JP7476708B2 - Hermetically sealed package, infrared detector, and method for manufacturing hermetically sealed package - Google Patents

Description

The present invention relates to a hermetically sealed package and a method for manufacturing the same.

Some electronic devices, such as semiconductors and sensors, require mounting in a hermetically sealed package. The inside of the hermetically sealed package may be a vacuum or may contain an inert gas.

A method for manufacturing such a hermetically sealed package is disclosed in, for example, Patent Document 1. In Patent Document 1, a ceramic container in which an infrared detection element is installed and a lid are welded in a vacuum chamber, and the inside is made into a vacuum state and hermetically sealed. Specifically, the hermetically sealed package is manufactured by the following procedure. First, a ceramic container and a lid with an infrared-transmitting window material attached are set on heaters arranged above and below in a vacuum chamber, respectively, and the inside of the vacuum chamber is evacuated to create a vacuum state. Next, the brazing material arranged in the ceramic container is melted by heating with the heater. Then, the ceramic container and the lid are pressed together by using a robot mechanism installed in the vacuum chamber, and the heating of the heater is stopped to solidify the brazing material. In this way, an infrared detection element can be mounted in an airtight sealed package whose internal space is kept in a vacuum state.

Patent Document 2 also discloses a method of providing a through hole in the lid of an airtight sealed package and sealing the through hole in a vacuum chamber that is evacuated. This method requires a mechanism to melt the sealing material and supply it to the through hole in the vacuum chamber, but it does not require a mechanism to raise and lower the workpiece (container or lid), making it possible to miniaturize the vacuum chamber equipment.

Patent Document 3 also discloses a method for vacuum sealing a hollow portion formed by a substrate and a lid without sealing the exhaust port. In this technology, an annular joint and a plurality of isolated joints arranged outside the annular joint are provided on the substrate and the lid. Here, in the isolated joint, the pad on the lid side is made larger than the pad on the substrate side. Then, when the thermally fusible material is supplied to the joint, the thickness of the thermally fusible material arranged in the isolated joint is made thicker than the thickness of the thermally fusible material arranged in the annular joint. In this configuration, the structure is placed in a vacuum chamber and the thermally fusible material is melted. Then, at the stage when the thermally fusible material starts to melt, the isolated joint supports the lid, and the annular joints are separated from each other. In this state, a wide gap is left, so that the hollow portion can be smoothly evacuated. Then, as the melting of the thermally fusible material progresses, the thermally fusible material of the isolated joint spreads wet to the pad on the lid side, and the gap between the substrate and the lid becomes narrower. As the melting progresses further, the annular joint is also joined, and the hollow portion can be sealed while being evacuated to a vacuum. In Patent Document 3, airtight sealing can be achieved without providing a robot mechanism in the vacuum chamber as in Patent Document 1, or a mechanism for sealing the exhaust port as in Patent Document 2, thereby reducing the equipment costs for the vacuum chamber.

JP 2003-139616 A Japanese Patent Application Laid-Open No. 11-326037 U.S. Pat. No. 6,566,170

As mentioned above, in Patent Document 1, a mechanism for raising and lowering mechanical parts must be provided inside the vacuum chamber. In addition, in the technology of Patent Document 2, although a raising and lowering mechanism is not necessary, a mechanism for supplying sealing material to the through-hole must be provided. This poses the problem that the vacuum chamber itself is expensive, and the capital investment costs for the manufacturing equipment are high.

In addition, in the method disclosed in Patent Document 3, if there is a difference in the melting time of the heat-fusible material supplied to the multiple isolated pad portions, there is a difference in the time for the height of the heat-fusible material to decrease, and the lid material has a problem of tilting relative to the base material. If the lid material tilts, the thickness and width of the heat-fusible material at the annular joint will become uneven, which may cause holes in the joint or cause weak parts, reducing the reliability of the airtight seal.

The present invention was made in consideration of the above problems, and aims to provide a hermetically sealed package that can be manufactured using inexpensive equipment and provides a highly reliable hermetic seal.

In order to solve the above problems, the hermetically sealed package of the present invention has a base material and a lid material, which are hermetically bonded to each other to form an airtight hollow structure between them. The base material has a device placement area for placing a device, and a closed, band-like first metallization layer arranged to surround the device placement area. The lid material has a closed, band-like second metallization layer arranged at a position corresponding to the first metallization layer, with its upper surface parallel to the upper surface of the first metallization layer. The first metallization layer and the second metallization layer are bonded by a first bonding layer. In addition, a plurality of island-shaped spacers are arranged at a position not overlapping with the first metallization layer, and have a predetermined height higher than the sum of the thicknesses of the first metallization layer and the second metallization layer.

The method for manufacturing a hermetically sealed package of the present invention uses a substrate having a device placement area for placing a device, and a lid material that hermetically seals the device placement area by being bonded to the substrate. The substrate also has a closed, band-like first metallization layer provided to surround the device placement area, and a plurality of spacers at positions that do not overlap with the first metallization layer and have a predetermined height higher than the thickness of the first metallization layer. The lid material has a closed, band-like second metallization layer provided at a position corresponding to the first metallization layer and having a thickness smaller than the difference between the height of the spacer and the thickness of the first metallization layer. Then, the first metallization layer and the second metallization layer are bonded with a first bonding layer while the spacer regulates the distance between the substrate and the lid material.

The advantage of the present invention is that it provides a hermetically sealed package that can be manufactured using inexpensive equipment and provides a highly reliable hermetic seal.

1 is a cross-sectional view showing a hermetically sealed package according to a first embodiment. FIG. 4 is a cross-sectional view showing a hermetically sealed package according to a second embodiment. FIG. 11 is a plan view showing a base material and a lid material used in the hermetically sealed package of the second embodiment. 5A-5C are cross-sectional views illustrating a first part of a method for manufacturing the hermetically sealed package of the second embodiment. 5A-5C are cross-sectional views illustrating a second part of the method for manufacturing the hermetically sealed package of the second embodiment. 11 is a cross-sectional view showing a third part of the method for manufacturing the hermetically sealed package of the second embodiment. FIG. 11 is a cross-sectional view showing a fourth part of the method for manufacturing the hermetically sealed package of the second embodiment. FIG. FIG. 13 is a cross-sectional view showing a hermetically sealed package according to a third embodiment. FIG. 13 is a cross-sectional view showing another state of the hermetically sealed package of the third embodiment. FIG. 13 is a cross-sectional view showing a hermetically sealed package according to a fourth embodiment. FIG. 13 is a cross-sectional view showing another state of the hermetically sealed package of the fourth embodiment.

Below, an embodiment of the present invention will be described in detail with reference to the drawings. However, the embodiment described below has limitations that are technically preferable for implementing the present invention, but does not limit the scope of the invention to the following. Note that similar components in each drawing are given the same numbers, and descriptions may be omitted.

(First embodiment)
1 is a cross-sectional view showing the hermetically sealed package 1 of the present embodiment. In the hermetically sealed package 1, a base material 10 and a lid material 20 are airtightly joined together, and an airtight hollow structure is formed between them.

The substrate 10 has a device placement area 11 for placing a device, and a closed band-shaped first metallization layer 12 arranged to surround the device placement area 11.

The lid material 20 is provided at a position corresponding to the first metallization layer 12 and has a closed band-shaped second metallization layer 21 whose upper surface is parallel to the upper surface of the first metallization layer 12.

The first metallization layer 12 and the second metallization layer 21 are joined by a first joining layer 30.

In addition, a plurality of island-shaped spacers 13 are arranged in positions that do not overlap with the first metallized layer 12 and the second metallized layer 21, so as to maintain a predetermined distance between the substrate 10 and the lid material 20. The predetermined height of the plurality of spacers 13 can be, for example, the same height.

The above-mentioned hermetically sealed package can be manufactured, for example, as follows. First, a first welding material that is the base of the first bonding layer is placed on the first metallization layer 12, a spacer 13 is placed on the substrate 10, and a second welding material that melts at the melting point of the first welding material is placed on the spacer 13. Next, the lid material 20 is laminated on the substrate 10 so that the second metallization layer 21 faces the first metallization layer 12. In this state, the lid material 20 is lifted by the second welding material, so that a gap is formed between the first welding material and the second metallization layer 21. Therefore, if the whole is placed in a vacuum chamber, the device placement area 11 can be easily evacuated. Next, the whole is heated to melt the first welding material and the second welding material, and the lid material 20 sinks toward the substrate 10, the lid material 20 hits the spacer 13, and the second metallization layer 21 comes into contact with the first welding material. At this time, a second welding material of a predetermined thickness may be present between the spacer 13 and the lid material 20. Next, when the entire structure is cooled, the first welding material solidifies to form the first bonding layer 30. In this way, the device placement area 11 surrounded by the first metallization layer 12, the first bonding layer 30, and the second metallization layer 21 can be vacuum-sealed. In the above method, the device placement area 11 can be easily evacuated, and the spacer 13 hits the lid material 20, preventing the lid material 20 from tilting relative to the substrate 10, and the hermetically sealed package can be hermetically sealed.

As described above, according to this embodiment, vacuum sealing can be performed without providing a robot mechanism, sealing device, or other mechanism within the vacuum chamber, and by fixing the lid material parallel to the substrate. This prevents unevenness in the thickness of the first bonding layer, making it less likely for weak parts or defects to occur. As a result, it is possible to provide an airtight sealed package that can be manufactured using inexpensive equipment and provides a highly reliable airtight seal.

Second Embodiment
2 is a cross-sectional view showing the hermetically sealed package 1000 of this embodiment. In the hermetically sealed package 1000, a base material 100 and a lid material 200 are airtightly joined together, and an airtight hollow structure is formed between them.

The substrate 100 has a recess 110 for placing an electronic device, a closed band-like first metallization layer 120 arranged to surround the recess 110, and a plurality of island-like first protrusions 130 arranged in a position that does not overlap the first metallization layer 12. A third metallization layer 140 is provided on the upper surface of the first protrusion 130. The height of the plurality of island-like first protrusions 130 is greater than the sum of the thickness of the first metallization layer 12 and the thickness of the second metallization layer 21. The height of the plurality of first protrusions 130 can be, for example, the same height.

The lid material 200 has a closed band-shaped second metallization layer 210 provided at a position corresponding to the first metallization layer 120, and a plurality of island-shaped fourth metallization layers 220 provided at a position corresponding to the third metallization layer 140.

The first metallization layer 120 and the second metallization layer 210 are joined by a first deposited metal 300, and the third metallization layer 140 and the fourth metallization layer 220 are joined by a second deposited metal 310.

Figure 3 is a plan view showing an example of the substrate 100 and the lid 200 used in the hermetically sealed package 1000. As shown in Figure 3 (a), in this example, the planar shape of the recess 110 is circular, and the first metallization layer 120 is annular surrounding the recess 110. Four first protrusions 130 are provided on the outside of the first metallization layer 120, and a third metallization layer 140 is disposed on the upper surface thereof. As shown in Figure 3 (b), in the lid 200, a ring-shaped second metallization layer 210 is disposed at a position corresponding to the first metallization layer 120, and a fourth metallization layer 220 is disposed at a position corresponding to the third metallization layer 140. Here, the fourth metallization layer 220 has a larger area than the third metallization layer 140.

Next, a method for manufacturing the hermetically sealed package 1000 will be described. First, as shown in FIG. 4, the electronic device 400 is mounted in the recess 110 of the substrate 100, and the electronic device 400 is electrically connected to the wiring of the substrate 100 (not shown).

Next, as shown in FIG. 5, a first deposited metal 300 is supplied to the first metallized layer 120 of the substrate 100, and a second deposited metal 310 is supplied onto the third metallized layer 140.

Next, as shown in FIG. 6, the substrate 100 and the lid material 200 are stacked together and placed in a vacuum chamber (not shown). When the substrate 100 and the lid material 200 are stacked together, the lid material 200 is supported by the second deposited metal 310 supplied to the third metallization layer 140. In this state, there is a gap between the first deposited metal 300 and the second metallization layer 210. When the vacuum chamber is evacuated, the hollow portion 150 composed of the substrate 100 and the lid material 200 inside the first metallization layer 120 can be evacuated through this gap with small exhaust resistance. In addition, outside the first metallization layer 120, exhaust is performed through the gaps between the multiple island-shaped first convex portions 130, so the exhaust resistance is also small. Therefore, the hollow portion 150 can be efficiently evacuated, and the time until the hollow portion 150 reaches a predetermined vacuum level can be shortened.

In addition, during this lamination process, a weight 500 is placed on the lid material 200. Note that if the load of the lid material 200 is higher than the surface tension of the second weld metal 310 when the second weld metal 310 placed on the third metallization layer 140 melts, it is not necessary to place a weight on it.

After the hollow portion 150 is evacuated in a vacuum chamber to create a vacuum state, the substrate 100 is heated to a temperature equal to or higher than the melting point of the first weld metal 300 and the second weld metal 310. When the first weld metal 300 and the second weld metal 310 melt, the first metallization layer 120 and the second metallization layer 210 are joined, and the third metallization layer 140 and the fourth metallization layer 220 are joined, as shown in FIG. 7. At this time, since the area of the fourth metallization layer 220 is larger than the area of the third metallization layer 140, the second weld metal 310 spreads wet on the surface of the fourth metallization layer 220, and the gap between the third metallization layer 140 and the fourth metallization layer 220 becomes extremely small. Then, as shown in FIG. 7, most of the second weld metal 310 solidifies outside the third metallization layer 140. As a result, the distance between the substrate 100 and the lid 200 is determined by the height of the first protrusion 130, the thickness of the third metallization layer 140, and the thickness of the fourth metallization layer 220, and the distance can be precisely controlled. Therefore, the thickness of the first deposited metal 300 that seals the hollow portion 150 is not uneven, and the deposited metal 300 is less likely to have weak parts or defects, so a highly reliable hermetic seal can be achieved.

As described above, according to this embodiment, a highly reliable hermetically sealed package can be manufactured using an inexpensive vacuum chamber that does not include a robot mechanism or the like.
(Example)
Next, a specific configuration and manufacturing method of the hermetically sealed package will be described using an infrared detector in which an infrared detection element is mounted in a hermetically sealed package as an example. First, before describing a specific manufacturing method, the relationship between the infrared detector and the hermetically sealed package will be described. An infrared detector is an element that receives light in the infrared region and converts it into an electrical signal. It has features such as being able to obtain images using infrared rays that do not stimulate human vision, and being able to instantly measure the temperature of an object from a distance without contact. Infrared detectors are divided into two types, thermal type and quantum type, based on the operating principle. Of these, in a thermal type infrared detector, when infrared rays are received, the infrared detection element is heated by heat, and an electrical signal that changes due to the rise in element temperature is detected. The thermal type has a lower sensitivity and response speed than the quantum type, but is characterized by a wide wavelength band and being usable at room temperature. Thermal type infrared detection elements include thermopiles that utilize the thermoelectromotive effect, pyroelectric sensors such as PZT (Lead Zirconate Titanate), thermistors whose electrical resistance changes with temperature changes, and bolometers. Thermal infrared detectors detect light by converting infrared energy into heat and measuring the temperature change, so it is necessary to prevent heat dissipation through the atmosphere. For this reason, it is desirable to store and operate the detector in a sealed vacuum container. It is known that maintaining a vacuum inside reduces heat emission through the air, and increases the sensitivity of the infrared detector element.

Next, we will explain an example of the configuration of an infrared detector using a hermetically sealed package and a manufacturing method. In the following explanation, please refer to Figures 2 and 3 for the structure, and Figures 4-7 for the manufacturing method, and the corresponding symbols will be listed.

The infrared detector (1000) is composed of an infrared detector element (400), a ceramic substrate (100) as a base material having a cavity portion (110), and an infrared-transmitting window (200) as a cover material for closing the cavity portion (110) (Figure 2). The hollow portion (150) formed by the ceramic substrate (100) and the infrared-transmitting window (200) is hermetically sealed without communicating with the outside of the infrared detector (1000) and is kept in a vacuum state. The infrared detector element (400) is mounted in the cavity portion (110) of the ceramic substrate (100) and is connected to the ceramic substrate (100) by wires or the like (not shown). The infrared-transmitting window (200) is made of a material having infrared transmittance, such as germanium, silicon, or sapphire.

More specifically, the edge around the cavity portion (110) of the ceramic substrate (100) and the infrared-transmitting window (200) are hermetically sealed by the solder material (300). A first metallization layer (120) and a second metallization layer (210) are formed between the connected ceramic substrate (100) and the solder material (300), and between the connected infrared-transmitting window (200) and the solder material (300), respectively. The widths of the first metallization layer (120) and the second metallization layer (210) can be, for example, in the range of 0.2 mm to 5 mm.

On the ceramic substrate (100) and the infrared-transmitting window (200), a third metallization layer (140) and a fourth metallization layer (220) are formed in a plurality of islands outside the first metallization layer (120), respectively. The third metallization layer (140) has an independent pad shape. The third metallization layer (140) and the fourth metallization layer (220) are connected by a solder material (310). In this embodiment, both the first deposited metal 300 and the second deposited metal 310 are solder materials.

The third metallization layer (140) is formed on the first convex portion (130). Therefore, there is a step between the surface of the ceramic substrate (100) on which the first metallization layer (120) is formed and the surface on which the third metallization layer (140) is formed, with the third metallization layer (140) being higher. The height of the step can be in the range of 0.1 to 2 mm, for example. In this embodiment, the height of the step is 0.25 mm.

In this embodiment, the ceramic substrate (100) and the infrared transmission window (200) have a rectangular shape when viewed from above, as shown in FIG. 3. The third metallization layer (140) and the fourth metallization layer (220) are located at four corners of the rectangular ceramic substrate (100). However, the third metallization layer (140) and the fourth metallization layer (220) can be located at any position. In other words, the second metallization layer (140) and the fourth metallization layer (220) only need to be located in an island shape at a position that does not overlap with the first metallization layer 120 and the second metallization layer 210. In this embodiment, the third metallization layer (140) is formed outside the first metallization layer (120).

The third metallization layer (140) is preferably circular, for example, with a diameter of 0.2 to 2.0 mm, and the fourth metallization layer (220) is preferably sufficiently larger than the second metallization layer (140). In addition, the shape of the third metallization layer (140) can be changed from a circular shape to a square, hexagon, or other shape.

As the solder material (300, 310), the temperature during soldering must not exceed the heat resistance temperature of the infrared detection element (400), and SnAg-based solder or SnBi-based solder is used according to the heat resistance temperature of the infrared detection element (400). The solder material (300) on the first metallization layer (120) and the solder material (310) on the third metallization layer (140) can be made of different materials. In addition, the first metallization layer (120) and the third metallization layer (140) formed on the ceramic substrate (100) side can be made of a conductive pattern of Mo, Mn, Ti, Ag, etc., plated with Ni, Au, etc. The second metallization layer (210) and the fourth metallization layer (220) formed on the infrared transmission window (200) side can be made of, for example, Cr, Cu, Ni, Ag, Au, etc.

Next, a method for manufacturing the infrared detector of this embodiment will be described. First, as shown in FIG. 4, an infrared detector element (400) is mounted in the cavity portion (110) of the ceramic substrate (100), and the infrared detector element (400) and the ceramic substrate (100) are electrically connected by wire bonding.

Next, as shown in FIG. 5, solder materials (300, 310) are supplied onto the first metallization layer (120) and the third metallization layer (140) formed on the surface of the ceramic substrate (100). The thickness of the solder materials (300, 310) was set to 0.25 mm.

The supply of the solder material (300) onto the first metallization layer (120) of the ceramic substrate (100) (first deposited metal forming process) can be performed, for example, by placing a plate-shaped solder on the first metallization layer (120) and melting it. In this way, it is easy to form a layer of the solder material (300) with good thickness uniformity on the elongated ring-shaped first metallization layer (120). The supply of the solder material (310) onto the third metallization layer (140) (second deposited metal forming process) can be performed, for example, by placing a ball-shaped solder on the third metallization layer (140) and melting it. Since the third metallization layer (140) is island-shaped, it is appropriate to supply the solder material (310) at points. Supplying solder in a ball shape is a common technique, and an inexpensive and high-performance solder supplying device can be used.

In the above description, the solder material is supplied to the ceramic substrate (100) at both of the two joints. However, the solder material (300, 310) may be supplied to the lid material (200) at one or both of the two joints. In addition, the solder material (300, 310) is supplied after the infrared detection element (400) is mounted on the ceramic substrate (100), but the order of the two may be reversed.

Next, as shown in FIG. 6, the ceramic substrate (100) and the infrared-transmitting window (200) are placed in a vacuum chamber (not shown). When the ceramic substrate (100) and the infrared-transmitting window (200) are stacked, the infrared-transmitting window (200) is supported by the solder material (310) supplied to the third metallization layer (140). Therefore, a gap is formed between the solder material (300) and the second metallization layer (210). The hollow portion (150) inside the first metallization layer (120) can be evacuated from this gap. In addition, in this stacking process, a weight is placed on the infrared-transmitting window (200). The weight (500) allows the infrared-transmitting window (200) to sink toward the ceramic substrate (100) when the solder material (300, 310) melts. In addition, if the load on the infrared-transmitting window (200) is higher than the surface tension of the solder material (310) on the third metallization layer (140) when the solder material (310) placed on the third metallization layer (140) melts, it is not necessary to place the weight (500) on it.

Next, as shown in FIG. 6, the hollow portion (150) of the infrared detector (1000) consisting of the ceramic substrate (100) and the infrared transmission window (200) is evacuated in a vacuum chamber to create a vacuum state. In the state shown in FIG. 6, an annular gap is formed between the second metallization layer (210) and the solder material (300), so that the hollow portion (150) can be efficiently evacuated through this gap. After that, the infrared detector (1000) is heated to a temperature above the melting point of the solder material (30, 31), melting the solder material (300, 310) and connecting the ceramic substrate (100) and the infrared transmission window (200) (FIG. 7). At this time, the infrared transmission window (200) sinks, and the solder material (310) spreads wet on the fourth metallization layer (220). As a result, the third metallization layer (140) and the fourth metallization layer (220) are brought into close proximity, and most of the solder material (310) moves to the outside of the third metallization layer (140). Then, the first metallization layer (120) and the second metallization layer (210) are joined by the solder material (300), and the hollow portion (150) is vacuum sealed.

In addition, while the hollow portion (150) is being evacuated, it is advisable to preheat the infrared detector (1000) to a temperature at which the solder material (300, 310) does not melt and at which the heat resistance of the infrared detector element (400) is not an issue. This makes it possible to shorten the time until the hollow portion (150) of the infrared detector (1000) reaches a predetermined degree of vacuum, and to shorten the time for the above-mentioned connection process. This connection process is performed in a vacuum atmosphere, but may be performed by introducing an inert gas into the vacuum chamber.

According to the above manufacturing method, vacuum sealing can be performed without using a robot mechanism for handling the ceramic substrate (100) and the infrared-transmitting window (200), or a mechanism for sealing the through-hole for exhaust. This allows for low capital investment. In addition, since the thickness of the bonding layer between the ceramic substrate (100) and the infrared-transmitting window (200) can be made uniform, a highly reliable hermetically sealed package can be manufactured.

In addition, the solder material (310) present between the third metallization layer (140) and the fourth metallization layer (220) can form a gap between the solder material (300) on the first metallization layer (120) and the second metallization layer (210). The hollow portion (150) between the ceramic substrate (100) and the infrared-transmitting window (200) is evacuated from this gap, so the area for evacuation can be made larger. Therefore, the time required for the hollow portion (150) to be evacuated to a vacuum state can be shortened compared to a method in which evacuation is performed from a fine through-hole.

In addition, when the solder material (310) melts, the third metallization layer (140) and the fourth metallization layer (220) are in a state of almost contact, so the distance between the ceramic substrate (100) and the infrared-transmitting window (200) is constant regardless of location. This makes it possible to connect the infrared-transmitting window (200) to the ceramic substrate (100) without tilting it.

The above explanation uses an example in which the planar shape of the recess 11 is circular and the first metallization layer 12 and the third metallization layer 21 are annular, but the planar shape of the recess can be various shapes, such as a rectangle, a polygon, or an asymmetric shape. In addition, the first metallization layer 21 and the third metallization layer 21 can also be various shapes.

As described above, the configuration of this embodiment makes it possible to obtain a highly reliable hermetically sealed package using an inexpensive vacuum chamber that does not include a robot mechanism, etc.

Third Embodiment
In the first and second embodiments, the configuration in which the convex portion is provided on the substrate has been described, but the convex portion may be provided on the lid material. Fig. 8 is a cross-sectional view showing the configuration of a hermetically sealed package 2000 in which a second convex portion 230 is provided on a lid material 200a. The substrate 100a has a recess 110 for arranging an electronic device, a closed strip-shaped first metallization layer 120 provided so as to surround the recess 110, and a plurality of island-shaped third metallization layers 140a provided at positions not overlapping the first metallization layer 120.

The lid material 200a has a closed band-like second metallization layer 210 provided at a position corresponding to the first metallization layer 120, and a plurality of island-like second protrusions 230 of a predetermined height provided at a position corresponding to the third metallization layer 140a. A fourth metallization layer 220a is provided on the second protrusions 230. The third metallization layer 140a provided on the base material 100a has a larger area than the fourth metallization layer 220a.

As in the second embodiment, the first metallization layer 120 and the second metallization layer 210 are joined by a first deposited metal 300, and the third metallization layer 140a and the fourth metallization layer 220a are joined by a second deposited metal 310.

In the above configuration, before melting the first weld metal 300 and the second weld metal 310, a gap can be created between the first weld metal 300 on the first metallization layer 120 and the second metallization layer 210, as shown in FIG. 9. Then, the hollow portion 150 inside the first metallization layer 120 can be evacuated from this gap, allowing for evacuation with low evacuation resistance. In the example of FIG. 9, the second weld metal 310 is supplied to the fourth metallization layer 220a on the lid material 200 side.

When the exhaust is completed and the first weld metal 300 and the second weld metal 310 are melted, the second weld metal 310 spreads on the third metallization layer 140a. In this way, as shown in FIG. 8, the third metallization layer 140a and the fourth metallization layer 220a are almost in contact with each other, and a structure in which the first metallization layer 120 and the second metallization layer 210 are joined by the first weld metal 300 can be obtained. As a result, the thickness of the first weld metal 300 joining the first metallization layer 120 and the second metallization layer 210 can be made constant. In this way, as in the second embodiment, a highly reliable hermetically sealed package can be obtained using an inexpensive vacuum chamber that does not include a robot mechanism or the like.
(Fourth embodiment)
In the second and third embodiments, the island-shaped protrusions are arranged outside the closed band-shaped first metallization layer, but they may be arranged inside the first metallization layer. Fig. 10 is a cross-sectional view showing a hermetically sealed package 3000 having this configuration. The substrate 100b has a recess 110 for arranging an electronic device, and outside the recess 110, a plurality of island-shaped first protrusions 130b having a predetermined height are formed, and a third metallization layer 140b is formed on the upper surface of the first protrusions 130b. In addition, a closed band-shaped first metallization layer 120b is provided so as to surround the area where the third metallization layer 140b is arranged.

The lid 200b has a fourth metallization layer 220b at a position corresponding to the third metallization layer 140b, and a closed band-shaped second metallization layer 210b at a position corresponding to the first metallization layer 120b. The fourth metallization layer 220b has a larger area than the third metallization layer 140b.

As in the second and third embodiments, the first metallization layer 120b and the second metallization layer 210b are joined by a first deposited metal 300, and the third metallization layer 140b and the fourth metallization layer 220b are joined by a second deposited metal 310.

In the above configuration, before melting the first weld metal 300 and the second weld metal 310, a gap can be created between the first weld metal 300 on the first metallization layer 120b and the second metallization layer 210b, as shown in FIG. 11. Then, the hollow portion 150 inside the first metallization layer 120b can be evacuated from this gap, allowing for evacuation with low evacuation resistance. Then, in the joining of the third metallization layer 140b and the fourth metallization layer 220b, the second weld metal 310 spreads over the fourth metallization layer 220b, narrowing the gap to a distance where the two are almost in contact. As a result, the distance between the base material 100b and the lid material 200b is determined by the height of the first convex portion 130b, which has good processing accuracy, the thickness of the second metallization layer 140b, and the thickness of the fourth metallization layer 220b, and does not depend on the thickness of the first weld metal 300 and the second weld metal 310. As a result, the thickness of the first weld metal 300 that joins the first metallization layer 120b and the second metallization layer 210b can be made constant. In this way, as with the second and third embodiments, a highly reliable hermetically sealed package can be obtained using an inexpensive vacuum chamber that does not include a robot mechanism, etc.

The present invention has been described above using the first to fourth embodiments as exemplary examples. However, the present invention is not limited to the above-mentioned embodiments. In other words, the present invention can be applied in various aspects that can be understood by a person skilled in the art within the scope of the present invention.

A part or all of the above-described embodiments can be described as, but is not limited to, the following supplementary notes.
(Appendix 1)
A substrate having a device placement area for placing a device and a first metallization layer in a closed band shape provided so as to surround the device placement area;
a cover member having a second metallization layer in a closed band shape, the second metallization layer being provided at a position corresponding to the first metallization layer and the upper surface of the second metallization layer being parallel to the upper surface of the first metallization layer;
a first bonding layer that bonds the first metallization layer and the second metallization layer;
a plurality of spacers arranged at positions not overlapping the first metallization layer and the second metallization layer, the spacers having a predetermined height greater than the sum of the thicknesses of the first metallization layer and the second metallization layer;
A hermetically sealed package comprising:
(Appendix 2)
The spacer is
2. The hermetically sealed package of claim 1, wherein the first metallization layer is disposed outside the first metallization layer.
(Appendix 3)
The spacer is
2. The hermetically sealed package of claim 1, wherein the first metallization layer is disposed inside the first metallization layer.
(Appendix 4)
The spacer is
4. The hermetically sealed package of claim 1, further comprising a first protrusion integral with the base material.
(Appendix 5)
The spacer is
a third metallization layer formed on an upper surface of the first protrusion;
a fourth metallization layer formed on the lid at a position corresponding to the third metallization layer;
a second bonding layer bonding the third metallization layer and the fourth metallization layer;
5. The hermetically sealed package of claim 4, comprising:
(Appendix 6)
The hermetically sealed package of claim 5, wherein the third metallization layer and the fourth metallization layer have different areas.
(Appendix 7)
7. The hermetically sealed package according to claim 5 or 6, wherein the second bonding layer is a solder material.
(Appendix 8)
The spacer is
4. The hermetically sealed package of claim 1, further comprising a second protrusion integral with the lid.
(Appendix 9)
The spacer is
a fifth metallization layer formed on an upper surface of the second protrusion;
a sixth metallization layer formed on the substrate at a position corresponding to the fifth metallization layer;
a third bonding layer bonding the fifth metallization layer and the sixth metallization layer;
9. The hermetically sealed package of claim 8, comprising:
(Appendix 10)
10. The hermetically sealed package of claim 9, wherein the fifth metallization layer and the sixth metallization layer have different areas.
(Appendix 11)
11. The hermetically sealed package of claim 9 or 10, wherein the third bonding layer is a solder material.
(Appendix 12)
12. The hermetically sealed package according to any one of claims 1 to 11, wherein a space surrounded by the first metallization layer, the second metallization layer, and the first bonding layer is evacuated to a vacuum.
(Appendix 13)
13. The hermetically sealed package of claim 1, wherein the first bonding layer is a solder material.
(Appendix 14)
The base material is formed using a ceramic substrate.

14. The hermetically sealed package according to any one of claims 1 to 13.
(Appendix 15)
The device placement area includes:
15. The hermetically sealed package according to any one of claims 1 to 14, further comprising a recess for placing the device.
(Appendix 16)
An infrared detection element is mounted in the device arrangement area of the hermetically sealed package according to any one of claims 1 to 15,
The infrared detector, wherein the cover is made of an infrared-transmitting material.
(Appendix 17)
a substrate having a device placement area for placing a device, a first metallization layer in a closed band shape provided so as to surround the device placement area, and a plurality of spacers having a predetermined height higher than a thickness of the first metallization layer at positions not overlapping the first metallization layer;
a lid member having a closed band-like second metallization layer, the second metallization layer being provided at a position corresponding to the first metallization layer and having a thickness smaller than the difference between the height of the spacer and the thickness of the first metallization layer; and bonding the first metallization layer and the second metallization layer with a first bonding layer in a state in which the spacer regulates the gap between the base material and the lid member.
4. A method for producing a hermetically sealed package comprising the steps of:
(Appendix 18)
The spacer is
a first protrusion provided on the base material; and a third metallization layer formed on an upper surface of the first protrusion,
the lid member has a fourth metallization layer formed at a position corresponding to the third metallization layer,
the third metallization layer and the fourth metallization layer are bonded to each other by a second bonding layer while the spacer regulates the distance between the base material and the lid material;
18. The method of claim 17, wherein the hermetically sealed package is
(Appendix 19)
The method for manufacturing a hermetically sealed package described in Appendix 18, characterized in that the third metallization layer and the fourth metallization layer have different areas, and when bonding the second bonding layer, the second bonding layer is caused to wet and spread onto the one of the two having the larger area.
(Appendix 20)
In a state in which the spacer regulates the distance between the base material and the lid material,
20. The method for manufacturing a hermetically sealed package according to claim 18 or 19, characterized in that a first deposited metal forming the first bonding layer and a second deposited metal forming the second bonding layer are melted in a vacuum.
(Appendix 21)
A substrate having a device placement area for placing a device and a first metallization layer in a closed band shape provided so as to surround the device placement area;
a lid material including a closed band-like second metallization layer provided at a position corresponding to the first metallization layer, and a plurality of spacers at positions not overlapping the second metallization layer and having a predetermined height higher than the sum of the thicknesses of the first and second metallization layers, and the first metallization layer and the second metallization layer are bonded together with a first bonding layer while the spacers regulate the gap between the base material and the lid material;
4. A method for producing a hermetically sealed package comprising the steps of:
(Appendix 22)
The spacer is
a second protrusion provided on the lid member; and a fourth metallized layer formed on an upper surface of the second protrusion,
the substrate has a third metallization layer formed at a position corresponding to the fourth metallization layer;
the third metallization layer and the fourth metallization layer are bonded to each other by a second bonding layer while the spacer regulates the distance between the base material and the lid material;
22. The method of claim 21, wherein the hermetically sealed package is
(Appendix 23)
The method for manufacturing a hermetically sealed package described in Appendix 22, characterized in that the third metallization layer and the fourth metallization layer have different areas, and when bonding the second bonding layer, the second bonding layer is caused to wet and spread onto the one of the two having a larger area.
(Appendix 24)
In a state in which the spacer regulates the distance between the base material and the lid material,
24. The method for manufacturing a hermetically sealed package according to claim 22 or 23, characterized in that a first deposited metal forming the first bonding layer and a second deposited metal forming the second bonding layer are melted in a vacuum.

A method for producing a hermetically sealed package as described in appendix 21 or 22.

REFERENCE SIGNS LIST 1, 1000, 2000, 3000 Hermetically sealed package 10, 100 Substrate 11 Device placement area 12, 120 First metallization layer 13 Spacer 20, 200 Lid material 21, 210 Second metallization layer 30 First bonding layer 400 Electronic device 110 Recess 130 First protrusion 140 Third metallization layer 150 Hollow portion 220 Fourth metallization layer 230 Second protrusion 300 First deposited metal 310 Second deposited metal

Claims (10)

A substrate having a device placement area for placing a device and a first metallization layer in a closed band shape provided so as to surround the device placement area;
a cover member having a second metallization layer in a closed band shape, the second metallization layer being provided at a position corresponding to the first metallization layer and the upper surface of the second metallization layer being parallel to the upper surface of the first metallization layer;
a first bonding layer that bonds the first metallization layer and the second metallization layer;
a plurality of spacers arranged at positions not overlapping the first metallization layer and the second metallization layer, the spacers having a predetermined height greater than the sum of the thicknesses of the first metallization layer and the second metallization layer;
having
the spacer includes a first portion formed on the base material, a second portion formed on the lid material, and a second bonding layer bonding the first portion and the second portion together,
a sum of a thickness of the first portion and a thickness of the second portion is greater than a sum of a thickness of the first metallization layer and a thickness of the second metallization layer;
a first molten metal disposed between the first metallization layer and the second metallization layer before bonding the first metallization layer and the second metallization layer serves as the first bonding layer to bond the first metallization layer and the second metallization layer;
a second deposited metal disposed between the first portion and the second portion before the joining serves as the second joining layer to join the first portion and the second portion together;
The sum of the thickness of the first portion, the thickness of the second portion, and the thickness of the second deposited metal is greater than the sum of the thickness of the first metallization layer, the thickness of the second metallization layer, and the thickness of the first molten metal.
A hermetically sealed package characterized by: The spacer is
The first portion includes a first protrusion integral with the base material.
2. The hermetically sealed package of claim 1. The spacer is
the first portion including a third metallization layer formed on an upper surface of the first protrusion;
the second portion including a fourth metallization layer formed at a position of the lid corresponding to the third metallization layer;
the second bonding layer bonding the third metallization layer and the fourth metallization layer;
3. The hermetically sealed package of claim 2, comprising: The hermetically sealed package of claim 3 , wherein the third metallization layer and the fourth metallization layer have different areas. The spacer is
The hermetically sealed package of claim 1 , further comprising the second portion including a second protrusion integral with the lid material. 6. The hermetically sealed package according to claim 1, wherein a space surrounded by the first metallization layer, the second metallization layer, and the first bonding layer is evacuated to a vacuum. The device placement area includes:
The hermetically sealed package according to any one of claims 1 to 6, further comprising a recess for disposing the device therein. An infrared detection element is mounted in the device arrangement area of the hermetically sealed package according to any one of claims 1 to 7,
The infrared detector, wherein the cover is made of an infrared-transmitting material. a substrate having a device placement area for placing a device, a first metallization layer in a closed band shape provided so as to surround the device placement area, and a plurality of spacers having a predetermined height higher than a thickness of the first metallization layer at positions not overlapping the first metallization layer;
a lid member having a closed band-like second metallization layer, the second metallization layer being provided at a position corresponding to the first metallization layer and having a thickness smaller than the difference between the height of the spacer and the thickness of the first metallization layer; and bonding the first metallization layer and the second metallization layer with a first bonding layer while the spacer regulates the gap between the base material and the lid member;
the spacer includes a first portion formed on the base material, a second portion formed on the lid material, and a second deposited metal disposed between the first portion and the second portion;
a sum of a thickness of the first portion and a thickness of the second portion is greater than a sum of a thickness of the first metallization layer and a thickness of the second metallization layer;
before the first metallization layer and the second metallization layer are joined, a sum of a thickness of the first portion, a thickness of the second portion, and a thickness of the second deposited metal is greater than a sum of a thickness of a first molten metal disposed between the first metallization layer and the second metallization layer, a thickness of the first metallization layer, and a thickness of the second metallization layer;
By the joining, the first molten metal serves as the first joining layer to join the first metallization layer and the second metallization layer, and the second deposited metal serves as the second joining layer to join the first portion and the second portion.
4. A method for producing a hermetically sealed package comprising the steps of: The spacer is
the first portion including a first protrusion provided on the base material and a third metallization layer formed on an upper surface of the first protrusion,
the lid member has the second portion including a fourth metallization layer formed at a position corresponding to the third metallization layer,
the third metallization layer and the fourth metallization layer are bonded to each other by the second bonding layer while the spacer regulates the distance between the base material and the lid material.
10. The method of claim 9, wherein the hermetically sealed package is made of a material selected from the group consisting of fluororesin, fluororubber, fluororesin, fluororubber.

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