JPH08132267A - Laser beam scanner - Google Patents

Abstract

PURPOSE: To make an irradiating angle freely adjustable with a simple structure by converting a laser beam into plural linear scanning laser beams with a polarizing prism, its rotary means and plural semicylindrical lenses. CONSTITUTION: A laser spot light for circular-arc scanning is made incident on the upper surface of two hemicylindrical lenses 11a, 11b for branched and linear scan conversion, and refracted with the circular arc scanning part converted to a linear scanning because of the hemicylindrical shaped lower face. The linear scanning laser beam outputted from the hemicylindrical lenses 11a, 11b for branched and linear scan conversion is transmitted through hemicylindrical lenses 13a, 13b for adjusting the irradiating angle of a laser beam, and a circuit substrate 25 is irradiated with it. In this case, the hemicylindrical lenses 13a, 13b are rotated by pulse motors 14a, 14b for adjusting an irradiating angle, changing the irradiating direction of the laser beam, namely, the angle of the laser beam incident on the circuit substrate 25, and thus, the irradiating angle θ is changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser light scanning device used in a laser light processing device such as a laser soldering device.

[0002]

2. Description of the Related Art Conventionally, when an electronic component such as a semiconductor is soldered to a circuit board, a laser beam is scanned along a soldering line and the laser beam melts the solder to melt the electronic component and the circuit. Means for joining with a substrate are known.

In order to scan the laser light along the soldering line, a laser light scanning device has been conventionally used. A conventional laser light scanning device will be described with reference to FIG. 4. Reference numeral 20 is a laser light oscillator.
The laser light oscillated by the laser light oscillator 20 is branched by a branching device 21 provided on the side portion, and these branched laser lights are collected at predetermined positions by optical fibers 22a and 22b, respectively. It is transmitted to the optical lenses 23a and 23b. In the condenser lenses 23a and 23b, the laser light sent by the optical fibers 22a and 22b is converted into spot light, sent to the reflection mirror 24, and reflected by the reflection mirror 24, whereby the circuit board is obtained. It is focused on the lead wire 27 portion of the electronic component 26 placed on 25.

The distance between the pair of condenser lenses 23a and 23b is adjusted by the pitch changing pulse motor 28 and the belt 29, whereby the distance between spot lights, that is, the pitch p can be changed. .

Further, the reflection mirror 24 is swung by a scanner motor 30 connected on an axis, whereby the laser spot light on the circuit board 25 is indicated by an arrow A. It is designed to scan in a linear direction.

[0006]

However, in the conventional laser optical scanning device as described above, the circuit board 2 is used.
The scanner mirror 30 is designed to oscillate the reflection mirror 24 in order to perform laser scanning on the scanner 5. However, a dedicated controller is required to control the operation of the scanner motor 30. Yes, the cost is high.

Further, in order to obtain two parallel laser beams, the laser beam oscillated by the laser optical oscillator 20 is branched by the branching device 21, and a special branching device 21 is required. Therefore, the cost is also high in this respect.

Further, although the irradiation angle of the laser light applied to the circuit board 25 slightly changes due to the swing of the reflection mirror 24, the laser light enters the circuit board 25 almost at a right angle, and this irradiation angle. Since it is not possible to freely adjust the temperature, there is an inconvenience that it is not possible to obtain an appropriate irradiation condition according to the shape of the electronic component. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a laser light scanning device having a simple structure and capable of freely adjusting the irradiation angle.

[0009]

In order to achieve the above object, the invention of claim 1 is a laser oscillating means for oscillating laser light, and a transfer means for transferring the oscillated laser light. When,
A condenser lens connected to the transfer means for collecting the transferred laser light into a spot light, a deflection prism for deflecting the optical path of the spot light, and a laser for deflecting the deflection prism by rotating the deflection prism. Rotating means for scanning the spot light in an arc shape, and a plurality of halves provided on the arc of the laser spot light to be arc-scanned and for branching the laser spot light to be arc-scanned and converting it into linear scanning. A cylindrical lens,
Means for adjusting the relative distance between the deflecting prism and the semi-cylindrical lens to change the linear length of the laser spot light linearly scanned, and a means for adjusting the linear length of the laser spot light linearly scanned. A plurality of other semi-cylindrical lenses capable of changing a rotation angle for adjusting an irradiation angle and pitch changing means for changing a pitch of a plurality of laser spot lights linearly scanned are provided. To do.

The invention according to claim 2 is characterized in that the rotating means for rotating the deflecting prism to scan the deflected laser spot light in an arc shape is a pulse motor. According to a third aspect of the present invention, the plurality of semi-cylindrical lenses whose rotation angles can be adjusted to adjust the irradiation angles of the plurality of laser spot lights that are linearly scanned are rotated by a pulse motor. And

The invention of claim 4 is characterized in that the pitch varying means is a belt to which a plurality of semi-cylindrical lenses are connected, and a pulse motor for driving and driving the belt. A fifth aspect of the invention is characterized in that the laser light scanning device according to any one of the first to third aspects is used as a laser light irradiation means of a laser soldering device.

[0012]

According to the invention of claim 1, the laser light oscillated from the laser oscillating means is converted into a spot light by the condenser lens, and this spot light is incident on the deflecting prism and this deflecting prism. The laser spot light scanned in an arc is rotated by the rotation of the laser beam, and the laser spot light scanned in the arc is branched by a plurality of semi-cylindrical lenses and converted into a linear scan. The irradiation angle is adjusted by each of the plurality of semi-cylindrical lenses, and the pitch is adjusted by the pitch changing means. Therefore, the linear scanning length, the irradiation angle, and the pitch can be freely changed, and the scanning can be performed according to the shape of the scanning line.

According to the invention of any one of claims 2 to 4, the laser light scanning device of claim 1 can be realized with a simple structure. According to the invention of claim 5, the advantage of the invention of any one of claims 1 to 4 can be effectively utilized for the laser soldering apparatus.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in FIGS. In the figure, reference numeral 1 is a laser oscillator that oscillates laser light.
The laser light oscillated in 1 is guided to a predetermined position by one optical fiber 2 as a transfer means.

At the tip of the optical fiber 2, that is, at a predetermined position, a condenser lens 3 for condensing the transferred laser light into spot light is connected. The condenser lens 3 is supported by a holder 4, and this holder 4 has a condenser lens 3
A deflecting prism 5 for introducing the spot light condensed by the condensing lens 3 is rotatably attached so as to face downward. The deflection prism 5 is composed of, for example, a wedge prism, and deflects the incident spot light and outputs it.

The deflecting prism 5 is rotated by the rotating pulse motor 6 attached to the holder 4 via the gears 7a and 7b, and the deflecting prism 5 is deflected by the rotation. The laser spot light output as a result can be conically rotated. Therefore, the tip of the laser spot light is scanned in an arc shape.

A ball screw 8 is screwed into the holder 4, and the ball screw 8 is connected to a lifting pulse motor 9. The lifting pulse motor 9 is attached to the base 10. When the lifting pulse motor 9 is rotationally driven, the holder 4 is moved up and down via the ball screw 8.
Therefore, the deflection prism 5 is moved up and down.

Below the deflecting prism 5, a plurality of, for example, two branch and linear scanning conversions are located on the arc of the laser spot light which is scanned in an arc as the deflecting prism 5 rotates. Semi-cylindrical lenses 11a and 11b are provided. These semi-cylindrical lenses 11a and 11b are mounted on the base 10 with their flat surfaces facing upward, which is not shown in detail, and the upper surfaces of these lenses are circularly scanned by the deflection prism 5 to generate laser spot light. Comes in. The laser spot light incident on the upper surfaces of these semi-cylindrical lenses 11a and 11b is refracted in these semi-cylindrical lenses 11a and 11b, and the lower surface has a semi-cylindrical shape. Convert to. Since each of the semi-cylindrical lenses 11a and 11b converts into linear scanning according to the arc length incident on the upper surface of itself, the two semi-cylindrical lenses 1
When 1a and 11b are used, a single arc-scanned ray
The spot light is generated by these semi-cylindrical lenses 11a and 11b.
Thus, two linear scanning laser spot lights are output.

That is, the two semi-cylindrical lenses 11a,
As shown in FIG. 2, 11b is for branching one arc-scanning laser spot light into two linear-scanning laser spot lights.

The linear scanning range of the laser spot light converted into the linear scanning, that is, the scanning length l, is an arc scanning laser which is incident on the upper surfaces of the semi-cylindrical lenses 11a and 11b.
It changes depending on the arc length of the spot light.

The arc lengths are semi-cylindrical lenses 11a, 1
The diameter D of the circular scanning laser spot light on the upper surface of 1b changes depending on the diameter D of the cone, that is, the deflecting prism 5
And the semi-cylindrical lenses 11a and 11b. Therefore, in order to adjust the linear scanning length 1 of the laser spot light, the deflection prism 5 is moved up and down by the rotational driving of the up / down pulse motor 9.

Below the semi-cylindrical lenses 11a and 11b for branching and linear scanning conversion, a pair of support bases 12 are provided.
a, 12b are provided, and these support bases 12a, 1
2b is a semi-cylindrical lens 13 for adjusting the laser light irradiation angle, which faces the semi-cylindrical lenses 11a and 11b.
a and 13b are rotatably attached.

The semi-cylindrical lenses 13a, 13b for adjusting the laser light irradiation angle adjust the linearly scanned laser light output from the semi-cylindrical lenses 11a, 11b for branching and linear scanning conversion. It receives from the flat upper surface and outputs from the lower surface that forms a cylindrical surface. The shaft portion has a pulse motor 14 for adjusting the irradiation angle.
It is connected to a and 14b. When these irradiation angle adjusting pulse motors 14a and 14b are operated, the semi-cylindrical lens 1
3a and 13b are rotated, so that the angle of the emitted laser light, in other words, the angle of the laser light incident on the circuit board 25 can be changed.

The distance between the supports 12a and 12b can be changed by the pitch varying pulse motor 15 and the belt 16 so that the two laser spot lights incident on the circuit board 25 can be changed. , The pitch is adjusted. Reference numeral 26 is an electronic component, and 27 is a lead wire.

The operation of the embodiment having such a configuration will be described. The laser light oscillated by the laser oscillator 1 is guided to the condenser lens 3 by the optical fiber 2 and output from the condenser lens 3 as spot light.

The spot light oscillated from the condenser lens 3 enters the deflection prism 5 and is deflected and output from the deflection prism 5. In this case, the deflecting prism 5 is rotated by the rotation driving pulse motor 6, so that the laser spot light deflected and output from the deflecting prism 5 is conically rotated, and the tip end thereof is arcuate. To be scanned.

The laser spot light which is circularly scanned is
Two semi-cylindrical lenses 11a for branching and linear scanning conversion,
Light enters the upper surface of 11b. These semi-cylindrical lenses 11
The laser spot light incident on the upper surfaces of a and 11b is refracted in these semi-cylindrical lenses 11a and 11b, and since the lower surface has a semi-cylindrical shape, the arc scanning is converted into linear scanning. Moreover, each semi-cylindrical lens 11a, 1
1b converts into a linear scan according to the length of an arc incident on the upper surface of itself, so that the two semi-cylindrical lenses 11a and 11b
Will output the above-mentioned one circularly scanned laser spot light by converting it into two linearly scanned laser spot lights each time it passes through these semi-cylindrical lenses 11a and 11b. . That is, the two semi-cylindrical lenses 11
As shown in FIG. 2, a and 11b split one circular scanning laser spot light into two linear scanning laser spot lights.

In this case, the linear scanning length 1 of the laser spot light converted into the linear scanning is the semi-cylindrical lens 11 concerned.
It changes depending on the diameter D of the circular scanning laser spot light entering the upper surfaces of a and 11b, and this diameter D changes depending on the cone height, that is, the distance L between the deflection prism 5 and the semi-cylindrical lenses 11a and 11b. .

Therefore, when the raising / lowering pulse motor 9 is operated to move the holder 4 up and down through the ball screw 8 and the deflection prism 5 is moved up and down, the deflection prism 5 and the semi-cylindrical lens 11a, The distance L from 11b changes and the diameter D of the circular-arc laser spot light changes, so that the linear scanning length l of the laser spot light can be adjusted.

In this way, the linearly scanned laser light output from the semi-cylindrical lenses 11a and 11b for branching and linear scanning conversion is used for adjusting the laser light irradiation angle provided below them. The circuit board 25 is irradiated with light through the semi-cylindrical lenses 13a and 13b. In this case, when the semi-cylindrical lenses 13a and 13b for adjusting the laser light irradiation angle are rotated by the irradiation angle adjusting pulse motors 14a and 14b,
The output direction of the laser light that has passed through these semi-cylindrical lenses 13a and 13b, that is, the angle of the laser light that enters the circuit board 25 changes, and therefore the irradiation angle θ shown in FIG. 3 can be changed. .

When the pitch changing pulse motor 15 is operated, the semi-cylindrical lens 1 for adjusting the laser light irradiation angle is provided.
The distance between 3a and 13b is changed, so that the distance between the two laser spot lights incident on the circuit board 25, that is, the pitch p is adjusted.

As described above, according to the laser light scanning device of the above-described embodiment, the linear scanning length l of the laser spot light, the irradiation angle θ and the pitch p can be freely selected. Even if the shape of the electronic component 26 to be changed is changed, the shape can be dealt with.

Moreover, the laser light guided by one optical fiber 2 is converted into two by the deflecting prism 5, its rotating pulse motor 6 and a pair of semi-cylindrical lenses 11a and 11b.
Since the light is converted into the linear scanning laser light of the book, the conventional branching device is not necessary, an expensive controller is not necessary, and the above-mentioned configuration is cheaper than these branching devices and controllers. .

The present invention is not limited to the above embodiment. That is, in the above-described embodiment, the two semi-cylindrical lenses 11a and 11b for branching and linear scanning conversion are provided on the circular arc of the laser spot light which is circularly scanned as the deflection prism 5 rotates. However, if three semi-cylindrical lenses are arranged on the arc of the laser spot light that is scanned in an arc, the number of laser beams that are branched will be three, and thus a plurality of semi-cylindrical lenses will be formed. A shaped lens may be provided.
In addition, each driving device has pulse motors 6, 9, 14a, 14
It is not limited to b and 15.

[0035]

As described above, according to the invention of claim 1, the linear scanning length, the irradiation angle, and the pitch of the laser beam can be freely changed, and the scanning can be performed according to the shape of the scanning line. Become. Moreover, since the laser light guided by the transfer means such as an optical fiber is converted into a plurality of linear scanning laser light by the deflecting prism, its rotating means and a plurality of semi-cylindrical lenses, it is possible to change the laser light to the conventional one. There is an advantage that a branching device with a special controller is not necessary and the cost is relatively low.

According to the invention described in any one of claims 2 to 4, the laser light scanning device of claim 1 can be realized with a simple structure. Further, according to the invention of claim 5, the advantages of the invention according to any one of claims 1 to 4 can be effectively utilized for the laser soldering apparatus.

[Brief description of drawings]

FIG. 1 is a block diagram showing an entire laser light scanning device according to an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of a main part of the embodiment.

FIG. 3 is a view for explaining an irradiation angle of laser light of the same embodiment.

FIG. 4 is a configuration diagram showing an entire conventional laser optical scanning device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Laser oscillator 2 ... Optical fiber 3 ... Condensing lens 5 ... Deflection prism 6 ... Rotating pulse motor 8 ... Ball screw 9 ... Lifting pulse motor 11a, 11b ... Half for branching and linear scanning conversion Cylindrical lens 13a, 13b ... Semi-cylindrical lens 14a, 14b ... Laser light irradiation angle adjusting pulse motor 15 ... Pitch changing pulse motor 25 ... Circuit board 26 ... Electronic component

Claims (5)

[Claims] 1. A laser oscillating means for oscillating laser light, a transfer means for transferring the oscillated laser light, and a spot of the transferred laser light connected to the transfer means. A condenser lens for condensing light, a deflecting prism for deflecting the optical path of the spot light, a rotating means for rotating the deflecting prism to scan the deflected laser spot light in an arc shape, and the arc scanning. A plurality of semi-cylindrical lenses provided on the circular arc of the laser spot light for branching the circularly scanned laser spot light to convert it into linear scanning; Means for adjusting the relative distance between the laser spot light and the linear length of the laser spot light linearly scanned, and a rotation angle change for adjusting the irradiation angle of each of the plurality of laser spot light linearly scanned. Other multiple halves possible A columnar lens, multiple records by these linear scan - The record to the pitch varying means for varying the pitch of the spot light, characterized by comprising a - The optical scanning device. 2. A ray deflected by rotating a deflection prism.
2. The laser light scanning device according to claim 1, wherein the rotating means for scanning the laser spot light in an arc shape is a pulse motor. 3. A plurality of semi-cylindrical lenses whose rotation angles can be adjusted to adjust the irradiation angles of a plurality of laser spot lights that are linearly scanned are rotated by a pulse motor. The laser light scanning device according to claim 1. 4. The laser optical scanning device according to claim 1, wherein the pitch varying means is a belt to which a plurality of semi-cylindrical lenses are connected, and a pulse motor for driving and driving the belt. . 5. A laser soldering device for use as a laser beam irradiating means.
2. The laser optical scanning device according to any one of 1.