B3D-5112 Ultra-low Profile Dome Key B3D Single-key Type Added to Series of B3DA Ultra-low Profile Dome Arrays No soldering required. Attach directly to PCB to make an ultra-low profile tactile switch. Construc- tion provides strong resistance to static electricity by having no soldered terminals. Matrix adhesive used to create highly dust-proof construction with good ventilation. Lower profile, lighter weight, and crisp clicking action. OMRONs unique circular contact action ensures a high level of resistance to foreign matter. RoHS Compliant Application Examples Use Dome Keys for the operating parts on various electronic devices that require low-profile controls, as follows: Operating switches with few mounted parts above PCBs. (Example: Camera operating buttons) Small orders, where initial investment in Dome Arrays is not fea- sible. (Example: Trial applications, commercial equipment, etc.) Applications requiring a single key only. (Example: Reset buttons) Specifications List of Models/Ratings/Characteristics Item Model B3D-4112 B3D-5112 Diameter of contact dome 4-mm dia. 5-mm dia. Operating force (OF) 1.670.49 N 17050 gf Releasing force (RF) 0.2 N 20 gf min. Pretravel (PT) 0.20.1 mm Thickness 0.30.1 mm Durability 500,000 operations min. 1,000,000 operations min. Switching capacity 10 mA, 12 VDC (resistive load) (recommended minimum load: 1 mA, 3 VDC (resistive load)) Ambient operating temperature 40 to 80C (60%RH) (with no icing or condensation) Ambient storage humidity 10% to 90% (at 40C max.) Contact dome Stainless steel Plating Silver Note: The Dome Keys are sold in units of 500 (20 sheets, with 25 Dome Keys per sheet). Order in multiples of 500 Dome Keys. 1 B3D-4112B3D B3D Model Structure Circular Contact When contact dome keys are attached to the PCB, any PCB dust PET film (white) or foreign particles will tend to collect in the center of the key (with matrix adhesive) when it is pressed. Therefore, poor contact occurs easily in keys that provide contact at the center point only. Stainless steel contact dome The circular contact construction provides contact along the cir- (circular contact) Polyurethane cumference of a circle, thus preventing poor contact by avoiding rubber film (with adhesive) the center point. Contact dome resistant to Conventional models foreign matter (circular contact) Matrix Adhesive The surface structure of this adhesive has grid-shaped slits, as shown in the following cross-sectional diagram. These slits pro- vide both ventilation and dust-proofing, which is required for con- tact dome operation. Cylindrical protrusion Cover film Matrix (acrylic) 15 m adhesive: 25 m Slits Contact along Contact at center point circle circumference (circular contact) Recommended Contact Form 4-mm Diameter Contact Dome (B3D-4112) 5-mm Diameter Contact Dome (B3D-5112) 6.2 dia. 5.2 dia. Gold-plated nickel Gold-plated nickel 2.3 dia. 1.8 dia. 0.4 0.4 1.2 2.0 1.2 2.0 Single-side PCB Single-side PCB 2.8 dia. Resist (30 to 50 m) Resist (30 to 50 m) 3.8 dia. 6.2 dia. 5.2 dia. Gold-plated nickel Gold-plated nickel 2.3 dia. 1.8 dia. Multilayer PCB Multilayer PCB 2.8 dia. 3.8 dia. Recommended Operating Part Form 4-mm Diameter Contact Dome (B3D-4112) 5-mm Diameter Contact Dome (B3D-5112) Resin Resin 1 dia. 1.5 dia. Entire Entire circumference: R 0.2 circumference: R 0.2 Note: All units are in millimeters unless otherwise indicated. 2