JP7004191B2 - Airtight sealing cap and electronic component storage package - Google Patents

Description

The present invention relates to an airtight sealing cap and an electronic component storage package.

For example, a surface acoustic wave (SAW) filter used for noise removal of mobile phones, and a surface mount device (SMD: Surface Mount Device) used for airtight sealing of electronic components such as crystal oscillators and oscillators. Many electronic component storage packages, such as packages, that contain electronic components inside and are hermetically sealed are used. In such an electronic component storage package, a lid material (cap for airtight sealing) is joined (airtightly sealed) to a ceramic case (electronic component storage member) for accommodating electronic components inside by using solder or the like. .. In such an airtight sealing cap, a Ni (nickel) plating layer is formed on the surface of a low thermal expansion metal plate as a base material, and an Au (gold) plating layer is formed on the surface of the Ni plating layer. A bonding region for airtight sealing is set on the surface of the plating layer, and a solder layer is formed on the surface of the bonding region (see Patent Documents 1 and 2).

The Au plating layer in the airtight sealing cap is effective for appropriately wetting and spreading the molten solder in the bonding region set on the surface of the Au plating layer while being suppressed by the surface tension. However, if the wet spread of the molten solder on the surface of the Au plating layer is too good, the molten solder may deviate from the joint region and spread inward, and further wet and spread toward the inside of the electronic component storage member. be. In this case, not only the amount of solder required for airtight sealing in the joint region is insufficient, but also contamination of electronic parts by soldering and poor airtightness of the electronic component storage package are likely to occur. An oxide region (oxide layer) that is inferior in wettability to the molten solder is formed inside the joint region against excessive wetting and spreading from the joint region of the molten solder toward the inside of the electronic component storage member, and the molten solder is formed by the oxide region. A means for preventing the spread of solder has been proposed (see Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 9-199622 International Publication No. 2007/09/284

By the means for forming the oxide region (oxide layer) described above, it has become possible to prevent excessive wet spread of the molten solder toward the inside of the joint region. However, in recent years, there has been a demand for countermeasures against poor appearance of the electronic component storage package caused by excessive wetting and spreading of the molten solder from the joint region to the outside of the electronic component storage member. Specifically, it is a phenomenon in which the molten solder deviates from the joint region and spreads wet to the outside (side surface of the metal plate), and further wets and spreads beyond the side surface of the metal plate to the surface opposite to the joint region. As a result, solder adheres to the outer surface of the airtight sealing cap, which is the outer surface of the electronic component storage package, and the adhesion of the solder causes an appearance defect. Excessive wet spread from the bonded region of the molten solder to the outside causes the above-mentioned poor appearance of the electronic component storage package, and the amount of solder required for airtight sealing is insufficient in the bonded region, resulting in poor airtightness of the electronic component storage package. Is more likely to occur.

An object of the present invention is to suppress the wet spread from the joint region of the molten solder to the outside when the airtight sealing cap used for the electronic component storage package is bonded to the electronic component storage member by soldering, and the appearance of the package is suppressed. It is to provide an airtight sealing cap capable of suppressing defects and airtightness defects, and to provide a highly reliable electronic component storage package by using the cap.

The present inventor has particularly investigated the function and characteristics of the Au plating layer in the conventional airtight sealing cap, and found that the Au content in the Au plating layer affects the wet and spread form of the molten solder. I came up with it.

That is, the airtight sealing cap of the present invention is used for an electronic component storage package having a Ni plating layer formed on the surface of a metal plate and an Au plating layer formed on the Ni plating layer. In the cap, the Au plating layer has a bonding region with other members, and the bonding region has an Au content ratio of 2.0 % by mass to 10.0 % by mass according to surface element analysis, and the bonding is described. It has a solder layer formed in an annular shape on the surface of the region, and the ratio L / T of the solder layer to the thickness T of the metal plate of the wet spread length L in the thickness direction of the metal plate is 30%. It is characterized by the following .

It is preferable to have a solder layer of Au—Sn based alloy on the surface of the bonding region.
It is preferable to have an oxidation region inside the junction region.

The electronic component storage package can be obtained by using the airtight sealing cap of the present invention described above.
That is, the electronic component storage package of the present invention is characterized in that the airtight sealing cap according to any one of the present invention and the electronic component storage member in which the electronic component is housed are joined by soldering.
It is preferable that the solder is an Au—Sn based alloy.

The airtight sealing cap of the present invention can suppress the wetting and spreading of the molten solder toward the outside of the joint region with other members. Therefore, the occurrence of poor appearance and poor airtightness of the electronic component storage package is suppressed.

It is a structural example of the airtight sealing cap of this invention, and is the figure which shows the cross section in which the bonding area S1 is set. It is a structural example of the airtight sealing cap of this invention, and is the figure which shows the cross section which has the solder layer 5 on the surface of the bonding area S1. It is a structural example of the airtight sealing cap of this invention, and is the figure which shows the cross section which has the oxidation area S2 inside the bonding area S1. In the configuration example of the electronic component storage package of the present invention, the airtight sealing cap shown in FIG. 3 and the electronic component storage member configured by using the ceramic substrate 21 or the like are joined by the solder layer 5'. It is a figure which shows the cross section. It is a figure which shows the manufacturing method of the electronic component storage package shown in FIG. It is sectional drawing which shows the specific example in which the molten solder wets and spreads to the side surface at the time of forming the solder layer 5 on the bonding area S1. It is a figure which showed the cubic polymorphic approximation curve obtained based on each numerical value in the scatter plot which made the numerical value of Au content ratio as the horizontal axis, and the numerical value of ratio L / T as the vertical axis.

The airtight sealing cap of the present invention is used for an electronic component storage package (hereinafter referred to as "package"), and is joined to an electronic component storage member (hereinafter referred to as "case") in which electronic components are stored therein. It is an airtight sealing cap (hereinafter referred to as "cap").

An example of the structure of the cap of the present invention is shown in FIG. The cap 1 shown in FIG. 1 is based on a metal plate 2 formed by means such as press punching using an alloy plate such as Fe-42Ni-based, Fe-42Ni-6Cr-based, or Fe-Ni—Co-based. Use as a material. Further, on the surface of the metal plate 2, there is a Ni plating layer 3 formed by Ni plating so that the metal plate 2 is surrounded by Ni or a Ni alloy. Further, on the surface of the Ni plating layer 3, there is an Au plating layer 4 formed by Au plating so that the Ni plating layer 3 is surrounded by Au or an Au alloy. Further, on the surface of the Au plating layer 4, there is a bonding region S1 to be bonded to the case.

The joining region S1 is a region for joining to the case using solder when manufacturing the package, and is an important region that affects the airtight sealability of the package. Further, the joint region S1 is generally annular and corresponds to the shape of the outer periphery of the metal plate 2. For example, when the outer periphery of the metal plate 2 is angular, it is set to an annular square shape similar to this. Will be done.

When the cap 1 shown in FIG. 1 is bonded to the case using solder, it is generally performed to form the solder layer 5 in advance in the bonding region S1 of the Au plating layer 4 of the cap 1 as shown in FIG. There is. The solder layer 5 is formed in an annular shape corresponding to the shape of the joint region S1. For example, a method in which a solder washer placed in the joint region S1 is melted and then solidified and fixed (hereinafter referred to as “melt fixing method”). Is simple. The solder layer 5 is melted by heating at the time of joining to become molten solder, and spreads wet in the joining region S1. In the molten solder, the bonding region S1 of the cap 1 and the bonding region on the case side are brought into close contact with each other, and the combined solder is subsequently solidified to bond the two to airtightly seal the package. When the solder layer 5 is fused onto the surface of the Au plating layer 4, if Au in the Au plating layer 4 is diffused in the solder layer 5, the bonding strength is expected to be improved. Therefore, in consideration of the ease of diffusion of Au, it is preferable to use an Au—Sn-based alloy for the solder layer 5.

The surface roughness, waviness, contamination, and oxidation properties of the bonding region S1 of the Au plating layer 4 (hereinafter referred to as "surface texture") are determined when the solder layer 5 is formed by the above-mentioned melt solidification method. When the cap 1 and the case are hermetically sealed, the wet spread of the molten solder is greatly affected. Therefore, it is important that the surface texture of the bonding region S1 is appropriately formed. Therefore, in the present invention, the Au content ratio of the joint region S1 of the cap 1 by surface element analysis is set to 1.0% by mass to 13.0% by mass. The Au content ratio by surface element analysis of the bonding region S1 can be adjusted when the Au plating layer 4 is formed on the Ni plating layer 3 described above. Specific examples of such adjustment will be described later.

In the present invention, the surface element analysis is intended for energy dispersive X-ray spectroscopy (EDX) attached to a scanning electron microscope (SEM). In such SEM-EDX, the electron beam irradiated to the subject (the surface to be measured of the junction region S1) permeates the Au plating layer 4 or further penetrates the Ni plating layer 3, and the characteristic X-rays permeate the Au plating layer. 4. Generated from the Ni plating layer 3 and the metal plate 2. Therefore, the types of elements and their content ratios obtained by spectroscopically determining characteristic X-rays are affected by the thickness of the Au plating layer 4 and the Ni plating layer 3. Therefore, the balance ( 98.0 % by mass to 90.0 % by mass) excluding the Au content ratio ( 2.0 % by mass to 10.0 % by mass) of the above-mentioned bonding region S1 by SEM-EDX is the Au plating layer 4. , Ni plating layer 3, and the total value of the content ratios of other elements excluding Au contained in the metal plate 2.

The cap 1 having an Au content ratio in the range of 2.0 % by mass to 10.0 % by mass by surface elemental analysis of the bonding region S1 is suitable for wet spreading of molten solder in the bonding region S1. Specifically, the molten solder suppresses a phenomenon in which the molten solder deviates from the inside or the outside of the joint region S1 and excessively wets and spreads while wet and spreads in the annular joint region S1. Therefore, when the solder layer 5 is formed by the melt solidification method, the molten solder is necessary and sufficiently wet and spreads in the joint region S1, and when the cap 1 and the case are airtightly sealed, the inside of the joint region S1 is formed. It is possible to secure a necessary and sufficient amount of solder. When the Au content ratio of the joint region S1 of the cap 1 is within the above range, it is not clear why the surface texture becomes appropriate due to the wet spread of the molten solder.

The Au content ratio of the bonding region S1 of the cap 1 by surface elemental analysis is preferably 6.0% by mass to 10.0% by mass. With this configuration, it is easy to obtain suitable wet spreading of the molten solder in the joint region S1, and it is easy to preferably suppress the deviation of the molten solder to the inside or the outside of the joint region S1.

Further, as shown in FIG. 3, it is preferable to have the oxide region S2 inside the joint region S1 of the cap 1, and the oxide region S2 more reliably suppresses the wet spread of the molten solder toward the inside of the joint region S1. be able to. The oxidation region S2 can be formed by, for example, irradiating a laser beam using YVO4 (Yttrium Vanadium tera Oxide) as a medium and removing a part of the Au plating layer 4 in a ring shape. The laser beam melts and removes the Au plating layer 4 by heat, and also oxidizes the surface of the Ni plating layer 3. Therefore, the oxidation region S2 is an oxide layer in which the surface of the Ni plating layer 3 is oxidized.

By using the cap 1 of the present invention described above, it is possible to obtain the package of the present invention in which electronic components are housed.
FIG. 4 shows an example of the configuration of the package of the present invention. In the package 10 shown in FIG. 4, as shown in FIG. 5, the cap 1 and the case 20 in which the electronic component 30 is housed are joined to each other via the solder layer 5', and the inside is hermetically sealed. There is. In this configuration example, the cap 1 has the same form as that shown in FIG. Further, the case 20 includes a ceramic substrate 21 formed of an insulating material such as alumina and an annular ceramic frame 22 formed of an insulating material such as alumina, and is a flat surface of the ceramic substrate 21. And the outer peripheral wall of the ceramic frame 22 constitutes a space for accommodating the electronic component 30. Further, a tungsten layer 23 is provided on the upper surface of the annular ceramic frame 22. A Ni—Co alloy layer 24 is provided on the upper surface of the tungsten layer 23. An Au layer 25 (see FIG. 5) formed by using Au or an Au alloy is provided on the upper surface of the Ni—Co alloy layer 24. Further, the electronic component 30 is, for example, a crystal oscillator, and is arranged on the ceramic substrate 21 via the bump 31 in the space of the case 20.

The cap 1 and the case 20 described above are joined by using solder. Specifically, as shown in FIG. 5, the surface of the Au layer 25 on the case 20 side and the surface of the solder layer 5 on the cap 1 side are brought into close contact with each other as shown by arrows. Next, the solder layer 5 is melted in an atmosphere as close to vacuum as possible at a temperature of 280 ° C. to 310 ° C. to generate molten solder, and the molten solder is held in the joint region S1 until it is necessary and sufficiently wet and spread. .. After that, the temperature is lowered to solidify the molten solder, so that the cap 1 and the case 20 can be joined.

The joint region S1 of the cap 1 where the molten solder wets and spreads is formed with a surface texture suitable for the wet and spread of the molten solder, that is, the Au content ratio by surface elemental analysis is 2.0 % by mass to 10.0 % by mass. .. As a result, the molten solder is smoothly wetted and spread in the joint region S1 and is filled, and the wet and spread of the molten solder deviating to the outside or the inside of the joint region S1 can be suppressed to a predetermined value or less. Therefore, the appearance defect of the package 10 due to the wet spread to the outside deviating from the joint region S1 of the molten solder is suppressed. Further, the deterioration of the characteristics of the electronic component 30 due to the inward wetting and spreading that deviates from the bonding region S1 of the molten solder is suppressed. In addition, as shown in FIG. 4, by providing the cap 1 with an oxidation region S2 in which the wettability and spreading property of the molten solder is reduced by oxidation of the surface, the cap 1 is provided with an inward wetting region that deviates from the bonding region S1 of the molten solder. Defects in characteristics of the electronic component 30 due to spreading are more reliably suppressed. Further, as a result of suppressing excessive wetting and spreading of the molten solder, the thickness and width of the solder layer 5 may be reduced by the amount of the suppression, and the amount of solder used can be reduced.

In the process of re-solidifying after the solder layer 5 described above becomes molten solder, the Au plating layer 4 and the Au layer 25 diffuse into the solder layer 5. Such diffusion tends to increase the bonding strength due to soldering. Therefore, it is preferable to use an Au—Sn-based alloy for the solder layer 5, and the solder layer 5 and the Au plating layer 4 can be easily adapted, and similarly, the solder layer 5 and the Au layer 25 can be easily adapted. Can be done. Due to such diffusion, it becomes difficult to distinguish the solder layer 5 after being bonded to the case 20 from the Au plating layer 4 and the Au layer 25. Therefore, in the solder layer 5 after joining, apparently, on the case 20 side, the solder layer 5'is formed on the surface of the Ni—Co alloy layer 24 as shown in FIG. Further, on the cap 1 side, the solder layer 5'is formed on the surface of the Ni plating layer 3, but for convenience of explanation, the Au plating layer 4 and the solder layer 5'are clearly separated in FIG. Is shown.

(Example 1)
With reference to the configuration shown in FIG. 1, caps 1 having different Au content ratios by SEM-EDX (surface elemental analysis) of the bonding region S1 of the Au plating layer 4 are produced, and deviate from the bonding region S1 to the outside or the inside. We evaluated the wet and spread state of the molten solder. In such SEM-EDX, the EDX (model: Emax xact) manufactured by HORIBA, Ltd. attached to the SEM (model: S-3400N) manufactured by Hitachi High-Technologies Corporation is used, the acceleration voltage is 15 kV, the working distance is 10 mm, and the collection coefficient. The ratio was set to 2 to 3 kpcs, and the bonding region S1 of the cap 1 to be the subject (in the case of the cap 1 having the Au plating layer 4 on the entire surface, the central portion thereof may be the central portion) was enlarged by 500 times, approximately 180 μm × 250 μm. The area of was analyzed by surface, and the obtained value was used as the detected value. For the sake of simplicity, the names and numbers of the parts shown in each figure will be quoted in the description of the first embodiment.

The metal plate 2 (length 1.58 mm, width 1.18 mm, thickness 0.06 mm), which is the base material of the cap 1, is made by pressing a plate made of Fe-29% Ni-17% Co alloy (mass%). It was made by pulling it out. Next, the surface of the metal plate 2 was covered with a Ni plating layer 3 (average thickness 1.98 μm) containing Ni as a main component by a Ni plating treatment to form a Ni-plated metal plate. Subsequently, by the Au plating treatment, the surface of the Ni-plated metal plate was coated with the Au plating layer 4 whose main component was Au to form an Au-plated metal plate. Further, the vicinity of the outer periphery of the Au-plated metal plate having the Au-plated layer 4 on the outermost surface and the Ni-plated layer 3 between the Au-plated layer 4 and the metal plate 2 is the annular bonding region S1.

In the Au plating treatment, an electroplating method was applied. Specifically, a plating solution containing Au potassium cyanide, which is a source of Au, having a pH of about 5 to 6 is prepared, and the Au concentration in the plating solution is adjusted to 0.5 g / L to 2.0 g / L. It was adjusted. Further, the temperature (liquid temperature) of the plating solution was controlled to 30 ° C. ± 5 ° C. for the purpose of stabilizing the precipitation rate of Au and suppressing the variation in the precipitation amount of Au. The Ni-plated metal plate whose surface has been cleaned is put into the plating solution, the current density at the time of energization is controlled to 0.01 ± 0.005 A / dm ² , and the Au plating layer including the bonding region S1 is included. The energization time was controlled so that the Au content ratio of 4 became a predetermined value. The energization time was variously adjusted to change the Au content ratio on the surface of the Au plating layer 4, that is, the Au content ratio in the bonding region S1 of the Au plating layer 4. In this way, the cap 1 (hereinafter referred to as FIG. 1) as shown in FIG. 1 before the metal plate 2 is used as the base material, the Ni plating layer 3 is used as the base, the Au plating layer 4 is provided on the outermost surface, and the solder layer 5 is provided in the bonding region S1. A "non-solder cap" was obtained to distinguish it from caps of other configurations.

Next, the solder layer 5 was formed on the joint region S1 of the non-solder cap by the melt fixing method. Specifically, a solder-free cap is arranged so that the bonding region S1 is on the upper surface in the vertical direction, and a solder washer (width 0.10 mm) formed in an annular shape on the surface of the Au plating layer 4 corresponding to the bonding region S1. (Thickness 0.015 mm) was placed, and in that state, it was placed in a furnace and heated to melt the solder washer and then sufficiently cooled. The solder washer was formed by using an Au-22.4 mass% Sn-based alloy. As a result, the cap 1 having the configuration shown in FIG. 2 (hereinafter, referred to as “soldered cap” to distinguish it from the caps having other configurations) could be obtained. Further, since the solder layer 5 formed on the joint region S1 of the soldering cap is melted and solidified in a state where surface tension is applied, the cross-sectional shape in the thickness direction is formed in an arc shape as shown in FIG. To. Note that FIG. 6 is an enlarged observation example of a cut surface obtained by cutting a soldered cap having a solder layer 5 formed in an annular shape on the joint region S1 of the solderless cap in the thickness direction of the metal plate 2.

The Au content ratio was measured by EDX for the joint region S1 of the solder-free cap before forming the solder layer 5 produced by the above-mentioned manufacturing method, and the thickness of the Au plating layer 4 was measured by a film thickness meter. When the solder layer 5 is formed on the joint region S1 of the non-solder cap to obtain a soldered cap, the solder layer 5 becomes molten solder, and a dotted line is shown in FIG. 6 according to the surface properties of the joint region S1 and the Au plating layer 4. As in the region S3 surrounded by, it is common that the region deviates from the joint region S1 and spreads wet toward the outside (side surface). Taking this into consideration, the wetting and spreading length (L in FIG. 6) of the molten solder deviating from the joint region S1 and going outward was measured, and the thickness T (in FIG. 6) of the metal plate 2 having the length L was measured. The ratio L / T to the indicated T) was determined as a percentage. The thickness T is 0.06 mm.

These results are grouped based on the Au content ratio of the junction region S1, and all of them are shown in Table 1 as average values. The numerical values shown in Table 1 with respect to the bonding region S1 are the results of analysis of the solder-free cap. The numerical values shown in Table 1 regarding the wet spread of the molten solder are the results of melting and solidifying the solder layer 5 of the soldering cap. If the ratio L / T related to the wet spread toward the outside (side surface) deviating from the joint region S1 of the molten solder with respect to the thickness T of the metal plate 2 is approximately 40% or less, the package is determined to have a poor appearance. Is unlikely. Further, when the ratio L / T is about 1/3, which is 35% or less, the possibility that the package is judged to have a poor appearance is particularly small, so that there is no practical problem and it is preferable. Taking this into consideration, the effectiveness of the present invention was evaluated by the ratio L / T, the threshold value was set to 40%, the preferable threshold value was set to 35%, and the more preferable threshold value was set to 30%.

From Table 1, in groups 1 to 3 (example of the present invention) in which the Au content ratio of the bonding region S1 was 2.0 % by mass to 10.0 % by mass, the maximum value of the ratio L / T was 26.65 % (). Group 1 ), which was less than the more preferable threshold of 30 % . On the other hand, in groups 4 to 7 (comparative example) in which the Au content ratio of the junction region S1 exceeded 10.0 % by mass, the ratio L / T of groups 5 and 7 exceeded the threshold value of 40%, and the group was smaller than these. Even 4 and 6 exceeded the more preferable threshold value ( 30 %) .

Further, from the magnitude relationship of the Au content ratios of Groups 3 and 4, when the Au content ratio is 10.0% or less, the ratio L / T tends to be a more preferable threshold value of 30% or less. From the magnitude relationship of the Au content ratios of groups 1 and 2, it is observed that the ratio L / T tends to increase as the Au content ratio decreases. Therefore, the molten solder gets wet due to the decrease in the Au content ratio of the bonding region S1. Spreading instability is presumed. Taking this into consideration, it can be understood that the preferable Au content ratio is 3.0% or more, more preferably 4.0% or more, and even more preferably 6.0% or more.

As another viewpoint, a scatter plot was prepared and evaluated based on the Au content ratio and the ratio L / T shown in Table 1. FIG. 7 shows a diagram (graph) in which a cubic polynomial approximation curve is also shown in such a scatter diagram. In addition to the results in Table 1, the tendency shown in FIG. 7 was taken into consideration to determine the preferable range of the Au content ratio of the junction region S1. For example, when the Au content ratio of the joint region S1 is 1.0% by mass to 13.0% by mass, the ratio L / T is set to a threshold of 40% for the wet spread that deviates from the joint region S1 of the molten solder and goes outward. It can be seen that it can be easily suppressed as follows. Further, when the Au content ratio of the bonding region S1 is 2.0% by mass to 10% by mass, there is a possibility that it can be suppressed to a more preferable threshold value of 30% or less.

Further, when it is desired to make the ratio L / T as small as possible, when the Au content ratio of the junction region S1 is 3.0% by mass to 8.0% by mass, the ratio L / T is set to a more preferable threshold value of 30% or less. It becomes easy to suppress, and there is a possibility that it can be further suppressed to a more preferable threshold value of 20% or less. Further, when the thickness of the Au plating layer 4 becomes small, the risk of occurrence of a defect (plating unevenness) in which the Ni plating layer 3 is partially exposed increases. Therefore, while suppressing the ratio L / T to a more preferable threshold value of 30% or less. However, when it is desired to reduce the risk of plating unevenness, it is preferable that the Au content ratio of the bonding region S1 is 6.0% by mass to 10.0% by mass.

Next, targeting groups 1 to 3 (example of the present invention), the bonding region of the molten solder was observed by observing the plane of the subject in which the solder of the soldering cap was melted and solidified and observing the cross section as shown in FIG. It was confirmed that the wet and spread state deviated from S1 and went inward. As a result, solder sometimes adhered to the surface of the inner Au plating layer 4 that deviated from the bonding region S1 (not shown). It is presumed that this is because the molten solder deviates from the joint region S1 and wets and spreads inward due to the melting of the solder washer. However, since the amount of solder adhering to each of them was very small, even if such a small amount of solder was remelted inside the case 20 when the package 10 was manufactured, the electronic component 30 would have a characteristic defect. It turned out that it can be used without any problem.

From the above, the bonding region S1 of groups 1 to 3 (example of the present invention) is necessary in the bonding region S1 while suppressing the wet spread toward the outside or the inside of the bonding region S1 of the molten solder to a predetermined value or less. It was confirmed that the surface texture was sufficiently wet and spread. Further, it was confirmed that the bonding region S1 of the groups 4 to 7 (comparative example) has a surface texture that deviates from the bonding region S1 of the molten solder and has a surface texture exceeding a threshold value of 30% , which is more preferable for wet spreading outward.

Next, using the solder caps of Groups 1 to 3 (example of the present invention), a package 10 having the configuration shown in FIG. 4 was produced by the manufacturing method described with reference to FIG. As a result, when the solder layer 5 is remelted and bonded to the case 20, the molten solder deviates from the bonding region S1 and wets and spreads to the outside (side surface of the soldering cap). No poor appearance was observed. Similarly, using the solder caps of groups 4 to 7 (comparative example), a package 10 having the configuration shown in FIG. 4 was produced. As a result, when the solder layer 5 is remelted and bonded to the case 20, the molten solder deviates from the bonding region S1 and spreads wet to the outside (side surface of the soldering cap), and the ratio L / T is a more preferable threshold value 30. There was a package 10 that exceeded% and had a poor appearance.

(Example 2)
Oxidation region S2 was formed with respect to the solderless caps of groups 1 to 3 (example of the present invention) having the configuration shown in FIG. 1 produced in Example 1 with reference to FIG. 3, and the bonding region S1 was separated inward. A solder-free cap having an oxidation region S2 in the vicinity of the bonding region S1 (hereinafter, simply referred to as “inside the bonding region S1”) was produced. For the sake of simplicity, the names and numbers of the parts shown in each figure will be quoted in the description of the second embodiment.

Specifically, the bonding region S1 is set on the surface of the Au plating layer 4 of the solder-free cap, and the inside of the bonding region S1 is periodically irradiated with a laser beam using YVO4 as a medium to remove the Au plating layer 4. Then, the Ni plating layer 3 was exposed. When the outermost surface of the Ni plating layer 3 was measured using ESCA850 (manufactured by Shimadzu Corporation), a NiO layer having a thickness of 1 nm to 2 nm was formed. The NiO layer functions as the oxidation region S2. The measurement conditions of ESCA850 were X-Ray (Mg) of 8 kV and 30 mA, and ion etching (Ar) of 2 kV and 20 mA and 3.2 nm / min.

Next, the solder layer 5 is formed on the bonding region S1 of the solderless caps of groups 1 to 3 (example of the present invention) by the same melting and fixing method as in Example 1, and the oxidation region S2 is formed inside the bonding region S1. A soldering cap to be provided was produced. The description and illustration of the method for forming the solder layer 5 which is the same as that of the first embodiment will be omitted.

By observing the cross section in the thickness direction of the soldered cap provided with the oxide region S2 inside the joint region S1, it was confirmed that the molten solder deviates from the joint region S1 and spreads inward. As a result, in each case, the wet spreading of the molten solder deviating from the bonding region S1 and inward was prevented by the oxidation region S2. Therefore, wetting and spreading of the molten solder that goes beyond the oxidation region S2 and further inward does not occur on the surface of the Au plating layer 4. Therefore, when producing a soldering cap, it was found that it is preferable to further provide an oxidation region S2 formed in an annular shape with respect to the inside of the bonding region S1 set in an annular shape on the surface of the Au plating layer 4. ..

Further, from such a result, the electronic component 30 housed inside the package by using the soldering cap of the present invention provided with the oxidation region S2 that deviates from the bonding region S1 and prevents the molten solder from spreading inward. It was found that the poor characteristics of the soldering machine can be further suppressed.

1. 1. Cap, 2. Metal plate, 3. Ni plating layer, 4. Au plating layer, 5. Solder layer, 5'. Solder layer, 10. Package, 20. Case, 21. Ceramic substrate, 22. Ceramic frame, 23. Tungsten layer, 24. Ni—Co alloy layer, 25. Au layer, 30. Electronic components, 31. Bump, S1. Joining area, S2. Oxidation region, S3. Wet and spread, L. Length, T.I. thickness

Claims (5)

A cap for airtight sealing used for an electronic component storage package having a Ni plating layer formed on the surface of a metal plate and an Au plating layer formed on the Ni plating layer.
The Au plating layer has a bonding region with other members, and the bonding region has an Au content of 2.0 % by mass to 10.0 % by mass by surface element analysis, and is on the surface of the bonding region. It has a solder layer formed in an annular shape, and the ratio L / T of the solder layer to the thickness T of the metal plate of the wet spread length L in the thickness direction of the metal plate is 30% or less. Sealing cap. The airtight sealing cap according to claim 1 , which has a solder layer of an Au—Sn-based alloy on the surface of the bonding region. The airtight sealing cap according to claim 1 or 2 , which has an oxidation region inside the bonding region. An electronic component storage package in which an airtight sealing cap according to any one of claims 1 to 3 and an electronic component storage member in which electronic components are stored are joined by soldering. The electronic component storage package according to claim 4 , wherein the solder is an Au—Sn-based alloy.

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