JP2002323394A - Package for pressure detector - Google Patents

Abstract

(57) [Problem] To provide a pressure detection device which is small, has high sensitivity, and can accurately detect external pressure. SOLUTION: An insulating base 1 having a mounting portion 1b on one main surface of which a semiconductor element 3 is mounted, and a plurality of insulating bases provided on the insulating base 1 and electrically connected to respective electrodes of the semiconductor element 3 are provided. The insulating plate 2 joined to the insulating base 1 in a flexible state so as to form a sealed space between the wiring conductor 5 and the other main surface of the insulating base 1, and the other main surface of the insulating base 1 A first electrode 7 for forming a capacitance, which is attached and electrically connected to one of the wiring conductors 5a, and another one of the wiring conductors 5 which is attached to the inner main surface of the insulating plate 2; And a second electrode 8 for forming a capacitance, which is electrically connected to the first and second wiring conductors 5a and 5b.
Are arranged so as not to vertically overlap the first electrode 7 and the second electrode 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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.

[0002]

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 provided on a wiring board 21 made of a ceramic material or a resin material.
And a semiconductor element 29 for arithmetic operation accommodated 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 with
An insulating plate 26 which is joined in a flexible state on the upper surface of the insulating substrate 24 so as to form a sealed space between the insulating substrate 24 and the other electrode 25 for forming a capacitance on the lower surface; Each of the electrodes 23 and 25 for forming a capacitance includes an external lead terminal 27 for electrically connecting the electrode to the outside, and each of the capacitances is formed by bending the insulating plate 26 in response to an external pressure. The capacitance formed between the forming electrodes 23 and 25 changes. An external pressure can be detected by subjecting the change in capacitance to arithmetic processing by the arithmetic semiconductor element 29.

[0003]

However, according to the 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 detecting device and the pressure detecting 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 having a mounting portion on one main surface on which a semiconductor element is mounted; and a plurality of wiring conductors disposed on and inside the insulating base and electrically connected to respective electrodes of the semiconductor element. 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 joined in a flexible state so as to form a sealed space with the central portion of the main surface; and an inner main surface of the insulating plate is attached to the first main surface so as to face the first electrode. A pressure detection device package including a second electrode for forming a capacitance electrically connected to another one has been proposed. According to the 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 the 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 is joined in a flexible state so as to form a sealed space with 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.

However, according to the pressure detecting device package proposed in Japanese Patent Application No. 2000-178618, the wiring conductor connected to the first electrode, the wiring conductor connected to the second electrode, the first electrode and the second electrode, No consideration is given to the capacitance formed between the first electrode and a part of the wiring conductor connected to the second electrode and the wiring conductor connected to the second electrode. It is arranged in an overlapping position, and an unnecessary capacitance is formed between these wiring conductors and the first electrode and the second electrode, so that there is a problem that the pressure detection sensitivity is reduced. I was

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 which is small, has high sensitivity, and can accurately detect an external pressure. It is in.

[0007]

A package for a pressure detecting device according to the present invention is provided on an insulating base having a mounting portion on one side of which a semiconductor element is mounted, and on the surface and inside of the insulating base. A plurality of wiring conductors to which each electrode of the semiconductor element is electrically connected; and an insulating plate joined to the insulating base in a flexible state so as to form a sealed space between the other main surface of the insulating base. A first electrode for forming a capacitance, which is attached to the other main surface of the insulating base in the enclosed space and is electrically connected to one of the wiring conductors; and a first electrode on the inner main surface of the insulating plate. And a second electrode for forming a capacitance, which is attached so as to face the first electrode and is electrically connected to another one of the wiring conductors. Wiring conductor and the wiring conductor connected to the second electrode, the first electrode and And it is characterized in that it is arranged so as not to overlap vertically with the second electrode.

According to the pressure detecting device package of the present invention, the wiring conductor connected to the first electrode and the wiring conductor connected to the second electrode are arranged so as not to vertically overlap the first electrode and the second electrode. As a result, the formation of unnecessary capacitance between these wiring conductors and the first and second electrodes can be effectively prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 pressure detection device package according to the present invention.
1 is an insulating base, 2 is an insulating plate, and 3 is a semiconductor element.

An insulating base 1 has a semiconductor element 3
Aluminum nitride-based sintered body having a concave portion 1a for accommodating therein and a substantially circular concave portion 1c for forming a substantially disk-shaped closed space between the upper surface and an insulating plate 2 described later. A laminate made of a ceramic material such as an aluminum sintered body, a mullite sintered body, or a glass-ceramic. For example, in the case of an aluminum oxide sintered body, aluminum oxide, silicon oxide, magnesium oxide, oxide An appropriate organic binder, a solvent, a plasticizer, and a dispersant are added to a ceramic raw material powder such as calcium and mixed to form a slurry, which is formed into a sheet by employing a well-known doctor blade method. Ceramic green sheets, and then these ceramic green sheets are properly punched, laminated and cut. It is manufactured by firing at a temperature of about 1600 ° C. with a ceramic green sheet for the insulating plate 2 with obtaining raw ceramic formed body later this green ceramic body insulating substrate 1 by performing.

The insulating substrate 1 has a recess 1a formed in the center of the lower surface, and the center of the bottom surface serves as a mounting portion 1b on which the semiconductor element 3 is mounted.
And the semiconductor element 3 is sealed by 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 into the concave portion 1a. However, the semiconductor element 3 is provided with a lid made of metal or ceramic on the lower surface of the insulating base 1 in the concave portion 1a. It may be sealed by joining so as to close.

A plurality of wiring conductors 5 connected to the respective electrodes of the semiconductor element 3 are led out from the mounting portion 1b, and the wiring conductor 5 and the respective electrodes of the semiconductor element 3 are electrically connected to each other by a bonding wire 6 or the like. By joining via the connection means, 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 wiring conductors 5 are connected via bonding wires 6, but the electrodes of the semiconductor element 3 and the wiring conductors 5 are connected to other types of electrical connection means such as solder bumps. May be connected.

The 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 electrode 7 and a second electrode 8, which will be described later. 1 and the other part is the first electrode 7
-It is electrically connected to the second electrode 8. After electrically connecting the electrodes of the semiconductor element 3 to these wiring conductors 5 via a conductive bonding material and sealing the semiconductor element 3 with a resin sealing material 4, the insulating base of the wiring conductor 5 is formed. (1) 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 to the wiring conductor of the external electric circuit board via a conductive bonding material such as solder. Becomes

The wiring conductor 5 is made of a metal powder of tungsten, molybdenum, copper, silver or the like.
A metallized paste obtained by adding a suitable organic binder, a solvent, a plasticizer, a dispersant, etc. to a metal powder such as tungsten is mixed with a ceramic green sheet for the insulating substrate 1 by using a conventionally known screen printing method. The pattern is printed and applied, and is fired together with the green ceramic molded body for the insulating substrate 1, whereby a predetermined pattern is formed inside and on the surface of the insulating substrate 1. In order to prevent the wiring conductor 5 from being oxidized and corroded, and to improve the bonding between the wiring conductor 5 and the bonding wire 6 or the conductive bonding material, the exposed surface of the wiring conductor 5 is usually formed on the exposed surface. If the thickness of the nickel plating layer is
A gold plating layer of about 0.1 to 3 μm is sequentially applied.

A first electrode 7 for forming a capacitance is attached to the bottom of the concave portion 1c formed at the center of the upper surface of the insulating base 1. The first electrode 7 is for forming a capacitance for a pressure-sensitive element together with a second electrode 8 of the insulating plate 2 described later. The first electrode 7 has a wiring conductor 5
When the electrode of the semiconductor element 3 is connected to the wiring conductor 5a via an electrical connection means such as a bonding wire 6, the electrode of the semiconductor element 3 and the first electrode 7 are electrically connected. The connection is made.

The first electrode 7 is made of metal powder of tungsten, molybdenum, copper, silver, or the like.
A metallized paste obtained by adding a suitable organic binder, a solvent, a plasticizer, and a dispersant to a metal powder such as tungsten is mixed with the insulating substrate 1 by using a conventionally known screen printing method.
A ceramic green sheet for printing is applied and baked together with a green ceramic molded body for the insulating substrate 1 to form a predetermined pattern at the center of the upper surface of the insulating substrate 1.

A substantially flat insulating plate 2 covering the concave portion 1c is formed on the upper surface of the insulating base 1 so as to form a substantially disc-shaped closed space between the insulating base 1 and the upper surface of the insulating base 1. And are sintered and integrated with the insulating base 1 and joined. Insulating plate 2
Is a flat plate of about 0.01 to 5 mm in thickness of approximately square or approximately octagonal or circular made of a ceramic material such as aluminum oxide sintered body, aluminum nitride sintered body, mullite sintered body, glass-ceramics, It functions as a so-called pressure detecting diaphragm that bends toward the insulating base 1 in response to external pressure.

When the insulating 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 for the insulating plate 2 is obtained by adding and mixing an agent and a dispersant to form a slurry and forming the slurry into a sheet shape by employing a conventionally known doctor blade method. The sheet is subjected to an appropriate punching or cutting process, and is laminated on a green ceramic molded body for the insulating substrate 1, and is fired together with the green ceramic molded body for the insulating substrate 1 at a temperature of about 1600 ° C. It is manufactured by sintering and integration.

If the thickness of the insulating plate 2 is less than 0.01 mm, the mechanical strength of the insulating plate 2 is small, so that there is a great risk that the insulating plate 2 will be broken when a large external pressure is applied thereto. On the other hand, if it 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 insulating plate 2 is preferably in the range of 0.01 to 5 mm.

A substantially circular second electrode 8 for forming a capacitance is attached to the lower surface of the insulating plate 2 so as to face the first electrode 7. The second electrode 8 functions as an electrode for forming a capacitance for the pressure-sensitive element together with the first electrode 7 described above. The other one 5b of the wiring conductor 5 is connected to the second electrode 8, so that the wiring conductor 5
When the electrode of the semiconductor element 3 is connected to the electrode b via an electrical connection means such as a bonding wire 6, the electrode of the semiconductor element 3 and the second electrode 8 are electrically connected.

At this time, the first electrode 7 and the second electrode 8
They face each other with a closed space formed between the insulating base 1 and the insulating plate 2 therebetween, between which the areas of the first electrode 7 and the second electrode 8 and the first electrode 7 and the second electrode A predetermined capacitance is formed in accordance with the distance from the capacitor 8. And the insulating plate 2
When an external pressure is applied to the upper surface of the substrate, the insulating plate 2 bends toward the insulating base 1 in accordance with the pressure, and the distance between the first electrode 7 and the second electrode 8 changes. Since the capacitance with the second electrode 8 changes, it functions as a pressure-sensitive element that detects 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 recess 1a via the wiring conductors 5a and 5b,
The magnitude of the external pressure can be known by performing an arithmetic process on this in the semiconductor element 3.

The second electrode 8 is made of metallized metal powder such as tungsten, molybdenum, copper, silver, etc., and is obtained by adding a suitable organic binder, solvent, plasticizer and dispersant to metal powder such as tungsten. The metallized paste is applied by printing to a ceramic green sheet for the insulating plate 2 by using a conventionally known screen printing method, and this is applied to the insulating plate 2.
By firing together with the ceramic green sheet for use, a predetermined shape facing the first electrode 7 is formed on the lower surface of the insulating plate 2.

In the present invention, the wiring conductor 5a connected to the first electrode 7 and the wiring conductor 5b connected to the second electrode 8 do not vertically overlap the first electrode 7 and the second electrode 8. It is important to do that. Thus, the wiring conductor 5a connected to the first electrode 7
And the wiring conductor 5b connected to the second electrode 8 is disposed so as not to overlap the first electrode 7 and the second electrode 8 vertically, so that these wiring conductors 5a and 5b and the first electrode 7 The formation of unnecessary capacitance between the second electrode 8 and the second electrode 8 can be effectively prevented.

As described above, according to the pressure detecting device package of the present invention, the first electrode 7 for forming a capacitance is formed on the other main surface of the insulating base 1 on which the semiconductor element 3 is mounted on one main surface. And an insulating plate 2 having a second electrode 8 for forming a capacitance opposed to the first electrode 7 on the inner surface is formed so as to form a closed space between the insulating plate 2 and the other main surface of the insulating base 1. Since it is joined to the insulating base 1 in a flexible state, the container accommodating the semiconductor element 3 and the pressure-sensitive element are integrated, and as a result, the pressure detecting device can be downsized. Also,
The wiring conductors 5a and 5b disposed on the insulating base 1 are arranged so that the first electrode 7 and the second electrode 8 for forming the capacitance do not vertically overlap with the first electrode 7 and the second electrode 8. Since the first electrode 7 and the second electrode 8 can be connected to the semiconductor element 3 over a short distance, the first electrode 7 and the second electrode 8 can be connected between the wiring conductors 5a and 5b and between the wiring conductors 5a and 5b. An unnecessary capacitance generated between the first electrode 7 and the second electrode 8 can be reduced to provide a highly sensitive pressure detection device.

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 and the wiring conductor 5 are electrically connected. By sealing 3, a pressure detection device which is small in size, has high sensitivity, and can accurately detect external pressure is provided.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. In one example, the insulating base 1 and the insulating plate 2 are joined by sintering and integration, but the insulating base 1 and the insulating plate 2 may be joined by brazing.

[0027]

As described above, according to the pressure detecting device package of the present invention, the first main surface of the insulating base on which the semiconductor element is mounted is provided with the second main surface for forming the capacitance. One electrode is provided, and an insulating plate having a second electrode for forming a capacitance opposed to the first electrode is placed in a flexible state so as to form a closed space between the insulating plate and the other main surface of the insulating base. As a result, the container for accommodating the semiconductor element and the pressure-sensitive element are integrated, and as a result, the size of the pressure detecting device can be reduced. Further, since the wiring conductor connected to the first electrode and the wiring conductor connected to the second electrode are arranged so as not to vertically overlap the first electrode and the second electrode, these wiring conductors and the first Provided is a pressure detection device that can effectively prevent an unnecessary capacitance from being formed between an electrode and a second electrode, and as a result, can accurately and sensitively detect an external pressure. can do.

[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 cross-sectional view showing a conventional pressure detecting device.

[Explanation of symbols]

 1 ... Insulating base 1b ... Mounting section 2 ... Insulating plate 3 ... Semiconductor element 5 ... Wiring conductor 5a ... Connected to the first electrode ... Wiring conductors 55 b connected to the second electrode 55... First electrode 8... Second electrode

Claims (1)

[Claims] 1. An insulating base having a mounting portion on one main surface on which a semiconductor element is mounted, and a plurality of insulating bases disposed on and inside the insulating base and electrically connected to respective electrodes of the semiconductor element. An insulating plate joined to the insulating base in a flexible state so as to form a sealed space between the wiring conductor and the other main surface of the insulating base; and the other main surface in the sealed space. A first electrode for forming a capacitance electrically connected to one of the wiring conductors, and is attached to an inner main surface of the insulating plate so as to face the first electrode, A package for a pressure detecting device comprising: a second electrode for forming a capacitance electrically connected to another one of the wiring conductors, wherein the wiring conductor connected to the first electrode And the wiring conductor connected to the second electrode includes the first electrode and the second electrode. A package for a pressure detecting device, wherein the package is arranged so as not to overlap with a pole vertically.