JP2004179373A - Electronic parts package and its sealing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic parts package capable of realizing improved reliability as electronic parts by reducing damage to a container for mounting electronic parts thereon by a beam being welding means used for sealing and suppressing the formation and occurrence of hole and crack or the like, in the electronic parts package for hermetically sealing the container by covering it with a lid. <P>SOLUTION: The container 1 at an opening top of which a metalized layer 2 is formed, and of the lid 3 where plate thickness T2 of an outer periphery end 3b is formed thinner than a principal section 3a are used. After the lid 3 is put on the container opening, the outer periphery end 3b of the lid 3 or its end boundary is irradiated thereon or therealong with laser light for heating and melting thereof. Consequently, the container 1 and the lid 3 are melted and joined with each other to realize the hermetically sealed electronic parts package. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, an electronic component such as a piezoelectric vibrator or a semiconductor is mounted inside a container in which one side is opened to form a space, and a lid is placed over the opening of the container. The present invention relates to an electronic component package for hermetically sealing components and a sealing method therefor.
In particular, the present invention relates to an electronic component package most suitable for a structure using a laser beam at the time of hermetic sealing and a sealing method therefor.
[0002]
[Prior art]
A conventional package structure of this type is disclosed in Japanese Patent Application Laid-Open No. 8-46075 (Japanese Patent Application No. 6-197573) proposed by the present applicant.
[0003]
[Problems to be solved by the invention]
The technology used for the package of electronic parts here is that which is performed by using electron beam welding or laser beam welding at the time of hermetic sealing, and the thickness of the metallized layer formed on the top of the opening of the container. By using a container having a larger thickness than before and irradiating a beam from above on the lid using the above-described welding technique to heat and melt the lid, a metal plating layer at the top of the opening of the container is formed. It is to be fused and sealed. With this configuration, it has been possible to provide an electronic component package that prevents damage to the container due to overheating due to beam irradiation during fusion bonding, as compared with the prior art.
[0004]
However, even with the above-described configuration, the amount of irradiation energy required for electron beam welding or laser beam welding does not change and is still large, so that the container sometimes has holes or cracks. For example, damages that impair the reliability of the electronic component have occurred.
[0005]
A lid 32 having an outer dimension smaller than the outer dimension a of the container 31 as shown in FIG. 2 may be used. In this case, too, the energy of the laser irradiated to the end of the lid 32 is controlled. It will be extremely difficult. The laser has a spot diameter of a certain size due to its characteristics, and most of the spot is irradiated to the end of the lid 32, but part of the laser is located on the outer peripheral side of the top of the container 1 as shown in the drawing because of difficulty in control. Direct irradiation is performed, and as a result, the metallized layer 31a formed on the top of the container 1 receives large energy as it is. In this case, the possibility that the laser penetrates the metallized layer 31a is increased as compared with the configuration described in the above-mentioned publication, in which case the damage to the container itself under the layer protected by the metallized layer 31a is further increased, It is expected that the reliability as an electronic component will be greatly impaired.
[0006]
In FIG. 2, the left end of the lid 32 is in a state of being melted and bonded to the metallized layer 31a on the top of the container 31 by laser irradiation.
[0007]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and by paying attention to the shape of the lid, sufficient sealing can be achieved even if the laser energy is reduced without reducing the strength of the lid. It has been realized. As a result, the laser beam or electronic beam damage to the container during welding can be reduced without deteriorating the inherent strength of the lid, and the occurrence of holes and cracks in the container can be suppressed. Further, an object of the present invention is to provide an electronic component package with higher reliability in consideration of suppressing occurrence of distortion of a container even after heating after sealing.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, in an electronic component package according to the present invention, a lid for closing a top portion of an opening of a container is formed to have a small thickness at an outer peripheral end portion. A laser is applied to the outer peripheral end having a small thickness or the periphery of the boundary with the top of the opening of the container, and the two are melt-bonded to seal the container after the electronic components are mounted.
As a result, sufficient fusion bonding can be achieved even with a small irradiation energy of the laser, and as a result, damage to the container during sealing can be minimized.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of an electronic component package according to the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view showing an embodiment of an electronic component package (electronic components are not shown) according to the present invention.
In FIG. 1, since the metallized layer is very thin compared to the dimensions of the container, it is shown in a deformed form so that the present invention can be easily understood.
[0010]
Here, a laser used at the time of welding will be described. Excimer lasers, carbon dioxide lasers, and YAG lasers are known as lasers used for welding. Among them, a YAG laser is suitable for sealing welding, spot welding, and seam welding.
Since this YAG laser has a short wavelength and excellent light-collecting properties, it can obtain a fine spot diameter of about 0.2 to 0.3 mm required for welding small electronic components as in the present invention. It is a laser which is easy to perform and can be expected to suppress the thermal influence on the work material relatively small. Therefore, in the YAG laser, it is possible to process a small area with a low output, and as a material suitable for the processing, it is possible to realize a welding process with a small distortion to a metal, a ceramic or the like having a high light absorption rate. Things.
In the case of a carbon dioxide laser, a metal is a material suitable for processing, and in the case of an excimer laser, examples of a material suitable for processing include glass, resin, and ceramics.
[0011]
In FIG. 1, reference numeral 1 denotes an insulating material, which is made of a material having a small coefficient of thermal expansion, for example, a ceramic material, and has electronic components (not shown) such as a piezoelectric vibrator and a semiconductor mounted in a space formed by opening one side. It is a rectangular container whose one side is about 1.5 to several millimeters. Reference numeral 2 denotes a metallized layer formed all around the top of the opening of the container 1, and is formed by sequentially laminating a tungsten layer 2a and a metal plating layer 2b such as nickel plating.
[0012]
Reference numeral 3 denotes a lid that covers the top of the opening of the container 1, and the entire outer dimension X is smaller than the outer dimension A of the container 1 and larger than the opening B of the container 1. Further, a step is formed in the lid 3 to form an outer peripheral end 3b, and the plate thickness T2 is formed thinner than the plate thickness T1 of the main portion 3a.
At this time, the main portion 3a of the lid 3 has the same thickness as before because it needs to withstand pressure from above and maintain a strength capable of protecting the electronic components, and its size is the same as the container opening dimension B. It is formed to exceed. At this time, the outer dimension X of the entire lid 3 including the outer peripheral end 3b is formed slightly smaller than the outer dimension A of the container 1. Therefore, the outer peripheral end 3b formed outside the main portion 3a of the lid 3 is formed to be narrower than the width C of the top of the opening of the container 1 in preparation for fusion bonding by a laser in a later step.
[0013]
The lid 3 having the thickness and dimensions of the main portion 3a and the outer peripheral end portion 3b of the lid 3 is formed such that the main portion 3a of the lid 3, which is the plate thickness portion, and the container 1 against the pressing force from above. And the lid main portion 3a having the same thickness as before can be used. Therefore, its strength is not inferior to that of the conventional lid, and the plate thickness T1 Without increasing the thickness, a thickness comparable to that of the related art is sufficient. The step between the main portion 3a and the outer peripheral end 3b of the lid 3 can be easily formed by pressing or half etching, and thereafter, if necessary, for the purpose of surface protection or the like, a metal plating layer (not shown). Are formed.
Further, as the material used for the lid 3, considering the heating process at the time of sealing which will be a subsequent process, the thermal expansion coefficient of the container 1, in this case, a material close to the thermal expansion coefficient of the ceramic material, Is appropriate.
[0014]
Hereinafter, the electronic component package and the method for hermetically sealing the electronic component package according to the present invention in the above configuration will be described in order with reference to FIG.
First, the tungsten layer 2a is formed by printing over the entire circumference of the top of the container 1.
At this time, the thickness of the tungsten layer 2a is set to about 10 to 30 μm in consideration of suppressing and reducing the influence of damage to the container 1 during heating and melting for hermetic sealing. It is desirable.
[0015]
Thereafter, a metal plating layer 2b is formed on the surface of the tungsten layer 2a. Specifically, a nickel plating layer is formed, but if necessary, a gold plating layer (not shown) can be further formed thereon.
[0016]
After mounting an electronic component such as a piezoelectric vibrator or a semiconductor (not shown) inside the container 1 having the metallized layer 2 formed on the top of the opening as described above, the lid 3 is attached as shown in FIG. The container 3 is put on the container 1 while being positioned so that the position 3a closes the opening of the container 1.
At this time, the outer dimension X of the lid 3 is formed as a dimension that can be placed on the metallized layer 2 of the container 1 as described above, in other words, an outer dimension slightly smaller than the outer dimension A of the container 1. The dimensions which do not hinder the fusion bonding with the metallized layer 2 at the top of the opening of the container 1 are secured.
[0017]
Here, the relationship between the dimensions of each part up to now
External dimensions A of container 1> External dimensions X of lid 3> Main part dimensions Y of lid 3> Opening dimension B of container 1
It can be understood that the relationship holds.
[0018]
Next, for example, a YAG laser is placed on the outer peripheral end 3b of the lid 3 placed on the top of the opening of the container 1 or near the boundary with the metallized layer 2 at the top of the opening of the container 1. A laser having a spot diameter of about 0.2 to 0.3 mm is irradiated to melt the outer peripheral end 3b of the lid 3 and melt-bonded via the top of the opening of the container 1, in this case via the metallized layer 2. Then, the container 1 on which the electronic components are mounted is hermetically sealed.
[0019]
At this time, the energy irradiated by the YAG laser can be suppressed by the thickness T2 of the outer peripheral end 3b of the lid 3 to be melted which is smaller than that of the conventional one. In the case where the thickness is formed to be half the plate thickness, it is expected that the amount of energy of the laser to be irradiated can be reduced to almost half as a standard.
As a result, the amount of energy to be irradiated can be reduced and the damage to the top of the opening of the container 1 can be reduced. Therefore, the hole and crack in the container 1 caused by the conventional heating by the laser at the time of welding can be obtained. It is possible to reduce the effect of impairing the reliability of the electronic component as the final product, such as the occurrence of cracks.
[0020]
In the above description of the embodiment, a step is provided as an example in which the thickness of the outer peripheral end 3b of the lid 3 is reduced. However, as another embodiment, the thickness of the outer peripheral end of the lid 3 is mainly It goes without saying that the desired effect of the present invention can be obtained even if a taper is formed (not shown) so as to become thinner from the portion 3a toward the outer peripheral end side.
[0021]
Further, although a YAG laser has been described as a welding means, the present invention is not particularly limited to this, and other welding means such as an excimer laser may be used in accordance with the material used for the container 1 and the lid 3. It is described that the intended purpose of the present invention can be achieved and the effect can be obtained even if a laser, a carbon dioxide laser, or another electron beam is appropriately selected and used. Not even.
[0022]
Irradiation conditions of the laser to the melting point of the lid 3 are usually set at room temperature and in an atmosphere of an inert gas in consideration of minimizing the influence of damage to the container 1 due to heating. Although it is performed, it is not always necessary to be in an atmosphere of an inert gas atmosphere, and there is no problem even in a vacuum environment.
[0023]
Further, as an embodiment of the material of the container 1, a ceramic material has been described. However, other materials may be used as long as they are insulators. Needless to say, what can be expected.
[0024]
Further, as one embodiment of the metallized layer 2, a structure in which a tungsten layer and a metal plating layer are stacked has been described. However, even if the tungsten layer is replaced with a molybdenum (element symbol Mo) layer, the expected effect of the present invention is achieved. Can be expected.
[0025]
Further, the thermal expansion coefficient of the material of the container 1 and the lid 3 prevents the heat applied at the time of sealing from affecting each other, and the sealing portion due to the difference in the expansion rate even when heated after hermetic sealing. Therefore, it is preferable to use the same combination or a combination having a small difference between them in order to suppress the occurrence of distortion in the above.
[0026]
【The invention's effect】
As described above in detail, according to the electronic component package and the method of hermetically sealing the same according to the present invention, the package for mounting the electronic component upon heating and melting by the laser beam at the time of sealing is used. Since the damage can be reduced, an effect of providing an electronic component package with improved reliability can be expected.
In addition, by considering the combination of materials used for the container 1 and the lid 3, it is possible to suppress the occurrence of distortion in the sealed portion even when heating after hermetic sealing. Further effects can be expected to improve the reliability of the device.
[0027]
Further, in another embodiment in which a taper is formed at the outer peripheral end of the lid, the laser beam used for sealing is reflected back to the light source side of the beam as it is depending on the angle of the taper. Therefore, the effect of preventing damage to the beam light source can be expected.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an embodiment of an electronic component package according to the present invention.
FIG. 2 is a cross-sectional view showing an example of a conventional electronic component package configuration.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Container 2 Metallized layer 2a Tungsten layer 2b Metal plating layer 3 Lid 3a Principal part of lid 3b Outer end of lid A External dimensions of container B Dimension of opening of container C Width of top of container X External dimensions of lid Y Principal part of lid Dimension of part T1 Thickness of main part of lid T2 Thickness of outer peripheral end of lid

Claims (9)

An electronic component that mounts an electronic component such as a piezoelectric vibrator or a semiconductor inside a container with one side open to form a space, covers the container opening with a lid, and melt-bonds the container and the lid to seal the electronic component In the parts package,
At the top of the opening of the container, at least a metal plating layer is laminated to form a metallized layer, and the lid forms an outer peripheral end portion whose plate thickness is thinner than the main portion,
An electronic component package, wherein the lid is placed in the container opening, and the outer peripheral end of the lid and the container opening top are heated and melt-bonded by welding means to form a hermetically sealed structure. The electronic component package according to claim 1,
The outer dimensions of the lid are slightly smaller than the outer dimensions of the container so that the lid can be placed and welded on the opening of the container,
An electronic component package characterized in that an outer dimension of a main part is larger than a dimension of an opening of a container and is formed to be thicker than a plate thickness of an outer peripheral end. The electronic component package according to claim 1,
An electronic component package characterized in that the lid is formed so as to have a step so that a thickness of an outer peripheral end portion of the lid is smaller than a main portion. The electronic component package according to claim 1,
An electronic component package, wherein an outer peripheral end of the lid is formed narrower than a width of an opening top of a container. The electronic component package according to claim 1,
An electronic component package, wherein a taper is formed so that a thickness of an outer peripheral end portion of the lid decreases from a main portion side of the lid toward an outer peripheral end portion. The electronic component package according to claim 1,
An electronic component package, wherein an insulating material is used as a material of the container. The electronic component package according to claim 1,
An electronic component package wherein the container and the lid are formed by combining materials having the same or similar thermal expansion coefficients. The electronic component package according to claim 1,
An electronic component package wherein the container is formed of a ceramic material and the lid is formed of a cover material. An electronic component that mounts an electronic component such as a piezoelectric vibrator or a semiconductor inside a container with one side open to form a space, covers the opening of the container, melts the container and the lid, and seals the electronic component In the method of sealing a component package,
At the top of the opening, at least a container having a metallized layer formed by laminating a metal plating layer,
Using a lid formed with a plate thickness of the outer peripheral part thinner than the main part plate thickness,
An electronic component package having a structure in which after the lid is placed on the container opening, the outer peripheral end of the lid and the opening top of the container are melt-bonded using a YAG laser and hermetically sealed. J sealing method.

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