JPS61283458A - Soldering device - Google Patents

Abstract

PURPOSE:To substantially eliminate the need for replenishing a heat transfer liquid and to reduce cost by providing an inside tank formed with the through- holes for conduction of the heat transfer liquid in a heating liquid tank and coolers between the heating liquid tank and the inside tank to recover the used steam. CONSTITUTION:The steam 7a heated by a heater 8 ascends in the inside tank 23 and is cooled by the cooler 28 after melting a solder paste 3 and is thereby condensed. The condensate drops in the form of water drops in the cooler 28 from the space between the cooler and the outside of the inside tank 23. The steam 7a stagnating in the lower part of a belt conveyor 4 in the heating liquid tank 22 is cooled by the cooler 29 and the steam 7a flowing toward a feed port and ejection port is cooled by the coolers 30-33. The steam flows on slopes 25a, 27a and through inclined passes 34, 35 and returns to the tank 22. The steam 7 remaining near the feed port 24 and the ejection port 26 enters the inside of a cover 38 by passing steam guide plates 36, 37 and is recovered by a recovering means.

Description

[Detailed description of the invention] [Industrial application field].

This invention is a paper-phase soldering type solder that collects the vapor of a heat transfer liquid used as a heat medium to melt the solder paste used to attach electronic components to a printed circuit board and prevents it from leaking to the outside. The present invention relates to a mounting device.

[Conventional technology]

FIG. 2 is a side sectional view showing a conventional paper-phase soldering type soldering device, in which 1 is a printed circuit board, 2 is a chip component such as a resistor or capacitor, 3 is a solder paste, and 4 is a soldering device for the printed circuit board 1. A belt conveyor 5 on which the parts are placed and conveyed indicates the entire paper phase soldering type soldering apparatus. 6 is a heated liquid tank of the soldering device 5; 7 is a fluorine-based heat transfer liquid having a boiling point higher than the melting point of the solder paste 3; trademark name) is used. A heater 8 heats the heat transfer liquid 7 and generates heated steam 7a. Reference numeral 9 is an inlet for the printed circuit board 1, 10 is an inlet passage, 11 is an outlet for the soldered printed circuit board 1, 12 is an outlet passage, and 13 is a cooling pipe for condensing the steam 7a. The cooler 14 and 15 are ventilation ports for forcing the uncondensed steam 7a out of the room in order to prevent it from being discharged from the inlet 9 and the outlet 1.

The conventional soldering apparatus is constructed as described above, in which the heat transfer liquid 7 is boiled by the heater 8 to become steam 7a, and the thermal energy possessed by this steam 7a is used as a heat medium to be carried in through the inlet 9 by the belt conveyor 4. The solder paste 3 of the printed circuit board 1 that has been applied is melted, and then the printed circuit board 1 is carried out from the outlet 11, and the solder paste 3 is cooled in the air and solidified, so that the chip component 2 is attached to the printed circuit board. be done. In addition, the steam 7a is supplied to the cooler 1
3, it becomes a liquid and is dropped onto the heat transfer liquid 7 to be collected.

[Problems to be Solved by the Invention] By the way, in the conventional soldering apparatus 5, since the cooler 13 is provided only in the upper part of the heating liquid tank 6, the carry-in side passage 10, and the carry-out side passage 12, the steam 7a There was a problem in that not all of the steam 7a was condensed, and a large amount of remaining steam 7a was directly discharged from the ventilation ports 14, 15, so that the amount recovered was small.

For this reason, if the cooler 13 is also provided below the belt conveyor 4 on the inner peripheral surface of the heating liquid tank 6, the amount of steam 7a recovered will increase; There were problems such as the amount of heat required to melt the solder paste 3 was insufficient due to a decrease in the amount of heat.

Furthermore, since the heat transfer liquid 7 is very expensive, if a large amount of the steam 7a is discharged without being recovered, a large amount of new heat transfer liquid 7 must be replenished, which reduces the manufacturing cost. There were problems such as the increase in the price and the fact that it was uneconomical.

This invention was made to solve the above problems, and makes it possible to recover most of the vapor of the heat transfer liquid without reducing the amount of vapor for melting the solder paste. The purpose of the present invention is to obtain a soldering device that has the following properties.

[Means for solving problems]

The soldering device according to the present invention includes an inner tank having a through hole formed inside the heating liquid tank through which a heat transfer liquid in the heating liquid tank flows; It is equipped with a cooler provided below the belt conveyor on the inner peripheral side.

[Effect]

In this invention, since the cooler is located outside the inner tank,
The amount of steam that melts the solder paste can be maintained without the steam of the heat transfer liquid generated in the inner tank being cooled. Also, the amount of steam flowing into the carry-in side passage and the carry-out side passage is reduced, and is recovered by the heat transfer liquid in the heating liquid tank.

〔Example〕

FIGS. 1(a) and 1(b) show an embodiment of the present invention. FIG. 1(a) is a side sectional view, and FIG. 1(b) is a side sectional view.
It is a sectional view taken along the I-1 line of a). In these figures, the same symbols as in FIG. 2 indicate the same parts, 21 is a soldering device, 22 is a heating liquid tank, 23 is an inner tank provided inside the heating liquid tank 22, and the upper part is a bent part 23a. , 23b are formed, and a through hole 23c is formed below to communicate with the heat transfer liquid 7 in the heating liquid tank 22. Reference numeral 24 indicates an entrance for loading the printed circuit board 1, 25 indicates an inlet passage, 26 an outlet, and 27 an unloading passage. Surfaces 25a, 27
It is formed in a. 28 to 33 are coolers for condensing the steam 7a, and 34.35 are each of the passages 25.27.
These are inclined passages that branch diagonally downward from respective predetermined positions and are connected to the heating liquid tank 22 downward. 36.
37 is the loading port 24. A steam guiding plate for the steam 7a provided at the loading port 26 allows the steam 7a to flow through the loading port 24. ``This is provided to recover the steam 7a discharged from the export port 26 without discharging it to the outside.

Reference numeral 38 denotes a cover provided on the top of the soldering device 21, and is for collecting the steam 7a from the steam guide plates 36, 37.

Furthermore, the cooler 28 is provided above the belt conveyor 4 on the inner periphery of the heated liquid tank 22 . The cooler 29 is located at the inner periphery of the heated liquid tank 22 and below the belt conveyor 4.
The gap between the cooler 29 and the inner tank 23 is narrower than that of the cooler 28. The cooler 30.31 is installed obliquely along the inclined passage 34.35. A cooler 32.33 is provided around the outer periphery of each passage 25.27.

In the soldering apparatus configured as described above, the printed circuit board 1 is conveyed by the belt conveyor 4, and the solder paste 3 is melted by the vapor 7a of the heat transfer liquid 7 heated by the heater 8, and then taken out and cooled. As a result, the chip component 2 is solidified and mounted on the printed circuit board 1 as in the conventional case.

On the other hand, the heated steam 7a rises inside the inner tank 23, melts the solder paste 3, and is then cooled and condensed in the cooler 28, forming water droplets from between the cooler 28 and the outside of the inner tank 23. drip. Further, the steam 7a accumulated below the belt conveyor 4 in the heated liquid tank 22 is cooled by the cooler 29, and the steam 7a accumulated at the lower part of the conveyor belt 4 is cooled by the cooler 29. Steam 7 flowing in the direction of the outlet 11
The liquid a is cooled by the coolers 30, 31, 32, 33, flows along the inclined surfaces 25a, 27a, and returns to the heated liquid tank 22 through the inclined passage 34.35. Furthermore, the steam 7a remaining near the carry-in port 24 and the carry-out port 26 passes through the steam guide plates 36, 37, enters the cover 38, and is recovered by a recovery means (not shown).

〔Effect of the invention〕

As explained above, the present invention provides an inner tank in which a through hole is formed inside the heating liquid tank through which the heat transfer liquid in the heating liquid tank conducts, and a connection between the heating liquid tank and the inner tank. Since it is equipped with a cooler installed below the belt conveyor on the inner circumferential side, the amount of steam of the heat transfer liquid required to melt the solder paste is not reduced, and the Since most of the used steam discharged into the tank can be recovered, there is almost no need to replenish the expensive heat transfer liquid, which is economical and has the advantage of reducing product prices.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) show an embodiment of the present invention. FIG. 1(a) is a side sectional view, and FIG. 1(b) is a side sectional view.
FIG. 2 is a cross-sectional view taken along the line I--I in a), and a side cross-sectional view showing a conventional paper phase soldering type soldering device. In the figure, 1 is a printed circuit board, 2 is a chip component, 3 is a solder paste, 4 is a belt conveyor, 7 is a heat transfer liquid, 7a is steam, 8 is a heater, 21 is a soldering device, 22 is a heating liquid tank, 23 is an inner tank, 24 is a loading port, 25 is a loading side passage,
26 is a carry-out port, 27 is a carry-out side passage, 28 to 33 are coolers, 34.35 is an inclined passage, 36.37 is a steam guide plate, 3
8 is a cover. Figure 1

Claims (1)

[Claims] A belt conveyor conveys a printed circuit board with chip components arranged on solder paste applied in advance, and a heat transfer liquid having a boiling point higher than the melting point of the solder paste is stored, and the heat transfer liquid is heated to generate a heat transfer liquid. In a paper-phase soldering type soldering apparatus, the soldering device is a paper-phase soldering type soldering device comprising a heated liquid tank that melts the solder paste of the printed circuit board with steam, and a cooler installed above the heated liquid tank that cools the vapor. an inner tank in which a through hole is formed through which the heat transfer liquid in the heated liquid tank flows; and a belt conveyor on the inner peripheral side of the heated liquid tank between the heated liquid tank and the inner tank. A soldering device characterized by comprising a cooler provided below.