JP2011133990A - Voltage drop calculation device, calculation method, and calculation program, for printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that voltage drop of a power supply line pattern 12 is not easily detected in designing a circuit pattern in a printed wiring board. <P>SOLUTION: A voltage drop calculation part 35 which calculates the voltage drop of power supply line based on a power supply line pattern extracted from a circuit pattern created based on information related with circuit arrangement including signal wiring, power supply line, vias, clearance holes and components configuring a printed circuit board defines a value calculated by subtracting a value calculated by totaling the diameters of the clearance holes aligned in a row vertical to a direction in which currents existing in the power supply line pattern are running from the width of the power supply line pattern as the valid wiring width of the power supply line pattern, and calculates the voltage drop of the power supply line by calculating the resistance value of the power supply line based on the valid wiring width of the power supply line pattern. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a voltage drop calculation device, calculation method, and calculation program for a printed wiring board, and more particularly, a voltage drop calculation device, calculation method, and calculation program for a printed wiring board capable of efficiently calculating a voltage drop in a power supply wiring. About.

  Designers involved in the development of electronic equipment first set the width of the power supply wiring corresponding to the amount of current to flow when designing the circuit. Automatic design tools used by many designers generate power supply wiring to automatically pass through vias. The via is for electrically connecting the upper layer wiring and the lower layer wiring. Therefore, the automatic design tool automatically generates a clearance hole during power supply wiring. When the circuit designer confirms the design data after the execution of the automatic design tool, there may be many clearance holes in the power supply wiring pattern, and this phenomenon is often caused by the power supply wiring corresponding to the amount of current to flow. This is because the width is not secured.

  The clearance hole is a region in the multilayer printed wiring board in which no conductor is provided in a portion surrounding the through hole so that the inner layer conductor pattern is not electrically connected to the plated through hole and via. When a signal wiring via is arranged in the power wiring pattern, a portion where a hole is formed in the power wiring pattern becomes a clearance hole. The clearance hole narrows the width of the power supply wiring pattern through which the current flows and narrows the path through which the current flows.

  In recent years, since the propagation speed of signals is increasing day by day, the core voltage of LSIs has been lowered and increased in current. In order to handle a low voltage and a high current, it is expected that the voltage drop between the power supply and the core voltage supply pin of the LSI is minimized. Therefore, sufficient care is required for the arrangement of the clearance holes.

  Related techniques include the following patent documents. In Patent Document 1, in a substrate CAD (Computer-aided design) system, a cut figure input by a cut figure input unit on a screen on which a wiring layer is formed damages an original wiring layer pattern or land. It is possible to easily and surely recognize whether or not there is, and it is possible to input appropriate cut figures, reduce human errors, improve the work efficiency of using cut information, and improve board creation efficiency And a technology that can reduce the occurrence rate of defective products.

  Patent Document 2 discloses a technique for extracting land data of a wiring from a wiring pattern of a multilayer wiring board, automatically generating a clearance with a neighboring wiring, and adding it to the wiring pattern data.

  Patent Document 3 automatically calculates and checks the wiring width of a wiring pattern on the printed circuit board that has a defined current value, thereby eliminating the check man-hours and improving the design quality. Techniques to do this are disclosed.

JP2001-155044 JP-A-3-185343 Japanese Patent Laid-Open No. 5-94498

  However, the printed wiring board design apparatus described above has the following problems. The printed wiring board design CAD system did not have a function of verifying a voltage drop due to the power wiring pattern. For this reason, it is visually confirmed whether or not the width of the power supply wiring pattern through which the current flows satisfies the current value and the voltage drop. Specifically, for each of a large number of power supply wiring patterns, the narrowest part that becomes a bottleneck of current flow was visually examined. We visually examined how clear clearance holes were installed and where the clearance holes were dense. Therefore, there is a problem that much time and labor are required.

In recent printed wiring board designs, the number of power supplies and the number of power supply types are increasing. For this reason, in the visual confirmation, there is a problem that a place error or a check omission occurs, so that a delay in development delivery time, an increase in cost, and a decrease in design quality occur, and stable design quality cannot be provided.
On the other hand, dedicated software is required to automatically verify the voltage drop due to the power supply wiring pattern. In order to use such software, technical skills are required, and it takes time and effort to execute the software.

  Furthermore, Patent Document 1 described above is a technique for inputting an appropriate cut figure to a screen on which a wiring layer is formed in a board design system, and the above-mentioned problem is not solved at all.

  Patent Document 2 is a technique for extracting wiring land data from a wiring pattern of a multilayer wiring board and automatically generating a clearance with a neighboring wiring and adding it to the wiring pattern data. The problem is not solved at all.

  Further, Patent Document 3 is a technique for automatically calculating and checking the wiring width of a wiring having a regulation of a flowing current value among wiring patterns on a printed circuit board, and the above problem is solved at all. is not.

[Object of invention]
The present invention provides a voltage drop calculation device for a printed wiring board capable of effectively and quickly calculating a power supply voltage drop in the power supply wiring pattern without taking time and effort when creating a circuit pattern of the printed wiring board, The purpose is to provide a calculation method and a calculation program.

In order to achieve the above object, a voltage drop calculation device for a printed wiring board according to the present invention includes:
Input means for inputting information related to circuit arrangement of signal wiring, power supply wiring, vias, clearance holes and components constituting the printed wiring board, and connection information and component library are extracted from the inputted circuit arrangement information based on this A circuit pattern creating means for creating a circuit pattern, a power supply wiring pattern whose energization direction is specified from the created circuit pattern, a clearance hole formed on the power supply wiring pattern, and a clearance hole extracting unit for extracting the position thereof; A power supply wiring width calculation unit for calculating an effective wiring width on the power supply wiring pattern in the extracted clearance hole portion, and calculating a voltage drop in the power supply wiring portion based on the calculated effective wiring width A voltage drop calculation unit that performs power supply wiring width calculation on the power supply wiring pattern. In calculating the effective wiring width, a function of identifying the clearance holes arranged in a line along the energization width direction orthogonal to the energization direction on the power supply wiring pattern, and each of the identified clearance holes An effective wiring width calculation function for calculating a total value of diameters and a value obtained by subtracting the total value from the width of the power supply wiring pattern and using this as an effective wiring width of the power supply wiring pattern in a portion where the clearance hole exists It is characterized by having.

In order to achieve the above object, the voltage drop calculation method for the printed wiring board according to the present invention is as follows.
The input means inputs information related to the circuit layout of signal wiring, power supply wiring, vias, clearance holes, and components constituting the printed wiring board, and extracts connection information and a component library from the input circuit layout information. The circuit pattern creating means creates a circuit pattern based on the power supply wiring pattern in which the energization direction is specified from the created circuit pattern, the clearance hole existing on the power supply wiring pattern, and the position thereof. Is extracted, and the effective wiring width on the power supply wiring pattern in the extracted clearance hole portion is calculated, and the voltage drop calculation unit calculates the voltage drop in the power supply wiring portion based on the calculated effective wiring width. It is characterized by that.

Further, in order to achieve the above object, a voltage drop calculation program for a printed wiring board according to the present invention includes:
Connection information and a component library are extracted from signal wiring, power supply wiring, vias, clearance holes, and information relating to the circuit layout of components that are input via the input means, and a circuit pattern is created based on the extracted information. Circuit pattern creation function, clearance hole extraction function to extract the position of the clearance hole existing on the power supply wiring pattern and the power supply wiring pattern in which the energization direction is specified from the created circuit pattern, and in the extracted clearance hole portion A voltage drop calculation function for calculating an effective wiring width on the power supply wiring pattern and calculating a voltage drop in the power supply wiring portion based on the calculated effective wiring width; When calculating the effective wiring width on the wiring pattern, A specific processing function for identifying the clearance holes arranged in a line along the energization width direction orthogonal to the energization direction, and a total value and a total value of the diameters of the identified clearance holes. An effective wiring width calculation function for calculating a value subtracted from the width of the power supply wiring pattern and using this as the effective wiring width of the power supply wiring pattern in the portion where the clearance hole exists is provided to the computer. It is characterized by that.

  The present invention provides a printed wiring board design apparatus, a design method thereof, and a design thereof having an excellent effect of being able to easily detect a voltage drop of a power supply wiring pattern when designing a circuit pattern on the printed wiring board. Can provide a program.

It is a block diagram which shows one Embodiment of the voltage drop calculation apparatus of the printed wiring board of this invention. It is a flowchart which shows operation | movement of the voltage drop calculation apparatus of the printed wiring board in embodiment disclosed in FIG. FIG. 3 is an explanatory diagram showing an example of a power supply wiring pattern connected to an LSI used for calculating a voltage drop in FIG. 2 and a clearance hole existing in the power supply wiring pattern. FIG. 6 is an explanatory diagram (part 1) illustrating another example of a basic clearance hole existing in the power supply wiring pattern portion disclosed in FIG. 2; FIG. 3 is an explanatory diagram (No. 2) illustrating an example of a basic clearance hole existing in the power supply wiring pattern portion disclosed in FIG. 2.

The present invention, when designing the circuit pattern of the printed wiring board, the value obtained by subtracting the total diameter of clearance holes present in the power wiring pattern from the width of the power wiring pattern is the effective width of the actual power wiring pattern, It is characterized in that the voltage drop is calculated by calculating the resistance value of the power supply wiring based on the power supply wiring pattern width, and the configuration capable of executing such arithmetic processing is specified.
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 4.

(Overall configuration)
FIG. 1 shows a block diagram of a voltage drop calculation device for a printed wiring board in the present embodiment.
In FIG. 1, the voltage drop calculation device for a printed wiring board is used to input information related to circuit arrangement including signal distribution wiring, power supply wiring, vias, clearance holes and components constituting the printed wiring board, and an instruction from an operator. Means 21, circuit arrangement storage means 22 for storing inputted circuit arrangement information, circuit pattern generation means 25 for generating a circuit pattern from the circuit arrangement information, circuit pattern storage means 23 for storing this circuit pattern, Based on the result of the voltage drop calculation, the data management means 24 for managing the circuit arrangement storage means 22 and the circuit pattern storage means 23, the voltage drop calculation means 26 for calculating the voltage drop of the power supply wiring from the circuit pattern, The power supply wiring determining means 27 for determining whether or not the input voltage fluctuation allowable value is satisfied, and the determined connection And a display unit 28 for displaying.

  Among these, the input means 21 inputs CAD (Computer Aided Design, circuit arrangement support by computer) data and an instruction from an operator. Further, the input means 21 specifically includes a keyboard or mouse directly operated by an operator, a liquid crystal display for displaying an input status, an input device of an optical disk device or a magnetic storage disk device recording a large amount of data, It consists of devices that can be connected to other computers.

  The circuit arrangement storage unit 22 stores the circuit arrangement information input from the input unit 21 under the control of the data management unit 24. When there is a request from the circuit pattern creation means 25, the voltage drop calculation means 26, and the power supply wiring correction means 27, the data management means 24 operates the circuit arrangement information, and the circuit arrangement information is obtained. Supply to each means.

The circuit pattern creation unit 32 inputs the layer type data such as the type of board required when designing the printed wiring board input from the input means 21, the conductor thickness to be used, the insulator thickness and the material type, and the tolerance of voltage fluctuation in the power supply wiring pattern. Create a circuit pattern from the values. The created circuit pattern is stored in the circuit pattern storage unit 23 through the data management unit 24.
The circuit pattern creation means 25 includes a board information extraction unit 31 that extracts the connection information between components and the component library from the circuit arrangement, and a circuit pattern creation unit that creates a circuit pattern based on the extracted information. 32.

  The circuit pattern storage unit 23 stores the data through the data management unit 24 created by the circuit pattern creation unit 25.

  The data management unit 24 manages the circuit arrangement storage unit 22 and the circuit pattern storage unit 23, and transmits and receives data. When there is a request for information from the circuit pattern creation means 25, the voltage drop calculation means 26, the power supply wiring correction means 27, and the circuit arrangement storage means 22, the data management means 24 takes out the information, Supply to the means.

  The voltage drop calculation means 26 calculates a voltage drop in the power supply wiring pattern. The power drop calculation means 26 includes a clearance hole extraction unit 33 for extracting a power supply wiring pattern and a clearance hole from the circuit pattern, and a power supply wiring for calculating an effective power supply wiring width based on the dimensions of the power supply wiring and the clearance hole. The width calculation unit 34 includes a voltage drop calculation unit 34 that calculates a voltage drop based on the effective power supply wiring width.

Among these, the clearance hole extraction unit 33 extracts the coordinates and outline of the power supply wiring pattern 12 and the coordinates and outline of the clearance hole 11 existing in the power supply wiring pattern 12 from the circuit pattern. The extracted data is sent to the power supply wiring width calculation unit 34.
The power supply wiring width calculation unit 34 calculates a new power supply wiring width based on the extracted coordinates and outline of the power supply wiring pattern 12 and the coordinates and outline of the clearance hole 11 existing in the power supply wiring pattern 12.

The voltage drop calculation unit 35 calculates the voltage drop amount of the power supply wiring from the new power supply wiring pattern. The calculation result is sent to the voltage drop determination means 27.
The voltage drop determination means 27 receives the voltage drop amount from the voltage drop calculation unit 35 and determines whether the voltage drop amount satisfies the voltage fluctuation allowable value.

  The display means 28 displays the result of the determination and displays the information and processing status in each storage unit. The display unit 30 is configured with a liquid crystal display.

(Overall operation)
Next, the overall operation of the above embodiment will be described with reference to FIGS. Here, FIG. 2 is a flowchart showing the operation of the printed wiring board design apparatus according to the present embodiment disclosed in FIG.
The circuit arrangement is stored in advance in the circuit arrangement storage means 22 from the input means 21 through the data management means 24. The board information extraction unit 31 obtains the circuit arrangement from the circuit arrangement storage means 22 through the data management means 24 and, based on the circuit arrangement, a net list (connection information between components) and a footprint (terminals on the printed board). A conductor pattern in which small square pads gathered for mounting many surface-mounted components) and a component library are extracted. These data are the source data of the printed wiring board (design basis data). The extracted result is sent to the circuit pattern creation unit 32 (step S101 / connection information / component library extraction step).

  Next, the circuit pattern creation unit 32 creates a circuit pattern based on the connection information between the components and the component library. The circuit pattern creation process is performed from step S102 to step S106 as described below.

Based on the component library and the footprint, component placement for arranging footprints on a printed circuit board is performed. The arranged result data is stored in the circuit pattern storage means 23 through the data management means 24 (step S102 / component placement step).
The type of board for designing the printed wiring board is set, and the layer configuration of the conductor thickness, insulator thickness and material type to be used is input from the input means 21 and stored in the circuit pattern storage means 23 (step S103 / layer) Configuration setting process).

  The input means 21 inputs the maximum current value and the allowable voltage fluctuation value in the power supply wiring pattern, and stores them in the circuit pattern storage means 23 (step S104 / power supply wiring parameter input process).

  The circuit pattern creation means 25 creates a signal wiring pattern based on the connection information stored in the circuit pattern storage means 23 (step S105 / signal wiring pattern creation step).

  The circuit pattern creation means 25 creates a power supply wiring pattern based on the connection information stored in the circuit pattern storage means 23 (step S106 / power supply wiring pattern creation step).

  Next, the clearance hole extraction unit 33 extracts a power supply wiring pattern from this circuit pattern and checks its voltage drop. The power supply wiring automatic check flow 41, which is this series of flows, will be described below.

  Further, the clearance hole extraction unit 33 selects the power supply wiring pattern in which the electrical specifications are input and set in step S104 (power supply wiring parameter input process) (step S107 / power supply wiring pattern selection process).

  Further, the clearance hole extraction unit 33 extracts coordinates constituting the shape of the selected power supply wiring pattern (step S108 / power supply wiring pattern extraction step).

  The clearance hole extraction unit 33 picks up the coordinates and diameter of the clearance hole on the power supply wiring pattern (step S109 / clearance hole extraction step).

  The power wiring width calculator 34 calculates the width of the power wiring pattern that minimizes the position where the clearance hole exists (step S110 / power wiring pattern width calculation step).

  Further, the power supply wiring width calculation unit 34 subtracts the clearance diameter from the width of the power supply wiring pattern obtained in step S110, and calculates the pattern width in which the current actually flows (step S111 / current passing pattern width calculation process).

  The voltage drop calculation unit 35 calculates the voltage drop in the portion where the clearance hole exists (step S112 / voltage drop calculation step).

  The voltage drop determination means 27 determines whether the calculation result of the voltage drop satisfies the voltage fluctuation allowable value. If the calculation result of the voltage drop does not satisfy the allowable value of the voltage fluctuation, the process returns to the power supply wiring flow in step S106, and the power supply wiring pattern is recreated. If the calculation result of the voltage drop satisfies the allowable value of the voltage fluctuation, the process ends (step S113 / voltage drop determination step).

  Next, steps S111 (current passage pattern width calculation step) and step S112 (voltage drop calculation step) will be described with reference to FIGS. 3 to 5 using specific power supply wiring patterns.

  First, an actual power supply wiring pattern will be described with reference to FIG. A power supply wiring pattern 12 is connected to the power supply terminal of the LSI 10 in order to supply power from the output terminal 13 of the power supply IC 14. Here, the package of the LSI 10 is assumed to be a BGA (Ball Grid Array). The clearance hole 11 often occurs under the LSI 10 or in a wiring pattern between the LSI 10 and the power supply IC.

Next, the simplest clearance hole arrangement shape will be described with reference to FIG. 4, and an example in which the voltage drop calculation unit 35 calculates the pattern width at the position where the clearance hole exists (step S111 / current passing pattern width calculation step). ) And an example of calculating the voltage drop (step S112 / voltage drop calculation step) will be described.
Since the current flow direction 16 is from right to left in FIG. 4 with respect to the power supply wiring pattern width 15 in FIG. 4, the power supply wiring pattern width 15 (hereinafter referred to as W) is the vertical distance. Become. Assuming that the diameter of the clearance hole 11 is D, since the three clearance holes 11 are arranged vertically, the effective width through which the current flows is “W−3 × D”. A value obtained from “W−3 × D” is newly set as a symbol Wa (step S111 / current passing pattern width calculation step).

The length of the power supply wiring is from the center of the clearance hole to the power supply terminal of the LSI. Based on the following formula (1), the resistance value of the power supply wiring from the clearance hole to the power supply terminal of the LSI is calculated (step S112 / voltage drop calculation step).

R = ρ · (L / A) [Ω] Equation (1)

In Equation (1), R represents a resistance value [Ω], ρ represents a resistivity [Ω · m], a length of an L conductor [m], and A represents a cross-sectional area [m ² ] of the conductor. The resistivity ρ varies depending on the conductor material, but in the case of a printed wiring board, 1.7241 × 10 ⁻⁸ Ω · m is used for copper.

  If the effective width in which the current in the area where the clearance hole 11 exists is set to Wa, the conductor thickness is set in step S103, and the length is set to the diameter of the clearance hole 11, the resistance value of the power supply wiring can be easily set. Can be calculated.

  Finally, a corresponding example when the clearance holes 11 are arranged in a plurality of rows will be described with reference to FIG. It can be divided into three rows and two rows in the vertical direction. The voltage drop due to the clearance hole 11 in FIG. 5 can be easily calculated by adding the voltage drop of the row in which three clearance holes 11 are arranged in the vertical direction and the voltage drop in the row of two rows.

(Effect of embodiment)
In the present embodiment, when designing a circuit pattern on a printed wiring board, an area where the clearance hole 11 exists in the power wiring pattern 12 is extracted, and the wiring width of the power wiring pattern 12 is simplified and set. It is possible to detect a voltage drop of the power supply wiring pattern 12 and confirm whether the voltage drop is the minimum. Therefore, by minimizing errors in the location, calculation errors, and check omissions that have occurred during visual confirmation, it is possible to provide a stable and high design quality without causing delays in development and cost increases. Have.
In addition, since the present invention sets the specifications of the power supply wiring pattern in the CAD, the specification confirmation time can be shortened, and since it is automated by the CAD, there is an excellent effect that confirmation can be performed in a short time. .

  As described above, in the present embodiment, by simplifying and setting the wiring width of the power supply wiring pattern 12, the voltage drop of the power supply wiring pattern 12 can be easily detected. It has an excellent effect of providing stable and high design quality without causing delays in delivery and cost increases.

DESCRIPTION OF SYMBOLS 11 Clearance hole 12 Power supply wiring pattern 21 Input means 22 Circuit arrangement storage means 23 Circuit pattern storage means 24 Data management means 25 Circuit pattern creation means 26 Voltage drop calculation means 27 Voltage drop determination means 28 Display means 31 Substrate information extraction part 32 Circuit pattern Creation unit 33 Clearance hole extraction unit 34 Power supply wiring width calculation unit 35 Voltage drop calculation unit

Claims (7)

Input means for inputting information related to circuit arrangement of signal wiring, power supply wiring, vias, clearance holes and components constituting the printed wiring board, and connection information and component library are extracted from the inputted circuit arrangement information based on this A circuit pattern creating means for creating a circuit pattern, a power supply wiring pattern whose energization direction is specified from the created circuit pattern, a clearance hole formed on the power supply wiring pattern, and a clearance hole extracting unit for extracting the position thereof; Have
A power supply wiring width calculation unit for calculating an effective wiring width on the power supply wiring pattern in the extracted clearance hole portion, and a voltage drop calculation for calculating a voltage drop in the power supply wiring portion based on the calculated effective wiring width With
The power wiring width calculation unit
In calculating the effective wiring width on the power supply wiring pattern, the function of specifying the clearance holes arranged in a line along the energization width direction orthogonal to the energization direction on the power supply wiring pattern, and this specification The total value of the diameters of the clearance holes and the value obtained by subtracting the total value from the width of the power supply wiring pattern are calculated and this is used as the effective wiring width of the power supply wiring pattern in the portion where the clearance hole exists. A voltage drop calculation device for a printed wiring board, comprising a wiring width calculation function. In the voltage drop calculation apparatus of the printed wiring board according to claim 1,
The circuit pattern creating means;
A board information extraction unit that extracts connection information and a component library from the input circuit arrangement information, and a circuit pattern generation unit that generates a circuit pattern based on the extracted connection information and the component library, A voltage drop calculation device for printed wiring boards. In the voltage drop calculation apparatus of the printed wiring board according to claim 2,
A circuit arrangement storage unit for storing the circuit arrangement information input via the input unit, and a circuit pattern storage unit for storing the circuit pattern information created by the circuit pattern creation unit;
A voltage drop calculation device for a printed wiring board, wherein a data management means for controlling the storage operation of each storage section is provided in the input means and the circuit pattern creation means. The input means inputs the information related to the signal distribution wiring, power supply wiring, vias, clearance holes and circuit arrangement of the components constituting the printed wiring board,
The circuit pattern creation means creates a circuit pattern based on the connection information and the component library extracted from the inputted circuit layout information,
The clearance hole extraction unit extracts the power supply wiring pattern in which the energization direction is specified from the created circuit pattern, the clearance hole existing on the power supply wiring pattern, and the position thereof,
An effective wiring width on the power supply wiring pattern in the extracted clearance hole portion is calculated, and a voltage drop calculation unit calculates a voltage drop in the power supply wiring portion based on the calculated effective wiring width. To calculate voltage drop of printed wiring board. In the voltage drop calculation method of the printed wiring board according to claim 4,
In the process of calculating the effective wiring width on the power wiring pattern,
The clearance holes arranged in a line along the energization width direction perpendicular to the energization direction on the power supply wiring pattern are identified, and the total value of the diameters of the identified clearance holes and the total value are determined. A method of calculating a voltage drop of a printed wiring board, wherein a value subtracted from the width of the power wiring pattern is calculated, and the subtracted value is set as an effective wiring width of the power wiring pattern in a portion where the clearance hole exists . Connection information and a component library are extracted from signal wiring, power supply wiring, vias, clearance holes, and information relating to the circuit layout of components that are input via the input means, and a circuit pattern is created based on the extracted information. Circuit pattern creation function,
A clearance hole extraction function for extracting the position of the power supply wiring pattern whose energization direction is specified from the created circuit pattern and the clearance hole existing on the power supply wiring pattern,
A voltage drop calculation function for calculating an effective wiring width on the power supply wiring pattern in the extracted clearance hole portion and calculating a voltage drop in the power supply wiring portion based on the calculated effective wiring width is provided.
The power wiring width calculation function is
In calculating the effective wiring width on the power supply wiring pattern, a specific processing function for specifying the clearance holes arranged in a line along the energization width direction orthogonal to the energization direction on the power supply wiring pattern, and The total value of the diameters of the identified clearance holes and the value obtained by subtracting the total value from the width of the power supply wiring pattern are calculated and this is calculated as the effective wiring width of the power supply wiring pattern in the portion where the clearance hole exists. With effective wiring width calculation function
A program for calculating a voltage drop in a printed wiring board, characterized in that these are realized by a computer. In the printed circuit board voltage drop calculation program according to claim 6,
A storage processing function for storing and processing the circuit arrangement information input via the input means in a circuit arrangement storage means, and a circuit for storing and processing the circuit pattern information created by the circuit pattern creation unit in the circuit pattern storage means A pattern memory processing function is provided.
A program for calculating a voltage drop of a printed wiring board, wherein each of the storage processing functions is realized by the computer.

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