JP2003188525A - Reflow furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce bad products produced by scattering of a solvent for solder, and hence reduce works such as an inspection for the total produced printed boards and the correction for a scattered portion by manual work. <P>SOLUTION: When a cylinder 17 pulls in a rod upon a conveyance mechanism 6 is interrupted, a guide rod 20 lowers guided by a guide 19, whereby a cover mounting structure 21 is lowered, and a cover 16 provided, corresponding to a printed board 4, on a lower surface of the cover mounting structure 21 covers a land 4A on the printed board 4. Namely, the cover 16 having the size to cover a hatched area S1 including the land 4A on each printed board 4 covers a portion on the printed board 4 liable to be influenced, i.e., the land 4A upon the interruption of conveyance by the conveyance mechanism 6 even when the solder 10 is melted with a heater block 5 and a solvent is scattered. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflow furnace for melting solder to solder an electronic component on a printed circuit board.

[0002]

2. Description of the Related Art In the reflow furnace, generally, due to the characteristics of the solder paste, the solvent is more or less scattered when the solder is melted.

[0003]

Therefore, when the solvent of the solder is scattered, flux and solder balls may be scattered together, which may affect the circuit on the printed circuit board. Was becoming.

Therefore, conventionally, various conditions related to reflow such as solder composition and reflow profile have been changed and set, and optimum conditions have been searched for so as to minimize the amount of solvent scattering. Was not.

Therefore, an object of the present invention is to reduce product defects due to the scattering of the solder solvent, and to reduce the work such as 100% inspection of the produced printed circuit boards and the manual correction of the scattered parts. .

[0006]

Therefore, the first invention is
In a reflow furnace that melts solder and solders electronic components onto a printed circuit board, a transfer mechanism that intermittently transfers the printed circuit board and a portion that is affected on the printed circuit board by the dispersion of the solvent due to the melting of the solder. A cover is provided to cover the conveyance mechanism when the conveyance is stopped.

A second invention is a reflow furnace for melting a solder to solder an electronic component on a printed circuit board, and a transfer mechanism for intermittently transferring the printed circuit board,
In order to prevent the solvent from being scattered due to the melting of the solder, a cover is provided to cover a scattered portion on the printed circuit board when the transportation of the transportation mechanism is stopped.

Furthermore, a third invention is characterized in that the cover in the second invention is connected to a suction mechanism for sucking the scattered solvent.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below in detail with reference to the accompanying drawings. In FIG. 1, reference numeral 1 denotes a reflow furnace for melting a solder 10 and soldering an electronic component 11 on a printed circuit board 4, and a plurality of heaters for heating the printed circuit board 4 on an upper part of a machine base 2 via a mounting base 3. The block 5 is provided along the substrate transfer direction.

Reference numeral 6 denotes a transfer mechanism for transferring the printed circuit board 4 intermittently, and a drive roller 7 and a driven roller 8 driven by a drive source (not shown) are provided at the entrance and the exit of the reflow furnace 1 to perform the printing. The printed board 4 is intermittently conveyed by intermittently moving the belt 9 on which the board 4 is placed.

Therefore, the printed circuit board 4 is transferred to the transfer mechanism 6 described above.
Thus, the electronic component 11 is fixed on the printed circuit board 4 by being heated by the heater block 5 to melt the solder 10 and then being cured while being intermittently transported.

Reference numeral 15 denotes an up-and-down mechanism provided on the mounting plate 14 above the heater block 5, and the up-and-down mechanism 15 moves up and down the cover 16 having a U-shaped cross section. The up-and-down mechanism 15 is provided on a cylinder 17 as a drive source fixed on the mounting plate 14, an up-and-down plate 18 fixed to a rod of the cylinder 17, and a guide 19 provided on the up-and-down plate 18, respectively. The guide rod 20 and a cover mounting body 21 provided at the lower end of the guide rod 20.

When the cylinder 17 pulls in the rod when the transport mechanism 6 is stopped, the guide 1
As the guide rod 20 descends following the guide rod 9, the cover mounting body 21 descends, and the cover 16 provided on the lower surface of the cover mounting body 21 corresponding to the printed circuit board 4 has the land 4A on the printed circuit board 4. Will be covered.

That is, as shown in FIG. 2, a hatched area S including lands 4A and the like in each printed circuit board 4.
Even if the solder 10 is melted by the heater block 5 and the solvent is scattered by the cover 16 having a size that covers 1 (see FIG. 3), the affected portion on the printed circuit board 4, that is, the land 4A, It is covered when the transportation of the transportation mechanism 6 is stopped.

After that, the cylinder 17 operates to extend the rod, raise the cover 16, move the printed circuit board 4 by a predetermined pitch by the transfer mechanism 6, and so on.

Therefore, it is possible to reduce product defects (defective substrates) due to the scattering of the solvent of the solder 10 and to reduce the work such as the total inspection of the printed boards 4 produced and the correction of the scattered portions by manual work. it can.

Next, a second embodiment will be described with reference to FIGS. In this embodiment, the solder 1
In order to prevent the solvent from being scattered due to the melting of 0, the cover 30 that covers the scattered portion on the printed circuit board 4, that is, the solder 10 on which the electronic component 11 is mounted when the transportation of the transportation mechanism 6 is stopped, is performed. It is provided on the lower surface of the cover mounting body 21. Moreover, the cover 30 is connected to a suction mechanism that sucks the scattered solvent.

That is, as shown in FIG. 4, in each printed circuit board 4, the solder 1 on which the electronic component 11 is mounted is mounted.
0 and a cover 30 having a lower surface opening having a size that covers the hatched area S2 including the electronic component 11 (see FIG. 5).
), A portion where the solder 10 is melted by the heater block 5 and the solvent is scattered, that is, an electronic component 11 is provided on the portion.
A suction pipe that covers the portion where the solder 10 applied is placed when the transportation of the transport mechanism 6 is stopped and that is connected to a suction port 31 and a suction source (not shown) provided in the central portion of the upper surface of the cover 30. The solvent scattered to the outside of the furnace via 32 is discharged.

Therefore, it is possible to reduce product defects (defective substrates) due to the scattering of the solvent of the solder 10 and to reduce the work such as the total inspection of the printed boards 4 produced and the correction of the scattered portions by manual work. it can.

Although the embodiments of the present invention have been described above, various alternatives, modifications or variations can be made by those skilled in the art based on the above description, and the present invention can be carried out in the above-mentioned various forms without departing from the spirit of the invention. It is intended to cover alternatives, modifications or variations.

[0021]

As described above, according to the present invention, product defects due to the scattering of the solvent of the solder are reduced, and the work such as the total inspection of the printed circuit boards produced and the correction of the scattered parts by the manual work is reduced. Can be achieved.

[Brief description of drawings]

FIG. 1 is a front view of a reflow furnace that can be partially broken.

2 is a front view of a main part of the reflow furnace, which is a circle A in FIG.
FIG.

FIG. 3 is a plan view of a printed circuit board.

FIG. 4 is a front view of a main part of a reflow furnace according to a second embodiment.

FIG. 5 is a plan view of a printed circuit board.

[Explanation of symbols]

1 reflow furnace 4 printed circuit boards 4A Land 5 heater block 6 Transport mechanism 10 Solder 16, 30 cover 17 cylinders 21 Cover mount 31 Suction port 32 suction tube

Claims (3)

[Claims] 1. A reflow furnace for melting solder to solder an electronic component onto a printed circuit board, and a transport mechanism for intermittently transporting the printed circuit board and a solvent on the printed circuit board due to the solvent being scattered by the melting of the solder. A reflow furnace comprising: a cover for covering an affected part when the transfer of the transfer mechanism is stopped. 2. A reflow furnace for melting a solder to solder an electronic component onto a printed circuit board, and a transport mechanism for intermittently transporting the printed circuit board, and the solvent for preventing the solvent from scattering due to the melting of the solder. A reflow furnace, comprising: a cover for covering scattered portions on a printed circuit board when the transportation of the transportation mechanism is stopped. 3. The reflow furnace according to claim 2, wherein the cover is connected to a suction mechanism that sucks the scattered solvent.