JP5402528B2 - Printed circuit board and information processing apparatus - Google Patents

Description

  The present invention relates to a printed circuit board and an information processing apparatus including the printed circuit board.

  As is well known, information processing devices (computers, copiers, etc.) use printed circuit boards in which a plurality of electronic components are mounted on a printed wiring board in which a plurality of transmission paths are formed in various places of various conductive layers. It has been.

  There are various types of printed circuit boards that have different frequencies and voltages of signals transmitted and received between electronic components. However, the frequency of signals transmitted and received between electronic components is high and the voltage is low. The influence of the distortion of the signal waveform due to the transmission through the transmission line becomes greater. As a result, transmission errors are likely to occur. For this reason, in printed circuit boards in which relatively high-frequency, low-voltage signals are exchanged between electronic components, an equalizer circuit (equalizer) that performs waveform shaping of a predetermined content on the transmission side or reception side of the transmission path ) Exists.

  In addition, margins (voltage margins and timing margins) at which signals can be correctly exchanged between electronic components vary according to the environmental temperature of the printed wiring board. Therefore, it is also proposed to provide an equalization circuit that can adjust the waveform shaping characteristics (contents of waveform shaping to be executed) on the receiving side of the transmission line, and to adjust the waveform shaping characteristics of the equalization circuit according to the environmental temperature. Has been.

JP 2009-159256 A JP 2000-199681 A JP-A-2005-303607 Japanese Patent No. 4023165

  A printed circuit board provided with an equalization circuit whose waveform shaping characteristics are adjusted according to the environmental temperature is less likely to cause transmission errors than a printed circuit board provided with an equalization circuit that performs waveform shaping of a predetermined content. Become.

  However, the signal transmission loss and propagation delay time during transmission on each transmission line are actually values determined by the temperature of the portion of the printed wiring board where each transmission line is provided. And the temperature of each part of a printed wiring board does not become equal to environmental temperature (it changes later than the change of environmental temperature). In addition, the temperature of each part of the printed wiring board is abrupt when starting up (when the electronic component starts to generate heat or when the amount of heat generated by the electronic component has increased / decreased) even if the environmental temperature is constant. To change.

Therefore, in the printed circuit board having an equalization circuit in which the waveform shaping characteristic is adjusted according to the environmental temperature, when the environmental temperature suddenly changes or when the printed circuit board (information processing apparatus) is started, Incorrect control is performed on the equalization circuit, and as a result, a transmission error may occur. Further, when the material of the circuit board absorbs moisture, signal transmission loss and propagation delay time during transmission in each transmission path change. Even if the ambient temperature is kept constant, the ambient humidity may change due to weather fluctuations. In this case, the method of controlling the equalization circuit according to the environmental temperature cannot detect the transmission loss due to moisture absorption and the change in the propagation delay time, and as a result, a transmission error may occur. become.

  Therefore, an object of the disclosed technique is to provide a printed circuit board in which no transmission error occurs even when the environmental temperature changes suddenly or at the time of startup.

  Another object of the disclosed technique is to provide an information processing apparatus in which a transmission error does not occur in an internal printed circuit board even when the environmental temperature suddenly changes or at the time of startup.

  In order to solve the above-described problem, a printed circuit board according to an aspect of the disclosed technology is a printed circuit board in which a plurality of circuits are mounted on a printed wiring board, and a transmission line formed on the printed wiring board; A signal transmission circuit including a transmission circuit and a reception circuit for transmitting and receiving a signal through the transmission line, and when the signal propagation characteristic of the transmission line is within a predetermined range, the transmission circuit and / or A signal transmission circuit that can be operated in a state in which a signal can be accurately received by the reception circuit by controlling the reception circuit, and a conductive layer in which the transmission line of the printed wiring board is formed, the transmission path A measurement pattern for measuring capacitance, and a control circuit provided on the printed wiring board, wherein the measurement pattern is used. A control circuit for measuring the capacitance and controlling the transmission circuit and / or the reception circuit so that the signal transmission circuit operates in a state where the signal can be accurately received by the reception circuit based on the measurement result; Prepare.

  The information processing apparatus according to one aspect of the disclosed technology is a printed circuit board having a plurality of circuits mounted on a printed wiring board, the transmission path formed on the printed wiring board, and the transmission path When the signal propagation characteristic of the transmission line is within a predetermined range, the receiving circuit is controlled by controlling the transmitting circuit and / or the receiving circuit. And a capacitance formed on the conductive layer in which the transmission path of the printed wiring board is formed adjacent to the transmission path. A printed circuit board having a measurement pattern for measuring a signal, and "based on the measurement result of capacitance by the measurement pattern, the signal is accurately transmitted by the receiving circuit." As the signal transmission circuit in a signal can state operates, and a "the transmitting circuit and / or control means for controlling the reception circuit.

  If the above configuration is adopted, a printed circuit board that does not cause transmission errors even when the environmental temperature changes suddenly or during startup, etc. An information processing apparatus in which no transmission error occurs in a printed circuit board can be realized.

1 is a schematic configuration diagram of a printed circuit board according to a first embodiment. Explanatory drawing of the formation position of a measurement pattern. Explanatory drawing of transmission loss information. Explanatory drawing of propagation delay time information. The flowchart of a state control process. The flowchart of a state monitoring process. Explanatory drawing of the grasping unit (section) of the state by state grasping | ascertainment processing. Explanatory drawing of the content of a state grasping | ascertaining process. The schematic block diagram of the printed circuit board which concerns on 2nd Embodiment.

Hereinafter, two types of printed circuit boards developed by the inventors (hereinafter referred to as printed circuit boards 1 and 2 according to the first and second embodiments) will be described in detail with reference to the drawings.

<< First Embodiment >>
The printed circuit board 1 according to the first embodiment has been developed as a computer motherboard.

  As schematically shown in FIG. 1, the printed circuit board 1 according to the first embodiment includes a monitoring circuit 10, a transmission path 20, a transmission circuit 21, a reception circuit 22, and a measurement pattern 25.

  The transmission circuit 21 is a circuit (IC or the like) that transmits a signal provided on a printed wiring board (not shown) of the printed circuit board 1 in order to execute certain digital processing. The transmission circuit 21 has a function of changing the signal transmission timing and the voltage of the signal to be transmitted in accordance with an instruction from the outside (a control signal from the monitoring circuit 10 / detection circuit 12 described later).

  The reception circuit 22 is a circuit that receives a signal from the transmission circuit 21. Similarly to the transmission circuit 21, the reception circuit 22 is also a circuit provided on a printed wiring board that can adjust the signal reception timing and the voltage of the received signal (the voltage that is considered to have received the signal). .

  The transmission path 20 is a transmission path (copper wiring) formed in a certain conductor layer of the printed wiring board of the printed circuit board 1. Although not shown, the printed circuit board 1 according to the first embodiment includes a plurality of circuits (hereinafter referred to as signal transmission circuits) including the transmission path 20 and the transmission circuit 21 and the reception circuit 22 described above. It is the one with the individual.

  The measurement pattern 25 is a capacitance measurement pattern (in this embodiment, a comb-like pattern) provided for each transmission line 20 (for each signal transmission circuit). The measurement pattern 25 for each transmission line 20 is formed so as to be adjacent to the transmission line 20 on the conductor layer of the printed wiring board on which the corresponding transmission line 20 is formed, as schematically shown in FIG. Has been.

  The monitoring circuit 10 (FIG. 1) includes a transmission circuit 21 and / or a reception circuit in each signal transmission circuit so that a transmission error does not occur even when the environmental temperature of the printed circuit board 1 suddenly changes or at the time of startup. 22 is a circuit for controlling 22. The monitoring circuit 10 is also a circuit that monitors the state of the printed circuit board 1 and outputs an abnormality notification that is digital information indicating that the state of the printed circuit board 1 becomes abnormal.

  More specifically, the monitoring circuit 10 includes a measurement circuit 11, a detection circuit 12 having a nonvolatile storage unit 12b, and a feedback circuit 13.

  The measurement circuit 11 is a circuit that measures the capacitance of a portion where each measurement pattern 25 is provided using each measurement pattern 25 in the printed circuit board 1 under the control of the detection circuit 12. The feedback circuit 13 is a circuit that outputs a control signal having a content instructed from the detection circuit 12 to the transmission circuit 21 and / or the reception circuit 22 of each signal transmission circuit.

  The detection circuit 12 is a circuit that starts state control processing and state monitoring processing when started (when a computer incorporating the printed circuit board 1 is started). In the printed circuit board 1 according to the present embodiment, the detection circuit 12 is realized by using the CPU, the nonvolatile memory, and the RAM on the printed circuit board 1.

The state control process and the state monitoring process executed by the detection circuit 12 are both processes that refer to information stored in the nonvolatile storage unit 12b. Therefore, before describing the details of each process, the type / content of information stored in the nonvolatile storage unit 12b will be described.

  The nonvolatile storage unit 12b of the detection circuit 12 stores transmission loss information, propagation delay time information, and capacitance transition pattern information for each measurement pattern 25.

  By referring to the transmission loss information, the transmission loss of the transmission line 20 adjacent to the measurement pattern 25 can be estimated from the capacitance measurement result of a certain (arbitrary) measurement pattern 25 by referring to the transmission loss information. The propagation delay time information is information that can be used to estimate the propagation delay time of the transmission line 20 adjacent to the measurement pattern 25 from the measurement result of the capacitance according to the measurement pattern 25 by referring to the propagation delay time information.

  Such transmission loss information and propagation delay time information can be prepared by various methods, but the printed circuit board 1 is prepared with transmission loss information and propagation delay time information by the following method. .

  At the time of development of the printed circuit board 1, a printed wiring board corresponding to a simplified printed wiring board of the printed circuit board 1 is manufactured. That is, the constituent material of each part is the same as that of the printed wiring board of the printed circuit board 1, and a transmission path for measuring transmission loss and propagation delay time (equivalent to the transmission path 20) and a capacitance measurement pattern (equivalent to the measurement pattern 25) A lint wiring board is manufactured.

  Further, after maintaining the surrounding environment of the printed wiring board in a certain environment (hereinafter referred to as an experimental environment) for a long time, the transmission loss and the propagation delay time of the transmission line formed on the printed wiring board are measured. In addition, a capacitance measurement pattern formed on the printed wiring board is used to measure the capacitance of a portion where the pattern is formed for each of a plurality of experimental environments having different temperatures and humidity. Yes.

  And the transmission loss information which concerns on 1st Embodiment becomes the information (information equivalent to the dotted line in FIG. 3) prepared based on each measurement result ((circle) of FIG. 3) in the said experiment, as shown in FIG. Yes. Also, the propagation delay time information is information prepared based on each measurement result (◯ in FIG. 4) in the above experiment, as shown in FIG.

  The capacitance transition pattern information for each measurement pattern 25 in the nonvolatile storage unit 12b (FIG. 1) is that the measurement result of the capacitance by each measurement pattern 25 is normally (when there is no abnormality in each part of the printed circuit board 1). It is information indicating how the time changes after the computer incorporating the printed circuit board 1 is started. Although details will be described later, this capacitance transition pattern information is information that may not be stored in advance in the nonvolatile storage unit 12 (before the actual operation of the printed circuit board 1).

  The state control process executed by the detection circuit 12 is a process of the procedure shown in FIG. 5 performed with reference to the transmission loss information and the propagation delay time information.

  That is, since it has been activated (the computer incorporating the printed circuit board 1 has been activated), the detection circuit 12 that has started this state control process first controls the measurement circuit 11 to thereby determine the capacitance related to each signal transmission circuit. Is measured and stored (step S101). The capacitance related to each signal transmission circuit refers to the capacitance (capacitance measured by the measurement pattern 25) of the portion where the measurement pattern 25 is provided in the vicinity of the transmission path 20 of each signal transmission circuit.

Next, the detection circuit 12 waits for the elapse of a predetermined time (step S102). And
When the predetermined time has elapsed, the detection circuit 12 controls the measurement circuit 11 to measure and store the capacitance related to each signal transmission circuit (step S103). The process of step S103 is a process of storing the measurement results so that the number of measurement results in the detection circuit 12 does not exceed a predetermined number and the latest measurement result group remains in the detection circuit 12. Yes.

  Thereafter, the detection circuit 12 compares, for each signal transmission circuit, the current capacitance measurement result and the previous capacitance measurement result to determine whether or not there is a signal transmission circuit whose capacitance has changed by more than a specified value. Judgment is made (step S104).

  When such a signal transmission circuit (hereinafter referred to as an adjustment signal transmission circuit requiring adjustment) does not exist (step S104; NO), the detection circuit 12 starts the processing from step S102 again.

  On the other hand, when there are several adjustment signal transmission circuits that need adjustment (step S104; YES), the detection circuit 12 refers to the transmission loss information and the propagation delay time information, and transmits the transmission circuit in each adjustment signal transmission circuit that requires adjustment. 21 and / or the receiving circuit 22 is controlled (step S105) so as to perform good signal transmission.

  In other words, the detection circuit 12 transmits a signal having a larger voltage with a transmission timing earlier than the transmission circuit 21 in the adjustment signal transmission circuit required for the adjustment signal transmission circuit whose capacitance is larger than a specified value. Processing for controlling to a state (see FIGS. 3 and 4), processing for controlling the receiving circuit 22 in the adjustment signal transmission circuit to be adjusted to a state in which the reception timing is later and a signal having a smaller voltage is received, and adjustment is required. One of the processes for controlling both the transmission circuit 21 and the reception circuit 22 in the signal transmission circuit (according to the actual situation) is performed. In addition, the detection circuit 12 transmits a signal having a smaller voltage with a later transmission timing to the transmission circuit 21 in the adjustment signal transmission circuit required for the adjustment signal transmission circuit whose capacitance has become smaller than a predetermined value. Processing for controlling to a state, processing for controlling the receiving circuit 22 in the adjustment signal transmission circuit requiring adjustment to a state for receiving a signal having a higher reception timing and a larger voltage, transmission circuit 21 in the signal transmission circuit requiring adjustment One of the processes for controlling both the receiver circuit 22 and the receiver circuit 22 is performed.

  And the detection circuit 12 which finished the process of step S105 starts the process from step S102 again.

  The state monitoring process executed by the detection circuit 12 is a process of the procedure shown in FIG. 6 performed with reference to the capacitance transition pattern information described above.

  That is, since it has been activated, the detection circuit 12 that has started this state monitoring process first waits for the specified time to elapse (step S201).

  Next, the detection circuit 12 determines each section of the printed circuit board 1 based on the capacitance measurement result group obtained by the state control process, each capacitance transition pattern information on the nonvolatile storage unit 12b, and the elapsed time after activation. A state grasping process (step S202) for grasping (determining) the state is performed. The section of the printed circuit board 1 is, as schematically shown in FIG. 7, a portion centered on each measurement pattern 25 of the printed wiring board and a circuit group (not shown) arranged thereon. It is the part which becomes. The size of each compartment need not be the same.

In this state grasping process, basically, as schematically shown in FIG. 8, the measurement result of the capacitance by the measurement pattern 25 in a certain section is the same as the standard pattern indicated by the corresponding capacitance transition pattern information. This is a process for determining that the state of the section has become an abnormal state when the state that does not transition (change) to the state continues for a certain time or longer. However, the state grasping process is a process for determining that the state of the section is in an abnormal state even if the predetermined time has not elapsed when the capacitance related to a certain section is suddenly changed.

  The detection circuit 12 that has finished the state grasping process (FIG. 6: step S202), when there is no determined section that is in an abnormal state in the state grasping process (step S203; NO), starts from step S201. Start the process again.

  On the other hand, when there is a partition determined to be in an abnormal state in the state grasping process (step S203; YES), the detection circuit 12 identifies the identification information and each partition determined to be in the abnormal state. An abnormality notification including information indicating the content of the abnormal phenomenon occurring in step S204 is output (step S204). If the detection circuit 12 is in an abnormal state due to the capacitance being too large, the life of the printed circuit board 1 (the printed wiring board) is absorbed in step S204 due to moisture absorption. An abnormality notification including information indicating that is approaching is output.

  In addition, the abnormality notification actually output by the detection circuit 12 according to the present embodiment is displayed on the display of the computer in which the printed circuit board 1 is incorporated in the identification information of each section in an abnormal state or each section. This is information (command group) that displays a warning window showing information indicating the contents of the abnormal phenomenon that has occurred.

  And the detection circuit 12 which finished the process of step S204 starts the process from step S201 again.

  Finally, the operation of the detection circuit 12 when the capacitance transition pattern information is not stored in the nonvolatile storage unit 12b will be described.

  The detection circuit 12 actually has effective capacitance transition pattern information regarding each signal transmission circuit (stored in the nonvolatile storage unit 12b) before starting the state monitoring process (FIG. 6). ) Is configured as a circuit for determining whether or not. The effective capacitance transition pattern information is information (see FIG. 8) in which the capacitance is measured until the capacitance is stabilized.

  Then, when there is no effective capacitance transition pattern information, the detection circuit 12 does not start the state monitoring process, and the capacitance measured for each signal transmission circuit by the state control process is transmitted to each signal transmission. The process of storing in the nonvolatile storage unit 12b as an element of capacitance transition pattern information regarding the circuit is started.

  As is clear from the above description, the printed circuit board 1 always has the transmission line 20 (even when the environmental temperature changes abruptly or when the temperature of each part of the printed circuit board 1 starts to rise due to activation). Based on the measurement result of the capacitance in the vicinity of the transmission line 20 that strongly correlates with the transmission loss and propagation delay time, the operating conditions of the transmission circuit 21 and / or the reception circuit 22 are changed so that signal transmission can be performed satisfactorily. It has the composition which is.

  Therefore, in this printed circuit board 1, a transmission error does not occur even when the environmental temperature changes suddenly or at the time of startup.

Further, the printed circuit board 1 grasps the state of each section from the measurement result of the capacitance, and when there is an abnormal section, notifies the manager or the like (a warning window is displayed on the display). ) A computer can be realized. Therefore, the printed circuit board 1 is also a printed circuit board that can be repaired, replaced, etc. before a problem actually occurs.

<< Second Embodiment >>
Hereinafter, the configuration and functions of the printed circuit board 1 according to the second embodiment will be described with a focus on differences from the printed circuit board 1 according to the first embodiment.

FIG. 9 shows a schematic configuration of the printed circuit board 2 according to the second embodiment.
The transmission circuit 21b and the reception circuit 22b included in the printed circuit board 2 are circuits corresponding to the transmission circuit 21 and the reception circuit 22, respectively, in which a function for changing (adjusting) transmission / reception timing is removed.

  Equalization circuits 23 and 24 provided between the transmission circuit 21b and the transmission line 20 and between the transmission line 20 and the transmission circuit 22b can adjust the contents of the waveform shaping to be performed for waveform shaping. It is a simple circuit.

  The monitoring circuit 10 included in the printed circuit board 2 is essentially a circuit having the same function and configuration as the monitoring circuit 10 included in the printed circuit board 1. However, the monitoring circuit 10 (detection circuit 12) in the printed circuit board 2 is equalized so that signal transmission can be performed satisfactorily based on the measurement result of the capacitance in the vicinity of the transmission line 20, as is apparent from the figure. This is a circuit for controlling the operating conditions (the contents of the waveform shaping to be executed) of the circuit 23 and / or the equalizing circuit 24.

  In short, as for this printed circuit board 2, the transmission circuit 21 equivalent is realized by “transmission circuit 21 b + equalization circuit 23”, and the reception circuit 22 equivalent is realized by “equalization circuit 24 + reception circuit 22 b”. It has become.

  Therefore, similarly to the printed circuit board 1, the printed circuit board 2 is also a printed circuit board in which no transmission error occurs even when the environmental temperature changes suddenly or during startup.

<Deformation>
The printed circuit boards 1 and 2 according to the above-described embodiments can be variously modified. For example, in the printed circuit board 1 according to the first embodiment, all or some of the transmission circuits 21 are circuits in which the transmission timing or the like cannot be adjusted, or all or some of the reception circuits 22 are It can be transformed into a circuit that cannot adjust the reception timing or the like. Further, the printed circuit board 2 according to the second embodiment may be modified into a circuit in which an equalization circuit (23 or 24) is provided only on the transmission side or the reception side of a part or all of the transmission paths 20. I can do it.

  A part of the monitoring circuit 10 (for example, the detection circuit 12) may be a circuit outside the printed circuit boards 1 and 2 (a circuit provided on the information processing apparatus side in which the printed circuit boards 1 and 2 are incorporated). The monitoring circuit 10 can be transformed into a circuit that does not hold the capacitance transition pattern information and determines the state of each section by comparing the magnitude of the capacitance related to each section.

  In addition, the printed circuit boards 1 and 2 have only a function of grasping the state of each section from the capacitance measurement result and outputting information indicating that when there is an abnormal section (transmission error) It is also possible to modify it to have no function of preventing occurrence of

DESCRIPTION OF SYMBOLS 1, 2 Printed circuit board 10 Monitoring circuit 11 Measurement circuit 12 Detection circuit 12b Nonvolatile memory | storage part 13 Feedback circuit 20 Transmission path 21, 21b Transmission circuit 22, 22b Reception circuit 23, 24 Equalization circuit 25 Measurement pattern

Claims (5)

In a printed circuit board in which a plurality of circuits are mounted on a printed wiring board,
A signal transmission circuit including a transmission line formed on the printed wiring board, and a transmission circuit and a reception circuit for transmitting and receiving a signal through the transmission line, and a signal propagation characteristic of the transmission line is within a predetermined range A signal transmission circuit that can be operated in a state in which signals can be accurately received by the reception circuit by control of the transmission circuit and / or the reception circuit,
A measurement pattern for measuring capacitance, which is formed adjacent to the transmission path on the conductive layer in which the transmission path of the printed wiring board is formed,
A control circuit provided on the printed wiring board, measuring a capacitance using the measurement pattern, and operating the signal transmission circuit in a state in which a signal can be accurately received by the reception circuit based on the measurement result. A printed circuit board comprising: a control circuit that controls the transmission circuit and / or the reception circuit. The monitoring circuit is
Based on the measurement result of the capacitance according to the measurement pattern, the state of the self-printed circuit board is monitored to be in an abnormal state, and when the state of the self-printed circuit board is in an abnormal state, information indicating that is output The printed circuit board according to claim 1, wherein the printed circuit board has a function of: A printed circuit board having a plurality of circuits mounted on a printed wiring board, including a transmission path formed on the printed wiring board, and a transmission circuit and a reception circuit that exchange signals through the transmission path. When the signal propagation characteristic of the transmission line is within a predetermined range, the transmission circuit and / or the reception circuit can be controlled so that the signal can be accurately received by the reception circuit. A printed circuit board having a signal transmission circuit and a measurement pattern for measuring capacitance formed on the conductive layer in which the transmission path of the printed wiring board is formed adjacent to the transmission path;
Control means for controlling the transmission circuit and / or the reception circuit so that the signal transmission circuit operates in a state where the signal can be accurately received by the reception circuit based on the measurement result of the capacitance by the measurement pattern. An information processing apparatus characterized by that. Based on the measurement result of capacitance by the measurement pattern on the printed circuit board of the printed circuit board, the state of the own printed circuit board is monitored to be in an abnormal state, and the state of the own printed circuit board is in an abnormal state Is provided with a monitoring circuit having a function of outputting information indicating that,
When information indicating that the state of the printed circuit board is in an abnormal state is output from the monitoring circuit of the printed circuit board, warning information for notifying the administrator of the device is output. The information processing apparatus according to claim 3, further comprising warning information output means. In a printed circuit board in which a plurality of circuits are mounted on a printed wiring board,
A plurality of measurement patterns for measuring capacitance provided on the printed wiring board;
A state detection circuit provided on the printed wiring board, wherein the capacitance is measured using each of the plurality of measurement patterns, and the state of the own printed circuit board becomes an abnormal state based on the measurement result. And a state monitoring circuit that outputs information indicating that when the state of the self-printed circuit board becomes an abnormal state.

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