JP2000091151A - Surface mounting part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface mounting part where the state of placement on a circuit board becomes stable without execution of special adjustment by loading a retaining member with an electric part body, in a surface mounting part consisting of the electronic part body and the retaining member. SOLUTION: This surface mounting part comprises a cylindrical electronic part body 2 where an element 1 having specified electric properties is made; and a retaining member 7 which is equipped with a plurality of electrode parts 4 to serve as the relay parts of the conductive path when mounting this electronic part body 2 on a circuit board 3, an insulating base 5 to support that electrode part 4, and a storage hole 6 capable of accommodating and fixing the electronic part body 2. This is a surface mounting part where each electrode part 4 in this retaining member 7 is made in prismatic shape where the hem of the electrode part 4 exists outside the hem of the base 5 and also the flank 8 of each electrode part 4 is positioned on the same plane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component for fixing on a surface of a circuit board, and more particularly to a so-called surface mount component.

[0002]

2. Description of the Related Art Conventionally, among so-called surface mount components, fixed resistors and the like for high power are relatively larger than those usually called chip components, and are generally cylindrical in shape because of emphasis on manufacturing cost. Many exhibit. Since it is difficult to stably mount such a cylindrical electronic component on a circuit board, for example, a prismatic holding member may be inserted into each of the electrode portions at both ends of the electronic component. However, measures have been taken to stabilize the mounting state, and this also has the advantage that a holding member can be shared for electronic components of a similar shape, especially for electronic components having a common electrode portion shape. .

[0003]

However, in the above electronic component, since the electrode portions formed at both ends also have a cylindrical shape, even if the same prismatic holding member is attached to each electrode portion, The orientation of the side surfaces of both holding members varies, and the mounting state must be adjusted so that the side surfaces of both holding members can be mounted on the lands formed on the circuit board without rattling. There was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and in a surface mount component including an electronic component main body and a holding member, the electronic component main body is loaded on the holding member so as to be mounted on a circuit board. It is an object of the present invention to provide a surface mount component in which a mounting state is stabilized without performing special adjustment.

[0005]

Means for Solving the Problems A surface-mounted component according to the present invention made to solve the above-mentioned problems comprises a cylindrical electronic component body on which an element having predetermined electric characteristics is formed,
When mounting the electronic component main body on a circuit board, the electronic component main body includes a plurality of electrode portions serving as relay portions of the conductive path, an insulating base supporting the electrode portion, and a storage hole capable of storing and fixing the electronic component main body. Each electrode portion of the holding member is formed in a concentric polygonal column shape in which the side edge of the electrode portion exists outside the base side edge, and the side surface of each electrode portion is on the same plane. It is characterized by being located.

Elements formed on the electronic component body of the surface mount component include a resistance element, a capacitance element (capacitor), and an inductive element (inductor). Examples of the resistance element include a form in which a resistance film is spirally attached to the surface of an insulating substrate. By using the resistance film as a conductive film having a low resistivity, an inductive element can be obtained. In the case of forming a capacitor, an element portion having a multilayer structure in which an electrode and a dielectric layer are alternately stacked on a substrate may be formed, and electrode portions drawn from the element portion may be formed at both ends. The electrodes may be formed by pressing a conductive metal plate into a cap shape or by printing and firing a conductive paint. Examples of the material of the capacitor include a polymer material containing barium titanate or strontium. Further, the filter may be configured by combining such element portions. On the surface of such an element portion, it is desirable to form an insulating protective film made of glass or the like, but the insulating protective film does not protrude more laterally than the electrode portion. You have to be careful.

As a base of the holding member, an engineering plastic (hereinafter, abbreviated as engineering plastic) such as ceramic, polyacetal, or polycarbonate may be used. If the base is set to a shape having a uniform cross-sectional shape, there is no problem even if ceramic is used as a material, but if the cross-sectional shape is not constant such as having a constriction in the middle part of the base. It is desirable to employ an engineering plastic that can perform various molding methods such as injection molding. The engineering plastic is not only easy to mold, but also has a heat distortion temperature of 100 ° C. and is excellent in heat resistance. As the electrode portion of the holding member, similarly to the electrode portion of the electronic component, a conductive metal plate may be press-formed into a cap shape,
The conductive paint may be printed and fired. However, since the electrode section of the electronic component body and the electrode section of the holding member need to be individually contacted, the electrode section of the electronic component body and the electrode section of the holding member need to be provided at the same interval. In order to prevent a short circuit between the electrode portions, the interval is set to be longer than the length of both electrode portions, and the surface between the electrode portions provided on each member is covered with an insulator. desirable.

[0008] The storage hole may be large enough to receive the electronic component main body at the base portion, but may be formed between the electronic component main body and the circuit board at the electrode portion. Since it is necessary to relay the conductive path, the size must be such that it can just contact the electrode part of the electronic component body. At this time, even if the contact area is sacrificed, in order to improve the heat dissipation of the electronic component main body, the integrated electronic component main body is formed by making the cross-sectional shape of the storage hole not a circle but a polygon,
A ventilation path can be secured between the holding member and the inner surface. Incidentally, the means for engaging the electrode portion of the holding member with the electrode portion of the electronic component body may use, for example, the elasticity of a conductive metal plate, or, for example, make cuts at both ends of the base to form the base. Means such as utilizing the elasticity of engineering plastics, which is one of the materials, may be employed.

To form each electrode portion of the holding member in a polygonal column shape in which the side edge of the electrode portion is outside the side edge of the base portion, for example, the electrode portion is formed as a concentric polygonal column having a larger thickness than the base portion. And matching the directions of the vertices. That is, the structure may be such that the side surface of the base does not protrude outside the side surface of the electrode portion. The side surfaces of the respective electrode portions are configured so as to adhere without looseness to a pad group formed in a state of being located on the same plane on a circuit board for mounting electronic components. Is required. A polygonal pillar refers to a pillar-shaped object with a cross section of three or more corners.However, if the number of corners is too large, contact and stability with a circuit board deteriorate, so at most, a triangle to a hexagon is used. Is considered reasonable. Note that they need not be regular polygonal prisms, but they need to have the same shape of the paired electrode portions and the side surfaces of the polygonal prisms must be located on the same plane.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a surface mount component according to an embodiment of the present invention. The surface mount component shown in FIG. 1 includes a cylindrical electronic component main body 2 on which a fixed resistance element 1 having a predetermined resistance value is formed, and a holding member 7 capable of housing and fixing the electronic component main body 2. Things.

The electronic component body 2 has a metal film, a carbon film,
The fixed resistance element 1 is formed by a metal glaze or an oxide film. At both ends of the electronic component body 2,
Electrode portions 9 connected to the fixed resistance element 1 are formed. The electrodes 9 are formed in a cylindrical shape with a bottom and made of metal, and are attached so as to cover an end face of the base 10 from a part of a side surface of the base 10 covered with the fixed resistance element 1.

When the electronic component body 2 is mounted on the circuit board 3, the holding member 7 includes a plurality of electrode portions 4 serving as relay portions of conductive paths and an insulating base 5 supporting the electrode portions 4. It is configured. The base 5 is formed by molding a so-called insulating material such as engineering plastic or ceramic so that the cross-sectional shape thereof becomes a square prism having a square cross section. A storage hole 6 is formed, and an electrode portion 4 formed by fitting a conductive metal ring 11 is provided at both ends.

The ring 11, which is the electrode portion 4, has a concentric square column shape in which the side edge of the ring 11 exists outside the side edge of the base portion 5, and the edge portion is fixed to both ends of the base portion 5. For this purpose, a male or female fitting portion 12 is formed.
Moreover, the ring 11 has a constant cross-sectional outer shape,
An engaging portion (not shown) is provided at the center portion so as to be electrically connected to the electrode portion 4 of the electronic component body 2 through a sufficient contact area, and is provided inside the engaging portion. A through-hole 13 is formed in which the electrode part 4 of the electronic component body 2 fits.

Electronic component body 2 in the above surface mount component
For example, in an automatic mounting line for mass production, the mounting member 7 may be integrated via a conductive resin or solder before being mounted on the circuit board 3,
For example, in the case of a test board whose circuit adjustment has not been completed, first, after mounting the holding member 7 on the circuit board 3, a means of experimentally loading electronic component bodies 2 of the same size having different constants is used. You can take it.

[0015]

As described above, the use of the surface mount component according to the present invention makes it possible to securely mount the cylindrical electronic component to the circuit board even when performing the work by automatic mounting. it can. In particular, when the cross-sectional shape of the storage hole is polygonal, the heat dissipation efficiency is enhanced, so that the electronic component main body set to consume relatively large power is heated. It can also be suppressed sufficiently.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a surface mount component according to the present invention.

FIGS. 2A, 2B, and 3C are cross-sectional views illustrating an example of a surface mount component according to the present invention.

FIG. 3 is a perspective view showing an example of a surface mount component according to the present invention.

4 (a), (b), and (c) are an embodiment view and a perspective view showing an example of a conventional surface mount component.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Element 2 Electronic component main body 3 Circuit board 4 Electrode part 5 Base part 6 Storage hole 7 Holding member 8 Side surface

Continued on the front page (72) Inventor Yozo Ohara 3158 Shimo-Okubo, Osawano-cho, Kamishinkawa-gun, Toyama F-term in Hokuriku Electric Industry Co., Ltd. 5E336 AA04 CC32 CC51 CC52 CC53 DD04 DD16 DD22 DD26 DD37 EE01 EE07 EE08 GG03

Claims (3)

[Claims] 1. A cylindrical electronic component main body (2) on which an element (1) having predetermined electric characteristics is formed, and a conductive component when the electronic component main body (2) is mounted on a circuit board (3). It is provided with a plurality of electrode parts (4) serving as a relay part of a road, an insulating base (5) supporting the electrode parts (4), and a storage hole (6) capable of storing and fixing the electronic component body (2). Each electrode portion (4) of the holding member (7) is formed into a polygonal column shape in which the side edge of the electrode portion (4) exists outside the base (5) side edge. A surface mount component formed and having the side surfaces (8) of each of the electrode portions (4) positioned on the same plane. 2. A cylindrical electronic component body (2) on which a fixed resistance element (1) having a predetermined resistance value is formed, and when mounting the electronic component body (2) on a circuit board (3). A plurality of electrode portions (4) serving as relay portions of the conductive path, an insulating base (5) supporting the electrode portions (4), and a housing hole (6) for housing and fixing the electronic component body (2). And a plurality of electrode portions (4) of the holding member (7), wherein a side edge of the electrode portion (4) is outside the side edge of the base portion (5). A surface mount component formed in a columnar shape and having the side surfaces (8) of each electrode portion (4) positioned on the same plane. 3. The surface mount component according to claim 1, wherein a cross-sectional shape of the storage hole is polygonal.