CN100563894C - metal heating method - Google Patents

Abstract

A metal heating device according to an embodiment of the present invention includes a light output unit that outputs light having a central wavelength within a wavelength range of 200nm to 600 nm.

Description

metal heating method

technical field

The invention relates to a metal heating device, a metal heating method, and a light source device.

Background technique

There are many kinds of devices for heating metal. For example, soldering is not only heated by a heater, but also heated by laser irradiation.

In the prior art, as described in Japanese Laid-Open Utility Model Publication No. 5-18751 or Masayuki Ikeda's "Laser Engineering", Ohm (オム) Company, pp.59-62, in order to irradiate the solder with laser light, For heating, laser light with wavelengths from the far infrared region to the long-wavelength visible region is used (for example, refer to Patent Document 1 and Non-Patent Document 1).

In addition, for example, when manufacturing electronic equipment, soldering is performed to electrically connect electronic components, wiring, and the like. Soldering is performed by melting solder on a metal member and then solidifying the melted solder. In Japanese Laid-Open Patent Publication No. 6-71425, Japanese Laid-Open Patent Publication No. 11-197868 and Japanese Laid-Open Patent Publication No. 2002-239717, it is disclosed that the solder can be melted by laser irradiation to perform soldering. Apparatus and methods. The soldering methods disclosed in these documents aim to increase the temperature rise rate of solder.

Contents of the invention

However, in conventional devices, it is difficult to efficiently heat an object.

Therefore, an object of the present invention is to provide a metal heating device, a metal heating method, and a light source device capable of efficiently heating an object.

A metal heating device according to one aspect of the present invention has a light output unit that outputs light having a center wavelength within a wavelength range of 200 nm to 600 nm.

In addition, the metal heating method according to another aspect of the present invention includes the steps of outputting light having a central wavelength within the wavelength range of 200 nm to 600 nm from the light output unit and irradiating the light to the metal member.

According to the present invention, the center wavelength of the light output from the light output unit is within the wavelength range of 200 nm to 600 nm. According to the present invention, since the center wavelength is within the above wavelength range, a metal member including gold (Au) is heated with good efficiency. In the present invention, it is also possible to output light whose central wavelength is within the wavelength range of 390 nm to 420 nm.

The metal heating device of the present invention also has a light guide unit, the light guide unit has an input end and an output end optically coupled with the light output unit, the light from the light output unit is input to the input end, and the light is guided, output from the outlet. In addition, the metal heating method of the present invention preferably further includes the step of inputting the light from the above-mentioned light output unit to the input end of the light guide unit, and guiding the light by the light guide unit, and from the light guide unit The exit end of the unit outputs. In this case, since the relative positions of the light output unit and the output end can be freely determined, the degree of freedom in device design increases.

Here, in the metal heating device of the present invention, the light output unit may include a light source that outputs light. In the metal heating device of the present invention, it is preferable that the light source is a laser light source. In this case, since the wavelength width of light is reduced, it is possible to efficiently irradiate a wavelength suitable for heating. In addition, it is preferable that the light source is a light source using a semiconductor element. In these cases, it is advantageous to improve the luminous efficiency, prolong the life of the light source, and reduce the size of the device. In addition, in the metal heating method of the present invention, it is preferable to output laser light as the above-mentioned light.

In the metal heating device of the present invention, an optical fiber is preferably included as the light guiding means. In addition, in the metal heating method of the present invention, it is preferable to guide the light by an optical fiber as the light guiding means. In this case, since the optical fiber is light and flexible, it is easy to change the light irradiation position, and the degree of freedom is high.

The metal heating device of the present invention may also further include a lens that expands, converges or collimates the light. The metal heating method of the present invention may further include a step of expanding, converging or parallelizing the light by a lens. In this case, the size (diameter) or optical power density of the irradiation light can be adjusted to a desired level.

In addition, in the metal heating device of the present invention, the light output unit may include a plurality of light sources that output light. Preferably, the plurality of light sources are respectively laser light sources. The light source is preferably a light source using a semiconductor element. In this case, since the power of the light output from the light guide unit is large, it is possible to expand the light irradiation area or increase the light power density. In addition, since the drive current supplied to each light source can be reduced, the frequency of failure of each semiconductor laser light source can be reduced. In addition, when an individual light source fails, output control is performed to increase the output of other light sources that have not failed, and to compensate for the output drop caused by the failed light source, which can reduce the frequency of device failure. In addition, in the metal heating method of the present invention, it is preferable to output light from a plurality of light sources, and in this case, the light is preferably laser light.

The plurality of light sources may include a first light source that outputs light at the first center wavelength and a second light source that outputs light at the second center wavelength. In this case, efficient heating can be performed by setting the center wavelength of each light source to a wavelength suitable for heating each metal to be irradiated.

In the metal heating device of the present invention, it is preferable that the light guide unit includes a plurality of optical fibers arranged one-to-one with respect to the plurality of light sources, and each optical fiber guides light output from a corresponding light source among the plurality of light sources. In the metal heating method of the present invention, it is preferable that the light output from the corresponding light source among the plurality of light sources is guided by a plurality of optical fibers serving as light guiding means arranged 1 to 1 with respect to the plurality of light sources. In this case, the light output from each light source is guided by the corresponding optical fiber, and is irradiated to the metal member. Also, in this case, since light from light sources having different intensities or different center wavelengths can be irradiated separately without mixing them, objects having different materials or shapes can be efficiently heated two-dimensionally.

The metal heating device of the present invention may further include a plurality of lenses arranged 1 to 1 with respect to the plurality of light sources. In addition, the metal heating method of the present invention may further include a step of converging or parallelizing the light with a plurality of lenses provided 1 to 1 with respect to the plurality of light sources.

Preferably, the metal heating device of the present invention further includes a control unit for controlling the output operation of each of the plurality of light sources. In addition, the metal heating method of the present invention may further include the step of controlling the output operation of each of the plurality of light sources by the control unit. In this case, the output operation of each of the plurality of light sources is individually controlled by the control unit, the light is guided by the optical fiber corresponding to each light source, and the power of light irradiated to the metal member can be individually controlled.

In addition, in the metal heating device of the present invention, it is preferable that the output ends of the plurality of optical fibers are arranged one-dimensionally or two-dimensionally. In this case, the range of light irradiation can be widened, and the range of light irradiation can be changed by controlling the output operation of each light source by the control unit.

The metal heating device of the present invention preferably further has a mounting unit arranged along the plane where light from each of the output ends of the plurality of optical fibers intersects, and a photographing unit for photographing an image of an area on the mounting unit, for The image guide unit moves the mounting unit or the output end, and the control unit controls the output operation of each of the plurality of light sources. In addition, the metal heating method of the present invention preferably further includes the step of mounting the metal member on the mounting unit, and the step of photographing the image of the metal member by the photographing unit, and measuring the position of the metal member or the emitting end based on the image photographed by the photographing unit. The step of adjusting, and the step of controlling the output operation of each of the plurality of light sources by the control unit. According to the present invention, by mounting the metal member on the mounting unit, it is possible to adjust the light irradiation position with respect to the metal member with high precision.

A light source device according to still another aspect of the present invention includes a plurality of light sources, a plurality of optical fibers arranged one-to-one with respect to the plurality of light sources, and a control unit for individually controlling output operations of the plurality of light sources. According to this light source, it is possible to irradiate the object with light of various patterns.

In the metal heating device of the present invention, it is preferable to control the output operations of the plurality of light sources so that the intensity of the light irradiated on the second area surrounding a part of the first area on the mounting unit is higher than that of the light irradiated on the first area. The intensity of the light is high. In addition, the metal heating device of the present invention may be a device for heating solder. In this case, only the solder connection portion can be heated, and parts other than the soldered portion are not heated in the solder reflow process, so the yield and reliability of soldered parts can be improved.

In the metal heating method of the present invention, it is preferable to control the output operations of the above-mentioned plurality of light sources so that the intensity of light irradiated on the second area surrounding a part of the first area on the above-mentioned mounting unit is higher than that on the first area. The intensity of the light is large. In addition, the metal heating method of the present invention may be a method of heating solder by irradiating a metal member with light. In addition, the metal heating method of the present invention preferably further includes the step of supplying tin-containing solder onto the metal member, the metal member including gold, and in the step of adjusting the position of the metal member, adjusting the position of the solder to the first region, Adjust the position of the metal member to the 2nd area. In addition, in the light source device of the present invention, it is preferable that the control unit controls the output operations of the plurality of light sources so that the intensity of light irradiated on the second area surrounding a part of the first area on the mounting unit is higher than that irradiated on the first area. The intensity of the light of the area is large.

According to the present invention, for example, when soldering the wiring pattern of the substrate and the terminals of the IC, the solder is located in the first area and the wiring pattern is located in the second area, so that the solder can be melted by the heat of the wiring pattern. , can improve the pass rate and reliability of soldering.

The metal heating device of the present invention preferably further includes an optical fiber having an input end optically coupled to each output end of the plurality of optical fibers and an output end for outputting light input to the input end. In this case, The power of the laser beam irradiated on the solder can be increased.

The metal heating method of the present invention includes (1) the step of supplying the second metal member onto the first metal member, and (2) irradiating light to both the first metal member and the second metal member or only to the first metal member. Component steps. The light is preferably laser light.

In the metal heating method of the present invention, it is preferable that (3a) in the step of irradiating light, irradiate light with a center wavelength at which the reflectance of the second metal member is higher than that of the first metal member. According to the metal heating method of the present invention, the rate of temperature rise of the first metal member can be made greater than the rate of temperature rise of the second metal member. In addition, the temperature rise at each position of the first metal member or the second metal member can be controlled.

In the metal heating method of the present invention, the second metal member may be solder. It is also possible to make the first metal member mainly composed of gold and the second metal member mainly contain tin. In this case, it is preferable that the central wavelength of light is 550 nm or less. In this case, the soldering compatibility between the metal member and the solder is good. In addition, since the temperature of the first metal member can be increased first, the solder can be melted from the portion in contact with the first metal member. Therefore, soldering with high yield and reliability can be performed. Here, using a certain object as a "principal component" means that the object "contains in the largest proportion". Therefore, the case where the ratio is 50% or less is also included.

In the metal heating method of the present invention, (3b) it is preferable to irradiate light so that the light irradiation area of the first metal member is larger than the light irradiation area of the second metal member. In addition, only the first metal member may be irradiated with light. In addition, at this time, it is preferable that the first metal member contains gold as a main component, and the central wavelength of light is less than 600 nm. In addition, it is preferable that the second metal member is solder mainly composed of tin. In this case, the temperature rise rate of the first metal member can be made faster than the temperature rise rate of the second metal member. In addition, when the second metal member is solder, it is preferable to melt the portion of the solder that is in contact with the first metal member first.

In the metal heating method of the present invention, (3c) it is preferable to irradiate light so that the amount of energy applied to the first metal member is greater than the amount of energy applied to the second metal member. In addition, the second metal member is preferably solder, the first metal member is preferably composed of gold, and the second metal member is mainly composed of tin. In this case, the temperature rise rate of the first metal member can be made faster than the temperature rise rate of the second metal member. In addition, when the second metal member is solder, it is preferable to melt the portion of the solder that is in contact with the first metal member first.

In the metal heating method of the present invention, it is preferable that (3d) the light of the first central wavelength and the light of the second central wavelength are irradiated as laser light. In this case, the temperature rise rate of the first metal member can be made faster than the temperature rise rate of the second metal member.

In the metal heating method of the present invention, it is preferable that the emission positions of the light of the first central wavelength and the light of the second central wavelength are the same. In addition, at this time, the light of the first central wavelength and the light of the second central wavelength are light-guided by the shared optical fiber, so that the light of the first central wavelength and the light of the second central wavelength are respectively emitted from the end faces of the optical fiber and irradiated to the second central wavelength. 1 metal member or 2nd metal member. In this case, an optical system for guiding or irradiating laser light to the first metal member or the second metal member can be configured simply and inexpensively.

In the metal heating method of the present invention, it is preferable to make the light irradiation area of the first metal member larger than the light irradiation area of the second metal member to irradiate the light of the first central wavelength, and at the same time, make the light irradiation area of the second metal member larger than the light irradiation area of the second metal member. The light irradiation area of the first metal member is largely irradiated with the light of the second center wavelength. In addition, at this time, the light of the first central wavelength and the light of the second central wavelength are guided by the bundled optical fiber, so that the light of the first central wavelength and the light of the second central wavelength are separated from the bundled optical fiber. The output position emits light to irradiate the first metal member or the second metal member. In this case, for the temperature rise of the first metal member, the irradiation of light with the first center wavelength is dominant, and for the temperature rise of the second metal member, the irradiation of light with the second center wavelength is dominant. Therefore, by adjusting Optimum heating can be performed by any one of the respective wavelengths, irradiation intensity, and irradiation range of the light of the first center wavelength and the light of the second center wavelength. In addition, when a bundled optical fiber is used, an optical system for guiding or irradiating light to the first metal member or the second metal member can be configured simply and inexpensively.

In the metal heating method of the present invention, it is preferable that the respective center wavelengths of the light having the first center wavelength and the light having the second center wavelength differ from each other by more than a wavelength width. Alternatively, it is preferable that the respective center wavelengths of the light having the first center wavelength and the light having the second center wavelength differ from each other by 100 nm or more. Efficient heating can be performed by using the light of the first center wavelength and the light of the second center wavelength having different center wavelengths while appropriately setting various conditions when irradiating the first metal member or the second metal member.

In the metal heating method of the present invention, it is preferable that the first metal member contains gold as a main component, and the first center wavelength is less than 600 nm. In addition, it is preferable that the second metal member mainly contains tin, and the second center wavelength is 600 nm or more. In addition, it is preferable that the second metal member is solder. In this case, the solder compatibility between the first metal member and the solder as the second metal member is good. When the central wavelength is less than 600 nm, the reflectance of gold is small, so by irradiating the first metal member mainly composed of gold with light having a central wavelength of less than 600 mm, the first metal member can be efficiently heated. In addition, as a light source that outputs light with a central wavelength of 600nm or more, a relatively inexpensive and high-power light source can be obtained. On the other hand, since the wavelength dependence of the reflectance of tin is small, it is best to use tin as the main component. The second metal member is irradiated with light having a center wavelength of 600 nm or greater.

Description of drawings

Fig. 1 is a configuration diagram of a metal heating device according to a first embodiment.

Fig. 2 is a diagram illustrating the arrangement of output ends of M×N optical fibers included in the metal heating device according to the first embodiment.

Fig. 3 is a configuration diagram of a metal heating device according to a second embodiment.

FIG. 4 is a graph showing the wavelength dependence of the absorbance of gold, silver, and copper.

FIG. 5 is a graph showing the wavelength dependence of the absorbance of tin.

Fig. 6 is an explanatory diagram of a metal heating method according to a third embodiment.

Fig. 7 is an explanatory diagram of a modified example of the metal heating method of the third embodiment.

Fig. 8 is an explanatory diagram of a metal heating method according to a fourth embodiment.

Fig. 9 is a diagram showing an example of the configuration of a soldering device preferably used in the metal heating method of the fourth embodiment.

Fig. 10 is a diagram showing another example of the configuration of a metal heating device preferably used in the metal heating method of the fourth embodiment.

Fig. 11 is a perspective view schematically showing a metal heating device according to a fifth embodiment.

Fig. 12 is an example of a screen displayed on a monitor board.

Fig. 13 is an enlarged view showing a soldered portion.

Fig. 14 is a diagram illustrating another arrangement of output ends of optical fibers.

Fig. 15 is a diagram illustrating another arrangement of output ends of optical fibers.

Fig. 16 is a diagram showing another example of the configuration of a metal heating device preferably used in the metal heating method of the fourth embodiment.

Fig. 17 is a diagram showing another example of the configuration of a metal heating device preferably used in the metal heating method of the fourth embodiment.

Fig. 18 is a diagram showing another example of the configuration of a metal heating device preferably used in the metal heating method of the fourth embodiment.

Fig. 19 is a diagram showing another example of the configuration of a metal heating device preferably used in the metal heating method of the fourth embodiment.

Detailed ways

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same symbols are used for the same parts, and repeated descriptions are omitted.

(first embodiment)

First, a first embodiment of the metal heating device of the present invention will be described. Fig. 1 is a configuration diagram of a metal heating device according to a first embodiment. The metal heating device 1 shown in this figure has a light output unit 10 , M×N lenses 20 _1,1 to 20 _M,N , a light guide unit (light guide unit) 30 , a fixing member 40 , and a control unit 50 . Wherein, M and N are integers greater than or equal to 2. In addition, m used below represents any integer greater than or equal to 1 and less than or equal to M, and n represents any integer of greater than or equal to 1 and less than or equal to N.

The light output unit 10 has M×N light sources 10 _1,1 to 10 _M,N . Each light source 10 _{m, n} preferably outputs light with a center wavelength within the wavelength range of 200 nm to 600 nm. More preferably, the light is laser light. Here, the central wavelength is the wavelength at the center of the wavelength width, and the wavelength width is the half-value (half-value width).

The light source 10 _{m, n} may be a light source using a semiconductor element. For example, as the light source 10 _{m, n} , a laser diode (LD), a light emitting diode (LED), an LD pumped solid-state laser, or the like can be used. If the center wavelength is 550 nm or less, various light emitting diodes can be used, so high luminous efficiency, long life, and device miniaturization can be realized. If the center wavelength is 390nm or more and 420nm or less, a mass-produced laser diode with a center wavelength of 400nm, which is used as a high-density recording digital laser video disc light source, can be used to achieve high power density at the output end at low cost. In addition, if the central wavelength is 370nm or more, the irradiation status such as the position of the light and the beam diameter can be easily confirmed visually or by a general-purpose visible light camera.

As the laser diode, a blue-violet laser diode with a center wavelength of 400 nm is exemplified. Examples of light emitting diodes include GaN LEDs with a center wavelength of 430 nm, InGaN LEDs with a center wavelength of 500 nm, and GaP LEDs with a center wavelength of 550 nm. Examples of the LD-pumped solid-state laser include a Nd-YAG triple-wave laser with a center wavelength of 355 nm, a Nd-YAG double-wave laser with a center wavelength of 532 nm, and the like. Examples of other light sources include a He-Cd gas laser with a center wavelength of 442 nm, an Ar gas laser with a center wavelength of 488 nm or 515 nm, a KrF excimer laser with a center wavelength of 248 nm, and a XeCl excimer laser with a center wavelength of 308 nm.

In the case of using a laser diode as a light source 10 _{m, n} , a compact metal heating device with high power and a simple cooling unit is provided. When a light emitting diode is used, a metal heating device capable of more efficient light emission, low running cost, and low device cost is provided. In the case of using LD to excite solid-state lasers, a very high-power metal heating device is provided.

In addition, as the light source 10 _m,n , a fiber-type light source combining an excitation photodiode and an optical fiber such as a fiber laser or an ASE light source may be used. In this case, the connection to the optical fiber used as the light guide part 30 becomes easy.

The light guide unit 30 has M×N optical fibers 30 _1,1 to 30 _M,N . Each lens 20 _{m, n} condenses the light output from the corresponding light source 10 _{m, n} , and makes the light incident on the incident end of the corresponding optical fiber 30 _{m, n} . Each optical fiber 30 _{m, n} guides the light output from the corresponding light source 10 _{m, n} , and the light collected by the corresponding lens 20 _{m, n} is input to the incident end, and the light is guided to the output end output. It is preferable to install a condensing optical system such as a lens for collimating or converging the outgoing light at the outgoing end of each optical fiber 30 _{m, n} .

The fixing member 40 is used to fix the arrangement of the output ends of the M×N optical fibers 30 _1,1 to 30 _M,N . The output ends of the M×N optical fibers 30 _1,1 to 30 _M,N are two-dimensionally arranged by the fixing member 40 . FIG. 2 is a diagram illustrating the arrangement of output ends of M×N optical fibers 30 _1,1 to 30 _M,N included in the metal heating device according to the first embodiment. As shown in the figure, in the two-dimensional array, each optical fiber 30 _{m, n} is located in the mth row and the nth column. The plurality of optical fibers 30 may be arranged circularly as shown in FIG. 14 , or may be arranged polygonally like the hexagonal arrangement shown in FIG. 15 .

The control unit 50 controls the output operation of each of the M×N light sources 10 _1,1 to 10 _M,N, respectively. For example, the control unit 50 can control the magnitude of the drive current supplied to each light source 10 _{m, n} or the supply time of the drive current, and can also control the degree of optical coupling to the optical fiber 30 _{m, n} using a modulator.

This metal heating device 1 operates as follows. When light is output from all or any one of the M×N light sources 10 _{1, 1} to 10 _{M, N} , the light output from each light source 10 _{m, n} is condensed by the lens 20 _{m, n} , and is incident on the optical fiber 30 _m, The incident end of _n is guided by the optical fiber 30 _{m, n} , and is output from the output end of the optical fiber 30 _{m, n} to the outside.

The light output from the output end of each optical fiber 30 _{m, n} is output from each light source 10 _{m, n} , and enters the input end of the optical fiber 30 _{m, n} . Therefore, the output operation of each of the M×N light sources 10 _1,1 to 10 _M,N is controlled by the control unit 50, and the power of the light output from the output end of each optical fiber 30 _m,n is adjusted. Then, the metal member is heated by irradiating the output light to the metal member.

In this embodiment, since the power of the light output from the output end of each optical fiber 30 _{m, n} can be adjusted respectively, the light can be selectively irradiated to the position to be heated, and unnecessary unnecessary heating of the light at other positions can be suppressed. light exposure. In addition, since there is a large degree of freedom in changing the light irradiation position, it is possible to continuously heat a plurality of components corresponding to different heating positions.

In addition, in this embodiment, by setting the central wavelength of the light irradiated on the metal member within the wavelength range of 200 nm to 600 nm, good heating efficiency for the metal member containing gold is obtained. FIG. 4 is a graph showing the wavelength dependence of the absorbance of gold, silver, and copper. Among them, the absorbance has approximately the same relationship as 1-reflectance.

As in the prior art, when using infrared laser (center wavelength 800nm～1100nm) to heat the metal member containing gold, because the reflectivity of gold of infrared laser is higher as shown in Figure 4, so the gold-containing The heating efficiency of metal components is low. Therefore, gold-containing metal components cannot be heated with good efficiency by infrared laser light.

On the other hand, the metal heating device 1 according to the first embodiment irradiates a metal member containing gold with light having a central wavelength of 200 nm to 600 nm, which has a low reflectance of gold, so that the metal member can be heated efficiently. That is, at a central wavelength of 800 nm to 1100 nm, the absorbance of gold is as low as 3% or less. On the other hand, when the central wavelength is 600 nm or less, the absorbance of gold exceeds 10% (3 times), so efficient heating can be performed. In addition, when the central wavelength is 480nm or less, the absorbance of gold is 60%, which is the highest level in the visible light region, enabling more efficient heating.

In addition, when the metal heating device 1 is used for soldering with tin-containing solder on a gold-containing metal member, the yield and reliability of soldering can be improved. FIG. 5 is a graph showing the wavelength dependence of the absorbance of tin. As shown in FIGS. 4 and 5 , tin or a tin-containing metal has a lower light absorbance at a central wavelength of 200 nm to 600 nm than gold. That is, when irradiated with light of the above-mentioned wavelength, the temperature rise rate of gold is faster than that of tin. Therefore, when the light of the above-mentioned wavelength is irradiated to the metal member supplied with solder, the metal member is heated first, and the portion of the solder that is in contact with the metal member is first melted. As a result, the yield and reliability of soldering are improved. Specifically, when the central wavelength is 550 nm or less, the absorbance of gold is higher than that of tin (25%), and the temperature rise rate of gold is higher than that of tin. Therefore, reliable soldering becomes possible.

In addition, as shown in FIG. 5, when the center wavelength is 800 nm or more, the light absorbance of silver (Ag) is as low as 3% or less. On the other hand, when the center wavelength is 420 nm or less, more than 10% (3 times), highly efficient heating of silver becomes possible.

In addition, as shown in FIG. 5 , when the center wavelength is 800 nm or more, the light absorbance of copper (Cu) is as low as 5% or less. On the other hand, when the center wavelength is 600nm or less, more than 15% (3 times), efficient heating of copper becomes possible. In addition, when the central wavelength is 500nm or less, the absorbance is 40% or more, which is the highest level in the visible light region, enabling more efficient heating.

(Second Embodiment)

Next, a second embodiment of the present invention will be described. Fig. 3 is a configuration diagram of a metal heating device according to a second embodiment. The metal heating device 2 shown in this figure has a light output unit 10 , K lenses 20 ₁ to 20 _K , a light guide unit (light guide unit) 30 , and a control unit 50 . Wherein, K is an integer greater than or equal to 2. In addition, k used hereafter represents an arbitrary integer of 1 or more and K or less.

The light output unit 10 has K light sources 10 ₁ to 10 _K . Each light source _10k preferably outputs light with each center wavelength within the wavelength range of 200nm to 600nm. The light is preferably laser light. For each light source _10k, the same light source as the above-mentioned light sources _{10m, n} can be used.

The light guide unit 30 has K optical fibers 30 ₁ to 30 _K and one optical fiber 31 . Each lens _20k condenses the light output from the corresponding light source _10k , and makes the light incident on the incident end of the corresponding optical fiber _30k . Each optical fiber _30k guides the light output from the corresponding light source _10k , inputs the light condensed by the corresponding lens _20k to the incident end, guides the light, and outputs it from the output end.

The incident end of the optical fiber 31 is optically coupled to the output end of each of the K optical fibers 30 ₁ to _30K . The optical fiber 31 inputs the light emitted from each output end of the K optical fibers 30 ₁ to 30 _K to its own input end, further guides the light, and outputs it from the output end. At the output end of the optical fiber 31, it is preferable to provide a condensing optical system such as a lens for collimating or converging the emitted light.

The control unit 50 controls each output operation of the K light sources 10 ₁ to 10 _K , respectively. For example, the control unit 50 may control the magnitude of the drive current supplied to each light source _10k , or may use a modulator to control the degree of optical coupling to the optical fiber _30k .

This metal heating device 2 operates as follows. When all or any one of the K semiconductor laser light sources 10 ₁ to 10 _K outputs light, the light output from each light source 10 _k is condensed by the lens 20 _k , input to the incident end of the optical fiber 30 _k , and transmitted by the optical fiber 30 _k The light is guided, further guided by the optical fiber 31 , and output to the outside from the output end of the optical fiber 31 .

The light output from the output end of the optical fiber 31 is light obtained by combining the light output from the respective optical fibers _10k and input to the input end of the optical fiber _30k . Therefore, by controlling the output operation of each of the K light sources 10 ₁ to 10 _K by the control unit 50 , the power of the light output from the output end of the optical fiber 31 is adjusted. By irradiating the output light to the metal member, the metal member is heated.

In this embodiment, the power of the light output from the output end of the optical fiber 31 can be appropriately adjusted, so that only the light of the power required for heating the metal member is irradiated to the solder, and unnecessary heating of other parts can be reduced. In addition, since the drive current of each light source can be reduced, the frequency of failure of the light source can be reduced.

In addition, this metal heating device 2 can heat a gold-containing member with good efficiency similarly to the metal heating device 1 . In addition, when the metal heating device 2 is used for soldering gold-containing metal members with gold-containing solder similarly to the metal heating device 1, the soldering yield and reliability can be improved.

(third embodiment)

Next, a third embodiment of the present invention will be described. Fig. 6 is an explanatory diagram of a metal heating method according to a third embodiment. In the metal heating method of the third embodiment, solder (second metal member) 112 is supplied to metal member (first metal member) 111 , and solder 112 is melted on metal member 111 for soldering. In this metal heating method, laser light L is irradiated to both the metal member 111 and the solder 112 or only to the metal member 111 . By irradiating the laser light L in this way, the portion of the solder 112 placed on the metal member 111 that faces the metal member 111 , that is, the portion of the solder 112 that is in contact with the metal member 111 is first melted. In this way, the portion of the solder 112 placed on the metal member 111 that is opposed to the metal member is melted earlier than the portion on the opposite side to the opposite portion, thereby increasing the yield or reliability of soldering.

In this metal heating method, it is preferable to irradiate laser light L having a wavelength whose reflectance of the solder 112 is higher than that of the metal member 111 . In addition, as shown in Figure 4 and Figure 5, the wavelength dependence of the respective absorbance of gold and tin, when the wavelength is 550nm or less, the absorbance of gold is larger than the absorbance of tin, so it is best to use metal The member 111 is mainly composed of gold, the solder 112 is mainly composed of tin, and the center wavelength of the laser light L is preferably 550 nm or less. In this case, the rate of temperature rise of the metal member 111 is set to be greater than the temperature rise rate of the solder 112 , so that the portion of the solder 112 facing the metal member 111 is suitably melted first. In addition, in this case, it is preferable that the soldering compatibility between the metal member 111 and the solder 112 is good. In recent years, in consideration of the environment, solder (Sn-3Ag-0.5Cu) mainly composed of tin has been used instead of solder containing lead.

In addition, it is preferable to irradiate the laser beam L so that the laser irradiation area of the metal member 111 is larger than the laser irradiation area of the solder 112 . As shown in FIG. 7 , the laser light L may be irradiated only to the metal member 111 . At this time, as shown in FIG. 4 and FIG. 5 , when the wavelength is less than 600 nm, the light absorption rate of gold is large, so it is preferable that the metal member 111 mainly contains gold, and the center wavelength of the laser light L is less than 600 nm. In this case, it is preferable to increase the temperature rise rate of the metal member 111 faster than that of the solder 112 so that the portion of the solder 112 facing the metal member 111 is melted first.

In addition, it is preferable to irradiate the laser light L so that the amount of energy applied to the metal member 111 is greater than the amount of energy applied to the solder 112 . Here, the amount of energy imparted is represented by the product of irradiation energy and light absorbance. In order to adjust the amount of energy imparted to the metal member 111 and the solder 112 , any one of the laser reflectance (namely, the wavelength of the laser L), the laser irradiation intensity, and the laser irradiation range may be adjusted. In this case, the rate of temperature rise of the metal member 111 is set to be greater than that of the solder 112 , so that the portion of the solder 112 facing the metal member 111 is suitably melted first.

(fourth embodiment)

Next, a fourth embodiment of the present invention will be described. Fig. 8 is an explanatory diagram of a metal heating method according to a fourth embodiment. In the metal heating method of the fourth embodiment, the solder (second metal member) 112 is supplied to the metal member (first metal member) 111, and the solder 112 is melted on the metal member 111 for soldering; Or the solder 112 is irradiated with the laser light L1, L2. By irradiating the laser beams L1 and L2 in this way, the portion of the solder 112 placed on the metal member 111 that faces the metal member 111 , that is, the portion of the solder 112 that is in contact with the metal member 111 is first melted. In this way, the portion of the solder 112 placed on the metal member 111 that is opposed to the metal member 111 is melted earlier than the portion on the opposite side to the opposite portion, thereby increasing the yield and reliability of soldering.

The metal heating method of this fourth embodiment is characterized in that laser light L1 with a first center wavelength and laser light L2 with a second center wavelength are used as laser light irradiated to the metal member 111 or the metal heater 112 .

Fig. 9 is a diagram showing an example of the configuration of a metal heating device preferably used in the metal heating method of the fourth embodiment. In the metal heating device 4 shown in this figure, the laser light L1, L2 is output from the light output part 10, passes through the coupling optical system (lens) 20, enters one end of the light guide part (optical fiber) 30, and is guided by the light guide part 30. After that, it exits from the other end of the light guide part 30 , is condensed or collimated by the lens 120 , and irradiates the metal member 111 or the solder 112 . In this way, it is preferable that the emission positions of the laser beams L1 and L2 are the same. In this way, an optical system for guiding or irradiating the laser beams L1 and L2 to the metal member 11 or the solder 12 can be configured simply and inexpensively.

Fig. 10 is a diagram showing another example of the configuration of a metal heating device preferably used in the metal heating method of the fourth embodiment. The metal heating device 4 a shown in this figure has the same configuration as the metal heating device 1 shown in FIG. 1 except that it has a lens 120 . In this metal heating device 4a, the light output unit 10 has a plurality of light sources _10k , some of the plurality of light sources _10k output the laser light L1 of the first center wavelength, and the other part output the laser light L2 of the second center wavelength. k is an integer greater than or equal to 1, and in FIG. 10 , k shows an example of 1 and 2 cases.

One laser beam L1 is output from the light source 10 ₁ of the light output unit 10 , passes through the coupling optical system (lens) 20 ₁ , and enters one end of the bundled optical fiber serving as the light guide unit 30 . The other laser light L2 is output from the light source 10 ₂ , passes through a coupling optical system (lens) 20 ₂ , and is input to one end of a bundled optical fiber serving as the light guide 30 . The laser light L1 and L2 incident on one end of the bundled fiber 30 is guided by the bundled fiber 30 , exits from the other end of the bundled fiber 30 , is condensed or collimated by the lens 120 , and irradiates the metal member 111 or the solder 112 .

By using the bundled optical fiber 30 as shown in FIG. 10 , the laser beams L1 and L2 are respectively emitted from different emission positions of the bundled optical fiber 30 to easily irradiate the metal member 111 or the solder 112 . In addition, the metal member 111 is irradiated with the laser beam L1 to a larger laser irradiation area than the solder 112 , and the laser beam L2 is irradiated to a larger laser irradiation area of the solder 112 than the metal member 111 . In this way, for the temperature rise of the metal member 111, the irradiation of the laser light L1 is dominant, and for the rise of the temperature of the solder 112, the irradiation of the laser light L2 is dominant. Therefore, by adjusting the respective wavelengths, irradiation intensities and irradiation range, etc., so that the best soldering can be performed. In addition, by using the bundled optical fiber 30 , an optical system for guiding or irradiating the laser beams L1 and L2 to the metal member 111 or the solder 112 can be formed simply and inexpensively.

It is preferable that the center wavelengths of the laser light L1 and L2 differ by more than a wavelength width, or by 100 nm or more. By using the laser beams L1 and L2 having different center wavelengths in this way, and setting various conditions for irradiating the metal member 111 or the solder 112 appropriately, efficient soldering can be performed.

In addition, it is preferable that the metal member 111 mainly contains gold, and the center wavelength of the laser light L1 is less than 600 nm. In addition, it is preferable that the solder 112 is mainly composed of tin, and the center wavelength of the laser light L2 is 600nm or above. In this way, the soldering compatibility between the metal member 111 and the solder 112 is good. As shown in Figure 4 and Figure 5, when the wavelength is less than 600nm, the reflectance of gold is small, so the metal member 111 mainly composed of gold is irradiated with laser light L1 with a center wavelength of less than 600mm, so that it can be carried out efficiently. Heating of metal member 111 . In addition, as the light source _10k of the laser light L2 outputting a central wavelength of 600nm or above, a relatively cheap and high-power light source (such as a semiconductor laser light source with an output wavelength of 800nm, a YAG laser light source with an output wavelength of 1064nm, etc.), as shown in Figure 4 As shown in FIG. 5 , since the wavelength dependence of the reflectance of tin is small, it is preferable to irradiate the laser light L2 with a center wavelength of 600 nm or more on the solder 112 mainly composed of tin.

When the laser light from the light source 10 _k is sufficiently guided to the optical fiber 30 , the lens 20 _k may not be provided as shown in FIG. 16 . Alternatively, as shown in FIG. 17 , a single lens 20 may guide the laser light from the light source 10 _k to the optical fiber 30 . In addition, as shown in FIG. 18 , the laser light may be condensed by the lens 120 and irradiated without using an optical fiber. In addition, as shown in FIG. 19, light may be irradiated directly from the light source _10k .

(the fifth embodiment)

Next, a fifth embodiment of the present invention will be described. Fig. 11 is a perspective view schematically showing a metal heating device according to a fifth embodiment. The metal heating device 5 shown in the figure uses the above-mentioned metal heating device 1 , 2 , 4 or 4 a as the light source device 60 . The light source device 60 has a module 62 in which the light output unit 10 and the control unit 50 are incorporated, and the light guide unit 30 is connected to the module 62 .

In addition, the metal heating device 5 has a base 64, a first table (mounting unit) 66, guides (guide units) 68a and 68b, a support 70, a second table 72, a solder supply unit 74, a camera (photographing unit) 76, and Monitor 78.

The base 64 supports the first table 66 via guides 68a and 68b. The first stage 66 is provided along a surface where the light from the output end 30 a of the light guide 30 intersects. The first stage 66 is movable by guides 68a and 68b in two directions intersecting the optical axis of the above-mentioned light. A driving system such as a stepping motor for moving the first table 66 may also be provided.

The pillar 70 is supported by the base 64 and extends in the same direction as the above-mentioned optical axis. The second table 72 is supported by the pillar 70 and is movable along the pillar 70 . A drive system such as an air cylinder for moving the second unit 72 may be provided.

The solder supply device 74 supplies solder to the metal member mounted on the first table 66, and can supply the solder wire wound on the reel to the metal member.

The camera 76 takes an image of the area on the first station 66 and outputs the image to the monitor 78 . Therefore, the image of the metal member mounted on the first table 66 is displayed on the monitor 78 .

In addition, the metal heating device 5 may have a temperature sensor 80 for measuring the temperature of an area on the first table 66 . In this case, the output from the temperature sensor 80 is supplied to the control unit 50 to control the light output from the light output unit 10 . The temperature sensor 80 is preferably a device that measures a two-dimensional temperature distribution like an infrared CCD camera. In this case, by individually adjusting the light outputs of the plurality of light sources by the control unit 50 based on the measurement results of the temperature distribution, heating can be performed with the target optimum temperature distribution.

Next, the operation of the metal heating device 5 having the metal heating device 1 as the light source device 60 will be described as an example. Here, an example is described in which an IC chip is mounted as a metal member on a substrate provided with a pattern containing gold, and terminals of the pattern and the IC chip are soldered with solder containing tin.

Fig. 12 is an example of a screen displayed on a monitor board. When this metal heating device 5 is used, first, the substrate 90 is mounted on the first stage 66 . Based on the image of the substrate 90 captured by the camera 76 , the first stage 66 is moved. For example, as shown in FIG. 12, when two IC chips 92 are mounted on the substrate 90, the first stage 66 is moved to irradiate light from the output terminal 30a to one of the regions 98a and 98b where the chips 92 are mounted. This movement locates the solder described later in the first area of the area irradiated with light from the output terminal 30a, and positions the pattern 90a of the substrate 90 in the second area. This movement may be performed by controlling the drive train of the first stage 66 based on the result of image processing, or may be performed manually.

Then, the IC chip 92 is mounted on the substrate 90 . Solder 96 is supplied from the solder supply device 74 onto the pattern 90 a of the substrate 90 and the terminal 92 a of the IC chip 92 .

Then, light is output from the light output unit 10 by the drive current from the control unit 50 . FIG. 13 is an enlarged view showing a soldered portion. In FIG. 13 , circular marks marked with dotted lines indicate light spots projected from the respective optical fibers 30 _{m, n} onto the substrate 90 .

Here, the control unit 50 makes the driving current of the light sources 10 _{m, n} outputting light for irradiating the second area larger than the driving current of the light sources 10 _{m, n} outputting light for irradiating the first area. The light source 10 _m,n that outputs light for irradiating other areas receives a smaller driving current, or supplies no driving current. This first area is the area of the irradiated light spot hatched with oblique lines in FIG. 13 , and is the area where the solder 96 should be located. In addition, the second area is the area where the dots hatched in a grid pattern are irradiated in FIG. 13, and is the area where the pattern 90a should be located. In this way, the intensity of light irradiated on the pattern 90a can be increased, and the temperature of the pattern 90a can be raised earlier than that of the solder 96 . As a result, the solder 96 at the portion in contact with the pattern 90a melts first, and highly reliable soldering can be realized. In addition, the second region surrounds a part of the first region, and does not irradiate the IC chip 92 with high-intensity light. Therefore, failure of IC92 can be prevented.

After the solder 96 is melted, the current supply to the light source 10 _m,n is stopped, and the solder hardens. At this time, the hardening time can also be shortened by forcibly cooling the substrate 90 .

Then, the light from the output terminal 30a is irradiated to the other of the area 98a or 98b to move the first stage 66, and then the above-mentioned processing is repeated.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various modifications are possible. For example, since the present invention can efficiently heat metal members, it is also applicable to annealing of metals, strain relief of metals, deformation of metals, and the like. In addition, it is also applicable to sintering processing of metal fine particles.

In addition, the number of light sources may be plural or may be one. In the first embodiment, the output ends of the plurality of optical fibers are arranged two-dimensionally, but the output ends of the plurality of optical fibers may be arranged one-dimensionally.

In addition, the metal heating devices 1, 3, 4, and 4a can also be used as light source devices. In the case where the metal heating devices 1 and 4a are used as a light source device, the light source device can be preferably used as light for irradiating various patterns. In this case, the light source device is not limited to a light source that outputs light in the aforementioned predetermined wavelength range, and may include light sources that output light in various wavelength ranges.

Possibility of industrial use

According to the present invention, there are provided a metal heating device, a metal heating method, and a light source device capable of efficiently heating an object.

Claims (18)

1. A metal heating method, characterized in that: comprising the step of supplying a second metal member onto the first metal member, and a step of irradiating light to both the first metal member and the second metal member; The above-mentioned first metal member contains gold as a main component; In the step of irradiating the light, the light having a wavelength at which the reflectance of the second metal member is greater than the reflectance of the first metal member is irradiated. 2. The metal heating method according to claim 1, wherein the second metal member is solder. 3. The metal heating method according to claim 1 or 2, wherein the second metal member is mainly composed of tin, The central wavelength of the above-mentioned light is 550 nm or less. 4. A metal heating method, characterized by comprising the step of supplying a second metal member onto the first metal member, and a step of irradiating light to both the first metal member and the second metal member; The above-mentioned first metal member contains gold as a main component; In the step of irradiating the light, the light is irradiated so that the light irradiation area of the first metal member is larger than the light irradiation area of the second metal member. 5. The metal heating method according to claim 4, wherein the central wavelength of the light is less than 600 nm. 6. The metal heating method according to claim 5, wherein the second metal member is solder mainly composed of tin. 7. A method of heating metal, comprising the steps of supplying a second metal member onto the first metal member, and a step of irradiating light to both the first metal member and the second metal member; The above-mentioned first metal member contains gold as a main component; In the step of irradiating the light, the light is irradiated so that the amount of energy applied to the first metal member is greater than the amount of energy applied to the second metal member. 8. The metal heating method according to claim 7, wherein the second metal member is solder. 9. The metal heating method according to claim 7 or 8, wherein the second metal member contains tin as a main component. 10. A method of heating metal, comprising the steps of supplying a second metal member onto the first metal member, and a step of irradiating light to both the first metal member and the second metal member; The above-mentioned first metal member contains gold as a main component; In the step of irradiating the light, light of the first center wavelength and light of the second center wavelength are irradiated as the light. 11. The metal heating method according to claim 10, wherein the light of the first central wavelength and the light of the second central wavelength are emitted from the same position. 12. The metal heating method according to claim 11, further comprising the step of guiding the light of the first center wavelength and the light of the second center wavelength through a shared optical fiber, In the step of irradiating the light, the light of the first center wavelength and the light of the second center wavelength are respectively emitted from the end face of the optical fiber, and irradiated onto the first metal member and the second metal member. 13. The metal heating method according to claim 10, wherein in the step of irradiating the light, the first metal member is irradiated with a light irradiation area larger than the light irradiation area of the second metal member. light at the center wavelength, and at the same time, The light irradiation area of the said 2nd metal member is made larger than the light irradiation area of the said 1st metal member, and the light of the said 2nd center wavelength is irradiated. 14. The metal heating method according to claim 13, further comprising the step of guiding the light of the first central wavelength and the light of the second central wavelength by a bundled optical fiber, In the step of irradiating the light, the light of the first central wavelength and the light of the second central wavelength are respectively emitted from mutually different emission positions of the bundled optical fiber, and are irradiated onto the first metal member and the second metal member. member. 15. The metal heating method according to claim 10, wherein the respective center wavelengths of the light having the first center wavelength and the light having the second center wavelength are different from each other by 100 nm or more. 16. The metal heating method according to claim 10, wherein the first central wavelength is less than 600 nm. 17. The metal heating method according to claim 10, wherein the second metal member contains tin as a main component, and the second center wavelength is 600 nm or more. 18. The metal heating method according to claim 17, wherein the second metal member is solder.

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