JPH084927B2 - Vapor condensing device in vapor phase soldering equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention provides latent heat of vaporization during a phase change to a work to melt the cream solder previously applied to the work, or The present invention relates to a vapor condensing device for maintaining vapor in a main body of a device in a vapor phase type soldering device for applying a latent heat of vaporization to a solder-coated work to perform fading.

(Prior Art) As shown in FIG. 5, in an in-line vapor-phase soldering apparatus, an inert liquid 12 contained in a bottom portion of a steam tank 11 forming a part of the apparatus main body is heated by a heater 13. It is heated and evaporated, a saturated vapor phase 14 is formed inside the steam tank 11, and is carried into the inside of the steam tank 11 by a work transfer conveyor 16 via a work carry-in port 15 provided on one side of the steam tank 11. Saturated vapor phase 14 on the separated work (printed wiring board) W
Is applied to melt the cream solder interposed between the printed wiring board as a work and the board-mounted component. The work W is taken out through the work carry-out port 17 provided on the other side of the steam tank 11. The steam tank 11, the work loading port 15 and the work loading port 17
The main body of the device is constituted by.

The saturated vapor phase 14 formed inside the steam tank 11 is kept in a certain area by the carry-in inlet portion 15, the carry-out outlet portion 17 and the steam condensers 18 provided on the upper inner wall of the steam tank 11, respectively, and externally. Outflow to

Then, the temperature of the work W conveyed by the conveyor 16 is raised by the external preheater 21, the raised temperature is kept by the heat retaining heater 22 provided at the work carry-in port 15, and the reflow soldering is performed by the saturated vapor phase 14. And is carried out to the outside through the work carrying-out port section 17. If the work cooling device 23 is provided at the carry-out port 17, the work W can be rapidly cooled by the work cooling device 23.

In such a vapor-phase soldering apparatus, the conventional vapor condenser 18 has a cooling coil (a low-efficiency type is a simple cooling coil, and a high-efficiency type is a cross-fin type cooling coil provided with heat absorbing fins) for transferring the work. It is arranged on the upper side and the lower side of the conveyor 16, etc. These condensing devices 18
In order to liquefy the steam, the temperature of tap water as a cooling medium is adjusted so that a dew point does not occur on the coil surface, and then the water is passed to condense and liquefy.

(Problems to be solved by the invention) However, since the inert liquid 12 heated to a high temperature is contained in the bottom of the steam tank 11, cracks and tap water due to aged deterioration occur in the coil of the steam condenser 18. When a minute hole of a level of water leakage occurs, water leakage from the coil flows through the bottom plate of the carry-in port 15 and the carry-out port 17 into the high temperature inert liquid 12, and the liquid 12 bumps and explodes. There was a risk to

An object of the present invention is to eliminate the water-flowing cooling coil as a vapor condenser from the inside of the main body of the apparatus, and to completely eliminate the risk of water leakage in the main body coming into contact with the high temperature liquid in the main body.
To eliminate the risk of explosion in the device body.

[Structure of Invention]

(Means for Solving Problems) In the present invention, the vapor phase 14 formed inside the apparatus main body is kept in a certain area by the vapor condensing device 18, and the vapor phase
In the vapor phase soldering device in which the latent heat of vaporization of 14 is applied to the work W carried into the apparatus main body and the work W is reflow-soldered, the vapor condensing device 18 includes a heat pipe 31 inside the device main body. The heat absorbing part 32 is inserted, the remaining part of the heat pipe 31 is drawn out of the main body of the device, and the heat radiating part 33 located on the outside drawing side of the heat pipe 31 is provided with the external cooler 34. is there.

(Operation) In the present invention, the heat energy for condensation released from the vapor phase 14 to the heat absorbing portion 32 of the heat pipe 31 is transferred by the heat pipe 31 to the heat radiating portion 33 outside the apparatus main body, It is forcibly cooled by the cooler 34 outside the main unit,
By depriving the transported thermal energy, vapor is condensed without passing any water in the apparatus main body.

(Example) Hereinafter, the present invention will be described in detail with reference to the examples shown in the drawings.

FIG. 1 shows a vapor condensing device 18 (FIG. 5) in a work carry-out port 17 that constitutes the main body of the apparatus together with the steam tank 11 and the work carry-in port 15. This vapor condenser
18, a large number of heat absorbing portions 32 of a heat pipe 31 formed in a U shape are inserted on the upper side and the lower side of a conveyor 16 that conveys a work W along the conveyor 16 as shown in FIG. A part of the heat pipe 32 other than the heat absorbing part is drawn out to the outside of the carry-out port part 17, and a large-sized external cooler 34 is provided in the heat radiating part 33 located on the outside drawing side of the heat pipe 31. As shown in FIG. 3, the heat absorbing portion 32 of the heat pipe 31 is provided with a large number of heat absorbing fins 35. The external large-sized cooler 34 is a water-cooled cooler whose temperature can be adjusted, and has a serpentine pipe 36 for receiving the cooling water whose temperature is adjusted so as not to connect the dew point on the surface of the water conduit. The work transfer conveyor 16 includes a pair of endless chains arranged in parallel with work receiving portions provided at a predetermined mounting pitch.

The heat pipe 31 is a sealed metal pipe whose both ends are closed, and a capillary material is lined on the inner wall of the metal pipe, the interior of the metal pipe is in a highly decompressed state, and a heat medium such as water, alcohol, or chlorofluorocarbon is appropriately heat-sealed. It is a transportation device and is known to have extremely high thermal conductivity.

In this heat pipe, when heat is applied from the heat absorbing fins 35 to the heat absorbing portion 32, the heat medium under reduced pressure in the pipe boils and evaporates at a low temperature, and absorbs latent heat of vaporization when vaporized,
Then, in the pipe, the vapor moves from the heat absorbing portion 32 to the heat radiating portion 33 at a speed equal to the speed of sound, the vapor in the pipe is condensed and returned to the liquid in the heat radiating portion 33, and when condensing, the latent heat of condensation is released, and The condensed and liquefied heat medium returns to the heat absorbing section 32 through the capillary lining substance. Such circulation of the heat medium proceeds continuously, and heat is continuously transferred from the heat absorbing section 32 to the heat radiating section 33.

Further, FIG. 1 shows a work cooling device 23 (FIG. 5) at the work carry-out port 17. This work cooling device
Reference numeral 23 denotes a heat absorbing portion 42 of a heat pipe 41 formed in a U-shape inside the work carrying-out portion 17, near the upper side and the lower side of the work carrying conveyor 16, respectively.
A large number of the heat pipes 41 are inserted along the line 16 as shown in FIG.
The external compact cooler 44 shown in FIG. 2 is drawn to the outside of the heat pipe 41, and the heat radiating portion 43 located on the outside drawing side of the heat pipe 41.
Is provided. As shown in FIG. 1, the heat absorbing portion 42 of the heat pipe 41 is provided with a large number of heat absorbing fins 45.

The external small cooler 44 is an electric cooler that uses a thermo module that utilizes the Peltier effect, and includes a heat absorbing plate that contacts the heat radiating portion 43 of the heat pipe 41, and a heat radiating plate located below the heat absorbing plate. The thermo module is sandwiched between and integrated with the thermo module. The thermo module absorbs the heat emitted from the heat radiating section 43 through the heat absorbing plate and releases it to the atmosphere through the heat radiating plate.

Then, from the saturated vapor phase 14 to the heat absorption part of the heat pipe 31.
The heat energy for condensation released to 32 is radiated by the heat pipe 31 to the heat radiating section 33 outside the work carrying-out section 17.
And is forcibly cooled by the water-cooled cooler 34 outside the carry-out port 17. In this way, the heat energy is transported to the outside of the apparatus main body and is forcibly cooled outside, so that the vapor is condensed without passing any water into the apparatus main body.

The high-temperature work W reflow-soldered by the saturated vapor phase 14 is rapidly cooled by the work cooling device 23 at the carry-out port 17. That is, the carry-out port section
The heat released from the work W conveyed through the inside 17 is efficiently absorbed by the heat absorbing portion 42 of the heat pipe 41 through the heat absorbing fins 45, and the work pipe unloading portion by the heat pipe 41.
The heat is transferred to the heat radiating section 43 outside the unit 17 and is forcibly cooled by the external thermo module cooler 44. In this way, the thermal energy is transported to the outside of the work unloading port 17 and is forcibly cooled outside, so that the atmosphere surrounding the transfer path of the work W is rapidly cooled without passing any water into the inside thereof. The work W passing through is subjected to a rapid cooling action at a high speed, and the temperature thereof rapidly drops.

Next, FIG. 4 shows a batch type vapor phase soldering apparatus. This is because the saturated vapor phase 14 formed inside the vapor tank 11 as the main body of the apparatus is kept in a certain area by the vapor condensing device 18a provided along the inner wall of the vapor tank 11, and becomes saturated vapor phase 14. On the other hand, the work W is carried down from above, and the latent heat of vaporization in the vapor phase is given to the work.
When is reflow soldered, this work is lifted and taken out. The vapor condensing device 18a,
The heat absorbing portion 52 of the heat pipe 51 is inserted inside the steam tank 11, a large number of heat absorbing fins 53 are provided in the heat absorbing portion 52, and the remaining portion of the heat pipe 51 is pulled out to the outside of the steam tank 11. The heat dissipation part located on the outside extraction side of the pipe 51
The external cooler 55 is provided in 54.

Also in this batch type soldering device, the heat energy for condensation released from the saturated vapor phase 14 to the heat absorbing part 52 of the heat pipe 51 is radiated by the heat pipe 51 outside the steam tank 11 as the device body. Heat transferred to 54, steam tank 11
The heat energy that is forcibly cooled by the cooler 55 and is transported outside is removed, so that the steam in the tank is condensed without passing any water into the steam tank 11.

In addition, when the apparatus main body is composed of the steam tank 11, the work carry-in port 15 and the work carry-out port 17 (FIG. 5)
In addition to the vapor condenser 18 in the carry-out port 17 described in the embodiment shown in FIGS. 1 and 2, the vapor condenser 18 in the carry-in port 15 and the vapor condenser 18 in the upper part of the steam tank 11 Needless to say, the present invention can be used. Further, the thermo-module external cooler 44,
A cooling water flow type cooler may be used.

〔The invention's effect〕

According to the present invention, as the vapor condensing device, the heat absorbing part of the heat pipe is inserted into the inside of the device main body, the remaining part of the heat pipe is drawn out of the device main body, and is located on the external drawing side of the heat pipe. Since an external cooler is provided in the heat radiating section, even if cooling water is supplied to this external cooler to perform efficient cooling, only the excellent cooling effect is transmitted to the inside of the apparatus body through the heat pipe, It is possible to eliminate the risk of bumping and explosion caused by the condensation of steam without passing cooling water into the main body of the apparatus, and the leakage of water inside coming into contact with the high temperature liquid.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a vapor condenser in a vapor phase soldering apparatus of the present invention, FIG. 2 is a perspective view of an external cooler thereof, and FIG. 3 is an enlarged perspective view of a heat pipe portion. FIG. 4 is a sectional view when the present invention is applied to a batch type vapor phase soldering apparatus, and FIG. 5 is a sectional view of an inline type vapor phase soldering apparatus. 14 …… vapor phase, 18,18a …… steam condenser, 31 …… heat pipe, 32 …… heat absorbing part, 3 …… radiating part, 34 …… external cooler, W …… work.

Claims (4)

[Claims] 1. A vapor phase formed inside an apparatus main body is kept in a certain area by a vapor condenser, and latent heat of vaporization of the vapor phase is given to a work carried into the apparatus main body, and this work is reflowed. In the vapor-phase soldering device to be soldered, the vapor condensing device, the heat absorbing portion of the heat pipe is inserted inside the device body, the remaining portion of the heat pipe is drawn out of the device body, this heat A vapor condensing device in a vapor phase soldering device, characterized in that an external cooler is provided at a heat radiating portion located on the external drawing side of the pipe. 2. The vapor condensing device in a vapor phase soldering device according to claim 1, wherein the heat absorbing portion of the heat pipe has a heat absorbing fin. 3. A vapor condensing device in a vapor phase soldering device according to claim 1, wherein the external cooler is a water cooling type cooler. 4. The vapor condensing device in a vapor phase soldering device according to claim 1, wherein the external cooler is temperature-adjustable.