CN101058164A

CN101058164A - Image calibrating method used for chip dicing machine

Info

Publication number: CN101058164A
Application number: CN 200610025803
Authority: CN
Inventors: 张昕
Original assignee: SHANGHAI FUAN FACTORY AUTOMATION CO Ltd
Current assignee: Shanghai Electric Machine Tools & Engineering Co., Ltd.
Priority date: 2006-04-18
Filing date: 2006-04-18
Publication date: 2007-10-24
Anticipated expiration: 2026-04-18
Also published as: CN100439039C

Abstract

The invention relates to the image calibration method for a chip scribing system that uses single CCD camera with graphic data collecting system, serial circulation execution adding coordinate values X and Y on one processing baseline, computing the included angle tolerance theta 1 of the working piece processing baseline and the machine processing baseline, instructing the return of the chip scraper on the working platform, rectifying the included angle error, selecting the X and Y values of two points at both ends of the longest processing baseline, computing the included angle error theta 2 of the whole processing baseline and the machine processing baseline, instructing the chip scraper working platform returning to rectify the included angle error, and finally centering alignment for the tool and work piece cutting. Through second computation and rectification angle theta, it can speed up the adjustment of the single crystalline cutting position with improved cutting precision.

Description

A kind of image calibrating method that is used for chip dicing machine

Technical field

The present invention relates to IC chip system integrated technology application, be specifically related to a kind of image calibrating method that is used for chip dicing machine.

Background technology

In the manufacture craft of IC chip, get off at present with the IC chip cutting that scribing machine will be printed on the single-chip.Single chip fitly is arranged in (as Fig. 1) on the single-chip, requires the cutting track of scribing machine emery wheel can only be confined in the two cutting belt zones of going between the IC chips during cutting.The cutting belt width is generally 0.04mm～0.05mm, and the groove width after the emery wheel cutting is generally 0.03mm～0.035mm.This just require on the single-chip cutting belt and scribing machine X to movement locus parallel; The cutting belt center overlaps with the grinding wheel mid-depth.

Vision positioning system on the scribing machine is to solve this technological problems.Prefabricated cross datum line on the scribing machine display screen, and as the background of CCD photographed images.Can preset CCD camera lens with mechanical means, the horizontal line that makes the cross datum line and scribing machine X be to parallel, and overlap (cross datum line modulated become machine tooling datum line) with the grinding wheel mid-depth.Single-chip is placed on the scribing machine workbench, and the image that the CCD camera system is adopted is thrown on the display screen, as shown in Figure 2.Manually control scribing machine work table rotation makes cutting belt and planche cross line parallel; Manually control scribing machine Y makes the cutting belt center overlap (as shown in Figure 3) with planche cross line center to motion.

Because the CCD multiplication factor requires to be not less than 100 times, (multiplication factor is little generally to get 100～200 times, the center misalignment), to amplify 100 times is example, display image is of a size of 150mm * 165mm, the cutting belt width amplifies the back and be of a size of 4mm (the cross hairs live width is generally 0.4mm by the decision of kinescope pixel) on screen, and the single-chip actual area that CCD captures has only 1.5mm * 1.65mm.Just screen is gone up 165mm cutting belt length, and actual size has only 1.65mm.Proofreading and correct and the planche cross line parallel with the range estimation of the image of 1.65mm length, if its error has only cross hairs live width size, also be very normal, and actual Cutting Length is very big, and 6 " (inch) sheet X stroke is 165mm, and so omnidistance parallel misalignment reaches 40mm.So must mobile repeatedly X-axis, θ axle and Y-axis, progressively adjust, the planche cross line is included in the omnidistance cutting belt zone, and placed in the middle as far as possible.In fact use the intensified image of 1.65mm length, proofread and correct the cutting belt of 165mm length, operation is that very cumbersome, final precision also is not high.

Advanced both at home and abroad for this reason scribing machine has all adopted twin-lens CCD camera system.(establish apart a), two camera lenses are gathered one group of image to two camera lenses separately, render to two zones (as shown in Figure 4) about display screen respectively at a distance of certain distance.Two cutting belt not necessarily link to each other on screen about on the display screen, if moreover about two cutting belt also not necessarily same cutting belt that link to each other.Manually control the scribing machine work table rotation, two cutting belt are parallel to the planche cross line about making, and are connected to a cutting belt, manually control scribing machine Y to moving, and make the planche cross line overlap (as shown in Figure 5) with the cutting belt center.

Because two cutting belt are actual in being a (supposing a=55mm) on the display screen, estimating and adjusting error also is cross hairs live width size, cuts omnidistance length 165mm, aims at the omnidistance parallelism error in back and reduces to 1.2mm.Omnidistance back and forth more mobile X-axis and fine motion θ axle, Y-axis have just been finished the work of workpiece location for several times.Find out that therefrom a distance is big more, easy more adjusting, but a big require scribing machine X stroke also should strengthen.In addition because the single-chip size has different size from 4 "～12 ", and the excessive twin-lens of a can not capture small dimension wafer epigraph simultaneously, also just can't the calibration of workpieces position; The too small big specification list wafer initial adjustment error of a increases, and regulates efficient and precise decreasing.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of image calibrating method that is used for chip dicing machine, adopts single CCD camera, regulates efficient and precision but can improve.

For solving the problems of the technologies described above, the inventive method chips scribing machine uses single CCD camera, the graph data acquisition system is housed on this chip dicing machine, sequential loop is carried out following steps: two point coordinates value X, Y on the same machining benchmark line in the workpiece that step 1, acquisition chip scribing machine are handled calculate angle error θ between workpiece machining benchmark and machine tooling benchmark by setting equation ₁, and instruct this chip dicing machine work table rotation, with finishing angle error θ ₁Step 2, gather coordinate figure X, Y at 2, and calculate omnidistance machining benchmark line of workpiece and machine tooling datum line angle error θ by setting equation at the two ends of the longest machining benchmark line of handling of workpiece ₂, and instruct this chip dicing machine work table rotation, to repair omnidistance angle error θ ₂Step 3, to the cutter and the work piece cut band center of chip dicing machine.

The inventive method is by the process secondary calculating and repair the θ angle, can accurately adjust the single-chip cutting position fast, has improved the work cutting accuracy.

Description of drawings

Fig. 1 is the single-chip schematic diagram;

Fig. 2 is the CCD camera system is adopted in the traditional handicraft an image situation when throwing into traditional die scribing machine display screen;

Fig. 3 manually controls the scribing machine work table rotation in the traditional handicraft, make cutting belt and planche cross line parallel; Manually control scribing machine Y makes the cutting belt center overlap situation with planche cross line center to motion;

Fig. 4 is the display screen that traditional handicraft chips scribing machine adopts twin-lens CCD camera system;

When Fig. 5 is traditional handicraft chips scribing machine employing twin-lens CCD camera system, manually adjust cutting belt, make the situation that overlaps with the cutting belt center.

Fig. 6 is in the inventive method, any 2 coordinate figure situation on the cutting belt in the system acquisition image;

Fig. 7 is the signal of the inventive method flow chart.

The specific embodiment

The present invention is further detailed explanation below in conjunction with accompanying drawing.

Adopting the chip dicing machine of the inventive method to use single CCD camera, and the graph data acquisition system is housed, increased the image data acquiring processing capacity, can the cross hairs central point be the datum mark of data acquisition, can gather the coordinate dimension of arbitrfary point on the workpiece.After the image on the single-chip is rendered on the display screen, as Fig. 6, shown in Figure 7, at first to gather in the image coordinate figure of any 2 points (A, B) on the cutting belt respectively, system can calculate the angle theta of cutting belt and planche cross line, i.e. θ=tg automatically then ^-1((Y ₂-Y ₁)/(X ₂-X ₁)), system command scribing machine workbench rotates θ automatically, cutting belt and planche cross line is transferred to automatically is parallel to each other; Because system has increased segmentation scale (is radix with display screen matrix unit) on vertical cross hairs, therefore can manually control mobile Y-axis,, regulate that the planche cross line is overlapped with the cutting belt center by the segmentation scale on the vertical cross hairs.And then manually control mobile X-axis, cutting belt two ends at maximum Cutting Length, gather the two-end-point coordinate respectively, system still calculates omnidistance angular errors again by above-mentioned equation, and instruction works platform automatic dressing, utilize vertical cross hairs segmentation scale, regulate that accurately cutting belt center whole process is overlapped with the planche cross line.Revise through secondary θ angle,, just finish single-chip location work on the scribing machine with vertical cross hairs center adjustment.

In sum, the inventive method has overcome the deficiency in the traditional handicraft, solved the problem that needs accurately to adjust fast the single-chip cutting position in the actual process, no matter and workpiece size, can both revise workpiece angular errors (satisfy the positioning requirements of the specification list wafer that varies in size simultaneously, and adjust omnidistance error) with the maximum Cutting Length of workpiece two ends coordinate figure with the workpiece maximum spacing.And the thin scale function of vertical cross hairs, improved the accuracy of alignment of emery wheel cutting groove and work piece cut band.

Claims

1, a kind of image calibrating method that is used for chip dicing machine, this chip dicing machine uses single CCD camera, it is characterized in that, the graph data acquisition system is housed on this chip dicing machine, following method is carried out in described systematic order circulation, comprise: step 1, gather in the workpiece that this chip dicing machine handles two point coordinates value X, Y on the same machining benchmark line, calculate angle error θ between described workpiece machining benchmark and machine tooling benchmark by the setting equation of angle error ₁, and instruct this chip dicing machine work table rotation, with finishing angle error θ ₁The two ends of step 2, the longest machining benchmark line of workpiece handled at described chip dicing machine are gathered coordinate figure X, Y at 2, and calculate omnidistance machining benchmark line of described workpiece and machine tooling datum line angle error θ by setting equation ₂, and instruct this chip dicing machine work table rotation, to repair omnidistance angle error θ ₂Step 3, to the cutter and the described work piece cut band center of described chip dicing machine.

2, the image calibrating method that is used for chip dicing machine according to claim 1, it is characterized in that, described machine tooling datum line is the cross datum line, the width of this cross datum line line is got minimum pixel unit, i.e. 1 pixel, and on vertical cross datum line, be that unit makes thin scale with the pixel.

3, the image calibrating method that is used for chip dicing machine according to claim 1 and 2 is characterized in that, the setting equation of described angle error is: θ=tg ^-1((Y ₂-Y ₁)/(X ₂-X ₁)).