JPH0717169Y2 - Ceramic electronic components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a ceramic electronic component such as a dielectric filter, which is composed of a combination of a case having conductivity and a main body of the ceramic electronic component.

[Prior Art] A conventional dielectric filter is composed of a combination of a rectangular parallelepiped ceramic dielectric block and a metal case as disclosed in, for example, Japanese Utility Model Laid-Open No. 63-26106 (Japanese Patent Application No. 61-117769). Become. The dielectric block has a resonance hole formed from one end face toward the other end face. An inner conductor film is formed on the inner wall of the resonance hole, and an outer conductor film is formed on the outer peripheral surface of the dielectric block except one end surface (open end surface). The metal case is electrically and mechanically connected to the outer conductor film of the dielectric block by soldering.

[Problems to be Solved by the Invention] When soldering the metal case to the outer conductor film of the dielectric block, a solder paste is applied to the outer conductor film or the metal case, and the solder paste is reflowed. In order to increase the strength of the solder bond of the metal case, it is necessary to increase the thickness of the solder layer. In order to provide a thick solder layer, the gap between the outer conductor film and the metal case must be large. Even if the gap between the two is large, if the entire gap between the two is filled with solder, the electrical connection of the outer conductor film to the metal case (ground) is satisfactorily achieved. However, it is extremely difficult to form a thick solder layer uniformly over the entire area between them, and a space is created between them. Since this space has a relatively large width corresponding to the gap between the two, the ground property of the outer conductor film is deteriorated, spurious emission (unnecessary frequency emission) is generated, and the attenuation characteristic is deteriorated.

This type of problem can occur in other ceramic electronic components as well.

Therefore, an object of the present invention is to provide a ceramic electronic component that can achieve good and easy connection between the ceramic electronic component body and the case.

[Means for Solving the Problems] The present invention for achieving the above object comprises a conductive case and a ceramic electronic component main body housed in the case, and at least one outer peripheral surface of the main body is conductive. It is formed in a planar shape by layers, and the case has a planar surface that faces substantially all of the planar outer peripheral surface of the main body, and the planar surface of the case has the planar surface. In a ceramic electronic component in which the flat outer peripheral surface of a main body is bonded by solder, a recess is formed in the flat planar surface of the case so as to face only a part of the flat outer peripheral surface of the main body. The recess is filled with solder so that the case can be coupled to the main body, and the flat surface of the case and the flat outer surface of the main body other than the recess are covered. The present invention relates to a ceramic electronic component, characterized in that a solder layer thinner than the solder layer in the recess is formed between the peripheral surface and the peripheral surface.

[Operation and Effect of the Invention] The recessed portion partially provided on the plane surface of the case according to the present invention is an escape area for the molten solder interposed between the plane surface of the case and the plane outer peripheral surface of the main body. Work as. Therefore, a thin and excellent solder layer is formed between the flat surface of the case and the flat outer peripheral surface of the main body, and the recess is sufficiently filled with solder. Since the solder layer in the recess is thicker than the solder layer between the plane surface of the case and the plane outer peripheral surface of the body, a firm bond between the case and the body is achieved. Since the flat surface of the case other than the recess is connected to the flat outer peripheral surface of the main body by a thin solder layer, low impedance connection is achieved and the ground characteristics are improved.

[Embodiment] Next, a horizontal dielectric filter according to an embodiment of the present invention will be described with reference to FIGS.

This dielectric filter comprises a combination of a metal case 1 shown in FIG. 1 and a dielectric filter body 2 shown in FIG. As is apparent from FIGS. 4 and 5, the dielectric filter body 2 is provided on the ceramic dielectric block 6 having two resonance holes 3 and 4 and the coupling hole 5, and on the wall surfaces of the resonance holes 3 and 4, respectively. The inner conductor film 7, the outer conductor film 8 that can be soldered provided on the outer peripheral surface of the dielectric block 6, the coupling capacitors 9 and 10 inserted into the resonance holes 3 and 4, and the coupling capacitor 9, A circuit board 13 to which 10 is connected and terminals 11 and 12 are provided. The resonance holes 3 and 4 are formed so as to penetrate from one end surface 14 of the dielectric block 6 to the other end surface 15. The outer conductor film 8 made of a layer coated with silver paste and baked is provided on the four side faces 16, 17, 18, 19 and the other end face 15. 4 side faces 16-19 and end faces
Since 14 and 15 are substantially flat, the four side surfaces and the two end surfaces of the dielectric filter body 2 are also substantially flat. The four sides of the dielectric filter body 2 and
One end surface (short-circuit surface) is composed of the outer conductor film 8.

The metal case 1 is formed so as to accommodate the dielectric filter body 2, and as shown in FIG. 1, comprises a bottom surface portion 20 and four side surface portions 21, 22, 23, 24 and a lid portion 25 which are continuous with each other. And is formed by bending a metal plate that can be soldered. A window 26 is provided at the boundary between the lid 25 and the side surface 23.
The hinge portion 27 is provided so as to be easily bent. Further, an engaging portion 28 is provided at the central tip of the lid portion 25. The engaging portion 28 is a portion for engaging the protruding portion 29 of the side surface portion 24 and fixing the lid portion 25. Metal case 1
Each of the bottom surface portion 20 and the lid portion 25 is provided with two recesses 30 functioning as solder escape portions. Metal case 1
Four ground connection terminals 31 are provided so as to project from the side surface portions 21 and 22 of the.

When the dielectric filter main body 2 and the metal case 1 are integrated, a solder paste (cream solder) is applied to the outer peripheral surface of the dielectric filter main body 2, that is, the outer conductor film 8, and this is accommodated in the metal case 1 and the lid. The part 25 is heated after being closed as shown in FIGS. As a result, the solder paste is reflowed, and the molten solder flows into the recess 30. As shown in the enlarged view of FIG. 6, the thickness of the solder 32 is thick in the recess 30, so that the outer conductor film 8 and the metal case 1 are firmly bonded by the solder 32 in the recess 30. In a portion other than the concave portion 30, the solder 32 is thinly interposed in a slight gap between the metal case 1 and the outer conductor film 8. Therefore, even if a non-filled portion of the solder 32, that is, a void occurs between the metal case 1 and the outer conductor film 8, the deterioration of the attenuation characteristics due to spurious radiation due to the deterioration of the ground characteristics is small.

[Modification] The present invention is not limited to the above-described embodiments, and the following modifications are possible, for example.

(1) In the embodiment, the bottom surface portion 20 and the lid portion 25 of the metal case 1 are provided with the recesses 30 and the solder 32 is filled therein.
It is also possible to form the recesses 2 and 23 that are equivalent to the recesses 30.
It is also possible to provide the recess 30 only on one of the bottom surface portion 20 and the lid portion 25.

(2) The outer shapes of the dielectric block 6 and the dielectric filter main body 2 can be formed in a quadrangular prism type, a triangular prism type, a chamfered type, or the like.

(3) The present invention can be applied to a dielectric resonator having only one resonance hole, a multistage dielectric filter having three or more resonance holes, and various electronic parts having ceramics.

(4) The planar shape of the recess 30 can be various shapes such as a circle, a quadrangle, a cross, an American shape, a triangle, and a ring.
In addition, a plurality of recesses 30 can be regularly or irregularly distributed.

(5) The side surface of the dielectric filter body 2 can be elastically sandwiched between the pair of surfaces of the metal case 1.

(6) The hinge portion 27 can be formed with a groove instead of the window 26.

[Brief description of drawings]

1 is a perspective view showing a metal case of a dielectric filter according to an embodiment of the present invention, FIG. 2 is a perspective view showing a dielectric filter body housed in the metal case of FIG. 1, and FIG. 1 is a plan view showing the dielectric filter after the main body of FIG. 2 is housed in the metal case of FIG. 1, FIG. 4 is a sectional view taken along line IV-IV of FIG. 3, and FIG. 5 is VV of FIG. FIG. 6 is a sectional view showing a part of FIG. 4 in an enlarged manner. 1 ... Metal case, 2 ... Dielectric filter body, 6 ...
Dielectric block, 8 ... Outer conductor film, 30 ... Recess, 32 ...
solder.

Claims (1)

[Scope of utility model registration request] 1. A case comprising a conductive material and a ceramic electronic component main body housed in the case, wherein at least one outer peripheral surface of the main body is formed in a planar shape by a conductive layer, and the case is the main body. Has a flat surface facing substantially all of the flat outer surface, and the flat outer surface of the main body is bonded to the flat surface of the case by soldering. In the ceramic electronic component, a recess is formed on the plane surface of the case so as to face only a part of the plane outer peripheral surface of the body, and the case can be coupled to the body. As described above, the recess is filled with solder, and a solder layer thinner than the solder layer of the recess is provided between the flat surface of the case and the flat outer peripheral surface of the main body other than the recess. Ceramic electronic component, characterized by being made.