It is based on the massive vision of every design: the state-of-the-art functionality, sleek designs, and unconventional elements. However, between such a vision and a successful product is an important step that will lead to either success or failure Design for Manufacturing (DFM). Using DFM principles in the initial phases and continually makes the engineers cut down the costs, increase the speed of time to in-market and enhance the product reliability significantly. When architects use the gained understanding of DFM, it is possible to develop a practical design that can be turned into a manufacturable product that will be produced by PCB fabrication teams at scale perfectly.
Design for Manufacturing Design for Manufacturing is a concept designed to create a unified platform for both the design and manufacturing processes of products and layers.<|human|>What is Design for Manufacturing? Design for Manufacturing is a concept created to establish a comprehensive platform on designing and manufacturing products and layers.
DFM is a methodical way of creating PCBs taking into consideration manufacturing procedures and constraints. Instead of considering fabrication as a post-design issue, DFM incorporates the manufacturing expertise in all their design decisions- placements of components, trace routing, selection of material used, and also layer stacking. It is think-ahead and does not require any fee, as opposed to such proactive measures as redesigns and respins which cost thousands each.
The inherent rule: design choices made in layout have a geometric cost ramification. It requires little effort to change requirements on the schematic design, less work in the layout, and none at all after manufacturing has commenced, thereby incurring costs on the delay of entire production.
Three stages of successful DFM
Phase 1: ACB Interim Phase Correctly layout PCB with footprints
Start with right component footprints of manufacturer capabilities. Smaller than they should be, to the wrong size of via, or the wrong foot print giving an outcome that cannot be exploited by your PCB manufacturer will cause an immediate manufacturing failure. Check the footprints of the components used by you should be reliable and checked ones then layout starts.
Phase 2: Planning of Strategy Components
The manufacturing cost and assembly efficiency together with the reliability of the products are directly influenced by the component placement. The high-power units are supposed to be placed to use the natural heat dissipation paths minimizing on costly thermal management frameworks. Group components as close as possible to reduce trace lengths to minimize electromagnetic interaction and also possibly to do away with expensive shielding.
In case of SMT (Surface Mount Technology) assembly, the maintenance of the spacing around the BGA and the high-density component regions are required. Pads must not be exposed to silkscreen- this disrupts the solder paste printing as well as decreasing solderability.
Phase 3: Appropriate Trace Route and Routing Wire Standards
Trace Width Trace should be given a trace spacing that has a direct impact on the manufacturability factor and the cost. Design is based on your manufactures minimum capabilities, and an overrun. You have a manufacturer with a minimum trace width of 0.2mm, design with 0.25mm width to allow drilling errors and etching errors.
Trace spacing to trace width ratio must be at least 3 -4 trace-width of normal design, or at least 10 mils to the trace per-IPC-2221. Applied to pads included in large areas of copper- thermal reliefs – thermal relieved pads are much easier to solder and still provide thermal contact.
Critical DFM Design Rules
Standardize Pad sizes and Via sizes
Select size of standard via in accordance with your manufacturer. Too small vias increase production flaws and add up to expenditure. The pcb design and fabrication services that you have contracted must state their desired drill sizes; by designing to this standard, the cost of tooling is less and their yield is higher.
Optimize Layer Stackup
Select number of layers according to real need of electricity not randomly. Each extra layer adds 20-30 percent in terms of cost in materials and complexity in production. Make power and ground planes continuous and ensure that they are well connected to reduce impedance and noise, this single choice can oftentimes remove an entire set of signal integrity issues.
Design for Testability (DFT)
Insert test points of critically required signals, power rails and ground networks. These provide quick testing and diagnosis of failures in the production lines. In the absence of DFT, failure debugging can take hours and inflate the cost of the production line in an extreme fashion.
Thegge, Letrans, and Williams (2007) advise manufacturers to take into account manufacturing tolerances in the design phase of modeling aircraft systems.<|human|>Consider Manufacturing Tolerance Accounting Accounting Many designers might not consider manufacturing tolerances when modeling aircraft systems, which is unwise, as recommended by Thegge, Letrans and Williams (2007).
Nothing is flawless manufacturing process- Trace width0.01 fluctuation, drill holes swervedaround.005 inch and layer and lifetime shifted during lamination. Effective designs implement these variations by using a low feature size and spacing. Design features should not necessarily be to manufacturing capability boundaries.
Cost Reduction Through DFM
The DFM principles applied often lower the cost of PCBs by 20-40 percent without degrading or decreasing the performance. Namely, some of the strategies are:
- Reduce the number of layers: standard 4-layer boards use very little less money compared to 6 or 8-layers. Consider that your design may actually need more than the required number of stackup layers, or it might be the case that the number of few stackup layers can be optimally stacked up.
- Standardize Component Choices: MB has the opportunity to buy in bulk since all designs will use the same component values, and this makes it easier to write assembly code as well.
- Efficient Panelization: Making boards to fit standard panel size also maximizes the use of material eliminating wastes and unit costs.
- Standard Drill Sizes: The drill size can be of the manufacturer preferred drill size to save on custom tooling and increase the yields due to the established manufacturing process.
Cooperation with the Manufacturers
The best DFM is achieved through early partnership with the pcb fabrication supplies company. Discuss with the final decision on designs:
- Minimum trace widths and spacing ability.
- Through dimensions and desirable forms.
- Preferences and constraints on the materials.
- An economical cost of design decision.
- Tolerances of manufacturing and effect on signal integrity.
This discussion tends to highlight cost-cutting avenues as well as seeing through that your design is in line with what you can build.
Common DFM Pitfalls to Avoid
Inadequate organization in terms of Annular rings: The copper ring ring around vias should be effective in means of plating. Minimum annular ring widths are specified under IPC-A-600 – a violation of this puts weak connections in place.
- Bad Solder Mask Clearance: The pad area generated is either too small or too large based on what could be considered a problem with solder mask clearance; too small and the squidging of the paste; too large and the paste is bleeding.
- Poor Thermal Relief Design: Thermal reliefs of insufficient size render the use of pads ineffectual in terms of hand-soldering effectively, thus, preventing pads reuse and repair.
- Overlooking Aspect Ratio Limits: Depth to diameter (depth): the aspect ratio should not be more than 10 to 1 or plating becomes unpredictable and costly.
Conclusion
DFM is the point that unites engineering vision and reality of production. Knowing manufacturing limitations, working with your fabrication partner, and being consistent in using DFM concepts will make you create designs that can easily be manufactured at low costs and at an opportune time. The knowledge and discipline invested in DFM knowledge come back in the form of some increased yield, fewer respins and also through decreased time to market, to make the theoretical benefits a reality in business.
