JPS60245139A - Mounting device of semiconductor pellet - Google Patents

Abstract

PURPOSE:To recognize a pellet in a short time with high recognizing accuracy even when the pellet becomes large by using a plurality of ITV cameras of variable magnifications and simultaneously calculating different magnifications for the same image. CONSTITUTION:ITV cameras 20, 21 have variable magnifications, of the magnification of the degree for taking the entire pellet and of high magnification of sufficiently taking the angle of the pellet. When the camera 20 is, for example, set to high magnification, a full-cut wafer without elongation can be sufficiently observed black in a dicing groove width, after binarized in an image processor 12, calculated by a calculation processor 13, and the position can be corrected by an XY table controller 14. On the other hand, when the entire pellet is taken with low magnification by the camera 21 simultaneously upon positioning, an improper mark can be detected, notch, crack or inclination of the pellet can be detected, and judged for the propriety by the processor 13. Thus, even in the elongating wafer of a full-cut dicing, it can be recognized in high recognizing accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical preference] The present invention relates to a semiconductor pellet mounting device.

[Prior art]

As shown in FIG. 4, the conventional pellet mount device illuminates a semiconductor pellet (1) with an illumination device (10), uses the reflected light to take an image of the pellet with one I'lV camera (11), and displays the image. A binarized image is created by showing the pellet part white and the dicing grooves between the pellets black. Next, using the image processing section 12 and the arithmetic processing section 18, the fifth
In the binarized image shown in the figure, the pellet center value is calculated from the pellet outer shape, and the correction value of the pellet position, the presence or absence of defective marks 17, the dicing width 16, and chips, cracks, and tilt of the pellet are determined. After determining the quality, the XY table 4 on which the Ueno ring 2 is placed is controlled by the XY table control section 14 to perform fine adjustment, and defective pellets are moved by one pellet pitch. After correction, the good pellets are continuously mounted on the lead frame 7 on the feed unit 8 by the mount head 5. 3 is a ring mounting table, and 6 is a head xY table, which is controlled by an XY table controller 14. However, in such a mounting device, ITV
In order for the entire pellet to be captured on the image pickup device of the camera, if the pellet size becomes large, the entire pellet will not be captured on the TV monitor 15 unless the zoom lens 90 magnification is reduced.

For example, if the resolution is lOμ, a normal ITV camera (with an imaging area of 320 x 240 bits) will capture 2.
It can only recognize pellets up to 6 m long, and for pellets larger than that, the resolution must be increased, that is, the magnification must be lowered. If the magnification remains high, it is necessary to align the second point, which takes too much recognition time. When the magnification is decreased, the resolution of the imaging device increases, which causes a problem in that the mounting accuracy deteriorates. When the magnification is reduced, the dicing grooves, which are usually about 3 to 40μ, become too small compared to the pellet size, and when the black and white binary image is converted into a black and white image during image processing, the black part disappears, so it is necessary to enlarge the wafer. A pellet position correction mechanism was required to do so.

[Purpose of the invention]

An object of the present invention is to eliminate the above-mentioned drawbacks, and to provide a mounter equipped with a recognition device that has high recognition accuracy even when the pellet becomes large, and that positions the pellet and determines its acceptability in a short recognition time without enlarging the wafer. There is a particular thing.

[Structure of the invention]

The present invention includes a plurality of ITV cameras with variable magnification that image the surface of the same semiconductor pellet, an illumination device, an image processing unit that processes images captured by the cameras, and corrects the pellet position based on the image data. This is a semiconductor pellet mounting device characterized by having an arithmetic processing unit that determines acceptability and an XY table that corrects the pellet position based on the correction value.

[Explanation of Examples]

Next, the present invention will be explained using examples and with reference to the drawings.

In FIGS. 1 to 3, the same components as those in FIGS. 4 and 5 will be described with the same reference numerals.

FIG. 1 is a schematic block diagram of an embodiment of the present invention. In FIG. 1, the present invention uses two ITV cameras that simultaneously capture two images in which the reflected light of the pellet illuminated by the illumination device IO is reflected in two directions by a prism 19 through a lens system 18. The magnification of each ITV camera 20 and 21 is variable, and there are two types of magnification: one that shows the entire pellet, and one that is high enough to show the corners of the pellet sufficiently large.
Make sure the corners of the pellet are visible.

For example, assume that the ITV camera 20 has a high magnification and an image is projected on the image pickup tube of the camera 20 as shown in FIG. Since the camera 20 has a high magnification, even on a fully cut wafer without enlarging, the dicing groove width 16 appears sufficiently black, and after the image processing section 12 performs binarization processing, the arithmetic processing section 13 performs arithmetic processing. Position correction can be performed with high precision by the XY table control section 14.

On the other hand, as shown in Figure 3, at the same time as positioning, the ITV camera 2
1, when the entire pellet is imaged at low magnification, the defective mark 17 is detected, and chips, cracks, tilts, etc. of the pellet are detected, and the arithmetic processing unit 13 determines whether the pellet is good or bad.
When a good pellet is to be picked up by the mount head 5, a start signal for the mount head 5 and the XY table 6 is issued. If the pellet is defective, mark it with an X on the ring.
A signal is sent to the Y table 4, the pellet pitch is skipped, and the adjacent pellet is recognized.

In other words, positioning can be performed in a short time by processing the same image at different magnifications at the same time.

〔Effect of the invention〕

As explained above, since the present invention simultaneously processes the same image at different magnifications, it can be recognized with high recognition accuracy regardless of the pellet size, even on wafers without enlarging in full-cut dicing, and the recognition time can be reduced. This has the effect that the second point alignment can be performed in half the time.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram showing an embodiment of the present invention, Figure 2 is a diagram of a high magnification camera after image processing, Figure 3 is a diagram of a low magnification camera after image processing, and Figure 4 is a conventional diagram. FIG. 5 is a diagram showing an example of a binarized image after image processing. l...Semiconductor pellet, 2...Wafer ring, 8...
...Ring stand, 4...XY table, 5...Mount head, 6 Head section XY table, 7...Lead frame, 8 Feeding unit, 9...Zoom lens, 1
0...Lighting device, 11-...ITV camera, 12...
Image processing section, 13... Arithmetic processing section, 14. ...XY
Table control unit, 15...TV monitor, 16...
Dicing groove width, 17... Defective mark, 18 Lens system, 19... Prism, 20... TTV camera, 2
1...ITV camera. Patent applicant: NEC Corporation

Claims (1)

[Claims] (1) A plurality of ITV cameras with variable magnification that image the same semiconductor pellet surface, an illumination device, an image processing unit that processes images captured by the cameras, corrects the pellet position using the image data, and 1. A semiconductor pellet mounting device comprising: an arithmetic processing unit that determines the quality of the semiconductor pellet; and an XY table that corrects the pellet position based on the correction value.