JPS61162265A - Reflow furnace - Google Patents

Abstract

PURPOSE:To solder a printed wiring board to be soldered without melting the solder on the packaged side by directing the one side of the wiring board toward the inside of a furnace, conveying the wiring board in such a manner that the other side contacts with the external air and soldering only the side faced to the inside of the furnace. CONSTITUTION:A conveyor belt 5 which conveys the printed wiring board 10 to be soldered into a reflow furnace is constituted of a bendable heat insulating material and is provided with holes 11 sized approximately equal to the size of the wiring board 10. A mesh is adhered to each hole. The reflow furnace is constituted of heat sources 1, 2, 3. The wiring board 10 packed one side is installed in the hole 11 by directing the side to be soldered toward the inside of he furnace. The wiring board is then conveyed by the belt 5 into the furnace where the board is subjected to soldering. The wiring board is thus soldered without melting the solder on the already packaged side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a soldering apparatus for printed wiring boards that performs double-sided 5-surface mounting. [Prior Art] The structure of a conventional reflow oven will be explained with reference to FIGS. 3 and 4. Figure 3 ■■ and Figure 4 ■■ are insulation materials that make up the furnace, Figure 3 ■■■ and Figure 4 ■■■■■■ are heat sources such as electric panel heaters, and Figure 6 ■ and 4 are heat sources such as electric panel heaters. Figure ■ shows a conveyor belt for conveying printed wiring boards. Conventionally, in order to prevent heat from the heat source from radiating and dissipating, or to keep the temperature inside the furnace stable, insulation was used to separate the heat source from the outside air, except for structurally unavoidable parts such as the entrance and exit of the conveyor belt. and constituted a complete furnace.

[Problem that the invention seeks to solve]

However, according to this method, both sides S, u r f'
In ACE mounting, when one side is generally mounted and the other side is to be reflow soldered,
The solder on a certain surface may melt, reducing soldering quality, or parts on that surface may fall. Therefore, a process such as fixing the components on the surface that has been mounted first with adhesive is required. This is because the temperature inside the furnace 70 is almost constant, so both printed wiring boards passing through it have almost the same temperature. The present invention eliminates this cause and provides a method for creating a temperature difference between both sides of a printed wiring board during reflow.

[Failure to solve the problem]

The reflow soldering furnace of the present invention has a heat source such as an electric heater and a lamp, a power source for transporting the printed wiring board to be soldered [1], and a transport device. The printed wiring board is transported with one side facing inside the furnace and the other side left in contact with the outside air, thereby completing the half-wiring on only the side facing inside the furnace. Effect] According to the above configuration of the present invention, half E of the printed wiring board
It is possible to finish the soldering process by melting only the half L11 on which the soldering is to be performed, without melting the half IH on the opposite side, which is generally mounted. [Example] Fig. 1 2 is an overall view of an embodiment of the present invention, and FIG. 2 is a side view (a) and a top view (b) of a conveyor belt portion thereof.

As shown in Figure 2, fold the conveyor belt
A hole of approximately the same size as the printed wiring board to be soldered is provided in it, and a mesh is further placed in the hole so that the printed wiring board can be placed. (Fig. 2 (h) (S) -I-, When a reflow oven as shown in Fig. 1 is constructed using the conveyor belt shown in Fig. 1, the heat insulation efficiency shown in Fig. 1 and the conveyor belt shown in A complete furnace can be constructed, and the printed wiring boards to be soldered (Fig. 2 (a) [phase],
In FIG. 2(b) [phase]), the − side faces the inside of the furnace, and the other side can be allowed to pass through the inside of the apparatus while always being in contact with the outside air.

〔Effect of the invention〕

In this way, the present invention can be applied to one side of a printed wiring board.
Since it is possible to pass through the reflow oven with one side facing inside the furnace and the other side facing the outside air, it is possible to maintain an extremely large temperature difference between both sides of the board during soldering. Therefore, unlike conventional reflow ovens, double-sided printed wiring boards are generally round plates with one side mounted, and the mounted components can be fixed on the other side without being fixed by any method other than soldering. It is possible to perform soldering. Note that the present invention is not limited to those shown in FIGS. 1 and 2, and may be applied to any other reflow oven configuration as long as one side of the printed wiring board faces inside the furnace and the other side faces the outside air. It doesn't matter if there is.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of the configuration of the reflow oven of the present invention, where ■■■ is a heat source such as an electric panel, ■ is a heat insulating material that constitutes a part of the furnace, and ■ is a part of the furnace. At the same time, it is a conveyor belt for conveying the printed wiring board to be soldered. 2m<a)<h> are views showing an example of the structure of the conveyor belt in Fig. 1■, (α) is a side sectional view, (b)
is a top view. FIG. 6 and FIG. 4 are diagrams showing examples of the configuration of a conventional reflow oven. that's all

Claims (1)

[Claims] In a reflow soldering furnace that has a heat source such as an electric heater or a lamp, a power source for transporting the printed wiring board to be soldered, and a transport device, one side of the printed wiring board to be soldered is directed into the furnace, and the other side is A reflow furnace characterized in that a printed wiring board is transported with one side left in contact with the outside air, and soldering is completed only on the side facing into the furnace.