When developing electronic assemblies, prototype boards must be assembled and soldered and components must be replaced from time to time. This happens especially after extensive tests regarding lifetime or function or if changes have to be made to the circuit. Due to the wide variety of component types and solder connections, it is therefore necessary to always have the right tools at hand. Because in accordance with the motto “time is money”, development stages must be fulfilled and products must be brought to market quickly.
Especially in such cases it must be taken into account that new casing moulds or components are assembled and soldered for the first time during the developement phase. Even more frequently, first assemblies are fitted with newly programmed or modified components. Particularly in the area of “Bottom Terminated Components” (BTC), major challenges can arise, especially when apparently simple designs such as MLF (Micro Lead Frame) or QFN (Quad Flat No Lead) are to be replaced on the sample assembly. The same applies to BGA (Ball Grid Arrays) and QFP (Quad Flat Packs), which are also indispensable in today’s assemblies.
Today’s homogeneous infrared underside heaters ensure that the boards are evenly preheated. For this purpose, hybrid heating heads are provided with a very balanced heat transfer, which gently heats the area of the component to be desoldered. The temperature should be regulated by using thermocouples on the top of the circuit board to enable a controlled and safe process. For close-to-production soldering, the assembly is preheated from below according to the selected soldering profile and the component is soldered in with a sensor-guided soldering process. All solder joints should receive the same amount of heat, within the temperature range that allows safe soldering of the assembly. In addition, the PCB material, but also the surrounding components, should not be subjected to unnecessary stress. In this way, solder joints can already be produced during the manufacture of prototypes, which are qualitatively comparable to solder joints from series production.
Do you have questions regarding this matter?
Your contact person: Jörg Nolte
Company: Ersa GmbH