JPH05223673A - Semiconductor pressure sensor - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a semiconductor pressure sensor which is capable of improving the mounting density and downsizing, is free from noise from the sensor characteristic checking terminal, and is low in manufacturing cost. [Structure] The tips of the sensor characteristic checking terminals 4 to 7 are slightly projected outward from one side of the case 9, and at the time of checking the sensor characteristics, the terminals on the sensor characteristic checker side are connected to the tips of the terminals 4 to 7. After the check, the terminal is separated from the tip of the sensor characteristic checking terminal, and the tip of the terminal is recessed in the cap 25.
Fix the power supply, sensor output, and ground terminals only to the circuit board.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor pressure sensor for detecting pressure such as intake air pressure, atmospheric pressure, exhaust pressure of an internal combustion engine mounted on an automobile or the like.

[0002]

2. Description of the Related Art In recent years, with the tightening of exhaust gas regulations for automobiles, it is necessary to control an automobile engine so as to always attain the best combustion state regardless of the motion state.
Therefore, the intake air pressure of the engine is detected using a pressure converter, and this is converted into an electric signal to electrically control the fuel supply amount, or to control the ignition timing so as to maintain an optimum combustion state. The method of detecting altitude changes and performing altitude correction has been adopted.

The pressure transducers for automobiles used for such applications are required to have excellent heat resistance and earthquake resistance, and semiconductor strain gauge type pressure sensors are widely adopted to satisfy these requirements. It has started to be done.

A conventional semiconductor pressure sensor of this type is shown in FIG.
It shows in FIG.

FIG. 8 is a plan view of a conventional semiconductor pressure sensor for measuring atmospheric pressure, FIG. 9 is a sectional view taken along line FF of FIG. 8, and FIG. 10 is FIG.
FIG.

In each figure, 1 is a power supply terminal, 2 is a sensor output terminal, 3 is a ground terminal, and 4,
5, 6, 7 and 8 are terminals for checking sensor characteristics. Each of the terminals 1 to 8 is fixed to the case 9 by an insert, and is formed in the same direction by a shoulder portion 10 thereof for the purpose of insertion into a circuit board (not shown).

Power supply, sensor output and ground terminals 1 to 3 and one sensor characteristic checking terminal 8 are arranged on one side of the case 9, and four sensors are arranged on the other side of the case 9. Characteristic checking terminals 4 to 7 are provided.

Sensor characteristic checking terminals 4 to 8
Is necessary when adjusting the sensor so that the sensor has desired output characteristics by connecting the tip end to a terminal on the sensor characteristic checker side (not shown), and is unnecessary after the adjustment.

In a recess 11 formed in the center of the case 9, a glass pedestal 14 to which a sensor element 13 having a pressure sensitive diaphragm 12 is anodically bonded is fixed by an adhesive 15. The pressure sensitive diaphragm 12 is used as the adhesive 15.
In order to prevent the transmission of the stress (external force, thermal stress, etc.) from the case 9 to the case 9, it is desirable to have elasticity.

On the pressure-sensitive diaphragm 12, a pressure detecting gauge resistor (not shown) and a signal line connecting the pressure detecting gauge resistor to form a Wheatstone bridge are formed by means such as diffusion. There is. An amplifying circuit, a filter circuit, an impedance converting circuit, a temperature compensating circuit (all are not shown), etc. are formed on the outer peripheral fixed portion of the sensor element 13 other than the pressure sensitive diaphragm 12 by means such as diffusion or sputtering. There is.

The power supply terminal 1 has a wire 16 at the base end.
And, it is connected to the predetermined circuit portion of the sensor element 13 via the electrode 17 and the electrode 17. In addition, the base end portion of the sensor output terminal 2 is connected to the predetermined circuit portion of the sensor element 13 via the wire 18 and the electrode 19, and the pressure detected by the pressure-sensitive diaphragm 12 is transferred from the electrode 19 to the wire. 1
It is led to the sensor output terminal 2 via 8. Further, the base end portion of the ground terminal 3 is connected to the predetermined circuit portion of the sensor element 13 via the wire 20 and the electrode 21. Further, each base end portion of the sensor characteristic checking terminals 4 to 8 is connected to the predetermined circuit portion of the sensor element 13 via the wire 22 and the electrode 23.

The wires 16, 18, 20, 22 and the sensor element 13 are covered with a silicon gel 24 for the purpose of environmental protection.

Reference numeral 25 denotes a cap, which is provided with an atmospheric hole (atmospheric pressure introducing hole) 27 which communicates with a space 26 in which the sensor element 13 is incorporated, and which is joined and fixed to the case 9 with an adhesive 28. ..

The semiconductor pressure sensor having such a structure is used by attaching the terminals 1 to 8 to a circuit board of a controller (not shown) by soldering or the like. The operation of the semiconductor pressure sensor thus configured will be described.

When measuring the intake air pressure and the atmospheric pressure of the internal combustion engine, the pressure introduced to the pressure sensitive diaphragm 12 through the atmospheric hole 27 of the cap 25 gives strain to the pressure sensitive diaphragm 12. This strain changes the value of the pressure detecting gauge resistance formed as a Wheatstone bridge on the pressure sensitive diaphragm 12, and this is output to the sensor element 13 as a pressure signal, and each circuit formed on the sensor element 13 changes the value. Temperature compensation, amplification, filtering, and impedance conversion are performed respectively, and output to the sensor output terminal 2 via the wire 18.
The atmospheric pressure or the pressure in the intake manifold can be known.

[0016]

In the conventional semiconductor pressure sensor, the terminals 1 to 8 extending on both sides of the case 9 are mounted on the circuit board of the controller by soldering or the like. Therefore, the surface of the case 9 becomes parallel to the surface of the circuit board, the projected area of the semiconductor pressure sensor at the time of mounting becomes large, and a large mounting space is required, which hinders improvement in mounting density and size reduction. Come.

Further, the sensor characteristic checking terminal 4
Nos. 8 to 8 are necessary only when the output characteristics of the sensor are adjusted before mounting, and are unnecessary after the output characteristics are adjusted, but they are projected to the outside of the case 9 long in the mounted state. For this reason, noise easily enters from the sensor characteristic checking terminals 4 to 8, which adversely affects the output characteristics of the sensor and increases the size of the entire sensor.

Further, it is necessary to perform a wasteful process of soldering the tip end portions of the sensor characteristic checking terminals 4 to 8 to the circuit board during mounting, which increases the number of work steps and increases the manufacturing cost.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to improve the packaging density and reduce the size, to prevent noise from entering the sensor characteristic checking terminal, and to manufacture it. An object is to provide a semiconductor pressure sensor that is low in cost.

[0020]

In order to achieve the above object, the semiconductor pressure sensor of the first invention of the present invention comprises a case, a sensor element, power supply / sensor output / ground terminals, and a sensor characteristic check terminal. And a cap having an air hole is joined to the case. In the semiconductor pressure sensor, a recess is provided on the inner surface of the side wall of the cap, and the tip of the sensor characteristic checking terminal is exposed to the recess. It is characterized by that.

Also, in the semiconductor pressure sensor of the second invention of the present invention, the sensor element, the power supply / sensor output / ground terminals, and the sensor characteristic checking terminal are fixed to the case, and the case is fixed to the case. In a semiconductor pressure sensor formed by joining a cap having an air hole, a notch is provided in a side wall of the cap, and a tip end of the sensor characteristic checking terminal is inserted into the notch.

[0022]

When the sensor characteristic is checked, the terminal on the sensor characteristic checker side is connected to the tip end of the sensor characteristic check terminal which slightly protrudes outward on one side of the case.

After the sensor characteristic check is completed, the terminal on the sensor characteristic checker side is separated from the tip of the sensor characteristic check terminal, and the tip of the sensor characteristic check terminal is positioned in the recess or cutout portion of the cap, and the power source Mount only the sensor output and ground terminals by fixing them to the circuit board such as the controller by soldering.

[0024]

Embodiments of the present invention will be described below with reference to FIGS.

[First Embodiment] FIGS. 1 to 3 show a first embodiment of the present invention. FIG. 1 is a partially cutaway plan view of a semiconductor pressure sensor, and FIG. 2 is a sectional view taken along line AA of FIG. , FIG. 3 is BB of FIG.
FIG. Note that, in the present embodiment, the same functional portions as those of the conventional one described above will be described with the same reference numerals in the drawings.

The present embodiment is different from the conventional one in that only the power supply, sensor output, and ground terminals 1 to 3 are provided on one side of the case 9, and not shown on the inner surface of the other side wall of the cap 25. A concave portion 29 into which a terminal on the sensor characteristic checker side can be inserted is provided, and the tip portions of the four sensor characteristic checking terminals 4 to 7 arranged on the other side of the case 9 are made to face the concave portion 29 to form the sensor characteristic. After the check, the potting agent 30 made of resin is placed in the recess 29.
By filling in, the tip ends of the sensor characteristic checking terminals 4 to 7, which are slightly protruding to the outside of the case 9, are sealed. Further, a recess 31 is provided on the inner surface of one side wall of the cap 25, and a notch 32 is provided on the one side wall of the cap 25. From the side wall of the cap 25 through the notch 32, and the concave portion 31 is filled with the potting agent 33 made of resin.
Seal the middle of each terminal 1 to 3 of sensor output and ground. Furthermore, the tip ends of the power supply / sensor output / ground terminals 1 to 3 are attached to a circuit board of a controller (not shown) by soldering or the like for use. The recesses 29 and 31 are open on the lower surface side of the case 9.

Next, a manufacturing procedure of the above-mentioned semiconductor pressure sensor will be described.

First, each of the terminals 1 to 7 is assembled into the case 9 by cutting the terminals 1 to 7 in advance to a predetermined size and setting them in a molding die of the case 9 to mold the case 9. In this state, the tip ends of the sensor characteristic checking terminals 4 to 7 are slightly projected to one side of the case 9.

Next, a sensor characteristic checker-side terminal (not shown) is electrically connected to the tips of the sensor characteristic check terminals 4 to 7 to check the sensor characteristic.
After the sensor characteristic check is completed, the terminals on the sensor characteristic checker side are connected to the sensor characteristic check terminals 4 to 4.
The cap 25 is attached to the case 9 apart from the tip of the sensor 7, and the tips of the sensor characteristic checking terminals 4 to 7 are exposed in the recess 29.

Thereafter, the potting agent 3 is placed in the recess 29.
The semiconductor pressure sensor shown in FIGS. 1 to 3 is completed by filling 0 with the tip of the sensor characteristic checking terminals 4 to 7 and sealing the tip end portion of the cap 25 with the potting agent 33. To do.

In mounting the semiconductor pressure sensor, terminals 1 for power supply, sensor output, and ground 1 to
Only 3 is soldered to the circuit board of the controller or the like in a straight shape without being bent.

According to the above-described embodiment, when the sensor characteristic check is performed, the terminal on the sensor characteristic checker side can be electrically connected to the tip of the sensor characteristic check terminals 4 to 7. Therefore, the sensor characteristic check terminal 4 to Although the tip portion of 7 does not project to the outside of the case 9 for a long time, it does not hinder the electrical connection with the terminal on the sensor characteristic checker side.

When mounting the semiconductor pressure sensor,
Since only the terminals 1 to 3 are soldered to a circuit board or the like without being bent, stress due to bending is not applied to the sensor element 13 portion, and the projected area of the semiconductor pressure sensor at the time of mounting is small, and the mounting space is small. Since the number is small, the mounting density can be improved, the size can be reduced, and the number of soldering points can be reduced, so that the number of manufacturing steps can be reduced.

After the sensor characteristic check is completed, the tips of the sensor characteristic check terminals 4 to 7 are made to face the recess 29 of the cap 25 and sealed with the potting agent 30 filled in the recess 29. Since noise does not enter from the characteristic checking terminals 4 to 7, the output characteristics of the sensor are not adversely affected, and water does not enter, the durability of the sensor characteristic checking terminals 4 to 7 is improved.

Further, since each terminal 1 to 7 is cut into a predetermined size before assembly, each terminal 1 is assembled after assembly.
Sensor element 1 due to stress caused by cutting ~ 7
There is no adverse effect on the 3rd part.

In FIG. 2, reference numeral 34 denotes a fitting groove provided on the upper surface of the case 9 over the entire circumference thereof. The fitting groove 34 is provided in the fitting groove 34 on the lower surface of the cap 25 over the entire circumference thereof. Further, the fitting protrusions 35a and 35b having the double inner and outer structures are fitted and fixed by the adhesive 28. The side wall of the fitting groove 34 has an adhesive 28
It has the function of stopping the flow. In addition, the fitting protrusion 35
There is a gap between the a and 35b, and when the adhesive 28 protrudes, it is retained in the gap between the fitting protrusions 35a and 35b.

The operation of the semiconductor pressure sensor of the present invention having the above-mentioned structure is the same as that of the above-mentioned conventional one, and therefore its explanation is omitted.

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to FIGS.

In this embodiment, the same functional portions as those of the first embodiment described above will be described with the same reference numerals in the drawings.

In this embodiment, notches 36 and 37 are provided on both sides of the cap 25 corresponding to the terminals 1 to 7, and the terminals 1 to 7 are inserted into the notches 36 and 37. is there. The cap 25 covers the entire upper surface of the case 9. Further, the lower surface of the annular projection 25 a on the lower surface of the cap 25 is bonded to the upper surface of the case 9 with an adhesive 28. The protruding adhesive 28 collects in a space 31 defined by the inner and outer peripheral portions of the annular protrusion 25a.

In this embodiment, each terminal 1-7
After assembling the case 9 to the case 9, the sensor characteristic checking terminals 4 to 7 are cut to a predetermined size (the cut portion is a two-dot chain line in the figure), and then the sensor characteristic is checked, and then the cap 25 is attached to the case 9. To do.

The rest of the configuration, operation and effect of this embodiment are the same as those of the above-mentioned first embodiment, and the explanation thereof is omitted.

[0043]

As described above, according to the semiconductor pressure sensor of the first aspect of the present invention, since the tip of the sensor characteristic checking terminal faces the concave portion provided on the inner surface of the side wall of the cap, noise is generated from the tip. The noise will not affect the sensor characteristics, and the overall shape will be compact.

Further, at the time of mounting, only the power supply, sensor output, and ground terminals on one side of the case may be attached to the circuit board of the controller by soldering, so that the number of soldering points is small, The number of manufacturing steps can be reduced and the cost can be reduced, and the projected area of the semiconductor pressure sensor during mounting is reduced because the sensor characteristic check terminal does not extend outside the case, and the mounting space is small. Therefore, the mounting density is improved.

Further, it becomes possible to mount the power supply, sensor output, and ground terminals directly on the circuit board without bending, and by mounting in this way, the above-mentioned projected area at the time of mounting is greatly reduced. Becomes
The mounting density is further improved, and the stress due to bending does not act on the sensor element portion.

Further, according to the semiconductor pressure sensor of claim 2, since the tip end of the sensor characteristic checking terminal is inserted into the notch provided in the side wall of the cap, the same as the semiconductor pressure sensor of claim 1 described above. Produce an effect.

[Brief description of drawings]

FIG. 1 is a plan view of a semiconductor pressure sensor showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a plan view of a semiconductor pressure sensor showing a second embodiment of the present invention.

5 is a sectional view taken along line CC of FIG.

6 is a cross-sectional view taken along the line DD of FIG.

7 is a sectional view taken along line EE of FIG.

FIG. 8 is a plan view of a conventional semiconductor pressure sensor.

9 is a sectional view taken along line FF of FIG.

10 is a cross-sectional view taken along line GG of FIG.

[Explanation of symbols]

 1 Power supply terminal 2 Sensor output terminal 3 Ground terminal 4 Sensor characteristic check terminal 5 Sensor characteristic check terminal 6 Sensor characteristic check terminal 7 Sensor characteristic check terminal 9 Case 13 Sensor element 25 Cap 27 Atmosphere hole (atmospheric pressure introduction hole) 29 recess 36 notch

Claims (3)

[Claims] 1. A semiconductor pressure sensor comprising a case, a sensor element, a power supply / sensor output / ground terminal, and a sensor characteristic check terminal, which are fixed to each other, and a cap having an air hole is joined to the case. 2. A semiconductor pressure sensor according to claim 1, wherein a recess is provided on the inner surface of the side wall of the cap, and the tip of the sensor characteristic checking terminal is exposed in the recess. 2. The semiconductor pressure sensor according to claim 1, wherein the tip of the sensor characteristic checking terminal is sealed by filling a potting agent into the recess. 3. A semiconductor pressure sensor in which a sensor element, power supply / sensor output / ground terminals, and sensor characteristic check terminal are fixed to a case, and a cap having an atmospheric hole is joined to the case. 2. A semiconductor pressure sensor according to claim 1, wherein a notch is provided on the side wall of the cap, and the tip of the sensor characteristic checking terminal is inserted into the notch.