JPH1194673A - Sensor and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the manufacturing efficiency by enabling a sensor to be miniaturized and to be made thinner. SOLUTION: When the sensor has a sensor chip 12 where a strain gage element is placed on a diaphragm 121 to detect the physical quantity of the diaphragm 121 and convert the same into an electric signal, a flexible board 13 is provided via a bump 21 on the upper surface of the diaphragm 12, on which the strain gage element is placed, and an electric circuit 23 amplifying the electric signal for output is provided on the flexible board 13. Since the electric circuit 23 on the flexible board 13 and the strain gage element on the diaphragm 121 are electrically connected together by the bump 21, a thinner thickness is achieved and a connection can be made through die bonding, so that the manufacturing time of the sensor can be reduced greatly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor having a sensor chip for arranging a strain gauge element on a diaphragm and detecting a physical quantity of the diaphragm to convert the sensor into an electric signal, and a method for manufacturing the sensor. Can be used for a pressure transducer or the like which detects a pressure change of the above by a diaphragm and outputs it as an electric signal by a strain gauge element.

[0002]

2. Description of the Related Art Conventionally, various pressure sensors have been used for measuring the pressure or the like of a fluid. As a pressure sensor for built-in control, a pressure sensor provided with a sensor chip for arranging a strain gauge element on a diaphragm and detecting a physical quantity of the diaphragm and converting it into an electric signal is used. For example, Utility Model Registration No. 2533357 There is known a pressure sensor indicated by the reference numeral. As shown in FIG. 9, the pressure sensor 7 includes a joint member 11 to which a piping member through which a fluid flows is connected, a pressure sensor chip 12 that detects the pressure of the fluid with a diaphragm 121, and converts the pressure into an electric signal. An electronic circuit board 73 for subjecting the electric signal converted by the pressure sensor chip 12 to signal amplification processing and outputting the signal to an external measuring device or the like; the pressure sensor chip 12 and the electronic circuit board 7
3 is provided.

[0003] The joint member 11 is a cylindrical body having a cavity 111 for pressure introduction formed therein, and a male screw portion 11 for connecting to the piping member is formed on the outer peripheral surface on the tip side.
2 are formed. The pressure sensor chip 12 includes a diaphragm 121 serving as a pressure receiving surface, and the diaphragm 121
And four strain gauge elements made of a semiconductor element such as polycrystalline silicon are arranged on the upper surface of the diaphragm 121 on the opposite side to the surface on which the leg parts 122 are provided. (Not shown in FIG. 9). These four strain gauge elements are electrically connected by a printed wiring formed on the upper surface of the diaphragm 121, and a bridge circuit composed of four resistance strain gauge elements is formed on the upper surface of the diaphragm 121. Electrode pads for voltage application are formed at a pair of opposite ends of the bridge circuit, and electrode pads for voltage output are formed at the other pair of ends.

[0004] A constant voltage is applied to such a bridge circuit, and the resistance value of the strain gauge element changes in accordance with the deformation of the diaphragm 121. With this, the changed voltage is converted into an electric signal for voltage output. Are output from the electrodes. The pressure sensor chip 12 is connected to the joint member 11 via a support 15. The support 15 has a pressure introduction pipe 151 formed therein, and the pressure introduction cavity 111 and the pressure sensor chip 12. The cavity 123 surrounded by the leg 122 is in communication with the pressure introducing pipe 151.

[0005] An electronic circuit board 73 is provided above the pressure sensor chip 12, and its outer peripheral portion is supported by the joint member 11. The electronic circuit board 73 is connected to the strain gauge elements on the upper surface of the diaphragm 121 and the bonding wires 7.
31 and is electrically connected to the external signal output electric wire 16 via the lead wire 732 and the relay board 733. Although not shown in FIG. 9, the electronic circuit board 73 includes an IC (Integr) serving as an electronic circuit that amplifies and outputs an input electric signal.
The IC and the bonding wire 731 are covered and protected by a cap 734.

[0006] When the pressure change of the fluid is measured by the pressure sensor 7, the following procedure is performed. The measurement fluid supplied from the pipe connected to the joint member 11 is supplied to the pressure introduction cavity 111 and the pressure introduction pipe 1.
51 flows into the cavity 123 of the pressure sensor chip 12. In response to the pressure change of the measurement fluid, the diaphragm 121
Is deformed in the out-of-plane direction, and the resistance value of the strain gauge element on the upper surface of the diaphragm 121 changes. As a result, the output voltage of the bridge circuit changes and is output to the electronic circuit board 73 as an electric signal. This electric signal is transmitted to the I
C, amplified by the lead wire 732, the relay board 73
3, transmitted to the display device and the control device (not shown in FIG. 9) by the electric wire 16, and the measurement and control are performed by these devices. The above-described pressure sensor 7 is incorporated in a device or the like, and is often used as a detector for controlling the device or the like. It is necessary to prevent the pressure sensor 7 from interfering with other operation units or the like of the device. In addition to miniaturization,
It is desirable that the thickness be reduced.

[0007]

However, such a conventional pressure sensor 7 has the following problems. The connection between the bridge circuit formed on the upper surface of the diaphragm 121 and the electronic circuit board 73 has been conventionally performed by wire bonding using bonding wires 731. However, due to the nature of the wire bonding technique, the electronic circuit board 73 is connected to the electronic circuit board 73. It is necessary to keep a predetermined distance from the pressure sensor chip 12. For this reason, as can be seen from FIG. 9, there is a limit even if the height dimension H0 of the case 74 is reduced to reduce the size and thickness of the pressure sensor 7. When connection is made by wire bonding, the bonding wire 73 is attached to the electrode pad on the diaphragm 121.
1 must be connected one by one. Therefore, when the number of bonding wires 731 increases, the pressure sensor 7
Takes a lot of time to manufacture, and the bonding wire 7
It is necessary to perform alignment of the pressure sensor chip 12 and the electronic circuit board 73 according to the connection position of the connection 31.
There is a problem that these position controls are complicated. It should be noted that such a problem is recognized not only by the above-described pressure sensor 7 but also by a flow rate sensor, an acceleration sensor, and the like having a sensor chip in which a strain gauge element is disposed on the same diaphragm.

An object of the present invention is to provide a sensor which can be reduced in size and thickness and which has high manufacturing efficiency, and a method for manufacturing the sensor.

[0009]

The sensor according to the present invention comprises:
A sensor provided with a sensor chip for arranging a strain gauge element on a diaphragm and detecting a physical quantity of the diaphragm to convert it to an electric signal, wherein a diaphragm surface on which the strain gauge element is arranged is provided via a bump. A flexible substrate is provided, and the flexible substrate is provided with an electronic circuit for processing the electric signal. Here, the flexible substrate refers to a flexible substrate that can be printed and wired and can be wound into a roll, for example, polyester,
A polyimide substrate can be used. In addition, the bump means not only an element for electrically connecting the strain gauge element formed on the diaphragm surface and the electronic circuit board, but also for physically bonding and fixing the sensor chip and the flexible board. For example, gold bumps, solder bumps, and the like can be considered.

According to the present invention, since the electrical connection between the electronic circuit on the flexible substrate and the strain gauge element on the diaphragm is made by bump bonding, all the electrodes are connected by die bonding regardless of the number of electrodes. The connections can be made at once and at high speed, and the manufacturing time of the sensor can be greatly reduced. Also, in the case of bump bonding, it is possible to make electrical connection by making the distance between the flexible substrate and the sensor chip closer as compared with the case of wire bonding, so that the sensor can be downsized,
It is possible to reduce the thickness.

[0011] In the above, it is preferable that at least one notch formed from the outer periphery toward the inside is formed in the above-mentioned flexible substrate. Here, the notch is provided so that stress is not generated at a joint portion between the electronic circuit board and the sensor chip by the bump due to thermal expansion due to a temperature change of the sensor chip, and the notch is formed according to the position and location of the joint portion by the bump. It is preferable to set the location and location of the notch. As described above, if the notch is formed in the flexible substrate, even if the sensor chip expands and contracts due to a temperature change of the measurement fluid or the like, and a movement occurs with the flexible substrate, the movement is absorbed by the notch. As a result, the stress acting on the bump joint is reduced, and the bump joint can be maintained in a good state for a long time.

Preferably, the above-mentioned flexible substrate is provided with an adjustment trimming pad for correcting an electric signal output according to the physical quantity of the diaphragm. In other words, since the trimming pad for adjustment is provided on the flexible substrate, it is possible to immediately perform zero adjustment and span adjustment of the sensor after electrically connecting the flexible substrate and the sensor chip by bump bonding. The adjustment of the sensor can be completed at the same time in the manufacturing process including the above, and a highly accurate sensor can be efficiently manufactured.

Further, the above-mentioned electronic circuit is preferably covered with a molding agent. Here, it is preferable to employ a synthetic resin material such as an epoxy resin or a silicone resin as the molding agent. That is, since the electronic circuit is covered with the molding compound, the portion for processing the electric signal is protected by the molding compound, and the durability of the sensor is improved, and in particular, the vibration resistance is improved. Although it is conceivable to use a gold bump as the above-described bump, it is preferable to use a solder bump made of an alloy of tin and lead. That is, solder can be obtained at a very low price as compared with gold or the like, so that the material cost of forming the sensor is reduced and the manufacturing cost of the sensor is reduced.

Next, a method for manufacturing a sensor according to the present invention is as follows.
A sensor chip for arranging a strain gauge element on the diaphragm to detect a physical quantity of the diaphragm and converting it into an electric signal; a flexible substrate provided via bumps on a diaphragm surface on which the strain gauge element is arranged; A method of manufacturing a sensor comprising: an electronic circuit provided on a substrate; and a first step of providing the electronic circuit on the flexible substrate, and the flexible substrate and the electronic circuit are mounted on the diaphragm by the bumps. The method is characterized by comprising a second step of joining and a third step of covering the electronic circuit with a molding agent. That is, according to the present invention, since the flexible substrate is employed as the substrate on which the electronic circuit is provided, the TAB (Tape Automated B) is used.
Using the bonding technology, it is possible to continuously mount an electronic circuit on a substrate and to join a sensor chip and a flexible substrate, and it is possible to efficiently and quickly manufacture a sensor. .

[0015] In the above, usually, after an integrated electronic circuit such as an IC is bump-bonded on a flexible substrate, bump bonding between the flexible substrate and the sensor is performed.
The first step and the second step are performed by a bonding tool for simultaneously performing bump bonding of the flexible substrate and the sensor chip.
It is good to be able to complete the process of this at the same time. That is, 1
The bonding of the electronic circuit and the flexible substrate and the bonding of the flexible substrate and the pressure sensor chip can be completed at the same time by a simple bump bonding, which simplifies the sensor manufacturing process and reduces manufacturing equipment costs and manufacturing management costs. Thus, the manufacturing cost of the sensor can be reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In the following description, for the same or similar parts as the already described parts or members,
The description is omitted or simplified. FIG. 1 shows a first embodiment of the present invention.
1 shows a pressure sensor according to an embodiment. In the conventional pressure sensor 7 described in the background art, the electronic circuit board 73 includes:
The outer peripheral portion is supported by the joint member 11, and the electrical connection between the electronic circuit board 73 and the pressure sensor chip 12 is performed by the bonding wire 731. And
In order to perform wire bonding, a predetermined gap is provided between the sensor chip 12 and the electronic circuit board 73. On the other hand, in the pressure sensor 1 according to the first embodiment, the flexible substrate 13 is provided on the pressure sensor chip 12 via the bump 21, and the electrical connection between the flexible substrate 13 and the pressure sensor chip 12 is as follows. This is performed by the bump 21.

That is, as shown in FIGS. 2 and 3,
On the surface of the diaphragm 121 of the pressure sensor chip 12 where the strain gauge element 22 is disposed, a flexible substrate 13 is disposed via bumps 21. An IC 23 serving as an electronic circuit provided on the upper surface of the flexible substrate 13 has a gel-like shape. It is covered with a molding agent 24 made of silicone resin. On the upper surface of the diaphragm of the pressure sensor chip 12, as shown in FIG.
2, a pair of voltage application pads 251 and a pair of voltage output pads 252 to which the bumps 21 are bonded are formed.
Are formed. In addition, such a pressure sensor chip 1
2 is for forming polycrystalline silicon on the insulating film of silicon oxide by the CVD method on the diaphragm 121 and forming a gauge pattern of polycrystalline silicon by photoetching,
It is manufactured by forming a bridge circuit 25 connecting the respective strain gauge elements 22 by electron beam evaporation.

On the other hand, as shown in FIG. 3B, the flexible substrate 13 on which the IC 23 is mounted has a circular shape substantially the same as the planar shape of the pressure sensor chip 12, and the flexible substrate 13 has an outer periphery. Six notches 131 are formed from the portion toward the center of the circle inside, and a device hole 132 for mounting the IC 23 is formed in the center. Then, the flexible substrate 1 is formed by these notches 131.
3 is divided into six regions, and among the six regions, four regions 133 have bump holes 1 through which the bumps 21 are inserted.
34 are provided.

Of the remaining two regions except the four regions 133, three pads 136 to which the above-described lead wires 732 are connected are formed in the lower left region 135 in FIG. Of these, two are pads for power supply for supplying power to the IC 23 and the like, and the remaining one is a pad for external output. In the upper right area 137 in FIG. 3B, four adjustment trimming pads 138 for performing zero adjustment and span adjustment of the pressure sensor 1 are provided. These four adjustment trimming pads 138
Is used as an adjustment terminal for inputting and outputting sample data to perform zero adjustment and span adjustment. Here, although not shown in FIG. 3, printed wiring is provided on the surface of the flexible substrate 13, and the above-described bump holes 134, power supply and external output pads 136, and adjustment trimming pads 138 are connected to the device. It is electrically connected to bonding leads formed in the holes 132 (FIG. 3).
(Not shown in (B)).

As described above, the notch 131 that divides the flexible substrate 13 into six regions 133, 135, and 137
A groove 131A having a predetermined width from the outer peripheral portion of the flexible substrate 13 toward the center of the circle;
1A, and a circular portion 131B formed at the inner front end portion. The width of the groove 131A and the radius of the circular portion are determined by the magnitude of the coefficient of thermal expansion of the pressure sensor chip 12 due to the temperature change, the softness of the flexible substrate 13,
It is appropriately changed according to the bonding strength of the above.

The flexible substrate 13 having the above configuration
As shown in the exploded perspective view of FIG. 4, bumps 21 are formed on the upper surface of the diaphragm 121 of the pressure sensor chip 12 described above.
Is fixed by joining. That is, the diaphragm 12
The bumps 21 are correspondingly arranged on the voltage application pads 251 and the voltage output pads 252 formed on the upper surface of the first substrate 1, and the bump holes 134 of the flexible substrate 13 are aligned with the arrangement of the bumps 21. As a result, the flexible substrate 13 is
21 is fixed to the upper surface. Here, the bump 21 is made of tin,
Bump 2 composed of a solder material composed of a lead alloy
1 by hot press welding, the physical bonding of the flexible substrate 13 is performed, and the voltage application pad 251 and the voltage output pad 252 are
Are electrically connected to the bump holes 134, and are further electrically connected to the ICs 23 by printed wiring (not shown in FIG. 4) formed on the flexible substrate 13.

Next, a processing apparatus for bonding the flexible substrate 13 on the pressure sensor chip 12 by the bumps 21 will be described with reference to FIGS. As shown in FIG. 5, the processing device 3 includes a first process forming a first process.
Bond part 31 and second bond part 3 constituting the second step
2, a molding part 33 constituting a third step,
A flexible tape 13 serving as a supply source of the flexible substrate 13; a take-up reel 35 for taking up remaining material; and a reversing roller 3 for reversing a polyimide tape 341 described later.
6 is included.

On the flexible tape reel 34, a belt-shaped polyimide tape 341 having a predetermined width, which is a constituent material of the flexible substrate 13, is wound in a roll shape. As shown in FIG. 6A, the flexible substrate 13 is formed on the surface of the polyimide tape 341 by punching in advance, and is connected to other portions of the polyimide tape 341 at four peripheral end portions. In addition, polyimide tape 341
At the same time, the device holes 132,
The bump hole 134 and the notch 131 are also formed at the same time, and the above-described power supply / external output pad 136 and adjustment trimming pad 138 are formed by vapor deposition. Also, a bonding lead wire is formed in the device hole 132 at the same time, and a bump for bonding the IC 23 to the bump is provided at the tip thereof.

The first bonding portion 31 is a step of mounting the IC 23 on the polyimide tape 341 as shown in FIG. 6B, and the flexible substrate 13 formed on the surface of the polyimide tape 341 and the IC 23 are bump-bonded. And a first bonding tool 312 for pressing the flexible substrate 13 from above during bump bonding. The heating tool 311 is shown in FIG.
Although not shown in (B), an IC mounted on the upper surface thereof
A heater for heating the IC 23 is provided, and a mechanism for continuously supplying the IC 23 according to the supply speed of the polyimide tape 341 is provided. The supply mechanism of the IC 23 includes a flexible substrate such as a TAB or the like.
A known supply mechanism similar to the supply mechanism normally used for C mounting is employed. First bonding tool 3
Numeral 12 is provided so as to be able to advance and retreat with respect to the heating tool 311. By pressing the flexible substrate 13 with the first bonding tool 312, the bump formed in the device hole 132 and the terminal of the IC 23 are joined.

As shown in FIG. 5, the second bond portion 32
In this step, the flexible substrate 13 on which the IC 23 is mounted is bump-bonded on the pressure sensor chip 12 and the flexible substrate 13 is separated from another portion of the polyimide tape 341, that is, the remaining material.
21 and a second bonding tool 322.
Although not shown in FIG. 5, the heating tool 321 of the second bonding portion 32 has a pressure sensor chip manufactured in a separate process in advance according to the supply speed of the polyimide tape 341 to the second bonding portion 32. A mechanism capable of continuously supplying 12 is provided. As the continuous supply mechanism, a known one substantially similar to the one provided in the heating tool 311 of the first bond portion described above is used. Further, the second bonding portion 32 is also provided with a mechanism for supplying the bump 21 for bump bonding the flexible substrate 13 and the pressure sensor chip 12. Then, the remaining material of the polyimide tape 341 from which the flexible substrate 13 has been cut off is wound up by the take-up reel 35 described above.

The molding part 3 constituting the third step
3, a mounting table 331 for mounting the pressure sensor chip 12 and a nozzle 332 for supplying a molding agent 24 made of a gel silicone resin to the flexible substrate 13 on the pressure sensor chip 12, as shown in FIG. It is comprised including. The mounting table 331 is not shown in FIG.
A mechanism for continuously supplying the pressure sensor chip 12 to the nozzle 332 is provided, and when the molding agent 24 is supplied by the nozzle 332, the pad 136 for power supply and external output and the trimming pad 138 for adjustment are connected to the molding agent 2.
A mechanism for preventing the diffusion of the molding agent 24 is provided so that the molding agent 24 is not covered with the molding agent 4.

Next, a procedure for manufacturing the pressure sensor 1 using the above-described processing apparatus 3 will be described. Flexible tape reel 34 by first bonding portion 31
Bonding between the flexible substrate 13 and the IC 23 on the polyimide tape 341 which is continuously supplied from the semiconductor device. Since the flexible substrate 13 is not separated from the polyimide tape 341, the polyimide tape 341 is sent to the reversing roller 36 together with the IC 23, and is reversed by the reversing roller 36 so that the mounting surface of the IC 23 becomes the upper surface.

After being reversed by the reversing roller 36, the polyimide tape 341 is
And the second bonding tool 322 performs bump bonding between the pressure sensor chip 12 and the flexible substrate 13. At the same time, a portion of the outer periphery of the flexible substrate 13 that is connected to another portion of the polyimide tape 341 is cut by a cutter formed on the peripheral portion of the second bonding tool 322 (not shown in FIG. 5). After the bump bonding between the pressure sensor chip 12 and the flexible substrate 13, the upper part of the IC 23 is covered with a mold agent 24 and cured until it reaches a predetermined hardness.

After fixing the pressure sensor chip 12 via the support 15 on the joint member 11 manufactured in another process, the lead 732 is connected to the pad 136 by wire bonding with the relay board 733, and the pad 136 is adjusted. An adjustment device that inputs and outputs sample data is connected to the trimming pad 138. After performing zero adjustment and span adjustment with the adjustment device,
After removing the adjusting device, the case 14 and the joint member 11 are removed.
And the pressure sensor 1 is completed. The method of using the pressure sensor 1 thus manufactured and the method of measuring the pressure are as follows.
The description is omitted because it is the same as the conventional pressure sensor 7 described in the background art.

According to the first embodiment described above, the following effects can be obtained. That is, the IC 23 on the flexible substrate 13 and the strain gauge element 22 on the diaphragm 121
Is electrically connected to the bridge circuit 25 constituted by the bumps 21 by bump bonding of the bumps 21. Therefore, the number of electrodes, that is, the pads 251, 25
All the electrodes can be connected at once and at high speed regardless of the number of 2, and the manufacturing time of the pressure sensor 1 can be greatly reduced.

When the electrical connection between the electronic circuit board 73 and the pressure sensor chip 12 is made by wire bonding as in the conventional pressure sensor 7, the electronic circuit board 7
3. Since the distance between the pressure sensor chips 12 must be secured to some extent, there is a limit to reducing the height H0 of the case 74. On the other hand, in the pressure sensor 1 according to the first embodiment, since the electrical connection is made by the bumps 21, the distance between the flexible substrate 13 and the pressure sensor chip 12 can be made closer, as can be seen from FIG. In addition, the height H1 of the case can be reduced, and the size and thickness of the pressure sensor 1 can be reduced. Note that, specifically, in comparison with the height H0 of the case of the conventional pressure sensor 7, in the pressure sensor 1 according to the first embodiment, the height H1 of the case is reduced by approximately 5 mm.

Further, since a plurality of cutouts 131 are formed in the flexible substrate 13 in accordance with the arrangement of the bumps 21, the pressure sensor chip 12 expands and contracts due to a temperature change of a measurement fluid or the like, and the flexible substrate 13 Can be absorbed by the notch 131, the stress acting on the bump joint can be reduced, and the bump joint can be maintained in a good state for a long period of time. be able to. Since the trimming pad 138 for adjustment is provided on the flexible substrate 13, the zero adjustment and the span adjustment of the pressure sensor 1 can be performed immediately after the manufacturing, as shown in the manufacturing procedure of the pressure sensor 1. Pressure sensor 1 at the same time in the manufacturing process including bonding
Is completed, and the highly accurate pressure sensor 1 can be efficiently manufactured.

Further, since the upper surface of the flexible substrate 13 is covered with the molding compound 24, the IC 23 for processing an electric signal can be covered and protected, and the durability of the pressure sensor 1 is improved. Is improved. Further, since solder is used as the material of the bumps 21, material costs can be reduced as compared with gold bumps and the like, and manufacturing costs of the pressure sensor 1 can be reduced.

Since the flexible substrate 13 is employed as the substrate on which the IC 23 is provided, as shown in the manufacturing procedure of the pressure sensor 1, the IC 23 is mounted on the flexible substrate 13 by using the TAB technique (see FIG. The first bonding portion 31) and the bonding between the pressure sensor chip 12 and the flexible substrate 13 (the second bonding portion 32) can be continuously performed, and the pressure sensor 1 can be manufactured efficiently and quickly.

Next, a second embodiment of the present invention will be described. In the method of manufacturing the pressure sensor 1 according to the first embodiment, the pressure sensor chip 12 and the flexible substrate 13
In the processing device 3 for bump bonding between the flexible substrate 13 and the IC 23 at the first bond portion 31, bump bonding between the flexible substrate 13 and the pressure sensor chip 12 is performed at the second bond portion 32. Was. On the other hand, in the manufacturing method of the pressure sensor 1 according to the second embodiment, as shown in FIG. 7, in the processing device 5 for bump bonding the pressure sensor chip 12 and the flexible substrate 13, the IC 23 and the flexible substrate 13 Bump bonding, pressure sensor chip 12 and flexible substrate 13
The difference from the above-mentioned bump bonding is that both are completed at the same time by one bond portion 51.

The bonding portion 51 includes a heating tool 511 and a bonding tool 512. The heating tool 511 includes a supply mechanism for the pressure sensor chip 12 and a supply mechanism for the IC 23, which are not shown in FIG. These supply mechanisms have substantially the same structure as the supply mechanisms provided in the heating tools 311 and 321 described in the first embodiment. Further, the flexible substrate 1 is provided in the bond portion 51.
Bump 2 for bonding bump 3 to pressure sensor chip 12
1 is also provided (not shown in FIG. 7).

The bonding tool 511 is shown in FIGS.
As shown in FIG. 5, an IC pressing portion 512A for pressing the IC 23 from above is formed on the end face thereof, and a bump pressing portion 512B is formed on a portion corresponding to the arrangement of the bump 21 in order to heat-press weld the bump 21. Are formed. A ring-shaped cutter 512C protruding in the pressing direction is provided on the outer periphery of the bonding tool 512.
Is formed, and the flexible substrate 13 is bonded to the polyimide tape 341 by the cutter 512C at the same time as the bump bonding.
Disconnected from

The processing device 5 causes the pressure sensor chip 12
When performing the bump bonding between the flexible tape 13 and the flexible substrate 13, the polyimide tape 341 is continuously supplied from the flexible tape reel 34, and the pressure sensor chip 1 is
2. The flexible substrate 13 and the IC 23 are simultaneously pressed by the bonding tool 512 to perform bump bonding. Thereafter, the pressure sensor 1 is manufactured in the same procedure as the manufacturing procedure of the first embodiment.

According to the above-described second embodiment, the following effects are obtained in addition to the effects of the first embodiment. That is, the flexible substrate 1 is formed only by the bonding portion 51.
3 and the IC 23 and the bonding of the flexible substrate 13 and the pressure sensor chip 12 are completed at the same time, so that equipment such as the reversing roller 36 is not required unlike the processing apparatus 3 in the first embodiment, and the pressure sensor 1 The manufacturing process can be simplified, and the manufacturing cost of the pressure sensor 1 can be reduced by reducing manufacturing equipment costs and manufacturing management costs.

The present invention is not limited to the above embodiments, but includes the following modifications. That is, in each of the above-described embodiments, the present invention has been adopted for the pressure sensor 1. However, the present invention is not limited to this, and a flow sensor, an acceleration sensor, It may be. In each of the above embodiments, polyimide is used as the material of the flexible substrate 13. However, the present invention is not limited to this, and the present invention may be applied to a flexible substrate made of polyester. In short, the material, shape, dimensions, and the like of the flexible substrate may be appropriately determined according to the required performance, such as being capable of being wound up in a roll shape and being capable of forming printed wiring on the surface.

Further, in the first embodiment described above, the bump 21 is made of a solder material, but is not limited to this, and a gold bump or the like may be used. In short, the material of the bump may be appropriately determined according to the use condition of the sensor, the exposure condition, and the like. In the above-described embodiment, a gel silicone resin is used as the material of the molding agent 24. However, the present invention is not limited to this, and an epoxy resin may be used. In addition, specific structures, shapes, and the like when the present invention is implemented may be other structures and the like as long as the object of the present invention can be achieved.

[0042]

According to the sensor of the present invention as described above,
Since the flexible substrate is provided on the sensor chip via the bump, the distance between the sensor chip and the flexible substrate can be reduced to reduce the size and thickness of the sensor. Further, since a flexible substrate is used as a substrate on which the electronic circuit is provided, continuous production by TAB can be performed, and the production efficiency of the sensor can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a sensor according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a structure of a sensor chip and a flexible substrate according to the embodiment.

FIG. 3 is a top view of a sensor chip and a flexible substrate in the embodiment described above.

FIG. 4 is an exploded perspective view showing a joint structure between a sensor chip and a flexible substrate in the embodiment described above.

FIG. 5 is a schematic view illustrating a processing apparatus for realizing the sensor manufacturing method according to the embodiment.

FIG. 6 is a schematic diagram illustrating a first step of the processing apparatus according to the embodiment.

FIG. 7 is a partial cross-sectional view illustrating a main part of a method for manufacturing a sensor according to a second embodiment of the present invention.

FIG. 8 is a plan view illustrating a pressing surface of a second bonding tool used in a second step in the above-described embodiment.

FIG. 9 is a cross-sectional view illustrating a conventional pressure sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Sensor (pressure sensor) 12 Sensor chip 13 Flexible board 21 Bump 22 Strain gauge element 23 Electronic circuit (IC) 24 Molding agent 31 1st process (1st bond part) 32 2nd process (2nd bond part) 33 Third Step (Molding Section) 51 Bonding Section 121 Simultaneously Performing First Step and Second Step 121 Diaphragm 131 Notch Section 138 Trimming Pad for Adjustment 512 Bonding Tool

Claims (7)

[Claims] 1. A sensor comprising a sensor chip for arranging a strain gauge element on a diaphragm and detecting a physical quantity of the diaphragm to convert the physical quantity into an electric signal, wherein a surface of the diaphragm on which the strain gauge element is arranged is provided. A flexible substrate provided via a bump, and the flexible substrate is provided with an electronic circuit for processing the electric signal. 2. The sensor according to claim 1, wherein the flexible substrate has at least one notch formed from the outer periphery toward the inside of the flexible substrate. 3. The sensor according to claim 1, wherein the flexible substrate is provided with an adjustment trimming pad for correcting the electric signal output according to a physical quantity of the diaphragm. A sensor characterized by the above-mentioned. 4. The sensor according to claim 1, wherein the electronic circuit is covered with a molding agent. 5. The sensor according to claim 1, wherein the bump is a solder bump made of an alloy of tin and lead. 6. A sensor chip for arranging a strain gauge element on a diaphragm to detect a physical quantity of the diaphragm and converting it into an electric signal, and a flexible member provided via bumps on a surface of the diaphragm on which the strain gauge element is arranged. A method for manufacturing a sensor comprising a substrate and an electronic circuit provided on the flexible substrate, comprising: a first step of providing the electronic circuit on the flexible substrate; And a third step of covering the electronic circuit with a mold agent. 7. The method for manufacturing a sensor according to claim 6, wherein the electronic circuit is bonded to the flexible substrate by a bump, and the electronic circuit and the flexible substrate are bonded to each other by a bump. The first bonding method is performed by a bonding tool that performs bump bonding at the same time.
And a step of performing the second step simultaneously.