JPH0581373A - Multi-layer printed board and its land pattern designing method - Google Patents

Abstract

PURPOSE:To decrease the number of triangles in the case a land pattern is decomposed by forming the land pattern as a rectangle and cutting off both corner parts by a straight line in the case rectangular corner parts of adjacent land patterns are close to each other. CONSTITUTION:In the multi-layer printed board, in order to connect layers, a pier hole 12 for passing through a base material layer 10 is packed with an electric conductor 14, and thin electric conductor land patterns 16, 161-166 for covering the end face of the electric conductor 14 are attached as wiring patterns to the base material layer 10. In this case, the land pattern is a rectangle in principle, and when rectangular corner parts of adjacent land patterns are close to each other, it becomes the land pattern of a shape in which both corner parts are cut off by a straight line. Therefore, as for the multi-layer printed board, in the case the land pattern is decomposed into the fundamental graphics of a triangle and a rectangle, the number of triangles becomes the necessary minimum. Accordingly, in the case of forming the mask of a reticle, etc., of the land pattern by electron beam plotting, an electron beam plotting time and a plotting data generating time are shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer printed circuit board and a land pattern designing method therefor.

[0002]

2. Description of the Related Art In a multi-layer printed circuit board for high-density mounting, a via hole 12 is formed in a base material layer 10 for inter-layer wiring and a conductor 1 is formed in the via hole 12 as shown in FIG.
4, and thin conductor land patterns 161 and 181 are deposited on both surfaces of the base material layer 10 with the conductor 14 as the center. In the case of high-density mounting, if the land patterns 161 are rectangular, short-circuiting occurs when the land patterns are adjacent to each other at the corners. If the rectangular size is reduced, the conductive resistance between the land pattern 161 and the filling conductor 14 cannot be guaranteed due to the relative displacement between the land pattern 161 and the via hole 12.

Therefore, in such a case, as shown in FIG. 5 (A), the land patterns 161 and 162 have an octagonal shape obtained by cutting a rectangular rectangle with a straight line.

[0004]

However, when a mask such as a reticle having a land pattern is formed by electron beam writing, as shown in FIG.
1 is decomposed into basic figures of triangles A to D and rectangles E to G, and each basic figure is decomposed into stripes corresponding to electron beam scanning. In order to make the outer shape of the figure drawn by the electron beam smooth, the width of the stripe a forming the triangle A must be narrower than the width of the stripe f forming the rectangle F. The time becomes longer, and the electron beam writing data generation time also becomes longer. This problem becomes more serious as the density of component mounting increases.

Further, as shown in FIG. 6B, for example, after the triangle A and the rectangle E are thickened by the shift processing to form the triangle A'and the rectangle E ', the graphic OR of the triangle A'and the rectangle E'is obtained. If it is taken, an unnecessary protrusion is partially formed, which is not preferable.

In view of the above problems, an object of the present invention is to obtain a multilayer printed circuit board in which the number of triangles is reduced as much as possible when the land pattern is decomposed into basic triangle and rectangular figures, and to obtain this multilayer printed circuit board. It is to provide a land pattern design method.

[0007]

[Means for Solving the Problem and Its Action] FIG. 1 (A)
Shows the principle configuration of the multilayer printed circuit board according to the present invention, and FIG. 1 (B) shows the principle configuration of the land pattern design method.

In this multilayer printed circuit board, the conductor 1 is provided in a via hole 12 penetrating the base material layer 10 in order to connect the layers.
4 and the thin conductor land patterns 16, 161 to 166 covering the end faces of the conductors 14 are attached to the base material layer 10 as wiring patterns. As a general rule, the land pattern has a rectangular shape, and when the rectangular corners of adjacent land patterns are close to each other, the land pattern has a shape obtained by cutting the both corners with straight lines.

In the multilayer printed circuit board having the above structure, the number of triangles is minimized when the land pattern is decomposed into basic figures of triangles and rectangles. Therefore, when a mask such as a reticle of a land pattern is formed by electron beam drawing, the electron beam drawing time can be shortened and the electron beam drawing data generation time can also be shortened. Further, it is possible to reduce the number of unnecessary protrusions formed when the land pattern is decomposed into basic figures and shift processing is performed to obtain the figure logical sum.

This multilayer printed circuit board can be layout-designed by using the following land pattern designing method according to the present invention.

(1) The land pattern code Ri, the land pattern common code r, and the land pattern detailed code C
i and the land pattern position coordinates Pi, (2, 3)
Vector PiP having adjacent position coordinates Pi and Pj as end points
When j satisfies the condition of the specific direction and the specific length, the land pattern detailed codes Ci, Cj are set to rectangular codes Ci, Cj in which the corners in the direction are cut off by straight lines,
(2, 4) Rectangular code C when the condition is not satisfied
i and Cj, and (5) the land pattern corresponding to the land pattern detail code Ci is assigned.

In the first aspect of the above-mentioned method invention, the land pattern detail code Ci is initially given a rectangular code, and the vector PiPj whose adjacent position coordinates are end points.
If the condition satisfies the condition of the specific direction and the specific length, the land pattern detail code Ci is generated by changing the code to a rectangular shape in which the corners in the direction are cut off by a straight line.

With this configuration, the land pattern detail code Ci can be easily generated.

On the contrary, according to the present invention, an octagonal code obtained by cutting a rectangular square with a straight line is first added to the land pattern detailed code Ci, and the adjacent position coordinates are defined as end points. When the vector PiPj to be performed does not satisfy the condition of the specific direction and the specific length, the land pattern detail code Ci may be generated by changing the code of the shape in which the corner portion of the direction is not cut by a straight line.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows an outline of wiring pattern generation in layout design. FIG. 3A is a schematic flowchart of mask pattern generation executed by CAD.

(20) Automatic wiring is performed after cell placement. By this wiring, the land pattern 161 shown in FIG.
Is also arranged as a type of wiring. The wiring pattern is represented by a pattern code at this stage, and the land pattern 16
The code of 1 is represented by the same land pattern common code r except for the position coordinates.

(22) The land pattern code is subdivided as described later.

As a result of the processing of steps 20 and 22, FIG.
The pattern code file 26 shown in (B) is obtained.

(24) For each code included in the pattern code file 26, a pattern is allocated by referring to the code / pattern conversion file 28 in which the code and the pattern are associated with each other, and the wiring pattern file 30 is generated.

Next, details of the processing in step 22 will be described. FIG. 4 is a flowchart of this processing, and FIG. 2 is an explanatory diagram of this processing.

Here, the land pattern code Ri (i =
1 to n) are represented by rCiPi. Ci is the land pattern detail code, and Pi is the barycentric coordinate (Xi, Yi) when the land pattern is rectangular.

The land pattern detail code Ci is shown in FIG.
As shown in (B), it has 4 bits, and when all bits are '0', it represents a rectangle, and each bit represents whether or not the corner portion of the land pattern shown in FIG. 2 (A) is cut off. That is, when viewed from the inside of the land pattern, the upper left corner, the lower left corner, the lower right corner and the upper right corner correspond to the 0th, 1st, 2nd and 3rd bits of the detailed land pattern code Ci, and each bit is:
If the corner is a straight line and not cut, it is set to "0", and if it is cut, it is set to "1". For example, the detailed code of the land pattern 161 is represented as C1 = '0100'. Similarly, the detailed codes of the land patterns 162 to 166 are represented by C2 to C6 in FIG.

Next, the land pattern code subdivision procedure,
That is, the procedure for generating the land pattern detail code Ci will be described with reference to FIG.

(40) Clear all land pattern detail codes Ci, i = 1 to n. In other words, the land pattern detail code Ci is basically a rectangular code.

(42) The land pattern code Ri is read from the pattern code file 26 of FIG. 3 (B). Only for the first time, the land pattern code Ri for two lines is read.
For example, in FIG. 2A, the land pattern 1 of the first row
61 to 163 and the land pattern 164 of the second row are read.

(44) If all the land pattern codes Ri have been read before the processing of step 42, the processing is terminated, and if not, the processing proceeds to the next step 46.

(46) Attention is paid to the land pattern code Ri in the ascending order of the X coordinate shown in FIG. Regarding the land pattern code Ri of interest, it is checked whether or not another land pattern code Rj that is close to the land pattern code Ri is located at the lower right of the land pattern code Ri. That is, the land pattern code Ri of the position coordinate Pi (Xi, Yi)
On the other hand, it is checked whether or not another land pattern code Rj exists at the position coordinate Pj (Xi + ΔX, Yi + ΔY). In other words, it is checked whether or not the vector PiPj whose end points are the adjacent position coordinates Pi and Pj satisfy the condition of the specific direction and the specific length.

(48) If another land pattern code Rj exists, the second bit of the land pattern detail code Ci at the position coordinate Pi is set, and the 0th bit of the land pattern detail code Cj at the position coordinate Pj is set. set. For example, in FIG. 2A, the land pattern 161
If you are paying attention to the land pattern 164
Exists, the second of the land pattern detail code C1
Set the fourth bit of the bit and land pattern detail code C4. Next, the land patterns 162 and 163.
The same process as that of the land pattern 161 is performed.

(50) Attention is paid to the land pattern code Ri in the ascending order of the X coordinate shown in FIG. For the land pattern code Ri of interest, it is checked whether or not another land pattern code Rj that is close to the land pattern code Ri is present on the upper right of the land pattern code Ri. That is, the land pattern code Ri of the position coordinate Pi (Xi, Yi)
On the other hand, it is checked whether or not another land pattern code Rj exists at the position coordinate Pj (Xi + ΔX, Yi−ΔY). In other words, it is checked whether or not the vector PiPj whose end points are adjacent position coordinates satisfies the condition of the specific direction and the specific length. However, it is not necessary to perform this process for the first time.

(48) If another land pattern code Rj exists, the third bit of the land pattern detail code Ci is set and the first bit of the land pattern detail code Cj is set. For example, in FIG. 2 (A),
When attention is paid to the land pattern 164, since the land pattern 162 exists at the upper right of the land pattern 164, the third bit of the land pattern detail code C4 and the first bit of the land pattern detail code C2 are set. Then, the process returns to step 42.

As described above, only when the corners are close to each other and adjacent to each other, the optimum land pattern code in which the corners are cut by a straight line can be obtained. Code in Figure 3 (B) /
The pattern conversion file 28 stores a pattern for each land pattern detail code Ci, as shown in FIG.
In step 24 of (A), the land pattern detail code Ci
The pattern corresponding to is assigned.

[0033]

As described above, in the multilayer printed circuit board according to the present invention, when the land pattern is decomposed into basic figures of triangles and rectangles, the number of triangles becomes the minimum necessary,
Therefore, when a mask such as a reticle for a land pattern is formed by electron beam drawing, the electron beam drawing time can be shortened, the electron beam drawing data generation time can be shortened, and the land pattern can be decomposed into basic figures. Then, it is possible to reduce the number of unnecessary protrusions formed when the shift process is performed to obtain the logical OR of the figures.

This multilayer printed circuit board can be layout-designed by using the land pattern designing method according to the present invention.

According to the first aspect of the present invention, it is possible to easily generate the land pattern detail code.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram of a multilayer printed circuit board and a land pattern designing method therefor according to the present invention.

FIG. 2 is an explanatory diagram of subdivision of land pattern codes according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of wiring pattern generation in layout design.

FIG. 4 is a flowchart showing a land pattern code subdivision procedure of FIG.

FIG. 5 is a conventional land pattern diagram.

FIG. 6 is a diagram illustrating a conventional land pattern problem.

[Explanation of symbols]

 10 Base Material Layer 12 Via Hole 14 Conductor 16, 161 to 166, 181 Land Pattern

Claims (3)

[Claims] 1. A substrate layer (10) for connecting between layers.
A via hole (12) penetrating the conductor is filled with a conductor (14), and a thin conductor land pattern (16,
161 to 166) are applied as wiring patterns to the base material layer, the land patterns are basically rectangular, and when the rectangular corners of adjacent land patterns are close to each other,
A multi-layer printed circuit board having a land pattern in which both corners are cut off by a straight line. 2. A land pattern code (Ri) is represented by a land pattern common code (r), a land pattern detailed code (Ci), and a land pattern position coordinate (Pi), and a vector having the adjacent position coordinates as an end point. When (PiPj) satisfies the condition of the specific direction and the specific length, the land pattern detail code is a code of a rectangular shape in which the corners of the direction are cut off by straight lines, and when the condition is not satisfied, Is a rectangular code, and a land pattern corresponding to the land pattern detail code is assigned to layout-design the multilayer printed circuit board according to claim 1, 3. The detailed land pattern code (Ci)
First, all rectangular codes are given, and when the vector (PiPj) having the adjacent position coordinates as end points satisfies the condition of the specific direction and the specific length, the rectangular code of 3. The land pattern designing method according to claim 2, wherein the land pattern detail code (C) is generated by changing to a code in which the corners of the direction are cut off by a straight line.