Notes on soft soldering - AH00.19-P-1000-07A
Model 124, 126, 129, 140, 163, 164, 168, 169, 170, 171, 199, 202, 203, 208, 209, 210, 211, 215, 216, 219, 220, 221, 230, 240, 245, 251, 414, 461, 463
General information
Soft-soldering is a process for creating an inseparable join between two or more metal parts using additional metals (e.g. soldering tin). The solder melting temperature lies below the melting temperature of the metals to be joined and is lower than 450°C.
The connection is created by wetting the joint locations with hot liquid solder, without melting the parts to be joined.
The joining procedure is assisted by using a flux, which releases surface oxides on the parts to be joined, eliminating and preventing surface films (e.g. greases).
Soft soldering materials
The alloy (mainly lead and tin) of the solder determines its melting point and thus the working temperature for the soft soldering process. Additives modify the properties. Silver components improve e.g. the surface and the joining properties.
The identification of the soft solders is according to DIN 1707.
Example:
L-Sn60PbCu2.
This solder consists of 60 % tin (Sn 60), max. 2 % copper
(Cu 2), the remainder is lead (Pb).
The melting point range is between 183°C and 190°C.
In the electrical system/electronic sector for vehicles, fast solders with a melting point range of approx. 180°C to 200°C should used. These solders are available in the form of wires. They have flux from resins dissolved in alcohol (e.g. colophonium) in their hollow center.
Soldering equipment
Soldering equipment with soldering tips that can reach a temperature of 250°C to 300°C are suitable for the repairs specified by DaimlerChrysler. The aim is to use automatic temperature-regulated equipment (e.g. soldering stations).
Preparation, general
- Use suitable work clothing.
- Use safety glasses.
- Use any available soldering fume extractors, aeration.
- Verify clamping devices and work surfaces.
- Clean soldering tips with small wet sponge.
- Protect surrounding working area from heat damage.
Preconditions for soldering
Soldering points must be clean, free of grease and oxides.