Inspection apparatus and inspection method

Abstract

Provided is an inspection device and an inspection method that easily correct a variation in electrostatic capacitance caused by a manufacturing variation in a substrate. The substrate inspection device is an inspection device that inspects a plurality of substrates on which wiring and reference wiring are formed, and includes: a measurement unit that measures electrostatic capacitance of the wiring and the reference wiring of each substrate as a measurement capacitance; an average capacitance calculation unit that calculates an average value of the measurement capacitance measured from the reference wiring that is designed to be the same wiring as the average capacitance; and a capacitance correction unit that, in a case where one of the plurality of substrates is taken as a target substrate, calculates a correction value of the measurement capacitance of a target wiring that is an inspection target of the target substrate, that is, a correction capacitance, and calculates the correction capacitance by multiplying a ratio of the average capacitance of the wiring of the target substrate to the measurement capacitance by the measurement capacitance of the target wiring.

Description

Technical Field

[0001] This invention relates to an inspection apparatus and method for inspecting substrates. Background Technology

[0002] Previously, there was a known method for inspecting circuit boards, which measures the electrostatic capacitance between a plurality of conductor patterns in the circuit board to be measured and a reference electrode, and inspects the circuit board based on the measured electrostatic capacitance between the reference electrodes (for example, see Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2003-14807 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Furthermore, the electrostatic capacitance of the wiring will vary depending on factors such as the area of ​​the wiring facing each other. Therefore, if the width of the wiring or the thickness of the insulation layer deviates due to manufacturing variations in the substrate, the electrostatic capacitance of the wiring will also deviate.

[0008] The purpose of this invention is to provide an inspection device and inspection method that can easily correct deviations in electrostatic capacitance caused by manufacturing deviations of the substrate.

[0009] Technical means to solve the problem

[0010] An inspection apparatus according to an example of the present invention inspects multiple substrates having wirings that are designed to be identical. The inspection apparatus includes: a measurement unit that measures the electrostatic capacitance of the wirings on each substrate as a measurement capacitance; an average capacitance calculation unit that calculates the average value of the measurement capacitances measured from the wirings designed to be identical as an average capacitance; and a capacitance correction unit that, when one of the multiple substrates is selected as a target substrate, calculates a correction value, i.e., a correction capacitance, for the measurement capacitance of the target wiring that is the object of inspection on the target substrate. The capacitance correction unit calculates the correction capacitance by multiplying the ratio of the average capacitance of the wirings on the target substrate to the measurement capacitance by the measurement capacitance of the target wiring.

[0011] In addition, one example of the inspection method of the present invention inspects multiple substrates having wirings that are designed to be identical. The inspection method includes: a measurement step, measuring the electrostatic capacitance of the wirings of each substrate as a measurement capacitance; an average capacitance calculation step, calculating the average value of the measurement capacitances measured from the wirings designed to be identical as an average capacitance; and a capacitance correction step, in the case of taking one of the multiple substrates as a target substrate, calculating a correction value, i.e., a correction capacitance, of the measurement capacitance of the target wiring that is the object of inspection of the target substrate. The capacitance correction step calculates the correction capacitance by multiplying the ratio of the average capacitance of the wirings of the target substrate to the measurement capacitance by the measurement capacitance of the target wiring.

[0012] The effects of the invention

[0013] The inspection device and method of this structure can easily correct deviations in electrostatic capacitance caused by manufacturing deviations of the substrate. Attached Figure Description

[0014] Figure 1 This is a conceptual diagram that schematically illustrates the structure of a substrate inspection apparatus using an inspection method according to an embodiment of the present invention.

[0015] Figure 2 This is an explanatory diagram showing an example of panel 100.

[0016] Figure 3 This is a top view showing an example of substrate A.

[0017] Figure 4 This is an explanatory diagram showing an example of the substrate An and an example of the electrical structure of the inspection section 3.

[0018] Figure 5 This is a flowchart representing steps S1 to S11.

[0019] Figure 6 This is a flowchart representing steps S21 to S30.

[0020] Figure 7 This is a flowchart representing steps S41 to S43.

[0021] Figure 8 This is a flowchart representing steps S51 to S58.

[0022] Figure 9 This is a diagram showing an example of the measured capacitance C(P(1,1)) to the measured capacitance C(P(25,5)).

[0023] Figure 10This is a diagram showing an example of the correction capacitor Cc(P(1,1)) to the correction capacitor Cc(P(25,5)).

[0024] Explanation of symbols

[0025] 1: Substrate inspection device

[0026] 2: Control Department

[0027] 3: Inspection Department

[0028] 4: Inspection fixture

[0029] 11: Frame

[0030] 12: Substrate fixing device

[0031] 15: Inspection Department Mobile Mechanism

[0032] 21: Inspection and Control Department

[0033] 22: Measurement Department

[0034] 23: Average Capacitance Calculation Section

[0035] 24: Capacitor Correction Section

[0036] 25: Benchmark Value Calculation Department

[0037] 26: Judgment Department

[0038] 31: Scanner Department

[0039] 32: AC power supply

[0040] 33: Ammeter

[0041] 100: Panel

[0042] 102: Carrier substrate

[0043] 103: Peel-off layer

[0044] A, A1~A25: Substrate

[0045] B: Baseline wiring

[0046] C: Measuring capacitance

[0047] Cav: Average capacitance

[0048] Cc: Correction capacitor

[0049] Cref: Judgment benchmark value

[0050] G: Area pattern

[0051] I: Current

[0052] L1: First floor

[0053] L2: Second layer

[0054] L3: Third Layer

[0055] P: Wiring

[0056] Pr: probe

[0057] Ref: Judgment Ratio

[0058] V: Voltage

[0059] e, g: End

[0060] f: body

[0061] X: Static capacitance Detailed Implementation

[0062] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. Furthermore, structures marked with the same symbols in the various figures represent the same structures, and their descriptions are omitted. Figure 1 The substrate inspection apparatus 1 shown is used to inspect the wiring of substrates A1 to A25 formed on panel 100. Substrate inspection apparatus 1 is an example of an inspection apparatus.

[0063] Figure 1 The substrate inspection apparatus 1 shown includes a frame 11. Inside the frame 11, a substrate fixing device 12, an inspection section 3, a control section 2, and an inspection section moving mechanism 15 are mainly provided to allow the inspection section 3 to move appropriately within the frame 11. The substrate fixing device 12 is configured to fix the panel 100, which is the object of inspection, at a predetermined position.

[0064] The inspection unit 3 is located above the panel 100, which is fixed to the substrate fixing device 12. An inspection fixture 4 is installed in the inspection unit 3 to inspect the substrate A formed on the panel 100. Multiple probes Pr are installed in the inspection fixture 4.

[0065] Figure 2 The panel 100 shown includes substrates A1 to A25. Hereinafter, substrates A1 to A25 will be collectively referred to as substrate A, and when referring to individual substrates, the substrate number n will be marked with the symbol A, such as substrate An. Panel 100 is, for example, a panel for panel level packaging (PLP).

[0066] Substrate A can be, for example, a packaging substrate or film carrier for semiconductor packaging, a printed wiring substrate, a glass epoxy substrate, a flexible substrate, a ceramic multilayer wiring substrate, an electrode plate for displays such as liquid crystal displays or electroluminescent (EL) displays, a transparent conductive plate for touch screens, a semiconductor substrate for semiconductor wafers or semiconductor chips or chip-size packages (CSPs), and other similar substrates. Wiring patterns, pads, lands, solder bumps, vias, and inspection points such as terminals are formed on substrate A.

[0067] On substrates A1 to A25, wiring patterns with identical designs are formed. The number of substrates A included in panel 100 is not limited to 25. For example, substrate A is a substrate formed on a carrier and mounted on the RDL when manufacturing a fan-out package, which is a type of semiconductor chip package, in the first process of the redistribution layer (RDL).

[0068] Reference Figure 3 , Figure 4 The substrate An is a multilayer substrate comprising, for example, a first layer L1, a second layer L2, and a third layer L3. Wirings P(n,1) to P(n,5) numbered 1 to 5 and reference wirings B(n,1) to B(n,3) numbered 1 to 3 are formed on the substrate An. Hereinafter, the wiring with wiring number j in substrate Ai with substrate number i will be referred to as wiring P(i,j), and the reference wiring with wiring number j in substrate Ai with substrate number i will be referred to as reference wiring B(i,j).

[0069] Wiring P(n, 1) to wiring P(n, 5) and reference wiring B(n, 1) to reference wiring B(n, 3) are equivalent to an example of wiring. Hereinafter, wiring P(n, 1) to wiring P(n, 5) will be collectively referred to as wiring Pn, wiring P(1, 1) to wiring P(25, 5) will be collectively referred to as wiring P, reference wiring B(n, 1) to reference wiring B(n, 3) will be collectively referred to as reference wiring Bn, and reference wiring B(1, 1) to reference wiring B(25, 3) will be collectively referred to as reference wiring B.

[0070] Wiring P and reference wiring B each include end e, end g, and body f connecting end e and end g. End e and end g are, for example, through holes or gaskets. Body f extends in a strip shape and constitutes the main part of each wiring.

[0071] The end e of wiring P and reference wiring B is formed in the first layer L1. The end g of wiring P and reference wiring B is formed in the third layer L3. The body f of wiring P(n,1) and reference wiring B(n,1) is formed in the first layer L1. The body f of wiring P(n,2), wiring P(n,3) and reference wiring B(n,2) is formed in the second layer L2. The body f of wiring P(n,4), wiring P(n,5) and reference wiring B(n,3) is formed in the third layer L3.

[0072] exist Figure 3 In the diagram, solid lines represent the portion formed in the first layer L1, dashed lines represent the portion formed in the second layer L2, and dotted lines represent the portion formed in the third layer L3.

[0073] like Figure 4 As shown, on the second layer L2 of substrate An, a planar pattern G(n,1) is formed facing the reference wiring B(n,1) and extending in a planar manner, and a planar pattern G(n,3) is formed facing the reference wiring B(n,3) and extending in a planar manner. On the first layer L1 of substrate An, a planar pattern G(n,2) is formed facing the reference wiring B(n,2) and extending in a planar manner.

[0074] In planar patterns G(n,1) and G(n,3), through-holes exposed in the first layer L1 are connected. By contacting the probe Pr with the through-holes, a conductive connection can be established between the probe Pr and the planar patterns G(n,1) and G(n,3). In practice, the first layer L1 connected to the through-holes must be positioned on the through-holes; therefore, contact with the probe Pr enables a conductive connection. The capacitance of the first layer L1 itself is minimized by making it small.

[0075] Furthermore, the planar patterns G(n,1), G(n,2), and G(n,3) only need to be configured facing the reference wirings B(n,1), B(n,2), and B(n,3) respectively, and the configured layers are not limited to... Figure 4 The example shown.

[0076] Panel 100 is constructed by stacking a carrier substrate 102, a release layer 103, and a substrate A in the aforementioned order. The ends e of each wiring are formed on the first layer L1, and the ends g of each wiring are formed on the third layer L3. However, in panel 100 after substrate A is formed on carrier substrate 102 and before the die is mounted on substrate A, since the carrier is mounted on one side of substrate A (third layer L3), it is impossible to make probes contact both surfaces of substrate A to check the continuity of the wiring.

[0077] Therefore, the substrate inspection apparatus 1 performs wiring inspection by contacting the probe Pr with the end e of the exposed surface (first layer L1) of the substrate A or with the via connected to the surface pattern G(n, 2), or with the surface patterns G(n, 1) and G(n, 3), and measuring the electrostatic capacitance of the wiring. In practice, the first layer L1 connected to the via must be disposed on the via, so contact with it by the probe Pr enables a conductive connection. The capacitance of the first layer L1 itself is minimized by making it small.

[0078] Furthermore, panel 100 is not limited to a substrate formed on a carrier after substrate A is formed and before the chip die is mounted on substrate A.

[0079] Reference Figure 4 The inspection unit 3 includes: multiple probes Pr, a scanner unit 31, an AC power supply 32, and multiple ammeters 33. The scanner unit 31 is connected to each probe Pr, one end of the AC power supply 32, one end of each ammeter 33, and a circuit ground. The other end of the AC power supply 32 and the other end of each ammeter 33 are connected to the circuit ground.

[0080] The scanner unit 31 is a switching circuit constructed using switching elements such as transistors or relay switches. Based on control signals from the control unit 2, the scanner unit 31 connects the AC power supply 32 and each ammeter 33 to an arbitrary probe Pr.

[0081] The AC power supply 32 is an AC power supply circuit that outputs an AC voltage V at a preset frequency f to the probe Pr via the scanner unit 31. The ammeter 33 is an AC ammeter constructed using, for example, a shunt resistor, a Hall element, and an analog-to-digital converter. The ammeter 33 measures the current I flowing from the probe Pr connected via the scanner unit 31 to the circuit ground and sends a signal representing the current I to the control unit 2. The voltage V and the current I can be RMS values ​​or peak values.

[0082] Reference Figure 1 The control unit 2 is, for example, a microcomputer consisting of a central processing unit (CPU) that performs prescribed logical operations, a random access memory (RAM) that temporarily stores data, a non-volatile storage device that pre-stores prescribed control programs, and peripheral circuits including these.

[0083] The control unit 2 functions as the inspection control unit 21, the measurement unit 22, the average capacitance calculation unit 23, the capacitance correction unit 24, the reference value calculation unit 25, and the determination unit 26, for example, by executing the control program.

[0084] The inspection control unit 21 moves the inspection unit 3 appropriately, so that each probe Pr contacts each inspection point, such as the end e of the substrate A fixed on the substrate fixing device 12.

[0085] The measuring unit 22 measures the electrostatic capacitance of the wiring of each substrate A as the measuring capacitance. Specifically, the measuring unit 22 measures the electrostatic capacitance between the reference wiring B(n,1) and the planar pattern G(n,1) as the measuring capacitance of the reference wiring B(n,1), measures the electrostatic capacitance between the reference wiring B(n,2) and the planar pattern G(n,2) as the electrostatic capacitance of the reference wiring B(n,2), and measures the electrostatic capacitance between the reference wiring B(n,3) and the planar pattern G(n,3) as the electrostatic capacitance of the reference wiring B(n,3).

[0086] Strictly speaking, the electrostatic capacitance measured by contacting the probe Pr with the reference wiring B(n,1) and the planar pattern G(n,1) also includes the electrostatic capacitance generated between the probe Pr and the material surrounding the reference wiring B(n,1). Similarly, the electrostatic capacitance measured by contacting the probe Pr with the reference wiring B(n,2) and the planar pattern G(n,2) also includes the electrostatic capacitance generated between the probe Pr and the material surrounding the reference wiring B(n,2), and the electrostatic capacitance measured by contacting the probe Pr with the reference wiring B(n,3) and the planar pattern G(n,3) also includes the electrostatic capacitance generated between the probe Pr and the material surrounding the reference wiring B(n,3).

[0087] However, electrostatic capacitance is inversely proportional to distance and directly proportional to area. Therefore, if the distances between the reference wiring B(n,1), reference wiring B(n,2), and reference wiring B(n,3) and their surrounding wirings are large, the electrostatic capacitance between the large-area reference wiring B(n,1) and the planar pattern G(n,1), the electrostatic capacitance between the reference wiring B(n,2) and the planar pattern G(n,2), and the electrostatic capacitance between the reference wiring B(n,3) and the planar pattern G(n,3) will dominate.

[0088] Therefore, the electrostatic capacitance measured by contacting a pair of probes Pr with the reference wiring B(n,1) and the planar pattern G(n,1) can be approximated as the electrostatic capacitance of the reference wiring B(n,1), the electrostatic capacitance measured by contacting a pair of probes Pr with the reference wiring B(n,2) and the planar pattern G(n,2) can be approximated as the electrostatic capacitance of the reference wiring B(n,2), and the electrostatic capacitance measured by contacting a pair of probes Pr with the reference wiring B(n,3) and the planar pattern G(n,3) can be approximated as the electrostatic capacitance of the reference wiring B(n,3).

[0089] Furthermore, the electrostatic capacitance of the wiring Pn can be the electrostatic capacitance between the wiring Pn and all other wirings or patterns, or it can be the electrostatic capacitance between the wiring Pn and one or more pre-defined wirings or patterns. Alternatively, if the carrier substrate 102 is a conductor substrate, the electrostatic capacitance of the wiring Pn can be the electrostatic capacitance between the wiring Pn and the carrier substrate 102. The measuring unit 22 only needs to use the electrostatic capacitance measured between a pair of probes Pr that are in contact with the wiring Pn and any pre-defined wiring or pattern as the measuring capacitance of the wiring Pn.

[0090] The measuring unit 22 connects the ammeter 33 to the probe Pr that contacts the reference wiring Bn or wiring Pn of the object being measured via the scanner unit 31. Additionally, the measuring unit 22 connects the AC power supply 32 to the probe Pr that is paired with the probe Pr via the scanner unit 31.

[0091] In this way, the voltage V with frequency f output by the self-AC power supply 32, and the current I flow through the electrostatic capacitance of the reference wiring Bn or wiring Pn of the object being measured, and the current I is measured by the ammeter 33.

[0092] When a voltage V of frequency f is applied to an electrostatic capacitor X and a current I flows, the electrostatic capacitor X is given by the following equation (1).

[0093] The electrostatic capacitance X = I / (V×2πf)···(1)

[0094] In this case, since V and 2πf are known, the electrostatic capacitance X can be determined if the current I is obtained. Therefore, the measuring unit 22 can measure the electrostatic capacitance X as the measuring capacitance C.

[0095] Hereinafter, the case in which the measuring unit 22 uses the scanner unit 31, the AC power supply 32 and the ammeter 33 to measure the electrostatic capacitance X will be described only as the measuring unit 22 measuring the electrostatic capacitance X, i.e., the measuring capacitance C.

[0096] The average capacitance calculation unit 23 calculates the average value of the measured capacitance C obtained from the corresponding wirings as the average capacitance Cav. The term "corresponding wirings" refers to wirings that are designed and manufactured with identical wiring patterns for each substrate A. For example, wirings with the same numbering are: reference wiring B(1,1), reference wiring B(2,1), reference wiring B(3,1), ... are corresponding wirings; reference wiring B(1,2), reference wiring B(2,2), reference wiring B(3,2), ... are corresponding wirings; and reference wiring B(1,3), reference wiring B(2,3), reference wiring B(3,3), ... are corresponding wirings.

[0097] When substrate Ai with substrate number i among multiple substrates A1 to A25 is used as the target substrate, the capacitance correction unit 24 calculates the correction value, i.e., the correction capacitance Cc, of the target wiring by multiplying the ratio of the average capacitance Cav of the wiring of the target substrate Ai to the measured capacitance Ci by the measured capacitance C of the target wiring that is the object of inspection of the target substrate Ai.

[0098] Furthermore, the capacitance correction unit 24 calculates the correction capacitance Cc relative to the target wiring of each substrate A by sequentially using each substrate A as the target substrate.

[0099] The reference value calculation unit 25 calculates the average value of the correction capacitance Cc relative to the target wiring of each substrate A as the judgment reference value Cref.

[0100] The determination unit 26 determines the correction capacitor Cc based on the determination reference value Cref.

[0101] Next, refer to Figures 5-8 An example of the operation of a substrate inspection apparatus 1 implementing an example of the inspection method of the present invention will be described. In the following description, the measurement capacitance of the reference wiring B(i,j) is referred to as C(B(i,j)), the measurement capacitance of wiring P(i,j) is referred to as C(P(i,j)), and the correction capacitance of wiring P(i,j) is referred to as Cc(p(i,j)).

[0102] First, the measuring unit 22 initializes the substrate number i to 1 (step S1).

[0103] Next, the inspection control unit 21 contacts each probe Pr with the first layer L1 of the substrate Ai. Specifically, each probe Pr contacts any wires that are paired with reference wiring B(i,1) to reference wiring B(i,3), wiring P(i,1) to wiring P(i,5), planar pattern G(i,1) to planar pattern G(i,3), and wiring P(i,1) to wiring P(i,5).

[0104] Next, the measurement unit 22 measures the measurement capacitors C(B(i,1)), C(B(i,2), C(B(i,3), C(P(i,1)), C(P(i,2)), C(P(i,3)), C(P(i,4)), and C(P(i,5)) (step S2: measurement process).

[0105] Next, the measurement unit 22 compares substrate number i with 25 (step S3). If substrate number i is not 25 (NO in step S3), then substrate number i is incremented by 1 in order to measure the new substrate A (step S4), and steps S2 and S3 are repeated. On the other hand, if substrate number i is 25 (YES in step S3), then the measurement capacitance C of all wiring is measured, and the process is transferred to step S5.

[0106] Next, the average capacitance calculation unit 23 uses the average value of the measured capacitance C(B(1,1)) to the measured capacitance C(B(25,1)) as the average capacitance Cav(L1) of the first layer L1, the average value of the measured capacitance C(B(1,2)) to the measured capacitance C(B(25,2)) as the average capacitance Cav(L2) of the second layer L2, and the average value of the measured capacitance C(B(1,3)) to the measured capacitance C(B(25,3)) as the average capacitance Cav(L3) of the third layer L3 (step S5: average capacitance calculation process).

[0107] The measured capacitances C(B(1,1)) to C(B(25,1)) are the measured capacitances of the reference wiring B corresponding to wiring number 1, i.e., the reference wiring B formed in the first layer L1. The measured capacitances C(B(1,2)) to C(B(25,2)) are the measured capacitances of the reference wiring B corresponding to wiring number 2, i.e., the reference wiring B formed in the second layer L2. The measured capacitances C(B(1,3)) to C(B(25,3)) are the measured capacitances of the reference wiring B corresponding to wiring number 3, i.e., the reference wiring B formed in the third layer L3.

[0108] Furthermore, an example is shown where a reference wiring B is provided on each layer of a substrate A, but multiple reference wirings B may also be included in each layer. Moreover, the measured capacitance C of the multiple reference wirings B of each substrate may be averaged with respect to each layer of the multiple substrates to calculate the average capacitance Cav(L1), average capacitance Cav(L2), and average capacitance Cav(L3).

[0109] Next, the capacitor correction unit 24 initializes the substrate number i to 1 (step S6).

[0110] Next, the capacitor correction unit 24 calculates the correction capacitance Cc(P(i,1)) of the wiring P(i,1) of the first layer L1 based on the following formula (1) (step S7: capacitor correction process).

[0111] The corrected capacitance is Cc(P(i,1))=C(P(i,1))×Cav(L1) / C(B(i,1))···(1)

[0112] In step S7, substrate Ai corresponds to target substrate, wiring P(i,1) corresponds to target wiring of first layer L1, reference wiring B(i,1) corresponds to wiring of target substrate Ai, and Cav(L1) / C(B(i,1)) corresponds to the ratio of average capacitance Cav(L1) of wiring of target substrate Ai to measured capacitance C(B(i,1)).

[0113] Next, the capacitor correction unit 24 calculates the correction capacitors Cc(P(i,2)) and Cc(P(i,3)) of the wiring P(i,2) and wiring P(i,3) of the second layer L2 based on the following equations (2) and (3) (step S8: capacitor correction process).

[0114] The corrected capacitance is Cc(P(i,2))=C(P(i,2))×Cav(L2) / C(B(i,2))···(2)

[0115] Corrected capacitance Cc(P(i,3))=C(P(i,3))×Cav(L2) / C(B(i,2))···(3)

[0116] In step S8, substrate Ai corresponds to target substrate, wiring P(i,2) and wiring P(i,3) correspond to target wiring of second layer L2, reference wiring B(i,2) corresponds to wiring of target substrate Ai, and Cav(L2) / C(B(i,2)) corresponds to the ratio of average capacitance Cav(L2) of wiring of target substrate Ai to measured capacitance C(B(i,2)).

[0117] Next, the capacitor correction unit 24 calculates the correction capacitor Cc(P(i,4)) and correction capacitor Cc(P(i,5)) of the wiring P(i,4) and wiring P(i,5) of the third layer L3 based on the following equations (4) and (5) (step S9: capacitor correction process).

[0118] Corrected capacitance Cc(P(i,4))=C(P(i,4))×Cav(L3) / C(B(i,3))···(4)

[0119] Corrected capacitance Cc(P(i,5))=C(P(i,5))×Cav(L3) / C(B(i,3))···(5)

[0120] In step S9, substrate Ai corresponds to target substrate, wiring P(i,4) and wiring P(i,5) correspond to target wiring of third layer L3, reference wiring B(i,3) corresponds to wiring of target substrate Ai, and Cav(L3) / C(B(i,3)) corresponds to the ratio of average capacitance Cav(L3) of wiring of target substrate Ai to measured capacitance C(B(i,3)).

[0121] Next, the capacitance correction unit 24 compares substrate number i with 25 (step S10). If substrate number i is not 25 (no in step S10), then substrate number i is incremented by 1 in order to correct the new substrate A (step S11), and steps S7 to S10 are repeated again. On the other hand, if substrate number i is 25 (yes in step S10), then the correction of all measured capacitances C is completed, and the process is transferred to step S21.

[0122] like Figure 9 As shown, even for wirings P with the same wiring number, the measured capacitance C varies on each substrate A. When wiring P is broken, the measured capacitance C decreases; when wiring P is short-circuited with other wirings, the measured capacitance C increases. If there is no substrate deviation, the increase or decrease in measured capacitance C can be used to determine whether wiring P is broken or short-circuited.

[0123] However, if Figure 9 As shown, if the deviation of the substrate causes a large deviation in the measuring capacitance C, it will be difficult to determine whether the wiring P is open or short-circuited based on the measuring capacitance C.

[0124] For example, regarding Figure 9 The measured capacitance C(P(2,2)) shown is represented by a solid line when wiring P(2,2) is broken, and by a dashed line when wiring P(2,2) is normal. Figure 9 In the example shown, the measured capacitance C(P(2,2)) of the disconnected wiring P(2,2) is smaller than that of the normal wiring P(1,2) but larger than that of the normal wiring P(25,2) . Therefore, it is difficult to determine the wiring P(2,2) as defective based solely on the measured capacitance C(P(2,2)).

[0125] like Figure 10 As shown, regarding the correction capacitors Cc(P(1,1)) to Cc(P(25,5)) corrected in steps S7 to S9, if they are normal wiring P, then among the wiring Ps with the same wiring number and corresponding to each other, the influence of substrate deviation is reduced, and they become electrostatic capacitances of approximately the same degree. Thus, according to steps S1 to S11, the deviation of electrostatic capacitance X caused by manufacturing deviation of substrate A can be easily corrected.

[0126] Furthermore, in the manufacturing process of substrate A, since wiring P and reference wiring B are formed in each layer, even within the same substrate A, the deviation pattern in each layer may sometimes be different. Therefore, in step S2, the measured capacitances C(B(1,1)) to C(B(25,3)) are measured from the reference wirings B(n,1) to B(n,3) provided in each layer. In step S5, the average capacitances Cav(L1), Cav(L2), and Cav(L3) are calculated for each layer. In steps S7 to S9, the corrected capacitances Cc(P(1,1)) to Cc(P(25,5)) are calculated for each layer.

[0127] Therefore, the correction capacitors Cc(P(1,1)) to Cc(P(25,5)) can be calculated to reduce the difference in deviation between each layer.

[0128] Next, in step S21, the reference value calculation unit 25 uses the average value of the correction capacitors Cc(P(1,1)) to Cc(P(25,1)) as the determination reference value Cref(1) for wiring P(n,1), uses the average value of the correction capacitors Cc(P(1,2)) to Cc(P(25,2)) as the determination reference value Cref(2) for wiring P(n,2), and uses the average value of the correction capacitors Cc(P(1,3)) to Cc(P(25,1)) as the determination reference value Cref(2) for wiring P(n,2). The average value of the correction capacitors Cc(P(1,4)) to Cc(P(25,4)) is used as the judgment reference value Cref(3) for wiring P(n,3). The average value of the correction capacitors Cc(P(1,4)) to Cc(P(25,4)) is used as the judgment reference value Cref(4) for wiring P(n,4). The average value of the correction capacitors Cc(P(1,5)) to Cc(P(25,5)) is used as the judgment reference value Cref(5) for wiring P(n,5) (Step S21: Reference value calculation process).

[0129] Next, the determination unit 26 initializes the substrate number i and the wiring number j to 1 (step S22).

[0130] Next, if the absolute value of {Cc(P(i,j))-Cref(j)} / Cref(j) is below the determination ratio Ref (yes in step S23), then the determination unit 26 determines that the wiring P(i,j) is good (step S24); if it exceeds the determination ratio Ref (no in step S23), then the determination unit 26 determines that the wiring P(i,j) is bad (step S25).

[0131] That is, when the ratio of the difference between the correction capacitance Cc and the judgment reference value CRef of each wiring P to the judgment reference value Cref exceeds a preset judgment ratio Ref, the judgment unit 26 can determine that the wiring P is defective. The judgment ratio Ref can be set appropriately according to the required inspection accuracy.

[0132] Next, the determination unit 26 compares the wiring number j with 5 (step S26). If the wiring number j is not 5 (no in step S26), the wiring number j is incremented by 1 in order to determine other wiring P in the substrate Ai (step S27), and steps S23 to S26 are repeated again.

[0133] On the other hand, if the wiring number j is 5 (yes in step S26), the substrate number i is compared with 25 (step S28). If the substrate number i is not 25 (no in step S28), the substrate number i is incremented by 1 in order to determine the new substrate A, and the wiring number j is initialized to 1 (step S29). Steps S23 to S28 are repeated again.

[0134] On the other hand, if the substrate number i is 25 (yes in step S28), then for all wiring P, the determination of whether the end is good is carried out, and therefore the process is transferred to step S30.

[0135] In step S30, the determination unit 26 confirms whether there is a wiring P that was determined to be defective in step S25 (step S30). If there is no wiring P that was determined to be defective (no in step S30), the process ends.

[0136] On the other hand, if there is a wiring P that is determined to be faulty (yes in step S30), the process proceeds to step S41.

[0137] Even if there is a faulty wiring P (in step S30), the correction capacitor Cc of the faulty wiring P is included, and the average value calculated in step S21 is used as the judgment benchmark value Cref. Therefore, the accuracy of determining whether wiring P is good or bad based on the judgment benchmark value Cref decreases.

[0138] Therefore, in step S41, the reference value calculation unit 25 uses the average value of the remaining correction capacitors after removing the correction capacitors of the wiring determined to be defective from the self-correction capacitor Cc(P(1,1)) to the correction capacitor Cc(P(25,1)) as the new judgment reference value Cref(1) of the wiring P(n,1).

[0139] Similarly, the reference value calculation unit 25 uses the average value of the remaining correction capacitors after removing the correction capacitors of the wiring that are judged to be defective from the self-correction capacitors Cc(P(1,2)) to the correction capacitors Cc(P(25,2)) as the new judgment reference value Cref(2) of the wiring P(n,2) (step S41).

[0140] The reference value calculation unit 25 takes the average value of the remaining correction capacitors after removing the correction capacitors of the wiring judged as defective from the self-correction capacitors Cc(P(1,3)) to the correction capacitors Cc(P(25,3)) as the new judgment reference value Cref(3) of the wiring P(n,3) (step S41).

[0141] The reference value calculation unit 25 takes the average value of the remaining correction capacitors after removing the correction capacitors of the wiring judged as defective from the self-correction capacitors Cc(P(1,4)) to the correction capacitors Cc(P(25,4)) as the new judgment reference value Cref(4) of the wiring P(n,4) (step S41).

[0142] The reference value calculation unit 25 takes the average value of the remaining correction capacitors after removing the correction capacitors of the wiring judged as defective from the self-correction capacitors Cc(P(1,5)) to the correction capacitors Cc(P(25,5)) as the new judgment reference value Cref(5) of the wiring P(n,5) (step S41).

[0143] According to step S41, in the case of defective wiring, a new judgment benchmark value Cref can be calculated based on the remaining correction capacitor after removing the correction capacitor of the defective wiring, thus improving the accuracy of the judgment benchmark value Cref.

[0144] Next, the determination unit 26 initializes the substrate number i and the wiring number j to 1 (step S42).

[0145] Next, the determination unit 26 checks whether the wiring P(i,j) is faulty in step S25 (step S43). If the wiring P(i,j) is not faulty (no in step S43), the determination unit 26 transfers the process to step S51. If the wiring P(i,j) is faulty (yes in step S43), the determination unit 26 transfers the process to step S54.

[0146] In step S51, if the absolute value of {Cc(P(i,j))-Cref(j)} / Cref(j) is below the determination ratio Ref based on the new determination benchmark value CRef (yes in step S51), then the determination unit 26 determines that the wiring P(i,j) is good (step S52). If it exceeds the determination ratio Ref, then the determination unit 26 determines that the wiring P(i,j) is bad (step S53).

[0147] Next, the determination unit 26 compares the wiring number j with 5 (step S54). If the wiring number j is not 5 (no in step S54), then in order to determine other wiring P in the substrate Ai, the wiring number j is incremented by 1 (step S55), and steps S51 to S54 are repeated again.

[0148] On the other hand, if the wiring number j is 5 (yes in step S54), the substrate number i is compared with 25 (step S56). If the substrate number i is not 25 (no in step S56), the substrate number i is incremented by 1 in order to determine the new substrate A, and the wiring number j is initialized to 1 (step S57). Steps S51 to S56 are repeated again.

[0149] On the other hand, if the substrate number i is 25 (yes in step S56), then for all wiring P that was not defective in the previous step, the determination of whether it is good or bad is completed based on the new determination criterion value Cref, and the process is transferred to step S58.

[0150] In step S58, the determination unit 26 checks whether there is a newly determined faulty wiring P that was newly determined in step S53 (step S58). If there is no newly determined faulty wiring P (no in step S58), the process ends.

[0151] On the other hand, as long as there is a new wiring P that is determined to be defective (yes in step S58), steps S41 to S58 are repeated again.

[0152] Based on the above processing steps S30 and S41 to S58, in the case of a defective wiring P, the influence of the defective wiring P is eliminated, the judgment benchmark value Cref is recalculated, and based on the recalculated judgment benchmark value Cref, the goodness of the wiring P that was judged as good is re-judged. Therefore, the accuracy of the goodness judgment of wiring P is improved.

[0153] Furthermore, it is not necessary to execute steps S30 to S53; the process can be terminated if the condition in step S28 is "yes".

[0154] Furthermore, it is not limited to the example of setting the reference wiring B on each layer of the substrate A. For example, it is also possible to include only the reference wiring B(n,2) as the reference wiring, and in steps S7 and S9, Cav(L2) / C(B(i,2)) is used instead of Cav(L1) / C(B(i,1)) and Cav(L3) / C(B(i,3)).

[0155] Furthermore, the example of including reference wiring B separately from wiring P, which is the object of inspection, is not limited to. Reference wiring B may also be omitted, and any of wiring P may be used in place of reference wiring B. For example, wiring P(n,2) and wiring P(n,4) may be used in place of reference wiring B(n,2) and reference wiring B(n,3).

[0156] In this case, in step S5, the average value of the measured capacitances C(P(1,2)) to C(P(25,2)) can be used as the average capacitance Cav(L2) of the second layer L2, and the average value of the measured capacitances C(P(1,4)) to C(P(25,4)) can be used as the average capacitance Cav(L3) of the third layer L3. Alternatively, in step S8, the measured capacitance C(P(i,2)) can be used instead of the measured capacitance C(B(i,2)), and in step S9, the measured capacitance C(P(i,4)) can be used instead of the measured capacitance C(B(i,3)).

[0157] Therefore, although wiring P(n, 2) and wiring P(n, 4) cannot be checked in steps S23 to S25 and steps S51 to S53, wiring P(n, 3) and wiring P(n, 5) can be checked. When checking wiring P(n, 2) and wiring P(n, 4), wiring P(n, 3) and wiring P(n, 5) can be used to replace the reference wiring B(n, 2) and reference wiring B(n, 3).

[0158] If so, it is not necessary to include the reference wiring B separately from the wiring P. On the other hand, if the wiring P, which is wound in order to form the circuit, is wound in a complex manner, it is easy to form a complex shape, and the electrostatic capacitance X is easy to become unstable. However, if the structure is designed so that the reference wiring B is included separately from the wiring P, it is easy to make the reference wiring B used for average capacitance calculation into a shape and configuration that makes the electrostatic capacitance easy to stabilize, regardless of the necessity of the circuit.

[0159] Furthermore, as long as the substrate inspection apparatus and inspection method of the present invention can easily correct the deviation of electrostatic capacitance caused by the manufacturing deviation of the substrate, steps S21 to S58 can be omitted, and the process can be terminated if the result in step S10 is yes.

[0160] Additionally, an example is shown where wiring P, which is temporarily determined to be faulty in step S43, is not re-evaluated in steps S51 to S53. However, step S43 may be skipped, and the process may proceed from step S42 to step S51.

[0161] That is, an inspection apparatus according to an example of the present invention inspects multiple substrates having wirings that are designed to be identical. The inspection apparatus includes: a measurement unit that measures the electrostatic capacitance of the wirings of each substrate as a measurement capacitance; an average capacitance calculation unit that calculates the average value of the measurement capacitances measured from the wirings designed to be identical as an average capacitance; and a capacitance correction unit that, when one of the multiple substrates is selected as a target substrate, calculates a correction value, i.e., a correction capacitance, for the measurement capacitance of the target wiring that is the object of inspection of the target substrate. The capacitance correction unit calculates the correction capacitance by multiplying the ratio of the average capacitance of the wirings of the target substrate to the measurement capacitance by the measurement capacitance of the target wiring.

[0162] In addition, one example of the inspection method of the present invention inspects multiple substrates having wirings that are designed to be identical. The inspection method includes: a measurement step, measuring the electrostatic capacitance of the wirings of each substrate as a measurement capacitance; an average capacitance calculation step, calculating the average value of the measurement capacitances measured from the wirings designed to be identical as an average capacitance; and a capacitance correction step, in the case of taking one of the multiple substrates as a target substrate, calculating a correction value, i.e., a correction capacitance, of the measurement capacitance of the target wiring that is the object of inspection of the target substrate. The capacitance correction step calculates the correction capacitance by multiplying the ratio of the average capacitance of the wirings of the target substrate to the measurement capacitance by the measurement capacitance of the target wiring.

[0163] Based on these structures, the electrostatic capacitance of the wiring on each substrate is measured as the test capacitance, and the average capacitance is calculated as the average capacitance of corresponding wirings that are designed to be identical. Furthermore, the correction capacitance of the target wiring is calculated by multiplying the ratio of the average capacitance of the wiring on one of the target substrates to the test capacitance by the test capacitance of the target wiring on the target substrate. As a result, the deviation between substrates in the correction capacitance is reduced, thus making it easier to correct deviations in electrostatic capacitance caused by substrate manufacturing variations.

[0164] Alternatively, the capacitance correction unit preferably uses the plurality of substrates as target substrates and calculates the correction capacitance of the target wiring of each target substrate. The inspection device further includes: a reference value calculation unit that calculates the average value of each correction capacitance as a judgment reference value; and a judgment unit that judges each correction capacitance based on the judgment reference value.

[0165] Based on the structure described above, the judgment reference value can be automatically calculated based on the correction capacitance of the target wiring of each target substrate, thus making it easy to judge each correction capacitance.

[0166] Alternatively, the reference value calculation unit preferably calculates the average value of the remaining correction capacitors after removing the correction capacitors determined as defective by the determination unit as a new determination reference value, and the determination unit determines at least the remaining correction capacitors based on the new determination reference value.

[0167] According to the structure, the correction capacitor for defective wiring is excluded from the data that serves as the basis for the judgment benchmark value, and a new judgment benchmark value is calculated. Therefore, the judgment accuracy based on the new judgment benchmark value is improved.

[0168] Alternatively, the wiring may not include the inspection object, but rather a reference wiring that is designed to be identical among the plurality of substrates. The measurement unit measures the electrostatic capacitance of the reference wiring as the measurement capacitance of the reference wiring, and the average capacitance calculation unit calculates the average value of the measurement capacitance of the reference wiring in each substrate as the average capacitance.

[0169] According to the aforementioned structure, the average capacitance is calculated based on the measurement capacitance measured from a reference wiring separate from the wiring to be inspected. The wiring to be inspected, wound in order to form the circuit, is complexly wound and tends to have a complex shape, making the electrostatic capacitance prone to instability. However, when the structure includes a reference wiring separate from the wiring to be inspected, the reference wiring used for calculating the average capacitance can be made into a shape and configuration where the electrostatic capacitance is easily stabilized, regardless of the circuit's necessity.

[0170] In addition, it is preferable that the substrate is a multilayer substrate, and the reference wiring is disposed on each layer of the substrate.

[0171] In the substrate manufacturing process, since wiring and reference wiring are formed on each layer, even within the same substrate, the deviation patterns can sometimes differ between layers. Therefore, by setting reference wiring on each layer of the substrate, it is easy to calculate correction capacitance, thereby reducing the difference in deviation between layers.

[0172] Alternatively, it is preferable to include a probe for contacting the wiring, via which the measuring unit measures the electrostatic capacitance.

[0173] According to the structure described, the electrostatic capacitance of the wiring can be measured by bringing the probe into contact with the wiring.

Claims

1. An inspection apparatus that inspects a plurality of substrates each of which has a wiring formed therein that is designed to be the same wiring, and in which the inspection apparatus comprises: a measurement unit that measures electrostatic capacitance of the wiring of each of the substrates as a measurement capacitance; an average capacitance calculation unit that calculates an average value of the measurement capacitances measured from the wirings designed to be the same wiring as an average capacitance; and a capacitance correction unit that, in a case where one of the plurality of substrates is taken as a target substrate, calculates a correction value of the measurement capacitance of a target wiring that is an inspection target of the target substrate as a correction capacitance, and the capacitance correction unit calculates the correction capacitance by multiplying a ratio of the average capacitance of the wiring of the target substrate to the measurement capacitance by the measurement capacitance of the target wiring.

2. The inspection apparatus according to claim 1, wherein the capacitance correction unit calculates the correction capacitance of the target wiring of each of the target substrates taken as the plurality of substrates, a reference value calculation unit calculates an average value of the each correction capacitance as a determination reference value, and a determination unit determines the each correction capacitance based on the determination reference value.

3. The inspection apparatus according to claim 2, wherein the reference value calculation unit calculates an average value of the correction capacitances remaining after correction capacitances determined as defective by the determination unit are removed as a new determination reference value, and the determination unit determines at least the remaining correction capacitances based on the new determination reference value.

4. The inspection apparatus according to claim 1, wherein the wiring does not include an inspection target but includes a reference wiring that is designed to be the same wiring among the plurality of substrates, the measurement unit measures electrostatic capacitance of the reference wiring as a measurement capacitance of the reference wiring, and the average capacitance calculation unit calculates an average value of the measurement capacitances of the reference wiring in the each of the substrates as the average capacitance.

5. The inspection apparatus according to claim 4, wherein the substrate is a multilayer substrate, and the reference wiring is provided to each layer of the substrate.

6. The inspection apparatus according to any one of claims 1 to 5, comprising a probe to be brought into contact with the wiring, and the measurement unit measures the electrostatic capacitance via the probe.

7. An inspection method that inspects a plurality of substrates each of which has a wiring formed therein that is designed to be the same wiring, and in which the inspection method comprises: a measurement step of measuring electrostatic capacitance of the wiring of each of the substrates as a measurement capacitance; an average capacitance calculation step of calculating an average value of the measurement capacitances measured from the wirings designed to be the same wiring as an average capacitance; and a capacitance correction step of, in a case where one of the plurality of substrates is taken as a target substrate, calculating a correction value of the measurement capacitance of a target wiring that is an inspection target of the target substrate as a correction capacitance, and the capacitance correction step calculates the correction capacitance by multiplying a ratio of the average capacitance of the wiring of the target to the measurement capacitance by the measurement capacitance of the target wiring. ​ The inspection device further comprises: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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