JP2019160235A - Electromagnetic field simulator and operation method for electromagnetic field simulator - Google Patents

Abstract

To provide an electromagnetic field simulator and an operation method for the electromagnetic field simulator with which it is possible to optimally arrange an IC, an oscillator, etc. on a printed circuit board that can be the sources of noise in designing an electronic apparatus and create a model easily.SOLUTION: An electromagnetic field simulator 10 performs modeling of a metal component among structures constituting an electronic apparatus 50 and dividedly calculates a printed circuit board 60, thereby displaying a spot radiating a noise exceeding an EMI level set for each evaluation frequency and an arrangement place of an IC, an oscillator, etc. on the printed circuit board 60 of that time as inappropriate mounting areas 65. Therefore, it is possible to determine the appropriate mounting position of the IC, the oscillator, etc. when designing the electronic apparatus. Furthermore, by performing modeling with only a metal component among structures constituting the electronic apparatus 50, it is possible to create a model easily.SELECTED DRAWING: Figure 11

Description

  The present disclosure relates to an electromagnetic field simulator suitable for use in the design of electronic equipment and an operation method of the electromagnetic field simulator.

  Conventionally, electromagnetic wave analysis is performed by creating a model that reflects only the metal part from mechanism CAD and board data, or all design information such as mechanism CAD and board data is input to convert electromagnetic coupling into an equivalent circuit. There is a method to analyze the circuit. As the former electromagnetic field analysis method, for example, there is one described in Patent Document 1. As the latter circuit analysis method, for example, there is one described in Patent Document 2. The mechanism CAD described above is design data using CAD such as a casing and various parts constituting an electronic device.

  Patent Document 1 discloses a technology for accurately inputting the structures of printed boards, cables, leads, and metal casings of an electric circuit device and calculating the electromagnetic field strength with high accuracy. . Patent Document 2 discloses a technique for extracting a main path of electric energy propagation, creating an equivalent circuit of the main path, and calculating a radiation electric field by circuit analysis.

Japanese Patent Laid-Open No. 7-302278 JP 2010-198201 A

  However, in the electromagnetic field analysis method described in Patent Document 1, the amount of calculation increases due to the expansion of the analysis space, and the analysis is difficult with a general-purpose PC (Personal Computer). In addition, although the arrangement of structures that make up electronic equipment can be improved, it is possible to optimally arrange ICs (Integrated Circuits) and oscillators that are noise sources on a printed circuit board. Can not.

  In the circuit analysis method described in Patent Document 2, in order to calculate an accurate EMI (Electro Magnetic Interference) level under a condition where a propagation path of a noise current cannot be specified in advance, a circuit of a printed circuit board is used. Although it is necessary to reflect the configuration and the wiring mode of the cable in detail in the simulation conditions, in the simulation reflecting the detailed conditions, there is a problem that it takes time to create a model and increases the calculation cost.

  In the present disclosure, an electromagnetic field simulator and an electromagnetic field simulator that can optimally arrange an IC, an oscillator, or the like that is a noise source in the design of an electronic device on a printed circuit board and that can easily create a model. It aims to provide a method.

  An electromagnetic field simulator of the present disclosure includes an input unit for inputting data from the outside, a storage unit for storing the data input via the input unit, and a display unit for displaying the data stored in the storage unit And a control / arithmetic unit that controls the input unit, the storage unit, and the display unit, and performs computation on the data stored in the storage unit and stores a computation result in the storage unit, The control / calculation unit cooperates with at least a part of the input unit, the storage unit, and the display unit to input and input mechanism data of components including a printed circuit board constituting an electronic device. A material information indicating a material of the component corresponding to the mechanism data is input, a metal object is extracted from the mechanism data based on the input material information, and a simulation is performed. And the number of divisions for dividing the printed circuit board that constitutes the electronic device is set based on the model, and the noise frequency that is used in the electronic device or is a noise source from the generated frequency is set. Set, set an evaluation frequency for checking the EMI level, set an EMI level to be checked at the set evaluation frequency, divide the printed circuit board into the set division number, and in each divided area When there is the noise frequency, it is calculated whether or not the evaluation frequency exceeds the EMI level, and when there is a divided area where the evaluation frequency exceeds the EMI level as a calculation result, the division is performed. The area is highlighted as an improper mounting area that improperly mounts a noise source component.

  According to the present disclosure, modeling is performed using only metal parts of the structure constituting the electronic device, and the printed circuit board is divided and calculated to radiate noise exceeding the EMI level set for each evaluation frequency. And the placement location of the IC, oscillator, etc. on the printed circuit board at that time are displayed as an inappropriate mounting area, so that an appropriate mounting position of the IC, oscillator, etc. can be determined. In addition, since design conditions can be examined before trial production, design changes after the trial production are eliminated, generation of useless expenses can be suppressed, and the design period can be shortened. In addition, modeling can be reduced by modeling with only metal parts among the structures constituting the electronic device, thereby reducing calculation costs.

  In the electromagnetic field simulator of the present disclosure, in the above configuration, the mechanism data includes shape, size, and coordinate data of the component.

  According to the present disclosure, since modeling is performed using only metal parts among the structures constituting the electronic device, a model can be easily created.

  In the electromagnetic field simulator of the present disclosure, in the above configuration, the noise frequency includes a divided frequency and a multiplied frequency of the noise frequency.

  According to the present disclosure, it is possible to set an EMI level for determining an evaluation frequency.

  In the electromagnetic field simulator of the present disclosure, in the above configuration, the frequency division frequency and the multiplication frequency are calculated from the noise frequency.

  According to the present disclosure, by obtaining the divided frequency and the multiplied frequency, the frequency up to the divided frequency and the multiplied frequency of the noise frequency can be set as the frequencies at which the EMI level for determining the evaluation frequency should be confirmed. The noise frequency can be determined over the frequency division and multiplication frequency.

  In the electromagnetic field simulator of the present disclosure, in the above configuration, when a component that becomes the noise source is mounted in the mounting inappropriate area, a portion where the evaluation frequency exceeds the EMI level is highlighted.

  According to the present disclosure, it is possible to determine an appropriate mounting position of a component in designing an electronic device. In addition, since design conditions can be examined before trial production, design changes after the trial production can be eliminated, generation of useless expenses can be suppressed, and the design period can be shortened.

  In the electromagnetic field simulator according to the present disclosure, in the configuration described above, when highlighting a portion where the evaluation frequency exceeds the EMI level, the electromagnetic field simulator displays different colors depending on the value of the EMI level.

  According to the present disclosure, since the value of the EMI level can be clearly grasped, the design conditions can be examined before the trial production.

  The operation method of the electromagnetic field simulator according to the present disclosure includes an input unit for inputting data from the outside, a storage unit for storing the data input via the input unit, and the data stored in the storage unit A control unit for controlling the display unit, the input unit, the storage unit, and the display unit, performing computations on the data stored in the storage unit, and storing the computation results in the storage unit, The control / calculation unit is an operation method of an electromagnetic simulator that operates in cooperation with at least a part of the input unit, the storage unit, and the display unit, and is a printed circuit board that constitutes an electronic device The mechanism data of the constituent element including the material data is input, the material information indicating the material of the constituent element corresponding to the input mechanism data is input, and the function is based on the input material information. Extract a metal object from the data, create a model for simulation, set the number of divisions for dividing the printed circuit board constituting the electronic device based on the model, and use in the electronic device, or A noise frequency to be a noise source is set from the generated frequency, an evaluation frequency to be checked for an EMI level is set, an EMI level to be checked at the set evaluation frequency is set, and the set division number is set. When the printed circuit board is divided and the noise frequency is present in each of the divided areas, it is calculated whether or not the evaluation frequency exceeds the EMI level, and the evaluation frequency exceeds the EMI level as a calculation result. If there is a divided area, the improper mounting area that improperly mounts the noise source component. To highlight as A.

  According to the present disclosure, modeling is performed using only metal parts of the structure constituting the electronic device, and the printed circuit board is divided and calculated to radiate noise exceeding the EMI level set for each evaluation frequency. And the placement location of the IC, oscillator, etc. on the printed circuit board at that time are displayed as an inappropriate mounting area, so that an appropriate mounting position of the IC, oscillator, etc. can be determined. In addition, since design conditions can be examined before trial production, design changes after the trial production are eliminated, generation of useless expenses can be suppressed, and the design period can be shortened. In addition, modeling can be reduced by modeling with only metal parts among the structures constituting the electronic device, thereby reducing calculation costs.

  According to the present disclosure, it is possible to optimally arrange an IC, an oscillator, or the like that becomes a noise source in the design of an electronic device on a printed circuit board, and to easily create a model.

The block diagram which shows the structure of the electromagnetic field simulator of 1st Embodiment. The flowchart which shows the main operation | movement step of the electromagnetic field simulator of 1st Embodiment. The flowchart which shows the operation | movement step of the model creation information extraction process of the electromagnetic field simulator of 1st Embodiment. The figure which shows an example of the input screen of the raw material of the determination target in the electromagnetic field simulator of 1st Embodiment The figure which shows an example of the highlight display of the part determined as "the antenna operation part is" in the vehicle-mounted unit which is the material of the determination object shown in FIG. 4, and the noise source determined as "noise source necessary for model creation" The figure which shows an example of the highlight display at the time of setting the evaluation frequency f = 1GHz in the vehicle-mounted unit which is the raw material of the determination object shown in FIG. The flowchart which shows the operation | movement step of the model automatic creation process of the electromagnetic field simulator of 1st Embodiment. The flowchart which shows the operation | movement step of the electromagnetic field analysis process of the electromagnetic field simulator of 1st Embodiment. The figure which shows an example of the highlight display of the electromagnetic field analysis result by the electromagnetic field simulator of 1st Embodiment The block diagram which shows the structure of the electromagnetic field simulator of 2nd Embodiment. The figure which shows the input screen of the electronic device which is the input object of mechanism data in the electromagnetic field simulator of 2nd Embodiment The flowchart which shows the operation | movement step of the electromagnetic field simulator of 2nd Embodiment.

  Hereinafter, an embodiment (hereinafter referred to as “the present embodiment”) that specifically discloses an electromagnetic field simulator according to the present disclosure will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art. The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

  Hereinafter, preferred embodiments for carrying out the present disclosure will be described in detail with reference to the drawings.

(First embodiment)
Hereinafter, the electromagnetic field simulator 1 of the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of an electromagnetic field simulator 1 according to the first embodiment. In the figure, an electromagnetic field simulator 1 displays an input unit 2 for inputting data from the outside, a storage unit 3 for storing data input via the input unit 2, and data stored in the storage unit 3. A control unit 5 that controls the display unit 4, the input unit 2, the storage unit 3, and the display unit 4, performs calculations on the data stored in the storage unit 3, and stores the calculation results in the storage unit 3; .

  The input unit 2 is, for example, a keyboard or a mouse. The storage unit 3 is a mass storage device such as a hard disk or an SSD (Solid State Drive). The display unit 4 is, for example, a liquid crystal display or an organic EL display. The control / calculation unit 5 is, for example, a CPU (Central Processing Unit), and extracts information necessary for creating a model in cooperation with at least a part of the input unit 2, the storage unit 3, and the display unit 4. Model creation information extraction processing to be performed, model automatic creation processing to create a model based on the extracted information, and electromagnetic field analysis processing to the created model. The control / calculation unit 5 outputs a control signal Sc 1 to the input unit 2, outputs a control signal Sc 2 to the storage unit 3, and outputs a control signal Sc 3 to the display unit 4. Data D2 and D3 are exchanged between the control / calculation unit 5 and the storage unit 3. Further, data D1 is output from the input unit 2 to the storage unit 3, and data D4 stored in the storage unit 3 is output to the display unit 4.

  In the model creation information extraction process performed by the control / calculation unit 5, frequency information of a device affected by noise is input as victim information, and frequency information of a component that is a noise source is input as perpetrator information. Here, the frequency of a device affected by noise is called an “evaluation frequency”, and the frequency of a component that is a noise source is called a “noise frequency”. Evaluation frequency information includes installed wireless devices, nearby wireless devices, laws and regulations, and industry group standards. Noise frequency information includes crystal operating frequency, IC operating frequency, and wireless / wired communication frequency. It is. The material to be determined is, for example, an actual product, a photograph, or a mechanism CAD. As described above, the mechanism CAD is design data using CAD such as a casing and various parts constituting an electronic device.

  In the model creation information extraction process, the control / calculation unit 5 determines whether or not a metal part exists in the material after inputting the material to be determined, and if a metal part exists, It is determined that there is an antenna operation unit that operates as an antenna. In addition, in the model creation information extraction process, the control / calculation unit 5 determines whether the noise frequency division or multiplication corresponds to the evaluation frequency, and the noise frequency division or multiplication corresponds to the evaluation frequency. The noise source is determined as a noise source that needs to be modeled.

  The model automatic creation process performed by the control / calculation unit 5 determines whether or not the part has been determined to have an antenna operation part in the model creation information extraction process. Create a model that simplifies the shape other than the judgment part. The electromagnetic field analysis process performed by the control / calculation unit 5 performs an electromagnetic field analysis on the model created by the model automatic creation process.

Next, the operation of the electromagnetic field simulator 1 of the first embodiment will be described.
FIG. 2 is a flowchart showing main operation steps of the electromagnetic field simulator 1 of the first embodiment. In the figure, the control / calculation unit 5 sequentially performs the above-described model creation information extraction process S1, model automatic creation process S2, and electromagnetic field analysis process S3. Hereinafter, these processes will be described in detail.

  FIG. 3 is a flowchart showing the operation steps of the model creation information extraction process S1 of the electromagnetic field simulator 1 of the first embodiment. In the figure, the control / calculation unit 5 controls the input unit 2 to input the evaluation frequency information of the device affected by noise, the noise frequency information of the component that is the noise source, and the material to be determined (step). S10 to step S12). As described above, the evaluation frequency information is information including a mounted wireless device, a nearby wireless device, laws and regulations, an industry group standard, and the noise frequency information is a crystal operating frequency, an IC operating frequency, a wireless / Information including wired communication frequency. The materials to be judged are actual items, photographs, mechanism CAD, and the like.

  The control / calculation unit 5 controls the storage unit 3 to store the evaluation frequency information, the noise frequency information, and the determination target material input by the input unit 2. The evaluation frequency information, the noise frequency information, and the determination target material stored in the storage unit 3 are converted into a data format that can be displayed on the display unit 4 and displayed on the display unit 4. FIG. 4 is a diagram illustrating an example of the input screen 41 for a material to be determined. On the input screen 41 shown in the figure, for example, the in-vehicle unit 20 of the car navigation system imaged by an imaging device such as a camera is shown as a determination target material. In addition, the double frame 42 shown in the figure shows the monitor frame of the display unit 4. The in-vehicle unit 20 is made of metal and is formed in a rectangular parallelepiped shape, and accommodates a printed circuit board 21 therein.

  After the evaluation frequency information, the noise frequency information, and the determination target material are input and stored, the control / calculation unit 5 determines whether or not there is a metal part in the determination target material (for example, the in-vehicle unit 20). Determination is made (step S13). If it is determined that there is a metallic part in the in-vehicle unit 20 (“YES” in step S13), it is determined whether or not there is a location corresponding to λ / 16 to λ of the evaluation frequency in the part (step S14). ). When determining that there is a portion corresponding to the evaluation frequency λ / 16 to λ (“YES” in step S14), the control / calculation unit 5 determines that “the antenna operation unit is present” (step S15), and determines the evaluation frequency. If it is determined that there is no portion corresponding to λ / 16 to λ (“NO” in step S14), it is determined that “no antenna operation unit” (step S17).

  When it is determined in step S13 that the metal material part does not exist in the determination in step S13 (when “NO” is determined in step S13), the control / calculation unit 5 does not perform the determination in step S14. Proceeding to step S17, it is determined that “no antenna operation unit”.

  The control / arithmetic unit 5 determines whether or not all the metal parts have been determined after determining “there is no antenna operation unit” in step S15 or “no antenna operation unit” in step S17 (step S15). S16). That is, in the case where the determination target material is composed of a plurality of metal parts as in the in-vehicle unit 20, it is determined whether the evaluation frequencies correspond to λ / 16 to λ for all metal parts. To do. When determining that there is an undetermined part (“NO” in step S16), the control / calculation unit 5 returns to step S14. On the other hand, if it is determined that all the metal parts have been determined (“YES” in step S16), it is determined whether the noise frequency division / multiplication corresponds to the evaluation frequency (step S18). If the control / calculation unit 5 determines that the frequency division / multiplication of the noise frequency corresponds to the evaluation frequency (“YES” in step S18), the control / calculation unit 5 determines “noise source necessary for model creation” (step S19). Then, the component determined as “with antenna operating unit” and the noise source determined as “noise source necessary for model creation” are highlighted (step S20), and the process is terminated. On the other hand, if it is determined in step S18 that the frequency division / multiplication of the noise frequency does not correspond to the evaluation frequency (determined as “NO”), the processing in step S19 and step S20 is not performed, and “model creation unnecessary. "Noise source" is determined (step S21), and the process ends.

  FIG. 5 is a highlight display of the parts determined as “there is an antenna operation part” and the noise sources determined as “noise source necessary for model creation” in the in-vehicle unit 20 that is the determination target material shown in FIG. It is a figure which shows an example. The example shown in the figure is a highlight display when the evaluation frequency is f = 100 MHz. The component 201 is a component that has been determined as “with antenna operation unit”, and the noise source 202 is a noise source that has been determined as “a noise source that requires model creation”. The component 201 determined to have “antenna operating portion” is mounted on a corner portion of the in-vehicle unit 20 and has a substantially T-shape. The noise source 202 determined as “noise source necessary for model creation” is mounted in a substantially central portion of the in-vehicle unit 20. The component 201 and the noise source 202 are drawn with chain lines to indicate that both are highlighted.

  FIG. 6 is a diagram illustrating an example of a highlight display when the evaluation frequency f = 1 GHz in the in-vehicle unit 20 that is the determination target material illustrated in FIG. 4. When the evaluation frequency f is 1 GHz, the components 203 to 206 are components that are determined as “there is an antenna operation unit”, and the noise source 207 is a noise source that is determined as “a noise source that requires model creation”. Each of the components 203 to 206 determined to have “antenna operating portion” is a recessed portion or a narrow plate-like portion of the main body of the in-vehicle unit 20. Note that these are parts of the in-vehicle unit 20 rather than components, but are merely examples.

  The noise source 207 determined as “noise source necessary for model creation” is mounted at a position slightly deviated from the position of the noise source 202 in FIG. These components 203 to 206 and the noise source 207 are drawn with chain lines to indicate that they are all highlighted. In this way, the metal parts and noise sources corresponding to the evaluation frequency are highlighted.

  FIG. 7 is a flowchart showing the operation steps of the model automatic creation process S2 of the electromagnetic field simulator 1 of the first embodiment. In the figure, the control / arithmetic unit 5 first determines whether or not the metal part is a part that is determined to have “antenna operating part” (step S30), and if it is determined to be the part (“YES” in step S30). Then, the input unit 2 is controlled to input the material information of the part (step S31). On the other hand, if the control / calculation unit 5 determines that the component is not determined as “there is an antenna operation unit” (“NO” in step S30), it does not input the material information of the component (step S32). After performing the process of step S31 or step S32, the control / calculation unit 5 creates a model in which the shape of the determined part other than the determined part is simplified (step S33). For example, a model in which irregularities and holes are closed with metal is created. After creating the model, the control / arithmetic unit 5 determines whether all the components have been determined (step S34), and determines that all the components have not been determined ("NO" in step S34), returns to step S30. If it is determined that all have been determined (“YES” in step S34), the noise source determined as “noise source necessary for model creation” is reflected as a feeding point (step S35), and the process is terminated.

  FIG. 8 is a flowchart showing the operation steps of the electromagnetic field analysis process S3 of the electromagnetic field simulator 1 of the first embodiment. In the figure, the control / calculation unit 5 first performs electromagnetic field analysis using the created model (step S40). Next, the result obtained by the electromagnetic field analysis is displayed with highlights (step S41), and this process is finished.

  FIG. 9 is a diagram illustrating an example of highlight display of the electromagnetic field analysis result. In the example shown in the figure, the magnetic field strength when the evaluation frequency f = 100 MHz is highlighted. Three types of chain lines 301 to 303 indicate magnetic field strengths of 0.8 (A / m), 0.5 (A / m), and 0.3 (A / m). That is, the chain line 301 has a magnetic field strength of 0.3 (A / m), the chain line 302 has a magnetic field strength of 0.5 (A / m), and the chain line 303 has a magnetic field strength of 0.8 (A / m). The chain lines 301 to 303 indicating the magnetic field strength may be changed in color according to the magnetic field strength, or the numerical value of the magnetic field strength may be displayed. When changing the color of the chain lines 301 to 303, for example, the chain line 301 corresponding to 0.3 (A / m) is set to yellow, the chain line 302 corresponding to 0.5 (A / m) is set to orange, and 0.8 ( The chain line 303 corresponding to A / m) is red.

  As described above, the electromagnetic field simulator 1 according to the first embodiment includes evaluation frequency information that is frequency information of a device affected by noise, noise frequency information that is frequency information of a component that is a noise source, and a material to be determined. If there is a part corresponding to λ / 16 to λ of the evaluation frequency when there is a metal part, it is determined whether or not there is a metal part in the determination target material. The part is highlighted as a part determined to have “antenna operating part”, and it is determined whether the frequency division or multiplication of the noise frequency corresponds to the evaluation frequency. A frequency division or multiplication is determined as a noise source necessary for model creation and highlighted, and a model is created by simplifying the shape other than the judgment part of the part judged to have an antenna operating part. The noise source necessary for model creation is reflected on the model as a feeding point, and the electromagnetic field analysis is performed using the obtained model, and the electromagnetic field analysis result is highlighted.

  As described above, the electromagnetic field simulator 1 according to the first embodiment creates a model only with a metal that operates as an antenna, so that the amount of calculation can be reduced and analysis can be easily performed even with a general-purpose PC. In addition, the parts that operate as the antenna operation unit and the noise sources that are determined to be necessary for model creation are highlighted, and the results of the electromagnetic field analysis of the created model are highlighted. Therefore, it is possible to determine the appropriate mounting position of components in the design of electronic equipment, and to study design conditions before prototyping, eliminating design changes after prototyping and generating unnecessary expenses. It can be suppressed and the design period can be shortened.

  In the electromagnetic field simulator 1 of the first embodiment, the target portion is highlighted on the screen, but only the target portion may be displayed.

  In the electromagnetic field simulator 1 of the first embodiment, a model is created only with a metal that operates as an antenna. However, manual correction can be supported as necessary, and a flat metal plate other than the target portion can be handled. You may make it model with.

  In addition, the cloud may have the function of the electromagnetic field simulator 1 of the first embodiment to provide a service on the cloud.

(Second Embodiment)
FIG. 10 is a block diagram showing a configuration of the electromagnetic field simulator 10 of the second embodiment. In the figure, the same reference numerals are given to the portions common to FIG. 1 described above. In the figure, the electromagnetic field simulator 10 of the second embodiment models an electronic device composed of a casing, a printed circuit board, a heat dissipation component, etc., with a metal component among the components constituting the electronic device. The simulation is performed by designating the frequency, the input unit 2 for inputting data from the outside, the storage unit 3 for storing the data input via the input unit 2, and the data stored in the storage unit 3 Control unit 4 for controlling the display unit 4, the input unit 2, the storage unit 3 and the display unit 4 for displaying the data, performing calculations on the data stored in the storage unit 3, and storing the calculation results in the storage unit 3 Unit 11.

  Note that control signals output from the control / calculation unit 11 to the input unit 2, the storage unit 3 and the display unit 4, data exchange between the control / calculation unit 11 and the storage unit 3, and input unit 2 to storage unit The output of data to 3 and the output of data from the storage unit 3 to the display unit 4 are the same as those of the electromagnetic field simulator 1 of the first embodiment described above.

The electronic device is an in-vehicle unit of a car navigation system, for example. 11A and 11B are diagrams showing the input screen 41 of the electronic device 50, where FIG. 11A shows an input screen when the upper housing (lid) 52 is removed from the lower housing 51, and FIG. 11B shows the lower housing 51. 7 is an input screen when the upper casing 52 is attached to the screen. As shown in the figure, the lower casing 51 of the electronic device 50 has a shape in which a front part and a rear part are bent at right angles, and both left and right sides are open, and two plate-like pieces 53 are provided on both left and right sides. have. The two plate-like pieces 53 on the left and right sides are spaced apart. Here, the front side of the two plate-like pieces 53 on the right side as viewed in FIG. 11 is 53 ₁ , the rear side is 53 ₂ , the front side of the two plate-like pieces 53 on the left side is 53 ₃ , and the rear side is and 53 _4. Plate-shaped pieces ₅₃ 1-53 ₄ of the lower housing 51 is used to fix the upper housing 52 to lower housing 51. A printed circuit board 60 is accommodated in the lower casing 51.

  Returning to FIG. 10, the control / calculation unit 11 is, for example, a CPU, and includes a printed circuit board 60 constituting the electronic device 50 in cooperation with at least a part of the input unit 2, the storage unit 3, and the display unit 4. Enter the mechanism data of the component, input material information indicating the material of the component corresponding to the input mechanism data, extract a metal object from the mechanism data based on the input material information, and create a model for simulation create. The mechanism data is the shape, dimension, and coordinate data of the upper and lower casings 51 and 52, the components (not shown), and the printed circuit board 60 that constitute the electronic device 50, and is input by the input unit 2. The material information is material information of the upper and lower casings 51 and 52, parts (not shown), and the printed circuit board 60 in the mechanism data, and is input by the input unit 2.

  Based on the created model, the control / arithmetic unit 11 obtains an improper mounting area 65 (see FIG. 11) on the printed circuit board 60 constituting the electronic device 50 that inappropriately mounts a component that becomes a noise source. The improper mounting area 65 is highlighted. That is, the control / arithmetic unit 11 performs the following processing to obtain the improper mounting area 65 and highlights it. Note that areas other than inappropriate areas indicate appropriate areas.

(1) Based on the created model, the number of divisions for dividing the printed circuit board 60 constituting the electronic device 50 is set. The number of divisions is, for example, 8/16/32/64, and the higher the number of divisions, the higher the mounting position (mounting position of components such as IC and oscillator) can be calculated.
(2) The noise frequency used as the noise source is set from the frequency used in the electronic device 50 or generated.
(3) Set the evaluation frequency for checking the EMI level.
(4) Set the EMI level to be confirmed at the evaluation frequency set in (3).

(5) When the printed circuit board 60 is divided into the number of divisions set in (1) and the noise frequency set in (2) is present in each of the divided areas, the evaluation frequency set in (3) is ( It is obtained by calculating whether or not the EMI level set in 4) is exceeded.
(6) If there is a divided area in which the evaluation frequency set in (3) exceeds the EMI level set in (4) as a result of calculation in (5), the divided area is used as a noise source component. It is highlighted as an improper mounting area 65 that improperly mounts (IC, oscillator, etc.). Note that areas other than inappropriate areas indicate appropriate areas.

As highlighted, the evaluation frequency locations exceeds the EMI level set is assumed to be a plate-like piece 53 ₂ of the lower housing 51 shown in FIG. 11, for example, lightning marks around the plate-like pieces 53 ₂ 70 is displayed. At this time, the display of the lightning mark 70 may be blinked. Further, when highlighting a portion where the evaluation frequency exceeds the set EMI level, it may be displayed in different colors depending on the value of the EMI level, or the value of the EMI level may be displayed. May be. For example, it is displayed in yellow when 10 to 20 (dB μV / m), is displayed in orange when 20 to 30 (dB μV / m), and is displayed in red when 30 to 40 (dB μV / m). Thus, when implementing the component IC and oscillators such as a noise source to implement improper area 65, a high plate-shaped piece 53 and _second portion exceeds the EMI level evaluation frequency is set or lower housing 51 Light display.

Next, the operation of the electromagnetic field simulator 10 of the second embodiment will be described.
FIG. 12 is a flowchart showing the operation steps of the electromagnetic field simulator 10 of the second embodiment. In the figure, the control / arithmetic unit 11 first inputs mechanism data including the shapes, dimensions, and coordinates of the upper and lower casings 51, 52, components (not shown), and the printed circuit board 60 constituting the electronic device 50 (step). S50). Next, the control / arithmetic unit 11 inputs the upper and lower casings 51 and 52 of the mechanism data, the parts (not shown), and the material information of the printed circuit board 60 (step S51).

  After inputting the mechanism data and material information, the control / calculation unit 11 creates a model using them (step S52). That is, the control / calculation unit 11 extracts a metal object from the input mechanism data based on the input material information, deletes a non-metal object from the mechanism data, and creates a model for simulation.

  The control / arithmetic unit 11 sets the number of divisions of the printed circuit board 60 after creating a model for simulation (step S53). That is, the control / arithmetic unit 11 sets the number of divisions in consideration of the size of the printed circuit board 60 disposed in the electronic device 50 and the components (such as an IC or oscillator that becomes a noise source) mounted on the printed circuit board 60. To do. For example, the division number of 8/16/32/64 is set.

  The control / arithmetic unit 11 sets the noise frequency information after setting the number of divisions of the printed circuit board 60 (step S54). That is, the control / arithmetic unit 11 sets a frequency that becomes a noise source from a frequency that is used or generated in the electronic device 50. Further, the control / arithmetic unit 11 calculates a divided frequency and a multiplied frequency of the set noise frequency and includes them in the noise frequency.

  After setting the noise frequency information, the control / calculation unit 11 sets an evaluation frequency for checking the EMI level (step S55).

  The control / calculation unit 11 sets an EMI level to be confirmed for the set evaluation frequency (step S56).

  After setting the EMI level, the control / calculation unit 11 calculates the EMI level (step S57). That is, the control / arithmetic unit 11 divides the printed circuit board 60 by the number of printed circuit board divisions set in step S53, and if each of the divided areas has the noise frequency set in step S54, the setting is made in step S55. It is calculated whether or not the evaluated frequency exceeds the EMI level set in step S56.

  The control / calculation unit 11 displays the calculation result of the EMI level (step S58). That is, when there is a divided area in which the evaluation frequency set in step S55 exceeds the EMI level set in step S56 as a result of the calculation in step S57, the control / calculation unit 11 sets the noise source in the divided area. In order to recognize that an IC, an oscillator or the like is not arranged, the divided area is highlighted. At the same time, the portion exceeding the EMI level set at step S56 is highlighted and the value is displayed.

  As described above, the electromagnetic field simulator 10 of the second embodiment performs modeling with only the metal parts of the structure constituting the electronic device 50, and divides and calculates the printed circuit board 60 for each evaluation frequency. A location where noise exceeding the set EMI level is radiated and an arrangement location of an IC, an oscillator, etc. on the printed circuit board 60 at that time are displayed as an improper mounting area 65.

  By displaying an improper mounting area 65 such as an IC or an oscillator on the printed circuit board 60 for each noise frequency, an appropriate mounting position of the IC or the oscillator can be determined. In addition, since design conditions can be examined before trial production, design changes after the trial production are eliminated, generation of useless expenses can be suppressed, and the design period can be shortened.

  Further, modeling is performed only with metal parts in the structure constituting the electronic device 50, so that the amount of calculation can be reduced, thereby reducing the calculation cost.

  In addition, you may make it provide a service on a cloud by giving the cloud the function which the electromagnetic field simulator 10 of 2nd Embodiment has.

  The electromagnetic field simulator of the present disclosure is useful for designing electronic devices.

1,10 electromagnetic simulator 2 input section 3 storing unit 4 display unit 5 and 11 control and operation unit 20 onboard unit 21 printed circuit board 41 input screen 42 monitor frame 50 electronic apparatus 51 the lower housing 52 upper casing 53 _{1-53 4} Plate-like piece of lower housing 51 60 Printed circuit board 65 Improper mounting area 70 Lightning mark 201 Parts 202 and 207 Noise sources 203 to 206 Parts 301 to 303 A chain line indicating magnetic field strength

Claims (7)

An input unit for inputting data from the outside;
A storage unit for storing the data input via the input unit;
A display unit for displaying the data stored in the storage unit;
A control / calculation unit that controls the input unit, the storage unit, and the display unit, and performs computation on the data stored in the storage unit and stores a computation result in the storage unit,
The control / calculation unit cooperates with at least a part of the input unit, the storage unit, and the display unit,
Enter mechanism data of components including printed circuit boards that make up electronic equipment,
Enter material information indicating the material of the component corresponding to the input mechanism data,
Based on the input material information, extract a metal object from the mechanism data, create a model for simulation,
Based on the model,
Set the number of divisions to divide the printed circuit board constituting the electronic device,
Use within the electronic device, or set the noise frequency to be a noise source from the generated frequency,
Set the evaluation frequency to check the EMI level,
Set the EMI level to be confirmed at the set evaluation frequency,
Dividing the printed circuit board into the set number of divisions, and when there is the noise frequency in each of the divided areas, calculating whether the evaluation frequency exceeds the EMI level,
When there is a divided area in which the evaluation frequency exceeds the EMI level as a calculation result, the divided area is highlighted as an improper mounting area that inappropriately mounts a component that is a noise source.
Electromagnetic simulator. The electromagnetic field simulator according to claim 1,
The mechanism data includes shape, size and coordinate data of the component,
Electromagnetic simulator. The electromagnetic field simulator according to claim 1 or 2,
The noise frequency includes a divided frequency and a multiplied frequency of the noise frequency.
Electromagnetic simulator. The electromagnetic field simulator according to claim 3,
The frequency division and multiplication frequency are calculated from the noise frequency.
Electromagnetic simulator. An electromagnetic field simulator according to any one of claims 1 to 4,
When the component that becomes the noise source is mounted in the mounting inappropriate area, the portion where the evaluation frequency exceeds the EMI level is highlighted.
Electromagnetic simulator. The electromagnetic field simulator according to claim 5,
When highlighting a portion where the evaluation frequency exceeds the EMI level, it is displayed in a different color depending on the value of the EMI level.
Electromagnetic simulator. An input unit for inputting data from the outside, a storage unit for storing the data input via the input unit, a display unit for displaying the data stored in the storage unit, the input unit, and the storage And a control / calculation unit that controls the data stored in the storage unit and stores the calculation result in the storage unit, the control / calculation unit, An operation method of an electromagnetic simulator that operates in cooperation with at least a part of the input unit, the storage unit, and the display unit,
Enter mechanism data of components including printed circuit boards that make up electronic equipment,
Enter material information indicating the material of the component corresponding to the input mechanism data,
Based on the input material information, extract a metal object from the mechanism data, create a model for simulation,
Based on the model,
Set the number of divisions to divide the printed circuit board constituting the electronic device,
Use within the electronic device, or set the noise frequency to be a noise source from the generated frequency,
Set the evaluation frequency to check the EMI level,
Set the EMI level to be confirmed at the set evaluation frequency,
Dividing the printed circuit board into the set number of divisions, and when there is the noise frequency in each of the divided areas, calculating whether the evaluation frequency exceeds the EMI level,
When there is a divided area in which the evaluation frequency exceeds the EMI level as a calculation result, the divided area is highlighted as an improper mounting area that inappropriately mounts a component that is a noise source.
Operation method of electromagnetic simulator.

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