JP2007241658A - Method, device and program for computing heat conductivity - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for computing heat conductivity of a board according to the constitution of an insulating layer. <P>SOLUTION: An insulating layer modeling section 14 models the insulating layer of three-layer structure corresponding to the volume ratio of glass and resin constituting the insulating layer when a filler such as glass included in the insulating layer is fibrous. An insulating layer equivalent heat conductivity computing section 15 computes the heat conductivity of the modeled insulating layer of three-layered structure in an in-plane direction and a plane perpendicular direction of the insulating layer respectively based on the heat conductivity of the resin and filler such as glass constituting the insulating layer input by a material information input section 12. A wiring layer equivalent heat conductivity computing section 18 computes the equivalent heat conductivity for every small region divided by a board region group dividing section 16. An output section 19 outputs the computed equivalent heat conductivity of the insulating layer and the computed equivalent heat conductivity of a wiring layer for every small region. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermal conductivity calculation method, apparatus, and program for calculating an equivalent thermal conductivity of a substrate in thermal evaluation of electronic equipment using a computer, and more particularly, to a thermal conductivity calculation method that takes into account the configuration of an insulating layer. , Apparatus, and program.

  Thermal evaluation of electronic devices is performed by simulation such as a finite volume method using a computer. When performing the simulation, it is necessary to replace the substrate to be evaluated with an analysis model and obtain the equivalent thermal conductivity of the substrate.

  As a first conventional technique for obtaining the equivalent thermal conductivity, the substrate is divided into a plurality of small region groups, and the surface of the substrate is determined from the wiring area in the wiring layer of each divided small region and the thickness of the wiring layer and the insulating layer. A thermal conductivity calculation method is disclosed in which an equivalent thermal conductivity in an inward direction and an in-plane vertical direction (hereinafter referred to as a perpendicular direction) is obtained and thermal evaluation is performed (see, for example, Patent Document 1).

According to Patent Document 1, the thermal conductivity λp in the in-plane direction is calculated by the following equation.
λp = A + B
Here, A = Σ (αi (λAPi + λB (1−Pi))), and Σ represents the total sum of only the wiring layers. B = Σ (αiλB) where Σ represents the sum of only the insulating layers. λA is the thermal conductivity (W / mk) of the wiring material, λB is the thermal conductivity (W / mk) of the insulator material, and αi is the thickness of the i-th layer material equal to the total thickness of the substrate. The ratio is Σαi = 1, and Pi is the wiring portion area ratio of the wiring layer. The thermal conductivity λt in the direction perpendicular to the plane is calculated by the following equation.
λt = 1 / (C + D)
Here, C = Σ (αi / (λAPi + λB (1−Pi))), and Σ represents the sum of only the wiring layers. D = Σ (αi / λB), and Σ represents the sum of only the insulating layers. λA is the thermal conductivity (W / mk) of the wiring material, λB is the thermal conductivity (W / mk) of the insulator material, and αi is the thickness of the i-th layer material equal to the total thickness of the substrate. The ratio is Σαi = 1, and Pi is the wiring portion area ratio of the wiring layer.

  However, in the first conventional technique, when the direction of the wiring pattern is biased, for example, when it is only in one direction, the direction is the same in all directions even though the thermal conductivity in the same direction as the direction of the wiring pattern is high. If the wiring pattern orientation in the substrate plane is anisotropic, that is, biased, the thermal conductivity in the in-plane direction cannot be represented accurately.

  As a second conventional technique, there is a thermal conductivity calculation method that can solve this problem. In this thermal conductivity calculation method, the substrate is divided into a plurality of small region groups, the wiring pattern is determined for each of the divided small regions, and is classified into patterns. Furthermore, the wiring area ratio for each wiring layer in the small region is calculated, and the wiring pattern anisotropy is calculated using a calculation formula defined for each pattern based on the calculated wiring area ratio and the classified pattern. The equivalent thermal conductivity in consideration is calculated (see, for example, Patent Document 2).

JP 2000-180395 A JP 2004-227337 A

  The wiring layer of a board | substrate has a very high ratio of the contained copper, and can be handled as single copper as a value of thermal conductivity. The insulating layer is often made of a composite material in which glass is contained in an epoxy resin as a filler, and it is necessary to calculate thermal conductivity as a composite material of epoxy resin and glass. As the filler, there are those in which powdered glass is used, and those in which fibrous glass known as FR4 (glass epoxy) is used. When powdered glass is used as the filler, anisotropy does not occur in the thermal conductivity, but the fibrous glass has a network structure in the in-plane direction of the layer and is configured as a glass cloth. As a result, anisotropy occurs in the thermal conductivity. The heat conductivity in the in-plane direction of the insulating layer is greater than that in the direction perpendicular to the plane because of heat conduction by the glass cloth. In many cases, the laser flash method is used to measure the thermal conductivity of glass epoxy (glass epoxy) in the insulating layer used on the substrate. In this case, the heat in the thickness direction of a sample with a thickness of several millimeters is used. Only the conductivity can be obtained, and the thermal conductivity in the in-plane direction cannot be accurately known. Therefore, when fibrous glass is used as the filler, when calculating the equivalent thermal conductivity of the insulating layer, in addition to the data and volume ratio of each physical property value of the constituent material, the structure of the insulating layer, that is, the insulating layer It is necessary to consider the anisotropy in the in-plane direction and the perpendicular direction by modeling according to the manufacturing method.

  Any of the above-described conventional techniques has a problem in that the thermal conductivity of the insulating layer cannot be accurately represented because the difference in thermal conductivity caused by the configuration of the insulating layer is not taken into consideration.

  The objective of this invention is providing the thermal conductivity calculation method, apparatus, and program which can calculate the thermal conductivity of a board | substrate according to the structure of an insulating layer.

The present invention relates to substrate shape information indicating the shape of a substrate in which wiring layers on which wiring patterns are formed and insulating layers for insulating the wiring patterns from wiring patterns of other wiring layers are alternately stacked, Acquisition step of acquiring wiring information representing a wiring pattern, material information representing a material constituting the wiring layer and the insulating layer, heat conductivity information representing the thermal conductivity of each material, and manufacturing method information representing a manufacturing method for generating the insulating layer When,
A modeling step for modeling each insulating layer into a model insulating layer determined according to the manufacturing method indicated by the manufacturing method information acquired in the acquiring step;
An insulating layer equivalent thermal conductivity calculation step of calculating an equivalent thermal conductivity of each model insulating layer modeled in the modeling step based on the material information and thermal conductivity information acquired in the acquisition step;
Based on the substrate shape information acquired in the acquisition step, a dividing step of dividing the shape of the substrate into a predetermined shape portion;
Based on the wiring information acquired in the acquisition process, for each wiring layer included in each part divided in the dividing process, a wiring area ratio representing the ratio of the area of the wiring pattern to the surface area of the wiring layer of each part A wiring area ratio calculating step to calculate;
Based on the wiring area ratio calculated in the wiring area ratio calculation step and the material information and thermal conductivity information acquired in the acquisition step, the equivalent thermal conductivity for each wiring layer is calculated for each part. A calculation process;
An output step for outputting the equivalent thermal conductivity of each insulating layer calculated in the insulating layer equivalent thermal conductivity calculation step and the equivalent thermal conductivity for each wiring layer calculated in the wiring layer equivalent thermal conductivity calculation step; It is the thermal conductivity calculation method characterized by including.

  According to the present invention, first, in the obtaining step, the shape of the substrate on which the wiring layers on which the wiring patterns are formed and the insulating layers for insulating the wiring patterns from the wiring patterns of the other wiring layers are alternately stacked is represented. Substrate shape information, wiring information representing the wiring pattern of each wiring layer, material information representing the material constituting the wiring layer and the insulating layer, thermal conductivity information representing the thermal conductivity of each material, and the method of producing the insulating layer In the modeling process, each insulating layer is modeled as a model insulating layer determined according to the manufacturing method indicated by the manufacturing information acquired in the acquisition process, and in the insulating layer equivalent thermal conductivity calculation process Based on the material information and thermal conductivity information acquired in the process, the equivalent thermal conductivity of each model insulating layer modeled in the modeling process is calculated.

  Furthermore, in the dividing step, the shape of the substrate is divided into predetermined portions based on the substrate shape information acquired in the acquiring step, and in the wiring area ratio calculating step, based on the wiring information acquired in the acquiring step. For each wiring layer included in each part divided in the dividing step, a wiring area ratio representing the ratio of the area of the wiring pattern to the surface area of the wiring layer in each part is calculated, and a wiring layer equivalent thermal conductivity calculating step Then, based on the wiring area ratio calculated in the wiring area ratio calculation process and the material information and thermal conductivity information acquired in the acquisition process, the equivalent thermal conductivity for each wiring layer of each part is calculated. Then, the equivalent thermal conductivity of each insulating layer calculated in the insulating layer equivalent thermal conductivity calculation step and the equivalent thermal conductivity for each wiring layer of each portion calculated in the wiring layer equivalent thermal conductivity calculation step are output.

  In this way, first, each insulating layer is modeled as a model insulating layer determined according to the manufacturing method indicated by the manufacturing method information, and the equivalent thermal conductivity of each modeled insulating layer is converted into material information and heat conductivity information. Calculate based on Next, based on the substrate shape information, the shape of the substrate is divided into predetermined shape portions, and for each wiring layer included in each divided portion, the surface of the wiring layer of each portion is determined based on the wiring information. Calculate the wiring area ratio that represents the ratio of the area of the wiring pattern to the area, and calculate the equivalent thermal conductivity for each wiring layer of each part based on the calculated wiring area ratio and material information and thermal conductivity information, Furthermore, since the calculated equivalent thermal conductivity of each insulating layer and equivalent thermal conductivity for each wiring layer of each part are output, the thermal conductivity of the substrate is calculated according to the manufacturing method of the insulating layer, that is, the configuration of the insulating layer. be able to.

The present invention also provides substrate shape information representing the shape of a substrate in which wiring layers on which wiring patterns are formed and insulating layers for insulating the wiring patterns from wiring patterns of other wiring layers are alternately stacked, and each wiring layer Acquire wiring information representing the wiring pattern, material information representing the material constituting the wiring layer and the insulating layer, thermal conductivity information representing the thermal conductivity of each material, and manufacturing information representing the manufacturing method that produced the insulating layer Means,
Modeling means for modeling each insulating layer into a model insulating layer determined according to the manufacturing method indicated by the manufacturing method information acquired by the acquiring unit;
Insulating layer equivalent thermal conductivity calculating means for calculating the equivalent thermal conductivity of each model insulating layer modeled by the modeling means based on the material information and thermal conductivity information acquired by the acquiring means,
Based on the substrate shape information acquired by the acquisition unit, a dividing unit that divides the shape of the substrate into predetermined shape parts;
Based on the wiring information acquired by the acquiring means, for each wiring layer included in each part divided by the dividing means, a wiring area ratio representing a ratio of the area of the wiring pattern to the surface area of the wiring layer of each part is calculated. A wiring area ratio calculating means for calculating;
Based on the wiring area ratio calculated by the wiring area ratio calculating means and the material information and thermal conductivity information acquired by the acquiring means, the equivalent thermal conductivity for each wiring layer of each part is calculated. A calculation means;
Output means for outputting the equivalent thermal conductivity of each insulating layer calculated by the insulating layer equivalent thermal conductivity calculating means and the equivalent thermal conductivity of each part of the wiring layer calculated by the wiring layer equivalent thermal conductivity calculating means; It is the thermal conductivity calculation apparatus characterized by including.

  According to the present invention, the substrate shape representing the shape of the substrate in which the wiring layer on which the wiring pattern is formed and the insulating layer for insulating the wiring pattern from the wiring pattern of the other wiring layer are alternately stacked by the obtaining unit. Information, wiring information representing the wiring pattern of each wiring layer, material information representing the material constituting the wiring layer and the insulating layer, thermal conductivity information representing the thermal conductivity of each material, and manufacturing method representing the method of producing the insulating layer Information is acquired, and each insulating layer is modeled as a model insulating layer determined according to the manufacturing method indicated by the manufacturing method information acquired by the acquiring unit by the modeling unit, and the acquiring unit is calculated by the insulating layer equivalent thermal conductivity calculating unit. Based on the material information and the thermal conductivity information acquired by the above, the equivalent thermal conductivity of each model insulating layer modeled by the modeling means is calculated.

  Further, based on the substrate shape information acquired by the acquisition unit by the dividing unit, the shape of the substrate is divided into predetermined shape portions, and based on the wiring information acquired by the acquisition unit by the wiring area ratio calculation unit. For each wiring layer included in each part divided by the dividing means, a wiring area ratio representing the ratio of the area of the wiring pattern to the surface area of the wiring layer of each part is calculated, and the wiring layer equivalent thermal conductivity calculating means Based on the wiring area ratio calculated by the wiring area ratio calculating means and the material information and thermal conductivity information acquired by the acquiring means, the equivalent thermal conductivity for each wiring layer of each part is calculated, and the output means , The equivalent thermal conductivity of each insulating layer calculated by the insulating layer equivalent thermal conductivity calculating means and each calculated by the wiring layer equivalent thermal conductivity calculating means Equivalent thermal conductivity of the minute wiring layer each is output.

  In this way, first, each insulating layer is modeled as a model insulating layer determined according to the manufacturing method indicated by the manufacturing method information, and the equivalent thermal conductivity of each modeled insulating layer modeled is material information and thermal conductivity information. Is calculated based on Next, based on the substrate shape information, the shape of the substrate is divided into predetermined shape portions, and for each wiring layer included in each divided portion, the surface of the wiring layer of each portion is determined based on the wiring information. A wiring area ratio representing the ratio of the area of the wiring pattern to the area is calculated, and based on the calculated wiring area ratio and material information and thermal conductivity information, an equivalent thermal conductivity for each wiring layer is calculated, In addition, the calculated equivalent thermal conductivity of each insulating layer and the equivalent thermal conductivity of each wiring layer are output, so the thermal conductivity of the substrate is calculated according to the manufacturing method of the insulating layer, that is, the configuration of the insulating layer can do.

Further, in the present invention, the model insulating layer determined according to the manufacturing method is a model including a layer having a layer thickness corresponding to the volume ratio of each constituent material constituting the insulating layer when the manufacturing method is a manufacturing method using a fibrous filler. An insulating layer,
The insulating layer thermal equivalent conductivity calculating means, when the filler of the insulating layer indicated by the material information acquired by the acquiring means is a fibrous filler, for each model insulating layer modeled by the modeling means The equivalent thermal conductivity in the in-plane direction and the equivalent thermal conductivity in the in-plane vertical direction are calculated.

  According to the present invention, when the filler of the insulating layer is a fibrous filler, the insulating layer is modeled as a model insulating layer composed of layers having a layer thickness corresponding to the volume ratio of each constituent material constituting the insulating layer. For each model insulating layer modeled and modeled, the equivalent thermal conductivity in the in-plane direction and the equivalent thermal conductivity in the in-plane vertical direction are calculated, so the thermal conductivity of the insulating layer containing the fibrous filler differs. It is possible to calculate the thermal conductivity taking into account the difference between the thermal conductivity in the in-plane direction and the thermal conductivity in the in-plane vertical direction.

  Further, according to the present invention, the insulating layer thermal equivalent conductivity calculating means is configured such that when the filler of the insulating layer indicated by the material information acquired by the acquiring means is a powder filler, each constituent material constituting the insulating layer is provided. The thermal conductivity averaged by the volume ratio is calculated.

  According to the present invention, when the filler of the insulating layer is a powder filler, the thermal conductivity averaged by the volume ratio of each constituent material constituting the insulating layer is calculated, so the powder filler is contained. The thermal conductivity of the insulating layer can be calculated.

  Moreover, this invention is a program for functioning a computer as each means of the said thermal conductivity calculation apparatus.

  According to the present invention, the computer can function as each unit of the thermal conductivity calculation device.

  According to the present invention, since the thermal conductivity of the substrate can be calculated according to the configuration of the insulating layer, it is possible to calculate a more accurate equivalent thermal conductivity of the substrate and more accurate thermal evaluation of the electronic device. It can be performed.

  Further, according to the present invention, since the thermal conductivity of the substrate can be calculated according to the configuration of the insulating layer, the more accurate equivalent thermal conductivity of the substrate can be calculated, and more accurate heat of the electronic device can be calculated. Evaluation can be made.

  Further, according to the present invention, the thermal conductivity considering the difference between the thermal conductivity anisotropy, that is, the thermal conductivity in the in-plane direction and the thermal conductivity in the in-plane vertical direction for the insulating layer containing the fibrous filler. Since it can be calculated, the thermal conductivity of the substrate using the fibrous filler as the filler of the insulating layer can be calculated more precisely, and more accurate thermal evaluation of the electronic device can be performed.

  Further, according to the present invention, the thermal conductivity of the insulating layer containing the powder filler can be calculated, so the thermal conductivity is also calculated for the substrate using the powder filler as the filler of the insulating layer. Thus, thermal evaluation of the electronic device can be performed.

  Further, according to the present invention, it is possible to cause a computer to function as each means of the thermal conductivity calculation device.

  FIG. 1 is a block diagram showing a functional configuration of a thermal conductivity calculation apparatus 1 according to an embodiment of the present invention. The thermal conductivity calculation device 1 functions as a control unit 10, a substrate shape information input unit 11, a material information input unit 12, an insulating layer manufacturing information input unit 13, an insulating layer modeling unit 14, and an insulating layer equivalent thermal conductivity calculation unit. 15, substrate area dividing unit 16, wiring area ratio calculating unit 17, wiring layer equivalent thermal conductivity calculating unit 18, output unit 19, CAD (Computer Aided Design) information data verse 21, material information database 22, insulating layer manufacturing information database 23, and an output result database 24.

The thermal conductivity calculation device 1 is configured by a computer including an input device, a control device, a storage device, and an output device as hardware. The input device is configured by an input device such as a keyboard or a mouse, and the control device is, for example, a CPU (Central
Processing unit) and an I / O (Input / Output) interface connected to the CPU. The storage device is configured by, for example, a hard disk, a flexible disk, or a CDROM (Compact Disk Read Only Memory). For example, it is configured by a display device such as CRT (Cathode Ray Tube) or LCD (Liquid Crystal Display), or a printing device such as a printer. The hardware configuration is not limited to these. For example, an information database included in a CAD device or an external storage device using a communication function may be used as an input device, and a plurality of CPUs may be used as a control device. A parallel computing device may be used, and a configuration with excellent operability and calculation speed may be employed.

  The control unit 10 includes a substrate shape information input unit 11, a material information input unit 12, an insulating layer manufacturing information input unit 13, an insulating layer modeling unit 14, an insulating layer equivalent thermal conductivity calculation unit 15, a substrate region dividing unit 16, a wiring area. The ratio calculation unit 17, the wiring layer equivalent thermal conductivity calculation unit 18, the output unit 19, the CAD information data verse 21, the material information database 22, the insulating layer manufacturing information database 23, and the output result database 24 are controlled. Data is transferred and data is processed.

  The board shape information input unit 11 includes a board incorporated in an electronic device, for example, the outer shape of the electronic board, the arrangement and dimensions of the drill holes of the board, the thickness of each wiring layer and insulating layer constituting the electronic board, and the wiring position of the wiring layer And enter information such as dimensions. The material information input unit 12 inputs the thermal conductivity of the metal material and the resin constituting the wiring layer, and the thermal conductivity of a material such as the resin and the filler glass constituting the insulating layer. The insulating layer manufacturing information input unit 13 represents the volume ratio of glass to resin contained in the prepreg or core material of the insulating layer configured as a composite material, and whether the filler is powdery or fibrous. Enter recipe information.

  When the filler such as glass contained in the insulating layer is fibrous, the insulating layer modeling unit 14 includes the manufacturing method information input by the insulating layer manufacturing information input unit 13 and the insulation input by the substrate shape information input unit 11. Model insulation based on information representing the dimensions and arrangement of the layers, and the volume ratio of glass and resin contained in the prepreg or core material of the insulating layer configured as a composite material input by the insulating layer manufacturing information input unit 13 Model into layers. For example, as will be described later with reference to FIG. 5, a model insulating layer having a three-layer structure corresponding to the volume ratio of glass and resin constituting the insulating layer is modeled.

  When the filler such as glass contained in the insulating layer is fibrous, the insulating layer equivalent thermal conductivity calculation unit 15 is based on the thermal conductivity of the material constituting the insulating layer and the material such as glass of the filler. The thermal conductivity of the insulating layer having a three-layer structure modeled by the insulating layer modeling unit 14 is expressed in the in-plane direction of the insulating layer, that is, the direction parallel to the surface of the insulating layer and the in-plane vertical direction (hereinafter referred to as the perpendicular direction). That is, it is calculated for each direction perpendicular to the surface of the insulating layer. When the filler such as glass contained in the insulating layer is in the form of powder, the thermal conductivity of the resin and the filler glass constituting the insulating layer, and the prepreg or core of the insulating layer configured as a composite material Based on the volume ratio of the glass and resin contained in the material, the thermal conductivity averaged by the volume ratio of the resin constituting the insulating layer and the filler such as glass is calculated.

  Substrate area group dividing unit 16 divides the electronic substrate into small area groups, for example, rectangular small areas, for example, portions made of quadrangular columns. The division method into small regions is preferably the same division method as the element division required by computer simulation such as the finite volume method performed using the equivalent thermal conductivity calculated by the present invention, but different divisions. It may be a method. The wiring area ratio calculation unit 17 calculates the wiring area ratio of the area of the wiring pattern occupying the area of the small region for each small region divided by the substrate region group dividing unit 16 for each layer of the wiring layer. The wiring layer equivalent thermal conductivity calculation unit 18 includes the thickness of each layer of the wiring layer input by the substrate shape information input unit 11, the thermal conductivity of the metal material and resin of the wiring layer input by the material information input unit 12, and the wiring Based on the wiring area ratio of each wiring layer for each small region calculated by the area ratio calculation unit 17, the equivalent thermal conductivity of each wiring layer for each small region is calculated.

  The output unit 19 includes an equivalent thermal conductivity of the insulating layer calculated by the insulating layer equivalent thermal conductivity calculator 15 and an equivalent thermal conductivity of each wiring layer calculated for each small region by the wiring layer equivalent thermal conductivity calculator 18. Output rate.

  The CAD information database 21 is data input by the board shape information input unit 11, that is, electronic board outline data designed using a CAD device or the like, board drill hole arrangement and dimension data, and wiring constituting the electronic board. Data such as thickness data of each layer and insulating layer, and wiring position and dimension data of the wiring layer are accumulated. The material information database 22 is data input by the material information input unit 12, that is, data on the thermal conductivity of the metal material and the resin of the wiring layer, and the thermal conductivity of the material such as the resin and the filler glass forming the insulating layer. Accumulate. The insulating layer manufacturing method information database 23 includes data input by the insulating layer manufacturing information input unit 13, that is, volume ratio data between glass and resin contained in the prepreg or core material of the insulating layer, and the filler is powdery. Manufacturing information indicating whether the material is fibrous or not is stored together with the material name data. The output result database 24 accumulates data on the equivalent thermal conductivity of the electronic substrate calculated by the insulating layer equivalent thermal conductivity calculator 15 and the wiring layer equivalent thermal conductivity calculator 18.

  The acquisition unit is, for example, the substrate shape information input unit 11, the material information input unit 12, and the insulating layer manufacturing method input unit 13, and the modeling unit is, for example, the insulating layer modeling unit 14, and calculates the insulating layer equivalent thermal conductivity. The means is, for example, an insulating layer equivalent thermal conductivity calculating unit 15, the dividing means is, for example, a substrate region dividing unit 16, and the wiring area ratio calculating means is, for example, a wiring area ratio calculating unit 17, and the wiring layer equivalent heat is calculated. The conductivity calculating unit is, for example, the wiring layer equivalent thermal conductivity calculating unit 18, and the output unit is, for example, the output unit 19.

  FIG. 2 is a flowchart showing processing steps of a thermal conductivity calculation method according to another embodiment of the present invention. This flowchart shows processing steps performed by the thermal conductivity calculation apparatus 1 shown in FIG. When calculation of the thermal conductivity of the electronic substrate is instructed from the input device of the thermal conductivity calculation device 1, the process proceeds to step S1.

  In step S1, the shape of the board and the wiring shape are acquired. Specifically, information such as the outer shape of the electronic board to be incorporated in the electronic device, the arrangement and dimensions of the drill holes of the board, the thickness of each wiring layer and insulating layer constituting the electronic board, and the wiring position and dimensions of the wiring layer To get. These pieces of information can be acquired from the CAD information database 21 when the electronic board is designed by a CAD apparatus and stored in the CAD information database 21. If not stored in the CAD information database 21, the thermal conductivity calculation device 1 may be connected to the CAD device and directly acquired from the CAD device, or a CAE (Computer Aided Engineering) device for performing thermal fluid analysis It is also possible to connect to a preprocessor and obtain directly from the preprocessor. Or you may make it input directly from an input device and acquire.

  In step S2, material information is acquired. Specifically, information such as the thermal conductivity of the metal material and the resin of the wiring layer and the thermal conductivity of a material such as the resin and the filler glass constituting the insulating layer is acquired. These pieces of information may be acquired from the material information database 22 or may be newly input directly from the input device.

  FIG. 3 schematically shows a cross section of an example of the insulating layer containing the fibrous filler of the electronic substrate to be evaluated. The insulating layer 31a has a configuration in which the resin 32 is infiltrated into one glass cloth. This glass cloth is formed by netting such that a plurality of fibrous glasses 33 intersect the longitudinal direction and the lateral direction in the in-plane direction of the insulating layer. An insulating layer is divided into what is contained in a core material, and a prepreg by the role. A prepreg plays a role of adhesion to other layers such as a core material, and the core material is laminated around a core material in a multilayer substrate laminating process, and a copper foil is laminated on an insulating layer. It has become. The glass cloth of the prepreg is often composed of one sheet, but the insulating layer included in the core material may be composed of a plurality of glass cloths depending on the thickness.

  FIG. 4 schematically shows a cross section of an example of an insulating layer containing a powdery filler for an electronic substrate to be evaluated. Insulating layer 31 b includes powdered glass 34 contained in resin 32.

  Referring to FIG. 2, in step S3, information indicating the volume ratio of glass to resin contained in the insulating layer configured as a composite material, and whether the filler is powdery or fibrous. Get recipe information. When the filler is fibrous, since the ratio vgl of the fibrous glass occupying each insulating layer is expressed by the ratio of the total volume of the plurality of glass cloths occupying each insulating layer, information indicating the volume ratio is acquired. . When the filler is powdery, information representing the volume ratio between the resin 32 and the powdery glass 34 is acquired. These pieces of information are obtained by searching for material names from the insulating layer manufacturing information database 23. If there is no material with the material name in the insulating layer manufacturing method information database 23, the same constituent substance, the same volume ratio, and the same manufacturing method data may be used, or may be newly input from the input device. Good. In the case of newly inputting, information indicating the material name, the volume ratio of the composite material, and the manufacturing method is input. If the newly entered composite material constituent data does not exist in the material information database 22, registration is also performed there.

  In step S4, modeling is performed according to the shape of a filler such as glass contained in the insulating layer. When the filler is fibrous glass, it is modeled as a model insulating layer composed of three flat plates of two resin layers 34 and one glass layer 35 from the volume ratio of glass and resin constituting the insulating layer. To do. If the filler is powdered glass, the process does not require modeling of the layer structure and proceeds to step 6.

FIG. 5 shows an example of an analysis model of the insulating layer containing the fibrous filler shown in FIG. The volume of the modeled model insulating layer is the same as the volume of the actual insulating layer, and the equivalent thickness of each layer of the three-layer flat plate is obtained from the volume ratio of glass to resin. The equivalent thicknesses tep1 and tep2 of the two resin layers 34 of each insulating layer equivalent model and the equivalent thickness tgl of the glass layer 35 are tep1 = l · vep / 2, tgl = l · vgl, and tep2 = l · vep /, respectively. 2 is represented by each formula. Here, l is the actual thickness (m) of each insulating layer, vep is the proportion of resin in each insulating layer, and vgl is the proportion of powdered glass in each insulating layer.

Referring to FIG. 2, in step 5, the equivalent thermal conductivity of the insulating layer is calculated. If the filler is fibrous glass,
From the model insulating layer having the three-layer structure obtained in Step 4, the thermal conductivity λt in the direction perpendicular to the plane is expressed by the following formula:
The thermal conductivity λp in the in-plane direction is given by the following formula: λp = 1 / (tep1 / λep1 + tgl / λgl + tep2 / λep2)
Calculated by Here, l is the actual thickness (m) of each insulating layer, tep1 and tep2 are the equivalent thicknesses (m) of the two resin layers 34 of each insulating layer equivalent model, and tgl is the equivalent thickness of each insulating layer equivalent model. The equivalent thickness (m) and λep of the glass layer 35 are the thermal conductivity (W / mK) of the resin of each insulating layer, and λgl is the thermal conductivity (W / mK) of the glass of each insulating layer.

The thermal conductivity λ of each insulating layer averaged from the volume ratio of glass and resin constituting the insulating layer is expressed by the following formula: λ = λep · vep + λgl · vgl
Calculated by Here, λep is the thermal conductivity (W / mK) of the resin of each insulating layer, λgl is the thermal conductivity (W / mK) of the glass of each insulating layer, and vep is the ratio of the resin in each insulating layer , Vgl is the ratio of powdered glass in each insulating layer.

  The process of step S4 and step S5 is similarly performed for each insulating layer, and the equivalent thermal conductivity of each insulating layer is calculated.

  In step 6, in order to calculate the equivalent thermal conductivity of the wiring layer of the electronic substrate, the shape of the electronic substrate is divided into small region groups, for example, small region groups composed of rectangular small regions. Since the thermal conductivity of the wiring pattern 37 is several thousand times larger than the thermal conductivity of the resin 38, in the wiring layer, the thermal conductivity is increased at locations where the wiring pattern is concentrated and where the wiring pattern is small. The conductivity is very different. If the divided area is large, the flow of heat transmitted from the heating element such as a resistor mounted on the substrate to the substrate is greatly affected. Therefore, it is desirable that the small area is divided finely. When it is desired to reduce the division of the small area, it is preferable that the division is fine when the wiring is thick and concentrated, and the division is large when the wiring is thin and not dense.

  In step 7, a wiring area ratio indicating a ratio of the area of the wiring pattern to the area of the small region is calculated for each small region of each wiring layer.

  FIG. 6 shows an example of the configuration of the electronic substrate that is the object of evaluation. This electronic board is a configuration example of a multilayer board in which wiring layers on which wiring patterns are formed and insulating layers for insulating the wiring patterns from wiring patterns of other wiring layers are alternately stacked. The wiring layer is composed of a wiring material, that is, a wiring pattern 37 and a resin material, that is, a resin 38. Since the thickness of the wiring layer is uniform, the area ratio and the volume ratio are equal.

  Referring to FIG. 2, in step 8, the equivalent thermal conductivity of each wiring layer is calculated. The equivalent thermal conductivity of each small region is calculated from the wiring area ratio for each small region divided in step S7. Using the same method as in the case where the filler obtained in step S5 is powdered glass, the thermal conductivity averaged by the wiring volume ratio is calculated for each small region.

  In step 9, the equivalent thermal conductivity of the insulating layer calculated in step S5 and the equivalent thermal conductivity of each wiring layer for each small region calculated in step S8 are output, and the process ends. The thermal conductivity output at step S9 is also stored in the output result database 24 when it is output.

  Thus, according to the thermal conductivity calculation method of the present invention, first, each insulating layer is modeled as a model insulating layer determined according to the manufacturing method indicated by the manufacturing method information, and the equivalent heat of each model insulating layer thus modeled is modeled. Conductivity is calculated based on material information and thermal conductivity information. Next, based on the substrate shape information, the shape of the substrate, for example, the electronic substrate is divided into predetermined shape portions, and for each wiring layer included in each divided portion, the wiring layer of each portion is determined based on the wiring information. The wiring area ratio that represents the ratio of the area of the wiring pattern to the surface area of the wire is calculated. Based on the calculated wiring area ratio, material information, and thermal conductivity information, the equivalent thermal conductivity for each wiring layer of each part is calculated. Since the calculated equivalent thermal conductivity of each insulating layer and the equivalent thermal conductivity for each wiring layer of each part are output, the thermal conductivity of the substrate depends on the manufacturing method of the insulating layer, that is, the configuration of the insulating layer. Can be calculated. Therefore, more accurate equivalent thermal conductivity of the substrate can be calculated, and more accurate thermal evaluation of the electronic device can be performed.

  Furthermore, if the filler of the insulating layer is a fibrous filler, the insulating layer is modeled as a model insulating layer composed of layers having a layer thickness corresponding to the volume ratio of each constituent material constituting the insulating layer. For each model insulating layer, the equivalent thermal conductivity in the in-plane direction and the equivalent thermal conductivity in the in-plane vertical direction are calculated, so the anisotropy of the thermal conductivity, that is, the surface, for the insulating layer containing the fibrous filler. The thermal conductivity can be calculated in consideration of the difference between the thermal conductivity in the inward direction and the thermal conductivity in the in-plane vertical direction. Therefore, the thermal conductivity of the substrate using the fibrous filler as the filler of the insulating layer can be calculated more precisely, and more accurate thermal evaluation of the electronic device can be performed.

  Furthermore, if the insulating layer filler is a powder filler, the thermal conductivity averaged by the volume ratio of each constituent material constituting the insulating layer is calculated, so the insulating layer containing the powder filler Thermal conductivity can be calculated. Therefore, the thermal conductivity of the substrate using the powder filler as the filler of the insulating layer can be calculated and the electronic device can be thermally evaluated.

  Furthermore, according to the thermal conductivity calculation apparatus 1 according to the present invention, first, each insulating layer is modeled as a model insulating layer determined according to the manufacturing method indicated by the manufacturing method information, and the equivalent heat of each model insulating layer thus modeled is modeled. The conductivity is calculated based on the material information and the thermal conductivity information. Next, based on the substrate shape information, the shape of the substrate is divided into predetermined shape portions, and for each wiring layer included in each divided portion, the surface of the wiring layer of each portion is determined based on the wiring information. A wiring area ratio representing the ratio of the area of the wiring pattern to the area is calculated, and based on the calculated wiring area ratio and material information and thermal conductivity information, an equivalent thermal conductivity for each wiring layer is calculated, In addition, the calculated equivalent thermal conductivity of each insulating layer and the equivalent thermal conductivity of each wiring layer are output, so the thermal conductivity of the substrate is calculated according to the manufacturing method of the insulating layer, that is, the configuration of the insulating layer can do. Therefore, more accurate equivalent thermal conductivity of the substrate can be calculated, and more accurate thermal evaluation of the electronic device can be performed.

  Furthermore, when the filler of the insulating layer is a fibrous filler, the insulating layer is modeled as a model insulating layer having a layer thickness according to the volume ratio of each constituent material constituting the insulating layer. For each model insulating layer, the equivalent thermal conductivity in the in-plane direction and the equivalent thermal conductivity in the in-plane vertical direction are calculated, so the anisotropy of the thermal conductivity for the insulating layer containing the fibrous filler, that is, It is possible to calculate the thermal conductivity in consideration of the difference between the thermal conductivity in the in-plane direction and the thermal conductivity in the in-plane vertical direction. Therefore, the thermal conductivity of the substrate using the fibrous filler as the filler of the insulating layer can be calculated more precisely, and more accurate thermal evaluation of the electronic device can be performed.

  Furthermore, if the insulating layer filler is a powder filler, the thermal conductivity averaged by the volume ratio of each constituent material constituting the insulating layer is calculated, so the heat of the insulating layer containing the powder filler is calculated. Conductivity can be calculated. Therefore, the thermal conductivity of the substrate using the powder filler as the filler of the insulating layer can be calculated and the electronic device can be thermally evaluated.

  The function of the thermal conductivity calculation device 1 shown in FIG. 1 is realized by executing a program stored in the storage device of the thermal conductivity calculation device 1. Further, the processing steps of the thermal conductivity calculation method shown in FIG. 2 are processed by executing the same program. That is, the program stored in the storage device causes the computer to function as each unit of the thermal conductivity calculation device 1 and causes the computer to execute each step of the thermal conductivity calculation method.

  As described above, the computer can function as each unit of the thermal conductivity calculation apparatus 1.

It is a block diagram which shows the structure of the function of the thermal conductivity calculation apparatus 1 which is one Embodiment of this invention. It is a flowchart which shows the process process of the heat conductivity calculation method which is the other form of implementation of this invention. The cross section of an example of the insulating layer containing the fibrous filler of the electronic board | substrate which is evaluation object is shown typically. The cross section of an example of the insulating layer containing the powdery filler of the electronic board | substrate which is evaluation object is shown typically. An example of the analysis model of the insulating layer containing the fibrous filler shown in FIG. 3 is shown. An example of a structure of the electronic substrate which is evaluation object is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermal conductivity calculation apparatus 10 Control part 11 Board | substrate shape information input part 12 Material information input part 13 Insulation layer manufacturing information input part 14 Insulation layer modeling part 15 Insulation layer equivalent thermal conductivity calculation part 16 Board | substrate area | region division part 17 Wiring area ratio Calculation unit 18 Wiring layer equivalent thermal conductivity calculation unit 19 Output unit 21 CAD information data base 22 Material information database 23 Insulating layer manufacturing information database 24 Output result database 30 Electronic substrate 31 Insulating layer 32, 38 Resin 33 Fibrous glass 34 Powdery Glass 35 Glass layer 36 Resin layer 37 Wiring pattern

Claims (5)

Substrate shape information indicating the shape of a substrate in which wiring layers on which wiring patterns are formed and insulating layers for insulating the wiring patterns from wiring patterns of other wiring layers are alternately stacked, and represents the wiring patterns of each wiring layer An acquisition step of acquiring wiring information, material information representing a material constituting the wiring layer and the insulating layer, thermal conductivity information representing the thermal conductivity of each material, and manufacturing information representing a manufacturing method for generating the insulating layer;
A modeling step for modeling each insulating layer into a model insulating layer determined according to the manufacturing method indicated by the manufacturing method information acquired in the acquiring step;
An insulating layer equivalent thermal conductivity calculation step of calculating an equivalent thermal conductivity of each model insulating layer modeled in the modeling step based on the material information and thermal conductivity information acquired in the acquisition step;
Based on the substrate shape information acquired in the acquisition step, a dividing step of dividing the shape of the substrate into a predetermined shape portion;
Based on the wiring information acquired in the acquisition process, for each wiring layer included in each part divided in the dividing process, a wiring area ratio representing the ratio of the area of the wiring pattern to the surface area of the wiring layer of each part A wiring area ratio calculating step to calculate;
Based on the wiring area ratio calculated in the wiring area ratio calculation step and the material information and thermal conductivity information acquired in the acquisition step, the equivalent thermal conductivity for each wiring layer is calculated for each part. A calculation process;
An output step for outputting the equivalent thermal conductivity of each insulating layer calculated in the insulating layer equivalent thermal conductivity calculation step and the equivalent thermal conductivity for each wiring layer calculated in the wiring layer equivalent thermal conductivity calculation step; The thermal conductivity calculation method characterized by including. Substrate shape information indicating the shape of a substrate in which wiring layers on which wiring patterns are formed and insulating layers for insulating the wiring patterns from wiring patterns of other wiring layers are alternately stacked, and represents the wiring patterns of each wiring layer Acquisition means for acquiring wiring information, material information representing a material constituting the wiring layer and the insulating layer, thermal conductivity information representing the thermal conductivity of each material, and manufacturing method information representing a manufacturing method for generating the insulating layer;
Modeling means for modeling each insulating layer into a model insulating layer determined according to the manufacturing method indicated by the manufacturing method information acquired by the acquiring unit;
Insulating layer equivalent thermal conductivity calculating means for calculating the equivalent thermal conductivity of each model insulating layer modeled by the modeling means based on the material information and thermal conductivity information acquired by the acquiring means,
Based on the substrate shape information acquired by the acquisition unit, a dividing unit that divides the shape of the substrate into predetermined shape parts;
Based on the wiring information acquired by the acquiring means, for each wiring layer included in each part divided by the dividing means, a wiring area ratio representing a ratio of the area of the wiring pattern to the surface area of the wiring layer of each part is calculated. A wiring area ratio calculating means for calculating;
Based on the wiring area ratio calculated by the wiring area ratio calculating means and the material information and thermal conductivity information acquired by the acquiring means, the equivalent thermal conductivity for each wiring layer of each part is calculated. A calculation means;
Output means for outputting the equivalent thermal conductivity of each insulating layer calculated by the insulating layer equivalent thermal conductivity calculating means and the equivalent thermal conductivity of each part of the wiring layer calculated by the wiring layer equivalent thermal conductivity calculating means; The thermal conductivity calculation apparatus characterized by including. When the manufacturing method is a manufacturing method using a fibrous filler, the model insulating layer determined according to the manufacturing method is a model insulating layer composed of a layer having a layer thickness corresponding to the volume ratio of each constituent material constituting the insulating layer,
The insulating layer thermal equivalent conductivity calculating means, when the filler of the insulating layer indicated by the material information acquired by the acquiring means is a fibrous filler, for each model insulating layer modeled by the modeling means The thermal conductivity calculation device according to claim 2, wherein an equivalent thermal conductivity in an in-plane direction and an equivalent thermal conductivity in an in-plane vertical direction are calculated.   The insulating layer thermal equivalent conductivity calculating means averages the volume ratio of each constituent material constituting the insulating layer when the filler of the insulating layer indicated by the material information acquired by the acquiring means is a powder filler. The thermal conductivity calculation device according to claim 2, wherein the calculated thermal conductivity is calculated.   The program for functioning a computer as each means of the thermal conductivity calculation apparatus of Claim 2.

Images