JPH0577037A - Gas phase type soldering apparatus - Google Patents

Abstract

PURPOSE:To efficiently recover grown mists from the vapor phase of fluorine base inert solvent for executing reflow soldering to a substrate. CONSTITUTION:At the inside of a carrying inlet 18 for substrate and at the inside of a carrying outlet 19 for substrate in a vaporizing vessel 14, a mist dropping holes 31 having large diameter and deep depth are arranged. In the inner wall of each mist dropping hole 31, a cooling coil 32 for promoting the growth of the mist particles is arranged. Suction holes in a blower 34 are connected with the lower parts of the mist dropping holes 31, and a separator 35 and a cyclone 36 are connected with a discharging port in this blower 34. The solvent mists growing the particle diameter in the vapor phase 16 are surely sucked into the mist dropping hole 51 on the way of shifting toward the carry inlet 18 for substrate and the carry outlet 19 for substrate. The solvent flowed down to the mist dropping holes 31 and the lower part of the separator 35 is once stored into a solvent tank 41 and circulated to a solvent incorporating part 43 in the vaporizing vessel 14 through a pump 42.

Description

Detailed Description of the Invention

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor phase soldering device.

[0003]

2. Description of the Related Art As shown in FIG. 2, a conventional vapor-phase soldering apparatus has a substrate 12 conveyed by a conveyor 11.
Is first preheated by an external preheater 13 and then carried into the steam tank 14 and then passed through the heat retaining heater 15 and then to the steam tank 14
It is carried into the saturated vapor phase 16 formed inside, and the cream solder between the substrate 12 and the components mounted on the substrate is melted (reflowed) by the latent heat of vaporization that the saturated vapor phase 16 has. The saturated vapor phase 16 is formed by heating a fluorine-based inert solvent (trade name: Fluorinert) 16a contained in the bottom of the vapor tank with a heater 17.

Since the fluorine-based inert solvent 16a is expensive, the solvent mist suspended in the vapor tank 14 (having a larger particle size than the vapor phase) is the substrate inlet 18 and the substrate outlet 19. The steam tank mist is sucked into the mist suction recovery section 23 by the suction force of the blower 22 from the mist suction port 21 provided inside the substrate carry-in port 18 and the substrate carry-out port 19 so as not to flow out from the outside. The recovery unit 23 separates the solvent mist from the air to recover the solvent 16a. 24 is a cooling coil.

[0005]

However, all the mists cannot be efficiently collected with a small suction port such as the mist suction port 21, and the upper side of the mist suction port 21 is jumped over to the substrate loading port 18 or the substrate. There is a solvent mist flowing out from the carry-out port 19. If this type of solvent mist comes into direct contact with the high temperature heater 25 provided inside the preheater 13, there is a possibility that toxic gas (perfluoroisobutylene) will be generated.

In order to prevent this, the preheater 13 is conventionally provided apart from the substrate carry-in port 18 of the steam tank 14 as shown in FIG. 2. Then, the substrate 12 heated to a predetermined temperature by the preheater 13 is provided. However, there is a problem that the temperature drop occurs before it is loaded into the heat retention heater 15, and the temperature drop cannot be recovered by the heat retention heater 15, so that the desired substrate temperature profile cannot be obtained by heating from preheating to reflow. ..

The present invention has been made in view of the above point, and by improving the mist recovery efficiency, it is possible to integrate the preheater and the steam tank, and the substrate temperature profile from preheating to reflow can be obtained. It is intended to be ideal.

[Configuration of Invention]

[0009]

The present invention provides a preheater 13
The substrate 12 preheated by the
In the vapor-phase soldering device that is carried into the steam tank from the, and reflow soldering by the latent heat of vaporization of the saturated vapor phase 16 formed in this steam tank, and carried out from the substrate outlet 19 of the steam tank 14 to the outside. The substrate loading port 18 in the steam tank 14
A large-diameter and large-depth mist drop hole 31 is provided inside the board and the substrate outlet 19, respectively.
A mist suction / collection unit 33 is connected to the lower part of 31 and the preheater 13 is integrally installed outside the substrate carry-in port 18 in the vapor phase soldering apparatus.

[0010]

According to the present invention, since a sufficient suction air volume can be obtained in the large-diameter mist drop hole 31, even if the mist grown from the vapor phase 16 moves toward the substrate carry-in port 18 and the substrate carry-out port 19, , The mist is surely sucked into the mist drop hole 31, and the mist sucked into the deep mist drop hole 31 has a downward direction, so that the mist does not re-float,
Since the preheater 13 is efficiently collected, even if the preheater 13 is integrated with the substrate carry-in port 18 of the steam tank 14, there is no possibility that the mist will react with the high temperature preheater 13 outside the steam tank to generate toxic gas.

[0011]

The present invention will be described in detail below with reference to FIG. The same parts as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted.

Inside the substrate carry-in port 18 and inside the substrate carry-out port 19 in the vapor tank 14, a large-diameter and deep-depth mist drop hole 31 for dropping the solvent mist (those in which the vapor phase particle size has grown) is dropped. Are provided over the entire width of the steam tank 14 (direction perpendicular to the paper surface).
The inner wall of 31 has a cooling coil that promotes the growth of mist particles.
32 are provided.

A mist suction / collection section 33 is connected to a lower portion of each mist drop hole 31. This mist suction collection section
The 33 includes a blower 34, a separator 35, and a cyclone 36. Inside the separator 35, collision plates 37 are provided alternately, and a cooling coil 38 that promotes growth of mist particles is provided.

Further, a solvent tank 41 for temporarily containing the liquefied fluorine-based inert solvent 16a is connected to the lower ends of the separator 35 and the mist drop hole 31, and the steam tank 14 is pumped from the solvent tank 41 by the pump 42. A solvent circulation system that circulates the solvent 16a is provided in the solvent storage portion 43.

Further, a preheater 13 is integrally installed outside the substrate carry-in port 18 without opening a gap.

Next, the operation of this embodiment will be described. The substrate 12 preheated by the preheater 13 is carried into the steam tank 14 from the substrate carry-in port 18 of the steam tank 14 and formed in the steam tank 14. The saturated vapor phase 16 is subjected to reflow soldering by the latent heat of vaporization and is carried out from the substrate carry-out port 19 of the steam tank 14 to the outside.

Since there is no gap between the preheater 13 and the steam tank 14, the substrate 12 which has been heated to a predetermined temperature by the preheater 13 is immediately transferred between the substrate carry-in port 18 and the heat retaining heater 15 in the steam tank 14. It is carried in and does not cause much temperature drop. Therefore, a desired substrate temperature profile can be obtained by heating from preheating by the preheater 13 to reflow by the saturated vapor phase 16.

A part of the mist grown from the vapor phase 16 moves toward the substrate carry-in port 18 and the substrate carry-out port 19 of the steam tank 14, and is attracted to the large-diameter mist drop hole 31 on the way.

In this large-diameter mist drop hole 31, since the blower 34 of the mist suction / collection section 33 can obtain a sufficient amount of suction air even if it is gentle, the solvent mist is surely sucked into the mist drop hole 31 and has a large depth. Since the mist sucked into the mist drop hole 31 has a downward directionality, the mist does not re-float, and the more it moves downward, the stronger the cooling effect of the cooling coil 32 is, so that the mist is efficiently recovered.

The mist that has not liquefied in the mist drop hole 31 is sent from the mist drop hole 31 to the separator 35 by the blower 34 of the mist suction / collection section 33, and the collision plate 37 separates the mist having inertial force from the air. And is completely separated by the cyclone 36.

The solvent 16a obtained in the mist drop hole 31 and the separator 35 is temporarily stored in the solvent tank 41 and then circulated by the pump 42 into the solvent storage portion 43 of the steam tank 14.

[0022]

EFFECTS OF THE INVENTION According to the present invention, since there is a mist drop hole having a large diameter, it is possible to obtain a sufficiently large amount of air when sucking and collecting the mist, and the mist that is about to flow out to the outside can be taken out of this large diameter. The mist can be reliably sucked into the mist drop hole, and the mist sucked into the mist drop hole with a large depth can be given a downward direction to prevent re-floating, thereby improving the mist recovery efficiency. Therefore, there is no risk that this type of mist will react with the high temperature preheater outside the steam tank to generate toxic gas, so the preheater can be integrated with the substrate inlet of the steam tank, and the substrate temperature profile from preheating to reflow can be increased. Can be ideal.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a vapor phase soldering device showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a conventional vapor phase soldering device.

[Explanation of symbols]

 12 Substrate 13 Preheater 14 Steam tank 16 Saturated vapor phase 18 Substrate carry-in port 19 Substrate carry-out port 31 Mist drop hole 33 Mist suction recovery section

Claims (1)

[Claims] 1. A substrate preheated by a preheater,
Vapor-phase solder that is carried into the steam tank from the board inlet of the steam tank, reflow-soldered by the latent heat of vaporization of the saturated vapor phase formed in this steam tank, and carried out from the board outlet of the steam tank to the outside. In the attachment device, a large-diameter and large-depth mist drop hole is provided inside the substrate carry-in port and inside the substrate carry-out port in the steam tank, and a mist suction / collection unit is connected to the lower part of the mist drop hole to connect the substrate carry-in device. A vapor-phase soldering device, wherein the preheater is integrally installed outside the mouth.