Sn-Cu base leadless solder alloy and preparation method

[0019] 1. Weigh P 4% and Sn 96% according to the mass ratio, which is 50 grams in total, then put the two into a graphite crucible, and cover the above-mentioned molten salt on it, place the crucible in a resistance furnace, Keep the temperature at 450°C for 45 minutes, stir evenly and then cast to obtain the Sn-P master alloy;

[0020] 2. Based on the total mass as 100%, weigh the Sn-P master alloy with the amount of P accounting for 0.1%, then weigh Cu 0.7%, the balance is Sn, and the total weight is 100 grams. Put the ingredients into a graphite crucible, cover it with the above-mentioned protective molten salt, place the crucible in a resistance furnace, keep it warm at 450°C for 60 minutes, stir it evenly and cast it into an ingot to obtain the required solder alloy.

[0021] According to the above method, a series of Sn-Cu alloys with different P contents were welded for the measurement of wettability and oxidation resistance; the influence of solder alloys with differen...

[0025] 1. Take P 4% and Sn 96% according to the mass ratio, which is 50 grams in total, then put the two into a graphite crucible, and cover the above-mentioned molten salt on it, place the crucible in an induction furnace, Insulate at a temperature of 500°C for 30 minutes, stir evenly and then cast to obtain a Sn-P master alloy;

[0026] 2. Based on the total mass of 100%, weigh the Sn-P master alloy with the amount of P accounting for 0.05%, then weigh Cu 0.7%, P 0.05%, Bi 1%, the balance is Sn, and the total weight is 100 gram. Put the ingredients into a graphite crucible, cover it with the above-mentioned protective molten salt, place the crucible in an induction furnace, keep it warm at 500°C for 30 minutes, stir it evenly, and cast it into an ingot to obtain the required solder alloy.

[0027] A series of Sn-0.7Cu-based alloys with different Bi content and P content were melted according to the above method for wettability and melting point measurement. The wettability...

[0029] 1. Take P 4% and Sn 96% according to the mass ratio, which is 50 grams in total, then put the two into a graphite crucible, and cover the above-mentioned molten salt on it, place the crucible in an induction furnace, Keep the temperature at 400°C for 60 minutes, stir evenly and then cast to obtain the Sn-P master alloy;

[0030] 2. Based on the total mass of 100%, weigh the Sn-P master alloy with the amount of P accounting for 0.05%, and then weigh Cu 0.7%, P0.05%, Bi1%, Zn1%, the balance is Sn, the total The weight is 100 grams. Put the ingredients into a graphite crucible, cover it with the above-mentioned protective molten salt, place the crucible in an induction furnace, keep it warm at 500°C for 30 minutes, stir it evenly, and cast it into an ingot to obtain the required solder alloy.

[0031] A series of Sn-0.7Cu-1Bi-1Zn alloys with P content were welded according to the above method for wettability measurement. The wettability of each alloy to Cu is characterized...