Lead-free reinforced solder alloy and preparation method thereof

The invention discloses a lead-free reinforced solder alloy and a preparation method thereof. The lead-free reinforced solder alloy comprises the following chemical components in percentage by weight: 1-8% of Sb; 1%-8% of Bi; 0.4% to 0.8% of Cu; 2.5% to 3.5% of Ag; 0.001% to 1% of Zr; 0.001% to 1% of Ti; and the balance of Sn. Elements Bi, Sb, Zr and Ti are added to reinforce a second phase and refine grains to reinforce the high-temperature mechanical property, so that the lead-free reinforced solder can bear higher load and environment temperature; and meanwhile, the lead-free reinforced solder is good in plasticity, forming processing capacity and wettability, low in welding void rate, small in melting point change, longer in service life and high in replaceability, and an existing welding technology does not need to be changed. According to the preparation method, the Sn-Zr intermediate alloy, the Sn-Cu-Zr intermediate alloy, the ZrH2 powder or the Cu-Zr intermediate alloy is used for preparing the lead-f