EP2728593A1

EP2728593A1 - Lead type electronic components

Info

Publication number: EP2728593A1
Application number: EP13190359.3A
Authority: EP
Inventors: Shunwei Pan; Takeo Haga; Hejian Zhang
Original assignee: Wuxi Murata Electronics Co Ltd
Current assignee: Wuxi Murata Electronics Co Ltd
Priority date: 2012-11-01
Filing date: 2013-10-25
Publication date: 2014-05-07
Anticipated expiration: 2033-10-25
Also published as: EP2728593B1; CN103811140A; CN103811140B

Abstract

The invention relates to a lead type electronic component comprising a ceramic component, external electrodes formed on two main surfaces of said ceramic component, and lead terminals connected with said external electrodes, respectively, said ceramic component is supported at the upper and lower surfaces by utilizing said lead terminals, one end of said lead terminal at the mounting side can be bended, the lead terminal located on at least one surface of said ceramic component can be formed in a manner that it does not pass through the center portion of the surface of said ceramic component. In such a lead type electronic component, the lead terminals at the mounting side can be bended to be mounted to the substrate, thereby the surface mounting can be performed while the stability of the height position of the lead type electronic component can be maintained, furthermore, the lead terminals do not pass through the center portion of the surface of the ceramic component, better component can be maintained at the center portion of the ceramic component, even though the suction machine is used for sucking when mounting automatically, the problem, such as dropping, and the like, will not occur.

Description

Technical Field

The invention relates to a lead type electronic component, particularly, relates to a lead type electronic component having four lead terminals.

Background Art

With the miniaturization of products, the use of the surface mounted devices(SMD) increases gradually, and the use of the lead type electronic components is decreasing.
However, with already known chip electronic components of SMD type in the prior art, there exists a problem that the power tolerance is low. Therefore, a technology of lead type component with high power tolerance and low installation height will be discussed herein.
For the prior art of the surface mounting of the lead type components, a known structure has been disclosed in Japanese Patent Publication S 62-10627U .
It has been disclosed in Japanese Unexamined Patent Publication S62-10627U a thermistor, which has two metal leads passing through the thermistor and thereby forming four output leads outputting from the thermistor. However, by using the above structure, the following problems will be produced.
For example, the leads pass through internally the thermistor so that the process is very complicated.
Furthermore, the leads cannot be very thick because they have to passing through internally the thermistor. As shown in Fig. 9 of Japanese Unexamined Patent Publication S62-10672U , the diameter of the lead is only 0.12 mm, thereby the size or weight of the product head may be limited, otherwise the product body cannot be supported by the leads.
Furthermore, a structure has been disclosed in the Japanese Unexamined Patent Publication S49-076231U that the metal leads do not pass through internally the thermistor, however, four terminals are outputted across the surface of the thermistor.
However, the surface mounting has not been recorded in the Japanese Unexamined Patent Publication S49-076231U . On the other hand, with the increasing number of the surface mounting devices, the requirement of automatic mounting may be increased. Under the condition of automatic mounting, the surfaces of the lead type components arranged on the mounting machine can be sucked and moved by a suction machine to the mounting destination.
For example, although four leads are used for outputting from the components disclosed in Japanese Unexamined Patent Publication S49-076231 U , referring to Figs. 12 and 13 in the specification of the application, the leads go across the center of the component surface thereby they protrude from the center of the component surface, the suction of the automatic mounting may be affected by the flatness of the component surface.
That is, under a condition of Japanese Unexamined Patent Publication S49-076231U, the leads are arranged approximately at the center of the lead type component, and the solder may be applied above them, because of the protrusion on the surface of the lead type component, it may not be sucked by a suction machine.

The prior art

Patent Document 1: Japanese Unexamined Patent Publication S62-10627U
Patent Document 2: Japanese Unexamined Patent Publication S49-076231U

Summary of the Invention

The technical problems to be solved in the invention

The leads in Japanese Unexamined Patent Publication S62-10627U pass through the chip internally, thus, the process is complicated, and the leads cannot be thick, furthermore, the size and the weight of the product head may be restricted.
Furthermore, the leads in Japanese Unexamined Patent Publication S49-076231U protrude at the center of the component surface, the automatic mounting may be affected by the flatness of the component surface, furthermore, the leads are arranged approximately at the center of the lead type component, and the solder may be applied above them, because of the protrusion on the surface of the lead type component, it may not be sucked excellently under a condition that a suction machine is used.
The invention can be applied to solve the above problems, the object of the invention is to provide a lead type electronic component for surface mounting, the lead type electronic component can be surface mounted while keeping a stable height position of the ceramic component, and to provide a lead type electronic component, which can be sucked by using a suction machine when mounting automatically, and which is a ceramic component having excellent flatness.

The technical scheme used for solving the technical problems

In order to realize the above object, the first aspect of the invention relates to a lead type electronic component, said lead type electronic component comprises:

a ceramic component;
external electrodes formed on two main surfaces of the ceramic component; and
lead terminals electrically connected with said external electrodes, respectively, said lead type electronic component is characterized by that:
- said ceramic component can be supported at upper and lower surfaces by using said lead terminals, one end of said lead terminal at a mounting side can be bended,
- the lead terminal disposed on at least one surface of said ceramic component can be formed in a manner that it does not pass through the center portion of the surface of the ceramic component.

According to the first aspect of the invention, with such a lead type electronic component, one end of the lead terminal at the mounting side is bended to be mounted on the substrate thereby the surface mount can be performed while the stability of the height position of the lead type electronic component can be maintained, furthermore, the lead terminal disposed on at least one surface of said ceramic component can be formed in a manner that it does not pass through the center portion of the ceramic component surface, therefore the flatness of the center portion of the ceramic component can be maintained excellently, even though it is sucked by a suction machine when mounting automatically, dropping, and the like, will not occur.
Furthermore, in order to realize the above object, the second aspect of the invention relates to a lead type electronic component as the first aspect, wherein,
for said lead terminals, two lead terminals can be outputted from two ends of said ceramic component, respectively, in a manner that they pass over the upper and lower surfaces of said ceramic component, respectively, thereby four terminals can be formed, the lead terminals positioned on two main surfaces of said ceramic component can be formed in a manner that they do not pass through the center portion of said ceramic component surface.
According to the second aspect of the invention, two lead terminals pass over said ceramic component and support the ceramic component with the upper and lower surfaces, therefore the ceramic component can be supported more stably, and a lead type electronic component having excellent flatness when surface mounting can be provided.
In addition, in order to realize the above object, the third aspect of the invention relates to a lead type electronic component as the first or the second aspect, wherein,
said lead terminal can be formed on the surface of said ceramic component to have a shape along the peripheral of the ceramic component.
According to the third aspect of the invention, the flat area of the center portion on the surface of the ceramic component can be made larger, and the dropping under the condition of using a suction machine when automatic mounting can be avoided.
In addition, in order to realize the above object, the fourth aspect of the invention relates to a lead type electronic component as the first aspect, wherein,
for said lead terminal, two lead terminals can be bended, respectively, so that they do not pass through the center portion of the surface of said ceramic component on two main surfaces of said ceramic component, and can be outputted from said ceramic component at the same direction, the upper lead terminal outputted from the upper surface of said ceramic component and the lower lead terminal outputted from the lower surface of said ceramic component can be outputted at different direction with each other.
According to the fourth aspect of the invention, 2 lead terminals can be outputted at the same direction, respectively, thereby the bending height position of the lead terminal can be suppressed easily, and the height position deviation can be smaller. Therefore, the flatness of the substrate when mounting can be further improved.
In addition, in order to realize the above object, the fifth aspect of the invention relates to a lead type electronic component as the first aspect, wherein,
for said lead terminal, two lead terminals among four lead terminals are formed on the upper surface of the ceramic component and can be outputted at one direction in a manner that they do not pass through the center portion of the surface of said ceramic component, the remaining 2 lead terminals are formed on the lower surface of said ceramic component and can be outputted at a direction opposite to the direction at which said 2 lead terminals formed on the upper surface being outputted.
According to the fifth aspect of the invention, among 4 lead terminals, 2 lead terminals can be outputted from the upper surface of the ceramic component at one direction, the remaining 2 lead terminals can be outputted from the lower surface of the ceramic component at a direction opposite to the direction that the above two lead terminals outputted, the respective lead terminals are independent with each other, thus, the center portion of the ceramic component surface can be avoided from being passed through completely by such an arrangement. In addition, the manufacturing process is rather simple, because there is no need to bend one lead terminal on the ceramic component for avoiding the center portion of the surface of the ceramic component. In addition, the respective height positions of two lead terminals outputted at the same direction are the same with each other, thus, the processing of the bending position of the respective lead terminals can be performed easily.
Furthermore, in order to realize the above object, the sixth aspect of the invention relates to a lead type electronic component as the first aspect, wherein,
for said lead terminals, 2 lead terminals among 4 lead terminals are formed on the upper surface of said ceramic component and outputted from the upper surface in a manner that they do not pass through the center portion of the surface of said ceramic component, and the remaining 2 lead terminals can be located on the lower surface of said ceramic component,
Said lead terminals can be bended, respectively, so that when seeing said ceramic component from the top, the end of said lead terminal at the mounting side may be perpendicular to a direction at which said lead terminal is outputted from said ceramic component.
According to the sixth aspect of the invention, when the surface mounting is performed on the substrate, by forming such a structure to increase the mounting area, and it can be soldered reliably on the substrate, thus, the mounting strength can be improved. In a usage that the mounting area has no limitation, the above method is very effective.
In addition, in order to realize the above object, the seventh aspect of the invention relates to a lead type electronic component as the first aspect, wherein,
2 lead terminals are formed on the upper surface side of said ceramic component, each end of each of the two lead terminals can be located on the upper surface of said ceramic component, and can be formed in a manner that they do not pass through the center portion of said ceramic component surface, each of the other terminals of said 2 lead terminals can be outputted from positions opposite to each other with respect to the center of said ceramic component,
the output direction of the lead terminals outputted externally from said ceramic component, respectively, and formed on the lower surface side of said ceramic component is different from the output direction of 2 lead terminals formed on said upper surface side.
According to the seventh aspect of the invention, under a condition that 4 lead terminals or 3 lead terminals are used, if a shape along the peripheral of the ceramic component is formed, then the flat area on the center portion of the ceramic component will be larger, and the following practical effect can be obtained, that is, the problem of dropping can be avoided when the automatic mounting is performed by using a suction machine. Furthermore, because the terminals are outputted from the ceramic component at four directions, by comparing with the condition of outputted at two directions, the mounting stability can be further improved. Of course, the same result as that in the first aspect can be realized in the seventh aspect.
Furthermore, in order to realize the above object, the eighth aspect of the invention relates to a lead type electronic component as the first or the fifth aspect, wherein,
said lead terminals and the surface of said ceramic component having external electrodes formed thereon can be covered by a heat shrinkable tube.
According to the eighth aspect of the invention, by covering the ceramic component using a heat shrinkable tube, the height difference produced on the ceramic component surface can be absorbed, and the flatness of the surface of the ceramic component can be further improved.
In addition, in order to realize the above object, the ninth aspect of the invention relates to a lead type electronic component as the first or the fifth aspect, wherein,
said lead terminals and the surface of said ceramic component having external electrodes formed thereon can be covered by a cover layer, said lead terminals and the external electrodes formed on the surface of said ceramic component can be connected by solder and a welding portion can be formed, said welding portion can be formed at a position separated from the portion where said lead terminal outputted from said ceramic component.
The lead terminals and the external electrodes formed on the surface of the ceramic component can be connected by solder, under a condition that the lead type electronic components are mounted by re-flowing, and under a condition that the cover layer, such as heat shrinkable tube, resin layer, and the like, is formed, the thermal history can be applied, for the welding position, the solder below the heat shrinkable tube or resin layer may be melted, and the solder may flow out from the portion where the lead terminal outputted from the cover layer. According to the ninth aspect of the invention, by separating the weld position from the portion where the lead terminal outputted from the ceramic component as far as possible, thereby even though the solder is melted because of the thermal history, it can still be retained inside the cover layer, and it can be prevented from flowing out from the output portion of the lead terminal.
In addition, in order to realize the above object, the tenth aspect of the invention relates to a lead type electronic component as the first or the fifth aspect, wherein,
said lead terminals and the surface of said ceramic component having external electrodes formed thereon can be covered by a heat shrinkable tube or resin, said lead terminals and the external electrodes formed on the surface of said ceramic component can be connected by solder and a welding portion can be formed, and a bending portion can be formed between said welding portion and a portion of the lead terminal where said lead terminal outputted from said ceramic component.
The lead terminals and the external electrodes formed on the surface of the ceramic component can be connected by solder, under a condition that the lead type electronic components are mounted by re-flowing, and under a condition that the cover layer, such as heat shrinkable tube, resin layer, and the like, is formed, the thermal history can be applied, for the weld position, the solder below the heat shrinkable tube or resin layer may be melted, and the solder may flow out from the portion where the lead terminals outputted from the cover layer. According to the tenth aspect of the invention, a bending portion can be formed between said welding portion and a portion where said lead terminals outputted from said ceramic component, thus, the solder can be prevented from flowing out from the output portion of the lead terminals.
In addition, in order to realize the above object, the eleventh aspect of the invention relates to a lead type electronic component as the first or fifth aspect, wherein,
one end of said lead terminal at the mounting side can be bended toward the center portion of the ceramic component.
According to the eleventh aspect of the invention, one end of said lead terminal at the mounting side can be bended toward the center portion of the ceramic component, thus, the mounting area can be decreased under a condition of surface mounting.

Description of Figures

Fig. 1A illustrates a view of a lead type electronic component related to Embodiment 1 of the invention, Fig. 1B illustrates a view of an alternative example of a lead type electronic component related to Embodiment 1 of the invention.
Fig. 2 illustrates a view of a lead type electronic component related to Embodiment 2 of the invention.
Fig. 3 illustrates a view of a lead type electronic component related to Embodiment 3 of the invention, Fig. 3A illustrates an alternative example of Fig. 1A, Fig. 3B illustrates an alternative example of Fig. 1B.
Fig. 4 illustrates a view of a lead type electronic component related to Embodiment 4 of the invention, Fig. 4A and Fig. 4B are included in Fig. 4.
Fig. 5 illustrates a view of a lead type electronic component related to Embodiment 5 of the invention.
Fig. 6 illustrates a view of a lead type electronic component related to Embodiment 6 of the invention, Fig. 6A illustrates an alternative example of Fig. 1A, Fig. 6B illustrates an alternative example of Fig. 5.
Fig. 7 illustrates a view of a lead type electronic component related to Embodiment 7 of the invention, Fig. 7A illustrates an alternative example of Fig. 5, Fig. 7B illustrates an alternative example of Fig. 7A.
Fig. 8 illustrates a view of a lead type electronic component related to Embodiment 8 of the invention, Fig. 8A illustrates an alternative example of Fig. 1A, Fig. 8B illustrates an alternative example of Fig. 5.
Fig. 9 illustrates a view of a lead type electronic component related to Embodiment 9 of the invention, Fig. 9A illustrates an alternative example of Fig. 8A, Fig. 9B illustrates an alternative example of Fig. 5.
Fig. 10 illustrates a view of a lead type electronic component related to Embodiment 10 of the invention, Fig. 10 illustrates an alternative example of Fig. 5.
Fig. 11 is a top view of the mounting state of the components in the prior art.
Fig. 12 is a top view of the components in the prior art.
Fig. 13 is a cross sectional view of the components in Fig. 12 taken along line A-A'.

Detailed Description of the Invention

Because the precision of the drawings is low, it seems that the terminals float above the ceramic component, the resin float above the ceramic component and the lead terminals, and there are interspaces among them. However, it will be understood by those skilled with the ordinary technology of the art, that actually no interspaces exist among them.

Embodiment 1

[Structure]

The lead type electronic component in the application of the invention will be described by using Fig. 1A and Fig. 1B as follows.
The lead type electronic component comprises a ceramic component 1, external electrodes 2a, 2b formed on two main surfaces of the ceramic component 1, and the lead terminals 3a, 3b connected electrically with said external electrodes 2a, 2b, respectively, and outputted externally. Particularly, the ceramic component 1 of the invention can be supported at upper and lower surfaces by the lead terminals 3a, 3b, and one end of the lead terminals 3a, 3b at the mounting side are bended. The lead terminal 3 a is located at the upper surface of the ceramic component 1, and the lead terminal 3b is located at the lower surface of the ceramic component 1. Furthermore, a feature of the structure is that at least one of the lead terminals 3a, 3b does not pass through the center of the ceramic component 1. The respective structures will be described specifically as follows.
The various ceramic materials, such as dielectric ceramic, semiconductor ceramic, and other ceramic materials, can be used for the ceramic component 1. Particularly, under a condition that the temperature of semiconductor ceramic increases due to energization, the heat propagation may be affected by the flatness of the surface mounting, thus, the invention is effective for this case. In addition, for semiconductor ceramic 1, PTC thermistor material, such as Barium titanate-based semiconductor ceramic, and the like, or NTC thermistor material which is obtained by mixing the respective material, such as Mn, Ni, Co, Fe, Ti, Zn, and the like, can be utilized.
Furthermore, the metals, such as Ag, Ag-Pd, and their alloy, or metals, such as Ni, Al, Cu, and the like, and their alloy, can be used for the external electrodes 2a, 2b formed on the surfaces of the ceramic component 1. They can be formed by coating paste used for the external electrodes on the surfaces of the ceramic component 1 and heating the past, however, various methods, such as sputtering, plating, and the like, can be used. The external electrodes can be formed on two entire main surfaces of the ceramic component 1, and it can also be formed as Fig. 1A, that is, it can be formed to have a shape as same as the shape of the ceramic component 1 but slightly smaller than the peripheral of two main surfaces of the ceramic component 1.
As shown in Fig. 1A, one end of each of the lead terminals 3a, 3b can be connected with the external electrodes 2a, 2b via solder, and the like, and the lead terminals 3a, 3b can be outputted externally from the ceramic component 1. Herein, 2 lead terminals 3a, 3b can be prepared, the lead terminal 3a traverses over the upper surface of the ceramic component 1, the front ends of the lead terminal 3a can be outputted from the ceramic component 1 at different directions, respectively. Furthermore, the lead terminal 3a can be soldered and fixed on the external electrode 2a. Furthermore, the lead terminal 3b traverses over the lower surface of the ceramic component 1, the front ends of the lead terminal 3b can be outputted from the ceramic component 1 at different directions, respectively. Furthermore, the lead terminal 3b can be soldered and fixed on the external electrode 2b. In this way, the ceramic component 1 can be supported by the lead terminals 3a, 3b at the upper and lower surfaces. Herein, when it traverses over the ceramic component 1, at least the lead terminal 3a located at the suction surface of the suction machine (upper side in Fig. 1) does not pass through the center of the ceramic component 1. Specifically, the lead terminal 3a is not arranged in a linear way, rather, it is arranged as a "U" bend, thereby the lead terminal 3a can be outputted from the ceramic component 1 in a way that it bypasses the center portion of the ceramic component 1. Herein, the lead terminal 3b formed on the lower surface of the ceramic component 1 can be maintained in a way that it passes directly through the center portion of the surface of the ceramic component 1 along a straight line. In such an arrangement, the unnecessary protrusion will not be formed on the center portion of the ceramic component 1, that is, at the position sucked by the suction machine when it is mounted automatically, and a flat area can be obtained on the surface of the ceramic component 1. Furthermore, one end of each of the lead terminal 3a, 3b located at the substrate side, that is, the end at mounting side, can be bended to the outside along the substrate. The lead terminals can be fixed by using such a structure, that is, they are not inserted into the openings on the substrate, rather, they are mounted onto the substrate by surface mounting. Particularly, the lead terminals 3a, 3b traverse over the ceramic component 1, and outputted by 4 terminals, therefore, sufficient stability can be obtained with respect to the substrate, and the ceramic component 1 can be fixed at a flat state. Furthermore, in the invention, "4 terminals" refers to that the number of the portions outputted externally from the ceramic component 1 is 4. It does not refer to that the number of the lead terminals themselves are 4. That is, although 2 lead terminals are used, however, the number of the lead terminals outputted externally from the ceramic component is still 4 terminals.
Herein, the method that at least one lead terminal does not pass across the center portion of the surface of the ceramic component 1 is not limited as that shown in Fig. 1A. For example, as shown in Fig. 1B, the lead terminals can be bended at two places to form right angles to allow one lead outputted from ceramic component 1 at different positions. Under such a condition, in order to support the ceramic component 1 by two lead terminals 3a, 3b, preferably, the output position of the lead terminals 3a, 3b must be adjusted to a balanced position. For example, as shown in Fig. 1B, if the output positions of the lead terminals 3a is at up right and bottom left of the drawing, the output positions of the lead terminal 3b is at up left and bottom right of the drawing, preferably, the distance between the terminals outputted at the same direction is the same.
Herein, a cover layer 4 can be formed on the surface of the ceramic component 1, however, it is not limited by this. Under a condition that the cover layer has been formed, the ceramic component 1 can be protected form the peripheral environment, such as temperature, humidity, and the like. Furthermore, by forming a cover layer 4, sometimes, the flatness of the surface of the ceramic component 1 can be adjusted by the thickness of the resin. The resin, such as epoxy resin, rubber member, and the like, can be used as a cover layer 4, however, it is not limited by this.

[The function and result]

By using a structure as described in Embodiment 1, when the leads are soldered, the leads do not pass through the center portion of the surface of the ceramic component on at least one surface of the ceramic component, thereby the center portion of at least one surface of the ceramic component will be flat when the leads are soldered, under a condition that the suction machine is used when mounting automatically, the dropping will not be happened, and the mounting operation utilizing automatic suction can be realized.
Furthermore, one end of each of the lead terminals at the mounting side of the lead type electronic component can be bended and mounted to the substrate, thereby the surface mounting can be carried out with the stability of the height position of the lead type electronic component maintained.

Embodiment 2

[Structure]

By comparing Embodiment 1 with Embodiment 2, the lead terminal 3b on the lower surface of the ceramic component 1 in Fig. 1A is outputted in a straight line shape, however, in Fig. 2, not only the lead terminal 3a located on the upper surface of the ceramic component 1, but also the lead terminal 3b located on the lower surface of the ceramic component 1 do not pass through the center portion of the surface of the ceramic component 1. Other structures of Embodiment 1 and Embodiment 2 are the same. The description of the part having the same structure as that of Embodiment 1 will be omitted.

[The function and result]

By using the structure in Embodiment 2, both of the leads formed on two surfaces are bended to bypass the center portion of the surfaces of the ceramic component 1 and outputted, thus, flat surfaces can be formed, and the ceramic component can be fixed excellently by using the bended leads of the upper surface and the lower surface. And the increased cost due to the requirement of adding fixtures or processes to maintain the balance of the chip can be avoided.
Of course, the same result as that in Embodiment 1 can be obtained in Embodiment 2.

Embodiment 3

[Structure]

Furthermore, Fig. 3A is a modification of Fig. 1A, Fig. 3B is a modification of Fig. 1B. In Fig. 3A and Fig. 3B, the shape of the lead terminal 3a located on the upper surface of the ceramic component 1 are bended to a shape along the outline of the ceramic component 1. Herein, because the ceramic component 1 has a disc shape, the lead terminal 3a may also be bended to have a circle shape along the peripheral of the ceramic component 1, and can be outputted while not passing through the center portion of the surface of the ceramic component 1. Apart from this, it is the same as that in Embodiment 1.
In addition, under a condition of the example, the shape of the lead terminal 3b located on the lower surface of the ceramic component 1 can also be bended to have a shape along the outline of the ceramic component 1, or the lead terminal 3b can pass through the center of the ceramic component 1 along a straight line.

[The function and result]

If the lead terminals are soldered and superimposed on the ceramic component, and the lead terminal has a shape along the peripheral of the ceramic component, then the flat area of the center portion of the ceramic component can be expanded, the dropping under the condition of using suction machine when automatic mounting can be avoided reliably, and the practical result can be obtained.
Of course, the same result as that in Embodiment 1 can be obtained in Embodiment 3.

Embodiment 4

[Structure]

In addition, in Fig.4A, two lead terminals 3a, 3b may be prepared for the lead type electronic component having 4 terminals, as Fig. 1~Fig. 3, however, by comparing Fig.4A with Fig. 1 ~ Fig. 3, the difference is that with respect to ceramic component 1, the front ends of the same lead terminal can be outputted at the same direction. Specifically, the lead terminals 3a, 3b are bended to avoid the center portion of the surface of the ceramic component 1, and the front ends can be outputted at the same direction with respect to the ceramic component 1. Furthermore, with respect to the ceramic component 1, the output direction of the lead terminals 3a can be opposite to the output direction of the lead terminals 3b. The remaining structure can be the same as that of Embodiment 1.
Furthermore, in Fig. 4B, the lead terminals 3a, 3b may also be bended to "U" shape as that in Fig. 4A, however, the front ends of the lead terminals 3a, 3b can be soldered on the surface of the ceramic component 1 but bypassed the center portion of the ceramic component 1, and the continuous portion of the lead terminals 3a, 3b can be mounted on the substrate. The remaining structure is the same as that in embodiment 1.

[The function and result]

Having such a structure, the bending of the lead terminal will be simple, and it will be easy to produce, furthermore, the clamping force between the upper and lower lead terminals is large, and the ceramic component can be stable.
Furthermore, according to the fourth aspect of the invention, 2 lead terminals can be outputted at the same direction, respectively, thereby it is easy to make the height position of the bended lead terminals to be consistent, or the deviation of the height position is smaller. Thus, the flatness of the substrate when mounting can further be improved.
Of course, the same result as that in Embodiment 1 can be obtained in Embodiment 4.

Embodiment 5

[Structure]

Furthermore, 4 lead terminals 3a~3d prepared in advance can be used for the lead type electronic component of Fig. 5. Specifically, the lead terminals 3a, 3b are connected on the upper surface of the ceramic component 1, and the respective front ends located at one side of the ceramic component 1 can be soldered and fixed at a position that avoiding the center portion on the surface of the ceramic component 1. Furthermore, the respective front ends located at the substrate side, that is, the respective front ends located at the mounting side, can be bended toward outside. Furthermore, the lead terminals 3c and 3d are connected on the lower surface of the ceramic component 1, wherein the respective front ends located at one side of the ceramic component 1 can be soldered and fixed at a position that avoiding the center portion on the surface of the ceramic component 1. Furthermore, the respective front ends located at the substrate side can be bended toward outside.
Other structure is the same as that in embodiment 1.

[The function and result]

The following result can be obtained by using such a structure. 2 lead terminals among 4 lead terminals can be outputted from the upper surface of the ceramic component at one direction, the remaining two lead terminals can be outputted from the lower surface of the ceramic component at a direction opposite to that of the above two lead terminals, and the respective lead terminals are independent, thus, they can be arranged to avoid completely the center portion on the surface of the ceramic component. Furthermore, it is not necessary to bend one lead terminal on the ceramic component in order to avoid the center portion on the surface of the ceramic component, and the producing process is simple. Furthermore, the height position of 2 lead terminals outputted at the same direction is the same, and the processing of the bending position of the respective lead terminals can be performed easily.

Embodiment 6

[Structure]

Fig. 6A is a modification of Fig. 1A, Fig. 6B is a modification of Fig. 5. For the lead type electronic components shown in Fig. 6A and Fig. 6B, the surfaces of the ceramic component 1 can be covered by a heat shrinkable tube 6. The said heat shrinkable tube 6 refers to a tube shaped resin cover material, which can be shrunk under heating. By comparing with a condition that the surface of the ceramic component 1 being covered by normal resin, the shrinking force will be lager under the heat shrinkable tube condition, thus, it has the result of adsorbing and mitigating the unflatness of the surface of the ceramic component 1. Furthermore, its durability is optimum. Other structure is the same as that of Embodiment 1 or Embodiment 5.

[The function and result]

By using such a structure, the height difference produced easily on the surfaces of the ceramic component can be adsorbed, and the flatness on the surfaces of the ceramic component can further be improved.
Planarity can be realized easily. Furthermore, because the heat shrinkable material has elasticity, the stress is uneasy to be applied on the ceramic component, therefore the durability of the product is optimum.
PFA, FEP, PTFE, and the like, can be used for the heat shrinkable tube, however, it is not limited by this.

Embodiment 7

Fig. 7A is a modification of Fig. 5, Fig. 7B is a modification of Fig. 7A. In Fig. 7A, one end of each of the lead terminals 3a, 3b located on the upper surface of the ceramic component 1 can be bended to coincide with the outline of the ceramic component 1, and the other end can be outputted externally from the ceramic component 1. Herein, the ceramic component 1 has a disc shape, therefore, one end of each of the lead terminals 3a, 3b can be bended along the peripheral of the ceramic component 1 to have a circle shape, and the lead terminals 3a, 3b can be formed in a manner that they do not pass through the center portion of the surface of the ceramic component 1. Furthermore, another end of each of the lead terminals 3a, 3b can be outputted at opposite positions where the ceramic component 1 is sandwiched between, respectively. On the other hand, one end of each of the lead terminals 3c, 3d on the lower surface of the ceramic component 1 can be bended to coincide with the outline of the ceramic component 1, and another end can be outputted externally from the ceramic component 1. Herein, another end of each of the lead terminals 3c, 3d can be outputted at positions that rotating about 90 degrees with respect to another end of the lead terminals 3a, 3b. Finally, another end of each of the lead terminals 3a~3d can be outputted at positions that rotating 90 degrees with each other (0 degree, 90 degrees, 180 degrees, 270 degrees).
Fig. 7B is a modification of Fig. 7A. In Fig. 7B, the lead terminals 3a, 3b located on the upper surface of the ceramic component 1 is the same as that in Fig. 7A. The lead terminal 3e located on the lower surface of the ceramic component 1 of Fig. 7B has a straight line shape and goes directly through the center portion of the surface of the ceramic component 1. Herein, the lead terminal 3e can be outputted from the ceramic component 1 at a position with respect to another end of each of the lead terminals 3a, 3b at a direction of 90 degrees. That is, another end of each of the lead terminals 3a, 3b and two ends of 3e can be outputted at positions that rotating 90 degrees with each other (0 degree, 90 degrees, 180 degrees, 270 degrees).
In addition, herein, the output positions of the lead terminals are the positions that offsetting every 90 degrees, however, not necessarily 90 degrees. The output angle can be changed based on the mounting area.
In Fig. 7A and 7B, the cross sectional view has a T shape, however, an opening may be formed at a position near the center of T but at the left side of the center of T, that is, the opening in the cross sectional view corresponds to the gap formed between 2 lead terminals in the top view.

[The function and result]

Under the condition that 4 lead terminals or 3 lead terminals are used, if they are formed to have a peripheral shape of the ceramic component, then the flat area in the center portion of the surface of the ceramic component will be larger, and the following practical results can be obtained, that is, the problem of dropping when using the suction machine during automatic mounting can be avoided reliably.
Furthermore, because the terminals are outputted from the ceramic component at 4 directions, by comparing this with the terminals outputted from 2 directions, the mounting stability can further be improved.
Of course, the same result as that in Embodiment 1 can also be obtained in Embodiment 7.

Embodiment 8

[Structure]

Fig. 8A is a modification of Fig. 1A. In Fig. 8A, the lead terminals 3a, 3b and the external electrodes 2a, 2b formed on the ceramic component 1 can be connected by soldering. This portion can be referred to as a welding portion 5. Preferably, the welding portion 5 can be formed at the position apart from the positions where the lead terminals 3a, 3b outputted from the ceramic component 1.

[The function and result]

As a method for mounting the substrate by surface mounting, a known method is reflow mounting. In the reflow mounting, the solder is heated to about 230~250° C at a melt state for substrate mounting. At this time, the lead terminals 3a, 3b and the external electrodes 2a, 2b formed on the surface of the ceramic component 1 can be connected by the solder, however, under the condition that the lead type electronic components are mounted by reflow, the thermal history can be applied under the state that the cover layer 4, such as heat shrinkable tube or resin layer, are formed, therefore, for the soldering position, the solder under the cover layer 4 is melted, and the solder will flow out from the portion that the lead terminals 3a, 3b being outputted from the cover layer. As the application of the invention, the position of the welding portion 5 can be separated from the position of the portion where the lead terminals 3a, 3b are outputted from the ceramic component 1, thereby even though the solder for soldering the lead terminals 3a, 3b and the external electrodes 2a, 2b is melted due to the thermal history, the melted solder can still retain inside the cover layer 4 to prevent the solder from flowing out at the output portion where the lead terminals 3a, 3b outputted from the ceramic component 1.

[Structure]

Furthermore, Fig. 8B is a modification of Fig. 5, it is a more preferred shape. In Fig. 8B, a bending portion 3E exists between the welding portion 5 of the lead terminals 3a, 3b and the portion where the lead terminals 3a, 3b being outputted from the ceramic component 1.

[The function and result]

In this way, a bending portion 3E can be prepared for the lead terminals 3a, 3b thereby when the problem which is the same as the above problem is occurred, the melted solder produced by heating can be retained in the bending portion 3E. Thus, the solder can be prevented from flowing out at the portion where the lead terminals 3a, 3b being outputted from the ceramic component 1. The shape of said bending portion is not limited by the Embodiment, it can be S type or W type, and the like, as long as a bending portion. As shown in Fig. 7B, under a condition that there are several bending portions, such as "Z" shape, and the like, the solder can be prevented reliably from flowing out, thus, it is the more preferred one.

Embodiment 9

[Structure]

Fig. 9A is a modification of Fig. 8A, Fig. 9B is a modification of Fig. 5. In Fig. 9A, one end of each of the lead terminals 3a, 3b located at the substrate side can be bended toward the internal side (the center portion side) along the substrate. Apart from this, the structure is the same as that in Fig. 8A. Furthermore, in Fig. 9B, one end of each of the lead terminals 3a~3d located at the substrate side can be bended toward the internal side along the substrate. Apart from this, the structure is the same as that in Fig. 5.

[The function and result]

By using such a structure, when surface mounting is performed on the substrate surface, the mounting area will be smaller, and it is preferred for the usage of the minimum mounting area of the electronic devices.
Furthermore, under the condition that the mounting area is not limited, one end of each of the lead terminals 3a~3d located at the substrate side can be bended partly toward the internal side, and the other portion can be bended toward the external side, and the like, and the various combinations could be applied based on the conditions.

Embodiment 10

[Structure]

Fig. 10 is a modification of Fig. 5. In Fig. 10, seeing from the plane direction of the ceramic component 1, one end of each of the lead terminals 3a~3d located at the substrate side can be bended at a direction that perpendicular with the output direction of the lead terminals 3a~3d. Specifically, it is perpendicular with the long side direction of the lead terminals 3a~3d, and it is bended in a manner that from the center portion side of the ceramic component 1 extending towards the outside. The remaining is the same as that of Fig. 5.

[The function and result]

By forming such a structure, when surface mounting is performed for the substrate, the mounting area can be increased, and can be soldered on the substrate reliably, thus, the mounting strength can be improved. In the usage that there is no restriction on the mounting area, the above method is very effective.
As described above, the invention has been described based on the above Embodiments, however, the invention is not limited by the contents of the above Embodiments, appropriate modifications can be made.

The description of the reference numbers

1: ceramic component
2a, 2b: external electrodes
3a, 3b, 3c, 3d, 3e: lead terminals
3E: bending portion
4: cover layer
5: welding portion
6: heat shrinkable tube

Claims

A lead type electronic component comprises:
a ceramic component;

external electrodes formed on two main surfaces of said ceramic component; and

lead terminals electrically connected with said external electrodes respectively, said lead type electronic component is characterized by that:
said ceramic component is supported at the upper and lower surfaces by utilizing said lead terminals, one end of said lead terminals at the mounting side can be bended,

the lead terminal located on at least one surface of said ceramic component can be formed in a manner that it does not pass through the center portion of the surface of said ceramic component.
The lead type electronic component according to Claim 1, wherein, for said lead terminals, 2 lead terminals outputted from two ends of said ceramic component respectively in a manner that they pass over the upper and lower surfaces of said ceramic component respectively, thereby four terminals can be formed, the lead terminals located on two main surfaces of said ceramic component can be formed in a manner that they do not pass through the center portion of the surfaces of said ceramic component.
The lead type electronic component according to Claim 1 or 2, wherein, said lead terminal formed on the surface of said ceramic component has a shape that goes along the peripheral of said ceramic component.
The lead type electronic component according to Claim 1, wherein, for said lead terminals, 2 lead terminals can be bended respectively, so that they do not pass through the center portion on two main surfaces of said ceramic component, and can be outputted from said ceramic component at the same direction, the upper lead terminal outputted from the upper surface of said ceramic component and the lower lead terminal outputted from the lower surface of said ceramic component can be outputted at different directions with each other.
The lead type electronic component according to Claim 1, wherein, for said lead terminals, 2 lead terminals among 4 lead terminals are formed on the upper surface of the ceramic component and can be outputted from said ceramic component at one direction in a manner that they do not pass through the center portion on the surface of said ceramic component, the remaining 2 lead terminals are formed on the lower surface of the ceramic component and can be outputted from said ceramic component at a direction which is opposite to the output direction of said 2 lead terminals formed on the upper surface.
The lead type electronic component according to Claim 1, wherein, for said lead terminals, 2 lead terminals among 4 lead terminals are formed on the upper surface of the ceramic component and can be outputted from said ceramic component in a manner that they do not pass through the center portion on the surface of said ceramic component, the remaining 2 lead terminals are formed on the lower surface of said ceramic component,
said lead terminals can be bended respectively, when seeing said ceramic component from the top, one end of said lead terminals at the mounting side can be perpendicular to the output direction of said lead terminals outputted from said ceramic component.
The lead type electronic component according to Claim 1, wherein, 2 lead terminals can be formed at the upper surface side of said ceramic component, one end of each of the 2 lead terminals can be formed on the upper surface of said ceramic component in a manner that they do not pass through the center portion of said ceramic component, another end of each of said 2 lead terminals can be outputted from positions opposite to each other with regard to the center of said ceramic component,
at least one lead terminal formed at the lower surface side of said ceramic component and outputted externally from said ceramic component has an output direction which is different from the output direction of 2 lead terminals formed at said upper surface side.
The lead type electronic component according to Claim 1 or 5, wherein, said lead terminals and said surfaces of said ceramic component having external electrodes formed thereon can be covered by a heat shrinkable tube.
The lead type electronic component according to Claim 1 or 5, wherein, said lead terminals and said surface of said ceramic component having external electrodes formed thereon can be covered by a cover layer, said lead terminals and the external electrodes formed on the surface of said ceramic component can be connected by solder to form a welding portion, said welding portion can be formed at a position which is separated from a portion where said lead terminals outputted from said ceramic component.
The lead type electronic component as Claim 1 or 5, wherein, said lead terminals and said surface of said ceramic component having external electrodes formed thereon can be covered by a heat shrinkable tube or resin, said lead terminals and the external electrodes formed on the surface of said ceramic component can be connected by solder to form a welding portion, a bending portion can be formed between said welding portion and the portion of the lead terminals where said lead terminals being outputted from said ceramic component.
The lead type electronic component according to Claim 1 or 5, wherein one end of said lead terminals at the mounting side can be bended toward the center portion of said ceramic component.