JP2003156400A - Package for pressure detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure detector that can accurately detect its external pressure over a long period. SOLUTION: A package for pressure detector is composed of a ceramic substrate 1 and a ceramic plate 2. The ceramic substrate 1 has a mounting section 1b, on which a semiconductor element 3 is mounted on one main surface and a first metallized electrode 7 for forming electrostatic capacitance and a first metallized layer 8 for junction surrounding the electrode 7 on the other main surface. The ceramic plate 2 has a projection section 2a, in the outer peripheral section of one main surface, a second metallized electrode 9 facing the first metallized electrode 7 on the main surface surrounded by the projecting section 2a, and a second metallized layer 10 for junction brazed to the first metallized layer 8 via a brazing material 11 on the projecting section 2a. The plate 2 is bonded flexibly to the ceramic substrate 1, so as to form a hermetically sealed space between the other main surface of the substrate 1 and the plate 2, and the brazing material 11 has a thickness of 5-30 μm.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure detecting device package used for a pressure detecting device for detecting pressure. 2. Description of the Related Art Conventionally, a capacitance type pressure detecting device has been known as a pressure detecting device for detecting pressure. As shown in a sectional view of FIG. 2, for example, a capacitance type pressure sensing device 22 and a package 28 are mounted on a wiring board 21 made of a ceramic material or a resin material.
And a semiconductor element 29 for arithmetic operation housed in the computer. The pressure-sensitive element 22 is made of, for example, an electrically insulating material such as a ceramic material.
An insulating substrate 24 having a concave portion to which
An insulating plate 26, which is joined in a flexible state so as to form a closed space between the insulating base 24 and the upper surface of the insulating substrate 24, and the other electrode 25 for forming a capacitance is adhered to the lower surface, And external lead terminals 27 for electrically connecting each of the capacitance forming electrodes 23 and 25 to the outside. Each of the static electricity generating plates 23 and 25 is formed by bending the insulating plate 26 in response to external pressure. The capacitance formed between the capacitance forming electrodes 23 and 25 changes.
An external pressure can be detected by subjecting this change in capacitance to arithmetic processing by the semiconductor element 29 for arithmetic operation. [0003] However, according to this conventional pressure detecting device, the pressure-sensitive element 22 and the semiconductor element 29 are not provided.
Are individually mounted on the wiring board 21, which increases the size of the pressure detection device and the pressure detection electrode.
The wiring between 23 and 25 and the semiconductor element 29 becomes longer,
There is a problem that the sensitivity is low because an unnecessary capacitance is formed between the long wires. Accordingly, the applicant of the present application has previously filed Japanese Patent Application No. 2000-178.
618, an insulating base made of a ceramic material having a mounting portion on which a semiconductor element is mounted on one main surface, and disposed on the surface and inside of the insulating base, and each electrode of the semiconductor element is electrically connected. A plurality of wiring conductors to be
A first electrode for forming a capacitance, which is attached to the center of the other main surface of the insulating base and is electrically connected to one of the wiring conductors, An insulating plate made of a ceramic material joined in a flexible state so as to form a sealed space with the center of the main surface; and an inner main surface of the insulating plate attached to the inner main surface facing the first electrode. Thus, a pressure detection device package including a second electrode for forming a capacitance electrically connected to another one of the wiring conductors has been proposed. According to this pressure detecting device package, a first electrode for forming a capacitance is provided on the other main surface of the insulating base having a mounting portion on which a semiconductor element is mounted on one main surface, and the first electrode is provided on the first electrode. Since the insulating plate having the opposing second electrode for capacitance formation on the inner surface thereof was joined in a flexible state so as to form a sealed space between the other main surface of the insulating base, The pressure-sensitive element is formed integrally with the package containing the semiconductor element. As a result, the pressure detection device can be made small and the wiring connecting the electrode for pressure detection and the semiconductor element is shortened. Unnecessary capacitance generated between the wirings can be reduced. In the package for a pressure detecting device proposed in Japanese Patent Application No. 2000-178618, for example, a frame made of ceramics or metal is provided on the outer peripheral portion of the other main surface of the insulating base so as to surround the first electrode. The insulating plate was joined to the insulating base by brazing the outer peripheral portion of the second electrode on the frame via a silver-copper solder having a thickness of about 50 μm. However, according to the pressure sensing device package proposed in Japanese Patent Application No. 2000-178618, the brazing material made of silver-copper brazing for joining the insulating base and the insulating plate is liable to undergo plastic deformation due to large stress. When a large external pressure is applied to the insulating plate for a long period of time, the stress generated by the bending of the insulating plate acts on the inner peripheral edge of the brazing material having a thickness of about 50 μm joining the insulating base and the insulating plate. As a result, large plastic deformation occurs in the brazing material, and as a result, the insulating plate does not completely return to the original position even when the pressure is released, so that the external pressure can be accurately detected. There was a problem that it disappeared. The present invention has been completed in view of the above-mentioned problems, and an object of the present invention is to provide a pressure detecting device capable of accurately detecting external pressure over a long period of time. A package for a pressure detecting device according to the present invention has a plurality of metallized wiring conductors inside and on the surface, and has a mounting portion on which a semiconductor element is mounted on one main surface and the other. A first metallized electrode for forming a capacitance electrically connected to one of the metallized wiring conductors on a main surface thereof and surrounding the first metallized electrode and electrically connected to another one of the metallized wiring conductors Ceramic substrate having a frame-shaped first metallization layer for the frame,
While having a frame-shaped projection on the outer periphery of one main surface,
One main surface surrounded by the protrusion is electrically connected to the second metallized electrode on the second metallized electrode for capacitance formation facing the first metallized electrode and the protrusion, and the A second joining metallization layer in the form of a frame brazed to the first joining metallization layer with a brazing material interposed therebetween so as to form an enclosed space between the ceramic substrate and the other main surface; A pressure sensing device package comprising a ceramic plate bonded to the ceramic base in a flexed state, wherein a thickness of a brazing material for brazing the first bonding metallization layer and the second bonding metallization layer is reduced. The thickness is 5 to 30 μm. According to the pressure detecting device package of the present invention, a brazing material for brazing the first joining metallized layer provided on the ceramic base and the second joining metallized layer provided on the projection of the ceramic plate. Since the thickness of the brazing material is as thin as 5 to 30 μm, even if an external pressure is applied to the ceramic plate for a long time, the plastic deformation of the brazing material can be made extremely small. Next, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view illustrating an example of an embodiment of a package for a pressure detection device according to the present invention.
1 is a ceramic base, 2 is a ceramic plate, 3 is a semiconductor element. The ceramic substrate 1 is a laminated body made of a ceramic material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, and a glass-ceramic. If this is the case, an appropriate organic binder, solvent, plasticizer, and dispersant are added to ceramic raw material powder such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide to form a slurry, which is well known in the art. A plurality of ceramic green sheets are obtained by forming the sheet into a sheet shape by employing the doctor blade method described above, and then the ceramic base sheet 1 is subjected to appropriate punching, laminating, and cutting to obtain a ceramic base 1. And a green ceramic molded body for about 1600 ° C. It is manufactured by firing at a temperature of The ceramic substrate 1 has a concave portion 1a for accommodating the semiconductor element 3 in the center of the lower surface thereof, and thereby functions as a container for accommodating the semiconductor element 3. The center of the bottom surface of the concave portion 1a is a mounting portion 1b on which the semiconductor element 3 is mounted.
The semiconductor element 3 is sealed by mounting the semiconductor element 3 on the substrate b and filling the recess 1a with a resin sealing material 4 such as an epoxy resin. In this example, the semiconductor element 3 is sealed by filling a resin sealing material 4 in the recess 1a. However, the semiconductor element 3 is provided with a lid made of metal or ceramic on the lower surface of the ceramic base 1 in the recess 1a. May be sealed by joining them so as to close them. A plurality of metallized wiring conductors 5 connected to the respective electrodes of the semiconductor element 3 are led out from the mounting portion 1b. The metallized wiring conductor 5 and the respective electrodes of the semiconductor element 3 are connected to the solder bumps 6 and the like. By bonding via a conductive bonding member made of a conductive material, each electrode of the semiconductor element 3 and each metallized wiring conductor 5 are electrically connected, and the semiconductor element 3 is fixed to the mounting portion 1b. In this example, the electrodes of the semiconductor element 3 and the metallized wiring conductors 5 are connected via the solder bumps 6, but the electrodes of the semiconductor element 3 and the metallized wiring conductors 5 are connected to another type of electric wire such as a bonding wire. May be connected by a dynamic connection means. The metallized wiring conductor 5 functions as a conductive path for electrically connecting each electrode of the semiconductor element 3 to an external electric circuit and a first metallized electrode 7 and a second metallized electrode 9 to be described later. Is led out to the lower surface of the outer periphery of the ceramic base 1, and another part is electrically connected to the first metallized electrode 7 and the second metallized electrode 9. The electrodes of the semiconductor element 3 are electrically connected to the metallized wiring conductors 5 via a conductive bonding material, and the semiconductor element 3 is sealed with a resin sealing material 4. The semiconductor element 3 housed inside is electrically connected to the external electric circuit by joining the portion led out to the lower surface of the outer periphery of the ceramic base 1 to the wiring conductor of the external electric circuit board via a conductive bonding material such as solder. The Rukoto. The metallized wiring conductor 5 is made of metal powder such as tungsten, molybdenum, copper, silver or the like, and is mixed with a metal powder such as tungsten by adding an appropriate organic binder, solvent, plasticizer, dispersant and the like. The metallized paste thus obtained is printed and applied in a predetermined pattern on a ceramic green sheet for the ceramic substrate 1 by employing a conventionally well-known screen printing method, and is fired together with the green ceramic molded body for the ceramic substrate 1 to obtain a ceramic. A predetermined pattern is formed inside and on the surface of the base 1. In order to prevent the metallized wiring conductor 5 from being oxidized and corroded, and to improve the bonding between the metallized wiring conductor 5 and a conductive bonding material such as solder, the surface of the metallized wiring conductor 5 is usually formed on a surface thereof. If thickness is 1
Nickel plating layer of ~ 10μm and thickness of 0.1 ～ 3μm
Gold plating layers are sequentially applied. A first metallized electrode 7 for forming a capacitance is attached to the center of the upper surface of the ceramic substrate 1. The first metallized electrode 7 is for forming a capacitance for a pressure-sensitive element together with a second metallized electrode 9 described later, and is formed, for example, in a substantially circular pattern. One of the metallized wiring conductors 5a is connected to the first metallized electrode 7 so that the electrode of the semiconductor element 3 is connected to the metallized wiring conductor 5a via a conductive bonding material such as a solder bump 6. When connected, the electrode of the semiconductor element 3 and the first metallized electrode 7 are electrically connected. The first metallized electrode 7 is made of metal powder such as tungsten, molybdenum, copper, silver or the like having a thickness of about 10 to 50 μm, and has an organic binder, solvent, plasticizer suitable for the metal powder such as tungsten. A metallized paste obtained by adding and mixing a dispersant is applied to a ceramic green sheet for the ceramic substrate 1 by printing using a conventionally known screen printing method, and is fired together with the green ceramic molded body for the ceramic substrate 1. Thus, a predetermined pattern is formed at the center of the upper surface of the ceramic base 1. In addition, a nickel plating layer having a thickness of about 1 to 10 μm is usually applied to the surface of the first metallized electrode 7 in order to prevent the first metallized electrode 7 from being oxidized and corroded. A substantially circular or substantially octagonal frame-like first bonding metallization layer 8 surrounding the first metallization electrode 7 is applied to the outer peripheral portion of the upper surface of the ceramic base 1. The first bonding metallization layer 8 functions as a base metal for bonding the ceramic plate 2 to the ceramic base 1, and the first bonding metallization layer 8 has a second metallization electrode 9 and a second metallization electrode 9 on its lower surface. The ceramic plate 2 having the second bonding metallization layer 10 electrically connected to the second bonding metallization layer 9 and the second bonding metallization layer 10 and the first bonding metallization layer 8
And brazing through a brazing material 11 such as silver-copper brazing. One of the metallization wiring conductors 5b is connected to the first bonding metallization layer 8, so that the electrode of the semiconductor element 3 is connected to the metallization wiring conductor 5b by a conductive bonding material such as a solder bump 6. And the second metallized electrode 9 is electrically connected. Such a first bonding metallization layer 8 is
Metallization paste made of metal powders such as tungsten, molybdenum, copper, silver, etc. The ceramic green sheet for the ceramic substrate 1 is adopted and printed, and is fired together with the green ceramic molded body for the ceramic substrate 1 to thereby form the ceramic substrate 1.
Is formed in a frame-shaped predetermined pattern on the outer peripheral portion of the upper surface of. The surface of the first bonding metallization layer 8 is prevented from being oxidized and corroded on the surface of the first bonding metallization layer 8 and the bonding between the first bonding metallization layer 8 and the brazing material 11 is firmly formed. For this purpose, a nickel plating layer having a thickness of about 1 to 10 μm is usually applied. The ceramic plate 2 attached to the upper surface of the ceramic base 1 is made of a ceramic material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, or a glass-ceramic. It is a substantially flat plate such as a square, a substantially octagon, or a circle, and has a frame-shaped projection 2a on the outer peripheral portion of the inner main surface. Then, the central portion functions as a so-called pressure detecting diaphragm whose central portion bends toward the ceramic base 1 in response to external pressure. If the thickness of the central portion of the ceramic plate 2 is less than 0.01 mm, the mechanical strength of the ceramic plate 2 is small, and thus the ceramic plate 2 may be broken when a large external pressure is applied thereto. On the other hand, if the thickness of the central portion exceeds 5 mm, it becomes difficult to bend under a small pressure, and it becomes unsuitable as a diaphragm for pressure detection. Therefore, the thickness of the central portion of the ceramic plate 2 is preferably in the range of 0.01 to 5 mm. If the height of the projection 2a is less than 0.01 mm, the gap formed between the ceramic base 1 and the ceramic plate 2 becomes too narrow, and the first metallization occurs when pressure is applied to the ceramic plate 2. The risk of contact between the electrode 7 and the second metallized electrode 9 increases, while if the height of the protrusion 2a exceeds 5 mm, the distance between the first metallized electrode 7 and the second metallized electrode 9 increases. The formed capacitance is small, and the sensitivity of the pressure-sensitive element is reduced. Therefore, the height of the projection 2a is preferably in the range of 0.01 to 5 mm. When such a ceramic plate 2 is made of, for example, an aluminum oxide sintered body, an organic binder, a solvent, and a plastic suitable for ceramic raw material powder such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide. A ceramic green sheet is obtained by adding and mixing an agent and a dispersant to form a slurry, and forming this into a sheet by employing a conventionally known doctor blade method. The green ceramic molded body for the ceramic plate 2 is obtained by punching and cutting, and the green ceramic molded body is manufactured by firing at a temperature of about 1600 ° C. On the lower surface of the ceramic plate 2, a second metallized electrode 9 for forming a capacitance, which is opposed to the first metallized electrode 7, is attached at the center. The second metallized electrode 9 is for forming a capacitance for a pressure-sensitive element together with the first metallized electrode 7 described above, and is formed, for example, in a substantially circular pattern. The second metallized electrode 9 is made of metal powder such as tungsten, molybdenum, copper, silver or the like having a thickness of about 10 to 50 μm, and an organic binder, solvent, plasticizer suitable for the metal powder such as tungsten. A metallized paste obtained by adding and mixing a dispersant is applied onto a ceramic green sheet for the ceramic plate 2 by printing using a conventionally known screen printing method, and is fired together with a green ceramic molded body for the ceramic plate 2. Thus, a predetermined pattern is formed at the center of the lower surface of the ceramic plate 2. In addition, a nickel plating layer having a thickness of about 1 to 10 μm is usually applied to the surface of the second metallized electrode 9 in order to prevent the second metallized electrode 9 from being oxidized and corroded. Furthermore, a substantially circular or substantially octagonal frame-shaped second bonding metallization layer 10 electrically connected to the second metallization electrode 9 is applied to the lower surface of the projection 2a of the ceramic plate 2. . The second bonding metallization layer 10 functions as a bonding base metal layer for bonding the ceramic plate 2 to the ceramic base 1, and forms the second bonding metallization layer 10 and the first bonding metallization layer 8 with silver-based metal. The ceramic base 1 and the ceramic plate 2 are joined by brazing via a brazing material 11 such as copper brazing, and the first joining metallization layer 8 and the second joining metallization layer 10 are electrically connected. At the same time, a closed space is formed between the ceramic base 1 and the ceramic plate 2. At this time, the first metallized electrode 7 and the second metallized electrode 9 are opposed to each other with a closed space formed between the ceramic base 1 and the ceramic plate 2 interposed therebetween.
A predetermined capacitance is formed between them according to the area of the first metallized electrode 7 and the second metallized electrode 9 and the distance between the first metallized electrode 7 and the second metallized electrode 9. When an external pressure is applied to the upper surface of the ceramic plate 2, the ceramic plate 2 bends toward the ceramic base 1 according to the applied pressure, and the distance between the first metallized electrode 7 and the second metallized electrode 9 changes, As a result, the capacitance between the first metallized electrode 7 and the second metallized electrode 9 changes, so that it functions as a pressure-sensitive element that senses a change in external pressure as a change in capacitance. Then, the change in the capacitance is transmitted to the semiconductor element 3 housed in the concave portion 1a via the metallized wiring conductors 5a and 5b, and the magnitude of the external pressure is known by performing arithmetic processing on the semiconductor element 3. be able to. The second bonding metallization layer 10 is made of a metal powder such as tungsten, molybdenum, copper, silver or the like having a thickness of about 10 to 50 μm. The metallized paste obtained by adding and mixing the dispersing agent and the dispersant is printed and applied on a ceramic green sheet for the ceramic plate 2 by using a conventionally known screen printing method, and is fired together with the green ceramic molded body for the ceramic plate 2. By doing so, a predetermined pattern is formed on the lower surface of the protrusion 2a of the ceramic plate 2. Also, on the surface of the second bonding metallization layer 10,
In order to prevent the second bonding metallization layer 10 from being oxidized and corroded and to improve the bonding between the second bonding metallization layer 10 and the brazing material 11, the thickness is usually 1 to 10 μm.
A degree of nickel plating is deposited. Further, in the present invention, the thickness of the brazing material 11 for brazing the first bonding metallization layer 8 and the second bonding metallization layer 10 is 5 to 30 μm. And
That is important. As described above, since the thickness of the brazing material 11 for brazing the first bonding metallization layer 8 and the second bonding metallization layer 10 is reduced to 5 to 30 μm, the ceramic plate 2 is largely bent by external pressure. Even if,
The brazing material 11 does not undergo large plastic deformation. Therefore, according to the pressure detection device package of the present invention, it is possible to provide a pressure detection device capable of accurately detecting external pressure over a long period of time. If the thickness of the brazing material 11 for brazing the first bonding metallization layer 8 and the second bonding metallization layer 10 is less than 5 μm, the first bonding metallization layer 8 and the second bonding metallization layer There is a tendency that it is difficult to braze 10 and 10 through the brazing material 11 firmly and airtightly. On the other hand, if the thickness exceeds 30 μm, the brazing material will There is a great risk that large plastic deformation will occur in 11 and the external pressure cannot be detected accurately for a long time. Therefore, the thickness of the brazing material 11 for brazing the first bonding metallization layer 8 and the second bonding metallization layer 10 is specified in the range of 5 to 30 μm. In order to join the first bonding metallization layer 8 and the second bonding metallization layer 10 via the brazing material 11 having a thickness of 5 to 30 μm, the first bonding metallization layer 8 and the second bonding metallization layer A nickel plating layer having a thickness of about 1 to 10 μm is previously applied to the surface of the metallizing layer 10 for
Next, the ceramic base 1 and the ceramic plate 2 are pressed against each other so that the second bonding metallization layer 10 is in contact with the first bonding metallization layer, and the thickness is 10 to 200 μm.
Of silver-copper brazing is placed in such a manner as to come into contact with the outer peripheral portion of the first joining metallization layer and / or the second joining metallization layer, and these are placed in a reducing atmosphere.
A method is adopted in which the brazing material foil is melted by heating to a temperature of about 850 ° C., and the brazing material is penetrated between the first bonding metallization layer 8 and the second bonding metallization layer 10 to perform brazing. As described above, the first bonding metallization layer 8 and the second bonding metallization layer 10 are pressed against each other, and the brazing material foil is applied to the outer periphery of the first bonding metallization layer 8 and / or the second bonding metallization layer 10. The first metallizing layer 8 for first bonding and the second metallizing layer 10 for bonding are brazed by infiltrating the brazing material between the first metallizing layer 8 for the first bonding and the second metallizing layer 10 for the second bonding. The metallized layer 8 and the second metallized layer 10 for joining are formed by thin brazing material having a thickness of 5 to 30 μm.
11 can be brazed through. At this time, the first bonding metallization layer 8 and the second bonding metallization layer 10 may be such that their inner circumferences are located at least 0.05 mm outside the inner circumference of the projection 2a of the ceramic plate 2. preferable. Since the inner circumference of each of the first bonding metallization layer 8 and the second bonding metallization layer 10 is located at least 0.05 mm outside the inner circumference of the protruding portion 2a, the ceramic plate 2 is largely bent by external pressure. However, the stress generated due to the bending is the protrusion 2a
Is greatly concentrated near the root of the inner periphery of the brazing material, and is effectively prevented from acting largely on the inner peripheral edge of the brazing material 11. Therefore, it is possible to more effectively prevent the plastic deformation of the brazing material 11. Also, the first bonding metallization layer 8
And the second bonding metallization layer 10 with a brazing material such as silver-copper brazing
It is possible to effectively prevent the brazing material 11 from flowing out to the second metallized electrode 9 when brazing via the wire 11. The first bonding metallization layer 8 and the second bonding metallization layer 10 each have a protrusion 2
When the ceramic plate 2 is located less than 0.05 mm outside from the inner circumference of the a, the stress generated when the ceramic plate 2 is largely bent by the external pressure is greatly applied to the inner peripheral edge of the brazing material 11, and The risk of plastic deformation increases, and the stress is greatly applied to the corner between the inner peripheral side surface and the lower surface of the projection 2a, thereby increasing the risk of cracking or chipping of the ceramic plate 2. Become. At the same time, when the thickness of the projection 2a is as thin as 0.05 mm or less, for example, when brazing the first bonding metallization layer 8 and the second bonding metallization layer 10 via the brazing material 11, the brazing material 11 The risk of flowing out onto the second metallized electrode 9 becomes large. Therefore, it is preferable that the inner circumferences of the first bonding metallization layer 8 and the second bonding metallization layer 10 be located at least 0.05 mm outside the inner circumference of the protrusion 2a. As described above, according to the pressure detecting device package of the present invention, the first metallization for forming the capacitance is formed on the other main surface of the ceramic base 1 on which the semiconductor element 3 is mounted on one main surface. An electrode 7 is provided, and a ceramic plate 2 having a second metallized electrode 9 for capacitance formation facing the first metallized electrode 7 on an inner surface thereof is flexible so as to form a closed space between the ceramic plate 2 and the ceramic base 1. In such a state, the container accommodating the semiconductor element 3 and the pressure-sensitive element are integrated, and as a result, the pressure detection device can be downsized. Further, since the first metallized electrode 7 and the second metallized electrode 9 for forming the capacitance are connected to the semiconductor element 3 via the metallized wiring conductors 5a and 5b provided on the ceramic base 1, the first metallized electrode 7 and the second metallized electrode 9 are connected. And the second metallized electrode 9 can be connected to the semiconductor element 3 at a short distance, and as a result, unnecessary capacitance generated between these metallized wiring conductors 5a and 5b can be reduced to provide a highly sensitive pressure detecting device. Can be provided. Thus, according to the above-described package for a pressure detecting device, the semiconductor element 3 is mounted on the mounting portion 1b, and each electrode of the semiconductor element 3 is electrically connected to the metallized wiring conductor 5. By sealing the element 3, a compact and highly sensitive pressure detecting device is obtained. The present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the scope of the present invention. As described above, according to the pressure detecting device package of the present invention, a plurality of metallized wiring conductors are provided inside and on the surface, and a semiconductor element is mounted on one main surface. A first metallized electrode for forming a capacitance electrically connected to the metallized wiring conductor on the other main surface of the ceramic substrate having a mounting portion, and the other metallized wiring conductor surrounds the first metallized electrode. And a first metallizing layer electrically connected to the first metallizing layer, a frame-shaped protrusion is provided on the outer periphery of one main surface, and the first metallized layer is provided on one main surface surrounded by the protrusion. A second metallization electrode for forming a capacitance facing the metallization electrode and a main surface of the protrusion, which is electrically connected to the second metallization electrode; Since the ceramic plate having the second bonding metallized layer brazed to the soldering layer is bonded to the ceramic base in a flexible state so as to form an enclosed space between the ceramic base and the ceramic base, The pressure-sensitive element is formed integrally with the package that houses the element, and as a result, the pressure detection device can be reduced in size and the wiring connecting the electrode for pressure detection and the semiconductor element is shortened.
Unnecessary capacitance generated between these wirings can be reduced. Furthermore, since the thickness of the brazing material for brazing the first bonding metallization layer provided on the ceramic base and the second bonding metallization layer provided on the projections of the ceramic plate is as thin as 5 to 30 μm, the ceramic plate Even if external pressure is greatly applied over a long period of time, the amount of plastic deformation of the brazing material can be extremely small, and as a result, the pressure at which the external pressure can be accurately detected over a long period of time A detection device can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an example of an embodiment of a package for a pressure detecting device according to the present invention. FIG. 2 is a sectional view showing a conventional pressure detecting device. [Description of Signs] 1 ... Ceramic base 2 ... Ceramic plate 2a ... Protrusion 3 ... Semiconductor element 7 ... First metallized electrode 8 ... ..First metallized layer 9 for bonding and second metallized electrode 10

Claims (1)

Claims 1. A metallized wiring conductor having a plurality of metallized wiring conductors inside and on a surface thereof, a mounting portion on which a semiconductor element is mounted on one main surface, and one of the metallized wiring conductors on the other main surface. A first metallizing electrode for forming a capacitance electrically connected to the first metallizing electrode and a frame-shaped first metallizing metallization surrounding the first metallizing electrode and electrically connected to another one of the metallizing wiring conductors A ceramic substrate having a layer, and having a frame-shaped protrusion on the outer peripheral portion of one main surface, and forming a capacitance facing the first metallized electrode on one main surface surrounded by the protrusion. A frame-shaped second bonding metallization layer electrically connected to the second metallization electrode on the second metallization electrode and the projection, and brazed to the first bonding metallization layer via a brazing material. A pressure detecting device package comprising: a ceramic plate bonded to the ceramic base in a flexible state so as to form a sealed space between the ceramic base and the other main surface of the ceramic base; A package for a pressure detecting device, wherein a thickness of the brazing material for brazing the first bonding metallization layer and the second bonding metallization layer is 5 to 30 μm.