JPH09266361A - Voltage variation accommodating structure of circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain minimization of fluctuations in a power voltage of a whole circuit board and thus attain suppression of even irradiation noise caused by fluctuations in a voltage between a power terminal layer and a grounding terminal layer. SOLUTION: A recess 6 is made in each outer peripheral side of a circuit board 1, a plurality of integrated capacitors 7 arranged linearly is accommodated within each of the recesses 6, and each capacitor array 7 is connected to a power terminal layer and a grounding terminal layer of the circuit board. Thereby, when a variation in a power voltage takes place during operation of electronic parts, the capacitor arrays 7 mounted within the outer peripheral sides of the circuit board 1 act to accommodate the voltage variation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage of a circuit board on which an electronic component such as an IC or an LSI is mounted and which has a power supply terminal layer for supplying power to the electronic component and a ground terminal layer for grounding. It relates to a variable absorption structure.

[0002]

2. Description of the Related Art In a circuit board on which electronic components such as IC and LSI are mounted to form a predetermined electronic circuit, a power supply terminal layer and a ground terminal layer are provided for supplying power to the electronic components and grounding. However, since the power supply voltage fluctuates between the power supply terminal layer and the ground terminal layer during the operation of the electronic component of the electronic circuit, the purpose of absorbing the fluctuation of the power supply voltage between the power supply terminal layer and the ground terminal layer in this type of circuit board. A capacitor for absorbing voltage fluctuations called a bypass capacitor or a decoupling capacitor is mounted, and this capacitor is generally provided at a ratio of one to several electronic components such as ICs.

FIG. 13 is a plan view showing a conventional voltage fluctuation absorbing structure of a circuit board. As shown in this figure, conventionally, one capacitor 103 for absorbing voltage fluctuation is mounted on, for example, four electronic components 102 mounted on a circuit board 101, and this capacitor 103 is not shown in the power source. It is connected to the terminal layer and the ground terminal layer. By doing so, fluctuations in the power supply voltage between the power supply terminal layer and the ground terminal layer, which occur during the operation of the electronic component 102, can be suppressed by the capacitor 103
To suppress the fluctuation of the power supply voltage in the vicinity of the capacitor 103 to be small.

Reference numeral 104 in the figure denotes a connector provided at the end of the circuit board 101.

[0005]

However, the above-mentioned conventional techniques have the following problems. That is, FIG. 14 is a diagram showing the effect of suppressing the fluctuation of the power supply voltage between the power supply terminal layer and the ground terminal layer in the prior art. As can be seen from this figure, in the vicinity of the voltage fluctuation absorbing capacitor 103,
Although it is possible to suppress fluctuations in the power supply voltage as shown in FIG.
The voltage fluctuation absorbing function of the capacitor 103 does not work at the part away from 03, for example, the end part of the board to which the connector 4 is attached, so that a large fluctuation of the power supply voltage occurs as shown in FIG. 14 (b). In addition, there is also a problem that the effect of suppressing radiation noise generated due to voltage fluctuation between the power supply terminal layer and the ground terminal layer cannot be obtained.

[0006]

SUMMARY OF THE INVENTION In order to solve such a problem, the present invention mounts an electronic component and includes a power supply terminal layer for supplying power to the electronic component and a ground terminal layer for grounding. In the circuit board voltage fluctuation absorbing structure provided, capacitors for voltage fluctuation absorption are arranged along each side of the outer peripheral portion of the circuit board, and each capacitor is connected to the power supply terminal layer and the ground terminal layer. Characterize.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a first embodiment of a voltage fluctuation absorbing structure for a circuit board according to the present invention, FIG. 2 is a cross-sectional view of an essential part of FIG. 1, and FIG. 3 shows a voltage fluctuation absorbing capacitor used in FIG. It is a front view.

In the figure, reference numeral 1 denotes a circuit board. The circuit board 1 covers the power supply terminal layer 2 and the ground terminal layer 3 with an insulator 4, and the upper and lower surfaces of the insulator 4 and the power supply terminal layer 2 and the ground terminal. The signal line pattern 5 is provided in the insulator 4 between the layer 3 and the concave portion 6 so as to be recessed in the direction parallel to the plate surface from the four sides of the outer peripheral portion. The power supply terminal layer 2 and the ground terminal layer 3 are partially exposed.

Reference numeral 7 is a chip-shaped capacitor for absorbing voltage fluctuations, which has electrodes 8a and 8b at both ends. As shown in FIG. 3A, a plurality of the capacitors 7 are arranged linearly and fixed integrally with resin or the like, or as shown in FIG.
As shown in (b), it is formed in a rod shape so as to have a constant length, and the capacitors 7 thus constructed are mounted in the recesses 6 provided on each side of the outer peripheral portion of the circuit board 1. ,
The capacitors 7 are provided between the power supply terminal layer 3 and the ground terminal layer 4 by bringing the respective electrodes 8a and 8b into contact with the power supply terminal layer 2 and the ground terminal layer 3.

Therefore, according to this, even if the power supply voltage fluctuates during the operation of an electronic component (not shown), the voltage fluctuation is absorbed by the capacitor 7 mounted on the entire outer peripheral portion of the circuit board 1. The effect that the fluctuation of the power supply voltage of the entire circuit board 1 can be suppressed to a low level is obtained, and the effect of suppressing the radiation noise generated due to the voltage fluctuation between the power supply terminal layer and the ground terminal layer is also obtained.

Further, in this embodiment, the voltage fluctuation can be suppressed to a relatively high frequency range. That is, FIG. 4 is a diagram showing the relationship between the number of capacitors mounted on the outer peripheral portion of the circuit board 1 for absorbing voltage fluctuations and the voltage fluctuations. Here, (a) in the figure shows three single capacitors 7 for absorbing voltage fluctuations, (b) in the figure shows 5 capacitors 7,
(c) shows an example in which seven capacitors 7 are mounted.
Further, FIG. 7D is the same as in each of FIGS.
It shows the observation result when the voltage fluctuation is observed with the upper left corner as the vibration source and the lower right corner as the observation point. As can be seen from this figure (d), if the number of capacitors 7 is increased, it becomes wider accordingly. The voltage fluctuation can be suppressed low in the frequency domain.

Therefore, according to the above-mentioned structure in which the capacitor 7 is mounted on the entire outer peripheral portion of the circuit board 1, the effect that the voltage fluctuation can be suppressed to a relatively high frequency range can be obtained. Further, in the above-described structure, since the capacitors 7 are mounted in the recesses 6 provided on the outer peripheral four sides of the circuit board 1, there is an effect that the mounting area of electronic components such as other ICs is not pressed.

FIG. 5 is a cross-sectional view of an essential part showing a second embodiment of the present invention. In this embodiment, a convex portion 9 is formed on the outer peripheral four sides of the circuit board 1 and the convex portion 9 is formed. While exposing a part of the power supply terminal layer 2 and the ground terminal layer 3 on the upper and lower surfaces,
The capacitor 7 is formed in a U shape and the electrode 8 is formed on the inner surface
a and 8b are provided, the capacitor 7 is mounted on the convex portion 9 and the electrodes 8a and 8b are brought into contact with the power supply terminal layer 2 and the ground terminal layer 3, thereby the capacitor 7 is connected to the power supply terminal layer 3 and the ground terminal layer 4 The structure is provided between them.

Incidentally, the capacitor 7 in this embodiment
Also, as in the first embodiment described above, a plurality of pieces are arranged linearly and fixed integrally with a resin or the like, or formed into a rod shape having a certain length. Mounting the capacitor 7 on the whole is the same as in the first embodiment. According to the second embodiment thus configured, since the capacitor 7 is mounted on the entire outer peripheral portion of the circuit board 1, the fluctuation of the power supply voltage of the entire circuit board 1 is the same as in the first embodiment. Can be suppressed to a low level, and an effect of suppressing radiation noise generated due to voltage fluctuation between the power supply terminal layer and the ground terminal layer can also be obtained.

Also in this embodiment, voltage fluctuation can be suppressed to a relatively high frequency range. Also,
If the upper and lower surfaces of the capacitor 7 are flush with the upper and lower surfaces of the circuit board 1 when the capacitor 7 is mounted on the convex portion 9 of the circuit board 1, in the second embodiment as well, It is also possible to obtain the effect of not pressing the mounting area of other electronic components such as ICs.

FIG. 6 is a plan view showing a third embodiment of the present invention, and FIG. 7 is a cross-sectional view of the principal part of FIG. 6, in which the insulator 4 is provided along the outer peripheral portion of the circuit board 1. The chip-shaped capacitors 7 are embedded in the portions at regular intervals, and the power supply terminal layer 3 and the ground terminal layer 4 are provided on the outer peripheral portion of the circuit board 1. The power supply terminal layer 3 and the ground terminal layer 4 are provided with the capacitors 7 respectively. By connecting the electrodes 8a and 8b provided above and below, the variation of the power supply voltage of the entire circuit board 1 can be suppressed to a low level as in the case of the first embodiment, and it can be comparatively achieved. The effect that the voltage fluctuation can be suppressed to a low level even in the high frequency region is obtained, and the effect of suppressing the radiation noise generated due to the voltage fluctuation between the power supply terminal layer and the ground terminal layer is also obtained.

FIG. 8 is a perspective view showing a fourth embodiment of the present invention, and FIG. 9 is a sectional view showing the main part thereof. In the circuit board 1 in this embodiment, the ground terminal layers 3a and 3b are arranged above and below the power supply terminal layer 2, and these are covered with an insulator 4, and the upper and lower surfaces of the insulator 4 serve as signal layers to serve as signal lines. The structure is such that the pattern 5 is formed, and the through hole 10a electrically connected to the power supply terminal layer 2 and the through hole 10b electrically connected to the ground terminal layers 3a and 3b are provided.

Here, the through holes 10a and 10b form a pair and are provided at regular intervals along the outer periphery of the circuit board 1, and the through holes 10a, 1 are provided.
0b to connect the electrodes 8a, 8b to the capacitor 7
Are mounted on the upper and lower surfaces of the circuit board 1 along the outer periphery thereof at regular intervals. That is, the capacitors 7 are mounted on the upper and lower surfaces of the circuit board 1 along the outer peripheral edge in the same number as the number of pairs of the through holes 10a and 10b.

FIG. 10 is an operation explanatory view when a voltage fluctuation occurs between the power supply terminal layer 2 and the ground terminal layers 3a and 3b in the above-mentioned structure. In FIG. 3, 11 is in the circuit board 1. A fluctuating voltage generated at a point, and 12 is an observation point of the voltage fluctuation. In the present embodiment, the power supply terminal layer 2 is sandwiched between the ground terminal layers 3a and 3b from above and below, and the peripheral portions of the ground terminal layers 3a and 3b are electrically short-circuited by the through holes 10b. As described above, the power supply terminal layer 2 has a structure surrounded by the ground terminal layers 3a and 3b and the through hole 10b.

The power supply terminal layer 2 and the ground terminal layer 3
A capacitor 7 for absorbing voltage fluctuations is provided between a and 3b via through holes 10a and 10b provided at regular intervals along the outer periphery of the circuit board 1, and therefore a low frequency of the fluctuation voltage 8 is provided. The component is attenuated by the capacitor 7 and the high frequency component is attenuated by the wrapping structure of the power supply terminal layer 2, so that the voltage fluctuation is not observed at the observation point 12.

FIG. 11 shows the power supply terminal layer 2 and the ground terminal layer 3
The figure which shows the measurement result of the voltage fluctuation between a and 3b.
(a) is a conventional technique which does not have the above-mentioned wrapping structure of the power supply terminal layer 2, 13 in the figure is a measured voltage, and (b) of the same figure shows the wrapping structure of the power supply terminal layer 2 described above. In the embodiment of the present invention that has, 14 in the figure is a measured voltage.

Comparing the case of the prior art with the case of the present embodiment with reference to FIGS. 11 (a) and 11 (b), as shown in FIG. 11 (a), the power supply terminal layer and the ground are shown in the case of the prior art. is effective at a frequency of about 500 mH _Z relative to the voltage variation of the terminal layers, can not be sufficiently absorbed voltage fluctuations at higher frequencies, the voltage fluctuation of the order power terminal layer and the ground terminal layers caused by radiation noise However, the suppressing effect was not obtained.

On the other hand, in the case of the present embodiment, FIG.
As shown in 1 (b), the power supply terminal layer 2 and the ground terminal layer 3 in a wide frequency range from low frequency to high frequency.
It can be seen that the voltage fluctuation between a and 3b is reduced.
Therefore, according to the fourth embodiment, the power supply terminal layer 2
Capacitors 7 for absorbing voltage fluctuations are arranged at constant intervals along the outer peripheral edge of the circuit board 1 having a structure in which is grounded from above and below by the ground terminal layers 3a and 3b, and each capacitor 7 is connected to the through hole 6a and the power supply terminal layer. Through hole 6 connected to 2
Since it is configured to be connected to the power supply terminal layer 2 and the ground terminal layers 3a and 3b via b, it is possible to reduce the voltage fluctuation between the power supply terminal layer 2 and the ground terminal layers 3a and 3b in the entire circuit board 1. The effect of suppressing the radiation noise generated due to the voltage fluctuation between the power supply terminal layer and the ground terminal layer is also obtained.

Since the ground terminal layers 3a and 3b are electrically short-circuited by the through holes 6a, the power supply terminal layer 2 is connected to the ground terminal layers 3a and 3b and the through holes 10.
Since the structure is surrounded by a and the high frequency component of the voltage fluctuation can be attenuated by this structure, the effect of reducing the voltage fluctuation from the low frequency to the high frequency region is also obtained.

FIG. 12 is a cross-sectional view of an essential part showing a fifth embodiment of the present invention. In the fifth embodiment, the upper and lower surfaces of the circuit board 1 are formed as ground terminal layers 3a and 3b. The grounding terminal layers 3a and 3b are short-circuited by a metal short-circuiting component 15 formed in a U shape. That is, the circuit board 1 in this embodiment has the signal line patterns 5 above and below the power supply terminal layer 2.
And disposing the signal layers having the above, and covering them with the insulator 4, and the upper and lower surfaces of this insulator 4 as the ground terminal layers 3a and 3b,
The power supply terminal layer 2 is provided with a through hole 6b that is electrically connected, and a metal shorting component 15 formed in a U-shape is fitted and mounted on the outer periphery of the circuit board 1 to provide grounding. The terminal layers 3a and 3b are short-circuited, and the capacitor 7 for absorbing the voltage fluctuation is connected to its electrodes 8a and 8b.
circuit board 1 on the upper and lower surfaces so that b is connected to through hole 6b and ground terminal layers 3a and 3b.
It is mounted at regular intervals along the outer circumference of.

A plurality of short-circuit components 12 may be mounted on one side of the circuit board 1, but it is convenient if the length is increased and one component is provided on one side of the circuit board 1. is there. Also in the fifth embodiment thus configured, the same operation and effect as those of the above-described first embodiment can be obtained.

FIG. 15 is a plan view showing a sixth embodiment of the present invention, and FIG. 16 is a cross-sectional view of the principal part of FIG. 15. In this embodiment, the power supply terminal layer 2 and the ground terminal layer 3 are made of an insulating material. Four
The chip-shaped capacitors 7 are embedded at regular intervals along the outer periphery of the circuit board 1 covered with the through holes 10a electrically connected to the power supply terminal layer 2, and the ground terminal layer 3
Conductors 16a connected to the through holes 10a along the outer periphery of the upper surface of the circuit board 1 while the through holes 10b electrically connected to the capacitors 7 are provided so as to correspond to the capacitors 7.
And a conductor 16b connected to each through hole 10b along the outer periphery of the upper surface of the circuit board 1.
By connecting the electrodes 8a and 8b of the capacitors 7 to a and 16b, respectively, the capacitors 7 are connected to the power supply terminal layer 2 and the ground terminal layer 3, respectively.

Even in this case, the fluctuation of the power supply voltage of the entire circuit board 1 can be suppressed to a low level as in the first embodiment, and the voltage fluctuation can be suppressed to a relatively high frequency range. Therefore, the effect of suppressing the radiation noise generated due to the voltage fluctuation between the power supply terminal layer and the ground terminal layer is also obtained.

[0029]

As described above, according to the present invention, capacitors for absorbing voltage fluctuations are arranged along each side of the outer peripheral portion of the circuit board, and each capacitor is connected to the power supply terminal layer and the ground terminal layer. As a configuration, a capacitor for absorbing voltage fluctuation is mounted on the entire outer peripheral portion of the circuit board.

Therefore, according to this, even if the power supply voltage fluctuates during the operation of the electronic component, the voltage fluctuation is absorbed by the capacitors mounted on the entire outer peripheral portion of the circuit board. The effect that the fluctuation of the power supply voltage can be suppressed to a low level is obtained, and the effect of suppressing the radiation noise generated due to the voltage fluctuation between the power supply terminal layer and the ground terminal layer is also obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing a first embodiment of a voltage fluctuation absorbing structure for a circuit board according to the present invention.

FIG. 2 is a sectional view of a main part of FIG.

FIG. 3 is a front view of a capacitor for absorbing voltage fluctuations used in FIG.

FIG. 4 is a diagram showing a relationship between the number of mounted capacitors for absorbing voltage fluctuations and voltage fluctuations.

FIG. 5 is a cross-sectional view of an essential part showing a second embodiment of the present invention.

FIG. 6 is a plan view showing a third embodiment of the present invention.

FIG. 7 is a sectional view of a main part of FIG. 6;

FIG. 8 is a perspective view showing a fourth embodiment of the present invention.

9 is a cross-sectional view of the main parts of FIG.

FIG. 10 is an operation explanatory diagram of the fourth embodiment.

FIG. 11 is a diagram showing an actual measurement result of voltage fluctuation between a power supply terminal layer and a ground terminal layer.

FIG. 12 is a cross-sectional view of essential parts showing a fifth embodiment of the present invention.

FIG. 13 is a plan view showing a conventional technique.

FIG. 14 is a diagram showing the effect of suppressing voltage fluctuations in the prior art.

FIG. 15 is a plan view showing a sixth embodiment of the present invention.

16 is a cross-sectional view of the main parts of FIG.

[Explanation of symbols]

 1 Circuit Board 2 Power Supply Terminal Layers 3, 3a, 3b Ground Terminal Layer 4 Insulator 5 Signal Line Pattern 6 Recess 7 Capacitor 8a, 8b Electrode 9 Convex 10a, 10b Through Hole 15 Shorting Parts

Claims (7)

[Claims] 1. A capacitor for absorbing voltage fluctuations in a voltage fluctuation absorbing structure for a circuit board, comprising a power supply terminal layer for mounting electronic parts and supplying power to the electronic parts, and a ground terminal layer for grounding. Is arranged along each side of the outer peripheral portion of the circuit board, and each capacitor is connected to the power supply terminal layer and the ground terminal layer. 2. The voltage fluctuation absorbing structure for a circuit board according to claim 1, wherein a concave portion is provided on each side of an outer peripheral portion of the circuit board, and a plurality of capacitors arranged in a line and integrated or a rod-shaped capacitor are formed. A voltage fluctuation absorbing structure for a circuit board, which is mounted so as to be housed in each recess, and each capacitor is directly connected to the power supply terminal layer and the ground terminal layer. 3. The voltage fluctuation absorbing structure for a circuit board according to claim 1, wherein a convex portion is provided on each side of the outer peripheral portion of the circuit board, and the capacitor formed in a U-shape of the convex portion is mounted so as to be sandwiched. Then
A voltage fluctuation absorbing structure for a circuit board, wherein each capacitor is directly connected to the power supply terminal layer and the ground terminal layer. 4. The voltage fluctuation absorbing structure for a circuit board according to claim 1, wherein a plurality of capacitors are embedded along each side of an outer peripheral portion of the circuit board, and a power supply terminal layer and a ground are provided on upper and lower surfaces of the circuit board. A voltage fluctuation absorbing structure for a circuit board, wherein a terminal layer is provided, and the capacitors are directly connected to the power supply terminal layer and the ground terminal layer. 5. The voltage fluctuation absorbing structure for a circuit board according to claim 1, wherein the circuit board includes ground terminal layers disposed above and below the power supply terminal layer, and through holes connected to the power supply terminal layer and the upper and lower sides thereof. A plurality of through-holes connected to both ground terminal layers are provided along each side of the outer peripheral portion, a plurality of capacitors are arranged along each side of the outer peripheral portion of the circuit board, and each capacitor is A voltage fluctuation absorbing structure for a circuit board, characterized in that the power supply terminal layer and the ground terminal layer are connected through a through hole. 6. The voltage fluctuation absorbing structure for a circuit board according to claim 1, wherein the circuit board includes a ground terminal layer disposed above and below the power supply terminal layer so as to be exposed to the outside, and connected to the power supply terminal layer. A plurality of through holes are provided along each side of the outer peripheral portion, and a U-shaped shorting component is mounted on each side of the outer peripheral portion of the circuit board so as to be sandwiched by the shorting component. While short-circuiting the ground terminal layer, a plurality of capacitors are arranged along each side of the outer peripheral portion of the circuit board, each capacitor is connected to the power supply terminal layer through the through hole, and the ground terminal layer is A circuit board voltage fluctuation absorbing structure characterized by being directly connected. 7. The circuit board voltage fluctuation absorbing structure according to claim 1, wherein a plurality of capacitors are embedded along each side of an outer peripheral portion of the circuit board having a power supply terminal layer and a ground terminal layer therein. Through holes connected to the power supply terminal layer and the ground terminal layer are provided on the circuit board so as to correspond to the capacitors, and the capacitors are connected to the power supply terminal layer and the ground terminal layer through the through holes. A circuit board voltage fluctuation absorbing structure characterized by: