SINGULATION APPARATUS COMPRISING AN IMAGING DEVICE

• US 20150194354A1
• Filed: 01/03/2014
• Published: 07/09/2015
• Est. Priority Date: 01/03/2014
• Status: Active Grant

• Current Assignee: Asmpt Singapore Pte Limited
• Original Assignee: Chi Wah Cheng
• Inventors: CHENG, Chi Wah, TANG, Hoi Shuen, LIU, Chun Kit
• Granted Patent: US 9,263,352 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B23D 59/002 for the position of the saw blade B27B5/36 and B27B9/02 take precedence
• CPC Class Codes: B26D 1/18 mounted on a movable carriage
• CPC Class Codes: B26D 5/007 Control means comprising cameras, vision or image processing systems
• CPC Class Codes: B26D 5/06 by electrical means
• CPC Class Codes: B28D 5/022 by cutting with discs or wheels
• CPC Class Codes: H01L 21/67092 Apparatus for mechanical treatment or grinding or cutting, see the relevant groups in subclasses B24B or B28D
• CPC Class Codes: H01L 21/67259 Position monitoring, e.g. misposition detection or presence detection
• CPC Class Codes: H01L 21/681 using optical controlling means
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps
• CPC Class Codes: Y10T 83/162 With control means responsive to replaceable or selectable information program

Abstract

Disclosed is a singulation apparatus for cutting a workpiece. The singulation apparatus comprises: i) a processor; ii) at least one chuck device for securing the workpiece to be cut; iii) a cutting device spaced from the at least one chuck device by a separation distance, the cutting device being for cutting the workpiece secured to the at least one chuck device; and iv) an imaging device operable to capture one or more images comprising the cutting device and a reference feature. In particular, the processor is configured to determine a separation distance between the cutting device and the reference feature based on the one or more images as captured by the imaging device, to thereby determine the separation distance between the cutting device and the workpiece as secured to the at least one chuck device.

Claims

1. A singulation apparatus for cutting a workpiece, comprising:

a processor;

at least one chuck device for securing the workpiece to be cut;

a cutting device spaced from the at least one chuck device by a separation distance, the cutting device being for cutting the workpiece secured to the at least one chuck device; and

an imaging device operable to capture one or more images comprising the cutting device and a reference feature,

wherein the processor is configured to determine a separation distance between the cutting device and the reference feature based on the one or more images as captured by the imaging device, to thereby determine the separation distance between the cutting device and the workpiece as secured to the at least one chuck device.

2. The singulation apparatus of claim 1, wherein the processor is configured to determine from the one or more images captured by the imaging device, the number of pixels corresponding to the separation distance between the cutting device and the reference feature, and apply a pixel-distance correlation factor to the determined number of pixels to determine the separation distance between the cutting device and the reference feature.

3. The singulation apparatus of claim 2, wherein

the cutting device is configured to be positioned to define a known separation distance between the cutting device and the reference feature;

the imaging device is configured to capture one or more images comprising the reference feature and the cutting device spaced from the reference feature by the known separation distance; and

the processor is configured to determine from the one or more images captured by the imaging device, the number of pixels corresponding to the known separation distance between the cutting device and the reference feature, to derive the pixel-distance correlation factor.

4. The singulation apparatus of claim 3, wherein the known separation distance is 1 mm.

5. The singulation apparatus of claim 1, wherein the reference feature is arranged in relation to the at least one chuck device by a known positional relation.

6. The singulation apparatus of claim 1, wherein the reference feature is part of the at least one chuck device.

7. The singulation apparatus of claim 1, wherein the imaging device is a camera.

8. The singulation apparatus of claim 1, wherein the imaging device is a laser scanner.

9. The singulation apparatus of claim 1, wherein the cutting device comprises a circular rotatable blade for cutting the workpiece.

10. A method of determining a separation distance between a workpiece secured to a chuck device and a cutting device for cutting the workpiece in a singulation apparatus, the method comprising the steps of:

capturing one or more images comprising the cutting device and a reference feature; and

determining the separation distance between the cutting device and the reference feature based on the one or more images as captured; and

thereby determining the separation distance between the cutting device and the workpiece as secured to the chuck device.

11. The method of claim 10, wherein the step of determining the separation distance between the cutting device and the reference feature comprises the steps of:

determining the number of pixels corresponding to the separation distance between the cutting device and the reference feature from the one or more images captured by the imaging device; and

applying a pixel-distance correlation factor to the determined number of pixels to determine the separation distance between the cutting device and the reference feature.

12. The method of claim 11, further comprising the steps of:

positioning the cutting device to define a known separation distance between the cutting device and a reference feature;

capturing one or more images comprising the reference feature and the cutting device spaced from the reference feature by the known separation distance; and

determining from the one or more images captured, the number of pixels corresponding to the known separation distance between the cutting device and the reference feature, to derive the pixel-distance correlation factor.

13. The method of claim 12, wherein the known separation distance is 1 mm.

14. The method of claim 10, wherein the reference feature is arranged in relation to the chuck device.

15. The method of claim 10, wherein the reference feature is part of the chuck device.

16. A method of calibrating a singulation apparatus, the singulation apparatus comprising i) a cutting device for cutting a workpiece and ii) at least one chuck device for securing the workpiece to be cut, the method comprising the steps of:

positioning the cutting device to define a known separation distance between the cutting device and a reference feature;

capturing one or more images comprising the reference feature and the cutting device spaced from the reference feature by the known separation distance; and

determining from the one or more images captured, the number of pixels corresponding to the known separation distance between the cutting device and the reference feature, to derive a pixel-distance correlation factor.

17. The method of calibrating the singulation apparatus of claim 16, wherein the known separation distance is 1 mm.

18. The method of calibrating the singulation apparatus of claim 16, wherein the reference feature is arranged in relation to the at least one chuck device by a known positional relation.

19. The method of calibrating the singulation of claim 16, wherein the reference feature is part of the at least one chuck device.