KR100806626B1 - Method of modelling for numerical analysys of pcb heat transfer using gerber file - Google Patents

Abstract

A method for modeling numerical analysis of PCB(Printed Circuit Board) heat transfer by using a Gerber file is provided to minimize time needed for numerically analyzing heat transfer of a complex PCB pattern by using a Gerber file and apply to a different analysis tool easily by extracting features of an analysis model as coordinate values. A Gerber file made for designing a PCB is extracted and the extracted Gerber file is output to a monitor(S20). The Gerber file is divided into a plurality of grids having the same width/height in the monitor(S30). A grid to be analyzed is extracted among the grids(S40). The extracted grid is integrated in a rectangular shape satisfying a multiplication condition for the height and the width(S50). The grid is extracted when the Gerber file occupies an area over a predetermined range in the grid. The predetermined range is 50 percents of the entire grid area.

Description

METHOD OF MODELLING FOR NUMERICAL ANALYSYS OF PCB HEAT TRANSFER USING GERBER FILE}

1 is a schematic diagram showing an output step according to the present invention outputs a Gerber file for PCB substrate design to the monitor,

Figure 2 is a schematic diagram showing a grid division step according to the present invention for dividing the output Gerber file into a grid,

3 and 4 is a schematic diagram showing a grating extraction step according to the present invention for extracting a grating to be analyzed,

5 is a schematic diagram showing an integration step according to the present invention incorporating the extracted grating into a rectangular shape,

Figure 6 is a flow chart showing the procedure of the PCB thermal fluid numerical model preparation method using a gerber pile according to the present invention.

The present invention relates to a method for creating a model for thermal fluid numerical analysis of a printed circuit board (hereinafter, referred to as a PCB), and more particularly to a method for modeling a PCB thermal fluid numerical analysis using a gerber pile. .

In general, an electronic circuit design draws circuit diagrams using software such as ^TM Orcad, ^TM Pcad, etc., and then displays the parts information representing the electronic component data (e.g., netlist, etc.) used in the circuit, and the connected state of each component. PCB circuits are designed based on the connection information, etc., which are shown. Gerber data is obtained as a result of the PCB circuit design.

Here, Gerber Data is a data format devised by Gerber Scientific Instrument Co., Ltd. and applied to a photoplotter and started to be used. It is composed of a simple vector format having a shape corresponding to a start point, an end point, and a thickness. It is.

The gerber data includes component data to be mounted, coordinate data, and various marking data. The start point and the end point are Gerber files, and the shape corresponding to the thickness (called Aperture) is an Aperture file to display one pattern. do.

On the other hand, due to the recent development of integrated circuit processing technology, the line width on the PCB is gradually decreasing, and the metal wiring for interconnecting the transistors and the like included in the PCB is also increased in complexity since multilayer wiring is used.

Accordingly, the heat generated per unit area of the PCB is gradually increasing.

However, in order to analyze the heat generated from the PCB in the development stage, an experimental or computer-based numerical calculation method is used.

However, since the method of measuring the generated heat through the experiment is a burden of enormous experiment cost, recently, a numerical calculation method using a computer is mainly used.

In order to accurately predict thermal properties from the PCB, three-dimensional numerical methods must be applied to the physical phenomena associated with the factors that govern thermal properties.

In performing three-dimensional numerical simulations of physical phenomena, the current finite volume method (FVM), finite element method (FEM), finite differential method (FDM), and boundary element method ( Numerical methods such as Boundary Element Method (BEM) are widely used.

The numerical method described above requires a mesh structure that stores the data necessary to perform the numerical simulation. The mesh structure has the initial conditions and boundary conditions required for the numerical analysis and the coordinates of each node. And the like.

However, creating all the mesh structures required to perform numerical analysis on all components of PCBs with increased density and complexity in recent years may reduce the time required for numerical analysis due to the complexity of calculation due to the increase in the number of mesh structures. It is increasing greatly.

Accordingly, an object of the present invention is to provide a method for modeling a PCB heat flow numerical analysis using a gerber pile that can minimize the heat flow numerical analysis time for a complex PCB pattern.

It is still another object of the present invention to provide a model for generating PCB thermal fluid numerical analysis using a gerber file which can be easily applied to heterogeneous analysis tools by extracting the characteristics of an analysis model as coordinate values.

In order to achieve the above object, a model for generating a PCB thermal fluid numerical analysis model using a gerber file according to the present invention includes an extraction step of extracting a gerber file created for PCB design and an output step of outputting the gerber file on a monitor; A grid division step of dividing the output gerber file into a grid, a grid extraction step of extracting a grid to be analyzed among the grids, and an integrated step of integrating the extracted grid into a square shape.

Preferably, the grid division step is to divide the grid into a grid having the same width and height.

In addition, in the grating extraction step, if the gerber file occupies an area over a predetermined range for the grating, it is preferable to selectively extract it.

Here, the predetermined range may be designated as 50% of the grating total area.

Here, the integrating step is a step of integrating the lattice in a quadrangular form satisfying a condition of an integer multiple of both the width and the height of the lattice.

Preferably, the method for preparing a model for numerical analysis of the PCB thermal flow may further include a layer number input step for displaying a specific layer in the multilayer substrate.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram showing an output stage according to the present invention outputting a Gerber file for PCB substrate design to the monitor, Figure 2 is a schematic diagram showing a grid division step according to the present invention to divide the output Gerber file into a grid 3 and 4 are schematic diagrams illustrating a grating extraction step according to the present invention for extracting a grating to be analyzed, and FIG. 5 is a schematic diagram illustrating an integration step according to the present invention for integrating the extracted grating into a rectangular shape. .

Referring to Figures 1 to 5, the method for creating a model for the PCB thermal fluid numerical analysis using the gerber file according to the present invention is an extraction step of extracting the gerber file created for PCB design and the output step of outputting the gerber file on the monitor And a grating division step of dividing the output gerber file into gratings, a grating extraction step of extracting gratings to be analyzed among the gratings, and an integrated step of integrating the extracted grating into a rectangular shape.

Here, the grid division step is preferably a step of dividing the grid into a grid having the same width and height.

In FIG. 1, the gerber file 10 prepared for the PCB design is extracted and output to a screen such as a monitor.

First, a method of preparing the gerber file 10 for PCB design will be described.

The structure of Gerber file data is based on three elements of shape corresponding to start point, end point, and thickness based on simple vector format.

Dual start point and end point are Gerber file, and the shape corresponding to thickness (called Aperture) is Aperture file to display one pattern.

The gerber file data represents the operation of the photoplotter, and therefore its operation principle is the same as that of the photoplotter.

The photoplotter basically consists of a circular wheel called Aperture Wheel with a diameter of 30cm and a light source, and an axis that moves the light source and the wheel to the x and y axes.

The Aperture Wheel is divided into 24 sections so that each segment can be equipped with a film similar to a slide film.

The wheel is divided into 24 equal parts 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 70, 71, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, When the number selection command is recognized by numbering 72, 73, the wheel rotates to move the equal number of the given number (the center of the light source).

The location of the light source is located on one side of the wheel and the photosensitive film on the other side.

There are three states of light source operation: open and closed, and open and closed in the same state (called flash). The light source and the wheel can be moved by the axis in the x and y directions.

Twenty-four films mounted on each Aperture Wheel can be divided into parts with light and non-light in the shape desired by the user. These films are called Aperture.

Combining the configurations and operations of these photoplotters allows the flash to create lines, movements, and pads to appear on the film.

Meanwhile, in FIG. 1, the gerber pile 10 is illustrated as being composed of six parts 12, 14, 16, 17, 18, and 19 for convenience of description.

In the case of FIG. 2, the state in which the gerber files 10 outputted on the monitor are divided into grids 20 is illustrated, and the six gerber files 12, 14, 16, 17, and 18 are provided for convenience of description. 6 gratings 22, 24, 26, 27, 28, and 29 are illustrated correspondingly.

Although the six gratings 22, 24, 26, 27, 28, and 29 are separately illustrated in the six gerber piles 12, 14, 16, 17, 18, and 19 in FIG. 2, the present invention is not limited thereto. In addition, the gerber file 10 may be divided into a grid having the same width and height as the entire monitor screen.

On the other hand, the width and height of the grid to distinguish the gerber pile 10 is not necessarily the same, it may be specified to have a variety of width and height by the interpreter.

  3 and 4, a grating extraction step according to the present invention for extracting gratings to be analyzed will be described.

3A and 3B, one unit grid is shown in the state in which the gerber pile 10 illustrated in FIG. 2 is divided into the grid 20.

In the method of extracting the grid to be analyzed in the state in which the gerber pile 10 is divided by the grid 20, the ratio of the area occupied by the gerber pile 10 of the total area of the grid is determined by the analyst. If more than the ratio of can be specified to be extracted as the analysis target.

Here, the predetermined ratio designated by the analyst is a ratio that can be arbitrarily designated by the analyst in consideration of the situation of component materials, resistance, flow current, and the like in the PCB substrate, and means a range to be considered in the thermal flow numerical analysis.

Preferably, the predetermined ratio may be designated as 50%. 3 illustrates a process of extracting a grid to be analyzed when the predetermined ratio is set to 50%.

That is, in the case of FIG. 3A, the ratio of the area occupied by the gerber pile 13 in the unit grid 23 is 50% or more. In this case, the unit grid 23 may be analyzed. The grid is extracted.

On the contrary, in FIG. 3B, when the ratio of the area occupied by the gerber pile 13-1 in the unit grid 23-1 does not reach 50%, the unit grid 23-1 is to be analyzed. It is not considered as.

FIG. 4 is a diagram showing the grid 25 separating the gerber pile 15 and the present gerber pile 15 shown in FIG. 2.

It can be seen that the ratio of the area occupied by the gerber pile 13 in the plurality of gratings 25 shown in FIG. 4 is less than 50%.

In such a case, the plurality of gratings 25 are not considered to be analyzed.

The gratings extracted by the analysis object grating extraction step as described above are integrated into the largest rectangular shape having the width and height of an integer multiple of the width and height of the present grating.

That is, when the gerber pile 10 occupies an area of 50% or more of the area of the grating 20 of the gerber piles 10 and the gratings 20 shown in FIGS. 1 and 2, the grating to be analyzed Figure 5 shows the result of integrating the extracted gratings into the largest rectangular shape having the width and height of an integer multiple of the width and height of the grating.

The grating 22 disposed at the lower left side of the gerber pile 10 and the grating 20 shown in FIGS. 1 and 2 has a rectangular shape 32 at the lower left shown in FIG. It is integrated into the square shape 8 of the lower center.

In addition, in the case of the "a" shaped gerber pile 14 and the grating 24 occupying the upper and right sides of FIGS. 1 and 2, the upper quadrangle 30 shown in FIG. It is integrated into the right quadrangle 34.

In addition, in the case of the gerber piles 16, 17, 18, 19 and the lattice 26, 27, 28, 29 arranged in the center of Figs. 1 and 2 through the lattice extraction and integration process, The squares 36, 37, 38, 39 were integrated.

By extracting and storing the coordinates of the integrated rectangular shape as described above, it can be used for thermal flow analysis of the PCB through a variety of thermal flow analysis program.

Figure 6 is a flow chart showing the procedure of the model for PCB thermal fluid numerical analysis using a gerber pile according to the present invention.

Hereinafter, with reference to Figure 6, a method for modeling the PCB thermal fluid numerical analysis using the gerber pile according to the present invention will be described.

Referring to FIG. 6, first, a gerber file suitable for PCB design is extracted from a storage means such as a disk, a memory, or a gerber file generating device (step 10).

Thereafter, the extracted gerber file is output to an output means such as a monitor (step 20), and in the case of a multilayer substrate, a layer number is input.

Here, in the thermal flow analysis of the PCB, since the temperature distribution inside the multilayer substrate may vary depending on which layers are arranged in the multilayer substrate, the layer number input step is very important.

Next, the gerber file output on the monitor is divided into grids having the same width and height (step 30).

Next, only the gratings in the case where the Gerberfile occupies an area of a predetermined range, preferably 50% or more, of the area of the grid among the divided grids (step 40).

Next, the extracted gratings are integrated into a maximum square shape having a width and height of an integer multiple of the width and height of the present grating (step 50).

Next, the integrated rectangular coordinates are extracted (step 60) and stored for use in various thermal flow analysis programs.

By the method for modeling the PCB thermal fluid numerical analysis using the gerber pile according to the present invention as described above, it is possible to minimize the thermal fluid numerical analysis time for the PCB pattern of the complex shape, extract the characteristics of the analysis model as coordinate values This makes it easy to apply to heterogeneous analysis tools.

By the method for modeling the PCB heat flow numerical analysis using the gerber pile according to the present invention, it is possible to minimize the heat flow numerical analysis time for the PCB pattern of a complex shape.

In addition, by extracting the characteristics of the analysis model as a coordinate value, it is possible to achieve an effect that can be easily applied to heterogeneous analysis tools.

Claims (6)

An extraction step of extracting a gerber file created for PCB design; An output step of outputting the gerber file on a monitor; A grid division step of dividing the output gerber file into a grid; A lattice extraction step of extracting a lattice to be analyzed from among the lattice; A method of preparing a model for thermal fluid numerical analysis of a printed circuit board using a gerber file, the method comprising: integrating the extracted grid into a rectangular shape. The method of claim 1, The grid classification step is a step of dividing the grid into a grid having the same width and height, the method of creating a model for thermal fluid numerical analysis of a printed circuit board using a gerber file. The method of claim 2, The grating extraction step is a step of selectively extracting the area when the gerber file occupies a predetermined area or more for the grating, characterized in that the model for printed circuit board thermal fluid numerical analysis using a gerber file. The method of claim 3, wherein And a predetermined range is 50% of the total area of the grid. The method of claim 4, wherein The integrating step includes the step of integrating the lattice in a quadrangular form satisfying the condition of an integer multiple for both the width and height of the lattice. The method of claim 5, wherein The PCB thermal fluid numerical model preparation method further comprises a layer number input step for displaying a specific layer in a multi-layer substrate printed circuit board thermal fluid numerical model generation method characterized in that it further comprises.

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