JPS63153514A - Light projecting device - Google Patents

Abstract

PURPOSE:To obtain two rectangular beams with a required shape from one incident beam by providing the titled device with an optical system constituted of four lenses and three prisms linearly arranged on the optical axis. CONSTITUTION:A laser beam 11 is converted into a 1st parallel beam 12' by a collimater lens 12 and converted into a beam 14 dispersed only one direction by a 1st concave cylindrical lens 13. The beam 14 is converted into a 2nd parallel beam 15' by a convex cylindrical lens 15, made incident upon a 1st triangular prism 17 so as to be converted into two spectral beams 18 and the interval between two beams is adjusted by a 2nd triangular prism 19. The beams transmitted through the 2nd triangular prism 19 are dispersed only in the longitudinal direction of a rectangular shape by a 2nd concave cylindrical lens 22 and the obtained beams 23 are divided and synthesized by a 3rd triangular prism 24 to form rectangular beams 27. Thus, a required rectangular shape can be obtained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a light irradiation device.

[Summary of the invention]

The present invention provides a light irradiation device that has an optical system composed of four lenses and three prisms, so that two rectangular beams with a desired rectangular shape can be obtained from one incident beam. This is what I did.

[Conventional technology]

Light, such as laser light, is transmitted through a full-notopa nocage IC (
Soldering of electronic components such as FPIC is used as solder melting energy during processing. In many cases, the shape of the processed part of an electronic component to be subjected to such laser processing is rectangular (rectangular), and it is necessary to irradiate the laser beam with a circular fundamental beam in a rectangular shape.

Conventionally, as a means for converting this laser light into two rectangular beams, there is a mask plate 32 having a rectangular opening 33 as shown in FIG. Two rectangular beams 34 are formed on top. In addition, the laser beam that has been made parallel by a collimator lens is first transformed into an elliptical beam by a concave cylindrical lens, then made into a parallel elliptical beam by a convex cylindrical lens, and then converted into two beams by a half mirror and a total reflection mirror. A light irradiation device was proposed in which each beam passes through two triangular prisms to form two rectangular beams. (Patent application No. 61-224559
[Problem to be solved by the invention] In the case of the above mask plate, in order to change the dimensions G, H, and I of the rectangular shape of the beam, it is necessary to change the dimensions of the rectangular opening or to change the mask plate. Although there are methods such as conversion, a complicated mechanism is required to adjust each dimension G, , H, and I of the rectangular shape independently of each other. moreover,
Since a part of the circular basic beam is used to create the rectangular beam, energy loss is large and the energy density of the rectangular beam is non-uniform.

The light irradiation device uses two triangular prisms to form a rectangular beam, and the rectangular beam has good energy efficiency and uniform energy density. It is not possible to adjust the spectral accuracy due to the fact that the two beams are not the same distance from the light source, it is not possible to focus on both beams, and the shape of the rectangular beam is fixed, so it is not versatile. That is a drawback.

[Means for solving problems]

Means for solving the above problems will be explained below using FIG. 1 corresponding to the embodiment.

The present invention is a light irradiation device for forming two rectangular beams, comprising: (a) a collimator lens 12 for obtaining a first parallel beam 12'; (b) the first parallel beam 12'; a first concave cylindrical lens 1 that changes the beam into a beam 14 that is diffused in only one direction;
3. (c), a convex cylindrical lens 15 that converts the diffused beam 14 into a second parallel beam 15'; (d), a first triangular lens that divides the second parallel beam 15' into two separate beams 18; Prism 17, (e) a second triangular prism 1 for adjusting the interval between the two split beams 18;
9. (f), a second concave cylindrical lens 22 that diffuses the beam that has passed through the second triangular prism 19 only in the longitudinal direction of the rectangular shape, and (g), the beam 23 that has passed through the second concave cylindrical lens 22; A third triangular prism 24 that divides and combines to form a rectangular beam 27 is linearly and sequentially arranged on the optical axis, and the convex cylindrical lens 15, the second triangular prism 19, and the third triangular prism 24 are arranged on the optical axis. The present invention relates to a light irradiation device configured to be movable on the top.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the light irradiation device of this embodiment linearly sequentially, on the optical axis of a laser beam 11 emitted from an optical fiber 10 connected to a laser oscillator (not shown), First concave cylindrical lens 13, convex cylindrical lens 15, first triangular prism 17, second triangular prism 19, second concave cylindrical lens 22
It consists of an optical system in which a third triangular prism 24 is arranged.

Convex Cylindrical Lens 15 is arranged in such a direction that the direction in which light changes is the same as that of the first concave cylindrical lens 13. The first triangular prism 17 has an edge on the upper side and is arranged at a position where it becomes the beam center, and the second triangular prism 19 has an edge on the lower side and is arranged at a position where the edge is on the lower side and the first triangular prism 17
It is placed parallel to the edge of The second concave cylindrical lens 22 is arranged at an angle where the direction of light change is perpendicular to that of the convex cylindrical lens 15.

The third triangular prism 24 is arranged so that its edge is on the lower side and parallel to the generatrix of the second concave cylindrical lens 22 .

The convex cylindrical lens 15, the second triangular prism 19, and the third triangular prism 24 are arranged parallel to the optical axis with arrows 1, respectively.
Movement is possible along 6.20.25.

According to the light irradiation device of this embodiment, two rectangular beams 27 are formed in the following manner.

The laser beam 11 emitted from the optical fiber 10 is generally circular and has a Gaussian energy density distribution. The beam 11 is turned into a parallel circular beam 12' by the collimator lens 12, and further turned into an elliptical beam 14 which is spread in only one direction perpendicular to the output axis by the first concave cylindrical lens 13. This beam 14 is turned into a parallel elliptical beam 15' by a convex cylindrical lens 15, and is incident on a first triangular prism 17. This prism 1
7 is located at a position where its central edge passes through the center of the parallel elliptical beam, and the beam transmitted through this prism 17 is split into two rectangular beams to form a two-split beam 18. The beam 18 then passes through a second triangular prism 19 which corrects the two beams 18 angled by the prism 17 to opposite angles. The beam 21 transmitted through the prism 19 becomes a beam 23 which is diffused only in the direction corresponding to the longitudinal direction of the rectangular shape by the second concave cylindrical lens 22, and then enters the third triangular prism 1.24. Since this prism 24 is arranged so that its edge passes through the center of the beam 23, when the beam 23 passes through this prism 24, a split composite beam 26 is formed, and this beam 26 is transmitted while changing its composition ratio. A rectangular beam 27 is defined as a point moving away from the prism 24 and having equal energy density along the longitudinal direction.

The convex cylindrical lens 15 adjusts the focus of the rectangular beam 27, and by moving along the arrow 16, adjusts the rectangular beam 27 to a medium size. The second triangular prism 19 adjusts the spacing between the rectangular beams 27 by moving along the arrow 2o. The second triangular prism 24 adjusts the longitudinal dimension J of the rectangular beam 27 by moving along the arrow 25.

Next, a short-side rectangular beam 3 and a long-side rectangular beam 4 necessary for soldering the FPICI to the substrate 5 shown in FIG. 2 via its IC leads 2 are formed using the light irradiation device of this embodiment. An example will be explained with reference to FIGS. 3 to 6.

Adjustment of rectangular beam spacing: Each spacing F of rectangular beams 3.3 and 4.4 in Fig. 2
and C are adjusted by moving the second triangular prism 19 in FIG. The beams 18 split by the first triangular prism 17 travel in directions that intersect with each other, and the beams 18 are split by the first triangular prism 17.
incident on . The prism 19 bends the beam 18 in the opposite direction by an angle smaller than or equal to the angle bent by the first triangular prism 17, and emits it as a beam 21. The spacing between the beams 21 is changed by changing the position of the prism 19,
Finally, the spacing between the rectangular beams also changes. That is, by moving the prism 19 in FIG. 3 to the position of the prism 19 in FIG. 5 by a distance M, the beam spacing is changed from C to F.
can be changed to

Adjustment in the length direction of the rectangular beam: To adjust the lengths D and A of the rectangular beam 3.4 in FIG. 2, the third triangular prism 24 in FIG. direction). The prism 24 diffuses the beam 23 with the second concave cylindrical lens 22.
The width of the combined beam 26 is changed depending on the light receiving position.

In order to change the rectangular beam length from D in FIG. 5 to A in FIG. 6, the prism 24 in FIG.
Move by N to position 24.

Adjustment in the width direction of the rectangular beam: The widths E and B of the rectangular beam 3.4 in FIG. 2 are the convex cylindrical lens 15 and the first concave cylindrical lens 1.
3, the imaging position changes and the spread angle of the beam 26 in the width direction also changes, so the width of the beam 26 changes at an arbitrary position.

Adjustment of energy density: In FIGS. 5 and 6, the beam 26 split and combined from the center by the third triangular prism 24 is
It progresses while changing the synthesis rate depending on the distance from. The energy density required for processing is the length D of the rectangular beam
and A, and if a Gaussian-distributed beam is used as the beam 11, a rectangular beam with uniform energy density can be obtained at a position where the combining rate is almost at its maximum. P in FIG. 5 and 0 in FIG. 6 represent points of uniform energy density in rectangular beams of different sizes, each of which is obtained by adjusting the distance from the entire optical system.

〔Effect of the invention〕

As described above, the light irradiation device of the present invention provides the following effects: (1) Two rectangular beams can be obtained from one incident beam, and the beam spacing and rectangular shape of these rectangular beams can be changed. This made it possible to make it more general-purpose. (2) Since the two rectangular beams have the same optical conditions, the accuracy is high, and the spectral accuracy can be adjusted by adjusting the position of the first triangular prism 17. (3) Since the energy density in the longitudinal direction of the rectangular beam is divided into two parts and combined by the third triangular prism 24, it becomes uniform and the combination rate can be adjusted. (4) When converting into a rectangular beam, all incident beams are taken into the lens system and processed only through transmission, resulting in high energy efficiency. (5) Cost is low because no complicated shaped lenses or prisms are used. (6) The lens system has a linear arrangement, high accuracy, and high reliability.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the light irradiation device of the present invention;
Figure 2 is a perspective view showing the FPIC and the board, Figures 3 and 4.
Each figure is a side view of the optical system of the embodiment, FIGS. 5 and 6 are front views of the optical system of the embodiment, and FIG. 7 is a perspective view of the conventional example. In addition, in the symbols used in the drawings, 11------------ Laser beam 12--
---1--Collimator lens 13-----1--
------First concave cylindrical lens 15-----
---------6 cylindrical lens 17----
----First triangular prism 19-----------Second triangular prism 22--Second concave cylindrical lens 24-- Three triangular prisms 27-=----- rectangular beams.

Claims (1)

[Scope of Claims] A light irradiation device for forming two rectangular beams, comprising: (a) a collimator lens for obtaining a first parallel beam; (b) a collimator lens for forming the first parallel beam in one direction; (c) a convex cylindrical lens that converts the diffused beam into a second parallel beam; (d) splits the second parallel beam into two separate beams; a first triangular prism; (e) a second triangular prism for adjusting the interval between the two divided beams; (f) a second concave cylindrical prism for diffusing the beam transmitted through the second triangular prism only in the longitudinal direction of the rectangular shape. and (g) a third triangular prism that splits and combines the beams transmitted through the second concave cylindrical lens to form a rectangular beam, which are linearly and sequentially arranged on the optical axis, and the convex cylindrical lens, the third triangular prism, and A light irradiation device configured such that two triangular prisms and the third triangular prism are movable on an optical axis.