JP2005207993A - Bearing pressure distribution sensor, and manufacturing method for bearing pressure distribution sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing pressure distribution sensor with a simple composition capable of carrying out accurate and stable detection of bearing pressure distribution throughout a long term, which can be manufactured at a low cost. <P>SOLUTION: The bearing pressure distribution sensor is characterized by that it has a pair of substrates 8 and 9 facing each other on both sides of a fluid layer 10, a row wiring group 2 comprising a plurality of linear conductors 2a arranged and formed in a fluid layer 10 side of one substrate 8, and a column wiring group 3 comprising a plurality of different linear conductors 3a arranged and formed in a fluid layer 10 side of the other substrate 9, the linear conductors 2a and the different linear conductors 3a are arranged so as to alternately cross, electrostatic capacity is formed in each crossing part of each linear conductor 2a and 3a, the row wiring group 2 is embedded in one substrate 8, and the linear conductors 2a comprising the row wiring group 2 are retreated to a side more away from the fluid layer 10 than a fluid layer facing face 8a of the one substrate 8. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a surface pressure distribution sensor and a method for manufacturing the same, and more particularly to a surface pressure distribution sensor suitably used for measuring fine irregularities such as fingerprints and a method for manufacturing the same.

  A surface pressure distribution sensor that detects fine unevenness on the surface of an object to be measured pressed against a detection surface as a distribution of pressing force is known as a sensor that converts the surface shape of a rough surface into data (for example, Patent Documents). 1).

The surface pressure distribution sensor described in Patent Document 1 is a so-called pressure-sensitive sensor. For example, as shown in FIG. 15, semiconductor switching elements 201 arranged in a matrix on a semiconductor substrate and the semiconductor switching elements 201 are arranged. ..., an electrode 202 connected to one terminal side is formed. On the opposite surface side of the semiconductor substrate, a flexible film having a conductive film is disposed so as to face the electrode with a certain distance from the electrode side. A constant voltage is applied to the conductive film.
For example, when an object to be measured having fine irregularities on the surface is pressed against the flexible film, the flexible film bends following the irregularities of the object to be measured, and the conductive film in the bent portion and the electrode of the semiconductor substrate Are in contact with each other, and the matrix of semiconductor switching elements in that portion is sequentially activated and read.
Japanese Examined Patent Publication No. 7-58234

  Conventional pressure-sensitive surface pressure distribution sensors use semiconductor substrates, but such semiconductor substrates are generally expensive. In particular, when a surface pressure distribution sensor is used as a fingerprint detection sensor, a large surface area for sufficiently pressing a finger is required, and it is difficult to manufacture at low cost as long as a semiconductor substrate having such a large surface area is used. In addition, in order to detect minute irregularities on the surface, the exposed portion of the semiconductor switching element and the conductive film must be kept in stable contact even with a small pressing force over a long period of time. In the sensor, it is difficult to maintain the cleanliness of the contact portion between the exposed portion of the semiconductor switching element and the conductive film over a long period of time.

  Recently, a capacitive surface pressure distribution sensor has been proposed instead of the pressure-sensitive type. The capacitive surface pressure distribution sensor includes a plurality of row wirings provided on a flexible substrate and a plurality of column wirings provided on another substrate so as to intersect each row wiring. ing. Capacitance is formed at the intersection of the row wiring and the column wiring. And it is comprised so that the change of the electrostatic capacitance accompanying the bending of a flexible substrate may be detected and distribution of surface pressure may be measured. In this capacitive surface pressure distribution sensor, an insulating film is laminated on either the row wiring or the column wiring for the purpose of preventing contact between the row wiring and the column wiring.

  However, the provision of the insulating film has a problem that the structure of the surface pressure distribution sensor is complicated. Further, when the film thickness of the insulating film varies, there is a problem that the sensitivity of the surface pressure distribution sensor varies and fine irregularities cannot be detected accurately. Furthermore, in order to form the insulating film, an expensive sputtering apparatus is required, and there is a problem that the cost of the surface pressure distribution sensor cannot be reduced.

  The present invention has been made in view of the above circumstances, and a surface pressure distribution sensor capable of accurately and stably detecting a surface pressure distribution over a long period of time and capable of being manufactured at a low cost with a simple configuration. It aims at providing the manufacturing method.

In order to achieve the above object, the present invention employs the following configuration.
The surface pressure distribution sensor according to the present invention includes a pair of substrates facing each other across a fluid layer, a row wiring group including a plurality of linear conductors formed in parallel on the fluid layer side of one substrate, and the other A column wiring group composed of a plurality of other linear conductors formed in parallel on the fluid layer side of the substrate, and arranged so that the linear conductor and the other linear conductor intersect each other Capacitance is formed at each intersection of the linear conductors, the row wiring group is embedded in the one substrate, and the linear conductor forming the row wiring group is the one substrate. The fluid layer is disposed so as to recede from the fluid layer facing surface to a side farther from the fluid layer.

According to the above configuration, when the object to be measured comes into contact with either one of the substrates or the other substrate, one of the substrates bends so that the linear conductor and the other linear conductor contact each other. Even if it is going to be done, the linear conductor is retracted and embedded in one substrate, so there is no risk of contact between the linear conductor and another linear conductor, and the change in capacitance is accurately detected. can do.
Moreover, since there is no possibility that a linear conductor and another linear conductor will contact, it is not necessary to form the insulating film for contact prevention.

  Moreover, the surface pressure distribution sensor of the present invention is the surface pressure distribution sensor described above, wherein the column wiring group is embedded in the other substrate, and the other linear conductor forming the column wiring group includes: The other substrate is disposed so as to recede to the side away from the fluid layer from the fluid layer facing surface of the other substrate.

  According to said structure, since another linear conductor is set back and embedded in the other board | substrate, a contact with a linear conductor and another linear conductor can be prevented reliably.

  In the surface pressure distribution sensor of the present invention, it is preferable that at least one of the one substrate and the other substrate is made of a flexible film. For example, when one substrate is a flexible film, the surface opposite to the fluid layer of the one substrate is a pressure-sensitive surface that detects the unevenness of the object to be measured.

  In the surface pressure distribution sensor of the present invention, the one and the other substrates may be made of a flexible substrate film, and the substrates may be connected via a refracting portion. With this configuration, the number of parts of the surface pressure distribution sensor can be reduced.

  Next, in the method for manufacturing a surface pressure distribution sensor according to the present invention, a plurality of line conductors and a plurality of other line conductors are arranged in parallel on one and the other substrates, respectively, to form row wiring groups and column wiring groups, respectively. And a method of manufacturing a surface pressure distribution sensor by crossing each of the linear conductors and the other linear conductors, and overlapping each substrate with a fluid layer interposed therebetween, Forming a row wiring group by arranging linear conductors in parallel; bonding the row wiring group to one substrate together with the smooth substrate; and embedding the linear conductor in the one substrate; And a step of etching the exposed surface of the embedded linear conductor so as to recede from the fluid layer facing surface of the one substrate after removing from the one substrate.

  According to the above configuration, the contact pressure between the opposing linear conductors does not come into contact with each other by pressing the row wiring group on one substrate and further etching and retracting the linear conductors forming the row wiring group. A distribution sensor can be easily formed. Moreover, it is not necessary to form an insulating film for preventing contact between the linear conductors.

As described above, according to the surface pressure distribution sensor of the present invention, there is no fear that a linear conductor and another linear conductor are in contact with each other, and a change in capacitance can be accurately detected. This also enables accurate and stable detection of the surface pressure distribution over a long period of time. Furthermore, since an insulating film for preventing contact is not required, a surface pressure distribution sensor that can be manufactured at a low cost with a simple configuration can be provided.
Further, according to the method for manufacturing a surface pressure distribution sensor of the present invention, it is possible to easily form a surface pressure distribution sensor that does not have a risk of contact between opposing linear conductors. Further, it is not necessary to form an insulating film for preventing contact between the linear conductors, and the manufacturing cost of the surface pressure distribution sensor can be greatly reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings described below are for explaining the configuration of the surface pressure distribution sensor, and the size, thickness, dimensions, etc. of each part shown in the drawings may differ from the dimensional relationship of the actual surface pressure distribution sensor. is there.

[First Embodiment]
FIG. 1 shows an equivalent circuit diagram of the surface pressure distribution sensor of the present embodiment, FIG. 2 shows an enlarged sectional view of the surface pressure distribution sensor of the present embodiment, and FIG. 3 shows the surface of the present embodiment. The equivalent circuit diagram of the capacity | capacitance detection circuit with which a pressure distribution sensor is equipped is shown.
As shown in FIG. 1, the surface pressure distribution sensor 1 of the present embodiment includes a row wiring group 2 in which a plurality of linear conductors 2a... Are arranged in parallel along the Y direction, and a plurality of other linear conductors 3a. Are formed in parallel in the X direction so as to cross the linear conductors 2a, and electrostatic capacitances 5 formed at the intersections 4 of the respective linear conductors 2a and 3a. It consists of and. The row wiring group 2 is connected to the capacitance detection circuit 6, and the column wiring group 3 is connected to the column selection circuit 7. The column selection circuit 7 connects all the conductors other than the linear conductor 3a selected at the time of capacitance measurement to the ground side.

  Next, as shown in FIG. 2, the surface pressure distribution sensor 1 according to the present embodiment includes a flexible film 8 (one substrate) and a support substrate 9 (the other substrate), an air layer 10 (fluid layer). It is roughly arranged to be arranged opposite to each other. Spacers 11 for holding the gap between the flexible film 8 and the support substrate 9 and for joining the flexible film 8 and the support substrate 9 are formed in the periphery of the flexible film 8 and the support substrate 9. Yes.

On the air layer facing surface 8a of the flexible film 8, a row wiring group 2 composed of a plurality of linear conductors 2a is formed. The linear conductors 2a are embedded in row wiring grooves 8b provided on the air layer facing surface 8a. An adhesive layer (not shown) is provided between the linear conductors 2a and the row wiring grooves 8b. Further, the thickness t ₁ of the linear conductors 2 a is smaller than the depth d _{1 of the} row wiring grooves 8 b. One surface 2a 1 _... each Thereby facing the linear conductors 2a ... air layer 10, than the air layer facing surface 8a of the flexible film 8 is disposed set back on the side remote from the air layer 10. As a result, recesses 8b ₁ ... Partitioned into one surface 2a ₁ ... Of linear conductors 2a.

The flexible film 8 only needs to be flexible enough to bend following the uneven shape when an uneven surface of about several μm is pressed on the surface. For example, a polyester film having a thickness of about 7 μm is preferable. Used for.
Moreover, the linear conductors 2a ..., for example the thickness _{t 1} is composed of 4μm about Cu film, it is sufficient on the flexible film 8, for example 50μm pitch 200 present formed. Furthermore row wiring groove 8b ..., as described below, row wire group 2 in which is formed when embedded in the flexible film 8, the depth d ₁ is set to, for example, about 5 [mu] m. The depth d ₂ of the recesses 8b ₁ ... Of the row wiring grooves 8b.
With the configuration as described above, the linear conductors 2a constituting the row wiring group 2 are arranged at substantially the center in the thickness direction of the flexible film 8.

  Next, a column wiring group 3 made up of a plurality of other linear conductors 3 a is formed on the air layer facing surface 9 a of the support substrate 9. The support substrate 9 only needs to have a rigidity that does not bend even when an uneven surface of about several μm is pressed against the flexible film 8. For example, a glass plate having a thickness of about 700 μm is preferably used. The other linear conductors 3a... Are made of, for example, a Cu film having a thickness of about 2 μm, and may be formed on the support substrate 9 at a pitch of 50 μm, for example.

  The spacer 11 is formed so as to go around the periphery of the row wiring group 2 and the column wiring group 3, and seals the air in the gap between the row wiring group 2 and the column wiring group 3 row wiring portion 11 facing each other, thereby forming the air layer 10. Form. Such an air layer 10 plays a role of bending the flexible film 8 following the uneven surface by the sealed air when a fine uneven surface is pressed against the surface of the flexible film 8. The air layer 10 in the gap between the row wiring group 2 and the column wiring group 3 does not have to be sealed, and the air layer facing surface 8a of the flexible film 8 is another linear conductor 3a on the support substrate 9. The air is sealed between the projections and depressions until it comes into close contact with the air, and plays the same role as when the air layer 10 is sealed.

  The surface pressure distribution sensor 1 of the present embodiment has a configuration as described above, and as shown in the equivalent circuit shown in FIG. 1, the separation distance between the intersecting portions 4 where the linear conductors 2a and 3a intersect. The capacitance detection circuit 6 can detect a change in the capacitances 5. In this way, the shape of the uneven surface of the object to be measured is detected by detecting the change in the capacitance of the multiple intersections 4... That occurs when the fine uneven surface is pressed against the surface of the flexible film 8. It can be output as signal data.

  For example, a circuit as shown in FIG. 3 is used as the capacitance detection circuit 6, and all of the capacitance detection circuits 6 other than the linear conductors 3 a... All non-measurement capacitance on the conductor 2a is input in parallel to the measurement system as parasitic capacitance, but can be canceled by connecting the electrode on the opposite side of the parasitic capacitance to the ground side. It has become. With such a configuration, it is possible to detect a minute uneven surface, that is, to detect a minute change in capacitance with high accuracy.

  In this embodiment, the row wiring group 2 is formed on the flexible film 8, but the column wiring group 3 may be formed on the flexible film 8. It is more preferable to form the column wiring group 3 connected to the column selection circuit 7 having a low output impedance on the flexible film 8 side because it is less susceptible to the influence of electrical noise.

  Such a surface pressure distribution sensor 1 is not limited in its application, but can also be used as a fingerprint sensor, for example, as shown in FIG. Electrostatic in accordance with the change in the separation distance at the intersection 4 between the linear conductor 2a and another linear conductor 3a, which is generated when fine irregularities 12 such as fingerprints are pressed against the surface of the flexible film 8. By detecting the change in the capacity, it becomes possible to accurately detect the shape of the fine unevenness 25 such as a fingerprint and output it as signal data.

Further, in the surface pressure distribution sensor 1 of the present embodiment, the linear conductor 2a is disposed so as to recede to the side farther from the air layer 10 than the air layer facing surface 8a of the flexible film 8, so Even if the air layer facing surface 8a is pressed against another linear conductor 3a by the pressing of 12, the linear conductors 2a and 3a are not in contact with each other. In particular, since the depth d ₂ of the recesses 8b ₁ ... Is set to about 1 μm, the contact between the linear conductors 2a and 3a can be reliably prevented even when the unevenness 12 having a size of a fingerprint is pressed. . Thereby, the change of the electrostatic capacitance 5 in the crossing part 4 can be measured accurately.

  As an example in which the surface pressure distribution sensor 1 of the present embodiment is applied to a fingerprint sensor, for example, as shown in FIG. 5, it can be applied to an owner authentication system of a mobile phone 13, for example. In recent years, it has been considered to make payments with the mobile phone 13 or the like, but by providing the mobile phone 13 with the surface pressure distribution sensor 1, the fingerprint pressed against the surface pressure distribution sensor 1 can be accurately detected, The owner can be correctly authenticated by collating with fingerprint data registered in advance.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to the drawings. In FIG. 6, the expanded sectional view of the surface pressure distribution sensor 21 of this embodiment is shown. Note that, among the components of the surface pressure distribution sensor 21 of the present embodiment, the same components as those of the surface pressure distribution sensor 1 of the first embodiment are denoted by the same reference numerals and detailed description thereof will be given. Omitted.
The difference between the surface pressure distribution sensor 21 of the present embodiment and the surface pressure distribution sensor 1 of the first embodiment is that the other substrate is formed of a flexible film, and the column wiring group is used as the flexible film. It is a point that is placed backward by embedding.

  As shown in FIG. 6, the surface pressure distribution sensor 21 of the present embodiment includes a flexible film 8 (one substrate) and another flexible film 29 (the other substrate) in which an air layer 10 (fluid). Layer) and are generally arranged so as to face each other. Spacers 11 are formed on the periphery of the flexible films 8 and 29 to maintain the distance between the flexible films 8 and 29.

  On the air layer facing surface 8a of the flexible film 8, a row wiring group 2 composed of a plurality of linear conductors 2a is formed. The flexible film 8 and the linear conductors 2a, etc. have the same configuration as that described in the first embodiment.

Next, on the air layer facing surface 29a of the flexible film 29, a column wiring group 23 composed of a plurality of other linear conductors 23a is formed. The linear conductors 23a are embedded in the column wiring grooves 29b provided on the air layer facing surface 29a. An adhesive layer (not shown) is provided between the linear conductors 23a and the column wiring grooves 29b. Moreover, the linear conductors 23a ... thickness _{t 2} of is smaller than the groove 29 b ... a depth _{d 3} column wire. Thus one surface 23a ₁ opposite to the linear conductors 23a ... air layer 10 is, than the air layer facing surface 29a of the flexible film 29 are arranged set back on the side remote from the air layer 10. As a result, the recesses 29b ₁ defined by the one surface 23a ₁ of the linear conductors 23a are formed in the column wiring grooves 29b.

The flexible film 29 only needs to have a rigidity that does not bend even when an uneven surface of about several μm is pressed against the flexible film 8. For example, a polyester film having a thickness of about 700 μm is preferably used. .
Moreover, the linear conductors 23a ..., for example the thickness _{t 2} is composed of 4μm about Cu film, it is sufficient 200 present is formed on a flexible film 29, for example, 50μm pitch. Further column wiring groove 29 b ... is intended to be formed when the column line group 2 is embedded in the flexible film 29, the depth d ₃ is set to, for example, about 5 [mu] m. The depth d ₄ of the recesses 29b _{1 of} the column wiring grooves 29b is set to about 1 μm.

  Similar to the surface pressure distribution sensor 1 of the first embodiment, the surface pressure distribution sensor 21 of the present embodiment has a configuration as described above, and is an intersection portion where the linear conductors 2a and 23a intersect. A change in capacitance according to a change in the separation distance can be detected. Thus, by detecting a change in capacitance that occurs when a fine uneven surface is pressed against the surface of the flexible film 8, the shape of the uneven surface of the object to be measured can be output as signal data. It becomes possible.

As shown in FIG. 7, in the surface pressure distribution sensor 21 of the present embodiment, the linear conductors 2 a and 23 a are respectively in the air layer 10 rather than the air layer facing surfaces 8 a and 29 a of the flexible films 8 and 29. Since the air layer facing surface 8a is pressed against the other air layer facing surface 29a by pressing the projections and depressions 12, the linear conductors 2a and 33a are in contact with each other. There is no fear. In particular, since the depths d ₂ and d _{4 of} the recesses 8b ₁ and 29b ₁ are set to about 1 μm, even if the air layer facing surfaces 8a and 29a are in contact with each other, the linear conductors 2a and 3a are about 2 μm. They are spaced apart and can reliably prevent contact. Thereby, the change of the electrostatic capacitance 5 in the crossing part 4 can be measured accurately.

Furthermore, according to the surface pressure distribution sensor 1 of the present embodiment, the row wiring group 2 is formed not on the air layer facing surface 8a of the flexible film 8 but on the side retreated from the air layer facing surface 8a. For this reason, the flexible film is positioned approximately in the center in the thickness direction. Thereby, there is no possibility that the flexible film 8 warps, the interval between the row wiring group 2 and the column wiring group 3 can be kept constant, and the unevenness can be detected accurately.
Furthermore, in the conventional capacitive surface pressure distribution sensor, the thickness of the conductors constituting the row wiring group had to be 1 μm or less. In the surface pressure distribution sensor 1 of the present embodiment, the row wiring group 2 is Since the thickness of the formed linear conductor 2a can be increased to several μm as compared with the prior art, the strength of the linear conductor 2a itself can be increased. Thereby, the linear conductor 2a itself can be provided with a spring property, and the resilience from the deformation of the flexible film 8 can be enhanced. Thereby, it can be clearly identified whether or not the object to be measured is in contact with the flexible film 8, and the responsiveness of the sensor can be improved.

[Third Embodiment]
Next, a method for manufacturing a surface pressure distribution sensor according to a third embodiment of the present invention will be described with reference to the drawings, taking the surface pressure distribution sensor 1 according to the first embodiment as an example.
The manufacturing method of the surface pressure distribution sensor of this embodiment includes a step of forming a row wiring group, a step of embedding the row wiring group in a flexible film, and an etching step.

First, in the step of forming a row wiring group, as shown in FIG. 8A, a highly smooth substrate 101 and a seed layer 102 laminated on the highly smooth substrate 101 are prepared. The highly smooth substrate 101 is a substrate with extremely high flatness whose surface roughness is set to 0.1 to 0.3 μm or less. For the seed layer 102, for example, a copper plating film having a thickness of about 2 μm can be used.
Next, as shown in FIG. 8B, a plating resist 103 made of a high resolution photoresist is formed in a region other than the row wiring group formation region on the seed layer 102.

  Next, as shown in FIG. 8C, a plurality of linear conductors 2a made of copper are formed in parallel by electroplating. Specifically, plating is performed by bringing the surface of the seed layer 102 not covered with the plating resist 103 into contact with an electrolytic copper plating solution. For example, a copper sulfate solution is used as the plating solution. As a result, the film thickness of the seed layer 102 in the row wiring group formation scheduled region is increased, and a plurality of linear conductors 2a arranged in parallel to each other after the plating resist 103 is removed remain. The thickness of the linear conductors 2a is preferably about 5 μm.

  Next, as shown in FIG. 8D, after the plating resist 103 is removed, the adhesive layer 104 is applied to the linear conductors 2a. The thickness of the adhesive layer 104 is preferably about 0.1 μm. In this way, the row wiring group 2 composed of the plurality of linear conductors 2a is formed on the smooth substrate 101.

Next, in the step of embedding the row wiring group in the flexible film, first, the flexible film 8 shown in FIG. 9A is prepared.
Next, as shown in FIG. 9B, the highly smooth substrate 101 provided with the row wiring group 2 is overlaid on the upper side of the flexible film 8. At this time, the row wiring group 2 is overlapped with the flexible film 8 facing each other. Further, another high smoothness substrate 105 is overlaid on the lower side of the flexible film 8. Another high smoothness substrate 105 is laminated with a seed layer 106 made of a copper plating film having a thickness of about 2 μm, and this seed layer 106 is overlaid so as to face the lower side of the flexible film 8.
Then, the flexible film 8 is sandwiched between the high smoothness substrates 101 and 105 and subjected to hot pressing (compression bonding). The temperature at the time of hot pressing depends on the material of the flexible film 8, but is preferably in the range of 140 to 180 ° C. The pressure of the hot press is preferably about 15 to 25 Pa. Further, the pressing time is preferably about 30 to 50 minutes. The row wiring group 2 is embedded in the flexible film by this hot pressing.

  Next, as shown in FIG. 9C, the high smoothness substrates 101 and 105 sandwiching the flexible film 8 are removed, and the seed layers 102 and 106 are also removed as shown in FIG. 9D. By removing the seed layer 102, the adhesive layer 104 laminated on the seed layer 102 is also removed at the same time. As a result, the linear conductors 2 a... Forming the row wiring group 2 are exposed on the upper surface of the flexible film 8.

Next, as shown in FIG. 9E, the linear conductors 2a ... exposed on the upper surface of the flexible film 8 are partially removed by wet etching. The wet etching is performed by applying an etchant solution such as a 10% ferric chloride aqueous solution on the upper surface of the flexible film 8. The wet etching is continued until the upper surfaces 2a ₁ of the linear conductors 2a are retracted about 1 μm from the upper surface of the flexible film 8. In this way, as shown in FIG. 9, the flexible film 8 in which the row wiring group 2 is embedded is obtained.

  Then, the support substrate on which the column wiring group is formed in advance and the flexible film 8 in which the row wiring group 2 is embedded are overlapped, and a spacer is formed around the row wiring group and the column wiring group for support. A surface pressure distribution sensor 1 as shown in FIG. 2 is obtained by bonding the substrate and the flexible film 8 together.

  In this embodiment, the row wiring group is formed on the flexible film and the column wiring group is formed on the support substrate. However, the column wiring group is formed on the flexible film and the row wiring group is formed on the support substrate. May be. The support substrate may be a glass plate or a flexible film having a relatively large thickness. Further, the row wiring group and the column wiring group may be formed on one flexible film, and then the flexible film may be bent so that the row wiring group and the column wiring group face each other.

  According to the manufacturing method of the surface pressure distribution sensor of this embodiment, the row wiring group is pressure-bonded and embedded on one substrate, and the linear conductors forming the row wiring group are further etched and retracted so as to face each other. It is possible to easily form a surface pressure distribution sensor that does not cause contact between conductors. Moreover, it is not necessary to form an insulating film for preventing contact between the linear conductors.

[Fourth Embodiment]
FIG. 10 is an enlarged cross-sectional view showing a surface pressure distribution sensor according to a fourth embodiment of the present invention. In the surface pressure distribution sensor 30 of the fourth embodiment, the column wiring group 31 and the row wiring group 32 are formed on one flexible film 33. That is, as shown in FIG. 11A, a large number of linear conductors 31a,..., 32a that extend in a direction perpendicular to each other are formed adjacent to each other on a single flexible film 33. Then, the column wiring 31 group and the row wiring 32 group may be formed so as to be bent by bending in the direction of the arrow P along the folding line L near the boundary between the column wiring group 31 and the row wiring group 32 ( (See FIG. 11B). The bent portion becomes a bent portion that connects the substrate on the column wiring group 31 side and the substrate on the row wiring group 32 side.

  In addition, as shown in FIG. 10, after bending one flexible film 33, a spacer 35 is formed to maintain a constant interval between the column wiring group 31 and the row wiring group 32 facing each other. preferable. Further, the row wiring group 32 side of the flexible film 33 may be bonded to a reinforcing plate 36, for example, a SUS plate.

  Furthermore, a rectangular reinforcing plate 37 may be formed on the column wiring group 31 side of the flexible film 33 so as to go around the periphery. Such a reinforcing plate 37 can also serve as a partition wall for guiding a detection-symmetrical finger to the surface pressure distribution sensor 30 when the surface pressure distribution sensor 30 is used for a fingerprint sensor, for example. Further, it is possible to provide flexibility by adjusting the plate thickness of the reinforcing plates 36 and 37 and to provide the surface pressure distribution sensor 30 in close contact with the curved surface.

[Fifth Embodiment]
When the row wiring group and the column wiring group are formed on one flexible film, for example, as shown in FIG. 12A, the column wiring group 41 and the row wiring group 42 are formed on one flexible film 40. It may be formed so as to extend in the same direction. First, the flexible film 40 in which the column wiring group 41 and the row wiring group 42 are formed so as to extend in the same direction is first bent along the oblique folding line A toward the upper left direction G1. .

  Next, the portion of the row wiring group 42 is folded back in the right direction G2 along the bending line B so that the row wiring group 42 extends in the lateral direction. Then, a portion of the column wiring group 41 is bent in the downward direction G3 along the folding line C, and overlapped with the row wiring group 42 so that the column wiring group 41 is orthogonal. As a result, as shown in FIG. 12B, the column wiring group 41 and the row wiring group 42 can be orthogonal to each other.

  In this way, if the column wiring group 41 and the row wiring group 42 are formed so as to extend in the same direction on the single flexible film 40, it is not necessary to circulate the wiring around the sensing portion, and the wiring is led to the terminal portion. And the extra margin of the flexible film 40 can be minimized.

[Sixth Embodiment]
The surface pressure distribution sensor can be formed integrally with the display device. As shown in FIG. 13, a column wiring group 52 is formed on a transparent flexible film 50 with a transparent conductive material such as ITO. Further, the row wiring group 51 is formed of a transparent conductive material such as ITO on a transparent substrate 55 made of, for example, a transparent polyester plate. If a liquid crystal display 56 or the like is formed below the transparent substrate 55, a display device 57 having a pointing function can be realized. If such a display device 57 is applied to, for example, a display unit of a mobile phone, a mobile phone having a pointing function can be realized in a small space.

[Seventh Embodiment]
The surface pressure distribution sensor of the present invention can also be used as a sensor for taking in the shadow of a seal, for example. As shown in FIG. 14, the unevenness of the shadow 62a formed on the seal 62 is pressed against the surface pressure distribution sensor 61, and the data of the shadow 62a is captured by a personal computer 63 or the like, which is used for various authentications and registration of a real seal. be able to.

FIG. 1 is a circuit diagram showing an equivalent circuit of a surface pressure distribution sensor according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of the surface pressure distribution sensor according to the first embodiment of the present invention. FIG. 3 is an equivalent circuit diagram illustrating an example of a capacitance detection circuit. FIG. 4 is an explanatory diagram illustrating a state when unevenness is detected by the surface pressure distribution sensor according to the first embodiment of the present invention. FIG. 5 is an external perspective view showing a mobile phone including the surface pressure distribution sensor according to the first embodiment of the present invention. FIG. 6 is an enlarged cross-sectional view of a surface pressure distribution sensor according to a second embodiment of the present invention. FIG. 7 is an explanatory diagram illustrating a state when unevenness is detected by the surface pressure distribution sensor according to the second embodiment of the present invention. FIG. 8 is a process diagram illustrating a method for manufacturing a surface pressure distribution sensor according to a third embodiment of the present invention. FIG. 9 is a process diagram illustrating a method for manufacturing a surface pressure distribution sensor according to a third embodiment of the present invention. FIG. 10 is an enlarged cross-sectional view showing a surface pressure distribution sensor according to a fourth embodiment of the present invention. FIG. 11 is an explanatory view showing the flexible film substrate of FIG. FIG. 12 is a schematic plan view showing a surface pressure distribution sensor according to a fifth embodiment of the present invention. FIG. 13 is an enlarged cross-sectional view showing a surface pressure distribution sensor according to a sixth embodiment of the present invention. FIG. 14 is an explanatory view showing a seventh embodiment of the present invention. FIG. 15 is an equivalent circuit diagram of a conventional surface pressure distribution sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 21 ... Surface pressure distribution sensor, 2 ... Row wiring group, 2a ... Linear conductor, 3, 23 ... Column wiring group, 3a, 23a ... Another linear conductor, 4 ... Intersection, 5 ... Capacitance, 8 ... Flexible film (one substrate), 8a, 29a ... Air layer facing surface (fluid layer facing surface), 9 ... Support substrate (other substrate), 10 ... Air layer (fluid layer), 29 ... Flexible Film (the other substrate), 101 ... high smooth substrate (smooth substrate)

Claims (5)

A pair of substrates facing each other across the fluid layer, a row wiring group consisting of a plurality of linear conductors formed in parallel on the fluid layer side of one substrate, and the fluid layer side of the other substrate in parallel A plurality of other linear conductors formed in a row, and arranged such that the linear conductor and the other linear conductor intersect with each other, and each intersection of the linear conductors. Capacitance is formed in the part,
The row wiring group is embedded in the one substrate, and the linear conductors forming the row wiring group are disposed so as to recede from the fluid layer facing surface of the one substrate to the side away from the fluid layer. A surface pressure distribution sensor.   The column wiring group is embedded in the other substrate, and the other linear conductor forming the column wiring group is retracted to a side farther from the fluid layer than the fluid layer facing surface of the other substrate. The surface pressure distribution sensor according to claim 1, wherein the surface pressure distribution sensor is arranged.   The surface pressure distribution sensor according to claim 1, wherein at least one of the one substrate and the other substrate is made of a flexible film.   The surface pressure distribution sensor according to claim 1 or 2, wherein the one and the other substrates are made of a flexible substrate film, and each substrate is connected via a refracting portion. A plurality of line conductors and a plurality of other line conductors are respectively arranged in parallel on one and the other substrate to form a row wiring group and a column wiring group, respectively, and the linear conductor and the another linear conductor, Is a method of manufacturing a surface pressure distribution sensor by overlapping each substrate with a fluid layer interposed therebetween,
A step of arranging a plurality of the linear conductors in parallel on a smooth substrate to form a row wiring group, and the row wiring group is pressure-bonded to one substrate together with the smooth substrate, so that the linear conductor is attached to the one substrate. And a step of removing the smooth substrate from the one substrate and then etching the exposed surface of the embedded linear conductor so as to recede from the fluid layer facing surface of the one substrate. A method of manufacturing a surface pressure distribution sensor.

Images