JP2002334124A - Device and method for adjusting wiring width in printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for adjusting wiring width in a printed wiring board capable of automatically changing line width without relying on manpower. SOLUTION: When information regarding the line width by every net of printed wiring board patterns designed by CAD is read, stored, presence/absence of specification of the line width is judged regarding the respective nets. The specified line width is allocated if it is specified but reference line width is allocated if it is not specified. Then, the respective signal wirings 6 are connected to one another with the allocated line width, interference between the signal wiring 6 and a T/H land 5 is prevented and also a failure due to omission of returning of the line width is prevented, and whether or not a clearance is secured between the signal wiring 6 and the T/H land 5 is judged. When no clearance is secured, the line width is calculated according to a predetermined calculation formula and the signal wirings 6 are changed into the calculated line width in an area where a through hole is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring width adjusting device and a wiring width adjusting method for a printed wiring board, and more particularly to a wiring width adjusting method for a printed wiring board. The present invention relates to a wiring width adjusting apparatus and a wiring width adjusting method for inspecting interference and automatically adjusting a line width.

[0002]

2. Description of the Related Art Conventionally, in order to design a wiring pattern on a printed wiring board, a pattern is formed with a uniform line width for each net using CAD, and then the line width of signal wiring constituting the net is manually adjusted. Is used, but in recent years,
Due to the demand for higher density of printed wiring boards, it has become necessary for signal wiring of printed circuit boards to route signal wirings having different wiring widths to the same layer due to their functions, and adjustment of the line width has become important. I have.

[0003]

A multi-pin LS is used for signal wiring.
When drawing out from inside I, depending on the line width of the signal wiring, it may not be possible to pull out as it is. In such a case, the line width is manually selected, the inside of the LSI is wired with a narrow line width, and the LSI is drawn out. However, there was no method for automatically performing this work, and the work was manually performed. For this reason, a failure in the line width due to forgetting to return the line width occurred. In particular, when wiring signal wires having different wiring widths on the same layer, the work of adjusting the line width is complicated, and the above-mentioned problem is likely to occur.

[0004] The present invention has been made in view of the above-mentioned problems, and its main purpose is to rely on human hands.
It is an object of the present invention to provide a wiring width adjusting device and a wiring width adjusting method for a printed wiring board that can automatically change a line width.

[0005]

In order to achieve the above object, a wiring width adjusting apparatus according to the present invention comprises: means for reading information on a line width of each net of a printed wiring board pattern designed by CAD; Means for storing information in association with said nets, and for each said net,
Means for deciding whether or not a line width is specified, and allocating the specified line width as the first line width if specified, and a predetermined reference line width if not specified; When the respective signal wirings constituting the above are connected with the first line width, whether or not a predetermined space is secured between the signal wiring and a land of a through hole formed in the printed wiring board. Means for determining the second line width capable of securing the predetermined interval according to a predetermined calculation formula when the predetermined interval is not ensured; and
And a means for storing the line width in association with the net.

In the present invention, further, the signal wiring is changed to the second line width in a region where the through hole is formed in the printed wiring board, and the signal wiring is changed outside the region. It is preferable to have means for returning the wiring to the first line width.

Further, in the present invention, the line width of the signal wiring is w, the diameter of the land of the through hole is Δ, the distance between the lands of the through hole is d, and the signal wiring and the land of the through hole are different from each other. When the predetermined interval between the two is Δ, the line width w is set so as to satisfy w = d−ψ−2 × Δ.
Is preferably determined.

Further, the method for adjusting the wiring width according to the present invention is characterized in that
Reading information related to the line width of each net of the printed wiring board pattern designed in the step, storing the information related to the line width in association with the net, and determining whether the line width is specified for each of the nets. Allocating a designated line width as a first line width if specified, and a predetermined reference line width as a first line width if not specified, and assigning each signal wiring constituting the net Determining whether a predetermined space is secured between the signal wiring and a land of a through hole formed in the printed wiring board when wiring is performed with the first line width; Calculating a second line width capable of securing the predetermined interval according to a predetermined calculation formula when the interval is not ensured; and writing the second line width in association with the net. A step of those having at least.

As described above, according to the present invention, when a signal wiring having a specified line width is drawn from an LSI, if the line width cannot be drawn, wiring between PADs can be performed based on parameters for each net. Automatically calculates the width and calculates the LSI with the line width.
From the LSI and automatically return to the specified line width after going out of the LSI, so that the line width for each net is monitored by the program. Failures can be prevented.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a preferred embodiment of the method for adjusting a wiring width of a printed wiring board according to the present invention, in a preferred embodiment, information on a line width of each net of a printed wiring board pattern designed by CAD is read and stored. , Determine whether the line width is specified for each net,
When the designated line width is assigned, and when the designated line width is assigned, the reference line width is assigned. It is determined whether or not a clearance is secured between the H land and, when the clearance is not secured, a predetermined calculation formula, for example, the line width of the signal wiring is set to w, T / H
When the diameter of the land is ψ, the interval between the T / H lands is d, and the clearance between the signal wiring and the T / H lands is Δ, according to a calculation formula represented by w = d−ψ−2 × Δ By calculating the line width, the signal wiring is changed to the calculated line width in the area where the through hole is formed in the printed wiring board, and the line width is automatically returned outside the area, thereby obtaining the signal wiring. And the T / H land are prevented from interfering with each other, and a problem caused by forgetting to return the line width is prevented.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a printed wiring board according to an embodiment of the present invention; FIG. I will explain. FIG. 1 is a block diagram illustrating a basic configuration of a wiring width adjusting apparatus according to the present embodiment. FIGS. 2 and 3 are flowcharts illustrating a procedure of a wiring width adjusting method. 4 to 6 are plan views showing wiring states of the printed wiring board. FIG. 4 shows a state before wiring width adjustment, and FIG. 5 shows a state in which wiring interferes with the T / H land. FIG. 6 shows a state after the wiring width adjustment.

First, the basic configuration of the wiring width adjusting device of the present embodiment will be described with reference to FIG. 1. The wiring width adjusting device 1 reads parameter width means 2 for reading a line width parameter for each signal net. A signal line width setting means 4 for setting an optimum line width from parameters; and a memory 3 for storing the parameters read by the parameter reading means 2 and the optimum line width set by the signal line width setting means 4 in association with the net. It consists of.

The procedure for adjusting the line width using the wiring width adjusting apparatus having the above-described configuration will be described in detail with reference to the flowcharts shown in FIGS.

First, the procedure for reading the information for specifying the wiring width will be described with reference to FIG. In step S201, the parameter file is read using the parameter reading means 2 in order to read information of a net for which the wiring width is specified. This parameter has, for example, a format in which a net name and a line width are paired in one line. Next, in step S202, using the net name of the read parameter as a key, the corresponding line width value is fetched into a storage means such as the memory 3 as the characteristic condition of the net. Then, in step S203, the EOF is checked to determine whether the parameter file has been completed or is still continuing. When the EOF is detected, the reading of the parameters is terminated, and when the EOF is not detected, step S20 is performed.
Returning to step 1, the next parameter is read.

Next, the procedure of the wiring process will be described with reference to FIG. First, in step S301, a net to be wired is selected. The selection is made, for example, directly by using a pointing device on the screen, or by keyboard input. Next, step S301
The line width information of the net selected in is extracted. Then, it is determined whether or not the line width is specified in step S303. If the line width is specified, the process proceeds to step S304.
If no line width is specified, the process branches to step S309.
A predetermined reference line width is set.

The processing when there is a designated line width will be described below.

In step S304, the line width is set once to the designated line width or the reference line width, and a clearance check between the T / H lands provided on the printed wiring board and the signal wiring is performed. In step S305, an error determination is performed based on the result of the clearance check in step S304. If an error occurs (if the T / H land and the signal wiring interfere), the process proceeds to step S306. Proceeds to step S310.

If an error occurs in step S305,
Next, it is checked in step S306 whether the line width has been changed. Initially the line width has not changed, so
Proceeding to step S311, based on the T / H land spacing of the LSI and the clearance value of the T / H land-signal wiring,
/ H Calculates a line width that allows drawing between lands, and uses it as an alternative value. This value is stored in memory 3 in step S312.
Evacuated to

Next, in step S307, the line width is automatically given by referring to the value saved in the memory 3 in step S312 in order to assist the work of drawing the wiring. Then, in step S308, it is checked whether or not the connection of the selected net has been completed. If it has been completed, the process ends. If it has not been completed, the process returns to step S304.

On the other hand, if no error occurs even in the designated line width in step S305, the flow advances to step S310 to set the line width designated by the parameter.
At 308, it is checked whether the connection of the selected net is completed. If it has been completed, the process ends. If it has not been completed, the process returns to step S304.

Next, a procedure for setting the line width of the signal wiring using specific numerical values will be described with reference to FIGS. FIG. 4 shows a state before the line width adjustment processing according to the present embodiment, and shows an image in which wiring is drawn out. FIG.
It is an LSI package image, and shows an image in which signal wiring is drawn from a drawing target. FIG.
Shows a state after the line width adjustment processing of this embodiment.

Here, a wiring width of 0.6 mm is specified for the signal wiring 6, and the size of the T / H land 5 is φ0.7 mm.
From the manufacturing conditions, it is assumed that a minimum clearance of 0.1 mm must be provided between the T / H land 5 and the signal wiring 6. The interval between T / H lands 5 is 1.27.
The following description will be made on the basis of mm.

The T / H land 5 has a pattern prohibited area 10
Is set around the land, and whether or not the prohibited area 10 interferes is checked. When the drawing is performed with the specified line width from the drawing target 8 with the above dimensions, before the wiring is completely drawn out with the specified line width, the signal wiring 6 is moved to the prohibited area 10 of the T / H land 5 as shown in FIG. Will interfere.

Therefore, a line width for extracting a target without causing interference is determined by the following method. First, the distance is obtained from the coordinate value of the draw-out target 8 and the coordinate value of the T / H land 5 causing the interference. For example, if the coordinate value (X1, Y1) of the target 8 is (15 mm, 15 mm) and the coordinate value (X2, Y2) of the interfering T / H land 5 is (15 mm, 16.27 mm), the difference is obtained. It can be calculated from the absolute value of that the land interval is 1.27 mm.

As for the wiring width, land spacing,
It can be obtained from the land diameter and the manufacturing clearance value by the equation (1).

Line width = land interval−land diameter−clearance value × 2 (1)

In the case of FIG. 4, 1.27-0.7
A line width of −0.1 × 2 = 0.37 mm is required.
Using the line width obtained here, the signal wiring 6 is drawn out with this value until a clearance error does not occur in drawing out from the LSI.

The clearance error is checked on the basis of the value specified by the parameter. When the clearance error disappears, the line width is returned to the line width specified by the parameter, and the wiring outside the LSI is specified by the specified line width. The pattern is drawn with. When the line width of the lead wiring is corrected by the above method, a wiring pattern as shown in FIG. 6 is formed.

As described above, according to the wiring width adjusting apparatus and the wiring width adjusting method of the present embodiment, the wiring width of the signal wiring 6 causing interference with the T / H land 5 is determined by a predetermined method. By automatically setting the wiring width inside the LSI package with the wiring width and returning the wiring width to the set value at the stage of leaving the LSI package, only the wiring width of the interference part is automatically adjusted without manual operation can do.

[0030]

As described above, according to the wiring width adjusting apparatus and the wiring width adjusting method of the present invention, there is no need to manually switch the line width when drawing out from the LSI, and wiring is performed while keeping the specified line width. be able to.

The reason is that since the line width is monitored by the program, the line width can be automatically adjusted to the optimum line width.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a line width adjustment device for signal wiring in a printed wiring board according to one embodiment of the present invention.

FIG. 2 is a flowchart illustrating a procedure for reading wiring width designation information in the signal wiring line width adjustment method according to one embodiment of the present invention.

FIG. 3 is a flowchart illustrating a procedure of a wiring process in a method of adjusting a line width of a signal wiring according to an embodiment of the present invention.

FIG. 4 is an LSI wiring diagram before performing a process by a line width adjusting method according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a state where a signal wiring interferes with an edge of a T / H land.

FIG. 6 is an LSI wiring diagram after performing processing by a line width adjusting method according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Signal line width adjustment device 2 Parameter reading means 3 Memory 4 Signal line width setting means 5 T / H land 6 Signal wiring 7 LSI package 8 Pull out target 9 Clearance error occurrence place 10 Prohibited area 11 Clearance error avoidance place

Claims (6)

[Claims] A means for reading information relating to a line width of each net of a printed wiring board pattern designed by CAD; a means for storing the information relating to the line width in association with the net; It is determined whether or not is specified, and if specified, the specified line width is set. If not specified, the predetermined reference line width is set to the first line width.
Means for allocating as a line width, and when each signal wiring constituting the net is connected with the first line width, between the signal wiring and a land of a through hole formed in the printed wiring board. Means for determining whether or not a predetermined interval is secured; and means for calculating a second line width capable of securing the predetermined interval according to a predetermined calculation formula when the predetermined interval is not secured. At least means for storing the second line width in association with the net. 2. The method according to claim 1, further comprising: changing a width of the signal wiring to the second line width in a region where the through hole is formed in the printed wiring board; 2. The apparatus according to claim 1, further comprising means for returning the line width to the first line width. 3. The line width of the signal wiring, w the diameter of the land of the through hole, d the spacing between the lands of the through hole, and the predetermined distance between the signal wiring and the land of the through hole. The line width w is determined so as to satisfy w = d−ψ−2 × Δ, where Δ is an interval of Δ, and the wiring width adjusting device for a printed wiring board according to claim 1 or 2, wherein . 4. A step of reading information on a line width of each net of a printed wiring board pattern designed by CAD,
Storing information on the line width in association with the net; and determining whether a line width is specified for each of the nets. If the line width is specified, the specified line width is specified. If not, allocating a predetermined reference line width as a first line width; and, when connecting each signal line constituting the net with the first line width, the signal line and the printed wiring board are connected. Determining whether or not a predetermined interval is secured between the land of the through hole formed in the step; and securing the predetermined interval according to a predetermined calculation formula when the predetermined interval is not secured. Calculating a possible second line width; and storing the second line width in association with the net, wherein the line width is adjusted in a printed wiring board. Law. 5. In the printed wiring board, the signal wiring is changed to the second line width in a region where the through hole is formed, and the signal wiring is changed to the first line outside the region. 5. The method for adjusting a wiring width in a printed wiring board according to claim 4, wherein the wiring width is returned to the above. 6. The line width of the signal wiring is w, the diameter of the land of the through hole is ψ, the distance between the lands of the through hole is d, and the predetermined distance between the signal wiring and the land of the through hole is 6. The wiring width adjustment method for a printed wiring board according to claim 4, wherein the line width w is calculated so as to satisfy w = d−ψ−2 × Δ, where Δ is an interval.