Circuit board, display device, environment forming apparatus, and method for measuring noise of circuit board

Abstract

To easily identify the locations on a circuit board affected by noise without using measuring instruments such as an oscilloscope, and to efficiently measure the influence of noise over a wide area of the circuit board with respect to an arbitrary location of the circuit board.SOLUTION: A circuit board (1) is a circuit board to be subjected to noise measurement, and includes: a control circuit (10); and communication wiring (11) connected annularly to the control circuit (10) and provided in advance on the circuit board (1). The control circuit (10) includes: a transmitting unit for transmitting a predetermined digital signal to the communication wiring; a receiving unit for receiving the digital signal from the communication wiring; and a detecting unit for detecting a code error occurring in the digital signal received by the receiving unit. The circuit board (1) further includes an output circuit (12) for outputting information relating to the code error detected by the detecting unit.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a technique for measuring the influence of noise on a circuit board. [Background technology]

[0002] A thermo-hygrostat for environmental testing according to the background art is disclosed, for example, in Patent Document 1. The thermo-hygrostat includes a refrigeration device, a heating device, a dehumidification device, and a humidification device as electrical devices for adjusting the environment in a test room.

[0003] Furthermore, an oscilloscope according to the background art is disclosed in, for example, Patent Document 2. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-66593 [Patent Document 2] Patent No. 2817179 Summary of the Invention [Problem to be solved by the invention]

[0005] When a performance test is conducted before shipping of an environmental forming device such as a temperature and humidity control device, or when a malfunction occurs after shipping, workers use measuring instruments such as an oscilloscope or noise data logger to identify the areas affected by noise that may be the cause of the malfunction.

[0006] However, since specialized knowledge is required to operate these measuring instruments, the number of workers who can use them is limited.

[0007] Furthermore, when identifying the areas on a circuit board that are affected by noise, it may be necessary to modify or rearrange the circuit board in order to place the probes of these measuring instruments on the measurement target. For this reason, when analyzing failures in finished products, the areas that can be measured may be limited.

[0008] Furthermore, these measuring instruments are only capable of local measurements, and therefore cannot efficiently measure the effects of noise over a wide area on a circuit board.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a circuit board, a display device, an environment forming device, and a noise measurement method for a circuit board that can easily identify the areas on a circuit board that are affected by noise without using a measuring instrument such as an oscilloscope, and that can target any area on the circuit board and efficiently measure the effects of noise over a wide area on the circuit board. [Means for solving the problem]

[0010] A circuit board according to a first aspect of the present invention is a circuit board on which noise is measured, and comprises a control circuit and a communication wiring that is connected in a ring shape to the control circuit and is pre-installed on the circuit board, wherein the control circuit includes a transmitter that transmits a predetermined digital signal to the communication wiring, a receiver that receives the digital signal from the communication wiring, and a detector that detects code errors occurring in the digital signal received by the receiver, and further comprises an output circuit that outputs information regarding the code errors detected by the detector.

[0011] In this aspect, a digital signal is transmitted to a communication wiring provided in advance on a circuit board, a code error occurring in the digital signal received from the communication wiring is detected, and information about the detected code error is output. If the circuit board is affected by noise, a code error occurs in the digital signal. Therefore, according to this aspect, it is possible to easily identify whether an area on the circuit board near the communication wiring is affected by noise, without using a measuring instrument such as an oscilloscope.

[0012] Furthermore, according to this aspect, by providing communication wiring in advance to surround a desired location on the circuit board, it is possible to efficiently measure the effects of noise in a wide area including the desired location on the circuit board without modifying or changing the layout of the circuit board during failure analysis after shipment.

[0013] A circuit board according to a second aspect of the present invention is a circuit board according to the first aspect, wherein the control circuit further includes an evaluation unit that quantifies the occurrence status of the code error detected by the detection unit, and the information about the code error includes a numerical value indicating the occurrence status of the code error quantified by the evaluation unit.

[0014] In this embodiment, the information about the bit error output by the output circuit includes a numerical value indicating the occurrence of the bit error, so that the influence of noise in the area near the communication wiring can be quantitatively evaluated based on the numerical value.

[0015] A circuit board according to a third aspect of the present invention is the circuit board according to the first aspect, wherein the control circuit further includes a setting unit that variably sets at least one of the period and amplitude of the digital signal transmitted by the transmitting unit.

[0016] According to this aspect, at least one of the period and amplitude of the digital signal transmitted by the transmitter is set to be variable, thereby making it possible to adjust the sensitivity of detecting code errors.

[0017] A display device according to a fourth aspect of the present invention comprises a circuit board according to any one of the first to third aspects, an information receiving unit that receives information output by the output circuit, and an information display unit that displays the information received by the information receiving unit.

[0018] According to this aspect, it is possible to visualize information about code errors output by the output circuit and provide it to the user.

[0019] An environmental forming device according to a fifth aspect of the present invention comprises a circuit board according to any one of the first to third aspects and an environmental forming chamber, wherein the circuit board constitutes at least a part of a control device that controls electrical equipment that adjusts the environment within the environmental forming chamber, or a part of a measuring device that measures the environmental conditions within the environmental forming chamber or the conditions of an object placed within the environmental forming chamber.

[0020] According to this aspect, it is possible to provide a user with an environment creating device that can easily identify whether an area near a communication wiring on a circuit board that constitutes at least a part of a control device that controls an electrical device that adjusts the environment in the environment creating chamber or a part of a measuring device that measures the environmental status of the environment creating chamber or the status of an object placed in the environment creating chamber is affected by noise, without using a measuring instrument such as an oscilloscope. Furthermore, according to this aspect, it is possible to efficiently measure the effect of noise on the area near the communication wiring on the circuit board in failure analysis after shipment, without modifying or changing the placement of the circuit board or the electrical device.

[0021] An environment forming device according to a sixth aspect of the present invention is an environment forming device according to the fifth aspect, further comprising an information receiving unit that receives information output by the output circuit, an information storage unit that stores the information, and an information processing unit that associates the information received by the information receiving unit with information regarding the operation of the environment forming device and stores it in the information storage unit.

[0022] In this aspect, information about the code error output by the output circuit is stored in the information storage unit in association with operation information of the environment creating device, which enables detailed analysis of the causal relationship or correlation between the operation of the environment creating device and noise generation on the circuit board.

[0023] A seventh aspect of the present invention provides a noise measurement method for a circuit board, the circuit board comprising: a control circuit; a communication wiring connected in a ring shape to the control circuit and pre-installed on the circuit board; and an output circuit; the control circuit transmits a predetermined digital signal to the communication wiring, receives the digital signal from the communication wiring, and detects a code error occurring in the received digital signal; and the output circuit outputs information regarding the code error detected by the control circuit.

[0024] In this aspect, a digital signal is transmitted to a communication wiring provided in advance on a circuit board, a code error occurring in the digital signal received from the communication wiring is detected, and information regarding the detected code error is output. Therefore, according to this aspect, it is possible to easily identify whether an area near the communication wiring on the circuit board is affected by noise without using a measuring instrument such as an oscilloscope.

[0025] Furthermore, according to this aspect, by providing communication wiring in advance to surround a desired location on the circuit board, it is possible to efficiently measure the effects of noise in a wide area including the desired location on the circuit board without modifying or changing the layout of the circuit board during failure analysis after shipment. [Effects of the Invention]

[0026] According to the present invention, it is possible to easily identify the areas on a circuit board that are affected by noise without using a measuring instrument such as an oscilloscope, and it is also possible to efficiently measure the effects of noise over a wide area on the circuit board by targeting any area on the circuit board. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a diagram showing an overall configuration of a display device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a diagram illustrating a configuration of a control circuit. [Figure 3] FIG. 1 is a diagram illustrating a portion of a digital signal. [Figure 4] FIG. 2 is a diagram showing a first example of a display mode of a display unit. [Figure 5] FIG. 10 is a diagram showing a second example of the display mode of the display unit. [Figure 6] FIG. 10 is a diagram illustrating an example of the layout of a plurality of communication lines. [Figure 7] 1 is a diagram showing the overall configuration of an environment creating device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0028] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Elements with the same reference numerals in different drawings indicate the same or corresponding elements.

[0029] 1 is a diagram showing the overall configuration of a display device 3 according to an embodiment of the present invention. The display device 3 includes three circuit boards 1A, 1B, and 1C, which are targets for noise measurement, and a processing unit 2.

[0030] Circuit board 1A and circuit board 1B are connected to each other so that they can communicate with each other using communication cable 17A. Circuit board 1B and circuit board 1C are connected to each other so that they can communicate with each other using communication cable 17B. Circuit board 1C and processing unit 2 are connected to each other so that they can communicate with each other using communication cable 17C. As a result, circuit board 1A is connected to processing unit 2 so that they can communicate with each other via circuit board 1B and circuit board 1C. Circuit board 1B is connected to processing unit 2 so that they can communicate with each other via circuit board 1C.

[0031] Each of the three circuit boards 1A, 1B, and 1C may be directly connected to the processing unit 2 using a communication cable so that they can communicate with each other. The number of circuit boards included in the display device 3 is not limited to three, and may be one, two, four, or more. When the display device 3 includes multiple circuit boards, it is sufficient that at least one circuit board has the same configuration as the three circuit boards 1A, 1B, and 1C. Hereinafter, when one or more circuit boards included in the display device 3 are collectively referred to as circuit board 1.

[0032] The circuit board 1 can be applied to an environment creating device equipped with an environment creating chamber, and to information processing devices such as personal computers. When the circuit board 1 is applied to an environment creating device, the circuit board 1 can be applied to a circuit board that constitutes at least a part of a control device that controls electrical equipment such as a heating device, a cooling device, and a humidifying device that adjusts the environment in the environment creating chamber. Alternatively, the circuit board 1 can be applied to a circuit board that constitutes a part of a measuring device that measures the environmental conditions in the environment creating chamber or the conditions of an object placed in the environment creating chamber. Details of an example of the application of the circuit board 1 to an environment creating device will be described later.

[0033] When the circuit board 1 is applied to an information processing device, the circuit board 1 can be applied to a circuit board provided with an interface circuit, a communication circuit, and / or a power supply circuit, etc. The interface circuit is a circuit that inputs and outputs data to and from an external storage medium such as a semiconductor memory. The communication circuit is a circuit that transmits and receives data to and from an external device. The power supply circuit is a circuit that converts input power into power appropriate for each part of the information processing device.

[0034] The circuit board 1A includes a control circuit 10A, a communication wiring 11A, a communication circuit 12A (output circuit), a first communication port 15A, and a second communication port 16A.

[0035] The control circuit 10A is configured using a microprocessor or a microcontroller, etc. The control circuit 10A controls the operation of electrical devices (not shown) included in the display device 3. The control circuit 10A also evaluates the effect of noise on the circuit board 1A. Noise includes high-frequency noise coming from outside as radio waves, low-frequency noise mixed in from power lines, etc., and single-shot noise caused by static electricity. In other words, the control circuit 10A combines the original function of the circuit board 1, such as controlling electrical devices, with the function of evaluating the effect of noise on the circuit board 1.

[0036] The communication wiring 11A conforms to a predetermined communication standard and is used by the control circuit 10A to evaluate the influence of noise on the circuit board 1A. The communication standard is, for example, UART or RS-232, which are susceptible to noise. The communication wiring 11A is formed in advance as a wiring pattern on the circuit board 1A so as to be connected to the control circuit 10A in a circular shape. The communication wiring 11A is formed so as to surround a portion of the circuit board 1A that is likely to be influenced by noise. In this embodiment, in order to evaluate the influence of noise on the entire circuit board 1A, the communication wiring 11A is formed so as to follow the edge of the circuit board 1A.

[0037] The communication circuit 12A is configured using a communication module that complies with a predetermined communication standard. The first communication port 15A and the second communication port 16A are communication ports that comply with the same communication standard as the communication circuit 12A. The communication standard is, for example, RS-422 or RS-485, which are less susceptible to noise. However, the communication standard may also be UART or RS-232, which are more susceptible to noise.

[0038] Under the control of the control circuit 10A, the communication circuit 12A transmits information to be sent to the processing unit 2 from the second communication port 16A to the circuit board 1B via the communication cable 17A. The communication circuit 12A outputs information to be sent to the circuit board 1A, which is received by the second communication port 16A via the communication cable 17A, to the control circuit 10A.

[0039] The circuit board 1B includes a control circuit 10B, a communication wiring 11B, a communication circuit 12B (output circuit), a first communication port 15B, and a second communication port 16B, similar to the control circuit 10A. However, under the control of the control circuit 10B, the communication circuit 12B transmits information to be sent to the processing unit 2 from the second communication port 16B via a communication cable 17B to the circuit board 1C. Furthermore, the communication circuit 12B transfers information to be sent to the processing unit 2, which is received from the circuit board 1A by the first communication port 15B, to the circuit board 1C from the second communication port 16B via the communication cable 17B. Furthermore, the communication circuit 12B outputs information to be sent to the circuit board 1B, which is received by the second communication port 16B via the communication cable 17B, to the control circuit 10B.

[0040] The circuit board 1C includes a control circuit 10C, a communication wiring 11C, a communication circuit 12C (output circuit), a first communication port 15C, and a second communication port 16C, similar to the control circuit 10B. However, under the control of the control circuit 10C, the communication circuit 12C transmits information to be sent to the processing unit 2 from the second communication port 16C via a communication cable 17C to the processing unit 2. Furthermore, the communication circuit 12C transfers information to be sent to the processing unit 2, which is received from the circuit board 1B by the first communication port 15C, to the processing unit 2 from the second communication port 16C via the communication cable 17C. Furthermore, the communication circuit 12C outputs information to be sent to the circuit board 1C, which is received by the second communication port 16C via the communication cable 17C, to the control circuit 10C.

[0041] Hereinafter, when the control circuits (control circuits 10A, 10B, and 10C in FIG. 1) provided on circuit board 1 are referred to collectively, they will be referred to as control circuits 10. When the communication wiring (communication wiring 11A, 11B, and 11C in FIG. 1) provided on circuit board 1 are referred to collectively, they will be referred to as communication wiring 11. When the communication circuits (communication circuits 12A, 12B, and 12C in FIG. 1) provided on circuit board 1 are referred to collectively, they will be referred to as communication circuits 12 (output circuits). When the first communication ports (first communication ports 15A, 15B, and 15C in FIG. 1) provided on circuit board 1 are referred to collectively, they will be referred to as first communication ports 15. When the second communication ports (second communication ports 16A, 16B, and 16C in FIG. 1) provided on circuit board 1 are referred to collectively, they will be referred to as second communication ports 16.

[0042] The processing unit 2 is made up of a communication section 21 (information receiving section), a communication port 24, a display section 22 (information display section), a storage section 23, and a processing section 20.

[0043] The communication unit 21 is configured using a communication module that complies with the same communication standard as the communication circuit 12 provided on the circuit board 1. The communication port 24 is a communication port that complies with the same communication standard as the communication unit 21. The communication unit 21 outputs information received by the communication port 24 to the processing unit 20. Under the control of the processing unit 20, the communication unit 21 transmits information to be sent to the circuit board 1 from the communication port 24 to the circuit board 1 via the communication cable 17C.

[0044] The display unit 22 is configured using a liquid crystal display, an organic EL (Electro-Luminescence) display, or the like. Note that the display unit 22 may be configured as a touch panel display, so that the display unit 22 also serves as an input unit for the user to input setting information, etc. The display unit 22 displays various information under the control of the processing unit 20.

[0045] The storage unit 23 is configured using a computer-readable recording medium such as a hard disk drive (HDD), a solid state drive (SSD), or a semiconductor memory. The storage unit 23 may also be configured using a removable recording medium such as an SD card. The storage unit 23 stores various information under the control of the processing unit 20.

[0046] The processing unit 20 is configured using a processor such as a CPU. The processing unit 20 performs various processes by having the processor execute programs read from the storage unit 23. The various processes include, for example, a process of periodically storing information related to the operation of the display device 3 (hereinafter, operation information) in the storage unit 23, and a process of acquiring information input to the display device 3 by a user operating an operation device (e.g., a keyboard and a mouse) not shown. The various processes also include a process of controlling the communication unit 21 to transmit information to the circuit board 1, a process of displaying the information received by the communication unit 21 on the display unit 22, and a process of storing the information received by the communication unit 21 in the storage unit 23.

[0047] The operation information includes, for example, information indicating the driving status (e.g., on or off) of electrical devices controlled by each circuit board 1 included in the display device 3 and / or other electrical devices included in the display device 3. The information related to the operation of the display device 3 may further include information indicating the measurement results of a measuring device (e.g., a temperature sensor) not shown included in the display device 3.

[0048] Next, a detailed description will be given of the configuration of the control circuit 10. Fig. 2 is a diagram showing the configuration of the control circuit 10. The control circuit 10 includes a resistive element 106, an insulating circuit 105, a transmitting unit 103, a receiving unit 104, and a control unit 100.

[0049] The resistive element 106 is a variable resistor whose resistance value can be changed by a digital signal. The insulating circuit 105 is a circuit that electrically insulates the communication wiring 11 from the transmitting unit 103 and the receiving unit 104. The insulating circuit 105 is configured using, for example, a photocoupler.

[0050] The transmitter 103 and the receiver 104 are configured using communication modules that comply with the same communication standard (e.g., UART or RS-232) as the communication wiring 11. The transmitter 103 periodically (e.g., every one second) transmits a predetermined digital signal to the communication wiring 11 via the isolation circuit 105 and the resistor element 106. The predetermined digital signal is, for example, a pulse train in which binary logic values ​​such as "0" and "1" are alternately repeated a predetermined number of bytes. Since the communication wiring 11 is connected to the control circuit 10 in a circular manner, the receiver 104 receives the digital signal transmitted by the transmitter 103 from the communication wiring 11 via the isolation circuit 105. The receiver 104 outputs the received digital signal to the control unit 100. The transmitter 103 may transmit the predetermined digital signal continuously.

[0051] The control unit 100 is configured using a processor such as a CPU and a memory. The control unit 100 has a detection unit 107, an evaluation unit 108, and a setting unit 109 as functions realized by the processor executing a program read from the memory.

[0052] The detection unit 107 detects any code errors occurring in the digital signal received by the reception unit 104. Specifically, every time the reception unit 104 receives a digital signal of a pulse train with a predetermined number of bytes, the detection unit 107 detects the code error by comparing the data content (i.e., bit configuration) of the digital signal with the data content of a known digital signal transmitted by the transmission unit 103. As a code error detection method, a well-known code error detection method such as a parity bit method, a checksum method, or a CRC method can be used.

[0053] The evaluation unit 108 quantifies the occurrence status of the code error detected by the detection unit 107. The evaluation unit 108 transmits the numerical value indicating the occurrence status of the code error to the processing unit 2 as information on the code error detected by the detection unit 107.

[0054] Specifically, the evaluation unit 108 calculates instantaneous and cumulative values ​​of the code errors detected by the detection unit 107 as values ​​indicating the occurrence status of the code errors detected by the detection unit 107. More specifically, every time the receiving unit 104 receives a digital signal of a pulse train of a predetermined number of bytes, the evaluation unit 108 calculates the number of code errors (i.e., the number of bit errors) detected by the detection unit 107 as the instantaneous value of the code errors. Furthermore, after power is applied to the circuit board 1, every time the receiving unit 104 receives a digital signal of a pulse train of a predetermined number of bytes, the evaluation unit 108 adds up the number of code errors detected by the detection unit 107, and calculates the result of this addition as the cumulative value of the code errors.

[0055] Furthermore, the evaluation unit 108 calculates the noise influence level on the circuit board 1 corresponding to the code error occurrence state as a numerical value indicating the code error occurrence state detected by the detection unit 107. Specifically, if the instantaneous value of the code error is less than the first threshold, the noise influence level on the circuit board 1 can be evaluated to be a low level (normal level). In this case, the evaluation unit 108 calculates a numerical value indicating a low level (for example, "1") as the noise influence level on the circuit board 1.

[0056] Similarly, if the instantaneous value of the bit error is equal to or greater than the first threshold and less than a second threshold that is greater than the first threshold, the noise influence level on the circuit board 1 can be evaluated to be a medium level (warning level). In this case, the evaluation unit 108 calculates a numerical value (e.g., "2") indicating the medium level as the noise influence level on the circuit board 1. If the instantaneous value of the bit error is equal to or greater than the second threshold, the noise influence level on the circuit board 1 can be evaluated to be a high level (abnormal level). In this case, the evaluation unit 108 calculates a numerical value (e.g., "9") indicating the high level as the noise influence level on the circuit board 1.

[0057] As described above, the evaluation unit 108 may use a cumulative value of the code errors instead of the instantaneous value of the code errors to calculate the noise influence level on the circuit board 1. The evaluation unit 108 may calculate the noise influence level on the circuit board 1 in two stages using one threshold value, or in four or more stages using three or more threshold values.

[0058] After the evaluation unit 108 quantifies the occurrence of the code error detected by the detection unit 107, it controls the communication circuit 12 to transmit information including the time when the code error was detected (hereinafter referred to as the detection time), the instantaneous value and cumulative value of the code error, and the level of noise impact on the circuit board 1 to the processing unit 2 as information regarding the code error.

[0059] Setting section 109 variably sets the period and amplitude of the digital signal transmitted by transmission section 103. FIG.

[0060] Specifically, setting unit 109 inputs a signal indicating the period P of the digital signal to transmitting unit 103, and thereby sets the period P of the digital signal transmitted by transmitting unit 103 to the period P indicated by the signal. In other words, setting unit 109 variably sets the period P of the digital signal transmitted by transmitting unit 103, and thereby variably sets the frequency of the digital signal transmitted by transmitting unit 103.

[0061] For example, the shorter the period P, the more opportunities there are to detect code errors, and the higher the code error detection sensitivity. For this reason, the setting unit 109 sets the period P of the digital signal transmitted by the transmitting unit 103 to the same period as the digital signal with the shortest period that can be transmitted by the transmitting unit 103. Information indicating the period of the digital signal with the shortest period that can be transmitted by the transmitting unit 103 is stored in advance in a memory (not shown) provided in the control unit 100. However, the period P of the digital signal transmitted by the transmitting unit 103 that is set by the setting unit 109 is not limited to this.

[0062] For example, the processing unit 20 may acquire information input by the user to the display device 3 indicating the period P of the digital signal transmitted by the transmission unit 103, and transmit the information to the circuit board 1. In response to this, when the communication circuit 12 receives the information, the setting unit 109 may set the period P indicated by the information as the period P of the digital signal transmitted by the transmission unit 103. In this case, the user can adjust the period of the digital signal according to the desired code error detection sensitivity.

[0063] Alternatively, the setting unit 109 may automatically set the period P of the digital signal transmitted by the transmitting unit 103 at a predetermined timing. This configuration can be realized, for example, as follows. Specifically, information indicating multiple periods P is stored in advance in a memory included in the control unit 100. At a predetermined timing, the setting unit 109 selects, from the multiple periods P, the longest period P that has not been set as the period P of the digital signal transmitted by the transmitting unit 103 after power is supplied to the control circuit 10. The setting unit 109 sets the selected period P as the period P of the digital signal transmitted by the transmitting unit 103. The evaluation unit 108 calculates the occurrence status of the bit error detected by the detection unit 107. If no bit error has occurred or if the cumulative value of the bit error is less than a predetermined value, the setting unit 109 shortens the period P of the digital signal transmitted by the transmitting unit 103. The predetermined timing may be, for example, a timing at which it is desired to increase the sensitivity of bit error detection, such as a timing when the instantaneous value of the bit error continues to be less than a first threshold for a predetermined period of time or more. The predetermined timing may be the timing when the detecting unit 107 detects a code error, or the timing when the circuit board 1 starts up. In this way, the setting unit 109 may set the period P of the digital signal transmitted by the transmitting unit 103 to be shorter in stages each time the predetermined timing is reached.

[0064] On the other hand, the setting unit 109 adjusts the resistance value of the resistive element 106 to adjust the amplitude A of the digital signal transmitted by the transmitting unit 103 .

[0065] Specifically, the setting unit 109 adjusts the resistance value of the resistive element 106 by outputting a signal indicating the resistance value of the resistive element 106 to the resistive element 106 .

[0066] For example, the greater the resistance value of resistive element 106, the smaller the amplitude A of the digital signal transmitted to communication wiring 11. The smaller the amplitude A of the digital signal transmitted to communication wiring 11, the greater the amount of change in amplitude A when affected by noise relative to amplitude A. Therefore, the smaller the amplitude A of the digital signal transmitted to communication wiring 11, the more likely the bit configuration of the digital signal is to change when affected by noise, and the higher the sensitivity to code error detection. For this reason, setting unit 109 sets amplitude A of the digital signal to a minimum value by inputting a signal indicating the maximum resistance value that can be set by resistive element 106 to resistive element 106. However, the amplitude A of the digital signal transmitted by transmitter 103, set by setting unit 109, is not limited to this.

[0067] For example, the processing unit 20 may acquire information indicating a resistance value that can be set by the resistive element 106, input by the user to the display device 3, and transmit the information to the circuit board 1. In response to this, when the communication circuit 12 receives the information, the setting unit 109 may input a signal indicating the resistance value indicated by the information to the resistive element 106, thereby setting the amplitude A of the digital signal. Alternatively, instead of the resistive element 106, a switching unit such as a rotary switch that switches between multiple resistors may be provided. In this way, the user may physically switch the resistors by operating the switching unit, thereby setting the amplitude A of the digital signal. In these cases, the user can adjust the amplitude of the digital signal according to the desired code error detection sensitivity.

[0068] Alternatively, the setting unit 109 may automatically set the amplitude A of the digital signal transmitted by the transmitting unit 103 at a predetermined timing. This configuration can be realized, for example, as follows. Specifically, information indicating multiple resistance values ​​that can be set by the resistive element 106 is stored in advance in a memory included in the control unit 100. At a predetermined timing, the setting unit 109 selects, from the multiple resistance values, the smallest resistance value that has not been selected for adjusting the amplitude A of the digital signal transmitted by the transmitting unit 103 after power is applied to the control circuit 10. The setting unit 109 adjusts the amplitude A of the digital signal transmitted by the transmitting unit 103 by inputting a signal indicating the selected resistance value to the resistive element 106. The evaluation unit 108 calculates the occurrence status of the bit error detected by the detection unit 107. If no bit error has occurred or if the cumulative value of the bit errors is less than a predetermined value, the setting unit 109 sets the amplitude A of the digital signal transmitted by the transmitting unit 103 to a high value. The predetermined timing may be, for example, a timing at which it is desired to increase the sensitivity of detecting a code error, such as a timing when the instantaneous value of the code error continues to be less than the first threshold value for a predetermined period of time or more. Alternatively, the predetermined timing may be a timing when the detecting unit 107 detects a code error, or a timing when the circuit board 1 starts up. In this way, the setting unit 109 may gradually increase the resistance value of the resistive element 106 at each predetermined timing, thereby gradually decreasing the amplitude A of the digital signal.

[0069] The setting unit 109 may be configured to variably set only one of the period and amplitude of the digital signal transmitted by the transmitting unit 103 .

[0070] Next, a description will be given of the display processing performed by the processing unit 20. The display processing is processing for displaying information received by the communication unit 21 on the display unit 22.

[0071] When the display device 3 is started up and power is supplied to the circuit board 1, the transmitter 103 starts transmitting a digital signal to the communication wiring 11. In response, the receiver 104 receives the digital signal from the communication wiring 11, the detector 107 detects any code errors occurring in the digital signal, and the evaluator 108 quantifies the occurrence of the code errors. The communication circuit 12 then transmits information about the code errors, including a numerical value indicating the occurrence of the code errors, to the processing unit 2, and when the communication unit 21 receives the information, the processor 20 starts a display process to display the information.

[0072] When the processing unit 20 starts the display process, it generates image data of an image showing the occurrence status of a code error based on the information received by the communication unit 21. The display unit 22 displays the image indicated by the image data input from the processing unit 20.

[0073] FIG. 4 is a diagram showing a first example of the display mode of the display unit 22. In the first example, an image G1 is displayed on the display unit 22. The image G1 includes a graph showing the occurrence status of code errors. The horizontal axis of the graph represents time, which corresponds to the detection time included in the information received by the communication unit 21. The vertical axis represents the number of bit errors. The bar graph shown with a solid line represents the instantaneous value of the number of bit errors, which corresponds to the instantaneous value of the code errors included in the information received by the communication unit 21. The line graph shown with a dashed line represents the cumulative value of the number of bit errors, which corresponds to the cumulative value of the code errors included in the information received by the communication unit 21. The display unit 22 is capable of displaying an image G1 relating to each of one or more circuit boards 1 provided in the display device 3.

[0074] FIG. 5 is a diagram showing a second example of the display mode of the display unit 22. In the second example, an image G2 is displayed on the display unit 22. The image G2 includes a table showing the occurrence status of code errors. The table includes the following items: "Time," "Number of Errors (Instantaneous Value)," "Number of Errors (Cumulative Value)," "Noise Level," and "Operation Information." The "Time" item corresponds to the detection time included in the information received by the communication unit 21. The "Number of Errors (Instantaneous Value)" item corresponds to the instantaneous value of the code errors included in the information received by the communication unit 21. The "Number of Errors (Cumulative Value)" item corresponds to the cumulative value of the code errors included in the information received by the communication unit 21. The "Noise Level" item corresponds to the noise influence level on the circuit board 1 included in the information received by the communication unit 21. The "Operation Information" item includes operation information (information related to the operation of the display device 3) at the detection time included in the information received by the communication unit 21. The processing unit 20 acquires the operation information at the detection time from the storage unit 23. The display unit 22 is capable of displaying an image G2 relating to each of one or more circuit boards 1 that the display device 3 has.

[0075] When the communication unit 21 receives information about a code error from the circuit board 1, the processing unit 20 executes a process of storing the information received by the communication unit 21 in the storage unit 23. Specifically, when the communication unit 21 receives information about a code error from the circuit board 1, the processing unit 20 stores the information in the storage unit 23 in association with operation information at the detection time included in the information.

[0076] In this way, in the display device 3 according to this embodiment, a digital signal is transmitted to the communication wiring 11 provided in advance on the circuit board 1, and a code error occurring in the digital signal received from the communication wiring 11 is detected. Then, the instantaneous value and cumulative value of the code error and the level of noise influence on the circuit board 1 are calculated as numerical values ​​indicating the occurrence status of the code error, and information including these numerical values ​​is displayed on the display unit 22.

[0077] Therefore, the user can easily determine whether the area near the communication wiring 11 on the circuit board 1 is affected by noise without using a measuring instrument such as an oscilloscope, and can quantitatively evaluate the impact of the noise based on the information displayed on the display unit 22.

[0078] Furthermore, by providing communication wiring 11 in advance in the vicinity of a wide area including the desired location on circuit board 1, the effects of noise in a wide area including the desired location on circuit board 1 can be efficiently measured without modifying or changing the layout of circuit board 1 during failure analysis after shipment, etc.

[0079] Furthermore, in the display device 3 according to this embodiment, information about code errors is associated with operation information and stored in the storage unit 23. This makes it possible to analyze in detail the causal relationship or correlation between the operation of the display device 3 and the influence of noise on the circuit board 1.

[0080] Next, an example in which the circuit board 1 described in the above embodiment is applied to an environment creating device will be described. FIG. 7 is a diagram showing the overall configuration of an environment creating device 1000 according to an embodiment of the present invention. The environment creating device 1000 includes an environment creating chamber 60 in which an object 62 to be tested or processed is housed, and an environment control unit 50 that controls the environment within the environment creating chamber 60. The environment creating chamber 60 is a chamber surrounded by a heat-insulating housing, and the object 62 is housed inside the chamber. The object 62 is, for example, an electronic component such as a circuit board. The environment creating device 1000 also includes a control device 110, a display 120 (information display unit), an electrical device 130, and a measuring device 150.

[0081] At least one electrical device 130 is installed within the environment control unit 50. At least a portion of the electrical devices 130 may be located outside the environment control unit 50. In this application example, multiple electrical devices 130 are installed within the environment control unit 50. The electrical devices 130 are devices that adjust the environment within the environment creating chamber 60. For example, the electrical devices 130 include a heating device that heats the air within the environment creating chamber 60. The electrical devices 130 also include a cooling device that cools the air within the environment creating chamber 60. The electrical devices 130 also include a humidifying device that humidifies the air within the environment creating chamber 60. The electrical devices 130 also include a refrigeration device or a dehumidification device that dehumidifies the air within the environment creating chamber 60. The electrical devices 130 control the temperature or the temperature and humidity of the environment within the environment creating chamber 60 under drive control from the control device 110.

[0082] The above configuration of the environment control unit 50 is an example, and can be changed depending on the object of controlling the environment in the environment creating chamber 60. For example, if the object of controlling the environment is only temperature, the environment control unit 50 may be configured using only a heating device. Furthermore, the environment control unit 50 may control the pressure of the environment in the environment creating chamber 60. In this case, the electrical equipment 130 may include a pressure reducing device and / or a pressure increasing device.

[0083] Power is supplied to each of the multiple electrical devices 130 via a contact or a relay such as an SSR (not shown). The relay is controlled by an output circuit 191 of the circuit board 1E provided in the control device 110. In other words, the output circuit 191 of the circuit board 1E controls the relay to control the power supply to the electrical devices 130. The control device 110 and the relay are disposed outside the environment control unit 50.

[0084] At least one measuring device 150 is installed outside the environment creating chamber 60. At least some of the measuring devices 150 may be located inside the environment creating chamber 60. In this application example, multiple measuring devices 150 are installed outside the environment creating chamber 60. A sensor 61, such as a temperature sensor, is installed inside the environment creating chamber 60. The measuring device 150 measures the environmental condition inside the environment creating chamber 60 or the condition of an object 62 placed inside the environment creating chamber 60. The measuring device 150 includes a circuit board 1F that measures the environmental condition inside the environment creating chamber 60 or the condition of an object 62 placed inside the environment creating chamber 60. The circuit board 1F includes a control circuit 10F, an input circuit 192, a communication circuit 12F, and communication wiring 11F. The communication wiring 11F is formed in advance as a wiring pattern on the circuit board 1F so as to be connected to the control circuit 10F in a circular shape. A sensor 61 is connected to the input circuit 192. The circuit board 1F has a configuration similar to that of the circuit board 1 (FIG. 1) included in the display device 3. That is, the circuit board 1 (FIG. 1) included in the display device 3 can be applied to the circuit board 1F.

[0085] The above configuration of the measuring device 150 is an example and can be changed as necessary. For example, the measuring device 150 includes a temperature sensor that measures the temperature of the environment in the environment creating chamber 60. The temperature sensor is configured using a thermocouple, a resistance temperature detector, or the like. The measuring device 150 may also include a temperature sensor that measures the temperature of a refrigeration circuit in the refrigeration device or dehumidification device of the environment control unit 50. In this case, the temperature sensor is disposed within the environment control unit 50, or disposed outside the environment creating chamber 60 and outside the environment control unit 50. The temperature sensor may be integrated with the measuring device 150 or may be separate.

[0086] Furthermore, for example, the measuring device 150 includes a humidity sensor that measures the humidity of the environment in the environment creating chamber 60. The humidity sensor is, for example, a resistance type or a capacitance type humidity sensor. The humidity sensor may be integrated with the measuring device 150 or may be separate.

[0087] Furthermore, for example, the measuring device 150 includes a pressure sensor that measures the pressure of the environment inside the environment creating chamber 60. The pressure sensor is configured using a pressure-sensitive element or the like, and measures the pressure inside the chamber when the environment creating chamber 60 is a vacuum chamber or the like. The measuring device 150 may also include a pressure sensor that measures the safety pressure of the refrigeration piping of the refrigeration device or dehumidification device of the environment control unit 50. In this case, the pressure sensor is placed outside the environment creating chamber 60 and outside the environment control unit 50. The pressure sensor may be integrated with the measuring device 150 or may be separate.

[0088] The electrical device 130 and the measuring device 150 may be affected by various noises, which may cause breakdowns or malfunctions of the environment creating device 1000. The noises include high-frequency noise coming from outside as radio waves, low-frequency noise coming from power lines, and single-shot noise caused by static electricity.

[0089] The control device 110 is configured using a microprocessor, a microcontroller, etc. The control device 110 includes a circuit board 1E that controls the electrical equipment 130 that adjusts the environment in the environment creating chamber 60, a memory unit 111 (information memory unit), a communication unit 112 (information receiving unit), and an information processing unit 113.

[0090] The circuit board 1E includes a control circuit 10E, an output circuit 191, a communication circuit 12E, and communication wiring 11E. The communication wiring 11E is formed in advance as a wiring pattern on the circuit board 1E so as to be connected to the control circuit 10E in a circular shape. The circuit board 1E has a configuration similar to that of the circuit board 1 (FIG. 1) included in the display device 3. That is, the circuit board 1 (FIG. 1) included in the display device 3 is applicable to the circuit board 1E. The memory unit 111 has a configuration similar to that of the memory unit 23 (FIG. 1) included in the processing unit 2 of the display device 3. The communication unit 112 has a configuration similar to that of the communication unit 21 (FIG. 1) included in the processing unit 2 of the display device 3. The information processing unit 113 has a configuration similar to that of the processing unit 20 (FIG. 1) included in the processing unit 2 of the display device 3. That is, the memory unit 23, communication unit 21, and processing unit 20 included in the processing unit 2 of the display device 3 are applicable to the memory unit 111, communication unit 112, and information processing unit 113 included in the control device 110.

[0091] The display device 120 has a configuration similar to the display section 22 (FIG. 1) included in the processing unit 2 of the display device 3. In other words, the display section 22 included in the processing unit 2 of the display device 3 is applicable to the display device 120 included in the environment forming device 1000.

[0092] The environment creating device 1000 evaluates the performance of the object 62 by applying temperature stress, or temperature stress and humidity stress, to the object 62. However, the environment creating device 1000 may be a heat treatment device or the like that performs heat treatment such as heating on the object 62, or may be a vacuum heating device or the like that performs pressure treatment such as reducing pressure on the object 62.

[0093] That is, in the environment creating device 1000, digital signals are transmitted to communication wiring 11E, 11F provided in advance on the circuit boards 1E, 1F, and code errors occurring in the digital signals received from the communication wiring 11E, 11F are detected by the control circuits 10E, 10F provided on the circuit boards 1E, 1F. Then, the control circuits 10E, 10F calculate instantaneous and cumulative values ​​of the code errors and the level of noise influence on the circuit boards 1E, 1F as numerical values ​​indicating the occurrence status of the code errors, and information including these numerical values ​​is input to the information processing unit 113 via the communication unit 112. As a result, the information processing unit 113 displays information indicating the numerical values ​​indicating the occurrence status of the code errors on the display 120.

[0094] Therefore, with the environment creating device 1000, it is possible to easily identify, without using a measuring instrument such as an oscilloscope, whether an area near the communication wiring 11E on the circuit board 1E constituting part of the control device 110 that controls the electrical equipment 130 that adjusts the environment in the environment creating chamber 60, or an area near the communication wiring 11F on the circuit board 1F constituting part of the measuring instrument 150 that measures the environmental conditions in the environment creating chamber 60 or the conditions of the object 62 placed in the environment creating chamber 60, is an area affected by noise. Furthermore, in failure analysis after shipping of the environment creating device 1000, the influence of noise on the areas near the communication wiring 11E, 11F on the circuit boards 1E, 1F can be efficiently measured without modifying or rearranging the circuit boards 1E, 1F and the electrical equipment 130. In this way, the control circuits 10E, 10F of the circuit boards 1E, 1F in the above-mentioned environment forming device 1000 combine the original functions of the circuit boards 1E, 1F, such as controlling the electrical equipment 130, with the function of evaluating the effects of noise on the circuit boards 1E, 1F.

[0095] The environment forming device 1000 may include one, three, or more circuit boards 1 having the function of evaluating the influence of noise, rather than two. For example, in the case of the environment forming device 1000 described above, at least one of the circuit board 1E constituting a part of the control device 110 and the circuit board 1F constituting a part of the measuring instrument 150 may include the control circuit 10, the communication wiring 11, and the communication circuit 12. Furthermore, at least one other circuit board included in the environment forming device 1000 may have the same configuration as the circuit board 1.

[0096] In the above embodiment, an example has been described in which the environment forming device 1000 is provided with the control device 110 and the measuring device 150 separately. However, this is not limiting, and for example, the control device 110 may be configured to have the same functions as the measuring device 150, so that the environment forming device 1000 does not include the measuring device 150. In this case, for example, the input circuit 192 may be arranged inside the communication wiring 11E and configured to be controlled by the control circuit 10E.

[0097] The above-described embodiment is merely an example of an embodiment according to the present invention, and is not intended to limit the present invention to the above-described embodiment. For example, the following modified embodiments may be used.

[0098] (1) In the above embodiment, an example has been described in which one communication wiring 11 is connected in a circular pattern to one control circuit 10 on the circuit board 1, as shown in Fig. 1 or 7. However, the number of communication wirings 11 connected in a circular pattern to one control circuit 10 is not limited to one, and may be two or more.

[0099] FIG. 6 is a diagram showing an example of the arrangement of multiple communication wirings 11. For example, FIG. 6 shows an example in which three communication wirings 11D1, 11D2, and 11D3 are connected in a ring shape to one control circuit 10D. The communication wiring 11D1 surrounds an area 13D1 on the circuit board 1D where an analog circuit is arranged, and is connected in a ring shape to the control circuit 10D. The communication wiring 11D2 surrounds an area 13D2 on the circuit board 1D where a power supply circuit is arranged, and is connected in a ring shape to the control circuit 10D. The communication wiring 11D3 surrounds an area where digital circuits, including an area 13D3 where a logic circuit is arranged, are arranged, and is connected in a ring shape to the control circuit 10D. In this case, the control circuit 10D is configured to include a resistive element 106, an insulating circuit 105, a transmitting unit 103, a receiving unit 104, and a control unit 100 (FIG. 2), which are connected to the three communication wirings 11D1, 11D2, and 11D3, respectively.

[0100] The analog circuit surrounded by communication wiring 11D1 is a circuit that processes analog signals indicating, for example, temperature measured using a thermocouple or humidity measured using a hygrometer. Because analog circuits process analog signals that change continuously over time, they are more susceptible to noise than the digital circuit surrounded by communication wiring 11D3, which processes digital signals that change discretely. The power supply circuit surrounded by communication wiring 11D2 is a circuit that supplies commercial power to display device 3 and cuts off the supply of that power. Therefore, low-frequency noise may be introduced into the area near the power supply circuit via commercial power receiving unit 18, and the low-frequency noise may affect the power supply circuit.

[0101] As in this modified embodiment, a plurality of communication wirings 11 are formed on the circuit board 1 so as to surround each of the plurality of circuits, and the control circuit 10 is configured to detect code errors occurring in areas near the communication wirings 11 surrounding each circuit. In this case, it is possible to identify which circuits on the circuit board 1 are affected by noise. In other words, it becomes easier to identify the noise source. Furthermore, taking into account the influence of noise on each circuit, the period and amplitude of the digital signal used to detect code errors can be adjusted for each circuit so that the code error detection sensitivity is appropriate for each circuit.

[0102] (2) The setting unit 109 may set the period and amplitude of the digital signal transmitted by the transmitting unit 103 to a predetermined period and amplitude at a predetermined timing, such as when power is first supplied to the control circuit 10, and then may not change the settings of the period and amplitude of the digital signal transmitted by the transmitting unit 103.

[0103] (3) The setting unit 109 may be configured to variably set only the period of the digital signal transmitted by the transmitting unit 103. Alternatively, the setting unit 109 may be configured to variably set only the amplitude of the digital signal transmitted by the transmitting unit 103.

[0104] (4) The processing unit 2 included in the display device 3 in Fig. 1 may be configured as part of the functions of, for example, a personal computer. That is, the display device 3 may be configured by a device on which the circuit board 1 is installed and the processing unit 2 communicatively connected to the device. The information processing unit 113 and the storage unit 111 in Fig. 7 may be configured as part of the functions of a personal computer communicatively connected to the environment forming device 1000. In this case, the environment forming device 1000 may or may not include the information processing unit 113 and the storage unit 111. [Explanation of symbols]

[0105] 1, 1A, 1B, 1C, 1D, 1E, 1F: Circuit board 10, 10A, 10B, 10C, 10D, 10E, 10F: Control circuit 103: Transmitter 104: Receiving unit 107:Detection unit 108: Evaluation Department 109: Setting section 11, 11A, 11B, 11C, 11D1, 11D2, 11D3, 11E, 11F: Communication wiring 12, 12A, 12B, 12C, 12E, 12F: Communication circuit (output circuit) 21: Communication unit (information receiving unit) 22: Display section (information display section) 3:Display device 60:Environment formation room 62: Object 110: Control device 111: Storage unit (information storage unit) 112: Communication unit (information receiving unit) 113: Information Processing Department 120: Display (information display section) 130: Electrical equipment 150: Measuring equipment 1000:Environment shaping device A: Amplitude P:period

Claims

1. A circuit board to be subjected to noise measurement, a control circuit; a communication wiring that is connected in a circular fashion to the control circuit and that is provided in advance on the circuit board; The control circuit a transmitter that transmits a predetermined digital signal to the communication line; a receiving unit that receives the digital signal from the communication line; a detection unit that detects a code error occurring in the digital signal received by the receiving unit, an output circuit that outputs information about the code error detected by the detection unit; The circuit board further comprises:

2. the control circuit further includes an evaluation unit that quantifies the occurrence of the code error detected by the detection unit, The information about the code error includes a numerical value indicating the occurrence status of the code error quantified by the evaluation unit. The circuit board according to claim 1 .

3. the control circuit further includes a setting unit that variably sets at least one of a period and an amplitude of the digital signal transmitted by the transmission unit. The circuit board according to claim 1 .

4. The circuit board according to any one of claims 1 to 3; an information receiving unit that receives the information output by the output circuit; an information display unit that displays the information received by the information receiving unit; A display device comprising:

5. The circuit board according to any one of claims 1 to 3; The Environmental Creation Office and Equipped with The circuit board constitutes at least a part of a control device that controls an electrical device that adjusts the environment in the environment creating chamber, or a part of a measuring device that measures the environmental condition in the environment creating chamber or the condition of an object placed in the environment creating chamber. Environment shaping device.

6. an information receiving unit that receives the information output by the output circuit; an information storage unit that stores information; an information processing unit that stores the information received by the information receiving unit in the information storage unit in association with information related to the operation of the environment forming device; The environment creating device according to claim 5 , further comprising:

7. A method for measuring noise on a circuit board, comprising: the circuit board includes a control circuit, a communication wiring that is connected to the control circuit in a circular manner and that is provided in advance on the circuit board, and an output circuit; The control circuit transmitting a predetermined digital signal to the communication line; receiving the digital signal from the communication line; Detecting a code error occurring in the received digital signal; The output circuit the control circuit outputs information about the detected code error; Method for measuring noise on circuit boards.

Images