JP7233982B2 - Package and package manufacturing method - Google Patents

Description

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

For example, packages used in semiconductor devices such as infrared sensors generally include 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. Also, the second substrate is bonded to the upper surface of the first substrate while covering the sensor element. A sealed space secured above the sensor element covered by the first substrate and the second substrate is a decompressed space (cavity).

Packages such as those described above, especially infrared sensors, need to be thermally isolated from the external system in order to stabilize and improve sensor characteristics. be done. Conventionally, in a package in which the inside of a cavity is vacuum-sealed, for example, gold (Au): 80% and tin (Sn ): 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 together at a high temperature. However, when the first substrate and the second substrate are bonded at high temperatures, cracks may occur in the bonded portion due to the difference in thermal expansion coefficient. 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). .

Japanese Patent Publication No. 2017-527113

When adopting a configuration in which a stress relaxation buffer layer is provided at the junction as in the technique described in Patent Document 1, the thermal expansion coefficient of this stress relaxation buffer layer is a value larger than the thermal expansion coefficient of the surface portion of the substrate. and 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. If it is implemented together with the process control of , there is a problem that the process time becomes long and the manufacturing cost increases. Furthermore, there is the problem that the process control that considers the thermal expansion coefficient of the stress relaxation buffer layer and the deposition of multiple films on the substrate requires a large amount of labor from the viewpoint of ensuring process quality. .

The present invention has been made in view of the above problems. The purpose is to provide a package with excellent characteristics.
In addition, the present invention can alleviate the stress generated in the joint portion when the substrates are joined and sealed without requiring complicated process management, and can suppress the occurrence of cracks or the like in the joint portion. It is an object of the present invention to provide a package manufacturing method capable of manufacturing a package having excellent device characteristics with high productivity.

In order to solve the above problems, the package of the present invention includes a first substrate, an element provided on the upper surface side of the first substrate, and a state in which the element is covered on the upper surface side of the first substrate. On the lower surface side arranged on the side of the first substrate, a projecting body having a frame shape in plan view to be bonded to the first substrate, and a projecting body formed so as to be surrounded by the projecting body in plan view, and sealing on the element. a second substrate having a recessed cavity region for securing a sealing space; a second metal bonding film provided in a frame shape in a plan view at the tip of the protrusion formed on the second substrate; a bonded body formed by metal diffusion bonding with a first metal bonding film provided in a frame shape in a plan view on the upper surface of the first substrate at a position corresponding to the convex body formed on the two substrates, At least a part of the first metal bonding film and the second metal bonding film in a circumferential direction has an uneven shape composed of concave portions and convex portions alternately arranged along the circumferential direction in plan view, and The recesses and protrusions of the first metal bonding film and the recesses and protrusions of the second metal bonding film are superimposed and bonded, and the protrusions are provided on the second metal bonding film. At least a part in the circumferential direction has an uneven shape composed of concave portions and convex portions arranged alternately along the circumferential direction so as to correspond to the uneven shape.

According to the present invention, as described above, the frame-shaped first metal bonding film and the second metal bonding film have an uneven shape composed of recesses and protrusions alternately arranged along the circumferential direction, and , the first metal bonding film and the second metal bonding film are bonded with their recesses and projections superimposed on each other, so that the stress in the bonding portion is dispersed in the horizontal and vertical directions, and the stress is effectively released. Therefore, even when the first substrate and the second substrate are bonded at a high temperature, cracks or the like can be prevented from occurring in the bonded portion.
In addition, since the bonded body composed of the first metal bonding film and the second metal bonding film is provided, when the first substrate and the second substrate are bonded, high sealing and airtightness can be obtained by metal diffusion bonding. be done. In addition, since the irregularities 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 electrical characteristics inside are improved, and the excellent device characteristics are obtained. can get.
Further, similarly to the second metal bonding film, the convex body has an uneven shape composed of concave portions and convex portions arranged alternately along the circumferential direction, so that the first metal bonding film and the second metal bonding film In addition to the effect obtained by the uneven shape, the effect of more effectively dispersing the stress in the joint and relieving the stress can be remarkably obtained.
Therefore, it is possible to realize a package with a simple structure, low cost, and excellent productivity and device characteristics.

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

According to the present invention, since the uneven shapes of the first metal bonding film and the second metal bonding film are periodically arranged in the circumferential direction, the above-described stress at the bonding portion is reduced in the horizontal direction and the By dispersing in the vertical direction, the effect of relieving stress can be stably obtained.

Moreover, in the package of the present invention, it is preferable to employ a configuration in which the first substrate and the second substrate are silicon substrates in the above configuration.

According to the present invention, since the first substrate and the second substrate are made of a silicon substrate with excellent workability, the internal stress due to bonding is reduced, and the processing accuracy by the etching process is improved. will be excellent.

Further, in the package of the present invention, in the above configuration, it is possible to 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-described package structure and an infrared detection element as an element, cracks or the like are suppressed from occurring in the joints, and the cost is low and productivity and the element are improved. An infrared sensor can be realized as a package with excellent characteristics.

The method for manufacturing a package of the present invention includes at least the step (1) of etching the surface of a substrate material to form a concave device region for housing an element to obtain a first substrate, and etching the surface of the substrate material. As a result, a frame-shaped projecting body in plan view and a recessed cavity region formed so as to be surrounded by the projecting body in plan view and for securing a sealing space above the element are formed. and a step (2) of obtaining a second substrate by the step (2) of obtaining a second substrate, and a step (2) in which at least a portion in the circumferential direction of a frame shape in a plan view extends along the circumferential direction in a plan view at the tip of the convex body formed on the second substrate. step (3) of forming a second metal bonding film having a concave-convex shape composed of concave portions and convex portions that are alternately arranged on each other; An uneven shape having a frame shape in plan view and having at least a portion in the circumferential direction of concave and convex portions alternately arranged along the circumferential direction in plan view at a position corresponding to the convex body when combined. a step (4) of forming a first metal bonding film having The first substrate and the second substrate are overlapped so that the element is arranged between them, and the first metal bonding film and the second metal bonding film are pressed against each other for metal diffusion bonding. and a step (6) of superimposing and bonding the concave and convex portions of the first metal bonding film and the concave and convex portions of the second metal bonding film to bond the first substrate and the second substrate; , is provided.

According to the present invention, as described above, in the step (3), the second metal bonding film having the uneven shape is formed on the tip of the frame-shaped protrusion on the second substrate, and in the step (4), After forming a first metal bonding film having an uneven shape on the first substrate at positions corresponding to the convex bodies of the second substrate, in step (6), the first metal bonding film and the second metal bonding film are formed. By overlapping each unevenness and performing metal diffusion bonding, a bonding allowance between each metal bonding film is formed. By forming such a joint margin, the stress in the joint is dispersed in the horizontal and vertical directions, and the stress is effectively relieved. As a result, when the first substrate and the second substrate are bonded at a high temperature, there is no need to manage the coefficient of thermal expansion of each film formed on the substrate, and no complicated process control is required. It is possible to prevent cracks or the like from occurring in the joints without adding
Further, the above-described steps (3) and (4) are provided to form the first metal bonding film and the second metal bonding film at corresponding positions, and then in the above-described step (6), the second metal bonding film is formed. By performing metal diffusion bonding of the first metal bonding film and the second metal bonding film, and bonding the first substrate and the second substrate together, a package having high airtightness can be obtained. In addition, since the unevenness caused by the processing accuracy of the first substrate and the second substrate is absorbed, in addition to the improvement of the sealing airtightness, the electrical characteristics inside are improved, and the package having excellent characteristics is obtained. manufacturing becomes possible.
Therefore, it is possible to manufacture inexpensive packages excellent in element characteristics with good productivity without requiring complicated process control.

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

According to the present invention, by forming the uneven shapes provided on the first metal bonding film and the second metal bonding film periodically in the circumferential direction, the first substrate and the second substrate are formed in the above step (6). , the stress at the joint is dispersed in the horizontal and vertical directions, and the effect of relieving the stress is stably obtained.

Further, in the method for manufacturing a package of the present invention, in the configuration described above, the step (2) further comprises: at least a portion of the convex bodies arranged alternately along the circumferential direction. The second metal bonding film is formed to have an uneven shape composed of concave portions and convex portions, and the step (3) causes the second metal bonding film to cover the tips of the convex bodies so that at least a portion thereof in the circumferential direction is: A method of forming an uneven shape composed of concave portions and convex portions arranged alternately along the circumferential direction may be employed.

According to the present invention, similarly to the second metal bonding film, the protrusions are formed in an uneven shape composed of recesses and protrusions alternately arranged along the circumferential direction, thereby forming the first metal bonding film and the first metal bonding film. In addition to the effect obtained by the uneven shape of the two-metal bonding film, the stress at the bonding portion when bonding the first substrate and the second substrate in the above step (6) is distributed horizontally and vertically. An effect of relieving stress can be obtained remarkably.

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

According to the present invention, by using a silicon substrate with excellent workability for the first substrate and the second substrate, the internal stress when bonding the first substrate and the second substrate in the step (6), which is a post-process, is reduced. is reduced and the processing accuracy of the etching process is improved, making it possible to manufacture a package with even better device characteristics.

Further, in the package manufacturing method of the present invention, in the above configuration, the step (5) adopts a method of arranging an infrared detection element as the element in the device region formed on the first substrate. good too.

According to the present invention, the package structure obtained by the above steps is provided, and the infrared detection element as an element is arranged in the device region. It becomes possible to manufacture an infrared sensor as a package with excellent productivity and device characteristics.

According to the package of the present invention, by providing the above configuration, the stress in the joints is distributed in the horizontal direction and the vertical direction, and the stress is effectively relieved. It is possible to prevent cracks or the like from occurring in the joint even if the joint is made with Therefore, it is possible to realize a package with a simple structure, low cost, and excellent productivity and device characteristics.

Further, according to the package manufacturing method of the present invention, by adopting the above-described method, the stress in the joint is dispersed in the horizontal and vertical directions, and the stress is effectively relieved. This eliminates the need for managing the coefficient of thermal expansion of each film, which eliminates the need for complicated process control, and prevents cracks and the like from occurring in the joints without adding a new process. Therefore, it is possible to manufacture inexpensive packages excellent in element characteristics with good productivity without requiring complicated process control.

BRIEF DESCRIPTION OF THE DRAWINGS It is a top view which illustrates typically the package which is embodiment of this invention. FIG. 2 is a diagram schematically explaining a package that is an embodiment of the present invention, and is a cross-sectional view taken along the line II shown in FIG. 1; 3A is a plan view showing a second metal bonding film, and FIG. 3B is a plan view showing a first metal bonding film; FIG. It is a diagram. FIG. 3B is a view schematically explaining a package that is an embodiment of the present invention, in which the second metal bonding film shown in FIG. 3A and the first metal bonding film shown in FIG. FIG. 10 is a schematic diagram showing the shape of a bonding margin where bonding films overlap each other in a bonded portion. 5(a) and 5(b) are diagrams schematically illustrating a method for manufacturing a package that is an embodiment of the present invention, and FIGS. 5(a) and 5(b) are steps of obtaining a second substrate by wet etching the substrate in step (2). FIG. 5C 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). 6(a) schematically illustrates a method for manufacturing a package according to an embodiment of the present invention, and FIG. 6(a) shows a step of forming a first metal bonding film on the surface of a first substrate in step (4); , a process diagram showing the step of arranging elements in the device region in step (5), and FIG. 6(b) shows the step of obtaining a package by bonding the first substrate and the second substrate in step (6). FIG. 6C is a process diagram showing a step of exposing the electrodes by dicing the wafer and forming chips.

Embodiments of a package and a method for manufacturing a package according to the present invention will be given below, 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 explanation, in order to make the features of the package of the present invention easier to understand, there are cases where the characteristic parts are enlarged for convenience, and the dimensional ratios of each component are not actual. may differ. Also, the materials, dimensions, and the like exemplified in the following description are examples, and the present invention is not limited to them, and can be implemented with appropriate modifications within the scope of the invention.

[Package configuration]
The configuration of the package of this embodiment will be described below.
FIG. 1 is a plan view schematically explaining a package 1 of this embodiment, and FIG. 2 is a cross-sectional view of the package 1 shown in FIG. 1 taken along the line II. 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. FIG. 3B is a diagram showing the shape of a bonding margin K where the respective bonding films are overlapped at a bonding portion where the two metal bonding film 6 and the first metal bonding film 5 shown in FIG. 3B are superimposed and bonded.

As shown in FIGS. 1 and 2, the package 1 of this 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 configured with various sensor devices, semiconductor devices, etc. by providing the element 4 therein.

More specifically, the package 1 of the present embodiment includes a first substrate 2, an element 4 provided on the top surface 2a side of the first substrate 2, and a On the side of the lower surface 3a that is joined and arranged on the side of the first substrate 2, a convex body 31 that has a frame shape in a plan view and that is surrounded by the convex body 31 in a plan view is formed. , and a second substrate 3 having a recessed cavity region 32 for securing a sealing space (depressurized space/cavity) C above the element 4 . As shown in FIG. 1, the package 1 of this embodiment is provided with electrodes 8a and 8b for outputting detection signals.

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

In the package 1 of the present embodiment, at least a portion of the first metal bonding film 5 and the second metal bonding film 6 that constitute the bonded body 50 in the circumferential direction (longitudinal direction) of the frame shape in plan view is circumferential. It has an uneven shape composed of concave portions 5A and 6A and convex portions 5B and 6B arranged alternately along the direction, and 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 have an uneven shape. and the convex portion 6B are overlapped and joined. More specifically, 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 superimposed so as to be alternately combined, so that the It is joined by a C-shaped joining allowance K (see also FIGS. 3(a), (b) and 4).
In the example shown in FIG. 1, the first metal bonding film 5 and the second metal bonding film 6 forming the bonded body 50 are configured such that the uneven shape is provided over the entire circumference in the circumferential direction. , unevenness is provided so as to have a symmetrical shape in both width directions of each bonding film.

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

The first substrate 2 is a base substrate of the package 1 and is made of, for example, a silicon substrate. Further, the first substrate 2 is formed in a rectangular shape in plan view in the example shown in FIG. A device region 22 for disposing an element 4, which will be described later, is formed in a concave shape on the upper surface 2a of the first substrate 2. In the illustrated example, the device region 22 is provided approximately in the center in plan view. there is

The first substrate 2 can be obtained by forming the device region 22 by wet etching a silicon substrate. The device region 22 is, for example, a region formed in a rectangular shape in plan view.
Further, the planar view shape of the first substrate 2 is not limited to a substantially rectangular shape as in the illustrated example, and various shapes can be adopted according to the planar 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 substantially flat except for the device region 22 portion.

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, as described above. Further, the element 4 outputs the detection signal to the outside through the electrodes 8a and 8b.

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

Although not shown in FIGS. 1 and 2, etc., in the package 1 of the present embodiment, an insulating layer is formed around the device region 22 on the first substrate 2, around the electrodes 8a and 8b, and the like. may be provided. Specifically, an insulating layer (not shown) can be provided in a region outside the element 4 on the upper surface 2a side of the first substrate 2 so as to surround the element 4 in plan view. This insulating layer is made of an insulating material, 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, like the first substrate 2, is made of, for example, a silicon substrate. Further, the second substrate 3 in the illustrated example is formed in a rectangular shape in plan view, like the first substrate 2 . In addition, the second substrate 3 has a frame-shaped convex body 31 in the vicinity of the edge when viewed from above, and is formed roughly like a lid. Further, the area inside the convex body 31 in the plan view of the second substrate 3 includes convexes provided on the upper surface 2a of the first substrate 2 and the lower surface 3a of the second substrate 3, as will be described later in detail. A sealed space C is formed by the cavity region 32 when the shaped body 31 is combined and joined.
Note that the cavity region 32 in the illustrated example has a rectangular shape in plan view.
In addition, the convex body 31 in the illustrated example is formed so that its side portions are inclined according to the processing conditions for wet etching, which will be described later in detail.

The second substrate 3 is superimposed so as to be substantially parallel to the first substrate 2 .
Further, the planar view shape of the second substrate 3 is not limited to a substantially rectangular shape as in the illustrated example, as in the case of the first substrate 2 . and corresponding shapes.
Further, the second substrate 3 is configured to transmit infrared rays when the element 4 is an infrared detection element.

As will be described later in detail, the second substrate 3 has a convex body 31 which is at least partly formed 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 employ a configuration having an uneven shape.

Moreover, in the package 1 of the present embodiment, the first substrate 2 and the second substrate 3 are preferably made of silicon substrates. In this way, since the first substrate 2 and the second substrate 3 are made of silicon substrates with excellent workability, the internal stress due to bonding is reduced, and the processing accuracy by the etching process is improved. will be excellent.

The bonding 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 bonds the first substrate 2 and the second substrate 3, as described above. . As shown in FIG. 2, the bonding body 50 includes the second metal bonding film 6 provided at the tip of the projection 31 formed on the second substrate 3 and the second metal bonding film 6 on the upper surface 2a of the first substrate 2. It is composed of a first metal bonding film 5 provided at a position corresponding to the convex body 31 formed on the substrate 3, and metal diffusion bonding is performed between them. Also, as shown in FIG. 1, the joined body 50 is configured in a substantially frame shape in a plan view.

A bonded body 50 provided in the package 1 bonds the first substrate 2 and the second substrate 3 to form a sealed space C surrounded by the first substrate 2, the second substrate 3, and the bonded body 50. do.
In addition, the bonding body 50 includes the projections 31 formed on the second substrate 3 and the portions where the first metal bonding film 5 is formed on the upper surface 2 a of the first substrate 2 , as well as the first substrate 2 and the second substrate 3 . constitutes a joint for joining between

More specifically, the bonded body 50 is composed of a first base layer 51 arranged on the upper surface 2 a of the first substrate 2 and a first bonding layer 52 laminated on the first base layer 51 . 1 metal bonding film 5; and a metal bonding film 6 .
The first metal bonding film 5 and the second metal bonding film 6 shown in FIG. 2 are rectangular in plan view and formed in a frame shape.

The first base layer 51 and the second base layer 61 are respectively bonded to the top surface 2a of the first substrate 2 or the tip of the convex body 31 of the second substrate 3 . By providing each base layer 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 bodies 31 of the second substrate 3 . spliced.

The first underlayer 51 and the second underlayer 61 are each formed in a thin film form on the upper surface 2a of the first substrate 2 or at the tips of the convex bodies 31 of the second substrate 3 using a conductive metal material. It is
Materials for the first underlayer 51 and the second underlayer 61 are not particularly limited, but thin films made of, for example, tantalum (Ta) or titanium nitride (TiN) are preferable.
Also, 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 on the lower surface 2b side of the first substrate 2, for example, but may be provided on the upper surface 2a side of the first substrate 2 as well.

The first bonding layer 52 and the second bonding layer 62 are laminated on the first base layer 51 and the second base layer 61, respectively, as described above.
Materials for the first bonding layer 52 and the second bonding layer 62 are not particularly limited. And gold (Au) is used as the material of the second bonding layer 62 . Further, when titanium nitride is used as the material of the first base layer 51 and the second base layer 61, aluminum (Al) is used as the material of the first bonding layer 52 and the second bonding layer 62. FIG.

In this embodiment, the first bonding layer 52 and the second bonding layer 62 are configured to be bonded with the same material. That is, the first bonding layer 52 and the second bonding layer 62 are both configured to include the same material, either gold (Au) or aluminum (Al).

When the joined body 50 is made of the above materials, the thickness of each layer is not particularly limited. On the other hand, in consideration of electrical characteristics, bonding strength, etc., when the first base layer 51 and the second base layer 61 are made of tantalum, and the first bonding layer 52 and the second bonding layer 62 are made of gold, is, for example, {first bonding layer 52 (or second bonding layer 62): 0.5 nm to 2 μm/first underlayer 51 (or second underlayer 61): 0.05 to 0.2 μm}. preferably.
Similarly, when the first underlayer 51 and the second underlayer 61 are made of titanium nitride, and the first bonding layer 52 and the second bonding layer 62 are made of aluminum, for example, {first bonding layer 52 ( or second bonding layer 62): 1 to 3 μm/first underlayer 51 (or second underlayer 61): 0.05 to 0.5 μm}.

In the present embodiment, by configuring the joined body 50 with the above-described layered structure, when the first substrate 2 and the second substrate 3 are superimposed and pressed, the first 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 can have a strong bonding structure, and the first substrate 2 and the second substrate 3 can be firmly bonded while improving the sealing performance in the sealing space C.

In addition, in the present embodiment, the bonded body 50 is not limited to being made of the above materials and metal diffusion bonded. For example, each layer of the bonded body 50 may be composed of gold (Au) or tin (Sn) and may be Au—Sn eutectic bonded. In this case, for example, the first underlayer 51 and the second underlayer 61, and the first bonding layer 52 and the second bonding layer 62 are each formed from an Au—Sn eutectic alloy, heated and melted to the eutectic temperature. Thus, 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. Thereby, the first substrate 2 and the second substrate 3 can be bonded.

As shown in FIGS. 3A and 3B, the bonded body 50 provided in the package 1 of the present embodiment includes the first metal bonding film 5 and the second metal bonding film 6 having a frame-like shape in a plan view. At least a portion in the circumferential direction (longitudinal direction) has a concavo-convex shape formed by concave portions 5A, 6A and convex portions 5B, 6B arranged alternately along the circumferential direction. . In the example shown in FIG. 4, the first metal bonding film 5 and the second metal bonding film 6 are formed by forming 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 being superimposed so that the portions 6B are alternately combined, they are joined by a joint margin K that is substantially C-shaped (substantially U-shaped) 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 are formed in the uneven shape described above, so that the bonding margin K is formed in a substantially C shape. When the metal bonding film 5 and the second metal bonding film 6 are superimposed and bonded at high temperature, the effect of dispersing the stress generated in the bonding portion in the horizontal and vertical directions is obtained. As a result, the stress in and around the joint is effectively relieved, so that cracks and the like can be prevented 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. It is preferable that the dimension is about 1/4 to 1/3 of the total width H1 of the metal bonding film 5 and the total width H2 of the second metal bonding film 6. FIG. For example, when the full 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 recesses 5A and 6A are preferably in the range of 25 to 30 μm. .
In addition, the length L1 of the concave portion 5A of the first metal bonding film 5 and the length L2 of the concave portion 6A of the second metal bonding film 6 in the circumferential direction are also not particularly limited. The dimensions can range from about the same as the depths F1 and F2 to about the same as the full widths H1 and H2 of the first metal bonding film 5 and the second metal bonding film 6 . For example, when the full 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 recesses 5A and 6A are preferably in the range of 25 to 100 μm. .
By setting the full widths H1 and H2 of the first metal bonding film 5 and the second metal bonding film 6, the recesses 5A and 6A, and the lengths L1 and L2 of the metal bonding films 5 and 6 to the ranges described above, the bonding portions as described above can be obtained. By dispersing the stress generated in the horizontal direction and the vertical direction, the effect of relieving the stress can be obtained more effectively.

Also, the dimension of the bonding allowance K between the first metal bonding film 5 and the second metal bonding film 6 is not particularly limited. preferably secured. In this case, for example, if the alignment accuracy when positioning the first substrate 2 and the second substrate 3 is ±10 μm, the minimum overlapping dimension at each position of the bonding margin 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 in the bonding portion as described above is dispersed in the horizontal and vertical directions. As a result, the effect of relaxing the stress can be obtained more stably.

As will be described later in the description of the manufacturing method, providing the first metal bonding film 5 and the second metal bonding film 6 with the uneven shape as described above is effective for the first metal bonding film 5 or the second metal bonding film 5 . Each step of forming the film 6 can be carried out simultaneously. Therefore, since there is no need to provide a new process, the package 1 with excellent productivity and device characteristics can be obtained without increasing the manufacturing cost.

In addition, the first metal bonding film 5 and the second metal bonding film 6 may be configured such that the uneven shapes are periodically arranged in the circumferential direction. That is, as 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 Each may be arranged periodically. Also in this case, the effect of dispersing the stress in the joint in the horizontal direction and the vertical direction and relaxing the stress as described above 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 of the frame shape.

The upper surface 2a of the first substrate 2 is provided with electrodes 8a and 8b and internal wiring (not shown).
The electrodes 8a and 8b are electrically connected to the element 4 via internal wiring (not shown) or the like, and output signals detected 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 edges facing each other. It is Further, the electrodes 8a and 8b are provided outside the second substrate 3 in plan view. The electrodes 8a and 8b are provided so as to be electrically connectable to various external devices that require signals detected by the element 4 such as an infrared detection element.

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 not limited at all. 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.

According to the package 1 of the present embodiment, the first metal bonding film 5 and the second metal bonding film 6 have the uneven shapes as described above, and in the example shown in FIG. 5A and protrusions 6B are alternately combined with the recesses 6A and protrusions 6B of the second metal bonding film 6, and the bonding allowance K of each metal bonding film is provided in a substantially C shape. As a result, the stress in the bonding portion is dispersed in the horizontal and vertical directions, and the stress is effectively relieved. It is possible to prevent cracks or the like from occurring in the joint.
Therefore, it is possible to realize the package 1 with a simple structure, low cost, and excellent productivity and device characteristics.

Further, according to the package 1 of the present embodiment, the first substrate 2 and the second substrate 3 are separated by providing the bonded body 50 composed of the first metal bonding film 5 and the second metal bonding film 6 described above. When the two are joined, the metal diffusion bonding provides a high sealing hermeticity. Furthermore, since the 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 electrical characteristics inside are improved, and the excellent element characteristics are obtained. can get.

Moreover, similarly to the first metal bonding film 5 and the second metal bonding film 6, the convex body 31 provided on the second substrate 3 also has unevenness composed of concave portions and convex portions arranged alternately along the circumferential direction. In the case of the configuration having the shape, the stress in the joint portion is more effectively dispersed and the stress is relieved in addition to the effect obtained by the uneven shapes of the first metal bonding film 5 and the second metal bonding film 6. is remarkably obtained.

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

In addition, 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 transmit infrared rays, thereby suppressing cracks or the like at the joints. It is possible to realize an infrared sensor which is low in cost and excellent in 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 as the element 4 and the 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, which is an infrared detecting element, detects the infrared rays and outputs a detection signal. A detection signal output from the element 4 is output from a plurality of electrodes 8a and 8b through internal wiring or the like (not shown). 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, a method for manufacturing the package 1 of this embodiment will be described in detail with reference to FIGS.
5 and 6 are diagrams for schematically explaining the method for manufacturing the package 1 of the present embodiment, and FIGS. A process diagram showing a step of obtaining the second substrate 3 by etching. FIG. 5C shows a step of forming the second metal bonding film 6 on the convex bodies 31 of the second substrate 3 in step (3). It is a process chart. FIG. 6A is a process diagram showing the step of forming the first metal bonding film 5 on the upper surface (surface) 2a of the first substrate 2 in process (4), and FIG. ) shows the step of obtaining the package 1 by bonding the first substrate 2 and the second substrate 3 in FIG. It is a process drawing which shows the step which converts into.

The method for manufacturing the package 1 of the present embodiment is, for example, a method of manufacturing the package 1 of the present embodiment as shown in FIGS. 1 and 2, and includes at least the following steps (1) to (6) be.
Step (1): The first substrate 2 is obtained by etching the surface of the substrate material to form a concave device region 22 for housing the element 4 .
Step (2): By etching the surface of the substrate material, a convex body 31 having a frame shape in a plan view and a cavity (a reduced pressure space) are formed above the element 4 so as to be surrounded by the convex body 31 in a plan view. A concave cavity region 32 for securing C is formed to obtain a second substrate.
Step (3): Concave portions 6A that are frame-shaped in plan view and at least partially circumferentially arranged alternately along the circumferential direction in plan view at the tips of the convex bodies 31 formed on the second substrate 3. and a second metal bonding film 6 having an uneven shape composed of convex portions 6B.
Step (4): On the first substrate 2, at a position corresponding to the convex body 31 when the first substrate 2 and the second substrate 3 are superimposed, a frame shape in a plan view is formed at least in the circumferential direction. 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 plan view is formed.
Step (5): Arrange the element 4 in the device region 22 formed on the first substrate 2 .
Step (6): The first substrate 2 and the second substrate 3 are overlapped 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 are bonded together. 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 by performing metal diffusion bonding by mutually pressurizing the bonding film 6. , to bond the first substrate 2 and the second substrate 3 together.

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 housing the element 4, thereby fabricating the first substrate 2 (see FIG. 6A). ).
Specifically, in step (1), first, a resist pattern (not shown) is formed by photolithography on the surface of a silicon substrate, which is a substrate material, for forming a recessed device region 22 by wet etching. do.
A recessed device region 22 is then formed by wet etching the surface of the silicon substrate.
After that, the resist pattern is removed from the first substrate 2 .

In step (1), when forming a resist pattern by photolithography, the resist pattern can be formed under conventionally known conditions using, for example, a spin coat method.
Also, wet etching conditions in step (1) are not particularly limited, and for example, an etchant such as KOH, which has been conventionally used for etching silicon substrates, can be used. Further, as for the conditions such as the temperature of the etchant and the etching time, conventionally known conditions can be employed without any restrictions.

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

That is, in step (2), first, a silicon substrate 3A as a substrate material is prepared as shown in FIG. 5(a).
Next, although not shown in detail, a dry film resist is applied to one surface (lower surface 3a) of the silicon substrate 3A, and then patterned by photolithography to wet the protrusions 31 and the cavity regions 32. A resist pattern (not shown) is formed by etching.

Next, as shown in FIG. 5(b), one surface (lower surface 3a) of the silicon substrate 3A is wet-etched to form convex bodies 31, as shown in FIGS. , forming a cavity region 32 surrounded by a frame-shaped convex body 31 in plan view (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 area corresponding to the cavity area 32 is the sealing space C. As shown in FIG.
After that, the resist pattern is removed from the second substrate 3 .

Also in step (2), in forming a resist pattern by photolithography, the resist pattern can be formed under conventionally known conditions using, for example, spin coating or the like.
Also, wet etching conditions in step (2) are not particularly limited, and for example, an etchant such as KOH, which has been conventionally used for etching silicon substrates, can be used. Further, as for the conditions such as the temperature of the etchant and the etching time, conventionally known conditions can be employed without any restrictions.

Next, in the step (3), at least a portion of the convex body 31 formed on the second substrate 3 has a frame shape in plan view, and at least a part thereof in the circumferential direction alternately along the circumferential direction in plan view. A second metal bonding film 6 having an uneven shape composed of 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 step (2) by photolithography such as spray coating. 6, a resist pattern (not shown) 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 protrusions 31 and on the entire side surfaces of the protrusions 31. A resist pattern is formed on a portion other than the portion corresponding to the second metal bonding film 6 having the concave-convex shape composed of the concave portions 6A and the convex portions 6B shown in 3(a).

Next, as shown in FIG. 5C, the second metal bonding film 6 is formed on the tips of the convex bodies 31 by a method such as sputtering, vapor deposition, or plating. At this time, by appropriately selecting the material and the order of lamination, the {Au layer (second bonding layer 62)/Ta layer (second base layer 61)} structure as described above, or the {Al layer (second bonding layer) Layer 62)/TiN layer (second base layer 61)} structure thin film, the second metal bonding film 6 having an uneven shape as shown in FIG. 3A is formed.
After that, the resist pattern (not shown) is removed from the upper surface 2a of the first substrate 2. Next, as shown in FIG.

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

Next, 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 sputtering, vapor deposition, or plating. (See also FIG. 6(a)).

In the step (4), by appropriately selecting the material and the order of lamination, the {Au layer (first bonding layer 52)/Ta layer (first underlayer 51)} structure as described above, or { 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 changed 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.
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 of the same material. In this case, the stacking order of each layer is changed 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.
After that, the resist pattern (not shown) is removed from the first substrate 2 .

In the steps (3) and (4) described above, the uneven shapes of the first metal bonding film 5 or the second metal bonding film 6 may be formed so as to be arranged periodically in the circumferential direction. That is, as 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 They may be formed by arranging them periodically.

Further, in the present embodiment, as shown in FIG. 6A, a conductive material is laminated on the upper surface 2a of the first substrate 2 by a sputtering method so that the electrodes 8a and 8b and not shown 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. can do.

Next, in 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. 6B, the first substrate 2 and the second substrate 3 are separated so that the element 4 is arranged between the first substrate 2 and the second substrate 3. are superimposed on each other, and the first substrate 2 and the second substrate 3 are joined. That is, the second metal bonding film 6 formed on 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 overlapped and pressed together. The first substrate 2 and the second substrate 3 are bonded by applying pressure to develop metal diffusion bonding. Further, in 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 overlapped with each other so as to be bonded by a bonding allowance K. , to bond the first substrate 2 and the second substrate 3 together.

Specifically, first, as shown in FIG. 6B, the first substrate 2 and the second substrate 3 are overlapped so that the first metal bonding film 5 and the second metal bonding film 6 are butted against each other. .
Next, by pressing the first substrate 2 and the second substrate 3 against 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 convex portions 5B of the first metal bonding film 5 and the concave portions 6A and convex portions 6B of the second metal bonding film 6 are alternately combined and overlapped. , positioning is performed so as to form a substantially C-shaped joining allowance K in plan view.

The conditions for performing the diffusion bonding, that is, the conditions for sealing the sealing space C of the package 1 are not particularly limited. When the second metal bonding film 6 on the second substrate 3 side is {Au layer (first bonding layer 52 or second bonding layer 62)/Ta layer (first base layer 51 or second base layer 61)} For example, it is preferable to set the temperature condition in the range of 300 to 350° C. and the pressure 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 base layer 51 or second base layer 61)}. In some cases, for example, it is preferable to set the temperature condition to the range of 350 to 400° C. and the applied pressure to the range of 27 to 60 MPa.

Also, the sealing width (bonding width) when bonding the first substrate 2 and the second substrate 3, 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, when considering the improvement of the sealing airtightness, etc., the above sealing width is such that the first metal bonding film 5 and the second metal bonding film 6 are {Au layer (first bonding layer 52 or second bonding layer 62 )/Ta layer (first underlayer 51 or second underlayer 61)}, the thickness is preferably in the range of 0.15 to 0.30 mm, for example. 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 base layer 51 or second base layer 61)}. In some cases, the sealing width is preferably in the range of, for example, 0.03-0.1 mm.

Then, in the present embodiment, after the above step (6), as shown in FIG. The electrodes 8a and 8b are exposed, and then separated into individual chips.
The package 1 of the present embodiment can be manufactured by the above steps.
It should be noted that the steps described above can be changed in the order of steps or performed as the same steps as far as possible.

According to the method for manufacturing the package 1 of the present embodiment, in the step (3), the second metal bonding film 6 having the uneven shape is formed on the second substrate 3, and in the step (4), the first metal bonding film 6 is formed. After the first metal bonding film 5 having the uneven shape is formed on the substrate 2, the first metal bonding film 5 and the second metal bonding film 6 are alternately formed in the step (6). Metal diffusion bonding is performed so as to 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 bonding portion is distributed horizontally and vertically, and the stress is effective. effectively mitigated. As a result, when the first substrate 2 and the second substrate 3 are bonded at a high temperature, there is no need to manage the coefficient of thermal expansion of each film formed on the substrates, which eliminates the need for complicated process management. It is possible to prevent cracks or the like from occurring in the joints without adding any additional steps. Therefore, it is possible to manufacture inexpensive packages excellent in element characteristics with good productivity without requiring complicated process control.

Further, the manufacturing method of the present embodiment includes the steps (3) and (4) described above, in which the first metal bonding film 5 and the second metal bonding film 6 are formed at respective corresponding positions, and then the above steps are performed. (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 each other to achieve high sealing and airtightness. Package 1 is obtained. In addition, since the irregularities 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 electrical characteristics in the inside are also improved, resulting in excellent characteristics. Package 1 can be manufactured.

Further, according to the manufacturing method of the present embodiment, by forming the uneven shapes in the first metal bonding film 5 and the second metal bonding film 6 so as to be periodically arranged in the circumferential direction, the second When the first substrate 2 and the second substrate 3 are bonded, the stress at the bonding portion is distributed in the horizontal direction and the vertical direction, and the effect of relaxing the stress is stably obtained.

Further, according to the manufacturing method of the present embodiment, in the step (2), the convex body 31 is formed into a concavo-convex shape composed of concave portions and convex portions alternately arranged along the circumferential direction, similar to the second metal bonding film. In the case of forming such that the first substrate 2 and the second substrate 3 The effect of dispersing the stress in the joint in the horizontal direction and the vertical direction and relieving the stress is remarkably obtained.

Further, according to the manufacturing method of the present embodiment, in the steps (1) and (2), by using a silicon substrate excellent in workability by wet etching as the first substrate 2 and the second substrate 3, the step ( In 6), the internal stress is reduced when the first substrate 2 and the second substrate 3 are joined together, and the processing precision of the etching process is improved, so that the package 1 with even better device 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 bonding portion when the substrates are bonded and sealed is reduced. The infrared sensor can be manufactured as the package 1 which is relieved and can prevent cracks or the like from occurring in this junction, and which is low in cost and excellent in productivity and device characteristics.

[Effect]
As described above, according to the package 1 of the present embodiment, by providing the bonded body 50 composed of the first metal bonding film 5 and the second metal bonding film having the uneven shape as described above, the stress at the bonding portion is reduced. are distributed horizontally and vertically to effectively relieve stress. Thereby, even when the first substrate 2 and the second substrate 3 are bonded at a high temperature, cracks or the like can be prevented from occurring in the bonding portion.
Therefore, it is possible to realize the package 1 with a simple structure, low cost, and excellent productivity and device characteristics.

Further, according to the package manufacturing method of the present invention, the first metal bonding film 5 and the second metal bonding film 6 having the uneven shape as described above are formed in the steps (3) and (4) described above. However, in the step (6), the recesses and protrusions are overlapped and metal diffusion bonding is performed to join the first substrate 2 and the second substrate 3. Therefore, the stress at the joint is horizontal and horizontal. Distributed in the vertical direction, stress is effectively relieved. This eliminates the need to manage the coefficient of thermal expansion of each film formed on the substrate, eliminates the need for complicated process control, and prevents the occurrence of cracks or the like at the junction without adding a new process. can be prevented.
Therefore, it is possible to manufacture the package 1 inexpensively and with excellent device characteristics with high productivity without requiring complicated process control.

INDUSTRIAL APPLICABILITY As described above, the package of the present invention reduces the stress generated in the bonding portion when the substrates are bonded and sealed, and is low in cost and excellent in productivity and device characteristics. Therefore, it is very suitable for applications in electronic devices that require various types of highly reliable detection accuracy, such as mobile terminals, smart phones, sensor network devices, Internet of Things (IoT) technology, and the like.

REFERENCE SIGNS LIST 1 package 2 first substrate 2a upper surface 2b lower surface 22 device region 3 second substrate 3a lower surface 3b upper surface 31 convex body 32 cavity region 3A silicon substrate 4 element 50 bonded body 5 First metal bonding film 5A Concave portion 5B Convex portion 51 First base layer 52 First bonding layer 6 Second metal bonding film 6A Concave portion 6B Convex portion 61 Second base layer 62 Second bonding Layers 8a, 8b...Electrode C...Cavity (reduced pressure space)
L... dicing lines F1, F2... depth of recess (constriction depth)
L1, L2...Length of recess K...Joining allowance

Claims (9)

a first substrate;
an element provided on the upper surface side of the first substrate;
a frame-shaped projecting body bonded to the first substrate in plan view, and a plane a second substrate formed so as to be surrounded by the convex bodies in view and having a concave cavity region for securing a sealing space above the element;
A second metal bonding film provided in a frame shape in plan view at the tip of the convex body formed on the second substrate, and a position corresponding to the convex body formed on the second substrate. a bonded body formed by metal diffusion bonding with a first metal bonding film provided on the upper surface of the substrate in a frame shape in a plan view,
At least a part of the first metal bonding film and the second metal bonding film in a circumferential direction has an uneven shape composed of concave portions and convex portions alternately arranged along the circumferential direction in plan view, and the concave and convex portions of the first metal bonding film and the concave and convex portions of the second metal bonding film are superimposed and bonded together;
At least a portion of the convex body in the circumferential direction is composed of concave portions and convex portions alternately arranged along the circumferential direction so as to correspond to the uneven shape provided on the second metal bonding film. A package characterized by having an uneven shape . 2. The package according to claim 1, wherein the uneven shapes of the first metal bonding film and the second metal bonding film are periodically arranged in the circumferential direction. 3. The package according to claim 1, wherein said first substrate and said second substrate are made of silicon substrates. 4. The package according to any one of claims 1 to 3 , wherein the element is an infrared detection element, and the second substrate is capable of transmitting infrared rays. at least,
a step (1) of etching the surface of the substrate material to form a concave device region for housing the element to obtain a first substrate;
By etching the surface of the substrate material, a frame-shaped projecting body in plan view and a recessed cavity surrounded by the projecting body in plan view for securing a sealing space above the element are formed. a step (2) of forming a region to obtain a second substrate;
At the tip of the convex body formed on the second substrate, at least a part in the circumferential direction, which has a frame shape in plan view, is composed of recesses and protrusions alternately arranged along the circumferential direction in plan view. a step (3) of forming a second metal bonding film having an uneven shape;
On the first substrate, at a position corresponding to the convex body when the first substrate and the second substrate are superimposed, a frame shape in plan view and at least a part in the circumferential direction in plan view. a step (4) of forming a first metal bonding film having an uneven shape composed of recesses and protrusions alternately arranged along the circumferential direction;
a step (5) of arranging the element in the device region formed on the first substrate;
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 bonded together. By pressurizing each other and performing metal diffusion bonding, the concave portions and convex portions of the first metal bonding film and the concave portions and convex portions of the second metal bonding film are superimposed and bonded, and the first substrate and the second substrate are bonded together. a step (6) of bonding the substrate;
A method of manufacturing a package, comprising: The step (3) and the step (4) are characterized in that the uneven shapes provided on the first metal bonding film or the second metal bonding film are formed so as to be arranged periodically in the circumferential direction. The manufacturing method of the package according to claim 5 . The step (2) further includes forming the convex body so that at least a portion thereof in the circumferential direction has an uneven shape composed of concave portions and convex portions alternately arranged along the circumferential direction,
In the step (3), at least a portion of the second metal bonding film in the circumferential direction is formed from concave portions and convex portions alternately arranged along the circumferential direction so as to cover the tips of the convex portions. 7. The method of manufacturing a package according to claim 5 , wherein the package is formed to have a concave and convex shape. 8. The method of manufacturing a package according to claim 5 , wherein in said step ( 1 ) and said step (2), a silicon substrate is used as said substrate material. 9. The method according to any one of claims 5 to 8 , wherein in the step (5), an infrared detection element is arranged as the element in the device region formed on the first substrate. How the package is made.

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