JP2003197794A - Package for electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the clearness of an identification mark made by laser impression without giving damage such as a crack, breakage or the like to a ceramic package due to the laser impression, to allow the ceramic package adaptable to a thin-thick one, and to reduce a size and a height. <P>SOLUTION: The package for an electronic component is provided with a ceramic substrate 1 mounting an electronic element and a ceramic lid 2 for sealing the mounted electronic element airtightly. On the upper surface of at least one plane of the ceramic substrate or the ceramic lid, a color film H1 having a color different from that of the ceramic substrate or the ceramic lid. Then, the upper surface is irradiated with such a low-power laser which burns up only the color film to form an identification mark M where the ceramic substrate or the ceramic lid is partially exposed. <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 structure for forming an identification mark on a ceramic package for electronic parts, and particularly to a structure for a piezoelectric vibration device such as a piezoelectric vibrator or a piezoelectric filter.

[0002]

2. Description of the Related Art An example of a package for electronic parts which requires hermetic sealing is a package for a piezoelectric vibrating device such as a crystal oscillator, a crystal filter, a crystal oscillator or a SAW filter. In all of these, a metal thin film electrode is formed on the surface of a quartz diaphragm (piezoelectric diaphragm), and the metal thin film electrode is hermetically sealed in order to protect the metal thin film electrode from the outside air.

Due to the requirement for surface mounting of these piezoelectric vibrating device products, the structure in which they are hermetically housed in a ceramic package (generally, the alumina content is about 90% and the base is black ceramic) is increasing. is doing. When using such a ceramic package, various bonding methods for bonding the package base and the lid have been studied. For example, solder joint, resin joint, low melting point glass joint,
There are various joining methods such as resistance welding and electron beam welding. One of the joining methods that is often used is hermetic sealing with low melting point glass.

The airtight sealing using the low melting point glass can reduce the cost of the parts associated with the sealing, and further, the batch processing can be performed so that a large number of joints can be performed at the same time. Can also be reduced. Further, since the package has a relatively simple sealing structure, it has advantages that it is easy to cope with downsizing and height reduction, and a relatively large area for accommodating electronic elements can be secured.

In particular, in the case of a surface mount type crystal resonator that vibrates in thickness shear vibration, it is often used for a low frequency type crystal resonator element having a relatively large size, and the package is thin and relatively wide. Is taking.

Further, in the ceramic package product as described above, one of the top surface of the lid, the bottom surface of the base, and the side surface is
An identification mark such as a manufacturing company name, a product name, and a manufacturing lot number is imprinted on a department or the like. As a marking means for this identification mark, in recent years, a laser marking for irradiating a laser or the like has been widely used instead of the offset marking using ink. Compared with the offset marking, the marking speed is extremely fast and accurate, and the marking is hard to erase. Further, there is an advantage peculiar to the laser marking that the marking step can be shortened without the need for marking.

However, in the ceramic package, the identification mark by the laser marking is liable to be unclear, and in order to improve the sharpness, it is necessary to increase the laser power to burn out the ceramic package.
When the power of the laser is increased to burn out the ceramic package, cracks may occur in the sealing portion between the ceramic base and the ceramic lid, or the ceramic itself may be broken in the thin ceramic package. In particular, in a glass-sealed product, cracks are likely to occur in the glass-sealed portion, and in the worst case, airtightness may be deteriorated. Further, the identification mark by laser marking cannot be applied to a thin ceramic package, which hinders downsizing and height reduction of the ceramic package.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a clear identification mark by laser marking can be provided without damaging the ceramic package by laser marking such as cracking or destruction. We provide a package for electronic parts that can be made compact and have a low profile while also improving the flexibility and supporting thin ceramic packages.

[0009]

In order to solve the above-mentioned problems, the present invention provides a ceramic base on which an electronic element is mounted, and a ceramic lid for hermetically sealing the mounted electronic element. An electronic component package comprising: a colored film having a color different from that of the ceramic base or the ceramic lid is formed on an upper surface of at least one plane of the ceramic base or the ceramic lid. It is characterized in that an identification mark is formed by exposing the ceramic substrate or a part of the ceramic lid by irradiating a laser with a power low enough to burn out only the film.

Further, as set forth in claim 2, in addition to the above-mentioned constitution, the ceramic base and the ceramic lid are glass-sealed.

Further, as described in claim 3, in addition to the above-mentioned structure, at least one of the ceramic substrate having the identification mark or the ceramic lid having the identification mark has a white color. It is characterized in that it is composed of a pure alumina ceramic and is formed with a dark colored film.

In addition to the above-mentioned structure, an identification mark is formed on the upper surface of the ceramic lid, and the ceramic lid is made of white high-purity alumina ceramic and has a dark color. The colored film is formed, and the ceramic lid is formed to be thinner than 0.25 mm.

[0013]

According to the first aspect of the present invention, the colored film is burned by being irradiated with the laser at the portion where the identification mark is formed, and the ceramic substrate having a different color from the colored film or the base material of the ceramic lid is exposed. Since the mark is provided, the contrast between the identification mark and the colored film is improved, and the identification mark can be written more clearly. Further, since the laser is irradiated with a power low enough to burn off only the colored film, even if the ceramic is irradiated with the laser, the ceramic is melted without crystallization, and cracks in the ceramic package by laser marking, It does not cause damage such as destruction.

According to the second aspect of the present invention, in addition to the above-described effects, even if the laser marking is applied to the glass-sealed product, cracks are not formed in the glass-sealed portion, and airtightness is prevented.

According to claim 3 of the present invention, in addition to the above-described effects, the ceramic base body having at least the identification mark or the ceramic lid is made of a white high-purity alumina ceramic, thereby providing a conventional ceramic package. Compared with, high density and high strength ceramic package can be obtained. Further, since it is a high-density and high-strength ceramic package, the airtightness as a package material is improved, and the effects of cracking and breaking due to laser marking can be dramatically reduced. Further, in the ceramic package, since the white identification mark is formed in the dark colored film, the definition of the identification mark is improved.

According to claim 4 of the present invention, in addition to the above-mentioned effects, further miniaturization of the ceramic package,
Low profile can be realized. In addition, as a ceramic package for electronic parts, an identification mark is formed on the upper surface of the ceramic lid that is most noticeable, and in the ceramic lid,
Since the white identification mark is formed in the dark colored film, the recognition degree and sharpness of the identification mark are dramatically improved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As a package for electronic parts according to a first embodiment of the present invention, a surface mount type crystal resonator will be described as an example with reference to FIGS. FIG. 1 is a perspective view showing a first embodiment of the present invention, and FIG. 2 is A- of FIG.
FIG.

The surface-mount type crystal unit has a rectangular parallelepiped shape as a whole, a flat plate-shaped ceramic base 1, a crystal vibrating plate 3 as an electronic element mounted on the upper surface of the base, and a reverse concave covering the upper part thereof. And a ceramic lid 2 that is open in shape. An accommodation space (mounting space) for the crystal vibrating element is formed by the reverse recessed portion of the lid.

The ceramic substrate 1 is made of a black ceramic (for example, 90% alumina-containing ceramics) in a flat plate shape. Ceramic base sealing area 11
A low melting point glass G for sealing is formed by printing.
Electrode pads 13 and 14 (13 is not shown) are formed side by side in the short side direction on the crystal vibrating element mounting surface 12 of the ceramic base. These electrode pads are connection electrodes 15 and 1
Via 6 (15 is not shown), electrodes 17 and 18 (17 are not shown) are electrically drawn to the bottom surface of the ceramic substrate. The electrode pads 13 and 14 include
A rectangular crystal diaphragm 3 is mounted, and one end in the long side direction is cantilevered. Although not shown, a pair of excitation electrodes are formed on the front and back surfaces of the crystal diaphragm 3 and are extended to the electrode pads 13 and 14, respectively, and the conductive bonding material S
Are electrically conductively joined together. The above-mentioned electrode pads 13, 1
4, connection electrodes 15 and 16, and extraction electrodes 17 and 18
Are formed by metallization.

The ceramic lid 2 is made of black ceramic (for example, 90% alumina-containing material) in a concave shape when viewed in cross section, and has an open end portion 21 and a covering surface portion 22.
It is equipped with. These shapes can be easily created by ceramic lamination technology. The open end 21
A low melting point glass G for sealing is formed by printing on
A white colored film H1 made of immortal ink or the like is formed on the upper surface of the covering surface portion 22.

Then, the opening end 21 of the ceramic lid is mounted on the sealing area 11 of the ceramic substrate, and in this state, it is put into a heating furnace for a predetermined time to melt the low melting point glass G, and then at room temperature. The low melting point glass is hardened by cooling to a low temperature, and is hermetically sealed. The colored film may be formed after being hermetically sealed.

In the hermetically sealed crystal unit package, an identification mark M such as a manufacturer name, a product name, and a production lot number is laser-printed on the upper surface of the ceramic lid. In the first embodiment of the present invention, a laser is irradiated with low power that burns out only the white colored film H1 formed on the upper surface of the lid 2 to expose the base material (black) of the lid and identify the mark. Forming M. As the power of the laser, the normal power of 15 to 16 mA,
12 to 13 mA, 70% to 90% of normal power
You can lower it to some extent.

In the first embodiment described above, the colored film is white, which has a different color from the black ceramic package (lid). However, it is preferable that the colored film is a bright color having an excellent contrast with respect to black. Even if it is yellow or red, there is no particular problem. Although the colored film is formed only on the upper surface of the lid on which the identification mark is formed, the colored film may be formed on the entire lid or the entire package including the base.

As a package for electronic parts according to the second embodiment of the present invention, a surface mount type crystal resonator will be described as an example with reference to FIGS. 3 and 4. FIG. 3 is a perspective view showing a second embodiment of the present invention, and FIG. 4 is a sectional view taken along line BB of FIG. The same parts as those in the first embodiment are designated by the same reference numerals, and part of the description is omitted.

The surface-mount type crystal unit is a rectangular parallelepiped-shaped ceramic substrate as a whole, a flat plate-shaped ceramic substrate 1, a crystal diaphragm 3 as an electronic element mounted on the upper surface of the substrate, and a reverse recessed portion to cover the upper part thereof. A ceramic lid 4 which is open in shape. An accommodation space (mounting space) for the crystal vibrating element is formed by the reverse recessed portion of the lid.

The ceramic lid 4 is a high-purity alumina ceramic with a white base (for example, 96% for containing alumina).
Is formed in an inverted concave shape when viewed in cross section by the opening end portion 41.
And a covering surface portion 42. These shapes can be easily created by ceramic lamination technology. A low melting point glass G for sealing is formed by printing on the opening end portion 41, and a black (dark color) colored film H2 made of immortal ink or the like is formed on the upper surface of the covering surface portion 42. . Further, the covering surface portion 42 of the ceramic lid is formed to have a thickness of 0.15 mm. For this reason, the lid thickness of a general glass-sealed ceramic package is 0.25 mm.
On the other hand, it has become possible to reduce the height by 0.1 mm.

Since the lid of the embodiment of the present invention is made of high-purity alumina ceramic, by making the lid to have a thickness of 0.1 mm or more and thinner than 0.25 mm,
A low profile can be realized without reducing the airtightness of the package lid. If the lid is formed to be thinner than 0.1 mm, the bending strength of the lid is reduced, the lid is warped, and the airtightness of the package as the lid is significantly reduced. On the other hand, if this lid is formed to have a thickness of 0.25 mm or more, it is not possible to achieve a low profile compared with the lid thickness of 0.25 mm in the conventional general glass-sealed ceramic package, and high purity alumina ceramic is used. No benefit.

Then, the open end portion 41 of the ceramic lid is mounted on the sealing area 11 of the ceramic substrate, and in this state, it is placed in a heating furnace for a predetermined time to melt the low melting point glass G, and then at room temperature. The low melting point glass is hardened by cooling to a low temperature, and is hermetically sealed. The colored film may be formed after being hermetically sealed.

In the hermetically sealed crystal unit package, an identification mark M such as a manufacturer name, a product name, and a production lot number is laser-printed on the upper surface of the ceramic lid. In the second embodiment of the present invention, a laser is irradiated with a low power that burns out only the black colored film H2 formed on the upper surface of the lid 2 to expose the base material (white) of the lid to expose the identification mark. Forming M. As the power of the laser, the normal power of 15 to 16 mA,
12 to 13 mA, 70% to 90% of normal power
You can lower it to some extent.

In the second embodiment, the colored film is made of black, which has a different color from the white ceramic lid.
It is preferable that the color is a dark color having an excellent contrast with respect to white. There is no particular problem even if it is gray or brown. Although the colored film is formed only on the upper surface of the lid on which the identification mark is formed, the colored film may be formed on the entire lid or the entire package including the substrate.

Next, as a package for electronic parts according to the third embodiment of the present invention, a surface mount type crystal oscillator will be described as an example with reference to FIGS. FIG. 5 is a perspective view showing a third embodiment of the present invention, and FIG. 6 is a sectional view taken along line CC of FIG.
FIG. The same parts as those in the first and second embodiments are designated by the same reference numerals.

The surface mount type crystal unit is a rectangular parallelepiped as a whole, and has a ceramic base 5 having a concave portion with an open top, a rectangular crystal vibrating plate 3 as an electronic element housed in the base, and the ceramic. It is composed of a flat plate-shaped ceramic lid 6 joined to the opening of the base. The concave portion of the ceramic base forms a housing space (element mounting portion) for the crystal vibrating element.

The ceramic substrate 5 is a high-purity alumina ceramic with a white base (for example, 96 for alumina-containing material).
%), It is formed in a concave shape when viewed in cross section, and the opening end 5
1 is provided with the peripheral wall portion 52 and the element mounting portion 53. Electrode pads 54 and 55 (54 is not shown) are formed side by side in the short side direction on the element mounting portion 53, and these electrode pads are connection electrodes 56 and 57 (56 is not shown).
To the bottom surface of the ceramic substrate via the extraction electrodes 58, 59.
(58 is not shown) is electrically drawn out.
These shapes can be easily created by ceramic lamination technology. Further, a low melting point glass G for sealing is formed by printing on the opening end portion 51, and a black (dark color) colored film H2 made of immortal ink or the like is formed on a side surface of the peripheral wall portion 52. ing. The electrode pads 54, 5
A rectangular crystal diaphragm 3 is mounted on the disk 5, and one end in the long side direction is cantilevered. Although not shown, a pair of excitation electrodes are formed on the front and back surfaces of the crystal diaphragm 3, and they are led out to the electrode pads 54 and 55, respectively, and conductively bonded by the conductive bonding material S. The electrode pads 54 and 55, the connecting electrodes 56 and 57, and the extraction electrode 5 described above.
8, 59 are formed by metallization.

The ceramic lid 6 is a high-purity alumina ceramic with a white base (for example, 96% for containing alumina).
Is formed into a flat plate shape. A low melting point glass G for sealing is printed on the sealing area 61 of the ceramic lid, and a black (dark) colored film H2 made of immortal ink or the like is formed on the upper surface of the lid. . The ceramic lid was formed to have a thickness of 0.15 mm.
For this reason, it is possible to reduce the height by 0.1 mm compared with the lid thickness of 0.25 mm in a general glass-sealed ceramic package.

Since the lid of the embodiment of the present invention is made of high-purity alumina ceramic, by making the lid to have a thickness of 0.1 mm or more and thinner than 0.25 mm,
A low profile can be realized without reducing the airtightness of the package lid. If the lid is formed to be thinner than 0.1 mm, the bending strength of the lid is reduced, the lid is warped, and the airtightness of the package as the lid is significantly reduced. On the other hand, if this lid is formed to have a thickness of 0.25 mm or more, it is not possible to achieve a low profile compared with the lid thickness of 0.25 mm in the conventional general glass-sealed ceramic package, and high purity alumina ceramic is used. No benefit.

The open end 5 of the ceramic substrate
1, the sealing area 61 of the ceramic lid is mounted in an overlapping manner, and in this state is put into a heating furnace for a predetermined time to melt the low-melting glass G, and then cooled to room temperature to cool the low-melting glass. It hardens and is hermetically sealed. The colored film may be formed after being hermetically sealed. Regarding the colored film formed on the lid, in consideration of mass productivity, a ceramic wafer on which the colored film is formed may be prepared in advance and then cut into individual lids.

In the hermetically sealed crystal unit package, identification marks M such as a manufacturer name, a product name, and a production lot number are laser-printed on the side surface of the ceramic base and the upper surface of the ceramic lid. In the third embodiment of the present invention, laser irradiation is performed with low power to burn off only the black colored film H2 formed on the side surface portion of the base body 5 and the upper surface portion of the lid 6, and the base material of the lid ( The identification mark M is formed by exposing (white). The power of the laser is 12 with respect to the normal power of 15 to 16 mA.
It is set to ˜13 mA, and may be reduced to about 70% to 90% of the normal power.

In the third embodiment, the color film is made of black, which has a different color from the white ceramic lid.
It is preferable that the color is a dark color having an excellent contrast with respect to white. There is no particular problem even if it is gray or brown. The colored film is formed only on a part of the upper surface of the lid on which the identification mark is formed and the side surface of the base body, but the colored film may be formed on the entire package.

In the above-mentioned first to third embodiments, the case where a colored film having a different color is formed on the upper surface of the ceramic lid or the side surface of the ceramic substrate and laser-printed is taken as an example. The laser marking may be formed on another plane such as the bottom surface of the ceramic substrate, or the laser marking may be formed on a plurality of these planes.

An immortal ink was used as an example of the colored film.
It may be a vapor-deposited material such as silicon oxide, or may be formed by plating or metallization. further,
An alumina ceramic film may be used as the colored film, and alumina films of different colors may be formed such that white is used for the black package substrate and black is used for the white package substrate. After laminating ceramics or laminating black ceramics on top of the white ceramics, only the upper ceramic layer may be burned down.

Further, as the holding mode of the crystal vibrating device, the one-end holding structure is taken as an example, but it can also be applied to the both-end holding structure. Furthermore, although an example of a crystal oscillator is shown as an example of the electronic component, the present invention can be applied to other piezoelectric vibrating devices such as a crystal oscillator, a crystal filter, and a SAW filter.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view showing a second embodiment of the present invention.

4 is a sectional view taken along line BB of FIG.

FIG. 5 is a perspective view showing a third embodiment of the present invention.

6 is a cross-sectional view taken along line CC of FIG.

[Explanation of symbols]

1, 5 ... Ceramic substrate 2, 4, 6 ... Ceramic lid 3 ... Crystal diaphragm (electronic element)

Claims (4)

[Claims] 1. A ceramic substrate on which an electronic element is mounted,
An electronic component package comprising a ceramic lid that hermetically seals mounted electronic elements, wherein the ceramic base or the ceramic lid is provided on the upper surface of at least one plane of the ceramic base or the ceramic lid. A colored film having a different color is formed, and the identification mark is formed by exposing the ceramic substrate or a part of the ceramic lid by irradiating a laser with low power enough to burn out only the colored film. A package for electronic parts. 2. The electronic component package according to claim 1, wherein the ceramic base and the ceramic lid are glass-sealed. 3. At least one of the ceramic substrate having the identification mark and the ceramic lid having the identification mark is made of white high-purity alumina ceramic, and a dark colored film is formed. The package for electronic parts according to claim 1, wherein 4. An identification mark is formed on an upper surface of the ceramic lid, the ceramic lid is made of white high-purity alumina ceramic, and a dark colored film is formed on the ceramic lid. The electronic component package according to claim 3, wherein the package is formed to be thinner than 0.25 mm.