Techniques For Soldering Key Switches
Preferred Techniques For Soldering Switches With Thermoplastic Housing
Type of Iron:
The iron used should be one having a temperature stabilised bit diameter of 2.5mm or less, with a 40W heating element.
The temperature should be set in the band 275°C - 400°C for normal tin/lead solder having cored flux.
Method To Be Used:
The two components, e.g. tag and wire should be cleaned and pre-tinned to ensure a good joint. The soldering tip, when up to operating temperature, should be cleaned on a moistened cleaning pad. Excessive cleaning on a moistened pad will cause a non temperature controlled bit to drop temporarily in temperature which is undesirable for good jointing. Then re-tin the soldering iron tip with a small amount of cored solder. Apply the iron to the top of the solder tag and bring the wire and tag quickly up to the temperature at which the solder flows freely, apply a small quantity of cored solder to the joint until it is correctly covered. Remove the soldering iron from the joint immediately when it is made.
The operation should be effected in 7-8 seconds.
It is important that no side loading is applied to the termination whilst the soldering iron is in contact as this may disturb the location of the terminal within the switch body.