JPH0546701A - Automatic formation method for silk mask pattern - Google Patents

Abstract

(57) [Summary] [Purpose] To create an abnormally filled shape and to reduce the number of temporary placements of silk characters, to shorten the silk mask pattern creation period and improve the quality. [Structure] In the generation of the silk symbol of the process 1, the silk symbol shape generation description language 5 based on the basic figures of lines, rectangles, circles and arcs stored in the disk device is used to generate all the silk symbol shapes including the filled shape. Create. In the process of silk character arrangement in process 2, eight arrangeable areas are set in the upper, lower, left, right, and diagonal directions in the vicinity of the component, and if the arrangement is not possible even if the character size is reduced, the arrangeable area is expanded. In the correction of the silk symbol shape in process 3, the through hole, the pad, and the portion overlapping the via hole are cut.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a silk mask pattern on a printed wiring board, and more particularly to an automatic method for producing a silk mask pattern which satisfies many constraints in order to secure the reliability of the printed wiring board. Is.

[0002]

2. Description of the Related Art Conventionally, as a method of creating a silk mask pattern of a printed wiring board by an electronic computer, (1) a method of manually creating a figure editor by digitizing and graphic, (2) "Oki Electric Research and Development, Thirteen
No. 6, Vol. 54 No. 4, Ueda, Izumi: Preset and Post-Data Generation System in Printed Circuit Board Design "and" Technical Techniques Vol. 187 No. 301, "
Izumi, Morino, et al .: Development of high-performance artwork system for printed circuit board by EWS "is known. Hereinafter, they will be described in order. (1) Manual creation method A silk diagram of a printed wiring board is manually drawn, attached to a digitizer device, and digitized to create silk data consisting of silk symbol shape data and silk character data. Next, the created silk data is displayed in the graphic editor, visually checked, and the part which does not meet the design condition is manually corrected by using the graphic processing command to create the silk mask pattern. (2) Method according to the above document a. Generating silk symbol shape By making rule of the silk symbol shape generation description,
Generating a silk symbol shape. Regarding the basic shape of the silk symbol, instead of creating shape generation rules for all parts, DIPIC, diode,
The silk symbol shape is generated by creating the unit for each component type such as capacitor, resistor, SOP, and QFP, and changing the size of the basic shape depending on the number of component pins and the span.

The shape generation rule is automatically converted into a description rule by inputting a basic shape into a graphic display. There are four types of figures that can be represented: line (straight line), rectangle (rectangle), arc (circle and arc), and area (area). area is S
A filled area is defined when a filled shape of a silk symbol such as OP is generated. b. Creating silk characters Set up a rectangle in the top and bottom and left and right directions of the silk character creation area near the part. To search for a character position in the character-creatable area, the upper and lower rectangular areas are searched in that order, starting from a location near the component. At this time, if there is a via hole, a through hole, or another silk character, it is recognized as an obstacle and the character position is searched while avoiding it. If the character position cannot be determined due to the obstacle, the character size is reduced and the same search process is repeated. 2 for size reduction
If the position cannot be determined even after repeating the process and reducing the size, temporarily create silk characters in the center of the part. c. Correction of silk symbol shape The overlap between the silk symbol shape generated in a and the through hole is checked, and the overlapping portion is cut. After cutting is completed, n line and arc
A graphic is formed by, and when the length of one graphic is shorter than a preset length, the graphic is deleted. Further, regarding the area that is a filled area, when a through hole exists in the area, a hollow region is created within a predetermined range to prevent the silk resin from flowing into the through hole.

[0004]

However, the method (1) has the drawback that quality is lowered due to mistakes in preparation and man-hours and time required for preparation are increased due to a large amount of manual intervention. In addition, in the method (2), the fill-shaped silk symbol checks the inclusion relation of the areas created by all the area rules to generate a fill pattern. Therefore, a large number of check items are required for area recognition, and it takes time to generate a fill pattern. Further, there are cases in which the area cannot be recognized sufficiently and a normal filled shape cannot be formed. Further, in a printed wiring board having a high component mounting density, there is often no space for arranging silk characters in the vicinity of the components, and in that case, the silk characters are temporarily arranged in the center of the components. All of the temporarily arranged silk characters were manually modified, which had the problems of increasing the design period and lowering the quality.

The present invention solves the above problems and, in a method of creating a silk mask pattern for a printed wiring board by a computer, creates an abnormally filled shape and reduces the number of temporary arrangements of silk characters, thereby minimizing human intervention. By doing so, it is an object of the present invention to provide a method for automatically creating a silk mask pattern that can shorten the time period for creating a silk mask pattern and improve the quality.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention relates to a silk for a printed circuit board by a computer, which is composed of generation of a silk symbol shape, arrangement of silk characters and correction of the silk symbol shape. In the automatic mask pattern generation method, the silk symbol shape generation is performed by setting a silk symbol shape generation rule for each part type in a silk symbol shape generation description language based on a basic figure of a straight line, a rectangle, a circle and an arc. Create a graphic with a set of basic figures as a silk symbol and fill it with a filled symbol by substituting the minimum rectangle size that includes the component pin or component pad in the silk symbol shape generation rule of the component. Expressed as a set of straight lines, the silk characters are placed vertically near the parts. Set 8 arrangable areas diagonally to the right, then try character arrangement in that area in a predetermined order, considering obstacles, and if not possible, repeat the specified number of times to reduce the character size. Attempt to place letters,
If the characters cannot be arranged even if the size is reduced, the placeable area is enlarged to place the characters, and a leader line is created between the silk shape of the part and the silk symbol character to expand the placeable area. If it cannot be placed, it is temporarily placed in the center of the part, and the silk symbol shape is corrected through the through hole and via for the silk symbol shape generated above.
The silk symbol shape was created by cutting the part that overlaps the hole.

[0007]

According to the present invention, since the silk mask pattern automatic creating method is configured as described above, the silk symbol shape is generated by using the basic figures of straight lines, rectangles, circles and arcs which are stored in the library as a rule base. Input the silk symbol shape generation rule set for each part type in the description language of the base silk symbol shape generation into the computer, and substitute the minimum rectangle size including the part pin or the part pad into the part's silk symbol shape generation rule. As a result, a graphic with a set of basic figures is created as a silk symbol, and the filled symbol is also expressed by a straight line collection shape. , And then try character placement in that area in a predetermined order, considering obstacles, and if it cannot be placed, Repeats a predetermined number of times to reduce the character size and try to arrange the characters. If the characters cannot be arranged even if the size is reduced, expand the arrangeable area to arrange the characters, and make the silk symbol shape and silk characters of the part. If you can not arrange the characters even if you enlarge the placeable area by creating a lead line between them, provisionally place it in the center of the part, and correct the silk symbol shape through the through-hole, A silk symbol shape is created by cutting a portion overlapping with the pad and the via hole.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram of a method for automatically creating a silk mask pattern according to an embodiment of the present invention, FIG. 2 is a diagram showing an outline of a computer system to which the present invention is applied, and FIG. 3 is a diagram of a silk symbol shape in the embodiment of the present invention. Generation flowchart, FIG. 4 is a flowchart of silk character arrangement in the embodiment of the present invention, FIG. 5 is a flowchart of silk symbol shape correction in the embodiment of the present invention, and FIG. 6 is a silk symbol shape generation description in the embodiment of the present invention. FIG. 7 shows a language, FIG. 7 shows an example of silk symbol shape generation in the embodiment of the present invention, FIG. 8 shows another example of silk symbol shape generation in the embodiment of the present invention, and FIG. 9 shows the present invention. FIG. 10 is an explanatory diagram of silk character arrangement in the embodiment of FIG. 10, and FIG. 10 is an explanatory diagram of enlargement of the silk character arrangement area in the embodiment of the present invention.

In FIG. 2, 11 is an EWS for artwork design in which the method for automatically creating a silk mask pattern according to the present invention operates, 12 is a transceiver, 13 is a CPU, 1
A display 4 and a keyboard 15 are connected to a mouse. 16 is a disk device, 17 is a plotter device,
18 is a floppy disk, 19 is a magnetic tape device, 2
Reference numeral 0 is a host computer, 21 is a disk device (library) that stores various design data, silk symbol generation description language, and the like, and 22 is a local area network.

The EWS 11 for artwork design inputs design data (layout design data) after component layout design, wiring design and design rule verification in the board layout design process from the disk device (library) 21 to the disk device 16 and prints it. Create the data required for board manufacturing. In addition to the present invention, it has a function of automatically creating a power / ground interior pattern and a resist pattern.

As shown in FIG. 1, the method for automatically creating a silk mask pattern according to the embodiment of the present invention is as follows: (1) generation of a silk symbol shape (process 1);
(2) Silk character arrangement (process 2) and (3) silk symbol shape correction (process 3).
Further, in FIG. 1, reference numeral 4 indicates an operation for inputting the basic shape of the silk symbol using the CRT 14 and the keyboard 15 of FIG. 2, and reference numerals 5 and 6 are read from the disk device (library) 21 and stored in the disk device 16. Silk symbol shape generation language, layout design data, 7
Indicates a parameter file stored in the disk device 16, 8 indicates that the silk data created by the processes 1 to 3 is stored in the disk device 16, and 9 indicates the silk data stored in the disk device 16 with a graphic editor. Indicates the operation to modify.

An embodiment of the present invention will be described below with reference to FIGS. (1) Generation of Silk Symbol Shape (FIG. 3) The silk symbol shape is generated by rule-based silk symbol shape generation language. Regarding the basic shape of the silk symbol, it is not necessary to create a shape generation rule for all parts, and 1 for each part type unit such as IC, resistor, capacitor, diode, SOP, and QFP.
It suffices that there are types, and by changing the size of the basic shape of the silk symbol depending on the number of component pins and the span, the silk symbol shapes of all components can be created.

The silk symbol shape generation description language of this embodiment is line (straight line), recta as shown in FIG.
It is possible to represent three types of figures: single (rectangle) and arc (circle and arc). The shape of the filled symbol such as SOP is the same as the shape generation rule shown in FIG.
To generate a filled symbol shape. Further, FIG. 8 shows a DIPIC shape generation rule.

(2) Arrangement of Silk Characters (FIG. 4) As shown in FIG. 9, the silk characters must be set so that they can be seen even after the parts are mounted and do not overlap the through holes, pads or Via holes. .. In the present invention, in the vicinity of the parts, the upper, lower, left, and right, diagonally disposable areas (A),
(B), (C), (D), (E), (F), (G),
(H) is set as a rectangle. The size of the rectangle can be selected by the parameter file 7 according to the mounting density of the printed circuit board. Searching for the character position in the arrangeable area is performed by the areas (A), (B), (C), (D),
(E), (F), (G), and (H) are searched in this order from positions near the parts. Further, the search interval (interval between lines 1 to 5 in the figure) in each area is also selected by the parameter file 7. At this time, if there are Via holes, through holes, pads, silk symbol shapes and other silk characters,
Recognize it as an obstacle and avoid it and search for the character position. When the character cannot be set due to the obstacle, the character size is reduced and the search process is repeated again. The size reduction is performed the number of times specified in the parameter file 7. If the position cannot be determined even if the size is reduced, as shown in FIG. 10, the allocable area is enlarged and the search range is expanded to search for a free space and arrange it. At this time, since the distance between the part and the silk character becomes long, a leader line is created. This is effective in clarifying the relationship between parts and silk letters and preventing correction mistakes. If the character layout cannot be determined even with this, temporary placement is performed at the center of the part. (3) Correction of the silk symbol shape (Fig. 5) If the silk symbol shape overlaps the through holes or via holes, it may interfere with component insertion, prevent sufficient soldering processing, and cause malfunctions such as equipment malfunction due to corrosion of the through holes. Occur. Therefore, in the present invention, the silk symbol shape generated in (1) above is corrected according to the design / manufacturing rules. For example, the overlap check with the through hole, the pad, and the Via hole is performed, and the overlapped portion is cut. After the cutting is completed, if the length of one figure is shorter than the length set in the parameter file 7, the figure is deleted if necessary. The fill shape of SOP, etc.
Since it is composed of ne, it is possible to create a hollow in the through hole in the filled shape by the overlapping cutting process.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention, which are not excluded from the scope of the present invention.

[0016]

As described above in detail, according to the present invention, all the silk symbol shapes including the filled shapes are created by the silk symbol shape generation language based on the basic figures of lines, rectangles, circles and arcs. Since it is possible to create, the time required to generate a normal fill pattern can be shortened.

Further, since the eight allocable areas are set and the allocable area is enlarged, the number of provisionally arranged silk characters can be reduced. Therefore, it is possible to shorten the silk mask pattern creation period, reduce the design man-hour, and improve the design quality.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a method of automatically creating a silk mask pattern according to an embodiment of the present invention.

FIG. 2 is a diagram showing an outline of a computer system to which the present invention is applied.

FIG. 3 is a flowchart of generating a silk symbol shape according to an embodiment of the present invention.

FIG. 4 is a flowchart of silk character arrangement according to an embodiment of the present invention.

FIG. 5 is a flowchart of silk symbol shape correction according to the embodiment of the present invention.

FIG. 6 is a diagram showing a silk symbol shape generation description language in the embodiment of the present invention.

FIG. 7 is a diagram showing an example of silk symbol shape generation in the embodiment of the present invention.

FIG. 8 is a diagram showing another example of silk symbol shape generation in the embodiment of the present invention.

FIG. 9 is an explanatory diagram of silk character arrangement in the embodiment of the present invention.

FIG. 10 is an explanatory diagram of expansion of a silk character arrangement area in the embodiment of the present invention.

[Explanation of symbols]

 1 Silk symbol shape generation 2 Silk character arrangement 3 Silk symbol shape correction

Claims (1)

[Claims] 1. A method of automatically creating a silk mask pattern by a computer of a printed circuit board, the method including: generating a silk symbol shape, arranging silk characters, and correcting the silk symbol shape, ) Silk symbol shape generation based on basic shapes of straight lines, rectangles, circles and arcs Set a silk symbol shape generation rule for each part type in the description language and create a library as a rule base. (B) Silk of the part By substituting the minimum rectangle size including the part pin or the part pad into the symbol shape generation rule, a figure based on the set of the basic figures is created as a silk symbol, and (c) and the filled symbol is also a set of straight lines. The silk letters are arranged as follows: (E) Next, character arrangement is tried in consideration of obstacles in a predetermined order, and when the area cannot be arranged, the character size is reduced by repeating a predetermined number of times. Attempt to arrange characters, and (f) If the characters cannot be arranged even if the size is reduced, expand the arrangeable area to arrange the characters, and create a leader line between the silk symbol shape and silk characters of the part. (G) If the character arrangement is not possible even if the allocable area is expanded, the character is temporarily arranged in the center of the component, and the silk symbol shape is corrected by using through holes, pads and vias for the silk symbol shape generated above. A method for automatically creating a silk mask pattern, which is characterized by creating a silk symbol shape by cutting a portion that overlaps a hole.