Fully sealing electronics has obvious advantages: protection against water and dust, electrical safety, mechanical robustness.
With modern 3D printing, this can be achieved by embedding a PCB directly into the printed part, creating a continuous plastic shell with no connectors, buttons or cable glands.
The enclosure may be plastic, but whether this approach actually works is decided on the PCB design.
This post describes the core mechanical idea and then looks at practical ways to power such a sealed design, with a focus on how the PCB and the 3D-printed enclosure must be designed together.
Core idea: sealing by embedding the PCB
The fundamental concept is simple:
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The enclosure is printed as a single part
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The print is paused at a defined layer height
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The PCB is placed into a prepared cavity
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Printing continues and fully encapsulates the board
The result is a seamless plastic enclosure:
no joints, no screws, no glue lines.
This approach trades serviceability for robustness. Once the PCB is sealed, it is effectively permanent. That constraint strongly influences PCB layout, component placement and power strategy.
Why PCB design matters much more in sealed designs
In a conventional enclosure, the PCB is mostly an electrical concern.
In a fully sealed design, the PCB becomes part of a larger system:
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it defines where energy enters the device
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it determines optical, magnetic and RF interfaces
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it influences thermal behaviour
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it acts as a mechanical reference during printing
In other words: PCB and enclosure can no longer be designed independently.
Power option A: inductive power using PCB coils
One clean way to power a sealed device is inductive power transfer.
PCB considerations
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The receiver coil can be implemented directly as a spiral copper structure on the PCB
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Typically placed on the outermost layer, facing the enclosure wall
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The coil area should be free of copper pours, vias and nearby high-loss materials
Interaction with the 3D-printed enclosure
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Plastic is magnetically transparent, which works in our favour
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Wall thickness above the coil should be kept thin (around 1-2 mm)
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No metallic inserts, screws or pigments near the coil
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The PCB must be mechanically fixed during printing so coil alignment is repeatable
Inductive power works best for low to moderate power levels and fixed installations where an external transmitter is available.
Its main advantage: no energy storage and no ageing components inside the sealed volume.
Power option B: solar power through a printed window
Another practical approach is harvesting light through the enclosure using a transparent printed window.
Mechanical integration
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The transparent area is modeled as a separate object in CAD → see Link
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Wall thickness in the window area should be minimized (typically 0.8-1.5 mm)
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Printing the window surface directly on the build plate produces a smooth, low-scatter finish
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The window should be slightly larger than the solar cell to allow for placement tolerances
PCB considerations
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The PCB defines the exact position of the solar cell relative to the window
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Short, low-loss connections from the cell to the power circuitry matter
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The PCB outline often becomes the reference for window placement in the enclosure
Two common variants are used in practice:
Solar + battery
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A rechargeable battery bridges dark periods
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Suitable for intermittent loads and outdoor use
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PCB design must consider charging, protection and thermal constraints
Solar + supercapacitor
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No battery ageing
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Much lower stored energy
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Device operation becomes light-dependent
In both cases, power budgeting and sleep modes are critical. The enclosure may be sealed, but energy still has to come from somewhere.
RF and antennas behind plastic
Many sealed devices also communicate wirelessly.
From a PCB perspective:
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PCB antennas work well behind plastic, but spacing and ground clearance matter
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Copper placement under and around the antenna becomes more critical
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Antenna orientation is fixed once the PCB is embedded
From an enclosure perspective:
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Plastic thickness and infill influence RF behaviour
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Transparent or thin regions can double as RF windows
In sealed designs, the enclosure material effectively becomes part of the RF environment.
Thermal reality of sealed electronics
A sealed enclosure eliminates convection.
Implications for PCB design:
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Losses that were previously negligible may become critical
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Copper areas can be used intentionally to spread heat
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Power components should be placed near thinner wall sections when possible
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Hotspots directly under thick plastic should be avoided
Environmental protection always comes with thermal trade-offs.
Manufacturing, testing and one-shot designs
Once a PCB is sealed into a print:
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rework is impossible
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probing is impossible
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connectors are gone
This feeds directly back into PCB design:
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test pads must be used before embedding
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programming may need to happen once, or wirelessly
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errors become permanent
This is not a disadvantage, but it must be a conscious design decision.
What this approach is not
To keep expectations realistic:
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this is not a certified IP-rated enclosure
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it does not replace industrial overmolding
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it makes no lifetime guarantees
These are practical design approaches that have proven useful in real builds, not formal enclosure specifications.
Takeaway
The core idea is sealing electronics by embedding the PCB directly into a 3D print.
Inductive power, solar cells, batteries and supercapacitors are simply different ways to make that sealed design usable and all of them depend strongly on PCB design choices.
In fully sealed electronics, the enclosure may be plastic, but the success of the system is decided on the PCB.
