JP2888204B2 - Electronic components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount type electronic component assembled by a heat treatment such as reflow.

[0002]

2. Description of the Related Art As surface mounting of electronic components progresses,
There has been an increasing demand for high flatness of the bottom surface of the electronic component mounted on the set side.

Conventionally, electronic components are provided with a plurality of circuit electrodes on the surface of a mounting board, and circuit components such as chip capacitors connecting the circuit electrodes are mounted by reflow soldering. I have.

In such an electronic component, a ground electrode is provided on substantially the entire back surface of the mounting substrate in order to enhance the shielding property of the electronic component.

[0005]

However, since there is a difference between the area of the circuit electrode and the area of the ground electrode on the front and back surfaces of the mounting board, when the circuit components are reflow mounted, the heat expands to the electrodes on the front and back surfaces. A difference is generated, and the mounting substrate warps toward the circuit electrode side, and the circuit components are soldered in that state, so that there is a problem that the bottom surface of the completed electronic component warps.

Accordingly, an object of the present invention is to solve such a problem and to provide a surface mounting type electronic component having high surface accuracy.

[0007]

In order to achieve this object, the present invention relates to a method for forming a ground electrode on a back surface of a mounting substrate.
At least one between circuit electrodes connected by circuit components at
These are arranged at the positions corresponding to the two.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to an electronic device having a mounting substrate having a plurality of circuit electrodes on a front surface and a ground electrode on a back surface, and a circuit component for connecting the circuit electrodes. The circuit component within the ground electrode
At least one between the circuit electrodes connected by
An electronic component having a non-electrode forming portion provided at a corresponding position, wherein the non -electrode forming portion has an effect of efficiently absorbing a difference in expansion between the front and back surfaces of a mounting substrate.

According to a second aspect of the present invention, there is provided a mounting substrate having a plurality of circuit electrodes on a front surface and a ground electrode on a rear surface;
In an electronic component having a circuit component for connecting between the circuit electrodes, the electronic component is intermittently turned off so as to surround a central portion of the mounting substrate.
An electronic component having a pole forming portion ,
The non-electrode formation part makes the difference in expansion between the front and back of the mounting board effective.
Absorbs efficiently and keeps the ground electrode
It has the effect that it can be used.

According to a third aspect of the present invention, there is provided the electronic component according to the first or second aspect, wherein a width of the non-electrode forming portion is smaller than a thickness of the mounting substrate. This has the effect that the surface accuracy of the electronic component can be improved without impairing the shielding properties of the electronic component.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a dielectric filter which is one of electronic components used for a mobile phone and the like.

Reference numeral 1 denotes a mounting substrate, which is made of glass epoxy resin or the like, and has circuit electrodes 2, 3, 4 on its surface.
Is provided. On the back surface, an earth electrode 5 and an input / output electrode 6 are provided as shown in FIG. The circuit electrode 2 is connected to the input / output electrode 6, and the circuit electrode 4 is connected to the ground electrode 5 on the side surface of the mounting board 1.

The circuit electrode 2, the circuit electrode 3, the circuit electrode 4, the ground electrode 5, and the input / output electrode 6 are generally made of gold or copper in consideration of electric conductivity, erosion, etc. Is performed by etching or the like.

Referring back to FIG. 1, reference numeral 7 denotes a dielectric resonator used as one of the circuit components. An outer peripheral electrode 7b is provided on an outer peripheral surface excluding the open end surface 7a, and an inner peripheral electrode 7 is provided on an inner peripheral surface of the through hole 7c.
d is provided. Such a dielectric resonator 7 is reflow-mounted on a portion indicated by a broken line of the mounting substrate 1, and the open end face 7 a side of the inner peripheral electrode 7 d is connected to the circuit electrode 3 by a signal terminal 8.

Reference numeral 9 denotes a chip capacitor used as one of circuit components, which is mounted as indicated by a broken line on the mounting board 1 and connects the circuit electrodes 2 and 3 and the circuit electrodes 3 and 3.

As shown in FIG. 2, the ground electrode 5 of the mounting substrate 1
Inside, a non-electrode forming portion 10 is provided. Since the non-electrode forming portion 10 is provided in the ground electrode 5, the difference in thermal expansion between the electrodes on the front and back surfaces of the mounting board 1 due to reflow mounting or the like can be reduced as shown in FIG. The area accuracy in the above can be improved.

The non-electrode forming portion 10 is provided at a position corresponding to between the circuit electrodes 2 and 3 connected by the circuit component 9 shown by a broken line. This is the circuit electrodes 2 and 3
By positively adjusting the position of the end of the ground electrode 5 to the ground, it is possible to suppress the difference in thermal expansion between the electrodes when the circuit component 9 is mounted by reflow soldering. Even if it is attached, it is possible to prevent the bottom surface of the completed electronic component from warping.

Hereinafter, another embodiment will be described. However, the same components as those in the above-described embodiment will be denoted by the same reference numerals and the description will be simplified.

When a large number of circuit components 9 are arranged at random on the mounting board 1, if the non-electrode forming portions 10 are arranged so as to correspond to the circuit components 9 as in the above-described embodiment, the circuit components 9 The number of non-electrode formation parts 10 increases according to the number.
That is, the shielding property on the bottom surface of the electronic component is reduced. In such a case, as shown in FIG. 4, the non-electrode forming portion 10 provided on the back surface of the mounting substrate 1 is provided intermittently so as to surround the central portion of the mounting substrate 1.

When the non-electrode forming portion 10 is disposed as described above, the non-electrode forming portion 10 does not correspond to the circuit component 9 to be mounted, but is disposed so as to surround the central portion of the mounting substrate 1. 5 is prevented from expanding outward, and since the non-electrode forming portions 10 are intermittently arranged, a large number of independent earth electrodes 5 cannot be formed on the bottom surface of the electronic component. When connecting to the external circuit, stable characteristics can be ensured without inadvertently increasing the number of connection points.

Further, as shown in FIG.
Is set smaller than the thickness of the mounting substrate 1,
It is possible to prevent a signal flowing between the circuit electrodes 2 and 3 on the front surface from being emitted to the outside from the non-electrode forming portion 10 as much as possible.

[0022]

As described above, according to the present invention, connection is made by circuit components within the ground electrode provided on the back surface of the mounting board.
Position corresponding to at least one of the circuit electrodes
, The shielding of electronic components is impaired.
Bottom accuracy not is able to provide high surface mount electronic component.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a dielectric filter used as one embodiment of an electronic component of the present invention.

FIG. 2 is a bottom view of the dielectric filter.

FIG. 3 is a partial sectional view of a mounting substrate in the dielectric filter.

FIG. 4 is a bottom view of a dielectric filter according to another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mounting board 2 circuit electrode 3 circuit electrode 4 circuit electrode 5 ground electrode 7 circuit component (dielectric resonator) 9 circuit component (chip capacitor) 10 non-electrode forming part

Continuation of the front page (56) References JP-A-61-26284 (JP, A) JP-A-9-260795 (JP, A) JP-A-9-283867 (JP, A) JP-A-7-43018 (JP, A) , U) (58) Fields surveyed (Int. Cl. ⁶ , DB name) H05K 1 / 02,1 / 18

Claims (3)

(57) [Claims] 1. A plurality in the surface circuit electrodes, and the mounting substrate having a ground electrode on the rear surface, in the electronic component including a circuit component for connecting the circuit electrodes, before within the earth electrode
At least between the circuit electrodes connected by the circuit components;
An electronic component , wherein a non-electrode forming portion is provided at a position corresponding to one of the electronic components. 2. A central portion of a mounting board of an electronic component including a plurality of circuit electrodes on a front surface and a ground electrode on a rear surface and a circuit component for connecting the circuit electrodes.
An electronic component , wherein a non-electrode forming portion is provided intermittently so as to surround the electronic component. 3. The electronic component according to claim 1 , wherein a width of the non-electrode forming portion is smaller than a thickness of the mounting substrate.