JP2020150004A - Package and method for manufacturing package - Google Patents

Abstract

To provide a package that can prevent the generation of cracks in a joining part where substrates are joined and sealed, is manufactured at a low cost, and is excellent in productivity and device characteristics.SOLUTION: A package comprises: a first substrate 2; a device 4 that is provided on the first substrate 2; a second substrate 3 that is joined onto the first substrate 2, and has convex bodies 31 in a frame shape in plan view and a concave cavity area 32; and joint bodies 50 that each have a second metal junction film 6 provided at the tip of the convex body 31 in a frame shape in plan view, and a first metal junction film provided on the first substrate 2 at a position corresponding to the convex body 31 in a frame shape in plan view, which are joined by metal diffusion. The first metal junction film and the second metal junction film 6 have a concavo-convex shape formed of concave parts and convex parts alternately arranged along a circumferential direction, and the concave parts and convex parts of the first metal junction film and the concave parts 6A and convex parts 6B of the second metal junction film 6 are overlapped and joined.SELECTED DRAWING: Figure 1

Description

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

For example, a package used in a semiconductor device such as an infrared sensor is generally provided with a first substrate, a sensor element, and a second substrate. The sensor element is provided on the upper surface of the first substrate and performs various detections. Further, the second substrate is joined to the upper surface of the first substrate while covering the sensor element. Further, the sealing space secured above the sensor element, which is covered with the first substrate and the second substrate, is a decompression space (cavity).

In the above packages, especially infrared sensors, since it is necessary to perform thermal isolation from the external system in order to stabilize and improve the sensor characteristics, a configuration in which the inside of the cavity is vacuum-sealed is generally adopted. Will be done. Conventionally, in a package for vacuum-sealing the inside of a cavity, for example, gold (Au): 80% and tin (Sn) are used as a metal bonding layer (solder) for bonding the first substrate and the second substrate. ): A material containing 20% (Au—Sn eutectic alloy) or the like is used, but when such a metal bonding layer is used, it is necessary to bond the substrates at a high temperature. However, when the first substrate and the second substrate are joined at a high temperature, cracks may occur in the joined portion due to the difference in the coefficient of thermal expansion. For the purpose of solving such a problem, for example, a technique for suppressing the occurrence of cracks in the joint by forming a stress relaxation buffer layer in the joint has been proposed (see, for example, Patent Document 1). ..

Special Table 2017-527113

When a configuration in which a stress relaxation buffer layer is provided at a joint portion is adopted as in the technique described in Patent Document 1, the coefficient of thermal expansion of this stress relaxation buffer layer is larger than the coefficient of thermal expansion of the surface portion of the substrate. Moreover, it is required to have a value smaller than the coefficient of thermal expansion of the material used for the metal bonding layer. On the other hand, in addition to the metal bonding layer as described above, the thickness of each film formed on the substrate varies. Therefore, the process control when forming each of these films is controlled by the stress relaxation buffer layer. When implemented in combination with the process control of the above, there is a problem that the process time becomes long and the manufacturing cost increases. Further, there is a problem that film formation of a plurality of films on a substrate and process control in consideration of the coefficient of thermal expansion of the stress relaxation buffer layer require a large amount of labor from the viewpoint of ensuring process quality. ..

The present invention has been made in view of the above problems, and has a simple configuration, can suppress cracks and the like at the joints where the substrates are joined and sealed, and the cost is low, and the productivity and the device are high. The purpose is to provide a package with excellent characteristics.
Further, the present invention can alleviate the stress generated at the joint when the substrates are joined and sealed without requiring complicated process control, and can suppress the occurrence of cracks and the like at the joint. It is an object of the present invention to provide a package manufacturing method capable of manufacturing a package having excellent element characteristics with high productivity.

In order to solve the above problems, the package of the present invention is joined to a first substrate, an element provided on the upper surface side of the first substrate, and the upper surface side of the first substrate with the element covered. On the lower surface side arranged on the first substrate side, a planar view frame-shaped convex body joined to the first substrate and a convex body in a plan view are formed so as to be surrounded by the convex body and sealed on the element. A second substrate having a concave cavity region for securing a still space, a second metal bonding film provided at the tip of the convex body formed on the second substrate in a planar view frame shape, and the first metal bonding film. 2. A joint body formed by metal diffusion bonding of a first metal bonding film provided on the upper surface of the first substrate in a plan view frame shape at a position corresponding to the convex body formed on the two substrates is provided. The first metal bonding film and the second metal bonding film have a concave-convex shape in which at least a part in the circumferential direction is composed of concave portions and convex portions alternately arranged along the circumferential direction in a plan view. The concave and convex portions of the first metal bonding film and the concave and convex portions of the second metal bonding film are overlapped and bonded.

According to the present invention, as described above, the frame-shaped first metal bonding film and the second metal bonding film have a concavo-convex shape composed of concave portions and convex portions alternately arranged along the circumferential direction. , The first metal bonding film and the second metal bonding film are bonded by overlapping the concave portions and the convex portions of each, so that the stress at the joint is dispersed in the horizontal and vertical directions, and the stress is effective. Therefore, even when the first substrate and the second substrate are joined at a high temperature, it is possible to prevent cracks and the like from occurring in the joined portion.
Further, since the bonded body composed of the first metal bonding membrane and the second metal bonding membrane is provided, when the first substrate and the second substrate are bonded, high sealing airtightness can be obtained by metal diffusion bonding. Be done. Furthermore, since unevenness and the like due to the processing accuracy of the first substrate and the second substrate are absorbed, in addition to the improvement of the sealing airtightness, the internal electrical characteristics are also improved, and excellent element characteristics are obtained. can get.
Therefore, it is possible to realize a package having a simple configuration, low cost, and excellent productivity and element characteristics.

Further, in the above configuration, the package of the present invention may have a configuration in which the uneven shapes of the first metal bonding film and the second metal bonding film are periodically arranged in the circumferential direction. it can.

According to the present invention, the uneven shape of the first metal bonding film and the second metal bonding film is a shape that is periodically arranged in the circumferential direction, so that the stress at the joint portion as described above is horizontally and. By dispersing in the vertical direction, the action of relieving stress can be stably obtained.

Further, in the package of the present invention, in the above configuration, at least a part in the circumferential direction is along the circumferential direction so that the convex body corresponds to the uneven shape of the second metal bonding film. A configuration having a concavo-convex shape consisting of concave and convex portions arranged alternately may be adopted.

According to the present invention, similarly to the second metal bonding film, the convex body has a concavo-convex shape consisting of concave portions and convex portions alternately arranged along the circumferential direction, whereby the first metal bonding film and the second metal bonding film and the second In addition to the action obtained by the uneven shape of the metal bonding film, the stress at the joint portion is more effectively dispersed, and the action of relieving the stress is remarkably obtained.

In addition, the package of the present invention preferably adopts a configuration in which the first substrate and the second substrate are made of a silicon substrate in the above configuration.

According to the present invention, since the first substrate and the second substrate are made of a silicon substrate having excellent workability, the internal stress due to bonding is reduced and the processing accuracy due to the etching process is improved, so that the element characteristics are further improved. It will be excellent.

Further, in the above configuration, the package of the present invention can adopt a configuration as a so-called infrared sensor in which the element is an infrared detection element and the second substrate is capable of transmitting infrared rays. ..

According to the present invention, by adopting a configuration having the above-mentioned package structure and an infrared detection element as an element, cracks and the like are suppressed at the joint portion, the cost is low, and the productivity and the element are reduced. An infrared sensor can be realized as a package with excellent characteristics.

The package manufacturing method of the present invention includes at least a step (1) of obtaining a first substrate by forming a concave device region for accommodating an element by etching the surface of the substrate material and etching the surface of the substrate material. By doing so, a convex body having a plan view frame shape and a concave cavity region formed so as to be surrounded by the convex body in a plan view and for securing a sealing space on the element are formed. In the step (2) of obtaining the second substrate, at least a part of the convex body formed on the second substrate in the circumferential direction is in the shape of a plan view along the circumferential direction. The step (3) of forming a second metal bonding film having a concavo-convex shape composed of concave and convex portions arranged alternately, and the first substrate and the second substrate are overlapped on the first substrate. Concavo-convex shape consisting of concave portions and convex portions alternately arranged along the circumferential direction in a plan view, at least a part in the circumferential direction, in a plan view frame shape at a position corresponding to the convex body when combined. The step (4) of forming the first metal bonding film having the above, the step (5) of arranging the element in the device region formed on the first substrate, and the first substrate and the second substrate. By superimposing the first substrate and the second substrate so that the element is arranged between the two, and pressurizing the first metal bonding film and the second metal bonding film with each other to perform metal diffusion bonding. , The step (6) of superimposing and joining the concave and convex portions of the first metal bonding film and the concave and convex portions of the second metal bonding film, and joining the first substrate and the second substrate. It is characterized by having.

According to the present invention, as described above, in the step (3), a second metal bonding film having an uneven shape is formed at the tip of the frame-shaped convex body on the second substrate, and in the step (4). After forming a first metal bonding film having a concavo-convex shape on the first substrate at a position corresponding to the convex body of the second substrate, in step (6), the first metal bonding film and the second metal bonding film are bonded. By superimposing the unevenness of each of the films and metal diffusion bonding, a bonding allowance between the metal bonding films is formed. By forming such a joint allowance, the stress at the joint portion is dispersed in the horizontal direction and the vertical direction, and the stress is effectively relieved. As a result, when the first substrate and the second substrate are joined at a high temperature, it is not necessary to control the coefficient of thermal expansion of each film formed on the substrate, and complicated process control is not required, and a new process is required. It is possible to prevent cracks and the like from occurring at the joint without adding the above.
Further, the above-mentioned steps (3) and (4) are provided, and the above-mentioned first metal bonding film and the second metal bonding film are formed at corresponding positions, and then the first step (6) is performed. By metal diffusion bonding the 1 metal bonding film and the 2nd metal bonding film and bonding the 1st substrate and the 2nd substrate, a package having high sealing airtightness can be obtained. Further, since unevenness and the like caused by the processing accuracy of the first substrate and the second substrate are absorbed, in addition to the improvement of the sealing airtightness, the internal electrical characteristics are also improved, so that the package having excellent characteristics can be obtained. It becomes possible to manufacture.
Therefore, it is possible to produce a package having excellent element characteristics at low cost with high productivity without requiring complicated process control.

Further, in the method for manufacturing a package of the present invention, in the above configuration, the step (3) and the step (4) have the uneven shape provided on the first metal bonding film or the second metal bonding film. It can be a method of forming by arranging periodically in the circumferential direction.

According to the present invention, by periodically forming the uneven shape provided on the first metal bonding film and the second metal bonding film in the circumferential direction, the first substrate and the second substrate are formed in the above step (6). When joining, the stress at the joint is dispersed in the horizontal and vertical directions, and the stress is relaxed in a stable manner.

Further, in the method for manufacturing a package of the present invention, in the above configuration, the step (2) is further arranged, and at least a part of the convex body in the circumferential direction is alternately arranged along the circumferential direction. It is formed so as to have a concave-convex shape composed of concave portions and convex portions, and in the step (3), at least a part of the second metal bonding film in the circumferential direction is formed so as to cover the tip of the convex body. The method may be a method of forming the concave-convex shape composed of concave portions and convex portions alternately arranged along the circumferential direction.

According to the present invention, the convex body is formed into a concavo-convex shape consisting of concave portions and convex portions alternately arranged along the circumferential direction, similarly to the second metal bonding film, thereby forming the first metal bonding film and the first In addition to the action obtained by the uneven shape of the two metal bonding film, the stress at the bonding portion when the first substrate and the second substrate are bonded in the above step (6) is dispersed in the horizontal direction and the vertical direction. The effect of relieving stress is remarkably obtained.

Further, in the package manufacturing method of the present invention, in the above configuration, it is more preferable that the steps (1) and (2) are steps in which a silicon substrate is used as the substrate material.

According to the present invention, by using a silicon substrate having excellent workability for the first substrate and the second substrate, the internal stress at the time of joining the first substrate and the second substrate in the subsequent step (6). And the processing accuracy by the etching process is improved, so that it is possible to manufacture a package having more excellent element characteristics.

Further, in the package manufacturing method of the present invention, in the above configuration, the step (5) employs a method in which an infrared detection element is arranged as the element in the device region formed on the first substrate. May be good.

According to the present invention, since the method has a package structure obtained by each of the above steps and an infrared detection element is arranged in the device region as an element, cracks and the like are suppressed at the joint portion, and the cost is low. It becomes possible to manufacture an infrared sensor as a package having excellent productivity and element characteristics.

According to the package of the present invention, by providing the above configuration, the stress at the joint portion is dispersed in the horizontal direction and the vertical direction and the stress is effectively relieved, so that the first substrate and the second substrate are subjected to high temperature. Even in the case of joining with, it is possible to prevent cracks and the like from occurring at the joined portion. Therefore, it is possible to realize a package having a simple configuration, low cost, and excellent productivity and element characteristics.

Further, according to the package manufacturing method of the present invention, by adopting the above method, the stress at the joint is dispersed in the horizontal direction and the vertical direction, and the stress is effectively relieved, so that the stress is formed on the substrate. It is not necessary to control the coefficient of thermal expansion of each film, complicated process control is not required, and cracks and the like can be prevented from occurring at the joint without adding a new process. Therefore, it is possible to produce a package having excellent element characteristics at low cost with high productivity without requiring complicated process control.

It is a top view schematically explaining the package which is an embodiment of this invention. It is a figure which schematically explains the package which is an embodiment of this invention, and is the cross-sectional view of I-I shown in FIG. It is a figure schematically explaining the package which is an embodiment of this invention, FIG. 3A is a plan view which shows the 2nd metal bonding film, and FIG. 3B is a plan surface which shows the 1st metal bonding film. It is a figure. It is a figure schematically explaining the package which is an embodiment of this invention, and the 2nd metal bonding film shown in FIG. 3A and the 1st metal bonding film shown in FIG. 3B are superposed and bonded. It is the schematic which shows the shape of the bonding allowance in which each bonding film overlaps in the bonded portion. It is a figure schematically explaining the manufacturing method of the package which is an embodiment of this invention, and FIGS. 5A and 5B are the steps of obtaining a 2nd substrate by wet-etching a substrate in step (2). 5 (c) is a process diagram showing a step of forming a second metal bonding film on the convex body of the second substrate in the process (3). FIG. 6A is a diagram schematically illustrating a method for manufacturing a package according to an embodiment of the present invention, in which FIG. 6A shows a step of forming a first metal bonding film on the surface of a first substrate in step (4), and , A process diagram showing a step of arranging an element in a device region in step (5), FIG. 6 (b) shows a step of obtaining a package by joining a first substrate and a second substrate in step (6). FIG. 6 (c) is a process diagram showing a step of dicing a wafer to expose electrodes and forming chips.

Hereinafter, embodiments of the package and the method for manufacturing the package of the present invention will be mentioned, and the configuration thereof will be described in detail with reference to FIGS. 1 to 6 as appropriate. In addition, in each drawing used in the following description, in order to make it easy to understand the features of the package of the present invention, the featured portions may be enlarged for convenience, and the dimensional ratios and the like of each component are actual. May be different. Further, the materials, dimensions, etc. exemplified in the following description are examples, and the present invention is not limited thereto, and the present invention can be appropriately modified without changing the gist thereof.

[Package configuration]
The structure of the package of this embodiment will be described below.
FIG. 1 is a plan view schematically explaining the package 1 of the present embodiment, and FIG. 2 is a sectional view taken along the line II of the package 1 shown in FIG. 3 (a) is a plan view showing the second metal bonding film 6, FIG. 3 (b) is a plan view showing the first metal bonding film 5, and FIG. 4 is a view showing FIG. 3 (a). It is a figure which shows the shape of the bonding allowance K in which the 2 metal bonding film 6 and the 1st metal bonding film 5 shown in FIG. 3B are overlapped and bonded, and the bonding films overlap each other.

As shown in FIGS. 1 and 2, the package 1 of the present embodiment includes a first substrate 2 (base substrate), an element 4, and a second substrate 3 (lid substrate). The package 1 of the present embodiment is provided with the element 4 inside to form various sensor devices, semiconductor devices, and the like.

More specifically, the package 1 of the present embodiment covers the first substrate 2, the element 4 provided on the upper surface 2a side of the first substrate 2, and the element 4 on the upper surface 2a side of the first substrate 2. On the lower surface 3a side which is joined and arranged on the first substrate 2 side, it is formed so as to be surrounded by a plan view frame-shaped convex body 31 joined to the first board 2 and the convex body 31 in a plan view. , A second substrate 3 having a concave cavity region 32 for securing a sealing space (decompression space / cavity) C on the element 4 is provided. As shown in FIG. 1, the package 1 of the present embodiment is provided with electrodes 8a and 8b for outputting a detection signal.

Further, the package 1 of the present embodiment has a second metal bonding film 6 provided in a plan view frame shape at the tip of a convex body 31 formed on the second substrate 3, and a convex shape formed on the second substrate 3. At a position corresponding to the body 31, the upper surface 2a of the first substrate 2 is provided with a bonded body 50 formed by metal diffusion bonding with a first metal bonding film 5 provided in a plan view frame shape.

Then, in the package 1 of the present embodiment, at least a part of the first metal bonding film 5 and the second metal bonding film 6 constituting the bonded body 50 in the circumferential direction (length direction) of the plan view frame is peripheral. It has a concave-convex shape consisting of concave portions 5A, 6A and convex portions 5B, 6B arranged alternately along the direction, and has concave portions 5A and convex portions 5B of the first metal bonding film 5 and concave portions 6A of the second metal bonding film 6. And the convex portion 6B are overlapped and joined. More specifically, the concave portion 5A and the convex portion 5B of the first metal bonding film 5 and the concave portion 6A and the convex portion 6B of the second metal bonding film 6 are superposed so as to be alternately combined, so that the plan view can be seen. They are joined by a C-shaped joining allowance K (see also FIGS. 3A, 3B and 4).
In the example shown in FIG. 1, the first metal bonding film 5 and the second metal bonding film 6 constituting the bonded body 50 are configured such that the above-mentioned uneven shape is provided over the entire circumference in the circumferential direction. , Concavities and convexities are provided so as to have a symmetrical shape in both width directions of each bonding film.

Although not shown, internal wiring for electrically connecting the element 4 and the electrodes 8a and 8b is provided inside the package 1.
Hereinafter, the configuration of the package 1 of the present embodiment will be described.

The first substrate 2 is a base substrate of the package 1, and is made of, for example, a silicon substrate. Further, in the example shown in FIG. 1, the first substrate 2 is formed in a rectangular shape in a plan view. Further, a device region 22 for arranging the element 4 described later is formed in a concave shape on the upper surface 2a of the first substrate 2, and in the illustrated example, the device region 22 is provided substantially in the center in a plan view. There is.

The first substrate 2 can be obtained by forming a device region 22 by wet-etching a silicon substrate. The device region 22 is, for example, a region formed in a rectangular shape in a plan view.
Further, the plan view shape of the first substrate 2 is not limited to the substantially rectangular shape as shown in the illustrated example, and various shapes can be adopted according to the plan view shape of the package 1.
Further, in the present embodiment, the upper surface 2a and the lower surface 2b of the first substrate 2 are configured to be substantially flat except for the portion of the device region 22.

As described above, the element 4 is provided so as to be accommodated in the concave device region 22 formed on the upper surface 2a side of the first substrate 2. Further, the element 4 outputs the detection signal to the outside via the electrodes 8a and 8b.

The element 4 may have, for example, a portion composed of a constituent material of the first substrate 2 which is a base substrate, or may have a portion composed of a material supplied from the outside, and may have a portion composed of a material supplied from the outside. It may have a portion formed by mixing the constituent material of 2 and the material supplied from the outside. Examples of the element 4 in the present embodiment include a sensor element, an electronic element, an integrated circuit, and the like. Further, examples of the sensor element include an infrared sensor, an acceleration sensor, an angular velocity sensor, and the like.

Further, although not shown in FIGS. 1 and 2, in the package 1 of the present embodiment, an insulating layer is provided around the device region 22 on the first substrate 2 and around the electrodes 8a and 8b. It may be provided. Specifically, the insulating layer (not shown) can be provided in a region on the upper surface 2a side of the first substrate 2 outside the element 4 so as to surround the element 4 in a plan view. This insulating layer is made of a material having an insulating property, and is formed of, for example, a silicon oxide film such as silicon dioxide (SiO ₂ ) or a silicon nitride film (SiN _x ).

The second substrate 3 is a lid substrate (lid) of the package 1, and is made of, for example, a silicon substrate like the first substrate 2. Further, the second substrate 3 in the illustrated example is formed in a rectangular shape in a plan view like the first substrate 2. Further, the second substrate 3 has a frame-shaped convex body 31 in the vicinity of the edge portion in a plan view, and is roughly formed in a lid shape. Further, the region inside the convex body 31 in the second substrate 3 in a plan view is a convex provided on the upper surface 2a of the first substrate 2 and the lower surface 3a side of the second substrate 3, as will be described in detail later. When the body 31 is combined and joined, a sealing space C is formed by the cavity region 32.
The cavity region 32 in the illustrated example has a rectangular shape in a plan view.
Further, the convex body 31 of the illustrated example is formed so that its side portion is inclined according to the processing conditions by wet etching, which will be described in detail later.

The second substrate 3 is superposed so as to be substantially parallel to the first substrate 2.
Further, the plan view shape of the second substrate 3 is not limited to the substantially rectangular shape as shown in the illustrated example as in the case of the first substrate 2, and the first substrate 2 is matched with the plan view shape of the package 1. It can be a shape corresponding to.
Further, the second substrate 3 is configured to be capable of transmitting infrared rays when the element 4 is an infrared ray detecting element.

The second substrate 3 has at least a part of the convex body 31 in the circumferential direction so as to correspond to the uneven shape provided on the second metal bonding film 6 which will be described in detail later. It is also possible to adopt a configuration having an uneven shape.

Further, in the package 1 of the present embodiment, it is preferable that the first substrate 2 and the second substrate 3 are made of a silicon substrate. As described above, since the first substrate 2 and the second substrate 3 are made of a silicon substrate having excellent workability, the internal stress due to bonding is reduced and the processing accuracy due to the etching process is improved, so that the element characteristics are further improved. It will be excellent.

As described above, the bonded body 50 is arranged between the upper surface 2a of the first substrate 2 and the convex body 31 of the second substrate 3, and joins the first substrate 2 and the second substrate 3. .. As shown in FIG. 2, the bonded body 50 is a second metal bonding film 6 provided at the tip of a convex body 31 formed on the second substrate 3 and a second surface 2a of the first substrate 2. It is composed of a first metal bonding film 5 provided at a position corresponding to a convex body 31 formed on the substrate 3, and a metal diffusion bonding is formed between them. Further, as shown in FIG. 1, the joint body 50 is formed in a substantially frame shape in a plan view.

The bonded body 50 provided in the package 1 forms a sealing space C surrounded by the first substrate 2, the second substrate 3, and the bonded body 50 by joining the first substrate 2 and the second substrate 3. To do.
Further, the bonded body 50 includes a convex body 31 formed on the second substrate 3 and a portion where the first metal bonding film 5 is formed on the upper surface 2a of the first substrate 2, and the first substrate 2 and the second substrate 3 are formed. It constitutes a joint for joining with and.

More specifically, the bonded body 50 is composed of a first base layer 51 arranged on the upper surface 2a of the first substrate 2 and a first joint layer 52 laminated on the first base layer 51. A second base layer 61 composed of a metal bonding film 5, a second base layer 61 arranged at the tip of a convex body 31 of the second substrate 3, and a second base layer 62 laminated on the second base layer 61. It is composed of a metal bonding film 6.
The first metal bonding film 5 and the second metal bonding film 6 shown in FIG. 2 are formed in a rectangular shape and a frame shape in a plan view.

The first base layer 51 and the second base layer 61 are joined to the upper surface 2a of the first substrate 2 or the tip of the convex body 31 of the second substrate 3, respectively. By providing each of the base layers as described above, the first bonding layer 52 is firmly bonded to the first substrate 2, and the second bonding layer 62 is firmly bonded to the convex body 31 of the second substrate 3. Be joined.

The first base layer 51 and the second base layer 61 are formed in a thin film shape by a conductive metal material on the upper surface 2a of the first substrate 2 or at the tip of the convex body 31 of the second substrate 3, respectively. Has been done.
The material of the first base layer 51 and the second base layer 61 is not particularly limited, but is preferably a thin film made of, for example, tantalum (Ta) or titanium nitride (TiN).
Further, the first base layer 51 provided on the first substrate 2 side is connected to, for example, a ground (not shown). This ground can be provided, for example, on the lower surface 2b side of the first substrate 2, but may be provided on the upper surface 2a side of the first substrate 2.

As described above, the first bonding layer 52 and the second bonding layer 62 are laminated on the first base layer 51 or the second base layer 61, respectively.
The material of the first joint layer 52 and the second joint layer 62 is not particularly limited, but for example, when tantalum is used as the material of the first base layer 51 and the second base layer 61, the first joint layer 52 And gold (Au) is used as the material of the second bonding layer 62. When titanium nitride is used as the material for the first base layer 51 and the second base layer 61, aluminum (Al) is used as the material for the first joint layer 52 and the second joint layer 62.

Then, in the present embodiment, the first bonding layer 52 and the second bonding layer 62 are configured to be bonded to each other with the same material. That is, the first bonding layer 52 and the second bonding layer 62 are both configured to contain the same material, that is, either gold (Au) or aluminum (Al).

When the joint 50 is made of the above materials, the thickness of each layer is not particularly limited. On the other hand, when the first base layer 51 and the second base layer 61 are made of tantalum and the first joint layer 52 and the second joint layer 62 are made of gold in consideration of electrical characteristics, strength at the time of joining, and the like. For example, {1st bonding layer 52 (or 2nd bonding layer 62): 0.5 nm to 2 μm / 1st underlying layer 51 (or 2nd underlying layer 61): 0.05 to 0.2 μm} It is preferable to do so.
Similarly, when the first base layer 51 and the second base layer 61 are made of titanium nitride and the first joint layer 52 and the second joint layer 62 are made of aluminum, for example, {1st joint layer 52 ( Alternatively, the range is preferably in the range of 2nd bonding layer 62): 1 to 3 μm / first base layer 51 (or second base layer 61): 0.05 to 0.5 μm}.

In the present embodiment, the bonded body 50 is composed of the above-mentioned layer structure, and details will be described later. However, when the first substrate 2 and the second substrate 3 are superposed and pressurized, the first substrate 2 and the second substrate 3 are superposed and pressurized. Metal diffusion bonding is developed between the first base layer 51 and the first bonding layer 52 and the second base layer 61 and the second bonding layer 62. As a result, the bonded body 50 has a strong bonding structure, and the first substrate 2 and the second substrate 3 can be firmly bonded while improving the sealing property in the sealing space C.

Further, in the present embodiment, the bonding body 50 is not limited to being composed of the above materials and being metal diffusion bonded. For example, each layer of the bonded body 50 may be composed of gold (Au) or tin (Sn), and an Au—Sn eutectic bonded structure may be adopted. In this case, for example, the first base layer 51 and the second base layer 61, and the first joint layer 52 and the second joint layer 62 are formed from Au—Sn eutectic alloy, respectively, and heated and melted to the eutectic temperature. By doing so, the first base layer 51 and the first bonding layer 52 and the second base layer 61 and the second bonding layer 62 are eutectic bonded. As a result, the first substrate 2 and the second substrate 3 can be joined.

Then, in the bonded body 50 provided in the package 1 of the present embodiment, as shown in FIGS. 3A and 3B, the first metal bonding film 5 and the second metal bonding film 6 have a plan view frame shape. At least a part in the circumferential direction (longitudinal direction) has a concavo-convex shape provided so as to be constricted, consisting of recesses 5A and 6A and convex portions 5B and 6B alternately arranged along the circumferential direction. .. Then, in the example shown in FIG. 4, the first metal bonding film 5 and the second metal bonding film 6 are the concave portion 5A and the convex portion 6B of the first metal bonding film 5 and the concave portion 6A and the convex portion of the second metal bonding film 6. By superimposing the portions 6B so as to be alternately combined, they are joined by a joining allowance K having a substantially C shape (substantially U shape) in a plan view.

According to the package 1 of the present embodiment, the first metal bonding film 5 and the second metal bonding film 6 have the above-mentioned uneven shape, so that the bonding allowance K is formed in a substantially C shape. When the metal bonding film 5 and the second metal bonding film 6 are superposed and bonded at a high temperature, the stress generated in the bonded portion is dispersed in the horizontal direction and the vertical direction. As a result, the stress in and around the joint is effectively relaxed, so that it is possible to prevent cracks and the like from occurring.

The depth (constriction depth) F1 of the recess 5A of the first metal bonding film 5 and the depth (constriction depth) F2 of the recess 6A of the second metal bonding film 6 are not particularly limited, but for example, the first. It is preferable that the dimensions are about 1/4 to 1/3 with respect to the total width H1 of the metal bonding film 5 and the total width H2 of the second metal bonding film 6. For example, when the total widths H1 and H2 of the first metal bonding film 5 and the second metal bonding film 6 are 100 μm, the depths F1 and F2 of the respective recesses 5A and 6A are preferably in the range of 25 to 30 μm. ..
Further, the length L1 of the recess 5A of the first metal bonding film 5 and the length L2 of the recess 6A of the second metal bonding film 6 in the circumferential direction are also not particularly limited, but for example, the recesses 5A and 6A described above. The dimensions can be in the range from the same level as the depths F1 and F2 to the same level as the total widths H1 and H2 of the first metal bonding film 5 and the second metal bonding film 6. For example, when the total widths H1 and H2 of the first metal bonding film 5 and the second metal bonding film 6 are 100 μm, the lengths L1 and L2 of the respective recesses 5A and 6A are preferably in the range of 25 to 100 μm. ..
By setting the total widths H1 and H2 of the first metal bonding film 5 and the second metal bonding film 6, the respective recesses 5A and 6A, and the respective lengths L1 and L2 within the above ranges, the joint portion as described above The stress generated in the above is dispersed in the horizontal direction and the vertical direction, so that the stress is relieved more effectively.

Further, the size of the bonding allowance K between the first metal bonding film 5 and the second metal bonding film 6 is not particularly limited, but at each position where the first metal bonding film 5 and the second metal bonding film 6 are superposed in a substantially C shape, the superposition size is about 30 μm. It is preferable that it is secured. In this case, for example, if the alignment accuracy when the first substrate 2 and the second substrate 3 are overlapped and positioned is ± 10 μm, the minimum overlap dimension at each position of the bonding allowance K is about 20 μm.
By setting the dimension of the bonding allowance K between the first metal bonding film 5 and the second metal bonding film 6 as described above, the stress generated at the bonding portion as described above is dispersed in the horizontal direction and the vertical direction. By doing so, the action of relieving stress can be obtained more stably.

As will be described in detail in the description of the manufacturing method described later, providing the uneven shape as described above on the first metal bonding film 5 and the second metal bonding film 6 means that the first metal bonding film 5 or the second metal bonding film 5 or the second metal bonding film 5 is provided. It can be carried out at the same time in each step of forming the film 6. Therefore, since it is not necessary to provide a new process, the package 1 having excellent productivity and element characteristics can be obtained without increasing the manufacturing cost.

Further, the first metal bonding film 5 and the second metal bonding film 6 may be configured such that the above-mentioned uneven shape is periodically arranged in the circumferential direction. That is, as shown in the examples shown in FIGS. 3A and 3B, the concave portion 5A and the convex portion 5B of the first metal bonding film 5 and the concave portion 6A and the convex portion 6B of the second metal bonding film 6 are formed. Each may be arranged periodically. Also in this case, the above-mentioned action of dispersing the stress at the joint in the horizontal direction and the vertical direction to relieve the stress can be obtained more stably.
Further, the uneven shapes of the first metal bonding film 5 and the second metal bonding film 6 may be arranged aperiodically in the circumferential direction in which the frame shape is formed.

Electrodes 8a and 8b and internal wiring (not shown) are provided on the upper surface 2a of the first substrate 2.
The electrodes 8a and 8b are electrically connected to the element 4 via internal wiring or the like (not shown), and output a detection signal or the like by the element 4 to the outside. The electrodes 8a and 8b are provided on the upper surface 2a of the first substrate 2 along the opposite edges, and in the illustrated example, the electrodes 8a and 8b are provided at four positions facing each other. Has been done. Further, the electrodes 8a and 8b are provided outside the second substrate 3 in a plan view. The electrodes 8a and 8b are provided so as to be electrically connectable to various external devices that require a detection signal or the like from the element 4 such as an infrared detection element.

The materials constituting the electrodes 8a and 8b and the internal wiring are not particularly limited as long as they are wiring materials or electrode materials having excellent conductivity, and metal materials conventionally used in this field are limited. Can be used without. For example, as the electrodes 8a and 8b and the internal wiring, titanium nitride (TiN), an aluminum silicon alloy (AlSi), and titanium nitride (TiN) can be sequentially laminated by a sputtering method or the like.

According to the package 1 of the present embodiment, the first metal bonding film 5 and the second metal bonding film 6 have the above-mentioned uneven shape, and in the example shown in FIG. 4, the concave portion of the first metal bonding film 5 The 5A and the convex portion 6B and the concave portion 6A and the convex portion 6B of the second metal bonding film 6 are alternately combined and bonded, and the bonding allowance K of each metal bonding film is provided in a substantially C shape. As a result, the stress at the joint is dispersed in the horizontal and vertical directions, and the stress is effectively relieved. Therefore, even when the first substrate 2 and the second substrate 3 are joined at a high temperature, the stress is effectively relaxed. It is possible to prevent cracks and the like from occurring at the joint.
Therefore, it is possible to realize the package 1 having a simple configuration, low cost, and excellent productivity and element characteristics.

Further, according to the package 1 of the present embodiment, the first substrate 2 and the second substrate 3 are provided with the bonded body 50 composed of the above-mentioned first metal bonding film 5 and the second metal bonding film 6. When they are joined, a high sealing airtightness is obtained by metal diffusion bonding. Further, since unevenness and the like caused by the processing accuracy of the first substrate 2 and the second substrate 3 are absorbed, in addition to the improvement of the sealing airtightness, the internal electrical characteristics are also improved, and excellent element characteristics are obtained. can get.

Further, the convex body 31 provided on the second substrate 3 also has irregularities composed of concave portions and convex portions alternately arranged along the circumferential direction, similarly to the first metal bonding film 5 and the second metal bonding film 6. When configured in a shape, in addition to the action obtained by the uneven shape of the first metal bonding film 5 and the second metal bonding film 6, the stress at the joint is more effectively dispersed and the stress is relaxed. Is remarkably obtained.

Further, according to the package 1 of the present embodiment, the first substrate 2 and the second substrate 3 are made of a silicon substrate having excellent workability when processed by wet etching described in detail later, so that the element characteristics are further excellent. It will be.

Further, according to the package 1 of the present embodiment, the infrared detection element is adopted as the element 4, and the second substrate 3 is configured to be capable of transmitting infrared rays, so that cracks and the like are suppressed at the joint portion. Therefore, it is possible to realize an infrared sensor which is low in cost and has excellent productivity and element characteristics.

Next, as an example of processing related to various detections using the package 1 of the present embodiment, a case where an infrared detection element is used for the element 4 and a package is configured as an infrared sensor will be described.
First, when infrared rays enter from the upper surface 3b side of the second substrate 3 and pass through the second substrate 3, the element 4 composed of infrared detection elements detects the infrared rays and outputs a detection signal. The detection signal output from the element 4 passes through the internal wiring and the like (not shown) and is output from the plurality of electrodes 8a and 8b. The detection signals output from the plurality of electrodes 8a and 8b are transmitted to an external device to perform a predetermined operation.

[Package manufacturing method]
Next, the method of manufacturing the package 1 of the present embodiment will be described in detail with reference to FIGS. 5 and 6 (see also FIGS. 1 to 3 for the configuration of the package 1 as appropriate).
5 and 6 are views schematically explaining the manufacturing method of the package 1 of the present embodiment, and FIGS. 5 (a) and 5 (b) show wet silicon substrates in the step (2) described below. A process diagram showing a step of obtaining the second substrate 3 by etching, FIG. 5 (c) shows a step of forming the second metal bonding film 6 on the convex body 31 of the second substrate 3 in the step (3). It is a process diagram. 6 (a) is a process diagram showing a step of forming the first metal bonding film 5 on the upper surface (surface) 2a of the first substrate 2 in step (4), and FIG. 6 (b) is a process diagram showing step (6). ) Shows the step of obtaining the package 1 by joining the first substrate 2 and the second substrate 3, FIG. 4C shows the chips 8a and 8b being exposed by dicing the wafer. It is a process diagram which shows the step to make a dicing.

The method for manufacturing the package 1 of the present embodiment is, for example, a method for manufacturing the package 1 of the present embodiment as shown in FIGS. 1 and 2, and is a method including at least the following steps (1) to (6). is there.
Step (1): By etching the surface of the substrate material, a concave device region 22 accommodating the element 4 is formed to obtain a first substrate 2.
Step (2): By etching the surface of the substrate material, a convex body 31 having a plan view frame shape and a cavity (decompression space) formed on the element 4 so as to be surrounded by the convex body 31 in a plan view. A second substrate is obtained by forming a concave cavity region 32 for securing C.
Step (3): Recesses 6A in the shape of a plan view frame and at least a part in the circumferential direction are alternately arranged along the circumferential direction at the tip of the convex body 31 formed on the second substrate 3. A second metal bonding film 6 having an uneven shape composed of the convex portion 6B and the convex portion 6B is formed.
Step (4): At a position corresponding to the convex body 31 when the first substrate 2 and the second substrate 3 are superposed on the first substrate 2, in a plan view frame shape, at least one in the circumferential direction. The portions form a first metal bonding film 5 having an uneven shape composed of concave portions 5A and convex portions 5B arranged alternately along the circumferential direction in a plan view.
Step (5): The element 4 is arranged in the device region 22 formed on the first substrate 2.
Step (6): The first substrate 2 and the second substrate 3 are superposed so that the element 4 is arranged between the first substrate 2 and the second substrate 3, and the first metal bonding film 5 and the second metal By pressurizing the bonding film 6 with each other and performing metal diffusion bonding, the concave portion 5A and the convex portion 5B of the first metal bonding film 5 and the concave portion 6A and the convex portion 6B of the second metal bonding film 6 are overlapped and bonded. , The first substrate 2 and the second substrate 3 are joined.

First, in step (1), the surface of a substrate material, for example, a silicon substrate, is wet-etched to form a concave device region 22 for accommodating the element 4, and the first substrate 2 is manufactured (see FIG. 6A). ).
Specifically, in the step (1), first, a resist pattern (not shown) for forming a concave device region 22 by wet etching is formed on the surface of a silicon substrate as a substrate material by a photolithography method. To do.
Next, the surface of the silicon substrate is wet-etched to form the concave device region 22.
After that, the resist pattern is peeled off from the first substrate 2.

In the step (1), when the resist pattern is formed by the photolithography method, the resist pattern can be formed under conventionally known conditions by using, for example, a spin coating method.
Further, the wet etching conditions in the step (1) are not particularly limited, and for example, an etching solution such as KOH, which has been conventionally used for etching a silicon substrate, can be used. Further, as for each condition such as the temperature of the etching solution and the etching time, conventionally known conditions can be adopted without any limitation.

In the present embodiment, in parallel with carrying out the above step (1), in the step (2), the substrate material, for example, the surface (lower surface 3a) of the silicon substrate is etched to form a convex shape in a plan view frame. The second substrate 3 is manufactured by forming the body 31 and a concave cavity region 32 formed on the element 4 so as to be surrounded by the convex body 31 in a plan view and for securing the sealing space C.

That is, in the step (2), first, a silicon substrate 3A as a substrate material is prepared as shown in FIG. 5 (a).
Next, although detailed illustration is omitted, the convex body 31 and the cavity region 32 are wetted by applying a dry film resist to one surface (lower surface 3a) of the silicon substrate 3A and then patterning by a photolithography method. A resist pattern (not shown) for forming by etching is formed.

Next, as shown in FIG. 5 (b), one surface (lower surface 3a) of the silicon substrate 3A is wet-etched to form a convex body 31, and as shown in FIGS. 1 and 2. , A cavity region 32 surrounded by a convex body 31 in the shape of a plan view frame is formed (step (2)).

The second substrate 3 is obtained by the above step (2).
In the package 1 obtained by the manufacturing method of the present embodiment, the region corresponding to the cavity region 32 is the sealing space C.
After that, the resist pattern is peeled off from the second substrate 3.

Also in the step (2), when the resist pattern is formed by the photolithography method, the resist pattern can be formed under conventionally known conditions by using, for example, a spin coating method.
Further, the wet etching conditions in the step (2) are not particularly limited, and for example, an etching solution such as KOH, which has been conventionally used for etching a silicon substrate, can be used. Further, as for each condition such as the temperature of the etching solution and the etching time, conventionally known conditions can be adopted without any limitation.

Next, in the step (3), at the tip of the convex body 31 formed on the second substrate 3, at least a part in the circumferential direction in a plan view frame shape is alternately arranged along the circumferential direction in the plan view. A second metal bonding film 6 having an uneven shape composed of the arranged concave portions 6A and convex portions 6B is formed.
Specifically, first, as shown in FIG. 5B, a second metal bonding film is formed on the lower surface 3a side of the second substrate 3 obtained in the step (2) by a photolithography method such as a spray coating method. A resist pattern (not shown) for forming No. 6 is formed. At this time, a resist pattern is formed on the entire surface of the lower surface 3a of the second substrate 3 excluding the portion of the convex body 31 and the entire side surface of the convex body 31, and the tip of the convex body 31 is shown in the figure. A resist pattern is formed in a portion other than the portion corresponding to the second metal bonding film 6 having a concave-convex shape composed of the concave portion 6A and the convex portion 6B shown in 3 (a).

Next, as shown in FIG. 5C, a second metal bonding film 6 is formed at the tip of the convex body 31 by, for example, a sputtering method, a vapor deposition method, or a plating method. At this time, by appropriately selecting the material and the stacking order, the {Au layer (second bonding layer 62) / Ta layer (second base layer 61)} structure or {Al layer (second bonding layer 61)} structure as described above can be selected. It is composed of a thin film having a layer 62) / TiN layer (second base layer 61)} structure, and forms a second metal bonding film 6 having an uneven shape as shown in FIG. 3A.
After that, the resist pattern (not shown) is peeled off from the upper surface 2a of the first substrate 2.

Further, in the present embodiment, the above step (3) is carried out, and in the step (4), at a position corresponding to the convex body 31 when the first substrate 2 and the second substrate 3 are superposed. A first metal bonding film 5 having a concave-convex shape formed of concave portions 5A and convex portions 5B alternately arranged along the circumferential direction in a planar view frame shape and at least a part in the circumferential direction is formed.
Specifically, first, as shown in FIG. 6A, on the upper surface 2a of the first substrate 2 on which the device region 22 is formed, a first method is performed by a photolithography method such as a spray coating method as described above. A resist pattern (not shown) for forming the metal bonding film 5 is formed. At this time, a resist pattern is formed on the entire surface of the upper surface 2a of the first substrate 2 excluding the portion corresponding to the convex body 31 of the second substrate 3, and the concave portion 5A and the convex portion shown in FIG. 3B are formed. A resist pattern is formed in a portion other than the portion corresponding to the first metal bonding film 5 having an uneven shape composed of the portion 5B.

Next, for example, a first metal bonding film 5 having an uneven shape as shown in FIG. 3B is formed on the upper surface 2a of the first substrate 2 by a method such as a sputtering method, a vapor deposition method, or a plating method. (See also FIG. 6 (a)).

In step (4), by appropriately selecting the material and the stacking order, the {Au layer (first bonding layer 52) / Ta layer (first base layer 51)} structure or { The first metal bonding film 5 made of a thin film having an Al layer (first bonding layer 52) / TiN layer (first base layer 51)} structure can be formed. At this time, when the second metal bonding film 6 is composed of {Au layer (second bonding layer 62) / Ta layer (second base layer 61)}, the first metal bonding film 5 is also made of the same material. Form. In this case, the stacking order of each layer is set so that the Au layer (first bonding layer 52) of the first metal bonding film 5 and the Au layer (second bonding layer 62) of the second metal bonding film 6 are bonded. adjust.
Further, when the second metal bonding film 6 is composed of {Al layer (second bonding layer 62) / TiN layer (second base layer 61)}, the first metal bonding film 5 is also formed from the same material. In this case, the stacking order of each layer is set so that the Al layer (first bonding layer 52) of the first metal bonding film 5 and the Al layer (second bonding layer 62) of the second metal bonding film 6 are bonded. adjust.
Then, the resist pattern (not shown) is peeled off from the first substrate 2.

In the above steps (3) and (4), the uneven shape of the first metal bonding film 5 or the second metal bonding film 6 may be formed by periodically arranging them in the circumferential direction. That is, as shown in the examples shown in FIGS. 3A and 3B, the concave portion 5A and the convex portion 5B of the first metal bonding film 5 and the concave portion 6A and the convex portion 6B of the second metal bonding film 6 are formed. Each may be formed by arranging them periodically.

Further, in the present embodiment, as shown in FIG. 6A, the electrodes 8a and 8b and the figures are omitted by laminating a conductive material on the upper surface 2a of the first substrate 2 by a sputtering method. Form the internal wiring of. At this time, the electrode material used for the electrodes 8a and 8b and the wiring material used for the internal wiring are not particularly limited, but are formed by sequentially laminating TiN, AlSi, and TiN as described above, for example. can do.

Next, in the step (5), the element 4 is arranged in the concave device region 22 formed on the upper surface 2a of the first substrate 2 (see FIG. 6A and the like).

Next, in step (6), as shown in FIG. 6 (b), the first substrate 2 and the second substrate 3 are arranged so that the element 4 is arranged between the first substrate 2 and the second substrate 3. Are superposed, and the first substrate 2 and the second substrate 3 are joined. That is, the second metal bonding film 6 formed at the tip of the convex body 31 of the second substrate 3 and the first metal bonding film 5 formed on the upper surface 2a of the first substrate 2 are superposed and added to each other. The first substrate 2 and the second substrate 3 are bonded by expressing metal diffusion bonding by pressing. Further, in the step (6), the concave portion 5A and the convex portion 5B of the first metal bonding film 5 and the concave portion 6A and the convex portion 6B of the second metal bonding film 6 are joined by a bonding allowance K which is superposed. , The first substrate 2 and the second substrate 3 are joined.

Specifically, first, as shown in FIG. 6B, the first substrate 2 and the second substrate 3 are overlapped so as to abut the first metal bonding film 5 and the second metal bonding film 6. ..
Next, by pressurizing the first substrate 2 and the second substrate 3 with each other, metal diffusion bonding is developed between the first metal bonding film 5 and the second metal bonding film 6, and this portion is bonded. At this time, as shown in FIG. 4, the concave portions 5A and the convex portions 5B of the first metal bonding film 5 and the concave portions 6A and the convex portions 6B of the second metal bonding film 6 are alternately combined and superposed. Then, it is positioned so as to form a substantially C-shaped joint allowance K in a plan view.

The conditions for performing the above diffusion bonding, that is, the conditions for sealing the sealing space C of the package 1, are not particularly limited, but for example, the first metal bonding film 5 on the first substrate 2 side and the first 2 When the second metal bonding film 6 on the substrate 3 side is {Au layer (first bonding layer 52 or second bonding layer 62) / Ta layer (first underlying layer 51 or second underlying layer 61)} For example, it is preferable that the temperature condition is in the range of 300 to 350 ° C. and the pressing force is in the range of 450 to 900 kPa.
On the other hand, the first metal bonding film 5 and the second metal bonding film 6 are {Al layer (first bonding layer 52 or second bonding layer 62) / TiN layer (first underlying layer 51 or second underlying layer 61)}. In some cases, for example, the temperature condition is preferably in the range of 350 to 400 ° C., and the pressing force is preferably in the range of 27 to 60 MPa.

Further, the sealing width (bonding width) when the first substrate 2 and the second substrate 3 are bonded, that is, the maximum width of the first metal bonding film 5 and the second metal bonding film 6 is not particularly limited. On the other hand, in consideration of improvement of sealing airtightness and the like, the above sealing width is such that the first metal bonding film 5 and the second metal bonding film 6 have {Au layer (first bonding layer 52 or second bonding layer 62). ) / Ta layer (first base layer 51 or second base layer 61)}, for example, the range is preferably 0.15 to 0.30 mm. Further, the first metal bonding film 5 and the second metal bonding film 6 are {Al layer (first bonding layer 52 or second bonding layer 62) / TiN layer (first underlying layer 51 or second underlying layer 61)}. In some cases, the sealing width is preferably in the range of, for example, 0.03 to 0.1 mm.

Then, in the present embodiment, after the above step (6), as shown in FIG. 6 (c), a pair of facing edges on the second substrate 3 are diced along the dicing line L. The electrodes 8a and 8b are exposed and then individualized into chip units.
By each of the above steps, the package 1 of the present embodiment can be manufactured.
It should be noted that each of the above steps can be changed in the order of the steps or performed as the same step to the extent possible.

According to the manufacturing method of the package 1 of the present embodiment, in the step (3), the second metal bonding film 6 having the above-mentioned uneven shape is formed on the second substrate 3, and in the step (4), the first After forming the first metal bonding film 5 having the above-mentioned uneven shape on the substrate 2, in the step (6), the first metal bonding film 5 and the second metal bonding film 6 are alternately uneven. Metal diffusion bonding is performed so that they can be combined. At this time, since the bonding allowance K between the first metal bonding film 5 and the second metal bonding film 6 is formed in a substantially C shape, the stress in the entire joint is dispersed in the horizontal and vertical directions, and the stress is effective. Is relaxed. As a result, when the first substrate 2 and the second substrate 3 are joined at a high temperature, it is not necessary to control the coefficient of thermal expansion of each film formed on the substrate, and complicated process control is not required. It is possible to prevent cracks and the like from occurring at the joint without adding additional steps. Therefore, it is possible to produce a package having excellent element characteristics at low cost with high productivity without requiring complicated process control.

Further, in the manufacturing method of the present embodiment, the above steps (3) and (4) are provided, and the first metal bonding film 5 and the second metal bonding film 6 are formed at corresponding positions, and then the above. In step (6), the first metal bonding film 5 and the second metal bonding film 6 are metal diffusion bonded, and the first substrate 2 and the second substrate 3 are bonded to have high sealing airtightness. Package 1 is obtained. Further, since unevenness and the like caused by the processing accuracy of the first substrate 2 and the second substrate 3 are absorbed, in addition to the improvement of the sealing airtightness, the internal electrical characteristics are also improved, and the characteristics are excellent. Package 1 can be manufactured.

Further, according to the manufacturing method of the present embodiment, the uneven shapes of the first metal bonding film 5 and the second metal bonding film 6 are formed by periodically arranging them in the circumferential direction, whereby the first step (6) is performed. When the 1st substrate 2 and the 2nd substrate 3 are joined, the stress at the joining portion is dispersed in the horizontal direction and the vertical direction to stably obtain the action of relaxing the stress.

Further, according to the manufacturing method of the present embodiment, in the step (2), the convex body 31 has a concave-convex shape composed of concave portions and convex portions alternately arranged along the circumferential direction, similarly to the second metal bonding film. When formed so as to be, the first substrate 2 and the second substrate 3 are formed in the step (6) in addition to the action obtained by the uneven shape of the first metal bonding film 5 and the second metal bonding film 6 described above. When joining with, the stress at the joint is dispersed in the horizontal and vertical directions, and the stress is relieved remarkably.

Further, according to the manufacturing method of the present embodiment, in the steps (1) and (2), by using a silicon substrate having excellent processability by wet etching for the first substrate 2 and the second substrate 3, the step (1) In 6), the internal stress at the time of joining the first substrate 2 and the second substrate 3 is reduced, and the processing accuracy by the etching process is improved, so that the package 1 having further excellent element characteristics can be manufactured.

Further, according to the manufacturing method of the present embodiment, in the step (5), by arranging the infrared detection element as the element 4 in the device region, the stress generated in the joint portion when the substrates are bonded and sealed is generated. The infrared sensor can be manufactured as a package 1 which is alleviated, can prevent cracks and the like from being generated at the joint portion, is low in cost, and is excellent in productivity and element characteristics.

[Action effect]
As described above, according to the package 1 of the present embodiment, the stress at the joint portion is provided by providing the joint body 50 composed of the first metal joint film 5 and the second metal joint membrane having the above-mentioned uneven shape. Is dispersed horizontally and vertically to effectively relieve stress. As a result, even when the first substrate 2 and the second substrate 3 are joined at a high temperature, it is possible to prevent cracks and the like from occurring in the joined portion.
Therefore, it is possible to realize the package 1 having a simple configuration, low cost, and excellent productivity and element characteristics.

Further, according to the package manufacturing method of the present invention, in the above steps (3) and (4), the first metal bonding film 5 and the second metal bonding film 6 having the above uneven shape are formed. Then, in the step (6), the concave portions and the convex portions are overlapped with each other, and the first substrate 2 and the second substrate 3 are joined by metal diffusion joining, so that the stress at the joining portion is in the horizontal direction and Disperses vertically and stress is effectively relieved. This eliminates the need to control the coefficient of thermal expansion of each film formed on the substrate, eliminates the need for complicated process control, and causes cracks or the like at the joint without adding a new process. Can be prevented.
Therefore, it is possible to manufacture the package 1 which is inexpensive and has excellent element characteristics with high productivity without requiring complicated process control.

As described above, the package of the present invention relaxes the stress generated at the joint when the substrates are joined and sealed, and is excellent in productivity and element characteristics as well as low cost. Therefore, it is very suitable for applications in electronic devices and the like that require various highly reliable detection accuracy, for example, in mobile terminals, smartphones, sensor network devices, Internet of Things (IoT) technology, and the like.

1 ... Package 2 ... First substrate 2a ... Top surface 2b ... Bottom surface 22 ... Device area 3 ... Second substrate 3a ... Bottom surface 3b ... Top surface 31 ... Convex body 32 ... Cavity region 3A ... Silicon substrate 4 ... Element 50 ... Joined body 5 … First metal bonding film 5A… concave 5B… convex 51… first base layer 52… first bonding layer 6… second metal bonding film 6A… concave 6B… convex 61… second base layer 62… second bonding Layers 8a, 8b ... Electrode C ... Cavity (decompression space)
L ... Dicing lines F1, F2 ... Depth of recess (constriction depth)
L1, L2 ... Recess length K ... Joining allowance

Claims (10)

1st board and
An element provided on the upper surface side of the first substrate and
A plan view frame-shaped convex body joined to the first substrate and a flat surface to the lower surface side arranged on the first substrate side while covering the element on the upper surface side of the first substrate. A second substrate which is formed so as to be surrounded by the convex body visually and has a concave cavity region for securing a sealing space on the element.
The first metal bonding film is provided at the tip of the convex body formed on the second substrate in a plan view frame shape, and at a position corresponding to the convex body formed on the second substrate. A joint body formed by metal diffusion bonding with a first metal bonding film provided on the upper surface of the substrate in a plan view frame shape is provided.
The first metal bonding film and the second metal bonding film have an uneven shape in which at least a part in the circumferential direction is composed of concave portions and convex portions alternately arranged along the peripheral direction in a plan view. A package characterized in that the concave and convex portions of the first metal bonding film and the concave and convex portions of the second metal bonding film are overlapped and joined. The package according to claim 1, wherein the first metal bonding film and the second metal bonding film have a shape in which the uneven shape is periodically arranged in the circumferential direction. Further, the concave portions and the convex portions in which at least a part in the circumferential direction is alternately arranged along the circumferential direction so that the convex body corresponds to the uneven shape provided on the second metal bonding film. The package according to claim 1 or 2, wherein the package has a concavo-convex shape comprising. The package according to any one of claims 1 to 3, wherein the first substrate and the second substrate are made of a silicon substrate. The package according to any one of claims 1 to 4, wherein the element is an infrared detection element, and the second substrate is capable of transmitting infrared rays. at least,
A step (1) of obtaining a first substrate by forming a concave device region for accommodating an element by etching the surface of the substrate material.
By etching the surface of the substrate material, a convex body having a plan view frame shape and a concave cavity formed so as to be surrounded by the convex body in a plan view and securing a sealing space on the element. The step (2) of forming the region and obtaining the second substrate, and
At the tip of the convex body formed on the second substrate, at least a part in a plan view frame shape and in the circumferential direction is composed of concave portions and convex portions alternately arranged along the circumferential direction in a plan view. The step (3) of forming the second metal bonding film having an uneven shape, and
When the first substrate and the second substrate are superposed on the first substrate, at a position corresponding to the convex body, in a plan view frame shape, at least a part in the circumferential direction is in a plan view. A step (4) of forming a first metal bonding film having a concavo-convex shape composed of concave portions and convex portions alternately arranged along the circumferential direction.
The step (5) of arranging the element in the device region formed on the first substrate, and
The first substrate and the second substrate are overlapped so that the element is arranged between the first substrate and the second substrate, and the first metal bonding film and the second metal bonding film are formed. By pressurizing each other and performing metal diffusion bonding, the concave and convex portions of the first metal bonding film and the concave and convex portions of the second metal bonding film are overlapped and bonded, and the first substrate and the second Step (6) of joining the substrate and
A method of manufacturing a package, which comprises. The step (3) and the step (4) are characterized in that the uneven shape provided on the first metal bonding film or the second metal bonding film is periodically arranged and formed in the circumferential direction. The method for manufacturing a package according to claim 6. In the step (2), the convex body is further formed so that at least a part in the circumferential direction has a concave-convex shape composed of concave portions and convex portions alternately arranged along the circumferential direction.
In the step (3), the second metal bonding film is formed from concave portions and convex portions in which at least a part in the circumferential direction is alternately arranged along the circumferential direction so as to cover the tip of the convex body. The method for manufacturing a package according to claim 6 or 7, wherein the package is formed so as to have an uneven shape. The package manufacturing method according to any one of claims 6 to 8, wherein the step (1) and the step (2) use a silicon substrate as the substrate material. The step (5) according to any one of claims 6 to 9, wherein the infrared detection element is arranged in the device region formed on the first substrate as the element. How to make the package.

Images