JP4045988B2 - Pressure sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressure sensor including a chip component connected to a connector pin.
[0002]
[Problems to be solved by the invention]
Conventionally, as a countermeasure against noise in the pressure sensor, the chip capacitor 3 is mounted by soldering between the connector pins 2 inside the connector of the pressure sensor as shown in FIG. 4, but the mounting method is reliable when soldering. Low.
Instead of soldering with such low reliability, mounting with a highly reliable silver paste is performed.
[0003]
However, as shown in FIG. 4, the space inside the connector 1 of the pressure sensor is very narrow, and in order to join and bond the chip capacitor 2 with silver paste, the connector 1 is shown by a two-dot chain line as shown in FIG. There is a method of dividing the connector 1a, 1b into the connector 1a, heat-curing the chip capacitor 3 with the silver paste in the connector 1a, and then integrating the connector 1b into the connector 1a. Overall, the cost increases.
[0004]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pressure sensor that can mount a chip component connected to a connector pin without reducing productivity and increasing the number of components. It is to provide.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, in the single state of the second housing, the surface on which the pressure detecting element is mounted is exposed to the outside, so that the chip component can be easily mounted on the same surface with the connector pin and the metal paste. Can be electrically connected. Further, since the chip component is protected by the protective member, the chip component can be isolated from the pressure transmission medium.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS.
FIG. 2 is a cross-sectional view showing an overall outline of the pressure sensor. In FIG. 2, the pressure sensor 11 is configured by integrating a metal main body housing (corresponding to a first housing) 12 and a resin connector housing (corresponding to a second housing) 13 by caulking. . A recess 14 is formed on the lower surface of the connector housing 13 in the figure, and a recess 15 is formed in the center of the recess 14, and a pressure detection element 16 is disposed in the recess 15. That is, the pressure detection element 16 is fixed to the recess 15 of the connector housing 13 with an adhesive while being anodically bonded to the glass pedestal 17, and the electrode is provided so as to surround the pressure detection element 16 through the bonding wire 18. Each connector pin 19 is connected to a ground terminal 19a, a Vcc terminal 19b, and a Vout terminal 19c (see FIG. 1C).
[0007]
A pressure introducing hole 20 is formed in the metal main body housing 12. A metal thin disc-like seal diaphragm 21 is attached to the upper surface of the main body housing 12 so as to close the pressure introducing hole 20, and a metal annular holding member is provided on the outer periphery of the seal diaphragm 21. 22 is attached. The entire circumference of the pressing member 22 is welded to the main body housing 12 via a seal diaphragm 21, whereby one end of the pressure introducing hole 20 is closed liquid-tightly by the seal diaphragm 21.
[0008]
In the state in which the main body housing 12 and the connector housing 13 are integrated, a liquid sealed space 23 is formed between the seal diaphragm 21 and the recessed portion 14 of the connector housing 13, and a pressure transmission medium is provided in the liquid sealed space 23. For example, silicon oil 24 is enclosed.
[0009]
Since the outer periphery of the main body housing 12 and the connector housing 13 is simply adhered by caulking, an O-ring is formed in the groove 25 formed in the connector housing 13 as a means for sealing the liquid sealing space 23 in a liquid-tight manner. 26 is arranged, and when the housings 12 and 13 are integrated by caulking, the O-ring 26 is crushed by a metal flange-like pressing member 22 that presses the seal diaphragm 21 so as to seal the silicon oil 24. .
[0010]
Here, a recessed portion 27 is formed in the recessed portion 14 of the connector housing 13, and a ground terminal 19 a 1, a Vcc terminal 19 b 1, and a Vout terminal 19 c 1 of each connector pin 19 are provided on the bottom surface of the recessed portion 27. In other words, each connector pin 19 has its terminals 19a to 19c positioned so as to surround the pressure detection element 16, and its shape is set so as to have the terminals 19a1 to 19c1 positioned on the bottom surface of the recess 27. Yes. In this case, as the terminals 19a1 to 19c1 located in the recess 27, the ground terminal 19a is located in the center, and the Vcc terminal 19b and the Vout terminal 19c are located on both sides thereof, and between the Vcc terminal 19b and the ground terminal 19a and Vout. A chip capacitor (corresponding to a chip component) 28 for noise suppression is joined and bonded between the terminal 19c and the ground terminal 19a by a silver paste (corresponding to a metal paste).
[0011]
In FIG. 3 showing the connector housing 13 in cross-section, each of the terminals 19a to 19c and 19a1 to 19c1 is potted with a sealing material 29 as a protective member, thereby making the connector pin 19 liquid-tight with respect to the silicon oil 24. In addition, the chip capacitor 28 is protected so as to be isolated from the silicon oil 24.
[0012]
Next, a method for manufacturing the pressure sensor having the above configuration will be described.
First, the glass pedestal 17 and the pressure detection element 16 are fixed to the concave portion 15 of the connector housing 12, and are electrically connected to the connector pins 19 by the bonding wires 18.
[0013]
Next, a silver paste is applied to each of the terminals 19a to 19c located on the bottom surface of the recess 27 by a dispenser, and then a chip capacitor 28 is mounted by a chip mounter.
Then, after the chip capacitor 28 is bonded and bonded to the terminals 19a to 19c by heat curing (see FIG. 1B), the sealing material 29 is potted on the terminal portions 19a to 19c and 19a1 to 19c1 (see FIG. 1). 1 (c)).
[0014]
Next, the O-ring 26 is arranged at the position shown in FIG. 1, the pressure detection element 16 side of the connector housing 13 is turned up (the top and bottom in FIG. 2 are reversed), and from above the recess 15 of the connector housing 13. The silicon oil 24 is weighed at a constant weight, and is metered in with a dispenser or the like. It is also possible to place the connector housing 13 on a weighing scale and inject the silicon oil 24 and stop the injection when the weight increases by a certain amount to obtain a certain amount of silicon oil. In this case, the certain amount is an amount in which the seal diaphragm 21 becomes an ideal diaphragm shape as the pressure sensor 11 when the silicon oil 24 is sealed.
[0015]
Next, the main body housing 12 to which the seal diaphragm 21 is welded on the entire circumference is lowered so as to be fitted to the connector housing 13 while maintaining the level from above, and is pressed until the upper end surface 13a of the connector housing 13 and the pressing member 22 are sufficiently in contact with each other. The main body housing 12 is fixed by caulking all around.
The pressure sensor 11 can be manufactured as described above.
[0016]
According to such an embodiment, since the chip capacitor 28 for noise suppression is mounted on the same surface where the pressure detecting element 16 is mounted in the connector housing 13, the chip capacitor 28 is connected to the connector pin with silver paste. The 19 terminals 19a1 to 19c1 can be easily joined and bonded, and the connection reliability of the chip capacitor 28 can be ensured. Therefore, unlike the conventional example in which the connector housing is divided in order to mount the chip capacitor in the connector housing with silver paste, the chip capacitor 28 can be mounted without dividing the connector housing 13. A pressure sensor can be produced without a decrease in performance.
In addition, as a result of mounting the chip capacitor 28 on the same surface as the pressure detection element 16, it is possible to mount the chip capacitor 28 by a chip mounter after mounting the pressure detection element 16, and the productivity can be further increased.
[0017]
The present invention is not limited to the above-described embodiment, and may be applied to mounting chip components other than chip capacitors according to the circuit configuration.
[Brief description of the drawings]
FIG. 1 is a plan view of a connector housing showing a manufacturing procedure in an embodiment of the present invention. FIG. 2 is a cross-sectional view of a pressure sensor. FIG. 3 is a cross-sectional view of the main part of the connector housing. Plan view of connector [Fig. 5] Cross section of connector [Explanation of symbols]
11 is a pressure sensor, 12 is a main body housing (first housing), 13 is a connector housing (second housing), 19 is a connector pin, 23 is a liquid enclosure space, 24 is silicone oil (pressure transmission medium), and 28 is A chip capacitor (chip component) 28 is a sealing material (protective member).

Claims (2)

A first housing having a diaphragm that is displaced according to the pressure of a pressure acting medium introduced from the outside;
A second housing having a pressure detecting element for converting the applied pressure into a signal and outputting the signal;
A liquid-filled space closed by the diaphragm and the second housing in a state where the first housing and the second housing are integrated;
A pressure transmission medium enclosed in the liquid enclosure space;
A connector pin that is provided in the second housing and outputs a signal from the pressure detection element;
In a pressure sensor comprising a chip component connected to this connector pin,
The chip component is mounted on the same surface on which the pressure detection element is mounted in the second housing in a state of being electrically connected to the connector pin by a metal paste and isolated from the pressure transmission medium by a protective member. A pressure sensor. The pressure sensor according to claim 1, wherein the chip component is a chip capacitor.

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