Ultra-low Profile Dome Array
B3DA
Ultra-low Profile Dome Array with Dust-Proof
Construction and Crisp Clicking Action
■ No soldering required. Attach directly to PCB to
make an ultra-low profile tactile switch.
■ Matrix adhesive used to create highly dust-proof
construction with good ventilation. Omron’s
unique circular contact action ensures a high level
of resistance to foreign matter.
■ Lower profile, lighter weight, and crisp clicking
action.
■ Customization of Dome Array available upon
request (i.e., silver plating, number of contacts,
shpae, etc.)
RoHS Compliant
Specifications
■
List of Models/Ratings/Characteristics
Item
Model
4-mm dia. versions
Diameter
4 mm dia.
Operating force (OF)
1.57±0.49 N {160±50 gf}
Releasing force (RF)
0.2 N {20 gf} min.
Pretravel (PT)
0.2±0.1 mm
Height
0.25±0.1 mm
Durability
500,000 operations min.
Switching capacity
10 mA, 12 VDC (resistive)
Recommended min. load: 1 mA, 3 VDC (resistive)
5-mm dia. versions
5 mm dia.
1,000,000 operations min.
Ambient operating temperature −40 to 80°C (at 60% RH max.) with no icing or condensation.
Ambient storage humidity
10% to 90% (at 40°C max.)
Material
Stainless steel
Plating
Unplated. silver
Note:
Contact dome specifications not shown in this table are also available. Consult Omron for customization requirements.
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B3DA
■
B3DA
Model Structure
Stainless steel contact dome
(circular contact)
Cover film
Matrix adhesive
Separator
Matrix Adhesive
Circular Contact
When Dome Arrays 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 Dome Arrays
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.
Conventional models
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.
Contact dome resistant to
foreign matter (circular contact)
Cover film
15 μm
Matrix (acrylic)
adhesive: 25 μm
Cylindrical protrusion
Slits
Contact at center point
Dimensions
Note:
All units are in millimeters, unless otherwise in diated.
■ Recommended Contact
4-mm Diameter Contact Dome
5.2 dia.
1.8 dia.
2.8 dia.
Form
5-mm Diameter Contact Dome
6.2 dia.
Gold-plated nickel
2.3 dia.
Resist (30 to 50 μm)
3.8 dia.
5.2 dia.
1.8 dia.
Gold-plated nickel
Resist (30 to 50 μm)
6.2 dia.
2.3 dia.
2.8 dia.
3.8 dia.
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Gold-plated nickel
Gold-plated nickel
Contact along
circle circumference
(circular contact)
B3DA
B3DA
Sample for Engineering Reference
B3DA-0000
Separator
(paper)
Sheet thickness (0.05)
Contact dome 5 dia.
diameter
(18 keys)
Cover film
Operating
force (OF)
1.57 ±0.49 N
Plating
Unplated
Two, 2.1 dia.
Contact dome (5 dia.)
Thickness: 0.06
Four, R5
A-A cross section
B enlarged
B3DA-0010
Separator (paper)
Sheet thickness (0.05)
Contact dome 4 dia.
diameter
(18 keys)
Cover film
Operating
force (OF)
1.57 ±0.49 N
Plating
Unplated
Two, 2.1 dia.
Contact dome (4 dia.)
Thickness: 0.06
Four, R5
B enlarged
A-A cross section
Precautions
■
Attaching to the PCB
■
Washing
Remove the Dome Array from the sheet using tweezers or a vacuum pick-up tool, and attach it above the contact on the PCB surface, which has been wiped clean in advance.
Do not wash the Dome Array. The Dome Array is not water-resistant and must not be exposed to water or other liquids.
Do not reuse a Dome Array that has been detached from the
PCB. Attach a new Dome Array to the PCB.
■
Do not touch the Dome Array with bare hands, or with unclean
gloves. Doing so may damage the Dome Array, which is the part
that comes in contact with the PCB.
■
Common Precautions
Be sure to read the safety precautions common to all Tactile
Switches on pages for correct use.
Reflow Soldering
The Dome Array cannot withstand heat from reflow soldering.
Always perform reflow soldering before attaching the Dome Array
to the PCB.
ALL DIMENSIONS SHOWN ARE IN MILLIMETERS.
To convert millimeters into inches, multiply by 0.03937. To convert grams into ounces, multiply by 0.03527.
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