JP2009281459A - Washer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting structure of a printed circuit board etc. having not only short circuit characteristics but also inductive and capacitive characteristics. <P>SOLUTION: With a screw shaft of a male screw inserted to a washer, the washer is arranged between a flat head of the male screw and a fastening target of the male screw. The main material of the washer is a magnetic material. Thus, this can produce the inductive grounding state, and prevent outflow of high-frequency noise or intrusion of high-frequency noise. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a washer having an EMC countermeasure function that is used when a printed circuit board on which electronic components are mounted is grounded to a housing.

In recent years, the number of digital devices has increased, and EMC problems such as unnecessary radiation from digital signals have become prominent. In order to solve this EMC problem, EMC countermeasure parts such as a chip resistor, a chip inductor, a chip capacitor for suppressing noise from an LSI, and a ferrite core for suppressing noise from a cable are used. The printed circuit board on which circuit components such as LSI are mounted also emits noise due to resonance from the power supply layer and the ground layer. By strengthening the connection between the ground layer of the printed circuit board and the metal casing, noise emission is radiated. It is possible to suppress.
JP 59-224908 A

  However, although EMC countermeasure parts such as metal male screws, conductive gaskets, and metal fingers have been conventionally used as items for strengthening the grounding with the casing, these EMC countermeasure parts are short-circuited as MC characteristics. It has only characteristics, not inductive or capacitive characteristics.

  The present invention solves the conventional problems, and provides a grounding item for grounding a printed circuit board to a casing, which has not only short-circuit characteristics but also inductivity and capacitive characteristics. Objective.

  In order to solve the conventional problems, the present invention includes the following first to fourth inventions. 1st invention is a washer arrange | positioned between the plate | board of the said male screw, and the fastening object of the said male screw in the state in which the screw shaft of the male screw was penetrated, Comprising: The main material is a magnetic body. . This makes it possible to create an inductive grounding state.

In the first invention,
An element body in which a plurality of coil conductor layers and magnetic layers forming a part of a coil are alternately stacked;
Electrodes provided on the upper and lower surfaces of the element body,
Have
The magnetic layer has a through hole for interlayer connection,
Each of the coil conductor layers adjacent to each other via the magnetic layer constitutes a spiral coil by being connected through the through hole formed in the magnetic layer,
The adjacent coil conductor layer and the electrode are connected through the through-hole formed in the magnetic layer or by direct contact with each other,
There is a mode. This makes it possible to create an inductive grounding state more effectively.

  Further, the first invention has an aspect in which the magnetic body is a ferrite material. According to this, an inductive grounding state can be made at low cost.

  A second invention is a washer arranged between the male screw plate and a fastening target of the male screw in a state where the screw shaft of the male screw is inserted, and a main material is a dielectric. . This makes it possible to create a capacitive ground state.

In the second invention,
An element body in which a plurality of internal electrode layers and dielectric layers are alternately stacked;
First and second electrodes provided on the upper and lower surfaces of the element body,
First and second peripheral electrodes provided on the peripheral surface of the element body and spaced apart from each other in the circumferential direction;
Have
One of the pair of internal electrode layers adjacent to each other across the dielectric layer is connected to the first peripheral electrode, and the other is connected to the second peripheral electrode.
The first peripheral electrode is connected to the first electrode, and the second peripheral electrode is connected to the second electrode to form a comb-like capacitor;
There is a mode. This makes it possible to create a capacitive ground state more effectively.

  Further, the second invention has an aspect in which the dielectric is barium titanate. According to this, it is possible to obtain a larger capacity characteristic.

  3rd invention is a washer arrange | positioned between the plate | board of the said male screw, and the fastening object of the said male screw in the state by which the screw shaft of the male screw was penetrated, Comprising: A main material is a resistor. . According to this, it becomes possible to prevent the outflow of noise or the noise ingress from the housing over the entire band.

The fourth invention is:
A washer arranged between the male screw plate and the fastening target of the male screw in a state where the screw shaft of the male screw is inserted,
With the body,
Electrodes provided on the upper and lower surfaces of the element body,
Chip-type electronic components stored inside the element body;
Have
The external connection electrode of the chip-type electronic component and the electrode are connected. According to this, it becomes possible to change the grounding state according to the characteristics of the chip-type electronic component.

  In a fourth aspect of the invention, the element body is a reinforced plastic. According to this, it becomes possible to endure the pressure by screwing.

  According to a fourth aspect of the present invention, the chip electronic component is a single component or a composite component of a thin film chip resistor, a multilayer chip inductor, a multilayer chip bead, a multilayer chip capacitor, or a multilayer chip varistor. According to this, it becomes possible to form the ground state of the short characteristic, the resistance characteristic, the inductive characteristic, and the capacitance characteristic independently or in combination.

According to a fourth aspect of the present invention, the element body has a component storage hole that penetrates the upper and lower surfaces.
The chip-type electronic component is stored in the component storage hole in a state where a gap is provided between each of the upper and lower surfaces.
The electrode extends from the upper and lower surfaces to the inner peripheral surface of the storage hole and is connected to the external connection electrode.
There is a mode. According to this, it is possible to prevent the chip-type electronic component from being damaged by preventing the pressure due to screwing from being applied directly to the chip-type electronic component.

  According to the present invention, an inductive grounding state can be created. For this reason, if this washer is used when fastening a printed circuit board or the like to a metal casing or the like, high-frequency noise will flow out of the printed circuit board or into the printed circuit board from the casing. Can be prevented. Further, according to the present invention, it is possible to create an inductive grounding state more effectively. Further, according to the present invention, an inductive grounding state can be made at a low cost.

  Further, according to the present invention, it is possible to create a capacitive ground state. For this reason, if this washer is used when fastening a printed circuit board or the like to a metal casing or the like, low frequency and high frequency noise may flow out from the printed circuit board to the casing, or low from the casing to the printed circuit board. Intrusion of frequency and high frequency noise can be prevented. Further, according to the present invention, it is possible to more effectively create a capacitive ground state. Further, according to the present invention, it is possible to obtain a larger capacity characteristic.

  Further, according to the present invention, it is possible to prevent noise from flowing out or entering from the housing over the entire band.

  Further, according to the present invention, the ground state can be changed according to the characteristics of the chip-type electronic component. Further, according to the present invention, it is possible to withstand the pressure caused by screwing. In addition, according to the present invention, it is possible to form the ground state of the short characteristic, the resistance characteristic, the induction characteristic, and the capacitance characteristic independently or in combination. Further, according to the present invention, it is possible to prevent the pressure due to screwing from being directly applied to the chip-type electronic component, and to prevent the chip-type electronic component from being damaged.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIGS. 1A and 1B are diagrams showing a configuration and an example of use of the washer 101 according to Embodiment 1 of the present invention. FIG. 1A is a perspective view of the washer 101. FIG. 1 (b) is a cross-sectional view in the state of use. In these drawings, the annular washer 101 is made of a magnetic material. The washer 101 is used when the printed circuit board 103 to be fastened is grounded to the metal housing 104 via the metal male screw 102. In the present embodiment, the printed circuit board 103 is arranged in parallel to the wall surface of the housing 104, and the ground pattern 103a of the printed circuit board 103 is not the housing facing surface of the printed circuit board 103. It is provided on the opposite substrate surface.

When mounting the washer 10 in an example of the storage structure of the printed circuit board 103 having the above configuration, first, the washer 101 is
The washer 101 is in contact with the ground pattern 103a,
The through hole 101a of the washer 101 matches the through hole 103b in the portion of the printed circuit board 103 on which the ground pattern 103a is formed.
It arranges in the position which satisfies the condition.

  In addition, the metal male screw 102 is inserted into the through holes 101a and 103b from the washer side so that the plate 102a of the metal male screw 102 is in contact with the washer 101, and the housing 104 positioned below the through hole 103b. The screw shaft 102b of the metal male screw 102 is screwed into the screw hole 104a. Accordingly, the printed circuit board 103 is connected to the housing 104 via the washer 101 and grounded in a state having dielectric properties. Therefore, in the present invention, it is possible to create an inductive grounding state, noise flows out from the printed circuit board 103 through the housing 104, and noise is printed from the outside through the housing 104. It is possible to prevent the circuit board 103 from entering.

  A washer 101 whose main material is a ferrite magnetic material may be used. This makes it possible to provide the printed circuit board 103 with an inductive grounding state at a low cost.

  A washer 101 whose main material is a dielectric may be used. Then, a capacitive grounding state can be created on the printed circuit board 103 via the washer 101. As a result, low-frequency and high-frequency noise flows out from the printed circuit board 103 via the housing 104, and low-frequency and high-frequency noise enters the printed circuit board 103 from the outside via the housing 104. It becomes possible to prevent. In this case, if a dielectric made of a barium titanate material is used as the main material of the washer 101, a larger capacity can be obtained.

  A washer 101 whose main material is a resistor may be used. Then, the noise over the entire band flows out from the printed circuit board 103 through the housing 104 and the noise over the entire band from the outside through the housing 104 is prevented from entering the printed circuit board 103. It becomes possible to do.

  Next, other embodiments will be described. Since the washer arrangement structure in these embodiments is the same as that in the first embodiment, the description thereof will be omitted.

(Embodiment 2)
2 (a) to 2 (c) are diagrams showing the configuration of the washer 200 according to Embodiment 2 of the present invention. FIG. 2 (a) is a cross-sectional view of the washer 200, and FIG. FIG. 2B is a plan view of the coil conductor layer 204, and FIG. 2C is a plan view of the magnetic layer 206. In this embodiment, the washer 200 is configured by providing the electrodes 202 and 203 on the upper and lower surfaces of the element body 201. The element body 201 is configured by alternately laminating a plurality of coil conductor layers 204 and magnetic layers 206. The coil conductor layer 204 includes a conductor 205 that constitutes a part of the spiral coil. The magnetic layer 206 includes a through hole 207 for connecting the conductors 205 and 205 of the coil conductor layer 204 disposed above and below. The through hole 207 is also used to connect the conductor 205 of the coil conductor layer 204 and the electrodes 202 and 203. However, the conductor 205 and the electrodes 202 and 203 may be directly connected to each other to connect them. In the present embodiment, a coil is formed inside a magnetic body provided between the electrode 202 and the electrode 203, thereby making it possible to effectively create an inductive ground state. Note that a magnetic layer 206 mainly composed of a ferrite material may be provided, so that an inductive grounding state can be made at low cost.

(Embodiment 3)
FIGS. 3A to 3D are diagrams showing the configuration of the washer 300 according to Embodiment 3 of the present invention. FIG. 3A is a cross-sectional view of the washer 300, and FIG. FIG. 3B is a plan view of the dielectric layer 305, and FIG. 3D is a plan view of the second internal electrode layer 306. FIG. In this embodiment, the washer 300 has a structure in which the first electrode 302 and the second electrode 303 are provided on the upper and lower surfaces of the annular element body 301. The element body 301 is formed by alternately stacking the first internal electrode layers 304 and the second internal electrode layers 306, and then between the adjacent first internal electrode layers 304 and the second internal electrode layers 306. Each has a shape in which a dielectric layer 305 is sandwiched. The first and second internal electrode layers 304 and 306 have the same size and shape as the dielectric layer 305, and the first and second internal electrode layers 304 and 306 are peripheral surfaces of the dielectric layer 305. Exposed to.

  Each of the first inner electrode layers 304 has a bow-shaped first notch 304 a on the outer peripheral portion thereof. Each of the second inner electrode layers 306 has an arcuate second notch 306a on the outer peripheral portion thereof. The first notch 304a and the second notch 306a are disposed in a state where they are opposed to each other at an angle of approximately 180 degrees. A first peripheral surface electrode 301 a and a second peripheral surface electrode 301 b are provided on the peripheral surface of the element body 301. The first peripheral electrode 301a is in contact with the first electrode 302, so that both are selectively connected. The second peripheral electrode 301a is in contact with the second electrode 303, whereby both are selectively connected. The first external connection electrode 301a is disposed at the formation site of the second notch 306a, and the second external connection electrode 301b is disposed at the formation site of the first notch 304a. Accordingly, each first internal electrode layer 304 is selectively connected to the first peripheral electrode 301a in contact with the first peripheral electrode 301a, and further selectively connected to the first electrode 302 via the first peripheral electrode 301a. Connected to. Similarly, the second internal electrode layer 306 contacts and is selectively connected to the second peripheral electrode 301b, and further selectively to the second electrode 303 via the second peripheral electrode 301b. Connected to.

  With the above configuration, a comb-shaped capacitor is formed inside the element body 3041. As a result, the capacitive grounding state can be more effectively created in the present embodiment. Note that a dielectric layer 305 mainly composed of a barium titanate material may be used. By doing so, it is possible to obtain a larger capacity characteristic.

(Embodiment 4)
4 (a) and 4 (b) are diagrams showing the configuration of the washer 400 according to Embodiment 4 of the present invention. FIG. 4 (a) is a cross-sectional view of the washer 400, and FIG. b) is a perspective view of the element body 401. In the present embodiment, the annular washer 400 has a structure in which electrodes 402 and 403 are provided on the upper and lower surfaces of the element body 401. The element body 401 has a component storage hole 401a. The component storage hole 401 a is formed through the upper and lower surfaces of the element body 401. The chip-type electronic component 405 is stored in the component storage hole 401a. The chip-type electronic component 405 is arranged in the component housing hole 401a with the external connection electrodes at both ends thereof facing the electrodes 402 and 403, and the gap between the electrodes 402 and 403 and the chip-type electronic component 405 is , Filled with a conductive material 404. As a result, the electrodes 402 and 403 and the external connection electrode of the chip-type electronic component 405 are connected. In the present embodiment having the above-described configuration, the grounding state can be changed and adjusted according to the characteristics of the chip-type electronic component 405.

  The chip-type electronic component 405 includes a thin film chip resistor, a multilayer chip inductor, a multilayer chip bead, a multilayer chip capacitor, a multilayer chip varistor, or the like.

  In the washer 400 of this embodiment, the built-in chip-type electronic component 405 is made as a single component or a composite component, and the configuration thereof is changed in various ways, so that the grounding state of the short characteristic, the grounding state of the resistance characteristic, and the grounding of the induction characteristic It is possible to form the ground state of the state and the capacity characteristic individually or in combination. Note that the element body 401 may be composed of reinforced plastic as a main material. If it does so, it will become possible to increase the durability with respect to the pressure resulting from screwing.

(Embodiment 5)
FIG. 5 is a cross-sectional view showing a configuration of a washer 500 according to the fifth embodiment of the present invention. The present embodiment is a modification of the fourth embodiment, in which the structure of the component housing hole 501a in which the chip electronic component 502 is incorporated and the connection structure of the chip electronic component 502 are further improved.

  In the fourth embodiment, the gap formed between the chip-type electronic component 405 and the electrodes 402, 403 at both ends of the component storage hole 401a is filled with the conductive material 404, thereby the chip-type electronic component. 405 and the electrodes 402 and 403 were connected. On the other hand, in this embodiment, the gap formed between the chip-type electronic component 505 and the electrodes 502 and 503 is not completely filled with the conductive material 504, and the conductive material 504 and the electrode A space 506 remains between 502 and 503. Thereby, in this Embodiment, it is prevented that the pressure by screwing applies directly to the chip-type electronic component 505, and the damage of the chip-type electronic component 505 is avoided. In addition, although it is conceivable that the chip-type electronic component 505 and the electrodes 502 and 503 are poorly connected by providing the space 506, in this embodiment, the electrodes 502 and 503 are connected to both ends of the component housing hole 501a. The extended ends 502 a and 503 a are brought into contact with the conductive material 504, so that the electrodes 502 and 503 and the external connection electrode of the chip-type electronic component 505 are reliably in contact with each other. Further, in the present embodiment, the tapered surfaces 501b are formed at both ends of the component housing hole 501a, so that the contact between the extended ends 502a and 503a and the conductive material 504 is further ensured. .

  Note that the element body 501 may be composed of reinforced plastic as a main material. Then, it becomes possible to endure more with the pressure by screwing.

  The washer according to the present invention can be applied as an EMC countermeasure means when a printed circuit board on which an electronic component such as an LSI is mounted is grounded to the casing.

It is the perspective view and sectional drawing which show the structure of the washer in Embodiment 1 of this invention. It is sectional drawing which shows the structure of the washer in Embodiment 2 of this invention, the top view of the coil conductor layer which comprises a washer, and the top view of a magnetic body layer. FIG. 6 is a cross-sectional view showing the configuration of a washer in Embodiment 3 of the present invention, a plan view of a first internal electrode layer that constitutes the washer, a plan view of a dielectric layer, and a plan view of a second internal electrode layer. is there. It is sectional drawing which shows the structure of the washer in Embodiment 3 of this invention, and a perspective view of an element | base_body. It is sectional drawing which shows the structure of the washer in Embodiment 5 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Washer 102 Metal male screw 103 Printed circuit board 104 Case 201, 301, 401, 501 Element body 202, 203, 302, 303, 402, 403, 502, 503 Electrode 204 Coil conductor layer 205 Conductor 206 Magnetic body layer 207 Through Hole 304, 306 Internal electrode layer 305 Dielectric layer 404, 504 Conductor material 405, 505 Chip electronic component

Claims (16)

A washer arranged between the male screw plate and the fastening target of the male screw in a state where the screw shaft of the male screw is inserted,
The main material is magnetic material,
A washer characterized by that. An element body in which a plurality of coil conductor layers and magnetic layers forming a part of a coil are alternately stacked;
Electrodes provided on the upper and lower surfaces of the element body,
Have
The magnetic layer has a through hole for interlayer connection,
Each of the coil conductor layers adjacent to each other via the magnetic layer constitutes a spiral coil by being connected through the through hole formed in the magnetic layer,
The adjacent coil conductor layer and the electrode are connected through the through-hole formed in the magnetic layer or by direct contact with each other,
The washer according to claim 1. The magnetic body is a ferrite material,
The washer according to claim 1 or 2, wherein the washer. The fastening object is a printed circuit board fastened to a metal casing,
The washer is interposed between the ground pattern of the printed circuit board and the male screw.
A washer according to any one of claims 1 to 3. A washer arranged between the male screw plate and the fastening target of the male screw in a state where the screw shaft of the male screw is inserted,
The main material is dielectric,
A washer characterized by that. An element body in which a plurality of internal electrode layers and dielectric layers are alternately stacked;
First and second electrodes provided on the upper and lower surfaces of the element body,
First and second peripheral electrodes provided on the peripheral surface of the element body and spaced apart from each other in the circumferential direction;
Have
One of the pair of internal electrode layers adjacent to each other across the dielectric layer is connected to the first peripheral electrode, and the other is connected to the second peripheral electrode.
The first peripheral electrode is connected to the first electrode, and the second peripheral electrode is connected to the second electrode to form a comb-like capacitor;
The washer according to claim 4. The dielectric is barium titanate;
The washer according to claim 5 or 6, wherein the washer. The fastening object is a printed circuit board fastened to a metal casing,
The washer is interposed between the ground pattern of the printed circuit board and the male screw.
A washer according to any one of claims 5 to 7, characterized in that A washer arranged between the male screw plate and the fastening target of the male screw in a state where the screw shaft of the male screw is inserted,
The main material is a resistor,
A washer characterized by that. The fastening object is a printed circuit board fastened to a metal casing,
The washer is interposed between the ground pattern of the printed circuit board and the male screw.
The washer according to claim 7. A washer arranged between the male screw plate and the fastening target of the male screw in a state where the screw shaft of the male screw is inserted,
With the body,
Electrodes provided on the upper and lower surfaces of the element body,
Chip-type electronic components stored inside the element body;
Have
The external connection electrode of the chip-type electronic component and the electrode are connected.
A washer characterized by that. Providing a conductive connection member for connecting the electrode and the external connection electrode;
The washer according to claim 11. The element body is a reinforced plastic;
The washer according to claim 11 or 12, characterized in that: The chip-type electronic component is a single component or a composite component of a thin film chip resistor, a multilayer chip inductor, a multilayer chip bead, a multilayer chip capacitor, or a multilayer chip varistor.
A washer according to any one of claims 11 to 13, characterized in that The element body has a component storage hole penetrating the upper and lower surfaces,
The chip-type electronic component is stored in the component storage hole in a state where a gap is provided between each of the upper and lower surfaces.
The electrode extends from the upper and lower surfaces to the inner peripheral surface of the storage hole and is connected to the external connection electrode.
The washer according to any one of claims 11 to 14, characterized in that: The fastening object is a printed circuit board fastened to a metal casing,
The washer is interposed between the ground pattern of the printed circuit board and the male screw.
The washer according to any one of claims 11 to 15, wherein the washer.

Images