JP3365328B2 - Method for automatically generating negative figures in printed wiring board CAD - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphic shape changing process in a printed wiring board, and more particularly to a method for automatically generating a negative graphic in a printed wiring board CAD.
It is related to the law .

[0002]

2. Description of the Related Art In CAD technology for printed wiring boards,
Various automatic design techniques and automatic verification techniques have been proposed. This can not only speed up the work itself, but also avoid errors that cannot be avoided in manual work. For example, Japanese Patent Laid-Open No. 2-287881 (Japanese Patent No. 2580772) proposes a printed wiring board circuit design rule verification device. With such an automatic device, it is possible to improve the efficiency of the printed wiring board circuit design by automatically detecting and correcting a defect in the printed wiring board circuit design.

On the other hand, in a multi-layered printed wiring board which is widely used at present, a copper foil is sandwiched between substrate material layers. In such a structure, when there is a copper foil having a large area which functions as a ground wire or a power supply wire, warpage or twisting occurs due to heat or the like because the substrate material and the copper foil have different coefficients of thermal expansion.
Furthermore, since the board adhesive does not adhere to the copper foil surface, there may be a gap in the copper foil part with a large area.
In a printed wiring board having a multilayer structure, the adhesion strength between the substrate material layers may be insufficient.

Therefore, by forming a so-called negative pattern (a blank pattern) on a copper foil portion having a large area and partially removing the copper foil portion, the adhesive adheres to the substrate material layer. The adhesion strength between the substrate material layers has been increased. By doing so, even if the expansion coefficient of the substrate material and that of the copper foil are different, the residual rate of the copper foil is reduced, and the adhesion strength between the substrate material layers is increased. As a result, it is possible to suppress warpage and twist of the printed wiring board having a multilayer structure. Further, it is possible to provide the printed wiring board having a multilayer structure with a sufficient integrity.

However, according to the conventional method, the clearance land, the conductive land, and the separate line existing in the solid pattern in the wiring pattern of the printed wiring board corresponding to the copper foil portion having a large area are visually checked while manually avoiding them. Create a negative graphic. After creating the negative pattern, it was checked whether the remaining width of the solid copper foil was too thin.

[0006]

However, this conventional technique has the following problems. The first problem is that it takes time to create a negative figure. The reason is that it is done manually. The second problem is that check omission may occur. The reason is that a manual check is performed on each solid figure, and thus the possibility of work omission cannot be avoided.

In connection with the above technique, Japanese Patent Laid-Open No. 4-3507
Japanese Patent Publication No. 72 proposes a pattern design data processing device for a printed wiring board, which automatically equalizes the pattern area density at the design stage. This printed wiring board pattern design data processing device detects a vacant space on the printed wiring board after wiring based on the pattern design data of the printed wiring board, and places dummy patterns in the detected vacant space at regular intervals. Dummy pattern data for placement is automatically generated. The dummy pattern data thus generated is added to the pattern design data of the printed wiring board and output as final pattern design data.

However, the pattern design data processing device for a printed wiring board disclosed in Japanese Patent Laid-Open No. 4-350772 occurs when the copper foil pattern is formed by electrolytic plating depending on the non-uniformity of the circuit pattern density. It is intended to prevent the variation in the thickness of the copper foil pattern due to the nonuniform current density. However, in this technique, dummy patterns are arranged at regular intervals in an empty space where there is no copper foil pattern, and when there is a solid pattern copper foil pattern, it is maintained as it is. . Therefore, the above problem cannot be solved.

Further, Japanese Patent Laid-Open No. 8-235237 proposes an automatic wiring method and an automatic wiring device for a printed wiring board. In order to meet the recent demand for high-density mounting / arrangement, this automatic wiring method and automatic wiring device set a wiring control area for performing automatic wiring under specific wiring conditions in advance in a complicated wiring area, and Within the established wiring control area, automatic wiring is performed under specific wiring conditions to automatically perform finely set / designated wiring. However, the above-mentioned problems of the prior art are not mentioned at all.

Therefore, the present invention is to provide a method and apparatus for automatically generating a negative figure in a printed wiring board CAD, which solves the above-mentioned problems of the prior art.

[0011]

[0012]

According to the method of the present invention,
Design database section, rule check section, and shape addition section
In a printed wiring board CAD including at least
A method for automatically generating arbitrary negative figures according to given rules for solid figures in the wiring patterns of already designed printed wiring boards stored in the design database section.
In the rule check part, first, it is checked whether the point of the generated negative figure is within the circumscribed rectangle of the solid figure. If it is within the circumscribed rectangle of the solid figure, the point of the generated negative figure is , Check whether it is within the solid figure, and if the point of the generated negative figure is within the solid figure, the outer edge of the generated negative figure is
It is checked whether the contour of the solid figure is more than a predetermined distance from the contour, and if the outer edge of the generated negative figure is more than the predetermined distance from the contour of the solid figure, the shape adding unit
The generated negative figure is added to the solid figure in the wiring pattern of the designed printed wiring board stored in the database section .

Further, when a negative figure exists in the solid figure, it is checked whether the outer edge of the generated negative figure is more than a predetermined distance from the outline of the negative figure in the solid figure,
If the outer edge of the generated negative figure is more than a predetermined distance from the outline of the negative figure in the solid figure, add the generated negative figure to the solid figure in the wiring pattern of the designed printed wiring board. .

Further, in a multilayer printed wiring board, a negative figure added to a solid figure in a wiring pattern of one layer and a solid figure in a wiring pattern of a layer adjacent to the layer are And the negative shape added by
Arrange them so that they are offset from each other in the plane pattern.

[0015]

[0016]

With the above configuration, it is possible to automatically generate an arbitrary negative figure in the solid figure in the wiring pattern of the already designed printed wiring board. Since the negative figure is automatically generated while observing the criteria specified in the rule,
Negative figures can be created in a short time. Further, since it is not a manual work, there is no omission of checking solid figures and omission of generation of negative figures. Further, since the rule can be specified for each layer, it is possible to prevent the negative figures of the adjacent layers from overlapping each other in the printed wiring board having a multi-layer structure, thereby reducing the unevenness of the substrate.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram illustrating the basic configuration of an apparatus according to the present invention for automatically generating a negative figure on a printed wiring board CAD.

The apparatus shown in FIG. 1 accesses the design database unit 10 which stores the wiring pattern data of the already designed printed wiring board to access the wiring pattern data of the target already designed printed wiring board. For the solid pattern detected by the solid pattern detected by the solid pattern detected by the solid pattern detected by the solid pattern detected from the above various solid pattern indexes, the rule storing unit 14 for storing the rule for generating the negative solid pattern (void pattern). A shape adding unit 16 that generates a negative graphic according to the rule stored in the rule storage unit 14 and a rule check unit 18 that determines whether or not the generated negative graphic matches the rule.

When the rule check unit 18 determines that the generated negative graphic is consistent with the rule,
The shape adding unit 16 adds the generated negative graphic to the wiring pattern data of the target printed wiring board that has been designed and is stored in the design database unit 10. Rules can be defined for each layer to be processed in a multilayer printed wiring board. As rules, the method of arranging negative figures (staggered grid or even grid), horizontal spacing value, vertical spacing value, solid pattern The distance value from the copper foil contour and the negative graphic shape name to be generated can be described.

Further, the illustrated apparatus is provided with a library section 20 in which the actual shape of the negative graphic to be generated is registered, and the shape adding section 16 accesses the library section 20 to generate the generated negative graphic shape. The actual shape of the negative figure is generated based on the name and is output to the design database unit 10. The configuration of FIG. 1 is realized by a computer. In that case, the design database unit 10 and the library unit 20 are memories attached to or connected to the computer, and include the figure recognition unit 12, the rule storage unit 14,
The shape adding unit 16 and the rule checking unit 18 are realized by a program.

Next, the flowchart of FIG. 2 and FIGS. 3 and 4
The overall operation of this embodiment will be described in detail with reference to FIG. First, the figure recognizing unit 12 accesses the design database unit 10 that stores the wiring pattern data of the already designed printed wiring board, and in the wiring pattern data of the target already designed printed wiring board, A solid figure for which a negative figure is to be generated is recognized (step 1).
Since there are figures with various figure indexes such as wiring, lands, and prohibited areas in the data, the solid figure with the index of the solid figure is recognized from among them.

Next, a rule is designated (step 2). That is, the rule for generating the negative graphic is written in the rule storage unit 14. As a rule, for the layer name (a), the horizontal gap value (b), the vertical gap value (c), the gap from the copper foil edge (solid contour or other clearance land, conduction land, separate line) A value (d), a name (e) of the shape of the generated negative figure, and an alignment method (f) indicating the staggered grid or the uniform grid are input.

As specifically shown in FIG. 3, the horizontal gap value (b) and the vertical gap value (c) are defined by the points of the negative figures (for example, the negative figures are circular or oval). In the case of a regular polygon or a rectangle, it is the distance between the centers, and the gap value (d) from the edge of the copper foil (outline of the solid figure)
Is the minimum distance that must be secured from the outer edge of the negative graphic to the outline of the solid graphic. In addition, (b) (c)
(D) is a positive integer. In the example shown in FIG. 3, the negative shape shape name (e) designates a circular shape, and the alignment method (f) designates a houndstooth check. The actual shape of the generated negative figure is registered in the library. Furthermore, the point of the negative graphic is not limited to the center when the negative graphic is a circle, an ellipse, a regular polygon, or a rectangle, but may be a predetermined point on the outer edge of the negative graphic. For example, when the negative figure is a square or a rectangle, it may be a point at the lower left corner of the square.

When the rule is designated, an instruction to generate it is issued (step 3). The shape addition unit 16 accesses the figure recognition unit 12 based on the layer name (a) described in the rule storage unit 14, and selects from among the plurality of solid figures recognized by the figure recognition unit 12, A solid figure (copper foil) existing in the layer with the layer name (a) is selected, and the circumscribed rectangle of the solid figure is calculated. Further, as shown in FIG. 4A, the shape adding unit uses the lower left of the circumscribing rectangle g as a reference point (the origin (0, 0) of the XY coordinates) and sets the point of the negative figure (e) as the reference point. To (d, d) relative positions (step 4) (FIG. 4 (1)). The point of this first negative figure (e) is stored as the initial position.

When the point of the negative figure is the lower left corner of the negative figure, it is sufficient to generate the point of the negative figure (e) at the relative position (d, d) from the reference point. , If the point of the negative figure is the center of the negative figure (circle, oval, regular polygon or rectangle center), the horizontal and vertical distances from the center of the negative figure to the outer edge of the negative figure , The point of the negative figure is generated at the relative position added to the distance from the reference point to (d, d). Figure 3
When the negative figure is a circle having a radius r, as shown in, the point of the negative figure is generated at a distance of (d + r, d + r) from the reference point.

Next, in step 5, the rule check unit 18 checks whether the points of the generated negative graphic exist inside the solid graphic which should generate the negative graphic (which is inscribed in the circumscribed rectangle g). . this is,
This process is not necessary when the solid figure and the circumscribed rectangle of the solid figure match. However, when the solid figure and the circumscribed rectangle of the solid figure do not match, the solid figure is naturally This processing is necessary because it is smaller than the circumscribed rectangle of. However, FIG. 4 shows an example in which the solid figure and the circumscribed rectangle of the solid figure are coincident with each other for convenience of description.

Further, when it is judged that the points of the generated negative graphic exist inside the solid graphic, it is checked whether the negative graphic violates the rule (d). That is, the rule check unit 18 accesses the library unit 20 based on the shape name of the negative graphic (e) and determines the negative graphic (e) from the actual shape of the negative graphic (e) and the point of the negative graphic (e). The position of the outer edge is obtained, and it is checked whether or not the position of the outer edge is apart from the contour line of the negative figure by a distance d or more. When the negative figure is a circle, an ellipse, a regular polygon, or a rectangle, the outer edge of the negative figure (e) has four points in total, that is, the edges of the horizontal direction and the edges of the vertical direction. It is only necessary to check whether or not the distance is more than d.

If any of the above checks are violated,
The generation of the point of the negative figure at this position is invalidated (step 6), and the process proceeds to step 8. If there is no violation, the actual shape of the negative figure (e) is added to this position (step 7). That is, the shape adding unit 16 accesses the library unit 20 based on the shape name of the negative graphic (e) and reads the actual shape of the generated negative graphic (e), as shown in FIG. Then, the negative figure e1 having the actual shape is added to the corresponding solid figure g of the wiring pattern data of the already designed designed printed wiring board stored in the design database section.

If the actual shape of the generated negative figure (e) is added to the wiring pattern data of the designed printed wiring board, the point of the negative figure (e) is set horizontally (2 × b). (Step 8), and then it is checked whether or not the moved point has reached the contour of the circumscribed rectangle g (contour edge H of FIG. 4A) in the horizontal movement (step 9).

If the contour is not reached, it means that the point of the second negative figure (e) is within the circumscribed rectangle of the solid figure, and the process returns to step 5. That is, like the first negative figure, the points of the second negative figure should generate the negative figure (inscribe the circumscribed rectangle g).
It is checked whether the negative figure exists inside the solid figure. If it is determined that the negative figure exists inside the solid figure, it is checked whether the negative figure violates the rule (d). If none of the above checks are violated, the actual shape of the negative figure (e) is added to this position (step 7). Figure 4
As shown in (2), the negative figure e2 of the actual shape is added to the corresponding solid figure g.

The above processing is repeated until the contour of the circumscribed rectangle is reached in the horizontal movement. In step 9, the moved point is the outline of the circumscribed rectangle g (see FIG.
When it reaches the contour edge H of (1), it returns to the initial position and moves vertically (c) from the initial position as shown in FIG. 4C (step 10). At this time, since the alignment method is described in the zigzag pattern and the rule, it is further moved by (b) in the horizontal direction. A negative graphic point is generated at this position.

Next, the generated point is the contour of the circumscribed rectangle g in the vertical movement (contour edge V in FIG. 4C).
Check whether or not (step 1
1). If the outline of the circumscribing rectangle g is not reached in the vertical movement, it means that the point of the negative figure (e) is within the circumscribing rectangle of the solid figure, and the process proceeds to step 5
Return to. After that, the processing from step 5 to step 11 (including, of course, the repetition of the processing returned in step 9)
repeat. In the process, as shown in FIG. 4C, the negative figure e3 of the actual shape is added to the solid figure g, and the negative figure e3 is the negative figure e1 and the negative figure e.
They are displaced from each other in a zigzag pattern with respect to the negative graphic in the first column including 2.

In the repeating process of the above steps 5 to 11, the points generated are
When the contour of the circumscribed rectangle g (contour edge V in FIG. 4 (4)) is reached in the vertical movement, the processing is completed, and
As shown in (4), negative graphics according to the rules are arranged in the solid graphics g and arranged by a predetermined negative graphic alignment method (in this example, a houndstooth check).

Next, another embodiment of the present invention will be described. In the case of the first embodiment, there is no other figure in the solid figure, but the same effect can be obtained even when another negative figure k exists in the solid figure g as shown in FIG. To be In this case, the gap value of the item (d) specified by the rule is also applied to the contour of the negative figure k.

When the negative figure e is generated as shown in FIG. 5 (1), the rule check unit of FIG. 1 processes the generation of the negative figure e indicated by the thick line circle as an invalid result. , A figure intended by the designer is obtained as shown in FIG. Clearance land, as well as negative figures
Since the same check is performed for the separate line and the conductive land, the figure intended by the designer can be obtained.

In the case of the above-described embodiment, the staggered grid alignment method is used. However, when the uniform grid alignment method is designated, step 10 of the first embodiment is performed as follows. Replaced. It returns to the initial position, moves vertically (c) from the initial position, and does not move further in the horizontal direction because the alignment method is described in the uniform grid and rule. A negative graphic point is generated at this position.

An example in which the unevenness of the printed wiring board can be reduced will be described with reference to FIG. As shown in FIG. 6A, a negative graphic ea is generated in the solid graphic g1 on the first layer surface of the substrate. Next, the negative figure eb is also generated for the solid figure g2 on the second layer surface by the same reference. The first negative figure eb to be generated for the solid figure g2 on the second layer surface is the upper layer (first
If it is the same point as the generation point of the negative figure (negative figure ea) existing on the layer surface), the distance b is first in the horizontal direction.
The point of the negative figure is derived by shifting it. Hereinafter, the same processing is continued. Thus, as shown in FIG. 6B, the negative graphic eb is generated in the solid graphic g2 on the second layer surface. As a result, as shown in FIG. 6C, the solid figure g1 of the first layer surface
The negative figure ea in the inside and the negative figure eb of the solid figure g2 on the second layer surface can be displaced from each other, and the unevenness of the printed wiring board can be reduced.

[0038]

According to the method and apparatus for automatically generating a negative figure in the printed wiring board CAD according to the present invention as described above, the following effects can be obtained. The first effect is that the warp and twist of the substrate can be suppressed. The reason is that the expansion coefficient of the substrate material and the copper foil is different due to heat, so warping and twisting occur if there is a large area copper foil, but by adding a negative figure, the area of the copper foil decreases, This is because the adhesion strength between the substrate material layers is increased. The second effect is an improvement in substrate adhesion strength. The reason is that the board adhesive does not adhere to the copper foil surface and there may be gaps in the copper foil part with a large area, but by adding a negative figure to the copper foil part with a large area, the copper foil This is because the area decreases, the adhesive adheres, and the adhesion strength increases.

The third effect is that a negative figure can be created in a short time. The reason is that it occurs automatically while observing the criteria specified in the rules. The fourth effect is
It is possible to reduce the unevenness of the substrate. The reason is that since the rule can be specified for each layer, the negative graphic can be prevented from overlapping the negative graphic of the adjacent layer.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating the basic configuration of an apparatus according to the present invention for automatically generating a negative figure on a printed wiring board CAD.

FIG. 2 is a flow chart illustrating a first embodiment of a method according to the present invention for automatically generating a negative graphic on a printed wiring board CAD.

FIG. 3 is a diagram illustrating rules for generating a negative figure in the first embodiment of the method according to the present invention.

FIG. 4 is a diagram illustrating a negative graphic produced by a first embodiment of the method according to the present invention.

FIG. 5 illustrates a negative graphic produced by a second embodiment of the method according to the invention.

FIG. 6 illustrates a negative graphic produced by a third embodiment of the method according to the present invention.

[Explanation of symbols]

10 Design Database Department 12 Figure recognition unit 14 Rule storage 16 Shape addition part 18 Rule Check Department 20 library department

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Claims (3)

(57) [Claims] 1. A design database section and a rule check section
And a printed wiring board C including at least a shape adding portion
In AD, an arbitrary negative figure is automatically set according to a given rule with respect to a solid figure in the wiring pattern of the already designed printed wiring board stored in the design database section.
In the method that occurs, in the rule check part, first check whether the point of the generated negative figure is within the circumscribed rectangle of the solid figure, and if it is within the circumscribed rectangle of the solid figure, Check whether the point is in the solid figure, and if the point of the generated negative figure is in the solid figure, the outer edge of the generated negative figure is more than a predetermined distance from the outline of the solid figure. What Check, generated outer edges of the negative figure there are, in the case where the outline of the solid figure is away a predetermined distance or more, the shape
The addition unit adds the generated negative graphic to the solid graphic in the wiring pattern of the designed printed wiring board stored in the design database unit. Automatic generation method. 2. When a negative figure exists in a solid figure,
Check whether the outer edge of the generated negative graphic is more than a predetermined distance from the contour of the negative graphic in the solid graphic, and the outer edge of the generated negative graphic is more than the predetermined distance from the contour of the negative graphic in the solid graphic. The method for automatically generating a negative graphic in a printed wiring board CAD according to claim 1 , wherein the generated negative graphic is added to the solid graphic in the wiring pattern of the designed printed wiring board. 3. In a multilayer printed wiring board, 1
The negative figure added to the solid figure in the wiring pattern of one layer and the negative figure added to the solid figure in the wiring pattern of the layer adjacent to that layer should be offset from each other in the plane pattern. The method for automatically generating a negative figure in the printed wiring board CAD according to claim 1 or 2 , characterized in that the negative figure is arranged.