JPH0729483Y2 - Mounted printed circuit board automatic inspection device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention was formed on a mounted printed circuit board by sweeping a narrowed beam of laser light or the like on the mounted printed circuit board and soldering failure. The present invention relates to a mounted printed circuit board automatic inspection device that automatically detects the presence or absence of a bridge or solder funnel (soldering defect).

[Conventional technology]

Conventionally, as a method of detecting a bridge due to poor soldering on a mounted printed circuit board, a head having a large number of pins arranged in accordance with the component holes of the printed circuit board is used.
There is a contact inspection method in which a pin is brought into contact with a solder surface of a printed circuit board to be inspected by this head and a defective portion is detected by a conduction state between the pins.

However, in this method, it is necessary to prepare a head for each different type of printed circuit board, and the distance between the pins of the head is limited by the thickness of the pins.
There is a problem that it is difficult to inspect a printed circuit board having a dense pattern such as a printed circuit board on which an IC chip having a close chip lead interval is mounted.

In order to solve the above problems, a beam such as a laser beam is scanned to sweep the beam on the printed circuit board to be inspected, and the sputtered light (reflected light) of this beam is detected to solder parts such as bridges. There have been proposed various non-contact type mounted printed circuit board automatic inspection devices for inspecting, for example, JP-A-57-165704, JP-A-57-196140, and JP-A-
It is disclosed in Japanese Patent Publication No. 61-76940. Further, regarding a method of inspecting the surface condition of a printed circuit board or the like, there are those disclosed in JP-A-53-87258, JP-A-53-146171, and JP-A-61-114307.

[Problems to be solved by the invention]

In each of the above-mentioned devices that irradiate a beam on the printed circuit board to be inspected and detect sputtered light to perform inspection such as bridge detection, the device is complicated, and the soldering part for mounting components However, there are inconveniences such as not being suitable for recognizing the shape of the solder surface or being difficult in principle.

In order to recognize the shape of the soldered surface of the mounted printed circuit board and to reliably inspect for the presence of bridges and solder funnels, increase the amount of received light or eliminate the missed detection of reflected light to improve the detection accuracy. Alternatively, it is desirable to be able to receive the sputtered light reflected in all directions in order to perform detection according to the reflection direction of the sputtered light, that is, the reflected light.

[Means for solving problems]

The present invention has been made to solve the above-mentioned problems, and a beam narrowed down so that the reflected light from the inspected printed circuit board becomes substantially specular reflected light is applied to the pattern side of the inspected printed circuit board. Is a mounted printed circuit board automatic inspection device that irradiates the beam vertically to the printed circuit board and detects the regular reflection light of the beam from the printed circuit board to perform soldering inspection of the printed circuit board. Beam sweeping means for sweeping in a state of being vertically irradiated to the substrate, an opening for passing the beam vertically toward the inspected printed circuit board is formed, and the beam irradiation surface of the inspected printed circuit board is covered and irradiated. A light receiving portion having a light receiving surface surrounding the beam, and the beam swept by the light receiving portion in the vertical irradiation state is corrected from the solder surface of the inspected printed circuit board. It receives Shako configured to detect an angle of the solder surface in the sweep process.

[Action]

As shown in FIG. 1 (A), a beam narrowed so that the reflected light from the printed circuit board to be inspected is substantially regular reflected light is vertically irradiated to the pattern side of the printed circuit board to be inspected. . Sputtering light L _{1 with} a low reflection angle by the light receiving unit ₁
The (reflected light) is received by the surrounding light receiving surface S ₁ , and the sputtered light L ₂ having a high reflection angle is received by the ceiling light receiving surface S ₂ . Further, according to the light receiving unit 1 shown in FIG.
The sputtered light L _{1 having} a low reflection angle is received by the light receiving surface S ₂ which is close to the printed circuit board P to be inspected and covers the beam irradiation surface.
The sputtered light L ₂ having a high reflection angle surrounds the beam B and is a light-receiving surface S ₁
Is received by.

The light receiving portion is formed with an opening that allows a beam to be swept in a state where the printed circuit board is vertically irradiated toward the printed circuit board to be inspected, and the beam irradiation surface of the printed circuit board to be inspected is formed. It is configured to have a light receiving surface that covers and surrounds the beam to be irradiated.

With this light receiving unit, it is possible to receive the specularly reflected light of the beam swept in the vertical irradiation state from the solder surface on the printed circuit board to be inspected, and detect the angle of the solder surface in the sweep process from the reflection direction. Therefore, it is possible to recognize the shape of the solder surface from each angle of the solder surface during the beam sweeping process, and it is possible to reliably detect the presence or absence of a bridge or a solder funnel generated on the mounted printed circuit board.

〔Example〕

FIG. 3 is a front view showing the entire mounted printed circuit board automatic inspection apparatus of the embodiment, in which 11 is a casing, and 12 is a printed circuit board P which is an object to be inspected disposed in this casing. X- freely moved in the X-axis and Y-axis directions
This is the Y stage. 1 is as described in detail later,
The light receiving portion is arranged above the XY stage 12 and detects the sputtered light from the printed circuit board P to be inspected. A large number of light receiving elements are arranged on the light receiving surface inside. Reference numeral 13 denotes a light receiver installed below the XY stage 12, which is used for setting the reference point or the like on the printed circuit board.
The laser light passing through is received through a reference hole provided in the printed board. Reference numeral 14 is a group of operation switches provided on the upper surface of the casing 11, 15 is an indicator light showing the operating state of the apparatus, and 16 is a printer for printing out the inspection result.

In this mounted printed circuit board automatic inspection device, inspection data such as the reference position on the inspected printed circuit board, the inspection position or the board name for identifying the type of the printed circuit board is registered in advance in the storage device or the like before the inspection. When inspecting, place the inspected printed circuit board on the XY stage 12 and input the board name etc. from the terminal device (not shown), and it will be automatically inspected based on the inspection data such as the position information of the inspection point recorded in advance. When the inspection is completed, the inspection result such as the location or the number of the detected bridges is printed out from the printer 16, and a mark (not shown) is attached to the vicinity of the bridge location on the printed circuit board to be inspected.

FIG. 4 is a perspective view showing an optical system of the apparatus shown in FIG. 3, 21 is a He-Ne laser gun for emitting a laser beam, and 22 is the He-Ne laser gun for sufficiently narrowing the beam. This is an expander for expanding the laser beam emitted by 21 into a parallel beam with a diameter of about 5 mm. Reference numeral 23 denotes a Y-axis rotating mirror 23a that scans the laser beam so that the beam is swept in the Y-axis direction of the XY stage 12, and X-axis that similarly scans the laser beam so that the beam is swept in the X-axis direction. This is a galvanometer including a rotating mirror 23b, and the galvanometer 23 scans the laser beam within a solid angle based on the movable range of each rotating mirror. A condenser lens 24 condenses the laser beam scanned by the galvanometer 23 on the printed circuit board P via the first mirror 25 and the second mirror 26.

Y by the Y-axis rotating mirror 23a and the X-axis rotating mirror 23b
The distance from each rotating mirror to the printed circuit board P is sufficiently large with respect to the scanning distance in the axial and X-axis directions, and the light is condensed by the condenser lens 24. Therefore, the laser beam is printed as a sufficiently narrow beam for printing. The pattern side of the substrate P is vertically irradiated.

Reference numeral 1 denotes the light receiving portion shown in FIG. 1 (A), and as shown in FIG. 2 in which the light receiving surface S is expanded, a large number of light receiving elements D are arranged on the entire light receiving surface S. The incident sputter light is detected by the large number of light receiving elements D. Further, an opening O is provided in the light receiving surface S ₂ on the ceiling of the light receiving surface S, and a laser beam is vertically irradiated to the printed board through the opening O. Since the irradiation laser beam is sufficiently narrowed through the opening O, the sputtered light detected by the light receiving portion is the printed circuit board P.
It is the specular reflection light portion of the specular reflection light and the diffuse reflection light reflected from.

Further, in this apparatus, a part of the laser beam scanned by the galvanometer 23 is separated by the beam splitter 27, and the beam B transmitted through the beam splitter 27 is irradiated onto the printed board P as described above. , The beam reflected by the beam splitter 27 is condensed by the second condenser lens 28 on the light receiving surface of the light spot position detecting element 29, and the spot position information of the beam detected by this light spot position detecting element 29 is obtained. Based on this, the spot position of the beam B irradiated on the printed circuit board P is servo-controlled.

With the above optical system, the laser beam B with which the printed board P is irradiated is scanned within a rectangular range based on the movable range of the Y-axis rotary mirror 23a and the X-axis rotary mirror 23b of the galvanometer 23, and the beam is swept. Sputtering light reflected in all directions is received by the light receiving section 1 including a sweep range and having a large number of light receiving elements arranged on the inner surface,
Various inspections such as detection of the bridge of the printed circuit board are performed by detecting the intensity of the sputtered light or the presence or absence of the sputtered light.

That is, the pattern direction of the mounted printed circuit board is swept while being vertically irradiated with the beam, and the reflection direction of the specular reflection light of the sputtered light indicated by each output of the plurality of light receiving elements arranged on the light receiving surface S of the light receiving unit 1 is reflected. Therefore, the three-dimensional shape of the irradiation surface can be recognized by detecting the angle of the solder surface in the sweep process.

[Effect of device]

As described above, the present invention irradiates a beam narrowed so that the reflected light from the inspected printed circuit board becomes substantially specularly reflected light vertically to the pattern side of the inspected printed circuit board. An opening is formed to allow the beam to pass through vertically to the printed circuit board to be inspected, and the beam irradiation surface of the printed circuit board to be inspected is covered with a light receiving portion having a light receiving surface surrounding the irradiated beam. Since the specular reflection light from the solder surface of the printed circuit board to be inspected of the beam swept in the vertical irradiation state by the section is received, and the angle of the solder surface in the sweep process is detected from the reflection direction, the beam It is possible to recognize the shape of the solder surface from each angle of the solder surface in the sweeping process of the device, and it is possible to confirm the presence or absence of bridges and solder funnels on the mounted printed circuit board. It can be out.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a light-receiving portion in the mounted printed circuit board automatic inspection apparatus of the present invention, FIG. 2 is a diagram showing the light-receiving surface of the light-receiving portion of the embodiment in a developed manner, and FIG. It is a figure which shows the whole mounted printed circuit board automatic inspection apparatus of an Example, and FIG. 4 is a figure which shows the optical system of the mounted printed circuit board automatic inspection apparatus of an Example. (Explanation of symbols) 1 ... Light receiving part, S ... Light receiving surface, P ... Printed circuit board, B
…… Beam, L …… Sputter (reflected light)

Claims (1)

[Scope of utility model registration request] 1. A pattern side of a printed circuit board to be inspected is vertically irradiated with a beam narrowed so that the reflected light from the printed circuit board to be inspected is substantially specularly reflected light. A mounted printed circuit board automatic inspection device for detecting soldering of a printed circuit board by detecting specularly reflected light of the beam, comprising beam sweeping means for sweeping the beam in a state in which the printed circuit board to be inspected is vertically irradiated. A light receiving portion having an opening for allowing the beam to pass vertically toward the printed circuit board to be inspected, covering a beam irradiation surface of the printed circuit board to be inspected, and having a light receiving surface surrounding the beam to be irradiated. , Receiving the specular reflection light from the solder surface of the printed circuit board to be inspected of the beam swept in the vertical irradiation state by the light receiving unit, and soldering in the sweeping process. Implemented PCB automatic inspection apparatus characterized by the the to detect the angle of.