JPS59145910A - Measuring method of working error in precise work - Google Patents

Abstract

PURPOSE:To measure easily and exactly a working error in a precise work by comparing a theoretical Gantt chart of a regular polygon with a product Gantt chart of a regular polygon. CONSTITUTION:Centroid coordinates Gx, Gy, an area, a Fourier spectrum and a circumferential length of a product Gantt chart 2 are derived. In the same way, centroid coordinates, an area, a Fourier spectrum and a circumferential length of a theoretical Gantt chart are derived. Subsequently, a position shift value of a product pattern is derived by comparing two centroid coordinates, and a magnification error value of the product pattern is derived by comparing two areas. Next, a rotational error value of the product pattern is derived by comparing two Fourier spectrums, and a graphic deformation rate of the product pattern is derived by comparing ratios of two circumferential lengths and areas. By processing in this way, a working error in a precise work can be measured easily and exactly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring machining errors of precision workpieces manufactured using a plurality of overlapping patterns, such as machined C-chips and multicolor printed matter.

In general, IC chips and multicolor printed matter are manufactured by overlapping multiple patterns that are each copied from an original image, and processing errors include errors due to differences in the reproduction magnification of each duplicate pattern, and errors due to the overlap of each duplicate pattern. It appears as an accumulation of errors due to time lag and/or errors due to distortion of each replicated pattern, but in order to judge whether the product is acceptable or not, it is necessary to determine the extent of the accumulated error, that is, the processing error. I need to know. In order to find out the extent of conventional machining errors, the char (for example, as shown in Fig. 1) is It is used. These chars) P take various forms as illustrated in FIG. 2 depending on the degree of occurrence of the various errors mentioned above.

That is, fa) t (t) j in Fig. 1 shows the form when each copy pattern is faithfully copied to its original image without any processing error and is correctly superimposed, and f in Fig. 2
a) and (b) are the forms when a part of the duplicate pattern is shifted in the XY direction, (C) and (at are the forms when all the duplicate patterns are shifted in the XY directions, and (el and (fr respectively indicate the form in which a part of the replicated pattern is shifted and distorted in the rotational direction. Conventionally, among these chars 1-P, at least one of the form shown in FIG. 1(b) was visually observed to determine whether the product was acceptable or not.Since processing errors in machining C-chips and multicolor printed matter are actually extremely minute and intermittently, visual inspection as described above requires a great deal of skill. In addition, differences in judgment results due to differences in observers occur, and high judgment accuracy cannot be expected.In order to eliminate the drawbacks of the conventional method as described above, the present invention aims to eliminate Gantt Char 1. is the barycenter coordinate 2 of the Gantt chart expressed on the product so as to form a regular polygon.
Calculate the various errors mentioned above by calculating the area, Fourier spectrum, and circumference, and comparing these with the center of gravity coordinates of the regular Gantt chart. This will be explained in detail below based on the illustrated embodiment.

First, Figure 3 shows an example in which an IC product is manufactured by superimposing three types of duplicate patterns.1, Tail. In the figure, IA, IB, and 1c are isosceles triangular Gantt Char 1 and elements 1a, lb, respectively, at predetermined positions and in a predetermined order.
and 1c, a first pattern plate 1, a second pattern plate, and a third pattern plate,
As shown in Figure 1d, the construction Cf! These first, second and third pattern plays) IA, J-
It is manufactured by a well-known method using B and 1c. In this case, the pattern (not shown) displayed on product 1 is such that the parts (for example, the corners of the pattern plate) that should be used as references for each putter 7f L/-) LA, 1B, and 1c (for example, the corner of the pattern plate) completely match. Since the Gantt chart 2 is completed by aligning the lines as shown in the figure, if the virtual reference lines X and y shown in FIG.
Gantt chart elements 1a, lb with respect to c.

It is expressed as an equilateral triangle consisting of lc. Each pattern of each pattern plate l A , l B , I O is reproduced from the original image of the first plate l], the second plate, and the third plate, respectively, and at this time, each Gantt chart element 1a5゜i b , 1. C is displayed as a line image of the same density and tone using means such as plate making, photography, phototypesetting machine, drawing machine, etc.

In this way, the Gantt chart expressed in the special electric part of the product) is printed on the first pattern plate IA. , second putter 7 play V-)lB and third pattern play 1-1 c
The patterns reproduced above are variously deformed due to differences in position and size, deviation in rotational direction, and deformation rate, and their attachments, but these are caused by correctly overlapping the three original images. The measurement is performed by analyzing and comparing the Gantt chart created by (hereinafter referred to as the theoretical Gantt chart 1) and the product Gantt chart 2 using the method described below.

That is, in order to perform this ratio iIj9, first, as shown in FIG. As shown in Fig. 5, the above mold/shape/position is used as the origin, and the Fu IJ process is developed for the angle θ, and the product is finished!
・Determine the Fourier spectrum of chart 2, and further calculate the coordinates (X
i, yi) and the center of gravity position (Gx, Gy), and similarly calculate the center of gravity position of the theoretical Gant chart,
Area, Fourier spectrum + coordinates of each Mtta point and length of each side are determined in advance. The center of gravity position of product Gantt Char 1 and 2 thus obtained (Qx, Gy)
By comparing the position of the center of gravity of the theoretical gun i-chart (which coincides with the intersection position of the virtual reference lines x and y mentioned above), the first pattern and the second pattern according to the first pattern play 1 and 1A are determined. Flare 1- The size of the positional deviation of the superposition of the second pattern by I B K and the third pattern by the third pattern plate IC can be measured, and the area of the product Gantt chart 20 is F, and the area of the theoretical Gantt chart is When G is G, the relationship between F and G is F=β2G(
However, β is the magnification), so by comparing the area of the product Gantt chart 20 obtained as above and the area of the theoretical Gantt chart, it is possible to determine the result of polymerization of the first, second and third patterns The resulting composite pattern (
The magnitude of the magnification error of the product pattern) can be measured and determined by comparing the Fourier spectra of the product Gantt charts 1 and 2 obtained as described above with the Fourier spectrum of the theoretical Gantt chart. The magnitude of the deviation angle (rotation error) in the rotational direction from the normal position can be measured, and furthermore, the circumference of the theoretical Gantt char 1 can be defined as l. .

When the circumference of the product Gantt chart is 4, the figure deformation rate is expressed as (12/F) / (lo2/G). In this case, the theoretical Gantt chart is an equilateral triangle, so (
eo2/G)=4x3tan-, and D=(12
/F)/] 2 ta,nH, the magnitude of distortion of the composite pattern can be measured. FIGS. 7 and 8 show an example of an apparatus for measuring and displaying the above-mentioned positional deviation, magnification error, 5-rotation error, and figure deformation rate, and determining whether the product is acceptable or not. In Fig. 7, 3 is a movable bed for transporting the Gantt chart 2 represented on the product 1 to the measurement position, and 4 is a movable bed suitable for illuminating the Gantt chart 2 that has been brought to the measurement position. 8 is an illumination light source system arranged to project illumination light onto the Gantt chart 2 from a direction of 45 degrees, 5 is an optical system for guiding the light from the Gantt chart 2 to the sensor 6, and 7 in FIG. is the product Gantt Char 1 and 2 based on the output from sensor 6.
0 barycentric coordinates 2 image processing unit for calculating the area, Fourier spectrum and circumference, 8 a control device for controlling the illumination light source system, 9 barycentric coordinates of the theoretical Gantt chart.

A memo IJ-,], which stores data regarding the area, Fourier spectrum, and circumference, sequentially compares various data from the image processing unit 7 with various data from the memory 9 to determine the positional deviation and magnification error 7 of the product pattern. A central processing unit 11 that calculates rotation error and figure deformation rate values displays the various error values mentioned above based on the output from the central processing unit, and also displays whether the errors are within preset tolerance values. This display 2 discrimination and control 1 device is configured to display whether the product is acceptable or not, and to issue a control signal to stop the operation of the production line when a rejected product is produced. The above-mentioned apparatus can be used in a production line as a real-time unit, but this does not limit the invention, and various modifications and modifications are possible.

The above has described an example in which the product pattern is constructed by overlapping three types of patterns.
There is only one type of overlapping pattern.

There may be two types or four or more types of errors, and the various types of errors mentioned above can be obtained in the same manner as in the case described above. Therefore, the figure deformation rate is (g2.f=) / 4 n tan
-1] (where n is an integer of 3 or more), and when two types of patterns are used, n = 4 and the Gantt chart element becomes a right-angled isosceles triangle. Also, if you use a Φ type pattern, just insert the Gantt chart to that size.

The above is explained using an IC product as an example of a precision processed product.
An example in which the present invention is applied to color matching of multicolor printed matter will be described below. In the case of multicolor printing plate making, the color types are Y (yellow), M (red), C (blue), and B.
Since four colors (black) are used, the cylinder is not shown in Figure 9.

At least four 7linders are required for M, C, and B, and printing is performed by feeding the printing paper 12 in the direction of the arrow by each of the four printing pressure rollers 13 and span rollers 14 as shown in the figure. . FIG. 9 shows four printing plates Y, , Y7. Y3 and Y.

and Gantt chart elements Ya and Yb corresponding to these.

It is an enlarged development view of a Y cylinder provided with Yc, Yd and a plurality of registers ys located on the temporary rest reference lines x and y.
Gantt chart elements and registers are provided on the surface of each of the seven Linders M, C, and B in exactly the same way, and when printing of each color is completed, a Gantt chart 1 as shown in FIG. 11 is placed on the printing paper 12. -15, ], ]6, 17.

] 8 is now expressed. In this case, Gantt chart +5.16 and +17.18 also serve as low, medium, and high density color keys, respectively, and are also used to adjust the overall tone of the printed surface.

These Gantt charts 15, ], ]6, ],
Since 7 and 18 correspond to the product Gantt chart described above, the positional deviation of the composite pattern of the screen printed by each cylinder of Y, M, C, and H.

Measurement and evaluation of magnification error 7 rotation error and figure deformation rate, determination of acceptance as a product, etc. have already been explained, so detailed explanation will be omitted.

Although FIG. 9 shows the means for measuring the product Gantt charts l 5 , l 6 , -17, and 18 expressed on the printed paper 12, the illumination light source system, optical system, and sensor are They are designated by the same reference numerals as in FIG. The sensor 6 in this case is configured as a line sensor extending in the width direction of the printing paper 12. In addition, in the case of multicolor printing, shape deformation occurs depending on the amount of illumination light emitted from the illumination light source system 4, but in reality, the control device 8 shown in Figure 7
The light source system 4 is controlled so that each color has a light amount that does not cause graphic deformation.

As is clear from the above description, according to the present invention, it is possible to easily and accurately measure various errors caused by overlapping, especially for multi-layer, high-density precision processed products, and Since it becomes possible to automatically judge whether or not a product is acceptable on the production line, it can be extremely effective in fields such as the production of multilayer high-density ICs and high-grade multicolor printing.

Furthermore, in the case of the present invention, the geometric deformation rate can be measured regardless of the magnification, and the standard value is the theoretical value, so extremely high precision opening is possible. There is also the advantage that the dedicated chart that was inserted into the system is no longer needed.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing different examples of Gantt charts expressed in products manufactured by overlapping multiple duplicate patterns, and Figure 2 is an illustration of modified examples of Gantt charts expressed due to various processing errors. Figure 3 is an explanatory diagram showing an example where an RC product is manufactured by superimposing three types of duplicate patterns, and Figures 4 to 6 are explanations of the analysis content of the product Gantt chart. 7 is an explanatory diagram showing an example of a method for measuring a product Gantt chart, FIG. 8 is a block diagram of a processing device that processes various measurement data of a product Gantt chart, and FIG. FIG. 10 is a developed view of a cylinder used in the rotary press shown in FIG. 9, and FIG. 11 is a plan view of a main portion of multicolor printing paper. ■...Product, la, lb, lc...Gantt chart element, 2, 15, 16, 17, +8...
・・Product Gantt chart, 3・・・Mobile pet, 4・
...Illumination light source system, 5...Optical system, 6...Sensor, 7...Image processing unit, 8...Control device, 9...Memory, 10...・Central processing unit,
11... Display 7 discrimination and control device, 12... Printing paper (product), 13... Printing pressure 0-7.14...
span roller. Figure 1 (a) (b) Figure 2 (a) (b) (c)
(d) Ce), (f) Figure 3 Figure 4 Figure 5 Off Figure 18 Figure 19 Figure 2

Claims (1)

[Claims] a step of determining the barycenter coordinates 9 area, Fourier spectrum, and circumference of a theoretical Gantt chart forming a regular polygon; a step of obtaining barycenter coordinates 2 area, Fourier spectrum, and circumference of a product Gantt chart that should form a regular polygon; A step of comparing the coordinates of the center of gravity of the press to obtain a positional deviation value of the product pattern, a step of comparing the area of the press to obtain a magnification error value of the product pattern, and a step of comparing the Fourier spectra of the press to determine the product pattern. A method for measuring machining errors in precision workpieces, the method comprising: determining a rotational error value of the presser; and determining a figure deformation rate of a product pattern by comparing the ratio of the circumferential length and area of the press.