JPH09178591A - Semiconductor pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease the number of components of semiconductor sensor by connecting the lead of a sensor unit electrically with the end of terminal and connecting the opening of housing on the side of sensor unit electrically and directly. SOLUTION: Output lead 3b of a sensor unit 3 is welded to the end 2a of a terminal 2 and connected electrically therewith. A potting agent 8 is then injected into a space defined by a frame part 1d and a cover 4. Subsequently, a protrusion 5b on a cover 5 is inserted into a groove 1e of a connector body 1 and bonded thereto through an adhesive 7. Finally, the potting agent 8 is thermally hardened to complete the assembly of semiconductor pressure sensor 100. The sensor 100 converts the pressure variation of a pressure medium, introduced from a pressure introduction port 5a, into variation of resistance through a semiconductor sensor chip. The variation of resistance is amplified and introduced to the terminal 2 through the output lead 3b thus detecting the pressure of pressure medium.

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 used for detecting, for example, intake air pressure or atmospheric pressure of an automobile.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor pressure sensor, an output terminal of a sensor unit for converting pressure into an electric signal is soldered to a circuit board, a lead as a relay terminal is provided on the circuit board, and one end of the lead is connected to the circuit board. Configuration in which the other end is passed through the case by soldering (Japanese Patent Publication No. 4-78027)
Alternatively, a configuration in which the sensor chip and the terminal terminal are electrically connected by wire bonding (Japanese Patent Laid-Open No. 5-2407).
No. 23) is known. In these semiconductor pressure sensors, the external pressure detected by the sensor unit or the sensor chip is converted into an electric signal through the pressure introducing pipe, and the electric signal is output to the outside through the lead or the terminal terminal.

[0003]

However, in the technique disclosed in Japanese Patent Publication No. 4-78027, since the sensor unit and the outside are electrically connected via the leads, the number of parts is reduced. As the semiconductor pressure sensor increases in size and cost, and in addition, the sensor unit and the leads are soldered to the circuit board, the number of soldering points also increases, resulting in inefficient assembly. is there. The technique disclosed in Japanese Patent Laid-Open No. 5-240723 also has a configuration in which the sensor chip and the terminal terminal are electrically connected by wire bonding, and therefore is compared with the case where the sensor chip and the terminal terminal are directly connected. As a result, the number of connection points increases and the manufacturing efficiency is not good. Also, when the sensor unit is a metal case type and the pressure introducing pipe is made of metal, dew condensation occurs inside the pressure introducing pipe, and for example, there is a problem that it freezes in a low temperature environment of -20 ° C or less, and the external pressure is normally However, there were problems such as failure to measure and damage to the silicon diaphragm of the semiconductor pressure sensor. Therefore, in view of the above problems, an object of the present invention is to provide a semiconductor pressure sensor having a small number of parts, small size, light weight, low cost, and good manufacturing efficiency, at the same time preventing dew condensation in the sensor, and even in a low temperature environment. An object of the present invention is to provide a highly reliable semiconductor pressure sensor that can normally measure external pressure.

[0004]

Means for Solving the Problems To solve the above-mentioned problems, the means described in claim 1 can be adopted. According to this means, the cylindrical pressure introduction portion is formed in the direction of the opening by protruding from the inner side surface of the frame-shaped housing having the openings in the two opposite directions, and the sensor unit is fixedly mounted on one end surface thereof. To do. A connector portion is provided adjacent to the housing, and a terminal is provided so as to penetrate the connector portion so that one end of the terminal projects into the housing and is close to the leads of the sensor unit. Then, the lead of the sensor unit and the end of the terminal are directly electrically connected. Then, the opening on the sensor unit side of the housing is covered with the first cover. As a result, the terminal and the lead can be directly electrically connected, so that it is not necessary to interpose a circuit board or a relay terminal between the terminal and the lead, and the number of parts of the semiconductor pressure sensor can be reduced. . Moreover, since the number of electrically connected portions can be reduced, the manufacturing efficiency of the semiconductor pressure sensor can be improved.

According to the second aspect of the invention, the second cover having the cylindrical port portion covers the other opening of the housing to effectively prevent dew condensation in the semiconductor pressure sensor. can do.

According to the third aspect of the present invention, by integrally forming the connector portion and the housing, the parts required for assembling the connector portion and the housing and the number of assembling steps can be reduced, and the semiconductor pressure sensor. It is effective in reducing the size, weight and cost.

According to the fourth aspect, the terminals and the leads of the sensor unit are electrically connected by soldering or welding. Thereby, the electrical connection between the terminal and the lead can be surely made.

According to the means described in claim 5, by thinning the end portion of the terminal, the displacement or strain of the sensor unit is received by the end portion of the terminal through the lead, and the sensor is elastically deformed at the end portion. The displacement and distortion of the unit can be absorbed.

According to the means described in claim 6, the resin material is injected into the space surrounded by the housing and the first cover, and the portion formed of metal such as the sensor unit and the lead is made into the resin material. To cover. As a result, the airtightness of those parts can be ensured and dew condensation can be prevented.

According to the seventh aspect of the invention, the resin material is injected into the space surrounded by the housing, the first cover and the second cover, and the pressure is applied between the pressure introducing portion and the port portion. Form a space. As a result, ingress of water from the outside can be prevented in the pressure space, so that condensation in the semiconductor pressure sensor can be prevented more effectively, and damage to the sensor chip due to freezing in a low temperature environment can be prevented. You can

According to the eighth aspect of the present invention, the first cover or the housing is provided with the first projecting portion projecting into the space surrounded by the first cover and the housing. Thereby, the contact area of the injected resin material can be increased and the adhesion of the resin material can be improved.

According to the ninth aspect of the invention, an adhesive or a rubber packing is used to seal between the housing and the first cover or the second cover. As a result, it is possible to effectively seal between the housing and the first cover or the second cover.

According to the means of claim 10, the engaging means engages the housing with the first cover or the second cover. Thereby, the seal between the housing and the first cover or the second cover can be more effectively performed.

According to the eleventh aspect, an adhesive or a rubber packing is used to seal between the sensor unit and the pressure introducing portion. This can effectively seal the space between the sensor unit and the pressure introducing portion.

According to the twelfth aspect of the present invention, the first cover is provided with the second protruding portion, and the second protruding portion presses the sensor unit toward the end face side of the pressure introducing portion. Thereby, the seal between the sensor unit and the pressure introducing portion can be more effectively performed.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, the present invention will be described based on specific embodiments. FIG. 1 is a schematic sectional view showing the configuration of the first embodiment according to the present invention. Semiconductor pressure sensor 100
Is a sensor unit 3 that detects pressure and converts it into an electrical signal, a terminal 2 that electrically connects the sensor unit 3 to the outside, and a connector body 1 on which the sensor unit 3 is mounted and the terminal 2 is provided. And a cover 4 (corresponding to a first cover) and a cover 5 (corresponding to a second cover) as a casing. In the sensor unit 3, a diaphragm type semiconductor sensor chip (not shown) is provided inside a metal case 3a. At the lower end of the sensor unit 3, an output lead 3b (corresponding to a lead) electrically connected to the semiconductor sensor chip is provided. Terminal 2 is made of metal such as brass,
Provided through the connector portion 1f of the connector body 1,
One end portion 2a having a thin wall thickness is welded to the output lead 3b of the sensor unit 3. The other end 2b of the terminal 2 is provided so as to project into the connector portion 1f and is electrically connected to an external connector (not shown).

The connector body 1 is made of a resin material, and has a connector portion 1f for electrically connecting to an external connector, a vacant portion 1d (corresponding to a housing) formed by opening in the vertical direction, and a vacant portion 1d. A pressure introducing pipe 1a which is formed so as to project toward the center of the arm portion 1d and introduces an external pressure.
(Corresponding to the pressure introducing section) and the like. The sensor unit 3 is placed on the upper end surface 1b (corresponding to one end surface) of the pressure introducing pipe 1a and is fixed with an adhesive. A protrusion-shaped pressing portion 1c is provided around the upper end of the arm portion 1d in order to enhance the sealing performance between the cover portion 4 and the rubber packing 6. Further, a groove portion 1e for attaching the cover 5 is provided at the lower end portion of the arm portion 1d. A perspective view of the connector main body 1 is shown in FIG. 4. A pair of grooves 1g and a projection 1h are provided on the outer surface of the arm portion 1d as engaging means capable of engaging with the cover 4.

The cover 4 assembled from above the arm portion 1d is made of a resin material and has a hole 4a formed therein. In addition, the cover 4 reduces the amount of the potting agent 8 (corresponding to a resin material) around the sensor unit 3 and expands the contact area with the potting agent 8 to improve the adhesion, so that the protrusion 4 b ( (Corresponding to the first protrusion) is provided. A perspective view of the cover 4 is shown in FIG. 5, and a flange 4c is provided on the side surface of the cover 4, and the flange 4c has a hole for allowing engagement with the projection 1h of the connector body 1. A section 4d is provided. The brim protrusion 4c and the hole 4d correspond to engaging means.

The cover 5, which is assembled from below the arm portion 1d, is made of a resin material, and has a pressure introducing port portion 5a (corresponding to a port portion) for introducing an external pressure inside, which is provided downward. Further, a protrusion 5b for connecting to the groove portion 1e of the connector body 1 is provided upward, and the protrusion 5b and the groove portion 1e are bonded to each other via an adhesive 7 made of a resin material. A potting agent 8 made of a resin material is injected into a space above the lower end of the pressure introducing pipe 1a in a space surrounded by the arm portion 1d and the covers 4 and 5. A pressure chamber 9 (corresponding to a pressure space) is formed between the lower end of the pressure introducing pipe 1a and the pressure introducing port portion 5a.

A semiconductor pressure sensor 100 having the above structure
The assembling method will be described. First, the sensor unit 3 is fixed to the upper end surface 1b of the pressure introducing pipe 1a with an adhesive. Next, the output lead 3b of the sensor unit 3 and the end 2a of the terminal 2 are welded and electrically connected. Subsequently, the brim protrusion 4c of the cover 4 provided with the packing 6 is attached to the connector main body 1 by using the groove 1g as a guide, the hole 4d is locked to the projection 1h, and the packing 6 is compressed to cover the cover 4 and the connector main body. Ensure the airtightness of the connection with 1. Then, the potting agent 8 is injected into the space surrounded by the vacuum portion 1d and the cover 4 to such an extent that it does not reach the lower end of the pressure introducing pipe 1a. After this, the groove portion 1 of the connector body 1
The protrusion 5b of the cover 5 is inserted into e, and the protrusion 5b is adhesively fixed via the adhesive 7. Then, the potting agent 8 is heated and cured, whereby the semiconductor pressure sensor 100
Assembly is completed.

In this semiconductor pressure sensor 100, the pressure change of the pressure medium such as air introduced from the pressure introducing port 5a is converted into the resistance change by the semiconductor sensor chip,
This is amplified by the amplifier circuit in the sensor chip and led to the terminal 2 through the output lead 3b. Then, the pressure of the pressure medium is detected based on the electric signal from the terminal 2.

With this structure, since the output lead 3b of the sensor unit 3 and the terminal 2 are directly connected by welding, a relay terminal such as a circuit board or a lead is not required, and the number of parts is reduced. Therefore, the semiconductor pressure sensor 100 can be reduced in size, weight, and cost. Moreover, since the number of electrical connection points can be reduced, the efficiency of assembly can be improved and the cost can be further reduced. Further, since the assembling can be performed in the vertical direction, the assembling can be easily automated. In addition, a potting agent 8 is arranged around the sensor unit 3 to ensure airtightness. The airtightness becomes better because the contact area of the potting agent 8 is increased by the protrusion 4b provided on the cover 4 and the adhesion is improved. In addition, since the large-volume pressure chamber 9 is provided between the pressure introducing pipe 1a and the pressure introducing port portion 5a, water or the like does not reach the inside of the sensor unit 3 from the outside and the inside of the sensor unit 3 is prevented. It is possible to prevent dew condensation, and to prevent problems such as damage to the diaphragm due to freezing even in a low temperature environment, and to realize a highly reliable semiconductor pressure sensor.

Although the pressure chamber 9 is provided between the pressure introducing pipe 1a and the pressure introducing port 5a in the above embodiment, a filter may be provided in the pressure chamber 9. This makes it possible to more reliably prevent water and the like from reaching the semiconductor sensor chip. In the above embodiment, the output lead 3b and the end 2a of the terminal 2 are electrically connected by welding. However, the output lead 3b and the terminal 2 are electrically connected by using another method such as soldering or wire bonding. You may connect to. In the above embodiment, the seal between the cover 4 and the connector body 1 is provided via the packing 6, but an adhesive may be used to seal between the cover 4 and the connector body 1. In this embodiment, the cover 5 and the connector body 1 are fixed by adhesion, but the cover 5 and the connector body 1 may be engaged with each other via a packing.

In this embodiment, the hole 4d of the cover 4 and the projection 1h of the connector body 1 are engaged with each other. However, the cover 4 is provided with a projection and the connector body 1 is provided with a hole to be engaged. Good. Although the cover 4 is provided with the brim protrusion 4c in the present embodiment, the connector body 1 may be provided with the brim protrusion. In this embodiment, the cover 4 has a protrusion 4
Although b is provided, the protrusion 1d may be provided on the arm 1d. Further, in this embodiment, the housing is provided with the frame-shaped frame portion 1d opened in the vertical direction, but the present invention is not limited to this. For example,
It is also possible to provide a housing that is open in three directions, which are the vertical direction and a part of the lateral direction, and the cover covers the vertical direction and the lateral direction of the housing. In the present invention, as long as the housing has one or more openings. , Its shape is not limited.
In this embodiment, the connector portion 1f and the arm portion 1d are integrally formed of the resin material, but the separately formed connector portion 1f and the arm portion 1d may be connected. Good.

(Second Embodiment) FIG. 2 is a schematic sectional view showing the structure of a second embodiment according to the present invention. A feature of the present embodiment is that the rubber packing 26 is used to ensure the airtightness between the sensor unit 30 and the upper end surface 10b of the pressure introducing pipe 10a in the semiconductor pressure sensor 101. The sensor unit 30 includes a metal stem 21 having a pressure introducing hole 21c, a sensor chip 22 for detecting pressure, a glass pedestal 23 on which the sensor chip 22 is mounted,
It is composed of a pin 21a for inputting and outputting an electric signal to the outside, a wire bond wire 25 for electrically connecting the pin 21a and the sensor chip 22, a metal cap 24 fixed to the stem 21 by welding, and the like. Sensor chip 22
Is a glass for incorporating a resistance for pressure conversion, an amplifying circuit, an external noise removing circuit, and the like, and eliminating mechanical strain generated when welding the cap 24 and the stem 21 and thermal strain from the stem 21. It is anodically bonded to the pedestal 23. The glass pedestal 23 is joined to the stem 21 by soldering. The pin 21a is hermetically sealed by the glass 21b and is provided so as to penetrate the stem 21. The upper end of the pin 21a has a wire bond wire 2
It is electrically connected to the sensor chip 22 through 5, and its lower end is soldered to the end 2a of the terminal 2.

The sensor unit 30 having the above structure is placed on the upper end surface 10b of the pressure introducing pipe 10a via the rubber packing 26, the cover 41 is attached, and pressure is applied downward. As a result, the cap 2 of the sensor unit 30
The edge of No. 4 is pressed downward by the protrusion 41b (corresponding to the second protrusion) of the cover 41, so that the rubber packing 26 is compressed. Thus, the airtightness between the lower surface of the stem 21 and the upper end surface 10b can be sufficiently ensured, and at the same time, the airtightness of the connecting portion between the cover 41 and the connector body 10 can be ensured by the packing 6. Then, the potting agent 8 is injected to the extent that a pressure chamber 9 is formed between the lower end of the pressure introducing pipe 10a and the upper end of the pressure introducing port portion 50a in the space surrounded by the connector body 10 and the cover 41, Protrusions 10 provided on the connector body 10
e and the groove 50b formed in the cover 50 with the adhesive 7
Connect through. With the semiconductor pressure sensor 101 having such a configuration, the same effect as that of the first embodiment can be obtained.

(Third Embodiment) FIG. 3 is a schematic sectional view showing the structure of a third embodiment according to the present invention. The feature of this embodiment is that in the semiconductor pressure sensor 102, the pressure introducing pipe 40a of the connector main body 40 is provided so as to project to the outside of the arm portion 40d, and the cover is not provided below the arm portion 40d. . As shown in FIG. 3, the semiconductor pressure sensor 102 does not have a pressure chamber, but since the pressure introducing pipe 40a is formed sufficiently long,
The same effects as those of the first and second embodiments can be obtained.
Also, by not providing a cover below the arm part 40d,
Since the number of parts can be reduced as compared with the first and second embodiments, the semiconductor pressure sensor 102 can be made smaller and lighter in weight, lower in cost, and more efficiently assembled.

As indicated above, according to the present invention,
Since the terminal and the output lead of the sensor unit are provided close to each other and are electrically connected by direct welding, a relay terminal and a circuit board are not required, so the number of parts and the electrical connection point can be reduced, and the semiconductor pressure sensor It is possible to realize small size, light weight, and low cost. By injecting a potting agent around the sensor unit, airtightness can be ensured and dew condensation in the sensor unit can be prevented. If a pressure chamber is formed between the pressure introducing port and the pressure introducing pipe, it is possible to prevent intrusion of water or the like into the sensor unit by the pressure chamber, and it is possible to effectively prevent dew condensation in the sensor unit.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a configuration of a first embodiment according to the present invention.

FIG. 2 is a schematic cross-sectional view showing the configuration of a second embodiment according to the present invention.

FIG. 3 is a schematic cross-sectional view showing the configuration of a third embodiment according to the present invention.

FIG. 4 is a perspective view showing a configuration of a connector body.

FIG. 5 is a perspective view showing a configuration of a cover.

[Explanation of symbols]

 1 Connector Main Body 1a Pressure Introducing Pipe 1b Upper End Facet 1c Pressing Part 1d Waku Part 1e Groove Part 1f Connector Part 1g Groove 1h Protrusion 2 Terminal 2a, 2b End Part 3 Sensor Unit 3a Case 3b Output Lead 4, 5 Cover 4a Hole 4b Projecting Part 4c Collar protrusion 4d Hole 5a Pressure introduction port 5b Protrusion 6 Packing 7 Adhesive 8 Potting agent 9 Pressure chamber 100 Semiconductor pressure sensor

Claims (12)

[Claims] 1. A housing having one or more openings and provided with a cylindrical pressure introducing portion formed so as to project from an inner side surface, and fixed on one end surface of the pressure introducing portion, A sensor unit that incorporates a semiconductor sensor chip, has a lead for electrical connection with the outside, and converts a pressure change of a pressure medium into an electric signal; A terminal for electrical connection with the connector is provided so that one end of the terminal projects into the housing and is provided in the vicinity of the lead, and at least the opening on the sensor unit side. A semiconductor pressure sensor, comprising: a first cover for closing; wherein the terminal and the lead are directly electrically connected. 2. The semiconductor pressure sensor according to claim 1, further comprising a second cover having a cylindrical port portion for introducing pressure. 3. The semiconductor pressure sensor according to claim 1, wherein the connector portion and the housing are integrally formed. 4. The semiconductor pressure sensor according to claim 1, wherein an end of the terminal and the lead of the sensor unit are electrically connected by welding or soldering. 5. The semiconductor pressure sensor according to claim 4, wherein the end portion of the terminal is thinned. 6. A resin material is injected into a space surrounded by the housing and the first cover, and a portion formed of metal in the space is covered with the resin material. The semiconductor pressure sensor according to claim 1. 7. A resin material is injected into a region surrounded by the housing, the first cover, and the second cover, except a region between the pressure introducing portion and the port portion,
A portion of the space formed of metal is covered with the resin material, and a pressure space in which the resin material is not injected is formed in a region between the pressure introducing portion and the port portion. The semiconductor pressure sensor according to claim 2, wherein the pressure introducing portion and the port portion are communicated with each other. 8. The semiconductor pressure sensor according to claim 6, wherein the first cover or the housing is formed with a first protrusion that protrudes into the space. 9. The semiconductor pressure sensor according to claim 1, wherein a gap between the housing and the first cover or the second cover is sealed by an adhesive or a rubber packing. 10. The semiconductor pressure sensor according to claim 9, further comprising engaging means for engaging the housing with the first cover or the second cover. 11. The semiconductor pressure sensor according to claim 1, wherein a gap between the sensor unit and the pressure introducing portion is sealed with an adhesive or a rubber packing. 12. The semiconductor pressure sensor according to claim 11, wherein the first cover is provided with a second protrusion that presses the sensor unit toward the end surface of the pressure introducing portion. .