JP2006084337A - Semiconductor pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor pressure sensor having inexpensive mounting cost, and capable of surface mounting corresponding to diversification of a mounting form. <P>SOLUTION: Conductive members 2a-2d are arranged on corner parts of an outer case 1. Each conductive member 2a-2d is arranged in the glass adhesion state (unillustrated) with a form penetrating the outer case 1 in the state where a partial surface of each conductive member 2a-2d is exposed from the inside to an external bottom surface part and an external side surface part. The partial exposure part of each conductive member 2a-2d is arranged so as to be approximately flush with the external side surface and the external bottom surface of the outer case 1. The upper end surface of each conductive member 2a-2d has a form thrusting greatly toward the inside of the outer case 1 and has a constitution where a bonding wire is to be connected. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor pressure sensor.

  Conventionally, there are pressure sensors used in a wide range of fields such as wristwatches, home appliances, automobiles, airplanes and the like. As one type, there is a semiconductor pressure sensor that forms piezoresistors on the upper surface of a silicon crystal plate and detects pressure using these piezoresistors as a pressure-sensitive portion. This semiconductor pressure sensor is advantageous in that it can be easily manufactured because the semiconductor manufacturing process technology can be used as it is, and the structure can be simplified. In addition, since the voltage sensitivity is extremely large and can be easily amplified, an accurate pressure sensor can be obtained, so that it is widely used in various fields.

  FIG. 3 is a perspective view showing a conventional semiconductor pressure sensor, and FIG. 4 is a diagonal sectional view of FIG. Reference numeral 3 denotes a semiconductor pressure sensor chip made of a silicon crystal substrate (hereinafter simply referred to as a chip). The chip 3 has a pressure-receiving surface as an upper surface and is fixed to a predetermined position on the bottom of the outer case 11 with an adhesive (not shown). Reference numerals 12a, 12b, 12c, and 12d denote metal pins, which are embedded in a form penetrating the outer case 11, and end portions of the metal pins 12a, 12b, 12c, and 12d located inside the outer case 11 and the chip 3. The bonding pads 6 provided above are connected to each other by bonding wires 4. The glass adhesive 15 is for bonding and fixing the metal pins 12a, 12b, 12c, and 12d. The ends of the metal pins 12a, 12b, 12c, and 12d projecting toward the outer bottom surface of the outer case 11 are mounted in a configuration in which they are inserted into through holes of a circuit board (not shown) and connected by soldering. is there.

  The outer case 11 is preferably formed by injection molding a resin such as PPS (polyphenylene sulfide), PPO (polyphenylene oxide), PBT (polybutylene terephthalate), PET (polyethylene terephthalate), or a ceramic material. It has been.

A gel-like potting resin (not shown) is filled in the outer case 11 so as to cover the pressure receiving surface of the chip 3 and the bonding wire 4 to constitute a semiconductor pressure sensor. With this configuration, when pressure is applied to the chip 3 through the gel-like potting resin, the resistance value of the piezoresistor changes according to the pressure, and the pressure is measured based on this resistance value (for example, Patent Document 1). reference).
Japanese Patent Laid-Open No. 5-40068

  In the conventional semiconductor pressure sensor, the metal pins 12a, 12b, 12c, and 12d are used as means for connecting to the external circuit board. Therefore, through holes such as pin insertion holes are formed on the external circuit board side. It becomes essential and increases the implementation cost. Further, in the soldering inspection process, the back surface opposite to the semiconductor pressure sensor mounting surface is inspected, which increases the number of steps and increases the cost in the subsequent process. In addition, the conventional configuration is difficult to cope with surface mounting, which hinders automation, resulting in an increase in manufacturing cost. In addition, mounting forms have been diversified, and not only soldering only on the back side of the semiconductor pressure sensor, but also a configuration that enables solder mounting from a plurality of directions such as soldering from the side surface is desired. .

  In view of the above problems, an object of the present invention is to provide a semiconductor pressure sensor that can be mounted on the surface at a low mounting cost and can be used in a variety of mounting forms.

  An outer case having a concave cross-section with one end face as an opening; a conductive member embedded in the outer case; a semiconductor pressure sensor chip that detects pressure and generates an electrical signal in accordance with a detection level; A wire for conducting the semiconductor pressure sensor chip and the conductive member, and the pressure sensor surface of the semiconductor pressure sensor chip and the opening of the outer case are aligned with each other inside the outer case. A semiconductor pressure sensor mounted and filled with a protective member in the outer case, a part of the conductive member is exposed on an outer bottom surface and an outer side surface of the outer case, and further on the inner side of the outer case The semiconductor pressure sensor is formed by embedding the conductive member so that the connection end face with the wire is exposed.

  The wire connecting end surface of the conductive member is parallel to the pressure receiving surface of the semiconductor chip, and is a semiconductor pressure sensor in a form positioned in the bottom direction from the opening end surface of the outer case.

  Since a part of the conductive member is exposed on the outer bottom surface and the outer side surface of the outer case, surface mounting becomes easy. In addition, since a part of the conductive member is exposed in both directions of the outer bottom surface and the outer side surface, solder mounting can be performed from both directions, which can cope with diversification of mounting forms.

An outer case having a concave cross-section with one end face as an opening; a conductive member embedded in the outer case; a semiconductor pressure sensor chip that detects pressure and generates an electrical signal according to a detection level; A wire for conducting the semiconductor pressure sensor chip and the conductive member, and the pressure sensor surface of the semiconductor pressure sensor chip and the opening of the outer case are aligned with each other inside the outer case. In the semiconductor pressure sensor mounted and filled with a protective member in the outer case, a part of the conductive member is exposed on the outer bottom surface and the outer side surface of the outer case, and further, the wire is disposed on the inner side of the outer case. The semiconductor pressure sensor is configured to be embedded so that the connection end face is exposed.
Hereinafter, embodiments of the semiconductor pressure sensor of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic perspective view showing the structure of a semiconductor pressure sensor according to the present invention, and FIG. 2 is a diagonal sectional view thereof. In FIG. 1, reference numeral 1 denotes an outer case made of ceramic and shaped like a square. Conductive members 2 a to 2 d are embedded near the corners of the outer case 1. In a form penetrating the outer case 1, glass bonding (explained in FIG. 2) is arranged so that a part of the conductive members 2 a to 2 d appears on the outer bottom surface and the outer side surface from the inside. The partially exposed portions of the conductive members 2a to 2d are arranged so as to be substantially flush with the outer bottom surface and the outer side surface of the outer case 1. The upper end surfaces of the conductive members 2a to 2d are protruded toward the inside of the outer case 1, and the bonding wire 4 is connected thereto. Here, since the bonding wire 4 uses a gold wire, at least the upper end surfaces (connection end surfaces with the bonding wire 4) of the conductive members 2a to 2d are surface-treated by gold plating in order to obtain the connection strength. . Further, a semiconductor pressure sensor chip 3 (hereinafter simply referred to as a chip) is fixedly disposed at the center of the square-shaped outer case 1 with an adhesive so that the pressure receiving surface (detection unit) faces the opening direction of the outer case 1 ( Adhesive is not shown). In addition to the detecting portion, a bonding pad 6 is provided on the upper end surface of the chip 3. The conductive members 2 a to 2 d described above are connected to each other by the bonding wire 4, and are electrically connected to the outside of the outer case 1. As described above, after various internal structures of the rectangular container-like outer case 1 are arranged in a predetermined manner, a gel-like potting resin (not shown), which is a general technique, is filled to complete the semiconductor pressure sensor. According to the said structure, since the one part exposed part of the electrically-conductive members 2a-2d is arrange | positioned so that it may become the substantially same surface as the outer case 1 outer peripheral surface, it becomes a structure which surface mounting is easy. In addition, since the conductive members 2a to 2d are configured to expose a part thereof in both directions of the outer bottom surface portion and the outer side surface portion of the outer case 1, the back surface (exposed portion of the outer bottom surface portion) in mounting the semiconductor pressure sensor. In addition to solder mounting on the side surface (exposed portion of the external side surface portion), it is possible to deal with various mounting forms. In addition, according to this structure, since an inspection of a soldering state can be performed from a mounting surface direction, an inspection process can be simplified.

  In FIG. 2, the conductive members 2 a to 2 d arranged so as to be substantially flush with the outer side surface portion and the outer bottom surface portion of the outer case 1 are fixed by the glass adhesive 5. Here, there is no problem even if the glass adhesive 5 flows into the respective component gaps between the outer case 1 and the conductive members 2a to 2d to be bonded, but the glass adhesive 5 is at a predetermined position where the chip 3 is bonded and fixed. It is not preferable to flow in. Therefore, in FIG. 2, the predetermined position of the chip 3 is set higher than the surface to which the glass adhesive material 5 is to be fixed (configuration in which a step portion is provided). The shape is not limited to this shape as long as the shape prevents the glass adhesive material 5 from flowing into a predetermined position where the chip 3 is bonded and fixed. Further, the connection end surface of the pressure receiving surface (detection unit) of the chip 3 and the bonding wires 4 of the conductive members 2a to 2d are parallel, the height of the bonding pad 6 positioned on the upper end surface of the chip 3, and the conductive members 2a to 2d. The connection end face with the bonding wire 4 has a generally matched configuration. Thereby, the connection of the bonding wire 4 becomes easy and the bonding accuracy is improved. In addition, even if the bonding wire 4 can be protected with a potting resin (not shown) by providing the side wall (over the entire circumference) of the outer case 1 to a position slightly higher than the loop height of the bonding wire 4, the potting resin Does not flow out of the outer case 1.

  As described above, the embodiment of the present invention has been described. However, the ceramic rectangular outer case 1 may be an insulating member and may be formed of a resin material, and the conductive members 2a to 2d are fixed. The means to do is not only glass bonding but also epoxy bonding. Also, the bonding wire 4 can be an aluminum wire if the bonding method is changed. When an aluminum wire is used, gold plating on at least the upper end surfaces (surfaces to which the bonding wire 4 is connected) of the conductive members 2a to 2d becomes unnecessary. Thus, it goes without saying that many modifications can be implemented without departing from the spirit of the present invention.

  Next, another embodiment will be described with reference to FIGS. FIG. 5 is a schematic perspective view showing the structure of a semiconductor pressure sensor according to the present invention, and FIG. 6 is a diagonal sectional view thereof.

  In FIG. 5, a rectangular prism-shaped outer case 21 made of ceramic, and prismatic conductive members 22a to 22d are arranged at the corners. In a form penetrating the outer case 21, it is disposed by being glass-bonded (explained in FIG. 6) so that a part of the prismatic conductive members 22a to 22d is exposed from the inside to the outer bottom surface portion and the outer side surface portion, The ridge line portions of the prismatic conductive members 22a to 22d are appropriately subjected to the curvature process appropriately so as to coincide with the curvature of the corner portion of the outer case 21. The upper end surfaces of the prismatic conductive members 22a to 22d are protruded toward the inside of the outer case 21, and the bonding wire 4 is connected to be used as in the first embodiment.

  In FIG. 6, the conductive members 22 a to 22 d disposed so as to be substantially flush with the outer side surface and the outer bottom surface of the outer case 21 are fixed by the glass adhesive 25. With the above-described configuration, the partially exposed portions of the conductive members 22a to 22d are arranged so as to be substantially flush with the outer peripheral surface of the outer case 1, so that surface mounting is easy. In addition, since the conductive members 22a to 22d are configured to expose a part thereof in both directions of the outer bottom surface portion and the outer side surface portion of the outer case 1, both directions can be used as mounting surfaces, and the mounting forms can be diversified. Yes.

  Furthermore, another embodiment will be described with reference to FIGS. 7 is a schematic perspective view showing the structure of a semiconductor pressure sensor according to the present invention, and FIG. 8 is a cross-sectional view of FIG.

In FIG. 7, prismatic conductive members 32a to 32d are arranged in the central part of the ceramic rectangular outer case 31 and the portion corresponding to the square side. In a form penetrating the outer case 31, it is disposed by being glass-bonded (explained in FIG. 8) so that a part of the prismatic conductive members 32a to 32d is exposed from the inside to the outer bottom surface portion and the outer side surface portion. Yes. The upper end surfaces of the prismatic conductive members 32a to 32d are protruded toward the inside of the outer case 31, and the bonding wire 4 is connected and used as in the first embodiment.

  In FIG. 8, prismatic conductive members 32 a to 32 d arranged so as to be substantially flush with the outer bottom surface portion and the outer side surface portion of the outer case 31 are fixed by the glass adhesive 35. With the above-described configuration, the partially exposed portions of the conductive members 32a to 32d are arranged so as to be substantially flush with the outer peripheral surface of the outer case 31, so that surface mounting is easy. In addition, since the conductive members 32a to 32d are configured to expose a part thereof in both directions of the outer bottom surface portion and the outer side surface portion of the outer case 31, both directions can be used as mounting surfaces, and the mounting form can be diversified. Yes. The conductive members 32a to 32d can be appropriately set in consideration of the positional relationship with the bonding pad 6 and the mounting position on the external circuit board.

The schematic perspective view which shows the structure of the semiconductor pressure sensor concerning this invention. (Example 1) FIG. 2 is a diagonal cross-sectional view of FIG. 1. (Example 1) The schematic perspective view of the conventional semiconductor pressure sensor. FIG. 4 is a diagonal cross-sectional view of FIG. 3. The schematic perspective view which shows the structure of the semiconductor pressure sensor concerning this invention. (Example 2) FIG. 6 is a diagonal cross-sectional view of FIG. 5. (Example 2) The schematic perspective view which shows the structure of the semiconductor pressure sensor concerning this invention. Example 3 Sectional drawing of FIG. Example 3

Explanation of symbols

1 outer case 2a conductive member 2b conductive member 2c conductive member 2d conductive member 3 semiconductor pressure sensor chip 4 bonding wire 5 glass adhesive 6 bonding pad 11 outer case 12a metal pin 12b metal pin 12c metal pin 12d metal pin 15 glass adhesive 21 Outer case 22a Conductive member 22b Conductive member 22c Conductive member 22d Conductive member 25 Glass adhesive 31 Outer case 32a Conductive member 32b Conductive member 32c Conductive member 32d Conductive member 35 Glass adhesive

Claims (2)

An outer case having a concave cross section with one end face as an opening;
A conductive member embedded in the outer case;
A semiconductor pressure sensor chip that detects pressure and generates an electrical signal according to the detection level; and
A wire for conducting the semiconductor pressure sensor chip and the conductive member;
The semiconductor pressure sensor chip is mounted inside the outer case in a direction in which the pressure receiving surface of the semiconductor pressure sensor chip and the opening of the outer case match.
In the semiconductor pressure sensor formed by filling a protective member in the outer case,
A part of the conductive member is exposed on the outer bottom surface and the outer side surface of the outer case, and the conductive member is embedded inside the outer case so that a connection end surface with the wire is exposed. A semiconductor pressure sensor.   2. The semiconductor pressure sensor according to claim 1, wherein a wire connection end surface of the conductive member is parallel to a pressure receiving surface of the semiconductor chip and is positioned in a bottom direction from an end surface of the opening of the outer case.

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