The ideal temperature profile required for soldering an electronic assembly is subject to a number of factors, including the soldering paste, the components, the circuit board as well as specific production conditions. Sophisticated circuit boards in particular benefit from having a greater degree of flexibility provided by temperature variations between the heating zones. Rehm Thermal Systems offers just this with its specially developed temperature control system for the convection soldering of the Vision series.
Stable reflow soldering procedures with Rehm’s Vision series
Heating zones which can be regulated separately, a reproducible temperature profile, stable processes at the lowest temperature differences or homogenous heat input provided by special nozzle holes: the Vision series’ convection soldering systems by Rehm Thermal Systems provide the basis for the best soldering results with their optimum heat transfer properties and enable simple and reproducible profiling, including in the form of a saddle profile or linear profile. While a linear profile assembly is heated with exactly the same linear temperature increase, the saddle profile is gradually heated to the desired temperature according to predefined temperature ranges.
From temperature profile to temperature control system
In order to achieve the best soldering result, this temperature profile specifies how much and when thermal energy must be supplied to the respective assembly in accordance with a precisely defined schedule. The maximum temperature difference between the temperature levels in the adjacent zones is bound to technical and physical limits here. The systems also have increasingly better insulation to counteract rising energy costs so that less heat is released into the environment and instead remains in the system. While this usually isn’t a problem with a linear profile, it can be much more challenging to create saddle profiles.
The Vision series’ convection soldering systems by Rehm are therefore equipped with their own temperature control system that can be used to cool individual zones based on requirements. This makes it possible to achieve larger temperature differences between temperature levels. The respective zones in the preheating and peak range can thus be cooled to the desired temperature in an energy-neutral way by recirculating indoor air through a pipe system. This not only ensures exact temperature stability in the respective zone, but dramatically reduces the thermal influence from adjacent zones and ensures the optimum division of zones at the same time. The connection to system software is TCS’s major advantage. The indoor air supply is automatically regulated – instead of having to control the system manually, there is no extra work for the operator apart from having to set the temperature profiles. Cooling is thus based on actual requirements so that only as much cooling as is required is used.
Convection soldering with the Vision series
(Images: Rehm Thermal Systems)
The Vision series’ convection soldering systems are efficient, powerful and – depending on the respective version – suitable for different batch sizes in the automotive, consumer electronics or power electronics sectors, as well as many other fields. They don’t only feature increased process stability, but also focus greatly on energy efficiency, reduced emissions and operating costs with the help of integrated EC motors. A vacuum module makes it possible to carry out negative-pressure convection soldering processes in just one process: entrapped gas is reliably removed directly after the soldering process. There is no need for complex machining of the assembly by an external vacuum system; instead, the workpieces are transferred from the peak zones directly into the integrated vacuum process. The Vision series’ high-end system also effectively manages residue by using pyrolysis in the preheating zone, and has minimal downtimes, low maintenance requirements and intelligent traceability solutions.