Electrical characteristic acquisition device

Abstract

To improve an electrical characteristic acquisition device, for example, to satisfactorily acquire an electrical characteristic of an object.SOLUTION: In the present electrical characteristic acquisition device, the approaching / separating device configured to move the pair of probes toward and away from each other includes the electric motor as the drive source, and the electric motor is controlled based on the object. For example, when the open correction value is acquired by controlling the electric motor, the distance between the pair of probes can be favorably brought close to the length of the object on the electrode side. The open correction value can be satisfactorily acquired, and the electrical characteristics of the object can be satisfactorily acquired. Further, the clamping state of the object by the pair of probes can be controlled to the target clamping state. It becomes possible to favorably clamp the object, and it is possible to prevent breakage of the object, to prevent clamping errors of the object, and so on.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electrical characteristic acquisition device for acquiring electrical characteristics of an object. [Background technology]

[0002] Patent Document 1 describes a jig used in an impedance measuring instrument as an electrical characteristic acquisition device. The impedance measuring instrument measures the impedance as an electrical characteristic of an electronic component as a target, and the jig is used to measure an open correction value. The surface of this jig is made of an insulating material and has a thickness that varies in multiple stages. A portion of the jig whose thickness is the same as the length of the electrode side of the electronic component is held by a pair of probes, and stray admittance is measured as an open correction value. As a result, it is possible to measure stray admittance when the distance between the pair of probes is the same as the length of the electrode side of the component. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-21728 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to improve an electrical characteristic acquisition device, for example, to enable good acquisition of electrical characteristics of an object.

[0005] In the electrical characteristic acquisition device according to the present invention, the approaching / separating device that moves the pair of probes closer to or further away from each other includes an electric motor as a drive source, and the electric motor is controlled based on the object. Therefore, for example, when acquiring an open correction value, the distance between the pair of probes can be controlled to suitably approximate the length of the electrode side of the object by controlling the electric motor. The open correction value can be acquired suitably, and the electrical characteristics of the object can be acquired suitably. Furthermore, the clamping state of the object by the pair of probes can be controlled to a target clamping state. Damage to the object during clamping and incorrect clamping of the object can be suppressed, and the object can be clamped suitably. As a result, the electrical characteristics of the object can be acquired suitably. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a perspective view of a placement machine including an electrical characteristic acquisition device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a perspective view of a main part of the electrical characteristic acquisition device. [Figure 3] 1A and 1B are cross-sectional views of the main part of the electrical characteristic acquisition device, showing (a) a steady state and (b) a state when measuring an open correction value. [Figure 4] FIG. 2 is a partial plan view of the electrical characteristic acquisition device. [Figure 5] FIG. 2 is a conceptual diagram showing a coaxial cable used in the electrical characteristic acquisition device. [Figure 6] FIG. 3 is a cross-sectional view of a uniform potential portion provided in the coaxial cable. [Figure 7] FIG. 2 is an exploded view of the same potential portion. [Figure 8] FIG. 2 is a diagram conceptually showing an electrical characteristic measurement circuit of the electrical characteristic acquisition device. [Figure 9] FIG. 2 is a diagram conceptually showing an equivalent circuit of the electrical characteristic measuring circuit. [Figure 10] FIG. 2 is a diagram conceptually showing a component whose electrical characteristics are acquired by the electrical characteristic acquisition device. [Figure 11] FIG. 2 is a block diagram conceptually illustrating the periphery of a control device of the electrical characteristic acquisition device. [Figure 12]4 is a flowchart showing an electrical characteristic acquisition program stored in a storage unit of the control device. [Figure 13] 10 is a flowchart showing a part (S9) of the electrical characteristic acquisition program. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, a placement machine including an electrical characteristic acquisition device according to one embodiment of the present invention will be described in detail with reference to the drawings. [Example]

[0008] The placement machine shown in FIG. 1 is for placing components on a circuit board, and includes a main body 2, a circuit board conveying and holding device 4, a component supplying device 6, a head moving device 8, and the like. The circuit board transport and holding device 4 transports and holds a circuit board P (hereinafter referred to as board P) in a horizontal position. In FIG. 1, the transport direction of the board P is the x direction, the width direction of the board P is the y direction, and the thickness direction of the board P is the z direction. The y direction and z direction are the front-to-back and up-to-down directions of the mounting machine, respectively. The x direction, y direction, and z direction are perpendicular to each other. The component supply device 6 supplies electronic components (hereinafter referred to as components) s to be mounted on the board P, and includes multiple tape feeders 14, etc. The head moving device 8 holds a mounting head 16 and moves it in the x, y, and z directions. The mounting head 16 has a suction nozzle 18 as a component holder that picks up and holds the components s.

[0009] Reference numeral 20 denotes a camera. The camera 20 captures an image of the component s held by the suction nozzle 18, and based on the image captured by the camera 20, it is determined whether the component s is to be mounted on the circuit board P. Reference numeral 22 denotes a measuring device. The measuring device 22 measures the electrical characteristics of the target component s. The electrical characteristics of the component s include L (inductance), C (capacitance), R (resistance), X (reactance), Z' (impedance), and Y (admittance), and the measuring device 22 measures one or more of these. Hereinafter, the electrical characteristics may be collectively referred to as LCR, or each individual electrical characteristic may be referred to as LCR.

[0010] The measuring device 22 is mounted on the placement machine and is attached to the main body of the circuit board conveying and holding device 4 via a storage box 26. A disposal passage 28 is provided between the storage box 26 and the measuring device 22, and components s whose electrical characteristics have been measured are transported through the disposal passage 28 and placed in the storage box 26. The measuring device 22 is mounted on the storage box 26 so that its height can be adjusted. As shown in FIGS. 2 and 3, a base 30 is engaged with the storage box 26 so that it can be raised and lowered, and a measuring table 29 is detachably held to the base 30 by a fastening portion or the like. The base 30 and measuring table 29 can be raised and lowered as a unit. Furthermore, the measuring table 29 and the base 30 are each provided with through-holes 29a, 30a that can communicate with the disposal passage 28 (see FIGS. 3 and 4).

[0011] As shown in Figures 2 to 4, the measuring device 22 includes the measurement stage 29 and base unit 30, a holder 32 capable of holding a component s, a pair of probes 37 capable of acquiring electrical characteristics, a holder moving device 40 for moving the holder 32, a mover moving device 41 as a moving device for moving the pair of probes 37 toward and away from each other, and a measuring unit 42 (see Figure 4). In this embodiment, the component s has electrodes sp1 and sp2 at both ends as shown in Figures 10(a) and 10(b) and can be held by the pair of probes 37, and can be, for example, a square tip. The square tip component s can be, for example, a rectangular tip as shown in Figure 10(b), and the length d of the side having electrodes sp1 and sp2 at both ends is referred to as the electrode-side length d of the component s.

[0012] The holding table 32 includes a component placement section 44 and a placement section holder 46 that holds the component placement section 44. A V-shaped groove 44c is formed in the component placement section 44, and a component s is placed on the placement section 44. The component placement section 44 abuts against the placement section holder 46 and is fixed by a fastening section. As shown in FIG. 3(a), when the measuring device 22 is in a steady state, the placement section holder 46 abuts against the measurement table 29 via a stopper 90, and the measurement table 29 is fixed to the base section 30. The component placement section 44, placement section holder 46, stopper 90, measurement table 29, base section 30, fastening section, etc. are made of conductive materials. The base section 30 is also grounded. As a result, the component placement section 44 is grounded. This allows static elimination from the component s placed on the component placement section 44.

[0013] The pair of probes 37 includes a stator 34 and a mover 36. The stator 34 and the mover 36 have opposing surfaces 34f and 36f, respectively, that face each other, and the part s is gripped by these pair of opposing surfaces 34f and 36f. The stator 34 is held by a stator holder 55, and the stator holder 55 is fixed to the measurement table 29. The mover 36 is held movably integrally by the mover holder 56, and the mover holder 56 is provided movably relative to the measurement table 29. This allows the mover 36 to move towards and away from the stator 34.

[0014] The opposing surface 36f of the mover 36 has a shape that allows it to enter the V-groove 44c formed in the upper surface of the holder 32, in other words, a generally triangular shape that corresponds to the V-groove 44c. Therefore, the mover 36, together with the stator 34, can grip the component s placed in the V-groove 44c. The mover 36 also includes a front end portion 36a including an opposing surface 36f, and the front end portion 36a protrudes downward from the intermediate portion 36b. The outer surface of the front end portion 36a is close to the inner surface of the V-groove 44c, but the intermediate portion 36b is far away from the inner surface of the V-groove 44c.

[0015] 4 and other figures, a coaxial cable portion 58 is connected to the stator holder 55 via a bracket, and a coaxial cable portion 60 is connected to the mover holder 56 via a bracket. Since the stator holder 55, stator 34, mover holder 56, mover 36, and bracket are all made of conductive materials, the stator 34, mover 36, and coaxial cable portions 58, 60 are electrically connected. Furthermore, the stator 34, mover 36, etc., the coaxial cable portions 58, 60, and measuring unit 42, etc., form an electrical characteristic measuring circuit 61.

[0016] The holder moving device 40 is equipped with an air cylinder 64 as a drive source. The mounting portion holder 46 (holding table 32) is connected to the piston rod of the air cylinder 64. The mounting portion holder 46 is moved by the operation of the air cylinder 64. The air cylinder 64 is operated by the supply and discharge of fluid in the air cylinder 64, and the supply and discharge of fluid is controlled by an electromagnetic valve device 80 (see FIG. 11).

[0017] The mover moving device 41 includes an electric motor 66 as a drive source, and a motion conversion mechanism 68 that converts the rotation of the electric motor 66 into linear motion. An output shaft (not shown) of the motion conversion mechanism 68 is connected to the mover holder 56. As the electric motor 66 rotates, the output shaft is moved linearly, and the mover holder 56 is moved linearly (in the y direction).

[0018] A pair of guide rods 86, 87 extending in the y direction are provided between the holder 32 and the mover holder 56, and a pair of guide rods 88, 89 extending in the y direction are provided between the mover holder 56 and the measurement table 29. These guide rods 86, 87, 88, 89 (see FIG. 2, etc.) allow the holder 32 and the mover 36 to move relative to each other in the y direction with respect to the measurement table 29, and also allow the holder 32 and the mover 36 to move relative to each other in the y direction.

[0019] 3(a) and 3(b), a stopper 92 is provided on the stator side of mover holder 56, and a stopper 90 is provided on the portion of measurement table 29 that holds stator holder 55. Stopper 92 defines the approach limit between mover holder 56 and holder table 32 (mounting section holder 46), and stopper 90 defines the approach limit between stator 34 (measurement table 29) and holder table 32.

[0020] The holder 32 is moved by the holder moving device 40 between a position where it abuts against the stopper 90 and a position where it abuts against the stopper 92. As shown in Fig. 3(a), when the holder 32 is at the position where it abuts against the stopper 90 and the pair of probes 37 are separated (when the mover 36 is separated from the stator 34), at least a part of the holder 32 is located between the pair of probes 37, and the holder 32 is in close proximity to the pair of probes 37. As shown in Fig. 3(b), when the holder 32 is at the position where it abuts against the stopper 92, the holder 32 is not located between the pair of probes 37, and is spaced apart by a set distance a or more from at least one of the pair of probes 37 (the mover 36).

[0021] In the electrical characteristic measuring circuit 61, as shown in FIG. 4, the coaxial cable sections 58 and 60 each include two coaxial cables 58a and 58b, and two coaxial cables 60a and 60b. The coaxial cables 58a, 58b, and 60a, 60b each have the same structure, and as shown in FIG. 5, each includes an inner conductor 140, an insulator (dielectric) 142, an outer conductor 144, and a protective coating 146, all arranged coaxially. The outer conductor 144 is often formed of a braided copper wire, which is made by weaving copper wires into a mesh, and is usually connected to ground. The provision of the outer conductor 144 prevents transmitted signals from leaking to the outside. For this reason, the copper wire of the outer conductor 144 can be referred to as a shield wire. The inner conductor 140, the insulator 142, and the outer conductor 144 are covered with a protective coating 146.

[0022] In this embodiment, the electrical characteristics of the component s are measured by the automatic balancing bridge method, and the coaxial cables 58a, 58b, 60a, 60b are connected by the four-terminal pair measurement method. Note that the method for measuring the electrical characteristics of the component s and the method for connecting the coaxial cable portions 58, 60 are not limited to the automatic balancing bridge method and the four-terminal pair measurement method.

[0023] 7, the inner conductors 140 of the coaxial cables 58a and 58b are each connected to one (identical) measurement probe side connection part 58c, and the measurement probe side connection part 58c is attached to the bracket. The inner conductors 140 of the coaxial cables 60a and 60b are also connected to one measurement probe side connection part 60c, and the measurement probe side connection part 60c is attached to the bracket.

[0024] Detector side connectors 58p, 58q, 60p, 60q, which are the other ends of the coaxial cables 58a, 58b, 60a, 60b, are connected to terminals Hc, Hp, Lc, Lp of the measuring unit 42, respectively, as shown in FIGS.

[0025] As conceptually shown in Fig. 8, an AC power supply is connected to coaxial cable 58a. The output of the AC power supply is supplied to inner conductor 140 of coaxial cable 58a and returned via outer conductor 144. In coaxial cable 58b, the potential difference between inner conductor 140 and outer conductor 144 is detected as a voltage value applied to component s.

[0026] In the coaxial cable 60a, the current flowing between the inner conductor 140 and the outer conductor 144 is acquired as the current value flowing through the component s. Strictly speaking, the potential difference of a resistor with a resistance value Rx (not shown) provided between the inner conductor 140 and the outer conductor 144 is acquired, and the current flowing through the resistor is acquired based on the potential difference and the resistance value Rx. In the coaxial cable 60b, the potential difference between the inner conductor 140 and the outer conductor 144 is detected, and components (such as an oscillator) of the measuring unit 42 (not shown) are controlled so that the detected potential difference becomes zero. As a result, the current flowing through the resistor and the current flowing through the component s become the same, and the current flowing through the resistor acquired at the terminal Lc in this state is taken as the current value flowing through the component s.

[0027] Each of the coaxial cables 58a, 58b, 60a, and 60b is provided with a same-potential portion 150, and the outer conductors 144 of the coaxial cables 58a, 58b, 60a, and 60b are electrically connected to each other at the same-potential portion 150. As shown in FIGS. 7 and 8 , the protective coating 146 is removed from each of the coaxial cables 58a, 58b, 60a, and 60b, and copper foil tape 152 is wrapped around the exposed outer conductor 144, and solder 154 is applied. In other words, the coaxial cables 58a, 58b, 60a, and 60b are located at the vertices of a rectangle, and adjacent cables are connected to each other with solder 154. The portions where the protective coating 146 has been removed are covered with protective tubes 156.

[0028] 8, in the same potential portion 150, the outer conductors 144 of the coaxial cables 58a, 58b, 60a, and 60b can be electrically connected to each other, and the potentials of the outer conductors 144 can be made the same. That is, the outer conductors 144 of the coaxial cables 58a, 58b, 60a, and 60b are made to have the same ground potential.

[0029] When the coaxial cables 58a, 58b, 60a, 60b are connected using the four-terminal pair measurement method in this manner, the current flowing through the component s and the voltage applied to the component s are measured using separate circuits. Furthermore, because the currents flowing through the inner conductor 140 and the outer conductor 144 are opposite in direction, the generation of magnetic flux in each of the inner conductor 140 and the outer conductor 144 can be suppressed. As a result, the current and voltage flowing through the component s can be measured with high accuracy. Furthermore, by providing the same potential unit 150, the outer conductors 144 of the multiple coaxial cables 58, 60 are set to the same ground potential, which reduces noise and enables stable detection of the electrical characteristics of the component s.

[0030] However, the electrical characteristic measuring circuit (hereinafter sometimes simply referred to as the measuring circuit) 61 is a dedicated part of the measuring device 22, and can be called a test fixture (accessory). On the other hand, when the measuring circuit 61 acquires the electrical characteristics of the component s, if a current is supplied to the cables 58, 60, etc., electrical disturbances occur in parts other than the component s, which affects the measured electrical characteristics of the component s measured by the measuring unit 42. To reduce this effect, the disturbances (residual impedance, stray admittance) are found, the measured electrical characteristics are corrected, and the final electrical characteristics of the component s are acquired.

[0031] 9 shows an equivalent circuit of this measurement circuit (test fixture) 61. In the equivalent circuit, a resistor 160 and a coil 161 are located in series with the pair of probes 37 (the stator 34 and the mover 36), and a resistor 162 and a capacitor 163 are located in parallel with the pair of probes 37. The residual impedance of the measurement circuit 61 is the impedance occurring in series with the component s, and the stray admittance is the reciprocal of the impedance occurring between the pair of probes 37 in parallel with the component s. It can be assumed that the residual impedance occurs in the resistor 160 and the coil 161 in the equivalent circuit, and the stray admittance occurs in the resistor 162 and the capacitor 163.

[0032] The residual impedance Zs can be obtained as the impedance measured by the measuring unit 42 when the pair of probes 37 are in contact with each other. The residual impedance can be referred to as a short-circuit correction value. In this embodiment, the electric motor 66 is controlled to move the mover 36 closer to the stator 34, bringing them into contact with each other, and the solenoid valve device 80 is controlled to move the holder 32 back until it abuts against the stopper 92, separating it from the pair of probes 37. The holder 32 is made of a conductive material, but when it is retracted to its retracted end position behind the front end 36a of the mover 36, the distance between the mover 36 of the pair of probes 37 and the holder 32 is equal to or greater than the set distance. This reduces the influence of the holder 32 on the value measured by the measuring unit 42. In this state, the measuring unit 42 obtains a short-circuit correction value as the residual impedance Zs.

[0033] 9, the residual impedance Zs can be expressed as shown in the following equation: Rs is the resistance value that is an electrical characteristic of the resistor 160, and jLsω is the impedance that is an electrical characteristic of the coil 161. Zs=Rs+jLsω

[0034] The stray admittance can be obtained by measurement using the measurement unit 42 when the distance between the pair of probes 37 is equal to the length d of the electrode side of the component s whose electrical characteristics are to be measured (acquired). In this embodiment, as shown in FIG. 3(b), the electric motor 66 controls the distance between the mover 36 and the stator 34 to approach the length d of the electrode side of the component s whose electrical characteristics are to be measured next. Furthermore, the holder 32 is retracted to a position where it abuts against the stopper 92, similar to when acquiring a short correction value. In this state, the stray admittance is measured as an electrical characteristic between the mover 36 and the stator 34.

[0035] If the pair of probes 37 are spaced apart and the holder 32 is positioned between the pair of probes 37, the holder 32 will be close to or in contact with the pair of probes 37, and the presence of the holder 32 will affect the measurement value (stray admittance) by the measurement unit 42.

[0036] It is also desirable to use the same conditions as possible when measuring the stray admittance Yo and when measuring the electrical characteristics of the component s. For example, it is desirable to set the thickness of the air layer between the pair of probes 37 to be approximately the same. In other words, it is desirable to make the amount of air per unit length of the gap between the pair of probes 37 the same.

[0037] For the above reasons, when measuring the stray admittance Yo, the holder 32 is moved to the retracted end position where it abuts against the stopper 92 and is not located between the pair of probes 37. In this state, the holder 32 is spaced apart from the mover 36 by the set distance a or more, and the influence of the measuring unit 42 of the holder 32 on the measurement value can be reduced.

[0038] The stray admittance Yo can be expressed as shown in the following equation: where C is the capacitance of the capacitor 163, and Ro is the resistance value of the resistor 162. Yo=jCω+1 / Ro In the above equation, the resistance Ro is the air resistance value generated between the pair of spaced apart probes 37, and is therefore a very large value. Therefore, 1 / Ro can be considered to be almost zero. From the above, the stray admittance Yo can be expressed as shown in the following equation. Yo≒jCω

[0039] Furthermore, the following equation holds between the short correction value Zs, the open correction value Yo which is the stray admittance, the measured impedance Zm which is the actual measured value which is the measured electrical characteristic measured by the measuring unit 42 while the component s is held by the pair of probes 37, and the final impedance Zdut of the component s. Zdut(Zm-Zs)Yo+(Zm-Zs)=Zdut By rearranging the above equation, the final (corrected) impedance Zdut of component s can be expressed by the following equation. Zdut=(Zm-Zs) / {1-(Zm-Zs)Yo}···(2)

[0040] In this way, in this embodiment, the distance between the stator 34 and the mover 36 can be controlled to the length d of the electrode side of the component s, so that the stray admittance (open correction value) can be measured well.

[0041] The placement machine includes a control device 200. As shown in Fig. 11, the control device 200 includes a controller 202, which is mainly a computer, and a plurality of drive circuits 204. The controller 202 includes an execution unit 210, a memory unit 212, an input / output unit 214, etc. The input / output unit 214 is connected to the board transport and holding device 4, the component supply device 6, the head moving device 8, and the mover moving device 41 (electric motor 66), each via the drive circuit 204, and is also connected to the solenoid valve device 80 of the holder moving device 40. Also connected to the input / output unit 214 are the camera 20, the measurement unit 42, a display 216, a holder position sensor 220, a nozzle height sensor 222, a distance acquisition device 224, etc.

[0042] The distance acquisition device 224 is capable of acquiring the distance between the pair of probes 37 . The distance acquisition device 224 may include a position sensor capable of detecting the position of the facing surface 36f of the mover 36. Based on the position of the facing surface 36f of the mover 36, the distance between the facing surface 34f of the stator 34 and the facing surface 36f of the mover 36 can be acquired. The distance acquisition device 224 may also include a rotation speed sensor such as a resolver that can detect the rotation speed of the electric motor 66. Based on the cumulative number of rotations, which is the cumulative value of the rotation speed of the electric motor 66 from the retracted end position of the mover 36, it is possible to acquire the moving distance from the retracted end position of the mover 36. It is possible to acquire the position of the opposing surface 36f of the mover 36, and therefore the distance between the pair of probes 37. Furthermore, the distance acquisition device 224 may include a distance sensor that can optically or electromagnetically detect the distance between the opposing surface 36f of the mover 36 and the opposing surface 34f of the stator 34.

[0043] In this embodiment, the storage unit 212 stores the short correction value Zs, and also stores, as work plan information, information representing the shape of each of the multiple components s from which impedance is acquired (for example, information including the length d on the electrode side), default values ​​(nominal values) of the impedance of each of the multiple components s, and the like, which are input via an input device (not shown) or the like. Furthermore, this information can also be stored in a storage unit separate from the storage unit 212.

[0044] The electrical characteristics of the component s are acquired by executing an electrical characteristics acquisition program represented by the flowchart in Figure 12. The acquired electrical characteristics can be displayed on the display 216.

[0045] The measuring device 22 is always in a steady state. The mover 36 is at the retracted end position, and the holder 32 is at the advanced end position, i.e., at the position where it abuts against the stopper 90. The mover moving device 41 (electric motor 66) and the holder moving device 40 (solenoid valve device 80) are controlled based on the output signals of the distance acquisition device 224 and the holder position sensor 220, etc.

[0046] In step 1 (hereinafter abbreviated as S1, the same applies to other steps), it is determined whether a command to measure the electrical characteristics of component s has been issued. For example, if a command to measure the electrical characteristics of component s has been issued, such as when a changeover is performed, the determination is YES.

[0047] In S2, the length d of the electrode side of component s (next component s) whose electrical characteristics are to be measured is read from the memory unit 212, and in S3-6, the electric motor 66 is controlled. In S3, the electric motor 66 is started, and in S4, the distance acquisition device 224 acquires the distance x between the opposing surfaces 34f, 36f of the pair of probes, and in S5, it is determined whether the distance x is approximately the same as the length d. While the determination is NO, S4 and S5 are repeatedly executed. When the determination is YES in S5, the electric motor 66 is stopped in S6.

[0048] Next, in S7, the support table 32 is moved back until it abuts against the stopper 92, and in this state, in S8, the stray admittance is measured and set as the open correction value Yo. The open correction value Yo is stored in the memory unit 212. Then, in S9, the value of the electrical characteristic (e.g., impedance) of the next component s is measured. The execution of S9 is shown in the flowchart of FIG.

[0049] In S11, the holder moving device 40 moves the holder 32 to the forward end position where it abuts against the stopper 90, and the mover moving device 41 moves the mover 36 to the backward end position. In S12, the mounting head 16 picks up the component s and places it in the V-groove 44c. In S13, the electric motor 66 controls the mover 36 to approach the stator 34, thereby gripping the component s. The electric motor 66 is controlled so that the clamped state of the component s by the pair of probes 37 approaches a target clamped state determined for the component s. The target clamped state can be expressed by a target approach speed, which is a target value for the approach speed of the pair of probes 37 (the approach speed of the mover 36 relative to the stator 34), a target clamping force, which is a target value for the clamping force of the component s by the mover 36 and stator 34, and the like.

[0050] For example, when the part s is clamped by the pair of probes 37, the part s may be damaged. Also, the part s may be incorrectly clamped. In response to this, in this embodiment, the electric motor 66 is controlled to make the clamping force when the part s is clamped by the pair of probes 37 closer to the target clamping force, and to make the approach speed of the pair of probes 37 (the moving speed of the mover 36) closer to the target approach speed. This makes it possible to prevent damage to the part s, prevent incorrect clamping, etc.

[0051] Next, in S14, the holder 32 is moved back until it abuts against the stopper 92. The holder 32 reaches a position where it does not come into contact with the component s and the mover . In S15, the component s is released by the suction nozzle 18 and placed in the V-groove 44c, and a set static elimination time is awaited. The static elimination time is the time required to remove static electricity from the component s, and is determined in advance. When the elapsed time reaches the static elimination time, the determination in S15 becomes YES, and in S16, the measured impedance Zm, which is the actual value of the component s, is measured. Then, in S17, the open correction value Yo and short correction value Zs for the component s are read from the memory unit 212. In S18, the measured impedance Zm, the open correction value Yo, and the short correction value Zs are substituted into equation (2) to determine the corrected impedance Zdut of the component s. The corrected (final) impedance Zdut can be displayed on the display 216, or it can be compared with a default value and the comparison result can be displayed on the display 216.

[0052] Then, after the final impedance Zdut of component s is acquired, in S19, mover 36 is retracted, component s that was held between mover 36 and stator 34 is released, and holder 32 is retracted until it abuts stopper 92. This causes component s to drop and be stored in storage box 26 via disposal path 28. Then holder 32 is advanced and positioned between the pair of opposing surfaces 34f, 36f. A space is created above V-groove 44c, allowing component s to be placed thereon.

[0053] As described above, in this embodiment, the open circuit correction value is accurately acquired. As a result, the final impedance of the component s can be acquired with high accuracy. Even if the target component s has a small impedance, the impedance of the component s can be measured with high accuracy.

[0054] As described above, in this embodiment, the control device 200, the measuring device 22, etc. constitute an electrical characteristic acquisition device. The memory unit 212, the distance acquisition device 224, and the part of the control device 200 that stores and executes S3-S6 and S13 constitute a motor control unit. The open correction value measurement unit is made up of the measuring unit 42, the part of the control device 200 that stores and executes S8, etc., and the measurement unit 42, the part of the control device 200 that stores and executes S16, etc. constitute an actual measurement unit.

[0055] In the above embodiment, the case where the electrical characteristic acquisition device is provided in the placement machine has been described, but the measurement device may be used independently instead of being provided in the placement machine.

[0056] Furthermore, in the above embodiment, the case where impedance is acquired as an electrical characteristic has been described, but the electrical characteristic is not limited to impedance, and other electrical characteristics such as resistance value, reactance, etc. can also be acquired.

[0057] In addition to the aspects described above in the embodiments, the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0058] 22: Measuring device 32: Holder 34: Stator 36: Movable element 42: Measuring section 44: Component placement section 58, 60: Coaxial cable section 58a, 58b, 60a, 60b: Coaxial cable 61: Electrical characteristic measuring circuit 150: Same potential section 200: Control device 212: Memory section 224: Distance acquisition device Patentable invention

[0059] (1) An electrical characteristic acquisition device for acquiring electrical characteristics of an object, a pair of probes capable of measuring electrical characteristics of the object; an approaching / separating device including an electric motor as a drive source, which moves the pair of probes toward or away from each other; a motor control unit that controls the electric motor based on the object; An electrical characteristic acquisition device comprising:

[0060] The electrical characteristic acquisition device may be mounted on a mounting machine that picks up components as objects supplied by a component supply device and mounts them on a circuit board.

[0061] (2) The motor control unit controls the electric motor so that the distance between the pair of probes approaches the length of the object, The electrical characteristic acquisition device according to claim 1, further comprising an open correction value measurement unit that measures an open correction value, which is a value of the electrical characteristic between the pair of probes, when the distance between the pair of probes is made to approach the length of the object by the motor control unit and the object is not gripped by the pair of probes.

[0062] (3) The electrical characteristic acquisition device includes a storage unit that stores information about each of a plurality of objects; the information includes an electrode side length for each of the plurality of objects; The electrical characteristic acquisition device described in (2) above, wherein the motor control unit controls the electric motor so that the distance between the pair of probes approaches the length of the electrode side included in the information about the next object, which is the object whose electrical characteristics are to be acquired next, among the information about each of the plurality of objects stored in the memory unit.

[0063] (4) The electrical characteristic acquisition device according to (2) or (3) above, wherein the pair of probes grasp the object, corrects the actual measured value, which is the value of the electrical characteristic measured, based on the open correction value, and acquires the corrected electrical characteristic value.

[0064] (5) The motor control unit controls the electric motor so that a clamping state of the object by the pair of probes approaches a target clamping state determined based on the object, The electrical characteristic acquisition device according to any one of items (1) to (4), further comprising an actual measurement unit that measures an actual measurement value, which is a value of the electrical characteristic of the object, when the clamping state of the object by the pair of probes is brought closer to the target clamping state by the motor control unit.

[0065] The clamped (gripped) state is a state in which a pair of probes clamps an object. The clamped state can be expressed, for example, by the clamping force when the pair of probes clamps the object, or by the approach speed of the pair of probes to the object when clamping the object.

[0066] The clamping force can be controlled, for example, by controlling the distance between the pair of probes that clamp the object. Furthermore, controlling the clamping force can prevent damage to the object when it is clamped by the pair of probes. For example, if the object is relatively soft, it is desirable to reduce the clamping force.

[0067] Furthermore, by increasing the approach speed, the time required to clamp the object with the pair of probes and measure its electrical characteristics can be shortened, improving work efficiency. On the other hand, by decreasing the approach speed, it is possible to prevent the pair of probes from clamping the object incorrectly. For example, it is desirable to slow down the approach speed when the object is small or hard. As described above, by bringing the clamping state of the object by the pair of probes into a state close to the target clamping state determined for the object, it becomes possible to measure the electrical characteristics of the object satisfactorily.

Claims

1. An electrical characteristic acquisition device for acquiring electrical characteristics of an object, a pair of probes capable of measuring electrical characteristics of the object; an approaching / separating device including an electric motor as a drive source, which moves the pair of probes toward and away from each other; a motor control unit that controls the electric motor based on the object; An electrical characteristic acquisition device comprising:

2. the motor control unit controls the electric motor so that the distance between the pair of probes approaches the length of the object, 2. The electrical characteristic acquisition device according to claim 1, further comprising an open correction value measurement unit that measures an open correction value, which is a value of the electrical characteristic between the pair of probes, when the motor control unit causes the distance between the pair of probes to approach the length of the object and the object is not gripped by the pair of probes.

3. the electrical characteristic acquisition device includes a storage unit that stores information about each of the plurality of objects; the information includes an electrode side length for each of the plurality of objects; The electrical characteristic acquisition device described in claim 2, wherein the motor control unit controls the electric motor so that the distance between the pair of probes approaches the length of the electrode side included in the information about the next object, which is the object whose electrical characteristics are to be acquired next, among the information about each of the multiple objects stored in the memory unit.

4. the motor control unit controls the electric motor so that a clamping state of the object by the pair of probes approaches a target clamping state determined based on the object, 4. The electrical characteristic acquisition device according to claim 1, further comprising an actual measurement unit that measures an actual measurement value, which is a value of the electrical characteristic of the object, when the clamping state of the object by the pair of probes is brought closer to the target clamping state by the motor control unit.

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