JPH11307661A - Electronic component package and method of manufacturing electronic component package - Google Patents

Abstract

(57) [PROBLEMS] To provide a method for positioning a ceramic package and a lid at a predetermined position without using a positioning jig, and to reliably perform hermetic sealing even in a microminiaturized electronic component. Provided are a package for an electronic component and a method for manufacturing the same. SOLUTION: A concave ceramic package 1 having an open upper part, a crystal vibrating plate 3 as an electronic element housed in the package, and a metal lid 2 joined to an opening of the package. . The lid 2 has a peripheral solder layer 21 corresponding to the peripheral metal layer 11 formed on the lower surface of a metal base material 20 such as Kovar. When performing hermetic sealing,
The lid 2 and the metal layer of the ceramic package 1 are overlapped, and the ambient temperature is set to the solder melting temperature and melted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package for electronic parts, and more particularly to a package for electronic parts requiring hermetic sealing.

[0002]

2. Description of the Related Art Examples of electronic components requiring hermetic sealing include quartz crystal products such as quartz oscillators, quartz filters and quartz oscillators. In each of these, a metal thin-film electrode is formed on the surface of a quartz vibrating plate and hermetically sealed to protect the metal thin-film electrode from the outside air.

[0003] Hermetic sealing methods include solder joining, low melting point glass joining, resistance welding, and electron beam welding. As a hermetic sealing method using resistance welding, a quartz oscillator using an HC-49 / U type base is widely used. This is a configuration in which a base in which lead terminals are implanted in a metal shell in a state in which they are insulated from each other via insulating glass, and a metal cap are hermetically sealed by resistance welding. It is widely used as a method for hermetically sealing components.

According to such a joining method by resistance welding, a metal-to-metal joint is performed, so that a highly airtight sealing method can be obtained. However, the base and the cap need to be pressed against each other at the time of hermetic sealing, and the distortion at the time of pressing may adversely affect an electronic element such as a quartz plate housed in a package.

Further, as shown in a conventional example of Japanese Patent Application Laid-Open No. 7-326687, a seal ring (metal frame) formed at an opening portion of a ceramic package and a metal lid are formed.
A joining method corresponding to surface mounting for hermetically sealing by seam welding, which is one type of resistance welding, is also employed.

The configuration required for seam welding will be described with reference to FIG. FIG. 6 is a partially enlarged sectional view of the ceramic package and the metal lid. A seal ring 71 made of Kovar or the like is joined to the upper surface of the opening 70a of the ceramic package 70 by brazing. Then, a metal lid 72 made of Kovar or the like is mounted on the seal ring, and a pair of welding rolls 73 (the other is not shown) are energized while tracing the ridges on the outer periphery of the metal lid 72 to seal the metal lid. The rings were joined. The outer periphery of the metal lid is formed slightly smaller than the outer periphery of the seal ring, and the step portion b
Are formed to ensure the joining of the two.

[0007] However, as is apparent from FIG.
When seam welding is performed, a meniscus portion a of a brazing material is required on the upper surface 70a of the opening, and the above-described step portion b is required. Therefore, a substantial joining portion between the metal lid and the seal ring becomes the joining region c. For example, in the case of a package having a length of 6 mm and a width of 3 mm, the width a1 of the meniscus portion is 0.2 mm and the width b1 of the step portion is 0.1.
mm, and the width c1 of the bonding region is about 0.2 mm. This joint area 0.2 mm is substantially the minimum dimension in terms of airtight reliability. That is, in seam welding, the joining region c
Therefore, it is necessary to form a meniscus portion a and a step portion b in order to obtain the electronic component, and in the case of an ultra-miniaturized electronic component, it is not possible to secure an electronic element storage area, which is not suitable for miniaturization of the electronic component.

In addition, it is necessary to bring the welding tip into contact with the member to be joined at the time of joining. However, as each component becomes minute, the welding tip and the like interfere with each other, making it difficult to cope with miniaturization. There were also problems.

As a means for joining to a member to be joined in a non-contact manner, a method of performing hermetic sealing by electron beam welding or laser beam welding as disclosed in Japanese Patent Application Laid-Open No. 8-46075 has been considered.

However, even in such various types of beam welding, a jig for positioning and fixing the metal lid on the case is required at the time of welding. It has been difficult for such a jig to cope with miniaturization of each component.

[0011] Solder bonding has long been used as a method for hermetically sealing packages for electronic components. For example, Japanese Patent Laying-Open No. 52-22493 discloses a configuration in which a soft brazing material such as solder is formed on a sealing surface of a lid and the lid is sealed. In this publication, solder or the like formed by thermocompression bonding is melted, and solder joining is performed by applying pressure to the lid by mechanical contact with heating. Although not explicitly described in this publication, a jig for positioning the lid in such solder bonding is essential, and thermocompression bonding is performed with the jig positioned. As described above, a jig is required for soldering, and there is a problem that it is impossible to cope with miniaturization of each component.

[0012]

As described above, in recent years, there has been a demand for smaller electronic components, and in the field of piezoelectric vibrators, which were conventionally difficult to miniaturize,
For example, a surface-mounted crystal resonator having an outer size of about 3 mm in length, 2 mm in width, and about 0.8 mm in height has been devised. In such a crystal resonator, it is necessary to cope with the miniaturization of the crystal vibrating plate, and it is necessary to devise a package for accommodating the crystal vibrating plate, and it is not possible to cope with the technology conventionally used.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and even in an ultra-miniaturized electronic component, the joining between the ceramic package containing the electronic element and the lid can be performed without using a positioning jig. An object of the present invention is to provide an electronic component package which can be positioned at a predetermined position and reliably perform hermetic sealing, and a method of manufacturing the same.

[0014]

SUMMARY OF THE INVENTION The present invention has been made by paying attention to the surface tension of molten low-melting metal (solder or the like) or glass. In order to perform self-correction (self-alignment) action by surface tension, positioning and airtight joining are performed.

An electronic component package according to claim 1 is
A ceramic base, a first bonding portion composed of at least one layer formed in a peripheral shape around the main surface of the ceramic base, and a second bonding portion bonded corresponding to the first bonding portion are formed around the first bonding portion. An electronic component package comprising a lid formed in a shape, and performing hermetic bonding by melting at least one of the two bonding portions, wherein the width of each of the bonding portions is approximately equal, or It is characterized in that the width of the joint to be melted is formed wide.

As an example of each of the above-mentioned joints, at least the surface layer of the joint to be melted may be made of a low melting point metal, and more specifically, a solder as described in claim 3 And other soft waxes. The formation of these solder layers and the like can be performed with a clad material obtained by a rolling method or by various platings. Since the formation by rolling does not use a binder or the like, gas emission during melting is small, and adverse effects due to gas can be avoided, which is preferable.

As a more specific configuration, as set forth in claim 4, a ceramic base, at least one metal layer formed circumferentially around a main surface of the ceramic base, and The corresponding solder layer is a lid formed in a circumferential shape by a rolling method, and is a package for electronic components that performs hermetic bonding by melting the solder layer, wherein the width of the solder layer is A configuration characterized by being formed substantially equal to or wider than the width of the metal layer can be given. Since the solder uses a clad material using a rolling method, as described above, it is possible to avoid the adverse effect of the gas released during melting.

Taking the case where the joint to be melted is solder as an example,
The operation and the like according to the present invention will be described. Due to the melting of the solder, the mounting position of the lid is self-corrected with respect to the metal layer formed on the ceramic base, and the position is fixed. That is, by making the widths of the metal layer and the solder layer substantially equal or relatively narrowing the width of the metal layer, when the solder is melted, the mounting position of the lid with respect to the metal layer formed on the ceramic base is determined. Self-correction is performed by surface tension, and positioning and fixing are performed. For example, as shown in FIG. 2, even when the lid 2 is mounted with a displacement, the lid is slightly moved in the direction of the arrow X due to the surface tension at the time of melting the solder, and the lid is joined to a predetermined position.

If the width of the metal layer is smaller than the width of the solder layer, that is, if the width A of the metal layer is smaller than the width B of the solder layer shown in FIGS. Even if it does not function, the bonding area (seal path width) can be ensured, so that the reliability in bonding increases. In addition, it is necessary to allow for some manufacturing errors for ceramic substrates,
Even when such a manufacturing error occurs, or when a manufacturing error occurs when the solder layer is formed by the rolling method, a manufacturing error occurs in the formation of the low-melting glass, etc., the bonding area is the same as described above. (Seal path width) can be ensured, so that the reliability in joining increases. If the width of the solder layer is too large than the width of the metal layer, the released gas during melting of the solder is likely to accumulate inside the package.

As a method of manufacturing the electronic component package as described above, a manufacturing method as described in claim 5 can be mentioned. That is, a ceramic base, a metal layer composed of at least one layer formed in a circumferential shape around the main surface of the ceramic base and having a melting point higher than that of solder, and a solder layer to be joined corresponding to the metal layer are formed in a circumferential shape. A method for manufacturing an electronic component package comprising: a lid formed and performing a hermetic bonding by melting the solder layer, wherein the width of the solder layer is substantially equal to or larger than the width of the metal layer. A step of mounting the lid with the solder layer corresponding to the upper surface of the metal layer; and setting the ambient temperature of the ceramic base on which the lid is mounted to the melting temperature of the solder layer, and melting the solder layer. Self-correcting the relative position of the lid with respect to the ceramic substrate by the surface tension of the molten solder acting at this time; and thereafter, lowering the ambient temperature and curing the solder layer. And performing an airtight joint, a manufacturing method characterized by comprising.

Further, as set forth in claim 6, one or both of the joints may be made of low-melting glass.

According to this structure, the same modification and operation as those in the case of using the solder joint of the first aspect can be obtained, and the generation of outgassing is smaller than that of solder or the like. It does not adversely affect the electronic elements housed in the device.

As a production method using a low melting point glass,
As described in claim 7, the ceramic base, the first low melting point glass layer formed circumferentially around the main surface of the ceramic base, and the first low melting point glass layer are joined correspondingly. A method for manufacturing an electronic component package, comprising: a second low melting point glass layer formed in a circumferential shape; and a lid for performing hermetic bonding by melting the low melting point glass layer. Forming the width of the layer substantially equal to or wider than the width of the first low-melting glass layer, and setting the second low-melting glass layer to correspond to the upper surface of the first low-melting glass layer. Mounting the lid,
The ambient temperature of the ceramic substrate on which the lid is mounted is defined as the melting temperature of the low-melting glass layer, these low-melting glass layers are melted, and the relative position of the lid with respect to the ceramic substrate is determined by the surface tension of the molten glass that acts at this time. Self-correcting, and then lower the ambient temperature,
A step of curing the low-melting glass layer and performing airtight bonding;
And a method for manufacturing an electronic component package, comprising:

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 1, 2, 3 and 4 taking a surface mount type crystal unit as an example. FIG. 1 is an internal cross-sectional view showing the present embodiment, FIG. 2 is a view showing an example in which a lid slightly moves by a self-correcting action, FIG. 3 is a plan view of a ceramic package, and FIG. is there. The basic configuration is as shown in FIG. 1, wherein a concave ceramic package 1 having an open top, a quartz vibrating plate 3 as an electronic element housed in the package, and an opening of the package are joined. Metal lid 2.

A ceramic package 1 having a concave shape in cross section
Consists of a ceramic base 10 and a peripheral metal layer 11 formed in an opening around the concave shape. The metal layer 11 includes a metallized layer 11a made of tungsten or the like, a lower plated layer 11b made of nickel or the like formed on the metallized layer, and an upper plated layer 11c made of gold or the like formed on the lower plated layer. Consists of In this embodiment, the thickness of each layer is 18 to 20 μm for the metallized layer 11, 6 μm for the lower plating 12 and 1 μm for the upper plating layer 13.

Further, electrode pads 12 and 13 are formed on the inner bottom surface of the ceramic package 1, and these electrode pads are electrically connected to the bottom surface outside the package as connecting electrodes 16 and 17 via connecting electrodes 14 and 15. Has been drawn to. A rectangular crystal vibrating plate 3 as an electronic element is mounted between the electrode pads 12 and 13. Although not shown, a pair of excitation electrodes are formed on the front and back surfaces of the quartz vibrating plate 3, are respectively drawn to the electrode pads 12 and 13, and are conductively bonded by conductive bonding materials S1 and S2.

As shown in FIGS. 3 and 4, the lid 2 for hermetically sealing is formed by forming a peripheral solder layer 21 corresponding to the peripheral metal layer 11 on the lower surface of a metal base material 20 such as Kovar. I have.
The lid 2 may use a ceramic plate instead of a metal material. The solder layer 21 is formed by, for example, a rolling technique, but may be formed by a plating technique or the like.
In this embodiment, the width of the solder layer 1
2 is set wide. More specifically, the outer dimensions of the ceramic package are 3.2 mm in length, 2.5 mm in width, 0.7 mm in height, and the outer dimensions of the lid are 3.1 mm in length and 2.4 m in width.
m, the height (thickness) is 0.1 mm, the width of the metal layer is 0.5 mm, and the width of the solder layer is 0.7 mm. The solder layer extends 0.2 mm inside the package.

When the hermetic sealing is performed, the lid 2 and the metal layer of the ceramic package 1 are overlapped, and the ambient temperature is set to the solder melting temperature to be melted. More specifically, the solder is melted by passing through a reflow furnace set at the melting temperature of the formed solder. By this melting, the mounting position of the lid is determined by self-correction with respect to the metal layer formed on the ceramic base. As described above, for example, even when the lid 2 is shifted and mounted as shown in FIG. 2, the lid moves slightly in the direction of arrow X when the solder is melted, and the lid is positioned at a predetermined position. Fixed.

Another example of the embodiment according to the present invention will be described with reference to FIG. 5, taking a surface mount type crystal unit as an example. In this example, the hermetic bonding is performed using low-melting glass.
The basic configuration is similar to the configuration shown in the above-described embodiment, and includes a concave ceramic package 4 having an open top, a crystal vibrating plate 6 which is an electronic element housed in the package, and a package. And a lid 5 joined to the opening of the main body.

A ceramic package 4 having a concave shape in cross section
Consists of a ceramic base 40 and a circumferential low melting point glass layer 41 formed in an opening around the concave shape. The electrode pads 42 and 4 are provided on the inner bottom surface of the ceramic package 4.
3 (43 not shown) are formed, and these electrode pads are electrically drawn as lead electrodes 45 and 46 to the bottom surface outside the package via the connection electrodes 44 and the like. A rectangular crystal vibrating plate 6 as an electronic element is mounted between the electrode pads 42 and 43, and one end in the longitudinal direction is cantilevered. Although not shown, a pair of excitation electrodes are formed on the front and back surfaces of the quartz vibrating plate 6, and are respectively drawn to the electrode pads 42 and 43.
Is electrically conductively bonded.

The lid 5 to be hermetically sealed is provided on the lower surface of a ceramic plate made of alumina or the like.
A low-melting glass layer 51 having a circumferential shape corresponding to.
In this embodiment, the width of the low melting point glass layer 51 is set to be larger than the width of the low melting point glass layer 41.

When the hermetic sealing is performed, the low-melting glass layers are overlapped with each other, and are melted at an ambient temperature of the low-melting glass melting temperature. More specifically, the low-melting glass is melted by passing through a reflow furnace set at the melting temperature of the formed low-melting glass layer. By this melting, the mounting position of the lid is determined by self-correction.

Note that, instead of the low melting point metal layer 41 formed on the package side, an alumina coat layer narrower than the low melting point glass layer 51 may be used.

Although the present invention has been described with reference to a surface-mount type crystal resonator, the present invention may be applied to a package for a piezoelectric filter or a piezoelectric oscillator, or to other electronic parts requiring hermetic sealing. May be applied.

[0035]

According to the present invention, the mounting position of the lid is self-corrected and fixed by the melted joint. Therefore, airtight joining can be performed without the need for a positioning jig at the time of joining, which was required in the conventional airtight joining method.
Therefore, even in a very small electronic component package, good airtight joining can be achieved. In addition, since airtight bonding can be performed without making mechanical contact with individual packages, airtight sealing of a large number of electronic components can be performed at once, and airtight bonding excellent in productivity can be obtained. Can be.

According to the fourth aspect, since the solder is formed by the rolling method, gas emission during melting of the solder is small, and the adverse effect on the electronic elements inside the package can be minimized. Therefore, the reliability of the electronic component is improved, for example, the change over time as the electronic component is stabilized.

According to the sixth aspect, since the low melting point glass is used for the bonding portion, there is an advantage that the reliability of the electronic component is improved, such as a small amount of outgassing at the time of bonding and a stable change over time as the electronic component. Have.

According to the fifth and seventh aspects, the ambient temperature is set to the melting temperature of the solder or the low-melting glass, and the melting of the solder layer or the low-melting glass layer formed on the lid is promoted. Since the position is self-corrected, efficient manufacturing can be performed.

[Brief description of the drawings]

FIG. 1 is an internal cross-sectional view according to a first embodiment.

FIG. 2 is a diagram showing a movement state of a lid according to the first embodiment.

FIG. 3 is a plan view of a ceramic package.

FIG. 4 is a plan view seen from the back surface of the lid.

FIG. 5 is an internal cross-sectional view showing another embodiment.

FIG. 6 is a diagram showing a conventional example.

[Explanation of symbols]

 1, 4 Ceramic package 10, 40 Ceramic substrate 11, 41 Metal layer 11a Metallization layer 11b Lower plating layer 11c Upper plating layer 2, 5 Lid 20 Metal base material 21 Solder layer 3, 6 Quartz crystal plate (electronic component element)

Claims (7)

[Claims] 1. A ceramic substrate, a first joining portion composed of at least one layer formed circumferentially around a main surface of the ceramic substrate, and a second joining portion corresponding to the first joining portion. Is a cover formed in a peripheral shape, and a package for electronic components that performs hermetic bonding by melting at least one of the two bonding portions, wherein the width of each of the bonding portions is An electronic component package, wherein the width of a joining portion that is substantially equal to or melts is formed to be wide. 2. The electronic component package according to claim 1, wherein at least a surface layer of the joining portion to be melted is made of a low melting point metal. 3. The electronic component package according to claim 2, wherein said low melting point metal is solder. 4. A ceramic substrate, a metal layer having a melting point higher than that of solder and comprising at least one layer formed circumferentially around a main surface of the ceramic substrate, and a solder layer corresponding to the metal layer. An electronic component package comprising a lid formed in a circumferential shape by a rolling method and performing hermetic bonding by melting the solder layer, wherein the width of the solder layer is substantially equal to the width of the metal layer or An electronic component package characterized by being widely formed. 5. A ceramic substrate, a metal layer having a melting point higher than that of solder and comprising at least one layer formed circumferentially around a main surface of the ceramic substrate, and a solder layer corresponding to the metal layer. A method for manufacturing an electronic component package, comprising: a lid formed in a circumferential shape and performing hermetic bonding by melting the solder layer, wherein the width of the solder layer is substantially equal to the width of the metal layer, or Forming the solder layer on the upper surface of the metal layer, and mounting the lid on the upper surface of the metal layer; setting the ambient temperature of the ceramic base on which the lid is mounted to the melting temperature of the solder layer; And a step of self-correcting the relative position of the lid with respect to the ceramic substrate by the surface tension of the molten solder acting at this time.After that, lowering the ambient temperature and removing the solder layer Process and method of manufacturing an electronic component package, characterized in that it consists of performing an airtight joint is of. 6. The method according to claim 1, wherein one or both of the joints are made of low-melting glass.
Electronic component package as described. 7. A ceramic base, a first low melting point glass layer formed circumferentially around a main surface of the ceramic base, and a second joint corresponding to the first low melting point glass layer. A method for manufacturing a package for an electronic component, comprising: a lid having a low melting point glass layer formed circumferentially; and a hermetic bonding by melting the low melting point glass layer, wherein the width of the second low melting point glass layer is Forming the first low-melting glass layer substantially equal to or wider than the first low-melting glass layer, and mounting the lid so that the second low-melting glass layer corresponds to the upper surface of the first low-melting glass layer And setting the ambient temperature of the ceramic substrate on which the lid is mounted as the melting temperature of the low-melting glass layer, melting these low-melting glass layers, and causing the surface tension of the molten glass to act on the ceramic substrate. A process of self-correcting the relative position of the lid, and thereafter, a process of lowering the ambient temperature, hardening the low-melting glass layer, and performing hermetic bonding. .