JPH06123709A - Method for inspecting printed wiring board and device - Google Patents

Abstract

PURPOSE:To provide a method for efficiently inspecting a wiring pattern of a printed wiring board and a device used in its method. CONSTITUTION:In an inspector for a printed wiring board 1 utilizing an optical characteristic for the printed wiring board 1, using an optical type pattern inspection machine 2 for detecting a defect produced in a wiring pattern and the coordinate data and detection items of detection parts obtained therefrom and employing a defect confirmation machine 3 for confirmation the detection parts, defect number allowed on a specific defect production prohibition area and one face of the printed wiring board 1 is previously determined. In the case where the defect parts exist in the production prohibition area and specific item detection parts exceed the number allowed in one previously determined printed wiring board 1, these parts are inspected prior to other detected part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for inspecting printed wiring boards.

[0002]

2. Description of the Related Art A printed wiring board 1, as shown in FIG. 2, is composed of an insulating substrate 2 and a circuit conductor formed on the surface thereof, and is manufactured by removing unnecessary portions of a copper foil. A method of forming a circuit conductor and a method of forming a circuit conductor by electroless plating only in a necessary portion of the conductor circuit are known.

By the way, in such a printed wiring board, a defect occurs in the pattern due to the accuracy of jigs and tools at the time of manufacturing, a printing error at the time of forming a wiring pattern by printing, and the like. As shown, disconnection 5, chipping 6, tapering 7, pinhole 8, short circuit 9, residual copper 10, protrusion 1
Various defects such as 1 may occur.

As such a defect, a broken conductor circuit or a short circuit between circuits cannot operate normally as a circuit.
Of course, it must be eliminated, but circuit operation may not be performed normally even if a wire break or short circuit does not occur. For example, the width of the circuit conductor is narrower than the design value and cannot withstand the required current, and the interval between the conductor circuits is narrow so that the required withstand voltage cannot be obtained. In addition to this, there are cases in which the shape is not required to maintain the transmission characteristics in a high-speed circuit, and there are cases in which the error in the pattern shape is severe due to the mounting of electronic components.

As a method for detecting a defect in a printed wiring board, an image processing method is used.
It is disclosed in Japanese Patent Publication No. 29041 and Japanese Patent Publication No. 3-3384.

Conventionally, the inspection of the wiring pattern of the printed wiring board is completed by transferring the coordinates of the position detected by the optical pattern inspection machine and the detection items to the defect confirmation machine and performing confirmation work in the order of detection. It is a thing.

[0007]

By the way, in the printed wiring board, the disconnection or the chipping which has occurred in the line corner portion 12 and the through hole pad neck portion 13 as shown in FIG. 4 cannot be corrected. Even if the correction is approved, there is the allowable number of corrections. Conventionally, the confirmation work was performed by the confirmation device 3 in accordance with the order of detection by the optical pattern inspection device 2. However, in the conventional method, an uncorrectable defect may appear at the end of the confirmation work, which is inefficient.

It is an object of the present invention to provide a method for efficiently inspecting a wiring pattern on a printed wiring board and an apparatus used for the method.

[0009]

A method for inspecting a printed wiring board according to the present invention utilizes the optical characteristics of the printed wiring board,
An optical pattern inspecting machine 1 for detecting a defect generated in a wiring pattern, and a defect confirming machine 2 for confirming the detected place by using the coordinate data and the detected item of the detected place obtained by this are used. In a printed wiring board inspection device, a predetermined defect occurrence prohibited area and the number of defects allowed on one surface of the printed wiring board are set in advance, and a detection location exists in the occurrence prohibited area or a detection location of a specific item is detected. It is characterized in that when the number exceeds a predetermined number permitted for one printed wiring board, these places are confirmed with priority over other detected places.

The order of confirming the detection points is to give the highest priority to the points detected in the specific defect generation prohibited area, then to the predetermined specific defect permitted on one surface of the printed wiring board, and finally It can be a detection point in a predetermined inspection area.

As an apparatus which can be used for such a method, as shown in FIG. 1, in the conventional inspection apparatus which transfers the coordinates of the detection point and the detection item from the optical pattern inspection machine 1 to the confirmation machine 2, A device provided with a data editing machine 3 for editing the coordinates of the location and the detection item can be used.

In the present invention, it is preferable to use a personal computer of the optical pattern inspection machine in order to edit the optical pattern inspection machine, the confirmation machine, and the coordinates of the detection points and the data of the detection items.

[0013]

According to the method and apparatus of the present invention, the quality can be determined without checking all the detected locations, and the printed wiring board can be efficiently inspected.

[0014]

[Example] Coordinate data of a detection location is input from an optical pattern inspection machine. PC-9801EX for data editing device
2 was used as the program, and the program of the flowchart shown in FIG. 2 was used as the program of the flowchart shown in FIG. In the personal computer, set the area that stores the coordinates of the location detected in the specific defect occurrence prohibited area, the area that stores the coordinates of the location detected in the area other than the specific defect occurrence prohibited area, and the detection item, The coordinates of the location detected by the optical pattern inspection machine and the detection items are compared with the settings and stored in the respective areas. In order to accumulate the number of specific defects in an area other than the specific defect generation prohibited area and determine that the number exceeds the allowable number for one surface of the printed wiring board, it is necessary to correlate with the above-mentioned operation and execute the specific operation. Only add 1 to a specific storage area when a defect is detected,
A program is provided to determine whether the number exceeds the set value. Regarding the order of data sent to the confirmation device, the coordinate data of the location detected in the specific defect occurrence prohibited area has the highest priority, and then the coordinates and the location of the location detected in the area other than the specific defect occurrence prohibited area are detected. The items are the coordinates of the detection points other than those described above and the detection items that are finally detected in the inspection area.

[0015]

As described above, the present invention can provide a method for efficiently inspecting a printed wiring board and an apparatus used for the method.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention.

FIG. 2 is a flowchart showing a flow of a program used in an embodiment of the present invention.

FIG. 3 is a perspective view of a printed wiring board having a defect in a wiring pattern for explaining an embodiment of the present invention.

FIG. 4 is a top view of a printed wiring board having a wiring pattern defect for explaining one embodiment of the present invention.

[Explanation of symbols]

1. Printed wiring board 2. Optical pattern inspection machine 3. Confirmation machine 4. Data editor 5. Disconnection 6. Chip 7. Thinning 8. Pinhole 9. Short circuit 10. Residual copper 11. Protrusion 12. Line corner section 13. Through hole pad neck

Claims (5)

[Claims] 1. An optical pattern inspecting device for detecting a defect generated in a wiring pattern by using optical characteristics of a printed wiring board, and coordinate data and detection items of a detection position obtained by the optical pattern inspecting device. A method for determining a specific defect generation prohibited area in a predetermined inspection area in a printed wiring board inspection apparatus using a defect confirmation device for confirming a detection location. 2. The printed wiring board inspecting device according to claim 1, wherein the inspection work is prioritized when the detected location of the inspected printed wiring board is a specific defect generation prohibited area. . 3. An optical pattern inspecting device 2 for detecting a defect occurring in a wiring pattern by utilizing the optical characteristics of a printed wiring board, and coordinate data and detection items of detection points obtained by the optical pattern inspecting device 2. In a printed wiring board inspecting apparatus using a defect checking device 3 for checking a detection location, a method for determining the number allowed on one surface of the printed wiring board. 4. When the number of inspected printed wiring boards detected exceeds the number allowed on one surface of the printed wiring board, the purpose is to perform confirmation work prior to the detected areas in the inspection area. The printed wiring board inspection device according to claim 3. 5. An optical pattern inspection machine 2 is applied to a printed wiring board 1 to be inspected, and coordinate data and detection items of detection points obtained by the inspection are set in advance in a specific defect generation prohibited area and a printed wiring board. An inspection device for a printed wiring board, characterized in that the number of data permitted on one surface of a board is input to a data editing machine 4 and the output to a confirmation machine is controlled.