Measuring device, method, program, and recording medium

Abstract

To improve defect measurement of a wiring that has a branch.SOLUTION: A wiring measurement device 1 comprises: a reflected signal measurement unit 11 for measuring a reflected signal y(t) that is reflected to one end Pr as the result of an incident signal having a prescribed waveform being applied to one end (probe) Pr of a wiring 2; a definite value component derivation unit 15 for deriving, for each defect candidate position B4, B5, a definite value component γshortest2*δ(t) that is proportionate to a defect dependent component DDR of the reflected signal y(t) that depends on a defect and has a definite value irrespective of the type of defect; a defect dependent component derivation unit 13 for subtracting a defect independent component DIR of the reflected signal that is independent of defect from the measurement result of the reflected signal y(t) so as to derive the defect dependent component DDR for each defect candidate position B4, B5; and a defect position specification unit 17 for specifying that a defect candidate position is the position of a defect when the difference in time at which the definite value component and the defect dependent component DDR assume an extreme value.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to measuring defects in wiring by TDR (Time Domain Reflectometry). [Background technology]

[0002] Measurement of wiring defects using TDR has been known for some time (see Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-192239 A [Patent Document 2] JP 2015-118045 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the wiring to be measured has branches (especially multiple branches), defect independent reflection (DIR) cannot be ignored, which complicates the TDR waveform and makes it difficult to measure defects.

[0005] Therefore, an object of the present invention is to measure defects in wiring having branches. [Means for solving the problem]

[0006] The measuring device according to the present invention is a measuring device for measuring a wiring having a defect candidate position which is a position where a defect may occur, and is configured to include: a reflected signal measurement unit that measures a reflected signal reflected from one end of the wiring as a result of an incident signal having a predetermined waveform being applied to the one end; a constant value component derivation unit that derives, for each of the defect candidate positions, a constant value component which is proportional to a defect dependent component of the reflected signal which is dependent on the defect and has a constant value regardless of the type of the defect; a defect dependent component derivation unit that subtracts a defect independent component of the reflected signal which is independent of the defect from the measurement results of the reflected signal to derive the defect dependent component for each of the defect candidate positions; and a defect position identification unit that identifies the defect candidate position as the position of the defect when the difference in time at which the constant value component and the defect dependent component take extreme values ​​is within a predetermined range.

[0007] The measuring device configured as described above measures a wiring having a defect candidate position which is a position where a defect may occur. A reflected signal measuring unit measures a reflected signal reflected at one end of the wiring as a result of an incident signal having a predetermined waveform being applied to the one end. A constant value component deriving unit derives a constant value component for each defect candidate position which is proportional to a defect dependent component of the reflected signal which is dependent on the defect and has a constant value regardless of the type of the defect. A defect dependent component deriving unit subtracts a defect independent component of the reflected signal which is independent of the defect from the measurement result of the reflected signal to derive the defect dependent component for each defect candidate position. A defect position identifying unit identifies the defect candidate position as the position of the defect when the difference in time at which the constant value component and the defect dependent component take extreme values ​​is within a predetermined range.

[0008] In addition, the measuring apparatus according to the present invention may be provided with a defect type identification unit that identifies the type of the defect based on the ratio of the extreme value of the defect dependent component to the extreme value of the constant value component at the position of the identified defect.

[0009] In addition, in the measuring device of the present invention, the defect type identification unit may identify the type of the defect as an open when the ratio is 1, a resistive open when the ratio is greater than 0 and less than 1, a resistive short when the ratio is less than 0 and greater than -1, and a short when the ratio is -1.

[0010] In addition, in the measuring device of the present invention, the wiring may have a transmission line, the defect candidate location may be located at an end of the transmission line, and the characteristic impedance, length, and electromagnetic wave propagation speed of the transmission line may be known.

[0011] In the measurement device according to the present invention, the reflected signal may be a sum of the defect dependent component and the defect independent component.

[0012] In the measuring device according to the present invention, the incident signal may be a pulse.

[0013] The measurement device according to the present invention calculates the reflected signal when it is assumed that an open exists at the defect candidate position as y open (t), and the reflected signal when it is assumed that a short exists at the defect candidate position is y short (t) (where t is time), the constant value component is y open (t) and y short It may be derived based on (t).

[0014] In addition, in the measurement device according to the present invention, the constant value component is (y open (t)-y short (t) / 2.

[0015] The measurement device according to the present invention calculates the reflected signal when it is assumed that an open exists at the defect candidate position as y open (t), and the reflected signal when it is assumed that a short exists at the defect candidate position is y short (t) (where t is time), the defect independent component is yopen (t) and y short It may be derived based on (t).

[0016] In addition, in the measurement device according to the present invention, the defect independent component is (y open (t)+y short (t) / 2.

[0017] In addition, the measuring device of the present invention may be configured to determine whether the difference in time at which the constant value component and the defect dependent component take extreme values ​​is within a specified range only for the defect candidate positions outside the time range in which the ideal reflection signal, which is the reflection signal when it is assumed that no defects exist at any of the defect candidate positions, and the measurement result of the reflection signal match.

[0018] The present invention is a measurement method for measuring a wiring having a defect candidate position which is a position where a defect may occur, the measurement method comprising: a reflected signal measurement step of measuring a reflected signal reflected from one end of the wiring as a result of an incident signal having a predetermined waveform being applied to the one end; a constant value component derivation step of deriving, for each of the defect candidate positions, a constant value component which is proportional to a defect dependent component of the reflected signal which is dependent on the defect and has a constant value regardless of the type of the defect; a defect dependent component derivation step of subtracting a defect independent component of the reflected signal which is independent of the defect from the measurement results of the reflected signal to derive the defect dependent component for each of the defect candidate positions; and a defect position identification step of identifying the defect candidate position as the position of the defect when the difference in time at which the constant value component and the defect dependent component take extreme values ​​is within a predetermined range.

[0019] The present invention is a program for causing a computer to execute a measurement process for measuring a wiring having a defect candidate position which is a position where a defect may occur, the measurement process comprising: a reflected signal measurement step for measuring a reflected signal reflected from one end of the wiring as a result of an incident signal having a predetermined waveform being applied to the one end of the wiring; a constant value component derivation step for deriving, for each of the defect candidate positions, a constant value component which is proportional to a defect dependent component of the reflected signal which is dependent on the defect and has a constant value regardless of the type of the defect; a defect dependent component derivation step for subtracting a defect independent component of the reflected signal which is independent of the defect from the measurement results of the reflected signal to derive the defect dependent component for each of the defect candidate positions; and a defect position identification step for identifying the defect candidate position as the position of the defect when the difference in time at which the constant value component and the defect dependent component take extreme values ​​is within a predetermined range.

[0020] The present invention is a computer-readable recording medium having recorded thereon a program for causing a computer to execute a measurement process for measuring a wiring having a defect candidate position which is a position where a defect may occur, the measurement process including: a reflected signal measurement step for measuring a reflected signal reflected from one end of the wiring as a result of an incident signal having a predetermined waveform being applied to the one end of the wiring; a constant value component derivation step for deriving, for each of the defect candidate positions, a constant value component which is proportional to a defect dependent component of the reflected signal which is dependent on the defect and has a constant value regardless of the type of the defect; a defect dependent component derivation step for subtracting a defect independent component of the reflected signal which is independent of the defect from the measurement results of the reflected signal to derive the defect dependent component for each of the defect candidate positions; and a defect position identification step for identifying the defect candidate position as the position of the defect when the difference in time at which the constant value component and the defect dependent component take extreme values ​​is within a predetermined range. [Brief description of the drawings]

[0021] [Figure 1] 1 is a functional block diagram showing a configuration of a wiring measurement device 1 according to an embodiment of the present invention. [Diagram 2]1 is a circuit diagram showing a configuration of a wiring 2' that is an example of a measurement target of a wiring measuring apparatus 1 according to an embodiment of the present invention. [Diagram 3] 4 is a circuit diagram showing a configuration of a wiring 2 which is another example of an object to be measured by the wiring measuring apparatus 1 according to the embodiment of the present invention. FIG. [Figure 4] 13 is a graph showing constant value components C(B1), C(B2), C(B3), C(B4), and C(B5). [Diagram 5] 13 is a graph showing the reflected signal (measurement result) y(t), the ideal reflected signal, C(B4), and C(B5). [Figure 6] 13 is a graph showing constant components C(B4), C(B5) and defect dependent components DDR(B4), DDR(B5). [Figure 7] 13 is a graph showing another example of the reflected signal (measurement result) y(t), the ideal reflected signal, C(B4), and C(B5). [Figure 8] 13 is a graph showing another example of constant-value components C(B4), C(B5) and defect-dependent components DDR(B4), DDR(B5). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0023] Fig. 1 is a functional block diagram showing the configuration of a wiring measuring apparatus 1 according to an embodiment of the present invention. Fig. 2 is a circuit diagram showing the configuration of a wiring 2' which is an example of a measurement target of the wiring measuring apparatus 1 according to the embodiment of the present invention.

[0024] The wiring measurement device 1 according to the embodiment of the present invention includes a reflected signal measurement unit 11, a defect dependent component deriving unit 13, a virtual reflected signal recording unit 14, a constant value component deriving unit 15, a defect position identifying unit 17, and a defect type identifying unit 19.

[0025] 2, a wiring 2' to be measured by the wiring measurement apparatus 1 has a probe Pr at one end. The wiring 2' includes k (where k is an integer equal to or greater than 2) transmission lines 101-1, 101-2, ..., 101-k, k transmission lines 102-1, 102-2, ..., 102-k, and a load Z L The wiring measuring device 1 measures the wiring 2'.

[0026] The wiring 2′ has a defect candidate position, which is a position where a defect may occur. In FIG. L are defect candidate locations. However, defects can be any of the following four types: open, resistive open, resistive short, or short.

[0027] The probe Pr is connected to the load Z through the transmission lines 101-1, 101-2, ... and 101-k. L The transmission lines 101-1, 101-2, ..., and 101-k are connected in series. The propagation coefficients of the transmission lines 101-1, 101-2, ..., and 101-k are P1, P2, ..., P k The transfer coefficients of the wiring between the transmission lines 101-1, 101-2, ..., 101-k and the components to the left of them (probe Pr, transmission lines 101-1, ..., transmission line 101-(k-1)) are T1, T2, ..., T k It is.

[0028] The transmission lines 102-1, 102-2, ..., 102-k are connected to the ends of the transmission lines 101-1, 101-2, ..., 101-k on the probe Pr side (left side in FIG. 2). L The transfer coefficients of the inputs from the left components (probe Pr, transmission lines 101-1, ..., 101-(k-1), 101-k) to k , Γ k+1 The transfer coefficients of the inputs from the members (transmission lines 101-1, 101-2, ..., 101-k) on the right side to the transmission lines 102-1, 102-2, ..., 102-k are Γ1', Γ2', ..., Γ k ' is.

[0029] An incident signal having a predetermined waveform (e.g., a pulse) is applied to one end (probe Pr) of the wiring 2'. As a result, a reflected signal y(t) reflected by the probe Pr is measured by the reflected signal measuring unit 11, where t is time.

[0030] Here, γ shortest (=T1 P1 T2 P2 … T k P k ) is defined as the following equation (1).

[0031]

number

[0032]

number

[0033] Here, the first term of equation (2) (Γ k+1 Gamma shortest 2*δ(t)) is called the defect dependent reflection (DDR) component of the reflected signal y(t) that is dependent on the defect. k+1 fluctuates, but γ shortest 2 *δ(t) (called the “constant component”) is proportional to the defect-dependent component (DDR) and is independent of the type of defect (i.e., Γ k+1 The second term in equation (2), g(t)*δ(t), has a constant value regardless of the value of . The second term in equation (2), g(t)*δ(t), is called the defect independent reflection (DIR), which is independent of defects. Therefore, the reflected signal y(t) can be considered as the sum of the defect dependent reflection (DDR) and the defect independent reflection (DIR).

[0034] In addition, the defect candidate position (load Z L ) if we assume that there is an open in (Γ k+1 = 1) reflected signal y(t) is expressed as a virtual reflected signal y open (t). Furthermore, the defect candidate position (load Z L If we assume that there is a short circuit at (Γ k+1 =-1) reflected signal y(t) is expressed as a virtual reflected signal y short Let (t).

[0035] Then, the virtual reflected signal y open (t) and y short (t) is expressed by the following equations (3) and (4). Note that the virtual reflected signal y open (t) and y short (t) is the defect candidate position (load Z in Fig. 2). L ) (B1, B2, B3, B4 and B5 in FIG. 3).

[0036]

number

[0037] Then, the constant component γ shortest 2 *δ(t) is expressed as in equation (5) below, and the defect independent component g(t)*δ(t) (DIR) is expressed as in equation (6) below.

[0038]

number

[0039] The defect dependent component deriving unit 13 calculates the defect independent component as y open (t) and y short Specifically, the defect dependent component derivation unit 13 derives the defect independent component as shown in equation (6).

[0040] The defect dependent component deriving unit 13 further subtracts the defect independent component (DIR) (g(t)*δ(t)) from the measurement result of the reflected signal y(t) to obtain the defect dependent component (DDR) (Γ k+1 Gamma shortest 2 *δ(t)) is calculated by dividing the defect candidate position (load Z L ) (B1, B2, B3, B4, and B5 in FIG. 3) (see equation (2)).

[0041] The defect position identifying unit 17 detects the constant value component γ shortest 2 *δ(t) and the defect dependent component (DDR) (Γ k+1 Gamma shortest 2 A defect candidate position where the difference in the time when the maximum value of the function δ(t)) is taken is within a predetermined range is identified as the position of a defect.

[0042] Since the constant component is proportional to the defect dependent component, if a defect exists at the defect candidate position, the times at which the constant component and the defect dependent component take their extreme values ​​should essentially match (although there may be some deviation due to measurement errors). Therefore, if the difference between the times at which the constant component and the defect dependent component take their extreme values ​​is within a predetermined range (for example, see the graphs relating to B5 in Figures 6 and 8), it is deemed that a defect exists at the defect candidate position.

[0043] The defect type specifying unit 19 calculates the ratio of the extreme value of the defect dependent component to the extreme value of the constant component at the position of the defect specified by the defect position specifying unit 17 (=Γ k+1 ) to identify the type of defect.

[0044] Equation (2) is expressed as Γ k+1 When we solve this, we get the following equation (7). shortest 2 *Substituting equation (5) into δ(t), we obtain equation (8).

[0045]

number

[0046] The defect type identifying unit 19 calculates the values ​​of the formulas (7) and (8) by calculating the ratio of the extreme value of the defect dependent component to the extreme value of the constant component at the position of the defect identified by the defect position identifying unit 17 (=Γ k+1 The defect type identifying unit 19 further derives the defect type as follows: Gamma k+1 If is 1, open the defect type Gamma k+1 If is greater than 0 and less than 1, the defect type is resistive open (see Figure 8); Gamma k+1If is less than 0 and greater than -1, the defect type is resistive short (see Figure 6); Gamma k+1 If is -1, identify the defect type as a short.

[0047] Next, the operation of the embodiment of the present invention will be described.

[0048] FIG. 3 is a circuit diagram showing a configuration of a wiring 2 which is another example of an object to be measured by the wiring measuring apparatus 1 according to the embodiment of the present invention.

[0049] The wiring 2 has transmission lines Tr1, Tr2, Br1, Br2, Br3, Br4, and Br5. The characteristic impedance, length, and electromagnetic wave propagation speed of the transmission lines Tr1, Tr2, Br1, Br2, Br3, Br4, and Br5 are known. The wiring 2 has a probe Pr at one end.

[0050] A probe Pr is connected to the left end of the transmission line Tr1. Transmission lines Tr2, Br1, Br2, and Br3 are connected to the right end of the transmission line Tr1.

[0051] At the end of transmission line Br1 (the end not connected to transmission line Tr1), defect candidate location B1 is located, and device D1 is connected to it. At the end of transmission line Br2 (the end not connected to transmission line Tr1), defect candidate location B2 is located, and device D2 is connected to it. At the end of transmission line Br3 (the end not connected to transmission line Tr1), defect candidate location B3 is located, and device D3 is connected to it.

[0052] The end of the transmission line Tr2 (the end not connected to the transmission line Tr1) is connected to the transmission lines Br4 and Br5.

[0053] At the end of the transmission line Br4 (the end not connected to the transmission line Tr2), a defect candidate location B4 is located, and a device D4 is connected to it. At the end of the transmission line Br5 (the end not connected to the transmission line Tr2), a defect candidate location B5 is located, and a device D5 is connected to it.

[0054] The virtual reflection signal recording unit 14 previously stores the virtual reflection signal y open (t) and y short (t) is recorded. Based on the contents recorded in the virtual reflected signal recording unit 14, the constant value component derivation unit 15 derives the constant value component for each defect candidate position (B1, B2, B3, B4, and B5 in FIG. 3). Here, the constant value component for the defect candidate position B1 is called C(B1), the constant value component for the defect candidate position B2 is called C(B2), the constant value component for the defect candidate position B3 is called C(B3), the constant value component for the defect candidate position B4 is called C(B4), and the constant value component for the defect candidate position B5 is called C(B5).

[0055] For example, the constant value component C(B1) for the defect candidate position B1 is a virtual reflected signal y open (t) and the virtual reflected signal y short (t) can be calculated by substituting into equation (5).

[0056] Figure 4 is a graph showing constant value components C(B1), C(B2), C(B3), C(B4), and C(B5). The constant value components C(B1), C(B2), C(B3), C(B4), and C(B5) each have a different peak time. The constant value components C(B1), C(B2), and C(B3) reach their peaks at times less than 170 ps, ​​while the constant value components C(B4) and C(B5) reach their peaks at times greater than 170 ps.

[0057] An incident signal is applied to one end (probe Pr) of the wiring 2 , and a reflected signal y(t) reflected by the probe Pr is measured by a reflected signal measuring unit 11 .

[0058] 5 is a graph showing the reflected signal (measurement result) y(t), the ideal reflected signal, C(B4), and C(B5). Note that the ideal reflected signal is a reflected signal that would occur if no defects existed at any of the defect candidate positions B1 to B5.

[0059] Since the reflected signal (measurement result) y(t) and the ideal reflected signal match up to a time of 170 ps, ​​it is found that there are no defects at defect candidate positions B1, B2, and B3, which have peak times less than 170 ps. Therefore, only for defect candidate positions B4 and B5 outside the time range (170 ps or more) where the ideal reflected signal and the measurement result y(t) of the reflected signal match, it is determined whether the difference in time at which the constant value components C(B4), C(B5) and the defect dependent components DDR(B4), DDR(B5) reach their extreme values ​​is within a predetermined range.

[0060] Since the reflected signal (measurement result) y(t) does not match either the constant value component C(B4) or the constant value component C(B5), it is unclear from FIG. 5 whether the defect is located at the defect candidate position B4 or B5.

[0061] Therefore, the defect dependent component deriving unit 13 calculates the defect independent component as follows: open (t) and y short The defect dependent component deriving unit 13 further subtracts the defect independent component (DIR) (g(t)*δ(t)) from the measurement result of the reflected signal y(t) to derive the defect dependent component (DDR) (Γ k+1 Gamma shortest 2 *δ(t)) is derived for each defect candidate position (B4, B5) (see equation (2)).

[0062] FIG. 6 is a graph showing the constant components C(B4), C(B5) and the defect dependent components DDR(B4), DDR(B5).

[0063] The defect position identifying unit 17 identifies, for each defect candidate position, a defect candidate position where the difference in time at which the constant value components C(B4), C(B5) and the defect dependent components DDR(B4), DDR(B5) take extreme values ​​is within a predetermined range, as the position of a defect. Note that the predetermined range is set to 0.

[0064] The time when the constant component C (B4) takes an extreme value is 200 ps, ​​and the time when the defect-dependent component DDR (B4) takes an extreme value is 194 ps. Since the difference in the times when the extreme values ​​are taken is 6 ps > 0, it can be seen that there is no defect at the defect candidate position B4.

[0065] The time when the constant component C (B5) takes an extreme value is 210 ps, ​​and the time when the defect-dependent component DDR (B5) takes an extreme value is also 210 ps. Therefore, the difference in the time when the extreme values ​​are taken is 0. Therefore, it is found that there is a defect at the defect candidate position B5.

[0066] The defect type identification unit 19 identifies the type of defect as a resistive short based on the ratio (=-0.67) of the extreme value (-0.4V) of the defect dependent component DDR(B5) to the extreme value (0.6V) of the constant value component C(B5) at the position of the defect identified by the defect position identification unit 17 (defect candidate position B5).

[0067] Fig. 7 is a graph showing another example of the reflected signal (measurement result) y(t), the ideal reflected signal, C(B4), and C(B5). Fig. 8 is a graph showing another example of the constant value components C(B4), C(B5), and the defect dependent components DDR(B4), DDR(B5).

[0068] The defect position identifying unit 17 identifies, for each defect candidate position, a defect candidate position where the difference in time at which the constant value components C(B4), C(B5) and the defect dependent components DDR(B4), DDR(B5) take extreme values ​​is within a predetermined range, as the position of a defect. Note that the predetermined range is set to 0.

[0069] The time when the constant component C (B4) takes an extreme value is 200 ps, ​​and the time when the defect-dependent component DDR (B4) takes an extreme value is 195 ps. Since the difference in the time when the extreme values ​​are taken is 5 ps > 0, it can be seen that there is no defect at the defect candidate position B4.

[0070] The time when the constant component C (B5) takes an extreme value is 210 ps, ​​and the time when the defect-dependent component DDR (B5) takes an extreme value is also 210 ps. Therefore, the difference in the time when the extreme values ​​are taken is 0. Therefore, it is found that there is a defect at the defect candidate position B5.

[0071] The defect type identification unit 19 identifies the type of defect as a resistive open based on the ratio (=0.65) of the extreme value (0.39 V) of the defect dependent component DDR (B5) to the extreme value (0.6 V) of the constant value component C (B5) at the position of the defect identified by the defect position identification unit 17 (defect candidate position B5).

[0072] According to an embodiment of the present invention, it is possible to measure defects in wiring having branches.

[0073] The above embodiment can be realized as follows: A computer equipped with a CPU, a hard disk, and a media (USB memory, CD-ROM, etc.) reading device reads a medium on which a program for implementing each of the above sections, such as the reflected signal measuring section 11, the defect dependent component deriving section 13, the virtual reflected signal recording section 14, the constant value component deriving section 15, the defect position identifying section 17, and the defect type identifying section 19, is recorded, and the program is installed on the hard disk. The above functions can also be realized in this manner. [Explanation of symbols]

[0074] 1 Wiring measuring device 11 Reflection signal measurement section 13 Defect dependent component derivation part 14 Virtual reflection signal recording section 15 Constant value component derivation part 17 Defect location identification section 19 Defect type identification section 2' Wiring Pr probe 101-1, 101-2, …, 101-k transmission lines 102-1, 102-2, …, 102-k transmission lines Z L load P1, P2, …, P k Propagation coefficient T1, T2, …, T k Transfer coefficient Γ1, Γ2, …, Γ k , Γ k+1 Transfer coefficient Γ1', Γ2', …, Γ k 'Transmission coefficient 2 Wiring Tr1, Tr2, Br1, Br2, Br3, Br4, Br5 transmission lines D1, D2, D3, D4, D5 Devices B1, B2, B3, B4, B5 Defect candidate positions δ(t) Incident signal y(t) reflected signal Gamma k+1 Gamma shortest 2 *δ(t) Defect Dependent Reflection (DDR) g(t)*δ(t) Defect Independent Reflection (DIR) y open (t), y short (t) Virtual reflected signal Gamma shortest 2 *δ(t) constant component C(B1), C(B2), C(B3), C(B4), C(B5) Constant value component DDR(B4), DDR(B5) defect dependent components

Claims

1. A measuring apparatus for measuring a wiring having a defect candidate position which is a position where a defect may occur, comprising: a reflected signal measuring unit that measures a reflected signal reflected at one end of the wiring as a result of an incident signal having a predetermined waveform being applied to the one end of the wiring; a constant value component deriving unit that derives a constant value component, which is proportional to a defect dependent component of the reflected signal that is dependent on the defect and has a constant value regardless of the type of the defect, for each of the defect candidate positions; a defect dependent component deriving unit that subtracts a defect independent component that is independent of the defect from the measurement result of the reflected signal, and derives the defect dependent component for each of the defect candidate positions; a defect position identifying unit that identifies the defect candidate position as the position of the defect when a difference between the time when the constant value component and the defect dependent component take an extreme value is within a predetermined range; A measuring device comprising:

2. 2. The measuring device according to claim 1, A measurement apparatus comprising a defect type identification unit that identifies a type of the defect based on a ratio of an extreme value of the defect dependent component to an extreme value of the constant value component at a position of the identified defect.

3. The measuring device according to claim 2, The defect type identification unit identifies the type of the defect as follows: If the ratio is 1, open If the ratio is greater than 0 and less than 1, it is a resistive open; If the ratio is less than 0 and greater than -1, it is a resistive short. If the ratio is -1, it is a short. A measuring device that identifies the

4. 2. The measuring device according to claim 1, the wiring includes a transmission line, the defect candidate location is located at an end of the transmission line, The characteristic impedance, length and electromagnetic wave propagation velocity of the transmission line are known; Measuring equipment.

5. 2. The measuring device according to claim 1, the reflected signal is a sum of the defect dependent component and the defect independent component; Measuring equipment.

6. 2. The measuring device according to claim 1, A measurement device in which the incident signal is a pulse.

7. 2. The measuring device according to claim 1, The reflected signal when it is assumed that an open exists at the defect candidate position is expressed as y open (t) The reflected signal when it is assumed that a short exists at the defect candidate position is expressed as y short (t) (where t is time), The constant value component is y open (t) and y short (t) is derived based on Measuring equipment.

8. The measuring device according to claim 7, The constant value component is (y open (t)-y short (t) / 2, Measuring equipment.

9. 2. The measuring device according to claim 1, The reflected signal when it is assumed that an open exists at the defect candidate position is expressed as y open (t) The reflected signal when it is assumed that a short exists at the defect candidate position is expressed as y short (t) (where t is time), The defect independent component is y open (t) and y short (t) is derived based on Measuring equipment.

10. The measuring device according to claim 9, The defect independent components are (y open (t) + y short (t) / 2, Measuring equipment.

11. 2. The measuring device according to claim 1, A measuring device that determines whether the difference in time at which the constant value component and the defect dependent component take extreme values ​​is within a specified range only for the defect candidate positions outside the time range in which the ideal reflection signal, which is the reflection signal when it is assumed that no defects exist at any of the defect candidate positions, and the measurement result of the reflection signal agree.

12. A method for measuring a wiring having a defect candidate position which is a position where a defect may occur, comprising the steps of: a reflected signal measuring step of measuring a reflected signal reflected at one end of the wiring as a result of an incident signal having a predetermined waveform being applied to the one end of the wiring; a constant value component deriving step of deriving a constant value component, which is proportional to a defect dependent component of the reflected signal that is dependent on the defect and has a constant value regardless of the type of the defect, for each of the defect candidate positions; a defect dependent component deriving step of subtracting a defect independent component of the reflected signal, which is independent of the defect, from the measurement result of the reflected signal to derive the defect dependent component for each of the defect candidate positions; a defect location identifying step of identifying the defect candidate location as the location of the defect when a difference between the times when the constant value component and the defect dependent component take an extreme value is within a predetermined range; A measurement method comprising:

13. A program for causing a computer to execute a measurement process for measuring a wiring having a defect candidate position which is a position where a defect may occur, The measurement process includes: a reflected signal measuring step of measuring a reflected signal reflected at one end of the wiring as a result of an incident signal having a predetermined waveform being applied to the one end of the wiring; a constant value component deriving step of deriving a constant value component, which is proportional to a defect dependent component of the reflected signal that is dependent on the defect and has a constant value regardless of the type of the defect, for each of the defect candidate positions; a defect dependent component deriving step of subtracting a defect independent component of the reflected signal, which is independent of the defect, from the measurement result of the reflected signal to derive the defect dependent component for each of the defect candidate positions; a defect location identifying step of identifying the defect candidate location as the location of the defect when a difference between the times when the constant value component and the defect dependent component take an extreme value is within a predetermined range; A program with.

14. A computer-readable recording medium having a program recorded thereon for causing a computer to execute a measurement process for measuring wiring having a defect candidate position which is a position where a defect may occur, The measurement process includes: a reflected signal measuring step of measuring a reflected signal reflected at one end of the wiring as a result of an incident signal having a predetermined waveform being applied to the one end of the wiring; a constant value component deriving step of deriving a constant value component, which is proportional to a defect dependent component of the reflected signal that is dependent on the defect and has a constant value regardless of the type of the defect, for each of the defect candidate positions; a defect dependent component deriving step of subtracting a defect independent component of the reflected signal, which is independent of the defect, from the measurement result of the reflected signal to derive the defect dependent component for each of the defect candidate positions; a defect location identifying step of identifying the defect candidate location as the location of the defect when a difference between the times when the constant value component and the defect dependent component take an extreme value is within a predetermined range; A recording medium comprising:

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