Capacitance measurement device and capacitance measurement method

Abstract

Provided are a capacitance measurement device and a capacitance measurement method that can reduce stray capacitance generated at the tip portion of a probe and can measure the capacitance of an object to be measured with high accuracy. A capacitance measurement device is provided with: a pair of probes extending in the longitudinal direction and arranged substantially parallel to each other; a capacitance measuring device connected to the pair of probes; a shield plate having a flat plate shape and disposed such that a direction in which a first main surface and a second main surface, which face each other, extend is parallel to a direction in which the pair of probes extend, and the first main surface and the second main surface are sandwiched between the pair of probes; and insulating layers respectively provided on the first main surface and the second main surface of the shield plate, the capacitance measurement device being characterized in that the shield plate is disposed at all positions overlapping the pair of probes when viewed from a direction in which the pair of probes overlap each other.

Description

Technical Field

[0001] The present invention relates to an electrostatic capacitance measuring device and an electrostatic capacitance measuring method. Background Art

[0002] In recent years, the amount of data in communication equipment has increased, and capacitors are increasingly being used in high-frequency regions. In particular, in order to reduce variations in electrostatic capacitance, higher accuracy in the measurement of electrostatic capacitance is required.

[0003] As a method for measuring electrostatic capacitance, for example, Patent Document 1 discloses a method of disposing an insulating layer between probes.

[0004] Prior Art Literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2004-144663

[0007] However, the measurement method as disclosed in Patent Document 1 has a problem in that stray capacitance is generated at the tip portion of the probe and thus the capacitance of the object to be measured cannot be measured with high accuracy. Summary of the invention

[0008] Problem that the invention aims to solve

[0009] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an electrostatic capacitance measuring device capable of reducing stray capacitance generated at the tip portion of a probe and measuring the electrostatic capacitance of a measurement object with high accuracy.

[0010] Means used to solve problems

[0011] The electrostatic capacitance measuring device of the present invention comprises: a pair of probes extending in the long side direction and arranged to be approximately parallel; an electrostatic capacitance measuring device connected to the pair of probes; a shielding plate in the form of a flat plate and arranged so that the directions in which the first and second main surfaces facing each other extend are parallel to the direction in which the pair of probes extend, and the first and second main surfaces are sandwiched between the pair of probes; and an insulating layer respectively provided on the first and second main surfaces of the shielding plate. The electrostatic capacitance measuring device is characterized in that the shielding plate is provided at all positions overlapping the pair of probes when viewed from the direction in which the pair of probes overlap each other.

[0012] Effects of the Invention

[0013] According to the present invention, it is possible to provide an electrostatic capacitance measuring device capable of reducing stray capacitance generated at the tip portion of a probe and measuring the electrostatic capacitance of a measurement object with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a diagram schematically showing an example of the electrostatic capacitance measuring device of the present invention.

[0015] Figure 2 yes Figure 1 AA line section view in.

[0016] Figure 3 It is schematically shown Figure 1 A perspective view showing the relationship between a shield plate and a pair of probes in the electrostatic capacitance measuring device shown.

[0017] Figure 4 It is a perspective view schematically showing another example of the electrostatic capacitance measuring device of the present invention.

[0018] Figure 5 It shows that the Figure 4 A side view of an example of a capacitance measuring method using the capacitance measuring device shown.

[0019] Figure 6 It is schematically shown in Figure 5 FIG. 1 is a diagram showing a state in which a pair of probes are brought into contact with a pair of external electrodes in the electrostatic capacitance measuring device shown.

[0020] Figure 7 This is a perspective view schematically showing the relationship between a shield plate and a pair of probes in still another example of the electrostatic capacitance measuring device of the present invention.

[0021] Figure 8 It is a schematic diagram showing the use of Figure 7 1 is a side view of an example of a method of measuring the capacitance of a multilayer ceramic capacitor using the capacitance measuring apparatus shown.

[0022] Fig. 9 It is schematically shown in Figure 8 FIG. 1 is a diagram showing a state in which a pair of probes are brought close to a multilayer ceramic capacitor in a capacitance measuring apparatus shown.

[0023] Fig.10 It is schematically shown in Fig. 9 FIG. 1 is a diagram showing a state in which a pair of probes are driven toward a multilayer ceramic capacitor using a probe driving mechanism in the capacitance measuring apparatus shown.

[0024] Fig.11 It is a plan view schematically showing another example of the electrostatic capacitance measuring device of the present invention.

[0025] Description of Reference Numerals

[0026] 1, 2, 3, 4 Electrostatic capacitance measuring device

[0027] 10A pair of probes

[0028] Projection diagram of 10A and 10B probes

[0029] 10a, 10b The front end of the projection image of the probe

[0030] 11The 1st probe

[0031] 11a Tip of the first probe

[0032] 12 The second probe

[0033] 12a Tip of the second probe

[0034] 20 Shielding plate

[0035] 20a 1st main surface of shielding plate

[0036] 20b Second main surface of shielding plate

[0037] 20c Front end of the shield plate (side surface of the shield plate in the +Y direction)

[0038] 30 insulation layers

[0039] 31 1st insulation layer

[0040] 32 2nd insulation layer

[0041] 100-layer ceramic capacitor

[0042] 101 body

[0043] 101a The first main surface of the main body

[0044] 101b The second main surface of the main body

[0045] 101c The first end face of the body

[0046] 101d The second end face of the body

[0047] The first side of the 101e body

[0048] The second side of the 101f body

[0049] 102, 103 external electrodes

[0050] 110 conveyor

[0051] Holes 110a, 110b, 110c

[0052] 120 parts feeder

[0053] 130 Linear Feeder

[0054] 140 recess

[0055] 150 measurement area

[0056] 160 1st discharge area

[0057] 170 2nd discharge area

[0058] tFolded back thickness of external electrode

[0059] L 1 Shield plate protrusion

[0060] L 2 The amount of shield plate protrusion when the probe contacts the shield plate. DETAILED DESCRIPTION

[0061] The following is an explanation of the electrostatic capacitance measuring device of the present invention. However, the present invention is not limited to the following structure, and can be appropriately modified and applied within the scope of the main purpose of the present invention. In addition, the structure obtained by combining two or more of the desired structures of the present invention described below is also the present invention.

[0062] In this specification, terms that express the relationship between elements (for example, "opposite", "orthogonal", etc.) and terms that express the shape of an element (for example, "rectangular", etc.) do not express only strict meanings, but rather mean essentially the same range, for example, also including differences of about a few percent.

[0063] The drawings shown below are schematic diagrams, and their dimensions, aspect ratios, and other scales may differ from those of actual products.

[0064] [Electrostatic capacitance measuring device]

[0065] The electrostatic capacitance measuring device of the present invention comprises: a pair of probes extending in the long side direction and arranged to be approximately parallel; an electrostatic capacitance measuring device connected to the pair of probes; a shielding plate in the form of a flat plate and arranged so that the directions in which the first and second main surfaces facing each other extend are parallel to the direction in which the pair of probes extend, and the first and second main surfaces are sandwiched between the pair of probes; and an insulating layer respectively provided on the first and second main surfaces of the shielding plate. The electrostatic capacitance measuring device is characterized in that the shielding plate is provided at all positions overlapping the pair of probes when viewed from the direction in which the pair of probes overlap each other.

[0066] Figure 1 This is a diagram schematically showing an example of the electrostatic capacitance measuring device of the present invention.

[0067] Figure 1 The illustrated capacitance measurement device 1 includes a pair of probes 10 , a capacitance measurement device (not shown) connected to the pair of probes, a shielding plate 20 , and an insulating layer 30 .

[0068] A pair of probes 10 are included in the long side direction ( Figure 1 The first probe 11 and the second probe 12 extend in the Y direction (shown in FIG. 1 ) and are arranged substantially parallel to each other.

[0069] The shield plate 20 is in the shape of a flat plate having a first main surface 20 a and a second main surface 20 b facing each other.

[0070] The first main surface 20a and the second main surface 20b of the shielding plate 20 are parallel to Figure 1 The planes (XY planes) in the X direction and the Y direction shown are parallel. Therefore, the direction in which the first main surface 20a and the second main surface 20b of the shield plate 20 extend is parallel to the direction (Y direction) in which the pair of probes 10 extend.

[0071] The shield plate 20 is disposed so that the first main surface 20 a and the second main surface 20 b are sandwiched between the pair of probes 10 .

[0072] The so-called "the first main surface and the second main surface are sandwiched between the pair of probes" refers to a state in which the first main surface and the second main surface of the shielding plate are sandwiched by the pair of probes so as to face the probes. In this state, when the pair of probes and the shielding plate are viewed from the direction in which the probes extend, the direction connecting the pair of probes is substantially orthogonal to the direction in which the first main surface and the second main surface of the shielding plate extend.

[0073] Figure 2 yes Figure 1 AA line section view in.

[0074] like Figure 2 As shown, the first main surface 20 a of the shield plate 20 faces the first probe 11 constituting the pair of probes 10 . The second main surface 20 b of the shield plate 20 faces the second probe 12 constituting the pair of probes 10 .

[0075] The direction (Z direction) connecting the first probe 11 and the second probe 12 constituting the pair of probes 10 is substantially orthogonal to the direction (XY plane) in which the first main surface 20 a and the second main surface 20 b of the shield plate 20 extend.

[0076] The insulating layer 30 is provided on each of the first main surface 20 a and the second main surface 20 b of the shield plate 20 .

[0077] The insulating layer 30 provided on the first main surface 20 a of the shield plate 20 is a first insulating layer 31 , and the insulating layer 30 provided on the second main surface 20 b of the shield plate 20 is a second insulating layer 32 .

[0078] Since the first main surface 20 a and the second main surface 20 b of the shield plate 20 , which are main surfaces, are covered with the insulating layer 30 , it can be said that the shield plate 20 is sandwiched by the insulating layer 30 .

[0079] The first insulating layer 31 and the second insulating layer 32 are collectively referred to as a pair of insulating layers.

[0080] Figure 3 It is schematically shown Figure 1 A perspective view showing the relationship between a shield plate and a pair of probes in the electrostatic capacitance measuring device shown.

[0081] like Figure 3 As shown, when viewed from the direction (Z direction) in which the first probe 11 and the second probe 12 constituting the pair of probes 10 overlap each other, the shield plate 20 is arranged at all positions overlapping the pair of probes 10 .

[0082] exist Figure 3 In FIG. 1 , a projection diagram of the first probe 11 and a projection diagram of the second probe 12 are shown using the region indicated by 10A.

[0083] In the Y direction, the projection Fig.10 The tip 10a of A coincides with the tip 20c of the side surface of the shield plate 20 in the +Y direction. Fig.10 A is entirely disposed on the shielding plate 20 and does not protrude from the shielding plate 20 .

[0084] In addition, the front end 20 c of the side surface of the shield plate 20 in the +Y direction is also referred to as the front end of the shield plate 20 .

[0085] exist Figure 3 In the embodiment, the front end 11a of the first probe 11, the front end 12a of the second probe 12, and the front end 20c of the shielding plate 20 are located on the same ZX plane. That is, in the Y direction, the front end 11a of the first probe 11, the front end 12a of the second probe 12, and the front end 20c of the shielding plate 20 are coplanar.

[0086] In addition, the tip of the first probe and the tip of the second probe are collectively referred to simply as the tip of the probe.

[0087] like Figure 3 As shown, in the electrostatic capacitance measuring device of the present invention, when viewed from the direction in which a pair of probes overlap each other, shielding plates are arranged at all positions overlapping with the pair of probes, so that the stray capacitance generated at the front end portion of the probes can be reduced, and the electrostatic capacitance of the measured object can be measured with high precision.

[0088] (Probe)

[0089] The probe is preferably formed from a conductor.

[0090] As the conductor constituting the probe, for example, copper, an alloy containing copper, etc. can be cited. In addition, a super steel material can also be used.

[0091] The probe has a rod shape extending in the longitudinal direction.

[0092] One end of the probe is connected to a capacitance measuring device.

[0093] The other end of the probe is a portion that comes into contact with a measurement target such as a multilayer ceramic capacitor, and is also referred to as a tip of the probe.

[0094] The diameter of the probe is not particularly limited, but is preferably 30 μm or more and 260 μm or less.

[0095] However, it is more preferable to adjust the diameter of the probe in accordance with the size of the multilayer ceramic capacitor to be measured.

[0096] When the size of the multilayer ceramic capacitor to be measured is about 0.6 mm in the length direction and about 0.3 mm in the width direction and thickness direction, the diameter of the probe is preferably 140 μm or more and 260 μm or less.

[0097] When the size of the multilayer ceramic capacitor to be measured is about 0.4 mm in the length direction and about 0.2 mm in the width direction and thickness direction, the diameter of the probe is preferably 60 μm or more and 100 μm or less.

[0098] When the size of the multilayer ceramic capacitor to be measured is about 0.2 mm in the length direction and about 0.1 mm in the width direction and thickness direction, the diameter of the probe is preferably 30 μm or more and 90 μm or less.

[0099] When the size of the multilayer ceramic capacitor to be measured is about 0.1 mm in the length direction and about 0.05 mm in the width direction and thickness direction, the diameter of the probe is preferably 30 μm or more and 60 μm or less.

[0100] In this specification, the "diameter of the probe" refers to the diameter of the portion other than the end of the probe.

[0101] When the probe has a non-circular shape such as a prism, the area equivalent diameter of the probe in a cut surface when the probe is cut along a plane parallel to a plane perpendicular to the extending direction of the probe is set as the diameter of the probe.

[0102] The shape of the tip of the probe is not particularly limited, but is preferably a protruding shape like a cone.

[0103] The shape of the cone may be a pyramid such as a triangular pyramid, a quadrangular pyramid, a hexagonal pyramid, or a circular cone. In addition, the cone may be a frustum with its front end portion removed.

[0104] Furthermore, the shape of the tip of the probe may be star-shaped when viewed from the extending direction of the probe, or may be the same shape as the tip of a flat-blade screwdriver.

[0105] Regardless of the diameter of the probe, the tip diameter of the probe is preferably 1 μm or more and 10 μm or less, more preferably 3 μm or more and 7 μm or less, and further preferably 5 μm.

[0106] The tip diameter of the probe can be obtained as a circle equivalent diameter of the area of ​​a portion of the tip-most portion of the probe that overlaps with a plane perpendicular to the direction in which the probe extends.

[0107] For example, when the tip of the probe is shaped like a frustum and the upper base of the frustum is perpendicular to the direction in which the probe extends, the circle-equivalent diameter of the area of ​​the upper base is set as the tip diameter of the probe.

[0108] The capacitance measuring device of the present invention may include two pairs of probes.

[0109] In this case, it is preferable that a shielding plate be disposed between two sets of “a pair of probes”.

[0110] In this case, the two unpaired probes disposed on the same side of the shield plate are preferably set to the same polarity. If the two unpaired probes have the same polarity, stray capacitance is less likely to occur between the two probes, so the measurement accuracy of the electrostatic capacitance is less likely to decrease.

[0111] The probe may be surrounded by a cylindrical insulator or the like as necessary.

[0112] (Shielding plate)

[0113] The shield plate may be made of any material as long as it is a conductor.

[0114] As a conductor constituting the shield plate, copper etc. are mentioned, for example.

[0115] Preferably, the shielding plate contains copper as a main component.

[0116] The thickness of the shielding plate is not particularly limited, but is preferably set to, for example, 0.01 mm or more and 0.5 mm or less.

[0117] Preferably, the front end of the shielding plate protrudes further than the front end of the probe.

[0118] In addition, the front end of the shield plate refers to the end of the shield plate in the direction in which the probe extends.

[0119] Preferably, the shielding plate is grounded, or connected to be capacitively coupled to a ground electrode.

[0120] (Insulation layer)

[0121] Examples of the material constituting the insulating layer include insulating materials such as barrier films and resins.

[0122] The thickness of the insulating layer is not particularly limited, but may be 0.4 μm or more and 30 μm or less.

[0123] The insulating layer may not cover the entire first main surface and the entire second main surface of the shield plate.

[0124] In other words, portions not covered by the insulating layer may exist on the first main surface and the second main surface of the shield plate.

[0125] The insulating layer may also cover the side surfaces of the shielding plate. However, it is preferred that the front end of the shielding plate is not covered by the insulating layer.

[0126] (Capacitance measuring device)

[0127] A pair of probes is connected to a capacitance measuring device.

[0128] The method of connecting the pair of probes and the capacitance measuring device is not particularly limited, and for example, they may be connected via a lead wire.

[0129] It is preferable that the capacitance measuring device is subjected to various calibrations such as STD calibration, OPEN calibration, and short circuit calibration before measuring the capacitance.

[0130] (Probe drive mechanism)

[0131] The capacitance measuring device of the present invention may further include a probe driving mechanism that moves the tips of the pair of probes in the longitudinal direction.

[0132] However, when viewed from the direction in which the pair of probes overlap each other, the range in which the pair of probes can move is limited to the range in which the shielding plates are arranged at all positions overlapping the pair of probes.

[0133] (Shielding plate drive mechanism)

[0134] The capacitance measuring device of the present invention may further include a shield plate driving mechanism that moves the shield plate in the longitudinal direction.

[0135] However, when viewed from the direction in which the pair of probes overlap each other, the range in which the shield plate can move is limited to the range in which the shield plate is arranged at all positions overlapping the pair of probes.

[0136] The probe driving mechanism and the shield plate driving mechanism may be used together.

[0137] (Conveyor table)

[0138] The capacitance measuring device of the present invention may include a conveying table for conveying the object to be measured.

[0139] The conveyor table is preferably made of an insulating material such as ceramics.

[0140] The conveyor table may be provided with holes for allowing the probe and the shielding plate to pass therethrough.

[0141] The transport stage may be provided with a holding mechanism for fixing (holding) the object to be measured when measuring the electrostatic capacitance.

[0142] The method of fixing the measurement object by the holding mechanism is not particularly limited, and the measurement object may be fixed by means of vacuum adsorption or the like, or may be fixed by grasping the measurement object.

[0143] Alternatively, the object to be measured may be fixed by accommodating the object to be measured in a recessed portion capable of accommodating a part or the entirety of the object to be measured.

[0144] [Electrostatic capacitance measurement method]

[0145] The electrostatic capacitance measuring method of the present invention is an electrostatic capacitance measuring method for measuring the electrostatic capacitance of a stacked ceramic capacitor using the electrostatic capacitance measuring device of the present invention, and is characterized in that the stacked ceramic capacitor has a substantially rectangular main body and external electrodes, the main body having two main surfaces opposite to each other in a stacking direction, two end surfaces opposite to each other in a long side direction orthogonal to the stacking direction, and two side surfaces opposite to each other in a width direction orthogonal to the stacking direction and the long side direction, the external electrodes are respectively formed on the two end surfaces, and the electrostatic capacitance is measured by the pair of probes contacting the pair of external electrodes.

[0146] Figure 4 It is a perspective view schematically showing another example of the electrostatic capacitance measuring device of the present invention.

[0147] in addition, Figure 4 This is also an example of the capacitance measuring method of the present invention, in which the capacitance of the multilayer ceramic capacitor 100 is measured using the capacitance measuring device 2 as the capacitance measuring device of the present invention.

[0148] The capacitance measuring device 2 is the same as the above-described capacitance measuring device 1 except that it further includes a conveyor table 110 .

[0149] The multilayer ceramic capacitor 100 is transported along the transport table 110 .

[0150] The conveyance stage 110 on the conveyance path of the multilayer ceramic capacitor 100 is provided with holes 110 a , 110 b , and 110 c .

[0151] The hole 110 a is a hole through which the shield plate 20 sandwiched between the insulating layers 30 passes.

[0152] The holes 110 b and 110 c are holes through which the first probe 11 and the second probe 12 pass, respectively.

[0153] The multilayer ceramic capacitor 100 includes a main body 101 and a pair of external electrodes 102 and 103 .

[0154] The main body 101 is a roughly rectangular parallelepiped having two main surfaces (the first main surface 101a and the second main surface 101b) opposing each other in the stacking direction (Y direction), two end surfaces (the first end surface 101c and the second end surface 101d) opposing each other in the long side direction (Z direction) perpendicular to the stacking direction, and two side surfaces (the first side surface 101e and the second side surface 101f) opposing each other in the width direction (X direction) perpendicular to the stacking direction and the long side direction.

[0155] The external electrode 102 is provided to cover the first end surface 101c of the body 101 and a portion of the first main surface 101a, the second main surface 101b, the first side surface 101e, and the second side surface 101f adjacent to the first end surface 101c across the ridgeline.

[0156] The external electrode 103 is provided to cover the second end surface 101d of the body 101 and a portion of the first main surface 101a, the second main surface 101b, the first side surface 101e, and the second side surface 101f adjacent to the second end surface 101d across the ridgeline.

[0157] Therefore, on the first main surface 101a, the second main surface 101b, the first side surface 101e, and the second side surface 101f of the main body 101, there are respectively areas where the external electrode 102 is provided, areas where the external electrode 103 is provided, and areas where no external electrode is provided and the surface of the main body 101 is exposed.

[0158] The external electrodes arranged on the surfaces other than the first end face 101c and the second end face 101d of the main body 101, i.e., the first main face 101a, the second main face 101b, the first side face 101e, and the second side face 101f are also referred to as folded parts, and the thickness of the folded parts is also referred to as folded thickness.

[0159] Figure 5 It shows that the Figure 4 A side view of an example of a capacitance measuring method using the capacitance measuring device shown.

[0160] like Figure 5 As shown, a pair of probes 10 constituting the capacitance measuring device 1 and a shield plate 20 sandwiched between insulating layers 30 are arranged below the multilayer ceramic capacitor 100 with the conveyor stage 110 interposed therebetween.

[0161] The tip 11a of the first probe 11, the tip 12a of the second probe 12, and the tip 20c of the shielding plate 20 constituting the pair of probes 10 are present on the same plane ( Figure 5 In the middle, through the dotted line ZX 0 The ZX plane of the .

[0162] Figure 6 It is schematically shown in Figure 5 FIG. 1 is a diagram showing a state in which a pair of probes are brought into contact with a pair of external electrodes in the electrostatic capacitance measuring device shown.

[0163] Figure 6 The status shown is from Figure 5 The state shown is a state in which a pair of probes 10 and a shield plate 20 sandwiched by insulating layers 30 are brought close to the multilayer ceramic capacitor 100 .

[0164] like Figure 6 As shown, the second probe 12 abuts against the external electrode 102 of the multilayer ceramic capacitor 100 , and the first probe 11 abuts against the external electrode 103 .

[0165] The capacitance of the multilayer ceramic capacitor 100 is measured by a capacitance measuring device (not shown) connected to the first probes 11 and the second probes 12 by bringing the pair of probes 10 into contact with the external electrodes 103 and 102 , respectively.

[0166] Figure 6 The relationship between the pair of probes 10 and the shielding plate 20 is Figure 3 The same is true for the capacitance measuring device 1 shown.

[0167] Therefore, in Figure 6 In the illustrated state, it can be said that the shielding plate 20 is disposed at all positions overlapping the pair of probes 10 when viewed from the direction (Z direction) in which the pair of probes 10 overlap each other.

[0168] Therefore, the stray capacitance generated at the tip portions of the pair of probes can be reduced, and the electrostatic capacitance can be measured with high accuracy.

[0169] In the electrostatic capacitance measuring method of the present invention, preferably, a pair of external electrodes are also formed across the ridge portion on at least one of the four surfaces other than the two end surfaces, and the electrostatic capacitance is measured by bringing a pair of probes into contact with the portion of a pair of external electrodes formed across the ridge portion from the two end surfaces.

[0170] exist Figure 4 , Figure 5 as well as Figure 6In the illustrated multilayer ceramic capacitor 100, a pair of external electrodes 102 and 103 are formed across the ridgeline on all four surfaces (first main surface 101a, second main surface 101b, first side surface 101e, second side surface 101f) except two end surfaces (first end surface 101c, second end surface 101d).

[0171] Then, the pair of probes 10 are in contact with the folded-back portions of the pair of external electrodes 102 and 103 formed on the first main surface 101 a , respectively.

[0172] In addition, Figure 4 , Figure 5 as well as Figure 6 In the embodiment, the probe is brought into contact with the multilayer ceramic capacitor 100 from the lower side of the conveyor stage 110 , but the direction in which the probe is brought into contact with (approached to) the multilayer ceramic capacitor is not particularly limited.

[0173] Therefore, for example, the probe needle may be brought into contact with the multilayer ceramic capacitor from the upper side or the lateral side.

[0174] In the electrostatic capacitance measuring method of the present invention, it is preferred that, when a pair of probes are in contact with a pair of external electrodes, the shielding plate protrudes further toward the stacked ceramic capacitor than the front ends of the pair of probes, so that the distance from the front end of the shielding plate to the main body when the pair of probes are in contact is less than the thickness of the external electrodes with which the pair of probes are in contact.

[0175] Figure 7 This is a perspective view schematically showing the relationship between a shield plate and a pair of probes in still another example of the electrostatic capacitance measuring device of the present invention.

[0176] Figure 7 The illustrated electrostatic capacitance measuring device 3 is similar to the above-described electrostatic capacitance measuring device 2 except that the shielding plate 20 protrudes further toward the multilayer ceramic capacitor 100 than the tips of the pair of probes 10 .

[0177] exist Figure 7 In FIG. 1 , a projection diagram of the first probe 11 and a projection diagram of the second probe 12 are shown using the region indicated by 10B.

[0178] When the first probe 11 constituting the pair of probes 10 is projected onto the shield plate 20 in the Z direction, the projection of the first probe 11 Fig.10 B is entirely disposed on the shielding plate 20 and does not protrude. Similarly, when the second probe 12 constituting the pair of probes 10 is projected onto the shielding plate 20 in the Z direction, the projection of the second probe 12 Fig.10 B is entirely disposed on the shielding plate 20 and does not protrude therefrom.

[0179] Therefore, in the direction in which the first probe 11 and the second probe 12 constituting the pair of probes 10 overlap each other ( Figure 7 It can be said that the shielding plate 20 is arranged at all positions overlapping with the pair of probes 10 when viewed in the middle Z direction.

[0180] And, if Figure 7 As shown, the projections of the first probe 11 and the second probe 12 Fig.10 There is no projection between the front end 10b of B and the front end 20c of the shield plate 20. Fig.10 Area of ​​B.

[0181] The tip 11a of the first probe 11 and the tip 12a of the second probe 12 are located on the same ZX plane ( Figure 7 In the middle, through the dotted line ZX 2 However, the front end 20c of the shielding plate 20 and the front ends 11a of the first probes 11 and 12a of the second probes 12 do not exist in the same ZX plane.

[0182] The front end 20c of the shielding plate 20 is located on a ZX plane (through a dotted line ZX 2 plane) is closer to the +Y direction than other ZX planes ( Figure 7 In the middle, through the dotted line ZX 1 on the ZX plane).

[0183] Therefore, the projection Fig.10 The front end 10b of B does not overlap with the front end 20c of the shielding plate 20. The front end 20c of the shielding plate 20 is larger than the projection. Fig.10 The front end 10b of B protrudes in the +Y direction by a given length.

[0184] Figure 8 It is a schematic diagram showing the use of Figure 7 1 is a side view of an example of a method of measuring the capacitance of a multilayer ceramic capacitor using the capacitance measuring apparatus shown.

[0185] like Figure 8 As shown, a pair of probes 10 and a shield plate 20 constituting the capacitance measuring device 3 are arranged below the multilayer ceramic capacitor 100 with the conveyance stage 110 interposed therebetween.

[0186] The front end 20c of the shielding plate 20 protrudes in the +Y direction by a given length from the front ends of the pair of probes 10 (the first probe 11 and the second probe 12). The distance L from the front end 20c of the shielding plate 20 to the front ends (11a, 12a) of the probes in the Y direction at this time is 1 Also called shield plate protrusion.

[0187] From this state, the pair of probes 10 and the shielding plate 20 constituting the capacitance measuring device 3 are moved closer to the multilayer ceramic capacitor 100 .

[0188] Fig. 9 It is schematically shown in Figure 8 FIG. 1 is a diagram showing a state in which a pair of probes are brought close to a multilayer ceramic capacitor in a capacitance measuring apparatus shown.

[0189] Fig. 9 The status shown is from Figure 8 The state shown is a state in which a pair of probes 10 and a shield plate 20 sandwiched by insulating layers 30 are brought close to the multilayer ceramic capacitor 100 .

[0190] like Figure 8 As shown in the electrostatic capacitance measuring device 3, when the front end 20c of the shield plate 20 protrudes further in the +Y direction than the front ends of the pair of probes, as shown in FIG. Fig. 9 As shown, even if the pair of probes and the shielding plate 20 are brought close to the multilayer ceramic capacitor 100 , the shielding plate 20 may come into contact with the body 101 constituting the multilayer ceramic capacitor 100 before the pair of probes 10 come into contact with the external electrodes 102 , 103 .

[0191] in addition, Fig. 9 Shield plate protrusion L 1 Before bringing a pair of probes close to each other Figure 8 Shield plate protrusion L 1 same.

[0192] In this state, the pair of probes 10 cannot be brought into contact with the external electrodes 102 and 103 .

[0193] If the capacitance measuring device of the present invention includes a probe driving mechanism, even in the above-mentioned case, the pair of probes can be brought into contact with the external electrodes.

[0194] Fig.10 It is schematically shown in Fig. 9 FIG. 1 is a diagram showing a state in which a pair of probes are driven toward a multilayer ceramic capacitor using a probe driving mechanism in the capacitance measuring apparatus shown.

[0195] like Fig.10 As shown, by using a probe driving mechanism (not shown), the pair of probes 10 can be further moved in the +Y direction without changing the position of the shield plate 20 , and the pair of probes 10 can be brought into contact with the external electrodes 102 , 103 .

[0196] In a state where the pair of probes 10 are in contact with the external electrodes 102 and 103 , the front end 20 c of the shield plate 20 protrudes further to the +Y direction side than the front ends of the pair of probes 10 .

[0197] like Fig.10As shown, the distance L between the tip 20c of the shield plate and the tip (11a, 12a) of the probes in the direction (Y direction) in which the pair of probes 10 extend when the pair of probes 10 are in contact with the external electrodes 102, 103 of the multilayer ceramic capacitor 100 is 2 It is also called the amount of shield plate protrusion when the probe contacts the shield plate.

[0198] If the front end 20c of the shielding plate 20 protrudes further toward the +Y direction than the front ends of the pair of probes 10, the electric field generated from the front ends of the pair of probes 10 and winding around the multilayer ceramic capacitor 100 can be cut off by the shielding plate 20. Therefore, compared with the case where the front ends 11a and 12a of the pair of probes 10 and the front end 20c of the shielding plate 20 are coplanar, the stray capacitance generated at the front ends of the probes can be further reduced.

[0199] exist Fig.10 In the capacitance measuring device 3 shown, the front end 20c of the shielding plate 20 is in contact with the body 101 constituting the multilayer ceramic capacitor 100. Therefore, the distance from the front end 20c of the shielding plate 20 to the body 101 constituting the multilayer ceramic capacitor 100 in the direction (Y direction) in which the pair of probes 10 extend is zero.

[0200] When the front end 20c of the shield plate 20 is in contact with the body 101 constituting the multilayer ceramic capacitor 100, the electric field generated from the front ends of the pair of probes 10 and directed toward the multilayer ceramic capacitor 100 can be cut off to the maximum extent by the shield plate 20. Therefore, the stray capacitance generated at the front end of the probes can be particularly reduced.

[0201] In addition, at this time, the shield plate protrusion amount L 2 The folded back thickness of the external electrodes 102 and 103 that abut against the pair of probes 10 ( Fig.10 , the thickness indicated by t) is equal.

[0202] Here, the folded back thickness t of the external electrodes 102 and 103 is equal to the sum of the distance from the front end of the pair of probes 10 to the front end 20 c of the shield plate 20 (shield plate protrusion amount) and the distance from the front end 20 c of the shield plate 20 to the body 101 when the pair of probes 10 abut against the external electrodes 102 and 103.

[0203] Therefore, if the distance between the front end 20c of the shielding plate 20 and the main body 101 when the pair of probes 10 abut against the external electrodes 102, 103 is set to be less than the folded back thickness t of the external electrodes 102, 103 abutted against by the pair of probes 10, the shielding plate protrusion L is 2 The folded-back thickness t of the external electrodes 102 and 103 with which the pair of probes 10 abut is set to be equal to or less than that.

[0204] In addition, as long as the distance between the front end 20c of the shielding plate 20 and the body 101 is less than the folded back thickness t of the external electrodes 102, 103 abutting against the pair of probes 10, the shielding plate protrusion L 2 When the thickness t of the folded-back outer electrodes 102 and 103 with which the pair of probes 10 abut is equal to or smaller than that, the above-mentioned effect is achieved.

[0205] Therefore, as described above, it is not necessarily necessary to provide a probe driving mechanism. This will be described below.

[0206] exist Figure 8 In the state shown, before the pair of probes 10 come into contact with the external electrodes 102 and 103 of the multilayer ceramic capacitor 100, the shield plate protrudes by an amount L 1 is larger than the folded back thickness t of the external electrodes 102 and 103. Therefore, if the pair of probes 10 and the shielding plate 20 are moved simultaneously, the shielding plate 20 abuts against the body 101 before the pair of probes 10 abut against the external electrodes 102 and 103. Therefore, it is necessary to reduce the protrusion of the shielding plate by moving the pair of probes 10 in the +Y direction with the shielding plate 20 fixed by using the probe driving mechanism.

[0207] In contrast, Figure 8 In the state shown, the shield plate protrudes by an amount L 1 When the shield plate protrusion is less than the folded back thickness t of the external electrodes 102 and 103, for example, the shield plate protrusion amount is not L 1 But L 2 In the case of Fig. 9 Arrived at the status shown Fig.10 Therefore, no probe drive mechanism is required.

[0208] In addition, the shielding plate protrusion when the probe abuts is preferably less than the folded back thickness of the external electrode abutted by the probe, and more preferably equal to the folded back thickness of the external electrode abutted by the probe. In other words, the distance from the front end of the shielding plate to the body when the probe abuts is preferably less than the folded back thickness of the external electrode abutted by the probe, and more preferably zero.

[0209] Fig.11 It is a plan view schematically showing another example of the electrostatic capacitance measuring device of the present invention.

[0210] Fig.11 The illustrated capacitance measuring device 4 includes a parts feeder 120 , a linear feeder 130 , a conveyance table 110 , a measuring area 150 provided on the conveyance table 110 , a first discharge area 160 , and a second discharge area 170 .

[0211] Concave portions 140 into which the multilayer ceramic capacitor 100 can be fitted are provided at equal intervals along the circumference of the conveyance table 110 .

[0212] The stored multilayer ceramic capacitors 100 are sequentially conveyed by the component feeder 120 and the linear feeder 130 so as to fit into the recessed portions 140 on the conveyance table 110 .

[0213] The multilayer ceramic capacitors 100 arranged to fit into the recessed portions 140 are sequentially transported to the measurement area 150 by the rotation of the transport stage 110 .

[0214] The capacitance of the multilayer ceramic capacitor 100 conveyed to the measuring area 150 is measured. The method of measuring the capacitance is the same as that of the capacitance measuring device of the present invention described above.

[0215] The multilayer ceramic capacitors 100 may be sorted into the first discharge area 160 and the second discharge area 170 based on the measurement result of the electrostatic capacitance in the measurement area 150 .

[0216] For example, the multilayer ceramic capacitor 100 determined to be defective as a result of the capacitance measurement in the measurement area 150 may be removed from the conveyance table 110 in the first discharge area 160 .

[0217] Furthermore, for example, the multilayer ceramic capacitor 100 determined as a non-defective product after the capacitance is measured in the measuring area 150 may be transported from the transport stage 110 to the next production line in the second discharge area 170 .

[0218] (Multilayer Ceramic Capacitors)

[0219] The multilayer ceramic capacitor used as the object of capacitance measurement in the capacitance measuring device and the capacitance measuring method of the present invention is a multilayer ceramic capacitor having a pair of external electrodes formed on the end surface.

[0220] A stacked ceramic capacitor preferably has a roughly rectangular body and external electrodes, the body having two main surfaces opposite to each other in the stacking direction, two end surfaces opposite to each other in the long side direction orthogonal to the stacking direction, and two side surfaces opposite to each other in the width direction orthogonal to the stacking direction and the long side direction, the external electrodes being formed on the two end surfaces respectively.

[0221] When the multilayer ceramic capacitor has the above-described structure, the capacitance can be measured by bringing a pair of probes constituting the capacitance measuring device of the present invention into contact with a pair of external electrodes of the multilayer ceramic capacitor.

[0222] It is preferable that the pair of external electrodes is formed on at least one of the four surfaces other than the two end surfaces, straddling the ridge line portion.

[0223] If a pair of external electrodes are also formed across the ridgeline portion on at least one of the four surfaces other than the two end surfaces, the electrostatic capacitance can be measured by bringing a pair of probes constituting the electrostatic capacitance measuring device of the present invention into contact with the portion of a pair of external electrodes formed across the ridgeline portion from the two end surfaces.

[0224] The shape of the multilayer ceramic capacitor may be, for example, a substantially rectangular parallelepiped shape having a length of about 0.6 mm in the longitudinal direction and a length of about 0.3 mm in the width direction and the stacking direction.

[0225] The shape of the multilayer ceramic capacitor may be, for example, a substantially rectangular parallelepiped shape having a length of about 0.4 mm in the longitudinal direction and a length of about 0.2 mm in the width direction and the stacking direction.

[0226] The shape of the multilayer ceramic capacitor may be, for example, a substantially rectangular parallelepiped shape having a length of about 0.2 mm in the longitudinal direction and a length of about 0.1 mm in the width direction and the stacking direction.

[0227] The shape of the multilayer ceramic capacitor may be, for example, a substantially rectangular parallelepiped shape having a length of about 0.1 mm in the longitudinal direction and a length of about 0.05 mm in the width direction and the stacking direction.

[0228] The thickness of a portion of the external electrode formed on a surface other than the two end surfaces is also referred to as a folded-back thickness.

[0229] The folded-back thickness of the external electrode is not particularly limited, but is preferably 10 μm or more and 25 μm or less.

[0230] When the shape of the multilayer ceramic capacitor is a substantially rectangular parallelepiped having a length of about 0.6 mm in the longitudinal direction and about 0.3 mm in the width direction and the stacking direction, the folded thickness is preferably 15 μm to 25 μm.

[0231] When the shape of the multilayer ceramic capacitor is a substantially rectangular parallelepiped having a length of about 0.4 mm in the longitudinal direction and about 0.2 mm in the width direction and the stacking direction, the folded thickness is preferably 10 μm to 20 μm.

[0232] When the shape of the multilayer ceramic capacitor is a substantially rectangular parallelepiped having a length of about 0.2 mm in the longitudinal direction and about 0.1 mm in the width direction and the stacking direction, the folded thickness is preferably 10 μm to 15 μm.

[0233] When the shape of the multilayer ceramic capacitor is a substantially rectangular parallelepiped having a length of about 0.1 mm in the longitudinal direction and about 0.05 mm in the width direction and the stacking direction, the folded thickness is preferably 10 μm to 15 μm.

[0234] The following inventions are disclosed in this specification.

[0235] The present disclosure (1) is an electrostatic capacitance measuring device comprising:

[0236] a pair of probes extending in the long-side direction and arranged to be substantially parallel;

[0237] an electrostatic capacitance measuring device connected to the pair of probes;

[0238] a shielding plate in the shape of a flat plate, arranged such that the first and second main surfaces facing each other extend in a direction parallel to the direction in which the pair of probes extend, and the first and second main surfaces are sandwiched between the pair of probes; and

[0239] Insulating layers are respectively provided on the first main surface and the second main surface of the shielding plate,

[0240] The electrostatic capacitance measuring device is characterized in that

[0241] The shield plate is arranged at all positions overlapping the pair of probes when viewed from a direction in which the pair of probes overlap each other.

[0242] The present disclosure (2) is the electrostatic capacitance measuring device according to the present disclosure (1), further comprising a probe driving mechanism for moving the tips of the pair of probes in the longitudinal direction.

[0243] The present disclosure (3) is an electrostatic capacitance measuring device according to the present disclosure (1) or (2), wherein the diameter of each probe constituting the pair of probes is greater than or equal to 30 μm and less than or equal to 260 μm, and the tip diameter is greater than or equal to 1 μm and less than or equal to 10 μm.

[0244] The present disclosure (4) is a capacitance measuring method, which comprises measuring the capacitance of a multilayer ceramic capacitor using the capacitance measuring apparatus described in any one of the present disclosures (1) to (3).

[0245] The electrostatic capacitance measuring method is characterized in that:

[0246] The multilayer ceramic capacitor has a substantially rectangular main body and external electrodes, wherein the main body has two main surfaces facing each other in a stacking direction, two end surfaces facing each other in a long side direction orthogonal to the stacking direction, and two side surfaces facing each other in a width direction orthogonal to the stacking direction and the long side direction, and the external electrodes are formed on the two end surfaces, respectively.

[0247] The electrostatic capacitance is measured by the pair of probes being in contact with the pair of external electrodes.

[0248] The present disclosure (5) is a capacitance measuring method according to the present disclosure (4), wherein the pair of external electrodes are formed on at least one of the four surfaces other than the two end surfaces across the ridgeline portion.

[0249] The capacitance is measured by bringing the pair of probes into contact with portions of the pair of external electrodes formed from the two end surfaces across the ridge line.

[0250] The present disclosure (6) is a capacitance measuring method according to the present disclosure (5), wherein, in a state where the pair of probes are in contact with the pair of external electrodes, the shielding plate protrudes further toward the multilayer ceramic capacitor than the front ends of the pair of probes,

[0251] The distance between the front end of the shielding plate and the main body when the pair of probes are brought into contact with each other is equal to or less than the thickness of the external electrode.

[0252] [Example]

[0253] Hereinafter, embodiments that more specifically disclose the present invention will be shown, but the present invention is not limited to these embodiments.

[0254] (Example 1)

[0255] For a multilayer ceramic capacitor whose capacitance has been accurately determined, a pair of probes and a shield plate are used. Figure 3 The capacitance was measured using the capacitance measuring device in the state shown (that is, the state in which the tips of the pair of probes and the tip of the shielding plate were flush with each other).

[0256] Since the measured value is measured as a value including stray capacitance between probes, the stray capacitance between probes is calculated by (measured value) - (accurate electrostatic capacitance of the multilayer ceramic capacitor). The stray capacitance is calculated by taking the average value of the 10 measurement results as the measured value, and the stray capacitance is 0.2 fF.

[0257] Furthermore, as the multilayer ceramic capacitor, a multilayer ceramic capacitor having a lengthwise dimension of 0.6 mm and a widthwise dimension and a stacking direction of 0.3 mm was used.

[0258] A stacked ceramic capacitor has a body with a roughly rectangular shape and an external electrode, the body having two end faces (a first end face and a second end face) opposing each other in the long side direction, two main faces (a first main face and a second main face) opposing each other in a stacking direction perpendicular to the long side direction, and two side faces (a first side face and a second side face) perpendicular to the long side direction and the stacking direction, the external electrode respectively covering the first end face and the second end face of the body.

[0259] The external electrode comprises a first external electrode formed on the first principal surface, the second principal surface, the first side surface and a part of the second side surface from the first end surface of the main body across the ridge line portion, and a second external electrode formed on the first principal surface, the second principal surface, the first side surface and a part of the second side surface from the second end surface of the main body across the ridge line portion, and the folded back thickness of the external electrodes formed on the first principal surface, the second principal surface, the first side surface and the second side surface is 30 μm.

[0260] (Example 2)

[0261] The capacitance of the multilayer ceramic capacitor was measured by the same procedure as in Example 1 except that the position of the shield plate in the Y direction was adjusted so that the tip of the shield plate protruded 20 μm beyond the tips of the pair of probes, and the stray capacitance between the probes was obtained.

[0262] The value of stray capacitance is 0.05fF.

[0263] (Comparative Example 1)

[0264] The capacitance of the multilayer ceramic capacitor was measured by the same procedure as in Example 1 except that the positions of the pair of probes in the Y direction were adjusted and no shielding plate was provided between the pair of probes, thereby obtaining the stray capacitance between the probes.

[0265] The value of the stray capacitance is 8.0fF.

[0266] The results of Example 1 and Comparative Example 1 show that the stray capacitance generated at the tip of the probe can be significantly reduced by using the capacitance measuring device of the present invention. It is thus confirmed that the capacitance of the object to be measured can be measured with high accuracy by using the capacitance measuring device of the present invention.

[0267] From the results of Example 1 and Example 2, it was confirmed that the stray capacitance can be further reduced by making the end surface of the shield plate protrude further than the front ends of the pair of probes.

Claims

1. An electrostatic capacitance measuring device, comprising: a pair of probes extending in the long-side direction and arranged to be substantially parallel; an electrostatic capacitance measuring device connected to the pair of probes; a shielding plate in the shape of a flat plate, arranged such that the first and second main surfaces facing each other extend in a direction parallel to the direction in which the pair of probes extend, and the first and second main surfaces are sandwiched between the pair of probes; and Insulating layers are respectively provided on the first main surface and the second main surface of the shielding plate, The electrostatic capacitance measuring device is characterized in that The shield plate is arranged at all positions overlapping the pair of probes when viewed from a direction in which the pair of probes overlap each other.

2. The electrostatic capacitance measuring device according to claim 1, wherein The capacitance measuring device further includes a probe driving mechanism that moves the tips of the pair of probes in the longitudinal direction.

3. The electrostatic capacitance measuring device according to claim 1 or 2, wherein: The diameter of each probe constituting the pair of probes is 30 μm or more and 260 μm or less, and the tip diameter is 1 μm or more and 10 μm or less.

4. A capacitance measuring method, comprising measuring the capacitance of a multilayer ceramic capacitor using the capacitance measuring device according to any one of claims 1 to 3, The electrostatic capacitance measuring method is characterized in that: The multilayer ceramic capacitor has a substantially rectangular main body and external electrodes, wherein the main body has two main surfaces facing each other in a stacking direction, two end surfaces facing each other in a long side direction orthogonal to the stacking direction, and two side surfaces facing each other in a width direction orthogonal to the stacking direction and the long side direction, and the external electrodes are formed on the two end surfaces, respectively. The electrostatic capacitance is measured by the pair of probes being in contact with the pair of external electrodes.

5. The electrostatic capacitance measuring method according to claim 4, wherein: The pair of external electrodes are further formed across the ridgeline portion on at least one of the four surfaces other than the two end surfaces, The capacitance is measured by bringing the pair of probes into contact with portions of the pair of external electrodes formed from the two end surfaces across the ridge line.

6. The electrostatic capacitance measuring method according to claim 5, wherein: In a state where the pair of probes are in contact with the pair of external electrodes, the shield plate protrudes further toward the multilayer ceramic capacitor than the tips of the pair of probes. The distance between the front end of the shielding plate and the main body when the pair of probes are brought into contact with each other is equal to or less than the thickness of the external electrode.

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