JPH0755614A - Package structure for pressure sensor - Google Patents

Abstract

PURPOSE:To realize a package structure for pressure sensor in which the continuity between a pressure sensor and a pressure measuring medium is ensured, and the reduction in pressure measuring function by the penetration of foreign matter from a communicating hole can be prevented. CONSTITUTION:A base seat glass 14 is provided on the center part of a stem 11 having an input and output terminal group 12 planted thereon. A reversed U-shaped pressure detecting element 13 is connected onto the base seat glass 14, and a vacuum chamber 15 is formed between them. A bonding wire 16 is connected between the input and output terminal 12 and the pressure detecting element 13. A can case 17 is fitted thereon. A pair of communicating holes 18, 19 are provided symmetrically to the center on the surface excluding the opposed part to the pressure detecting element 13 of the can case 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention relates to a semiconductor pressure sensor,
In particular, the present invention relates to a pressure sensor package structure mounted on a printed circuit board.

[0002]

2. Description of the Related Art FIG. 2 shows an example of a conventional structure of a pressure sensor of this type.
6] Reprint (1983) p. 6 ". The figure is a cross-sectional view of a main part showing a pressure sensor, in which 1 is a stem,
Reference numeral 2 is an input / output terminal, 3 is a semiconductor pressure detecting element portion for detecting the pressure of a measurement medium (for example, air), 4 is a base glass, 5 is a vacuum chamber, 6 is a portion between the pressure detecting element portion 3 and the input / output terminal 2. Bonding wires are connected, 7 is a can case that covers the above-mentioned components, and 8 is a communication hole provided in the center of the can case 7 for communicating with a pressure measuring medium. The conventional pressure sensor configured as described above has the communication hole 8
The pressure of the measuring medium introduced from the above is received by, for example, a silicon single crystal diaphragm used for the pressure receiving surface of the pressure detecting element 3,
It utilizes the piezoresistance effect that the diffusion resistance formed as a diffusion layer directly on the surface changes.

[0003]

However, in the pressure sensor device having the above structure, the communication hole 8 for communicating with the pressure measuring medium is provided at the center of the can case 7, and only one hole is provided. If the communication hole 8 is clogged with foreign matter or dust in the measurement medium adheres to it, pressure cannot be detected accurately, and problems such as unstable output or no output occur, and reliability is reduced. There was a problem that it was missing.

Further, since the communication hole 8 is located in the can case 7 in a portion facing the pressure detecting element portion 3, a hard object having a diameter smaller than that of the communication hole 8 (for example, an input / output terminal of the pressure sensor).
There is also a problem that the pressure sensing element 3 and the bonding wire 6 will be damaged if the intruder enters.

In order to eliminate the problems of the prior art, the present invention arranges a plurality of communication holes avoiding the portion directly above the pressure sensing element so as to have high reliability. It is intended to provide a pressure sensor.

[0006]

The structure of the present invention for achieving the above object will be described with reference to FIG. 1 corresponding to an embodiment. The present invention has a communication hole for a pressure measuring medium in a package. A pressure sensor having two communication holes 18, 1
9 is provided.

Further, the two communication holes 18 and 19 are provided at positions not facing the pressure detecting element 13 in the can case 17, respectively.

Further, the present invention is characterized in that a pair of communication holes 18 and 19 are provided on a diagonal line of the can case 17 at positions symmetrical with respect to the center thereof.

[0009]

According to the present invention in which the pressure sensor is constructed as described above, the number of communication holes with the measuring medium is two, so that even if one of the holes (18) is clogged with foreign matter, the other is connected. The hole (19) operates normally to enable accurate pressure detection of the measurement medium.

Further, since the two communication holes 18 and 19 are provided in a portion of the can case 17 that does not face the pressure detecting element portion 13, the communication holes 18 and 19 are made of hard material having a smaller diameter ( For example, the input / output terminal lead 1 of the pressure sensor
Even if 2) accidentally enters, the pressure detecting element 13 and the bonding wire 16 will not be damaged.

Furthermore, since the two communication holes 18 and 19 of the preceding paragraph are arranged symmetrically with respect to the center of the can case 11, they can be attached to the main body without considering the orientation of the can case.
Since it can be mounted on the printed circuit board without being aligned in the direction, workability is improved.

Therefore, the above problems are eliminated.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. 1A and 1B are structural views of a package for a pressure sensor showing an embodiment of the present invention, in which FIG. 1A is a side sectional view of a main part thereof, and FIG. In the figure, 1
Reference numeral 1 is a stem, 12 is an input / output terminal, and 13 is a semiconductor pressure detecting element section for converting pressure into an electric signal, which has the same structure as the pressure detecting element section 3 described in FIG. Detect pressure. Reference numeral 15 is a vacuum chamber formed between the pressure detection element portion 13 and the base glass 14, and 16 is a bonding wire connecting the semiconductor pressure detection element portion 13 and the input / output terminal 12. The above components are covered by a can case 17, and a pair of communication holes 18 and 19 to the measuring medium are provided at symmetrical positions on the diagonal line of the can case 17 and at positions displaced from the center. See FIG. 1B]. In this way, the pair of communication holes 18, 19
Since any one of the communication holes 18 (or 19) is clogged, since the pressure can be introduced into the other communication hole 19 (or 18), the pressure can be accurately detected. Further, the communication holes 18 and 19 are provided in the can case 17.
Since it is provided at a position deviated from the central portion of the pressure sensing element portion 13, that is, at a position avoiding the facing portion directly above the pressure detection element portion 13, the communication hole 1
Even if a hard object having a diameter smaller than 8 or 19 (for example, the input / output terminal lead 12 of the pressure sensor) enters, the pressure detection element unit 1
3 and the bonding wire 16 will not be damaged.
Further, since the communication holes 18 and 19 are arranged symmetrically with respect to the center, the mounting directionality of the can case 17 can be eliminated, and the mounting direction on the printed circuit board does not need to be aligned. Workability is improved because it can be implemented. In the above embodiment, the can case is used as a component member of the package, and the case of the two communication holes is described. However, the component member can be applied to a plastic package, a DIP or SIP type package, and Two or more communication holes may be provided.

[0014]

As described in detail above, according to the present invention, the following effects can be obtained. Since the communication holes between the pressure sensor and the pressure measuring medium are arranged at symmetrical positions deviated from the center of the pressure sensor package,
Even if one communication hole is clogged, communication with the pressure measuring medium is maintained in the other communication hole, and reliability is improved.

Further, since the communication hole of the package is arranged so as to avoid the portion facing the pressure detecting element, even if a foreign matter having a small diameter enters through the communication hole, it does not hit the internal pressure detecting element or the bonding wire. Therefore, these damages can be prevented.

Further, since the pair of communication holes are arranged symmetrically with respect to the center of the can case, the mounting directionality of the can case is eliminated, and the mounting workability at the time of board mounting is improved.

[Brief description of drawings]

FIG. 1 is a side sectional view and an external perspective view showing an embodiment of the present invention.

FIG. 2 is a side sectional view showing a conventional configuration example.

[Explanation of symbols]

 11 Stem 12 Input / Output Terminal 13 Pressure Sensing Element Section 14 Pedestal Glass 15 Vacuum Chamber 16 Bonding Wire 17 Can Case 18 Communication Hole 19 Communication Hole

Claims (3)

[Claims] 1. A pressure sensor package structure comprising a plurality of communication holes, wherein the package has a communication hole for communicating with a pressure measuring medium. 2. The communication hole is provided on the package surface excluding the facing portion of the pressure sensing element portion.
Package structure for the pressure sensor described. 3. The package structure for a pressure sensor according to claim 2, wherein the pair of communication holes are arranged symmetrically with respect to the center of the package.