Use this checklist before approving a tact switch, micro switch, slide switch, DIP switch or rotary encoder for a new OEM design or second-source project.

The objective is not to find a part that looks similar or works once on the bench. The objective is to confirm that the electrical, mechanical, environmental and production requirements are defined well enough for repeatable qualification and volume supply.

Download the PDF Checklist

Prefer a printable version for engineering review, supplier meetings or internal qualification? Download the Swiclick Switch Selection & Validation Checklist as a PDF.

Download the Switch Selection & Validation Checklist PDF

The 8 Areas to Validate Before Production Approval

Confirm the switch function, electrical load, mechanical interface, contact performance, environment, life requirement, assembly process and supplier production controls before releasing the part into the BOM.

1. Define the Switching Function

Start by defining what the component actually has to do in the circuit or mechanism.

  • Momentary or maintained operation
  • SPST, SPDT, DPDT or other contact configuration
  • Normally open, normally closed or changeover function
  • Position sensing, user input, addressing, mode selection or signal routing
  • Shorting or non-shorting behavior where relevant
  • Number of positions for DIP, slide or rotary switches

Do not select a switch family from appearance alone. Circuit function should be defined before package style.

2. Define the Real Electrical Load

  • Voltage
  • Current
  • AC or DC
  • Resistive, inductive, motor, capacitive or signal-level load
  • Minimum applicable load where relevant
  • Inrush or transient conditions
  • Required electrical life under the actual load

A maximum current rating alone is not enough. Two applications drawing the same steady-state current can impose very different stress on the contacts.

For low-level circuits, see Minimum Applicable Load and Dry Circuit Switching .

3. Validate Mechanical Fit and Actuation

  • Body dimensions
  • Mounting-hole pattern or PCB footprint
  • Terminal layout and orientation
  • Actuator type and geometry
  • Actuator height
  • Operating force
  • Pretravel
  • Operating point
  • Overtravel
  • Total travel
  • Return force where relevant
  • Available clearance in the finished enclosure

For micro switches, the mechanism must operate the actuator within the intended travel range. For tact switches, the keycap or enclosure can significantly change the force felt by the user.

See Tactile Switch Operating Force and Travel .

4. Confirm Contact Performance

  • Initial contact resistance
  • End-of-life contact resistance requirement if the circuit is sensitive
  • Contact material or plating where relevant
  • Minimum applicable load
  • Bounce requirement for digital input circuits
  • Required resistance measurement method

For low-resistance measurements, the test method matters. A specification without the measurement conditions can be difficult to compare across suppliers.

See Switch Contact Resistance Measurement and Failure Guide and Contact Bounce and Debounce in Mechanical Switches .

5. Define Environmental Requirements

  • Operating temperature
  • Storage temperature
  • Humidity
  • Dust exposure
  • Moisture or temporary water exposure
  • Required IP rating where applicable
  • Vibration and shock
  • Cleaning chemicals or PCB wash process
  • Outdoor or corrosive environment

Do not treat IP67, process sealing and PCB washability as interchangeable specifications. Confirm each requirement separately against the exact model.

See IP67 vs IP68 for Switch Selection .

6. Match the Assembly Process

  • SMD or through-hole mounting
  • Reflow soldering
  • Wave soldering
  • Hand soldering
  • Maximum soldering temperature and exposure time
  • PCB wash or cleaning process
  • Tape-and-reel, tray or bulk packaging
  • Pick-and-place requirements

A switch that works electrically can still fail in production if its housing, terminals or sealing are not compatible with the assembly process.

See Reflow and Wave Soldering Requirements for PCB Switches .

7. Define Life and Validation Conditions

  • Expected number of operating cycles
  • Mechanical life requirement
  • Electrical life requirement
  • Load used during life testing
  • Operating frequency
  • Temperature during validation
  • Mechanical linkage or actuator conditions
  • Acceptance limits after testing

Cycle-life numbers should only be compared when the electrical load and test conditions are comparable.

8. Qualify the Supplier and Production Process

  • Quality-management system
  • Model-specific certifications where required
  • Incoming, in-process and outgoing inspection controls
  • Lot traceability
  • Critical dimension and force control
  • Sample availability
  • MOQ and production lead time
  • Packaging requirements
  • Change-notification process
  • Quality-response process

Do not qualify a supplier from one good sample alone. The real question is whether the approved specification can be maintained across normal production lots.

New Design vs Second-Source Qualification

New Design

Start from the function, PCB or mechanical envelope, electrical load and operating environment. Select the switch family first, then narrow down the exact model.

Second Source

Start from the incumbent manufacturer, complete part number, suffix, drawing and datasheet. Compare both parts parameter by parameter before sample testing.

For an existing switch model, use the Switch Model Finder or review Switch Second Source Solutions .

RFQ Information Checklist

A useful switch RFQ should provide enough information for the supplier to reject unsuitable models rather than simply quote the closest-looking part.

RFQ Item What to Provide
Existing Part Manufacturer, complete model number and suffix if this is a replacement project.
Application What the switch does in the product or mechanism.
Circuit Contact form, voltage, current, AC/DC and load type.
Mechanical Drawing, PCB footprint, actuator, force, travel and available space.
Environment Temperature, humidity, IP/sealing, vibration and other relevant conditions.
Life Expected cycle count and load conditions.
Assembly SMD/THT, soldering process, cleaning and packaging requirements.
Compliance Required standards, certifications and destination market.
Volume Sample quantity, annual demand and expected production timing.

Do Not Approve a Switch from One Matching Number

A candidate can match the current rating and body size and still fail qualification because of a different actuator position, force, travel, contact material, minimum load, terminal orientation, soldering limit or certification scope.

Treat every cross-reference as a qualification candidate until the parameters that matter to the actual application have been verified.

Certification Is Model-Specific

Quality-system certifications such as ISO 9001 and IATF 16949 describe the manufacturing system. Product certifications such as UL, TÜV or ENEC apply to defined products and configurations.

Do not assume an approval applies to an entire switch family because one model carries the mark.

See Switch Certification Matching for UL, TÜV and ENEC .

Need Help Reviewing a Switch Specification?

Send the existing part number, datasheet or drawing, electrical load, mechanical requirements, operating environment and annual volume. Swiclick can review suitable candidates and identify the parameters that still require qualification.

Send Your Requirement Submit an Existing Part Number