JPH0613829A - Piezoelectric element storing package - Google Patents

Abstract

PURPOSE:To stably keep the oscillation frequency of a piezoelectric element with respect to a piezoelectric element storing package. CONSTITUTION:A piezoelectric element storing package 1 consists of an insulated substrate 2, a pair of lead terminals 3 which have the support bars 6 to support a piezoelectric element 11 and the lead parts 5 extending to the outside of the substrate 2 in a single body, and a cover body 4 which can be fixed onto the substrate 2 and also seals airtightly the element 11. The terminals 3 are fixed onto the substrate 2 with use of a glass adhesive 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a housing package, and more particularly to a piezoelectric element housing package for housing a piezoelectric element.

[0002]

2. Description of the Related Art A piezoelectric element housing package for housing a piezoelectric element such as a crystal resonator or a ceramic piezoelectric element is
It is mainly composed of an insulating substrate and a lid. The insulating substrate is a rectangular flat plate made of an electrically insulating material such as alumina ceramics, and has a pair of metallized wiring layers extending from the upper surface to the lower surface via the side surfaces. A holding metal fitting for holding the piezoelectric element is fixed to each metallized wiring layer using a conductive adhesive material such as conductive polyimide.

Such a piezoelectric element housing package is
When the piezoelectric element is fixed between the holding metal fittings fixed to the metallized wiring layer by using a conductive adhesive, and the insulating substrate and the lid are airtightly joined by using a sealing material made of, for example, amorphous glass, The piezoelectric element can be housed in an airtight manner. In the case of joining the insulating substrate and the lid, an amorphous glass layer is previously formed on the joining surfaces of both members. Then, the amorphous glass layers of both members are brought into contact with each other and heated to melt and integrate both amorphous glass layers.

[0004]

In the conventional package for housing a piezoelectric element, since the holding metal fitting and the metallized wiring layer are bonded together by using a conductive adhesive material such as a conductive polyimide resin, the bonding strength between them is high. Is likely to be insufficient. In addition, a conductive adhesive such as a conductive polyimide resin may generate gas due to heat treatment when bonding the insulating substrate and the lid. The gas generated from the conductive adhesive increases the internal pressure of the container including the insulating substrate and the lid, and causes the frequency of the piezoelectric element to fluctuate. Furthermore, since the metallized wiring layer provided on the insulating substrate has poor wettability with the sealing material for joining the insulating substrate and the lid, the airtightness of the joint between the insulating substrate and the lid is improved. It will be an obstacle to increase.

SUMMARY OF THE INVENTION An object of the present invention is to provide a package for housing a piezoelectric element so that the frequency of the piezoelectric element can be stably maintained.

[0006]

A piezoelectric element housing package according to the present invention is for housing a piezoelectric element. This piezoelectric element storage package includes an insulating substrate and
A pair of lead terminals fixed to the insulating substrate with a glass material, having a supporting portion for supporting the piezoelectric element and integrally having a lead portion extending to the outside of the insulating substrate, and the insulating substrate And a lid for hermetically sealing the piezoelectric element.

[0007]

The piezoelectric element housing package according to the present invention can support the piezoelectric element between the supporting portions of the pair of lead terminals fixed to the insulating substrate. The piezoelectric element supported by the insulating substrate is hermetically sealed by joining the insulating substrate and the lid. Here, the glass material fixing the lead terminals to the insulating substrate is unlikely to generate gas during heating. Therefore, the frequency of the piezoelectric element sealed in the package does not easily change.

[0008]

1 and 2 show a package for accommodating a piezoelectric element according to an embodiment of the present invention. In the figure, the piezoelectric element housing package 1 mainly includes an insulating substrate 2, a pair of lead terminals 3 and 3 attached to the insulating substrate 2, and a lid 4. The insulating substrate 2 is a rectangular flat plate made of an electrically insulating material such as alumina ceramics. A glass adhesive 8 for fixing the lead terminals 3 on the insulating substrate 2 is arranged in the central portion of the upper surface of the insulating substrate 2 in the figure. The vitreous adhesive material 8 is arranged in a rectangular shape. The vitreous adhesive 8 is crystallized glass, and for example, 61.0 wt% lead oxide, 9.3 wt% zinc oxide, 9.2 wt% zirconium oxide, 8.4 wt% silica, and 8. Contains 8% by weight.

On the outer peripheral portion of the vitreous adhesive material 8, that is, on the outer peripheral portion of the upper surface of the insulating substrate 2 in the figure, a vitreous sealing material 9 is arranged. The vitreous sealing material 9 is an amorphous glass, and contains, for example, 75% by weight of lead oxide, 9.0% by weight of titanium oxide, 7.5% by weight of boron oxide and 2.0% by weight of zinc oxide. There is. The lead terminal 3 is mainly composed of a lead portion 5 extending in the width direction of the insulating substrate 2, and a supporting piece 6 and a fixing piece 7 provided in the central portion of the lead portion 5. The lead portion 5 is formed by bending at both ends so as to follow the side surface shape of the insulative substrate 2 with a certain distance from the insulative substrate 2, and the tip 5a extends to the lower surface of the insulative substrate 2 in the drawing. The tip 5a is also spaced from the lower surface of the insulating substrate 2 in the figure (FIG. 2). The tip 5a is
It serves as an electrode when the piezoelectric element housing package 1 is mounted on the wiring of the circuit board.

The support piece 6 is for supporting the piezoelectric element, and projects above the lead portion 5. Support piece 6
Is bent into an L shape and can support the piezoelectric element on the horizontal portion 6a. The fixing piece 7 protrudes horizontally from the lead portion 5 and serves to secure a bonding area between the lead terminal 3 and the insulating substrate 2. The above-mentioned lead terminal 3 is made of metal such as Kovar or 42 alloy. By adopting a well-known metal processing method, the lead portion 5 and the support piece 6 are formed.
Also, the fixing piece 7 is integrally formed. Further, the lead terminal 3 has a metal layer (not shown) such as aluminum or silver formed on the surface. This metal layer is for preventing the lead terminal 3 from being oxidized and for enhancing the wetting property with the vitreous adhesive material 8 and the vitreous sealing material 9. The thickness of the metal layer is preferably set to 1.0 to 20.0 μm.

Such a pair of lead terminals 3 and 3 are symmetrically arranged on the insulating substrate 2 with a constant space therebetween, and are fixed on the insulating substrate 2 by the vitreous adhesive material 8. There is. As shown in FIG. 3, the lead portion 5 of the lead terminal 3 crosses the vitreous sealing material 9 so as to be flush with the vitreous sealing material 9. The lid 4 is an insulating substrate 2
It is a box-shaped member that is made of the same ceramics and has an opening on the lower side of the figure. Around the opening, a glass sealing material 10 made of amorphous glass similar to the glass sealing material 9 is arranged.

Next, a method for manufacturing the piezoelectric element housing package 1 will be described. First, the insulating substrate 2 is prepared. When the insulating substrate 2 is made of alumina ceramics, for example, alumina, silica, calcia, magnesia, and other raw material powders are mixed with a suitable binder, an organic solvent, and a solvent to form a slurry, which is then subjected to a doctor blade method or a calendar roll method. It is obtained by forming into a sheet and firing by a known method such as.

Next, as shown in FIG. 4, glass pastes 8a and 9a for forming the vitreous adhesive material 8 and the vitreous sealing material 9 are placed on the obtained insulating substrate 2. These glass pastes 8a and 9a are obtained by adding a suitable binder and solvent to the above-mentioned crystallized glass material or amorphous glass material and mixing them. Glass paste 8
The a and 9a can be arranged on the insulating substrate 2 by adopting a known printing method such as a screen printing method.

Next, the lead terminals 3 whose both ends are not formed by bending as shown in FIG. 4 are arranged on the glass pastes 8a and 9a. Here, the fixing piece 7 of the lead terminal 3 is arranged on the glass paste 8a, and the lead portion 5 is arranged on the glass paste 8a and the glass paste 9a. Then, the lead terminal 3 is pushed into both the glass pastes 8a and 9a by the thickness thereof.

When the glass pastes 8a and 9a are fired in this state, both the glass pastes 8a and 9a are vitrified and become the vitreous adhesive material 8 and the vitreous sealing material 9, respectively. At the same time, the pair of lead terminals 3 and 3 are connected to the insulating substrate 2.
Fixed to. Next, both ends of the lead terminal 3 fixed to the insulating substrate 2 are formed by bending as shown in FIG. As a result, the insulating substrate 2 including the pair of lead terminals 3 and 3 is provided.
Is obtained. It should be noted that, when the lead terminal 3 is bent and formed, microcracks may occur in the vitreous encapsulant 9, but these microcracks disappear when the insulating substrate 2 and the lid 4 are bonded to each other, which will be described later.

Next, the lid 4 is prepared. The lid 4 is obtained, for example, by stacking the same green sheets as described above and firing the laminated green sheets. A glass paste similar to the above-mentioned glass paste 9a is arranged on the periphery of the opening of the lid 4 by a method such as screen printing, and is baked. Next, a method of using the piezoelectric element housing package 1 will be described.

A piezoelectric element 11 is arranged between a pair of lead terminals 3 and 3 attached to the insulating substrate 2 as shown by a chain double-dashed line in FIGS. Here, both ends of the piezoelectric element 11 are placed on the horizontal portion 6a of the support piece 6 and fixed by using a conductive adhesive material such as a conductive polyimide resin. Next, the insulating substrate 2 and the lid 4 are joined together. Here, the glass sealing material 10 of the lid 4 is placed on the glass sealing material 9 of the insulating substrate 2 and heated. As a result, both glass sealing materials 9 and 10 are melted and integrated, and the lid 4 and the insulating substrate 2 are joined.

At the time of such a joining process, since the glass-like sealing materials 9 and 10 are made of an amorphous glass material, they can be joined by a low temperature treatment of about 400.degree. For this reason,
Since the vitreous adhesive material 8 having a high melting temperature is not melted, the lead terminals 3 are not displaced. Further, the above-mentioned microcracks generated in the vitreous sealing material 9 disappear when the vitreous sealing materials 9 and 10 are melted and integrated. Therefore, the airtightness of the bonded portion is maintained well. Furthermore, 1
A vitreous adhesive material 8 for fixing the pair of lead terminals 3, 3.
Does not vaporize, so it is difficult for the internal pressure to increase. Therefore, the frequency of the piezoelectric element 11 is stably maintained.

The semiconductor element housing package 1 housing the piezoelectric element 11 is mounted on the circuit board by the tips 5a of the lead terminals 3.

[0020]

In the package for accommodating the piezoelectric element according to the present invention, the lead terminal having the supporting portion for supporting the piezoelectric element is fixed to the insulating substrate using the glass material, so that the frequency of the piezoelectric element is stabilized. Can be maintained at

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an embodiment of the present invention.

FIG. 2 is a vertical sectional view of the embodiment.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a perspective view showing a step of the manufacturing process of the embodiment.

[Explanation of symbols]

 1 Package for Piezoelectric Element 2 Insulating Substrate 3 Lead Terminal 4 Lid 5 Lead 6 Supporting Piece 8 Glass Adhesive

Claims (1)

[Claims] 1. A piezoelectric element housing package for housing a piezoelectric element, comprising: an insulating substrate; and a supporting portion for supporting the piezoelectric element, and a lead portion extending to the outside of the insulating substrate. A pair of lead terminals fixed to the insulating substrate using a glass material, and a lid body that can be fixed to the insulating substrate and that hermetically seals the piezoelectric element. , A package for storing a piezoelectric element.