JP2015220444A - Package and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent visible light and infrared light from entering from a mounting substrate side into an element of an element substrate in a package in which the element substrate including the element formed therein is mounted on a mounting substrate.SOLUTION: A package 1 includes: an element substrate 5 in which an element 23 is formed; a mounting substrate 3 on which the element substrate 5 is mounted; and a cover substrate 7 joined to the element substrate 5. A light shield film 11, which is used to shield visible light and infrared light entering from the mounting substrate 3 side to the element 23 and made of a metal material, is formed on a mounting surface 3a of the mounting substrate 3.

Description

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

  For example, there is a package having an element made of a semiconductor element or a MEMS (Micro Electro Mechanical Systems) element. When manufacturing such a package, in order to reduce the packaging cost, a wafer level package in which an element substrate on which an element is formed and a mounting substrate on which the element substrate is mounted are joined at a wafer level and then separated into individual pieces. May be considered. Examples of mounting substrates used for wafer level packaging include ceramic materials, glass materials, and silicon materials.

  For example, the mounting substrate includes a metal embedded electrode, and has a structure in which the terminal of the element substrate can be taken out to an external terminal and mounted. In addition, some elements may be vacuum-tight or hermetically sealed (see, for example, Patent Document 1).

  For example, when a mounting substrate made of a material that transmits visible light or infrared light such as glass material or silicon material is used, visible light or infrared light incident on the element of the element substrate from the mounting substrate side is shielded. It may be preferable.

  An object of the present invention is to prevent visible light and infrared light from being incident on an element of an element substrate from the mounting substrate side in a package in which the element substrate on which the element is formed is mounted on the mounting substrate. To do.

  A package according to the present invention includes an element substrate on which an element is formed, a mounting substrate on which the element substrate is mounted, and visible light and infrared light incident on the element from the mounting substrate side. And a light shielding film made of a metal material.

  The package of the present invention can prevent visible light and infrared light from entering the element of the element substrate from the mounting substrate side.

It is a schematic sectional drawing for demonstrating one Example of a package. It is a schematic plan view for demonstrating arrangement | positioning of the film | membrane in the mounting surface of the mounting substrate which comprises a part of the Example. It is a schematic sectional drawing for demonstrating the laminated structure of the metal film which comprises a part of the Example. It is a schematic sectional drawing for demonstrating one Example of the manufacturing method of a package. FIG. 6 is a schematic cross sectional view for illustrating a subsequent step in the example. It is a schematic sectional drawing for demonstrating the other Example of a package. It is a schematic sectional drawing for demonstrating the further another Example of a package. It is a schematic sectional drawing for demonstrating the further another Example of a package. It is a schematic sectional drawing for demonstrating the further another Example of a package. It is a schematic sectional drawing for demonstrating the further another Example of a package. It is a schematic sectional drawing for demonstrating the further another Example of a package.

  The package of the present invention may further include, for example, a cover substrate disposed on the side opposite to the mounting substrate with respect to the element substrate. By disposing the cover substrate, the element substrate can be protected, or the space between the mounting substrate, the element substrate, and the cover substrate can be in a vacuum state or a sealed state. However, the package of the present invention includes a configuration in which the cover substrate is not provided.

  In the package of the present invention, an example in which the element is an optical sensor can be given. However, in the present invention, the element formed on the element substrate is not limited to the optical sensor. The element may be another element such as a semiconductor element such as a semiconductor integrated circuit, a light emitting element, or a MEMS element, and is not particularly limited.

  In the package of the present invention, when the cover substrate is disposed and the element is an optical sensor, the cover substrate preferably has light transmittance. Here, the cover substrate only needs to transmit at least light having a wavelength to be detected by the optical sensor. In the present invention, the cover substrate is not limited to one having optical transparency.

  In the package of the present invention, the light shielding film may be a mounting surface side light shielding film formed on the mounting surface of the element substrate of the mounting substrate, or a back surface opposite to the mounting surface of the mounting substrate. An example may be given in which the formed rear surface side light shielding film or both the mounting surface side light shielding film and the rear surface side light shielding film are provided. However, in the package of the present invention, the light shielding film is not limited to the mounting surface light shielding film and the back surface light shielding film. In the package of the present invention, the light shielding film may be made of a metal material and may be configured to shield visible light and infrared light incident on the element from the mounting substrate side. For example, the light shielding film may be disposed on the element substrate or may be disposed inside the mounting substrate.

  In the package of the present invention, the element substrate includes an external connection contact metal film on a surface facing the mounting substrate, and the mounting substrate has the external connection contact metal film on the mounting surface. The mounting surface side contact metal film is disposed at a position corresponding to the contact surface, and the corresponding external connection contact metal film and the mounting surface side contact metal film are electrically connected via an electrical contact bonding material. An example is given in which at least the mounting surface side light shielding film is provided as the light shielding film, and the mounting surface side light shielding film and the mounting surface side contact metal film are formed of the same material. be able to. In this aspect of the package of the present invention, since the mounting surface side light shielding film and the mounting surface side contact metal film are formed of the same material, the mounting surface side light shielding film can be formed without increasing the manufacturing process. Can do.

  Furthermore, this aspect of the package of the present invention is the mounting surface side rewiring film formed simultaneously on the mounting surface of the mounting substrate with the same material as the mounting surface side light shielding film and the mounting surface side contact metal film. The mounting surface side redistribution film is electrically connected to the mounting surface side contact metal film, and is drawn from a position where the mounting surface side contact metal film is formed to a position different from the formation position. Examples can be given. According to this aspect of the package of the present invention, the potential of the external connection contact metal film of the element substrate is drawn out to an arbitrary position via the electrical contact bonding material, the mounting surface side contact metal film, and the mounting surface side rewiring film. be able to.

  Further, in this aspect of the package of the present invention, the mounting substrate includes an embedded electrode that is electrically connected from the back surface opposite to the mounting surface to the mounting surface, and the embedded electrode is An example of being electrically connected to the mounting surface side contact metal film through the mounting surface side rewiring film can be given. In this aspect of the package of the present invention, the potential of the external connection contact metal film of the element substrate is mounted via the electrical contact bonding material, the mounting surface side contact metal film, the mounting surface side rewiring film, and the embedded electrode. It can be pulled out to any position on the back side of the substrate. Thereby, for example, with respect to the arrangement of the mounting terminals provided on the back side of the mounting substrate, the mounting pitch can be expanded and the degree of freedom to change the layout is improved.

  In the package of the present invention, the element substrate and the mounting substrate are bonded by anodic bonding, silicon-silicon bonding, or bonding material in a bonding region provided at a position not overlapping the element arrangement region. Can be mentioned. Thereby, the element substrate and the mounting substrate are firmly bonded. Further, when the element substrate and the mounting substrate are bonded by anodic bonding, a bonding material for bonding the element substrate and the mounting substrate is unnecessary, and the manufacturing cost is reduced.

  Furthermore, in this aspect of the package of the present invention, an example in which the bonding material is a non-conductive bonding material can be given. Examples of the non-conductive bonding material include a frit glass bonding agent and a polyimide bonding agent. However, the non-conductive bonding material is not limited to these bonding agents. By using a non-conductive bonding material as the bonding material, the manufacturing cost is reduced as compared with the case where a conductive bonding material more expensive than the non-conductive bonding material is used. In the package of the present invention, the bonding material may be a conductive bonding material.

  In the package according to the present invention, the element substrate is a bonding region provided at a position that does not overlap the element arrangement region, and the element substrate side bonding metal made of a metal material disposed on a surface facing the mounting substrate. The mounting substrate includes a mounting substrate side bonding metal film made of a metal material disposed on the mounting surface in the bonding region, and the element substrate side bonding metal film and the mounting. The substrate-side bonding metal film is bonded through a bonding material, and at least the mounting surface-side light-shielding film is provided as the light-shielding film. The mounting surface-side light-shielding film and the mounting substrate-side bonding metal An example in which the film is formed of the same material can be given. In this aspect of the package of the present invention, since the mounting surface side light shielding film and the mounting substrate side bonding metal film are formed of the same material, the mounting surface side light shielding film is formed without increasing the number of manufacturing steps. be able to.

  Furthermore, in this aspect of the package of the present invention, an example in which the bonding material is a non-conductive bonding material can be given. The effect of using a non-conductive bonding material as the bonding material is the same as described above. In this aspect of the package of the present invention, the bonding material may be a conductive bonding material.

  In the package of the present invention, the element substrate includes a metal film for contact for external connection on a surface facing the mounting substrate, and the mounting substrate is external to the mounting surface of the mounting substrate. A mounting surface side contact metal film disposed at a position corresponding to the connection contact metal film, a buried electrode electrically connected from the back surface opposite to the mounting surface to the mounting surface, and the back surface A contact-side metal film for external connection, and a contact film corresponding to the contact-side metal film for external connection, which are electrically connected to the mounting-surface-side contact metal film via the embedded electrode. The metal film for electrical use is electrically connected via an electrical contact bonding material, and at least the back-side light-shielding film is provided as the light-shielding film, and the back-side light-shielding film and the back-side contact metal film are the same Formed of material Can example it is intended. In this aspect of the package of the present invention, the back-side light-shielding film and the back-side contact metal film are formed of the same material, so that the back-side light-shielding film can be formed without increasing the number of manufacturing steps.

  Furthermore, in this aspect of the package of the present invention, the back surface of the mounting substrate is provided with a back surface side rewiring film formed simultaneously with the same material as the back surface side light shielding film and the back surface side contact metal film, An example in which the back-side rewiring film is electrically connected to the back-side contact metal film and is drawn from the formation position of the back-side contact metal film to a position different from the formation position. Can do. In this aspect of the package of the present invention, the potential of the metal film for contact for external connection of the element substrate is set for mounting via the electrical contact bonding material, the metal film for contact on the mounting surface side, the buried electrode, and the rewiring film on the back surface side. It can be pulled out to any position on the back side of the substrate.

  Further, in the package of the present invention, the light shielding film may be an example having a laminated structure in which a Ti layer, a Ni layer, and an Au layer are laminated in order from the lower layer side. However, in the package of the present invention, the configuration of the light shielding film is not limited to this. In the package of the present invention, the light shielding film may be made of a metal material and may be configured to shield visible light and infrared light incident on the element from the mounting substrate side.

A manufacturing method of a package according to the present invention is a manufacturing method of a package including an element substrate on which an element is formed and a mounting substrate on which the element substrate is mounted on a mounting surface. A light-shielding film forming step of forming a light-shielding film made of a metal material disposed at a position overlapping the element arrangement region of the element substrate; and a mounting step of mounting the element substrate on the mounting surface of the mounting substrate. It is characterized by including.
The package manufacturing method of the present invention can form a light-shielding film for preventing visible light and infrared light from entering the device from the mounting substrate side.

  As a first aspect of the package manufacturing method of the present invention, the light shielding film forming step includes mounting a metal material on the mounting surface of the mounting substrate at a position corresponding to the external connection terminal of the element substrate. A mounting surface side contact metal film forming step of simultaneously forming the surface side contact metal film and the mounting surface side light shielding film as the light shielding film with the same metal material, wherein the mounting step is for the mounting surface side contact An example in which the metal film and the external connection terminal are electrically connected via an electrical contact bonding material and the element substrate is mounted on the mounting surface of the mounting substrate can be given.

  In the first aspect of the manufacturing method of the package of the present invention, in the aspect requiring the mounting surface side contact metal film, the mounting surface side light shielding film as the light shielding film is formed without increasing the manufacturing process. can do.

  As a second aspect of the manufacturing method of the package of the present invention, the package is made of a metal material disposed in a bonding region provided on a surface of the element substrate facing the mounting substrate so as not to overlap with the element arrangement region. It further includes an element substrate side bonding metal film forming step of forming an element substrate side bonding metal film, wherein the light shielding film forming step is performed from a metal material disposed in the bonding region on the mounting surface of the mounting substrate. A mounting substrate-side bonding metal film forming step of simultaneously forming the mounting substrate-side bonding metal film and the mounting surface-side light-shielding film as the light-shielding film with the same metal material, and the mounting step includes the element An example of mounting the element substrate on the mounting surface of the mounting substrate by bonding the substrate-side bonding metal film and the mounting substrate-side bonding metal film via a bonding material can be given.

  In the second aspect of the manufacturing method of the package of the present invention, in the aspect requiring the mounting substrate side bonding metal film, the mounting surface side light shielding film as the light shielding film is used without increasing the manufacturing process. Can be formed.

  As a third aspect of the package manufacturing method of the present invention, the light shielding film forming step is electrically conducted from the back surface to the mounting surface on the back surface opposite to the mounting surface of the mounting substrate. A metal film for a back side contact that simultaneously forms a metal film for a back side contact made of a metal material arranged so as to be electrically connected to the embedded electrode, and a back side light shielding film as the light shielding film with the same metal material An example including a forming step can be given.

  In the third aspect of the manufacturing method of the package of the present invention, in the aspect requiring the backside contact metal film, the backside light shielding film as the light shielding film is formed without increasing the number of manufacturing steps. Can do.

  In the third aspect of the manufacturing method of the package of the present invention, the metal film forming step for the back contact, which forms the metal film for the back contact and the light shielding film on the back surface, is performed before the bonding step. Or may be performed later.

  Further, when the third aspect is combined with the first aspect, the metal film forming step for the back side contact in the third aspect is based on the metal film forming step for the mounting surface side contact in the first aspect. It may be performed before or after. When the back surface contact metal film forming step is performed before the mounting surface contact metal film forming step, the back contact metal film forming step is necessarily prior to the bonding step. Will be done.

  Further, when the third aspect is combined with the second aspect, the metal film forming process for the back side contact in the third aspect is based on the metal film forming process for mounting substrate side bonding in the second aspect. It may be performed before or after. When the back side contact metal film forming step is performed before the mounting substrate side joining metal film forming step, the back side contact metal film forming step is necessarily more than the joining step. Will be done before.

  In the package manufacturing method of the present invention, an element wafer on which a plurality of the element substrates are arranged and a mounting wafer on which a plurality of the mounting substrates are arranged corresponding to the plurality of the element substrates are used. In the mounting step, the mounting substrate and the element substrate are aligned, the element wafer and the mounting wafer are bonded, and then the mounting substrate and the element substrate on which the light shielding film is formed are combined. An example that further includes an individualization step of dividing into individual pieces and cutting out the package can be given. In this aspect of the manufacturing method of the package of the present invention, since the element substrate and the mounting substrate can be simultaneously bonded to a plurality of packages, the manufacturing cost can be reduced.

  The package manufacturing method of the present invention can include an example further including a cover substrate bonding step of bonding a cover substrate to a surface of the element substrate opposite to the mounting substrate. By disposing the cover substrate, the element substrate can be protected, or the space between the mounting substrate, the element substrate, and the cover substrate can be in a vacuum state or a sealed state.

  Further, in the package manufacturing method of the present invention, in the aspect including the cover substrate bonding step, an example in which the element is an optical sensor and the cover substrate has optical transparency can be given.

  Further, the aspect including the cover substrate bonding step of the package manufacturing method of the present invention includes an element wafer in which the plurality of element substrates are arranged, and a plurality of the mounting substrates corresponding to the plurality of element substrates. Are mounted in the mounting step, and a mounting wafer in which the plurality of cover substrates are disposed in correspondence with the plurality of element substrates. The element wafer and the mounting wafer are bonded to each other, and the element substrate and the cover substrate are aligned to bond the element wafer and the cover wafer in the cover substrate bonding step. After that, an example can be given that further includes a singulation step of separating the set of the mounting substrate on which the light-shielding film is formed, the element substrate, and the cover substrate into pieces and cutting out the package. . In this aspect of the package manufacturing method of the present invention, the element substrate and the mounting substrate can be simultaneously bonded to a plurality of packages, and the element substrate and the cover substrate can be simultaneously bonded. Therefore, the manufacturing cost can be reduced.

  Moreover, the manufacturing method of the package of this invention can mention the example which forms the formation of the said light shielding film by the lift-off method or the etching method. However, in the package manufacturing method of the present invention, the method for forming the light shielding film is not limited to the lift-off method and the etching method.

  In the prior art, visible light or infrared light is incident on the element from the mounting substrate side by providing a light-shielding wall with resin or using a highly light-shielding material such as a ceramic substrate as the mounting substrate. It was preventing that.

  On the other hand, the present invention prevents visible light and infrared light from entering the element from the mounting substrate side by the light shielding film even if an inexpensive silicon substrate or glass substrate is used as the mounting substrate. Can do. In the present invention, an inexpensive substrate that transmits visible light or infrared light is used as the mounting substrate, thereby reducing the manufacturing cost of the package.

  Further, in the present invention, if the light shielding film is formed of the same material as the other metal film formed on the mounting substrate at the same time, the present invention includes a process for forming the light shielding film. Compared with the case where it is necessary, the manufacturing process can be simplified and the manufacturing cost of the package can be reduced.

Embodiments of the present invention will be described below with reference to the drawings.
For example, when performing a wafer level packaging of an element substrate using a mounting substrate such as a silicon material or a glass material, when performing metal-based bonding between the element substrate and the mounting substrate, the element substrate and the mounting substrate A bonding metal film made of a metal material is formed on each of these.

Also, in order to ensure electrical connection between the external connection contact metal film formed on the element substrate and the semiconductor circuit and the mounting substrate, a contact metal film made of a conductive material is formed on the mounting substrate. Be filmed.
Further, when performing vacuum wafer level packaging, a gas absorbing material (getter) is formed or applied.

  Furthermore, in order to use a material that transmits visible light or infrared light, such as silicon or glass, as the mounting substrate, it is necessary to block external light such as visible light and infrared light from the mounting substrate side, It is also necessary to form a light shielding film.

  The embodiment described below reduces costs such as the number of film forming steps and the number of masks by combining the film forming material and the process and simultaneously forming the light shielding film with other films while ensuring the necessary functions. Thus, a light-shielding package from the mounting substrate side is realized. Furthermore, the embodiments described below realize high vacuum and airtight packaging at the wafer level.

  FIG. 1 is a schematic cross-sectional view for explaining an embodiment of a package. FIG. 2 is a schematic plan view for explaining the film arrangement on the mounting surface of the mounting substrate constituting a part of this embodiment. FIG. 3 is a schematic cross-sectional view for explaining a laminated structure of metal films constituting a part of this embodiment. This embodiment will be described with reference to FIGS.

The package 1 includes a mounting substrate 3, an element substrate 5, and a cover substrate 7.
For example, the mounting substrate 3 transmits infrared light. The mounting substrate 3 is, for example, a glass substrate or a silicon substrate.

  The mounting substrate 3 includes a buried electrode 9 that is electrically connected from the mounting surface 3a on which the element substrate 5 is mounted to the back surface 3b. The embedded electrode 9 is constituted by, for example, a through electrode embedded in a through hole formed from the mounting surface 3a to the back surface 3b.

  On the mounting surface 3 a of the mounting substrate 3, the mounting surface side light shielding film 11, the mounting surface side contact metal film 13, the mounting surface side rewiring film 15, the gas absorbing material 17, and the mounting surface side bonding metal film. 19 is formed. A back contact metal film 21 is formed on the back surface 3 b of the mounting substrate 3.

  The mounting surface side light shielding film 11 is disposed at a position that overlaps at least the arrangement region of the element 23 of the element substrate 5. The mounting surface side light shielding film 11 has a function of shielding visible light and infrared light incident on the element 23 from the mounting substrate 3 side.

  The mounting surface side contact metal film 13 is disposed at a position corresponding to the external connection contact metal film 29 of the element substrate 5.

  The mounting surface side rewiring film 15 is electrically connected to the mounting surface side contact metal film 13. The mounting surface side rewiring film 15 is drawn from a position where the mounting surface side contact metal film 13 is formed to a position different from the formation position. The mounting surface side rewiring film 15 is electrically connected to the corresponding embedded electrode 9. The embedded electrode 9 is electrically connected to the corresponding mounting surface side contact metal film 13 via the mounting surface side rewiring film 15.

  The gas absorber 17 is for absorbing gas in the internal space 27 of the package 1. The gas absorbing material 17 is, for example, a titanium metal film or a cobalt metal film.

  The mounting surface side bonding metal film 19 is made of a metal material. The mounting surface side bonding metal film 19 is disposed in a bonding region provided at a position that does not overlap with the region where the element 23 of the element substrate 5 is disposed. For example, as shown in FIG. 2, the mounting surface side light-shielding film 11, the mounting surface side contact metal film 13, the mounting surface side rewiring film 15, and the gas absorbing material 17 are arranged on the mounting surface side bonding metal film 19. It is arranged in the shape of a frame so as to surround the area that has been formed.

  The back contact metal film 21 formed on the back surface 3 b of the mounting substrate 3 is electrically connected to the corresponding embedded electrode 9. The back-side contact metal film 21 is electrically connected to the mounting surface-side contact metal film 13 via the embedded electrode 9 and the mounting surface-side rewiring film 15.

  The mounting surface side light shielding film 11, the mounting surface side contact metal film 13, and the mounting surface side redistribution film 15 are formed of the same metal material at the same time.

  As shown in FIG. 3, the mounting surface side light shielding film 11, the mounting surface side contact metal film 13, and the mounting surface side rewiring film 15 are, for example, a titanium (Ti) layer and nickel (Ni) in order from the lower layer side. And a stacked structure in which a gold (Au) layer is stacked. For example, the thickness of the titanium layer is 100 nm (nanometers), the thickness of the nickel layer is 100 nm, and the thickness of the gold layer is 200 nm. The titanium layer functions as an adhesion layer. The nickel layer functions as an intermediate layer. The gold layer functions as a bonding layer. The configurations of the mounting surface side light shielding film 11, the mounting surface side contact metal film 13, and the mounting surface side redistribution film 15 are not limited to the above laminated structure. For example, the metal material may be gold, silver, tungsten, or the like.

  The mounting surface side bonding metal film 19 may be formed simultaneously with the same laminated structure as the mounting surface side light shielding film 11, the mounting surface side contact metal film 13 and the mounting surface side rewiring film 15. However, the structure may be different from those of these films.

  The back contact metal film 21 has the same laminated structure as the mounting surface light shielding film 11, the mounting surface contact metal film 13, and the mounting surface rewiring film 15. However, the back surface side contact metal film 21 is formed at a time different from the formation time of the mounting surface side light shielding film 11, the mounting surface side contact metal film 13 and the mounting surface side rewiring film 15.

The element substrate 5 includes an element 23. The element substrate 5 is a silicon substrate, for example.
The element 23 is an infrared sensor formed by, for example, MEMS technology. In the arrangement region of the element 23, for example, a semiconductor circuit or the like is formed in addition to the infrared sensor. The element substrate 5 includes various films for device formation. In FIG. 1, the structure of the element substrate 5 is illustrated in a simplified manner.

  On the element substrate 5, an external connection terminal 25, an external connection contact metal film 29, and element substrate-side bonding metal films 31 and 33 are also formed. The external connection terminal 25, the external connection contact metal film 29, and the element substrate side bonding metal film 31 are formed on the surface of the element substrate 5 facing the mounting substrate 3. The element substrate side bonding metal film 33 is formed on the surface of the element substrate 5 facing the cover substrate 7.

The external connection terminal 25 is, for example, an aluminum pad.
The external connection contact metal film 29 is electrically connected to the external connection terminal 25. In this embodiment, the external connection contact metal film 29 is disposed at a position overlapping the external connection terminal 25. The external connection contact metal film 29 may be provided to extend from a position overlapping the external connection terminal 25 to an arbitrary position and function as a rewiring film. The external connection contact metal film 29 is made of a metal material. For example, the external connection contact metal film 29 has the same laminated structure as the mounting surface side light shielding film 11, the mounting surface side contact metal film 13, and the mounting surface side rewiring film 15.

  The element substrate side bonding metal films 31 and 33 are made of a metal material. The element substrate side bonding metal films 31 and 33 are arranged in a bonding region provided at a position not overlapping with the arrangement region of the element 23 of the element substrate 5. The element substrate side bonding metal film 31 is arranged in a frame shape corresponding to the formation position of the mounting surface side bonding metal film 19. The element substrate side bonding metal film 33 is also arranged in a frame shape corresponding to the position where the element substrate side bonding metal film 31 is formed, for example.

  The element substrate side bonding metal film 31 may be formed of the same material as that of the external connection contact metal film 29 at the same time, or formed separately from the external connection contact metal film 29. It may be.

  The cover substrate 7 is made of, for example, a material that transmits at least infrared light. The cover substrate 7 is made of, for example, silicon, glass, germanium, or the like. The cover substrate 7 may have a lens function.

  A cover substrate-side bonding metal film 35 is formed on the surface of the cover substrate 7 facing the element substrate 5. The cover substrate-side bonding metal film 35 is made of a metal material. The cover substrate-side bonding metal film 35 is arranged in a frame shape corresponding to the position where the element substrate-side bonding metal film 33 is formed.

The mounting substrate 3 and the element substrate 5 are bonded together by an electrical contact bonding material 37 and a bonding material 39.
The element substrate 5 and the cover substrate 7 are bonded by a bonding material 41.
The internal space 27 of the package 1 is in a high vacuum state or a sealed state.

  The electrical contact bonding material 37 bonds the mounting surface side contact metal film 13 of the mounting substrate 3 and the external connection contact metal film 29 of the element substrate 5. The electrical contact bonding material 37 is a conductive material, such as gold, silver, or solder.

The bonding material 39 bonds the mounting surface side bonding metal film 19 of the mounting substrate 3 and the element substrate side bonding metal film 31 of the element substrate 5 together.
The bonding material 41 bonds the element substrate-side bonding metal film 33 of the element substrate 5 and the cover substrate-side bonding metal film 35 of the cover substrate 7.

  The bonding materials 39 and 41 are, for example, a metal brazing material such as a gold-tin alloy (gold 80%, tin 20%), a frit glass bonding agent, a polyimide bonding agent, or the like. Unlike the electrical contact bonding material 37, the bonding materials 39 and 41 do not require conductivity.

  A mounting terminal 43 is formed on the back contact metal film 21 formed on the back surface 3 b of the mounting substrate 3. The mounting terminal 43 is a terminal used when the packaged package 1 is mounted on another substrate or the like. In general, for example, solder bumps, solder balls, and gold bumps are used as the mounting terminals 43.

  For example, when the back side contact metal film 21 includes a gold layer having a thickness of 200 nm as the uppermost layer of the structure, the nickel plating layer and the gold plating layer are formed on the surface of the back side contact metal film 21 by electroless plating. A laminated structure (not shown) is formed. Mounting terminals 43 are arranged on the plated layer.

  The light receiving input 45 enters the element 23 of the element substrate 5 through the cover substrate 7. The light receiving input 45 is, for example, visible light or infrared light.

  The light beam 47 to be shielded that is irradiated to the mounting substrate 3 side of the package 1 is transmitted through the mounting substrate 3 but is shielded by the mounting surface side light shielding film 11, and is prevented from entering the element 23 of the element substrate 5. The light beam 47 to be shielded is, for example, visible light or infrared light.

  Thus, the package 1 can prevent visible light and infrared light from entering the element 23 of the element substrate 5 from the mounting substrate 3 side.

  4 and 5 are schematic cross-sectional views for explaining an embodiment of a package manufacturing method. This embodiment is an example of a manufacturing method for manufacturing the package 1 shown in FIG. The numbers in parentheses in FIGS. 4 and 5 correspond to the numbers in parentheses for each process described below.

  Step (1): A mounting substrate 3 on which a buried electrode 9 that is electrically conductive from the mounting surface 3a to the back surface 3b is formed is prepared.

  Step (2): The mounting surface side light-shielding film 11, the mounting surface side contact metal film 13, and the mounting surface side rewiring film 15 are simultaneously formed of the same metal material on the mounting surface 3a of the mounting substrate 3. Further, the gas absorbing material 17 is formed on the mounting surface 3a. Further, the mounting surface side bonding metal film 19 is formed on the mounting surface 3a. Further, a back contact metal film 21 is formed on the back surface 3 b of the mounting substrate 3. Each film is formed by, for example, a lift-off method or an etching method.

  Step (3): An electrical contact bonding material 37 is formed on the mounting surface side contact metal film 13 of the mounting surface 3a of the mounting substrate 3.

  Step (4): A bonding material 39 is formed on the mounting surface side bonding metal film 19 of the mounting surface 3a of the mounting substrate 3.

  Step (5): The element substrate 5 on which the element 23 and the external connection terminal 25 are formed is prepared. An external connection contact metal film 29 is formed on the external connection terminal 25. Further, the element substrate side bonding metal film 31 is formed on the same surface as the formation surface of the external connection contact metal film 29. The element substrate side bonding metal film 31 may be formed simultaneously with the same metal material as the external connection contact metal film 29, or may be formed separately from the external connection contact metal film 29. It may be.

  Step (6): The mounting substrate 3 and the element substrate 5 are bonded. Specifically, the mounting surface side contact metal film 13 of the mounting substrate 3 and the external connection contact metal film 29 of the element substrate 5 are bonded by the electric contact bonding material 37, and the mounting surface side bonding of the mounting substrate 3 is performed. The metal film 19 for bonding and the element substrate-side bonding metal film 31 of the element substrate 5 are bonded together by a bonding material 39.

  Step (7): A cover substrate 7 is prepared. A cover substrate-side bonding metal film 35 is formed on the cover substrate 7.

  Step (8): A bonding material 41 is formed on the cover substrate-side bonding metal film 35 of the cover substrate 7.

  Step (9): The element substrate side bonding metal film 33 is formed on the surface of the element substrate 5 opposite to the mounting substrate 3 with respect to the mounting substrate 3 and the element substrate 5 bonded in the above step (6). Form.

  Step (10): The cover substrate 7 is bonded to the element substrate 5 with respect to the mounted substrate 3 and element substrate 5 that have been bonded. Specifically, the element substrate side bonding metal film 33 of the element substrate 5 and the cover substrate side bonding metal film 35 of the cover substrate 7 are bonded by the bonding material 41. The bonding process is performed in a vacuum or in an environment where airtight sealing is possible. The internal space 27 of the package 1 is in a high vacuum state or a hermetically sealed state.

  Step (11): A mounting terminal 43 is formed on the back contact metal film 21 on the back surface 3b of the mounting substrate 3 with respect to the mounted mounting substrate 3, element substrate 5, and cover substrate 7. . Thereby, the formation process of the package 1 is completed.

  In this embodiment, since the mounting surface side light shielding film 11 is formed of the same material as the mounting surface side contact metal film 13 at the same time, the mounting surface side light shielding film 11 can be formed without increasing the number of manufacturing steps.

  In this embodiment, the manufacturing process of one package 1 has been described, but a plurality of packages 1 may be formed simultaneously at the wafer level. A mounting wafer on which a plurality of mounting substrates 3 are formed, an element wafer on which a plurality of element substrates 5 are formed, and a cover wafer on which a plurality of cover substrates 7 are formed are used. The mounting wafer, the element wafer, and the cover wafer are bonded at the wafer level in the same manner as in the steps (1) to (11), and a plurality of packages 1 are formed simultaneously. Thereafter, the bonded wafer is separated into pieces and the package 1 is cut out. Since the mounting substrate 3 and the element substrate 5 and the element substrate 5 and the cover substrate 7 can be bonded to the plurality of packages 1 at the same time, the manufacturing cost can be reduced.

  FIG. 6 is a schematic cross-sectional view for explaining another embodiment of the package. In FIG. 6, parts having the same functions as those in FIG.

  In this embodiment, the mounting surface side light shielding film 11 is formed of the same metal material as the mounting surface side bonding metal film 19 at the same time. The mounting surface side light-shielding film 11 includes the mask pattern for forming the mounting surface side contact metal film 13 and the mounting surface side bonding metal film 19 in the step (2) described with reference to FIG. It can be formed by changing the pattern of the mask for forming each.

  Since the mounting surface side light shielding film 11 is formed of the same metal material as the mounting surface side bonding metal film 19 at the same time, the mounting surface side light shielding film 11 can be formed without increasing the number of manufacturing steps.

  FIG. 7 is a schematic cross-sectional view for explaining still another embodiment of the package. In FIG. 7, parts having the same functions as those in FIG.

  In this embodiment, the mounting surface side light shielding film 11, the mounting surface side contact metal film 13, the mounting surface side rewiring film 15, and the mounting surface side bonding metal film 19 are formed of the same metal material at the same time. . Such a structure is a mask for forming the mounting surface side light shielding film 11, the mounting surface side contact metal film 13, and the mounting surface side rewiring film 15 in the step (2) described with reference to FIG. It can be formed by changing the pattern.

  Since the mounting surface side light shielding film 11 is simultaneously formed of the same metal material as the mounting surface side contact metal film 13, the mounting surface side rewiring film 15, and the mounting surface side bonding metal film 19, also in this embodiment, The mounting surface side light shielding film 11 can be formed without increasing the number of manufacturing steps.

  FIG. 8 is a schematic cross-sectional view for explaining still another embodiment of the package. In FIG. 8, parts having the same functions as those in FIG.

  In this embodiment, the mounting surface side light shielding film 11 is not provided, and the back surface side light shielding film 49 is disposed on the back surface 3 b of the mounting substrate 3. The back side light shielding film 49 is disposed at a position overlapping the element 23 of the element substrate 5. The back side light shielding film 49 is formed simultaneously with the same metal material as the back side contact metal film 21.

  Such a configuration includes a mask pattern for forming the mounting surface side light shielding film 11 and a mask for forming the metal film 21 for the back side contact in the step (2) described with reference to FIG. It can be formed by changing the pattern.

  Since the back side light shielding film 49 is formed of the same metal material as that of the back side contact metal film 21, the back side light shielding film 49 can be formed without increasing the number of manufacturing steps.

  Since the back-side light-shielding film 49 is arranged at a position overlapping the element 23 of the element substrate 5, the light ray 47 to be shielded from being irradiated on the mounting substrate 3 side of the package 1 is shielded by the back-side light-shielding film 49 Incidence of the substrate 5 on the element 23 is blocked. Thus, the package 1 of this embodiment can prevent visible light and infrared light from entering the element 23 of the element substrate 5 from the mounting substrate 3 side.

  In addition, the arrangement of the back surface side light shielding film 49 is added to the configuration of the package 1 shown in FIG. 1, FIG. 6, or FIG. Both the film 11 and the back-side light-shielding film 49 may be provided.

  FIG. 9 is a schematic cross-sectional view for explaining still another embodiment of the package. 9, parts having the same functions as those in FIGS. 1 and 8 are denoted by the same reference numerals.

  In this embodiment, as compared with the package 1 shown in FIG. 8, a back surface side rewiring film 51 is further arranged on the back surface 3 b of the mounting substrate 3. The back-side rewiring film 51 is electrically connected to the back-side contact metal film 21 and is drawn from a position where the back-side contact metal film 21 is formed to a position different from the formation position. A mounting terminal 43 is formed on the back-side rewiring film 51.

  The back-side rewiring film 51 is formed of the same metal material as the back-side contact metal film 21 and the back-side light shielding film 49 at the same time. Such a configuration includes a mask pattern for forming the mounting surface side light shielding film 11 and a mask for forming the metal film 21 for the back side contact in the step (2) described with reference to FIG. It can be formed by changing the pattern.

  In this embodiment, for example, the mounting pitch of the mounting terminals 43 can be expanded with respect to the arrangement of the embedded electrodes 9, and the degree of freedom of changing the layout is improved.

  FIG. 10 is a schematic cross-sectional view for explaining still another embodiment of the package. In FIG. 10, parts having the same functions as those in FIG.

  In this embodiment, on the mounting surface 3 a of the mounting substrate 3, a bonding convex portion 3 c is formed in a bonding region with the element substrate 5. The mounting substrate 3 has a so-called cavity structure. The joining convex portion 3c is formed by processing the mounting surface 3a of the mounting substrate 3, for example. However, the bonding convex portion 3 c may be a spacer bonded to the mounting surface 3 a of the mounting substrate 3. The material of the spacer may be the same material as the mounting substrate 3 or may be a different material.

  For example, the element substrate 5 is made of silicon, and the bonding protrusion 3c is made of silicon, glass, or ceramic. In the bonding region between the mounting substrate 3 and the element substrate 5, the element substrate 5 and the bonding projection 3 c are bonded by direct bonding such as anodic bonding or silicon-silicon bonding. This eliminates the need for a bonding material such as an adhesive or a metal layer in the bonding region between the mounting substrate 3 and the element substrate 5.

  Further, on the surface of the cover substrate 7 facing the element substrate 5, a bonding convex portion 7 a is formed in a bonding region with the element substrate 5. The cover substrate 7 has a so-called cavity structure. The bonding convex portion 7 a is formed, for example, by processing the surface of the cover substrate 7 that faces the element substrate 5. However, the bonding convex portion 7 a may be a spacer bonded to the surface of the cover substrate 7 facing the element substrate 5. The material of the spacer may be the same material as the cover substrate 7 or a different material.

  Similar to the bonding between the element substrate 5 and the bonding convex portion 3c, the element substrate 5 and the bonding convex portion 7a are bonded by direct bonding. This eliminates the need for a bonding material such as an adhesive or a metal layer in the bonding region between the mounting substrate 3 and the element substrate 5.

  The combination of the material of the element substrate 5 and the material of the bonding convex portion 3c, and the combination of the material of the element substrate 5 and the material of the bonding convex portion 7c are directly bonded to the element substrate 5 and the bonding convex portions 3c and 7a. Any combination of materials that can be used is not particularly limited.

  In this embodiment, the bonding convex portion 3c is formed on the mounting substrate 3 for direct bonding between the mounting substrate 3 and the element substrate 5. However, as shown in FIG. The part 5a may be formed. In addition, as shown in FIG. 11, for the direct bonding between the element substrate 5 and the cover substrate 7, a bonding convex portion 5 b may be formed on the element substrate 5.

  The bonding convex portions 5a and 5b are formed by processing the surface of the element substrate 5, for example. However, the bonding convex portions 5 a and 5 b may be spacers bonded to the element substrate 5. The material of the spacer may be the same material as the element substrate 5 or a different material.

  The combination of the material of the mounting substrate 3 and the material of the bonding convex portion 7a and the combination of the material of the cover substrate 7 and the material of the bonding convex portion 5b are the same as the mounting substrate 3 or the cover substrate 7 and the convexity for bonding. There is no particular limitation as long as it is a combination of materials that can directly bond the portions 5a and 5b.

  Regarding the bonding of the mounting substrate 3 and the element substrate 5, the mounting substrate 3 is provided with a bonding convex portion 3 c, the element substrate 5 is provided with a bonding convex portion 5 a, and the bonding convex portions 3 c and 5 a are directly connected to each other. It may be made to join. Similarly, regarding the bonding of the element substrate 5 and the cover substrate 7, the bonding convex portion 5 b of the element substrate 5 and the bonding convex portion 7 a of the cover substrate 7 may be bonded.

  Further, regarding the bonding between the mounting substrate 3 and the element substrate 5 and the bonding between the element substrate 5 and the cover substrate 7, a configuration using the bonding convex portion 5 a and the bonding convex portion 7 a, or the bonding convex portion 3 a and the bonding substrate 7. A configuration using the convex portion 5b is also possible.

  Further, regarding the bonding between the mounting substrate 3 and the element substrate 5 and the bonding between the element substrate 5 and the cover substrate 7, one bonding is realized by direct bonding, and the other bonding is realized by bonding using a bonding material. May be.

  As mentioned above, although the Example of this invention was described, the numerical value, material, arrangement | positioning, number, etc. in the said Example are examples, This invention is not limited to these, It was described in the claim Various modifications are possible within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Package 3 Mounting substrate 3a Mounting surface 3b Back surface 5 Element substrate 7 Cover substrate 9 Embedded electrode 11 Mounting surface side light shielding film 13 Mounting surface side contact metal film 15 Mounting surface side redistribution film 17 Gas absorption material 19 Mounting surface side Metal film for bonding 21 Metal film for contact on back side 23 Element 25 Terminal for external connection 29 Metal film for contact for external connection 31 Metal film for bonding on element substrate 37 Electrical contact bonding material 39 Bonding material 49 Back surface side light shielding film 51 Back side Rewiring film

JP 2007-073721 A

Claims (20)

An element substrate on which elements are formed;
A mounting substrate on which the element substrate is mounted;
A package comprising: a light shielding film made of a metal material for shielding visible light and infrared light incident on the element from the mounting substrate side.   The package according to claim 1, further comprising a cover substrate disposed on a side opposite to the mounting substrate with respect to the element substrate. The element is an optical sensor;
The package according to claim 2, wherein the cover substrate is light transmissive.   As the light shielding film, a mounting surface side light shielding film formed on the mounting surface of the element substrate of the mounting substrate, or a back surface side light shielding film formed on the back surface opposite to the mounting surface of the mounting substrate, Or the package as described in any one of Claim 1 to 3 provided with both the said mounting surface side light shielding film and the said back surface side light shielding film. The element substrate includes a metal film for external connection contacts on a surface facing the mounting substrate,
The mounting substrate includes a mounting surface side contact metal film disposed at a position corresponding to the external connection contact metal film on the mounting surface;
The corresponding metal film for contact for external connection and the metal film for contact on the mounting surface side are electrically connected via an electrical contact bonding material,
At least the mounting surface side light shielding film is provided as the light shielding film,
The package according to claim 4, wherein the mounting surface side light shielding film and the mounting surface side contact metal film are formed of the same material. The mounting surface of the mounting substrate comprises a mounting surface side rewiring film formed simultaneously with the same material as the mounting surface side light shielding film and the mounting surface side contact metal film,
The mounting surface side rewiring film is electrically connected to the mounting surface side contact metal film, and is drawn from a position where the mounting surface side contact metal film is formed to a position different from the formation position. The package according to claim 5. The mounting substrate includes a buried electrode that is electrically connected from the back surface opposite to the mounting surface to the mounting surface;
The package according to claim 6, wherein the embedded electrode is electrically connected to the mounting surface side contact metal film through the mounting surface side redistribution film.   The element substrate and the mounting substrate are bonded by anodic bonding, silicon-silicon bonding, or bonding material in a bonding region provided at a position that does not overlap the element arrangement region. Package described in. The element substrate includes an element substrate side bonding metal film made of a metal material disposed on a surface facing the mounting substrate in a bonding region provided at a position not overlapping with the element arrangement region;
The mounting substrate includes a mounting substrate-side bonding metal film made of a metal material disposed on the mounting surface in the bonding region;
The element substrate side bonding metal film and the mounting substrate side bonding metal film are bonded via a bonding material,
At least the mounting surface side light shielding film is provided as the light shielding film,
The package according to claim 4, wherein the mounting surface side light shielding film and the mounting substrate side bonding metal film are formed of the same material. The element substrate includes a metal film for external connection contacts on a surface facing the mounting substrate,
The mounting substrate includes a mounting surface side contact metal film disposed at a position corresponding to the external connection contact metal film on the mounting surface of the mounting substrate, and a back surface opposite to the mounting surface. A buried electrode electrically connected across the mounting surface; and a back-side contact metal film disposed on the back surface and electrically connected to the mounting surface-side contact metal film via the buried electrode. Has
The corresponding metal film for contact for external connection and the metal film for contact are electrically connected via an electrical contact bonding material,
At least the back side light shielding film is provided as the light shielding film,
The package according to any one of claims 4 to 9, wherein the back-side light shielding film and the back-side contact metal film are formed of the same material. On the back surface of the mounting substrate, a back-side rewiring film formed simultaneously with the same material as the back-side light shielding film and the back-side contact metal film,
The backside redistribution film is electrically connected to the backside contact metal film, and is drawn from a position where the backside contact metal film is formed to a position different from the formation position. Package described in.   The package according to claim 1, wherein the light shielding film has a stacked structure in which a Ti layer, a Ni layer, and an Au layer are stacked in order from the lower layer side. A manufacturing method of a package comprising an element substrate on which an element is formed and a mounting substrate on which the element substrate is mounted;
A light shielding film forming step of forming a light shielding film made of a metal material disposed on the mounting substrate at a position overlapping the element placement region of the element substrate;
And a mounting step of mounting the element substrate on the mounting surface of the mounting substrate. The light shielding film forming step includes a mounting surface side contact metal film made of a metal material disposed on the mounting surface of the mounting substrate at a position corresponding to the external connection terminal of the element substrate, and the light shielding film as the light shielding film. Including a mounting surface side contact metal film forming step of simultaneously forming the mounting surface side light shielding film with the same metal material,
The mounting step mounts the element substrate on the mounting surface of the mounting substrate by electrically connecting the mounting surface side contact metal film and the external connection terminal via an electrical contact bonding material. Item 14. A method for manufacturing a package according to Item 13. An element substrate side on which an element substrate side bonding metal film made of a metal material arranged in a bonding region provided at a position not overlapping with the element arrangement region is formed on a surface of the element substrate facing the mounting substrate The method further includes a bonding metal film forming step,
In the light shielding film forming step, a mounting substrate side light shielding film made of a metal material disposed in the bonding region and a mounting surface side light shielding film as the light shielding film are formed on the mounting surface of the mounting substrate. Including a mounting substrate side bonding metal film forming step of simultaneously forming the same metal material,
The mounting step includes mounting the element substrate on the mounting surface of the mounting substrate by bonding the element substrate side bonding metal film and the mounting substrate side bonding metal film via a bonding material. Item 14. A method for manufacturing a package according to Item 13.   The light shielding film forming step is disposed on the back surface of the mounting substrate opposite to the mounting surface so as to be electrically connected to the embedded electrode that is electrically connected from the back surface to the mounting surface. 16. A backside contact metal film forming step of simultaneously forming a backside contact metal film made of a metal material and a backside light shielding film as the light shielding film with the same metal material. A method for manufacturing a package according to one item. Using an element wafer in which a plurality of the element substrates are arranged, and a mounting wafer in which a plurality of the mounting substrates are arranged corresponding to the plurality of element substrates,
The mounting substrate and the element substrate are aligned in the mounting step, and the element wafer and the mounting wafer are bonded together, and then the set of the mounting substrate and the element substrate on which the light shielding film is formed The method for manufacturing a package according to any one of claims 13 to 16, further comprising a singulation step of dividing into pieces and cutting the package.   The package manufacturing method according to any one of claims 13 to 16, further comprising a cover substrate bonding step of bonding a cover substrate to a surface of the element substrate opposite to the mounting substrate. The element is an optical sensor;
The method of manufacturing a package according to claim 18, wherein the cover substrate is light transmissive. An element wafer in which a plurality of element substrates are arranged, a mounting wafer in which a plurality of mounting substrates are arranged corresponding to the plurality of element substrates, and a plurality of elements corresponding to the plurality of element substrates Using a cover wafer on which the cover substrate is disposed,
The mounting substrate and the element substrate are aligned in the mounting step to bond the element wafer and the mounting wafer, and the element substrate and the cover substrate are aligned in the cover substrate bonding step. After the element wafer and the cover wafer are bonded, a separate process for cutting out the package by separating the set of the mounting substrate on which the light shielding film is formed, the element substrate, and the cover substrate into individual pieces is further provided. 20. The method for manufacturing a package according to claim 18 or 19, further comprising:

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