There are two kinds of soldering about PV RIBBON, one is soldering of leaded PV RIBBON and one is soldering of lead-free PV RIBBON. Among them, leaded PV RIBBON is easier to solder, generally speaking, as long as you choose the right flux, the temperature compensation of the soldering iron is enough to use. But the soldering of lead-free PV RIBBON is really troublesome, and many manufacturers find it a headache. First, lead-free soldering to choose a suitable soldering iron.
For manufacturers, the choice of power adjustable lead-free soldering station is a good choice. Lead-free soldering stations generally use a DC power supply with adjustable voltage. DC soldering iron has the advantage of fast temperature compensation. This is the AC temperature-controlled soldering iron can not be compared. Lead-free PV RIBBON soldering according to the thickness and area of the battery should choose 70-100w soldering iron, less than 70w soldering iron will generally have problems in lead-free soldering.
Soldering of lead-free PV RIBBON
In the process of soldering lead-free PV RIBBON, manufacturers should pay attention to adjust the welding habits of workers. Lead-free solder is not very fluid. And the soldering speed should be slower. Soldering must wait until the solder is completely dissolved before walking the soldering iron, and the speed of walking the iron should be slow. If you find that the process of walking the soldering iron solder solidification, indicating that the temperature of the soldering iron head is low, to adjust the temperature of the soldering iron head. Go on the head of the soldering iron to move smoothly, until the smooth flow of solder.
Correct use of lead-free solder tape
With the implementation of the EU ROHS Directive in June 2006. Chinese PV industry exports are facing the choice of lead-free. Lead-free PV RIBBON has many disadvantages compared with traditional PV RIBBON, how to overcome these disadvantages is a process problem that many PV manufacturers urgently need to solve.
Lead-free PV RIBBON is divided into many different kinds according to the composition of the coated solder. Our most widely used lead-free solder is 305 solder, which contains 3% silver and 0.5% copper. The advantage of this solder is good solderability solder high, melting point of 218C for the welding of battery cells on the welding temperature requirements are very high, and the ordinary internal heating type soldering iron is difficult to achieve the temperature requirements. Therefore, the soldering of lead-free PV RIBBON should use a high-power soldering iron. It is generally recommended to use 30-40W higher than soldering leaded solder. for example, the original use of 35W soldering iron. Then lead-free soldering should use more than 70W soldering iron.
The fluidity of lead-free solder
The fluidity of lead-free solder is very poor. Soldering to wait for the tin coated with solder to fully melt before walking the iron, walk the speed of the iron to slow. The tip of the soldering iron catches the melted solder and moves slowly. If the solder is found to have solidified or incompletely melted, it means that the temperature compensation of the soldering iron head is not enough. And the temperature of the soldering iron head has been lower than the melting point of the solder.
Many lead-free temperature-controlled soldering irons on the market are most prone to this phenomenon. When the tip of the soldering iron touches the battery, the temperature reaches 400 C. The temperature of the tip of the iron will suddenly drop below 250°C, making it difficult to continue soldering. Manufacturers are advised to choose a lead-free soldering station with a large iron tip by adjusting the DC voltage to adjust the temperature of the soldering iron. Instead, do not choose a thermo-magnetic controlled temperature-regulating soldering iron. Welding different types of battery cells has different requirements for the soldering iron. Generally large battery cells have higher requirements for the thickness of the soldering iron. And large battery cells require a higher area for the soldering iron. The choice of DC lead-free soldering station can basically solve the problem of welding temperature.
Lead-free PV RIBBON will change color soon after soldering. This is because lead-free solder is more likely to be oxidized, which is a normal phenomenon.
