Alpha lead free solder wire
Compliance with the soldering technology, Alpha lead free solder wire is a guarantee of the reliability of the manufactured electronic or electrical equipment. The largest number of its failures comes precisely with the high transient resistance of contact groups, including soldered joints.
In high-reliability equipment, mechanical electrical contacts are rarely common - all connections are made only by soldering or welding. At the same time, their multiple failures come fter with poor-quality soldering - when its appearance does not cause any complaints, but the current does not pass through the connection. The reason is a violation of the process technology.
How to properly solder wires with Alpha lead free solder wire?
It is necessary to connect non-ferrous metals with Alpha lead free solder wire and among themselves so that they do not get into the melt:
- a transition layer of the protective coating of the wire (usually it is an electrical varnish)
- dirt and fatty components
- oxide films on metal surfaces, including molten solder
- All foreign particles and layers trapped in the melt
- solidified in it increase its transition resistance up to a complete cutoff of the current
Flow of current in electronics
In modern electronic equipment, the passage of current is complex by the fact that it is predominantly low-current. At low currents, the effect of transient resistances in current-carrying paths is much stronger. The result is a violation of the conductivity of cables and contacts fixed in hastily make cheap devices and electronic attributes.
How to work Alpha lead free solder wire properly?
To properly solder for Alpha lead free solder wire, you need:
- Clean them mechanically from the films listed above and dirt.
- Douse with molten solder in the presence of flux.
- Connect and solder with the addition of solder and flux.
What are solder and flux for?
Solder is an alloy of two or more metals with a low melting point. It serves for the connection of metals suitable for the technology by soldering. In the molten state, the solder has good wettability and high adhesion to the components to be joined.
The melting point of low-melting alloys is always lower than the melting points of the metals to be joined. Alpha lead free solder wire is the most common tin-lead solder, consisting of tin (61%) and lead (39%). It melts at tº = 183 ºC, for a reliable soldering connection it is common at tº = 250 ºC. For reference: the melting point of tin is 232 ºС, of lead - 327 ºС.
Ø Flux Alpha lead free solder wire
Flux is a chemically active component specially good for the metals to join. At the melting temperature of the solder, it dissolves oxide films, as a result of which its melt envelops the metal components to join, remaining between them as a mechanically strong and electrically conductive bridge. The most common flux common in electronics is pine rosin.
It dissolves well oxides on the surface of Alpha lead free solder wire and copper wires, is easy to wash off with alcohol and gasoline. There are different types of fluxes; they differ in activity and purpose.
Preparation for soldering wires
It consists of the following operations:
- stripping of insulation from wires
- stripping of soldered wire ends;
- tinning the ends of wires with solder in a flux environment
What is the role of oxides?
Oxides also prevent the solder from wetting the wire. Because of this, the tinning process is complex and lengthened in time, which leads to melting and shrinking of the polymer insulation of the wire. Some oxides on the wires in the solder melt dissolve after prolonged heating, but one cannot fully rely on this process.
In critical equipment, experienced installers always strip the wires mechanically before tinning and soldering in case of Alpha lead free solder wire.
How to Solder Copper Wires Correctly?
Soldering wires are made in the following options:
- So soldering of two overlapping wires
- soldering twisted wires
- Moreover, soldering wires to the contact pads of the printed circuit board
- soldering to component sockets or element pins
Process of soldering
With proper soldering of wires, the following operations must be performed:
- Cut the wires to the required length.
- Remove the plastic (woven) insulation with a knife or special tool to the specified length.
- Sand the bare ends with an emery cloth (knife).
- Tape the ends with flux Alpha lead free solder wire.
- Install the ends of the wires into the holes on the board or into the sockets of the components (in other cases: twist them or arrange the overlapping soldering process).
- Perform quick soldering (1-3 sec) with a soldering iron with solder and flux.
- Ensure the immobility of the connection when the solder solidifies.
- Rinse the soldering points with alcohol, gasoline with a stiff brush.
- The solder in the place of soldering should be shiny, tightly fitting the connected wires.
Errors allowed when soldering wires:
- Unreasonably Alpha lead free solder wirehas a long process (more than 2-3 seconds) or too high temperature of the soldering iron tip.
- This is fraught with melting of the PVC insulation of the wire with excessive exposure of its ends.
- The consequence is short circuits. Brazing with solder burnout has low reliability.
- The mobility of the ends to be joined during the crystallization of the solder during the overlapping soldering process.
- Any tremor or the slightest movement of one of the ends during solidification of the solder leads to a violation of its mechanical strength.
- The solder becomes dull. Such soldering is not allowed.
- Not enough flux, too high soldering iron temperature. These errors lead to ra
How varnish is removed?
The varnish removes from the wires mechanically – we clean them with an emery cloth or a sharply sharpened knife. If it is absent, mechanical stripping should not be abandoned - it also removes metal oxides that are non-conductive.