Electronic circuit and method for detecting faults in an electronic circuit

Abstract

This system detects short-circuit faults in series-connected capacitors while suppressing increases in circuit size and area. [Solution] The electronic circuit includes a plurality of diode circuits, each including a first circuit containing a plurality of capacitors connected in series, one or more resistors, and one or more diodes connected in series, and a second circuit containing one or more diodes connected in series and connected in antiparallel to the first circuit. One end of one capacitor on one side of the plurality of capacitors is electrically connected to the first terminal, and the other end of one capacitor on the other side of the plurality of capacitors is electrically connected to the second terminal. One or more resistors are electrically connected in parallel to each of the remaining capacitors, excluding one capacitor on the other side of the plurality of capacitors. One end of each of the plurality of diode circuits is electrically connected to one end of each of the plurality of capacitors, and the other end of each of the plurality of diode circuits is electrically connected to the second terminal.

Description

Technical Field

[0001] The present disclosure relates to an electronic circuit and a method for detecting a failure of an electronic circuit.

Background Art

[0002] Patent Document 1 below describes a failure detection circuit for detecting a short-circuit failure of two capacitors connected in series.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to detect a short-circuit failure of a plurality of capacitors connected in series, it is conceivable to provide a terminal that is electrically connected between the capacitors. However, in a semiconductor device, a detection terminal may be larger in size than circuit components such as capacitors, resistors, and diodes. In addition, it is necessary to provide a physical gap between terminals on the substrate, particularly when the terminals are configured as bumps. Therefore, if a terminal electrically connected between the capacitors is provided, the size of the semiconductor device increases.

[0005] Even in the failure detection circuit described in Patent Document 1, the circuit increases and the area increases.

[0006] The present disclosure has been made in view of the above, and an object thereof is to be able to detect a short-circuit failure of capacitors connected in series while suppressing an increase in the circuit and an increase in the area.

Means for Solving the Problems

[0007] An electronic circuit in one aspect of the present disclosure includes a plurality of diode circuits, each including a first circuit comprising a plurality of capacitors connected in series, one or more resistors, and one or more diodes connected in series, and a second circuit comprising one or more diodes connected in series and connected in antiparallel to the first circuit. One end of one capacitor on one side of the plurality of capacitors is electrically connected to the first terminal, and the other end of one capacitor on the other side of the plurality of capacitors is electrically connected to the second terminal. One or more resistors are electrically connected in parallel to each of the remaining capacitors, excluding one capacitor on the other side of the plurality of capacitors. One end of each of the plurality of diode circuits is electrically connected to one end of each of the plurality of capacitors, and the other end of each of the plurality of diode circuits is electrically connected to the second terminal.

[0008] One aspect of the present disclosure is a fault detection method for an electronic circuit, which involves applying a predetermined voltage to a first terminal at least once, detecting the current flowing into the first terminal at least once, and comparing the current flowing into the first terminal with the current flowing into the first terminal at least once when a voltage is applied to a good electronic circuit, thereby detecting whether or not there is a short-circuit fault in multiple capacitors. [Effects of the Invention]

[0009] The electronic circuit of this disclosure makes it possible to detect short-circuit failures of series-connected capacitors while suppressing increases in circuit size and area. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 shows the configuration of the electronic circuit of the first embodiment. [Figure 2] Figure 2 shows the electronic circuit of the first embodiment and the fault detection device for the electronic circuit. [Figure 3] Figure 3 shows the relationship between the voltage applied to the electronic circuit of the first embodiment and the current flowing into it. [Figure 4]Figure 4 is a flowchart of the fault detection method for an electronic circuit according to the first embodiment. [Figure 5] Figure 5 shows the configuration of the electronic circuit in the second embodiment. [Figure 6] Figure 6 shows the relationship between the voltage applied to the electronic circuit of the second embodiment and the current flowing into it. [Figure 7] Figure 7 is a flowchart of the fault detection method for an electronic circuit according to the second embodiment. [Figure 8] Figure 8 is a flowchart of the fault detection method for an electronic circuit according to the third embodiment. [Modes for carrying out the invention]

[0011] The embodiments of this disclosure will be described in detail below with reference to the drawings. However, the present invention is not limited by these embodiments. Each embodiment is illustrative, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. In the second and subsequent embodiments, descriptions of matters common to the first embodiment will be omitted, and only the differences will be described. In particular, similar effects and advantages due to similar configurations will not be mentioned sequentially for each embodiment.

[0012] <First Embodiment> (composition) Figure 1 shows the configuration of the electronic circuit of the first embodiment.

[0013] In the first embodiment, the electronic circuit 1 is formed on the semiconductor device 100, but the disclosure is not limited thereto.

[0014] Electronic circuit 1 includes a capacitor Ca, a capacitor Cb, a resistor Ra, a diode circuit Da, a diode circuit Db, and an inductor 101.

[0015] One end of the capacitor Ca is electrically connected to the terminal 1a. The other end of the capacitor Ca is electrically connected to one end of the capacitor Cb. The other end of the capacitor Cb is electrically connected to one end of the inductor 101.

[0016] The other end of the inductor 101 is electrically connected to the terminal 1b. The terminal 1b is electrically connected to the reference potential. The reference potential is exemplified by the ground potential, but the present disclosure is not limited thereto. The inductor 101 is electromagnetically coupled to the inductor 102.

[0017] That is, the capacitors Ca and Cb are connected in series between the terminals 1a and 1b.

[0018] In this specification, the "first terminal" refers to the terminal 1a. In this specification, the "second terminal" refers to the terminal 1b. "Terminal" means, for example, a pad or a bump.

[0019] The resistor Ra is electrically connected in parallel to the capacitor Ca.

[0020] In this embodiment, the resistance value of the resistor Ra is 1 kΩ (kiloohm), but the present disclosure is not limited thereto.

[0021] The diode circuit Da includes a first circuit Da1 and a second circuit Da2.

[0022] The first circuit Da1 includes two diodes connected in series. The anode of the first circuit Da1 is electrically connected to one end of the capacitor Ca, and the cathode is electrically connected to the terminal 1b.

[0023] The second circuit Da2 includes two diodes connected in series. The anode of the second circuit Da2 is electrically connected to the terminal 1b, and the cathode is electrically connected to one end of the capacitor Ca.

[0024] In this embodiment, the number of diodes in the first circuit Da1 and the number of diodes in the second circuit Da2 are assumed to be the same, but this disclosure is not limited thereto. The number of diodes in the first circuit Da1 and the number of diodes in the second circuit Da2 may be different.

[0025] The first circuit Da1 conducts when the voltage between terminals 1a and 1b exceeds a threshold voltage, protecting other circuit components.

[0026] In this embodiment, the threshold voltage of the first circuit Da1 is the threshold voltage of two diodes. For example, if the threshold voltage of one diode is 1.2V, then the threshold voltage of two diodes is 2.4V.

[0027] The second circuit Da2 conducts when the voltage between terminal 1b and terminal 1a exceeds a threshold voltage, protecting other circuit components.

[0028] In this embodiment, the threshold voltage of the second circuit Da2 is the threshold voltage of two diodes, which is, for example, 2.4V.

[0029] The diode circuit Db includes a first circuit Db1 and a second circuit Db2.

[0030] The first circuit Db1 includes one diode. The anode of the first circuit Db1 is electrically connected to one end of capacitor Cb, and the cathode is electrically connected to terminal 1b.

[0031] The second circuit Db2 includes one diode. The anode of the second circuit Db2 is electrically connected to terminal 1b, and the cathode is electrically connected to one end of capacitor Cb.

[0032] In this embodiment, the number of diodes included in the first circuit Db1 and the number of diodes included in the second circuit Db2 are assumed to be the same, but this disclosure is not limited thereto. The number of diodes included in the first circuit Db1 and the number of diodes included in the second circuit Db2 may be different.

[0033] The first circuit Db1 conducts when the voltage between one end of capacitor Cb and terminal 1b exceeds a threshold voltage, protecting other circuit components.

[0034] In this embodiment, the threshold voltage of the first circuit Db1 is the threshold voltage of one diode, which is, for example, 1.2V.

[0035] The second circuit Db2 conducts when the voltage between terminal 1b and one end of capacitor Cb exceeds a threshold voltage, protecting other circuit components.

[0036] In this embodiment, the threshold voltage of the second circuit Db2 is the threshold voltage of one diode, which is, for example, 1.2V.

[0037] The first circuit Da1 and the second circuit Da2 are connected in antiparallel. The first circuit Db1 and the second circuit Db2 are connected in antiparallel. In this specification, "antiparallel connection" means that the input and output directions of the diodes in the first circuit and the input and output directions of the diodes in the second circuit are opposite in the circuit diagram, and the second circuit is connected in parallel with the first circuit. The connection relationship between the first circuit and the second circuit is also called a "back-to-back connection". Furthermore, diode circuits Da and Db may each be called a "back-to-back diode".

[0038] Electronic circuit 1 becomes an input circuit (e.g., an input matching circuit) when a high-frequency signal RFin is input to terminal 1a. Electronic circuit 1 becomes an output circuit (e.g., an output matching circuit) when a high-frequency signal RFout is output from terminal 1a.

[0039] Electronic circuit 1, having capacitors Ca and Cb connected in series, achieves the following effects.

[0040] For example, let's assume that the capacitance values ​​of capacitor Ca and capacitor Cb are the same. If the capacitance values ​​of capacitor Ca and capacitor Cb are 2C0, then the combined capacitance of capacitors Ca and Cb connected in series is C0.

[0041] In other words, capacitors Ca and Cb connected in series are equivalent to a single capacitor with capacitance value C0 from the standpoint of impedance matching.

[0042] However, the capacitance values ​​of capacitor Ca and capacitor Cb are 2C0. In other words, compared to the case where electronic circuit 1 has one capacitor with capacitance value C0, the capacitance values ​​of capacitor Ca and capacitor Cb can be made larger.

[0043] As a result, the electronic circuit 1 can be made more resistant to electrostatic discharge (ESD) in various test models such as the Charged Device Model (CDM).

[0044] (Fault detection method) This document describes a method for detecting short-circuit faults in capacitors Ca and Cb.

[0045] Figure 2 shows the electronic circuit of the first embodiment and the fault detection device for the electronic circuit.

[0046] The fault detection device 200 includes a variable constant voltage source 201, a current sensor 202, and a control unit 203.

[0047] The low-potential end of the variable constant voltage source 201 is electrically connected to a reference potential. The high-potential end of the variable constant voltage source 201 is electrically connected to one end of the current sensor 202. The other end of the current sensor 202 is electrically connected to terminal 1a.

[0048] The control unit 203 outputs a control signal S1 to the variable constant voltage source 201 and controls the DC voltage V output by the variable constant voltage source 201. The current sensor 202 detects the DC current I flowing from the variable constant voltage source 201 into the electronic circuit 1 and outputs a detection signal S2 representing the DC current I to the control unit 203. The control unit 203 receives the detection signal S2 from the current sensor 202.

[0049] Figure 3 shows the relationship between the voltage applied to the electronic circuit of the first embodiment and the current flowing into it. In Figure 3, the horizontal axis represents the DC voltage V (volts) applied to the electronic circuit 1, and the vertical axis represents the DC current I (milliamperes) flowing into the electronic circuit 1.

[0050] Line 301 shows the relationship between the DC voltage V and DC current I when (A) electronic circuit 1 is functioning correctly. Electronic circuit 1 is functioning correctly when both capacitor Ca and capacitor Cb are not short-circuited.

[0051] Line 302 shows the relationship between the DC voltage V and the DC current I when capacitor Ca (B) is short-circuited and capacitor Cb is not short-circuited.

[0052] Line 303 shows the relationship between the DC voltage V and the DC current I when capacitor Ca (C) is not short-circuited and capacitor Cb is short-circuited.

[0053] Lines 301, 302, and 303 are all symmetrical with respect to the origin. Therefore, we will only explain the case where the DC voltage V is 0 volts or greater, and omit the explanation for the case where the DC voltage V is less than 0 volts.

[0054] First, we will explain the case where (A) electronic circuit 1 is a good product (see line 301).

[0055] In case (A), the path through which the DC current I flows is either (1) terminal 1a → resistor Ra → diode circuit Db (first circuit Db1) → terminal 1b, or (2) terminal 1a → diode circuit Da (first circuit Da1) → terminal 1b.

[0056] If the threshold voltage for one diode is 1.2V, then the threshold voltage of the first circuit Db1 will be 1.2V, and the threshold voltage of the first circuit Da1 will be 2.4V.

[0057] If the DC voltage V is less than 1.2V, the DC voltage V is below the threshold voltage of the first circuit Da1 and the first circuit Db1, so the DC current I is 0 amperes.

[0058] When the DC voltage V becomes 1.2V, the DC voltage V exceeds the threshold voltage of the first circuit Db1. Therefore, the DC current I begins to flow through the path (1) terminal 1a → resistor Ra → diode circuit Db (first circuit Db1) → terminal 1b.

[0059] When the DC voltage V is 1.2V or higher and less than 2.4V, the DC current I flows through resistor Ra and the first circuit Db1. However, the resistance of the diode is very small compared to the resistance of resistor Ra. Therefore, the DC current I increases approximately proportionally to the increase in DC voltage V (I = V / Ra).

[0060] When the DC voltage V reaches 2.4V, the DC voltage V exceeds the threshold voltage of the first circuit Da1. The resistance of the first circuit Da1 is much smaller than the resistance of resistor Ra. Therefore, the DC current I begins to flow not through path (1), but through path (2) terminal 1a → diode circuit Da (first circuit Da1) → terminal 1b. Because the resistance of the diode is very small, the DC current I increases sharply as the DC voltage V rises.

[0061] Next, we will explain the case where (B) capacitor Ca is short-circuited and capacitor Cb is not short-circuited (see line 302).

[0062] In case (B), the path through which the DC current I flows is (3) terminal 1a → capacitor Ca (short circuit) → diode circuit Db (first circuit Db1) → terminal 1b.

[0063] If the DC voltage V is less than 1.2V, the DC voltage V is below the threshold voltage of the first circuit Db1, so the DC current I is 0 amperes.

[0064] When the DC voltage V reaches 1.2V, the DC voltage V exceeds the threshold voltage of the first circuit Db1. Therefore, the DC current I begins to flow through the path (3) terminal 1a → capacitor Ca (short circuit) → diode circuit Db (first circuit Db1) → terminal 1b. Since the resistance of the diode is very small, the DC current I increases sharply as the DC voltage V rises.

[0065] Next, we will explain the case where capacitor Ca is not short-circuited and capacitor Cb is short-circuited (line 303).

[0066] In case (C), the path through which the DC current I flows is (4) terminal 1a → resistor Ra → capacitor Cb (short circuit) → terminal 1b, or (5) terminal 1a → diode circuit Da (first circuit Da1) → terminal 1b.

[0067] When the DC voltage V is less than 2.4V, the DC current I flows through path (4), i.e., through resistor Ra. Therefore, the DC current I increases in proportion to the increase in the DC voltage V (I = V / Ra).

[0068] When the DC voltage V reaches 2.4V, the DC voltage V exceeds the threshold voltage of the first circuit Da1. The resistance of the first circuit Da1 is much smaller than the resistance of resistor Ra. Therefore, the DC current I begins to flow not through path (4), but through path (5) terminal 1a → diode circuit Da (first circuit Da1) → terminal 1b. Because the resistance of the diode is very small, the DC current I increases sharply as the DC voltage V rises.

[0069] Thus, in cases (A), (B), and (C), when the same DC voltage V is applied to the electronic circuit 1, there is a difference in the DC current I that flows into the electronic circuit 1.

[0070] Therefore, for example, the control unit 203 sets the DC voltage V to a first DC voltage V1 that is 0 volts or more and less than 1.2V (for example, 0.5V (see line 311 in Figure 3)). The control unit 203 can then determine that case (C) is met if the difference between the first DC current I1 of the electronic circuit 1 under inspection and the first DC current I1 of a good electronic circuit 1 (hereinafter referred to as "first good current Iref1") is greater than or equal to a predetermined first threshold.

[0071] The first good current Iref1 can be measured in advance by applying the first DC voltage V1 to a good electronic circuit 1 prior to performing the inspection of the electronic circuit 1 to be inspected.

[0072] Furthermore, for example, the control unit 203 sets the DC voltage V to a second DC voltage V2 of 1.2V or higher (for example, 1.6V (see line 312 in Figure 3)). The control unit 203 can then determine that case (B) is met if the difference between the second DC current I2 of the electronic circuit 1 under inspection and the second DC current I2 of a good electronic circuit 1 (hereinafter referred to as "second good current Iref2") is greater than or equal to a predetermined second threshold.

[0073] The second good current Iref2 can be measured in advance by applying a second DC voltage V2 to a good electronic circuit 1 prior to performing the inspection on the electronic circuit 1 to be inspected.

[0074] Figure 4 is a flowchart of the fault detection method for an electronic circuit according to the first embodiment.

[0075] The control unit 203 outputs a control signal S1 to the variable constant voltage source 201 that causes it to output a first DC voltage V1 (for example, 0.5V). The variable constant voltage source 201 outputs the first DC voltage V1 to the electronic circuit 1 under test (step S100).

[0076] The current sensor 202 detects a first DC current I1 flowing into the electronic circuit 1 under inspection. The control unit 203 receives a detection signal S2 representing the first DC current I1 from the current sensor 202 (step S102).

[0077] The control unit 203 determines whether the difference between the first DC current I1 and the first good product current Iref1 is greater than or equal to a predetermined first threshold (step S104).

[0078] If the control unit 203 determines that the difference between the first DC current I1 and the first good current Iref1 is greater than or equal to the first threshold (step S104; Yes), it determines that the capacitor Cb of the electronic circuit 1 under inspection is short-circuited (step S106) and terminates the process.

[0079] If the control unit 203 determines that the difference between the first DC current I1 and the first good product current Iref1 is not greater than or equal to the first threshold (step S104; No), it outputs a control signal S1 to the variable constant voltage source 201 that causes it to output a second DC voltage V2 (for example, 1.6V). The variable constant voltage source 201 outputs the second DC voltage V2 to the electronic circuit 1 under inspection (step S108).

[0080] The current sensor 202 detects the second DC current I2 flowing into the electronic circuit 1 under inspection. The control unit 203 receives a detection signal S2 representing the second DC current I2 from the current sensor 202 (step S110).

[0081] The control unit 203 determines whether the difference between the second DC current I2 and the second good product current Iref2 is greater than or equal to a predetermined second threshold (step S112).

[0082] If the control unit 203 determines that the difference between the second DC current I2 and the second good current Iref2 is greater than or equal to the second threshold (step S112; Yes), it determines that the capacitor Ca of the electronic circuit 1 under inspection is short-circuit faulty (step S114) and terminates the process.

[0083] If the control unit 203 determines that the difference between the second DC current I2 and the second good current Iref2 is not greater than or equal to the second threshold (step S112; No), it determines that capacitor Ca of the electronic circuit 1 under inspection is not short-circuited and capacitor Cb is not short-circuited (step S116), and terminates the process.

[0084] (summary) (1) To detect a short-circuit fault in capacitor Ca or capacitor Cb, it is conceivable to provide pads on the semiconductor device 100 that are electrically connected to the other end of capacitor Ca and one end of capacitor Cb. However, in the semiconductor device 100, the size of the detection pads may be larger compared to circuit components such as capacitors, resistors, and diodes. Furthermore, a physical gap must be maintained between the pads on the substrate, especially when the pads are configured as bumps. Therefore, providing pads on the semiconductor device 100 that are electrically connected to the other end of capacitor Ca and one end of capacitor Cb will increase the size of the semiconductor device 100.

[0085] On the other hand, electronic circuit 1 can detect a short-circuit fault in capacitor Ca or capacitor Cb by including a resistor Ra, a diode circuit Da, and a diode circuit Db.

[0086] As a result, the electronic circuit 1 can detect a short-circuit fault in capacitor Ca or capacitor Cb while suppressing an increase in circuit size and area.

[0087] (2) AC sorting can be considered as a method for detecting short-circuit failures in capacitor Ca or capacitor Cb without providing pads on the semiconductor device 100. That is, an AC voltage can be applied to one end (terminal 1a) of capacitor Ca, and the voltage standing wave ratio (VSWR) can be compared with that of a good capacitor, or the gain can be compared with that of a good capacitor. In this case, it is easiest to perform this after mounting the semiconductor device 100 on a printed circuit board and assembling the module. However, if a short-circuit failure is found in capacitor Ca or capacitor Cb, the entire module will have to be discarded, leading to increased costs. Furthermore, AC sorting of the semiconductor device 100 alone is not easy due to the increased costs associated with introducing inspection equipment, as well as issues with measurement accuracy and stability.

[0088] On the other hand, the electronic circuit 1 can detect a short-circuit fault in capacitor Ca or capacitor Cb by applying a DC voltage V to terminal 1a.

[0089] As a result, compared to the AC sorting method described above, the electronic circuit 1 can suppress the increase in the cost of the inspection equipment and mitigate problems with measurement accuracy and stability.

[0090] <Second Embodiment> (composition) Figure 5 shows the configuration of the electronic circuit in the second embodiment.

[0091] In the second embodiment, the electronic circuit 1A is formed in the semiconductor device 100A, but the disclosure is not limited thereto.

[0092] Electronic circuit 1A includes capacitor Ca, capacitor Cb, capacitor Cc, resistor Ra, resistor Rb, diode circuit Da, diode circuit Db, diode circuit Dc, and inductor 101.

[0093] One end of the capacitor Ca is electrically connected to the terminal 1a. The other end of the capacitor Ca is electrically connected to one end of the capacitor Cb. The other end of the capacitor Cb is electrically connected to one end of the capacitor Cc. The other end of the capacitor Cc is electrically connected to one end of the inductor 101.

[0094] The other end of the inductor 101 is electrically connected to the terminal 1b. The terminal 1b is electrically connected to the reference potential. The inductor 101 is electromagnetically coupled to the inductor 102.

[0095] That is, the capacitors Ca, Cb, and Cc are connected in series between the terminals 1a and 1b.

[0096] The resistor Ra is electrically connected in parallel to the capacitor Ca. The resistor Rb is electrically connected in parallel to the capacitor Cb.

[0097] The relationship between the resistance value of the resistor Ra and the resistance value of the resistor Rb is set as Ra < Rb. In the present embodiment, the resistance value of the resistor Ra is 2.5 kΩ (kiloohm), and the resistance value of the resistor Rb is 5.0 kΩ, but the present disclosure is not limited thereto.

[0098] The diode circuit Da includes a first circuit Da1 and a second circuit Da2.

[0099] The first circuit Da1 includes three diodes connected in series. The first circuit Da1 has an anode electrically connected to one end of the capacitor Ca and a cathode electrically connected to the terminal 1b.

[0100] The second circuit Da2 includes three diodes connected in series. The second circuit Da2 has an anode electrically connected to the terminal 1b and a cathode electrically connected to one end of the capacitor Ca.

[0101] The first circuit Da1 and the second circuit Da2 are connected in inverse parallel.

[0102] In this embodiment, the number of diodes in the first circuit Da1 and the number of diodes in the second circuit Da2 are assumed to be the same, but this disclosure is not limited thereto. The number of diodes in the first circuit Da1 and the number of diodes in the second circuit Da2 may be different.

[0103] The first circuit Da1 conducts when the voltage between terminals 1a and 1b exceeds a threshold voltage, protecting other circuit components.

[0104] In this embodiment, the threshold voltage of the first circuit Da1 is the threshold voltage of three diodes. For example, if the threshold voltage of one diode is 1.0V, then the threshold voltage of three diodes is 3.0V.

[0105] The second circuit Da2 conducts when the voltage between terminal 1b and terminal 1a exceeds a threshold voltage, protecting other circuit components.

[0106] In this embodiment, the threshold voltage of the second circuit Da2 is the threshold voltage of three diodes, which is, for example, 3.0V.

[0107] The diode circuit Db includes a first circuit Db1 and a second circuit Db2.

[0108] The first circuit Db1 includes two diodes connected in series. The anode of the first circuit Db1 is electrically connected to one end of capacitor Cb, and the cathode is electrically connected to terminal 1b.

[0109] The second circuit Db2 includes two diodes connected in series. The anode of the second circuit Db2 is electrically connected to terminal 1b, and the cathode is electrically connected to one end of capacitor Cb.

[0110] The first circuit Db1 and the second circuit Db2 are connected in antiparallel.

[0111] In this embodiment, the number of diodes included in the first circuit Db1 and the number of diodes included in the second circuit Db2 are assumed to be the same, but this disclosure is not limited thereto. The number of diodes included in the first circuit Db1 and the number of diodes included in the second circuit Db2 may be different.

[0112] The first circuit Db1 conducts when the voltage between terminals 1a and 1b exceeds a threshold voltage, protecting other circuit components.

[0113] In this embodiment, the threshold voltage of the first circuit Db1 is the threshold voltage of two diodes. For example, if the threshold voltage of one diode is 1.0V, then the threshold voltage of two diodes is 2.0V.

[0114] The second circuit Db2 conducts when the voltage between terminals 1b and 1a exceeds a threshold voltage, protecting other circuit components.

[0115] In this embodiment, the threshold voltage of the second circuit Db2 is the threshold voltage of two diodes, which is, for example, 2.0V.

[0116] The diode circuit Dc includes a first circuit Dc1 and a second circuit Dc2.

[0117] The first circuit Dc1 includes one diode. The anode of the first circuit Dc1 is electrically connected to one end of capacitor Cc, and the cathode is electrically connected to terminal 1b.

[0118] The second circuit Dc2 includes one diode. The anode of the second circuit Dc2 is electrically connected to terminal 1b, and the cathode is electrically connected to one end of capacitor Cc.

[0119] The first circuit Dc1 and the second circuit Dc2 are connected in antiparallel.

[0120] In this embodiment, the number of diodes included in the first circuit Dc1 and the number of diodes included in the second circuit Dc2 are assumed to be the same, but this disclosure is not limited thereto. The number of diodes included in the first circuit Dc1 and the number of diodes included in the second circuit Dc2 may be different.

[0121] The first circuit Dc1 conducts when the voltage between one end of capacitor Cc and terminal 1b exceeds a threshold voltage, protecting other circuit components.

[0122] In this embodiment, the threshold voltage of the first circuit Dc1 is the threshold voltage of one diode, which is, for example, 1.0V.

[0123] The second circuit Dc2 conducts when the voltage between terminal 1b and one end of capacitor Cc exceeds a threshold voltage, protecting other circuit components.

[0124] In this embodiment, the threshold voltage of the second circuit Dc2 is the threshold voltage of one diode, which is, for example, 1.0V.

[0125] Electronic circuit 1A becomes an input circuit (e.g., an input matching circuit) when a high-frequency signal RFin is input to terminal 1a. Electronic circuit 1A becomes an output circuit (e.g., an output matching circuit) when a high-frequency signal RFout is output from terminal 1a.

[0126] Electronic circuit 1A, having capacitors Ca, Cb, and Cc connected in series, provides the following effects.

[0127] For example, let's assume that the capacitance values ​​of capacitors Ca, Cb, and Cc are the same. If the capacitance values ​​of capacitors Ca, Cb, and Cc are 3C0, then the combined capacitance of capacitors Ca, Cb, and Cc connected in series is C0.

[0128] In other words, capacitors Ca, Cb, and Cc connected in series are equivalent to a single capacitor with capacitance value C0 from the standpoint of impedance matching.

[0129] However, the capacitance values ​​of capacitors Ca, Cb, and Cc are all 3C0. In other words, compared to the case where electronic circuit 1A has only one capacitor with capacitance value C0, the capacitance values ​​of capacitors Ca, Cb, and Cc can be increased.

[0130] As a result, electronic circuit 1A can be made more resistant to electrostatic discharge (ESD) in various test models such as the charged device model (CDM).

[0131] (Fault detection method) This document describes a method for detecting short-circuit faults in capacitors Ca, Cb, and Cc.

[0132] When detecting short-circuit faults in capacitors Ca, Cb, and Cc, the fault detection device 200 (see Figure 2) described above is electrically connected to terminal 1a.

[0133] Figure 6 shows the relationship between the voltage applied to the electronic circuit of the second embodiment and the current flowing into it. In Figure 6, the horizontal axis represents the DC voltage V (volts) applied to the electronic circuit 1A, and the vertical axis represents the DC current I (microamperes) flowing into the electronic circuit 1A.

[0134] Line 321 shows the relationship between the DC voltage V and DC current I when (A) electronic circuit 1A is functioning correctly. Electronic circuit 1A is functioning correctly when none of capacitors Ca, Cb, and Cc are short-circuited.

[0135] Line 322 shows the relationship between the DC voltage V and the DC current I when capacitor Ca (B) is short-circuited, capacitor Cb is not short-circuited, and capacitor Cc is not short-circuited.

[0136] Line 323 shows the relationship between the DC voltage V and the DC current I when capacitor Ca (C) is not short-circuited, capacitor Cb is short-circuited, and capacitor Cc is not short-circuited.

[0137] Line 324 shows the relationship between the DC voltage V and the DC current I when capacitor Ca (D) is not short-circuited, capacitor Cb is not short-circuited, and capacitor Cc is short-circuited.

[0138] Lines 321, 322, 323, and 324 are all symmetrical with respect to the origin. Therefore, we will only explain the case where the DC voltage V is 0 volts or greater, and omit the explanation for the case where the DC voltage V is less than 0 volts.

[0139] First, we will explain the case where (A) electronic circuit 1A is a good product (see line 321).

[0140] In case (A), the path through which the DC current I flows is one of the following: (1) terminal 1a → resistor Ra → resistor Rb → diode circuit Dc (first circuit Dc1) → terminal 1b, (2) terminal 1a → resistor Ra → diode circuit Db (first circuit Db1) → terminal 1b, or (3) terminal 1a → diode circuit Da (first circuit Da1) → terminal 1b.

[0141] If the threshold voltage for one diode is 1.0V, then the threshold voltage of the first circuit Dc1 will be 1.0V, the threshold voltage of the first circuit Db1 will be 2.0V, and the threshold voltage of the first circuit Da1 will be 3.0V.

[0142] If the DC voltage V is less than 1.0V, the DC voltage V is below the threshold voltage of the first circuits Da1, Db1, and Dc1, so the DC current I is 0 amperes.

[0143] When the DC voltage V becomes 1.0V, the DC voltage V exceeds the threshold voltage of the first circuit Dc1. Therefore, the DC current I begins to flow through the path (1) terminal 1a → resistor Ra → resistor Rb → diode circuit Dc (first circuit Dc1) → terminal 1b.

[0144] When the DC voltage V is 1.0V or higher and less than 2.0V, the DC current I flows through resistors Ra and Rb and the first circuit Dc1. However, the resistance of the diode is very small compared to the resistances of resistors Ra and Rb. Therefore, the DC current I increases approximately proportionally to the increase in DC voltage V (I = V / (Ra + Rb)).

[0145] When the DC voltage V becomes 2.0V, the DC voltage V exceeds the threshold voltage of the first circuit Db1. The resistance of the first circuit Db1 is much smaller than the resistance of resistor Rb. Therefore, the DC current I begins to flow not through path (1), but through path (2) terminal 1a → resistor Ra → diode circuit Db (first circuit Db1) → terminal 1b.

[0146] When the DC voltage V is 2.0V or higher and less than 3.0V, the DC current I flows through resistor Ra and the first circuit Db1. However, the resistance of the diode is very small compared to the resistance of resistor Ra. Therefore, as the DC voltage V increases, the DC current I increases almost proportionally to the increase in DC voltage V (I = V / Ra).

[0147] When the DC voltage V reaches 3.0V, the DC voltage V exceeds the threshold voltage of the first circuit Da1. The resistance of the first circuit Da1 is much smaller than the resistances of resistors Ra and Rb. Therefore, the DC current I begins to flow not through path (2), but through path (3) terminal 1a → diode circuit Da (first circuit Da1) → terminal 1b. Because the resistance of the diode is very small, the DC current I increases sharply as the DC voltage V rises.

[0148] Next, we will explain the case where (B) capacitor Ca is short-circuited, capacitor Cb is not short-circuited, and capacitor Cc is not short-circuited (see line 322).

[0149] In case (B), the path through which the DC current I flows is either (4) terminal 1a → capacitor Ca (short circuit) → resistor Rb → diode circuit Dc (first circuit Dc1) → terminal 1b, or (5) terminal 1a → capacitor Ca (short circuit) → diode circuit Db (first circuit Db1) → terminal 1b.

[0150] If the DC voltage V is less than 1.0V, the DC voltage V is below the threshold voltage of the first circuit Db1 and the first circuit Dc1, so the DC current I is 0 amperes.

[0151] When the DC voltage V becomes 1.0V, the DC voltage V exceeds the threshold voltage of the first circuit Dc1. Therefore, the DC current I begins to flow through the path (4) terminal 1a → capacitor Ca (short circuit) → resistor Rb → diode circuit Dc (first circuit Dc1) → terminal 1b.

[0152] When the DC voltage V is 1.0V or higher and less than 2.0V, the DC current I flows through the resistor Rb and the first circuit Dc1. However, the resistance of the diode is very small compared to the resistance of resistor Rb. Therefore, the DC current I increases approximately proportionally to the increase in the DC voltage V (I = V / Rb).

[0153] When the DC voltage V becomes 2.0V, the DC voltage V exceeds the threshold voltage of the first circuit Db1. The resistance of the first circuit Db1 is much smaller than the resistance of resistor Rb. Therefore, the DC current I begins to flow not through path (4), but through path (5) terminal 1a → capacitor Ca (short circuit) → diode circuit Db (first circuit Db1) → terminal 1b.

[0154] When the DC voltage V is 2.0V or higher, the DC current I flows through the first circuit Db1. However, the resistance of the diode is very small. Therefore, the DC current I increases sharply as the DC voltage V rises.

[0155] Next, we will explain the case where capacitor Ca is not short-circuited, capacitor Cb is short-circuited, and capacitor Cc is not short-circuited (see line 323).

[0156] In case (C), the path through which the DC current I flows is (6) terminal 1a → resistor Ra → capacitor Cb (short circuit) → diode circuit Dc (first circuit Dc1) → terminal 1b.

[0157] If the DC voltage V is less than 1.0V, the DC voltage V is less than the threshold voltage of the first circuit Dc1, so the DC current I is 0 amperes.

[0158] When the DC voltage V becomes 1.0V, the DC voltage V exceeds the threshold voltage of the first circuit Dc1. Therefore, the DC current I begins to flow through the path (6) terminal 1a → resistor Ra → capacitor Cb (short circuit) → diode circuit Dc (first circuit Dc1) → terminal 1b.

[0159] When the DC voltage V is 1.0V or higher, the DC current I flows through the resistor Ra and the first circuit Dc1. However, the resistance of the diode is very small compared to the resistance of resistor Ra. Therefore, the DC current I increases approximately proportionally to the increase in the DC voltage V (I = V / Ra).

[0160] Next, we will explain the case where (D) capacitor Ca is not short-circuited, capacitor Cb is not short-circuited, and capacitor Cc is short-circuited (see line 324).

[0161] In case (D), the path through which the DC current I flows is either (7) terminal 1a → resistor Ra → resistor Rb → capacitor Cc (short circuit) → terminal 1b, or (8) terminal 1a → resistor Ra → diode circuit Db (first circuit Db1) → terminal 1b.

[0162] When the DC voltage V is less than 3.0V, the DC current I flows through the path (7) terminal 1a → resistor Ra → resistor Rb → capacitor Cc (short circuit) → terminal 1b.

[0163] When the DC voltage V is less than 3.0V, the DC current I flows through resistors Ra and Rb. Therefore, the DC current I increases in proportion to the increase in the DC voltage V (I = V / (Ra + Rb)).

[0164] When the DC voltage V becomes 3.0V, the DC voltage V exceeds the threshold voltage of the first circuit Db1. The resistance of the first circuit Db1 is much smaller than the resistance of resistor Rb. Therefore, the DC current I begins to flow not through path (7), but through path (8) terminal 1a → resistor Ra → diode circuit Db (first circuit Db1) → terminal 1b.

[0165] When the DC voltage V is 3.0V or higher, the DC current I flows through the resistor Ra and the first circuit Db1. However, the resistance of the diode is very small compared to the resistance of resistor Ra. Therefore, as the DC voltage V increases, the DC current I increases almost proportionally to the increase in DC voltage V (I = V / Ra).

[0166] Thus, in cases (A), (B), (C), and (D), when the same DC voltage V is applied to the electronic circuit 1, there is a difference in the DC current I that flows into the electronic circuit 1.

[0167] Therefore, for example, the control unit 203 sets the DC voltage V to a first DC voltage V1 that is 0 volts or more and less than 1.0V (for example, 0.5V (see line 331 in Figure 6)). The control unit 203 can then determine that case (D) is the case if the difference between the first DC current I1 of the electronic circuit 1 under inspection and the first DC current I1 of the good electronic circuit 1 (hereinafter referred to as "first good current Iref1") is greater than or equal to a predetermined first threshold.

[0168] Furthermore, for example, the control unit 203 sets the DC voltage V to a second DC voltage V2 between 2.0V and less than 3.0V (for example, 2.5V (see line 332 in Figure 6)). The control unit 203 can then determine that case (B) or (C) is met if the difference between the second DC current I2 of the electronic circuit 1 under inspection and the second DC current I2 of a good electronic circuit 1 (hereinafter referred to as "second good current Iref2") is greater than or equal to a predetermined second threshold.

[0169] Figure 7 is a flowchart of the fault detection method for an electronic circuit according to the second embodiment.

[0170] The control unit 203 outputs a control signal S1 to the variable constant voltage source 201 that causes it to output a first DC voltage V1 (for example, 0.5V). The variable constant voltage source 201 outputs the first DC voltage V1 to the electronic circuit 1A under test (step S200).

[0171] The current sensor 202 detects a first DC current I1 flowing into the electronic circuit 1A under inspection. The control unit 203 receives a detection signal S2 representing the first DC current I1 from the current sensor 202 (step S202).

[0172] The control unit 203 determines whether the difference between the first DC current I1 and the first good product current Iref1 is greater than or equal to a predetermined first threshold (step S204).

[0173] If the control unit 203 determines that the difference between the first DC current I1 and the first good current Iref1 is greater than or equal to the first threshold (step S204; Yes), it determines that the capacitor Cc of the electronic circuit 1A under inspection is short-circuited (step S206) and terminates the process.

[0174] If the control unit 203 determines that the difference between the first DC current I1 and the first good product current Iref1 is not greater than or equal to the first threshold (step S204; No), it outputs a control signal S1 to the variable constant voltage source 201 that causes it to output a second DC voltage V2 (for example, 2.5V). The variable constant voltage source 201 outputs the second DC voltage V2 to the electronic circuit 1A under inspection (step S208).

[0175] The current sensor 202 detects the second DC current I2 flowing into the electronic circuit 1A under inspection. The control unit 203 receives a detection signal S2 representing the second DC current I2 from the current sensor 202 (step S210).

[0176] The control unit 203 determines whether the difference between the second DC current I2 and the second good product current Iref2 is greater than or equal to a predetermined second threshold (step S212).

[0177] If the control unit 203 determines that the difference between the second DC current I2 and the second good current Iref2 is greater than or equal to the second threshold (step S212; Yes), it determines that capacitor Ca or capacitor Cb of the electronic circuit 1A under inspection is short-circuited (step S214) and terminates the process.

[0178] If the control unit 203 determines that the difference between the second DC current I2 and the second good current Iref2 is not greater than or equal to the second threshold (step S212; No), it determines that capacitor Ca of the electronic circuit 1A under inspection is not short-circuited, capacitor Cb is not short-circuited, and capacitor Cb is not short-circuited (step S216), and terminates the process.

[0179] (summary) (1) Even when capacitors Ca, Cb, and Cc are connected in series, electronic circuit 1A can detect short-circuit faults in capacitors Ca, Cb, or Cc without providing pads on semiconductor device 100A.

[0180] In other words, electronic circuit 1A, like electronic circuit 1, can detect short-circuit faults in capacitors Ca, Cb, or Cc while suppressing circuit and area increases.

[0181] (2) Even when capacitors Ca, Cb, and Cc are connected in series, electronic circuit 1A can detect a short-circuit fault in capacitor Ca, Cb, or Cc by applying a DC voltage V to terminal 1a.

[0182] In other words, electronic circuit 1A, like electronic circuit 1, can suppress the increase in the cost of the inspection equipment and suppress problems with the accuracy and stability of the measurement compared to AC sorting.

[0183] <Third Embodiment> In the flowcharts for the first embodiment (see Figure 4) and the second embodiment (see Figure 7), the case in which the number of times the DC voltage is output, the DC current is detected, and the difference between the detected current and the good current is compared with a threshold value is described twice, but this disclosure is not limited thereto. The number of times the DC voltage is output, the DC current is detected, and the difference between the detected current and the good current is compared with a threshold value may be once, or three or more times.

[0184] Furthermore, although the flowcharts of the first embodiment (see Figure 4) and the second embodiment (see Figure 7) do not use loops, loops may be used if desired.

[0185] In the third embodiment, a method for detecting faults in an electronic circuit based on the above will be described.

[0186] Figure 8 is a flowchart of the fault detection method for an electronic circuit according to the third embodiment.

[0187] The control unit 203 assigns 1 to variable n and 0 to variable flag (step S300).

[0188] The variable n is used to count the number of times the loop from step S302 to step S316, which will be described later, is executed. The variable flag, when set to 0, indicates that the loop from step S302 to step S316 will be repeated, and when assigned to 1, it indicates that the loop from step S302 to step S316 will terminate.

[0189] The control unit 203 outputs a control signal S1 to the variable constant voltage source 201 that causes it to output the nth DC voltage V(n). The variable constant voltage source 201 outputs the nth DC voltage V(n) to the electronic circuit 1 under inspection (step S302).

[0190] Step S302 corresponds to steps S100 and S108 (see Figure 4), and steps S200 and S208 (see Figure 7).

[0191] The current sensor 202 detects the nth DC current I(n) flowing into the electronic circuit under inspection. The control unit 203 receives a detection signal S2 representing the nth DC current I(n) from the current sensor 202 (step S304).

[0192] Step S304 corresponds to steps S102 and S110 (see Figure 4), and steps S202 and S210 (see Figure 7).

[0193] The control unit 203 determines whether the difference between the nth DC current I(n) and the nth threshold current Ith(n) is greater than or equal to a predetermined nth threshold (step S306).

[0194] The nth threshold current Ith(n) corresponds to the first good product current and the second good product current (see Figures 4 and 7).

[0195] Step S306 corresponds to steps S104 and S112 (see Figure 4), and steps S204 and S212 (see Figure 7).

[0196] If the control unit 203 determines that the difference between the nth DC current I(n) and the nth threshold current Ith(n) is greater than or equal to the nth threshold (step S306; Yes), it determines that the nth capacitor C(n) of the electronic circuit under inspection is short-circuit faulty (step S308) and terminates the process.

[0197] Step S308 corresponds to steps S106 and S114 (see Figure 4), and steps S206 and S214 (see Figure 7).

[0198] If the control unit 203 determines that the difference between the nth DC current I(n) and the nth threshold current Ith(n) is not greater than or equal to the nth threshold (step S306; No), it increments the variable n (step S310).

[0199] The control unit 203 determines whether the value of variable n is greater than or equal to a predetermined constant k (step S312).

[0200] The constant k is a constant that pre-determines the number of times the loop will be executed. For example, if the loop is to be executed once, the value of the constant k is set to 2 (=1+1). If the loop is to be executed twice, the value of the constant k is set to 3 (=2+1). If the loop is to be executed three times, the value of the constant k is set to 4 (=3+1).

[0201] If the control unit 203 determines that the value of variable n is greater than or equal to the constant k (step S312; Yes), it assigns 1 to the variable flag (step S314).

[0202] If the control unit 203 determines that the value of variable n is not greater than or equal to the constant k (step S312; No), or after executing step S314, it determines whether the value of variable flag is 1 (step S316).

[0203] If the control unit 203 determines that the value of the variable flag is not 1 (step S316; No), it proceeds to step S302.

[0204] If the control unit 203 determines that the value of the variable flag is 1 (step S316; Yes), it terminates the process.

[0205] (summary) The fault detection method for electronic circuits of the third embodiment can be adapted even when it is necessary to change the number of times the DC voltage output, DC current detection, and the difference between the detected current and the good current threshold are compared, simply by changing the value of the constant k. Therefore, the fault detection method for electronic circuits of the third embodiment can reduce the man-hours required to change the control program.

[0206] Furthermore, the fault detection method for the electronic circuit of the third embodiment can also handle cases where the number of capacitors connected in series (see capacitors Ca and Cb in Figure 1, and capacitors Ca, Cb, and Cc in Figure 5) increases.

[0207] <Other> In the embodiments described, the cases in which two capacitors are connected in series (first embodiment) and the cases in which three capacitors are connected in series (second embodiment) have been explained, but this disclosure is not limited to these. This disclosure can also be applied when four or more capacitors are connected in series. In that case, it is possible to detect a short-circuit fault in a capacitor by performing the fault detection method for the electronic circuit of the third embodiment (see flowchart in Figure 8).

[0208] <Example of the structure of this disclosure> This disclosure may also take the following form.

[0209] (1) Multiple capacitors connected in series, One or more resistors, A plurality of diode circuits, each including a first circuit containing one or more diodes connected in series, and a second circuit containing one or more diodes connected in series and connected in antiparallel to the first circuit, Includes, One end of one capacitor on one side of the plurality of capacitors is electrically connected to the first terminal, and the other end of one capacitor on the other side of the plurality of capacitors is electrically connected to the second terminal. The one or more resistors are electrically connected in parallel to each of the remaining capacitors among the plurality of capacitors, excluding one capacitor on the other side. One end of each of the plurality of diode circuits is electrically connected to one end of each of the plurality of capacitors, and the other end of each of the plurality of diode circuits is electrically connected to the second terminal. electronic circuit.

[0210] (2) The electronic circuit described in (1) above, The anodes of the first circuit of the plurality of diode circuits are electrically connected to one end of the plurality of capacitors, The number of diodes included in each of the aforementioned plurality of diode circuits is different. electronic circuit.

[0211] (3) The electronic circuit described in (2) above, The number of diodes included in each of the plurality of diode circuits, the first circuit, increases as you move from the other side to the first side. electronic circuit.

[0212] (4) An electronic circuit described in any one of (1) to (3) above, The resistance values ​​of each of the aforementioned resistors are different. electronic circuit.

[0213] (5) The electronic circuit described in (4) above, The resistance values ​​of each of the aforementioned plurality of resistors increase as you move from one side to the other side. electronic circuit.

[0214] (6) A method for detecting an electronic circuit fault as described in any one of (1) to (5) above, A predetermined voltage is applied to the first terminal, The current flowing into the first terminal is detected, The presence or absence of a short-circuit fault in the plurality of capacitors is detected by comparing the current flowing into the first terminal with the current flowing into the first terminal when the voltage is applied to a good electronic circuit. A method for detecting faults in electronic circuits.

[0215] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. The present invention may be modified or improved without departing from its spirit, and equivalents thereof are also included. [Explanation of symbols]

[0216] 1, 1A electronic circuit 100, 100A semiconductor equipment 200 Fault detection device 201 Variable Constant Voltage Source 202 Current Sensor 203 Control Unit Ca, Cb, Cc capacitors Da, Db, Dc diode circuit Da1, Db1, Dc1 1st circuit Da2, Db2, Dc2 2nd circuit Ra, Rb resistance

Claims

1. Multiple capacitors connected in series, One or more resistors, A plurality of diode circuits, each including a first circuit containing one or a plurality of diodes connected in series, and a second circuit containing one or a plurality of diodes connected in series and connected in antiparallel to the first circuit, Includes, One end of one capacitor on one side of the plurality of capacitors is electrically connected to the first terminal, and the other end of one capacitor on the other side of the plurality of capacitors is electrically connected to the second terminal. The one or more resistors are electrically connected in parallel to the remaining capacitors of the plurality of capacitors, excluding the one capacitor on the other side. One end of each of the plurality of diode circuits is electrically connected to one end of each of the plurality of capacitors, and the other end of each of the plurality of diode circuits is electrically connected to the second terminal. electronic circuit.

2. The electronic circuit according to claim 1, The anodes of the first circuit of the plurality of diode circuits are electrically connected to one end of the plurality of capacitors, The number of diodes included in each of the aforementioned plurality of diode circuits is different. electronic circuit.

3. The electronic circuit according to claim 2, The number of diodes included in each of the plurality of diode circuits, the first circuit, increases as you move from the other side to the first side. electronic circuit.

4. The electronic circuit according to claim 1, The resistance values ​​of each of the aforementioned resistors are different. electronic circuit.

5. The electronic circuit according to claim 4, The resistance values ​​of each of the aforementioned plurality of resistors increase as you move from one side to the other side. electronic circuit.

6. A method for detecting faults in an electronic circuit according to claim 1, A predetermined voltage is applied to the first terminal at least once. The current flowing into the first terminal is detected at least once, The presence or absence of a short-circuit fault in the plurality of capacitors is detected by comparing the current flowing into the first terminal with the current flowing into the first terminal at least once when the voltage is applied to a good electronic circuit. A method for detecting faults in electronic circuits.

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