JP2010226033A - Noise countermeasure capacitor mounting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a capacitor effectively function as a bypass capacitor by choosing and mounting a two-terminal capacitor or a three-terminal capacitor without cutting a line, after determining that a noise countermeasure is required in a noise countermeasure capacitor mounting method. <P>SOLUTION: A capacitor mounting method includes mounting and connecting of a two-terminal capacitor 4 or a three-terminal capacitor 5 to a pair of ground lines 2 and a signal line 13 formed on a circuit board 11. A high impedance section 13a with a higher impedance than that of the three-terminal capacitor 5 is formed in a part of the signal line 13. When the three-terminal capacitor 5 is mounted, while arranging and joining a pair of ground electrodes 5a on the pair of ground lines 2, respectively, the high impedance section 13a is arranged between a pair of signal electrodes 5b on the signal line 13, and these signal electrodes 5b are joined. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a noise countermeasure capacitor mounting method suitable for mounting a two-terminal capacitor or a three-terminal capacitor on a circuit board for noise countermeasures such as EMI countermeasures.

Conventionally, as described in, for example, Patent Document 1, a capacitor such as a two-terminal capacitor is mounted on an electronic circuit component or the like for noise countermeasures.
When noise countermeasures are taken on a circuit board, as shown in FIGS. 6 and 7, the ground lines 2 and signal lines (power supply) which are pattern wirings on the circuit board 1 are used to remove high-frequency noise. A pair of end electrodes 4a of the two-terminal capacitor 4 are joined to the line 3), and the two-terminal capacitor 4 is used as a bypass capacitor.

  As shown in FIG. 7B, the two-terminal capacitor 4 has a large equivalent series inductor (ESL) between the electrodes, so that the impedance in the two-terminal capacitor 4 is increased and affects the removal of high-frequency noise. There is a case.

  On the other hand, as shown in FIG. 8 and FIG. 9A, when it is determined that the two-terminal capacitor 4 cannot sufficiently remove high-frequency noise, the signal line 3 and the ground are compared with those of the two-terminal capacitor 4. A three-terminal capacitor 5 having a small ESL with the line 2 is used as a bypass capacitor for removing high-frequency noise. When the three-terminal capacitor 5 is mounted, a pair of ground electrodes 5 a is disposed on the pair of ground lines 2, and a pair of signal electrodes 5 b is disposed on the signal line 3 and joined.

Since the three-terminal capacitor 5 has a small ESL as shown in FIG. 9B, it is possible to suppress an increase in impedance in the three-terminal capacitor 5 and efficiently remove high-frequency noise.
Thus, when it is desirable to take noise countermeasures with multilayer capacitors in electronic circuit mounting, a more effective effect can be expected if the three-terminal capacitor 5 can be used.

JP 2008-60439 A

The following problems remain in the conventional technology.
Conventionally, when a three-terminal capacitor is mounted, a signal electrode is arranged in series with a signal line (power supply line). However, it is necessary to cut and mount the signal line halfway according to the electrode mounting position. However, with this mounting method, it is necessary to mount a three-terminal capacitor even when it is not possible to determine whether noise countermeasures are necessary, so there is a disadvantage that the cost for mounting the three-terminal capacitor increases.
Further, when the signal line is not cut halfway, the signal line impedance is lower than the impedance of the three-terminal capacitor, so that there is a possibility that a problem that the signal or high-frequency noise does not bypass the three-terminal capacitor may occur.

  The present invention has been made in view of the above-described problems. After determining that noise countermeasures are necessary, the bypass capacitor is selected by mounting a 2-terminal capacitor or a 3-terminal capacitor without cutting a line. An object of the present invention is to provide a noise countermeasure capacitor mounting method capable of effectively functioning as

  The present invention employs the following configuration in order to solve the above problems. That is, the noise countermeasure capacitor mounting method of the present invention is a two-terminal capacitor or a pair of grounds having a pair of end electrodes on a pair of ground lines and a signal line which are pattern wirings formed on a circuit board. A capacitor mounting method for mounting and connecting a three-terminal capacitor having an electrode and a pair of signal electrodes, wherein a high impedance portion having a higher impedance than the three-terminal capacitor is formed in a part of the signal line. When mounting the two-terminal capacitor, one of the pair of end electrodes is arranged on and joined to one of the pair of ground lines, and the other of the pair of end electrodes on the signal line. When the three-terminal capacitor is mounted, a pair of ground electrodes are respectively disposed on the pair of ground lines. Together joined, characterized in that for joining the signal electrodes the high impedance portion disposed between the pair of the signal electrode on the signal line.

  In this noise countermeasure capacitor mounting method, when it is determined that noise removal cannot be sufficiently performed with a two-terminal capacitor, and a three-terminal capacitor is mounted, a pair of ground electrodes are respectively arranged on and bonded to a pair of ground lines. Since the high impedance part is arranged between the pair of signal electrodes on the signal line and these signal electrodes are joined, the signal line can secure a higher impedance than the three-terminal capacitor without cutting, and the signal is reliably 3 It flows to the terminal capacitor side. Therefore, the three-terminal capacitor effectively functions as a bypass capacitor, and noise corresponding to the attenuation band of the three-terminal capacitor can be removed.

In the noise suppression capacitor mounting method of the present invention, the high impedance portion is a meander shape portion.
That is, in this noise countermeasure capacitor mounting method, since the high impedance portion is a meander-shaped portion, it is possible to set a desired impedance by the length and the number of turns of the meander-shaped portion that is folded back and formed in a zigzag shape. .

  The noise countermeasure capacitor mounting method of the present invention is characterized in that the high impedance portion is formed with a narrower line width than other portions of the signal line. That is, in this noise countermeasure capacitor mounting method, the high impedance part is formed with a narrower line width than the other parts of the signal line, so it can be set to a desired impedance according to the line width and length. It is.

  In the noise suppression capacitor mounting method according to the present invention, the high impedance portion is formed by installing a magnetic material on the signal line. That is, in this noise countermeasure capacitor mounting method, since the high impedance portion is formed by installing a magnetic material on the signal line, the magnetic material is arranged in the vicinity of the signal line which is a conductor, so that the current is reduced. Due to the change, the inductor inside the induction becomes large, and the impedance increases regardless of the shape of the signal line.

Furthermore, the noise countermeasure capacitor mounting method of the present invention is characterized in that the magnetic material is attached in advance to the mounting surface of the three-terminal capacitor.
That is, in this noise countermeasure capacitor mounting method, since the magnetic material is attached in advance to the mounting surface of the three-terminal capacitor, it is not necessary to install the magnetic material on the signal line before mounting. Simultaneously with the mounting of the capacitor, the magnetic material can be positioned and placed on the signal line.

The present invention has the following effects.
That is, according to the noise countermeasure capacitor mounting method according to the present invention, when it is determined that noise cannot be sufficiently removed with a two-terminal capacitor and a three-terminal capacitor is mounted, a pair of ground electrodes are respectively provided on a pair of ground lines. Since a high impedance part is arranged between a pair of signal electrodes on the signal line and these signal electrodes are joined to each other, a high impedance of the signal line can be secured without being cut, and a three-terminal capacitor Can effectively function as a bypass capacitor.
Therefore, it is easy to distinguish between cases where a capacitor is not mounted for noise countermeasures, an inexpensive two-terminal capacitor, and a case where a three-terminal capacitor is required. The system maintainability can be improved as a result of noise suppression.

It is a perspective view which shows the state which mounted the 2 terminal capacitor and the state which mounted the 3 terminal capacitor in 1st Embodiment of the noise countermeasure capacitor | condenser mounting method which concerns on this invention. In 1st Embodiment, it is a top view of the principal part which shows the signal line and ground line on a circuit board. In 1st Embodiment, it is a top view of the principal part which shows the state which mounted the 2 terminal capacitor | condenser on the circuit board, and the state which mounted the 3 terminal capacitor | condenser. In 2nd Embodiment of the noise countermeasure capacitor | condenser mounting method which concerns on this invention, it is a top view of the principal part which shows the signal line and ground line on a circuit board. It is explanatory drawing which shows the process of mounting a 3-terminal capacitor on a circuit board in 3rd Embodiment of the noise countermeasure capacitor | condenser mounting method which concerns on this invention. It is explanatory drawing which shows the process of mounting a 2 terminal capacitor | condenser in the prior art example of the noise countermeasure capacitor | condenser mounting method which concerns on this invention. It is the top view and equivalent circuit diagram of the principal part which show the state which mounted the 2 terminal capacitor in the prior art example of the noise countermeasure capacitor | condenser mounting method which concerns on this invention. It is explanatory drawing which shows the process of mounting a 3-terminal capacitor | condenser in the prior art example of the noise countermeasure capacitor | condenser mounting method which concerns on this invention. It is the top view and equivalent circuit diagram of the principal part which show the state which mounted the 3 terminal capacitor in the prior art example of the noise countermeasure capacitor | condenser mounting method which concerns on this invention.

  Hereinafter, a first embodiment of a noise countermeasure capacitor mounting method according to the present invention will be described with reference to FIGS. In each drawing used in the following description, the scale is appropriately changed so that each member can be recognized or easily recognized.

  As shown in FIGS. 1 to 3, the noise countermeasure capacitor mounting method of the present embodiment is a pair of ground lines 2 and one power supply line which are pattern wirings formed on a circuit board 11 on which an IC 6 is mounted. This is a capacitor mounting method in which a two-terminal capacitor 4 having a pair of end electrodes 4a or a three-terminal capacitor 5 having a pair of ground electrodes 5a and a pair of signal electrodes 5b is mounted and connected to the signal line 13. .

  On the circuit board 11, a pair of ground lines 2 having one end connected to the terminal of the IC 6 are patterned in parallel with each other with a copper foil or the like. The signal line 13 to which the terminal of the IC 6 is connected is patterned with a copper foil or the like.

As shown in FIG. 2, the circuit board 11 has a high impedance portion 13 a having a higher impedance than the three-terminal capacitor 5 formed in advance on a part of the signal line 13.
The high impedance portion 13a is a meander-shaped portion having a line width that is narrower than that of the other portion in the middle of the signal line 13 and a plurality of folded portions formed in a zigzag shape.
The 2-terminal capacitor 4 and the 3-terminal capacitor 5 are, for example, multilayer capacitors.

  In this noise countermeasure capacitor mounting method, when it is determined that noise countermeasures are necessary, when mounting the two-terminal capacitor 4 first, as shown in FIGS. One of the pair of end electrodes 4a is arranged and joined to one of the lines 2 and the other of the pair of end electrodes 4a is arranged and joined to the signal line 13. The two-terminal capacitor 4 is connected to the signal line 13 and the ground line 2 near the terminals of the IC 6. The connection to the ground line 2 may be any one of a pair.

  Further, when the two-terminal capacitor 4 does not sufficiently remove noise, when the three-terminal capacitor 5 is mounted, as shown in FIG. 1B and FIG. A pair of ground electrodes 5a are arranged and joined, and a high impedance portion 13a is arranged on the signal line 13 between the pair of signal electrodes 5b to join these signal electrodes 5b. That is, each signal electrode 5b of the three-terminal capacitor 5 and the signal line 13 are mounted in parallel.

  As described above, in the noise countermeasure capacitor mounting method according to the present embodiment, when it is determined that the two-terminal capacitor 4 cannot sufficiently remove noise and the three-terminal capacitor 5 is mounted, a pair of ground electrodes are disposed on the pair of ground lines 2. 5a is arranged and joined, and the high impedance portion 13a is arranged on the signal line 13 between the pair of signal electrodes 5b to join these signal electrodes 5b. A higher impedance than that of the terminal capacitor 5 can be ensured, and the signal flows to the three-terminal capacitor 5 side reliably. That is, since a signal (power supply signal) including noise flows to the terminal side of the IC 6 through the three-terminal capacitor 5, the noise is removed.

Therefore, the three-terminal capacitor 5 effectively functions as a bypass capacitor, and noise corresponding to the attenuation band of the three-terminal capacitor 5 can be removed.
When no noise countermeasure is required and the capacitor is not mounted, the signal line 13 is not cut and is connected to the IC 6, so there is no problem in the operation of the IC 6.

  Moreover, since the high impedance part 13a is a meander-shaped part, it can be set to a desired impedance by the length and the number of turns of the meander-shaped part that is folded back and formed in a zigzag shape. In particular, since the high impedance portion 13a is formed with a narrower line width than the other portions of the signal line 13, it is possible to set the impedance higher even in accordance with the line width.

  Next, a second embodiment and a third embodiment of the noise countermeasure capacitor mounting method according to the present invention will be described below with reference to FIGS. In the following description of each embodiment, the same constituent elements described in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The difference between the second embodiment and the first embodiment is that, in the first embodiment, the high impedance portion 13a is a meander shape portion, whereas in the noise countermeasure capacitor mounting method of the second embodiment, FIG. As shown, the high-impedance portion 23 a has a linear extreme detail formed with a narrower line width than the other portions of the signal line 23. In addition, the high impedance part 23a of 2nd Embodiment is set to the very fine line | wire width narrower than the high impedance part 13a of 1st Embodiment.

  That is, in the noise countermeasure capacitor mounting method according to the second embodiment, the high impedance portion 23a is formed to have a narrower line width than the other portions of the signal line 23. Therefore, a desired impedance can be obtained according to the line width and length. Can be set.

The difference between the third embodiment and the first embodiment is that, in the first embodiment, the high impedance portion 13a is such that the shape of the signal line 13 is partially a meander shape portion, whereas the third embodiment is different from the third embodiment. In the noise countermeasure capacitor mounting method of the embodiment, as shown in FIG. 5, the high impedance portion 33 a is formed by installing a ferrite sheet F, which is a magnetic material, on the signal line 3.
The ferrite sheet F is attached in advance to the mounting surface of the three-terminal capacitor 5 and is installed on the signal line 3 simultaneously when the three-terminal capacitor 5 is mounted.

In the noise countermeasure capacitor mounting method according to the third embodiment, as shown in the following equation (1), the ferrite sheet F, which is a magnetic material, is disposed in the vicinity of the signal line 3, which is a conductor, thereby changing the current. This increases the inductor L inside the induction.
L = N (dΦ / dI) (1)
(Φ = magnetic flux, I = current)

At this time, the electrical resistance by the inductor L is obtained by the following equation (2).
ZL = XL = 2πfL (2)
(ZL = inductor impedance, XL = inductive reactance, f = frequency)
Thus, by attaching the ferrite sheet F to the signal line 3 which is a conductor, the impedance increases electrically, and noise (AC component) superimposed on the DC component of the power source is generated by the inductive reactance XL. The noise can be removed by the filter effect of the three-terminal capacitor 5.

Thus, in the noise countermeasure capacitor mounting method of the third embodiment, since the high impedance portion 33a is formed by installing the ferrite sheet F on the signal line 3, the magnetic material is formed in the vicinity of the signal line 3 which is a conductor. As a result of the arrangement, the inductor inside the induction becomes large due to a change in current, and the impedance increases regardless of the shape of the signal line 3.
Further, since the ferrite sheet F is attached in advance to the mounting surface of the three-terminal capacitor 5, it is not necessary to install a magnetic material on the signal line 3 before mounting, and at the same time when the three-terminal capacitor 5 is mounted. The ferrite sheet F can be positioned and installed on the signal line 3.

  The technical scope of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 1,11 ... Circuit board, 2 ... Ground line, 3, 13 ... Signal line, 4 ... Two terminal capacitor, 4a ... End electrode, 5 ... Three terminal capacitor, 5a ... Ground electrode, 5b ... Signal electrode, 6 ... IC , 13a, 23a, 33a ... high impedance part, F ... ferrite sheet (magnetic material)

Claims (5)

A two-terminal capacitor having a pair of end electrodes on a pair of ground lines and one signal line, which are pattern wirings formed on a circuit board, or a three terminal having a pair of ground electrodes and a pair of signal electrodes A capacitor mounting method for mounting and connecting a capacitor,
A high impedance part having a higher impedance than the three-terminal capacitor is formed in a part of the signal line,
When mounting the two-terminal capacitor, one end of the pair of end electrodes is disposed on and joined to one of the pair of ground lines, and the other end of the pair of end electrodes is disposed on the signal line. And join
When the three-terminal capacitor is mounted, a pair of ground electrodes are arranged and bonded to the pair of ground lines, respectively, and the high impedance portion is arranged between the pair of signal electrodes on the signal line. A noise countermeasure capacitor mounting method characterized by joining these signal electrodes. In the noise countermeasure capacitor mounting method according to claim 1,
The noise countermeasure capacitor mounting method, wherein the high impedance portion is a meander shape portion. In the noise countermeasure capacitor mounting method according to claim 1 or 2,
The noise countermeasure capacitor mounting method, wherein the high impedance portion is formed to have a narrower line width than other portions of the signal line. In the noise countermeasure capacitor mounting method according to any one of claims 1 to 3,
The noise countermeasure capacitor mounting method, wherein the high impedance portion is formed by installing a magnetic material on the signal line. In the noise countermeasure capacitor mounting method according to claim 4,
The noise countermeasure capacitor mounting method, wherein the magnetic material is attached in advance to a mounting surface of the three-terminal capacitor.

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