JP2014178177A - Prediction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a prediction apparatus capable of predicting a degree of advance of a deterioration range of a substrate.SOLUTION: A plurality of conductor patterns are formed on a substrate 17. Each conductor pattern has an input terminal and an output terminal. An inspection signal is inputted to the input terminal of any one of the plurality of conductor patterns. Output terminals of the plurality of conductor patterns respectively output signals. A degree of advance of the deterioration range of the substrate can be predicted on the basis of respective signals received from the output terminals of the plurality of conductor patterns.

Description

  The present invention relates to a prediction device that predicts deterioration of a printed circuit board.

  In recent years, the interval between wirings on a printed circuit board is becoming narrower in electronic devices as components are miniaturized and circuits are highly integrated. In the printed circuit board, when the wiring interval is narrowed, the metal used as the wiring is ionized, and ion migration of the ionized metal on the insulator or the interface reduces the surface resistance value of the wiring. Insulation resistance value decreases. There is a risk that the electronic device may fail if the wiring on the printed circuit board is short-circuited. In view of this, a technique has been developed in which deterioration of insulation between wirings on a printed circuit board is detected to predict the replacement time of the printed circuit board.

  For example, a test pattern including a pair of comb-shaped electrodes facing each other is provided on a printed circuit board, and insulation deterioration between wirings on the printed circuit board is caused based on a change in current flowing in the test pattern due to a voltage applied between the electrodes A technique for detection is known (see, for example, Patent Document 1).

JP 2011-253849 A

  However, in the conventional technique, since a decrease in the insulation resistance value between the pair of electrodes and a short circuit between the pair of electrodes are detected, there is a problem that it is not known whether or not the range in which ion migration occurs is expanded.

  An object of the prediction device of the present disclosure is to provide a technique capable of detecting a range in which ion migration occurs and predicting deterioration of a printed circuit board.

  According to one aspect, the prediction device includes a plurality of conductor patterns on the substrate, and an input unit that inputs a signal encoded to any one of the input terminals of the plurality of conductor patterns. The receiving means receives the signals individually from the output terminals of all the conductor patterns including the conductor pattern to which the signals are input, and the total number of codes that are the values of the signals input by the input means. The first information regarding the code error rate, which is the ratio of the number of error codes in the signal, and whether or not conduction is established between the output terminals of all conductor patterns with respect to the input terminals of the conductor pattern to which signals are input. And prediction means for predicting a range in which the substrate deteriorates based on the two information.

  The prediction device of the present invention can detect the range in which ion migration proceeds and predict deterioration of the printed circuit board.

1 is a diagram illustrating an embodiment of a monitoring system. It is a figure which shows an example of the low-order side communication apparatus shown in FIG. It is a figure which shows the example of the board | substrate which the low-order side communication apparatus shown in FIG. 2 has. It is a figure which shows the example of the prediction circuit shown in FIG. It is a figure which shows the example of the determination pattern shown in FIG. FIG. 6 is a diagram illustrating an example of a through via illustrated in FIG. 5. It is a figure which shows the example which ion migration has progressed to a part of conductor pattern. It is a figure which shows the example which the ion migration advances and between the some conductor patterns is short-circuited. It is a figure which shows the example which the ion migration is advancing on the inner surface of a penetration via. It is a figure which shows the procedure of the operation | movement in which a control part estimates the replacement time of a board | substrate. It is a figure which shows the procedure of the operation | movement which the control part 31 performs determination of whether to perform avoidance operation | movement. It is a figure which shows the example of the information of the signal which the receiving part received when the ion migration has not arisen. It is a figure which shows the example of the information of the signal which the receiving part received when the ion migration has arisen. It is a figure which shows the other example which changed the information of the signal which the receiving part received with respect to the example shown in FIG.

Hereinafter, embodiments will be described with reference to the drawings.
FIG. 1 illustrates one embodiment of a monitoring system. The monitoring system 10 of this embodiment includes a monitoring device 11, a network 12, a plurality of repeaters 13 (13a, 13b), and a plurality of computer devices 15 (15a, 15b, ..., 15c). The plurality of computer devices 15 are respectively installed in user homes used in areas A, B, and C near the coast, for example. The monitoring device 11 and the computer device 15 each have a communication function for communicating data with each other. The computer device 15 has a printed circuit board having a wiring pattern. The monitoring device 11 monitors the replacement time (remaining life) of the printed circuit board of the computer device 15. The monitoring device 11 receives information on the deterioration of the printed circuit board obtained from the computer device 15 and information on the replacement timing of the printed circuit board, and notifies the administrator of the information to that effect.

  FIG. 2 shows an example of the computer device 15 shown in FIG. The computer device 15 includes a substrate 17, an intake fan 18, an exhaust fan 19, a heater 20, and a box 21. The box 21 houses the substrate 17, the intake fan 18, the exhaust fan 19, and the heater 20, and has a door 22 that can be opened and closed to replace the substrate 17. The intake fan 18 is provided on one inner wall 23 sandwiching the substrate 17 in the box 21. The exhaust fan 19 is provided on the other inner wall 23 with the substrate 17 interposed therebetween. The ventilation holes of the intake fan 18 and the exhaust fan 19 have a filter for preventing dust, sea salt particles, and the like from entering the box 21.

  The intake fan 18 blows outside air into the box 21. The exhaust fan 19 exhausts the air inside the box 21 to the outside. The heater places the inside of the box 21 in a high temperature environment. The intake fan 18, the exhaust fan 19, and the heater 20 are an example of means for reducing the relative humidity inside the box 21.

  FIG. 3 shows an example of a printed circuit board (hereinafter referred to as “substrate”) 17 mounted on the computer 15a shown in FIG. The substrate 17 includes a communication circuit 25 for performing communication with the monitoring device 11 and a prediction circuit 26 for predicting the degree of progress of ion migration. Note that the position where the prediction circuit 26 is wired may be any position such as the center of one surface of the substrate 17 or any one of the four corners. A plurality of prediction circuits 26 may be mounted on the substrate 17. Further, the prediction circuit 26 may be mounted on a board different from the board 17.

  FIG. 4 shows an example of the prediction circuit 26 shown in FIG. The prediction circuit 26 includes a determination pattern 28, an input unit 29, a reception unit 30, a control unit 31, a storage unit 32, and drivers 33 and 34. The input unit 29 is an example of an input unit, and the receiving unit 30 is an example of a receiving unit. Furthermore, the control unit 31 is an example of a prediction unit, and the storage unit 32 is an example of a storage unit.

  The determination pattern 28 includes a plurality of conductor patterns for predicting the degree of progress of a range in which ion migration occurs. The input unit 29 inputs an inspection signal to the determination pattern 28 in synchronization with the synchronization signal supplied from the control unit 31. The receiving unit 30 receives a test signal from the input unit 29 via the determination pattern 28. The control unit 31 controls the input unit 29 and the receiving unit 30 respectively, and predicts the degree of progress of the range in which the substrate 17 deteriorates based on the information of the signal received by the receiving unit 30.

  In addition, the control unit 31 includes a determination unit 35 that determines whether to perform an avoidance operation for avoiding a short circuit between the wires due to the progress of ion migration based on the predicted result. The determination unit 35 determines whether to notify the monitoring device 11 illustrated in FIG. 1 of the replacement time of the substrate 17 based on the result predicted by the control unit 31. The control unit 31 writes information on the signal received by the reception unit 30 in the storage unit 32.

  When the determination unit 35 determines that the avoidance operation is performed, the control unit 31 controls the drivers 33 and 34 to drive the intake fan 18, the exhaust fan 19, and the heater 20. The avoidance operation has a first mode that is executed at the beginning of the process of predicting the replacement time of the substrate 17 and a second mode that is executed at the end of the process of predicting the replacement time of the substrate 18. In the first mode, the intake fan 18, the exhaust fan 19, and the heater 20 are driven to raise the inside of the box 21 to a high temperature and improve the air permeability. In the second mode, the intake fan 18 and the exhaust fan 19 are stopped and the heater 20 is driven to bring the inside of the box 21 into a high temperature environment.

  FIG. 5 shows an example of the determination pattern 28 shown in FIG. The determination pattern 28 has a plurality of wiring patterns 37 (37a, 37b, 37c, 37d) wired on the substrate 17 and a plurality of through vias 38 (38a, 38b, 38c, 38d). The plurality of wiring patterns 37 and 38 are wired on one surface of the outer layer of the substrate 17 with a conductor (copper foil or the like) at a predetermined interval. Each wiring pattern 37 is wired in, for example, a “<” shape, and has bent portions 39, 40, 41, 42 at the substantially bent center. Each wiring pattern 37 includes an input terminal 43 (43a, 43b, 43c, 43d) to which an inspection signal is input from the input unit 29, and an output terminal 44 (44a, 44b, 44c, to which a measurement signal is output. 44d).

  For example, the substrate 17 is a multilayer substrate having a plurality of wiring layers. The plurality of through vias 38 connect the inner layer and the outer layer of the multilayer substrate 17 through holes. Each through via 38 is disposed, for example, between the bent portions 39-42 of the wiring pattern 37.

  Each through via 38 is connected to an input terminal 45 (45 a, 45 b, 45 c, 45 d) that receives an inspection signal from the input unit 29 by a conductor pattern that is provided on the inner layer of the substrate 17. In addition, each through via 38 is connected to an output terminal 46 (46 a, 46 b, 46 c, 46 d) that outputs a test signal to the receiving unit 30 by a conductor pattern that is provided in the inner layer of the substrate 17. The input terminal 45 and the output terminal 46 are provided at the upper end of the non-through via 53, for example.

  The wiring pattern 37 and the through via 38 are examples of a conduction pattern. Further, for example, the determination pattern 28 is made of the same material, the same interval, and the same thickness as those of the conductor pattern such as the wiring pattern and the through via included in the communication circuit 25. In the example shown in FIG. 5, the number of wiring patterns 37 and through vias 38 is described as four, but the number of wiring patterns and through vias is not limited. Further, the number of wiring patterns 37 and through vias 38 may not be the same.

  FIG. 6 shows an example of the through via 38a shown in FIG. In the example shown in FIG. 6, the substrate 17 is a four-layer substrate, and the through via 38 a includes the first layer 47, the second layer 48, the third layer 49, and the fourth layer 50 in which the wiring pattern 37 is disposed. It penetrates and is exposed on the front and back surfaces of the substrate 17. For example, the inner layer land 51 of the third layer 49 provided in the through via 38a is connected to the inner layer pattern 52 that is a conductor such as a copper foil. One of the inner layer patterns 52 is connected to the inner layer land 54 of the non-through via 53, and the other is connected to the via 56 of the non-through via 55. A land provided on the upper end of the non-through via 53 (for example, the surface of the substrate 17) functions as an input terminal 45a to which a signal for inspection is input. The land provided at the upper end of the non-through via 55 functions as an output terminal 46a that outputs a signal for inspection.

  FIG. 7 shows an example in which the ion migration 57 proceeds to a part of the second wiring pattern 37b. Ion migration is a phenomenon in which metal used as a wiring pattern or via is ionized by moisture including seawater or moisture adhering to the substrate 17, and the ionized metal is deposited on an insulator or on an interface. The ion migration 57 may reduce the surface resistivity of the second wiring pattern 37b and reduce the signal level of the second wiring pattern 37b. Therefore, the input unit 29 uses, for example, a high-frequency signal (hereinafter referred to as “signal”) in which the amplitude of an arbitrary information signal is encoded with a series of pulse signals as an inspection signal to the input terminal 43b of the wiring pattern 37b. input. Then, the receiving unit 30 measures the value of the signal received from the output terminal 44b. The control unit 31 calculates a code error rate that is a ratio of the number of codes of the signal erroneously measured by the receiving unit 30 to the total number of codes that is the value of the signal measured by the receiving unit 30. When the information on the code error rate calculated this time increases as compared with the information on the previous code error rate, the determination unit 35 determines that the range in which ion migration occurs is expanded.

  FIG. 8 shows an example in which the ion migration 58 has progressed and the wiring patterns 37a and 37b are short-circuited. The input unit 29 inputs a signal to the input terminal 43a of the first wiring pattern 37a. The receiving unit 30 receives a signal output from each output terminal 44. In this example, signals received from the output terminals 44a and 44b are measured, and no signals are measured from the other output terminals 44c and 44d. Thereby, the determination unit 35 determines that the first wiring pattern 37a and the second wiring pattern 37b are short-circuited. The determination unit 35 determines that the range in which ion migration occurs is expanded when the number of short-circuited points measured this time increases as compared to the number of short-circuited points measured last time.

  FIG. 9 shows an example in which the ion migration 59 proceeds inside the hole of the through via 38a. In the through via 38a, the surface resistance of the via is lowered due to the progress of ion migration, and the signal level may be lowered. As described above with reference to FIG. 7, the input unit 29 inputs the encoded high-frequency signal to the input terminal 45a of the through via 38a as described above. The receiving unit 30 measures the value of the signal received at the output terminal 46. The control unit 31 calculates a code error rate that is a ratio of the number of codes of the signal erroneously measured by the receiving unit 30 to the total number of codes that is the value of the received signal. When the information on the code error rate calculated this time is increased as compared with the information on the code error rate calculated last time, the determination unit 35 determines that the range in which ion migration occurs is expanded.

FIG. 10 shows an operation procedure in which the control unit 31 predicts the replacement time of the substrate 17.
In step S1 shown in FIG. 10, the control unit 31 controls the input unit 29 to input an inspection signal to the input terminal 43a of the first wiring pattern 37a.
In step S <b> 2, the control unit 31 controls the receiving unit 30 to measure the value of the signal received from each output terminal 44 of the wiring pattern 37 and each output terminal 46 of the through via 38.

  In step S <b> 3, the determination unit 35 compares the signal information received from the output terminals 44 and 46 with the information of the signal received last time read from the storage unit 32, and the extent to which the range in which ion migration occurs progresses. Determine. And the determination part 35 determines whether the avoidance operation | movement for avoiding that the range which ion migration advances advances according to the determined result.

  Thereby, the control unit 31 performs the avoidance operation based on the prediction of the degree of progress of the ion migration range centered on the first wiring pattern 37a and the prediction of the degree of progress of the ion migration range. Or not.

Next, in step S4, the control unit 31 controls the input unit 29 to input a signal to the input terminal 45a of the first through via 38a.
In step S <b> 5, the receiving unit 30 measures the value of the signal received at each output terminal 44 of the wiring pattern 37 and each output terminal 46 of the through via 38.

  In step S <b> 6, the determination unit 35 compares the signal value information received at the output terminals 44 and 46 with the previously received signal value information read from the storage unit 32, and a range in which ion migration occurs. Determine the degree of progress. And the determination part 35 determines whether the avoidance operation | movement for avoiding that the range which ion migration produces expands according to the determined result is performed.

  Thereby, the control unit 31 performs the avoidance operation based on the prediction of the degree of progress of the ion migration range centering on the first through via 38a and the prediction of the degree of progress of the ion migration range. The determination process of whether or not to complete is completed.

Next, in step S7, the control unit 31 controls the input unit 29 to input a signal to the input terminal 43b of the second wiring pattern 37b.
In step S <b> 8, the receiving unit 30 measures the value of the signal received at each output terminal 44 of the wiring pattern 37 and each output terminal 46 of the through via 38.

  In step S <b> 9, the determination unit 35 compares the signal value information received at the output terminals 44 and 46 with the previous signal value information read from the storage unit 32, and a range in which ion migration occurs. Determine the degree of progress. And the determination part 35 determines whether the avoidance operation | movement for avoiding that the range which ion migration advances and expands according to the determined result is performed.

  Thereby, the control unit 31 performs the avoidance operation based on the prediction of the degree of progress of the ion migration range around the second wiring pattern 37b and the prediction of the degree of progress of the ion migration range. The determination process of no is completed.

  Thereafter, the control unit 31 connects the input terminals 43 and 45 of the second through via 38b, the third wiring pattern 37c, the third through via 38c, the fourth wiring pattern 37d, and the fourth through via 38d. Input inspection signals in time series. Then, each time a signal is input to the input terminals 43 and 45, the determination unit 35 measures the value of the signal received from the output terminals 44 and 46 substantially simultaneously. Then, the determination unit 35 compares the information on the value of the measured signal with the information on the value of the signal measured last time, and predicts the degree of progress of the ion migration range to execute the avoidance operation. Determine whether.

In step S10, finally, the control unit 31 controls the input unit 29 to input a signal to the input terminal 45d of the fourth through via 38d.
In step S <b> 11, the receiving unit 30 measures the value of the signal received at each output terminal 44 of the wiring pattern 37 and each output terminal 46 of the through via 38.

  In step S <b> 12, the determination unit 35 compares the signal value information received at the output terminals 44 and 46 with the previously received signal value information read from the storage unit 32, and a range in which ion migration occurs is determined. Determine the degree of progress. Then, the determination unit 35 determines whether to perform the avoidance operation according to the determination result.

  As a result, the control unit 31 completes the prediction of the degree to which the range in which ion migration centering on the fourth through via 38d is advanced and the determination process for determining whether to perform the avoidance operation. As described above, the control unit 31 executes a process of inputting a signal to all the input terminals 43 and 45 to determine whether or not the avoidance operation can be performed as one cycle, and again executes the process at intervals of a predetermined period.

  The order in which the inspection signals are input to the input terminals 43 and 45 is not limited to the order described above, and any order may be used.

  FIG. 11 shows an operation procedure in which the control unit 31 determines whether or not to perform the avoidance operation. In step S <b> 13 shown in FIG. 11, the control unit 31 controls the input unit 29 to input inspection signals in time series to the input terminals 43 and 45 as shown in FIG. 11. .

  In step S <b> 14, the receiving unit 30 measures the value of the signal received at each of the output terminals 44 and 46, and sends information on the measured signal value to the control unit 31. The control unit 31 stores information on the value of the signal received from the reception unit 30 in the storage unit 32.

  In step S <b> 15, the determination unit 35 reads information on the value of the signal stored last time from the storage unit 32. Then, the determination unit 35 compares the read information on the value of the previous signal with the information on the value of the signal measured this time, and the range in which the wiring patterns 37 or the wiring pattern 37 and the through via 38 are short-circuited. It is determined whether or not is larger than the previous time. As a result of the comparison, if the determination unit 35 determines that the range to be short-circuited is enlarged, the determination unit 35 proceeds to the process of step S18. Moreover, the determination part 35 makes it transfer to the process of step S16, when it determines with the range which short-circuits has not expanded (it improved). If the determination unit 35 determines that the short-circuit range does not change from the previous time, the determination unit 35 causes the process to proceed to step S <b> 16 as in the case where it is determined that the short-circuit range has not expanded.

  In step S <b> 16, the control unit 31 divides the number of error codes, which are signal values erroneously measured by the reception unit 30, by the total number of codes, which are signal values input from the input unit 29, to generate a code error rate. Is calculated.

  In step S17, the determination unit 35 reads information on the code error rate stored last time from the storage unit 32, compares the information on the previous code error rate with the information on the current code error rate, and determines the code error rate. Determine whether it has increased. When determining that the code error rate has increased, the determination unit 35 proceeds to the process of step S18. When determining that the code error rate has not increased, the determination unit 35 performs the process of step S13 of inputting a signal to the next output terminal. Transition. Note that when determining that the comparison results are the same, the determination unit 35 causes the process to proceed to step S13 as in the case of determining that the comparison result has not increased.

  In step S18, the control unit 31 determines whether or not to perform the avoidance operation in the first mode. If the avoidance operation in the first mode is not executed, the process proceeds to step S19. If the avoidance operation in the first mode is executed, the process proceeds to step S20.

  In step S19, when the control unit 31 determines that an increase in the range in which the determination pattern 28 is short-circuited and an increase in the code error rate are recognized, the first mode for driving the intake fan 18, the exhaust fan 19, and the heater 20 is performed. Execute the avoidance action.

  In step S20, the control unit 31 determines whether or not the second mode avoidance operation is being performed. When the avoidance operation in the second mode is not executed, the control unit 31 proceeds to the process of step S21, and when the avoidance operation in the second mode is performed, the control unit 31 proceeds to the process of step S22. .

  In step S <b> 21, the control unit 31 stops the intake fan 18 and the exhaust fan 19, and executes a second mode avoidance operation for driving the heater 20. Then, the control part 31 transfers a process to operation | movement of step S23.

  In step S <b> 22, the control unit 31 stores information indicating that the board 17 is to be replaced, for example, in a monitoring frame and sends the information to the monitoring device 11. Thereafter, the control unit 31 shifts the processing to the operation of step S23.

  In step S <b> 23, the control unit 31 determines whether or not inspection signals have been input to all the input terminals 43 and 45. If input terminals 43 and 45 to which no inspection signal has been input still remain, the process proceeds to step S13. When inspection signals are input to all the input terminals 43 and 45, the control unit 31 determines whether to perform an avoidance operation and determines whether it is time to replace the substrate 17. End. In addition, the control part 31 makes the process which inputs the signal for a test | inspection into all the input terminals 43 and 45, and determines the propriety of execution of avoidance operation | movement as 1 cycle, and passes the predetermined period for this 1 cycle process. This is executed every time to prevent a failure of the computer device 15.

  FIG. 12 is a diagram illustrating an example of signal information received by the receiving unit 30 when no ion migration occurs. In the table, “◯” represents conduction and “x” represents non-conduction. In this table, “column” represents a column in the table. For example, in the example on the left side of the table, information on signals measured at the output terminals 44 and 46 when a signal is input to the input terminal 43a of the first wiring pattern 37a is described. For example, in the example illustrated in FIG. 12, the wiring pattern 37 and the through via 38 to which a signal is input are conducted, and the wiring pattern 37 and the wiring pattern 37 other than the through via 38 to which a signal is input are electrically connected. Is not allowed. In the example shown in FIG. 12, the signal level of the wiring pattern 37 and the through via 38 to which a signal is input is not reduced.

  FIG. 13 is a diagram illustrating an example of signal information received by the receiving unit 30 when ion migration occurs. In the table shown in FIG. 13, “◯” represents conduction and “x” represents non-conduction.

  For example, in the example shown in FIG. 13, when the input unit 29 inputs a signal to the input terminal 43a of the first wiring pattern 37a, the determination unit 35 receives the first through via 38a, the second wiring pattern 37b, and It is determined that the second through via 38b is conductive. Further, when the determination unit 35 inputs a signal to the input terminal 45a of the first through via 38a, the first wiring pattern 37a, the second wiring pattern 37b, and the second through via 38b are conductive. It is judged. Further, when the determination unit 35 inputs a signal to the input terminal 43b of the second wiring pattern 37b, the first wiring pattern 37a, the first through via 38a, and the second through via 38b are conductive. It is determined. Furthermore, when the determination unit 35 inputs a signal to the input terminal 45b of the second through via 38b, the first wiring pattern 37a, the first through via 38a, and the second wiring pattern 37b are conductive. It is determined.

  The determination unit 35 determines that the fourth wiring pattern 37d is conductive when a signal is input to the input terminal 45c of the third through via 38c. Furthermore, the determination unit 35 determines that the third through via 38c is conductive when a signal is input to the input terminal 43d of the fourth wiring pattern 37d.

  The determination unit 35 predicts the degree of progress of the deterioration of the substrate 17 every time a signal is input by changing the input terminals 43 and 45, and performs an avoidance operation to avoid the expansion of the range in which ion migration occurs. Determine whether or not.

  For example, the control unit 31 determines the number of the wiring patterns 37 and 38 that are conductive when a signal is input to the input terminal 43a of the first wiring pattern 37a and the number of the wiring patterns 37 and 38 measured in the example illustrated in FIG. Compare with the number. And the control part 31 performs the avoidance operation | movement of a 1st mode, since the location 60 determined to conduct | electrically_connect with respect to the 1st penetration via 38a is increasing.

  Next, for example, when the control unit 31 inputs a signal to the input terminal 45a of the first through via 38a, the location 61 where the first wiring pattern 37a conducts is measured in the example shown in FIG. Since the number of the wiring patterns 37 and 38 is increased as compared with the conductive portion, the avoidance operation in the second mode is executed. Thereafter, when the control unit 31 inputs a signal to the input terminal 43b of the second wiring pattern 37b, the portion 62 that conducts to the first wiring pattern 37a is the previous wiring pattern 37 measured in the example shown in FIG. , 38 is increased in comparison with the conducting portion. At this time, since the control unit 31 is performing the avoidance operation in the second mode, the control unit 31 transmits information notifying that the board 17 is to be replaced to the monitoring device 11.

  FIG. 14 shows another example in which the information of the signal measured by the receiving unit 30 is changed from the example shown in FIG. In the table shown in FIG. 14, “◯” indicates conduction, “×” indicates non-conduction, and “▲” indicates an increase in the code error rate.

  For example, in the example illustrated in FIG. 14, the determination unit 35 outputs a signal output from the output terminal 44a of the first wiring pattern 37a when the input unit 29 inputs a signal to the input terminal 43a of the first wiring pattern 37a. The code error rate is calculated based on the value of. Then, the determination unit 35 determines that the calculated code error rate information has increased compared to the previous code error rate information, which is an example illustrated in FIG.

  The determination unit 35 calculates a code error rate calculated based on a signal received at the output terminal 44c of the third wiring pattern 37c when the input unit 29 inputs a signal to the input terminal 43c of the third wiring pattern 37c. Is calculated. Then, the determination unit 35 determines that the calculated code error rate information has increased compared to the previous code error rate information, which is an example illustrated in FIG. Further, the determination unit 35 determines that the third through via 38c is conductive when a signal is input to the input terminal 43c of the third wiring pattern 37c.

  The determination unit 35 determines that the third wiring pattern 37c is conductive when a signal is input to the input terminal 45c of the third through via 38c. Further, the determination unit 35 calculates a code error rate calculated based on a signal received at the output terminal 46c of the third through via 38c when the input unit 29 inputs a signal to the input terminal 45c of the third through via 38c. Is calculated. Then, the determination unit 35 determines that the calculated code error rate information has increased compared to the previous code error rate information, which is an example illustrated in FIG. Furthermore, the determination unit 35 determines that the fourth wiring pattern 37d is conductive when a signal is input to the input terminal 45c of the third through via 38c.

  The determination unit 35 determines that the third through via 38c is conductive when a signal is input to the input terminal 43d of the fourth wiring pattern 37d. Further, when the input unit 29 inputs a signal to the fourth wiring pattern 37d, the determination unit 35 calculates a code error rate calculated based on the information of the signal received at the output terminal 44d of the fourth wiring pattern 37d. To do. Then, the determination unit 35 determines that the calculated code error rate information has increased compared to the previous code error rate information, which is an example illustrated in FIG.

  As shown in the left column of the table in FIG. 14, the determination unit 35 has a portion 64 where the code error rate increases when a signal is input to the first wiring pattern 37 a in the previous example shown in FIG. 12. Therefore, the avoidance operation of the first mode is executed. Next, when the control unit 31 inputs a signal to the third wiring pattern 37c, the portion 65 where the information on the code error rate increases is compared with the information on the previous code error rate shown in FIG. Since it has increased, the avoidance operation in the second mode is executed. Then, in the control unit 31, when a signal is input to the third through via 38c, the number of locations 66 that conduct to the third wiring pattern 37c is increased compared to the example illustrated in FIG. At this time, since the control unit 31 is performing the avoidance operation in the second mode, the control unit 31 transmits information notifying that the board 17 is to be replaced to the monitoring device 11.

  The determination unit 35 predicts every time a signal is input to the input terminals 43 and 45, but instead receives all signals from the output terminals 44 and 46 as shown in FIGS. Therefore, the degree of progress in the range where ion migration occurs may be predicted.

  Further, the determination unit 35 may determine that the determination pattern 28 is broken when the code error rate calculated based on the information on the values of the signals received from the output terminals 44 and 46 exceeds a threshold value. According to this, the reliability of the degree of progress in the range where ion migration occurs is improved.

  The interval between the determination patterns 28 is determined according to the potential of the input signal. Therefore, the input unit 29 may input a signal having a potential higher than the potential corresponding to the interval between the determination patterns 28 to the input terminals 43 and 45. According to this, it is possible to quickly predict the degree of progress in the range where ion migration occurs.

  From the above detailed description, features and advantages of the embodiments will become apparent. This is intended to cover the features and advantages of the embodiments described above without departing from the spirit and scope of the claims. Also, any improvement and modification should be readily conceivable by those having ordinary knowledge in the art. Therefore, there is no intention to limit the scope of the inventive embodiments to those described above, and appropriate modifications and equivalents included in the scope disclosed in the embodiments can be used.

DESCRIPTION OF SYMBOLS 17 ... Board | substrate; 18 ... Intake fan; 19 ... Exhaust fan; 20 ... Heater; 26 ... Prediction circuit; 28 ... Judgment pattern; 29 ... Input part; 30 ... Receiving part; 31 ... Control part; Judgment part: 37 ... Wiring pattern; 38 ... Through-via

Claims (4)

A plurality of conductor patterns on the substrate;
Input means for inputting an encoded signal to any one of input terminals of the plurality of conductor patterns at one end; and
Receiving means for individually receiving the signals from the output terminals of all the conductor patterns including the conductor pattern to which the signals are input;
The first information related to the code error rate, which is the ratio of the number of error codes of the signal received by the receiving means, to the total number of codes that are the values of the signals input by the input means, and the signal are input Predicting means for predicting a range in which the substrate deteriorates, based on second information on whether or not electrical connection is established between the output terminals of all conductor patterns with respect to the input terminals of the conductor patterns;
A prediction apparatus comprising: The prediction device according to claim 1,
The input means inputs the signal to each input terminal in time series,
The predicting means predicts a range in which the substrate deteriorates based on the first information and the second information detected by the receiving means every time the input means inputs the signal to the input terminal.
A prediction apparatus characterized by that. In the prediction device according to claim 1 or 2,
The conductor pattern includes a wiring pattern that is wired while being separated by a predetermined distance, and a through via disposed between the wiring patterns.
A prediction apparatus characterized by that. In the prediction device according to any one of claims 1 to 3,
Storage means for storing prediction information including the first information and the second information;
Comparison means for comparing the previous prediction information stored in the storage means with the information predicted by the prediction means at this time;
Means for lowering the humidity in the room containing the substrate by the prediction means predicting that the range of deterioration of the substrate is expanded based on the comparison result of the comparison means;
A prediction apparatus comprising:

Images