4 layers41 × 21 mm Slimmy, the printed circuit board in 3D

Slimmy

Slimmy is a USB 3.0 TF-Card Reader. 1. Why I made this? Because I wanted to make Type-C USB 3.0 device.

Size: 41 × 21 mm
Copper layers: 4
Thickness: 1.6 mm
Parts: 24
Nets: 37
Pads: 116
Tracks, vias: 255, 26
Pours: 1
Routed: Yes
KiCad: KiCad 10.0 (file 20260206)
Created: 28 Jun 2026
Updated: 15 Jul 2026

Overview

Slimmy is an open-source printed circuit board by devisunofficial, from the devisunofficial/Slimmy repository on GitHub. It is a 4-layer board of 41 × 21 mm with 24 parts on 37 nets, routed with 255 tracks and 26 vias.

It is built around the GL3224-OIY04 and TYPE-C-31-G-02. Its parts include 18 capacitors, 2 resistors, 2 ICs and 1 crystal.

Main components

README

Readme.md

Slimmy

Slimmy is a USB 3.0 TF-Card Reader.

Why I made this? Because I wanted to make Type-C USB 3.0 device.

Features:

USB 3.0 TF-Card Reader
True USB 3.0 controller is used

CAD Model:

Even though there is no Case or anything, here is PCB in 3d View Hub-3D

PCB:

Here's my PCB! It was made in KiCad.

Schematic : Complete Slimmy PCB Footprint :

Firmware Overview:

No FIRMWARE ;)

Assembly :

Done By JLCPCB because I don't have Hot plate!!

BOM Table

Name	Use	Quantity	Distributer
GL3224-OIY04	USB Hub Controller	1	JLCPCB
PCB	Main-Circuit	1	JLCPCB
USB-C	Up-Stream Port	1	JLCPCB
TF Card	I don't have TF Card to use USB 3.0	1	Amazon

Parts

Qty	Value	Footprint	References
7	0.1uF	Capacitor_SMD:C_0603_1608Metric	C1, C6, C7, C9, C11, C13, C15
5	10uF	Capacitor_SMD:C_0603_1608Metric	C2, C5, C8, C10, C12
2	0.1uF	Capacitor_SMD:C_0402_1005Metric	C17, C18
2	33pF	Capacitor_SMD:C_0603_1608Metric	C3, C4
2	4.7uF	Capacitor_SMD:C_0603_1608Metric	C14, C16
1	5.1k	Resistor_SMD:R_0805_2012Metric	R1
1	680	Resistor_SMD:R_0805_2012Metric	R2
1	GL3224-OIY04	lcsc_footprints:C157357_HQFN-32_L5_0-W5_0-P0_50-BL-EP3_0	U1
1	HC-49SMD 25MHZ 20PF 20PPM	lcsc_footprints:C14872_HC-49S_L11_4-W4_8	X1
1	SD Card	lcsc_footprints:C5184837_TF-SMD_TF-PUSH	U2
1	TYPE-C-31-G-02	lcsc_footprints:C530606_USB-C-SMD_TYPE-C-31-G-02	USB-C-Male1

Questions

How big is the Slimmy PCB?

It measures 41 × 21 mm and has 4 copper layers, 1.6 mm thick.

What parts does the Slimmy use?

24 parts, built around the GL3224-OIY04 and TYPE-C-31-G-02. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.

Where can I download the Slimmy KiCad files?

From the devisunofficial/Slimmy repository on GitHub, at the commit this page was made from: the board is Slimmy/Slimmy.kicad_pcb and its schematic Slimmy/Slimmy.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the Slimmy design in my own project?

Its repository states no licence, so its author keeps all rights: ask devisunofficial before reusing the design.

Project files

Show this board on your page

A live frame, for any web page

<iframe src="https://pcbkit.io/embed/boards/devisunofficial-slimmy" title="Slimmy in PCBKit" width="100%" height="480" style="border:0;border-radius:12px" allow="fullscreen" loading="lazy"></iframe>

A picture

<img src="https://pcbkit.io/embed/boards/devisunofficial-slimmy.jpg" alt="Slimmy" width="1200" height="900">

A picture that opens the board, for a README

[![Slimmy](https://pcbkit.io/embed/boards/devisunofficial-slimmy.jpg?size=s)](https://pcbkit.io/boards/devisunofficial-slimmy)

Source

Repository: devisunofficial/Slimmy
Board file: Slimmy/Slimmy.kicad_pcb
Commit: b7ea63a
Licence: Not stated

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