Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H59/00—Electrostatic relays; Electro-adhesion relays
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H59/00—Electrostatic relays; Electro-adhesion relays
  • H01H59/0009—Electrostatic relays; Electro-adhesion relays making use of micromechanics
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H1/00—Contacts
  • H01H1/12—Contacts characterised by the manner in which co-operating contacts engage
  • H01H1/14—Contacts characterised by the manner in which co-operating contacts engage by abutting
  • H01H1/20—Bridging contacts
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H59/00—Electrostatic relays; Electro-adhesion relays
  • H01H59/0009—Electrostatic relays; Electro-adhesion relays making use of micromechanics
  • H01H2059/0054—Rocking contacts or actuating members

Definitions

• the present invention relates to an electrostatically operating microrelay which can be used as a switch and which can be produced using the methods of micromechanics.
• electrostatic microswitches are ideally suited and clearly superior to other semiconductor switches in terms of damping and noise behavior.
• a major advantage of such switches is that, apart from capacitive charging currents, the switching contacts can be controlled without power.
• Electrostatic switches with a short switching time in the range below 100 ⁇ s can only be realized with conventional methods if very large switching voltages can be accepted.
• a compromise must be made between the switching speed and the required switching voltage, since the stiffness of the resilient suspension of the switching element means that high switching voltages are required for high switching speeds.
• Battery voltages of up to 3 V are typically available especially for use in cell phones; Switching voltages of up to 12 V can be achieved using voltage multipliers.
• Micromechanical switches are usually formed with micromechanically producible bars, at the end of which the switch contacts are seated and which are bent by means of electrostatic attraction by means of electrical potentials on suitably attached electrodes in order to close the contacts. With switching times of 20 ⁇ s, electrical voltages of 30 V and more are typically required. These components are therefore unsuitable for use in mobile telephones or other low-power applications.
• CD 3 > QF, F- rt CQ
• the object of the present invention is to provide a component which can be used as a switch and which achieves high switching speeds with a low switching voltage.
• the microrelay according to the invention has a switching part which is rotatably suspended on a substrate and can be moved into two alternative switching states in the manner of a rocker by electrostatic attraction by means of suitably attached electrodes.
• the switching function is brought about in that electrodes which are fastened to the substrate above the rocker are short-circuited by metallizations on the upper side of the switching part.
• Figure 1 shows an example of a micro relay in cross section.
• Figure 2 shows the embodiment of Figure 1 in supervision.
• FIG. 3 shows a further example of a microrelay in cross section.
• Figure 4 shows the embodiment of Figure 3 in supervision.
• FIG. 1 the remaining portions of an auxiliary layer or sacrificial layer 11, a structural layer 2 and an electrically insulating layer 20 as well as contact electrodes 31, 32, which are firmly attached with respect to the substrate, are shown in cross section on a substrate 1 or a layer or layer structure present thereon.
• the switching part 9 in this exemplary embodiment has a cutout in the middle in which the anchoring 4 is arranged. Between the switching part 9 and the anchoring 4 there are aligned along the intended axis of rotation and acting as torsion springs
• 3 3 PJ PJ pj s; P 3 PJ 3 'F ⁇ ⁇ ⁇ ! ⁇ ⁇ T PJ
• the doping is omitted, so that the polysilicon here is electrically insulated or at least has only a low electrical conductivity. However, the doping can also be present in the entire switching part 9. Adequate electrical insulation of the contact electrodes 71, 72 can, if necessary, be brought about by electrically insulating layers 21, 22 (for example a nitride such as Si 3 N 4 ) between the contact electrodes 71, 72 and the switching part 9. , The course of the cross section shown in FIG. 1 and the hidden contours of the actuator electrodes 51, 52 attached to the substrate are shown in dashed lines.
• FIG. 2 clearly shows the structuring of the contact electrodes 31, 32 attached to the substrate, each of which has two portions 31a, 31b and 32a, 32b which are arranged at a short distance from one another. These portions are each arranged and aligned in such a way that they are short-circuited by a contact electrode 71, 72 on the upper side thereof when the rocking switching part is in a suitable position.
• two switching functions can be carried out simultaneously, with which one switch is closed and a second switch is opened at the same time.
• the double arrow shown in FIG. 1 refers to the correspondence between the axes of rotation given by the respective struts 8 in FIG. 1 or (shown in dotted lines) in FIG. 2.
• the contact electrodes 31, 32 can be applied to an electrically insulating layer 20 and connected by means of conductor tracks or provided with electrical connections via conductors in the structural layer 2.
• F P. F- ⁇ - 3 tr PJ 3 ⁇ ⁇ F Hi 0 «tr 3 rt - - F- LQ PJ cQ ⁇ CQ 3 ⁇ tr cn F rt 3 PJ 0 F F- PJ tr 0 F Hi ⁇ > Pi rt ⁇ F ⁇ ⁇ ⁇
• the movable part is therefore preferably made of a low-density material, preferably of polysilicon.
• Metallic coatings e.g.
• the microrelay according to the invention with contacts closing at the top (ie away from the substrate) enables a significant reduction in the moving mass (moment of inertia) and thus an increase in the switching speed with an unchanged low switching voltage, since the heavier part of the contact electrodes forming the switch is stationary with respect to the Substrate remains.
• the properties of the switch and the exercise of the switching force are in the invention

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• Micromachines (AREA)

Applications Claiming Priority (3)

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• 2000
  • 2000-02-02 DE DE10004393A patent/DE10004393C1/de not_active Expired - Fee Related
• 2001
  • 2001-02-01 WO PCT/DE2001/000389 patent/WO2001057901A1/de not_active Application Discontinuation
  • 2001-02-01 JP JP2001557065A patent/JP2003522379A/ja active Pending
  • 2001-02-01 KR KR1020027009941A patent/KR20020075904A/ko not_active Application Discontinuation
  • 2001-02-01 EP EP01913558A patent/EP1252640A1/de not_active Withdrawn
• 2002
  • 2002-08-02 US US10/211,058 patent/US6734770B2/en not_active Expired - Fee Related

Non-Patent Citations (1)

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