Engineering Design for Sustainability: Reduce Material Waste
One special moment of the From the Earth to the Moon mini-series “Spider” episode defines engineering for me. Astronaut Jim McDivitt and Grumman Chief Engineer Tom Kelly look at the newly completed lunar module called “Spider.” One says, “Isn’t it beautiful?” and the other says “Yes, it is.”
Most people thought that the LM looked like a bug.
Kelly and his team made a decision to design the lunar module from a different perspective. The lunar module only flew in space; none of the 50,000 technical documents for the project addressed aerodynamics.
Design changes occurred. The early lunar module design changed from a 22,000 pound, two-stage prototype that had seats and four large, bubble windows to a rather austere, lightweight version that had two smaller, cost- and weight-saving windows, no seats, and four—instead of five—landing pads.
Engineering and Design Work Hand-in-Hand
The lunar module epitomizes engineering at its best. Engineers studied early design problems and applied scientific and mathematical principles to respond to a need, solve problems, and move the project forward. Constraints ranging from the budgetary cost of putting large windows on the lunar module and spacecraft weight to finding the right fuels for a rocket engine that would ignite only in the environment of space resulted in project redesign.
The work that Grumman’s engineers accomplished with the lunar module illustrates the key factors of the design process. Those same factors apply to designs that target some product design as well as PCB design. The design process moves from describing the project need to visualizing the project. Product Design Specifications (PDS) describe what the product should achieve, how the technical aspects of the product align with customer needs, and establish design targets. As the design process develops, communication among and between teams increases. Product development leads to feedback about how the initial concept compares with the visualization and continues as design teams continually tweak the design so that it solves problems, responds to constraints, and aligns with a need.
Communication between teams may take the form of shared 3D files produced within PCB design software. As teams specializing in different areas of the project process work together, communication also involves merging the technical aspects of the product with the mechanical characteristics. Teams rely on their ability to import ECAD information into MCAD files and to see—in a virtual environment—how rigid-flex boards fit the project profile, if the proper component clearance exists, and if simulation results match with design rules. The quality and accuracy of inward and outward information sharing is key for a successful Final Design Specification (FDS). In the world of PCB design, all these tools help to successfully set the design for manufacturability (DFM) foundation.
Sustainability isn’t only for the stars, but certainly something of worry in the limited environment of space.
Sustainability Adds Balance to Engineering Design
The 7,000 Grumman employees who worked to develop the lunar module emphasized safety, reliability, and maintainability. They solved test failures that included propulsion-system leaks, stress corrosion on aluminum parts, and battery problems.
Today, engineering design integrates another approach that adds balance. Designing for sustainability considers all aspects of a project—from selecting materials to disposing of the product at its end of operational life—with an emphasis on environmental friendliness. Sustainability drives design and manufacturing techniques and factors into the use and maintenance of a product. However, each sustainability goal must also allow the production of a product at a competitive cost.
Sustainable sourcing begins well before a project moves even into the concept stages in that it includes the extraction of raw materials used to produce the PCB and the product along with the transportation of the materials. Responsible and sustainable sourcing seeks local suppliers to decrease the environmental impact of shipping materials long distances or seeks transportation that does not rely on fossil fuels. Sustainable sourcing also defines the use of recycled or reusable materials for a product.
The phrase “design for sustainable manufacture” has risen to prominence because of the need to reduce energy and material waste in manufacturing processes. Smart factories apply techniques such as using low-energy LED lighting systems, generating electrical power through renewable energy sources, water recycling, reusable materials, intelligent building management systems that control heating and cooling, and low energy evaporative cooling systems. Those factories also use computer technologies to digitally create and manage designs. Rather than build physical design prototypes, smart factories work through project stages and reduce the concept-to-project cycle times with 3-D digital prototypes. A PCB design team can transform images into 3D models and test the design with simulations.
Achieving sustainable use value occurs through reducing the amount of energy that a produce consumes during its lifetime. PCB design software plays a crucial role in designing for sustainability by optimizing the design process. Transferring files between ECAD and MCAD software allows design teams to reduce the mass and weight of products. The application of high density interconnections (HDI) and rigid-flex technologies allows designers to reduce the environmental impact of a product. In addition, the PCB design process may address sustainability through requirements for power efficiency.
Designing for sustainability can be as simple as incorporating solar power generators.
We could classify the lunar module as a throw-away design. After transferring back to the command module, astronauts jettisoned the first stage of the LM into space; The second stage remains on the moon. Designing for Sustainable Maintenance pushes design teams away from the throw-away product mindset and finite product lifespans. Instead, design teams focused on sustainable maintenance consider methods for producing extended life products that may feature replaceable components. In terms of PCB design, those methods rely on the capability to produce accurate circuit diagrams, PCB overlay diagrams, Bill-of-Materials, and Gerber files for the PCB and the capability to track and match components.
Recycling electronic products and PCBs can have a dramatic environmental impact. According to the Environmental Protection Agency (EPA), one metric ton of PCBs can contain 40 to 800 times the amount of gold and 30 to 40 times the amount of copper mined from one metric ton of ore. PCBs may also contain ceramics, silicon, aluminum, and silver. Designing for Sustainable Disposal involves recycling, reusing, and reducing the precious metals used for PCBs. The process of recycling extracts materials and reforms those materials into raw materials for reuse. Manufacturers have contributed to the capability to recycle PCBs by using lead-free solder and alternatives to toxic flame retardants.
Design teams can face decision-points when striving for design for sustainability. In some instances, a product design may require a compromise between size, weight, and energy consumption. Design teams may also need to decide what aspects of a PCB or product design reduce environmental impact.
Working through the challenges of sustainable PCB design can be made easier when using software tools built specifically for the design and analysis of innovative technology. Utilizing Allegro PCB Designer allows both the access to a smart layout tool and constraints manager that will assuredly give you the ease and authority to design efficiently.
If you’re looking to learn more about how Cadence has the solution for you, talk to us and our team of experts.