JP2001156193A - Electronic component equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic component device for obtaining stable characteristics without spattering of metallic components, even at the time of welding a metallic cover body 4 with a sealing 5 arranging on the upper face of a ceramic substrate 2. SOLUTION: This electronic component device is constituted by welding a metallic cover body 4 for sealing a loading space 30 of an electronic component through a sealing conductor 5b formed in the surrounding of the upper face of a ceramic substrate 2a. In this case, a projecting part of a cross-section shaped is formed in a region inside a sealing conductor 2b of a ceramic substrate 2a, and the inner wall face of the metallic cover body 4 is abutted against an inclined side face 20a of the projecting part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component device in which electronic components such as a piezoelectric element, a quartz oscillator, and an IC chip are housed in a ceramic substrate and sealed with a metal cover.

[0002]

2. Description of the Related Art In a conventional electronic component device, an electronic component element such as a quartz oscillator is accommodated in a cavity of a ceramic substrate, and the inside of the cavity is hermetically sealed with a metal lid. FIG. 8 shows a cross-sectional view of a crystal oscillator which is an example of a conventional electronic component device. The conventional crystal oscillator 51 is
It is mainly composed of a ceramic substrate 52, a quartz oscillator 53, and a metal lid 54. The ceramic substrate 52 includes
The frame-shaped ceramic layers 52b, 52c, and 52d are laminated on the flat-plate-shaped ceramic layer 52a, thereby forming a cavity portion 521 having an open upper surface as a whole. On the inner wall surface of the cavity 521,
A step 522 for fixing the crystal unit 53 and achieving electrical connection is formed. Further, a sealing conductor film 57 such as a seal ring is arranged around the opening of the cavity portion 521 of the ceramic substrate 52. For example, the sealing conductor film 57 is fixed by brazing or the like on the sealing conductor film 57 formed around the opening of the cavity 521. A plating layer (not shown) formed by a plating technique is applied to the upper surface side of the sealing conductor film 57. Further, the metal lid 54 has a plating layer formed of Ni or the like on both surfaces, and a concave portion 54a is formed at a position corresponding to the convex portion at the tip of the ceramic layer 52d.

[0003] As a method of manufacturing such a crystal oscillator, a crystal oscillator 53 is housed in a cavity 521 of a ceramic substrate 52, and the metal lid 54 is placed on a sealing conductor film 57. They are placed, and both are heated by seam welding or the like to melt the plating layer on the sealing conductor film 57 on the ceramic substrate 52 side, and joined to the metal lid 54.

[0004]

However, in the structure of the conventional crystal oscillator as shown in FIG.
Surface irregularities of the sealing conductor film 57 formed on the second side,
If there is a burr or a warp in the contact portion of the concave portion 54a on the metal lid 54 side, the contact state of both the metal lid 54 and the sealing conductor film 57 is not uniform, and the seam in such a state. In the case of performing welding, even when an electric current is supplied, a discharge spark or scattering of a dissolved metal component (foreign matter) may occur in a gap between the metal lid 54 and the sealing conductor film 57. In particular, when the scattered metal components scatter inside the cavity portion 521, the metal components contaminate the inside of the cavity portion 521 and adhere to the crystal unit 53. When the metal component adheres to the crystal unit 53 as described above, the oscillation characteristics fluctuate greatly, and as a result, the predetermined characteristics cannot be obtained and the reliability is deteriorated. The present invention has been devised in view of the above-described problems, and has as its object when welding a metal lid on a ceramic substrate, metal components generated by welding are scattered inside an electronic component mounted. It is an object of the present invention to provide an electronic component device that effectively suppresses the operation of the electronic component device and enables a stable operation of the accommodated electronic component element.

[0005]

In order to solve the above-mentioned problems, an electronic component device according to the present invention comprises a frame-shaped sealing conductor (frame-shaped sealing conductor) formed on an outer peripheral portion of an upper surface of a ceramic substrate on which an electronic component element is mounted. An electronic component device in which a metal cover for sealing a mounting space for the electronic component is welded to the sealing conductor and the sealing conductor is attached to the inside of the sealing conductor of the ceramic substrate. A convex portion having a trapezoidal cross section is formed in the region, and the inner wall surface of the metal lid is brought into contact with the inclined side surface of the convex portion.

According to the structure of the present invention, since the inner wall surface of the metal lid is brought into contact with the inclined side surface of the ceramic substrate, the mounting space for electronic components on the ceramic substrate can be sealed. However, even when the contact state between both the metal lid and the sealing conductor is not uniform due to burrs or warpage at the welding position of the metal lid, the discharge spark or the melted metal component in the gaps of the electronic component may Prevents entry into the mounting space.

Further, an elastic member may be interposed between the inclined side surface of the ceramic substrate and the inner wall surface of the metal lid. With this elastic member, contact variation between the inclined side surface of the ceramic substrate and the inner wall surface of the metal lid can be suppressed, and the sealing performance of the mounting space for the electronic component can be improved.

Further, a convex portion having a rectangular parallelepiped cross section is formed in a region of the ceramic substrate inside the sealing conductor, and an inner wall surface of the metal lid is brought into contact with a side surface of the convex portion via an elastic member. A configuration in which these are performed may be used. As a result, a highly reliable electronic component device having good electric characteristics can be provided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a crystal oscillator which is an example of an electronic component device of the present invention will be described in detail with reference to the drawings. FIG.
FIG. 2 is a cross-sectional view of the crystal resonator of the present invention, FIG. 2 is a perspective view of a metal cover, FIG. 3 is an enlarged view of a main part of the metal cover, and FIG. FIG. 5 is an enlarged view of a main part of the ceramic substrate from which a body is omitted, and FIG. 5 is a plan view of the ceramic substrate from which a quartz oscillator is omitted.

In FIG. 1, a crystal oscillator 1 mainly comprises a ceramic substrate 2, a frame-shaped sealing conductor film 5b on the outer peripheral portion of the upper surface, a crystal oscillator 3 on the ceramic substrate 2, and a metal lid 4. Have been. The ceramic substrate 2 is formed using, for example, a well-known multi-layer wiring board technique, and includes ceramic layers (substrates) 2a, 2b,
2c are stacked in a convex shape.
A ceramic layer 2a having a trapezoidal cross section is formed in a region inside b. That is, the ceramic layer 2a disposed on the uppermost stage
Has a smaller area than the ceramic layer 2b on the bottom side, and in FIG. 5, W1 <W2, L
1 <L2. The elastic member 6 is formed on the inclined side surface 20a of the ceramic layer 2a. Thereby, the elastic member 6 is interposed between the inner wall surface of the metal lid 4 described later and the side surface 20a. As the elastic member 6, an elastic body such as silicon is used. In the present invention, an example in which the elastic member 6 is formed on the side surface 20a has been described. However, the present invention is not limited to this, and the elastic member 6 may be formed only by the side surface 20a without being formed.

Here, on the ceramic substrate 2a, a pair of electrode pads 24 to which the crystal unit 3 is mechanically fixed and electrically connected, and on the pair of electrode pads 24, respectively, the crystal unit 3 Is formed in a direction perpendicular to the longitudinal direction of the rod. Further, a terminal electrode 26 is formed on the bottom surface of the ceramic substrate 2. Further, the outer peripheral portion 21 of the ceramic substrate 2c is provided with a ring member 5a and a seal ring 5 having a sealing conductor film 5b adhered on the upper surface thereof.
Are formed. The electrode pad 24 is connected to a terminal electrode 26 by a conductor wiring 27 made of a via-hole conductor and a conductor conducted in the thickness direction of the ceramic substrate 2, and to a terminal electrode 29 by a via-hole conductor 28 conducted in the thickness direction of the ceramic substrate 2. Have been.

Such an electrode pad 24 and terminal electrode 2
Reference numerals 6 and 29 are formed by printing a conductive paste made of a high melting point metal material such as molybdenum or tungsten on a ceramic green sheet. The thickness is 30-60μm
And a Ni intermediate plating layer, a gold plating layer, or the like is appropriately applied to the surface. Also, via-hole conductors 27, 28
Is formed by forming a through hole in a ceramic green sheet and filling the through hole with the conductive paste described above.

Although not shown, the quartz oscillator 3 has a strip-shaped quartz substrate cut along a predetermined crystal axis, excitation electrodes formed on both main surfaces of the quartz substrate, and a quartz substrate from the excitation electrodes. It has a lead electrode extending to one end.

As shown in FIG. 2, the metal lid 4 is formed to have a convex upper side, and the periphery thereof includes a flat welded portion 4a and a welded portion 4a to be welded to the sealing conductor 5b. It is composed of a wall portion 4b that extends and rises upward and an upper surface portion 4c formed at the center of the metal lid 4 and substantially parallel to the bottom surface. The angle formed by the weld 4a and the wall 4b is obtuse.

As shown in the figure, the elastic member 6 formed on the inner wall surface of the wall portion 4b and the side surface 20a of the ceramic layer 2a abuts, and the metal lid 4 is closed while pressing the elastic member 6 from above. Therefore, the mounting space 30 of the crystal unit 3
Can be sealed tightly.

As shown in FIG. 3 (a), the material of the metal lid 4 is substantially composed of a metal plate 41 of a metal material such as Kovar or 42 alloy, and a plating layer 42 attached to both surfaces. Have been. For example, the metal plate 41 has a size of 50-100 μm.
m, and the surface plating layer 42 has a thickness of 5 to 5 m.
A 15 μm Ni plating layer or the like is used. This metal lid 4
Is placed on the ceramic substrate 2. At this time, the outer peripheral portion 4 a is arranged on the seal ring 5. Then, the outer peripheral end of the metal lid 4 is hermetically sealed by a method such as seam welding. When such a metal lid 4 is placed on the seal ring 5, the dimension of the flat portion on the seal ring 5 is such that a part of the outer edge is exposed from the periphery of the welded portion 4 a of the metal lid 4. Is determined.

It is desirable that the exposed width of the outer edge is about 50 to 300 μm. The reason is that the exposure width is 50
If the thickness is less than μm, an appropriate fillet is not formed at the end surface of the metal lid 4, and it is difficult to visually confirm the welded state. Also, if the exposed width exceeds 300 μm, the distance between the wall surface of the electronic component mounting space 30 and the end surface of the metal lid 4 becomes small, and cracks are likely to occur in the ceramic substrate 2.

Although the embodiment of the invention using the seal ring 5 has been described above, the present invention is not limited to this, and a configuration without the seal ring 5 may be used. That is,
FIG. 6 shows a configuration in which the metal lid 4 is placed on the sealing conductor 5b formed on the outer peripheral surface of the ceramic layer 2b and hermetically sealed by a method such as seam sealing. In this case, as shown in FIG. 3B, a brazing material layer 43 is applied to the lower surface of the metal cover 4 to which the metal plate 41 is joined, and a plating layer 42 is applied to the upper surface. It is good to use the one that has been worn. For the brazing material layer 43 on this joint surface, a low melting point brazing material, for example, an Au alloy, Sn, solder, an aluminum alloy, or the like is used. The low melting point brazing material 43 is used for the metal lid 4.
Is formed integrally with the metal plate 41 by cladding or the like during the processing. The thicknesses of the metal plate 41 and the plating layer are the same as described above, but the thickness of the brazing material layer 43 is, for example, 10 to 50 μm.

With such a configuration, a seal ring is not required, and the effect of cost reduction can be obtained. In addition, since the height of the seal ring can be reduced, the size of the component can be further reduced.

FIG. 7 is a sectional view showing still another embodiment. In this embodiment, among the ceramic substrates 2,
A substantially rectangular parallelepiped projection is formed inside the sealing conductor film 5b, and the welded portion 4a and the wall portion 4 of the metal lid 4 are formed.
The configuration in which the angle formed by b is a right angle and the inner wall surface of the wall portion 4b of the metal lid 4 is sealed with the elastic member 6 is shown.

The opening end side of the metal lid 4 is rounded. Thus, when the metal lid 4 is placed on the ceramic layer 2a, the displacement hardly occurs and the assembly is facilitated. Also in this case, the angle formed between the welded portion 4a of the metal lid 4 and the wall portion 4b is a right angle.

The electronic component device described above is assembled as follows. First, a conductive resin paste 2 containing Ag is formed on electrode pads 24 formed on the outer peripheral portion of the ceramic substrate 2.
51 and a conductive resin paste 251 so that the extraction electrode of the crystal unit 3 is connected to the electrode pad 24.
Then, the crystal oscillator 3 is placed. Then, the conductive resin paste 251 is cured, and the crystal unit 3 is fixed to the ceramic substrate 2. Next, after adjusting the frequency of the quartz oscillator 3, the metal lid 4 is placed in a nitrogen gas or vacuum. At this time, as shown in FIG. 1, the inclined portion 4b of the metal lid 4 is placed so as to press the elastic member 6 from above and from the inner wall surface of the wall 4b of the metal lid 4. . Next, a roller electrode for seam welding is brought into contact with the edge surface of the welded portion 4a of the metal lid 4 in FIG. 3A, and while supplying a predetermined current, the roller electrode is scanned to form a ring member. The plating layer 5b on the surface 5a and the plating layer 42 on the surface of the metal lid 4 are welded. Thus, the metal lid 4 and the ceramic substrate 2 are hermetically sealed.

At this time, the seal ring 5 of the ceramic substrate is used.
The surface of the plating layer 5b formed thereon has irregularities and the metal lid 4
There is a metal burr or warp on the contact surface of the welded portion 4a, and a spark is generated between the joint around the metal cover 4 and the plating layer, and even if metal components are scattered, the metal cover Since the inner wall surface of the wall portion 4b of the fourth member 4 and the elastic member 6 are firmly in contact with each other and are temporarily sealed, it is possible to block metal components from entering the electronic component mounting space 30. As a result, scattering of the metal component is suppressed at least inside the electronic component mounting space 30, there is no foreign matter in the electronic component mounting space 30, and there is no adhesion to the surface of the crystal resonator 3. .

In the above embodiment, the quartz oscillator 3 is arranged inside the electronic component mounting space 30 of the ceramic substrate 2.
In addition, electronic component elements such as surface acoustic wave elements and IC chips may be accommodated. In the above-described embodiment, the connection between the crystal unit 3 and the electrode pad 24 is made by the conductive resin adhesive 2.
Although it is performed by 51, an electronic component element other than the crystal resonator 3 may be used, and the connection method may be flip chip bonding using a bonding wire or a solder bump.

If necessary, the electronic component mounting space 3
Various chip-shaped electronic components constituting a predetermined circuit may be accommodated and arranged inside the electronic component 0 together with the electronic component elements 3 such as a surface acoustic wave element, a piezoelectric vibrator, and an IC chip.

[0026]

As described above, according to the electronic component device of the present invention, since the inner wall surface of the metal lid is brought into contact with the inclined side surface of the ceramic substrate, the mounting space for the electronic component on the ceramic substrate is reduced. It is possible to seal, even if the contact state of both the metal lid and the sealing conductor is not uniform due to burrs or warpage at the welding position of the metal lid, the discharge spark is generated in the gap. It is possible to prevent the melted metal component from entering the electronic component mounting space.

Further, a convex portion having a rectangular parallelepiped cross section is formed in a region of the ceramic substrate inside the sealing conductor, and an inner wall surface of the metal lid is brought into contact with a side surface of the convex portion via an elastic member. Because of this, the contact between the inclined side surface of the ceramic substrate and the inner wall surface of the metal lid can be suppressed by the elastic member, and the sealing performance of the mounting space for the electronic component can be improved.

Further, a convex portion having a rectangular parallelepiped cross section is formed in a region of the ceramic substrate inside the sealing conductor, and an inner wall surface of the metal lid is brought into contact with a side surface of the convex portion via an elastic member. Therefore, even if the mounting space for the electronic component is sealed, even when the contact state of both the metal lid and the sealing conductor is not uniform due to burrs and warpage at the welding position of the metal lid. In addition, it is possible to prevent the discharge spark and the melted metal component from entering the mounting space of the electronic component in the gap. Thereby, the reliability of the electronic component device can be improved, and the characteristics can be maintained and improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a crystal resonator which is an example of an electronic component device of the present invention.

FIG. 2 is a perspective view of a metal lid used for a crystal unit which is an example of the electronic component device of the present invention.

FIGS. 3A and 3B are partial cross-sectional views of a metal lid used for a crystal unit which is an example of the electronic component device of the present invention. FIG. 3A is a diagram illustrating a metal lid used when a sealing portion of a ceramic substrate is a seal ring. (B) is a metal lid used when the sealing portion of the ceramic substrate is a sealing conductor film.

FIG. 4 is a cross-sectional view of a main part of a ceramic substrate used for a crystal unit which is an example of the electronic component device of the present invention.

FIG. 5 is a top view of a ceramic substrate, which is an example of the electronic component device of the present invention, excluding a quartz oscillator.

FIG. 6 is a cross-sectional view of a crystal resonator according to another embodiment which is an example of the electronic component device of the present invention.

FIG. 7 is a cross-sectional view of a crystal resonator according to another embodiment which is an example of the electronic component device of the present invention.

FIG. 8 is a cross-sectional view of a crystal unit as an example of a conventional electronic component device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Crystal oscillator 2 ... Ceramic substrate 3 ... Crystal oscillator 4 ... Metal lid 4a ... Welded part 4b ... Wall part 4c ... Top part 5 ... Seal ring 5a ..Ring member 5b..Sealing conductor film (sealing conductor) 6 ... Elastic member 20a.

Claims (3)

[Claims] 1. A frame-shaped sealing conductor is attached to an outer peripheral portion of an upper surface of a ceramic substrate on which an electronic component element is mounted, and a space for mounting the electronic component is sealed by the sealing conductor. An electronic component device formed by welding a metal lid, wherein a convex portion having a trapezoidal cross section is formed in a region of the ceramic substrate inside a sealing conductor, and the inclined side surface of the convex portion includes An electronic component device wherein an inner wall surface of a metal lid is brought into contact. 2. The electronic component device according to claim 1, wherein an elastic member is interposed between the inclined side surface of the ceramic substrate and an inner wall surface of the metal lid. 3. A frame-shaped sealing conductor is attached to an outer peripheral portion of an upper surface of a ceramic substrate on which an electronic component element is mounted, and a space for mounting the electronic component is sealed by the sealing conductor. An electronic component device formed by welding a metal lid, wherein a convex portion having a rectangular parallelepiped cross section is formed in a region of the ceramic substrate inside a sealing conductor and an elastic member is provided on a side surface of the convex portion. An electronic component device wherein an inner wall surface of the metal lid is brought into contact.