JPH077036Y2 - Preheater for soldering - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is a soldering auxiliary for heating a substrate coated with flux to facilitate soldering immediately before the soldering process of a printed substrate. Regarding the heater.

(Prior Art) Conventionally, a preheater incorporated in an automatic soldering device for a printed circuit board has a structure in which a heater for heat radiation is arranged in a box-shaped heater body having an upper opening. It was used. As the radiant heater, one having a meandering curved shape was usually used.

However, since such a preheater heats the printed circuit board only by radiant heat from the heater,
There was a certain limit in improving the heating effect.

Therefore, in recent years, in addition to the above-described heat radiation type preheater, another preheater having a structure in which hot air is blown against the printed circuit board running from the outlet of the heater is installed in parallel, and heat radiation and hot air An automatic soldering device capable of heating a printed circuit board from both sides has been developed and widely used.

Such a hot air type preheater is usually installed in a position closer to the printed circuit board side than the heat radiation type preheater in an automatic soldering device. Therefore, the above automatic soldering device has a configuration in which preheating with hot air is independently performed prior to preheating with radiation.

Further, recently, an integrated preheater in which both heat radiation type and hot air heating type preheaters are assembled and integrally assembled has been developed and used.

(Problems to be solved by the invention) However, all the conventional devices capable of preheating with both radiation and hot air have different configurations for radiant heating and hot air heating. Independently, the radiant heating was performed after the hot air heating. Even if it is an integral type pre-heater, it is merely one in which the heater by radiation and the heater by hot air are integrated, and belongs to the category of the above apparatus configuration.

Therefore, the conventional soldering system can give only a heating effect to the printed circuit board to the extent that radiation heating and hot air heating are combined, and it is necessary to further improve the insufficient heating effect. .

That is, a good soldering evaluation can be obtained for a printed circuit board on which an electronic component with a lead wire, which is sufficient for heating to some extent, is obtained, but an electronic chip component where more effective heating is required. For a printed circuit board on which is mounted, due to insufficient heating action, the flux coated surface of the printed circuit board is inadequately adhered to the molten solder, and soldering failure is likely to occur eventually, which is not always satisfactory. No good soldering evaluation was obtained.

Further, the conventional heat radiation type pre-heater has a problem that the heating distribution becomes very uneven because of the heat radiation from the meandering heater. Non-uniform heating will adversely affect the quality of the soldered printed circuit board. Such problems have not been solved even in the recent preheating device configuration capable of both radiant heating and hot air heating.

Furthermore, since the heater is exposed in the conventional heat radiation type preheater, it is unexpectedly likely that a part of the masking tape attached to the heater comes into contact with the heater when the printed circuit board is running and causes a fire. There was also a need for improvement in safety.

The present invention has been made in consideration of such circumstances, and its purpose is to improve the heating effect further, to enable heating with a uniform distribution, and to further improve the safety. It is to provide a preheater.

(Means for Solving the Problems) The preheating device for soldering according to the present invention comprises a box-shaped heater body, a heat radiation plate provided on the upper surface of the heater body, and a heat radiation plate disposed inside the heater body. And a blower fan attached to the heater body so as to communicate with the inside thereof, and the heat radiation plate embeds the radiation heater in a metal plate having good thermal conductivity. Alternatively, it is characterized in that it is sandwiched between a plurality of the metal plates, and that a large number of hot air blowing holes communicating with the inside of the main body are formed on substantially the entire surface.

(Summary of the Invention) The heater body is provided with a heat radiating plate on the upper surface and a hot air heater inside, and is preferably housed in a larger housing.

First, the heat radiation plate has a structure in which a radiation heater is sandwiched between a plurality of metal plates having good thermal conductivity, heat from the heater is transferred to the metal plate, and is quickly transferred to the entire metal plate. Therefore, heat can be radiated from the entire surface of the metal plate, in other words, from the entire upper surface of the heater body.

Another configuration of the heat radiation plate is that the radiation heater is embedded in a similar metal plate. Due to the rapid heat transfer, heat radiation from the entire surface is likewise possible.

Preferably, a plurality of radiant heaters are arranged substantially uniformly on the upper surface of the heat radiating plate, for example, rod-shaped heaters are arranged in parallel at regular intervals. Further, a suitable metal plate is generally an aluminum plate or a copper plate having high heat conductivity. With these, the heat radiating plate can be heated almost isothermally.

Further, the heat radiation plate has a large number of hot air blowing holes formed substantially over the entire surface while avoiding the radiation heater. The blowout hole is a through hole that communicates with the inside of the heater body, and hot air from the inside passes therethrough.

On the other hand, the hot air heater is usually composed of 1 to about 10 heaters, and is preferably uniformly arranged inside the heater body.

Further, the air supply fan is provided so as to communicate with the inside of the heater main body, and sends outside air to the hot air heater inside the main body during operation. After that, the air heated by the heater is blown as hot air to the traveling printed circuit board through the blowout holes.

In the preheater of the present invention, in addition to the above-mentioned structure, it is preferable to provide punching metal, fine wire mesh, etc. inside the heater main body so as to rectify the hot air passing therethrough to make the heating more uniform.

(Operation) According to such a configuration of the present invention, the heat radiation plate is heated by the energization of the sandwiching or embedded heater, and the heat radiation is emitted upward from the upper surface of the heater. At the same time, by the operation of the fan, the hot air heated by the heater in the heater body is blown upward from the holes on the upper surface of the heater. Therefore, it is possible to simultaneously heat the printed circuit board running above the preheater by heat radiation and heating by hot air.

Therefore, the heating action works synergistically by the combination of both.
Moreover, the hot air blown out passes through the blowout holes of the heat radiation plate heated to a high temperature, so that the hot air becomes hotter. Therefore, the heating effect on the printed circuit board becomes more and more effective.

Further, in the preheater according to the present invention, the entire heat radiating plate is heated to a substantially equal temperature, so that the radiation is substantially evenly emitted from the entire surface of the heat radiating plate. On the other hand, since the blowout holes are provided substantially uniformly on the heat radiation plate, the blowing of hot air is
It is performed almost uniformly on the main surface of the heat radiation plate. Therefore, since both the radiant heating and the hot air heating are performed substantially uniformly, the distribution of the heating from the upper surface of the preheater becomes substantially uniform.

Further, in the structure of the present invention, if the hot air heater in the heater is arranged so as not to be located directly below the blowout hole, the masking tape or the like stretched over the printed circuit board may come into direct contact with the heater when running. Disappear. Therefore, the risk of fire is reduced.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows the appearance of the preheater of this embodiment. This preheater is incorporated in an automatic soldering device (not shown) slightly below the running surface of the printed circuit board. FIG. 3 shows a state in which the left and right cover plates 11, 11 of the rectangular parallelepiped housing 10 of the heater are removed. As shown in this figure, the box-shaped heater body 1 is housed in a housing 10.

As shown clearly in FIG. 1, the heater main body 1 has rod-shaped hot air heaters 3 ... Arranged in the inside 2 thereof in parallel and at substantially the same height, and a heat radiation plate 5 is provided on the upper surface thereof. It will be provided.

Each of the hot air heaters 3 projects to the outside of the main body 1 and has a conductive plate 14
Are connected to each other by means of, and simultaneous energization is possible (Fig. 3).

The heat radiation plate 5 is, as shown in FIG. 1 and enlarged FIG. 5, two metal plates having good thermal conductivity, for example, aluminum plates 6 and 7, and round grooves 16 and 17 are formed on these surfaces. Both of them are formed in parallel at equal intervals, and a plurality of radiant heaters 8 housed in the circular grooves 16 and 17 and sandwiched between the metal plates 6 and 7.
・ ・ It consists of.

Each of the hot air heaters 8 projects to the outside of the heater body 1 and is connected together by a conductive plate 13 so that simultaneous energization is possible (Fig. 3). Therefore, almost uniform heat radiation from the entire surface of the plate 5 is possible.

As shown in FIGS. 1 and 4, the heat radiation plate 5 has a large number of hot air blowing holes 9 ... Formed substantially uniformly over the main surface of the plate 5 and avoiding the radiation heater 8. , The outside and the inside 2 of the heater body are communicated with each other. Reference numeral 15 shown in FIG. 4 is a hole for assembling the radiation plate 5 to the main body 1, and is a long hole in consideration of thermal expansion.

Further, the heater main body 1 has three fans 4 ...
The external air is sent to each heater 3 by the operation of the fan 4, and is blown upward from the holes 9 ... After heating. Therefore, almost uniform hot air heating is possible from the entire heat radiation plate 5. A punching metal 12 is stretched inside the main body 2 in order to rectify the air supplied to the heater 3.

Thus, the preheater of the example has a remarkably high heating effect due to simultaneous heating by radiation and hot air, and a sufficiently satisfactory soldering result was obtained even for a printed circuit board on which chip electronic components were mounted. Moreover, the heating action was almost uniform over the entire upper surface, and a high quality soldered product was obtained.

(Effects of the Invention) As described above, the preheating device for soldering according to the present invention can simultaneously heat the traveling printed circuit board by heat radiation and hot air.
The heating effect is dramatically increased by combining the two. Therefore, not only for the printed circuit board on which electronic components with lead wires are mounted, but also for the printed circuit board on which electronic chip components where relatively high heating effect is required is mounted, Adhesion between the molten solder and the molten solder becomes sufficient, and a satisfactory soldering evaluation as desired can be obtained.

In addition, the preheater of the present invention can perform both radiant heating and hot air heating substantially uniformly on the upper surface of the heater, and the heating distribution on the printed substrate is also substantially uniform, which is very high. It is possible to obtain a quality soldered product.

In addition, the heater of the present invention can avoid the direct contact between the heater and the combustible material stretched on the printed circuit board by devising the arrangement of the hot air heater, and can reduce the risk of fire, thus ensuring safety. In terms of, it will be more improved.

[Brief description of drawings]

1 is a sectional view showing the inside of the main body of a soldering preheater of an embodiment of the present invention (a sectional view taken along the line I--I of FIG. 4), and FIG. 2 is a soldering preheater of the embodiment. 3 is a perspective view showing the soldering preheater of FIG. 2 with the left and right cover plates removed, and FIG. 4 is a heat radiation plate of the preheater of FIG. 1. FIG. 5 is an enlarged cross-sectional view showing a part of the heat radiation plate of the preheater shown in FIG. In the figure, 1 ... heater main body 2 ... inside the main body 3 ... hot air heater 4 ... air supply fan 5 ... heat radiation plate 6, 7 ... metal plate 8 ... radiation heater 9 ... hot air blowing hole 10 ……housing

Claims (1)

[Scope of utility model registration request] 1. A box-shaped heater main body, a heat radiation plate provided on the upper surface of the heater main body, a hot air heater arranged inside the heater main body, and the heater main body communicating with the inside thereof. The heat radiation plate is formed by embedding the radiant heater in a metal plate having good thermal conductivity or by sandwiching it between a plurality of metal plates, and A preheating device for soldering, characterized in that a large number of hot air blowing holes communicating with the inside of the main body are formed on substantially the entire surface.