Clad plate, lid member for hermetic sealing, and small-sized component accommodation package

Abstract

The present invention relates to a clad plate (1) comprising: a first metal layer (11) composed of an Fe alloy containing Ni and Cr, the first metal layer (11) having a thermal expansion coefficient of 5.0-15.0 × 10 −6 / K and a thickness of TB; a second metal layer (12) composed of Cu or a Cu alloy, the second metal layer (12) having a thermal expansion coefficient of 16.0-21.0 × 10−6 / K, a thermal conductivity of 100-400 W / (m·K), and a thickness of TC; and a third metal layer (13) composed of an AG alloy containing Ag and Cu, the clad plate (1) having a diffusion layer both between the first and second metal layers and between the second and third metal layers, and being such that TB is 0.015-0.80 mm, TC is 0.005-0.020 mm, and TB / TC is 2.0-12.0. The present invention also relates to a lid member for hermetic sealing in which the clad plate is used.

Description

Clad plates, hermetic sealing lid materials, and small component housing packages

[0001] The present invention relates to a clad plate, a hermetically sealing lid material, and a small component housing package.

[0002] BACKGROUND ART Airtight sealing lids (hereinafter referred to as "lids") and small component storage packages (hereinafter referred to as "packages") have been known in the past.

[0003] Conventionally, a lid has been known in which a Ni-based metal layer (fourth metal layer) made of Ni or a Ni alloy, a base layer (first metal layer) made of a low-thermal expansion metal, an intermediate metal layer (second metal layer) made of oxygen-free copper, and a brazing material layer (third metal layer) made of a silver brazing alloy are laminated in this order in the thickness direction and diffusion-bonded, and a package using the lid has also been known. Such a package is disclosed, for example, in Japanese Patent No. 3850787. Japanese Patent No. 3850787 discloses that the low-thermal expansion metal constituting the first metal layer has a thermal expansion coefficient of 4.0 to 5.5 × 10 at 30 to 300°C. －６ / K, and exemplified are a 29Ni-17Co-Fe alloy (values ​​are in mass %, the same applies below) and a 42Ni-Fe alloy. Furthermore, Japanese Patent No. 3850787 describes that the thickness of the second metal layer is preferably 10 to 200 μm, and that since it deforms following the deformation of the first metal layer, it has the effect of alleviating thermal stress generated in a ceramic case (hereinafter referred to as "case") made of alumina, aluminum nitride, or the like that constitutes the package.

[0004] The lid is one of the components responsible for hermetically sealing the package and is joined to the case by means such as resistance welding (e.g., seam welding) or electron beam welding. During this process, the lid is heated to melt the third metal layer, and the molten metal solidifies, bonding the lid to the case. Heating the lid causes the first and second metal layers constituting the lid to expand and contract thermally. This thermal contraction, in particular, exerts relatively large thermal stress on the joint surface with the case and the case body. The large thermal stress can cause separation of the joint surface with the case and cracks in the case body, resulting in poor hermeticity (reduced airtightness) of the package. To address this issue, a lid may be used that includes a first metal layer made of a low-thermal expansion metal such as 29Ni-17Co-Fe alloy (hereinafter referred to as "KV") and a second metal layer made of oxygen-free copper with a thickness of 10 to 200 μm, which exhibits thermal stress relaxation effects.

[0005] Also, a lid and a package using the lid have been known, which are formed by stacking and diffusion-bonding a second surface layer (fourth metal layer) made of Ni or a Ni alloy, a base layer (first metal layer) made of a Ni—Cr—Fe alloy, a first surface layer (second metal layer) made of Ni or a Ni alloy, and a silver solder layer (third metal layer) in this order in the thickness direction. Such a package is disclosed, for example, in Japanese Patent No. 5632563. Japanese Patent No. 5632563 discloses that the Ni—Cr—Fe alloy constituting the first metal layer contains 1 to 10 mass % of Cr (preferably 6 to 10 mass %). Patent Document 2 also discloses that a first metal layer containing Cr forms a passivation film made of Cr oxide on its surface, exhibiting corrosion resistance not obtainable with a first metal layer made of, for example, KV that does not contain Cr. Therefore, when the edge of the lid is exposed by press processing or the like, it is possible to use a lid including a first metal layer made of, for example, a 42Ni-6Cr-Fe alloy containing Cr (hereinafter referred to as "NRS") in order to suppress corrosion of the edge of the first metal layer.

[0006] Patent No. 3850787 Patent No. 5632563

[0007] Conventionally, in applications where the end faces are exposed by press working or the like, corrosion from the end faces can be a problem when the base material (first metal layer) is made of the above-mentioned KV, which does not contain Cr. On the other hand, when the base material (first metal layer) is made of the above-mentioned NRS, which has good corrosion resistance due to the inclusion of Cr, corrosion from the end faces does not occur. However, NRS has a larger thermal expansion coefficient than KV. For example, when comparing the thermal expansion coefficients at 500°C, KV is approximately 5.0 x 10 －６ / K, whereas NRS is about twice as high, at about 10.0 × 10 －６ / K. Therefore, in the case of a base material (first metal layer) made of NRS, some ingenuity is required to obtain a sufficient thermal stress relaxation effect. For example, a possible configuration is to combine a base material (first metal layer) made of NRS with a copper layer (second metal layer) made of oxygen-free copper with a thickness of 10 to 200 μm, which has a thermal stress relaxation effect.

[0008] However, the copper layer (second metal layer) made of oxygen-free copper has a significantly higher thermal expansion coefficient and thermal conductivity than the base material (first metal layer) made of NRS. For example, oxygen-free copper (such as C1020 of the JIS standard) has a thermal expansion coefficient of approximately 17.7 × 10 between 20 and 300°C. －６ / K and the thermal conductivity at 20°C is about 390 W / (m K), whereas the thermal expansion coefficient of NRS at 500°C is about 5.0 × 10 －６ / K, and its thermal conductivity at 20°C is approximately 15 W / (m·K). Therefore, the difference between oxygen-free copper and NRS is quite large. As a result, there is a risk that the thermal stress relaxation effect of the copper layer (second metal layer) will be impaired due to the particularly high thermal expansion coefficient of oxygen-free copper. In particular, when the thermal stress (equivalent stress) acting on the case due to thermal stress exceeds 2.0 GPa, the probability of peeling of the bonding surface and cracking of the case body increases. Therefore, it is necessary to devise a way to prevent peeling of the bonding surface between the lid and the case and cracking of the case body due to large thermal stress.

[0009] The object of the present invention is to provide a clad plate that has good corrosion resistance of the base material (first metal layer) even in applications where the end surface is exposed by press processing or the like, and that provides a thermal stress relief effect when heated for seam welding or the like, a hermetic sealing lid material using the clad plate, and a small component storage package using the hermetic sealing lid material.

[0010] The clad plate according to the present invention is made of an Fe alloy containing Ni and Cr, and has a thermal expansion coefficient of 5.0×10 －６ / K or more 15.0×10 －６ / K or less and having a thickness of TB; and a first metal layer made of Cu or a Cu alloy and having a thermal expansion coefficient of 16.0×10 －６ / K or more 21.0×10 －６ / K or less, and has a thermal conductivity of 100 W / (m·K) or more and 400 W / (m·K) or less, and includes a second metal layer having a thickness of TC, and a third metal layer made of an Ag alloy containing Ag and Cu, and has diffusion layers between the first metal layer and the second metal layer and between the second metal layer and the third metal layer, wherein TB is 0.015 mm or more and 0.080 mm or less, TC is 0.005 mm or more and 0.020 mm or less, and TB / TC is 2.0 or more and 12.0 or less.

[0011] In the clad plate of the present invention, the clad plate may further include a fourth metal layer made of Ni or a Ni alloy, and may have diffusion layers between the fourth metal layer and the first metal layer, between the first metal layer and the second metal layer, and between the second metal layer and the third metal layer.

[0012] The clad plate according to the present invention can be used to form a hermetic sealing lid. That is, the hermetic sealing lid according to the present invention is a hermetic sealing lid made of a clad plate, which seals a small component incorporating an electronic circuit in a package housing space by brazing to a ceramic case that defines the housing space, and the clad plate is made of an Fe alloy containing Ni and Cr and has a thermal expansion coefficient of 5.0×10 －６ / K or more 15.0×10 －６ / K or less and having a thickness of TB; and a first metal layer made of Cu or a Cu alloy and having a thermal expansion coefficient of 16.0×10－６ / K or more 21.0×10 －６ / K or less, and has a thermal conductivity of 100 W / (m·K) or more and 400 W / (m·K) or less, and includes a second metal layer having a thickness of TC, and a third metal layer made of an Ag alloy containing Ag and Cu, and has diffusion layers between the first metal layer and the second metal layer and between the second metal layer and the third metal layer, wherein TB is 0.015 mm or more and 0.080 mm or less, TC is 0.005 mm or more and 0.020 mm or less, and TB / TC is 2.0 or more and 12.0 or less.

[0013] In the hermetic sealing lid material of this invention, the clad plate may further include a fourth metal layer made of Ni or a Ni alloy, and may have diffusion layers between the fourth metal layer and the first metal layer, between the first metal layer and the second metal layer, and between the second metal layer and the third metal layer.

[0014] The hermetically sealing lid according to the present invention can be used to form a small component storage package. That is, the small component storage package according to the present invention is a package including a small component incorporating an electronic circuit, a storage space for the small component, a ceramic case defining the storage space, and a hermetically sealing lid made of a clad plate that seals the small component in the storage space by brazing to the ceramic case, wherein the clad plate is made of an Fe alloy containing Ni and Cr and has a thermal expansion coefficient of 5.0×10 －６ / K or more 15.0×10 －６ / K or less and having a thickness of TB; and a first metal layer made of Cu or a Cu alloy and having a thermal expansion coefficient of 16.0×10 －６ / K or more 21.0×10 －６ / K or less, and has a thermal conductivity of 100 W / (m·K) or more and 400 W / (m·K) or less, and includes a second metal layer having a thickness of TC, and a third metal layer made of an Ag alloy containing Ag and Cu, and has diffusion layers between the first metal layer and the second metal layer and between the second metal layer and the third metal layer, wherein TB is 0.015 mm or more and 0.080 mm or less, TC is 0.005 mm or more and 0.020 mm or less, and TB / TC is 2.0 or more and 12.0 or less.

[0015] In the small component housing package of the present invention, the clad plate may further include a fourth metal layer made of Ni or a Ni alloy, and may have diffusion layers between the fourth metal layer and the first metal layer, between the first metal layer and the second metal layer, and between the second metal layer and the third metal layer.

[0016] According to this invention, it is possible to obtain a clad plate that has good corrosion resistance of the base material (first metal layer) even in applications where the end surface is exposed by press processing, etc., and that provides a thermal stress relief effect when heated, such as during seam welding, a lid using this clad plate, and a small component housing package using this lid.

[0017] 1 is a diagram showing an example (configuration example) of an embodiment of a small component housing package according to the present invention from above (Z1 side); FIG. 2 is a diagram showing a cross section taken along line P-P shown in FIG. 1 from the side (Y2 side); FIG. 3 is a diagram showing an example (configuration example A) of an embodiment of a clad plate (hermetically sealing lid material) according to the present invention; FIG. 4 is a diagram showing an example (configuration example B) of an embodiment of a clad plate (hermetically sealing lid material) according to the present invention; FIG. 5 is a diagram (graph) created using the thickness TC of the second metal layer and the equivalent stress σ of the case side shown in Table 2; and FIG. 6 is a diagram (graph) created using the results of analyses 6 to 9 and 11 to 12 shown in Table 2 and analyses 13 to 16 shown in Table 3.

[0018] The clad plate of this invention, the hermetic sealing lid material (hereinafter referred to as "lid") using the clad plate, and the small component housing package (hereinafter referred to as "package") using the lid will be described below with reference to the drawings as appropriate, using examples of configurations that are considered to be preferred embodiments.

[0019] 1 and 2 show an example of the configuration of a package 100. The package 100 is an example of an embodiment of a small component housing package according to the present invention.

[0020] As shown in Figures 1 and 2, package 100 comprises a small component 2 incorporating an electronic circuit, an accommodation space 3 for small component 2, a ceramic case 4 (hereinafter referred to as "case 4") that defines accommodation space 3, and a lid 1. In package 100, small component 2 is electrically connected to printed wiring (not shown) on the surface of case 4 by wire bonding 5. Small component 2 is sealed in accommodation space 3 by brazing lid 1 to case 4. Brazing lid 1 to case 4 can be performed by resistance welding (such as seam welding) or electron beam welding, using a third metal layer (see Figures 3 to 5) of lid 1, which will be described later.

[0021] The package 100 is, for example, a surface-mounted device package (SMD package). The small component 2 is, for example, a surface acoustic wave filter (SAW filter), a quartz resonator, or an oscillator. The case 4 is, for example, composed of a case 4a, a case 4b, and a case 4c, as shown in FIG. 2 . The case 4 is not limited to a configuration in which the case 4a, the case 4b, and the case 4c are formed separately and then combined. The case 4 may also be a configuration in which the case 4a, the case 4b, and the case 4c are integrally formed.

[0022] The size of the package 100 suitable for using the lid 1 made of the clad plate according to the present invention is, for example, a long side (X direction) of approximately 1 mm to 5 mm and a short side (Y direction) of approximately 0.5 mm to 3.0 mm. Furthermore, the thickness (Z direction) of the package 100 is preferably approximately 0.50 mm to 1.00 mm from the viewpoint of miniaturization (low profile) of the package 100. With respect to the above size of the package 100, the preferred thickness (Z direction) of the lid 1 is approximately 0.05 mm to 0.10 mm. Note that the longer the lengths of the long and short sides of the lid 1 made of the clad plate, the greater the amount of warpage. Furthermore, for the lid 1 bonded to the case 4 using the third metal layer 13, the longer the lengths of the long and short sides, the greater the overall area and volume of the third metal layer 13, while the area and volume of the portion of the third metal layer 13 that does not contribute to bonding to the case 4 also increase. A lid having a thickness of 0.05 mm or more can prevent the third metal layer 13 from excessively melting when joined to the case 4. A lid having a thickness of 0.10 mm or less can reduce the height (X direction) of the package 100, contributing to a smaller package size (low profile). From the above perspective, it is preferable to select the size of the package 100 using the lid 1 in consideration of the suitability of the mechanical properties of the lid 1, the utilization efficiency of the third metal layer 13, etc.

[0023] The lid 1 used in the package 100 may be formed, for example, using any one of the clad plates 1A, 1B, and 1C shown as configuration examples A to C in Figures 3 to 5. Each of the clad plates 1A, 1B, and 1C is particularly suitable as a lid 1 used to manufacture a package 100 by sealing a small component 2 incorporating an electronic circuit in a case 4. Note that each of the clad plates 1A, 1B, and 1C is an example of an embodiment of the clad plate according to the present invention. Furthermore, the lid 1 formed using any of the clad plates 1A, 1B, and 1C is an example of an embodiment of the hermetic sealing lid material according to the present invention.

[0024] 3 as Configuration Example A includes a first metal layer 11, a second metal layer 12, and a third metal layer 13. The first metal layer 11, the second metal layer 12, and the third metal layer 13 are stacked in this order in the thickness direction (Z direction) and diffusion bonded. In detail, a first metal plate for forming the first metal layer 11, a second metal plate for forming the second metal layer 12, and a third metal plate for forming the third metal layer 13 are stacked in this order in the thickness direction (Z direction) and pressure-bonded (clad rolling) at an appropriate rolling reduction to obtain a rolled material, and the rolled material is then subjected to diffusion annealing under appropriate conditions. This results in a clad plate 1A being obtained in which a first metal layer 11 having a thickness of TB, a second metal layer 12 having a thickness of TC, and a third metal layer 13 having a thickness of TA are stacked in this order in the thickness direction (Z direction) and diffusion bonded, with diffusion layers between the first metal layer 11 and the second metal layer 12 and between the second metal layer 12 and the third metal layer 13.

[0025] In the clad plate 1A, the first metal layer 11 is made of an Fe alloy containing Ni and Cr, and has a thermal expansion coefficient of 5.0×10 －６ / K or more 15.0×10 －６ / K or less. In the clad plate 1A, the first metal layer 11 is made of an Fe alloy containing Ni and an appropriate amount of Cr, so that a passivation film made of Cr oxide is formed on the surface of the first metal layer 11. This improves the corrosion resistance of the first metal layer 11 itself, and even if the end surface is exposed by press working or the like, the corrosion resistance of the first metal layer 11 constituting the clad plate 1A can be maintained at a good level. As a result, even if the clad plate 1A is used, for example, in the lid 1, the rust prevention performance of the lid 1 can be maintained.

[0026] The first metal layer 11 that predominantly constitutes the clad plate 1A is 5.0×10 －６ / K or more 15.0×10 －６By having a thermal expansion coefficient of 1 / K or less, thermal deformation of the first metal layer 11 in the clad plate 1A due to heating and cooling is suppressed. Therefore, the thermal stress relaxation effect of the first metal layer 11 can suppress excessive thermal deformation of the clad plate 1A, even in applications requiring heating, such as seam welding. This allows the clad plate 1A, for example, to maintain the thermal stress relaxation performance of the lid 1, even when used as the lid 1 described above. As a result, thermal stress generated between the lid 1 and the case 4 is reduced, preventing peeling between the lid and case bonding surfaces and damage to the package 100 due to thermal stress. The thermal expansion coefficient of the first metal layer 11 may be measured based on the thermal expansion coefficient at 30 to 300°C, making it possible to predict the amount of thermal deformation even in applications involving exposure to a relatively high-temperature heating atmosphere, such as seam welding. The thermal expansion coefficient can be measured using a test piece with a diameter of 3.5 mm and a length of 50 mm, using a horizontal thermal expansion measuring device with a total expansion type elongation detection rod.

[0027] The Fe alloy containing Ni and Cr that constitutes the first metal layer 11 has a 5.0×10 －６ / K or more 15.0×10 －６ This allows for the easy formation of a first metal layer 11 having a thermal expansion coefficient of 0.1 / K or less. The Fe alloy containing Ni and Cr that constitutes the first metal layer 11 can be an Fe alloy consisting of 36% by mass to 48% by mass of Ni, 1% by mass to 10% by mass of Cr, and the remainder being Fe and unavoidable impurities. In this case, the Cr content is preferably 4% by mass to 10% by mass, and more preferably 6% by mass to 10% by mass. The Ni content is preferably 40% by mass to 44% by mass. Specifically, for example, a 42Ni-4Cr-Fe alloy, a 42Ni-6Cr-Fe alloy, or a 29Ni-17Co-4Cr-Fe alloy can be used, in terms of mass percent.

[0028] In the clad plate 1A, the second metal layer 12 is made of Cu or a Cu alloy and has a thermal expansion coefficient of 16.0×10 －６ / K or more 21.0×10 －６ / K or less, and a thermal conductivity of 100 W / (m·K) or more and 400 W / (m·K) or less. As described above, clad plate 1A includes second metal layer 12 between first metal layer 11 and third metal layer 13. Therefore, second metal layer 12 made of Cu or a Cu alloy is located between first metal layer 11, which is harder than second metal layer 12 (for example, hardness of about 150 HV and thickness of 0.015 mm or more and 0.080 mm or less), and third metal layer 13, which is softer than second metal layer 12 (for example, hardness of about 80 HV and thickness of 0.003 mm or more and 0.025 mm or less). The clad plate 1A includes a second metal layer 12 made of Cu or a Cu alloy and having an appropriate hardness and thickness (e.g., a hardness of approximately 100 HV and a thickness of 0.005 mm to 0.020 mm). This allows the difference in hardness between the first metal layer 11, which is harder than the second metal layer 12, and the third metal layer 13, which is softer than the second metal layer 12, to be reduced. Additionally, Cu or a Cu alloy has a lower 0.2% yield strength and is more susceptible to plastic deformation than Ni or a Ni alloy. Therefore, for example, the inclusion of the second metal layer 12 improves the bondability between the first metal layer 11 and the third metal layer 13 during pressure welding (clad rolling) of the clad plate 1A.

[0029] In the clad plate 1A, the second metal layer 12 has a thermal expansion coefficient of 5.0×10 －６ / K or more 15.0×10 －６ / K or less, and a third metal layer 13 made of an Ag alloy containing Ag and Cu (for example, a thermal expansion coefficient of 14.0×10 －６ / K or more 17.0×10 －６ / K or less). The clad plate 1A has a thermal expansion coefficient of 16.0 × 10 －６ / K or more 21.0×10 －６By providing the second metal layer 12 having a moderate thickness and a thermal expansion coefficient of 1 / K or less, the difference in the thermal expansion coefficient between the first metal layer 11 and the third metal layer 13 can be mitigated in a configuration in which the difference in the thermal expansion coefficient between the first metal layer 11 and the third metal layer 13 is relatively large. As a result, when the clad plate 1A is used in the lid 1 described above, the thermal stress mitigation performance of the lid 1 can be improved compared to a configuration in which the second metal layer 12 having the above configuration is not provided. As a result, the thermal stress generated between the lid 1 and the case 4 is reduced, thereby suppressing damage to the package 100 due to thermal stress. The thermal expansion coefficient of the second metal layer 12 may be set to the same thermal expansion coefficient at 30 to 300°C as that of the first metal layer 11.

[0030] Furthermore, by providing the clad plate 1A with the second metal layer 12 having a thermal conductivity of 100 W / (m K) or more and 400 W / (m K) or less, when heat generation or heating begins on the upper side (Z1 side) of the clad plate 1A by seam welding or the like and the heat is conducted from the first metal layer 11 through the second metal layer 12 to the third metal layer 13, the heat conduction can be made faster and smoother. When the third metal layer 13 melts and liquefies due to heating, Cu, a constituent element of the second metal layer 12, thermally diffuses to the third metal layer 13 by the thermal conduction, lowering the melting point of the liquefied third metal layer 13, thereby reducing the total amount of heat applied to the clad plate 1A. As a result, when the clad plate 1A is used in the lid 1, for example, compared to a configuration that does not include the second metal layer 12 having the above configuration, the thermal stress relaxation performance of the lid 1 is improved and the brazing bondability between the first metal layer 11 of the lid 1 and the case 4 is improved. Note that the thermal conductivity of the second metal layer 12 may be determined based on the thermal conductivity measured by the temperature gradient method employed by Nippon Steel Technology Co., Ltd., etc., and it is possible to predict the amount of heat conduction even in applications where the lid is exposed to a relatively high-temperature heating atmosphere due to heating such as seam welding.

[0031] The Cu or Cu alloy constituting the second metal layer 12 has a concentration of 16.0×10 －６ / K or more 21.0×10 －６The second metal layer 12 can be easily configured to have a thermal expansion coefficient of 17.7×10 / K or less and a thermal conductivity of 100 W / (m·K) or more and 400 W / (m·K) or less. In particular, pure copper (Cu) such as JIS C1020 or C1100 is suitable, and has a thermal conductivity of about 17.7×10 －６ The second metal layer 12 can be easily constructed to have a coefficient of thermal expansion of about 1 / K and a thermal conductivity of about 391 W / (m·K).

[0032] Examples of Cu or Cu alloys suitable for forming the second metal layer 12 include JIS standards C1020 (17.7, 391), C1100 (17.7, 391), C1201 (17.7, 381), C1220 (17.7, 339), C1441 (17.3, 343 to 360), C1510 (17.7, 360), C1921: (17.5, 345 to 364), C1940 (17.6, 284), C2600 (19.9, 121), C2680 (20.3, 117), and C2801 (20.8, 121), as well as C4250 and C7250. The values ​​in parentheses after the alloy number, such as C1020, are representative values, and the former indicates the thermal expansion coefficient (×10 －６ / K), and the latter is the thermal conductivity (W / (m·K)).

[0033] In the clad plate 1A, the third metal layer 13 is made of an Ag alloy containing Ag and Cu. The clad plate 1A has a suitable thickness of the third metal layer 13 made of an Ag alloy containing Ag and Cu, allowing it to be easily bonded to other components via the third metal layer 13, which melts and liquefies when heated by seam welding or the like. For example, when the clad plate 1A is used for the lid 1, the third metal layer 13 functions as a bonding material that melts and liquefies when heated when the lid 1 is bonded to the case 4. This allows the lid 1, which includes the third metal layer 13 functioning as a bonding material, to be easily bonded (brazed) to the case 4 by heating by seam welding or the like.

[0034] Furthermore, for example, when a clad plate is used as a lid, if the clad plate 1A including the third metal layer 13 having the above-described configuration is used, airtight sealing can be easily achieved without using a separate component such as a seal ring including a bonding layer, as in the package 100. As a result, the seal ring can be eliminated when manufacturing a package, as in the package 100, and the package can be made smaller (lower in height) by the amount corresponding to the absence of the seal ring.

[0035] The Ag alloy containing Ag and Cu that constitutes the third metal layer 13 is preferably an Ag alloy primarily composed of Ag and containing 5 to 45% Cu by mass. This Ag alloy is generally classified as a hard solder with a high joining temperature (approximately 700°C to 900°C) and is called a silver solder. The primary component of silver solder is Ag, and binary Ag-Cu and ternary Ag-Cu-Zn silver solders are well-known. Suitable Ag alloys (silver solders) for the third metal layer 13 include, for example, JIS standards BAg-1 to BAg-24, as well as 10Cu-Ag alloy, 15Cu-Ag alloy, and 20Cu-Ag alloy, in terms of mass percent. The melting points of silver solders are, for example, approximately 870°C for 15Cu-Ag alloy and approximately 780°C for 72Ag-Cu alloy. Therefore, for example, if the second metal layer 12 is made of JIS C1020 (melting point of approximately 1085°C) and the third metal layer 13 is made of a 15Cu-Ag alloy (melting point of approximately 870°C), the heating during bonding of the lid 1 and the case 4 may cause the Cu in the second metal layer 12 to diffuse or dissolve into the third metal layer 13, causing the Ag concentration in the third metal layer 13 to shift toward the eutectic point (approximately 780°C), lowering the melting point of the third metal layer 13. In this case, thermal deformation on the lid 1 side during welding is reduced, and the effect of minimizing the difference in thermal deformation occurring between the lid 1 side and the case 4 side is obtained.

[0036] In the clad plate 1A, where TB is the thickness of the first metal layer 11 made of an Fe alloy containing Ni and Cr, and TC is the thickness of the second metal layer 12 made of Cu or a Cu alloy, TB is 0.015 mm or more and 0.080 mm or less, TC is 0.005 mm or more and 0.020 mm or less, and TB / TC is 2.0 or more and 12.0 or less. Furthermore, in the clad plate 1A, where TA is the thickness of the third metal layer 13 made of Ag and an Ag alloy containing Cu, TA is preferably 0.003 μm or more and 0.025 μm or less. Therefore, the total thickness of the clad plate 1A can be calculated by T = TB + TC + TA.

[0037] As described above, in the clad plate 1A, the thickness TB of the first metal layer 11 made of an Fe alloy containing Ni and Cr is 0.015 mm or more and 0.080 mm or less. Having a thickness of 0.015 mm or more and 0.080 mm or less for the first metal layer 11 made of an Fe alloy containing Ni and Cr results in favorable thermal and electrical properties of the first metal layer 11. Therefore, if the size of the opening in the case 4 is appropriate, heat generated by the first metal layer 11 and the resulting melting of the third metal layer 13 (Ag alloy) can proceed smoothly and efficiently when the lid 1 and the case 4 are joined. Furthermore, by making the thickness of the first metal layer 11 0.015 mm or more, the rigidity of the lid 1 can be ensured and excessive thermal deformation during joining with the case 4 can be suppressed, contributing to improved hermetic sealing with the case 4. Furthermore, by making the thickness of the first metal layer 11 0.080 mm or less, it is possible to stabilize the heat generated when joining with the case 4 and the melting of the third metal layer 13 (Ag alloy), which not only improves the airtight sealing with the case 4 but also contributes to making the lid 1 lighter and smaller (lower in height).

[0038] As described above, in the clad plate 1A, the thickness TC of the second metal layer 12 made of Cu or a Cu alloy is 0.005 mm or more and 0.020 mm or less. Having a thickness of 0.005 mm or more and 0.020 mm or less for the second metal layer 12 made of Cu or a Cu alloy results in the second metal layer 12 being relatively more susceptible to thermal deformation than the first metal layer 11 having the above thickness, which is a preferable property. This allows the second metal layer 12 to thermally deform to follow the thermal deformation of the first metal layer 11 when joined to the case 4, thereby reducing thermal stress acting on the joint with the case 4, etc. Furthermore, by setting the thickness TC of the second metal layer 12 to 0.005 mm or more, the second metal layer 12 can thermally deform to follow the thermal deformation of the first metal layer 11 when joined to the case 4, and the fillet shape can be stabilized, contributing to improved hermetic sealing with the case 4. Furthermore, by setting the thickness TC of the second metal layer 12 to 0.020 mm or less, excessive thermal deformation of the second metal layer 12 that exceeds the ability to follow the thermal deformation of the first metal layer 11 when joining to the case 4 can be suppressed, and excessive growth of the fillet can be suppressed, which not only improves the airtight sealing with the case 4 but also contributes to making the lid 1 lighter and smaller (lower in height).

[0039] As described above, in the clad plate 1A, the ratio (layer thickness ratio) of the thickness TB of the first metal layer 11 made of an Fe alloy containing Ni and Cr to the thickness TC of the second metal layer 12 made of Cu or a Cu alloy, TB / TC, is 2.0 or more and 12.0 or less. In the clad plate 1A, TB / TC being 2.0 or more and 12.0 or less, results in a preferable property in which the second metal layer 12 is more susceptible to thermal deformation relative to the deformation of the first metal layer 11. This allows the second metal layer 12 to be thermally deformed to follow the thermal deformation of the first metal layer 11 when joined to the case 4, thereby reducing thermal stress acting on the joint with the case 4, etc. By setting TB / TC to 2.0 or greater, it is possible to ensure the relative thickness TB of the first metal layer 11 relative to the thickness TC of the second metal layer 12, thereby ensuring the rigidity of the lid 1 and suppressing excessive thermal deformation of the second metal layer 12 that exceeds the ability of the first metal layer 11 to follow the thermal deformation, thereby achieving a hermetic seal of the package 100 by bonding the lid 1 to the case 4. For the same reasons as above, TB / TC is preferably set to 2.3 or greater, and more preferably set to 2.5 or greater. By setting TB / TC to 12.0 or less, it is possible to ensure the relative thickness TC of the second metal layer 12 relative to the thickness TB of the first metal layer 11, thereby stabilizing the fillet shape and achieving a hermetic seal of the package 100 by bonding the lid 1 to the case 4. Furthermore, by setting TB / TC to 12.0 or less, the thickness TB of the first metal layer 11 is prevented from becoming excessive, which contributes to reducing the weight and size (profile) of the lid 1. For the same reasons as above, TB / TC is preferably set to 8.0 or less, and more preferably set to 7.0 or less.

[0040] As described above, in the clad plate 1A, the thickness TA of the third metal layer 13 made of an Ag alloy containing Ag and Cu is preferably 0.003 mm or more and 0.025 mm or less. By having the thickness of the third metal layer 13 made of an Ag alloy containing Ag and Cu preferably 0.003 mm or more and 0.025 mm or less, when the third metal layer 13 is used as a joining layer for joining (brazing) the third metal layer 13 to the case 4, the thickness of the third metal layer 13 necessary for brazing can be ensured. This prevents difficulties in hermetically sealing the package 100 by joining the lid 1 and the case 4. Furthermore, setting the thickness TA of the third metal layer 13 to 0.003 mm or more is advantageous for fillet formation by the third metal layer 13, thereby achieving hermetic sealing of the package 100 by joining the lid 1 and the case 4. Furthermore, by setting the thickness TA of the third metal layer 13 to 0.025 mm or less, not only can the third metal layer 13 be saved, but the fillet shape can be stabilized, and the package 100 can be hermetically sealed by joining the lid 1 and the case 4.

[0041] <Configuration Example B> A clad plate 1B shown in Fig. 4 as Configuration Example B includes the first metal layer 11, the second metal layer 12, and the third metal layer 13 similar to those of Configuration Example A above, and further includes a fourth metal layer 14. As shown in Fig. 4, the fourth metal layer 14 is disposed on the opposite side (Z1 side) of the first metal layer 11 from the second metal layer 12 side (Z2 side). The fourth metal layer 14, the first metal layer 11, the second metal layer 12, and the third metal layer 13 are stacked in this order in the thickness direction (Z direction) and diffusion bonded. Specifically, a fourth metal plate for forming the fourth metal layer 14, a first metal plate for forming the first metal layer 11, a second metal plate for forming the second metal layer 12, and a third metal plate for forming the third metal layer 13 are stacked in this order in the thickness direction (Z direction) and pressure-welded (clad rolling) at an appropriate rolling reduction ratio to obtain a rolled material, and the rolled material is then diffusion-annealed under appropriate conditions. This results in a clad plate 1B in which the fourth metal layer 14 having a thickness TN, the first metal layer 11 having a thickness TB, the second metal layer 12 having a thickness TC, and the third metal layer 13 having a thickness TA are stacked in this order in the thickness direction (Z direction) and diffusion-bonded, with diffusion layers between the fourth metal layer 14 and the first metal layer 11, between the first metal layer 11 and the second metal layer 12, and between the second metal layer 12 and the third metal layer 13.

[0042] 4 has substantially the same configuration as the clad plate 1A, except that it has a fourth metal layer 14 and a diffusion layer between the fourth metal layer 14 and the first metal layer 11. Therefore, for the configuration of the clad plate 1B other than the fourth metal layer 14, please refer to the explanation of the above-mentioned configuration example A.

[0043] In the clad plate 1B, the fourth metal layer 14 is made of Ni or a Ni alloy. The fourth metal layer 14 made of Ni or a Ni alloy is generally considered to have better corrosion resistance, particularly better resistance to saltwater, than the first metal layer 11 made of an Fe alloy containing Ni and Cr. Therefore, the clad plate 1B, which includes a fourth metal layer 14 of a moderate thickness T N made of Ni or a Ni alloy, is more advantageous for use in environments such as ports where the atmospheric salt concentration is higher than that of the clad plate 1A. Furthermore, by using a manufacturing method using pressure welding (clad rolling) to form the fourth metal layer 14 using a fourth metal plate as described above, the man-hours (takt time) required to manufacture the clad plate 1B can be expected to be reduced compared to a manufacturing method using nickel plating to form the fourth metal layer 14. The thickness T N of the fourth metal layer 14 is preferably 0.001 mm or more and 0.008 mm or less. By setting the thickness TN of the fourth metal layer 14 to 0.001 mm or more, the saltwater resistance can be improved. On the other hand, by setting the thickness TN of the fourth metal layer 14 to 0.008 mm or less, the weight and size (height) of the lid 1A can be reduced.

[0044] The Ni or Ni alloy constituting the fourth metal layer 14 may be general pure Ni, a Ni alloy containing Ni and Cu, etc. For example, general pure Ni has a thermal expansion coefficient of about 13.0×10 －６ / K, which overlaps with the range of the thermal expansion coefficient of the first metal layer 11 described above, and can suppress the effect of thermal deformation caused by the fourth metal layer 14 on the first metal layer 11. Furthermore, by using pure Ni for the fourth metal layer 14, it is possible to easily distinguish the front and back of the lid (the pure Ni surface or the Ag brazed surface) during packaging, which is preferable due to the difference in the inherent color tone between the pure Ni and the third metal layer 13.

[0045] <Configuration Example C> The clad plate 1C shown in Figure 5 as Configuration Example C includes the first metal layer 11, the second metal layer 12, and the third metal layer 13 similar to those in Configuration Example A, and further includes two fourth metal layers 14 (14a, 14b). As shown in Figure 5, of the two fourth metal layers 14 (14a, 14b), the fourth metal layer 14a is disposed on the opposite side (Z1 side) of the first metal layer 11 from the second metal layer 12 side (Z2 side), similar to Configuration Example B. The other fourth metal layer 14b is disposed on the opposite side (Z2 side) of the first metal layer 11 from the fourth metal layer 14a side (Z1 side), between the first metal layer 11 and the second metal layer 12.

[0046] 5, the fourth metal layer 14a, the first metal layer 11, the fourth metal layer 14b, the second metal layer 12, and the third metal layer 13 are stacked in this order in the thickness direction (Z direction) and diffusion-bonded. As an example, one fourth metal plate for constituting the fourth metal layer 14a, the first metal plate for constituting the first metal layer 11, the other fourth metal plate for constituting the fourth metal layer 14b, the second metal plate for constituting the second metal layer 12, and the third metal plate for constituting the third metal layer 13 are stacked in this order in the thickness direction (Z direction) and pressure-bonded (clad rolling) at an appropriate rolling reduction to obtain a rolled material, and the rolled material is then diffusion-annealed under appropriate conditions. This results in a clad plate 1C being obtained in which a fourth metal layer 14a having a thickness of TNa, a first metal layer 11 having a thickness of TB, a fourth metal layer 14b having a thickness of TNb, a second metal layer 12 having a thickness of TC, and a third metal layer 13 having a thickness of TA are stacked in this order in the thickness direction (Z direction) and diffusion bonded, with diffusion layers between the fourth metal layer 14a and the first metal layer 11, between the first metal layer 11 and the fourth metal layer 14b, between the fourth metal layer 14b and the second metal layer 12, and between the second metal layer 12 and the third metal layer 13.

[0047] 5 shows a clad plate 1C in which a first metal layer 11, a second metal layer 12, and a third metal layer 13, each coated with a plating film, are stacked in this order in the thickness direction (Z direction) and diffusion-bonded. As an example, a plating film made of Ni or a Ni alloy that will form a fourth metal layer is formed on both sides of a first metal plate that will form the first metal layer 11. Then, a first metal plate having plating films that will form the fourth metal layer 14a, the first metal layer 11, and the fourth metal layer 14b, a second metal plate that will form the second metal layer 12, and a third metal plate that will form the third metal layer 13 are stacked in this order in the thickness direction (Z direction) and pressure-bonded (clad rolling) at an appropriate rolling reduction to obtain a rolled material, which is then diffusion-annealed under appropriate conditions. This results in a clad plate 1C being obtained in which a fourth metal layer 14a having a thickness of TNa, a first metal layer 11 having a thickness of TB, a fourth metal layer 14b having a thickness of TNb, a second metal layer 12 having a thickness of TC, and a third metal layer 13 having a thickness of TA are stacked in this order in the thickness direction (Z direction) and diffusion bonded, with diffusion layers between the fourth metal layer 14a and the first metal layer 11, between the first metal layer 11 and the fourth metal layer 14b, between the fourth metal layer 14b and the second metal layer 12, and between the second metal layer 12 and the third metal layer 13.

[0048] The clad plate 1C shown in FIG. 5 has a first metal layer 11 having fourth metal layers 14 (14a, 14b) on both sides, and a second metal layer 12 and a third metal layer stacked in this order in the thickness direction (Z direction) and diffusion-bonded to the first metal layer 11, with a diffusion layer between the fourth metal layer 14 (14a, 14b) and the first metal layer 11. Except for this configuration, the clad plate 1A and the clad plate 1C have substantially the same configuration. Therefore, for the configuration of the clad plate 1C other than the fourth metal layer 14 (14a, 14b), please refer to the description of Configuration Example A above. Furthermore, if the fourth metal layer 14 (14a, 14b) of the clad plate 1C is made of a fourth metal plate, please refer to the description of Configuration Example B above for the configuration of the fourth metal layer 14.

[0049] When the fourth metal layer 14 (14a, 14b) of the clad plate 1C is formed of a plating film, the fourth metal layer 14 (14a, 14b) is made of a Ni plating film or a Ni alloy plating film. Ni plating films or Ni alloy plating films are generally considered to have corrosion resistance, such as saltwater resistance, similar to Ni plates or Ni alloy plates. Therefore, the clad plate 1C, which includes the fourth metal layer 14 (14a, 14b) of a moderate thickness TN (TNa, TNb) made of a Ni plating film or a Ni alloy plating film, is more advantageous than the clad plate 1A for use in environments such as ports where the atmospheric salt concentration is higher.

[0050] Note that if one surface (Z2 side) of the first metal plate for constituting the first metal layer 11 is masked to form no plating film, and the other surface (Z1 side) is not masked to form a plating film, i.e., if a configuration having the fourth metal layer 14a but not the fourth metal layer 14b is obtained, the configuration will be substantially the same as the clad plate 1B shown in Figure 4. In this case, a step of masking one surface (Z2 side) of the first metal plate for constituting the first metal layer 11 is required. Therefore, when it is desired to obtain substantially the same configuration as the clad plate 1B, it is preferable to adopt the configuration of the clad plate 1B from the viewpoint of omitting the masking step.

[0051] As described above, according to the present invention, it is possible to obtain a clad plate that has good corrosion resistance of the first metal layer (base material) even in applications where the end surfaces are exposed by press processing, etc., and that provides a thermal stress relief effect when heated, such as during seam welding, a lid using this clad plate, and a small component housing package using this lid.

[0052] Next, we attempted to confirm the effectiveness of the clad plate according to the present invention and a lid using the clad plate by predicting thermal stress (equivalent stress) through thermal analysis simulation. The simulation was performed using structural analysis software (ANSYS Mechanical) to model the structure of a package 100 including a lid 1 using a four-layer clad plate having a configuration substantially identical to that of the clad plate 1B shown in FIG. 4 and a case 4 shown in FIGS. 1 and 2 . The package model used was a package commonly referred to as a 3225, with long sides of 3.2 mm and short sides of 2.5 mm. As one of the analysis conditions, the lid temperature at the start of heating was set to 700°C and the case temperature to 25°C, simulating a brazed joint between the lid and the case. Furthermore, the heat transfer coefficient for thermal conduction and heat dissipation after the start of heating was set to 0.5, and a heat dissipation profile was set to cool to 22°C 1500 seconds after the start of heating. The constituent layers, materials, thicknesses, etc. shown in Table 1 were then set, and a clad plate on which a diffusion layer was formed by diffusion annealing was used as a lid using the structural analysis software. The thermal stress (equivalent stress) generated in this lid and case was analyzed, and in particular, the variation in equivalent stress generated on the case side relative to the variation in the thickness TB of the first metal layer and the thickness TC of the second metal layer that constitute the lid was analyzed. At this time, the thicknesses of the first metal layer, the second metal layer, and the third metal layer were set as the boundary of the metal layer within the diffusion layer, with the boundary positioned at the middle of the diffusion layer.

[0053]

[0054] Table 2 shows an example of the results of the above simulation. The inventors particularly considered the simulation results shown in Table 2 and predicted the possibility of defects such as peeling and cracking occurring during brazing of the lid and case based on the trend in the equivalent stress σ (predicted value) generated on the case side. In Table 2, Analyses 1 to 5 are reference examples in which the lid model is a clad plate having a first metal layer made of KV that does not contain Cr. Analysis 6 is a reference example in which the lid model is a clad plate with a smaller TB / TC. Analyses 7 to 9 and 11 and 12 are examples of the present invention in which the lid model is a clad plate made of NRS that contains Cr. Analysis 10 is a reference example in which the lid model is a clad plate that does not have a second metal layer made of Cu.

[0055]

[0056] Analysis 1 is a reference example in which the lid model is composed of a first metal layer made of KV and having a thickness TB of 0.046 mm, a second metal layer made of Cu and having a thickness TC of 0.025 mm, a third metal layer made of BaAs and Ag and having a thickness TA of 0.010 mm, and a fourth metal layer made of Ni and having a thickness TN of 0.005 mm, and the TB / TC ratio is 1.8. In Analysis 1, the equivalent stress σ generated on the case side was predicted to be approximately 0.81 GPa.

[0057] Analysis 2 is a reference example in which the thickness TC of the second metal layer of the lid model in Analysis 1 is changed to 0.017 mm, resulting in TB / TC of 2.7. In Analysis 2, the equivalent stress σ generated on the case side was predicted to be approximately 0.78 GPa.

[0058] Analysis 3 is a reference example in which the thickness TC of the second metal layer of the lid model in Analysis 1 is changed to 0.010 mm, resulting in TB / TC of 4.6. In Analysis 3, the equivalent stress σ generated on the case side was predicted to be approximately 0.78 GPa.

[0059] Analysis 4 is a reference example in which the thickness TC of the second metal layer of the lid model in Analysis 1 is changed to 0.008 mm, resulting in TB / TC of 5.8. In Analysis 4, the equivalent stress σ generated on the case side was predicted to be approximately 0.79 GPa.

[0060] Analysis 5 is a reference example in which the thickness TC of the second metal layer of the lid model in Analysis 1 was changed to 0.000 mm, i.e., the lid model was changed to one without a second metal layer. In Analysis 5, the equivalent stress σ generated on the case side was predicted to be approximately 0.77 GPa.

[0061] Analysis 6 is a reference example in which the lid model is composed of a first metal layer made of NRS with a thickness of 0.046 mm, a second metal layer made of Cu with a thickness of 0.025 mm, a third metal layer made of BaAs and Ag with a thickness of 0.010 mm, and a fourth metal layer made of Ni with a thickness of 0.005 mm, resulting in a TB / TC ratio of 1.8. In Analysis 6, the equivalent stress σ generated on the case side was predicted to be approximately 0.87 GPa.

[0062] Analysis 7 is an example of the present invention in which the thickness TC of the second metal layer of the lid model in Analysis 6 is changed to 0.017 mm, resulting in TB / TC of 2.7. In Analysis 7, the equivalent stress generated on the case side was predicted to be approximately 0.84 GPa.

[0063] Analysis 8 is an example of the present invention in which the thickness TC of the second metal layer of the lid model in Analysis 6 is changed to 0.010 mm, resulting in TB / TC of 4.6. In Analysis 8, the equivalent stress σ generated on the case side was predicted to be approximately 0.84 GPa.

[0064] Analysis 9 is an example of the present invention in which the thickness TC of the second metal layer of the lid model in Analysis 6 is changed to 0.008 mm, resulting in TB / TC of 5.8. In Analysis 9, the equivalent stress σ generated on the case side was predicted to be approximately 0.85 GPa.

[0065] Analysis 10 is a reference example in which the thickness TC of the second metal layer of the lid model in Analysis 6 was changed to 0.000 mm, i.e., the lid model was changed to one without a second metal layer. In Analysis 10, the equivalent stress σ generated on the case side was predicted to be approximately 0.86 GPa.

[0066] Analysis 11 is an example of the present invention in which the thickness TB of the first metal layer of the lid model in Analysis 6 was changed to 0.061 mm, and the thickness TC of the second metal layer was changed to 0.010 mm, resulting in a TB / TC ratio of 6.1. In Analysis 11, the equivalent stress σ generated on the case side was predicted to be approximately 0.85 GPa.

[0067] Analysis 12 is an example of the present invention in which the thickness TB of the first metal layer of the lid model in Analysis 6 was changed to 0.040 mm, and the thickness TC of the second metal layer was changed to 0.010 mm, resulting in a TB / TC ratio of 4.0. In Analysis 12, the equivalent stress σ generated on the case side was predicted to be approximately 0.76 GPa.

[0068] An example of the graph is shown in Figure 6. The graph shown in Figure 6 was created using the thickness TC of the second metal layer and the equivalent stress σ (predicted value) on the case side shown in Table 2. In Figure 6, the plotted points "△" represent the values ​​of analyses 1 to 5 shown in Table 2, and the curve (dashed line) along those points is a quadratic approximation curve σ = 40.197TC calculated from those values. ２ +0.2895TC +0.7739 (coefficient of determination 0.7125). The plotted points "○" represent the values ​​of analyses 6 to 10 shown in Table 2, and the curve (solid line) along these points is a quadratic approximation curve σ = 153.51TC calculated from these values. ２ -3.6009TC + 0.8621 (coefficient of determination 0.8745).

[0069] As shown in Figure 6, in the lid models of analyses 1 to 5, the equivalent stress σ generated on the case side clearly tends to increase as the thickness TC of the second metal layer increases. On the other hand, in the lid models of analyses 6 to 10, the equivalent stress σ generated on the case side clearly tends to decrease as the thickness TC of the second metal layer increases, reach a minimum when TC is between 0.010 mm and 0.014 mm, then reverse, and increase as TC increases. Considering these results, the inventors have derived that when the material constituting the first metal layer of the lid model is replaced from KV to NRS, there is a favorable relationship between the material and thickness TB of the first metal layer constituting the lid and the material and thickness TC of the second metal layer constituting the lid, which minimizes the equivalent stress σ generated on the case side.

[0070] Next, to clarify the configuration that establishes a suitable relationship between the first metal layer and the second metal layer that constitute the lid, the results of Analyses 6 to 9 and Analyses 11 to 12 shown in Table 2 were considered. Specifically, the ranges of the thickness TB of the first metal layer and the thickness TC of the second metal layer were set to be suitable for the above-mentioned clad plate (lid) configuration. That is, TB was set to 0.015 mm or more and 0.080 mm or less, and TC was set to 0.005 mm or more and 0.020 mm or less. Furthermore, using the results of Analyses 6 to 9 and Analyses 11 to 12, the relationship between TB / TC and the equivalent stress σ generated on the case side was approximated. That is, a quadratic approximation curve σ = 0.0143(TB / TC) ２ The equation was calculated as -0.1159 (TB / TC) + 1.0369 (coefficient of determination 0.5592). Then, using this quadratic approximation curve, TB and TC were given, as shown in Table 3, and the value of the input independent variable TB / TC was calculated, and the value of the dependent variable σ was output.

[0071]

[0072] Furthermore, the graph shown in Figure 7 was created using the results of analyses 6 to 9 and 11 to 12 shown in Table 2 and analyses 13 to 16 shown in Table 3. In Figure 7, the curve (solid line) along the plotted points "○" is a quadratic approximation curve σ = 0.0143 (TB / TC) calculated from the numerical values. ２ -0.1163 (TB / TC) + 1.0375 (coefficient of determination 0.9981).

[0073] As described above, when brazing a lid to a case using a clad plate, if the thermal stress (equivalent stress) acting on the case due to thermal stress exceeds 2.0 GPa, the probability of delamination and cracking increases. Furthermore, as described above, in a configuration where TB / TC is less than 2.0, the thickness TC of the second metal layer is relatively insufficient relative to the thickness TB of the first metal layer, and the thermal stress reduction effect may not be achieved. The quadratic approximation curve predicts that σ when TB / TC is 2.0 will be approximately 0.86 GPa. From this perspective, the range enclosed by the two-dot chain line in Figure 7 is predicted to be a safe region. From this prediction, the inventors have concluded that a lid using a clad plate having a TB / TC within the safe region shown in Figure 7 is likely to reduce the probability of delamination and cracking. That is, the present invention relates to a clad plate having TB of 0.015 mm or more and 0.080 mm or less, TC of 0.005 mm or more and 0.020 mm or less, and TB / TC of 2.0 or more and 12.0 or less, and a lid using the clad plate.

[0074] Furthermore, when considering variations in predicted values ​​and errors, a safer region should exist within the safe region shown by the two-dot chain line in FIG. 7 . For example, if the equivalent stress σ generated on the case side were approximately 1.7 GPa, which is a 15% reduction from the above-mentioned 2.0 GPa, the probability of occurrence of peeling or cracking would be more likely to be reduced. From this perspective, the range surrounded by the dashed line in FIG. 7 is predicted to be a safer region. From this prediction, the inventors have concluded that a lid using a clad plate having a TB / TC within the safer region shown in FIG. 7 is more likely to reduce the probability of occurrence of peeling or cracking. That is, a clad plate and a lid using such a clad plate in which TB is 0.015 mm or more and 0.080 mm or less, TC is 0.005 mm or more and 0.020 mm or less, and TB / TC is 2.0 or more and 12.0 or less. According to the quadratic approximation curve, when TB / TC is 12.0, σ is predicted to be about 1.7 GPa.

[0075] Furthermore, a sufficiently safe region should exist within the safer region indicated by the dashed line in Figure 7. For example, if the equivalent stress σ generated on the case side is reduced by about 25% from the above-mentioned 2.0 GPa to about 1.5 GPa, the probability of occurrence of peeling or cracking will be sufficiently reduced. That is, a clad plate and a lid using the clad plate in which TB is 0.015 mm or more and 0.080 mm or less, TC is 0.005 mm or more and 0.020 mm or less, and TB / TC is 2.0 or more and 12.0 or less. Note that, using the above quadratic approximation curve, σ is predicted to be about 1.5 GPa when TB / TC is 11.0.

[0076] A clad plate 1A was obtained, which corresponds to Analysis 8 (Example of the Invention) shown in Table 2 and Analysis 3 (Reference Example) shown in Table 2. The clad plate 1A is composed of a first metal layer 11 having a thickness of TB, a second metal layer 12 having a thickness of TC, and a third metal layer 13 having a thickness of TA, stacked in this order in the thickness direction (Z direction) and diffusion-bonded, with diffusion layers between the first metal layer 11 and the second metal layer 12 and between the second metal layer 12 and the third metal layer 13. Next, a salt spray test was conducted to confirm that the corrosion resistance of the first metal layer of the clad plate according to the present invention and a lid using the clad plate are excellent even in applications where the end faces are exposed by press processing or the like. The salt spray test was conducted in accordance with JIS Standard C0023:1989 (Environmental Testing Methods (Electrical and Electronic) Salt Spray Test Method). Specifically, salt spray was continuously performed on specimens 1 and 2 for 48 hours in an environment of a temperature of 35±2°C, a salt concentration of 5±1%, and a pH of 6.5 to 7.2. Specimen 1 was cut out from a clad plate prototype corresponding to analysis 8 (invention example) shown in Table 2. Specimen 2 was cut out from a clad plate prototype corresponding to analysis 3 (reference example) shown in Table 2. The dimensions of specimens 1 and 2 were both 3.2 mm long, 2.5 mm short, and 0.071 mm thick.

[0077] As a result of the salt spray test, no corrosion (rust) was confirmed in specimen 1 by visual inspection after 48 hours of salt spray. On the other hand, in specimen 2, corrosion (rust) that is presumed to have progressed from the edge and spread to approximately half of the surface was confirmed by visual inspection after 24 hours of salt spray. Furthermore, in specimen 2, corrosion (rust) that is presumed to have spread over approximately the entire surface was confirmed by visual inspection after 48 hours of salt spray. From these results, it was confirmed that specimen 1, which was cut out from a clad plate prototype corresponding to analysis 8 (example of the present invention) shown in Table 2, has sufficient saltwater resistance.

[0078] From the above, it has been confirmed that, according to this invention, it is possible to obtain a clad plate having a first metal layer (substrate) with good corrosion resistance even in applications where the end faces are exposed by press processing, a lid using this clad plate, and a small component housing package using this lid.

[0079] The clad plate according to the present invention, a lid using the clad plate, and a package including the clad plate and the lid, can provide a thermal stress relief effect during heating by seam welding, thereby suppressing peeling at the bonding surface between the lid and the ceramic case and damage to the small component housing package, and maintaining hermetic sealing. This was confirmed by a temperature cycle test and a pressure cooker test (PCT). Specifically, a clad plate 1A was obtained, which was composed of a first metal layer 11 having a thickness TB, a second metal layer 12 having a thickness TC, and a third metal layer 13 having a thickness TA, which were stacked in this order in the thickness direction (Z direction) and diffusion-bonded, with diffusion layers between the first metal layer 11 and the second metal layer 12 and between the second metal layer 12 and the third metal layer 13. The clad plate 1A was then machined and mounted on a ceramic case, commonly referred to as 3225, with a long side of 3.2 mm and a short side of 2.5 mm, and the resulting lid was sealed by seam welding to obtain a small component package according to the present invention. These small component packages were subjected to a 250-cycle temperature cycle test, consisting of a low-temperature condition of -40°C for 30 minutes and a high-temperature condition of 125°C for 30 minutes, followed by a helium leak test. The resulting small component packages were then examined for peeling at the interface between the lid and the ceramic case and for damage to the package. Furthermore, the resulting small component packages were subjected to PCT at an ambient temperature of 120°C, 100% humidity, and 2 atmospheres (0.2 MPa) for 96 hours to examine for peeling at the interface between the lid and the ceramic case and for damage to the package.

[0080]

[0081] The temperature cycle test results confirmed that the small component packages sealed with the lids of Samples 1 and 2, which are examples of the present invention, maintained their airtight seal without leaking even after 250 cycles of low-temperature conditions (-40°C for 30 minutes and high-temperature conditions (125°C for 30 minutes)). Furthermore, the small component packages sealed with the lids of Samples 1 and 2, which are examples of the present invention, did not experience any peeling at the interface between the lid and the ceramic case, and were not damaged even after the temperature cycle test. Furthermore, the PCT results confirmed that the small component packages sealed with the lids of Samples 1 and 2, which are examples of the present invention, did not experience any peeling at the interface between the lid and the ceramic case, and were not damaged even after being exposed to a high-temperature, high-humidity environment (ambient temperature 120°C, humidity 100%, 2 atmospheres (0.2 MPa) for 96 hours).

[0082] From the above, it has been confirmed that according to the present invention, it is possible to obtain a clad plate that has the effect of alleviating thermal stress during heating such as seam welding, a lid using the clad plate, and a small component housing package using the lid.

[0083] 1: Clad plate, lid (airtight sealing cover material) 2: Small component 3: Storage space 4: Case (ceramic case) 5: Wire bonding 11: First metal layer 12: Second metal layer 13: Third metal layer 14: Fourth metal layer 100: Package (small component storage package)

Claims

1. Made of an Fe alloy containing Ni and Cr, with a thermal expansion coefficient of 5.0 x 10 －６ / K or more 15.0×10 －６ / K or less and having a thickness of TB; and a first metal layer made of Cu or a Cu alloy and having a thermal expansion coefficient of 16.0 × 10 －６ / K or more 21.0×10 －６ / K or less, and a thermal conductivity of 100 W / (m K) or more and 400 W / (m K) or less, and a thickness of TC; and a third metal layer made of an Ag alloy containing Ag and Cu, wherein diffusion layers are present between the first metal layer and the second metal layer and between the second metal layer and the third metal layer, and the TB is 0.015 mm or more and 0.080 mm or less, the TC is 0.005 mm or more and 0.020 mm or less, and the TB / TC is 2.0 or more and 12.0 or less.

2. The clad plate according to claim 1, further comprising a fourth metal layer made of Ni or a Ni alloy, with diffusion layers between the fourth metal layer and the first metal layer, between the first metal layer and the second metal layer, and between the second metal layer and the third metal layer.

3. A hermetic sealing lid material made of a clad plate that seals a small component incorporating an electronic circuit in the package storage space by brazing to a ceramic case that defines the storage space, wherein the clad plate is made of an Fe alloy containing Ni and Cr and has a thermal expansion coefficient of 5.0 x 10 －６ / K or more 15.0×10 －６ / K or less and having a thickness of TB; and a first metal layer made of Cu or a Cu alloy and having a thermal expansion coefficient of 16.0×10 －６ / K or more 21.0×10 －６ / K or less, and a thermal conductivity of 100 W / (m K) or more and 400 W / (m K) or less and a thickness of TC; and a third metal layer made of an Ag alloy containing Ag and Cu, wherein diffusion layers are present between the first metal layer and the second metal layer and between the second metal layer and the third metal layer, and the TB is 0.015 mm or more and 0.080 mm or less, the TC is 0.005 mm or more and 0.020 mm or less, and the TB / TC is 2.0 or more and 12.0 or less.

4. The hermetic sealing lid material according to claim 3, wherein the clad plate further includes a fourth metal layer made of Ni or a Ni alloy, and has diffusion layers between the fourth metal layer and the first metal layer, between the first metal layer and the second metal layer, and between the second metal layer and the third metal layer.

5. A package comprising a small component incorporating an electronic circuit, a housing space for the small component, a ceramic case defining the housing space, and a hermetically sealing lid made of a clad plate that seals the small component in the housing space by brazing to the ceramic case, wherein the clad plate is made of an Fe alloy containing Ni and Cr and has a thermal expansion coefficient of 5.0 x 10 －６ / K or more 15.0×10 －６ / K or less and having a thickness of TB; and a first metal layer made of Cu or a Cu alloy and having a thermal expansion coefficient of 16.0×10 －６ / K or more 21.0×10 －６ / K or less, and a thermal conductivity of 100 W / (m·K) or more and 400 W / (m·K) or less and a thickness of TC; and a third metal layer made of an Ag alloy containing Ag and Cu, wherein diffusion layers are present between the first metal layer and the second metal layer and between the second metal layer and the third metal layer, and the TB is 0.015 mm or more and 0.080 mm or less, the TC is 0.005 mm or more and 0.020 mm or less, and the TB / TC is 2.0 or more and 12.0 or less.

6. The miniature component housing package according to claim 5, wherein the clad plate further includes a fourth metal layer made of Ni or a Ni alloy, and has diffusion layers between the fourth metal layer and the first metal layer, between the first metal layer and the second metal layer, and between the second metal layer and the third metal layer.

Images