Preform solder and method of manufacturing the same, and method of manufacturing solder joint
AssigneeSenju Metal Industry Co., Ltd.
InventorsShunsuke Koga, Tomoki Sasaki, Yoshie Tachibana, Shunsaku Yoshikawa
Life of this patent
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Abstract
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).
Claims3
A preform solder comprising a first metal containing Sn, and a second metal formed of an alloy containing Ni and Fe,
- wherein a melting point of the first metal is 250° C. or less,
- a melting point of the alloy in the second metal exceeds 250° C.,
- a content of Sn in the first metal is 100 mass % or less with respect to a total mass of the first metal,
- a content of Ni in the second metal is 80 mass % or more and 99 mass % or less with respect to a total mass of the second metal,
- a content of Fe in the second metal is 1 mass % or more and 20 mass % or less with respect to the total mass of the second metal,
- a particle size of the second metal is 0.1 to 1000 μm,
- a content of the second metal is 5 to 70 mass % with respect to a total content of the first metal and the second metal, and
- when the preform solder is mounted on a Cu board having a thickness of 0.5 mm and a size of 50 mm ×50 mm, an Si board having a thickness of 0.4 mm and a size of 5 mm ×5 mm is mounted on the preform solder, soldering is performed, and then, in a profile in which a peak temperature is 250° C. and a cooling speed is 2° C./sec, the soldering is performed in a reflow furnace with no pressurization or with pressurization under formic acid atmosphere to fabricate a solder joint, the solder joint has a shear strength of 1.0 N or more in a bonding area, the shear strength being measured under a condition of 6.0 mm/min and 250° C.
A preform solder having a metal structure comprising a first phase that is a continuous phase, and a second phase dispersed in the first phase,
- wherein the first phase is formed of a metal containing Sn,
- the second phase is composed of an alloy containing Ni and Fe,
- a melting point of the metal that composes the first phase is 250° C. or less,
- a melting point of the alloy that composes the second phase exceeds 250° C.,
- a content of Sn in the metal that composes the first phase is 20 mass % or more and 100 mass % or less with respect to a total mass of the metal,
- a content of Ni in the alloy that composes the second phase is 80 mass % or more and 99 mass % or less with respect to a total mass of the alloy,
- a content of Fe in the alloy that composes the second phase is 1 mass % or more and 20 mass % or less with respect to the total mass of the alloy,
- a particle size of the alloy is 0.1 to 1000 μm,
- the content of the alloy that composes the second phase is 5 to 70 mass % with respect to a total content of the metal that composes the first phase and the alloy that composes the second phase, and
- a grain boundary of the metal is present in the first phase.
Dependencies are inferred from the claim text.