JP2007165494A - Sensor package and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable sensor package, and to provide a method for easily manufacturing such a sensor package. <P>SOLUTION: The sensor package includes a sensor body, a protective material opposite to an active surface of the sensor body via a gap portion, and a joining member circularly arranged on the outside region of the active surface of the sensor body and joining the sensor body to the protective material so that the gap portion is hermetically sealed, wherein a minute through hole drilled on a portion positioned on the gap portion of the protective material is closed with a closing member. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sensor package, and more particularly, to a hermetically sealed sensor package having a protective material on the active surface side of a sensor and a method for easily manufacturing the sensor package.

Conventionally, various MEMS (Micro Electromechanical System) sensors such as an image sensor such as a CCD and a CMOS and an acceleration sensor have been used for various applications. For example, in an image sensor, one surface of a semiconductor chip is an active surface on which a light receiving element that performs photoelectric conversion is disposed. Such a sensor has a package structure in which a protective material is disposed and hermetically sealed so as to provide a gap in the active surface of the sensor body in order to protect the active surface and ensure the operation of the sensor. (Patent Documents 1 and 2).
JP-A-8-88339 JP-A-10-135434

However, in the conventional sensor package, for example, a joining member such as solder is formed in a protective material in a desired continuous shape in advance, this protective material is brought into contact with the sensor body, and the joining member is melted at a high temperature to form a protective material. The sensor body is joined. Therefore, the gas in the space sealed at the time of bonding expands, and the bonded member in a molten state may be damaged. In this case, the hermetic sealing becomes insufficient and cannot be put to practical use. there were.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a highly reliable sensor package and a manufacturing method for easily manufacturing such a sensor package.

  In order to achieve such an object, the sensor package of the present invention includes a sensor body, a protective material facing the active surface of the sensor body via a gap, and an outer region of the active surface of the sensor body. A joining member that joins the sensor main body and the protective material so as to hermetically seal the air gap, and a fine through-hole formed in a portion of the protective material located in the air gap. And a closing member disposed in the fine through hole.

As another aspect of the present invention, the sensor main body is configured to have a plurality of terminals in a region outside the joining member.
As another aspect of the present invention, the sensor main body has a recess in a region inside the joining member, and the recess has the active surface.
As another aspect of the present invention, the protective material has a recess in a region inside the joining member, and the recess faces the active surface.
As another aspect of the present invention, the sensor main body and the protective material have the same surface area.

As another aspect of the present invention, the area of the opposing surface of the sensor body and the protective material is configured such that the area of the protective material is small.
As another aspect of the present invention, the joining member has a multi-layer structure in which metal layers are laminated on and under a brazing material layer.
As another aspect of the present invention, the brazing filler metal layer is made of Sn—Au alloy, Sn—Ag alloy, Sn—Bi alloy, Sn—Zn alloy, Sn—Pb alloy, Sn—In alloy, In—Pb alloy, or the like. The structure is either a binary system or an alloy of a ternary system or higher in which another metal is added to the binary system.
In another aspect of the present invention, the metal layer includes an Au / Ti stack, an Au / Cr stack, a Cu / Ti stack, a Cu / Cr stack, an Au / Ni / Cu / Ti stack, and an Au / Ni / Cu / Cr stack. It was set as the structure which is either.
As another aspect of the present invention, the metal layers located above and below the brazing material layer have different areas.

  The manufacturing method of the sensor package of the present invention includes the step of drilling a fine through hole in the protective material, and the active surface of the sensor body and the fine through hole of the protective material are inside the annular joint portion. A step of bonding the sensor body and the protective material through an annular bonding member; and a gap surrounded by the sensor body, the protective material, and the bonding member by closing a fine through hole of the protective material. And a step of hermetically sealing.

As another aspect of the present invention, in the step of hermetically sealing the gap, the atmosphere of the gap is made an inert gas or nitrogen gas atmosphere before the hermetic sealing.
As another aspect of the present invention, in the step of hermetically sealing the void, the void is reduced in pressure in the vacuum chamber before hermetic sealing.
As another aspect of the present invention, a metal layer is formed on the wall surface of the fine through-hole, and a metal layer is formed in advance at the joining portion of the sensor body and the protective material before joining.
As another aspect of the present invention, the sensor body and the protective material are joined in a vacuum chamber.

In such a sensor package of the present invention, since the airtightness of the gap portion where the active surface is located is high, contamination of the active surface is reliably prevented and the reliability is high.
In the sensor package manufacturing method of the present invention, when the sensor body and the protective material are joined by the joining member, even if the gas in the gap portion expands, the gas is exposed to the outside through the fine through-hole provided in the protective material. Since it can escape freely, damage to the joining member due to gas expansion is prevented, and the fine through-hole is closed after the joining of the sensor main body and the protective material is completed, so that reliable airtight sealing is possible.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Sensor package]
FIG. 1 is a plan view showing an embodiment of the sensor package of the present invention, and FIG. 2 is a schematic cross-sectional view taken along line AA of the sensor package shown in FIG. 1 and 2, the sensor package 1 of the present invention includes a sensor body 2, a protective material 6 that faces the active surface 3 of the sensor body 2 via a gap 10, and an annular region outside the active surface 3. And a bonding member 11 for bonding the sensor body 2 and the protective material 6 so as to hermetically seal the gap 10.

The sensor body 2 constituting the sensor package 1 of the present invention has an active surface 3 in a recess 4 and a plurality of terminals 5 in a region outside the joining member 11. The sensor body 2 is not particularly limited, and may be an image sensor such as a CCD or CMOS, or various MEMS (Micro Electromechanical System) sensors such as an acceleration sensor, a pressure sensor, or a gyro sensor. In addition, said active surface 3 means the area | region which expresses the desired detection function of a sensor, such as the area | region where the light receiving element which performs photoelectric conversion is arranged so that a some pixel may be comprised, for example.
The depth of the recess 4 in which the active surface 3 is located can be arbitrarily set, and can be set, for example, in the range of 5 to 200 μm. Further, the terminal 5 is connected to a desired part of the active surface by an unillustrated lead wiring or the like.

  The protective material 6 constituting the sensor package 1 has the same opposing surface shape as the opposing sensor body 2. Further, the protective material 6 includes a fine through hole 7 formed in a portion located outside the portion facing the active surface 3 and located in the gap portion 10, and a blocking member disposed in the fine through hole 7. 16. The material of the protective material 6 can be appropriately selected according to the application of the sensor package 1. For example, in the case of an image sensor such as a CCD or CMOS, an inorganic translucent member such as glass or sapphire can be cited. it can. In addition, in the case of various MEMS sensors such as an acceleration sensor, a pressure sensor, and a gyro sensor, the same silicon as the sensor body 2 may be used in consideration of matching of thermal expansion coefficients, and various metals, inorganic insulating materials, etc. There may be. The thickness of the protective material 6 can be set in the range of, for example, 0.3 to 1 mm in consideration of the material, light transmittance, and the like.

The thickness of the gap 10 existing between the protective material 6 and the active surface 3 of the sensor body 2 can be set in the range of, for example, 5 to 200 μm. The space 10 may be filled with an inert gas or a nitrogen gas to protect the active surface 3 or may be in a slightly low pressure state of about 10 ⁻² to 10 ⁻⁵ Pa.
Moreover, although the said fine through-hole 7 is one in the example of illustration, multiple (for example, 2-4 pieces) may be sufficient. Moreover, the shape of the fine through-hole 7 is not particularly limited, and the opening diameter can be set to, for example, about 5 to 200 μm.

FIG. 3 is a partial enlarged cross-sectional view for explaining the joining member 11 and the closing member 16 constituting the sensor package 1.
As shown in FIG. 3, the joining member 11 that joins the sensor body 2 and the protective material 6 has a multilayer structure in which metal layers 13 and 14 are laminated so as to sandwich the brazing material layer 12.
The brazing filler metal layer 12 is a so-called “soft brazing” having a melting point of 450 ° C. or less. For example, a Sn—Au alloy, Sn—Ag alloy, Sn—Bi alloy, Sn—Zn alloy, Sn—Pb alloy, Sn It may be a layer made of either a binary system such as an -In alloy or an In-Pb alloy, or a ternary or higher alloy in which another metal is added to the binary system. The thickness of the brazing filler metal layer 12 can be appropriately set in consideration of the set thickness of the gap 10 and the like, and can be set to about 5 to 200 μm, for example.

  Further, in the illustrated example, the metal layers 13 and 14 are a laminate of the metal layer 13a and the metal layer 13b, and a laminate of the metal layer 14a and the metal layer 14b, respectively. The metal layers 13 and 14 in such a stacked state can be, for example, an Au / Ti stack, an Au / Cr stack, a Cu / Ti stack, a Cu / Cr stack, or the like. Furthermore, in order to prevent oxidation and to improve the wettability with the brazing filler metal layer 12, a four-layer structure such as Au / Ni / Cu / Ti laminated or Au / Ni / Cu / Cr laminated may be used. The thickness of the metal layers 13 and 14 is, for example, about 0.1 to 2 μm, and the thicknesses of the metal layer 13a and the metal layer 13b, or the thicknesses of the metal layer 14a and the metal layer 14b are, for example, 0.1 to 2 μm. It can be set at about 2 μm. The metal layers 13 and 14 may be a single layer or a laminate of three or more layers including the above-described four-layer structure.

In the illustrated example, the areas of the metal layers 13 and 14 positioned above and below the brazing filler metal layer 12 are different, and the metal layer 13 is larger than the metal layer 14. This makes it possible to form a good end face shape of the brazing filler metal layer 12 when the sensor body 2 and the protective material 6 are joined in the manufacturing method of the present invention described later. This is to facilitate alignment. The metal layer 14 may be larger than the metal layer 13.
On the other hand, as shown in FIG. 3, the closing member 16 includes a metal layer 17 formed on the wall surface of the fine through hole 7 and a brazing material layer 18 filled in the fine through hole 7.

In the illustrated example, the metal layer 17 constituting the blocking member 16 is a laminate of a metal layer 17a and a metal layer 17b. For example, an Au / Ti laminate, an Au / Cr laminate, a Cu / Ti laminate, a Cu / Cr laminate, an Au / Cr laminate, Ni / Cu / Ti lamination, Au / Ni / Cu / Cr lamination, etc. can be used. The thickness of the metal layer 17 can be set to, for example, about 0.1 to 2 μm, and the thicknesses of the metal layer 17a and the metal layer 17b can be set to, for example, about 0.1 to 2 μm. The metal layer 17 may be a single layer or a laminate of three or more layers including the above four-layer structure.
The brazing filler metal layer 18 is a so-called “soft brazing” having a melting point of 450 ° C. or less. For example, a Sn—Au alloy, a Sn—Ag alloy, a Sn—Bi alloy, a Sn—Zn alloy, a Sn—Pb alloy. , Sn-In alloy, In-Pb alloy or the like, or a binary or higher alloy obtained by adding another metal to the binary system.

FIG. 4 is a schematic sectional view corresponding to FIG. 2 showing another embodiment of the sensor package of the present invention. In FIG. 4, the sensor package 21 of the present invention is annularly arranged in a sensor body 22, a protective material 26 facing the active surface 23 of the sensor body 22 via a gap 30, and an outer region of the active surface 23. And a bonding member 31 for bonding the sensor body 22 and the protective material 26 so as to hermetically seal the gap 30.
The sensor body 22 constituting the sensor package 21 is the same as the sensor body 2 described above, has an active surface 23 in the recess 24, and has a plurality of terminals 25 in a region outside the joining member 31. I have.

The protective material 26 constituting the sensor package 21 has an opposing surface shape smaller than the opposing sensor body 22, and is joined to the sensor body 22 by the joining member 31 at the peripheral corner of the face facing the sensor body 22. Has been. Further, it has a fine through hole 27 formed in a portion located outside the portion facing the active surface 23 and located in the gap portion 30, and a closing member 36 disposed in the fine through hole 27. Yes. The material and thickness of the protective material 26 are the same as those of the protective material 6 described above. Moreover, although the said fine through-hole 27 is one in the example of illustration, a plurality (for example, 2-4 pieces) may be sufficient, and it is preferable to distribute equally in this case. There is no restriction | limiting in particular in the shape of the fine through-hole 27, The opening diameter can be about 5-200 micrometers, for example.
The thickness of the gap 30 existing between the protective material 26 and the active surface 23 of the sensor body 22 can be set in the range of, for example, 5 to 200 μm. The space 30 may be filled with an inert gas or nitrogen gas to protect the active surface 23, or may be in a slightly low pressure state of about 10 ^-1 to 10 ^-5 Pa.

FIG. 5 is a partial enlarged cross-sectional view for explaining the joining member 31 and the closing member 36 constituting the sensor package 21. As shown in FIG. 5, the joining member 31 that joins the sensor body 22 and the protective material 26 has a multilayer structure in which metal layers 33 and 34 are laminated so as to sandwich the brazing material layer 32.
The material of the brazing filler metal layer 32 can be the same as that of the brazing filler metal layer 12 described above. Moreover, the thickness of the brazing filler metal layer 32 positioned between the sensor main body 22 and the protective material 26 can be appropriately set in consideration of the set thickness of the gap 30 and the like, for example, set at about 5 to 200 μm. be able to.

In the illustrated example, the metal layer 33 is a laminate of the metal layer 33a and the metal layer 33b, and can be, for example, an Au / Ti laminate, an Au / Cr laminate, a Cu / Ti laminate, a Cu / Cr laminate, or the like. The thickness of the metal layer 33 can be set to about 0.1 to 2 μm, for example, and the thicknesses of the metal layer 33a and the metal layer 33b can be set to about 5 to 200 μm, for example.
The metal layer 34 is formed at the peripheral corner of the protective material 26, and in the illustrated example, is a laminate of the metal layer 34a and the metal layer 34b. The metal layer 34 in such a laminated state is, for example, an Au / Ti laminate, an Au / Cr laminate, a Cu / Ti laminate, a Cu / Cr laminate, an Au / Ni / Cu / Ti laminate, or an Au / Ni / Cu / Cr laminate. Etc. The thickness of the metal layer 34 can be set to, for example, about 0.1 to 2 μm, and the thicknesses of the metal layer 34 a and the metal layer 34 b can be set to about 0.1 to 2 μm, for example.
The metal layers 33 and 34 may be a single layer or a laminate of three or more layers including the above four-layer structure.

In the illustrated example, the area of the metal layer 33 is larger than the area of the metal layer 34 in a portion facing the metal layer 33. This is because when the sensor main body 22 and the protective material 26 are joined, it is possible to form a good end face shape of the brazing material layer 32 and to facilitate the alignment of the sensor main body 22 and the protective material 26. .
As shown in FIG. 5, the closing member 36 includes a metal layer 37 formed on the wall surface of the fine through hole 27 and a brazing material layer 38 filled in the fine through hole 27. The closing member 36 composed of the metal layer 37 and the brazing material layer 38 can be the same as the closing member 16, the metal layer 17, and the brazing material layer 18 of the above-described embodiment.

FIG. 6 is a schematic sectional view corresponding to FIG. 2 showing another embodiment of the sensor package of the present invention. In FIG. 6, the sensor package 41 of the present invention is annularly arranged in a sensor main body 42, a protective material 46 facing the active surface 43 of the sensor main body 42 through a gap 50, and an outer region of the active surface 43. And a bonding member 51 for bonding the sensor body 42 and the protective material 46 so as to hermetically seal the gap 50.
The sensor body 42 constituting the sensor package 41 is the same as the above-described sensor body 2 except that it does not have a recess, and includes a plurality of terminals 45 in a region outside the joining member 51. .

The protective material 46 constituting the sensor package 41 is the same as the protective material 6 described above, except that a concave portion 48 corresponding to the shape of the active surface 43 is provided on the surface facing the active surface 43. The depth of the recessed part 48 can be set arbitrarily, for example, can be set in the range of 5-200 micrometers. Further, the protective material 46 includes a fine through hole 47 formed in a part located outside the part facing the active surface 43 and located in the gap 50, and a blocking member disposed in the fine through hole 47. 56. It should be noted that the drilled portion of the fine through hole 47 may be inside the recess 48 or outside it.
The material and thickness of the protective material 46 are the same as those of the protective material 6 described above. Moreover, the opening diameter of said fine through-hole 47 can be about 5-200 micrometers, for example.
Further, the joining member 51 constituting the sensor package 41 and the closing member 56 for closing the fine through hole 47 are the same as the joining member 11 and the closing member 16 in the above-described embodiment.

The thickness of the gap 50 existing between the protective material 46 and the active surface 43 of the sensor body 42 can be set, for example, in the range of 5 to 200 μm. The gap 50 may be filled with an inert gas or nitrogen gas to protect the active surface 43, and may be in a slightly low pressure state of about 10 ⁻¹ to 10 ⁻⁵ Pa, for example. Good.
In the sensor package 21 according to the above-described embodiment, the sensor body 22 that does not have the recess 24 is used, and the protective material 26 has the active surface 23 on the surface facing the active surface 23. The thing provided with the recessed part corresponding to a shape can be used.

FIG. 7 is a schematic cross-sectional view corresponding to FIG. 2 showing another embodiment of the sensor package of the present invention. In FIG. 7, the sensor package 61 of the present invention is annularly disposed in a sensor body 62, a protective material 66 facing the active surface 63 of the sensor body 62 via a gap 70, and an outer region of the active surface 63. And a joining member 71 for joining the sensor body 62 and the protective material 66 so as to hermetically seal the gap 70.
The sensor main body 62 constituting the sensor package 61 is similar to the sensor main body 2 described above, and includes a plurality of terminals 65 in a region outside the joining member 71.

  The protective material 66 constituting the sensor package 61 is the same as the protective material 46 described above, except that a recess 68 corresponding to the shape of the active surface 63 is provided on the surface facing the active surface 63. This is the same as the protective material 6 of the above-described embodiment. The depth of the recessed part 68 can be set arbitrarily, for example, can be set in the range of 5-200 micrometers. Further, the protective material 66 includes a fine through hole 67 formed in a portion located outside the portion facing the active surface 63 and located in the gap 70, and a blocking member disposed in the fine through hole 67. 76. It should be noted that the drilled portion of the fine through hole 67 may be inside the recess 68 or outside the recess 68.

The material and thickness of the protective material 66 are the same as those of the protective material 6 described above. Moreover, the opening diameter of said fine through-hole 67 can be about 5-200 micrometers, for example.
Further, the joining member 71 constituting the sensor package 61 and the closing member 76 for closing the fine through hole 67 are the same as the joining member 11 and the closing member 16 in the above-described embodiment.
The thickness of the gap 70 existing between the protective material 66 and the active surface 63 of the sensor body 62 can be set in the range of 10 to 400 μm, for example. The gap 70 may be filled with an inert gas or a nitrogen gas to protect the active surface 63, and may be in a slightly low pressure state of about 10 ⁻¹ to 10 ⁻⁵ Pa, for example. Good.
In the sensor package 21 according to the above-described embodiment, the protective material 26 having a recess corresponding to the shape of the active surface 23 on the surface facing the active surface 23 can be used.

The sensor package of the present invention as described above has high airtightness in the gap where the active surface of the sensor body is located. For example, the He leak rate is 10 ⁻⁹ atm · cc / sec or less, preferably 10 ⁻¹² atm · High airtightness of cc / second or less is obtained, and contamination of the active surface is reliably prevented by the protective material.
The above-described sensor package is an example, and the present invention is not limited to the above-described embodiment. For example, in consideration of the case where the protective material in the above-described embodiment is an image sensor such as a CCD or CMOS, a position that is inside the annular joint member and outside the opposing active surface However, when the sensor body is not an image sensor but various MEMS sensors such as an acceleration sensor, a pressure sensor, a gyro sensor, etc., the position of the fine through hole may be located inside the annular joint member, and the active surface It may be located in the opposite part.

[Method for manufacturing sensor package]
Next, the manufacturing method of the sensor package of this invention is demonstrated.
8 and 9 are process diagrams showing an embodiment of the sensor package manufacturing method of the present invention, taking the sensor package 1 shown in FIGS. 1 to 3 as an example.
First, the sensor body 2 is manufactured, and the fine through-hole 7 is formed in the protective material 6 (FIG. 8A). The sensor body 2 is manufactured, for example, by dividing a silicon wafer by multiple impositions, and for each imposition, for example, using a MEMS (Micro Electromechanical System) method or the like. The produced sensor body 2 has an active surface 3 in the recess 4 and a plurality of terminals 5 in a region outside the portion where the annular bonding member 11 is disposed in a later process.

  The fine through-holes 7 are formed in the protective material 6 by, for example, forming a mask pattern having a desired opening for each imposition of the protective material 6 divided by multiple imposition and exposing the exposed portion. The etching can be carried out by ICP-RIE (Inductively Coupled Plasma-Reactive Ion Etching), which is a dry etching method using plasma. Further, the fine through-hole 7 can be formed by a sand blast method, a wet etching method, or a femtosecond laser method. Such a fine through-hole 7 is formed at a position inside the annular joining member 11 to be described later and outside the active surface 3 that faces it.

  In this step, the metal layer 13 constituting the joining member 11 is formed in an annular shape at a predetermined portion of the sensor body 2, and the metal layer 14 constituting the joining member 11 is formed in an annular shape at a predetermined portion of the protective material 6. Is preferred. The formation method of the metal layers 13 and 14 is not particularly limited. For example, a base conductive thin film such as a Ti thin film is formed by a vacuum film formation method or an electroless plating method, and this corresponds to a bonding member formation site on the base conductive thin film. After forming a resist pattern having an opening to be formed, a conductive material such as Au is deposited by electrolytic plating using the underlying conductive thin film as a power feeding layer, and then the resist pattern and the exposed underlying conductive thin film are removed. can do. Further, using the resist pattern formed on the sensor body 2 and the protective material 6 as a mask, a laminated film of a Ti layer and an Au layer is formed by a vacuum film forming method, and then the resist pattern is removed to form the metal layers 13 and 14. It may be formed.

  In this step, it is preferable to form the metal layer 17 constituting the closing member 16 on the wall surface of the fine through hole 7 formed in the protective material 6. There is no particular limitation on the method of forming the metal layer 17. For example, a base conductive thin film such as a Ti thin film is formed on the protective material 6 including the wall surface of the fine through-hole 7 by vacuum film formation or electroless plating. After forming a resist pattern on the base conductive thin film excluding the base conductive thin film located on the wall surface of the fine through-hole 7, a conductive material such as Au is deposited by electrolytic plating using the base conductive thin film as a feeding layer, and then the resist pattern And the exposed underlying conductive thin film can be removed. Further, using a resist pattern formed so that the fine through hole 7 of the protective material 6 is exposed as a mask, a laminated film of a Ti layer, an Au layer, or the like is formed on the inner wall surface of the fine through hole 7 by a vacuum film forming method. The metal layer 17 may be formed by removing the resist pattern.

  Next, the sensor main body 2 and the protective material 6 are joined in a multi-faceted state via the annular joint member 11 to form a gap 10 surrounded by the sensor main body 2, the protective material 6 and the joint member 11. (FIG. 8 (B)). As described above, the joining member 11 has a multilayer structure composed of the brazing material layer 12 and the metal layers 13 and 14, and the annular metal layers 13 and 14 are respectively attached to the sensor body 2 and the protective material 6 in the previous step. Is formed. Therefore, for example, the brazing material layer 12 is formed on the metal layer 14 previously formed on the protective material 6, and the sensor body 2 and the protective material 6 are opposed so that the brazing material layer 12 contacts the metal layer 13. The brazing filler metal layer 12 can be melted by heating in this state, and then solidified and joined. In this joining step, in the present invention, since the fine through hole 7 of the protective material 6 is present inside the annular joining portion, even if the gas in the gap portion 10 expands, the gas passes through the fine through hole 7. It is possible to escape to the outside freely, and the stress of gas expansion is prevented from acting on the brazing filler metal layer 12 in the molten state.

Moreover, in this joining process, since the area of the metal layer 13 formed on the sensor body 2 is larger than the area of the metal layer 14 formed on the protective material 6, the end face shape is good when the brazing material layer 12 is melt-joined. The brazing material layer 12 can be formed, and the alignment between the sensor body 2 and the protective material 6 is facilitated.
Next, the sensor body 2 and the protective material 6 joined by the joining member 11 are placed in the vacuum chamber 100, and the inside of the vacuum chamber 100 is depressurized to about 10 ⁻¹ to 10 ⁻⁶ Pa (FIG. 8C). . After that, an inert gas (for example, He) or nitrogen gas is introduced into the vacuum chamber 100 to a normal pressure (FIG. 9A). Thereby, the atmosphere of the cavity 10 is made an inert gas or nitrogen gas atmosphere.

Next, in the vacuum chamber, the fine through-hole 7 of the protective material 6 is closed to hermetically seal the gap 10 (FIG. 9B). The fine through hole 7 can be closed by injecting a molten brazing material into the fine through hole 7 in which the metal layer 17 is formed on the wall surface and solidifying it to form the brazing material layer 18. Thus, since the fine through hole 7 is closed after the joining of the sensor body 2 and the protective material 6 by the joining member 11 is completed, the airtight sealing of the gap 10 is ensured. The fine through holes 7 are preferably closed at room temperature (20 to 30 ° C.).
Next, the sensor package 1 of the present invention is obtained by dicing the multi-sided sensor body and the protective material.
Further, in the case where the gap portion 10 of the sensor package 1 is set to a low pressure state without an atmosphere of inert gas or nitrogen gas, the vacuum chamber 100 is decompressed (shown in the above FIG. 8C). In this state, the fine through hole 7 of the protective material 6 is closed to hermetically seal the gap 10.
In the manufacturing method of the present invention, the step of joining the sensor body 2 and the protective material 6 via the annular joining member 11 may be performed in the vacuum chamber 100.

When the protective material 26 is smaller than the sensor body 22 as in the sensor package 21 shown in FIG. 4, the protective material is individually bonded to each imposition of the multi-face sensor body. Furthermore, a multi-sided sensor body may be diced to prepare individual sensor bodies, and a protective material may be bonded thereto.
In addition, the manufacturing method of the sensor package of the above-mentioned this invention is an illustration, and this invention is not limited to these embodiment. For example, in consideration of the case of an image sensor such as a CCD or a CMOS, the position where the fine through hole of the protective material is drilled in the above embodiment is inside the annular joint member and outside the opposing active surface. However, when the sensor body is not an image sensor but various MEMS sensors such as an acceleration sensor, a pressure sensor, and a gyro sensor, the drilling position of the fine through hole is located inside the annular joint member. What is necessary is just to be sufficient, and it may be located in the site | part facing an active surface.

Next, the present invention will be described in more detail with specific examples.
[Example]
First, a silicon wafer having a thickness of 625 μm was prepared, and was divided into multiple faces with a square having a side of 5 mm. Silicon oxide films (thickness 3 μm) were formed on both sides of this silicon wafer by plasma CVD.
Next, a sensor main body (active surface dimensions: 3500 μm × 3500 μm, recess dimensions: 4000 μm × 4000 μm, depth 100 μm) was prepared for each imposition of the silicon wafer by a conventional method. Each sensor body was provided with 20 terminals (5 on each side) around the active surface.

Next, a positive photoresist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied, exposed and developed through a desired photomask, and a resist pattern is formed for each imposition. A laminated film of a Ti layer (thickness 0.1 μm) and an Au layer (thickness 0.2 μm) was formed by a vacuum film forming method using the mask. Thus, around the active surface of the sensor main body, inside the terminal array, a 300 μm wide metal layer, which is a stack of a Ti layer and an Au layer, is annular (size of the center part in the width direction of the metal layer: 4350 μm × 4350 μm).
On the other hand, a glass substrate having a thickness of 500 μm was prepared as a protective material, and was divided into multiple faces with a square having a side of 5 mm.

Next, a silicon nitride film (thickness 3 μm) was formed on one surface of the glass substrate by plasma CVD. Next, a positive photoresist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied onto the silicon nitride film, and a resist pattern is formed by exposure and development through a photomask for forming fine through holes. did. Next, the silicon nitride film exposed from the resist pattern was dry etched using CF ₄ as an etching gas, and then the resist pattern was peeled off to form a mask pattern made of a silicon nitride film. The mask pattern had one circular opening with a diameter of 30 μm at a position 3000 μm away from the center in a diagonal direction for each imposition of the glass substrate. Next, from the mask pattern side, the glass substrate was dry-etched using SF ₆ as an etching gas by an ICP-RIE apparatus. As a result, a tapered fine through hole having an opening diameter of 30 μm on the surface provided with the silicon nitride film and an opening diameter of 25 μm on the opposite surface was formed.

Next, a positive photoresist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied on the silicon nitride film, and exposed and developed through a desired photomask. As a result, for each imposition, the fine through hole was exposed, and a resist pattern having an annular opening having a width of 200 μm (a dimension of the central portion in the width direction of the opening: 4350 μm × 4350 μm) was formed. Using this resist pattern as a mask, a laminated film of a Ti layer (thickness 0.1 μm) and an Au layer (thickness 0.2 μm) was formed by vacuum deposition, and then the resist pattern was peeled off. As a result, a metal layer that is a laminate of the Ti layer and the Au layer is formed on the wall surface of the fine through hole on each imposition of the protective material, and a Ti layer and an Au layer are laminated on one surface of the protective material A metal layer having a width of 200 μm was formed in a ring shape (dimension at the center in the width direction of the metal layer: 4350 μm × 4350 μm).
Next, a Sn—Au alloy (melting point 350 ° C.) was melt-extruded on each metal layer formed on the protective material to form a brazing material layer having a width of 150 μm and a height of 100 μm.

Next, in the air, the multi-sided sensor body and the protective material are aligned and pressure-bonded so that the brazing material layer contacts the metal layer of the sensor body, and heated at 370 ° C. for 5 minutes. And cooled to room temperature. This completed the joining of the multi-sided sensor body and the protective material, and a gap of about 60 μm in height was formed between the active surface of the sensor body and the protective material.
Next, the multi-sided sensor main body and the protective material that had been joined were placed in a vacuum chamber, and the vacuum chamber was depressurized to 10 ⁻³ Pa. Next, He gas was supplied to the vacuum chamber to bring the inside to normal pressure (1 atm).
Next, the inside of the vacuum chamber was set to 25 ° C., and the molten Sn—Au alloy was dropped into the fine through hole, filled, and solidified to close the fine through hole. Thereafter, the multi-sided substrate was taken out from the vacuum chamber and diced to obtain a sensor package as shown in FIG.

As a result of measuring the He leak rate for the sensor package thus fabricated under the following conditions, it was 10 ⁻¹² atm · cc / sec, and it was confirmed that high airtightness was ensured.
(Measurement conditions of He leak rate)
The container containing the sensor package is depressurized to 10 ^-4 Pa and the amount of He leaking from the sensor package while it is left for 120 minutes is measured by a He detector
(Manufactured by ASM-180TD).

[Comparative example]
In the same manner as in the example, a multi-sided sensor body was produced and a metal layer was formed.
Further, a multi-sided protective material was prepared and a metal layer was formed in the same manner as in the example except that the fine through-hole was not formed in the protective material.
Next, the multi-sided sensor main body and the protective material were joined in the same manner as in Example except that the joining was performed in a He atmosphere, and then the multi-sided substrate was diced to obtain a sensor package. .
As a result of measuring the He leak rate for the sensor package thus produced in the same manner as in the example, it was 10 ⁻⁶ atm · cc / sec, and the practical level of airtightness (10 ⁻⁹ atm · cc / sec or less) was obtained. It was confirmed that it was not obtained.

  The present invention can be applied in various fields where a small and highly reliable sensor is required.

It is a top view which shows one Embodiment of the sensor package of this invention. It is a schematic sectional drawing in the AA line of the sensor package shown by FIG. 1. Partial enlargement for explaining the joining member and the closing member constituting the sensor package shown in FIG. It is a schematic sectional drawing equivalent to FIG. 2 which shows other embodiment of the sensor package of this invention. Partial enlargement for explaining the joining member and the closing member constituting the sensor package shown in FIG. It is a schematic sectional drawing equivalent to FIG. 2 which shows other embodiment of the sensor package of this invention. It is a schematic sectional drawing equivalent to FIG. 2 which shows other embodiment of the sensor package of this invention. It is process drawing which shows one Embodiment of the manufacturing method of the sensor package of this invention. It is process drawing which shows one Embodiment of the manufacturing method of the sensor package of this invention.

Explanation of symbols

1, 21, 41, 61 ... sensor package 2, 22, 42, 62 ... sensor body 3, 23, 43, 63 ... active surface 6, 26, 46, 66 ... protective material 7, 27, 47, 67 ... fine penetration Hole 10, 30, 50, 70 ... Gap 11, 31, 51, 71 ... Joining member 16, 36, 56, 76 ... Closure member

Claims (15)

  A sensor body, a protective material facing the active surface of the sensor body via a gap, and an annularly disposed outer region of the active surface of the sensor body so as to hermetically seal the gap A joining member that joins the main body and the protective material; a fine through-hole formed in a portion of the protective material located in the gap portion; and a blocking member disposed in the fine through-hole. Sensor package characterized by that.   The sensor package according to claim 1, wherein the sensor body has a plurality of terminals in a region outside the joining member.   The sensor package according to claim 1, wherein the sensor main body has a concave portion in a region inside the joining member, and the active surface is provided in the concave portion.   The sensor package according to any one of claims 1 to 3, wherein the protective material has a recess in a region inside the joining member, and the recess faces the active surface.   5. The sensor package according to claim 1, wherein the sensor main body and the protective material have the same surface area.   The sensor package according to any one of claims 1 to 4, wherein an area of a surface of the sensor body and the protective material facing each other is small.   The sensor package according to any one of claims 1 to 6, wherein the joining member has a multilayer structure in which metal layers are laminated on and under a brazing material layer.   The brazing filler metal layer may be a binary system such as Sn—Au alloy, Sn—Ag alloy, Sn—Bi alloy, Sn—Zn alloy, Sn—Pb alloy, Sn—In alloy, In—Pb alloy, or the like. 8. The sensor package according to claim 7, wherein the sensor package is any one of ternary and higher alloys obtained by adding other metals to the system.   The metal layer is any one of an Au / Ti stack, an Au / Cr stack, a Cu / Ti stack, a Cu / Cr stack, an Au / Ni / Cu / Ti stack, and an Au / Ni / Cu / Cr stack. The sensor package according to claim 7 or 8.   The sensor package according to any one of claims 7 to 9, wherein areas of the metal layers located above and below the brazing material layer are different. Drilling fine through holes in the protective material;
Joining the sensor body and the protective material via an annular joining member so that the active surface of the sensor body and the fine through hole of the protective material are inside the annular joint portion;
A method of manufacturing a sensor package, comprising: sealing a fine through hole of the protective material to hermetically seal a gap surrounded by the sensor body, the protective material, and the bonding member.   12. The method of manufacturing a sensor package according to claim 11, wherein in the step of hermetically sealing the gap, the atmosphere of the gap is made an inert gas or nitrogen gas atmosphere before the hermetic sealing.   The method for manufacturing a sensor package according to claim 11, wherein, in the step of hermetically sealing the gap, the gap is reduced in pressure by reducing the pressure in a vacuum chamber before hermetically sealing.   The metal layer is formed on the wall surface of the fine through-hole, and the metal layer is formed in advance at the joining portion of the sensor body and the protective material before joining. A method for manufacturing the sensor package according to claim 1.   The method for manufacturing a sensor package according to claim 11, wherein the step of joining the sensor body and the protective material is performed in a vacuum chamber.

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