JP2520935B2 - Optical device for image input of mark for alignment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] A work process in which parts to be assembled with each other are separated into an upper part and a lower part, respective alignment marks of these parts are read and relative positions are confirmed, and then automatically assembled. The optical device for inputting the image of the mark in 1), the object is to propose an optical device in which only one camera is arranged at a predetermined position and the marks at a plurality of positions are read by the one fixed camera. A first total reflection mirror that totally reflects the reflected light from the mark attached to the mark and a second total reflection mirror that totally reflects the reflected light from the mark attached to the component on the other side. The third total reflection mirror, which is arranged so that the light reflected by the second total reflection mirror has an optical path parallel to each other and totally reflects one reflected light of the reflected light having the parallel optical path, and the other reflection Light The half mirror for reflecting is arranged so that the reflected light from the third total reflection mirror passes through the half mirror and the optical paths coincide with each other, and the reflected light from the third total reflection mirror and the half mirror is projected. One common camera is arranged at the designated position.

[Industrial applications]

The present invention relates to an optical device for inputting an image of a mark in a work process in which parts to be assembled with each other are separated into an upper part and a lower part, and respective alignment marks of these parts are read to confirm their relative positions and then automatically assembled. Regarding For example, an integrated circuit mounted on a printed circuit board requires a large amount of heat to be cooled. Various cooling mechanisms have been proposed for this purpose, but recently liquid cooling, which has a large cooling capacity, has been generally used. The cooling structure is shown in FIG.

As shown in FIG. 4, integrated circuits 41 are mounted in a matrix on the printed board 40, and a cooling block 60 for cooling the integrated circuit 41 is provided on the printed circuit board via the flange 50.
Mounted on 40. The cooling block 60 is formed with a flow path 61 through which the refrigerant 64 passes, and the integrated circuit 41 is formed in the flow path 61.
An opening 61a is formed in a portion facing to the opening 6a.
A bellows 62 having a heat transfer plate 63 attached to its tip is fixed to 1a. According to this configuration, the heat generated in the integrated circuit 41 is transferred to the refrigerant through the heat transfer plate 63, so that the integrated circuit
41 cooling is performed.

[Conventional technology]

Here, when mounting the flange 50 on the printed board 40,
This is performed as shown in FIG.

That is, the printed board 40 and the flange 50 are connected to the jigs 70 and 71, respectively.
Between the marks 42 formed on the contact surface 51 between the mark 42 formed on the surface of the printed board 40 opposite to the integrated circuit mounting surface of the printed board 40 and the cooling block 60 of the flange 50.
After the positioning is performed so that the distance becomes constant, the printed circuit board is inserted into the concave portion of the flange 50 and fixed. Positioning of the printed board 40 and the flange 50 is performed by one camera 80.
One of the marks 52 is read by and displayed on the display device 90. Thereafter, the camera 80 is moved to read the other mark 42 and display it on the display device 90. By making the display positions of both marks correspond to the movement amount from the reference position of the camera, the distance between both marks can be known on the display surface. If this interval deviates from the set value, the printed board is moved to match the set value.

[Problems to be Solved by the Invention]

However, in such a conventional method, the work efficiency is poor for the time required for the movement, and there is a problem in the accuracy of the camera position due to the movement.

Therefore, an object of the present invention is to provide an optical device in which only one camera is arranged at a predetermined position and marks at a plurality of positions are read by the one fixed camera.

[Means for solving the problem]

FIG. 1 shows the principle of the present invention. The light 10 reflected from the mark A at one position is reflected in a predetermined direction by the total reflection mirror 14, and the light 12 reflected from the mark B at the other position.
Is reflected by the total reflection mirror 16 in parallel with the optical path of the light 10. These parallel light paths 10 and 12 are total reflection mirrors, respectively.
The light is reflected in the same optical path direction by the 18 and the half mirror 20. A camera 22 is provided in front of this optical path direction.

[Work]

If the mirrors are arranged as described above, one mark and the other mark can be read by one camera fixed at a predetermined position. In this case, when the reflected lights 10 and 12 from the marks A and B have the same intensity, the light 10 projected to the camera 22 is half the intensity because it passes through the half mirror 20, and the light 12 is finally the half mirror 20. Since it passes through, the light intensity becomes half, and eventually the light 10 or 12 having the same light intensity is projected on the camera 22. Therefore, the camera 22 need not be changed once it has been set to a predetermined sensitivity.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the accompanying drawings. FIG. 2 is a schematic view of the optical device in which the upper part is provided with two alignment marks A and C, and the lower part is also provided with two alignment marks B and D. . The reflected light 10, 12, 24, 26 reflected from each of these marks A, B, C, D corresponds to the corresponding shutter S1, S
It can be blocked by 2, S3, S4. The image of each mark is taken by one camera 22, but here it is considered that one image is taken for each mark. That is, the four shutters S1, S2,
Only one of S3 and S4 can be opened, the camera 22 can be used for copying, and the other shutters can be opened one after another for copying. Here, the light reflected from each mark 10,12,
The optical paths and light intensities of 24 and 26 will be described.

The reflected light 10 of the upper mark A is totally reflected by the total reflection mirror 14 and projected onto the half mirror 20. The reflected light 12 of the lower mark B is totally reflected by another total reflection mirror 16 forming a pair with the above total reflection mirror 14 so as to form an optical path parallel to the reflected light 10 and projected onto another total reflection mirror 18. . The total reflection mirror 18 and the half mirror 20 described above have an optical path of the light 12 totally reflected by the total reflection mirror 18 and a reflection optical path of which half the light 10 is transmitted through the half mirror 20 and the rest is reflected. So that they are parallel to each other. Total reflection mirror 18
Since the light 12 totally reflected at must pass through the half mirror 20, the light intensity is half that of the light 10. If the intensity of light reflected from A and B is 1.0,
It becomes 0.5 each when reflected or transmitted through the half mirror 20. In the present embodiment, one half mirror 38 is provided between the upper camera 22 and the other marks C and D because it is necessary to read the marks C and D.
The intensities of 0 and 12 are both 0.25, and the light enters the camera 22 with this light intensity.

Reflected light from the other upper mark C and lower mark D 24
And 26 are reflected by a pair of total reflection mirrors 28 and 30 in a direction parallel to the reflected light 10 and 12, and the light 24 is reflected by the half mirror 3
The light intensity is reduced to half by 4 and is reflected upwards.
Is reflected upward by the total reflection mirror 32 and further passes through the half mirror 34. The total reflection mirror 32 and the half mirror 34 are arranged parallel to each other so that the optical paths of the two lights 24 and 26 become the same optical path after being reflected by or passed through the half mirror 34. Light reflected from marks C and D respectively 24,26
If the light intensity of is 1.0, which is the same as for marks A and B,
The light intensities 26 are 0.5 at the time of reflection or passage through the half mirror 34, respectively. After that, the lights 24 and 26 are both reflected by the total reflection mirror 36 and enter the camera 22 via the half mirror 38 described above. The total reflection mirror 36 is disposed so that the optical paths of the lights 24 and 26 after being reflected by the half mirror 38 match the optical paths of the lights 10 and 12 described above. The wide intensities of the lights 24 and 26 entering the camera 22 are 0.25 because they are transmitted through the two half mirrors 34 and 38.
And has the same light intensity as the light 10 and 12. That is, each mark
If the light intensities of the reflected lights of A, B, C, and D are about the same, it is not necessary to change the initially set sensitivity until the operation of inputting the images of all the marks into the camera 22 is completed.

FIG. 3 is a schematic plan view of the optical system device of FIG. 2 seen from above.
Shown in the figure. Reflected light from each mark A, B, C, D 10, 12, 24, 26
If the optical path lengths are set to the same length, each mark is projected on the camera 22 at the same magnification. Here, a plan view layout relationship of the respective mirrors for making the optical paths of the reflected lights 10 and 24 of the marks A and C the same and the optical paths of the reflected lights 12 and 26 of the marks B and D the same is shown. explain. If the optical path length from the total reflection mirror 18 to the half mirror 20 in the optical path of the reflected light 12 of the mark B is sufficiently shorter than the total optical path length, the mark B
Is projected at the same magnification as marks A and C. From the beginning, either change the working distance by the difference between the upper and lower optical paths, or
4 image input sections (total reflection mirror: front of 14, 16, 28, 30)
If the objective lens of 2 is used as a relay lens composed of two lenses and the focal lengths are adjusted (in this case, the upper and lower sides can be made the same without changing the working distance), the images of all the marks are at the same magnification, and It can be projected as a clear image on the imaging surface of the camera. The same applies to the mark D. Let the point PS be the vertex of an isosceles right triangle whose base is the line segment connecting the points PAB and PCD in FIG. That is, point PS and point PCD
The length XO of the side connecting points and the length YO of the side connecting points PS and PAB
And have the same length. The other two vertices PT and PU of a rectangle having two vertices at the point PS and the point PAB are mirrors 18, 20, 38 and a camera 22,
Alternatively, the mirrors 32, 34, 36 are arranged. By disposing the optical system device in this way, the optical path length of the light 10 and the optical path length of the light 24 become the same, and the optical path length of the light 12 becomes the same as the optical path length of the light 26.

If the setting is changed or other reasons, for example, point PCD
Is located at the point PCD ′ indicated by the chain double-dashed line, the point PT
Can be moved to a point PT 'indicated by a chain double-dashed line, and another optical mirror can be added to the original point PT to set the optical path length to the same length. In this case, the line segment length between the points PT and PT 'is set to one half of the line segment length between the points PCD and PCD'.

The above embodiment is described for the case where there are four marks. However, for example, the case where there are no marks C and D but only the marks A and B is naturally applied.
The same applies to only D and D. Further, the marks A and C may be attached to one upper part and the marks B and D may be attached to one lower part, or each mark may be attached to a separate part.

Next, the step of positioning the printed board 40, the flange 50 and the I / O pin shown in FIG. 4 by using the optical device of the present invention will be described. Fig. 6 shows printed board 40 and flange 50
To position the printed board 40 on the lower base block 100 and the flange 50 on the upper holding plate 101,
Attach to. Then, the optical device according to the present invention is arranged between the both. Although two optical devices are shown in the figure, only one optical device is actually used, and when positioning on one side is completed, the optical device is moved to the reflecting side to perform positioning. For the positioning, the image C of the mark 52 is guided to the reflecting mirror 28, the mark 42 is guided to the reflecting mirror 16 as the image B, and the mark 22 is guided to the camera 22 through the above-mentioned path to know the distance between both marks. Will be performed. After the printed board and the flange are positioned in this manner, they are integrated.

Next, I / O pins are attached to the printed board by reflow soldering, and the positioning for this is performed as shown in FIG. I / O pins are inserted into a base plate 102 in which blind holes (not shown) are formed in a substantially matrix shape, and the printed board 40 integrated with the flange 50 by the base block 100 and the holding plate 101 is arranged to face. And the sixth between
As in the case of the figure, the optical device 110 is installed and the mark 103 on the base plate 102 is taken as the image B, and the mark 44 on the printed board 40 is taken as the image A into the camera 22. Although not particularly shown, alignment of the flange and the cooling module is similarly performed.

〔The invention's effect〕

According to the present invention, a plurality of marks can be read by a single camera provided at a predetermined position, and the relative positions between the marks can be measured quickly and highly accurately.

[Brief description of drawings]

1 is a principle view of an optical device according to the present invention, FIG. 2 is a perspective view of an embodiment of the present invention, FIG. 3 is a schematic plan view of FIG. 2, and FIG. Fig. 5, Fig. 5 is a diagram showing a conventional alignment method, Fig. 6 is a diagram showing a positioning process of a printed board and a flange, and Fig. 7 is a diagram showing a positioning process of an I / O pin and a printed board. 14,16,18,28,30,32,36 …… Total reflection mirror, 20,34,38 …… Half mirror, 22 …… Camera, A, B, C, D …… Mark, S1, S2, S3 , S4 …… Shutter.

Claims (1)

(57) [Claims] 1. A first total reflection mirror (14; 28) for totally reflecting reflected light (10; 24) from a mark (A, C) attached to a component on one side, and a component on the other side. Mark attached to (B; D)
And a second total reflection mirror (16; 30) for totally reflecting the reflected light (12; 26) from the above so that the light reflected by the first and second total reflection mirrors becomes an optical path parallel to each other. Then, a third total reflection mirror (18; 32) that totally reflects one reflected light of the reflected light that forms the parallel optical path and a half mirror (20; 34) that partially reflects the other reflected light. Arranged so that the reflected light from the third total reflection mirror passes through the half mirror and the optical paths coincide with each other, and is common to the positions where the reflected light from the third total reflection mirror and the half mirror are projected. 1. An optical device for inputting an image of a positioning mark, characterized in that one camera (22) is provided.