#Good examples for pcb altium designer manual#

Minimum external dimensions for a soldering nozzle in multinozzle dip soldering processes are 5 x 8 mm. To perform a reliable soldering process, the minimum allowed inner diameter of a single miniwave soldering nozzle is 3 mm, which corresponds to an outer diameter of 4 mm. Another issue is solder balling, which can also be reduced by a proper board design or special soldering nozzle design. A special soldering nozzle design can also help to minimise solder bridges. To reduce the risk of solder bridging, mainly the pitch between the component leads and length of the leads need to be considered. Measures can also be taken to improve hole fill, such as correct component lead length, a proper ratio between the pin diameter and the via, thermal decoupling etc. To avoid problems during selective soldering processes, PCB design rules are mainly related to clearance areas around the solder joints. Typical cycle times range between 1 minute and 10 minutes.īoth processes demand different design rules, to some extent. This offers high flexibility and less restrictions with regard to board design however, depending on the number of joints to be soldered, single miniwave processes exhibit a longer cycle time.

Selective soldering as a single miniwave process (Figure 1) can be performed in either a drag or a dip soldering mode and allows soldering at an angle. In general, one has to distinguish between the different selective wave soldering processes. The solder’s pull-off behaviour, which is influenced by several factors, is what is mainly responsible for reliable soldering results in the selective soldering process. In addition, solder balls can cause difficulties. In many other cases, solder bridges and poor hole fill are the main reasons for faults. Most frequently a selective soldering process cannot be realised because of insufficient clearance between the solder joint and neighbouring components, such as SMDs which might be washed off during the process or housings of other leaded components which could be touched and damaged by the solder nozzle. With many practical examples, this article gives a detailed explanation of the individual points which should be considered in the selective soldering process, with regard to assembly design and solder nozzle technology. Additional innovative features, such as debridging knives for example, can effectively avoid the formation of solder bridges, especially in the dip soldering process. The design of the soldering nozzle – for example the shape or diameter – and the soldering nozzle technology used – such as wettable and non-wettable soldering nozzles – play a role here. Moreover, by choosing the correct soldering nozzle, one can avoid the formation of soldering faults in the automatic selective soldering process. The distance between the individual pins, as well as the length of the pins, are likewise to be taken into account. The distance between a pad to be soldered and an adjoining one that is not to be wetted, also plays a role. For example, the shape of the pads and their distance in relation to each other can mitigate or, with proper design, exclude the formation of bridges. The target, therefore, has to be a zero-fault selective soldering process.Īn appropriate printed circuit board design is of the utmost importance here.

#Good examples for pcb altium designer manual#

Special focus has to be put on lead-free applications, as manual repair soldering processes can cause enormous thermal problems. Hidden costs, such as productivity rates, operator training and damaged assembly costs have to be taken into consideration as well. In addition, densely populated multilayer boards and miniaturised, high-pin-count, fine-pitch devices cannot be efficiently repaired with high quality. Manual repair soldering that is expensive, time consuming and cost intensive is already unacceptable due to the required quality and reproducibility of the whole manufacturing process. For companies producing electronic equipment, it is therefore of extreme importance to reduce production costs whilst maintaining a consistently high quality level of the manufactured products. The globalisation of markets results in stronger competition with clearly noticeably cost pressure. Reiner Zoch, Heike Schlessmann, SEHO Systems