JP4550010B2 - Printed circuit board CAD system and footprint generation method in the same system - Google Patents

Description

  The present invention relates to a printed circuit board CAD system for generating a footprint indicating a conductor pattern of a pad provided for attaching an electronic component to a printed circuit board, and a footprint generating method in the system.

Usually, in order to manufacture a printed circuit board, hole information and information on a film for resist printing, printing silk screen, and copper foil etching are required.
In a printed circuit board CAD (Computer Aided Design) system, such information is stored in a form having a specific shape (hereinafter referred to as an object) on a layer concept (hereinafter referred to as a layer) in CAD data. In addition, when there is a change in processing steps or a change in manufacturing specifications, this is dealt with by switching the above-described layers.

For example, even when a hole is opened in one place on a printed circuit board, a hole shape whose shape is changed exists in a plurality of layers in CAD data. Layers with multiple specifications like this are stored in a storage device in a structure that is skewered for each object, and it corresponds to process changes and specification changes by specifying and outputting the required layers according to each manufacturing specification .
For this reason, the layers used for the footprint of the printed circuit board CAD are required to have a large number of layers so as to have versatility, and therefore, a large amount of labor is required for data input. In addition, the shape of the objects that make up the footprint includes solder lands and resist shapes that are directly linked to the mounting performance, and is calculated by complex calculation formulas that correspond to the manufacturing conditions. Since it has become know-how, it has been difficult to generalize.

On the other hand, in order to streamline the creation of electronic components, a shape definition that allows parameter input for a footprint pad stack having a complex shape is defined in advance, and numerical input for each parameter is performed on the screen according to certain rules according to this definition. There is known an electric CAD library registration method for performing padding and drawing a pad stack (see, for example, Patent Document 1).
Also, by seamlessly linking machine CAD with spreadsheet software, and having enough CAD model description capability, spreadsheet software can be used flexibly even when the shape of parts is unknown or the combination of parts changes. There is also known a CAD system capable of performing various countermeasures and capable of cooperating with spreadsheet software that allows a user to perform comfortable operations (see, for example, Patent Document 2).

JP 2001-325314 A (paragraphs “0006” to “0007”, FIG. 1) JP 2001-52037 A (paragraphs “0015” to “0022”, FIG. 3)

However, according to the technique disclosed in Patent Document 1 described above, it is difficult to formulate a footprint pad stack even if drawing, registration, and search are facilitated because design rules are various. Even when parts are serialized, it is necessary to create a part model by calculating the shape of the part from the basic specifications according to the design rules.
Further, according to the technique disclosed in Patent Document 2, although flexibility is enhanced by using user-customized spreadsheet software, a part model corresponding to specifications and machining processes is selected and configured in the spreadsheet. However, it is not possible to create a footprint or internal object having a layer structure that is secondarily calculated from the part shape. Furthermore, when CAD data of electronic parts and dimensional parameters of electronic parts are already stored in a database, no special effect can be obtained. In any case, the printed circuit board CAD component is related to the shape and arrangement coordinates based on a certain rule for each layer, and the calculation rule is composed of know-how unique to each company. It was difficult to automate.

  The present invention has been made in order to solve the above-described problems. A printed circuit board CAD system capable of automatically generating a footprint or an object having a layer configuration freely using user know-how, and An object is to obtain a footprint generation method in the same system.

The printed circuit board CAD system according to the present invention defines a shape that allows parameter input for a pad stack constituting a footprint, and obtains input data for each parameter in accordance with the shape definition, and an object from the input data A first arithmetic unit that generates a layer configuration customized based on a predetermined design rule and a superposition coordinate of the object, and the data acquisition unit. A link interface unit that acquires input data acquired through the first calculation unit and a superimposition coordinate of the object of the electronic component generated by the first calculation unit, and passes to the second calculation unit; Based on the input data and the overlay coordinates of the object, the pads The click by laying the mounting terminals coordinates of the electronic component and a second arithmetic unit for generating the footprint, based on input data obtained through the data acquisition unit, the electronic components for each layer Generates a customized layer configuration and shape data based on a predetermined design rule from a pad stack layer configuration table in which dimensions and attributes for specifying the object shape are defined in advance, and links to the pad stack layer configuration table from an object coordinate calculation table defined with even the in is supplied to the linkage interface unit generates the coordinate and attribute data overlay the object by the spreadsheet.

  According to the footprint generation method in the printed circuit board CAD system according to the present invention, the arithmetic processing device configuring the printed circuit board CAD system performs shape definition that allows parameter input for the pad stack configuring the footprint, and data for each parameter according to the shape definition A step of acquiring an input from an input device or a storage device, and a pad for which dimensions and attributes for specifying an object shape of the electronic component are defined for each layer and stored in advance in the storage device based on the acquired data input A step of generating a layer configuration and shape data customized based on a predetermined design rule from a stack layer configuration table based on a predetermined design rule, a link layer definition table linked to the pad stack layer configuration table, and pre-stored in the storage device Calculated object coordinates From the step of repeatedly generating the overlay coordinates and attribute data of the object by a number of times based on the layer configuration by spreadsheet, generating the pad stack with the overlay coordinates of each object, Laying out on the mounting terminal coordinates of the electronic component and generating and outputting a footprint.

  According to the present invention, the shape definition parameters are acquired, and the layer configuration and shape data customized based on a predetermined design rule are calculated from the pad stack layer configuration table based on a predetermined design rule, and the object overlay is superimposed from the object coordinate calculation table. By generating coordinates and attribute data and generating a pad stack, laying out the pad stack on the mounting component coordinates of the electronic component and generating and outputting the footprint, the footprint and internal objects with layer structure can be created by the user. It can be automatically generated freely using know-how.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a hardware configuration of a printed circuit board CAD system according to Embodiment 1 of the present invention.
The printed circuit board CAD system shown in FIG. 1 uses the arithmetic processing unit 1 as a control center, and the arithmetic processing unit 1 includes an input / output device 2, a main storage device 3, and external storage devices 4 and 5. The lines for address and data control are connected and configured in common via a system bus composed of a plurality of lines. For example, basic software such as Windows (registered trademark) of Microsoft Corporation resides in the main storage device 3, and spreadsheet software and printed circuit board CAD software, which will be described later, are stored. The arithmetic processing unit 1 sequentially reads and executes these software (programs) to generate electronic component data to be mounted on the printed circuit board. This includes footprint data intended by the present invention.

If the internal configuration of the arithmetic and control unit 1 is expressed in terms of function, it comprises a data acquisition unit 11, a first arithmetic unit 12, a second arithmetic unit 13, and a linkage interface unit 14.
The data acquisition unit 11 has a function of defining a shape in which parameters can be input for the pad stack constituting the footprint, and acquiring input data for each parameter according to the shape definition. Specifically, it corresponds to a parameter from a data item for each electronic component in the electronic component data stored in the external storage device 4 and a method for capturing from the input / output device 2 via a user interface (display input). Three methods are prepared: a method for extracting data and a method for extracting data corresponding to parameters from the shape drawing of the electronic component drawing CAD data stored in the external storage device 4.

  According to the latter two methods of extracting data corresponding to the parameters from the external storage device 4, the data acquisition unit 11 inputs the data extracted from the external storage device 4 to the spreadsheet software described later. It also has a function as an extended interface.

  Further, the first calculation unit 12 is customized based on a predetermined design rule to generate a pad stack in which objects are superimposed on each layer from input data acquired via the data acquisition unit 11. It has a function to calculate the layer structure and the overlay coordinates of the object. Specifically, the first calculation unit 12 is calculation means for executing spreadsheet software stored in the main storage device 3, and the spreadsheet software used here stores data such as spreadsheets and database software. Distribution software for processing, storage, calculation, and display.

The first calculation unit 12 described above is a table calculation definition file possessed by the spreadsheet software, and the data expressed by expanding the data into a plurality of matrices in accordance with a calculation formula or format relating to user know-how defined and registered in advance. By calculating according to a predetermined design rule, it is generated and output as data indicating the shape.
As distribution software used here, for example, a spreadsheet such as Microsoft Excel (registered trademark) or database search software such as Access (registered trademark) is known.

The second arithmetic unit 13 has a function of generating a footprint by laying out the pad stack on the mounting terminal coordinates of the electronic component. Specifically, it is a calculation means for executing printed circuit board CAD software stored in the main storage device 3, and distribution software can also be used therefor. As printed circuit board CAD software, for example, EAGLE (registered trademark) of Cad Soft is known.
Further, the cooperation interface unit 14 is a means for executing a cooperation program stored in the main storage device 3 that mediates in order to deliver data created by the spreadsheet software in a form that can be interpreted by the printed circuit board CAD. As this cooperation program, for example, “ActiveX Automation” which is one of communication methods of Windows (registered trademark) of Microsoft Corporation can be used.

  The footprint generated by the second calculation unit 13 is stored in the printed circuit board CAD electronic component DB allocated to the external storage device 5 and is also output and displayed on the input / output device 2.

2 and 3 are operation conceptual diagrams cited for explaining the schematic operation of the printed circuit board CAD system shown in FIG. 1, and FIG. 2 is developed on a working memory used by the first arithmetic unit 12. FIG. FIG. 3 shows each of the pad stack data developed on the work memory used by the second arithmetic unit 13 and the linkage interface unit 14. It is assumed that the above working memory is allocated to an empty area of the main storage device 3.
The schematic operation of the printed board CAD system shown in FIG. 1 will be described below with reference to FIGS.

In FIG. 2, when the arithmetic processing unit 1 performs a table calculation, a shape definition that allows parameter input for the pad stack is performed in advance, and the user operates the input / output device 2 to input data for each parameter according to the shape definition. I do. The data acquisition unit 11 takes in the shape parameter 111 that is the input data and supplies it to the first calculation unit 12 that performs a table calculation. The data acquisition unit 11 may acquire the shape parameter 111 from the external storage device 4 via a built-in extension interface.
Based on the acquired shape parameters, the first computing unit 12 has dimensions and attributes (here, layers, layer names, generated layers, shapes, widths, heights) that specify the object shapes of the electronic components for each layer. From the defined pad stack layer configuration table 121, the layer configuration and shape data customized based on a predetermined design rule are obtained by table calculation. In addition, the first calculation unit 12 is defined by linking to the pad stack layer configuration table 121. From the object attribute table 122 and the object coordinate calculation table 123 registered in advance, an object attribute (here, shape, The configuration object and the number of configurations) and the overlay coordinates (here, the XY coordinates of the layer configuration coordinates 1 to n) of the object are acquired and output to the cooperation interface unit 14.

As shown in FIG. 3, the cooperation interface unit 14 acquires the shape parameter 111 from the data acquisition unit 11, the object coordinate calculation table 123 from the first calculation unit 12, and the table calculation from the object coordinate calculation table 123. The object overlap coordinates (for example, XY coordinates for the start point, end point, circle start point, circle end point, circle center, and circle direction for coordinate 1) are repeatedly acquired by the number of layers based on the layer configuration (layer 1 to layer 11). Then, it is handed over to the second calculation unit 13.
The second computing unit 13 creates a pad stack by superposing the data generated for each layer (here, layer 1 to layer 11) according to the overlay coordinates of each object, and generates the pad stack as an electron. Generate and output footprints by laying out on the component mounting terminal coordinates. The layer data referred to here is land data configured on the surface layer of the printed circuit board, resist data for determining which surface is to be soldered to the land, inner layer data related to the inner layer of the printed circuit board, and hole data. The type.

FIG. 4 is a diagram showing an example of a pad stack constituting a footprint generated and output by the printed circuit board CAD system of the present invention. Here, the pad stack refers to data in which internal objects corresponding to electrode portions of an electronic component are overlaid for each layer.
FIG. 4A shows an insert component (discrete) pad stack in which the terminal penetrates a through hole of the printed circuit board, and FIG. 4B shows an SMD (Surface Mounting Devices) type component that is surface-mounted on the printed circuit board. The pad stack.

FIG. 5 shows a design example in the case of designing the pad of the SMD terminal of the surface mount component. Here, referring to the terminal pitch correspondence table 402 created by the spreadsheet software from the terminal length A of the lead wire installation surface of the SMD type electronic component, each shape of land, resist, and metal mask is specified. An example of generating dimension data B, L, W, R, mask length, and mask width is shown.
The user needs to describe in advance the matrix data constituting the terminal pitch correspondence table 402 and the calculation formula based on the design rule in accordance with each process at each manufacturing location.

On the other hand, when the terminal is a discrete component that passes through the through hole of the printed circuit board, the pad stack is composed of more layer data than the above-described surface-mounted component.
FIG. 6 shows an example of the pad stack layer configuration table 121 prepared for calculating the shape of the discrete component. The pad stack layer configuration table 121 shown here is an example of data description created corresponding to the discrete parts in FIG. 4A, and each data item constituting the columns [601] to [612] has a layer name. , Generation layer, shape table, W, H, D, Xspo, Yspo, pad size, pad name, offset X coordinate, offset Y coordinate. By using the pad stack layer configuration table 121, the user can change the description regarding the calculation formula or the like according to the operation status, and can generate data regarding the layer arrangement and the specified shape according to the usage method.

Here, in the column of the generation layer [602], names necessary for configuring the pad stack of discrete components are described, and the layer names 601 that are actually identified on the CAD corresponding to the respective names are described. is described. The column [603] is a character string representing the shape of the object, and the columns after [604] to [612] are the dimensions and parameters necessary for specifying the shape and the arrangement coordinates (offset) of the internal object. ) Etc. are described.
These various dimensions, attributes, and names can be calculated from data represented by a matrix directly described by the user or related items by the first calculation unit 12 performing a spreadsheet. Based on this layer structure, details of the shape and attributes of each internal object are created.

FIG. 7 shows a design example of the thermal pad. The thermal pad is a pad used when connecting the through hole and the power supply layer, and the shape is expressed as follows.
That is, the thermal shape is identified from the column of the shape table [603] in the pad stack layer configuration table 121 of FIG. 6 described above, and is described in each of the column of the width [604] and the column of the offset Y coordinate [612]. Based on the obtained data, the shape of the internal object is generated by spreadsheet. Then, the attributes (the shape is thermal, the configuration object is a line, the number of configurations) are created based on the object attribute table 122 and the object coordinate calculation table 123 shown in FIGS. 4) and coordinates constituting the object (XY coordinates for each of the constituent layers 1 to 4) are calculated by spreadsheet.

  As described above, according to the printed circuit board CAD system according to the present invention, by expressing the layer configuration and the attributes and coordinates of the internal object with a plurality of matrix data for each electronic component, the internal object can be freely used using user know-how. Can be expressed.

FIG. 9 is a flowchart cited for explaining each step of the footprint generation method in the printed circuit board CAD system of the present invention.
Hereinafter, the steps of the footprint generation method in the printed circuit board CAD system shown in FIG. 1 will be described in detail with reference to the flowchart shown in FIG.

First, for example, as shown in FIG. 10, the user inputs data based on each shape parameter of the electronic component in accordance with the shape parameter setting screen displayed on the input / output device 2 (step ST901). Here, the user selects from the selection items displayed by the system, or directly inputs, for each board type, long hole length w, long hole height h, hole crossing parameter, through the user interface. It takes the form taken in by the system. The imported shape parameter is given a file identifier of the spreadsheet software, and is given a file name as a linkage layer configuration table file used by the linkage interface unit 14 described later, and is stored in the work memory.
Arithmetic processing device 1 acquires shape parameter 111 by data acquisition unit 11 and supplies it to first calculation unit 12 (step ST902). In addition to the shape parameter, data corresponding to the shape parameter is extracted from the data items of the electronic component data stored in the external storage device 4, or the shape corresponding to the electronic component drawing CAD data of the external storage device 4 is used. Data corresponding to parameters may be extracted from the drawing (step ST910) and supplied to the first calculation unit 12 (spreadsheet software).

  The shape parameter setting screen shown in FIG. 10 is implemented by spreadsheet software, printed circuit board CAD software, or a unique application program. The user or system inputs and imports items (shape parameters) necessary for specifying the shape of the electronic component mounted on the printed circuit board.

The cooperation interface unit 14 acquires layer configuration information related to the electronic component from the pad stack layer configuration table 121 generated by the first calculation unit 12 (step ST903), and the object attribute table 122 and the object coordinate calculation table 123. Then, shape coordinates of the object are generated (step ST905), and a pad stack is generated (step ST906).
The cooperation interface unit 14 repeats the above process for the number of layer configurations defined in the pad stack layer configuration table 121 (step ST904), and passes control to the second calculation unit 13. The cooperation interface unit 14 also passes the previously stored cooperation layer configuration file name to the second calculation unit 13.
The second calculation unit 13 acquires a shape parameter from the link layer configuration file name and creates a part body diagram, and obtains the overlay coordinates (pad coordinates) of each object (step ST907), and the pad stack. Generate (step ST908). Then, component data (footprint) is generated by laying out the pad stack in the component terminal coordinates (step ST909).

In order for the cooperative interface unit 14 to execute the above-described processing, it is necessary to set and define in advance in the cooperative interface software which matrix from which the necessary information is to be obtained for each shape parameter. .
The shape parameter is not limited to the format unique to the cooperation interface software, and may be in the form of a file or spreadsheet software. As described above, by linking the linkage interface software with the spreadsheet software, it is possible to generate a free style calculated using the spreadsheet software as a footprint.

On the other hand, the data acquisition unit 11 includes an extended interface, and as described above, the extended interface can be automatically input from various databases in place of items input using the parameter setting screen.
Specifically, one of them is that electronic component attributes and shape parameters are managed by electronic component CAD data stored in the external storage device 4 and supplied as input data to the first arithmetic unit 12 that performs spreadsheets. By doing so, it becomes possible to easily create a footprint from component information centrally managed in a database. The database of electronic components can be obtained and purchased from an external supplier or the like using the Internet or the like, in addition to the database created by the user in the system. This makes it possible to significantly improve the cost and reliability of footprint generation. Further, by linking this database with the circuit diagram CAD, it is possible to automatically generate a footprint in a shape corresponding to the electronic component input by the circuit diagram CAD.

  The other one is to extract necessary parameters from a shape drawing of an electronic component that has been created as electronic component drawing CAD data, and supply it as input data to the first calculation unit 12 that performs a spreadsheet. This CAD data is created using three-dimensional CAD or two-dimensional CAD. There are technologies that are used for three-dimensional display of printed circuit boards by being linked to electronic part drawing CAD data by three-dimensional CAD, or used for mounting check. However, these data are acquired via an extended interface. By doing so, it becomes possible to automatically generate a footprint. In addition to creating electronic component drawing CAD data, it is also possible to obtain and purchase from outside contractors, etc. using the Internet, etc., and in this case, the cost and reliability of footprint generation are greatly improved. It becomes possible to make it.

As described above, the printed circuit board CAD system according to the first embodiment of the present invention basically extends the functions of the printed circuit board CAD software. Characteristically, the spreadsheet software (first The calculation unit 12) and the printed circuit board CAD (second calculation unit 13) are linked in the linkage interface unit 14. As a result, the parts close to know-how with high user dependency, such as design rules, are described in advance in the definition file of the spreadsheet software, and the behavior of the linkage interface unit 14 is set by the shape parameter. .
According to the first embodiment of the present invention, footprints and internal objects having a layer configuration can be automatically generated freely using user know-how. In addition, by defining a shape that allows parameter input for a footprint pad stack having a complex shape in advance, and performing input for each parameter on the screen according to this definition, the burden on the user for creating the footprint is reduced. And streamlining the creation of footprints. Furthermore, by using electronic component data or electronic component drawing CAD data that has already been created and stored in the external storage device 4, these data can be used as input data for the spreadsheet software via the extended interface. This saves time and further automation, and a more convenient printed circuit board CAD system can be constructed.

It is a block diagram which shows the hardware constitutions of the printed circuit board CAD system which concerns on Embodiment 1 of this invention. It is the operation | movement conceptual diagram quoted in order to demonstrate schematic operation | movement of the printed circuit board CAD system shown in FIG. It is the operation | movement conceptual diagram quoted in order to demonstrate schematic operation | movement of the printed circuit board CAD system shown in FIG. It is a figure which shows an example of the pad stick which comprises the footprint produced | generated and output by the printed circuit board CAD system of this invention. It is a figure which shows the example of a design in the case of designing the pad of a SMD component terminal with the printed circuit board CAD system which concerns on Embodiment 1 of this invention. It is a figure which shows an example of the data structure of the pad stack layer structure table prepared for shape calculation of a discrete component. It is a figure which shows the example of a design of a thermal land. It is a figure which shows an example of the data structure of the object attribute table and object coordinate calculation table which are used at the time of the thermal land design shown in FIG. It is the flowchart quoted in order to demonstrate each process of the footprint production | generation method in the printed circuit board CAD system of this invention. It is a figure which shows an example of the screen structure of the shape parameter setting screen used in the printed circuit board CAD system of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Arithmetic processing device, 2 Input / output device, 3 Main storage device, 4, 5 External storage device, 11 Data acquisition part, 12 1st operation part, 13 2nd operation part, 14 Cooperation interface part, 111 Shape parameter, 121 Pad stack layer configuration table, 122 Object attribute table, 123 Object coordinate calculation table.

Claims (6)

In a printed circuit board CAD system that generates a footprint indicating pads provided for attaching electronic components to the printed circuit board,
Define a shape that allows parameter input for the pad stack constituting the footprint, and a data acquisition unit that acquires input data for each parameter according to the shape definition;
A first arithmetic unit that generates a layer configuration customized based on a predetermined design rule and a superimposition coordinate of the object in order to generate the pad stack in which the object is superimposed for each layer from the input data When,
A linkage interface unit that acquires input data acquired via the data acquisition unit and a superimposition coordinate of the object of the electronic component generated by the first calculation unit, and passes to the second calculation unit;
A second arithmetic unit that lays out the pad stack in mounting terminal coordinates of the electronic component and generates the footprint based on the delivered input data and the overlay coordinates of the object;
Equipped with a,
The first calculation unit includes:
Based on the input data acquired via the data acquisition unit, customization based on predetermined design rules by spreadsheet from the pad stack layer configuration table in which the dimensions and attributes that specify the object shape of the electronic component for each layer are predefined The generated layer configuration and shape data are generated, and from the object coordinate calculation table defined by linking to the pad stack layer configuration table, the overlay coordinates and attribute data of the object are generated by table calculation and the cooperation is performed. Supply to the interface part,
Printed circuit board CAD system comprising a call. The data acquisition unit
2. The printed circuit board according to claim 1, wherein input data is taken in for each parameter defined in order to generate the pad stack, which is displayed via a user interface, and is supplied to the first arithmetic unit. CAD system. The data acquisition unit
2. The printed circuit board CAD system according to claim 1, wherein data corresponding to the parameter is extracted from data items for each electronic component stored in an electronic component database and supplied to the first arithmetic unit. The data acquisition unit
2. The printed circuit board CAD system according to claim 1, wherein data corresponding to the parameter is extracted from a shape drawing corresponding to the drawing CAD data of the electronic component and supplied to the first arithmetic unit. The cooperation interface unit
Obtaining layer configuration information about the electronic component from the pad stack layer configuration table output by the first arithmetic unit, obtaining the shape coordinates of the object from the object coordinate calculation table, generating the pad stack, 2. The printed circuit board CAD system according to claim 1 , wherein the pad stack is repeatedly superimposed and output by the number of layer configurations defined in the pad stack layer configuration table. A footprint generation method in a printed circuit board CAD system, comprising at least an input / output device, a storage device, and an arithmetic processing unit, and generating a footprint indicating a conductor pattern of a pad provided for attaching an electronic component to the printed circuit board In
The arithmetic processing unit includes:
Performing a shape definition that allows parameter input for the pad stack constituting the footprint, and obtaining data input for each parameter according to the shape definition from the input device or storage device;
Based on the acquired data input, dimensions and attributes for specifying the object shape of the electronic component are defined for each layer, and a predetermined design rule is calculated by spreadsheet from the pad stack layer configuration table stored in the storage device in advance. Generating customized layer configuration and shape data based on
The object coordinate calculation table defined by linking to the pad stack layer configuration table and stored in the storage device in advance is repeated by the number of times based on the layer configuration based on the layer configuration by overlapping the object and attribute data of the object. Generating step;
Generating the pad stack from the overlay coordinates of the objects, laying out the pad stack on the mounting terminal coordinates of the electronic component, and generating and outputting a footprint;
A method of generating a footprint in a printed circuit board CAD system.

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