B3D-4112 Omron, B3D-4112 Datasheet - Page 2

• Manufacturer Part Number: B3D-4112
• Description: 4MM DOME
• Manufacturer: Omron
• Series: B3Dr
• Type: Tactile Switchesr

Specifications of B3D-4112

• Circuit: SPST-NO
• Switch Function: Off-Mom
• Contact Rating @ Voltage: 0.01A @ 12VDC
• Actuator Type: Snap Dome
• Mounting Type: Surface Mount
• Orientation: Vertical
• Illumination: Non-Illuminated
• Operating Force: 167gf
• Contact Form: SPST - NO
• Termination Style: Through Hole
• Operating Temperature Range: - 40 C to + 80 C
• Contact Voltage Dc Nom: 12V
• Contact Current Max: 10mA
• Actuation Type: Top
• Switch Terminals: PCB / Push-on
• Operating Force Min: 1.18N
• Operating Force Max: 2.16N
• Rohs Compliant: Yes
• Actuator / Cap Color: White
• Actuator Style: Dome
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: B3D4112; SW978

Structure
■ Matrix Adhesive
The surface structure of this adhesive has grid-shaped slits, as
shown in the following cross-sectional diagram. These slits provide
both ventilation and dust-proofing, which is required for contact dome
operation.
Recommended Contact Form
270
4 mm Diameter Contact Dome (B3D-4112)
Polyurethane
rubber film (with adhesive)
Single-side PCB
Multilayer PCB
15 µm
PET film (white)
(with matrix adhesive)
Ultra-low Profile Dome Key
2.8 dia.
2.8 dia.
1.8 dia.
1.8 dia.
5.2 dia.
5.2 dia.
Slits
Gold-plated nickel
Gold-plated nickel
Resist (30 to 50 µm)
Cover film
Matrix (acrylic)
adhesive: 25 µm
0.4
B3D
1.2
Stainless steel
contact dome
(circular contact)
2.0
■ Circular Contact
When contact dome keys are attached to the PCB, any PCB dust or
foreign particles will tend to collect in the center of the key when it is
pressed. Therefore, poor contact occurs easily in keys that provide
contact at the center point only.
The circular contact construction provides contact along the circumference of
a circle, thus preventing poor contact by avoiding the center point.
5 mm Diameter Contact Dome (B3D-5112)
Single-side PCB
Multilayer PCB
Conventional models
Contact at center point
3.8 dia.
3.8 dia.
2.3 dia.
2.3 dia.
6.2 dia.
6.2 dia.
foreign matter (circular contact)
Contact dome resistant to
Gold-plated nickel
Gold-plated nickel
Resist (30 to 50 µm)
Cylindrical protrusion
Contact along
circle circumference
(circular contact)
0.4
1.2
2.0