Issue link: https://iconnect007.uberflip.com/i/1496727
60 DESIGN007 MAGAZINE I APRIL 2023 layout design. How do you evaluate whether a small change will increase a PCBA's final cost? Here, I list the most important factors in the design that can impact the manufacturing cost. e first way to keep the cost low is to use a surface mount device (SMD). Electronics manufacturing production is expensive, and each surface and machine should be utilized efficiently. Having only SMDs in your design means it is not necessary to use another line just for the through-hole devices (THDs). is will save time in production and will reduce the risk of quality issues. e SMDs are placed by the pick-and-place machine and soldered in the reflow oven, but for THDs, the process is very time consuming. If THDs cannot be avoided, make sure the components are designed for pin-in-paste and can be assembled on the SMT line. is will keep the manufacturing price low because it is not necessary to use special machines and all the components will be assembled on the same production line. Aer you have managed to have just SMDs on your board, let's try to keep all the compo- nents on the same side. is will make the guys in production very happy, and you will get a discount. Having one single-sided population will reduce the production time and some tool- ing costs can be eliminated. If a one-side popu- lation is not possible due to product-specific reasons, make sure the number of components is balanced between top and bottom sides. The SMDs are placed by the pick-and-place machine and soldered in the reflow oven, but for THDs, the process is very time consuming. Having the same cycle time for both sides will reduce the manufacturing cost. Another idea in "design for cost" is to reduce the PCB surface because the board is expen- sive. You should increase the component den- sity and avoid making the PCB with the same dimension as the product. Don't fill the empty space inside the product with the PCB. If the product is a sphere with a circular base, add a square PCB inside. A complex PCB outline will increase the cost: rectangular PCBs are preferred by manufacturers because they can better optimize the panel usage. PCBs are not assembled as singles, but as part of a panel with multiple PCBs. ose panels can be better optimized if the PCB outline is a rectangle, and less material will be wasted. Better to keep the nice design for the outside part of the product and place rectangular shapes inside. e bill of materials (BOM) cost is influ- enced by the component types and quantity. e next cost reduction factor is reducing the number of unique component types. Instead of using 50 different resistor types, it's better to add 60 resistors from just 10 unique part num- bers. is action will reduce both the inven- tory cost and quality issues during assembly. Exotic components are expensive and hard to find. During the design phase, it is recom- mended to check component availability and to adapt the schematic if one component is not available. ere is no reason to push your sup- plier to find a non-standard component. It's not just that delivery time will be high, but the BOM price will increase dramatically. Having a cost calculation feature as part of the design tool will give you the flexibility to make quick decisions. A small design change will be evaluated in real-time, and the design- ers can decide what to do next. is tool should cover component price, PCB fabrication cost, and assembly costs. Of course, some settings are necessary and variable inputs will be collected from the design tool. To eval- uate component cost, the system will be con- nected to a real-time component availability