Automated particle removal system having angular adjustability

{
  "publication_number": "US11400495B2",
  "country": "US",
  "kind": "B2",
  "title": "Automated particle removal system having angular adjustability",
  "abstract": "A foreign particle removal system for removing a foreign particle from a surface of an object has a tool gripper which grips a particle removal tool. A tip of the particle removal tool has a sticky tip portion. The sticky tip portion has an apex region at a remote end of the sticky tip portion and a flank region adjoining the apex region. The tool gripper holds the particle removal tool at an oblique angle with respect to the surface so that the flank region of the sticky tip portion faces towards the surface. The tilted particle removal tool is conveyed with the tool gripper to contact the foreign particle on the surface with the flank region of the sticky tip portion and a force is exerted onto the surface to attract the foreign particle onto the flank region. The particle removal tool may then be lifted away from the surface together with the foreign particle.",
  "claims": [
    "1. An automated method for removing a foreign particle from a surface of an object, the method comprising the steps of: gripping a particle removal tool with a tool gripper which is operatively connected to an alignment actuator, a tip of the particle removal tool including a sticky tip portion, the sticky tip portion further having an apex region at a remote end of the sticky tip portion and a flank region adjoining the apex region; driving the tool gripper with the alignment actuator to tilt the particle removal tool at an oblique angle with respect to the surface so that the flank region of the particle removal tool faces towards the surface; conveying the tilted particle removal tool with the tool gripper to contact the foreign particle on the surface with the flank region of the particle removal tool and exerting a force onto the surface to attract the foreign particle onto the flank region; and lifting the particle removal tool away from the surface with the tool gripper to remove the foreign particle from the surface.",
    "2. The method of claim 1, wherein the particle removal tool has a longitudinal axis, and the method further comprises the step of rotating the tilted particle removal tool with the tool gripper about the longitudinal axis so as to position an unused portion of the flank region of the particle removal tool to face the surface, and lifting another foreign particle away from the surface.",
    "3. The method of claim 1, further comprising the step of driving the particle removal tool with an XY driving mechanism coupled to the tool gripper to scrub the surface with the particle removal tool for attracting the foreign particle onto the flank region.",
    "4. The method of claim 1, wherein the particle removal tool is gripped by the tool gripper when the particle removal tool is stored at a cleaning tool station containing a supply of multiple particle removal tools.",
    "5. The method of claim 1, further comprising the step of determining a position of the apex region of the tilted particle removal tool with an optical device prior to conveying the particle removal tool to contact the foreign particle.",
    "6. The method of claim 1, wherein the sticky tip portion of the particle removal tool comprises a gel-like substance attached to one end of a stick.",
    "7. The method of claim 1, further comprising the step of applying a force in predetermined increments until a threshold force is exerted on the foreign particle by the particle removal tool for attracting the foreign particle onto the flank region."
  ],
  "description_excerpt": "The invention relates to the removal of foreign particles, and in particular, small debris from fragile surfaces.\n\nCMOS (complementary metal oxide semiconductor) sensors are used to optically capture images in digital cameras. In the semiconductor industry, foreign particles (particularly debris) on CMOS sensor surfaces during the manufacture of CMOS sensors are strictly controlled and should be eliminated in the manufactured product. Although cleaning using chemicals or water is typically conducted to wash foreign particles away from the CMOS sensor surface, physical inspection should also be performed to inspect the sensor surface thereafter for the presence of foreign particles, as these might adversely affect the quality of images captured by the CMOS sensor.\n\nSuch inspection of the CMOS sensor surface for foreign particles may be conducted manually by human operators or automatically by Automated Optical Inspection (“AOI”) devices. If foreign particles are found, a human operator will typically use a suitable tool to manually remove such particles individually.\n\nOne concern with the aforesaid approach is that the CMOS sensor may be damaged during the removal of particles when using a tool to pick up these particles, as such tools will typically make contact with the CMOS sensor surface. Meanwhile, manual removal of particles is also a slow and laborious process.\n\nA prior art cleaning apparatus utilizes a vertically arranged particle removal tool which is adapted to exert a force on the particle removal tool to lift the foreign particles from the surface of an object.",
  "cpc": [
    "B08B 7/0028",
    "B08B 1/001",
    "B08B 13/00",
    "B65G 47/90",
    "G01N 21/94",
    "H01L 21/02041",
    "H01L 21/02057",
    "H10P 70/00",
    "H10P 70/20",
    "H10P 72/0406"
  ],
  "ipc": [
    "B08B 1/00",
    "B08B 7/00",
    "B65G 47/90",
    "G01N 21/94",
    "H01L 21/02"
  ],
  "assignees": [
    "ASM Technology Singapore Pte Ltd"
  ],
  "inventors": [
    "Keng Yew Song",
    "Chin Tiong ONG",
    "Soo Kin (Kenny) Tan",
    "Qing Le TAN",
    "Gang Shu"
  ],
  "filing_date": "2020-09-09",
  "publication_date": "2022-08-02",
  "grant_date": "2022-08-02",
  "priority_date": "2020-09-09",
  "application_number": "US-202017015133-A",
  "family_id": "80469501",
  "cited_by_count": 1,
  "citations": [
    "US6175984B1",
    "US20020101584A1",
    "US20060054189A1",
    "US20180267252A1",
    "US10507569B1",
    "US20210227952A1"
  ]
}