Fountain Selective Soldering Vs Wave Soldering
Wave soldering appears to offer a more cost-effective solution to soldering through-hole components, but has some deficiencies that fountain selective soldering systems address.
Of course, every manufacturer has to select the right soldering system or other equipment that best suits their needs. There’s no point in selecting equipment that has capabilities you don’t need, or that you can or ever will use.
While both systems have their positive attributes, it’s also that selective soldering machines more than warrant consideration for any application, including volume of manufacture.
Wave Soldering Is Simple, But Less Efficient
Wave soldering is the simplest method for being able to solder through-hole components at volume. It’s also been employed by manufacturers for longer than many selective soldering methods; some manufacturers still use it because of that lengthy track record.
A wave soldering system requires that boards be masked of fitted with an aperture prior to entering the soldering oven.
The board is passed over a solder tray, which is agitated to create a wave of liquid solder. The aperture/masking prevents contact with the rest of the board, and the joints are created on the bottom side and thereby solder through-hole components.
The process is simple, and if only one pass is required, it’s also fast. This allows manufacturers to produce at volume when needed, but this method also has a number of inherent compromises that can’t be ignored.
Selective Soldering Is More Efficient
Selective soldering systems, such as a fountain-based selective soldering system, uses tanks and nozzles to create fixed points of molten solder. The board is dipped on the fountain to create connections.
While selective soldering machines may take a little longer between products, the amount of time actually lost compared to wave soldering is either minimal or is less overall than the time to produce one board via wave soldering.
What some operations don’t account for is the necessary prep time involved in wave soldering. Every board has to be masked or fitted with an aperture so the rest of the board isn’t contacted.
Selective soldering doesn’t – typically, depending on the system – require any masking or apertures, so the board can enter the oven faster. So the overall time from when the board is taken to the soldering machine to when it leaves is either comparable or faster than wave.
Selective Soldering Is More Cost-Effective In The Long Run And Less Wasteful
Additionally, selective soldering is less wasteful than wave soldering systems, requiring fewer consumables and less downtime lost to regular maintenance.
Wave soldering systems require more nitrogen than selective soldering to ensure consistent soldering, so your gas costs will be higher. Selective soldering systems still require nitrogen, but consume less as the board typically spends less time in the soldering chamber itself.
Wave soldering systems also lose more solder to wastage, whereas selective soldering systems only use what they need to make the connections that are programmed into the machine by the operator.
Since selective soldering systems are also more precise, that will also mean that fewer boards need to be reworked and/or lost due to damage during the manufacturing process. These systems are also easier for the operator, as there is far more programmability.
With less downtime, and faster production of boards, the perceived advantage of volume due to wave soldering’s simplicity is either minimized or eliminated in practice.
While wave systems may be less expensive to purchase, they are less expensive to run and create additional inefficiencies that increase their cost in the long run.
Of course, every manufacturer is different and so are their individual needs. However, selective soldering systems offer far more advantages over wave soldering for assembling boards with through-hole components.