PCB007 Magazine


Issue link: http://iconnect007.uberflip.com/i/1401769

Contents of this Issue


Page 21 of 121

22 PCB007 MAGAZINE I AUGUST 2021 quite substantial, including derailed new prod- uct introduction, sub-par profit margins, unre- liable field performance, unnecessary rework, time-consuming redesign, and more. Com- pound this dynamic with the rapidly escalat- ing complexity of today's PCBs, and designers find themselves at a crossroads: Either contin- ue the prevailing "wait and see" feedback from manufacturing aer committing a project or, with little overhead, proactively and author- itatively evaluate DFM as an inherent part of the designer's normal incremental PCB design process. Some Design and Manufacturing Dependencies As components are placed on a board, the design immediately inherits several design and manufacturing characteristics, such as compo- nent spacing and solderability, flying probe ac- cess, and more. All these characteristics can influence the fabrication and assembly of the PCB. In addition, the design also inherits char- acteristics of the parts that are largely outside of the designer's control. Some of these char- acteristics include availability, cost, life cycle, performance-to-datasheet, quality, and reli- ability. All these represent touchpoints of risk that, le unchecked, can derail product real- ization. As PCB design progresses, manufacturing characteristics can be inadvertently created, such as acid traps and edge clearances that im- pact bare board fabrication but may have no impact on assembly. Likewise, without man- ufacturer-specific DFM checks at design time, boards can be fabricated to specification, yet cannot be assembled due to limitations of the target assembler. Any of these outcomes es- calates costs and delays new product intro- duction. Care must also be taken even when changing existing designs. If not properly re- validated, simply replacing a component can have unintended consequences, and can pre- vent reliable volume manufacture. is single change can impact an entire assembly run. e resultant cost and time risks can be quite high. In addition, while not typically associated with traditional DFM, component sourcing is becoming an increasingly significant area de- signers must pay attention to during the entire design process. If the components cannot be reliably procured, designs cannot be manufac- tured. The Value of PCB Design with Full Spectrum DFM Awareness e key to insulating designs from DFM is- sues is alignment of design rules and con- straints with the capabilities of board fabrica- tion and assembly providers. Once established, the rules and constraints constitute an over- the-shoulder auditor that is there to assure the manufacturability of the design. Issues created during design can be identified and corrected easiest at design time. e insurance that im- plementing DFM awareness within the design context provides can pay great dividends. Cap- turing manufacturing issues during the initial design also reduces the amount of time-con- suming, development-plan deviating redesign. is frees designers to start new, exciting de- signs rather than trapping them in a quagmire

Articles in this issue

Archives of this issue

view archives of PCB007 Magazine - PCB007-Aug2021