JP2010199600A - Sealing material and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem in a technique for sealing an electronic component protective package and a sealing material in which a volatile component of binder residue and incorporated component, such as an additive to a plating film, after paste melting and coagulation are discharged during heating and melting when sealing, and in a crystal oscillator, oscillator characteristics are negatively affected as a result of the discharged materials being deposited thereon and the like. <P>SOLUTION: A sealing material is obtained by forming a bonding layer composed of a Cu layer, a Cu alloy layer, or an Au layer with a thickness of 0.05 μm on both surfaces or one surface to serve as a sealing surface of a substrate having a low expansion coefficient, such as Kovar or 42 alloy; forming a sealing layer composed of Au plates and Sn plates alternately stacked in numerous layers by cladding on the bonding layer surface; applying heat treatment at a temperature of 280 to 340°C in a non-oxidizing atmosphere; and adjusting the Au-Sn sealing layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sealing material for sealing, such as an electronic component protection package, and a method for manufacturing the same.

  Conventionally, crystal oscillation elements and SAW filter elements used in electronic devices are enclosed in a ceramic package 101, which is an electronic component protection package, as shown in FIGS. An alloy plate such as a Kovar material or a 42 alloy material having a low expansion coefficient is used as the sealing material 104, and an Au—Sn alloy is frequently used as the sealing material 103.

Substrates such as Kovar material and 42 alloy material, which are sealing materials, are processed into a predetermined shape piece, Ni-plated, and Au-plated to form a sealing material, and Au-Sn as a sealing material The alloy plate piece is inserted between the sealing material for sealing the electronic component protection package, and is heated and melted for sealing (for example, see Patent Document 1).
Further, the Ni-plating and Au-plating processes are applied to the Au-Sn portion as the sealing material, and the multi-layer plating process including Au plating and Sn plating is performed so that the sealing surface of the sealing material has a predetermined Au-Sn composition. The sealing material constituted by the above is heated and melted and sealed on the electronic component protection package (see, for example, Patent Document 2).
JP 2000-31313 A JP 2002-9186 A

However, in the above-mentioned sealing technology between the conventional ceramic package and the sealing material, the volatile component of the binder residue after paste melting and solidification and the incorporation component such as the additive to the plating film are not heated during sealing. In the case of a crystal oscillation element, it is emitted upon melting, and there is a problem of adversely affecting element characteristics due to adhesion of the released substance.
Therefore, in order to reduce the influence at the time of sealing the volatile component, a substrate having a low expansion coefficient such as Kovar material, 42 alloy material, etc. is subjected to Ni plating processing, and Au-Sn on the surface subjected to Au plating processing. After the alloy paste is applied, it must be melted at a higher temperature than necessary to volatilize its volatile components, resulting in excessive diffusion and a problem that sufficient sealing strength cannot be obtained.

Further, in order to reduce the amount of components incorporated such as additives into the plating film, there is a drawback that a predetermined plating film cannot be formed if no additive is added or the amount of additive is reduced.
The present invention has been made to solve the above-described problems, and seals an electronic component protection package such as a ceramic package with a sealing material having a low expansion coefficient such as a Kovar material or a 42 alloy material. An object of the present invention is to provide a sealing material capable of avoiding the influence of the sealing material that is sealed via the element when the element characteristics are easily affected by the sealing atmosphere as in a crystal oscillation element. .

  The present invention relates to a sealing material for sealing an electronic component protection package such as a ceramic package through a sealing material with a sealing material having a low expansion coefficient such as a Kovar material or a 42 alloy material. The thickness of the substrate having a low expansion coefficient, such as a surface that is wettable with respect to the Au plate and the Sn plate, which are sealing materials, and sufficient bonding strength is obtained. A sealing layer in which a Cu layer of 20 to 20 μm, a Cu alloy layer or an Au layer is formed, and an Au plate and an Sn plate are alternately laminated in multiple stages as a sealing material is formed by cladding, and further in a non-oxidizing atmosphere 280 By applying a heat treatment at a temperature of ˜340 ° C. to prepare a sealing material in which a 75 to 85 wt% Au—Sn layer is adjusted, the element characteristics are affected by the sealing atmosphere like a crystal oscillation element. When it was easy, the sealing material was able to avoid the influence. The heat treatment may be a treatment in a vacuum.

The layer in which the Au layer and the Sn layer are laminated in multiple stages so as to have a 75 to 85 wt% Au—Sn alloy composition may be based on multilayer plating with an Au—Sn composition.
In the above configuration, the Au—Sn composition is 75 to 85 wt% because if it is less than 75 wt%, it becomes brittle and hinders the sealing process, and if it exceeds 85 wt%, the sealing temperature rises, This is because it has an adverse effect.

The reason why the thickness of the Cu layer, the Cu alloy layer, or the Au layer is set to 0.02 to 20 μm is that if the thickness is less than 0.02 μm, there is no effect, and if it exceeds 20 μm, the sealing process is adversely affected. . Ideally, about 2 μm is preferable.
Moreover, when forming Cu layer, Cu alloy layer, or Au layer, a clad process or a plating process may be sufficient.

Furthermore, when a layer made of a Cu alloy is formed, the Cu component composition is preferably 70 wt% or more. This is because if it is less than 70 wt%, a brittle layer similar to the Ni layer is likely to be generated.
Furthermore, in order to obtain further melting and spreading of the Au—Sn part, an Au layer may be formed on the Cu layer or the Cu alloy layer.
The heat treatment temperature for adjusting the Au—Sn layer is set to 280 to 340 ° C. The effect cannot be obtained when the temperature is less than 280 ° C. When the temperature exceeds 340 ° C., the sealing strength at the time of sealing is lowered. Because.

  Furthermore, the adjustment of the Au—Sn layer by heat treatment in a non-oxidizing atmosphere may be performed by heat-treating the composite strip material according to the present invention, and thereafter, a composite encapsulating material piece may be formed by press punching.

  Thus, the sealing layer which consists of 75-85 wt% Au-Sn layer as a sealing material is comprised by the clad process to the single side | surface used as a sealing surface, and also in the non-oxidizing atmosphere at the temperature of 280-340 degreeC. By using a sealing material in which the Au—Sn layer is adjusted by heat treatment, there is an effect that the influence can be avoided when the element characteristics are easily influenced by the sealing atmosphere like a crystal oscillation element. .

Embodiments of the present invention will be described below with reference to the drawings.
Example 1 A strip 6 having a thickness of 1 mm and a width of 20 mm made of Au and a strip 7 having a width of 1 mm and a width of 20 mm made of Sn are used in the thickness direction. / Sn / Au / Sn / Au in composite order by clad processing, and the composition after melting is 80 wt% Au—Sn alloy, and the cross-sectional shape in the width direction is 0.012 mm thick and 20 mm wide sealing material 4 (Fig. 1).

A bonding layer 2 made of Au having a plating layer thickness of 0.05 μm is formed by Au plating on a substrate 1 having a cross-sectional shape in the width direction of 0.12 mm and a width of 20 mm made of Kovar material (the case of both surfaces is shown). 1 composite material 3 (FIG. 2), subjected to heat treatment at 200 ° C., and the sealing material 4 is clad on the surface of the bonding layer 2 at a processing speed of 2 m / min and a temperature of 230 ° C. A second composite material 5 having a cross-sectional shape in the width direction of 0.1 mm and a width of 20 mm is formed (FIG. 3), and a 3 mm square composite sealing material e having a thickness of 0.1 mm is formed by press-cutting. Obtained.
The composite sealing member e was heat-treated in a non-oxidizing atmosphere at a temperature of 290 ° C. to obtain a composite sealing material piece E with an adjusted Au—Sn layer.

Second Example The Kovar material of the substrate 1 of the first example was changed to 42 alloy material, and a 3 mm square composite sealing material f having a thickness of 0.1 mm was obtained in the same manner as described above.
The composite sealing member f was heat-treated in a non-oxidizing atmosphere at a temperature of 290 ° C. to obtain a composite sealing material piece F in which the Au—Sn layer was adjusted.

Third Example The Au layer of the bonding layer 2 of the first example was replaced with a Cu layer, and a 3 mm square composite sealing material g having a plate thickness of 0.1 mm was obtained in the same manner as described above.
The composite sealing member g was heat treated at a temperature of 290 ° C. in a non-oxidizing atmosphere to obtain a composite sealing material piece G in which the Au—Sn layer was adjusted.

Fourth Example The Au layer of the bonding layer 2 of the first example is replaced with a 70 wt% Cu—Ni alloy layer, and a 3 mm square composite sealing material h having a plate thickness of 0.1 mm is obtained by the same method as described above. It was.
The composite sealing member h was subjected to heat treatment at a temperature of 290 ° C. in a non-oxidizing atmosphere to obtain a composite sealing material piece H in which the Au—Sn layer was adjusted.

Comparative Example 1
A strip material having a cross-sectional shape in the width direction made of Kovar material having a plate thickness of 0.07 mm and a width of 20 mm is obtained by press-cutting to obtain a 3 mm square substrate piece, and a Ni layer having a thickness of 0.01 mm made of Ni is plated. An Au layer having a thickness of 0.001 mm made of Au was provided on the entire surface by plating, and a 3 mm square composite piece having a thickness of 0.092 mm was obtained.
Next, a paste material made of 80 wt% Au—Sn alloy was applied onto the composite piece and then fused to obtain a 3 mm square composite sealing material I having a plate thickness of 0.1 mm.

Comparative Example 2
The Kovar material of the substrate was changed to 42 alloy material, and a 3 mm square composite sealing material J having a plate thickness of 0.1 mm was obtained by the same method as described above.

Comparative Example 3
A multilayer was formed in the order of Au / Sn / Au / Sn / Au in the thickness direction on one side of the composite piece of Comparative Example 1, and each Sn layer portion was formed by Sn plating to form a layer having a thickness of 0.002 mm. And a composite sealing material K of 3 mm square having a thickness of 0.1 mm and an Au / Sn / Au / Sn / Au portion thickness of 0.01 mm was obtained.

Comparative Example 4
The Kovar material of the said board | substrate was made into 42 alloy material, and the composite sealing material L of 3 mm square which consists of plate | board thickness 0.1mm by the method similar to the above was obtained.
Table 1 shows the results of comparison of the adverse effects on the crystal oscillation element by sealing the composite sealing materials E to H and I to L on the ceramic package of the crystal oscillation element.

Explanatory drawing of an Example Explanatory drawing which shows an Example Explanatory drawing which shows an Example Perspective view of electronic component package Cross-sectional explanatory drawing of electronic component package

1 substrate 2 bonding layer 3 first composite material 4 sealing material 5 second composite material 6 strip material 7 strip material

Claims (2)

In a sealing material for sealing an electronic component protection package via a sealing material with a sealing material having a low expansion coefficient such as Kovar material, 42 alloy material,
A bonding layer made of a Cu layer, a Cu alloy layer or an Au layer having a thickness of 0.05 μm is provided on both surfaces of a substrate having a low expansion coefficient such as Kovar material and 42 alloy material, or a sealing surface. A sealing layer is formed by forming a sealing layer in which Au plates and Sn plates are alternately laminated in multiple stages, and the sealing layer made of Au-Sn is adjusted by heat treatment in a non-oxidizing atmosphere. material. In a manufacturing method of a sealing material, which seals an electronic component protection package via a sealing material with a sealing material having a low expansion coefficient such as Kovar material, 42 alloy material,
A bonding layer made of a Cu layer, a Cu alloy layer, or an Au layer having a thickness of 0.05 μm is formed on both surfaces of a substrate having a low expansion coefficient such as Kovar material and 42 alloy material, or a sealing surface, A sealing layer in which Au plates and Sn plates are alternately laminated in multiple stages is formed on the bonding layer surface by clad processing, and heat treatment is performed at a temperature of 280 to 340 ° C. in a non-oxidizing atmosphere, and the Au—Sn sealing is performed. A method for producing a sealing material, comprising adjusting a deposition layer.

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