How to make your own PCB business card

Business cards are often used in business activities, but traditional paper business cards cannot attract the attention of the other party. This article FS Technology will teach you to make a beautiful and practical pcb business card, which will make you stand out from many competitors.

Homemade PCB Business Cards

What you will learn from this project:

  • Simple PCB Business Card
  • High-end pcb business card with nfc

Required tools and skills

Essential tools:

  • Soldering Iron
  • Hot Air Rework Tool
  • Solder paste
  • Soldering flux
  • Solder wire
  • Tweezers
  • Cross-lock tweezers
  • Isopropyl Alcohol
  • Cotton swabs
  • Toothpicks

Optional tools:

  • Smoke exhauster
  • Ornate glass
  • Phone with NFC
  • NFC Chip 1kb

Required skills:
  •  SMD soldering skills

Bill of Materials:
  • Printed Circuit Board
  • 220 nF capacitor
  • 47Ω resistor
  • LED

Simple printed circuit board business card

Making PCB schematics

Whether you are a professional PCB designer or a beginner, FS Technology recommends you to use EasyEDA, and convenience is the reason why we recommend it. . EasyEDA has a built-in simulator for signal measurements, and you can find the required component circuit schematics in the EasyEDA PCB library.

  • Import your pattern into layer 22 “bPlace” and it will appear on the PCB’s silkscreen, above the black solder mask.
  • Introduce light on layer 16 “Bottom” which will be seen as copper traces covered by black solder mask.

The manufacture of PCB business cards is relatively simple. Except for the USB connector, all the components we use are SMD parts, so you can also draw directly on the PCB file.

PCB Design: Top Side

The top panel is used to record your personal information. Therefore, you need to customize a partial ground plane and import your personal information on layer 29 “tStop”, which is intended to control the solder mask on the top side. Text overlays on the top and “tStop” layers can give your PCB business cards a dazzling look.

Inductive Antenna on PCB Considerations

Radio waves cannot pass through the PCB board, so when designing the antenna, there must be no copper sheets above and below it. The correct way is as follows:

Correct Antenna Settings

When there is copper above the antenna, the ground plane of the PCB will block the reader, and energy cannot be transmitted between the NFC tag antennas, as shown in the following figure:

wrong antenna settings

PCB Layout

Place the required components on the underside of the PCB and place the LEDs on the bulb filaments. To make your pcb business card more beautiful, FS Technology recommends that you place other components below the line that draws the bulb. If you are making a PCB business card with NFC, you need to connect the wires to the NFC IC.

Generate Gerber files

Gerber files are the standard used by the PCB industry to describe PCB images and are required whether you are making your own PCBs or outsourcing the fabrication to a professional turnkey PCB assembly company. After completing the schematic diagram, you can click the “Convert” button in EasyEDA to convert the schematic diagram into a PCB design. If you are using Eagle, you can export Gerber files from Eagle using the built-in CAM processor.

Order PCB board

If you want a high quality pcb business card, you can send your order to FS Technology, we have the most advanced equipment, the best technical team, the cheapest price. As a PCB manufacturing expert in China, we recommend the following designs for your board:
  • Number of layers: 2 layers
  • PCB thickness: 1.0mm
  • Size: 50*80mm
  • Surface Treatment: HASL
  • Copper Weight: 1oz
Ordered printed circuit board

Component installation

In order for your printed circuit board business card to work properly (bare boards can’t work), you need to solder the SMD components to the PCB board, then use the programmer to write the code into the microcontroller, and finally do the pcb assembly inspection.

Packaging PCB business cards

You can use foam double-sided tape to seal the edge of your assembled PCB board, print a mask, put it on the foam double-sided tape, cut off the excess, and complete a creative pcb business card.

PCB Business Card with NFC

Introduction to NFC Technology

What is NFC?

NFC is a contactless identification and interconnection technology (similar to Bluetooth), its full name is Near Field Communication, which enables your mobile devices, consumer electronics to communicate within a range of < 10 cm. In recent years, popular mobile payment, identity authentication, transportation card recharge, etc. all rely on NFC.

How does NFC work?

The NFC working mode is divided into passive mode and active mode. This article only describes the active mode. Active mode means that when the signal sending device sends data to the target device, it must generate a radio frequency field, which can use the electromagnetic induction between the two loop antennas to charge the passive target (tag), as shown in the figure:
NFC schematic

NFC Chip Fabrication

Chip Requirements:

  • Small SMD package
  • Adequate storage capacity
  • Embedded Energy Harvesting Module

If you use a printed circuit board as a business card, the NFC chip is at its heart. The choice of the core can be varied, this article chooses NXP’s NTAG NT3H1101 IC. 

NTAG I2C is the latest passive TAG chip with I2C interface released by NXP, which is the agent of Dalian Dapinjia. It is widely used in household appliances, consumer electronics, wearable technology and home automation and other fields. It provides contactless and contact interfaces as shown:


Calculate Antenna Inductance

In order for the PCB business card to communicate and power, we need to add an antenna to the NFC tag. The antenna design of the NFC chip is relatively simple, as shown below:

Explanation of the icons in the picture above:

  • Voc: Magnetic field induced open circuit voltage
  • Ra: Equivalent resistance
  • La: Equivalent inductance
  • Rs: series equivalent resistance
  • Cs: Serial Equivalent Tuning Capacitance

When the transmitter senses a magnetic field, an open circuit voltage Voc appears at its terminals.

The sum of the series resistances Ra and Rs is the equivalent model of the circuit consisting of the NFC integrated circuit and its loop antenna, as shown in the following figure:

The NFC IC resistance Rs forms a resonance circuit RLC together with the antenna resistance Ra and the built-in capacitance Cs with the inductance La of the antenna.

The frequency formula of the resonant circuit RLC is shown in the figure:

 The formula for calculating the RLC of the resonant circuit

Resonant frequency formula noun explanation:

  • F: resonance frequency, unit: Hz
  • L: Equivalent inductance, unit: H
  • C: Equivalent capacitance, unit: F
L is an unknown parameter in this equation, and L needs to be calculated separately. The formula diagram is as follows:
Calculation of unknown parameters

Example: Assuming the frequency of NFC is 13.56 MHz and the tuning capacitance is 50 pF, bring it into the formula to get the inductance L as:

 Example diagram of inductance L

Rectangular Antenna Calculation

Only by obeying the geometric constraints, we can add a specific inductance antenna to the PCB board. Antennas with different geometries require different formulas to support. In order to facilitate the explanation, FS Technology uses a relatively simple rectangular antenna to design our PCB business card, as shown in the following figure:
Rectangular Antenna for PCB Business Cards

Explanation of the units in the diagram above:

  • A0 & B0: the overall size of the antenna
  • Aavg & Bavg: the average size of the antenna
  • T: track thickness
  • W: Track width
  • G: Gap between tracks
  • Nant: Number of turns
  • D: Equivalent diameter of the track
The formula for the equivalent inductance Lant is as follows:  
Equivalent inductance Lant
The interpretation of Lant’s formula is as follows:
Lant formula

Create Eagle Library

If you think designing the antenna is cumbersome, you can copy the rectangular open source antenna provided by NXP to design the antenna, and then change the position of the connector.

Design the Antenna

Soldering the NFC Chip

Hand soldering NFC ICs is the most difficult step in making NFC printed circuit board business cards. Using the flux as temporary glue, use a toothpick to place it on the footprint of the IC. When the IC is aligned with the footprint, secure the PCB assembly with cross locking tweezers. Then take a small amount of solder paste with a new toothpick and place it on the pins of the chip. Finally, use a hot air rework tool to melt the solder paste and solder the IC’s pins to the circuit tracks. If you use too much solder paste, you will create huge solder balls that can cause short circuits. At this point, it can be removed with the soldering iron and flux we prepared in advance, and finally the PCB business card is cleaned with Q-tip and isopropyl alcohol. The operations for the resistors and LEDs are almost the same, so I won’t repeat them too much.

Program the NFC Chip

NFC Tools for Android: Find the settings menu on your Android phone and open the NFC settings.
iOS NFC Tool: The NFC tool of the iPhone will start automatically.
Launch the NFC tool, find the “Write” button, click “Add Record”, select “URL” as the record, enter the URL you want the NFC tool to transmit, click the “OK” button, and then enter the NFC tag on the “Write” page, When the dynamic icon is displayed, hold the phone close to the business card, the LED of the business card should light up at this time, when the icon shows “Writing completed, your NFC PCB business card is complete.

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