JPH0354027B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an article fusion bonding apparatus that melts a bonding agent for bonding articles by using vapor of a heated liquid heat transfer liquid as a heat medium. It is.

[Conventional technology]

In general, to bond items, one can use electrical heating such as with a soldering iron, use a solid, liquid, or gaseous heat transfer material, or transfer thermal energy to a bonding agent using a light beam with thermal energy. The bonding agent is heated to become a fluid, and the heat retained in the bonding agent raises the bonding area of the articles to an appropriate temperature for bonding, and then the articles are cooled and bonded.

Here, in the above-mentioned joining method, FIG. 3 is a side sectional view showing a device used in the conventional article fusion method disclosed in Japanese Patent Publication No. 53-40934, in which 1 is a container; 2 is a heating coil, 3 is a cooling coil, and 4 is a fluorine-based heat transfer liquid, which is fluorinated polyoxypropylene sold by E.I. DuPont under the name Freon E5. The heat transfer liquid 4 is placed in the container 1 to the position shown in the figure, heated by the heating coil 2 to its boiling point, and maintained at that temperature. Boiling heat transfer liquid 4
The steam generated by heating is filled up to the horizontal surface of the cooling coil 3 as shown by the dashed line 5, and the steam is condensed at the position of the cooling coil 3 and returns to the lower part of the container 1 as a liquid. Since this heated steam has a higher density than air, the cooling coil 3 prevents the upper surface of the steam from being higher than the horizontal plane indicated by the dashed-dotted line 5, thus preventing it from leaking out of the container 1. . 6 is a printed circuit board, 7 is a holder for mounting and holding the printed circuit board 6, 8 is a chip component such as an electronic component to be joined to the printed circuit board 6, and 9 is a powdered solder paste mixed therein. Paste solder, which is a glue-like bonding agent, is applied in advance to the upper surface of the printed circuit board 6 and the lower surface of the chip component 8. Note that the heat transfer liquid 4 used has a boiling point equal to the melting point of the solder paste 9.

In this way, the heat transfer liquid 4 boils and becomes steam, and the thermal energy of this steam is used as a heat medium to melt the paste solder 9.Then, the holder 7 is pulled upward and placed in the cooling coil 3 and the air. The printed circuit board 6 and the chip component 8 are bonded by cooling and solidifying.

[Problem that the invention seeks to solve]

By the way, in the conventional method for fusing products, the vapor of the heat transfer liquid 4 is used in a stagnant state, so that no pressure is built up on the vapor, so a large amount of vapor is released by melting the paste solder 9. However, there was a problem in that the efficiency of heat energy use was poor and the economic loss was large.

Furthermore, even if the vapor of the heat transfer liquid 4 contains impurities, there is no filter to remove them, so the heat transfer liquid 4 may become contaminated during repeated evaporation and condensation, and the vapor of the heat transfer liquid 4 may contain fluorine-based substances. Since it contains toxic gases, there was a problem in that the indoor air was polluted by the exhaust of these toxic gases.

This invention was made in order to solve the above-mentioned problems, and the heat transfer liquid can be used repeatedly in a clean state at all times, and the exhaust port through which the vapor of the heat transfer liquid is discharged is made smaller so that the vapor can be discharged from the opening. Reduce the outflow of
The purpose is to prevent it from being discharged indoors.

[Means for solving problems]

The fusion bonding device for articles according to the present invention includes a heat transfer liquid having a boiling point substantially the same as the melting point of the bonding agent;
A heating liquid tank that heats the heat transfer liquid to generate steam, a processing tank that uses the steam in the heating liquid tank to melt the bonding agent, and the steam in the heating liquid tank is pressurized and ejected into the processing tank. An air supply means, a cooling coil that cools the steam in the processing tank and condenses it into a heat transfer liquid, a filter that filters the heat transfer liquid in the processing tank, and heats the heat transfer liquid filtered by the filter. It consists of a reflux means for circulating the liquid back into the liquid tank, and an exhaust port for discharging steam leaked to the outside of the cooling coil of the processing tank from the end of the processing tank.

[Effect]

In this invention, the thermal energy contained in the vapor of the pressurized heat transfer liquid acts as a heat medium to melt the bonding agent, and the condensed heat transfer liquid is filtered to remove impurities in the heat transfer liquid. The steam leaking to the outside of the processing tank is exhausted from the exhaust port to prevent the room from being filled with steam.

〔Example〕

FIG. 1 is a configuration diagram showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line II in FIG. 1. In these figures, 11 is a heating liquid tank, and 12 is a heat transfer liquid contained in the heating liquid tank 11. This heat transfer liquid 12 is, for example, Fluorinert (Sumitomo 3M Ltd.), which is a fluorine-based inert liquid. trademark name). 13 is a heater that heats the heat transfer liquid 12; 14 is an air supply pipe that supplies steam 12a of the heat transfer liquid 12 heated by the heater 13 to a processing tank 19 (to be described later); 15 is an air supply pipe that supplies the steam 12
16 is a nozzle for spouting the pressurized steam 12a into the processing tank 19; 17 is a printed circuit board as a first article;
8 is the printed circuit board 1 using the paste solder 9.
The solder paste 9 is melted by pressurized steam 12a in the processing tank 19 to form a printed circuit board 17,
The electronic components 18 are bonded. 20 is the processing tank 1
9 is a cooling coil for solidifying the steam 12a in 9; 21 is a belt conveyor for conveying the printed circuit board 17; 22 is an inlet port through which the printed circuit board 17 on the belt conveyor 21 enters the processing tank 19;
Reference numeral 3 denotes an outlet through which the printed circuit board 17 on the belt conveyor 21 that has been bonded is sent out, and 24 denotes a vapor 1 that leaks from the cooling coil 20 and is not cooled.
At the exhaust port 2a, the steam 12a is forcibly discharged to the outside in order to prevent it from being discharged from the outlet 23. 25 is a heating liquid tank 1 in which the heat transfer liquid 12 which has been condensed from the vapor 12a has become liquid;
1, a reflux pipe 26 is a reflux pump, and 27 is a filter provided in the reflux pipe 25 to filter out impurities in the heat transfer liquid 12.

Note that the heat transfer liquid 12 used has a boiling point approximately the same as the melting point of the solder paste 9.

As mentioned above, the printed circuit board 17 and electronic components 18
is coated with paste solder 9 and temporarily fixed at the joining position. Next, the heat transfer liquid 12 is heated and boiled by the heater 13 to generate steam 12a. Next, the steam 12 is pumped by the rotation of the pump 15.
The gas a is pressurized and enters the air supply pipe 14 and is ejected from the nozzle 16 into the processing tank 19. At this time, the printed circuit board 17 placed on the belt conveyor 21 is transported and enters the processing tank 19 through the inlet 22 . Then, pressurized steam 1 is ejected from the nozzle 16.
The solder paste 9 is heated in a short time by the thermal energy of the steam 12a, and a large amount of thermal energy of the steam 12a is transferred to melt the solder paste 9. Next, when the printed circuit board 17 on the belt conveyor 21 is further moved and taken out from the outlet 23, the paste solder 9 is cooled and solidified.

Next, the steam 12a is cooled by the cooling coil 20, so that it condenses and drips, becoming the heat transfer liquid 12 and stored under the processing tank 19. Next, the heat transfer liquid 12 flows through the reflux pipe 25 by the rotation of the pump 26.
impurities are filtered out by a filter 27 and refluxed into the heated liquid tank 11.

In addition, the steam 12a that is not condensed in the cooling coil 20 of the processing tank 19 and leaks to the outside of the cooling coil 20 is forcibly discharged to the outside from the exhaust port 24, and is not discharged indoors. There is.

〔Effect of the invention〕

As explained above, the present invention uses a heat transfer liquid having a boiling point that is almost the same as the melting point of the bonding agent, a heating liquid tank that heats the heat transfer liquid to generate steam, and a heating liquid tank that generates steam by heating the heat transfer liquid and generating steam. A processing tank for melting the bonding agent, an air supply means for pressurizing and blowing out steam in the heating liquid tank into the processing tank, and a cooling coil for cooling the vapor in the processing tank and condensing it into a heat transfer liquid. , a filter for filtering the heat transfer liquid in the processing tank, a reflux means for returning the heat transfer liquid filtered by the filter to the heating liquid tank, and a reflux means for returning the heat transfer liquid filtered by the filter to the heating liquid tank; Since the structure consists of an exhaust port for discharging from the end, the thermal energy of the steam is efficiently used, and the bonding agent is melted in a short time, making it economical. Since the liquid is used in a clean state, the quality of joining products is improved, and there is no leakage of steam to contaminate the indoor air with toxic gases, which improves the environment in the workplace. There is.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line II in FIG. 1, and FIG. 3 is a side sectional view showing an example of a conventional device. In the figure, 9 is paste solder, 11 is a heated liquid tank,
12 is a heat transfer liquid, 12a is steam, 13 is a heater,
14 is an air supply pipe, 15 and 26 are pumps, 16 is a nozzle, 17 is a printed circuit board, 18 is an electronic component, 19
20 is a processing tank, 20 is a cooling coil, 21 is a belt conveyor, 22 is an inlet, 23 is an outlet, 24 is an exhaust port, 25 is a reflux pipe, and 27 is a filter.

Claims (1)

[Claims] 1. A bonding agent applied in advance to the bonding surface of the first article and the bonding surface of the second article that is placed on a moving mechanism and transported and joins the first article and the second article. An article that is heated together with the first article and the second article to melt the bonding agent, and solidifies the melted bonding agent to join the first article and the second article. In the fusion bonding apparatus, a heat transfer liquid having a boiling point approximately the same as the melting point of the bonding agent, a heating liquid tank for heating the heat transfer liquid to generate steam, and a heating liquid tank for heating the heat transfer liquid to generate steam; a processing tank for melting the agent; an air supply means for pressurizing and spouting the vapor in the heated liquid tank into the processing tank; and cooling the vapor in the processing tank and condensing it into the heat transfer liquid. a filter for filtering the heat transfer liquid in the processing tank; a reflux means for returning the heat transfer liquid filtered by the filter to the heating liquid tank; and a cooling coil for the processing tank. A fusion bonding apparatus for articles, comprising an exhaust port for discharging steam leaked to the outside from an end of the processing tank.