Method for soldering surface-mounted electronic components (SMDs) onto printed circuit boards

摘要

In soldering devices in which one or more rows of connecting legs (3) of an electronic component are soldered onto a printed circuit board (2) by means of one or more soldering bit electrodes (1) and electrical resistance heating, a force is exerted on the connecting legs (3) via the soldering bit electrode (1). In this case, various types of methods are known for the variation of temperature and force with time. In order to prevent a connecting leg (3) sliding off a solder deposit (4) or off a connecting spot (5) and in order to prevent individual connecting spots being excessively stressed, the force on the connecting legs (3) is increased from an initially low force (F1) in stages to the maximum force (F24) when the melting temperature (T2) is reached. After a temperature (T3) and the maximum force (F24) have been held for a certain time, the force is reduced to a residual force (F3) until the solder material has completely solidified. <IMAGE>