Compact Tactile Push Switch For Bluetooth Control Modules

A low‑profile, surface‑mount tactile push switch engineered for Bluetooth control modules and compact IoT devices. Optimized for pairing, reset, and mode selection keys, it delivers a crisp, quiet click, low contact bounce, and long life in tight RF layouts. Optional top seal and ground pin enhance ESD robustness while maintaining minimal footprint and height for dense modules and wearables.

Key Features

• Compact, low‑profile SMD form factors for tight RF designs
• Precise, quiet tactile feedback with low bounce for clean GPIO reads
• Long operating life up to 1,000,000 cycles (force‑dependent)
• Gold‑plated contacts for low resistance and low‑level logic switching
• Optional IP67 top seal for dust/moisture protection
• ESD‑robust design; optional ground terminal for improved discharge path
• RF‑friendly: non‑magnetic materials and light‑pipe compatibility
• Multiple actuation forces (light/medium/firm) to suit user feel and accidental‑press immunity
• RoHS and REACH compliant; halogen‑free materials
• Tape‑and‑reel packaging for automated pick‑and‑place

Typical Applications

• Bluetooth pairing/wake buttons on control modules and evaluation boards
• Mode, reset, and factory‑restore keys on BLE gateways, beacons, and tags
• User input keys for wearables, hearables, and remote controllers
• Headphone/earbud cases, smart trackers, and handheld BLE remotes
• OTA update trigger and test/diagnostic buttons on production fixtures

Electrical Specifications

• Function: Momentary, normally open (SPST)
• Rating (resistive load): 12 VDC max, 50 mA max
• Low‑level capability: 10 µA at 1–3.3 V logic compatible
• Contact resistance: ≤100 mΩ initial (≤150 mΩ after life)
• Insulation resistance: ≥100 MΩ at 100 VDC
• Dielectric strength: 250 VAC for 1 minute
• Contact bounce: ≤5 ms typical
• ESR/EMI: Non‑magnetic; designed for minimal RF detuning when placed per guidelines

Mechanical Specifications

• Actuation force options (typical): 100 gf (light), 160 gf (standard), 260 gf (firm)
• Total travel: 0.2–0.5 mm (variant‑dependent)
• Operating life: up to 500k cycles (standard); up to 1M cycles (light‑force, sealed)
• Tactile profile: Crisp dome response with quiet acoustic signature
• Mounting: Surface mount (SMT), 2‑pad or 4‑pad options; optional ground pad
• Actuator: Low‑wobble, flat or raised profile compatible with thin key caps

Environmental & Reliability

• Operating temperature: −40 to +85°C (−40 to +105°C high‑temp option)
• Storage temperature: −40 to +85°C
• Humidity: 95% RH, 40°C (96 h), no electrical/mechanical damage
• Ingress protection: IP67 top‑sealed option (splash, sweat, and dust)
• ESD immunity (with proper PCB grounding): IEC 61000‑4‑2 ±8 kV contact, ±15 kV air
• Flammability: UL94 V‑0 housing material
• Chemical resistance: Sweat, skin oils, and common household cleaners (brief exposure)

Footprints, Heights, and Dimensions

• Ultra‑compact: 3.5 × 2.9 mm, height 1.5–1.9 mm
• Compact: 4.2 × 3.3 mm, height 1.7–2.5 mm
• Standard low profile: 4.5 × 4.5 mm, height 1.8–2.5 mm
• Actuator diameter: 2.0–3.0 mm contact area (variant‑dependent)
• Light‑pipe friendly cap interface (optional snap‑fit caps available)

Materials

• Dome: Stainless steel with gold plating for stable low‑level switching
• Terminals: Copper alloy, nickel underplate, gold flash
• Housing: LCP or high‑temperature thermoplastic, UL94 V‑0
• Sealing film (sealed variants): PET/Polyimide top membrane

Mounting & Soldering

• Process: Pb‑free reflow per JEDEC J‑STD‑020
• Peak temperature: 245–260°C, ≤30 s above 245°C
• Moisture sensitivity level: MSL 1 (unsealed); MSL 2A (sealed) – check label
• Coplanarity: ≤0.1 mm
• Cleaning: Aqueous cleaning compatible; avoid solvents on sealed membrane

RF/ESD Design Guidelines for Bluetooth Modules

• Maintain antenna keep‑out: place switches ≥10–15 mm from chip/PCB antenna and its feed
• Use non‑metallic key caps/light pipes near the antenna region
• Route switch traces on inner layers; surround with ground where possible
• Add nearby chassis/ground pad and optional ESD diode to chassis to shunt surges
• Debounce in firmware (5–20 ms) to suppress residual bounce
• For wake/pair keys, use internal pull‑ups and long‑press logic to prevent accidental activation

Options & Customization

• Actuation forces: ~100/160/260 gf
• Heights: 1.5/1.7/2.0/2.5 mm body heights
• Sealing: Vented (standard) or IP67 top‑sealed
• Termination: 2‑pin standard; 4‑pin with ground/shield pad
• Feel tuning: Dome geometry for softer or crisper click
• Caps: Low‑profile snap‑on caps (black, gray, translucent) for improved ergonomics
• Color coding: Housing tint or laser marking for assembly ID

Ordering Information

• Series: CTP‑BT (Compact Tactile for Bluetooth)
• Size code: 35 (3.5 × 2.9 mm), 42 (4.2 × 3.3 mm), 45 (4.5 × 4.5 mm)
• Force: L (100 gf), M (160 gf), F (260 gf)
• Height: 15/17/20/25 (1.5/1.7/2.0/2.5 mm)
• Seal: S (sealed IP67), N (non‑sealed)
• Pins: 2 (standard), 4 (with ground)
  Example: CTP‑BT‑35‑M‑17‑S‑4 = 3.5 × 2.9 mm, 160 gf, 1.7 mm height, sealed, 4‑pad with ground

Packaging

• Tape‑and‑reel per EIA‑481
• Tape width: 8 mm (ultra‑compact), 12 mm (larger variants)
• Reel quantities: 2,000–5,000 pcs per reel (size‑dependent)
• Marking: Lot/date code on reel; laser/emboss code on housing where applicable

Quality & Compliance

• RoHS compliant (Pb, Hg, Cd, Cr6+, PBB, PBDE free)
• REACH SVHC compliant
• Halogen‑free (<900 ppm Cl, <900 ppm Br, total <1500 ppm)
• 100% electrical test for actuation and contact continuity
• AQL sampling per ISO 2859 for cosmetic/mechanical criteria

Typical Use Cases

• BLE module “PAIR/CONNECT” button with long‑press detection
• Reset/bootloader access on compact RF designs
• Low‑noise user keys on wearables and handheld BLE controllers

Notes

• Select actuation force and travel based on enclosure stiffness and desired haptics
• For sealed variants, avoid over‑travel beyond rated stroke
• Keep switch and cap clear of the antenna keep‑out to preserve RF performance