium, up to 0.5 wt. % calcium, up to 0.5 wt. % vanadium, up to 0.5 wt. % molybdenum, up to 0.5 wt. % platinum, and up 0 to 0.5 wt. % magnesium; optionally up to 0.5 wt. % nickel; and the balance tin together with any unavoidable impurities.

Provided is a preform solder including a first metal containing Sn and a second metal formed of an alloy containing Ni and Fe. Alternatively, provided is a preform solder (1) having a metal structure including a first phase (10) that is a continuous phase and a second phase (20) dispersed in the first phase (10), the first phase (10) contains Sn, the second phase (20) is formed of an alloy containing Ni and Fe, and a grain boundary (15) of a metal is present in the first phase (10).

Provided is a method of manufacturing a semiconductor having a double-sided substrate including preparing a first substrate on which a specific pattern is formed to enable electrical connection, preparing at least one semiconductor chip bonded to a metal post, bonding the at least one semiconductor chip to the first substrate, bonding a second substrate to the metal post, forming a package housing by packaging the first substrate and the second substrate to expose a lead frame, and forming terminal leads toward the outside of the package housing. Accordingly, the semiconductor chip and the metal post are previously joined to each other and are respectively bonded to the first substrate and the second substrate so that damage generated while bonding the semiconductor chip may be minimized and electrical properties and reliability of the semiconductor chip may be improved.

Provided is a preform solder including a first metal containing Sn and a second metal formed of an alloy containing Ni and Fe. Alternatively, provided is a preform solder (1) having a metal structure including a first phase (10) that is a continuous phase and a second phase (20) dispersed in the first phase (10), the first phase (10) contains Sn, the second phase (20) is formed of an alloy containing Ni and Fe, and a grain boundary (15) of a metal is present in the first phase (10).

A process for producing an amorphous ductile brazing foil is provided. According to one example embodiment, the method includes providing a molten mass, and rapidly solidifying the molten mass on a moving cooling surface with a cooling speed of more than approximately 10.sup.5° C./sec to produce an amorphous ductile brazing foil. A process for joining two or more parts is also provided. The process includes inserting a brazing foil between two or more parts to be joined, wherein the parts to be joined have a higher melting temperature than that the brazing foil to form a solder joint and the brazing foil comprises an amorphous, ductile Ni-based brazing foil; heating the solder joint to a temperature above the liquidus temperature of the brazing foil to form a heated solder joint; and cooling the heated solder joint, thereby forming a brazed joint between the parts to be joined.

A method of manufacturing a plate-shaped solder according to the invention of the present application includes an aggregating step of aggregating a plurality of thread solders and a crimping step of crimping the plurality of aggregated thread solders to one another to form a plate-shaped solder. A manufacturing device of a plate-shaped solder according to the invention of the present application includes an aggregating portion for aggregating a plurality of thread solders and a crimping portion for crimping the plurality of thread solders to one another in the aggregating portion to form a plate-shaped solder.

A solder material for use in electronic assembly, the solder material comprising: solder layers; and a core layer comprising a core material, the core layer being sandwiched between the solder layers, wherein: the thermal conductivity of the core material is greater than the thermal conductivity of the solder.

An aluminum alloy bare material for a member to be brazed by flux-free brazing to a brazing sheet including a brazing material formed of an aluminum alloy that includes 3.00 to 13.00 mass % of Si and 0.10 to 2.00 mass % of Mg with the balance being Al and inevitable impurities, in which the aluminum alloy bare material for the member to be brazed is formed of an aluminum alloy including 0.004 to 6.00 mass % of Zn and 0.004 to 3.00 mass % of Mg with the balance being Al and inevitable impurities. According to the present invention, aluminum alloy materials can be provided for members to be well brazed to the brazing sheet with the brazing material including Mg when an aluminum material is brazed by flux-free brazing.