Apparatus for inspecting the appearance of semiconductor devices

• US 4,907,701 A
• Filed: 08/19/1988
• Issued: 03/13/1990
• Est. Priority Date: 01/13/1988
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Itoh, Sekio, Kobayashi, Kunio
• Primary Examiner(s): Hajec, Donald T.
• Application Number:
  US07/233,742
• Time in Patent Office: 571 Days
• Field of Search: 209/576, 209/587, 209/577, 209/939, 209/573, 209/598, 209/914, 209/919, 209/905, 198/470.1, 198/803.5, 198/974, 198/740, 198/468.6, 198/468.1, 382/1, 382/8, 414/225, 414/416
• US Class Current: 209/576
• CPC Class Codes: B07C 5/344 according to electric or electromagnetic properties sorting according to size measured electrically or electronically B07C5/08; material testing by magnetic means G01N24/00, G01N27/00, by electrical means G01N27/00; electrical measuring devices in general G01R; coin testing G07D5/00
• CPC Class Codes: G01R 31/2656 using non-ionising electromagnetic radiation, e.g. optical radiation
• CPC Class Codes: Y10S 209/905 Feeder conveyor holding item by suction
• CPC Class Codes: Y10S 209/939 Video scanning

Abstract

An apparatus for inspecting the appearance of a semiconductor device has an imaging device which forms an image of the outside of a semiconductor device. An image analyzer analyzes the image and determines whether the semiconductor device is good or bad. A semiconductor device to be inspected is removed from a first conveyor on the periphery of a turntable by a vacuum chuck which is mounted on the turntable, and the semiconductor device is transported to in front of the imaging device by a turntable. If the semiconductor device is determined to be good, the turntable transports the semiconductor device to a second conveyor on the periphery of the turntable, and the vacuum chuck deposits the semiconductor device on the second conveyor. If the semiconductor device is determined to be bad, the turntable transports the semiconductor device to a discard receiving mechanism on the periphery of the turntable, and the vacuum chuck deposits the semiconductor device on the discard receiving mechanism.

Claims

1. An apparatus for inspecting packaged semiconductor devices comprising:

a turntable including at least four vacuum chucks for holding and releasing semiconductor devices, said turntable rotating about a central axis;

means for incrementally rotating said turntable about said axis to position said vacuum chucks in first, second, third, and fourth rotational positions;

loading means for transferring uninspected semiconductor devices from storage trays to a first conveyor means for conveying the uninspected semiconductor devices to said vacuum chucks in the first rotational position;

said first conveyor means including a first elongated tray having a plurality of compartments, each compartment for containing a semiconductor device and means for incrementally moving said first elongated tray towards said vacuum chucks in the first rotational position;

means for translating said vacuum chucks in the first, third, and fourth rotational positions between (i) a lowered position for engaging and releasing a semiconductor device before and after inspection, respectively, and (ii) a raised inspecting position for inspection of a semiconductor device when said vacuum chucks are in the second rotational position;

inspection means for inspecting the exterior of a semiconductor device including imaging means for forming an image of a semiconductor device held by said vacuum chucks in the second rotational position and image analyzing means for analyzing the image formed by said imaging means and for determining whether an imaged semiconductor device is acceptable;

second conveyor means for conveying acceptable semiconductor devices away from said vacuum chucks when in the third rotational position, said second conveyor means including a second elongated tray having a plurality of compartments, each compartment for holding a semiconductor device, and means for incrementally moving said second elongated tray away from said turntable when said vacuum chucks are in the third rotational position;

unloading means for transferring acceptable inspected semiconductor devices from said second elongated tray to storage trays;

discard means for receiving unacceptable semiconductor devices when said vacuum chucks are in the fourth rotational position; and

control means responsive to said inspection means for controlling said means for incrementally rotating said turntable and said means for translating to release an acceptable semiconductor device from a vacuum chuck in the third rotational position and to release an unacceptable semiconductor device from a vacuum chuck in the fourth rotational position to said discard means.

2. An apparatus as claimed in claim 1 wherein the first, second, third, and fourth rotational positions are located 90°

apart, and said four vacuum chucks are disposed equally distant from the axis of said turntable and from each other.

3. An apparatus as claimed in claim 1, wherein said imaging means is a vidicon camera.