JP3067213B2 - Vapor phase soldering equipment - Google Patents

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 apparatus for performing soldering utilizing latent heat of vaporization of a saturated vapor phase.

[0003]

2. Description of the Related Art As shown in Japanese Patent Application Laid-Open No. 1-271071, a saturated vapor phase is formed in a steam tank by heating an inert liquid in a liquid tank provided below the steam tank.
A vapor phase soldering apparatus for reflow soldering the work passing through the inside of the saturated vapor phase by the latent heat of vaporization of the saturated vapor phase and filtering the inert liquid in the liquid tank while circulating it through a filtering circuit. There is.

[0004]

When the consumption of the inert liquid in the steam tank progresses and a reduced amount of the inert liquid is supplied to the liquid tank section of the steam tank, a new inert liquid is supplied to the liquid in the steam tank. It is more preferable that the replenishment is performed through a filtering circuit than in the case where the replenishment is performed directly to the tank, in order to prevent a temperature drop of the inert liquid in the liquid tank.

However, since the temperature of the inert liquid in the filtering circuit also drops, if the reduced amount of the inert liquid is quickly (largely) returned to the liquid tank, the large amount of the returning liquid causes the liquid tank to return. There is a problem that the temperature of the inert liquid at the time is also lowered, and the level of the saturated vapor phase temporarily drops.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has been made in view of the above circumstances. Accordingly, it is possible to quickly supply a reduced amount of an inert liquid without affecting the level of a saturated vapor phase of a vapor phase soldering apparatus. The purpose is to do.

[Configuration of the Invention]

[0008]

According to the present invention, a saturated vapor phase 24 is formed in a steam tank 21 by heating an inert liquid 22 in a liquid tank section 21a provided at a lower portion of the steam tank 21. The work 25 passing through the inside of the saturated vapor phase 24 is reflow-soldered by the latent heat of vaporization of the saturated vapor phase 24, and the inert gas 22 in the liquid tank portion 21a is filtered while being circulated by the filtering circuit F. In the phase soldering apparatus, a heating tank 72 is provided in an inert liquid return pipe 74 from the filtering circuit F to the liquid tank section 21a.

[0009]

According to the present invention, when the consumption of the inert liquid 22 in the steam tank 21 progresses and it is necessary to quickly supply the reduced amount of the inert liquid to the liquid tank section 21a, the inert liquid is heated in the heating tank. By heating in 72 and circulating to the liquid tank 21a, even if the reduced amount of the inert liquid is quickly (largely) supplied to the liquid tank 21a, the inert liquid in the liquid tank 21a can be supplied. Temperature of 22 does not decrease.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to an embodiment shown in FIG.

In the main body of the vapor-phase soldering apparatus, an inert liquid (fluorine-based inert solvent) 22 contained in a liquid tank portion 21a of a steam tank 21 is heated by a heater 23 and evaporated to form a vapor. A saturated vapor phase 24 is formed in the tank 21.

The work passing through the inside of the saturated vapor phase 24
The vaporized latent heat of the saturated vapor phase 24 is given to 25, and reflow soldering is performed.

A cooling coil 26 is provided on a work carry-in side and a work carry-out side of the steam tank 21, a cooling water pipe 27 is provided, and the steam tank 21 is condensed by the cooling coil 26.
Steam leakage from inside to outside is prevented.

Further, a work carry-in portion and a work carry-out portion of the steam tank 21 are connected to a liquid recovery unit via an exhaust pipe 28.
The vapor or mist (growth of vapor particles) which is communicated with the liquid recovery unit 29 by the blower B and is forcibly sucked by the blower B is liquefied by an internal collision plate, a cooling coil, and the like, and After passing through 30, it is collected in the steam tank 21.

A filtering circuit F is connected to the liquid tank portion 21a of the steam tank 21. The filtering circuit F will be described.

An inert liquid outlet pipe from the bottom of the steam tank 21
A liquid temperature lowering tank 31 passes through a Y-strainer 32, a liquid discharge electric valve 33, and a safety electric valve 34.
The top of 35 is connected.

A cooling coil 36 is provided inside the liquid temperature drop tank 35.
Are provided, and a stirring blade 37 rotated by a motor is provided. The motor-operated valve 33 is provided with a bypass pipe 38, and the pipe 38 is provided with a manual adjustment valve 39.

A pipe 41 drawn out from the lower part of the liquid temperature drop tank 35 is provided with a drain shut-off valve 43 through a drain pipe 42, an electric stop valve 44, and a heat-resistant pump 45. Is provided.

An inert liquid return pipe 46 and a filtering pipe 47 are branched from the pipe 41, and the pipes 46, 47 are provided with solenoid valves 48, 49, respectively.

The return pipe 46 is a liquid tank part of the steam tank 21.
21a, and the filtering line 47 is
It is connected to the upper part of the liquid temperature drop tank 35 through the cartridge filters 51 and 52. An inert liquid replenishing tank 53 is connected to the upper part of the liquid temperature lowering tank 35 via a valve 54.

The liquid tank of the steam tank 21 is provided inside the liquid temperature drop tank 35.
An inert liquid (fluorinated inert solvent) 22a, which is the same as the inert liquid 22 contained in the liquid 21a, is preliminarily stored in an equal amount, and is cooled to a temperature at which the heat resistance of the filters 51 and 52 is maintained by the cooling coil 36. It is cooled and its temperature is made uniform by the stirring blade 37.

A liquid level detecting device is provided in the inert liquid extracting pipe 31 and the liquid temperature lowering tank 35 drawn out from the liquid tank section 21a.
61 and 62 are connected via a tube 63.

The liquid level detectors 61 and 62 have a heat-resistant glass transparent pipe 64 serving as a communication pipe between the liquid tank section 21a and the liquid temperature drop tank 35, respectively. A multi-stage photosensor 65 is provided to detect the presence or absence of the inert liquids 22 and 22a by the installed light emitter and light receiver to detect the liquid level.

The pipe 41 is connected to the upper part of the heating tank 72 via a solenoid valve 71 from a branch point with the pipe 46. The heating tank 72 contains an inert liquid 22b circulated through the liquid tank section 21a.
Is provided, and is connected to the steam tank 21 via an inert liquid return line 74.

Next, the operation of this embodiment will be described.

During operation, the valves 33, 34, 44, 48,
Open 49 and close valves 39, 43, 54, 71.

During this operation, the high temperature inert liquid in the steam tank 21
22 is taken out little by little into the liquid temperature drop tank 35, where 90
The temperature is lowered below ℃.

A part of the low-temperature inert liquid 22a is supplied to a pump
The pressure is fed to the filtering line 47 by 45, filtered by the cartridge type filters 51 and 52 provided in the filtering line 47, and circulated to the liquid temperature lowering tank 35.

Therefore, the inert liquid 22a inside the liquid temperature lowering tank 35 is always kept at a low temperature and kept clean.

At the same time, the inert liquid 22
a is circulated to the steam tank 21 by the pump 45 via the inert liquid return pipe 46 at a flow rate equal to the removal flow rate from the steam tank 21.

As described above, the inert liquid 22 in the steam tank 21 is taken out little by little and enters the liquid temperature lowering tank 35, where it is mixed with the clean low-temperature inert liquid 22a in the tank to reduce the pollution degree. You.

When the consumption of the inert liquid in the steam tank 21 progresses and the inert liquid 22 is supplied to the steam tank 21, the supply tank 53 is used.
Open the valve 54, supply the new inert liquid from the replenishing tank 53 to the liquid temperature drop tank 35,
Refill 21 quickly.

In this case, when the temperature of the inert liquid 22 in the liquid tank section 21a decreases due to the quick supply of the inert liquid to the liquid tank section 21a, the level of the saturated vapor phase 24 also decreases. Solenoid valve when quickly replenishing
71 is opened and the electromagnetic valve 48 is closed, and the inert liquid return line is switched from the inert liquid return line 46 to the heating tank 72 and the inert liquid return line 74.

The inert liquid 22b supplied from the solenoid valve 71 to the heating tank 72 is heated by the heater 73 in the heating tank 72 and then passed through the vapor tank 21 through the inert liquid return pipe 74 to the liquid tank section 21.
Therefore, even if the reduced amount of the inert liquid is quickly (largely) supplied to the liquid tank section 21a, the temperature of the inert liquid 22 in the liquid tank section 21a does not decrease. As a result, the level of the saturated vapor phase 24 does not decrease.

[0035]

According to the present invention, since the heating tank is provided in the inert liquid return line from the filtering circuit to the liquid tank section of the steam tank, the heating tank heats the inert liquid to reduce the amount of reduction. Inert liquid can be quickly (largely) replenished to the liquid tank, and the inert liquid can be reduced quickly in the liquid tank. In addition, the temperature of the inert liquid in the liquid tank can be prevented from lowering, and the liquid can be saturated. The level of the vapor phase can be prevented from lowering.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a vapor phase soldering apparatus showing one embodiment of the present invention.

[Explanation of symbols]

 21 Steam tank 21a Liquid tank section 22 Inert liquid 24 Saturated vapor phase 25 Work 72 Heating tank 74 Inert liquid return line F Filtering circuit

Continuation of front page (56) References JP-A-2-15873 (JP, A) JP-A-1-271071 (JP, A) JP-A-64-44273 (JP, A) JP-A-63-123565 (JP) JP-A-63-90361 (JP, A) JP-A-1-197060 (JP, A) JP-A-1-104468 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B23K 1/015 H05K 3/34 507

Claims (1)

(57) [Claims] 1. A saturated vapor phase is formed in a steam tank by heating an inert liquid in a liquid tank provided at a lower portion of the steam tank, and a work passing through the inside of the saturated vapor phase is saturated. Reflow soldering by the latent heat of vaporization of the vapor phase,
In a vapor phase soldering apparatus for filtering the inert liquid in the liquid tank portion while circulating the same through a filtering circuit, a heating tank is provided in an inert liquid return line from the filtering circuit to the liquid tank portion. Vapor-phase soldering equipment.