JP2018004341A - Hitting dot testing device, and hitting dot testing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide for use in FPC a hitting dot testing device and a hitting dot testing method that permit evaluation of durability even in bent parts close to parts where loads are directly applied.SOLUTION: A part closer to the tip than a bent part 10a of an FPC 10 is inserted into a gap S and held in a state with a prescribed play permitting moves in a lateral direction (X direction) in the tip side flat part 10c. By moving an indenter 31 of a load applying part 30 up and down, the FPC 10 is pressed at a set implanting distance, and a prescribed load is applied repeatedly. In this way, damages to wiring not only in the base end side flat part 10b of the FPC 10 due to loads applied in one direction (the Z axis side direction) damages to wiring but also in the bent part 10a where stresses invited by deformation of the FPC 10 is apt to concentrate can be checked.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a dot test apparatus and a dot test method, and more particularly to a dot test apparatus and a dot test method for evaluating the dot durability of a flexible printed wiring board.

  In recent years, with the progress of downsizing, weight reduction, and space saving of electronic devices, flexible printed wiring boards (FPCs) that are thin, light, flexible, and have excellent durability even after repeated bending are used. The demand for Circuits) is increasing. FPC can be mounted three-dimensionally and densely in a limited space. For example, it can be used for wiring of movable parts of electronic devices such as HDDs, DVDs, mobile phones, smartphones, cables, connectors, etc. Applications are expanding.

  Since a pressing force is repeatedly applied to a movable part such as a switch of an electronic device, there is a concern about the occurrence of problems such as poor connection due to wiring breakage in the FPC used in the movable part. Therefore, in order to improve the reliability of electronic equipment, it is required to accurately evaluate the hit point durability of FPC.

  Patent Document 1 proposes a testing device devised so as to change the keying position in the horizontal direction by imitating the displacement of the pressing position in the actual machine in the keying durability test for the transparent conductive film of the resistive touch panel. Yes. Patent Document 2 proposes a device that detects a stroke and a pressing force when a side key provided on a side portion of a mobile phone or the like is clicked. As described above, a technique for performing a keystroke test on parts such as a touch panel and a key used in an electronic device has been proposed, but a method capable of directly evaluating the FPC hitting durability has not been reported. For this reason, the present inventors have proposed an invention of a dot test apparatus for evaluating the dot durability of an FPC (Japanese Patent Application No. 2015-189225). This dot test apparatus evaluates the degree of damage such as breakage of wiring by hitting an indenter repeatedly at a right angle to an arbitrary part of a flat surface of a tape-like FPC.

JP 2009-42817 A JP 2014-186802 A

  In an electronic device such as a smartphone, in order to effectively use the limited space in the housing, wiring from the back wall of the housing to the inner wall of the side is required for wiring to the side keys provided on the side of the housing. In some cases, the FPC may be arranged in a state of being bent at a substantially right angle. In this case, the bent portion is positioned in the vicinity of the pressed portion of the FPC by the side key, and stress is repeatedly applied not only to the portion to which the load is directly applied but also to the bent portion in the vicinity thereof. However, in the hitting point test apparatuses so far, the durability other than the portion to which the direct load is applied is not measured, and the degree of wiring damage at the bent portion cannot be evaluated.

  Accordingly, an object of the present invention is to provide a dot test apparatus and a dot test method capable of evaluating the durability of a bent part close to a part to which a direct load is applied in FPC.

  The hitting test apparatus according to the present invention includes a sample fixing portion that fixes a flexible printed wiring board having a tape shape, and an indenter that reciprocates with a certain amount of movement with respect to the flexible printed wiring board fixed to the sample fixing portion. A load application unit that applies a repeated load. The hitting test apparatus of the present invention evaluates the durability of two or more portions where deformation occurs when a load is applied by the indenter in the flexible printed wiring board.

  In the dot test apparatus according to the present invention, the flexible printed wiring board has a bent portion bent at an angle of 100 degrees or less, and a load is applied to an adjacent portion near the bent portion by the load applying unit. Thus, durability at both the bent portion and the adjacent portion may be evaluated.

  In the dot test apparatus according to the present invention, the flexible printed wiring board is opposite to the first plane portion adjacent to the bent portion and the first plane portion with the bent portion interposed therebetween as the adjacent portion. And a second plane part adjacent to the bent portion, and the load application part may apply a load to the first plane part. In this case, the sample fixing part may have a base that supports the flexible printed wiring board, and the base fixes the first flat part and the second flat part. You may hold | maintain in the state which permitted the movement.

  The hitting test apparatus of the present invention may include a replaceable receiving member mounted on the base, and the first flat surface portion and the receiving member may overlap each other in the load application direction. Good.

  In the dot test apparatus according to the present invention, the receiving member may be made of an elastically deformable material.

  The dot test apparatus of the present invention may further include a measuring unit that is connected to the wiring of the flexible printed wiring board and detects an electrical parameter thereof. In this case, the measurement unit may separately detect the electrical parameter for the wiring provided so as to pass through the bent portion and the wiring provided for the first plane portion. . The electrical parameter may be a resistance value, a current value, or a voltage value.

  In the dot test apparatus according to the present invention, the sample fixing unit may further include a horizontal driving unit that moves the base in a horizontal direction.

  In the dot test apparatus according to the present invention, the amount of movement of the indenter is such that the flexible printed wiring is further at a predetermined distance from a position where a load is applied to the flexible printed wiring board fixed to the sample fixing portion. You may set so that a board may be pushed in.

  The dot test apparatus of the present invention may be a double-sided flexible printed wiring board in which the flexible printed wiring board has wiring on both sides, and the measuring units are respectively connected to the wirings on both sides of the double-sided flexible printed wiring board. The electrical parameters may be detected individually.

The dot test method of the present invention is a method for evaluating the dot durability of a flexible printed wiring board. The dot test method of the present invention includes the following steps a to c:
Step a) A step of fixing a flexible printed wiring board having a tape shape,
Step b) A step of repeatedly applying a load by an indenter that reciprocates with a fixed amount of movement with respect to the fixed flexible printed wiring board,
Step c) In the flexible printed wiring board, a step of evaluating durability of two or more portions where deformation occurs when a load is applied by the indenter,
It is characterized by including.

  In the dot test method of the present invention, the flexible printed wiring board may have a bent portion bent at an angle of 100 degrees or less, and in step b, a load is applied to an adjacent portion in the vicinity of the bent portion. In addition, in the step c, durability in both the bent portion and the adjacent portion may be evaluated.

  In the dot test method according to the present invention, the flexible printed wiring board is opposite to the first plane portion adjacent to the bent portion and the first plane portion with the bent portion interposed therebetween as the adjacent portion. And a second plane portion adjacent to the bent portion. In the step b, a load may be applied to the first plane portion.

  In the dot test method of the present invention, in the step a, the first flat surface portion may be fixed and held in a state in which movement of the second flat surface portion is allowed.

  The hit point test apparatus and the hit point test method of the present invention can evaluate the durability of two or more parts that are deformed when a load is applied in an FPC. The hit point durability of FPC can be evaluated under the above conditions. Therefore, by evaluating the dot durability of the FPC using the dot test apparatus and the dot test method of the present invention, the reliability of the FPC is improved, and further, the operational reliability of the electronic device using the FPC is improved. be able to.

It is a schematic block diagram of the dot test apparatus of one embodiment of this invention. It is a disassembled perspective view which shows one structural example of a sample fixing | fixed part. It is sectional drawing which shows the state which fixed FPC to the sample fixing | fixed part. It is a principal part enlarged view of FIG. It is a schematic diagram explaining the state where the indenter has reached the zero point position. It is a schematic diagram explaining the additional pushing amount from a zero point position. It is drawing explaining the deformation | transformation behavior of a flexible printed wiring board. It is a schematic diagram which shows the deformation | transformation state following FIG.

  Hereinafter, a flexible printed wiring board (FPC) dot test apparatus (hereinafter, simply referred to as “dot test apparatus”) according to an embodiment of the present invention will be described with reference to the drawings as appropriate. FIG. 1 is a schematic configuration diagram of a dot test apparatus 100 according to the present embodiment. The spot test apparatus 100 according to the present embodiment is connected to a sample fixing unit 20 that fixes the FPC 10, a load application unit 30 that repeatedly applies a load toward the FPC 10 fixed to the sample fixing unit 20, and wiring of the FPC 10. And a control unit 50 that controls each component of the hit point test apparatus 100. FIG. 2 is an exploded perspective view showing a configuration example of the sample fixing unit 20. FIG. 3 is a cross-sectional view showing a state in which the FPC 10 is fixed to the sample fixing portion 20. FIG. 4 is an enlarged cross-sectional view showing a main part of FIG.

<Sample>
In the dot test apparatus 100 of the present embodiment, the sample to be tested is the FPC 10. The FPC 10 has a known configuration, and although not described in detail, the FPC 10 is a flexible circuit board having a resin layer and wiring formed on one side or both sides of the resin layer. Further, the FPC 10 has a bent portion 10a. The FPC 10 has a bent portion 10a as a boundary, and a proximal plane portion (first planar portion) 10b adjacent to the proximal end side and a distal end side planar portion (second planar portion) adjacent to the distal end side thereof. 10c. In the present embodiment, the FPC 10 to be tested is one that is bent at an angle of around 90 degrees near the tip, preferably at an angle of less than 90 degrees. That is, as the FPC 10, the angle formed by the proximal end side plane portion 10b and the distal end side plane portion 10c of the bent portion 10a is, for example, in the range of 80 to 100 degrees, preferably in the range of 85 degrees to 95 degrees, and more preferably. Is bent within a range of 85 to 90 degrees. Note that the corner of the bent portion 10a may be curved with a predetermined radius of curvature. In addition, the expressions “proximal end side” and “distal end side” are used for convenience in the FPC 10 used for the test with reference to the bent portion 10a. It does not mean that it is the tip side.

  Although illustration is omitted, the base-side plane portion 10b and the tip-side plane portion 10c can be provided with wirings that are electrically disconnected from each other independently. For example, a wiring that is electrically disconnected from the wiring of the base end side plane portion 10b and passes through the bent portion 10a can be provided in the distal end side plane portion 10c.

<Sample fixing part>
In the present embodiment, the sample fixing unit 20 fixes the base 21, the FPC receiving member 22 that is replaceably attached to the base 21, and the base end side flat part 10 b of the FPC 10 so as to be sandwiched from above and below. A plurality of resin sheets (lower resin sheet 23 and upper resin sheet 24), a sheet fixing plate 25 for pressing these resin sheets, and the lateral movement (X direction) with respect to the front end side of the bent FPC 10 A presser block 26 to be restricted.

(Base)
The base 21 is a metal member such as aluminum, for example, and a recess 21a for accommodating the FPC receiving member 22 and a recess 21b for positioning and fixing the sheet fixing plate 25, the FPC 10 and the like are formed on the upper surface thereof. Has been. An opening 21c for inserting the presser block 26 is formed on one side of the base 21. At the upper end of the wall 21d facing the opening 21c of the base 21, a chamfered corner is formed to form an inclined surface 21e.

(FPC receiving member)
The FPC receiving member 22 is disposed between the base 21 and the FPC 10. The FPC receiving member 22 is fitted into a recess 21 a formed in the base 21, and in a state where the FPC 10 is fixed to the base 21, the base end side plane portion b is overlapped with the base end side plane portion 10 b. Is positioned below. The FPC receiving member 22 is preferably selected from materials that simulate the hardness of a rigid substrate, a lithium ion battery, or the like that is actually mounted on an electronic device. For example, a metal block or spring made of a material such as aluminum, for example, A resin block made of a material such as urethane can be used. Here, a block means a board, a rectangular parallelepiped, a columnar body, etc., for example. When the FPC receiving member 22 is an elastic body such as a spring or a resin block, for example, by utilizing the elastic deformation, the movement of the switch part of the actual electronic device is made to the flexible FPC 10. A simulated bending stress can be applied.

(Resin sheet)
The sample fixing unit 20 may include a plurality of resin sheets in order to stably fix the FPC 10 and to approximate an environment such as a switch unit of an actual electronic device. The plurality of resin sheets are stacked above or below the base-end plane portion 10b of the FPC 10 and function as a cushioning material that imparts appropriate cushioning properties and softens the load applied by the indenter 31.

  In the example shown in FIG. 2, a lower resin sheet 23 and an upper resin sheet 24 are sequentially provided from the base 21 side. The lower resin sheet 23 is disposed on the base 21 side below the FPC 10, for example, between the FPC 10 and the FPC receiving member 22. The upper resin sheet 24 is disposed on the indenter 31 side above the FPC 10, for example, between the FPC 10 and the sheet fixing plate 25. At the time of testing, the lower resin sheet 23 and the upper resin sheet 24 are stacked on the FPC 10 as shown in FIG. 3, for example, and are arranged so as to sandwich the base end side plane portion 10b of the FPC 10 from above and below. Thereby, it functions as a cushioning material against the load by the indenter 31.

  The lower resin sheet 23 and the upper resin sheet 24 are preferably made of, for example, a material such as polytetrafluoroethylene (PTFE) resin, silicone resin, or urethane resin in order to approximate the environment such as a switch part of an actual electronic device. . In addition, the thickness of these resin sheets is preferably in the range of 0.1 mm to 1.0 mm, for example, in order to have a sufficient buffering action against the load by the indenter 31. In addition, the lower resin sheet 23 and the upper resin sheet 24 are arbitrary structures, and do not necessarily need to arrange | position. Further, the lower resin sheet 23 and the upper resin sheet 24 are not limited to one sheet, and two or more sheets may be used.

(Seat fixing plate)
The sheet fixing plate 25 is a metal flat plate made of, for example, SUS. Further, the outer edge portion of the sheet fixing plate 25 has a rectangular shape as a whole corresponding to the contour of the recess 21 b of the base 21. The sheet fixing plate 25 can be positioned by fitting into the recess 21b.

  The sheet fixing plate 25 presses and fixes the laminated lower resin sheet 23, FPC 10, and upper resin sheet 24 from above. With the sheet fixing plate 25, the FPC 10 as the sample can be securely fixed so as not to be displaced during the test.

(Presser block)
The presser block 26 has a convex portion 26 a that is inserted into an opening 21 c formed in the base 21. As shown in FIGS. 2 to 4, the presser block 26 can be fitted into the opening 21 c by sliding in the lateral direction (X direction). An inclined surface 26b is formed by chamfering a corner at the top of the tip of the convex portion 26a.

  In the present embodiment, a gap S is formed with a predetermined width L between the tip of the convex portion 26a and the wall 21d of the base 21 with the convex portion 26a fitted in the opening 21c. The The width L of the gap S can be, for example, in the range of 0.5 to 2 mm, preferably in the range of 1 to 2 mm. In the gap S, the distal end side (the portion including the distal end side flat portion 10c) is inserted from the bent portion 10a of the FPC 10. In this state, the tip side flat surface portion 10c is held in a state having a predetermined play so that the movement in the lateral direction (X direction) intersecting the flat surface is allowed. The distal end portion of the FPC 10 (the most distal end of the distal end side flat portion 10c) is fixed to the wall 21d of the base 21 by an arbitrary fixing means such as an adhesive tape, screwing, fitting into a narrow groove, or a clamping mechanism. It is preferable to keep. Further, in order to prevent the FPC 10 held with a predetermined degree of freedom by the gap S from being damaged by a sharp angle, the inclined surface 26b at the upper end of the convex portion 26a and the wall 21d of the base 21 are provided. An inclined surface 21e is formed.

(Horizontal drive unit)
The sample fixing unit 20 further includes a horizontal driving unit 29 that moves the base 21 in the horizontal direction (XY direction). Although not shown, the horizontal drive unit 29 is, for example, an X-axis actuator that moves the base 21 along the X-axis guide, a Y-axis actuator that moves the base 21 along the Y-axis guide, An encoder or the like provided on each of the Y axes is provided. As the X-axis actuator and Y-axis actuator, for example, a linear motor, an air cylinder, a ball screw, or the like can be used. The horizontal drive unit 29 can move the base 21 in the XY direction within a range of, for example, ± 50 mm. The horizontal drive unit 29 can apply a load to a position where the center of the indenter 31 is off the center of the FPC receiving member 22. Therefore, it is possible to perform a test simulating the eccentricity of the pressing force when operating the switch unit of an actual electronic device.

<Load application part>
The load application unit 30 includes an indenter 31 for applying a load to the FPC 10, a Z-axis drive unit 32 that linearly reciprocates the indenter 31 in the Z-axis direction (vertical direction) with a constant movement amount (stroke), and an indenter 31 and the shaft part 33 which connects the Z-axis drive part 32 are provided.

  The indenter 31 has a cylindrical shape as a whole, and a tip portion of the indenter 31 has a rounded conical shape. Although not shown, the indenter 31 is configured by a metal core made of, for example, SUS or the like and a resin layer that covers the metal core. As resin which comprises a resin layer, a urethane resin, a polyacetal resin, a silicone resin etc. can be used, for example. The hardness of the tip portion of the indenter 31 is preferably in the range of Shore hardness A50 to Rockwell hardness M90, for example, from the viewpoint of the usage pattern of the electronic device on which the FPC 10 is mounted. Further, the radius of curvature of the tip portion of the indenter 31 is preferably in the range of 0.8 mm to 12 mm, for example, from the viewpoint of the usage pattern of the electronic device on which the FPC 10 is mounted.

(Z-axis drive unit)
Although not shown in the figure, the Z-axis drive unit 32 includes an actuator such as an air cylinder, a load cell for detecting a load, and the like.

  The load application unit 30 is configured so that a preset load can be applied to the proximal-end plane portion 10 b of the FPC 10 fixed to the sample fixing unit 20 by the indenter 31.

Further, the load application unit 30 is further at a predetermined distance from the position (zero point position) where the application of the load by the indenter 31 is started with respect to the base end side plane portion 10b of the FPC 10 fixed to the sample fixing unit 20. The amount of movement of the indenter 31 can be set so that the proximal side flat portion 10b of the FPC 10 can be pushed. Figure 5 shows a state in which the indenter 31 has reached the zero point position P ₀ schematically. FIG. 6 schematically shows a state where the indenter 31 is further pushed to the position P ₁ from the zero point position P ₀ shown in FIG. In FIGS. 5 and 6, for convenience of explanation, the thicknesses of the FPC 10, the lower resin sheet 23, and the upper resin sheet 24 are exaggerated. Here, the amount of pushing by the indenter 31 (distance from the zero point position _{P 0} to the position _{P 1; P} 0 ~P ₁₎ can be arbitrarily set within a range of, for example, 0.1Mm～1.9Mm. As described above, since the durability test is performed using the elastic deformation of the FPC receiving member 22 in the hit point test apparatus 100, the push-in amounts P _{0 to} P ₁ can be set variably, thereby allowing flexibility. It is possible to evaluate the hit point durability specialized for the FPC 10 having

<Measurement unit>
During the test, the measuring unit 40 continuously or intermittently passes a current through the FPC 10 fixed to the sample fixing unit 20 to detect an electrical parameter. Examples of electrical characteristics detected by the measurement unit 40 include a resistance value, a current value, and a voltage value. Among these, it is preferable to detect a resistance value that can easily detect a change due to disconnection of the wiring.

  The measuring unit 40 is connected to the wiring (not shown) of the FPC 10 by a plurality of lead wires 41. For example, one wiring can be formed over the entire FPC 10, and the two lead wires 41 can be connected so as to sandwich both the base end side plane portion 10b and the tip end side plane portion 10c. In this way, electrical parameters can be detected for the entire FPC 10. Further, for example, two lead wires 41 are connected to a wiring formed only on the base end side plane portion 10b, and the other two lead wires 41 pass through the bent portion 10a and the tip end side plane portion 10c. It can be connected to the wiring formed in the above. In this way, it is possible to individually detect the electrical parameters for the proximal-side plane portion 10b and the distal-side plane portion 10c with the bent portion 10a interposed therebetween. In this case, it can be inferred that the abnormality in the electrical parameters of the tip side flat surface portion 10c is caused by damage to the wiring in the bent portion 10a. In FIG. 1, only two lead wires 41 are representatively shown.

  When the FPC 10 is a double-sided FPC having wirings on both sides, the lead wires 41 can be individually connected to the wirings formed on both sides. Thereby, the measurement part 40 can detect the electrical parameter of wiring of both surfaces separately.

<Control unit>
The control unit 50 controls each component of the hit point test apparatus 100. The control unit 50 is typically a computer, and although not shown, a main control unit having a CPU (Central Processing Unit) and a RAM (Random Access Memory), an input device such as a keyboard and a mouse, a printer, and the like Output device, a display device such as a display, and a storage device such as a hard disk.

  The control unit 50 is configured so that each component (for example, the horizontal drive unit 29, the load application unit 30, and the measurement unit) of the spot test apparatus 100 is executed so that the spot test for the FPC 10 is performed in the spot test apparatus 100 of the present embodiment. 40 etc.). These are realized by the CPU of the control unit 50 executing the software (program) stored in the storage device using the RAM as a work area.

  In the hitting test apparatus 100 having the above configuration, the hitting test on the FPC 10 can be performed by appropriately setting the number of times the indenter 31 is driven, the driving load, the driving speed, the amount of movement of the indenter 31, and the like.

  For example, when measuring the resistance value, in the FPC 10, a current of DC 1.0 V / 10 mA or less is applied to the wiring of the base end side plane portion 10b and the wiring of the tip end side plane portion 10c, respectively. The ratio of the measured value to the initial resistance value is calculated. The control unit 50 determines the durability of the FPC 10 by comparing the ratio of the measurement values obtained by the measurement unit 40 with a predetermined threshold value, and displays the result on a display, for example. Here, an abnormality is detected in the measured value of the distal-side flat surface portion 10c by forming the wiring of the distal-side flat surface portion 10c independently through the proximal-side flat surface portion 10b and the bent portion 10a. In such a case, it can be inferred that this is caused by damage to the wiring in the bent portion 10a.

<Action>
With reference to FIG. 7 and FIG. 8, the operation of the hit point test apparatus 100 of the present embodiment will be described. FIG. 7 is a side view of the FPC 10 having the bent portion 10a, and FIG. 8 shows a state in which a load is applied to the proximal side flat portion 10b from the state of FIG. As indicated by white arrows in FIG. 8, the load applied by the load applying unit 30 is applied substantially at a right angle to the surface of the base end side plane portion 10 b of the FPC 10. As described above, the RBI testing apparatus 100, by selecting the material of the FPC receiving member 22, than the zero point position P ₀ the application of the load by the indenter 31 is started, so it is possible to further push the indenter 31 It is configured. Therefore, the base side flat surface portion 10b in the FPC 10 is distorted in the same direction as the load application direction, and is deformed into a downwardly convex arch shape on the paper surface of FIG. Further, the clearance S between the convex portion 26a of the presser block 26 and the wall 21d of the base 21 allows deformation of the distal side flat portion 10c. Therefore, with the deformation of the base end side plane portion 10b, the tip end side plane portion 10c close to the tip end portion of the FPC 10 is pulled rightward in the plane of FIG. 8, and as a result, is deformed into a convex arch shape on the left side. .

  In the spot test device 100, by repeatedly applying a load by the indenter 31, the state of FIG. 7 and the state of FIG. 8 are alternately repeated. A large stress is applied to the bent portion 10a bent at an angle close to a right angle every time the base-side plane portion 10b and the tip-side plane portion 10c on both sides are deformed and returned, and the wiring breaks or the like. Damage is likely to occur. That is, in the FPC 10 having the bent portion 10a, there are at least two or more sites where strain is accumulated due to deformation caused by application of a load. This is considered to be the same for the FPC 10 mounted in a state where the bent portion 10a is provided on the inner side of a side key or the like in an actual electronic device, and imitates the state. That is, in the spot test apparatus 100 according to the present embodiment, not only is the wiring damaged due to a load in one direction (Z-axis direction) applied to the base-end plane portion 10b of the FPC 10, but also due to deformation of the FPC 10. It is configured to be able to inspect wiring damage at the bent portion 10a where stress tends to concentrate.

<Dot test method>
Next, an example of the procedure of the dot test method of the present embodiment performed in the dot test apparatus 100 will be described. Here, a case where a resistance value is measured as an electrical parameter is taken as an example.

The dot test method of the present embodiment can include the following steps (a) to (c).
(a) A step of fixing the FPC 10 having a tape shape.
(b) A step of repeatedly applying a load to the fixed FPC 10 by the indenter 31 that reciprocates with a constant movement amount.
(c) In the FPC 10, a step of evaluating the durability of two or more portions where deformation occurs when a load is applied by the indenter 31.

Step a:
In this step, the FPC 10 having the bent portion 10 a is set on the sample fixing portion 20. At this time, the holding block 26 inserts the distal end side (the portion including the distal end side flat portion 10c) of the FPC 10 into the gap S with respect to the FPC 10 so that the movement of the distal end side flat portion 10c is allowed. Hold it with the. Here, it is preferable to fix the front-end | tip part (front-end | tip of the front end side plane part 10c) of FPC10 to the wall 21d of the base 21 with an adhesive tape etc., for example. And the wiring of the single side | surface or both surfaces of FPC10 and the measurement part 40 are connected by the lead wire 41, and an initial stage resistance value is measured. For example, two lead wires 41 are connected to the wiring formed on the base end side plane portion 10b, and the other two lead wires 41 pass through the bent portion 10a and are connected to the tip end side plane portion 10c. By connecting to the formed wiring, it is possible to individually detect the resistance values of the proximal-side plane portion 10b and the distal-side plane portion 10c with the bent portion 10a interposed therebetween.

Step b:
In this step, first, the indenter 31 of the load application unit 30 is lowered to apply a load to the proximal side flat surface part 10b of the FPC 10 to detect the zero point position. Then, if necessary, the driving distance is set so that the base end side plane portion 10b of the FPC 10 is pushed toward the base 21 side at a predetermined distance from the zero point position.

  Next, by moving the indenter 31 up and down, the FPC 10 is pressed at a set driving distance, and a predetermined load is repeatedly applied.

Step c:
In this step, in the FPC 10, durability of two or more portions where deformation occurs when a load is applied by the indenter 31 is evaluated. More specifically, the durability of both the bent portion 10a and the proximal plane portion 10b is a portion where deformation is caused by applying a load to the proximal plane portion 10b adjacent to the bent portion 10a of the FPC 10. To evaluate. The measuring unit 40 measures the resistance value continuously or intermittently, and calculates the ratio (variation ratio) between the measured resistance value and the initial resistance value. Then, the control unit 50 compares the obtained fluctuation ratio of the resistance value with a predetermined threshold value, and determines that a failure such as disconnection has occurred in the FPC 10 when the fluctuation ratio exceeds the threshold value. On the other hand, even if the number of times set in advance is performed, if the variation ratio is equal to or less than the threshold value, it is possible to determine that the hit point durability of the FPC 10 is acceptable. In addition, this process c may be implemented in parallel while implementing the process b, or may be implemented after completing the process b.

  In the evaluation of the hit point durability, the evaluation can be performed based on various information obtained from the detected resistance value. For example, instead of comparing the fluctuation ratio with a threshold value, the resistance value may be directly compared with a threshold value set appropriately in advance, or the rate of change of the resistance value within a predetermined time may be calculated. The evaluation may be performed by monitoring and comparing the rate of change with a threshold value. The same applies to the case where a parameter other than the resistance value is used as the electrical parameter.

  As described above, according to the hit point test apparatus 100 and the hit point test method of the present embodiment, the FPC 10 shows the actual usage state in the electronic device with respect to two or more parts that are deformed when a load is applied. The durability of the FPC 10 can be evaluated under the simulated conditions. Specifically, in the FPC 10 having the bent portion 10a, the durability of the bent portion 10a can be evaluated as well as the proximal-side plane portion 10b to which a load is applied.

  Since the spot test apparatus 100 according to the present embodiment includes the measurement unit 40 that is connected to the wiring of the FPC 10 and detects the electrical parameters, the spot durability of the FPC 10 is improved despite the simple configuration. Can be evaluated reliably.

  In addition, the dot test apparatus 100 according to the present embodiment supports not only a single-sided FPC having wiring on one side but also a double-sided FPC having wiring on both sides, and simultaneously detects electrical parameters of wirings on both sides. it can. Therefore, it is possible to quickly perform a dot test for a double-sided FPC.

  In addition, since the spot test apparatus 100 according to the present embodiment includes the FPC receiving member 22 in the sample fixing unit 20, a predetermined load can be applied by imitating the movement of a switch unit of an actual electronic device. Therefore, the hit point durability of the FPC 10 can be evaluated in a state close to the actual use environment.

  Moreover, the spot test apparatus 100 of this Embodiment can evaluate the spot durability of FPC10 on the conditions approximated to environments, such as a switch part of an actual electronic device, with a some resin sheet.

  Furthermore, since the spot test apparatus 100 according to the present embodiment includes a horizontal drive unit 29 that moves the base 21 in the horizontal direction (XY direction), the center of the indenter 31 deviates from the center of the FPC receiving member 22. A load can be applied to the position, and a test simulating the eccentricity of the pressing force at the time of operation of a switch part of an actual electronic device can be performed.

  As described above, by evaluating the durability of the FPC 10 using the dot test apparatus 100 and the dot test method of the present embodiment, the reliability of the FPC 10 is improved, and further, the operation reliability of the electronic device using the FPC 10 is improved. Can be improved.

  As mentioned above, although embodiment of this invention was described in detail for the purpose of illustration, this invention is not restrict | limited to the said embodiment. For example, in the above embodiment, the wiring damage is inspected by detecting an electrical parameter. However, it is also possible to inspect the wiring damage by other methods such as electron microscope observation. In that case, it can replace with the measurement part 40 which detects an electrical parameter, and can provide another measuring means.

  DESCRIPTION OF SYMBOLS 10 ... Flexible printed wiring board (FPC), 10a ... Bending part, 10b ... Base end side plane part, 10c ... Front end side plane part, 20 ... Sample fixing part, 21 ... Base, 21a, 21b ... Recess, 21c ... Opening Part, 21d ... wall, 21e ... inclined surface, 22 ... FPC receiving member, 23 ... lower resin sheet, 24 ... upper resin sheet, 25 ... sheet fixing plate, 26 ... presser block, 26a ... convex part, 26b ... inclined surface, DESCRIPTION OF SYMBOLS 29 ... Horizontal drive part, 30 ... Load application part, 31 ... Indenter, 32 ... Z-axis drive part, 33 ... Shaft part, 40 ... Measurement part, 41 ... Lead wire, 50 ... Control part, 100 ... Flexible printed wiring board ( FPC) Dot test device, S ... Gap

Claims (16)

A sample fixing part for fixing a flexible printed wiring board in the form of a tape;
A load application unit that repeatedly applies a load by an indenter that reciprocates with a certain amount of movement with respect to the flexible printed wiring board fixed to the sample fixing unit;
With
In the flexible printed wiring board, a dot test apparatus for evaluating durability of two or more portions where deformation occurs when a load is applied by the indenter.   The flexible printed wiring board has a bent portion bent at an angle of 100 degrees or less, and by applying a load to an adjacent portion in the vicinity of the bent portion by the load application unit, the bent portion and the adjacent portion The hitting test apparatus according to claim 1, wherein durability is evaluated at both of the parts. The flexible printed wiring board, as the adjacent portion,
A first plane portion adjacent to the bent portion;
A second plane portion adjacent to the bent portion on the opposite side of the first plane portion with the bent portion interposed therebetween,
The hitting test apparatus according to claim 2, wherein the load application unit applies a load to the first plane portion. The sample fixing part has a base for supporting the flexible printed wiring board,
The hitting point testing device according to claim 3, wherein the base holds the first flat surface portion and holds the second flat surface portion in a state where the second flat surface portion is allowed to move. Comprising a replaceable receiving member mounted on the base;
The hitting test apparatus according to any one of claims 1 to 4, wherein the first flat portion and the receiving member overlap vertically in the load application direction.   The hitting test apparatus according to claim 5, wherein the receiving member is made of an elastically deformable material.   Furthermore, the hit | damage test apparatus of Claim 6 provided with the measurement part connected to the wiring of the said flexible printed wiring board, and detecting the electrical parameter.   The hitting test apparatus according to claim 7, wherein the measurement unit separately detects the electrical parameter for a wiring provided so as to pass through the bent portion and a wiring provided on the first plane portion. .   The dot test apparatus according to claim 7 or 8, wherein the electrical parameter is a resistance value, a current value, or a voltage value.   The hitting test apparatus according to any one of claims 1 to 9, wherein the sample fixing unit further includes a horizontal drive unit that moves the base in a horizontal direction.   The amount of movement of the indenter is set so as to push the flexible printed wiring board at a predetermined distance from a position at which application of a load is started to the flexible printed wiring board fixed to the sample fixing portion. The dot test apparatus according to any one of claims 1 to 10. The flexible printed wiring board is a double-sided flexible printed wiring board having wiring on both sides,
12. The dot test apparatus according to claim 1, wherein the measuring unit is connected to the wirings on both sides of the double-sided flexible printed wiring board and individually detects the electrical parameters. . A dot test method for evaluating the dot durability of a flexible printed wiring board, comprising the following steps a to c:
Step a) A step of fixing a flexible printed wiring board having a tape shape,
Step b) A step of repeatedly applying a load by an indenter that reciprocates with a fixed amount of movement with respect to the fixed flexible printed wiring board,
Step c) In the flexible printed wiring board, a step of evaluating durability of two or more portions where deformation occurs when a load is applied by the indenter,
The dot test method characterized by including. The flexible printed wiring board has a bent portion bent at an angle of 100 degrees or less,
The striking test method according to claim 13, wherein a load is applied to an adjacent portion in the vicinity of the bent portion in the step b, and durability in both the bent portion and the adjacent portion is evaluated in the step c. The flexible printed wiring board, as the adjacent portion,
A first plane portion adjacent to the bent portion;
A second flat portion adjacent to the bent portion on the side opposite to the first flat portion across the bent portion;
Having
The striking test method according to claim 14, wherein a load is applied to the first plane portion in the step b. The hitting test method according to claim 15, wherein, in the step a, the first plane portion is fixed and held in a state in which movement of the second plane portion is allowed.

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