ACDi’s design team was contracted by an industry-leading R&D firm to fix a faulty design after their fabrication supplier found the board to be un-manufacturable. The board fabrication house was familiar with ACDi’s design work, and recommended that the client contact ACDi to fix the design.
The Challenge
After review, ACDi’s design team identified several issues with the layout that made this board extremely difficult or impossible to build. The major issue was the use of excessive blind and buried micro-vias. In order to build such a design, the board would be put through so many lamination cycles that the bottom layers would likely be damaged beyond repair. Even if the fabrication house was able to build the boards, the cost would have been several thousand dollars per board.
Further discussions with the client uncovered a common misconception – great software equals a great design. In fact, the opposite is true. It is quite possible, even with the best of layout tools, for a design to seem valid in the software but end up not feasible to build. That’s why it is so critical to have an expert PCB designer involved with the layout process.
The Solution
ACDi designers were able to re-work the design to eliminate the blind and buried vias entirely. At ACDi, designers start with standard through hole vias and only add blind, buried, or laser vias for extremely dense boards. Design for manufacture (DFM) and assembly (DFA) are key to creating feasible designs. As such, the ACDi design team has expertise in DFM/DFA practices, and has developed its own internal DFM/DFA guidelines based on expertise from both of their design and manufacturing teams.
The Result
In addition to moving to all through vias, ACDi reduced the layer count from 14 to 12 layers. The fabrication cost was cut by 90%, and with a much higher yield than would have otherwise been the case. Moreover, ACDi was able to design the board quickly, meeting the client’s quick-turn delivery needs.