JP2003163298A - Sealing cap for electronic element package and its manufacturing method as well as method for sealing using the cap - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing cap for an electronic element package having a low cost, high sealing reliability and a good conveying efficiency, and to provide a method for manufacturing the same and a method for sealing the package. <P>SOLUTION: The sealing cap for the electronic element package comprises a brazing material layer formed on the outer periphery of the one side surface of the cap made of a lithography made of a metal, and a layer containing an Au and an Sn and formed by a plating method on the outer periphery of the one side surface of the cap. The method for manufacturing the cap is provided. The method for sealing the package using the cap is provided. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing cap for use in various electronic device packages, particularly piezoelectric devices, ceramic packages such as surface acoustic waves, a manufacturing method thereof, and a sealing method using the cap.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become smaller and lighter, a large number of surface acoustic wave filters, piezoelectric elements and the like have also been used for filters used in mobile phones and the like. The filter used in this mobile phone is generally manufactured by mounting surface acoustic wave elements, piezoelectric elements, etc. in a cavity formed in a ceramic package and sealing the ceramic package with a metal cap. To be done.
Conventionally, this metal cap is a AuSn for sealing a metal plate.
A material provided with a brazing material such as an alloy or PbSn solder is used. As the shape of the brazing filler metal, there are a brazing filler metal applied to the entire surface and recently a brazing filler metal applied to the outer peripheral portion of the cap. For example, a metal plate having a brazing material adhered to the entire surface by ultrasonic welding, plating, or pressure bonding is punched out of its outer shape with a die to have a desired cap shape. Further, as a method of applying the brazing material to the outer peripheral portion of the cap, a metal plate punched into a desired cap shape in advance with a die is rolled into a thin film, and the brazing material punched into the outer circumferential shape with the die is welded or The method of adhesion is taken.

[0003]

The conventional metal cap having the brazing filler metal applied to the entire surface has a drawback that the cost becomes high because the brazing filler metal is also applied to the unnecessary portion. Especially when using an expensive AuSn alloy, it is fatal industrially. The use of PbSn solder or ultrasonic welding has a drawback that sealing reliability is low. In addition to this, there is a drawback that the brazing material in the unnecessary portion leaks out at the time of sealing and short-circuits the wiring, which lowers the reliability of the element. In order to solve this problem, recently, a method of forming and applying a brazing filler metal only on the outer peripheral portion of the cap, which is a necessary portion, has been attempted. However, it is difficult to automate the punching work after processing because it is a thin piece, and defects such as deformation and misalignment occur. Further, in order to weld the brazing material to the cap, for example, it is necessary to set one cap and one brazing material in each hole of a jig in which a large number of holes are formed in accordance with the outer shape of the cap and heat-weld them. There is a problem that an alignment jig and equipment are required, the process is complicated and the processing cost is increased. In addition, with the miniaturization of packages, it is technically difficult to meet the demand for finer caps. In addition, this cap is packed and arranged in a special case for transportation after it has been aligned, but since it is a minute thin piece, it is necessary to use a lot of shock absorbing material to maintain its quality, The transportation efficiency per hit is poor, and there is a limit on the reuse of the case and cushioning material after use, and a large amount of waste is generated. For example, when a resin stick case is used, one case is filled with 300 to 400 caps in a row, but since this case must be shaped so that one cap can be taken out at the time of use, a special case is used. Since the feeding mechanism and the groove for that purpose are provided, the porosity is high, and the volume is several times the volume of the cap. Further, the gap causes troubles such as movement of the cap during transportation and, in the worst case, reversal. In view of the above-mentioned problems of the prior art, the present invention has a sealing cap that can be manufactured at low cost and has high sealing reliability, and can also reduce transport efficiency and cost at the time of sealing, a manufacturing method thereof, and a sealing cap. A method for sealing an electronic device package using the cap is provided.

[0004]

Means for Solving the Problems The present invention is directed to "1. In a sealing cap for an electronic element package, which comprises a metal lithographic plate and a brazing material layer formed on the outer peripheral portion of one side of the cap, Au is formed on the outer peripheral side of the one side of the cap. A sealing cap for an electronic element package in which a layer containing Sn is formed by plating 2. A layer containing Au and Sn formed by plating is heat-treated and a brazing material layer fused to the outer peripheral portion of one side of the cap. 2. The sealing cap for an electronic device package according to item 1. 3. The layer containing Au and Sn is a layer formed by plating an AuSn alloy, according to any one of items 1 and 2. 3. A sealing cap for an electronic device package, wherein the layer containing Au and Sn is a layer formed by alternately plating Au or AuSn alloy and Sn. The described electronic device package sealing cap. 5. form a braze-forming surface of the cap one side outer peripheral portion in a concave shape downward from the cap surface, this provided a brazing material layer, 1
Item 5. A sealing cap for an electronic device package according to any one of items 1 to 4. 6. The sealing cap for an electronic device package according to any one of items 1 to 5, wherein a large number of caps are aligned and connected in a matrix form via a connecting portion. 7. In a method of manufacturing a sealing cap for an electronic device package, a pattern of a plurality of cap outer peripheral portions arranged in a matrix in a matrix is formed on one surface of a metal lithographic plate by a photolithography method, and Au is formed on the outer peripheral portion of the cap on which the pattern is formed.
After plating a brazing material layer consisting of Sn and Sn, a pattern of the outer shape of the cap and a pattern of a connecting portion for aligning and connecting a plurality of caps in a matrix form are formed by a photoengraving method. Is removed by etching, and a heat treatment is performed at a temperature not lower than the melting point of Sn and not higher than the melting point of Au to fuse the AuSn brazing material to the outer peripheral portion of the cap, and the AuSn brazing material is fused to the outer peripheral portion. A method for manufacturing a sealing cap for an electronic device package, which is characterized in that a large number of them are aligned and connected in a matrix form via the parts. 8. Using the sealing cap for electronic device packages, which is arranged and connected in a matrix form as described in item 6, is sealed while maintaining a state in which a large number of arranged and connected in a matrix form until a sealing step or just before the sealing step. A sealing method using a sealing cap for an electronic device package, which comprises: Regarding

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The feature of the present invention is that a brazing material layer containing Au and Sn is formed on the outer peripheral surface of one side of a cap by a plating method, and heat treatment is applied to the AuSn brazing material on the outer peripheral surface of one side of the cap. Is fused. Since the brazing material is formed only in the originally required part of the outer peripheral part of one side of the cap, and the brazing material is not formed in the unnecessary part, the brazing material cost can be reduced by 0, and the brazing material in the unnecessary part can be sealed. There is no problem of reducing the reliability of the element by short-circuiting the leaking wiring. In addition, since the brazing filler metal is formed by the plating method, it is not necessary to perform microfabrication of the brazing filler metal to an extremely small thickness, and it is not necessary to punch it out and set it on the cap one by one, further reducing the cost. It becomes.

It is efficient and preferable to use the photolithography method for forming the pattern on the outer peripheral portion. The proportion of AuSn is not limited, but it is preferable that Au is contained in an amount of 60 to 85% by weight. If it is 60% or less, the sealing reliability is low, and if it is 85% or more, there are problems of cost and melting point. The layer containing Au and Sn may be formed by plating an AuSn alloy or by alternately plating at least two layers of Au or AuSn alloy and Sn. When the AuSn alloy is formed by plating, there is an advantage that the thermal diffusion due to the heat treatment in the subsequent step can be omitted. When the Au or AuSn alloy and Sn are formed by alternately plating at least two layers or more, the structure is stable. There is an advantage that can be created. Also, if the brazing material forming surface of the outer peripheral portion of one side of the cap is formed in a concave shape below the cap surface, the cap is arranged so as to be fitted into the package at the time of sealing, so that the sealing reliability is dramatically improved. You can

In order to form a concave portion below the cap surface, it may be formed by etching or coining before plating the layer made of Au and Sn, or the outer peripheral portion may be simply formed one step deeper. It may be formed in a groove shape. Although the depth cannot be generally determined depending on the size of the cap and the like, it may be about 10 to 100 μm. In addition, when a large number of caps are aligned and connected in a matrix through the connecting part, they can be processed collectively on the same plane during cap manufacturing, and it is not necessary to handle each cap and brazing material individually, which improves manufacturing efficiency. The manufacturing cost can be reduced. If the groove between the connecting portion and the cap is processed into a V shape by half etching or stamping, the cap can be easily separated after the sealing. Furthermore, when sealing, the packages are arranged at the same pitch as the caps, and a large number of caps aligned and connected in a matrix form are brought into contact with each other through the brazing filler metal surface to allow simultaneous processing at the same time. It is also easy to automate the process such as loading, the sealing process is rationalized, the sealing productivity is significantly improved, the sealing cost can be reduced, and the occurrence of defects due to misalignment can be prevented. In addition, there is no fear of deformation, turning over, or positional displacement during packing or transportation, and the product can be shipped by simply packaging it together without using a special packing case. Therefore, the amount of packing material used is drastically reduced, and the number of parts that can be transported at one time is increased, so that the environmental load can be reduced.

As a method of manufacturing the cap, the outer peripheral portion of the cap, the outer shape of the cap, and the shape of the connecting portion are formed by a photolithography method, and the metal plate is processed into the shape of the cap connecting portion by etching. Is efficient and suitable. For example, by forming a pattern of a cap outer peripheral portion arranged in a matrix in a matrix form on one surface of a metal lithographic plate by a photoengraving method, and plating a layer containing Au and Sn on the patterned outer peripheral portion of the cap, A pattern of the outer shape of the cap and a pattern of a connecting portion for aligning and connecting a plurality of caps in a matrix are formed by a photoengraving method, and portions other than the patterned cap and the connecting portion are removed by etching, and then at a melting point of Sn or less. Au
The heat treatment is performed at a temperature equal to or lower than the melting point of (1) to form a state in which a large number of caps having AuSn brazing material fused to the outer peripheral portion are aligned and connected in a matrix through the connecting portions.
The order of pattern formation, outer shape processing, heat treatment, etc. is not particularly limited and is arbitrary, but the above order is effective and suitable because it can prevent formation of expensive plating on unnecessary parts and is easy to handle. is there. Further, as a condition for carrying out the heat treatment, it is preferable to use a nitrogen gas reducing atmosphere, and it is preferable to press the plating part to close-pack it before the heat treatment so that a more uniform brazing material is formed. . In particular, it is effective when Au or AuSn alloy and Sn are alternately plated in at least two layers. Further, if the undercoating is carried out before the plating, the adhesion of the plating is improved, which is favorable. Au plating having a thickness of about 0.003 to 0.015 μm may be applied on Ni plating having a thickness of about 0.2 to 5.0 μm. The material of the cap is not particularly limited,
42% Ni-Fe alloy or Kovar has a thermal expansion coefficient of S
It is suitable because it is compatible with i and ceramics.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the drawings based on the embodiments. FIG. 1 is a plan view showing a part of a sealing cap for an electronic device package in which a large number of matrix-shaped elements are aligned and connected. In FIG. 1, a brazing material 4 is formed on the outer peripheral portion 6 of the sealing cap 3, and a large number of individual sealing caps 3 are aligned and connected in a matrix via the connecting portions 2. In this example, the pilot holes 10 were formed in the mother sheet 1 with the mother sheet 1 holding a plurality of caps aligned and connected in a matrix. The shape stability of the cap is further improved by holding it on the mother sheet, and by forming the pilot hole, it is possible to perform simultaneous processing using this pilot hole as a reference during sealing processing, etc. It is also easy to automate the process such as using. In addition,
In this embodiment, the cap has a square outer shape,
Of course, the shape is not limited to this, and various shapes such as a rectangle and a circle can be adopted. Further, although the caps are aligned and connected in the shape of the base evenly in the vertical and horizontal directions, the present invention is not limited to this, and it is sufficient that the caps are aligned and connected with regularity, and may be, for example, diagonally connected.

FIG. 2 is an enlarged sectional view of the sealing cap 3 and the connecting portion 2 taken along the line AA 'in FIG. A brazing material 4 is formed on the outer peripheral portion 6 of one side of the metal lithographic plate 7 which is the material of the sealing cap 3, and the brazing material forming surface of the outer peripheral portion 6 is formed in a concave shape below the normal surface of the cap. I understand. Of course, the present invention is not limited to this, but by forming the brazing material forming surface in this way, the cap is placed so as to be fitted into the package at the time of sealing, so that the sealing reliability is dramatically improved. It can be done. Further, the Ni plating 8 as the base plating and the ultra-thin Au plating 9 are formed between the brazing material 4 and the brazing material forming surface, and the adhesion of the brazing material 4 is good. Further, the boundary portion 5 between the sealing cap 3 and the connecting portion 2 is provided with a V-shaped groove, and the cap 3 can be easily separated. It does not need to be V-shaped in particular, as long as the thickness is thin and the strength is lower than that of the ordinary portion.

Next, the manufacturing method will be described more specifically. A photoresist is applied to a 42% Ni-Fe alloy lithographic plate having a thickness of 0.2 mm, a width of 150 mm, and a length of 250 mm, which is a mother sheet, and an outer shape is 2.75 mm square by a photoengraving method.
After exposing the shape pattern of the outer peripheral portion of the cap having a corner R of 0.2 mm and a width of 0.25 mm at a pitch of 4.2 mm in the width direction by 25 pieces and in the length direction by 40 pieces, only the outer peripheral resist film which was developed and removed was removed. The plate thickness is processed thin by half etching, and is formed in a concave shape one step below the normal surface of the cap. Then, dip and degrease in alkaline cleaner at 40 ° C for 30 seconds, wash with water, pickle with 5% Hcl, wash with water, 1.0μ
m Ni and 0.008 μm Au underlayer plating, and then AuS using a commercially available 20% Sn-Au plating solution.
The n-alloy layer was plated and then the photoresist was removed. The thickness of plating was adjusted to 0.035 mm after heat treatment. Next, the entire surface is again coated with photoresist, and by a photoengraving method, a sealing cap having an outer shape of 2.85 mm square has a width of 0.3 mm and a length of 1.35 mm at a connecting portion of 4.2.
Patterning was performed in a state in which 25 pieces were arranged in the width direction and 40 pieces were arranged in the length direction at an mm pitch, and unnecessary portions were removed by an etching method. At the same time, a V-shaped groove and a pilot hole were formed at the boundary between the cap and the connecting portion.
Then, heat treatment is performed at a nitrogen atmosphere peak temperature of 320 ° C., the AuSn brazing material layer is evenly welded to the alloy lithographic plate, and a large number of them are aligned and connected in a matrix form. 0.035 mm AuSn
A sealing cap having a brazing material formed thereon was obtained. In this embodiment, the outer dimensions of the outer peripheral portion where plating is formed are slightly smaller than the outer dimensions of the cap, and the corners are rounded. Of course, the present invention is not limited to this, but the effect of being able to allow the deviation of the pattern formation by forming in this way,
Also, there is an effect that the brazing material can be prevented from protruding from the cap, and the brazing material can be prevented from leaking at the time of sealing. Then, the surface acoustic wave filter package arranged on the carbon jig at the same pitch as that of the above-mentioned embodiment with the mother sheet stacked so that the AuSn brazing material surface is in contact was inverted upside down, and the peak temperature was 320 ° C. A nitrogen atmosphere heat treatment furnace whose temperature was set so as to be continuously passed through the AuSn brazing filler metal was uniformly fused to the surface acoustic wave filter package. The above-mentioned embodiment is a representative example of the present invention,
Comparative example 1 in which an AuSn layer having a thickness of 0.030 mm was pressure-bonded to the entire surface of one side of the cap, and a separately prepared AuSn foil having a thickness of 0.035 mm was set only on the outer peripheral portion of the one side of the cap and then fused. Table 2 shows the results of comparison of the cap manufacturing cost, the sealing defect rate, and the sealing cost.
Shown in. The cost is shown by relative evaluation when the cost in the example is 100.

[0012]

[Table 1]

As is clear from Table 1, this embodiment has a low sealing defect rate of 1/3 to 1/13 of that of the comparative example, and has an excellent sealing effect, while reducing the cap manufacturing cost and sealing cost. Both costs have been significantly reduced. Further, since the sealing cap of the present invention is in a state in which a large number of the sealing caps are aligned and connected in a matrix, it is possible to stack and package the caps. 100 mother sheets were stacked, filled with reinforcing cardboard on the top and bottom, and wrapped with neutral paper. In this one package, 100,000 caps are packed. The size of the package is 200 ×
The size was about 300 x 40 mm, which was about 1/8 the size of the conventional one.

[0014]

The present invention can be applied only to the originally necessary parts.
Since the brazing filler metal is formed by the plating method, there is no problem that the brazing filler metal in the unnecessary portion leaks at the time of sealing. Further, when the brazing material forming surface is formed in a concave shape below the cap surface, the cap is arranged so as to be fitted into the package at the time of sealing, so that the sealing reliability can be dramatically improved. Furthermore, if a large number of caps are aligned and connected in a matrix through the connecting portion, they can be processed collectively on the same plane, and there is no need to handle each cap and brazing material individually.
Automation at the time of sealing becomes easy, and the occurrence of defects can be prevented. Also, when packing or transporting, there is no need to worry about deformation, flipping over, misalignment, or using a special packing case, you can ship by simply packaging in a batch, drastically reducing the amount of packing material used, and you can transport it at once Because the number of parts increases,
It has an extremely excellent effect that the environmental load can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing a sealing cap for an electronic device package, in which a large number of matrix-shaped sealing caps are connected.

FIG. 2 is a cross-sectional view of a sealing cap and a connecting portion.

[Explanation of symbols]

1 mother sheet 2 connection 3 Sealing cap 4 brazing material 5 border 6 outer periphery 7 Metal plate 8 Ni plating 9 Au plating 10 pilot hall

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hitoshi Saito             2220 Daimaru, Inagi-shi, Tokyo Japan Filco             Co., Ltd. Tokyo office (72) Inventor Isamu Saito             2-2-11 Keihinjima, Ota-ku, Tokyo Stocks             Company Todenka (72) Inventor Koji Otake             2-2-11 Keihinjima, Ota-ku, Tokyo Stocks             Company Todenka (72) Inventor Yoshimi Kawakami             2-2-11 Keihinjima, Ota-ku, Tokyo Stocks             Company Todenka

Claims (8)

[Claims] 1. A sealing cap for an electronic device package, comprising a metal lithographic plate and a brazing material layer formed on the outer peripheral surface of one side of the cap, wherein a layer containing Au and Sn is formed on the outer peripheral side of the one surface of the cap by a plating method. Layered sealing cap for electronic device packages. 2. The sealing cap for an electronic element package according to claim 1, wherein a layer containing Au and Sn formed by a plating method is heat-treated to form a brazing material layer fused to the outer peripheral portion of one surface of the cap. . 3. The sealing cap for an electronic device package according to claim 1, wherein the layer containing Au and Sn is a layer formed by plating an AuSn alloy. 4. The layer containing Au and Sn is Au or Au.
The sealing cap for an electronic element package according to claim 1, which is a layer formed by alternately plating Sn alloy and Sn. 5. The electronic element according to claim 1, wherein a brazing material forming surface on the outer peripheral portion of one surface of the cap is formed in a concave shape below the cap surface, and a brazing material layer is provided on the brazing material forming surface. Sealing cap for package. 6. The sealing cap for an electronic device package according to claim 1, wherein a large number of caps are aligned and connected in a matrix form via a connecting portion. 7. A method of manufacturing a sealing cap for an electronic device package, wherein a pattern of a plurality of cap outer peripheral portions arranged in a matrix in a matrix is formed on one surface of a metal lithographic plate by a photomechanical process, and the pattern-formed cap is formed. After plating a brazing material layer made of Au and Sn on the outer peripheral portion, a pattern of the outer shape of the cap and a pattern of a connecting portion for aligning and connecting a plurality of caps in a matrix form are formed by a photolithography method, and the cap having the pattern is formed. And a portion other than the connecting portion is removed by etching, and the melting point of Sn or more is A or more.
A heat treatment at a temperature below the melting point of u
A seal for an electronic element package, characterized in that a plurality of caps, in which uSn brazing material is fused and AuSn brazing material is fused on the outer peripheral portion, are formed in a state of being aligned and connected in a matrix form through a connecting portion. Method for manufacturing stop cap. 8. A state in which a plurality of electronic device package sealing caps arranged and connected in a matrix form according to claim 6 are used in a matrix form until a sealing process or immediately before the sealing process. A sealing method using a sealing cap for an electronic device package, characterized in that the sealing is performed while maintaining the above.