JPH0852582A - Laser heating method, device and laser heating tool used therefor - Google Patents

Abstract

PURPOSE:To provide a high conversion efficiency from electric power to optical intensity as well as a high converging efficiency, to easily control ambient thermal influence, to have a compact size, long life, low device cost and low running cost and to suit laser heating in soldering etc. CONSTITUTION:A part A to be heated is convergently irradiated and heated by a laser beam L emitted from a semiconductor laser 1 and converged in the shape of a prescribed irradiation spot while using and driving the semiconductor laser 1 for a light emission required for the heating; the semiconductor laser 1 is used plurally combined, enabling radiation directly to the periphery by means of a radiator in contact with the semiconductor laser 1 as it is driven.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser heating method and apparatus for performing non-contact heating using light to perform soldering and correction of the same, and a heating tool used therefor.

[0002]

2. Description of the Related Art As a non-contact heating method using light, the one shown in FIG. 16 is practically used. This is a lamp light source a
The light from the lens is focused on a point c by a reflection shade b which is a concave mirror, and the heated portion such as the soldering portion is irradiated with the light at the point c where the light is focused, so that the solder of the soldering portion is removed. It is melted and soldered, and this is corrected.

According to such a heating method, light can be concentrated and irradiated even on a fine portion, and local heating can be performed in a non-contact manner without affecting the surroundings. It is suitable for soldering electronic circuits.

On the other hand, a technique of soldering or boring using a YAG laser or a cutting technique has been developed.

[0005]

By the way, a relatively large light intensity is required for heating by irradiation of light and for soldering and correction thereof. To satisfy this, a lamp using halogen or xenon is used as the lamp light source a. However, such a lamp light source a has a short life, and it is necessary to replace the lamp light source a in several hundred hours, for example. In addition, these lamps have a light conversion efficiency of 10 which converts electric power into light.
%, A large driving power is required, and since the light conversion efficiency is low, the heat generation amount of the lamp light source a is large and a powerful cooling device and prevention of thermal influence on the surroundings are required. Is not suitable for a fine electronic circuit board having a heated portion, and the device cost and running cost are high.

In the case of the YAG laser, the light is concentrated and emitted to obtain a laser light having a straight traveling property, so that the light collection efficiency is high. However, the efficiency of converting electric power into light energy is 2,
Since it is extremely low at 3%, a larger drive power is required, resulting in an increase in the size of the device and a high device cost and running cost. Moreover, since the life of the lamp is short, it is not often used for mass production of electronic circuit boards which are frequently heated.

On the other hand, it may be considered to use a semiconductor laser, but the output intensity of the laser light of the semiconductor laser is not yet sufficient, and the semiconductor laser is used in a general method in which the laser light from the semiconductor laser is guided by an optical fiber and irradiated. Since the laser light from No. 2 has a large loss due to the optical fiber, the necessary and sufficient light intensity cannot be obtained.

An object of the present invention is to solve the above-mentioned problems of the related art, and soldering of an electronic component which has a high efficiency of converting electric power into light intensity and a high light-collecting efficiency and which is free from static electricity or thermal influence and The main object of the present invention is to provide a laser heating method, which is suitable for repairing, etc., is small in size, has a long life, and has low apparatus cost and running cost, and an apparatus and a laser heating tool used therefor.

[0009]

In order to achieve the above-mentioned object, the laser heating method of the present invention uses a semiconductor laser having an emission capacity necessary for heating and driving the semiconductor laser while The first feature is that the emitted laser light is directly transmitted to the condensing optical system and condensed into a required shape to condense and irradiate the heated portion and heat the heated portion with light. .

In order to achieve the above-mentioned object, the laser heating method of the present invention emits from the semiconductor laser while driving the semiconductor laser of the light emission capacity required for heating under a predetermined current limit. The laser light to be generated is directly transmitted to the condensing optical system and condensed into a required shape to condense and irradiate the heated portion, and the heated portion is heated by the second.
It is a feature of.

In these, it is preferable to drive the semiconductor laser under the conditions according to the temperature profile which is preset and stored with respect to the laser light emitted from the semiconductor laser, while being read. It is also preferable to use a plurality of semiconductor lasers in combination.

Further, when the semiconductor laser is driven, it is preferable that a heat radiator in contact with the semiconductor laser radiates heat to the surroundings.

In order to achieve the above-mentioned object, the laser heating device of the present invention is one condensing optical system for directly transmitting a semiconductor laser and a laser beam emitted from this semiconductor laser to condense it into a required shape. It mainly comprises a laser heating tool having a system, a sensor for detecting the temperature of the laser light condensing irradiation portion, and a feedback control means for controlling the drive current of the semiconductor laser according to the output from the sensor. Characterize.

In this case, the semiconductor laser is provided with a radiator located inside and in contact with the semiconductor laser and provided with a cooling passage therein, and cooling air blowing means for blowing cooling air to the cooling passage of the radiator. It is preferable that it is one.

The cooling passage may be a plurality of holes penetrating from the rear end to the front end of the radiator, and may be formed in a straight or spiral shape.

Further, it is preferable that the apparatus further comprises a blowing means for blowing air to the laser beam focusing and irradiating section.

The blower means is preferably one that guides the exhaust air from the radiator by the cooling blower means, and has a heating means for heating the exhaust gas from the radiator by the cooling blower means to the condensing irradiation section. Is also suitable.

In order to achieve the above-mentioned object, the laser heating tool of the present invention comprises a plurality of semiconductor lasers linearly arranged in a direction perpendicular to the emitting direction, and lasers emitted from these semiconductor lasers. The first feature is that the light-collecting optical system is configured to directly transmit light and collect the light at one point.

In this case, the condensing optical system includes a first cylindrical lens for condensing laser light emitted from a plurality of linearly arranged semiconductor lasers into parallel strip light, and the first cylindrical lens. It is preferable to include a second cylindrical lens that collects the band-shaped light that has passed through in the width direction and a convex lens that collects the light that has passed through the second cylindrical lens at one point.

Further, it is preferable that the semiconductor lasers are arranged in a plurality of rows, and the semiconductor lasers in a row arranged off the irradiation optical axis plane passing through the irradiation optical axis and parallel to the column direction of the semiconductor laser are It is more preferable that the tip side is inclined so that the laser light emitted from these is incident on the irradiation optical axis surface or along the vicinity thereof.

Further, it is preferable that the semiconductor laser is provided with a heat radiator which is in close contact with the semiconductor laser and is provided with a cooling hole therein, and a blowing means for blowing air to the cooling hole of the heat radiator.

Further, it is preferable that an insulating layer is provided between the tool cover and the radiator.

In order to achieve the above object, the laser heating tool of the present invention appropriately transmits a plurality of appropriately arranged semiconductor lasers and the respective laser beams emitted from these respective semiconductor lasers, and appropriately. The second characteristic is that the light collecting optical system for collecting light in a linear shape is provided.

In this case, it is preferable that the light is collected on a plurality of sides that are continuous or not continuous.

[0025]

In the above-described structure of the first feature of the laser heating method of the present invention, the semiconductor laser having the light emission capacity required for heating is used, and the light emission capacity required by the semiconductor laser is supplied by the semiconductor laser. In addition to taking advantage of the characteristics of high conversion rate to laser light and the fact that the laser light is emitted straight from the semiconductor laser in one direction and has good condensing properties and high irradiation efficiency,
Higher heat conversion efficiency than when using a lamp light source or optical fiber by directly transmitting the laser light emitted from the semiconductor laser to the condensing optical system, condensing it into the required shape and irradiating the heated part. Since the necessary amount of light emitting capacity is utilized in, the necessary power for driving the semiconductor laser while sufficiently achieving non-contact heating using light by locally heating the minute heated portion, and the semiconductor laser The light capacity required for this is reduced to reduce heat generation, and it can be applied to the light heating of electronic parts that are weak to them without any problems, and it is small and has a long life, and the device cost and running cost are reduced.

In the above-mentioned configuration of the second feature of the laser heating apparatus of the present invention, the semiconductor laser is driven under a predetermined current limit, so that the semiconductor laser is operated and controlled so as to be driven with an excessive current. It is possible to prevent the laser from being destroyed.

In this case, in the configuration in which the semiconductor laser is driven under these conditions while the temperature profile preset and stored for the laser light emitted from the semiconductor laser is read out, the temperature profile required for heating is preset. Just by setting and storing this, the semiconductor laser will be driven over time so as to obtain the heating state according to this setting, so heating under any condition can be repeated accurately and automatically. You can

Further, in a structure in which a plurality of semiconductor lasers are used in combination, the laser light emitted from the plurality of semiconductor lasers is condensed and all the respective light intensities are concentrated and heated on the heated portion. Therefore, the required light emitting capacity can be easily obtained by using a semiconductor laser which is usually used.

Further, when the semiconductor is driven, the heat dissipation member in contact with the semiconductor laser radiates heat to the surroundings.
Coupled with the fact that the amount of heat generated is smaller than the required optical capacity of the semiconductor laser, it is possible to sufficiently cool the device without increasing the size of the device and prevent thermal influence on the surroundings.

In the above-mentioned configuration, which is the main feature of the laser heating apparatus of the present invention, the laser heating tool has a plurality of semiconductor lasers and a condensing optical system that condenses laser light emitted from these semiconductor lasers at one point. Therefore, the same effect as the laser heating method in the case of using a plurality of semiconductor lasers described above can be exhibited, and the feedback control means detects the drive current of the semiconductor laser from the condensing section. Since the control is performed on the basis of the temperature information from, it is possible to accurately achieve any automatic heating by light irradiation without temperature variations due to the influence of the environmental temperature.

Further, a heat radiating body which is provided around the semiconductor laser so as to be in contact with the semiconductor laser and has a cooling passage provided therein,
In the structure provided with the cooling air blowing means for blowing the cooling air to the cooling passage of the radiator, even if the semiconductor laser generates heat to be driven, the semiconductor laser is directly conducted to the radiator and is provided on the radiator. The heat from the semiconductor laser conducted to the radiator is forcibly taken away from the radiator by the heat radiation holes and the cooling air blown by the cooling air blowing means to the heat radiator, so that the heat from the semiconductor laser can be radiated efficiently and quickly. It is possible to prevent the influence of heat on the surroundings.

In the structure provided with the blowing means for blowing the laser light to the condensing and irradiating part, smoke and the like generated from the heated part which is converging and irradiating and heating are excluded, so that smoke particles are not generated in the heated part. Adhesion can be prevented and the heated portion can be easily observed from the outside.

In the structure in which the air blowing means guides the exhaust air from the radiator by the cooling air blowing means, only a duct for this air blowing is required, and therefore a fan or the like for this air blowing is required and the structure becomes complicated. This can be prevented, and the waste heat from the radiator can be assisted in the light heating in the converging irradiation unit.

In the structure having the heating means for heating the exhaust gas from the heat radiator by the cooling air blowing means which guides the light to the condensing irradiation part, the exhaust gas from the heat dissipating body is heated to further raise the temperature and then blown to the condensing irradiation part. Therefore, it is possible to enhance the auxiliary function by the blowing of the light heating.

In the above-mentioned constitution of the first feature of the laser heating tool of the present invention, while exhibiting the same operation as the laser heating method using the plurality of semiconductor lasers, the laser heating tool is further linearly formed in the direction perpendicular to the emitting direction. Since laser light emitted from a plurality of arranged semiconductor lasers is directly transmitted through one condensing optical system and condensed at one point, the semiconductor laser and the condensing laser are used to perform light intensity compensation by the plurality of semiconductor lasers. The optical system can be made compact with a flat and low-profile array, and the array area in which the exposed area of each semiconductor laser is large makes it easy to radiate heat to the surroundings and further reduce the thermal effect. can do. Moreover, the local heating efficiency can be further improved by the irradiation of converging the laser light on one point, and it is suitable when the heated portion is minute.

In this case, the condensing optical system includes the first cylindrical lens for condensing the laser light emitted from the plurality of linearly arranged semiconductor lasers into parallel strip light, and the first cylindrical lens. In a configuration including a second cylindrical lens that condenses the band-shaped light that has passed through in the width direction and a convex lens that condenses the light that has passed through the second cylindrical lens at one point, two directions that are orthogonal to each other by the two cylindrical lenses are used. To a single point and then to a single point with a single convex lens.
With a simple configuration using two lenses, it is possible to efficiently focus the laser beam generated in the band shape at one point.

Further, in a structure in which the semiconductor lasers are arranged in a plurality of rows, the number of semiconductor lasers to be used can be reliably increased by the number of arrays without impairing the advantage of the flat and low-profile array.

In this case, the laser beams emitted from the semiconductor lasers in the rows arranged outside the irradiation optical axis plane passing through the irradiation optical axis and parallel to the column direction of the semiconductor lasers are on the irradiation optical axis plane or in this direction. In the configuration in which the tip side is inclined so that the incident light is incident along the vicinity, the laser light emitted from each row of the semiconductor lasers is arranged along the optical axis plane of the condensing optical system. The light beams can be made to overlap each other or be incident so as to be adjacent to each other, and light can be efficiently condensed at one point sharing one condensing optical system.

Further, a radiator having a cooling hole provided inside is in close contact with the semiconductor lasers arranged in a straight line,
In the structure provided with a blowing unit that blows air to the cooling holes of the radiator, the heat of the semiconductor laser can be efficiently conducted to the radiator by utilizing the size of the exposed area of the semiconductor laser. The cooling air from the cooling air blowing means is blown to the cooling holes of (1) to enhance the heat radiation efficiency of the heat radiator, and in addition, the heat influence on the surroundings due to the heat generation of the semiconductor laser can be more surely prevented.

Further, in the structure in which the insulating layer is provided between the tool cover and the radiator, the radiator can be insulated from the surroundings by the insulating layer inside the tool cover. As a metal member having good conductivity, it is possible to sufficiently prevent the static electricity from affecting the surroundings while improving the heat dissipation performance of the semiconductor laser.

In the above-mentioned constitution of the second feature of the laser heating tool of the present invention, the laser light emitted from the semiconductor lasers arranged appropriately is directly transmitted through the condensing optical system to be condensed in an appropriate line shape. Therefore, in addition to exhibiting the same effect as the laser heating method using a plurality of semiconductor lasers, in the case where the soldering portions are arranged in a straight line at a fine pitch, such as a package-type multi-pin electronic component, All of the soldering parts arranged in a straight line can be simultaneously irradiated with the laser light condensed in a line shape, and a plurality of heated parts can be heated at the same time, and the line-shaped light collection becomes uniform. The simultaneous heat treatment of the plurality of heated portions can be uniformly achieved.

In this case, line-shaped light collection is performed continuously,
Alternatively, in a configuration in which multiple sides that are not continuous are formed,
Simultaneous heating of the plurality of heated portions can be similarly applied to a case where the plurality of heated portions are arranged continuously or in a plurality of non-continuous sides.

[0043]

EXAMPLES The laser heating method and apparatus of the present invention and the laser heating tools used therein will be specifically described below with reference to several examples.

1 to 4 show a laser heating apparatus as a first embodiment of the present invention. With reference to FIG. 1, the laser heating apparatus of the present embodiment uses a semiconductor laser 1 having an emission capacity necessary for heating and driving the semiconductor laser 1, while collecting laser light L emitted from the semiconductor laser 1. It is used for heating the heated portion A by condensing and irradiating the heated portion A by directly transmitting the light through the system 2 and condensing it into a required shape.

According to such a heating method, by using the semiconductor laser 1 having an emission capacity required for heating, the semiconductor laser 1 can convert the required emission capacity of the semiconductor laser 1 into a light intensity of electric power. The laser beam L emitted from the semiconductor laser 1 has a high characteristic and the laser beam L is emitted from the semiconductor laser 1 in one direction and has a straight-line characteristic and has a good converging property and a high irradiation efficiency. By directly transmitting the light and condensing it into a required shape and irradiating the heated portion A, the necessary light emitting capacity can be utilized with higher heat conversion efficiency than in the case of using a lamp light source or an optical fiber. Static electricity can be achieved by sufficiently heating the minute heated portion locally to achieve non-contact heating using light, while suppressing the required power for driving the semiconductor laser 1 and the optical capacity required for the semiconductor laser 1. And heat generation Less then, can be applied without problems to the optical heating of the sensitive electronic components of these, compact, long life, also reduces equipment cost and running cost.

Further, it can be utilized as a viscosity control by heating control, chemical synthesis through glass, etc., and also as a YAG rod end face excitation light source by a semiconductor laser.

As shown in FIGS. 1 and 2, the laser heating apparatus according to the present embodiment has a specific structure in which a plurality of semiconductor lasers 1 for obtaining a required light emitting capacity and the semiconductor lasers 1 emit light. A laser heating tool 3 having one condensing optical system 2 for condensing each laser beam L at one point, and a drive circuit 4 for connecting and driving a power source 6 to the semiconductor laser 1 are provided. A current limiting circuit 5 for limiting the drive current supplied from the power source 6 to the semiconductor laser 1 is provided.

As a result, when each semiconductor laser 1 is driven by the drive circuit 4, by limiting the drive current from the power source 6 by the drive circuit 4 by the current limiting circuit 5, an operation for driving with an excessive current or Controlled semiconductor laser 1
Can be prevented from being destroyed.

The characteristics of the semiconductor laser 1 are destroyed when a prescribed current I _L is exceeded as shown in FIG. Therefore, in the current limiting circuit 5 of the present embodiment, as shown in FIG. 3, the base voltage of the transistor 11 is current limited by the dividing resistor 12 and the Zener diode 13 for stabilizing the voltage. Further, as shown in FIG. 5B, the semiconductor laser 1 is destroyed because the current exceeds the specified value even if it exceeds a certain voltage V _l. The high speed diode 14 as shown in FIG. 4 is protected by applying voltage limitation. Note that, instead of the diode 14, a high-speed Zener diode 15 shown by a virtual line in FIG. 4 may be used to limit the voltage.

The plurality of semiconductor lasers 1 is a semiconductor laser array 17 in which a support member 16 is linearly arranged and held in a direction perpendicular to the emission direction of the laser light L as shown in FIG. It can be handled as one in terms of mounting and driving.

The condensing optical system 2 includes a semiconductor laser array 17
The respective laser lights L emitted from the respective semiconductor lasers 1 in parallel in a row are converted into strip-shaped parallel light by the first cylindrical lens 18, and the parallel strip-shaped light which has passed through the first cylindrical lens 18 is The band-shaped light is condensed in the width direction by the cylindrical lens 19, and the laser light L
Is focused on one point so that the heated portion A can be spot-irradiated.

As a result, the laser light L emitted from the plurality of semiconductor lasers 1 linearly arranged in the direction perpendicular to the emission direction is condensed by the condensing optical system 2 at one point. Therefore, in order to perform the light intensity compensation, the semiconductor laser 1 and the condensing optical system 2 can be made as a flat and low-profile array to make the whole compact, and the exposed area of each semiconductor laser 1 must be large. By doing so, it is possible to easily radiate heat to the surroundings and to further reduce the thermal influence. Moreover, the local heating efficiency can be further improved by irradiating the laser light L focused on one point, and it is suitable when the heated portion A is minute. Moreover, the necessary condensing by the condensing optical system 2 can be achieved only by using two cylindrical lenses having a simple entrance / exit surface that is a cylindrical surface, and the structure is simple.

Both the first and second cylindrical lenses 18 and 19 may have cylindrical entrance and exit surfaces, or only one may have a cylindrical surface and the other a flat surface. , These combinations can be freely designed as needed.

FIGS. 6 and 7 show a laser heating apparatus as a second embodiment of the present invention. The laser heating apparatus of the present embodiment is different mainly in that the condensing property is improved and that the laser heating tool 3 is provided with a cooling structure.

Explaining these different points, in the condensing optical system 2, in addition to the two cylindrical lenses 18 and 19 in the first embodiment, the laser light L emitted from the second cylindrical lens 19 is converted into a convex lens 20. By only using it, the light can be condensed into a smaller size, the condensing performance can be improved without making the lens structure particularly complicated, and the heated portion A can be irradiated with a smaller irradiation spot B. The heating of the portion can be achieved with higher thermal efficiency. The first cylindrical lens 18 has a columnar shape, and has an advantage that processing is easy.

A heat radiator 21 is provided around the semiconductor laser array 17 so as to be in close contact therewith. The radiator 21 is made of aluminum and has a columnar shape, and a radial notch 21a is formed in the rear half portion from the rear end portion. When the semiconductor array 17 is accommodated in the notch 21a and both side surfaces 21b of the notch 21a are in close contact with the outer surfaces of the electrodes 17a applied to both front and back surfaces thereof, each semiconductor laser 1 of the semiconductor laser array 17 is driven. The heat generated in the above is conducted to the radiator 21 so that it can be easily radiated.

In order to dissipate the heat, a large number of cooling passages 21c are formed in the heat dissipating body 21 so as to pass through the heat dissipating body 21 in the axial direction.
A cooling fan 22 is provided as a cooling air blower that blows cooling air to the heat radiation holes 21c. Therefore, even if the semiconductor laser 1 generates heat due to being driven, it is well conducted to the heat radiator 21, and by the cooling passage 21c provided in the heat radiator 21 and the cooling air blown to the cooling passage 21c by the cooling fan 22. Since the heat from the semiconductor laser 1 conducted to the radiator 21 is efficiently removed from the radiator 21, the heat of each semiconductor laser 1 can be quickly and sufficiently radiated.

Further, in the present embodiment, the entire area including the radiator 21, the cooling fan 22, and the condensing optical system 2 is
A tool cover 23 is provided to give a straight appearance and a unity structure that is easy to handle and use as a whole tool. Exhaust holes 23a in four directions are formed in a portion between the radiator 21 and the first cylindrical lens 18, and the cooling fan 22 shares a part of the tool cover 23 with a blower guide, while The outside air is sucked from the end and sent as cooling air into the cooling passage 21c, and is exhausted to the four sides around the tool cover 23 through the exhaust holes 23a, so that the semiconductor laser 1 can be radiated with a simple structure. it can. Further, an insulating layer 29 coated with ceramics is provided between the tool cover 23 and the radiator 21, so that even if the radiator 21 is made of metal, external influence of static electricity can be prevented.

In addition, in the front half of the radiator 21, a bored hole 2 having a rectangular cross section reaching the notch 21a in the latter half.
1d is formed to prevent eclipse from occurring in each laser beam L arranged in a band and emitted from each semiconductor laser 1 arranged in a straight line in the notch 21a. The hole 21d is only required to prevent the laser light L from being shaken, but the first half of the radiator 21 is advantageous for cooling with the cooling passage 21c as much as possible. It is sized and shaped to the minimum required to prevent it.

According to the experiments conducted by the present inventors, 50 W
For the semiconductor laser array 13 that generates heat,
Reference numeral 1 is a diameter of 30 mm, a length of 40 mm or more, and a diameter of the cooling passage 21c of about 3 mm to 5 mm, which can suppress the temperature around the semiconductor laser array 13 to about 10 ° C. and is easy to handle and easy to use without any practical problems It became. Further, in this embodiment, the cooling fan 22 incorporated in the laser heating tool 3 is used as the cooling air blowing means, but it is also possible to blow the air from the external cooling air air blowing means.

The air volume of the cooling fan 22 may be controlled so that the temperature of the semiconductor laser array 17 is constant. As a result, the wavelength can be locked and it can also be used as an end face excitation light source for the YGA rod.

Further, the electrodes 17a are provided on the front and back sides of the semiconductor laser array 17, but in order to dissipate the heat of the semiconductor laser 1, even if the electrode 17a is provided between the semiconductor laser array 17 and the heat radiator 21, the heat radiator 21 is thermally provided. It can be regarded as being in direct contact with the semiconductor laser 1. However, the radiator 21 is directly connected to the semiconductor laser 1
It is also possible to make contact with the and make it act as an electrode.

In this embodiment, the radiator 21 is made of a conductive material and is in direct contact with the electrodes. However, a non-conductive radiator may be used. In this case, a space between the tool cover 23 and the radiator 21 may be used. The insulating layer 29 can be omitted.

The condensing optical system 2 uses two cylindrical lenses 18 and 19 and one convex lens 20, but the convex lens 20 can be formed into an aspherical shape depending on the spot shape of the laser light incident on it. . Convex lens 20
In the case of having an aspherical shape, it is possible to condense light onto one point by this one. Further, the condensing optical system 2 may have a combined structure of various lenses.

Although the cooling passage 21c is a circular hole, the rectangular hole may have any cross-sectional shape, as a matter of course. Further, although the cooling passage 21c is formed in a linear shape in this embodiment, it is needless to say that the cooling passage 21c may be formed in a spiral shape.

FIG. 8 shows, as a third embodiment of the present invention, another laser heating tool which can replace the ones shown in the first and second embodiments.

The laser heating tool 3 of this embodiment is characterized in that a plurality of semiconductor lasers 1 linearly arranged in a direction perpendicular to the emitting direction are provided in a plurality of rows.

Thus, the number of semiconductor lasers to be used can be increased by the number of arrays without impairing the advantage that the plurality of semiconductor lasers 1 arranged in a straight line have the flat and bulky array. In this embodiment, they are arranged in two rows above and below.

In particular, in the present embodiment, the laser beams L emitted from the upper and lower rows of the semiconductor lasers 1 arranged outside the plane of the irradiation light axis passing through the irradiation light axis 31 and parallel to the row direction of the semiconductor lasers 1. Is arranged so that the tip end side is closer to the irradiation optical axis surface so that the light enters on the irradiation optical axis surface or along the vicinity thereof.

As a result, the laser beams L emitted from the semiconductor lasers 1 in the respective columns are made to overlap each other along the irradiation optical axis plane of the condensing optical system 2 with the luminous flux thickness d, or to be incident so as to be adjacent to each other. Therefore, one condensing optical system 2 can be shared and the light can be efficiently condensed at one point. Although the condensing optical system 2 in this embodiment is the same as that in the first embodiment, it may be the same as that in the second embodiment, and the laser beam L is irradiated in a predetermined shape. Any configuration may be used as long as it condenses to obtain the spot B.

In the experiment conducted by the present inventor, an irradiation spot B of 0.3 mm × 1 mm was obtained for a semiconductor laser output of 10 W.

9 and 10 show a fourth embodiment of the present invention. In the second embodiment, the laser light L emitted from each semiconductor laser 1 is preset as shown in FIG. A sequencer 33 shown in FIG. 10 as a storage means for storing the temperature profile 32 to be stored,
A microcomputer 34 as a control means for controlling the drive circuit 24 so as to drive the semiconductor laser 1 according to the profile stored in the sequencer 33, and a sensor 35 for detecting the temperature of the condensing and irradiating part of the laser light L. Equipped with a semiconductor laser 1 according to the output from the sensor 35.
The drive current is controlled by feedback using the internal function of the microcomputer 34.

As a result, the temperature profile required for the heat treatment is set in advance and stored in the sequencer 33, so that the microcomputer 34 drives the semiconductor laser 1 so as to obtain the heated state according to this setting. Therefore, the heat treatment under any condition can be repeatedly and automatically achieved.

Further, since the driving current of the semiconductor laser 1 is controlled by the microcomputer 34 based on the temperature information from the sensor 35 which is actually detected from the condensing irradiation unit, what kind of heat treatment by light irradiation should be performed. Can also be achieved accurately with automatic control.

A concrete example of data processing using the sequencer 33 by the microcomputer 34 is shown in FIG. 10. The microcomputer 34 is, for example, a notebook personal computer, various terminals, a palmtop personal computer, a disctop personal computer or the like. The temperature profile information 32 used by operating the mouse 35 is converted into data for the sequencer 33 capable of analog or digital output, and RS2
It is sent to the sequencer 33 via the communication circuit 36 such as 32C. The sequencer 33 stores the data and pre-programs it so that it can be handled as timer data or the like and the current output can be set according to the passage of time. As a result, a current that changes from moment to moment flows through the semiconductor laser array 17. Can be controlled.

FIG. 11 shows a fifth embodiment of the present invention, which is still another laser heating tool 3 that can replace the laser heating tool 3 used in the second to fourth embodiments.

The laser heating tool 3 of this embodiment is provided with a blowing means 41 for blowing the laser light L to the spot irradiation portion.

Therefore, the smoke C or the like generated from the heated portion A which is being irradiated with the spot and being heated is eliminated by the air blowing from the blowing means 41, so that the smoke particles are prevented from adhering to the heated portion A. It is possible to make the appearance of the heated portion A easy, and it is convenient for work management of heat treatment.

Needless to say, the air may be blown from outside the laser heating tool 3.

The blower means 41 guides the exhaust air from the radiator 21 by the cooling fan 22 to the non-heated portion A, and since only the duct 42 for blowing the air is required, the structure becomes particularly complicated. Such a situation can be prevented, and since the exhaust gas has taken away heat from the radiator 21, it can be an aid in heating the heated portion A.

In this embodiment, the heat dissipation hole 2 of the heat dissipation member 21 is used.
If 1c is filled with a liquid and is vaporized by blowing air, heat dissipation by the radiator 21 is promoted and the cooling efficiency of the semiconductor array 13 can be improved. Also,
By inserting the heat pipe into the cooling passage 21c, the heat radiation area in the heat radiation hole 21c can be increased and the cooling efficiency of the semiconductor laser array 17 can be improved. Such improvements can be applied to the second to fourth embodiments.

Further, in the present embodiment, there is provided the heating means 43 for heating the exhaust gas from the radiator 21 by the cooling fan 22 which leads to the condensing irradiation section. As a result, even if the temperature of the exhaust gas from the radiator 21 is low, it is heated and blown to the condensing irradiation unit, so that the temperature compensation of the heated portion A can be achieved more advantageously. . As the heating means 43, it is preferable to use a heater as in this embodiment. The heating means 43 is driven by a dedicated heater power source 44. However, it is not limited to this.

FIG. 12 shows a sixth embodiment of the present invention, in which the laser heating tool 3 is attached to the working shaft 52 of the automatic working machine 51 as one tool to be used by switching. 13 shows a seventh embodiment of the present invention, in which the work robot 53
It is adapted to be used as one tool of the turret tool 55 which is detachably attached to the working arm 54 of the above. As a result, the laser heating tool 3 is appropriately used in combination with various working steps so that soldering, correction thereof, and other heating processing can be performed.

FIG. 14 shows an eighth embodiment of the present invention, in which each laser beam L emitted from each semiconductor laser 1 of the semiconductor laser array 17 is formed by a cylindrical lens 18 and a lens 19 having a condensing or expanding characteristic. The light is collected in a line.

As a result, the laser light L emitted from the semiconductor laser 1 can be uniformly condensed as a linear irradiation spot B1, and soldering can be performed as in the package type multi-pin electronic component E such as the QFP type. In the case where the attachment parts are arranged in a straight line at a fine pitch, all of the linearly arranged soldering parts are simultaneously and uniformly irradiated with the laser light L that is uniformly condensed in a line shape, It is possible to uniformly heat-treat the heated portion.

In particular, in this embodiment, the line-shaped light collecting is made into four continuous or non-continuous sides.
On the four sides of the package-type multi-pin electronic component E, a large number of linearly arranged soldering portions can be uniformly heat-treated at the same time.

FIG. 15 shows a ninth embodiment of the present invention, in which the diffraction grating 61 is used so that the condensing light forming the linear irradiation spot B1 can be obtained on two parallel sides facing each other. is there. As a result, the soldering portions of the package-type multi-pin electronic component E, which are linearly arranged on two opposite sides, can be heat-treated uniformly at the same time.

Depending on the design of the diffraction grating 61, the laser light L from the semiconductor laser 1 arranged in an appropriate line may be formed.
Can be focused so as to form an appropriate linear irradiation spot such as a circle or a polygon.

[0089]

According to the first feature of the laser heating method of the present invention, the semiconductor laser has a high conversion rate of electric power into light intensity for the required light emission capacity of the semiconductor laser. The laser beam emitted from the laser in one direction is straightforward and has good focusing properties and high irradiation efficiency. By irradiating the portion to be heated after condensing it into a shape, the necessary light emitting capacity can be utilized with high heat conversion efficiency compared to the case of using a lamp light source or an optical fiber. While achieving satisfactory non-contact heating using local heating with light, the power required to drive the semiconductor laser and the optical capacity required for the semiconductor laser are kept small to reduce the generation of static electricity and heat. Weak electronic component light Can be applied without problems to heat a small, long life, also reduces equipment cost and running cost. Further, it can be used as a viscosity control by heating control, chemical synthesis through glass, etc., or as a YAG rod end face excitation light source by a semiconductor laser.

According to the second feature of the laser heating method of the present invention, it is possible to prevent the semiconductor laser from being destroyed by being operated or controlled by driving with an excessive current in driving the semiconductor laser. can do.

In these cases, according to the configuration in which the semiconductor laser is driven under the conditions according to the temperature profile which is preset and stored with respect to the laser light emitted from the semiconductor laser is read out, By simply setting and storing the temperature profile required for heating in advance, the semiconductor laser is automatically driven with the passage of time so as to obtain the heating state according to this setting, so heating under any conditions is possible. Exactly repeatable can be achieved automatically.

According to the structure in which a plurality of semiconductor lasers are used in combination, the laser light emitted from the plurality of semiconductor lasers is condensed and all the respective light intensities thereof are concentrated on the heated portion and heated. Therefore, the required light emitting capacity can be easily obtained by using a semiconductor laser which is usually used.

Further, when the semiconductor is driven, the heat dissipation amount is smaller than the required optical capacity of the semiconductor laser according to the structure in which the heat dissipation body in contact with the semiconductor laser directly radiates heat to the surroundings. Together, it is possible to sufficiently cool the device without increasing the size of the device and prevent thermal influence on the surroundings.

According to the main feature of the laser heating apparatus of the present invention, the same operation as the laser heating method in the case of using a plurality of semiconductor lasers described above can be exhibited, and the feedback control means is used for the semiconductor laser. Drive current,
Since the control is performed based on the temperature information from the sensor that is actually detected from the light collecting unit, any automatic heating by light irradiation can be accurately achieved without variations in temperature due to the influence of environmental temperature.

Further, a heat radiating body provided around the semiconductor laser so as to be in contact with the semiconductor laser and having a cooling path provided therein,
According to the structure provided with the cooling air blowing means for blowing the cooling air to the cooling passage of the radiator, even if the semiconductor laser generates heat to be driven, the heat is directly conducted to the radiator and the heat is radiated. Since the heat from the semiconductor laser conducted to the heat radiator is forcibly taken away from the heat radiator by the heat radiation hole provided in the body and the cooling air blown by the cooling air blowing means to the heat radiator, the heat from the semiconductor laser can be efficiently emitted. Moreover, the heat can be dissipated quickly, and the influence of heat on the surroundings can be prevented.

According to the structure provided with the blowing means for blowing the converging and irradiating part of the laser light, smoke and the like generated from the heated part which is converging and irradiating and heating is excluded. It is possible to prevent smoke particles from adhering and to make it easier to observe the heated portion from the outside.

According to the structure in which the blower means guides the exhaust air from the radiator by the cooling blower means, only a duct for this blower is required, so a fan or the like for this blower is required. It is possible to prevent the structure from becoming complicated, and it is possible to assist the waste heat from the radiator in the light heating in the converging irradiation unit.

According to the structure having the heating means for heating the exhaust gas from the heat radiator by the cooling air blowing means guided to the condensing irradiation section, the exhaust gas from the heat radiator is heated to further raise the temperature, and then the light is condensed. Since the air is blown to the irradiation unit, it is possible to enhance the auxiliary function by the blowing of the light heating.

According to the above-mentioned constitution of the first feature of the laser heating tool of the present invention, while exhibiting the same operation as the laser heating method using the plurality of semiconductor lasers, the laser heating tool is further oriented in the direction perpendicular to the emitting direction. Laser light emitted from a plurality of semiconductor lasers arranged in a straight line is directly transmitted through one condensing optical system and condensed at one point. Therefore, in order to perform light intensity compensation by a plurality of semiconductor lasers, The laser and focusing optics can be made compact with a flat and low-profile array, and the exposed area of each semiconductor laser becomes large, which makes it easier to radiate heat to the surroundings. It can be even less. Moreover, the local heating efficiency can be further improved by the irradiation of converging the laser light on one point, and it is suitable when the heated portion is minute.

In this case, the condensing optical system includes the first cylindrical lens for condensing the laser beams emitted from the plurality of linearly arranged semiconductor lasers into parallel band-shaped light, and the first cylindrical lens. According to the configuration including the second cylindrical lens that collects the band-shaped light that has passed through in the width direction and the convex lens that collects the light that has passed through the second cylindrical lens at one point, the two cylindrical lenses are used. Converging in two orthogonal directions and aiming at one point,
Since this is further condensed to one point by one convex lens, a simple configuration using three simple lenses
The band-shaped laser light can be efficiently focused at one point.

Further, according to the structure in which the semiconductor lasers are arranged in a plurality of rows, the number of semiconductor lasers to be used can be surely increased by the number of arrangements without impairing the advantage of the flat and low-profile arrangement. You can

In this case, the semiconductor lasers in the rows arranged outside the irradiation optical axis plane passing through the irradiation optical axis and parallel to the column direction of the semiconductor lasers emit laser light from the irradiation optical axis plane or on the irradiation optical axis plane. According to the configuration in which the tip side is inclined so that the tip end side is closer to the irradiation optical axis surface so as to be incident along the vicinity, each of the laser beams emitted from the semiconductor lasers in each row is provided in the condensing optical system. Stacked along the optical axis plane,
Alternatively, the light can be made incident so as to be adjacent to each other, and light can be efficiently condensed at one point sharing one condensing optical system.

Further, a heat radiating body having a cooling hole in close contact with the semiconductor lasers arranged in a straight line,
According to the configuration including the air blowing unit that blows air to the cooling hole of the radiator, the heat of the semiconductor laser can be efficiently conducted to the radiator by utilizing the size of the exposed area of the semiconductor laser. It is possible to blow the cooling air from the cooling air blower to the cooling holes of the heat radiator to improve the heat radiation efficiency of the heat radiator, and more reliably prevent the heat influence on the surroundings due to the heat generation of the semiconductor laser. .

According to the structure in which the insulating layer is provided between the tool cover and the radiator, the radiator can be insulated from the surroundings by the insulating layer inside the tool cover. As a metal member with good thermal conductivity, which is advantageous for
It is also possible to sufficiently prevent static electricity from affecting the surroundings.

According to the second feature of the laser heating tool of the present invention, the laser light emitted from the appropriately arranged semiconductor lasers is directly transmitted to the condensing optical system to be condensed in an appropriate line shape. In addition to exhibiting the same effect as the laser heating method using a plurality of semiconductor lasers, in the case where the soldering parts are arranged in a straight line at a fine pitch such as a package-type multi-pin electronic component, these straight lines are used. All of the soldering parts arranged in a line are simultaneously irradiated with the laser light condensed in a line shape, and a plurality of heated parts can be heated at the same time, and the line-shaped light collection becomes uniform, The simultaneous heat treatment of the plurality of heated portions can be uniformly achieved.

In this case, line-shaped light collection is performed continuously,
Alternatively, according to a structure in which a plurality of non-continuous sides are formed, simultaneous heating of the plurality of heated parts is performed such that the plurality of heated parts are arranged side by side so as to be continuous or not continuous. In any case, the same can be applied.

[Brief description of drawings]

FIG. 1 is a plan view of the overall configuration showing a laser heating apparatus as a first embodiment of the present invention.

2 is a side view of the device of FIG. 1. FIG.

FIG. 3 is a circuit diagram showing a specific partial configuration of a current limiting circuit of the device shown in FIGS. 1 and 2.

4 is a circuit diagram showing a specific remaining configuration of a current limiting circuit of the device of FIGS. 1 and 2. FIG.

FIG. 5 shows L from the optical output-current / voltage characteristics of the semiconductor laser.
It is a graph which shows the current / voltage limit of D breakdown.

6A and 6B are a vertical cross-sectional side view and a horizontal cross-sectional view of the entire configuration showing a laser heating apparatus showing a second embodiment of the present invention.

7 is a vertical plan view of the apparatus of FIG. 6 and a perspective view of a semiconductor laser array and a heat radiator.

FIG. 8 is a side view and a plan view of a schematic configuration showing a laser heating tool showing a third embodiment of the present invention.

FIG. 9 is an overall configuration diagram showing a laser heating apparatus showing a fourth embodiment of the present invention.

10 is an overall configuration diagram including input / output relationships of a microcomputer of the apparatus of FIG.

FIG. 11 is an overall configuration diagram of a laser heating tool showing a fifth embodiment of the present invention.

FIG. 12 is a front view showing a part of a laser heating apparatus when a laser heating tool showing a sixth embodiment of the present invention is attached to an automatic working machine.

FIG. 13 is a perspective view showing a laser heating device when the laser heating tool according to the seventh embodiment of the present invention is mounted on a work arm of a robot for use.

FIG. 14 is a perspective view showing a laser heating tool showing an eighth embodiment of the present invention.

FIG. 15 is a perspective view showing a laser heating tool according to a ninth embodiment of the present invention.

FIG. 16 is a side view showing a conventional non-contact heating device using light, which uses a lamp light source.

[Explanation of symbols]

 1 Semiconductor Laser 2 Condensing Optical System 3 Laser Heating Tool 4 Driving Circuit 5 Current Limiting Circuit 17 Semiconductor Laser Array 18, 19 Cylindrical Lens 20 Convex Lens 21 Radiator 22 Cooling Fan 23 Tool Cover 29 Insulating Layer 32 Temperature Profile 33 Sequencer 34 Microcomputer 35 Sensor 41 Blower Means 43 Heating Means 51 Automatic Working Machine 52 Working Axis 53 Working Robot 54 Working Arm A Heated Parts B, B1 Irradiation Spot L Laser Light

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B23K 26/14 Z H01L 23/467 H01S 3/00 B H05K 3/34 507 E 8718-4E

Claims (21)

[Claims] 1. A semiconductor laser having an emission capacity required for heating is used to drive the semiconductor laser, and the laser light emitted from the semiconductor laser is directly transmitted through a condensing optical system to be condensed into a required shape. A laser heating method comprising converging and irradiating a heated portion and heating the heated portion with light. 2. A semiconductor laser having an emission capacity required for heating is driven under a predetermined current limit, and a laser beam emitted from the semiconductor laser is directly transmitted to a focusing optical system to have a required shape. A laser heating method, characterized in that by condensing light, the heated portion is focused and irradiated, and the heated portion is heated by light. 3. The laser heating method according to claim 2, wherein the semiconductor laser is driven under a condition corresponding to the temperature profile which is preset and stored for the laser light emitted from the semiconductor laser and is read out. . 4. The laser heating method according to claim 1, wherein a plurality of semiconductor lasers are used in combination. 5. The laser heating method according to claim 1, wherein when the semiconductor laser is driven, heat is radiated to the surroundings by a heat radiator that is in contact with the semiconductor laser. 6. A laser heating tool having a plurality of semiconductor lasers and one condensing optical system for directly transmitting laser light emitted from the semiconductor lasers and condensing it into a required shape, and converging irradiation of laser light. A sensor that detects the temperature of the part,
A laser heating apparatus comprising: a feedback control unit that controls a driving current of a semiconductor laser according to an output from the sensor. 7. A semiconductor laser provided with a radiator disposed around the semiconductor laser so as to be in contact with the semiconductor laser and having a cooling passage provided therein, and a cooling blower for blowing cooling air to the cooling passage of the radiator. Item 6. A laser heating device according to item 6. 8. The laser heating device according to claim 7, wherein the cooling path is a plurality of holes penetrating from the rear end to the front end of the radiator. 9. The laser heating device according to claim 7, wherein the cooling passage is formed straight. 10. The laser heating device according to claim 7, wherein the cooling passage is formed in a spiral shape. 11. The laser heating device according to claim 4, further comprising a blowing unit that blows air to the laser light focusing and irradiating unit. 12. The laser heating apparatus according to claim 11, wherein the air blowing means guides the exhaust air from the radiator by the cooling air blowing means. 13. The laser heating device according to claim 12, further comprising heating means for heating the exhaust gas from the radiator by the cooling air blowing means that guides the light to the light collecting portion. 14. A plurality of semiconductor lasers linearly arranged in a direction perpendicular to the emission direction, and a condensing optical system for directly transmitting laser light emitted from these semiconductor lasers and condensing the laser light at one point. A laser heating tool characterized by having. 15. The condensing optical system passes through a first cylindrical lens that condenses laser light emitted from a plurality of linearly arranged semiconductor lasers into parallel strip light, and the first cylindrical lens. 15. The laser heating tool according to claim 14, further comprising a second cylindrical lens for converging the band-shaped light in the width direction and a convex lens for converging the light passing through the second cylindrical lens at one point. 16. The laser heating tool according to claim 14, wherein the semiconductor lasers are arranged in a plurality of rows. 17. A semiconductor laser of a row arranged off the irradiation optical axis plane passing through the irradiation optical axis and parallel to the column direction of the semiconductor laser has a laser beam emitted from them on or near the irradiation optical axis plane. 17. The tilted arrangement is such that the tip end side is closer to the irradiation optical axis surface so that the light is incident along.
Laser heating tool as described in. 18. A radiator according to claim 14, further comprising: a heat radiator that is closely provided around the semiconductor laser and has a cooling hole therein, and a blowing unit that blows air to the cooling hole of the heat radiator. Laser heating tool. 19. The laser heating tool according to claim 14, wherein an insulating layer is provided between the tool cover and the radiator. 20. A plurality of semiconductor lasers appropriately arranged, and a condensing optical system for directly transmitting each laser beam emitted from each of the semiconductor lasers and condensing the laser light in an appropriate line shape. Characterized laser heating tool. 21. The laser heating tool according to claim 20, wherein the focusing is performed on a plurality of sides that are continuous or not continuous.