JP4453433B2 - Bypass capacitor arrangement information acquisition apparatus and method - Google Patents

Description

  The present invention is necessary for optimally arranging bypass capacitors for measures against EMI (electro-magnetic interference) on a substrate on which an integrated circuit such as an LSI (large scale integrated circuit) is mounted. The present invention relates to a bypass capacitor arrangement information acquisition apparatus and method for acquiring various information.

  In recent years, the EMI noise problem has become apparent. The EMI noise is a power supply noise that is a fluctuation of a power supply voltage inside the integrated circuit propagates to the power supply wiring of the board on which the integrated circuit is mounted, and the power supply noise is radiated to the space as an electromagnetic wave by the function of the antenna of the power supply wiring of the board. It is a phenomenon. In the future, with the increase in the speed of integrated circuits, the increase in the number of pins, and the increase in current, the power supply noise tends to increase further, which means that the EMI noise increases.

  In each major country, there is an EMI standard that defines an upper limit for EMI noise generated from electronic equipment, and it is obliged to satisfy this EMI standard. For example, the VCCI standard exists in Japan, the EN standard exists in the EU, and the FCC standard exists in the United States. Import and sales of devices that do not satisfy these standards are prohibited.

  As a measure against EMI, generally, a method of arranging a bypass capacitor on a substrate is used. As a method of determining a location of a bypass capacitor, for example, when designing a substrate, a bypass capacitor is appropriately arranged in the vicinity of an integrated circuit. There is a method of determining the location of the bypass capacitor that can satisfy the EMI standard by repeatedly checking the EMI noise by actual measurement after the design and re-designing the substrate accompanying the addition of the bypass capacitor.

However, in such a follow-up EMI countermeasure, the EMI countermeasure period is as long as several months, and the EMI countermeasure cost becomes a heavy burden. Therefore, conventionally, a method has been proposed in which the validity of the location of the bypass capacitor is simply determined based on the voltage determination of the power supply noise using a simple calculation formula (see, for example, Patent Document 1).
JP 2002-140382 A

  In order to optimally place a bypass capacitor on a substrate on which an integrated circuit is mounted, a frequency having an effective frequency characteristic for EMI countermeasures is specified at a place effective for EMI countermeasures after specifying a frequency that requires EMI countermeasures. Need to be placed. However, the technique described in Patent Document 1 is not such a problem, and the technique described in Patent Document 1 has a problem that the EMI countermeasure period becomes long and the EMI countermeasure cost increases.

  In view of this point, the present invention effectively performs optimal placement of a bypass capacitor with respect to a substrate on which an integrated circuit is mounted, shortens the EMI countermeasure period, and reduces the EMI countermeasure cost. An object is to provide an arrangement information acquisition apparatus and method.

  The bypass capacitor arrangement information acquisition apparatus of the present invention has EMI countermeasure frequency determining means for determining a frequency that requires EMI countermeasure from the analysis result of EMI noise generated by the substrate.

  The bypass capacitor arrangement information acquisition method of the present invention is such that the EMI countermeasure frequency determining means has an EMI countermeasure frequency determining step of determining a frequency that requires EMI countermeasure from the analysis result of the EMI noise generated by the substrate.

  According to the bypass capacitor arrangement information acquiring apparatus of the present invention, the EMI countermeasure frequency information can be acquired as one of the bypass capacitor arrangement information by the EMI countermeasure frequency determining means. Further, according to the bypass capacitor arrangement information acquisition method of the present invention, the EMI countermeasure frequency information can be acquired as one of the bypass capacitor arrangement information by the EMI countermeasure frequency determination step.

  Therefore, in addition to the EMI countermeasure frequency information acquired by the present invention, for example, it is possible to obtain a power supply terminal that requires an EMI countermeasure by acquiring a power supply terminal current waveform of the integrated circuit. In addition, by preparing a bypass capacitor database including resonance frequency, impedance information, and the like, it is possible to determine a bypass capacitor having frequency characteristics optimal for the EMI countermeasure frequency.

  Therefore, according to the present invention, it is possible to effectively arrange the bypass capacitor with respect to the substrate on which the integrated circuit is mounted, shorten the EMI countermeasure period, and reduce the EMI countermeasure cost.

  FIG. 1 is a conceptual diagram of an embodiment of a bypass capacitor arrangement information acquisition apparatus according to the present invention. One embodiment of the bypass capacitor arrangement information acquisition apparatus of the present invention can be configured by a computer having a CPU and a memory. .

  In FIG. 1, reference numeral 1 denotes a specific countermeasure frequency holding means, which holds a frequency that is specified in advance as a specific countermeasure frequency for performing EMI countermeasures. Reference numeral 2 denotes EMI noise analysis result holding means, which is a result of analyzing EMI noise generated by a substrate on which an LSI is mounted using a substrate model obtained by modeling a substrate on which an LSI is mounted (frequency distribution of the magnitude of EMI noise). ). Reference numeral 3 denotes EMI standard holding means, which holds the contents of the EMI standard.

  Reference numeral 4 denotes EMI countermeasure frequency determination means, which is a specific countermeasure frequency held by the specific countermeasure frequency holding means 1, an EMI noise analysis result held by the EMI noise analysis result holding means 2, and an EMI standard held by the EMI standard holding means 3. , And a frequency that requires EMI countermeasures is determined as an EMI countermeasure frequency. Reference numeral 5 denotes an EMI countermeasure frequency holding means for holding the EMI countermeasure frequency determined by the EMI countermeasure frequency determining means 4.

  The EMI countermeasure frequency determination means 4 includes an EMI countermeasure frequency calculation unit 6 and an EMI countermeasure frequency output unit 7. The EMI countermeasure frequency calculation unit 6 compares the EMI noise analysis result input from the EMI noise analysis result holding means 2 with the EMI standard input from the EMI standard holding means 3, and determines all frequencies exceeding the EMI standard as EMI countermeasures. It is calculated as a frequency.

  The EMI countermeasure frequency output unit 7 determines the EMI countermeasure frequency calculated by the EMI countermeasure frequency calculation unit 6 and the specific countermeasure frequency input from the specific countermeasure frequency holding unit 1 as the EMI countermeasure frequency, and supplies these to the EMI countermeasure frequency holding unit 5. Output.

  Reference numeral 8 denotes power source terminal current waveform holding means, which uses an LSI model obtained by modeling an LSI mounted on a substrate as a simulation model, and uses the power source terminal among the external terminals of the LSI (a power pin when the LSI is packaged) In the case of not being packaged, the waveform of the current flowing in the power supply pad) is held.

  Reference numeral 9 denotes an EMI countermeasure power supply terminal determining means, which inputs the EMI countermeasure frequency held by the EMI countermeasure frequency holding means 5 and the current waveform of the power supply terminal of the LSI held by the power supply terminal current waveform holding means 8 and requires EMI countermeasures. The power supply terminal is determined.

  Reference numeral 10 denotes an EMI countermeasure power terminal number / optimum bypass capacitor type holding means, and for each EMI countermeasure frequency, the number of the EMI countermeasure power terminal determined by the EMI countermeasure power terminal determining means 9 and the optimum bypass capacitor determining means described later are determined. The type of the optimum bypass capacitor is maintained.

  The EMI countermeasure power supply terminal determining means 9 includes a current amplitude frequency distribution calculating section 11, a current amplitude extracting section 12, and an EMI countermeasure power supply terminal calculating section 13. The current amplitude frequency distribution calculation unit 11 calculates the frequency distribution of the current amplitude of the current flowing through each power supply terminal by Fourier transforming the current waveform of each power supply terminal input from the power supply terminal current waveform holding means 8.

  The current amplitude extraction unit 12 extracts the current amplitude of the EMI countermeasure frequency component from the current amplitude frequency distribution of the current flowing through each power supply terminal calculated by the current amplitude frequency distribution calculation unit 11 from among the current components flowing through each power supply terminal. To do.

  The EMI countermeasure power supply terminal calculation unit 13 calculates the EMI countermeasure frequency component of each power supply terminal for each EMI countermeasure frequency from the current amplitude of the EMI countermeasure frequency component of the current flowing through the power supply terminal extracted by the current amplitude extraction unit 12. Is calculated as an EMI countermeasure power supply terminal and is output to the EMI countermeasure power supply terminal number / optimum bypass capacitor type holding means 10.

  Reference numeral 14 denotes a bypass capacitor database. As shown in FIG. 2, for example, as shown in FIG. 2, a plurality of bypass capacitors that can be used are part number, capacitance, parasitic inductance (ESL: equivalent series inductance), parasitic resistance (ESR: equivalent series). resistance) and resonance frequency as a database.

  Numeral 15 is an optimum bypass capacitor determination means, which inputs the EMI countermeasure frequency held by the EMI countermeasure frequency holding means 5, and from the bypass capacitor in the bypass capacitor database 14, the EMI countermeasure frequency is the highest for each EMI countermeasure frequency. A bypass capacitor having a low impedance is determined as the optimum bypass capacitor.

  The optimum bypass capacitor determination unit 15 includes an impedance calculator 16 and an optimum bypass capacitor calculator 17. The impedance calculation unit 16 calculates the frequency of the bypass capacitor in the bypass capacitor database 14 from the capacitance, parasitic inductance, and parasitic resistance for each EMI countermeasure frequency at the EMI countermeasure frequency of each bypass capacitor in the bypass capacitor database 14. Impedance is calculated.

  The optimum bypass capacitor calculating unit 17 compares the impedance of each bypass capacitor for each EMI countermeasure frequency, calculates the bypass capacitor having the lowest impedance as the optimum bypass capacitor for the EMI countermeasure, This is output to the bypass capacitor type holding means 10.

  FIG. 3 is a conceptual diagram of an example of an apparatus for acquiring a power supply terminal current waveform and an EMI noise analysis result. In FIG. 3, reference numeral 18 denotes an LSI model holding means for holding an LSI model obtained by modeling an LSI mounted on a substrate, and 19 denotes a power supply terminal current waveform for acquiring a power supply terminal current waveform from the LSI model held by the LSI model holding means 18. It is an acquisition means (for example, circuit analysis simulator).

  Reference numeral 20 denotes a board model holding means for holding a board model obtained by simulating a board on which an LSI is mounted. Reference numeral 21 denotes a board model held by the board model holding means 20 and a power supply terminal current waveform held by the power supply terminal current waveform holding means 8. EMI noise analysis means (for example, an electromagnetic field analysis simulator) for analyzing EMI noise.

  When the board on which the LSI is mounted is a printed board, the power supply terminal current waveform acquisition unit 19 uses the LSI model obtained by simulating the LSI 23 mounted on the printed board 22 as shown in FIG. The current waveforms of all the power supply pins of the LSI 23 are acquired as power supply terminal current waveforms.

  In addition, when the substrate on which the LSI is mounted is a SIP (system in package), the power supply terminal current waveform acquisition means 19 is as shown in FIG. 5 when the substrate on which the LSI is mounted is a multilayer wiring substrate constituting the SIP. Then, using the LSI model obtained by modeling the LSIs 26 and 27 mounted on the multilayer wiring board 25, the current waveforms of all the power pads of the LSIs 26 and 27, such as the power pads 28 and 29, are acquired as power source terminal current waveforms. 30 and 31 are bonding wires.

  When the board on which the LSI is mounted is a printed board, the EMI noise analyzing means 21 is obtained from the simulation model of the LSI 23 by the board model obtained by modeling the printed board 22 shown in FIG. The EMI noise is analyzed based on the power supply terminal current waveform.

  Further, the EMI noise analysis means 21 obtains a power supply terminal current waveform and a multilayer wiring board model obtained by simulating the multilayer wiring board 25 shown in FIG. 5 when the board on which the LSI is mounted is a multilayer wiring board constituting the SIP. The means 19 analyzes the EMI noise based on the power supply terminal current waveform acquired from the simulation models of the LSIs 26 and 27.

  In one embodiment of the bypass capacitor arrangement information acquiring apparatus of the present invention, one embodiment of the bypass capacitor arrangement information acquiring method of the present invention is executed. One embodiment of the bypass capacitor arrangement information acquisition method of the present invention includes the following three steps.

  In the first step, the EMI countermeasure frequency determining means 4 has the specific countermeasure frequency held by the specific countermeasure frequency holding means 1, the EMI noise analysis result held by the EMI noise analysis result holding means 2, and the EMI standard holding means 3 This is an EMI countermeasure frequency determination step in which an EMI standard to be held is input, an EMI countermeasure frequency is determined, and the determined EMI countermeasure frequency is held in the EMI countermeasure frequency holding means 5.

  In the second step, the EMI countermeasure power supply terminal determining means 9 inputs the EMI countermeasure frequency held by the EMI countermeasure frequency holding means 5 and the power supply terminal current waveform held by the power supply terminal current waveform holding means 8, and the EMI countermeasure power supply This is an EMI countermeasure power supply terminal determination step in which the terminal is determined and the determined EMI countermeasure power supply terminal number is held in the EMI countermeasure power supply terminal number / optimum bypass capacitor type holding means 10.

  In the third step, the optimum bypass capacitor determining means 15 inputs the EMI countermeasure frequency held by the EMI countermeasure frequency holding means 5, and the bypass having the lowest impedance at the EMI countermeasure frequency is selected from the bypass capacitors in the bypass capacitor database 14. This is an optimum bypass capacitor determination step for determining a capacitor as an optimum bypass capacitor.

  FIG. 6 is a diagram showing an example of the EMI noise analysis result held by the EMI noise analysis result holding means 2. As shown in FIG. 6, the EMI noise has frequency dependency, and in the example of FIG. 6, it can be seen that the frequency Fx exceeds the VCCI standard which is a kind of EMI standard. This frequency Fx is an EMI countermeasure frequency.

  In the present embodiment, the EMI countermeasure frequency determining means 4 includes the specific countermeasure frequency held by the specific countermeasure frequency holding means 1, the EMI noise analysis result held by the EMI noise analysis result holding means 2, and the EMI standard holding means 3 The EMI standard to be held is input and the EMI countermeasure frequency is determined.

  Specifically, the EMI countermeasure frequency calculation unit 6 compares the EMI noise analysis result input from the EMI noise analysis result holding unit 2 with the EMI standard input from the EMI standard holding unit 3, and the frequency exceeding the EMI standard. Are all calculated. For example, when the plurality of frequencies F1, F2,..., Fn exceed the EMI standard, the plurality of frequencies F1, F2,.

  Then, the EMI countermeasure frequency output section 7 determines the EMI countermeasure frequency calculated by the EMI countermeasure frequency calculation section 6 and the specific countermeasure frequency input from the specific countermeasure frequency holding means 1 as the EMI countermeasure frequency, and these are determined as the EMI countermeasure frequency holding means. The EMI countermeasure frequency holding means 5 holds the EMI countermeasure frequency output from the EMI countermeasure frequency output unit 7.

  FIG. 7 is a diagram showing an example of a power supply terminal current waveform held by the power supply terminal current waveform holding means 8 (an example of a current waveform of a certain power supply terminal). In this embodiment, the EMI countermeasure power supply terminal determining means 9 inputs the EMI countermeasure frequency held by the EMI countermeasure frequency holding means 5 and the current waveform of the power supply terminal of the LSI held by the power supply terminal current waveform holding means 8, and the EMI. An EMI countermeasure power supply terminal is determined for each countermeasure frequency.

  Specifically, the current amplitude frequency distribution calculation unit 11 performs a Fourier transform on the power supply terminal current waveform (information for one cycle during LSI operation) held by the power supply terminal current waveform holding unit 8 as shown in FIG. The frequency distribution of the current amplitude of the current flowing through each power supply terminal is calculated, and the current amplitude extraction unit 12 shows the current amplitude frequency distribution of each power supply terminal calculated by the current amplitude frequency distribution calculation unit 11 as shown in FIG. As described above, for each EMI countermeasure frequency, the current amplitude of the EMI countermeasure frequency component of the current flowing through each power supply terminal is extracted.

  Further, the EMI countermeasure power terminal calculating unit 13 calculates the current component of the EMI countermeasure frequency for each EMI countermeasure frequency from the current amplitude of the EMI countermeasure frequency component of the current flowing through each power terminal extracted by the current amplitude extracting section 12. The power supply terminal through which the current with the largest current amplitude flows is calculated as the EMI countermeasure power supply terminal, and this is output to the EMI countermeasure power supply terminal number / optimum bypass capacitor type holding means 10. In the example of FIG. 9, the power supply terminal with the terminal number Nx is calculated as the EMI countermeasure power supply terminal.

  In the present embodiment, a bypass capacitor is disposed near the EMI countermeasure power supply terminal as an EMI countermeasure place. For example, when the wiring board is a printed board, as shown in FIG. 10, when the power supply pin 32 is an EMI countermeasure power supply terminal, the vicinity of the power supply pin 32 is the place where the bypass capacitor 33 is disposed. When the wiring board is a SIP multilayer wiring board, as shown in FIG. 11, when the power supply pad 34 is an EMI countermeasure power supply terminal, the vicinity of the power supply pad 34 is the place where the bypass capacitor 35 is disposed.

  FIG. 12 is a diagram illustrating an example of frequency characteristics of impedance of the bypass capacitor. The bypass capacitor has not only a capacitance but also a parasitic impedance and a parasitic resistance. By these three factors, the impedance of the bypass capacitor greatly depends on the frequency. For this reason, the bypass capacitor has a frequency region which is effective against EMI noise and a frequency region where almost no effect can be expected.

  Therefore, in the present embodiment, the bypass capacitor database 14 is provided, and the optimum bypass capacitor determination means 15 inputs the EMI countermeasure frequency held by the EMI countermeasure frequency holding means 5, and the bypass capacitor The bypass capacitor having the lowest impedance at the EMI countermeasure frequency is determined from the bypass capacitors in the database 14 as the optimum bypass capacitor.

  Specifically, the impedance calculator 16 calculates the impedance of each bypass capacitor at the EMI countermeasure frequency for each EMI countermeasure frequency from the capacitance, parasitic inductance, and parasitic resistance of the bypass capacitor in the bypass capacitor database 14. calculate.

  Then, the optimum bypass capacitor calculation unit 17 compares the impedance of each bypass capacitor for each EMI countermeasure frequency, calculates the bypass capacitor having the lowest impedance as the optimum bypass capacitor for the EMI countermeasure, and uses this as the EMI countermeasure power supply. Output to terminal number / optimum bypass capacitor type holding means 10.

  According to one embodiment of the bypass capacitor arrangement information acquiring apparatus of the present invention, one embodiment of the bypass capacitor arrangement information acquiring method of the present invention can be executed. That is, the EMI countermeasure frequency determining means 4 can determine the EMI countermeasure frequency, the EMI countermeasure power supply terminal determining means 9 can determine the EMI countermeasure power supply terminal, and the optimum bypass capacitor determining means 15 can determine the EMI countermeasure frequency most. An effective bypass capacitor can be selected.

  Therefore, a bypass capacitor having frequency characteristics effective for EMI countermeasures can be arranged in the vicinity of the EMI countermeasure power supply terminal. Therefore, the optimum arrangement of the bypass capacitors with respect to the substrate on which the integrated circuit is mounted is effectively performed, and the EMI countermeasure period is increased. It can be shortened and the EMI countermeasure cost can be reduced.

  Here, when the apparatus and method for acquiring bypass capacitor arrangement information according to the present invention are arranged, the apparatus and method for acquiring bypass capacitor arrangement information according to the present invention include at least the apparatus and method for acquiring bypass capacitor arrangement information described below.

(Supplementary note 1) A bypass capacitor arrangement information acquisition device for acquiring information for arranging a bypass capacitor, and for determining an EMI countermeasure frequency determining an EMI countermeasure frequency from an analysis result of EMI noise generated by a substrate A bypass capacitor arrangement information acquisition apparatus characterized by comprising means.

(Supplementary note 2) The bypass capacitor arrangement information acquisition device according to supplementary note 1, wherein the EMI countermeasure frequency determining means determines a frequency at which an EMI noise value exceeds an EMI standard as a frequency that requires the EMI countermeasure. .

(Supplementary Note 3) The EMI countermeasure frequency determining means determines the frequency for which the EMI countermeasure is specified in advance and the frequency at which the value of the EMI noise obtained from the EMI noise analysis result exceeds the EMI standard. Is determined as a necessary frequency. 2. The bypass capacitor arrangement information acquisition apparatus according to appendix 1, wherein:

(Additional remark 4) It has EMI countermeasure power supply terminal determination means for determining the power supply terminal which needs EMI countermeasure from the frequency required by the EMI countermeasure frequency determination means and the power supply terminal current waveform of the integrated circuit. The bypass capacitor arrangement information acquisition device according to appendix 1, 2 or 3, characterized by the above.

(Additional remark 5) The said EMI countermeasure power supply terminal determination means calculates the frequency distribution of the current amplitude of the electric current which flows into each power supply terminal of the said integrated circuit from the power supply terminal current waveform of an integrated circuit, and has the frequency of the said EMI countermeasure required For each of the power supply terminals of the integrated circuit, a power supply terminal through which a current having a maximum current amplitude of a current component having a frequency requiring the EMI countermeasure is determined as a power supply terminal requiring the EMI countermeasure. The bypass capacitor arrangement information acquisition device according to Supplementary Note 2.

(Supplementary Note 6) For each frequency that requires the EMI countermeasure, a bypass capacitor that has a minimum impedance at the frequency that requires the EMI countermeasure is determined as an optimum bypass capacitor from among the bypass capacitors in the database. The bypass capacitor arrangement information acquisition device according to any one of appendices 1 to 5, further comprising an optimum bypass capacitor determination unit.

(Supplementary note 7) The bypass capacitor database is obtained by creating a database of bypass capacitors using information on product number, capacitance, parasitic inductance, parasitic resistance, and resonance frequency as information. apparatus.

(Supplementary Note 8) The optimum bypass capacitor determination means calculates the impedance of the bypass capacitor in the bypass capacitor database at the frequency requiring the EMI countermeasure for each frequency requiring the EMI countermeasure. The bypass capacitor arrangement information acquisition apparatus according to appendix 6 or 7, wherein the bypass capacitor having the smallest impedance is determined as the optimum bypass capacitor.

(Supplementary note 9) A bypass capacitor arrangement information acquisition method for acquiring information for arranging a bypass capacitor, wherein the EMI countermeasure frequency determining means determines the frequency at which the EMI countermeasure is required from the analysis result of the EMI noise generated by the board. A method of acquiring bypass capacitor arrangement information, comprising a step of determining an EMI countermeasure frequency.

(Supplementary note 10) The bypass capacitor arrangement information acquiring method according to supplementary note 9, wherein, in the EMI countermeasure frequency determining step, a frequency at which an EMI noise value exceeds an EMI standard is determined as a frequency that requires the EMI countermeasure. .

(Supplementary Note 11) In the EMI countermeasure frequency determining step, the frequency at which the EMI countermeasure is specified in advance and the frequency at which the value of the EMI noise obtained from the EMI noise analysis result exceeds the EMI standard are determined as the EMI countermeasure. Is determined as a necessary frequency. 10. The bypass capacitor arrangement information acquiring method according to appendix 9.

(Additional remark 12) EMI countermeasure power supply terminal determination means determines the power supply terminal which requires EMI countermeasure from the frequency and the power supply terminal current waveform of the integrated circuit which require the EMI countermeasure determined in the EMI countermeasure frequency determination step. The bypass capacitor arrangement information acquisition method according to appendix 9, 10 or 11, characterized by comprising a terminal determination step.

(Supplementary Note 13) In the EMI countermeasure power supply terminal determination step, a frequency distribution of current amplitude of current flowing through each power supply terminal of the integrated circuit is calculated from a power supply terminal current waveform of the integrated circuit, and the frequency that requires the EMI countermeasure For each of the power supply terminals of the integrated circuit, the power supply terminal through which the current having the largest current amplitude of the current component of the frequency requiring the EMI countermeasure is determined as the power supply terminal requiring the EMI countermeasure. The bypass capacitor arrangement information acquisition method according to supplementary note 12, characterized by:

(Supplementary Note 14) The optimum bypass capacitor determining means is a bypass capacitor that minimizes impedance at a frequency that requires the EMI countermeasure for each frequency that requires the EMI countermeasure from among the bypass capacitors in the bypass capacitor database. The method for obtaining bypass capacitor arrangement information according to any one of appendices 9 to 13, further comprising: an optimum bypass capacitor determination step for determining as an optimum bypass capacitor.

(Supplementary Note 15) The optimum bypass capacitor determination means calculates the impedance of the bypass capacitor in the bypass capacitor database at the frequency requiring the EMI countermeasure for each frequency requiring the EMI countermeasure. 15. The bypass capacitor arrangement information acquisition method according to appendix 14, wherein the bypass capacitor having the smallest impedance is determined as the optimum bypass capacitor.

It is a conceptual diagram of one Embodiment of the bypass capacitor arrangement | positioning information acquisition apparatus of this invention. It is a figure which shows the example of the bypass capacitor database with which one Embodiment of the bypass capacitor arrangement | positioning information acquisition apparatus of this invention is provided. FIG. 5 is a conceptual diagram of an example of an apparatus for acquiring a power supply terminal current waveform held by a power supply terminal current waveform holding unit and an EMI noise analysis result held by an EMI analysis result holding unit included in an embodiment of a bypass capacitor arrangement information acquisition apparatus of the present invention. is there. It is a conceptual diagram of a printed circuit board. It is a conceptual diagram of a multilayer wiring board of SIP (system in package). It is a figure which shows the example of the EMI noise analysis result hold | maintained by the EMI noise analysis result holding | maintenance means with which one Embodiment of the bypass capacitor arrangement | positioning information acquisition apparatus of this invention is provided. It is a figure which shows the example of the power supply terminal current waveform which the power supply terminal current waveform holding means with which one Embodiment of the bypass capacitor arrangement | positioning information acquisition apparatus of this invention is equipped hold | maintains. It is a figure which shows the example of the current amplitude frequency distribution which the current amplitude calculation part with which the EMI countermeasure power supply terminal determination means with which one Embodiment of the bypass capacitor arrangement | positioning information acquisition apparatus of this invention is provided is provided. It is a figure which shows the example of the current amplitude of each power supply terminal which the current amplitude extraction part with which the EMI countermeasure power supply terminal determination means with which one Embodiment of the bypass capacitor arrangement | positioning information acquisition apparatus of this invention is provided is equipped. It is a figure for demonstrating the arrangement place of the bypass capacitor which uses one Embodiment of the bypass capacitor arrangement | positioning information acquisition apparatus of this invention. It is a figure for demonstrating the arrangement place of the bypass capacitor which uses one Embodiment of the bypass capacitor arrangement | positioning information acquisition apparatus of this invention. It is a figure which shows the example of the frequency characteristic of the impedance of a bypass capacitor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Specific countermeasure frequency holding means 2 ... EMI noise analysis result holding means 3 ... EMI standard holding means 4 ... EMI countermeasure frequency determining means 5 ... EMI countermeasure frequency holding means 6 ... EMI countermeasure frequency calculating section 7 ... EMI countermeasure frequency output section 8 Power source terminal current waveform holding means 9 EMI countermeasure power terminal determining means 10 EMI countermeasure power terminal number / optimum bypass capacitor type holding means 11 Current amplitude frequency distribution calculating section 12 Current amplitude extracting section 13 EMI countermeasure power terminal calculating Unit 14 ... Bypass capacitor database 15 ... Optimum bypass capacitor determination means 16 ... Impedance calculation section 17 ... Optimum bypass capacitor calculation section 18 ... LSI model holding means 19 ... Power supply terminal current waveform acquisition means 20 ... Board model holding means 21 ... EMI noise Analysis means 22 ... printed circuit board 23 ... LSI
24 ... Power supply pin 25 ... Multilayer wiring board 26, 27 ... LSI
28, 29 ... Power supply pad 30, 31 ... Wire bonding 32 ... Power supply pin 33 ... Bypass capacitor 34 ... Power supply pad 35 ... Bypass capacitor

Claims (5)

A bypass capacitor arrangement information acquisition device that acquires information for arranging a bypass capacitor,
EMI countermeasure frequency determining means for determining a frequency that requires EMI countermeasure by arrangement of a bypass capacitor from an analysis result of EMI noise generated by the substrate;
EMI countermeasure power supply terminal determining means for determining a power supply terminal requiring EMI countermeasure from the frequency required for the EMI countermeasure determined by the EMI countermeasure frequency determining means and the power supply terminal current waveform of the integrated circuit;
A bypass capacitor arrangement information acquisition device comprising: The EMI countermeasure power supply terminal determining means calculates the frequency distribution of the current amplitude of the current flowing through each power supply terminal of the integrated circuit from the power supply terminal current waveform of the integrated circuit, and for each frequency requiring the EMI countermeasure. The power supply terminal through which the current having the largest current amplitude of the current component of the frequency requiring the EMI countermeasure is determined as the power supply terminal requiring the EMI countermeasure among the power supply terminals of the integrated circuit. The bypass capacitor arrangement information acquisition device according to 1. Determining an optimum bypass capacitor for each of the bypass capacitors in the bypass capacitor database that determines the bypass capacitor having the minimum impedance at the frequency requiring the EMI countermeasure as the optimum bypass capacitor. The bypass capacitor arrangement information acquiring apparatus according to claim 1, further comprising: means. A bypass capacitor arrangement information acquisition method for acquiring information for arranging a bypass capacitor,
An EMI countermeasure frequency determining means included in the computer determines from the analysis result of the EMI noise generated by the substrate an EMI countermeasure frequency determining step of determining a frequency that requires an EMI countermeasure by disposing a bypass capacitor;
The EMI countermeasure power supply terminal determining means of the computer determines the power supply terminal that requires EMI countermeasure from the frequency and the power supply terminal current waveform of the integrated circuit that require the EMI countermeasure determined in the EMI countermeasure frequency determining step. Power supply terminal determination step;
A bypass capacitor arrangement information acquisition method comprising: The EMI countermeasure power supply terminal determining step calculates a frequency distribution of current amplitude of a current flowing through each power supply terminal of the integrated circuit from the power supply terminal current waveform of the integrated circuit, and for each frequency requiring the EMI countermeasure. A step of determining a power supply terminal through which a current having a maximum current amplitude of a current component having a frequency requiring the EMI countermeasure among the power supply terminals of the integrated circuit is determined as a power supply terminal requiring the EMI countermeasure. The bypass capacitor arrangement information acquisition method according to claim 4.

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