JPH03269332A - Semiconductor pressure sensor - Google Patents

Abstract

PURPOSE:To simplify the structure of the semiconductor pressure sensor and to improve its assembly by directly mounting a sensor element including a temperature compensating circuit, an amplifier circuit and a filter circuit on a hybrid circuit substrate in the sealed and joined state to a mount and connecting a receptacle to a lead terminal part. CONSTITUTION:The mount base 3 joined with the sensor element 2 on which a pressure sensitive diaphragm 1 is formed by means of electrostatic joining or the like is mounted on the hybrid circuit substrate 5 through a metal spacer 4 together with electronic parts 6 such as capacitors. The receptacle 12 is connected to the lead terminal 11. Pressure led to the diaphragm 1 through the hole 10 of a cap 9 applies distortion to the diaphragm 1. The distortion is outputted to the element 2 as a pressure signal and temperature compensation amplification and filtering are executed by the circuits formed on the substrate 5 to know atmospheric pressure or pressure in a manifold.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a semiconductor pressure sensor that detects intake air pressure, atmospheric pressure, exhaust pressure, etc. of an internal combustion engine installed in an automobile or the like.

(Prior Art) In recent years, with the tightening of automobile exhaust gas regulations, it is necessary to control automatic military engines so that they are always in the best combustion state regardless of their operating conditions. Therefore, a pressure transducer is used to detect the engine's intake pressure and convert it into an electrical signal to electronically control the fuel supply amount and control the ignition timing to maintain optimal combustion conditions. Methods that detect changes in atmospheric pressure and perform altitude correction are now being adopted.

Automotive pressure transducers used for such applications are
There is a demand for products with excellent heat resistance, earthquake resistance, etc., and semiconductor strain gauge type pressure sensors have come to be widely adopted to meet this demand.

This conventional semiconductor pressure sensor for rice will be explained with reference to FIG.

This figure is a side sectional view of a conventional semiconductor pressure sensor. A sensor element 23 and a ceramic substrate 24 are inserted into an outer case 22 molded with resin into which a pressure introduction pipe 21 is inserted.
An inner case 27 has a built-in printed circuit board 25 and is fixed with a gel 26 that protects each of the above components.
is installed.

Note that the tubular portion 23a of the sensor element 23 is inserted into the pressure introduction pipe 21, and two O-rings 28 prevent pressure gas from leaking. Also, a connection line 29 connected to the printed circuit board 25 and a connector line 31 connected to a connector 3o for taking out an output to an external control device (not shown).
is connected to the lower part of the outer case 22 and protected by resin 32.

(Problems to be Solved by the Invention) In the conventional configuration described above, since each component is assembled at the center of the outer case 22, the number of components and their connections increases.
In addition, it requires work to fix with gel 26 or resin 32,
The workability was poor, and therefore the production cost was high and reliability was low.

It is an object of the present invention to provide a semiconductor pressure sensor which eliminates the drawbacks of the prior art, simplifies the structure, significantly improves the ease of assembly, and is highly reliable and inexpensive.

(Means for Solving the Problems) The present invention has a structure in which a sensor element has a built-in temperature compensation, amplification, and filter circuit, and the sensor element is directly mounted on a hybrid circuit board while being sealed and bonded to a pedestal. In order to enable automatic mounting on a circuit board such as an engine controller, a socket is attached to the lead terminal portion.

(Function) With the above configuration, since the temperature compensation circuit and the amplification and filtering circuits are built into the sensor element, a corresponding circuit board is not required, and the sensor element is directly mounted on the hybrid circuit board. There is no need for cases, there are fewer connections, and the structure is simpler. Furthermore, since the lead terminal is attached to the hybrid circuit board and a socket is attached to the lead terminal part, the stability against deformation of the lead terminal is improved, and when attached to a circuit board such as an engine controller, This enables chucking based on the socket, making it possible to accurately and automatically mount hybrid circuit boards with unstable external dimensions.

- (Example) An example of the present invention will be described based on FIGS. 1 to 3. FIG. 1 is a plan view of a semiconductor pressure sensor of the present invention, FIG. 2 is a sectional view taken along line I-1 in FIG. 1, and FIG. 3 is a side view of the semiconductor pressure sensor.

As shown in FIG. 2, a pedestal 3 is bonded to a sensor element 2 on which a pressure-sensitive diaphragm l is formed by means such as electrostatic bonding.
is mounted on a hybrid circuit board 5 via a metal spacer 4 together with electronic components 6 such as capacitors. The metal spacer 4 and the hybrid circuit board 5 are joined by means such as soldering or adhesive. A bonding wire 7 connects an electrode (not shown) formed on the pressure sensitive diaphragm 1 to the hybrid circuit board 5, and a gel 8 coats the pressure sensitive diaphragm 1 and the bonding wire 7.

9 is a cap for protecting the pressure sensitive diaphragm 1 and the bonding wire 7, and has a hole 10 formed therein for pressure intake.

4-11 is a clip-shaped lead terminal attached to the hybrid circuit board 5, and 12 is a socket bonded to the lead terminal 11. Reference numeral 13 denotes a moisture-resistant insulating coating applied to the entire sensor except for the insertion portion 14 of the lead terminal 11 into the circuit board, the width direction surfaces 16.degree. 17 and the longitudinal direction surfaces 18 and 19 of the socket 12.

The end shape of the push-in part (4) of the lead terminal 11 is V-cut 20 so that it can be easily inserted into the hole of the circuit board.

Among the lead terminals 1, the f terminal is GND, the g terminal is the power input terminal, the h terminal is the sensor output terminal, and the remaining a
” The e and i-Q terminals are inserted into a characteristic check terminal and a circuit board such as an engine controller.
This is a terminal that serves to hold the sensor. socket 12
The width direction surface 16.17 or the longitudinal direction surface 18.19 is a chucking surface when the sensor is automatically mounted on a circuit board such as an engine controller, and the positional relationship with the insertion portion 14 of the lead terminal 11 is Dimensions are guaranteed with high accuracy.

The operation of the semiconductor pressure sensor configured in this way will be explained. When measuring the intake air pressure and atmospheric pressure of an internal combustion engine, the pressure introduced into the pressure-sensitive diaphragm 1 through the hole 10 of the cap 9 causes strain on the pressure-sensitive diaphragm 1. The strain in the pressure sensitive diaphragm 1 changes the value of the Wheatstone bridge resistance for pressure detection formed on the pressure sensitive diaphragm 1, and this is sent as a pressure signal to the sensor element 2.
temperature compensation, amplification, and filtering are performed by the circuit formed on the sensor element 2 and the circuit formed on the hybrid circuit board 5, and the bonding wire 7,
The signal is output to a lead terminal via the hybrid circuit board 5, and the atmospheric pressure or the pressure in the intake manhold can be determined from the signal value.

(Effects of the Invention) According to the present invention, since the temperature compensation circuit and the amplification and filtering circuits are built into the sensor element, a corresponding circuit board becomes unnecessary, and the sensor element is directly mounted on the hybrid circuit board. Because of this, there is no need for cases,
There are fewer connection parts and the structure is simpler.

Furthermore, since the lead terminal is attached to the hybrid circuit board and a socket is attached to the lead terminal part, the stability against deformation of the lead terminal is improved, and when attached to a circuit board such as an engine controller, the socket This makes it possible to chucking a hybrid circuit board with unstable external dimensions accurately and automatically, which has a great practical effect.

[Brief explanation of drawings]

FIG. 1 is a plan view of a semiconductor pressure sensor according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line I-1 in FIG. 1, FIG. 3 is a side view of the same, and FIG. 4 is a conventional semiconductor pressure sensor. FIG. 3 is a side sectional view of the pressure sensor. l...pressure sensitive diaphragm, 2...sensor element,
3...Pedestal, 4...Metal spacer, 5.
・Hybrid circuit board, 6 ・Electronic component, 7
... bonding wire, 8 ... gel, 9
... Cap, 10... Hole, 11... Lead terminal, 12... 7- socket, 13... Coating agent, 14...
・Insertion part, 16.17... Width direction surface, 18, 19...
・Longitudinal surface, 20...■Cut. 8

Claims (1)

[Claims] A sensor element incorporating a temperature compensation circuit and an amplification/filtering circuit, a pedestal sealed and bonded to the sensor element, a metal spacer for fixing the pedestal, and the sensor element mounted through the metal spacer. A semiconductor pressure sensor characterized in that it is of a direct mount type to a circuit board, and has a hybrid circuit board to be fixed, a lead terminal for outputting a signal from the hybrid circuit board, and a socket attached to the lead terminal.