JPH08194736A - Cad system provided with collation function for actual article - Google Patents

Abstract

PURPOSE: To designate more than one areas on an etching product pattern, to input a picture there and to locally overlap it with CAD data corresponding to a design pattern. CONSTITUTION: An actual article CAD system which overlaps more than two CAD data and collates them is provided with a navigation function which displays reference CAD data as the design pattern of a lead frame having a clean reference point on a monitor screen, calculates the reference point of the lead frame which corresponds to the reference point, designates prescribed areas A and C on reference CAD data displayed on the monitor screen and therefore designated the photographing areas of the lead frame, which correspond to the area concerned to match the view of a camera with the photographing area designated by referring to the both reference points. Thus, the image of the actual article pattern of the photographing area where the view is matched is inputted and the raster image data is converted into corresponding CAD data. Then, it is overlapped with the designated area of reference CAD data on the monitor screen to display it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention arbitrarily sets a design pattern of an etching product, an etching pattern of a product manufactured based on the design pattern, and a two-dimensional pattern of an original plate and a plate making used during the manufacturing of the product. , Which can be effectively used for product design and quality control based on the data obtained by comparing each other on the computer screen and specify the area of the actual pattern to be captured and measured on CAD. The present invention relates to a CAD system having an in-situ matching function.

[0002]

2. Description of the Related Art ICs to be mounted as etching products
There is a lead frame used to electrically connect to the (integrated circuit) chip.

FIG. 22 shows an example of a lead frame for one chip as viewed from one side. A die pad (island) 10 for mounting a chip (not shown) is located at the center of the lead frame. The die pad 10 is supported by an outer frame 12 via a tab suspension bar 14, and an inner lead 16 is arranged around the die pad 10 with its tip close to the die pad 10, and an outer lead continuous with the inner lead 16 is provided. 18 is the above-mentioned outer frame 1 via the dam bar 20 etc.
Supported by 2. Also, the inner lead 16 has
A fixing tape 22 made of plastic is attached to prevent deformation of the leads 16. The broken line in the figure is the mold line.

Taking the lead frame as an example, an outline of the steps from etching product design to product completion is shown in FIG.
It becomes like 3.

CAD of lead frame pattern design
(Computer Aided Design), first, CAD data of the same product (A) as the target product size is created in the product pattern design process of CAD1, and then the actual etching is performed in the etching correction process of CAD2. The correction allowance for the side etching, which is excessively removed from the width of the resist pattern in the process, is defined as (A) product dimension C above.
(B) Machining dimension CAD data that is the prototype of the resist pattern is created by adding it to the AD data, and this machining dimension CAD data is drawn by a laser plotter in the next pattern manufacturing process, and the drawn pattern is printed on a glass plate. (C) A glass original plate pattern is created. This original plate pattern is created for both the front and back surfaces of the lead frame.

Then, using the glass original plate as a mask, the resist coated on the metal material such as the copper plate which is the base material of the lead frame is exposed (baked),
By developing and burning (curing) (D) to form a plate-making pattern (resist pattern), etching for removing the metal material in the exposed portion is performed, and then the adhering resist is peeled off. A lead frame, or (E) product pattern is obtained.

In the manufacturing process of the lead frame,
The (E) product pattern is preferably the same as the (A) product dimension CAD data which is the design pattern. Therefore, (B) processing dimension CAD data (this is (C) glass original plate pattern, which is designed by adding a correction allowance to this (A),
The size difference between (D) the pattern having the same size as the plate-making pattern) and (E) above is large, and usually has a difference of several tens of μm.

Similarly, as another etching product to be microfabricated, there is a shadow mask for a color television. In comparison with this, the lead frame has an irregular shape and the post-process performed after the etching is complicated. It has the feature of being

Further, as a feature of the lead frame, there is a gap (space to be removed by etching) between the island 10 to which the chip is attached and the tip of the inner lead to be wire-bonded, and the etching liquid easily enters there. The etching of the tip portion of the inner lead is likely to proceed and the tip tends to be tapered, but a sufficient tip width is required for wire bonding.

As described above, the CAD data (B) for forming the plate-making pattern (D), which serves as a mask for etching a lead frame which is difficult to process, is side-etched in excess of the resist pattern as described above. It is created by performing a correction for adding the size to be added to the product size CAD data of (A) as a correction margin. Conventionally, the correction allowance used for the above-mentioned etching correction has been set based on experience.

Further, it is necessary to measure the dimension of the actually manufactured product, for example, in order to certify that the dimension of the inner lead tip is within the tolerance (allowable range from the target value). In this case, conventionally, local dimension measurement is often performed for some leads, but there is also a demand for all leads.

However, in the method of determining the etching compensation amount based on experience as described above, the design of the processing size pattern of (B) is performed for a new pattern or a fine pattern having a fine pitch which has not been experienced in the past. If required, the correction allowance cannot be set appropriately, so that a defect occurs in the product dimension, and it is likely that it is necessary to correct again and etch again each time. In particular, a lead frame having a difficult fine pattern is subjected to trial and error many times, resulting in a large delay in delivery of the product.

Further, in the past, in general, only local dimension measurement was performed, so that it was easy to overlook a defective portion, but it took too much time to measure all leads (all pins), and as a result, It takes a lot of time and effort to determine the tolerances and certify the products.

As a method for solving the above-mentioned inconvenience,
It is extremely important that at least the design pattern and the product pattern are strictly overlapped and collated, and a raster image of a physical pattern taken from a camera on a CAD device is used as the CAD data as the CAD data which can be used for such an application. There is known a CAD system for displaying on a screen by superimposing on each other.

Therefore, by designating the area in which the measured lead portion exists, the field of view of the camera can be easily moved to that area, and a so-called navigation function can be used to input an image of the lead portion existing therein. A navigation / actual item matching C that has the CAD pattern data and the input image superimposed on the CAD device and is displayed on the screen, and the size of the image can be measured.
AD system becomes effective.

As a CAD system having such a function, CAD data of a design pattern that has already been input on the CAD device is displayed on the screen, and an area is designated on the screen, so that the actual product corresponding to the area is displayed. There is known a CAD system that captures an image with a camera, displays the raster image on CAD data (design pattern) in an overlapping manner, and collates the image.

In this CAD system, FIG.
As shown in the product design dimension CAD data and (B) product pattern, assuming that the CAD data and each pattern of the actual product have the same dimension, P of the rectangular CAD data is used.
The operator inputs three points P1 ', P2', and P3 'of the actual data (product pattern) corresponding to the three points 1, P2, and P3 as reference points, and the CAD data is converted into scale, rotation, and movement. It corrects by multiplying and aligning it so that it may correspond to the actual thing.

[0018]

However, since the actual data is raster data and its magnification cannot be changed, when the CAD data is displayed on the screen by superimposing it on the screen, the CAD data is rasterized as described above. Since they are made to match the size of the image and they cannot be enlarged or reduced at the same rate, it is not possible to change the magnification and see a rough superimposed image or the entire image.
When it is desired to enlarge or reduce the size, there is no choice but to adopt a method in which the lens of the optical microscope used for image capturing is exchanged to mechanically change the capturing magnification and the CAD data is adjusted to the input image.

Since the scale is adjusted at three points as described above, it may be convenient to inspect for the presence or absence of defects, but the difference in size between the two is not known. In addition, if there is a significant dimensional difference between the etching product and the processed dimension pattern, just visually aligning them both will
There is also a problem in that the positional alignment of the both cannot be accurately performed because the positional deviation easily occurs when the position is deviated from the aligned position.

Therefore, based on the CAD data of the product design dimension pattern, a CAD device having a function of creating CAD data of the processing dimension pattern which is the prototype of the resist pattern, a camera for inputting the image of the actual pattern with high accuracy,
CA equipped with a raster / vector conversion means for converting input image data into CAD data and having a function of collating physical objects having a function of superposing and collating two or more CAD data.
D system is constructed, a pattern of an actual object such as a lead frame is photographed by a camera in view unit, the input image data is converted into vector data, and the vector data is hit with a predetermined pitch sent in the X direction or the Y direction. The process of adding the offset and synthesizing with the vector data of the previously captured image is executed for the entire captured area to create CAD data corresponding to the entire physical pattern, and the CAD data corresponding to the physical pattern and the design pattern. It is conceivable to superimpose the corresponding CAD data on the CAD device and move at least one of the patterns in the X direction or the Y direction while observing the screen to align the two patterns with each other.

According to this CAD system, the design pattern which is the original CAD data on the CAD device and the pattern of the actual CAD data created by raster-vector conversion are easily and accurately exchanged while observing the monitor screen. It is excellent in that it can be aligned with.

In general, in order to capture a specific local image of a minute pattern, for example, in the case of a lead frame, it is easier to operate a wide area such as one chip. In the CAD system described above, since the actual image captured on the monitor screen through the optical microscope at a constant magnification, for example, in a narrow visual field range of about 0.5 mm square, a target capturing area is searched for. Another problem is that it is difficult to do.

The present invention has been made to solve the above-mentioned problems, and it is possible to accurately specify one or two or more areas to be photographed as image data for an actual pattern of an etching product or the like, and to specify it in another area. C can be locally overlaid on top of CAD data, and can be freely scaled up or down when designating the capture area or when comparing and collating the captured physical data with other data.
An object is to provide an AD system.

[0024]

According to the present invention, in a CAD system, a CAD device having a function of creating CAD data of a machining dimension pattern which is a prototype of a register pattern based on CAD data of a product design dimension pattern, It is equipped with an image input means for inputting the image of the actual pattern used or generated in the etching process with high accuracy, and a raster vector conversion means for converting the input image data into CAD data, and at least two CAD data are stored. An actual collation CAD system having a function of superposing and collating, and a function of displaying reference CAD data on a monitor screen in which a reference point relating to an arbitrary pattern used or generated in an etching step is displayed, and the reference CAD data. The function to calculate the reference point of the actual pattern corresponding to the reference point of the The function of designating a predetermined area on the reference CAD data and designating the capture area of the actual pattern corresponding to the reference area, and the field of view of the image input means in the capture area designated by referring to both reference points. The matching navigation function, the function of inputting the image pattern of the actual pattern of the photographing area where the visual fields are matched by the navigation function, and the raster image conversion of the raster image data of the input visual field unit to the CAD data corresponding to the actual pattern A function of displaying the CAD data in a designated area of the reference CAD data on the monitor screen in an overlapping manner,
The above problem is solved by adopting a configuration having

According to the present invention, in the above CAD system, a function of enlarging and displaying the reference CAD data on the monitor screen is provided so that an area can be designated on the enlarging screen.

According to the present invention, in the above CAD system, the navigation for matching the field of view of the image input means with the photographing area of the actual pattern is performed on the reference CAD data displayed on the monitor screen with each reference point as the origin. The coordinate value defining the photographing area is determined and executed based on the coordinate value defining the designated area.

According to the present invention, in the above CAD system, the navigation for matching the visual field of the image input means with the photographing area of the actual pattern is mounted with a sample mounting portion for fixing the visual field of the image input means and setting the actual article. The XY stage provided is driven and controlled to be executed.

According to the present invention, in the above CAD system, as the reference CAD data, the CAD data corresponding to the actual product input in advance is used.

[0029]

In the present invention, the CAD corresponding to the actual product, which is created by inputting the CAD data from the original such as the product design dimension and the actual product such as the lead frame later and raster-vector converting it.
For a CAD system capable of overlapping and collating data in any combination, when newly inputting an image of the actual pattern, the reference CAD data with a clear reference point already input on the CAD device is obtained. Display on the monitor screen,
Since a navigation function that uses it as a guide is added, on that data (design pattern displayed on the screen),
For example, by specifying an arbitrary rectangular area,
Based on a separately calculated reference point of the physical pattern, a photographing area corresponding to the area can be designated on the physical pattern, and an image of the actual object is input from the photographing area in units of fields of view. After being fed back to the CAD data by raster vector conversion, the data can be superimposed on the corresponding designated area on the reference CAD data and displayed on the screen.

In this way, the CAD device and the image input of the actual pattern are linked, the navigation for designating the photographing area from the CAD device, and the photographed image data are fed back to the CAD device to be converted into CAD data. Since it can be superimposed and displayed in the designated area on the corresponding reference CAD data, it is possible to accurately designate one or more areas to be photographed as image data for etching products, etc. Local overlapping display is possible.

Further, in the present invention, the reference C is displayed on the monitor screen.
When it is possible to specify the area on the magnified screen with the function of magnifying and displaying the AD data, the reference CAD data can be magnified or reduced freely on the device, so the capture area can be specified on the data. When designating, it is also possible to display a reduced image on the monitor, grasp the whole, then designate a part of it to be enlarged and display it, and to designate an area on the enlarged pattern. Further, after the image data input from the shooting area is converted into CAD data, the scaling can be performed in the same manner, so that both patterns that are locally overlapped and displayed can be enlarged and displayed. It becomes possible to easily compare and collate.

In the present invention, the navigation for matching the field of view of the image input means with the photographing area of the actual pattern has coordinates that define the designated area on the reference CAD data displayed on the monitor screen with the reference point as the origin. Based on the value, if the coordinate value that defines the shooting area is determined and executed,
Exactly 1: the area specified on the reference CAD data on the CAD device and the shooting area on the actual pattern.
Since it can correspond to 1, high-precision navigation is possible.

In the present invention, the navigation is
When the field of view of the image input means is fixed and the XY stage on which the sample mounting unit for setting the actual product is mounted is drive-controlled to be executed, between the visual field, the XY stage and the actual product. By performing the orthogonal adjustment of the XY stage accurately, the XY stage
Since the actual object can be matched with the target position simply by moving in two directions of Y, it is possible to perform highly accurate navigation with a simple mechanism.

In the present invention, when the CAD data corresponding to the actual product which is input in advance is used as the reference CAD data, even if there is no CAD data at the time of product design or CAD data of the processing dimension pattern which is the prototype of the resist pattern. If the original pattern and the plate-making pattern are the actual patterns, the final product pattern can be compared and collated, so that the processing accuracy of the manufacturing line can be made more clear.

[0035]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing a schematic configuration of a CAD system of an embodiment according to the present invention.

The CAD system is a sample (actual product).
A sample mounting device 30 for mounting a sample, an optical microscope 32 for enlarging a sample set in the mounting device 30, a CCD camera 34 for receiving an image observed by the microscope 32 and converting it into a color video signal, and the CCD An image processing device 36 for processing a color video signal from the camera 34,
A TV monitor 38 capable of color-displaying image data processed by the image processing device 36, and a raster / vector conversion function for generating CAD data from image data input from the image processing device 36 in addition to a normal drawing function. Or 2
An engineering workstation (EW) that constitutes a CAD device having the functions of superposing the above CAD data, mutual positional movement (shift) between them, and dimension measurement.
S) 40.

Further, in the above CAD system, the sample mounting device 30 includes a manual rotary stage 42 having a sample mounting portion (not shown), an XY stage 44 for moving the sample in the plane direction, and a sample in the vertical direction. The XY stage 44 and the Z stage 46 are configured to move, and the XY stage 44 and the Z stage 46 operate by receiving a command from the workstation 40 via the interface RS232C.
The Y stage controller 48 and the auto focus controller 50 are driven and controlled respectively. Further, a laser position detector is attached to the XY stage 44, and the position measurement in the XY directions is performed by a laser scale counter 52 which is also operated by a command from the workstation 40, and the measured value is fed back to the workstation 40. Then, the position measurement value of the XY stage 44 is corrected by the XY stage controller 48.

Further, the autofocus controller 5 described above
An image signal used for autofocus is directly input to CCD 0 from the CCD camera 34, and an autofocus monitor (not shown) separately provided with an image captured through the microscope 32. It is possible to directly view the image on the TV monitor 38 from the autofocus controller 50 by using the monochrome (B /
The video signal of W) is input.

FIG. 2 shows the mounting device 30 and the optical microscope 3.
2 is a perspective view showing the appearance of the CCD camera 34 and the CCD camera 34,
The XY stage 44 shown in FIG.
An X drive motor 54 which is composed of an A stage and a Y stage 44B and is connected to the stage controller 48.
The A and Y drive motors 54B are movable in the X and Y directions, and the rotary stage 42 for mounting the sample is mounted on the Y stage 44B so that it can be manually rotated.

In addition, the X stage 44A and the Y stage 44
Scale patterns 56A and 56B each made up of a fine diffraction grating are attached to the side surface of B, and laser light is used to scale the positions of both stages 44A and 44B moved by the X drive motor 54A and Y drive motor 54B. , 56B are provided with an X position detector 58A and a Y position detector 58B for irradiating and detecting the laser scale counter 5B.
Connected to 2.

The Z stage 46 is arranged below the X stage 44A, and the Z stage 46 can be moved back and forth in the vertical direction by a Z drive motor 54C. It is connected to the auto focus controller 50, and the distance between the objective lens 32A of the optical microscope 32 and the sample is increased or decreased based on a control signal from the controller 50 to perform auto focus on the microscope 32. There is.

A transmission light source unit 60 which also serves as a support is disposed below the Z stage 46.
0 has a built-in transmissive light source (not shown) that projects light from below onto the microscope 32, and a transmissive light source switch 60A and a light amount adjusting volume 60B are attached to its side wall.

Further, an epi-illumination light source unit 62 is attached to the microscope 32, an epi-illumination light source (not shown) is built in the unit 62, and an epi-illumination light source switch 62A and a light quantity adjusting volume 62B are provided on a side wall of the unit 62. And are attached.

Therefore, at the time of capturing the microscope image of the sample with the CCD camera 34, it is possible to use at least one of the light source of transmission and epi-illumination.

Next, the image processing device 36 will be described with reference to FIG.
The features of the configuration and the processing function will be described. The processing device 36 has an image input / processing / binarization processing function, for example, S manufactured by Seiko Denshi Kogyo Co., Ltd.
V-2110 (trade name) can be used.

The image processing device 36 is the CCD camera 3
Each of the R (red), G (green), and B (blue) signals input from 4 can be stored for each screen, and 3 for R image, G image, and B image each surrounded by a rectangle are stored. Monochrome memory for storing one frame memory and Y (luminance) signal
One frame memory for W image and H obtained by processing the R, G, B signals by a 3 × 3 matrix operation unit
(Hue), S (saturation), and V (luminance) image data are stored in the three frame memories for each image of H, S, and V, and the R signal and B signal are processed by the image arithmetic operation unit. A total of eight frame memories of the RB difference image frame memory that stores the difference image data of both obtained as described above are provided.

The reason for adopting different color signals in this way is as shown in the table of FIG.
Depending on the material used and the type of image required, the type of light source suitable for use and the optimum color signal may differ.

That is, there are two types of original patterns, one for the front and the other for the lead frame, both of which are glass dry plates (the pattern is formed of an opaque film on the glass plate), so that a black and white transmission image is obtained. The frame memory of the B / W image is the optimum plane because it can be obtained with good contrast.

Since the plate making pattern is a resist pattern formed on the front and back surfaces of the lead frame,
It depends on the type of metal material and the type of resist, and it is necessary to use a reflected light source to receive the reflected image.

When casein is used as the resist, since the resist has a reddish color at the stage of heat-curing after development, the 42-alloy material of silver-white is used as an optimum plane for the B image frame. Although a memory can be used, the copper (Cu) material itself has a reddish color, and the difference is not clear in the B image. Therefore, the frame memory of the V image is the optimum plane.

When a blue dry film is used as the resist, the R image is optimal for 42 alloy, but the frame memory for the RB difference image is optimal plane for copper material.

In the case of the product pattern after the etching is completed and the resist film is removed, the penetrating transmission image and the reflection images on both the front and back surfaces can be received, and the transmission image is black and white B as described above. / W when the image is a reflection image, H
(Hue) The image becomes the optimum plane.

Further, among the product patterns, when the fixing tape 22 (referred to as TP in the table) made of polyimide resin is attached to the inner lead as shown in FIG. 22, the tape is red. Since the transparency is high in the system, in order to obtain a completely transparent image where the image is not input on the tape, B
The / W image becomes the optimum plane. However, it is necessary to appropriately set a threshold value for binarization described later.

On the other hand, in order to capture a transmission image including a tape, blue which is opaque to the tape is suitable, so that the B image becomes an optimum plane.

Further, when only the tape portion is desired to be photographed, the H image becomes the optimum plane for the reflection image using the epi-illumination light source.

As described above, when the optimum plane to be used is selected according to the object to be captured as an image, the corresponding image signal is input to the binarization processing section from the eight frame memories. Binarization processing is performed on the image data input by the binarization processing unit. The threshold value set at that time can be arbitrarily set from the gradation values of 0 to 255, for example.

Morphology processing for removing black spots or white spots on the image caused by fine roughness of the surface of the actual pattern, etc. on the image data binarized by the binarization processing section. I do. However, in the case of a transmission image, such a spot does not occur, so that it is not necessary to perform it.

Whether the spot to be removed is white or black is set, a predetermined number of morphology is set, and the image is expanded / contracted the number of times to remove the spot.

Next, the binary image obtained by performing the above processing is the workstation 4 functioning as a CAD device.
0, where the binary image is processed by the raster / vector conversion unit and converted into CAD data. As the workstation 40, normal CAD software and actual matching CAD software (for example, CAD manufactured by Computer Vision Co., Ltd.)
It is possible to use, for example, Sparc Station 10 (trade name) of Sun Microsystems, which is activated by software Medusa (trade name).

The raster / vector conversion section converts a general outline of CAD data and a method of converting white or black area image data into trapezoidal area CAD data, although detailed description thereof is omitted. There is. When the signal conversion processing is performed by this raster / vector conversion unit, the RV vertex thinning coefficient for determining the accuracy of linear approximation is set. The smaller this coefficient is, the less jagged the line is in the case of the outline, and the finer the trapezoid can be extracted in the case of the trapezoid area.

When either one of the above two conversion methods is selected and the trapezoidal area conversion method is selected,
It is necessary to select either white or black and determine the target area for trapezoidal area processing.

Further, the CAD system of the present embodiment has a navigation / actual item collating function, and the workstation (CAD device) 40 captures the actual pattern by software incorporated in the CAD software. It is possible to perform navigation for designating an area on a CAD device and local superposition after converting captured image data into CAD data.

That is, in the CAD system of the present embodiment, when the target physical pattern is the lead frame, the reference point (origin) is clear, and for example, the product design pattern is displayed on the screen of the monitor 38 as the reference CAD data. While displaying, the reference point of the reference CAD data (for example,
It has a function of calculating a reference point (for example, an island center point) of an actual lead frame corresponding to an island center design origin described later). This specific function will be described in detail later.

Further, in this CAD system, on the standard CAD data displayed on the screen, for example, four desired points are specified by a cursor, and a rectangular area is designated.
A corresponding capture area on the lead frame can be designated, and a navigation function for matching the visual fields of the CCD cameras 34 with reference to the reference points is provided in the area. The lead frame of the matched area is input as an image, and the input raster image data for each field of view is input to the workstation 40.
It has a function of converting the CAD data into CAD data corresponding to the actual pattern by performing a raster / vector conversion by feeding back to the CAD data, and superimposing the CAD data on the designated area of the reference CAD data.

In the CAD system, the reference CAD data is enlarged and displayed on the screen of the monitor 38, and the area can be designated on the screen. Also, the CCD camera 34
The navigation for matching the field of view of the image with the capture area of the lead frame is based on the coordinate values that define the designated area on the reference CAD data displayed on the screen of the monitor 38 with the reference point as the origin. The coordinate values that define the area are determined and executed.

Further, in the navigation, the XY stage 44, on which the field of view of the CCD camera 34 is fixed and the sample mounting portion for setting the lead frame is mounted, is operated in response to a command from the workstation 40.
The drive is controlled by the stage controller 48 so that the shooting area of the lead frame is matched with the field of view of the camera 34.

The reference point CAD data is not limited to the product design pattern, and may be the CAD data of the processing dimension or the pattern of the original plate or the plate making. Any one may be used as long as it is converted into data.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG.

First, before starting a specific operation, basic setting and adjustment of system functions are performed. In particular, when the lens of the microscope 32 or the camera 34 is replaced, it is necessary to perform orthogonal adjustment of the camera 34 and the XY stage 44. This is done by manually rotating the camera mount. In this orthogonal adjustment, as shown in the monitor screen in FIG. 6, a small mark (may be a small dust) indicated by an X mark on the sample mounting portion is used as a reference point, and this range does not deviate from the monitor screen. If the reference point does not deviate from the reference line (horizontal line) on the monitor when it is horizontally moved in the left and right X directions, it can be performed by setting OK.

Further, in order to provide an image measuring function, it is necessary to measure the size per pixel and the screen feed pitch. This is one screen size (512 × 4 in this embodiment).
In measuring the stage feed value corresponding to 80 pixels), specifically, as shown in FIG. 7 showing the screen of the monitor 38, the reference point indicated by an X mark is set to the X direction and the Y direction on the screen. In both cases, the laser scale counter 52 is moved to four points on the reference line at the positions of 1/4 and 3/4, and the stage movement distances in the X and Y directions at that time are calculated.
It is possible to measure with high accuracy by using the count value according to. In this case, the size per pixel is Xs / 2
56, Ys / 240, and the screen feed pitches in the X and Y directions are calculated as 2Xa and 2Ys. For the measurement of the above dimensions and pitch, the feeding pitch by the XY stage drive motor (step motor), for example, 1 μm may be used without using the laser scale counter.

On the premise that the above preparatory operation is completed, the sample is set in step S1. Specifically, as shown in FIG.
The sample (lead frame) is attached to a predetermined position of the sample, and the operator operates the rotary stage 42 while viewing the image of the sample taken from the camera 34 displayed on the monitor 38 to adjust the sample orthogonally. To do.

If the monitor screen displaying the horizontal edge of the sample input by the CCD camera 34 whose orthogonal adjustment with the XY stage 44 has already been completed is as shown in FIG. When the rotary stage 42 is manually rotated to a position where the above-mentioned edge does not deviate from the horizontal reference line even when largely moved in the X-axis direction,
The orthogonal adjustment between the sample and the XY stage 44 is performed.

Then, in step S2, the light source to be used is selected and the light amount thereof is adjusted. That is, the switch 60A or 6
A transmission light source or an epi-illumination light source is selected by turning on any of 2A. The desired light source is selected, and the light amount is adjusted by the light amount volume of 60B or 62B so that the brightness signal falls within the specified range by looking at the monitor of the autofocus device. In some cases, both light sources can be used at the same time.

In the next steps S3 to S6, the menu is displayed on the menu screen displayed on the monitor screen (each can be displayed on the same screen as a window) as schematically shown in FIGS. 9 to 11, for example. It is executed by selecting.

First, in step S3, the center of the island (die pad) captured as an image is designated (origin calculation) using the origin calculation function, which is a feature of the present invention.

In this embodiment, the island 10 is shown in FIG.
Enlarge and show the monitor screen on the right side
At the point P at the upper end of the island 10._T, And the bottom point P
_BTo match the Y-axis center of the camera input screen respectively.
By inputting each Y coordinate value Y_T, Y_B
Is calculated and the point P at the left end is calculated._LAnd the point P on the right end_RThe it
By inputting it so that it matches the center of the screen in the X direction.
X coordinate value X _L, X_RSo that
ing. Therefore, these four areas are black and white (black areas are diagonal
From the coordinate value of the edge position corresponding to the boundary (indicated by the line),
The coordinates (X, Y) of the island center, which is the alignment origin,
It is calculated by the following formula.

X = (X _R + X _L ) / 2, Y = (Y _T + Y _B ) / 2

Since the CAD system of this embodiment has an edge detection function and is capable of automatically recognizing edges, the edges of the black and white boundaries on the left, right, top, and bottom are determined as described above, and the X coordinate and Y Even if it does not match the center of the coordinates, simply capture each edge part in the screen, the coordinate value of each edge is detected, the calculation is automatically executed by the above formula,
Similar center designations can be made. By specifying the center of the island of the input image in this way, the center of the island of the design pattern of the CAD data can be aligned with the center of the island, so that the overlay display can be accurately performed.

Normally, the lead frame for one chip is basically symmetrically designed with the center of the island as the origin, so the CAD data is described (designed) with the center of the island as the origin, or Since the coordinates are clearly shown in the data, by making the origin calculated by the above-mentioned method coincide with the center of the island of the CAD data on the CAD device, the dimensional difference is large, for example, the processing size pattern and the etching pattern, It becomes possible to perform accurate alignment automatically.

In the next step S4, the sampled area of the sample is designated.

In the case of photographing the lead frame for one chip, for example, shown in FIG. 22, the lead frame input from the camera 34 and displayed on the monitor screen while the XY stage 44 is moved is displayed. The shooting area can be designated by sequentially moving the left, right, upper, and lower ends into the screen and designating respective points (four endpoints defining the rectangular area) with the cursor, for example. At this time, a plurality of areas including a partial area (for example, an inner lead bonding area) can be designated by the same method for navigation described later.

When CAD data of the product design dimension is input, the dimension is read from the CAD data and the coordinates of the four end points can be automatically set, for example, by using the dimension value so that the photographing area can be set. Can also be specified. In this case, the area can be designated in a short time, and the CAD pattern design pattern to be executed later can be easily aligned with the actual pattern input as the image.

Information regarding the center of the island and the shooting area on the image designated in steps S3 and S4 is stored in the setting file XY.

Then, in step S5, conditions for autofocus (AF) are set. Here, the mode is selected and the limit value is set. In this mode, one reference point (position) is determined in the Z-axis direction applied to a flat sample, and the 2WAY method in which the Z stage 46 is finely moved vertically to focus on the reference point, and a surface with large unevenness is used. Z stage 4 up to a predetermined lower position beyond the focal point to be applied
From the state where 6 is lowered, the stage 46 is gradually raised to bring the sample closer to the lens and focus 1 WAY
There is a method and a selection of a lens to be used from objective lenses (five types in this embodiment).

The limit is an approach limit distance set to prevent a collision between the lens and the sample during autofocus. In addition, here, 1 WAY is used for the product sample with severe unevenness as the mode, and 2 W when it is not.
Select AY, use a 20x objective lens as a lens to capture with a resolution of 1 μm / 1 pixel, and use a focus parameter setting file for that. 2 mm from the origin as the limit value, the maximum value of the focus working distance is 1 limit. Set a normal default value such as "/ 2". The conditions set in this step are stored in the setting file AF.

When the 2WAY method is selected as the AF mode, the edge of the sample (flat portion) is brought into the screen and the auto focus is activated or the Z stage 46 is manually moved to determine the focus origin. (Z coordinate value of the reference point) is also set. The autofocus is executed by moving the Z stage 46 up and down slightly with reference to this position as described above.

In the next step S6, conditions for image processing are set. The contents of the selection are the selection of the input plane to be used from the eight types of image frame memories shown in FIG. 3 that use different colors, the setting of the binarization threshold value when creating a binary image, white or black. Condition and raster vector (RV) to remove unnecessary points of image from image data
It is a conversion condition. The conditions set in this step are stored in the setting file SV.

After storing the conditions in each setting file by the above operation, the raster / vector conversion method (outline (contour) mode or trapezoidal area mode) is selected.

The batch processing of step S7 for selecting the contour mode and step S8 for selecting the trapezoidal mode is automatically executed in the workstation 40, and the raster data of the entire image-captured photographing area is converted into vector data. CAD data created by the output file LFX
The data is converted into various CAD system formats in step S9, and various collation processes are performed. This collation (overlapping) process is performed by selecting a menu on the screen of the workstation.

Next, the CAD device (workstation 4
The batch processing of steps S7 and S8 executed inside 0) will be described with reference to the flowchart of FIG.

First, in step S11, the data etc. stored by the above operation are read from the above-mentioned setting files XY, AF, SV, etc., and the cell division of the photographing area is calculated.

The contents of each setting file read here are exemplified below.

File XY-Position of four sides of island (center of island) -Number of designated input area-Coordinate value of each rectangular area File SV-Input color plane number-Binarization threshold value-Morphology direction and number of times (+: white to black) ,-: Black to white) -RV thinning coefficient file AF (normally fixed) -cell unit execution or fixed focus selection-AF mode (2 modes for each of 5 lens types (1 or 2W)
AY))-Soft limit values (upper and lower limits of Z stage) Lens file (fixed) -Field size by lens-Actual size of 512 x 480 pixels (including non-rectangular distortion)

The morphology is based on the contents of the file SV.
In the direction +, the black point is removed from the white image, and-is the white point removed from the black image. Also, in the contents of the file AF, "execute in cell unit" is applied to a sample having minute unevenness such as a lead frame by executing autofocus every time an image is captured, and fixed focus is applied to a glass original plate. Applies to those with high flatness. The soft limit value is the same as the limit value set in step 5, and is the upper limit value of the Z stage movement set by the operator to prevent the sample from colliding with the lens, or the lower limit value to prevent it from lowering more than necessary. is there.

In the lens file, the field size of each of the above five types of objective lenses, the actual size corresponding to all the pixels of the CCD camera 34 used in this embodiment (the distortion caused by the lens is corrected). 4 dimensions) and are stored.

Similarly, the calculation of the cell division executed in step S11 can be performed, for example, when the lead frame for one chip is 4
0 mm x 40 mm, 512 x CCD camera 34
When it is assumed that the visual field size of 480 pixels is 496 μm × 464 μm, it means that the lead frame is divided into 80 × 86 units (cells), as shown in FIG. It is an input unit when sequentially moving in the Y direction to input an image of the entire lead frame, and also a feed pitch (offset amount) when feeding to the next cell. However, in practice, the offset amount is usually set to about 90% of the cell size in order to make the boundary of each captured image clear.

After the calculation of the number of cell divisions in step S11 is completed, in step S12, the XY stage controller 48 moves the XY stage 44 in response to a command from the workstation to bring the field of view of the optical microscope 32 to the first photographing position. Set. At that time, the actually measured position (corresponding to the X and Y coordinate values) actually measured by the laser scale counter 52 is fed back to the workstation 40.

Then, in step S13, autofocus is executed by the autofocus controller 50 based on the command from the workstation 40 at the camera setting position, and the controller 50 reads the Z coordinate value of the in-focus position. Workstation 4
Send to 0.

Then, in step S14, an instruction is issued from the workstation 40 to the image processing device 36 (SV), the image processing device 36 is activated, and an image frame is input from the CCD camera 34 to the processing device 36. , A binarized image is generated by performing binarization on the input raster image and morphological processing for removing unnecessary points from the image.

Next, in step S15, raster / vector conversion is executed. First, the binary image data generated in step S14 is read from the image processing device 36 into the workstation 40, converted into vector data by the RV conversion section, and transmitted to the image processing device 36 again. , While displaying it on the TV monitor 38, converting the vector data into CAD data and storing it in a file, at the same time calculating the offset amount and scaling once sent from the XY stage and moving to the next cell, Returning to step S12, the process up to step S15 is executed for the cell, and this process is repeated.

As shown by the broken line in FIG. 13, when the step S14 is completed, a command for moving to the next cell is issued to the XY stage controller 48 and the autofocus controller 50 to prepare for the preparation. By doing so, the RV conversion process, the XY stage movement, and the autofocus process can be performed in parallel.

The above image capturing is performed, for example, in FIG.
By executing the above for all areas, the entire lead frame for one chip can be displayed on the monitor 38 as vector data, and the CAD data of the lead frame can be generated.

When the CAD data thus created is converted into various CAD system formats as shown in step S9 of the flow chart of FIG. 5,
The product design dimension data that is originally input as CAD data on the screen of the monitor 38 and the processing dimension data in which the correction allowance is added are displayed as a graphic pattern, and these data are converted from the image input data to CA in this embodiment.
The product pattern of the lead frame converted into the D data can be displayed in an overlapping manner.

FIG. 15 shows an example of collation on the screen of one lead frame. The line drawing A on the outer side is a processing dimension pattern, and the inner line B is a product design pattern before being corrected to A. C is the actual product pattern (inner lead) obtained by actual etching. This product pattern is a through image using a frame memory for B / W images. From this FIG. 15, it can be seen that the setting of the correction margin is almost appropriate.

FIG. 16 also shows a screen display near the tip of the inner lead. The outer line drawing D is an image in which the front side reflection image is overlapped with the back side reflection image, and the inside E is an image in which the back side reflection image is overlapped. Is an example of collation, and is displayed in different colors.

From this figure, it is possible to clearly understand the difference in etching degree between the front side and the back side, which cannot be recognized from the transmission image. The lead frame is usually etched by spraying an etching solution from both upper and lower sides with the surface on which the chip is mounted facing down. The reason for making the surface side down is that it is necessary to secure a sufficient width for wire bonding on the surface of the inner lead tip portion, but etching is easier to proceed on the upper surface. From this FIG.
It can be clearly understood that there are etching differences between the front and back.

The basic features and performance of the CAD system of this embodiment described in detail above can be summarized as follows.

Since full-color image input processing is possible, it becomes possible to collate the resist pattern and the pattern for the front and back of the product with each other or with the design pattern or the like, so that dimension comparison and measurement are possible. It is possible to objectively evaluate etching. Since it has its own automatic positioning function, the center of the island can be calculated automatically. It functions as an interface to various commercially available CAD systems such as Medusa (trade name) manufactured by Computer Vision.

As the measurement performance, the resolution is 1 μm,
Measurement accuracy: 1μm guaranteed, visual field size: 496 × 464μm
(512 × 480 pixels), measurement size: 200 mm square (expandable), measurement target: product (transmission image, reflection image by front and back),
Plate making (resist reflection image) and glass original plate (transmission image) can be mentioned.

Therefore, the CAD system of this embodiment is used for automatic calculation of etching compensation, dimensional control for each manufacturing process, quality control such as product dimensional inspection, etching simulator, etc., for providing data to research and development. Available.

The CAD system of this embodiment can perform the following operations by the navigation / actual item collating function described above, in addition to the basic operation described in detail above.

FIG. 17 is a monitor screen showing CAD data of product design dimensions as reference CAD data. Here, one chip in a continuous state in which lead frames for a plurality of chips are continuous in the left-right direction is shown. The entire state of the image is displayed in a reduced size including its vicinity. As described above, this reference CAD data is created with the center of the island as the origin.

Next, the operator uses the origin calculation function described with reference to FIG. 12 to set the actual lead frame actually set in the sample mounting apparatus 30 and the orthogonal adjustment of which has been completed for the island 10. The center coordinate value is calculated and the origin coordinate is determined.

While the operator sees the entire lead frame on the monitor screen of FIG.
When area A is specified from the console 0, the screen shown in Fig. 18 appears.
Area A is enlarged and displayed as shown in FIG. Then, while looking at this enlarged screen, when the area B including the circular jig hole is designated as the area for actually inputting an image from the actual lead frame, the XY is read from the workstation 40.
A command is sent to the stage controller 48 to move the XY stage 44 by the distance from the origin to the designated area,
The field of view of the camera 34 is made to coincide with the shooting area of the lead frame corresponding to the above B, and an image is input from the area. The moving distances in the X and Y directions at that time are measured by the laser scale counter 52.

The input image data is fed back to the workstation 40 and converted into vector data, and the distances in the X and Y directions from the origin are added as an offset to the data to obtain CAD data. Display on the monitor screen. The state is shown in FIG.
The shaded portion corresponds to the actual pattern of the lead frame formed by etching.

In this way, in order to display the actual image data after converting it into CAD data in the corresponding area of the reference CAD data on the screen, the same magnification as that of the reference CAD data is set, and as shown in FIG. It is possible to superimpose and display, and it is also possible to freely change the magnification in the superposed state if necessary.

Similarly, when the area C is designated in FIG. 17, the inner lead of the lead frame on the reference CAD data is enlarged and displayed, as shown in FIG. As a result, an image near the tip of the inner lead of the lead frame corresponding to the area D is captured, and it is possible to accurately display the images in an overlapping manner as shown in FIG.

The above-mentioned two data can be superimposed by being displayed from the original and displayed in a layer below the reference CAD data, and at that time, the colors of both should be changed to facilitate visual comparison. You can also

As described above in detail, according to the present embodiment, the reference CAD data (design dimension pattern) already input as CAD data and the origin of both the actual lead frame are accurately matched to each other. By using the CAD data as a map, it is possible to perform navigation for capturing an image of the actual product, and it is possible to overlay the local pattern of the actual product with the CAD data at a corresponding position on the reference CAD data each time.

In the same collating process, the whole lead frame is photographed and converted into CAD data by the above-described method, and then the collation can be performed while observing a desired area on the CAD device. Although it may take several hours to capture the image, and even the unnecessary portion may be captured, according to the present embodiment, it is possible to accurately specify the area to be captured, and to specify multiple points. Work efficiency can be significantly improved.

Further, since the enlargement / reduction can be freely performed at the time of designating the photographing area and at the time of comparing and collating the photographed data,
It is easy to visually confirm on the screen or on the hard copy, and the effect of visually publicizing the finishing accuracy to the requester is great.

As described above in detail, according to this embodiment, C
By linking the AD device with the image input of the actual pattern such as the lead frame, the navigation for designating the shooting area from the CAD device and the CAD for the captured image data
The data is fed back to the device and converted into CAD data, which can be overlaid and displayed on the designated area on the corresponding reference CAD data. Therefore, one or more areas to be captured as image data of the lead frame etc. It is possible to specify with high precision, and local overlay display on the reference CAD data becomes possible.

Further, according to this embodiment, when the photographing area is designated on the reference CAD data on the monitor screen,
It is also possible to reduce the display on the monitor, grasp the whole, and then specify a part of it to enlarge and specify the area on the enlarged pattern.

Further, according to the CAD system of the present embodiment, the etching correction allowance can be quantified by objective data, so that the replacement of the correction allowance due to trial and error can be reduced, and as a result, Delivery time can be shortened.

Further, since it is possible to collectively and automatically perform the tolerance determination, it is possible to greatly reduce the labor of the authentication, and to avoid oversight.
The accuracy can be improved.

Further, since the CAD pattern, the original pattern, the plate-making pattern, and the product pattern can be compared with each other, the accuracy of the manufacturing line can be grasped and the quality can be maintained for each process.

The present invention has been specifically described above, but the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the spirit of the invention.

For example, the reference CAD data is not limited to the original CAD data corresponding to the design pattern, but the CAD corresponding to the actual pattern obtained by once inputting and converting the entire physical image.
It may be data.

[0130]

According to the invention of claim 1, it is possible to accurately specify one or more areas to be photographed as image data for an actual pattern of an etching product or the like, and to superimpose it on other CAD data. A navigation / actual item matching CA that allows local superimposition and can be freely enlarged or reduced when specifying the shooting area or when comparing and matching the captured actual data with other data.
A D system can be provided.

According to the second aspect of the present invention, the reference CAD data can be freely scaled up and down on the device. Therefore, when the shooting area is designated on the data, it is displayed in a reduced size on the monitor to grasp the whole. , You can specify a part of it to enlarge it and specify the area on the enlargement pattern.
Further, after the image data input from the shooting area is converted into CAD data, the scaling can be performed in the same manner, so that both patterns that are locally overlapped and displayed can be enlarged and displayed. It becomes possible to easily compare and collate.

According to the third aspect of the present invention, the area designated on the reference CAD data on the CAD device and the photographing area on the actual pattern can be made to correspond to each other exactly 1: 1. It enables accurate navigation.

According to the fourth aspect of the present invention, the XY stage is moved to the XY stage without performing the rotating operation by accurately performing the orthogonal adjustment between the visual field, the XY stage and the actual object.
Since the actual position can be matched with the target position simply by moving in two directions, it is possible to perform highly accurate navigation with a simple mechanism.

According to the invention of claim 5, C at the time of product design
Even if there is no AD data or CAD data of the processing dimension pattern that is the prototype of the resist pattern, if there is the original pattern and the actual pattern of the plate-making pattern, it is possible to compare and collate with the final product pattern. The accuracy can be made clearer.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a CAD system according to an embodiment of the present invention.

FIG. 2 is a CAD system sample mounting device, a microscope,
Oblique view showing a CCD camera

FIG. 3 is a block diagram showing a frame memory and a processing function of the image processing device of the CAD system.

FIG. 4 is a diagram showing an optimum input plane for each sample.

FIG. 5 is a flowchart showing the operation of the embodiment.

FIG. 6 is an explanatory diagram showing a monitor screen when the camera and the XY stage are orthogonally adjusted.

FIG. 7 is an explanatory diagram showing a monitor screen when the dimensions per pixel and the screen feed pitch are calculated.

FIG. 8 is an explanatory diagram showing a monitor screen when a sample and an XY stage are orthogonally adjusted.

FIG. 9 is an explanatory diagram illustrating a CAD system menu screen.

FIG. 10 is another explanatory diagram illustrating the menu screen of the CAD system.

FIG. 11 is still another explanatory diagram illustrating the menu screen of the CAD system.

FIG. 12 is an explanatory diagram showing an example of a method of designating the center of an island.

FIG. 13 is a flowchart showing a procedure of batch processing executed inside the CAD device.

FIG. 14 is an explanatory diagram showing a cell division calculation method.

FIG. 15 is an explanatory diagram showing an example of a screen in which a plurality of patterns are displayed in an overlapping manner.

FIG. 16 is an explanatory diagram showing another example of a screen in which a plurality of patterns are displayed in an overlapping manner.

FIG. 17 is an explanatory diagram showing a monitor screen in which a lead frame is reduced and displayed.

FIG. 18 is an explanatory diagram showing a monitor screen in which area A is enlarged and displayed.

FIG. 19 is an explanatory diagram showing a monitor screen in which area B is enlarged and displayed.

FIG. 20 is an explanatory diagram showing a monitor screen in which area C is enlarged and displayed.

FIG. 21 is an explanatory diagram showing a monitor screen in which area D is enlarged and displayed.

FIG. 22 is a plan view showing an example of a lead frame.

FIG. 23 is an explanatory view conceptually showing the manufacturing process of the lead frame.

FIG. 24 is an explanatory diagram showing a method of aligning CAD data with an actual pattern.

[Explanation of symbols]

 30 ... Sample mounting device 32 ... Optical microscope 34 ... CCD camera 36 ... Image processing device 38 ... TV monitor 40 ... Workstation (EWS) 42 ... Rotation stage 44 ... XY stage 44A ... X stage 44B ... Y stage 46 ... Z stage 48 ... XY stage controller 50 ... Auto focus controller 52 ... Laser scale counter 54A ... X drive motor 54B ... Y drive motor 54C ... Z drive motor 56A, 56B ... Scale pattern 58A ... X position detector 58B ... Y position detector 60 ... Transmission Light source unit 60A ... Transmissive light source switch 60B ... Light intensity adjustment volume 62 ... Epi-illumination light source unit 62A ... Epi-illumination light switch 62B ... Light intensity adjustment volume

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Teruaki Iinuma 1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd. (72) Inventor Masataka Yamaji 1-chome, Ichigaya-Kagacho, Shinjuku-ku, Tokyo No. 1 Dai Nippon Printing Co., Ltd.

Claims (5)

[Claims] 1. A CAD device having a function of creating CAD data of a processing dimension pattern which is a prototype of a register pattern based on CAD data of a product design dimension pattern, and a physical pattern used or generated in an etching process with high accuracy. In addition to the image input means for inputting the image by the above, and the raster / vector converting means for converting the input image data into CAD data, the actual product having the function of superposing and collating two or more CAD data It is a collation CAD system, and the function to display the reference CAD data on the monitor screen, in which the reference point for any pattern used or generated in the etching process is clear, and the reference point of the actual pattern corresponding to the reference point of the reference CAD data, The function to calculate and the specified area on the standard CAD data displayed on the monitor screen The function to specify the shooting area of the actual pattern corresponding to the rear, the navigation function to match the field of view of the image input means to the shooting area specified by referring to both reference points, and the field of view to be matched by the navigation function The function of inputting the actual pattern of the captured area, and the raster image vector conversion of the image-input raster image data for each field of view are converted into CAD data corresponding to the actual pattern,
A CAD system having a physical item collating function, which has a function of displaying the CAD data in a designated area of the reference CAD data on the monitor screen. 2. The function according to claim 1, further comprising a function of enlarging and displaying the reference CAD data on the monitor screen, and a physical object collating function characterized by being able to specify an area on the enlarging screen CAD system. 3. The navigation according to claim 1, wherein the field of view of the image input means coincides with the photographing area of the actual pattern, with the reference point as the origin, and the designated area on the reference CAD data displayed on the monitor screen. Based on the coordinate values to be defined, the coordinate value to define the photographing area is determined and executed.
AD system. 4. The navigation according to claim 1, wherein the navigation for matching the visual field of the image input means with the photographing area of the actual pattern has a sample mounting section for fixing the visual field of the image input means and setting the actual article. A CAD system having an actual product collating function, characterized in that the XY stage is driven and controlled. 5. A CAD system having a physical item matching function, wherein pre-input physical item corresponding CAD data is used as the reference CAD data.