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    Weathering the 0603 shortage, and designing for 0402 and 0201

    I am in a supporting role for a project to redesign some PCBs to use 0402 and 0201 package sizes, instead of the 0603.

    What are some of the most important component specifications to take into consideration when making a design change like this?

    • EMC
    • Current carrying capacity
    • Self heating
    • Temperature and Humidity


    Thanks for any feedback you can offer!

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    Re: Weathering the 0603 shortage, and designing for 0402 and 0201

    Maybe you have not listed the most important item in the case of resistors: Power rating. Anyway, without indicating which application these components are assigned to, the question becomes somewhat void; as for example, if these components are being used in circuits that do not interface with the outside world, and if the frequency of operation of the signal is not so high, there is not much to worry about which differ from the same requirements used in the specification of the components with the original sizes.
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    Re: Weathering the 0603 shortage, and designing for 0402 and 0201

    Also, if using these resistors to divide down high voltages, the smaller-size components will have a lower withstanding voltage.
    This is a specialized situation though, 99% of the time, it will be only power rating as Andre has mentioned.
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    Re: Weathering the 0603 shortage, and designing for 0402 and 0201

    Thanks for the feedback so far! Aside from the electrical specifications, how about from the perspective of layout, pad-size, tracing, etc...

    Could the adjustment of the pad size have any negative effects?
    Does the smaller form factor impact how the designer does the PCB tracing, or schematic layout?



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    Re: Weathering the 0603 shortage, and designing for 0402 and 0201

    Perhaps the most significant drawback from the layout side is at the assembly perspective, which increase the need of accuracy to place the components, along with the fact that - assuming you'll shrink the board dimensions aswell - being all the components populated within a smaller space, this will reduce the proportion of free area available to route the board.
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    Re: Weathering the 0603 shortage, and designing for 0402 and 0201

    Layout: bigger components may act as handy jumpers. Some traces may be routed under 0805/0603 components. I even use 0R 1206 for jumpers, avoiding 6 vias and leaving ground plane without any cuts.
    PCB bending: smaller components may be more resistant to PCB bending.
    Shock: Intuitively something very-very small is less likely to fall off from pcb if it is dropped. All these things must be googled to come some conclusion.


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    Re: Weathering the 0603 shortage, and designing for 0402 and 0201

    In general we've moved completely from 0603 to 0402 as our standard size. The downsides are what have been mentioned: lower voltage ratings, lower power ratings, more self heating (and thus specification drift), harder to probe and harder to rework.

    But the fact is 0402 is nothing special these days at all and even 0402 is starting to look pretty gigantic compared to modern leadless parts and BGAs.

    And don't underestimate the benefits of smaller components in layout. It's rare to have a design that's not space constrained so smaller components will translate into quicker/easier layout (pay the contractor less) or better layout with fewer compromises - critical circuits can be more compact.



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