JP2014027033A - Circuit board and display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for suppressing sound production, without mounting a suppression member of mechanical vibration to a circuit board.SOLUTION: The circuit board includes an insulation substrate on which at least one insulation base material layer is laminated and a wiring layer composed of a conductive material is formed on the surface thereof, a first electronic component which is mounted on the insulation substrate and does not generate vibration by variation of an applied voltage, and a second electronic component which generates vibration by variation of an applied voltage. A through hole is made from one side to the other side of the insulation base material layer, and a through hole array is formed by arranging a plurality of through holes. Electronic component mounting area of the insulation substrate is divided into at least two areas of first area and second area by the through hole array, and the second electronic component is mounted in the second area.

Description

  The present invention relates to a circuit board and a display device using the circuit board, and more particularly to a circuit board on which a vibration component such as a capacitive element or an inductance element is mounted and a display device using the circuit board.

  In recent years, high-definition liquid crystal display panels have been developed in portable information terminals typified by small acoustic devices and mobile phone terminals. For this purpose, a video signal driving circuit for supplying a gradation signal (video signal) to each pixel formed on the liquid crystal display panel and a scanning signal for controlling on / off of a thin film transistor disposed in each pixel are supplied. The circuit scale of the scanning signal driving circuit and the like is large. In addition, portable information terminals such as small acoustic devices and mobile phone terminals are generally used outdoors, and higher brightness is being promoted to improve visibility outdoors, which is brighter than indoors. Backlight devices using a light source with higher brightness than those for indoor use are used.

  On the other hand, an increase in the size of a driving circuit and an increase in luminance of a backlight light source accompanying an increase in definition increase current consumption and increase a load on a power supply circuit of a liquid crystal display device. On the other hand, the power supply circuit generally uses a switching power supply that can reduce power loss and can constitute a highly accurate and highly efficient power supply. When the load of this switching power supply increases, the load applied to the smoothing capacitor used to suppress ripple fluctuations also increases, so there is a concern that the so-called sounding of this capacitor may increase. ing. In particular, there is a problem that the vibration (shrinkage) of the capacitor causes the circuit board to vibrate and the sound generation is increased. Furthermore, when the vibration of the capacitor coincides with the natural frequency of the circuit board, the sound generation is further increased by the resonance phenomenon.

  Examples of such a technique for suppressing sound generated on a circuit board include a multilayer circuit board, an electronic device using the multilayer circuit board, and a multilayer circuit board configuration method described in Patent Document 1. In the technique described in Patent Document 1, a non-conductive portion is formed in a part of a conductive pattern formed on a multilayer wiring board. By forming this non-conductive portion, it is possible to reduce the facing area of the wiring layer, reduce electrostatic force, and electrically suppress noise caused by vibration generated between the multilayer wiring board layers It has become.

JP 2006-324451 A

  However, the technique described in Patent Document 1 is a technique for suppressing sound generation between adjacent wirings, and has a problem that sound generation from components mounted on a circuit board cannot be suppressed. In addition, as described in the background art section of Patent Document 1, the frequency of the variable voltage applied to the capacitor is changed, and the frequency of the generated vibration is made higher than the audible frequency, or resin sealing or tape fastening is performed. Although there are physical deterrence such as fixing the substrate and changing the component mounting position to make it difficult to vibrate or vibrate, any of these deterrence methods has the problem of increasing costs and increasing the number of mounting members. Furthermore, a display device mounted on a portable information terminal is required to be reduced in size and thickness, and a circuit board on which the power supply circuit and the like are mounted is also very important to be reduced in size and thickness. . Therefore, there is a strong demand for a sound generation suppression technique that does not involve mounting a sound generation suppression member on a circuit board.

  The present invention has been made in view of these problems, and an object of the present invention is to provide a technique capable of suppressing sound generation without mounting a mechanical vibration suppressing member on a circuit board. There is.

(1) In order to solve the above problems, the circuit board of the present invention is an insulating substrate in which at least one insulating base layer is laminated and a wiring layer made of a conductive material is formed on the surface of the insulating base layer. And a first electronic component that is mounted on the insulating substrate and does not vibrate due to fluctuations in applied voltage, and a second electronic component that vibrates due to fluctuations in applied voltage,
Having a through-hole penetrating from one surface of the insulating base layer to the other surface;
A through-hole row in which a plurality of the through-holes are arranged is formed,
The through hole row divides the electronic component mounting region of the insulating substrate into at least two regions, a first region and a second region,
The second electronic component is mounted on the second region.

(2) In order to solve the above problem, the display device of the present invention has a plurality of drain lines and a plurality of gate lines intersecting the drain lines, and is surrounded by the drain lines and the gate lines. An image display panel in which the selected area is a pixel area;
The circuit board according to (1) described above, which supplies power to the image display panel.
The circuit board includes a switching power supply circuit,
The second electronic component is at least a smoothing capacitor that constitutes the switching power supply circuit.

  According to the present invention, sound generation can be suppressed without mounting a mechanical vibration suppressing member on the circuit board.

  Other effects of the present invention will become apparent from the description of the entire specification.

It is a top view for demonstrating the whole structure of the circuit board of Embodiment 1 of this invention. It is a top view of the 2nd area | region vicinity in the circuit board of Embodiment 1 of this invention. FIG. 3 is a cross-sectional view taken along line A-A ′ shown in FIG. 2. It is sectional drawing of the conventional circuit board corresponding to FIG. It is a top view of the 2nd area | region vicinity in the other circuit board of Embodiment 1 of this invention. It is a top view for demonstrating schematic structure of the circuit board of Embodiment 2 of this invention. It is sectional drawing for demonstrating schematic structure of the circuit board of Embodiment 3 of this invention. It is a top view for demonstrating schematic structure of the circuit board of Embodiment 4 of this invention. It is sectional drawing in the B-B 'line shown in FIG. It is sectional drawing for demonstrating schematic structure of the liquid crystal display device which is a display apparatus of Embodiment 5 of this invention.

  Embodiments to which the present invention is applied will be described below with reference to the drawings. However, in the following description, the same components are denoted by the same reference numerals, and repeated description is omitted.

<Embodiment 1>
FIG. 1 is a plan view for explaining the overall configuration of the circuit board according to the first embodiment of the present invention. Hereinafter, the overall configuration of the circuit board according to the first embodiment will be described with reference to FIG. However, X, Y, and Z shown in the figure indicate an X axis, a Y axis, and a Z axis, respectively. In the following description, the case where the capacitor C1 constituting the power supply circuit is a vibration source (vibration component) will be described. However, the present invention can also be applied to suppression of sound generation for other vibration components such as a coil (inductor). Furthermore, the present invention can be applied to circuit boards of electronic devices other than the power supply circuit.

  As shown in FIG. 1, the circuit board of Embodiment 1 is an insulating substrate (insulating substrate layer) made of a known hard insulating material such as a glass epoxy material as an insulating substrate INB, and is formed on both surfaces of the insulating substrate INB. A wiring layer (signal line) is formed of a conductive material such as copper. In the circuit board according to the first embodiment, a well-known through via (not shown) that electrically connects the wiring layer formed on the front surface side of the insulating substrate INB and the wiring layer formed on the back surface side is formed. Furthermore, in the circuit board of the first embodiment, a plurality of through holes TH are formed in a rectangular shape so as to surround the periphery of the capacitor C1 serving as the vibration component in the first region P1 that is the substrate region. A second region P2 serving as a mounting region is formed. The through hole TH forming the second region P2 penetrates from the front surface side to the back surface side of the insulating substrate INB. In the first embodiment, the through hole TH functions as a through via functioning as a part of the wiring layer. A conductive film made of a conductive material is not formed on the inner peripheral surface of TH, that is, the inner surface of the through hole TH. With this configuration, the formation of the through hole TH according to the first embodiment is a process after coating the surface of the insulating substrate INB, for example, in addition to the process of forming a through via for another signal line. The through hole TH can be formed also in the process of forming the fixing hole for the circuit board body.

  In addition, other electronic components EC excluding vibration components, connectors (not shown), and the like are mounted on a substrate region (first region) P1 that is an outer region of the second region P2 surrounded by the through hole TH. It has become. At this time, the electrical connection between the electronic component (non-vibrating component) mounted in the first region P1 and the electronic component (vibrating component) formed in the second region P2 is between the adjacent through holes TH. A signal line WR2 is formed in the region, and the signal line WR1 in the first region P1 and the signal line WR3 in the second region P2 are electrically connected via the signal line WR2.

  The circuit board according to the first embodiment may be a so-called single-sided board in which a wiring layer is formed only on one side of the insulating substrate INB. In addition, a through hole having a configuration similar to a so-called through via, in which a conductive film is formed on the inner peripheral surface of the through hole and a conductive film along the substrate surface is formed on the peripheral portion of the through hole, is a first embodiment. The through-hole TH may be used. It is also possible to mount electronic components that are not vibration components in the second region P2.

<Detailed configuration of second area>
Next, FIG. 2 shows a plan view of the vicinity of the second region in the circuit board according to the first embodiment of the present invention. Hereinafter, the second region P2 formed in the circuit board according to the first embodiment will be described with reference to FIG. The detailed structure of will be described. However, in the following description, a case where all the through holes TH forming the through hole row THS are formed at the same interval W will be described. However, even if the through hole row THS is formed by the through holes TH having different intervals, Good. Furthermore, the diameter of each through hole TH is not limited to the same diameter R, and the through hole row THS may be formed of through holes TH having different diameters.

  As shown in FIG. 2, the circuit board according to the first embodiment has a configuration in which a through hole TH is formed at a boundary portion between the first region P1 and the second region P2. For example, the interval between the through holes TH arranged in a rectangular shape is W, the diameter of each through hole TH is R, the wiring widths of the signal lines WR1 and WR3 in the first region P1 and the second region P2 are L1, and the signal lines When the wiring width of WR2 is L2, in the circuit board of Embodiment 1, the wiring width L1 of the signal lines WR1 and WR3 is formed larger than the interval W between the through holes TH. For this purpose, the signal line WR1 in the first region P1 and the signal line WR3 in the second region P2 are connected by a single signal line WR2 formed with a wiring width L2 smaller than the interval W between the through holes TH. In this case, the wiring resistance of the entire wiring that electrically connects the capacitor C1 and the electronic component EC is increased.

  Therefore, in the first region P1, the wiring formed by the single signal line WR1 having the wiring width L1 is branched into the three signal lines WR2 having the wiring width L2, and each signal line WR2 is through-holed one by one. It is arranged in a region between TH and is configured to match one signal line WR1 having a wiring width L1 in the second region P2. With this configuration, it is possible to prevent the wiring resistance of the entire wiring that electrically connects the capacitor C1 in the first region P1 and the electronic component EC in the second region P2 from increasing. At this time, the wiring width L1 of one signal line WR1 and WR3 and the wiring width (3 × L2) of three signal lines WR2 of the wiring width L2 are substantially the same wiring width, or one line. The signal lines WR1 to WR3 are formed so that the wiring width of three signal lines having the wiring width L2 is larger than the wiring width L1. With this configuration, it is possible to suppress the influence accompanying the increase in wiring resistance due to the application of the present invention. However, since the wiring width L2 of the signal line WR2 is limited to the interval W between the through holes TH, wiring can be performed by appropriately selecting the number of signal lines that electrically connect the signal line WR1 and the signal line WR3. It is preferable to prevent an increase in resistance.

  Thus, in the circuit board according to the first embodiment, the signal line WR2 is formed in a region that does not overlap with the through hole TH formed so as to surround the first region P1, and the first signal line WR2 is used to form the first signal line WR2. The capacitor C1 mounted in the region P1 and the electronic component EC in the second region P2 are electrically connected. That is, the signal line connecting the capacitor C1 and the electronic component EC is supplemented by the number of signal lines WR2. As a result, even in the case where the vibration component is mounted in the second region P2, it is possible to obtain an effect that the circuit board can be formed with the same circuit configuration as the conventional one without changing the circuit configuration. it can.

<Detailed explanation of pronunciation suppression>
3 is a cross-sectional view taken along the line AA ′ shown in FIG. 2, and FIG. 4 is a cross-sectional view of a conventional circuit board corresponding to FIG. 3. Hereinafter, based on FIGS. The sound generation suppression operation in the circuit board will be described in detail. However, in the following description, a case where the vibration component mounted in the second region P2 is one capacitor C1 will be described, but a configuration in which two or more capacitors C1 and electronic components are mounted may be used.

  As shown in FIG. 2, the second region P2 is configured to be surrounded by an annular through hole row THS in which a plurality of through holes TH are arranged. That is, in the configuration of the circuit board according to the first embodiment, the second region P2 is formed in the first region P1 by a part of the insulating substrate INB formed (remaining) between two adjacent through holes TH. 2 region P2 is supported. Therefore, the rigidity is lower than that of the conventional circuit board, and in particular, the apparent rigidity of the insulating substrate INB as seen from the capacitor C1, which is a vibration component, is reduced.

  In addition, since a gap due to the formation of the through hole TH is formed between the first region P1 and the second region P2, it is generated in the capacitor C1, which is a vibration component, and propagates to the insulating substrate INB in the second region. Of the (transmitted) vibration, the vibration wave that has reached the formation portion of the through hole TH only reaches the peripheral side surface portion of the through hole TH and is not propagated to the first region P1. On the other hand, of the vibration generated in the capacitor C1 and propagated to the insulating substrate INB in the second region, the region between the adjacent through holes TH, that is, the first region P1 and the second region P2 are connected. The vibration wave that reaches the portion is propagated as it is, and is propagated to the first region P1. As described above, in the circuit board according to the first embodiment, the second region P2 is surrounded by the through-hole row THS. Therefore, as shown by the white arrows in FIGS. The vibration propagating from the region P2 to the first region P1 can be greatly reduced. In this case, among the vibrations indicated by the white arrow S1 in the figure generated by the capacitor C1 and propagated to the second area P2, the vibration propagated to the first area P1 is indicated by the white arrow S2 in the figure. Can be reduced as shown. That is, in the configuration of the circuit board according to the first embodiment, the range in which the vibration generated in the capacitor C1 is propagated without being attenuated can be limited to the second region P2. As a result, it is possible to reduce the area of the insulating substrate INB to which the vibration generated by the capacitor C1 that directly increases the sound generated by the vibration generated by the capacitor C1 can be reduced, and thus the sound generated due to the vibration of the capacitor C1. Can be greatly suppressed.

  In the circuit board according to the first embodiment, it is possible to obtain a special effect that it is possible to prevent the sound generated when the frequency of the capacitor C1 resonates with the natural frequency of the circuit board. Hereinafter, a change in the natural frequency of the insulating substrate INB accompanying the formation of the through-hole row THS will be described in detail with reference to FIGS. 3 and 4.

  As described above, in the circuit board according to the first embodiment shown in FIG. 3, the through-hole row THS arranged in a rectangular shape including the plurality of through-holes TH is formed so as to surround the capacitor C <b> 1 that is the vibration component. It has become. Therefore, the natural frequency f2 of the circuit board viewed from the capacitor C1, that is, the insulating substrate INB shown in FIG. 3, is different from the natural frequency f1 of the conventional insulating substrate INB shown in FIG. 4 in which the through hole row THS is not formed. Number.

  For example, the natural frequency f0 when the spring constant is k and the mass is M is expressed by the following formula 1.

f0 = 1 / (2π) × (k / M) ^1/2 (Formula 1)
Therefore, when the spring constant of the circuit board of the first embodiment is k1 and the mass of the circuit board of the first embodiment is M1, the natural frequency f1 of the circuit board of the first embodiment is expressed by the following formula 2. Similarly, when the spring constant of the conventional circuit board is k2 and the mass of the conventional circuit board is M2, the natural frequency f2 of the conventional circuit board is expressed by the following Equation 3.

f1 = 1 / (2π) × (k1 / M1) ^1/2 (Expression 2)
f2 = 1 / (2π) × (k2 / M2) ^1/2 (Expression 3)
Here, in the case where the capacitor C1 vibrates at the frequency fe in the conventional circuit board and sound is generated due to resonance from the circuit board, as shown in FIG. 4, the frequency fe of the capacitor C1 and the natural frequency of the circuit board. A relationship of fe≈f2 is established with f2. In other words, even if the vibration of the capacitor C1 is relatively small due to the resonance of the circuit board having the natural frequency f2 due to the vibration of the capacitor C1 that vibrates at the frequency fe, the large sound generation associated with the occurrence of the resonance. Will arise from the circuit board.

  On the other hand, in the circuit board of the first embodiment, the region where the vibration of the frequency fe of the capacitor C1 is propagated without being attenuated is in the second region P2. Since the second region P2 is an island-shaped region surrounded by the through-hole row THS and is a region formed in the circuit board, the natural frequency f1 of the circuit board of Embodiment 1 is the conventional circuit board. It becomes smaller than the natural frequency f2. That is, by forming the through-hole row THS composed of a plurality of through-holes TH in the circuit board, the overall rigidity of the insulating substrate INB viewed from the capacitor C1, which is a vibration component, can be reduced. k1 can be reduced. As a result, since the natural frequency f1 of the circuit board viewed from the capacitor C1 can be reduced, resonance of the circuit board can be suppressed.

  Hereinafter, resonance in the circuit board of Embodiment 1 will be described in detail. Since the diameter R of each through hole TH formed so as to surround the capacitor C1 is very small, the total area of all the through holes TH is much larger than the area of the insulating substrate INB. In addition, the capacitor C1 and the electronic component EC are mounted on the surface (front side and back side) of the insulating substrate INB. Accordingly, the difference (M2−M1) between the mass M1 of the circuit board of Embodiment 1 and the mass M2 of the conventional circuit board due to the formation of the through-hole row THS is very small, and can be regarded as M1≈M2. . On the other hand, since the capacitor C1 is mounted in the second region P2 surrounded by the through-hole row THS, the apparent spring constant k1 of the insulating substrate INB as viewed from the capacitor C1, that is, the entire circuit board is reduced, and k1 <k2. It becomes.

  Therefore, the natural frequency f1 of the circuit board of the first embodiment calculated from Equation 2 is a natural frequency smaller than the natural frequency f2 of the conventional circuit board. In other words, the natural frequency f0 of the circuit board viewed from the capacitor C1, which is a vibration component, can be made to be a natural frequency f1 that is much smaller than the conventional natural frequency f2 by forming the through-hole row THS. Therefore, in the circuit board according to the first embodiment, the diameter and interval of the through holes TH, the size of the second region P2 surrounded by the through holes TH, and the like are calculated in advance through experiments and the like, and are smaller than the human audible range. The natural frequency f1 can be set. As a result, it is possible to prevent the circuit board (insulating board INB) from resonating with the vibration of the capacitor C1. Furthermore, even when resonance occurs in the circuit board due to the vibration of the capacitor C1, the natural frequency of the circuit board is formed to be smaller than the human audible range, so that the sound produced by the resonance is human audible. It can be out of range, and human perception can be prevented. As described above, in the circuit board according to the first embodiment, the second region P2 having a vibration characteristic different from that of the first region P1 is formed in the first region P1 of the insulating substrate INB. Since the capacitor C1 which is a vibration component is mounted in the region P2, the above-described effects can be obtained.

  As described above, in the circuit board according to the first embodiment, the insulating substrate INB in which the wiring layer made of a conductive material is formed on the surface of the insulating base layer, and mounted on the insulating substrate INB, and vibrates due to fluctuations in the applied voltage. In this configuration, the electronic component EC that does not generate the noise and the capacitor C1 that is an electronic component that generates vibration due to fluctuations in the applied voltage are provided. At this time, a through hole row THS in which a plurality of through holes TH penetrating from one surface to the other surface of the insulating base layer INB, that is, the insulating substrate INB is formed, and the through hole row THS forms an electron on the insulating substrate. The component mounting area is divided into at least two areas, a first area P1 and a second area P2. Here, the capacitor C1, which is an electronic component that generates vibration due to fluctuations in the applied voltage, is mounted in the second region P2. As a result, the region where the vibration of the capacitor C1, which is a vibration component, is directly propagated to the insulating substrate INB can be suppressed within the second region P2, and the vibration propagated to the first region P1 is greatly reduced. Therefore, the sound generation caused by the vibration of the capacitor C1 can be greatly reduced. Furthermore, since the spring constant k1 of the insulating substrate INB viewed from the capacitor C1 that is a vibration component can be reduced, the natural frequency of the insulating substrate INB viewed from the capacitor C1 that is a vibration component can be significantly reduced. It becomes possible. As a result, it is possible to prevent the circuit board from resonating due to the vibration of the capacitor C1, and it is also possible to obtain the effect that the sound generation accompanying the resonance of the circuit board can be prevented.

  In addition, in the circuit board of Embodiment 1, although it was set as the structure which forms previously the through-hole row | line | column THS arrange | positioned cyclically | annularly at the insulated substrate INB, it is not limited to this. For example, the size and material of the insulating substrate INB, the wiring pattern formed on the insulating substrate, the type and mounting position of the electronic component to be mounted, and the magnitude of voltage fluctuation applied to the vibration component (large load fluctuation) Depending on the situation, the sound generation phenomenon of the circuit board may or may not occur. Therefore, a region for forming the through-hole row THS is provided in advance, and a capacitor or the like serving as a vibration component is mounted in a region that is surrounded when the through-hole row THS is formed. Here, a circuit board on which all the electronic components EC are mounted is created, and a continuity test is performed using a circuit board that does not form the through-hole TH2, and a through-hole array is formed on a mass-produced circuit board only when a sound generation phenomenon occurs. It is good also as a structure which forms THS. With such a configuration, it is possible to obtain a special effect that it is not necessary to redesign the circuit board when a sound generation phenomenon occurs.

  In the circuit board according to the first embodiment, the through holes TH are formed by arranging the through holes TH in a straight line in the X direction, and the through holes TH are arranged in a line in the Y direction. The island-shaped rectangular second region P2 that surrounds the capacitor C1 that is the vibration component is formed in the circuit board by the two through-hole rows THS that are formed, but the shape of the second region P2 is It is not limited to a rectangular shape. For example, an island-shaped second region P2 that surrounds the capacitor C1 that is a vibration component may be formed in the circuit board by a through-hole array in which the through-holes TH are arranged in an annular shape or a curved shape. Further, as shown in FIG. 5 (a), one through hole row THS formed by arranging the through holes TH in a straight line in the X direction and one through hole TH in a straight line in the Y direction. Even though the L-shaped through-hole row THS is formed by one through-hole row THS arranged side by side, the second region P2 is formed so as to include at least one corner of the circuit board. Good. Further, as shown in FIG. 5B, a C-shaped through-hole array THS is formed by a plurality of through-holes TH, and two ends of the C-shaped through-hole array THS are formed on the circuit board. The second region P2 may be formed so as to reach the side portion.

<Embodiment 2>
FIG. 6 is a plan view for explaining a schematic configuration of the circuit board according to the second embodiment of the present invention, and is an enlarged plan view of a portion of the second region P2 corresponding to FIG. However, in the circuit board of the second embodiment, only the configuration of the annular through-hole row THS and the signal line formed in the region between the adjacent through-holes are different, and other configurations are the same as those of the first embodiment. It becomes. Therefore, in the following description, the configuration of the through-hole row THS and the signal line will be described in detail.

  As shown in FIG. 6, in the circuit board according to the second embodiment, the through holes TH1 and TH2 constituting the through hole row THS formed so as to surround the capacitor C1 that is the vibration component are arranged in the extending direction of the through hole row THS. On the other hand, it becomes the structure arrange | positioned alternately. That is, also in the annular through-hole row THS of the second embodiment, as in the first embodiment, a pair (two) of through-holes extending in the Y direction and disposed in the X direction so as to sandwich the capacitor C1. A configuration in which a hole row and a pair of X-direction through-hole rows extending in the X direction and disposed in the Y direction so as to sandwich the capacitor C1 are formed, and a rectangular through-hole row THS is formed to surround the capacitor C1 It has become. At this time, in the through hole row THS of the second embodiment, in each through hole row THS extending in the X direction and the Y direction, the adjacent through holes TH1 and TH2 are alternately inclined in the oblique direction with respect to the extending direction. It becomes the composition arranged.

  Also in the configuration of the through-hole row THS of the second embodiment, the capacitor C1 disposed in the second region P2 surrounded by the through-hole row THS and the electronic component EC in the first region P1 are electrically connected. Therefore, a signal line (signal wiring) is required. For this reason, in the circuit board according to the second embodiment, for example, when the diameter of the through hole TH is R and the interval between the adjacent through holes TH is W, the through holes TH having at least alternately arranged diameters are R. Is formed such that the distance between the two is W.

  In the circuit board according to the second embodiment configured as described above, for example, by virtue of the two through-hole rows of the through-hole row THS including the plurality of through-holes TH1 and the through-hole row THS including the plurality of through-holes TH2, the vibration component The configuration can also be realized by a configuration surrounding a certain capacitor C1. That is, of the two through-hole rows THS, a through-hole row (for example, a first through-hole row) THS disposed on the side closer to the capacitor C1, and a through-hole row (on the far side from the capacitor C1) For example, when forming the second through-hole row THS, the through-hole TH1 constituting the first through-hole row THS and the through-hole TH2 constituting the second through-hole row THS are connected to each through-hole row THS. The two through-hole rows THS are formed so as to be deviated by 1/2 with respect to the interval between the respective through-holes TH1 and TH2 with respect to the extending direction (annular direction), and the through-holes TH1 and TH2 are formed. This is possible by forming the through holes TH1 and TH2 so that the distance between them becomes W. Further, this can be realized by forming the two through-hole rows THS so that the interval between the through-hole TH1 and the through-hole TH2 formed in the vicinity of the through-hole TH1 is W.

  Also in the circuit board of the second embodiment described above, the through-hole row THS is formed so as to surround the capacitor C1 that is a vibration component. Therefore, the insulating substrate viewed from the capacitor C1 that is a vibration component. The spring constant k1 of INB can be reduced, and the same effect as in the first embodiment can be obtained. At this time, for example, the interval between the through hole TH1 and the through hole TH1 that are disposed adjacent to each other, and the distance between the through hole TH2 and the through hole TH2 can also be set to W. In this case, since a larger number of through holes TH1 and TH2 can be formed than in the circuit board of the first embodiment, the spring constant k1 of the insulating substrate INB can be further reduced. A special effect of reducing the frequency can be obtained.

  In the circuit board according to the second embodiment, the through hole TH1 and the through hole TH2 are formed so as to be arranged in a zigzag shape, that is, a W shape (Z shape) with respect to the annular direction. Since TH2 surrounds capacitor C1, which is a vibration component, the same effects as in the first embodiment can be obtained. At this time, in particular, in the circuit board of the second embodiment, as is apparent from FIG. 6, the through holes TH1 and the through holes TH2 are sequentially arranged so as to be arranged in a zigzag shape, that is, a W shape with respect to the annular direction. Is formed. As a result, since the through hole TH2 is formed on the extension of the straight line connecting the capacitor C1 and the two through holes TH1, vibration caused by the capacitor C1 propagates to the insulating substrate INB in the second region P2. Then, after propagating through the region between the through hole TH1 close to the capacitor C1, the vibration wave reaches the through hole TH2, and only the vibration wave diffracted through the through hole TH2 is between the through hole TH2. Since it propagates in the region and propagates to the first region P1, it is possible to obtain a special effect that the vibration wave propagating to the first region P1 can be reduced as compared with the first embodiment.

<Embodiment 3>
FIG. 7 is a cross-sectional view for explaining a schematic configuration of the circuit board according to the third embodiment of the present invention, and an enlarged portion of a second region P2 corresponding to FIG. 3 which is a cross-sectional view of the circuit board according to the first embodiment. FIG. However, in the circuit board of the third embodiment, only the configuration in which the capacitor C2 is arranged on the back surface side (lower side surface in the figure) of the insulating substrate INB is different, and the other configurations are the same as those in the first embodiment. . Therefore, in the following description, the capacitor C2 will be described in detail. In the third embodiment, a case where the configuration of the third embodiment is applied to the configuration of the first embodiment will be described. However, a configuration in which the third embodiment is applied to the second embodiment may be used.

  As shown in FIG. 7, in the circuit board according to the third embodiment, when the capacitors C1 and C2 that are the vibration components are mounted in the second region P2, the capacitor C1 and the capacitor C2 are arranged to face each other via the insulating substrate INB. It becomes the composition which is done. In this configuration, for example, when the circuit is configured such that the same signal is input to the capacitor C1 and the capacitor C2, the capacitors C1 and C2 vibrate in the normal direction of the mounting surface. As a result, for example, when the vibration direction caused by the capacitor C1 is the direction indicated by the arrow Z1 that is the normal direction of the mounting surface of the capacitor C1, the vibration direction caused by the capacitor C2 is the same as the mounting surface of the capacitor C2. The direction is indicated by an arrow Z2 that is a normal direction. That is, the capacitor C1 and the capacitor C2 vibrate in a direction to cancel the vibration caused by each of them, and the vibration of the circuit board main body due to the capacitors C1 and C2, which are vibration parts, is reduced.

  As described above, in the circuit board according to the third embodiment, the vibration directions of the capacitor C1 and the capacitor C2 that are the vibration components are opposite to each other. Therefore, the vibration caused by the capacitor C1 and the vibration caused by the capacitor C2 cancel each other. Vibrate. At this time, only vibration that is not canceled by the two capacitors C1 and C2 propagates from the second region P2 to the first region P1, but the capacitors C1 and C2 are also mounted on the circuit board of the third embodiment. Since the second region P <b> 2 is configured to be surrounded by the through-hole row THS including the through-holes TH arranged in a rectangular shape (annular), the same effect as that of the first embodiment can be obtained.

<Embodiment 4>
FIG. 8 is a plan view for explaining a schematic configuration of a circuit board according to the fourth embodiment of the present invention, and FIG. 9 is a sectional view taken along line BB ′ shown in FIG. 8 is an enlarged plan view of a portion of the second region P2 corresponding to FIG. 2 which is a plan view of the circuit board of the first embodiment, and FIG. 9 is a plan view of FIG. 3 of the circuit board of the first embodiment. It is sectional drawing to which the part of the corresponding 2nd area | region P2 was expanded. However, in the circuit board of the fourth embodiment, only the configurations of the insulating substrate INB, the through hole TH3, and the wiring layer WR3 including the three layers of the insulating bases INB1 to INB3 are different, and the other configurations are the same as those of the first embodiment. It becomes. Therefore, in the following description, the insulating substrate INB, the through hole TH3, and the wiring layer WR3 will be described in detail.

  As shown in FIG. 8, the insulating substrate INB constituting the circuit board of the fourth embodiment is formed of three layers of insulating base materials INB1 to INB3. At this time, in the configuration of the fourth embodiment, among the three layers of the insulating base materials INB1 to INB3, the insulating base material INB2 in which the insulating base surface (front surface and back surface) is not exposed, that is, the two insulating base materials INB1 and INB3. A through hole row THS is formed in the insulating base material INB2 sandwiched between the two. The through-hole TH forming the through-hole row THS is a so-called through-hole (Through Hole Via) in which a metal thin film made of a conductive material is formed on the peripheral side surface (inner peripheral surface).

  With this configuration, in the circuit board of Embodiment 4, the upper surface of the insulating base material INB1, the region between the insulating base material INB1 and the insulating base material INB2, the region between the insulating base material INB2 and the insulating base material INB3, And it becomes possible to form a wiring layer in each of the upper surface (back surface) of insulating base material INB3. In other words, even when the wiring layer WR3 is formed in a plane and overlapping with the through hole TH3, the through hole TH3 is not formed on the upper surface of the insulating substrate INB, that is, the exposed surface of the insulating base material INB1. It has become. As a result, as shown in FIG. 8, the wiring layer WR3 that electrically connects the electronic component EC mounted in the first region P1 and the capacitor C1 mounted in the second region P2 is directly connected, that is, the wiring width. It becomes possible to connect without changing L1.

  Also in the configuration of the fourth embodiment, the capacitor C1, which is a vibration component, is surrounded by the through-hole row THS, so that the same effect as that of the first embodiment can be obtained.

  In the circuit board of the fourth embodiment, the case where the insulating substrate INB is formed of the three layers of the insulating bases INB1 to INB3 has been described. However, the configuration of the insulating substrate INB is not limited thereto. For example, an insulating substrate INB is formed by two layers of insulating bases INB1 and INB2, and a through hole TH3 including a through via is formed only in the insulating base INB2 on the side where the capacitor C1 is not mounted. The structure in which the through-hole row THS is formed may be used. Also in this configuration, since the through-hole 3 is not formed on the surface of the insulating base material INB1 on which the capacitor C1 that is a vibration component is mounted, the above-described effects can be obtained. Furthermore, the structure which forms the insulated substrate INB with the insulating base material of 4 layers or more, and forms the through-hole 3 in the insulating base material for at least 1 layer or more may be sufficient.

<Embodiment 5>
FIG. 10 is a cross-sectional view for explaining a schematic configuration of a liquid crystal display device which is a display device according to a fifth embodiment of the present invention, and in particular, a power source for supplying a drive signal to a light source (not shown) and a liquid crystal display panel. The circuit board of the present invention is applied to the circuit. However, in the fifth embodiment, the case where the circuit board of the first embodiment is applied to the power supply circuit in the display device of the fifth embodiment will be described. However, the circuit board of the second and third embodiments may be applied. . Furthermore, in the fifth embodiment, the circuit board of the present invention is applied to a liquid crystal display device as a display device. However, the display device may be applied to other display devices such as an organic EL display device and circuit boards of other electronic circuit devices. Adaptable.

  As shown in FIG. 10, the liquid crystal display device of Embodiment 5 is obtained by fitting and integrating two frame members including a lower frame LF that also functions as a heat sink of a light source (not shown) and an intermediate frame MF. The backlight unit is formed. Further, in the liquid crystal display device of Embodiment 5, the lower frame LF and the middle frame MF are formed in a substantially quadrangular shape, and are integrated so that the side wall portion of the middle frame MF is fitted into the side wall portion of the lower frame LF. A backlight unit is formed. In the lower frame LF, an optical sheet OS such as a reflection sheet MS, a light guide plate LG, and a diffusion sheet is arranged (stored) in order from the bottom surface side. At this time, in the middle frame MF, one plane portion is opened along the side wall surface, and the other plane portion extends from the side wall portion to a frame-like frame region (frame portion), and the light guide plate LG has a planar shape. It has a configuration having an opening region (opening) serving as a window through which the backlight converted into light passes. At this time, the opening region formed on the other surface of the middle frame MF is configured to be smaller than the outer periphery of the light guide plate LG.

  The side wall portion of the lower frame LF and the side wall portion of the middle frame MF are formed so that the side wall surfaces are perpendicular to the respective plane portions (the other plane portions), and the openings of the lower frame LF and the middle frame MF are formed. Thus, the middle frame MF is fitted to the lower frame LF so that one of the two planar portions faces each other. By fitting the lower frame LF and the middle frame MF in this way, the reflection sheet MS, the light guide plate LG, and the optical sheet OS housed in the lower frame LF are held in the lower frame LF.

  A liquid crystal display panel LCD is arranged on the outer surface of the middle frame MF, that is, on the side irradiated with the backlight. The liquid crystal display panel LCD includes a first substrate SUB1 on which a thin film transistor or the like (not shown) is formed, a second substrate SUB2 arranged to face each other via a liquid crystal layer (not shown), and liquid crystal layers of the first substrate SUB1 and the second substrate SUB2. The polarizing plate POL1 and POL2 are disposed on the non-opposing surfaces, and the driving circuit DR is mounted on the side of the first substrate SUB1 larger than the second substrate SUB2. In particular, in the liquid crystal display device according to the fifth embodiment, the backlight unit is disposed on the first substrate SUB1 side, and the first substrate SUB1 and the frame region of the middle frame MF are fixed by the fixing tape AD.

  In the liquid crystal display device according to the fifth embodiment, the red (R), green (G), and blue (B) color display pixels in the liquid crystal display panel LCD are arranged outside the display region in which the pixels are arranged in a matrix. And an upper frame UF for preventing foreign matters such as dust from entering the inside. The upper frame UF has a frame-shaped area (frame-shaped area) in which one plane portion is opened along the side wall surface and the other plane portion extends from the side wall portion, and a display image in the display area passes therethrough. It has the structure which has the opening area | region used as a window part.

  Furthermore, in the liquid crystal display device according to the fifth embodiment, the power supply circuit board PCB on which the drive circuit DR mounted on the side of the liquid crystal display panel LCD and the power supply circuit for supplying control signals and the like to the drive circuit DR are formed. I have. The power circuit board PCB is disposed on the back side of the liquid crystal display device, that is, on the side opposite to the display surface side, and is mounted on the outer surface of the lower frame LF. At this time, in the fifth embodiment, the power supply circuit board PCB is covered with the board cover CC.

  The power circuit board PCB and the liquid crystal display panel LCD are electrically connected via a flexible wiring board FPC. At this time, one end of the flexible printed circuit board FPC is connected to the connector CN of the power circuit board PCB, and the other end of the flexible printed circuit board FPC is connected to a connection terminal section (not shown) or a light source (not shown) formed on the side of the liquid crystal display panel LCD. It is connected.

  The power supply circuit board PCB of the fifth embodiment includes a switching power supply that can reduce power loss and can constitute a highly accurate and highly efficient power supply, and is a smoothing circuit disposed at the output stage in order to suppress ripple fluctuation. The capacitor for use is configured to be mounted in a second region surrounded by a through-hole row composed of a plurality of through-holes. As a result, even when the load on the power supply circuit increases and the load on the capacitor increases and the vibration of the capacitor itself increases, as shown in the effect of the circuit board of the first embodiment, the capacitor Since only a part of the vibration is propagated through the power supply circuit board PCB, sound generation from the power supply circuit can be significantly suppressed. In addition, since the natural frequency of the power circuit board PCB can be smaller than the human audible range, the possibility of sound generation due to resonance can be greatly reduced. Furthermore, even when resonance occurs, it is possible to produce a sound with a resonance frequency smaller than the human audible range, so that it is possible to prevent the sound produced by the resonance from being perceived by humans.

  In the liquid crystal display device according to the fifth embodiment, sound generation from the circuit board constituting the power supply circuit PCB can be significantly suppressed. Therefore, the liquid crystal display device is large when applied to a display device for medical use used in a relatively quiet environment. An effect can be obtained. In particular, a medical display device is placed in a relatively quiet environment such as an operation room or an examination room such as an X-ray imaging device or an X-ray CT device, and thus is quieter than other display devices. Performance is important. The display device according to the fifth embodiment is suitable for use in such a quiet environment because the sound generation can be significantly suppressed.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment of the invention. However, the invention is not limited to the embodiment of the invention, and various modifications can be made without departing from the scope of the invention. It can be changed.

INB: Insulating substrate, INB1-3: Insulating base material, TH: Through hole, THS ... Through hole row WR1-3 ... Signal line, TH1-3 ... Through hole, EC ... Electronic circuit, C1 …… Capacitor SUB1 …… First board, SUB2 …… Second board, FPC …… Flexible wiring board POL1, 2 …… Polarizing board, PCB …… Power circuit board, LCD …… Liquid crystal display panel UF …… Upper frame, MF: Middle frame, LF: Lower frame, MS: Reflective sheet LG ... Light guide plate, OS ... Optical sheet, LG ... Light guide plate, AD ... Fixed tape DR ... Drive circuit, CC ... Substrate cover

Claims (11)

An insulating substrate in which at least one insulating base layer is laminated and a wiring layer made of a conductive material is formed on the surface of the insulating base layer, and mounted on the insulating substrate, and vibration occurs due to fluctuations in applied voltage A circuit board comprising: a first electronic component that is not present; and a second electronic component that is vibrated by fluctuations in applied voltage,
Having a through-hole penetrating from one surface of the insulating base layer to the other surface;
A through-hole row in which a plurality of the through-holes are arranged is formed,
The through hole row divides the electronic component mounting region of the insulating substrate into at least two regions, a first region and a second region,
A circuit board, wherein the second electronic component is mounted on the second region.   The said through-hole row | line | column consists of the said some through-hole arrange | positioned cyclically | annularly, is arrange | positioned so that the said 2nd electronic component may be surrounded, and the said 2nd area | region is formed. Circuit board as described in.   3. The circuit board according to claim 1, wherein an area of the insulating substrate in an electronic component mounting region is configured such that an area of the first region is larger than an area of the second region. .   The circuit board according to any one of claims 1 to 3, wherein the through-hole row includes the through-holes arranged in a zigzag manner in the extending direction.   The through-hole row is composed of two or more through-hole rows, and at least adjacent through-hole rows are formed by shifting through-holes forming each through-hole row. A circuit board according to any one of the above.   6. The insulating substrate according to claim 1, wherein the insulating substrate includes three or more insulating base layers, and the through hole is formed in an insulating base layer sandwiched between at least a pair of insulating base layers. A circuit board according to any one of the above. A first signal wiring formed in the first region, a second signal wiring formed in the second region, and a third signal wiring formed to intersect the through hole row And
The third signal wiring is branched into two or more signal wirings, the branched signal wiring is arranged so as to intersect the through hole, and the branched signal wiring is integrated into one after intersecting the through hole. The circuit board according to claim 1, wherein the circuit boards are combined.   The circuit board according to claim 7, wherein a wiring width of the third signal wiring is smaller than a wiring width of the first signal wiring and / or the second signal wiring.   The circuit board according to claim 7, wherein the third signal wiring is smaller than an arrangement interval of the through holes. An image display panel having a plurality of drain lines and a plurality of gate lines intersecting the drain lines, wherein a region surrounded by the drain lines and the gate lines is a pixel region;
The circuit board according to any one of claims 1 to 9, wherein power is supplied to the image display panel;
With
The circuit board includes a switching power supply circuit,
2. The display device according to claim 1, wherein the second electronic component is at least a smoothing capacitor constituting the switching power supply circuit. The image display panel comprises a liquid crystal display panel composed of a pair of transparent insulating substrates disposed opposite to each other via a liquid crystal layer, and a backlight unit that is disposed on the back side of the liquid crystal display panel and emits backlight light.
The display device according to claim 10, wherein the power supply circuit includes an electronic circuit that supplies power to a light source of the liquid crystal display panel and the backlight unit.

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