Hitachi, Ltd.

Koichi Karasaki

Yasuhiko Hara

Hideaki Doi

Akira Sase

Noriaki Ujiie

Keiya Saito

Mamoru Kobayashi

Tadashi Iida

Yoko Suzuki

An X-ray inspection apparatus and method in which an object to be inspected is irradiated with characteristic X-rays containing at least one wavelength which affords a high X-ray absorbance in the object to be inspected. A transmitted X-ray image which has passed through the object to be inspected is detected, and the object to be inspected is inspected on the basis of the transmitted X-ray image. The method and apparatus are utilized to fabricate a multi-layer printed circuit board.

X-ray inspection method and apparatus, prepreg inspecting method, and

A method and apparatus for detecting a circuit pattern comprise a stage for mounting an object under inspection having a circuit pattern to be detected, means of generating a signal in response to the amount of movement of the stage, a detection optical system for detecting the circuit pattern, an opto-electric transducer which receives the image of the pattern provided by the detection optical system and transforms the image into an image signal, means of calculating the amount of expansion or contraction of the object by detecting the distance between specific patterns on the object, and drive control means which produces a clock signal for the opto-electric transducer based on the stage movement signal provided by the signal generation means and varies the clock signal so as to vary the dimension of the detected image arbitrarily.

Method and apparatus for detecting a circuit pattern

A printed wiring board circuit-pattern inspection system including a two-dimensionally movable table on which a reference printed wiring board and a printed wiring board to be inspected are placed one after another; an image pickup unit which picks up an image of a circuit-pattern on a printed wiring board by scanning the circuit-pattern in two dimensions, and converting the image into a video signal, a binary pixel forming unit which transforms the video signal into binary pattern data, synchronous signal generator which generates a synchronous signal in synchronism with the scanning operation, a first buffer memory which stores binary pattern data, compressed pattern data memory which stores compressed binary pattern data of a whole reference printed wiring board, data compander which compresses and expands binary pattern, in accordance with the synchronous signal, a second buffer memory which stores, binary pattern data compressed by the data compander and the binary data retrieved from the compressed pattern data memory, and a comparator which compares the reference binary pattern data retrieved from the first buffer memory with the binary pattern data of the board under inspection the synchronous signal thereby providing indication of a defect in the board under inspection.

Pattern inspection system

Method and apparatus for detecting wiring patterns wherein a printed circuit board is irradiated with a light ray which excites a substrate of the printed circuit board to generate a fluorescent radiation from the substrate, the fluorescent radiation generated from portions other than a wiring pattern of the printed circuit board is imaged by means of an image detector, and a negative pattern of the wiring pattern is detected on the basis of an image signal generated from the image detector.

Method and apparatus for detecting wiring patterns

A method and an apparatus for testing the pattern of a printed circuit board, comprising a stroboscope for emitting intermittent light synchronously with the feed velocity of the printed circuit board; a condenser lens for gathering the intermittent light emitted from the stroboscope and irradiating the gathered light to the printed circuit board; a filter for converting the light of the stroboscope to exciting light; a half mirror for reflecting the exciting light gathered by the condenser lens and converted by the filter, then projecting the reflected light upon the printed circuit board perpendicularly thereto, and passing the excited fluorescent light from the substrate of the printed circuit board; an imaging lens for forming an image of the fluorescent light passed through the half mirror; another filter for eliminating any other light than the fluorescent light out of the entire light passed through the half mirror; a TV camera for picking up the fluorescent image formed by the imaging lens; a memory for storing the preceding-frame pattern video signal obtained from the TV camera with the stroboscope turned on and attenuated by an amount corresponding to the afterimage component; a circuit for subtracting the attenuated stored pattern video signal from the present-frame pattern video signal obtained from the TV camera with the stroboscope turned on; a circuit for generating a reference pattern; and a circuit for producing a negative pattern of the wiring pattern from the output signal of the subtracting circuit and comparing the negative pattern with the reference pattern. In this invention, the image of the printed circuit board set on the table in continuous motion is picked up by the TV camera without any harmful influence of the afterimage so that the printed circuit board can be properly checked to ascertain whether the wiring pattern thereof is normal or not.

Method and apparatus for testing pattern of a printed circuit board

A pattern detecting apparatus for inspecting a printed wiring board is disclosed in which a fluorescent image formed by the fluorescent light from the substrate of the printed wiring board and an image formed by the reflected light from the wiring pattern of the printed wiring board are both used because a wiring material which is left on an undesired portion of the substrate and has low reflectivity, is detected only at the fluorescent image and a defective portion of the wiring pattern where a surface layer thereof peels off, is detected only at the image formed by the reflected light, the image used for detecting the above defective portion is preferably formed by the reflected infrared light from the wiring pattern for the reason that infrared light is insensitive to a shallow flaw in the surface of the wiring pattern, and the fluorescent image and the infrared image are processed by a detection circuit, and then compared with each other to detect a pattern defect on the basis of a difference between the images thus processed.

Pattern detecting apparatus

A method for the alignment of electronic components to be mounted on a printed board. The alignment is accomplished by illuminating the surface of the printed board to cause emission of fluorescent light from the substrate of the printed board, detecting the fluorescent light by optical means to detect an image of the conductor pattern of the printed board as a negative picture, taking an image of leads of an electronic component by optical means as a positive or negative picture, and correcting the deviation of the leads of the electronic component from the conductor pattern on the basis of picture data obtained from both images.

Component alignment method

In order to optically inspect wiring patterns on a printed wiring board, laterally travelling light rays are passed through a half reflecting mirror disposed above the printed wiring board so as to be directed downwardly, thereby illuminating a wiring surface of the printed wiring board with the light normal thereto and at the same time light is directed at a large incident angle to the wiring surface through, for example, optical glass fibers to illuminate the wiring surface, whereby a corner which is a part of the wall defining a plated through hole formed in the printed wiring board can be detected as an accurate optical image, thus ensuring a highly accurate inspection of the wiring patterns.

Method and apparatus for inspecting printed wiring boards

In order that a slight positional deviation of a plated through hole such as having no substantial effect on the function of wiring should not be optically detected as a defect in a printed wiring board, the plated through hole is recognized as a part of the wiring pattern by making light representative of the plated through hole nearly equal in intensity to reflected light from the wiring pattern. This is achieved by illuminating the printed wiring board with light from the back side or by placing a reflector on the back side of the printed wiring board.

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Hadano, Japan

Koichi Karasaki