I'm looking for a CAD design for a concept I've come up with. My design is to create a small PCB with dimensions not exceeding (if possible) 20mm x 30mm x 6 mm. The small LED is powered by battery and is energized when a button is pressed. The LED connects to a DIP switch to show 1-99. A small button is depressed to turn on and display specific LED numbers.
I'm not an engineer, if this design is not feasible let me know. I'm hoping it's straightforward.
The following is the components to include in the CAD design:
• PCB Size: ~30 mm x 20 mm (1.2 in x 0.8 in)
• Height/Thickness: ≤6 mm (0.24 in)
• Total Volume: ~30 mm x 20 mm x 6 mm (3.6 cm³), Component Selection for Compact Fit
1. Battery: CR1220 coin cell (12.5 mm diameter, 2 mm thick, 35 mAh, 3V).
o Use an SMD coin cell holder (~10 mm x 2.5 mm footprint, ~2.5 mm height).
2. Microcontroller: ATtiny20 (QFN-20).
o Size: 3 mm x 3 mm x 0.8 mm (vs. ATtiny85 SOIC: 5 mm x 4 mm).
o 12 I/O pins (sufficient for 7-bit DIP + button + LED).
o Low power, programmable via ISP.
3. LED: 0603 SMD LED (1.6 mm x 0.8 mm x 0.6 mm).
o Ultra-compact, available in various colors.
o Current-limiting resistor: 220Ω (0603, 1.6 mm x 0.8 mm).
4. Push Button: SMD tactile switch (3 mm x 3 mm x 1.5 mm).
o Low-profile, momentary switch for LED activation.
o Pull-up resistor: 10kΩ (0603).
5. DIP Switch: 6-bit ultra-miniature SMD DIP switch (e.g., C&K SDA06H0SBR).
o Size: ~8 mm x 3 mm x 1.5 mm.
o 6 bits cover 1–63; for 1–99, use a 7-bit switch (~9 mm x 3 mm x 1.5 mm, e.g., Omron A6S-7102-H).
o Each switch connects to a GPIO with a 10kΩ pull-up (0603).
6. Capacitor: 0.1µF decoupling capacitor (0603, 1.6 mm x 0.8 mm) for MCU stability.
7. PCB: Custom double-sided FR4 PCB, 0.8 mm thick.
o Dimensions: 30 mm x 20 mm x 0.8 mm.
o SMD components on both sides to optimize space.
o Thin PCB reduces total height.
The designer that meets the overall requirements will be the winner.
I need the designer to meet my specifications. If it's not possible, please let me know and I may be able to edit the requirements.
Please ensure the LED’s are two (.75 x .5 x .31 inch) side by side 7-segment LED’s. Please position on the upper right of the PCB and include an 8 position DIP switch.
Lastly, I would like to give this design to a manufacturer to produce a sample. So, all of the resistors, capacitors, etc. need to be included in the design. I prefer a single side PCB please.
khriss
Designer