Electronic military assemblies are used for military hardware. Compared to commercial requirements, these assemblies often go through more intense field conditions. Due to the harsh environments subjected to, the assemblies must be designed and built to surpass what typical assemblies can do. Field conditions are usually difficult and to accommodate, the assemblies have to meet tough demands.
Many critical mission operations depend on the reliability and consistency of electronic military printed circuit board assemblies and as such, they have to be engineered and manufactured to perfection. In order for power devices, communication devices, and various types of peripheral support equipment to provide reliable service, they have to withstand contamination caused by water, dust, and sand.
For a portable power supply to meet set criteria, several unique challenges were identified specific to quality, design, process, and diagnostics. For instance, engineers recognized the need to protect the power source from water seepage that would ultimately lead to an issue of corrosion.
The printed circuit board, which is an intricate part of the interface, is responsible for transmitting power. In addition, the board provides a mechanical sealing surface that ensures a watertight power unit assembly. With the boards being installed toward the beginning of the unit assembly phase, unless they are 100% watertight a large amount of the unit would have to be disassembled and a new board replaced.
Experts have been able to correct the problem through the use of fluted pins and improved soldering processes. The new specification requires a solder to fill in the barrel of the hole, which in turn creates an excellent watertight seal on the underside of each pin. In addition, solder is not allowed on the pin’s topside or around the circuit board’s perimeter where a rubber gasket serves as a surface that prevents water from leaking into the power supply.
Originally, electronic military assemblies were created using more conventional wave type soldering, which means the entire printed circuit board was subjected to the soldering operation. As a result, the dancer wave that involved solder to be applied onto the glued surface mount capacitors, used solder migration underneath the soldering fixture where the board was held during the soldering process.
Because of this, a somewhat rough bead was left around the perimeter of the annular ring that to create a flat sealing surface had to be taken off by hand. The rework took a long time and consisted of tedious work.
By reducing the dancer wave aggression and using laminar wave as a means of supplying solder coverage to pass specifications, solder coverage was not completed. While specifications were met, various problems arose. By changing the method of soldering electronic assemblies, problems were fixed and eliminated. Today, the military has electronic equipment they can count on when it matters most.
