JP3209944B2 - Method and device for detecting malfunctioning part of circuit mounted printed circuit board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for detecting a malfunctioning portion of a circuit board, which detects which component or pattern is vulnerable to noise and which phenomenon causes malfunction in the circuit board. .

[0002]

2. Description of the Related Art Conventionally, (a) an international standard (such as IEC1000-4-2) which is a noise resistance test method for electronic equipment.
A method of performing a direct discharge to the housing of an electronic device, an indirect discharge to a horizontal coupling plate or a vertical coupling plate, and the like to evaluate noise resistance as a product. (B) A method in which an impact magnetic field adapter or an impact electric field adapter is attached to a discharge gun of an electrostatic discharge tester and applied close to a specimen. (C) A method of analyzing the location and mechanism of occurrence of malfunction by scanning in the X and Y directions near the circuit-mounted printed circuit board and adding noise locally using a loop antenna or the like. (D) Using an EMS probe, apply the noise by manually approaching the probe to an arbitrary portion of a circuit-mounted printed circuit board or wiring, and search for the weakest portion by adjusting the output of the noise generator. A method of using a large flat-plate probe to quickly find a rough place and replacing it with a smaller probe to limit the weak points. and so on.

[0003]

However, in the case of the above (a), although a product can be tested, it is difficult to specify which part of the apparatus is vulnerable to noise. In the case of the item (b), even if a rough place that is vulnerable to noise can be grasped, since there is no mechanism for performing accurate positioning, test reproducibility is poor, and a precise place, distribution, countermeasure effect, and the like are grasped. It is difficult. In the case of the item (c), the applied noise level is constant, and the place where the malfunction has occurred is expressed as a solid error map, and only the information that the malfunction has occurred or not has been performed. It is difficult to determine if there is. Further, since there is no information on the malfunction phenomenon, it is difficult to grasp the distribution of each phenomenon when there are a plurality of malfunction factors. In the case of the item (d), as in the case of the item (b), although a rough position of a portion that is vulnerable to noise can be grasped, since there is no mechanism for performing accurate positioning, the reproducibility of the test is poor and the accurate position is poor. It is difficult to grasp the distribution, countermeasures and effects.
Note that an electronic circuit (circuit-mounted printed circuit board) that actually malfunctions is inside the product, and is considered to malfunction due to capacitive coupling, electromagnetic coupling, external electromagnetic waves, or the like from the panel surface or the housing. In addition, the circuit mounting printed board is a CPU
, And external noise may directly enter the device or may enter the pattern as a receiving antenna. Therefore, as a method of improving noise resistance (immunity measures), there is a method of adding a shield plate to a place susceptible to electromagnetic waves, strengthening the ground, adding noise suppression parts, changing the pattern, etc. In order to effectively perform the above, it is important to find out which part of the printed circuit board is vulnerable to noise and to investigate why it malfunctions. For this reason, in the present invention, which component or pattern is vulnerable to noise in a circuit mounting printed board and what kind of malfunction occurs in the circuit mounting printed board by grasping the malfunction voltage and the malfunction phenomenon at each coordinate on the circuit mounting printed board. The present invention provides a method and an apparatus that can easily detect whether or not there is a difference.

[0004]

In view of the above, the present inventor has made intensive studies and as a result, has solved the problem by the following means. (1) It comprises an input / output section for operation of a circuit-mounted printed board, a noise scanning section, a noise generating section and a data processing section, and the noise scanning section has a circuit-mounted printed board mounting plate surface. , fitted with a noise applying probe contact close to the lower side of the substrate mounting plate surface, also said the data processing unit by using the malfunction location detecting apparatus of the circuit mounting printed circuit board made comprises a malfunction distribution diagram display region, all malfunction phenomenon generated by by scanning the circuit mounting printed circuit board of the device under test mounted on a circuit mounting printed circuit board mounting plate surface in noise applying on the probe to locally discharge, the circuit mounting printed circuit board A malfunction distribution detection method for a circuit-mounted printed circuit board, wherein the malfunction distribution diagram is displayed on a malfunction distribution diagram display section as a malfunction distribution diagram. (2) An input / output section for operation of a circuit-mounted printed board, a noise scanning section, an image input section, a noise generating section and a data processing section, wherein the noise-scanning section includes a circuit-mounted printed board. comprising a mounting plate surface, fitted with a noise applying probe contact close to the lower side of the substrate mounting plate surface, also said the image input unit includes an image input means for capturing a mounting circuit pattern on the circuit mounting printed circuit board, Further, the data processing unit uses a circuit mounting pattern display unit that displays a mounting circuit pattern diagram captured from an image input unit and a malfunction distribution diagram display unit that includes a malfunction distribution diagram display unit. Te, locally release by scanning the circuit mounting printed circuit board of the device under test mounted on a circuit mounting printed circuit board mounting plate surface in noise applying on the probe The circuit mounting printed circuit board characterized in that all the malfunctioning phenomena caused by the above are displayed as a malfunction distribution situation diagram on the circuit mounting printed board, overlaid on the circuit mounting pattern display section on the malfunction distribution diagram display section. Malfunction detection method. (3) The malfunction distribution diagram display section displays the malfunction distribution status as multi-level lightness / darkness (1).
A method for detecting a malfunctioning portion of a circuit-mounted printed circuit board according to the paragraph (2) or (2). (4) The method of detecting a malfunction of a circuit-mounted printed circuit board according to the above mode (1) or (2), wherein the malfunction distribution is displayed on the malfunction distribution diagram display section as a different color. (5) In the malfunction distribution diagram display section, the malfunction distribution status is displayed as a malfunction voltage and a malfunction identification code, and the circuit mounting printed board according to any one of the above modes (1) to (4) is characterized in that: Malfunction detection method.

[0005] (6) as a noise applied probe, it employs a metal plate smaller size than the circuit mounting printed circuit substrate placed in proximity to the circuit mounting printed board, local noise by adding an electrostatic discharge to the metal plate The method for detecting a malfunctioning portion of a circuit-mounted printed circuit board according to any one of the above modes (1) to ( 5 ), wherein ( 7 ) In the noise application probe, a large size probe is used to apply a wide range of noise to grasp a rough malfunction distribution of the entire circuit mounting printed circuit board. A method for detecting a malfunctioning portion of a circuit-mounted printed circuit board according to any one of the above modes (1) to ( 7 ), wherein a test is performed to narrow down a location vulnerable to noise efficiently. ( 8 ) An input / output unit for operation of a circuit-mounted printed circuit board, a noise scanning unit, a noise generating unit and a data processing unit, wherein the noise scanning unit includes a circuit-mounted printed circuit board mounting plate surface, near contact with noise applied probe below the substrate mounting plate surface attached, also,
An apparatus for detecting a malfunctioning part of a circuit-mounted printed circuit board, wherein the data processing part includes a malfunction distribution diagram display part. ( 9 ) It comprises an input / output section for operation of a circuit-mounted printed board, a noise scanning section, an image input section, a noise generating section and a data processing section, and the noise scanning section is mounted on the circuit-mounted printed board. a plate surface, fitted with a noise applying probe contact close to the lower side of the substrate mounting plate surface, also said the image input unit includes an image input means for capturing a mounting circuit pattern on the circuit mounting printed circuit board, and Further, the data processing section includes a circuit mounting pattern display section for displaying a mounting circuit pattern diagram captured from an image input section, and a malfunction distribution map display section. Detection device. (10) The malfunction distribution diagram display unit, characterized by comprising a display mechanism for displaying malfunction distribution as shading brightness of multistage (8) or (9) the circuit mounting printed circuit board according to claim Malfunction detection device. ( 11 ) The malfunction distribution diagram display section is provided with a display mechanism for displaying the malfunction distribution status as a different color, and the malfunction location of the circuit mounting printed circuit board according to the mode ( 8 ) or ( 9 ). Detection device. (12) The malfunction distribution diagram display unit, characterized by comprising a display mechanism for displaying malfunction distribution as malfunction voltage and malfunction identification code (8) through section (11)
A device for detecting a malfunctioning part of a circuit-mounted printed circuit board according to any one of the above items. (13) as a noise applied probe, either to (8) no claim, characterized by comprising employing a metal plate of smaller size than the circuit mounting printed circuit substrate placed in proximity to the circuit mounting printed circuit board (12) section 3. A malfunction detecting device for a circuit-mounted printed circuit board according to claim 1. ( 14 ) A malfunction of the circuit-mounted printed circuit board according to any one of ( 8 ) to ( 13 ), wherein the noise applying probe includes a large-sized probe and a smaller-sized probe. Location detection device.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the accompanying drawings.

[0007]

FIG. 1 is a schematic explanatory view showing the device configuration of an embodiment of the present invention. In the figure, S is a noise scanning unit, G is an image input unit, K is a noise generation unit, and D is a data processing unit. FIG. 2 is a schematic diagram showing a device configuration of the embodiment of the present invention. In the figure, 1 is a board mounting plate surface, 1 'is a square, 2 is an application probe, 3 is a discharge gun, 4 is a circuit-mounted printed board, 5 is an automatic static elimination probe, 6 is an electrostatic discharge tester, and 7 is a personal computer. , 8 is a CRT display, 9 is a color printer, and 10 is a digital camera. First, the noise scanning unit S will be described. The noise scanning unit S is made of a wooden or PVC box that is hardly affected by electromagnetic waves, and the upper surface of the box is a circuit mounting printed circuit board mounting plate surface 1, and a noise application probe is provided at the center of the substrate mounting plate surface 1. Fix 2 On the entire surface of the substrate mounting plate surface 1, squares 1 'indicating XY coordinates at intervals of 1 cm are written. By scanning the printed circuit board 4 itself, local noise is added to the printed circuit board 4. The scanning of the circuit-mounted printed circuit board 4 is realized by an operator manually moving the circuit-mounted printed circuit board 4 along the cell 1 '. Note that the scan may be instructed by a personal computer and automatically performed via a motor control board.

Next, the noise generator K will be described.
The noise generator K is composed of an electrostatic discharge tester, a discharge gun, a noise application probe, an automatic static elimination probe, a GP-IB board, and the like (FIG. 1). used. The noise applying probe 2 includes a 9 cm square, a 3 cm square, and a 1 cm square metal plate (hereinafter referred to as a 9 cm probe, a 3 cm probe, and a 1 cm square, respectively).
(Referred to as probes hereinafter). When one of the three metal plates is attached to the discharge gun 3 of the electrostatic discharge tester 6 and discharged, the noise is applied as local noise to the circuit board 4.

Next, the image input unit G will be described. An image of the printed circuit board 4 is photographed by the digital camera 10, captured by the personal computer 7, and displayed on the display 8 as necessary.

In the data processing section D, an electrostatic discharge tester 6
Control, recording of malfunction voltage and malfunction contents at each coordinate, display of analysis results, printing, and the like. The malfunction status at each point is indicated by a six-step color frame corresponding to the malfunction voltage, as well as the malfunction voltage value and the identification code of the malfunction content. At this time, the image is superimposed on the image of the printed circuit board 4 and displayed.

Next, an example of the configuration of the analysis screen according to the above configuration is shown in a schematic diagram. FIG. 3 is a schematic diagram showing a configuration of an analysis screen in the embodiment of the device of the present invention. The screen is obtained by capturing an image of the circuit-mounted printed circuit board 4 with the digital camera 10, capturing the captured image in the personal computer 7, and displaying it on the display 8. That is, the file name, measurement (S), display (V), conversion,
Each symbol of the difference display, the comment on the upper right, the comment: No measure, the test conditions (interval 1 second, 10 repetitions, 1 test) are displayed, and the upper right arrow indicates the Y-axis coordinate, and the lower left arrow indicates the X-axis coordinate. The image of the specimen is indicated by an arrow pointing down the center, and the measurement date and time and the maximum level (7.00
kv), the minimum level (1.00 kv), and the malfunction voltage level (7-1 kv) and the corresponding step divisions are indicated by arrows.

Below that, a malfunction phenomenon list (RST7.5 interrupt, RAM contents destruction, register contents destruction, reset status, 〃∩〃 display)
RST6.5 5.5 interrupt etc.) is displayed. The screen is divided into 12 cases in which a 9 cm square probe is used as the noise applying probe on the circuit board. Further, in the section of the screen, a malfunction voltage 6.0, an identification code, and the like are displayed, and the malfunction voltage level is indicated by a color frame (the six colors). Therefore, various factors can be easily specified by looking at the screen or printed matter.

FIGS. 4 to 6 are schematic diagrams showing a malfunction distribution of the circuit board. The result of using a square noise application probe for a certain area of the circuit mounting printed circuit board is the same as the minimum value of the malfunction voltage during the test with the same area divided by a smaller size noise application probe. The value of + d is almost the same or the value of + d is shown, and the malfunction is almost the same. If this noise applying probe is used, the malfunction voltage or malfunction of the portion most vulnerable to noise within the applied range can be specified. After adding the noise over a wide area with the probe and understanding the rough malfunction distribution of the entire circuit mounted printed circuit board, test the area that was vulnerable to noise with a probe on the smaller side to narrow down the area that is vulnerable to noise Can be performed efficiently. The figure below shows test results using large, medium, and small probes, showing the above state. In the figure, FIG. 4 shows the test results with the 9 cm square probe, and FIG.
Shows the test results with a 3 cm □ probe, and FIG. 6 shows the test results with a 1 cm □ probe. The numbers displayed in the sections in the above-mentioned figure are the malfunction voltage and the identification code described in FIG. 3, and for example, 3.0 and the like are displayed above and below.

Next, the operation procedure of the device of the present invention will be described. The probe 2 for noise application used in the test
The size of the probe 2 to be used is fixed to the center of the probe, and the size of the probe 2 to be used is selected from 9 cm □ probe, 3 cm □ probe and 1 cm □ probe according to the purpose of the test. The circuit-mounted printed board 4 to be tested is set on the board mounting board surface 1, and a power supply, a signal, and the like are applied to keep the board in an operating state. deep. Next, the discharge voltage,
Input the discharge conditions such as the number of times of application, the lowest applied voltage and the highest applied voltage, and test conditions such as the scan range, interval, and probe size.

When the test is started, the application coordinates of the noise application probe 2 are displayed on the display 8, so that the operator can manually set the circuit mounting printed circuit board 4 to the specified coordinates.
Is set. Next, noise application is started. Noise is applied repeatedly at a specified minimum applied voltage for a specified number of times. As a result, if no malfunction occurs, noise application is repeated while increasing the voltage at specified intervals until the specified maximum applied voltage is reached. In addition, the electric charge stored in the printed circuit board 4 is periodically discharged by the automatic discharge probe 5. Further, the malfunction is determined by the operator, and when it is determined that the malfunction has occurred, the malfunction is registered in the malfunction phenomenon list displayed on the display 8 and the malfunction voltage and the identification code indicating the malfunction are entered. Record.

Next, in order to test the board, the printed circuit board 4 mounted on the board is returned to a normal operation state by, for example, turning the power on again. Since the next applied coordinates are displayed on the display 8, the printed circuit board 4 is set at the designated coordinates, and the same test as above is performed. When a malfunction occurs, if it is a malfunction that has already been registered in the malfunction phenomenon list, record its identification code.If it has not been registered, add it to the list as a new malfunction phenomenon and add it. Record the identification code assigned to the event. The malfunction status at each point is displayed in a six-step color frame corresponding to the malfunction voltage, and the malfunction voltage value and the identification code of the malfunction content are displayed. At this time, by superimposing and displaying the image of the circuit mounted printed circuit board 4 obtained from the image input unit, which components or patterns on the board are vulnerable to noise,
It is possible to easily identify what kind of phenomenon causes a malfunction.

[0017]

As described above, according to the method and the apparatus for detecting a malfunctioning portion of a circuit-mounted printed board according to the present invention, the following excellent effects are exhibited. 1, close to the solid boss was noise injection probes, upwards
Mounting the circuitry mounted printed circuit board, to control the shaft moves to scan the circuit mounting printed circuit board by adding a local noise, malfunction voltage malfunction phenomena in each coordinate, malfunction distributions on the circuit mounting printed circuit board By displaying the image on the display unit and overlaying the image of the circuit mounted printed circuit board, it is possible to identify parts and patterns that are vulnerable to noise, so that noise countermeasures such as selecting parts and reviewing patterns are more efficient. Can be settled. 2. In the malfunction distribution diagram display section, the malfunction distribution status is displayed as multi-level lightness or different colors, and is also displayed as a malfunction voltage and a malfunction identification code, so that the distribution of malfunction phenomena can be easily grasped. be able to. 3. By applying electrostatic discharge to a metal plate smaller than the printed circuit board as a noise application probe, local noise can be generated. Can be grasped efficiently. 4. Add noise over a wide area with a large-sized probe to understand the approximate malfunction distribution of the entire circuit-mounted printed circuit board, and then test the area that was vulnerable to noise with a probe on the smaller side to reduce noise. It is possible to efficiently narrow down a weak place. As described above, according to the present invention, noise countermeasures in a circuit-mounted printed circuit board can be efficiently implemented, and the effect greatly contributes to industry.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing the configuration of a device in an embodiment of the present invention.

FIG. 2 is a schematic view showing a configuration of a device in an embodiment of the present invention.

FIG. 3 is a schematic diagram showing a configuration of an analysis screen in the embodiment of the device of the present invention.

FIG. 4 is a schematic diagram showing a malfunction distribution of a circuit-mounted printed circuit board, and a test result diagram with a 9 cm square probe.

FIG. 5 is a schematic diagram showing a malfunction distribution of a circuit-mounted printed board, and a test result diagram using a 3 cm square probe.

FIG. 6 is a schematic diagram showing a malfunction distribution of a circuit-mounted printed board, and a test result diagram with a 1 cm square probe.

[Explanation of symbols]

S: Noise scanning part G: Image input part K: Noise generating part D: Data processing part 1: Board mounting plate surface 1 ': Square 2: Noise applying probe 3: Discharge gun 4: Circuit mounted printed circuit board 5: Automatic static elimination Probe 6: Electrostatic discharge tester 7: PC 8: Display 9: Color printer 10: Digital camera

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-43409 (JP, A) JP-A-8-233887 (JP, A) Hiroshi Omae, Yoji Nagasawa, "Printing with an Electrostatic Discharge Tester" Method of Detecting Malfunctions of Substrate ”, Television Institute Technical Report (wireless / optical transmission), The Institute of Television Engineers of Japan, December 1996, pp. 1-6 (58) Fields surveyed (Int. Cl. ^7, DB name) G01R 31/00 G01R 29/08

Claims (14)

(57) [Claims] An input / output unit for operating a circuit-mounted printed circuit board, a noise scanning unit, a noise generating unit and a data processing unit, wherein the noise scanning unit includes a circuit-mounted printed circuit board mounting plate surface. the provided, fitted with a noise applying probe contact close to the lower side of the substrate mounting plate surface, also in the data processing unit using the malfunction location detecting apparatus of the circuit mounting printed circuit board made comprises a malfunction distribution diagram display region All malfunctions caused by locally discharging the circuit-mounted printed circuit board of the device under test mounted on the surface of the circuit-mounted printed circuit board mounting board by using a noise applying probe , A method for detecting a malfunctioning portion of a circuit-mounted printed board, wherein the malfunctioning distribution is displayed on a malfunction distribution diagram display section as a malfunction distribution diagram on the board. 2. An input / output unit for operation of a circuit-mounted printed circuit board, a noise scanning unit, an image input unit, a noise generation unit and a data processing unit, wherein the noise scanning unit includes a circuit mounting unit. comprising a printed circuit board mounting plate surface, fitted with a noise applying probe contact close to the lower side of the substrate mounting plate surface, also an image input means for capturing a mounting circuit pattern on the circuit mounting printed circuit board in the image input unit A device for detecting a malfunction of a circuit-mounted printed circuit board, wherein the data processing unit includes a circuit-mounted pattern display unit for displaying a mounted circuit pattern diagram captured from an image input unit and a malfunction distribution diagram display unit using, by scanning the circuit mounting printed circuit board of the device under test mounted on a circuit mounting printed circuit board mounting plate surface in noise applying on the probe topical Circuit mounting characterized in that all malfunctioning phenomena caused by discharging to the circuit mounting printed circuit board are superimposed on the circuit mounting pattern display on the malfunction distribution diagram display as a diagram of the distribution of malfunctions on the printed circuit board. A method for detecting malfunctioning parts on printed circuit boards. 3. The method according to claim 1, wherein the malfunction distribution diagram display section displays the malfunction distribution status as multi-level lightness and darkness. 4. The method according to claim 1, wherein a malfunction distribution status is displayed as a different color on the malfunction distribution diagram display section. 5. A malfunction location of a circuit board according to claim 1, wherein a malfunction distribution status is displayed as a malfunction voltage and a malfunction identification code on the malfunction distribution diagram display section. Detection method. 6. As a noise applying probe, a metal plate having a size smaller than that of a circuit mounting printed board installed close to the circuit mounting printed board is adopted, and local noise is applied by applying an electrostatic discharge to the metal plate. malfunction portion detection method of the circuit mounting printed circuit board according to any one of claims 1, characterized in that to generate 5. 7. In a noise applying probe, a large-sized probe adds noise over a wide area to grasp a rough malfunction distribution of the entire circuit-mounted printed circuit board.
2. The method according to claim 1, wherein a test is performed with a probe having a smaller size in a range that is susceptible to noise, thereby narrowing down a location susceptible to noise.
7. A method for detecting a malfunctioning portion of a circuit-mounted printed circuit board according to any one of claims 6 to 6 . 8. An operation input / output unit for a circuit-mounted printed circuit board, a noise scanning unit, a noise generating unit and a data processing unit, wherein the noise scanning unit is provided on a surface of the circuit-mounted printed circuit board mounting plate. provided, fitted with a noise applying probe contact close to the lower side of the substrate mounting plate surface, also malfunction locations of the circuit mounting printed circuit board, characterized in that the said data processing unit comprising comprises a malfunction distribution diagram display region Detection device. 9. A circuit mounting printed circuit board comprising: an operation input / output unit; a noise scanning unit; an image input unit; a noise generation unit and a data processing unit; comprising a substrate mounting plate surface, fitted with a noise applying probe contact close to the lower side of the substrate mounting plate surface, also said the image input unit includes an image input means for capturing a mounting circuit pattern on the circuit mounting printed circuit board The data processing unit further includes a circuit mounting pattern display unit that displays a mounting circuit pattern diagram captured from an image input unit and a malfunction distribution diagram display unit. Malfunction location detection device. 10. The malfunction distribution diagram display unit, the circuit mounting printed circuit board according to claim 8 or 9, wherein the comprising a display mechanism for displaying malfunction distribution as shading brightness multistage malfunction locations Detection device. 11. The malfunction distribution diagram display unit, malfunctions distribution malfunction location detecting apparatus of the circuit mounting printed circuit board according to claim 8 or 9, wherein the comprising a display mechanism for displaying the heterologous color. The 12. malfunction distribution diagram display unit, to claims 8, characterized by comprising a display mechanism for displaying malfunction distribution as malfunction voltage and malfunction identification code 1
A device for detecting a malfunctioning portion of a circuit-mounted printed circuit board according to any one of the preceding claims. As 13. Noise applying probe, either of claims 8, characterized by comprising employing a metal plate of smaller size than the circuit mounting printed circuit substrate placed in proximity to the circuit mounting printed circuit board 12 A malfunction detecting device for a circuit-mounted printed board according to the above. 14. The noise applied probe, the circuit mounting printed circuit board of the malfunction location detection according to any one of claims 8 to 13, characterized in that it comprises a large size of the probe and a smaller size of the probe apparatus.