JPH04302059A - Printed circuit board designing device - Google Patents

Abstract

PURPOSE:To generate an optimal pattern by providing an automatic unused part pin pad reduction processing part, automatic pattern connecting part pin pad reduction processing part, and CAD data base. CONSTITUTION:An unused part pin is detected, and the pad size of the unused pin is automatically reduced by an automatic unused part pin pad reduction processing part 5, by referring to both a symbol library 3 and a network list 4 generally. On the other hand, the pad size of entire signal levels except for the level connected at the time of connection is automatically reduced by an automatic pattern connecting part pin pad reducing part 6. Then, the automatically reduced data are stored in a CAD data base 7. Thus, the optimal pattern can be generated by automatically reducing the pad size of the unnecessary pin.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board design apparatus using CAD, and more particularly to an improvement in the function of automatically reducing the size of unnecessary pin pads.

0002

[Prior Art] A printed circuit board design device that designs printed circuit boards using CAD uses a symbol library that defines detailed data of each package and shape symbol, and a data group that generally defines package shape symbols that realize each part. It has a netlist that describes a data group that defines connections between each component pin.

[0003] This type of CAD-based printed circuit board design apparatus usually reads a file called a netlist, refers to component definition data described therein, and constructs CAD data for layout. Note that the actual data of the package shape symbol described in the component definition data defines the pad size, etc. on the assumption that all pins are used.

FIG. 11 is an explanatory diagram conceptually showing the relationship between a symbol library and a netlist. Figure 11(a)
shows an example of a symbol library for the package shape and symbol of a component called DIP014, and FIG. 11(b) shows the contents of the corresponding netlist.

[0005]Currently, even unconnected pins are made with the same pad size as the connecting pins. Furthermore, when a connection pin was specifically connected to a pattern, all signal levels other than the level connected to the pattern were created using the same pad size as when creating the symbol.

[0006]

[Problem to be Solved by the Invention] Originally, when it is considered that the pad size of the pad of an unconnected pin is sufficient for an insertion type component, the component lead diameter + α (for example, α = 0.2 mm), The same pad size as the pin (for example, if the component lead diameter = 0.6 mm, the pad size is 1
．． 4 mm), the unused pin pad becomes an obstacle, causing problems such as having to draw the pattern in a detour.

Furthermore, even when a connection pin is connected to a pattern, the pad sizes of all other signal levels remain unchanged, which poses an obstacle when drawing a pattern.

The present invention has been made with attention to these points, and its purpose is to provide a printed circuit board design device that can automatically reduce the pad size of unnecessary pins and create an optimal pattern. Our goal is to provide the following.

[0009]

[Means for Solving the Problems] The present invention solves the above problems by providing a symbol library that defines detailed data of each package and shape symbol, a data group that defines package shape symbols that realize each part, and each In a printed circuit board design device that has a netlist that describes a data group that defines connections between component pins and designs printed circuit boards using CAD, unused component pins are detected by referring to the symbol library and the netlist. There is also an unused component pin pad automatic reduction processing unit that automatically reduces the pad size of unused component pins, and a pattern connection component pin pad automatic reduction processing unit that automatically reduces the pad size of all signal levels other than the level where a connection is made during wiring. The present invention is characterized in that it includes a processing section and a CAD database that stores CAD data that has been automatically reduced.

0010

In the present invention, the unused component pin pad automatic reduction processing section refers to the symbol library and generally the netlist, detects unused component pins, and automatically reduces the pad size of the unused component pins. On the other hand, the pattern connection component pin pad automatic reduction processing section automatically reduces the pad size of all signal levels other than the level where connection is made during wiring. The automatically reduced data is then stored in the CAD database.

[0011]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram showing the configuration of functional blocks of a system implementing an embodiment of the present invention. First, each function and configuration will be briefly explained with reference to FIGS. 1 and 2.

Edit console 1: Consists of input devices such as a keyboard and mouse, and input is performed by the operator.

Control unit 2: Controls the various units of the apparatus of this embodiment in an integrated manner, and also performs processing for pattern creation of printed circuit boards.

Symbol library 3: This is a file in which the shape of each package and detailed symbol data (for example, silk diagram, component pin data, pad size at each level of each pin data, etc.) are defined.

Netlist 4: A file in which the package shape and symbols (names) for realizing each component are defined. However, although this file is optional data, the explanation will be based on the assumption that it exists.

Unused component pin pad automatic reduction processing unit 5:
Referring to symbol library 3 and netlist 4,
Detect unused component pins. Then, as shown in FIGS. 2 and 2, the pad size of unused component pins is automatically reduced.

Pattern connection component pin pad automatic reduction processing section 6: Automatically reduces the pad size of all signal levels other than the level where the connection is made (■ on the component surface level in FIG. 2) during manual or automatic wiring.

CAD database 7: This is a database composed of printed circuit board patterns that have been subjected to the above-mentioned automatic reduction process.

CRT8: Displays the created printed circuit board pattern on the screen.

Next, the overall operation of the apparatus of this embodiment will be explained by case. <Unused component pin pad automatic reduction process> First, the control unit 2
reads component definition data 4a and connection definition data 4b in netlist 4 (step 1).

[0022] Regarding the package shape and symbol name defined in the read component definition data 4a,
The detailed data is read from the symbol library 3. Here, the control unit 3 detects all component pins related to the component whose data has been read. This operation is executed for all parts (step 2).

The component pins (numbers) used for each component are detected from the connection definition data 4b in the netlist 4 (step 3).

[0024] Find the difference between the total component pins (numbers) for each component obtained in step 2 above and the used component pins (numbers) obtained in step 3 above, and divide unused component pins for each component. to be detected. The data of this unused component pin is then saved (step 4).

[0025] Construction of CAD database ■ (For parts without unused part pins); In the IC (DIP014) whose symbol shape data on the symbol library is as shown in FIG.
Internal import type data is created on the D database (step 5-1). That is, this is a method in which symbol shape data is brought inside and the display is performed by referring to the internal shape data.

As for how to hold symbol shape data in the internal import type, there is an expanded type shown in FIG. 4 (a type in which the component pin position for each component and the pad size of each level for each component pin can be set). , the macro type shown in Figure 5 (when the symbol shape is the same, all component pin positions and pad sizes at each level for each pin are fixed. Customization for each component is not possible), as shown in Figure 6. There is a combination type (type of combination of expansion type and macro type) shown below. In this proposal, there is no particular problem as long as the database allows automatic reduction of component pin pads. Here, it is assumed that a CAD database is constructed using an expanded type.

In addition to the internal import type, there is also an external reference type shown in FIG. This does not have symbol shape data internally (Figure 7 (a), (b)), but only the name of the symbol, and for example, when displaying, it refers to the symbol library (Figure 7 (c)) and displays it. This is a method to do so.

There is also a combination type of external reference type and internal import type. Details of this combined type data will be omitted.

Incidentally, FIG. 8 is a diagram showing an example in which the control section 2 refers to the CAD database 7 to display parts on the CRT 8.

Construction of CAD database ■ (For parts with unused part pins); For an IC (DIP014) whose symbol shape data on the symbol library is as shown in
Internal import type data is created on the D database (step 5-2). That is, an internal import type CAD database is constructed using the expansion type shown in FIG. At this time, since the data is exactly the same as the data in the symbol library, the pad sizes of all component pins are the same. Next, pad data is set in which the pad size of unused component pins is reduced at all signal levels.

Methods for setting pad data on component pins at each level can be roughly divided into a skewer type and an individual setting type. In this embodiment, any setting method may be adopted.

For reference, FIG. 9 shows an explanatory diagram of the skewer type setting. In a multilayer board like FIG. 9(a), each level (each layer) of the multilayer board is shown in FIG. 9(b).
Each pad size is arranged in one code (for example, pad code 1 is pad size 0.8 mm, pad code 2 is
means a pad size of 1.4 mm),
This code is given as an attribute of each component pin.

In the individual setting type, each component pin has all levels, and each pad size is assigned to each level.

Next, the operation of the pattern connection component pin pad automatic reduction process of the apparatus of this embodiment will be explained in different cases. <Pattern connection component pin pad automatic reduction processing> When a certain component pin is connected at level n by manual or automatic processing, pads with signal levels other than level n are removed from the unused component pin pad automatic reduction processing described above in operation step 5-2.
Automatically reduce the size using the same procedure as .

[0035] When deleting a pattern,
The pad size of the deleted level will be automatically reduced. Furthermore, when a new connection is made to a pin whose pads have been automatically reduced as unused component pins at all signal levels, pads other than those at the level where the connection was made are returned to their normal pad sizes before being automatically reduced.

In the case of a through hole, as shown in FIG. 10, only the level where the pattern enters and the level where the pattern exits have the normal pad size, and the other areas are defined as reduced pads.

As explained in detail above, the pad size of unused component pins is automatically reduced at all signal levels during the initial configuration of the CAD database, and the pad size is automatically reduced at all signal levels other than the level where connections are made during wiring work. The automatic pad size reduction increases the effective wiring area on the printed circuit board, contributing to increased wiring work efficiency.

Furthermore, printed circuit boards are becoming more dense and multi-layered. In particular, in the case of multi-layering, the pad size of the inner layer signal level is generally set larger than that of the outer layer in consideration of errors in overlaying when creating an actual board, so this is particularly effective. Furthermore, for component pins with connections, the pads are reduced for all signal levels except for one level, so the effect is even greater.

Although the current printed circuit board wiring work achieves an automatic wiring function through digital processing, complete automation is difficult, and the remaining portions are wired manually. In particular, manual work requires a large amount of man-hours,
This is a big problem in terms of work efficiency. This problem,
In the case of multilayer boards, increasing the number of levels did not significantly improve wiring efficiency. Such a problem can be solved by the proposal of this embodiment.

In the above explanation, ``a symbol library that defines detailed data of each package and shape symbol, a data group that defines the package shape symbol that realizes each part, and a data group that defines the connection between each component pin are described. It is assumed that a netlist exists. However, as explained in this proposal, the key point is to automatically reduce the pads of component pins connected to the pattern, so there is no need for a so-called netlist. Printed board C
In AD, it is common to have a netlist, and this is assumed for convenience of explanation. Note that if a netlist is available, there is an advantage that the pad size of unused component pins can be reduced in advance.

[0041]

As described above in detail, according to the present invention, it is possible to realize a printed circuit board design apparatus that can automatically reduce the pad size of unnecessary pins and create an optimal pattern.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing the overall configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing how the pad size is reduced at the component surface level and the solder surface level.

FIG. 3 is a configuration diagram showing the state of symbol shape data on a symbol library.

FIG. 4 is an explanatory diagram showing expanded symbol shape data.

FIG. 5 is an explanatory diagram showing macro-type symbol shape data.

FIG. 6 is an explanatory diagram showing combination-type symbol shape data.

FIG. 7 is an explanatory diagram showing external reference type symbol shape data.

FIG. 8 is an explanatory diagram showing a display state of CAD data according to an embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a state of creating CAD data according to an embodiment of the present invention.

FIG. 10 is an explanatory diagram showing a state of creating CAD data according to an embodiment of the present invention.

FIG. 11 is an explanatory diagram showing the relationship between a symbol library and a netlist.

[Explanation of symbols]

1 Edit console 2 Control section 3 Symbol library 4 Netlist 5 Unused component pin pad automatic reduction processing section 6 Pattern connected component pin pad automatic reduction processing section 7 CAD database 8 CRT

Claims (1)

[Claims] [Claim 1] A symbol library that defines detailed data of each package and shape symbol, a data group that defines the package shape symbol that realizes each part, and a data group that defines the connections between the pins of each component are described. In a printed circuit board design device that has a netlist and designs printed circuit boards using CAD, the symbol library and the netlist are referenced, unused component pins are detected, and the pad size of the unused component pins is automatically reduced. Unused component pin pad automatic reduction processing section, pattern connection component pin pad automatic reduction processing section that automatically reduces the pad size of all signal levels other than the level where connection is made during wiring, and stores the automatically reduced CAD data. A printed circuit board design device comprising a CAD database.