JPH11312184A - Cad system and method for preparing teardrop - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a CAD system, capable of automatically preparing suitable teardrops, for securing a distance from a nearby conductor by using a taper pattern. SOLUTION: A teardrop automatic generation part 121 arranges a virtual via hole or a pad, of which diameter is equal to the width of a signal line connected to a via hole or a pad on the signal line and prepares a taper pattern for wiring-connecting between the arranged virtual via hole or PAD and the real via hole or pad connected to the signal line. Consequently, a teardrop for enhancing the reliability of contacts between the via holes or a pad and a signal line is prepared properly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a CAD system for supporting the design of a printed wiring board, and more particularly to a VIA.
The present invention relates to a CAD system that forms a teardrop at a contact point between a hole or a PAD and a signal line.

[0002]

2. Description of the Related Art In a printed wiring board, in order to increase the reliability of a contact between a VIA hole or a PAD and a signal line, it is usual to provide a tear drop which is widened from the signal line side toward the VIA hole or the PAD side. It is. However, with the recent increase in the density of printed wiring boards, it has become difficult to arrange teardrops while maintaining the distance from neighboring conductors.

[0003] For this reason, for example, as shown in FIG. 7, when the distance between the teardrop (a) created for ensuring reliability and the neighboring conductor (b) cannot be secured more than a predetermined distance (G). By removing a part of the teardrop (a), an interval between the adjacent conductor (b) and the predetermined distance (G) is ensured.

However, in such a method, for example, as shown in FIG.
If there is, tear off the teardrop (a),
The original effect of teardrop may be lost.

Therefore, a plurality of teardrops are prepared for each pattern and used depending on the situation. However, a certain amount of experience and knowledge to select an appropriate teardrop are provided to the user. Since the teardrop was created at the manufacturing stage in the first place, it could not be confirmed on the CAD system.

[0006]

As described above, in recent years, as the density of printed wiring boards has increased, teardrops for improving the reliability of contacts between VIA holes or PADs and signal lines have been arranged. In some cases, the method of securing the gap between neighboring conductors by deleting a part of the teardrop that was conceived to cope with this problem may lose the original effect of the teardrop in some cases. Was gone.

[0007] For this reason, a plurality of teardrops having different shapes have been prepared for each pattern and used depending on the situation. There is a problem that the user is required to have knowledge and cannot be confirmed on the CAD system.

The present invention has been made in view of such circumstances, and a distance from a neighboring conductor is ensured by using a tapered pattern for connecting two VIA holes or PADs having different diameters to each other. It is an object of the present invention to provide a CAD system capable of automatically creating an appropriate teardrop and a teardrop creation method applied to the CAD system.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a CAD system for supporting the design of a printed wiring board, comprising:
In a CAD system for forming a teardrop at a contact point between an A hole or a PAD and a signal line, a taper pattern creating means for creating a taper pattern for wiring connection between two VIA holes or PADs having different diameters, and a VIA hole or a PAD. A virtual VIA hole or PAD having a diameter equal to the width of the signal line is arranged on the signal line connected to the VIA, and the VIA connecting the signal line to the taper pattern forming means.
Hole or PAD and the virtual VIA hole or P
And a teardrop creating means for creating a taper pattern for wiring connection with the AD.

In the present invention, the VIA hole or PA
A virtual VIA hole or PAD having a diameter equal to the signal line width is arranged on the signal line connected to D, and a space between the arranged virtual VIA hole or PAD and the VIA hole or PAD to which the signal line is connected is provided. By creating a taper pattern for wiring connection, it is possible to create a teardrop on a CAD system.

Further, according to the present invention, the teardrop creating means may be configured so that the virtual V is selected according to a positional relationship with a neighboring conductor.
It is characterized in that it has a means for determining the arrangement coordinates of the IA hole or the PAD.

In the present invention, a teardrop having a shape corresponding to the positional relationship with the neighboring conductor is created, so that an appropriate teardrop can be created without asking the user's experience and knowledge. Since there is no need to prepare a plurality of teardrops for each pattern, there is no increase in graphic element data.

Further, the present invention is characterized in that when the tear drop creating means cannot create a taper pattern based on a positional relationship with a neighboring conductor, the tear drop creating means has means for notifying the user of the fact.

According to the present invention, the user can be informed of a point where the distance from the neighboring conductor cannot be ensured by a predetermined distance or more, so that an opportunity can be given to take some measures before the process shifts to the manufacturing stage. .

Further, the present invention is characterized in that the teardrop creating means has means for requesting movement of the neighboring conductor when a taper pattern cannot be created due to the positional relationship with the neighboring conductor. .

According to the present invention, for example, when the CAD system has a so-called push-out function of moving a low-priority component or a wiring element as needed when arranging a high-priority component or a wiring element, the tear drop is performed. By using high-priority wiring elements, it is possible to always ensure a predetermined distance or more between adjacent conductors.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a computer system on which a CAD system according to an embodiment of the present invention operates.

As shown in FIG. 1, a computer system according to this embodiment includes a CPU 11, a system memory 12,
An input unit 13, a display unit 14, and a database 15 are provided.

The CPU 11 controls execution of application programs including an operating system and utilities stored in the system memory 12. The system memory 12 is a memory device that stores an application program including an operating system and a utility controlled by the CPU 11 and various data used for executing the application programs.

The input unit 13 is, for example, a keyboard, a mouse, or the like, and is a device for inputting a user instruction or the like into the system. The display unit 14 is, for example, a CR
It is a T display or the like, and is a device for presenting a processing result or the like to a user.

The database 15 stores various data including graphic element data relating to parts, wiring elements, and the like. In addition, the CAD system of this embodiment has a VI
It has a teardrop automatic creation unit 121 for creating a teardrop using a taper pattern for improving the reliability of the contact point between the A-hole or the PAD and the signal line. 12 and is configured as an application program whose execution is controlled by the CPU 11.

The creation of a teardrop using a taper pattern by the automatic teardrop creation unit 121 will be described below. First, the concept of the taper pattern will be described. FIG. 2 is a conceptual diagram illustrating a tapered pattern. As shown in FIG. 2, the tapered pattern is a wiring connecting two VIA holes or PADs having different diameters arranged at coordinates 1 and 2.

Next, an outline of how to create a teardrop using this taper pattern will be described. FIG. 3 is a conceptual diagram illustrating the creation of a teardrop using a taper pattern. As shown in FIG. 3, the teardrop automatic creation unit 121
A virtual VIA hole or PAD having a diameter equal to the signal line width on a signal line (e) connected to the hole or PAD (d).
(D '), and place this virtual VIA hole or PAD
(D ') and VIA hole or P to connect signal line (e)
A tear drop is created by creating a taper pattern for wiring connection with AD (d) while securing an interval of at least a predetermined distance (G) from the neighboring conductor (b).

Here, the operation procedure of the automatic teardrop creation unit 121 will be described with reference to FIG. FIG. 4 is a flowchart illustrating an operation procedure of a teardrop creating process using a taper pattern by the teardrop automatic creating unit 121.

First, the teardrop automatic creation unit 121 receives, as one of the CAD data, the input of the maximum value and the maximum inclination angle of the teardrop to be created (step S1). Also, teardrop automatic creation unit 1
21 is a VIA hole or PAD where a teardrop should be created
Is set in the tear drop generation target table in the database 15 as data on the detected VIA holes and PADs and data on the signal lines connected thereto (step S2).

When the setting of the target data in the tear drop generation target table is completed, the tear drop automatic creation unit 121 sequentially stores the target data relating to the VIA hole or the PAD and the signal line connected thereto from the tear drop generation target table. Take it out (step S3).

Next, the teardrop automatic creation unit 121
For example, as shown in FIG. 5, the first line segment is included in VIA or PAD, or VI
A line segment whose proper inclination to A or PAD is equal to or less than the maximum angle is set as a teardrop generation target line segment (step S4).

Here, the teardrop automatic creation unit 121
Retrieves the data on this VIA or PIA neighbor conductor from the database 15 and, as shown in FIG.
An appropriate inclination of both end lines of the teardrop is calculated (step S5).

When the calculated appropriate inclination is larger than the maximum inclination angle (YES in step S6), the automatic teardrop creating unit 121 sets the information on this VIA or PAD in the unoccurred teardrop table in the database 15. (Step S7).

On the other hand, if the calculated proper inclination is smaller than the maximum inclination angle (NO in step S6), the teardrop automatic creation unit 121 calculates the coordinates of the virtual VIA or PAD to be arranged on the signal line based on the appropriate inclination. That is, the length of the teardrop to be created is determined, and the teardrop is generated using the taper pattern (step S
8).

Thereafter, the teardrop automatic creation unit 121
Determines whether the extraction of all target data relating to the VIA hole or PAD and the signal line connected thereto from the tear drop generation target table has been completed (step S
9) If not completed (N in step S9)
O), repeat the processing from step S3.

On the other hand, if the processing has been completed (YES in step S9), the teardrop automatic creation unit 121 outputs the unoccurred teardrop information set in the unoccurred teardrop table (step S10).

As described above, in the CAD system of this embodiment, it is possible to create a teardrop on a CAD system, such as creating a teardrop using a taper pattern.

For example, when the CAD system has a so-called push-out function of moving a low-priority component or a wiring element as needed when arranging a high-priority component or a wiring element, the tear drop is set to a high priority. It is also effective to move neighboring conductors arranged at intervals smaller than a predetermined distance by using the wiring element of the above.

[0035]

As described above in detail, according to the present invention, a virtual VIA hole or PAD having a diameter equal to the signal line width is arranged on a signal line connected to the VIA hole or PAD, and this arrangement is made. By creating a taper pattern for wiring connection between a virtual VIA hole or PAD and a VIA hole or PAD to which a signal line is connected, it is possible to create a teardrop on a CAD system.

Further, since teardrops having a shape corresponding to the positional relationship with neighboring conductors are created, an appropriate teardrop can be created without asking the user's experience and knowledge. Since there is no need to prepare a teardrop having the shape shown in FIG.

Further, since it is possible to point out to the user a place where the distance from the neighboring conductor cannot be ensured to be equal to or more than a predetermined distance, it is possible to give an opportunity to take some measure before shifting to the manufacturing stage.

Further, for example, when the CAD system has a so-called pushing-out function of moving a low-priority component or a wiring element as needed when arranging a high-priority component or a wiring element, this teardrop is given a high priority. By setting the number of wiring elements, it is possible to always ensure the distance from the neighboring conductor to a predetermined distance or more.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a computer system on which a CAD system according to an embodiment of the present invention operates.

FIG. 2 is a conceptual diagram for explaining a taper pattern.

FIG. 3 is a conceptual diagram for explaining creation of a teardrop using the taper pattern of the embodiment.

FIG. 4 is an exemplary flowchart for explaining an operation procedure of a teardrop creating process using a taper pattern by the teardrop automatic creating unit of the embodiment.

FIG. 5 is an exemplary view showing a VIA or PAD including a first line segment according to the embodiment;

FIG. 6 is a view showing an example of an appropriate inclination of both end lines of the teardrop of the embodiment.

FIG. 7 is a diagram for explaining a conventional technique of removing a part of a teardrop to secure an interval with a neighboring conductor.

FIG. 8 is a diagram for explaining a problem of a conventional technique for securing a space between adjacent conductors by deleting a part of a teardrop.

[Explanation of symbols]

 11 ... CPU 12 ... System memory 13 ... Input unit 14 ... Display unit 15 ... Database 121 ... Tear drop automatic generation unit a ... Tear drop b ... Neighbor conductor c ... Taper pattern d ... VIA or PAD e ... Signal line

Claims (5)

[Claims] 1. A CA supporting design of a printed wiring board
A taper pattern creating means for creating a taper pattern for interconnecting two VIA holes or PADs having different diameters from each other in a CAD system for forming a teardrop at a contact point between a VIA hole or a PAD and a signal line. A virtual VIA hole or PAD having a diameter equal to the signal line width is arranged on a signal line connected to the VIA hole or PAD, and the VIA hole or PAD to which the signal line is connected to the taper pattern forming means is provided. Virtual VIA placed
A CAD system comprising: a teardrop creating means for creating a tapered pattern for wiring connection between a hole or a PAD. 2. The method according to claim 1, wherein the teardrop creating unit is configured to execute the virtual via hole or the PA according to a positional relationship with a neighboring conductor.
2. The CAD system according to claim 1, further comprising means for determining the arrangement coordinates of D. 3. The teardrop creating means according to claim 1, further comprising means for notifying a user when a taper pattern cannot be created due to a positional relationship with a neighboring conductor. The described CAD system. 4. The apparatus according to claim 1, wherein the teardrop creating means has means for moving the neighboring conductor when a taper pattern cannot be created due to a positional relationship with the neighboring conductor. CAD system. 5. A CAD system for supporting the design of a printed wiring board, comprising a taper pattern creating means for creating a taper pattern for interconnecting two VIA holes or PADs having different diameters from each other.
CA that forms a teardrop at the contact point between AD and signal line
A teardrop creating method applied to a D system, wherein a virtual VIA hole or a PAD having a diameter equal to the signal line width is arranged on a signal line connected to a VIA hole or a PAD, and The VIA hole or PAD to which the signal line is connected and the virtual VIA arranged above
A method for creating a teardrop, comprising creating a taper pattern for wiring connection between a hole or a PAD.