JP6561675B2 - Sensor inspection method and sensor inspection apparatus - Google Patents

Description

  The present invention relates to a sensor inspection method and a sensor inspection apparatus for inspecting the output of a sensor.

  Conventionally, various sensor inspection methods for inspecting sensor output have been proposed. After the sensor is manufactured, it must be inspected for proper output before being mounted on an electronic device. For example, Patent Document 1 discloses a plate-like sensor in which a first electrode and a second electrode are provided on both sides of a polymer piezoelectric film (hereinafter referred to as a piezoelectric film), and an inspection method for the sensor. Yes.

  In the inspection method of Patent Document 1, both ends of the lower surface of the sensor are fixed, and the center of the upper surface of the sensor is pressed. Thereby, the piezoelectric film is bent in the thickness direction, and electric charges are generated in the first electrode and the second electrode of the piezoelectric film. This sensor detects a pressure and a pressing amount by detecting a voltage generated between the first electrode and the second electrode of the piezoelectric film.

  The inspection method of Patent Document 1 can inspect whether proper output is performed by detecting the voltage output by this sensor.

JP-A-5-102548

  However, since the inspection method of Patent Document 1 presses the center of the upper surface of the sensor, the sensor may be damaged. Therefore, in the conventional sensor inspection method, even if the sensor is manufactured as a non-defective product, it may fail due to the inspection of the output.

  The objective of this invention is providing the sensor test | inspection method and sensor test | inspection apparatus which can test | inspect an output, without damaging a sensor.

  The sensor inspection method of the present invention includes an adsorption process, a bending process, and a measurement process. In the adsorption process, the sensor is adsorbed on the adsorption member. In the bending step, the adsorption member is bent. In the measurement step, the output of the sensor that is bent by the bending of the suction member is measured.

If the suction member bends in this bending step, the sensor also bends. The sensor outputs according to the amount of deflection. Therefore, this sensor inspection method can measure the output of the sensor without pressing the sensor.
Therefore, this sensor inspection method can inspect the output without damaging the sensor.

  In the present invention, it is preferable that the bending step presses a second area other than the first area where the sensor is adsorbed on the surface of the adsorbing member.

When the second region of the adsorption member is pressed in this bending step, the sensor is also bent. The sensor outputs according to the amount of deflection. Therefore, this sensor inspection method can measure the output of the sensor without pressing the sensor.
Therefore, this sensor inspection method can inspect the output without damaging the sensor.

  In the present invention, the sensor is a piezoelectric sensor, and the measurement step preferably measures a voltage output from the sensor.

  In the present invention, the number of sensors is preferably plural.

  In this method, the adsorption step causes a plurality of sensors to be adsorbed to the adsorption member. In the measurement step, the output of each sensor that is bent by the bending of the suction member is measured. Therefore, this sensor inspection method can simultaneously inspect the outputs of a plurality of sensors.

  Moreover, the sensor inspection apparatus of this invention is provided with an adsorption | suction member, a bending mechanism, and a measurement part. The adsorbing member adsorbs the sensor. The bending mechanism bends the adsorption member. A measurement part measures the output of the sensor which bends when an adsorption member bends.

  The sensor inspection apparatus having this configuration performs the sensor inspection method. Therefore, the sensor inspection apparatus having this configuration also has the same effect as the sensor inspection method.

  The sensor inspection method and sensor inspection apparatus of the present invention can inspect the output without damaging the sensor.

It is a top view of the piezoelectric sensor 100 test | inspected with the 1st test | inspection method of embodiment of this invention. It is sectional drawing of the AA line shown in FIG. It is a top view of the piezoelectric film 31 with which the sensor part 16 of the piezoelectric sensor 100 shown in FIG. 1 is equipped. It is a top view of the sensor test | inspection apparatus 15 used with the 1st test | inspection method of embodiment of this invention. It is sectional drawing of the BB line shown in FIG. It is sectional drawing of the BB line which shows a mode that a part of adsorption | suction board 150 shown in FIG. 4 is pressed. It is a top view of the test | inspection apparatus 25 used with the 2nd test | inspection method of other embodiment of this invention.

Hereinafter, the 1st inspection method of the embodiment of the present invention is explained. First, the piezoelectric sensor inspected by the first inspection method will be described.
FIG. 1 is a plan view of a piezoelectric sensor 100 to be inspected by the first inspection method according to the embodiment of the present invention. 2 is a cross-sectional view taken along line AA shown in FIG. FIG. 3 is a plan view of the piezoelectric film 31 provided in the sensor unit 16 of the piezoelectric sensor 100 shown in FIG.

  As shown in FIG. 1, the piezoelectric sensor 100 includes a sensor unit 16, a component mounting unit 38, and a circuit component 39. The component mounting unit 38 is a part of the flexible printed circuit board 30. As shown in FIGS. 1 and 2, the flexible printed circuit board 30 includes a board part 36, a board part 37, and a component mounting part 38. The material of the flexible printed circuit board 30 is a resin such as polyimide.

  A first terminal 32 and a second terminal 33, which are conductor patterns, are formed on the front main surface of the component mounting portion 38. Further, the circuit component 39 and the output terminal 390 are mounted on the front main surface of the component mounting portion 38.

  As shown in FIGS. 1 and 2, the first end of the first terminal 32 is connected to the first detection electrode 34. On the other hand, the second end of the first terminal 32 is connected to the circuit component 39. The first end of the second terminal 33 is connected to the second detection electrode 35. On the other hand, the second end of the second terminal 33 is connected to the circuit component 39.

  Therefore, the circuit component 39 is connected to the first detection electrode 34 and the second detection electrode 35 via the first terminal 32 and the second terminal 33 as shown in FIGS. The circuit component 39 is connected to the output terminal 390.

  Next, as shown in FIG. 2, the sensor unit 16 includes the piezoelectric film 31, the adhesive layer 91 and the adhesive layer 92, the first detection electrode 34, the second detection electrode 35, the substrate unit 36, and the substrate unit 37. Prepare.

  As shown in FIG. 2, the first detection electrode 34, the second detection electrode 35, the piezoelectric film 31, the substrate portion 36, and the substrate portion 37 each have a flat main surface and a back main surface that are opposed to each other in the thickness direction. Prepare. In addition, the upper side surface in FIG. 2 is referred to as a front main surface, and the lower side surface is referred to as a back main surface.

  As shown in FIG. 2, the substrate portion 37, the second detection electrode 35, the adhesive layer 91, the piezoelectric film 31, the adhesive layer 92, the first detection electrode 34, and the substrate portion 36 are arranged in this order from the front main surface side. It is laminated over the back main surface side.

  Specifically, the second detection electrode 35 is laminated on the front main surface of the piezoelectric film 31 via the adhesive layer 91, and the substrate portion 37 is further laminated on the front main surface of the second detection electrode 35. Further, the first detection electrode 34 is laminated on the back main surface of the piezoelectric film 31 via the adhesive layer 92, and the substrate portion 36 is further laminated on the back main surface of the first detection electrode 34.

  The second detection electrode 35, the first detection electrode 34, the piezoelectric film 31, the substrate portion 37, and the substrate portion 36 have a substantially rectangular outer shape in plan view. The outer shapes of the substrate portion 37 and the substrate portion 36 are slightly larger than the outer shape of the piezoelectric film 31.

A second detection electrode 35 is formed on the back main surface of the substrate portion 37, and a first detection electrode 34 is formed on the front main surface of the substrate portion 36. As shown in FIG. 2, the piezoelectric film 31 is stuck to the front main surface of the first detection electrode 34 with an adhesive layer 92. The piezoelectric film 31 is attached to the back main surface of the second detection electrode 35 with an adhesive layer 91.
The pressure-sensitive adhesive layer 91 and the pressure-sensitive adhesive layer 92 are made of, for example, an acrylic pressure-sensitive adhesive.

  Next, the configuration of the piezoelectric film 31 will be described in detail.

As shown in FIG. 3, the piezoelectric film 31 is molecularly oriented in a direction 19 that forms about 45 ° with respect to the long side and the short side. The piezoelectric film 31 is a film mainly composed of L-type polylactic acid (PLLA). PLLA is a chiral polymer whose main chain has a helical structure, and has a property of expressing piezoelectricity by being oriented in a predetermined axial direction. This piezoelectricity is represented by a piezoelectric tensor component d ₁₄ with the film thickness direction as the first axis and the PLLA molecule orientation direction as the third axis.

In the piezoelectric film 31 having the piezoelectric tensor component d ₁₄ is a direction intersecting the long sides and short sides in the front main surface and rear main surface, specifically about 45 ° direction with respect to the long sides and short sides, By setting the direction in which the PLLA molecules are oriented, the pressing force from the thickness direction can be detected.

  However, the angle of the direction 19 in the piezoelectric film 31 is not limited to an accurate 45 ° with respect to the long side and the short side, and can be any angle close to 45 °. As the angle in the direction 19 is closer to 45 ° with respect to the long side and the short side, the pressing force from the thickness direction can be detected more efficiently.

  Accordingly, the term “approximately 45 °” as used in the present invention refers to an angle within a predetermined range centered on 45 °, for example, about 45 ° ± 10 °. These specific angles may be appropriately determined according to the overall design based on the use of the displacement sensor, the characteristics of each part, and the like.

  The piezoelectric film 31 is not limited to a film mainly composed of PLLA, and may be a film mainly composed of D-type polylactic acid (PDLA) or polyvinylidene fluoride (PVDF). However, the piezoelectricity of the piezoelectric film 31 mainly composed of a chiral polymer such as PLLA or PDLA is not expressed by the polarization of ions like ferroelectrics such as PVDF and PZT, and is characteristic of molecules. It is derived from the spiral structure.

  Therefore, the chiral polymer does not need to exhibit piezoelectricity by poling treatment like other polymers such as PVDF and piezoelectric ceramics using a piezoelectric crystal thin film, and PVDF or the like has a piezoelectric constant over time. Although fluctuations are observed and in some cases the piezoelectric constant may be significantly reduced, the piezoelectric constant of the chiral polymer is very stable over time.

  Furthermore, the chiral polymer does not generate pyroelectricity that occurs in other ferroelectric piezoelectric materials. Therefore, the piezoelectric film 31 mainly composed of a chiral polymer can obtain a detection voltage corresponding only to the pressing force without depending on the temperature at the detection position at the time of pressing detection.

  In addition, since the chiral polymer is a polymer and has flexibility, it is not damaged by a large displacement unlike piezoelectric ceramics. Therefore, the piezoelectric film 31 mainly composed of a chiral polymer is not damaged even if the displacement amount is large, and the displacement amount can be reliably detected.

  After the piezoelectric sensor 100 is manufactured, it is necessary to inspect whether an appropriate voltage is output (ie, a good product or a defective product) when it is pressed, for example, before being mounted on an electronic device. Here, when an appropriate voltage is output when the piezoelectric sensor 100 is pressed, the piezoelectric sensor 100 can be determined as a non-defective product.

Hereinafter, an inspection method of the piezoelectric sensor 100 will be described. The inspection method of the piezoelectric sensor 100 uses a sensor inspection device 15.
FIG. 4 is a plan view of the sensor inspection device 15 used in the first inspection method of the embodiment of the present invention. 5 is a cross-sectional view taken along line BB shown in FIG.

  First, as shown in FIGS. 4 and 5, the sensor unit 16 of the piezoelectric sensor 100 is set in the sensor inspection device 15. Specifically, the sensor unit 16 of the piezoelectric sensor 100 is placed on the suction plate 150, and the output terminal 390 of the piezoelectric sensor 100 is connected to the measurement unit 158 of the sensor inspection device 15.

As illustrated in FIGS. 4 and 5, the sensor inspection device 15 includes a piezo actuator 120, a suction plate 150, a housing 152, a suction pump 159, and a measurement unit 158.
The suction plate 150 corresponds to an example of the suction member of the present invention. The piezo actuator 120 corresponds to an example of the bending mechanism of the present invention.

  The casing 152 has a rectangular parallelepiped shape with the top surface opened. As shown in FIGS. 4 and 5, the suction plate 150 is placed on the housing 152 so as to close the opening surface of the housing 152. The material of the housing 152 is, for example, aluminum.

  The suction plate 150 has a plurality of holes 151. The material of the suction plate 150 is, for example, SUS (stainless steel). The suction plate 150 forms a vacuum chamber 155 together with the housing 152. A vent hole (not shown) is provided on the side surface of the housing 152. The vacuum chamber 155 is connected to the suction hole of the suction pump 159 through a vent hole.

  Next, the sensor inspection device 15 drives the suction pump 159 in a state where the sensor unit 16 of the piezoelectric sensor 100 is placed so as to close the plurality of holes 151. As a result, the vacuum chamber 155 is depressurized by the suction pump 159. Thereby, the sensor unit 16 is sucked into the plurality of holes 151 and is sucked into the suction plate 150. At this time, the sensor unit 16 has a flat shape because it is adsorbed by the adsorption plate 150 even in the thickness direction.

  FIG. 6 is a cross-sectional view taken along line BB showing a state where a portion of the suction plate 150 shown in FIG. 4 is being pressed. In addition, in FIG. 6, in order to demonstrate a mode that the sensor part 16 and the adsorption | suction board 150 bend, these bending is emphasized and shown.

  Next, as shown in FIG. 6, the sensor inspection device 15 vibrates the second area other than the first area where the sensor unit 16 is adsorbed on the surface of the adsorption plate 150 with the tip 121 of the piezo actuator 120. Let Thereby, the suction plate 150 vibrates in the thickness direction.

  Here, when the suction plate 150 is bent in the thickness direction, the sensor unit 16 is also bent in the thickness direction. That is, between the first detection electrode 34 and the second detection electrode 35, the detection voltage having a voltage value corresponding to the magnitude of the pressing force (the amount of expansion of the piezoelectric film 31) is a voltage polarity corresponding to the direction of the pressing force. It occurs in. This detection voltage is input to the circuit component 39 through the first terminal 32 and the second terminal 33 as a press detection signal (see FIG. 1). The measuring unit 158 of the sensor inspection device 15 measures the detection voltage from the output terminal 390 of the circuit component 39.

Therefore, the first inspection method can measure the output of the sensor unit 16 without pressing the sensor unit 16.
Therefore, the first inspection method can inspect the output without damaging the piezoelectric sensor 100.

  Moreover, since the sensor part 16 is adsorb | sucked by the adsorption | suction board 150 even if it follows the thickness direction, it becomes a flat shape. Therefore, the first inspection method can measure the output of the sensor unit 16 regardless of the individual difference of the sensor unit 16.

Hereinafter, a second inspection method according to another embodiment of the present invention will be described.
FIG. 7 is a plan view of an inspection apparatus 25 used in the second inspection method according to another embodiment of the present invention. The second inspection method is different from the first inspection method in that the outputs of the plurality of piezoelectric sensors 100 are simultaneously inspected.

  In the second inspection method, the sensor inspection device 25 including the suction plate 250 is used. The number of holes 151 in the suction plate 250 is larger than the number of holes 151 in the suction plate 150. In addition, the sensor inspection device 25 includes two measuring units 158 and 258. Other configurations are the same.

  In this configuration, first, a plurality of piezoelectric sensors 100 are set in the sensor inspection device 25. Specifically, each sensor unit 16 is placed on the suction plate 250, and each output terminal 390 is connected to the measurement units 158 and 258.

  Next, the sensor inspection device 25 drives the suction pump 159 in a state where each sensor unit 16 is placed so as to close the plurality of holes 151. Accordingly, each sensor unit 16 is sucked into the plurality of holes 151 and sucked to the suction plate 250. Then, the sensor inspection device 25 vibrates the fourth region of the surface of the suction plate 250 other than the third region where the plurality of sensor units 16 are attracted by the tip portion 121 of the piezo actuator 120.

  Thereby, the suction plate 250 is bent and each sensor unit 16 is also bent. Then, the measuring units 158 and 258 measure the output of each sensor unit 16. Therefore, the second inspection method can inspect the outputs of the plurality of piezoelectric sensors 100 simultaneously. The second inspection method also has the same effect as the first inspection method.

  In the above-described embodiment, the planar shape of the piezoelectric film 31 is a rectangular shape, but is not limited thereto. In implementation, the planar shape of the piezoelectric film may be other planar shapes such as a square shape, a circular shape, a trapezoidal shape, a parallelogram shape, a polygonal shape of quadrilateral or more, an elliptical shape, an oval shape, or the like.

  Moreover, in the said embodiment, although the material of the adsorption | suction plates 150 and 250 is SUS (stainless steel), it is not restricted to this. In implementation, the material of the suction plates 150 and 250 may be, for example, a glass plate.

  In the above embodiment, the piezoelectric sensor 100 is inspected, but the present invention is not limited to this. In implementation, other sensors, such as an acceleration sensor, may be inspected.

  Moreover, in the said embodiment, although the piezo actuator 120 is used, it is not restricted to this. In implementation, an electric actuator driven by a motor may be used. However, the pressing amount of the electric actuator cannot be set more finely than the pressing amount of the piezo actuator 120.

  Conversely, since the piezo actuator 120 is driven by the piezo piezoelectric effect, the pressing amount of the piezo actuator 120 can be set very finely compared to the pressing amount of the electric actuator by changing the voltage applied to the piezo element. it can.

  Finally, the description of each of the embodiments should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

DESCRIPTION OF SYMBOLS 15 ... Sensor inspection apparatus 16 ... Sensor part 25 ... Sensor inspection apparatus 30 ... Flexible printed circuit board 31 ... Piezoelectric film 32 ... 1st terminal 33 ... 2nd terminal 34 ... 1st detection electrode 35 ... 2nd detection electrode 36, 37 ... board | substrate Part 38 ... Component mounting part 39 ... Circuit parts 91 and 92 ... Adhesive layer 100 ... Piezoelectric sensor 120 ... Piezo actuator 121 ... Tip part 150 ... Suction plate 151 ... Hole 152 ... Housing 155 ... Vacuum chamber 158 ... Measuring part 159 ... Suction pump 250 ... suction plate 258 ... measuring unit 390 ... output terminal

Claims (4)

An adsorption process for adsorbing the sensor to the adsorption member;
A bending step of bending the adsorption member;
A measurement step of measuring an output of the sensor that is bent by bending of the adsorption member;
Only including,
The said bending process is a sensor test | inspection method of pressing 2nd area | regions other than the 1st area | region where the said sensor is adsorbed among the surfaces of the said adsorption member . The sensor inspection method according to claim 1.
The sensor is a piezoelectric sensor,
The sensor inspection method according to claim 1 , wherein the measuring step measures a voltage output from the sensor. The sensor inspection method according to claim 1 , wherein the number of sensors is plural. An adsorbing member that adsorbs the sensor;
A bending mechanism for bending the adsorption member;
A measuring unit that measures the output of the sensor that is bent when the suction member is bent ; and
Wherein the deflection mechanism, the suction of the surface of the member, the sensor test apparatus wherein the sensor you press a second region other than the first region being adsorbed.

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