JPH04270064A - Soldering apparatus - Google Patents

Abstract

PURPOSE:To provide a VPS soldering apparatus having structure using single heating solvent and preventing the solvent from disappearing with gasifying. CONSTITUTION:A heating chamber 11 constituted so as to mount a material to be treated on a carrier 1, pass this through a first cooling chamber 10 having inlet with a first shutter 13 and communicating with a heating chamber 11 with a second shutter 14, and communicate with a second cooling chamber 12 with the second shutter 14 and a third shutter 15, provides a heater 4 and carbon fluoride 5 at the bottom part. After executing the soldering by hanging down the material to be treated mounted on the carrier 1 into vapor of the solvent 5 formed with heating of a heater 4, the carrier 1 is pulled up and conveyed to the second cooling chamber 12 and the cooled material to be treated is carried out to the outer part from a fourth shutter 16.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus configuration for soldering (hereinafter referred to as soldering) a workpiece by the VPS method.

Commonly used soldering devices include jet soldering devices used for mounting components on printed wiring boards, infrared heating devices and hot soldering devices used for mounting components on hybrid IC boards. There are plate heating devices, etc.

[0003] However, these devices cannot heat the object to be processed to a uniform temperature. On the other hand, the VPS (Vapor Phase Solder
ing) The device is a soldering method that allows heating at a uniform temperature, and uses a heating solvent such as fluorocarbon that is chemically stable at high temperatures, has little reactivity, and does not easily oxidize the object to be processed. This is a method in which the workpiece to be soldered is immersed in a high-temperature atmosphere created by this steam.

That is, the method utilizes the fact that a solvent vapor layer at a constant temperature is formed within a heating chamber by heating the solvent to a temperature higher than its boiling point. Therefore, by selecting and using a solvent with the required boiling point, it is possible to perform soldering with high temperature accuracy and high reliability.

For example, tin (Sn) 6 has a melting point of 183°C.
0%, lead (Pb) 40% solder (hereinafter abbreviated as 6.4 solder)
To perform soldering using VPS, a heated solvent with a boiling point of about 200° C. is used.

[0006]

2. Description of the Related Art There are two types of VPS methods: an in-line type using a conveyor mechanism, and a batch type.

FIG. 2 is a sectional view showing the configuration of a conventional batch type soldering device, and the case where 6/4 solder is used will be described below. A conventional soldering apparatus is comprised of an input/output area 2 and a processing area 3, in which a workpiece is loaded onto a carrier 1, inserted into the carrier 1, and taken out.

Here, a heater 4 is provided at the bottom of the apparatus in which the processing region 3 is located, and a heating solvent 5 having a boiling point of 215° C. and a heating solvent 5 having a boiling point of 47° C., for example, are placed in a container constituting the processing region.
．． A cooling solvent at 6°C is included.

[0009] When the heater 4 is heated to 215° C. or higher, all of the cooling solvent evaporates and the heating solvent also begins to boil, resulting in a heating zone consisting of the vapor of the heating solvent inside the container. 6 and above it a cooling zone 7 consisting of vapor of the cooling solvent.

On the other hand, since the upper part of the apparatus is at room temperature, the heated solvent 5 is confined in the heating zone 6, liquefies when it hits the cooling zone 7, and falls like rain. The liquid is then reheated in the liquid reservoir and vaporized repeatedly.

Further, the cooling solvent liquefies upon hitting the shutter 8, flows down along the side wall of the container, and then evaporates again and fills the cooling zone 7 to form vapor. To perform soldering using such a soldering device, the workpiece to be processed with solder is placed on the carrier 1 in the entry/exit area 2 and carried into the device, and then the shutter 8 is opened to reach the heating zone 6. Drop down, heat, and perform soldering.

Next, after soldering is completed, carrier 1
is gradually cooled to 70° C. by increasing the temperature to cooling zone 7. Next, after slow cooling, carrier 1 is transferred to entry/exit area 2.
The object to be processed is taken out.

[0013] When such a method is adopted, consumption of an expensive heating solvent is reduced, and since slow cooling is performed in the cooling zone 7, soldering can be performed without oxidizing the workpiece.

However, in this method, the cooling zone 7
Although it is unavoidable to pump out the cooling solvent in space, this cooling solvent is a chlorofluorocarbon commonly known as fluorocarbon, and it is necessary to refrain from using it because it destroys the ozone layer in space.

[0015]

[Problems to be Solved by the Invention] The VPS method is a method of soldering using a combination of a chemically inert heating solvent and a cooling solvent, and is an excellent method that allows soldering with high temperature accuracy.

However, in the present situation where the use of cooling solvents is inappropriate, the problem is to put into practical use a soldering device that uses only heating solvents and consumes less.

[0017]

[Means for Solving the Problems] The above problem is such that an apparatus for soldering workpieces by the VPS method is connected to an inlet through a first shutter and to a heating chamber through a second shutter, and also connects to an air blower and a water cooling chamber. A first cooling chamber includes a mechanism, a track path, etc., and means for transporting the workpiece from the entrance onto a transport carrier to the heating chamber;
The second shutter communicates with the first cooling chamber, and the third shutter communicates with the second cooling chamber, and a heating chamber is configured with a heater and a heating solvent at the bottom, and the heater heats the heating chamber. means for suspending the workpiece placed on the conveyance carrier into the solvent vapor formed by the process and performing soldering, and then pulling up the conveyance carrier and conveying it to a second cooling chamber; A shutter connects the heating chamber, and a fourth shutter connects the outlet to the air blower.
A soldering apparatus characterized in that a second cooling chamber is configured with a water cooling mechanism, a track path, etc., and a means for cooling and taking out a workpiece transported by a transport carrier. It can be solved by using

[0018]

[Function] The present invention performs soldering using only a heating solvent, since cooling solvents made of low boiling point fluorocarbons (fluorocarbons) can no longer be used in conventional batch-type soldering equipment. Thorough solvent liquefaction treatment and solvent reduction are performed as a method to prevent consumption of high-boiling point solvents.

The low boiling point fluorinated carbon that is said to destroy the ozone layer is a volatile chlorine-substituted fluorinated carbon called chlorofluorocarbon, such as 1,1,
2-Trichloro-1,2,2-trifluoroethane (C
Cl2F-CClF2, boiling point 47.6℃), 1,1
, 2,2-tetrachloro-1,2-difluoroethane (CCl2F-CCl2F, boiling point 92.8°C), etc. These carbon fluorides easily evaporate and are chemically stable, so they reach the stratosphere. It decomposes under ultraviolet light and generates chlorine, which destroys ozone (O3).

Therefore, in the present invention, VPS is performed using only high boiling point hydrogen fluoride without using such low boiling point carbon fluoride. In other words, the features of the present invention are: (1) An in-line type with separate inlet and outlet for the material to be processed; (2)
Since the solvent is consumed by being carried out by adhering to the object to be treated and by the diffusion of solvent vapor, shutters were installed in the heating and cooling chambers to prevent diffusion. ■ A trap path was provided to return the high boiling point solvent accumulated in the cooling chamber to the heating chamber. It is.

By adopting such a structure, efficient soldering can be performed using only a single solvent.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional view showing the configuration of a soldering apparatus according to the present invention, which consists of three chambers: a first cooling chamber 10, a heating chamber 11, and a second cooling chamber 12. As shown in the figure, there are a first shutter 13, a second shutter 14, a third shutter 15, and a fourth shutter 16 between the rooms and the exit, and are configured to open and close automatically.

[0023] Here, a heater 4 is provided at the bottom of the heating chamber 11 as in the conventional case, and by heating the heated solvent 5 in the chamber, a heating zone 17 made of saturated vapor of the solvent is created. A cooling zone 18 is formed above this, although the boundary is not clear, in which the solvent vapor concentration gradually decreases.

Furthermore, when the second shutter 14 and the third shutter 15 are opened and closed, the heated solvent vapor is removed from the first cooling chamber 10.
Although some degree of steam transfer to the second cooling chamber 12 is unavoidable, the side wall of the cooling chamber has a water-cooled structure, and the steam is stirred by an air blow (not shown), so it easily liquefies and liquefies. The solvent is configured to return to the heating chamber 11 via track paths 19 and 20.

Now, in order to perform soldering using such an apparatus, the workpiece to be processed with solder balls and solder paste attached is loaded onto the carrier 1, and the object is sequentially conveyed through the apparatus according to a predetermined program. The configuration is such that soldering can be performed.

That is, the carrier 1 is in the first cooling chamber 10
When it approaches, the first shutter 13 opens for a while and the carrier 1 enters the first cooling chamber 10, and then when it rises and approaches the second shutter 14, this shutter 14 opens for a while and the carrier 1 enters the heating chamber 11. .

Next, the carrier 1 is lowered down to the heating zone 17 and held there for a while to perform soldering. Next, the carrier 1 goes up to the cooling zone 18 and is cooled. Next, when the carrier 1 is transported to the position of the third shutter 15, the third shutter 15 opens and moves to the second cooling chamber 12, and then When the carrier 1 descends inside the room and comes in front of the fourth shutter 16, the fourth shutter 16 opens and the carrier 1 is carried out of the apparatus.

Note that the first cooling chamber 10 and the second cooling chamber 1
The heated solvent 5 liquefied in step 2 passes through the trap path 19, 2.
0 returns to the heating chamber 11, but this trap path also effectively acts as a pressure leak in the heating chamber 11.

[0029]

[Effects of the Invention] By using the soldering device according to the present invention, it is possible to use only a heated solvent and to suppress its disappearance outside the device as much as possible, and it is possible to perform soldering with high temperature accuracy using the VPS method. It has become possible.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of a soldering device according to the present invention.

FIG. 2 is a sectional view showing the configuration of a conventional soldering device.

[Explanation of symbols]

1　　　　　　　　　　Career 4 Heater 5 Heating solvent 6,17 Heating zone 7,18 Cooling zone 10 First cooling chamber 11 Heating chamber 12 Second cooling room 13 First shutter 14 Second shutter 15 Third shutter 16 Fourth shutter 19,20 Trap pass

Claims (1)

[Claims] Claim 1: An apparatus for soldering workpieces by the VPS method, which connects an inlet through a first shutter (13) and a heating chamber (11) through a second shutter (14). A cooling chamber (10) is configured, and includes a means for transporting the object to be processed on a carrier (1) from the entrance to a heating chamber (11), and a second shutter (14) to transport the object to the first cooling chamber (10). ), and is connected to the second cooling chamber (12) by a third shutter (15), and has a heater (4) and a fluorocarbon solvent (5) at the bottom to form a heating chamber (11). After soldering is performed by hanging the workpiece placed on the carrier (1) into the vapor of the solvent (5) formed by heating the heater (4), the carrier (1) ) to a second cooling chamber (12); and a heating chamber (11) by a third shutter (15);
In addition, a fourth shutter (16) connects the exit to the second
1. A soldering apparatus comprising: a cooling chamber (12), and means for cooling and taking out a workpiece transported by a carrier (1).