JP2023099902A - Pressure sensor manufacturing method - Google Patents

Abstract

To provide a pressure sensor manufacturing method with which it is possible to secure a pressure sensor chip to a sensor case in just a few steps.SOLUTION: This manufacturing method includes a first step in which a pressure sensor chip 16 is bonded to one ends of first and second lead pipes 6, 7, the other ends of which are connected to first and second pressure guide paths for transmitting the pressure to be measured, and the lead pipes 6, 7 are put through first and second through-holes 14, 15 of a case body 11. The manufacturing method includes a second step in which the pressure sensor chip 16 is located to the case body 11, and the first and second lead pipes 6, 7 are soldered to the case body 11. The manufacturing method includes a third step in which the pressure sensor chip 16 and the bonding pads (conductor sections) of the case body 11 are connected by bonding wire. The manufacturing method includes a fourth step in which a lid is joined to an opening of the case body to seal off the inside of the case body.SELECTED DRAWING: Figure 8

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing a pressure sensor that simultaneously supports a pressure sensor chip and seals a pressure guiding tube penetration.

2. Description of the Related Art Conventionally, as a pressure sensor, there is one that uses a pressure guiding tube for introducing a pressure to be measured, as described in Patent Document 1, for example. The pressure guide tube disclosed in Patent Document 1 connects the pressure guide path of the pressure measuring device body and the pressure sensor. The connection between the pressure conduit and the pressure sensor can be made using an adhesive, for example. When an epoxy-based adhesive is used as the adhesive, it is desirable to cover the adhesive portion with a sensor case in order to prevent the adhesive from deteriorating due to moisture absorption.

That is, the pressure sensor chip having the pressure detecting portion is adhered to the pressure sensor chip with an adhesive, and the pressure sensor chip including the adhered portion is enclosed in the sensor case. In this case, the sensor case is preferably made of ceramics so that the signal extraction structure can be easily formed. When using a ceramic sensor case that covers the pressure sensor chip, the part through which the impulse line penetrates the sensor case is sealed by soldering.

Japanese Patent No. 5089018

In housing the pressure sensor chip in the sensor case, there was a problem with the method of fixing the pressure sensor chip to the sensor case. Since the pressure sensor chip must be electrically connected to the conductor portion of the sensor case, it must be fixed against movement with respect to the sensor case. If this fixation is performed with an adhesive, an adhesion process for fixing the pressure sensor chip to the sensor case and an adhesion process for adhering the pressure guide pipe to the pressure sensor chip are required, increasing the number of man-hours and increasing the pressure. The manufacturing cost of the sensor becomes high.

SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure sensor manufacturing method capable of fixing a pressure sensor chip to a sensor case with a small number of steps.

In order to achieve this object, the method of manufacturing a pressure sensor according to the present invention includes: bonding a pressure sensor chip to the other end of a pressure guiding tube, one end of which is connected to a pressure guiding path for transmitting pressure to be measured; A first step of passing the pressure guide tube through a through hole of a sensor case containing a pressure sensor chip, and a second step of positioning the pressure sensor chip with respect to the sensor case and soldering the pressure lead tube to the sensor case. a third step of connecting the pressure sensor chip and the conductor portion of the sensor case with a bonding wire; 4 steps.

According to the present invention, in the pressure sensor manufacturing method, the first step includes welding a washer to be welded to the pressure measuring device body to the one end of the pressure guide tube; through a through-hole of the sensor case, and bonding the pressure sensor chip to the other end of the sensor case, wherein the step of positioning the pressure sensor chip with respect to the sensor case in the second step includes: The pressure sensor chip and the sensor case may be combined with soldering jigs.

In the pressure sensor manufacturing method according to the present invention, in the step of combining the pressure sensor chip and the sensor case with soldering jigs in the second step, the opening of the sensor case faces downward. The sensor case and the pressure sensor chip are placed on the soldering jig in the state of the pressure sensor, and the step of soldering the pressure guide tube to the sensor case in the second step is performed by placing the sensor case above the sensor case. Soldering may be performed from

In the present invention, the pressure sensor chip is fixed to the sensor case by soldering the pressure guide tube to the sensor case. Therefore, according to the present invention, it is possible to provide a pressure sensor manufacturing method capable of fixing a pressure sensor chip to a sensor case with a small number of steps.

FIG. 1 is a perspective view of a pressure sensor. FIG. 2 is a perspective cross-sectional view showing the pressure sensor broken. FIG. 3 is a cross-sectional view showing an enlarged main part of the pressure sensor. FIG. 4 is a perspective sectional view of the pressure measuring device. FIG. 5 is an exploded perspective view showing a part of the pressure measuring device cut away. FIG. 6 is a cross-sectional view showing the pressure receiving portion of the pressure measuring device. FIG. 7 is a flow chart for explaining a method of manufacturing a pressure sensor according to the present invention. FIG. 8 is a diagram for explaining the method of manufacturing the pressure sensor. FIG. 9 is a perspective view of a soldering jig. FIG. 10 is a cross-sectional view of the pressure sensor after wire bonding. FIG. 11 is a cross-sectional view of the pressure sensor with the lid attached.

An embodiment of a pressure sensor manufacturing method according to the present invention will now be described in detail with reference to FIGS. 1 to 11. FIG.
The pressure sensor 1 shown in FIG. 1 is used in the pressure measuring device 2 shown in FIG. and first and second pressure guide pipes 6, 7.

As shown in FIG. 2, the sensor case 4 is composed of a case main body 11 formed in the shape of a square tube with a bottom, and a lid 12 closing the opening of the case main body 11 . The case body 11 is made of a ceramic material, and the lid 12 is made of a ceramic material or a metal material. A first through hole 14 and a second through hole 15 are formed in the bottom wall 13 of the case body 11 . A first pressure guide tube 6 and a second pressure guide tube 7 are inserted through these first and second through holes 14 and 15 . These first and second pressure guide pipes 6 and 7 are connected to a pressure sensor chip 16 housed inside the sensor case 4 .

The pressure sensor chip 16 is formed in a cubic shape by stacking a plurality of plate-like members made of silicon in the thickness direction. The pressure sensor chip 16 is formed with a first hole 17 into which the first pressure guiding tube 6 is inserted and a second hole 18 into which the second pressure guiding tube 7 is inserted. The inside of the first hole 17 communicates with the first pressure chamber 16 a of the pressure sensor chip 16 , and the inside of the second hole 18 communicates with the second pressure chamber 16 b of the pressure sensor chip 16 . The pressure sensor chip 16 according to this embodiment measures the difference between the pressure transmitted from the first hole 17 to the first pressure chamber 16a and the pressure transmitted from the second hole 18 to the second pressure chamber 16b. configured to detect pressure.

The first and second pressure guide pipes 6 and 7 are each made of stainless steel and bent into a predetermined shape. Also, these first and second pressure guide pipes 6 and 7 are adhered to the pressure sensor chip 16 with an adhesive 19 as shown in FIG. As this adhesive 19, an epoxy-based adhesive can be used. The inside of the sensor case 4 is in a state where the epoxy-based adhesive 19 does not absorb moisture. This state is a vacuum state or a state filled with an inert gas such as N2 gas. In order to keep the inside of the sensor case 4 in such an inert state, the cover 12 is welded or brazed to the sensor case 4, and the first and second impulse lines 6 and 7 of the sensor case 4 are connected to the sensor case 4 by welding or brazing. Portions passing through the first and second through holes 14 and 15 are sealed by soldering. Soldering of the pressure guide tube penetration is performed so that the solder 20 wets and spreads over the entire circumference of the first and second through holes 14 and 15 .

The first and second through-holes 14, 15 of the case body 11 and the periphery of the openings of these first and second through-holes 14, 15 are metallized so that they can be soldered. It is The portions of the first and second pressure guiding pipes 6 and 7 that are inserted into the first and second through holes 14 and 15 are plated for soldering. This plating for soldering is Au plating with Ni as a base.

A bonding pad 21 is provided inside the sensor case 4 as a "conductor portion" according to the present invention. The bonding pads 21 are electrically connected to bonding pads 22 of the pressure sensor chip 16 via bonding wires 23 . Although not shown, the bonding pads 21 of the sensor case 4 are electrically connected to electrodes provided on the outer bottom surface of the sensor case 4 via conductors inside the sensor case 4 . The electrodes of the sensor case 4 are soldered to the soldering lands 24 of the substrate 3 (see FIG. 5). The substrate 3 is supported by the body 5 of the pressure measuring device 2 via a resin case 25 .

First and second washers 31 and 32 are welded to the ends of the first and second pressure guide tubes 6 and 7 of the pressure sensor 1 opposite to the pressure sensor chip 16. is connected to the body 5 of the pressure measuring device 2 via washers 31 and 32 of the pressure measuring device 2 . The first and second washers 31 and 32 are made of stainless steel and are disc-shaped and welded to the body 5 .
The body 5 is made of stainless steel, and as shown in FIG. 4, has a bottomed cylindrical detecting portion 33 to which first and second washers 31 and 32 are welded, and a plate-like pressure receiving portion 33. and a portion 34 . A resin case 25 is attached to the detecting portion 33 .

As shown in FIG. 6, the pressure receiving portion 34 has a first pipe 35 connected to one end in the thickness direction (left and right direction in FIG. 6) and a second pipe 35 connected to the other end in the thickness direction. A pipe 36 is connected. The inside of the first pipe 35 is filled with a first process fluid 37 to be measured. The interior of the second pipe 36 is filled with a second process fluid 38 to be measured.
A first pressure-receiving diaphragm 41 for receiving the pressure of the first process fluid 37 is provided at one end of the pressure-receiving portion 34 connected to the first pipe 35 , and the first pressure-receiving diaphragm 41 is A first pressure transmission chamber 42 is formed as part of the wall.
A second pressure receiving diaphragm 43 for receiving the pressure of the second process fluid 38 is provided at the other end of the pressure receiving portion 34 connected to the second pipe 36 , and the second pressure receiving diaphragm 43 A second pressure transmission chamber 44 is formed in which is a part of the wall.

The first pressure transmission chamber 42 and the second pressure transmission chamber 44 are composed of a first pressure transmission path 45 and a second pressure transmission path 46 for transmission of the pressure to be measured formed in the body 5 and a first pressure sensor chip 16 via first and second washers 31 and 32 welded to the openings of pressure guiding passage 45 and second pressure guiding passage 46 and first and second pressure guiding pipes 6 and 7; are connected to the first and second pressure chambers 16a and 16b. A pressure transmission system from the first and second pressure transmission chambers 42, 44 to the first and second pressure chambers 16a, 16b of the pressure sensor chip 16 is filled with a pressure transmission medium 47 (see FIG. 3). .

The detecting portion 33 of the body 5 is formed in a cylindrical shape and opens in the direction opposite to the pressure receiving portion 34 . The opening of the detector 33 is closed by a cover (not shown).
First and second pressure guide paths 45 and 46 are opened in the inner bottom portion of the detection portion 33, respectively. A first washer 31 is welded to the open end of the first pressure guide path 45 , and a second washer 32 is welded to the open end of the second pressure guide path 46 . The first washer 31 and the second washer 32 are passed through a through hole 48 formed in the resin case 25 .

Next, a method of manufacturing the pressure sensor 1 will be described with reference to the flow chart shown in FIG. 7 and FIGS. 8 to 11. FIG.
The pressure sensor 1 is manufactured by performing the first step S1 to the fourth step S4 of the flow chart of FIG. In the first step S1, first, as shown in FIG. 8A, the first and second washers 31, 32 are welded to the first and second pressure guide pipes 6, 7 (step S1A). The first and second pressure guiding pipes 6 and 7 are either plated for soldering except for the portions where the first and second washers 31 and 32 are welded, or are soldered. Use the one that is not plated for When using the first and second impulse pipes 6 and 7 that are not plated for soldering, the first and second impulse pipes are welded after the first and second washers 31 and 32 are welded. 6 and 7 are plated for soldering.

The first and second pressure guide pipes 6 and 7, to which the first and second washers 31 and 32 are welded and plated for soldering, are cleaned, including the inside of the pipe, and are then cleaned as shown in FIG. 8(B). As shown, it is passed through the first and second through holes 14 and 15 of the case body 11 and inserted into the first hole 17 and the second hole 18 of the pressure sensor chip 16 . Then, the first and second pressure guide pipes 6 and 7 are adhered to the pressure sensor chip 16 with an adhesive 19 (step S1B), and the pressure sensor chip 16 is placed inside the case body 11 as shown in FIG. 8(C). insert.

Next, a second step S2 is performed. In the second step S2, first, as shown in FIG. 8(D), the case main body 11 and the pressure sensor chip 16 are positioned for soldering so that the first and second pressure guiding tubes 6 and 7 are positioned upward. Place it on the jig 51 . As shown in FIG. 9, the soldering jig 51 has a pair of first grooves 52 into which one side and the other side of the case body 11 are fitted, and a second groove into which the pressure sensor chip 16 is fitted. grooves 53 are formed. By fitting the case body 11 into the first groove 52 and fitting the pressure sensor chip 16 into the second groove 53, the pressure sensor chip 16 is positioned with respect to the case body 11 (step S2A). After fitting the case main body 11 and the pressure sensor chip 16 to the soldering jig 51 in this manner, the first and second pressure guide pipes 6 and 7 are connected to the case main body as shown in FIG. 8(E). 11 is soldered (step S2B).

Then, as shown in FIG. 10, the bonding pads 21 of the case body 11 and the bonding pads 22 of the pressure sensor chip 16 are connected by bonding wires 23 (third step S3). Next, as shown in FIG. 11, the lid 12 is joined to the opening of the case body 11 by seam welding or brazing (fourth step S4), and the case body 11 is sealed. When joining the cover 12 to the case main body 11, the case main body 11 and the cover 12 are placed in a chamber (not shown), and the chamber is filled with an inert gas atmosphere or in a vacuum state. The pressure sensor 1 is completed by joining the cover 12 to the case body 11 .

In order to assemble the pressure sensor 1 thus formed to the body 5 of the pressure measuring device 2 , first, the sensor case 4 is mounted on the substrate 3 . At this time, the first and second washers 31 and 32 are passed through the two through holes 3a and 3a (see FIG. 5) of the substrate 3, and the first and second pressure pipes 6 and 7 are inserted into the slit 3b of the substrate 3. let through Then, the first and second washers 31 and 32 are passed through the through holes 48 of the resin case 25 and the substrate 3 is placed on the resin case 25 . At this time, the first and second washers 31 and 32 are connected to the openings of the first and second pressure guide paths 45 and 46, respectively. Then, a rod-shaped electrode (not shown) for resistance welding is inserted into the through hole 48 of the resin case 25 and superimposed on the first and second washers 31 and 32 , and the first and second electrodes are inserted between the rod-shaped electrode and the body 5 . The first and second washers 31 and 32 are welded to the body 5 by resistance welding with the two washers 31 and 32 interposed therebetween.

After the first and second washers 31, 32 are welded to the body 5, the pressure transmission path from the first and second pressure transmission chambers 42, 44 to the pressure sensor chip 16 is filled with the pressure transmission medium 47. . This filling is performed using filling holes (not shown) extending from the first and second pressure transmission chambers 42 and 44 to the outside of the body 5 .
After that, the pressure measuring device 2 is completed by attaching a cover to the detecting portion 33 of the body 5 .

In the pressure sensor 1 according to this embodiment, the pressure sensor chip 16 is adhered to the first and second pressure guide pipes 6 and 7, and the first and second through holes 14 and 15 of the sensor case 4 are filled with the first and second through holes 14 and 15. A first step S1 for passing the second pressure guide pipes 6 and 7, and positioning the pressure sensor chip 16 with respect to the case main body 11 of the sensor case 4 to connect the first and second pressure guide pipes 6 and 7 to the case main body 11. a third step S3 of connecting the pressure sensor chip 16 and the bonding pads 21 (conductor portions) of the case body 11 with bonding wires 23; It is manufactured by performing a fourth step S4 of joining the body 12 and sealing the inside of the case main body 11 .
In this manufacturing method, the pressure sensor chip 16 is fixed to the case body 11 by soldering the first and second pressure guiding tubes 6 and 7 to the case body 11 in the second step S2. Therefore, according to this embodiment, it is possible to provide a pressure sensor manufacturing method capable of fixing the pressure sensor chip to the sensor case with a small number of steps.
In particular, by adopting this manufacturing method, the pressure sensor chip 16 does not come into contact with the sensor case 4, so the influence of external force applied to the pressure sensor chip 16 via the sensor case 4 can be minimized. can.

In the first step S1 according to this embodiment, the first and second washers 31 and 32 welded to the body 5 of the pressure measuring device 2 are welded to one ends of the first and second impulse pipes 6 and 7. and step S1A, the other ends of the first and second pressure guiding tubes 6, 7 are passed through the first and second through holes 14, 15 of the case body 11, and the pressure sensor chip 16 is bonded to the other ends. It is implemented by step S1B and step S1B to carry out. Further, the step S2A of positioning the pressure sensor chip 16 with respect to the case body 11 in the second step S2 is performed by combining the pressure sensor chip 16 and the case body 11 with the soldering jig 51 respectively. Therefore, the pressure sensor chip 16 can be soldered to the case body 11 while the pressure sensor chip 16 is held by the soldering jig 51, so the soldering can be performed with high accuracy. be able to.

In this embodiment, the step S2A of combining the pressure sensor chip 16 and the case main body 11 with the soldering jig 51 is to attach the case main body 11 and the pressure sensor chip 16 with the opening of the sensor case 4 facing downward. The sensor is placed on a soldering jig 51 and then soldered from above the sensor case 4 . Therefore, the case main body 11 and the pressure sensor chip 16 can be easily positioned, and the soldering can be performed so that the solder 20 spreads sufficiently.

In the above-described embodiment, the pressure sensor chip 16 attaches the first and second impulse pipes 6 and 7 to the pressure sensor chip 16 after the first and second washers 31 and 32 are welded to the first and second impulse pipes 6 and 7 . However, the first and second washers 31 and 32 are attached to the first and second pressure pipes 6 and 7 after the first and second pressure pipes 6 and 7 are soldered to the case body 11. It may be welded to pressure pipes 6 and 7 . In this case, after bonding the first and second pressure guide tubes 6 and 7 to the pressure sensor chip 16, the first and second pressure guide tubes 6 and 7 are passed through the first and second through holes of the case body 11. be able to.

REFERENCE SIGNS LIST 1 pressure sensor 2 pressure measuring device 4 sensor case 5 body 12 lid 14 first through hole 15 second through hole 16 pressure sensor chip 21 bonding Pad (conductor portion) 23 Bonding wire 31 First washer 32 Second washer 45 First pressure guide path 46 Second pressure guide path 51 Soldering jig , S1...first step, S2...second step, S3...third step, S4...fourth step.

Claims (3)

A pressure sensor chip is adhered to the other end of a pressure guiding tube, one end of which is connected to a pressure guiding path for transmitting pressure to be measured, and the pressure guiding tube is passed through a through hole of a sensor case that accommodates the pressure sensor chip. 1 step;
a second step of positioning the pressure sensor chip with respect to the sensor case and soldering the pressure guide tube to the sensor case;
a third step of connecting the pressure sensor chip and the conductor portion of the sensor case with a bonding wire;
and a fourth step of joining a cover to the opening of the sensor case to seal the inside of the sensor case. In the method of manufacturing a pressure sensor according to claim 1,
The first step includes
welding a washer to be welded to the pressure measuring device body to the one end of the impulse tube;
a step of passing the other end of the pressure guide tube through the through hole of the sensor case and bonding the pressure sensor chip to the other end;
The step of positioning the pressure sensor chip with respect to the sensor case in the second step is performed by combining the pressure sensor chip and the sensor case with soldering jigs. Production method. In the method of manufacturing a pressure sensor according to claim 2,
In the step of combining the pressure sensor chip and the sensor case with soldering jigs in the second step, the sensor case and the pressure sensor chip are assembled with the opening of the sensor case facing downward. Place it on the soldering jig,
A method of manufacturing a pressure sensor, wherein the step of soldering the pressure guiding tube to the sensor case in the second step performs soldering from above the sensor case.

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