JPH0575331B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] This invention solves the problem of detecting the accurate pin position due to shadows caused by bending the pin when detecting the pin position by imaging the reflected light from the pin. In order to prevent this from becoming impossible, a beam forming means for forming the laser beam into a slit beam is provided, and the tip of the pin is irradiated with the slit beam.

[Industrial application field]

The present invention relates to a member having a plurality of pins, particularly a pin position detection device for a pin grid array mounted on a printed board.

Printed circuit boards are widely used in the information and communication fields. This printed circuit board is required to have an increasingly higher density in order to improve the performance of the device. On the other hand, components mounted on printed circuit boards are becoming more densely packed, and one example of this is the pin grid array (hereinafter referred to as PGA).

However, some PGA pins are curved and cannot be mounted on a printed circuit board, and there is a need for a pin position detection device that can detect pin positions with high precision.

[Conventional technology]

Conventionally, a device as shown in FIG. 5 has been used to detect the pin position. That is, the PGA 1 is illuminated by the ring-shaped light source 20. On the other hand, the PGA 1 that is irradiated with light has pins 1 and 1 at the center of the metallized patterns 1-11 to 1-1n, respectively.
-1 to 1-n are planted. The ring-shaped light source 20 described above is based on this metallized pattern 1-1.
This is to make the 1 to 1-n parts brighter. Therefore, the light reflected from the PGA 1 is bright in the metallized patterns 1-11 to 1-1n, and is imaged by the TV camera 5.

This imaging state is as shown in FIG. That is, the metallized pattern portion is brightly imaged, and the pin portion is imaged darkly at approximately the center of the metallized pattern portion. This is how the pin position is detected, but if the pin is curved, the metallized pattern in the shadow of the curved pin will become dark, making it impossible to detect the tip position of the pin, and if the metallized pattern If there are scratches on 1-11 to 1-1n, the amount of reflected light will be reduced and the image will be dark, making it difficult to distinguish it from the pin. equipment is used. That is, the PGA 1 is illuminated by the ring-shaped light source 20. On the other hand, being irradiated with light
PGA1 is metallized pattern 1-11 to 1-
Pins 1-1 to 1-n are implanted in the center of 1n, respectively. The ring-shaped light source 20 described above is for brightening the metallized patterns 1-11 to 1-1n. Therefore, the light reflected from PGA1 is reflected from metallized patterns 1-11 to
The 1-1n section is bright and is imaged by the TV camera 5.

This imaging state is as shown in FIG. That is, the metallized pattern portion is brightly imaged, and the pin portion is imaged darkly at approximately the center of the metallized pattern portion. This is how the pin position is detected, but if the pin is curved, the metallized pattern in the shadow of the curved pin will become dark, making it impossible to detect the tip position of the pin, and if the metallized pattern If scratches occur on 1-11 to 1-1n, the amount of reflected light will decrease, resulting in a dark image that will be difficult to distinguish from the pin.

[Problem that the invention seeks to solve]

As described above, conventional devices have a problem in that it is difficult to determine the position of the pin tip due to bent pins or scratches in the metallized pattern, resulting in rough measurements.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pin position detection device that has a simple structure and can detect pin positions with high accuracy.

[Means for solving problems]

In this invention, as shown in FIG. 1, an optical system 4 that irradiates the pins of the PGA 1 operates as a beam forming means that expands the laser beam together with a laser generating element 2 in a horizontal plane perpendicular to the emission direction to form a slit beam. Two cylindrical lenses 3-1, 3
-2. This optical system 4 is a PGA
The tip of pins 1-1 to 1-n is irradiated from both ends of pin 1.

[Effect]

The cylindrical lenses 3-1 and 3-2 irradiate all the pins with an enlarged slit beam and image the tips of the pins brightly, thereby making it possible to detect pin positions with high precision.

〔Example〕

FIG. 1 is a side view of essential parts showing an embodiment of the present invention. Optical systems 4 are provided on both sides of PGA 1. However, each optical system 4 is provided slightly above the horizontal plane of the tips of the pins 1-1 to 1-n so as not to cast shadows on the tips of the pins 1-1 to 1-n.

This optical system 4 includes a laser generating element 2 and a laser beam that is emitted in a required width orthogonal to the emission direction so as to irradiate the entire tip of the pin.
Cylindrical lens 3 that expands to the width of PGA1
-1 and 3-2.

The beam created by this optical system 4 is as shown in FIG. This figure is a view of FIG. 1 from the direction of the TV camera 5. That is, a He--Ne laser is used as the laser generating element 2.
This He-Ne laser beam has a beam diameter of 1 mm and a wavelength of
It is 632.8nm.

Both cylindrical lenses 3-1 and 3-2 have a focal length of f25 mm. When these are arranged at the distance shown in FIG. 2 (5475 mm), a slit-shaped light beam having a width of 30 mm and a thickness of 1 mm is obtained at a distance of 67 mm from the cylindrical lens 3-2.

This slit-shaped light beam irradiates the tips of all the pins, and as described above, irradiates from slightly above the horizontal plane of the tips of the pins so as not to irradiate the metallized pattern.

Note that a filter 6 is provided in front of the TV camera 5 to pass only the wavelength of the laser beam, thereby eliminating the influence of noise from other light sources.

When an image is taken using the above-described embodiment, the pin is bright and clearly detected as shown in FIG. 3, and it is also possible to detect pin bending. Furthermore, if the magnification of the imaging section is increased, the outline of the tip of the pin can also be detected as shown in FIG.

Although the above explanation uses a cylindrical lens as a beam creation means to create a slit beam, it goes without saying that there is no problem with using a rotating polygon mirror to create a slit beam. It goes without saying that types of lenses other than those in the embodiments may also be used. In addition, in the embodiment, the optical system 4 is
It goes without saying that a clearer image can be obtained by using multiple optical systems.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is possible to easily and accurately detect pin positions without being affected by noise, and when applied to the production of printed circuit boards, efficiency and quality can be improved. It is extremely effective in doing so.

[Brief explanation of drawings]

FIG. 1 is a side view of essential parts showing one embodiment of the present invention;
FIG. 2 is a perspective view showing the optical system of the present invention, FIG. 3 is an image taken of the tip of the pin according to the invention, FIG. 4 is an enlarged view of the tip of the pin according to the invention, and FIG. A partial configuration diagram, FIG. 6 is an imaged view of the tip of a pin of a conventional device. In the figure, 1 is a PGA, 2 is a laser emitting element,
3 is a beam creating means, 3-1, 3-2 are cylindrical lenses, 4 is an optical system, 5 is a TV camera, 6
indicates a filter.

Claims (1)

[Scope of Claims] 1. A device that detects the pin position by imaging reflected light from the pins 1-1 to 1-n of a member 1 having a plurality of pins 1-1 to 1-n, comprising: The optical system 4 for irradiating the laser beams 1-1 to 1-n is a laser generating element 2, and the beam forming means 3 receives the laser beam and expands the laser beam in a direction perpendicular to the emission direction of the laser beam to create a slit beam. A pin position detection device comprising: two pairs of optical systems 4 irradiating the tips of the pins 1-1 to 1-n from both side surfaces of the member 1.