JP2003304059A - Method of transporting substrate in soldering oven (reflow furnace) - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of transporting substrate that makes heating time freely settable in a soldering reflow furnace. <P>SOLUTION: In this method, a printed board mounted with parts can be transported in the soldering reflow furnace by supporting both ends of the board by two rails formed in L- or U-shapes, while pushing the rear side of the board with a projection attached to a rope or chain by changing the advancing speed of the board so that the board may be stopped. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for transporting a substrate in a soldering oven for electronic and electric parts. 2. Description of the Related Art In a soldering oven, a substrate is transported in a furnace heated to a high temperature by a chain conveyor or a net conveyor constituted by a chain with pins.
I've been soldering. In a conventional chain conveyor with pins and a net conveyor, if the conveyor speed is set to a certain value, the heating time of the substrate is determined by the length of the heater and the number of heating zones. For the soldering oven, the conveyor speed and the heater temperature of each heating zone can be set and changed arbitrarily, but the length of the overheating zone is fixed. The ratio is difficult to change. Further, when the substrate is warped by heating, it is necessary to transport the substrate while supporting it by a lower support mechanism having a drive source in order to prevent the warpage. In order to minimize the warpage of the substrate, a method of sandwiching the substrate end in the chain, or a mechanism of adding a roller to the outlet-side cooling section and forcibly correcting the warp by sandwiching the substrate end is required. In the present invention, an L-shaped substrate is used.
Alternatively, both ends of the substrate are supported by two metal rails processed into a U-shape, and the substrate is moved while pushing the rear of the substrate by a protrusion attached to a rope or a chain. This substrate moving mechanism can be manufactured at a variable speed, and is driven so that it can be stopped and moved freely at any position in the furnace. Therefore, the time between the heating zones can be adjusted regardless of the heater length. To prevent the substrate from being warped by heating, use a U-shaped rail and move it while sandwiching the edge of the substrate, and support from the bottom of the substrate only by placing a metal rod or plate at the place where you want to support the substrate . When abrasion marks when sliding on the lower support become a problem, it may be supported by a driving rope or a chain. By using the substrate transport mechanism according to this consideration, the degree of freedom of the substrate heating temperature time is greatly increased, and the mounting of the warpage prevention mechanism is facilitated. Embodiment 1 Embodiment 1 will be described with reference to FIG. The first embodiment is an example in which a board is transported on an L-shaped rail. The substrate transported by the pre-process belt conveyor is stopped at the end of the belt conveyor. After the sensor confirms that the substrate is present at the end of the belt conveyor, the substrate transport mechanism is started, and the substrate is moved, shifted, stopped, and moved in the furnace together with the substrate while pushing the rear of the substrate by the protrusion. After the transfer is completed,
Lower the protrusion on the chain and retreat to the starting point. A plurality of such transfer mechanisms may be incorporated in the oven in accordance with the tact time required for production. Embodiment 2 Embodiment 2 will be described with reference to FIG. The second embodiment is an example in which a board is conveyed by sandwiching the board between U-shaped rails. The drive system for transporting the substrate is the same as that of the first embodiment, but the warp of the substrate is prevented by the metal brazing supporting the substrate from below and the effect of the metal plate, and the warping of the substrate is forcibly performed by the cooling unit behind the oven. It becomes possible to correct it. Third Embodiment A third embodiment will be described with reference to FIG. The third embodiment is a mechanism that uses a U-shaped rail to support the lower part of the substrate with a rope and a chain for transporting the substrate, supports the substrate from below without scratching, transports the substrate, and prevents warpage. The effects of the present invention are to make it possible to flexibly cope with diversified soldering joints and to easily prevent the warpage of the substrate.

[Brief description of the drawings] FIG. 1 is a perspective view showing Example-1. FIG. 2 is a perspective view showing Example-2. FIG. 3 is a perspective view showing Example-3. [Explanation of symbols]   substrate   L-shaped rail   U-shaped rail   Substrate transfer system   Substrate transport projection   Board warp prevention lower support   Pre-process belt conveyor

Claims (1)

Claims 1. A transport mechanism for sliding and transporting a board to be soldered on an L-shaped rail or a U-shaped rail or a board with a jig.