Tactile Switch SMD 4 Pin 3x3x1.5mm Micro Push Button

Specifications

• Switch Type: Tactile Push Button Switch

• Mounting Type: Surface Mount Device (SMD / SMT)

• Actuation Direction: Top-Actuated (Raised Button)

• Circuit / Contact Form: Single Pole Single Throw - Normally Open (SPST-NO)

• Dimensions (L × W × H): 3.0mm × 3.0mm × 1.5mm [Estimated]

• Contact Rating: 50mA @ 12V DC Max

• Contact Resistance: 100mΩ Max

• Insulation Resistance: 100MΩ Min @ 100V DC

• Dielectric Withstanding Voltage: 250V AC for 1 minute

• Operating Force: 180gf ± 50gf

• Travel / Stroke: 0.20mm ± 0.05mm

• Operating Life: 50,000 to 100,000 cycles

• Terminal Configuration: 4-Pin SMD / SMT Solder Leads

• Housing Material: High-Temperature Thermoplastic with Stainless Steel Cover

• Operating Temperature: -20°C to +70°C

• Compatible Platforms: Custom Microcontroller PCBs, Handheld Gadgets, Wearables, Key Fobs

Project Evolution

Unlock New Capabilities

• Past Projects (Prerequisites)
  If you've already experimented with standard 6x6mm through-hole tactile buttons on breadboards or larger 12x12mm push switches, you understand basic digital input sensing, pull-up resistors, and software switch debounce routines. Stepping up to this sub-miniature 3x3x1.5mm 4-pin SMD tactile switch is the natural progression toward converting bulky benchtop prototypes into sleek, professional, surface-mount PCB hardware.
• Feature Upgrade (What This Unlocks)
  This 3x3x1.5mm tactile switch unlocks ultra-compact top-actuated user input inside tight device enclosures. Featuring an overall profile height of just 1.5mm, a crisp 180gf actuation force, and 4 symmetrical SMT solder leads with an internal stainless steel dome cover, it enables reliable reset, power, and navigation button integration for wearable devices, compact remote key fobs, handheld test gear, and custom IoT sensor modules where space is at an absolute premium

Effort Level & Minimum Hardware

Effort Level: Intermediate

Minimum hardware to get started:

• Custom PCB with SMT Solder Pads or SMD Breakout Adapter Board — required because this switch utilizes miniature 3.0×3.0mm surface-mount solder leads that cannot plug directly into standard 2.54mm breadboards or perfboards.
  
• Fine-Tip Temperature-Controlled Soldering Station & Thin Solder Wire (0.3mm–0.5mm) — required to form reliable solder fillets on the 4 tiny leads without creating solder bridges or overheating the internal contact dome.
  
• Microcontroller Development Board (Arduino Uno, ESP32, or RP2040) — required to provide the digital logic pull-up voltage and read button state transitions in firmware.

Virtual Technician & Pinout Guide

⚠️ Safety Warnings:

• Soldering Thermal Limits: Do not exceed 260°C for more than 5 seconds during hand or reflow soldering; excessive thermal exposure will melt the internal thermoplastic housing and permanently ruin the tactile snap dome.
  
• Pin Pairing Verification: The 4 leads are internally connected in two pairs across the SPST-NO contact; always verify terminal continuity with a multimeter before soldering to avoid accidentally bridging your GPIO line straight to ground.
  
• Floating Input Prevention: Always configure the microcontroller GPIO pin with an internal pull-up resistor (or install an external 10kΩ pull-up resistor); leaving the input pin floating will cause random false triggers from environmental noise.

Package Includes: 

1× Tactile Switch SMD 4 Pin 3x3x1.5mm Micro Push Button

Frequently Asked Questions

1. Can this 3x3x1.5mm 4-pin SMD tactile switch be plugged directly into a solderless breadboard?
   No, it features sub-miniature surface-mount solder leads designed exclusively for custom printed circuit boards; it requires a custom PCB or an SMD breakout adapter board.

2. Is this momentary tactile switch compatible with 3.3V and 5V microcontrollers like Arduino and ESP32?
   Yes, as a passive mechanical dry-contact SPST switch, it interfaces seamlessly with 1.8V, 3.3V, and 5V logic inputs using microcontroller internal pull-up resistors.

3. Can this switch fit inside slim portable enclosures, key fobs, and wearable devices?
   Yes, with an ultra-compact 3×3mm footprint and a low 1.5mm profile, it is engineered specifically for space-constrained front bezels and slim device enclosures.

4. Is this 4-pin SMD switch footprint suitable for automated surface-mount pick-and-place assembly?
   Yes, its flat top button profile and standard tape-and-reel compatibility make it well-suited for automated vacuum pickup on SMT assembly lines.

5. What is the maximum electrical voltage and current rating for this tactile switch?
   The switch is rated for up to 12V DC at 50mA, making it ideal for low-voltage digital signaling, logic level sensing, and microcontroller GPIO inputs.

6. Can I use this micro tactile switch to switch power directly to motors, solenoids, or high-power LEDs?
   No, switching loads drawing greater than 50mA will pit or weld the internal metal dome contact; always use the switch to signal a MOSFET or transistor instead.

7. What is the minimum operating current required to maintain reliable electrical contact?
   The switch functions reliably with dry-circuit logic levels down to 10µA at 1V DC, ensuring dependable state changes in ultra-low-power battery-operated IoT nodes.

8. How are the 4 pins on this tactile switch internally connected?
   The 4 terminal leads are internally paired across the SPST-NO contact; opposite pins are linked together internally to provide convenient trace jumpering across the PCB.

9. How do I connect this 4-pin tactile switch to an Arduino GPIO pin? Connect one terminal pair to a digital GPIO pin configured with INPUT_PULLUP in software, and connect the opposite terminal pair directly to circuit ground (GND).

10. Does this tactile push button switch have polarity requirements during soldering?
    No, as a dry-contact momentary mechanical switch, it has no electrical polarity, though you must orient the internally paired leads correctly with your circuit traces.

11. Do I need any dedicated third-party library to read this switch in Arduino IDE?
    No, it can be read directly using digitalRead(), though utilizing software debounce routines or libraries like Bounce2 is recommended to filter contact chatter.

12. What debounce delay should I configure in firmware for this tactile switch?
    A standard software debounce delay between 10ms and 20ms in your microcontroller loop reliably eliminates mechanical contact chatter during pressing and releasing.

13. Can this tactile switch trigger hardware interrupts on ESP32 or STM32 boards?
    Yes, you can attach an interrupt configured for FALLING edge detection, provided you incorporate software debouncing to avoid triggering multiple ISR calls.

14. Why is my microcontroller registering erratic ghost button clicks when nobody touches the switch?
    This occurs if the GPIO pin is left floating without a defined reference; enable the microcontroller's internal pull-up resistor in code or wire an external 10kΩ pull-up resistor.

15. Why did the switch lose its tactile snap feedback after hand soldering? Excessive soldering heat above 260°C or iron contact lasting longer than 5 seconds deforms the internal thermoplastic housing and ruins the dome; always use quick iron touches under 3 seconds.