LEAD-FREE SOLDER ALLOY, SOLDER PASTE COMPOSITION, ELECTRONIC CIRCUIT BOARD, AND ELECTRONIC CONTROLLER

• Main Authors: HORI ATSUSHI, ARAI MASAYA, MUNEKAWA YURIKA, NAKANO KEN, KATSUYAMA TSUKASA
• Format: Patent
• Language: English; Japanese
• Published: 30.05.2019
• Subjects: ALLOYS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; CHEMISTRY; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; MACHINE TOOLS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METALLURGY; PERFORMING OPERATIONS; PRINTED CIRCUITS; SOLDERING OR UNSOLDERING; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WELDING; WORKING BY LASER BEAM

To provide a lead-free solder alloy, a solder paste composition, an electronic circuit board, and an electronic controller that can suppress cracking development of a solder joint part even in a severe environment in which differences in temperature are large and a load of vibration is placed, and also suppress cracking development nearby a boundary surface between an electronic component and the solder joint part even when the electronic component has neither Ni/Pd/Au plating nor Ni/Au plating performed on and is soldered.SOLUTION: The present invention relates to a lead-free solder alloy consisting of 1-2 wt.% of Ag, 0.5-0.7 wt.% of Cu, 2-4 wt.% of Sb, 2-4.5 wt.% of Bi, 0.01-0.03 wt.% of Ni, and Sn for the rest.SELECTED DRAWING: Figure 1 【課題】 寒暖の差が激しく、振動が負荷されるような過酷な環境下においてもはんだ接合部の亀裂進展を抑制でき、且つＮｉ／Ｐｄ／ＡｕめっきやＮｉ／Ａｕめっきがなされていない電子部品を用いてはんだ接合をした場合においても電子部品とはんだ接合部の界面付近における亀裂進展を抑制することのできる鉛フリーはんだ合金、ソルダペースト組成物、電子回路基板および電子制御装置の提供。【解決手段】 Ａｇを１重量％以上２重量％以下と、Ｃｕを０．５重量％以上０．７重量％以下と、Ｓｂを２重量％以上４重量％以下と、Ｂｉを２重量％以上４．５重量％以下と、Ｎｉを０．０１重量％以上０．０３重量％以下含み、残部がＳｎからなることを特徴とする鉛フリーはんだ合金。【選択図】図１