JP2023011139A - Method for manufacturing pressure sensor assembly - Google Patents

Abstract

To manufacture a pressure sensor assembly at low cost by welding a pipe and a metal body connected to a pressure sensor chip by resistance welding so as to heighten the reliability of the pipe connection.SOLUTION: Provided is a method for manufacturing a pressure sensor assembly 51 comprising: a first and a second lead pipe 52, 53 connected to a first and a second pressure guide path leading from a first and a second pressure transmission chamber of a pressure measuring device to an inner space; and a pressure sensor chip 43 connected to the first and second lead pipes 52, 53, said method including a first step in which a first and a second washer 37, 38 are joined to crank-shaped first and second tubes 41, 42 to create the first and second lead pipes 52, 53. Also included is a second step in which the first and second lead pipes 52, 53 are joined to the pressure sensor chip 43 by being bypassed through a sensor case 54. Also included are a third step in which the pressure sensor chip 43 is joined to the fitting face of the sensor case 54 and a fourth step in which the pressure sensor chip 43 and the sensor case 54 are wired together.SELECTED DRAWING: Figure 4

Description

The present invention relates to a method of manufacturing a pressure sensor assembly having a pressure conduit connecting a sensor chip to the body of a pressure measuring device.

Conventionally, a pressure sensor chip made of Si or the like is used as a pressure detecting portion of an industrial pressure gauge. The pressure sensor chip is enclosed in, for example, a ceramic sensor case indicated by reference numeral 1 in FIG. 20 to eliminate the effects of contamination and humidity. 20, reference numeral 2 denotes a pressure sensor chip; 3, a lid for closing the opening of the sensor case 1; 4, a pipe for introducing pressure to the pressure sensor chip 2; As a conventional pressure gauge provided with such a pressure detection part, there is a pressure measuring device described in Patent Document 1, for example.

As shown in FIG. 21, the pressure measuring device disclosed in Patent Document 1 employs a configuration in which a sensor case 1 (sensor header) is enclosed in a metal body 5 such as stainless steel. By housing the sensor case 1 in the metal body 5 in this manner, the pressure sensor chip 2 can be protected from the external corrosive environment such as the medium to be measured. The pressure measuring device 6 shown in FIG. 21 uses two pipes 4 to lead pressure from the metal body 5 to the pressure sensor chip 2 inside the sensor case 1 .

The pipe 4 is connected to a pressure conduit 8 that opens into the internal space 7 of the metal body 5 . The pressure conduit 8 extends to a pressure transmission chamber 9 in the metal body 5 and is filled with a pressure transmission medium 10 . The pressure transmission chamber 9 is formed as part of its wall by a barrier diaphragm 11 in contact with the measuring medium (not shown).

In the conventional pressure measuring device 6 as shown in Patent Document 1, there is a problem in the connection between the metal body 5 and the pipe 4 on the sensor case 1 side. The connection between the pipe 4 and the metal body 5 preferably has a reliable welded structure from the viewpoint of environmental resistance. When the pipe 4 and the metal body 5 are connected by adhesion, the adhesive has low resistance to humidity, acid, alkali, etc., and the adhesive strength tends to deteriorate. Therefore, a mechanism that completely isolates the external environment is required. become.
When adopting the welding method for connecting the pipe 4 and the metal body 5, a washer ( not shown) must be welded.

Japanese Patent Application Laid-Open No. 2021-92489

However, when welding the straight-shaped pipe 4 to the metal body 5, the electrode for resistance welding interferes with the sensor case 1, so there is a problem that it is difficult to secure the work area necessary for welding. .
In addition, since the pitch between the two pressure-guiding holes of the pressure sensor chip 2 is as narrow as several millimeters, it is difficult to resistance-weld the pipe 4 to the metal body 5 with this pitch because of the shape of the washer. That is, if pipes 4 are connected to the two pressure guide holes formed at this pitch, and washers are welded to the ends of these pipes 4, the washers interfere with each other. If the pitch between the two pressure-guiding holes of the pressure sensor chip 2 is widened, the pressure sensor chip 2 becomes large, which increases the manufacturing cost.

SUMMARY OF THE INVENTION It is an object of the present invention to manufacture a pressure sensor assembly at a low cost in which a metal body and a pipe connected to a pressure sensor chip are welded by resistance welding to increase the reliability of the pipe connection. .

In order to achieve this object, a method of manufacturing a pressure sensor assembly according to the present invention provides a pressure measuring device in which a pressure receiving diaphragm, which is provided to receive the pressure of a process fluid to be measured, is part of the wall and a pressure transmission tube that is connected to a pressure transmission passage leading from a pressure transmission chamber containing a portion of a pressure transmission medium to an internal space of the pressure measuring device to guide the pressure of the pressure transmission medium; A method of manufacturing a pressure sensor assembly comprising a pressure sensor chip that receives pressure of a transmission medium and detects the pressure, wherein a fine tube is processed into a crank shape and one end of the fine tube is inserted through a washer. and a first opening is formed in one end surface of the other end of the pressure guiding tube manufactured in the first step after the first step. and a sensor case having a second opening formed on the other end face, the sensor case is penetrated from the first opening to the second opening, and the second opening outside the sensor case is made to pass through the second opening. a second step of holding the pressure sensor chip in the vicinity of the opening and joining the other end of the pressure guide tube and the pressure introducing portion of the pressure sensor chip; a third step of bonding to a wall surface near the first opening of the sensor case; and a fourth step of connecting terminals of the pressure sensor chip and conductive portions of the sensor case after the third step. The method.

The method of manufacturing the pressure sensor assembly of the present invention may include a fifth step of solder-sealing between the first opening and the pressure guide tube after the fourth step.

According to the present invention, in the method for manufacturing the pressure sensor assembly, the second opening of the sensor case is sealed with a cover member after the fifth step or between the fourth step and the fifth step. A method of manufacturing a pressure sensor assembly, comprising a sixth step of stopping.

According to the present invention, it is possible to manufacture a pressure sensor assembly at a low cost in which the impulse pipe connected to the pressure sensor chip and the metal body are welded by resistance welding to increase the reliability of the pipe connection. can.

FIG. 1 is a cross-sectional view of a pressure measuring device with a pressure sensor assembly according to the invention. FIG. 2 is a perspective cross-sectional view of the pressure measuring device. FIG. 3 is an exploded perspective view showing the body and resin case of the pressure measuring device in a cutaway manner. FIG. 4 is a perspective cross-sectional view of the pressure sensor assembly. FIG. 5 is an enlarged cross-sectional view showing the junction between the sensor case, the pressure sensor chip, and the thin tube. FIG. 6 is a cross-sectional view showing an enlarged joint between the washer and the thin tube. FIG. 7 is a perspective sectional view of the sensor case. FIG. 8 is a plan view of the pressure sensor assembly and substrate. FIG. 9 is a perspective view of the pressure sensor assembly and substrate. FIG. 10 is a flow chart for explaining a method of manufacturing a pressure sensor assembly according to the present invention. FIG. 11 is a front view of the pressure guiding tube for explaining the first step. FIG. 12 is a front view of a main part for explaining the second step. FIG. 13 is a cross-sectional view of a main part for explaining the third step. FIG. 14 is a perspective cross-sectional view showing an example of a sensor case. FIG. 15 is a perspective view of a main part for explaining the fourth step. FIG. 16 is a cross-sectional view of a main part for explaining the fifth step. FIG. 17 is a cross-sectional view of a main part for explaining the sixth step. FIG. 18 is a flow chart for explaining another example of the method of manufacturing the pressure sensor assembly. FIG. 19 is a perspective cross-sectional view for explaining the procedure for welding the washer to the body. FIG. 20 is a sectional view of a conventional sensor case. FIG. 21 is a cross-sectional view showing the configuration of a conventional pressure measuring device.

An embodiment of a method for manufacturing a pressure sensor assembly according to the present invention will now be described in detail with reference to FIGS. 1 to 19. FIG. First, a pressure measuring device using a pressure sensor assembly manufactured by the manufacturing method according to the present invention will be described.
A pressure measuring device 21 shown in FIG. 1 is constructed by assembling a plurality of functional parts, which will be described later, to a body 22 depicted in the center of FIG. The body 22 has a pressure receiving portion 23 drawn on the lower side in FIG. 1 and a detection portion 24 drawn on the upper side. The body 22 according to this embodiment is made of stainless steel.

The pressure-receiving portion 23 is formed in a plate shape whose thickness direction is the left-right direction in FIG. A second pipe 26 is connected. The inside of the first pipe 25 is filled with a first process fluid 27 to be measured. The interior of the second pipe 26 is filled with a second process fluid 28 to be measured.
A first pressure-receiving diaphragm 31 for receiving the pressure of the first process fluid 27 is provided at one end of the pressure-receiving portion 23 connected to the first pipe 25 , and the first pressure-receiving diaphragm 31 is A first pressure transmission chamber 32 is formed as part of the wall.
A second pressure receiving diaphragm 33 for receiving the pressure of the second process fluid 28 is provided at the other end of the pressure receiving portion 23 connected to the second pipe 26 , and the second pressure receiving diaphragm 33 A second pressure transmission chamber 34 is formed in which is a part of the wall.

The first pressure transmission chamber 32 and the second pressure transmission chamber 34 are, as shown in FIG. It communicates with the pressure chamber 44 (see FIG. 5) of the pressure sensor chip 43 through the first and second washers 37 and 38 and the first and second capillaries 41 and 42 of the detection section 24 . A pressure transmission system from the first and second pressure transmission chambers 32, 34 to the pressure chamber 44 is filled with a pressure transmission medium 45 (see FIGS. 1 and 5). The pressure sensor chip 43 receives the pressure of the pressure transmission medium 45 filled between the first and second pressure receiving diaphragms 31 and 33 and detects the pressure.

The detecting portion 24 of the body 22 is formed in a cylindrical shape and opens in the direction opposite to the pressure receiving portion 23 . An internal space 46 of the body 22 is formed within the detection section 24 . A cover 47 (see FIG. 1) is attached to the opening of the detector 24 and closed by the cover 47 .
As shown in FIG. 3, first and second pressure guide paths 35 and 36 are opened at the inner bottom of the detector 24, respectively. The first and second pressure guide paths 35 and 36 are formed inside the body 22 so as to communicate with the internal space 46 of the body 22 from the first and second pressure transmission chambers 32 and 34 .

A first washer 37 is attached to the open end of the first pressure guide path 35 that communicates with the internal space 46, as shown in FIG. A second washer 38 is attached to the open end of the second pressure guide path 36 that communicates with the internal space 46 . The first and second washers 37 and 38 are made of stainless steel and are disc-shaped and welded to the body 22 .

As shown in FIG. 6, convex portions 37a and 38a facing the inside of the first and second pressure guide paths 35 and 36 are provided at the central portions of the first and second washers 37 and 38, respectively. , through holes 48 and 49 are formed. As shown in FIG. 4, one end of a first thin tube 41, which will be described later, is inserted into and joined to the through hole 48 of the first washer 37. As shown in FIG. One end of a later-described second thin tube 42 is inserted and joined to the through hole 49 of the second washer 38 .

The first thin tube 41 and the second thin tube 42 are each made of stainless steel and bent into a crank shape. As shown in FIG. 4, the crank shape means that the first and second straight portions 41a and 42a including one ends (lower ends in FIG. 4) of the first and second thin tubes 41 and 42 are arranged in the first and second straight portions 41a and 42a. A shape in which the second linear portions 41b and 42b including the other ends of the thin tubes 41 and 42 are offset by a predetermined length in a direction orthogonal to the longitudinal direction of the first and second thin tubes 41 and 42. is.

The first and second tubules 41 and 42 are joined to the first and second washers 37 and 38 by fitting the outer circumferences of the tips of the tubules 41 and 42 to the edges of the through holes 48 and 49 that open to the projections 37a and 38a. It is done by welding the parts. As shown in FIG. 6, this welding is performed so that the weld 50 provides a liquid-tight seal between the first and second washers 37, 38 and the first and second tubules 41, 42. there is

A first capillary tube 41 welded to the first washer 37 and a second capillary tube 42 welded to the second washer 38 form part of the pressure sensor assembly indicated at 51 in FIG. It is.
The first washer 37 and the first narrow tube 41 constitute a first pressure guiding tube 52 connected to the first pressure guiding path 35 to guide the pressure of the pressure transmission medium 45 to the pressure sensor chip 43 . The second washer 38 and the second narrow tube 42 constitute a second pressure guiding tube 53 that is connected to the second pressure guiding path 36 and guides the pressure of the pressure transmission medium 45 to the pressure sensor chip 43 .

The pressure sensor assembly 51, as shown in FIG. , 42 and a sensor case 54 and a pressure sensor chip 43 joined to the other ends. The first and second capillaries 41, 42 extend from the first and second washers 37, 38 in the direction opposite to the pressure receiving portion 23 of the body 22, and connect the first and second washers 37, 38 and the sensor. The narrow tubes 41 and 42 are bent so that the distance between them and the case 54 is narrowed. The interval between the first and second capillaries 41 and 42 is widened on one end side welded to the first and second washers 37 and 38 and narrowed on the other end side joined to the sensor case 54 .

The sensor case 54 is formed of a ceramic material in the shape of a square tube with a bottom, and is joined to a cover member 55 formed of a ceramic material or a metal material. The pressure sensor chip 43 is formed in a cubic shape by stacking a plurality of plate-like members made of silicon in the thickness direction, and is accommodated in the sensor case 54 .
As shown in FIGS. 7A and 7B, the sensor case 54 is formed in the shape of a bottomed rectangular tube with one end surface 54a having a flat bottom surface, and is arranged in the opposite direction to the pressure receiving portion 23 of the body 22. opening towards. A first through-hole 56 and a second through-hole 57 are opened in one end surface 54a of the sensor case 54 as "first openings" in the present invention.

As shown in FIG. 7B, the other end surface 54b of the sensor case 54 has a chip insertion hole 58 as a "second opening" according to the invention. The chip insertion hole 58 is closed by the cover member 55 . The cover member 55 is formed in a plate shape and is fixed to the other end surface 54b of the sensor case 54 by brazing or seam welding in a state of closing the chip insertion hole 58. As shown in FIG. The operation of joining the cover member 55 to the sensor case 54 is performed so that the inside of the sensor case 54 is airtightly sealed while being filled with vacuum or _N2 .

The sensor case 54 according to this embodiment comprises a bottom wall 61 , a mounting seat 62 located on the opening side of the chip insertion hole 58 from the bottom wall 61 , and a wiring base 63 located near the opening of the chip insertion hole 58 . is formed.
The mounting seat 62 is formed with a flat mounting surface 62a (see FIG. 7B) to which the pressure sensor chip 43 is adhered. In this embodiment, the mounting surface 62a of the mounting seat 62 corresponds to the "wall surface near the first opening" in the present invention. The wiring base 63 is provided with a conductive portion 66 composed of a plurality of bonding pads 65 electrically connected to the pressure sensor chip 43 by a plurality of wires 64 (see FIG. 15). These bonding pads 65 are electrically connected to a plurality of electrode pads 67 (see FIG. 7A) provided on one end face 54a of the sensor case 54 by wiring (not shown) inside the sensor case 54. there is

In the electrode pad 67 according to this embodiment, the direction in which the first through hole 56 and the second through hole 57 are arranged in the bottom wall 61 (the direction in which the first capillary tube 41 and the second capillary tube 42 are arranged) They are arranged at both ends in the orthogonal direction.
These electrode pads 67 are soldered over soldering lands 69 formed on a substrate 68 (see FIG. 3). By performing this soldering, the sensor case 54 is electrically connected (mounted) to the soldering lands 69 while being placed on the substrate 68 .

The substrate 68 is formed in a disc shape as shown in FIG. The substrate 68 is formed with two circular through-holes 70, 70 through which the first and second washers 37, 38 can pass, and a slit 71 connecting the through-holes 70 with each other. The through hole 70 is formed in the substrate 68 at a position facing the open ends of the first and second pressure guide paths 35 and 36, as shown in FIG.

The operation of stacking the sensor case 54 on the substrate 68 is performed by passing the first and second washers 37 and 38 through the through holes 70 and 70 and passing the first and second capillaries 41 and 42 through the slits 71 . Also mounted on the substrate 68 are an electric circuit 72 (see FIGS. 8 and 9) for generating an electric signal from the detection output of the pressure sensor chip 43, and a connector terminal 73 for external connection. Although not shown, the substrate 68 has a wiring pattern for electrically connecting the soldering lands 69 and the electric circuit 72 and a wiring pattern for electrically connecting the electric circuit 72 and the connector terminal 73. and are formed. The positions at which the electric circuit 72 and the connector terminals 73 are mounted are not limited to the illustrated positions, and can be changed as appropriate.

A substrate 68 according to this embodiment is supported by a resin case 81 (see FIG. 3) and supported by the body 22 via the resin case 81 . The resin case 81 is formed in a bottomed cylindrical shape that can be accommodated in the internal space 46 of the body 22 . The resin case 81 has a mounting surface 82 on which the substrate 68 is mounted, claw pieces 83 for mounting and locking the substrate 68 on the mounting surface 82, and first and second washers 37 and 38. Two through holes 84, 84 are formed for passage.

Around the through hole 84 are two circular projections 85 projecting from the bottom wall 81a of the resin case 81 downward in FIG. Two cylinders 86, 86 protrude from 81a in the direction opposite to the pressure receiving portion 23 are provided. The circular protrusion 85 fits into a circular recess 87 formed in the body 22 so as to surround the first and second pressure guide paths 35 and 36 . A concave portion 88 is formed in the cylindrical body 86 for passing the first and second narrow tubes 41 and 42 .

By welding the first and second washers 37 and 38 to the body 22 while the substrate 68 is attached to the resin case 81, the substrate 68 can be mounted in a state in which the thickness direction of the substrate 68 is the vertical direction in FIG. is fixed to the body 22 . The vertical direction in FIG. 1 is the direction in which the open ends of the first and second pressure guide paths 35 and 36 are oriented.

As shown in FIG. 4, the pressure sensor chip 43 has a first hole 91 into which the other end of the first thin tube 41 is inserted, and a second hole 92 into which the other end of the second thin tube 42 is inserted. is formed. As shown in FIG. 5, the pressure sensor chip 43 according to this embodiment is adhered to the mounting seat 62 of the sensor case 54 with an adhesive 93 (see FIG. 5). The pressure sensor chip 43 is configured to detect the pressure difference between the pressure of the pressure transmission medium 45 transmitted to the first hole 91 and the pressure of the pressure transmission medium 45 transmitted to the second hole 92. there is Therefore, the first hole 91 and the second hole 92 serve as a pressure introducing portion 94 (see FIG. 5) of the pressure sensor chip 43 .

The first and second through holes 56 and 57 of the sensor case 54 are formed so as to pass through the bottom wall 61 . The hole diameters of the first and second through holes 56, 57 are such that the other ends of the first and second capillaries 41, 42 can pass through. The other end of the first thin tube 41 passes through the first through hole 56 and is inserted into the first hole 91 of the pressure sensor chip 43 to communicate with the pressure sensor chip 43 . The other end of the second thin tube 42 passes through the second through hole 57 and is inserted into the second hole 92 of the pressure sensor chip 43 to communicate with the pressure sensor chip 43 .

The first and second tubules 41 and 42 are adhered to the pressure sensor chip 43 with an adhesive 95, as shown in FIG. As this adhesive 95, an epoxy-based adhesive can be used. The inside of the sensor case 54 is in a state where the epoxy-based adhesive does not absorb moisture. This state is a vacuum state or a state filled with an inert gas such as N ₂ gas. In order to keep the inside of the sensor case 54 in such an inert state, the portions of the first and second thin tubes 41 and 42 that penetrate through the first and second through holes 56 and 57 of the sensor case 54 are soldered. sealed by the adhesive. Soldering is performed so that the solder 96 wets and spreads all around the first and second through holes 56 and 57 .

The first and second through-holes 56 and 57 of the sensor case 54 are metallized so that they can be soldered. The first and second thin tubes 41 and 42 are plated for soldering at the portions to be soldered to the first and second through holes 56 and 57 . This plating for soldering is Au plating with Ni as the base.

Next, the procedure for assembling the pressure measuring device 21 including the manufacturing method of the pressure sensor assembly configured as described above will be described. In assembling the pressure measuring device 21, the pressure sensor assembly 51 is manufactured first. The pressure sensor assembly 51 is completed by carrying out the first step S1 to the sixth step S6 shown in the flowchart shown in FIG.

(First step)
In the first step S1, two linear capillaries 101 as shown in FIG. 11(A) are prepared. At least part of these thin tubes 101 (the parts to be soldered to the first and second through holes 56 and 57) are plated for soldering in advance. A metallizing process is performed in advance on the portions where the first and second through holes 56 and 57 of the sensor case 54 and the cover member 55 are joined.

Then, as shown in FIG. 11(B), the two thin tubes 101 are processed into a crank shape to form a first thin tube 41 and a second thin tube 42 . Next, one end of the first thin tube 41 is inserted through the first washer 37 and these are joined by welding. Also, one end of the second thin tube 42 is inserted through the second washer 38 and these are joined by welding. By welding the first and second washers 37 and 38 to the first and second thin tubes 41 and 42 in this manner, the first and second pressure guide tubes 52 and 53 are manufactured.

(Second step)
A second step following the first step S1 is performed using a bonding jig 102 shown in FIG. The bonding jig 102 includes a pipe restraining portion 103 for restraining the first and second pressure guiding pipes 52 and 53, a chip restraining portion 104 for restraining the pressure sensor chip 43, and these pipe restraining portions 103. and a support portion 105 that supports the chip restraint portion 104 .
In the second step S2, the other end of the first pressure guiding tube 52 is passed through the sensor case 54 from the first through hole 56 of the sensor case 54 through the chip insertion hole 58. As shown in FIG. Also, the other end of the second pressure guiding pipe 53 is passed through the sensor case 54 so as to pass through the second through hole 57 of the sensor case 54 and the chip insertion hole 58 . Then, the bonding jig 102 holds the first and second pressure guiding pipes 52 and 53 and the sensor case 54 so that this state is maintained.

At this time, a clearance of a predetermined size is secured between the sensor case 54 and the tips of the first and second pressure guiding tubes 52 and 53 . The second linear portions 41b and 42b of the first thin tube 41 and the second thin tube 42 extend over the entire length of the sensor case 54 (the length from one end surface 54a to the other end surface 54b) so that this clearance can be widened. designed to be longer.
Next, the pressure sensor chip 43 is held by the bonding jig 102 outside the sensor case 54 and in the vicinity of the opening of the chip insertion hole 58 . At this time, the tips of the first and second pressure guiding pipes 52 and 53 are inserted into the first and second holes 91 and 91 by predetermined lengths.
After that, the adhesive 95 is injected into the openings of the first and second holes 91 and 92 and hardened. By curing the adhesive 95 , the other ends of the first and second pressure guiding tubes 52 and 53 and the pressure introducing portion 94 of the pressure sensor chip 43 are joined. After the adhesive 95 hardens, the assembly consisting of the first and second pressure guiding tubes 52 and 53, the sensor case 54 and the pressure sensor chip 43 is removed from the bonding jig 102. FIG.

(Third step)
After the second step S2, the pressure sensor chip 43 is bonded to the mounting surface 62a of the sensor case 54 in a third step S3. That is, first, as shown in FIG. 13A, an adhesive 93 is applied to the mounting surface 62a of the sensor case 54. Then, as shown in FIG. Then, as shown in FIG. 13B, the pressure sensor chip 43 is inserted into the sensor case 54 and adhered to the mounting surface 62a with the adhesive 93 interposed therebetween. The step of adhering the pressure sensor chip 43 to the sensor case 54 can also be performed after joining the pressure sensor chip 43 in a state in which the first and second pressure guide pipes 52 and 53 are not passed through the sensor case 54 . . In this case, as shown in FIG. 14, the sensor case 54 needs a slit 106 for inserting the first linear portions 41a, 42a and the curved portions 41c, 42c of the first and second narrow tubes 41, 42. become.

If the configuration shown in FIG. 14 is employed, the sensor case 54 becomes large and the number of laminated ceramic sheets for forming the sensor case 54 increases, resulting in an increase in manufacturing cost. Moreover, since the slit 106 of the sensor case 54 must be sealed, the width of the slit 106 is restricted, and a space for passing the first and second washers 37 and 38 through the slit 106 cannot be formed. Therefore, the first and second washers 37 and 38 must be welded to the first and second capillaries 41 and 42 after the pressure sensor chip 43 is adhered to the sensor case 54 . Since this welding must be performed while holding the first and second thin tubes 41 and 42 including the sensor case 54, it must be performed in a state of poor workability. Moreover, there is a risk that foreign matter may enter the first and second thin tubes 41 and 42 during welding, and it is not possible to inspect whether foreign matter has entered. According to the method of this embodiment, the foreign matter can be easily removed after the first and second washers 37, 38 are welded to the first and second capillaries 41, 42, so that the pressure sensor assembly has high reliability. A solid 51 can be manufactured.

(Fourth step)
After the third step S3, in a fourth step S4, as shown in FIG.
(Fifth step)
After completing the fourth step S4, in a fifth step S5, as shown in FIG. Solder 96 seals between the pressure guide pipes 52 and 53 .

(6th step)
After the fifth step S5, in a sixth step S6, as shown in FIG. At this time, the sensor case 54 and the first and second pressure guiding pipes 52 and 53 are loaded into a joining device (not shown), the inside of the sensor case 54 is made inactive, and the cover member 55 is brazed to the sensor case 54. Alternatively, attach by seam welding.
By sealing the opening (the first and second through holes 56 and 57) of the one end surface 54a of the sensor case 54 and the opening (the chip insertion hole 58) of the other end surface 54b in this way, the pressure sensor assembly 51 manufacturing process is completed. The sixth step S6 of joining the cover member 55 to the sensor case 54 can be performed between the fourth step S4 and the fifth step S5, as shown in FIG.

In assembling the pressure measuring device 21 using the pressure sensor assembly 51 , the pressure sensor assembly 51 is first attached to the substrate 68 . In this mounting operation, the first and second washers 37 and 38 are passed through the through holes 70 of the substrate 68, the first and second thin tubes 41 and 42 are passed through the slits 71, and the sensor case 54 is soldered to the substrate 68. and do. Thereafter, the substrate 68 is engaged with the resin case 81 and assembled. When assembling the board 68 to the resin case 81 , the first and second washers 37 , 38 pass through the resin case 81 while visually checking the first and second washers 37 , 38 through the through holes 70 of the board 68 . Adjust the position of the substrate 68 so that it enters the hole 84 .

After assembling the pressure sensor assembly 51 into the resin case 81, the pressure sensor chip 43 is characterized. By performing this characterization, the linearity of the sensor output of the pressure sensor chip 43, temperature specification, static pressure characteristics, etc. are corrected, and the influence of the surrounding environment such as ambient temperature and pressure can be removed. Become. For characterization, a pressure device (not shown) is connected to the first and second pressure guiding tubes 52 and 53, a measuring device (not shown) is connected to the connector terminal 73, and the pressure sensor assembly is subjected to a predetermined inspection. It is carried out while the temperature is maintained.

After performing the characterization, an assembly consisting of the pressure sensor assembly 51 and the resin case 81 is inserted into the internal space 46 of the body 22 and assembled to the body 22 . To do this, the circular projection 85 of the resin case 81 is fitted into the circular recess 87 of the body 22, and the projections 37a, 38a of the first and second washers 37, 38 are connected to the first and second pressure guides. It is inserted into the channels 35,36.

The first and second washers 37, 38 are then welded to the body 22. As shown in FIG. As shown in FIG. 19, this welding is performed by placing the body 22 on the lower electrode 111 and pressing the upper electrode 112 against the first and second washers 37 and 38 by resistance welding. The upper electrode 112 is rod-shaped, passes through the through hole 84 of the resin case 81 and the through hole 70 of the substrate 68, and overlaps the first and second washers 37 and 38. As shown in FIG. A slit 113 is formed in the distal end of the upper electrode 112 to allow the first and second capillaries 41 and 42 to pass therethrough.
After the first and second washers 37 and 38 are welded to the body 22, the pressure transmission medium 45 is filled in the pressure transmission path from the first and second pressure transmission chambers 32 and 34 to the pressure sensor chip 43. . This filling is performed using a filling hole (not shown) extending out of the body 22 from the first and second pressure transmission chambers 32,34.

The method of manufacturing the pressure sensor assembly 51 according to this embodiment comprises first and second capillaries 41 and 42 formed in a crank shape and first and second washers 37 and 38. A method of joining the pressure sensor chip 43 to the first and second pressure guiding pipes 52 and 53 in a state in which the pressure guiding pipes 52 and 53 are passed through the sensor case 54, and then joining the pressure sensor chip 43 to the sensor case 54. is. Therefore, it is possible to manufacture the pressure sensor assembly 51 in which the distance between the first washer 37 and the second washer 38 can be widened without enlarging the pressure sensor chip 43 .
Therefore, according to this pressure sensor assembly manufacturing method, resistance welding is used to weld the body 22 to the first and second impulse pipes 52, 53 connected to the pressure sensor chip 43, thereby improving the reliability of the pipe connection. The pressure sensor assembly 51 can be manufactured inexpensively.

21... Pressure measuring device 31... First pressure receiving diaphragm 32... First pressure transmitting chamber 33... Second pressure receiving diaphragm 34... Second pressure transmitting chamber 35... First pressure guiding path 36 2nd pressure guide path 37 1st washer 38 2nd washer 41 1st thin tube 42 2nd thin tube 43 Pressure sensor chip 45 Pressure transmission medium 46 Internal space 51 Pressure sensor assembly 52 First pressure guide tube 53 Second pressure guide tube 54 Sensor case 54a One end surface 54b Other end surface 56 First through hole (second 1 opening), 57... second through hole (first opening), 58... chip insertion hole (second opening), 62a... mounting surface (wall surface), 64... wire, 65... bonding pad, 66... Conductive portion 91 First hole 92 Second hole 94 Pressure introducing portion 96 Solder 101 Capillary tube 107 Terminal S1 First step S2 Second step S3 Second step 3 steps, S4...fourth step, S5...fifth step, 55...cover member, S6...sixth step.

Claims (3)

A pressure transmission chamber having a pressure receiving diaphragm provided in the pressure measuring device to receive the pressure of the process fluid to be measured as a part of the wall and containing a part of the pressure transmitting medium to the internal space of the pressure measuring device. a pressure guide pipe that is connected to the pressure guide path and guides the pressure of the pressure transmission medium;
A method for manufacturing a pressure sensor assembly comprising a pressure sensor chip that is connected to the pressure guide tube and receives the pressure of the pressure transmission medium to detect the pressure,
a first step of processing a thin tube into a crank shape and joining them together with one end of the thin tube inserted through a washer to form the pressure guide tube;
After the first step, the other end of the pressure guiding tube manufactured in the first step is inserted into the sensor case having a first opening formed in one end surface and a second opening formed in the other end surface. After penetrating from the first opening to the second opening, the pressure sensor chip is held outside the sensor case and in the vicinity of the second opening, a second step of joining the end and the pressure introducing portion of the pressure sensor chip;
a third step of bonding the pressure sensor chip to a wall surface near the first opening of the sensor case after the second step;
A method of manufacturing a pressure sensor assembly, further comprising, after the third step, a fourth step of connecting a terminal of the pressure sensor chip and a conductive portion of the sensor case. A method of manufacturing a pressure sensor assembly according to claim 1, comprising:
A method of manufacturing a pressure sensor assembly, comprising a fifth step of solder-sealing a gap between the first opening and the pressure guiding tube after the fourth step. 3. A method of manufacturing a pressure sensor assembly according to claim 2, comprising:
After the fifth step or between the fourth step and the fifth step, a sixth step of sealing the second opening of the sensor case with a cover member is included. A method of manufacturing an assembly.

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