Reducing dross method of lead-free solder
A reducing dross method of lead-free solder includes the steps of: producing master alloy of reducing dross which comprises Sn and 0.1 to 0.8 wt % P; analyzing the percentage of P of the lead-free solder to be modified, in order to reach 0.008 to 0.015 wt % P in the lead-free solder, adding the master alloy into the lead-free solder with the percentage of P less than 0.008 wt % or no P; then sampling the lead-free solder at regular intervals to determine the percentage and the percentage loss of P, if the percentage of P being less than a given value from 0.008 to 0.015 wt %, adding the master alloy to keep the percentage of P as 0.008 to 0.015 wt %.
1. A reducing dross method of lead-free solder, comprising the steps of:
firstly producing alloy of reducing dross by a master alloy process, the alloy of reducing dross comprising Sn and 0.1 to 0.8 wt % P;
analyzing a percentage of P of the lead-free solder to be modified in a soldering furnace;
if the percentage of P of the lead-free solder is less than 0.008 wt %, adding the alloy of reducing dross into the lead-free solder until the percentage of P of the lead-free solder in the soldering furnace reaches within 0.008 to 0.015 wt % P;
then sampling the lead-free solder in the soldering furnace at regular intervals to determine the percentage and a percentage loss of P of the lead-free solder in the soldering furnace;
if the percentage of P of the lead-free solder in the soldering furnace is less than 0.008 wt %, adding the alloy of reducing dross calculated according to the percentage loss of P in an amount needed for maintaining the percentage of P of the lead-free solder as 0.008 to 0.015 wt %.
2. The reducing dross method of lead-free solder according to claim 1 ,
wherein the lead-free solder is an alloy solder including Sn and Ag.
3. The reducing dross method of lead-free solder according to claim 1 ,
wherein the lead-free solder is an alloy solder including Sn and Cu.
4. The reducing dross method of lead-free solder according to claim 1 ,
wherein the lead-free solder is an alloy solder including Sn, Ag and Cu.
5. The reducing dross method of lead-free solder according to claim 1 ,
wherein the lead-free solder is Sn-3-3.5Ag-0.5-0.7Cu alloy solder.
6. The reducing dross method of lead-free solder according to claim 1 ,
wherein the alloy of reducing dross is Sn-0.1-0.8P alloy.
7. The reducing dross method of lead-free solder according to claim 1 ,
wherein the alloy of reducing dross is Sn-3-3.5Ag-0.1-0.8P alloy.
8. The reducing dross method of lead-free solder according to claim 1 ,
wherein the alloy of reducing dross is Sn-3-3.5Ag-0.5-0.7Cu-0.1-0.8P alloy.
9. The reducing dross method of lead-free solder according to claim 1 ,
wherein the regular intervals is 8 to 48 hours.