Bridging the market share gap between one's competitors is the driving force of many companies. The ability to react to market changes, coupled with the flexibility to bring new products to market faster, while meeting increased quality standards, all at lower cost, are the challenges facing today's electronics manufacturing businesses.

The concept of design for manufacturability (DFM) has resulted in a number of published references and case studies hailing its success in a variety of manufacturing environments. As an integrated component of the design process DFM bridges the gap between design and manufacturing considerations ultimately affecting the cost, performance, and how producible a product can be. Design for manufacturability requires a commitment to establish a model that systematically addresses manufacturing, assembly, testing, and performance concerns concurrent with product realization.

A company has to organize for and support the DFM discipline. Best manufacturing practices suggest a team approach that includes customers and suppliers. Design projects must be organized to address producibility. This can be accomplished by forming multi-disciplinary, integrated teams that facilitate communication between groups by including as much knowledge from key stakeholders as possible. Seven to ten member teams can effectively examine and disseminate the relevant information and provide problem solving resources while still allowing for unplanned changes.

DFM moves some risk to the initial phases of the design cycle where it is less likely to have a negative impact. It is crucial to identify and manage one’s exposure to risk by limiting the potential inability to achieve product goals and reducing the probability of a failure.

The impact of design decisions vary depending on the methods and materials in use at each process step. At the EMPF, the engineers specialize in electronics manufacturing and assembly, particularly at the packaging level. In the design and production of electronics, producability is best addressed before the project builds inertia. At its heart, DFM has the following guiding rules:

• Estimate the cost of manufacturing to identify cost reduction areas.
• Reduce the number and cost of components.
• Reduce the number of assembly operations by reducing the number of parts.
• Make the assembly operations easy to perform.
• Reduce the cost of supporting production.
• Consider the impact of DFM decisions.
• Employ Design Guidelines.
• Establish rules based on expert knowledge and lessons learned.
• Base guidelines on specific capabilities including equipment and human resources.
• Employ benchmarking by comparing best practices of others in related fields.

Properly implemented, DFM principles will reduce design time, decrease the cost of manufacturing, improve quality and performance, and reduce the cost of service and maintenance of the end product.

Let's look at some key DFM considerations in the electronics assembly design process.

DFM rules should be established for each process step. As a part of the design sequence, the design review should ensure that every manufacturing process step is known. The most rigorous implementations include validation of manufacturing process steps as the design is being developed.

Although a design may be limited to the components required for functionality, the proper selection of those components can have a great impact on the overall manufacturability and cost effectiveness of the design.

Electronic assemblies can be designed with a variety of components from different suppliers. Some components have leads that pass through holes in circuit boards. Some are attached by means of surface mount leads, while others are leadless. There are also components with hidden terminations that must be secured to assemblies with special adhesives.

Some components are compatible with standard epoxy circuit cards, while some call for the use of exotic materials where high temperature or high frequency performance demands preclude the use of standard circuit substrate materials.

As a manufacturer, consider the possible benefits of having your design group in sync with your manufacturing group. Your design engineers will know the requirements and limitations of your assembly processes and be able to compensate at the design stage, where 80% of a product's life cycle cost is set, instead of at the production stage where design changes become expensive. Designing for manufacturability to your specific processes should be the rule and not the exception. The EMPF can help achieve this goal through our Design for Manufacturability training.

For information on the EMPF’s DFM course, please contact the registrar at (610) 362-1320, or via email at registrar@empf.org.