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Design Steps OverviewElectronic product development requires a method to advance the product from a concept into a finished product. This strategy requires numerous consecutive steps or stages to direct the product development. Specification and Evaluation Stage: Section 1: The product specifications generally include the following information:
Click here for an example of a product specification> Example - Product Specification Section 2: Step #1 - Specification and Feasibility Study: The design group evaluates the technical requirements and feasibility of the product. Then a preliminary product specification is drawn up using all the information obtained above. Step #2 - Circuit Design: In this stage of development, the circuit is designed and preliminary schematics are drawn up. Depending on the circuit complexity, it may be checked on a circuit simulator to verify the design. If the circuit uses an embedded microprocessor or an EPLD the SDD (software design document) is prepared. Using this documentation, the code is written to conform to this spec. Software development works concurrently with the hardware in this phase. During this stage, the assembly drawings are started and parts are ordered for the prototypes. Step #3 - Bread boarding: A working model or portions of the circuit are built on a breadboard to verify circuit operation. Depending on the complexity of the circuit only portions may be built and tested due to the labor required or noise problems associated with hardwiring a breadboard. In these situations, it may be beneficial to move directly to the PCB layout and prototyping layout stages of development. The project may be more cost effective to make several board tooling changes rather than spending the labor and time required in bread boarding. Any problems would be ironed out on the next board revision. Step #4 - PCB layout and artwork: After the circuit is designed, we proceed to the PCB artwork, component layout, and mechanical and drill drawing documents. After this work is completed, the artwork is forwarded to the PC board manufacturer. Step #5 - Prototypes: Usually 2-3 units are built to evaluate the design. The bare boards are assembled with parts using the component layout drawing. The boards are then tested for proper operation and the units are wired and assembled into the enclosure using the assembly drawings. Any design changes required are corrected and the information is sent back to make changes in the documentation for the final release. These prototypes are not sold but are used for in-house evaluations and testing. Step #6 - Qualification Testing To assure the quality of the product it is subjected to a vigorous set of tests to verify that it's performance, meets or exceeds the product specification. The quantity and the variety of testing will change from one product to another and is outlined in the QTP (quality test procedure). Sometimes due to cost restraints, companies may wish to bypass this stage with the reasoning the product was verified enough during the design and bread boarding stages. If you choose to bypass
quality testing, please consider the following possible circumstance: Unfortunately, you failed to test your product under the extreme conditions that is listed on your data sheet. Your decision against testing your product was based on the assumption that all the components used are well within the temperature ranges listed on the vendors data sheets. Now since you received all these returns you decide to evaluate the problem under extreme conditions and indeed all the units failed. The problem was traced not to a component failure but to a clearance problem. Under hot and cold conditions the expansion of the case caused a board connector to flex causing an open condition. Now you must recall 100,000 units to correct the problem, ouch! Environmental and/or electrical qualification testing of your units is the only way you can guarantee it meets spec. Pencom Design can also design the test equipment for production requirement. Step #7 - Pre-production Pilot run In this stage, 10-25 units are produced. All the documentation is completed and these units are assembled in a production environment to verify all the drawing and procedures. The ATP (acceptance test procedure) is followed to confirm the proper operation. Step #8 - Production: All documentation is completed, checked and put under version control. The product is released for full manufacturing and all documentation is compiled and presented to the customer. Email us at the design department to discuss your product ideas.
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