TWI516423B - A method for manufacturing a cover for a hermetic seal, an electronic component storage case, and a sealing material for hermetic sealing - Google Patents

Description

Sealing material for hermetic sealing, electronic component storage box, and manufacturing method of hermetic sealing cover material

The present invention relates to a lid member for hermetic sealing, a case for housing an electronic component, and a method for producing a lid member for hermetic sealing.

In the past, there has been known an electronic component storage case in which a bonding layer made of solder or glass containing Pb is used, and a cover member and an electronic component storage member made of a ceramic material are housed according to the electronic component. The state is hermetically sealed. However, since Pb-containing solder or glass is used for the electronic component storage case, and Pb is a harmful substance, it is not preferable, and a bonding material containing no Pb is required.

In addition, when a ceramic material is used for the lid member, there is a problem that the thickness of the lid member is increased and the size of the electronic component housing case is increased. Therefore, it is required to use a metal material which can reduce the thickness of the cover material more than the ceramic material as the cover material.

Therefore, there has been proposed an electronic component storage case which uses a bonding layer made of a Pb-free Au-20Sn alloy, a cover member made of a metal material, and an electronic component storage member made of a ceramic material. Perform a hermetic seal. Since the Au-20Sn alloy has a low melting point (about 280 ° C), it can suppress deterioration of the stored electronic components due to heat. However, Au is expensive and requires an alternative material for the Au-20Sn alloy.

In view of the above, there is a known electronic component storage case which uses a non-Au-20Sn alloy but a bonding layer made of a glass material, a cover material made of a metal material, and a ceramic material. The electronic component storage member is hermetically sealed. Such an electronic component storage case is disclosed in, for example, Japanese Patent Laid-Open Publication No. 2002-26679.

In the above-mentioned Japanese Patent Publication No. 2002-26679, there is disclosed a surface mount type crystal oscillator (electronic component storage case) comprising: a crystal oscillator; and a concave portion for accommodating the crystal oscillator and formed in the concave portion a ceramic box around the frame; with a metal cover. The metal cover of the surface mount type crystal oscillator is made of a Ni-plated Fe-based alloy (Kovar) or a Fe-based alloy (426 alloy) containing 42% by mass of Ni and 6% by mass of Cr and Fe. Composition. Further, in the surface mount type crystal oscillator, since the frame portion of the ceramic case is joined to the metal cover by the low melting point glass, the crystal oscillator is hermetically sealed in the ceramic case.

However, in the surface mount type crystal oscillator disclosed in Japanese Laid-Open Patent Publication No. 2002-26679, it is considered that the metal cover is composed of a Ni-plated Fe-based alloy (Kovar) or a 426 alloy. The surface metal layer of the metal cover is not sufficiently adhered to the low melting point glass. At this time, there is a problem that the airtightness of the surface mount type crystal oscillator (ceramic case) cannot be sufficiently ensured.

In order to solve the above problems, an object of the present invention is to provide a hermetic sealing cover material and an electronic component storage which can sufficiently ensure the airtightness of an electronic component storage case by using a glass material containing no Pb. A method of manufacturing a lid member for a box and a hermetic seal.

The cover member for hermetic sealing according to the first aspect of the present invention is composed of a ceramic material and is used in an electronic component storage case including an electronic component storage member for accommodating electronic components, and includes a metal base material. a metal material containing at least Cr; a coating layer formed on the surface of the metal substrate and composed of an oxide film of Cr; and a bonding layer formed on the surface of the coating layer and made of a glass material not containing Pb The present invention is configured to bond a metal substrate on which a coating layer is formed to an electronic component storage member.

In the lid member for hermetic sealing according to the first aspect of the present invention, the coating layer formed of the oxide film of Cr formed on the surface of the metal substrate is formed on the surface of the coating layer and A bonding layer composed of a glass material not containing Pb and used for bonding a metal substrate on which a coating layer is formed and an electronic component storage member, and a Cr oxide film constituting the coating layer and a glass material constituting the bonding layer can be used. It is sufficiently dense, so that the metal substrate and the electronic component storage member can be sufficiently joined. Therefore, the glass material containing no Pb can be used, and the airtightness of the electronic component storage case can be sufficiently ensured. Moreover, by providing a metal base material containing a metal material containing at least Cr, the thickness of the hermetic sealing cover material can be further reduced as compared with the case where a ceramic material is used for the base material, so that electronic component storage can be suppressed. The size of the box is enlarged. Further, by including the metal material containing at least Cr as the metal base material, the coating layer composed of the oxide film of Cr can be easily formed on the surface of the metal base material.

In the lid member for hermetic sealing according to the first aspect of the invention, the temperature is preferably 30° C. or higher and 250° C. or less, and the thermal expansion coefficient α1 (/° C.) of the bonding layer and the thermal expansion coefficient α 2 of the metal substrate (/ °C) satisfies the relationship of -15×10 ^-7 ≦α2-α1≦5×10 ^-7 . According to this configuration, when the temperature is lowered by the temperature at the time of joining the metal base material and the bonding layer, the stress generated in the bonding layer made of the glass material can be reduced, so that the glass material can be suppressed. A case where cracks (cracks) occur in the joint layer.

In the lid member for hermetic sealing according to the first aspect of the invention, the thickness of the coating layer is preferably 0.3 μm or more. According to this configuration, since the thickness of the coating layer can be sufficiently ensured, the oxide film constituting the Cr layer of the coating layer can be surely adhered to the glass material constituting the bonding layer.

In the lid member for hermetic sealing according to the first aspect of the invention, it is preferable that the metal base material contains Ni, 3% by mass or more and 6% by mass or less of a Fe-based alloy of Cr and Fe. According to this configuration, since the metal base material is composed of a Fe-based alloy containing 3% by mass or more of Cr, a coating layer composed of a Cr oxide film can be surely formed on the surface of the metal base material. In addition, when the metal base material is made of a Fe-based alloy containing 6% by mass or less of Cr, the thermal expansion coefficient of the metal substrate due to the excessive content of Cr is increased, and the thermal expansion of the metal substrate can be suppressed. The coefficient is significantly different from the coefficient of thermal expansion of the bonding layer. Therefore, it is possible to suppress the occurrence of cracking or the like due to the difference in thermal expansion occurring in the bonding layer or the metal substrate. Moreover, since the metal substrate contains Ni, the thermal expansion coefficient of the metal substrate can be reduced, so that the thermal expansion coefficient of the metal substrate can be made closer to the bonding layer composed of the glass material having a smaller thermal expansion coefficient than the general metal material. Thermal expansion coefficient.

In this case, the metal base material is preferably a Fe-based alloy of 42% by mass of Ni, 3% by mass or more and 6% by mass or less of Cr and Fe. According to this configuration, since the metal substrate contains 42% by mass of Ni, the thermal expansion coefficient of the metal substrate can be surely reduced, so that the thermal expansion coefficient of the metal substrate can be made close to a glass material having a small thermal expansion coefficient. The coefficient of thermal expansion of the bonding layer. In addition, the metal base material is made of a Fe-based alloy containing 42% by mass of Ni and 3% by mass or more and 6% by mass or less of Cr, so that the thermal expansion coefficient α1 of the bonding layer and the metal substrate can be configured. The thermal expansion coefficient α2 does satisfy the relationship of -15 × 10 ^-7 ≦ α 2 - α 1 ≦ 5 × 10 ^-7 , and it is possible to surely suppress the occurrence of cracking in the bonding layer composed of the glass material. Moreover, the inventor of the present invention has completed the confirmation by this experiment for this point.

In the lid member for hermetic sealing according to the first aspect of the invention, it is preferable that the coating layer is formed on the surface of the metal substrate on which the bonding layer is disposed and on the surface of the metal substrate opposite to the side on which the bonding layer is disposed. . According to this configuration, unlike the case where the coating layer is formed on only one of the surfaces of the metal substrate, it is possible to prevent the bonding layer from being erroneously formed on the surface of the metal substrate on which the coating layer is not formed.

In the lid member for hermetic sealing according to the first aspect of the invention, the metal base material is preferably a first layer containing at least Cr disposed on the side of the bonding layer, and a second material containing a metal material different from the first layer. The layer of cladding material is composed of layers. According to this configuration, in comparison with the case where the metal base material is composed of only one layer, the thermal expansion coefficient of the metal base material can be easily adjusted by joining the different metal materials having different thermal expansion coefficients. Moreover, since the first layer containing at least Cr is disposed on the side of the bonding layer, the coating layer composed of the Cr oxide film can be easily formed on the surface of the metal substrate corresponding to the region where the bonding layer is formed.

In this case, it is preferable that the thermal expansion coefficient of the first layer is larger than the thermal expansion coefficient of the bonding layer, and the thermal expansion coefficient of the second layer is smaller than the thermal expansion coefficient of the bonding layer. According to this configuration, by adjusting the thickness of the first layer and the thickness of the second layer, the thermal expansion coefficient of the entire metal substrate can be made close to the thermal expansion coefficient of the bonding layer.

In the above-mentioned metal base material, the first sealing layer for the hermetic sealing material comprising at least the first layer and the second layer is preferably a metal substrate containing Ni and 3% by mass or more. A Fe-based alloy of Cr and Fe in an amount of 6 mass% or less. According to this configuration, the coating layer composed of the Cr oxide film can be surely formed on the surface of the metal substrate corresponding to the region where the bonding layer is formed. Further, since the first layer of the metal substrate is made of a Fe-based alloy containing Ni, the thermal expansion coefficient of the first layer can be made small, so that the thermal expansion coefficient of the metal substrate can be made close to the coefficient of thermal expansion. The coefficient of thermal expansion of the bonding layer formed by the glass material.

The metal base material is a hermetic sealing cover material comprising at least a first layer and a second layer of a clad material, and preferably the metal base material is composed of a clad material having the following layer: a first layer containing at least Cr on the side of the bonding layer; a second layer containing a metal material different from the first layer on the side opposite to the bonding layer of the first layer; and a first layer disposed on the second layer The layer is on the opposite side and contains at least the third layer of Cr. According to this configuration, the first layer and the third layer on the surface side of the metal substrate can be made to contain at least Cr, so that they can be on both surfaces of the metal substrate (the first layer is opposite to the second layer). A coating layer made of an oxide film of Cr is formed on each of the side surface and the surface of the third layer opposite to the second layer. Thereby, unlike the case where the coating layer is formed on only one of the surfaces of the metal substrate, it is possible to prevent the bonding layer from being erroneously formed on the surface of the metal substrate on which the coating layer is not formed.

In the above-mentioned metal substrate, the lid member for hermetic sealing comprising the first layer and the second layer and the third layer is preferably a first layer and a third layer containing Ni, 3 It is composed of Cr having a mass% or more and 6% by mass or less and a Fe-based alloy with Fe. According to this configuration, since the first layer and the third layer of the metal base material are each composed of a Fe-based alloy containing Ni, the thermal expansion coefficients of the first layer and the third layer can be made small. Thereby, the thermal expansion coefficient of the entire metal substrate can be made closer to the thermal expansion coefficient of the bonding layer composed of the glass material having a small thermal expansion coefficient.

In the first and third layers, the lid member for hermetic sealing comprising an Fe-based alloy preferably contains 42% by mass of Ni and 6% by mass of Cr, and the first layer and the third layer. The Fe alloy is composed of Fe, and the second layer is made of a Fe-based alloy containing 42% by mass of Ni and Fe. According to this configuration, the first layer, the second layer, and the third layer of the metal substrate are each composed of a Fe-based alloy containing 42% by mass of Ni, and the first layer and the second layer can be surely reduced. And the thermal expansion coefficient of the third layer. Therefore, the thermal expansion coefficient of the metal substrate can be made close to the thermal expansion coefficient of the bonding layer composed of the glass material having a small thermal expansion coefficient. Further, each of the first layer and the third layer is composed of a Fe-based alloy containing 42% by mass of Ni, 6% by mass of Cr, and Fe, and the second layer is composed of 42% by mass of Ni and Fe. A Fe-based alloy is generally used, whereby a Fe-based alloy which is easily obtained can be used, and a coating layer made of a Cr oxide film can be formed on the surface of the metal substrate corresponding to the region where the bonding layer is formed, and the metal substrate can be formed. The coefficient of thermal expansion is close to the coefficient of thermal expansion of the bonding layer composed of the glass material.

In the lid member for hermetic sealing comprising the Fe-based alloy, the total thickness of the first layer and the third layer is preferably 50% or more of the entire thickness of the metal substrate. According to this configuration, the thermal expansion coefficient α1 of the bonding layer and the thermal expansion coefficient α2 of the metal substrate can surely satisfy the relationship of -15×10 ^-7 ≦α2-α1≦5×10 ^-7 , so that it can be surely suppressed. A crack occurs in a bonding layer composed of a glass material. Moreover, the inventor of the present invention has completed the confirmation by this experiment for this point.

The electronic component storage case according to the second aspect of the present invention includes: a cover member for hermetic sealing, comprising: a metal substrate having a metal material containing at least Cr; and a coating layer formed on a surface of the metal substrate The upper layer is formed of an oxide film of Cr; the bonding layer is formed on the surface of the coating layer, and is made of a glass material not containing Pb; and the electronic component storage member is formed with a coating layer via the bonding layer. The metal substrate is joined and composed of a ceramic material for accommodating the electronic component.

In the electronic component storage case according to the second aspect of the invention, the cover member for hermetic sealing includes a coating layer formed of an oxide film of Cr formed on the surface of the metal substrate, and is formed on the coating layer. a bonding layer made of a glass material containing no Pb on the surface, and the electronic component housing member is configured to be bonded to the metal substrate on which the coating layer is formed via the bonding layer, so that the Cr oxide film constituting the coating layer can be formed. The glass substrate is sufficiently adhered to the glass material constituting the bonding layer, and the metal substrate can be sufficiently bonded to the electronic component storage member. Thereby, the glass material containing no Pb can be used, and the airtightness of the electronic component storage case can be fully ensured. Further, since the lid member for hermetic sealing contains a metal substrate having a metal material (having at least Cr), the thickness of the lid member for hermetic sealing can be reduced as compared with the case where a ceramic material is used in the substrate. Therefore, it is possible to suppress an increase in the size of the electronic component storage case. Further, by providing the metal substrate with a metal material containing at least Cr, it is possible to easily form a coating layer composed of a Cr oxide film on the surface of the metal substrate.

In the electronic component storage case according to the second aspect of the invention, it is preferable that the thermal expansion coefficient α1 (/° C.) of the bonding layer and the thermal expansion coefficient α3 of the electronic component housing member are in a temperature range of 30° C. or higher and 250° C. or lower. (/°C) satisfies the relationship of 0≦α1-α3≦10×10 ^-7 . According to this configuration, when the temperature is lowered by the temperature at the time of joining the bonding layer and the electronic component housing member, the stress generated in the bonding layer made of the glass material can be reduced, so that it can be suppressed. A crack (crack) occurs in a bonding layer composed of a glass material.

In this case, it is preferable that the thermal expansion coefficient α1 (/° C.) of the bonding layer and the thermal expansion coefficient α3 (/° C.) of the electronic component storage member satisfy 0≦α1 in a temperature range of 30° C. or higher and 250° C. or lower. Α3≦10×10 ^-7 , and the thermal expansion coefficient α1 (/° C.) of the bonding layer and the thermal expansion coefficient α2 (/° C.) of the metal substrate satisfy -15×10 ^-7 ≦α2-α1≦5×10 ^-7 Relationship. According to this configuration, since 0 ≦ α1 - α3 ≦ 10 × 10 ^-7 , no stress is applied to the electronic component housing member side of the bonding layer, or a tensile stress is slightly applied. Further, by -15 × 10 ^-7 ≦ α 2 - α 1 ≦ 5 × 10 ^-7 , it is possible to prevent stress from being applied to the metal substrate side of the bonding layer or to apply a tensile stress slightly. Therefore, even if stress is applied to the bonding layer, the bonding layer disposed between the metal substrate and the electronic component housing member is subjected to tensile stress by both the metal substrate and the electronic component housing member, and thus One of the metal base material and the electronic component storage member differs in the case where the tensile stress is applied to the bonding layer, which can suppress the occurrence of cracking of the bonding layer.

A method for producing a lid member for a hermetic seal according to a third aspect of the present invention is a cover for a hermetic seal comprising an electronic component storage case for accommodating an electronic component storage member for an electronic component. And a method for producing a material comprising: a step of oxidizing Cr of a metal substrate on a surface of a metal substrate containing a metal material containing at least Cr to form a coating layer composed of an oxide film of Cr; and On the surface, a step of forming a bonding layer composed of a glass material containing no Pb and bonding the metal substrate on which the coating layer is formed and the electronic component storage member is formed.

In the method for producing a lid member for hermetic sealing according to the third aspect of the invention, as described above, the surface of the metal substrate containing the metal material containing at least Cr is oxidized by Cr of the metal substrate. a step of forming a coating layer composed of an oxide film of Cr; forming a glass material containing no Pb on the surface of the coating layer, and forming a metal substrate and an electronic component housing structure on which the coating layer is formed In the step of joining the bonding layers of the material, the Cr oxide film constituting the coating layer and the glass material constituting the bonding layer are sufficiently adhered to each other, and the metal substrate and the electronic component storage member can be sufficiently joined. Thereby, the glass material containing no Pb can be used, and the airtightness of the electronic component storage case can be fully ensured. Moreover, by using a metal substrate containing a metal material (which contains at least Cr), the thickness of the lid member for hermetic sealing can be reduced as compared with the case of using a ceramic material in the substrate, so that electronic parts can be suppressed. The storage box is enlarged. Further, when the metal base material contains a metal material containing at least Cr, the coating layer composed of the Cr oxide film can be easily formed on the surface of the metal base material.

In the method for producing a lid member for a hermetic seal according to the third aspect of the invention, the step of forming a coating layer includes containing a Fe-based alloy containing Ni, 3% by mass or more and 6% by mass or less of Cr and Fe. A step of forming a coating layer composed of an oxide film of Cr on the surface of the metal substrate of the metal material. With such a configuration, the metal substrate is made of a Fe-based alloy containing 3% by mass or more of Cr, and a coating layer made of a Cr oxide film can be surely formed on the surface of the metal substrate. In addition, when the metal base material is made of a Fe-based alloy containing 6% by mass or less of Cr, it is possible to suppress an increase in the thermal expansion coefficient of the metal base material due to an excessive content of Cr, and a thermal expansion coefficient and a joint of the metal base material. The case where the coefficients of thermal expansion of the layers are significantly different. Thereby, it is possible to suppress the occurrence of cracks (cracks) or the like due to the difference in thermal expansion from occurring in the bonding layer or the metal substrate. Moreover, by making the metal substrate contain Ni, the thermal expansion coefficient of the metal substrate can be reduced, so that the thermal expansion coefficient of the metal substrate can be made closer to the thermal expansion coefficient of the bonding layer composed of the glass material having a thermal expansion coefficient smaller than that of the metallic material. .

In this case, a step of forming a coating layer made of a Cr oxide film is preferred, and the Cr of the metal substrate is preferentially oxidized under a humid hydrogen atmosphere at a temperature of 1000 ° C or higher and 1150 ° C or lower. Thereby, a step of forming a coating layer composed of an oxide film of Cr is preferentially formed on the surface of the metal substrate. According to this configuration, the thickness of the coating layer composed of the oxide film of Cr can be surely ensured.

In the method for producing a lid member for hermetic sealing which has a step of preferentially forming a coating layer composed of an oxide film of Cr, it is preferred to form a coating layer composed of an oxide film of Cr preferentially, and The step of setting the oxygen partial pressure to be smaller than the partial pressure of oxidation of Fe and Ni and larger than the partial pressure of the partial oxidation of Cr, and preferentially forming a coating layer composed of the oxide film of Cr. According to this configuration, it is possible to easily oxidize only Cr preferentially, so that the thickness of the coating layer composed of the oxide film of Cr can be sufficiently ensured on the surface of the metal substrate more reliably.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)

First, the structure of the lid member 1 for hermetic sealing according to the first embodiment of the present invention will be described with reference to Figs. 1 and 2 .

The hermetic sealing cover member 1 of the first embodiment is formed of a lid 10 and a glass layer 11 formed on the upper surface 10a of the lid 10 (on the Z1 side surface) as shown in Fig. 1 . The cover 10 is composed of a rectangular parallelepiped having a length L1 of about 2.4 mm in the X direction, a length L2 of about 1.9 mm in the Y direction, and a thickness t1 of about 0.1 mm in the Z direction. Moreover, the glass layer 11 is an example of the "bonding layer" of this invention.

The glass layer 11 is formed to have substantially the same width W (refer to FIG. 2) along the end portion of the upper surface 10a of the cover 10, and has a thickness t2 of about 0.05 mm in the Z direction. The glass layer 11 is formed in a frame shape along the end portion of the upper surface 10a of the lid 10 so as to correspond to the upper surface 32a (see FIG. 4) of the frame body 32 of the electronic component housing member 30 to be described later.

Further, the glass layer 11 contains a V-based low melting point glass containing no Pb composed of V ₂ O ₅ -P ₂ O ₅ -TeO-Fe ₂ O ₃ . The coefficient of thermal expansion α1 of the V-based low-melting point glass constituting the glass layer 11 is in a temperature range of about 30 ° C or more and about 250 ° C or less, and is about 70 × 10 ^-7 / ° C. Further, the V-based low melting point glass system has a glass transition point of about 285 °C. In addition, the term "glass transition point" refers to the temperature at which the thermal expansion coefficient of the V-based low-melting point glass changes rapidly. The coefficient of thermal expansion (about 140 × 10 ^-7 / ° C) in the temperature range above the glass transition point is also greater than the glass transition point. The coefficient of thermal expansion α1 (about 70 × 10 ^-7 / ° C) in the temperature range. Further, the sealing temperature of the V-based low-melting point glass constituting the glass layer 11 is set to be about 370 ° C or more and about 400 ° C or less.

Further, the V-based low-melting point glass constituting the glass layer 11 is configured to suppress entry of water molecules into the crystal structure. Thereby, the glass layer 11 has moisture resistance (water resistance).

As shown in FIG. 2, the cover 10 is composed of a metal base material 12 and an oxide film layer 13 formed to surround the entire surface of the metal base material 12. A glass layer 11 is formed on the upper surface of the oxide film layer 13. Further, the metal base material 12 is made of a Fe-based alloy (42Ni-(2-6)Cr-Fe alloy) containing about 42% by mass of Ni, about 2% by mass or more and about 6% by mass or less of Cr and Fe. Composition. Further, the metal base material 12 is preferably made of a Fe-based alloy (42Ni-(3-6)Cr-Fe alloy) containing about 3% by mass or more and about 6% by mass or less of Cr. Moreover, the oxide film layer 13 is an example of the "coating layer" of the present invention.

In the first embodiment, it is preferable that the Fe-based alloy constituting the metal base material 12 has a thermal expansion coefficient α2 of about 55 × 10 ^-7 /° C or more in a temperature range of about 30 ° C or more and about 250 ° C or less. And about 75 × 10 ^-7 / ° C or less. That is, it is preferable that the thermal expansion coefficient α1 of the glass layer 11 and the thermal expansion coefficient α2 of the metal substrate 12 satisfy -15×10 ^-7 ≦α2-α1≦5 in a temperature range of about 30 ° C or more and about 250 ° C or less. ×10 ^-7 relationship. As a result, in the temperature range of about 30 ° C or more and about 250 ° C or less, the glass layer 11 and the metal base material 12 are less likely to cause stress due to the difference in thermal expansion.

In the first embodiment, the oxide film layer 13 is mainly composed of a film of Cr ₂ O ₃ and has a thickness t3 of about 0.3 μm or more and about 1.2 μm or less in the Z direction. Further, the oxide film layer 13 is formed by oxidizing Cr contained in the Fe-based alloy of the metal base material 12 on the surface of the metal base material 12.

Next, the structure of the electronic component storage case 100 used for the hermetic sealing cover member 1 according to the first embodiment of the present invention will be described with reference to FIG. 3 and FIG.

As shown in FIG. 3 and FIG. 4, the electronic component storage case 100 of the first embodiment has the electronic component storage member 30 in which the crystal oscillator 20 (see FIG. 4) is housed, and the gas-tight sealing cover member. The structure in which the glass layer 11 of 1 is sealed. At this time, the lid member 1 for hermetic sealing is disposed such that the upper surface 10a of the lid 10 of the lid member for hermetic sealing is the lower side (Z3 side). Further, the crystal oscillator 20 is an example of the "electronic component" of the present invention.

The electronic component storage member 30 is made of Al ₂ O ₃ which is a ceramic material, and has a length L3 of about 2.5 mm in the X direction and a length L4 of about 2.0 mm in the Y direction when viewed in plan. Moreover, since the electronic component storage member 30 is made of a ceramic material, it has insulation properties. Further, in a temperature range of about 30 ° C or more and about 250 ° C or less, the thermal expansion coefficient α3 of Al ₂ O ₃ constituting the electronic component housing member 30 is about 65 × 10 ^-7 /°C. That is, in the temperature range of about 30 ° C or more and about 250 ° C or less, the thermal expansion coefficient α1 (about 70 × 10 ^-7 / ° C) of the glass layer 11 and the thermal expansion coefficient α3 of the electronic component storage member 30 satisfy 0. ≦α1-α3 (= about 5 × 10 ^-7 ) ≦ 10 × 10 ^-7 relationship. As a result, in the temperature range of about 30 ° C or more and about 250 ° C or less, the glass layer 11 and the electronic component storage member 30 are less likely to cause stress due to the difference in thermal expansion.

Further, as shown in FIG. 4, the electronic component housing member 30 includes a bottom portion 31 on the Z3 side and a frame portion 32 formed to extend in the Z4 direction from the periphery of the upper surface 31 (the surface on the Z4 side). Further, in the electronic component housing member 30, the recessed portion 33 is formed by being surrounded by the bottom portion 31 and the frame body 32. The concave portion 33 is formed to have an opening portion on the upper side (Z4 side), and the crystal oscillator 20 is placed on the upper surface (the surface on the Z4 side) of the bottom portion 31 of the concave portion 33 via the bump 40. In the recess 33.

Moreover, the lid 10 of the lid member 1 for hermetic sealing is bonded to the upper surface 32a of the frame 32 of the electronic component housing member 30 via the glass layer 11. Specifically, the glass layer 11 of the lid member 1 for sealing the airtight seal is cooled in a state of being placed on the upper surface 32a of the frame 32, and the lid 10 of the hermetic sealing lid member 1 and the electronic component are housed. The members 30 are joined. Thereby, the electronic component storage case 100 is sealed. Here, the concave portion 33 of the electronic component storage member 30 in which the crystal oscillator 20 is housed, the cover 10 for the hermetic sealing cover member 1, and the space formed by the glass layer 11 are configured to be airtight. (slightly vacuumed). Thereby, it is possible to suppress the change (deterioration) of the vibration characteristics and the like in the crystal oscillator 20.

Further, the thermal expansion coefficient α2 of the metal base material 12 is defined by the relationship between the thermal expansion coefficient α3 of the electronic component housing member 30 and the thermal expansion coefficient α1 of the glass layer 11. In other words, since the thermal expansion coefficient α1 of the glass layer 11 is equal to or higher than the thermal expansion coefficient α3 of the electronic component housing member 30, no stress is applied to the electronic component housing member 30 side of the glass layer 11, or a tensile stress is slightly applied. Here, the metal substrate 12 is configured such that the thermal expansion coefficient α2 of the metal substrate 12 satisfies the relationship of -15 × 10 ^-7 ≦ α 2 - α 1 ≦ 5 × 10 ^-7 , and can be formed as a cover of the glass layer 11 . The 10 side does not apply stress or slightly exerts tensile stress. As a result, even when stress is applied to the glass layer 11, tensile stress is applied to both the lid 10 and the electronic component storage member 30 by the glass layer 11 disposed between the lid 10 and the electronic component housing member 30. Therefore, even the glass layer 11 composed of the V-based low-melting glass which is likely to be cracked (cracked) with tensile stress can be prevented from being broken.

Next, a manufacturing process of the electronic component housing case 100 according to the first embodiment will be described with reference to Figs. 1 to 6 .

First, the metal base material 12 composed of the 42Ni-(2-6)Cr-Fe alloy shown in Fig. 1 and Fig. 2 was prepared. Then, as shown in FIG. 5, the metal substrate 12 is subjected to oxidation treatment for about 30 minutes under a humid hydrogen atmosphere having a dew point of about 30 ° C and a temperature of about 900 ° C or more and about 1150 ° C or less. Priority oxidation). Further, the temperature condition is preferably about 1000 ° C or more and about 1150 ° C or less. At this time, since the dew point of hydrogen is about 30 ° C, the partial pressure of oxygen in the humidified hydrogen atmosphere is smaller than the partial pressure at which Fe and Ni can be oxidized, and on the other hand, is greater than the partial pressure at which Cr can be oxidized. Thereby, only Cr can be preferentially oxidized on the surface of the metal substrate 12 without oxidizing Fe and Ni. As a result, the oxide film layer 13 mainly composed of Cr ₂ O ₃ and having a thickness t3 (see FIG. 2 ) of about 0.3 μm or more and about 1.2 μm or less is formed on the entire surface of the metal base material 12 .

Then, as shown in FIGS. 1 and 2, a paste of V-based low-melting point glass containing no Pb is applied on the upper surface of the oxide film layer 13 along the upper surface of the oxide film layer 13 (the upper surface 10a of the lid 10). Thereafter, firing is carried out at a temperature of about 410 ° C to remove the binder in the paste of the V-based low melting point glass. Thereby, the hermetic sealing cover material 1 in which the glass layer 11 was formed along the edge part of the upper surface 10a of the cover 10 was manufactured.

Moreover, as shown in FIG. 4, the electronic component storage member 30 in which the crystal oscillator 20 is accommodated in the recessed part 33 is prepared. Then, the hermetic sealing cover member 1 is placed on the electronic component storage member 30 so that the glass layer 11 of the hermetic sealing cover member 1 is positioned on the upper surface 32a of the casing 32 of the electronic component housing member 30. Then, as shown in FIG. 6, the lid member 1 for hermetic sealing is placed in the vacuum furnace 2 in a state of being placed in the electronic component housing member 30, and is in a vacuum state at a temperature of about 370 ° C or more and about 400 ° C or less. Under the condition, the glass layer 11 is melted.

After that, the hermetic sealing cover member 1 and the electronic component storage member 30 are cooled, and as shown in FIG. 4, the cover 10 of the hermetic sealing cover member 1 is joined to the electronic component storage via the glass layer 11. The frame 32 of the member 30 has an upper surface 32a. Here, the glass transition point of the V-based low melting point glass constituting the glass layer 11 is obtained from the bonding temperature (about 300 ° C) at which the lid 10 of the hermetic sealing lid member 1 and the electronic component housing member 30 are joined ( In the temperature range up to about 285 ° C) (temperature range above the glass transition point), the thermal expansion coefficient α2 (about 55 × 10 ^-7 / ° C or more and about 75 × 10 ^-7 / ° C or less) compared to the metal substrate 12 And the thermal expansion coefficient α3 (about 65 × 10 ^-7 / ° C) of the electronic component storage member 30, and the thermal expansion coefficient (about 140 × 10 ^-7 / ° C) of the glass layer 11 is large. However, since the glass layer 11 has fluidity in the temperature range above the glass transition point, the cover 10 (metal substrate 12), the glass layer 11 and the electronic component storage member 30 do not cause a difference in thermal expansion coefficient. Stress. Further, in the temperature range below the glass transition point (temperature range of about 30 ° C or more and about 250 ° C or less), the glass layer 11 and the lid 10 and the electronic component storage member 30 are configured to be less likely to be caused by the difference in thermal expansion. After the stress, the stress accumulated in the cover 10, the glass layer 11, and the electronic component housing member 30 is small.

In addition, since the recessed portion 33 of the electronic component housing member 30 in which the crystal oscillator 20 is housed, the lid 10 for the hermetic sealing lid member 1, and the glass layer 11 are formed by bonding (sealing) in a vacuum state. The space becomes a state with sufficient airtightness (slightly vacuumed state). Moreover, in order to seal the space formed by the recessed part 33 and the cover 10 and the glass layer 11 in a state of being more airtight, it is preferable to melt and seal the glass layer 11 under the temperature conditions of about 380 degreeC or more. Further, by sealing the glass layer 11 at a temperature of about 400 ° C or lower, the effect of heat on the crystal oscillator 20 during sealing can be reduced. In this manner, the hermetically sealed electronic component storage case 100 shown in FIG. 3 was produced.

In the first embodiment, the hermetic sealing cover material 1 includes the oxide film layer 13 mainly composed of a Cr ₂ O ₃ film formed on the surface of the metal base material 12, and the oxide film layer 13 formed thereon. a glass layer 11 having a Pb-free V-based low-melting point glass composed of V ₂ O ₅ -P ₂ O ₅ -TeO-Fe ₂ O ₃ on the surface, whereby Cr constituting the oxide film layer 13 can be formed. _{Since the 2} O ₃ film is sufficiently adhered to the V-based low-melting glass constituting the glass layer 11, the metal base material 12 and the electronic component storage member 30 can be sufficiently joined. Thereby, the V-type low-melting point glass containing no Pb can be used, and the airtightness of the electronic component storage case 100 can be sufficiently ensured. Further, when the lid member 1 for hermetic sealing is provided with the metal base material 12 composed of a 42Ni-(2-6)Cr-Fe alloy, it can be reduced as compared with the case where a ceramic material is used for the base material. Since the thickness t1 of the lid member 1 for small airtight sealing is small, the size of the electronic component housing case 100 can be suppressed from increasing. Further, by forming the metal base material 12 from a 42Ni-(2-6)Cr-Fe alloy, the oxide film layer 13 made of Cr ₂ O ₃ can be easily formed on the surface of the metal base material 12.

Further, in the first embodiment, as described above, the thermal expansion coefficient α1 of the glass layer 11 and the thermal expansion coefficient α2 of the metal substrate 12 satisfy -15 × in a temperature range of about 30 ° C or more and about 250 ° C or less. 10 ^-7 ≦α2-α1 ≦ 5 × 10 ^-7 , so when the temperature at the time of joining the metal base material 12 and the glass layer 11 is lowered, the glass formed by the V-based low melting point glass can be reduced. The stress generated in the glass layer 11 can suppress cracking (cracking) of the glass layer 11 composed of the V-based low-melting glass. Further, by configuring the thermal expansion coefficient α1 of the glass layer 11 and the thermal expansion coefficient α2 of the metal base material 12 to satisfy the relationship of -15 × 10 ^-7 ≦ α 2 - α1, it is possible to suppress the pulling of the thermal expansion coefficient more easily than the compressive stress. The tensile stress is broken and the tensile stress applied to the V-based low-melting glass constituting the glass layer 11 is excessively increased.

In the first embodiment, when the thickness t3 of the oxide film layer 13 is about 0.3 μm or more and about 1.2 μm or less, the thickness t3 of the oxide film layer 13 can be sufficiently ensured, so that oxidation can be formed. The Cr ₂ O ₃ film of the film layer 13 is surely adhered to the V-based low-melting glass constituting the glass layer 11.

Further, in the first embodiment, as described above, by configuring the metal base material 12 to be composed of a 42Ni-(2-6)Cr-Fe alloy, the entire surface of the metal base material 12 can be surely An oxide film layer 13 composed of a Cr ₂ O ₃ film is formed. Further, it is possible to suppress a case where the thermal expansion coefficient α2 of the metal base material 12 due to the excessive Cr content is large, and the thermal expansion coefficient α2 of the metal base material 12 is significantly different from the thermal expansion coefficient α1 of the glass layer 11. Thereby, it is possible to suppress cracking or the like due to a difference in thermal expansion on the glass layer 11 or the metal substrate 12. Moreover, by including 42% by mass of Ni in the metal base material 12, the thermal expansion coefficient α2 of the metal base material 12 can be made small. Thereby, the thermal expansion coefficient α2 of the metal base material 12 can be made closer to the thermal expansion coefficient α1 of the glass layer 11 composed of the V-based low-melting point glass whose thermal expansion coefficient is generally smaller than that of the metal material. As a result, it is possible to further suppress the occurrence of cracking or the like due to the difference in thermal expansion of the glass layer 11.

Further, in the first embodiment, as described above, by configuring the metal base material 12 to be composed of a 42Ni-(3-6)Cr-Fe alloy, the thermal expansion coefficient α1 of the glass layer 11 and the metal substrate can be made. The coefficient of thermal expansion α2 of 12 does satisfy the relationship of -15 × 10 ^-7 ≦ α 2 - α 1 ≦ 5 × 10 ^-7 , so that it is possible to surely suppress the occurrence of cracking of the glass layer 11 composed of the V-based low-melting glass.

Further, in the first embodiment, as described above, by forming the oxide film layer 13 so as to surround the entire surface of the metal substrate 12, an oxide film layer is formed on only one of the surfaces of the metal substrate 12. In the case of 13, it is possible to prevent the glass layer 11 from being erroneously formed on the surface of the metal substrate 12 on which the oxide film layer 13 is not formed. Further, unlike the case where the oxide film layer 13 is formed only in one portion of the metal base material 12, it is not necessary to cover one portion of the metal base material 12 when forming the oxide film layer 13. Therefore, the oxide film layer 13 can be easily formed. Further, since the oxide film layer 13 composed of the corrosion-resistant Cr ₂ O ₃ is formed so as to surround the entire surface of the metal base material 12, the corrosion resistance of the metal base material 12 can be improved.

Further, in the first embodiment, as described above, the thermal expansion coefficient α1 (about 70 × 10 ^-7 / ° C) of the glass layer 11 and the electron are set in a temperature range of about 30 ° C or more and about 250 ° C or less. The thermal expansion coefficient α3 (about 65×10 ^-7 /° C.) of the part storage member 30 satisfies the relationship of 0≦α1−α3 (=about 5×10 ^-7 )≦10×10 ^-7 , and the glass layer 11 is When the temperature is lowered at a bonding temperature (about 300 ° C) when the electronic component storage member 30 is joined, the stress generated in the glass layer 11 composed of the V-based low-melting glass can be reduced, so that it can be suppressed by V. The glass layer 11 composed of the low melting point glass is broken.

Further, in the first embodiment, as described above, the thermal expansion coefficient α1 (about 70 × 10 ^-7 / ° C) of the glass layer 11 and the electronic component storage are set in a temperature range of about 30 ° C or more and about 250 ° C or less. The thermal expansion coefficient α3 (about 65×10 ^-7 /° C.) of the member 30 satisfies 0≦α1−α3 (=about 5×10 ^-7 )≦10×10 ^-7 , and the thermal expansion coefficient α1 of the glass layer 11 and the metal base The thermal expansion coefficient α2 of the material 12 (about 55 × 10 ^-7 /° C. or more and about 75 × 10 ^-7 /° C or less) is -15 × 10 ^-7 ≦ α 2 - α 1 ≦ 5 × 10 ^-7 . Therefore, even when stress is applied to the glass layer 11, the glass layer 11 disposed between the metal base material 12 and the electronic component storage member 30 is applied by both the metal base material 12 and the electronic component storage member 30. Since the tensile stress is different from the case where the tensile stress is applied to the glass layer 11 only by one of the metal base material 12 and the electronic component storage member 30, cracking of the glass layer 11 can be suppressed.

Further, in the first embodiment, as described above, the metal base material 12 has a dew point of about 30 ° C, which is smaller than a partial pressure which can oxidize Fe and Ni, and is larger than a partial pressure of humidified hydrogen which can oxidize Cr. In the environment, when the oxidation treatment (pre-oxidation of Cr) is performed for about 30 minutes at a temperature of about 1000 ° C or more and about 1150 ° C or less, it is possible to easily oxidize only Cr preferentially, so that the metal substrate 12 can be more reliably obtained. The thickness of the oxide film layer 13 composed of the Cr ₂ O ₃ film is sufficiently ensured on the surface.

(Example)

Next, the measurement of the thermal expansion coefficient and the measurement of the wettability performed in order to confirm the effect of the first embodiment will be described with reference to Figs. 2 and 7 to 17 .

(Measurement of thermal expansion coefficient)

The thermal expansion coefficient measured as described below is used in the Fe-based alloy containing 42% by mass of Ni and Fe as Examples 1 to 5 corresponding to the metal base material 12 of the first embodiment as shown in Fig. 7 . Fe-based alloys having different Cr contents.

Specifically, as Example 1, a Fe-based alloy (42Ni-2Cr-Fe alloy) containing 2% by mass of Cr was used. Further, as Example 2, a Fe-based alloy (42Ni-3Cr-Fe alloy) containing 3% by mass of Cr was used. Further, as Example 3, a Fe-based alloy (42Ni-4Cr-Fe alloy) containing 4% by mass of Cr was used. Further, as Example 4, an Fe-based alloy (42Ni-5Cr-Fe alloy) containing 5% by mass of Cr was used. Further, as Example 5, an Fe-based alloy (42Ni-6Cr-Fe alloy) containing 6 mass% of Cr was used.

On the other hand, as Comparative Example 1 with respect to Examples 1 to 5, an Fe-based alloy (42Ni-Fe alloy) containing 42% by mass of Ni and Fe and containing no Cr was used.

In addition, as a reference example 1 of the metal substrate of the first embodiment, V ₂ O ₅ -P ₂ O ₅ -TeO-Fe ₂ O ₃ constituting the glass layer 11 of the first embodiment is used. V-based low melting point glass without Pb. Further, as Reference Example 2, Al ₂ O ₃ constituting the electronic component housing member 30 of the first embodiment described above was used.

Then, the elongation of each member was measured by changing the temperatures of the members of Examples 1 to 5, Comparative Example 1, and Reference Examples 1 and 2. In addition, the elongation means the amount of elongation of the member at any temperature (the amount of the reference length when the temperature is reduced from the temperature at any temperature (30 ° C)), and the reference length is divided by the room temperature. value. Then, the slope of a straight line connecting the elongation at room temperature and the elongation at 250 ° C was determined as a coefficient of thermal expansion in a temperature range of 30 ° C or more and 250 ° C or less.

As shown in Fig. 8, as an experimental result of the elongation measurement, the elongation (thermal expansion coefficient) was increased by adding Cr to the 42Ni-Fe alloy (Comparative Example 1). Further, the elongation can be increased by increasing the amount of Cr added.

Further, in the temperature range up to the glass transition point (285 ° C) of the V-based low melting point glass, the elongation of the 42Ni-Fe alloy of Comparative Example 1 was considerably smaller than that of the V-based low melting point glass (Reference Example 1). rate. Further, the elongation of the 42Ni-2Cr-Fe alloy of Example 1 was also smaller than that of the V-based low melting point glass (Reference Example 1). On the other hand, the elongation of the 42Ni-(3-6)Cr-Fe alloy of Examples 2 to 5 is a value similar to the elongation of the V-based low melting point glass (Reference Example 1).

Further, as shown in FIG. 7 and FIG. 9, the coefficient of thermal expansion is in a temperature range of 30° C. or more and 250° C. or less, and the coefficient of thermal expansion α1 of the V-based low-melting point glass (Reference Example 1) is 72×10 ^{− 7} / ° C, Al ₂ O ₃ (Reference Example 2) has a coefficient of thermal expansion α3 of 65 × 10 ^-7 / ° C. As a result, it was found that the thermal expansion coefficient α1 of the V-based low melting point glass (Reference Example 1) and the thermal expansion coefficient α3 of Al ₂ O ₃ (Reference Example 2) satisfies 0≦α1−α3 (=7×10 ^-7 )≦10× 10 ^-7 relationship.

Further, in the temperature range of 30 ° C or more and 250 ° C or less, the thermal expansion coefficient α2 of the 42Ni-Fe alloy of Comparative Example 1 was 40 × 10 ^-7 / ° C, and it was found that the glass was lower than that of the V-based low melting point glass (Reference Example 1) The thermal expansion coefficient α1 (72 × 10 ^-7 / ° C) is only 32 × 10 ^-7 / ° C. In other words, when the metal base material of Comparative Example 1 composed of the 42Ni-Fe alloy and the V-based low-melting point glass are joined at a sealing temperature (about 370 ° C or higher and about 400 ° C or lower), the difference in thermal expansion coefficient ( Since α2-α1) is large (-32×10 ^-7 /°C), it is considered that cracking (cracking) is likely to occur in the glass layer composed of the V-based low-melting glass at the time of cooling.

In addition, in the temperature range of 30 ° C or more and 250 ° C or less, the thermal expansion coefficient α2 of the 42Ni-2Cr-Fe alloy of Example 1 is 56×10 ^-7 /° C., and it is found that the phase is lower than that of the V-based low melting point glass (Reference example) 1) The thermal expansion coefficient α1 (72 × 10 ^-7 / ° C) is only 16 × 10 ^-7 / ° C. That is, when the metal substrate of Example 1 composed of the 42Ni-2Cr-Fe alloy and the V-based low-melting glass are joined at a sealing temperature, the difference in thermal expansion coefficient is large to some extent (-16×10 ^{- 7} / ° C), it is considered that there is a possibility that cracking occurs in the glass layer composed of V-based low melting point glass during cooling.

On the other hand, in the temperature range of 30 ° C or more and 250 ° C or less, the thermal expansion coefficient α2 of the 42Ni-(3-6)Cr-Fe alloy of Examples 2 to 5 is 62 × 10 ^-7 /° C. or more and 74 × Below 10 ^-7 /°C, the thermal expansion coefficient α1 (72×10 ^-7 /°C) of the V-based low melting point glass (Reference Example 1) satisfies -10×10 ^-7 ≦α2-α1≦2×10 ^-7 relationship. That is, when the metal substrate of Examples 2 to 5 composed of the 42Ni-(3~6)Cr-Fe alloy and the V-based low-melting point glass are joined at a sealing temperature, since there is no difference in thermal expansion coefficient, Therefore, it is considered that it is possible to suppress the occurrence of cracking in the glass layer composed of the V-based low-melting glass at the time of cooling. As a result, it is considered that a 42Ni-(3-6)Cr-Fe alloy is suitably used as the metal substrate.

(wetness measurement)

In the wettability measurement described below, 42Ni-4Cr-Fe alloy was used as Examples 6 to 9 corresponding to the metal base material 12 of the first embodiment, and 42Ni-6Cr-Fe alloy was used as Examples 10 to 13. Further, in Examples 6 to 9, the temperature conditions at which Cr was preferentially oxidized were different, and in Examples 10 to 13, the temperature conditions at which Cr was preferentially oxidized were different. Further, the preferential oxidation of Cr was carried out for 30 minutes in a humidified hydrogen atmosphere having a dew point of 30 °C.

Specifically, as shown in FIGS. 10 and 11, in Examples 6 and 10, Cr preferential oxidation was performed at a temperature of 900 °C. Further, as Examples 7 and 11, Cr preferential oxidation was carried out under the conditions of a temperature of 1000 °C. Further, as Examples 8 and 12, Cr preferential oxidation was carried out at a temperature of 1,100 °C. Further, as Examples 9 and 13, Cr preferential oxidation was carried out at a temperature of 1,150 °C.

Then, the thickness t3 of the oxide film layer composed of Cr ₂ O ₃ formed on the surface of the 42Ni-4(6)Cr-Fe alloy of Examples 6 to 13 was measured (see Fig. 2).

Further, as shown in FIG. 12, a paste of a V-based low melting point glass is coated on the surface of the cover 110 composed of the metal base material 112 and the oxide film layer 113 of Examples 6, 8 to 10, 12 and 13. . Similarly, a paste 114 of a V-based low melting point glass was coated on the surface of the lid 110 made of Al ₂ O ₃ (Reference Example 2). At this time, the paste 114 having a different width W is applied to each of the three places on the surface of the cover 110. Specifically, a paste 114a having a width W1 of 290 μm, a paste 114b having a width W2 of 400 μm, and a paste 114c having a width W3 of 460 μm were applied to the surface of the lid 110. At this time, the thickness t4 of the pastes 114a, 114b, and 114c was applied to 80 μm.

Then, the binder in the pastes 114a, 114b, and 114c is removed by firing at a temperature of 410 °C. Thereby, as shown in FIG. 13, the pastes 114a, 114b, and 114c (refer FIG. 12) become the glass layers 111a, 111b, and 111c, respectively. Thereafter, the width W1a and the thickness t4a of the glass layer 111a, the width W2a and the thickness t4b of the glass layer 111b, the width W3a of the glass layer 111c, and the thickness t4c were measured. Then, the rate of change of the width and thickness of the glass layers 111a (111b and 111c) with respect to the width and thickness of the pastes 114a (114b and 114c) is determined. At this time, in the case where the width (thickness) of the glass layer 111 is larger than the width (thickness) of the paste 114, the rate of change is set to a positive value, and the width (thickness) of the glass layer 111 is smaller than the width (thickness) of the paste 114. In the case of the rate of change, the rate of change is set to a negative value.

As shown in FIG. 10, in the 42Ni-4Cr-Fe alloy, the thickness t3 of the oxide film layer in Example 6 (900 ° C) was less than 0.1 μm. That is, it is considered that the oxide film did not form a sufficient thickness in Example 6 (900 ° C). On the other hand, in Examples 7 to 9 (1000 ° C, 1100 ° C, 1150 ° C), the thickness t3 of the oxide film layer was 0.3 μm or more. Further, as shown in Fig. 11, in the 42Ni-6Cr-Fe alloy, in any of Examples 10 to 13 (900 ° C, 1000 ° C, 1100 ° C, 1150 ° C), the thickness t3 of the oxide film layer was 0.3. More than μm.

Further, Example 8 (4Cr) and Example 10 (6Cr) having a temperature condition of 900 ° C, Example 7 (4Cr) having a temperature condition of 1000 ° C, and Example 11 (6Cr), and Example 8 of a temperature condition of 1100 ° C In any of (4Cr) and Example 12 (6Cr), and in Example 9 (4Cr) and Example 13 (6Cr) having a temperature condition of 1150 ° C, Examples 10 to 13 using 42Ni-6Cr-Fe alloy were used. The thickness t3 of the oxide film layer is respectively larger than the thickness t3 of the oxide film layers of Examples 6 to 9 using the 42Ni-4Cr-Fe alloy. Thereby, it was found that the thickness t3 of the oxide film layer can be increased by increasing the Cr content in the case where the temperature conditions are the same.

Further, as shown in Figs. 14 and 16, it was found that the rate of change in the width in Examples 6 and 10 (900 °C) was reduced by -40% in all of the glass layers 111a, 111b, and 111c. Further, as shown in Figs. 15 and 17, the rate of change in thickness in Examples 6 and 10 was 0% or more in addition to the thickness (-2%) of the glass layer 111a of Example 6. It is considered that in Examples 6 and 10, the oxide film layer was insufficient or not completely formed, so that the wettability was low, and the V-based low-melting point glass and the oxide film layer were not sufficiently adhered. Therefore, it can be considered that many portions of the glass layer 111 which expands in the width direction are swelled in the thickness direction.

On the other hand, as shown in FIG. 14 and FIG. 16, the rate of change in width in Examples 8 and 12 (1100 ° C), Examples 9 and 13 (1150 ° C), and Reference Example 2 (Al ₂ O ₃ ), It is -30% or more in all of the glass layers 111a, 111b, and 111c. Further, as shown in FIGS. 15 and 17, the rate of change of the thicknesses in Examples 8 and 12, Examples 9 and 13, and Reference Example 2 is reduced by -10 in all of the glass layers 111a, 111b, and 111c. %. As a result, in Examples 8 and 12 and Examples 9 and 13, since the oxide film layer was sufficiently formed, it was considered that the wettability was high, and the V-based low-melting point glass and the oxide film layer were sufficiently adhered. Therefore, it is considered that the portion of the glass layer 111 that spreads in the width direction is prevented from moving in the thickness direction without being bulged in the thickness direction, and is reduced in the volume portion, the width direction, and the thickness direction of the binder.

In other words, it has been found that the preferential oxidation of Cr in the temperature range of 1000 ° C or higher is preferable because the V-based low-melting point glass and the oxide film layer are sufficiently adhered to each other. On the other hand, in the case where Cr is preferentially oxidized in a temperature range of more than 1,150 ° C, since a device having high heat resistance is required, it is considered that Cr preferential oxidation is preferably carried out in a temperature range of from 1000 ° C to 1150 ° C.

In addition, compared with Examples 8 and 12 (1100 ° C), the reduction rates of the width change rate and the thickness change rate of Examples 9 and 13 (1150 ° C) were less overall, and therefore it was considered to be better at 1150. The preferential oxidation of Cr is carried out under the temperature condition of °C.

(Second embodiment)

Next, a second embodiment of the present invention will be described with reference to Fig. 18 . The lid member 201 for hermetic sealing according to the second embodiment is different from the above-described first embodiment, and the metal base member 212 is composed of a three-layer clad material.

In the lid member 201 for a hermetic seal according to the second embodiment of the present invention, the metal base material 212 of the lid 210 is placed on the first layer 212a of the glass layer 11 side (Z1 side) as shown in FIG. The second layer 212b disposed on the Z2 side of the first layer 212a (opposite to the glass layer 11) is joined to the third layer 212c disposed on the Z2 side of the second layer 212b (opposite to the glass layer 11). That is, it consists of a so-called three-layer cladding material. Further, the first layer 212a and the third layer 212c are each composed of a general Fe-based alloy (42Ni-6Cr-Fe alloy) containing about 42% by mass of Ni, about 6% by mass of Cr, and Fe. Further, the second layer 212b is composed of a general Fe-based alloy (42Ni-Fe alloy) containing about 42% by mass of Ni and Fe.

Further, the 42Ni-6Cr-Fe alloy constituting the first layer 212a and the third layer 212c has a thermal expansion coefficient α4 of about 75 × 10 ^-7 /°C. Further, the thermal expansion coefficient α5 of the 42Ni-Fe alloy constituting the second layer 212b is set to be about 40 × 10 ^-7 / °C. That is, the thermal expansion coefficient α4 (about 75×10 ^-7 /° C.) of the first layer 212a and the third layer 212c is larger than the thermal expansion coefficient α1 of the glass layer 11 (about 70×10 ^-7 /° C.), and The thermal expansion coefficient α5 (about 40 × 10 ^-7 / ° C) of the second layer 212b is smaller than the thermal expansion coefficient α1 of the glass layer 11.

Here, in the second embodiment, the total thickness (the thickness of the lid 210) t1 of the first layer 212a, the second layer 212b, and the third layer 212c is about 0.1 mm. Further, the first layer 212a and the third layer 212c have the same thickness t5 in the Z direction, and the second layer 212b has a thickness t6 in the Z direction. Here, the thickness t5 is preferably about 50% or more of the thickness t6. That is, it is preferable that the thickness (2 × t5) of the first layer 212a and the third layer 212c is about 50% or more (about 0.05 mm or more) of the thickness t1 (= 2 × t5 + t6) of the lid 210. As a result, in the temperature range of about 30 ° C or more and about 250 ° C or less, the thermal expansion coefficient α2 of the clad material constituting the metal base material 212 is about 55 × 10 ^-7 /° C. or more and about 75 × 10 ^-7 /° C. the following. That is, in the temperature range of about 30 ° C or more and about 250 ° C or less, the thermal expansion coefficient α1 (about 70 × 10 ^-7 / ° C) of the V-based low-melting glass constituting the glass layer 11 and the constituent metal substrate 212 The coefficient of thermal expansion α2 of the cladding material satisfies the relationship of -15 × 10 ^-7 ≦ α 2 - α 1 ≦ 5 × 10 ^-7 .

Further, on the surface and the side surface on the Z1 side of the first layer 212a, an oxide film layer 213a mainly composed of Cr ₂ O ₃ is formed, and on the surface and the side surface on the Z2 side of the third layer 212c, mainly formed of Cr An oxide film layer 213b composed of ₂ O ₃ . The oxide film layers 213a and 213b are such that the Cr contained in the 42Ni-6Cr-Fe alloy of the first layer 212a and the third layer 212c is on the Z1 side surface and the side surface of the first layer 212a, and the third layer 212c. The surface and the side surface on the Z2 side are formed by oxidation. Further, the other configuration of the second embodiment is the same as that of the first embodiment.

Next, a manufacturing process of the hermetic sealing cover member 201 according to the second embodiment of the present invention will be described with reference to FIG.

First, a plate material (not shown) made of a 42Ni-Fe alloy having a predetermined thickness is prepared. Further, two sheets each having a thickness of about 50% or more of the thickness of the sheet material composed of the 42Ni-Fe alloy and having a thickness of about 42% by weight of the 42Ni-Cr alloy were prepared. Then, the plate composed of the 42Ni-6Cr-Fe alloy is held in a state of a plate composed of the 42Ni-Fe alloy, and the plate composed of the 42Ni-Fe alloy and the 42Ni-6Cr-Fe alloy are used. The pair of sheets of the sheet material are joined in a state where a predetermined pressure is applied. Thereby, as shown in FIG. 18, the first layer 212a composed of the 42Ni-6Cr-Fe alloy, the second layer 212b composed of the 42Ni-Fe alloy, and the 42Ni-6Cr-Fe alloy are formed. The third layer 212c is a three-layer clad material joined in a state of being sequentially laminated. At this time, the thickness t5 of the first layer 212a and the third layer 212c is about 50% or more of the thickness t6 of the second layer 212b. Thereafter, the metal substrate 212 is formed by cutting the cladding material into a predetermined shape.

Thereafter, Cr is preferentially oxidized under the same conditions as in the above-described first embodiment, and an oxide film layer 213a mainly composed of Cr ₂ O ₃ is formed on the surface and the side surface on the Z1 side of the first layer 212a. The surface and the side surface on the Z2 side of the third layer 212c form an oxide film layer 213b mainly composed of Cr ₂ O ₃ . Further, the other manufacturing process of the second embodiment of the present invention is the same as that of the first embodiment.

In the second embodiment, the hermetic sealing cover member 201 includes the oxide film layers 213a and 213b mainly composed of a Cr ₂ O ₃ film formed on the surface of the metal base material 212, and is formed in the oxidation. The glass layer 11 composed of the V-based low-melting glass containing no Pb on the surface of the film layer 213a allows the metal substrate 212 to be sufficiently bonded to the electronic component housing member 30 (see FIG. 4). Further, since the hermetic sealing cover member 201 is provided with the metal base material 212 containing the 42Ni-6Cr-Fe alloy, the thickness t1 of the hermetic sealing cover member 201 can be made smaller than when the ceramic material is used for the base material. . Further, by including the 42Ni-6Cr-Fe alloy in the metal base material 212, the oxide film layers 213a and 213b composed of the Cr ₂ O ₃ film can be easily formed on the surface of the metal base material 212.

In the second embodiment, the metal base material 212 is configured such that the first layer 212a is disposed on the Z2 side of the first layer 212a and the second layer 212b is disposed on the second layer 212b. The third layer 212c on the Z2 side is formed by joining three layers of cladding materials, and the first layer 212a and the third layer 212c are made of 42Ni-6Cr-Fe alloy, and the second layer 212b is made of 42Ni. Since the Fe base alloy is composed of only one layer as compared with the metal base material 212, the thermal expansion coefficient α2 of the metal base material 212 can be easily adjusted by joining different metal materials having different thermal expansion coefficients to each other. . Further, since the first layer 212a and the third layer 212c composed of 42Ni-6Cr-Fe alloy can be disposed on both surfaces of the hermetic sealing cover member 201, the surface of the metal substrate 212 can be applied to both surfaces (the first layer). The oxide film layers 213a and 213b composed of a Cr ₂ O ₃ film are formed on the surface on the Z1 side of 212a and the surface on the Z2 side of the third layer 212c, respectively. Thereby, unlike the case where the oxide film layer is formed on only one of the surfaces of the both surfaces of the metal substrate 212, it is possible to prevent the glass layer 11 from being erroneously formed on the surface of the metal substrate 212 on which the oxide film layer is not formed. .

In the second embodiment, the first layer 212a, the second layer 212b, and the third layer 212c of the metal base material 212 are made of a Fe-based alloy containing 42% by mass of Ni. The thermal expansion coefficients of the first layer 212a, the second layer 212b, and the third layer 212c can be reduced. Thereby, the thermal expansion coefficient α2 of the metal base material 212 can be made close to the thermal expansion coefficient α1 of the glass layer 11 composed of the V-based low-melting point glass whose thermal expansion coefficient is generally smaller than that of the metal material. Further, when the first layer 212a and the third layer 212c are made of a general 42Ni-6Cr-Fe alloy, and the second layer 212b is made of a general 42Ni-Fe alloy, Fe can be easily formed. The alloy is formed on the surface of the metal substrate 212 corresponding to the region where the glass layer 11 is formed, and the oxide film layers 213a and 213b composed of the Cr ₂ O ₃ film are formed, and the thermal expansion coefficient α2 of the metal substrate 212 is close to V. The thermal expansion coefficient α1 of the glass layer 11 composed of the low melting point glass.

Further, in the second embodiment, as described above, the thermal expansion coefficient α4 (about 75 × 10 ^-7 / ° C) of the first layer 212a and the third layer 212c is made larger than the thermal expansion coefficient α1 of the glass layer 11 (about 70 ×). 10 ^-7 / ° C), and the thermal expansion coefficient α5 (about 40 × 10 ^-7 / ° C) of the second layer 212b is smaller than the thermal expansion coefficient α1 of the glass layer 11, the thickness t5 and the second layer of the first layer 212a can be adjusted. The thickness t6 of 212b and the thickness t5 of the third layer 212c are such that the thermal expansion coefficient α2 of the entire metal substrate 212 is close to the thermal expansion coefficient α1 of the glass layer 11.

Further, in the second embodiment, as described above, the total thickness (2 × t5) of the first layer 212a and the third layer 212c is approximately 50 of the thickness t1 (= 2 × t5 + t6) of the cover 210. Above %, the thermal expansion coefficient α1 of the glass layer 11 and the thermal expansion coefficient α2 of the metal substrate 212 can surely satisfy the relationship of -15×10 ^-7 ≦α2-α1≦5×10 ^-7 , so that it can be surely suppressed by V It is a crack (crack) occurring in the glass layer 11 composed of low melting point glass. Further, other effects of the second embodiment are the same as those of the first embodiment.

(Example)

Next, the measurement of the thermal expansion coefficient performed in order to confirm the effect of the second embodiment will be described with reference to Figs. 18 to 21 .

(Measurement of thermal expansion coefficient)

The measurement of the thermal expansion coefficient described below is as shown in Fig. 19, and the examples 14 to 18 corresponding to the metal base material 212 of the second embodiment are configured to have a structure composed of 42Ni-6Cr-Fe alloy. One layer 212a, a second layer 212b composed of a 42Ni-Fe alloy, and a three-layer cladding material of a third layer 212c composed of a 42Ni-6Cr-Fe alloy, and the thickness of the first layer 212a and the third layer The total thickness of the 212c (2 × t5 (refer to FIG. 18)) is different from the ratio (thickness ratio) of the thickness t1 of the cover 210.

Specifically, as a fourteenth embodiment, the total thickness (2 × t5) of the first layer 212a and the third layer 212c is 12.5% of the thickness t1 of the lid 210, and the thickness t6 of the second layer 212b (see the figure). 18) Set to 87.5% of the thickness t1 of the cover 210. Further, as Example 15, the total thickness (2 × t5) was set to 25% of the thickness t1, and the thickness t6 was set to 75% of the thickness t1. Further, as Example 16, the total thickness (2 × t5) was set to 50% of the thickness t1, and the thickness t6 was set to 50% of the thickness t1. Further, as Example 17, the total thickness (2 × t5) was set to 67% of the thickness t1, and the thickness t6 was set to 33% of the thickness t1. Further, as Example 18, the total thickness (2 × t5) was set to 75% of the thickness t1, and the thickness t6 was set to 25% of the thickness t1.

Further, as Comparative Example 1 of Examples 14 to 18, a metal substrate composed of a 42Ni-Fe alloy similar to Comparative Example 1 of the first embodiment described above was used. That is, as Comparative Example 1, a metal substrate having a thickness ratio t5 of the 42Ni-6Cr-Fe alloy of 0% was used. Further, as Comparative Example 3, a metal substrate composed of a 42Ni-6Cr-Fe alloy similar to that of the fifth embodiment of the first embodiment was used. That is, as Comparative Example 3, a metal substrate having a thickness ratio t5 of 42Ni-6Cr-Fe alloy of 100% was used. In the same manner as in the first embodiment, V-based low melting point glass was used as Reference Example 1, and Al ₂ O _{3 was} used as Reference Example 2.

Then, the elongation of each of the members of Examples 14 to 18, Comparative Examples 1 and 3, and Reference Examples 1 and 2 was determined to be 30 ° C or higher and 250 in the same manner as in the measurement of the thermal expansion coefficient of the first embodiment. Coefficient of thermal expansion in the temperature range below °C.

As shown in Fig. 20, as an experimental result of the elongation measurement, the elongation (thermal expansion coefficient) can be increased by increasing the thickness ratio of the 42Ni-6Cr-Fe alloy.

Further, in the temperature range up to the glass transition point (285 ° C) of the V-based low melting point glass, the elongation of Example 14 (12.5%) and Example 15 (25%) was smaller than that of the V-based low melting point glass (Reference) The elongation of Example 1). On the other hand, the elongations of Examples 16 to 18 and Comparative Example 3 (50% to 100%) approximate the values of the elongation of the V-based low melting point glass (Reference Example 1).

Further, as shown in FIG. 19 and FIG. 21, it was found that the coefficient of thermal expansion is in a temperature range of 30 ° C or more and 250 ° C or less, and the thermal expansion coefficient α 2 of Example 14 (12.5%) is 45 × 10 ^-7 / ° C. Compared with the V-based low melting point glass (Reference Example 1), the thermal expansion coefficient α1 (72 × 10 ^-7 / ° C) is only 27 × 10 ^-7 / ° C. Further, the thermal expansion coefficient α2 of Example 15 (25%) was 51 × 10 ^-7 / ° C, which was small compared with the thermal expansion coefficient α1 (72 × 10 ^-7 / ° C) of the V-based low melting point glass (Reference Example 1). 21 × 10 ^-7 / ° C. That is, when the metal substrate of Example 14 (12.5%) and Example 15 (25%) is bonded to the V-based low-melting point glass at a sealing temperature (about 370 ° C or more and about 400 ° C or less), Since the difference in thermal expansion coefficient (α2-α1) is large (-27(21)×10 ^-7 /°C), it is considered that the glass layer composed of V-based low-melting glass is prone to cracking (cracking) during cooling. .

On the other hand, in the temperature range of 30 ° C or more and 250 ° C or less, the thermal expansion coefficients α 2 of Examples 16 to 18 and Comparative Example 3 (50% to 100%) were 58 × 10 ^-7 /° C. or more and 74 × 10 Below ^-7 / °C, it is found that the thermal expansion coefficient α1 (72 × 10 ^-7 / ° C) of the low-melting glass with V system (Reference Example 1) satisfies -14 × 10 ^-7 ≦ α2-α1 ≦ 2 × 10 ^-7 Relationship. In other words, when the metal substrate of Examples 16 to 18 and the V-based low-melting glass are joined at a sealing temperature, since there is no difference in thermal expansion coefficient, it is considered that the glass can be suppressed from being cooled by the V-based low melting point glass. The glass layer formed is broken. As a result, it is considered to be suitable as a metal base material by setting the ratio of the thickness of the 42Ni-6Cr-Fe alloy to 50% or more of the metal base material (cover).

In addition, the embodiments and examples of the present disclosure are to be considered as illustrative and not restrictive. The scope of the present invention is defined by the scope of the claims and the scope of the claims.

For example, in the first embodiment, the metal base material 12 is an example of a 42Ni-(2-6)Cr-Fe alloy, and in the second embodiment, the metal base material 212 is represented by An example of a first layer 212a composed of a 42Ni-6Cr-Fe alloy, a second layer 212b composed of a 42Ni-Fe alloy, and a cladding material joined by a third layer 212c composed of a 42Ni-6Cr-Fe alloy. However, the invention is not limited thereto. In the present invention, the metal material constituting the metal substrate does not need to contain Ni, and may contain Cr.

In addition, in the first and second embodiments, the oxide film layers 13 (213a and 213b) mainly composed of a Cr ₂ O ₃ film are formed in addition to the portion where the glass layer 11 is disposed, but the present invention is It is not limited to this. In the present invention, the oxide film layer may be formed only in the portion where the glass layer is disposed.

In the second embodiment, the metal base material 212 is an example in which three layers of cladding materials are joined by joining the first layer 212a, the second layer 212b, and the third layer 212c. However, the present invention is not limited thereto. herein. For example, it may be configured such that a first layer made of a 42Ni-6Cr-Fe alloy and a second layer of a 42Ni-Fe alloy are joined to each other. Further, it may be configured by a cladding material in which four or more layers are joined.

In the second embodiment, the first layer 212a and the third layer 212c are examples of a 42Ni-6Cr-Fe alloy having the same composition. However, the present invention is not limited thereto. In the present invention, the composition of the first layer 212a and the composition of the third layer 212c may be different. In this case, the Cr content of the first layer 212a disposed on the side of the glass layer 11 is preferably about 3% by mass or more.

Further, in the first and second embodiments, the glass layer 11 is composed of a V-based low melting point glass containing V ₂ O ₅ -P ₂ O ₅ -TeO-Fe ₂ O ₃ and containing no Pb. For example, the invention is not limited thereto. In the present invention, the glass layer may be a Pb-free glass material other than the V-based low melting point glass. At this time, by using a glass material which is melted under a temperature of about 400 ° C or lower, the influence of heat at the time of sealing on the crystal oscillator can be reduced.

In the first and second embodiments, the crystal oscillator 20 is housed in the electronic component storage case 100. However, the present invention is not limited thereto. For example, a SAW filter (surface acoustic wave filter) may be housed in the electronic component storage case.

1. . . Sealing material for hermetic sealing

2. . . Vacuum furnace

10. . . cover

10a. . . Above

11. . . Glass layer

12. . . Metal substrate

13. . . Oxide film layer

20. . . Crystal oscillator

30. . . Electronic component storage member

31. . . bottom

32. . . framework

32a. . . Above

33. . . Concave

40. . . Bump

100. . . Electronic component storage box

110. . . cover

111, 111a, 111b, 111c. . . Glass layer

112‧‧‧Metal substrate

113‧‧‧Oxidized film

114, 114a, 114b, 114c‧‧‧ paste

201‧‧‧ Sealing material for hermetic sealing

210‧‧‧ Cover

212‧‧‧Metal substrate

212a‧‧‧1st floor

212b‧‧‧2nd floor

212c‧‧‧3rd floor

213a, 213b‧‧‧ oxide film

Thickness of t1, t2, t3, t4, t5, t6‧‧

T4a, t4b, t4c‧‧‧ thickness

L1, L2, L3, L4‧‧‧ length

W, W1, W2, W3‧‧‧ width

W1a, W2a, W3a‧‧‧ width

Fig. 1 is a perspective view showing a configuration of a lid member for hermetic sealing according to a first embodiment of the present invention.

Figure 2 is a cross-sectional view taken along line 300-300 of Figure 1.

3 is a perspective view showing a configuration of an electronic component housing case according to the first embodiment of the present invention.

Figure 4 is a cross-sectional view taken along line 400-400 of Figure 3.

Fig. 5 is a cross-sectional view showing a manufacturing process of the lid member for hermetic sealing according to the first embodiment of the present invention.

Fig. 6 is a cross-sectional view showing a manufacturing process of the electronic component housing case according to the first embodiment of the present invention.

Fig. 7 is a table showing experimental results of measurement of thermal expansion coefficient performed in order to confirm the effects of the first embodiment of the present invention.

Fig. 8 is a graph showing experimental results of measurement of thermal expansion coefficient performed in order to confirm the effects of the first embodiment of the present invention.

Fig. 9 is a graph showing experimental results of measurement of thermal expansion coefficient performed in order to confirm the effects of the first embodiment of the present invention.

Fig. 10 is a table showing the results of experiments for measuring the thickness of the oxide film layer in order to confirm the effects of the first embodiment of the present invention.

Fig. 11 is a table showing the results of experiments for measuring the thickness of the oxide film layer in order to confirm the effects of the first embodiment of the present invention.

Fig. 12 is a cross-sectional view showing an experimental method for measuring the wettability performed in order to confirm the effects of the first embodiment of the present invention.

Fig. 13 is a cross-sectional view showing an experimental method for measuring the wettability performed in order to confirm the effects of the first embodiment of the present invention.

Fig. 14 is a graph showing experimental results of wettability measurement performed in order to confirm the effects of the first embodiment of the present invention.

Fig. 15 is a graph showing experimental results of wettability measurement performed in order to confirm the effects of the first embodiment of the present invention.

Fig. 16 is a graph showing experimental results of wettability measurement performed in order to confirm the effects of the first embodiment of the present invention.

Fig. 17 is a graph showing experimental results of wettability measurement performed in order to confirm the effects of the first embodiment of the present invention.

Fig. 18 is a cross-sectional view showing the configuration of a lid member for hermetic sealing according to a second embodiment of the present invention.

Fig. 19 is a table showing experimental results of measurement of thermal expansion coefficient performed in order to confirm the effects of the second embodiment of the present invention.

Fig. 20 is a graph showing experimental results of measurement of thermal expansion coefficient performed in order to confirm the effects of the second embodiment of the present invention.

Fig. 21 is a graph showing experimental results of measurement of thermal expansion coefficient performed in order to confirm the effects of the second embodiment of the present invention.

10. . . cover

10a. . . Above

11. . . Glass layer

12. . . Metal substrate

13. . . Oxide film layer

T1, t2, t3. . . thickness

W. . . width

Claims (18)

A cover material for hermetic sealing, which is composed of a ceramic material and used for an electronic component storage case containing an electronic component storage member for accommodating electronic components, and a metal base material provided by a cladding material The cladding material includes at least a first layer and a second layer, the first layer contains a metal material containing at least Cr, the second layer contains a metal material different from the first layer, and the coating layer is formed on the first layer The surface of the first layer is made of an oxide film of Cr; and the bonding layer is formed on the surface of the coating layer, and is made of a glass material containing no Pb, and is used for forming the above-mentioned coating layer. The metal substrate is joined to the electronic component housing member; the first layer has a thermal expansion coefficient greater than a thermal expansion coefficient of the bonding layer, and the second layer has a thermal expansion coefficient smaller than a thermal expansion coefficient of the bonding layer. The cover sheet for hermetic sealing according to the first aspect of the invention, wherein the thermal expansion coefficient α1 (/° C.) of the bonding layer and the thermal expansion coefficient of the metal substrate are in a temperature range of 30° C. or more and 250° C. or less. Α2 (/ ° C) satisfies the relationship of -15 × 10 ^-7 ≦ α 2 - α 1 ≦ 5 × 10 ^-7 . The cover sheet for hermetic sealing according to the first aspect of the invention, wherein the coating layer has a thickness of 0.3 μm or more. The cover material for a hermetic seal according to the first aspect of the invention, wherein the metal base material contains Ni, 3% by mass or more and 6% by mass or less of Cr, and Fe-based alloy with Fe. The cover sheet for hermetic sealing according to the fourth aspect of the invention, wherein the metal base material is composed of 42% by mass of Ni, 3% by mass or more and 6% by mass or less of Cr, and a Fe-based alloy of Fe. The cover sheet for hermetic sealing according to the first aspect of the invention, wherein the coating layer is formed on a surface of the metal substrate on which the bonding layer is disposed and on a side opposite to a side on which the bonding layer is disposed On the surface of a metal substrate. The above-mentioned first layer of the metal base material is a Fe-based alloy containing Ni, 3% by mass or more and 6% by mass or less of Cr, and Fe, as disclosed in the first aspect of the invention. Composition. The cover sheet for hermetic sealing according to the first aspect of the invention, wherein the metal substrate is composed of a clad material comprising a layer of the first layer disposed on the side of the bonding layer and containing at least Cr; The second layer disposed on the opposite side of the bonding layer on the side opposite to the bonding layer, and having a metal material different from the first layer; and the second layer disposed on the opposite side of the first layer opposite to the first layer The third layer of Cr. The cover sheet for hermetic sealing according to the eighth aspect of the invention, wherein the first layer and the third layer are each containing Ni, 3% by mass or more and 6 masses. It is composed of Cr or less and Fe-based alloy of Fe. The lid member for hermetic sealing according to claim 9, wherein the first layer and the third layer are each composed of a Fe alloy containing 42% by mass of Ni, 6% by mass of Cr, and Fe. The second layer is made of a Fe-based alloy containing 42% by mass of Ni and Fe. The cover sheet for hermetic sealing according to claim 9, wherein the total thickness of the first layer and the third layer is 50% or more of the entire thickness of the metal substrate. An electronic component storage case comprising: a cover material for hermetic sealing, comprising: a metal base material comprising a clad material, the clad material comprising at least a first layer and a second layer, the first layer a metal material containing at least Cr, the second layer containing a metal material different from the first layer; a coating layer formed on the surface of the first layer and composed of an oxide film of Cr; and a bonding layer Forming on the surface of the coating layer, comprising a glass material not containing Pb; the thermal expansion coefficient of the first layer is greater than a thermal expansion coefficient of the bonding layer, and the thermal expansion coefficient of the second layer is smaller than a thermal expansion coefficient of the bonding layer; The electronic component storage member is joined to the metal substrate on which the coating layer is formed via the bonding layer, and is made of a ceramic material for accommodating the electronic component. The electronic component storage case according to claim 12, wherein the thermal expansion coefficient α1 (/° C.) of the bonding layer and the electronic component storage member are in a temperature range of 30° C. or higher and 250° C. or lower. The coefficient of thermal expansion α3 (/°C) satisfies the relationship of 0≦α1−α3≦10×10 ^-7 . The electronic component storage case according to claim 13, wherein the thermal expansion coefficient α1 (/° C.) of the bonding layer and the electronic component storage member are in a temperature range of 30° C. or higher and 250° C. or lower. The coefficient of thermal expansion α3 (/°C) satisfies the relationship of 0≦α1−α3≦10×10 ^-7 , and the thermal expansion coefficient α1 (/° C.) of the above bonding layer and the thermal expansion coefficient α2 (/° C.) of the above metal substrate satisfy -15. ×10 ^-7 ≦α2-α1≦5×10 ^-7 relationship. A method for producing a lid member for a hermetic seal is a method for producing a lid member for hermetic sealing which is composed of a ceramic material and includes an electronic component storage case for housing an electronic component storage member for an electronic component. The surface of the first layer of the metal substrate comprising a first layer of a metal material containing at least Cr and a second layer of a metal material different from the first layer a step of oxidizing Cr of the first layer to form a coating layer composed of an oxide film of Cr, and forming a glass material containing no Pb on the surface of the coating layer, and used for forming a step of bonding the metal substrate of the coating layer to the electronic component housing member; wherein the first layer has a thermal expansion coefficient greater than a thermal expansion coefficient of the bonding layer, and the second layer has a thermal expansion coefficient smaller than the bonding layer Thermal expansion coefficient. The method for producing a cover material for a hermetic seal according to the fifteenth aspect of the invention, wherein the step of forming the coating layer includes: containing Cr, containing Fe, containing 3% by mass or more and 6% by mass or less, and Fe A step of forming the coating layer composed of an oxide film of Cr on the surface of the metal substrate of the Fe-based alloy metal material. The method for producing a cover sheet for hermetic sealing according to claim 16, wherein the step of forming the coating layer composed of a Cr oxide film has a temperature of 1000 ° C or more and 1150 ° C in a humid hydrogen atmosphere. Under the following temperature conditions, the Cr of the metal substrate is preferentially oxidized, whereby the coating layer composed of the oxide film of Cr is preferentially formed on the surface of the metal substrate. The method for producing a cover sheet for hermetic sealing according to claim 17, wherein the step of forming the coating layer composed of an oxide film of Cr is preferably performed by setting the partial pressure of oxygen to be smaller than Fe And the step of forming the coating layer composed of the oxide film of Cr preferentially under the above-described wet hydrogen atmosphere in which the partial pressure of Ni oxidation is larger than the partial pressure of Cr oxidation.