JP2006148152A - Soldering equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide soldering equipment, capable of uniformly heating a printed circuit board and the mounted electronic components, and of soldering, without thermally damaging the electronic components in soldering equipment using lead-free solder. <P>SOLUTION: The pressure of a fluid is allowed to be uniform and a porous body 130, having a plurality of pores, is disposed between a blower fan 122 and a heater 140. In addition, a radiation plate 150, that sprays the fluid heated by the heater 140 onto a heated object 10 as turbulent flow, is disposed between the heater 140 and the heated object 10, and the heated object is heated by spraying the heated fluid onto the heated object and melts the solder. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a soldering apparatus, and more particularly to a soldering apparatus suitable for using lead-free solder.

  In a conventional soldering apparatus, an infrared heater is used as a heat source for heating the solder to the melting point or higher, as described in, for example, Japanese Patent Application Laid-Open Nos. 6-253465 and 10-335047. Known are those that directly heat an object to be heated, and those that spray a fluid heated by an infrared heater onto the object to be heated, as described in JP-A-11-54903 and JP-A-9-186448. It has been.

JP-A-6-253465 Japanese Patent Laid-Open No. 10-335047 JP-A-11-54903 JP-A-9-186448

  Recently, as a solder used in a soldering apparatus, it has been attempted to use a lead-free solder containing no lead in place of a conventional lead-containing solder from the viewpoint of reducing pollution. Known lead-free solders include tin-silver solder (SnAg), tin-copper solder (SnCu), and tin-silver solder (SnAg) with bismuth (Bi) added. These lead-free solders have a melting point higher than that of conventional lead solders. For example, the melting point of SnAg solder is 221 ° C., the melting point of SnCu solder is 227 ° C., and the melting point of Bi-containing SnAg solder is 205. ° C. That is, the melting point of lead-free solder is 200 to 230 ° C., which is higher than that of lead solder.

  On the other hand, as electronic parts to be soldered on a printed board, there are SOP type ICs, QFP type ICs, chip parts such as resistors and capacitors, electrolytic capacitors, and the like. Some of these soldered parts have a heat resistant temperature close to the melting point of lead-free solder. For example, the heat resistant temperature of the aluminum electrolytic capacitor is 250 ° C. Therefore, when soldering using a solder having a melting point of 227 ° C., it is necessary to heat the solder to a temperature equal to or higher than the melting point, for example, 230 ° C. Considering the heat resistant temperature of electronic components mounted on a printed circuit board, It is necessary to control the temperature to 240 ° C. or lower. That is, it is necessary to control the heating temperature to be in the range of 230 to 240 ° C.

  However, as described in JP-A-6-253465 and JP-A-10-335047, an object to be heated directly using an infrared heater is affected by the shape of the heater. Therefore, when heated above the melting point of the solder, it may be partially heated above the heat resistance temperature of the electronic component mounted on the printed circuit board. In such a case, the electronic component may be thermally damaged. Will give. In addition, as described in JP-A-11-54903 and JP-A-9-186448, in the case where a fluid heated by an infrared heater is sprayed on an object to be heated, the infrared heater is used to directly cover the object. Although there is less variation in temperature distribution than that for heating heated objects, all the printed circuit boards that are heated members and their mounted electronic components are uniformly heated so that the heating temperature is in the range of 230 to 240 ° C. However, there is a problem that temperature damage is caused to the electronic component.

  An object of the present invention is to provide a soldering apparatus using a lead-free solder, which can uniformly heat a printed circuit board and an electronic component mounted thereon, and can perform soldering without causing thermal damage to the electronic component. It is to provide.

  (1) In order to achieve the above object, the present invention provides a soldering apparatus having a heating furnace unit that heats a fluid to be heated by heating a fluid sent from a blower with a heater and spraying the heating fluid onto the object to be heated. A porous body that is disposed between the blower and the heater, uniformizes the pressure of the fluid sent from the blower, and has a plurality of holes that can ventilate the heater, the heater, and the heater A radiation plate is disposed between the objects to be heated and sprays the object to be heated as a turbulent flow of the fluid heated by the heater. With this configuration, in a soldering apparatus using lead-free solder, the printed circuit board and the electronic components mounted thereon can be heated uniformly, and soldering can be performed without causing thermal damage to the electronic components.

  (2) In the above (1), preferably, the heating furnace unit is further provided with at least one of the radiation plate or the heater, and is provided on the heated object side and transmits infrared rays emitted from the heater. Among them, an absorber that absorbs infrared wavelengths of 1 μm or less and 20 μm or more is provided. With this configuration, the object to be heated is irradiated with a far infrared wavelength of 1 μm to 20 μm, and the temperature of the IC or the like of the black mold can be easily controlled so as to be lower than the heat resistant temperature.

  (3) In the above (1), preferably, a plurality of the heating furnace units are connected in the conveying direction of the heated object, and a fluid flow is formed in a direction opposite to the conveying direction of the heated object. It is a thing. With this configuration, it is possible to prevent a decrease in the temperature of the soldering portion.

  (4) In the above (1), preferably, it further includes a cooling unit that cools the object to be heated heated by the heating furnace unit, and the cooling unit includes a blower that blows a cooling fluid onto the object to be heated. A cooler that cools the fluid heated by the object to be heated, and is arranged between the blower and the object to be heated, and makes the pressure of the fluid sent from the fan uniform, and against the object to be heated And a porous body having a plurality of holes that can be ventilated. With this configuration, by rapidly cooling the object to be heated, the internal structure of the solder is refined, the Ag3Sn needle crystals in the solder are suppressed, and the soldering defect that peels from the conductor of the object to be heated and the soldered part of the electronic component is eliminated. It can be suppressed.

  (5) In the above (1), preferably, a plurality of the cooling units are connected in the conveying direction of the heated object, and a fluid flow is formed in the direction opposite to the conveying direction of the heated object. Is. With this configuration, the consumption of the inert gas can be reduced by flowing the cooling fluid in the direction opposite to the conveying direction of the object to be heated.

  According to the present invention, in a soldering apparatus using lead-free solder, the printed circuit board and the electronic component mounted thereon can be heated uniformly, and soldering can be performed without causing thermal damage to the electronic component.

  Hereinafter, the configuration of a soldering apparatus according to an embodiment of the present invention will be described with reference to FIGS. Initially, the whole structure of the soldering apparatus by this embodiment is demonstrated using FIG. FIG. 1 is a front view showing an overall configuration of a soldering apparatus according to an embodiment of the present invention.

  The soldering apparatus includes a continuous heating furnace unit 100, a cooling unit 200, inert gas chambers 310 and 320, and a transfer conveyor 50, and constitutes a reflow furnace. The continuous heating furnace unit 100 includes a preheating unit 100A and a soldering unit 100B. The preheating unit 100A and the soldering unit 100B are configured by heating furnace units 110A, 110B, 110C, 110D, and 110E and heating furnace units 110G and 110H, respectively, and the heating furnace units 110A,. The configuration is basically the same. The detailed configuration of the heating furnace units 110A,..., 110H will be described later with reference to FIGS. 100 A of preheating parts heat the to-be-heated material 10 to 160-200 degreeC, for example, and raise the temperature of the printed circuit board which is the to-be-heated material 10, and the electronic component mounted on this printed circuit board. The soldering unit 100B heats the article to be heated 10 to a melting point or higher, for example, 240 ° C. to melt the solder, and solders the printed circuit board and the electronic component.

  The cooling unit 200 includes cooling units 210A and 210B, and the configuration of these cooling units 210A and 210B is basically the same. The detailed configuration of the heating furnace units 110A,..., 110H will be described later with reference to FIG. The cooling unit 200, for example, rapidly cools the object to be heated 10 heated to 240 ° C. to room temperature, fixes the solder, and completes the soldering.

  The inert gas chamber 310 includes an opening / closing part 312 on the inlet side. The inert gas chamber 320 includes an opening / closing part 322 on the outlet side. The opening / closing sections 312 and 322 are openable / closable curtains and doors. When the object to be heated 10 transported by the transport conveyor 50 is carried into the inert gas chamber 310 or unloaded from the inert gas chamber 320. Open, and allows the object to be heated 10 to be carried in and out, and closed otherwise, and the nitrogen gas in the continuous heating furnace part 100, the cooling part 200, and the inert gas chambers 310 and 320 is closed. Such an inert gas is prevented from flowing out to the outside. In the continuous heating furnace unit 100, the cooling unit 200, and the inert gas chambers 310 and 320, an inert gas is introduced to reduce surface oxidation when the solder is melted.

  Next, the operation of the soldering apparatus according to the present embodiment will be described. The article to be heated 10 is carried into the inert gas chamber 310 by the conveyor 50. When the article to be heated 10 is carried in, the opening / closing part 312 is opened, and after the article 10 is carried in, the opening / closing part 312 is closed. The article to be heated 10 is conveyed to the preheating part 100 </ b> A of the continuous heating furnace part 100 by the conveying conveyor 50. The internal atmospheres of the heating furnace units 110A, 110B, 110C, 110D, and 110E of the preheating unit 100A are maintained at 180 ° C., for example. The object to be heated 10 conveyed by the conveyor 50 is gradually heated by the heating furnace units 110A, 110B, 110C, 110D, and 110E, and finally the internal atmospheric temperature (for example, 180 ° C.) in the heating furnace unit 110E. The printed circuit board which is the object to be heated 10 and the electronic component mounted thereon are heated.

  Next, the object to be heated 10 is conveyed by the conveying conveyor 50 to the soldering part 100B of the continuous heating furnace part 100. The internal atmosphere of each of the heating furnace units 110G and 110H in the soldering unit 100B is kept at 240 ° C., for example. The article to be heated 10 conveyed by the conveyer 50 is heated by the heating furnace units 110G and 110H, respectively. In the heating furnace unit 110H, the article to be heated 10 is finally heated to the internal atmospheric temperature (for example, 240 ° C.). The printed circuit board and the electronic components mounted thereon are heated and the solder is melted.

  Next, the object to be heated 10 is transported to the cooling unit 200 by the transport conveyor 50. The inside of the cooling units 210A and 210B of the cooling unit 200 is kept at a low temperature by, for example, air cooled to 30 ° C. and an inert gas. The article to be heated 10 conveyed by the conveyor 50 is cooled to, for example, 60 to 80 ° C. by the cooling unit 210A, and further cooled to, for example, 30 ° C. by the cooling unit 210B.

  The object to be heated 10 cooled to room temperature is carried out of the inert gas chamber 320 by the transfer conveyor 50. When the article to be heated 10 is carried out, the opening / closing part 322 is opened, and after the article to be heated 10 is carried out, the opening / closing part 322 is closed.

  Next, an example of an object to be heated to be soldered by the soldering apparatus according to the present embodiment will be described with reference to FIG. FIG. 2 is a perspective view showing a configuration of an example of an object to be heated soldered by the soldering apparatus according to the embodiment of the present invention.

  The object to be heated 10 includes a printed circuit board 12 and an electronic component 14 mounted on the printed circuit board 12 and soldered. Wiring is formed in advance on the printed circuit board 12, and solder paste is printed at the mounting position of the electronic component 14. Examples of the electronic component 14 include an SOP type IC 14A, a QFP type IC 14B, a chip component 14C such as a resistor and a capacitor, and an electrolytic capacitor 14D. Here, the heat resistant temperature of the aluminum electrolytic capacitor is, for example, 250 ° C. Further, according to the study by the present inventors, it has been found that the ease of temperature control differs depending on the wavelength of infrared rays to be irradiated in the black mold SOP type IC 14A. For example, since infrared rays having a wavelength of 1 μm or less are easily absorbed by the black mold, the temperature easily rises, and it is difficult to control the temperature so that the temperature reaches a predetermined temperature. In addition, since infrared rays having a wavelength of 20 μm or more are hardly absorbed by the black mold, the temperature does not easily rise, and it is difficult to control the temperature so as to reach a predetermined temperature.

  Next, the configuration of the heating furnace unit 110 used in the soldering apparatus according to the present embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a cross-sectional view showing a configuration of a heating furnace unit used in the soldering apparatus according to the embodiment of the present invention. The X, Y, and Z axes shown in FIG. 3 are the same as the X, Y, and Z axes in FIG. 1, and the heating furnace unit 110 in FIG. 3 is the same as the X in the heating furnace units 110A,. It is sectional drawing of -Z surface. FIG. 4 is a plan view showing a configuration of a radiation plate used in a heating furnace unit used in a soldering apparatus according to an embodiment of the present invention.

  The heating furnace unit 110 according to the present embodiment includes a motor 120 and a blower fan 122 as a mechanism for blowing fluid. The blower fan 122 is connected to the rotating shaft of the motor 120 by a shaft 124. The shaft 124 is supported by a bearing (not shown). The heating furnace unit 110 according to the present embodiment includes a porous plate 130, a cast-in heater 140, and a radiation plate 150. Surface treatment parts 142 and 152 are formed on the side of the cast-in heater 140 and the radiation plate 150 facing the object to be heated 10. The cast heater 140 is formed by casting a bar heater 144 therein. Further, the cast heater 140 has a plurality of slits 146 formed therein. Furthermore, casings 160A and 160B are respectively provided before and after the conveyance direction (X direction) of the article 10 to be heated by the conveyance conveyor 50, and fluid passages 162A and 162B are formed therein.

  The state shown in FIG. 3 shows the configuration of the heating furnace unit in the upper half of the transport conveyor 50. The motor 120, the blower fan 122, the porous plate 130, A heating furnace unit including a cast-in heater 140 and a radiation plate 150 is provided, and the heated object 10 on the transport conveyor 50 is heated from above and below.

  The blower fan 122 rotated by the motor 120 sucks and pressurizes the fluid (for example, air or inert gas) on the back side and blows it into the space C in the direction of the arrow B1. The space C is a space partitioned by the casing and the porous plate 130. However, since many holes are formed in the porous plate 130, the porous plate 130 communicates with the cast-in heater 140 and the radiation plate 150. Since the space C communicates with other spaces only through the porous plate 130 as described above, the internal fluid pressure rises. The fluid whose internal pressure has risen is ejected from the many holes of the porous plate 130 toward the radiation plate 150. The fluid ejected from the porous plate 130 is heated by the casting heater 140 and ejected from the slit 146 in the direction of the radiation plate 150 (arrow B2 direction).

  Thus, since the fluid pressurized by the blower fan 122 is pressurized to a predetermined pressure in the space C and then ejected from the porous plate 130, for example, the fluid ejected from the blower fan 122 Even if there is a velocity distribution, since the internal pressure of the space C rises to a constant pressure, the variation in the velocity of the fluid ejected from the porous plate 130 can be reduced, and a fluid having a substantially constant velocity can be obtained. The speed of the fluid ejected from the slit 146 of the cast-in heater 140 is a high speed and constant, for example, 20 m / s. In this embodiment, the fluid heated at high speed is sprayed on the object 10 to be heated, so that the heat exchange efficiency is improved and the temperature of the object 10 is rapidly increased.

  Further, by using an alloy of platinum (Pt), copper (Cu), and manganese (Mn) as the material of the porous plate 130, the porous plate 130 can have a catalytic action for decomposing flux. As will be described later, the heated fluid blown to the object to be heated 10 is circulated from the blower fan 122 to the space C through the fluid passage 162. When the solder of the article to be heated 10 is melted, a flux is generated, and this flux is circulated in the space C. Here, the flux adhering to the surface of the porous plate 130 is decomposed by an alloy having a catalytic action of latina (Pt), copper (Cu), manganese (Mn), and can prevent clogging of the porous material. . The porous plate 130 can be removed from the heating furnace unit 110, and can be removed to remove the flux.

  Here, the configuration of the radiation plate 150 will be described with reference to FIG. A plurality of small holes 154 are formed in the radiation plate 150. The plurality of small holes 154 are formed at the positions of the apexes of the equilateral triangle, and the distances A1, A2, and A3 between the small holes arranged in a row are equal. The diameter of the small hole 154 is φ2 to φ5 (mm), for example, φ3.5 (mm). At this time, the distances A1, A2, and A3 between the small holes arranged in a row are set to 20 (mm). By setting the dimensions and arrangement of the small holes 154, the fluid ejected from the radiation plate 150 in the direction of the arrow B3 can be a turbulent flow having a Karman vortex. The fluid ejected from the slit 146 of the cast-in heater 140 is almost laminar, and the velocity thereof is, for example, 20 m / s and a high-speed fluid as described above. When this high-speed fluid is sprayed on the object to be heated 10 in a laminar flow state, the electronic components on the object to be heated 10 are skipped or misaligned due to the flow velocity. The electronic component placed on the solder paste of the printed circuit board is merely placed on the solder paste, and is not particularly fixed. Therefore, misalignment easily occurs due to the high-speed fluid. In order to prevent such misalignment, the radiation plate 150 in which the small holes 154 are formed is used to prevent the misalignment of the electronic component by using the high-speed fluid blown to the heated object 10 as a turbulent flow. I have to. The small holes 154 are not limited to being arranged at the vertices of an equilateral triangle, but can also be arranged at the vertices of an isosceles triangle. That is, the distance A1 = A2 between the small holes 154 can be set, and A1> A3.

  The temperature of the heating fluid blown out from the radiation plate 150 is detected by a temperature sensor, and the temperature of the heating fluid is controlled to a predetermined temperature (for example, 180 ° C. in the pre-heater unit 100A, and soldering unit 100B in the soldering unit 100B). 240 ° C.).

  The heated fluid blown to the article to be heated 10 is sucked and circulated by the blower fan 122 from the fluid passages 162A and 162B in the casings 160A and 160B. Here, the width W1 of the fluid passage 162A is wider than the width W2 of the fluid passage 162B. That is, the width W1 of the fluid passage 162A formed in the transport direction of the article to be heated 10 by the transport conveyor 50 is wider than the width W2 of the fluid passage 162B formed in the reverse transport direction. The width W1 is, for example, 10 cm, and the width W2 is, for example, 20 cm. As shown in FIG. 1, the heating furnace units 110A,..., 110H are connected in tandem in the transport direction. Therefore, as shown in FIG. 3, in the reverse conveying direction of the heating furnace unit 110, fluid passages 162A 'of other heating furnace units 110' connected in cascade are provided in parallel. Since the width W1 of the fluid passage 162A ′ is wider than the width W2 of the fluid passage 162B, the heated fluid blown to the object to be heated 10 is sucked toward the adjacent heating furnace unit 110 ′ as the flow of the arrow B4. This amount can be larger than the amount sucked into its own heating furnace unit 110 as the flow of the arrow B5. As a result, a fluid flow from the heating furnace unit 110H toward the heating furnace unit 110A can be formed inside the heating furnace units 110A,..., 110H shown in FIG. Since the internal temperature of the heating furnace units 110A,..., 110E is lower than the internal temperature of the heating furnace units 110G, 110H, when the flow of fluid from the heating furnace unit 110E toward the heating furnace unit 110G is formed, the heating is performed. Although the internal temperature of the furnace unit 110G is lowered, the flow of the heating fluid from the heating furnace unit 110G toward the heating furnace unit 110H is formed to prevent the internal temperature of the heating furnace units 110G and 110H from being lowered. be able to.

  Next, functions of the surface treatment units 142 and 152 will be described. The surface treatment unit 142 is a ceramic sprayed film formed on the surface of the casting heater 140. Similarly, the surface treatment unit 152 is a ceramic sprayed film formed on the surface of the radiation plate 150. As described above, in particular, in the black mold SOP type IC 14A, the ease of temperature control varies depending on the wavelength of the infrared rays to be irradiated. Therefore, the object to be heated 10 is irradiated with infrared rays having a wavelength of 1 μm or more and 20 μm or less. It has been found that more accurate temperature control is possible by doing so. The surface treatment parts 142 and 152 are used to absorb infrared rays having a wavelength other than 1 to 20 μm and irradiate the object to be heated 10 with infrared rays having a wavelength in the range of 1 to 20 μm. Further, by using aluminum as the outer peripheral material of the rod heater of the cast-in heater 140 and the material of the radiation plate 150, infrared radiation with a wavelength of 1 μm or less is suppressed.

  When the surface treatment parts 142 and 152 are, for example, ceramic sprayed films mainly composed of alumina (Al 2 O 3) / titania (TiO 2), the infrared radiation wavelength emitted from the surface treatment parts 142 and 152 is 9 ± 1 (μm). The emissivity of this radiation wavelength is 0.98. Moreover, the service temperature of the surface treatment parts 142 and 152 is 540 ° C., and can sufficiently withstand use. In this way, when the emission wavelength of the emitted infrared rays is 9 ± 1 (μm) and the emissivity is 0.98, the infrared rays are emitted to the object to be heated. (ΔT) could be 5 ° C. and could be controlled in the range of 230 to 240 ° C.

  As another ceramic sprayed film, for example, a ceramic sprayed film mainly composed of chromia (Cr2O3) (infrared radiation wavelength: 12 ± 1 (μm), emissivity: 0.97) may be used. Further, a ceramic sprayed film mainly composed of alumina (Al2O3) (infrared radiation wavelength: 9 ± 1 (μm), emissivity: 0.93) and a ceramic sprayed film mainly composed of titania (TiO2) ( Infrared radiation wavelength: 7 ± 5 (μm), emissivity: 0.85) and ceramic sprayed film with alumina (Al2O3) and zirconia (ZrO2) as main components (infrared radiation wavelength: 9 ± 1 (μm) , Emissivity: 0.98) and ceramic sprayed film (infrared emission wavelength: 11 ± 2 (μm), emissivity: 0.95) mainly composed of zirconia (ZrO2) and yttria (Y2O3) You can also.

  In the above example, the two surface treatment units 142 and 152 are used, but only one of them may be used. For example, since the surface treatment unit 152 is formed on the surface of the thin plate-shaped radiation plate 150 by thermal spraying, it is easier to spray than the surface treatment unit 142 formed on the surface of the casting heater 140 and is manufactured at a low cost. be able to.

  Next, the configuration of the cooling unit 210 used in the soldering apparatus according to the present embodiment will be described with reference to FIG. FIG. 5 is a cross-sectional view showing a configuration of a cooling unit used in the soldering apparatus according to the embodiment of the present invention. The X, Y, and Z axes shown in FIG. 5 are the same as the X, Y, and Z axes in FIG. 1, and the cooling unit 210 in FIG. 5 is the YZ of the cooling units 210A and 210B in FIG. It is sectional drawing of a surface.

  The cooling unit 210 according to the present embodiment includes a motor 220 and a blower fan 222 as a mechanism for blowing fluid. The blower fan 222 is connected to the rotating shaft of the motor 220 by a shaft 224. The shaft 224 is supported by a bearing (not shown). The cooling unit 210 according to the present embodiment includes a porous plate 230, a water-cooled heat exchanger 240, a heat sink 250, and an inert gas pipe 260. Further, casings 270C and 270D are respectively provided on the left and right of the direction (Y direction) orthogonal to the conveying direction of the article to be heated 10 by the conveyor 50, and fluid passages 272C and 272D are formed therein. Has been.

  The blower fan 222 rotated by the motor 220 sucks and pressurizes the fluid (for example, air or inert gas) on the back side and blows it into the space D in the direction of the arrow B11. The space D is a space partitioned by the casing 270 and the porous plate 230. However, since many holes are formed in the porous plate 230, the porous plate 230 communicates with the transport conveyor 50. Since the space D communicates with other spaces only through the porous plate 230 as described above, the internal fluid pressure rises. The fluid whose internal pressure has increased is ejected from the many holes of the porous plate 230 in the direction of the conveyor 50.

  Thus, the fluid pressurized by the blower fan 222 is pressurized to a predetermined pressure in the space D and then ejected from the porous plate 230. For example, the fluid ejected from the blower fan 222 is Even if there is a velocity distribution, since the internal pressure of the space D rises to a constant pressure, the variation in the velocity of the fluid ejected from the porous plate 230 can be reduced, and a fluid having a substantially constant velocity can be obtained. In the present embodiment, the fluid cooled at high speed is sprayed on the object to be heated 10 to improve the heat exchange efficiency, so that the temperature of the object to be heated 10 is rapidly lowered, that is, rapidly cooled. ing. Further, an inert gas such as nitrogen gas is jetted from the inert gas pipe 260 and sprayed onto the article to be heated 10 to cool the article 10 to be heated. The temperature of the inert gas is 20 ° C., for example.

  Further, by using an alloy of platinum (Pt), copper (Cu), and manganese (Mn) as the material of the porous plate 240, the porous plate 240 can have a catalytic action for decomposing flux. Here, the flux adhering to the surface of the porous plate 240 is decomposed by an alloy having a catalytic action of platinum (Pt), copper (Cu), manganese (Mn), and can prevent clogging of the porous. . The porous plate 240 can be removed from the cooling unit 210, and can be removed to remove the flux.

  The cooling fluid blown to the article to be heated 10 is sucked and circulated by the blower fan 222 from the fluid passages 272C and 272D in the casings 270C and 270D. A water-cooled heat exchanger 240 and a heat sink 250 are arranged in the circulation flow path from the article to be heated 10 to the blower fan 222, and recools the cooling fluid that has been heated by cooling the article to be heated 10.

  Here, as shown in FIG. 1, the cooling unit 200 includes two cooling units 210 </ b> A and 210 </ b> B that are cascade-connected in the transport direction by the transport conveyor 50. The cooling unit 210 shown by the solid line in FIG. 5 is the cooling unit 210B (connected in the transport direction) of FIG. 1R> 1, and the width of the fluid passages 272C and 272D is W3. On the other hand, as indicated by the wavy line in FIG. 5, the width of the fluid passages 272C ′ and 272D ′ of the cooling unit 210A connected in the direction opposite to the conveying direction of the cooling unit 210B is W4, and the width W4 is greater than the width W3. It is also wide. The width W4 is, for example, 20 cm, and the width W3 is, for example, 10 cm. Accordingly, since the width W4 of the fluid passages 272C ′ and 272D ′ is wider than the width W3 of the fluid passages 272C and 272D, the cooling fluid blown to the object to be heated 10 in the cooling unit 210B is adjacent to the cooling unit 210A. The amount sucked to the side can be made larger than the amount sucked by its own cooling unit 210B. As a result, a cooling fluid flow from the cooling unit 210B toward the cooling unit 210A can be formed inside the cooling units 210A and 210B shown in FIG.

  An inert gas chamber 320 having an opening / closing part 322 on the outlet side is arranged on the conveyance direction side of the cooling unit 210B, and when the heated object 10 is carried out, the opening / closing part 322 of the inert gas chamber 320 is disposed. It is inevitable that the inert gas flows out of the tank. However, in this embodiment, since the flow of the cooling fluid flowing from the cooling unit 210B toward the cooling unit 210A can be formed, the outflow amount of the inert gas can be reduced. Therefore, the consumption of expensive inert gas can be reduced.

  In the present embodiment, a high-speed uniform flow (velocity) is sprayed on the object to be heated to increase the heat exchange efficiency of the cooling, thereby rapidly cooling the object to be heated. . Therefore, the solder internal structure can be miniaturized. Further, Ag3Sn needle-like crystals in the solder can be suppressed. Furthermore, it is possible to suppress soldering defects that peel from the conductor of the object to be heated and the soldered portion of the electronic component.

  Next, the configuration of another heating furnace unit 110 'used in the soldering apparatus according to the present embodiment will be described with reference to FIG. FIG. 6 is a cross-sectional view showing the configuration of another heating furnace unit used in the soldering apparatus according to the embodiment of the present invention. The X, Y, and Z axes shown in FIG. 6 are the same as the X, Y, and Z axes in FIG. 1, and the heating furnace unit 110 ′ in FIG. 6 corresponds to the heating furnace units 110 </ b> A,. It is sectional drawing of a XZ surface. The same reference numerals as those in FIG. 3 denote the same parts.

  The heating furnace unit 110 ′ according to the present embodiment includes a motor 120, a blower fan 122, a porous plate 130, and a radiation plate 150, similarly to the heating furnace unit 110 illustrated in FIG. 3. In the present embodiment, the configuration of the heater 140A is different.

  The heater 140 </ b> A includes a bar heater 144 and heat radiating fins 148 attached to the bar heater 144. The heat dissipating fins 148 are composed of a plurality of fins aligned in the Y direction in the figure, and perform infrared radiation from the bar heater 144 widely and uniformly. In addition, as a radiation fin, what was made to wind around the outer periphery of the rod heater 144 helically can also be used.

As described above, according to the present embodiment, the pressure is increased by using the porous plate, the high-speed heating fluid having a uniform flow rate from the porous is heated by the heater, and the high-speed heating fluid is obtained. By forming a Karman vortex turbulent flow using a plate and then spraying the object to be heated, the object to be heated can be uniformly heated at high speed. Therefore, the temperature difference of the object to be heated can be reduced. In particular, in lead-free solder, the difference between the melting point of the solder and the heat resistance temperature of the electronic component is small, so by performing uniform heating, the lead-free solder can be melted without causing thermal damage to the electronic component, Soldering can be performed. In addition, by providing a surface treatment unit, it is possible to easily control the temperature of the IC of the black mold to be lower than the heat-resistant temperature by irradiating the object to be heated with a far infrared wavelength of 1 μm to 20 μm. It becomes. Furthermore, in the heating part, it is possible to prevent the temperature of the soldering part from decreasing by flowing the heating fluid in the direction opposite to the conveying direction of the object to be heated. In the cooling unit, the consumption of the inert gas can be reduced by flowing the cooling fluid in the direction opposite to the conveying direction of the object to be heated. Furthermore, by rapidly cooling the object to be heated, the internal structure of the solder is made finer, the Ag3Sn needle crystals in the solder are suppressed, and the soldering defect that peels from the conductor of the object to be heated and the soldered part of the electronic component is eliminated. Can be suppressed.

It is a front view showing the whole soldering device composition by one embodiment of the present invention. It is a perspective view which shows the structure of an example of the to-be-heated material soldered by the soldering apparatus by one Embodiment of this invention. It is sectional drawing which shows the structure of the heating furnace unit used for the soldering apparatus by one Embodiment of this invention. It is a top view which shows the structure of the radiation board used for the heating furnace unit used for the soldering apparatus by one Embodiment of this invention. It is sectional drawing which shows the structure of the cooling unit used for the soldering apparatus by one Embodiment of this invention. It is sectional drawing which shows the structure of the other heating furnace unit used for the soldering apparatus by one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Heated object 50 ... Conveyor 100 ... Continuous heating furnace part 100A ... Preheating part 100B ... Soldering part 110 ... Heating furnace unit 120, 220 ... Motor 122, 222 ... Blower fan 130, 230 ... Porous board 140 ... Casting Heater 142, 152 ... Surface treatment unit 150 ... Radiation plate 160, 270 ... Casing 200 ... Cooling unit 210 ... Cooling unit 240 ... Water-cooled heat exchanger 250 ... Heat sink 260 ... Inert gas pipe 310, 320 ... Inert gas chamber 312, 322 ... Opening / closing part

Claims (4)

In a soldering apparatus having a heating furnace unit for heating a fluid to be heated by heating a fluid sent from a blower with a heater and spraying the heating fluid on the object to be heated.
A porous body that is disposed between the blower and the heater and has a plurality of holes that can ventilate the heater while making the pressure of the fluid sent from the blower uniform.
A soldering apparatus, comprising: a radiation plate that is disposed between the heater and the object to be heated and sprays the fluid heated by the heater as a turbulent flow onto the object to be heated. The soldering apparatus according to claim 1,
A soldering apparatus, wherein a plurality of the heating furnace units are connected in a conveying direction of the object to be heated, and a fluid flow is formed in a direction opposite to the conveying direction of the object to be heated. The soldering apparatus according to claim 1,
Furthermore, a cooling unit for cooling an object to be heated heated by the heating furnace unit is provided,
The cooling unit is disposed between a blower that blows a cooling fluid onto the object to be heated, a cooler that cools the fluid heated by the object to be heated, and the fan and the object to be heated. A soldering apparatus comprising: a porous body having a plurality of holes through which the pressure of fluid to be fed is made uniform and can be ventilated to the object to be heated. The soldering apparatus according to claim 3,
A plurality of the cooling units are connected in the conveying direction of the heated object, and a fluid flow is formed in a direction opposite to the conveying direction of the heated object.

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