JPH11326085A - Sensor - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To significantly reduce the overall shape of a sensor, reduce the mounting area, and to manufacture the sensor at low cost. SOLUTION: A package 1 serving also as a wiring board is provided, in which a sensor chip 2 is mounted, and wiring portions 8 and 10 for external connection are formed from inside to outside of the package 1. One ends of the wiring portions 8 and 10 are electrically connected to the sensor chip 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure sensor, an acceleration sensor, a speed sensor, an impact sensor, and other similar sensors.

[0002]

2. Description of the Related Art Conventional sensors, for example, pressure sensors, include:
There are those shown in FIGS. 14 and 15.

FIG. 14 is an external perspective view of the pressure sensor, and FIG. 15 is a side sectional view thereof. FIG. 14 shows a state where the cap of the package is removed.

The sensor has a plastic package 100, a sensor chip 110, and a lead frame 114.

[0005] A package 100 includes a box-shaped case body 102 having a shallow bottom with an open top.
2 and a flat plate-shaped cap 112 which is put on the upper part of the cap 2.

In the case body 102, a cylindrical pressure introducing portion 102b is integrally formed at the center of a bottom portion 102a by resin molding, and a sensor chip 110 is mounted at the center on the inner surface of the bottom portion 102a to form a pressure introducing portion. Part 102b
Facing the inner hole 102c. The case body 102
An air opening 102e is formed in a part of the peripheral wall portion 102d because the sensor chip 110 needs to detect a pressure difference from the atmosphere.

The lead frames 114 are provided on the left and right sides of the case main body 102 so as to face each other. Each lead frame 114 has a rectangular electrode portion 114a fixed to the bottom 102a of the case main body 102, A terminal portion 114b is drawn out of the case body 102 from the base portion 114a through the peripheral wall portion 102d.

The electrode portion 1 of the lead frame 114
14 a and the sensor chip 110 are electrically connected via wire leads 118.

In the pressure sensor having this configuration, the terminal portion 114b of the lead frame 114 is fixed by soldering on a wiring pattern of a substrate on which a pressure detection processing circuit (not shown) is mounted.

[0010] The sensor chip 110 is
A pressure received from a fluid or gas introduced into the inner hole 102c of b is detected, and a detection signal is input to the circuit via the wire leads 118, the lead frame 114, and a wiring pattern on a substrate (not shown). A pressure detection process is performed.

In the pressure sensor shown in FIGS. 14 and 15, a pressure introducing portion 102b is formed integrally with a case main body 102 of a package 100, but there is also a conventional pressure sensor having a configuration as shown in FIG. .

This pressure sensor has a flat plate-shaped substrate 120, and a cylindrical pressure introducing pipe 1 is provided at the bottom of the substrate 120.
22 is fixed using an adhesive or the like, and
The sensor chip 110 is mounted at the center of the upper part of the substrate. The sensor chip 110 faces the inner hole 122 a of the pressure introducing pipe 122 through the through hole 120 a formed in the substrate 120.

Lead frames 114 are drawn out from both sides of the substrate 120, and each lead frame 114 is electrically connected to the sensor chip 110 via a wire lead 118.

Further, the sensor chip 1 is provided on the substrate 120.
10 and a protective cover 113 covering each wire lead 118.
Is fitted, and a part of the protective cover 113 is open to the atmosphere.
13a are formed.

[0015]

The conventional sensors shown in FIGS. 14 to 16 have the following problems.

(1) Since the sensor chip 110 and the lead frame 114 are connected via the wire leads 118, a space for routing the wire leads 118 is required inside the package 100, and the lead frame 114 Has a large area wire bonding electrode 1
14a is required.

Further, since it is necessary to secure a space for inserting a capillary tube for wire bonding work in the package 100, the overall size of the package 100 is accordingly reduced.
It has a large shape several times or more than ten.

(2) Terminal 11 of lead frame 114
In order to solder and mount 4b on the wiring board, it is necessary to protrude out of the package 100, so that the mounting area is large.

(3) Since the package 110 and the lead frame 114 are separate bodies, the lead frame 114 has to be press-molded in a step different from the step of manufacturing the package 110, which is unnecessary for the package manufacturing. It takes man-hours and costs. In particular, in the configuration shown in FIG. 16, the pressure introduction pipe 122 also needs to be separately attached to the substrate 120, so that extra cost is required.

Further, when the lead frame 114 is formed by press molding, complicated wiring and a wiring pattern having a small width cannot be formed, which is a restriction in performing wiring connection.

Further, since the package 110 and the lead frame 114 are separate bodies, the occurrence of stress due to a change in temperature or the like causes a decrease in reliability to the environment.

Accordingly, it is an object of the present invention to provide a sensor which is much smaller in size than the conventional sensor, requires a smaller mounting area, and can be manufactured at low cost.

[0023]

The sensor according to the present invention employs the following structure in order to solve the above-mentioned problems.

That is, according to the first aspect of the present invention, there is provided a package which also serves as a wiring board, in which a sensor chip is mounted and a wiring portion for external connection is provided from the inside to the outside of the package. One end of this wiring portion is electrically connected to the sensor chip.

[0025] According to the second aspect of the present invention, the first aspect is provided.
In the configuration described above, the sensor chip has a movable electrode that is displaced in accordance with a change in a physical quantity and a fixed electrode that is arranged to face the movable electrode, and an electrode pad is formed on the fixed electrode. One end of the wiring portion is connected to the electrode pad.

Further, according to a third aspect of the present invention, in the configuration of the first or second aspect, the electrode pad of the sensor chip and one end of the wiring portion are electrically connected via an anisotropic conductive material. Have been.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a pressure sensor will be described. However, the present invention is not limited to this, and can be applied to other types of sensors for detecting physical quantities.

(Embodiment 1) FIG. 1 is a front sectional view of a pressure sensor of the embodiment 1, FIG. 2 is a perspective view of the sensor, FIG. 3 is an exploded perspective view showing the sensor with a part cut away, and FIG. 5 is a perspective view of the sensor in a longitudinal section, FIG. 5 is a perspective view of a package cap of the sensor as viewed from the bottom side, and FIG. 6 is a perspective view of a sensor chip of the sensor.

The pressure sensor 1 of the first embodiment basically includes a package 1 also serving as a wiring board and a sensor chip 2 mounted in the package 1.

The package 1 is formed by molding a high heat-resistant resin, and has a base 4 and a cap 6 to be put on the base 4, and the two 4 and 6 are fixed with a silicone adhesive or the like. It is integrated.

The base 4 has a cylindrical pressure-introducing portion 4b integrally protruding from substantially the center of the shallow-bottom box-shaped chip fixing portion 4a, and is formed inside the chip fixing portion 4a. The sensor chip 2 is fixed to the concave portion 4d with a silicone adhesive or the like, and faces the inner hole 4c of the pressure introducing portion 4b.

Furthermore, a pair of conductive wiring portions 8 extending from the upper surface of the chip fixing portion 4a to the lower surface via the side surfaces are formed on the base 4, and the lower surface side of the wiring portion 8 is used for external connection. The external electrode 8a, an electrode portion 8 for establishing electrical continuity with a wiring portion 10 whose upper surface is provided on a cap 6 described later.
b. The wiring portion 8 is formed by, for example, applying copper plating or, if necessary, nickel plating or gold plating thereon.

On the other hand, a recess 6a is formed in the cap 6 along the outer shape of the sensor chip 2, and an open-to-atmosphere port 6a penetrating the recess 6a in and out. Is provided with a pair of wiring portions 10. In this case, each wiring portion 10 is a via hole 1 in which a conductor is filled in a hole penetrating the cap 6 vertically.
0a and an electrode portion 10b formed on the lower surface of the cap 6 so as to be connected to the via hole 10a. Instead of the via hole 10b, a through hole provided with a conductive portion along the inner peripheral surface may be formed.

In a state where the base 4 and the cap 6 are integrally joined, the electrode portions 8b of the wiring portions 8 provided on the base 4 side and the wiring portions 10 provided on the cap 6 side are connected.
And the electrode portion 10b is in contact with each other to achieve mutual conduction.

On the other hand, the sensor chip 2 includes the movable electrode 12
And a fixed electrode 14 having a shape larger than the movable electrode 12.
And Then, the recess 6a of the above-mentioned cap 6
Is formed slightly larger than the movable electrode 12, and the recess 4d of the base 4 is also formed slightly larger than the fixed electrode 14, so that the outer surface of the sensor chip 2 is
Are very close to the inner wall surfaces, and the gap between the two is extremely small, contributing to the downsizing of the package 1.

The movable electrode 12 has a thin and flat pressure-sensitive portion 12a which is displaced in response to pressure application, and a thick-walled peripheral portion 12b which supports the periphery so as to allow displacement of the pressure-sensitive portion 12a. It is composed of

The fixed electrode 14 is provided with a hole 14 a communicating with the inner hole 4 c of the pressure introducing portion 4 b of the base 4 for introducing pressure to the movable electrode 12. As shown in FIG. 6, a pair of electrode pads 14b for extracting a pressure detection signal is formed on the remote upper surface, and each of the electrode portions 10b of the pair of wiring portions 10 provided on the cap 6 side is formed on the electrode pad 14b. Contact individually.

In this case, the electrode pad 1 of the sensor chip 2
In this example, the contact portion between the electrode portion 4b and the electrode portion 10b of the wiring portion 10 is electrically connected via an anisotropic conductive material (for example, an anisotropic conductive film or an anisotropic conductive adhesive). .

When using this anisotropic conductive material,
Although each electrode pad 14b of the sensor chip 1 and each electrode portion 10b of the wiring portion 10 are electrically conducted individually, short-circuiting between adjacent electrode pads 14b or between the electrode portions 10b can be prevented. There is an advantage that wiring connection can be easily performed.

When pressure is introduced into the movable electrode 12 from the inner hole 4c of the pressure introducing portion 4b of the base 4 through the hole 14a of the fixed electrode 14 of the sensor chip 2, the pressure-sensitive portion 14 of the movable electrode 10 is moved. The relative distance from the fixed electrode 12 is displaced by the pressure, and the electric capacity between the two electrodes 12 and 14 changes, so that an electric signal corresponding to the pressure can be obtained.

The pressure sensor according to the first embodiment has a circuit board 20 on which a pressure detection processing circuit is mounted in the state shown in FIG.
The external electrode 8a of the wiring portion 8 provided on the base 4 side of the package 1 is fixed by soldering on the wiring pattern of FIG.

The pressure sensor can be obtained by inverting the state shown in FIG. 1 upside down as necessary and connecting the via hole 10 a of the wiring section 10 provided on the cap 6 side of the package 1 to the circuit board 20. It is convenient because it can be used properly according to the usage form.

According to the first embodiment, the sensor chip 2
Need not be wire-bonded using a lead frame as in the prior art, and the space between the sensor chip 2 and the package 1 can be narrowed accordingly, so that the overall shape of the sensor can be significantly reduced. Moreover, since the wiring section 8 or 10 can be directly surface-mounted on the circuit board without using a lead frame, the mounting area can be reduced.

In the first embodiment, the wiring portions 8, 1 are provided on the base 4 side and the cap 6 side of the package 2, respectively.
0 is provided so that the pressure sensor can be used in either the state shown in FIG. 1 or the case where the pressure sensor is turned upside down. However, as shown in FIG. 7 and FIG. It is also possible to omit the wiring portion 8 and provide the wiring portion 10 only on the cap 6 side, and fix the via hole 10 b of the wiring portion 10 on the wiring pattern of the circuit board 20 by soldering. In this case, the mode of use is limited as compared with the configuration of FIG. 1, but the cost can be reduced because the wiring section 8 on the base 4 side is omitted.

The wiring section 8 can be provided only on the base 4 side of the package 2 and the wiring section 10 on the cap 6 side can be omitted.

(Embodiment 2) FIG. 9 is a front sectional view of a pressure sensor according to Embodiment 2, FIG. 10 is a perspective view of the same sensor, and FIG.
Numeral 1 is a perspective view of the sensor in a state where the sensor is longitudinally cut, and portions corresponding to respective components of the pressure sensor of the first embodiment shown in FIGS. 1 to 6 are denoted by the same reference numerals.

The feature of the pressure sensor according to the second embodiment is that the concave portion 6a of the cap 6 is formed at a deep bottom along the outer shape of the sensor chip 2, while the concave portion as in the first embodiment is formed in the base 4. Instead, a flange portion 4e that protrudes outward from the upper portion of the pressure introducing portion 4b is provided, and the sensor chip 2 is fixed to the flange portion 4e, and a cap 6 is attached over the sensor chip 2 to cover the sensor chip 2. I have.

The wiring section 10 composed of the via hole 10a and the electrode section 10b is provided only on the cap 6 side of the package 2.
And the wiring section 8 on the base 4 side as shown in FIG. 1 of the first embodiment is omitted.

The other configuration is basically the same as that of the first embodiment, and the detailed description is omitted here.

According to the structure of the second embodiment, the structure of the base 4 is simpler than that of the first embodiment shown in FIGS. Since the wiring section is omitted, the cost can be further reduced.

(Embodiment 3) FIG. 12 is a front sectional view of the pressure sensor of the embodiment 3, and FIG. 13 is a perspective view of the sensor. Each of the pressure sensors of the embodiment 1 shown in FIGS. Parts corresponding to parts are denoted by the same reference numerals.

The feature of the pressure sensor according to the third embodiment is that a concave portion 4d provided in the chip fixing portion 4a of the base 4 is formed at a deep bottom where the sensor chip 2 is buried. The pressure introducing portion 4b is formed so as to protrude in a state of being bent from the bottom surface side to the side surface, and an air opening 4f is provided at an upper portion of the side surface. on the other hand,
The cap 6 has a flat plate shape without the concave portion as in the first embodiment.

In addition to the sensor chip 2, the fixed substrate 1 of the sensor chip 2 is provided in the recess 4 d of the base 4.
An auxiliary substrate 16 for supporting the side 4 is interposed between the auxiliary substrate 16 and the chip fixing portion 4a, and a pair of via holes 18 as wiring portions penetrate through the auxiliary substrate 16 and the chip fixing portion 4a.
The upper end of the via hole 18 is electrically connected to a pair of electrode pads (not shown) for extracting a pressure detection signal provided on the fixed substrate 14 side of the sensor chip via an anisotropic conductive material. Have been.

The pressure sensor of the third embodiment has a circuit board 2 on which a pressure detection processing circuit is mounted in the state shown in FIG.
The portion of the via hole 18 is fixed by soldering on the 0 wiring pattern.

The other configuration is basically the same as that of the first embodiment, and a detailed description is omitted here.

The pressure sensor of the third embodiment is different from the pressure sensors of the first and second embodiments shown in FIGS. 1 to 5 in that the pressure introducing portion 4b of the package 1 extends along the circuit board 20. Since it does not protrude in the thickness direction of the chip 2 (vertical direction in the figure), the entire pressure sensor becomes thin,
This is convenient for reducing the thickness of the device including the circuit board 20 on which the pressure detection processing circuit is mounted.

In each of Embodiments 1 to 3 described above, the case where the present invention is applied to a pressure sensor has been described. However, the present invention is not limited to this, and may be applied to a sensor for detecting other physical quantities. Is also applicable.

[0058]

According to the present invention, the following effects can be obtained.

(1) According to the first aspect of the present invention, the sensor chip and the lead frame do not need to be connected by wire leads in the package unlike the related art, and the sensor chip is directly connected to the wiring portion. The gap between the outer surface of the chip and the inner surface of the package can be made extremely small, and the overall shape of the sensor can be greatly reduced.

Further, since there is no need to manufacture a lead frame separately from the package as in the prior art, the manufacturing cost is reduced.

Further, since the conventional lead frame does not protrude outside the package, the sensor mounting area can be reduced.

(2) According to the second aspect of the present invention, since the electrode pad is formed on the fixed electrode of the sensor chip, and one end of the wiring portion is directly connected to the electrode pad, the detection signal is extracted from the sensor chip. Becomes easier.

(3) According to the third aspect of the present invention, since the electrode pad of the sensor chip and one end of the wiring portion are electrically connected by an anisotropic conductive material, the wiring connection between the sensor chip and the wiring portion is made. The work can be performed very easily.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a pressure sensor according to a first embodiment.

FIG. 2 is a perspective view showing the appearance of the pressure sensor of FIG. 1;

FIG. 3 is an exploded perspective view showing the pressure sensor of FIG. 1 with a part cut away.

FIG. 4 is a perspective view of a state in which the pressure sensor of FIG. 1 is cut longitudinally.

FIG. 5 is a perspective view of the package cap of the pressure sensor of FIG. 1 as viewed from the bottom side.

FIG. 6 is a perspective view of a sensor chip of the pressure sensor of FIG. 1;

FIG. 7 is a front sectional view showing a modification of the pressure sensor of FIG. 1;

FIG. 8 is a perspective view showing the appearance of the pressure sensor of FIG. 6;

FIG. 9 is a front sectional view of the pressure sensor according to the second embodiment.

FIG. 10 is a perspective view showing the appearance of the pressure sensor of FIG. 8;

FIG. 11 is a perspective view of a state in which the pressure sensor of FIG. 8 is cut longitudinally.

FIG. 12 is a front sectional view of a pressure sensor according to a third embodiment of the present invention.

FIG. 13 is a perspective view showing the appearance of the pressure sensor of FIG. 11;

FIG. 14 is an external perspective view of a conventional pressure sensor.

FIG. 15 is a front sectional view of the pressure sensor of FIG. 13;

FIG. 16 is a front sectional view of another conventional pressure sensor.

[Explanation of symbols]

1. Package, 2. Sensor chip, 4. Base, 4b
... pressure introduction part, 6 ... cap, 8, 10 ... wiring part, 12
... movable electrode, 14 ... fixed electrode, 14b ... electrode pad, 2
0: circuit board.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Koichi Furusawa O-Muron Co., Ltd. (10) Hanazono Todocho, Ukyo-ku, Kyoto-shi Inside (72) Inventor Kentaro Hara Within Omron Corporation, 10-10 Hanazono Todocho, Ukyo-ku, Kyoto, Kyoto Prefecture (72) Insider Taku Masai Within 10 Omron Corporation, Todocho, Hanazono, Ukyo-ku, Kyoto, Kyoto

Claims (3)

[Claims] A package that also serves as a wiring board;
In the package, a sensor chip is mounted, and a wiring portion for external connection is formed from the inside to the outside surface of the package, and one end of the wiring portion is electrically connected to the sensor chip. Sensor. 2. The sensor according to claim 1, wherein the sensor chip has a movable electrode displaced in accordance with a change in a physical quantity and a fixed electrode disposed opposite to the movable electrode. A sensor, wherein one end of the wiring portion is connected to the electrode pad. 3. The sensor according to claim 1, wherein the electrode pad of the sensor chip and one end of the wiring portion are electrically connected by an anisotropic conductive material.