Ask: What does it mean to over-travel a metal dome?
Answer: Most of our metal domes are designed to be depressed to flat and no further. However, in some applications more travel is required. Our Circle-Series metal domes are designed with an additional .005" travel past the flat plane. This means that the dome will exhibit its designed characteristics only when over-traveled. Conversely, the dome will not exhibit its designed tactile response when pushed to flat. The Circle-Series metal domes will accommodate this additional travel without damaging the metal dome.
Ask:Do I need to vent the domes through my printed circuit board?
Answer:While venting is not absolutely necessary for every application, it is desirable in almost all applications. When the dome is depressed, air is trapped underneath it. To avoid compressing the air under the dome when actuated, it is recommended that a vent channel be present. The venting of the dome can be achieved a number of different ways. Some Examples: a.) vent channel can go from dome to dome via a spacer layer b.) Dome arrays can be top vented through the polyester material c.) Vent channel can go through the board. Not properly venting the dome will result in significant loss of tactile response.
Ask: Is there a recommended actuator for depressing the domes?
Answer:While there are any number of different sizes and shapes of actuators, we test the actuation force of our domes with a .050 diameter, flat-bottom plunger. See Test Criteria for more information on testing the domes.
Ask:How do I apply the metal domes to my p.c.b., membrane, or flex circuit?
Answer:Our metal domes are applied by means of pressure-sensitive adhesive tape. Several standard material options are available, as well as custom materials.
Ask:Can the domes be soldered to a circuit board?
Answer:Not recommended. When the domes are pushed, the feet actually move outward slightly. When soldered to a circuit board, the feet of the domes are restricted from their natural movement. This restriction can negatively affect the tactile response of the domes, and in some cases, cause irreparable damage to the domes.