JP2006154983A - Thermal design simulation method for printed circuit board, and thermal design simulation support program for printed circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a work load applied to a designer when changing an implementation component in a thermal design simulation method for a printed circuit board, and a thermal design simulation support program for a printed circuit board. <P>SOLUTION: Data relevant to a two-dimensional shape such as a wiring pattern of an implementation component or a board, and component information data are extracted from a data file of a two-dimensional CAD format to create a three-dimensional simulation model. A shape and size information in a Z axis direction, and information relevant to physical values of the implementation component which cannot be acquired from the data file of the two-dimensional CAD format are acquired by searching a component data library of a component library, and a model shape database. When information relevant to the corresponding implementation component does not exist, a component having an approximate function and a physical property is used instead. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermal design simulation support method and a thermal design simulation support program for supporting a thermal design simulation by a simulation system constructed by ANSYS (registered trademark), MSC (registered trademark), and the like, and is particularly configured with two or more layers. The present invention relates to a thermal design simulation of a printed circuit board.

  When designing a printed circuit board composed of two or more layers, generally, simulation and trial production are repeated in order to predict the thermal influence of the heat source, and sufficient consideration is given to the heat source. This is because the heat source provided on the substrate has a very large influence on the thermal design of the entire substrate, and supports the thermal design of a printed circuit board composed of two or more layers as shown in Patent Document 1. Various simulation systems and programs have been developed.

  FIG. 16 is an explanatory diagram showing a thermal design simulation method for a printed circuit board composed of two or more layers according to the prior art. In FIG. 16, 40 is a thermal design simulation model, 40a is the first layer, 40b is the second layer, 40c is the third layer, 40d is the fourth layer, 41a to 41h are wiring patterns, and 42a to 42l are through holes. 43a and 43b are heat sources, and 44a to 44d are resins. The thermal design simulation model 40 shown in FIG. 16A relates to a printed circuit board having four layers. The first layer 40a to the fourth layer 40d are obtained by modeling four layers, respectively. The heat generation sources 43a and 43b are models of devices that generate heat such as a CPU and a transformer.

  In the simulation in the prior art shown in FIG. 16, a heat transfer analysis is performed assuming that portions other than the heat generation sources 42a and 42b of the simulation model 40 are uniform materials, and the thermal influence by the heat generation sources 42a and 42b is predicted. Yes. However, actually, as shown in FIG. 16B, a printed circuit board such as wiring patterns 41a to 41h, through holes 42a to 42l, and resins 44a to 44d is formed in portions other than the heat sources 43a and 43b. There are various elements. Therefore, if all of these are made uniform as shown in FIG. 16A, it is naturally difficult to accurately predict the thermal effect, and the reliability of the analysis result is lowered. After all, designers have to try out a prototype simulation model to see the thermal effects in the real thing. Therefore, the designer has a considerable work load.

  Therefore, the present inventor attempted to solve this problem by the invention shown in Patent Document 2. FIG. 14 is an explanatory diagram showing a configuration of a simulation model in which the present inventors have solved the problem. In FIG. 14, 10 is a thermal design simulation model, 10a is the first layer, 10b is the second layer, 10c is the third layer, 10d is the fourth layer, 11a to 11h are wiring patterns, and 12a to 12l are through holes. , 13a and 13b are heat sources, and 14a to 14d are resins. FIG. 15 is a flowchart showing an outline of the thermal design simulation work that the present inventors have attempted to solve the problem.

  The thermal design simulation model 10 shown in FIG. 14A relates to a printed circuit board having four layers. The first layer 10a to the fourth layer 10d are obtained by modeling four layers, respectively. As shown in FIG. 14B, wiring patterns 11a and 11b, through holes 12a and 12b, and a heat source 13a are disposed on the first layer 10a with respect to the resin 14a, and the second layer 10b includes Wiring patterns 11c and 11d and through holes 12c to 12f are arranged with respect to the resin 14b. In addition, wiring patterns 11e and 11f and through holes 12g to 12j are disposed on the third layer 10c with respect to the resin 14c, and further, wiring patterns 11g and 11h are disposed on the fourth layer 10c with respect to the resin 14d. Through holes 12k and 12l and a heat source 13b are arranged.

  Then, using the model shown in FIG. 14, a drawing data file in a two-dimensional CAD format is first created by a CAD program (S1), and a thermal design simulation support program for a printed circuit board is operated to draw drawing data in a two-dimensional CAD format. Information necessary for creating the thermal design simulation model 10 is extracted from the file, and an inconvenient portion caused by the specification of the CAD program of the extracted information is corrected. Furthermore, information that is insufficient for creating the thermal design simulation model 10 is input, and the thermal design simulation model 10 is made available in the simulation system (S2). Next, the data of the thermal design simulation model 10 is input to the simulation program, the analysis conditions are set and the analysis is executed (S3), and the result is displayed on a display or the like (S4). Check whether the analysis result of the thermal effect of the displayed heat source is within the range assumed in the design. If it is outside the range assumed in the design, the process returns to S3 and the conditions are reset (S5). Further, if it is within the range assumed in the design, a printed circuit board composed of two or more layers is prototyped to finally confirm the thermal influence (S6).

  In other words, the invented thermal design simulation support program extracts information on the printed circuit board wiring patterns and mounted parts from the data file in the two-dimensional CAD format, and further, it is necessary for the thermal design simulation of materials, dimensions, etc. A simulation model was created with additional information added, and this model was passed to the simulation program so that analysis could be performed. As a result, the reliability of the analysis result could be improved.

However, when simulating a model that includes a new mounted component, the attribute information required for the analysis is set manually while the thermal design simulation support program is running in order to perform a thermal analysis that matches the new component. There is a need to. Even if information about the mounted components once analyzed can be stored in the storage means, the components mounted on the printed circuit board are extremely diverse, and it is unavoidable to perform thermal design simulation using unanalyzed components. I can say that I want to. Reducing the burden of manual input remained as a problem to be solved.
Japanese Patent Laid-Open No. 9-245076 Japanese Patent Application No. 2004-22358

  In view of the above problems, the present invention provides a thermal design simulation method for a printed circuit board and a thermal design simulation support program for a printed circuit board that can reduce the work burden on a designer when changing a mounted component. The purpose is to provide.

  As means for solving the above-mentioned problems, the present invention models a printed circuit board having a structure in which two or more layers are stacked, and performs heat transfer analysis on the model to predict the printed circuit board. A printed circuit board thermal design simulation method for supporting thermal design of the printed circuit board on a computer, comprising: a printed circuit board generated by a CAD system; and a mounting component mounted on the printed circuit board. A two-dimensional CAD format data file is prepared, and from the data file, the layer information of the printed circuit board and the mounting component and the identification information of the mounting component are input to the computer, and heat transfer from the layer Select the analysis target layer necessary for analysis, and the implementation related to each analysis target layer When there is attribute information of the mounted component by determining whether there is attribute information of the mounted component in the component library storing the attribute information of the component that can be mounted on the printed circuit board using the identification information of the product. Acquires this attribute information, and if there is no attribute information of the mounted component in the component library, acquires attribute information of an alternative component that is functionally closest to the mounted component, and the thickness of the analysis target layer When the information regarding the via hole formed in the printed circuit board is input to the computer and there is a mounting component that generates heat in the analysis target layer, the generated mounting component generates heat. Information indicating that the source is input to the computer, information on the interlayer resin of the printed circuit board, wiring pattern and via material, Information on the temperature of the printed circuit board atmosphere and heat radiation from the printed circuit board to the atmosphere is input to the computer, all the information input to the computer, attribute information of the mounted component, or the alternative The component attribute information is input to a simulation system capable of executing thermal analysis, and the thermal analysis is executed in the simulation system.

  Therefore, according to the above means, when acquiring information related to a mounted component of the printed circuit board, if there is no mounted component attribute information in the component library storing the component attribute information, the mounted component is functional. Since the attribute information of the substitute part that is most similar to is acquired, the thermal analysis can be executed by the simulation system using the attribute information of the substitute part.

  In the thermal design simulation support method according to the present invention, the component library includes at least identification information of each component that can be mounted on a printed circuit board and attribute names of these components, property names, Information on the shape and height can be stored.

  Further, according to the present invention, the component library can store component classification information defined by the functional proximity of the components stored in the component library.

  As a means for solving the above problems, the present invention is mounted on a printed circuit board having a structure in which two or more layers are stacked in a thermal design simulation support program for a printed circuit board, and the printed circuit board. Necessary for heat transfer analysis from the first procedure of acquiring information of all layers from the drawing data file of the mounted component in 2D CAD format and storing it in the storage means, and the information of the layers stored in the storage means A second procedure for selecting a specific analysis target layer, and the identification information of the mounted component related to each analysis target layer is read out from the layer information stored in the storage means, and the identification information is used. It is determined whether or not there is attribute information of the mounted component in a component library in which attribute information of components that can be mounted on the printed circuit board is stored. When there is attribute information of the mounted component, the attribute information is acquired. When the attribute information of the mounted component does not exist in the component library, the attribute information of the substitute component whose attribute approximates the mounted component is acquired. A third procedure for storing information on via holes formed in the printed circuit board input from the input unit in the storage unit, and the analysis target layer input from the input unit. A fifth procedure for storing in the storage means information identifying a mounting component that is an existing heat source, and information relating to the interlayer resin, wiring pattern and via material of the printed circuit board, which is input from the input means; A sixth procedure for storing in the storage means information on the temperature of the atmosphere of the printed circuit board and heat radiation from the printed circuit board to the atmosphere; and Converts all information input from the input means stored in the storage means and the attribute information of the part or the attribute information of the part replacement part into predetermined format data that can be used in a simulation system capable of performing thermal analysis And a seventh procedure for outputting the predetermined format data as a file is executed on a computer.

  Therefore, according to the above means, when acquiring information related to a mounted component of the printed circuit board, if there is no mounted component attribute information in the component library storing the component attribute information, the mounted component is functional. Since the attribute information of the substitute part that is most similar to is acquired, the thermal analysis can be executed by the simulation system using the attribute information of the substitute part.

  In the thermal design simulation support program for a printed circuit board according to the present invention, in the third procedure, when the component attribute information does not exist in the component library, the respective components stored in the component library It is also possible to read out the component classification information defined by the functional closeness between components from the library, and execute the processing that uses the component that is most similar to the mounted component from the component classification information as the substitute component. .

In the present invention, even when there is no attribute information of the mounting component to be analyzed, the thermal design simulation can be performed using the attribute information of the alternative component, which is necessary when performing the simulation. The burden of manually inputting attribute information can be reduced. Eventually,
This makes it possible to increase the efficiency of designing a printed circuit board having a structure in which two or more layers are stacked.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to the embodiments described below. For example, a specific configuration related to a data input method, data stored in a database, and the like is within the scope described in each claim. Various modifications can be made without departing from the scope. Further, the simulation model to be the subject of the present invention is a component on a printed circuit board (hereinafter referred to as a multilayer printed circuit board) having a structure in which two or more layers are laminated as shown in the model shown in FIG. Anything that implements can be applied.

  First, a configuration example of a computer on which a thermal design simulation support program for a multilayer printed circuit board according to the present invention is installed and a network system including the computer will be described. FIG. 12 is a block diagram illustrating a configuration example of a computer in which a thermal design simulation support program for a multilayer printed circuit board is installed. In FIG. 12, 30 is a computer, 31 is a CPU, 32 is a ROM, 33 is a RAM, 34 is a keyboard, 35 is a media drive, 36 is a display, 37 is a network interface, 38 is a hard disk drive, and 39 is a bus. FIG. 13 is a block diagram showing a configuration example of a network system including the computer shown in FIG. In FIG. 13, reference numerals 25, 26, and 27 denote analysis terminals, 28 denotes a database server, and 29 denotes a simulation server.

  The computer 30 is installed with a thermal design simulation support program and a two-dimensional CAD program, and creates all data necessary for the thermal design simulation. Of course, the configuration of FIG. 12 is merely an example, and other devices such as a mouse and a pen tablet may be provided. A simulation program such as ANSYS may be installed in the computer 30 so that it can be used for thermal design simulation. Furthermore, it is also possible to store a later-described component library in a storage medium such as a CD-R / W in the media drive 35.

  FIG. 13 shows an example in which the computer 30 is incorporated in a network system. Here, the computer 30 is used as one of client computers. The database server 28 provides the client computer with a parts library composed of two databases, a physical property database and a model shape database. Further, the simulation server 29 executes a simulation by ANSYS or the like. Note that the hardware configuration capable of implementing this embodiment is not limited to that shown in FIGS. 12 and 13 and may be any configuration as long as processing described below is possible.

  Here, the physical property value database and the model shape database will be described. FIG. 3 is an explanatory diagram showing an example of a data table of the physical property value database. FIG. 4 is an explanatory diagram showing an example of a data table of the model shape database.

  As shown in FIG. 3, the physical property value database holds physical property value data necessary for analyzing the influence of heat generation of components and the like such as the thermal conductivity of each mounted component and board constituent material. Further, since the component information data and the physical property values corresponding to the data are described as one table, it is easy to search using the component information as a key. Further, as shown in FIG. 4, the model shape database holds the three-dimensional shapes of the respective mounted components and board constituent materials as coordinate values. Since the component information data and the coordinate values corresponding to the data are described as one table, it is easy to search using the component information as a key.

  Next, the work outline of the thermal design simulation in the embodiment of the present invention will be described. FIG. 1 is a flowchart showing an outline of work of thermal design simulation in an embodiment of the present invention.

  In the present invention, first, a drawing data file in a two-dimensional CAD format corresponding to a model to be analyzed is created by a two-dimensional CAD program. At that time, component information described later is always added to each mounted component. Next, the component information data included in the drawing data file is extracted and stored in the storage means of the computer. Furthermore, a tool for creating a model for a thermal design simulation support program for a multilayer printed circuit board, which will be described later, is activated, and the shapes of components and boards necessary for creating a thermal design simulation model from a drawing data file in a two-dimensional CAD format Data and later-described component information data are extracted (S1). Next, information that is insufficient in creating the thermal design simulation model is input, and the thermal design simulation model is made available in the simulation system (S2).

  Note that the information that is insufficient in creating the thermal design simulation model is, for example, a case where a figure of a wiring pattern that should be closed is output as a file without being closed, as will be described later. After completing the input, refer to the component library to convert the two-dimensional information of the component and wiring pattern obtained from the two-dimensional CAD data into three dimensions, and obtain the necessary physical properties of the component and wiring pattern to obtain a simulation model. Build up. Further, when the physical property value corresponding to the component information data does not exist in the component library, that is, when the information of the physical property value of the component is not obtained, the component having the closest physical property is substituted.

  Next, replenishment of data lacking in the thermal design simulation model and setting of analysis conditions are performed, and thermal analysis is executed (S3). Then, the result is displayed on a display or the like (S4). Check whether the analysis result of the thermal effect of the displayed heat source is within the range assumed in the design. If it is outside the range assumed in the design, the process returns to S3 and the conditions are reset (S5). If it is within the range assumed in the design, a trial production of a multilayer printed circuit board is performed to finally confirm the thermal influence (S6).

  In the example shown in FIG. 1, the operation of the thermal design simulation support program for the multilayer printed circuit board and the operation of the simulation program are described as being performed continuously. And the simulation program may be operated completely separately. That is, in the thermal design simulation support program for multilayer printed circuit boards, the thermal design simulation model is created and the necessary settings are made for the simulation program, and the thermal design simulation model is output in a file format that can be used by the simulation program. It is also possible to end the process. In this case, since only the simulation can be executed with the output file, the operations from the creation of the thermal design simulation model to the display of the analysis result can be appropriately divided and performed.

  Here, the component information data will be described. The part information data is assigned to each part, and is systematized according to the type of part. An example of systematization of parts is shown in FIGS. FIG. 2 is a plan view showing an example of a mounted state of components in a drawing produced by two-dimensional CAD. FIG. 5 is an explanatory diagram illustrating an example of a method for classifying mounted components.

  The component information data is the most basic information for identifying each component. Specifically, as shown in FIG. 2, depending on the type of each component to be mounted, a Q-system symbol such as “Q1” or “Q2” is used for a semiconductor element such as a MOSFET, and “R1” or “ Symbols of the R system such as “R2”, symbols of the C system such as C1 are attached to the capacitor, and IC symbols such as “IC1” are attached to the IC such as the control CPU.

  In addition, as a classification method of component information data, as shown in FIG. 5, it is preferable to divide systematically according to each function and thermal property (physical property), and to make the symbol system according to this classification. The number added after each symbol is a serial number. This serial number is preferably assigned so that parts having similar functions and physical properties are close to each other. Further, it is more preferable that the components having the closest functions and physical properties are given so as to be adjacent numbers (for example, “14” and “15”). This classification makes it easier for designers to check whether the alternative part selected by the program is really appropriate when creating a model using the alternative part described later. is there. It is also possible to add a symbol according to other information such as a component manufacturer.

  Next, the operation of the thermal design simulation support program for the multilayer printed circuit board in the first embodiment will be described. 6 to 8 are flowcharts (1) to (3) showing the operation of the thermal design simulation support program for the multilayer printed circuit board.

  This thermal design simulation support program is originally for creating a thermal design simulation model that can be used by a simulation program from a drawing data file in a two-dimensional CAD format. In the following description, a simulation program and What can be linked will be described. These programs will be described as being installed on the computer shown in FIG. 12 and further used on the network system shown in FIG.

  As shown in FIG. 6, the format of the drawing data file in the two-dimensional CAD format is set according to the operation of the keyboard 34 of the designer or the like so that the necessary format can be set for the thermal design simulation support program for the multilayer printed circuit board. Is stored in the RAM 33 (S11). This is because there are various formats such as DXF and GDS in the two-dimensional CAD format, and it is necessary to match the format used by the designer. In order to be able to confirm the contents set by the designer etc. on the spot, it is preferable that a setting user interface is always displayed on the display 36 so that the work status can be confirmed.

  Next, in accordance with the operation of the keyboard 34, the dimension unit (mm, cm, point, etc.) of the graphic pattern data of the input drawing data file in the two-dimensional CAD format is stored in the RAM 33 (S12). Similarly, the setting of output options for the thermal design simulation model to be output is also stored in the RAM 33 (S13). This output option varies depending on the simulation program. For example, if the output option is output in the ANF format (format by ANSYS), it is possible to set the dimensional unit of the model. The operations in S12 and S13 are necessary for setting the size and the like of the multilayer printed circuit board.

  Further, in accordance with the operation of the keyboard 34, a file for creating a simulation model is read from the media loaded in the media drive 35 (S14), and the read pattern of each layer is displayed on the display 36 so that the designer can check it. (S15). Note that this file may exist in the hard disk drive 38 or another computer on the network system.

  Further, the aforementioned part information data is extracted from the drawing data file and stored in the hard disk drive 38 (S16). This process can also be performed after S17 or S18.

  Next, because the pattern of the wiring or the like is not a closed figure due to the configuration of the CAD program, the pattern is restored to a closed one (S17). S17 will be described in more detail. FIG. 9 is an explanatory diagram of pattern restoration by a thermal design simulation support program for a multilayer printed circuit board. As shown in FIG. 9A, the graphic pattern read from the file has polyline vertices I and J overlapping, and the polyline vertex K is divided. Therefore, in S17, the overlapping polyline vertices are arranged, and the divided polyline vertices are connected and restored as shown in FIG. 9B, and stored in the RAM 33. When using a program that can output a drawing data file without causing such division, it is preferable that S17 can be omitted.

  Returning to FIG. 6, the number of layers of the multilayer printed circuit board, the material of each layer, and data relating to the two-dimensional shape such as the mounting component and the wiring pattern of the board are extracted from the drawing data file and stored in the RAM 33 (S18). . If the entire multilayer printed circuit board is not to be analyzed, only necessary ones may be extracted.

  Next, as shown in FIG. 7, the component data library and the model shape database are searched using the component information data stored in the RAM 33 as a key (S19). Then, it is confirmed whether or not information corresponding to the part information data exists in these databases (S20). And when the corresponding information exists, the physical property value required for heat transfer analysis of a mounted component etc. is extracted. Further, the model shape database is searched to convert a two-dimensional shape into a three-dimensional shape, and a part model is created together with physical property values. Then, the created part model is stored in the hard disk drive 38 (S21).

  If there is no information corresponding to the part information data in S20, the closest part is selected as an alternative part (S22), and the process of S21 is performed. Note that the rule for selecting an alternative part varies depending on the part classification method and the structure of the part information data, but for example, the rule is to select the closest number of the same system symbol. It should be noted that a combination of each component and its substitute component may be tabulated in advance and selected using this table. It is also possible to finish the work of the designer or the like at the stage of finishing S21.

  Next, a tool for automatically creating a simulation model for heat transfer analysis is activated in accordance with an instruction from a designer or the like (S23). Then, the instructed model is read, and the model created in S21 is displayed on the display 36 (S24). Then, whether or not the designer or the like modifies the model created in S21 is determined by an instruction from the designer or the like (S25). Then, when there is an instruction for reworking, it is possible to replace or modify the mounted parts of the model manually (S26). At this time, it is highly desirable to enumerate information necessary for model creation on the window displayed on the display 36 in an easy-to-understand manner so that a designer or the like can correct the model and confirm an input error. If no rework is necessary, the process proceeds from S25 to S27.

  Next, as shown in FIG. 8, information such as the thickness of various patterns including through holes can be input from the keyboard 34 (S27). Further, the input information at this time is displayed on the display 36. FIG. 11 is an explanatory diagram showing a display example of information necessary for model creation. In this embodiment, the display is as shown in FIG. 11, but of course this is only an example, and another configuration may be adopted. For example, it may be configured such that a pattern that is a target of information input is displayed first, and a pattern that becomes a next target is displayed when information such as a thickness necessary for the pattern is input. When a numerical value or the like is input from the keyboard 34 to the window shown in FIG. 11, it is preferably displayed immediately on the display 36.

  Returning to FIG. 8, in accordance with the instruction from the keyboard 34, the designated layer pattern is displayed on the display 36, the designated internal resin pattern is extracted, the result is stored in the RAM 33, and the display 36 is further displayed. It is displayed (S28).

  Here, the extraction of the internal resin pattern will be specifically described. FIG. 10 is an explanatory diagram showing an example of extraction of the internal resin pattern. In FIG. 10, 20 and 22 are metal patterns, and 21 is a resin pattern. As shown in FIG. 10A, some wiring patterns include a resin pattern such as an island like a resin pattern 21 interposed between the metal pattern 20 and the metal pattern 22. . What is in the metal pattern such as the resin pattern 21 may become an obstacle to automatically creating a simulation model for heat transfer analysis. Therefore, in order to improve the calculation accuracy of the heat transfer analysis, the purpose of this procedure is to extract it in advance according to instructions from the designer or the like.

  Returning to FIG. 8, in accordance with the instruction from the keyboard 34, the pattern of the instructed transformer, CPU, etc. is set as a heat source and a resist pattern to which the heat source is connected, and the heat source is designated on the component surface, or soldering is performed. Whether or not to designate the surface is also set according to the instruction, and the setting information is stored in the RAM 33 (S29). Further, according to instructions from the keyboard 34, setting of thermal conductivity and thermal emissivity of each pattern, presence / absence of thermal radiation, etc. (S30), setting direction of the multilayer printed circuit board, setting of options specific to each simulation program, etc. Is stored in the RAM 33 (S31). It should be noted that it is very desirable to display the setting contents from S28 to S31 on the display 36 for easy confirmation by the designer. Further, the order from S27 to S31 can be changed as appropriate.

  And the information memorize | stored in RAM33 is passed to each simulation programs, such as ANSYS, and a heat transfer analysis is performed (S32). When the analysis is completed, the simulation program displays the analysis result image on the display 36 (S33), and further stores this image in the medium of the media drive 35 (S34). This completes the thermal design simulation support program for the multilayer printed circuit board. In order to facilitate the repeated execution of the heat transfer analysis, the thermal design simulation support program for the multilayer printed circuit board may stand by in a state where the procedure from S25 onward can be executed after the end of S34. . The operation control of each procedure described above is performed by the CPU 31.

  In the present invention, the part related to model creation of the thermal design simulation support program for the multilayer printed circuit board described in the first embodiment and the part where information is manually assigned or set by the operator to the created model are completely included. Separate programs can be used separately. According to this configuration, the thermal design simulation support program for the multilayer printed circuit board can be installed in an old-style computer where it is difficult to use the simulation program.

It is a flowchart which shows the operation | work outline | summary of the thermal design simulation in the Example of this invention. It is a top view which shows an example of the mounting state of the components in the drawing produced with two-dimensional CAD. It is explanatory drawing which shows an example of the data table of a physical-property value database. It is explanatory drawing which shows an example of the data table of a model shape database. It is explanatory drawing which shows an example of the classification method of mounted components. It is a flowchart (1) which shows operation | movement of the thermal design simulation assistance program of a multilayer printed circuit board. It is a flowchart (2) which shows operation | movement of the thermal design simulation assistance program of a multilayer printed circuit board. It is a flowchart (3) which shows operation | movement of the thermal design simulation assistance program of a multilayer printed circuit board. It is explanatory drawing of the pattern restoration by the thermal design simulation support program of a multilayer printed circuit board. It is explanatory drawing which shows the extraction example of an internal resin pattern. It is explanatory drawing which shows the example of a display display of the information required for model creation. It is a block diagram which shows the structural example of the computer which installed the thermal design simulation assistance program of the multilayer printed circuit board. It is a block diagram which shows the structural example of the network system containing the computer shown in FIG. It is explanatory drawing which shows the structure of the simulation model which this inventor aimed at solution of a subject. It is a flowchart which shows the operation | work outline | summary of the thermal design simulation which this inventor aimed at solution of a subject. It is explanatory drawing which shows the thermal design simulation method of the printed circuit board comprised by two or more layers based on a prior art.

Explanation of symbols

10: Thermal design simulation model 10a: First layer 10b: Second layer 10c: Third layer 10d: Fourth layers 11a-11h: Wiring patterns 12a-12l: Through holes 13a, 13b: Heat sources 14a-14d: Resin 20 : Metal pattern 21: Resin pattern 22: Metal pattern 31: CPU
32: ROM
33: RAM
34: keyboard 35: media drive 36: display 37: network interface 38: hard disk drive 39: bus 40: thermal design simulation model 40a: first layer 40b: second layer 40c: third layer 40d: fourth layers 41a-41h : Wiring patterns 42a to 42l: Through holes 43a and 43b: Heat generation sources 44a to 44d: Resin

Claims (5)

Supports thermal design of the printed circuit board on a computer by modeling a printed circuit board having a structure in which two or more layers are laminated, and conducting a heat transfer analysis on the model to predict the printed circuit board. A printed circuit board thermal design simulation method comprising:
Preparing a data file in a two-dimensional CAD format of the printed circuit board generated by a CAD system and a mounting component mounted on the printed circuit board;
From the data file, the printed circuit board and the mounting component layer information, and the mounting component identification information is input to the computer,
Select the analysis target layer necessary for heat transfer analysis from the above layers,
Using the identification information of the mounted component related to each analysis target layer, it is determined whether or not there is attribute information of the mounted component in a component library storing component attribute information that can be mounted on a printed circuit board. If there is attribute information of the mounted component, the attribute information is acquired. If the attribute information of the mounted component does not exist in the component library, the attribute information of the substitute component that is functionally closest to the mounted component. Get
Input information about the thickness of the analysis target layer into the computer,
Input information about via holes formed in the printed circuit board into the computer,
When there is a mounted component that generates heat in the analysis target layer, information indicating that the generated mounted component is a heat generation source is input to the computer,
Information on the interlayer resin of the printed circuit board, wiring pattern and via material, temperature of the atmosphere of the printed circuit board, and information on heat radiation from the printed circuit board to the atmosphere are input to the computer,
All information input to the computer and the attribute information of the mounted component or the attribute information of the alternative component are input to a simulation system capable of executing thermal analysis,
A thermal design simulation method for a printed circuit board, wherein thermal analysis is executed in the simulation system. The component library stores at least identification information of each component that can be mounted on a printed circuit board, and information related to the name, property value, shape, and height, which are attribute information of these components. The thermal design simulation support method for a printed circuit board according to claim 1. 3. The printed circuit board according to claim 1, wherein the component library stores component classification information defined by functional proximity between the components stored in the component library. 4. Thermal design simulation support method. First, information of all layers is acquired from a printed circuit board having a structure in which two or more layers are stacked and a drawing data file in a two-dimensional CAD format of a mounted component mounted on the printed circuit board, and is stored in a storage unit. And the steps
A second procedure for selecting an analysis target layer necessary for heat transfer analysis from the layer information stored in the storage means;
The identification information of the mounted component related to each analysis target layer is read out from the layer information stored in the storage means, and attribute information of components that can be mounted on a printed circuit board using the identification information is stored. It is determined whether or not there is attribute information of the mounted component in the component library, and if there is attribute information of the mounted component, this attribute information is acquired, and the attribute information of the mounted component does not exist in the component library In this case, a third procedure for acquiring attribute information of an alternative part whose attribute approximates to the mounted part;
A fourth procedure for storing, in the storage means, information on via holes formed in the printed circuit board, input from the input means;
A fifth procedure for storing, in the storage unit, information specifying a mounting component that is input from the input unit and serves as a heat source existing in the analysis target layer;
Information regarding the interlayer resin of the printed circuit board, the wiring pattern and the material of the via, the temperature of the atmosphere of the printed circuit board, and the information regarding the heat radiation from the printed circuit board to the atmosphere input from the input means A sixth procedure for storing in the storage means;
All the information input from the input means stored in the storage means and the attribute information of the part or the attribute information of the part replacement part are converted into predetermined format data that can be used in a simulation system capable of performing thermal analysis. A seventh procedure to convert;
An eighth procedure for outputting the predetermined format data as a file;
Is executed on a computer, a thermal design simulation support program for a printed circuit board. In the third procedure, if the component attribute information does not exist in the component library, the component classification information defined by the functional proximity of the components stored in the component library is stored in the library. 5. The thermal design simulation support program for a printed circuit board according to claim 4, wherein a process that uses the component classification information as a substitute component that is functionally closest to the mounted component is executed from the component classification information.

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