Wire clamp with piezoelectric actuator and method and apparatus for applying a preload force to the piezoelectric actuator

{
  "publication_number": "US9446524B2",
  "country": "US",
  "kind": "B2",
  "title": "Wire clamp with piezoelectric actuator and method and apparatus for applying a preload force to the piezoelectric actuator",
  "abstract": "A wire clamp includes a clamp body; a pair of arms coupled to the clamp body; and a piezoelectric actuator having a longitudinal axis extending between a first end and a second end, the actuator being coupled to the pair of arms at the first end and to the clamp body at the second end. The second end of the actuator is coupled to the clamp body by a preload mechanism for applying a preload force along the longitudinal axis, and the preload mechanism comprises at least one wedge having an inclined surface which is slidable over a mating inclined surface.",
  "claims": [
    "1. A wire clamp, comprising: a clamp body; a pair of arms coupled to the clamp body; and a piezoelectric actuator having a longitudinal axis extending between a first end and a second end, the actuator being coupled to the pair of arms at the first end and to the clamp body at the second end; wherein the second end of the actuator is coupled to the clamp body by a preload mechanism for applying a preload force along the longitudinal axis, and wherein the preload mechanism comprises at least one wedge having an inclined surface which is slidable over a mating inclined surface.",
    "2. A wire clamp according to claim 1, wherein the inclined surface has an angle of inclination which is less than a critical angle required for self-locking.",
    "3. A wire clamp according to claim 1, wherein the mating inclined surface is a mating inclined surface of another wedge.",
    "4. A wire clamp according to claim 3, wherein the other wedge is removable from the clamp body.",
    "5. A wire clamp according to claim 1, wherein the preload mechanism is disposed in a gap between the second end of the actuator and the clamp body.",
    "6. A wire clamp according to claim 1, wherein the at least one wedge is slidably insertable into a gap between the mating inclined surface and the piezoelectric actuator, or a gap between the clamp body and the mating inclined surface, to apply the preload force.",
    "7. A wire clamp according to claim 1, wherein the at least one wedge comprises at least one lug which is engageable to withdraw the at least one wedge from the wire clamp."
  ],
  "description_excerpt": "This invention relates to a wire clamp with a piezoelectric actuator, and to a method and an apparatus for applying a preload force to the piezoelectric actuator.\n\nIn semiconductor processing, an integrated circuit is connected to its packaging by wires in a process known as wire bonding. During wire bonding it is necessary to clamp the wire to be bonded in order to position it precisely at the desired location. One known device for clamping wires is shown in FIG. 1, and includes a pair of jaws 102, 104 which are driven by a piezoelectric actuator 110. Applying an electric field across the actuator 110 causes the jaws 102, 104 to open. When the electric field is switched off, the arms close such that the wire is clamped between clamping plates 106, 108.\n\nWhen using piezoelectric actuators it is necessary to apply a preload force to the piezoelectric element of the actuator before an electric field is applied. The magnitude of the preload force is important. If insufficient preload is applied, the piezoelectric element may break due to dynamic pull forces. If too much preload is applied, the actuator may not be able to successfully actuate.\n\nIn the wire clamp of FIG. 1, a preload force is applied by using a set screw 130 to apply a force to the piezo actuator 110, along its longitudinal axis (i.e, the axis running along the centre of the piezo actuator 110 and perpendicular to its ends 112, 114) via a preload block 120. The set screw 130 and preload block 120 push the piezo actuator 110 against the wire clamp main body 105.",
  "cpc": [
    "H10W 72/0711",
    "B25J 15/0028",
    "B25J 15/0033",
    "B25J 15/0042",
    "E02D 3/054",
    "H01L 2224/45099",
    "H01L 2224/78",
    "H01L 24/74",
    "H01L 24/78",
    "H01L 24/85",
    "H01L 2924/00014",
    "H10N 30/00",
    "H10N 30/01",
    "H10P 72/00",
    "H10W 72/011",
    "H10W 72/075",
    "H10W 72/50",
    "H10W 72/551",
    "Y10T 29/49998",
    "Y10T 29/53222",
    "Y10T 29/53226",
    "Y10T 29/5323",
    "Y10T 29/53257",
    "Y10T 29/53283"
  ],
  "ipc": [
    "B25J 15/00",
    "B25J 15/02",
    "E02D 3/054",
    "H01L 23/00"
  ],
  "assignees": [
    "ASM Technology Singapore Pte Ltd"
  ],
  "inventors": [
    "Yue Zhang",
    "Chong Hao Chen",
    "Zheng Yu LIN"
  ],
  "filing_date": "2013-11-14",
  "publication_date": "2016-09-20",
  "grant_date": "2016-09-20",
  "priority_date": "2013-11-14",
  "application_number": "US-201314079840-A",
  "family_id": "53042402",
  "cited_by_count": 7,
  "citations": [
    "JPH05259213A",
    "US20050279805A1",
    "US20100300752A1"
  ]
}