274

Ultra-low Profile Dome Array

B3DA

Dimensions

Unit: mm

Construction

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.

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.

Separator

(paper)

Sheet thickness (0.05)

Cover film

Contact dome (5 dia.)

Thickness: 0.06

B enlarged

A-A cross section

Two, 2.1 dia.

Four, R5

Contact dome

diameter

5 dia. (18 keys)

Operating

force (OF)

1.57

± 0.49 N

Plating

Unplated

B3DA-0000-A

Separator (paper)

Sheet thickness (0.05)

Cover film

Contact dome (4 dia.)

Thickness: 0.06

B enlarged

A-A cross section

Two, 2.1 dia.

Four, R5

Contact dome

diameter

4 dia. (18 keys)

Operating

force (OF)

1.57

± 0.49 N

Plating

Unplated

B3DA-0010-A

Cylindrical protrusion

Contact along

circle circumference

(circular contact)

Contact at center point

Conventional models

Contact dome resistant to

foreign matter (circular contact)

Separator

Cover film

Matrix adhesive

Stainless steel contact dome

(circular contact)

15

µm

Slits

Matrix (acrylic)

adhesive: 25

µm

Cover film