From the design of a universal fit strobe light to the design of a custom application back-up alarm for an OEM. Superior Signals® maintains the same high standard from design through production. With close cooperation between the customer and SS® mechanical and electrical engineers, all aspects of a new product are reviewed at length prior to design.
Design
In the design of any new product, SS® uses a 3-D solid modeling CAD system. The concept of a new product is modeled in the CAD systems using 3-D color renderings (Figure 2). These models are then reviewed and the best features are selected for the optimum new design. As the customer, designer and engineers are able to view the model in this solid format, the time required to make costly physical models or prototypes is eliminated (Figure 3).
The CAD system also allows for the precise measuring of tolerances of all components and assemblies in three dimensions to eliminate errors in design. This ability to check the design prior to production improves quality, reduces the chance for errors in tooling, and improves manufacturability.
Detailed engineering drawings are automatically generated from the solid models (Figure 4). The models are fully parametric and associative with their respective drawings. Changes can be made either to the model or the drawing, and the other will update automatically. This allows SS® to go from concept to finished engineering drawings in the minimum time.
Manufacturing
Strobe light, flashing light, arrow light and back-up alarm assembly process begins with the preparation of the circuit board. Component leads are trimmed and bent to fit the lead spacing of circuit boards (Figure 5). Circuit boards then receive a solder mask to cover the holes that will not have components installed at this stage of assembly or holes that will not be soldered.
From here the circuit boards move to the automatic soldering process (Figure 6) that begins with a foam flux being applied to the bottom of the circuit board to clean and remove tarnish (Figure 7). This improves the solder joints between the component leads and the circuit board.
The boards then move to the preheat table where the preheat temperature and the amount of time the circuit boards remain at the preheat position are programmable product by product. The preheat table evaporates the solvents from the flux and brings the component leads to a temperature near to the solder temperature so that the boards experience less thermal shock when they are soldered ( Figure 8).
After preheat the circuit board moves to the solder bath. Once again the amount of time the boards remain in the solder bath, the temperature and the speed at which they are removed are programmable. From the solder machine the circuit boards move to a mass lead trimmer where all leads are cut to a uniform length. The solder mask is then removed and the circuit board moves on to the final subassembly stage. At this stage components too large to go through the solder machine are positioned on the circuit board, inserted and soldered by hand (Figures 9 and 10).
All circuit boards are visually inspected. Any corrections or touch-ups required are made and the boards move on to be tested. The test consists of functional as well as parameter tests to determine whether the circuit board will function properly. At this point any adjustments that need to be made to the circuitry are completed. Strobe light circuit boards then proceed to the ‘burn in’ test (Figure 11). This test is a four-hour functional test where all boards are operated at the highest rated voltage they are capable of operating under. Arrow light circuit boards are individually tested for proper function prior to final assembly (Figure 12). Back-up alarm boards are assembled in their housings with speakers and are individually decibel tested prior to potting (Figure 13).
The last stage on the production line is final assembly. Strobe light circuit boards are installed in either plastic or metal housings and the case lenses are attached. Arrow light circuit boards are installed in the appropriate control box. Function and control knobs are then installed. Back-up alarms are potted. All products go through a final operational test before being packaged with the necessary mounting hardware and instructions.
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