JP3652320B2 - Electronic component storage package and electronic device - Google Patents

Description

【００３４】
表１から分かるように、比較のための試料１、２、６、７、１２には１ヶ月放置後にクラックが発生するものの、本発明の試料３、４、５、８、９、１０ではクラックの発生はなかった。また、比較のための試料１１、１３ではクラックの発生は見られなかったものの、２３０Ａの溶接電流ではろう材が良好に溶融せずにろう材の溶融不足が発生した。
【００３５】
【発明の効果】
以上説明したように、本発明の電子部品収納用パッケージによれば、封止用メタライズ層は、その厚みを４〜８μｍと薄いものとしており、その上に厚みが８〜２０μｍのニッケルめっき層を被着させたことから、封止用メタライズ層の電気抵抗が高いものとなり、封止用メタライズ層に金属蓋体をろう材を介してシーム溶接する際に、溶接の電流は金属蓋体に多く流れるようになるので、その分、溶接電流を小さなものとして封止用メタライズ層が大きく発熱するのを抑制できるとともに封止用メタライズ層と金属蓋体とをろう材を介して良好に溶接することができる。また、溶接の際に封止用メタライズ層や絶縁基体に印加される熱応力を封止用メタライズ層に被着させた厚みが８〜２０μｍのニッケルめっき層により良好に吸収することができ、その結果、封止用メタライズ層や絶縁基体に溶接の際の熱応力によるクラックが発生することを有効に防止することができる。したがって、封止作業の生産性にすぐれ、かつ気密信頼性の高い電子部品収納用パッケージを提供することができる。
【図面の簡単な説明】
【図１】本発明の電子部品収納用パッケージの実施の形態の一例を示す断面図である。
【図２】図１に示す電子部品収納用パッケージの絶縁基体１と金属蓋体２とをろう材８を介してシーム溶接により接合する方法を示す断面図である。
【符号の説明】
１・・・・・絶縁基体
１ａ・・・・搭載部
２・・・・・金属蓋体
３・・・・・電子部品
４・・・・・メタライズ配線導体
６・・・・・封止用メタライズ層
８・・・・・ろう材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic component storage package in which an electronic component such as a piezoelectric vibrator or a semiconductor element is hermetically accommodated in a package composed of an insulating base such as ceramics and a metal lid.
[0002]
[Prior art]
Electronic parts such as piezoelectric vibrators and semiconductor elements are housed and used in an electronic part housing package for hermetically housing these electronic parts.
[0003]
In such an electronic component storage package for storing the electronic components in an airtight manner, the most reliable one is made of ceramics such as an aluminum oxide sintered body, and the mounting portion on which the electronic components are mounted on the upper surface and this An insulating substrate having a frame-shaped sealing metallization layer surrounding the mounting portion and having a plurality of metallized wiring conductors to which electrodes of electronic components are electrically connected on the surface and inside, and a metallization layer for sealing the insulating substrate A metal frame for sealing made of iron-nickel alloy or iron-nickel-cobalt alloy brazed so as to surround the mounting portion, and iron directly joined to the metal frame by seam welding This type is composed of a metal lid made of nickel alloy or iron-nickel-cobalt alloy. In this case, the electronic component is mounted on the mounting portion of the insulating base, and the electrode of the electronic component and the metallized wiring conductor are electrically connected via a solder bump, a bonding wire, etc., and then sealed with the insulating base. A metal lid is placed on a metal frame for stopping, and a pair of roller electrodes of a seam welding machine are brought into contact with the outer peripheral edge of the metal lid and rolled, and a large current for welding is provided between the roller electrodes. By flowing seam and directly seam-welding the metal frame body and the metal lid body, the electronic components are housed in an airtight manner to form an electronic device as a product.
[0004]
However, in this type of electronic component storage package, it is necessary to braze a metal frame for sealing to the metallization layer for sealing as a base metal for seam welding the metal lid to the insulating base, For this reason, the height of the electronic device is increased by the amount of the metal frame, and it has been difficult to reduce the thickness required for a recent electronic device. In addition, there is a problem that the metal frame is expensive.
[0005]
Therefore, in order to solve the above-described problems, the electronic component has an electronic component mounted on the upper surface and a frame-shaped sealing metallization layer surrounding the mounted portion, and the electrode of the electronic component is electrically connected to the surface and the inside. A ceramic insulating base having a plurality of metallized wiring conductors connected to each other and a metal lid having a lower surface coated with a brazing material such as a silver-copper eutectic alloy. Insulation by mounting the electronic component and electrically connecting each electrode of the electronic component to the metallized wiring conductor, and then seam welding the brazing material with the metal lid attached to the lower surface of the sealing metallized layer An electronic component storage package has been proposed in which a base body and a metal lid are joined and an electronic component is hermetically sealed inside.
[0006]
An electronic component storage package in which an electronic component is hermetically accommodated by joining a metal lid to the sealing metallization layer by seam welding via a brazing material such as silver brazing is used for sealing. Since the metallized layer and the metal lid are joined by seam welding via a brazing material, a metal frame as a base metal for welding is not required, and the height can be reduced correspondingly, and it is inexpensive. It is.
[0007]
In the conventional electronic component storage package in which the metal lid having the lower surface coated with the brazing material is joined to the sealing metallization layer of the insulating base through the brazing material by seam welding. The sealing metallized layer had a thickness of 10 μm or more, preferably 20 μm or more, and a nickel plating layer having a thickness of 5 μm or more, preferably 8 μm or more was deposited on the surface thereof. This is because the thickness of the metallizing layer for sealing is increased to 10 μm or more, and a nickel plating layer having a thickness of 5 μm or more is deposited on the surface, so that a metal lid is seamed to the sealing metallized layer via a brazing material. Thermal shock due to the welding current applied to the sealing metallization layer and insulating substrate during welding is absorbed and relaxed by the thick sealing metallization layer and nickel plating layer, and cracks are generated in the sealing metallization layer and insulating substrate. It is based on the idea of preventing it from occurring.
[0008]
[Problems to be solved by the invention]
However, according to the electronic component housing package in which the thickness of the metallization layer for sealing the insulating substrate is 10 μm or more and the nickel plating layer having a thickness of 5 μm or more is deposited thereon as described above, the metallization layer for sealing Because of the large thickness, the electrical resistance of the metallizing layer for sealing becomes low, and therefore, a metal lid with a brazing material applied to the lower surface is seam welded to the metalizing layer for sealing the insulating substrate via the brazing material. When joining, a large amount of current for welding flows through the metallization layer for sealing having a low electrical resistance, and the current flowing through the metal lid is reduced. Therefore, in order to melt the brazing material applied to the metal lid satisfactorily with the welding current, an extremely large welding current must be applied, and a lot of extra power is consumed, so that the sealing productivity is high. In addition to being bad, the thermal stress due to such welding current also increases, so if the insulating substrate is thin, cracks occur in the metallization layer for sealing and the insulating substrate due to the stress remaining between the insulating substrate and the lid after welding. It had the problem that it was easy to end up.
[0009]
As a result of various studies in view of such problems, the present inventor has been designed to accommodate an electronic component in which the metal lid is joined to the metallization layer for sealing the insulating base by seam welding as described above. In the package, the metal lid can be heated effectively by flowing a large amount of welding current through the metal lid assuming that the metallization layer for sealing has a high electric resistance, and hermetic sealing can be performed with a lower welding current. In addition, by applying a nickel plating layer with a thickness equal to or greater than the thickness of the sealing metallization layer, the current flowing through the sealing metallization layer itself is reduced, and heat generation of the sealing metallization layer itself is suppressed and welding is performed. As the thermal stress generated during the process is effectively relieved by the thick nickel plating layer, it is difficult to crack the sealing metallization layer and insulating substrate after welding. It was.
[0010]
The present invention has been devised based on such knowledge, and its purpose is to achieve a lower welding current when a metal lid is joined to a metallization layer for sealing an insulating substrate through a brazing material by seam welding. An object of the present invention is to provide a highly reliable electronic component storage package that can be hermetically sealed and does not cause cracks in the metallization layer for sealing or the insulating substrate.
[0011]
[Means for Solving the Problems]
The electronic component storage package of the present invention includes an insulating base having a mounting portion on which an electronic component is mounted on an upper surface and a sealing metallization layer deposited so as to surround the mounting portion. In the electronic component housing package in which the deposited metal lid is bonded to the sealing metallization layer via the brazing material, the sealing metallization layer has a thickness of 4 to 8 μm, and The nickel plating layer whose thickness is more than the thickness of the metallizing layer for sealing is deposited on the surface. In the electronic component storage package according to the present invention, the insulating base is formed with a rounded portion having a radius of 5 to 50 μm from the upper surface to the outer side surface, and the sealing metallized layer is provided in the middle of the rounded portion. It is characterized by extending so as to become gradually thinner. In the electronic component storage package of the present invention, the sealing metallized layer is formed using a metal paste containing a metal powder having an average particle size of 1 μm or less. . The electronic device according to the present invention also includes an electronic component storage package according to the present invention, an electronic component mounted on the electronic component storage package, and a metal lid bonded to the sealing metallization layer via a brazing material. It is characterized by having a body.
[0012]
According to the electronic component storage package of the present invention, the sealing metallized layer has a thickness as thin as 4 to 8 μm, and a nickel plating layer with a thickness of 8 to 20 μm is deposited thereon. Since the electric resistance of the metallization layer for sealing becomes high, and when the seam welding is performed on the metallized layer for sealing via the brazing material, a large amount of welding current flows to the metal lid, Accordingly, it is possible to suppress the heat generation of the sealing metallization layer with a small welding current, and to favorably weld the sealing metallization layer and the metal lid through the brazing material. Further, the thermal stress applied to the sealing metallization layer and the insulating base during welding can be satisfactorily absorbed by the nickel plating layer having a thickness of 8 to 20 μm applied to the sealing metallization layer. As a result, it is possible to effectively prevent the occurrence of cracks due to thermal stress during welding in the metallizing layer for sealing and the insulating substrate.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Next, an electronic component storage package according to the present invention will be described with reference to the accompanying drawings.
[0014]
FIG. 1 is a cross-sectional view showing an example of an embodiment of an electronic component storage package according to the present invention, in which 1 is an insulating base, 2 is a metal lid, and 3 is an electronic component. Then, an electronic component 3 such as a piezoelectric vibrator or a semiconductor element is hermetically sealed inside a package composed of the insulating base 1 and the metal lid 2 to provide an electronic device as a product.
[0015]
The insulating base 1 is a support for supporting the electronic component 3 and is made of ceramics such as an aluminum oxide sintered body or an aluminum nitride sintered body, and is used for housing the electronic component 3 in the center of the upper surface thereof. A recess A is provided. The bottom surface of the recess A forms a mounting portion 1a for mounting the electronic component 3, and the electronic component 3 is mounted on the mounting portion 1a.
[0016]
If the insulating substrate 1 is made of, for example, an aluminum oxide sintered body, an appropriate organic binder and solvent are added to and mixed with ceramic raw material powder such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, etc. This is made into a ceramic green sheet by adopting a conventionally known doctor blade method or calender roll method, and after that, the ceramic green sheet is appropriately punched and laminated in a plurality of layers at a high temperature. Manufactured by firing.
[0017]
Further, a metallized wiring layer 4 made of a metal powder sintered body such as tungsten or molybdenum derived from the upper surface of the mounting portion 1a to the lower surface of the insulating substrate 1 is deposited on the insulating substrate 1.
[0018]
The metallized wiring layer 4 functions as a conductive path for electrically leading each electrode of the electronic component 3 to the outside, and normally, a nickel plating layer having a thickness of about 1 to 20 μm and 0 And a gold plating layer having a thickness of about 1 to 3 μm. And the electrode of the electronic component 3 is electrically connected to, for example, the conductive adhesive 5 at a portion led out to the upper surface of the mounting portion 1a, and the portion led out to the bottom surface of the insulating base 1 is an external electric circuit It is electrically connected to the wiring conductor of the substrate via, for example, solder.
[0019]
If the metallized wiring layer 4 is made of, for example, a tungsten powder sintered body, a tungsten paste obtained by adding and mixing an appropriate organic binder and solvent to the tungsten powder is conventionally used as a ceramic green sheet for the insulating substrate 1. A predetermined pattern is printed and applied by a well-known screen printing method, and this is baked together with the ceramic green sheet for the insulating substrate 1 to form a predetermined pattern from the upper surface to the lower surface of the mounting portion 1a of the insulating substrate 1.
[0020]
Further, on the outer peripheral portion of the upper surface of the insulating substrate 1, a frame-shaped sealing metallization layer 6 made of a metal powder sintered body such as tungsten or molybdenum and having a width of about 0.4 mm and a thickness of 4 to 8 μm is mounted. It is formed so as to surround 1a.
[0021]
The sealing metallization layer 6 functions as a base metal for bonding the metal lid 2 to the insulating substrate 1, and has a nickel plating layer with a thickness of about 8 to 20 μm and a thickness of about 0.1 to 3 μm on the exposed surface. And a gold plating layer having a thickness of. And the metal cover body 2 is joined on it by the seam welding through the brazing material 8. FIG.
[0022]
If the metallizing layer 6 for sealing is made of, for example, a tungsten powder sintered body, a tungsten paste obtained by adding and mixing an appropriate organic binder and solvent to the tungsten powder is a ceramic green sheet for the insulating substrate 1. In this case, a screen printing method known in the prior art is used, and a predetermined thickness and pattern are preliminarily printed and applied, and this is fired together with a ceramic green sheet for the insulating substrate 1 so as to surround the mounting portion 1a on the upper surface of the insulating substrate 1. Is formed.
[0023]
On the other hand, the metal lid 2 is a flat plate made of an iron-nickel alloy plate or an iron-nickel-cobalt alloy plate and having a thickness of about 0.1 mm. The material 8 is applied to a thickness of about 10 to 20 μm. Then, as shown in a sectional view in FIG. 2, the metal lid 2 is placed on the sealing metallization layer 6 with the brazing material 8 sandwiched between them, and seam welders are placed on the opposing outer peripheral edges of the metal lid 2. The insulating substrate 1 is sealed by rolling while bringing the pair of roller electrodes R into contact with each other, passing a current for welding between the roller electrodes R, and melting a part of the brazing material 8 by heat generated by the current. The electronic component 3 is hermetically sealed with the insulating base 1 by being bonded to the metallization layer 6 for soldering via the brazing material 8.
[0024]
Such a metal lid 2 is formed by rolling an iron-nickel alloy plate or an iron-nickel-cobalt alloy plate with a brazing material foil such as silver-copper brazing on the lower surface of the iron-nickel alloy plate or iron-nickel-cobalt alloy plate. -A composite metal plate having a large area in which a brazing material is pressure-bonded to the lower surface of the cobalt alloy plate is obtained, and the composite metal plate is punched into a predetermined shape by a punching die.
[0025]
And in the electronic component storage package of this invention, while making the thickness of the metallizing layer 6 for sealing as thin as 4-8 micrometers, the nickel plating layer deposited on the surface of this metallizing layer 6 for sealing The thickness is 8 to 20 μm, which is important. The sealing metallization layer 6 is formed with a thickness of 4 to 8 μm, and a nickel plating layer having a thickness of 8 to 20 μm is deposited thereon, so that the nickel plating layer is deposited thereon. As a result, when the metal lid 2 is welded to the sealing metallization layer 6 through the brazing material 8 by seam welding, a large current is applied to the metal lid 2 side. Therefore, the welding current can be reduced by that amount to prevent the sealing metallization layer 6 from generating a large amount of heat, and the brazing material 8 deposited on the metal lid 2 can be melted well by the welding current and sealed. The metallized layer 6 and the metal lid 2 can be bonded well.
[0026]
If the thickness of the sealing metallization layer 6 is less than 4 μm, it tends to be difficult to firmly adhere the sealing metallization layer 6 to the insulating substrate 1. When the metallization layer 6 has a low electrical resistance and the metal lid 2 is welded to the sealing metallization layer 6 via the brazing material 8 by seam welding, the current flowing to the metal lid 2 side is small. Therefore, with a small welding current, it tends to be difficult to melt the brazing material 8 attached to the metal lid 2 well. Therefore, the thickness of the metallizing layer 6 for sealing is specified in the range of 4 to 8 μm.
[0027]
Further, a roundness having a radius of about 5 to 50 μm is formed from the upper surface of the insulating substrate 1 to the outer peripheral side surface, and the outer peripheral edge of the sealing metallization layer 6 is extended so as to be gradually thinned to the middle of the rounded portion. Accordingly, it is possible to effectively prevent the sealing metallization layer 6 from being peeled off from the insulating substrate 1. Accordingly, a roundness having a radius of about 5 to 50 μm is formed from the upper surface to the outer peripheral side surface of the insulating substrate 1, and the outer peripheral edge of the sealing metallization layer 6 is extended so as to become gradually thinner to the middle of the rounded portion. It is preferable to keep it.
[0028]
Moreover, the metal paste for forming the metallizing layer 6 for sealing insulates the metallizing layer 6 having a thin thickness of 4 to 8 μm when the average particle diameter of the metal powder contained therein is 1 μm or less. The upper surface of the substrate 1 can be densely and firmly attached. Accordingly, the metal paste for the metallizing layer 6 for sealing preferably has an average particle size of the metal powder contained therein of 1 μm or less.
[0029]
According to the electronic component storage package of the present invention, since the thickness of the nickel plating layer deposited on the surface of the sealing metallization layer 6 is set to 8 to 20 μm, the metal lid for the sealing metallization layer 6 is covered with a metal lid. When the body 2 is welded through the brazing material 8 by seam welding, a nickel plating layer in which the thermal stress applied to the sealing metallization layer 6 or the insulating base 1 is applied to the sealing metallization layer 6 is good. As a result, when the metal lid 2 is welded to the sealing metallized layer 6 through the brazing material 8 by seam welding, and after the welding, the metallized layer 6 and the insulating substrate 1 are sealed. The occurrence of cracks can be effectively prevented. When the nickel plating layer deposited on the sealing metallization layer 6 is less than 8 μm, the metal lid 2 is welded to the sealing metallization layer 6 via the brazing material 8 by seam welding. In addition, there is a greater risk that the thermal stress applied to the sealing metallization layer 6 and the insulating substrate 1 cannot be satisfactorily absorbed and relaxed. On the other hand, if the thickness exceeds 20 μm, the nickel plating layer having such a large thickness There is a tendency that cracks and peeling are likely to occur in the sealing metallized layer 6 due to the stress generated when the film is applied. Therefore, the thickness of the nickel plating layer applied to the sealing metallization layer 6 is specified in the range of 8 to 20 μm.
[0030]
Thus, according to the electronic component storage package of the present invention, the electronic component 3 is mounted on the mounting portion 1 a of the insulating base 1, and the metal lid 2 is seam welded to the sealing metallized layer 6 via the brazing material 8. By joining together, it is possible to provide a highly reliable electronic component storage package that does not cause disconnection in the metallized wiring conductor 4 or cracks in the insulating substrate 1.
[0031]
In addition, this invention is not limited to an example of the above-mentioned embodiment, and it cannot be overemphasized that a various change is possible if it is a range which does not deviate from the summary of this invention.
[0032]
[Experimental example]
In the center of the upper surface, a rectangular recess having a width of 2.20 mm, a length of 4.00 mm, and a depth of 0.30 mm, a width of 3.20 mm, a length of 5.00 mm, and a thickness of 0.55 mm A rectangular frame-shaped metallization layer for sealing made of tungsten metallization having a width of 0.50 mm that surrounds the recess and extends to the outer peripheral edge is formed on the outer peripheral part of the upper surface of the insulating base made of square box-shaped alumina ceramics with a thickness of 1 to 11 μm. In addition to depositing to a thickness, a nickel plating layer having a thickness of 5 to 23 μm and a gold plating layer having a thickness of 0.3 μm were deposited on the metallizing layer for sealing, thereby obtaining 10 samples for each experiment. It was. Also, a brazing material made of an iron-nickel-cobalt alloy having a width of 2.90 mm, a length of 4.70 mm, and a thickness of 0.10 mm, and a silver-copper eutectic alloy having a thickness of 15 μm is deposited on the lower surface thereof. A metal lid was prepared. Next, a metal lid is placed on the metallization layer for sealing of each sample with the brazing material facing down, and a pair of roller electrodes of the seam welding apparatus is placed between the outer peripheral edges of the metal lid facing each other from above. A welding current of 230 A was applied between the roller electrodes while contacted while applying a load of 200 g and moved at a speed of 10 mm / sec to seam weld the metallized layer for sealing and the metal frame through a brazing material. . Next, after each sample to which the metal lid was welded was allowed to stand at room temperature for one month, each sample was observed with a microscope to check for the presence of cracks in the sealing metallized layer and the insulating substrate. The results are shown in Table 1. Note that samples Nos. 1, 2, 6, 7, 11, 12, and 13 in Table 1 are samples for comparison outside the scope of the present invention.
[0033]
[Table 1]

[0034]
As can be seen from Table 1, the samples 1, 2, 6, 7, and 12 for comparison generate cracks after being left for one month, but the samples 3, 4, 5, 8, 9, and 10 of the present invention have cracks. There was no outbreak. Further, although no cracks were observed in the samples 11 and 13 for comparison, the brazing material did not melt well at the welding current of 230 A, and the brazing material was insufficiently melted.
[0035]
【The invention's effect】
As described above, according to the electronic component storage package of the present invention, the sealing metallization layer has a thickness of 4 to 8 μm, and a nickel plating layer with a thickness of 8 to 20 μm is formed thereon. Since the metallization layer for sealing has a high electric resistance because it is deposited, a large amount of welding current is applied to the metal lid when seam welding the metal lid to the metallization layer for sealing via a brazing material. Therefore, it is possible to suppress the heat generation of the sealing metallization layer greatly by reducing the welding current, and to weld the sealing metallization layer and the metal lid well through the brazing material. Can do. Further, the thermal stress applied to the sealing metallization layer and the insulating base during welding can be satisfactorily absorbed by the nickel plating layer having a thickness of 8 to 20 μm applied to the sealing metallization layer. As a result, it is possible to effectively prevent the occurrence of cracks due to thermal stress during welding in the metallizing layer for sealing and the insulating substrate. Therefore, it is possible to provide an electronic component storage package that is excellent in the productivity of sealing work and has high airtight reliability.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an embodiment of an electronic component storage package according to the present invention.
2 is a cross-sectional view showing a method of joining the insulating base 1 and the metal lid 2 of the electronic component storage package shown in FIG. 1 through a brazing material 8 by seam welding.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Insulation base | substrate 1a ... Mounting part 2 ... Metal lid 3 ... Electronic component 4 ... Metallized wiring conductor 6 ... For sealing Metallized layer 8: brazing material

Claims (4)

A metal lid having a mounting portion on which an electronic component is mounted on an upper surface and an insulating base having a sealing metallization layer deposited so as to surround the mounting portion, and having a brazing material deposited on the lower surface, In the electronic component housing package bonded to the sealing metallization layer via the brazing material, the sealing metallization layer has a thickness of 4 to 8 μm and the thickness of the sealing metallization layer on the surface thereof. A package for storing electronic parts, wherein a nickel plating layer having a thickness equal to or greater than the thickness of the layer is applied.   The insulating base is formed with a rounded portion having a radius of 5 to 50 μm from the upper surface to the outer side surface, and the sealing metallized layer extends so as to become gradually thinner to the middle of the rounded portion. The electronic component storage package according to claim 1, wherein:   3. The electronic component storage package according to claim 1, wherein the sealing metallized layer is formed using a metal paste containing a metal powder having an average particle diameter of 1 [mu] m or less.   The electronic component storage package according to any one of claims 1 to 3, the electronic component mounted on the electronic component storage package, and the metallization layer for sealing are joined to each other via a brazing material. An electronic device comprising a metal lid.

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