JP2006059874A - Manufacturing method for sealing lid and welding jig - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the manufacturing method of a sealing lid with which remainder of air bubbles on the surface of a wax material is reduced, and dispersion of height of the wax material can be reduced; and to provide a welding jig. <P>SOLUTION: A cap (3) and a window frame-like wax material (4) are welded by a reflow furnace and the sealing lid is manufactured by using the welding jig formed of an upper mold (1) and a lower mold (2). A groove (5) storing the wax material (4) is formed in the upper mold and a dented release groove (5a) in the groove (5). The cap (3) is stored in a space formed between the upper mold (1) storing the wax material (4) in the groove (5) and the lower mold (2) combined opposite the upper mold (1). The wax material (4) is welded to the cap (3) in a state where the upper mold (1) storing the wax material (4) and the cap (3) is positioned on the lower mold (2). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a manufacturing method and a welding jig for a sealing lid in which a cap and a brazing material are bonded in advance, and in particular, a manufacturing method and a welding for obtaining a sealing lid with good moldability of the brazing material and less bubbles. It relates to a jig.

  In a high-frequency device such as a SAW filter or a crystal resonator, the package is hermetically sealed, and the package is made of Kovar, ceramic, resin, or the like. As the sealing form, brazing, seam welding, Either spot welding or resin sealing is commonly used. Among the sealing forms, in order to perform brazing, a sealing lid, which is a welded product obtained by welding a brazing material to a cap (CAP) in advance, or a brazing material is previously attached to the cap by thermocompression bonding. A method of attaching the sealing lid to the stem using a sealing lid is used. The cap is used by applying Au plating to Kovar with Ni plating, and Au / 20 mass% Sn is often used for the brazing material.

  The sealing lid, which is the aforementioned welded product, is manufactured by placing a brazing material and a cap on a welding jig and reflowing it in a belt furnace. There are two ways.

  As a first mounting method, there is a method in which a cap and a brazing material are arranged on a welding jig having a groove into which a brazing material and a cap are inserted so that the cap is placed on the brazing material and reflowed. In this case, it is possible to manufacture a welded product with good moldability of the brazing material. However, since the gap between the cap and the brazing material remains as bubbles during welding, and a plurality of bubbles may be bonded, there is a risk of being involved in leakage after hermetically sealing the package or impairing the bonding strength.

  As a second mounting method, there is a method in which a cap and a brazing material are arranged so that the brazing material is placed on the cap and reflowed. In this case, the residual bubbles can be reduced. However, when the brazing material has a rectangular window frame shape, the melted solder tends to gather inside the corner due to surface tension, and the brazing material on the side melts and is pulled by the corner. There is a risk that the height of the portion may vary, and when the package is hermetically sealed, an excess portion and a lack portion of the brazing material are generated, and the reliability of the package may be impaired in terms of sealing performance and bonding strength. there were.

  In a method for manufacturing a surface acoustic wave device (Japanese Patent Laid-Open No. 9-153964), a sealing lid which is a welded product is obtained by placing a brazing material on a flat welding jig and placing a cap thereon and reflowing. Describes a method for making the height of the brazing material uniform. However, this method has a problem that it is difficult to eliminate bubbles remaining between the cap and the brazing material.

  As a workaround, if a brazing material is placed on the cap and a flat welding jig is placed on the cap, air bubbles are trapped on the contact surface between the brazing material and the welding jig during welding. There are cases where traces of crater-like bubbles remain on the surface of the later brazing material. In such a case, if a sealing method in which the sealing lid and the stem are stacked and heated is employed, there is a problem that the crater portion on the surface of the brazing material may remain as bubbles.

Japanese Patent Laid-Open No. 9-153764

  An object of the present invention is to produce a sealing lid, which can reduce the residual of bubbles on the surface of the brazing material and reduce the variation in the height of the brazing material when producing the sealing lid, and A welding jig is provided.

  The method for manufacturing a sealing lid of the present invention is to manufacture a sealing lid by welding a cap and a window frame-shaped brazing material in a reflow furnace using a welding jig composed of an upper mold and a lower mold. To do. The upper mold is formed with a groove capable of accommodating the brazing material, and a relief groove further recessed in the groove, and is combined with the upper mold accommodating the brazing material in the groove so as to face the upper mold. The cap is accommodated in a space formed between the lower mold and the upper mold and the lower mold containing the brazing material and the cap, with the upper mold positioned above the lower mold. The brazing material is welded to the cap.

  The upper mold of the welding jig of the present invention is an upper mold of the welding jig used when manufacturing a sealing lid by welding a cap and a window frame-shaped brazing material, And a relief groove that is further recessed in the groove.

  The welding jig of the present invention is used when a cap and a window frame-shaped brazing material are welded to manufacture a sealing lid, and is a welding jig composed of a lower mold and the upper mold. A space in which the cap can be accommodated is formed between the upper mold that accommodates the brazing material in the groove and the lower mold that is combined to face the upper mold.

  The present invention enables hermetic sealing excellent in bondability and bond strength in a high-frequency device package.

  The present invention will be described with reference to the drawings. FIG. 1 is a partially broken perspective view showing a state in which a cap and a brazing material are arranged on a welding jig, and FIG. 2 is a partially broken perspective view showing a state in a reflow furnace. FIG. 3 is a partially broken perspective view showing the upper mold.

  The welding jig of the present invention comprising the upper mold (1) and the lower mold (2) is made of carbon or stainless steel. The upper mold (1) has a groove (5) for positioning the cap (3) and the brazing material (4). That is, in the state in which the brazing material (4) is accommodated in the groove (5), the extended surface of the outer periphery of the groove (5), a part of the upper mold (1) that rises relatively inside the groove (5), and A recess capable of accommodating the cap (3) is formed by the surface of the brazing material (4). The lower die (2) is a flat plate provided on the outer side of the portion facing the groove (5) so that the lower die (2) can be overlapped and fixed with the upper die (1). 3) A shallow groove or ridge for positioning is formed. Further, in the groove (5), a relief groove (5a) that is recessed near the center of the frame width is formed.

  The manufacturing method of the sealing lid of the present invention using the welding jig will be described below.

  The brazing material (4) is accommodated in the groove (5) of the upper die (1), the cap (3) is further accommodated, and the lower die (2) is opposed to the upper die (1) and the lower die. After combining (2), turn over the whole so that the brazing material (4) is located above the cap (3) and the upper die (1) is located above the lower die (2), A welded product is obtained by making a state in which a partially broken perspective view is shown in FIG. 2 and flowing in a reflow furnace (not shown).

  In the reflow furnace, the brazing material (4a) in which the brazing material (4) is melted has a surface-like shape, and the entire surface is shaped like a crumb. The edge part in the groove | channel (5) to perform has the effect of reducing the deviation of the height of a wax (4a). As a result, when there is no escape, the rise of the row (4a) is reduced at the corner where the row (4a) tends to gather, and the height of the row (4a) is formed uniformly.

  When the escape groove (5a) is not provided, when the brazing material (4) is melted, bubbles remain at the contact portion between the brazing (4a) and the upper die (1), and the upper die (1) is brought into contact with the surface. The surface of the solder may be taken into the solder (4a), but by providing the relief groove (5a), the contact between the solder (4a) and the upper mold (1) becomes a point or a line from the surface. In the contact between the wax (4a) and the upper mold (1), it is possible to reduce unevenness and adhesion of the wax (4a).

Example 1
As shown in FIGS. 1 to 3, a cap (3) obtained by applying Ni plating to Kovar on the upper mold (1) and lower mold (2) of high-purity carbon and further performing Au plating, and Au / 20 The brazing material (4) of mass% Sn was accommodated as shown in a partially broken perspective view in FIG. The cross-sectional shape of the brazing material (4) was 0.3 mm × 0.03 mm, and the cross-sectional shape of the escape groove (5a) was 0.2 mm × 0.1 mm. Therefore, the volume of the space appearing in the escape groove (5a) is about 220% with respect to the volume of the brazing material (4).

  Further, as shown in a partially broken perspective view in FIG. 2, the whole is turned over, and a reflow furnace (Koyo Thermo, PILOT-II) is used to introduce a mixed gas of nitrogen and hydrogen into the furnace. The brazing material (4) was welded to the cap (3) in an atmosphere where the oxygen concentration of the steel was 10 ppm or less.

  After the wax solidified, the number of bubbles remaining in the brazing material was measured with a micro X-ray transmission device (Toshiba, TOSMICRON-6125). Table 1 shows the state of bubbles remaining in the brazing material.

  Further, in the obtained welded product, the height of the solidified wax was measured at the center and the corner of the side. The measurement results are shown in Table 2.

(Comparative Example 1)
The brazing material (4) was welded to the cap (3) in the same manner as in Example 1 except that the whole was not turned over and remained in the state shown in FIG. Further, in the same manner as in Example 1, the number of bubbles remaining in the brazing material was measured. Table 1 shows the state of bubbles remaining in the brazing material.

(Conventional example 1)
A brazing material (4) was welded to the cap (3) in the same manner as in Example 1 except that a welding jig without a relief groove (5a) was used. Further, in the same manner as in Example 1, the height of the solidified wax was measured at the center and the corner of the side portion. The measurement results are shown in Table 2.

  In Comparative Example 1 in which the brazing material (4) is disposed below the cap (3) and welded, the brazing material (4) is disposed above the cap (3) and welded. It can be seen that there are few remaining bubbles.

  Further, compared with the conventional example 1 in which the escape groove (5a) is not provided, in the example 1 in which the escape groove (5a) is provided, the solidified solder is obtained by the present invention so that the variation in the height of the solder is small. It can be seen that the effect of suppressing the variation in height was obtained.

It is the partially broken perspective view which showed the state which has arrange | positioned the cap and the brazing material to the welding jig | tool. It is a partially broken perspective view which shows the state in a reflow furnace. It is a partially broken perspective view which shows an upper mold | type.

Explanation of symbols

1 Upper mold 2 Lower mold 3 Cap 4 Brazing material 4a Wax 5 Groove 5a Relief groove

Claims (3)

  A method of manufacturing a sealing lid by welding a cap and a window frame-shaped brazing material in a reflow furnace using a welding jig composed of an upper mold and a lower mold, A groove capable of accommodating the brazing material and a relief groove further recessed in the groove are formed, and between the upper mold in which the brazing material is accommodated in the groove and the lower mold combined in opposition to the upper mold The cap is accommodated in the space formed in the upper mold and the lower mold in which the brazing material and the cap are accommodated, and the brazing material is welded to the cap with the upper mold positioned above the lower mold. A method for producing a sealing lid, characterized by comprising:   An upper mold of a welding jig used when a cap and a window frame-shaped brazing material are welded to produce a sealing lid, and a groove capable of accommodating the brazing material, and further in the groove An upper mold for a welding jig, wherein a recessed relief groove is formed.   A welding jig used when a sealing lid is manufactured by welding a cap and a window frame-shaped brazing material, and comprising a lower mold and an upper mold according to claim 2, wherein the groove A welding jig characterized in that a space capable of accommodating the cap is formed between an upper mold containing a brazing material and a lower mold combined to face the upper mold.

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